Sample records for differential downward stream
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Risch, Martin R.; Bunch, Aubrey R.; Vecchia, Aldo V.; Martin, Jeffrey D.; Baker, Nancy T.
2014-01-01
Statistically significant trends were identified that included 167 downward trends and 83 upward trends. The Kankakee River Basin had the most significant upward trends while the most significant downward trends were in the Whitewater River Basin, the Lake Michigan Basin, and the Patoka River Basin. For most constituents, a majority of sites had significant downward trends. Two streams in the Lake Michigan Basin have shown substantial decreases in most constituents. The West Fork White River near Indianapolis, Indiana, showed increases in nitrate and phosphorus and the Kankakee River Basin showed increases in copper, zinc, chloride, sulfate, and hardness. Upward trends in nutrients were identified at a few sites, but most nutrient trends were downward. Upward trends in metals corresponded with relatively small concentration increases while downward trends involved considerably larger concentration changes. Downward trends in chloride, sulfate, and suspended solids were observed statewide, but upward trends in hardness were observed in the northern half of Indiana.
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Ackers, D; Hejnowicz, Z; Sievers, A
1994-01-01
Velocities of cytoplasmic streaming were measured in internodal cells of Nitella flexilis L. and Chara corallina Klein ex Willd. by laser-Doppler-velocimetry to investigate the possibility of non-statolith-based perception of gravity. This was recently proposed, based on a report of gravity-dependent polarity of cytoplasmic streaming. Our measurements revealed large spatial and temporal variation in streaming velocity within a cell, independent of the position of the cell with respect to the direction of gravity. In 58% of the horizontally positioned cells the velocities of acropetal and basipetal streaming, measured at opposite locations in the cell, differed significantly. In 45% of these, basipetal streaming was faster than acropetal streaming. In 60% of the vertically positioned cells however the difference was significant, downward streaming was faster in only 61% of these. When cell positions were changed from vertical to horizontal and vice versa the cells reacted variably. A significant difference between velocities in one direction, before and after the change, was observed in approx. 70% of the measurements, but the velocity was faster in the downward direction, as the second position, in only 70% of the significantly different. The ratio of basipetal to acropetal streaming velocities at opposite locations of a cell was quite variable within groups of cells with a particular orientation (horizontal, normal vertical, inverted vertical). On average, however, the ratio was close to 1.00 in the horizontal position and approx. 1.03 in the normal vertical position (basipetal streaming directed downwards), which indicates a small direct effect of gravity on streaming velocity. Individual cells, however, showed an increased, as well as a decreased, ratio when moved from the horizontal to the vertical position. No discernible effect of media (either Ca(2+)-buffered medium or 1.2% agar in distilled water) on the streaming velocities was observed. The above mentioned phenomenon of graviperception is not supported by our data.
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NASA Technical Reports Server (NTRS)
Munk, Max; Cario, Gunther
1923-01-01
The data for the calculation of the air forces acting on the elevators, obtained from previous model experiments are not immediately applicable in practice, as the angle at which the control surfaces meet the air stream is, in general, still unknown. The air stream, when it reaches the elevator has already been deflected by the wings and although the velocity imparted to the air current by the wings is of negligible amount compared with the speed of flight, the air behind the wings has been deflected downwards, so that the elevators work in an airstream which is inclined in a downward direction. The angle at which the air stream meets the elevator surface is, therefore, different from, and, with the usual arrangement of elevators, less than the angle made by the elevator surfaces with the line of flight.
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Human sensitivity to vertical self-motion.
Nesti, Alessandro; Barnett-Cowan, Michael; Macneilage, Paul R; Bülthoff, Heinrich H
2014-01-01
Perceiving vertical self-motion is crucial for maintaining balance as well as for controlling an aircraft. Whereas heave absolute thresholds have been exhaustively studied, little work has been done in investigating how vertical sensitivity depends on motion intensity (i.e., differential thresholds). Here we measure human sensitivity for 1-Hz sinusoidal accelerations for 10 participants in darkness. Absolute and differential thresholds are measured for upward and downward translations independently at 5 different peak amplitudes ranging from 0 to 2 m/s(2). Overall vertical differential thresholds are higher than horizontal differential thresholds found in the literature. Psychometric functions are fit in linear and logarithmic space, with goodness of fit being similar in both cases. Differential thresholds are higher for upward as compared to downward motion and increase with stimulus intensity following a trend best described by two power laws. The power laws' exponents of 0.60 and 0.42 for upward and downward motion, respectively, deviate from Weber's Law in that thresholds increase less than expected at high stimulus intensity. We speculate that increased sensitivity at high accelerations and greater sensitivity to downward than upward self-motion may reflect adaptations to avoid falling.
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Lapham, Wayne W.
1989-01-01
The use of temperature profiles beneath streams to determine rates of vertical ground-water flow and effective vertical hydraulic conductivity of sediments was evaluated at three field sites by use of a model that numerically solves the partial differential equation governing simultaneous vertical flow of fluid and heat in the Earth. The field sites are located in Hardwick and New Braintree, Mass., and in Dover, N.J. In New England, stream temperature varies from about 0 to 25 ?C (degrees Celsius) during the year. This stream-temperature fluctuation causes ground-water temperatures beneath streams to fluctuate by more than 0.1 ?C during a year to a depth of about 35 ft (feet) in fine-grained sediments and to a depth of about 50 ft in coarse-grained sediments, if ground-water velocity is 0 ft/d (foot per day). Upward flow decreases the depth affected by stream-temperature fluctuation, and downward flow increases the depth. At the site in Hardwick, Mass., ground-water flow was upward at a rate of less than 0.01 ft/d. The maximum effective vertical hydraulic conductivity of the sediments underlying this site is 0.1 ft/d. Ground-water velocities determined at three locations at the site in New Braintree, Mass., where ground water discharges naturally from the underlying aquifer to the Ware River, ranged from 0.10 to 0.20 ft/d upward. The effective vertical hydraulic conductivity of the sediments underlying this site ranged from 2.4 to 17.1 ft/d. Ground-water velocities determined at three locations at the Dover, N.J., site, where infiltration from the Rockaway River into the underlying sediments occurs because of pumping, were 1.5 ft/d downward. The effective vertical hydraulic conductivity of the sediments underlying this site ranged from 2.2 to 2.5 ft/d. Independent estimates of velocity at two of the three sites are in general agreement with the velocities determined using temperature profiles. The estimates of velocities and conductivities derived from the temperature measurements generally fall within the ranges of expected rates of flow in, and conductivities of, the sediments encountered at the test sites. Application of the method at the three test sites demonstrates the feasibility of using the method to determine the rate of ground-water flow between a stream and underlying sediments and the effective vertical hydraulic conductivity of the sediments.
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Trends in Streamflow Characteristics at Long-Term Gaging Stations, Hawaii
Oki, Delwyn S.
2004-01-01
The surface-water resources of Hawaii have significant cultural, aesthetic, ecologic, and economic importance. Proper management of the surface-water resources of the State requires an understanding of the long- and short-term variability in streamflow characteristics that may occur. The U.S. Geological Survey maintains a network of stream-gaging stations in Hawaii, including a number of stations with long-term streamflow records that can be used to evaluate long-term trends and short-term variability in flow characteristics. The overall objective of this study is to obtain a better understanding of long-term trends and variations in streamflow on the islands of Hawaii, Maui, Molokai, Oahu, and Kauai, where long-term stream-gaging stations exist. This study includes (1) an analysis of long-term trends in flows (both total flow and estimated base flow) at 16 stream-gaging stations, (2) a description of patterns in trends within the State, and (3) discussion of possible regional factors (including rainfall) that are related to the observed trends and variations. Results of this study indicate the following: 1. From 1913 to 2002 base flows generally decreased in streams for which data are available, and this trend is consistent with the long-term downward trend in annual rainfall over much of the State during that period. 2. Monthly mean base flows generally were above the long-term average from 1913 to the early 1940s and below average after the early 1940s to 2002, and this pattern is consistent with the detected downward trends in base flows from 1913 to 2002. 3. Long-term downward trends in base flows of streams may indicate a reduction in ground-water discharge to streams caused by a long-term decrease in ground-water storage and recharge. 4. From 1973 to 2002, trends in streamflow were spatially variable (up in some streams and down in others) and, with a few exceptions, generally were not statistically significant. 5. Short-term variability in streamflow is related to the seasons and to the EL Ni?o-Southern Oscillation phenomenon that may be partly modulated by the phase of the Pacific Decadal Oscillation. 6. At almost all of the long-term stream-gaging stations considered in this study, average total flow (and to a lesser extent average base flow) during the winter months of January to March tended to be low following El Ni?o periods and high following La Ni?a periods, and this tendency was accentuated during positive phases of the Pacific Decadal Oscillation. 7. The El Ni?o-Southern Oscillation phenomenon occurs at a relatively short time scale (a few to several years) and appears to be more strongly related to processes controlling rainfall and direct runoff than ground-water storage and base flow. Long-term downward trends in base flows of streams may indicate a reduction in ground-water storage and recharge. Because ground water provides about 99 percent of Hawaii's domestic drinking water, a reduction in ground-water storage and recharge has serious implications for drinking-water availability. In addition, reduction in stream base flows may reduce habitat availability for native stream fauna and water availability for irrigation purposes. Further study is needed to determine (1) whether the downward trends in base flows from 1913 to 2002 will continue or whether the observed pattern is part of a long-term cycle in which base flows may eventually return to levels measured during 1913 to the early 1940s, (2) the physical causes for the detected trends and variations in streamflow, and (3) whether regional climate indicators successfully can be used to predict streamflow trends and variations throughout the State. These needs for future study underscore the importance of maintaining a network of long-term-trend stream-gaging stations in Hawaii.
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Powder collection apparatus/method
Anderson, I.E.; Terpstra, R.L.; Moore, J.A.
1994-01-11
Device for separating and collecting ultrafine atomized powder from the gas stream of a gas atomizing apparatus comprises a housing having an interior wall oriented at an angle relative to horizontal so as to form a downwardly converging, conical expansion chamber, an inlet conduit communicated to the expansion chamber proximate an upper region thereof for receiving the gas stream, and an outlet proximate a lower region of the expansion chamber. The inlet conduit is oriented at a compound inclined angle (with respect to horizontal) selected to promote separation and collection of powder from the gas stream in the expansion chamber. The compound angle comprises a first entrance angle that is greater than the angle of repose of the powder on the housing interior wall such that any powder accumulation in the inlet conduit tends to flow down the wall toward the outlet. The second angle is selected generally equal to the angle of the housing interior wall measured from the same horizontal plane so as to direct the gas stream into the expansion chamber generally tangent to the housing interior wall to establish a downward swirling gas stream flow in the expansion chamber. A powder collection container is communicated to the outlet of the expansion chamber to collect the powder for further processing. 4 figures.
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Powder collection apparatus/method
Anderson, Iver E.; Terpstra, Robert L.; Moore, Jeffery A.
1994-01-11
Device for separating and collecting ultrafine atomized powder from the gas stream of a gas atomizing apparatus comprises a housing having an interior wall oriented at an angle relative to horizontal so as to form a downwardly converging, conical expansion chamber, an inlet conduit communicated to the expansion chamber proximate an upper region thereof for receiving the gas stream, and an outlet proximate a lower region of the expansion chamber. The inlet conduit is oriented at a compound inclined angle (with respect to horizontal) selected to promote separation and collection of powder from the gas stream in the expansion chamber. The compound angle comprises a first entrance angle that is greater than the angle of repose of the powder on the housing interior wall such that any powder accumulation in the inlet conduit tends to flow down the wall toward the outlet. The second angle is selected generally equal to the angle of the housing interior wall measured from the same horizontal plane so as to direct the gas stream into the expansion chamber generally tangent to the housing interior wall to establish a downward swirling gas stream flow in the expansion chamber. A powder collection container is communicated to the outlet of the expansion chamber to collect the powder for further processing.
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Clow, David W.; Mast, M. Alisa
1999-01-01
Stream water data from five headwater basins in the northeastern United States covering water years 1968–1996 and precipitation data from eight nearby precipitation monitoring sites covering water years 1984‐1996 were analyzed for temporal trends in chemistry using the nonparametric seasonal Kendall test. Concentrations of SO4declined at three of five streams during 1968–1996 (p < 0.1), and all of the streams exhibited downward trends in SO4 over the second half of the period (1984–1996). Concentrations of SO4 in precipitation declined at seven of eight sites from 1984 to 1996, and the magnitudes of the declines (−0.7 to −2.0 µeq L−1 yr−1) generally were similar to those of stream water SO4. These results indicate that changes in precipitation SO4 were of sufficient magnitude to account for changes in stream water SO4. Concentrations of Ca + Mg declined at three of five streams and five of eight precipitation sites from 1984 to 1996. Precipitation acidity decreased at five of eight sites during the same period, but alkalinity increased in only one stream. In most cases the decreases in stream water SO4 were similar in magnitude to declines in stream water Ca + Mg, which is consistent with the theory of leaching by mobile acid anions in soils. In precipitation the magnitudes of SO4 declines were similar to those of hydrogen, and declines in Ca +Mg were much smaller. This indicates that recent decreases in SO4 deposition are now being reflected in reduced precipitation acidity. The lack of widespread increases in stream water alkalinity, despite the prevalence of downward trends in stream water SO4, suggests that at most sites, increases in stream water pH and acid‐neutralizing capacity may be delayed until higher soil base‐saturation levels are achieved.
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Nozzle for superconducting fiber production
Righi, Jamal
1992-11-17
A nozzle apparatus for producing flexible fibers of superconducting material receives melted material from a crucible for containing a charge of the superconducting material. The material is melted in the crucible and falls in a stream through a bottom hole in the crucible. The stream falls through a protecting collar which maintains the stream at high temperatures. The stream is then supplied through the downwardly directed nozzle where it is subjected to a high velocity air flow which breaks the melted superconducting material into ligaments which solidify into the flexible fibers. The fibers are collected by blowing them against a porous cloth.
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Kanwal, Jagmeet S; Medvedev, Andrei V; Micheyl, Christophe
2003-08-01
During navigation and the search phase of foraging, mustached bats emit approximately 25 ms long echolocation pulses (at 10-40 Hz) that contain multiple harmonics of a constant frequency (CF) component followed by a short (3 ms) downward frequency modulation. In the context of auditory stream segregation, therefore, bats may either perceive a coherent pulse-echo sequence (PEPE...), or segregated pulse and echo streams (P-P-P... and E-E-E...). To identify the neural mechanisms for stream segregation in bats, we developed a simple yet realistic neural network model with seven layers and 420 nodes. Our model required recurrent and lateral inhibition to enable output nodes in the network to 'latch-on' to a single tone (corresponding to a CF component in either the pulse or echo), i.e., exhibit differential suppression by the alternating two tones presented at a high rate (> 10 Hz). To test the applicability of our model to echolocation, we obtained neurophysiological data from the primary auditory cortex of awake mustached bats. Event-related potentials reliably reproduced the latching behaviour observed at output nodes in the network. Pulse as well as nontarget (clutter) echo CFs facilitated this latching. Individual single unit responses were erratic, but when summed over several recording sites, they also exhibited reliable latching behaviour even at 40 Hz. On the basis of these findings, we propose that a neural correlate of auditory stream segregation is present within localized synaptic activity in the mustached bat's auditory cortex and this mechanism may enhance the perception of echolocation sounds in the natural environment.
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Method of forming frozen spheres in a force-free drop tower
NASA Technical Reports Server (NTRS)
Kendall, J. M., Jr. (Inventor)
1982-01-01
Hollow glass spheres are shaped by the effects of surface tension acting on bubbles of glass in its molten state. A downwardly flowing stream of air accelerated at a one-G rate of acceleration is established through a drop bubbles on molten glass are introduced into the stream of air and frozen and as they are accelerated at a one-G rate of acceleration.
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Briggs, Martin A.; Buckley, Sean F.; Bagtzoglou, Amvrossios C.; Werkema, Dale D.; Lane, John W.
2016-01-01
Zones of strong groundwater upwelling to streams enhance thermal stability and moderate thermal extremes, which is particularly important to aquatic ecosystems in a warming climate. Passive thermal tracer methods used to quantify vertical upwelling rates rely on downward conduction of surface temperature signals. However, moderate to high groundwater flux rates (>−1.5 m d−1) restrict downward propagation of diurnal temperature signals, and therefore the applicability of several passive thermal methods. Active streambed heating from within high-resolution fiber-optic temperature sensors (A-HRTS) has the potential to define multidimensional fluid-flux patterns below the extinction depth of surface thermal signals, allowing better quantification and separation of local and regional groundwater discharge. To demonstrate this concept, nine A-HRTS were emplaced vertically into the streambed in a grid with ∼0.40 m lateral spacing at a stream with strong upward vertical flux in Mashpee, Massachusetts, USA. Long-term (8–9 h) heating events were performed to confirm the dominance of vertical flow to the 0.6 m depth, well below the extinction of ambient diurnal signals. To quantify vertical flux, short-term heating events (28 min) were performed at each A-HRTS, and heat-pulse decay over vertical profiles was numerically modeled in radial two dimension (2-D) using SUTRA. Modeled flux values are similar to those obtained with seepage meters, Darcy methods, and analytical modeling of shallow diurnal signals. We also observed repeatable differential heating patterns along the length of vertically oriented sensors that may indicate sediment layering and hyporheic exchange superimposed on regional groundwater discharge.
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Method and apparatus for high-efficiency direct contact condensation
Bharathan, D.; Parent, Y.; Hassani, A.V.
1999-07-20
A direct contact condenser having a downward vapor flow chamber and an upward vapor flow chamber, wherein each of the vapor flow chambers includes a plurality of cooling liquid supplying pipes and a vapor-liquid contact medium disposed thereunder to facilitate contact and direct heat exchange between the vapor and cooling liquid. The contact medium includes a plurality of sheets arranged to form vertical interleaved channels or passageways for the vapor and cooling liquid streams. The upward vapor flow chamber also includes a second set of cooling liquid supplying pipes disposed beneath the vapor-liquid contact medium which operate intermittently in response to a pressure differential within the upward vapor flow chamber. The condenser further includes separate wells for collecting condensate and cooling liquid from each of the vapor flow chambers. In alternate embodiments, the condenser includes a cross-current flow chamber and an upward flow chamber, a plurality of upward flow chambers, or a single upward flow chamber. The method of use of the direct contact condenser of this invention includes passing a vapor stream sequentially through the downward and upward vapor flow chambers, where the vapor is condensed as a result of heat exchange with the cooling liquid in the contact medium. The concentration of noncondensable gases in the resulting condensate-liquid mixtures can be minimized by controlling the partial pressure of the vapor, which depends in part upon the geometry of the vapor-liquid contact medium. In another aspect of this invention, the physical and chemical performance of a direct contact condenser can be predicted based on the vapor and coolant compositions, the condensation conditions, and the geometric properties of the contact medium. 39 figs.
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Method and apparatus for high-efficiency direct contact condensation
Bharathan, Desikan; Parent, Yves; Hassani, A. Vahab
1999-01-01
A direct contact condenser having a downward vapor flow chamber and an upward vapor flow chamber, wherein each of the vapor flow chambers includes a plurality of cooling liquid supplying pipes and a vapor-liquid contact medium disposed thereunder to facilitate contact and direct heat exchange between the vapor and cooling liquid. The contact medium includes a plurality of sheets arranged to form vertical interleaved channels or passageways for the vapor and cooling liquid streams. The upward vapor flow chamber also includes a second set of cooling liquid supplying pipes disposed beneath the vapor-liquid contact medium which operate intermittently in response to a pressure differential within the upward vapor flow chamber. The condenser further includes separate wells for collecting condensate and cooling liquid from each of the vapor flow chambers. In alternate embodiments, the condenser includes a cross-current flow chamber and an upward flow chamber, a plurality of upward flow chambers, or a single upward flow chamber. The method of use of the direct contact condenser of this invention includes passing a vapor stream sequentially through the downward and upward vapor flow chambers, where the vapor is condensed as a result of heat exchange with the cooling liquid in the contact medium. The concentration of noncondensable gases in the resulting condensate-liquid mixtures can be minimized by controlling the partial pressure of the vapor, which depends in part upon the geometry of the vapor-liquid contact medium. In another aspect of this invention, the physical and chemical performance of a direct contact condenser can be predicted based on the vapor and coolant compositions, the condensation conditions. and the geometric properties of the contact medium.
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NASA Astrophysics Data System (ADS)
Yuan, Zhigang; Qiao, Zheng; Li, Haimeng; Huang, Shiyong; Wang, Dedong; Yu, Xiongdong; Yu, Tao
2017-04-01
Subauroral polarization stream (SAPS) electric field can play an important role in the coupling between the inner magnetosphere and ionosphere; however, the production mechanism of SAPS has not been yet solved. During an energetic ion injection event on 26 March 2004, at latitudes lower than the equatorward boundaries of precipitating plasma sheet electrons and ions, the Defense Meteorological Satellite Program (DMSP) F13 satellite simultaneously observed a strong SAPS with the peak velocity of 1294 m/s and downward flowing field-aligned currents (FACs). Conjugate observations of DMSP F13 and NOAA 15 satellites have shown that FACs flowing into the ionosphere just lie in the outer boundary of the ring current (RC). The downward flowing FACs were observed in a region of positive latitudinal gradients of the ion energy density, implying that the downward flowing FACs are more likely linked to the azimuthal gradient than the radial gradient of the RC ion pressure. Our result demonstrates that RC ion pressure gradients on the outer boundary of the RC in the evening sector during energetic ion injection events can lead to downward flowing FACs so as to cause strong SAPS in condition of low ionospheric conductivities.
Plain Language SummaryThis paper provides a good case that the SAPS and FAC occurred in the outer boundary of the ring current during an energetic ion injection event. Our result demonstrates that RC ion pressure gradients on the outer boundary of the RC in the evening sector during energetic ion injection events can lead to downward flowing FACs so as to cause strong SAPS in condition of low ionospheric conductivities.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/672620','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/672620"><span>Superconductor fiber elongation with a heated injected gas</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Zeigler, D.D.; Conrad, B.L.; Gleixner, R.A.</p> <p>1998-06-02</p> <p>An improved method and apparatus for producing flexible fibers of superconducting material includes a crucible for containing a charge of the superconducting material. The material is melted in the crucible and falls in a stream through a bottom hole in the crucible. The stream falls through a protecting collar which maintains the stream at high temperatures. The stream is then supplied through a downwardly directed nozzle where it is subjected to a high velocity of a heated gas which breaks the melted superconducting material into ligaments which solidify into the flexible fibers. The fibers are collected by directing them against a collection filter. 10 figs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040089512&hterms=tea&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dtea','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040089512&hterms=tea&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dtea"><span>Gravity-dependent polarity of cytoplasmic streaming in Nitellopsis</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wayne, R.; Staves, M. P.; Leopold, A. C.</p> <p>1990-01-01</p> <p>The internodal cells of the characean alga Nitellopsis obtusa were chosen to investigate the effect of gravity on cytoplasmic streaming. Horizontal cells exhibit streaming with equal velocities in both directions, whereas in vertically oriented cells, the downward-streaming cytoplasm flows ca. 10% faster than the upward-streaming cytoplasm. These results are independent of the orientation of the morphological top and bottom of the cell. We define the ratio of the velocity of the downward- to the upward-streaming cytoplasm as the polar ratio (PR). The normal polarity of a cell can be reversed (PR < 1) by treatment with neutral red (NR). The NR effect may be the result of membrane hyperpolarization, caused by the opening of K+ channels. The K+ channel blocker TEA Cl- inhibits the NR effect. External Ca2+ is required for normal graviresponsiveness. The [Ca2+] of the medium determines the polarity of cytoplasmic streaming. Less than 1 micromole Ca2+ resulted in a PR < 1 while greater than 1 micromole Ca2+ resulted in the normal gravity response. The voltage-dependent Ca(2+)-channel blocker, nifedipine, inhibited the gravity response in a reversible manner, while treatment with LaCl3 resulted in a PR < 1, indicating the presence of two types of Ca2+ channels. A new model for graviperception is presented in which the whole cell acts as the gravity sensor, and the plasma membrane acts as the gravireceptor. This is supported by ligation and UV irradiation experiments which indicate that the membranes at both ends of the cell are required for graviperception. The density of the external medium also affects the PR of Nitellopsis. Calculations are presented that indicate that the weight of the protoplasm may provide enough potential energy to open ion channels.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11540068','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11540068"><span>Gravity-dependent polarity of cytoplasmic streaming in Nitellopsis.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wayne, R; Staves, M P; Leopold, A C</p> <p>1990-01-01</p> <p>The internodal cells of the characean alga Nitellopsis obtusa were chosen to investigate the effect of gravity on cytoplasmic streaming. Horizontal cells exhibit streaming with equal velocities in both directions, whereas in vertically oriented cells, the downward-streaming cytoplasm flows ca. 10% faster than the upward-streaming cytoplasm. These results are independent of the orientation of the morphological top and bottom of the cell. We define the ratio of the velocity of the downward- to the upward-streaming cytoplasm as the polar ratio (PR). The normal polarity of a cell can be reversed (PR < 1) by treatment with neutral red (NR). The NR effect may be the result of membrane hyperpolarization, caused by the opening of K+ channels. The K+ channel blocker TEA Cl- inhibits the NR effect. External Ca2+ is required for normal graviresponsiveness. The [Ca2+] of the medium determines the polarity of cytoplasmic streaming. Less than 1 micromole Ca2+ resulted in a PR < 1 while greater than 1 micromole Ca2+ resulted in the normal gravity response. The voltage-dependent Ca(2+)-channel blocker, nifedipine, inhibited the gravity response in a reversible manner, while treatment with LaCl3 resulted in a PR < 1, indicating the presence of two types of Ca2+ channels. A new model for graviperception is presented in which the whole cell acts as the gravity sensor, and the plasma membrane acts as the gravireceptor. This is supported by ligation and UV irradiation experiments which indicate that the membranes at both ends of the cell are required for graviperception. The density of the external medium also affects the PR of Nitellopsis. Calculations are presented that indicate that the weight of the protoplasm may provide enough potential energy to open ion channels.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/873493','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/873493"><span>Superconductor fiber elongation with a heated injected gas</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Zeigler, Douglas D.; Conrad, Barry L.; Gleixner, Richard A.</p> <p>2001-01-16</p> <p>An improved method and apparatus for producing flexible fibers (30) of superconducting material includes a crucible (12) for containing a charge of the superconducting material. The material is melted in the crucible (12) and falls in a stream (18) through a bottom hole (16) in the crucible (12). The stream (18) falls through a protecting collar (22) which maintains the stream (18) at high temperatures. The stream (18) is then supplied through a downwardly directed nozzle (26) where it is subjected to a high velocity of a heated gas (36') which breaks the melted superconducting material into ligaments which solidify into the flexible fibers (30). The fibers (30) are collected by directing them against a collection filter (32).</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li class="active"><span>1</span></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_1 --> <div id="page_2" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li class="active"><span>2</span></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="21"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/871591','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/871591"><span>Superconductor fiber elongation with a heated injected gas</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Zeigler, Douglas D.; Conrad, Barry L.; Gleixner, Richard A.</p> <p>1998-06-02</p> <p>An improved method and apparatus for producing flexible fibers (30) of superconducting material includes a crucible (12) for containing a charge of the superconducting material. The material is melted in the crucible (12) and falls in a stream (18) through a bottom hole (16) in the crucible (12). The stream (18) falls through a protecting collar (22) which maintains the stream (18) at high temperatures. The stream (18) is then supplied through a downwardly directed nozzle (26) where it is subjected to a high velocity of a heated gas (36') which breaks the melted superconducting material into ligaments which solidify into the flexible fibers (30). The fibers (30) are collected by directing them against a collection filter (32).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AIPC.1569..398R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AIPC.1569..398R"><span>Film condensation of steam flowing downward on a tier of horizontal cylinders at different inclination angles in the presence of a non-condensable gas</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ramadan, Abdulghani; Yamali, Cemil</p> <p>2013-12-01</p> <p>The problem of forced laminar film condensation of steam flowing downward a tier of horizontal cylinders is investigated numerically. The effects of free stream non-condensable gas, air concentration (m1,∞), free stream velocity (Reynolds number), cylinder diameter, and angle of inclination on the condensation heat transfer are analyzed. Two flow arrangements, inline and staggered, are analyzed and investigated. The mathematical model takes into account the effect of staggering of the cylinders and how condensation is affected at the lower cylinders when condensate does not fall on to the center line of the cylinders. Condensation heat transfer results are available in ranges from (U∞ = 1 - 30 m/s) for free stream velocity, (m1,∞ = 0.01 -0.8) for free stream air mass fraction and (D = 12.7 -50.8 mm) for cylinder diameter. Results show that; a remarked reduction in the vapor side heat transfer coefficient is noticed. This results from the presence of small amounts of free stream air mass fractions in the steam-air mixture and increase in the cylinder diameter. On the other hand, it increases by increasing the free stream velocity (Reynolds number). Average heat transfer coefficient at the middle and the bottom cylinders increases by increasing the angle of inclination, whereas, no significant change is observed for that of the upper cylinder. Down the bank, a rapid decrease in the vapor side heat transfer coefficient is noticed. It may be resulted from the combined effects of inundation, decrease in the vapor velocity and increase in the non-condensable gas (air) at the bottom cylinders in the bank.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120012692','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120012692"><span>Computational Analyses of Offset Stream Nozzles for Noise Reduction</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dippold, Vance, III; Foster, Lancert; Wiese,Michael</p> <p>2007-01-01</p> <p>The Wind computational fluid dynamics code was used to perform a series of simulations on two offset stream nozzle concepts for jet noise reduction. The first concept used an S-duct to direct the secondary stream to the lower side of the nozzle. The second concept used vanes to turn the secondary flow downward. The analyses were completed in preparation of tests conducted in the NASA Glenn Research Center Aeroacoustic Propulsion Laboratory. The offset stream nozzles demonstrated good performance and reduced the amount of turbulence on the lower side of the jet plume. The computer analyses proved instrumental in guiding the development of the final test configurations and giving insight into the flow mechanics of offset stream nozzles. The computational predictions were compared with flowfield results from the jet rig testing and showed excellent agreement.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890036854&hterms=hydrodynamic+electron+flow&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dhydrodynamic%2Belectron%2Bflow','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890036854&hterms=hydrodynamic+electron+flow&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dhydrodynamic%2Belectron%2Bflow"><span>Multistream hydrodynamic modeling of interhemispheric plasma flow</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rasmussen, C. E.; Schunk, R. W.</p> <p>1988-01-01</p> <p>Interhemispheric plasma flow was simulated using one-stream and two-stream hydrodymic models in order to test the suggestion of Banks et al. (1971) and others that the collision of high-speed flows originating from the conjugate hemispheres will cause the formation of a pair of shocks. The single-fluid hydrodynamic equations were modified to include multiple ion streams, allowing for the possibility of counterstreaming flow. It was found that a counterstreaming of ion streams from conjugate hemispheres does occur during the early stages of the refilling of plamaspheric flux tubes, and that a pair of reverse shocks does form. These shocks form away from the equator, and their subsequent motion creates conditions similar to those predicted by the single-stream hydrodynamic models. The findings support the conclusion of earlier studies that the refilling of the plasmasphere occurs from the equatorial region downward.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/6366899','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/6366899"><span>Vertical flow chemical detection portal</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Linker, K.L.; Hannum, D.W.; Conrad, F.J.</p> <p>1999-06-22</p> <p>A portal apparatus is described for screening objects or persons for the presence of trace amounts of chemical substances such as illicit drugs or explosives. The apparatus has a test space, in which a person may stand, defined by two generally upright sides spanned by a horizontal transom. One or more fans in the transom generate a downward air flow (uni-directional) within the test space. The air flows downwardly from a high pressure upper zone, past the object or person to be screened. Air moving past the object dislodges from the surface thereof both volatile and nonvolatile particles of the target substance. The particles are entrained into the air flow which continues flowing downward to a lower zone of reduced pressure, where the particle-bearing air stream is directed out of the test space and toward preconcentrator and detection components. The sides of the portal are specially configured to partially contain and maintain the air flow. 3 figs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/872350','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/872350"><span>Vertical flow chemical detection portal</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Linker, Kevin L.; Hannum, David W.; Conrad, Frank James</p> <p>1999-01-01</p> <p>A portal apparatus for screening objects or persons for the presence of trace amounts of chemical substances such as illicit drugs or explosives. The apparatus has a test space, in which a person may stand, defined by two generally upright sides spanned by a horizontal transom. One or more fans in the transom generate a downward air flow (uni-directional) within the test space. The air flows downwardly from a high pressure upper zone, past the object or person to be screened. Air moving past the object dislodges from the surface thereof both volatile and nonvolatile particles of the target substance. The particles are entrained into the air flow which continues flowing downward to a lower zone of reduced pressure, where the particle-bearing air stream is directed out of the test space and toward preconcentrator and detection components. The sides of the portal are specially configured to partially contain and maintain the air flow.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70032127','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70032127"><span>Using heat to characterize streambed water flux variability in four stream reaches</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Essaid, H.I.; Zamora, C.M.; McCarthy, K.A.; Vogel, J.R.; Wilson, J.T.</p> <p>2008-01-01</p> <p>Estimates of streambed water flux are needed for the interpretation of streambed chemistry and reactions. Continuous temperature and head monitoring in stream reaches within four agricultural watersheds (Leary Weber Ditch, IN; Maple Creek, NE; DR2 Drain, WA; and Merced River, CA) allowed heat to be used as a tracer to study the temporal and spatial variability of fluxes through the streambed. Synoptic methods (seepage meter and differential discharge measurements) were compared with estimates obtained by using heat as a tracer. Water flux was estimated by modeling one-dimensional vertical flow of water and heat using the model VS2DH. Flux was influenced by physical heterogeneity of the stream channel and temporal variability in stream and ground-water levels. During most of the study period (April-December 2004), flux was upward through the streambeds. At the IN, NE, and CA sites, high-stage events resulted in rapid reversal of flow direction inducing short-term surface-water flow into the streambed. During late summer at the IN site, regional ground-water levels dropped, leading to surface-water loss to ground water that resulted in drying of the ditch. Synoptic measurements of flux generally supported the model flux estimates. Water flow through the streambed was roughly an order of magnitude larger in the humid basins (IN and NE) than in the arid basins (WA and CA). Downward flux, in response to sudden high streamflows, and seasonal variability in flux was most pronounced in the humid basins and in high conductivity zones in the streambed. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2006/5231/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2006/5231/"><span>Nutrient and Suspended-Sediment Trends in the Missouri River Basin, 1993-2003</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Sprague, Lori A.; Clark, Melanie L.; Rus, David L.; Zelt, Ronald B.; Flynn, Jennifer L.; Davis, Jerri V.</p> <p>2007-01-01</p> <p>Trends in streamflow and concentration of total nitrogen, nitrite plus nitrate, ammonia, total phosphorus, orthophosphorus, and suspended sediment were determined for the period from 1993 to 2003 at selected stream sites in the Missouri River Basin. Flow-adjusted trends in concentration (the trends that would have occurred in the absence of natural changes in streamflow) and non-flow-adjusted trends in concentration (the overall trends resulting from natural and human factors) were determined. In the analysis of flow-adjusted trends, the removal of streamflow as a variable affecting concentration allowed trends caused by other factors such as implementation of best management practices to be identified. In the analysis of non-flow-adjusted trends, the inclusion of any and all factors affecting concentration allowed trends affecting aquatic ecosystems and the status of streams relative to water-quality standards to be identified. Relations between the flow-adjusted and non-flow-adjusted trends and changes in streamflow, nutrient sources, ground-water inputs, and implementation of management practices also were examined to determine the major factors affecting the trends. From 1993 to 2003, widespread downward trends in streamflow indicated that drought conditions from about 2000 to 2003 led to decreasing streamflow throughout much of the Missouri River Basin. Flow-adjusted trends in nitrite plus nitrate and ammonia concentrations were split nearly equally between nonsignificant and downward; at about one-half of the sites, management practices likely were contributing to measurable decreases in concentrations of nitrite plus nitrate and ammonia. Management practices had less of an effect on concentrations of total nitrogen; downward flow-adjusted trends in total nitrogen concentrations occurred at only 2 of 19 sites. The pattern of non-flow-adjusted trends in nitrite plus nitrate concentrations was similar to the pattern of flow-adjusted trends; non-flow-adjusted trends were split nearly equally between nonsignificant and downward. A substantial source of nitrite plus nitrate to these streams likely was ground water; because of the time required for ground water to travel to streams, there may have been a lag time between the implementation of some pollution-control strategies and improvement in stream quality, contributing to the nonsignificant trends in nitrite plus nitrate. There were more sites with downward non-flow-adjusted trends than flow-adjusted trends in both ammonia and total nitrogen concentrations, possibly a result of decreased surface runoff from nonpoint sources associated with the downward trends in streamflow. No strong relations between any of the nitrogen trends and changes in nutrient sources or landscape characteristics were identified. Although there were very few upward trends in nitrogen from 1993 to 2003, there were upward flow-adjusted trends in total phosphorus concentrations at nearly one-half of the sites. At these sites, not only were pollution-control strategies not contributing to measurable decreases in total phosphorus concentrations, there was likely an increase in phosphorus loading on the land surface. There were fewer upward non-flow-adjusted than flow-adjusted trends in total phosphorus concentrations; at the majority of sites, overall total phosphorus concentrations did not change significantly during this period. The preponderance of upward flow-adjusted trends and nonsignificant non-flow-adjusted trends indicates that in some areas of the Missouri River Basin, overall concentrations of total phosphorus would have been higher without the decrease in streamflow and the associated decrease in surface runoff during the study period. During the study period, phosphorus loads from fertilizer generally increased at over one-half of the sites in the basin. Upward flow-adjusted trends were related to increasing fertilizer use in the upstream drainage area, particularly in the 10 percent</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70040116','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70040116"><span>Trends and shifts in streamflow in Hawaii, 1913-2008</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Bassiouni, Maoya; Oki, Delwyn S.</p> <p>2013-01-01</p> <p>This study addresses a need to document changes in streamflow and base flow (groundwater discharge to streams) in Hawai'i during the past century. Statistically significant long-term (1913-2008) downward trends were detected (using the nonparametric Mann-Kendall test) in low-streamflow and base-flow records. These long-term downward trends are likely related to a statistically significant downward shift around 1943 detected (using the nonparametric Pettitt test) in index records of streamflow and base flow. The downward shift corresponds to a decrease of 22% in median streamflow and a decrease of 23% in median base flow between the periods 1913-1943 and 1943-2008. The shift coincides with other local and regional factors, including a change from a positive to a negative phase in the Pacific Decadal Oscillation, shifts in the direction of the trade winds over Hawai'i, and a reforestation programme. The detected shift and long-term trends reflect region-wide changes in climatic and land-cover factors. A weak pattern of downward trends in base flows during the period 1943-2008 may indicate a continued decrease in base flows after the 1943 shift. Downward trends were detected more commonly in base-flow records than in high-streamflow, peak-flow, and rainfall records. The decrease in base flow is likely related to a decrease in groundwater storage and recharge and therefore is a valuable indicator of decreasing water availability and watershed vulnerability to hydrologic changes. Whether the downward trends will continue is largely uncertain given the uncertainty in climate-change projections and watershed responses to changes.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018HMT....54.1177E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018HMT....54.1177E"><span>An experimental study of solar desalination using free jets and an auxiliary hot air stream</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Eid, Eldesouki I.; Khalaf-Allah, Reda A.; Dahab, Mohamed A.</p> <p>2018-04-01</p> <p>An experimental study for a solar desalination system based on jet-humidification with an auxiliary perpendicular hot air stream was carried out at Suez city, Egypt 29.9668°N, 32.5498°E. The tests were done from May to October 2016. The effects of nozzles situations and nozzle diameter with and without hot air stream on fresh water productivity were monitored. The results show that; the lateral and downward jets from narrow nozzles have more productivities than other situations. The hot air stream has to be adapted at a certain flow rate to get high values of productivity. The system productivity is (5.6 L/m 2 ), the estimated cost is (0.030063 / L) and the efficiency is 32.8%.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70031545','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70031545"><span>Fate and identification of oil-brine contamination in different hydrogeologic settings</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Whittemore, Donald O.</p> <p>2007-01-01</p> <p>Past disposal of oil-field brine at the surface has caused substantial contamination of water resources in Kansas. Natural saline water occurs in and discharges from Permian bedrock in parts of the state, and other anthropogenic sources of saline water exist, requiring clear identification of different sources. Time-series analysis of Cl- concentration and streamflow relative to pre-contamination contents, and end-member mixing plots, especially for Br- and Cl-, are practical methods for source differentiation and quantification. Although regulations preventing escape of saltwater from oil wells were first passed in Kansas in 1935, much oil and gas brine was disposed on the surface through the 1940s. Hydrogeologic characteristics of the areas with past surface disposal of oil brine differ appreciably and result in large differences in the ratio of saltwater transported in streams or ground water. Much of the brine disposed during the 1910s to 1940s in an area of silty clay soils overlying shale and limestone bedrock in south-central Kansas soon ran off or was flushed from the surface by rain into streams. Chloride concentration in the rivers draining this area often exceeded 1000 mg/L after the start of oil production up to the 1950s. Chloride content in the rivers then generally declined to about 100 mg/L or less in recent low flows. Oil brine was also disposed in surface ponds overlying the unconsolidated High Plains aquifer in south-central Kansas from the latter 1920s into the 1940s. Most of the surface-disposed brine infiltrated to the underlying aquifer. Where the High Plains aquifer is thin, saltwater has migrated along the top of clay layers or the underlying shaly bedrock and either discharged into small streams or flowed into thicker parts of the aquifer. Where the aquifer is thick, surface-disposed oil brine moved downward until reaching clay lenses, migrated latterly to the edge of the clay, and again moved downward if still dense enough. Water-level declines from pumping have increased the lateral migration rate of the saltwater contamination in the aquifer towards water-supply wells. The period of flushing most of the surface-disposed saltwater from the area of shale and limestone bedrock is on the order of many decades but is at least many centuries for the deeper parts of the High Plains aquifer. ?? 2007 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/24802','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/24802"><span>Potentiometric map of the Winona-Tallahatta Aquifer in northwestern Mississippi, fall 1979</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wasson, B.E.</p> <p>1980-01-01</p> <p>The potentiometric map of the Winona-Tallahatta aquifer is one of a series of maps, prepared by the U.S. Geological Survey in cooperation with the Mississippi Department of Natural Resources , Bureau of Land and Water Resources, delineating the potentiometric surfaces of the major aquifers in Mississippi. In the outcrop area of the Winona-Tallahatta aquifer the potentiometric surface is strongly affected by recharge from precipitation, by topography, and by drainage of the aquifer by streams. The potentiometric surface slopes downward generally to the west away from the area of outcrop and is strongly affected by recharge from precipitation, by topography, and by drainage of the aquifer by streams. The potentiometric surface slopes downward generally to the west away from the area of outcrop and is strongly affected by pumpage from wells in Leflore, Sunflower , and Bolivar Counties, Historically, water levels in or near the outcrop of the Winona-Tallahatta have shown little or no long-term changes, but the heavy withdrawals in the confined part of the aquifer have caused long-term water-level declines of 1 to 2 feet per year. (USGS)</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2011/5114/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2011/5114/"><span>Nutrient concentrations and loads in the northeastern United States - Status and trends, 1975-2003</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Trench, Elaine C. Todd; Moore, Richard B.; Ahearn, Elizabeth A.; Mullaney, John R.; Hickman, R. Edward; Schwarz, Gregory E.</p> <p>2012-01-01</p> <p>The U.S. Geological Survey (USGS) National Water-Quality Assessment Program (NAWQA) began regional studies in 2003 to synthesize information on nutrient concentrations, trends, stream loads, and sources. In the northeastern United States, a study area that extends from Maine to central Virginia, nutrient data were evaluated for 130 USGS water-quality monitoring stations. Nutrient data were analyzed for trends in flow-adjusted concentrations, modeled instream (non-flow-adjusted) concentrations, and stream loads for 32 stations with 22 to 29 years of water-quality and daily mean streamflow record during 1975-2003 (termed the long-term period), and for 46 stations during 1993-2003 (termed the recent period), by using a coupled statistical model of streamflow and water quality developed by the USGS. Recent trends in flow-adjusted concentrations of one or more nutrients also were analyzed for 90 stations by using Tobit regression. Annual stream nutrient loads were estimated, and annual nutrient yields were calculated, for 47 stations for the long-term and recent periods, and for 37 additional stations that did not have a complete streamflow and water-quality record for 1993-2003. Nutrient yield information was incorporated for 9 drainage basins evaluated in a national NAWQA study, for a total of 93 stations evaluated for nutrient yields. Long-term downward trends in flow-adjusted concentrations of total nitrogen and total phosphorus (18 and 19 of 32 stations, respectively) indicate regional improvements in nutrient-related water-quality conditions. Most of the recent trends detected for total phosphorus were upward (17 of 83 stations), indicating possible reversals to the long-term improvements. Concentrations of nutrients in many streams persist at levels that are likely to affect aquatic habitat adversely and promote freshwater or coastal eutrophication. Recent trends for modeled instream concentrations, and modeled reference concentrations, were evaluated relative to ecoregion-based nutrient criteria proposed by the U.S. Environmental Protection Agency. Instream concentrations of total nitrogen and total phosphorus persist at levels higher than proposed criteria at more than one-third and about one-half, respectively, of the 46 stations analyzed. Long-term trends in nutrient loads were primarily downward, with downward trends in total nitrogen and total phosphorus loads detected at 12 and 17 of 32 stations, respectively. Upward trends were rare, with one upward trend for total nitrogen loads and none for total phosphorus. Trends in loads of nitrite-plus-nitrate nitrogen included 7 upward and 8 downward trends among 32 stations. Downward trends in loads of ammonia nitrogen and total Kjeldahl nitrogen were detected at all six stations evaluated. Long-term downward trends detected in four of the five largest drainage basins evaluated include: total nitrogen loads for the Connecticut, Delaware, and James Rivers; total Kjeldahl nitrogen and ammonia nitrogen loads for the Susquehanna River; ammonia nitrogen and nitrite-plus-nitrate nitrogen loads for the James River; and total phosphorus loads for the Connecticut and Delaware Rivers. No trends in load were detected for the Potomac River. Nutrient yields were evaluated relative to the extent of land development in 93 drainage basins. The undeveloped land-use category included forested drainage basins with undeveloped land ranging from 75 to 100 percent of basin area. Median total nitrogen yields for the 27 undeveloped drainage basins evaluated, including 9 basins evaluated in a national NAWQA study, ranged from 290 to 4,800 pounds per square mile per year (lb/mi2/yr). Total nitrogen yields even in the most pristine drainage basins may be elevated relative to natural conditions, because of high rates of atmospheric deposition of nitrogen in parts of the northeastern United States. Median total phosphorus yields ranged from 12 to 330 lb/mi2/yr for the 26 undeveloped basins evaluated. The undeveloped category includes some large drainage basins with point-source discharges and small percentages of developed land; in these basins, streamflow from undeveloped headwater areas dilutes streamflow in more urbanized reaches, and dampens but does not eliminate the point-source "signal" of higher nutrient loads. Median total nitrogen yields generally do not exceed 1,700 lb/mi2/yr, and median total phosphorus yields generally do not exceed 100 lb/mi2/yr, in the drainage basins that are least affected by human land-use and waste-disposal practices. Agricultural and urban land use has increased nutrient yields substantially relative to undeveloped drainage basins. Median total nitrogen yields for 24 agricultural basins ranged from 1,700 to 26,000 lb/mi2/yr, and median total phosphorus yields ranged from 94 to 1,000 lb/mi2/yr. The maximum estimated total nitrogen and total phosphorus yields, 32,000 and 16,000 lb/mi2/yr, respectively, for all stations in the region were in small (less than 50 square miles (mi2)) agricultural drainage basins. Median total nitrogen yields ranged from 1,400 to 17,000 lb/mi2/yr in 26 urbanized drainage basins, and median total phosphorus yields ranged from 43 to 1,900 lb/mi2/yr. Urbanized drainage basins with the highest nutrient yields are generally small (less than 300 mi2) and are drained by streams that receive major point-source discharges. Instream nutrient loads were evaluated relative to loads from point-source discharges in four drainage basins: the Quinebaug River Basin in Connecticut, Massachusetts, and Rhode Island; the Raritan River Basin in New Jersey; the Patuxent River Basin in Maryland; and the James River Basin in Virginia. Long-term downward trends in nutrient loads, coupled with similar trends in flow-adjusted nutrient concentrations, indicate long-term reductions in the delivery of most nutrients to these streams. However, the absence of recent downward trends in load for most nutrients, coupled with instream concentrations that exceed proposed nutrient criteria in several of these waste-receiving streams, indicates that challenges remain in reducing delivery of nutrients to streams from point sources. During dry years, the total nutrient load from point sources in some of the drainage basins approached or equaled the nutrient load transported by the stream.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950059018&hterms=Plasma+Ring&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DPlasma%2BRing','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950059018&hterms=Plasma+Ring&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DPlasma%2BRing"><span>Magnetosheath-ionspheric plasma interactions in the cusp/cleft. 2: Mesoscale particle simulations</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Winglee, R. M.; Menietti, J. D.; Lin, C. S.</p> <p>1993-01-01</p> <p>Ionospheric plasma flowing out from the cusp can be an important source of plasma to the magnetosphere. One source of free energy that can drive this outflow is the injection of magnetosheath plasma into the cusp. Two-dimensional (three velocity) mesoscale particle simulations are used to investigate the particle dynamics in the cusp during southward interplanetary magnetic field. This mesoscale model self-consistently incorporates (1) global influences such as the convection of plasma across the cusp, the action of the mirror force, and the injection of the magnetosheath plasma, and (2) wave-particle interactions which produce the actual coupling between the magnetosheath and ionospheric plasmas. It is shown that, because the thermal speed of the electrons is higher than the bulk motion of the magnetosheath plasma, an upward current is formed on the equatorward edge of the injection region with return currents on either side. However, the poleward return currents are the stronger due to the convection and mirroring of many of the magnetosheath electrons. The electron distribution in this latter region evolves from upward directed streams to single-sided loss cones or possibly electron conics. The ion distribution also shows a variety of distinct features that are produced by spatial and/or temporal effects associated with varying convection patterns and wave-particle interactions. On the equatorward edge the distribution has a downflowing magnetosheath component and an upflowing cold ionospheric component due to continuous convection of ionospheric plasma into the region. In the center of the magnetosheath region, heating from the development of an ion-ion streaming instability causes the suppression of the cold ionospheric component and the formation of downward ionospheric streams. Further poleward there is velocity filtering of ions with low pitch angles, so that the magnetosheath ions develop a ring-beam distribution and the ensuing wave instabilities generate downward ionospheric conics. These downward ionospheric components are eventually turned by the mirror force, leading to the production of upward conics at elevated energies throughout the region.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920056522&hterms=algae&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dalgae','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920056522&hterms=algae&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dalgae"><span>Hydrostatic factors affect the gravity responses of algae and roots</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Staves, Mark P.; Wayne, Randy; Leopold, A. C.</p> <p>1991-01-01</p> <p>The hypothesis of Wayne et al. (1990) that plant cells perceive gravity by sensing a pressure differential between the top and the bottom of the cell was tested by subjecting rice roots and cells of Caracean algae to external solutions of various densities. It was found that increasing the density of the external medium had a profound effect on the polar ratio (PR, the ratio between velocities of the downwardly and upwardly streaming cytoplasm) of the Caracean algae cells. When these cells were placed in solutions of denser compound, the PR decreased to less than 1, as the density of the external medium became higher than that of the cell; thus, the normal gravity-induced polarity was reversed, indicating that the osmotic pressure of the medium affects the cell's ability to respond to gravity. In rice roots, an increase of the density of the solution inhibited the rate of gravitropism. These results agree with predictions of a hydrostatic model for graviperception.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://pubs.usgs.gov/wri/2003/4197/wri20034197.pdf','USGSPUBS'); return false;" href="http://pubs.usgs.gov/wri/2003/4197/wri20034197.pdf"><span>Loads and yields of selected constituents in streams and rivers of Monroe County, New York, 1984-2001</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Sherwood, Donald A.</p> <p>2004-01-01</p> <p>Hydrologic data collected in Monroe County since the 1980s and earlier, including long-term records of streamflow and chemical loads, provide a basis for assessment of water-management practices. All monitored streams except Northrup Creek showed a slight (nonsignificant) overall decrease in annual streamflow over their period of record; Northrup Creek showed a slight increase.The highest yields of all constituents except chloride and sulfate were at Northrup Creek; these values exceeded those of the seven Irondequoit Creek basin sites and the Genesee River site. The highest yields of dissolved chloride were at the most highly urbanized site (Allen Creek), whereas the highest yields of dissolved sulfate were at the most upstream Irondequoit Creek sites -- Railroad Mills (active) and Pittsford (inactive). Yields of all constituents in the Genesee River at the Charlotte Pump Station were within the range of those at the Irondequoit Creek basin sites.The four active Irondequoit Creek basin sites showed significant downward trends in flow-adjusted loads of ammonia + organic nitrogen, possibly from the conversion of agricultural land to suburban land. Two active sites (Allen Creek and Blossom Road) and one inactive site (Thomas Creek) showed downward trends in loads of ammonia. All active sites showed significant upward trends in dissolved chloride loads. Northrup Creek showed a significant downward trend in total phosphorus load since the improvement in phosphorus removal at the Spencerport wastewater-treatment plant, and upward trends in dissolved chloride and sulfate loads. The Genesee River at the Charlotte Pump Station showed significant downward trends in loads of ammonia + organic nitrogen and chloride, and an upward trend in loads of orthophosphate.The improved treatment or diversion of sewage-treatment-plant-effluent has produced decreased yields of some constituents throughout the county, particularly in the Irondequoit Creek basin, where the loads of nutrients delivered to Irondequoit Bay have been decreased.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/wri/1984/4367/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/wri/1984/4367/report.pdf"><span>Water quality of Rhode Island streams</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Briggs, J.C.; Feiffer, J.S.</p> <p>1986-01-01</p> <p>Water quality data collected from November 1979 through September 1983 at five stream stations within Rhode Island and one in Massachusetts show that concentrations of the common constituents were low. Mean water hardness at all sites was in the ' soft ' category. Sodium concentrations were less than 20 mg/L at two sites and less than 35 mg/L at the other sites. Mean nitrogen values for the two Blackstone River sites were in the range that could cause undesirable growths of aquatic plants. Mean phosphorus values exceeded the recommended limits for protection of aquatic life at four sites. Trace-element concentrations in the water were generally low. Those trace elements which were found in concentrations near or exceeding any standard or criterion include cadmium, chromium, lead, iron, and manganese. High concentrations of several trace elements were found in the bottom materials at several sites. The bottom materials also contained pesticides and organic chemicals including aldrin, chlordane, DDD, DDE, DDT, dieldren, endosulfan , endrin, heptachlor, Mirex, and PCB. Results of trend analysis of total phosphorus, total nitrogen, and specific conductance show a downward trend in phosphorus at two sites; an upward trend in nitrogen at one site; and one downward trend and one upward trend in specific conductance. (USGS)</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70124919','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70124919"><span>Pesticides in U.S. streams and rivers: occurrence and trends during 1992-2011</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Stone, Wesley W.; Gilliom, Robert J.; Ryberg, Karen R.</p> <p>2014-01-01</p> <p>During the 20 years from 1992 to 2011, pesticides were found at concentrations that exceeded aquatic-life benchmarks in many rivers and streams that drain agricultural, urban, and mixed-land use watersheds. Overall, the proportions of assessed streams with one or more pesticides that exceeded an aquatic-life benchmark were very similar between the two decades for agricultural (69% during 1992−2001 compared to 61% during 2002−2011) and mixed-land-use streams (45% compared to 46%). Urban streams, in contrast, increased from 53% during 1992−2011 to 90% during 2002−2011, largely because of fipronil and dichlorvos. The potential for adverse effects on aquatic life is likely greater than these results indicate because potentially important pesticide compounds were not included in the assessment. Human-health benchmarks were much less frequently exceeded, and during 2002−2011, only one agricultural stream and no urban or mixed-land-use streams exceeded human-health benchmarks for any of the measured pesticides. Widespread trends in pesticide concentrations, some downward and some upward, occurred in response to shifts in use patterns primarily driven by regulatory changes and introductions of new pesticides.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.H42C..08B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.H42C..08B"><span>Thermal Variability in Gravel Bars and its Potential Consequences for CO2 Evasion from Alpine Coldwater Streams</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boodoo, K. S.; Schelker, J.; Battin, T. J.</p> <p>2016-12-01</p> <p>Gravel bars (GB) are ubiquitous in-stream structures with relatively large exposed surfaces, capable of absorbing heat and possibly acting as a heat source to the underlying hyporheic zone (HZ). The distinctive mixing of groundwater and surface water within their HZ largely determines its characteristic physical and biogeochemical properties, including temperature distribution. To study thermal variability within GBs and its possible consequences for CO2 evasion fluxes we analysed high frequency spatio-temporal data for a range of stream and atmospheric physical parameters including the vertical GB temperature, in an Alpine cold water stream (Oberer Seebach, Austria) over the course of a year. We found the vertical temperature profiles within the GB to vary seasonally and with discharge. During warm summer months, diurnal vertical temperature patterns were most pronounced and were detected throughout all one-meter-depth profiles. Furthermore, permanently wetted GB sediment (-56 cm depth) temperatures above that of stream and groundwater occurred 17% of the year, particularly during summer. This is further evidence for downward heat transfer to the wetted HZ. Average CO2 flux from the GB was significantly higher than that of streamwater during summer and winter, with significantly higher temperatures and CO2 outgassing rates occurring at the GB tail as compared to streamwater and the head and mid of the GB throughout the year. Higher cumulative (over 6 h) GB temperatures were associated with increased CO2 evasion fluxes; the strength of the relationship increased with depth (max. r2 = 0.61 at -100cm depth). This enhanced CO2 flux may result from the input of warmer CO2-rich groundwater into the HZ in autumn and winter, while downward heat transfer in summer may enhance GB metabolism and therefore CO2 evasion. The importance of these processes is likely to increase, particularly in cold-water streams, due to the occurrence of more frequent and intense warm temperature events, as well as altered flow regimes, likely consequences of climatic change.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2013-08-27/pdf/2013-20786.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2013-08-27/pdf/2013-20786.pdf"><span>78 FR 52854 - Use of Differential Income Stream as an Application of the Income Method and as a Consideration...</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2013-08-27</p> <p>... Differential Income Stream as an Application of the Income Method and as a Consideration in Assessing the Best Method AGENCY: Internal Revenue Service (IRS), Treasury. ACTION: Final regulations and removal of... differential income stream as a consideration in assessing the best method in connection with a cost sharing...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li class="active"><span>2</span></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_2 --> <div id="page_3" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li class="active"><span>3</span></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="41"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2011-12-23/pdf/2011-32730.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2011-12-23/pdf/2011-32730.pdf"><span>76 FR 80309 - Use of Differential Income Stream as an Application of the Income Method and as a Consideration...</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2011-12-23</p> <p>... Use of Differential Income Stream as an Application of the Income Method and as a Consideration in Assessing the Best Method AGENCY: Internal Revenue Service (IRS), Treasury. ACTION: Notice of proposed... guidance on how an analysis of the differential income stream may provide a best method consideration for...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhDT........20R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhDT........20R"><span>Optimization and Modeling of Noise Reduction for Turbulent Jets with Induced Asymmetry</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rostamimonjezi, Sara</p> <p></p> <p>This project relates to the development of next-generation high-speed aircraft that are efficient and environmentally compliant. The emphasis of the research is on reducing noise from high-performance engines that will power these aircraft. A strong component of engine noise is jet mixing noise that comes from the turbulent mixing process between the high-speed exhaust flow of the engine and the atmosphere. The fan flow deflection method (FFD) suppresses jet noise by deflecting the fan stream downward, by a few degrees, with respect to the core stream. This reduces the convective Mach number of the primary shear layer and turbulent kinetic energy in the downward direction and therefore reduces the noise emitted towards the ground. The redistribution of the fan stream is achieved with inserting airfoil-shaped vanes inside the fan duct. Aerodynamic optimization of FFD has been done by Dr. Juntao Xiong using a computational fluid dynamics code to maximize reduction of noise perceived by the community while minimizing aerodynamic losses. The optimal vane airfoils are used in a parametric experimental study of 50 4-vane deflector configurations. The vane chord length, angle of attack, and azimuthal location are the parameters studied in acoustic optimization. The best vane configuration yields a reduction in cumulative (downward + sideline) effective perceived noise level (EPNL) of 5.3 dB. The optimization study underscores the sensitivity of FFD to deflector parameters and the need for careful design in the practical implementation of this noise reduction approach. An analytical model based on Reynolds Averaged Navier Stokes (RANS) and acoustic analogy is developed to predict the spectral changes from a known baseline in the direction of peak emission. A generalized form for space-time correlation is introduced that allows shapes beyond the traditional exponential forms. Azimuthal directivity based on the wavepacket model of jet noise is integrated with the acoustic analogy model. A physics-based definition of convective Mach number is proposed. The predicted noise reduction is in reasonable agreement with the experiments. The study underscores the importance of a proper definition of convective Mach number when modeling noise in the direction of peak emission.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JASTP.171...94P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JASTP.171...94P"><span>Tropospheric weather influenced by solar wind through atmospheric vertical coupling downward control</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Prikryl, Paul; Bruntz, Robert; Tsukijihara, Takumi; Iwao, Koki; Muldrew, Donald B.; Rušin, Vojto; Rybanský, Milan; Turňa, Maroš; Šťastný, Pavel</p> <p>2018-06-01</p> <p>Occurrence of severe weather in the context of solar wind coupling to the magnetosphere-ionosphere-atmosphere (MIA) system is investigated. It is observed that significant snowfall, wind and heavy rain, particularly if caused by low pressure systems in winter, tend to follow arrivals of high-speed solar wind. Previously published statistical evidence that explosive extratropical cyclones in the northern hemisphere tend to occur within a few days after arrivals of high-speed solar wind streams from coronal holes (Prikryl et al., 2009, 2016) is corroborated for the southern hemisphere. Cases of severe weather events are examined in the context of the magnetosphere-ionosphere-atmosphere (MIA) coupling. Physical mechanism to explain these observations is proposed. The leading edge of high-speed solar wind streams is a locus of large-amplitude magneto-hydrodynamic waves that modulate Joule heating and/or Lorentz forcing of the high-latitude lower thermosphere generating medium-scale atmospheric gravity waves that propagate upward and downward through the atmosphere. Simulations of gravity wave propagation in a model atmosphere using the Transfer Function Model (Mayr et al., 1990) reveal that propagating waves originating in the lower thermosphere can excite a spectrum of gravity waves in the lower atmosphere. In spite of significantly reduced amplitudes but subject to amplification upon reflection in the upper troposphere, these gravity waves can provide a lift of unstable air to release instabilities in the troposphere and initiate convection to form cloud/precipitation bands. It is primarily the energy provided by release of latent heat that leads to intensification of storms. These results indicate that vertical coupling in the atmosphere exerts downward control from solar wind to the lower atmospheric levels influencing tropospheric weather development.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/fs/2004/3104/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/fs/2004/3104/"><span>Trends in Streamflow Characteristics in Hawaii, 1913-2002</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Oki, Delwyn S.</p> <p>2004-01-01</p> <p>The surface-water resources of Hawaii have significant cultural, aesthetic, ecologic, and economic importance. In Hawaii, surface-water resources are developed for both offstream uses (for example, drinking water, agriculture, and industrial uses) and instream uses (for example, maintenance of habitat and ecosystems, recreational activities, aesthetic values, maintenance of water quality, conveyance of irrigation and domestic water supplies, and protection of traditional and customary Hawaiian rights). Possible long-term trends in streamflow characteristics have important implications for water users, water suppliers, resource managers, and citizens in the State. Proper management of Hawaii's streams requires an understanding of long-term trends in streamflow characteristics and their potential implications. Effects of long-term downward trends in low flows in streams include potential loss of habitat for native stream fauna and reduced water availability for offstream and instream water uses. Effects of long-term upward trends in high flows in streams include construction of bridges and water-conveyance structures that are potentially unsafe if they are not designed with proper consideration of trends in high flows.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2010/5139/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2010/5139/"><span>Trends in pesticide concentrations in urban streams in the United States, 1992-2008</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Ryberg, Karen R.; Vecchia, Aldo V.; Martin, Jeffrey D.; Gilliom, Robert J.</p> <p>2010-01-01</p> <p>Pesticide concentration trends in streams dominated by urban land use were assessed using data from 27 urban streams sampled as part of the U.S. Geological Survey National Water-Quality Assessment Program. The sites were divided into four regions, Northeast, South, Midwest, and West, to examine possible regional patterns. Three partially overlapping 9-year periods (1992-2000, 1996-2004, and 2000-2008) were examined for eight herbicides and one degradation product (simazine, prometon, atrazine, deethylatrazine, metolachlor, trifluralin, pendimethalin, tebuthiuron, and Dacthal), and five insecticides and two degradation products (chlorpyrifos, malathion, diazinon, fipronil, fipronil sulfide, desulfinylfipronil, and carbaryl). The data were analyzed for trends in concentration using a parametric regression model with seasonality, flow-related variability, and trend, called SEAWAVE-Q. The SEAWAVE-Q model also was used to generate estimated daily concentration percentiles for each analysis period to provide a summary of concentration magnitudes. For herbicides, the largest 90th percentiles of estimated concentrations for simazine were in the South, prometon at some sites in all of the regions, atrazine and deethylatrazine in the South and Midwest, metolachlor in the Midwest and a few sites in the South, pendimethalin at scattered sites in all of the regions, and tebuthiuron in the South and a few sites in the Midwest and West. For insecticides, the largest 90th percentiles of estimated concentrations for diazinon and carbaryl were distributed among various sites in all regions (especially during 1996-2004), and fipronil at isolated sites in all of the regions during 2000-2008. Trend analysis results for the herbicides indicated many significant trends, both upward and downward, with varying patterns depending on period, region, and herbicide. Overall, deethylatrazine showed the most consistent pattern of upward trends, especially in the Northeast (2000-2008), South (1996-2004 and 2000-2008), and Midwest (1996-2004 and 2000-2008). Other herbicides showed less consistent upward trends, including simazine in the South (1996-2004), prometon in the Midwest (2000-2008), and atrazine in the South (1996-2004). The most consistent downward trends were for simazine in the Northeast and Midwest (1996-2004), prometon in the Northeast and Midwest (1996-2004) and West (1996-2004 and 2000-2008), and tebuthiuron in the South (1996-2004 and 2000-2008) and West (2000-2008). Strong similarity existed between the trends for atrazine and deethylatrazine during 1996-2004. During 2000-2008, however, there were mixed upward and downward trends in atrazine and predominantly upward trends in deethylatrazine. Ten sites with a downward trend in atrazine were paired with an upward trend in deethylatrazine and for three of these sites (1 in the South and 2 in the Midwest) both opposing trends were significant. Opposing trends showing a decrease in atrazine and an increase in deethylatrazine may indicate that decreases in atrazine from surface runoff are being offset in some cases by increases in deethylatrazine from groundwater for the latter analysis period. Trend results for insecticides indicated widespread significant downward trends for chlorpyrifos (especially 1996-2004), diazinon (1996-2004 and 2000-2008), and malathion (especially 1996-2004); widespread significant upward trends for fipronil and its degradation products (2000-2008); and mostly nonsignificant trends for carbaryl (1996-2004 and 2000-2008). The downward trends for chlorpyrifos and diazinon were consistent with the regulatory phaseout of residential uses of these insecticides and the upward trends for fipronil and its degradation products were consistent with its introduction in 1996 and subsequent increasing use as a possible substitute for chlorpyrifos and diazinon. The downward trends in malathion may be caused by voluntary substitution of pyrethroids or fipronil for malathio</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://pubs.water.usgs.gov/ofr2005-1269/','USGSPUBS'); return false;" href="http://pubs.water.usgs.gov/ofr2005-1269/"><span>Water resources in a rapidly growing region-Oakland County, Michigan</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Aichele, Stephen S.</p> <p>2005-01-01</p> <p>Despite considerable expansion of urban areas, streamflow characteristics at most sites have not been affected. However, at several sites in areas of the county that are both supplied by ground water and sewered, statistically significant downward trends in low-flow stream discharges have been noted between 1970 and 2003. Stream chemistry, compared to a previous study of county water resources prepared in 1972, has generally improved, with marked decreases in concentrations of nitrogen, phosphorus, and sulfate. Chloride concentrations, however, have increased dramatically in river and lake water across the county. Detectable concentrations of personal-care products, flame retardants, and petroleum fuel compounds were identified at all river sites sampled. </p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2016/5176/sir20165176.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2016/5176/sir20165176.pdf"><span>Trends in the quality of water in New Jersey streams, water years 1971–2011</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hickman, R. Edward; Hirsch, Robert M.</p> <p>2017-02-27</p> <p>In a study conducted by the U.S. Geological Survey in cooperation with the New Jersey Department of Environmental Protection and the Delaware River Basin Commission, trend tests were conducted on selected water-quality characteristics measured at stations on streams in New Jersey during selected periods over water years 1971‒2011. Tests were conducted on 3 nutrients (total nitrogen, filtered nitrate plus nitrite, and total phosphorus) at 28 water-quality stations. At 4 of these stations, tests were also conducted on 3 measures of major ions (specific conductance, filtered chloride, and total dissolved solids).Two methods were used to identify trends—Weighted Regressions on Time, Discharge, and Season (WRTDS) models and seasonal rank-sum tests. For this report, the use of WRTDS models included the use of the WRTDS Bootstrap Test (WBT). WRTDS models identified trends in flow-normalized annual concentrations and flow-normalized annual fluxes over water years 1980‒2011 and 2000‒11 for each nutrient, filtered chloride, and total dissolved solids. WRTDS models were developed for each nutrient at the 20 or 21 stations at which streamflow was measured or estimated. Trends in nutrient concentration were reported for these stations; trends in nutrient fluxes were reported only for 15–17 of these stations.The results of WRTDS models for water years 1980‒2011 identified more stations with downward trends in concentrations of either total nitrogen or total phosphorus than upward trends. For total nitrogen, there were downward trends at 9 stations and an upward trend at 1 station. For total phosphorus, there were downward trends at 8 stations and an upward trend at 1 station. For filtered nitrate plus nitrite, there were downward trends at 6 stations and upward trends at 6 stations. The result of the trend test in flux for a selected nutrient at a selected station (downward trend, no trend, or upward trend) usually matched the trend result in concentration.Seasonal rank-sum tests, the second method used, identified step trends in water-quality measured in different decades—1970s, 1980s, 1990s, and 2000s. Tests were conducted on all nutrients at 28 stations and on all measures of major ions at the 4 selected stations. Results of seasonal rank-sum tests between the 1980s and the 2000s identified more stations with downward trends in concentrations of total nitrogen (14) than stations with upward trends (2) and more stations with downward trends in concentrations of total phosphorus (18) than stations with upward trends (1).A combined dataset of trend results for concentrations over water years 1980‒2011 was created from the results of the two tests for the period. Results of WRTDS models were included in this combined dataset, if available. Otherwise, the results of the seasonal rank-sum tests between water-quality characteristics measured in the 1980s and 2000s were included.Trend results over water years 1980‒2011 in the combined dataset show that few of the 28 stations had upward trends in concentrations of either total nitrogen or total phosphorus. There were only 2 stations with upward trends in total nitrogen concentration and 1 station with an upward trend in total phosphorus concentration. Results for filtered nitrate plus nitrite show about the same number of stations with upward trends (9) as stations with downward trends (7). Results for all measures of major ions show upward trends at the four stations tested.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1415451','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1415451"><span>Gas stream analysis using voltage-current time differential operation of electrochemical sensors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Woo, Leta Yar-Li; Glass, Robert Scott; Fitzpatrick, Joseph Jay</p> <p></p> <p>A method for analysis of a gas stream. The method includes identifying an affected region of an affected waveform signal corresponding to at least one characteristic of the gas stream. The method also includes calculating a voltage-current time differential between the affected region of the affected waveform signal and a corresponding region of an original waveform signal. The affected region and the corresponding region of the waveform signals have a sensitivity specific to the at least one characteristic of the gas stream. The method also includes generating a value for the at least one characteristic of the gas stream basedmore » on the calculated voltage-current time differential.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005JHyd..304..274K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005JHyd..304..274K"><span>Nutrient pressures and ecological responses to nutrient loading reductions in Danish streams, lakes and coastal waters</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kronvang, Brian; Jeppesen, Erik; Conley, Daniel J.; Søndergaard, Martin; Larsen, Søren E.; Ovesen, Niels B.; Carstensen, Jacob</p> <p>2005-03-01</p> <p>The Danish National Aquatic Monitoring and Assessment Programme (NOVA) was launched in 1988 following the adoption of the first Danish Action Plan on the Aquatic Environment in 1987 with the aim to reduce by 50% the nitrogen (N) loading and by 80% the phosphorus (P) loading to the aquatic environment. The 14 years of experience gathered from NOVA have shown that discharges of total N (TN) and P (TP) from point sources to the Danish Aquatic Environment have been reduced by 69% (N) and 82% (P) during the period 1989 2002. Consequently, the P concentration has decreased markedly in most Danish lakes and estuaries. Considerable changes in agricultural practice have resulted in a reduction of the net N-surplus from 136 to 88 kg N ha-1 yr-1 (41%) and the net P-surplus from 19 to 11 kg P ha-1 yr-1 (42%) during the period 1985 2002. Despite these efforts Danish agriculture is today the major source of both N (>80%) and P (>50%) in Danish streams, lakes and coastal waters. A non-parametric statistical trend analysis of TN concentrations in streams draining dominantly agricultural catchments has shown a significant (p<0.05) downward trend in 48 streams with the downward trend being stronger in loamy compared to sandy catchments, and more pronounced with increasing dominance of agricultural exploitation in the catchments. In contrast, a statistical trend analysis of TP concentrations in streams draining agricultural catchments did not reveal any significant trends. The large reduction in nutrient loading from point and non-point sources has in general improved the ecological conditions of Danish lakes in the form of increased summer Secchi depth, decreased chlorophyll a and reduced phytoplankton biomass. Major changes have also occurred in the fish communities in lakes, with positive cascading effects on water quality. In Danish estuaries and coastal waters only a few significant improvements in the ecological quality have been observed, although it is expected that the observed reduced nutrient concentrations are likely to improve the ecological quality of estuaries and coastal waters in Denmark in the long term.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/21350390-two-phase-gas-liquid-flow-characteristics-inside-plate-heat-exchanger','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21350390-two-phase-gas-liquid-flow-characteristics-inside-plate-heat-exchanger"><span>Two-phase gas-liquid flow characteristics inside a plate heat exchanger</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Nilpueng, Kitti; Wongwises, Somchai</p> <p></p> <p>In the present study, the air-water two-phase flow characteristics including flow pattern and pressure drop inside a plate heat exchanger are experimentally investigated. A plate heat exchanger with single pass under the condition of counter flow is operated for the experiment. Three stainless steel commercial plates with a corrugated sinusoidal shape of unsymmetrical chevron angles of 55 and 10 are utilized for the pressure drop measurement. A transparent plate having the same configuration as the stainless steel plates is cast and used as a cover plate in order to observe the flow pattern inside the plate heat exchanger. The air-watermore » mixture flow which is used as a cold stream is tested in vertical downward and upward flow. The results from the present experiment show that the annular-liquid bridge flow pattern appeared in both upward and downward flows. However, the bubbly flow pattern and the slug flow pattern are only found in upward flow and downward flow, respectively. The variation of the water and air velocity has a significant effect on the two-phase pressure drop. Based on the present data, a two-phase multiplier correlation is proposed for practical application. (author)« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.H33J..08M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.H33J..08M"><span>Dynamics of groundwater-surface water interactions in urban streams</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Musolff, A.; Schmidt, C.; Fleckenstein, J. H.</p> <p>2010-12-01</p> <p>In industrialized countries the majority of streams and rivers have been subject to changes in the hydrological regime and alteration of the channel morphology. Urban streams are typically characterized by “flashier” hydrographs as a result of more direct runoff from impervious surfaces. Channel structure and complexity are often impaired compared to pristine streams. As a consequence the potential for bedform-driven water flow in the streambed is reduced. The downward transport of oxygen by advective flow in the streambed is known to be of great ecological importance for the hyporheic macro and micro fauna and facilitates nutrient cycling and the degradation of organic pollutants. We studied the dynamics of groundwater-surface water exchange of two anthropogenically impacted streams in urban areas to examine the effects of variable hydrologic boundary conditions on water flux and redox conditions in the streambed. The first stream is fed by groundwater as well as storm-water from a large industrial area. Here, we monitored the variability of vertical hydraulic gradients, streambed temperature and redox conditions in the streambed over the course of 5 months. The second stream is frequently polluted by combined sewer overflows (CSO) from an urban watershed. Here, we measured the vertical hydraulic gradients, streambed temperature and electrical conductivity (EC) in the stream, the streambed and in the adjacent aquifer. Both streams are characterized by strong variations in hydraulic gradients due to the dynamic hydrographs as well as the variations in total head in the shallow aquifer. Therefore, magnitude and direction of water flux through the streambed changed significantly over time. At the first site long-term variations of redox conditions in the shallow streambed (0.1 m) were related to the direction of water fluxes. Downward water flow resulted in increased redox potentials. However, the high short-term variability of redox conditions could not be directly attributed to changes in the hydraulic conditions. At the second site, increased EC in the shallow aquifer was related to seasonally losing conditions (associated with low water tables in summer) and the resulting groundwater recharge. Sudden increases in stream stage due to rain events and subsequent CSO resulted in altered streambed water fluxes, as evidenced by the disturbance of vertical streambed temperature profiles down to a depth of 0.3 m. Both, short-term and long-term variations in hydraulic gradients between the stream, the streambed and the groundwater were found to influence the magnitude and direction of water fluxes. Flashy flow events influence the water flux in the streambed very rapidly. However, changes in redox potential in the streambed require losing conditions over time scales longer than the duration of a typical high flow event. As a consequence, the complexity of water exchange in the streambed should be carefully monitored, both in space and time. Our results indicate that variable hydraulic gradients may induce intense exchange fluxes between the stream and streambed in urban streams and may compensate some of the negative consequences of degraded channels with limited bedform-driven flow.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://edg.epa.gov/metadata/catalog/search/resource/details.page?uuid=%7BB9CB1E5B-21D4-4DBD-A38F-22BF3C5A1BDF%7D','PESTICIDES'); return false;" href="https://edg.epa.gov/metadata/catalog/search/resource/details.page?uuid=%7BB9CB1E5B-21D4-4DBD-A38F-22BF3C5A1BDF%7D"><span>Change in the Magnitude of River Flooding in the United States, 1965-2015</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.epa.gov/pesticides/search.htm">EPA Pesticide Factsheets</a></p> <p></p> <p></p> <p>This figure shows changes in the size and frequency of flooding events in rivers and streams in the United States between 1965 and 2015. Blue upward-pointing symbols show locations where floods have become larger; brown downward-pointing symbols show locations where floods have become smaller. Data were analyzed by Louise Slater and Gabriele Villarini at the University of Iowa. For more information: www.epa.gov/climatechange/science/indicators</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19878006','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19878006"><span>Diversion of the urine stream by surgical modification of the preputial ostium in a dog.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pavletic, Michael M; Brum, Douglas E</p> <p>2009-11-01</p> <p>A 1.4-year-old sexually intact male Standard Poodle was evaluated with a history of urinating on its left forelimb and lower portion of the thorax. Physical examination revealed that the dog had an unusually elevated (tucked) abdominal wall and prominent dome-shaped thoracic wall. These anatomic changes altered the angle of the urine stream, resulting in the dog's soiling the xiphoid region of the thorax and left forelimb. The dorsal half of the preputial ostium was closed surgically to divert the urine stream in a ventral direction. The ventral portion of the ostium was reciprocally enlarged. Postoperatively, the dog urinated in a downward direction, eliminating urine contact with the body. The preputial orifice (ostium) plays an important role in the shape and direction of the urine stream exiting the penile urethra. Dogs with an elevated abdominal wall and prominent dome-shaped thorax may be prone to contamination of the lower portion of the thorax and forelimbs with urine during normal micturition. Partial closure of the dorsal preputial ostium, with reciprocal enlargement of the lower half of the orifice, can create a deflective barrier that effectively diverts the urine stream in a ventral direction.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11541058','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11541058"><span>The effect of the external medium on the gravity-induced polarity of cytoplasmic streaming in Chara corallina (Characeae).</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Staves, M P; Wayne, R; Leopold, A C</p> <p>1997-11-01</p> <p>Gravity induces a polarity of cytoplasmic streaming in vertical internodal cells of Chara such that the downwardly directed stream moves faster than the upwardly directed stream. In order to determine whether the statolith theory (in which intracellular sedimenting particles are responsible for gravity sensing) or the gravitational pressure theory (in which the entire protoplast acts as the gravity sensor) best explain the gravity response in Chara internodal cells, we controlled the physical properties of the external medium, including density and osmolarity, with impermeant solutes and examined the effect on the polarity of cytoplasmic streaming. As the density of the external medium is increased, the polarity of cytoplasmic streaming decreases and finally disappears when the density of the external medium is equal to that of the cell (1015 kg/m3). A further increase in the density of the external medium causes a reversal of the gravity response. These results are consistent with the gravitational pressure theory of gravity sensing since the buoyancy of the protoplast is dependent on the difference between the density of the protoplast and the external medium, and are inconsistent with the statolith theory since the buoyancy of intracellular particles are unaffected by changes in the external medium.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040089315&hterms=Streaming+Media&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DStreaming%2BMedia','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040089315&hterms=Streaming+Media&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DStreaming%2BMedia"><span>The effect of the external medium on the gravity-induced polarity of cytoplasmic streaming in Chara corallina (Characeae)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Staves, M. P.; Wayne, R.; Leopold, A. C.</p> <p>1997-01-01</p> <p>Gravity induces a polarity of cytoplasmic streaming in vertical internodal cells of Chara such that the downwardly directed stream moves faster than the upwardly directed stream. In order to determine whether the statolith theory (in which intracellular sedimenting particles are responsible for gravity sensing) or the gravitational pressure theory (in which the entire protoplast acts as the gravity sensor) best explain the gravity response in Chara internodal cells, we controlled the physical properties of the external medium, including density and osmolarity, with impermeant solutes and examined the effect on the polarity of cytoplasmic streaming. As the density of the external medium is increased, the polarity of cytoplasmic streaming decreases and finally disappears when the density of the external medium is equal to that of the cell (1015 kg/m3). A further increase in the density of the external medium causes a reversal of the gravity response. These results are consistent with the gravitational pressure theory of gravity sensing since the buoyancy of the protoplast is dependent on the difference between the density of the protoplast and the external medium, and are inconsistent with the statolith theory since the buoyancy of intracellular particles are unaffected by changes in the external medium.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920012481','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920012481"><span>Adjustable steam producing flexible orifice independent of fluid pressure</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Morrison, Andrew D. (Inventor)</p> <p>1992-01-01</p> <p>A self-adjusting choke for a fluids nozzle includes a membrane constructed of a single piece of flexible or elastic material. This flexible material is shaped to fit into the outlet of a nozzle. The body of the membrane has at least two flow channels, from one face to the other, which directs two streams of water to cross at the opening of the nozzle or at some point beyond. The elasticity and thickness of the membrane is selected to match the range of expected pressures and fluid velocities. The choke may have more than two flow channels, as long as they are aligned adjacent to one another and directed towards each other at the exit face. In a three orifice embodiment, one is directed upward, one is directed downward, and the one in the middle is directed forward. In this embodiment all three fluid streams intersect at some point past the nozzle opening. Under increased pressure the membrane will deform causing the orifices to realign in a more forward direction, causing the streams to intersect at a smaller angle. This reduces the force with which the separate streams impact each other, still allowing the separate streams to unify into a single stable spiralling stream in spite of the increased pressure.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1816761J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1816761J"><span>Measurements of Heavy Ion Differential Streaming with SOHO/CELIAS/CTOF and ACE/SWICS at 1 AU</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Janitzek, Nils; Berger, Lars; Taut, Andreas; Drews, Christian; Wimmer-Schweingruber, Robert</p> <p>2016-04-01</p> <p>Helios measurements in the early 1980s showed the existence of a systematic velocity difference, called "differential streaming", between solar wind bulk protons and alpha particles with the alphas streaming faster than the protons. The absolute differential speed between these species decreases with radial distance to the Sun and decreasing proton speed. In the fast wind it was measured to be approximately half of the local Alfvén speed. However, the detailed processes of acceleration and regulation of differential streaming are still not well understood. A proposed key process is resonant wave particle interaction between the ions and Alfvén waves near the ion-cyclotron frequency which is able to accelerate the alphas preferentially due to their higher mass-per-charge ratio. Measuring the differential speed of a wide set of solar wind heavy ions and therefore extending the mass-per-charge range significantly can provide additional information on the underlying processes that we cannot infer from the alphas and protons alone. We analysed data measured at L1 by SOHO/CELIAS/CTOF in 1996 and ACE/SWICS from 2001 to 2010. Both instruments are linear time-of-flight mass spectrometers which measure the ions' radial 1D velocity distributions with a cadence of 5 and 12 minutes, respectively. Comparing the mean ion speed, with the mean proton speed measured routinely by the SOHO/CELIAS/MTOF/PM and ACE/SWEPAM, respectively, we obtain the differential streaming for major charge states of solar wind carbon, oxygen, neon, magnesium, silicon and iron. In the case of the SWICS data the magnetometer on-board ACE (ACE/MAG) allows us to directly relate the differential streaming to the ambient Alfvén velocity while the lack of in-situ magnetic field measurements on SOHO is compensated by a B-field extrapolation from the WIND spacecraft (WIND/MAG) to the SOHO site. Both instruments show a similar result: significant differential streaming between heavy ions and protons on the order of the local Alfvén speed for solar wind above 400 km/s. While for slow solar wind the picture is more complex, the differential streaming is ubiquitous in the fast wind. Neither of the instruments measured a clear trend with ion mass-per-charge as would be expected from simple models including ion cyclotron resonance as the main driving process. Finally, we discuss a possible dependence of the differential streaming on the solar cycle.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28258340','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28258340"><span>Variability, trends, and teleconnections of stream flows with large-scale climate signals in the Omo-Ghibe River Basin, Ethiopia.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Degefu, Mekonnen Adnew; Bewket, Woldeamlak</p> <p>2017-04-01</p> <p>This study assesses variability, trends, and teleconnections of stream flow with large-scale climate signals (global sea surface temperatures (SSTs)) for the Omo-Ghibe River Basin of Ethiopia. Fourteen hydrological indices of variability and extremes were defined from daily stream flow data series and analyzed for two common periods, which are 1972-2006 for 5 stations and 1982-2006 for 15 stations. The Mann-Kendall's test was used to detect trends at 0.05 significance level, and simple correlation analysis was applied to evaluate associations between the selected stream flow indices and SSTs. We found weak and mixed (upward and downward) trend signals for annual and wet (Kiremt) season flows. Indices generated for high-flow (flood) magnitudes showed the same weak trend signals. However, trend tests for flood frequencies and low-flow magnitudes showed little evidences of increasing change. It was also found that El Niño-Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) are the major anomalies affecting stream flow variability in the Omo-Ghibe Basin. The strongest associations are observed between ENSO/Niño3.4 and the stream flow in August and September, mean Kiremt flow (July-September), and flood frequency (peak over threshold on average three peaks per year (POT3_Fre)). The findings of this study provide a general overview on the long-term stream flow variability and predictability of stream flows for the Omo-Ghibe River Basin.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1915405B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1915405B"><span>Gravel bar thermal variability and its potential consequences for CO2 evasion from Alpine coldwater streams</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boodoo, Kyle; Battin, Tom; Schelker, Jakob</p> <p>2017-04-01</p> <p>Gravel bars (GB) are ubiquitous in-stream structures with relatively large exposed surfaces, capable of absorbing heat and possibly acting as a heat source to the underlying hyporheic zone (HZ). The distinctive mixing of groundwater and surface water within their HZ largely determines its characteristic physical and biogeochemical properties, including temperature distribution. To study thermal variability within GBs and its possible consequences for CO2 evasion fluxes we analysed high frequency spatio-temporal data for a range of stream and atmospheric physical parameters including the vertical GB temperature, in an Alpine cold water stream (Oberer Seebach, Austria) over the course of a year. We found the vertical temperature profiles within the GB to vary seasonally and with discharge. We extended our study to 13 other gravel bars of varying physical characteristics within the surrounding Ybbs and Erlauf catchments, conducting diurnal spot samplings in summer 2016. Temperatures within the observed permanently wetted hyporheic zone (-56 to -100cm depth below GB surface) of the OSB, were warmer than both end members, surface water and groundwater >18% of the year, particularly during summer. There was a general increase in exceedance within the periodically wetted gravel bar sediment toward the gravel bar surface, further evidencing downward heat transfer to the wetted HZ. Average CO2 flux from the GB was significantly higher than that of streamwater during summer and winter, with significantly higher temperatures and CO2 outgassing rates occurring at the GB tail as compared to streamwater and the head and mid of the GB throughout the year. Higher cumulative (over 6 h) GB seasonal temperatures were associated with increased CO2 evasion fluxes within the OSB, particularly during summer. This enhanced CO2 flux may result from the input of warmer CO2-rich groundwater into the HZ in autumn, while downward heat transfer in summer may enhance GB metabolism and therefore CO2 evasion. Furthermore, catchment CO2 outgassing fluxes significantly exceeded that of the stream, with higher diurnal CO2 outgassing fluxes observed for all 13 GBs within the Ybbs and Erlauf catchments as compared to their respective streams. We found DOC concentration did not significantly correlate to CO2 outgassing. But, vertical temperature gradient as a measure of heat flux to the hyporheic zone explained 55% and 69% of the variability in observed CO2 efflux from the OSB gravel bar (seasonal samplings during summer 2015 - winter 2016) and 11 catchment gravel bars (2 GBs excluded due to equipment malfunction) respectively. These results highlight the effect of temperature on physical and biochemical stream processes, particularly in cold-water streams, due to the occurrence of more frequent and intense warm temperature events, as well as altered flow regimes, likely consequences of climatic change.