Translocation of 14-C in ponderosa pine seedlings

Treesearch

Robert R. Ziemer

1971-01-01

The movement of 14-C from the old needles to the roots, and later to the new needles, was measured in 2-year-old ponderosa pine seedlings. The seedlings were in one of three growth stages at the time of the feeding of 14-CO-2: 9 days before spring bud break with no root activity; 7 days before spring bud break with high root activity; and 7 days after spring bud break...

Learning from Disaster: The Learning Environment of the 2006 Rutgers University Hurricane Katrina Relief Project and How Service Learning Generates Transformative Learning: A Case Study

ERIC Educational Resources Information Center

Heilman, Donald C.

2012-01-01

Problem: The study primarily focused on how a Service Learning project resulted in a Transformative Learning experience. The sample was drawn from 82 participants from Rutgers University who took part in a week-long alternative Spring Break community service project in New Orleans following Hurricane Katrina in 2006. Interviews were conducted…

Condom use less likely, high risk behavior more common at Spring break. Safe sex.

PubMed

1997-04-21

According to a Durex Sheik online survey of Panama City Beach, Florida, spring breakers, college students are actually less sexually active during spring break than they are back on campus, despite long-standing perceptions to the contrary. That's the good news. The bad news is that those having sex at spring break are more likely to be doing so with several different partners and less likely to be using condoms than they are back at school. The survey of 664 college students, who responded via beach side computers hooked up to the Internet, showed that 36% of spring breakers hadn't had any sexual encounters during their week at the beach vs. 23% who said they had no such encounters during a typical week at school. 23% said they had one encounter per week during spring break, while 18% had two or three liaisons, 9% had four or five, and 13% had more than five. A closer look at those who had more than five partners per week reveals even more startling figures: 47% said they did not use a condom during any of their encounters during spring break vs. 23% for all spring breakers and 15% for those who were with only one partner. And among those who had more than five partners and for whom alcohol was involved in all of their encounters, a shocking 74% didn't use condoms. "We conducted this survey to better understand sexual attitudes and behavior at spring break," said Catherine Taylor, Durex. "What we found is a small but dangerous group of individuals who are engaging in very risky behavior, supporting the belief that we need to talk to young adults in their own language to teach them how condoms can be a normal part of a healthy intimate relationship." To normalize the acceptance of condoms, two 7-foot-tall Durex condom characters handed out 70,000 free Durex Sheik condom samples in Panama City Beach. Durex Sheik also hosted an event with MTV "Singled Out" star Carmen Electra and conducted a hands-on game in which contestants, racing against the clock, slipped condoms on a demonstrator--blindfolded. full text

A spatial analysis of the spread of mumps: the importance of college students and their spring-break-associated travel.

PubMed

Polgreen, P M; Bohnett, L C; Yang, M; Pentella, M A; Cavanaugh, J E

2010-03-01

To characterize the association between county-level risk factors and the incidence of mumps in the 2006 Iowa outbreak, we used generalized linear mixed models with the number of mumps cases per county as the dependent variable. To assess the impact of spring-break travel, we tested for differences in the proportions of mumps cases in three different age groups. In the final multivariable model, the proportion of Iowa's college students per county was positively associated (P<0.0001) with mumps cases, but the number of colleges was negatively associated with cases (P=0.0002). Thus, if the college students in a county were spread among more campuses, this was associated with fewer mumps cases. Finally, we found the proportion of mumps cases in both older and younger persons increased after 1 April (P=0.0029), suggesting that spring-break college travel was associated with the spread of mumps to other age groups.

Alternative Fuels Data Center: Silicon Valley-based Electric Vehicle Parade

Science.gov Websites

Breaks Guinness World Record Silicon Valley-based Electric Vehicle Parade Breaks Guinness World Parade Breaks Guinness World Record on Facebook Tweet about Alternative Fuels Data Center: Silicon Valley -based Electric Vehicle Parade Breaks Guinness World Record on Twitter Bookmark Alternative Fuels Data

Record-Breaking Early Flowering in the Eastern United States

PubMed Central

Ellwood, Elizabeth R.; Temple, Stanley A.; Primack, Richard B.; Davis, Charles C.

2013-01-01

Flowering times are well-documented indicators of the ecological effects of climate change and are linked to numerous ecosystem processes and trophic interactions. Dozens of studies have shown that flowering times for many spring-flowering plants have become earlier as a result of recent climate change, but it is uncertain if flowering times will continue to advance as temperatures rise. Here, we used long-term flowering records initiated by Henry David Thoreau in 1852 and Aldo Leopold in 1935 to investigate this question. Our analyses demonstrate that record-breaking spring temperatures in 2010 and 2012 in Massachusetts, USA, and 2012 in Wisconsin, USA, resulted in the earliest flowering times in recorded history for dozens of spring-flowering plants of the eastern United States. These dramatic advances in spring flowering were successfully predicted by historical relationships between flowering and spring temperature spanning up to 161 years of ecological change. These results demonstrate that numerous temperate plant species have yet to show obvious signs of physiological constraints on phenological advancement in the face of climate change. PMID:23342001

INTERACTIONS BETWEEN SOIL TEMPERATURE AND PLANT GROWTH STAGE ON NITROGEN UPTAKE AND AMINO ACID CONTENT OF APPLE NURSERY STOCK DURING EARLY SPRING GROWTH

EPA Science Inventory

In the spring, nitrogen (N) uptake by apple roots is known to be delayed about three weeks after bud break. We used one-year-old 'Fuji' (Malus domestica Borkh) on M26 bare-root apple trees to determine whether timing of N uptake in the spring is dependant solely on the growth st...

Alternative Break Programs: From Isolated Enthusiasm to Best Practices--The Haiti Compact

ERIC Educational Resources Information Center

Piacitelli, Jill; Barwick, Molly; Doerr, Elizabeth; Porter, Melody; Sumka, Shoshanna

2013-01-01

Alternative break programs, which are short-term service-learning trips, immerse students in direct service and education, resulting in the creation of active citizens who think and act critically around the root causes of social issues. Over the last 20 years, domestic alternative breaks have effectively created strong community partnerships and…

Serving a Higher Power: The Influence of Alternative Break Programs on Students' Religiousness

ERIC Educational Resources Information Center

Niehaus, Elizabeth; Rivera, Mark

2016-01-01

The purpose of this study was to explore the relationship between students' religiousness and participation in alternative breaks (ABs) using both survey and interview data from the National Survey of Alternative Breaks. Findings from this mixed methods study demonstrate the potential for ABs to facilitate religiousness and help students connect…

THERMAL RELAY DEVICE

DOEpatents

Murdoch, R.O.; Record, F.A.

1963-01-29

This invention relates to a fast-acting spring-loaded electrical switch which can break a 1500-volt circuit in one millisecond without arcing. In particular, a springloaded shorting bar is held in tension by a fusible wire. Passage of an electrical current pulse through the fusible wire breaks the fuse thereby releasing the shorting bar to open one and close another electrical circuit. (AEC)

The record-breaking 2012 spring: Why degree-days were critical in assessing insect and plant development

USDA-ARS?s Scientific Manuscript database

In the spring of 2012, extremely high temperatures were recorded in the upper Midwest during the month of March. This sustained heat wave not only made March the warmest on record, but also induced remarkably fast development of arthropods and plants. In terms of degree-days, however, the arthropod ...

What to do on spring break? The role of predicted, on-line, and remembered experience in future choice.

PubMed

Wirtz, Derrick; Kruger, Justin; Napa Scollon, Christie; Diener, Ed

2003-09-01

When individuals choose future activities on the basis of their past experiences, what guides those choices? The present study compared students' predicted, on-line, and remembered spring-break experiences, as well as the influence of these factors on students' desire to take a similar vacation in the future. Predicted and remembered experiences were both more positive-and, paradoxically, more negative-than on-line experiences. Of key importance, path analyses revealed that remembered experience, but neither on-line nor anticipated experience, directly predicted the desire to repeat the experience. These results suggest that although on-line measures may be superior to retrospective measures for approximating objective experience, retrospective measures may be superior for predicting choice.

Alternative Breaks: The Impact of Student-to-Student Connections in Non-Classroom Service-Learning Experiences

ERIC Educational Resources Information Center

Johnson, Zac D.

2013-01-01

Alternative breaks represent a new tradition in collegiate service learning (Campus Connect, 2011), wherein students forego traditional break activities (e.g., vacations) to participate in community service with their peers through university sponsored programs. Despite their growing popularity these programs are understudied. Research that has…

Response of jammed packings to thermal fluctuations

NASA Astrophysics Data System (ADS)

Wu, Qikai; Bertrand, Thibault; Shattuck, Mark D.; O'Hern, Corey S.

2017-12-01

We focus on the response of mechanically stable (MS) packings of frictionless, bidisperse disks to thermal fluctuations, with the aim of quantifying how nonlinearities affect system properties at finite temperature. In contrast, numerous prior studies characterized the structural and mechanical properties of MS packings of frictionless spherical particles at zero temperature. Packings of disks with purely repulsive contact interactions possess two main types of nonlinearities, one from the form of the interaction potential (e.g., either linear or Hertzian spring interactions) and one from the breaking (or forming) of interparticle contacts. To identify the temperature regime at which the contact-breaking nonlinearities begin to contribute, we first calculated the minimum temperatures Tc b required to break a single contact in the MS packing for both single- and multiple-eigenmode perturbations of the T =0 MS packing. We find that the temperature required to break a single contact for equal velocity-amplitude perturbations involving all eigenmodes approaches the minimum value obtained for a perturbation in the direction connecting disk pairs with the smallest overlap. We then studied deviations in the constant volume specific heat C¯V and deviations of the average disk positions Δ r from their T =0 values in the temperature regime TC ¯V100 for linear spring interactions is independent of system size. This result emphasizes that contact-breaking nonlinearities are dominant over form nonlinearities in the low-temperature range Tc b

For Some at U. of Florida, Spring and Summer Are the New Academic Year

ERIC Educational Resources Information Center

Hoover, Eric

2013-01-01

Some students at University of Florida can take classes only during the spring and summer semesters for as long as they are enrolled. Each year they will get a four-month break--the fall semester--when they can take online courses, study abroad, or do internships. Some may opt to work. Despite their schedules, the students are full-fledged…

Effect of a 12-Week Summer Break on School Day Physical Activity and Health-Related Fitness in Low-Income Children from CSPAP Schools

PubMed Central

2017-01-01

Background. The purpose of this study was to examine the effect of a 12-week summer break on school day physical activity and health-related fitness (HRF) in children from schools receiving a Comprehensive School Physical Activity Program (CSPAP). Methods. Participants were school-aged children (N = 1,232; 624 girls and 608 boys; mean age = 9.5 ± 1.8 years) recruited from three low-income schools receiving a CSPAP. Physical activity and HRF levels were collected during the end of spring semester 2015 and again during the beginning of fall semester 2015. Physical activity was assessed using the Yamax DigiWalker CW600 pedometer. HRF measures consisted of body mass index (BMI) and the Progressive Aerobic Cardiovascular Endurance Run (PACER). Results. Results from a doubly MANCOVA analysis indicated that pedometer step counts decreased from 4,929 steps in the spring to 4,445 steps in the fall (mean difference = 484 steps; P < 0.001; Cohen's d = 0.30) and PACER laps decreased from 31.2 laps in the spring to 25.8 laps in the fall (mean difference = 5.4 laps; P < 0.001; Cohen's d = 0.33). Conclusions. Children from schools receiving a CSPAP intervention had lower levels of school day physical activity and cardiorespiratory endurance following a 12-week summer break. PMID:28377791

Effect of a 12-Week Summer Break on School Day Physical Activity and Health-Related Fitness in Low-Income Children from CSPAP Schools.

PubMed

Fu, You; Brusseau, Timothy A; Hannon, James C; Burns, Ryan D

2017-01-01

Background . The purpose of this study was to examine the effect of a 12-week summer break on school day physical activity and health-related fitness (HRF) in children from schools receiving a Comprehensive School Physical Activity Program (CSPAP). Methods . Participants were school-aged children ( N = 1,232; 624 girls and 608 boys; mean age = 9.5 ± 1.8 years) recruited from three low-income schools receiving a CSPAP. Physical activity and HRF levels were collected during the end of spring semester 2015 and again during the beginning of fall semester 2015. Physical activity was assessed using the Yamax DigiWalker CW600 pedometer. HRF measures consisted of body mass index (BMI) and the Progressive Aerobic Cardiovascular Endurance Run (PACER). Results . Results from a doubly MANCOVA analysis indicated that pedometer step counts decreased from 4,929 steps in the spring to 4,445 steps in the fall (mean difference = 484 steps; P < 0.001; Cohen's d = 0.30) and PACER laps decreased from 31.2 laps in the spring to 25.8 laps in the fall (mean difference = 5.4 laps; P < 0.001; Cohen's d = 0.33). Conclusions . Children from schools receiving a CSPAP intervention had lower levels of school day physical activity and cardiorespiratory endurance following a 12-week summer break.

Satellite and hydrographic observations of the Bering Sea ‘Green Belt’

NASA Astrophysics Data System (ADS)

Okkonen, Stephen R.; Schmidt, G. M.; Cokelet, E. D.; Stabeno, P. J.

2004-05-01

Green Belt is the aptly named region of high productivity occurring principally along and above the shelf-slope boundary in the Bering Sea. TOPEX altimeter measurements of sea-surface topography, SeaWiFS imagery of chlorophyll a concentration, and shipboard measurements of salinity and fluorescence are used to describe the surface structure of the Green Belt and its relationship to the Bering Slope Current eddy field during the 2000, 2001, and 2002 spring blooms. During spring 2000, high surface chlorophyll a concentrations (>10 mg m -3) were observed within a ˜200-km wide band adjacent to and seaward of the shelf break in the northwest Bering Sea. This high concentration chlorophyll band was associated with an anticyclonic eddy group that propagated along isobaths above the continental slope and entrained chlorophyll from the shelf-slope front. During spring 2001, anticyclonic eddies in the northwest Bering Sea had propagated off-slope prior to the onset of the spring bloom and were too far from the shelf-slope front to entrain frontal chlorophyll during the bloom. A second chlorophyll front associated with the leading edge of the off-slope eddies was observed. Between these two fronts was a region of relatively low chlorophyll a concentration (˜1 mg m -3). The eddy field during the 2002 spring bloom was observed to propagate northwestward adjacent to the shelf-break and entrain chlorophyll from the shelf-slope region in a manner similar to what was observed during the 2000 spring bloom. These observations suggest that eddies are important, if not the principal, agents that cause variability in the distribution of chlorophyll during the spring bloom in the central Bering Sea.

Integrating urban recharge uncertainty into standard groundwater modeling practice: A case study on water main break predictions for the Barton Springs segment of the Edwards Aquifer, Austin, Texas

NASA Astrophysics Data System (ADS)

Sinner, K.; Teasley, R. L.

2016-12-01

Groundwater models serve as integral tools for understanding flow processes and informing stakeholders and policy makers in management decisions. Historically, these models tended towards a deterministic nature, relying on historical data to predict and inform future decisions based on model outputs. This research works towards developing a stochastic method of modeling recharge inputs from pipe main break predictions in an existing groundwater model, which subsequently generates desired outputs incorporating future uncertainty rather than deterministic data. The case study for this research is the Barton Springs segment of the Edwards Aquifer near Austin, Texas. Researchers and water resource professionals have modeled the Edwards Aquifer for decades due to its high water quality, fragile ecosystem, and stakeholder interest. The original case study and model that this research is built upon was developed as a co-design problem with regional stakeholders and the model outcomes are generated specifically for communication with policy makers and managers. Recently, research in the Barton Springs segment demonstrated a significant contribution of urban, or anthropogenic, recharge to the aquifer, particularly during dry period, using deterministic data sets. Due to social and ecological importance of urban water loss to recharge, this study develops an evaluation method to help predicted pipe breaks and their related recharge contribution within the Barton Springs segment of the Edwards Aquifer. To benefit groundwater management decision processes, the performance measures captured in the model results, such as springflow, head levels, storage, and others, were determined by previous work in elicitation of problem framing to determine stakeholder interests and concerns. The results of the previous deterministic model and the stochastic model are compared to determine gains to stakeholder knowledge through the additional modeling

Influence of pellet seating on the external ballistic parameters of spring-piston air guns.

PubMed

Werner, Ronald; Schultz, Benno; Frank, Matthias

2016-09-01

In firearm examiners' and forensic specialists' casework as well as in air gun proof testing, reliable measurement of the weapon's muzzle velocity is indispensable. While there are standardized and generally accepted procedures for testing the performance of air guns, the method of seating the diabolo pellets deeper into the breech of break barrel spring-piston air guns has not found its way into standardized test procedures. The influence of pellet seating on the external ballistic parameters was investigated using ten different break barrel spring-piston air guns. Test shots were performed with the diabolo pellets seated 2 mm deeper into the breech using a pellet seater. The results were then compared to reference shots with conventionally loaded diabolo pellets. Projectile velocity was measured with a high-precision redundant ballistic speed measurement system. In eight out of ten weapons, the muzzle energy increased significantly when the pellet seater was used. The average increase in kinetic energy was 31 % (range 9-96 %). To conclude, seating the pellet even slightly deeper into the breech of spring-piston air guns might significantly alter the muzzle energy. Therefore, it is strongly recommended that this effect is taken into account when accurate and reliable measurements of air gun muzzle velocity are necessary.

Development of the RANCOR Rotary-Percussive Coring System for Mars Sample Return

NASA Technical Reports Server (NTRS)

Paulsen, Gale; Indyk, Stephen; Zacny, Kris

2014-01-01

A RANCOR drill was designed to fit a Mars Exploration Rover (MER) class vehicle. The low mass of 3 kg was achieved by using the same actuator for three functions: rotation, percussions, and core break-off. Initial testing of the drill exposed an unexpected behavior of an off-the-shelf sprag clutch used to couple and decouple rotary-percussive function from the core break off function. Failure of the sprag was due to the vibration induced during percussive drilling. The sprag clutch would back drive in conditions where it was expected to hold position. Although this did not affect the performance of the drill, it nevertheless reduced the quality of the cores produced. Ultimately, the sprag clutch was replaced with a custom ratchet system that allowed for some angular displacement without advancing in either direction. Replacing the sprag with the ratchet improved the collected core quality. Also, premature failure of a 300-series stainless steel percussion spring was observed. The 300-series percussion spring was ultimately replaced with a music wire spring based on performances of previously designed rotary-percussive drill systems.

Proposed plan for final remedial action for the groundwater operable unit at the chemical plant area of the Weldon Spring Site, Weldon Spring, Missouri.

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

2003-08-06

This Proposed Plan (PP) presents the preferred alternative for addressing contaminated groundwater and springs at the Chemical Plant area of the Weldon Spring site, in Weldon Spring, Missouri. The site is located about 30 mi west of St. Louis, in St. Charles County (Figure 1). This proposed action constitutes the final remedial action for the Weldon Spring site. The residual contamination in groundwater and springs at the Chemical Plant area is the only remaining contamination that needs to be addressed for the site. All other contamination has been addressed by previous remedial actions. After this remedial action is implemented, long-termmore » surveillance and maintenance activities will maintain the effectiveness of all remedial actions conducted at the Weldon Spring site, including this final remedial action for groundwater and springs that is being proposed in this plan. DOE complies with the requirements of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) in conducting remedial activities at the site. National Environmental Policy Act (NEPA) values have been incorporated into the CERCLA process; that is, the analysis conducted and presented in the remedial investigation/feasibility study (RI/FS) reports included an evaluation of environmental impacts that is comparable to that performed under NEPA. This PP is required under CERCLA to (1) notify the public and present a brief analysis of the remedial action alternatives, (2) identify and present the rationale for the preferred remedial action alternative identified in the PP, (3) summarize key information from the RI/FS evaluations, including the Baseline Risk Assessment (BRA), and (4) inform the public of its role in the remedy selection process and give the public the opportunity to participate in the process. Remediation activities at the Weldon Spring site have been coordinated with the U.S. Environmental Protection Agency (EPA) and the Missouri Department of Natural Resources (MDNR). The EPA has overall oversight and approval authority, with consultation provided by the MDNR. A range of alternatives was considered in identifying the preferred alternative. The alternatives were developed after careful analysis of geological, environmental, and human health and ecological risk data and an evaluation of the effectiveness, implementability, and cost of the various technologies available for groundwater remediation at the Chemical Plant area. Monitored natural attenuation (MNA) coupled with institutional controls (ICs) and contingency activities has been selected as the preferred alternative.« less

Dual Roles for DNA Polymerase Theta in Alternative End-Joining Repair of Double-Strand Breaks in Drosophila

PubMed Central

McVey, Mitch

2010-01-01

DNA double-strand breaks are repaired by multiple mechanisms that are roughly grouped into the categories of homology-directed repair and non-homologous end joining. End-joining repair can be further classified as either classical non-homologous end joining, which requires DNA ligase 4, or “alternative” end joining, which does not. Alternative end joining has been associated with genomic deletions and translocations, but its molecular mechanism(s) are largely uncharacterized. Here, we report that Drosophila melanogaster DNA polymerase theta (pol theta), encoded by the mus308 gene and previously implicated in DNA interstrand crosslink repair, plays a crucial role in DNA ligase 4-independent alternative end joining. In the absence of pol theta, end joining is impaired and residual repair often creates large deletions flanking the break site. Analysis of break repair junctions from flies with mus308 separation-of-function alleles suggests that pol theta promotes the use of long microhomologies during alternative end joining and increases the likelihood of complex insertion events. Our results establish pol theta as a key protein in alternative end joining in Drosophila and suggest a potential mechanistic link between alternative end joining and interstrand crosslink repair. PMID:20617203

Fatigue Life Assessment of 65Si7 Leaf Springs: A Comparative Study

PubMed Central

Arora, Vinkel Kumar; Bhushan, Gian; Aggarwal, M. L.

2014-01-01

The experimental fatigue life prediction of leaf springs is a time consuming process. The engineers working in the field of leaf springs always face a challenge to formulate alternate methods of fatigue life assessment. The work presented in this paper provides alternate methods for fatigue life assessment of leaf springs. A 65Si7 light commercial vehicle leaf spring is chosen for this study. The experimental fatigue life and load rate are determined on a full scale leaf spring testing machine. Four alternate methods of fatigue life assessment have been depicted. Firstly by SAE spring design manual approach the fatigue test stroke is established and by the intersection of maximum and initial stress the fatigue life is predicted. The second method constitutes a graphical method based on modified Goodman's criteria. In the third method codes are written in FORTRAN for fatigue life assessment based on analytical technique. The fourth method consists of computer aided engineering tools. The CAD model of the leaf spring has been prepared in solid works and analyzed using ANSYS. Using CAE tools, ideal type of contact and meshing elements have been proposed. The method which provides fatigue life closer to experimental value and consumes less time is suggested. PMID:27379327

Prom Health and Safety Tips

MedlinePlus

... Halloween Prom Tips Spring Break Valentine Tips Winter Holiday Tips 12 Ways Holiday Song Healthy Living Check-Ups are Important Check- ... Test Wash Hands Stay Warm Have a Healthy Holiday Don’t Drink and Drive Widgets Healthy People ...

Regular Check-Ups Are Important

MedlinePlus

... Halloween Prom Tips Spring Break Valentine Tips Winter Holiday Tips 12 Ways Holiday Song Healthy Living Check-Ups are Important Check- ... Test Wash Hands Stay Warm Have a Healthy Holiday Don’t Drink and Drive Widgets Healthy People ...

Transformation of Waves Across the Surf Zone.

DTIC Science & Technology

1981-03-01

Kuo is more realis- tic but still results in a sharp cut-off of the distribution at the breaking heights. 5. Goda Distribution Goda (1975) derived a...J.I., "Probabilities of Breaking Wave Characteris- tics ," Proc. 12th Coastal Engineering Conf., pp. 399- 412, 1970. Chakrabarty, S.K. and R.P. Cooley...Spring, MD 20910 21. Director 2 Instituto Oceanografico de la Armada Guayaquil, Ecuador 22. Director de Educacion de la Armada Comandancia General de

FDC Mentor-Mentee Mixer Breaks the Ice Between Investigators and Trainees | Poster

Cancer.gov

The Frederick Diversity Committee’s mentor-mentee mixer gave research trainees, senior investigators, scientists, and administrative staff a chance to meet and mingle over refreshments and games following the Spring Research Festival.

75 FR 68360 - Agency Forms Undergoing Paperwork Reduction Act Review

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-05

... greater proportions of the HIV epidemic. A convenience sample will be used to select attendees at (1) Gay Pride; (2) Minority Gay Pride; (3) black spring break; and (4) cultural and social events attracting...

Families with Special Needs: Caregiving Tips

MedlinePlus

... Halloween Prom Tips Spring Break Valentine Tips Winter Holiday Tips 12 Ways Holiday Song Healthy Living Check-Ups are Important Check- ... Test Wash Hands Stay Warm Have a Healthy Holiday Don’t Drink and Drive Widgets Healthy People ...

The impact of a shallow biobarrier on water recharge patterns in a semi-arid environment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laundre, J.W.

1997-12-31

This study attempted to measure the effect of a shallow biobarrier of gravel and cobble on water flow patterns during spring snow melt and recharge. The design consisted of 30 metal culverts 3 m in diameter and 1.6 m long, positioned on end. Test culverts contained 50-cm biobarrier of gravel or cobble and then an additional 50 cm of soil placed above the barrier layer. A neutron probe was used to measure soil moisture above and below the barrier. Measurements were made in the fall and again immediately after snow melt in the spring. During recharge, the biobarriers provided amore » capillary break which resulted in a pooling of water above the barrier layer. With sufficient snowmelt, the water can penetrate the break and possibly penetrate deeper than in the absence of the barrier layer.« less

Integrated hydraulic booster/tool string technology for unfreezing of stuck downhole strings in horizontal wells

NASA Astrophysics Data System (ADS)

Tian, Q. Z.

2017-12-01

It is common to use a jarring tool to unfreeze stuck downhole string. However, in a horizontal well, influenced by the friction caused by the deviated section, jarring effect is poor; on the other hand, the forcing point can be located in the horizontal section by a hydraulic booster and the friction can be reduced, but it is time-consuming and easy to break downhole string using a large-tonnage and constant pull force. A hydraulic booster - jar tool string has been developed for unfreezing operation in horizontal wells. The technical solution involves three elements: a two-stage parallel spring cylinder structure for increasing the energy storage capacity of spring accelerators; multiple groups of spring accelerators connected in series to increase the working stroke; a hydraulic booster intensifying jarring force. The integrated unfreezing tool string based on these three elements can effectively overcome the friction caused by a deviated borehole, and thus unfreeze a stuck string with the interaction of the hydraulic booster and the mechanical jar which form an alternatively dynamic load. Experimental results show that the jarring performance parameters of the hydraulic booster-jar unfreezing tool string for the horizontal wells are in accordance with original design requirements. Then field technical parameters were developed based on numerical simulation and experimental data. Field application shows that the hydraulic booster-jar unfreezing tool string is effective to free stuck downhole tools in a horizontal well, and it reduces hook load by 80% and lessens the requirement of workover equipment. This provides a new technology to unfreeze stuck downhole string in a horizontal well.

Seasonal variability of living benthic foraminifera from the outer continental shelf of the Bay of Biscay

NASA Astrophysics Data System (ADS)

Duchemin, Gérald; Jorissen, Frans J.; Le Loc'h, François; Andrieux-Loyer, Françoise; Hily, Christian; Thouzeau, Gérard

2008-08-01

Living benthic foraminiferal faunas of six stations from the continental shelf of the Bay of Biscay have been investigated during three successive seasons (spring, summer and autumn 2002). For the three investigated stations, bottom water oxygen concentration, oxygen penetration into the sediment and sediment organic carbon contents are all relatively similar. Therefore, we think that the density and the composition of the foraminiferal faunas is mainly controlled by the quantity and quality of organic input resulting from a succession of phytoplankton bloom events, occurring from late February to early September. The earliest blooms are positioned at the shelf break, late spring and early summer blooms occur off Brittany, whereas in late summer and early autumn, only coastal blooms appear, often in the vicinity of river outlets. In spring, the benthic foraminiferal faunas of central (B, C and D) and outer (E) continental shelf stations are characterised by strong dominance in the first area and strong presence in the second area of Nonionella iridea. In fact, station E does not serve as a major depocenter for the remains of phytoplankton blooms. If station E is not considered, the densities of this taxon show a clear gradient from the shelf-break, where the species dominates the assemblages, to the coast, where it attains very low densities. We explain this gradient as a response to the presence, in early spring, of an important phytoplankton bloom, mainly composed of coccolithophorids, over the shelf break. This observation is supported by the maximum particles flux values at stations close to the shelf break (18.5 g m - 2 h - 1 ) and lower values in a station closer to the coast (6.8 g m - 2 h - 1 ). In summer, the faunal density is maximum at station A, relatively close to more varied phytoplancton blooms that occur off Brittany until early June. We suggest that the dominant species, Nonion fabum, Cassidulina carinata and Bolivina ex. gr. dilatata respond to phytodetritus input from these blooms. In autumn, the rich faunas of inner shelf station G are dominated by N. fabum, B. ex. gr. dilatata, Hyalinea balthica and Nonionella turgida. These taxa seem to be correlated with the presence of coastal blooms phenomena, in front of river outlets. They may be favoured by an organic input with a significant contribution of terrestrial, rather low quality organic matter.

Alternative Breaks as a Context for Informal Interactions with Diversity

ERIC Educational Resources Information Center

Niehaus, Elizabeth

2016-01-01

One of the most frequently touted benefits of higher education is the opportunity to interact with people different from oneself, yet these interactions do not automatically lead to positive outcomes. The purpose of this study is to explore how one particular context for diversity interactions, service-based alternative break programs, may provide…

Supporting evaluation for the proposed plan for final remedial action for the groundwater operable unit at the chemical plant area of the Weldon Spring Site, Weldon Spring, Missouri.

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

2003-08-06

This report presents the technical information developed since the interim record of decision (IROD) was issued in September 2000 (U.S. Department of Energy [DOE] 2000). The information was incorporated into the evaluation that was performed in selecting the preferred alternative for the Chemical Plant groundwater operable unit (GWOU) of the Weldon Spring site. The contaminants of concern (COCs) in groundwater and springs are trichloroethylene (TCE), nitrate, uranium, and nitroaromatic compounds. The preferred alternative of monitored natural attenuation (MNA) coupled with institutional controls (ICs) and contingency activities is described in the ''Proposed Plan (PP) for Final Remedial Action for the Groundwatermore » Operable Unit at the Chemical Plant Area of the Weldon Spring Site, Weldon Spring, Missouri'' (DOE 2003b).« less

Check-Up Checklist: Things to Do Before Your Next Check-Up

MedlinePlus

... Halloween Prom Tips Spring Break Valentine Tips Winter Holiday Tips 12 Ways Holiday Song Healthy Living Check-Ups are Important Check- ... Test Wash Hands Stay Warm Have a Healthy Holiday Don’t Drink and Drive Widgets Healthy People ...

Evaluation of the break-out square post breakaway system.

DOT National Transportation Integrated Search

2015-02-01

Determine the effectiveness of the Break-Out Square (BOS) Post coupler as a : possible alternative to other breakaway devices. This product is designed to (upon : impact) break flush with grade with no damage apparent to base or anchor and offer a : ...

Analysis of Rail Vehicle Suspension Spring with Special Emphasis on Curving, Tracking and Tractive Efforts

NASA Astrophysics Data System (ADS)

Kumbhalkar, M. A.; Bhope, D. V.; Vanalkar, A. V.

2016-09-01

The dynamics of the rail vehicle represents a balance between the forces acting between wheel and rail, the inertia forces and the forces exerted by suspension and articulation. Axial loading on helical spring causes vertical deflection at straight track but failures calls to investigate for lateral and longitudinal loading at horizontal and vertical curves respectively. Goods carrying vehicle has the frequent failures of middle axle inner suspension spring calls for investigation. The springs are analyzed for effect of stress concentration due to centripetal force and due to tractive and breaking effort. This paper also discusses shear failure analysis of spring at curvature and at uphill at various speeds for different loading condition analytically and by finite element analysis. Two mass rail vehicle suspension systems have been analyzed for vibration responses analytically using mathematical tool Matlab Simulink and the same will be evaluated using FFT vibration analyzer to find peak resonance in vertical, lateral and longitudinal direction. The results prove that the suspension acquires high repeated load in vertical and lateral direction due to tracking and curving causes maximum stress concentration on middle axle suspension spring as height of this spring is larger than end axle spring in primary suspension system and responsible for failure of middle axle suspension spring due to high stress acquisition.

Extended Planting Seasons for Sycamore and Cottonwood

Treesearch

C. B. Briscoe

1973-01-01

Cuttings of sycamore and cottonwood can be planted successfully in wet soil from October until bud break in the spring. Sycamore seedlings can be planted all year if available soil moisture exceeds evapotranspiration. Dormant seedlings survived summer planting better than did freshly lifted seedlings.

Break-induced telomere synthesis underlies alternative telomere maintenance

PubMed Central

Dilley, Robert L.; Verma, Priyanka; Cho, Nam Woo; Winters, Harrison D.; Wondisford, Anne R.; Greenberg, Roger A.

2017-01-01

Homology-directed DNA repair is essential for genome maintenance through templated DNA synthesis. Alternative lengthening of telomeres (ALT) necessitates homology-directed DNA repair to maintain telomeres in about 10–15% of human cancers. How DNA damage induces assembly and execution of a DNA replication complex (break-induced replisome) at telomeres or elsewhere in the mammalian genome is poorly understood. Here we define break-induced telomere synthesis and demonstrate that it utilizes a specialized replisome, which underlies ALT telomere maintenance. DNA double-strand breaks enact nascent telomere synthesis by long-tract unidirectional replication. Proliferating cell nuclear antigen (PCNA) loading by replication factor C (RFC) acts as the initial sensor of telomere damage to establish predominance of DNA polymerase δ (Pol δ) through its POLD3 subunit. Break-induced telomere synthesis requires the RFC–PCNA–Pol δ axis, but is independent of other canonical replisome components, ATM and ATR, or the homologous recombination protein Rad51. Thus, the inception of telomere damage recognition by the break-induced replisome orchestrates homology-directed telomere maintenance. PMID:27760120

Effects of phyllotaxy on biomechanical properties of stems of Cercis occidentalis (Fabaceae).

PubMed

Caringella, Marissa A; Bergman, Brett A; Stanfield, Ryan C; Ewers, Madeleine M; Bobich, Edward G; Ewers, Frank W

2014-01-01

Phyllotaxy, the arrangement of leaves on a stem, may impact the mechanical properties of woody stems several years after the leaves have been shed. We explored mechanical properties of a plant with alternate distichous phyllotaxy, with a row of leaves produced on each side of the stem, to determine whether the nodes behave as spring-like joints. Flexural stiffness of 1 cm diameter woody stems was measured in four directions with an Instron mechanical testing system; the xylem of the stems was then cut into node (former leaf junction) and nonnode segments for measurement of xylem density. Stems had 20% greater flexural stiffness in the plane perpendicular to the original leaf placement than in the parallel plane. The xylem in the node region was more flexible, but it had significantly greater tissue density than adjacent regions, contradicting the usual correlation between wood density and stiffness. Nodes can behave as spring-like joints in woody plants. For plagiotropic shoots, distichous phyllotaxy results in stems that resist up-and-down bending more than lateral back-and-forth movement. Thus, they may more effectively absorb applied loads from fruits, animals, wind, rain, and snow and resist stresses due to gravity without cracking and breaking. Under windy conditions, nodes may improve damping by absorbing vibrational energy and thus reducing oscillation damage. The effect of plant nodes also has biomimetic design implications for architects and material engineers.

Better to Be Active (Rather Than Passive) When Considering How Soil Moisture Can Help Decision Makers

NASA Astrophysics Data System (ADS)

Mace, R.

2016-12-01

As recent events have shown, Texas is a land of drought and flood. Texas experienced the worst one-year drought of record in 2011; the second worst statewide drought of record between 2010 and 2015; and record-breaking floods in the spring of 2015, fall of 2015, and spring of 2016 (with flash droughts occurring during the summers of 2015 and 2016). Soil moisture is one factor that links drought and flood in addressing key policy and management questions: When will soil moisture be high enough to allow groundwater recharge and runoff into reservoirs? When will soil moisture be high enough to cause flash floods with excessive rainfall? After tragic floods in Wimberley in the spring of 2015, Texas is expanding its stream-flow monitoring capabilities and is starting a statewide mesonet called TexMesonet to provide more detailed weather information to flood forecasters but also to provide baseline information on soil moisture for flood, drought, and water conservation purposes. Our hope is that the TexMesonet will help ground-truth SMAP and other remote sensing systems, help improve the National Water Model (a next generation tool for flood forecasting), and spark research into sub-basin soil moisture predictors of runoff which break water-supply droughts or lead to major floods.

Alternative Break Programs and the Factors that Contribute to Changes in Students' Lives

ERIC Educational Resources Information Center

Niehaus, Elizabeth Kathleen

2012-01-01

The purpose of this study was to explore the extent to and ways in which student participants in Alternative Break (AB) programs report that their AB experience influenced their intentions or plans to volunteer, engage in advocacy, or study or travel abroad, or their major or career plans. Additional analysis explored the specific program…

Transcription and recombination: when RNA meets DNA.

PubMed

Aguilera, Andrés; Gaillard, Hélène

2014-08-01

A particularly relevant phenomenon in cell physiology and proliferation is the fact that spontaneous mitotic recombination is strongly enhanced by transcription. The most accepted view is that transcription increases the occurrence of double-strand breaks and/or single-stranded DNA gaps that are repaired by recombination. Most breaks would arise as a consequence of the impact that transcription has on replication fork progression, provoking its stalling and/or breakage. Here, we discuss the mechanisms responsible for the cross talk between transcription and recombination, with emphasis on (1) the transcription-replication conflicts as the main source of recombinogenic DNA breaks, and (2) the formation of cotranscriptional R-loops as a major cause of such breaks. The new emerging questions and perspectives are discussed on the basis of the interference between transcription and replication, as well as the way RNA influences genome dynamics. Copyright © 2014 Cold Spring Harbor Laboratory Press; all rights reserved.

Application of a planetary wave breaking parameterization to stratospheric circulation statistics

NASA Technical Reports Server (NTRS)

Randel, William J.; Garcia, Rolando R.

1994-01-01

The planetary wave parameterization scheme developed recently by Garcia is applied to statospheric circulation statistics derived from 12 years of National Meteorological Center operational stratospheric analyses. From the data a planetary wave breaking criterion (based on the ratio of the eddy to zonal mean meridional potential vorticity (PV) gradients), a wave damping rate, and a meridional diffusion coefficient are calculated. The equatorward flank of the polar night jet during winter is identified as a wave breaking region from the observed PV gradients; the region moves poleward with season, covering all high latitudes in spring. Derived damping rates maximize in the subtropical upper stratosphere (the 'surf zone'), with damping time scales of 3-4 days. Maximum diffusion coefficients follow the spatial patterns of the wave breaking criterion, with magnitudes comparable to prior published estimates. Overall, the observed results agree well with the parameterized calculations of Garcia.

Application of the Laplace-Borel transformation to the representation of analytical solutions of Duffing's equation

NASA Technical Reports Server (NTRS)

Truong, K. V.; Unal, Aynur; Tobak, M.

1989-01-01

Various features of the solutions of Duffing's equation are described using a representation of the solutions in the Laplace-Borel transform domain. An application of this technique is illustrated for the symmetry-breaking bifurcation of a hard spring.

College students' binge drinking at a beach-front destination during spring break.

PubMed

Smeaton, G L; Josiam, B M; Dietrich, U C

1998-05-01

Four hundred forty-two women and 341 men were surveyed at Panama City Beach, Florida, to assess the effects of gender, age, fraternity or sorority membership, and travel motivation on alcohol consumption and binge drinking during spring break. The mean number of drinks consumed the previous day was 18 for men and 10 for women; 91.7% of the men and 78.1% of the women had participated in a binge-drinking episode during the previous day. Respondents less than 21 years old consumed less alcohol and reported significantly lower frequencies of intoxication than those over 21. The men's reported levels of alcohol consumption, binge drinking, and intoxication to the point of sickness were significantly higher than the women's, but fraternity or sorority membership was not associated with higher levels of consumption. Students motivated to visit the specific destination because of its "party" reputation consumed significantly more alcohol than students who cited other reasons for going there.

Molecular Simulations of The Formation of Gold-Molecule-Gold Junctions

NASA Astrophysics Data System (ADS)

Wang, Huachuan

2013-03-01

We perform classical molecular simulations by combining grand canonical Monte Carlo (GCMC) sampling with molecular dynamics (MD) simulation to explore the dynamic gold nanojunctions in a Alkenedithiol (ADT) solvent. With the aid of a simple driving-spring model, which can reasonably represent the long-range elasticity of the gold electrode, the spring forces are obtained during the dynamic stretching procedure. A specific multi-time-scale double reversible reference system propagator (double-RESPA) algorithm has been designed for the metal-organic complex in MD simulations to identify the detailed metal-molecule bonding geometry at metal-molecule-metal interface. We investigate the variations of bonding sites of ADT molecules on gold nanojunctions at Au (111) surface at a constant chemical potential. Simulation results show that an Au-ADT-Au interface is formed on Au nanojunctions, bond-breaking intersection is at 1-1 bond of the monatomic chain of the cross-section, instead of at the Au-S bond. Breaking force is around 1.5 nN. These are consistent with the experimental measurements.

Assessing Alternative Breaks: Moving beyond Sleeping on Floors and Pass-the-Candle Reflection

ERIC Educational Resources Information Center

Porter, Melody C.

2011-01-01

Alternative breaks (ABs) often bring a smattering of images to mind: college students in matching T-shirts, cramped vans, well-used work gloves, physical labor, and, perhaps, way too much peanut butter. All of these images are at least in part accurate for the AB program at the College of William and Mary. Add to them a strong sense that sending…

Experimenting with Inexpensive Plastic Springs

ERIC Educational Resources Information Center

Perez, Leander; Marques, Adriana; Sánchez, Iván

2014-01-01

Acommon undergraduate laboratory experience is the determination of the elastic constant of a spring, whether studying the elongation under a static load or studying the damped harmonic motion of the spring with a suspended mass. An alternative approach to this laboratory experience has been suggested by Menezes et al., aimed at studying the…

Spring Break: A Lesson in Circuits. "This Old House" College Style.

ERIC Educational Resources Information Center

Duch, Barbara

2001-01-01

Introduces students to the topics of electricity and circuits within the context of house wiring. Explores the properties of series and parallel circuits, researches local wiring codes, calculates the current used by appliances based on their power ratings, and designs circuits in a typical kitchen. (Author/ASK)

Breaking through to Reluctant Readers

ERIC Educational Resources Information Center

Clarke, Bill

2006-01-01

With 70 percent of its student body entering school reading below grade level, Blackstone Academy Charter School realized that teachers needed to make literacy a pillar of the school's culture. This 9-12 urban high school administers a reading evaluation developed by the Northwest Evaluation Association each fall and spring to all incoming…

Flange joint system for SRF cavities utilizing high force spring clamps for low particle generation

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

A flange joint system for SRF cavities. The flange joint system includes a set of high force spring clamps that produce high force on the simple flanges of Superconducting Radio Frequency (SRF) cavities to squeeze conventional metallic seals. The system establishes the required vacuum and RF-tight seal with minimum particle contamination to the inside of the cavity assembly. The spring clamps are designed to stay within their elastic range while being forced open enough to mount over the flange pair. Upon release, the clamps have enough force to plastically deform metallic seal surfaces and continue to a new equilibrium sprungmore » dimension where the flanges remain held against one another with enough preload such that normal handling will not break the seal.« less

Modeling the Flexural Rigidity of Rod Photoreceptors

PubMed Central

Haeri, Mohammad; Knox, Barry E.; Ahmadi, Aphrodite

2013-01-01

In vertebrate eyes, the rod photoreceptor has a modified cilium with an extended cylindrical structure specialized for phototransduction called the outer segment (OS). The OS has numerous stacked membrane disks and can bend or break when subjected to mechanical forces. The OS exhibits axial structural variation, with extended bands composed of a few hundred membrane disks whose thickness is diurnally modulated. Using high-resolution confocal microscopy, we have observed OS flexing and disruption in live transgenic Xenopus rods. Based on the experimental observations, we introduce a coarse-grained model of OS mechanical rigidity using elasticity theory, representing the axial OS banding explicitly via a spring-bead model. We calculate a bending stiffness of ∼105 nN⋅μm2, which is seven orders-of-magnitude larger than that of typical cilia and flagella. This bending stiffness has a quadratic relation to OS radius, so that thinner OS have lower fragility. Furthermore, we find that increasing the spatial frequency of axial OS banding decreases OS rigidity, reducing its fragility. Moreover, the model predicts a tendency for OS to break in bands with higher spring number density, analogous to the experimental observation that transgenic rods tended to break preferentially in bands of high fluorescence. We discuss how pathological alterations of disk membrane properties by mutant proteins may lead to increased OS rigidity and thus increased breakage, ultimately contributing to retinal degeneration. PMID:23442852

A synthesis of recent research regarding the spring flood in Wisconsin: Knowns and unknowns

USDA-ARS?s Scientific Manuscript database

Approximately half of Wisconsin’s cranberry growers replace a spring insecticide application with a 1- to 2-day spring flood. Despite the potential for this flood to be a highly cost-effective alternative to chemical insect controls, growers need to know whether the flood can reduce pest pressure wi...

The reproductive success of lake herring in habitats near shipping channels and ice-breaking operations in the St. Marys River, Michigan, USA

USGS Publications Warehouse

Blouin, Marc A.; Kostich, M.M.; Todd, T.N.; Savino, J.F.

1998-01-01

A study of the reproductive success of lake herring (Coregonus artedi) in the St. Marys River was conducted in the winters and springs of 1994, 1995, and 1996. The St. Marys River connects Lake Superior to the lower Great Lakes making it an important route for ship traffic. Recent pressure by commercial carriers to extend the shipping season by breaking ice earlier in spring, has raised concerns over the possible adverse effects on lake herring reproduction in the river caused by increased turbidity associated with vessel passage. Lake herring spawn in fall and their eggs overwinter under ice cover on the bottom of the St. Marys River. Hatching occurs in the spring after ice-out when water temperatures rise. Specialized incubators were used to hold fertilized lake herring eggs at four experimental sites, chosen to represent the range of various bottom substrate types of the St. Marys River from boulder rock reefs to soft sediments. In winter, incubators were placed under the ice on the bottom of the river at three sites each year. After ice-out, sites were relocated, and the incubators were retrieved and opened to determine the number of live and dead lake herring eggs and larvae. Survival was consistent from year to year at each site with the lowest survival percentage found at the site with the softest sediments, directly adjacent to the St. Marys River channel and downstream of the mouth of the Charlotte River. River bottom type and geographic location were the most important factors in determining egg survival. Sampling for indigenous larval lake herring was done throughout the spring hatching season in the areas adjacent to the incubator sites using nets and a diver-operated suction sampler. Result indicate that a small population (3) of larval lake herring was present throughout the sampling areas during the springs of 1994, 1995, and 1996 in the St. Marys River.

Localization, characterization and candidate gene discovery for genes controlling dormancy, chilling requirement, bloom time, and heat requirement in Prunus species.

USDA-ARS?s Scientific Manuscript database

Perennial fruiting trees require sustained exposure to low, near freezing, temperatures before vigorous floral and vegetative bud break is possible after the resumption of warm temperatures in the spring. The depth of dormancy, duration of chilling required (the chilling requirement, CR) blooming da...

Like a Rock: Far Rockaway High School

ERIC Educational Resources Information Center

Whelan, Debra Lau

2007-01-01

Students from Far Rockaway High School are just back from spring break, and media specialist Geri Ellner is busy getting ready for her first class. She's already pulled out a copy of Anthony Browne's award-winning picture book "The Shape Game" (Farrar, 2003), and now she's patiently cuing up a Disney video of "Pocahontas" on…

Springs of Great Britain

NASA Astrophysics Data System (ADS)

Day, J. B. W.

1996-03-01

Predictably, in a country such as Britain, with its preponderance of consolidated, sedimentary, mainly fissure-flow aquifers, there is a very large number of springs, many of which are, or have been, used for public supply. Migratory springs are a feature of the British (Ur. Cretaceous) Chalk, the most important British aquifer. The Chalk's low specific yield and high capillary moisture retention together give rise to very considerable fluctuations (more than 33 m in some areas) of the unconfined water table. Along the gentle dip slopes of the Chalk (North and South Downs of southern and southeastern England) springs may migrate laterally for several miles, giving rise to seasonal streams locally known as “bournes” or “lavants”. However, springs such as at Duncton, West Sussex, at the base of the much steeper scarp slopes of the Chalk, form point sources, the flows from which tend to be relatively steady; such springs commonly supply and are the original reason for the existence of many of the small towns and villages which nestle along the bases of the chalk scarps of Sussex and Kent. Where the Chalk forms coastal cliffs, a number of springs break out at the base of the cliff between high and low tide levels; there are major chalk coastal springs, for instance, at St. Margaret's Bay (Kent) and at Arish Mells, east of Lulworth Cove, Dorset. Such springs are not used for direct supply (their salinity is usually too high) but are indicators of the presence of local reserves of groundwater for possible future development.

Spring predictability explains different leaf-out strategies in the woody floras of North America, Europe and East Asia.

PubMed

Zohner, Constantin M; Benito, Blas M; Fridley, Jason D; Svenning, Jens-Christian; Renner, Susanne S

2017-04-01

Intuitively, interannual spring temperature variability (STV) should influence the leaf-out strategies of temperate zone woody species, with high winter chilling requirements in species from regions where spring warming varies greatly among years. We tested this hypothesis using experiments in 215 species and leaf-out monitoring in 1585 species from East Asia (EA), Europe (EU) and North America (NA). The results reveal that species from regions with high STV indeed have higher winter chilling requirements, and, when grown under the same conditions, leaf out later than related species from regions with lower STV. Since 1900, STV has been consistently higher in NA than in EU and EA, and under experimentally short winter conditions NA species required 84% more spring warming for bud break, EU ones 49% and EA ones only 1%. These previously unknown continental-scale differences in phenological strategies underscore the need for considering regional climate histories in global change models. © 2017 John Wiley & Sons Ltd/CNRS.

Betting Decision Under Break-Streak Pattern: Evidence from Casino Gaming.

PubMed

Fong, Lawrence Hoc Nang; So, Amy Siu Ian; Law, Rob

2016-03-01

Cognitive bias is prevalent among gamblers, especially those with gambling problems. Grounded in the heuristics theories, this study contributes to the literature by examining a cognitive bias triggered by the break streak pattern in the casino setting. We postulate that gamblers tend to bet on the latest outcome when there is a break-streak pattern. Moreover, three determinants of the betting decision under break-streak pattern, including the streak length of the alternative outcome, the frequency of the latest outcome, and gender, were identified and examined in this study. A non-participatory observational study was conducted among the Cussec gamblers in a casino in Macao. An analysis of 1229 bets confirms our postulation, particularly when the streak of the alternative outcome is long, the latest outcome is frequent, and the gamblers are females. The findings provide meaningful implications for casino management and public policymakers regarding the minimization of gambling harm.

Educators' emotion regulation strategies and their physiological indicators of chronic stress over 1 year.

PubMed

Katz, Deirdre A; Harris, Alexis; Abenavoli, Rachel; Greenberg, Mark T; Jennings, Patricia A

2018-04-01

Studies show teaching is a highly stressful profession and that chronic work stress is associated with adverse health outcomes. This study analysed physiological markers of stress and self-reported emotion regulation strategies in a group of middle school teachers over 1 year. Chronic physiological stress was assessed with diurnal cortisol measures at three time points over 1 year (fall, spring, fall). The aim of this longitudinal study was to investigate the changes in educators' physiological level of stress. Results indicate that compared to those in the fall, cortisol awakening responses were blunted in the spring. Further, this effect was ameliorated by the summer break. Additionally, self-reported use of the emotion regulation strategy reappraisal buffered the observed blunting that occurred in the spring. Copyright © 2017 John Wiley & Sons, Ltd.

49 CFR 236.2 - Grounds.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., single-break, signal control circuits using a grounded common, and alternating current power distribution...) Alternating current power distribution circuits that are grounded in the interest of safety. ...

Spring cleaning: rural water impacts, valuation, and property rights institutions.

PubMed

Kremer, Michael; Leino, Jessica; Miguel, Edward; Zwane, Alix Peterson

2011-01-01

Using a randomized evaluation in Kenya, we measure health impacts of spring protection, an investment that improves source water quality. We also estimate households' valuation of spring protection and simulate the welfare impacts of alternatives to the current system of common property rights in water, which limits incentives for private investment. Spring infrastructure investments reduce fecal contamination by 66%, but household water quality improves less, due to recontamination. Child diarrhea falls by one quarter. Travel-cost based revealed preference estimates of households' valuations are much smaller than both stated preference valuations and health planners' valuations, and are consistent with models in which the demand for health is highly income elastic. We estimate that private property norms would generate little additional investment while imposing large static costs due to above-marginal-cost pricing, private property would function better at higher income levels or under water scarcity, and alternative institutions could yield Pareto improvements.

Earth Observations taken by Expedition 34 crewmember

NASA Image and Video Library

2013-03-12

ISS034-E-067298 (12 March 2013) --- One of the Expedition 34 crew members aboard the International Space Station recorded this image of much of Galveston Island (right hand two-thirds of the photo), which is annually a popular "spring break" spot for students and vacationers from all over. The activities were just getting started when this photo was made -- about ten days before the "official" start of spring. The west end of Bolivar Peninsula is visible in the lower left quadrant of the image. The Bolivar area looks much different from the way it appeared prior to the devastating Hurricane Ike in September 2008.

Lattice input on the inclusive flavor-breaking τ Vus puzzle

NASA Astrophysics Data System (ADS)

Maltman, Kim; Hudspith, Renwick; Lewis, Randy; Wolfe, Carl; Zanotti, James

2015-10-01

Recent versions of the standard approach to implementing the flavor-breaking finite-energy sum rule determination of Vus using spectral data obtained from hadronic tau decays produce values of Vus more than 3 sigma low relative to the expectations of 3-family unitarity. We revisit this problem, focusing on systematic issues in the treatment of OPE contributions, employing lattice data for the relevant flavor-breaking correlator combinination to help in understanding how to treat the slowly converging D = 2 series and investigate potential D > 4 non-perturbative contributions. The results, in combination with observations from additional flavor-breaking continuum sum rules, are shown to suggest an alternate implementation of the flavor-breaking sum rule approach. This alternate analysis approach is shown to produce significantly higher Vus than obtained using the assumptions of the conventional implementation, for reasons that will be explained in detail. We also show that, when this approach is implemented using new preliminary results for the tau K pi branching fractions, the Vus obtained is in excellent agreement with that obtained from recent analyses of Kell3 using lattice input for f+(0).

2014 Madison County, Indiana, Heartland in Motion Transportation Study |

Science.gov Websites

travel survey and a set of stated preference experiments. Households were asked to provide details of regional public schools were in session, prior to spring break. Survey Records Survey records include a households that participated in the main study and answered every survey question. Because the primary

"Ayni" in the Global Village: Building Relationships of Reciprocity through International Service-Learning.

ERIC Educational Resources Information Center

Porter, Maureen; Monard, Kathia

2001-01-01

Uses the indigenous Andean concept of "ayni" to extend the idea of reciprocity as an aim of service learning. Draws on student reflections from a semester-long seminar with spring break building project in Bolivia to offer eight applications of the concept. These applications offer doorways to discuss the challenges of fostering mutual,…

Break the "wall" and become creative: Enacting embodied metaphors in virtual reality.

PubMed

Wang, Xinyue; Lu, Kelong; Runco, Mark A; Hao, Ning

2018-07-01

This study investigated whether the experience of "breaking the walls", the embodiment of the metaphor "breaking the rules", could enhance creative performance. The virtual reality technology was used to simulate the scenario where participants could "break the walls" while walking in a corridor. Participants were asked to solve the creativity-demanding problems (ie., alternative uses tasks, AUT) in either the "break" condition in which they had to break the walls to move forward in VR, or the "no-break" condition where no barrier walls would appear. Results showed higher AUT originality and AUT fluency in the "break" condition than in the "no-break" condition. Moreover, the effects of "breaking the walls" on AUT originality were fully mediated by cognitive flexibility and persistence. These findings may indicate that enacting metaphors such as "breaking the rules" contribute to creative performance. The enhanced cognitive flexibility and persistence may account for the benefits. Copyright © 2018 Elsevier Inc. All rights reserved.

Secure RFID tag or sensor with self-destruction mechanism upon tampering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nekoogar, Faranak; Dowla, Farid; Twogood, Richard

A circuit board anti-tamper mechanism comprises a circuit board having a frangible portion, a trigger having a trigger spring, a trigger arming mechanism actuated by the trigger wherein the trigger arming mechanism is initially non-actuated, a force producing mechanism, a latch providing mechanical communication between the trigger arming mechanism and the force producing mechanism, wherein the latch initially retains the force producing mechanism in a refracted position. Arming pressure applied to the trigger sufficient to overcome the trigger spring force will actuate the trigger arming mechanism, causing the anti-tamper mechanism to be armed. Subsequent tampering with the anti-tamper mechanism resultsmore » in a decrease of pressure on the trigger below the trigger spring force, thereby causing the trigger arming mechanism to actuate the latch, thereby releasing the force producing mechanism to apply force to the frangible portion of the circuit board, thereby breaking the circuit board.« less

Analysis of Pulsed Flow Modification Alternatives, Lower Missouri River, 2005

USGS Publications Warehouse

Jacobson, Robert B.

2008-01-01

The graphical, tabular, and statistical data presented in this report resulted from analysis of alternative flow regime designs considered by a group of Missouri River managers, stakeholders, and scientists during the summer of 2005. This plenary group was charged with designing a flow regime with increased spring flow pulses to support reproduction and survival of the endangered pallid sturgeon. Environmental flow components extracted from the reference natural flow regime were used to design and assess performance of alternative flow regimes. The analysis is based on modeled flow releases from Gavins Point Dam (near Yankton, South Dakota) for nine design alternatives and two reference scenarios; the reference scenarios are the run-of-the-river and the water-control plan implemented in 2004. The alternative designs were developed by the plenary group with the goal of providing pulsed spring flows, while retaining traditional social and economic uses of the river.

Assessing Global Learning in Short-Term Study Abroad: Population, Environment, and Society in Shanghai

ERIC Educational Resources Information Center

Core, Rachel S.

2017-01-01

This teaching note suggests that a short-term study abroad program embedded within a longer course can be a tool for enhancing global learning. The work uses the Association of American Colleges and Universities (AAC&U) Global Learning VALUE rubric to evaluate student work from a spring break seminar to Shanghai, China. The seminar was…

Engaging in Meaningful Conversation about Socioeconomic Status and Class Identity

ERIC Educational Resources Information Center

Carroll, Rasheda; David, Jason

2016-01-01

Where are you going for spring break? How many colleges did you apply to? Why are you not going on the international service-learning trip? These are the sort of questions students and colleagues ask each other in advisories, classrooms, and hallways. No doubt they are born out of intentions to connect. They are not meant to embarrass or be…

Aggression, academic behaviors, and popularity perceptions among boys of color during the transition to middle school.

PubMed

Xie, Hongling; Dawes, Molly; Wurster, Tabitha J; Shi, Bing

2013-01-01

The transition to middle school often presents behavioral and academic challenges to youths. Boys of color (i.e., African American and Hispanic in this study) may be especially vulnerable. In this study, peer nominations of aggressive and academic behaviors as well as youths' perceptions of how these behaviors were related to popularity in peer networks were obtained from the spring semester of fifth grade through the spring semester of seventh grade, with the transition occurring as the students entered the sixth grade. The sample included 188 boys (71 Caucasian, 90 African American, and 27 Hispanic) from an urban school district in the northeastern United States. Trajectory analyses showed that African American boys scored lower in studentship and higher in rule-breaking and aggressive (both physical and social) behaviors prior to the transition, and such differences among ethnic groups were largely maintained during the transition. Hispanic boys displayed decreases in their studentship during the transition. African American boys' perception of how studentship affects popularity was more positive than other boys prior to the transition, but it decreased during the transition. African American boys also endorsed rule breaking and physical and social aggression more positively for popularity prior to the transition, whereas Caucasian and Hispanic boys' endorsement increased during the transition and eventually caught up with those of African American boys in seventh grade. A positive within-individual association was found between youths' popularity perception and their behavior for studentship, rule breaking, and physical aggression, which did not differ by ethnicity. © 2013 American Orthopsychiatric Association.