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhFl...28k2102K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhFl...28k2102K"><span>Dynamics of immiscible liquids in a rotating horizontal cylinder</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kozlov, N. V.; Kozlova, A. N.; Shuvalova, D. A.</p> <p>2016-11-01</p> <p>The dynamics of an interface between two immiscible liquids of different density is studied experimentally in a horizontal cylinder at rotation in the gravity field. Two liquids entirely fill the cavity volume, and the container is rotated sufficiently fast so that the liquids are centrifuged. The light liquid forms a column extended along the rotation axis, and the heavy liquid forms an annular layer. Under the action of gravity, the light liquid column displaces steadily along the radius, downwards in the laboratory frame. As a result, fluid oscillations in the cavity frame are excited at the interface, which lead to the generation of a steady streaming, and the fluid comes into a slow lagging rotation with respect to the cylinder walls. The dynamics of the studied system is determined by the ratio of the gravity acceleration to the centrifugal one—the dimensionless acceleration. In experiments, the system is controlled by the means of variation of the rotation rate, i.e., of the centrifugal force. At a critical value of the dimensionless acceleration the circular interface looses stability, and an azimuthal wave is excited. This leads to a strong increase in the interface differential velocity. A theoretical analysis is done based on the theory of centrifugal waves and a frequency equation is obtained. Experimental results are in good agreement with the theory at the condition of small wave amplitudes. Mechanism of steady streaming generation is analyzed based on previously published theoretical results obtained for the limiting case when the light phase is a solid cylinder. A qualitative agreement is found.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li class="active"><span>3</span></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_3 --> <div id="page_4" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active"><span>4</span></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="61"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70016669','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70016669"><span>Stream-floodwave propagation through the Great Bend alluvial aquifer, Kansas: Field measurements and numerical simulations</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Sophocleous, M.A.</p> <p>1991-01-01</p> <p>The hypothesis is explored that groundwater-level rises in the Great Bend Prairie aquifer of Kansas are caused not only by water percolating downward through the soil but also by pressure pulses from stream flooding that propagate in a translatory motion through numerous high hydraulic diffusivity buried channels crossing the Great Bend Prairie aquifer in an approximately west to east direction. To validate this hypothesis, two transects of wells in a north-south and east-west orientation crossing and alongside some paleochannels in the area were instrumented with water-level-recording devices; streamflow data from all area streams were obtained from available stream-gaging stations. A theoretical approach was also developed to conceptualize numerically the stream-aquifer processes. The field data and numerical simulations provided support for the hypothesis. Thus, observation wells located along the shoulders or in between the inferred paleochannels show little or no fluctuations and no correlations with streamflow, whereas wells located along paleochannels show high water-level fluctuations and good correlation with the streamflows of the stream connected to the observation site by means of the paleochannels. The stream-aquifer numerical simulation results demonstrate that the larger the hydraulic diffusivity of the aquifer, the larger the extent of pressure pulse propagation and the faster the propagation speed. The conceptual simulation results indicate that long-distance propagation of stream floodwaves (of the order of tens of kilometers) through the Great Bend aquifer is indeed feasible with plausible stream and aquifer parameters. The sensitivity analysis results indicate that the extent and speed of pulse propagation is more sensitive to variations of stream roughness (Manning's coefficient) and stream channel slope than to any aquifer parameter. ?? 1991.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960014064','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960014064"><span>Two-stream modeling of plasmaspheric refilling</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Guiter, S. M.; Gombosi, T. I.; Rasmussen, C. E.</p> <p>1995-01-01</p> <p>Plasmaspheric refilling on an L = 4 flux tube was studied by using a time-dependent, hydrodynamic plasmaspheric flow model in which the ion streams from the two hemispheres are treated as distinct fluids. In the model the continuity, momentum, and energy equations of a two-ion (O(+) and H(+)), quasi-neutral, currentless plasma are solved along a closed geomagnetic field line; diffusive equilibrium is not assumed. collisions between all stream pairs and with neutral species are included. The model includes a corotating, tilted dipole magnetic field and neutral winds. Ionospheric sources and sinks are accounted for in a self-consistent manner. Electrons are assumed to be heated by photoelectrons. The model flux tube extends from a 200-km altitude in one hemisphere to a 200-km altitude in the other hemisphere. Initially, the upwelling streams pass through each other practically unimpeded. When the streams approach the boundary in the conjugate ionosphere, a shock develops there, which moves upward and dissipates slowly; at about the same time a reverse shock develops in the hemisphere of origin, which moves upward. After about 1 hour, large shocks develop in each stream near the equator; these shocks move toward the equator and downward after crossing the equator. However, these shocks are probably artificial, because counterstreaming flows occur in each H(+) fluid, which the model can only handle by creating shocks.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70156109','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70156109"><span>Coral proxy record of decadal-scale reduction in base flow from Moloka'i, Hawaii</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Prouty, Nancy G.; Jupiter, Stacy D.; Field, Michael E.; McCulloch, Malcolm T.</p> <p>2009-01-01</p> <p>Groundwater is a major resource in Hawaii and is the principal source of water for municipal, agricultural, and industrial use. With a growing population, a long-term downward trend in rainfall, and the need for proper groundwater management, a better understanding of the hydroclimatological system is essential. Proxy records from corals can supplement long-term observational networks, offering an accessible source of hydrologic and climate information. To develop a qualitative proxy for historic groundwater discharge to coastal waters, a suite of rare earth elements and yttrium (REYs) were analyzed from coral cores collected along the south shore of Moloka'i, Hawaii. The coral REY to calcium (Ca) ratios were evaluated against hydrological parameters, yielding the strongest relationship to base flow. Dissolution of REYs from labradorite and olivine in the basaltic rock aquifers is likely the primary source of coastal ocean REYs. There was a statistically significant downward trend (−40%) in subannually resolved REY/Ca ratios over the last century. This is consistent with long-term records of stream discharge from Moloka'i, which imply a downward trend in base flow since 1913. A decrease in base flow is observed statewide, consistent with the long-term downward trend in annual rainfall over much of the state. With greater demands on freshwater resources, it is appropriate for withdrawal scenarios to consider long-term trends and short-term climate variability. It is possible that coral paleohydrological records can be used to conduct model-data comparisons in groundwater flow models used to simulate changes in groundwater level and coastal discharge.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=411529','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=411529"><span>Bed load transport by submerged jets</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Francis, J. R. D.; McCreath, P. S.</p> <p>1979-01-01</p> <p>Some similarities are presented between the bed load transport of noncohesive grains in long rivers and at a local, jet-induced scour. Experiments are described in which a submerged two-dimensional slot nozzle, inclined downward, eroded a deep sand bed. The rate of erosion at the very beginning of a scour was evaluated and compared with river data by use of the idea of “stream-power.” Empirical relationships for the two cases are similar, although the geometry of the boundaries is quite different. PMID:16592696</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/wri/1986/4097/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/wri/1986/4097/report.pdf"><span>Reconnaissance of the ground-water, surface-water system in the Zekiah Swamp Run basin, Charles and Prince Georges Counties, Maryland</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hopkins, H.T.; Fisher, G.T.; McGreevy, L.J.</p> <p>1986-01-01</p> <p>The water table in the alluvium of the Zekiah Swamp Run valley in southern Maryland is above stream level during most of the year and the alluvial aquifer contributes water to the stream. During the summer, however, high evapotranspiration sometimes lowers the water table below the stream level. Water then moves from the stream to the alluvium and, at times, reaches of the stream become dry. Pumping from the confined aquifers has caused water levels to decline several tens of ft, which has increased the downward gradient between the water-table aquifer and the underlying confined aquifers. Three synoptic surveys of base flow show areal and temporal variations in stream discharge, pH, specific conductance, dissolved oxygen, and temperature. April 1984 base flows were high (141 cu ft/sec, at the Route 6 gage) because of high precipitation during March. July 1983 base flows were low (2.35 cu ft/sec at the Route 6 gage) and showed significant loss of streamflow because of high antecedent evapotranspiration. Estimates of inflow and outflow of the Zekiah Swamp Run basin above Route 6 during the 1984 water year include: Precipitation, 50.21 in; stream outflow, 20.10 in; shallow groundwater underflow, 0.1 in; stream outflow, 20.10 in; shallow groundwater underflow, 0.1 in; and evapotranspiration, 33 in. A streamflow budget of a 5.1 mi area of the valley of Zekiah Swamp Run between Routes 5 and 6, during the April 1984 survey and a loss of almost 5 cu ft during the July 1983 survey. (Author 's abstract)</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70186327','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70186327"><span>Shallow bedrock limits groundwater seepage-based headwater climate refugia</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Briggs, Martin A.; Lane, John W.; Snyder, Craig D.; White, Eric A.; Johnson, Zachary; Nelms, David L.; Hitt, Nathaniel P.</p> <p>2018-01-01</p> <p>Groundwater/surface-water exchanges in streams are inexorably linked to adjacent aquifer dynamics. As surface-water temperatures continue to increase with climate warming, refugia created by groundwater connectivity is expected to enable cold water fish species to survive. The shallow alluvial aquifers that source groundwater seepage to headwater streams, however, may also be sensitive to seasonal and long-term air temperature dynamics. Depth to bedrock can directly influence shallow aquifer flow and thermal sensitivity, but is typically ill-defined along the stream corridor in steep mountain catchments. We employ rapid, cost-effective passive seismic measurements to evaluate the variable thickness of the shallow colluvial and alluvial aquifer sediments along a headwater stream supporting cold water-dependent brook trout (Salvelinus fontinalis) in Shenandoah National Park, VA, USA. Using a mean depth to bedrock of 2.6 m, numerical models predicted strong sensitivity of shallow aquifer temperature to the downward propagation of surface heat. The annual temperature dynamics (annual signal amplitude attenuation and phase shift) of potential seepage sourced from the shallow modeled aquifer were compared to several years of paired observed stream and air temperature records. Annual stream water temperature patterns were found to lag local air temperature by ∼8–19 d along the stream corridor, indicating that thermal exchange between the stream and shallow groundwater is spatially variable. Locations with greater annual signal phase lag were also associated with locally increased amplitude attenuation, further suggestion of year-round buffering of channel water temperature by groundwater seepage. Numerical models of shallow groundwater temperature that incorporate regional expected climate warming trends indicate that the summer cooling capacity of this groundwater seepage will be reduced over time, and lower-elevation stream sections may no longer serve as larger-scale climate refugia for cold water fish species, even with strong groundwater discharge.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/circ/1350/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/circ/1350/"><span>The quality of our Nation's waters-Nutrients in the Nation's streams and groundwater, 1992-2004</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Dubrovsky, N.M.; Burow, K.R.; Clark, G.M.; Gronberg, J.M.; Hamilton, P.A.; Hitt, K.J.; Mueller, D.K.; Munn, M.D.; Nolan, B.T.; Puckett, L.J.; Rupert, M.G.; Short, T.M.; Spahr, N.E.; Sprague, L.A.; Wilber, W.G.</p> <p>2010-01-01</p> <p>National Findings and Their Implications Although the use of artificial fertilizer has supported increasing food production to meet the needs of a growing population, increases in nutrient loadings from agricultural and, to a lesser extent, urban sources have resulted in nutrient concentrations in many streams and parts of aquifers that exceed standards for protection of human health and (or) aquatic life, often by large margins. Do NAWQA findings substantiate national concerns for aquatic and human health? National Water-Quality Assessment (NAWQA) findings indicate that nutrient concentrations in streams and groundwater in basins with significant agricultural or urban development are substantially greater than naturally occurring or ?background? levels. For example, median concentrations of total nitrogen and phosphorus in agricultural streams are about 6 times greater than background levels. Findings also indicate that concentrations in streams routinely were 2 to 10 times greater than regional nutrient criteria recommended by the U.S. Environmental Protection Agency (USEPA) to protect aquatic life. Such large differences in magnitude suggest that significant reductions in sources of nutrients, as well as greater use of land management strategies to reduce the transport of nutrients to streams, are needed to meet recommended criteria for streams draining areas with significant agricultural and urban development. Nitrate concentrations above the Federal drinking-water standard-or Maximum Contaminant Level (MCL)-of 10 milligrams per liter (mg/L, as nit-ogen) are relatively uncommon in samples from streams used for drinking water or from relatively deep aquifers; the MCL is exceeded, however, in more than 20 percent of shallow (less than 100 feet below the water table) domestic wells in agricultural areas. This finding raises concerns for human health in rural agricultural areas where shallow groundwater is used for domestic supply and may warn of future contamination of deeper groundwater pumped from public-supply wells. Are levels of nutrients in water increasing or decreasing? A decadal assessment of trends in concentrations of nitrogen and phosphorus from about 1993 to 2003 shows minimal changes in those concentrations in the majority of studied streams across the Nation, and more upward than downward trends in concentrations at sites with changes. These findings underscore the need for reductions in nutrient inputs or management strategies that would reduce transport of nutrients to streams. Upward trends were evident among all land uses, including those only minimally affected by agricultural and (or) urban development, which suggests that additional protection of some of our Nation's most pristine streams warrants consideration. The median of nitrate concentrations in groundwater from 495 wells also increased significantly from 3.2 to 3.4 mg/L (6 percent) during about the same period, and the proportion of wells with concentrations of nitrate greater than the MCL increased from 16 to 21 percent. Nitrate concentrations in water in deep aquifers are likely to increase during the next decade as shallow groundwater with elevated concentrations moves downward. The potential for future contamination of the deep aquifers requires attention because these aquifers commonly are used for public water supply, and because restoration of groundwater is costly and difficult. Long-term and consistent monitoring of nutrients, improved accounting of nutrient sources, and improved tracking and modeling of climatic and landscape changes will be essential for distinguishing trends in nutrient concentrations, understanding the causes of those trends, and accurately tracking the effectiveness of strategies implemented to manage nutrients.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/circ/1350/pdf/circ1350.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/circ/1350/pdf/circ1350.pdf"><span>The quality of our Nation's waters-Nutrients in the Nation's streams and groundwater, 1992-2004</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Dubrovsky, Neil M.; Burow, Karen R.; Clark, Gregory M.; Gronberg, JoAnn M.; Hamilton, Pixie A.; Hitt, Kerie J.; Mueller, David K.; Munn, Mark D.; Nolan, Bernard T.; Puckett, Larry J.; Rupert, Michael G.; Short, Terry M.; Spahr, Norman E.; Sprague, Lori A.; Wilber, William G.</p> <p>2010-01-01</p> <p>National Findings and Their ImplicationsAlthough the use of artificial fertilizer has supported increasing food production to meet the needs of a growing population, increases in nutrient loadings from agricultural and, to a lesser extent, urban sources have resulted in nutrient concentrations in many streams and parts of aquifers that exceed standards for protection of human health and (or) aquatic life, often by large margins.Do NAWQA findings substantiate national concerns for aquatic and human health?National Water-Quality Assessment (NAWQA) findings indicate that nutrient concentrations in streams and groundwater in basins with significant agricultural or urban development are substantially greater than naturally occurring or “background” levels. For example, median concentrations of total nitrogen and phosphorus in agricultural streams are about 6 times greater than background levels. Findings also indicate that concentrations in streams routinely were 2 to 10 times greater than regional nutrient criteria recommended by the U.S. Environmental Protection Agency (USEPA) to protect aquatic life. Such large differences in magnitude suggest that significant reductions in sources of nutrients, as well as greater use of land management strategies to reduce the transport of nutrients to streams, are needed to meet recommended criteria for streams draining areas with significant agricultural and urban development.Nitrate concentrations above the Federal drinking-water standard—or Maximum Contaminant Level (MCL)—of 10 milligrams per liter (mg/L, as nitrogen) are relatively uncommon in samples from streams used for drinking water or from relatively deep aquifers; the MCL is exceeded, however, in more than 20 percent of shallow (less than 100 feet below the water table) domestic wells in agricultural areas. This finding raises concerns for human health in rural agricultural areas where shallow groundwater is used for domestic supply and may warn of future contamination of deeper groundwater pumped from public‑supply wells.Are levels of nutrients in water increasing or decreasing?A decadal assessment of trends in concentrations of nitrogen and phosphorus from about 1993 to 2003 shows minimal changes in those concentrations in the majority of studied streams across the Nation, and more upward than downward trends in concentrations at sites with changes. These findings underscore the need for reductions in nutrient inputs or management strategies that would reduce transport of nutrients to streams. Upward trends were evident among all land uses, including those only minimally affected by agricultural and (or) urban development, which suggests that additional protection of some of our Nation’s most pristine streams warrants consideration.The median of nitrate concentrations in groundwater from 495 wells also increased significantly from 3.2 to 3.4 mg/L (6 percent) during about the same period, and the proportion of wells with concentrations of nitrate greater than the MCL increased from 16 to 21 percent. Nitrate concentrations in water in deep aquifers are likely to increase during the next decade as shallow groundwater with elevated concentrations moves downward. The potential for future contamination of the deep aquifers requires attention because these aquifers commonly are used for public water supply, and because restoration of groundwater is costly and difficult.Long-term and consistent monitoring of nutrients, improved accounting of nutrient sources, and improved tracking and modeling of climatic and landscape changes will be essential for distinguishing trends in nutrient concentrations, understanding the causes of those trends, and accurately tracking the effectiveness of strategies implemented to manage nutrients.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.H21N..04K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.H21N..04K"><span>The Regulation of a Spatially Heterogeneous Externality: Tradable Groundwater Permits to Protect Streams</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kuwayama, Y.; Brozovic, N.</p> <p>2012-12-01</p> <p>Groundwater pumping from aquifers can reduce the flow of surface water in nearby streams through a process known as stream depletion. In the United States, recent awareness of this externality has led to intra- and inter-state conflict and rapidly-changing water management policies and institutions. A factor that complicates the design of groundwater management policies to protect streams is the spatial heterogeneity of the stream depletion externality; the marginal damage of groundwater use on stream flows depends crucially on the location of pumping relative to streams. Under these circumstances, economic theory predicts that spatially differentiated policies can achieve an aggregate reduction in stream depletion cost effectively. However, whether spatially differentiated policies offer significant abatement cost savings and environmental improvements over simpler, alternative policies is an empirical question. In this paper, we analyze whether adopting a spatially differentiated groundwater permit system can lead to significant savings in compliance costs while meeting targets on stream protection. Using a population data set of active groundwater wells in the Nebraska portion of the Republican River Basin, we implement an optimization model of each well owner's crop choice, land use, and irrigation decisions to determine the distribution of regulatory costs. We model the externality of pumping on streams by employing an analytical solution from the hydrology literature that determines reductions in stream flow caused by groundwater pumping over space and time. The economic and hydrologic model components are then combined into one optimization framework, which allows us to measure farmer abatement costs and stream flow benefits under a constrained optimal market that features spatially differentiated, tradable groundwater permits. We compare this outcome to the efficiency of alternative second-best policies, including spatially uniform permit markets and pumping restrictions based on geographic zones. Our analysis considers static policies for which abatement is fixed over time, as well as dynamic policies that allow abatement to vary over time and future compliance costs to be subject to a discount rate. We find that if current levels of stream flow in the Republican River Basin are held fixed, regulators can generate most of the potential abatement cost savings by establishing a one-to-one tradable permit system that does not account for spatial heterogeneity. We obtain this surprising result because the agronomic and climatic parameters in our data set that determine farmer abatement costs are spatially correlated with hydrologic parameters that determine the marginal damage of groundwater use on streams. However, we also find that if future legal or ecological circumstances require regulators to increase significantly the protection of streams from current levels, spatially differentiated policies will generate sizable cost savings compared to policies that ignore spatial heterogeneity.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25111547','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25111547"><span>Ethnicity moderates the outcomes of self-enhancement and self-improvement themes in expressive writing.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tsai, William; Lau, Anna S; Niles, Andrea N; Coello, Jordan; Lieberman, Matthew D; Ko, Ahra C; Hur, Christopher; Stanton, Annette L</p> <p>2015-10-01</p> <p>The current study examined whether writing content related to self-enhancing (viz., downward social comparison and situational attributions) and self-improving (viz., upward social comparison and persistence) motivations were differentially related to expressive writing outcomes among 17 Asian American and 17 European American participants. Content analysis of the essays revealed no significant cultural group differences in the likelihood of engaging in self-enhancing versus self-improving reflections on negative personal experiences. However, cultural group differences were apparent in the relation between self-motivation processes and changes in anxiety and depressive symptoms at 3-month follow-up. Among European Americans, writing that reflected downward social comparison predicted positive outcomes, whereas persistence writing themes were related to poorer outcomes. For Asian Americans, writing about persistence was related to positive outcomes, whereas downward social comparison and situational attributions predicted poorer outcomes. Findings provide evidence suggesting culturally distinct mechanisms for the effects of expressive disclosure. (PsycINFO Database Record (c) 2015 APA, all rights reserved).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/wri/1994/4227/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/wri/1994/4227/report.pdf"><span>Water-quality assessment of the Kentucky River basin, Kentucky; nutrients, sediments, and pesticides in streams, 1987-90</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Haag, K.H.; Porter, S.D.</p> <p>1995-01-01</p> <p>The U.S. Geological Survey investigated the water quality of the Kentucky River Basin in Kentucky as part of the National Water Quality Assessment program. Data collected during 1987-90 were used to describe the spatial and temporal variability of nutrients, suspended sediment, and pesticides in streams. Concentrations of phosphorus were signifi- cantly correlated with urban and agricultural land use. The high phosphorus content of Bluegrass Region soils was an important source of phosphorus in streams. At many sites in urban areas, all of the stream nitrogen load was attributable to wastewater- treatment-plant effluent. Tributary streams affected by agricultural sources of nutrients contained higher densities of phytoplankton than streams that drained forested areas. Data indicate that a consid- erable percentage of total nitrogen was transported as algal biomass during periods of low discharge. Average suspended-sediment concentrations for the study period were positively correlated with dis- charge. There was a downward trend in suspended- sediment concentrations downstream in the Kentucky River main stem during the study. Although a large amount of suspended sediment originates in the Eastern Coal Field Region, contributions of suspended sediment from the Red River and other tributary streams of the Knobs Region also are important. The most frequently detected herbicides in water samples were atrazine, 2,4-D, alachlor, metolachlor, and dicamba. Diazinon, malathion, and parathion were the most frequently detected organo- phosphate insecticides in water samples. Detectable concentrations of aldrin, chlordane, DDT, DDE, dieldrin, endrin, endosulfan, heptachlor, heptachlor epoxide, and lindane were found in streambed- sediment samples.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.sciencedirect.com/science/article/pii/S0022169414007124','USGSPUBS'); return false;" href="http://www.sciencedirect.com/science/article/pii/S0022169414007124"><span>Practical limitations on the use of diurnal temperature signals to quantify groundwater upwelling</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Briggs, Martin A.; Lautz, Laura K.; Buckley, Sean F.; Lane, John W.</p> <p>2014-01-01</p> <p>Groundwater upwelling to streams creates unique habitat by influencing stream water quality and temperature; upwelling zones also serve as vectors for contamination when groundwater is degraded. Temperature time series data acquired along vertical profiles in the streambed have been applied to simple analytical models to determine rates of vertical fluid flux. These models are based on the downward propagation characteristics (amplitude attenuation and phase-lag) of the surface diurnal signal. Despite the popularity of these models, there are few published characterizations of moderate-to-strong upwelling. We attribute this limitation to the thermodynamics of upwelling, under which the downward conductive signal transport from the streambed interface occurs opposite the upward advective fluid flux. Governing equations describing the advection–diffusion of heat within the streambed predict that under upwelling conditions, signal amplitude attenuation will increase, but, counterintuitively, phase-lag will decrease. Therefore the extinction (measurable) depth of the diurnal signal is very shallow, but phase lag is also short, yielding low signal to noise ratio and poor model sensitivity. Conversely, amplitude attenuation over similar sensor spacing is strong, yielding greater potential model sensitivity. Here we present streambed thermal time series over a range of moderate to strong upwelling sites in the Quashnet River, Cape Cod, Massachusetts. The predicted inverse relationship between phase-lag and rate of upwelling was observed in the field data over a range of conditions, but the observed phase-lags were consistently shorter than predicted. Analytical solutions for fluid flux based on signal amplitude attenuation return results consistent with numerical models and physical seepage meters, but the phase-lag analytical model results are generally unreasonable. Through numerical modeling we explore reasons why phase-lag may have been over-predicted by the analytical models, and develop guiding relations of diurnal temperature signal extinction depth based on stream diurnal signal amplitude, upwelling magnitude, and streambed thermal properties that will be useful in designing future experiments.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.loc.gov/pictures/collection/hh/item/ca2942.photos.382354p/','SCIGOV-HHH'); return false;" href="https://www.loc.gov/pictures/collection/hh/item/ca2942.photos.382354p/"><span>Credit BG. Interior view of Building 4316, showing internal construction ...</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>Credit BG. Interior view of Building 4316, showing internal construction of water reservoir, roof, and monitor. View looks southeast (142°). The pipe which hangs from the roof structure and turns downward under the monitor supplies water to the reservoir; the plate suspended on chains beneath the pipe end deflects water stream so it does not erode the bottom of the reservoir. The intake pipe for the pumps is not visible in this view - Edwards Air Force Base, North Base, Deluge Water Storage Building, Near Second & D Streets, Boron, Kern County, CA</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/865772','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/865772"><span>Thermophoretic separation of aerosol particles from a sampled gas stream</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Postma, Arlin K.</p> <p>1986-01-01</p> <p>A method for separating gaseous samples from a contained atmosphere that includes aerosol particles uses the step of repelling particles from a gas permeable surface or membrane by heating the surface to a temperature greater than that of the surrounding atmosphere. The resulting thermophoretic forces maintain the gas permeable surface clear of aerosol particles. The disclosed apparatus utilizes a downwardly facing heated plate of gas permeable material to combine thermophoretic repulsion and gravity forces to prevent particles of any size from contacting the separating plate surfaces.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016cosp...41E1704S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016cosp...41E1704S"><span>Geoeffectiveness of Stream Interaction Regions during 2007-2008</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sanchez-Garcia, Elsa; Aguilar-Rodriguez, Ernesto; Ontiveros, Veronica</p> <p>2016-07-01</p> <p>The Stream Interaction Regions (SIRs) are generated in the interplanetary medium when a fast solar wind stream overtakes a slower one. If these large-scale phenomena interact with the Earth's magnetosphere they can give rise to geomagnetic storms (GSs). In this study we analyze the degree of geoeffectiveness of 20 events that were generated by SIRs. The events were observed during the 2007-2008 period that comprising the extended downward phase of solar cycle 23. The degree of geoeffectivity is measured using magnetic indices from different latitudes: PCN (Polar cap north), PCS (polar cap south), AA (antipodal amplitude), AE (Auroral Electrojet), Kp (estimated global index) and Dst (Disturbance storm time). We discuss some results on the correlation of these magnetic indices with the characteristics of shocks associated with the SIRs observed by STEREO-A/B, WIND and ACE spacecraft. All the 20 SIRs events generated GSs with Dst values in ranging from -86 nT up to -12 nT. Moreover, 6 out of the 20 events presented storm sudden commencement (SSC). We also discuss on the characteristics of the SIR-associated shocks and the intensity of the GSs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19730031394&hterms=Computer+Definition&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DComputer%2BDefinition','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19730031394&hterms=Computer+Definition&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DComputer%2BDefinition"><span>Implications of a quadratic stream definition in radiative transfer theory.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Whitney, C.</p> <p>1972-01-01</p> <p>An explicit definition of the radiation-stream concept is stated and applied to approximate the integro-differential equation of radiative transfer with a set of twelve coupled differential equations. Computational efficiency is enhanced by distributing the corresponding streams in three-dimensional space in a totally symmetric way. Polarization is then incorporated in this model. A computer program based on the model is briefly compared with a Monte Carlo program for simulation of horizon scans of the earth's atmosphere. It is found to be considerably faster.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002ASAJ..112..441M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002ASAJ..112..441M"><span>Acoustic streaming related to minor loss phenomenon in differentially heated elements of thermoacoustic devices</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mironov, Mikhail; Gusev, Vitalyi; Auregan, Yves; Lotton, Pierrick; Bruneau, Michel; Piatakov, Pavel</p> <p>2002-08-01</p> <p>It is demonstrated that the differentially heated stack, the heart of all thermoacoustic devices, provides a source of streaming additional to those associated with Reynolds stresses in quasi-unidirectional gas flow. This source of streaming is related to temperature-induced asymmetry in the generation of vortices and turbulence near the stack ends. The asymmetry of the hydrodynamic effects in an otherwise geometrically symmetric stack is due to the temperature difference between stack ends. The proposed mechanism of streaming excitation in annular thermoacoustic devices operates even in the absence of thermo-viscous interaction of sound waves with resonator walls. copyright 2002 Acoustical Society of America.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=241495&keyword=drought&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=241495&keyword=drought&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>Are macroinvertebrate functional traits useful in differentiating hydrologically variable small piedmont streams and their recovery from drought?</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>We quantified benthic macroinvertebrates in six small (1st order) Alabama piedmont streams from 1994-1998. Streams spanned a gradient of hydrologic permanence from typically intermittent to perennial, the degree of permanence for a given stream depending on water year. Initial sa...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1917470P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1917470P"><span>Is tropospheric weather influenced by solar wind through atmospheric vertical coupling downward control?</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Prikryl, Paul; Tsukijihara, Takumi; Iwao, Koki; Muldrew, Donald B.; Bruntz, Robert; Rušin, Vojto; Rybanský, Milan; Turňa, Maroš; Šťastný, Pavel; Pastirčák, Vladimír</p> <p>2017-04-01</p> <p>More than four decades have passed since a link between solar wind magnetic sector boundary structure and mid-latitude upper tropospheric vorticity was discovered (Wilcox et al., Science, 180, 185-186, 1973). The link has been later confirmed and various physical mechanisms proposed but apart from controversy, little attention has been drawn to these results. To further emphasize their importance we investigate the occurrence of mid-latitude severe weather in the context of solar wind coupling to the magnetosphere-ionosphere-atmosphere (MIA) system. It is observed that significant snowstorms, windstorms and heavy rain, particularly if caused by low pressure systems in winter, tend to follow arrivals of high-speed solar wind. Previously published statistical evidence that explosive extratropical cyclones in the northern hemisphere tend to occur after arrivals of high-speed solar wind streams from coronal holes (Prikryl et al., Ann. Geophys., 27, 1-30, 2009; Prikryl et al., J. Atmos. Sol.-Terr. Phys., 149, 219-231, 2016) is corroborated for the southern hemisphere. A physical mechanism to explain these observations is proposed. The leading edge of high-speed solar wind streams is a locus of large-amplitude magneto-hydrodynamic waves that modulate Joule heating and/or Lorentz forcing of the high-latitude lower thermosphere generating medium-scale atmospheric gravity waves that propagate upward and downward through the atmosphere. Simulations of gravity wave propagation in a model atmosphere using the Transfer Function Model (Mayr et al., Space Sci. Rev., 54, 297-375, 1990) show that propagating waves originating in the thermosphere can excite a spectrum of gravity waves in the lower atmosphere. In spite of significantly reduced amplitudes but subject to amplification upon reflection in the upper troposphere, these gravity waves can provide a lift of unstable air to release instabilities in the troposphere thus initiating convection to form cloud/precipitation bands (Prikryl et al., Ann. Geophys., 27, 31-57, 2009). It is primarily the energy provided by release of latent heat that leads to intensification of storms. These results indicate that vertical coupling in the atmosphere exerts downward control from solar wind to the lower atmospheric levels influencing tropospheric weather development.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2011-12-23/pdf/2011-32728.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2011-12-23/pdf/2011-32728.pdf"><span>76 FR 80249 - Use of Differential Income Stream as a Consideration in Assessing the Best Method</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2011-12-23</p> <p>... Differential Income Stream as a Consideration in Assessing the Best Method AGENCY: Internal Revenue Service... method in connection with a cost sharing arrangement. The text of these temporary regulations also serves... unreasonable positions in applying the income method by using relatively low licensing discount rates, and...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active"><span>4</span></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_4 --> <div id="page_5" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="81"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70033791','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70033791"><span>Trends in pesticide concentrations in streams of the western United States, 1993-2005</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Johnson, H.M.; Domagalski, Joseph L.; Saleh, D.K.</p> <p>2011-01-01</p> <p>Trends in pesticide concentrations for 15 streams in California, Oregon, Washington, and Idaho were determined for the organophosphate insecticides chlorpyrifos and diazinon and the herbicides atrazine, s-ethyl diproplythiocarbamate (EPTC), metolachlor, simazine, and trifluralin. A parametric regression model was used to account for flow, seasonality, and antecedent hydrologic conditions and thereby estimate trends in pesticide concentrations in streams arising from changes in use amount and application method in their associated catchments. Decreasing trends most often were observed for diazinon, and reflect the shift to alternative pesticides by farmers, commercial applicators, and homeowners because of use restrictions and product cancelation. Consistent trends were observed for several herbicides, including upward trends in simazine at urban-influenced sites from 2000 to 2005, and downward trends in atrazine and EPTC at agricultural sites from the mid-1990s to 2005. The model provided additional information about pesticide occurrence and transport in the modeled streams. Two examples are presented and briefly discussed: (1) timing of peak concentrations for individual compounds varied greatly across this geographic gradient because of different application periods and the effects of local rain patterns, irrigation, and soil drainage and (2) reconstructions of continuous diazinon concentrations at sites in California are used to evaluate compliance with total maximum daily load targets.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1131018','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1131018"><span>Mass independent kinetic energy reducing inlet system for vacuum environment</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Reilly, Peter T.A.</p> <p>2014-05-13</p> <p>A particle inlet system comprises a first chamber having a limiting orifice for an incoming gas stream and a micrometer controlled expansion slit. Lateral components of the momentum of the particles are substantially cancelled due to symmetry of the configuration once the laminar flow converges at the expansion slit. The particles and flow into a second chamber, which is maintained at a lower pressure than the first chamber, and then moves into a third chamber including multipole guides for electromagnetically confining the particle. The vertical momentum of the particles descending through the center of the third chamber is minimized as an upward stream of gases reduces the downward momentum of the particles. The translational kinetic energy of the particles is near-zero irrespective of the mass of the particles at an exit opening of the third chamber, which may be advantageously employed to provide enhanced mass resolution in mass spectrometry.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1009817','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1009817"><span>Mass independent kinetic energy reducing inlet system for vacuum environment</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Reilly, Peter T. A. [Knoxville, TN</p> <p>2010-12-14</p> <p>A particle inlet system comprises a first chamber having a limiting orifice for an incoming gas stream and a micrometer controlled expansion slit. Lateral components of the momentum of the particles are substantially cancelled due to symmetry of the configuration once the laminar flow converges at the expansion slit. The particles and flow into a second chamber, which is maintained at a lower pressure than the first chamber, and then moves into a third chamber including multipole guides for electromagnetically confining the particle. The vertical momentum of the particles descending through the center of the third chamber is minimized as an upward stream of gases reduces the downward momentum of the particles. The translational kinetic energy of the particles is near-zero irrespective of the mass of the particles at an exit opening of the third chamber, which may be advantageously employed to provide enhanced mass resolution in mass spectrometry.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1109353','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1109353"><span>Mass independent kinetic energy reducing inlet system for vacuum environment</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Reilly, Peter T.A.</p> <p>2013-12-03</p> <p>A particle inlet system comprises a first chamber having a limiting orifice for an incoming gas stream and a micrometer controlled expansion slit. Lateral components of the momentum of the particles are substantially cancelled due to symmetry of the configuration once the laminar flow converges at the expansion slit. The particles and flow into a second chamber, which is maintained at a lower pressure than the first chamber, and then moves into a third chamber including multipole guides for electromagnetically confining the particle. The vertical momentum of the particles descending through the center of the third chamber is minimized as an upward stream of gases reduces the downward momentum of the particles. The translational kinetic energy of the particles is near-zero irrespective of the mass of the particles at an exit opening of the third chamber, which may be advantageously employed to provide enhanced mass resolution in mass spectrometry.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20100033375&hterms=scandinavia&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dscandinavia','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20100033375&hterms=scandinavia&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dscandinavia"><span>Mountain Waves in the Middle Atmosphere: Microwave Limb Sounder Observations and Analyses</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jiang, Jonathan H.; Wu, Dong L.; Eckermann, Stephen D.; Ma, Jun</p> <p>2003-01-01</p> <p>Observations and analyses of mesoscale gravity waves in the stratosphere from the Upper Atmosphere Research Satellite (UARS) Microwave Limb Sounder (MLS) are summarized, with focus on global distribution of topography related wave activities. We found most of the orographical wave activities occur during the winter seasons over high latitude mountain ridges. In the northern hemisphere, the strongest waves are those over Scandinavia, Central Eurasia, and southern Greenland, whereas in the southern hemisphere, wave activities are outstanding over the Andes, New Zealand, and Antarctic rim;, MLS observations suggest that these orographic waves are located mostly on the down stream side of the mountain ridge with downward phase progression and have horizontal phase velocities opposite to the stratospheric jet-stream. Future studies using MLS data and numerical modeling will lead to better understanding of gravity wave effects on dynamics and chemistry in the middle atmosphere.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2017/5147/sir20175147.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2017/5147/sir20175147.pdf"><span>Temporal trends in water-quality constituent concentrations and annual loads of chemical constituents in Michigan watersheds, 1998–2013</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hoard, Christopher J.; Fogarty, Lisa R.; Duris, Joseph W.</p> <p>2018-02-21</p> <p>In 1998, the Michigan Department of Environmental Quality and the U.S. Geological Survey began the Water Chemistry Monitoring Program for select streams in the State of Michigan. Objectives of this program were to provide assistance with (1) statewide water-quality assessments, (2) the National Pollutant Discharge Elimination System permitting process, and (3) water-resource management decisions. As part of this program, water-quality data collected from 1998 to 2013 were analyzed to identify potential trends for select constituents that were sampled. Sixteen water-quality constituents were analyzed at 32 stations throughout Michigan. Trend analysis on the various water-quality data was done using either the uncensored Seasonal Kendall test or through Tobit regression. In total, 79 trends were detected in the constituents analyzed for 32 river stations sampled for the study period—53 downward trends and 26 upward trends were detected. The most prevalent trend detected throughout the State was for ammonia, with 11 downward trends and 1 upward trend estimated.In addition to trends, constituent loads were estimated for 31 stations from 2002 to 2013 for stations that were sampled 12 times per year. Loads were computed using the Autobeale load computation program, which used the Beale ratio estimator approach to estimate an annual load. Constituent loads were the largest in large watershed streams with the highest annual flows such as the Saginaw and Grand Rivers. Likewise, constituent loads were the smallest in smaller tributaries that were sampled as part of this program such as the Boardman and Thunder Bay Rivers.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2013-10-22/pdf/2013-24537.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2013-10-22/pdf/2013-24537.pdf"><span>78 FR 62426 - Use of Differential Income Stream as an Application of the Income Method and as a Consideration...</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2013-10-22</p> <p>... Differential Income Stream as an Application of the Income Method and as a Consideration in Assessing the Best Method; Correction AGENCY: Internal Revenue Service (IRS), Treasury. ACTION: Correcting amendment... method in connection with a cost sharing arrangement and as a specified application of the income method...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1054709','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1054709"><span>Detailed Hydrographic Feature Extraction from High-Resolution LiDAR Data</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Danny L. Anderson</p> <p></p> <p>Detailed hydrographic feature extraction from high-resolution light detection and ranging (LiDAR) data is investigated. Methods for quantitatively evaluating and comparing such extractions are presented, including the use of sinuosity and longitudinal root-mean-square-error (LRMSE). These metrics are then used to quantitatively compare stream networks in two studies. The first study examines the effect of raster cell size on watershed boundaries and stream networks delineated from LiDAR-derived digital elevation models (DEMs). The study confirmed that, with the greatly increased resolution of LiDAR data, smaller cell sizes generally yielded better stream network delineations, based on sinuosity and LRMSE. The second study demonstrates amore » new method of delineating a stream directly from LiDAR point clouds, without the intermediate step of deriving a DEM. Direct use of LiDAR point clouds could improve efficiency and accuracy of hydrographic feature extractions. The direct delineation method developed herein and termed “mDn”, is an extension of the D8 method that has been used for several decades with gridded raster data. The method divides the region around a starting point into sectors, using the LiDAR data points within each sector to determine an average slope, and selecting the sector with the greatest downward slope to determine the direction of flow. An mDn delineation was compared with a traditional grid-based delineation, using TauDEM, and other readily available, common stream data sets. Although, the TauDEM delineation yielded a sinuosity that more closely matches the reference, the mDn delineation yielded a sinuosity that was higher than either the TauDEM method or the existing published stream delineations. Furthermore, stream delineation using the mDn method yielded the smallest LRMSE.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://eric.ed.gov/?q=cp+AND+sex&pg=7&id=EJ189653','ERIC'); return false;" href="https://eric.ed.gov/?q=cp+AND+sex&pg=7&id=EJ189653"><span>Teacher Survival Rates--A Current Look</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Mark, Jonathan H.; Anderson, Barry D.</p> <p>1978-01-01</p> <p>To examine how survival rates change with time, each cohort of new entrants to the public school teaching profession between 1968 and 1976 was examined. Results replicated Charters' downward sloping survival curve, although the curve has shifted up steadily through time. The survival rate differential between men and women is decreasing over time.…</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10923714','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10923714"><span>The pattern of acropetal and basipetal cytoplasmic streaming velocities in Chara rhizoids and protonemata, and gravity effect on the pattern as measured by laser-Doppler-velocimetry.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ackers, D; Buchen, B; Hejnowicz, Z; Sievers, A</p> <p>2000-06-01</p> <p>The spatial pattern of acropetal and basipetal cytoplasmic streaming velocities has been studied by laser-Doppler-velocimetry (LDV) in the positively gravitropic (downward growing) rhizoids of Chara globularis Thuill. and for the first time in the negatively gravitropic (upward growing) protonemata. The LDV method proved to be precise and yielded reproducible results even when tiny differences in velocities were measured. In the apical parts of the streaming regions of both cell types, acropetal streaming was faster than basipetal streaming. Starting at the apical reversal point of streaming, the velocity increased basipetally with the distance from that point and became fairly constant close to the basal reversal point; subsequently, the velocity decreased slightly acropetally as the apical reversal point was again approached. There was no change in velocity at the basal reversal point. However, at the apical reversal point there was an abrupt decrease in velocity. The pattern of the ratio of acropetal to basipetal streaming velocity (VR) was a function of the relative distance of the site of measurement from the apical reversal point rather than a function of the absolute distance. Upon inversion of the rhizoids, the VR decreased on average by 3.8% (+/- 0.4%), indicating that the effect of gravity on the streaming velocity was merely physical and without a physiological amplification. Rhizoids that had developed on the slowly rotating horizontal axis of a clinostat, and had never experienced a constant gravity vector, were similar to normally grown rhizoids with respect to VR pattern. In protonemata, the VR pattern was not significantly different from that in rhizoids although the direction of growth was inverse. In rhizoids, oryzalin caused the polar organization of the cell to disappear and nullified the differences in streaming velocities, and cytochalasin D decreased the velocity of basipetal streaming slightly more than that of acropetal streaming. Cyclopiazonic acid, known as an inhibitor of the Ca2+-ATPase of the endoplasmic reticulum, also reduced the streaming velocities in rhizoids, but had slightly more effect on the acropetal stream. It is possible that the endogenous difference in streaming velocities in both rhizoids and protonemata is caused by differences in the cytoskeletal organization of the opposing streams and/or loading of inhibitors (like Ca2+) from the apical/subapical zone into the basipetally streaming endoplasm.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..1410242G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..1410242G"><span>On the dynamics of stream piracy</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Goren, L.; Willett, S. D.</p> <p>2012-04-01</p> <p>Drainage network reorganization by stream piracy is invoked repeatedly to explain the morphology of unique drainage patterns and as a possible mechanism inducing abrupt variations of sediment accumulation rates. However, direct evidence of stream piracy is usually rare, and is highly interpretation dependent. As a first step in assessing how probable capture events are and establishing the conditions that favor stream piracy versus the those that favor stable landscapes, we formulate analytically the physics of divide migration and capture events and study this formulation from a dynamical system point of view. The formulation is based on a one-dimensional topographic cross section between two channels that share a water divide. Two hillslope profiles diverge from the divide and drain into two fluvial bedrock tributaries, whose erosion rate is controlled by a stream power law. The rate of erosion at the bounding channels is thus a function of the upstream drainage area and local slope. A tectonically induced downward perturbation of the elevation of one of the bounding channels lowers the channel slope but at the same time increases the drainage area due to outward migration of the water divide. The changes in slope and area have opposing effect on the erosion rate at the bounding channels, so that the perturbation may either grow or be damped. We define the geomorphic and tectonic parameters that control the behavior of the system and find the regimes that lead to stable landscapes and to capture events.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20176828','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20176828"><span>Effects of surface and groundwater interactions on phosphorus transport within streambank sediments.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Thompson, Carol A; McFarland, Anne M S</p> <p>2010-01-01</p> <p>Understanding internal stream P transfers is important in controlling eutrophication. To determine the direction of groundwater and surface water interactions and evaluate P retention within streambank sediments, groundwater well pairs, about 5-m deep, were installed at three locations along a second-order, eutrophic stream in north-central Texas. Well cores were analyzed for P, and groundwater levels were monitored for about 2 yr. Water levels in wells furthest upstream always indicated a losing stream, while wells further downstream showed a gaining stream except during flow reversals with storm events and periods with reservoir backwater. Total-P from well cores ranged from 54 to 254 mg kg(-1) and was typically high near surface, decreased downward until redoximorphic features were encountered and then increased notably with depth to near or above surface concentrations. Very little extractable P occurred in sediments from the two upstream well sets; however, the set furthest downstream showed extractable P throughout with a high of 21 mg kg(-1) near the bottom. Repeated wetting-drying at sites A and B as noted by redoximorphic features may have shifted P into more stable sediment-bound forms. The decrease in extractable P at sites A and B compared to site C may be explained by conditions at C that were wetter and potentially anaerobic. Because the overall stream reach was more often losing than gaining, there appears to be a mass flow of P into streambank sediments. Streambank erosion may then transport this P downstream if not controlled.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/2825','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/2825"><span>A Four-Level Hierarchy for Organizing Wildland Stream Resource Information</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Harry Parrott; Daniel A. Marion; R. Douglas Perkinson</p> <p>1989-01-01</p> <p>An analysis of current USDA Forest Service methods of collecting and using wildland stream resource data indicates that required information can be organized into a four-level hierarchy. Information at each level is tiered with information at the preceding level. Level 1 is the ASSOCIATION, which is differentiated by stream size and flow regime. Level 2, STREAM TYPE,...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=53568&Lab=NCEA&keyword=information&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=53568&Lab=NCEA&keyword=information&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>Development of a Methodology to Guide the Replacement of Agency Default Uncertainty Factors with Those Based on Data</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The Agency's guidance for the derivation of RfD and RfC values call for the downward adjustment of exposure-response levels observed in animals and/or humans to account for the potentially greater sensitivity of humans as compared to test animals (UFA) and the differential sensit...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70184994','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70184994"><span>Temporal and spatial trends in nutrient and sediment loading to Lake Tahoe, California-Nevada, USA</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Coats, Robert; Lewis, Jack; Alvarez, Nancy L.; Arneson, Patricia</p> <p>2016-01-01</p> <p>Since 1980, the Lake Tahoe Interagency Monitoring Program (LTIMP) has provided stream-discharge and water quality data—nitrogen (N), phosphorus (P), and suspended sediment—at more than 20 stations in Lake Tahoe Basin streams. To characterize the temporal and spatial patterns in nutrient and sediment loading to the lake, and improve the usefulness of the program and the existing database, we have (1) identified and corrected for sources of bias in the water quality database; (2) generated synthetic datasets for sediments and nutrients, and resampled to compare the accuracy and precision of different load calculation models; (3) using the best models, recalculated total annual loads over the period of record; (4) regressed total loads against total annual and annual maximum daily discharge, and tested for time trends in the residuals; (5) compared loads for different forms of N and P; and (6) tested constituent loads against land use-land cover (LULC) variables using multiple regression. The results show (1) N and P loads are dominated by organic N and particulate P; (2) there are significant long-term downward trends in some constituent loads of some streams; and (3) anthropogenic impervious surface is the most important LULC variable influencing water quality in basin streams. Many of our recommendations for changes in water quality monitoring and load calculation methods have been adopted by the LTIMP.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17877714','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17877714"><span>Tracing the first step to speciation: ecological and genetic differentiation of a salamander population in a small forest.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Steinfartz, Sebastian; Weitere, Markus; Tautz, Diethard</p> <p>2007-11-01</p> <p>Mechanisms and processes of ecologically driven adaptive speciation are best studied in natural situations where the splitting process is still occurring, i.e. before complete reproductive isolation is achieved. Here, we present a case of an early stage of adaptive differentiation under sympatric conditions in the fire salamander, Salamandra salamandra, that allows inferring the underlying processes for the split. Larvae of S. salamandra normally mature in small streams until metamorphosis, but in an old, continuous forest area near Bonn (the Kottenforst), we found salamander larvae not only in small streams but also in shallow ponds, which are ecologically very different from small streams. Common-environment experiments with larvae from both habitat types reveal specific adaptations to these different ecological conditions. Mitochondrial and microsatellite analyses show that the two ecologically differentiated groups also show signs of genetic differentiation. A parallel analysis of animals from a neighbouring much larger forest area (the Eifel), in which larvae mature only in streams, shows no signs of genetic differentiation, indicating that gene flow between ecologically similar types can occur over large distances. Hence, geographical factors cannot explain the differential larval habitat adaptations in the Kottenforst, in particular since adult life and mating of S. salamandra is strictly terrestrial and not associated with larval habitats. We propose therefore that the evolution of these adaptations was coupled with the evolution of cues for assortative mating which would be in line with models of sympatric speciation that suggest a co-evolution of habitat adaptations and associated mating signals.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70020761','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70020761"><span>Factors controlling mercury transport in an upland forested catchment</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Scherbatskoy, T.; Shanley, J.B.; Keeler, G.J.</p> <p>1998-01-01</p> <p>Total mercury (Hg) deposition and input/output relationships were investigated in an 11-ha deciduous forested catchment in northern Vermont as part of ongoing evaluations of rig cycling and transport in the Lake Champlain basin. Atmospheric Hg deposition (precipitation + modeled vapor phase downward flux) was 425 mg ha-1 during the one-year period March 1994 through February 1995 and 463 mg ha-1 from March 1995 through February 1996. In the same periods, stream export of total Hg was 32 mg ha-1 and 22 mg ha-1, respectively. Thus, there was a net retention of Hg by the catchment of 92% the first year and 95% the second year. In the first year, 16.9 mg ha-1 or about half of the annual stream export, occurred on the single day of peak spring snowmelt in April. In contrast, the maximum daily export in the second year, when peak stream flow was somewhat lower, was 3.5 mg ha-1 during a January thaw. The fate of file Hg retained by this forested catchment is not known. Dissolved (< 0.22 ??m) Hg concentrations in stream water ranged from 0.5-2.6 ng L-1, even when total (unfiltered) concentrations were greater than 10 ng L-1 during high flow events. Total Hg concentrations in stream water were correlated with the total organic fraction of suspended sediment, suggesting the importance of organic material in Hg transport within the catchment. High flow events and transport with organic material may be especially important mechanisms for the movement of Hg through forested ecosystems.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25538576','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25538576"><span>Content congruency and its interplay with temporal synchrony modulate integration between rhythmic audiovisual streams.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Su, Yi-Huang</p> <p>2014-01-01</p> <p>Both lower-level stimulus factors (e.g., temporal proximity) and higher-level cognitive factors (e.g., content congruency) are known to influence multisensory integration. The former can direct attention in a converging manner, and the latter can indicate whether information from the two modalities belongs together. The present research investigated whether and how these two factors interacted in the perception of rhythmic, audiovisual (AV) streams derived from a human movement scenario. Congruency here was based on sensorimotor correspondence pertaining to rhythm perception. Participants attended to bimodal stimuli consisting of a humanlike figure moving regularly to a sequence of auditory beat, and detected a possible auditory temporal deviant. The figure moved either downwards (congruently) or upwards (incongruently) to the downbeat, while in both situations the movement was either synchronous with the beat, or lagging behind it. Greater cross-modal binding was expected to hinder deviant detection. Results revealed poorer detection for congruent than for incongruent streams, suggesting stronger integration in the former. False alarms increased in asynchronous stimuli only for congruent streams, indicating greater tendency for deviant report due to visual capture of asynchronous auditory events. In addition, a greater increase in perceived synchrony was associated with a greater reduction in false alarms for congruent streams, while the pattern was reversed for incongruent ones. These results demonstrate that content congruency as a top-down factor not only promotes integration, but also modulates bottom-up effects of synchrony. Results are also discussed regarding how theories of integration and attentional entrainment may be combined in the context of rhythmic multisensory stimuli.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/947313-experimental-investigation-effect-walls-gas-liquid-flows-through-fixed-particle-beds','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/947313-experimental-investigation-effect-walls-gas-liquid-flows-through-fixed-particle-beds"><span>An experimental investigation of the effect of walls on gas-liquid flows through fixed particle beds.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Cooper, Marcia A.; Cote, Raymond O.; Torczynski, John Robert</p> <p></p> <p>The effect of particle diameter on downward co-current gas-liquid flow through a fixed bed of particles confined within a cylindrical column is investigated. Several hydrodynamic regimes that depend strongly on the properties of the gas stream, the liquid stream, and the packed particle bed are known to exist within these systems. This experimental study focuses on characterizing the effect of wall confinement on these hydrodynamic regimes as the diameter d of the spherical particles becomes comparable to the column diameter D (or D/d becomes order-unity). The packed bed consists of polished, solid, spherical, monodisperse particles (beads) with mean diameter inmore » the range of 0.64-2.54 cm. These diameters yield D/d values between 15 and 3.75, so this range overlaps and extends the previously investigated range for two-phase flow, Measurements of the pressure drop across the bed and across the pulses are obtained for varying gas and liquid flow rates.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/840693','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/840693"><span>Use of Thermal Data to Estimate Infiltration in Pagany Wash Associated with the winter of 1997-1998 El Nino Precipitation, Yucca Mountain, Nevada</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>G.D. LeCain; N. lu; M. Kurzmack</p> <p></p> <p>Temperature and air-pressure monitoring in a vertical borehole located in Pagany Wash, a normally dry stream-carved channel northeast of Yucca Mountain, Nevada, indicated that the annual temperature wave was measurable to a depth of 11.1 m. Temperature depressions were measured at depths of 3.1, 6.1, 9.2, and 11.1 m below ground surface. The temperature depressions were interpreted to be the result of infiltration associated with the 1997-1998 El Nino precipitation. A pressure differential, of approximately 2 kiloPascals, between stations located 11.1 and 24.5 m below ground surface was interpreted to be the result of compressed air ahead of the wettingmore » front. The pressure differences between stations indicated that the wetting front migrated deeper than 35.2 m and that the Yucca Mountain Tuff retarded the downward movement of the wetting front. An analytical method indicated that the infiltration flux through the Pagany Wash alluvium due to the 1997-1998 El Nino precipitation was approximately 940 mm. A one-dimensional numerical model indicated that the infiltration flux was approximately 1000 mm. Sensitivity analysis indicated that the potential temperature decrease due to conduction was minimal and that cooler surface temperatures could not account for the measured subsurface temperature depressions.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_5 --> <div id="page_6" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="101"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70032008','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70032008"><span>Artificial recharge through a thick, heterogeneous unsaturated zone</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Izbicki, J.A.; Flint, A.L.; Stamos, C.L.</p> <p>2008-01-01</p> <p>Thick, heterogeneous unsaturated zones away from large streams in desert areas have not previously been considered suitable for artificial recharge from ponds. To test the potential for recharge in these settings, 1.3 ?? 10 6 m3 of water was infiltrated through a 0.36-ha pond along Oro Grande Wash near Victorville, California, between October 2002 and January 2006. The pond overlies a regional pumping depression 117 m below land surface and is located where thickness and permeability of unsaturated deposits allowed infiltration and saturated alluvial deposits were sufficiently permeable to allow recovery of water. Because large changes in water levels caused by nearby pumping would obscure arrival of water at the water table, downward movement of water was measured using sensors in the unsaturated zone. The downward rate of water movement was initially as high as 6 m/d and decreased with depth to 0.07 m/d; the initial time to reach the water table was 3 years. After the unsaturated zone was wetted, water reached the water table in 1 year. Soluble salts and nitrate moved readily with the infiltrated water, whereas arsenic and chromium were less mobile. Numerical simulations done using the computer program TOUGH2 duplicated the downward rate of water movement, accumulation of water on perched zones, and its arrival at the water table. Assuming 10 ?? 10 6 m3 of recharge annually for 20 years, a regional ground water flow model predicted water level rises of 30 m beneath the ponds, and rises exceeding 3 m in most wells serving the nearby urban area.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/863951','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/863951"><span>Process for vaporizing a liquid hydrocarbon fuel</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Szydlowski, Donald F.; Kuzminskas, Vaidotas; Bittner, Joseph E.</p> <p>1981-01-01</p> <p>The object of the invention is to provide a process for vaporizing liquid hydrocarbon fuels efficiently and without the formation of carbon residue on the apparatus used. The process includes simultaneously passing the liquid fuel and an inert hot gas downwardly through a plurality of vertically spaed apart regions of high surface area packing material. The liquid thinly coats the packing surface, and the sensible heat of the hot gas vaporizes this coating of liquid. Unvaporized liquid passing through one region of packing is uniformly redistributed over the top surface of the next region until all fuel has been vaporized using only the sensible heat of the hot gas stream.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.H32E..05B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.H32E..05B"><span>Strong seepage of shallow groundwater shifts the timing of the annual thermal signals in stream water</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Briggs, M. A.; Johnson, Z. C.; Snyder, C.; Hitt, N. P.; White, E. A.; Lane, J. W., Jr.; Nelms, D. L.</p> <p>2016-12-01</p> <p>Conventional wisdom indicates that while short-term (e.g. diurnal) thermal variance in streams may be attenuated by groundwater seepage, annual temperature swings will essentially track the local air temperature signal. However, the temperature of shallow (less than 5 m depth) groundwater from seepage zones may not be constant and near the local mean air temperature, but instead will fluctuate seasonally, and show a pronounced phase lag from the annual air signal. The degree of phase lag will be dependent on the rate of vertical fluid and heat exchange through shallow aquifer sediments. Gaining headwater streams might be expected to adopt similar phase lags to local seepage zones. We explore these dynamics through 9 mountain watersheds in Shenandoah National Park, VA, USA that harbor critical habitat for cold-water brook trout (Salvelinus fontinalis). Daily paired air and stream water temperature records were collected for up to 5 years at several stream locations along each watershed. Sinusoids fit to multiple-year data from more than 100 total locations indicate an average phase shift from air to surface water of approximately 10 d; this may primarily be due to strong conductive exchange with the rocky alluvial aquifer in generally incised and shaded channels. A subset of these transects (n=4) showed phase-lags greater than 20 d, coinciding with locations of particularly pronounced diurnal variance attenuation, indicating strong groundwater influence. Shallow bedrock, evaluated throughout the watersheds with passive seismic methods, restricts downward infiltration of precipitation in the mountain bedrock aquifers. Numerical 1D vertical aquifer models indicate similar phase lags in shallow groundwater at the bedrock contact to that observed in stream seepage zones. Therefore, contrary to conventional wisdom, shaded mountain streams with strong groundwater influence may adopt the annual thermal signature of the adjacent aquifer, shifting the stream thermal maxima timing from that predicted by air temperature. This research illustrates the utility of long-term paired air/stream thermal records, which further refine the evaluation of apparent groundwater influence to aquatic habitat.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.H23E1009M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.H23E1009M"><span>A Conceptual Hydrogeologic Model of the Vicinity of DUSEL Homestake</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Murdoch, L. C.; Germanovich, L. N.; Boutt, D. F.; Kieft, T. L.; Wang, H. F.; Onstott, T. C.</p> <p>2009-12-01</p> <p>The Deep Underground Science and Engineering Laboratory (DUSEL) is a research facility planned to occupy the workings of the former Homestake gold mine in the northern Black Hills, South Dakota. The hydrogeology was of minor importance to locating and recovering gold ore, so it was overlooked during mining and is relatively unknown. This knowledge gap hinders planning of the Deep EcoHydrology Experiment at DUSEL and motivated the work described here. The conceptual hydrogeologic model is characterized by permeability that is assumed to be anisotropic and controlled by regional foliation, which strikes approximately N20W and dips steeply to the NE. Permeability is on the order of 0.1 mD in fresh rock, but increases to roughly 100 mD at shallow depths. The permeability distribution is assumed to result from unloading of the foliated rock, and a simple model of stress-dependence explains the permeability distribution and suggests that the more permeable zone is on the order of ~100 m thick. A stream hydrograph from Whitetail Creek (station 06436156) was analyzed to estimate recharge flux and the result indicates an average value of approximately 5 x 10-9 m/s. A numerical model of the vicinity of the mine was developed by representing the mine workings as a dual- porosity inclusion embedded in a single-porosity, anisotropic material. The extent of the dual-porosity medium was advanced downward based on the mining records and the hydraulic head within the material representing the mine workings was adjusted to represent filling and draining of the workings. The results suggest that the groundwater is characterized by a shallow flow system of distributed recharge that mostly discharges to nearby streams. The mine itself acts like a large sink that moves downward and to the southeast during mining, and then is controlled by variations in pumping rate once the mine reaches its greatest depth. The deep flow system consists of (i) a zone of relatively rapid flow from the ground surface to the mine workings overlying the southern part of the mine, and (ii) a much larger ellipsoidal zone extending up to several km from the workings where water has been removed from storage. Maximum downward fluxes in the deep system are less than the recharge rate because flow occurs at unit head gradient and the permeability of the rock is relatively low (~0.1 mD). This explains why dewatering has negligible impact on overlying streams and suggests that the regional water table remains within the shallow flow system. The results also indicate that water on the southern side of the mine is probably quite young (<~1 yr) and influenced by recent recharge, whereas water on the north side is much older and affected by removal from storage in deep pore space. The observed dewatering rate at the mine can be explained without requiring additional inflow from a large open pit or other surficial workings.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/tm/2006/tm6A13/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/tm/2006/tm6A13/"><span>Documentation of the Streamflow-Routing (SFR2) Package to Include Unsaturated Flow Beneath Streams - A Modification to SFR1</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Niswonger, Richard G.; Prudic, David E.</p> <p>2005-01-01</p> <p>Many streams in the United States, especially those in semiarid regions, have reaches that are hydraulically disconnected from underlying aquifers. Ground-water withdrawals have decreased water levels in valley aquifers beneath streams, increasing the occurrence of disconnected streams and aquifers. The U.S. Geological Survey modular ground-water model (MODFLOW-2000) can be used to model these interactions using the Streamflow-Routing (SFR1) Package. However, the approach does not consider unsaturated flow between streams and aquifers and may not give realistic results in areas with significantly deep unsaturated zones. This documentation describes a method for extending the capabilities of MODFLOW-2000 by incorporating the ability to simulate unsaturated flow beneath streams. A kinematic-wave approximation to Richards' equation was solved by the method of characteristics to simulate unsaturated flow beneath streams in SFR1. This new package, called SFR2, includes all the capabilities of SFR1 and is designed to be used with MODFLOW-2000. Unlike SFR1, seepage loss from the stream may be restricted by the hydraulic conductivity of the unsaturated zone. Unsaturated flow is simulated independently of saturated flow within each model cell corresponding to a stream reach whenever the water table (head in MODFLOW) is below the elevation of the streambed. The relation between unsaturated hydraulic conductivity and water content is defined by the Brooks-Corey function. Unsaturated flow variables specified in SFR2 include saturated and initial water contents; saturated vertical hydraulic conductivity; and the Brooks-Corey exponent. These variables are defined independently for each stream reach. Unsaturated flow in SFR2 was compared to the U.S. Geological Survey's Variably Saturated Two-Dimensional Flow and Transport (VS2DT) Model for two test simulations. For both test simulations, results of the two models were in good agreement with respect to the magnitude and downward progression of a wetting front through an unsaturated column. A third hypothetical simulation is presented that includes interaction between a stream and aquifer separated by an unsaturated zone. This simulation is included to demonstrate the utility of unsaturated flow in SFR2 with MODFLOW-2000. This report includes a description of the data input requirements for simulating unsaturated flow in SFR2.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70045371','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70045371"><span>Descriptions and characterizations of water-level data and groundwater flow for the Brewster Boulevard and Castle Hayne Aquifer Systems and the Tarawa Terrace Aquifer</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Faye, Robert E.; Jones, L. Elliott; Suárez-Soto, René J.</p> <p>2013-01-01</p> <p>This supplement of Chapter A (Supplement 3) summarizes results of analyses of groundwater-level data and describes corresponding elements of groundwater flow such as vertical hydraulic gradients useful for groundwater-flow model calibration. Field data as well as theoretical concepts indicate that potentiometric surfaces within the study area are shown to resemble to a large degree a subdued replica of surface topography. Consequently, precipitation that infiltrates to the water table flows laterally from highland to lowland areas and eventually discharges to streams such as Northeast and Wallace Creeks and New River. Vertically downward hydraulic gradients occur in highland areas resulting in the transfer of groundwater from shallow relatively unconfined aquifers to underlying confined or semi-confined aquifers. Conversely, in the vicinity of large streams such as Wallace and Frenchs Creeks, diffuse upward leakage occurs from underlying confined or semi-confined aquifers. Point water-level data indicating water-table altitudes, water-table altitudes estimated using a regression equation, and estimates of stream levels determined from a digital elevation model (DEM) and topographic maps were used to estimate a predevelopment water-table surface in the study area. Approximate flow lines along hydraulic gradients are shown on a predevelopment potentiometric surface map and extend from highland areas where potentiometric levels are greatest toward streams such as Wallace Creek and Northeast Creek. The distribution of potentiometric levels and corresponding groundwater-flow directions conform closely to related descriptions of the conceptual model.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5716353','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5716353"><span>Differential hemispheric and visual stream contributions to ensemble coding of crowd emotion</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Im, Hee Yeon; Albohn, Daniel N.; Steiner, Troy G.; Cushing, Cody A.; Adams, Reginald B.; Kveraga, Kestutis</p> <p>2017-01-01</p> <p>In crowds, where scrutinizing individual facial expressions is inefficient, humans can make snap judgments about the prevailing mood by reading “crowd emotion”. We investigated how the brain accomplishes this feat in a set of behavioral and fMRI studies. Participants were asked to either avoid or approach one of two crowds of faces presented in the left and right visual hemifields. Perception of crowd emotion was improved when crowd stimuli contained goal-congruent cues and was highly lateralized to the right hemisphere. The dorsal visual stream was preferentially activated in crowd emotion processing, with activity in the intraparietal sulcus and superior frontal gyrus predicting perceptual accuracy for crowd emotion perception, whereas activity in the fusiform cortex in the ventral stream predicted better perception of individual facial expressions. Our findings thus reveal significant behavioral differences and differential involvement of the hemispheres and the major visual streams in reading crowd versus individual face expressions. PMID:29226255</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140004933','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140004933"><span>Evidence of Multiple Reconnection Lines at the Magnetopause from Cusp Observations</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Trattner, K. J.; Petrinec, S. M.; Fuselier, S. A.; Omidi, N.; Sibeck, David Gary</p> <p>2012-01-01</p> <p>Recent global hybrid simulations investigated the formation of flux transfer events (FTEs) and their convection and interaction with the cusp. Based on these simulations, we have analyzed several Polar cusp crossings in the Northern Hemisphere to search for the signature of such FTEs in the energy distribution of downward precipitating ions: precipitating ion beams at different energies parallel to the ambient magnetic field and overlapping in time. Overlapping ion distributions in the cusp are usually attributed to a combination of variable ion acceleration during the magnetopause crossing together with the time-of-flight effect from the entry point to the observing satellite. Most "step up" ion cusp structures (steps in the ion energy dispersions) only overlap for the populations with large pitch angles and not for the parallel streaming populations. Such cusp structures are the signatures predicted by the pulsed reconnection model, where the reconnection rate at the magnetopause decreased to zero, physically separating convecting flux tubes and their parallel streaming ions. However, several Polar cusp events discussed in this study also show an energy overlap for parallel-streaming precipitating ions. This condition might be caused by reopening an already reconnected field line, forming a magnetic island (flux rope) at the magnetopause similar to that reported in global MHD and Hybrid simulations</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MNRAS.450..575A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MNRAS.450..575A"><span>On feathers, bifurcations and shells: the dynamics of tidal streams across the mass scale</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Amorisco, N. C.</p> <p>2015-06-01</p> <p>I present an organic description of the spectrum of regimes of collisionless tidal streams and define the orderings between the relevant physical quantities that shape their morphology. Three fundamental dichotomies are identified and described in the form of dimensionless inequalities. These govern (i) the speed of the stream's growth, (ii) the internal coherence of the stream and (iii) its thickness or opening angle, within and outside the orbital plane. The mechanisms through which such main qualitative properties are regulated and the relevant limiting cases are analysed. For example, the slope of the host's density profile strongly influences the speed of the stream's growth, in both length and width, as steeper density profiles enhance differential streaming. Internal coherence is the natural requirement for the appearance of substructure and overdensities in tidal debris, and I concentrate on the characteristic `feathering' typical of streams of star clusters. Overdensities and substructures are associated with minima in the relative streaming velocity of the stream members. For streams with high circularity, these are caused by the epicyclic oscillations of stars; however, for highly non-circular progenitor's orbits, internal substructure is caused by the oscillating differences in energy and actions with which material is shed at different orbital phases of the progenitor. This modulation results in different streaming speeds along the tidal arm: the streakline of material shed between two successive apocentric passages is folded along its length, pulled at its centre by the faster differential streaming of particles released near pericentre, which are therefore more widely scattered. When the stream is coherent enough, the same mechanism is potentially capable of generating a bimodal profile in the density distributions of the longer wraps of more massive progenitors, which I dub `bifurcations'. The conditions that allow streams to be internally coherent are explored and I comment on the cases of Palomar 5, Willman 1, the Anticenter and Sagittarius' streams. Analytical methods are accompanied by numerical experiments, performed using a purposely built generative model, also presented here.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21951631','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21951631"><span>Bottlenecks drive temporal and spatial genetic changes in alpine caddisfly metapopulations.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shama, Lisa N S; Kubow, Karen B; Jokela, Jukka; Robinson, Christopher T</p> <p>2011-09-27</p> <p>Extinction and re-colonisation of local populations is common in ephemeral habitats such as temporary streams. In most cases, such population turnover leads to reduced genetic diversity within populations and increased genetic differentiation among populations due to stochastic founder events, genetic drift, and bottlenecks associated with re-colonisation. Here, we examined the spatio-temporal genetic structure of 8 alpine caddisfly populations inhabiting permanent and temporary streams from four valleys in two regions of the Swiss Alps in years before and after a major stream drying event, the European heat wave in summer 2003. We found that population turnover after 2003 led to a loss of allelic richness and gene diversity but not to significant changes in observed heterozygosity. Within all valleys, permanent and temporary streams in any given year were not differentiated, suggesting considerable gene flow and admixture between streams with differing hydroperiods. Large changes in allele frequencies after 2003 resulted in a substantial increase in genetic differentiation among valleys within one to two years (1-2 generations) driven primarily by drift and immigration. Signatures of genetic bottlenecks were detected in all 8 populations after 2003 using the M-ratio method, but in no populations when using a heterozygosity excess method, indicating differential sensitivity of bottleneck detection methods. We conclude that genetic differentiation among A. uncatus populations changed markedly both temporally and spatially in response to the extreme climate event in 2003. Our results highlight the magnitude of temporal population genetic changes in response to extreme events. More specifically, our results show that extreme events can cause rapid genetic divergence in metapopulations. Further studies are needed to determine if recovery from this perturbation through gradual mixing of diverged populations by migration and gene flow leads to the pre-climate event state, or whether the observed changes represent a new genetic equilibrium.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004ASAJ..116.1656F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004ASAJ..116.1656F"><span>Auditory stream segregation in monkey auditory cortex: effects of frequency separation, presentation rate, and tone duration</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fishman, Yonatan I.; Arezzo, Joseph C.; Steinschneider, Mitchell</p> <p>2004-09-01</p> <p>Auditory stream segregation refers to the organization of sequential sounds into ``perceptual streams'' reflecting individual environmental sound sources. In the present study, sequences of alternating high and low tones, ``...ABAB...,'' similar to those used in psychoacoustic experiments on stream segregation, were presented to awake monkeys while neural activity was recorded in primary auditory cortex (A1). Tone frequency separation (ΔF), tone presentation rate (PR), and tone duration (TD) were systematically varied to examine whether neural responses correlate with effects of these variables on perceptual stream segregation. ``A'' tones were fixed at the best frequency of the recording site, while ``B'' tones were displaced in frequency from ``A'' tones by an amount=ΔF. As PR increased, ``B'' tone responses decreased in amplitude to a greater extent than ``A'' tone responses, yielding neural response patterns dominated by ``A'' tone responses occurring at half the alternation rate. Increasing TD facilitated the differential attenuation of ``B'' tone responses. These findings parallel psychoacoustic data and suggest a physiological model of stream segregation whereby increasing ΔF, PR, or TD enhances spatial differentiation of ``A'' tone and ``B'' tone responses along the tonotopic map in A1.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25442423','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25442423"><span>Local adaptation despite high gene flow in the waterfall-climbing Hawaiian goby, Sicyopterus stimpsoni.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Moody, K N; Hunter, S N; Childress, M J; Blob, R W; Schoenfuss, H L; Blum, M J; Ptacek, M B</p> <p>2015-02-01</p> <p>Environmental heterogeneity can promote the emergence of locally adapted phenotypes among subpopulations of a species, whereas gene flow can result in phenotypic and genotypic homogenization. For organisms like amphidromous fishes that change habitats during their life history, the balance between selection and migration can shift through ontogeny, making the likelihood of local adaptation difficult to predict. In Hawaiian waterfall-climbing gobies, it has been hypothesized that larval mixing during oceanic dispersal counters local adaptation to contrasting topographic features of streams, like slope gradient, that can select for predator avoidance or climbing ability in juvenile recruits. To test this hypothesis, we used morphological traits and neutral genetic markers to compare phenotypic and genotypic distributions in recruiting juveniles and adult subpopulations of the waterfall-climbing amphidromous goby, Sicyopterus stimpsoni, from the islands of Hawai'i and Kaua'i. We found that body shape is significantly different between adult subpopulations from streams with contrasting slopes and that trait divergence in recruiting juveniles tracked stream topography more so than morphological measures of adult subpopulation differentiation. Although no evidence of population genetic differentiation was observed among adult subpopulations, we observed low but significant levels of spatially and temporally variable genetic differentiation among juvenile cohorts, which correlated with morphological divergence. Such a pattern of genetic differentiation is consistent with chaotic genetic patchiness arising from variable sources of recruits to different streams. Thus, at least in S. stimpsoni, the combination of variation in settlement cohorts in space and time coupled with strong postsettlement selection on juveniles as they migrate upstream to adult habitats provides the opportunity for morphological adaptation to local stream environments despite high gene flow. © 2014 John Wiley & Sons Ltd.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100038463','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100038463"><span>Separation of Lift-Generated Vortex Wakes Into Two Diverging Parts</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rossow, Vernon J.; Brown, Anthony P.</p> <p>2010-01-01</p> <p>As part of an ongoing study of the spreading rate of lift-generated vortex wakes, the present investigation considers possible reasons as to why segments of lift-generated wakes sometimes depart from the main part of the wake to move rapidly in either an upward or downward direction. It is assumed that deficiencies or enhancements of the lift carry over across the fuselage-shrouded wing are the driving mechanism for departures of wake-segments. The computations presented first indicate that upwardly departing wake segments that were observed and photographed could have been produced by a deficiency in lift carryover across the fuselage-shrouded part of the wing. Computations made of idealized vortex wakes indicate that upward departure of a wake segment requires a centerline reduction in the span loading of 70% or more, whether the engines are at idle or robust thrust. Similarly, it was found that downward departure of wake segments is produced when the lift over the center part of the wing is enhanced. However, it was also found that downward departures do not occur without the presence of robust engine-exhaust streams (i.e., engines must NOT be at idle). In those cases, downward departures of a wake segment occurs when the centerline value of the loading is enhanced by any amount between about 10% to 100%. Observations of condensation trails indicate that downward departure of wake segments is rare. Upward departures of wake segments appears to be more common but still rare. A study to determine the part of the aircraft that causes wake departures has not been carried out. However, even though departures of wake segments rarely occur, some aircraft do regularly shed these wake structures. If aircraft safety is to be assured to a high degree of reliability, and a solution for eliminating them is not implemented, existing guidelines for the avoidance of vortex wakes [1,3] may need to be broadened to include possible increases in wake sizes caused by vertical departures of wake segments. Further study may indicate that it is not possible to modify existing aircraft enough to prevent wake departures. Wake-avoidance guidelines must then be adjusted to provide the desired degree of safety. It appears that steps to avoid upwardly moving wake segments have already been incorporated into the avoidance procedures used for aircraft on approach to runways at the Frankfurt Airport [6,7]. The uncertainty in the prospects for compromises in flight safety caused by rapidly upwardly or downwardly moving wake segments suggest that it be specified that aircraft do not fly above or below each other during operations in the airport vicinity where aircraft are likely to be closely spaced [20].</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/872864','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/872864"><span>Apparatus for removal of particulate matter from gas streams</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Smith, Peyton L.; Morse, John C.</p> <p>2000-01-01</p> <p>An apparatus for the removal of particulate matter from the gaseous product stream of an entrained flow coal gasifier which apparatus includes an initial screen, an intermediate screen which is aligned with the direction of flow of the gaseous product stream and a final screen transversely disposed to the flow of gaseous product and which apparatus is capable of withstanding at least a pressure differential of about 10 psi (68.95 kPa) or greater at the temperatures of the gaseous product stream.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/865423','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/865423"><span>Minimizing corrosion in coal liquid distillation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Baumert, Kenneth L.; Sagues, Alberto A.; Davis, Burtron H.</p> <p>1985-01-01</p> <p>In an atmospheric distillation tower of a coal liquefaction process, tower materials corrosion is reduced or eliminated by introduction of boiling point differentiated streams to boiling point differentiated tower regions.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25024120','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25024120"><span>Trends in childhood mortality in Kenya: the urban advantage has seemingly been wiped out.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kimani-Murage, E W; Fotso, J C; Egondi, T; Abuya, B; Elungata, P; Ziraba, A K; Kabiru, C W; Madise, N</p> <p>2014-09-01</p> <p>We describe trends in childhood mortality in Kenya, paying attention to the urban-rural and intra-urban differentials. We use data from the Kenya Demographic and Health Surveys (KDHS) collected between 1993 and 2008 and the Nairobi Urban Health and Demographic Surveillance System (NUHDSS) collected in two Nairobi slums between 2003 and 2010, to estimate infant mortality rate (IMR), child mortality rate (CMR) and under-five mortality rate (U5MR). Between 1993 and 2008, there was a downward trend in IMR, CMR and U5MR in both rural and urban areas. The decline was more rapid and statistically significant in rural areas but not in urban areas, hence the gap in urban-rural differentials narrowed over time. There was also a downward trend in childhood mortality in the slums between 2003 and 2010 from 83 to 57 for IMR, 33 to 24 for CMR, and 113 to 79 for U5MR, although the rates remained higher compared to those for rural and non-slum urban areas in Kenya. The narrowing gap between urban and rural areas may be attributed to the deplorable living conditions in urban slums. To reduce childhood mortality, extra emphasis is needed on the urban slums. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4158907','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4158907"><span>Trends in childhood mortality in Kenya: The urban advantage has seemingly been wiped out</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kimani-Murage, E.W.; Fotso, J.C.; Egondi, T.; Abuya, B.; Elungata, P.; Ziraba, A.K.; Kabiru, C.W.; Madise, N.</p> <p>2014-01-01</p> <p>Background We describe trends in childhood mortality in Kenya, paying attention to the urban–rural and intra-urban differentials. Methods We use data from the Kenya Demographic and Health Surveys (KDHS) collected between 1993 and 2008 and the Nairobi Urban Health and Demographic Surveillance System (NUHDSS) collected in two Nairobi slums between 2003 and 2010, to estimate infant mortality rate (IMR), child mortality rate (CMR) and under-five mortality rate (U5MR). Results Between 1993 and 2008, there was a downward trend in IMR, CMR and U5MR in both rural and urban areas. The decline was more rapid and statistically significant in rural areas but not in urban areas, hence the gap in urban–rural differentials narrowed over time. There was also a downward trend in childhood mortality in the slums between 2003 and 2010 from 83 to 57 for IMR, 33 to 24 for CMR, and 113 to 79 for U5MR, although the rates remained higher compared to those for rural and non-slum urban areas in Kenya. Conclusions The narrowing gap between urban and rural areas may be attributed to the deplorable living conditions in urban slums. To reduce childhood mortality, extra emphasis is needed on the urban slums. PMID:25024120</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/5504777-buried-marine-depositional-sequence-presumpscot-fm-marine-limit-waterboro-maine','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/5504777-buried-marine-depositional-sequence-presumpscot-fm-marine-limit-waterboro-maine"><span>A buried marine depositional sequence (Presumpscot FM. ) N. of the marine limit, Waterboro, Maine</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Morency, R.E.</p> <p></p> <p>Subsurface investigations conducted in Waterboro, ME (York Co.) in connection with studies of two hazardous waste sites and a municipal water supply exploration project, have demonstrated that a laterally extensive sequence of marine deposits underlies surficial sediments mapped as non-esker ice contact glacio-fluvial deposits. The marine deposits consist of a fining-downwards sequence of grey, micaceous sands (fine to medium, grading down to a silty-fine sand), which grade downward into a thick ([plus minus] 30 feet) grey silt/clay unit, which itself shows a fining-downward trend. The stratigraphy is likely correlative to the Presumpscot Formation, as described by Bloom (1963). The bottommore » of the regressive marine sequence is marked at several locations by a thin layer of sand-sized biotite mica. Lodgement till was encountered only at scattered localities (in boreholes) at each site. The bedrock surface is of considerable relief, with changes of 200--300 feet over short distances detected. The sequence appears to be the record of a rapidly transgressing sea which inundated a valley where outwash had been deposited by meltwater ahead of retreating ice. As the sea retreated, up to 70 feet of sediment was deposited in a continuous, coarsening-upwards sequence. Subsequent to the marine regression, the sediments were reworked in a subaerial (braided stream) environment. The Surficial Geologic Map of Maine shows that the inland limit of late-glacial marine submergence is located approximately 8 miles southwest of Waterboro, in Alfred, Maine. The marine limit in Alfred takes the form of a NNE trending, blunt-ended embayment. The results of this study suggest that the marine embayment once extended northward from Alfred, and is now a buried feature, possibly representing a preglacial valley, which hosted an estuary in late Wisconsonian time.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/864317','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/864317"><span>Decontamination of combustion gases in fluidized bed incinerators</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Leon, Albert M.</p> <p>1982-01-01</p> <p>Sulfur-containing atmospheric pollutants are effectively removed from exit gas streams produced in a fluidized bed combustion system by providing a fluidized bed of particulate material, i.e. limestone and/or dolomite wherein a concentration gradient is maintained in the vertical direction. Countercurrent contacting between upwardly directed sulfur containing combustion gases and descending sorbent particulate material creates a concentration gradient across the vertical extent of the bed characterized in progressively decreasing concentration of sulfur, sulfur dioxide and like contaminants upwardly and decreasing concentration of e.g. calcium oxide, downwardly. In this manner, gases having progressively decreasing sulfur contents contact correspondingly atmospheres having progressively increasing concentrations of calcium oxide thus assuring optimum sulfur removal.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005SPIE.5626.1055A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005SPIE.5626.1055A"><span>Differentiated strategies for improving streaming service quality</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>An, Hui; Chen, Xin-Meng</p> <p>2005-02-01</p> <p>With the explosive growth of streaming services, users are becoming more and more sensitive to its quality of service. To handle these problems, the research community focuses of the application of caching and replication techniques. But most approaches try to find specific strategies of caching of replication that suit for streaming service characteristics and to design some kind of universal policy to deal with all streaming objects. This paper explores the combination of caching and replication for improving streaming service quality and demonstrates that it makes sense to incorporate two technologies. It provides a system model and discusses some related issues of how to determining a refreshable streaming object and which refreshment policies a refreshable object should use.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_6 --> <div id="page_7" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="121"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/33872','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/33872"><span>Does leaf chemistry differentially affect breakdown in tropical versus temperate streams? Importance of standardized analytical techniques to measure leaf chemistry</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Marcelo Ardon; Catherine M. Pringle; Susan L. Eggert</p> <p>2009-01-01</p> <p>Comparisons of the effects of leaf litter chemistry on leaf breakdown rates in tropical vs temperate streams are hindered by incompatibility among studies and across sites of analytical methods used to...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=272298&Lab=NERL&keyword=invertebrates&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=272298&Lab=NERL&keyword=invertebrates&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>Does DNA barcoding improve performance of traditional stream bioassessment metrics?</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Benthic macroinvertebrate community composition is used to assess wetland and stream condition and to help differentiate the effects of stressors among sites. Deoxyribonucleic acid (DNA) barcoding has been promoted as a way to increase taxonomic resolution and, thereby, to increa...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25270984','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25270984"><span>Investigating category- and shape-selective neural processing in ventral and dorsal visual stream under interocular suppression.