Seasonal cross-shelf distribution of major zooplankton taxa on the northern Gulf of Alaska shelf relative to water mass properties, species depth preferences and vertical migration behavior

NASA Astrophysics Data System (ADS)

Coyle, Kenneth O.; Pinchuk, Alexei I.

2005-01-01

The cross-shelf distribution of major zooplankton species was examined on the northern Gulf of Alaska (GOA) shelf during the production season for four years, between October 1997 and October 2001. The zooplankton community on the northern GOA shelf consisted of oceanic and neritic species of the North Pacific subarctic species complex. Cross-shelf distribution of the major zooplankton species was influenced by their depth preferences, vertical migration behavior, salinity-temperature preferences, and by cross-shelf water-mass distribution and movement. The neritic community, dominated by Pseudocalanus spp., Metridia pacifica and Calanus marshallae, had highest abundances on the inner shelf, in the Alaska Coastal Current, and in the adjacent fjords in late spring and early summer. The oceanic community, which contained primarily Neocalanus cristatus and Eucalanus bungii, was observed in the Alaskan Stream and adjacent waters near the shelf break. A mid-shelf transition zone contained a mixture of oceanic and neritic species. Prince William Sound (PWS) contained a unique species complex of large mesopelagic copepods, amphipods and shrimp. Neocalanus flemingeri and Oithona similis were abundant in all four regions during spring and early summer. The transition zone commonly crossed much of the shelf between the shelf break and the ACC, but satellite images and CTD data indicate that occasionally a narrow shelf-break front can form, in which case distinct zooplankton species groups are observed on either side of the front. Satellite data also revealed numerous large and small eddies, which probably contribute to cross-shelf mixing in the transition zone.

Ethics skills laboratory experience for surgery interns.

PubMed

Moon, Margaret R; Hughes, Mark T; Chen, Jiin-Yu; Khaira, Kiran; Lipsett, Pamela; Carrese, Joseph A

2014-01-01

Ethics curricula are nearly universal in residency training programs, but the content and delivery methods are not well described, and there is still a relative paucity of literature evaluating the effect of ethics curricula. Several commentators have called for more ethics curriculum development at the postgraduate level, and specifically in surgery training. We detail our development and implementation of a clinical ethics curriculum for surgery interns. We developed curricula and simulated patient cases for 2 core clinical ethics skills--breaking bad news and obtaining informed consent. Educational sessions for each topic included (1) framework development (discussion of interns' current experience, development of a consensus framework for ethical practice, and comparison with established frameworks) and (2) practice with simulated patient followed by peer and faculty feedback. At the beginning and end of each session, we administered a test of confidence and knowledge about the topics to assess the effect of the sessions. A total of 98 surgical interns participated in the ethics skills laboratory from Spring 2008 to Spring 2011. We identified significant improvement in confidence regarding the appropriate content of informed consent (<0.001) and capacity to break bad news (<0.001). We also identified significant improvement in overall knowledge regarding informed consent (<0.01), capacity assessment (<0.05), and breaking bad news (0.001). Regarding specific components of informed consent, capacity assessment, and breaking bad news, significant improvement was shown in some areas, while we failed to improve knowledge in others. Through faculty-facilitated small group discussion, surgery interns were able to develop frameworks for ethical practice that paralleled established frameworks. Skills-based training in clinical ethics resulted in an increase in knowledge scores and self-reported confidence. Evaluation of 4 annual cohorts of surgery interns demonstrates significant successes and some areas for improvement in this educational intervention. Copyright © 2014 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Instant Recess®: a practical tool for increasing physical activity during the school day.

PubMed

Whitt-Glover, Melicia C; Ham, Sandra A; Yancey, Antronette K

2011-01-01

An increased prevalence of overweight/obesity among children has led to school district level policies to increase physical activity (PA) among elementary school students. Interventions are needed that increase activity levels without sacrificing time spent in academics. We evaluated a policy implementation intervention for to increase in-school PA in elementary schools in Forsyth County, North Carolina, in a randomized study with a delayed intervention control group. The study included third- through fifth-grade classrooms in eight elementary schools. Instant Recess® was used to introduce 10-minute PA breaks in classrooms on schedules determined by teachers. Direct observation was used to measure activity levels, other student behaviors, and teacher behaviors related to PA in the classrooms. Twenty-eight visits to schools were made during the spring and fall semesters of 2009. At baseline 11% to 44% of intervention and control schools were engaged in classroom-based PA. PA increased from baseline to spring follow-up in intervention schools and was maintained the following fall. Control schools decreased PA from baseline to spring and increased PA once they began the intervention. Students in classrooms engaged in Instant Recess exhibited statistically significant increases in light (51%) and moderate-intensity (16%) PA and increases in time spent in on-task behavior (11%). Control schools experienced similar benefits after they began implementing Instant Recess. Instant Recess is useful for increasing PA and improving behavior among elementary school children. Additional research may be needed to understand how to create policies supporting classroom activity breaks and how to assess policy adherence.

Permanent-Magnet Meissner Bearing

NASA Technical Reports Server (NTRS)

Robertson, Glen A.

1994-01-01

Permanent-magnet meissner bearing features inherently stable, self-centering conical configuration. Bearing made stiffer or less stiff by selection of magnets, springs, and spring adjustments. Cylindrical permanent magnets with axial magnetization stacked coaxially on rotor with alternating polarity. Typically, rare-earth magnets used. Magnets machined and fitted together to form conical outer surface.

Sticks and Stones May Break My Bones, but Names will Make Me Feel Sick: The Psychosocial, Somatic, and Scholastic Consequences of Peer Harassment

ERIC Educational Resources Information Center

Nishina, Adrienne; Juvonen, Jaana; Witkow, Melissa R.

2005-01-01

This study examined associations among peer victimization, psychosocial problems, physical symptoms, and school functioning across the 1st year in middle school. An ethnically diverse sample of urban 6th graders (N = 1,526) reported on their perceptions of peer victimization, psychosocial adjustment, and physical symptoms during fall and spring.…

Biology, spread, and biological control of winter moth in the eastern United States

Treesearch

Joseph Elkinton; George Boettner; Andrew Liebhold; Rodger Gwiazdowski

2015-01-01

The winter moth (Operophtera brumata L.; Lepidoptera: Geometridae) is an inchworm caterpillar that hatches coincident with bud-break on its hosts and feeds on a wide range of deciduous trees. It is one of a group of geometrid species that feed in early spring and then pupate in the top layer of the soil or litter beginning in mid-May. As postulated...

Graduation: Navigating a Legal Minefield. A Legal Memorandum: Quarterly Law Topics for School Leaders. Vol. 7, No. 3, Spring 2007

ERIC Educational Resources Information Center

Kirby, Elizabeth; Swem, Lisa

2007-01-01

High school graduation is an important milestone for students and their families, and plans for family gatherings and celebrations are often made early in the senior year. Despite the anticipation, some seniors will not graduate because of insufficient credits, disciplinary action, or failure to pass a state exam. Breaking the news to students and…

Forest fire danger in western Oregon and Washington during 1953.

Treesearch

Owen P. Cramer

1953-01-01

Following two successive fire seasons of record breaking severity, the 1953 season set new records for low fire danger in western Oregon and Washington. The low danger is reflected in the fire record—the U. S. Forest Service and forestry offices of both States all report the lowest acreage burned since fire records have been kept. A cool, wet spring, above...

Leaf flush in black walnut at several midwest locations

Treesearch

Calvin F. Bey

1972-01-01

Late spring frosts damage the tender new growth of black walnut trees, and the earliest trees to break dormancy are vulnerable for the longest period. Walnut trees growing in coves and low spots (frost pockets) are most vulnerable. If the terminal shoot is killed, one or more lateral buds at the base of the newly killed shoot commonly develop; generally, the result is...

M-X Environmental Technical Report. Alternative Potential Operating Base Locations, Coyote Spring Valley.

DTIC Science & Technology

1980-12-22

necessary and identify by block number) MX Coyote Spring, Nevada Siting Analysis Nevada Environnental Report 20. ABSTRACT (Continue on reverse side If...necessary and Identify by block number) The area of analysis (AO) for the Coyote Spring Valley operating base option includes both Clark and Lincoln...counties, and is located in the southern portion of the designated region of influence. Las Vegas and the surrounding suburbs are the major settlements and

13 CFR 125.2 - What are SBA's and the procuring agency's responsibilities when providing contracting assistance...

Code of Federal Regulations, 2014 CFR

2014-01-01

... justified); is for construction and seeks to package or consolidate discrete construction projects; or if a... alternatives may include: (A) Breaking up the procurement into smaller discrete procurements, especially construction acquisitions that can be procured as separate projects; (B) Breaking out one or more discrete...

LEAD SEVERING CONTRIVANCE

DOEpatents

Widmaier, W.

1958-04-01

A means for breaking an electrical circuit within an electronic tube during the process of manufacture is described. Frequently such circuits must be employed for gettering or vapor coating purposes, however, since an external pair of corector pins having no use after manufacture, is undesirable, this invention permits the use of existing leads to form a temporary circuit during manufacture, and severing it thereafter. One portion of the temporary circuit, made from a springy material such as tungsten, is spot welded to a fusable member. To cut the circuit an external radiant heat source melts the fusable member, allowing the tensed tungsten spring to contract and break the circuit. This inexpensive arrangement is particularly useful when the tube has a great many external leads crowded into the tube base.

A new pneumatic suspension system with independent stiffness and ride height tuning capabilities

NASA Astrophysics Data System (ADS)

Yin, Zhihong; Khajepour, Amir; Cao, Dongpu; Ebrahimi, Babak; Guo, Konghui

2012-12-01

This paper introduces a new pneumatic spring for vehicle suspension systems, allowing independent tuning of stiffness and ride height according to different vehicle operating conditions and driver preferences. The proposed pneumatic spring comprises a double-acting pneumatic cylinder, two accumulators and a tuning subsystem. This paper presents a detailed description of the pneumatic spring and its working principle. The mathematical model is established based on principles of thermo and fluid dynamics. An experimental setup has been designed and fabricated for testing and evaluating the proposed pneumatic spring. The analytical and experimental results confirm the capability of the new pneumatic spring system for independent tuning of stiffness and ride height. The mathematical model is verified and the capabilities of the pneumatic spring are further proved. It is concluded that this new pneumatic spring provides a more flexible suspension design alternative for meeting various conflicting suspension requirements for ride comfort and performance.

Biogeochemical Carbon Cycling in Ultrabasic Reducing Springs in Sonoma County, CA

NASA Astrophysics Data System (ADS)

Cotton, J. M.; Morrill, P.; Johnson, O.; Nealson, K. H.; Sherwood Lollar, B.; Eigenbrode, J.; Fogel, M.

2006-12-01

Dissolved gases in the ultrabasic spring waters from The Cedars in Sonoma County, CA were analyzed for concentrations and carbon and hydrogen isotopic ratios in order to determine the geobiological processes occurring in this extreme environment of unknown biological activity. The ultrabasic, highly reducing conditions unique to these springs result from local serpentinization. Gases bubbling from the springs are mainly composed of methane, hydrogen, and nitrogen. Serpentinization is a process characteristic of early Earth, Mars and Titan that is thought to produce abiogenic hydrocarbons as well as provide geochemical energy for chemolithotrophic life. Methane, CO2, hydrogen and nitrogen were detected in the aqueous phases. Earlier work indicated that the primary source of the methane in the free gases bubbling from the springs was associated with microbial fermentation a suspected source of the dissolved methane. Here we report, a negative, linear correlation between concentrations of CO2 and methane that is an indicator of microbial anaerobic methane oxidation taking place in the ultrabasic waters. Furthermore, as the concentrations of methane decrease, the concentration of CO2 increases and both reactant and product become 13C-enriched. These observations are consistent with microbial oxidation of methane, suggesting a biogeochemical carbon cycle exists in these springs. We hypothesize that one group of microbes is breaking down organic matter by a process of fermentation to produce methane and CO2. The CO2 dissolves in the basic springs, while most of the methane escapes solution. The residual dissolved methane undergoes a conversion to CO2 by anaerobic methane oxidation.

Resonance Effects in Magnetically Driven Mass-Spring Oscillations

ERIC Educational Resources Information Center

Taylor, Ken

2011-01-01

Resonance effects are among the most intriguing phenomena in physics and engineering. The classical case of a mass-spring oscillator driven at its resonant frequency is one of the earliest examples that students encounter. Perhaps the most commonly depicted method of driving the vibrating system is mechanical. An alternative approach presented in…

Acute Effects of Classroom Exercise Breaks on Executive Function and Math Performance: A Dose-Response Study.

PubMed

Howie, Erin K; Schatz, Jeffrey; Pate, Russell R

2015-01-01

The purpose of this study was to determine the acute dose-response relationship of classroom exercise breaks with executive function and math performance in 9- to 12-year-old children by comparing 5-min, 10-min, or 20-min classroom exercise breaks to 10 min of sedentary classroom activity. This study used a within-subjects experimental design conducted in the spring of 2012. Ninety-six 4th- and 5th-grade students in 5 classrooms in South Carolina were randomized to receive each of 4 treatments: 5-min, 10-min, or 20-min exercise breaks or 10 min of a sedentary lesson led by research staff. Students completed the Trail-Making Test, an Operational Digit Recall test, and a math fluency test immediately before and after each condition. Planned linear contrasts were used to compare posttest scores between conditions using a repeated-measures mixed model, adjusted for gender, classroom, and the time-varying pretest scores. Potential effect modifiers were added as interaction terms. Math scores were higher after the 10-min and 20-min exercise breaks compared with the sedentary condition (d = 0.24, p = .04, and d = 0.27, p = .02, respectively), and an interaction was observed with gender, IQ, aerobic fitness, and lower engagement in some of the conditions. There were no improvements in executive function tasks. A 10-min and 20-min classroom exercise break moderately improved math performance in students compared with a seated classroom lesson.

Breaking Boundaries: Complementary and Alternative Medicine Provider Framing of Preventive Care.

PubMed

Agarwal, Vinita

2017-11-01

This textual examination extends understandings of how complementary and alternative medicine (CAM) providers constitute preventive care in their discourse by identifying the frame of breaking boundaries referencing relational, structural, and philosophical orientations in their practice with their clients. Analysis of semistructured, in-depth interviews with CAM providers ( n = 17) reveals that the frame of breaking boundaries was comprised of three themes: finding one's own strength; I don't prescribe, so I'm exploring; and ground yourself, and have an escape route. The themes describe preventive care by identifying how CAM providers negotiate their relational positionality in connecting with clients, structural positionality within the field of health care, and philosophical positionality within the ontological understandings that guide how health is defined and conceptualized. The study contributes toward enhancing diverse understandings of constituting preventive care in practice and suggests pragmatic implications for addressing biomedical provider communication with their patients seeking CAM care alongside conventional treatments.

Insights into the effects of patchy ice layers on water balance heterogeneity in peatlands

NASA Astrophysics Data System (ADS)

Dixon, Simon; Kettridge, Nicholas; Devito, Kevin; Petrone, Rich; Mendoza, Carl; Waddington, Mike

2017-04-01

Peatlands in boreal and sub-arctic settings are characterised by a high degree of seasonality. During winter soils are frozen and snow covers the surface preventing peat moss growth. Conversely, in summer, soils unfreeze and rain and evapotranspiration drive moss productivity. Although advances have been made in understanding growing season water balance and moss dynamics in northern peatlands, there remains a gap in knowledge of inter-seasonal water balance as layers of ice break up during the spring thaw. Understanding the effects of ice layers on spring water balance is important as this coincides with periods of high wildfire risk, such as the devastating Fort McMurrary wildfire of May, 2016. We hypothesise that shallow layers of ice disconnect the growing surface of moss from a falling water table, and prevent water from being supplied from depth. A disconnect between the evaporating surface and deeper water storage will lead to the drying out of the surface layer of moss and a greater risk of severe spring wildfires. We utilise the unsaturated flow model Hydrus 2D to explore water balance in peat layers with an impermeable layer representing ice. Additionally we create models to represent the heterogeneous break up of ice layers observed in Canadian boreal peatlands; these models explore the ability of breaks in an ice layer to connect the evaporating surface to a deeper water table. Results show that peatlands with slower rates of moss growth respond to dry periods by limiting evapotranspiration and thus maintain moist conditions in the sub-surface and a water table above the ice layer. Peatlands which are more productive continue to grow moss and evaporate during dry periods; this results in the near surface mosses drying out and the water table dropping below the level of the ice. Where there are breaks in the ice layer the evaporating surface is able to maintain contact with a falling water table, but connectivity is limited to above the breaks, with limited lateral transfer of water above the ice. Conceptually this means that peatlands which tend to have lower rates of growth are largely unaffected by the presence of a shallow ice layer in the early growing season, and are able to maintain moist sub-surface conditions in the absence of precipitation. They will thus be more resistant to severe wildfire. Conversely, peatlands which tend towards higher levels of moss productivity are able to maintain moss growth during dry periods. In the presence of an ice layer this greater productivity leads to a disconnection from deep water sources, extensive drying out of moss above the ice, and a greater susceptibility to severe wildfires. Our study gives important insights into the mechanisms behind heterogeneity in burning and depth of burn in northern peatland wildfires, as well as into burn heterogeneity within peatland microtopography.

Environmental and biological factors controlling the spring phytoplankton bloom at the Patagonian shelf-break front - Degraded fucoxanthin pigments and the importance of microzooplankton grazing

NASA Astrophysics Data System (ADS)

Carreto, José I.; Montoya, Nora G.; Carignan, Mario O.; Akselman, Rut; Acha, E. Marcelo; Derisio, Carla

2016-08-01

The aim of this study was to investigate the biotic and abiotic factors controlling the spring phytoplankton blooms at the Patagonian shelf-break front (PSBF). Using a CHEMTAX analysis of HPLC pigment data and other methods, the biomass and spatial variability of plankton communities were studied in four sections (39-48°S) across the PSBF during October 2005. Environmental factors and the biomass and composition of plankton communities exhibited a marked spatial heterogeneity. The latitudinal and cross-shelf progression in the timing of the spring bloom initiation and the nutritive properties of the water masses (Subantarctic Shelf Waters and Malvinas Current Waters) seemed to be the key factors. Three plankton regions were distinguished: (a) Outer shelf (OS), (b) Shelf-break front (SBF) and (c) Malvinas Current (MC). At the highly stratified OS region, the post-bloom community showed low-biomasshigh-phytoplankton diversity formed mainly by small cells (haptophytes 30-62%, diatoms 17-49%, chlorophytes 0-34%, and prasinophytes 0-21% of total Chl a). High amounts of degraded fucoxanthin were found associated with the heterotrophic dinoflagellate, Protoperidinium capurroi. Grazing by this microheterotroph on the diatom population seemed to be the most important factor for the spring bloom decay at the OS. A remarkable quasi monospecific bloom (∼90%) of a nanodiatom (Thalassiosira bioculata var. raripora) associated with high Chl a (up to 20 mg m-3) occurred along (∼1000 km) the SBF and in the most northern extension of the MC. In the southern region, the bloom was developed under absent or incipient density stratification, increasing solar irradiance, high nitrate and phosphate availability, and low numbers of phytoplankton grazers. The average mixedlayer PAR irradiance (<2.0 mol quanta PAR m-2 d-1) and Si:N ratios (<0.2) were low, suggesting a diatom population limited by light and under progressive silicate limitation. The more stratified northern region of the SBF showed a later stage of the bloom development, but the large population of diatoms under Si limitation was not in senescence and losses from microzooplankton grazing were minor. The observed high proportion of Chl a below a shallow upper mixed layer (up to 85%) could directly reach the bed, favoring the development of epibenthic communities and the formation of seed diatom banks and organic iron-rich sediments. The upwelling along the SBF provides a large source of macronutrients and probably the dissolved iron needed to sustain the intense diatom bloom, but also diatom resting stages that could act as seeds for the next spring bloom. The macronutrient-rich MC region showed low chlorophyll (Chl a < 0.8 mg m-3) and a highly diverse phytoplankton community, mainly composed of small cells (diatoms 20-70%, haptophytes 20-40%, chlorophytes 2-25%, prasinophytes 2-18%, and cryptophytes 3-12% of total Chl a).

Overflow control valve

DOEpatents

Hundal, Rolv; Kessinger, Boyd A.; Parlak, Edward A.

1984-07-24

An overflow control valve for use in a liquid sodium coolant pump tank which valve can be extended to create a seal with the pump tank wall or retracted to break the seal thereby accommodating valve removal. An actuating shaft which controls valve disc position also has cams which bear on roller surfaces to force retraction of a sliding cylinder against spring tension to retract the cylinder from sealing contact with the pump tank.

Frost injury to bitterbrush in eastern California

Treesearch

R. S. Smith; R. F. Scharpf; E. R. Schneegas

1965-01-01

Widespread dieback of Purshia tridentata, on the Inyo National Forest in eastern California in the spring of 1964, was caused by a severe 3-day frost with daily minimums down to 13°F. An unusually warm 9-day period-with temperatures up to 70°F., which preceded the frost by a week, had induced the bitterbrush to break dormancy and start shoot elongation when the frost...

Phenology of slippery bark and common foliar diseases

Treesearch

Kevin T. Smith

2013-01-01

As mud season gives way to spring in New England, the pace of plant development quickens. We see that from the visual cues of plant phenology, the sequence and timing of biological events. The big early season events are upon us as the maple sap has run, buds swell, bud dormancy breaks, and leaves and flowers emerge. This is a good time for arborists to dust off their...

Selected Papers from the Spring 1993 Breivogel Conference at the University of Florida on Alternative/Portfolio Assessment.

ERIC Educational Resources Information Center

Vernetson, Theresa, Ed.

1993-01-01

This edition of the "Research Bulletin" is a compilation of papers presented at the annual William F. Breivogel Conference in 1993. The conference theme was alternative and portfolio assessment. Papers were grouped into assessment in general, portfolio assessment, and alternative assessments and curriculum questions. The selected papers…

The Sea Floor: A Living Learning Residential Community

NASA Astrophysics Data System (ADS)

Guentzel, J. L.; Rosch, E.; Stoughton, M. A.; Bowyer, R.; Mortensen, K.; Smith, M.

2016-02-01

Living learning communities are collaborations between university housing and academic departments designed to enhance the overall student experience by integrating classroom/laboratory learning, student life and extracurricular activities. At Coastal Carolina University, the residential community associated with the Marine Science program is known as the Sea Floor. Students selected to become members of the Sea Floor remain "in residence" for two consecutive semesters. These students are first-time freshman that share a common course connection. This course is usually Introduction to Marine Science (MSCI 111) or MSCI 399s, which are one credit field/laboratory centered internships. The common course connection is designed so residents can establish and maintain an educational dialog with their peers. Activities designed to enhance the students' networking skills and educational and social development skills include monthly lunches with marine science faculty and dinner seminars with guest speakers from academia, industry and government. Additionally, each semester several activities outside the classroom are planned so that students can more frequently interact with themselves and their faculty and staff partners. These activities include field trips to regional aquariums, local boat trips that include water sample collection and analysis, and an alternative spring break trip to the Florida Keys to study the marine environment firsthand. The resident advisor that supervises the Sea Floor is usually a sophomore or junior marine science major. This provides the residents with daily communication and mentoring from a marine science major that is familiar with the marine science program and residence life. Assessment activities include: a university housing community living survey, student interest housing focus groups, fall to spring and fall to fall retention, and evaluation of program advisors and program activities.

Transportation Observations, Considerations, and Recommendations for Spring Mountains National Recreation Area Provided by the Interagency Transportation Assistance Group (TAG) /Alternative Transportation in Parks and Public Lands (ATPPL) Program Las Vega

DOT National Transportation Integrated Search

2006-12-04

A field investigation of the current transportation infrastructure and operations at Humboldt-Toiyabe National Forest (H-TNF): Spring Mountains National Recreation Area (SMNRA or NRA) by the inter-agency Transportation Assistance Group (TAG) was cond...

Resources for Hope: Ideas for Alternatives from Heterodox Higher Education Institutions

ERIC Educational Resources Information Center

Butcher, Catherine Norma

2017-01-01

This report describes my field visits to Berea and Deep Springs Colleges in the U.S.A. and explores their forms of ownership/control, governance, financing and organisational structure. Berea and Deep Springs are small, liberal arts colleges, distinctive in American higher education, in which students actively participate in a spirit of democracy.…

Digital-model analysis of the effects of water-use alternatives on spring discharges Gooding and Jerome Counties, Idaho

USGS Publications Warehouse

Moreland, Joe A.

1976-01-01

Springs discharging from the Snake Plain aquifer contribute approximately 6,000 cubic feet per second (170 cubic metres per second) to flow in the Snake River between Milner and King Hill. Before irrigation began on the Snake River Plain north and east of the springs, total spring discharge was about 4,200 cubic feet per second (120 cubic meters per second). Increasing amounts of irrigated acreage from the early 1900's to the mid-1940's contributed more irrigation-return water to the aquifer resulting in increased discharge at the springs. Maximum discharge of about 6,800 cubic feet per second (190 cubic metres per second) occurred during the late 1940's and early 1950's. Increased use of pumped ground water for irrigation and changing irrigation practices have since resulted in a decline in spring discharge.

XRCC1 suppresses somatic hypermutation and promotes alternative nonhomologous end joining in Igh genes.

PubMed

Saribasak, Huseyin; Maul, Robert W; Cao, Zheng; McClure, Rhonda L; Yang, William; McNeill, Daniel R; Wilson, David M; Gearhart, Patricia J

2011-10-24

Activation-induced deaminase (AID) deaminates cytosine to uracil in immunoglobulin genes. Uracils in DNA can be recognized by uracil DNA glycosylase and abasic endonuclease to produce single-strand breaks. The breaks are repaired either faithfully by DNA base excision repair (BER) or mutagenically to produce somatic hypermutation (SHM) and class switch recombination (CSR). To unravel the interplay between repair and mutagenesis, we decreased the level of x-ray cross-complementing 1 (XRCC1), a scaffold protein involved in BER. Mice heterozygous for XRCC1 showed a significant increase in the frequencies of SHM in Igh variable regions in Peyer's patch cells, and of double-strand breaks in the switch regions during CSR. Although the frequency of CSR was normal in Xrcc1(+/-) splenic B cells, the length of microhomology at the switch junctions decreased, suggesting that XRCC1 also participates in alternative nonhomologous end joining. Furthermore, Xrcc1(+/-) B cells had reduced Igh/c-myc translocations during CSR, supporting a role for XRCC1 in microhomology-mediated joining. Our results imply that AID-induced single-strand breaks in Igh variable and switch regions become substrates simultaneously for BER and mutagenesis pathways.

Short break and emergency respite care: what options for young people with life-limiting conditions?

PubMed

Mitchell, Tracy K; Knighting, Katherine; O'Brien, Mary R; Jack, Barbara A

2016-02-01

Service providers face difficult decisions about how best to develop services for the increasing numbers of young people with life-limiting conditions who require palliative care. To explore alternative short break and emergency respite care options to children's hospice care. A two-phase evaluation with young people, families and professionals. Phase 1: qualitative semi-structured interviews and focus groups (n=53). Phase 2: mixed-method survey (n=82), qualitative findings only. There were few, or no, appropriate short break and emergency respite care alternatives when children's hospice care was not available that can meet the need of young people with life-limiting conditions, creating anxiety for children's hospice users and those leaving the service as a result of reaching transition age or through no longer meeting the children's hospice eligibility criteria. Access to appropriate short break and emergency respite care is required to prevent lifelong negative consequences for young people with life-limiting conditions, their family and society. Research is undoubtedly required to explore the impact and outcomes of children's hospice discharge for young people and their family. Particular attention should be paid to the lack of services for an increasing population making the transition from children's hospices.

An analysis of stream channel cross section technique as a means to determine anthropogenic change in second order streams at the Tenderfoot Creek Experimental Forest, Meagher County, Montana

Treesearch

Jeff Boice

1999-01-01

Five second order tributaries to Tenderfoot Creek were investigated: Upper Tenderfoot Creek, Sun Creek, Spring Park Creek, Bubbling Creek, and Stringer Creek. Second order reaches were initially located on 7.5 minute topographic maps using techniques first applied by Strahler (1952). Reach breaks were determined in the field through visual inspection. Vegetation type (...

The Electrostatic Gavimeter: An Alternative Way of Measuring Gravitational Acceleration

NASA Astrophysics Data System (ADS)

Kashinski, David

2005-03-01

In the past, Earth’s gravitational acceleration g has been measured in many ways, including the use of a pendulum as well as other models involving the use of a mass and a spring. We have designed a new method incorporating a spring with a capacitor and a voltmeter. This capacitor model still uses a hanging mass on a spring, but alters the method of determining the change in position of the spring due to the gravitational acceleration. We relate the change in position to the potential difference across the capacitor needed to cause a discharge through parallel plates. By relating this voltage directly to the gravitaional acceleration,a new method of measuring g is obtained.

An Investigation into Instructor Implementation of Alternative Course Offerings in Education Departments in One Private Liberal Arts University

ERIC Educational Resources Information Center

Miranda, Twyla; Newton, William; Vowell, Julie; Martinez, Carlos

2015-01-01

In order to understand whether a "personal" education found in the mission of a private liberal arts university could be delivered in alternative formats, an investigation into the teaching practice of eight instructors in newly designed alternative delivery courses was conducted during the fall and spring semesters of 2013-2014. The…

Retrofitting and the mu Problem

DOE Office of Scientific and Technical Information (OSTI.GOV)

Green, Daniel; Weigand, Timo; /SLAC /Stanford U., Phys. Dept.

2010-08-26

One of the challenges of supersymmetry (SUSY) breaking and mediation is generating a {mu} term consistent with the requirements of electro-weak symmetry breaking. The most common approach to the problem is to generate the {mu} term through a SUSY breaking F-term. Often these models produce unacceptably large B{mu} terms as a result. We will present an alternate approach, where the {mu} term is generated directly by non-perturtative effects. The same non-perturbative effect will also retrofit the model of SUSY breaking in such a way that {mu} is at the same scale as masses of the Standard Model superpartners. Because themore » {mu} term is not directly generated by SUSY breaking effects, there is no associated B{mu} problem. These results are demonstrated in a toy model where a stringy instanton generates {mu}.« less

Alternative timing of carbaryl treatments for protecting lodgepole pine from mortality attributed to mountain pine beetle

Treesearch

Christopher J. Fettig; A.Steve Munson; Kenneth E. Gibson

2015-01-01

Carbaryl is regarded among the most effective, economically viable, and ecologically-compatible insecticides available for protecting conifers from bark beetle attack in the western United States. Treatments are typically applied in spring prior to initiation of bark beetle flight for that year. We evaluated the efficacy of spring and fall applications for protecting...

Final Environmental Assessment for the Semiannual Joint Integrated Fires Exercises at Avon Park Air Force Range, Florida

DTIC Science & Technology

2006-04-01

spring that would have the potential to create wildfires. 3.11 Grazing Management : All alternatives would have minimal impact to grazing...3.12 Invasive Plant Management : All alternatives would have minimal impact to management . 3.13 Timber Management : All alternatives would have...food and fuel within the local communities. 3.18 Coastal Zone Management : The alternatives would be consistent with the Florida Coastal Zone

High-Resolution Aeromagnetic Survey To Image Shallow Faults, Poncha Springs and Vicinity, Chaffee County, Colorado

USGS Publications Warehouse

Grauch, V.J.S.; Drenth, Benjamin J.

2009-01-01

High-resolution aeromagnetic data were acquired over the town of Poncha Springs and areas to the northwest to image faults, especially where they are concealed. Because this area has known hot springs, faults or fault intersections at depth can provide pathways for upward migration of geothermal fluids or concentrate fracturing that enhances permeability. Thus, mapping concealed faults provides a focus for follow-up geothermal studies. Fault interpretation was accomplished by synthesizing interpretative maps derived from several different analytical methods, along with preliminary depth estimates. Faults were interpreted along linear aeromagnetic anomalies and breaks in anomaly patterns. Many linear features correspond to topographic features, such as drainages. A few of these are inferred to be fault-related. The interpreted faults show an overall pattern of criss-crossing fault zones, some of which appear to step over where they cross. Faults mapped by geologists suggest similar crossing patterns in exposed rocks along the mountain front. In low-lying areas, interpreted faults show zones of west-northwest-, north-, and northwest-striking faults that cross ~3 km (~2 mi) west-northwest of the town of Poncha Springs. More easterly striking faults extend east from this juncture. The associated aeromagnetic anomalies are likely caused by magnetic contrasts associated with faulted sediments that are concealed less than 200 m (656 ft) below the valley floor. The faults may involve basement rocks at greater depth as well. A relatively shallow (<300 m or <984 ft), faulted basement block is indicated under basin-fill sediments just north of the hot springs and south of the town of Poncha Springs.

Chemically Enhanced Trust: Potential Law Enforcement and Military Applications for Oxytocin

DTIC Science & Technology

2007-12-01

Breaking Cooperative Relationships, ed. Diego Gambetta, 213-237. Oxford: Basil Blackwell, 1988, 218. 17 Niklas Luhmann. “Familiarity, Confidence, Trust...Problems and Alternatives.” In Trust: Making and Breaking Cooperative Relationships, ed. Diego Gambetta, 94-107. Oxford: Basil Blackwell, 1988, 95...Relationships, ed. Diego Gambetta, 94-107. Oxford: Basil Blackwell, 1988, 166. 171 Karen S. Cook, Russell Hardin and Margaret Levi. Cooperation Without

Potential effects of groundwater pumping on water levels, phreatophytes, and spring discharges in Spring and Snake Valleys, White Pine County, Nevada, and adjacent areas in Nevada and Utah

USGS Publications Warehouse

Halford, Keith J.; Plume, Russell W.

2011-01-01

Assessing hydrologic effects of developing groundwater supplies in Snake Valley required numerical, groundwater-flow models to estimate the timing and magnitude of capture from streams, springs, wetlands, and phreatophytes. Estimating general water-table decline also required groundwater simulation. The hydraulic conductivity of basin fill and transmissivity of basement-rock distributions in Spring and Snake Valleys were refined by calibrating a steady state, three-dimensional, MODFLOW model of the carbonate-rock province to predevelopment conditions. Hydraulic properties and boundary conditions were defined primarily from the Regional Aquifer-System Analysis (RASA) model except in Spring and Snake Valleys. This locally refined model was referred to as the Great Basin National Park calibration (GBNP-C) model. Groundwater discharges from phreatophyte areas and springs in Spring and Snake Valleys were simulated as specified discharges in the GBNP-C model. These discharges equaled mapped rates and measured discharges, respectively. Recharge, hydraulic conductivity, and transmissivity were distributed throughout Spring and Snake Valleys with pilot points and interpolated to model cells with kriging in geologically similar areas. Transmissivity of the basement rocks was estimated because thickness is correlated poorly with transmissivity. Transmissivity estimates were constrained by aquifer-test results in basin-fill and carbonate-rock aquifers. Recharge, hydraulic conductivity, and transmissivity distributions of the GBNP-C model were estimated by minimizing a weighted composite, sum-of-squares objective function that included measurement and Tikhonov regularization observations. Tikhonov regularization observations were equations that defined preferred relations between the pilot points. Measured water levels, water levels that were simulated with RASA, depth-to-water beneath distributed groundwater and spring discharges, land-surface altitudes, spring discharge at Fish Springs, and changes in discharge on selected creek reaches were measurement observations. The effects of uncertain distributed groundwater-discharge estimates in Spring and Snake Valleys on transmissivity estimates were bounded with alternative models. Annual distributed groundwater discharges from Spring and Snake Valleys in the alternative models totaled 151,000 and 227,000 acre-feet, respectively and represented 20 percent differences from the 187,000 acre-feet per year that discharges from the GBNP-C model. Transmissivity estimates in the basin fill between Baker and Big Springs changed less than 50 percent between the two alternative models. Potential effects of pumping from Snake Valley were estimated with the Great Basin National Park predictive (GBNP-P) model, which is a transient groundwater-flow model. The hydraulic conductivity of basin fill and transmissivity of basement rock were the GBNP-C model distributions. Specific yields were defined from aquifer tests. Captures of distributed groundwater and spring discharges were simulated in the GBNP-P model using a combination of well and drain packages in MODFLOW. Simulated groundwater captures could not exceed measured groundwater-discharge rates. Four groundwater-development scenarios were investigated where total annual withdrawals ranged from 10,000 to 50,000 acre-feet during a 200-year pumping period. Four additional scenarios also were simulated that added the effects of existing pumping in Snake Valley. Potential groundwater pumping locations were limited to nine proposed points of diversion. Results are presented as maps of groundwater capture and drawdown, time series of drawdowns and discharges from selected wells, and time series of discharge reductions from selected springs and control volumes. Simulated drawdown propagation was attenuated where groundwater discharge could be captured. General patterns of groundwater capture and water-table declines were similar for all scenarios. Simulated drawdowns greater than 1 ft propagated outside of Spring and Snake Valleys after 200 years of pumping in all scenarios.

Can a Double Component Outflow Explain the X-Ray and Optical Lightcurves of Swift Gamma-Ray Bursts?

NASA Technical Reports Server (NTRS)

De Pasquale, Massimiliano; Evans, P.; Oates, S.; Page, M.; Zane, S.; Schady, P.; Breeveld, A.; Holland, S.; Still, M.

2011-01-01

An increasing sample of Gamma-Ray Bursts (GRBs) observed by Swift show evidence of 'chromatic breaks', i.e. breaks that are present in the X-ray but not in the optical. We find that in a significant fraction of these GRB afterglows the X-ray and the optical emission cannot be produced by the same component. We propose that these afterglow lightcurves are the result of a two-component jet, in which both components undergo energy injection for the whole observation and the X-ray break is due to a jet break in the narrow outflow. Bursts with chromatic breaks also explain another surprising finding, the paucity of late achromatic breaks. We propose a model that may explain the behaviour of GRB emission in both X-ray and optical bands. This model can be a radical and noteworthy alternative to the current interpretation for the 'canonical' XRT and UVOT lightcurves, and it bears fundamental implications for GRB physics.

Structural Inventory of Great Basin Geothermal Systems and Definition of Favorable Structural Settings

DOE Data Explorer

Faulds, James E.

2013-12-31

Over the course of the entire project, field visits were made to 117 geothermal systems in the Great Basin region. Major field excursions, incorporating visits to large groups of systems, were conducted in western Nevada, central Nevada, northwestern Nevada, northeastern Nevada, east‐central Nevada, eastern California, southern Oregon, and western Utah. For example, field excursions to the following areas included visits of multiple geothermal systems: - Northwestern Nevada: Baltazor Hot Spring, Blue Mountain, Bog Hot Spring, Dyke Hot Springs, Howard Hot Spring, MacFarlane Hot Spring, McGee Mountain, and Pinto Hot Springs in northwest Nevada. - North‐central to northeastern Nevada: Beowawe, Crescent Valley (Hot Springs Point), Dann Ranch (Hand‐me‐Down Hot Springs), Golconda, and Pumpernickel Valley (Tipton Hot Springs) in north‐central to northeast Nevada. - Eastern Nevada: Ash Springs, Chimney Hot Spring, Duckwater, Hiko Hot Spring, Hot Creek Butte, Iverson Spring, Moon River Hot Spring, Moorman Spring, Railroad Valley, and Williams Hot Spring in eastern Nevada. - Southwestern Nevada‐eastern California: Walley’s Hot Spring, Antelope Valley, Fales Hot Springs, Buckeye Hot Springs, Travertine Hot Springs, Teels Marsh, Rhodes Marsh, Columbus Marsh, Alum‐Silver Peak, Fish Lake Valley, Gabbs Valley, Wild Rose, Rawhide‐ Wedell Hot Springs, Alkali Hot Springs, and Baileys/Hicks/Burrell Hot Springs. - Southern Oregon: Alvord Hot Spring, Antelope Hot Spring‐Hart Mountain, Borax Lake, Crump Geyser, and Mickey Hot Spring in southern Oregon. - Western Utah: Newcastle, Veyo Hot Spring, Dixie Hot Spring, Thermo, Roosevelt, Cove Fort, Red Hill Hot Spring, Joseph Hot Spring, Hatton Hot Spring, and Abraham‐Baker Hot Springs. Structural controls of 426 geothermal systems were analyzed with literature research, air photos, google‐Earth imagery, and/or field reviews (Figures 1 and 2). Of the systems analyzed, we were able to determine the structural settings of more than 240 sites. However, we found that many “systems” consisted of little more than a warm or hot well in the central part of a basin. Such “systems” were difficult to evaluate in terms of structural setting in areas lacking in geophysical data. Developed database for structural catalogue in a master spreadsheet. Data components include structural setting, primary fault orientation, presence or absence of Quaternary faulting, reservoir lithology, geothermometry, presence or absence of recent magmatism, and distinguishing blind systems from those that have surface expressions. Reviewed site locations for all 426 geothermal systems– Confirmed and/or relocated spring and geothermal sites based on imagery, maps, and other information for master database. Many systems were mislocated in the original database. In addition, some systems that included several separate springs spread over large areas were divided into two or more distinct systems. Further, all hot wells were assigned names based on their location to facilitate subsequent analyses. We catalogued systems into the following eight major groups, based on the dominant pattern of faulting (Figure 1): - Major normal fault segments (i.e., near displacement maxima). - Fault bends. - Fault terminations or tips. - Step‐overs or relay ramps in normal faults. - Fault intersections. - Accommodation zones (i.e., belts of intermeshing oppositely dipping normal faults), - Displacement transfer zones whereby strike‐slip faults terminate in arrays of normal faults. - Transtensional pull‐aparts. These settings form a hierarchal pattern with respect to fault complexity. - Major normal faults and fault bends are the simplest. - Fault terminations are typically more complex than mid‐segments, as faults commonly break up into multiple strands or horsetail near their ends. - A fault intersection is generally more complex, as it generally contains both multiple fault strands and can include discrete di...

Naval War College Review. Volume 66, Number 2, Spring 2013

DTIC Science & Technology

2013-01-01

ring strait to provide trade security. No more than fifty-two nautical miles wide, the bering strait, which separates alaska and russia, was...breaking the tyranny of wind and weather. soon superior navies would be able to enforce blockades in weather fair and foul, making it more dif- ficult for...privateers to slip out of blockaded ports and, even more to the point, making it improbable that captured vessels could be brought safely into

Motivated Forgetting in Early Mathematics: A Proof-of-Concept Study

PubMed Central

Ramirez, Gerardo

2017-01-01

Educators assume that students are motivated to retain what they are taught. Yet, students commonly report that they forget most of what they learn, especially in mathematics. In the current study I ask whether students may be motivated to forget mathematics because of academic experiences threaten the self-perceptions they are committed to maintaining. Using a large dataset of 1st and 2nd grade children (N = 812), I hypothesize that math anxiety creates negative experiences in the classroom that threaten children’s positive math self-perceptions, which in turn spurs a motivation to forget mathematics. I argue that this motivation to forget is activated during the winter break, which in turn reduces the extent to which children grow in achievement across the school year. Children were assessed for math self-perceptions, math anxiety and math achievement in the fall before going into winter break. During the spring, children’s math achievement was measured once again. A math achievement growth score was devised from a regression model of fall math achievement predicting spring achievement. Results show that children with higher math self-perceptions showed reduced growth in math achievement across the school year as a function of math anxiety. Children with lower math interest self-perceptions did not show this relationship. Results serve as a proof-of-concept for a scientific account of motivated forgetting within the context of education. PMID:29255439

Motivated Forgetting in Early Mathematics: A Proof-of-Concept Study.

PubMed

Ramirez, Gerardo

2017-01-01

Educators assume that students are motivated to retain what they are taught. Yet, students commonly report that they forget most of what they learn, especially in mathematics. In the current study I ask whether students may be motivated to forget mathematics because of academic experiences threaten the self-perceptions they are committed to maintaining. Using a large dataset of 1st and 2nd grade children ( N = 812), I hypothesize that math anxiety creates negative experiences in the classroom that threaten children's positive math self-perceptions, which in turn spurs a motivation to forget mathematics. I argue that this motivation to forget is activated during the winter break, which in turn reduces the extent to which children grow in achievement across the school year. Children were assessed for math self-perceptions, math anxiety and math achievement in the fall before going into winter break. During the spring, children's math achievement was measured once again. A math achievement growth score was devised from a regression model of fall math achievement predicting spring achievement. Results show that children with higher math self-perceptions showed reduced growth in math achievement across the school year as a function of math anxiety. Children with lower math interest self-perceptions did not show this relationship. Results serve as a proof-of-concept for a scientific account of motivated forgetting within the context of education.

The Kindles Are Coming: Ereaders and Tablets Are Springing up in Schools--And Librarians Are Leading the Way

ERIC Educational Resources Information Center

Barack, Lauren

2011-01-01

Commonly spearheaded by librarians, Kindle pilot programs are springing up in schools around the country, bringing ereaders to K-12 students, who are cracking the spine, so to speak, on these alternative learning tools. From full adoption of the devices at Clearwater High School in Florida to tentative beta projects, educators are exploring how…

Effect of winter cold duration on spring phenology of the orange tip butterfly, Anthocharis cardamines.

PubMed

Stålhandske, Sandra; Lehmann, Philipp; Pruisscher, Peter; Leimar, Olof

2015-12-01

The effect of spring temperature on spring phenology is well understood in a wide range of taxa. However, studies on how winter conditions may affect spring phenology are underrepresented. Previous work on Anthocharis cardamines (orange tip butterfly) has shown population-specific reaction norms of spring development in relation to spring temperature and a speeding up of post-winter development with longer winter durations. In this experiment, we examined the effects of a greater and ecologically relevant range of winter durations on post-winter pupal development of A. cardamines of two populations from the United Kingdom and two from Sweden. By analyzing pupal weight loss and metabolic rate, we were able to separate the overall post-winter pupal development into diapause duration and post-diapause development. We found differences in the duration of cold needed to break diapause among populations, with the southern UK population requiring a shorter duration than the other populations. We also found that the overall post-winter pupal development time, following removal from winter cold, was negatively related to cold duration, through a combined effect of cold duration on diapause duration and on post-diapause development time. Longer cold durations also lead to higher population synchrony in hatching. For current winter durations in the field, the A. cardamines population of southern UK could have a reduced development rate and lower synchrony in emergence because of short winters. With future climate change, this might become an issue also for other populations. Differences in winter conditions in the field among these four populations are large enough to have driven local adaptation of characteristics controlling spring phenology in response to winter duration. The observed phenology of these populations depends on a combination of winter and spring temperatures; thus, both must be taken into account for accurate predictions of phenology.

Development of high energy micro-tomography system at SPring-8

NASA Astrophysics Data System (ADS)

Uesugi, Kentaro; Hoshino, Masato

2017-09-01

A high energy X-ray micro-tomography system has been developed at BL20B2 in SPring-8. The available range of the energy is between 20keV and 113keV with a Si (511) double crystal monochromator. The system enables us to image large or heavy materials such as fossils and metals. The X-ray image detector consists of visible light conversion system and sCMOS camera. The effective pixel size is variable by changing a tandem lens between 6.5 μm/pixel and 25.5 μm/pixel discretely. The format of the camera is 2048 pixels x 2048 pixels. As a demonstration of the system, alkaline battery and a nodule from Bolivia were imaged. A detail of the structure of the battery and a female mold Trilobite were successfully imaged without breaking those fossils.

Developmental Pathways from Childhood Aggression-Disruptiveness, Chronic Peer Rejection and Deviant Friendships to Early-Adolescent Rule Breaking

PubMed Central

Ettekal, Idean; Ladd, Gary W.

2015-01-01

Childhood aggression-disruptiveness, chronic peer rejection, and deviant friendships were examined as predictors of early-adolescent rule breaking behaviors. Using a sample of 383 children (193 girls and 190 boys) who were followed from ages 6 to 14, peer rejection trajectories were identified and incorporated into a series of alternative models to assess how chronic peer rejection and deviant friendships mediate the association between stable childhood aggression-disruptiveness and early-adolescent rule breaking. There were multiple mediated pathways to rule breaking that included both behavioral and relational risk factors and findings were consistent for boys and girls. Results have implications for better understanding the influence of multiple social processes in the continuity of antisocial behaviors from middle childhood to early adolescence. PMID:25403544

Determination of Stress-Corrosion Cracking in Aluminum-Lithium Alloy ML377

NASA Technical Reports Server (NTRS)

Valek, Bryan C.

1995-01-01

The use of aluminum-lithium alloys for aerospace applications is currently being studied at NASA Langley Research Center's Metallic Materials Branch. The alloys in question will operate under stress in a corrosive environment. These conditions are ideal for the phenomena of Stress-Corrosion Cracking (SCC) to occur. The test procedure for SCC calls for alternate immersion and breaking load tests. These tests were optimized for the lab equipment and materials available in the Light Alloy lab. Al-Li alloy ML377 specimens were then subjected to alternate immersion and breaking load tests to determine residual strength and resistance to SCC. Corrosion morphology and microstructure were examined under magnification. Data shows that ML377 is highly resistant to stress-corrosion cracking.

Guide to Alternative Mortgage Instruments. Teachers Instructional Packet, TIP No. 4, Spring 1985.

ERIC Educational Resources Information Center

Texas A and M Univ., College Station. Texas Real Estate Research Center.

Part of a series of classroom aids designed for real estate instructors, this instructional packet was developed to help real estate students understand the various alternative mortgage instruments, including their major advantages and disadvantages. First, an evaluation form for the packet is presented. Next, a summary presentation on four basic…

Heavy Metal Uptake by C. esculentus, S. alterniflora and Agronomic Plants from Contaminated Soils and Sediments.

DTIC Science & Technology

1982-02-28

in March and potted in April. Seed sowing will ta..-e place in mid-May. The species sown will include a grass. wheat, lettuce and radish and C... effects varied. Soe started negativeLy, and became positive; others remained negative ( radish ), and others were positive aLl the time (wheat). ALL...agronomic plants selected were radish (Webb’s French Break- fast), lettuce (Paris White), wheat (spring), red fescue (Merlin) and ryegrass (S24). Each

A Synoptic Climatology of the Elevated Mixed Layer Inversion Over the Southern Great Plains in Spring

DTIC Science & Technology

1991-08-01

offshore PBL flow along Texas coast at initial time (1200 UTC 4 April). Tick marks along the trajectory are used to denote the simulation hour; the...are taken at tornado Gulf Coast event time at closest upper- air station in an upstream direction with respect to mean low-level flow ). All rain... system starts (subdivided by time of day). A sample day was also discussed. 9 break and thermal inversion layer appears. Above the inversion layer

Development of a Subjective Evaluation Tool for Assessing Marksmanship Training Effectiveness

DTIC Science & Technology

2013-01-28

used to break down the marksmanship domain, as presented in the USMC Rifle Marksmanship Manual, into sub-tasks that were converted into training-task... Mangos for his expertise in survey development and, along with Dr. Joseph Chandler, for guidance on the analysis of a complicated data set; Mr. Clarke...alternative to lengthy and resource-demanding training effectiveness evaluations. A task analytic approach was used to break down the marksmanship domain, as

Diminishing Manufacturing Sources and Material Shortages (DMSMS) Guidebook

DTIC Science & Technology

2006-11-01

www.dau.mil/registrar/enroll.aspx DoD Acquisition, Technology, and Logistics (AT&L) Integrated Framework Chart (IFC) lifecycle activities and...ROI) and Break Even Point ( BEP ). Two analysts could look at the same data and generate different outcomes if they use different assumptions or...principal output of the BCA is the Break Even Point ( BEP ), which shows the payback period of an alternative. It is found from a plot of the

A new dry hypothesis for the formation of Martian linear gullies

USGS Publications Warehouse

Diniega, Serina; Hansen, Candice J.; McElwaine, Jim N.; Hugenholtz, C.H.; Dundas, Colin M.; McEwen, Alfred S.; Bourke, Mary C.

2013-01-01

Long, narrow grooves found on the slopes of martian sand dunes have been cited as evidence of liquid water via the hypothesis that melt-water initiated debris flows eroded channels and deposited lateral levées. However, this theory has several short-comings for explaining the observed morphology and activity of these linear gullies. We present an alternative hypothesis that is consistent with the observed morphology, location, and current activity: that blocks of CO2 ice break from over-steepened cornices as sublimation processes destabilize the surface in the spring, and these blocks move downslope, carving out levéed grooves of relatively uniform width and forming terminal pits. To test this hypothesis, we describe experiments involving water and CO2 blocks on terrestrial dunes and then compare results with the martian features. Furthermore, we present a theoretical model of the initiation of block motion due to sublimation and use this to quantitatively compare the expected behavior of blocks on the Earth and Mars. The model demonstrates that CO2 blocks can be expected to move via our proposed mechanism on the Earth and Mars, and the experiments show that the motion of these blocks will naturally create the main morphological features of linear gullies seen on Mars.

Deep simple epicotyl morphophysiological dormancy in seeds of two Viburnum species, with special reference to shoot growth and development inside the seed.

PubMed

Chien, Ching-Te; Chen, Shun-Ying; Tsai, Ching-Chu; Baskin, Jerry M; Baskin, Carol C; Kuo-Huang, Ling-Long

2011-07-01

In seeds with deep simple epicotyl morphophysiological dormancy, warm and cold stratification are required to break dormancy of the radicle and shoot, respectively. Although the shoot remains inside the seed all winter, little is known about its growth and morphological development prior to emergence in spring. The aims of the present study were to determine the temperature requirements for radicle and shoot emergence in seeds of Viburnum betulifolium and V. parvifolium and to monitor growth of the epicotyl, plumule and cotyledons in root-emerged seeds. Fresh and pre-treated seeds of V. betulifolium and V. parvifolium were incubated under various temperature regimes and monitored for radicle and shoot emergence. Growth of the epicotyl and cotyledons at different stages was observed with dissecting and scanning electron microscopes. The optimum temperature for radicle emergence of seeds of both species, either kept continuously at a single regime or exposed to a sequence of regimes, was 20/10 °C. GA(3) had no effect on radicle emergence. Cold stratification (5 °C) was required for shoot emergence. The shoot apical meristem in fresh seeds did not form a bulge until the embryo had grown to the critical length for radicle emergence. After radicle emergence, the epicotyl--plumule and cotyledons grew slowly at 5 and 20/10 °C, and the first pair of true leaves was initiated. However, the shoot emerged only from seeds that received cold stratification. Seeds of V. betulifolium and V. parvifolium have deep simple epicotyl morphophysiological dormancy, C(1b)B (root)-C(3) (epicotyl). Warm stratification was required to break the first part of physiological dormancy (PD), thereby allowing embryo growth and subsequently radicle emergence. Although cold stratification was not required for differentiation of the epicotyl--plumule, it was required to break the second part of PD, thereby allowing the shoot to emerge in spring.

Deep simple epicotyl morphophysiological dormancy in seeds of two Viburnum species, with special reference to shoot growth and development inside the seed

PubMed Central

Chien, Ching-Te; Chen, Shun-Ying; Tsai, Ching-Chu; Baskin, Jerry M.; Baskin, Carol C.; Kuo-Huang, Ling-Long

2011-01-01

Background and Aims In seeds with deep simple epicotyl morphophysiological dormancy, warm and cold stratification are required to break dormancy of the radicle and shoot, respectively. Although the shoot remains inside the seed all winter, little is known about its growth and morphological development prior to emergence in spring. The aims of the present study were to determine the temperature requirements for radicle and shoot emergence in seeds of Viburnum betulifolium and V. parvifolium and to monitor growth of the epicotyl, plumule and cotyledons in root-emerged seeds. Methods Fresh and pre-treated seeds of V. betulifolium and V. parvifolium were incubated under various temperature regimes and monitored for radicle and shoot emergence. Growth of the epicotyl and cotyledons at different stages was observed with dissecting and scanning electron microscopes. Key Results The optimum temperature for radicle emergence of seeds of both species, either kept continuously at a single regime or exposed to a sequence of regimes, was 20/10 °C. GA3 had no effect on radicle emergence. Cold stratification (5 °C) was required for shoot emergence. The shoot apical meristem in fresh seeds did not form a bulge until the embryo had grown to the critical length for radicle emergence. After radicle emergence, the epicotyl–plumule and cotyledons grew slowly at 5 and 20/10 °C, and the first pair of true leaves was initiated. However, the shoot emerged only from seeds that received cold stratification. Conclusions Seeds of V. betulifolium and V. parvifolium have deep simple epicotyl morphophysiological dormancy, C1bB (root)–C3 (epicotyl). Warm stratification was required to break the first part of physiological dormancy (PD), thereby allowing embryo growth and subsequently radicle emergence. Although cold stratification was not required for differentiation of the epicotyl–plumule, it was required to break the second part of PD, thereby allowing the shoot to emerge in spring. PMID:21562028

Airpower Projection in the Anti-Access/Area Denial Environment: Dispersed Operations

DTIC Science & Technology

2015-02-01

Raptor Case Study.....................................................................6 Risks to Dispersed Operations...project airpower, this paper breaks down a case study of the Rapid Raptor concept. The risks with executing a dispersed model are analyzed and mitigation...will force leaders to look at alternative ways to project power. Alternative Option: Rapid Raptor Case Study The ability to defend forward operating

Making and Breaking the Rules: Lexical Creativity in the Alternative Music Scene

ERIC Educational Resources Information Center

Rua, Paula Lopez

2010-01-01

This article delves into the connections between language as a rule-governed system of communication and music as a means to express subcultural ideologies and satisfy collective needs. By resorting to the morphological analysis of a corpus of names of alternative music artists, the article evinces that language is a manipulable code through which…

Getting Rid of Gravity--Alternative Ways of Looking at Trajectories

ERIC Educational Resources Information Center

Dion, Peter W.; Ho, Anthony M. H.

2010-01-01

Problems in projectile motion are a time-honored staple of high school and even first-year university physics. They can become confusing for some students, yet boring for the stronger students. Herein we present two alternative approaches to such questions, one we call "breaking down gravity," which makes these questions easier to solve, and the…

REC-1 and HIM-5 distribute meiotic crossovers and function redundantly in meiotic double-strand break formation in Caenorhabditis elegans.

PubMed

Chung, George; Rose, Ann M; Petalcorin, Mark I R; Martin, Julie S; Kessler, Zebulin; Sanchez-Pulido, Luis; Ponting, Chris P; Yanowitz, Judith L; Boulton, Simon J

2015-09-15

The Caenorhabditis elegans gene rec-1 was the first genetic locus identified in metazoa to affect the distribution of meiotic crossovers along the chromosome. We report that rec-1 encodes a distant paralog of HIM-5, which was discovered by whole-genome sequencing and confirmed by multiple genome-edited alleles. REC-1 is phosphorylated by cyclin-dependent kinase (CDK) in vitro, and mutation of the CDK consensus sites in REC-1 compromises meiotic crossover distribution in vivo. Unexpectedly, rec-1; him-5 double mutants are synthetic-lethal due to a defect in meiotic double-strand break formation. Thus, we uncovered an unexpected robustness to meiotic DSB formation and crossover positioning that is executed by HIM-5 and REC-1 and regulated by phosphorylation. © 2015 Chung et al.; Published by Cold Spring Harbor Laboratory Press.

Break-even cost of cloning in genetic improvement of dairy cattle.

PubMed

Dematawewa, C M; Berger, P J

1998-04-01

Twelve different models for alternative progeny-testing schemes based on genetic and economic gains were compared. The first 10 alternatives were considered to be optimally operating progeny-testing schemes. Alternatives 1 to 5 considered the following combinations of technologies: 1) artificial insemination, 2) artificial insemination with sexed semen, 3) artificial insemination with embryo transfer, 4) artificial insemination and embryo transfer with few bulls as sires, and 5) artificial insemination, embryo transfer, and sexed semen with few bulls, respectively. Alternatives 6 to 12 considered cloning from dams. Alternatives 11 and 12 considered a regular progeny-testing scheme that had selection gains (intensity x accuracy x genetic standard deviation) of 890, 300, 600, and 89 kg, respectively, for the four paths. The sums of the generation intervals of the four paths were 19 yr for the first 8 alternatives and 19.5, 22, 29, and 29.5 yr for alternatives 9 to 12, respectively. Rates of genetic gain in milk yield for alternatives 1 to 5 were 257, 281, 316, 327, and 340 kg/yr, respectively. The rate of gain for other alternatives increased as number of clones increased. The use of three records per clone increased both accuracy and generation interval of a path. Cloning was highly beneficial for progeny-testing schemes with lower intensity and accuracy of selection. The discounted economic gain (break-even cost) per clone was the highest ($84) at current selection levels using sexed semen and three records on clones of the dam. The total cost associated with cloning has to be below $84 for cloning to be an economically viable option.