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ludwig, Karin; Kathmann, Norbert; Sterzer, Philipp; Hesselmann, Guido</p> <p>2015-01-01</p> <p>Recent behavioral and neuroimaging studies using continuous flash suppression (CFS) have suggested that action-related processing in the dorsal visual stream might be independent of perceptual awareness, in line with the "vision-for-perception" versus "vision-for-action" distinction of the influential dual-stream theory. It remains controversial if evidence suggesting exclusive dorsal stream processing of tool stimuli under CFS can be explained by their elongated shape alone or by action-relevant category representations in dorsal visual cortex. To approach this question, we investigated category- and shape-selective functional magnetic resonance imaging-blood-oxygen level-dependent responses in both visual streams using images of faces and tools. Multivariate pattern analysis showed enhanced decoding of elongated relative to non-elongated tools, both in the ventral and dorsal visual stream. The second aim of our study was to investigate whether the depth of interocular suppression might differentially affect processing in dorsal and ventral areas. However, parametric modulation of suppression depth by varying the CFS mask contrast did not yield any evidence for differential modulation of category-selective activity. Together, our data provide evidence for shape-selective processing under CFS in both dorsal and ventral stream areas and, therefore, do not support the notion that dorsal "vision-for-action" processing is exclusively preserved under interocular suppression. © 2014 Wiley Periodicals, Inc.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.9213W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.9213W"><span>Kinematics and dynamics of salt movement driven by sub-salt normal faulting and supra-salt sediment accumulation - combined analogue experiments and analytical calculations</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Warsitzka, Michael; Kukowski, Nina; Kley, Jonas</p> <p>2017-04-01</p> <p>In extensional sedimentary basins, the movement of ductile salt is mainly controlled by the vertical displacement of the salt layer, differential loading due to syn-kinematic deposition, and tectonic shearing at the top and the base of the salt layer. During basement normal faulting, salt either tends to flow downward to the basin centre driven by its own weight or it is squeezed upward due to differential loading. In analogue experiments and analytical models, we address the interplay between normal faulting of the sub-salt basement, compaction and density inversion of the supra-salt cover and the kinematic response of the ductile salt layer. The analogue experiments consist of a ductile substratum (silicone putty) beneath a denser cover layer (sand mixture). Both layers are displaced by normal faults mimicked through a downward moving block within the rigid base of the experimental apparatus and the resulting flow patterns in the ductile layer are monitored and analysed. In the computational models using an analytical approximative solution of the Navier-Stokes equation, the steady-state flow velocity in an idealized natural salt layer is calculated in order to evaluate how flow patterns observed in the analogue experiments can be translated to nature. The analytical calculations provide estimations of the prevailing direction and velocity of salt flow above a sub-salt normal fault. The results of both modelling approaches show that under most geological conditions salt moves downwards to the hanging wall side as long as vertical offset and compaction of the cover layer are small. As soon as an effective average density of the cover is exceeded, the direction of the flow velocity reverses and the viscous material is squeezed towards the elevated footwall side. The analytical models reveal that upward flow occurs even if the average density of the overburden does not exceed the density of salt. By testing various scenarios with different layer thicknesses, displacement rate or lithological parameters of the cover, our models suggest that the reversal of material flow usually requires vertical displacements between 700 and 2000 m. The transition from downward to upward flow occurs at smaller fault displacements, if the initial overburden thickness and the overburden density are high and if sedimentation rate keeps pace with the displacement rate of the sub-salt normal fault.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2005/5216/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2005/5216/"><span>Synthesis of monthly and annual streamflow records (water years 1950-2003) for Big Sandy, Clear, Peoples, and Beaver Creeks in the Milk River basin, Montana</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Parrett, Charles</p> <p>2006-01-01</p> <p>To address concerns expressed by the State of Montana about the apportionment of water in the St. Mary and Milk River basins between Canada and the United States, the International Joint Commission requested information from the United States government about water that originates in the United States but does not cross the border into Canada. In response to this request, the U.S. Geological Survey synthesized monthly and annual streamflow records for Big Sandy, Clear, Peoples, and Beaver Creeks, all of which are in the Milk River basin in Montana, for water years 1950-2003. This report presents the synthesized values of monthly and annual streamflow for Big Sandy, Clear, Peoples, and Beaver Creeks in Montana. Synthesized values were derived from recorded and estimated streamflows. Statistics, including long-term medians and averages and flows for various exceedance probabilities, were computed from the synthesized data. Beaver Creek had the largest median annual discharge (19,490 acre-feet), and Clear Creek had the smallest median annual discharge (6,680 acre-feet). Big Sandy Creek, the stream with the largest drainage area, had the second smallest median annual discharge (9,640 acre-feet), whereas Peoples Creek, the stream with the second smallest drainage area, had the second largest median annual discharge (11,700 acre-feet). The combined median annual discharge for the four streams was 45,400 acre-feet. The largest combined median monthly discharge for the four creeks was 6,930 acre-feet in March, and the smallest combined median monthly discharge was 48 acre-feet in January. The combined median monthly values were substantially smaller than the average monthly values. Overall, synthesized flow records for the four creeks are considered to be reasonable given the prevailing climatic conditions in the region during the 1950-2003 base period. Individual estimates of monthly streamflow may have large errors, however. Linear regression was used to relate logarithms of combined annual streamflow to water years 1950-2003. The results of the regression analysis indicated a significant downward trend (regression line slope was -0.00977) for combined annual streamflow. A regression analysis using data from 1956-2003 indicated a slight, but not significant, downward trend for combined annual streamflow.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/7290574','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/7290574"><span>Controlled catalytic and thermal sequential pyrolysis and hydrolysis of polycarbonate and plastic waste to recover monomers</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Evans, R.J.; Chum, H.L.</p> <p>1994-06-14</p> <p>A process is described using fast pyrolysis to convert a plastic waste feed stream containing polycarbonate and ABS to high value monomeric constituents prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of a given polymer to its high value monomeric constituents prior to a temperature range that causes pyrolysis of other plastic components; selecting an acid or base catalysts and an oxide or carbonate support for treating the feed stream to affect acid or base catalyzed reaction pathways to maximize yield or enhance separation of the high value monomeric constituents of polycarbonate and ABS in the first temperature program range; differentially heating the feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituents prior to pyrolysis or other plastic components; separating the high value monomeric constituents from the polycarbonate to cause pyrolysis to a different high value monomeric constituent of the plastic waste and differentially heating the feed stream at the second higher temperature program range to cause pyrolysis of different high value monomeric constituents; and separating the different high value monomeric constituents. 68 figs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/675811','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/675811"><span>Pyrolysis and hydrolysis of mixed polymer waste comprising polyethylene-terephthalate and polyethylene to sequentially recover [monomers</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Evans, R.J.; Chum, H.L.</p> <p>1998-10-13</p> <p>A process is described for using fast pyrolysis in a carrier gas to convert a plastic waste feed stream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents; selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feed stream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent. 83 figs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/869356','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/869356"><span>Controlled catalystic and thermal sequential pyrolysis and hydrolysis of polycarbonate and plastic waste to recover monomers</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Evans, Robert J.; Chum, Helena L.</p> <p>1994-01-01</p> <p>A process of using fast pyrolysis to convert a plastic waste feed stream containing polycarbonate and ABS to high value monomeric constituents prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of a given polymer to its high value monomeric constituents prior to a temperature range that causes pyrolysis of other plastic components; selecting an acid or base catalysts and an oxide or carbonate support for treating the feed stream to affect acid or base catalyzed reaction pathways to maximize yield or enhance separation of the high value monomeric constituents of polycarbonate and ABS in the first temperature program range; differentially heating the feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituents prior to pyrolysis or other plastic components; separating the high value monomeric constituents from the polycarbonate to cause pyrolysis to a different high value monomeric constituent of the plastic waste and differentially heating the feed stream at the second higher temperature program range to cause pyrolysis of different high value monomeric constituents; and separating the different high value monomeric constituents.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110008093','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110008093"><span>Changing Snow Cover and Stream Discharge in the Western United States - Wind River Range, Wyoming</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hall, Dorothy K.; Foster, James L.; DiGirolamo, Nicolo E.; Barton, Jonathan S.; Riggs, George A.</p> <p>2011-01-01</p> <p>Earlier onset of springtime weather has been documented in the western United States over at least the last 50 years. Because the majority (>70%) of the water supply in the western U.S. comes from snowmelt, analysis of the declining spring snowpack has important implications for the management of water resources. We studied ten years of Moderate-Resolution Imaging Spectroradiometer (MODIS) snow-cover products, 40 years of stream discharge and meteorological station data and 30 years of snow-water equivalent (SWE) SNOw Telemetry (SNOTEL) data in the Wind River Range (WRR), Wyoming. Results show increasing air temperatures for.the 40-year study period. Discharge from streams in WRR drainage basins show lower annual discharge and earlier snowmelt in the decade of the 2000s than in the previous three decades. Changes in streamflow may be related to increasing air temperatures which are probably contributing to a reduction in snow cover, although no trend of either increasingly lower streamflow or earlier snowmelt was observed within the decade of the 2000s. And SWE on 1 April does not show an expected downward trend from 1980 to 2009. The extent of snow cover derived from the lowest-elevation zone of the WRR study area is strongly correlated (r=0.91) with stream discharge on 1 May during the decade of the 2000s. The strong relationship between snow cover and streamflow indicates that MODIS snow-cover maps can be used to improve management of water resources in the drought-prone western U.S.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AdWR..107..354R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AdWR..107..354R"><span>Characterising the dynamics of surface water-groundwater interactions in intermittent and ephemeral streams using streambed thermal signatures</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rau, Gabriel C.; Halloran, Landon J. S.; Cuthbert, Mark O.; Andersen, Martin S.; Acworth, R. Ian; Tellam, John H.</p> <p>2017-09-01</p> <p>Ephemeral and intermittent flow in dryland stream channels infiltrates into sediments, replenishes groundwater resources and underpins riparian ecosystems. However, the spatiotemporal complexity of the transitory flow processes that occur beneath such stream channels are poorly observed and understood. We develop a new approach to characterise the dynamics of surface water-groundwater interactions in dryland streams using pairs of temperature records measured at different depths within the streambed. The approach exploits the fact that the downward propagation of the diel temperature fluctuation from the surface depends on the sediment thermal diffusivity. This is controlled by time-varying fractions of air and water contained in streambed sediments causing a contrast in thermal properties. We demonstrate the usefulness of this method with multi-level temperature and pressure records of a flow event acquired using 12 streambed arrays deployed along a ∼ 12 km dryland channel section. Thermal signatures clearly indicate the presence of water and characterise the vertical flow component as well as the occurrence of horizontal hyporheic flow. We jointly interpret thermal signatures as well as surface and groundwater levels to distinguish four different hydrological regimes: [A] dry channel, [B] surface run-off, [C] pool-riffle sequence, and [D] isolated pools. The occurrence and duration of the regimes depends on the rate at which the infiltrated water redistributes in the subsurface which, in turn, is controlled by the hydraulic properties of the variably saturated sediment. Our results have significant implications for understanding how transitory flows recharge alluvial sediments, influence water quality and underpin dryland ecosystems.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70185753','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70185753"><span>Landscape linkages between geothermal activity and solute composition and ecological response in surface waters draining the Atlantic slope of Costa Rica</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Pringle, Catherine M.; Rowe, Gary L.; Triska, Frank J.; Fernandez, Jose F.; West, John</p> <p>1993-01-01</p> <p>Surface waters draining three different volcanoes in Costa Rica, ranging from dormant to moderately active to explosive, have a wide range of solute compositions that partly reflects the contribution of different types of solute-rich, geothermal waters. Three major physical transport vectors affect flows of geothermally derived solutes: thermally driven convection of volcanic gases and geothermal fluids; lateral and gravity-driven downward transport of geothermal fluids; and wind dispersion of ash, gases, and acid rain. Specific vector combinations interact to determine landscape patterns in solute chemistry and biota: indicator taxa of algae and bacteria reflect factors such as high temperature, wind-driven or hydrologically transported acidity, high concentrations of various solutes, and chemical precipitation reactions. Many streams receiving geothermally derived solutes have high levels of soluble reactive phosphorus (SRP) (up to 400 µg liter−1), a nutrient that is typically not measured in geochemical studies of geothermal waters. Regional differences in levels of SRP and other solutes among volcanoes were typically not significant due to high local variation in solute levels among geothermally modified streams and between geothermally modified and unmodified streams on each volcano. Geothermal activity along the volcanic spine of Costa Rica provides a natural source of phosphorus, silica, and other solutes and plays an important role in determining emergent landscape patterns in the solute chemistry of surface waters and aquatic biota.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70191937','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70191937"><span>Application of hydrologic tools and monitoring to support managed aquifer recharge decision making in the Upper San Pedro River, Arizona, USA</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Lacher, Laurel J.; Turner, Dale S.; Gungle, Bruce W.; Bushman, Brooke M.; Richter, Holly E.</p> <p>2014-01-01</p> <p>The San Pedro River originates in Sonora, Mexico, and flows north through Arizona, USA, to its confluence with the Gila River. The 92-km Upper San Pedro River is characterized by interrupted perennial flow, and serves as a vital wildlife corridor through this semiarid to arid region. Over the past century, groundwater pumping in this bi-national basin has depleted baseflows in the river. In 2007, the United States Geological Survey published the most recent groundwater model of the basin. This model served as the basis for predictive simulations, including maps of stream flow capture due to pumping and of stream flow restoration due to managed aquifer recharge. Simulation results show that ramping up near-stream recharge, as needed, to compensate for downward pumping-related stress on the water table, could sustain baseflows in the Upper San Pedro River at or above 2003 levels until the year 2100 with less than 4.7 million cubic meters per year (MCM/yr). Wet-dry mapping of the river over a period of 15 years developed a body of empirical evidence which, when combined with the simulation tools, provided powerful technical support to decision makers struggling to manage aquifer recharge to support baseflows in the river while also accommodating the economic needs of the basin.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70146975','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70146975"><span>Spatial structure of morphological and neutral genetic variation in Brook Trout</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Kazyak, David C.; Hilderbrand, Robert H.; Keller, Stephen R.; Colaw, Mark C.; Holloway, Amanda E.; Morgan, Raymond P.; King, Timothy L.</p> <p>2015-01-01</p> <p>Brook Trout Salvelinus fontinalis exhibit exceptional levels of life history variation, remarkable genetic variability, and fine-scale population structure. In many cases, neighboring populations may be highly differentiated from one another to an extent that is comparable with species-level distinctions in other taxa. Although genetic samples have been collected from hundreds of populations and tens of thousands of individuals, little is known about whether differentiation at neutral markers reflects phenotypic differences among Brook Trout populations. We compared differentiation in morphology and neutral molecular markers among populations from four geographically proximate locations (all within 24 km) to examine how genetic diversity covaries with morphology. We found significant differences among and/or within streams for all three morphological axes examined and identified the source stream of many individuals based on morphology (52.3% classification efficiency). Although molecular and morphological differentiation among streams ranged considerably (mean pairwise FST: 0.023–0.264; pairwise PST: 0.000–0.339), the two measures were not significantly correlated. While in some cases morphological characters appear to have diverged to a greater extent than expected by neutral genetic drift, many traits were conserved to a greater extent than were neutral genetic markers. Thus, while Brook Trout exhibit fine-scale spatial patterns in both morphology and neutral genetic diversity, these types of biological variabilities are being structured by different ecological and evolutionary processes. The relative influences of genetic drift versus selection and phenotypic plasticity in shaping morphology appear to vary among populations occupying nearby streams.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27504609','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27504609"><span>Differential modulation of visual object processing in dorsal and ventral stream by stimulus visibility.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ludwig, Karin; Sterzer, Philipp; Kathmann, Norbert; Hesselmann, Guido</p> <p>2016-10-01</p> <p>As a functional organization principle in cortical visual information processing, the influential 'two visual systems' hypothesis proposes a division of labor between a dorsal "vision-for-action" and a ventral "vision-for-perception" stream. A core assumption of this model is that the two visual streams are differentially involved in visual awareness: ventral stream processing is closely linked to awareness while dorsal stream processing is not. In this functional magnetic resonance imaging (fMRI) study with human observers, we directly probed the stimulus-related information encoded in fMRI response patterns in both visual streams as a function of stimulus visibility. We parametrically modulated the visibility of face and tool stimuli by varying the contrasts of the masks in a continuous flash suppression (CFS) paradigm. We found that visibility - operationalized by objective and subjective measures - decreased proportionally with increasing log CFS mask contrast. Neuronally, this relationship was closely matched by ventral visual areas, showing a linear decrease of stimulus-related information with increasing mask contrast. Stimulus-related information in dorsal areas also showed a dependency on mask contrast, but the decrease rather followed a step function instead of a linear function. Together, our results suggest that both the ventral and the dorsal visual stream are linked to visual awareness, but neural activity in ventral areas more closely reflects graded differences in awareness compared to dorsal areas. Copyright © 2016 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JPhCS.268a2019M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JPhCS.268a2019M"><span>Attempts at a numerical realisation of stochastic differential equations containing Preisach operator</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McCarthy, S.; Rachinskii, D.</p> <p>2011-01-01</p> <p>We describe two Euler type numerical schemes obtained by discretisation of a stochastic differential equation which contains the Preisach memory operator. Equations of this type are of interest in areas such as macroeconomics and terrestrial hydrology where deterministic models containing the Preisach operator have been developed but do not fully encapsulate stochastic aspects of the area. A simple price dynamics model is presented as one motivating example for our studies. Some numerical evidence is given that the two numerical schemes converge to the same limit as the time step decreases. We show that the Preisach term introduces a damping effect which increases on the parts of the trajectory demonstrating a stronger upwards or downwards trend. The results are preliminary to a broader programme of research of stochastic differential equations with the Preisach hysteresis operator.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27694939','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27694939"><span>Attached biofilms and suspended aggregates are distinct microbial lifestyles emanating from differing hydraulics.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Niederdorfer, Robert; Peter, Hannes; Battin, Tom J</p> <p>2016-10-03</p> <p>Small-scale hydraulics affects microbial behaviour at the cell level 1 , trophic interactions in marine aggregates 2 and the physical structure and function of stream biofilms 3,4 . However, it remains unclear how hydraulics, predictably changing from small streams to large rivers, impacts the structure and biodiversity of complex microbial communities in these ecosystems. Here, we present experimental evidence unveiling hydraulics as a hitherto poorly recognized control of microbial lifestyle differentiation in fluvial ecosystems. Exposing planktonic source communities from stream and floodplain ecosystems to different hydraulic environments revealed strong selective hydraulic pressures but only minor founder effects on the differentiation of attached biofilms and suspended aggregates and their biodiversity dynamics. Key taxa with a coherent phylogenetic underpinning drove this differentiation. Only a few resident and phylogenetically related taxa formed the backbone of biofilm communities, whereas numerous resident taxa characterized aggregate communities. Our findings unveil fundamental differences between biofilms and aggregates and build the basis for a mechanistic understanding of how hydraulics drives the distribution of microbial diversity along the fluvial continuum 5-7 .</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://eric.ed.gov/?q=institutional+AND+theory+AND+vocational+AND+teacher&pg=2&id=EJ729314','ERIC'); return false;" href="https://eric.ed.gov/?q=institutional+AND+theory+AND+vocational+AND+teacher&pg=2&id=EJ729314"><span>School Type and Academic Culture: Evidence for the Differentiation-Polarization Theory</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Van Houtte, Mieke</p> <p>2006-01-01</p> <p>Several decades ago it was shown that the differentiation of pupils into tracks and streams led to a polarization into "anti-school" and "pro-school" cultures. Support for this differentiation-polarization theory is mainly based on case studies. This paper presents findings of a quantitative study in Belgium (Flanders).…</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5387945','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5387945"><span>Practices and attitudes of doctors and patients to downward referral in Shanghai, China</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yu, Wenya; Li, Meina; Nong, Xin; Ding, Tao; Ye, Feng; Liu, Jiazhen; Dai, Zhixing; Zhang, Lulu</p> <p>2017-01-01</p> <p>Objectives In China, the rate of downward referral is relatively low, as most people are unwilling to be referred from hospitals to community health systems (CHSs). The aim of this study was to explore the effect of doctors' and patients' practices and attitudes on their willingness for downward referral and the relationship between downward referral and sociodemographic characteristics. Methods Doctors and patients of 13 tertiary hospitals in Shanghai were stratified through random sampling. The questionnaire surveyed their sociodemographic characteristics, attitudes towards CHSs and hospitals, understanding of downward referral, recognition of the community first treatment system, and downward referral practices and willingness. Descriptive statistics, χ2 test and stepwise logistic regression analysis were employed for statistical analysis. Results Only 20.8% (161/773) of doctors were willing to accept downward referrals, although this proportion was higher among patients (37.6%, 326/866). Doctors' willingness was influenced by education, understanding of downward referral, and perception of health resources in hospitals. Patients' willingness was influenced by marital status, economic factors and recognition of the community first treatment system. Well-educated doctors who do not consider downward referral would increase their workloads and those with a more comprehensive understanding of hospitals and downward referral process were more likely to make a downward referral decision. Single-injury patients fully recognising the community first treatment system were more willing to accept downward referral. Patients' willingness was significantly increased if downward referral was cost-saving. A better medical insurance system was another key factor for patients to accept downward referral decisions, especially for the floating population. Conclusions To increase the rate of downward referral, the Chinese government should optimise the current referral system and conduct universal publicity for downward referral. Doctors and patients should promote understandings of downward referral. Hospitals should realise the necessity of downward referral, effectively reduce workloads and provide continuing education for doctors. Increasing monetary reimbursement is urgent, as is improving the medical insurance system. PMID:28373247</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2017/5033/sir20175033.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2017/5033/sir20175033.pdf"><span>Water resources of Parowan Valley, Iron County, Utah</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Marston, Thomas M.</p> <p>2017-08-29</p> <p>Parowan Valley, in Iron County, Utah, covers about 160 square miles west of the Red Cliffs and includes the towns of Parowan, Paragonah, and Summit. The valley is a structural depression formed by northwest-trending faults and is, essentially, a closed surface-water basin although a small part of the valley at the southwestern end drains into the adjacent Cedar Valley. Groundwater occurs in and has been developed mainly from the unconsolidated basin-fill aquifer. Long-term downward trends in groundwater levels have been documented by the U.S. Geological Survey (USGS) since the mid-1950s. The water resources of Parowan Valley were assessed during 2012 to 2014 with an emphasis on refining the understanding of the groundwater and surface-water systems and updating the groundwater budget.Surface-water discharge of five perennial mountain streams that enter Parowan Valley was measured from 2013 to 2014. The total annual surface-water discharge of the five streams during 2013 to 2014 was about 18,000 acre-feet (acre-ft) compared to the average annual streamflow of about 22,000 acre-ft from USGS streamgages operated on the three largest of these streams from the 1940s to the 1980s. The largest stream, Parowan Creek, contributes more than 50 percent of the annual surface-water discharge to the valley, with smaller amounts contributed by Red, Summit, Little, and Cottonwood Creeks.Average annual recharge to the Parowan Valley groundwater system was estimated to be about 25,000 acre-ft from 1994 to 2013. Nearly all recharge occurs as direct infiltration of snowmelt and rainfall on the Markagunt Plateau east of the valley. Smaller amounts of recharge occur as infiltration of streamflow and unconsumed irrigation water near the east side of the valley on alluvial fans associated with mountain streams at the foot of the Red Cliffs. Subsurface flow from the mountain block to the east of the valley is a significant source of groundwater recharge to the basin-fill aquifer. Groundwater flows from the high-altitude recharge areas downward toward the basin-fill aquifer in Parowan Valley. Almost all groundwater discharge occurs as withdrawals from irrigation wells in the valley with a small amount of discharge from phreatophytic evapotranspiration. Subsurface groundwater discharge to Cedar Valley is likely minimal. Withdrawals from wells during 2013 were about 32,000 acre-ft. The estimated withdrawals from wells from 1994 to 2013 have ranged from 22,000 to 39,000 acre-ft per year. Declining water levels are an indication of the estimated average annual decrease in groundwater storage of 15,000 acre-ft from 1994 to 2013.Groundwater and surface-water samples were collected from 46 sites in Parowan Valley and Cedar Valley near the town of Enoch during June 2013. Groundwater samples from 34 wells were submitted for geochemical analysis. The total dissolved-solids concentration in water from these wells ranged from 142 to 886 milligrams per liter. Results of stable isotope analysis of oxygen and deuterium from groundwater and surface-water samples indicate that most of the groundwater in Parowan Valley and in Cedar Valley near Enoch is similar in isotopic composition to water from mountain streams, which reflects meteoric water recharged in high-altitude areas east of the valley. In addition, results of stable isotope analysis of a subset of samples from wells located near Little Salt Lake may indicate recharge of precipitation that occurred during cooler climatic conditions of the Pleistocene Epoch.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20090011252','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20090011252"><span>Pressure Measurement in Supersonic Air Flow by Differential Absorptive Laser-Induced Thermal Acoustics</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hart, Roger C.; Herring, Gregory C.; Balla, Robert J.</p> <p>2007-01-01</p> <p>Nonintrusive, off-body flow barometry in Mach-2 airflow has been demonstrated in a large-scale supersonic wind tunnel using seedless laser-induced thermal acoustics (LITA). The static pressure of the gas flow is determined with a novel differential absorption measurement of the ultrasonic sound produced by the LITA pump process. Simultaneously, stream-wise velocity and static gas temperature of the same spatially-resolved sample volume were measured with this nonresonant time-averaged LITA technique. Mach number, temperature and pressure have 0.2%, 0.4%, and 4% rms agreement, respectively, in comparison with known free-stream conditions.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_7 --> <div id="page_8" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="141"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.B21H..03W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.B21H..03W"><span>Spatial and temporal patterns of stream burial and its effect on habitat connectivity across headwater stream communities of the Potomac River Basin, USA</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Weitzell, R.; Guinn, S. M.; Elmore, A. J.</p> <p>2012-12-01</p> <p>The process of directing streams into culverts, pipes, or concrete-lined ditches during urbanization, known as stream burial, alters the primary physical, chemical, and biological processes of streams. Knowledge of the cumulative impacts of reduced structure and ecological function within buried stream networks is crucial for informing management of stream ecosystems, in light of continued growth in urban areas, and the uncertain response of freshwater ecosystems to the stresses of global climate change. To address this need, we utilized recently improved stream maps for the Potomac River Basin (PRB) to describe the extent and severity of stream burial across the basin. Observations of stream burial made from high resolution aerial photographs (>1% of total basin area) and a decision tree using spatial statistics from impervious cover data were used to predict stream burial at 4 time-steps (1975, 1990, 2001, 2006). Of the roughly 95,500 kilometers (km) of stream in the PRB, approximately 4551 km (4.76%) were buried by urban development as of 2001. Analysis of county-level burial trends shows differential patterns in the timing and rates of headwater stream burial, which may be due to local development policies, topographical constraints, and/or time since development. Consistently higher rates of stream burial were observed for small streams, decreasing with stream order. Headwater streams (1st-2nd order) are disproportionately affected, with burial rates continuing to increase over time in relation to larger stream orders. Beyond simple habitat loss, headwater burial decreases connectivity among headwater populations and habitats, with potential to affect a wide range of important ecological processes. To quantify changes to regional headwater connectivity we applied a connectivity model based on electrical circuit theory. Circuit-theoretical models function by treating the landscape as a resistance surface, representing hypothesized relationships between landscape features and their differential "resistance" to movement by organisms. A landscape resistance layer was developed and fine-tuned in terms of the habitat use/needs of aquatic invertebrates with terrestrial adult stages, organisms of critical importance to riparian and aquatic ecosystem health. Initial results show significant increases in landscape resistance (isolation) among headwater systems, and corresponding decreases in current flow (movement of organisms) across the increasingly urbanized PRB landscape. Of particular interest, the circuit model highlighted the importance of stream confluences and zero-order (non-channel) headwater areas for movement of organisms between headwater systems that are otherwise highly disconnected, and for which the latter currently receives no legal protection from development.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920007327','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920007327"><span>The role of calcium and calmodulin in the response of roots to gravity</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Evans, Michael L.</p> <p>1992-01-01</p> <p>There is general agreement that, in roots, the primary detection of the gravitropic signal occurs in the columella cells of the cap and that this results in the generation of a signal that moves into the elongation zone causing the asymmetric growth that leads to downward curvature. Recent work has generated considerable evidence that indicates that auxin is the ultimate mediator of differential growth during root (and shoot) gravitropism. Our studies of the time course of curvature, auxin redistribution and/or adaptation, and electrical potential changes in maize roots have led to the following generalizations: (1) downward curvature begins 18 to 32 min following gravistimulation; (2) asymmetric auxin redistribution across the root cap begins at about the same time as curvature or perhaps slight earlier; (3) there is a lag of approx. 15 min in the response of roots to applied auxin; and (4) gravi-induced changes in intracellular potentials of cortical cells within the elongation zone occur within 30 s following stimulation.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=59585&keyword=agriculture+AND+metrics&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=59585&keyword=agriculture+AND+metrics&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>USE OF MACROINVERTEBRATE METRICS TO DIFFERENTIATE BETWEEN THE EFFECTS OF DECREASED CANOPY AND INCREASED EMBEDDEDNESS IN STREAMS IN DRAINING AGRICULTURAL CATCHMENTS</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Reduced canopy as a result of lost riparian vegetation and increased substrate embeddedness as a result of greater inputs of the fine sediments are two environmental stressor gradients that often covary in streams draining agricultural catchments. An understanding of relationship...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28373247','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28373247"><span>Practices and attitudes of doctors and patients to downward referral in Shanghai, China.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yu, Wenya; Li, Meina; Nong, Xin; Ding, Tao; Ye, Feng; Liu, Jiazhen; Dai, Zhixing; Zhang, Lulu</p> <p>2017-04-03</p> <p>In China, the rate of downward referral is relatively low, as most people are unwilling to be referred from hospitals to community health systems (CHSs). The aim of this study was to explore the effect of doctors' and patients' practices and attitudes on their willingness for downward referral and the relationship between downward referral and sociodemographic characteristics. Doctors and patients of 13 tertiary hospitals in Shanghai were stratified through random sampling. The questionnaire surveyed their sociodemographic characteristics, attitudes towards CHSs and hospitals, understanding of downward referral, recognition of the community first treatment system, and downward referral practices and willingness. Descriptive statistics, χ 2 test and stepwise logistic regression analysis were employed for statistical analysis. Only 20.8% (161/773) of doctors were willing to accept downward referrals, although this proportion was higher among patients (37.6%, 326/866). Doctors' willingness was influenced by education, understanding of downward referral, and perception of health resources in hospitals. Patients' willingness was influenced by marital status, economic factors and recognition of the community first treatment system. Well-educated doctors who do not consider downward referral would increase their workloads and those with a more comprehensive understanding of hospitals and downward referral process were more likely to make a downward referral decision. Single-injury patients fully recognising the community first treatment system were more willing to accept downward referral. Patients' willingness was significantly increased if downward referral was cost-saving. A better medical insurance system was another key factor for patients to accept downward referral decisions, especially for the floating population. To increase the rate of downward referral, the Chinese government should optimise the current referral system and conduct universal publicity for downward referral. Doctors and patients should promote understandings of downward referral. Hospitals should realise the necessity of downward referral, effectively reduce workloads and provide continuing education for doctors. Increasing monetary reimbursement is urgent, as is improving the medical insurance system. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70034269','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70034269"><span>Temperature-associated population diversity in salmon confers benefits to mobile consumers</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Ruff, Casey P.; Schindle, Daniel E.; Armstrong, Jonathan B.; Bentle, Kale T.; Brooks, Gabriel T.; Holtgrieve, Gordon W.; McGlauflin, Molly T.; Torgersen, Christian E.; Seeb, James E.</p> <p>2011-01-01</p> <p>Habitat heterogeneity can generate intraspecific diversity through local adaptation of populations. While it is becoming increasingly clear that population diversity can increase stability in species abundance, less is known about how population diversity can benefit consumers that can integrate across population diversity in their prey. Here we demonstrate cascading effects of thermal heterogeneity on trout–salmon interactions in streams where rainbow trout rely heavily on the seasonal availability of anadromous salmon eggs. Water temperature in an Alaskan stream varied spatially from 5°C to 17.5°C, and spawning sockeye salmon showed population differentiation associated with this thermal heterogeneity. Individuals that spawned early in cool regions of the 5 km long stream were genetically differentiated from those spawning in warmer regions later in the season. Sockeye salmon spawning generates a pulsed resource subsidy that supports the majority of seasonal growth in stream-dwelling rainbow trout. The spatial and temporal structuring of sockeye salmon spawn timing in our focal stream extended the duration of the pulsed subsidy compared to a thermally homogeneous stream with a single population of salmon. Further, rainbow trout adopted movement strategies that exploited the multiple pulses of egg subsidies in the thermally heterogeneous stream. Fish that moved to track the resource pulse grew at rates about 2.5 times higher than those that remained stationary or trout in the reference stream with a single seasonal pulse of eggs. Our results demonstrate that habitat heterogeneity can have important effects on the population diversity of dominant species, and in turn, influence their value to species that prey upon them. Therefore, habitat homogenization may have farther-reaching ecological effects than previously considered.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Th%26Ae..23..383J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Th%26Ae..23..383J"><span>Numerical study of unsteady MHD oblique stagnation point flow and heat transfer due to an oscillating stream</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Javed, T.; Ghaffari, A.; Ahmad, H.</p> <p>2016-05-01</p> <p>The unsteady stagnation point flow impinging obliquely on a flat plate in presence of a uniform applied magnetic field due to an oscillating stream has been studied. The governing partial differential equations are transformed into dimensionless form and the stream function is expressed in terms of Hiemenz and tangential components. The dimensionless partial differential equations are solved numerically by using well-known implicit finite difference scheme named as Keller-box method. The obtained results are compared with those available in the literature. It is observed that the results are in excellent agreement with the previous studies. The effects of pertinent parameters involved in the problem namely magnetic parameter, Prandtl number and impinging angle on flow and heat transfer characteristics are illustrated through graphs. It is observed that the influence of magnetic field strength increases the fluid velocity and by the increase of obliqueness parameter, the skin friction increases.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26614689','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26614689"><span>Genome-wide SNPs reveal fine-scale differentiation among wingless alpine stonefly populations and introgression between winged and wingless forms.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dussex, Nicolas; Chuah, Aaron; Waters, Jonathan M</p> <p>2016-01-01</p> <p>Insect flight loss is a repeated phenomenon in alpine habitats, where wing reduction is thought to enhance local recruitment and increase fecundity. One predicted consequence of flight loss is reduced dispersal ability, which should lead to population genetic differentiation and perhaps ultimately to speciation. Using a dataset of 15,123 SNP loci, we present comparative analyses of fine-scale population structure in codistributed Zelandoperla stonefly species, across three parallel altitudinal transects in New Zealand's Rock and Pillar mountain range. We find that winged populations (altitude 200-500 m; Zelandoperla decorata) show no genetic structuring within or among streams, suggesting substantial dispersal mediated by flight. By contrast, wingless populations (Zelandoperla fenestrata; altitude 200-1100 m) exhibit distinct genetic clusters associated with each stream, and additional evidence of isolation by distance within streams. Our data support the hypothesis that wing-loss can initiate diversification in alpine insect populations over small spatial scales. The often deep phylogenetic placement of lowland Z. fenestrata within their stream-specific clades suggests the possibility of independent alpine colonization events for each stream. Additionally, the detection of winged, interspecific hybrid individuals raises the intriguing possibility that a previously flightless lineage could reacquire flight via introgression. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70184630','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70184630"><span>Temperature-profile methods for estimating percolation rates in arid environments</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Constantz, Jim; Tyler, Scott W.; Kwicklis, Edward</p> <p>2003-01-01</p> <p>Percolation rates are estimated using vertical temperature profiles from sequentially deeper vadose environments, progressing from sediments beneath stream channels, to expansive basin-fill materials, and finally to deep fractured bedrock underlying mountainous terrain. Beneath stream channels, vertical temperature profiles vary over time in response to downward heat transport, which is generally controlled by conductive heat transport during dry periods, or by advective transport during channel infiltration. During periods of stream-channel infiltration, two relatively simple approaches are possible: a heat-pulse technique, or a heat and liquid-water transport simulation code. Focused percolation rates beneath stream channels are examined for perennial, seasonal, and ephemeral channels in central New Mexico, with estimated percolation rates ranging from 100 to 2100 mm d−1 Deep within basin-fill and underlying mountainous terrain, vertical temperature gradients are dominated by the local geothermal gradient, which creates a profile with decreasing temperatures toward the surface. If simplifying assumptions are employed regarding stratigraphy and vapor fluxes, an analytical solution to the heat transport problem can be used to generate temperature profiles at specified percolation rates for comparison to the observed geothermal gradient. Comparisons to an observed temperature profile in the basin-fill sediments beneath Frenchman Flat, Nevada, yielded water fluxes near zero, with absolute values <10 mm yr−1 For the deep vadose environment beneath Yucca Mountain, Nevada, the complexities of stratigraphy and vapor movement are incorporated into a more elaborate heat and water transport model to compare simulated and observed temperature profiles for a pair of deep boreholes. Best matches resulted in a percolation rate near zero for one borehole and 11 mm yr−1 for the second borehole.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70034508','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70034508"><span>Fine-scale population structure and riverscape genetics of brook trout (Salvelinus fontinalis) distributed continuously along headwater channel networks</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Kanno, Yoichiro; Vokoun, Jason C.; Letcher, Benjamin H.</p> <p>2011-01-01</p> <p>Linear and heterogeneous habitat makes headwater stream networks an ideal ecosystem in which to test the influence of environmental factors on spatial genetic patterns of obligatory aquatic species. We investigated fine-scale population structure and influence of stream habitat on individual-level genetic differentiation in brook trout (Salvelinus fontinalis) by genotyping eight microsatellite loci in 740 individuals in two headwater channel networks (7.7 and 4.4 km) in Connecticut, USA. A weak but statistically significant isolation-by-distance pattern was common in both sites. In the field, many tagged individuals were recaptured in the same 50-m reaches within a single field season (summer to fall). One study site was characterized with a hierarchical population structure, where seasonal barriers (natural falls of 1.5–2.5 m in height during summer base-flow condition) greatly reduced gene flow and perceptible spatial patterns emerged because of the presence of tributaries, each with a group of genetically distinguishable individuals. Genetic differentiation increased when pairs of individuals were separated by high stream gradient (steep channel slope) or warm stream temperature in this site, although the evidence of their influence was equivocal. In a second site, evidence for genetic clusters was weak at best, but genetic differentiation between individuals was positively correlated with number of tributary confluences. We concluded that the population-level movement of brook trout was limited in the study headwater stream networks, resulting in the fine-scale population structure (genetic clusters and clines) even at distances of a few kilometres, and gene flow was mitigated by ‘riverscape’ variables, particularly by physical barriers, waterway distance (i.e. isolation-by-distance) and the presence of tributaries.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70028145','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70028145"><span>Detection of water quality trends at high, median, and low flow in a Catskill Mountain stream, New York, through a new statistical method</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Murdoch, Peter S.; Shanley, James B.</p> <p>2006-01-01</p> <p>The effects of changes in acid deposition rates resulting from the Clean Air Act Amendments of 1990 should first appear in stream waters during rainstorms and snowmelt, when the surface of the watershed is most hydrologically connected to the stream. Early detection of improved stream water quality is possible if trends at high flow could be separately determined. Trends in concentrations of sulfate (SO42−), nitrate (NO3−), calcium plus magnesium (Ca2++Mg2+), and acid‐neutralizing capacity (ANC) in Biscuit Brook, Catskill Mountains, New York, were assessed through segmented regression analysis (SRA). The method uses annual concentration‐to‐discharge relations to predict concentrations for specific discharges, then compares those annual values to determine trends at specific discharge levels. Median‐flow trends using SRA were comparable to those predicted by the seasonal Kendall tau test and a multiple regression residual analysis. All of these methods show that stream water SO42− concentrations have decreased significantly since 1983; Ca2++Mg2+ concentrations have decreased at a steady but slower rate than SO42−; and ANC shows no trend. The new SRA method, however, reveals trends that differ at specified flow levels. ANC has increased, and NO3−concentrations have decreased at high flows, but neither has changed as significantly at low flows. The general downward trend in SO42− flattened at median flow and reversed at high flow between 1997 and 2002. The reversal of the high‐flow SO42− trend is consistent with increases in SO42− concentrations in both precipitation and soil solutions at Biscuit Brook. Separate calculation of high‐flow trends provides resource managers with an early detection system for assessing changes in water quality resulting from changes in acidic deposition.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.4150C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.4150C"><span>Observed decline of the Atlantic Meridional Overturning circulation 2004 to 2012</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cunningham, Stuart; Smeed, David; Johns, William; Meinen, Chris; Rayner, Darren; Moat, Ben; Duchez, Aurelie; Bryden, Harry; Baringer Molly, O.; McCarthy, Gerard</p> <p>2014-05-01</p> <p>The Atlantic Meridional Overturning Circulation (AMOC) has been observed continuously at 26° N since April 2004. The AMOC and its component parts are monitored by combining a transatlantic array of moored instruments with submarine-cable based measurements of the Gulf Stream and satellite derived Ekman transport. The time series has recently been extended to October 2012 and the results show a downward trend since 2004. From April~2008 to March 2012 the AMOC was an average of 2.7 Sv weaker than in the first four years of observation (95% confidence that the reduction is 0.3 Sv or more). Ekman transport reduced by about 0.2 Sv and the Gulf Stream by 0.5 Sv but most of the change (2.0 Sv) is due to the mid-ocean geostrophic flow. The change of the mid-ocean geostrophic flow represents a strengthening of the subtropical gyre above the thermocline. The increased southward flow of warm waters is balanced by a decrease in the southward flow of Lower North Atlantic Deep Water below 3000 m. The transport of Lower North Atlantic Deep Water slowed by 7% per year (95% confidence that the rate of slowing is greater than 2.5% per year).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004ASAJ..115.2459R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004ASAJ..115.2459R"><span>Auditory stream segregation with multi-tonal complexes in hearing-impaired listeners</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rogers, Deanna S.; Lentz, Jennifer J.</p> <p>2004-05-01</p> <p>The ability to segregate sounds into different streams was investigated in normally hearing and hearing-impaired listeners. Fusion and fission boundaries were measured using 6-tone complexes with tones equally spaced in log frequency. An ABA-ABA- sequence was used in which A represents a multitone complex ranging from either 250-1000 Hz (low-frequency region) or 1000-4000 Hz (high-frequency region). B also represents a multitone complex with same log spacing as A. Multitonal complexes were 100 ms in duration with 20-ms ramps, and- represents a silent interval of 100 ms. To measure the fusion boundary, the first tone of the B stimulus was either 375 Hz (low) or 1500 Hz (high) and shifted downward in frequency with each progressive ABA triplet until the listener pressed a button indicating that a ``galloping'' rhythm was heard. When measuring the fusion boundary, the first tone of the B stimulus was 252 or 1030 Hz and shifted upward with each triplet. Listeners then pressed a button when the ``galloping rhythm ended.'' Data suggest that hearing-impaired subjects have different fission and fusion boundaries than normal-hearing listeners. These data will be discussed in terms of both peripheral and central factors.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/382767-assessment-oil-spill-effects-pink-salmon-populations-following-exxon-valdez-oil-spill-part-early-life-history','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/382767-assessment-oil-spill-effects-pink-salmon-populations-following-exxon-valdez-oil-spill-part-early-life-history"><span>An assessment of oil spill effects on pink salmon populations following the Exxon Valdez oil spill. Part 1: Early life history</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Brannon, E.L.; Moulton, L.L.; Gilbertson, L.G.</p> <p>1995-12-31</p> <p>This paper discusses results of field programs initiated within a few days of the spill and designed to assess spill effects on critical early life stages of pink salmon in postspill years. Samples of water and stream sediments from throughout the spill area were used to define the exposure of pink salmon to residual hydrocarbons from the spill. Mean sediment concentrations of polycyclic aromatic hydrocarbons (PAH) up to 300 ppb were measured in oiled streams in 1989 and generally followed a downward trend toward background in 1990 and 1991. These PAH concentrations were then used in regression analyses of potentialmore » effects on key early life stages of pink salmon. Water samples taken from both nearshore feeding and rearing areas and offshore migratory areas show that hydrocarbon concentrations were from one to four orders of magnitude lower than concentrations reported in the literature to cause acute or chronic effects on fish species. The postspill field and laboratory studies of pink salmon early life stages included examination of potential effects on 1989, 1990, and 1991 eggs, fry, and juveniles. 28 refs., 8 figs., 8 tabs.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=268761&Lab=NHEERL&keyword=bio+AND+remediation&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=268761&Lab=NHEERL&keyword=bio+AND+remediation&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>Differentiating Impacts of Watershed Development from Superfund Sites on Stream Macroinvertebrates</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Urbanization effect models were developed and verified at whole watershed scales to predict and differentiate between effects on aquatic life from diffuse, non-point source (NPS) urbanization in the watershed and effects of known local, site-specific origin point sources, contami...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2007/5282/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2007/5282/"><span>A modified siphon sampler for shallow water</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Diehl, Timothy H.</p> <p>2008-01-01</p> <p>A modified siphon sampler (or 'single-stage sampler') was developed to sample shallow water at closely spaced vertical intervals. The modified design uses horizontal rather than vertical sample bottles. Previous siphon samplers are limited to water about 20 centimeters (cm) or more in depth; the modified design can sample water 10 cm deep. Several mounting options were used to deploy the modified siphon sampler in shallow bedrock streams of Middle Tennessee, while minimizing alteration of the stream bed. Sampling characteristics and limitations of the modified design are similar to those of the original design. Testing showed that the modified sampler collects unbiased samples of suspended silt and clay. Similarity of the intake to the original siphon sampler suggests that the modified sampler would probably take downward-biased samples of suspended sand. Like other siphon samplers, it does not sample isokinetically, and the efficiency of sand sampling can be expected to change with flow velocity. The sampler needs to be located in the main flow of the stream, and is subject to damage from rapid flow and floating debris. Water traps were added to the air vents to detect the flow of water through the sampler, which can cause a strong upward bias in sampled suspended-sediment concentration. Water did flow through the sampler, in some cases even when the top of the air vent remained above water. Air vents need to be extended well above maximum water level to prevent flow through the sampler.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820013284','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820013284"><span>V/STOL Tandem Fan transition section model test. [in the Lewis Research Center 10-by-10 foot wind tunnel</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Simpkin, W. E.</p> <p>1982-01-01</p> <p>An approximately 0.25 scale model of the transition section of a tandem fan variable cycle engine nacelle was tested in the NASA Lewis Research Center 10-by-10 foot wind tunnel. Two 12-inch, tip-turbine driven fans were used to simulate a tandem fan engine. Three testing modes simulated a V/STOL tandem fan airplane. Parallel mode has two separate propulsion streams for maximum low speed performance. A front inlet, fan, and downward vectorable nozzle forms one stream. An auxilliary top inlet provides air to the aft fan - supplying the core engine and aft vectorable nozzle. Front nozzle and top inlet closure, and removal of a blocker door separating the two streams configures the tandem fan for series mode operations as a typical aircraft propulsion system. Transition mode operation is formed by intermediate settings of the front nozzle, blocker door, and top inlet. Emphasis was on the total pressure recovery and flow distortion at the aft fan face. A range of fan flow rates were tested at tunnel airspeeds from 0 to 240 knots, and angles-of-attack from -10 to 40 deg for all three modes. In addition to the model variables for the three modes, model variants of the top inlet were tested in the parallel mode only. These lip variables were: aft lip boundary layer bleed holes, and Three position turning vane. Also a bellmouth extension of the top inlet side lips was tested in parallel mode.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70021183','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70021183"><span>Regional trends in aquatic recovery from acidification in North America and Europe</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Stoddard, J.L.; Jeffries, D.S.; Lukewille, A.; Clair, T.A.; Dillon, P.J.; Driscoll, C.T.; Forsius, M.; Johannessen, M.; Kahl, J.S.; Kellogg, J.H.; Kemp, A.; Mannlo, J.; Monteith, D.T.; Murdoch, Peter S.; Patrick, S.; Rebsdorl, A.; Skjelkvale, B.L.; Stainton, M.P.; Traaen, T.; Van Dam, H.; Webster, K.E.; Wleting, J.; Wllander, A.</p> <p>1999-01-01</p> <p>Rates of acidic deposition from the atmosphere ('acid rain') have decreased throughout the 1980s and 1990s across large portions of North America and Europe. Many recent studies have attributed observed reversals in surface-water acidification at national and regional scales to the declining deposition. To test whether emissions regulations have led to widespread recovery in surface-water chemistry, we analysed regional trends between 1980 and 1995 in indicators of acidification (sulphate, nitrate and base-cation concentrations, and measured (Gran) alkalinity) for 205 lakes and streams in eight regions of North America and Europe. Dramatic differences in trend direction and strength for the two decades are apparent. In concordance with general temporal trends in acidic deposition, lake and stream sulphate concentrations decreased in all regions with the exception of Great Britain all but one of these regions exhibited stronger downward trends in the 1990s than in the 1980s. In contrast, regional declines in lake and stream nitrate concentrations were rare and, when detected, were very small. Recovery in alkalinity, expected wherever strong regional declines in sulphate concentrations have occurred, was observed in all regions of Europe, especially in the 1990s, but in only one region (of five) in North America. We attribute the lack of recovery in three regions (south/central Ontario, the Adirondack/Catskill mountains and midwestern North America) to strong regional declines in base-cation concentrations that exceed the decreases in sulphate concentrations.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.B43B0240L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.B43B0240L"><span>Seasonal Variability of Riverine Geochemistry (87Sr/86Sr, δ13CDIC, δ44/40Ca, and major ions) in Permafrost Watersheds on the North Slope of Alaska</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lehn, G. O.; Jacobson, A. D.; Douglas, T. A.; McClelland, J. W.; Khosh, M. S.; Barker, A. J.</p> <p>2014-12-01</p> <p>Global climate models predict amplified warming at high latitudes, where permafrost soils have historically acted as a carbon sink. As warming occurs, the seasonally thawed active layer will propagate downward into previously frozen mineral-rich soil, releasing carbon and introducing unique chemical weathering signatures into rivers. We use variations in the 87Sr/86Sr, δ13CDIC, δ44/40Ca, and major ion geochemistry of rivers to track seasonal active layer dynamics. We collected water from six streams on the North Slope of Alaska between May and October, 2009 and 2010. All rivers drain continuous permafrost but three drain tussock tundra-dominated watersheds and three drain steeper bedrock catchments with minor tundra coverage. In tundra streams, elevated 87Sr/86Sr ratios, low δ13CDIC values and major ions ([Na+]+[K+]/ [Ca+2]+[Mg+2]) in spring melt runoff suggest flushing of shallow soils with relatively low carbonate content. By July, 87Sr/86Sr ratios stabilize at relatively low values and δ13CDIC at relatively higher values, indicating the active layer thawed into deeper carbonate-rich soils. In bedrock streams, elevated 87Sr/86Sr ratios correlate with high discharge. By late fall, bedrock stream 87Sr/86Sr ratios decrease steadily, consistent with increased carbonate weathering. Nearly constant δ13CDIC values and high [SO4-2] for most of the melt season imply significant sulfuric acid-carbonate weathering in bedrock streams. δ13CDIC values suggest a shift to carbonic acid-carbonate weathering in late 2010, possibly due to limited oxygen for pyrite oxidation during freezing of the active layer. δ44/40Ca values in both tundra and bedrock streams increase during the seasons, suggesting increased uptake of 40Ca by plants. δ44/40Ca values of rivers are at least 0.1-0.2‰ higher than their watershed soils, rocks and sediments, suggesting significant plant uptake. Our findings show how seasonal changes in mineral weathering have potential for tracking active layer dynamics.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003ApJ...597.1190Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003ApJ...597.1190Y"><span>High Spatial Resolution Observations of Pores and the Formation of a Rudimentary Penumbra</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, G.; Xu, Y.; Wang, H.; Denker, C.</p> <p>2003-11-01</p> <p>We present high spatial resolution observation of small-scale magnetic activity in solar active region NOAA 9539. The observations were obtained on 2001 July 15 using the 65 cm vacuum reflector and 25 cm refractor of the Big Bear Solar Observatory (BBSO). The data sets include time series of speckle reconstructed continuum images at 5200 Å, Hα filtergrams (blue line wing, line center, and red line wing), and line-of-sight magnetograms. Two pores, separated by a light bridge, were located in the central part of NOAA 9539. The formation of penumbral filaments near the light bridge indicated a sudden change of the local magnetic field topology from almost vertical to strongly inclined magnetic fields, which allowed cool material previously suspended in a filament to stream downward. During the downward motion of the cool material, Hα Dopplergrams revealed twisted streamlines along the filament. Finally, there are several well-defined Hα brightenings, Ellerman bombs (EBs), occurred near the region where the downflow of materials fell in. The EBs reside near a magnetic inversion line and are stationary, as opposed to EBs associated with moving magnetic features. We also found that the horizontal flow field of the white-light images derived from local correlation tracking is different from the previous observations. The horizontal movements in the superpenumbrae of leading sunspot and the following sunspots are opposite.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70178329','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70178329"><span>In situ quantification of spatial and temporal variability of hyporheic exchange in static and mobile gravel-bed rivers</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Rosenberry, Donald O.; Klos, P. Zion; Neal, Andrew</p> <p>2012-01-01</p> <p>Seepage meters modified for use in flowing water were used to directly measure rates of exchange between surface and subsurface water in a gravel- and cobble bed river in western Pennsylvania, USA (Allegheny River, Q mean = 190 m 3/s) and a sand- and gravel-bed river in Colorado, USA (South Platte River, Q mean = 9??7 m 3/s). Study reaches at the Allegheny River were located downstream from a dam. The bed was stable with moss, algae, and river grass present in many locations. Median seepage was + 0??28 m/d and seepage was highly variable among measurement locations. Upward and downward seepage greatly exceeded the median seepage rate, ranging from + 2??26 (upward) to - 3??76 (downward) m/d. At the South Platte River site, substantial local-scale bed topography as well as mobile bedforms resulted in spatial and temporal variability in seepage greatly in exceedence of the median groundwater discharge rate of 0??24 m/d. Both upward and downward seepage were recorded along every transect across the river with rates ranging from + 2??37 to - 3??40 m/d. Despite a stable bed, which commonly facilitates clogging by fine-grained or organic sediments, seepage rates at the Allegheny River were not reduced relative to those at the South Platte River. Seepage rate and direction depended primarily on measurement position relative to local- and meso-scale bed topography at both rivers. Hydraulic gradients were small at nearly all seepage-measurement locations and commonly were not a good indicator of seepage rate or direction. Therefore, measuring hydraulic gradient and hydraulic conductivity at in-stream piezometers may be misleading if used to determine seepage flux across the sediment-water interface. Such a method assumes that flow between the well screen and sediment-water interface is vertical, which appears to be a poor assumption in coarse-grained hyporheic settings.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3047351','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3047351"><span>Measurement of ocular aberrations in downward gaze using a modified clinical aberrometer</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ghosh, Atanu; Collins, Michael J; Read, Scott A; Davis, Brett A; Iskander, D. Robert</p> <p>2011-01-01</p> <p>Changes in corneal optics have been measured after downward gaze. However, ocular aberrations during downward gaze have not been previously measured. A commercial Shack-Hartmann aberrometer (COAS-HD) was modified by adding a relay lens system and a rotatable beam splitter to allow on-axis aberration measurements in primary gaze and downward gaze with binocular fixation. Measurements with the modified aberrometer (COAS-HD relay system) in primary and downward gaze were validated against a conventional aberrometer. In human eyes, there were significant changes (p<0.05) in defocus C(2,0), primary astigmatism C(2,2) and vertical coma C(3,−1) in downward gaze (25 degrees) compared to primary gaze, indicating the potential influence of biomechanical forces on the optics of the eye in downward gaze. To demonstrate a further clinical application of this modified aberrometer, we measured ocular aberrations when wearing a progressive addition lens (PAL) in primary gaze (0 degree), 15 degrees downward gaze and 25 degrees downward gaze. PMID:21412451</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2006/5238/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2006/5238/"><span>Water-quality trend analysis and sampling design for the Devils Lake Basin, North Dakota, January 1965 through September 2003</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Ryberg, Karen R.; Vecchia, Aldo V.</p> <p>2006-01-01</p> <p>This report presents the results of a study conducted by the U.S. Geological Survey, in cooperation with the North Dakota State Water Commission, the Devils Lake Basin Joint Water Resource Board, and the Red River Joint Water Resource District, to analyze historical water-quality trends in three dissolved major ions, three nutrients, and one dissolved trace element for eight stations in the Devils Lake Basin in North Dakota and to develop an efficient sampling design to monitor the future trends. A multiple-regression model was used to detect and remove streamflow-related variability in constituent concentrations. To separate the natural variability in concentration as a result of variability in streamflow from the variability in concentration as a result of other factors, the base-10 logarithm of daily streamflow was divided into four components-a 5-year streamflow anomaly, an annual streamflow anomaly, a seasonal streamflow anomaly, and a daily streamflow anomaly. The constituent concentrations then were adjusted for streamflow-related variability by removing the 5-year, annual, seasonal, and daily variability. Constituents used for the water-quality trend analysis were evaluated for a step trend to examine the effect of Channel A on water quality in the basin and a linear trend to detect gradual changes with time from January 1980 through September 2003. The fitted upward linear trends for dissolved calcium concentrations during 1980-2003 for two stations were significant. The fitted step trends for dissolved sulfate concentrations for three stations were positive and similar in magnitude. Of the three upward trends, one was significant. The fitted step trends for dissolved chloride concentrations were positive but insignificant. The fitted linear trends for the upstream stations were small and insignificant, but three of the downward trends that occurred during 1980-2003 for the remaining stations were significant. The fitted upward linear trends for dissolved nitrite plus nitrate as nitrogen concentrations during 1987-2003 for two stations were significant. However, concentrations during recent years appear to be lower than those for the 1970s and early 1980s but higher than those for the late 1980s and early 1990s. The fitted downward linear trend for dissolved ammonia concentrations for one station was significant. The fitted linear trends for total phosphorus concentrations for two stations were significant. Upward trends for total phosphorus concentrations occurred from the late 1980s to 2003 for most stations, but a small and insignificant downward trend occurred for one station. Continued monitoring will be needed to determine if the recent trend toward higher dissolved nitrite plus nitrate as nitrogen and total phosphorus concentrations continues in the future. For continued monitoring of water-quality trends in the upper Devils Lake Basin, an efficient sampling design consists of five major-ion, nutrient, and trace-element samples per year at three existing stream stations and at three existing lake stations. This sampling design requires the collection of 15 stream samples and 15 lake samples per year rather than 16 stream samples and 20 lake samples per year as in the 1992-2003 program. Thus, the design would result in a program that is less costly and more efficient than the 1992-2003 program but that still would provide the data needed to monitor water-quality trends in the Devils Lake Basin.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/866813','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/866813"><span>Optically active biological particle distinguishing apparatus</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Salzman, Gary C.; Kupperman, Robert H.</p> <p>1989-01-01</p> <p>The disclosure is directed to organic particle sorting and identification. High frequency pulses of circularly polarized light, alternating between left and right, intersect a fast moving stream of organic particles. Circular intensity differential scattering and linear intensity differential scattering are monitored to uniquely identify a variety of organic particles.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ApJ...755L...4P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ApJ...755L...4P"><span>Search for Point-like Sources of Ultra-high Energy Neutrinos at the Pierre Auger Observatory and Improved Limit on the Diffuse Flux of Tau Neutrinos</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pierre Auger Collaboration; Abreu, P.; Aglietta, M.; Ahlers, M.; Ahn, E. J.; Albuquerque, I. F. M.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Antiči'c, T.; Aramo, C.; Arganda, E.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Badescu, A. M.; Balzer, M.; Barber, K. B.; Barbosa, A. F.; Bardenet, R.; Barroso, S. L. C.; Baughman, B.; Bäuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellétoile, A.; Bellido, J. A.; BenZvi, S.; Berat, C.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanch-Bigas, O.; Blanco, F.; Blanco, M.; Bleve, C.; Blümer, H.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Brogueira, P.; Brown, W. C.; Bruijn, R.; Buchholz, P.; Bueno, A.; Buroker, L.; Burton, R. E.; Caballero-Mora, K. S.; Caccianiga, B.; Caramete, L.; Caruso, R.; Castellina, A.; Catalano, O.; Cataldi, G.; Cazon, L.; Cester, R.; Chauvin, J.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chirinos Diaz, J.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cook, H.; Cooper, M. J.; Coppens, J.; Cordier, A.; Coutu, S.; Covault, C. E.; Creusot, A.; Criss, A.; Cronin, J.; Curutiu, A.; Dagoret-Campagne, S.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; De Donato, C.; de Jong, S. J.; De La Vega, G.; de Mello Junior, W. J. M.; de Mello Neto, J. R. T.; De Mitri, I.; de Souza, V.; de Vries, K. D.; del Peral, L.; del Río, M.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Díaz Castro, M. L.; Diep, P. N.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; dos Anjos, J. C.; Dova, M. T.; D'Urso, D.; Dutan, I.; Ebr, J.; Engel, R.; Erdmann, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipčič, A.; Fliescher, S.; Fracchiolla, C. E.; Fraenkel, E. D.; Fratu, O.; Fröhlich, U.; Fuchs, B.; Gaior, R.; Gamarra, R. F.; Gambetta, S.; García, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Gascon Bravo, A.; Gemmeke, H.; Ghia, P. L.; Giller, M.; Gitto, J.; Glass, H.; Gold, M. S.; Golup, G.; Gomez Albarracin, F.; Gómez Berisso, M.; Gómez Vitale, P. F.; Gonçalves, P.; Gonzalez, J. G.; Gookin, B.; Gorgi, A.; Gouffon, P.; Grashorn, E.; Grebe, S.; Griffith, N.; Grigat, M.; Grillo, A. F.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Herve, A. E.; Hojvat, C.; Hollon, N.; Holmes, V. C.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huber, D.; Huege, T.; Insolia, A.; Ionita, F.; Italiano, A.; Jansen, S.; Jarne, C.; Jiraskova, S.; Josebachuili, M.; Kadija, K.; Kampert, K. H.; Karhan, P.; Kasper, P.; Katkov, I.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kelley, J. L.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapp, J.; Koang, D.-H.; Kotera, K.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kulbartz, J. K.; Kunka, N.; La Rosa, G.; Lachaud, C.; LaHurd, D.; Latronico, L.; Lauer, R.; Lautridou, P.; Le Coz, S.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Lopez Agüera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Lyberis, H.; Maccarone, M. C.; Macolino, C.; Maldera, S.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, J.; Marin, V.; Maris, I. C.; Marquez Falcon, H. R.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martínez Bravo, O.; Martraire, D.; Masías Meza, J. J.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mazur, P. O.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Mertsch, P.; Meurer, C.; Meyhandan, R.; Mi'canovi'c, S.; Micheletti, M. I.; Minaya, I. A.; Miramonti, L.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morales, B.; Morello, C.; Moreno, E.; Moreno, J. C.; Mostafá, M.; Moura, C. A.; Muller, M. A.; Müller, G.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nhung, P. T.; Niechciol, M.; Niemietz, L.; Nierstenhoefer, N.; Nitz, D.; Nosek, D.; Nožka, L.; Oehlschläger, J.; Olinto, A.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Parente, G.; Parizot, E.; Parra, A.; Pastor, S.; Paul, T.; Pech, M.; Peķala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Petrera, S.; Petrolini, A.; Petrov, Y.; Pfendner, C.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Ponce, V. H.; Pontz, M.; Porcelli, A.; Privitera, P.; Prouza, M.; Quel, E. J.; Querchfeld, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rivera, H.; Rizi, V.; Roberts, J.; Rodrigues de Carvalho, W.; Rodriguez, G.; Rodriguez Cabo, I.; Rodriguez Martino, J.; Rodriguez Rojo, J.; Rodríguez-Frías, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Rouillé-d'Orfeuil, B.; Roulet, E.; Rovero, A. C.; Rühle, C.; Saftoiu, A.; Salamida, F.; Salazar, H.; Salesa Greus, F.; Salina, G.; Sánchez, F.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarkar, S.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, A.; Scholten, O.; Schoorlemmer, H.; Schovancova, J.; Schovánek, P.; Schröder, F.; Schulte, S.; Schuster, D.; Sciutto, S. J.; Scuderi, M.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Silva Lopez, H. H.; Sima, O.; 'Smiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Spinka, H.; Squartini, R.; Srivastava, Y. N.; Stanic, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Šuša, T.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Tapia, A.; Tartare, M.; Taşcău, O.; Tcaciuc, R.; Thao, N. T.; Thomas, D.; Tiffenberg, J.; Timmermans, C.; Tkaczyk, W.; Todero Peixoto, C. J.; Toma, G.; Tomankova, L.; Tomé, B.; Tonachini, A.; Travnicek, P.; Tridapalli, D. B.; Tristram, G.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van den Berg, A. M.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Vicha, J.; Videla, M.; Villaseñor, L.; Wahlberg, H.; Wahrlich, P.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Westerhoff, S.; Whelan, B. J.; Widom, A.; Wieczorek, G.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Will, M.; Williams, C.; Winchen, T.; Wommer, M.; Wundheiler, B.; Yamamoto, T.; Yapici, T.; Younk, P.; Yuan, G.; Yushkov, A.; Zamorano Garcia, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.</p> <p>2012-08-01</p> <p>The surface detector array of the Pierre Auger Observatory can detect neutrinos with energy E ν between 1017 eV and 1020 eV from point-like sources across the sky south of +55° and north of -65° declinations. A search has been performed for highly inclined extensive air showers produced by the interaction of neutrinos of all flavors in the atmosphere (downward-going neutrinos), and by the decay of tau leptons originating from tau neutrino interactions in Earth's crust (Earth-skimming neutrinos). No candidate neutrinos have been found in data up to 2010 May 31. This corresponds to an equivalent exposure of ~3.5 years of a full surface detector array for the Earth-skimming channel and ~2 years for the downward-going channel. An improved upper limit on the diffuse flux of tau neutrinos has been derived. Upper limits on the neutrino flux from point-like sources have been derived as a function of the source declination. Assuming a differential neutrino flux k PS · E -2 ν from a point-like source, 90% confidence level upper limits for k PS at the level of ≈5 × 10-7 and 2.5 × 10-6 GeV cm-2 s-1 have been obtained over a broad range of declinations from the searches for Earth-skimming and downward-going neutrinos, respectively.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/6868252','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/6868252"><span>Automatic thermocouple positioner for use in vacuum furnaces</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Mee, D.K.; Stephens, A.E.</p> <p>1980-06-06</p> <p>The invention is a simple and reliable mechanical arrangement for automatically positioning a thermocouple-carrying rod in a vacuum-furnace assembly of the kind including a casing, a furnace mounted in the casing, and a charge-containing crucible mounted in the furnace for vertical movement between a lower (loading) position and a raised (charge-melting) position. In a preferred embodiment, a welded-diaphragm metal bellows is mounted above the furnace, the upper end of the bellows being fixed against movement and the lower end of the bellows being affixed to support means for a thermocouple-carrying rod which is vertically oriented and extends freely through the furnace lid toward the mouth of the crucible. The support means and rod are mounted for relative vertical movement. Before pumpdown of the furnace, the differential pressure acting on the bellows causes it to contract and lift the thermocouple rod to a position where it will not be contacted by the crucible charge when the crucible is elevated to its raised position. During pumpdown, the bellows expands downward, lowering the thermocouple rod and its support. The bellows expands downward beyond a point where downward movement of the thermocouple rod is arrested by contact with the crucible charge and to a point where the upper end of the thermocouple extends well above the thermocouple support. During subsequent melting of the charge, the thermocouple sinks into the melt to provide an accurate measurement of melt temperatures.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/863944','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/863944"><span>Automatic thermocouple positioner for use in vacuum furnaces</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Mee, David K.; Stephens, Albert E.</p> <p>1981-01-01</p> <p>The invention is a simple and reliable mechanical arrangement for automatically positioning a thermocouple-carrying rod in a vacuum-furnace assembly of the kind including a casing, a furnace mounted in the casing, and a charge-containing crucible mounted in the furnace for vertical movement between a lower (loading) position and a raised (charge-melting) position. In a preferred embodiment, a welded-diaphragm metal bellows is mounted above the furnace, the upper end of the bellows being fixed against movement and the lower end of the bellows being affixed to support means for a thermocouple-carrying rod which is vertically oriented and extends freely through the furnace lid toward the mouth of the crucible. The support means and rod are mounted for relative vertical movement. Before pumpdown of the furnace, the differential pressure acting on the bellows causes it to contract and lift the thermocouple rod to a position where it will not be contacted by the crucible charge when the crucible is elevated to its raised position. During pumpdown, the bellows expands downward, lowering the thermocouple rod and its support. The bellows expands downward beyond a point where downward movement of the thermocouple rod is arrested by contact with the crucible charge and to a point where the upper end of the thermocouple extends well above the thermocouple support. During subsequent melting of the charge, the thermocouple sinks into the melt to provide an accurate measurement of melt temperatures.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=190191&keyword=salmon&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=190191&keyword=salmon&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>Differential incorporation of natural spawners vs. artificially planted salmon carcasses in a stream food web: Evidence from delta 15N of juvenile coho salmon</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Placement of salmon carcasses is a common restoration technique in Oregon and Washington streams, with the goal of improving food resources and productivity of juvenile salmon. To explore the effectiveness of this restoration technique, we measured the δ15N of juvenile coho salmo...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4416458','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4416458"><span>Disentangling interoception: insights from focal strokes affecting the perception of external and internal milieus</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Couto, Blas; Adolfi, Federico; Sedeño, Lucas; Salles, Alejo; Canales-Johnson, Andrés; Alvarez-Abut, Pablo; Garcia-Cordero, Indira; Pietto, Marcos; Bekinschtein, Tristan; Sigman, Mariano; Manes, Facundo; Ibanez, Agustin</p> <p>2015-01-01</p> <p>Interoception is the moment-to-moment sensing of the physiological condition of the body. The multimodal sources of interoception can be classified into two different streams of afferents: an internal pathway of signals arising from core structures (i.e., heart, blood vessels, and bronchi) and an external pathway of body-mapped sensations (i.e., chemosensation and pain) arising from peripersonal space. This study examines differential processing along these streams within the insular cortex (IC) and their subcortical tracts connecting frontotemporal networks. Two rare patients presenting focal lesions of the IC (insular lesion, IL) or its subcortical tracts (subcortical lesion, SL) were tested. Internally generated interoceptive streams were assessed through a heartbeat detection (HBD) task, while those externally triggered were tapped via taste, smell, and pain recognition tasks. A differential pattern was observed. The IC patient showed impaired internal signal processing while the SL patient exhibited external perception deficits. Such selective deficits remained even when comparing each patient with a group of healthy controls and a group of brain-damaged patients. These outcomes suggest the existence of distinguishable interoceptive streams. Results are discussed in relation with neuroanatomical substrates, involving a fronto-insulo-temporal network for interoceptive and cognitive contextual integration. PMID:25983697</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/5117275-relationships-between-acid-deposition-watershed-characteristics-stream-chemistry-maryland-coastal-plain-final-report-volume-text-report-may-june','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/5117275-relationships-between-acid-deposition-watershed-characteristics-stream-chemistry-maryland-coastal-plain-final-report-volume-text-report-may-june"><span>Relationships between acid deposition, watershed characteristics, and stream chemistry in Maryland's coastal plain. Final report. Volume 1. Text. Report for May 1984-June 1985</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Campbell, S.; Bartoshesky, J.; Heimbuch, D.</p> <p>1987-06-01</p> <p>Precipitation and stream-water chemistry data were collected from three watersheds in the Coastal Plain region of Maryland during the period May 1984 through June 1985 in an attempt to determine the potential effects of acidic deposition on the chemistry of these streams. The study streams included Lyons Creek, Morgan Creek, and Granny Finley Branch; these streams were chosen based on their differential responses to storm events observed in a survey of Coastal Plain streams in the spring of 1983. Lyons Creek typically exhibited lower pH, acid-neutralizing capacity, and concentrations of base cations than observed in the other streams. Sulfate massmore » balances suggest that the soils in the Lyons Creek watershed also have less affinity for sulfur retention than do soils of the other watersheds. Acidic pulses were observed in all three streams during the spring months; however, the magnitude of these pulses was less than that observed in 1983. Modeling of the relationships between precipitation chemistry, watershed interactions, and stream chemistry suggests that precipitation acidity can influence stream-water acidity, depending upon hydrological conditions and availabiility of acid-neutralizing materials in the watersheds.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040089505&hterms=tea&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dtea','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040089505&hterms=tea&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dtea"><span>Hydrostatic pressure mimics gravitational pressure in characean cells</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Staves, M. P.; Wayne, R.; Leopold, A. C.</p> <p>1992-01-01</p> <p>Hydrostatic pressure applied to one end of a horizontal Chara cell induces a polarity of cytoplasmic streaming, thus mimicking the effect of gravity. A positive hydrostatic pressure induces a more rapid streaming away from the applied pressure and a slower streaming toward the applied pressure. In contrast, a negative pressure induces a more rapid streaming toward and a slower streaming away from the applied pressure. Both the hydrostatic pressure-induced and gravity-induced polarity of cytoplasmic streaming respond identically to cell ligation, UV microbeam irradiation, external Ca2+ concentrations, osmotic pressure, neutral red, TEA Cl-, and the Ca2+ channel blockers nifedipine and LaCl3. In addition, hydrostatic pressure applied to the bottom of a vertically-oriented cell can abolish and even reverse the gravity-induced polarity of cytoplasmic streaming. These data indicate that both gravity and hydrostatic pressure act at the same point of the signal transduction chain leading to the induction of a polarity of cytoplasmic streaming and support the hypothesis that characean cells respond to gravity by sensing a gravity-induced pressure differential between the cell ends.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29663267','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29663267"><span>Local geology determines responses of stream producers and fungal decomposers to nutrient enrichment: A field experiment.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mykrä, Heikki; Sarremejane, Romain; Laamanen, Tiina; Karjalainen, Satu Maaria; Markkola, Annamari; Lehtinen, Sirkku; Lehosmaa, Kaisa; Muotka, Timo</p> <p>2018-04-16</p> <p>We examined how short-term (19 days) nutrient enrichment influences stream fungal and diatom communities, and rates of leaf decomposition and algal biomass accrual. We conducted a field experiment using slow-releasing nutrient pellets to increase nitrate (NO 3 -N) and phosphate (PO 4 -P) concentrations in a riffle section of six naturally acidic (naturally low pH due to catchment geology) and six circumneutral streams. Nutrient enrichment increased microbial decomposition rate on average by 14%, but the effect was significant only in naturally acidic streams. Nutrient enrichment also decreased richness and increased compositional variability of fungal communities in naturally acidic streams. Algal biomass increased in both stream types, but algal growth was overall very low. Diatom richness increased in response to nutrient addition by, but only in circumneutral streams. Our results suggest that primary producers and decomposers are differentially affected by nutrient enrichment and that their responses to excess nutrients are context dependent, with a potentially stronger response of detrital processes and fungal communities in naturally acidic streams than in less selective environments.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11540076','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11540076"><span>Hydrostatic pressure mimics gravitational pressure in characean cells.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Staves, M P; Wayne, R; Leopold, A C</p> <p>1992-01-01</p> <p>Hydrostatic pressure applied to one end of a horizontal Chara cell induces a polarity of cytoplasmic streaming, thus mimicking the effect of gravity. A positive hydrostatic pressure induces a more rapid streaming away from the applied pressure and a slower streaming toward the applied pressure. In contrast, a negative pressure induces a more rapid streaming toward and a slower streaming away from the applied pressure. Both the hydrostatic pressure-induced and gravity-induced polarity of cytoplasmic streaming respond identically to cell ligation, UV microbeam irradiation, external Ca2+ concentrations, osmotic pressure, neutral red, TEA Cl-, and the Ca2+ channel blockers nifedipine and LaCl3. In addition, hydrostatic pressure applied to the bottom of a vertically-oriented cell can abolish and even reverse the gravity-induced polarity of cytoplasmic streaming. These data indicate that both gravity and hydrostatic pressure act at the same point of the signal transduction chain leading to the induction of a polarity of cytoplasmic streaming and support the hypothesis that characean cells respond to gravity by sensing a gravity-induced pressure differential between the cell ends.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4472517','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4472517"><span>Divergent Macroparasite Infections in Parapatric Swiss Lake-Stream Pairs of Threespine Stickleback (Gasterosteus aculeatus)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Karvonen, Anssi; Lucek, Kay; Marques, David A.; Seehausen, Ole</p> <p>2015-01-01</p> <p>Spatial heterogeneity in diversity and intensity of parasitism is a typical feature of most host-parasite interactions, but understanding of the evolutionary implications of such variation is limited. One possible outcome of infection heterogeneities is parasite-mediated divergent selection between host populations, ecotypes or species which may facilitate the process of ecological speciation. However, very few studies have described infections in population-pairs along the speciation continuum from low to moderate or high degree of genetic differentiation that would address the possibility of parasite-mediated divergent selection in the early stages of the speciation process. Here we provide an example of divergent parasitism in freshwater fish ecotypes by examining macroparasite infections in threespine stickleback (Gasterosteus aculeatus) of four Swiss lake systems each harbouring parapatric lake-stream ecotype pairs. We demonstrate significant differences in infections within and between the pairs that are driven particularly by the parasite taxa transmitted to fish from benthic invertebrates. The magnitude of the differences tended to correlate positively with the extent of neutral genetic differentiation between the parapatric lake and stream populations of stickleback, whereas no such correlation was found among allopatric populations from similar or contrasting habitats. This suggests that genetic differentiation is unrelated to the magnitude of parasite infection contrasts when gene flow is constrained by geographical barriers while in the absence of physical barriers, genetic differentiation and the magnitude of differences in infections tend to be positively correlated. PMID:26086778</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26086778','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26086778"><span>Divergent Macroparasite Infections in Parapatric Swiss Lake-Stream Pairs of Threespine Stickleback (Gasterosteus aculeatus).</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Karvonen, Anssi; Lucek, Kay; Marques, David A; Seehausen, Ole</p> <p>2015-01-01</p> <p>Spatial heterogeneity in diversity and intensity of parasitism is a typical feature of most host-parasite interactions, but understanding of the evolutionary implications of such variation is limited. One possible outcome of infection heterogeneities is parasite-mediated divergent selection between host populations, ecotypes or species which may facilitate the process of ecological speciation. However, very few studies have described infections in population-pairs along the speciation continuum from low to moderate or high degree of genetic differentiation that would address the possibility of parasite-mediated divergent selection in the early stages of the speciation process. Here we provide an example of divergent parasitism in freshwater fish ecotypes by examining macroparasite infections in threespine stickleback (Gasterosteus aculeatus) of four Swiss lake systems each harbouring parapatric lake-stream ecotype pairs. We demonstrate significant differences in infections within and between the pairs that are driven particularly by the parasite taxa transmitted to fish from benthic invertebrates. The magnitude of the differences tended to correlate positively with the extent of neutral genetic differentiation between the parapatric lake and stream populations of stickleback, whereas no such correlation was found among allopatric populations from similar or contrasting habitats. This suggests that genetic differentiation is unrelated to the magnitude of parasite infection contrasts when gene flow is constrained by geographical barriers while in the absence of physical barriers, genetic differentiation and the magnitude of differences in infections tend to be positively correlated.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/869733','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/869733"><span>Pyrolysis of polystyrene - polyphenylene oxide to recover styrene and useful products</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Evans, Robert J.; Chum, Helena L.</p> <p>1995-01-01</p> <p>A process of using fast pyrolysis in a carrier gas to convert a polystyrene and polyphenylene oxide plastic waste to a given polystyrene and polyphenylene oxide prior to pyrolysis of other plastic components therein comprising: selecting a first temperature range to cause pyrolysis of given polystyrene and polyphenylene oxide and its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and a support and treating the feed stream with the catalyst to affect acid or base catalyzed reaction pathways to maximize yield or enhance separation of high value monomeric constituent of styrene from polystyrene and polyphenylene oxide in the first temperature range; differentially heating the feed stream at a heat rate within the first temperature range to provide differential pyrolysis for selective recovery of the high value monomeric constituent of styrene from polystyrene and polyphenylene oxide prior to pyrolysis of other plastic components; separating the high value monomer constituent of styrene; selecting a second higher temperature range to cause pyrolysis to a different derived high value product of polyphenylene oxide from the plastic waste and differentially heating the feed stream at the higher temperature range to cause pyrolysis of the plastic into a polyphenylene oxide derived product; and separating the different derived high value polyphenylene oxide product.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/869226','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/869226"><span>Controlled catalytic and thermal sequential pyrolysis and hydrolysis of mixed polymer waste streams to sequentially recover monomers or other high value products</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Evans, Robert J.; Chum, Helena L.</p> <p>1994-01-01</p> <p>A process of using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents, selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feedstream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/869578','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/869578"><span>Controlled catalytic and thermal sequential pyrolysis and hydrolysis of mixed polymer waste streams to sequentially recover monomers or other high value products</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Evans, Robert J.; Chum, Helena L.</p> <p>1994-01-01</p> <p>A process of using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents; selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feedstream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/868801','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/868801"><span>Controlled catalytic and thermal sequential pyrolysis and hydrolysis of mixed polymer waste streams to sequentially recover monomers or other high value products</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Evans, Robert J.; Chum, Helena L.</p> <p>1993-01-01</p> <p>A process of using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents; selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feedstream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/40117','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/40117"><span>Nutrient enrichment differentially affects body sizes of primary consumers and predators in a detritus-based stream</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>John M. Davis; Amy D. Rosemond; Sue L. Eggert; Wyatt F. Cross; J. Bruce Wallace</p> <p>2010-01-01</p> <p>We assessed how a 5-yr nutrient enrichment affected the responses of different size classes of primary consumers and predators in a detritus-based headwater stream. We hypothesized that alterations in detritus availability because of enrichment would decrease the abundance and biomass of large-bodied consumers. In contrast, we found that 2 yr of enrichment increased...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1415456','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1415456"><span>Temperature analysis with voltage-current time differential operation of electrochemical sensors</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Woo, Leta Yar-Li; Glass, Robert Scott; Fitzpatrick, Joseph Jay</p> <p></p> <p>A method for temperature analysis of a gas stream. The method includes identifying a temperature parameter of an affected waveform signal. The method also includes calculating a change in the temperature parameter by comparing the affected waveform signal with an original waveform signal. The method also includes generating a value from the calculated change which corresponds to the temperature of the gas stream.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=165487&keyword=steam&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=165487&keyword=steam&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>DOES FIELD DATA SHOW DOWNWARD MOBILIZATION OF DNAPL DURING THERMAL REMEDIATION?</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The question of will DNAPLs be mobilized downward during thermal remediation has been asked many times. Indeed, downward mobilization of DNAPLs during steam injection has been observed in the lab. The mechanism for this downward mobilization was the concentration of the contami...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=154347&keyword=steam&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=154347&keyword=steam&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>DOES FIELD DATA SHOW DOWNWARD MOBILIZATION OF DNAPL DURING THERMAL REMEDIATION? (ABSTRACT)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>The question of will DNAPLs be mobilized downward during thermal remediation has been asked many times. Indeed, downward mobilization of DNAPLs during steam injection has been observed in the lab. The mechanism for this downward mobilization was the concentration of the contami...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Geomo.276..144M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Geomo.276..144M"><span>Tectonic and lithological controls on fluvial landscape development in central-eastern Portugal: Insights from long profile tributary stream analyses</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Martins, António A.; Cabral, João; Cunha, Pedro P.; Stokes, Martin; Borges, José; Caldeira, Bento; Martins, A. Cardoso</p> <p>2017-01-01</p> <p>This study examines the long profiles of tributaries of the Tagus and Zêzere rivers in Portugal (West Iberia) in order to provide new insights into patterns, timing, and controls on drainage development during the Quaternary incision stage. The studied streams are incised into a relict culminant fluvial surface, abandoned at the beginning of the incision stage. The streams flow through a landscape with bedrock variations in lithology (mainly granites and metasediments) and faulted blocks with distinct uplift rates. The long profiles of the analyzed streams record an older transitory knickpoint/knickzone separating (1) an upstream relict graded profile, with lower steepness and higher concavity, that reflects a long period of quasi-equilibrium conditions reached after the beginning of the incision stage, and (2) a downstream rejuvenated long profile, with steeper gradient and lower concavity, particularly for the final reach, which is often convex. The rejuvenated reaches testify to the upstream propagation of several incision waves, interpreted as the response of each stream to increasing crustal uplift and prolonged periods of base-level lowering by the trunk drainages, coeval with low sea level conditions. The morphological configurations of the long profiles enabled spatial and relative temporal patterns of incisions to be quantified. The incision values of streams flowing on the Portuguese Central Range (PCR; ca. 380-150 m) are variable but generally higher than the incision values of streams flowing on the adjacent South Portugal Planation Surface (SPPS; ca. 220-110 m), corroborating differential uplift of the PCR relative to the SPPS. Owing to the fact that the relict graded profiles can be correlated with the Tagus River T1 terrace (1.1-0.9 My) present in the study area, incision rates can be estimated (1) for the streams located in the PCR, 0.38-0.15 m/ky and (2) for the streams flowing on the SPPS, 0.22-0.12 m/ky. The differential uplift inferred in the study area supports the neotectonic activity of the bordering faults, as proposed in previous studies based upon other geological evidence.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.9744S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.9744S"><span>Groundwater Recharge and Flow Regime revealed by multi-tracers approach in a headwater, North China Plain</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sakakibara, Koichi; Tsujimura, Maki; Song, Xianfang; Zhang, Jie</p> <p>2014-05-01</p> <p>Groundwater recharge is a crucial hydrological process for effective water management especially in arid/ semi-arid regions. However, the insufficient number of specific research regarding groundwater recharge process has been reported previously. Intensive field surveys were conducted during rainy season, mid dry season, and end of dry season, in order to clarify comprehensive groundwater recharge and flow regime of Wangkuai watershed in a headwater, which is a main recharge zone of North China Plain. The groundwater, spring, stream water and lake water were sampled, and inorganic solute constituents and stable isotopes of oxygen 18 and deuterium were determined on all water samples. Also the stream flow rate was observed. The solute ion concentrations and stable isotopic compositions show that the most water of this region can be characterized by Ca-HCO3 type and the main water source is precipitation which is affected by altitude effect of stable isotopes. In addition, the river and reservoir of the area seem to recharge the groundwater during rainy season, whereas interaction between surface water and groundwater does not become dominant gradually after the rainy season. The inversion analysis applied in Wangkuai watershed using simple mixing model represents an existing multi-flow systems which shows a distinctive tracer signal and flow rate. In summary, the groundwater recharged at different locations in the upper stream of Wangkuai reservoir flows downward to alluvial fan with a certain amount of mixing together, also the surface water recharges certainly the groundwater in alluvial plain in the rainy season.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3401901','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3401901"><span>Differential gene expression in migratory streams of cortical interneurons</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Antypa, Mary; Faux, Clare; Eichele, Gregor; Parnavelas, John G; Andrews, William D</p> <p>2011-01-01</p> <p>Cortical interneurons originate in the ganglionic eminences of the subpallium and migrate into the cortex in well-defined tangential streams. At the start of corticogenesis, two streams of migrating neurons are evident: a superficial one at the level of the preplate (PPL), and a deeper one at the level of the intermediate zone (IZ). Currently, little is known about the signalling mechanisms that regulate interneuron migration, and almost nothing is known about the molecules that may be involved in their choice of migratory stream. Here, we performed a microarray analysis, comparing the changes in gene expression between cells migrating in the PPL and those migrating in the IZ at embryonic day 13.5. This analysis identified genes, many of them novel, that were upregulated in one of the two streams. Moreover, polymerase chain reaction, in situ hybridization experiments and immunohistochemistry showed the expression of these genes in interneurons migrating within the PPL or IZ, suggesting that they play a role in their migration and choice of stream. PMID:22103416</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/17063','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/17063"><span>Does leaf chemistry differentially affect breakdown in tropical vs temperate streams? Importance of standardized analytical techniques to measure leaf chemistry</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Marcelo Ard& #243; n; Catherine M. Pringle; Susan L. Eggert</p> <p>2009-01-01</p> <p>Comparisons of the effects of leaf litter chemistry on leaf breakdown rates in tropical vs temperate streams are hindered by incompatibility among studies and across sites of analytical methods used to measure leaf chemistry. We used standardized analytical techniques to measure chemistry and breakdown rate of leaves from common riparian tree species at 2 sites, 1...