Interprofessional teamwork among students in simulated codes: a quasi-experimental study.

PubMed

Garbee, Deborah D; Paige, John; Barrier, Kendra; Kozmenko, Valeriy; Kozmenko, Lyubov; Zamjahn, John; Bonanno, Laura; Cefalu, Jean

2013-01-01

The purpose of this study was to evaluate the efficacy of using crisis resource management (CRM) principles and high-fidelity human patient simulation (HFHPS) for interprofessional (IP) team training of students from undergraduate nursing, nurse anesthesia, medical, and respiratory therapy. IP education using simulation-based training has the potential to transform education by improving teamwork and communication and breaking down silos in education. This one-year study used a quasi-experimental design to evaluate students' acquisition and retention of teamwork and communication skills. A convenience sample consisted of 52 students in the fall semester, with 40 students returning in the spring. Mean scores increased after training, and skills were retained fairly well. Any loss was regained with repeat training in the spring. The results suggest that using CRM and HFHPS is an effective pedagogy for teaching communication and teamwork skills to IP student teams.

Aircraft-mounted crash-activated transmitter device

NASA Technical Reports Server (NTRS)

Manoli, R.; Ulrich, B. R. (Inventor)

1976-01-01

An aircraft crash location transmitter tuned to transmit on standard emergency frequencies is reported that is shock mounted in a sealed circular case atop the tail of an aircraft by means of a shear pin designed to fail under a G loading associated with a crash situation. The antenna for the transmitter is a metallic spring blade coiled like a spiral spring around the outside of the circular case. A battery within the case for powering the transmitter is kept trickle charged from the electrical system of the aircraft through a break away connector on the case. When a crash occurs, the resultant ejection of the case from the tail due to a failure of the shear pin releases the free end of the antenna which automatically uncoils. The accompanying separation of the connector effects closing of the transmitter key and results in commencement of transmission.

Influence of adhesive rough surface contact on microswitches

NASA Astrophysics Data System (ADS)

Wu, Ling; Rochus, V.; Noels, L.; Golinval, J. C.

2009-12-01

Stiction is a major failure mode in microelectromechanical systems (MEMS). Undesirable stiction, which results from contact between surfaces, threatens the reliability of MEMS severely as it breaks the actuation function of MEMS switches, for example. Although it may be possible to avoid stiction by increasing restoring forces using high spring constants, it follows that the actuation voltage has also to be increased significantly, which reduces the efficiency. In our research, an electrostatic-structural analysis is performed to estimate the proper design range of the equivalent spring constant, which is the main factor of restoring force in MEMS switches. The upper limit of equivalent spring constant is evaluated based on the initial gap width, the dielectric thickness, and the expected actuation voltage. The lower limit is assessed on the value of adhesive forces between the two contacting rough surfaces. The MEMS devices studied here are assumed to work in a dry environment. In these operating conditions only the van der Waals forces have to be considered for adhesion. A statistical model is used to simulate the rough surface, and the Maugis's model is combined with Kim's expansion to calculate adhesive forces. In the resulting model, the critical value of the spring stiffness depends on the material and surface properties, such as the elastic modulus, surface energy, and surface roughness. The aim of this research is to propose simple rules for design purposes.

Locking hinge

NASA Technical Reports Server (NTRS)

Wesselski, Clarence J. (Inventor)

1988-01-01

The space station configuration currently studied utilizes structures which require struts to be hinged in the middle in the stowed mode and locked into place in the deployed mode. Since there are hundreds of hinges involved, it is necessary that they have simple, positive locking features with a minimum of joint looseness or slack. This invention comprises two similar housings hinged together with a spring loaded locking member which assists in making as well as breaking the lock. This invention comprises a bracket hinge and bracket members with a spring biased and movable locking member. The locking or latch member has ear parts received in locking openings where wedging surfaces on the ear parts cooperate with complimentary surfaces on the bracket members for bringing the bracket members into a tight end-to-end alignment when the bracket members are in an extended position. When the locking member is moved to an unlocking position, pivoting of the hinge about a pivot pin automatically places the locking member to retain the locking member in an unlocked position. In pivoting the hinge from an extended position to a folded position, longitudinal spring members are placed under tension over annular rollers so that the spring tension in a folded position assists in return of the hinge from a folded to an extended position. Novelty lies in the creation of a locking hinge which allows compact storage and easy assembly of structural members having a minimal number of parts.

In Silico Reconstitution of Actin-Based Symmetry Breaking and Motility

PubMed Central

Dayel, Mark J.; Akin, Orkun; Landeryou, Mark; Risca, Viviana; Mogilner, Alex; Mullins, R. Dyche

2009-01-01

Eukaryotic cells assemble viscoelastic networks of crosslinked actin filaments to control their shape, mechanical properties, and motility. One important class of actin network is nucleated by the Arp2/3 complex and drives both membrane protrusion at the leading edge of motile cells and intracellular motility of pathogens such as Listeria monocytogenes. These networks can be reconstituted in vitro from purified components to drive the motility of spherical micron-sized beads. An Elastic Gel model has been successful in explaining how these networks break symmetry, but how they produce directed motile force has been less clear. We have combined numerical simulations with in vitro experiments to reconstitute the behavior of these motile actin networks in silico using an Accumulative Particle-Spring (APS) model that builds on the Elastic Gel model, and demonstrates simple intuitive mechanisms for both symmetry breaking and sustained motility. The APS model explains observed transitions between smooth and pulsatile motion as well as subtle variations in network architecture caused by differences in geometry and conditions. Our findings also explain sideways symmetry breaking and motility of elongated beads, and show that elastic recoil, though important for symmetry breaking and pulsatile motion, is not necessary for smooth directional motility. The APS model demonstrates how a small number of viscoelastic network parameters and construction rules suffice to recapture the complex behavior of motile actin networks. The fact that the model not only mirrors our in vitro observations, but also makes novel predictions that we confirm by experiment, suggests that the model captures much of the essence of actin-based motility in this system. PMID:19771152

Flow and turbulence structure in a hypertidal estuary with the world's biggest tidal bore

NASA Astrophysics Data System (ADS)

Tu, Junbiao; Fan, Daidu

2017-04-01

Turbulent and flow structure associated with breaking tidal bores are deliberately investigated on the basis of field measurements. High-resolution velocity and hydrographic data are collected in the middle Qiantang Estuary by a vertical array of acoustic Doppler velocimeters and optical backscatter sensors, collaborated with a bottom-mounted acoustic Doppler current profiler. Besides obvious variations in diurnal and spring-neap tidal cycles, the estuarine dynamics is featured by extreme asymmetry in flood and ebb tides. The flood tide is abnormally accelerated to generate tidal bores at the first 10 min or more, with breaking or undular configurations at the front. The occurrence of peak flow velocity, turbulent kinetic energy (TKE), and TKE dissipation rate (ɛ) is definitely associated with breaking bores, with their values several times to 2 orders of magnitude larger than the corresponding secondary peak values during the maximum ebb flows. Flow and turbulence dynamics are significantly affected by the tidal-bore Froude number. A sandwich ɛ structure is clear exhibited with the maximum value at the surface, secondary maximum near the bed, and the minimum at the intermediate. Dual TKE sources are indicated by an approximate local balance between shear production and dissipation near the bottom, and a top-down TKE dissipation using the modified Froude scaling in the vertical water column. The highly elevated dissipation by breaking bores is comparable to that by intense breaking waves in the surf zone, and the former potentially penetrates the entire water column to produce extreme sediment-resuspension events in combination with intense bottom shear stress.

Wave breaking induced surface wakes and jets observed during a bora event

NASA Astrophysics Data System (ADS)

Jiang, Qingfang; Doyle, James D.

2005-09-01

An observational and modeling study of a bora event that occurred during the field phase of the Mesoscale Alpine Programme is presented. Research aircraft in-situ measurements and airborne remote-sensing observations indicate the presence of strong low-level wave breaking and alternating surface wakes and jets along the Croatian coastline over the Adriatic Sea. The observed features are well captured by a high-resolution COAMPS simulation. Analysis of the observations and modeling results indicate that the long-extending wakes above the boundary layer are induced by dissipation associated with the low-level wave breaking, which locally tends to accelerate the boundary layer flow beneath the breaking. Farther downstream of the high peaks, a hydraulic jump occurs in the boundary layer, which creates surface wakes. Downstream of lower-terrain (passes), the boundary layer flow stays strong, resembling supercritical flow.

West Florida shelf circulation and temperature budget for the 1999 spring transition

USGS Publications Warehouse

He, Ruoying; Weisberg, Robert H.

2002-01-01

Mid-latitude continental shelves undergo a spring transition as the net surface heat flux changes from cooling to warming. Using in situ data and a numerical circulation model we investigate the circulation and temperature budget on the West Florida Continental Shelf (WFS) for the spring transition of 1999. The model is a regional adaptation of the primitive equation, Princeton Ocean Model forced by NCEP reanalysis wind and heat flux fields and by river inflows. Based on agreements between the modeled and observed fields we use the model to draw inferences on how the surface momentum and heat fluxes affect the seasonal and synoptic scale variability. We account for a strong southeastward current at mid-shelf by the baroclinic response to combined wind and buoyancy forcing, and we show how this local forcing leads to annually occurring cold and low salinity tongues. Through term-by-term analyses of the temperature budget we describe the WFS temperature evolution in spring. Heat flux largely controls the seasonal transition, whereas ocean circulation largely controls the synoptic scale variability. These two processes, however, are closely linked. Bottom topography and coastline geometry are important in generating regions of convergence and divergence. Rivers contribute to the local hydrography and are important ecologically. Along with upwelling, river inflows facilitate frontal aggregation of nutrients and the spring formation of a high concentration chlorophyll plume near the shelf break (the so-called ‘Green River’) coinciding with the cold, low salinity tongues. These features originate by local, shelf-wide forcing; the Loop Current is not an essential ingredient.

Is most of the Tommotian missing in the White-Inyo region eastern California

DOE Office of Scientific and Technical Information (OSTI.GOV)

Corsetti, F.A.

Integration of carbon-isotope chemostratigraphic data with trace fossil assemblages suggests that a significant hiatus may be present within the Lower Member of the Deep Spring Formation, potentially impacting the placement of the Neoproterozoic-Cambrian boundary in eastern California and western Nevada. A positive carbon-isotopic excursion of 4% PDB is present in the lowermost Lower Deep Spring, and is associated with Zone 1 trace fossils (latest Vendian) and small shelly fossils of disputed age (latest Proterozoic or Tommotian). A negative isotopic excursion is observed throughout the remaining Deep Spring Formation, and is associated with Zone 3 trace fossils (latest Tommotian-Atdabanian in age).more » The positive excursion in the lowermost Deep Spring is tentatively correlated with the pronounced isotopic maximum in the latest Vendian (possibly Nemakit-Daldyn) of the Siberian Platform (cycle 1 of Kirshvink et al., 1991). The negative excursion is correlated with a similar trend in the latest Tommotian-Atdabanian of the Siberian Platform (cycle 4 of Kirshvink et al., 1991). Thus, a hiatus, potentially encompassing most of the Tommotian, is postulated to be present within the Lower Member of the Deep Spring Formation. Although the fossil and isotopic data are consistent with the presence of a break in the section, sedimentological field evidence for the hiatus is somewhat cryptic. The recognition of this hiatus may impact the global significance of the presumed Tommotian small shelly fossils of the White-Inyo region, as well as the placement of the Neoproterozoic-Cambrian boundary in this sequence.« less

The Dynamic Characteristic and Hysteresis Effect of an Air Spring

NASA Astrophysics Data System (ADS)

Löcken, F.; Welsch, M.

2015-02-01

In many applications of vibration technology, especially in chassis, air springs present a common alternative to steel spring concepts. A design-independent and therefore universal approach is presented to describe the dynamic characteristic of such springs. Differential and constitutive equations based on energy balances of the enclosed volume and the mountings are given to describe the nonlinear and dynamic characteristics. Therefore all parameters can be estimated directly from physical and geometrical properties, without parameter fitting. The numerically solved equations fit very well to measurements of a passenger car air spring. In a second step a simplification of this model leads to a pure mechanical equation. While in principle the same parameters are used, just an empirical correction of the effective heat transfer coefficient is needed to handle some simplification on this topic. Finally, a linearization of this equation leads to an analogous mechanical model that can be assembled from two common spring- and one dashpot elements in a specific arrangement. This transfer into "mechanical language" enables a system description with a simple force-displacement law and a consideration of the nonobvious hysteresis and stiffness increase of an air spring from a mechanical point of view.

Pacific Northwest Condiment Yellow Mustard (Sinapis alba L.) Grower Guide: 2000-2002

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, J.; Davis, J. B.; Esser, A.

2005-07-01

This report is a grower guide for yellow mustard. Yellow mustard (Sinapis alba L.), synonymous with white mustard, is a spring annual crop and well adapted to hot, dry growing conditions. It has shown potential as an alternative crop in rotations with small grain cereals and has fewer limitations compared to other traditional alternative crops.

Alternative Observation Tools for the Scope of Contemporary Education Supervision: An Action Research

ERIC Educational Resources Information Center

Kuru Cetin, Saadet

2018-01-01

In this study, in-class lesson observations were made with volunteer teachers working in primary and secondary schools using alternative observation tools regarding the scope of contemporary educational supervision. The study took place during the fall and spring semesters of the 2015-2016 and 2016-2017 academic years and the class observations…

49 CFR 236.2 - Grounds.

Code of Federal Regulations, 2011 CFR

2011-10-01

... circuit, except circuits which include any track rail and except the common return wires of single-wire, single-break, signal control circuits using a grounded common, and alternating current power distribution...

49 CFR 236.2 - Grounds.

Code of Federal Regulations, 2013 CFR

2013-10-01

... circuit, except circuits which include any track rail and except the common return wires of single-wire, single-break, signal control circuits using a grounded common, and alternating current power distribution...

49 CFR 236.2 - Grounds.

Code of Federal Regulations, 2012 CFR

2012-10-01

... circuit, except circuits which include any track rail and except the common return wires of single-wire, single-break, signal control circuits using a grounded common, and alternating current power distribution...

Methods for analysis of cracks in three-dimensional solids

NASA Technical Reports Server (NTRS)

Raju, I. S.; Newman, J. C., Jr.

1984-01-01

Various analytical and numerical methods used to evaluate the stress intensity factors for cracks in three-dimensional (3-D) solids are reviewed. Classical exact solutions and many of the approximate methods used in 3-D analyses of cracks are reviewed. The exact solutions for embedded elliptic cracks in infinite solids are discussed. The approximate methods reviewed are the finite element methods, the boundary integral equation (BIE) method, the mixed methods (superposition of analytical and finite element method, stress difference method, discretization-error method, alternating method, finite element-alternating method), and the line-spring model. The finite element method with singularity elements is the most widely used method. The BIE method only needs modeling of the surfaces of the solid and so is gaining popularity. The line-spring model appears to be the quickest way to obtain good estimates of the stress intensity factors. The finite element-alternating method appears to yield the most accurate solution at the minimum cost.

An application of deviance regulation theory to reduce alcohol-related problems among college women during spring break.

PubMed

Dvorak, Robert D; Kramer, Matthew P; Stevenson, Brittany L; Sargent, Emily M; Kilwein, Tess M

2017-05-01

Spring break (SB) can lead to heavy episodic drinking and increased alcohol-related risks. This may be especially relevant for women. The current study utilized deviance regulation theory to increase the use of protective behavioral strategies (PBSs) among female college students on SB. Female college students going on SB (n = 62) completed a screening, a pre-SB intervention (where they were randomly assigned to receive either a positively or negatively framed message about individuals who do or do not use PBS), and a post-SB assessment that provided alcohol and PBS use data for each day of SB (n = 620 person-days). Data were analyzed using a multilevel structural equation model. In the negative frame, SB PBS use was higher among those who perceived SB PBS norms to be more common on SB relative to non-SB. In the positive frame, SB PBS use was higher among those who perceived SB PBS norms to be less common on SB relative to non-SB. These associations did not result in lower alcohol consumption, but did result in a lower likelihood of experiencing alcohol-related problems during SB. These results suggest that a brief online intervention, that utilizes targeted messages based on normative perceptions of SB PBS use, could be an effective strategy for reducing alcohol-related consequences among college student women during SB. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Alternative Causes of Wide-Spread, Low Concentration Perchlorate Impacts to Groundwater

DTIC Science & Technology

2005-05-05

to as water gels, contain AN in aqueous solution. To aid water resistance and handling, they are thickened and gelled with a gum , such as guar gum ...enamels Curing/Drying Agent Photography Flash powder / oxidizing agent Oxygen generators Burn Rate Modifier Road flares Oxidizing agent...fuse, stars, black powder , a launch tube, main fuse and a lift charge, as shown in Figure 3-1. The break or breaks house the stars in cardboard

Phenological modifications in plants by various edaphic factors.

PubMed

Wielgolaski, F E

2001-11-01

Various mechanical, chemical and physical soil analyses were carried out, in addition to weather observations, for 3 years at several sites along an oceanic-continental gradient in a fjord district in western Norway. All the environmental factors observed were correlated with the spring and a few late-season phenophases of many native and cultivated woody plants and some herbs by simple, linear correlations and by stepwise multiple and partial analyses. Different techniques were used to try and eliminate many intercorrelations between various environmental factors. As expected, air temperature measurements in nearly all analyses from these temperate region districts gave the most significant correlations with the phenology of the plants, the temperature during the night generally being the most important in mainly vegetative periods, e.g. to leaf bud break in spring, and the temperature during the day affecting the more generative phases, such as the period between leaf bud break and flowering. The other environmental factors, however, showed strong variation in correlation significance among the various species studied and also with different phenophases of the same species. Various hypotheses are put forward to explain such variation. Air humidity (including precipitation) and/or soil moisture (including intercorrelated parameters, e.g. soil grain size and bulk density) were relatively often found to be of importance. In the stepwise multiple analyses for leaf bud break of the birch (Betula pubescens), for instance, the amount of precipitation was the second factor to enter the analyses by a positive correlation with the developmental rate, after the most important factor, the night temperature. Positive correlations with a high clay content and bulk density in the soil indicated that high soil moisture is also favourable for early bud break in the birch. Other phenophases that seemed to be favoured by a good water supply were leaf bud break of the bird cherry (Prunus padus) and rowan (Sorbus aucuparia), and flowering of the hazel (Corylus avellana), common lilac (Syringa vulgaris), plum ('Victoria') and currant ('Red Dutch') and also, to some degree, the goat willow (Salix caprea). The amount of ions (P, K, Mg and Ca) often showed negative correlations with the developmental rate, particularly of earlier phenophases of both native and cultivated plants (except for the apple 'Gravenstein' and pear 'Moltke'), possibly, indicating that a high nutrient level delayed plant development. A similar explanation might be given for the observation that high pH in the soil often seemed to delay plant development (leaf bud break of Betula, Sorbus, Syringa and plum, and flowering of Corylus, bluebell (Campanula rotundifolia) and red currant). According to the analyses there seemed to be a tendency for plants that are particularly dependent on warm weather for leaf bud break, e.g. the ash (Fraxinus excelsior), and flowering, e.g. Prunus, pear, apple and, to some degree, the raspberry ('Preussen'), to be less dependent on other environmental factors for their development. For instance, if there were any effects of water for these plants, they were negative for moisture and soil factors intercorrelated with water.

Topology determines force distributions in one-dimensional random spring networks.

PubMed

Heidemann, Knut M; Sageman-Furnas, Andrew O; Sharma, Abhinav; Rehfeldt, Florian; Schmidt, Christoph F; Wardetzky, Max

2018-02-01

Networks of elastic fibers are ubiquitous in biological systems and often provide mechanical stability to cells and tissues. Fiber-reinforced materials are also common in technology. An important characteristic of such materials is their resistance to failure under load. Rupture occurs when fibers break under excessive force and when that failure propagates. Therefore, it is crucial to understand force distributions. Force distributions within such networks are typically highly inhomogeneous and are not well understood. Here we construct a simple one-dimensional model system with periodic boundary conditions by randomly placing linear springs on a circle. We consider ensembles of such networks that consist of N nodes and have an average degree of connectivity z but vary in topology. Using a graph-theoretical approach that accounts for the full topology of each network in the ensemble, we show that, surprisingly, the force distributions can be fully characterized in terms of the parameters (N,z). Despite the universal properties of such (N,z) ensembles, our analysis further reveals that a classical mean-field approach fails to capture force distributions correctly. We demonstrate that network topology is a crucial determinant of force distributions in elastic spring networks.

Topology determines force distributions in one-dimensional random spring networks

NASA Astrophysics Data System (ADS)

Heidemann, Knut M.; Sageman-Furnas, Andrew O.; Sharma, Abhinav; Rehfeldt, Florian; Schmidt, Christoph F.; Wardetzky, Max

2018-02-01

Networks of elastic fibers are ubiquitous in biological systems and often provide mechanical stability to cells and tissues. Fiber-reinforced materials are also common in technology. An important characteristic of such materials is their resistance to failure under load. Rupture occurs when fibers break under excessive force and when that failure propagates. Therefore, it is crucial to understand force distributions. Force distributions within such networks are typically highly inhomogeneous and are not well understood. Here we construct a simple one-dimensional model system with periodic boundary conditions by randomly placing linear springs on a circle. We consider ensembles of such networks that consist of N nodes and have an average degree of connectivity z but vary in topology. Using a graph-theoretical approach that accounts for the full topology of each network in the ensemble, we show that, surprisingly, the force distributions can be fully characterized in terms of the parameters (N ,z ) . Despite the universal properties of such (N ,z ) ensembles, our analysis further reveals that a classical mean-field approach fails to capture force distributions correctly. We demonstrate that network topology is a crucial determinant of force distributions in elastic spring networks.

Employees with Epilepsy

MedlinePlus

... can be exacerbated by light sources such as computer screens or fluorescent lights. Use a flicker-free ... cubicle shield Allow frequent breaks from tasks involving computer Provide alternative light sources: Replace fluorescent lights with ...

Cost benefit analysis of remediation alternatives for controlling the flux of strontium-90 into the Columbia River

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gustafson, F.W.; Todd, M.E.

1993-09-01

The release of large volumes of water to waste disposal cribs at the Hanford Site`s 100-N Area caused contaminants, principally strontium-90, to be carried toward the Columbia River through the groundwater. Since shutdown of the N Reactor, these releases have been discontinued, although small water flows continue to be discharged to the 1325-N crib. Most of the contamination which is now transported to the river is occurring as a result of the natural groundwater movement. The contaminated groundwater at N Springs flows into the river through seeps and springs along the river`s edge. An expedited response action (ERA) has beenmore » proposed to eliminate or restrict the flux of strontium-90 into the river. A cost benefit analysis of potential remedial alternatives was completed that recommends the alternative which best meets given selection criteria prescribed by the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). The methodology used for evaluation, cost analysis, and alternative recommendation is the engineering evaluation/cost analysis (EE/CA). Complete remediation of the contaminated groundwater beneath 100-N Area was not a principal objective of the analysis. The objective of the cost benefit analysis was to identify a remedial alternative that optimizes the degree of benefit produced for the costs incurred.« less

Spring Breaks and Cigarette Tax Noncompliance: Evidence From a New York City College Sample.

PubMed

Consroe, Kimberly; Kurti, Marin; Merriman, David; von Lampe, Klaus

2016-08-01

Estimate cigarette tax noncompliance (tax avoidance and evasion) before and after mid-semester recesses in a New York City college campus, where the majority of students are residents of nearby lower-tax states, using data derived from garbology, an archaeological method that reconstructs patterns of human behavior from discarded materials. We systematically divided the college campus into four geographic areas and established a total of 12 transects (survey lines) and five quadrats (survey spheres) in those areas to encompass 74 outdoor trash cans. Weekly collections of discarded cigarette packs (n = 174) in the four areas during Spring 2012 and 2013 were conducted to quantify the percentage of cigarette packs that were tax noncompliant. Overall, we find that 72.4% of the cigarette packs collected in Spring 2012 and 2013 did not bear the required joint New York City and New York State tax stamp. Additionally, we find that cigarette tax avoidance significantly increased after recesses (mid-March and early April) in Spring 2012 and subsequently declined. We also find that packs with a Virginia tax stamp became more prevalent as time elapsed after each recess. College students practice tax avoidance, drawing on legal purchases from their own home states as the primary source of cheap cigarettes. As stocks decline, some students shift to tax evasion by illegally purchasing cigarettes in New York City that have been bootlegged from low tax states (eg, Virginia). Our study adds to the growing literature on cigarette tax noncompliance (ie, tax avoidance and evasion). First, we provide evidence that college students in our New York City sample avoid the payment of taxes in high tax states by purchasing low taxed cigarettes in their home state. Second, we find that once those sources are depleted, students find access to the black market nearby campus. This black market functions through cigarette tax evasion: the resale of cigarettes purchased in low tax states. Our study suggests that institutions of higher education operating in states with high cigarette taxes and a student body that resides in lower tax states should increase cessation services prior to breaks to discourage bulk purchases of cheap cigarettes. © The Author 2016. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Miniature Internal Combustion Engine-Generator for High Energy Density Portable Power

DTIC Science & Technology

2008-12-01

Operation on JP-8 from cold startup to steady operation has been demonstrated at the 300 W scale. Miniature engine/generators can be acoustically silenced...design that uses a spring for energy storage . MICE is a high Q system, operating at the resonant frequency of the spring-mass system with very low...development • Demonstrated 94% efficiency of 300 W linear alternator • Demonstrated full operation of MICE generator from cold startup to net power output

Water quality of selected springs and public-supply wells, Pine Ridge Indian Reservation, South Dakota, 1992-97

USGS Publications Warehouse

Heakin, Allen J.

2000-01-01

This report presents results of a water-quality study for the Pine Ridge Indian Reservation, South Dakota. The study was a cooperative effort between the U.S. Geological Survey and the Water Resources Department of the Oglala Sioux Tribe. Discharge and water-quality data were collected during 1992-97 for 14 contact springs located in the northwestern part of the Reservation. Data were collected to evaluate potential alternative sources of water supply for the village of Red Shirt, which currently obtains water of marginal quality from a well completed in the Inyan Kara aquifer. During 1995-97, water-quality data also were collected for 44 public-supply wells that serve about one-half of the Reservation's population. Quality-assurance sampling was used to evaluate the precision and accuracy of environmental samples. Ten of the springs sampled contact the White River Group, and four contact the Pierre Shale. Springs contacting the White River Group range from calcium bicarbonate to sodium bicarbonate water types. Two springs contacting the Pierre Shale have water types similar to this; however, sulfate is the dominant anion for the other two springs. In general, springs contacting the White River Group are shown to have better potential as alternative sources of water supply for the village of Red Shirt than springs contacting the Pierre Shale. Nine of the springs with better water quality were sampled repeatedly; however, only minor variability in water quality was identified. Six of these nine springs, of which five contact the White River Group, probably have the best potential for use as water supplies. Discharge from any of these six springs probably would provide adequate water supply for Red Shirt during most periods, based on a limited number of discharge measurements collected. Concentrations of lead exceeded the U.S. Environmental Protection Agency (USEPA) action level of 15 ?g/L for three of these six springs. Five of these six springs also had arsenic concentrations that exceeded 10 ?g/L, which could be problematic if the current maximum contaminant level (MCL) is lowered. Blending of water from one or more springs with water from the existing Inyan Kara well may be an option to address concerns regarding both quantity and quality of existing and potential sources. All nine springs that were sampled for indicator bacteria had positive detections on one or more occasions during presumptive tests. Although USEPA standards for bacteria apply only to public-water supplies, local residents using spring water for domestic purposes need to be aware of the potential health risks associated with consuming untreated water. One spring contacting the White River Group and two springs contacting the Pierre Shale exceeded 15 pCi/L for gross alpha; these values do not necessarily constitute exceedances of the MCL, which excludes radioactivity contributed by uranium and radon. Additional sampling using different analysis techniques would be needed to conclusively determine if any samples exceeded this MCL. Nine springs were sampled for selected pesticides and tritium. The pesticides atrazine, carbaryl, and 2,4-D were not detected in any of the samples. The nine springs were analyzed for tritium in order to generally assess the age of the water and to determine if concentrations exceeded the MCL established for gross beta-particle activity. Tritium results indicated two springs are composed primarily of water recharged prior to atmospheric testing of nuclear bombs and two other springs have a relatively large percentage of test-era water. The remaining five springs had tritium values that indicated some percentage of test-era water; however, additional sampling would be needed to determine whether water is predominantly pre- or post-bomb age. Of the 44 public-supply wells sampled, 42 are completed in the Arikaree aquifer, one is completed in an alluvial aquifer, and one is completed in the Inyan Kara aquifer. Water

Employees with Myasthenia Gravis

MedlinePlus

... of Disabilities Publications Resources Home | Accommodation and Compliance Series: Employees with Myasthenia Gravis By Linda Carter Batiste, ... rest breaks Fine Motor Impairment: Implement ergonomic workstation design Provide alternative computer and telephone access Provide arm ...

Addressing Students' Alternative Conceptions on the Propagation of Periodic Waves Using a Refutational Text

ERIC Educational Resources Information Center

Caleon, Imelda; Subramaniam, R.

2013-01-01

The effectiveness of a refutational text in addressing the alternative conceptions held by secondary school students on the topic of wave propagation in an elastic medium was explored in this study. The refutational text, which was 816 words long and featured the particle-spring model, was found to be more effective in promoting conceptual change…

Using Two-Tier Test to Identify Primary Students' Conceptual Understanding and Alternative Conceptions in Acid Base

ERIC Educational Resources Information Center

Bayrak, Beyza Karadeniz

2013-01-01

The purpose of this study was to identify primary students' conceptual understanding and alternative conceptions in acid-base. For this reason, a 15 items two-tier multiple choice test administered 56 eighth grade students in spring semester 2009-2010. Data for this study were collected using a conceptual understanding scale prepared to include…

Climate-induced warming imposes a threat to north European spring ecosystems.