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70168353','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70168353"><span>Population connectivity and genetic structure of burbot (Lota lota) populations in the Wind River Basin, Wyoming</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Underwood, Zachary E.; Mandeville, Elizabeth G.; Walters, Annika W.</p> <p>2016-01-01</p> <p>Burbot (Lota lota) occur in the Wind River Basin in central Wyoming, USA, at the southwestern extreme of the species’ native range in North America. The most stable and successful of these populations occur in six glacially carved mountain lakes on three different tributary streams and one large main stem impoundment (Boysen Reservoir) downstream from the tributary populations. Burbot are rarely found in connecting streams and rivers, which are relatively small and high gradient, with a variety of potential barriers to upstream movement of fish. We used high-throughput genomic sequence data for 11,197 SNPs to characterize the genetic diversity, population structure, and connectivity among burbot populations on the Wind River system. Fish from Boysen Reservoir and lower basin tributary populations were genetically differentiated from those in the upper basin tributary populations. In addition, fish within the same tributary streams fell within the same genetic clusters, suggesting there is movement of fish between lakes on the same tributaries but that populations within each tributary system are isolated and genetically distinct from other populations. Observed genetic differentiation corresponded to natural and anthropogenic barriers, highlighting the importance of barriers to fish population connectivity and gene flow in human-altered linked lake-stream habitats.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29621414','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29621414"><span>Magnetic field direction differentially impacts the growth of different cell types.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tian, Xiaofei; Wang, Dongmei; Zha, Meng; Yang, Xingxing; Ji, Xinmiao; Zhang, Lei; Zhang, Xin</p> <p>2018-04-05</p> <p>Magnetic resonance imaging (MRI) machines have horizontal or upright static magnetic field (SMF) of 0.1-3 T (Tesla) at sites of patients and operators, but the biological effects of these SMFs still remain elusive. We examined 12 different cell lines, including 5 human solid tumor cell lines, 2 human leukemia cell lines and 4 human non-cancer cell lines, as well as the Chinese hamster ovary cell line. Permanent magnets were used to provide 0.2-1 T SMFs with different magnetic field directions. We found that an upward magnetic field of 0.2-1 T could effectively reduce the cell numbers of all human solid tumor cell lines we tested, but a downward magnetic field mostly had no statistically significant effect. However, the leukemia cells in suspension, which do not have shape-induced anisotropy, were inhibited by both upward and downward magnetic fields. In contrast, the cell numbers of most non-cancer cells were not affected by magnetic fields of all directions. Moreover, the upward magnetic field inhibited GIST-T1 tumor growth in nude mice by 19.3% (p < 0.05) while the downward magnetic field did not produce significant effect. In conclusion, although still lack of mechanistical insights, our results show that different magnetic field directions produce divergent effects on cancer cell numbers as well as tumor growth in mice. This not only verified the safety of SMF exposure related to current MRI machines but also revealed the possible antitumor potential of magnetic field with an upward direction.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27841448','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27841448"><span>"Ethnicity moderates the outcomes of self-enhancement and self-improvement themes in expressive writing": Correction to Tsai et al. (2015).</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p></p> <p>2017-01-01</p> <p>Reports an error in "Ethnicity moderates the outcomes of self-enhancement and self-improvement themes in expressive writing" by William Tsai, Anna S. Lau, Andrea N. Niles, Jordan Coello, Matthew D. Lieberman, Ahra C. Ko, Christopher Hur and Annette L. Stanton ( Cultural Diversity and Ethnic Minority Psychology , 2015[Oct], Vol 21[4], 584-592). In this article, there were three errors in the Results section. Each are described in the erratum alongside the correct results. The interpretations of the findings remain the same. (The following abstract of the original article appeared in record 2014-32908-001.) The current study examined whether writing content related to self-enhancing (viz., downward social comparison and situational attributions) and self-improving (viz., upward social comparison and persistence) motivations were differentially related to expressive writing outcomes among 17 Asian American and 17 European American participants. Content analysis of the essays revealed no significant cultural group differences in the likelihood of engaging in self-enhancing versus self-improving reflections on negative personal experiences. However, cultural group differences were apparent in the relation between self-motivation processes and changes in anxiety and depressive symptoms at 3-month follow-up. Among European Americans, writing that reflected downward social comparison predicted positive outcomes, whereas persistence writing themes were related to poorer outcomes. For Asian Americans, writing about persistence was related to positive outcomes, whereas downward social comparison and situational attributions predicted poorer outcomes. Findings provide evidence suggesting culturally distinct mechanisms for the effects of expressive disclosure. (PsycINFO Database Record (c) 2017 APA, all rights reserved).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/of/1982/0994/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/1982/0994/report.pdf"><span>Shallow subsurface temperatures and some estimates of heat flow from the Colorado Plateau of northeastern Arizona</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Sass, J.H.; Stone, Claudia; Bills, D.J.</p> <p>1982-01-01</p> <p>Temperature data to depths of a few hundred meters were obtained from 29 wells in northeastern Arizona; 12 in the region surrounding the San Francisco Volcanic Field, 8 in the Black Mesa area, and 9 in the south-central Colorado Plateau which includes the White Mountains. Although there was evidence for local hydrologic disturbances in many temperature profiles, most wells provided an estimate of the conductive thermal gradient at the site. A few thermal conductivities were measured and were combined with published regional averages for the north-central part of the Colorado Plateau to produce crude estimates of regional heat flux. None of the wells was accessible below the regional aquifers. To these depths, heat flow in the area of the San Francisco Volcanic Field appears to be controlled primarily by regional lateral water movement having a significant downward vertical component of velocity. The mean heat flow of 27?5 mW^-2 is only a third to a quarter of what we would expect in this tectonic setting. The heat that is being carried laterally and downward probably is being discharged at low enthalpy and low elevation in springs and streams of the Colorado Plateau and Mogollon Rim. In the vicinity of Black Mesa, heat-flow averages about 60 mW^-2, characteristic of the 'cool interior' of the Colorado Plateau. North of the White Mountain Volcanic Field, the average heat flow is about 95 mW^-2.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70029498','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70029498"><span>Trends in hydrophobic organic contaminants in urban and reference lake sediments across the United States, 1970-2001</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Van Metre, P.C.; Mahler, B.J.</p> <p>2005-01-01</p> <p>A shift in national policy toward stronger environmental protection began in the United States in about 1970. Conversely, urban land use, population, energy consumption, and vehicle use have increased greatly since then. To assess the effects of these changes on water quality, the U.S. Geological Survey used sediment cores to reconstruct water-quality histories for38 urban and reference lakes across the United States. Cores were age-dated, and concentration profiles of polycyclic aromatic hydrocarbons (PAHs) and chlorinated hydrocarbons were tested statistically. Significant trends in total DDT, p,p???-DDE, and total PCBs were all downward. Trends in chlordane were split evenly between upward and downward, and trends in PAHs were mostly upward. Significant trends did not occur in about one-half of cases tested. Concentrations of p,p???-DDE, p,p???-DDD, and PCBs were about one-half as likely to exceed the probable effect concentration (PEC), a sediment quality guideline, in sediments deposited in the 1990s as in 1965-1975, whereas PAHs were twice as likely to exceed the PEC in the more recently deposited sediments. Concentrations of all contaminants evaluated correlated strongly with urban land use. Upward trends in PAH concentrations, the strong association of PAH with urban settings, and rapid urbanization occurring in the United States suggest that PAHs could surpass chlorinated hydrocarbons in the threat they pose to aquatic biota in urban streams and lakes.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014OcSci..10...29S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014OcSci..10...29S"><span>Observed decline of the Atlantic meridional overturning circulation 2004-2012</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Smeed, D. A.; McCarthy, G. D.; Cunningham, S. A.; Frajka-Williams, E.; Rayner, D.; Johns, W. E.; Meinen, C. S.; Baringer, M. O.; Moat, B. I.; Duchez, A.; Bryden, H. L.</p> <p>2014-02-01</p> <p>The Atlantic meridional overturning circulation (AMOC) has been observed continuously at 26° N since April 2004. The AMOC and its component parts are monitored by combining a transatlantic array of moored instruments with submarine-cable-based measurements of the Gulf Stream and satellite derived Ekman transport. The time series has recently been extended to October 2012 and the results show a downward trend since 2004. From April 2008 to March 2012, the AMOC was an average of 2.7 Sv (1 Sv = 106 m3 s-1) weaker than in the first four years of observation (95% confidence that the reduction is 0.3 Sv or more). Ekman transport reduced by about 0.2 Sv and the Gulf Stream by 0.5 Sv but most of the change (2.0 Sv) is due to the mid-ocean geostrophic flow. The change of the mid-ocean geostrophic flow represents a strengthening of the southward flow above the thermocline. The increased southward flow of warm waters is balanced by a decrease in the southward flow of lower North Atlantic deep water below 3000 m. The transport of lower North Atlantic deep water slowed by 7% per year (95% confidence that the rate of slowing is greater than 2.5% per year).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA.....5928J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA.....5928J"><span>A Model Simulation of Mountain Waves in the Middle Atmosphere and Its Comparison with Microwave Limb Sounder Observations</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jiang, J. H.; Eckermann, S. D.; Wu, D. L.; Ma, J.; Wang, D. Y.</p> <p>2003-04-01</p> <p>Topography-related wintertime stratospheric gravity waves in both Northern and Southern Hemisphere are simulated using the Naval Research Laboratory Mountain Wave Forecast Model (MWFM). The results agree well with the observations from Upper Atmospheric Research Satellite Microwave Limb Sounder (MLS). Both the MWFM simulation and MLS observations found strong wave activities over the high-latitude mountain ridges of Scandinavia, Central Eurasia, Alaska, southern Greenland in Northern Hemisphere, and Andes, New Zealand, Antarctic rim in Southern Hemisphere. These mountain waves are dominated by wave modes with downward phase progression and horizontal phase velocities opposite to the stratospheric jet-stream. Agreements of minor wave activities are also found at low- to mid-latitudes over Zagros Mountains of Middle East, Colorado Rocky Mountains, Appalachians, and Sierra Madres of Central America. Some differences between the MWFM results and MLS data are explained by different horizontal resolution between the model and observation, and the fact that MLS may also see the non-orographic wave sources, such as mesoscale storms and jet-stream instabilities. The findings from this model-measurement comparison study demonstrate that satellite instruments such as MLS can provide global data needed to characterize mountain wave sources, their inter-annual variations, and to improve gravity wave parameterizations in global climate and forecast models.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JGRF..117.2037G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JGRF..117.2037G"><span>Investigation of land ice-ocean interaction with a fully coupled ice-ocean model: 1. Model description and behavior</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Goldberg, D. N.; Little, C. M.; Sergienko, O. V.; Gnanadesikan, A.; Hallberg, R.; Oppenheimer, M.</p> <p>2012-06-01</p> <p>Antarctic ice shelves interact closely with the ocean cavities beneath them, with ice shelf geometry influencing ocean cavity circulation, and heat from the ocean driving changes in the ice shelves, as well as the grounded ice streams that feed them. We present a new coupled model of an ice stream-ice shelf-ocean system that is used to study this interaction. The model is capable of representing a moving grounding line and dynamically responding ocean circulation within the ice shelf cavity. Idealized experiments designed to investigate the response of the coupled system to instantaneous increases in ocean temperature show ice-ocean system responses on multiple timescales. Melt rates and ice shelf basal slopes near the grounding line adjust in 1-2 years, and downstream advection of the resulting ice shelf thinning takes place on decadal timescales. Retreat of the grounding line and adjustment of grounded ice takes place on a much longer timescale, and the system takes several centuries to reach a new steady state. During this slow retreat, and in the absence of either an upward-or downward-sloping bed or long-term trends in ocean heat content, the ice shelf and melt rates maintain a characteristic pattern relative to the grounding line.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28523983','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28523983"><span>Ear Advantage for Musical Location and Relative Pitch: Effects of Musical Training and Attention.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hutchison, Joanna L; Hubbard, Timothy L; Hubbard, Nicholas A; Rypma, Bart</p> <p>2017-06-01</p> <p>Trained musicians have been found to exhibit a right-ear advantage for high tones and a left-ear advantage for low tones. We investigated whether this right/high, left/low pattern of musical processing advantage exists in listeners who had varying levels of musical experience, and whether such a pattern might be modulated by attentional strategy. A dichotic listening paradigm was used in which different melodic sequences were presented to each ear, and listeners attended to (a) the left ear or the right ear or (b) the higher pitched tones or the lower pitched tones. Listeners judged whether tone-to-tone transitions within each melodic sequence moved upward or downward in pitch. Only musically experienced listeners could adequately judge the direction of successive pitch transitions when attending to a specific ear; however, all listeners could judge the direction of successive pitch transitions within a high-tone stream or a low-tone stream. Overall, listeners exhibited greater accuracy when attending to relatively higher pitches, but there was no evidence to support a right/high, left/low bias. Results were consistent with effects of attentional strategy rather than an ear advantage for high or low tones. Implications for a potential performer/audience paradox in listening space are considered.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70017280','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70017280"><span>Mechanisms of iron photoreduction in a metal-rich, acidic stream (St. Kevin Gulch, Colorado, U.S.A.)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Kimball, B.A.; McKnight, Diane M.; Wetherbee, G.A.; Harnish, R.A.</p> <p>1992-01-01</p> <p>Iron photoreduction in metal-rich, acidic streams affected by mine drainage accounts for some of the variability in metal chemistry of such streams, producing diel variations in Fe(II). Differentiation of the mechanisms of the Fe photoreduction reaction by a series of in-stream experiments at St. Kevin Gulch, Colorado, indicates that a homogeneous, solution-phase reaction can occur in the absence of suspended particulate Fe and bacteria, and the rate of reaction is increased by the presence of Fe colloids in the stream water. In-stream Fe photoreduction is limited during the diel cycle by the available Fe(III) in the water column and streambed. The quantum yield of Fe(II) was reproducible in diel measurements: the quantum yield, in mol E-1 (from 300 to 400 nm) was 1.4 ?? 10-3 in 1986, 0.8 ?? 10-3 in 1988 and 1.2 ?? 10-3 in 1989, at the same location and under similar streamflow and stream-chemistry conditions. In a photolysis control experiment, there was no detectable production of Fe(II) above background concentrations in stream-water samples that were experimentally excluded from sunlight. ?? 1992.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUSM.B33E..15C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUSM.B33E..15C"><span>Soil Microbial Community Contribution to Small Headwater Stream Metabolism.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Clapcott, J. E.; Gooderham, J. P.; Barmuta, L. A.; Davies, P. E.</p> <p>2005-05-01</p> <p>The temporal dynamics of sediment respiration were examined in seven small headwater streams in forested catchments in 2004. A strong seasonal response was observed with higher respiration rates in depositional zones than in gravel runs. The data were also examined in the context of proportional habitat distributions that highlighted the importance of high flow events in shaping whole stream metabolic budgets. This study specifically examines the question of terrestrial soil respiration contribution to whole stream metabolism by the controlled inundation of terrestrial soils. The experiment included six experimentally inundated terrestrial zones, six terrestrial controls, and six in-stream depositional zones. Sediment bacterial respiration was measured using 14C leucine incorporation and cotton strip bioassays were also employed to provide an indicative measure of sediment microbial activity. Despite high variability and exhibiting significantly lower bacterial activity than in-stream sediments, modelling using flow data and habitat mapping illustrated the important contribution of terrestrial soil respiration to the whole stream metabolic budgets of small headwater streams. In addition, microbial community composition examined using phospholipid fatty acid analysis clearly differentiated between terrestrial and aquatic communities. Freshly inundated terrestrial communities remained similar to un-inundated controls after 28 days.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2010/5189/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2010/5189/"><span>Effects of groundwater levels and headwater wetlands on streamflow in the Charlie Creek basin, Peace River watershed, west-central Florida</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Lee, T.M.; Sacks, L.A.; Hughes, J.D.</p> <p>2010-01-01</p> <p>The Charlie Creek basin was studied from April 2004 to December 2005 to better understand how groundwater levels in the underlying aquifers and storage and overflow of water from headwater wetlands preserve the streamflows exiting this least-developed tributary basin of the Peace River watershed. The hydrogeologic framework, physical characteristics, and streamflow were described and quantified for five subbasins of the 330-square mile Charlie Creek basin, allowing the contribution of its headwaters area and tributary subbasins to be separately quantified. A MIKE SHE model simulation of the integrated surface-water and groundwater flow processes in the basin was used to simulate daily streamflow observed over 21 months in 2004 and 2005 at five streamflow stations, and to quantify the monthly and annual water budgets for the five subbasins including the changing amount of water stored in wetlands. Groundwater heads were mapped in Zone 2 of the intermediate aquifer system and in the Upper Floridan aquifer, and were used to interpret the location of artesian head conditions in the Charlie Creek basin and its relation to streamflow. Artesian conditions in the intermediate aquifer system induce upward groundwater flow into the surficial aquifer and help sustain base flow which supplies about two-thirds of the streamflow from the Charlie Creek basin. Seepage measurements confirmed seepage inflow to Charlie Creek during the study period. The upper half of the basin, comprised largely of the Upper Charlie Creek subbasin, has lower runoff potential than the lower basin, more storage of runoff in wetlands, and periodically generates no streamflow. Artesian head conditions in the intermediate aquifer system were widespread in the upper half of the Charlie Creek basin, preventing downward leakage from expansive areas of wetlands and enabling them to act as headwaters to Charlie Creek once their storage requirements were met. Currently, the dynamic balance between wetland storage, rainfall-runoff processes, and groundwater-level differences in the upper basin allow it to generate approximately half of the streamflow from the Charlie Creek basin. Therefore, future development in the upper basin that would alter the hydraulic connectivity of wetlands during high flow conditions or expand recharging groundwater conditions could substantially affect streamflow in Charlie Creek. LIDAR (Light detection and ranging) based topographic maps and integrated modeling results were used to quantify the water stored in wetlands and other topographic depressions, and to describe the network of shallow stream channels connecting wetlands to Charlie Creek and its tributaries over distances of several thousand feet. Peak flows at all but one streamflow station were underpredicted in MIKE SHE simulations, possibly because the hydraulics of surface channels connecting wetlands to stream channels were not explicitly simulated in the model. Explicitly simulating the smaller channels connecting wetlands and stream channels should improve the ability of future watershed models to simulate peak flows in streams with headwater wetlands. The runoff potential was greater in the lower half of the Charlie Creek basin than in the upper half, and the streambed of Charlie Creek had greater potential to both directly gain streamflow from groundwater and lose streamflow to groundwater. Charlie Creek is more incised into the surficial aquifer in the lower basin than in the upper basin, and the streambed intersects the top of the intermediate aquifer system at two known locations. Groundwater levels in the intermediate aquifer system varied widely in the lower half of the basin from artesian conditions inducing upward flow toward the surficial aquifer and streams, to recharging conditions allowing downward flow and stream leakage. Recharge areas were greatest in May 2004 when rainfall was at a seasonal low and irrigation pumping was at a seasonal high. Recharge conditions</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20149085','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20149085"><span>Scale-dependent genetic structure of the Idaho giant salamander (Dicamptodon aterrimus) in stream networks.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mullen, Lindy B; Arthur Woods, H; Schwartz, Michael K; Sepulveda, Adam J; Lowe, Winsor H</p> <p>2010-03-01</p> <p>The network architecture of streams and rivers constrains evolutionary, demographic and ecological processes of freshwater organisms. This consistent architecture also makes stream networks useful for testing general models of population genetic structure and the scaling of gene flow. We examined genetic structure and gene flow in the facultatively paedomorphic Idaho giant salamander, Dicamptodon aterrimus, in stream networks of Idaho and Montana, USA. We used microsatellite data to test population structure models by (i) examining hierarchical partitioning of genetic variation in stream networks; and (ii) testing for genetic isolation by distance along stream corridors vs. overland pathways. Replicated sampling of streams within catchments within three river basins revealed that hierarchical scale had strong effects on genetic structure and gene flow. amova identified significant structure at all hierarchical scales (among streams, among catchments, among basins), but divergence among catchments had the greatest structural influence. Isolation by distance was detected within catchments, and in-stream distance was a strong predictor of genetic divergence. Patterns of genetic divergence suggest that differentiation among streams within catchments was driven by limited migration, consistent with a stream hierarchy model of population structure. However, there was no evidence of migration among catchments within basins, or among basins, indicating that gene flow only counters the effects of genetic drift at smaller scales (within rather than among catchments). These results show the strong influence of stream networks on population structure and genetic divergence of a salamander, with contrasting effects at different hierarchical scales.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70035367','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70035367"><span>Hierarchical spatial structure of stream fish colonization and extinction</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hitt, N.P.; Roberts, J.H.</p> <p>2012-01-01</p> <p>Spatial variation in extinction and colonization is expected to influence community composition over time. In stream fish communities, local species richness (alpha diversity) and species turnover (beta diversity) are thought to be regulated by high extinction rates in headwater streams and high colonization rates in downstream areas. We evaluated the spatiotemporal structure of fish communities in streams originally surveyed by Burton and Odum 1945 (Ecology 26: 182-194) in Virginia, USA and explored the effects of species traits on extinction and colonization dynamics. We documented dramatic changes in fish community structure at both the site and stream scales. Of the 34 fish species observed, 20 (59%) were present in both time periods, but 11 (32%) colonized the study area and three (9%) were extirpated over time. Within streams, alpha diversity increased in two of three streams but beta diversity decreased dramatically in all streams due to fish community homogenization caused by colonization of common species and extirpation of rare species. Among streams, however, fish communities differentiated over time. Regression trees indicated that reproductive life-history traits such as spawning mound construction, associations with mound-building species, and high fecundity were important predictors of species persistence or colonization. Conversely, native fishes not associated with mound-building exhibited the highest rates of extirpation from streams. Our results demonstrate that stream fish colonization and extinction dynamics exhibit hierarchical spatial structure and suggest that mound-building fishes serve as keystone species for colonization of headwater streams.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70025195','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70025195"><span>Designing mark-recapture studies to reduce effects of distance weighting on movement distance distributions of stream fishes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Albanese, B.; Angermeier, P.L.; Gowan, C.</p> <p>2003-01-01</p> <p>Mark-recapture studies generate biased, or distance-weighted, movement data because short distances are sampled more frequently than long distances. Using models and field data, we determined how study design affects distance weighting and the movement distributions of stream fishes. We first modeled distance weighting as a function of recapture section length in an unbranching stream. The addition of an unsampled tributary to one of these models substantially increased distance weighting by decreasing the percentage of upstream distances that were sampled. Similarly, the presence of multiple tributaries in the field study resulted in severe bias. However, increasing recapture section length strongly affected distance weighting in both the model and the field study, producing a zone where the number of fish moving could be estimated with little bias. Subsampled data from the field study indicated that longer median (three of three species) and maximum distances (two of three species) can be detected by increasing the length of the recapture section. The effect was extreme for bluehead chub Nocomis leptocephalus, a highly mobile species, which exhibited a longer median distance (133 m versus 60 m), a longer maximum distance (1,144 m versus 708 m), and a distance distribution that differed in shape when the full (4,123-m recapture section) and subsampled (1,978-m recapture section) data sets were compared. Correction factors that adjust the observed number of movements to undersampled distances upwards and those to oversampled distances downwards could not mitigate the distance weighting imposed by the shorter recapture section. Future studies should identify the spatial scale over which movements can be accurately measured before data are collected. Increasing recapture section length a priori is far superior to using post hoc correction factors to reduce the influence of distance weighting on observed distributions. Implementing these strategies will be especially important in stream networks where fish can follow multiple pathways out of the recapture section.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhFl...29k2103F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhFl...29k2103F"><span>On shapes and motion of an elongated bubble in downward liquid pipe flow</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fershtman, A.; Babin, V.; Barnea, D.; Shemer, L.</p> <p>2017-11-01</p> <p>In stagnant liquid, or in a steady upward liquid pipe flow, an elongated (Taylor) bubble has a symmetric shape. The translational velocity of the bubble is determined by buoyancy and the liquid velocity profile ahead of it. In downward flow, however, the symmetry of the bubble nose can be lost. Taylor bubble motion in downward flow is important in numerous applications such as chemical plants and cooling systems that often contain countercurrent gas-liquid flow. In the present study, the relation between the Taylor bubble shape and its translational velocity is investigated experimentally in a vertical pipe for various downward liquid flow rates. At higher downward velocities, the bubble may be forced by the background flow to propagate downward against buoyancy. In order to include those cases as well in our experimental analysis, the bubbles were initially injected into stagnant liquid, whereas the downward flow was initiated at a later stage. This experimental procedure allowed us to identify three distinct modes of translational velocities for a given downward background liquid flow; each velocity corresponds to a different bubble shape. Hydrodynamic mechanisms that govern the transition between the modes observed in the present study are discussed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/7187249','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/7187249"><span>Controlled catalytic and thermal sequential pyrolysis and hydrolysis of mixed polymer waste streams to sequentially recover monomers or other high value products</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Evans, R.J.; Chum, H.L.</p> <p>1994-10-25</p> <p>A process of using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents; selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feedstream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent. 83 figs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/5123316','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/5123316"><span>Controlled catalytic and thermal sequential pyrolysis and hydrolysis of mixed polymer waste streams to sequentially recover monomers or other high value products</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Evans, R.J.; Chum, H.L.</p> <p>1994-04-05</p> <p>A process is described for using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents, selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feedstream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent. 87 figures.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/867475','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/867475"><span>Surface mount component jig</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Kronberg, James W.</p> <p>1990-08-07</p> <p>A device for bending and trimming the pins of a dual-inline-package component and the like for surface mounting rather than through mounting to a circuit board comprises, in a first part, in pin cutter astride a holder having a recess for holding the component, a first spring therebetween, and, in a second part, two flat members pivotally interconnected by a hinge and urged to an upward peaked position from a downward peaked position by a second spring. As a downward force is applied to the pin cutter it urges the holder downward, assisted by the first spring and a pair of ridges riding on shoulders of the holder, to carry the component against the upward peaked flat members which guide the pins outwardly. As the holder continues downwardly, the flat members pivot to the downward peaked position bending the pins upwardly against the sides of the holder. When the downward movement is met with sufficient resistance, the ridges of the pin cutter ride over the holder's shoulders to continue downward to cut any excess length of pin.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004PhBio...1..173K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004PhBio...1..173K"><span>Role of streams in myxobacteria aggregate formation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kiskowski, Maria A.; Jiang, Yi; Alber, Mark S.</p> <p>2004-10-01</p> <p>Cell contact, movement and directionality are important factors in biological development (morphogenesis), and myxobacteria are a model system for studying cell-cell interaction and cell organization preceding differentiation. When starved, thousands of myxobacteria cells align, stream and form aggregates which later develop into round, non-motile spores. Canonically, cell aggregation has been attributed to attractive chemotaxis, a long range interaction, but there is growing evidence that myxobacteria organization depends on contact-mediated cell-cell communication. We present a discrete stochastic model based on contact-mediated signaling that suggests an explanation for the initialization of early aggregates, aggregation dynamics and final aggregate distribution. Our model qualitatively reproduces the unique structures of myxobacteria aggregates and detailed stages which occur during myxobacteria aggregation: first, aggregates initialize in random positions and cells join aggregates by random walk; second, cells redistribute by moving within transient streams connecting aggregates. Streams play a critical role in final aggregate size distribution by redistributing cells among fewer, larger aggregates. The mechanism by which streams redistribute cells depends on aggregate sizes and is enhanced by noise. Our model predicts that with increased internal noise, more streams would form and streams would last longer. Simulation results suggest a series of new experiments.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUSMNB41E..01V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUSMNB41E..01V"><span>Theory Can Help Structure Regression Models for Projecting Stream Conditions Under Alternative Land Use Scenarios</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>van Sickle, J.; Baker, J.; Herlihy, A.</p> <p>2005-05-01</p> <p>We built multiple regression models for Emphemeroptera/ Plecoptera/ Tricoptera (EPT) taxon richness and other indicators of biological condition in streams of the Willamette River Basin, Oregon, USA. The models were used to project the changes in condition that would be expected in all 2-4th order streams of the 30000 sq km basin under alternative scenarios of future land use. In formulating the models, we invoked the theory of limiting factors to express the interactive effects of stream power and watershed land use on EPT richness. The resulting models were parsimonious, and they fit the data in our wedge-shaped scatterplots slightly better than did a naive additive-effects model. Just as theory helped formulate our regression models, the models in turn helped us identify a new research need for the Basin's streams. Our future scenarios project that conversions of agricultural to urban uses may dominate landscape dynamics in the basin over the next 50 years. But our models could not detect any difference between the effects of agricultural and urban development in watersheds on stream biota. This result points to an increased need for understanding how agricultural and urban land uses in the Basin differentially influence stream ecosystems.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20462900','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20462900"><span>Upside-down spiders build upside-down orb webs: web asymmetry, spider orientation and running speed in Cyclosa.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nakata, Kensuke; Zschokke, Samuel</p> <p>2010-10-07</p> <p>Almost all spiders building vertical orb webs face downwards when sitting on the hubs of their webs, and their webs exhibit an up-down size asymmetry, with the lower part of the capture area being larger than the upper. However, spiders of the genus Cyclosa, which all build vertical orb webs, exhibit inter- and intraspecific variation in orientation. In particular, Cyclosa ginnaga and C. argenteoalba always face upwards, and C. octotuberculata always face downwards, whereas some C. confusa face upwards and others face downwards or even sideways. These spiders provide a unique opportunity to examine why most spiders face downwards and have asymmetrical webs. We found that upward-facing spiders had upside-down webs with larger upper parts, downward-facing spiders had normal webs with larger lower parts and sideways-facing spiders had more symmetrical webs. Downward-facing C. confusa spiders were larger than upward- and sideways-facing individuals. We also found that during prey attacks, downward-facing spiders ran significantly faster downwards than upwards, which was not the case in upward-facing spiders. These results suggest that the spider's orientation at the hub and web asymmetry enhance its foraging efficiency by minimizing the time to reach prey trapped in the web.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2982030','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2982030"><span>Upside-down spiders build upside-down orb webs: web asymmetry, spider orientation and running speed in Cyclosa</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Nakata, Kensuke; Zschokke, Samuel</p> <p>2010-01-01</p> <p>Almost all spiders building vertical orb webs face downwards when sitting on the hubs of their webs, and their webs exhibit an up–down size asymmetry, with the lower part of the capture area being larger than the upper. However, spiders of the genus Cyclosa, which all build vertical orb webs, exhibit inter- and intraspecific variation in orientation. In particular, Cyclosa ginnaga and C. argenteoalba always face upwards, and C. octotuberculata always face downwards, whereas some C. confusa face upwards and others face downwards or even sideways. These spiders provide a unique opportunity to examine why most spiders face downwards and have asymmetrical webs. We found that upward-facing spiders had upside-down webs with larger upper parts, downward-facing spiders had normal webs with larger lower parts and sideways-facing spiders had more symmetrical webs. Downward-facing C. confusa spiders were larger than upward- and sideways-facing individuals. We also found that during prey attacks, downward-facing spiders ran significantly faster downwards than upwards, which was not the case in upward-facing spiders. These results suggest that the spider's orientation at the hub and web asymmetry enhance its foraging efficiency by minimizing the time to reach prey trapped in the web. PMID:20462900</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4611509','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4611509"><span>Altitudinal patterns of diversity and functional traits of metabolically active microorganisms in stream biofilms</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wilhelm, Linda; Besemer, Katharina; Fragner, Lena; Peter, Hannes; Weckwerth, Wolfram; Battin, Tom J</p> <p>2015-01-01</p> <p>Resources structure ecological communities and potentially link biodiversity to energy flow. It is commonly believed that functional traits (generalists versus specialists) involved in the exploitation of resources depend on resource availability and environmental fluctuations. The longitudinal nature of stream ecosystems provides changing resources to stream biota with yet unknown effects on microbial functional traits and community structure. We investigated the impact of autochthonous (algal extract) and allochthonous (spruce extract) resources, as they change along alpine streams from above to below the treeline, on microbial diversity, community composition and functions of benthic biofilms. Combining bromodeoxyuridine labelling and 454 pyrosequencing, we showed that diversity was lower upstream than downstream of the treeline and that community composition changed along the altitudinal gradient. We also found that, especially for allochthonous resources, specialisation by biofilm bacteria increased along that same gradient. Our results suggest that in streams below the treeline biofilm diversity, specialisation and functioning are associated with increasing niche differentiation as potentially modulated by divers allochthonous and autochthonous constituents contributing to resources. These findings expand our current understanding on biofilm structure and function in alpine streams. PMID:25978543</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29385651','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29385651"><span>Atlantic salmon Salmo salar in the chalk streams of England are genetically unique.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ikediashi, C; Paris, J R; King, R A; Beaumont, W R C; Ibbotson, A; Stevens, J R</p> <p>2018-03-01</p> <p>Recent research has identified genetic groups of Atlantic salmon Salmo salar that show association with geological and environmental boundaries. This study focuses on one particular subgroup of the species inhabiting the chalk streams of southern England, U.K. These fish are genetically distinct from other British and European S. salar populations and have previously demonstrated markedly low admixture with populations in neighbouring regions. The genetic population structure of S. salar occupying five chalk streams was explored using 16 microsatellite loci. The analysis provides evidence of the genetic distinctiveness of chalk-stream S. salar in southern England, in comparison with populations from non-chalk regions elsewhere in western Europe. Little genetic differentiation exists between the chalk-stream populations and a pattern of isolation by distance was evident. Furthermore, evidence of temporal stability of S. salar populations across the five chalk streams was found. This work provides new insights into the temporal stability and lack of genetic population sub-structuring within a unique component of the species' range of S. salar. © 2018 The Fisheries Society of the British Isles.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29017124','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29017124"><span>Shifts of radiocesium vertical profiles in sediments and their modelling in Japanese lakes.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fukushima, Takehiko; Komatsu, Eiji; Arai, Hiroyuki; Kamiya, Koichi; Onda, Yuichi</p> <p>2018-02-15</p> <p>Vertical profiles of radiocesium concentrations were measured in sediment cores collected at various times after the 2011 Fukushima nuclear accident in five Japanese lakes (Hinuma, Kasumigaura, Kitaura, Onogawa and Sohara) with different morphological and trophic characteristics in order to investigate the sedimentation-diffusion processes. In lakes where sediments had high porosities and experienced considerable wave action due to shallowness, we observed rapid penetration of radiocesium to a certain depth just after the accident, followed by downward movement of the peak depths. In contrast, gradual downward transfers of distinct peaks were found in other types of lakes. A one-dimensional differential sediment model with water-sediments interaction processes was constructed to describe the vertical shift of radiocesium profiles. Our proposed submodels relating to the length scales of the mixing using wind-induced stress and porosity of sediments were constructed based on one measurement of the vertical distribution of radiocesium in three lakes (Hinuma, Kasumigaura and Sohara). This model was then validated using samples from those lakes in different years, as well as from two other lakes. Good agreement was obtained. We discuss our findings, the limits of model application, and future research targets. Copyright © 2017 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70179632','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70179632"><span>Population size, survival, growth, and movements of Rana sierrae</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Fellers, Gary M.; Kleeman, Patrick M.; Miller, David A. W.; Halstead, Brian J.; Link, William</p> <p>2013-01-01</p> <p>Based on 2431 captures of 757 individual frogs over a 9-yr period, we found that the population of R. sierrae in one meadow–stream complex in Yosemite National Park ranged from an estimated 45 to 115 adult frogs. Rana sierrae at our relatively low elevation site (2200 m) grew at a fast rate (K = 0.73–0.78), had high overwintering survival rates (44.6–95%), lived a long time (up to 16 yr), and tended to be fairly sedentary during the summer (100% minimum convex polygon annual home ranges of 139 m2) but had low year-to-year site fidelity. Even though the amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) has been present in the population for at least 13 yr, there was no clear downward trend as might be expected from reports of R. sierrae population declines associated with Bd or from reports of widespread population decline of R. sierrae throughout its range.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/ctwrb/0008/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/ctwrb/0008/report.pdf"><span>Water resources inventory of Connecticut Part 1: Quinebaug River basin</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Randall, Allan D.; Thomas, Mendall P.; Thomas, Chester E.; Baker, John A.</p> <p>1966-01-01</p> <p>The Quinebaug River basin is blessed with a relatively abundant supply of water of generally good quality which is derived from precipitation that has fallen on the basin. Annual precipitation has ranged from about 30 to 67 inches and has averaged about 45 inches over a 44-year period. Approximately 21 inches of water are returned to the atmosphere each year by evaporation and transpiration; the remainder of the annual precipitation either flows overland to streams or percolates downward to the water table and ultimately flows out of the basin in the Quinebaug River. During the autumn and winter months precipitation normally is sufficient to cause a substantial increase in the amount of water stored underground and in surface reservoirs within the basin, whereas in the summer most of the precipitation is lost through evaporation and transpiration, resulting in sharply reduced streamflow and lowered ground-water levels.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/1050364-mercury-handling-target-system-muon-collider','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1050364-mercury-handling-target-system-muon-collider"><span>Mercury Handling for the Target System for a Muon Collider</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Graves, Van B; Mcdonald, K; Kirk, H.</p> <p>2012-01-01</p> <p>The baseline target concept for a Muon Collider or Neutrino Factory is a free-stream mercury jet being impacted by an 8-GeV proton beam. The target is located within a 20-T magnetic field, which captures the generated pions that are conducted to a downstream decay channel. Both the mercury and the proton beam are introduced at slight downward angles to the magnetic axis. A pool of mercury serves as a receiving reservoir for the mercury and a dump for the unexpended proton beam. The impact energy of the remaining beam and jet are substantial, and it is required that splashes andmore » waves be controlled in order to minimize the potential for interference of pion production at the target. Design issues discussed in this paper include the nozzle, splash mitigation in the mercury pool, the mercury containment vessel, and the mercury recirculation system.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/40957','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/40957"><span>Potentiometric map of the Sparta aquifer system in Mississippi, fall, 1980</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wasson, B.E.</p> <p>1980-01-01</p> <p>This potentiometric map of the Sparta aquifer system is the tenth in a series of maps, prepared by the U.S. Geological Survey in cooperation with the Mississippi Department of Natural Resources, Bureau of Land and Water Resources, delineating the potentiometric surfaces of the major aquifers in Mississippi. In the outcrop area of the Sparta, the potentiometric surface is strongly affected by recharge from precipitation, by topography, and by drainage of the aquifer into streams. The potentiometric surface slopes downward generally to the west away from the area of outcrop and is strongly affected by large ground-water withdrawals in the Jackson, Yazoo City, Cleveland, Clarksdale, and Memphis areas. Historically, water levels in or near the outcrop of the Sparta have shown little or no long-term changes, but during the past 20 years, in much of the confined part of the aquifer, water levels have declined from 1 to 3 feet per year. (USGS)</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017HEAD...1611002W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017HEAD...1611002W"><span>Cosmic Ray Streaming in Galaxy Clusters</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wiener, Joshua; Gould Zweibel, Ellen; Oh, Siang P.</p> <p>2017-08-01</p> <p>The origin of diffuse radio emission in galaxy clusters remains an open question in astrophysics. This emission indicates the presence of cluster-wide magnetic fields and high energy cosmic ray (CR) electrons. I will discuss how the properties of the observed radio emission in clusters are shaped by different CR transport processes, namely CR streaming. Recent work has shown that fast streaming may turn off radio emission on relatively short time scales - a full treatment of magnetohydrodynamic (MHD) wave damping shows that streaming may be even faster than previously thought in high β environments. I will briefly introduce the physics behind CR transport, and present simple numerical simulations of the Coma cluster that predict radio emission, as well as other observable signatures such as gamma radiation that can differentiate between models for the source of the CR electrons.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23345242','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23345242"><span>Stream-related preferences of inputs to the superior colliculus from areas of dorsal and ventral streams of mouse visual cortex.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Quanxin; Burkhalter, Andreas</p> <p>2013-01-23</p> <p>Previous studies of intracortical connections in mouse visual cortex have revealed two subnetworks that resemble the dorsal and ventral streams in primates. Although calcium imaging studies have shown that many areas of the ventral stream have high spatial acuity whereas areas of the dorsal stream are highly sensitive for transient visual stimuli, there are some functional inconsistencies that challenge a simple grouping into "what/perception" and "where/action" streams known in primates. The superior colliculus (SC) is a major center for processing of multimodal sensory information and the motor control of orienting the eyes, head, and body. Visual processing is performed in superficial layers, whereas premotor activity is generated in deep layers of the SC. Because the SC is known to receive input from visual cortex, we asked whether the projections from 10 visual areas of the dorsal and ventral streams terminate in differential depth profiles within the SC. We found that inputs from primary visual cortex are by far the strongest. Projections from the ventral stream were substantially weaker, whereas the sparsest input originated from areas of the dorsal stream. Importantly, we found that ventral stream inputs terminated in superficial layers, whereas dorsal stream inputs tended to be patchy and either projected equally to superficial and deep layers or strongly preferred deep layers. The results suggest that the anatomically defined ventral and dorsal streams contain areas that belong to distinct functional systems, specialized for the processing of visual information and visually guided action, respectively.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AAS...23121207N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AAS...23121207N"><span>Characterizing Milky Way Tidal Streams and Dark Matter with MilkyWay@home</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Newberg, Heidi Jo; Shelton, Siddhartha; Weiss, Jake</p> <p>2018-01-01</p> <p>MilkyWay@home is a 0.5 PetaFLOPS volunteer computing platform that is mapping out the density substructure of the Sagittarius Dwarf Tidal Stream, the so-called bifurcated portion of the Sagittarius Stream, and the Virgo Overdensity, using turnoff stars from the Sloan Digital Sky Survey. It is also using the density of stars along tidal streams such as the Orphan Stream to constrain properties of the dwarf galaxy progenitor of this stream, including the dark matter portion. Both of these programs are enabled by a specially-built optimization package that uses differential evolution or particle swarm methods to find the optimal model parameters to fit a set of data. To fit the density of tidal streams, 20 parameters are simultaneously fit to each 2.5-degree-wide stripe of SDSS data. Five parameters describing the stellar and dark matter profile of the Orphan Stream progenitor and the time that the dwarf galaxy has been evolved through the Galactic potential are used in an n-body simulation that is then fit to observations of the Orphan Stream. New results from MilkyWay@home will be presented. This project was supported by NSF grant AST 16-15688, the NASA/NY Space Grant fellowship, and contributions made by The Marvin Clan, Babette Josephs, Manit Limlamai, and the 2015 Crowd Funding Campaign to Support Milky Way Research.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/wri/wri994007/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/wri/wri994007/"><span>Review of Phosphorus Control Measures in the United States and Their Effects on Water Quality</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Litke, David W.</p> <p>1999-01-01</p> <p>Historical information on phosphorus loadings to the environment and the effect on water quality are summarized in this report, which was produced as part of the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program. Phosphorus is a water-quality constituent of concern because it is often the limiting nutrient responsible for accelerated eutrophication in water bodies. Phosphorus inputs to the environment have increased since 1950 as the use of phosphate fertilizer, manure, and phosphate laundry detergent increased; however, the manufacture of phosphate detergent for household laundry was ended voluntarily in about 1994 after many States had established phosphate detergent bans. Total phosphorus concentrations in raw wastewater effluent contained about 3 milligrams per liter of total phosphorus during the 1940's, increased to about 11 milligrams per liter at the height of phosphate detergent use (1970), and have currently declined to about 5 milligrams per liter. However, in some cases, tertiary wastewater treatment still is needed to effectively improve water quality of streams. Downward trends in phosphorus concentrations since 1970 have been identified in many streams, but median total phosphorus concentrations still exceed the recommended limit of 0.1 milligram per liter across much of the Nation. Data from the NAWQA Program are representative of a variety of phosphorus-control measures, and, therefore, may be used to evaluate the effects of various control strategies. Current areas of concern include: evaluation of the effects of increased manure loadings of phosphorus on soil phosphorus and, subsequently, on ground water and subsurface runoff; determination of point-source and nonpoint-source components of phosphorus loads by geographic modeling and hydrologic separation techniques; and development of methods or indices to evaluate nutrient impairment in streams and rivers to serve as a basis for developing phosphorus criteria or standards.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2011/5181/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2011/5181/"><span>Seasonal seepage investigation on an urbanized reach of the lower Boise River, southwestern Idaho, water year 2010</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Williams, Marshall L.</p> <p>2011-01-01</p> <p>The U.S. Geological Survey in cooperation with the Idaho Department of Water Resources Treasure Valley Comprehensive Aquifer Management Planning effort investigated seasonal groundwater gains and losses on the Boise River, Idaho, starting in November 2009 through August 2010. The investigation was conducted using seepage runs in 11 subreaches over a 14-mile reach from downstream of the inactive streamgage, Boise River below Diversion Dam (U.S. Geological Survey station No. 13203510) to the active Boise River at Glenwood Bridge streamgage (U.S. Geological Survey station No. 13206000). The seepage runs measured mainstem discharge, and significant tributary contributions and diversions along the reach. In addition, an evaluation of the groundwater hydraulic gradient was simultaneously conducted through shallow groundwater mini-piezometers adjacent to the river during February (low stream discharge) and May (high stream discharge) measurement timeframes. November discharge estimates, representative of autumn, had gains and losses that varied by subreach with an overall net gain of 42 ± 8 cubic feet per second (ft3/s). This finding compares favorably to a previous U.S. Geological Survey seepage investigation in November 1996 that found a gaining reach with an estimated gain of 52 ft3/s. This finding also is supported by a U.S. Geological Survey investigation in the study reach in November 1971 that estimated a gain of 74 ft3/s, which largely came from groundwater. The February discharge estimates, representative of winter conditions, showed variability in the reach with a net gain of 52 ft3/s with an uncertainty estimate of ± 7 ft3/s, which is consistent with the low stream discharge findings from November 2009. This finding is further supported by the differential hydraulic head measured at transect sites that qualitatively indicated groundwater to surface-water movement with few exceptions. The May discharge estimates, representative of the spring-time conditions, were gaining or potentially gaining in all but one of the upper subreaches between Boise River below Diversion Dam and Boise River near MK Nature Center sites, with seepage run results supported by hydraulic head differentials indicating a groundwater to surface-water movement. The lower end of the study reach between Boise River near MK Nature Center and Boise River at Glenwood Bridge sites showed more variability with observed hydraulic head differentials that partially supported the potential gains or losses in the reach. Overall, the reach had a calculated net gain of 24 ± 51 ft3/s and, therefore, this estimate may or may not reflect the actual conditions in the reach. The groundwater gains and losses in August, representative of summer conditions, varied in both the upper and lower parts of the reach, with a net loss of -88 ± 69 ft3/s. Overall, the reach experienced a net gain from groundwater at low stream discharges (November and February), a net loss to groundwater at moderately high stream discharge (August), and an ambiguous finding at a higher stream discharge (May). The hydraulic head differentials measured between the groundwater and surface water largely supported the calculated gain and loss estimates in the subreaches, with a potential for groundwater to surface-water movement at low stream discharge in February, and variability during high stream discharge conditions in May.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29690251','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29690251"><span>Cambarus polypilosus, a new species of stream-dwelling crayfish (Decapoda: Cambaridae) from the Western Highland Rim of Tennessee, USA.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Loughman, Zachary J; Williams, Bronwyn W</p> <p>2018-04-03</p> <p>Cambarus polypilosus sp. nov. is a stream-dwelling crayfish endemic to tributaries in the Buffalo and lower Duck River drainage, and a reach of the lower Tennessee River in the Western Highland Rim of West-Central Tennessee, U.S.A. The new species is closely allied to the three members of the former subgenus Glareocola, but can be differentiated from each by a combination of characters, including body size, coloration, spination, setation, and form I male gonopod morphology. Several meristic measurements and ratios also differentiate C. polypilosus sp. nov. from Cambarus friaufi, to which it is morphologically most similar. Cambarus polypilosus sp. nov. appears to be common in cherty gravel and cobble habitats, where it is typically found in interstices at depths of 0.3 m or more below the substrate surface.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28557668','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28557668"><span>Dynamic interaction of a downward plane jet and a cough jet with respect to particle transmission: An analytical and experimental study.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cao, Guangyu; Liu, Shichao; Boor, Brandon E; Novoselac, Atila</p> <p>2017-08-01</p> <p>A cough jet can travel beyond the breathing zone of the source person, and thus, infectious viral- and bacterial-laden particles can be transported from the source person to others in close proximity. To reduce the interpersonal transmission of coughed particles, the objective of this study was to analytically and experimentally investigate the performance of downward plane jets with various discharge velocities. Chamber measurements were conducted to examine the interaction between a transient cough jet (discharge velocities of 12 m/sec and 16 m/sec) and a steady downward plane jet (discharge velocities from 1.0-8.5 m/sec) with respect to the transport of and human exposure to coughed particles. The results show that a relatively high-speed cough can easily penetrate a downward plane jet with a discharge velocity of less than 6 m/sec. A downward plane jet with a discharge velocity of 8.5 m/sec can bend the cough jet to a certain extent. In this study, momentum comparison of the cough jet and the downward plane jet shows that the value of personal exposure to coughed particles depends on the ratio of jet momentums. The results show that when the two momentums are equivalent or if the downward plane jet has a greater momentum, the cough jet is deflected downward and does not reach the breathing zone of the target thermal dummy. Using the ratio of the two momentums, it may be estimated whether the transmission of a cough jet can be controlled. A trajectory model was developed based on the ratio of the two momentums of a cough jet and a downward jet and was validated using the experimental data. In addition, the predicted trajectory of the cough jet agreed well with the results from smoke visualization experiments. This model can be used to guide the design of downward plane jet systems for protection of occupants from coughed particles.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/867860','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/867860"><span>Fine coal cleaning via the micro-mag process</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Klima, Mark S.; Maronde, Carl P.; Killmeyer, Richard P.</p> <p>1991-01-01</p> <p>A method of cleaning particulate coal which is fed with a dense medium slurry as an inlet feed to a cyclone separator. The coal particle size distribution is in the range of from about 37 microns to about 600 microns. The dense medium comprises water and ferromagnetic particles that have a relative density in the range of from about 4.0 to about 7.0. The ferromagnetic particles of the dense medium have particle sizes of less than about 15 microns and at least a majority of the particle sizes are less than about 5 microns. In the cyclone, the particulate coal and dense-medium slurry is separated into a low gravity product stream and a high gravity produce stream wherein the differential in relative density between the two streams is not greater than about 0.2. The low gravity and high gravity streams are treated to recover the ferromagnetic particles therefrom.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011ExFl...50...89L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011ExFl...50...89L"><span>Stereo particle image velocimetry of nonequilibrium turbulence relaxation in a supersonic boundary layer</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lapsa, Andrew P.; Dahm, Werner J. A.</p> <p>2011-01-01</p> <p>Measurements using stereo particle image velocimetry are presented for a developing turbulent boundary layer in a wind tunnel with a Mach 2.75 free stream. As the boundary layer exits from the tunnel nozzle and moves through the wave-free test section, small initial departures from equilibrium turbulence relax, and the boundary layer develops toward the equilibrium zero-pressure-gradient form. This relaxation process is quantified by comparison of first and second order mean, fluctuation, and gradient statistics to classical inner and outer layer scalings. Simultaneous measurement of all three instantaneous velocity components enables direct assessment of the complete turbulence anisotropy tensor. Profiles of the turbulence Mach number show that, despite the M = 2.75 free stream, the incompressibility relation among spatial gradients in the velocity fluctuations applies. This result is used in constructing various estimates of the measured-dissipation rate, comparisons among which show only remarkably small differences over most of the boundary layer. The resulting measured-dissipation profiles, together with measured profiles of the turbulence kinetic energy and mean-flow gradients, enable an assessment of how the turbulence anisotropy relaxes toward its equilibrium zero-pressure-gradient state. The results suggest that the relaxation of the initially disturbed turbulence anisotropy profile toward its equilibrium zero-pressure-gradient form begins near the upper edge of the boundary layer and propagates downward through the defect layer.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ERL....12c4022V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ERL....12c4022V"><span>Prospects for generating electricity by large onshore and offshore wind farms</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Volker, Patrick J. H.; Hahmann, Andrea N.; Badger, Jake; Jørgensen, Hans E.</p> <p>2017-03-01</p> <p>The decarbonisation of energy sources requires additional investments in renewable technologies, including the installation of onshore and offshore wind farms. For wind energy to remain competitive, wind farms must continue to provide low-cost power even when covering larger areas. Inside very large wind farms, winds can decrease considerably from their free-stream values to a point where an equilibrium wind speed is reached. The magnitude of this equilibrium wind speed is primarily dependent on the balance between turbine drag force and the downward momentum influx from above the wind farm. We have simulated for neutral atmospheric conditions, the wind speed field inside different wind farms that range from small (25 km2) to very large (105 km2) in three regions with distinct wind speed and roughness conditions. Our results show that the power density of very large wind farms depends on the local free-stream wind speed, the surface characteristics, and the turbine density. In onshore regions with moderate winds the power density of very large wind farms reaches 1 W m-2, whereas in offshore regions with very strong winds it exceeds 3 W m-2. Despite a relatively low power density, onshore regions with moderate winds offer potential locations for very large wind farms. In offshore regions, clusters of smaller wind farms are generally preferable; under very strong winds also very large offshore wind farms become efficient.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2010/5112/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2010/5112/"><span>Hydrogeology and groundwater availability in Clarke County, Virginia</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Nelms, David L.; Moberg, Roger M.</p> <p>2010-01-01</p> <p>The prolonged drought between 1999 and 2002 drew attention in Clarke County, Virginia, to the quantity and sustainability of its groundwater resources. The groundwater flow systems of the county are complex and are controlled by the extremely folded and faulted geology that underlies the county. A study was conducted between October 2002 and October 2008 by the U.S. Geological Survey, in cooperation with Clarke County, Virginia, to describe the hydrogeology and groundwater availability in the county and to establish a long-term water monitoring network. The study area encompasses approximately 177 square miles and includes the carbonate and siliciclastic rocks of the Great Valley section of the Valley and Ridge Physiographic Province and the metamorphic rocks of the Blue Ridge Physiographic Province (Blue Ridge). High-yielding wells generally tend to cluster along faults, within lineament zones, and in areas of tight folding throughout the county. Water-bearing zones are generally within 250 feet (ft) of land surface; however, median depths are slightly deeper for the hydrogeologic units of the Blue Ridge than for those of the Great Valley section of the county. Total water-level fluctuations between October 2002 and October 2008 ranged from 2.86 to 87.84 ft across the study area, with an average of 24.15 ft. Generally, water-level fluctuations were greatest near hydrologic divides, in isolated elevated areas, and in the Opequon Creek Basin. Seasonally, water-level highs occur in the early spring at the end of the major groundwater recharge period and lows occur in late autumn when evapotranspiration rates begin to decrease. An overall downward trend in water levels between 2003 and 2008, which closely follows a downward trend in annual precipitation over the same period, was observed in a majority of wells in the Great Valley and in some of the wells in the Blue Ridge. Water-level fluctuations in the Blue Ridge tend to follow current meteorological conditions, and seasonal highs and lows tend to shift in response to the current conditions. Springs generally are present along faults and fold axes, and discharges for the study period ranged from dry to 10 cubic feet per second. A similar downward trend in discharges correlates with the trend in water levels and is indicative of an aquifer system that, over time, drains to a base level controlled by springs and streams. Point discharge from springs can occur as the start of flows of streams and creeks, along banks, and as discrete discharge through streambeds in the Great Valley. For the most part, streams, creeks, and rivers in the Great Valley function as aqueducts. Springs in the Blue Ridge have relatively low discharge rates, have small drainage areas, and are susceptible to current meteorological conditions. Estimates of effective groundwater recharge from 2001 to 2007 ranged from 6.4 to 23.0 inches per year (in/yr) in the Dry Marsh Run and Spout Run Basins with averages of 11.6 and 11.9 in/yr, respectively. Base flow accounted for between 80 and 97 percent of mean streamflow and averaged about 90 percent in these basins. The high base-flow index values (percent of streamflow from base flow) in the Dry Marsh Run and Spout Run Basins indicate that groundwater is the dominant source of streamflow during both wet and drought conditions. Between 46 and 82 percent of the precipitation that fell on the Dry Marsh Run and Spout Run Basins from 2001 to 2007 was removed by evapotranspiration, and an average of approximately 30 percent of the precipitation reached the water table as effective recharge. The high permeability of the rocks and low relief in these basins are not conducive for runoff; therefore, on average, only about 3 to 4 percent of the precipitation becomes runoff. Groundwater flow systems in the county are extremely vulnerable to current climatic conditions. Successive years of below-average effective recharge cause declines in water levels, spring discha</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/27444','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/27444"><span>Potential for downward leakage to the Floridan Aquifer, Green Swamp area, central Florida</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Grubb, H.F.</p> <p>1977-01-01</p> <p>A qualitative evaluation of the potential for downward leakage from the surficial sand aquifer to the underlying Floridan aquifer was made for the Green Swamp area (about 870 sq mi) in central Florida. Downward leakage, or recharge, is limited under natural conditions owing to the nearness to land surface of the potentiometric surface of both the sand aquifer and the underlying Floridan aquifer. Continuous cores of the unconsolidated section were obtained at 74 sites in the study area and were evaluated for downward leakage potential based on grain-size distribution. Sand percentage was estimated for each interval or bed from microscopic examination of the core samples. The four maps prepared from this data show sand thickness, clay thickness, relative vertical hydraulic conductivity of the confining beds and the relative potential for downward leakage. About 20 percent (178 sq mi) of the area classified has a relatively good potential for downward leakage; almost 50 percent of the area has a relatively poor potential. (Woodard-USGS)</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060013150&hterms=Shrink&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DShrink','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060013150&hterms=Shrink&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DShrink"><span>A Statistical Analysis of Loop-Top Motion in Solar Limb Flares</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Holman, Gordon D.; Sui, Linhui; Brosius, D. G.; Dennis, Brian R.</p> <p>2005-01-01</p> <p>Previous studies of hot, thermal solar flare loops imaged with the Ramaty High Energy Solar Spectroscopic Imager (RHESSI) have identified several flares for which the loop top shrinks downward early in the impulsive phase and then expands upward later in the impulsive phase (Sui & Holman 2003; Sui, Holman & Dennis 2004; Veronig et al. 2005). This early downward motion is not predicted by flare models. We study a statistical sample of RHESSI flares to assess how common this evolution is and to better characterize it. In a sample of 88 flares near the solar lin$ that show identifiable loop structure in RHESSI images, 66% (58 flares) showed downward loop-top motion followed by upward motion. We therefore conclude that the early downward motion is a frequent characteristic of flare loops. We obtain the distribution of the timing of the change from downward to upward motion relative to flare start and peak times. We also obtain the distributions of downward and upward speeds.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008SPIE.6822E..0FL','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008SPIE.6822E..0FL"><span>Exploring inter-frame correlation analysis and wavelet-domain modeling for real-time caption detection in streaming video</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Jia; Tian, Yonghong; Gao, Wen</p> <p>2008-01-01</p> <p>In recent years, the amount of streaming video has grown rapidly on the Web. Often, retrieving these streaming videos offers the challenge of indexing and analyzing the media in real time because the streams must be treated as effectively infinite in length, thus precluding offline processing. Generally speaking, captions are important semantic clues for video indexing and retrieval. However, existing caption detection methods often have difficulties to make real-time detection for streaming video, and few of them concern on the differentiation of captions from scene texts and scrolling texts. In general, these texts have different roles in streaming video retrieval. To overcome these difficulties, this paper proposes a novel approach which explores the inter-frame correlation analysis and wavelet-domain modeling for real-time caption detection in streaming video. In our approach, the inter-frame correlation information is used to distinguish caption texts from scene texts and scrolling texts. Moreover, wavelet-domain Generalized Gaussian Models (GGMs) are utilized to automatically remove non-text regions from each frame and only keep caption regions for further processing. Experiment results show that our approach is able to offer real-time caption detection with high recall and low false alarm rate, and also can effectively discern caption texts from the other texts even in low resolutions.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18923862','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18923862"><span>Reversed differential cyanosis in the newborn: a clinical finding in the supracardiac total anomalous pulmonary venous connection.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yap, Shook H; Anania, Nicole; Alboliras, Ernerio T; Lilien, Lawrence D</p> <p>2009-04-01</p> <p>The newborn can experience two types of differential cyanosis (DC). The common type of DC occurs when oxygen saturation in the right hand is greater than in the foot. The second type of DC, reversed differential cyanosis (RDC), occurs when oxygen saturation is lower in the right hand than in the foot. This phenomenon is observed in transposition of the great arteries (TGA) with patent ductus arteriosis (PDA) and elevated pulmonary vascular resistance or in TGA with PDA and preductal aortic interruption or coarctation. This report describes a case of RDC not previously described involving an infant with supracardiac total anomalous pulmonary venous connection (TAPVC). In supracardiac TAPVC, RDC results from streaming of highly saturated superior vena cava (SVC) blood into the right ventricle, out the main pulmonary artery, through a PDA, and to the descending aorta, with streaming of more desaturated blood from the inferior vena cava (IVC) into the left atrium across the atrial septal defect (ASD)/foramen ovale. Therefore, as part of a neonatal examination to rule out congenital heart disease (CHD), simultaneous pre- and postductal oxygen saturations should be documented. The presence of RDC should initiate immediate full cardiac evaluation for CHD. Supracardiac TAPVC should be included in the differential diagnosis if RDC is observed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19760036872&hterms=coulomb&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dcoulomb','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19760036872&hterms=coulomb&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dcoulomb"><span>The role of Coulomb collisions in limiting differential flow and temperature differences in the solar wind</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Neugebauer, M.</p> <p>1976-01-01</p> <p>Data obtained by OGO 5 are used to confirm IMP 6 observations of an inverse dependence of the helium-to-hydrogen temperature ratio in the solar wind on the ratio of solar-wind expansion time to the Coulomb-collision equipartition time. The analysis is then extended to determine the relation of the difference between the hydrogen and helium bulk velocities (the differential flow vector) with the ratio between the solar-wind expansion time and the time required for Coulomb collisions to slow down a beam of ions passing through a plasma. It is found that the magnitude of the differential flow vector varies inversely with the time ratio when the latter is small and approaches zero when it is large. These results are shown to suggest a model of continuous preferential heating and acceleration of helium (or cooling and deceleration of hydrogen), which is cancelled or limited by Coulomb collisions by the time the plasma has reached 1 AU. Since the average dependence of the differential flow vector on the time ratio cannot explain all the systematic variations of the vector observed in corotating high-velocity streams, it is concluded that additional helium acceleration probably occurs on the leading edge of such streams.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://eric.ed.gov/?q=changes+AND+phase&pg=5&id=EJ954210','ERIC'); return false;" href="https://eric.ed.gov/?q=changes+AND+phase&pg=5&id=EJ954210"><span>Communication and Voluntary Downward Career Changes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Tan, Claire L.; Kramer, Michael W.</p> <p>2012-01-01</p> <p>Downward career changes are challenging in societies which place a premium on the accumulation of material wealth and discourage risk-taking, such as Singapore. To better understand how individuals manage their identities during such changes, 30 individuals who had completed a voluntary downward career change were interviewed. Results suggest…</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.H23D1713P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.H23D1713P"><span>Residence-time framework for modeling multicomponent reactive transport in stream hyporheic zones</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Painter, S. L.; Coon, E. T.; Brooks, S. C.</p> <p>2017-12-01</p> <p>Process-based models for transport and transformation of nutrients and contaminants in streams require tractable representations of solute exchange between the stream channel and biogeochemically active hyporheic zones. Residence-time based formulations provide an alternative to detailed three-dimensional simulations and have had good success in representing hyporheic exchange of non-reacting solutes. We extend the residence-time formulation for hyporheic transport to accommodate general multicomponent reactive transport. To that end, the integro-differential form of previous residence time models is replaced by an equivalent formulation based on a one-dimensional advection dispersion equation along the channel coupled at each channel location to a one-dimensional transport model in Lagrangian travel-time form. With the channel discretized for numerical solution, the associated Lagrangian model becomes a subgrid model representing an ensemble of streamlines that are diverted into the hyporheic zone before returning to the channel. In contrast to the previous integro-differential forms of the residence-time based models, the hyporheic flowpaths have semi-explicit spatial representation (parameterized by travel time), thus allowing coupling to general biogeochemical models. The approach has been implemented as a stream-corridor subgrid model in the open-source integrated surface/subsurface modeling software ATS. We use bedform-driven flow coupled to a biogeochemical model with explicit microbial biomass dynamics as an example to show that the subgrid representation is able to represent redox zonation in sediments and resulting effects on metal biogeochemical dynamics in a tractable manner that can be scaled to reach scales.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4194271','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4194271"><span>Differential modulation of auditory responses to attended and unattended speech in different listening conditions</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kong, Ying-Yee; Mullangi, Ala; Ding, Nai</p> <p>2014-01-01</p> <p>This study investigates how top-down attention modulates neural tracking of the speech envelope in different listening conditions. In the quiet conditions, a single speech stream was presented and the subjects paid attention to the speech stream (active listening) or watched a silent movie instead (passive listening). In the competing speaker (CS) conditions, two speakers of opposite genders were presented diotically. Ongoing electroencephalographic (EEG) responses were measured in each condition and cross-correlated with the speech envelope of each speaker at different time lags. In quiet, active and passive listening resulted in similar neural responses to the speech envelope. In the CS conditions, however, the shape of the cross-correlation function was remarkably different between the attended and unattended speech. The cross-correlation with the attended speech showed stronger N1 and P2 responses but a weaker P1 response compared with the cross-correlation with the unattended speech. Furthermore, the N1 response to the attended speech in the CS condition was enhanced and delayed compared with the active listening condition in quiet, while the P2 response to the unattended speaker in the CS condition was attenuated compared with the passive listening in quiet. Taken together, these results demonstrate that top-down attention differentially modulates envelope-tracking neural activity at different time lags and suggest that top-down attention can both enhance the neural responses to the attended sound stream and suppress the responses to the unattended sound stream. PMID:25124153</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70025412','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70025412"><span>Determining long time-scale hyporheic zone flow paths in Antarctic streams</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Gooseff, M.N.; McKnight, Diane M.; Runkel, R.L.; Vaughn, B.H.</p> <p>2003-01-01</p> <p>In the McMurdo Dry Valleys of Antarctica, glaciers are the source of meltwater during the austral summer, and the streams and adjacent hyporheic zones constitute the entire physical watershed; there are no hillslope processes in these systems. Hyporheic zones can extend several metres from each side of the stream, and are up to 70 cm deep, corresponding to a lateral cross-section as large as 12 m2, and water resides in the subsurface year around. In this study, we differentiate between the near-stream hyporheic zone, which can be characterized with stream tracer experiments, and the extended hyporheic zone, which has a longer time-scale of exchange. We sampled stream water from Green Creek and from the adjacent saturated alluvium for stable isotopes of D and 18O to assess the significance and extent of stream-water exchange between the streams and extended hyporheic zones over long time-scales (days to weeks). Our results show that water residing in the extended hyporheic zone is much more isotopically enriched (up to 11??? D and 2.2??? 18O) than stream water. This result suggests a long residence time within the extended hyporheic zone, during which fractionation has occured owing to summer evaporation and winter sublimation of hyporheic water. We found less enriched water in the extended hyporheic zone later in the flow season, suggesting that stream water may be exchanged into and out of this zone, on the time-scale of weeks to months. The transient storage model OTIS was used to characterize the exchange of stream water with the extended hyporheic zone. Model results yield exchange rates (??) generally an order magnitude lower (10-5 s-1) than those determined using stream-tracer techniques on the same stream. In light of previous studies in these streams, these results suggest that the hyporheic zones in Antarctic streams have near-stream zones of rapid stream-water exchange, where 'fast' biogeochemical reactions may influence water chemistry, and extended hyporheic zones, in which slower biogeochemical reaction rates may affect stream-water chemistry at longer time-scales. Copyright ?? 2003 John Wiley & Sons, Ltd.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007ExFl...42..847F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007ExFl...42..847F"><span>Simultaneous velocity and concentration field measurements of passive-scalar mixing in a confined rectangular jet</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Feng, Hua; Olsen, Michael G.; Hill, James C.; Fox, Rodney O.</p> <p>2007-06-01</p> <p>Simultaneous velocity and concentration fields in a confined liquid-phase rectangular jet with a Reynolds number based on the hydraulic diameter of 50,000 (or 10,000 based on the velocity difference between streams and the jet exit dimension) and a Schmidt number of 1,250 were obtained by means of a combined particle image velocimetry (PIV) and planar laser-induced fluorescence (PLIF) system. Data were collected at the jet exit and six further downstream locations. The velocity and concentration field data were analyzed for flow statistics such as turbulent fluxes, turbulent viscosity and diffusivity, and turbulent Schmidt number ( Sc T ). The streamwise turbulent flux was found to be larger than the transverse turbulent flux, and the mean concentration gradient was not aligned with the turbulent flux vector. The average Sc T was found to vary both in streamwise and in cross stream directions and had a mean value around 0.8, a value consistent with the literature. Spatial correlation fields of turbulent fluxes and concentration were then determined. The R u'ϕ' correlation was elliptical in shape with a major axis tilted downward with respect to the streamwise axis, whereas the R v'ϕ' correlation was an ellipse with a major axis aligned with the cross-stream direction. Negative regions of R u'ϕ' were observed in the outer streams, and these negatively correlated regions decayed with downstream distance and finally disappeared altogether. The R ϕ'ϕ' correlation field was found to be an ellipse with the major axis inclined at about 45° with respect to the streamwise direction. Linear stochastic estimation was used to interpret spatial correlation data and to determine conditional flow structures. It is believed that a vortex street formed near the splitter plate is responsible for the negatively correlated region observed in the R u'ϕ' spatial correlations of turbulent fluxes. A positive concentration fluctuation event was observed to correspond to a finger of nearly uniform concentration fluid reaching out into the outer stream, whereas a negative event corresponds to a pocket of nearly uniform fluid being entrained from the outer stream into the center jet region. Large-scale vortical structures were observed in the conditional velocity fields with an elliptical shape and a streamwise major axis. The growth of the structure size increased linearly initially but then grew more slowly as the flow transitioned toward channel flow.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.nco.ncep.noaa.gov/pmb/products/gfs/gfs_upgrade/gdas1.t06z.sfluxgrbf06.grib2.shtml','SCIGOVWS'); return false;" href="http://www.nco.ncep.noaa.gov/pmb/products/gfs/gfs_upgrade/gdas1.t06z.sfluxgrbf06.grib2.shtml"><span>Inventory of File gdas1.t06z.sfluxgrbf06.grib2</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.science.gov/aboutsearch.html">Science.gov Websites</a></p> <p></p> <p></p> <p>hour ave Visible Diffuse Downward Solar Flux [W/m^2] 036 surface NBDSF 0-6 hour ave Near <em>IR</em> Beam Downward Solar Flux [W/m^2] 037 surface NDDSF 0-6 hour ave Near <em>IR</em> Diffuse Downward Solar Flux [W/m^2] 038</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.nco.ncep.noaa.gov/pmb/products/gfs/gfs_upgrade/gfs.t06z.sfluxgrbf06.grib2.shtml','SCIGOVWS'); return false;" href="http://www.nco.ncep.noaa.gov/pmb/products/gfs/gfs_upgrade/gfs.t06z.sfluxgrbf06.grib2.shtml"><span>Inventory of File gfs.t06z.sfluxgrbf06.grib2</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.science.gov/aboutsearch.html">Science.gov Websites</a></p> <p></p> <p></p> <p>hour ave Visible Diffuse Downward Solar Flux [W/m^2] 036 surface NBDSF 0-6 hour ave Near <em>IR</em> Beam Downward Solar Flux [W/m^2] 037 surface NDDSF 0-6 hour ave Near <em>IR</em> Diffuse Downward Solar Flux [W/m^2] 038</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26514797','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26514797"><span>Effect of mesohabitats on responses of invertebrate community structure in streams under different land uses.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>da Silva, Marcos Vinícius Dias; Rosa, Beatriz F J V; Alves, Roberto G</p> <p>2015-11-01</p> <p>Riparian vegetation is one of the most important abiotic components determining the water flow pattern in lotic ecosystems, influencing the composition, richness, and diversity of invertebrates. We have identified whether differences in the structure of the assemblages of invertebrates between riffles and pools may influence the responses of fauna to the effects of land use. In addition, we investigated which fauna metrics are responsible for the differentiation between riffles and pools in streams subject to different land uses. During the dry season of 2012, the main substrates of riffles and pools were sampled (Surber collector) from nine streams within forest, pasture, and urban areas. Principal component analysis (PCA) and Permanova showed differences in the set of environmental variables between streams and mesohabitats. The first PCA axis distinguished the forest and pasture streams from the urban area streams and was related to variables indicative of nutrient enrichment and land use, while the second axis was formed by velocity flow and by the quantities of ultrafine and coarse sand, which distinguished the riffles and pools of the streams. The faunal composition distinguished the streams in pasture and forest areas from the urban streams. Riffles and pools were not concordant in the representation of the invertebrate fauna, indicating the importance of sampling both mesohabitats in the types of streams investigated. The richness, taxonomic composition, and relative abundance of families of Ephemeroptera, Plecoptera, and Trichoptera showed robust responses in riffles to the effects of environmental changes, while in pools, only the richness showed a significant response. It was possibly concluded that riffles were more sensitive in detecting the effects of land use. The information from this study help to understand how the community of invertebrates and the types of habitats in streams may be affected by anthropogenic impacts.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19780066385&hterms=differential+equations+application&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Ddifferential%2Bequations%2Bapplication','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19780066385&hterms=differential+equations+application&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Ddifferential%2Bequations%2Bapplication"><span>A comparison of the Method of Lines to finite difference techniques in solving time-dependent partial differential equations. [with applications to Burger equation and stream function-vorticity problem</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kurtz, L. A.; Smith, R. E.; Parks, C. L.; Boney, L. R.</p> <p>1978-01-01</p> <p>Steady state solutions to two time dependent partial differential systems have been obtained by the Method of Lines (MOL) and compared to those obtained by efficient standard finite difference methods: (1) Burger's equation over a finite space domain by a forward time central space explicit method, and (2) the stream function - vorticity form of viscous incompressible fluid flow in a square cavity by an alternating direction implicit (ADI) method. The standard techniques were far more computationally efficient when applicable. In the second example, converged solutions at very high Reynolds numbers were obtained by MOL, whereas solution by ADI was either unattainable or impractical. With regard to 'set up' time, solution by MOL is an attractive alternative to techniques with complicated algorithms, as much of the programming difficulty is eliminated.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930092289','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930092289"><span>Similar solutions for the compressible laminar boundary layer with heat transfer and pressure gradient</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cohen, Clarence B; Reshotko, Eli</p> <p>1956-01-01</p> <p>Stewartson's transformation is applied to the laminar compressible boundary-layer equations and the requirement of similarity is introduced, resulting in a set of ordinary nonlinear differential equations previously quoted by Stewartson, but unsolved. The requirements of the system are Prandtl number of 1.0, linear viscosity-temperature relation across the boundary layer, an isothermal surface, and the particular distributions of free-stream velocity consistent with similar solutions. This system admits axial pressure gradients of arbitrary magnitude, heat flux normal to the surface, and arbitrary Mach numbers. The system of differential equations is transformed to integral system, with the velocity ratio as the independent variable. For this system, solutions are found by digital computation for pressure gradients varying from that causing separation to the infinitely favorable gradient and for wall temperatures from absolute zero to twice the free-stream stagnation temperature. Some solutions for separated flows are also presented.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999PhDT.......112H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999PhDT.......112H"><span>Effects of orientation and downward-facing convex curvature on pool-boiling critical heat flux</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Howard, Alicia Ann Harris</p> <p></p> <p>Photographic studies of near-saturated pool boiling on both inclined flat surfaces and a downward-facing convex surface were conducted in order to determine the physical mechanisms that trigger critical heat flux (CHF). Based on the vapor behavior observed just prior to CHF, it is shown for the flat surfaces that the surface orientations can be divided into three regions: upward-facing (0-60°), near-vertical (60-165°), and downward-facing (165-180°) each region is associated with a unique CHIP trigger mechanism. In the upward-facing region, the buoyancy forces remove the vapor vertically off the heater surface. The near- vertical region is characterized by a wavy liquid-vapor interface which sweeps along the heater surface. In the downward-facing region, the vapor repeatedly stratifies on the heater surface, greatly decreasing CHF. The vapor behavior along the convex surface is cyclic in nature and similar to the nucleation/coalescence/stratification/release procedure observed for flat surfaces in the downward-facing region. The vapor stratification occurred at the bottom (downward-facing) heaters on the convex surface. CHF is always triggered on these downward-facing heaters and then propagates up the convex surface, and the orientations of these heaters are comparable with the orientation range of the flat surface downward-facing region. The vast differences between the observed vapor behavior within the three regions and on the convex surface indicate that a single overall pool boiling CHF model cannot possibly account for all the observed effects. Upward-facing surfaces have been examined and modeled extensively by many investigators and a few investigators have addressed downward-facing surfaces, so this investigation focuses on modeling the near-vertical region. The near-vertical CHF model incorporates classical two-dimensional interfacial instability theory, a separated flow model, an energy balance, and a criterion for separation of the wavy interface from the surface at CHF. The model was tested for different fluids and shows good agreement with CHF data. Additionally, the instability theory incorporated into this model accurately predicts the angle of transition between the near-vertical and downward-facing regions.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4788512','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4788512"><span>Differentially Private Frequent Sequence Mining via Sampling-based Candidate Pruning</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Xu, Shengzhi; Cheng, Xiang; Li, Zhengyi; Xiong, Li</p> <p>2016-01-01</p> <p>In this paper, we study the problem of mining frequent sequences under the rigorous differential privacy model. We explore the possibility of designing a differentially private frequent sequence mining (FSM) algorithm which can achieve both high data utility and a high degree of privacy. We found, in differentially private FSM, the amount of required noise is proportionate to the number of candidate sequences. If we could effectively reduce the number of unpromising candidate sequences, the utility and privacy tradeoff can be significantly improved. To this end, by leveraging a sampling-based candidate pruning technique, we propose a novel differentially private FSM algorithm, which is referred to as PFS2. The core of our algorithm is to utilize sample databases to further prune the candidate sequences generated based on the downward closure property. In particular, we use the noisy local support of candidate sequences in the sample databases to estimate which sequences are potentially frequent. To improve the accuracy of such private estimations, a sequence shrinking method is proposed to enforce the length constraint on the sample databases. Moreover, to decrease the probability of misestimating frequent sequences as infrequent, a threshold relaxation method is proposed to relax the user-specified threshold for the sample databases. Through formal privacy analysis, we show that our PFS2 algorithm is ε-differentially private. Extensive experiments on real datasets illustrate that our PFS2 algorithm can privately find frequent sequences with high accuracy. PMID:26973430</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018HMT....54.1669P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018HMT....54.1669P"><span>Upward and downward facing high mass flux spray cooling with additives: A novel technique to enhance the heat removal rate at high initial surface temperature</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pati, A. R.; Kumar, A.; Mohapatra, S. S.</p> <p>2018-06-01</p> <p>The objective of the current work is to enhance the spray cooling by changing the orientation of the nozzle with different additives (acetone, methanol, ethanol, benzene, n-hexane, tween 20 and salt) in water. The experiments are carried out by upward, downward and both upward and downward facing sprays. The optimization result depicts that the spray produced by upward facing spray gives higher heat flux than the downward facing spray and also cooling by both the upward and downward facing spray simultaneously produces better result than the individual. Further experiments with both upward and downward facing spray by using different coolants reveal that in case of cooling by ethanol (500 ppm) + water mixture, the maximum enhancement of surface heat flux ( 2.57 MW/m2) and cooling rate (204 °C/s) is observed. However, the minimum surface heat flux is achieved in case of methanol (100 ppm) + water due to higher contact angle (710) among all the considered coolants.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA267628','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA267628"><span>Ground Wave Emergency Network Final Operational Capability: Environmental Assessment for Central Utah Relay Node, Site Number RN 8C920UT</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1993-04-16</p> <p>Utah and Juab counties, centered approximately 5 miles northwest of the town of Nephi in Juab County, in the Basin and Range portion of the...3.2 to 3.6 of this EA. Permanent streams are rare in the SSA; no stream leaves the SSA because each of the valleys forms a closed basin . The northern...the SSA is differentiated by distinct topographical basins . All runoff in the northern portion of the SSA drains into Utah Lake. Runoff in the</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/5850898-changes-extracellular-calcium-activity-during-gravity-sensing-maize-roots','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/5850898-changes-extracellular-calcium-activity-during-gravity-sensing-maize-roots"><span>Changes in extracellular calcium activity during gravity sensing in maize roots</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Bjoerkman, T.; Cleland, R.E.</p> <p>1990-05-01</p> <p>A redistribution of calcium downward across the root cap has been proposed as an essential part of gravitropism in roots. Exogenous {sup 45}Ca moves preferentially downward across gravistimulated maize root tips. However, because of the many calcium-binding sites in the apoplast, this might not result in a physiologically effect change in the apoplasmic calcium activity. To test whether there is such a change, we measured the effect of gravistimulation on the calcium activity with calcium-specific microelectrodes. Decapped maize roots (Zea mays L. cv. Golden Cross Bantam) were grown for 31 h to regenerate gravitropic sensitivity, but not root caps. Themore » calcium activity in the apoplasm surrounding the gravity-sensing cells could then be measured. The initial pCa was 2.60 {plus minus} 0.28 (approx 2.5 mM). The calcium activity on the upper side of the root tip remained constant for about five minutes after gravistimulation, then decreased by about one half. On the lower side, after a similar lag the calcium activity doubled. Control roots, which were decapped but measured before recovering gravisensitivity (19 h), showed no change in calcium activity. We have found a distinct and rapid differential in the apoplasmic calcium activity between the upper and lower sides of gravistimulated maize root tips.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/9805448','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/9805448"><span>Orbital lymphoma masquerading as thyroid ophthalmopathy.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Boyce, P J</p> <p>1998-10-01</p> <p>Lymphoid tumors are known to originate within the lacrimal gland and orbital fat. Ocular findings commonly seen are a palpable mass with proptosis and downward displacement of the globe. Graves' ophthalmopathy is the most common orbital pathology occurring in the general population. Signs and symptoms of Graves' ophthalmopathy, such as unilateral or bilateral proptosis, double vision, limitation of movement of the extraocular muscles, are not specific for this condition. A 57-year-old man came to us with a chief symptom of "eye swelling" for the last 3 years. He had been diagnosed with hyperthyroidism and had received three surgical procedures for orbital decompression. Clinical findings included limitation of upward and downward gaze, exophthalmometry readings of 30 1/2 mm O.D. and 31 mm O.S. (with a base of 112), and profound proptosis with fatty tissue prolapse. Subsequent thyroid testing revealed euthyroid status and computed tomography scan revealed orbital lymphoma. Orbital involvement from a malignant nodular histiocytic lymphoma resulted in a proptosis similar to that observed in Graves' ophthalmopathy. This very unusual presentation of orbital lymphoma mimicked Graves' disease so closely that the true cause was overlooked. This case emphasizes the need to include space-occupying lesions in the differential diagnosis of proptosis and gaze restrictions. The disease process and controversial management strategies are discussed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2012/1052/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2012/1052/"><span>Summary and evaluation of the quality of stormwater in Denver, Colorado, 2006-2010</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Stevens, Michael R.; Slaughter, Cecil B.</p> <p>2012-01-01</p> <p>Stormwater in the Denver area was sampled by the U.S. Geological Survey, in cooperation with the Urban Drainage and Flood Control District, in a network of 5 monitoring stations - 3 on the South Platte River and 2 on streams tributary to the South Platte River, Sand Creek, and Toll Gate Creek beginning in January 2006 and continuing through December 2010. Stormwater samples were analyzed at the U.S. Geological Survey National Water Quality Laboratory during 2006-2010 for water-quality properties such as pH, specific conductance, hardness, and residue on evaporation at 105 degrees Celsius; for constituents such as major ions (calcium, magnesium), organic carbon and nutrients, including ammonia plus organic nitrogen, ammonia, dissolved nitrite plus nitrate, total phosphorus, and orthophosphate; and for metals, including total recoverable and dissolved phases of copper, lead, manganese, and zinc. Samples collected during selected storms were also analyzed for bacteriological indicators such as Escherichia coli and fecal coliform at the Metro Wastewater Reclamation Laboratory. About 200 stormwater samples collected during storms characterize the quality of storm runoff during 2006-2010. In general, the quality of stormwater (2006-2010) has improved for many water-quality constituents, many of which had lower values and concentrations than those in stormwater collected in 2002-2005. However, the physical basis, processes, and the role of dilution that account for these changes are complex and beyond the scope of this report. The water-quality sampling results indicate few exceptions to standards except for dissolved manganese, dissolved zinc, and Escherichia coli. Stormwater collected at the South Platte River below Union Avenue station had about 10 percent acute or chronic dissolved manganese exceedances in samples; samples collected at the South Platte River at Denver station had less than 5 percent acute or chronic dissolved manganese exceedances. In contrast, samples collected at Toll Gate Creek above 6th Avenue at Aurora station, Sand Creek at mouth near Commerce City station, and the South Platte River at Henderson station, each had about 30 to 50 percent exceedances of both acute and chronic dissolved manganese standards. Of the samples collected at Sand Creek at mouth near Commerce City, 1 sample exceeded the acute standard and 4 samples exceeded the chronic standard for dissolved zinc, but no samples collected from the other sites exceeded either standard for zinc. Almost all samples of stormwater analyzed for Escherichia coli exceeded Colorado numeric standards. A numerical standard for fecal coliform is no longer applicable as of 2004. Results from the 2002-2005 study indicated that the general quality of stormwater had improved during 2002-2005 compared to 1998-2001, having fewer exceedances of Colorado standards, and showing downward trends for many water-quality values and concentrations. These trends coincided with general downward or relatively similar mean streamflows for the 2002-2005 compared to 1998-2001, which indicates that dilution may be a smaller influence on values and concentrations than other factors. For this report, downward trends were indicated for many constituents at each station during 2006-2010 compared to 2002-2005. The trends for mean streamflow for 2006-2010 compared to 2002-2005 are upward at all sites except for the South Platte River at Henderson, indicating that dilution by larger flows could be a factor in the downward concentration trends. At the South Platte River below Union Avenue station, downward trends were indicated for hardness, dissolved ammonia, dissolved orthophosphate, and dissolved copper. Upward trends at South Platte River below Union Avenue were indicated for pH. At the South Platte River at Denver station, downward trends were indicated for total ammonia plus organic nitrogen, dissolved ammonia, dissolved nitrite plus nitrate, dissolved orthophosphate, total phosphorus, dissolved organic carbon, and dissolved lead, manganese, and zinc, and total recoverable zinc. An upward trend in properties and constituents at South Platte River at Denver was indicated for pH. At Toll Gate Creek above 6th Avenue at Aurora, downward trends were indicated for residue on evaporation, total ammonia plus organic nitrogen, dissolved ammonia, dissolved orthophosphate, total phosphorus, and total recoverable copper, lead, manganese, and zinc. Upward trends in properties and constituents at Toll Gate Creek above 6th Avenue at Aurora were indicated for pH, specific conductance, and dissolved nitrite plus nitrate. At Sand Creek at mouth near Commerce City, downward trends were indicated for hardness, dissolved calcium, total ammonia plus organic nitrogen, and dissolved ammonia, orthophosphate, manganese, and zinc. An upward trend in properties and constituents at Sand Creek at mouth near Commerce City was indicated for pH. Downward trends at South Platte River at Henderson were indicated for specific conductance, hardness, dissolved magnesium, residue on evaporation, total ammonia plus organic nitrogen, dissolved ammonia, dissolved nitrite plus nitrate, dissolved orthophosphate, total phosphorus, dissolved lead and manganese, and total recoverable copper, lead, manganese, and zinc.