PubMed

Jyväsjärvi, Jussi; Marttila, Hannu; Rossi, Pekka M; Ala-Aho, Pertti; Olofsson, Bo; Nisell, Jakob; Backman, Birgitta; Ilmonen, Jari; Virtanen, Risto; Paasivirta, Lauri; Britschgi, Ritva; Kløve, Bjørn; Muotka, Timo

2015-12-01

Interest in climate change effects on groundwater has increased dramatically during the last decade. The mechanisms of climate-related groundwater depletion have been thoroughly reviewed, but the influence of global warming on groundwater-dependent ecosystems (GDEs) remains poorly known. Here we report long-term water temperature trends in 66 northern European cold-water springs. A vast majority of the springs (82%) exhibited a significant increase in water temperature during 1968-2012. Mean spring water temperatures were closely related to regional air temperature and global radiative forcing of the corresponding year. Based on three alternative climate scenarios representing low (RCP2.6), intermediate (RCP6) and high-emission scenarios (RCP8.5), we estimate that increase in mean spring water temperature in the region is likely to range from 0.67 °C (RCP2.6) to 5.94 °C (RCP8.5) by 2086. According to the worst-case scenario, water temperature of these originally cold-water ecosystems (regional mean in the late 1970s: 4.7 °C) may exceed 12 °C by the end of this century. We used bryophyte and macroinvertebrate species data from Finnish springs and spring-fed streams to assess ecological impacts of the predicted warming. An increase in spring water temperature by several degrees will likely have substantial biodiversity impacts, causing regional extinction of native, cold-stenothermal spring specialists, whereas species diversity of headwater generalists is likely to increase. Even a slight (by 1 °C) increase in water temperature may eliminate endemic spring species, thus altering bryophyte and macroinvertebrate assemblages of spring-fed streams. Climate change-induced warming of northern regions may thus alter species composition of the spring biota and cause regional homogenization of biodiversity in headwater ecosystems. © 2015 John Wiley & Sons Ltd.

Indicator saturation: a novel approach to detect multiple breaks in geodetic time series.

NASA Astrophysics Data System (ADS)

Jackson, L. P.; Pretis, F.; Williams, S. D. P.

2016-12-01

Geodetic time series can record long term trends, quasi-periodic signals at a variety of time scales from days to decades, and sudden breaks due to natural or anthropogenic causes. The causes of breaks range from instrument replacement to earthquakes to unknown (i.e. no attributable cause). Furthermore, breaks can be permanent or short-lived and range at least two orders of magnitude in size (mm to 100's mm). To account for this range of possible signal-characteristics requires a flexible time series method that can distinguish between true and false breaks, outliers and time-varying trends. One such method, Indicator Saturation (IS) comes from the field of econometrics where analysing stochastic signals in these terms is a common problem. The IS approach differs from alternative break detection methods by considering every point in the time series as a break until it is demonstrated statistically that it is not. A linear model is constructed with a break function at every point in time, and all but statistically significant breaks are removed through a general-to-specific model selection algorithm for more variables than observations. The IS method is flexible because it allows multiple breaks of different forms (e.g. impulses, shifts in the mean, and changing trends) to be detected, while simultaneously modelling any underlying variation driven by additional covariates. We apply the IS method to identify breaks in a suite of synthetic GPS time series used for the Detection of Offsets in GPS Experiments (DOGEX). We optimise the method to maximise the ratio of true-positive to false-positive detections, which improves estimates of errors in the long term rates of land motion currently required by the GPS community.

[Effects of alternative furrow irrigation and nitrogen application rate on photosynthesis, growth, and yield of cucumber in solar greenhouse].

PubMed

Zhang, Liu-xia; Wang, Shu-zhong; Sui, Xiao-lei; Zhang, Zhen-xian

2011-09-01

This paper studied the effects of alternative furrow irrigation and nitrogen (N) application rate (no N, optimal N, and conventional N) on the photosynthesis, growth characteristics, yield formation, and fruit quality of cucumber (Cucumis sativus) cultivar Jinyu No. 5 in a solar greenhouse in winter-spring growth season and autumn-winter season. Under alternative furrow irrigation, the net photosynthetic rate of upper, middle, eand lower leaves was appreciably lower and the transpiration rate decreased significantly, and the transient water use efficiency of upper and middle leaves improved, as compared with those under conventional irrigation. Stomatal factor was the limiting factor of photosynthesis under alternative furrow irrigation. The photosynthesis and transient water use efficiency of functional leaves under alternative furrow irrigation increased with increasing N application rate. Comparing with conventional irrigation, alternative furrow irrigation decreased leaf chlorophyll content and plant biomass, but increased root biomass, root/shoot ratio, and dry matter allocation in root and fruit. The economic output under alternative furrow irrigation was nearly the same as that under conventional irrigation, whereas the water use efficiency for economic yield increased significantly, suggesting the beneficial effects of alternative furrow irrigation on root development and fruit formation. With the increase of N application rate, the leaf chlorophyll content, chlorophyll a/b, specific leaf mass, plant biomass, economic yield, and fruit Vc and soluble sugar contents under alternative furrow irrigation increased, but no significant difference was observed between the treatments optimal N and conventional N. N application had little effects on the water use efficiency for economic yield. The economic yield and biomass production of the cucumber were significantly higher in winter-spring growth season than in autumn-winter growth season.

Preliminary Feasibility Report Stage II, Lorain Small-Boat Harbor, Lorain, Ohio. Revision.

DTIC Science & Technology

1982-03-01

effects of each alternative plan. Activities consist of analyzing each measure to deter- mine potential sources , the incidence, and the magni- tude...using existing reports, available data sources , visual inspections, onsite interviews, and workshop discussions. Alternative small-boat harbor designs...were developed to a consistent level of detail. Prior reports were used as data sources for preliminary design of break- waters, including length

A comparative cost analysis of robotic-assisted surgery versus laparoscopic surgery and open surgery: the necessity of investing knowledgeably.

PubMed

Tedesco, Giorgia; Faggiano, Francesco C; Leo, Erica; Derrico, Pietro; Ritrovato, Matteo

2016-11-01

Robotic surgery has been proposed as a minimally invasive surgical technique with advantages for both surgeons and patients, but is associated with high costs (installation, use and maintenance). The Health Technology Assessment Unit of the Bambino Gesù Children's Hospital sought to investigate the economic sustainability of robotic surgery, having foreseen its impact on the hospital budget METHODS: Break-even and cost-minimization analyses were performed. A deterministic approach for sensitivity analysis was applied by varying the values of parameters between pre-defined ranges in different scenarios to see how the outcomes might differ. The break-even analysis indicated that at least 349 annual interventions would need to be carried out to reach the break-even point. The cost-minimization analysis showed that robotic surgery was the most expensive procedure among the considered alternatives (in terms of the contribution margin). Robotic surgery is a good clinical alternative to laparoscopic and open surgery (for many pediatric operations). However, the costs of robotic procedures are higher than the equivalent laparoscopic and open surgical interventions. Therefore, in the short run, these findings do not seem to support the decision to introduce a robotic system in our hospital.

Telomere-Internal Double-Strand Breaks Are Repaired by Homologous Recombination and PARP1/Lig3-Dependent End-Joining.

PubMed

Doksani, Ylli; de Lange, Titia

2016-11-01

Shelterin protects chromosome ends from the DNA damage response. Although the mechanism of telomere protection has been studied extensively, the fate of double-strand breaks (DSBs) inside telomeres is not known. Here, we report that telomere-internal FokI-induced DSBs activate ATM kinase-dependent signaling in S-phase but are well tolerated and repaired efficiently. Homologous recombination contributes to repair, leading to increased telomere length heterogeneity typical of the alternative lengthening of telomeres (ALT) pathway. Furthermore, cells accumulate extra chromosomal telomeric signals (ECTS), a second hallmark of ALT. Telomere-internal DSBs are also repaired by a PARP1- and Ligase3-dependent reaction, suggesting alternative non-homologous end-joining (alt-NHEJ), which relies on microhomology at DSBs. However, as resected telomere-internal DSBs have perfect homology, their PARP1/Lig3-dependent end-joining may be more akin to single strand break repair. We conclude that shelterin does not repress ATM kinase signaling or DSB repair at telomere-internal sites, thereby allowing DNA repair to maintain telomere integrity. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

The role of Pif1p, a DNA helicase in Saccharomyces cerevisiae, in maintaining mitochondrial DNA.

PubMed

Cheng, Xin; Dunaway, Stephen; Ivessa, Andreas S

2007-05-01

Mitochondrial DNA (mtDNA) is highly susceptible to oxidative and chemically induced damage, and these insults lead to a number of diseases. In Saccharomyces cerevisiae, the DNA helicase Pif1p is localized to the nucleus and mitochondria. We show that pif1 mutant cells are sensitive to ethidium bromide-induced damage and this mtDNA is prone to fragmentation. We also show that Pif1p associates with mtDNA. In pif1 mutant cells, mtDNA breaks at specific sites that exhibit Pif1-dependent recombination. We conclude that Pif1p participates in the protection from double-stranded (ds) DNA breaks or alternatively in the repair process of dsDNA breaks in mtDNA.

75 FR 30364 - Mt. Hood and Willamette National Forests, Oregon; Cascade Crossing Transmission Project

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-01

... Bonneville Power Administration (BPA) transmission lines through National Forest lands. The second alternative would follow the existing BPA transmission lines through the Confederated Tribes of Warm Springs...

Integrated Status and Effectiveness Monitoring Program; Expansion of Existing Smolt Trapping Program in Nason Creek, 2005 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prevatte, Scott A.

2006-03-01

In the fall of 2004, as one part of a Basin-Wide Monitoring Program developed by the Upper Columbia Regional Technical Team and Upper Columbia Salmon Recovery Board, the Yakama Nation Fisheries Resource Management program began monitoring downstream migration of ESA listed Upper Columbia River spring chinook salmon and Upper Columbia River steelhead in Nason Creek, a tributary to the Wenatchee River. This report summarizes juvenile spring chinook salmon and steelhead trout migration data collected in Nason Creek during 2005 and also incorporates data from 2004. We used species enumeration at the trap and efficiency trials to describe emigration timing andmore » to estimate population size. Data collection was divided into spring/early summer and fall periods with a break during the summer months occurring due to low stream flow. Trapping began on March 1st and was suspended on July 29th when stream flow dropped below the minimum (30 cfs) required to rotate the trap cone. The fall period began on September 28th with increased stream flow and ended on November 23rd when snow and ice began to accumulate on the trap. During the spring and early summer we collected 311 yearling (2003 brood) spring chinook salmon, 86 wild steelhead smolts and 453 steelhead parr. Spring chinook (2004 brood) outgrew the fry stage of fork length < 60 mm during June and July, 224 were collected at the trap. Mark-recapture trap efficiency trials were performed over a range of stream discharge stages whenever ample numbers of fish were being collected. A total of 247 spring chinook yearlings, 54 steelhead smolts, and 178 steelhead parr were used during efficiency trials. A statically significant relationship between stream discharge and trap efficiency has not been identified in Nason Creek, therefore a pooled trap efficiency was used to estimate the population size of both spring chinook (14.98%) and steelhead smolts (12.96%). We estimate that 2,076 ({+-} 119 95%CI) yearling spring chinook and 688 ({+-} 140 95%CI) steelhead smolts emigrated past the trap during the spring/early summer sample period along with 10,721 ({+-} 1,220 95%CI) steelhead parr. During the fall we collected 924 subyearling (2004 brood) spring chinook salmon and 1,008 steelhead parr of various size and age classes. A total of 732 spring chinook subyearlings and 602 steelhead parr were used during 13 mark-recapture trap efficiency trials. A pooled trap efficiency of 24.59% was used to calculate the emigration of spring chinook and 17.11% was used for steelhead parr during the period from September 28th through November 23rd. We estimate that 3758 ({+-} 92 95%CI) subyearling spring chinook and 5,666 ({+-} 414 95%CI) steelhead parr migrated downstream past the trap along with 516 ({+-} 42 95%CI) larger steelhead pre-smolts during the 2005 fall sample period.« less

Randomized Controlled Trial of a Spring Break Intervention to Reduce High-Risk Drinking

PubMed Central

Lee, Christine M.; Neighbors, Clayton; Lewis, Melissa A.; Kaysen, Debra; Mittmann, Angela; Geisner, Irene M.; Atkins, David C.; Zheng, Cheng; Garberson, Lisa A.; Kilmer, Jason R.; Larimer, Mary E.

2014-01-01

Objective While recent studies have documented high-risk drinking occurring during Spring Break (SB), particularly on SB trips with friends, published intervention studies are few. The present study evaluated the efficacy of Event Specific Prevention (ESP) strategies for reducing SB drinking among college students, compared to general prevention strategies and an assessment-only control group, as well as evaluated inclusion of peers in interventions and mode of intervention delivery (in-person vs. web). Method Participants included 783 undergraduates (56.1% women, average age 20.5) intending to go on a SB trip with friends as well as to drink heavily on at least one day of SB. Participants completed assessments prior to SB and were randomized to one of five intervention conditions: SB in-person BASICS, SB web BASICS, SB in-person BASICS with friend, SB web BASICS with friend, general BASICS, or an attention control condition. Follow-up assessment was completed one week after SB. Results While the SB web BASICS (with and without friends) and general BASICS interventions were not effective at reducing SB drinking, results indicated significant intervention effects for SB in-person BASICS in reducing SB drinking, particularly on trip days. Follow-up analyses indicated change in descriptive norms mediated treatment effect and reductions in drinking, while SB drinking intentions and positive expectancies did not. Conclusions Overall, results suggest an in-person SB-specific intervention is effective at reducing SB drinking, especially during trips. In contrast, interventions that contain non-SB related content, are web-based, or seek to involve friends may be less effective at reducing SB drinking. PMID:24491072

Predicting climate change impacts on polar bear litter size.

PubMed

Molnár, Péter K; Derocher, Andrew E; Klanjscek, Tin; Lewis, Mark A

2011-02-08

Predicting the ecological impacts of climate warming is critical for species conservation. Incorporating future warming into population models, however, is challenging because reproduction and survival cannot be measured for yet unobserved environmental conditions. In this study, we use mechanistic energy budget models and data obtainable under current conditions to predict polar bear litter size under future conditions. In western Hudson Bay, we predict climate warming-induced litter size declines that jeopardize population viability: ∼28% of pregnant females failed to reproduce for energetic reasons during the early 1990s, but 40-73% could fail if spring sea ice break-up occurs 1 month earlier than during the 1990s, and 55-100% if break-up occurs 2 months earlier. Simultaneously, mean litter size would decrease by 22-67% and 44-100%, respectively. The expected timeline for these declines varies with climate-model-specific sea ice predictions. Similar litter size declines may occur in over one-third of the global polar bear population.

Predicting climate change impacts on polar bear litter size

PubMed Central

Molnár, Péter K.; Derocher, Andrew E.; Klanjscek, Tin; Lewis, Mark A.

2011-01-01

Predicting the ecological impacts of climate warming is critical for species conservation. Incorporating future warming into population models, however, is challenging because reproduction and survival cannot be measured for yet unobserved environmental conditions. In this study, we use mechanistic energy budget models and data obtainable under current conditions to predict polar bear litter size under future conditions. In western Hudson Bay, we predict climate warming-induced litter size declines that jeopardize population viability: ∼28% of pregnant females failed to reproduce for energetic reasons during the early 1990s, but 40–73% could fail if spring sea ice break-up occurs 1 month earlier than during the 1990s, and 55–100% if break-up occurs 2 months earlier. Simultaneously, mean litter size would decrease by 22–67% and 44–100%, respectively. The expected timeline for these declines varies with climate-model-specific sea ice predictions. Similar litter size declines may occur in over one-third of the global polar bear population. PMID:21304515

Alternative Fuels Data Center: How Do Diesel Vehicles Work?

Science.gov Websites

reduces particulate matter and breaks down dangerous NOx emissions into harmless nitrogen and water (DEF) is injected into the exhaust gas mixture and is reduced to nitrogen and water by chemical

Steady states and linear stability analysis of precipitation pattern formation at geothermal hot springs.

PubMed

Chan, Pak Yuen; Goldenfeld, Nigel

2007-10-01

A dynamical theory of geophysical precipitation pattern formation is presented and applied to irreversible calcium carbonate (travertine) deposition. Specific systems studied here are the terraces and domes observed at geothermal hot springs, such as those at Yellowstone National Park, and speleothems, particularly stalactites and stalagmites. The theory couples the precipitation front dynamics with shallow water flow, including corrections for turbulent drag and curvature effects. In the absence of capillarity and with a laminar flow profile, the theory predicts a one-parameter family of steady state solutions to the moving boundary problem describing the precipitation front. These shapes match the measured shapes near the vent at the top of observed travertine domes well. Closer to the base of the dome, the solutions deviate from observations and circular symmetry is broken by a fluting pattern, which we show is associated with capillary forces causing thin film break-up. We relate our model to that recently proposed for stalactite growth, and calculate the linear stability spectrum of both travertine domes and stalactites. Lastly, we apply the theory to the problem of precipitation pattern formation arising from turbulent flow down an inclined plane and identify a linear instability that underlies scale-invariant travertine terrace formation at geothermal hot springs.

Steady states and linear stability analysis of precipitation pattern formation at geothermal hot springs

NASA Astrophysics Data System (ADS)

Chan, Pak Yuen; Goldenfeld, Nigel

2007-10-01

A dynamical theory of geophysical precipitation pattern formation is presented and applied to irreversible calcium carbonate (travertine) deposition. Specific systems studied here are the terraces and domes observed at geothermal hot springs, such as those at Yellowstone National Park, and speleothems, particularly stalactites and stalagmites. The theory couples the precipitation front dynamics with shallow water flow, including corrections for turbulent drag and curvature effects. In the absence of capillarity and with a laminar flow profile, the theory predicts a one-parameter family of steady state solutions to the moving boundary problem describing the precipitation front. These shapes match the measured shapes near the vent at the top of observed travertine domes well. Closer to the base of the dome, the solutions deviate from observations and circular symmetry is broken by a fluting pattern, which we show is associated with capillary forces causing thin film break-up. We relate our model to that recently proposed for stalactite growth, and calculate the linear stability spectrum of both travertine domes and stalactites. Lastly, we apply the theory to the problem of precipitation pattern formation arising from turbulent flow down an inclined plane and identify a linear instability that underlies scale-invariant travertine terrace formation at geothermal hot springs.

Spline-Screw Multiple-Rotation Mechanism

NASA Technical Reports Server (NTRS)

Vranish, John M.

1994-01-01

Mechanism functions like combined robotic gripper and nut runner. Spline-screw multiple-rotation mechanism related to spline-screw payload-fastening system described in (GSC-13454). Incorporated as subsystem in alternative version of system. Mechanism functions like combination of robotic gripper and nut runner; provides both secure grip and rotary actuation of other parts of system. Used in system in which no need to make or break electrical connections to payload during robotic installation or removal of payload. More complicated version needed to make and break electrical connections. Mechanism mounted in payload.

The autumn effect: timing of physical dormancy break in seeds of two winter annual species of Geraniaceae by a stepwise process

PubMed Central

Gama-Arachchige, N. S.; Baskin, J. M.; Geneve, R. L.; Baskin, C. C.

2012-01-01

Background and Aims The involvement of two steps in the physical dormancy (PY)-breaking process previously has been demonstrated in seeds of Fabaceae and Convolvulaceae. Even though there is a claim for a moisture-controlled stepwise PY-breaking in some species of Geraniaceae, no study has evaluated the role of temperature in the PY-breaking process in this family. The aim of this study was to determine whether a temperature-controlled stepwise PY-breaking process occurs in seeds of the winter annuals Geranium carolinianum and G. dissectum. Methods Seeds of G. carolinianum and G. dissectum were stored under different temperature regimes to test the effect of storage temperature on PY-break. The role of temperature and moisture regimes in regulating PY-break was investigated by treatments simulating natural conditions. Greenhouse (non-heated) experiments on seed germination and burial experiments (outdoors) were carried out to determine the PY-breaking behaviour in the natural habitat. Key Results Irrespective of moisture conditions, sensitivity to the PY-breaking step in seeds of G. carolinianum was induced at temperatures ≥20 °C, and exposure to temperatures ≤20 °C made the sensitive seeds permeable. Sensitivity of seeds increased with time. In G. dissectum, PY-break occurred at temperatures ≥20 °C in a single step under constant wet or dry conditions and in two steps under alternate wet–dry conditions if seeds were initially kept wet. Conclusions Timing of seed germination with the onset of autumn can be explained by PY-breaking processes involving (a) two temperature-dependent steps in G. carolinianum and (b) one or two moisture-dependent step(s) along with the inability to germinate under high temperatures in G. dissectum. Geraniaceae is the third of 18 families with PY in which a two-step PY-breaking process has been demonstrated. PMID:22684684

Rotational diffusion of a molecular cat

NASA Astrophysics Data System (ADS)

Katz-Saporta, Ori; Efrati, Efi

We show that a simple isolated system can perform rotational random walk on account of internal excitations alone. We consider the classical dynamics of a ''molecular cat'': a triatomic molecule connected by three harmonic springs with non-zero rest lengths, suspended in free space. In this system, much like for falling cats, the angular momentum constraint is non-holonomic allowing for rotations with zero overall angular momentum. The geometric nonlinearities arising from the non-zero rest lengths of the springs suffice to break integrability and lead to chaotic dynamics. The coupling of the non-integrability of the system and its non-holonomic nature results in an angular random walk of the molecule. We study the properties and dynamics of this angular motion analytically and numerically. For low energy excitations the system displays normal-mode-like motion, while for high enough excitation energy we observe regular random-walk. In between, at intermediate energies we observe an angular Lévy-walk type motion associated with a fractional diffusion coefficient interpolating between the two regimes.

Zeaxanthin-independent energy quenching and alternative electron sinks cause a decoupling of the relationship between the photochemical reflectance index (PRI) and photosynthesis in an evergreen conifer during spring

PubMed Central

Fréchette, Emmanuelle; Wong, Christopher Y. S.; Junker, Laura Verena; Chang, Christine Yao-Yun; Ensminger, Ingo

2015-01-01

In evergreen conifers, the winter down-regulation of photosynthesis and its recovery during spring are the result of a reorganization of the chloroplast and adjustments of energy-quenching mechanisms. These phenological changes may remain undetected by remote sensing, as conifers retain green foliage during periods of photosynthetic down-regulation. The aim was to assess if the timing of the spring recovery of photosynthesis and energy-quenching characteristics are accurately monitored by the photochemical reflectance index (PRI) in the evergreen conifer Pinus strobus. The recovery of photosynthesis was studied using chlorophyll fluorescence, leaf gas exchange, leaf spectral reflectance, and photosynthetic pigment measurements. To assess if climate change might affect the recovery of photosynthesis, seedlings were exposed to cold spring conditions or warm spring conditions with elevated temperature. An early spring decoupling of the relationship between photosynthesis and PRI in both treatments was observed. This was caused by differences between the timing of the recovery of photosynthesis and the timing of carotenoid and chlorophyll pool size adjustments which are the main factors controlling PRI during spring. It was also demonstrated that zeaxanthin-independent NPQ mechanisms undetected by PRI further contributed to the early spring decoupling of the PRI–LUE relationship. An important mechanism undetected by PRI seems to involve increased electron transport around photosystem I, which was a significant energy sink during the entire spring transition, particularly in needles exposed to a combination of high light and cold temperatures. PMID:26386258

Special Advanced Studies for Pollution Prevention. Delivery Order 0058: The Monitor - Spring 2000

DTIC Science & Technology

2001-04-01

Process complexity ➨ Strippability ➨ Maturity ➨ Process type and chemistry ➨ Licensing requirements ➨ Vendor information ➨ Niplate 700 (Surface...Courses of Action 4 Identify & Evaluate Potential Alternatives 5 Select Best Alternative & Develop Project 6 Prioritize Projects by Commodity 7 Rank...Burden CS Priority Process Specific P2 OASolution Selection Solution Planning Solution Implementation Solution Evaluation Phase 2 Phase 3 Phase 1

Effects of alternatives to clearcutting on invertebrate and organic detritus transport from headwaters in southeastern Alaska.

Treesearch

Jake Musslewhite; Mark S. Wipfli

2004-01-01

We examined the transport of invertebrates and coarse organic detritus from headwater streams draining timber harvest units in a selective timber harvesting study, alternatives to clearcutting (ATC) in southeastern Alaska. Transport in 17 small streams (mean measured discharge range: 1.2 to 14.6 L/s) was sampled with 250- µ m-mesh drift nets in spring, summer, and fall...

DNA Double-Strand Break Repair as Determinant of Cellular Radiosensitivity to Killing and Target in Radiation Therapy

PubMed Central

Mladenov, Emil; Magin, Simon; Soni, Aashish; Iliakis, George

2013-01-01

Radiation therapy plays an important role in the management of a wide range of cancers. Besides innovations in the physical application of radiation dose, radiation therapy is likely to benefit from novel approaches exploiting differences in radiation response between normal and tumor cells. While ionizing radiation induces a variety of DNA lesions, including base damages and single-strand breaks, the DNA double-strand break (DSB) is widely considered as the lesion responsible not only for the aimed cell killing of tumor cells, but also for the general genomic instability that leads to the development of secondary cancers among normal cells. Homologous recombination repair (HRR), non-homologous end-joining (NHEJ), and alternative NHEJ, operating as a backup, are the major pathways utilized by cells for the processing of DSBs. Therefore, their function represents a major mechanism of radiation resistance in tumor cells. HRR is also required to overcome replication stress – a potent contributor to genomic instability that fuels cancer development. HRR and alternative NHEJ show strong cell-cycle dependency and are likely to benefit from radiation therapy mediated redistribution of tumor cells throughout the cell-cycle. Moreover, the synthetic lethality phenotype documented between HRR deficiency and PARP inhibition has opened new avenues for targeted therapies. These observations make HRR a particularly intriguing target for treatments aiming to improve the efficacy of radiation therapy. Here, we briefly describe the major pathways of DSB repair and review their possible contribution to cancer cell radioresistance. Finally, we discuss promising alternatives for targeting DSB repair to improve radiation therapy and cancer treatment. PMID:23675572

Framework for the Texas Highway Cost Allocation Study

DOT National Transportation Integrated Search

2001-01-01

In fiscal year 1998, Texas spent $2.8 billion on the state-maintained road network, which includes the Interstate highways. This project estimates the contribution to these costs of different vehicle classes. Alternative methods of breaking down ('al...

Production of Bacterial Cellulose by Gluconacetobacter hansenii Using Corn Steep Liquor As Nutrient Sources

PubMed Central

Costa, Andrea F. S.; Almeida, Fabíola C. G.; Vinhas, Glória M.; Sarubbo, Leonie A.

2017-01-01

Cellulose is mainly produced by plants, although many bacteria, especially those belonging to the genus Gluconacetobacter, produce a very peculiar form of cellulose with mechanical and structural properties that can be exploited in numerous applications. However, the production cost of bacterial cellulose (BC) is very high to the use of expensive culture media, poor yields, downstream processing, and operating costs. Thus, the purpose of this work was to evaluate the use of industrial residues as nutrients for the production of BC by Gluconacetobacter hansenii UCP1619. BC pellicles were synthesized using the Hestrin–Schramm (HS) medium and alternative media formulated with different carbon (sugarcane molasses and acetylated glucose) and nitrogen sources [yeast extract, peptone, and corn steep liquor (CSL)]. A jeans laundry was also tested. None of the tested sources (beside CSL) worked as carbon and nutrient substitute. The alternative medium formulated with 1.5% glucose and 2.5% CSL led to the highest yield in terms of dry and hydrated mass. The BC mass produced in the alternative culture medium corresponded to 73% of that achieved with the HS culture medium. The BC pellicles demonstrated a high concentration of microfibrils and nanofibrils forming a homogenous, compact, and three-dimensional structure. The biopolymer produced in the alternative medium had greater thermal stability, as degradation began at 240°C, while degradation of the biopolymer produced in the HS medium began at 195°C. Both biopolymers exhibited high crystallinity. The mechanical tensile test revealed the maximum breaking strength and the elongation of the break of hydrated and dry pellicles. The dry BC film supported up to 48 MPa of the breaking strength and exhibited greater than 96.98% stiffness in comparison with the hydrated film. The dry film supported up to 48 MPa of the breaking strength and exhibited greater than 96.98% stiffness in comparison with the hydrated film. The values obtained for the Young’s modulus in the mechanical tests in the hydrated samples indicated low values for the variable rigidity. The presence of water in the interior and between the nanofibers of the hydrated BC only favored the results for the elasticity, which was 56.37% higher when compared to the dry biomaterial. PMID:29089941

A long term glider study of shelf sea oxygen dynamics

NASA Astrophysics Data System (ADS)

Williams, Charlotte; Palmer, Matthew; Mahaffey, Claire; Davis, Clare

2017-04-01

Oxygen is involved in most biogeochemical processes in the ocean, and dissolved oxygen (DO) is a well-established indicator for biological activity via the estimate of apparent oxygen utilisation (AOU). In the deep waters of the open ocean, the AOU provides a valuable insight into the ocean's biological carbon pump. However, in the physically dynamic and highly productive shallow shelf seas, interpretation of the oxygen distribution and the magnitude of AOU is complex. Physical processes, such as diapycnal mixing, entrainment and horizontal advection act to ventilate waters below the thermocline and thus increase oxygen and decrease AOU. In contrast, biological remineralisation of organic material below the thermocline will consume oxygen and increase AOU. We aim to address the following: 1. Does AOU change seasonally in a shelf sea in response to seasonal changes in productivity? 2. How important is turbulence in redistributing oxygen in a shelf sea? Using 9 months of high-resolution data from >20 glider deployments in the seasonally stratified NW European Shelf Sea we identify and quantify the physical and biological processes that control the DO distribution and magnitude of AOU in shelf seas. A 200km transect between the shelf edge and the central Celtic Sea (CCS) was repeated between November 2014 and August 2015, thus capturing key periods in the seasonal cycling in shelf seas, specifically the onset of stratification, the spring bloom, stratified summer period and breakdown of stratification. The gliders collected data for DO, temperature, salinity, chlorophyll fluorescence, CDOM, backscatter and turbulence. In addition, direct measurements of turbulent dissipation from the Ocean Microstructure Glider deployed during the campaign provided estimates of mixing at CCS and the shelf break, allowing accurate quantification of the vertical fluxes of oxygen. We find that oxygen decreases ubiquitously across the shelf as soon as stratification takes hold, though BML oxygen decreases at a slower rate during summer compared to spring at the shelf break and also across the inner shelf. This appears to be due to a stronger oxycline and potentially more efficient, sporadic mixing of oxygen across the thermocline during summer. Biological oxygen consumption is greater at the shelf break than on shelf even when accounting for enhanced oxygen diapycnal fluxes at the shelf break. Gliders prove to be a good tool in monitoring long term oxygen changes in shelf seas and we find that accurate estimation of AOU in the shelf sea requires inclusion of mixing processes.

Rossby wave breaking and Lagrangian structures inside the Antarctic stratospheric polar vortex during Vorcore and Concordiasi campaigns

NASA Astrophysics Data System (ADS)

de la Camara, Alvaro; Mechoso, Carlos R.; Mancho, Ana M.; Serrano, Encarna; Ide, Kayo

2013-04-01

The trajectories in the lower stratosphere of isopycnic balloons released from Antarctica by international field campaigns during the southern springs of 2005 and 2010 showed events of latitudinal transport inside the stratospheric polar vortex, both away and towards the poleward flank of the polar night jet. The present work applies trajectory-based diagnostic techniques to examine mechanisms at work during such events. Reverse domain filling calculations of potential vorticity (PV) fields from ECMWF ERA-Interim data set during the events show irreversible filamentation of the PV fields in the inner side of the polar night jet, which is a signature of planetary (Rossby) wave breaking. Balloons motions during the events are fairly consistent with the PV filaments. Events of both large (~15° of arch length) and small (~5° of arch length) balloon displacements from the vortex edge are associated to deep and shallow penetration into the core of the elongated PV contours. The function M is applied to study the configuration of Lagrangian coherent structures during the events. A close association is found between hyperbolic points and breaking waves inside the vortex. The geometric configuration of the invariant manifolds associated with the hyperbolic points helps to understand the apparent chaotic behavior of balloons motions, and to identify and analyze balloon transport events not captured by the Reverse Domain Filling calculations. The Antarctic polar vortex edge is an effective barrier to air parcel crossings. Rossby wave breaking inside the vortex, however, can contribute to tracer mixing inside the vortex and to occasional air crossings of the edge.

Liquid-hydrogen/nuclear-radiation resistant seals

NASA Technical Reports Server (NTRS)

Van Auken, R.

1971-01-01

Seal employs aromatic heterocyclic polymer, polyquinoxaline, and features resin starved laminate consisting of alternate layers of woven glass fabric and polymer film. Design gives gasket a mechanical spring characteristic, eliminating cold flow and resulting in elastic recovery when gasket is unloaded.

Orthogonality-breaking sensing model based on the instantaneous Stokes vector and the Mueller calculus

NASA Astrophysics Data System (ADS)

Ortega-Quijano, Noé; Fade, Julien; Roche, Muriel; Parnet, François; Alouini, Mehdi

2016-04-01

Polarimetric sensing by orthogonality breaking has been recently proposed as an alternative technique for performing direct and fast polarimetric measurements using a specific dual-frequency dual-polarization (DFDP) source. Based on the instantaneous Stokes-Mueller formalism to describe the high-frequency evolution of the DFDP beam intensity, we thoroughly analyze the interaction of such a beam with birefringent, dichroic and depolarizing samples. This allows us to confirm that orthogonality breaking is produced by the sample diattenuation, whereas this technique is immune to both birefringence and diagonal depolarization. We further analyze the robustness of this technique when polarimetric sensing is performed through a birefringent waveguide, and the optimal DFDP source configuration for fiber-based endoscopic measurements is subsequently identified. Finally, we consider a stochastic depolarization model based on an ensemble of random linear diattenuators, which makes it possible to understand the progressive vanishing of the detected orthogonality breaking signal as the spatial heterogeneity of the sample increases, thus confirming the insensitivity of this method to diagonal depolarization. The fact that the orthogonality breaking signal is exclusively due to the sample dichroism is an advantageous feature for the precise decoupled characterization of such an anisotropic parameter in samples showing several simultaneous effects.

An Examination of Test-Retest, Alternate Form Reliability, and Generalizability Theory Study of the easyCBM Reading Assessments: Grade 1. Technical Report #1216

ERIC Educational Resources Information Center

Anderson, Daniel; Park, Jasmine, Bitnara; Lai, Cheng-Fei; Alonzo, Julie; Tindal, Gerald

2012-01-01

This technical report is one in a series of five describing the reliability (test/retest/and alternate form) and G-Theory/D-Study research on the easy CBM reading measures, grades 1-5. Data were gathered in the spring 2011 from a convenience sample of students nested within classrooms at a medium-sized school district in the Pacific Northwest. Due…

49 CFR 236.2 - Grounds.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., single-break, signal control circuits using a grounded common, and alternating current power distribution... TRANSPORTATION RULES, STANDARDS, AND INSTRUCTIONS GOVERNING THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR... General § 236.2 Grounds. Each circuit, the functioning of which affects the safety of train operations...

The opportunities and realities of doing science in an alternative research environment

NASA Astrophysics Data System (ADS)

Newman, Claire E.

2018-01-01

A planetary scientist describes how she left the traditional corridors of academia to help found her own company, thereby continuing her research program and interests. The flexibility afforded by this break-away has been life-changing.

Small-scale Geothermal Power Plants Using Hot Spring Water

NASA Astrophysics Data System (ADS)

Tosha, T.; Osato, K.; Kiuchi, T.; Miida, H.; Okumura, T.; Nakashima, H.

2013-12-01

The installed capacity of the geothermal power plants has been summed up to be about 515MW in Japan. However, the electricity generated by the geothermal resources only contributes to 0.2% of the whole electricity supply. After the catastrophic earthquake and tsunami devastated the Pacific coast of north-eastern Japan on Friday, March 11, 2011, the Japanese government is encouraging the increase of the renewable energy supply including the geothermal. It needs, however, more than 10 years to construct the geothermal power plant with more than 10MW capacity since the commencement of the development. Adding the problem of the long lead time, high temperature fluid is mainly observed in the national parks and the high quality of the geothermal resources is limited. On the other hand hot springs are often found. The utilisation of the low temperature hot water becomes worthy of notice. The low temperature hot water is traditionally used for bathing and there are many hot springs in Japan. Some of the springs have enough temperature and enthalpy to turn the geothermal turbine but a new technology of the binary power generation makes the lower temp fluid to generate electricity. Large power generators with the binary technology are already installed in many geothermal fields in the world. In the recent days small-scale geothermal binary generators with several tens to hundreds kW capacity are developed, which are originally used by the waste heat energy in an iron factory and so on. The newly developed binary unit is compact suitable for the installation in a Japanese inn but there are the restrictions for the temperature of the hot water and the working fluid. The binary power unit using alternatives for chlorofluorocarbon as the working fluid is relatively free from the restriction. KOBELCO, a company of the Kobe Steel Group, designed and developed the binary power unit with an alternative for chlorofluorocarbon. The unit has a 70 MW class electric generator. Three units have been installed in Obama Hot Spring area, Nagasaki Prefecture, where about 15,000 tonnes of hot water are produced in a day and more than 35% of the hot water flow directly to the sea. Another demonstration experiments are also conducted in several hot spring areas. In this study we will review several examples to utilise low temperature hot springs in Japan. Binary Power Unit at Obama (Fujino, 2013)

Yakima River Spring Chinook Enhancement Study, 1991 Final Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fast, David E.

1991-05-01

The population of Yakima River spring chinook salmon (Oncorhynchus tschawytscha) has been drastically reduced from historic levels reported to be as high as 250,000 adults (Smoker 1956). This reduction is the result of a series of problems including mainstem Columbia dams, dams within the Yakima itself, severely reduced flows due to irrigation diversions, outmigrant loss in irrigation canals, increased thermal and sediment loading, and overfishing. Despite these problems, the return of spring chinook to the Yakima River has continued at levels ranging from 854 to 9,442 adults since 1958. In October 1982, the Bonneville Power Administration contracted the Yakima Indianmore » Nation to develop methods to increase production of spring chinook in the Yakima system. The Yakima Nation's current enhancement policy attempts to maintain the genetic integrity of the spring chinook stock native to the Yakima Basin. Relatively small numbers of hatchery fish have been released into the basin in past years. The goal of this study was to develop data that will be used to present management alternatives for Yakima River spring chinook. A major objective of this study is to determine the distribution, abundance and survival of wild Yakima River spring chinook. The second major objective of this study is to determine the relative effectiveness of different methods of hatchery supplementation. The last three major objectives of the study are to locate and define areas in the watershed that may be used for the rearing of spring chinook; to define strategies for enhancing natural production of spring chinook in the Yakima River; and to determine the physical and biological limitations on production within the system. 47 refs., 89 figs., 67 tabs.« less

Yakima River Spring Chinook Enhancement Study Appendices, 1991 Final Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fast, David E.

1991-05-01

This document consists of the appendices for annual report DOE/BP/39461--9 which is summarized as follows. The population of Yakima River spring chinook salmon (Oncorhynchus tschawytscha) has been drastically reduced from historic levels reported to be as high as 250,000 adults (Smoker 1956). This reduction is the result of a series of problems including mainstem Columbia dams, dams within the Yakima itself, severely reduced flows due to irrigation diversions, outmigrant loss in irrigation canals, increased thermal and sediment loading, and overfishing. Despite these problems, the return of spring chinook to the Yakima River has continued at levels ranging from 854 tomore » 9,442 adults since 1958. In October 1982, the Bonneville Power Administration contracted the Yakima Indian Nation to develop methods to increase production of spring chinook in the Yakima system. The Yakima Nation's current enhancement policy attempts to maintain the genetic integrity of the spring chinook stock native to the Yakima Basin. Relatively small numbers of hatchery fish have been released into the basin in past years. The goal of this study was to develop data that will be used to present management alternatives for Yakima River spring chinook. A major objective of this study is to determine the distribution, abundance and survival of wild Yakima River spring chinook. The second major objective of this study is to determine the relative effectiveness of different methods of hatchery supplementation. The last three major objectives of the study are to locate and define areas in the watershed that may be used for the rearing of spring chinook; to define strategies for enhancing natural production of spring chinook in the Yakima River; and to determine the physical and biological limitations on production within the system.« less

Zeaxanthin-independent energy quenching and alternative electron sinks cause a decoupling of the relationship between the photochemical reflectance index (PRI) and photosynthesis in an evergreen conifer during spring.

PubMed

Fréchette, Emmanuelle; Wong, Christopher Y S; Junker, Laura Verena; Chang, Christine Yao-Yun; Ensminger, Ingo

2015-12-01

In evergreen conifers, the winter down-regulation of photosynthesis and its recovery during spring are the result of a reorganization of the chloroplast and adjustments of energy-quenching mechanisms. These phenological changes may remain undetected by remote sensing, as conifers retain green foliage during periods of photosynthetic down-regulation. The aim was to assess if the timing of the spring recovery of photosynthesis and energy-quenching characteristics are accurately monitored by the photochemical reflectance index (PRI) in the evergreen conifer Pinus strobus. The recovery of photosynthesis was studied using chlorophyll fluorescence, leaf gas exchange, leaf spectral reflectance, and photosynthetic pigment measurements. To assess if climate change might affect the recovery of photosynthesis, seedlings were exposed to cold spring conditions or warm spring conditions with elevated temperature. An early spring decoupling of the relationship between photosynthesis and PRI in both treatments was observed. This was caused by differences between the timing of the recovery of photosynthesis and the timing of carotenoid and chlorophyll pool size adjustments which are the main factors controlling PRI during spring. It was also demonstrated that zeaxanthin-independent NPQ mechanisms undetected by PRI further contributed to the early spring decoupling of the PRI-LUE relationship. An important mechanism undetected by PRI seems to involve increased electron transport around photosystem I, which was a significant energy sink during the entire spring transition, particularly in needles exposed to a combination of high light and cold temperatures. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Practice schedules for surgical skills: the role of task characteristics and proactive interference on psychomotor skills acquisition.

PubMed

Willis, Ross E; Curry, Eileen; Gomez, Pedro Pablo

2013-01-01

Although break periods during training sessions are desirable, it is unclear what learners should do during these breaks. Some educators recommend that learners abstain from all task-related practice; however, it is possible that switching to an alternate exercise during break periods can also be effective. The construct of proactive interference (PI) posits that new learning is disrupted by prior learning. PI can be "released" when the nature of the task is changed after several practice trials. In this study, we examined the existence of PI in motor learning under 5 training conditions that differed in contrast to a target exercise. Preclinical medical students (n = 75) performed 1 trial of peg transfer as a pretest. Participants were then randomly assigned to 1 of 5 training conditions: mass practice, similar exercise (laparoscopic bean transfer), dissimilar exercise (open suturing), observation, or rest. Participants in the mass practice condition practiced peg transfer in 3 training blocks of 15 minutes, each separated by a 5-minute break. Participants in the other conditions performed 3 training blocks consisting of 15 minutes of peg transfer followed by an interspersed alternate exercise. On completion of 3 training blocks, participants performed 1 additional peg transfer trial as a posttest. Despite having trained for the same amount of time on the target task, Analysis of Covariance on posttest scores using pretest scores as the covariate indicated a significant main effect for training condition (p = 0.009). Participants engaging in mass practice performed significantly worse than participants in the dissimilar (p = 0.012), observation (p = 0.022), and rest (p < 0.001) conditions. Additionally, participants in the similar exercise condition performed worse than participants in the rest condition (p = 0.03). When learning a laparoscopic task, a break comprised of dissimilar practice or unrelated activities is effective in releasing PI and improving performance. © 2013 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Break-even analysis of costs for controlling Toxoplasma gondii infections in slaughter pigs via a serological surveillance program in the Netherlands.

PubMed

van Asseldonk, M; van Wagenberg, C P A; Wisselink, H J

2017-03-01

Toxoplasma gondii (T. gondii) is a food safety hazard which causes a substantial human disease burden and cost-of-illness. Infected pig meat is a common source of toxoplasmosis. A break-even analysis was conducted to estimate the point for which the intervention cost at fattening pig farms equaled the cost of averted human disease burden and cost-of-illness minus the costs of a T. gondii surveillance program. The surveillance program comprised serological testing of blood samples taken at slaughter. Break-even points were determined given alternative levels of the effectiveness of the intervention program (10% up to 90% in steps of 10%), the value of an averted DALY (20,000, 50,000 and 80,000 Euro), and threshold of sample prevalence for a farm to be under intervention (5% up to 50% out of 20 samples in steps of 5%). Since test characteristics are a determining factor in the break-even analysis, and literature is inconclusive concerning sensitivity (se) and specificity (sp) of the serological test kit used, two alternative sets of assumptions were analysed. The estimated maximum costs of an intervention if only benefits for domestic consumers were accounted amounted approximately 2981 Euro (se=98.9% and sp=92.7%) versus 4389 Euro (se=65.2% and sp=97.4%) per year per fattening pig farm under intervention assuming an effectiveness of 50%, 50,000 Euro per averted DALY and threshold T. gondii sample prevalence of 5% for a farm to be under intervention. Since almost 80% of the gross domestic production is exported corresponding break-even values increased up to 12,034 Euro and 18,366 Euro if benefits for consumers abroad were included as well. Empirical research to strengthen the knowledge about the efficacy of a farm intervention measures is recommended. Copyright © 2017 Elsevier B.V. All rights reserved.

The Spatial Pattern and Interactions of Woody Plants on the Temperate Savanna of Inner Mongolia, China: The Effects of Alternating Seasonal Grazing-Mowing Regimes

PubMed Central

2015-01-01

Ulmus pumila tree-dominated temperate savanna, which is distributed widely throughout the forest-steppe ecotone on the Mongolian Plateau, is a relatively stable woody-herbaceous complex ecosystem in northern China. Relatively more attention has been paid to the degradation of typical steppe areas, whereas less focus has been placed on the succession of this typical temperate savanna under the present management regime. In this study, we established 3 sample plots 100 m×100 m in size along a gradient of fixed distances from one herder’s stationary site and then surveyed all the woody plants in these plots. A spatial point pattern analysis was employed to clarify the spatial distribution and interaction of these woody plants. The results indicated that old U. pumila trees (DBH ≥ 20 cm) showed a random distribution and that medium U. pumila trees (5 cm ≤ DBH < 20 cm) showed an aggregated distribution at a smaller scale and a random distribution at a larger scale; few or no juvenile trees (DBH < 5 cm) were present, and seedlings (without DBH) formed aggregations in all 3 plots. These findings can be explained by an alternate seasonal grazing-mowing regime (exclosure in summer, mowing in autumn and grazing in winter and spring); the shrubs in all 3 plots exist along a grazing gradient that harbors xerophytic and mesophytic shrubs. Of these shrubs, xerophytic shrubs show significant aggregation at a smaller scale (0-5.5 m), whereas mesophytic shrubs show significant aggregation at a larger scale (0-25 m), which may be the result of the dual effects of grazing pressure and climate change. Medium trees and seedlings significantly facilitate the distributions of xerophytic shrubs and compete significantly with mesophytic shrubs due to differences in water use strategies. We conclude that the implementation of an alternative grazing-mowing regime results in xerophytic shrub encroachment or existence, breaking the chain of normal succession in a U. pumila tree community in this typical temperate savanna ecosystem. This might eventually result in the degradation of the original tree-dominated savanna to a xerophytic shrub-dominated savanna. PMID:26196956

Engineering evaluation/cost analysis for the proposed management of 15 nonprocess buildings (15 series) at the Weldon Spring Site Chemical Plant, Weldon Spring, Missouri. Environmental assessment: Weldon Spring Site Remedial Action Project, Weldon Spring, Missouri

DOE Office of Scientific and Technical Information (OSTI.GOV)

MacDonell, M.M.; Peterson, J.M.

1991-11-01

The US Department of Energy, under its Surplus Facilities Management Program (SFMP), is responsible for cleanup activities at the Weldon Spring site, located near Weldon Spring, Missouri. The site consists of two noncontiguous areas: (1) a raffinate pits and chemical plant area and (2) a quarry. This engineering evaluation/cost analysis (EE/CA) report has been prepared to support a proposed removal action to manage 15 nonprocess buildings, identified as the 15 Series buildings, at the chemical plant on the Weldon Spring site. These buildings have been nonoperational for more than 20 years, and the deterioration that has occurred during this timemore » has resulted in a potential threat to site workers, the general public, and the environment. The EE/CA documentation of this proposed action is consistent with guidance from the US Environmental Protection Agency (EPA) that addresses removal actions at sites subject to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980, as amended by the Superfund Amendments and Reauthorization Act of 1986. Actions at the Weldon Spring site are subject to CERCLA requirements because the site is on the EPA`s National Priorities List. The objectives of this report are to (1) identify alternatives for management of the nonprocess buildings; (2) document the selection of response activities that will mitigate the potential threat to workers, the public, and the environment associated with these buildings; and (3) address environmental impact associated with the proposed action.« less

Cubical Mass-Spring Model design based on a tensile deformation test and nonlinear material model.

PubMed

San-Vicente, Gaizka; Aguinaga, Iker; Tomás Celigüeta, Juan

2012-02-01

Mass-Spring Models (MSMs) are used to simulate the mechanical behavior of deformable bodies such as soft tissues in medical applications. Although they are fast to compute, they lack accuracy and their design remains still a great challenge. The major difficulties in building realistic MSMs lie on the spring stiffness estimation and the topology identification. In this work, the mechanical behavior of MSMs under tensile loads is analyzed before studying the spring stiffness estimation. In particular, the performed qualitative and quantitative analysis of the behavior of cubical MSMs shows that they have a nonlinear response similar to hyperelastic material models. According to this behavior, a new method for spring stiffness estimation valid for linear and nonlinear material models is proposed. This method adjusts the stress-strain and compressibility curves to a given reference behavior. The accuracy of the MSMs designed with this method is tested taking as reference some soft-tissue simulations based on nonlinear Finite Element Method (FEM). The obtained results show that MSMs can be designed to realistically model the behavior of hyperelastic materials such as soft tissues and can become an interesting alternative to other approaches such as nonlinear FEM.

Spitzer Observations of OGLE-2015-BLG-1212 Reveal a New Path toward Breaking Strong Microlens Degeneracies

NASA Technical Reports Server (NTRS)

Bozza, V.; Shvartzvald, Y.; Udalski, A.; Novati, S.Calchi; Bond, I. A.; Han, C.; Hundertmark, M.; Poleski, R.; Pawlak, M.; Szymanski, M. K.;

Aircraft interior noise reduction by alternate resonance tuning

NASA Technical Reports Server (NTRS)

Gottwald, James A.; Bliss, Donald B.

1990-01-01

The focus is on a noise control method which considers aircraft fuselages lined with panels alternately tuned to frequencies above and below the frequency that must be attenuated. An interior noise reduction called alternate resonance tuning (ART) is described both theoretically and experimentally. Problems dealing with tuning single paneled wall structures for optimum noise reduction using the ART methodology are presented, and three theoretical problems are analyzed. The first analysis is a three dimensional, full acoustic solution for tuning a panel wall composed of repeating sections with four different panel tunings within that section, where the panels are modeled as idealized spring-mass-damper systems. The second analysis is a two dimensional, full acoustic solution for a panel geometry influenced by the effect of a propagating external pressure field such as that which might be associated with propeller passage by a fuselage. To reduce the analysis complexity, idealized spring-mass-damper panels are again employed. The final theoretical analysis presents the general four panel problem with real panel sections, where the effect of higher structural modes is discussed. Results from an experimental program highlight real applications of the ART concept and show the effectiveness of the tuning on real structures.

Mechanisms Governing Interannual Variability of Stratosphere-to-Troposphere Ozone Transport

NASA Astrophysics Data System (ADS)

Albers, John R.; Perlwitz, Judith; Butler, Amy H.; Birner, Thomas; Kiladis, George N.; Lawrence, Zachary D.; Manney, Gloria L.; Langford, Andrew O.; Dias, Juliana

2018-01-01

Factors governing the strength and frequency of stratospheric ozone intrusions over the Pacific-North American region are considered for their role in modulating tropospheric ozone on interannual timescales. The strength of the association between two major modes of climate variability—the El Niño-Southern Oscillation (ENSO) and the Northern Annular Mode (NAM)—and the amount of ozone contained in stratospheric intrusions are tested in the context of two mechanisms that modulate stratosphere-to-troposphere transport (STT) of ozone: (StratVarO3) the winter season buildup of ozone abundances in the lowermost stratosphere (LMS) and (JetVar) Pacific jet and wave breaking variability during spring. In essence, StratVarO3 corresponds to variability in the amount of ozone per intrusion, while JetVar governs the frequency of intrusions. The resulting analysis, based on two different reanalysis products, suggests that StratVarO3 is more important than JetVar for driving interannual variations in STT of ozone over the Pacific-North American region. In particular, the abundance of ozone in the LMS at the end of winter is shown to be a robust indicator of the amount of ozone that will be contained in stratospheric intrusions during the ensuing spring. Additionally, it is shown that the overall strength of the winter season stratospheric NAM is a useful predictor of ozone intrusion strength. The results also suggest a nuanced relationship between the phase of ENSO and STT of ozone. While ENSO-related jet variability is associated with STT variability, it is wave breaking frequency rather than typical ENSO teleconnection patterns that is responsible for the ENSO-STT relationship.

Intermediate complex morphophysiological dormancy in seeds of the cold desert sand dune geophyte Eremurus anisopterus (Xanthorrhoeaceae; Liliaceae s.l.)

PubMed Central

Mamut, Jannathan; Tan, Dun Yan; Baskin, Carol C.; Baskin, Jerry M.

2014-01-01

Background and Aims Little is known about morphological (MD) or morphophysiological (MPD) dormancy in cold desert species and in particular those in Liliaceae sensu lato, an important floristic element in the cold deserts of Central Asia with underdeveloped embyos. The primary aim of this study was to determine if seeds of the cold desert liliaceous perennial ephemeral Eremurus anisopterus has MD or MPD, and, if it is MPD, then at what level. Methods Embryo growth and germination was monitored in seeds subjected to natural and simulated natural temperature regimes and the effects of after-ripening and GA3 on dormancy break were tested. In addition, the temperature requirements for embryo growth and dormancy break were investigated. Key Results At the time of seed dispersal in summer, the embryo length:seed length (E:S) ratio was 0·73, but it increased to 0·87 before germination. Fresh seeds did not germinate during 1 month of incubation in either light or darkness over a range of temperatures. Thus, seeds have MPD, and, after >12 weeks incubation at 5/2 °C, both embryo growth and germination occurred, showing that they have a complex level of MPD. Since both after-ripening and GA3 increase the germination percentage, seeds have intermediate complex MPD. Conclusions Embryos in after-ripened seeds of E. anisopterus can grow at low temperatures in late autumn, but if the soil is dry in autumn then growth is delayed until snowmelt wets the soil in early spring. The ecological advantage of embryo growth phenology is that seeds can germinate at a time (spring) when sand moisture conditions in the desert are suitable for seedling establishment. PMID:25180288

An Examination of Test-Retest, Alternate Form Reliability, and Generalizability Theory Study of the easyCBM Reading Assessments: Grade 2. Technical Report #1217

ERIC Educational Resources Information Center

Anderson, Daniel; Lai, Cheg-Fei; Park, Bitnara Jasmine; Alonzo, Julie; Tindal, Gerald

2012-01-01

This technical report is one in a series of five describing the reliability (test/retest an alternate form) and G-Theory/D-Study on the easyCBM reading measures, grades 1-5. Data were gathered in the spring of 2011 from the convenience sample of students nested within classrooms at a medium-sized school district in the Pacific Northwest. Due to…

An Examination of Test-Retest, Alternate Form Reliability, and Generalizability Theory Study of the easyCBM Reading Assessments: Grade 5. Technical Report #1220

ERIC Educational Resources Information Center

Lai, Cheng-Fei; Park, Bitnara Jasmine; Anderson, Daniel; Alonzo, Julie; Tindal, Gerald

2012-01-01

This technical report is one in a series of five describing the reliability (test/retest and alternate form) and G-Theory/D-Study research on the easyCBM reading measures, grades 1-5. Data were gathered in the spring of 2011 from a convenience sample of students nested within classrooms at a medium-sized school district in the Pacific Northwest.…

An Examination of Test-Retest, Alternate Form Reliability, and Generalizability Theory Study of the easyCBM Passage Reading Fluency Assessments: Grade 4. Technical Report #1219

ERIC Educational Resources Information Center

Park, Bitnara Jasmine; Anderson, Daniel; Alonzo, Julie; Lai, Cheng-Fei; Tindal, Gerald

2012-01-01

This technical report is one in a series of five describing the reliability (test/retest and alternate form) and G-Theory/D-Study research on the easyCBM reading measures, grades 1-5. Data were gathered in the spring of 2011 from a convenience sample of students nested within classrooms at a medium-sized school district in the Pacific Northwest.…

Oyster Shell Dredging in Atchafalaya Bay and Adjacent Waters, Louisiana. Volume 2. Public Comments.

DTIC Science & Technology

1987-11-01

alternatives to the proposed action." (NEPA Sec. 102(C)(iii)) To either renew the permits or deny the permits essentially provides no alternatives...of the more marine-oriented fishes found in the Gulf of Mexico enter these regions, essentially using them as nursery grounds. Shell dredging will...and the release in summer is probably essential to the sustained phytoplankton production observed in Fourleague Bay throughout the spring to fall

Quantitative analysis of the thermal requirements for stepwise physical dormancy-break in seeds of the winter annual Geranium carolinianum (Geraniaceae)

PubMed Central

Gama-Arachchige, N. S.; Baskin, J. M.; Geneve, R. L.; Baskin, C. C.

2013-01-01

Background and Aims Physical dormancy (PY)-break in some annual plant species is a two-step process controlled by two different temperature and/or moisture regimes. The thermal time model has been used to quantify PY-break in several species of Fabaceae, but not to describe stepwise PY-break. The primary aims of this study were to quantify the thermal requirement for sensitivity induction by developing a thermal time model and to propose a mechanism for stepwise PY-breaking in the winter annual Geranium carolinianum. Methods Seeds of G. carolinianum were stored under dry conditions at different constant and alternating temperatures to induce sensitivity (step I). Sensitivity induction was analysed based on the thermal time approach using the Gompertz function. The effect of temperature on step II was studied by incubating sensitive seeds at low temperatures. Scanning electron microscopy, penetrometer techniques, and different humidity levels and temperatures were used to explain the mechanism of stepwise PY-break. Key Results The base temperature (Tb) for sensitivity induction was 17·2 °C and constant for all seed fractions of the population. Thermal time for sensitivity induction during step I in the PY-breaking process agreed with the three-parameter Gompertz model. Step II (PY-break) did not agree with the thermal time concept. Q10 values for the rate of sensitivity induction and PY-break were between 2·0 and 3·5 and between 0·02 and 0·1, respectively. The force required to separate the water gap palisade layer from the sub-palisade layer was significantly reduced after sensitivity induction. Conclusions Step I and step II in PY-breaking of G. carolinianum are controlled by chemical and physical processes, respectively. This study indicates the feasibility of applying the developed thermal time model to predict or manipulate sensitivity induction in seeds with two-step PY-breaking processes. The model is the first and most detailed one yet developed for sensitivity induction in PY-break. PMID:23456728

Tracking the seasonal cycle of coastal sea ice: Community-based observations and satellite remote sensing in service of societal needs

NASA Astrophysics Data System (ADS)

Eicken, Hajo; Lee, Olivia A.; Johnson, Mark A.; Pulsifer, Peter; Danielsen, Finn

2017-04-01

Break-up and freeze-up of coastal sea ice determine the timing and extent of a number of human activities, ranging from ice use by Indigenous hunters to coastal shipping. Yet, while major reductions in the extent of Arctic summer sea ice have been well studied, changes in its seasonal cycle have received less attention. Here, we discuss decadal scale changes and interannual variability in the timing of spring break-up and fall freeze-up, with a focus on coastal communities in Arctic Alaska. Observations of ice conditions by Indigenous sea-ice experts since 2006 indicate significant interannual variability in both the character and timing of freeze-up and break-up in the region. To aid in the archival and sharing of such observations, we have developed a database for community ice observations (eloka-arctic.org/sizonet). Development of this database addressed key questions ranging from community guidance on different levels of data sharing and access to the development of protocols that may lend themselves for implementation in the context of operational programs such as Global Cryosphere Watch. The lessons learned and tools developed through this effort may help foster the emergence of common observation protocols and sharing practices across the Arctic, as explored jointly with the Greenlandic PISUNA initiative and the European INTAROS project. For the Arctic Alaska region, we developed an algorithm to extract the timing of break-up and freeze-up from passive microwave satellite data, drawing on community-based observations. Data from 1979 to 2013 show break-up start arriving earlier by 5-9 days per decade and freeze-up start arriving later by 7-14 days per decade in the Chukchi and Beaufort Seas. The trends towards a shorter ice season observed over the past several decades point towards a substantial change in the winter ice regime by mid-century with incipient overlap of the end of the freeze-up and start of the break-up season as defined by coastal ice users.