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19..807P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19..807P"><span>Streamflow loss quantification for groundwater flow modeling using a wading-rod-mounted acoustic Doppler current profiler in a headwater stream</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pflügl, Christian; Hoehn, Philipp; Hofmann, Thilo</p> <p>2017-04-01</p> <p>Irrespective of the availability of various field measurement and modeling approaches, the quantification of interactions between surface water and groundwater systems remains associated with high uncertainty. Such uncertainties on stream-aquifer interaction have a high potential to misinterpret the local water budget and water quality significantly. Due to typically considerable temporal variation of stream discharge rates, it is desirable for the measurement of streamflow to reduce the measuring duration while reducing uncertainty. Streamflow measurements, according to the velocity-area method, have been performed along reaches of a losing-disconnected, subalpine headwater stream using a 2-dimensional, wading-rod-mounted acoustic Doppler current profiler (ADCP). The method was chosen, with stream morphology not allowing for boat-mounted setups, to reduce uncertainty compared to conventional, single-point streamflow measurements of similar measurement duration. Reach-averaged stream loss rates were subsequently quantified between 12 cross sections. They enabled the delineation of strongly infiltrating stream reaches and their differentiation from insignificantly infiltrating reaches. Furthermore, a total of 10 near-stream observation wells were constructed and/or equipped with pressure and temperature loggers. The time series of near-stream groundwater temperature data were cross-correlated with stream temperature time series to yield supportive qualitative information on the delineation of infiltrating reaches. Subsequently, as a reference parameterization, the hydraulic conductivity and specific yield of a numerical, steady-state model of groundwater flow, in the unconfined glaciofluvial aquifer adjacent to the stream, were inversely determined incorporating the inferred stream loss rates. Applying synthetic sets of infiltration rates, resembling increasing levels of uncertainty associated with single-point streamflow measurements of comparable duration, the same inversion procedure was run. The volume-weighted mean of the respective parameter distribution within 200 m of stream periphery deviated increasingly from the reference parameterization at increasing deviation of infiltration rates.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AtmEn.146..195K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AtmEn.146..195K"><span>Long-term response of surface water acid neutralizing capacity in a central Appalachian (USA) river basin to declining acid deposition</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kline, Kathleen M.; Eshleman, Keith N.; Garlitz, James E.; U'Ren, Sarah H.</p> <p>2016-12-01</p> <p>Long-term changes in acid-base chemistry resulting from declining regional acid deposition were examined using data from repeating synoptic surveys conducted within the 275 km2 Upper Savage River Watershed (USRW) in western Maryland (USA); a randomly-selected set of 40 stream reaches was sampled 36 times between 1999 and 2014 to: (1) repeatedly characterize the acid-base status of the entire river basin; (2) determine whether an extensive network of streams of varying order has shown signs of recovery in acid neutralizing capacity (ANC); and (3) understand the key factors controlling the rate of ANC recovery across the river network. Several non-parametric analyses of trends (i.e., Mann Kendall Trend: MKT tests; and Regional Kendall Trend: RKT) in streamwater acid-base chemistry suggest that USRW has significantly responded to declining acid deposition during the study period; the two most robust, statistically significant trends were decreasing surface water SO42- (∼1.5 μeq L-1 yr-1) and NO3- (∼1 μeq L-1 yr-1) concentrations-consistent with observed downward trends in regional wet S and N deposition. Basin-wide decreasing trends in K+, Mg2+, and Ca2+ were also observed, while Na+ concentrations increased. Significant ANC recovery was observed in 10-20% of USRW stream reaches (depending on the p level used), but the magnitude of the trend relative to natural variability was apparently insufficient to allow detection of a basin-wide ANC trend using the RKT test. Watershed factors, such as forest disturbances and increased application of road deicing salts, appeared to contribute to substantial variability in concentrations of NO3- and Na+ in streams across the basin, but these factors did not affect our overall interpretation of the results as a systematic recovery of USRW from regional acidification. Methodologically, RKT appears to be a robust method for identifying basin-wide trends using synoptic data, but MKT results for individual systems should be examined closely (e.g., to identify trends for specific subpopulations).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMEP51A0703R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMEP51A0703R"><span>Understanding Stream Channel Sediment Source Contributions For The Paradise Creek Watershed In Northern Idaho</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rittenburg, R.; Boll, J.; Brooks, E. S.</p> <p>2013-12-01</p> <p>Excess sediment from agricultural areas has been a major source of impairment for water bodies, resulting in the implementation of mitigation measures across landscapes. Watershed scale reductions often target upland erosion as key non-point sources for sediment loading. Stream channel dynamics, however, also play a contributing role in sediment loading in the form of legacy sediments, channel erosion and deposition, and buffering during storm events. In-stream contributions are not well understood, and are a potentially important consideration for Total Maximum Daily Loads (TMDLs). The objective of this study is to differentiate stream bank and stream bed sediment contributions and better understand the role of legacy sediments. The study area is the Paradise Creek Watershed in northern Idaho. We modeled sediment yield to the channel system using the Water Erosion Prediction Project (WEPP) model, and subsequent channel erosion and deposition using CONCEPTs. Field observations of cross-sections along the channel system over a 5-year period were collected to verify model simulations and to test the hypothesis that the watershed load was composed predominantly of legacy sediments. Our modeling study shows that stream channels contributed to 39% of the total annual sediment load for the basin, with a 19-year time lag between sediments entering the stream to leaving the watershed outlet. Observations from long-term cross sectional data in the watershed, and a sediment fingerprinting analysis will be presented to better understand sediment contributions from within the stream channel system.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018DDA....4930302N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018DDA....4930302N"><span>Reconstructing the Dwarf Galaxy Progenitor from Tidal Streams Using MilkyWay@home</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Newberg, Heidi; Shelton, Siddhartha</p> <p>2018-04-01</p> <p>We attempt to reconstruct the mass and radial profile of stars and dark matter in the dwarf galaxy progenitor of the Orphan Stream, using only information from the stars in the Orphan Stream. We show that given perfect data and perfect knowledge of the dwarf galaxy profile and Milky Way potential, we are able to reconstruct the mass and radial profiles of both the stars and dark matter in the progenitor to high accuracy using only the density of stars along the stream and either the velocity dispersion or width of the stream in the sky. To perform this test, we simulated the tidal disruption of a two component (stars and dark matter) dwarf galaxy along the orbit of the Orphan Stream. We then created a histogram of the density of stars along the stream and a histogram of either the velocity dispersion or width of the stream in the sky as a function of position along the stream. The volunteer supercomputer MilkyWay@home was given these two histograms, the Milky Way potential model, and the orbital parameters for the progenitor. N-body simulations were run, varying dwarf galaxy parameters and the time of disruption. The goodness-of-fit of the model to the data was determined using an Earth-Mover Distance algorithm. The parameters were optimized using Differential Evolution. Future work will explore whether currently available information on the Orphan Stream stars is sufficient to constrain its progenitor, and how sensitive the optimization is to our knowledge of the Milky Way potential and the density model of the dwarf galaxy progenitor, as well as a host of other real-life unknowns.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Geomo.236...44L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Geomo.236...44L"><span>Sources of fine sediment stored in agricultural lowland streams, Midwest, USA</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lamba, Jasmeet; Thompson, A. M.; Karthikeyan, K. G.; Fitzpatrick, Faith A.</p> <p>2015-05-01</p> <p>Agricultural activities can accelerate the offsite transport of productive soil from fields leading to stream water quality degradation. Identification of the nature and relative contribution of different sources to fine-grained sediment (e.g., silts, clays) in streams is important to effectively focus agricultural best management practices in watersheds. Sediment fingerprinting techniques through the use of geochemical tracers are commonly used to differentiate relative contribution from various sources. Research was conducted in lowland streams in the Pleasant Valley watershed in South Central Wisconsin (USA) to identify provenance of fine-grained sediment deposits and evaluate the impact of land use on relative contributions from the following potential sources: cropland, pasture, woodland, and eroding stream banks. Results show that both agriculture (croplands and pastures) and eroding stream banks are primary sources to fine sediment deposits on the stream bed with contributions ranging from 19 to 100% and 0 to 81%, respectively. The increase in area under agricultural land use within a subwatershed results in greater contribution from agriculture (R2 = 0.846, p = 0.0034). Relative contributions from eroding stream banks increased with increasing area under grasslands and woodlands within a subwatershed (R2 = 0.814, p = 0.0055). Subwatersheds with greater mass of fine sediment deposited on the stream bed per unit area should be prioritized for best management practices. The conservation practices should be targeted to stream banks or croplands depending on the dominant source of fine sediment within a subwatershed. Site specific changes in relative contributions from different sources to fine-grained sediment in this watershed highlights the complexities involved in sediment transport dynamics. The nested sampling sites helped determine that sediment dynamics at the subwatershed scale need to be considered for application of targeted conservation techniques.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70193932','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70193932"><span>Sources of fine sediment stored in agricultural lowland streams, Midwest, USA</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Lamba, Jasmeet; Thompson, Anita M.; Karthikeyan, K.G.; Fitzpatrick, Faith A.</p> <p>2015-01-01</p> <p>Agricultural activities can accelerate the offsite transport of productive soil from fields leading to stream water quality degradation. Identification of the nature and relative contribution of different sources to fine-grained sediment (e.g., silts, clays) in streams is important to effectively focus agricultural best management practices in watersheds. Sediment fingerprinting techniques through the use of geochemical tracers are commonly used to differentiate relative contribution from various sources. Research was conducted in lowland streams in the Pleasant Valley watershed in South Central Wisconsin (USA) to identify provenance of fine-grained sediment deposits and evaluate the impact of land use on relative contributions from the following potential sources: cropland, pasture, woodland, and eroding stream banks. Results show that both agriculture (croplands and pastures) and eroding stream banks are primary sources to fine sediment deposits on the stream bed with contributions ranging from 19 to 100% and 0 to 81%, respectively. The increase in area under agricultural land use within a subwatershed results in greater contribution from agriculture (R2 = 0.846, p = 0.0034). Relative contributions from eroding stream banks increased with increasing area under grasslands and woodlands within a subwatershed (R2 = 0.814, p = 0.0055). Subwatersheds with greater mass of fine sediment deposited on the stream bed per unit area should be prioritized for best management practices. The conservation practices should be targeted to stream banks or croplands depending on the dominant source of fine sediment within a subwatershed. Site specific changes in relative contributions from different sources to fine-grained sediment in this watershed highlights the complexities involved in sediment transport dynamics. The nested sampling sites helped determine that sediment dynamics at the subwatershed scale need to be considered for application of targeted conservation techniques.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PApGe.tmp.1282W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PApGe.tmp.1282W"><span>A Constrained Scheme for High Precision Downward Continuation of Potential Field Data</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Jun; Meng, Xiaohong; Zhou, Zhiwen</p> <p>2018-04-01</p> <p>To further improve the accuracy of the downward continuation of potential field data, we present a novel constrained scheme in this paper combining the ideas of the truncated Taylor series expansion, the principal component analysis, the iterative continuation and the prior constraint. In the scheme, the initial downward continued field on the target plane is obtained from the original measured field using the truncated Taylor series expansion method. If the original field was with particularly low signal-to-noise ratio, the principal component analysis is utilized to suppress the noise influence. Then, the downward continued field is upward continued to the plane of the prior information. If the prior information was on the target plane, it should be upward continued over a short distance to get the updated prior information. Next, the difference between the calculated field and the updated prior information is calculated. The cosine attenuation function is adopted to get the scope of constraint and the corresponding modification item. Afterward, a correction is performed on the downward continued field on the target plane by adding the modification item. The correction process is iteratively repeated until the difference meets the convergence condition. The accuracy of the proposed constrained scheme is tested on synthetic data with and without noise. Numerous model tests demonstrate that downward continuation using the constrained strategy can yield more precise results compared to other downward continuation methods without constraints and is relatively insensitive to noise even for downward continuation over a large distance. Finally, the proposed scheme is applied to real magnetic data collected within the Dapai polymetallic deposit from the Fujian province in South China. This practical application also indicates the superiority of the presented scheme.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70193819','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70193819"><span>Hydrological and geophysical investigation of streamflow losses and restoration strategies in an abandoned mine lands setting</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Cravotta, Charles A.; Sherrod, Laura; Galeone, Daniel G.; Lehman, Wayne G.; Ackman, Terry E.; Kramer, Alexa</p> <p>2017-01-01</p> <p>Longitudinal discharge and water-quality campaigns (seepage runs) were combined with surface-geophysical surveys, hyporheic-temperature profiling, and watershed-scale hydrological monitoring to evaluate the locations, magnitude, and impact of streamwater losses from the West Creek subbasin of the West West Branch Schuylkill River into the underground Oak Hill Mine complex that extends beneath the watershed divide. Abandoned mine drainage (AMD), containing iron and other contaminants, from the Oak Hill Boreholes to the West Branch Schuylkill River was sustained during low-flow conditions and correlated to streamflow lost through the West Creek streambed. During high-flow conditions, streamflow was transmitted throughout West Creek; however, during low-flow conditions, all streamflow from the perennial headwaters was lost within the 300-to-600-m "upper reach" where an 1889 mine map indicated steeply dipping coalbeds underlie the channel. During low-flow conditions, the channel within the "intermediate reach" 700-to-1650-m downstream gained groundwater seepage with higher pH and specific conductance than upstream; however, all streamflow 1650-to-2050-m downstream was lost to underlying mines. Electrical resistivity and electromagnetic conductivity surveys indicated conductive zones beneath the upper reach, where flow loss occurred, and through the intermediate reach, where gains and losses occurred. Temperature probes at 0.06-to-0.10-m depth within the hyporheic zone of the intermediate reach indicated potential downward fluxes as high as 2.1x10-5 m/s. Cumulative streamflow lost from West Creek during seepage runs averaged 53.4 L/s, which equates to 19.3 percent of the daily average discharge of AMD from the Oak Hill Boreholes and a downward flux of 1.70x10-5 m/s across the 2.1-km-by-1.5-m West Creek stream-channel area.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MNRAS.462.2739K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MNRAS.462.2739K"><span>Rapid approach to the quantitative determination of nocturnal ground irradiance in populated territories: a clear-sky case</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kocifaj, Miroslav; Petržala, Jaromír</p> <p>2016-11-01</p> <p>A zero-order approach to the solving of the radiative transfer equation and a method for obtaining the horizontal diffuse irradiance at night-time are both developed and intended for wide use in numerical predictions of nocturnal ground irradiance in populated territories. Downward diffuse radiative fluxes are computed with a two-stream approximation, and the data products obtained are useful for scientists who require rapid estimations of illumination levels during the night. The rapid technique presented here is especially important when the entire set of calculations is to be repeated for different lighting technologies and/or radiant intensity distributions with the aim of identifying high-level illuminance/irradiance, the spectral composition of scattered light or other optical properties of diffuse light at the ground level. The model allows for the computation of diffuse horizontal irradiance due to light emissions from ground-based sources with arbitrary spectral compositions. The optical response of a night sky is investigated using the ratio of downward to upward irradiance, R⊥, λ(0). We show that R⊥, λ(0) generally peaks at short wavelengths, thus suggesting that, e.g., the blue light of an LED lamp would make the sky even more bluish. However, this effect can be largely suppressed or even removed with the spectral sensitivity function of the average human eye superimposed on to the lamp spectrum. Basically, blue light scattering dominates at short optical distances, while red light is transmitted for longer distances and illuminates distant places. Computations are performed for unshielded as well as fully shielded lights, while the spectral function R⊥, λ(0) is tabulated to make possible the modelling of various artificial lights, including those not presented here.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JASTP..71..717L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JASTP..71..717L"><span>Poker flat radar observations of the magnetosphere-ionosphere coupling electrodynamics of the earthward penetrating plasma sheet following convection enhancements</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lyons, L. R.; Zou, S.; Heinselman, C. J.; Nicolls, M. J.; Anderson, P. C.</p> <p>2009-05-01</p> <p>The plasma sheet moves earthward (equatorward in the ionosphere) after enhancements in convection, and the electrodynamics of this response is strongly influenced by Region 2 magnetosphere-ionosphere coupling. We have used Poker Flat Advanced Modular Incoherent Scatter Radar (PFISR) observations associated with two relatively abrupt southward turnings of the IMF to provide an initial evaluation of aspects of this response. The observations show that strong westward sub-auroral polarization streams (SAPS) flow regions moved equatorward as the plasma sheet electron precipitation (the diffuse aurora) penetrated equatorward following the IMF southward turnings. Consistent with our identification of these flows as SAPS, concurrent DMSP particle precipitation measurements show the equatorial boundary of ion precipitation equatorward of the electron precipitation boundary and that westward flows lie within the low-conductivity region between the two boundaries where the plasma sheet ion pressure gradient is expected to drive downward R2 currents. Evidence for these downward currents is seen in the DMSP magnetometer observations. Preliminary examination indicates that the SAPS response seen in the examples presented here may be common. However, detailed analysis will be required for many more events to reliably determine if this is the case. If so, it would imply that SAPS are frequently an important aspect of the inner magnetospheric electric field distribution, and that they are critical for understanding the response of the magnetosphere-ionosphere system to enhancements in convection, including understanding the earthward penetration of the plasma sheet. This earthward penetration is critical to geomagnetic disturbance phenomena such as the substorm growth phase and the formation of the stormtime ring current. Additionally, for one example, a prompt electric field response to the IMF southward turnings is seen within the inner plasma sheet.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017RSPTA.37560338F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017RSPTA.37560338F"><span>Coarse-graining as a downward causation mechanism</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Flack, Jessica C.</p> <p>2017-11-01</p> <p>Downward causation is the controversial idea that `higher' levels of organization can causally influence behaviour at `lower' levels of organization. Here I propose that we can gain traction on downward causation by being operational and examining how adaptive systems identify regularities in evolutionary or learning time and use these regularities to guide behaviour. I suggest that in many adaptive systems components collectively compute their macroscopic worlds through coarse-graining. I further suggest we move from simple feedback to downward causation when components tune behaviour in response to estimates of collectively computed macroscopic properties. I introduce a weak and strong notion of downward causation and discuss the role the strong form plays in the origins of new organizational levels. I illustrate these points with examples from the study of biological and social systems and deep neural networks. This article is part of the themed issue 'Reconceptualizing the origins of life'.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5686398','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5686398"><span>Coarse-graining as a downward causation mechanism</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2017-01-01</p> <p>Downward causation is the controversial idea that ‘higher’ levels of organization can causally influence behaviour at ‘lower’ levels of organization. Here I propose that we can gain traction on downward causation by being operational and examining how adaptive systems identify regularities in evolutionary or learning time and use these regularities to guide behaviour. I suggest that in many adaptive systems components collectively compute their macroscopic worlds through coarse-graining. I further suggest we move from simple feedback to downward causation when components tune behaviour in response to estimates of collectively computed macroscopic properties. I introduce a weak and strong notion of downward causation and discuss the role the strong form plays in the origins of new organizational levels. I illustrate these points with examples from the study of biological and social systems and deep neural networks. This article is part of the themed issue ‘Reconceptualizing the origins of life’. PMID:29133440</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998GeoRL..25.2033E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998GeoRL..25.2033E"><span>The auroral current circuit and field-aligned currents observed by FAST</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Elphic, R. C.; Bonnell, J. W.; Strangeway, R. J.; Kepko, L.; Ergun, R. E.; McFadden, J. P.; Carlson, C. W.; Peria, W.; Cattell, C. A.; Klumpar, D.; Shelley, E.; Peterson, W.; Moebius, E.; Kistler, L.; Pfaff, R.</p> <p></p> <p>FAST observes signatures of small-scale downward-going current at the edges of the inverted-V regions where the primary (auroral) electrons are found. In the winter pre-midnight auroral zone these downward currents are carried by upward flowing low- and medium-energy (up to several keV) electron beams. FAST instrumentation shows agreement between the current densities inferred from both the electron distributions and gradients in the magnetic field. FAST data taken near apogee (˜4000-km altitude) commonly show downward current magnetic field deflections consistent with the observed upward flux of ˜109 electrons cm-2 s-1, or current densities of several µA m-2. The electron, field-aligned current and electric field signatures indicate the downward currents may be associated with “black aurora” and auroral ionospheric cavities. The field-aligned voltage-current relationship in the downward current region is nonlinear.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10550622','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10550622"><span>Relocalization of the calcium gradient and a dihydropyridine receptor is involved in upward bending by bulging of Chara protonemata, but not in downward bending by bowing of Chara rhizoids.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Braun, M; Richter, P</p> <p>1999-10-01</p> <p>The localization of cytoplasmic free calcium and a dihydropyridine (DHP) receptor, a putative calcium channel, was recorded during the opposite graviresponses of tip-growing Chara rhizoids and Chara protonemata by using the calcium indicator Calcium Crimson and a fluorescently labeled dihydropyridine (FL-DHP). In upward (negatively gravitropically) growing protonemata and downward (positively gravitropically) growing rhizoids, a steep Ca2+ gradient and DHP receptors were found to be symmetrically localized in the tip. However, the localization of the Ca2+ gradient and DHP receptors differed considerably during the gravitropic responses upon horizontal positioning of the two cell types. During the graviresponse of rhizoids, a continuous bowing downward by differential flank growth, the Ca2+ gradient and DHP receptors remained symmetrically localized in the tip at the centre of growth. However, after tilting protonemata into a horizontal position, there was a drastic displacement of the Ca2+ gradient and FL-DHP to the upper flank of the apical dome. This displacement occurred after the apical intrusion and sedimentation of the statoliths but clearly before the change in the growth direction became evident. In protonemata, the reorientation of the growth direction started with the appearance of a bulge on that site of the upper flank which was predicted by the asymmetrically displaced Ca2+ gradient. With the upward shift of the cell tip, which is suggested to result from a statolith-induced displacement of the growth centre, the Ca2+ gradient and DHP receptors became symmetrically relocalized in the apical dome. No major asymmetrical rearrangement was observed during the following phase of gravitropic curvature which is characterized by slower rates of bending. Labeling with FL-DHP was completely inhibited by a non-fluorescently labeled dihydropyridine. From these results it is suggested that FL-DHP labels calcium channels in rhizoids and protonemata. In rhizoids, positive gravitropic curvature is caused by differential growth limited to the opposite subapical flanks of the apical dome, a process which does not involve displacement of the growth centre, the calcium gradient or calcium channels. In protonemata, however, it is proposed that a statolith-induced asymmetrical relocalization of calcium channels and the Ca2+ gradient precedes, and might mediate, the rearrangement of the centre of growth, most likely by the displacement of the Spitzenkorper, to the upper flank, which results in the negative gravitropic reorientation of the growth direction.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2014/5136/pdf/sir20145136.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2014/5136/pdf/sir20145136.pdf"><span>Simulation of groundwater flow and the interaction of groundwater and surface water in the Willamette Basin and Central Willamette subbasin, Oregon</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Herrera, Nora B.; Burns, Erick R.; Conlon, Terrence D.</p> <p>2014-01-01</p> <p>Full appropriation of tributary streamflow during summer, a growing population, and agricultural needs are increasing the demand for groundwater in the Willamette Basin. Greater groundwater use could diminish streamflow and create seasonal and long-term declines in groundwater levels. The U.S. Geological Survey (USGS) and the Oregon Water Resources Department (OWRD) cooperated in a study to develop a conceptual and quantitative understanding of the groundwater-flow system of the Willamette Basin with an emphasis on the Central Willamette subbasin. This final report from the cooperative study describes numerical models of the regional and local groundwater-flow systems and evaluates the effects of pumping on groundwater and surface‑water resources. The models described in this report can be used to evaluate spatial and temporal effects of pumping on groundwater, base flow, and stream capture. The regional model covers about 6,700 square miles of the 12,000-square mile Willamette and Sandy River drainage basins in northwestern Oregon—referred to as the Willamette Basin in this report. The Willamette Basin is a topographic and structural trough that lies between the Coast Range and the Cascade Range and is divided into five sedimentary subbasins underlain and separated by basalts of the Columbia River Basalt Group (Columbia River basalt) that crop out as local uplands. From north to south, these five subbasins are the Portland subbasin, the Tualatin subbasin, the Central Willamette subbasin, the Stayton subbasin, and the Southern Willamette subbasin. Recharge in the Willamette Basin is primarily from precipitation in the uplands of the Cascade Range, Coast Range, and western Cascades areas. Groundwater moves downward and laterally through sedimentary or basalt units until it discharges locally to wells, evapotranspiration, or streams. Mean annual groundwater withdrawal for water years 1995 and 1996 was about 400 cubic feet per second; irrigation withdrawals accounted for about 80 percent of that total. The upper 180 feet of productive aquifers in the Central Willamette and Southern Willamette subbasins produced about 70 percent of the total pumped volume. In this study, the USGS constructed a three-dimensional numerical finite-difference groundwater-flow model of the Willamette Basin representing the six hydrogeologic units, defined in previous investigations, as six model layers. From youngest to oldest, and [generally] uppermost to lowermost they are the: upper sedimentary unit, Willamette silt unit, middle sedimentary unit, lower sedimentary unit, Columbia River basalt unit, and basement confining unit. The high Cascade unit is not included in the groundwater-flow model because it is not present within the model boundaries. Geographic boundaries are simulated as no-flow (no water flowing in or out of the model), except where the Columbia River is simulated as a constant hydraulic head boundary. Streams are designated as head-dependent-flux boundaries, in which the flux depends on the elevation of the stream surface. Groundwater recharge from precipitation was estimated using the Precipitation-Runoff Modeling System (PRMS), a watershed model that accounts for evapotranspiration from the unsaturated zone. Evapotranspiration from the saturated zone was not considered an important component of groundwater discharge. Well pumping was simulated as specified flux and included public supply, irrigation, and industrial pumping. Hydraulic conductivity values were estimated from previous studies through aquifer slug and permeameter tests, specific capacity data, core analysis, and modeling. Upper, middle and lower sedimentary unit horizontal hydraulic conductivity values were differentiated between the Portland subbasin and the Tualatin, Central Willamette, and Southern Willamette subbasins based on preliminary model results.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19780020088','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19780020088"><span>A three-dimensional model of corotating streams in the solar wind. 1: Theoretical foundations</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pizzo, V. J.</p> <p>1978-01-01</p> <p>The theoretical and mathematical background pertinent to the study of steady, corotating solar wind structure in all three spatial dimensions (3-D) is discussed. The dynamical evolution of the plasma in interplanetary space (defined as the region beyond roughly 35 solar radii where the flow is supersonic) is approximately described by the nonlinear, single fluid, polytropic (magneto-) hydrodynamic equations. Efficient numerical techniques for solving this complex system of coupled, hyperbolic partial differential equations are outlined. The formulation is inviscid and nonmagnetic, but methods allow for the potential inclusion of both features with only modest modifications. One simple, highly idealized, hydrodynamic model stream is examined to illustrate the fundamental processes involved in the 3-D dynamics of stream evolution. Spatial variations in the rotational stream interaction mechanism were found to produce small nonradial flows on a global scale that lead to the transport of mass, energy, and momentum away from regions of relative compression and into regions of relative rarefaction.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70185218','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70185218"><span>Temporal variation in phenotypic and genotypic traits in two sockeye salmon populations, Tustumena Lake, Alaska</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Woody, Carol Ann; Olsen, Jeffrey B.; Reynolds, Joel H.; Bentzen, Paul</p> <p>2000-01-01</p> <p>Sockeye salmon Oncorhynchus nerka in two tributary streams (about 20 km apart) of the same lake were compared for temporal variation in phenotypic (length, depth adjusted for length) and genotypic (six microsatellite loci) traits. Peak run time (July 16 versus 11 August) and run duration (43 versus 26 d) differed between streams. Populations were sampled twice, including an overlapping point in time. Divergence at microsatellite loci followed a temporal cline: Population sample groups collected at the same time were not different (F ST = 0), whereas those most separated in time were different (F ST = 0.011, P = 0.001). Although contemporaneous sample groups did not differ significantly in microsatellite genotypes (F ST = 0), phenotypic traits did differ significantly (MANOVA, P < 0.001). Fish from the larger stream were larger; fish from the smaller stream were smaller, suggesting differential fitness related to size. Results indicate run time differences among and within sockeye salmon populations may strongly influence levels of gene flow.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PlST...20c5002A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PlST...20c5002A"><span>Influence of two-stream relativistic electron beam parameters on the space-charge wave with broad frequency spectrum formation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alexander, LYSENKO; Iurii, VOLK</p> <p>2018-03-01</p> <p>We developed a cubic non-linear theory describing the dynamics of the multiharmonic space-charge wave (SCW), with harmonics frequencies smaller than the two-stream instability critical frequency, with different relativistic electron beam (REB) parameters. The self-consistent differential equation system for multiharmonic SCW harmonic amplitudes was elaborated in a cubic non-linear approximation. This system considers plural three-wave parametric resonant interactions between wave harmonics and the two-stream instability effect. Different REB parameters such as the input angle with respect to focusing magnetic field, the average relativistic factor value, difference of partial relativistic factors, and plasma frequency of partial beams were investigated regarding their influence on the frequency spectrum width and multiharmonic SCW saturation levels. We suggested ways in which the multiharmonic SCW frequency spectrum widths could be increased in order to use them in multiharmonic two-stream superheterodyne free-electron lasers, with the main purpose of forming a powerful multiharmonic electromagnetic wave.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUSMNB33Q..05H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUSMNB33Q..05H"><span>The Effects of Amphibian Extirpations on Foodweb Structure and Function in Panamanian Highland Streams.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hunte-Brown, M. E.; Kilham, S. S.; Whiles, M. R.; Lips, K.; Pringle, C.; Colon, C.; Brenes, R.; Connelly, S.</p> <p>2005-05-01</p> <p>Amphibian populations are declining globally in uplands. Stream-dwelling tadpoles are potentially important herbivores, and their loss is expected to cause significant changes in structure and function of lotic ecosystems. This study is part of a collaborative effort to measure changes in trophic structure associated with amphibian extirpations. We used stable isotopes to elucidate trends in Panamanian highland streams at two locations, El Cope and Fortuna, which are differentially affected by the declines. Generally, the nitrogen source in the Fortuna stream, where amphibians have already declined, is primarily atmospheric, whereas it is more recycled in El Cope where tadpoles are still abundant. FBOM is an important food resource in El Cope, and because of the recycled N from tadpole feces, the delta N15 values of the periphyton are higher in the pools than in the riffles in El Cope. Generally, the delta N15 signal of similar trophic groups is lower at Fortuna than at El Cope. The delta N15 signals also tend to fall with increased rainfall. Leaf packs are apparently under-utilized in these systems. Results allow for an assessment of trophic structure in highland neotropical streams and suggest that stream-breeding anuran extirpations may alter nutrient cycling and energy flow.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29046542','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29046542"><span>Decadal ecosystem response to an anomalous melt season in a polar desert in Antarctica.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gooseff, Michael N; Barrett, John E; Adams, Byron J; Doran, Peter T; Fountain, Andrew G; Lyons, W Berry; McKnight, Diane M; Priscu, John C; Sokol, Eric R; Takacs-Vesbach, Cristina; Vandegehuchte, Martijn L; Virginia, Ross A; Wall, Diana H</p> <p>2017-09-01</p> <p>Amplified climate change in polar regions is significantly altering regional ecosystems, yet there are few long-term records documenting these responses. The McMurdo Dry Valleys (MDV) cold desert ecosystem is the largest ice-free area of Antarctica, comprising soils, glaciers, meltwater streams and permanently ice-covered lakes. Multi-decadal records indicate that the MDV exhibited a distinct ecosystem response to an uncharacteristic austral summer and ensuing climatic shift. A decadal summer cooling phase ended in 2002 with intense glacial melt ('flood year')-a step-change in water availability triggering distinct changes in the ecosystem. Before 2002, the ecosystem exhibited synchronous behaviour: declining stream flow, decreasing lake levels, thickening lake ice cover, decreasing primary production in lakes and streams, and diminishing soil secondary production. Since 2002, summer air temperatures and solar flux have been relatively consistent, leading to lake level rise, lake ice thinning and elevated stream flow. Biological responses varied; one stream cyanobacterial mat type immediately increased production, but another stream mat type, soil invertebrates and lake primary productivity responded asynchronously a few years after 2002. This ecosystem response to a climatic anomaly demonstrates differential biological community responses to substantial perturbations, and the mediation of biological responses to climate change by changes in physical ecosystem properties.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/wri/2000/4141/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/wri/2000/4141/report.pdf"><span>Determination of infiltration and percolation rates along a reach of the Santa Fe River near La Bajada, New Mexico</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Thomas, Carole L.; Stewart, Amy E.; Constantz, Jim E.</p> <p>2000-01-01</p> <p>Two methods, one a surface-water method and the second a ground-water method, were used to determine infiltration and percolation rates along a 2.5-kilometer reach of the Santa Fe River near La Bajada, New Mexico. The surface-water method uses streamflow measurements and their differences along a stream reach, streamflow-loss rates, stream surface area, and evaporation rates to determine infiltration rates. The ground-water method uses heat as a tracer to monitor percolation through shallow streambed sediments. Data collection began in October 1996 and continued through December 1997. During that period the stream reach was instrumented with three streamflow gages, and temperature profiles were monitored from the stream-sediment interface to about 3 meters below the streambed at four sites along the reach. Infiltration is the downward flow of water through the stream- sediment interface. Infiltration rates ranged from 92 to 267 millimeters per day for an intense measurement period during June 26- 28, 1997, and from 69 to 256 millimeters per day during September 27-October 6, 1997. Investigators calculated infiltration rates from streamflow loss, stream surface-area measurements, and evaporation-rate estimates. Infiltration rates may be affected by unmeasured irrigation-return flow in the study reach. Although the amount of irrigation-return flow was none to very small, it may result in underestimation of infiltration rates. The infiltration portion of streamflow loss was much greater than the evaporation portion. Infiltration accounted for about 92 to 98 percent of streamflow loss. Evaporation-rate estimates ranged from 3.4 to 7.6 millimeters per day based on pan-evaporation data collected at Cochiti Dam, New Mexico, and accounted for about 2 to 8 percent of streamflow loss. Percolation is the movement of water through saturated or unsaturated sediments below the stream-sediment interface. Percolation rates ranged from 40 to 109 millimeters per day during June 26-28, 1997. Percolation rates were not calculated for the September 27-October 6, 1997, period because a late summer flood removed the temperature sensors from the streambed. Investigators used a heat-and-water flow model, VS2DH (variably saturated, two- dimensional heat), to calculate near-surface streambed infiltration and percolation rates from temperatures measured in the stream and streambed. Near the stream-sediment interface, infiltration and percolation rates are comparable. Comparison of infiltration and percolation rates showed that infiltration rates were greater than percolation rates. The method used to calculate infiltration rates accounted for net loss or gain over the entire stream reach, whereas the method used to calculate percolation was dependent on point measurements and, as applied in this study, neglected the nonvertical component of heat and water fluxes. In general, using the ground-water method was less labor intensive than making a series of streamflow measurements and relied on temperature, an easily measured property. The ground-water method also eliminated the difficulty of measuring or estimating evaporation from the water surface and was therefore more direct. Both methods are difficult to use during periods of flood flow. The ground-water method has problems with the thermocouple-wire temperature sensors washing out during flood events. The surface- water method often cannot be used because of safety concerns for personnel making wading streamflow measurements.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70029666','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70029666"><span>Effects of urban development in the Puget Lowland, Washington, on interannual streamflow patterns: Consequences for channel form and streambed disturbance</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Konrad, Christopher P.; Booth, Derek B.; Burges, Stephen J.</p> <p>2005-01-01</p> <p>Recovery and protection of streams in urban areas depend on a comprehensive understanding of how human activities affect stream ecosystems. The hydrologic effects of urban development and the consequences for stream channel form and streambed stability were examined in 16 streams in the Puget Lowland, Washington, using three streamflow metrics that integrate storm‐scale effects of urban development over annual to decadal timescales: the fraction of time that streamflow exceeds the mean streamflow (TQmean), the coefficient of variation of annual maximum streamflow (CVAMF), and the fraction of time that streamflow exceeds the 0.5‐year flood (T0.5). Urban streams had low interannual variability in annual maximum streamflow and brief duration of frequent high flows, as indicated by significant correlations between road density and both CVAMFand T0.5. The broader distribution of streamflow indicated by TQmean may be affected by urban development, but differences in TQmean between streams are also likely a result of other physiographic factors. The increase in the magnitude of frequent high flows due to urban development but not their cumulative duration has important consequences for channel form and bed stability in gravel bed streams because geomorphic equilibrium depends on moderate duration streamflow (e.g., exceeded 10% of the time). Streams with low values of TQmean and T0.5 are narrower than expected from hydraulic geometry. Dimensionless boundary shear stress (t*) for the 0.5‐year flood was inversely related to T0.5 among the streams, indicating frequent and extensive bed disturbance in streams with low values of T0.5. Although stream channels expand and the size of bed material increases in response to urban streamflow patterns, these adjustments may be insufficient to reestablish the disturbance regime in urban streams because of the differential increase in the magnitude of frequent high flows causing disturbance relative to any changes in longer duration, moderate flows that establish a stable channel.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10395779','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10395779"><span>Convective Sedimentation of Colloidal Particles in a Bowl.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stiles; Kagan</p> <p>1999-08-01</p> <p>A physical model, which regards a colloidal dispersion as a single fluid continuum, is used to investigate cellular convection accompanying gravitational sedimentation in a hemispherical bowl with a thin cylindrical shaft along its vertical axis of symmetry. We have adapted the stream-function-vorticity form of the Navier-Stokes equations to describe momentum conservation in axially symmetric containers. These hydrodynamic equations have been coupled to the mass balance equation for binary hydrodynamic diffusion in the presence of a vertical gravitational field. Using finite-element software we have solved the equations governing coupled diffusive and hydrodynamic flow. A rapidly intensifying horizontal toroidal vortex develops around the axis of the bowl. This vortex is characterized by downward barycentric flow along the curved surface of the bowl and upward flow in the vicinity of its axis. We find that after a short period of time this large-scale cellular convection associated with the curved boundary of the bowl greatly enhances the rate of sedimentation. Copyright 1999 Academic Press.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19066526','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19066526"><span>A magnetic tether system to investigate visual and olfactory mediated flight control in Drosophila.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Duistermars, Brian J; Frye, Mark</p> <p>2008-11-21</p> <p>It has been clear for many years that insects use visual cues to stabilize their heading in a wind stream. Many animals track odors carried in the wind. As such, visual stabilization of upwind tracking directly aids in odor tracking. But do olfactory signals directly influence visual tracking behavior independently from wind cues? Also, the recent deluge of research on the neurophysiology and neurobehavioral genetics of olfaction in Drosophila has motivated ever more technically sophisticated and quantitative behavioral assays. Here, we modified a magnetic tether system originally devised for vision experiments by equipping the arena with narrow laminar flow odor plumes. A fly is glued to a small steel pin and suspended in a magnetic field that enables it to yaw freely. Small diameter food odor plumes are directed downward over the fly's head, eliciting stable tracking by a hungry fly. Here we focus on the critical mechanics of tethering, aligning the magnets, devising the odor plume, and confirming stable odor tracking.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21418729','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21418729"><span>Intra- and intergenerational social mobility in relation to height, weight and body mass index in a British national cohort.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Krzyżanowska, Monika; Mascie-Taylor, C G Nicholas</p> <p>2011-09-01</p> <p>Using a sample of 2090 father and son pairs, the extent of intra- and inter-generational social mobility (migration between social classes) was examined over a 42-year period in a British cohort in relation to height, weight and body mass index (BMI). The mean height difference between the highest and lowest social class decreased from about 4 cm in the fathers' generation to about 3 cm in the sons' generation, indicating a decline in heterogeneity in height between classes. For fathers downward intra-generational social mobility ranged between 11% and 18% while between 16% and 26% were upwardly mobile; for sons 15% were downwardly mobile and 21% upwardly mobile. On average downwardly mobile fathers were shorter by between 0.1 cm and 0.7 cm while upwardly mobile fathers were taller by, on average, 0.6 cm to 1.7 cm. For sons, the downwardly mobile were on average 0.7 cm shorter and the upwardly mobile 0.8 cm taller. For weight and BMI there were no consistent relationships with intra-generational mobility in either the fathers' or sons' generations. Inter-generationally, between 18% and 19% of sons were downwardly mobile and between 39% and 40% were upwardly mobile; the downwardly mobile were shorter by about 0.9 cm and the upwardly taller by between 0.6 cm and 1.2 cm. Sons with higher BMI were more likely to be inter-generationally downwardly mobile.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19850024778&hterms=geomagnetism&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dgeomagnetism','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850024778&hterms=geomagnetism&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dgeomagnetism"><span>Thermal, dynamic and compositional aspects of the core-forming Earth</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stevenson, D. J.</p> <p>1985-01-01</p> <p>Core formation is the most important and singular differentiation event in the history of a terrestrial planet. It almost certainly involved the downward migration of a partially or wholly molten iron alloy through a silicate and oxide mantle, and was contemporaneous with accretion. Several important, unresolved issues which have implications for mantle and core geochemistry, the thermal history of the Earth, and the origin of geomagnetism are addressed: whether the early Earth was molten; whether core formation involved low or high pressure geochemistry, or both; early Earth mantle homogenization; whether equilibration established between core forming material and the mantle through which it migrated; and how much iron is stranded and unable to reach the core.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/868248','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/868248"><span>Apparatus for measuring tensile and compressive properties of solid materials at cryogenic temperatures</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Gonczy, John D.; Markley, Finley W.; McCaw, William R.; Niemann, Ralph C.</p> <p>1992-01-01</p> <p>An apparatus for evaluating the tensile and compressive properties of material samples at very low or cryogenic temperatures employs a stationary frame and a dewar mounted below the frame. A pair of coaxial cylindrical tubes extend downward towards the bottom of the dewar. A compressive or tensile load is generated hydraulically and is transmitted by the inner tube to the material sample. The material sample is located near the bottom of the dewar in a liquid refrigerant bath. The apparatus employs a displacement measuring device, such as a linear variable differential transformer, to measure the deformation of the material sample relative to the amount of compressive or tensile force applied to the sample.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AGUFMOS31D..05D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AGUFMOS31D..05D"><span>Integrated Observations From Fixed and AUV Platforms in the Littoral Zone at the SFOMC Coastal Ocean Observatory</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dhanak, M. R.</p> <p>2001-12-01</p> <p>A 12-hour survey of the coastal waters off the east coast of Florida at the South Florida Ocean Measurement Center (SFOMC) coastal ocean observatory, during summer 1999, is described to illustrate the observatory's capabilities for ocean observation. The facility is located close to the Gulf Stream, the continental shelf break being only 3 miles from shore and is therefore influenced by the Gulf Stream meanders and the instability of the horizontal shear layer at its edge. As a result, both cross-shelf and along-shelf components of currents in the littoral zone can undergo dramatic +/- 0.5 m/s oscillations. Observations of surface currents from an OSCR, and of subsurface structure from an autonomous underwater vehicle (AUV) platform, a bottom-mounted ADCP and CT-chain arrays during the survey will be described and compared. The AUV on-board sensors included upward and downward looking 1200kHz ADCP, a CTD package and a small-scale turbulence package, consisting of two shear probes and a fast-response thermistor. Prevailing atmospheric conditions were recorded at an on-site buoy. The combined observations depict flows over a range of scales. Acknowledgements: The observations from the OSCR are due to Nick Shay and Tom Cook (University of Miami), and from the bottom-mounted ADCP, CT chain arrays and the surface buoy are due to Alex Soloviev (Nova Southeastern University) and Mark Luther and Bob Weisberg (University of South Florida).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18422043','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18422043"><span>Impact of downward-mixing ozone on surface ozone accumulation in southern Taiwan.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lin, Ching-Ho</p> <p>2008-04-01</p> <p>The ozone that initially presents in the previous day's afternoon mixing layer can remain in the nighttime atmosphere and then be carried over to the next morning. Finally, this ozone can be brought to the ground by downward mixing as mixing depth increases during the daytime, thereby increasing surface ozone concentrations. Variation of ozone concentration during each of these periods is investigated in this work. First, ozone concentrations existing in the daily early morning atmosphere at the altitude range of the daily maximum mixing depth (residual ozone concentrations) were measured using tethered ozonesondes on 52 experimental days during 2004-2005 in southern Taiwan. Daily downward-mixing ozone concentrations were calculated by a box model coupling the measured daily residual ozone concentrations and daily mixing depth variations. The ozone concentrations upwind in the previous day's afternoon mixing layer were estimated by the combination of back air trajectory analysis and known previous day's surface ozone distributions. Additionally, the relationship between daily downward-mixing ozone concentration and daily photochemically produced ozone concentration was examined. The latter was calculated by removing the former from daily surface maximum ozone concentration. The measured daily residual ozone concentrations distributed at 12-74 parts per billion (ppb) with an average of 42 +/- 17 ppb are well correlated with the previous upwind ozone concentration (R2 = 0.54-0.65). Approximately 60% of the previous upwind ozone was estimated to be carried over to the next morning and became the observed residual ozone. The daily downward-mixing ozone contributes 48 +/- 18% of the daily surface maximum ozone concentration, indicating that the downward-mixing ozone is as important as daily photochemically produced ozone to daily surface maximum ozone accumulation. The daily downward-mixing ozone is poorly correlated with the daily photochemically produced ozone and contributes significantly to the daily variation of surface maximum ozone concentrations (R2 = 0.19). However, the contribution of downward-mixing ozone to daily ozone variation is not included in most existing statistical models developed for predicting daily ozone variation. Finally, daily surface maximum ozone concentration is positively correlated with daily afternoon mixing depth, attributable to the downward-mixing ozone.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013A%26A...557A.115K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013A%26A...557A.115K"><span>Simultaneous EUV and radio observations of bidirectional plasmoids ejection during magnetic reconnection</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kumar, Pankaj; Cho, Kyung-Suk</p> <p>2013-09-01</p> <p>We present a multiwavelength study of the X-class flare, which occurred in active region (AR) NOAA 11339 on 3 November 2011. The extreme ultraviolet (EUV) images recorded by SDO/AIA show the activation of a remote filament (located north of the AR) with footpoint brightenings about 50 min prior to the flare's occurrence. The kinked filament rises up slowly, and after reaching a projected height of ~49 Mm, it bends and falls freely near the AR, where the X-class flare was triggered. Dynamic radio spectrum from the Green Bank Solar Radio Burst Spectrometer (GBSRBS) shows simultaneous detection of both positive and negative drifting pulsating structures (DPSs) in the decimetric radio frequencies (500-1200 MHz) during the impulsive phase of the flare. The global negative DPSs in solar flares are generally interpreted as a signature of electron acceleration related to the upward-moving plasmoids in the solar corona. The EUV images from AIA 94 Å reveal the ejection of multiple plasmoids, which move simultaneously upward and downward in the corona during the magnetic reconnection. The estimated speeds of the upward- and downward-moving plasmoids are ~152-362 and ~83-254 km s-1, respectively. These observations strongly support the recent numerical simulations of the formation and interaction of multiple plasmoids due to tearing of the current-sheet structure. On the basis of our analysis, we suggest that the simultaneous detection of both the negative and positive DPSs is most likely generated by the interaction or coalescence of the multiple plasmoids moving upward and downward along the current-sheet structure during the magnetic reconnection process. Moreover, the differential emission measure (DEM) analysis of the active region reveals a hot flux-rope structure (visible in AIA 131 and 94 Å) prior to the flare initiation and ejection of the multitemperature plasmoids during the flare impulsive phase. Movie is available in electronic form at http://www.aanda.org</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2900191','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2900191"><span>Characterizing the surface charge of synthetic nanomembranes by the streaming potential method</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Datta, Subhra; Conlisk, A. T.; Kanani, Dharmesh M.; Zydney, Andrew L.; Fissell, William H.; Roy, Shuvo</p> <p>2010-01-01</p> <p>The inference of the surface charge of polyethylene glycol (PEG)-coated and uncoated silicon membranes with nanoscale pore sizes from streaming potential measurements in the presence of finite electric double layer (EDL) effects is studied theoretically and experimentally. The developed theoretical model for inferring the pore wall surface charge density from streaming potential measurements is applicable to arbitrary pore cross-sectional shapes and accounts for the effect of finite salt concentration on the ionic mobilities and the thickness of the deposited layer of PEG. Theoretical interpretation of the streaming potential data collected from silicon membranes having nanoscale pore sizes, with/without pore wall surface modification with PEG, indicates that finite electric double layer (EDL) effects in the pore-confined electrolyte significantly affect the interpretation of the membrane charge and that surface modification with PEG leads to a reduction in the pore wall surface charge density. The theoretical model is also used to study the relative significance of the following uniquely nanoscale factors affecting the interpretation of streaming potential in moderate to strongly charged pores: altered net charge convection by applied pressure differentials, surface-charge effects on ionic conduction, and electroosmotic convection of charges. PMID:20462592</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DFD.R8001H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DFD.R8001H"><span>Forces on particles in microstreaming flows</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hilgenfeldt, Sascha; Rallabandi, Bhargav; Thameem, Raqeeb</p> <p>2015-11-01</p> <p>In various microfluidic applications, vortical steady streaming from ultrasonically driven microbubbles is used in concert with a pressure-driven channel flow to manipulate objects. While a quantitative theory of this boundary-induced streaming is available, little work has been devoted to a fundamental understanding of the forces exerted on microparticles in boundary streaming flows, even though the differential action of such forces is central to applications like size-sensitive sorting. Contrary to other microfluidic sorting devices, the forces in bubble microstreaming act over millisecond times and micron length scales, without the need for accumulated deflections over long distances. Accordingly, we develop a theory of hydrodynamic forces on the fast time scale of bubble oscillation using the lubrication approximation, showing for the first time how particle displacements are rectified near moving boundaries over multiple oscillations in parallel with the generation of the steady streaming flow. The dependence of particle migration on particle size and the flow parameters is compared with experimental data. The theory is applicable to boundary streaming phenomena in general and demonstrates how particles can be sorted very quickly and without compromising device throughput. We acknowledge support by the National Science Foundation under grant number CBET-1236141.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930090934','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930090934"><span>Linearized compressible-flow theory for sonic flight speeds</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Heaslet, Max A; Lomax, Harvard; Spreiter, John R</p> <p>1950-01-01</p> <p>The partial differential equation for the perturbation velocity potential is examined for free-stream Mach numbers close to and equal to one. It is found that, under the assumptions of linearized theory, solutions can be found consistent with the theory for lifting-surface problems both in stationary three-dimensional flow and in unsteady two-dimensional flow. Several examples are solved including a three dimensional swept-back wing and two dimensional harmonically-oscillating wing, both for a free stream Mach number equal to one. Momentum relations for the evaluation of wave and vortex drag are also discussed. (author)</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/863441','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/863441"><span>Drill drive mechanism</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Dressel, Michael O.</p> <p>1979-01-01</p> <p>A drill drive mechanism is especially adapted to provide both rotational drive and axial feed for a drill of substantial diameter such as may be used for drilling holes for roof bolts in mine shafts. The drill shaft is made with a helical pattern of scroll-like projections on its surface for removal of cuttings. The drill drive mechanism includes a plurality of sprockets carrying two chains of drive links which are arranged to interlock around the drill shaft with each drive link having depressions which mate with the scroll-like projections. As the chain links move upwardly or downwardly the surfaces of the depressions in the links mate with the scroll projections to move the shaft axially. Tangs on the drive links mate with notch surfaces between scroll projections to provide a means for rotating the shaft. Projections on the drive links mate together at the center to hold the drive links tightly around the drill shaft. The entire chain drive mechanism is rotated around the drill shaft axis by means of a hydraulic motor and gear drive to cause rotation of the drill shaft. This gear drive also connects with a differential gearset which is interconnected with a second gear. A second motor is connected to the spider shaft of the differential gearset to produce differential movement (speeds) at the output gears of the differential gearset. This differential in speed is utilized to drive said second gear at a speed different from the speed of said gear drive, this speed differential being utilized to drive said sprockets for axial movement of said drill shaft.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22285111','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22285111"><span>Can upbeat nystagmus increase in downward, but not upward, gaze?</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kim, Hyun-Ah; Yi, Hyon-Ah; Lee, Hyung</p> <p>2012-04-01</p> <p>Upbeat nystagmus (UBN) is typically increased with upward gaze and decreased with downward gaze. We describe a patient with acute multiple sclerosis who developed primary position UBN with a linear slow phase waveform, in which the velocity of nystagmus was intensified in downward gaze and decreased during upward gaze. Brain MRI showed high signal lesions in the paramedian dorsal area of the caudal medulla encompassing the most caudal part of the perihypoglossal nuclei. Clinicians should be aware of possibility of a caudal medullary lesion in a patient with UBN, especially when the velocity of the UBN is increased in downward gaze. Copyright © 2011 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.H51D1303K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.H51D1303K"><span>Effects of Large Wood on River-Floodplain Connectivity in a Headwater Appalachian Stream</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Keys, T.; Govenor, H.; Jones, C. N.; Hession, W. C.; Scott, D.; Hester, E. T.</p> <p>2017-12-01</p> <p>Large wood (LW) plays an important, yet often undervalued role in stream ecosystems. Traditionally, LW has been removed from streams for aesthetic, navigational, and flood mitigation purposes. However, extensive research over the last three decades has directly linked LW to critical ecosystem functions including habitat provisioning, stream geomorphic stability, and water quality improvements; and as such, LW has increasingly been implemented in stream restoration activities. One of the proposed benefits to this restoration approach is that LW increases river-floodplain connectivity, potentially decreasing downstream flood peaks and improving water quality. Here, we conducted two experiential floods (i.e., one with and one without LW) in a headwater, agricultural stream to explore the effect of LW on river-floodplain connectivity and resulting hydrodynamic processes. During each flood, we released an equal amount of water to the stream channel, measured stream discharge at upstream and downstream boundaries, and measured inundation depth at multiple locations across the floodplain. We then utilized a 2-dimensional hydrodynamic model (HEC-RAS) to simulate floodplain hydrodynamics. We first calibrated the model using observations from the two experimental floods. Then, we utilized the calibrated model to evaluate differing LW placement strategies and effects under various flow conditions. Results show that the addition of LW to the channel decreased channel velocity and increased inundation extent, inundation depth, and floodplain velocity. Differential placement of LW along the stream impacted the levels of floodplain discharge, primarily due to the geomorphic characteristics of the stream. Finally, we examined the effects of LW on floodplain hydrodynamics across a synthetic flow record, and found that the magnitude of river-floodplain connectivity decreased as recurrence interval increased, with limited impacts on storm events with a recurrence interval of 25 years or greater. These findings suggest that LW plays a substantial role in river-floodplain connectivity of headwater streams and associated ecosystem services.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.B52A..06R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.B52A..06R"><span>Quantifying Nitrogen Transport from Riparian Groundwater Seeps to a Headwater Stream in an Agricultural Watershed</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Redder, B.; Buda, A. R.; Kennedy, C. D.; Folmar, G.; DeWalle, D. R.; Boyer, E. W.</p> <p>2017-12-01</p> <p>Headwater streams in the Northeast region of the United States typically receive more than 50% of their base flow from groundwater, either by diffuse discharge through the streambed or by localized discharge through riparian seeps. It is very difficult to separate the individual contributions of these two groundwater fluxes to streamflow. Furthermore, riparian seeps show significant variability in discharge and nutrient concentration, adding uncertainty to estimates of groundwater-based nitrogen inputs to streams. In this study, we combined stream measurements at two different scales to quantify groundwater discharge by matrix flow through the streambed and by macropore flow through the riparian zone. The study site was a 175-m stream reach located in a heavily cultivated 45-hectare watershed in east-central Pennsylvania. Differential streamflow gauging and streambed measurements of hydraulic head gradient, hydraulic conductivity, and groundwater chemistry were used to solve for the riparian groundwater flux in a reach mass balance equation. Adopting a mass balance approach, riparian groundwater fluxes ranged from 115-205 m3 d-1, transporting 2-4 kg N d-1 of nitrate from the fractured bedrock aquifer to the stream. Air-water manometer readings from short-screened piezometers installed in the shallow streambed (30 cm) indicated slightly losing head gradients between the stream and groundwater, despite substantial (36-66%) increases in stream flow along the stream reach. Preliminary chemical data for the stream, streambed, and shallow ground water suggest that the stream is partially disconnected from the underlying aquifer and that riparian groundwater seeps supply essentially all water and nitrogen to the system. These results, along with the comparison of shallow and deep aquifer water with seep chemistry, provide insight into sources of water to riparian groundwater seeps and allow us to determine the transport and fate of nitrogen in a fractured aquifer system. The use of water isotopes and hydrometric data will be used to further test the hypothesis that this is a perched system disconnected from the aquifer below.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70179135','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70179135"><span>Differential survival among sSOD-1* genotypes in Chinook Salmon</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hayes, Michael C.; Reisenbichler, Reginald R.; Rubin, Stephen P.; Wetzel, Lisa A.; Marshall , Anne R.</p> <p>2011-01-01</p> <p>Differential survival and growth were tested in Chinook salmon Oncorhynchus tshawytscha expressing two common alleles, *–100 and *–260, at the superoxide dismutase locus (sSOD-1*). These tests were necessary to support separate studies in which the two alleles were used as genetic marks under the assumption of mark neutrality. Heterozygous adults were used to produce progeny with –100/–100, –100/–260, and –260/–260 genotypes that were reared in two natural streams and two hatcheries in the states of Washington and Oregon. The latter also were evaluated as returning adults. In general, the genotype ratios of juveniles reared at hatcheries were consistent with high survival and little or no differential survival in the hatchery. Adult returns at one hatchery were significantly different from the expected proportions, and the survival of the –260/–260 genotype was 0.56–0.89 times that of the –100/–100 genotype over four year-classes. Adult returns at a second hatchery (one year-class) were similar but not statistically significant: survival of the –260/–260genotype relative to the –100/–100 genotype was 0.76. The performance of the heterozygote group was intermediate at both hatcheries. Significant differences in growth were rarely observed among hatchery fish (one year-class of juveniles and one age-class of adult males) but were consistent with greater performance for the –100/–100 genotype. Results from two groups of juveniles reared in streams (one year-class from each stream) suggested few differences in growth, but the observed genotype ratios were significantly different from the expected ratios in one stream. Those differences were consistent with the adult data; survival for the –260/–260 genotype was 76% of that of the –100/–100 genotype. These results, which indicate nonneutrality among sSOD-1* genotypes, caused us to modify our related studies and suggest caution in the interpretation of results and analyses in which allozyme marks are assumed to be neutral.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014MNRAS.445.3788G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014MNRAS.445.3788G"><span>`Skinny Milky Way please', says Sagittarius</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gibbons, S. L. J.; Belokurov, V.; Evans, N. W.</p> <p>2014-12-01</p> <p>Motivated by recent observations of the Sagittarius stream, we devise a rapid algorithm to generate faithful representations of the centroids of stellar tidal streams formed in a disruption of a progenitor of an arbitrary mass in an arbitrary potential. Our method works by releasing swarms of test particles at the Lagrange points around the satellite and subsequently evolving them in a combined potential of the host and the progenitor. We stress that the action of the progenitor's gravity is crucial to making streams that look almost indistinguishable from the N-body realizations, as indeed ours do. The method is tested on mock stream data in three different Milky Way potentials with increasing complexity, and is shown to deliver unbiased inference on the Galactic mass distribution out to large radii. When applied to the observations of the Sagittarius stream, our model gives a natural explanation of the stream's apocentric distances and the differential orbital precession. We, therefore, provide a new independent measurement of the Galactic mass distribution beyond 50 kpc. The Sagittarius stream model favours a light Milky Way with the mass 4.1 ± 0.4 × 1011 M⊙ at 100 kpc, which can be extrapolated to 5.6 ± 1.2 × 1011 M⊙ at 200 kpc. Such a low mass for the Milky Way Galaxy is in good agreement with estimates from the kinematics of halo stars and from the satellite galaxies (once Leo I is removed from the sample). It entirely removes the `Too Big To Fail Problem'.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26766394','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26766394"><span>Permafrost thaw and intense thermokarst activity decreases abundance of stream benthic macroinvertebrates.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chin, Krista S; Lento, Jennifer; Culp, Joseph M; Lacelle, Denis; Kokelj, Steven V</p> <p>2016-08-01</p> <p>Intensification of permafrost thaw has increased the frequency and magnitude of large permafrost slope disturbances (mega slumps) in glaciated terrain of northwestern Canada. Individual thermokarst disturbances up to 40 ha in area have made large volumes of previously frozen sediments available for leaching and transport to adjacent streams, significantly increasing sediment and solute loads in these systems. To test the effects of this climate-sensitive disturbance regime on the ecology of Arctic streams, we explored the relationship between physical and chemical variables and benthic macroinvertebrate communities in disturbed and undisturbed stream reaches in the Peel Plateau, Northwest Territories, Canada. Highly disturbed and undisturbed stream reaches differed with respect to taxonomic composition and invertebrate abundance. Minimally disturbed reaches were not differentiated by these variables but rather were distributed along a disturbance gradient between highly disturbed and undisturbed sites. In particular, there was evidence of a strong negative relationship between macroinvertebrate abundance and total suspended solids, and a positive relationship between abundance and the distance from the disturbance. Increases in both sediments and nutrients appear to be the proximate cause of community differences in highly disturbed streams. Declines in macroinvertebrate abundance in response to slump activity have implications for the food webs of these systems, potentially leading to negative impacts on higher trophic levels, such as fish. Furthermore, the disturbance impacts on stream health can be expected to intensify as climate change increases the frequency and magnitude of thermokarst. © 2016 John Wiley & Sons Ltd.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24470258','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24470258"><span>Can representational trajectory reveal the nature of an internal model of gravity?</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>De Sá Teixeira, Nuno; Hecht, Heiko</p> <p>2014-05-01</p> <p>The memory for the vanishing location of a horizontally moving target is usually displaced forward in the direction of motion (representational momentum) and downward in the direction of gravity (representational gravity). Moreover, this downward displacement has been shown to increase with time (representational trajectory). However, the degree to which different kinematic events change the temporal profile of these displacements remains to be determined. The present article attempts to fill this gap. In the first experiment, we replicate the finding that representational momentum for downward-moving targets is bigger than for upward motions, showing, moreover, that it increases rapidly during the first 300 ms, stabilizing afterward. This temporal profile, but not the increased error for descending targets, is shown to be disrupted when eye movements are not allowed. In the second experiment, we show that the downward drift with time emerges even for static targets. Finally, in the third experiment, we report an increased error for upward-moving targets, as compared with downward movements, when the display is compatible with a downward ego-motion by including vection cues. Thus, the errors in the direction of gravity are compatible with the perceived event and do not merely reflect a retinotopic bias. Overall, these results provide further evidence for an internal model of gravity in the visual representational system.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21568542','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21568542"><span>Systematic measurements of ion-proton differential streaming in the solar wind.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Berger, L; Wimmer-Schweingruber, R F; Gloeckler, G</p> <p>2011-04-15</p> <p>The small amount of heavy ions in the highly rarefied solar wind are sensitive tracers for plasma-physics processes, which are usually not accessible in the laboratory. We have analyzed differential streaming between heavy ions and protons in the solar wind at 1 AU. 3D velocity vector and magnetic field measurements from the Solar Wind Electron Proton Alpha Monitor and the Magnetometer aboard the Advanced Composition Explorer were used to reconstruct the ion-proton difference vector v(ip) = v(i) - v(p) from the 12 min 1D Solar Wind Ion Composition Spectrometer observations. We find that all 44 analyzed heavy ions flow along the interplanetary magnetic field at velocities which are smaller than, but comparable to, the local Alfvén speed C(A). The flow speeds of 35 of the 44 ion species lie within the range of ±0.15C(A) around 0.55C(A), the flow speed of He(2+).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70019379','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70019379"><span>Reactive solute transport in streams: 1. Development of an equilibrium- based model</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Runkel, Robert L.; Bencala, Kenneth E.; Broshears, Robert E.; Chapra, Steven C.</p> <p>1996-01-01</p> <p>An equilibrium-based solute transport model is developed for the simulation of trace metal fate and transport in streams. The model is formed by coupling a solute transport model with a chemical equilibrium submodel based on MINTEQ. The solute transport model considers the physical processes of advection, dispersion, lateral inflow, and transient storage, while the equilibrium submodel considers the speciation and complexation of aqueous species, precipitation/dissolution and sorption. Within the model, reactions in the water column may result in the formation of solid phases (precipitates and sorbed species) that are subject to downstream transport and settling processes. Solid phases on the streambed may also interact with the water column through dissolution and sorption/desorption reactions. Consideration of both mobile (water-borne) and immobile (streambed) solid phases requires a unique set of governing differential equations and solution techniques that are developed herein. The partial differential equations describing physical transport and the algebraic equations describing chemical equilibria are coupled using the sequential iteration approach.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2010/5079/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2010/5079/"><span>Evaluating effects of potential changes in streamflow regime on fish and aquatic-invertebrate assemblages in the New Jersey Pinelands</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Kennen, Jonathan G.; Riskin, Melissa L.</p> <p>2010-01-01</p> <p>Changes in water demand associated with population growth and changes in land-use practices in the Pinelands region of southern New Jersey will have a direct effect on stream hydrology. The most pronounced and measurable hydrologic effect is likely to be flow reductions associated with increasing water extraction. Because water-supply needs will continue to grow along with population in the Pinelands area, the goal of maintaining a sustainable balance between the availability of water to protect existing aquatic assemblages while conserving the surficial aquifer for long-term support of human water use needs to be addressed. Although many aquatic fauna have shown resilience and resistance to short-term changes in flows associated with water withdrawals, sustained effects associated with ongoing water-development processes are not well understood. In this study, the U.S. Geological Survey sampled forty-three 100-meter-long stream reaches during high- and low-flow periods across a designed hydrologic gradient ranging from small- (4.1 square kilometers (1.6 square miles)) to medium- (66.3 square kilometers (25.6 square miles)) sized Pinelands stream basins. This design, which uses basin size as a surrogate for water availability, provided an opportunity to evaluate the possible effects of potential variation in stream hydrology on fish and aquatic-invertebrate assemblage response in New Jersey Pinelands streams where future water extraction is expected based on known build-out scenarios. Multiple-regression models derived from extracted non-metric multidimensional scaling axis scores of fish and aquatic invertebrates indicate that some variability in aquatic-assemblage composition across the hydrologic gradient is associated with anthropogenic disturbance, such as urbanization, changes in stream chemistry, and concomitant changes in high-flow runoff patterns. To account for such underlying effects in the study models, any flow parameter or assemblage attribute that was found to be significantly correlated (|rho| = 0.5000) to known anthropogenic drivers (for example, the amount of urbanization in the basin) was eliminated from analysis. A reduced set of low- and annual-flow hydrologic variables, found to be unrelated to anthropogenic influences, was used to develop assemblage-response models. Many linear (monotonic) and curvilinear bivariate flow-ecology response models were developed for fish and invertebrate assemblages. For example, the duration and magnitude of low-flow events were significant predictors of invertebrate-assemblage complexity (for example, invertebrate-species richness, Plecoptera richness, and Ephemeroptera abundance); however, response models between flow attributes and fish-assemblage structure were, in all cases, more poorly fit. Annual flow variability also was important, especially variability across mean minimum monthly flows and annual mean streamflow. In general, all response models followed upward or downward trends that would be expected given hydrologic changes in Pinelands streams. This study demonstrates that the structural and functional response of aquatic assemblages of the Pinelands ecosystem resulting from changes in water-use practices associated with population growth and increased water extraction may be predictable.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25656715','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25656715"><span>Downward economic mobility and preterm birth: an exploratory study of Chicago-born upper class White mothers.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Collins, James W; Rankin, Kristin M; David, Richard J</p> <p>2015-07-01</p> <p>A paucity of published data exists on the factors underlying the relatively poor birth outcome of non-Hispanic White women in the United States. To determine whether downward economic mobility is a risk factor for preterm birth (<37 weeks, PTB) among upper class-born White women. Stratified and multilevel logistic regression analyses were performed on an Illinois transgenerational dataset of non-Hispanic White infants (1989-1991) and their women (1956-1976) with appended US census income information. The study sample was restricted to singleton births of Chicago-born upper-class (defined by early-life residence in affluent neighborhoods) non-Hispanic White women. Upper class-born White women (n = 4,891) who did not experience downward economic mobility by the time of delivery had a PTB rate of 5.4 %. Those women who experienced slight (n = 5,112), moderate (n = 2,158), or extreme (n = 339) downward economic mobility had PTB rates of 6.5, 8.5, and 10.1 %, respectively; RR (95 % CI) = 1.2 (1.0-4.0), 1.6 (1.3-1.9), and 1.9 (1.3-2.6), respectively. Maternal downward economic mobility was also associated with an increased prevalence of biologic, medical, and behavioral risk factors. Interestingly, the relationship between moderate to extreme downward mobility and preterm birth was stronger among former low birth weight (<2500 g, LBW) than non-LBW women: 2.8 (1.4-5.8) versus 1.6 (1.3-1.9), respectively. In multilevel logistic regression models, the adjusted odds ratio of preterm birth for former LBW and non-LBW women who experienced any downward mobility (compared to those women with lifelong upper class status) equaled 2.4 (1.1-5.3) and 1.1 (1.0-1.1), respectively. Downward economic mobility is associated with an increased risk of preterm birth among upper class-born White urban women; this phenomenon is strongest among former low birth weight women.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70022133','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70022133"><span>Mobilization and attenuation of metals downstream from a base-metal mining site in the Matra Mountains, northeastern Hungary</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Odor, L.; Wanty, R.B.; Horvath, I.; Fugedi, U.; ,</p> <p>1999-01-01</p> <p>Regional geochemical baseline values have been established for Hungary by the use of low-density stream-sediment surveys of flood-plain deposits of large drainage basins and of the fine fraction of stream sediments. The baseline values and anomaly thresholds thus produced helped to evaluate the importance of high toxic element concentrations found in soils in a valley downstream of a polymetallic vein-type base-metal mine. Erosion of the mine dumps and flotation dump, losses of metals during filtering, storage and transportation, human neglects, and operational breakdowns, have all contributed to the contamination of a small catchment basin in a procession of releases of solid waste. The sulfide-rich waste material weathers to a yellow color; this layer of 'yellow sand' blankets a narrow strip of the floodplain of Toka Creek in the valley near the town of Gyongyosoroszi. Contamination was spread out in the valley by floods. Metals present in the yellow sand include Pb, As, Cd, Cu, Zn, and Sb. Exposure of the local population to these metals may occur through inhalation of airborne particulates or by ingestion of these metals that are taken up by crops grown in the valley. To evaluate the areal extent and depth of the contamination, active stream sediment, flood-plain deposits, lake or reservoir sediments, soils, and surface water were sampled along the erosion pathways downstream of the mine and dumps. The flood-plain profile was sampled in detail to see the vertical distribution of elements and to relate the metal concentrations to the sedimentation and contamination histories of the flood plain. Downward migration of mobile Zn and Cd from the contaminated upper layers under supergene conditions is observed, while vertical migration of Pb, As, Hg and Sb appears to be insignificant. Soil profiles of 137Cs which originated from above-ground atomic bomb tests and the Chernobyl accident, provide good evidence that the upper 30-40 cm of the flood-plain sections, which includes the yellow sand contamination, were deposited in the last 30-40 years.The regional geochemical baseline values are established for Hungary using low-density stream-sediment surveys of flood-plain deposits of large drainage basins and of the fine fraction of stream sediments. The baseline values and anomaly thresholds allowed the evaluation of the importance of high toxic element concentrations in soils in a valley, downstream of a polymetallic vein-type base-metal mine. The metals present in the yellow sand include Pb, As, Cd, Cu, Zn and Sb. To evaluate the areal extent and depth of the contamination, active stream sediment, flood-plain deposits, lake or reservoir sediments, the soils and surface water were sampled along the erosion pathways downstream of the mine and dumps.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2008/5134/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2008/5134/"><span>Summary and Evaluation of the Quality of Stormwater in Denver, Colorado, October 2001 to October 2005</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Bossong, Clifford R.; Fleming, Andrea C.</p> <p>2008-01-01</p> <p>Stormwater in the Denver area was sampled by the U.S. Geological Survey, in cooperation with the Urban Drainage and Flood Control District, in a network of five monitoring stations - three on the South Platte River and two on tributary streams, beginning in October 2001 and continuing through October 11, 2005. Composite samples of stormwater were analyzed at the U.S. Geological Survey National Water Quality Laboratory during water years 2003-2005 and the Metro Wastewater Reclamation District Laboratory during water year 2002 for water-quality properties such as pH, specific conductance, hardness, and residue on evaporation at 105 degrees Celsius; and for constituents such as major ions (calcium, chloride, fluoride, magnesium, potassium, sodium, and sulfate) in 2005, organic carbon and nutrients, including ammonia, nitrite plus nitrate, ammonia plus organic nitrogen, phosphorus, and orthophosphate; and for metals, including total and dissolved phases of copper, lead, manganese, and zinc. Samples analyzed for bacteriological indicators such as Escherichia coli and fecal coliform collected during selected storms also were analyzed at the Metro Wastewater Reclamation Laboratory. Discrete samples collected during selected storms were analyzed at the U.S. Geological Survey National Water Quality Laboratory for a suite of water-quality properties and constituents similar to those analyzed in the composite samples but that did not include determinations for total phases of metals. Streamflow characteristics associated with 176 composite stormwater samples indicate that most samples were collected from hydrographs classified as falling or event hydrographs and that only a few samples were collected from rising hydrographs. Results from laboratory analyses of the composite samples indicate spatial patterns in which concentrations for some constituents increase with contributing drainage area in the South Platte River and Sand Creek, but no well-defined relation with the amount of urban land cover was identified using data available from the U.S. Geological Survey National Land Cover data. Results from 22 discrete samples collected during two storms and used to obtain composited results with various weighting methods indicate that correlation coefficients between time-weighted and volume-weighted concentrations were generally at least 0.65, indicating a strong direct correlation between the two weighting methods for the stations involved in this study. In addition, the central tendency for relative percent differences between the time- and volume-weighting methods typically has an absolute value of about 10 or less, indicating good agreement for these weighting methods for data collected as part of this study. Comparison of stormwater results to numeric standards for streams developed by the Colorado Department of Public Health and Environment on the basis of use classifications indicates that, for water-quality properties and constituents other than bacteriological indicators, there were very few exceptions to numeric standards. Bacteriological indicators, however, such as Escherichia coli and fecal coliform consistently exceeded numeric standards in all bacteriological samples. An evaluation of laboratory results from composite samples on the basis of annual means indicates the presence of some simple upward and downward temporal trends in concentrations. In general, for annual means of results for all stations, hardness, ammonia plus organic nitrogen, total phosphorus, most dissolved metals (lead, manganese, and zinc), and all total metals (copper, lead, manganese, and zinc) all indicate annual means that decrease each year, or downward trends. Some trends were indicated only at individual stations in the network rather than at all stations. Ammonia as nitrogen at Union, Denver, and Henderson, orthophosphate at Sand Creek, and nitrite plus nitrate at Denver and Henderson all indicate decreasing annual means, or downward tr</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26061987','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26061987"><span>The efficacy of maxillary protraction protocols with the micro-implant-assisted rapid palatal expander (MARPE) and the novel N2 mini-implant-a finite element study.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Moon, Won; Wu, Kimberley W; MacGinnis, Matthew; Sung, Jay; Chu, Howard; Youssef, George; Machado, Andre</p> <p>2015-01-01</p> <p>Maxillary protraction with the novel N2 mini-implant- and micro-implant-assisted rapid palatal expander (MARPE) can potentially provide significant skeletal effects without surgery, even in older patients where conventional facemask therapy has limited skeletal effects. However, the skeletal effects of altering the location and direction of force from mini-implant-assisted maxillary protraction have not been extensively analyzed. In this study, the application of the novel N2 mini-implant as an orthopedic anchorage device is explored in its ability to treat patients with class III malocclusions. A 3D cranial mesh model with associated sutures was developed from CT images and Mimics modeling software. Utilizing ANSYS simulation software, protraction forces were applied at different locations and directions to simulate conventional facemask therapy and seven maxillary protraction protocols utilizing the novel N2 mini-implant. Stress distribution and displacement were analyzed. Video animations and superimpositions were created. By changing the vector of force and location of N2 mini-implant, the maxilla was displaced differentially. Varying degrees of forward, downward, and rotational movements were observed in each case. For brachyfacial patients, anterior micro-implant-supported protraction at -45° or intermaxillary class III elastics at -45° are recommended. For dolicofacial patients, either anterior micro-implants at -15° or an intermaxillary spring at +30° is recommended. For mesofacial patients with favorable vertical maxillary position, palatal micro-implants at -30° are recommended; anterior micro-implants at -30° are preferred for shallow bites. For patients with a severe mid-facial deficiency, intermaxillary class III elastics at -30° are most effective in promoting anterior growth of the maxilla. By varying the location of N2 mini-implants and vector of class III mechanics, clinicians can differentially alter the magnitude of forward, downward, and rotational movement of the maxilla. As a result, treatment protocol can be customized for each unique class III patient.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27883136','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27883136"><span>Continuous micro-vortex-based nanoparticle manipulation via focused surface acoustic waves.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Collins, David J; Ma, Zhichao; Han, Jongyoon; Ai, Ye</p> <p>2016-12-20</p> <p>Despite increasing demand in the manipulation of nanoscale objects for next generation biological and industrial processes, there is a lack of methods for reliable separation, concentration and purification of nanoscale objects. Acoustic methods have proven their utility in contactless manipulation of microscale objects mainly relying on the acoustic radiation effect, though the influence of acoustic streaming has typically prevented manipulation at smaller length scales. In this work, however, we explicitly take advantage of the strong acoustic streaming in the vicinity of a highly focused, high frequency surface acoustic wave (SAW) beam emanating from a series of focused 6 μm substrate wavelength interdigital transducers patterned on a piezoelectric lithium niobate substrate and actuated with a 633 MHz sinusoidal signal. This streaming field serves to focus fluid streamlines such that incoming particles interact with the acoustic field similarly regardless of their initial starting positions, and results in particle displacements that would not be possible with a travelling acoustic wave force alone. This streaming-induced manipulation of nanoscale particles is maximized with the formation of micro-vortices that extend the width of the microfluidic channel even with the imposition of a lateral flow, occurring when the streaming-induced flow velocities are an order of magnitude larger than the lateral one. We make use of this acoustic streaming to demonstrate the continuous and differential focusing of 100 nm, 300 nm and 500 nm particles.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20125803','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20125803"><span>Instrumentation for remote sensing solar radiation from light aircraft.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Howard, J A; Barton, I J</p> <p>1973-10-01</p> <p>The paper outlines the instrumentation needed to study, from a light aircraft, the solar radiation reflected by ground surfaces and the incoming solar radiation. A global shortwave radiometer was mounted on the roof of the aircraft and a specially designed mount was used to support a downward pointing 70-mm aerial camera, a downward pointing narrow-beam pyranometer, and, sometimes, a downward pointing global shortwave pyranometer. Calibration factors were determined for the three pyranometers by comparison with a standard Angstrom compensation pyrheliometer. Results have indicated trends in the albedos of major plant communities and have shown that the calculated albedo values vary according to whether the downward pointing instrument is narrow-beam or global. Comparisons were also made with albedos measured on the ground.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AIPC.1714c0004M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AIPC.1714c0004M"><span>Evolution of relative drifts and temperature anisotropies in expanding collisionless plasmas—1.5D vs. 2.5D hybrid simulations</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maneva, Y. G.; Poedts, S.; Araneda, J. A.</p> <p>2016-02-01</p> <p>We compare the results from 1.5D and 2.5D hybrid simulations (with fluid electrons, and kinetic/particle-in-cell protons and α particles) to investigate the effect of the solar wind expansion on the evolution of ion relative drifts in collisionless fast wind streams. We initialize the system with initial relative drifts and follow its evolution in time within and without the expanding box model, which takes into account the gradual solar wind expansion in the interplanetary medium. The decay of the differential streaming follows similar pattern in the 1.5D and 2.5D non-expanding cases. For the 1.5D studies we find no difference in the evolution of the initial relative drift speed with and without expansion, whereas in the two-dimensional case the differential streaming is further suppressed once the solar wind expansion is taken into account. This implies that a stronger acceleration source is required to compensate for the effect of the expansion and produce the observed solar wind acceleration rate. The 1.5D case shows stronger oscillations in all plasma properties with higher temperature anisotropies for the minor ions in the first few hundred gyro-periods of the simulations. Yet the preferential perpendicular heating for the minor ions is stronger in the 2.5D case with higher temperature anisotropies at the final stage.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=307378&keyword=mercury+NOT+planet&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50','EPA-EIMS'); return false;" href="https://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=307378&keyword=mercury+NOT+planet&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50"><span>Simulating Mercury And Methyl Mercury Stream Concentrations At Multiple Scales in a Wetland Influenced Coastal Plain Watershed (McTier Creek, SC, USA)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Use of Mechanistic Models to?Improve Understanding: Differential, mass balance, process-based Spatial and temporal resolution Necessary simplifications of system complexity Combing field monitoring and modeling efforts Balance between capturing complexity and maintaining...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950009409','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950009409"><span>Mass analysis addition to the Differential Ion Flux Probe (DIFP) study</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wright, K. H., Jr.; Jolley, Richard</p> <p>1994-01-01</p> <p>The objective of this study is to develop a technique to measure the characteristics of space plasmas under highly disturbed conditions; e.g., non-Maxwellian plasmas with strong drifting populations and plasmas contaminated by spacecraft outgassing. The approach, conducted in conjunction with current MSFC activities, is to extend the capabilities of the Differential Ion Flux Probe (DIFP) to include a high throughput mass measurement that does not require either high voltage or contamination sensitive devices such as channeltron electron multipliers or microchannel plates. This will significantly reduce the complexity and expense of instrument fabrication, testing, and integration of flight hardware compared to classical mass analyzers. The feasibility of the enhanced DIFP has been verified by using breadboard test models in a controlled plasma environment. The ability to manipulate particles through the instrument regardless of incident angle, energy, or ionic component has been amply demonstrated. The energy analysis mode is differential and leads directly to a time-of-flight mass measurement. With the new design, the DIFP will separate multiple ion streams and analyze each stream independently for ion flux intensity, velocity (including direction of motion), mass, and temperature (or energy distribution). In particular, such an instrument will be invaluable on follow-on electrodynamic TSS missions and, possibly, for environmental monitoring on the space station.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/871902','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/871902"><span>Pyrolysis and hydrolysis of mixed polymer waste comprising polyethyleneterephthalate and polyethylene to sequentially recover</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Evans, Robert J.; Chum, Helena L.</p> <p>1998-01-01</p> <p>A process of using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents; selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feedstream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19494459','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19494459"><span>A new methodology for determining dispersion coefficient using ordinary and partial differential transport equations.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cho, Kyung Hwa; Lee, Seungwon; Ham, Young Sik; Hwang, Jin Hwan; Cha, Sung Min; Park, Yongeun; Kim, Joon Ha</p> <p>2009-01-01</p> <p>The present study proposes a methodology for determining the effective dispersion coefficient based on the field measurements performed in Gwangju (GJ) Creek in South Korea which is environmentally degraded by the artificial interferences such as weirs and culverts. Many previous works determining the dispersion coefficient were limited in application due to the complexity and artificial interferences in natural stream. Therefore, the sequential combination of N-Tank-In-Series (NTIS) model and Advection-Dispersion-Reaction (ADR) model was proposed for evaluating dispersion process in complex stream channel in this study. The series of water quality data were intensively monitored in the field to determine the effective dispersion coefficient of E. coli in rainy day. As a result, the suggested methodology reasonably estimates the dispersion coefficient for GJ Creek with 1.25 m(2)/s. Also, the sequential combined method provided Number of tank-Velocity-Dispersion coefficient (NVD) curves for convenient evaluation of dispersion coefficient of other rivers or streams. Comparing the previous studies, the present methodology is quite general and simple for determining the effective dispersion coefficients which are applicable for other rivers and streams.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150022421','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150022421"><span>Buoyant Effects on the Flammability of Silicone Samples Planned for the Spacecraft Fire Experiment (Saffire)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Niehaus, Justin E.; Ferkul, Paul V.; Gokoglu, Suleyman A.; Ruff, Gary A.</p> <p>2015-01-01</p> <p>Flammability experiments on silicone samples were conducted in anticipation of the Spacecraft Fire Experiment (Saffire). The sample geometry was chosen to match the NASA 6001 Test 1 specification, namely 5 cm wide by 30 cm tall. Four thicknesses of silicone (0.25, 0.36, 0.61 and 1.00 mm) were examined. Tests included traditional upward buoyant flame spread using Test 1 procedures, downward opposed-flow flame spread, horizontal and angled flame spread, and forced-flow upward and downward flame spread. In addition to these configurations, upward and downward tests were conducted in a chamber with varying oxygen concentrations. In the upward buoyant flame spread tests, the flame generally did not burn the entire sample. As thickness was increased, the flame spread distance decreased before flame extinguishment. For the thickest sample, ignition could not be achieved. In the downward tests, the two thinnest samples permitted the flame to burn the entire sample, but the spread rate was lower compared to the corresponding upward values. The other two thicknesses could not be ignited in the downward configuration. The increased flammability for downward spreading flames relative to upward ones is uncommon. The two thinnest samples also burned completely in the horizontal configuration, as well as at angles up to 75 degrees from the horizontal. Upward tests in air with an added forced flow were more flammable. The upward and downward flammability behavior was compared in atmospheres of varying oxygen concentration to determine a maximum oxygen concentration for each configuration. Complementary analyses using EDS, TGA, and SEM techniques suggest the importance of the silica layer deposited downstream onto the unburned sample surface.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5591849','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5591849"><span>Self-reflection Orients Visual Attention Downward</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Liu, Yi; Tong, Yu; Li, Hong</p> <p>2017-01-01</p> <p>Previous research has demonstrated abstract concepts associated with spatial location (e.g., God in the Heavens) could direct visual attention upward or downward, because thinking about the abstract concepts activates the corresponding vertical perceptual symbols. For self-concept, there are similar metaphors (e.g., “I am above others”). However, whether thinking about the self can induce visual attention orientation is still unknown. Therefore, the current study tested whether self-reflection can direct visual attention. Individuals often display the tendency of self-enhancement in social comparison, which reminds the individual of the higher position one possesses relative to others within the social environment. As the individual is the agent of the attention orientation, and high status tends to make an individual look down upon others to obtain a sense of pride, it was hypothesized that thinking about the self would lead to a downward attention orientation. Using reflection of personality traits and a target discrimination task, Study 1 found that, after self-reflection, visual attention was directed downward. Similar effects were also found after friend-reflection, with the level of downward attention being correlated with the likability rating scores of the friend. Thus, in Study 2, a disliked other was used as a control and the positive self-view was measured with above-average judgment task. We found downward attention orientation after self-reflection, but not after reflection upon the disliked other. Moreover, the attentional bias after self-reflection was correlated with above-average self-view. The current findings provide the first evidence that thinking about the self could direct visual-spatial attention downward, and suggest that this effect is probably derived from a positive self-view within the social context. PMID:28928694</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28928694','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28928694"><span>Self-reflection Orients Visual Attention Downward.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Yi; Tong, Yu; Li, Hong</p> <p>2017-01-01</p> <p>Previous research has demonstrated abstract concepts associated with spatial location (e.g., God in the Heavens) could direct visual attention upward or downward, because thinking about the abstract concepts activates the corresponding vertical perceptual symbols. For self-concept, there are similar metaphors (e.g., "I am above others"). However, whether thinking about the self can induce visual attention orientation is still unknown. Therefore, the current study tested whether self-reflection can direct visual attention. Individuals often display the tendency of self-enhancement in social comparison, which reminds the individual of the higher position one possesses relative to others within the social environment. As the individual is the agent of the attention orientation, and high status tends to make an individual look down upon others to obtain a sense of pride, it was hypothesized that thinking about the self would lead to a downward attention orientation. Using reflection of personality traits and a target discrimination task, Study 1 found that, after self-reflection, visual attention was directed downward. Similar effects were also found after friend-reflection, with the level of downward attention being correlated with the likability rating scores of the friend. Thus, in Study 2, a disliked other was used as a control and the positive self-view was measured with above-average judgment task. We found downward attention orientation after self-reflection, but not after reflection upon the disliked other. Moreover, the attentional bias after self-reflection was correlated with above-average self-view. The current findings provide the first evidence that thinking about the self could direct visual-spatial attention downward, and suggest that this effect is probably derived from a positive self-view within the social context.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/62391','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/62391"><span>Use of diffusive optical fibers for plant lighting</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Kozai, T.; Kitaya, Y.; Fujiwara, K.</p> <p>1994-12-31</p> <p>Lighting is one of the most critical aspects in plant production and environmental research with plants. Much research has been repeated on the effect of light intensity, spectral distribution of light and lighting cycle, but comparatively little research done on the effect of lighting direction on the growth, development and morphology of plants. When plants are grown with lamps above, light is directed downward to the plants. Downward or overhead lighting is utilized in almost all cases. However, downward lighting does not always give the best result in terms of lighting efficiency, growth, development and morphology of plants. Kitaya etmore » al. (1988) developed a lighting system in which two rooting beds were arranged; one above and the other under fluorescent lamps. Lettuce plants grew normally in the lower bed and suspended upside-down under the upper bed. The lettuce plants suspended upside-down were given the light in upward direction (upward lighting). No significant difference in growth, development and morphology was found between the lettuce plants grown by the downward and upward lighting. Combining upward and downward lighting, improved spacing efficiency and reduced electricity cost per plant compared with conventional, downward lighting. From the above example, when designing a lighting system for plants with lamps more lighting direction should be considered. In the present study, a sideward lighting system was developed using diffusive optical fiber belts. More higher quality tissue-cultured transplants could be produced in reduced space with sideward lighting system than with a downward lighting system. An application of the sideward lighting system using diffusive optical fiber belts is described and advantages and disadvantages are discussed.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4765887','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4765887"><span>How Fast Do Objects Fall in Visual Memory? Uncovering the Temporal and Spatial Features of Representational Gravity</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>De Sá Teixeira, Nuno</p> <p>2016-01-01</p> <p>Visual memory for the spatial location where a moving target vanishes has been found to be systematically displaced downward in the direction of gravity. Moreover, it was recently reported that the magnitude of the downward error increases steadily with increasing retention intervals imposed after object’s offset and before observers are allowed to perform the spatial localization task, in a pattern where the remembered vanishing location drifts downward as if following a falling trajectory. This outcome was taken to reflect the dynamics of a representational model of earth’s gravity. The present study aims to establish the spatial and temporal features of this downward drift by taking into account the dynamics of the motor response. The obtained results show that the memory for the last location of the target drifts downward with time, thus replicating previous results. Moreover, the time taken for completion of the behavioural localization movements seems to add to the imposed retention intervals in determining the temporal frame during which the visual memory is updated. Overall, it is reported that the representation of spatial location drifts downward by about 3 pixels for each two-fold increase of time until response. The outcomes are discussed in relation to a predictive internal model of gravity which outputs an on-line spatial update of remembered objects’ location. PMID:26910260</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26910260','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26910260"><span>How Fast Do Objects Fall in Visual Memory? Uncovering the Temporal and Spatial Features of Representational Gravity.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>De Sá Teixeira, Nuno</p> <p>2016-01-01</p> <p>Visual memory for the spatial location where a moving target vanishes has been found to be systematically displaced downward in the direction of gravity. Moreover, it was recently reported that the magnitude of the downward error increases steadily with increasing retention intervals imposed after object's offset and before observers are allowed to perform the spatial localization task, in a pattern where the remembered vanishing location drifts downward as if following a falling trajectory. This outcome was taken to reflect the dynamics of a representational model of earth's gravity. The present study aims to establish the spatial and temporal features of this downward drift by taking into account the dynamics of the motor response. The obtained results show that the memory for the last location of the target drifts downward with time, thus replicating previous results. Moreover, the time taken for completion of the behavioural localization movements seems to add to the imposed retention intervals in determining the temporal frame during which the visual memory is updated. Overall, it is reported that the representation of spatial location drifts downward by about 3 pixels for each two-fold increase of time until response. The outcomes are discussed in relation to a predictive internal model of gravity which outputs an on-line spatial update of remembered objects' location.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19107821','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19107821"><span>Feeding kinematics and performance of Hawaiian stream gobies, Awaous guamensis and Lentipes concolor: linkage of functional morphology and ecology.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Maie, Takashi; Wilson, Megan P; Schoenfuss, Heiko L; Blob, Richard W</p> <p>2009-03-01</p> <p>Distributions of Hawaiian stream fishes are typically interrupted by waterfalls that divide streams into multiple segments. Larvae hatch upstream, are flushed into the ocean, and must climb these waterfalls to reach adult habitats when returning back to freshwater as part of an amphidromous life cycle. Stream surveys and studies of climbing performance show that Lentipes concolor Gill can reach fast-flowing upper stream segments but that Awaous guamensis Valenciennes reaches only slower, lower stream segments. Gut content analyses for these two species indicate considerable overlap in diet, suggesting that feeding kinematics and performance of these two species might be comparable. Alternatively, feeding kinematics and performance of these species might be expected to differ in relation to the different flow regimes in their habitat (feeding in faster stream currents for L. concolor versus in slower currents for A. guamensis). To test these alternative hypotheses, we compared food capturing kinematics and performance during suction feeding behaviors of A. guamensis and L. concolor using morphological data and high-speed video. Lentipes concolor showed both a significantly larger gape angle and faster jaw opening than A. guamensis. Geometric models calculated that despite the inverse relationship of gape size and suction pressure generation, the fast jaw motions of L. concolor allow it to achieve higher pressure differentials than A. guamensis. Such elevated suction pressure would enhance the ability of L. concolor to successfully capture food in the fast stream reaches it typically inhabits. Differences in jaw morphology may contribute to these differences in performance, as the lever ratio for jaw opening is about 10% lower in L. concolor compared with A. guamensis, suiting the jaws of L. concolor better for fast opening. Copyright 2008 Wiley-Liss, Inc.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3907945','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3907945"><span>Pioneers and Followers: Migrant Selectivity and the Development of U.S. Migration Streams in Latin America</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lindstrom, David P.; Ramírez, Adriana López</p> <p>2013-01-01</p> <p>We present a method for dividing the historical development of community migration streams into an initial period and a subsequent takeoff stage with the purpose of systemically differentiating pioneer migrants from follower migrants. The analysis is organized around five basic research questions. First, can we empirically identify a juncture in the historical development of community-based migration that marks the transition from an initial stage of low levels of migration and gradual growth into a takeoff stage in which the prevalence of migration grows at a more accelerated rate? Second, does this juncture point exist at roughly similar migration prevalence levels across communities? Third, are first-time migrants in the initial stage (pioneers) different from first-time migrants in the takeoff stage (followers)? Fourth, what is the nature of this migrant selectivity? Finally, does the nature and degree of pioneer selectivity vary across country migration streams? PMID:24489382</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70121050','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70121050"><span>Biomonitors of stream quality on agricultural areas: fish versus invertebrates</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Berkman, Hilary E.; Rabeni, Charles F.; Boyle, Terence P.</p> <p>1986-01-01</p> <p>Although the utility of using either fish or benthic invertebrates as biomonitors of stream quality has been clearly shown, there is little comparative information on the usefulness of the groups in any particular situation. We compared fish to invertebrate assemblages in their ability to reflect habitat quality of sediment-impacted streams in agricultural regions of northeast Missouri, USA. Habitat quality was measured by a combination of substrate composition, riparian type, buffer strip width, and land use. Invertebrates were more sensitive to habitat differences when structural measurements, species diversity and ordination, were used. Incorporating ecological measurements, by using the Index of Biological Integrity, increased the information obtained from the fish assemblage. The differential response of the two groups was attributed to the more direct impact of sediments on invertebrate life requisites; the impact of sedimentation on fish is considered more indirect and complex, affecting feeding and reproductive mechanisms.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol15/pdf/CFR-2010-title40-vol15-sec65-162.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol15/pdf/CFR-2010-title40-vol15-sec65-162.pdf"><span>40 CFR 65.162 - Nonflare control and recovery device monitoring records.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>...). For catalytic incinerators, record the daily average of the temperature upstream of the catalyst bed and the daily average of the temperature differential across the bed. For halogen scrubbers, record... regeneration stream flow and carbon bed regeneration temperature are monitored, the following records shall be...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/873439','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/873439"><span>Fuel cell system logic for differentiating between rapid and normal shutdown commands</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Keskula, Donald H.; Doan, Tien M.; Clingerman, Bruce J.</p> <p>2000-01-01</p> <p>A method of controlling the operation of a fuel cell system wherein each shutdown command for the system is subjected to decision logic which determines whether the command should be a normal shutdown command or rapid shutdown command. If the logic determines that the shutdown command should be a normal shutdown command, then the system is shutdown in a normal step-by-step process in which the hydrogen stream is consumed within the system. If the logic determines that the shutdown command should be a rapid shutdown command, the hydrogen stream is removed from the system either by dumping to atmosphere or routing to storage.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/6161403-combined-free-forced-convection-heat-transfer-magneto-fluid-mechanic-pipe-flow','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/6161403-combined-free-forced-convection-heat-transfer-magneto-fluid-mechanic-pipe-flow"><span>Combined free and forced convection heat transfer in magneto fluid mechanic pipe flow</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Gardner, R.A.; Lo, Y.T.</p> <p>1977-01-01</p> <p>A study is made of fully developed, laminar, free-and-forced convection heat transfer in an electrically conducting fluid flowing in an electrically insulated, horizontal, circular pipe in a vertical transverse magnetic field. The normalized magnetofluidmechanic and energy equations are reduced to three coupled partial differential equations by the introduction of a stream function of the secondary flow. A perturbation solution is generated in inverse powers of the Lykoudis number, Ly = M/sup 2//..sqrt..Gr, which yields the influence of the magnetic field on the stream function of the secondary flow, axial velocity profiles, temperature profiles, and Nusselt number. 6 figures, 1 table.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720014350','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720014350"><span>A study analysis of cable-body systems totally immersed in a fluid stream</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Delaurier, J. D.</p> <p>1972-01-01</p> <p>A general stability analysis of a cable-body system immersed in a fluid stream is presented. The analytical portion of this analysis treats the system as being essentially a cable problem, with the body dynamics giving the end conditions. The mathematical form of the analysis consists of partial differential wave equations, with the end and auxiliary conditions being determined from the body equations of motion. The equations uncouple to give a lateral problem and a longitudinal problem as in first order airplane dynamics. A series of tests on a tethered wind tunnel model provide a comparison of the theory with experiment.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820002880','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820002880"><span>A study of high density bit transition requirements versus the effects on BCH error correcting coding</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ingels, F.; Schoggen, W. O.</p> <p>1981-01-01</p> <p>Several methods for increasing bit transition densities in a data stream are summarized, discussed in detail, and compared against constraints imposed by the 2 MHz data link of the space shuttle high rate multiplexer unit. These methods include use of alternate pulse code modulation waveforms, data stream modification by insertion, alternate bit inversion, differential encoding, error encoding, and use of bit scramblers. The psuedo-random cover sequence generator was chosen for application to the 2 MHz data link of the space shuttle high rate multiplexer unit. This method is fully analyzed and a design implementation proposed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920049030&hterms=lean&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dlean','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920049030&hterms=lean&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dlean"><span>Lean flammability limit of downward propagating hydrogen-air flames</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Patnaik, G.; Kailasanath, K.</p> <p>1992-01-01</p> <p>Detailed multidimensional numerical simulations that include the effects of wall heat losses have been performed to study the dynamics of downward flame propagation and extinguishment in lean hydrogen-air mixtures. The computational results show that a downward propagating flame in an isothermal channel has a flammability limit of around 9.75 percent. This is in excellent agreement with experimental results. Also in excellent agreement are the detailed observations of the flame behavior at the point of extinguishment. The primary conclusion of this work is that detailed numerical simulations that include wall heat losses and the effect of gravity can adequately simulate the dynamics of the extinguishment process in downward-propagating hydrogen-air flames. These simulations can be examined in detail to gain understanding of the actual extinction process.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/7071971','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/7071971"><span>Apparatus for measuring tensile and compressive properties of solid materials at cryogenic temperatures</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Gonczy, J.D.; Markley, F.W.; McCaw, W.R.; Niemann, R.C.</p> <p>1992-04-21</p> <p>An apparatus for evaluating the tensile and compressive properties of material samples at very low or cryogenic temperatures employs a stationary frame and a dewar mounted below the frame. A pair of coaxial cylindrical tubes extend downward towards the bottom of the dewar. A compressive or tensile load is generated hydraulically and is transmitted by the inner tube to the material sample. The material sample is located near the bottom of the dewar in a liquid refrigerant bath. The apparatus employs a displacement measuring device, such as a linear variable differential transformer, to measure the deformation of the material sample relative to the amount of compressive or tensile force applied to the sample. 7 figs.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3857858','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3857858"><span>Subglacial hydrology and the formation of ice streams</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kyrke-Smith, T. M; Katz, R. F; Fowler, A. C</p> <p>2014-01-01</p> <p>Antarctic ice streams are associated with pressurized subglacial meltwater but the role this water plays in the dynamics of the streams is not known. To address this, we present a model of subglacial water flow below ice sheets, and particularly below ice streams. The base-level flow is fed by subglacial melting and is presumed to take the form of a rough-bedded film, in which the ice is supported by larger clasts, but there is a millimetric water film which submerges the smaller particles. A model for the film is given by two coupled partial differential equations, representing mass conservation of water and ice closure. We assume that there is no sediment transport and solve for water film depth and effective pressure. This is coupled to a vertically integrated, higher order model for ice-sheet dynamics. If there is a sufficiently small amount of meltwater produced (e.g. if ice flux is low), the distributed film and ice sheet are stable, whereas for larger amounts of melt the ice–water system can become unstable, and ice streams form spontaneously as a consequence. We show that this can be explained in terms of a multi-valued sliding law, which arises from a simplified, one-dimensional analysis of the coupled model. PMID:24399921</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29884441','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29884441"><span>Neuroimaging investigations of dorsal stream processing and effects of stimulus synchrony in schizophrenia.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sanfratello, Lori; Aine, Cheryl; Stephen, Julia</p> <p>2018-05-25</p> <p>Impairments in auditory and visual processing are common in schizophrenia (SP). In the unisensory realm visual deficits are primarily noted for the dorsal visual stream. In addition, insensitivity to timing offsets between stimuli are widely reported for SP. The aim of the present study was to test at the physiological level differences in dorsal/ventral stream visual processing and timing sensitivity between SP and healthy controls (HC) using MEG and a simple auditory/visual task utilizing a variety of multisensory conditions. The paradigm included all combinations of synchronous/asynchronous and central/peripheral stimuli, yielding 4 task conditions. Both HC and SP groups showed activation in parietal areas (dorsal visual stream) during all multisensory conditions, with parietal areas showing decreased activation for SP relative to HC, and a significantly delayed peak of activation for SP in intraparietal sulcus (IPS). We also observed a differential effect of stimulus synchrony on HC and SP parietal response. Furthermore, a (negative) correlation was found between SP positive symptoms and activity in IPS. Taken together, our results provide evidence of impairment of the dorsal visual stream in SP during a multisensory task, along with an altered response to timing offsets between presented multisensory stimuli. Copyright © 2018 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70038819','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70038819"><span>Aquatic insect assemblages associated with subalpine stream segment types in relict glaciated headwaters</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Kubo, Joshua S.; Torgersen, Christian E.; Bolton, Susan M.; Weekes, Anne A.; Gara, Robert I.</p> <p>2013-01-01</p> <p>1. Aquatic habitats and biotic assemblages in subalpine headwaters are sensitive to climate and human impacts. Understanding biotic responses to such perturbations and the contribution of high-elevation headwaters to riverine biodiversity requires the assessment of assemblage composition among habitat types. We compared aquatic insect assemblages among headwater stream segment types in relict glaciated subalpine basins in Mt. Rainier National Park, Washington, USA. 2. Aquatic insects were collected during summer and autumn in three headwater basins. In each basin, three different stream segment types were sampled: colluvial groundwater sources, alluvial lake inlets, and cascade-bedrock lake outlets. Ward's hierarchical cluster analysis revealed high β diversity in aquatic insect assemblages, and non-metric multidimensional scaling indicated that spatial and temporal patterns in assemblage composition differed among headwater stream segment types. Aquatic insect assemblages showed more fidelity to stream segment types than to individual basins, and the principal environmental variables associated with assemblage structure were temperature and substrate. 3. Indicator species analyses identified specific aquatic insects associated with each stream segment type. Several rare and potentially endemic aquatic insect taxa were present, including the recently described species, Lednia borealis (Baumann and Kondratieff). 4. Our results indicate that aquatic insect assemblages in relict glaciated subalpine headwaters were strongly differentiated among stream segment types. These results illustrate the contribution of headwaters to riverine biodiversity and emphasise the importance of these habitats for monitoring biotic responses to climate change. Monitoring biotic assemblages in high-elevation headwaters is needed to prevent the potential loss of unique and sensitive biota.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007JHyd..332...30C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007JHyd..332...30C"><span>How does modifying a DEM to reflect known hydrology affect subsequent terrain analysis?</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Callow, John Nikolaus; Van Niel, Kimberly P.; Boggs, Guy S.</p> <p>2007-01-01</p> <p>SummaryMany digital elevation models (DEMs) have difficulty replicating hydrological patterns in flat landscapes. Efforts to improve DEM performance in replicating known hydrology have included a variety of soft (i.e. algorithm-based approaches) and hard techniques, such as " Stream burning" or "surface reconditioning" (e.g. Agree or ANUDEM). Using a representation of the known stream network, these methods trench or mathematically warp the original DEM to improve how accurately stream position, stream length and catchment boundaries replicate known hydrological conditions. However, these techniques permanently alter the DEM and may affect further analyses (e.g. slope). This paper explores the impact that commonly used hydrological correction methods ( Stream burning, Agree.aml and ANUDEM v4.6.3 and ANUDEM v5.1) have on the overall nature of a DEM, finding that different methods produce non-convergent outcomes for catchment parameters (such as catchment boundaries, stream position and length), and differentially compromise secondary terrain analysis. All hydrological correction methods successfully improved calculation of catchment area, stream position and length as compared to using the DEM without any modification, but they all increased catchment slope. No single method performing best across all categories. Different hydrological correction methods changed elevation and slope in different spatial patterns and magnitudes, compromising the ability to derive catchment parameters and conduct secondary terrain analysis from a single DEM. Modification of a DEM to better reflect known hydrology can be useful, however knowledge of the magnitude and spatial pattern of the changes are required before using a DEM for subsequent analyses.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26032346','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26032346"><span>Effects of Crossed Brassiere Straps on Pain, Range of Motion, and Electromyographic Activity of Scapular Upward Rotators in Women With Scapular Downward Rotation Syndrome.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kang, Min-Hyeok; Choi, Ji-Young; Oh, Jae-seop</p> <p>2015-12-01</p> <p>Scapular downward rotation syndrome manifests as an abnormally downward-rotated scapula at rest or with arm motion and typically results in neck and shoulder pain. The brassiere strap has been suggested as a possible contributing factor to scapula downward rotation and pain in the upper trapezius because of increased downward rotational force on the lateral aspect of the scapula. No study, however, has examined the influences of a modified brassiere strap on pain in and the function of the scapular muscles. To examine the effects of crossed brassiere straps on the pressure pain threshold (PPT) of the upper trapezius, neck rotation range of motion (ROM), and electromyographic activity of the scapular upward rotators in females with scapular downward rotation syndrome. Cross-over design. Laboratory. In total, 15 female subjects with scapular downward rotation syndrome were recruited at hospitals and a local university. All participants performed neck rotation and humeral elevation under 2 different conditions: parallel and crossed brassiere straps. The PPT of the upper trapezius was measured using an analog algometer, whereas neck rotation ROM was quantified with a 3-dimensional ultrasonic motion analysis system. The electromyographic activities of the upper trapezius, serratus anterior, and lower trapezius during humeral elevation were assessed with a surface electromyography system. Outcome measures were assessed under parallel and crossed brassiere strap conditions, and differences in outcomes between the conditions were analyzed using a paired t-test. The PPT and neck rotation ROM were increased when the subject was wearing the brassiere with crossed versus parallel straps (P < .001). Greater electromyographic activities of the serratus anterior, lower trapezius, and lesser upper trapezius muscles during humeral elevation were found under the crossed strap condition than the parallel strap condition (P < .05). These findings provide useful information for clinicians when designing management programs to decrease pain and improve biomechanical function for females with scapular downward rotation syndrome. Copyright © 2015 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150022123','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150022123"><span>Buoyant Effects on the Flammability of Silicone Samples Planned for the Spacecraft Fire Experiment (Saffire)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Niehaus, Justin; Ferkul, Paul V.; Gokoglu, Suleyman; Ruff, Gary</p> <p>2015-01-01</p> <p>Flammability experiments on silicone samples were conducted in anticipation of the Spacecraft Fire Experiment (Saffire). The sample geometry was chosen to match the NASA 6001 Test 1 specification, namely 5 cm wide by 30 cm tall. Four thicknesses of silicone (0.25, 0.36, 0.61 and 1.00 mm) were examined. Tests included traditional upward buoyant flame spread using Test 1 procedures, downward opposed flow flame spread, horizontal and angled flame spread, forced flow upward and downward flame spread. In addition to these configurations, upward and downward tests were also conducted in a chamber with varying oxygen concentrations. In the upward buoyant flame spread tests, the flame generally did not burn the entire sample. As thickness was increased, the flame spread distance decreased before flame extinguishment. For the thickest sample, ignition could not be achieved. In the downward tests, the two thinnest samples permitted the flame to burn the entire sample, but the spread rate was lower compared to the corresponding upward values. The other two thicknesses could not be ignited in the downward configuration. The increased flammability for downward spreading flames relative to upward ones is uncommon. The two thinnest samples also burned completely in the horizontal configuration, as well as at angles up to 75 degrees from the horizontal. The upward and downward flammability behavior was compared in atmospheres of varying oxygen concentration to determine a maximum oxygen concentration for each configuration. Upward tests in air with an added forced flow were more flammable. Complementary analyses using SEM and TGA techniques suggest the importance of the silica layer formed on the burned sample surface. As silicone burns upward, silica deposits downstream •If the silicone is ignited in the downward configuration, it burns the entire length of the sample •Burning upward at an angle increases the burn length in some cases possibly due to less silica deposition •Forced flow in the upward burning case increases flammability, likely due to an increase in convective flow preventing silica from depositing •Samples in upward configuration burning under forced flow self extinguish after forced flow is removed</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/5377185-drill-drive-mechanism','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/5377185-drill-drive-mechanism"><span>Drill drive mechanism</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Dressel, M.O.</p> <p>1979-10-30</p> <p>A drill drive mechanism is especially adapted to provide both rotational drive and axial feed for a drill of substantial diameter such as may be used for drilling holes for roof bolts in mine shafts. The drill shaft is made with a helical pattern of scroll-like projections on its surface for removal of cuttings. The drill drive mechanism includes a plurality of sprockets carrying two chains of drive links which are arranged to interlock around the drill shaft with each drive link having depressions which mate with the scroll-like projections. As the chain links move upwardly or downwardly the surfacesmore » of the depressions in the links mate with the scroll projections to move the shaft axially. Tangs on the drive links mate with notch surfaces between scroll projections to provide a means for rotating the shaft. Projections on the drive links mate together at the center to hold the drive links tightly around the drill shaft. The entire chain drive mechanism is rotated around the drill shaft axis by means of a hydraulic motor and gear drive to cause rotation of the drill shaft. This gear drive also connects with a differential gearset which is interconnected with a second gear. A second motor is connected to the spider shaft of the different gearset to produce differential movement (speeds) at the output gears of the differential gearset. This differential in speed is utilized to drive said second gear at a speed different from the speed of said gear drive, this speed differential being utilized to drive said sprockets for axial movement of said drill shaft. 11 claims.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/wri/1988/4093/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/wri/1988/4093/report.pdf"><span>Hydrogeology and water quality near a solid- and hazardous-waste landfill, Northwood, Ohio</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>De Roche, J.T.; Breen, K.J.</p> <p>1989-01-01</p> <p>Hydrogeology and water quality of ground water and selected streams were evaluated near a landfill in northwestern Ohio. The landfill is used for codisposal of solid and hazardous waste. Water-level and geologic data were collected from 36 wells and 3 surface-water sites during the period November 1983 to November 1985. Water-quality samples were collected from 18 wells and 3 surface-water sites this during this same period. The primary aquifers in the area are the Greenfield Dolomite and underlying Lockport Dolomite of Silurian age. These bedrock carbonates are overlain by two clay tills of Wisconsin age. The tills are capped by a glacial lake clay. The tills generally are saturated, but do not yield sufficient water to be considered an aquifer. Two wells in the study area yield water, in part, from discontinuous deposits of outwash sand and gravel at the lower till-bedrock interface. Regional ground-water flow is from southwest to northeast; local flow is influenced by a ground-water mound centered under the northernmost cells of the landfill. Water levels in wells penetrating refuse within the landfill and the presence of leachate seeps indicate that the refuse is saturated. Head relations among the landfill, till, and dolomite aquifer indicate a vertical component of flow downward from the landfill to the dolomite aquifer. Water levels near the landfill fluctuate as much as 14 feet per year, in contrast to fluctuations of less than 3 feet per year in wells upgradient landfill. Ground waters from wells completed in the dolomite aquifer and glacial till were found to have major-iron concentrations controlled, in large part, by reaction with calcite, dolomite, and other minerals in the aquifer. Only minor departures from equilibrium mineral saturation were noted for ground water, except in wells affected by cement/grout contamination. Molal ratios of calcuim:magnesium in ground water suggest a similar chemical evolution of waters throughout the dolomite aquifer in the study area. Stable-isotope ratios of oxygen and hydrogen indicate the source of water in the till unit and dolomite aquifer is atmospheric precipitation. Elevated levels of total dissolved solids, boron, ammonia, and iron in the leachate and in wells downgradient of the landfill may indicate mixing of ground water with leachate. Oxygen and hydrogen stable-isotope ratios were used to differentiate waters from the glacial till and dolomite aquifer. Isotope ratios also show a shift off the local mixing line for leachate and for a well just downgradient from the landfill. The shift to heavier values of o D in the well water may be indicative of leachate mixing with ground water. The effect of this mixing denoted by hydrologic, isotopic, and chemical-quality data is limited mostly to elevated levels of the common ions. Analysis did not indicate significant levels of toxic metals or organic contaminants except phenol, which was present at concentrations of from 1 to 5 micrograms per liter in six wells. Analysis of water-quality data from nearby streams suggest that surface leaching from the landfill does not significantly affect stream-water quality, but may contribute to higher level of trace metals in the streambed sediments.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20030032939','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20030032939"><span>Solar Energetic Particle Variations</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Reames, D. V.</p> <p>2003-01-01</p> <p>In the largest solar energetic-particle (SEP) events, acceleration occurs at shock waves driven out from the Sun by coronal mass ejections (CMEs). In fact, the highest proton intensities directly measured near Earth at energies up to approximately 1 GeV occur at the time of passage of shocks, which arrive about a day after the CMEs leave the Sun. CME-driven shocks expanding across magnetic fields can fill over half of the heliosphere with SEPs. Proton-generated Alfven waves trap particles near the shock for efficient acceleration but also throttle the intensities at Earth to the streaming limit early in the events. At high energies, particles begin to leak from the shock and the spectrum rolls downward to form an energy-spectral 'knee' that can vary in energy from approximately 1 MeV to approximately 1 GeV in different events. All of these factors affect the radiation dose as a function of depth and latitude in the Earth's atmosphere and the risk to astronauts and equipment in space. SEP ionization of the polar atmosphere produces nitrates that precipitate to become trapped in the polar ice. Observations of nitrate deposits in ice cores reveal individual large SEP events and extend back approximately 400 years. Unlike sunspots, SEP events follow the approximately 80-100-year Gleissberg cycle rather faithfully and are now at a minimum in that cycle. The largest SEP event in the last 400 years appears to be related to the flare observed by Carrington in 1859, but the probability of SEP events with such large fluences falls off sharply because of the streaming limit.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017WRR....53.7607L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017WRR....53.7607L"><span>Direct measurements of lift and drag on shallowly submerged cobbles in steep streams: Implications for flow resistance and sediment transport</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lamb, Michael P.; Brun, Fanny; Fuller, Brian M.</p> <p>2017-09-01</p> <p>Steep mountain streams have higher resistance to flow and lower sediment transport rates than expected by comparison with low gradient rivers, and often these differences are attributed to reduced near-bed flow velocities and stresses associated with form drag on channel forms and immobile boulders. However, few studies have directly measured drag and lift forces acting on bed sediment for shallow flows over coarse sediment, which ultimately control sediment transport rates and grain-scale flow resistance. Here we report on particle lift and drag force measurements in flume experiments using a planar, fixed cobble bed over a wide range of channel slopes (0.004 < S < 0.3) and water discharges. Drag coefficients are similar to previous findings for submerged particles (CD ˜ 0.7) but increase significantly for partially submerged particles. In contrast, lift coefficients decrease from near unity to zero as the flow shallows and are strongly negative for partially submerged particles, indicating a downward force that pulls particles toward the bed. Fluctuating forces in lift and drag decrease with increasing relative roughness, and they scale with the depth-averaged velocity squared rather than the bed shear stress. We find that, even in the absence of complex bed topography, shallow flows over coarse sediment are characterized by high flow resistance because of grain drag within a roughness layer that occupies a significant fraction of the total flow depth, and by heightened critical Shields numbers and reduced sediment fluxes because of reduced lift forces and reduced turbulent fluctuations.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110012934','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110012934"><span>Ice-Borehole Probe</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Behar, Alberto; Carsey, Frank; Lane, Arthur; Engelhardt, Herman</p> <p>2006-01-01</p> <p>An instrumentation system has been developed for studying interactions between a glacier or ice sheet and the underlying rock and/or soil. Prior borehole imaging systems have been used in well-drilling and mineral-exploration applications and for studying relatively thin valley glaciers, but have not been used for studying thick ice sheets like those of Antarctica. The system includes a cylindrical imaging probe that is lowered into a hole that has been bored through the ice to the ice/bedrock interface by use of an established hot-water-jet technique. The images acquired by the cameras yield information on the movement of the ice relative to the bedrock and on visible features of the lower structure of the ice sheet, including ice layers formed at different times, bubbles, and mineralogical inclusions. At the time of reporting the information for this article, the system was just deployed in two boreholes on the Amery ice shelf in East Antarctica and after successful 2000 2001 deployments in 4 boreholes at Ice Stream C, West Antarctica, and in 2002 at Black Rapids Glacier, Alaska. The probe is designed to operate at temperatures from 40 to +40 C and to withstand the cold, wet, high-pressure [130-atm (13.20-MPa)] environment at the bottom of a water-filled borehole in ice as deep as 1.6 km. A current version is being outfitted to service 2.4-km-deep boreholes at the Rutford Ice Stream in West Antarctica. The probe (see figure) contains a sidelooking charge-coupled-device (CCD) camera that generates both a real-time analog video signal and a sequence of still-image data, and contains a digital videotape recorder. The probe also contains a downward-looking CCD analog video camera, plus halogen lamps to illuminate the fields of view of both cameras. The analog video outputs of the cameras are converted to optical signals that are transmitted to a surface station via optical fibers in a cable. Electric power is supplied to the probe through wires in the cable at a potential of 170 VDC. A DC-to-DC converter steps the supply down to 12 VDC for the lights, cameras, and image-data-transmission circuitry. Heat generated by dissipation of electric power in the probe is removed simply by conduction through the probe housing to the visible features of the lower structure of the ice sheet, including ice layers formed at different times, bubbles, and mineralogical inclusions. At the time of reporting the information for this article, the system was just deployed in two boreholes on the Amery ice shelf in East Antarctica and after successful 2000 2001 deployments in 4 boreholes at Ice Stream C, West Antarctica, and in 2002 at Black Rapids Glacier, Alaska. The probe is designed to operate at temperatures from 40 to +40 C and to withstand the cold, wet, high-pressure [130-atm (13.20-MPa)] environment at the bottom of a water-filled borehole in ice as deep as 1.6 km. A current version is being outfitted to service 2.4-km-deep boreholes at the Rutford Ice Stream in West Antarctica. The probe (see figure) contains a sidelooking charge-coupled-device (CCD) camera that generates both a real-time analog video signal and a sequence of still-image data, and contains a digital videotape recorder. The probe also contains a downward-looking CCD analog video camera, plus halogen lamps to illuminate the fields of view of both cameras. The analog video outputs of the cameras are converted to optical signals that are transmitted to a surface station via optical fibers in a cable. Electric power is supplied to the probe through wires in the cable at a potential of 170 VDC. A DC-to-DC converter steps the supply down to 12 VDC for the lights, cameras, and image-datatransmission circuitry. Heat generated by dissipation of electric power in the probe is removed simply by conduction through the probe housing to the visible features of the lower structure of the ice sheet, including ice layers formed at different times, bubbles, and mineralogical inclusions. At thime of reporting the information for this article, the system was just deployed in two boreholes on the Amery ice shelf in East Antarctica and after successful 2000 2001 deployments in 4 boreholes at Ice Stream C, West Antarctica, and in 2002 at Black Rapids Glacier, Alaska. The probe is designed to operate at temperatures from 40 to +40 C and to withstand the cold, wet, high-pressure [130-atm (13.20-MPa)] environment at the bottom of a water-filled borehole in ice as deep as 1.6 km. A current version is being outfitted to service 2.4-km-deep boreholes at the Rutford Ice Stream in West Antarctica. The probe (see figure) contains a sidelooking charge-coupled-device (CCD) camera that generates both a real-time analog video signal and a sequence of still-image data, and contains a digital videotape recorder. The probe also contains a downward-looking CCD analog video camera, plus halogen lamps to illuminate the fields of view of both cameras. The analog video outputs of the cameras are converted to optical signals that are transmitted to a surface station via optical fibers in a cable. Electric power is supplied to the probe through wires in the cable at a potential of 170 VDC. A DC-to-DC converter steps the supply down to 12 VDC for the lights, cameras, and image-datatransmission circuitry. Heat generated by dissipation of electric power in the probe is removed simply by conduction through the probe housing to the adjacent water and ice.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18585108','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18585108"><span>An ecological momentary assessment of comparison target as a moderator of the effects of appearance-focused social comparisons.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Leahey, Tricia M; Crowther, Janis H</p> <p>2008-09-01</p> <p>This research examined whether comparison target moderates the effects of naturally occurring appearance-focused social comparisons on women's affect, appearance esteem, and dieting thoughts. During daily activities, body-satisfied (BS) women and body-dissatisfied (BD) women recorded their comparison targets and reactions to comparison information. For BS women, upward comparisons with peers were associated with more positive affect (PA) and appearance esteem and less guilt than upward comparisons with media images and downward comparisons with peers were associated with less PA than downward comparisons with media images. For BD women, upward comparisons with peers were associated with more appearance esteem and diet thoughts than upward comparisons with media images and downward comparisons with peers were associated with less PA, appearance esteem, and diet thoughts and more guilt than downward comparisons with media images.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19900011225','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19900011225"><span>Downward continuation of the free-air gravity anomalies to the ellipsoid using the gradient solution and terrain correction: An attempt of global numerical computations</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wang, Y. M.</p> <p>1989-01-01</p> <p>The formulas for the determination of the coefficients of the spherical harmonic expansion of the disturbing potential of the earth are defined for data given on a sphere. In order to determine the spherical harmonic coefficients, the gravity anomalies have to be analytically downward continued from the earth's surface to a sphere-at least to the ellipsoid. The goal is to continue the gravity anomalies from the earth's surface downward to the ellipsoid using recent elevation models. The basic method for the downward continuation is the gradient solution (the g sub 1 term). The terrain correction was also computed because of the role it can play as a correction term when calculating harmonic coefficients from surface gravity data. The fast Fourier transformation was applied to the computations.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16897299','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16897299"><span>Microbial availability and size fractionation of dissolved organic carbon after drought in an intermittent stream: biogeochemical link across the stream-riparian interface.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Romaní, Anna M; Vázquez, Eusebi; Butturini, Andrea</p> <p>2006-10-01</p> <p>The evolution of dissolved organic carbon (DOC) molecular-weight fractions, DOC biodegradability (BDOC), DOC origin [fluorescence index (FI)], and enzyme activities between the stream waters (main and ephemeral channel) and ground waters (riparian and hillslope) were analyzed during the transition from drought to precipitation in a forested Mediterranean stream. After the first rains, DOC content in stream water reached its maximum value (10-18 mg L(-1)), being explained by the leaching of deciduous leaves accumulated on the stream bed during drought. During this period, the largest molecules (>10 kDa), were the most biodegradable, as indicated by high BDOC values measured during storm events and high enzymatic activities (especially for leucine-aminopeptidase). DOC >100 kDa was strongly immobilized (78%) at the stream-riparian interface, whereas the smallest molecules (<1 kDa) were highly mobile and accumulated in ground waters, indicating their greater recalcitrance. Differential enzymatic patterns between compartments showed a fast utilization of polysaccharides in the flowing water but a major protein utilization in the ground water. The results of the FI indicated a more terrestrial origin of the larger molecules in the flowing water, also suggesting that transformation of material occurs through the stream-riparian interface. Microbial immobilization and fast utilization of the most biodegradable fraction at the stream-riparian interface is suggested as a relevant DOC retention mechanism just after initial recharging of the ground water compartment. Large and rapid DOC inputs entering the intermittent river system during the transition from drought to precipitation provide available N and C sources for the heterotrophs. Heterotrophs efficiently utilize these resources that were in limited supply during the period of drought. Such changes in C cycling may highlight possible changes in organic matter dynamics under the prediction of extended drying periods in aquatic ecosystems.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.H41H..07S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.H41H..07S"><span>Comparing solute and particulate transport in streams using Notre Dame Linked Experimental Ecosystem Facility (ND-LEEF)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shogren, A.; Tank, J. L.; Aubeneau, A. F.; Bolster, D.</p> <p>2016-12-01</p> <p>in streams and rivers. These processes co-vary across systems and are thus difficult to isolate. Therefore, to improve our understanding of drivers of fine-scale transport and retention of particles and solutes in streams, we experimentally compared transport and retention dynamics of two different particles (brewers yeast, 7μm; corn pollen, 70μm), a non-reactive solute (RhodamineWT), and a biologically reactive solute, nitrate (NO3-). We conducted experiments in four semi-natural constructed streams at the Notre Dame Linked Ecosystem Experimental Facility (ND-LEEF) in South Bend, Indiana. Each of the four 50 m replicate stream was lined with a unique configuration of substrate: pea gravel (PG, D50 = 0.5cm) and cobble (COB, D50 = 5cm) and structural complexity: alternating 2m sections of PG and COB substrates (ALT) and a random 50/50 mix (MIX). We allowed the experimental streams to naturally colonize with biofilm and periphyton throughout the summer sampling season. For particles, we estimated transport distance (Sp) and deposition velocity (vdep) and for solutes, we estimated uptake lengths (Sw) and uptake velocity (vf) using a short-term pulse addition technique. Sp and vdep were variable for particles, and were most strongly predicted by biofilm colonization on substrata in each stream. Biofilm accumulation also increased uptake of the reactive solute, though in contrast to particles, there were no significant differences in Sw or vf among streams suggesting that substrate type was not the main driver of reactive solute retention. These results emphasize the dynamic relationship between the physical and biological drivers influencing particle and solute retention in streams. Differential uptake of particles and solutes highlights the non stationarity of controlling variables along spatial or temporal continua. Even in highly controlled systems like those at ND-LEEF, physical vs. biological drivers are difficult to isolate.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27429092','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27429092"><span>Vulnerability of stream community composition and function to projected thermal warming and hydrologic change across ecoregions in the western United States.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pyne, Matthew I; Poff, N LeRoy</p> <p>2017-01-01</p> <p>Shifts in biodiversity and ecological processes in stream ecosystems in response to rapid climate change will depend on how numerically and functionally dominant aquatic insect species respond to changes in stream temperature and hydrology. Across 253 minimally perturbed streams in eight ecoregions in the western USA, we modeled the distribution of 88 individual insect taxa in relation to existing combinations of maximum summer temperature, mean annual streamflow, and their interaction. We used a heat map approach along with downscaled general circulation model (GCM) projections of warming and streamflow change to estimate site-specific extirpation likelihood for each taxon, allowing estimation of whole-community change in streams across these ecoregions. Conservative climate change projections indicate a 30-40% loss of taxa in warmer, drier ecoregions and 10-20% loss in cooler, wetter ecoregions where taxa are relatively buffered from projected warming and hydrologic change. Differential vulnerability of taxa with key functional foraging roles in processing basal resources suggests that climate change has the potential to modify stream trophic structure and function (e.g., alter rates of detrital decomposition and algal consumption), particularly in warmer and drier ecoregions. We show that streamflow change is equally as important as warming in projected risk to stream community composition and that the relative threat posed by these two fundamental drivers varies across ecoregions according to projected gradients of temperature and hydrologic change. Results also suggest that direct human modification of streams through actions such as water abstraction is likely to further exacerbate loss of taxa and ecosystem alteration, especially in drying climates. Management actions to mitigate climate change impacts on stream ecosystems or to proactively adapt to them will require regional calibration, due to geographic variation in insect sensitivity and in exposure to projected thermal warming and hydrologic change. © 2016 John Wiley & Sons Ltd.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70044405','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70044405"><span>Hydrogeomorphology of the hyporheic zone: stream solute and fine particle interactions with a dynamic streambed</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Harvey, J.W.; Drummond, J.D.; Martin, R.L.; McPhillips, L.E.; Packman, A.I.; Jerolmack, D.J.; Stonedahl, S.H.; Aubeneau, A.F.; Sawyer, A.H.; Larsen, L.G.; Tobias, C.R.</p> <p>2012-01-01</p> <p>Hyporheic flow in streams has typically been studied separately from geomorphic processes. We investigated interactions between bed mobility and dynamic hyporheic storage of solutes and fine particles in a sand-bed stream before, during, and after a flood. A conservatively transported solute tracer (bromide) and a fine particles tracer (5 μm latex particles), a surrogate for fine particulate organic matter, were co-injected during base flow. The tracers were differentially stored, with fine particles penetrating more shallowly in hyporheic flow and retained more efficiently due to the high rate of particle filtration in bed sediment compared to solute. Tracer injections lasted 3.5 h after which we released a small flood from an upstream dam one hour later. Due to shallower storage in the bed, fine particles were rapidly entrained during the rising limb of the flood hydrograph. Rather than being flushed by the flood, we observed that solutes were stored longer due to expansion of hyporheic flow paths beneath the temporarily enlarged bedforms. Three important timescales determined the fate of solutes and fine particles: (1) flood duration, (2) relaxation time of flood-enlarged bedforms back to base flow dimensions, and (3) resulting adjustments and lag times of hyporheic flow. Recurrent transitions between these timescales explain why we observed a peak accumulation of natural particulate organic matter between 2 and 4 cm deep in the bed, i.e., below the scour layer of mobile bedforms but above the maximum depth of particle filtration in hyporheic flow paths. Thus, physical interactions between bed mobility and hyporheic transport influence how organic matter is stored in the bed and how long it is retained, which affects decomposition rate and metabolism of this southeastern Coastal Plain stream. In summary we found that dynamic interactions between hyporheic flow, bed mobility, and flow variation had strong but differential influences on base flow retention and flood mobilization of solutes and fine particulates. These hydrogeomorphic relationships have implications for microbial respiration of organic matter, carbon and nutrient cycling, and fate of contaminants in streams.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMSH31D..03G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMSH31D..03G"><span>Voyager 1 Observations of a Recent Transient Disturbance in the Interstellar Medium Caused by an Energetic Solar Event</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gurnett, D. A.; Kurth, W. S.; Stone, E. C.; Cummings, A. C.; Krimigis, S. M.; Decker, R. B.; Ness, N. F.; Burlaga, L. F.</p> <p>2016-12-01</p> <p>In late August 2012 the Voyager 1 spacecraft crossed the heliopause into the nearby interstellar medium. Since then the spacecraft has detected four distinct particle and field disturbances in the interstellar plasma, each believed to be produced by a shock originating from a solar event. Here we describe the fourth and most recent of these events. This event was first identified in the Low Energy Charged Particle (LECP) and Cosmic Ray (CRS) data around day 1, 2015, by the onset of a gradual downward trend in the intensity of galactic cosmic rays near 90° pitch angles. This decrease was briefly interrupted by a small recovery, and then resumed the decrease on day 100, 2015. The downward trend was followed about half a year later by the onset of intense bursts of electron plasma oscillations on day 250, 2015. The plasma oscillations continued with high intensities, the highest intensities yet observed, to about day 310, 2015, where they abruptly ended. The oscillation frequency was around 3.0 kHz, which corresponds to a local electron density of 0.11 cm-3, the highest yet measured in the interstellar medium. Near the end of the year, day 1, 2016, the downward trend in the 90° cosmic ray intensities reversed and started increasing, but has not yet returned to isotropy as of this writing. At the minimum, the 90° cosmic ray intensity at 200 MeV was depressed about 10% below the isotropic value. Overall, the new event has very similar characteristics to the three previous events, although differing in some details and of somewhat longer in duration. Most striking is the depression in the cosmic ray intensity near 90° pitch angles which in every case precedes the onset of the electron plasma oscillations. Since the electron plasma oscillations have been widely interpreted as being driven by electron beams streaming out ahead of an approaching shock (two of which have been directly detected), it appears that the depression in the cosmic ray intensities near 90° pitch angles is a precursor effect caused by reflection of cosmic rays from the magnetic field jump at the shock. Based on previous observations the shock is expected to be detected in the magnetic field around the time that the cosmic ray intensity becomes isotropic. However, as of the last magnetic field data processed, Jan. 1, 2016, no shock had been detected.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JMSA..tmp...14C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JMSA..tmp...14C"><span>Comparison of Scour and Flow Characteristics Around Circular and Oblong Bridge Piers in Seepage Affected Alluvial Channels</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chavan, Rutuja; Venkataramana, B.; Acharya, Pratik; Kumar, Bimlesh</p> <p>2018-06-01</p> <p>The present study examines scour geometry and turbulent flow characteristics around circular and oblong piers in alluvial channel with downward seepage. Experiments were conducted in plane sand bed of non-uniform sand under no seepage, 10% seepage and 15% seepage conditions. Scour depth at oblong pier is significantly lesser than the scour depth at circular one. However, the scour depth at both piers reduces with downward seepage. The measurements show that the velocity and Reynolds stresses are negative near the bed at upstream of piers where the strong reversal occurs. At downstream of oblong pier near the free surface, velocity and Reynolds stresses are less positive; whereas, they are negative at downstream of circular pier. The streamline shape of oblong pier leads to reduce the strength of wake vortices and consequently reversal flow at downstream of pier. With application of downward seepage turbulent kinetic energy is decreasing. The results show that the wake vortices at oblong pier are weaker than the wake vortices at circular pier. The strength of wake vortices diminishes with downward seepage. The Strouhal number is lesser for oblong pier and decreases with downward seepage for both oblong and circular piers.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/46096','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/46096"><span>Network analysis reveals multiscale controls on streamwater chemistry</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Kevin J. McGuire; Christian E. Torgersen; Gene E. Likens; Donald C. Buso; Winsor H. Lowe; Scott W. Bailey</p> <p>2014-01-01</p> <p>By coupling synoptic data from a basin-wide assessment of streamwater chemistry with network-based geostatistical analysis, we show that spatial processes differentially affect biogeochemical condition and pattern across a headwater stream network. We analyzed a high-resolution dataset consisting of 664 water samples collected every 100 m throughout 32 tributaries in...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA597116','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA597116"><span>Path Diversity Media Streaming over Best Effort Packet Switched Networks</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2003-01-01</p> <p>intolerable sounds of my violin practice, but my mom was always there to defend and encourage her young violinist. When I left my full-time job for graduate...information can be incomplete or inaccurate. For exam - ple, traceroute can only differentiate between routers and not switches. Two paths with completely</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2010-04-16/pdf/2010-8683.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2010-04-16/pdf/2010-8683.pdf"><span>75 FR 20016 - Self-Regulatory Organizations; Notice of Filing of Proposed Rule Change by NASDAQ OMX PHLX, Inc...</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2010-04-16</p> <p>...)(i)(A) a provision relating to $5 wide bid-ask differentials for electronic quotes in equity, index... believes that these changes are appropriate because quoting has become entirely electronic; most Streaming... as one single offense, for purposes of initiating disciplinary action under Exchange rules, or...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26096382','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26096382"><span>Temporal Hyporheic Zone Response to Water Table Fluctuations.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Malzone, Jonathan M; Anseeuw, Sierra K; Lowry, Christopher S; Allen-King, Richelle</p> <p>2016-03-01</p> <p>Expansion and contraction of the hyporheic zone due to temporal hydrologic changes between stream and riparian aquifer influence the biogeochemical cycling capacity of streams. Theoretical studies have quantified the control of groundwater discharge on the depth of the hyporheic zone; however, observations of temporal groundwater controls are limited. In this study, we develop the concept of groundwater-dominated differential hyporheic zone expansion to explain the temporal control of groundwater discharge on the hyporheic zone in a third-order stream reach flowing through glacially derived terrain typical of the Great Lakes region. We define groundwater-dominated differential expansion of the hyporheic zone as: differing rates and magnitudes of hyporheic zone expansion in response to seasonal vs. storm-related water table fluctuation. Specific conductance and vertical hydraulic gradient measurements were used to map changes in the hyporheic zone during seasonal water table decline and storm events. Planar and riffle beds were monitored in order to distinguish the cause of increasing hyporheic zone depth. Planar bed seasonal expansion of the hyporheic zone was of a greater magnitude and longer in duration (weeks to months) than storm event expansion (hours to days). In contrast, the hyporheic zone beneath the riffle bed exhibited minimal expansion in response to seasonal groundwater decline compared to storm related expansion. Results indicated that fluctuation in the riparian water table controlled seasonal expansion of the hyporheic zone along the planar bed. This groundwater induced hyporheic zone expansion could increase the potential for biogeochemical cycling and natural attenuation. © 2015, National Ground Water Association.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26809574','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26809574"><span>Cooperation and information replication in wireless networks.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Poularakis, Konstantinos; Tassiulas, Leandros</p> <p>2016-03-06</p> <p>A significant portion of today's network traffic is due to recurring downloads of a few popular contents. It has been observed that replicating the latter in caches installed at network edges-close to users-can drastically reduce network bandwidth usage and improve content access delay. Such caching architectures are gaining increasing interest in recent years as a way of dealing with the explosive traffic growth, fuelled further by the downward slope in storage space price. In this work, we provide an overview of caching with a particular emphasis on emerging network architectures that enable caching at the radio access network. In this context, novel challenges arise due to the broadcast nature of the wireless medium, which allows simultaneously serving multiple users tuned into a multicast stream, and the mobility of the users who may be frequently handed off from one cell tower to another. Existing results indicate that caching at the wireless edge has a great potential in removing bottlenecks on the wired backbone networks. Taking into consideration the schedule of multicast service and mobility profiles is crucial to extract maximum benefit in network performance. © 2016 The Author(s).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/wri/1980/0059/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/wri/1980/0059/report.pdf"><span>A water-quality monitoring network for Vallecitos Valley, Alameda County, California</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Farrar, C.D.</p> <p>1980-01-01</p> <p>A water-quality monitoring network is proposed to detect the presence of and trace the movement of radioisotopes in the hydrologic system in the vicinity of the Vallecitos Nuclear Center. The source of the radioisotopes is treated industrial wastewater from the Vallecitos Nuclear Center that is discharged into an unnamed tributary of Vallecitos Creek. The effluent infiltrates the alluvium along the stream course, percolates downward to the water table, and mixes with the native ground water in the subsurface. The average daily discharge of effluent to the hydrologic system in 1978 was about 100,000 gallons. In Vallecitos Valley, the Livermore Gravel and the overlying alluvium constitute the ground-water reservoir. There is no subsurface inflow from adjacent ground-water basins. Ground-water flow in the Vallecitos subbasin is toward the southwest.The proposed network consists of four surface-water sampling sites and six wells to sample the ground-water system. Samples collected monthly at each site and analyzed for tritium and for alpha, beta, and gamma radiation would provide adequate data for monitoring.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20090011189','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20090011189"><span>Processing Ocean Images to Detect Large Drift Nets</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Veenstra, Tim</p> <p>2009-01-01</p> <p>A computer program processes the digitized outputs of a set of downward-looking video cameras aboard an aircraft flying over the ocean. The purpose served by this software is to facilitate the detection of large drift nets that have been lost, abandoned, or jettisoned. The development of this software and of the associated imaging hardware is part of a larger effort to develop means of detecting and removing large drift nets before they cause further environmental damage to the ocean and to shores on which they sometimes impinge. The software is capable of near-realtime processing of as many as three video feeds at a rate of 30 frames per second. After a user sets the parameters of an adjustable algorithm, the software analyzes each video stream, detects any anomaly, issues a command to point a high-resolution camera toward the location of the anomaly, and, once the camera has been so aimed, issues a command to trigger the camera shutter. The resulting high-resolution image is digitized, and the resulting data are automatically uploaded to the operator s computer for analysis.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRD..122.3481Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRD..122.3481Y"><span>Analysis of the lightning-attractive radius for wind turbines considering the developing process of positive attachment leader</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, Ning; Zhang, Qilin; Hou, Wenhao; Wen, Ying</p> <p>2017-03-01</p> <p>In this paper, we have presented the upward leader propagation model, considering the transition of stream leader process by the finite element method and analyzing the inception and subsequent physical processes of upward leader and the attractive radius for large wind turbines. For validating our model, the comparison of simulated results with the optically high-speed video observation shows that the model can predict an accepted result of upward leader from a 163 m tall tower, the simulated upward leader velocity and length before final jump are 2.3 × 105 m/s and 187.67 m presented by Warner (2010), which are very similar to the observed results of 2.8 × 105 m/s and 184 m, respectively. At the same time, we find that the assumed constant speed ratio of downward/upward leader is improper and cannot accurately predict the attractive radius by lightning strike. Also, the simulated results are compared with the widely used EGM (electro geometric model), and it is found that the EGM has an obvious underestimation of attractive radius more than 50%.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70004721','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70004721"><span>Book review: Estimating groundwater recharge</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Stonestrom, David A.</p> <p>2011-01-01</p> <p>Groundwater recharge is the entry of fresh water into the saturated portion of the subsurface part of the hydrologic cycle, the modifier “saturated” indicating that the pressure of the pore water is greater than atmospheric. Briefly stated, recharge is downward flux across the water table. The term “groundwater recharge” can refer either to the multiple interacting processes generating and controlling the flux or to the fluxR itself. When referring to flux, R can represent either (1) a value integrated over large areas and long periods of time or (2) a point value, or instantaneous flux density, that varies erratically as well as continuously in time and space. Knowing how R is distributed through space and time is required for understanding the dynamics of groundwater flow and transport in any watershed, aquifer, or selected domain of interest and for understanding heads, flow paths, and discharges to streams, wetlands, and other surface water bodies. Clearly among the most important of hydrologic fluxes, R is also one of the most difficult to measure. Advancements in hydrologic science have proceeded surprisingly in lockstep with advances in determining R.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://eric.ed.gov/?q=aggregate+AND+supply&id=EJ330574','ERIC'); return false;" href="https://eric.ed.gov/?q=aggregate+AND+supply&id=EJ330574"><span>The Aggregate Supply Curve: Keynes and Downwardly Sticky Money Wages.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Wells, Paul</p> <p>1985-01-01</p> <p>Keynes's explanation of both the rationale underlying downwardly sticky money wages and the consequences this phenomenon has for macroeconomic theory are reviewed. An aggregate supply curve appropriate to today's economy is then interpreted. (Author/RM)</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/869577','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/869577"><span>Controlled catalytic and thermal sequential pyrolysis and hydrolysis of polymer waste comprising nylon 6 and a polyolefin or mixtures of polyolefins to sequentially recover monomers or other high value products</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Evans, Robert J.; Chum, Helena L.</p> <p>1994-01-01</p> <p>A process of using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents; selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feedstream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/6827760','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/biblio/6827760"><span>Controlled catalytic and thermal sequential pyrolysis and hydrolysis of polymer waste comprising nylon 6 and a polyolefin or mixtures of polyolefins to sequentially recover monomers or other high value products</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Evans, R.J.; Chum, H.L.</p> <p>1994-10-25</p> <p>A process of using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents; selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feedstream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent. 83 figs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960011721','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960011721"><span>Use of diffusive optical fibers for plant lighting</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kozai, T.; Kitaya, Y.; Fujiwara, K.; Kino, S.; Kinowaki, M.</p> <p>1994-01-01</p> <p>Lighting is one of the most critical aspects in plant production and environmental research with plants. Much research has been repeated on the effect of light intensity, spectral distribution of light and lighting cycle, but comparatively little research done on the effect of lighting direction on the growth, development and morphology of plants. When plants are grown with lamps above, light is directed downward to the plants. Downward or overhead lighting is utilized in almost all cases. However, downward lighting does not always give the best result in terms of lighting efficiency, growth, development and morphology of plants. In the present study, a sideward lighting system was developed using diffusive optical fiber belts. More higher quality tissue-cultured transplants could be produced in a reduced space with the sideward lighting system than with a downward lighting system. An application of the sideward lighting system using diffusive optical fiber belts is described and the advantages and disadvantages are discussed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994ilce.work..325K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994ilce.work..325K"><span>Use of diffusive optical fibers for plant lighting</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kozai, T.; Kitaya, Y.; Fujiwara, K.; Kino, S.; Kinowaki, M.</p> <p>1994-03-01</p> <p>Lighting is one of the most critical aspects in plant production and environmental research with plants. Much research has been repeated on the effect of light intensity, spectral distribution of light and lighting cycle, but comparatively little research done on the effect of lighting direction on the growth, development and morphology of plants. When plants are grown with lamps above, light is directed downward to the plants. Downward or overhead lighting is utilized in almost all cases. However, downward lighting does not always give the best result in terms of lighting efficiency, growth, development and morphology of plants. In the present study, a sideward lighting system was developed using diffusive optical fiber belts. More higher quality tissue-cultured transplants could be produced in a reduced space with the sideward lighting system than with a downward lighting system. An application of the sideward lighting system using diffusive optical fiber belts is described and the advantages and disadvantages are discussed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2005/5052/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2005/5052/"><span>Hydrology and water quality of lakes and streams in Orange County, Florida</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>German, Edward R.; Adamski, James C.</p> <p>2005-01-01</p> <p>Orange County, Florida, is continuing to experience a large growth in population. In 1920, the population of Orange County was less than 20,000; in 2000, the population was about 896,000. The amount of urban area around Orlando has increased considerably, especially in the northwest part of the County. The eastern one-third of the County, however, had relatively little increase in urbanization from 1977-97. The increase of population, tourism, and industry in Orange County and nearby areas changed land use; land that was once agricultural has become urban, industrial, and major recreation areas. These changes could impact surface-water resources that are important for wildlife habitat, for esthetic reasons, and potentially for public supply. Streamflow characteristics and water quality could be affected in various ways. As a result of changing land use, changes in the hydrology and water quality of Orange County's lakes and streams could occur. Median runoff in 10 selected Orange County streams ranges from about 20 inches per year (in/yr) in the Wekiva River to about 1.1 in/yr in Cypress Creek. The runoff for the Wekiva River is significantly higher than other river basins because of the relatively constant spring discharge that sustains streamflow, even during drought conditions. The low runoff for the Cypress Creek basin results from a lack of sustained inflow from ground water and a relatively large area of lakes within the drainage basin. Streamflow characteristics for 13 stations were computed on an annual basis and examined for temporal trends. Results of the trend testing indicate changes in annual mean streamflow, 1-day high streamflow, or 7-day low streamflow at 8 of the 13 stations. However, changes in 7-day low streamflow are more common than changes in annual mean or 1-day high streamflow. There is probably no single reason for the changes in 7-day low streamflows, and for most streams, it is difficult to determine definite reasons for the flow increases. Low flows in the Econlockhatchee River at Chuluota have increased because of discharge of treated wastewater since 1982. However, trends in increasing 7-day low streamflow are evident before 1982, which cannot be attributed to wastewater discharge. Some of the increases in 7-day low flows may be related to drainage changes resulting from increased development in Orange County. Development for most purposes, including those as diverse as cattle grazing and residential construction, may involve modification of surface drainage through stream channelization and construction of canals. These changes in land drainage can lower the water table, resulting in reductions of regional evapotranspiration rates and increased streamflow. Another possible cause of increasing low flows in streams is use of water from the Floridan aquifer system for irrigation. Runoff of irrigation water or increased seepage from irrigated areas to streams could increase base streamflow compared to natural conditions. Water-level data were analyzed to determine temporal trends from 83 lakes that had more than 15 years of record. There were significant temporal trends in 33 of the 83 lakes (40 percent) over the entire period of record. Of these 33 lakes, 14 had increasing water levels and 19 lakes had decreasing water levels. The downward trends in long-term lake levels could in part be due to high rainfall accumulation in 1960-1961, which included precipitation from Hurricane Donna (September 1960). The high rainfall resulted in historical high-water levels in many lakes in 1960 or 1961. A large range of water-quality conditions exists in lakes and streams of Orange County (2000-01). Specific conductance in lake samples ranged from 57 to 1,185 microsiemens per centimeter. Values of pH ranged from 3.2 to 8.7 in stream samples and 4.6 to 9.6 in lake samples. Total nitrogen concentrations ranged from less than 0.2 to 7.1 milligrams per liter (mg/L) as nitrogen in stream samples, and</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/865602','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/865602"><span>Void/particulate detector</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Claytor, Thomas N.; Karplus, Henry B.</p> <p>1985-01-01</p> <p>Voids and particulates are detected in a flowing stream of fluid contained in a pipe by a detector which includes three transducers spaced about the pipe. A first transducer at a first location on the pipe transmits an ultrasonic signal into the stream. A second transducer detects the through-transmission of the signal at a second location and a third transducer at a third location upstream from the first location detects the back-scattering of the signal from any voids or particulates. To differentiate between voids and particulates a fourth transducer is positioned at a fourth location which is also upstream from the first location. The back-scattered signals are normalized with the through-transmission signal to minimize temperature fluctuations.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.H23K..07L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.H23K..07L"><span>Differentiating between anthropogenic and geological sources of nitrate using multiple geochemical tracers</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Linhoff, B.; Norton, S.; Travis, R.; Romero, Z.; Waters, B.</p> <p>2017-12-01</p> <p>Nitrate contamination of groundwater is a major problem globally including within the Albuquerque Basin in New Mexico. Ingesting high concentrations of nitrate (> 10 mg/L as N) can lead to an increased risk of cancer and to methemoglobinemia in infants. Numerous anthropogenic sources of nitrate have been identified within the Albuquerque Basin including fertilizers, landfills, multiple sewer pipe releases, sewer lagoons, domestic septic leach fields, and a nitric acid line outfall. Furthermore, groundwater near ephemeral streams often exhibits elevated NO3 concentrations and high NO3/Cl ratios incongruous with an anthropogenic source. These results suggest that NO3 can be concentrated through evaporation beneath ephemeral streams and mobilized via irrigation or land use change. This study seeks to use extensive geochemical analyses of groundwater and surface water to differentiate between various sources of NO3 contamination. The U.S. Geological Survey collected 54 groundwater samples from wells and six samples from ephemeral streams from within and from outside of areas of known nitrate contamination. To fingerprint the sources of nitrate pollution, samples were analyzed for major ions, trace metals, nutrients, dissolved gases, δ15N and δ18O in NO3, δ15N within N2 gas, and, δ2H and δ18O in H2O. Furthermore, most sites were sampled for artificial sweeteners and numerous contaminants of emerging concern including pharmaceutical drugs, caffeine, and wastewater indicators. This study will also investigate the age distribution of groundwater and the approximate age of anthropogenic NO3 contamination using 3He/4He, δ13C, 14C, 3H, as well as pharmaceutical drugs and artificial sweeteners with known patent and U.S. Food and Drug Administration approval dates. This broad suite of analytes will be used to differentiate between naturally occurring and multiple anthropogenic NO3 sources, and to potentially determine the approximate date of NO3 contamination.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003AGUFM.B21D0746S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AGUFM.B21D0746S"><span>Differentiating atmospheric and mineral sources of sulfur during snowmelt using δ 34S, 35S activity, and δ 18O of sulfate and water as tracers</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shanley, J. B.; Mayer, B.; Mitchell, M. J.; Michel, R. L.; Bailey, S.; Kendall, C.</p> <p>2003-12-01</p> <p>The biogeochemical cycling of sulfur was studied during the 2000 snowmelt at Sleepers River Research Watershed in northeastern Vermont, USA using a combination of isotopic, chemical, and hydrometric measurements. The snowpack and 10 streams of varying size and land use were sampled for sulfate concentrations and isotopic analyses of 35S, δ 34S, and δ 18O of sulfate. Values of δ 18O of water were measured at one of the streams. Apportionment of atmospheric and mineral S sources based on δ 34S was possible at 7 of the 10 streams. Weathering of S-containing minerals was a major contributor to sulfate flux in streamwater, but atmospheric contributions exceeded 50% in several of the streams at peak snowmelt and averaged 41% overall. In contrast, δ 18Osulfate values of streamwater remained significantly lower than those of atmospheric sulfate throughout the melt period, indicating that atmospheric sulfate undergoes microbial redox reactions in the soil that replace the oxygen of atmospheric sulfate with isotopically lighter oxygen from soil water. Streamwater 35S activities were low relative to those of the snowpack; the youngest 35S-ages of the atmospheric S component in each of the 7 streams ranged from 184 to 320 days. Atmospheric S contributions to streamwater, as determined by δ 34S values, co-varied both with 35S activity and new water contributions as determined by δ 18Owater. However, the δ 18Osulfate and 35S ages clearly show that this new water carries very little of the atmospheric sulfate entering with the current snowmelt to the stream. Most incoming atmospheric sulfate first cycles through the organic soil S pool and ultimately reaches the stream as pedogenic sulfate.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3901649','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3901649"><span>Segregation and Integration of Auditory Streams when Listening to Multi-Part Music</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ragert, Marie; Fairhurst, Merle T.; Keller, Peter E.</p> <p>2014-01-01</p> <p>In our daily lives, auditory stream segregation allows us to differentiate concurrent sound sources and to make sense of the scene we are experiencing. However, a combination of segregation and the concurrent integration of auditory streams is necessary in order to analyze the relationship between streams and thus perceive a coherent auditory scene. The present functional magnetic resonance imaging study investigates the relative role and neural underpinnings of these listening strategies in multi-part musical stimuli. We compare a real human performance of a piano duet and a synthetic stimulus of the same duet in a prioritized integrative attention paradigm that required the simultaneous segregation and integration of auditory streams. In so doing, we manipulate the degree to which the attended part of the duet led either structurally (attend melody vs. attend accompaniment) or temporally (asynchronies vs. no asynchronies between parts), and thus the relative contributions of integration and segregation used to make an assessment of the leader-follower relationship. We show that perceptually the relationship between parts is biased towards the conventional structural hierarchy in western music in which the melody generally dominates (leads) the accompaniment. Moreover, the assessment varies as a function of both cognitive load, as shown through difficulty ratings and the interaction of the temporal and the structural relationship factors. Neurally, we see that the temporal relationship between parts, as one important cue for stream segregation, revealed distinct neural activity in the planum temporale. By contrast, integration used when listening to both the temporally separated performance stimulus and the temporally fused synthetic stimulus resulted in activation of the intraparietal sulcus. These results support the hypothesis that the planum temporale and IPS are key structures underlying the mechanisms of segregation and integration of auditory streams, respectively. PMID:24475030</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24475030','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24475030"><span>Segregation and integration of auditory streams when listening to multi-part music.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ragert, Marie; Fairhurst, Merle T; Keller, Peter E</p> <p>2014-01-01</p> <p>In our daily lives, auditory stream segregation allows us to differentiate concurrent sound sources and to make sense of the scene we are experiencing. However, a combination of segregation and the concurrent integration of auditory streams is necessary in order to analyze the relationship between streams and thus perceive a coherent auditory scene. The present functional magnetic resonance imaging study investigates the relative role and neural underpinnings of these listening strategies in multi-part musical stimuli. We compare a real human performance of a piano duet and a synthetic stimulus of the same duet in a prioritized integrative attention paradigm that required the simultaneous segregation and integration of auditory streams. In so doing, we manipulate the degree to which the attended part of the duet led either structurally (attend melody vs. attend accompaniment) or temporally (asynchronies vs. no asynchronies between parts), and thus the relative contributions of integration and segregation used to make an assessment of the leader-follower relationship. We show that perceptually the relationship between parts is biased towards the conventional structural hierarchy in western music in which the melody generally dominates (leads) the accompaniment. Moreover, the assessment varies as a function of both cognitive load, as shown through difficulty ratings and the interaction of the temporal and the structural relationship factors. Neurally, we see that the temporal relationship between parts, as one important cue for stream segregation, revealed distinct neural activity in the planum temporale. By contrast, integration used when listening to both the temporally separated performance stimulus and the temporally fused synthetic stimulus resulted in activation of the intraparietal sulcus. These results support the hypothesis that the planum temporale and IPS are key structures underlying the mechanisms of segregation and integration of auditory streams, respectively.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930091495','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930091495"><span>Measurement of the Differential and Total Thrust and Torque of Six Full-Scale Adjustable-Pitch Propellers</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stickle, George W</p> <p>1933-01-01</p> <p>Force measurements giving total thrust and torque, and propeller slip stream surveys giving differential thrust and torque were simultaneously made on each of six full-scale propellers in the 20-foot propeller-research tunnel of the National Advisory Committee for Aeronautics. They were adjustable-pitch metal propellers 9.5 feet in diameter; three had modified Clark Y blade sections and three had modified RAF-6 blade sections. This report gives the differential thrust and torque and the variation caused by changing the propeller tip speed and the pitch setting. The total thrust and torque obtained from integration of the thrust and torque distribution curves are compared with those obtained by direct force measurements.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27833119','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27833119"><span>Streaming current magnetic fields in a charged nanopore.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mansouri, Abraham; Taheri, Peyman; Kostiuk, Larry W</p> <p>2016-11-11</p> <p>Magnetic fields induced by currents created in pressure driven flows inside a solid-state charged nanopore were modeled by numerically solving a system of steady state continuum partial differential equations, i.e., Poisson, Nernst-Planck, Ampere and Navier-Stokes equations (PNPANS). This analysis was based on non-dimensional transport governing equations that were scaled using Debye length as the characteristic length scale, and applied to a finite length cylindrical nano-channel. The comparison of numerical and analytical studies shows an excellent agreement and verified the magnetic fields density both inside and outside the nanopore. The radially non-uniform currents resulted in highly non-uniform magnetic fields within the nanopore that decay as 1/r outside the nanopore. It is worth noting that for either streaming currents or streaming potential cases, the maximum magnetic field occurred inside the pore in the vicinity of nanopore wall, as opposed to a cylindrical conductor that carries a steady electric current where the maximum magnetic fields occur at the perimeter of conductor. Based on these results, it is suggested and envisaged that non-invasive external magnetic fields readouts generated by streaming/ionic currents may be viewed as secondary electronic signatures of biomolecules to complement and enhance current DNA nanopore sequencing techniques.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70197038','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70197038"><span>Hydrologic regimes as potential drivers of morphologic divergence in fish</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Bruckerhoff, Lindsey; Magoulick, Daniel D.</p> <p>2017-01-01</p> <p>Fishes often exhibit phenotypic divergence across gradients of abiotic and biotic selective pressures. In streams, many of the known selective pressures driving phenotypic differentiation are largely influenced by hydrologic regimes. Because flow regimes drive so many attributes of lotic systems, we hypothesized fish exhibit phenotypic divergence among streams with different flow regimes. We used a comparative field study to investigate the morphological divergence of Campostoma anomalom (central stonerollers) among streams characterized by highly variable, intermittent flow regimes and streams characterized by relatively stable, groundwater flow regimes. We also conducted a mesocosm experiment to compare the plastic effects of one component of flow regimes, water velocity, on morphology of fish from different flow regimes. We observed differences in shape between flow regimes likely driven by differences in allometric growth patterns. Although we observed differences in morphology across flow regimes in the field, C. anomalum did not exhibit morphologic plasticity in response to water velocity alone. This study contributes to the understanding of how complex environmental factors drive phenotypic divergence and may provide insight into the evolutionary consequences of disrupting natural hydrologic patterns, which are increasingly threatened by climate change and anthropogenic alterations.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JHyd..555..323D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JHyd..555..323D"><span>Developing semi-analytical solution for multiple-zone transient storage model with spatially non-uniform storage</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Deng, Baoqing; Si, Yinbing; Wang, Jia</p> <p>2017-12-01</p> <p>Transient storages may vary along the stream due to stream hydraulic conditions and the characteristics of storage. Analytical solutions of transient storage models in literature didn't cover the spatially non-uniform storage. A novel integral transform strategy is presented that simultaneously performs integral transforms to the concentrations in the stream and in storage zones by using the single set of eigenfunctions derived from the advection-diffusion equation of the stream. The semi-analytical solution of the multiple-zone transient storage model with the spatially non-uniform storage is obtained by applying the generalized integral transform technique to all partial differential equations in the multiple-zone transient storage model. The derived semi-analytical solution is validated against the field data in literature. Good agreement between the computed data and the field data is obtained. Some illustrative examples are formulated to demonstrate the applications of the present solution. It is shown that solute transport can be greatly affected by the variation of mass exchange coefficient and the ratio of cross-sectional areas. When the ratio of cross-sectional areas is big or the mass exchange coefficient is small, more reaches are recommended to calibrate the parameter.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatSR...636771M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatSR...636771M"><span>Streaming current magnetic fields in a charged nanopore</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mansouri, Abraham; Taheri, Peyman; Kostiuk, Larry W.</p> <p>2016-11-01</p> <p>Magnetic fields induced by currents created in pressure driven flows inside a solid-state charged nanopore were modeled by numerically solving a system of steady state continuum partial differential equations, i.e., Poisson, Nernst-Planck, Ampere and Navier-Stokes equations (PNPANS). This analysis was based on non-dimensional transport governing equations that were scaled using Debye length as the characteristic length scale, and applied to a finite length cylindrical nano-channel. The comparison of numerical and analytical studies shows an excellent agreement and verified the magnetic fields density both inside and outside the nanopore. The radially non-uniform currents resulted in highly non-uniform magnetic fields within the nanopore that decay as 1/r outside the nanopore. It is worth noting that for either streaming currents or streaming potential cases, the maximum magnetic field occurred inside the pore in the vicinity of nanopore wall, as opposed to a cylindrical conductor that carries a steady electric current where the maximum magnetic fields occur at the perimeter of conductor. Based on these results, it is suggested and envisaged that non-invasive external magnetic fields readouts generated by streaming/ionic currents may be viewed as secondary electronic signatures of biomolecules to complement and enhance current DNA nanopore sequencing techniques.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4241827','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4241827"><span>The influence of human settlement on the distribution and diversity of iron-oxidizing bacteria belonging to the Gallionellaceae in tropical streams</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Reis, Mariana P.; Ávila, Marcelo P.; Costa, Patrícia S.; Barbosa, Francisco A. R.; Laanbroek, Hendrikus J.; Chartone-Souza, Edmar; Nascimento, Andréa M. A.</p> <p>2014-01-01</p> <p>Among the neutrophilic iron-oxidizing bacteria (FeOB), Gallionella is one of the most abundant genera in freshwater environments. By applying qPCR and DGGE based on 16S rRNA gene-directed primers targeting Gallionellaceae, we delineated the composition and abundance of the Gallionellaceae-related FeOB community in streams differentially affected by metal mining, and explored the relationships between these community characteristics and environmental variables. The sampling design included streams historically impacted by mining activity and a non-impacted stream. The sediment and water samples harbored a distinct community represented by Gallionella, Sideroxydans, and Thiobacillus species. Sequences affiliated with Gallionella were exclusively observed in sediments impacted by mining activities, suggesting an adaptation of this genus to these environments. In contrast, Sideroxydans-related sequences were found in all sediments including the mining impacted locations. The highest and lowest relative frequencies of Gallionellaceae-related FeOB were associated with the lowest and highest concentrations of Fe, respectively. The data enclosed here clearly show distinct species-specific ecological niches, with Gallionella species dominating in sediments impacted by anthropogenic activities over Sideroxydans species. PMID:25505456</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999DSRII..46.2669T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999DSRII..46.2669T"><span>The downward flux of biogenic material in the NE subarctic Pacific: importance of algal sinking and mesozooplankton herbivory</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thibault, D.; Roy, S.; Wong, C. S.; Bishop, J. K.</p> <p>1999-11-01</p> <p>In the present study we examine factors that affect the downward flux of biogenic carbon in the NE subarctic Pacific, one of the important high-nutrient-low-chlorophyll (HNLC) regions in the open ocean. We focus on the role of mesozooplankton, since their seasonal peaks in biomass and growth are in phase with the seasonal variations in the downward POC fluxes, whereas phytoplankton biomass is more-or-less uniform year-round. The relative importance of mesozooplankton and algal sinking was examined using the pigment composition of material accumulated in short-term free-drifting sediment traps positioned just below the upper stratified surface layer (ca. 100-200 m). This was compared with the phytoplankton composition in the surface waters, and with the grazing activity (gut pigments and fecal pellet production rates) of the most abundant large copepods. We also examined whether the relationships between the downward flux of carbon and pelagic processes were similar in the coastal, continental margin and offshore HNLC regions of the NE subarctic Pacific, the latter represented by Ocean Station Papa (OSP). Our results show that grazing had a variable impact on the downward flux of biogenic carbon. Carbon-transformed pheopigments (particularly pyropheophorbide a, frequently associated with copepod grazing) represented up to 13% of the total downward POC flux inshore (in May 1996) and 8-9% at OSP in May and February 1996, respectively. This flux of pheopigments was accompanied by a large potential input of fecal pellets from large copepods (as estimated from defecation rates of freshly collected animals) only in May 1996 at OSP, suggesting that pheopigments came from other sources (other herbivores, senescing algae) in February. The larger flux of pheopigments in May was probably related to the abundance of mesozooplankton at that time of the year. During summer (August 1996), both the flux of pheopigments and the potential input of fecal pellets from large copepods were negligible at OSP, consistent with more intense pelagic recycling reported in other studies. Inshore, the flux of carbon-transformed pheopigments was slightly higher than at OSP, and its contribution to the downward POC flux in May 1996 was twice that in August 1996. In contrast, the potential input of feces carbon was higher in August than in May 1996, again suggesting other sources for pheopigments found in the traps. The contribution of sinking phytoplankton to the downward biogenic flux was negligible in summer, when prymnesiophytes (indicated by the presence of 19'-hexanoyloxyfucoxanthin) and pelagophytes (19'-butanoyloxyfucoxanthin-containing) dominated in surface offshore waters. The contribution of sinking algae was maximal (9%) in winter (February 1996) at OSP, when fucoxanthin (mainly a diatom marker) dominated the carotenoid composition in the traps and when the abundance of diatoms in surface waters showed its seasonal maximum for this station. Inshore, the low contribution of diatoms (fucoxanthin) to the sinking fluxes may have resulted from inadequate sampling (i.e. the spring bloom may have been missed). Overall, we conclude that: (a) large copepods significantly influenced the downward POC flux only during spring at OSP; (b) unidentified herbivores (e.g. salps, pteropods) producing pigmented, fast-sinking fecal material likely had an important impact during winter; (c) algal sinking made a small contribution to the downward POC flux (maximum in winter); and (d) neither algal sinking nor mesozooplankton grazing had a significant influence on the downward flux of biogenic material in summer at OSP.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApJ...832...94K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApJ...832...94K"><span>Babcock-Leighton Solar Dynamo: The Role of Downward Pumping and the Equatorward Propagation of Activity</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Karak, Bidya Binay; Cameron, Robert</p> <p>2016-11-01</p> <p>The key elements of the Babcock-Leighton dynamos are the generation of poloidal field through decay and the dispersal of tilted bipolar active regions and the generation of toroidal field through the observed differential rotation. These models are traditionally known as flux transport dynamo models as the equatorward propagations of the butterfly wings in these models are produced due to an equatorward flow at the bottom of the convection zone. Here we investigate the role of downward magnetic pumping near the surface using a kinematic Babcock-Leighton model. We find that the pumping causes the poloidal field to become predominately radial in the near-surface shear layer, which allows the negative radial shear to effectively act on the radial field to produce a toroidal field. We observe a clear equatorward migration of the toroidal field at low latitudes as a consequence of the dynamo wave even when there is no meridional flow in the deep convection zone. Both the dynamo wave and the flux transport type solutions are thus able to reproduce some of the observed features of the solar cycle including the 11-year periodicity. The main difference between the two types of solutions is the strength of the Babcock-Leighton source required to produce the dynamo action. A second consequence of the magnetic pumping is that it suppresses the diffusion of fields through the surface, which helps to allow an 11-year cycle at (moderately) larger values of magnetic diffusivity than have previously been used.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040090226&hterms=Zea+Mays&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DZea%2BMays%2BL.','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040090226&hterms=Zea+Mays&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DZea%2BMays%2BL."><span>Correlations between gravitropic curvature and auxin movement across gravistimulated roots of Zea mays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Young, L. M.; Evans, M. L.; Hertel, R.</p> <p>1990-01-01</p> <p>We compared the kinetics of auxin redistribution across the caps of primary roots of 2-day-old maize (Zea mays, cv Merit) seedlings with the time course of gravitropic curvature. [3H] indoleacetic acid was applied to one side of the cap in an agar donor and radioactivity moving across the cap was collected in an agar receiver applied to the opposite side. Upon gravistimulation the roots first curved upward slightly, then returned to the horizontal and began curving downward, reaching a final angle of about 67 degrees. Movement of label across the caps of gravistimulated roots was asymmetric with preferential downward movement (ratio downward/upward = ca. 1.6, radioactivity collected during the 90 min following beginning of gravistimulation). There was a close correlation between the development of asymmetric auxin movement across the root cap and the rate of curvature, with both values increasing to a maximum and then declining as the roots approached the final angle of curvature. In roots preadapted to gravity (alternate brief stimulation on opposite flanks over a period of 1 hour) the initial phase of upward curvature was eliminated and downward bending began earlier than for controls. The correlation between asymmetric auxin movement and the kinetics of curvature also held in comparisons between control and preadapted roots. Both downward auxin transport asymmetry and downward curvature occurred earlier in preadapted roots than in controls. These findings are consistent with suggestions that the root cap is not only the site of perception but also the location of the initial redistribution of effectors that ultimately leads to curvature.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20010111087','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20010111087"><span>Numerical Study of Buoyancy and Different Diffusion Effects on the Structure and Dynamics of Triple Flames</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chen, Jyh-Yuan; Echekki, Tarek</p> <p>2001-01-01</p> <p>Numerical simulations of 2-D triple flames under gravity force have been implemented to identify the effects of gravity on triple flame structure and propagation properties and to understand the mechanisms of instabilities resulting from both heat release and buoyancy effects. A wide range of gravity conditions, heat release, and mixing widths for a scalar mixing layer are computed for downward-propagating (in the same direction with the gravity vector) and upward-propagating (in the opposite direction of the gravity vector) triple flames. Results of numerical simulations show that gravity strongly affects the triple flame speed through its contribution to the overall flow field. A simple analytical model for the triple flame speed, which accounts for both buoyancy and heat release, is developed. Comparisons of the proposed model with the numerical results for a wide range of gravity, heat release and mixing width conditions, yield very good agreement. The analysis shows that under neutral diffusion, downward propagation reduces the triple flame speed, while upward propagation enhances it. For the former condition, a critical Froude number may be evaluated, which corresponds to a vanishing triple flame speed. Downward-propagating triple flames at relatively strong gravity effects have exhibited instabilities. These instabilities are generated without any artificial forcing of the flow. Instead disturbances are initiated by minute round-off errors in the numerical simulations, and subsequently amplified by instabilities. A linear stability analysis on mean profiles of stable triple flame configurations have been performed to identify the most amplified frequency in spatially developed flows. The eigenfunction equations obtained from the linearized disturbance equations are solved using the shooting method. The linear stability analysis yields reasonably good agreements with the observed frequencies of the unstable triple flames. The frequencies and amplitudes of disturbances increase with the magnitude of the gravity vector. Moreover, disturbances appear to be most amplified just downstream of the premixed branches. The effects of mixing width and differential diffusion are investigated and their roles on the flame stability are studied.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24116840','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24116840"><span>Opposing dorsal/ventral stream dynamics during figure-ground segregation.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wokke, Martijn E; Scholte, H Steven; Lamme, Victor A F</p> <p>2014-02-01</p> <p>The visual system has been commonly subdivided into two segregated visual processing streams: The dorsal pathway processes mainly spatial information, and the ventral pathway specializes in object perception. Recent findings, however, indicate that different forms of interaction (cross-talk) exist between the dorsal and the ventral stream. Here, we used TMS and concurrent EEG recordings to explore these interactions between the dorsal and ventral stream during figure-ground segregation. In two separate experiments, we used repetitive TMS and single-pulse TMS to disrupt processing in the dorsal (V5/HMT⁺) and the ventral (lateral occipital area) stream during a motion-defined figure discrimination task. We presented stimuli that made it possible to differentiate between relatively low-level (figure boundary detection) from higher-level (surface segregation) processing steps during figure-ground segregation. Results show that disruption of V5/HMT⁺ impaired performance related to surface segregation; this effect was mainly found when V5/HMT⁺ was perturbed in an early time window (100 msec) after stimulus presentation. Surprisingly, disruption of the lateral occipital area resulted in increased performance scores and enhanced neural correlates of surface segregation. This facilitatory effect was also mainly found in an early time window (100 msec) after stimulus presentation. These results suggest a "push-pull" interaction in which dorsal and ventral extrastriate areas are being recruited or inhibited depending on stimulus category and task demands.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4203295','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4203295"><span>Is isolation by adaptation driving genetic divergence among proximate Dolly Varden char populations?</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bond, Morgan H; Crane, Penelope A; Larson, Wesley A; Quinn, Tom P</p> <p>2014-01-01</p> <p>Numerous studies of population genetics in salmonids and other anadromous fishes have revealed that population structure is generally organized into geographic hierarchies (isolation by distance), but significant structure can exist in proximate populations due to varying selective pressures (isolation by adaptation). In Chignik Lakes, Alaska, anadromous Dolly Varden char (Salvelinus malma) spawn in nearly all accessible streams throughout the watershed, including those draining directly to an estuary, Chignik Lagoon, into larger rivers, and into lakes. Collections of Dolly Varden fry from 13 streams throughout the system revealed low levels of population structure among streams emptying into freshwater. However, much stronger genetic differentiation was detected between streams emptying into freshwater and streams flowing directly into estuarine environments. This fine-scale reproductive isolation without any physical barriers to migration is likely driven by differences in selection pressures across freshwater and estuarine environments. Estuary tributaries had fewer larger, older juveniles, suggesting an alternative life history of smolting and migration to the marine environment at a much smaller size than occurs in the other populations. Therefore, genetic data were consistent with a scenario where isolation by adaptation occurs between populations of Dolly Varden in the study system, and ecological data suggest that this isolation may partially be a result of a novel Dolly Varden life history of seawater tolerance at a smaller size than previously recognized. PMID:25360283</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996SPIE.2803...64T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996SPIE.2803...64T"><span>Descent imager/spectral radiometer (DISR) instrument aboard the Huygens probe of Titan</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tomasko, Martin G.; Doose, Lyn R.; Smith, Peter H.; Fellows, C.; Rizk, B.; See, C.; Bushroe, M.; McFarlane, E.; Wegryn, E.; Frans, E.; Clark, R.; Prout, M.; Clapp, S.</p> <p>1996-10-01</p> <p>The Huygen's probe of the atmosphere of Saturn's moon Titan includes one optical instrument sensitive to the wavelengths of solar radiation. The goals of this investigation fall into four broad areas: 1) the measurement of the profile of solar heating to support an improved understanding of the thermal balance of Titan and the role of the greenhouse effect in maintaining Titan's temperature structure; 2) the measurement of the size, vertical distribution, and optical properties of the aerosol and cloud particles in Titan's atmosphere to support studies of the origin, chemistry, life cycles, and role in the radiation balance of Titan played by these particles; 3) the composition of the atmosphere, particularly the vertical profile of the mixing ratio of methane, a condensable constituent in Titan's atmosphere; and 4) the physical state, composition, topography, and physical processes at work in determining the nature of the surface of Titan and its interaction with Titan's atmosphere. In order to accomplish these objectives, the Descent Imager/Spectral Radiometer (DISR) instrument makes extensive use of fiber optics to bring the light from several different sets of foreoptics to a silicon CCD detector, to a pair of InGaAs linear array detectors, and to three silicon photometers. Together these detectors permit DISR to make panoramic images of the clouds and surface of Titan, to measure the spectrum of upward and downward streaming sunlight from 350 to 1700 nm at a resolving power of about 200, to measure the reflection spectrum of >= 3000 locations on the surface, to measure the brightness and polarization of the solar aureole between 4 and 30 degrees from the sun at 500 and 935 nm, to separate the direct and diffuse downward solar flux at each wavelength measured, and to measure the continuous reflection spectrum of the ground between 850 and 1600 nm using an onboard lamp in the last 100 m of the descent.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17834588','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17834588"><span>Recruitment in a sea anemone population: juvenile substrate becomes adult prey.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sebens, K P</p> <p>1981-08-14</p> <p>Populations of the sea anemone Anthopleura xanthogrammica (Brandt) occur in tide pools and surge channels below intertidal mussel beds where they capture mussels dislodged by wave action and by sea star foraging. Dense concentrations of small juvenile anemones occur only within mussel beds and are probably the result of larval settlement or differential survival in that habitat. Areas experimentally cleared of anemones showed that recruitment was primarily by migrating juveniles and that the rate of immigration over a 2-year period was much higher in experimental removal areas near mussel beds than in those further away. Mussel beds thus function as an important juvenile habitat (refuge and nursery); juveniles later migrate downward and are then in a position to capture dislodged mussels and grow to adult size.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/874142','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/874142"><span>Gravity brake</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Lujan, Richard E.</p> <p>2001-01-01</p> <p>A mechanical gravity brake that prevents hoisted loads within a shaft from free-falling when a loss of hoisting force occurs. A loss of hoist lifting force may occur in a number of situations, for example if a hoist cable were to break, the brakes were to fail on a winch, or the hoist mechanism itself were to fail. Under normal hoisting conditions, the gravity brake of the invention is subject to an upward lifting force from the hoist and a downward pulling force from a suspended load. If the lifting force should suddenly cease, the loss of differential forces on the gravity brake in free-fall is translated to extend a set of brakes against the walls of the shaft to stop the free fall descent of the gravity brake and attached load.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27133773','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27133773"><span>Scombroid Poisoning: A Practical Approach.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Guergué-Díaz de Cerio, O; Barrutia-Borque, A; Gardeazabal-García, J</p> <p>2016-09-01</p> <p>Scombroid poisoning is a common cause of food poisoning worldwide. It is caused by ingestion of oily fish contaminated with bacteria that trigger the formation of high concentrations of histamine. Scombroid poisoning manifests mainly as a skin complaint (flushing that spreads downward and/or an erythematous urticarial rash affecting the face and upper trunk). Although the clinical course is usually self-limiting and benign, vascular compromise, bronchospasm, and arrhythmias have been described. It is important to establish a differential diagnosis that includes conditions such as fish allergy. Oral antihistamines are the mainstay of treatment. Scombroid poisoning is best prevented by refrigerating fish properly. The practical review of scombroid poisoning provided here is intended for dermatologists. Copyright © 2016 AEDV. Publicado por Elsevier España, S.L.U. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17572748','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17572748"><span>Pressure measurement in supersonic air flow by differential absorptive laser-induced thermal acoustics.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hart, Roger C; Herring, G C; Balla, R Jeffrey</p> <p>2007-06-15</p> <p>Nonintrusive, off-body flow barometry in Mach 2 airflow has been demonstrated in a large-scale supersonic wind tunnel using seedless laser-induced thermal acoustics (LITA). The static pressure of the gas flow is determined with a novel differential absorption measurement of the ultrasonic sound produced by the LITA pump process. Simultaneously, the streamwise velocity and static gas temperature of the same spatially resolved sample volume were measured with this nonresonant time-averaged LITA technique. Mach number, temperature, and pressure have 0.2%, 0.4%, and 4% rms agreement, respectively, in comparison with known free-stream conditions.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2012/5193/pdf/sir2012-5193.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2012/5193/pdf/sir2012-5193.pdf"><span>Analysis of trends in selected streamflow statistics for the Concho River Basin, Texas, 1916-2009</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Barbie, Dana L.; Wehmeyer, Loren L.; May, Jayne E.</p> <p>2012-01-01</p> <p>Six U.S. Geological Survey streamflow-gaging stations were selected for analysis. Streamflow-gaging station 08128000 South Concho River at Christoval has downward trends for annual maximum daily discharge and annual instantaneous peak discharge for the combined period 1931-95, 2002-9. Streamflow-gaging station 08128400 Middle Concho River above Tankersley has downward trends for annual maximum daily discharge and annual instantaneous peak discharge for the combined period 1962-95, 2002-9. Streamflow-gaging station 08128500 Middle Concho River near Tankersley has no significant trends in the streamflow statistics considered for the period 1931-60. Streamflow-gaging station 08134000 North Concho River near Carlsbad has downward trends for annual mean daily discharge, annual 7-day minimum daily discharge, annual maximum daily discharge, and annual instantaneous peak discharge for the period 1925-2009. Streamflow-gaging stations 08136000 Concho River at San Angelo and 08136500 Concho River at Paint Rock have downward trends for 1916-2009 for all streamflow statistics calculated, but streamflow-gaging station 08136000 Concho River at San Angelo has an upward trend for annual maximum daily discharge during 1964-2009. The downward trends detected during 1916-2009 for the Concho River at San Angelo are not unexpected because of three reservoirs impounding and profoundly regulating streamflow.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMAE12A..02Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMAE12A..02Q"><span>Positive recoil leader in rocket-triggered and tower-initiated lightning flashes as observed by high speed video camera</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Qie, X.; Pu, Y.; Jiang, R.; Liu, M.; Sun, Z.</p> <p>2017-12-01</p> <p>Positive recoil leader was observed in both rocket-triggered and tower lightning flashes. The similar processes are observed in all the cases: an initial weakening dart leader propagated downward from the cloud with weak luminosity and terminated finally before reaching the ground. Then the bidirectional leaders started and propagated in the preexisting and decaying channel below the terminated downward dart leader, and the luminosity of the bileader ends was asymmetrical, but both with its tip being the weakest. The upward positive leader end started earlier and fast than the downward negative leader end. The bidirectional leader developed with the positive leader moving upward, along the decayed downward negative leader channel, and the negative leader downward, along the remnants of the channel created by the previous stroke or ICC, and, hence, could be viewed as a kind of recoil leader. However, the polarity of this recoil leader is contrary to the traditional recoil leader with negative leader end retrogressing along an existing positive leader channel. The bidirectional leaders observed herein are new as they are excited by a decayed negative leader with in the preexisting discharge channel, unlike other bidirectional leaders, e.g., the electric breakdown in virgin air or traditional recoil processes formed in a decayed positive leader channel.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://eric.ed.gov/?q=Differentiation+AND+leadership&pg=3&id=EJ992147','ERIC'); return false;" href="https://eric.ed.gov/?q=Differentiation+AND+leadership&pg=3&id=EJ992147"><span>Engaging Staff Communities in a Knowledge Transfer Strategy: A Case Study at the University of Melbourne</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Goodwill, Robyn J.</p> <p>2012-01-01</p> <p>Within the framework of the strategic journey undertaken between 2005 and 2010, this paper seeks to examine how the University of Melbourne sought to differentiate itself through the introduction and reconceptualisation of a "third stream" of academic work. Specifically, this paper seeks to investigate, through qualitative methods, how…</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/41733','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/41733"><span>Diversity and stability in Mississippi stream fish assemblages</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Jocob F. Schaefer; Scott R. Clark; Melvin L. Jr. Warren</p> <p>2012-01-01</p> <p>Positive correlations between diversity and stability have been reported for a number of ecosystems and are thought to be caused by a stabilizing effect of differential speciesâ responses to environmental perturbation. Empirical field studies in which investigators tested for diversityâstability relationships are lacking for some taxonomic groups and typically have not...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://eric.ed.gov/?q=elitism&pg=6&id=EJ840586','ERIC'); return false;" href="https://eric.ed.gov/?q=elitism&pg=6&id=EJ840586"><span>Allowing Idiosyncratic Learners to Thrive: Policy Implications of a Study of School-within-a-School Gifted Programs</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Matthews, Dona; Kitchen, Julian</p> <p>2007-01-01</p> <p>School-within-a-school programs are an alternative school choice that can provide differentiated learning opportunities for academically gifted students, but they are often politically contentious. In a recent study, we interviewed 530 students and teachers in gifted and regular streams in three publicly funded secondary schools with different…</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED029980.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED029980.pdf"><span>A Benefit Cost Analysis of the South Carolina MDTA Program. Preliminary Report.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>South Carolina Univ., Columbia. Bureau of Business and Economic Research.</p> <p></p> <p>Manpower Development and Training Act (MDTA) programs completed in 1965 were evaluated by benefit-cost ratio and internal rate of return. Initial annual earnings differential figures at $525,650 and $719,629 were projected into the future at various rates of promotion and various rates of discount on the benefit stream. Resulting lifetime benefits…</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1175734','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/1175734"><span>Enhanced selectivity of zeolites by controlled carbon deposition</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Nenoff, Tina M.; Thoma, Steven G.; Kartin, Mutlu</p> <p>2006-05-09</p> <p>A method for carbonizing a zeolite comprises depositing a carbon coating on the zeolite pores by flowing an inert carrier gas stream containing isoprene through a regenerated zeolite at elevated temperature. The carbonized zeolite is useful for the separation of light hydrocarbon mixtures due to size exclusion and the differential adsorption properties of the carbonized zeolite.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA522251','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA522251"><span>A Framework and Strategies for Determining Reference Conditions for Streams with Legacy Sediments on Military Installations</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2009-03-01</p> <p>water where there is a sharp change in channel slope, such as a waterfall or lake, resulting from differential rates of erosion above and below the...Beitrage zur Lehre von der biologische Gewasserbeurteilung. International Review of Hydrobiology 2:126-52. ———. 1909. Oekologie der Saprobien. Uber</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.H43D1475V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.H43D1475V"><span>Understanding Groundwater and Surface Water Exchange Processes Along a Controlled Stream Using Thermal Remote Sensing and In-Situ Measurements</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Varli, D.; Yilmaz, K. K.</p> <p>2016-12-01</p> <p>Effective management of water resources requires understanding and quantification of interaction between groundwater and surface water bodies. Moreover, the exchange processes have recently received increasing attention due to important influences on biogeochemical and ecological status of watersheds. In this study we investigated the exchange processes between surface water and groundwater along Kirmir stream - a controlled stream nearby Kizilcahamam, Ankara, Turkey. At the first stage, potential stream reaches where the exchange processes could occur were pinpointed using geological and geomorphological information. Then, thermal remote sensing was utilized to further narrow down the potential locations in which interaction could occur at a smaller scale. Nested piezometers were installed at identified locations to observe the variations in vertical hydraulic gradient over time. Differential discharge measurements were performed to understand the gains and losses along the stream reach. Streambed temperature measurements were taken at two different depths for a period of time using temperature loggers to calculate the vertical fluid fluxes through the streambed at various locations. Basic water quality field parameters (temperature, electrical conductivity, total dissolved solid amount, dissolved oxygen, pH and oxidation - reduction potential) were measured along the stream reach, from surface water and the piezometers as wells as from the nearby springs and wells. Chloride mass balance was performed to find the contribution of groundwater and chloride concentrations were associated with the geology of the area. This hierarchical, multi-scale methodology provided an efficient and effective way to determine the locations and the direction of groundwater and surface water exchange processes within the study area.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24815045','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24815045"><span>Face and location processing in children with early unilateral brain injury.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Paul, Brianna; Appelbaum, Mark; Carapetian, Stephanie; Hesselink, John; Nass, Ruth; Trauner, Doris; Stiles, Joan</p> <p>2014-07-01</p> <p>Human visuospatial functions are commonly divided into those dependent on the ventral visual stream (ventral occipitotemporal regions), which allows for processing the 'what' of an object, and the dorsal visual stream (dorsal occipitoparietal regions), which allows for processing 'where' an object is in space. Information about the development of each of the two streams has been accumulating, but very little is known about the effects of injury, particularly very early injury, on this developmental process. Using a set of computerized dorsal and ventral stream tasks matched for stimuli, required response, and difficulty (for typically-developing individuals), we sought to compare the differential effects of injury to the two systems by examining performance in individuals with perinatal brain injury (PBI), who present with selective deficits in visuospatial processing from a young age. Thirty participants (mean=15.1 years) with early unilateral brain injury (15 right hemisphere PBI, 15 left hemisphere PBI) and 16 matched controls participated. On our tasks children with PBI performed more poorly than controls (lower accuracy and longer response times), and this was particularly prominent for the ventral stream task. Lateralization of PBI was also a factor, as the dorsal stream task did not seem to be associated with lateralized deficits, with both PBI groups showing only subtle decrements in performance, while the ventral stream task elicited deficits from RPBI children that do not appear to improve with age. Our findings suggest that early injury results in lesion-specific visuospatial deficits that persist into adolescence. Further, as the stimuli used in our ventral stream task were faces, our findings are consistent with what is known about the neural systems for face processing, namely, that they are established relatively early, follow a comparatively rapid developmental trajectory (conferring a vulnerability to early insult), and are biased toward the right hemisphere. Copyright © 2014 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.H11M..06S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.H11M..06S"><span>Impacts of Past Land Use Changes on Water Resources: An Analog for Assessing Effects of Proposed Bioenergy Crops</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Scanlon, B. R.; Schilling, K.; Young, M.; Duncan, I. J.; Gerbens-Leenes, P.</p> <p>2011-12-01</p> <p>Interest is increasing in renewable energy sources, including bioenergy. However, potential impacts of bioenergy crops on water resources need to be better understood before large scale expansion occurs. This study evaluates the potential for using past land use change impacts on water resources as an analog for assessing future bioenergy crop effects. Impacts were assessed for two cases and methods: (1) changes from perennial to annual crops in the Midwest U.S. using stream hydrograph separation; and (2) changes from perennial grasses and shrubs to annual crops in the Southwest U.S. using unsaturated zone and groundwater data. Results from the Midwest show that expanding the soybean production area by 80,000 km2 increased stream flow by 32%, based on data from Keokuk station in the Upper Mississippi River Basin. Using these relationships, further expansion of annual corn production for biofuels by 10 - 50% would increase streamflow by up to 40%, with related increases in nitrate, phosphate, and sediment pollutant transport to the Gulf of Mexico. The changes in water partitioning are attributed to reducing evapotranspiration, increasing recharge and baseflow discharge to streams. Similar results were found in the southwestern US, where changes from native perennial grasses and shrubs to annual crops increased recharge from ~0.0 to 24 mm/yr, raising water tables by up to 7 m in some regions and flushing accumulated salts into underlying aquifers in the southern High Plains. The changes in water partitioning are related to changes in rooting depth from deep rooted native vegetation to shallow rooted crops and growing season length. Further expansion of annual bioenergy crops, such as changes from Conservation Reserve Program to corn in the Midwest, will continue the trajectory of reducing ET, thereby increasing recharge and baseflow to streams and nutrient export. We hypothesize that changing bioenergy crops from annual crops to perennial grasses, such as switchgrass and Miscanthus, will reverse these changes in water partitioning, increasing ET, and decreasing recharge, baseflow and nutrient transport to streams. These changes occur primarily because of the deeper roots and longer growing season of the grasses, capturing water percolating downward. These projected changes in water resources are supported by high water footprints for perennial grasses relative to annual crops globally. While reducing pollution from nutrient loading is an obvious benefit, reducing recharge may have negative ramifications for groundwater and surface water resources. Our research shows that there are water quantity and quality consequences of cultivating various bioenergy crops that should be considered before large scale expansion occurs. Data from past land use changes provide valuable information that can be used as a guide to evaluate potential impacts of future land use changes related to bioenergy crops.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/sir/2010/5078/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/sir/2010/5078/"><span>Surface-Water Quality Conditions and Long-Term Trends at Selected Sites within the Ambient Water-Quality Monitoring Network in Missouri, Water Years 1993-2008</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Barr, Miya N.; Davis, Jerri V.</p> <p>2010-01-01</p> <p>The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, collects data pertaining to the surface-water resources of Missouri. These data are collected as part of the Missouri Ambient Water-Quality Monitoring Network and constitute a valuable source of reliable, impartial, and timely information for developing an improved understanding of water resources in the State. Six sites from the Ambient Water-Quality Monitoring Network, with data available from the 1993 through 2008 water years, were chosen to compare water-quality conditions and long-term trends of dissolved oxygen, selected physical properties, total suspended solids, dissolved nitrate plus nitrite as nitrogen, total phosphorous, fecal indicator bacteria, and selected trace elements. The six sites used in the study were classified in groups corresponding to the physiography, main land use, and drainage basin size, and represent most stream types in Missouri. Long-term trends in this study were analyzed using flow-adjusted and non-flow adjusted models. Highly censored datasets (greater than 5 percent but less than 50 percent censored values) were not flow-adjusted. Trends that were detected can possibly be related to changes in agriculture or urban development within the drainage basins. Trends in nutrients were the most prevalent. Upward flow-adjusted trends in dissolved nitrate plus nitrite (as nitrogen) concentrations were identified at the Elk River site, and in total phosphorus concentrations at the South Fabius and Grand River sites. A downward flow-adjusted trend was identified in total phosphorus concentrations from Wilson Creek, the only urban site in the study. The downward trend in phosphorus possibly was related to a phosphorus reduction system that began operation in 2001 at a wastewater treatment plant upstream from the sampling site. Total suspended solids concentrations indicated an upward non-flow adjusted trend at the two northern sites (South Fabius and Grand Rivers). The increase in total suspended solids concentrations could be because of soil erosion from land cultivated for row crops. Most trace element data examined in the study were highly censored and could not be used for flow-adjusted trend analyses. Water-quality conditions were assessed to explore relations between data from sites and to the State water-quality standards where applicable for selected constituents. Streamflow varied at each site because of drainage area, land use, and groundwater inputs. Dissolved oxygen and water temperature were similar at all sites except the urban site located on Wilson Creek. Specific conductance was similar between the most northern (South Fabius and Grand River sites) and the most southern sites (Current and Elk River sites). Total suspended solids concentrations were near the method reporting level at all sites, except the northern sites. Streams in northern Missouri are more turbid than streams in southern Missouri and are affected by large volumes of sediment deposition because of soil erosion from land cultivated for row crops. Geometric means of Escherichia coli were calculated from the recreational seasons within the study period. Only the Grand River site exceeded the whole-body-contact standard for frequently used waters. The South Fabius and Grand River sites and the Wilson Creek site had statistically larger densities of both fecal indicator bacteria types than the remaining sites.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3254684','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3254684"><span>Widening of xylem conduits in a conifer tree depends on the longer time of cell expansion downwards along the stem</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Anfodillo, Tommaso; Deslauriers, Annie; Menardi, Roberto; Tedoldi, Laura; Petit, Giai; Rossi, Sergio</p> <p>2012-01-01</p> <p>The diameter of vascular conduits increases towards the stem base. It has been suggested that this profile is an efficient anatomical feature for reducing the hydraulic resistance when trees grow taller. However, the mechanism that controls the cell diameter along the plant is not fully understood. The timing of cell differentiation along the stem was investigated. Cambial activity and cell differentiation were investigated in a Picea abies tree (11.5 m in height) collecting microsamples at nine different heights (from 1 to 9 m) along the stem with a 4 d time interval. Wood sections (8–12 μm thick) were stained and observed under a light microscope with polarized light to differentiate the developing xylem cells. Cell wall lignification was detected using cresyl violet acetate. The first enlarging cells appeared almost simultaneously along the tree axis indicating that cambium activation is not height-dependent. A significant increase in the duration of the cell expansion phase was observed towards the tree base: at 9 m from the ground, xylem cells expanded for 7 d, at 6 m for 14 d, and at 3 m for 19 d. The duration of the expansion phase is positively correlated with the lumen area of the tracheids (r2=0.68, P < 0.01) at the same height. By contrast, thickness of the cell wall of the earlywood did not show any trend with height. The lumen area of the conduits down the stem appeared linearly dependent on time during which differentiating cells remained in the expansion phase. However, the inductive signal of such long-distance patterned differentiation remains to be identified. PMID:22016427</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22016427','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22016427"><span>Widening of xylem conduits in a conifer tree depends on the longer time of cell expansion downwards along the stem.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Anfodillo, Tommaso; Deslauriers, Annie; Menardi, Roberto; Tedoldi, Laura; Petit, Giai; Rossi, Sergio</p> <p>2012-01-01</p> <p>The diameter of vascular conduits increases towards the stem base. It has been suggested that this profile is an efficient anatomical feature for reducing the hydraulic resistance when trees grow taller. However, the mechanism that controls the cell diameter along the plant is not fully understood. The timing of cell differentiation along the stem was investigated. Cambial activity and cell differentiation were investigated in a Picea abies tree (11.5 m in height) collecting microsamples at nine different heights (from 1 to 9 m) along the stem with a 4 d time interval. Wood sections (8-12 μm thick) were stained and observed under a light microscope with polarized light to differentiate the developing xylem cells. Cell wall lignification was detected using cresyl violet acetate. The first enlarging cells appeared almost simultaneously along the tree axis indicating that cambium activation is not height-dependent. A significant increase in the duration of the cell expansion phase was observed towards the tree base: at 9 m from the ground, xylem cells expanded for 7 d, at 6 m for 14 d, and at 3 m for 19 d. The duration of the expansion phase is positively correlated with the lumen area of the tracheids (r(2)=0.68, P < 0.01) at the same height. By contrast, thickness of the cell wall of the earlywood did not show any trend with height. The lumen area of the conduits down the stem appeared linearly dependent on time during which differentiating cells remained in the expansion phase. However, the inductive signal of such long-distance patterned differentiation remains to be identified.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1813994K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1813994K"><span>Attempting to link hydro-morphology, transient storage and metabolism in streams: Insights from reactive tracer experiments</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kurz, Marie J.; Schmidt, Christian; Blaen, Phillip; Knapp, Julia L. A.; Drummond, Jennifer D.; Martí, Eugenia; Zarnetske, Jay P.; Ward, Adam S.; Krause, Stefan</p> <p>2016-04-01</p> <p>In-stream transient storage zones, including the hyporheic zone and vegetation beds, can be hotspots of biogeochemical processing in streams, enhancing ecosystem functions such as metabolism and nutrient uptake. The spatio-temporal dynamics and reactivity of these storage zones are influenced by multiple factors, including channel geomorphology, substrate composition and hydrology, and by anthropogenic modifications to flow regimes and nutrient loads. Tracer injections are a commonly employed method to evaluate solute transport and transient storage in streams; however, reactive tracers are needed to differentiate between metabolically active and inactive transient storage zones. The reactive stream tracer resazurin (Raz), a weakly fluorescent dye which irreversibly transforms to resorufin (Rru) under mildly reducing conditions, provides a proxy for aerobic respiration and an estimate of the metabolic activity associated with transient storage zones. Across a range of lotic ecosystems, we try to assess the influence of stream channel hydro-morphology, morphologic heterogeneity, and substrate type on reach (103 m) and sub-reach (102 m) scale transient storage, respiration, and nutrient uptake. To do so, we coupled injections of Raz and conservative tracers (uranine and/or salt) at each study site. The study sites included: vegetated mesocosms controlled for water depth; vegetated and un-vegetated sediment-filled mesocosms fed by waste-water effluent; a contrasting sand- vs. gravel-bedded lowland stream (Q = 0.08 m3/s); and a series of upland streams with varying size (Q = 0.1 - 1.5 m3/s) and prevalence of morphologic features. Continuous time-series of tracer concentrations were recorded using in-situ fluorometers and EC loggers. At the stream sites, time-series were recorded at multiple downstream locations in order to resolve sub-reach dynamics. Analyses yielded highly variable transport metrics and Raz-Rru transformation between study sites and between sub-reaches within stream sites. Higher Raz-Rru transformation rates were typically observed in smaller streams, in sub-reaches with higher prevalence of morphologic features known to promote hyporheic exchange, and in mesocosms with higher water depth, vegetation density and retention time. However, relationships between transformation rates and common metrics of transient storage were not consistent among study cases, indicating the existence of yet unrealized complexities in the relationships between water and solute transport and metabolism. Further insights were also gained related to the utility of Raz and improved tracer test practices.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20020049822&hterms=perception&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dperception','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20020049822&hterms=perception&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dperception"><span>Up-down Asymmetries in Speed Perception</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Thompson, Peter; Stone, Leland S.</p> <p>1997-01-01</p> <p>We compared speed matches for pairs of stimuli that moved in opposite directions (upward and downward). Stimuli were elliptical patches (2 deg horizontally by 1 deg vertically) of horizontal sinusoidal gratings of spatial. frequency 2 cycles/deg. Two sequential 380 msec reveal presentations were compared. One of each pair of gratings (the standard) moved at 4 Hz (2 deg/sec), the other (the test) moved at a rate determined by a simple up-down staircase. The point of subjectively equal speed was calculated from the average of the last eight reversals. The task was to fixate a central point and to determine which one of the pair appeared to move faster. Eight of 10 observers perceived the upward drifting grating as moving faster than a grating moving downward but otherwise identical. on average (N = 10), when the standard moved downward, it was matched by a test moving upward at 94.7+/-1.7(SE)% of the standard speed, and when the standard moved upward it was matched by a test moving downward at 105.1+/-2.3(SE)% of the standard speed. Extending this paradigm over a range of spatial (1.5 to 13.5 c/d) and temporal (1.5 to 13.5 Hz) frequencies, preliminary results (N = 4) suggest that, under the conditions of our experiment, upward matter is seen as faster than downward for speeds greater than approx.1 deg/sec, but the effect appears to reverse at speeds below approx.1 deg/sec with downward motion perceived as faster. Given that an up-down asymmetry has been observed for the optokinetic response, both perceptual and oculomotor contributions to this phenomenon deserve exploration.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27808377','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27808377"><span>Comparison and analysis of Wuding and avian chicken skeletal muscle satellite cells.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tong, H Q; Jiang, Z Q; Dou, T F; Li, Q H; Xu, Z Q; Liu, L X; Gu, D H; Rong, H; Huang, Y; Chen, X B; Jois, M; Te Pas, M F W; Ge, C R; Jia, J J</p> <p>2016-10-05</p> <p>Chicken skeletal muscle satellite cells are located between the basement membrane and the sarcolemma of mature muscle fibers. Avian broilers have been genetically selected based on their high growth velocity and large muscle mass. The Wuding chicken is a famous local chicken in Yunnan Province that undergoes non-selection breeding and is slow growing. In this study, we aimed to explore differences in the proliferation and differentiation properties of satellite cells isolated from the two chicken breeds. Using immunofluorescence, hematoxylin-eosin staining and real-time polymerase chain reaction analysis, we analyzed the in vitro characteristics of proliferating and differentiating satellite cells isolated from the two chicken breeds. The growth curve of satellite cells was S-shaped, and cells from Wuding chickens entered the logarithmic phase and plateau phase 1 day later than those from Avian chicken. The results also showed that the two skeletal muscle satellite cell lines were positive for Pax7, MyoD and IGF-1. The expression of Pax7 followed a downward trend, whereas that of MyoD and IGF-1 first increased and subsequently decreased in cells isolated from the two chickens. These data indicated that the skeletal muscle satellite cells of Avian chicken grow and differentiate faster than did those of Wuding chickens. We suggest that the methods of breeding selection applied to these breeds regulate the characteristics of skeletal muscle satellite cells to influence muscle growth.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20543527','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20543527"><span>Longitudinal trends of total white blood cell and differential white blood cell counts of atomic bomb survivors.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hsu, Wan-Ling; Tatsukawa, Yoshimi; Neriishi, Kazuo; Yamada, Michiko; Cologne, John; Fujiwara, Saeko</p> <p>2010-01-01</p> <p>In studying the late health effects of atomic-bomb (A-bomb) survivors, earlier findings were that white blood cell (WBC) count increased with radiation dose in cross-sectional studies. However, a persistent effect of radiation on WBC count and other risk factors has yet to be confirmed. The objectives of the present study were 1) to examine the longitudinal relationship between A-bomb radiation dose and WBC and differential WBC counts among A-bomb survivors and 2) to investigate the potential confounding risk factors (such as age at exposure and smoking status) as well as modification of the radiation dose-response. A total of 7,562 A-bomb survivors in Hiroshima and Nagasaki were included in this study from 1964-2004. A linear mixed model was applied using the repeated WBC measurements. During the study period, a secular downward trend of WBC count was observed. Radiation exposure was a significant risk factor for elevated WBC and differential WBC counts over time. A significant increase of WBC counts among survivors with high radiation dose (> 2 Gy) was detected in men exposed below the age of 20 and in women regardless of age at exposure. Effects on WBC of low dose radiation remain unclear, however. Cigarette smoking produced the most pronounced effect on WBC counts and its impact was much larger than that of radiation exposure.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23662861','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23662861"><span>Objects and categories: feature statistics and object processing in the ventral stream.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tyler, Lorraine K; Chiu, Shannon; Zhuang, Jie; Randall, Billi; Devereux, Barry J; Wright, Paul; Clarke, Alex; Taylor, Kirsten I</p> <p>2013-10-01</p> <p>Recognizing an object involves more than just visual analyses; its meaning must also be decoded. Extensive research has shown that processing the visual properties of objects relies on a hierarchically organized stream in ventral occipitotemporal cortex, with increasingly more complex visual features being coded from posterior to anterior sites culminating in the perirhinal cortex (PRC) in the anteromedial temporal lobe (aMTL). The neurobiological principles of the conceptual analysis of objects remain more controversial. Much research has focused on two neural regions-the fusiform gyrus and aMTL, both of which show semantic category differences, but of different types. fMRI studies show category differentiation in the fusiform gyrus, based on clusters of semantically similar objects, whereas category-specific deficits, specifically for living things, are associated with damage to the aMTL. These category-specific deficits for living things have been attributed to problems in differentiating between highly similar objects, a process that involves the PRC. To determine whether the PRC and the fusiform gyri contribute to different aspects of an object's meaning, with differentiation between confusable objects in the PRC and categorization based on object similarity in the fusiform, we carried out an fMRI study of object processing based on a feature-based model that characterizes the degree of semantic similarity and difference between objects and object categories. Participants saw 388 objects for which feature statistic information was available and named the objects at the basic level while undergoing fMRI scanning. After controlling for the effects of visual information, we found that feature statistics that capture similarity between objects formed category clusters in fusiform gyri, such that objects with many shared features (typical of living things) were associated with activity in the lateral fusiform gyri whereas objects with fewer shared features (typical of nonliving things) were associated with activity in the medial fusiform gyri. Significantly, a feature statistic reflecting differentiation between highly similar objects, enabling object-specific representations, was associated with bilateral PRC activity. These results confirm that the statistical characteristics of conceptual object features are coded in the ventral stream, supporting a conceptual feature-based hierarchy, and integrating disparate findings of category responses in fusiform gyri and category deficits in aMTL into a unifying neurocognitive framework.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27450415','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27450415"><span>Did policies to abate atmospheric emissions from traffic have a positive effect in London?</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Font, Anna; Fuller, Gary W</p> <p>2016-11-01</p> <p>A large number of policy initiatives are being taken at the European level, across the United Kingdom and in London to improve air quality and reduce population exposure to harmful pollutants from traffic emissions. Trends in roadside increments of nitrogen oxides (NO X ), nitrogen dioxide (NO 2 ), particulate matter (PM), black carbon (CBLK) and carbon dioxide (CO 2 ) were examined at 65 London monitoring sites for two periods of time: 2005-2009 and 2010-2014. Between 2005 and 2009 there was an overall increase in NO 2 reflecting the growing evidence of real world emissions from diesel vehicles. Conversely, NO 2 decreased by 10%·year -1 from 2010 onwards along with PM 2.5 (-28%·year -1 ) and black carbon (-11%·year -1 ). Downwards trends in air pollutants were not fully explained by changes in traffic counts therefore traffic exhaust emission abatement policies were proved to be successful in some locations. PM 10 concentrations showed no significant overall change suggesting an increase in coarse particles which offset the decrease in tailpipe emissions; this was especially the case on roads in outer London where an increase in the number of Heavy Good Vehicles (HGVs) was seen. The majority of roads with increasing NO X experienced an increase in buses and coaches. Changes in CO 2 from 2010 onwards did not match the downward predictions from reduced traffic flows and improved fleet efficiency. CO 2 increased along with increasing HGVs and buses. Polices to manage air pollution provided differential benefits across London's road network. To investigate this, k-means clustering technique was applied to group roads which behaved similarly in terms of trends to evaluate the effectiveness of policies to mitigate traffic emissions. This is the first time that London's roadside monitoring sites have been considered as a population rather than summarized as a mean behaviour only, allowing greater insight into the differential changes in air pollution abatement policies. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GeoRL..45.1277M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GeoRL..45.1277M"><span>Diverse Electron and Ion Acceleration Characteristics Observed Over Jupiter's Main Aurora</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mauk, B. H.; Haggerty, D. K.; Paranicas, C.; Clark, G.; Kollmann, P.; Rymer, A. M.; Peachey, J. M.; Bolton, S. J.; Levin, S. M.; Adriani, A.; Allegrini, F.; Bagenal, F.; Bonfond, B.; Connerney, J. E. P.; Ebert, R. W.; Gladstone, G. R.; Kurth, W. S.; McComas, D. J.; Ranquist, D.; Valek, P.</p> <p>2018-02-01</p> <p>Two new Juno-observed particle features of Jupiter's main aurora demonstrate substantial diversity of processes generating Jupiter's mysterious auroral emissions. It was previously speculated that sometimes-observed potential-driven aurora (up to 400 kV) can turn into broadband stochastic acceleration (dominating at Jupiter) by means of instability. Here direct evidence for such a process is revealed with a "mono-energetic" electron inverted-V rising in energy to 200 keV, transforming into a region of broadband acceleration with downward energy fluxes tripling to 3,000 mW/m2, and then transforming back into a mono-energetic structure ramping down from 200 keV. But a second feature of interest observed nearby is unlikely to have operated in the same way. Here a downward accelerated proton inverted-V, with inferred potentials to 300-400 kV, occurred simultaneously with downward accelerated broadband electrons with downward energy fluxes as high as any observed ( 3,000 mW/m2). This latter feature has no known precedent with Earth auroral observations.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GeoRL..45.3461Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GeoRL..45.3461Z"><span>Numerical Solutions of the Mean-Value Theorem: New Methods for Downward Continuation of Potential Fields</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Chong; Lü, Qingtian; Yan, Jiayong; Qi, Guang</p> <p>2018-04-01</p> <p>Downward continuation can enhance small-scale sources and improve resolution. Nevertheless, the common methods have disadvantages in obtaining optimal results because of divergence and instability. We derive the mean-value theorem for potential fields, which could be the theoretical basis of some data processing and interpretation. Based on numerical solutions of the mean-value theorem, we present the convergent and stable downward continuation methods by using the first-order vertical derivatives and their upward continuation. By applying one of our methods to both the synthetic and real cases, we show that our method is stable, convergent and accurate. Meanwhile, compared with the fast Fourier transform Taylor series method and the integrated second vertical derivative Taylor series method, our process has very little boundary effect and is still stable in noise. We find that the characters of the fading anomalies emerge properly in our downward continuation with respect to the original fields at the lower heights.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19830046596&hterms=protein+synthesis&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dprotein%2Bsynthesis','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19830046596&hterms=protein+synthesis&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dprotein%2Bsynthesis"><span>Protein synthesis in geostimulated root caps</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Feldman, L. J.</p> <p>1982-01-01</p> <p>A study is presented of the processes occurring in the root cap of corn which are requisite for the formation of root cap inhibitor and which can be triggered or modulated by both light and gravity. The results of this study indicate the importance of protein synthesis for light-induced gravitropic bending in roots. Root caps in which protein synthesis is prevented are unable to induce downward bending. This suggests that light acts by stimulating proteins which are necessary for the translation of the gravitropic stimulus into a growth response (downward bending). The turnover of protein with time was also examined in order to determine whether light acts by stimulating the synthesis of unique proteins required for downward growth. It is found that auxin in combination with light allows for the translation of the gravitropic stimulus into a growth response at least in part through the modification of protein synthesis. It is concluded that unique proteins are stimulated by light and are involved in promoting the downward growth in roots which are responding to gravity.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28777811','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28777811"><span>A machine learning approach to estimation of downward solar radiation from satellite-derived data products: An application over a semi-arid ecosystem in the U.S.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhou, Qingtao; Flores, Alejandro; Glenn, Nancy F; Walters, Reggie; Han, Bangshuai</p> <p>2017-01-01</p> <p>Shortwave solar radiation is an important component of the surface energy balance and provides the principal source of energy for terrestrial ecosystems. This paper presents a machine learning approach in the form of a random forest (RF) model for estimating daily downward solar radiation flux at the land surface over complex terrain using MODIS (MODerate Resolution Imaging Spectroradiometer) remote sensing data. The model-building technique makes use of a unique network of 16 solar flux measurements in the semi-arid Reynolds Creek Experimental Watershed and Critical Zone Observatory, in southwest Idaho, USA. Based on a composite RF model built on daily observations from all 16 sites in the watershed, the model simulation of downward solar radiation matches well with the observation data (r2 = 0.96). To evaluate model performance, RF models were built from 12 of 16 sites selected at random and validated against the observations at the remaining four sites. Overall root mean square errors (RMSE), bias, and mean absolute error (MAE) are small (range: 37.17 W/m2-81.27 W/m2, -48.31 W/m2-15.67 W/m2, and 26.56 W/m2-63.77 W/m2, respectively). When extrapolated to the entire watershed, spatiotemporal patterns of solar flux are largely consistent with expected trends in this watershed. We also explored significant predictors of downward solar flux in order to reveal important properties and processes controlling downward solar radiation. Based on the composite RF model built on all 16 sites, the three most important predictors to estimate downward solar radiation include the black sky albedo (BSA) near infrared band (0.858 μm), BSA visible band (0.3-0.7 μm), and clear day coverage. This study has important implications for improving the ability to derive downward solar radiation through a fusion of multiple remote sensing datasets and can potentially capture spatiotemporally varying trends in solar radiation that is useful for land surface hydrologic and terrestrial ecosystem modeling.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5544233','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5544233"><span>A machine learning approach to estimation of downward solar radiation from satellite-derived data products: An application over a semi-arid ecosystem in the U.S.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Flores, Alejandro; Glenn, Nancy F.; Walters, Reggie; Han, Bangshuai</p> <p>2017-01-01</p> <p>Shortwave solar radiation is an important component of the surface energy balance and provides the principal source of energy for terrestrial ecosystems. This paper presents a machine learning approach in the form of a random forest (RF) model for estimating daily downward solar radiation flux at the land surface over complex terrain using MODIS (MODerate Resolution Imaging Spectroradiometer) remote sensing data. The model-building technique makes use of a unique network of 16 solar flux measurements in the semi-arid Reynolds Creek Experimental Watershed and Critical Zone Observatory, in southwest Idaho, USA. Based on a composite RF model built on daily observations from all 16 sites in the watershed, the model simulation of downward solar radiation matches well with the observation data (r2 = 0.96). To evaluate model performance, RF models were built from 12 of 16 sites selected at random and validated against the observations at the remaining four sites. Overall root mean square errors (RMSE), bias, and mean absolute error (MAE) are small (range: 37.17 W/m2-81.27 W/m2, -48.31 W/m2-15.67 W/m2, and 26.56 W/m2-63.77 W/m2, respectively). When extrapolated to the entire watershed, spatiotemporal patterns of solar flux are largely consistent with expected trends in this watershed. We also explored significant predictors of downward solar flux in order to reveal important properties and processes controlling downward solar radiation. Based on the composite RF model built on all 16 sites, the three most important predictors to estimate downward solar radiation include the black sky albedo (BSA) near infrared band (0.858 μm), BSA visible band (0.3–0.7 μm), and clear day coverage. This study has important implications for improving the ability to derive downward solar radiation through a fusion of multiple remote sensing datasets and can potentially capture spatiotemporally varying trends in solar radiation that is useful for land surface hydrologic and terrestrial ecosystem modeling. PMID:28777811</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007JCHyd..91....4C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007JCHyd..91....4C"><span>The chemical response of particle-associated contaminants in aquatic sediments to urbanization in New England, U.S.A.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chalmers, A. T.; Van Metre, P. C.; Callender, E.</p> <p>2007-04-01</p> <p>Relations between urbanization and particle-associated contaminants in New England were evaluated using a combination of samples from sediment cores, streambed sediments, and suspended stream sediments. Concentrations of PAHs, PCBs, DDT, and seven trace metals (Cd, Cr, Cu, Hg, Ni, Pb, Zn) were correlated strongly with urbanization, with the strongest relations to percentage commercial, industrial, and transportation (CIT) land use. Average PAH and metal concentrations in the most urbanized watersheds were approximately 30 and 6 times the reference concentrations, respectively, in remote, undeveloped watersheds. One-quarter to one-half of sampling sites had concentrations of PAHs, Cu, Pb, or Zn above the probable effects concentration, a set of sediment quality guidelines for adverse effects to aquatic biota, and sediments were predicted to be toxic, on average, when CIT land use exceeded about 10%. Trends in metals in cores from urban watersheds were dominantly downward, whereas trends in PAHs in a suburban watershed were upward. A regional atmospheric-fallout gradient was indicated by as much as order-of-magnitude-greater concentrations and accumulation rates of contaminants in cores from an undeveloped reference lake in Boston compared to those from remote reference watersheds. Contaminant accumulation rates in the lakes with urbanization in their watersheds, however, were 1-3 orders of magnitude greater than those of reference lakes, which indicate the dominance of local sources and fluvial transport of contaminants to urban lakes. These analyses demonstrate the magnitude of urban contamination of aquatic systems and air sheds, and suggest that, despite reductions in contaminant emissions in urban settings, streams and lakes will decline in quality as urbanization of their watersheds takes place.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/wri/1995/4163/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/wri/1995/4163/report.pdf"><span>Water-quality assessment of the Kentucky River basin, Kentucky; results of investigations of surface-water quality, 1987-90</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Haag, K.H.; Garcia, Rene; Jarrett, G.L.; Porter, S.D.</p> <p>1995-01-01</p> <p>The U.S. Geological Survey investigated the water quality of the Kentucky River Basin in Kentucky as part of the National Water-Quality Assessment program. Data collected during 1987-90 were used to describe the spatial and temporal variability of water-quality constituents including metals and trace elements, nutrients, sediments, pesticides, dissolved oxygen, and fecal-coliform bacteria. Oil-production activities were the source of barium, bromide, chloride, magnesium, and sodium in several watersheds. High concentrations of aluminum, iron, and zinc were related to surface mining in the Eastern Coal Field Region. High concentrations of lead and zinc occurred in streambed sediments in urban areas, whereas concentrations of arsenic, strontium, and uranium were associated with natural geologic sources. Concentrations of phosphorus were significantly correlated with urban and agricultural land use. The high phosphorus content of Bluegrass Region soils was an important source of phosphorus in streams. At many sites in urban areas, most of the stream nitrogen load was attributable to wastewater-treatment-plant effluent. Average suspended-sediment concentrations were positively correlated with discharge. There was a downward trend in suspended-sediment concentrations downstream in the Kentucky River main stem during the study. The most frequently detected herbicides in water samples were atrazine, 2,4-D, alachlor, metolachlor, and dicamba. Diazinon, malathion, and parathion were the most frequently detected organophosphate insecticides in water samples. Detectable concentrations of aldrin, chlordane, DDT, DDE, dieldrin, endrin, endosulfan, heptachlor, and lindane were found in streambed-sediment samples. Dissolved-oxygen concentrations were sometimes below the minimum concentration needed to sustain aquatic life. At some sites, high concentrations of fecal-indicator bacteria were found and water samples did not meet sanitary water-quality criteria.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140016843','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140016843"><span>Meteorology of Jupiter's Equatorial Hot Spots and Plumes from Cassini</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Choi, David Sanghun; Showman, Adam P.; Vasavada, Ashwin R.; Simon-Miller, Amy A.</p> <p>2013-01-01</p> <p>We present an updated analysis of Jupiter's equatorial meteorology from Cassini observations. For two months preceding the spacecraft's closest approach, the Imaging Science Subsystem (ISS) onboard regularly imaged the atmosphere. We created time-lapse movies from this period in order to analyze the dynamics of equatorial hot spots and their interactions with adjacent latitudes. Hot spots are relatively cloud-free regions that emit strongly at 5 lm; improved knowledge of these features is crucial for fully understanding Galileo probe measurements taken during its descent through one. Hot spots are quasistable, rectangular dark areas on visible-wavelength images, with defined eastern edges that sharply contrast with surrounding clouds, but diffuse western edges serving as nebulous boundaries with adjacent equatorial plumes. Hot spots exhibit significant variations in size and shape over timescales of days and weeks. Some of these changes correspond with passing vortex systems from adjacent latitudes interacting with hot spots. Strong anticyclonic gyres present to the south and southeast of the dark areas appear to circulate into hot spots. Impressive, bright white plumes occupy spaces in between hot spots. Compact cirrus-like 'scooter' clouds flow rapidly through the plumes before disappearing within the dark areas. These clouds travel at 150-200 m/s, much faster than the 100 m/s hot spot and plume drift speed. This raises the possibility that the scooter clouds may be more illustrative of the actual jet stream speed at these latitudes. Most previously published zonal wind profiles represent the drift speed of the hot spots at their latitude from pattern matching of the entire longitudinal image strip. If a downward branch of an equatorially-trapped Rossby wave controls the overall appearance of hot spots, however, the westward phase velocity of the wave leads to underestimates of the true jet stream speed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70030131','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70030131"><span>The chemical response of particle-associated contaminants in aquatic sediments to urbanization in New England, U.S.A.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Chalmers, A.T.; Van Metre, P.C.; Callender, E.</p> <p>2007-01-01</p> <p>Relations between urbanization and particle-associated contaminants in New England were evaluated using a combination of samples from sediment cores, streambed sediments, and suspended stream sediments. Concentrations of PAHs, PCBs, DDT, and seven trace metals (Cd, Cr, Cu, Hg, Ni, Pb, Zn) were correlated strongly with urbanization, with the strongest relations to percentage commercial, industrial, and transportation (CIT) land use. Average PAH and metal concentrations in the most urbanized watersheds were approximately 30 and 6 times the reference concentrations, respectively, in remote, undeveloped watersheds. One-quarter to one-half of sampling sites had concentrations of PAHs, Cu, Pb, or Zn above the probable effects concentration, a set of sediment quality guidelines for adverse effects to aquatic biota, and sediments were predicted to be toxic, on average, when CIT land use exceeded about 10%. Trends in metals in cores from urban watersheds were dominantly downward, whereas trends in PAHs in a suburban watershed were upward. A regional atmospheric-fallout gradient was indicated by as much as order-of-magnitude-greater concentrations and accumulation rates of contaminants in cores from an undeveloped reference lake in Boston compared to those from remote reference watersheds. Contaminant accumulation rates in the lakes with urbanization in their watersheds, however, were 1-3 orders of magnitude greater than those of reference lakes, which indicate the dominance of local sources and fluvial transport of contaminants to urban lakes. These analyses demonstrate the magnitude of urban contamination of aquatic systems and air sheds, and suggest that, despite reductions in contaminant emissions in urban settings, streams and lakes will decline in quality as urbanization of their watersheds takes place. ?? 2006 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.U13B..37H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.U13B..37H"><span>The influence of Critical Zone structure on runoff paths, seasonal water storage, and ecosystem composition</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hahm, W. J.; Dietrich, W. E.; Rempe, D.; Dralle, D.; Dawson, T. E.; Lovill, S.; Bryk, A.</p> <p>2017-12-01</p> <p>Understanding how subsurface water storage mediates water availability to ecosystems is crucial for elucidating linkages between water, energy, and carbon cycles from local to global scales. Earth's Critical Zone (the CZ, which extends from the top of the vegetation canopy downward to fresh bedrock) includes fractured and weathered rock layers that store and release water, thereby contributing to ecosystem water supplies, and yet are not typically represented in land-atmosphere models. To investigate CZ structural controls on water storage dynamics, we intensively studied field sites in a Mediterranean climate where winter rains arrive months before peak solar energy availability, resulting in strong summertime ecosystem reliance on stored subsurface water. Intra-hillslope and catchment-wide observations of CZ water storage capacity across a lithologic boundary in the Franciscan Formation of the Northern California Coast Ranges reveal large differences in the thickness of the CZ and water storage capacity that result in a stark contrast in plant community composition and stream behavior. Where the CZ is thick, rock moisture storage supports forest transpiration and slow groundwater release sustains baseflow and salmon populations. Where the CZ is thin, limited water storage is used by an oak savanna ecosystem, and streams run dry in summer due to negligible hillslope drainage. At both sites, wet season precipitation replenishes the dynamic storage deficit generated during the summer dry season, with excess winter rains exiting the watersheds via storm runoff as perched groundwater fracture flow at the thick-CZ site and saturation overland flow at the thin-CZ site. Annual replenishment of subsurface water storage even in severe drought years may lead to ecosystem resilience to climatic perturbations: during the 2011-2015 drought there was not widespread forest die-off in the study area.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120013574','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120013574"><span>Investigation of Jupiter's Equatorial Hotspots and Plumes Using Cassini ISS Observations</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Choi, David S.; Showman, A. P.; Vasavada, A. R.; Simon-Miller, A. A.</p> <p>2012-01-01</p> <p>We present updated analysis of Jupiter's equatorial meteorology from Cassini observations. For two months preceding the spacecraft's closest approach, the ISS onboard regularly imaged the atmosphere. We created time-lapse movies from this period in order to analyze the dynamics of equatorial 5-micron hot spots and their interactions with adjacent latitudes. Hot spots are quasi-stable, rectangular dark areas on visible-wavelength images, with defined eastern edges that sharply contrast with surrounding clouds, but a diffuse western edge serving as a nebulous boundary with adjacent equatorial plumes. Hot spots exhibit significant variations in size and shape over timescales of days and weeks. Some of these changes correspond with passing vortex systems from adjacent latitudes interacting with hot spots. Strong anticyclonic gyres present to the south and southeast of the dark areas appear to circulate into hot spots. Impressive, bright white plumes occupy spaces in between hot spots. Compact cirrus-iike 'scooter' clouds flow rapidly through the plumes before disappearing within the dark areas. This raises the possibility that the plumes and fast-moving clouds are at higher altitudes, because their speed does not match previously published zonal wind profiles. Most profiles represent the drift speed of the hot spots at their latitude from pattern matching of the entire longitudinal image strip. If a downward branch of an equatorially-trapped Rossby waves controls the overall appearance of hot spots, however, the westward phase velocity of the wave leads to underestimates of the true jet stream speed. Instead, our expanded data set demonstrating the rapid flow of these scooter clouds may be more illustrative of the actual jet stream speed at these latitudes. This research was supported by a NASA JDAP grant and the NASA Postdoctoral Program.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.9552K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.9552K"><span>Palaeo-ice stream pathways in the easternmost Amundsen Sea Embayment, West Antarctica</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Klages, Johann P.; Kuhn, Gerhard; Graham, Alastair G. C.; Smith, James A.; Hillenbrand, Claus-Dieter; Nitsche, Frank O.; Larter, Rob D.; Gohl, Karsten</p> <p>2015-04-01</p> <p>Multibeam swath bathymetry datasets collected over the past two decades have been compiled to identify palaeo-ice stream pathways in the easternmost Amundsen Sea Embayment. We mapped 3010 glacial landforms to reconstruct palaeo-ice flow in the ~250 km-long Abbot Glacial Trough that was occupied by a large palaeo-ice stream, fed by two tributaries (Cosgrove and Abbot) that reached the continental shelf edge during the last maximum ice-sheet advance. The mapping has enabled a clear differentiation between glacial landforms interpreted as indicative of wet- (e.g. mega-scale glacial lineations) and cold-based ice (e.g. hill-hole pairs) during the last glaciation of the continental shelf. Both the regions of fast palaeo-ice flow within the palaeo-ice stream troughs, and the regions of slow palaeo-ice flow on adjacent seafloor highs (referred to as inter-ice stream ridges) additionally record glacial landforms such as grounding-zone wedges and recessional moraines that indicate grounding line stillstands of the ice sheet during the last deglaciation from the shelf. As the palaeo-ice stream flowed along a trough with variable geometry and variable subglacial substrate, it appears that trough sections characterized by constrictions and outcropping hard substrate that changes the bed gradient, led the pace of grounding-line retreat to slow and subsequently pause, resulting in the deposition of grounding-zone wedges. The stepped retreat recorded within the Abbot Glacial Trough corresponds well to post-glacial stepped retreat interpreted for the neighbouring Pine Island-Thwaites Palaeo-Ice Stream trough, thus suggesting a uniform pattern of episodic retreat across the eastern Amundsen Sea Embayment. The correlation of episodic retreat features with geological boundaries further emphasises the significance of subglacial geology in steering ice stream flow. Our new geomorphological map of the easternmost Amundsen Sea Embayment resolves the pathways of palaeo-ice streams that were probably all active during the last maximum extent of the ice sheet on this part of the shelf, and reveals the style of postglacial grounding-line retreat. Both are important input variables in ice sheet models and therefore can be used for validating the reliability of these models.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28364762','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28364762"><span>Levitation of heavy particles against gravity in asymptotically downward flows.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Angilella, Jean-Régis; Case, Daniel J; Motter, Adilson E</p> <p>2017-03-01</p> <p>In the fluid transport of particles, it is generally expected that heavy particles carried by a laminar fluid flow moving downward will also move downward. We establish a theory to show, however, that particles can be dynamically levitated and lifted by interacting vortices in such flows, thereby moving against gravity and the asymptotic direction of the flow, even when they are orders of magnitude denser than the fluid. The particle levitation is rigorously demonstrated for potential flows and supported by simulations for viscous flows. We suggest that this counterintuitive effect has potential implications for the air-transport of water droplets and the lifting of sediments in water.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Chaos..27c1103A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Chaos..27c1103A"><span>Levitation of heavy particles against gravity in asymptotically downward flows</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Angilella, Jean-Régis; Case, Daniel J.; Motter, Adilson E.</p> <p>2017-03-01</p> <p>In the fluid transport of particles, it is generally expected that heavy particles carried by a laminar fluid flow moving downward will also move downward. We establish a theory to show, however, that particles can be dynamically levitated and lifted by interacting vortices in such flows, thereby moving against gravity and the asymptotic direction of the flow, even when they are orders of magnitude denser than the fluid. The particle levitation is rigorously demonstrated for potential flows and supported by simulations for viscous flows. We suggest that this counterintuitive effect has potential implications for the air-transport of water droplets and the lifting of sediments in water.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://eric.ed.gov/?q=%22principles+of+macroeconomics%22&id=EJ353101','ERIC'); return false;" href="https://eric.ed.gov/?q=%22principles+of+macroeconomics%22&id=EJ353101"><span>The Aggregate Demand Curve: A Reply.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Hansen, Richard B.; And Others</p> <p>1987-01-01</p> <p>Responds to claims about the instructional value of the downward-sloping aggregate demand curve in teaching principles of macroeconomics. Examines the effects of interest-rates and the role of money on demand curves. Concludes by arguing against the use of downward-sloping aggregate demand curves in textbooks. (RKM)</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22648572-decreased-proliferative-migrative-neuro-differentiative-potential-postnatal-rat-enteric-neural-crest-derived-cells-during-culture-vitro','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22648572-decreased-proliferative-migrative-neuro-differentiative-potential-postnatal-rat-enteric-neural-crest-derived-cells-during-culture-vitro"><span>Decreased proliferative, migrative and neuro-differentiative potential of postnatal rat enteric neural crest-derived cells during culture in vitro</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Yu, Hui; Institute of Neurobiology, Environment and Genes Related to Diseases Key Laboratory of Chinese Ministry of Education, Xi’an Jiaotong University, No 96, Yan Ta Xi Road, Xi’an 710061, Shaanxi; Pan, Wei-Kang</p> <p></p> <p>A growing body of evidence supports the potential use of enteric neural crest-derived cells (ENCCs) as a cell replacement therapy for Hirschsprung's disease. Based on previous observations of robust propagation of primary ENCCs, as opposed to their progeny, it is suggested that their therapeutic potential after in vitro expansion may be restricted. We therefore examined the growth and differentiation activities and phenotypic characteristics of continuous ENCC cultures. ENCCs were isolated from the intestines of postnatal rats and were identified using an immunocytochemical approach. During continuous ENCC culture expansion, proliferation, migration, apoptosis, and differentiation potentials were monitored. The Cell Counting Kit-8more » was used for assessment of ENCC vitality, Transwell inserts for cell migration, immunocytochemistry for cell counts and identification, and flow cytometry for apoptosis. Over six continuous generations, ENCC proliferation potency was reduced and with prolonged culture, the ratio of migratory ENCCs was decreased. The percentage of apoptosis showed an upward trend with prolonged intragenerational culture, but showed a downward trend with prolonged culture of combined generations. Furthermore, the percentage of peripherin{sup +} cells decreased whilst the percentage of GFAP{sup +} cells increased with age. The results demonstrated that alterations in ENCC growth characteristics occur with increased culture time, which may partially account for the poor results of proposed cell therapies. - Highlights: • Differences were identified between primary and daughter ENCCs. • Daughter ENCCs had reduced proliferation, migration and differentiation. • Daughter ENCCs also had increased apoptosis. • These altered characteristics warrant further investigation.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19880054044&hterms=pearson+communication&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dpearson%2Bcommunication','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19880054044&hterms=pearson+communication&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dpearson%2Bcommunication"><span>On a modified streamline curvature method for the Euler equations</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cordova, Jeffrey Q.; Pearson, Carl E.</p> <p>1988-01-01</p> <p>A modification of the streamline curvature method leads to a quasilinear second-order partial differential equation for the streamline coordinate function. The existence of a stream function is not required. The method is applied to subsonic and supersonic nozzle flow, and to axially symmetric flow with swirl. For many situations, the associated numerical method is both fast and accurate.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920000344&hterms=Electronic+circuits+signals+system&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DElectronic%2Bcircuits%2Bsignals%2Bsystem','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920000344&hterms=Electronic+circuits+signals+system&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DElectronic%2Bcircuits%2Bsignals%2Bsystem"><span>System Collects And Displays Demultiplexed Data</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Reschke, Millard F.; Fariss, Julie L.; Kulecz, Walter B.; Paloski, William H.</p> <p>1992-01-01</p> <p>Electronic system collects, manipulates, and displays in real time results of manipulation of streams of data transmitted from remote scientific instrumentation. Interface circuit shifts data-and-clock signal from differential logic levels of multiplexer to single-ended logic levels of computer. System accommodates nonstandard data-transmission protocol. Software useful in applications where Macintosh computers used in real-time display and recording of data.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16270857','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16270857"><span>Data streaming in telepresence environments.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lamboray, Edouard; Würmlin, Stephan; Gross, Markus</p> <p>2005-01-01</p> <p>In this paper, we discuss data transmission in telepresence environments for collaborative virtual reality applications. We analyze data streams in the context of networked virtual environments and classify them according to their traffic characteristics. Special emphasis is put on geometry-enhanced (3D) video. We review architectures for real-time 3D video pipelines and derive theoretical bounds on the minimal system latency as a function of the transmission and processing delays. Furthermore, we discuss bandwidth issues of differential update coding for 3D video. In our telepresence system-the blue-c-we use a point-based 3D video technology which allows for differentially encoded 3D representations of human users. While we discuss the considerations which lead to the design of our three-stage 3D video pipeline, we also elucidate some critical implementation details regarding decoupling of acquisition, processing and rendering frame rates, and audio/video synchronization. Finally, we demonstrate the communication and networking features of the blue-c system in its full deployment. We show how the system can possibly be controlled to face processing or networking bottlenecks by adapting the multiple system components like audio, application data, and 3D video.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011WRR....4712515P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011WRR....4712515P"><span>Hydrologic response of catchments to precipitation: Quantification of mechanical carriers and origins of water</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Park, Y.-J.; Sudicky, E. A.; Brookfield, A. E.; Jones, J. P.</p> <p>2011-12-01</p> <p>Precipitation-induced overland and groundwater flow and mixing processes are quantified to analyze the temporal (event and pre-event water) and spatial (groundwater discharge and overland runoff) origins of water entering a stream. Using a distributed-parameter control volume finite-element simulator that can simultaneously solve the fully coupled partial differential equations describing 2-D Manning and 3-D Darcian flow and advective-dispersive transport, mechanical flow (driven by hydraulic potential) and tracer-based hydrograph separation (driven by dispersive mixing as well as mechanical flow) are simulated in response to precipitation events in two cross sections oriented parallel and perpendicular to a stream. The results indicate that as precipitation becomes more intense, the subsurface mechanical flow contributions tend to become less significant relative to the total pre-event stream discharge. Hydrodynamic mixing can play an important role in enhancing pre-event tracer signals in the stream. This implies that temporally tagged chemical signals introduced into surface-subsurface flow systems from precipitation may not be strong enough to detect the changes in the subsurface flow system. It is concluded that diffusive/dispersive mixing, capillary fringe groundwater ridging, and macropore flow can influence the temporal sources of water in the stream, but any sole mechanism may not fully explain the strong pre-event water discharge. Further investigations of the influence of heterogeneity, residence time, geomorphology, and root zone processes are required to confirm the conclusions of this study.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70102311','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70102311"><span>Network analysis reveals multiscale controls on streamwater chemistry</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>McGuire, Kevin J.; Torgersen, Christian E.; Likens, Gene E.; Buso, Donald C.; Lowe, Winsor H.; Bailey, Scott W.</p> <p>2014-01-01</p> <p>By coupling synoptic data from a basin-wide assessment of streamwater chemistry with network-based geostatistical analysis, we show that spatial processes differentially affect biogeochemical condition and pattern across a headwater stream network. We analyzed a high-resolution dataset consisting of 664 water samples collected every 100 m throughout 32 tributaries in an entire fifth-order stream network. These samples were analyzed for an exhaustive suite of chemical constituents. The fine grain and broad extent of this study design allowed us to quantify spatial patterns over a range of scales by using empirical semivariograms that explicitly incorporated network topology. Here, we show that spatial structure, as determined by the characteristic shape of the semivariograms, differed both among chemical constituents and by spatial relationship (flow-connected, flow-unconnected, or Euclidean). Spatial structure was apparent at either a single scale or at multiple nested scales, suggesting separate processes operating simultaneously within the stream network and surrounding terrestrial landscape. Expected patterns of spatial dependence for flow-connected relationships (e.g., increasing homogeneity with downstream distance) occurred for some chemical constituents (e.g., dissolved organic carbon, sulfate, and aluminum) but not for others (e.g., nitrate, sodium). By comparing semivariograms for the different chemical constituents and spatial relationships, we were able to separate effects on streamwater chemistry of (i) fine-scale versus broad-scale processes and (ii) in-stream processes versus landscape controls. These findings provide insight on the hierarchical scaling of local, longitudinal, and landscape processes that drive biogeochemical patterns in stream networks.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4024884','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4024884"><span>Network analysis reveals multiscale controls on streamwater chemistry</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>McGuire, Kevin J.; Torgersen, Christian E.; Likens, Gene E.; Buso, Donald C.; Lowe, Winsor H.; Bailey, Scott W.</p> <p>2014-01-01</p> <p>By coupling synoptic data from a basin-wide assessment of streamwater chemistry with network-based geostatistical analysis, we show that spatial processes differentially affect biogeochemical condition and pattern across a headwater stream network. We analyzed a high-resolution dataset consisting of 664 water samples collected every 100 m throughout 32 tributaries in an entire fifth-order stream network. These samples were analyzed for an exhaustive suite of chemical constituents. The fine grain and broad extent of this study design allowed us to quantify spatial patterns over a range of scales by using empirical semivariograms that explicitly incorporated network topology. Here, we show that spatial structure, as determined by the characteristic shape of the semivariograms, differed both among chemical constituents and by spatial relationship (flow-connected, flow-unconnected, or Euclidean). Spatial structure was apparent at either a single scale or at multiple nested scales, suggesting separate processes operating simultaneously within the stream network and surrounding terrestrial landscape. Expected patterns of spatial dependence for flow-connected relationships (e.g., increasing homogeneity with downstream distance) occurred for some chemical constituents (e.g., dissolved organic carbon, sulfate, and aluminum) but not for others (e.g., nitrate, sodium). By comparing semivariograms for the different chemical constituents and spatial relationships, we were able to separate effects on streamwater chemistry of (i) fine-scale versus broad-scale processes and (ii) in-stream processes versus landscape controls. These findings provide insight on the hierarchical scaling of local, longitudinal, and landscape processes that drive biogeochemical patterns in stream networks. PMID:24753575</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24753575','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24753575"><span>Network analysis reveals multiscale controls on streamwater chemistry.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McGuire, Kevin J; Torgersen, Christian E; Likens, Gene E; Buso, Donald C; Lowe, Winsor H; Bailey, Scott W</p> <p>2014-05-13</p> <p>By coupling synoptic data from a basin-wide assessment of streamwater chemistry with network-based geostatistical analysis, we show that spatial processes differentially affect biogeochemical condition and pattern across a headwater stream network. We analyzed a high-resolution dataset consisting of 664 water samples collected every 100 m throughout 32 tributaries in an entire fifth-order stream network. These samples were analyzed for an exhaustive suite of chemical constituents. The fine grain and broad extent of this study design allowed us to quantify spatial patterns over a range of scales by using empirical semivariograms that explicitly incorporated network topology. Here, we show that spatial structure, as determined by the characteristic shape of the semivariograms, differed both among chemical constituents and by spatial relationship (flow-connected, flow-unconnected, or Euclidean). Spatial structure was apparent at either a single scale or at multiple nested scales, suggesting separate processes operating simultaneously within the stream network and surrounding terrestrial landscape. Expected patterns of spatial dependence for flow-connected relationships (e.g., increasing homogeneity with downstream distance) occurred for some chemical constituents (e.g., dissolved organic carbon, sulfate, and aluminum) but not for others (e.g., nitrate, sodium). By comparing semivariograms for the different chemical constituents and spatial relationships, we were able to separate effects on streamwater chemistry of (i) fine-scale versus broad-scale processes and (ii) in-stream processes versus landscape controls. These findings provide insight on the hierarchical scaling of local, longitudinal, and landscape processes that drive biogeochemical patterns in stream networks.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70032681','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70032681"><span>Hydrologic response of catchments to precipitation: Quantification of mechanical carriers and origins of water</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Park, Y.-J.; Sudicky, E.A.; Brookfield, A.E.; Jones, J.P.</p> <p>2011-01-01</p> <p>Precipitation-induced overland and groundwater flow and mixing processes are quantified to analyze the temporal (event and pre-event water) and spatial (groundwater discharge and overland runoff) origins of water entering a stream. Using a distributed-parameter control volume finite-element simulator that can simultaneously solve the fully coupled partial differential equations describing 2-D Manning and 3-D Darcian flow and advective-dispersive transport, mechanical flow (driven by hydraulic potential) and tracer-based hydrograph separation (driven by dispersive mixing as well as mechanical flow) are simulated in response to precipitation events in two cross sections oriented parallel and perpendicular to a stream. The results indicate that as precipitation becomes more intense, the subsurface mechanical flow contributions tend to become less significant relative to the total pre-event stream discharge. Hydrodynamic mixing can play an important role in enhancing pre-event tracer signals in the stream. This implies that temporally tagged chemical signals introduced into surface-subsurface flow systems from precipitation may not be strong enough to detect the changes in the subsurface flow system. It is concluded that diffusive/dispersive mixing, capillary fringe groundwater ridging, and macropore flow can influence the temporal sources of water in the stream, but any sole mechanism may not fully explain the strong pre-event water discharge. Further investigations of the influence of heterogeneity, residence time, geomorphology, and root zone processes are required to confirm the conclusions of this study. Copyright 2011 by the American Geophysical Union.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26762938','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26762938"><span>The size distribution of organic carbon in headwater streams in the Amazon basin.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>de Paula, Joana D'Arc; Luizão, Flávio Jesus; Piedade, Maria Teresa Fernandez</p> <p>2016-06-01</p> <p>Despite the strong representativeness of streams in the Amazon basin, their role in the accumulation of coarse particulate organic carbon (CPOC), fine particulate organic carbon (FPOC), and dissolved organic carbon (DOC) in transport, an important energy source in these environments, is poorly known. It is known that the arboreal vegetation in the Amazon basin is influenced by soil fertility and rainfall gradients, but would these gradients promote local differences in organic matter in headwater streams? To answer this question, 14 low-order streams were selected within these gradients along the Amazon basin, with extensions that varied between 4 and 8 km. The efficiency of the transformation of particulate into dissolved carbon fractions was assessed for each stream. The mean monthly benthic organic matter storage ranged between 1.58 and 9.40 t ha(-1) month(-1). In all locations, CPOC was the most abundant fraction in biomass, followed by FPOC and DOC. Rainfall and soil fertility influenced the distribution of the C fraction (p = 0.01), showing differentiated particulate organic carbon (POC) storage and DOC transportation along the basin. Furthermore, the results revealed that carbon quantification at the basin level could be underestimated, ultimately influencing the global carbon calculations for the region. This is especially due to the fact that the majority of studies consider only fine particulate organic matter and dissolved organic matter, which represent less than 50 % of the stored and transported carbon in streambeds.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70193247','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70193247"><span>Evidence of panmixia between sympatric life history forms of coastal cutthroat trout in two lower Columbia River tributaries</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Johnson, Jeffrey R.; Baumsteiger, Jason; Zydlewski, Joseph D.; Hudson, J. Michael; Ardren, William R.</p> <p>2010-01-01</p> <p>Coastal cutthroat trout Oncorhynchus clarkii clarkii exhibit resident and migratory life history strategies that often occur sympatrically, but the relationship between these forms within a population is poorly characterized. Through use of passive integrated transponder technology, migratory and resident coastal cutthroat trout were identified in two lower Columbia River tributaries (Abernathy Creek and the Chinook River) separated by more than 80 km. Genetic data from 17 highly variable microsatellite loci were used to ascertain the genetic population structure of these life history forms within and between streams. No distinct genetic separation was observed between the life history forms within a stream, as assessed by four different statistical approaches: permutation tests based on the genetic differentiation index F ST, principal components analysis of individuals, analysis of molecular variance, and contingency tests of allele frequency heterogeneity. Genetic differences were an order of magnitude higher between stream samples (F ST > 0.03) than between life history forms within a stream (F ST < 0.003). The contingency test detected allele frequency differences between migratory and resident life history forms in Abernathy Creek (P = 0.001), but this result was influenced more by age-class structure than by reproductive isolation between life history forms. Results are consistent with a single, randomly mating population in each stream producing both migratory and resident life history forms. These data suggest that individual life history strategy in coastal cutthroat trout is predominantly determined by phenotypic plasticity rather than genotype.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19477920','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19477920"><span>The group migration of Dictyostelium cells is regulated by extracellular chemoattractant degradation.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Garcia, Gene L; Rericha, Erin C; Heger, Christopher D; Goldsmith, Paul K; Parent, Carole A</p> <p>2009-07-01</p> <p>Starvation of Dictyostelium induces a developmental program in which cells form an aggregate that eventually differentiates into a multicellular structure. The aggregate formation is mediated by directional migration of individual cells that quickly transition to group migration in which cells align in a head-to-tail manner to form streams. Cyclic AMP acts as a chemoattractant and its production, secretion, and degradation are highly regulated. A key protein is the extracellular phosphodiesterase PdsA. In this study we examine the role and localization of PdsA during chemotaxis and streaming. We find that pdsA(-) cells respond chemotactically to a narrower range of chemoattractant concentrations compared with wild-type (WT) cells. Moreover, unlike WT cells, pdsA(-) cells do not form streams at low cell densities and form unusual thick and transient streams at high cell densities. We find that the intracellular pool of PdsA is localized to the endoplasmic reticulum, which may provide a compartment for storage and secretion of PdsA. Because we find that cAMP synthesis is normal in cells lacking PdsA, we conclude that signal degradation regulates the external cAMP gradient field generation and that the group migration behavior of these cells is compromised even though their signaling machinery is intact.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUSMNB23E..03T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUSMNB23E..03T"><span>The Influence of Leaf Fall and Organic Carbon Availability on Nitrogen Cycling in a Headwater Stream</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thomas, S. A.; Kristin, A.; Doyle, B.; Goodale, C. L.; Gurwick, N. P.; Lepak, J.; Kulkari, M.; McIntyre, P.; McCalley, C.; Raciti, S.; Simkin, S.; Warren, D.; Weiss, M.</p> <p>2005-05-01</p> <p>The study of allochthonous carbon has a long and distinguished history in stream ecology. Despite this legacy, relatively little is known regarding the influence of leaf litter on nutrient dynamics. We conducted 15N-NO3 tracer additions to a headwater stream in upstate New York before and after autumn leaf fall to assess the influence of leaf litter on nitrogen spiraling. In addition, we amended the stream with labile dissolved organic carbon (as acetate) midway through each experiment to examine whether organic carbon availability differentially stimulated nitrogen cycling. Leaf standing stocks increased from 53 to 175 g dry mass m-2 and discharge more than tripled (6 to 20 L s-1) between the pre- and post-leaf fall period. In contrast, nitrate concentration fell from approximately 50 to less then 10 ug L-1. Despite higher discharge, uptake length was shorter following leaf fall under both ambient (250 and 72 m, respectively) and DOC amended (125 and 45 m) conditions. Uptake velocity increased dramatically following leaf fall, despite a slight decline in the areal uptake rate. Dissolved N2 gas samples were also collected to estimate denitrification rates under each experimental condition. The temporal extent of increased nitrogen retention will also be explored.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21301115','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21301115"><span>Differential behaviour of Escherichia coli and Campylobacter spp. in a stream draining dairy pasture.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stott, Rebecca; Davies-Colley, Robert; Nagels, John; Donnison, Andrea; Ross, Colleen; Muirhead, Richard</p> <p>2011-03-01</p> <p>The faecal indicator bacterium Escherichia coli and thermotolerant Campylobacter spp., which are potentially pathogenic, were investigated in the Toenepi Stream draining a pastoral catchment dominated by dairying. Bacteria concentrations were monitored routinely at fortnightly intervals over 12 months and intensively during storm events to compare the transport dynamics of bacterial indicator and pathogen under varying hydro-meteorological conditions. Routine monitoring indicated median concentrations of 345 E. coli MPN 100 ml(-1) and relatively low concentrations of 2.3 Campylobacter MPN 100 ml(-1). The bacterial flux was three orders of magnitude greater under elevated stream flow compared with base-flow. E. coli peak concentrations occurred very close to the turbidity peak and consistently ahead of the Campylobacter spp. peak (which was close to the hydrograph peak). We postulate that, under flood conditions, the E. coli peak reflects the entrainment and mobilisation of in-stream stores on the flood wave front. In contrast, Campylobacter spp. are derived from wash-in from land stores upstream and have travelled at the mean water velocity which is slower than the speed of the flood wave. Our findings of different dynamics for E. coli and Campylobacter spp. suggest that mitigation to reduce faecal microbial impacts from farms will need to take account of these differences.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2710833','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2710833"><span>The Group Migration of Dictyostelium Cells Is Regulated by Extracellular Chemoattractant Degradation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Garcia, Gene L.; Rericha, Erin C.; Heger, Christopher D.; Goldsmith, Paul K.</p> <p>2009-01-01</p> <p>Starvation of Dictyostelium induces a developmental program in which cells form an aggregate that eventually differentiates into a multicellular structure. The aggregate formation is mediated by directional migration of individual cells that quickly transition to group migration in which cells align in a head-to-tail manner to form streams. Cyclic AMP acts as a chemoattractant and its production, secretion, and degradation are highly regulated. A key protein is the extracellular phosphodiesterase PdsA. In this study we examine the role and localization of PdsA during chemotaxis and streaming. We find that pdsA− cells respond chemotactically to a narrower range of chemoattractant concentrations compared with wild-type (WT) cells. Moreover, unlike WT cells, pdsA− cells do not form streams at low cell densities and form unusual thick and transient streams at high cell densities. We find that the intracellular pool of PdsA is localized to the endoplasmic reticulum, which may provide a compartment for storage and secretion of PdsA. Because we find that cAMP synthesis is normal in cells lacking PdsA, we conclude that signal degradation regulates the external cAMP gradient field generation and that the group migration behavior of these cells is compromised even though their signaling machinery is intact. PMID:19477920</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5105061','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5105061"><span>Streaming current magnetic fields in a charged nanopore</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mansouri, Abraham; Taheri, Peyman; Kostiuk, Larry W.</p> <p>2016-01-01</p> <p>Magnetic fields induced by currents created in pressure driven flows inside a solid-state charged nanopore were modeled by numerically solving a system of steady state continuum partial differential equations, i.e., Poisson, Nernst-Planck, Ampere and Navier-Stokes equations (PNPANS). This analysis was based on non-dimensional transport governing equations that were scaled using Debye length as the characteristic length scale, and applied to a finite length cylindrical nano-channel. The comparison of numerical and analytical studies shows an excellent agreement and verified the magnetic fields density both inside and outside the nanopore. The radially non-uniform currents resulted in highly non-uniform magnetic fields within the nanopore that decay as 1/r outside the nanopore. It is worth noting that for either streaming currents or streaming potential cases, the maximum magnetic field occurred inside the pore in the vicinity of nanopore wall, as opposed to a cylindrical conductor that carries a steady electric current where the maximum magnetic fields occur at the perimeter of conductor. Based on these results, it is suggested and envisaged that non-invasive external magnetic fields readouts generated by streaming/ionic currents may be viewed as secondary electronic signatures of biomolecules to complement and enhance current DNA nanopore sequencing techniques. PMID:27833119</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://eric.ed.gov/?q=brackets&pg=2&id=ED565337','ERIC'); return false;" href="https://eric.ed.gov/?q=brackets&pg=2&id=ED565337"><span>The Glass Floor: Education, Downward Mobility, and Opportunity Hoarding</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Reeves, Richard V.; Howard, Kimberly</p> <p>2013-01-01</p> <p>From an intergenerational perspective, the U.S. income distribution is sticky at both ends. Affluence and poverty are both partially inherited. Policy and research has focused on upward mobility, especially from the bottom. But relative intergenerational upward mobility is only possible with equivalent rates of downward mobility, where much less…</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title49-vol4/pdf/CFR-2011-title49-vol4-sec234-223.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title49-vol4/pdf/CFR-2011-title49-vol4-sec234-223.pdf"><span>49 CFR 234.223 - Gate arm.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-10-01</p> <p>... 49 Transportation 4 2011-10-01 2011-10-01 false Gate arm. 234.223 Section 234.223 Transportation... Maintenance Standards § 234.223 Gate arm. Each gate arm, when in the downward position, shall extend across... clearly viewed by approaching highway users. Each gate arm shall start its downward motion not less than...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title49-vol4/pdf/CFR-2010-title49-vol4-sec234-223.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title49-vol4/pdf/CFR-2010-title49-vol4-sec234-223.pdf"><span>49 CFR 234.223 - Gate arm.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-10-01</p> <p>... 49 Transportation 4 2010-10-01 2010-10-01 false Gate arm. 234.223 Section 234.223 Transportation... Maintenance Standards § 234.223 Gate arm. Each gate arm, when in the downward position, shall extend across... clearly viewed by approaching highway users. Each gate arm shall start its downward motion not less than...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ApPhL.105j3704S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ApPhL.105j3704S"><span>Characterization of adhesive properties of red blood cells using surface acoustic wave induced flows for rapid diagnostics</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sivanantha, Ninnuja; Ma, Charles; Collins, David J.; Sesen, Muhsincan; Brenker, Jason; Coppel, Ross L.; Neild, Adrian; Alan, Tuncay</p> <p>2014-09-01</p> <p>This letter presents a method which employs surface acoustic wave induced acoustic streaming to differentially peel treated red blood cells (RBCs) off a substrate based on their adhesive properties and separate populations of pathological cells from normal ones. We demonstrate the principle of operation by comparing the applied power and time required to overcome the adhesion displayed by healthy, glutaraldehyde-treated or malaria-infected human RBCs. Our experiments indicate that the method can be used to differentiate between various cell populations contained in a 9 μl droplet within 30 s, suggesting potential for rapid diagnostics.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3500304','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3500304"><span>Do Low-Mercury Terrestrial Resources Subsidize Low-Mercury Growth of Stream Fish? Differences between Species along a Productivity Gradient</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ward, Darren M.; Nislow, Keith H.; Folt, Carol L.</p> <p>2012-01-01</p> <p>Low productivity in aquatic ecosystems is associated with reduced individual growth of fish and increased concentrations of methylmercury (MeHg) in fish and their prey. However, many stream-dwelling fish species can use terrestrially-derived food resources, potentially subsidizing growth at low-productivity sites, and, because terrestrial resources have lower MeHg concentrations than aquatic resources, preventing an increase in diet-borne MeHg accumulation. We used a large-scale field study to evaluate relationships among terrestrial subsidy use, growth, and MeHg concentrations in two stream-dwelling fish species across an in-stream productivity gradient. We sampled young-of-the-year brook trout (Salvelinus fontinalis) and Atlantic salmon (Salmo salar), potential competitors with similar foraging habits, from 20 study sites in streams in New Hampshire and Massachusetts that encompassed a wide range of aquatic prey biomass. Stable isotope analysis showed that brook trout used more terrestrial resources than Atlantic salmon. Over their first growing season, Atlantic salmon tended to grow larger than brook trout at sites with high aquatic prey biomass, but brook grew two-fold larger than Atlantic salmon at sites with low aquatic prey biomass. The MeHg concentrations of brook trout and Atlantic salmon were similar at sites with high aquatic prey biomass and the MeHg concentrations of both species increased at sites with low prey biomass and high MeHg in aquatic prey. However, brook trout had three-fold lower MeHg concentrations than Atlantic salmon at low-productivity, high-MeHg sites. These results suggest that differential use of terrestrial resource subsidies reversed the growth asymmetry between potential competitors across a productivity gradient and, for one species, moderated the effect of low in-stream productivity on MeHg accumulation. PMID:23166717</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040088287&hterms=gravitropism&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D10%26Ntt%3Dgravitropism','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040088287&hterms=gravitropism&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D10%26Ntt%3Dgravitropism"><span>Complex physiological and molecular processes underlying root gravitropism</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chen, Rujin; Guan, Changhui; Boonsirichai, Kanokporn; Masson, Patrick H.</p> <p>2002-01-01</p> <p>Gravitropism allows plant organs to guide their growth in relation to the gravity vector. For most roots, this response to gravity allows downward growth into soil where water and nutrients are available for plant growth and development. The primary site for gravity sensing in roots includes the root cap and appears to involve the sedimentation of amyloplasts within the columella cells. This process triggers a signal transduction pathway that promotes both an acidification of the wall around the columella cells, an alkalinization of the columella cytoplasm, and the development of a lateral polarity across the root cap that allows for the establishment of a lateral auxin gradient. This gradient is then transmitted to the elongation zones where it triggers a differential cellular elongation on opposite flanks of the central elongation zone, responsible for part of the gravitropic curvature. Recent findings also suggest the involvement of a secondary site/mechanism of gravity sensing for gravitropism in roots, and the possibility that the early phases of graviresponse, which involve differential elongation on opposite flanks of the distal elongation zone, might be independent of this auxin gradient. This review discusses our current understanding of the molecular and physiological mechanisms underlying these various phases of the gravitropic response in roots.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://pubs.usgs.gov/wri/2002/4221/wri20024221.pdf','USGSPUBS'); return false;" href="http://pubs.usgs.gov/wri/2002/4221/wri20024221.pdf"><span>Water resources of Monroe County, New York, water years 1997-99, with emphasis on water quality in the Irondequoit Creek basin—Atmospheric deposition, ground water, streamflow, trends in water quality, and chemical loads to Irondequoit Bay</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Sherwood, Donald A.</p> <p>2003-01-01</p> <p>Irondequoit Creek drains 169 square miles in the eastern part of Monroe County. Over time, nutrients transported by Irondequoit Creek to Irondequoit Bay on Lake Ontario have contributed to the eutrophication of the bay. Sewage-treatment-plant effluent, a major source of nutrients to the creek and its tributaries, was eliminated from the basin in 1979 by diversion to a regional wastewater-treatment facility, but sediment and contaminants from nonpoint sources continue to enter the creek and Irondequoit Bay.This report, the fourth in a series of reports that present interpretive analyses of the hydrologic data collected in Monroe County since 1984, interprets data from four surface-water monitoring sites in the Irondequoit Creek basin—Irondequoit Creek at Railroad Mills, East Branch Allen Creek at Pittsford, Allen Creek near Rochester, and Irondequoit Creek at Blossom Road. It also interprets data from three sites in the the Genesee River basin—Oatka Creek at Garbutt, Honeoye Creek at Honeoye Falls, and Black Creek at Churchville—as well as the Genesee River at Charlotte Pump Station, and also from a site on Northrup Creek at North Greece. The Northrup Creek site drains a 23.5-square-mile basin in western Monroe County, and provides information on surface-water quality in streams west of the Genesee River and on loads of nutrients delivered to Long Pond, a small eutrophic embayment of Lake Ontario. The report also includes water-level and water-quality data from nine observation wells in Ellison Park, and atmospheric-deposition data from a collection site at Mendon Ponds County Park.Average annual loads of some chemical constituents in atmospheric deposition for 1997–99 differed considerably from those for the long-term period 1984–96. Ammonia and potassium loads for 1997-99 were 144 and 118 percent greater, respectively, than for the previous period. Sodium and ammonia + organic nitrogen loads were 87 and 60 percent greater, respectively. Average annual loads of sulfate and orthophosphate for 1997-99 were 36 and 30 percent lower, respectively, than for the previous period.Loads of all nutrients deposited on the Irondequoit basin from atmospheric sources during 1997–99 greatly exceeded those transported by Irondequoit Creek. The ammonia load deposited on the basin was 139 times the load transported at Blossom Road (the most downstream site); the ammonia + organic nitrogen load was 6.3 times greater, orthophosphate 7.5 times greater, total phosphorus 1.3 times greater and nitrite + nitrate 1.5 times greater. Average yields of dissolved chloride and dissolved sulfate from atmospheric sources were much smaller than those transported by streamflow at Blossom Road.chloride was about 2 percent and sulfate about 8 percent of the amount transported.Trends in concentration of chemical constituents in surface water generally can be attributed to changes in land use, annual and seasonal variations in streamflow, and annual variations in the application of road salt to county highways and roads.Concentrations of several constituents in streams of the Irondequoit Creek basin showed statistically significant (α=0.05) trends from the beginning of their period of record through 1999. The constituent with the greatest number of significant trends was ammonia + organic nitrogen, with downward trends ranging from 4.1 to 5.6 percent per year at Allen Creek, Irondequoit Creek at Blossom Road, and East Branch Allen Creek. Orthophosphate showed an upward trend of 4.1 percent per year at Irondequoit Creek at Railroad Mills (the most upstream site). Dissolved chloride showed upward trends at Railroad Mills, Allen Creek, and Blossom Road. No trends in volatile suspended solids were noted at any of the four Irondequoit basin sites.Northrup Creek showed significant downward trends in concentrations of ammonia + organic nitrogen (3.3 percent per year), total phosphorus (3.4 percent per year), and orthophosphate (5.5 percent per year), and an upward trend for dissolved sulfate (1.8 percent per year). The Genesee River at Charlotte Pump Station showed downward trends of 6.1 percent per year for ammonia + organic nitrogen and 0.1 percent per year for chloride, and upward trends of 1.7 percent per year for total phosphorus and 6.6 percent per year for orthophosphate.Mean annual yields (mass per unit area) of most constituents at the Irondequoit Creek basin sites were similar to those noted for the previous report period (1994–96). East Branch Allen Creek showed lower yields of all constituents during 1997–99 than previously, even though runoff during 1997–99 was greater. These lower yields are attributed to the construction of an upstream detention basin on East Branch Allen Creek in 1995.Statistical analysis of long-term (greater than 12 years) streamflow records for unregulated streams in Monroe County indicated that annual mean flows for water years 1997–99 were in the normal range (75th to 25th percentile), although Allen Creek continues to show a significant downward trend in mean monthly streamflow during the 1984–99 water years.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040001019','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040001019"><span>Molecular Control of Cell Growth During Gravity Responses of Maize Seedlings</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cosgrove, Daniel J.</p> <p>2003-01-01</p> <p>Gravity influences plants in many ways via its physical effects on the convective flows of gases and liquids, the buoyancy and sedimentation of cellular organelles, and the distribution of mechanical stresses in weight-bearing structures. These physical effects lead to a variety of reactions and adaptive developmental responses in plants. Perhaps the best-studied plant gravity response is gravitropism - the "homing in" of growing organs towards a particular angle with respect to gravity. Most plants respond to gravity by gravitropic bending of roots downwards and stems upwards. Such gravitropic bending arises from differential cell growth on the two sides of the bending organ. For this project we hypothesized that such growth differences arise from differences in expansin activity, which come about because of organ-level asymmetries of H+ efflux and expansin export to the wall.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820005161','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820005161"><span>On the global circulation and the hurricane system of the Jovian atmosphere</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mayr, H. G.; Meada, K.; Harris, I.</p> <p>1981-01-01</p> <p>An argument is made to support the proposal that Jupiter's red spot and the white and brown ovals are hurricanes or cyclones. Against the background of a convectively unstable troposphere, the general condition exists for the formation of hurricanes. The energy Jupiter emits must be transported upwards through the troposphere. If that transport is accelerated by the prevailing upward motions in the solar driven multicellular meridional circulation, eastward jets develop such as observed in the l region. But if that vertical transport is impeded by the prevailing downward motions in the meridional circulation, the atmosphere reacts and tends to maintain the process through the development of hurricanes. Dynamically induced by solar differential heating, an ordered latitudinal structure with alternating stability and instability is impressed on the troposphere to form alternating zonal strata where hurricanes are forbidden and permitted, respectively.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22679596-impact-surface-temperature-inhomogeneities-quiescent-neutron-star-radius-measurements','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22679596-impact-surface-temperature-inhomogeneities-quiescent-neutron-star-radius-measurements"><span>THE IMPACT OF SURFACE TEMPERATURE INHOMOGENEITIES ON QUIESCENT NEUTRON STAR RADIUS MEASUREMENTS</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Elshamouty, K. G.; Heinke, C. O.; Morsink, S. M.</p> <p></p> <p>Fitting the thermal X-ray spectra of neutron stars (NSs) in quiescent X-ray binaries can constrain the masses and radii of NSs. The effect of undetected hot spots on the spectrum, and thus on the inferred NS mass and radius, has not yet been explored for appropriate atmospheres and spectra. A hot spot would harden the observed spectrum, so that spectral modeling tends to infer radii that are too small. However, a hot spot may also produce detectable pulsations. We simulated the effects of a hot spot on the pulsed fraction and spectrum of the quiescent NSs X5 and X7 inmore » the globular cluster 47 Tucanae, using appropriate spectra and beaming for hydrogen atmosphere models, incorporating special and general relativistic effects, and sampling a range of system angles. We searched for pulsations in archival Chandra HRC-S observations of X5 and X7, placing 90% confidence upper limits on their pulsed fractions below 16%. We use these pulsation limits to constrain the temperature differential of any hot spots, and to then constrain the effects of possible hot spots on the X-ray spectrum and the inferred radius from spectral fitting. We find that hot spots below our pulsation limit could bias the spectroscopically inferred radius downward by up to 28%. For Cen X-4 (which has deeper published pulsation searches), an undetected hot spot could bias its inferred radius downward by up to 10%. Improving constraints on pulsations from quiescent LMXBs may be essential for progress in constraining their radii.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22667165-babcockleighton-solar-dynamo-role-downward-pumping-equatorward-propagation-activity','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22667165-babcockleighton-solar-dynamo-role-downward-pumping-equatorward-propagation-activity"><span>BABCOCK–LEIGHTON SOLAR DYNAMO: THE ROLE OF DOWNWARD PUMPING AND THE EQUATORWARD PROPAGATION OF ACTIVITY</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Karak, Bidya Binay; Cameron, Robert, E-mail: bkarak@ucar.edu</p> <p></p> <p>The key elements of the Babcock–Leighton dynamos are the generation of poloidal field through decay and the dispersal of tilted bipolar active regions and the generation of toroidal field through the observed differential rotation. These models are traditionally known as flux transport dynamo models as the equatorward propagations of the butterfly wings in these models are produced due to an equatorward flow at the bottom of the convection zone. Here we investigate the role of downward magnetic pumping near the surface using a kinematic Babcock–Leighton model. We find that the pumping causes the poloidal field to become predominately radial inmore » the near-surface shear layer, which allows the negative radial shear to effectively act on the radial field to produce a toroidal field. We observe a clear equatorward migration of the toroidal field at low latitudes as a consequence of the dynamo wave even when there is no meridional flow in the deep convection zone. Both the dynamo wave and the flux transport type solutions are thus able to reproduce some of the observed features of the solar cycle including the 11-year periodicity. The main difference between the two types of solutions is the strength of the Babcock–Leighton source required to produce the dynamo action. A second consequence of the magnetic pumping is that it suppresses the diffusion of fields through the surface, which helps to allow an 11-year cycle at (moderately) larger values of magnetic diffusivity than have previously been used.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1816739M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1816739M"><span>Topographyc metrics in the southern sector of the Marche foothills: implication for active tectonic analysis</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Materazzi, Marco; Aringoli, Domenico; Carducci, Tamara; Cavitolo, Paolo; Farabollini, Piero; Giacopetti, Marco; Pambianchi, Gilberto; Tondi, Emanuele; Troiani, Francesco</p> <p>2016-04-01</p> <p>Quantitative geomorphic analysis can be provided a useful contribution to the study of recent tectonics. Some parameters, that quantify the channels morphology, as the Stream Length-Gradient (SL) Index (Hack, 1973) and the Steepness (Ks) Index (Flint, 1974), are generally used to detect anomalies on the expected concave-up equilibrium stream-profile, which can result in local abrupt changes in stream gradient (i.e., knickpoints) and/or broad convexities on stream long-profiles extending for tens of kilometres (i.e., knickzones). The main goal of this work is the study of the morphological and morphometrical features in the southern sector of the Marche Region, with the aim to gain new knowledge on the influences of rock resistance and rock uplift on the fluvial and topographic system. The investigated area is situated in central Italy and it extends from the axial zone of the Umbria-Marche Apennines to the Adriatic Sea, including the southern sector of the Marche Region and belongs to the foredeep domain of the Apennines orogenic system, which has affected by tectonic activity up to very recent times. The rheology of outcropping deposits doesn't allow the strain to be easily recorded at the outcrop scale. The analyses have been aimed at to test the sensitivity of both SL and Ks for evaluating active crustal deformations, acting at different wavelengths on land surface, within a low tectonically active thrust-and-fold belt. Additional purpose was the understanding of the pattern of regional differential crustal activity in the topographic arrangement of the study area In this research project two sets of analysis were conducted. References Hack J.T. 1973. Stream-profile analysis and stream-gradient index. Journal of Research of the U.S. Geological Survey, 1, 421-429. Flint J.J. 1974. Stream gradient as a function of order, magnitude and discharge. Water Resources Research, 10, 969-973.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19750025383','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19750025383"><span>Land use mapping in Erie County, Pennsylvania: A pilot study</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mcmurtry, G. J.; Petersen, G. W. (Principal Investigator); May, G. A.</p> <p>1974-01-01</p> <p>The author has identified the following significant results. A pilot study was conducted to determine the feasibility of mapping land use in the Great Lakes Basin area utilizing ERTS-1 data. Small streams were clearly defined by the presence of trees along their length in predominantly agricultural country. Field patterns were easily differentiated from forested areas; dairy and beef farms were differentiated from other farmlands, but no attempt was made to identify crops. Large railroad lines and major highway systems were identified. The city of Erie and several smaller towns were identified, as well as residential areas between these towns, and docks along the shoreline in Erie. Marshes, forests, and beaches within Presque Isle State Park were correctly identified, using the DCLUS program. Bay water was differentiated from lake water, with a small amount of misclassification.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://eric.ed.gov/?q=organizational+behavior+AND+human+decision+processes&pg=3&id=EJ797029','ERIC'); return false;" href="https://eric.ed.gov/?q=organizational+behavior+AND+human+decision+processes&pg=3&id=EJ797029"><span>Antecedents and Consequences of the Frequency of Upward and Downward Social Comparisons at Work</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Brown, Douglas J.; Ferris, D. Lance; Heller, Daniel; Keeping, Lisa M.</p> <p>2007-01-01</p> <p>The current paper examines the dispositional and situational antecedents, as well as the attitudinal and behavioral consequences, of the frequency of upward and downward social comparisons. We predicted social comparison frequency would be influenced by uncertainty-related antecedents, and that social comparisons in organizations would be…</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.nco.ncep.noaa.gov/pmb/products/cfs','SCIGOVWS'); return false;" href="http://www.nco.ncep.noaa.gov/pmb/products/cfs"><span>CFS Products</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.science.gov/aboutsearch.html">Science.gov Websites</a></p> <p></p> <p></p> <p>vddsf.xx.YYYYMMDDHH.daily.grb2 Not Available CFS Near <em>IR</em> Diffuse Downward Solar Flux Filename Inventory Available CFS Near <em>IR</em> Diffuse Downward Solar Flux Filename Inventory nddsf.xx.YYYYMMDDHH.daily.grb2 6hrly Image of NCEP logo For questions related to this website, send mail to <em>Web</em> Manager. NCEP/NCO Production</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://eric.ed.gov/?q=Compared%2bto%2bmen&pg=4&id=EJ642350','ERIC'); return false;" href="https://eric.ed.gov/?q=Compared%2bto%2bmen&pg=4&id=EJ642350"><span>Gendered Influence of Downward Social Comparisons on Current and Possible Selves.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Kemmelmeier, Markus; Oyserman, Daphna</p> <p>2001-01-01</p> <p>Examined the gendered influence of downward social comparisons among college students. Compared to men, women were more likely to feel that another's failure reflected their own chance of success, especially when it was considered due to personal characteristics. Men were more susceptible to dampened self-evaluations in light of another's failure…</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/5884623-environmental-engineering-effects-sinkholes-processes-behind-problems','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/5884623-environmental-engineering-effects-sinkholes-processes-behind-problems"><span>Environmental and engineering effects of sinkholes - the processes behind the problems</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Beck, B.F.</p> <p>1988-10-01</p> <p>Karstic erosion of the land surface is controlled by processes occurring in the epikarstic zone-the upper portion of the limestone which is most intensely dissolved. Sinkholes developing today are generally the effects of downward movement of mantling sediment into the major karren shafts which drain the epikarstic zone deeper into the true karstic aquifer. Dissolution of the limestone itself does not cause significant changes in man's time frame. The downward erosion of mantling sediment is termed ravelling. Only in uniform sediment will an arched cavity occur. In unconsolidated sediment which is stratified, lateral tunneling may even occur. Only the majormore » karren can transmit sediment downward, the majority are ineffective. In mantled karst the location of surficial depressions and photo-linears does not necessarily correlate to areas of new collapse. The irregular and highly dissolved character of the epikarstic zone complicates foundation engineering. Downward drainage through this zone may be limited and cause flooding. An understanding of processes in the epikarstic zone is essential in developing on karst.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoRL..43.2315L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoRL..43.2315L"><span>Unexpected high 35S concentration revealing strong downward transport of stratospheric air during the monsoon transitional period in East Asia</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lin, Mang; Zhang, Zhisheng; Su, Lin; Su, Binbin; Liu, Lanzhong; Tao, Jun; Fung, Jimmy C. H.; Thiemens, Mark H.</p> <p>2016-03-01</p> <p>October is the monsoon transitional period in East Asia (EA) involving a series of synoptic activities that may enhance the downward transport of stratospheric air to the planetary boundary layer (PBL). Here we use cosmogenic 35S in sulfate aerosols (35SO42-) as a tracer for air masses originating from the stratosphere and transported downward to quantify these mixing processes. From 1 year 35SO42- measurements (March 2014 to February 2015) at a background station in EA we find remarkably enhanced 35SO42- concentration (3150 atoms m-3) in October, the highest value ever reported for natural sulfate aerosols. A four-box 1-D model and meteorological analysis reveal that strong downward transport from the free troposphere is a vital process entraining aged stratospheric air masses to the PBL. The aged stratospheric masses are accumulated in the PBL, accelerating the SO2 transformation to SO42-. Implications for the tropospheric O3 budget and the CO2 biogeochemical cycle are discussed.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1087048','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1087048"><span>Comparison of Upward and Downward Translocation of 14C From a Single Leaf of Sunflower</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Shiroya, Michi</p> <p>1968-01-01</p> <p>When single leaves attached at a given node were allowed to carry on photosynthesis in 14CO2 for 30 min, younger plants showed a higher proportion of upward translocation than did older plants. Downward translocation of 14C-photosynthate was stimulated by ATP pre-treatment of the translocating leaf, while upward translocation was not affected by ATP. A similar phenomenon was observed in the translocation of 14C-sucrose infiltrated into a leaf with or without ATP. Downward translocation of photosynthate was inhibited by DNP pre-treatment of a fed leaf. Upward translocation, however, was not affected by DNP. Thirty min after infiltration of 14C-glucose into a leaf, almost all the 14C translocated upwards was found to be in the form of glucose, while a great part of the 14C translocated downwards was in the form of sucrose. In the case of translocation of infiltrated 14C-sucrose, 14C found both above and below the fed leaf was mainly in the form of sucrose. PMID:16656944</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4234975','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4234975"><span>Dynamics associated with spontaneous differentiation of ovarian stem cells in vitro</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2014-01-01</p> <p>Background Recent studies suggest that ovarian germ line stem cells replenish oocyte-pool in adult stage, and challenge the central doctrine of ‘fixed germ cell pool’ in mammalian reproductive biology. Two distinct populations of spherical stem cells with high nucleo-cytoplasmic ratio have been recently identified in the adult mammalian ovary surface epithelium (OSE) including nuclear OCT-4A positive very small embryonic-like (VSELs) and cytoplasmic OCT-4 expressing ovarian germ stem cells (OGSCs). Three weeks culture of scraped OSE cells results in spontaneous differentiation of the stem cells into oocyte-like, parthenote-like, embryoid body-like structures and also embryonic stem cell-like colonies whereas epithelial cells attach and transform into a bed of mesenchymal cells. Present study was undertaken, to further characterize ovarian stem cells and to comprehend better the process of spontaneous differentiation of ovarian stem cells into oocyte-like structures in vitro. Methods Ovarian stem cells were enriched by immunomagnetic sorting using SSEA-4 as a cell surface marker and were further characterized. Stem cells and clusters of OGSCs (reminiscent of germ cell nests in fetal ovaries), were characterized by immuno-localization for stem and germ cell specific markers and spontaneous differentiation in OSE cultures was studied by live cell imaging. Results Differential expression of markers specific for pluripotent VSELs (nuclear OCT-4A, SSEA-4, CD133), OGSCs (cytoplasmic OCT-4) primordial germ cells (FRAGILIS, STELLA, VASA) and germ cells (DAZL, GDF-9, SCP-3) were studied. Within one week of culture, stem cells became bigger in size, developed abundant cytoplasm, differentiated into germ cells, revealed presence of Balbiani body-like structure (mitochondrial cloud) and exhibited characteristic cytoplasmic streaming. Conclusions Presence of germ cell nests, Balbiani body-like structures and cytoplasmic streaming extensively described during fetal ovary development, are indeed well recapitulated during in vitro oogenesis in adult OSE cultures along with characteristic expression of stem/germ cell/oocyte markers. Further studies are required to assess the genetic integrity of in vitro derived oocytes before harnessing their clinical potential. Advance in our knowledge about germ cell differentiation from stem cells will enable researchers to design better in vitro strategies which in turn may have relevance to reproductive biology and regenerative medicine. PMID:24568237</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18947773','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18947773"><span>Anterior urethral valves: an uncommon cause of obstructive uropathy in children.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kibar, Yusuf; Coban, Hidayet; Irkilata, H Cem; Erdemir, Fikret; Seckin, Bedrettin; Dayanc, Murat</p> <p>2007-10-01</p> <p>Anterior urethral valves (AUV) are rare entities generally described in case reports. They are an uncommon cause of lower urinary tract obstruction in children and can be difficult to diagnose. In the present study, we present our experience in four children with AUV along with a literature review. We retrospectively identified four children with AUV presented between 1998 and 2005 at age 4-9 years. Hematuria, urinary tract infection and weak voiding stream were the most common symptoms. Voiding cystourethrography (VCUG) confirmed the diagnosis of AUV. On cystourethroscopy, cusp-like valves in the anterior urethra were seen in all children. Transurethral endoscopic resection of the valves was carried out in three children using a pediatric resectoscope. In one child with a massive anterior urethral diverticulum, open resection of the valve, diverticulectomy and urethroplasty were performed. All patients were cured, none had complications as a result of surgery, and all reported a normal urinary stream at follow-up. Children with poor stream and recurrent infections should be evaluated carefully and anterior urethral valves should be considered in differential diagnosis of obstructive lesions.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110016311','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110016311"><span>System Regulates the Water Contents of Fuel-Cell Streams</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Vasquez, Arturo; Lazaroff, Scott</p> <p>2005-01-01</p> <p>An assembly of devices provides for both humidification of the reactant gas streams of a fuel cell and removal of the product water (the water generated by operation of the fuel cell). The assembly includes externally-sensing forward-pressure regulators that supply reactant gases (fuel and oxygen) at variable pressures to ejector reactant pumps. The ejector supply pressures depend on the consumption flows. The ejectors develop differential pressures approximately proportional to the consumption flow rates at constant system pressure and with constant flow restriction between the mixer-outlet and suction ports of the ejectors. For removal of product water from the circulating oxygen stream, the assembly includes a water/gas separator that contains hydrophobic and hydrophilic membranes. The water separator imposes an approximately constant flow restriction, regardless of the quality of the two-phase flow that enters it from the fuel cell. The gas leaving the water separator is nearly 100 percent humid. This gas is returned to the inlet of the fuel cell along with a quantity of dry incoming oxygen, via the oxygen ejector, thereby providing some humidification.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21319621','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21319621"><span>The simplest chronoscope II: reaction time measured by meterstick versus machine.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Montare, Alberto</p> <p>2010-12-01</p> <p>Visual simple reaction time (SRT) scores measured in 31 college students of both sexes by use of the simplest chronoscope methodology (meterstick SRT) were compared to scores obtained by use of an electromechanical multi-choice reaction timer (machine SRT). Four hypotheses were tested. Results indicated that the previous mean value of meterstick SRT was replicated; meterstick SRT was significantly faster than long-standing population estimates of mean SRT; and machine SRT was significantly slower than the same long-standing mean SRT estimates for the population. Also, the mean meterstick SRT of 181 msec. was significantly faster than the mean machine SRT of 294 msec. It was theorized that differential visual information processing occurred such that the dorsal visual stream subserved meterstick SRT; whereas the ventral visual stream subserved machine SRT.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840025462','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840025462"><span>Behavior of Al2O3 and SiO2 with heating in a Cl2 + CO stream</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shchetinin, L. K.</p> <p>1984-01-01</p> <p>Differential thermal analysis (DTA) and Thermogravimetric analysis (TGA) were used to study the chlorination of alpha-Al2O3, gamma-Al2O3 and amorphous SiO2 in a Cl + CO stream, for the preparation of AlCl3 and SiCl4. The chlorination starting temperatures were 235 deg for Al2O3 and 680 deg for SiO2. The chlorination of alpha- and gamma-Al2O3 takes place via the formation of AlOCl as an intermediate product, and its subsequent dissociation at 480 to 560 deg, according to 3AlOCl yields AlCl3 + Al2O3. The chlorination activation energies are given for the three oxides.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19800002090','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19800002090"><span>Analytical modeling of flash-back phenomena. [premixed/prevaporized combustion system</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Feng, C. C.</p> <p>1979-01-01</p> <p>To understand the flame flash-back phenomena more extensively, an analytical model was formed and a numerical program was written and tested to solve the set of differential equations describing the model. Results show that under a given set of conditions flame propagates in the boundary layer on a flat plate when the free stream is at or below 1.8 m/s.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.A41B3036Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.A41B3036Y"><span>Cloud Radiative Effect to Downward Longwave Radiation in the Polar Regions</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yamada, K.; Hayasaka, T.</p> <p>2014-12-01</p> <p>Downward longwave radiation is important factor to affect climate change. In polar regions, estimation of the radiative effect of cloud on the downward longwave radiation has large uncertainty. Relatively large cloud effect to the radiation occurs there due to low temperature, small amount of water vapor, and strong inversion layer. The cloud effect is, however, not evaluated sufficiently because the long term polar night and high surface albedo make satellite retrieval difficult. The intent of the present study is to quantify cloud radiative effect for downward longwave radiation in the polar regions by in-situ observation and radiative transfer calculation. The observation sites in this study are Ny-Ålesund (NYA), Syowa (SYO), and South Pole (SPO). These stations belong to the Baseline Surface Radiation Network. The period of data analysis is from 2003 to 2012. The effect of cloud on the downward longwave radiation is evaluated by subtraction of calculated downward longwave radiation under clear-sky condition from observed value under all-sky condition. Radiative transfer model was used for the evaluation of clear sky radiation with vertical temperature and humidity profile obtained by radiosonde observations. Calculated result shows good correlation with observation under clear-sky condition. The RMSE is +0.83±5.0. The cloud effect varied from -10 - +110 W/m2 (-10 - +40 %). Cloud effect increased with increasing of cloud fraction and decreasing of cloud base height and precipitable water. In SYO negative effects were sometimes obtained. The negative cloud effect emerged under dry and temperature inversion condition lower than 2 km. One of reasons of negative effect is considered to be existence of cloud at temperature inversion altitude. When the cloud effect is smaller than -5 W/m2 (standard deviation between calculation and observation), 50 % of them have a condition with cloud base height estimated by micro pulse lidar lower than 2 km.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/21043598-adipogenesis-bovine-perimuscular-preadipocytes','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21043598-adipogenesis-bovine-perimuscular-preadipocytes"><span>Adipogenesis of bovine perimuscular preadipocytes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Taniguchi, Masaaki; Le Luo Guan; Zhang Bing</p> <p>2008-02-01</p> <p>In this study, non-transformed progeny adipofibroblasts, derived from mature adipocyte dedifferentiation, was used as a novel in vitro model to study adipogenic gene expression in cattle. Adipofibroblasts from dedifferentiated mature perimuscular fat (PMF) tissue were cultured with differentiation stimulants until the cells exhibited morphological differentiation. Treated cells were harvested from day 2 to 16 for RNA extraction, whereas control cells were cultured without addition of stimulants. Results from time course gene expression assays by quantitative real-time PCR revealed that peroxisome proliferator-activated receptor gamma (PPAR-{gamma}), sterol regulatory element binding protein 1 (SREBP-1) and their six down-stream genes were co-expressed at daymore » 2 post-differentiation induction. When compared to other adipogenesis culture systems, the adipogenic gene expression of bovine PMF adipofibroblasts culture was different, especially to the rodent model. Collectively, these results demonstrated PPAR-{gamma} and SREBP-1 cooperatively play a key role to regulate the re-differentiation of bovine adipofibroblasts, during early conversion stages in vitro.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/863636','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/863636"><span>Heat exchanger-accumulator</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Ecker, Amir L.</p> <p>1980-01-01</p> <p>What is disclosed is a heat exchanger-accumulator for vaporizing a refrigerant or the like, characterized by an upright pressure vessel having a top, bottom and side walls; an inlet conduit eccentrically and sealingly penetrating through the top; a tubular overflow chamber disposed within the vessel and sealingly connected with the bottom so as to define an annular outer volumetric chamber for receiving refrigerant; a heat transfer coil disposed in the outer volumetric chamber for vaporizing the liquid refrigerant that accumulates there; the heat transfer coil defining a passageway for circulating an externally supplied heat exchange fluid; transferring heat efficiently from the fluid; and freely allowing vaporized refrigerant to escape upwardly from the liquid refrigerant; and a refrigerant discharge conduit penetrating sealingly through the top and traversing substantially the length of the pressurized vessel downwardly and upwardly such that its inlet is near the top of the pressurized vessel so as to provide a means for transporting refrigerant vapor from the vessel. The refrigerant discharge conduit has metering orifices, or passageways, penetrating laterally through its walls near the bottom, communicating respectively interiorly and exteriorly of the overflow chamber for controllably carrying small amounts of liquid refrigerant and oil to the effluent stream of refrigerant gas.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DFDG10003W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DFDG10003W"><span>Turbulent convection driven by internal radiative heating of melt ponds on sea ice</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wells, Andrew; Langton, Tom; Rees Jones, David; Moon, Woosok</p> <p>2016-11-01</p> <p>The melting of Arctic sea ice is strongly influenced by heat transfer through melt ponds which form on the ice surface. Melt ponds are internally heated by the absorption of incoming radiation and cooled by surface heat fluxes, resulting in vigorous buoyancy-driven convection in the pond interior. Motivated by this setting, we conduct two-dimensional direct-numerical simulations of the turbulent convective flow of a Boussinesq fluid between two horizontal boundaries, with internal heating predicted from a two-stream radiation model. A linearised thermal boundary condition describes heat exchange with the overlying atmosphere, whilst the lower boundary is isothermal. Vertically asymmetric convective flow modifies the upper surface temperature, and hence controls the partitioning of the incoming heat flux between emission at the upper and lower boundaries. We determine how the downward heat flux into the ice varies with a Rayleigh number based on the internal heating rate, the flux ratio of background surface cooling compared to internal heating, and a Biot number characterising the sensitivity of surface fluxes to surface temperature. Thus we elucidate the physical controls on heat transfer through Arctic melt ponds which determine the fate of sea ice in the summer.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040090359&hterms=gravitropism&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D50%26Ntt%3Dgravitropism','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040090359&hterms=gravitropism&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D50%26Ntt%3Dgravitropism"><span>Time-lapse analysis of gravitropism in Ceratodon protonemata</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Young, J. C.; Sack, F. D.</p> <p>1992-01-01</p> <p>The tip cell of the protonema of the moss Ceratodon purpureus (Hedw.) Brid. is negatively gravitropic when grown in the dark on supplemented agar. Gravitropism, plastid distribution, and plastid movement were studied in living cells using time-lapse video microscopy and infrared light. A wrong-way (downward) curvature preceded upward curvature and was detected as early as 2 minutes after reorientation. Upward curvature began 30-45 minutes after reorientation to the horizontal. Cell division temporarily reversed upward curvature, but did not inhibit wrong-way curvature. Since significant amyloplast sedimentation always occurred before the start of upward curvature, it is possible that these amyloplasts function as statoliths for upward curvature. However, no significant amyloplast sedimentation occurred before wrong-way curvature. Thus, this early phase of gravitropism cannot require plastid sedimentation for gravity sensing. Most plastids moved within and between zones, and plastid zonation was highly dynamic. Plastids moved toward the apex and toward the base of the cell at rates much slower than cytoplasmic streaming. Despite the dynamic nature of plastid movement and zonation, during upward curvature the distance between sedimented plastids and the apex stayed constant. Time-lapse analysis has revealed intriguing events not readily seen previously using destructive sampling.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27246329','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27246329"><span>Modern contraceptive use among migrant and non-migrant women in Kenya.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ochako, Rhoune; Askew, Ian; Okal, Jerry; Oucho, John; Temmerman, Marleen</p> <p>2016-06-01</p> <p>Manifest socio-economic differences are a trigger for internal migration in many sub-Saharan settings including Kenya. An interplay of the social, political and economic factors often lead to internal migration. Internal migration potentially has significant consequences on an individual's economic growth and on access to health services, however, there has been little research on these dynamics. In Kenya, where regional differentials in population growth and poverty reduction continue to be priorities in the post MDG development agenda, understanding the relationships between contraceptive use and internal migration is highly relevant. Using data from the 2008-09 Kenya Demographic and Health Survey (DHS), we analyze data from 5,905 women aged 15-49 years who reported being sexually active in the last 12 months prior to the survey. Bivariate and multivariate logistic regressions are fitted to predict correlates of contraceptive use in the presence of migration streams among other explanatory variables. Modern contraceptive use was significantly higher among women in all migration streams (non-migrant urban (OR = 2.8, p < 0.001), urban-urban (OR = 2.0, p < 0.001), urban-rural (OR = 2.0, p < 0.001), rural-urban (OR = 2.6, p < 0.001), rural-rural (OR = 1.7, p < 0.001), than non-migrant rural women. Women who internally migrate within Kenya, whether from rural to urban or between urban centres, were more likely to use modern contraception than non-migrant rural women. This phenomenon appears to be due to selection, adaption and disruption effects which are likely to promote use of modern contraceptives. Programmatically, the differentials in modern contraceptive use by the different migration streams should be considered when designing family planning programmes among migrant and non-migrant women.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.fws.gov/arcata/fisheries/reports/technical/2018/EstimationofStreamConditionsinTributariesoftheKlamathRiverNorthernCalifornia.pdf','USGSPUBS'); return false;" href="https://www.fws.gov/arcata/fisheries/reports/technical/2018/EstimationofStreamConditionsinTributariesoftheKlamathRiverNorthernCalifornia.pdf"><span>Estimation of stream conditions in tributaries of the Klamath River, northern California</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Manhard, Christopher V.; Som, Nicholas A.; Jones, Edward C.; Perry, Russell W.</p> <p>2018-01-01</p> <p>Because of their critical ecological role, stream temperature and discharge are requisite inputs for models of salmonid population dynamics. Coho Salmon inhabiting the Klamath Basin spend much of their freshwater life cycle inhabiting tributaries, but environmental data are often absent or only seasonally available at these locations. To address this information gap, we constructed daily averaged water temperature models that used simulated meteorological data to estimate daily tributary temperatures, and we used flow differentials recorded on the mainstem Klamath River to estimate daily tributary discharge. Observed temperature data were available for fourteen of the major salmon bearing tributaries, which enabled estimation of tributary-specific model parameters at those locations. Water temperature data from six mid-Klamath Basin tributaries were used to estimate a global set of parameters for predicting water temperatures in the remaining tributaries. The resulting parameter sets were used to simulate water temperatures for each of 75 tributaries from 1980-2015. Goodness-of-fit statistics computed from a cross-validation analysis demonstrated a high precision of the tributary-specific models in predicting temperature in unobserved years and of the global model in predicting temperatures in unobserved streams. Klamath River discharge has been monitored by four gages that broadly intersperse the 292 kilometers from the Iron Gate Dam to the Klamath River mouth. These gages defined the upstream and downstream margins of three reaches. Daily discharge of tributaries within a reach was estimated from 1980-2015 based on drainage-area proportionate allocations of the discharge differential between the upstream and downstream margin. Comparisons with measured discharge on Indian Creek, a moderate-sized tributary with naturally regulated flows, revealed that the estimates effectively approximated both the variability and magnitude of discharge.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930028012&hterms=brown+kenneth&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dbrown%2Bkenneth','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930028012&hterms=brown+kenneth&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dbrown%2Bkenneth"><span>Downward-deployed tethered satellite systems, measurement techniques, and instrumentation - A review</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Brown, Kenneth G.; Melfi, Leonard T., Jr.; Upchurch, Billy T.; Wood, George M., Jr.</p> <p>1992-01-01</p> <p>This paper describes a number of scheduled and proposed Shuttle-based downward-deployed tethered satellite systems (TSSs) the purpose of which is to determine the structure of the lower thermosphere and to measure the atmospheric and aerodynamic effects in the vicinity of the satellite, the aerothermodynamic effects on the satellite's surface, and the dynamics of the tether and its endmass, the satellite. The instruments for the downward-deployed tethered missions will include mass spectrometers and other density sensors, plasma instrumentation, optical spectrophotometers, magnetometers, and instrumentation to measure the effects on satellite surface (such as the surface temperature, heat transfer, and pressure; gas adsorption on surfaces, chemistry with other gas molecules and surface material, and desorption from the surface; and surface charging).</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70024740','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70024740"><span>Analysis of δ15N and δ18O to differentiate NO3− sources in runoff at two watersheds in the Catskill Mountains of New York</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Burns, Douglas A.; Kendall, Carol</p> <p>2002-01-01</p> <p>To quantify the movement of atmospheric nitrogen deposition through two forested watersheds in the Catskill Mountains of New York, dual‐isotope analysis (δ15N and δ18O) was used to differentiate NO3− derived from precipitation from NO3− derived by microbial nitrification and to quantify the contributions of these sources to NO3− in drainage waters. Samples of stream water, soil water, precipitation, snowmelt, and O‐horizon soil were collected during the March and April snowmelt period of 1994 and throughout an 18‐month period from August 1995 through February 1997. The mean δ18O‐NO3− value of precipitation was +50.5‰, whereas the mean values for stream water and soil water were +17.7‰ and +23.6‰, respectively. The mean δ15N‐NO3− of precipitation was −0.2‰, that of soil water was +1.4‰, and that of stream water was +2.3‰; these values showed greater overlap among the three different waters than did the δ18O‐NO3− values, indicating that δ15N‐NO3− was not as useful for source separation. Soil water δ18O‐NO3− values decreased, and δ15N‐NO3− values increased, from the O to the B and C horizons, but most of the differences among horizons were not statistically significant. Nitrate derived by nitrification in incubated soil samples had a wide range of δ15N‐NO3− values, from +1.5‰ to +16.1‰, whereas δ18O‐NO3− values ranged more narrowly, from +13.2‰ to +16.0‰. Values of δ18O‐NO3− indicated that NO3− in stream water is mainly derived from nitrification. Only during a high‐flow event that exceeded the annual flood was precipitation a major contributor to stream water NO3−. Values of δ18O‐NO3− and δ15N‐NO3− changed at differing rates as NO3− cycled through these watersheds because δ18O‐NO3− values change sharply through the incorporation of oxygen from ambient water and gas during nitrification, whereas δ15N‐NO3− values change only incrementally through fractionation during biocycling processes. The results of this study show that most NO3− is first cycled through the biota and nitrified before entering the stream.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000EnMan..26..563W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000EnMan..26..563W"><span>Stream Invertebrate Communities, Water Quality, and Land-Use Patterns in an Agricultural Drainage Basin of Northeastern Nebraska, USA</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Whiles, Matt R.; Brock, Brent L.; Franzen, Annette C.; Dinsmore, Steven C., II</p> <p>2000-11-01</p> <p>We used invertebrate bioassessment, habitat analysis, geographic information system analysis of land use, and water chemistry monitoring to evaluate tributaries of a degraded northeast Nebraska, USA, reservoir. Bimonthly invertebrate collections and monthly water chemistry samples were collected for two years on six stream reaches to identify sources contributing to reservoir degradation and test suitability of standard rapid bioassessment methods in this region. A composite biotic index composed of seven commonly used metrics was effective for distinguishing between differentially impacted sites and responded to a variety of disturbances. Individual metrics varied greatly in precision and ability to discriminate between relatively impacted and unimpacted stream reaches. A modified Hilsenhoff index showed the highest precision (reference site CV = 0.08) but was least effective at discriminating among sites. Percent dominance and the EPT (number of Ephemeroptera, Plecoptera, and Trichoptera taxa) metrics were most effective at discriminating between sites and exhibited intermediate precision. A trend of higher biotic integrity during summer was evident, indicating seasonal corrections should differ from other regions. Poor correlations were evident between water chemistry variables and bioassessment results. However, land-use factors, particularly within 18-m riparian zones, were correlated with bioassessment scores. For example, there was a strong negative correlation between percentage of rangeland in 18-m riparian zones and percentage of dominance in streams (r 2 = 0.90, P < 0.01). Results demonstrate that standard rapid bioassessment methods, with some modifications, are effective for use in this agricultural region of the Great Plains and that riparian land use may be the best predictor of stream biotic integrity.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19750043959&hterms=dependency&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Ddependency','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19750043959&hterms=dependency&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Ddependency"><span>Theoretical predictions of latitude dependencies in the solar wind</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Winge, C. R., Jr.; Coleman, P. J., Jr.</p> <p>1974-01-01</p> <p>Results are presented which were obtained with the Winge-Coleman model for theoretical predictions of latitudinal dependencies in the solar wind. A first-order expansion is described which allows analysis of first-order latitudinal variations in the coronal boundary conditions and results in a second-order partial differential equation for the perturbation stream function. Latitudinal dependencies are analytically separated out in the form of Legendre polynomials and their derivative, and are reduced to the solution of radial differential equations. This analysis is shown to supply an estimate of how large the coronal variation in latitude must be to produce an 11 km/sec/deg gradient in the radial velocity of the solar wind, assuming steady-state processes.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AIPC.1298..192G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AIPC.1298..192G"><span>Numerical Bifurcation Analysis of Delayed Recycle Stream in a Continuously Stirred Tank Reactor</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gangadhar, Nalwala Rohitbabu; Balasubramanian, Periyasamy</p> <p>2010-10-01</p> <p>In this paper, we present the stability analysis of delay differential equations which arise as a result of transportation lag in the CSTR-mechanical separator recycle system. A first order irreversible elementary reaction is considered to model the system and is governed by the delay differential equations. The DDE-BIFTOOL software package is used to analyze the stability of the delay system. The present analysis reveals that the system exhibits delay independent stability for isothermal operation of the CSTR. In the absence of delay, the system is dynamically unstable for non-isothermal operation of the CSTR, and as a result of delay, the system exhibits delay dependent stability.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/887149','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/887149"><span>The Streaming Potential Generated by Flow of Wet Steam in Capillary Tubes</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Marsden, S.S. Jr.; Tyran, Craig K.</p> <p>1986-01-21</p> <p>For a constant pressure differential, the flow of wet steam generated electric potentials which increased with time and did not reach equilibrium values. These potentials were found to increase to values greater than 100 volts. The reason for this kind of potential build-up behavior was the presence of tiny flowing water slugs which were interspersed with electrically nonconductive steam vapor slugs. The measured electric potential for wet steam increased with pressure differential, but the relationship was not linear. The increase in potential with pressure drop was attributed both to an increase in fluid flow rate and changes in the wetmore » steam quality.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5843354','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5843354"><span>Differential tissue growth and cell adhesion alone drive early tooth morphogenesis: An ex vivo and in silico study</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Savriama, Yoland; Jernvall, Jukka</p> <p>2018-01-01</p> <p>From gastrulation to late organogenesis animal development involves many genetic and bio-mechanical interactions between epithelial and mesenchymal tissues. Ectodermal organs, such as hairs, feathers and teeth are well studied examples of organs whose development is based on epithelial-mesenchymal interactions. These develop from a similar primordium through an epithelial folding and its interaction with the mesenchyme. Despite extensive knowledge on the molecular pathways involved, little is known about the role of bio-mechanical processes in the morphogenesis of these organs. We propose a simple computational model for the biomechanics of one such organ, the tooth, and contrast its predictions against cell-tracking experiments, mechanical relaxation experiments and the observed tooth shape changes over developmental time. We found that two biomechanical processes, differential tissue growth and differential cell adhesion, were enough, in the model, for the development of the 3D morphology of the early tooth germ. This was largely determined by the length and direction of growth of the cervical loops, lateral folds of the enamel epithelium. The formation of these cervical loops was found to require accelerated epithelial growth relative to other tissues and their direction of growth depended on specific differential adhesion between the three tooth tissues. These two processes and geometrical constraints in early tooth bud also explained the shape asymmetry between the lateral cervical loops and those forming in the anterior and posterior of the tooth. By performing mechanical perturbations ex vivo and in silico we inferred the distribution and direction of tensile stresses in the mesenchyme that restricted cervical loop lateral growth and forced them to grow downwards. Overall our study suggests detailed quantitative explanations for how bio-mechanical processes lead to specific morphological 3D changes over developmental time. PMID:29481561</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://www.hydrol-earth-syst-sci.net/19/1169/2015/hess-19-1169-2015.html','USGSPUBS'); return false;" href="http://www.hydrol-earth-syst-sci.net/19/1169/2015/hess-19-1169-2015.html"><span>Higher-order statistical moments and a procedure that detects potentially anomalous years as two alternative methods describing alterations in continuous environmental data</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Arismendi, Ivan; Johnson, Sherri L.; Dunham, Jason B.</p> <p>2015-01-01</p> <p>Statistics of central tendency and dispersion may not capture relevant or desired characteristics of the distribution of continuous phenomena and, thus, they may not adequately describe temporal patterns of change. Here, we present two methodological approaches that can help to identify temporal changes in environmental regimes. First, we use higher-order statistical moments (skewness and kurtosis) to examine potential changes of empirical distributions at decadal extents. Second, we adapt a statistical procedure combining a non-metric multidimensional scaling technique and higher density region plots to detect potentially anomalous years. We illustrate the use of these approaches by examining long-term stream temperature data from minimally and highly human-influenced streams. In particular, we contrast predictions about thermal regime responses to changing climates and human-related water uses. Using these methods, we effectively diagnose years with unusual thermal variability and patterns in variability through time, as well as spatial variability linked to regional and local factors that influence stream temperature. Our findings highlight the complexity of responses of thermal regimes of streams and reveal their differential vulnerability to climate warming and human-related water uses. The two approaches presented here can be applied with a variety of other continuous phenomena to address historical changes, extreme events, and their associated ecological responses.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29683652','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29683652"><span>Impacts of Glutaraldehyde on Microbial Community Structure and Degradation Potential in Streams Impacted by Hydraulic Fracturing.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Campa, Maria Fernanda; Techtmann, Stephen M; Gibson, Caleb M; Zhu, Xiaojuan; Patterson, Megan; Garcia de Matos Amaral, Amanda; Ulrich, Nikea; Campagna, Shawn R; Grant, Christopher J; Lamendella, Regina; Hazen, Terry C</p> <p>2018-05-15</p> <p>The environmental impacts of hydraulic fracturing, particularly those of surface spills in aquatic ecosystems, are not fully understood. The goals of this study were to (1) understand the effect of previous exposure to hydraulic fracturing fluids on aquatic microbial community structure and (2) examine the impacts exposure has on biodegradation potential of the biocide glutaraldehyde. Microcosms were constructed from hydraulic fracturing-impacted and nonhydraulic fracturing-impacted streamwater within the Marcellus shale region in Pennsylvania. Microcosms were amended with glutaraldehyde and incubated aerobically for 56 days. Microbial community adaptation to glutaraldehyde was monitored using 16S rRNA gene amplicon sequencing and quantification by qPCR. Abiotic and biotic glutaraldehyde degradation was measured using ultra-performance liquid chromatography--high resolution mass spectrometry and total organic carbon. It was found that nonhydraulic fracturing-impacted microcosms biodegraded glutaraldehyde faster than the hydraulic fracturing-impacted microcosms, showing a decrease in degradation potential after exposure to hydraulic fracturing activity. Hydraulic fracturing-impacted microcosms showed higher richness after glutaraldehyde exposure compared to unimpacted streams, indicating an increased tolerance to glutaraldehyde in hydraulic fracturing impacted streams. Beta diversity and differential abundance analysis of sequence count data showed different bacterial enrichment for hydraulic fracturing-impacted and nonhydraulic fracturing-impacted microcosms after glutaraldehyde addition. These findings demonstrated a lasting effect on microbial community structure and glutaraldehyde degradation potential in streams impacted by hydraulic fracturing operations.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28320947','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28320947"><span>Experimental evidence that parasites drive eco-evolutionary feedbacks.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Brunner, Franziska S; Anaya-Rojas, Jaime M; Matthews, Blake; Eizaguirre, Christophe</p> <p>2017-04-04</p> <p>Host resistance to parasites is a rapidly evolving trait that can influence how hosts modify ecosystems. Eco-evolutionary feedbacks may develop if the ecosystem effects of host resistance influence selection on subsequent host generations. In a mesocosm experiment, using a recently diverged (<100 generations) pair of lake and stream three-spined sticklebacks, we tested how experimental exposure to a common fish parasite ( Gyrodactylus spp.) affects interactions between hosts and their ecosystems in two environmental conditions (low and high nutrients). In both environments, we found that stream sticklebacks were more resistant to Gyrodactylus and had different gene expression profiles than lake sticklebacks. This differential infection led to contrasting effects of sticklebacks on a broad range of ecosystem properties, including zooplankton community structure and nutrient cycling. These ecosystem modifications affected the survival, body condition, and gene expression profiles of a subsequent fish generation. In particular, lake juvenile fish suffered increased mortality in ecosystems previously modified by lake adults, whereas stream fish showed decreased body condition in stream fish-modified ecosystems. Parasites reinforced selection against lake juveniles in lake fish-modified ecosystems, but only under oligotrophic conditions. Overall, our results highlight the overlapping timescales and the interplay of host-parasite and host-ecosystem interactions. We provide experimental evidence that parasites influence host-mediated effects on ecosystems and, thereby, change the likelihood and strength of eco-evolutionary feedbacks.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5389293','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5389293"><span>Experimental evidence that parasites drive eco-evolutionary feedbacks</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Brunner, Franziska S.; Anaya-Rojas, Jaime M.; Matthews, Blake; Eizaguirre, Christophe</p> <p>2017-01-01</p> <p>Host resistance to parasites is a rapidly evolving trait that can influence how hosts modify ecosystems. Eco-evolutionary feedbacks may develop if the ecosystem effects of host resistance influence selection on subsequent host generations. In a mesocosm experiment, using a recently diverged (<100 generations) pair of lake and stream three-spined sticklebacks, we tested how experimental exposure to a common fish parasite (Gyrodactylus spp.) affects interactions between hosts and their ecosystems in two environmental conditions (low and high nutrients). In both environments, we found that stream sticklebacks were more resistant to Gyrodactylus and had different gene expression profiles than lake sticklebacks. This differential infection led to contrasting effects of sticklebacks on a broad range of ecosystem properties, including zooplankton community structure and nutrient cycling. These ecosystem modifications affected the survival, body condition, and gene expression profiles of a subsequent fish generation. In particular, lake juvenile fish suffered increased mortality in ecosystems previously modified by lake adults, whereas stream fish showed decreased body condition in stream fish-modified ecosystems. Parasites reinforced selection against lake juveniles in lake fish-modified ecosystems, but only under oligotrophic conditions. Overall, our results highlight the overlapping timescales and the interplay of host–parasite and host–ecosystem interactions. We provide experimental evidence that parasites influence host-mediated effects on ecosystems and, thereby, change the likelihood and strength of eco-evolutionary feedbacks. PMID:28320947</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018E%26ES..141a2031S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018E%26ES..141a2031S"><span>Study of oil palm root architecture with variation of crop stage and soil type vulnerable to drought</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Safitri, Lisma; Suryanti, Sri; Kautsar, Valensi; Kurniawan, Agung; Santiabudi, Fajar</p> <p>2018-03-01</p> <p>Root arhitecture is affected by watertable level, characteristic of soil, organic matter and also the crop stages. Root architecture spread horizontally and vertically which each consist of primary, secondary, tertiary and quaternary downward root. The oil palm root observation with variation of crop stage and soil type showed that the root of oil palm plant year 2008 on spodosols soil spread along 650 cm horizontally from the trunk and penetrate downward in range of 9-28 cm vertically. Planted in the same type of soil, the root of oil palm plant year 2004 spread along 650 cm horizontally and reached to downward in a larger range from 3 to 57 cm vertically. As a comparison, the root architecture of oil palm on inceptisols soil established the range much greater vertically than the previous. The root of oil palm plant year 2008 spread along 640 cm horizontally and penetrate downward in range of 52-90 cm vertically. With the variation of crop age, the root of oil palm plant year 2003 spread along 650 cm horizontally and reached to downward in a larger range from 150 to 200 cm vertically. Based on this study, root architecture of oil palm was varied and need to be detailed. The precise root architecture of oil palm allows a better understanding on hydrological properties of oil palm root particularly which is cultivated on soil type vulnerable to drought. Referring to this root architecture, it was enable to develop the study on early drought detection of oil palm to optimise production and towards oil palm sustainability.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23542599','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23542599"><span>The foliar uptake and downward translocation of trichloroethylene and 1,2,3-trichlorobenzene in air-plant-water systems.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Su, Yuhong; Liang, Yongchao</p> <p>2013-05-15</p> <p>The foliar uptake and downward translocation of trichloroethylene (TCE) and 1,2,3-trichlorobenzene (TCB) in wheat, corn, and tomato seedlings were investigated following 2-48-h exposure of the plant shoots to vapor-contaminated air. The results showed that both TCE and TCB could be rapidly transported from air to plant rhizosphere solution through the foliar uptake and downward transport; the TCE and TCB concentrations in rhizosphere solutions increased with exposure time and external contaminant concentration. Among the three plant species studied, the TCE and TCB downward transport followed the order of wheat>tomato>corn. The transport efficiency of TCE by the three plants was far greater than that of TCB. With a 24-h uptake time, the amounts of TCE transported into the rhizosphere solution by wheat, tomato, and corn seedlings were 2.39 ± 0.42, 1.50 ± 0.22 and 1.45 ± 0.08 μg TCE per gram of fresh weight biomass, respectively, when the initial external TCE concentration was set at 12 mg l(-1). In a 48-h uptake experiment with corn seedlings, the TCE concentration in the rhizosphere solutions was lower in the TCE-TCB mixture system than in the single TCE system, whereas there was no significant difference in TCB concentration between the single TCB and TCE-TCB mixture systems at 48 h. The downward transport processes of TCE were inhibited, while those of TCB were enhanced in the mixed contaminant system within a 48-h uptake time. Copyright © 2013 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29071707','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29071707"><span>The influence of grasping habits and object orientation on motor planning in children and adults.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jovanovic, Bianca; Schwarzer, Gudrun</p> <p>2017-12-01</p> <p>We investigated the influence of habitual grasp strategies and object orientation on motor planning in 3-year-olds and 4- to 5-year-old children and adults. Participants were required to rotate different vertically oriented objects around 180°. Usually, adults perform this task by grasping objects with an awkward grip (thumb and index finger pointing downward) at the beginning of the movement, in order to finish it with a comfortable hand position. This pattern corresponds to the well-known end-state comfort effect (ESC) in grasp planning. The presented objects were associated with different habitual grasp orientations that either corresponded with the grasp direction required to reach end-state comfort (downward) or implied a contrary grasp orientation (upward). Additionally, they were presented either in their usual, canonical orientation (e.g., shovel with the blade oriented downward versus cup with its opening oriented upward) or upside down. As dependent variable we analyzed the number of grips conforming to the end-state comfort principle (ESC score) realized in each object type and orientation condition. The number of grips conforming to ESC strongly increased with age. In addition, the extent to which end-state comfort was considered was influenced by the actual orientation of the objects' functional parts. Thus, in all age-groups the ESC score was highest when the functional parts of the objects were oriented downward (shovel presented canonically with blade pointing downward, cup presented upside down) and corresponded to the hand orientation needed to realize ESC. © 2017 Wiley Periodicals, Inc.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760003450','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760003450"><span>Photointerpretation of Skylab photography</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mcmurtry, G. J.; Petersen, G. W. (Principal Investigator); Weeden, H. W.; Kleeman, C.; Daelhausen, S.; Hesler, G.</p> <p>1975-01-01</p> <p>The author has identified the following significant results. In terms of film grain texture and object definition, the S190B color positive film is distinctly superior to the S190A films, when both are compared in the 9 x 9 inch format. Within the six S190A films, the panchromatic black and white films are superior to the infrared black and white, and the color positive film is superior to the color infrared. Minimum relief differences on the order of 500 to 100 feet could be detected by stereoscopic study, however, it is not possible to determine to what extent vegetation and cultural practices assist in such delineations. Water and wind gaps through major ridges were easily seen. Streams of third order and larger were clearly visible and easy to trace; second order streams were not identified with consistency. Differences in color, tone, and textural patterns rarely supplied clues for differentiating soils or bedrock. The separation of naturally forested areas from areas of cultivation and pasture was effective and a valuable clue to the underlying geology. Suburban and industrial developments were clearly differentiated from urban areas and surrounding agricultural fields. Soil associations could be identified on a regional basis, but no sharp boundary could be drawn separating soil associations.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880008713','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880008713"><span>Evaluation of surface energy and radiation balance systems on the Konza Prairie</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fritschen, Leo J.</p> <p>1987-01-01</p> <p>Four Surface Energy and Radiation Balance Systems (SERBS) were installed and operated for two weeks in Kansas during July of 1986. Surface energy and radiation balances were investigated on six sites on the Konza Prairie about 3 km south of Manhattan, Kansas. Measurements were made to allow the computation of these radiation components: total solar and diffuse radiation, reflected solar radiation, net radiation, and longwave radiation upward and downward. Measurements were made to allow the computation of the sensible and latent heat fluxes by the Bowen ratio method using differential psychrometers on automatic exchange mechanisms. The report includes a description of the experimental sites, data acquisition systems and sensors, data acquisitions system operating instructions, and software used for data acquisition and analysis. In addition, data listings and plots of the energy balance components for all days and systems are given.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://ufdc.ufl.edu/UF00001208/00001/pdf?search=hydrologic+%3dconditions+%3dsherwood','USGSPUBS'); return false;" href="http://ufdc.ufl.edu/UF00001208/00001/pdf?search=hydrologic+%3dconditions+%3dsherwood"><span>Hydrologic conditions: Dade County, Florida</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Kohout, Francis Anthony; Klein, Howard; Sherwood, C.B.; Leach, Stanley D.</p> <p>1964-01-01</p> <p>Thin layers of dense limestone of low permeability that occur near the top of the Biscayne aquifer in the vicinity of the north end of Levee 30 in Dade County, Florida are of hydrologic importance because they retard the downward infiltration of ponded water in Conservation Area No. 3. This retarding effect frequently results in high head differentials across the levee. Tests made in a small area adjacent to Levee 30 indicate that the coefficient of transmissibility of the aquifer is 3,600,000 gpd (gallons per day) per foot, and the coefficient of vertical permeability of the dense limestones is 13 gpd per square foot. If ground-water flow beneath the levee is laminar, the total inflow to the Levee 30 Canal from Conservation Area No. 3 will be about 350 mgd (million gallons per day), or 540 cfs (cubic feet per second), per mile length of levee when the head difference across the levee is 10 feet.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040090128&hterms=ZEA+MAYS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DZEA%2BMAYS','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040090128&hterms=ZEA+MAYS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DZEA%2BMAYS"><span>A gradient of endogenous calcium forms in mucilage of graviresponding roots of Zea mays</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Moore, R.; Fondren, W. M.</p> <p>1988-01-01</p> <p>Agar blocks that contacted the upper sides of tips of horizontally-oriented roots of Zea mays contain significantly less calcium (Ca) than blocks that contacted the lower sides of such roots. This gravity-induced gradient of Ca forms prior to the onset of gravicurvature, and does not form across tips of vertically-oriented roots or roots of agravitropic mutants. These results indicate that (1) Ca can be collected from mucilage of graviresponding roots, (2) gravity induces a downward movement of endogenous Ca in mucilage overlying the root tip, (3) this gravity-induced gradient of Ca does not form across tips of agravitropic roots, and (4) formation of a Ca gradient is not a consequence of gravicurvature. These results are consistent with gravity-induced movement of Ca being a trigger for subsequent redistribution of growth effectors (e.g. auxin) that induce differential growth and gravicurvature.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/3234571','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/3234571"><span>Changes in cohort wealth over a generation.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>David, M H; Menchik, P L</p> <p>1988-08-01</p> <p>Empirical computation of expected wealth is hampered by two problems: mortality risks vary in the population and over time; and observation of net estates for most cohorts is truncated, as some individuals in a cohort survive the calendar date on which observation is terminated. These two problems are solved in estimating cohort wealth for a sample of Wisconsin taxpayers. Hazard rate models of differential occupational mortality risks were estimated from the occupational information on the tax records. Values of net estate are simulated for individuals in each birth cohort who survived. Survivors have characteristics that imply greater wealth holdings than the deceased in every birth year covered by the study (1890-1924). Because of this, estimates of wealth-age relationships produced by the estate multiplier method for any given year will have a serious downward bias. Longitudinal data imply that dissaving does not occur after age 65.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23386960','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23386960"><span>A theory of biological relativity: no privileged level of causation.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Noble, Denis</p> <p>2012-02-06</p> <p>Must higher level biological processes always be derivable from lower level data and mechanisms, as assumed by the idea that an organism is completely defined by its genome? Or are higher level properties necessarily also causes of lower level behaviour, involving actions and interactions both ways? This article uses modelling of the heart, and its experimental basis, to show that downward causation is necessary and that this form of causation can be represented as the influences of initial and boundary conditions on the solutions of the differential equations used to represent the lower level processes. These insights are then generalized. A priori, there is no privileged level of causation. The relations between this form of 'biological relativity' and forms of relativity in physics are discussed. Biological relativity can be seen as an extension of the relativity principle by avoiding the assumption that there is a privileged scale at which biological functions are determined.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3262309','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3262309"><span>A theory of biological relativity: no privileged level of causation</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Noble, Denis</p> <p>2012-01-01</p> <p>Must higher level biological processes always be derivable from lower level data and mechanisms, as assumed by the idea that an organism is completely defined by its genome? Or are higher level properties necessarily also causes of lower level behaviour, involving actions and interactions both ways? This article uses modelling of the heart, and its experimental basis, to show that downward causation is necessary and that this form of causation can be represented as the influences of initial and boundary conditions on the solutions of the differential equations used to represent the lower level processes. These insights are then generalized. A priori, there is no privileged level of causation. The relations between this form of ‘biological relativity’ and forms of relativity in physics are discussed. Biological relativity can be seen as an extension of the relativity principle by avoiding the assumption that there is a privileged scale at which biological functions are determined. PMID:23386960</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/21045894-interaction-between-single-molecules-mac-icam-living-cells-atomic-force-microscopy-study','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21045894-interaction-between-single-molecules-mac-icam-living-cells-atomic-force-microscopy-study"><span></span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Yang Huayan; Yu Junping; Fu Guo</p> <p></p> <p>The interaction between integrin macrophage differentiation antigen associated with complement three receptor function (Mac-1) and intercellular adhesion molecule-1 (ICAM-1), which is controlled tightly by the ligand-binding activity of Mac-1, is central to the regulation of neutrophil adhesion in host defense. Several 'inside-out' signals and extracellular metal ions or antibodies have been found to activate Mac-1, resulting in an increased adhesiveness of Mac-1 to its ligands. However, the molecular basis for Mac-1 activation is not well understood yet. In this work, we have carried out a single-molecule study of Mac-1/ICAM-1 interaction force in living cells by atomic force microscopy (AFM). Ourmore » results showed that the binding probability and adhesion force of Mac-1 with ICAM-1 increased upon Mac-1 activation. Moreover, by comparing the dynamic force spectra of different Mac-1 mutants, we expected that Mac-1 activation is governed by the downward movement of its {alpha}7 helix.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/55470','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/55470"><span>Partial harvesting of hardwood sawtimber in Kentucky and Tennessee, 2002–2014</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Thomas J. Brandeis</p> <p>2017-01-01</p> <p>Partial harvesting is the predominant but not exclusive cutting treatment applied to the hardwood forests of Kentucky and Tennessee. Hardwood harvest in Kentucky showed a slight downward trend from 2006 to 2014, with most of the volume harvested in partial logging operations. Tennessee did not show this same downward trend, and the amount of hardwood volume harvested...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://eric.ed.gov/?q=color+AND+motivation&pg=5&id=EJ1000807','ERIC'); return false;" href="https://eric.ed.gov/?q=color+AND+motivation&pg=5&id=EJ1000807"><span>Effect of a Surprising Downward Shift in Reinforcer Value on Stimulus Over-Selectivity in a Simultaneous Discrimination Procedure</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Reynolds, Gemma; Reed, Phil</p> <p>2013-01-01</p> <p>Stimulus over-selectivity refers to the phenomenon whereby behavior is controlled by a subset of elements in the environment at the expense of other equally salient aspects of the environment. The experiments explored whether this cue interference effect was reduced following a surprising downward shift in reinforcer value. Experiment 1 revealed…</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGeoS...8...14S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGeoS...8...14S"><span>A numerical test of the topographic bias</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sjöberg, L. E.; Joud, M. S. S.</p> <p>2018-02-01</p> <p>In 1962 A. Bjerhammar introduced the method of analytical continuation in physical geodesy, implying that surface gravity anomalies are downward continued into the topographic masses down to an internal sphere (the Bjerhammar sphere). The method also includes analytical upward continuation of the potential to the surface of the Earth to obtain the quasigeoid. One can show that also the common remove-compute-restore technique for geoid determination includes an analytical continuation as long as the complete density distribution of the topography is not known. The analytical continuation implies that the downward continued gravity anomaly and/or potential are/is in error by the so-called topographic bias, which was postulated by a simple formula of L E Sjöberg in 2007. Here we will numerically test the postulated formula by comparing it with the bias obtained by analytical downward continuation of the external potential of a homogeneous ellipsoid to an inner sphere. The result shows that the postulated formula holds: At the equator of the ellipsoid, where the external potential is downward continued 21 km, the computed and postulated topographic biases agree to less than a millimetre (when the potential is scaled to the unit of metre).</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGRA..123.1618B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGRA..123.1618B"><span>On the Nocturnal Downward and Westward Equatorial Ionospheric Plasma Drifts During the 17 March 2015 Geomagnetic Storm</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bagiya, Mala S.; Vichare, Geeta; Sinha, A. K.; Sripathi, S.</p> <p>2018-02-01</p> <p>During quiet period, the nocturnal equatorial ionospheric plasma drifts eastward in the zonal direction and downward in the vertical direction. This quiet time drift pattern could be understood through dynamo processes in the nighttime equatorial ionosphere. The present case study reports the nocturnal simultaneous occurrence of the vertically downward and zonally westward plasma drifts over the Indian latitudes during the geomagnetic storm of 17 March 2015. After 17:00 UT ( 22:10 local time), the vertical plasma drift became downward and coincided with the westward zonal drift, a rarely observed feature of low latitude plasma drifts. The vertical drift turned upward after 18:00 UT, while the zonal drift became eastward. We mainly emphasize here the distinct bipolar type variations of vertical and zonal plasma drifts observed around 18:00 UT. We explain the vertical plasma drift in terms of the competing effects between the storm time prompt penetration and disturbance dynamo electric fields. Whereas, the westward drift is attributed to the storm time local electrodynamical changes mainly through the disturbance dynamo field in addition to the vertical Pedersen current arising from the spatial (longitudinal) gradient of the field aligned Pedersen conductivity.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/1054990-long-term-data-reveal-patterns-controls-stream-water-chemistry-forested-stream-walker-branch-tennessee','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1054990-long-term-data-reveal-patterns-controls-stream-water-chemistry-forested-stream-walker-branch-tennessee"><span>Long-Term Data Reveal Patterns and Controls on Stream Water Chemistry in a Forested Stream: Walker Branch, Tennessee</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Lutz, Brian D; Mulholland, Patrick J; Bernhardt, Emily</p> <p>2012-01-01</p> <p>We present 20 years of weekly stream water chemistry, hydrology, and climate data for the Walker Branch watershed in eastern Tennessee, USA. Since 1989, the watershed has experienced a similar to 1.08 degrees C increase in mean annual temperature, a similar to 20% decline in precipitation, and a similar to 30% increase in forest evapotranspiration rates. As a result, stream runoff has declined by similar to 34%. We evaluate long-term trends in stream water concentrations and fluxes for nine solutes and use wet deposition data to calculate approximate watershed input-output budgets. Dissolved constituents were classified as geochemical solutes (Ca2+, Mg2+,more » and SO42-) or nutrients (NH4+, NO3-, soluble reactive phosphorus [SRP], total soluble nitrogen [TSN], total soluble phosphorus [TSP], and dissolved organic carbon [DOC]). Geochemical solutes are predominantly controlled by discharge, and the long-term changes in catchment hydrology have led to significant trends in the concentrations and fluxes of these solutes. Further, the trends in geochemical solute concentrations indicate shifting soil flowpath contributions to streamflow generation through time, with deep groundwater having a greater proportional contribution in recent years. Despite dramatic changes in watershed runoff, there were no trends in inorganic nutrient concentrations (NH4+, NO3-, and SRP). While most nutrients entering the watershed are retained, stream fluxes of nutrient solutes have declined significantly as a result of decreasing runoff. Nutrient concentrations in the stream exhibit large seasonality controlled by in-stream biological uptake. Stream benthic communities are sensitive to hydrologic disturbance, and changes in the frequency or intensity of storm events through time can affect nutrient fluxes. Stream NO3- concentrations are also sensitive to drought, with concentrations decreasing (increasing) if conditions during the three years prior to the time of sampling were drier (wetter) than the long-term mean. Future changes in the incidence of storm events, as well as the number and duration of droughts, have the potential to significantly alter watershed nutrient losses. Our analysis indicates that changing climates can differentially affect watershed element cycles either through changes in biogeochemical process rates or through changes in catchment hydrology. Furthermore, climate change can include both long-term trending in mean climate variables, as well as changes in the frequency and intensity of storms and droughts, with each of these types of change having distinct effects on the biological and geochemical processes governing different solutes.« less</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70031287','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70031287"><span>Escape tectonics and the extrusion of Alaska: Past, present, and future</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Redfield, T.F.; Scholl, D. W.; Fitzgerald, P.G.; Beck, M.E.</p> <p>2007-01-01</p> <p>The North Pacific Rim is a tectonically active plate boundary zone parts of which may be characterized as a laterally moving orogenic stream. Crustal blocks are transported along large-magnitude strike-slip faults in western Canada and central Alaska toward the Aleutian-Bering Sea subduction zones. Throughout much of the Cenozoic, at and west of its Alaskan nexus, the North Pacific Rim orogenic Stream (NPRS) has undergone tectonic escape. During transport, relatively rigid blocks acquired paleomagnetic rotations and fault-juxtaposed boundaries while flowing differentially through the system, from their original point of accretion and entrainment toward the free face defined by the Aleutian-Bering Sea subduction zones. Built upon classical terrane tectonics, the NPRS model provides a new framework with which to view the mobilistic nature of the western North American plate boundary zone. ?? 2007 The Geological Society of America.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25310518','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25310518"><span>Nature inspires sensors to do more with less.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mulvaney, Shawn P; Sheehan, Paul E</p> <p>2014-10-28</p> <p>The world is filled with widely varying chemical, physical, and biological stimuli. Over millennia, organisms have refined their senses to cope with these diverse stimuli, becoming virtuosos in differentiating closely related antigens, handling extremes in concentration, resetting the spent sensing mechanisms, and processing the multiple data streams being generated. Nature successfully deals with both repeating and new stimuli, demonstrating great adaptability when confronted with the latter. Interestingly, nature accomplishes these feats using a fairly simple toolbox. The sensors community continues to draw inspiration from nature's example: just look at the antibodies used as biosensor capture agents or the neural networks that process multivariate data streams. Indeed, many successful sensors have been built by simply mimicking natural systems. However, some of the most exciting breakthroughs occur when the community moves beyond mimicking nature and learns to use nature's tools in innovative ways.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/20170002559','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20170002559"><span>The Anomalous Change in the QBO in 2015-2016</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Newman, P. A.; Coy, L.; Lait, L. R.</p> <p>2016-01-01</p> <p>The quasi-biennial oscillation (QBO) is a tropical lower stratospheric, downward propagating zonal wind variation, with an average period of approximately 28 months. The QBO has been constantly documented since 1953. Here we describe the evolution of the QBO during the Northern Hemisphere winter of 2015-16 using radiosonde observations and meteorological reanalyses. Normally, the QBO would show a steady downward propagation of the westerly phase. In 2015-16, there was an anomalous upward displacement of this westerly phase from approximately30 hPa to 15 hPa. These westerlies impinge on, or “cut-off” the normal downward propagation of the easterly phase. In addition, easterly winds develop at 40 hPa. Comparisons to tropical wind statistics for the 1953-present record demonstrate that this 2015-16 QBO disruption is unprecedented.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940026597','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940026597"><span>Convection and electrodynamic signatures in the vicinity of a Sun-aligned arc: Results from the Polar Acceleration Regions and Convection Study (Polar ARCS)</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Weiss, L. A.; Weber, E. J.; Reiff, P. H.; Sharber, J. R.; Winningham, J. D.; Primdahl, F.; Mikkelsen, I. S.; Seifring, C.; Wescott, Eugene M.</p> <p>1994-01-01</p> <p>An experimental campaign designed to study high-latitude auroral arcs was conducted in Sondre Stromfjord, Greenland, on February 26, 1987. The Polar Acceleration Regions and Convection Study (Polar ARCS) consisted of a coordinated set of ground-based, airborne, and sounding rocket measurements of a weak, sun-aligned arc system within the duskside polar cap. A rocket-borne barium release experiment, two DMSP satellite overflights, all-sky photography, and incoherent scatter radar measurements provided information on the large-scale plasma convection over the polar cap region while a second rocket instrumented with a DC magnetometer, Langmuir and electric field probes, and an electron spectrometer provided measurements of small-scale electrodynamics. The large-scale data indicate that small, sun-aligned precipitation events formed within a region of antisunward convection between the duskside auroral oval and a large sun-aligned arc further poleward. This convection signature, used to assess the relationship of the sun-aligned arc to the large-scale magnetospheric configuration, is found to be consistent with either a model in which the arc formed on open field lines on the dusk side of a bifurcated polar cap or on closed field lines threading an expanded low-latitude boundary layer, but not a model in which the polar cap arc field lines map to an expanded plasma sheet. The antisunward convection signature may also be explained by a model in which the polar cap arc formed on long field lines recently reconnected through a highly skewed plasma sheet. The small-scale measurements indicate the rocket passed through three narrow (less than 20 km) regions of low-energy (less than 100 eV) electron precipitation in which the electric and magnetic field perturbations were well correlated. These precipitation events are shown to be associated with regions of downward Poynting flux and small-scale upward and downward field-aligned currents of 1-2 micro-A/sq m. The paired field-aligned currents are associated with velocity shears (higher and lower speed streams) embedded in the region of antisunward flow.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.B23I..02S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.B23I..02S"><span>Nitrogen trends in rivers of the conterminous U.S. in the context of land use and sources</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stets, E.; Sprague, L. A.</p> <p>2017-12-01</p> <p>Tremendous efforts have been undertaken to improve the quality of water throughout the United States over the past several decades. The goal of decreasing nitrogen concentrations and fluxes from U.S. rivers has had mixed success and the results are often difficult to quantify. The U.S. Geological Survey has undertaken a study to describe trends in water quality at hundreds of river and stream locations in the conterminous U.S. using a broad data set from national, state, local, and tribal entities. This study represents the largest and most comprehensive analysis of trends in water quality in the U.S. to date. During the period 1992-2012, nitrate (NO3) decreased at 132 sites and increased at 88 sites. Total nitrogen (TN) decreased at 91 sites and increased at 55 sites. The median trend for both NO3 and TN was slightly downward, at -0.04 and -0.11 mg N L-1, respectively. For both NO3 and TN, downward trends were more common in agricultural and urban sites while upward trends were more common at undeveloped sites. Decreases in TN were largest in rivers for which NO3 was a large proportion of TN, which is indicative of significant anthropogenic nitrogen inputs. Across all sites and land use types, trends in TN were highly correlated with trends in NO3, suggesting that changes in NO3 have been a large contributor to TN trends. While overall the largest decreases in NO3 and TN primarily occurred in heavily agricultural areas, decreases were also common in watersheds with higher percentage urban development. Likewise, the largest decreases in NO3 deposition were found in more developed watersheds, suggesting that decreasing atmospheric deposition may be related to NO3 trends at the more developed locations. Despite these improvements, fluxes of nitrogen to the coastal ocean have been largely static over the past several decades, underscoring the continuing need for nutrient management in many parts of the conterminous U.S.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JCAP...12..039G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JCAP...12..039G"><span>Unified halo-independent formalism from convex hulls for direct dark matter searches</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gelmini, Graciela B.; Huh, Ji-Haeng; Witte, Samuel J.</p> <p>2017-12-01</p> <p>Using the Fenchel-Eggleston theorem for convex hulls (an extension of the Caratheodory theorem), we prove that any likelihood can be maximized by either a dark matter 1- speed distribution F(v) in Earth's frame or 2- Galactic velocity distribution fgal(vec u), consisting of a sum of delta functions. The former case applies only to time-averaged rate measurements and the maximum number of delta functions is (Script N‑1), where Script N is the total number of data entries. The second case applies to any harmonic expansion coefficient of the time-dependent rate and the maximum number of terms is Script N. Using time-averaged rates, the aforementioned form of F(v) results in a piecewise constant unmodulated halo function tilde eta0BF(vmin) (which is an integral of the speed distribution) with at most (Script N-1) downward steps. The authors had previously proven this result for likelihoods comprised of at least one extended likelihood, and found the best-fit halo function to be unique. This uniqueness, however, cannot be guaranteed in the more general analysis applied to arbitrary likelihoods. Thus we introduce a method for determining whether there exists a unique best-fit halo function, and provide a procedure for constructing either a pointwise confidence band, if the best-fit halo function is unique, or a degeneracy band, if it is not. Using measurements of modulation amplitudes, the aforementioned form of fgal(vec u), which is a sum of Galactic streams, yields a periodic time-dependent halo function tilde etaBF(vmin, t) which at any fixed time is a piecewise constant function of vmin with at most Script N downward steps. In this case, we explain how to construct pointwise confidence and degeneracy bands from the time-averaged halo function. Finally, we show that requiring an isotropic Galactic velocity distribution leads to a Galactic speed distribution F(u) that is once again a sum of delta functions, and produces a time-dependent tilde etaBF(vmin, t) function (and a time-averaged tilde eta0BF(vmin)) that is piecewise linear, differing significantly from best-fit halo functions obtained without the assumption of isotropy.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A31E2238C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A31E2238C"><span>The influence of Cloud Longwave Scattering together with a state-of-the-art Ice Longwave Optical Parameterization in Climate Model Simulations</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Y. H.; Kuo, C. P.; Huang, X.; Yang, P.</p> <p>2017-12-01</p> <p>Clouds play an important role in the Earth's radiation budget, and thus realistic and comprehensive treatments of cloud optical properties and cloud-sky radiative transfer are crucial for simulating weather and climate. However, most GCMs neglect LW scattering effects by clouds and tend to use inconsistent cloud SW and LW optical parameterizations. Recently, co-authors of this study have developed a new LW optical properties parameterization for ice clouds, which is based on ice cloud particle statistics from MODIS measurements and state-of-the-art scattering calculation. A two-stream multiple-scattering scheme has also been implemented into the RRTMG_LW, a widely used longwave radiation scheme by climate modeling centers. This study is to integrate both the new LW cloud-radiation scheme for ice clouds and the modified RRTMG_LW with scattering capability into the NCAR CESM to improve the cloud longwave radiation treatment. A number of single column model (SCM) simulations using the observation from the ARM SGP site on July 18 to August 4 in 1995 are carried out to assess the impact of new LW optical properties of clouds and scattering-enabled radiation scheme on simulated radiation budget and cloud radiative effect (CRE). The SCM simulation allows interaction between cloud and radiation schemes with other parameterizations, but the large-scale forcing is prescribed or nudged. Comparing to the results from the SCM of the standard CESM, the new ice cloud optical properties alone leads to an increase of LW CRE by 26.85 W m-2 in average, as well as an increase of the downward LW flux at surface by 6.48 W m-2. Enabling LW cloud scattering further increases the LW CRE by another 3.57 W m-2 and the downward LW flux at the surface by 0.2 W m-2. The change of LW CRE is mainly due to an increase of cloud top height, which enhances the LW CRE. A long-term simulation of CESM will be carried out to further understand the impact of such changes on simulated climates.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.usgs.gov/of/ofr01-396/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/ofr01-396/"><span>Chinese mitten crab surveys of San Joaquin River basin and Suisun Marsh, California, 2000</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>May, Jason T.; Brown, Larry R.</p> <p>2001-01-01</p> <p>Juvenile Chinese mitten crabs (Eriocheir sinensis) are known to use both brackish and freshwater habitats as rearing areas. The objectives of this study were to examine the habitat use and potential effects of mitten crabs in the freshwater habitats of the San Joaquin River drainage up-stream of the Sacramento-San Joaquin Delta. After several unsuccessful attempts to catch or observe mitten crabs by trapping, electrofishing, and visual observations, the study was redirected to determine the presence of crabs in the San Joaquin River (in the vicinity of Mossdale) and Suisun Marsh. Monthly surveys using baited traps in the San Joaquin River were done from June through November 2000 and in the Suisun Marsh from August through October 2000. No mitten crabs were caught in the San Joaquin River Basin and only one mitten crab was caught in Suisun Marsh. Surveys were conducted at 92 locations in the San Joaquin River Basin by deploying 352 traps for 10,752 hours of trapping effort; in Suisun Marsh, 34 locations were investigated by deploying 150 traps for 3,600 hours of trapping effort. The baited traps captured a variety of organisms, including catfishes (Ictularidae), yellowfin gobies (Acantho-gobius flavimanus), and crayfish (Decapoda). It is unclear whether the failure to capture mitten crabs in the San Joaquin River Basin and Suisun Marsh was due to ineffective trapping methods, or repre-sents a general downward trend in populations of juvenile mitten crabs in these potential rearing areas or a temporary decline related to year-class strength. Available data (since 1998) on the number of mitten crabs entrained at federal and state fish salvage facilities indicate a downward trend in the number of crabs, which may indicate a declining trend in use of the San Joaquin River Basin by juvenile mitten crabs. Continued monitoring for juvenile Chinese mitten crabs in brackish and freshwater portions of the Sacramento-San Joaquin River Basins is needed to better assess the potential population variability of this relatively new invasive species and the possible management strategies.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22922320','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22922320"><span>Influence of reproductive tract obstruction on expression of epididymal proteins and their restoration after patency.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Bing-Kun; Wang, Xiang; Liu, Chun-Xiao; Zheng, Shao-Bo; Li, Hu-Lin; Li, Li-Ping; Xu, A-Bai</p> <p>2013-01-01</p> <p>Vasectomy is a simple and reliable method of male contraception. A growing number of men after vasectomy request vasectomy reversal due to various reasons. The pregnancy rate is lower than the patency rate after vasovasostomy and the pregnancy rate is time dependent. In this study, we evaluated the influence of reproductive tract obstruction on expression of epididymal proteins and their restoration after patency. Adult male Wistar rats were studied 30, 60 and 120 days after vasectomy, 30 days after vasovasostomy or after sham operations. Two-dimensional gel electrophoresis, mass-spectrometric technique, multidatabase search, Western blotting and real-time PCR were used to analyze the expression regulation of epididymal proteins. Total integrated intensity and total spot area of autoradiograms showed a consistent downward trend with time after obstruction, and this trend remained after patency. The intensity of the autoradiographic spots in three patency groups showed three trends: a downward trend, similar intensity and an upward trend compared with the correspondent obstruction group, respectively. Further verified experiments on human epididymis 2 (HE2), fertilization antigen-1 (FA-1), clusterin and PH20 demonstrated that compared with the correspondent obstruction group, the translation levels of HE2 and the mRNA transcription levels of HE2 showed an upward trend in patency groups, especially in the groups of obstruction for 60 days where the expression levels of HE2 were significantly upregulated after patency (P<0.05). Reproductive tract obstruction provokes a disregulation of gene expression in the epididymis and this disregulation remained after patency. Successful reversal may recover some proteins and the recovery is time dependent. Obstruction differentially alters mRNA transcription of different proteins and the content of proteins seemed to be easier to be influenced than the gene transcription.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.fs.usda.gov/treesearch/pubs/37270','TREESEARCH'); return false;" href="https://www.fs.usda.gov/treesearch/pubs/37270"><span>Three-dimensional canopy fuel loading predicted using upward and downward sensing LiDAR systems</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.fs.usda.gov/treesearch/">Treesearch</a></p> <p>Nicholas S. Skowronski; Kenneth L. Clark; Matthew Duveneck; John. Hom</p> <p>2011-01-01</p> <p>We calibrated upward sensing profiling and downward sensing scanning LiDAR systems to estimates of canopy fuel loading developed from field plots and allometric equations, and then used the LiDAR datasets to predict canopy bulk density (CBD) and crown fuel weight (CFW) in wildfire prone stands in the New Jersey Pinelands. LiDAR-derived height profiles were also...</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.osti.gov/biblio/22227906-measurements-eigenfunction-reversed-shear-alfven-eigenmodes-sweep-downward-frequency','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22227906-measurements-eigenfunction-reversed-shear-alfven-eigenmodes-sweep-downward-frequency"><span>Measurements of the eigenfunction of reversed shear Alfvén eigenmodes that sweep downward in frequency</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Heidbrink, W. W.; Austin, M. E.; Spong, D. A.</p> <p>2013-08-15</p> <p>Reversed shear Alfvén eigenmodes (RSAEs) usually sweep upward in frequency when the minimum value of the safety factor q{sub min} decreases in time. On rare occasions, RSAEs sweep downward prior to the upward sweep. Electron cyclotron emission measurements show that the radial eigenfunction during the downsweeping phase is similar to the eigenfunction of normal, upsweeping RSAEs.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21088264','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21088264"><span>The differential association between education and infant mortality by nativity status of Chinese American mothers: a life-course perspective.</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Qing; Keith, Louis G</p> <p>2011-05-01</p> <p>Integrating evidence from demography and epidemiology, we investigated whether the association between maternal achieved status (education) and infant mortality differed by maternal place of origin (nativity) over the life course of Chinese Americans. We conducted a population-based cohort study of singleton live births to US-resident Chinese American mothers using National Center for Health Statistics 1995 to 2000 linked live birth and infant death cohort files. We categorized mothers by nativity (US born [n = 15 040] or foreign born [n = 150 620]) and education (≥ 16 years, 13-15 years, or ≤ 12 years), forming 6 life-course trajectories. We performed Cox proportional hazards regressions of infant mortality. We found significant nativity-by-education interaction via stratified analyses and testing interaction terms (P < .03) and substantial differentials in infant mortality across divergent maternal life-course trajectories. Low education was more detrimental for the US born, with the highest risk among US-born mothers with 12 years or less of education (adjusted hazard ratio = 2.39; 95% confidence interval = 1.33, 4.27). Maternal nativity and education synergistically affect infant mortality among Chinese Americans, suggesting the importance of searching for potential mechanisms over the maternal life course and targeting identified high-risk groups and potential downward mobility.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMEP53B1003M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMEP53B1003M"><span>Utilizing Time Domain Reflectometry on monitoring bedload in a mountain stream</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Miyata, S.; Fujita, M.</p> <p>2015-12-01</p> <p>Understanding bedload transport processes in steep mountain streams is essential for disaster mitigation as well as predicting reservoir capacity and restoration of river ecosystem. Despite various monitoring methods proposed previously, precise bedload monitoring in steep streams still remains difficulty. This study aimed to develop a bedload monitoring system by continuous measurement of thickness and porosity of sediment under water that can be applicable to retention basins and pools in steep streams. When a probe of TDR (Time Domain Reflectometry) measurement system is inserted as to penetrate two adjacent layers with different dielectric constants, analysis of TDR waveform enables us to determine position of the layer boundary and ratio of materials in the layer. Methodology of analyzing observed TDR waveforms were established based on results of a series of column experiment, in which a single TDR probe with length of 40 cm was installed in a column filled with water and, then, sand was supplied gradually. Flume experiment was performed to apply the TDR system on monitoring sediment volume under flowing water conditions. Eight probes with lengths of 27 cm were distributed equally in a model retention basin (i.e., container), into which water and bedload were flowed from a connected flume. The model retention basin was weighed by a load cell and the sediment volume was calculated. A semi-automatic waveform analysis was developed to calculate continuously thicknesses and porosities of the sediment at the eight probes. Relative errors of sediment volume and bedload (=time differential of the volume) were 13 % at maximum, suggesting that the TDR system proposed in this study with multiple probes is applicable to bedload monitoring in retention basins of steep streams. Combination of this system and other indirect bedload monitoring method (e.g., geophone) potentially make a breakthrough for understanding sediment transport processes in steep mountain streams.</p> </li> <li> <p><a target="_blank" rel="noopener noreferrer" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70031091','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70031091"><span>Mapping stream habitats with a global positioning system: Accuracy, precision, and comparison with traditional methods</span></a></p> <p><a target="_blank" rel="noopener noreferrer" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Dauwalter, D.C.; Fisher, W.L.; Belt, K.C.</p> <p>2006-01-01</p> <p>We tested the precision and accuracy of the Trimble GeoXT??? global positioning system (GPS) handheld receiver on point and area features and compared estimates of stream habitat dimensions (e.g., lengths and areas of riffles and pools) that were made in three different Oklahoma streams using the GPS receiver and a tape measure. The precision of differentially corrected GPS (DGPS) points was not affected by the number of GPS position fixes (i.e., geographic location estimates) averaged per DGPS point. Horizontal error of points ranged from 0.03 to 2.77 m and did not differ with the number of position fixes per point. The error of area measurements ranged from 0.1% to 110.1% but decreased as the area increased. Again, error was independent of the number of position fixes averaged per polygon corner. The estimates of habitat lengths, widths, and areas did not differ when measured using two methods of data collection (GPS and a tape measure), nor did the differences among methods change at three stream sites with contrasting morphologies. Measuring features with a GPS receiver was up to 3.3 times faster on average than using a tape measure, although signal interference from high streambanks or overhanging vegetation occasionally limited satellite signal availability and prolonged measurements with a GPS receiver. There were also no differences in precision of habitat dimensions when mapped using a continuous versus a position fix average GPS data collection method. Despite there being some disadvantages to using the GPS in stream habitat studies, measuring stream habitats with a GPS resulted in spatially referenced data that allowed the assessment of relative habitat position and changes in habitats over time, and was often faster than using a tape measure. For most spatial scales of interest, the precision and accuracy of DGPS data are adequate and have logistical advantages when compared to traditional methods of measurement. ?? 2006 Springer Science+Business Media, Inc.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <div class="footer-extlink text-muted" style="margin-bottom:1rem; text-align:center;">Some links on this page may take you to non-federal websites. 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