Sensitivity cycling in physically dormant seeds of the Neotropical tree Senna multijuga (Fabaceae).

PubMed

Rodrigues-Junior, A G; Baskin, C C; Baskin, J M; Garcia, Q S

2018-03-23

Cycling of sensitivity to physical dormancy (PY) break has been documented in herbaceous species. However, it has not been reported in tree seeds, nor has the effect of seed size on sensitivity to PY-breaking been evaluated in any species. Thus, the aims of this study were to investigate how PY is broken in seeds of the tropical legume tree Senna multijuga, if seeds exhibit sensitivity cycling and if seed size affects induction into sensitivity. Dormancy and germination were evaluated in intact and scarified seeds from two collections of S. multijuga. The effects of temperature, moisture and seed size on induction of sensitivity to dormancy-breaking were assessed, and seasonal changes in germination and persistence of buried seeds were determined. Reversal of sensitivity was also investigated. Fresh seeds were insensitive to dormancy break at wet-high temperatures, and an increase in sensitivity occurred in buried seeds after they experienced low temperatures during winter (dry season). Temperatures ≤20 °C increased sensitivity, whereas temperatures ≥30 °C decreased it regardless of moisture conditions. Dormancy was broken in sensitive seeds by incubating them at 35 °C. Sensitivity could be reversed, and large seeds were more sensitive than small seeds to sensitivity induction. Seeds of S. multijuga exhibit sensitivity cycling to PY-breaking. Seeds become sensitive during winter and can germinate with the onset of the spring-summer rainy season in Brazil. Small seeds are slower to become sensitive than large ones, and this may be a mechanism by which germination is spread over time. Sensitive seeds that fail to germinate become insensitive during exposure to drought during summer. This is the first report of sensitivity cycling in a tree species. © 2018 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.

Short-finned Pilot Whales (Globicephala macrorhynchus) Target Gulf Stream and Shelf Break Waters in the U.S. Mid-Atlantic Bight

NASA Astrophysics Data System (ADS)

Thorne, L. H.; Foley, H.; Webster, D.; Baird, R.; Swaim, Z.; Read, A.

2016-02-01

Short-finned pilot whales (Globicephala macrorhynchus) are deep-diving predators that feed on squid and regularly exploit prey at depths of more than 500 m. Detailed information on the habitat use of pilot whales in the Northwest Atlantic is lacking, which complicates management of the species, particularly for efforts to mitigate bycatch and depredation in the pelagic longline fishery. To address this limitation, we tracked the horizontal and vertical movements of short-finned pilot whales with LIMPET satellite-linked transmitters off Cape Hatteras, North Carolina, in 2014. We deployed 14 satellite tags and 4 satellite-linked depth recording tags, with deployments of 2 to 194 days (mean=57 days). Using randomly-generated temporally-matched pseudo-absences with modeled distance constraints and mixed-effects generalized additive models (GAMMs), we evaluated pilot whale movement relative to environmental variables (distance to shelf break, sea surface temperature SST), location of Gulf Stream, bathymetric slope, and depth). Pilot whales showed two types of behavior, showing a strong affinity for either the shelf break or waters of the Gulf Stream. Slope, distance to shelf break, and SST were significant predictors of habitat use (p<<0.001 for all variables, R2=0.40). Pilot whales demonstrated a preference for waters close to the shelf break, with warmer SST values (peak preference 25°C) and medium to high bathymetric slopes (peak preference 40 percent rise). We observed seasonal patterns in pilot whale movements, with whales diving to deeper depths in late summer and fall months than in spring months (Wilcoxon test, p<<0.001). Diving behavior was also significantly influenced by SST; pilot whales took longer and deeper dives in warmer waters (Pearson's correlation coefficients >0.40, p<<0.001). We use these results to develop spatial maps of pilot whale habitat relative to seasonal and environmental factors in order to identify areas and times of high risk for interactions between pilot whales and longline gear.

Electrothermal fracturing of tensile specimens

NASA Technical Reports Server (NTRS)

Blinn, H. O.; Hanks, J. G.; Perkins, H. P.

1970-01-01

Pulling device consisting of structural tube, connecting rod, spring-loaded nuts, loading rod, heating element, and three bulkheads fractures tensile specimens. Alternate heating and cooling increases tensile loading by increments until fracturing occurs. Load cell or strain gage, applied to pulling rod, determines forces applied.

76 FR 9000 - Foreign-Trade Zone 29-Louisville, KY, Application for Expansion of Manufacturing Authority...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-16

..., springs, brackets, plates, filters, bearings, air pumps/compressors, valves, switches, electric motors..., clutches, parts of electric motors, pinions, magnets, ignition parts, diodes, transistors, resistors... and chambers, starter motors, motor/generator units, alternators, distributors, other static...

Comparative study of the silica and cation geothermometry of the Malawi hot springs: Potential alternative energy source

NASA Astrophysics Data System (ADS)

Dulanya, Zuze; Morales-Simfors, Nury; Sivertun, Åke

2010-06-01

Malawi is one of the poorest countries in the world and one of the most densely populated in south-eastern Africa. Its major power source is hydro-electricity. During the past few years, the power generation capacity has been reduced, which has impacted negatively on the socio-economic development of the country. The country holds an enormous potential to generate geothermal energy due to the country's position within the Great African Rift valley. This could contribute to economic growth, poverty reduction and technological development in Malawi. The paper presents findings of research on comparisons between silica (quartz and chalcedony) and cation geothermometers (Na-K, Na-K-Ca and K-Mg) of hot springs in the Malawi Rift, in order to deduce the temperature at depth of selected hot springs. The saturation indices of most springs have a bearing on the geology of the areas where these hot springs are found. The Na-K geothermometers are, in general, higher than the Na-K-Ca geothermometer and the K-Mg geothermometer shows temperatures that are too low to be considered. The difference in the results between the different geothermometers may indicate shallow conditions of mixing with groundwater. Results also indicate that some hot springs have sufficient heat-generating capabilities and warrant further exploration work to assess their suitability for energy generation.

Geohydrology, geochemistry, geothermal potency of Rianiate Toba Lake North Sumatera

NASA Astrophysics Data System (ADS)

Nainggolan, Juliper; Sitepu, Cristin; Pardede, Sanggam; Diantoro, Markus

2017-09-01

This research was performed to determine the potency of Rianiate’s geothermal an alternative of energy source and determine the types of geothermal that was begun with the position’s measurement by using GPS (Global Position System), and then the direct observation of chemical and physical properties such as pH, surface’s temperature, color etc. The following steps were taking sample in four different springs indicated by spring 1, spring 2, spring 3, and spring 4. The chemical nature was measured by titrimetry method by using AAS, XRD, and gas Chromathology. The calculating of temperature of subsurface has done by using geothermometer and sequentially followed by geothermal potency’s calculation. The position of four springs are located about N: 02° 31,852’ and E: 098° 44. 021’ where were average height from sea’s level is 958 m. The highest surface’s temperature is 80 °C and the temperature under soil is about 130.5 °C described the average of geothermal. The calculation of content of chloride, sulfate, bicarbonations revealed that the water can be categorized as chloride type. The trilateral diagram Na/1000 - K/100 - √Mg of hot water is in the regime of immature water. From the calculation of Indonesia’s Standardized Geotherm, it was obtained that the estimated reservoir potency of Rianiate geotherm is 2,68 MWe.

Patterns of late spring frost leaf damage and recovery in a European beech (Fagus sylvatica L.) stand in south-eastern Germany based on repeated digital photographs

PubMed Central

Menzel, Annette; Helm, Raimund; Zang, Christian

2015-01-01

Damage by late spring frost is a risk deciduous trees have to cope with in order to optimize the length of their growing season. The timing of spring phenological development plays a crucial role, not only at the species level, but also at the population and individual level, since fresh new leaves are especially vulnerable. For the pronounced late spring frost in May 2011 in Germany, we studied the individual leaf development of 35 deciduous trees (mainly European beech Fagus sylvatica L.) at a mountainous forest site in the Bayerischer Wald National Park using repeated digital photographs. Analyses of the time series of greenness by a novel Bayesian multiple change point approach mostly revealed five change points which almost perfectly matched the expected break points in leaf development: (i) start of the first greening between day of the year (DOY) 108–119 (mean 113), (ii) end of greening, and (iii) visible frost damage after the frost on the night of May 3rd/4th (DOY 123/124), (iv) re-sprouting 19–38 days after the frost, and (v) full maturity around DOY 178 (166–184) when all beech crowns had fully recovered. Since frost damage was nearly 100%, individual susceptibility did not depend on the timing of first spring leaf unfolding. However, we could identify significant patterns in fitness linked to an earlier start of leaf unfolding. Those individuals that had an earlier start of greening during the first flushing period had a shorter period of recovery and started the second greening earlier. Thus, phenological timing triggered the speed of recovery from such an extreme event. The maximum greenness achieved, however, did not vary with leaf unfolding dates. Two mountain ashes (Sorbus aucuparia L.) were not affected by the low temperatures of -5°C. Time series analysis of webcam pictures can thus improve process-based knowledge and provide valuable insights into the link between phenological variation, late spring frost damage, and recovery within one stand. PMID:25759707

Correlation of geothermal springs with sub-surface fault terminations revealed by high-resolution, UAV-acquired magnetic data

USGS Publications Warehouse

Glen, Jonathan; A.E. Egger,; C. Ippolito,; N.Athens,

2013-01-01

There is widespread agreement that geothermal springs in extensional geothermal systems are concentrated at fault tips and in fault interaction zones where porosity and permeability are dynamically maintained (Curewitz and Karson, 1997; Faulds et al., 2010). Making these spatial correlations typically involves geological and geophysical studies in order to map structures and their relationship to springs at the surface. Geophysical studies include gravity and magnetic surveys, which are useful for identifying buried, intra-basin structures, especially in areas where highly magnetic, dense mafic volcanic rocks are interbedded with, and faulted against less magnetic, less dense sedimentary rock. High-resolution magnetic data can also be collected from the air in order to provide continuous coverage. Unmanned aerial systems (UAS) are well-suited for conducting these surveys as they can provide uniform, low-altitude, high-resolution coverage of an area without endangering crew. In addition, they are more easily adaptable to changes in flight plans as data are collected, and improve efficiency. We have developed and tested a new system to collect magnetic data using small-platform UAS. We deployed this new system in Surprise Valley, CA, in September, 2012, on NASA's SIERRA UAS to perform a reconnaissance survey of the entire valley as well as detailed surveys in key transition zones. This survey has enabled us to trace magnetic anomalies seen in ground-based profiles along their length. Most prominent of these is an intra-basin magnetic high that we interpret as a buried, faulted mafic dike that runs a significant length of the valley. Though this feature lacks surface expression, it appears to control the location of geothermal springs. All of the major hot springs on the east side of the valley lie along the edge of the high, and more specifically, at structural transitions where the high undergoes steps, bends, or breaks. The close relationship between the springs and structure terminations revealed by this study is unprecedented. Collecting magnetic data via UAS represents a new capability in geothermal exploration of remote and dangerous areas that significantly enhances our ability to map the subsurface.

Patterns of late spring frost leaf damage and recovery in a European beech (Fagus sylvatica L.) stand in south-eastern Germany based on repeated digital photographs.

PubMed

Menzel, Annette; Helm, Raimund; Zang, Christian

2015-01-01

Damage by late spring frost is a risk deciduous trees have to cope with in order to optimize the length of their growing season. The timing of spring phenological development plays a crucial role, not only at the species level, but also at the population and individual level, since fresh new leaves are especially vulnerable. For the pronounced late spring frost in May 2011 in Germany, we studied the individual leaf development of 35 deciduous trees (mainly European beech Fagus sylvatica L.) at a mountainous forest site in the Bayerischer Wald National Park using repeated digital photographs. Analyses of the time series of greenness by a novel Bayesian multiple change point approach mostly revealed five change points which almost perfectly matched the expected break points in leaf development: (i) start of the first greening between day of the year (DOY) 108-119 (mean 113), (ii) end of greening, and (iii) visible frost damage after the frost on the night of May 3rd/4th (DOY 123/124), (iv) re-sprouting 19-38 days after the frost, and (v) full maturity around DOY 178 (166-184) when all beech crowns had fully recovered. Since frost damage was nearly 100%, individual susceptibility did not depend on the timing of first spring leaf unfolding. However, we could identify significant patterns in fitness linked to an earlier start of leaf unfolding. Those individuals that had an earlier start of greening during the first flushing period had a shorter period of recovery and started the second greening earlier. Thus, phenological timing triggered the speed of recovery from such an extreme event. The maximum greenness achieved, however, did not vary with leaf unfolding dates. Two mountain ashes (Sorbus aucuparia L.) were not affected by the low temperatures of -5°C. Time series analysis of webcam pictures can thus improve process-based knowledge and provide valuable insights into the link between phenological variation, late spring frost damage, and recovery within one stand.

Genetic and environmental control of seasonal carbohydrate dynamics in trees of diverse Pinus sylvestris populations.

PubMed

Oleksyn, J.; Zytkowiak, R.; Karolewski, P.; Reich, P. B.; Tjoelker, M. G.

2000-06-01

We explored environmental and genetic factors affecting seasonal dynamics of starch and soluble nonstructural carbohydrates in needle and twig cohorts and roots of Scots pine (Pinus sylvestris L.) trees of six populations originating between 49 degrees and 60 degrees N, and grown under common garden conditions in western Poland. Trees of each population were sampled once or twice per month over a 3-year period from age 15 to 17 years. Based on similarity in starch concentration patterns in needles, two distinct groups of populations were identified; one comprised northern populations from Sweden and Russia (59-60 degrees N), and another comprised central European populations from Latvia, Poland, Germany and France (49-56 degrees N). Needle starch concentrations of northern populations started to decline in late spring and reached minimum values earlier than those of central populations. For all populations, starch accumulation in spring started when minimum air temperature permanently exceeded 0 degrees C. Starch accumulation peaked before bud break and was highest in 1-year-old needles, averaging 9-13% of dry mass. Soluble carbohydrate concentrations were lowest in spring and summer and highest in autumn and winter. There were no differences among populations in seasonal pattern of soluble carbohydrate concentrations. Averaged across all populations, needle soluble carbohydrate concentrations increased from about 4% of needle dry mass in developing current-year needles, to about 9% in 1- and 2-year-old needles. Root carbohydrate concentration exhibited a bimodal pattern with peaks in spring and autumn. Northern populations had higher concentrations of fine-root starch in spring and autumn than central populations. Late-summer carbohydrate accumulation in roots started only after depletion of starch in needles and woody shoots. We conclude that Scots pine carbohydrate dynamics depend partially on inherited properties that are probably related to phenology of root and shoot growth.

Yakima Fisheries Project : Final Environmental Impact Statement.

DOE Office of Scientific and Technical Information (OSTI.GOV)

United States. Bonneville Power Administration; Washington; Confederated Tribes and Bands of the Yakama Nation, Washington.

1996-01-01

BPA proposes to fund several fishery-related activities in the Yakima River Basin. These activities, known as the Yakima Fisheries Project (YFP), would be jointly managed by the State of Washington and the Yakima Indian Nation. The YFP is included in the Northwest Power Planning Council`s (Council`s) fish and wildlife program. The Council selected the Yakima River system for attention because fisheries resources are severely reduced from historical levels and because there is a significant potential for enhancement of these resources. BPA`s proposed action is to fund (1) information gathering on the implementation of supplementation techniques and on feasibility of reintroducingmore » coho salmon in an environment where native populations have become extinct; (2) research activities based on continuous assessment, feedback and improvement of research design and activities ({open_quotes}adaptive management{close_quotes}); and (3) die construction, operation, and maintenance of facilities for supplementing populations of upper Yakima spring chinook salmon. Examined in addition to No Action are two alternatives for action: (1) supplementation of depressed natural populations of upper Yakima spring chinook and (2) that same supplementation plus a study to determine the feasibility of reestablishing naturally spawning population and a significant fall fishery for coho in the Yakima Basin. Alternative 2 is the preferred action. A central hatchery would be built for either alternative, as well as three sites with six raceways each for acclimation and release of spring chinook smolts. Major issues examined in the Revised Draft EIS include potential impacts of the project on genetic and ecological resources of existing fish populations, on water quality and quantity, on threatened and endangered species listed under the Endangered Species Act, and on the recreational fishery.« less

Alternative antiretroviral therapy formulations for patients unable to swallow solid oral dosage forms.

PubMed

Duggan, Joan M; Akpanudo, Barbara; Shukla, Vipul; Gutterson, Glen; Eitniear, Lindsey; Sahloff, Eric G

2015-09-15

Evidence-based guidance is presented to assist clinicians in selecting alternative formulations of antiretroviral (ARV) agents for patients with human immunodeficiency virus (HIV) infection who are unable to swallow tablets or capsules. The inability to take medications in standard oral dosage forms can be associated with nonadherence or the use of alternative administration strategies such as capsule or tablet breaking, crushing, or chewing. Patients with HIV infection require long-term ARV therapy to maintain viral suppression; ARV agents are predominately available as tablets and capsules that may pose swallowing difficulties for some patients. Using a variety of sources (the primary literature, pharmaceutical package inserts, and requests for unpublished data from drug manufacturers), available evidence on the bioavailability of ARV medications after disruption of the capsule or tablet matrix was reviewed; information on alternative formulations of ARV agents was also assessed. With several ARV agents, disruption of the solid oral dosage form by crushing, chewing, or breaking tablets or opening capsules prior to ingestion has been shown to result in altered bioavailability or pharmacokinetics and thus the potential for incomplete virological suppression, increased adverse effects, and suboptimal health outcomes. Of the 33 single-agent ARV medications and combination ARV products in five classes available at the time of review, approximately half exist as powders, liquids, injectables, or chewable or dissolvable tablets. If alternative ARV formulations or administration methods are used, close monitoring for achievement of virological and immunologic success and potential toxicities is recommended. Copyright © 2015 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

Transcription profiling of the chilling requirement for bud break in apples: a putative role for FLC-like genes.

PubMed

Porto, Diogo Denardi; Bruneau, Maryline; Perini, Pâmela; Anzanello, Rafael; Renou, Jean-Pierre; dos Santos, Henrique Pessoa; Fialho, Flávio Bello; Revers, Luís Fernando

2015-05-01

Apple production depends on the fulfilment of a chilling requirement for bud dormancy release. Insufficient winter chilling results in irregular and suboptimal bud break in the spring, with negative impacts on apple yield. Trees from apple cultivars with contrasting chilling requirements for bud break were used to investigate the expression of the entire set of apple genes in response to chilling accumulation in the field and controlled conditions. Total RNA was analysed on the AryANE v.1.0 oligonucleotide microarray chip representing 57,000 apple genes. The data were tested for functional enrichment, and differential expression was confirmed by real-time PCR. The largest number of differentially expressed genes was found in samples treated with cold temperatures. Cold exposure mostly repressed expression of transcripts related to photosynthesis, and long-term cold exposure repressed flavonoid biosynthesis genes. Among the differentially expressed selected candidates, we identified genes whose annotations were related to the circadian clock, hormonal signalling, regulation of growth, and flower development. Two genes, annotated as FLOWERING LOCUS C-like and MADS AFFECTING FLOWERING, showed strong differential expression in several comparisons. One of these two genes was upregulated in most comparisons involving dormancy release, and this gene's chromosomal position co-localized with the confidence interval of a major quantitative trait locus for the timing of bud break. These results indicate that photosynthesis and auxin transport are major regulatory nodes of apple dormancy and unveil strong candidates for the control of bud dormancy. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Wind modulation of upwelling at the shelf-break front off Patagonia: Observational evidence

NASA Astrophysics Data System (ADS)

Carranza, M. M.; Gille, S. T.; Piola, A. R.; Charo, M.; Romero, S. I.

2017-03-01

The South-Atlantic Patagonian shelf is the largest chlorophyll-a (Chl-a) hot spot in Southern Ocean color images. While a persistent 1500 km long band of high Chl-a along the shelf-break front (SBF) is indicative of upwelling, the mechanisms that drive it are not entirely known. Along-front wind oscillations can enhance upwelling and provide a nutrient pumping mechanism at shelf-break fronts of western boundary currents. Here we assess wind-induced upwelling at the SBF off Patagonia from daily satellite Chl-a and winds, historical hydrographic observations, cross-shelf Chl-a fluorescence transects from two cruises, and in situ winds and water column structure from a mooring site. Satellite Chl-a composites segregated by along-front wind direction indicate that surface Chl-a is enhanced at the SBF with southerly winds and suppressed with northerly winds. Northerly winds also result in enhanced Chl-a further offshore (˜25-50 km). Synoptic transects as well as mean hydrographic sections segregated by along-front winds show isopycnals tilted upward for southerly winds. Spring observations from the mooring also suggest that southerly winds destratify the water column and northerly winds restratify, in agreement with Ekman transport interacting with the front. Moreover, changes in water column temperature lag along-front wind forcing by 2-4 days. Our results suggest that oscillations in along-front winds, on timescales typical of atmospheric storms (2-10 days), can significantly modulate the upwelling and Chl-a concentrations at the SBF off Patagonia, revealing the importance of wind-induced upwelling for shelf-slope exchange at shelf-break fronts of western boundary currents.

Volume-based characterization of postocclusion surge.

PubMed

Zacharias, Jaime; Zacharias, Sergio

2005-10-01

To propose an alternative method to characterize postocclusion surge using a collapsible artificial anterior chamber to replace the currently used rigid anterior chamber model. Fundación Oftamológica Los Andes, Santiago, Chile. The distal end of a phacoemulsification handpiece was placed inside a compliant artificial anterior chamber. Digital recordings of chamber pressure, chamber volume, inflow, and outflow were performed during occlusion break of the phacoemulsification tip. The occlusion break profile of 2 different consoles was compared. Occlusion break while using a rigid anterior chamber model produced a simultaneous increase of chamber inflow and outflow. In the rigid chamber model, pressure decreased sharply, reaching negative pressure values. Alternatively, with the collapsible chamber model, a delay was observed in the inflow that occurs to compensate the outflow surge. Also, the chamber pressure drop was smaller in magnitude, never undershooting below atmospheric pressure into negative values. Using 500 mm Hg as vacuum limit, the Infiniti System (Alcon) performed better that the Legacy (Alcon), showing an 18% reduction in peak volume variation. The collapsible anterior chamber model provides a more realistic representation of the postocclusion surge events that occur in the real eye during cataract surgery. Peak volume fluctuation (mL), half volume recovery time(s), and volume fluctuation integral value (mL x s) are proposed as realistic indicators to characterize the postocclusion surge performance. These indicators show that the Infiniti System has a better postocclusion surge behavior than the Legacy System.

Observed changes in the vertical profile of stratopheric nitrous oxide at Thule, Greenland, February - March 1992

NASA Technical Reports Server (NTRS)

Emmons, Louisa K.; Reeves, John M.; Shindell, Drew T.; Dezafra, Robert L.

1994-01-01

Using a ground-based mm-wave spectrometer, we have observed stratospheric N2O over Thule, Greenland (76.3 N, 68.4 W) during late February and March, 1992. Vertical profiles of mixing ratio ranging from 16 to 50 km were recovered from molecular emission spectra. The profiles of early March show an abrupt increase in the lower-stratosphere N2O mixing ratio similar to the spring-to-summer change associated with the break up of the Antarctic polar vortex. This increase is correlated with changes in potential vorticity, air temperature, and ozone mixing ratio.

A spring window for geobotanical anomaly detection

NASA Technical Reports Server (NTRS)

Bell, R.; Labovitz, M. L.; Masuoka, E. J.

1985-01-01

The observation of senescence of deciduous vegetation to detect soil heavy metal mineralization is discussed. A gridded sampling of two sites of Quercus alba L. in south-central Virginia in 1982 is studied. The data reveal that smaller leaf blade lengths are observed in the soil site with copper, lead, and zinc concentrations. A random study in 1983 of red and white Q. rubra L., Q. prinus L., and Acer rubrum L., to confirm previous results is described. The observations of blade length and bud breaks show a 7-10 day lag in growth in the mineral site for the oak trees; however, the maple trees are not influenced by the minerals.

Hop powdery mildew control through alteration of spring pruning practices

USDA-ARS?s Scientific Manuscript database

Since 1997, Podosphaera macularis, the causal agent of hop powdery mildew, has become a recurrent threat to hops in the Pacific Northwest because of the potential to reduce cone yield and quality. Disease management practices often involve preventative fungicide applications, but alternative approac...

Evaluation of herbicides and application timing for control of japanese knotweed : final report, June 2003.

DOT National Transportation Integrated Search

2003-06-01

Testing was conducted from fall 2001 through spring 2003 to evaluate the efficacy of several herbicides, timing of : application (foliar vs. dormant), and an alternative application method (Burch Wet Blade) for control of Japanese knotweed along : hi...

Geologic context of large karst springs and caves in the Ozark National Scenic Riverways, Missouri

USGS Publications Warehouse

Weary, David J.; Orndorff, Randall C.

2016-01-01

The ONSR is a karst park, containing many springs and caves. The “jewels” of the park are large springs, several of first magnitude, that contribute significantly to the flow and water quality of the Current River and its tributaries. Completion of 1:24,000-scale geologic mapping of the park and surrounding river basin, along with synthesis of published hydrologic data, allows us to examine the spatial relationships between the springs and the geologic framework to develop a conceptual model for genesis of these springs. Based on their similarity to mapped spring conduits, many of the caves in the ONSR are fossil conduit segments. Therefore, geologic control on the evolution of the springs also applies to speleogenesis in this part of the southern Missouri Ozarks.Large springs occur in the ONSR area because: (1) the Ozark aquifer, from which they rise, is chiefly dolomite affected by solution via various processes over a long time period, (2) Paleozoic hypogenic fluid migration through these rocks exploited and enhanced flow-paths, (3) a consistent and low regional dip of the rocks off of the Salem Plateau (less than 2° to the southeast) allows integration of flow into large groundwater basins with a few discreet outlets, (4) the springs are located where the rivers have cut down into structural highs, allowing access to water from stratigraphic units deeper in the aquifer thus allowing development of springsheds that have volumetrically larger storage than smaller springs higher in the section, and (5) quartz sandstone and bedded chert in the carbonate stratigraphic succession that are locally to regionally continuous, serve as aquitards that locally confine groundwater up dip of the springs creating artesian conditions. This subhorizontal partitioning of the Ozark aquifer allows contributing areas for different springs to overlap, as evidenced by dye traces that cross adjacent groundwater basin boundaries, and possibly contributes to alternate flow routes under different groundwater flow regimes.A better understanding of the 3-dimensional hydrogeologic framework for the large spring systems in the ONSR allows more precise mapping of the contributing areas for those springs, will guide future studies of groundwater flow paths, and inform development of groundwater resource management strategies for the park.

Quantum anharmonic oscillator plus delta-function potential: a molecular view of pairing formation and breaking in the coordinate space

NASA Astrophysics Data System (ADS)

Sumaryada, Tony; Maha Putra, Bima; Pramudito, Sidikrubadi

2017-05-01

We propose an alternative way to describe the pairing formation and breaking via a quantum anharmonic oscillator with a delta-function potential model. Unlike BCS theory, which describes the pairing formation in the momentum space, this model works in the coordinate space and is able to give a molecular view of pairing formation and breaking in the coordinate space. By exploring the dynamical interplay between the intrinsic factor (dissociation energy) and external factor (pairing strength) of this system additional information was gained, including the critical pairing strength and critical scattering length, which might relate to the BCS-BEC crossover phenomena and halo state formation. Although only the energetic aspect of pairing is described by this model, its simplicity and pedagogical steps might help undergraduate students to understand the pairing problem in a simple way.

DNA damage induction and/or repair as mammalian cell biomarker for the prediction of cellular radiation response

NASA Astrophysics Data System (ADS)

Baumstark-Khan, C.

DNA damage and its repair processes are key factors in cancer induction and also in the treatment of malignancies. Cancer prevention during extended space missions becomes a topic of great importance for space radiobiology. The knowledge of individual responsiveness would allow the protection strategy to be tailored optimally in each case. Radiobiological analysis of cultured cells derived from tissue explants from individuals has shown that measurement of the surviving fraction after 2 Gy (SF2) may be used to predict the individual responsiveness. However, clonogenic assays are timeconsuming, thus alternative assays for the determination of radiore-sponse are being sought. For that reason CHO cell strains having different repair capacities were used for examining whether DNA strand break repair is a suitable experimental design to allow predictive statements. Cellular survival (CFA assay) and DNA strand breaks (total DNA strand breaks: FADU technique; DSBs: non-denaturing elution) were determined in parallel immediately after irradiation as well as after a 24 hour recovery period according to dose. There were no correlations between the dose-response curves of the initial level of DNA strand breaks and parameters that describe clonogenic survival curves (SF2). A good correlation exists between intrinsic cellular radioresistance and the extent of residual DNA strand breaks.

Joint pattern of seasonal hydrological droughts and floods alternation in China's Huai River Basin using the multivariate L-moments

NASA Astrophysics Data System (ADS)

Wu, ShaoFei; Zhang, Xiang; She, DunXian

2017-06-01

Under the current condition of climate change, droughts and floods occur more frequently, and events in which flooding occurs after a prolonged drought or a drought occurs after an extreme flood may have a more severe impact on natural systems and human lives. This challenges the traditional approach wherein droughts and floods are considered separately, which may largely underestimate the risk of the disasters. In our study, the sudden alternation of droughts and flood events (ADFEs) between adjacent seasons is studied using the multivariate L-moments theory and the bivariate copula functions in the Huai River Basin (HRB) of China with monthly streamflow data at 32 hydrological stations from 1956 to 2012. The dry and wet conditions are characterized by the standardized streamflow index (SSI) at a 3-month time scale. The results show that: (1) The summer streamflow makes the largest contribution to the annual streamflow, followed by the autumn streamflow and spring streamflow. (2) The entire study area can be divided into five homogeneous sub-regions using the multivariate regional homogeneity test. The generalized logistic distribution (GLO) and log-normal distribution (LN3) are acceptable to be the optimal marginal distributions under most conditions, and the Frank copula is more appropriate for spring-summer and summer-autumn SSI series. Continuous flood events dominate at most sites both in spring-summer and summer-autumn (with an average frequency of 13.78% and 17.06%, respectively), while continuous drought events come second (with an average frequency of 11.27% and 13.79%, respectively). Moreover, seasonal ADFEs most probably occurred near the mainstream of HRB, and drought and flood events are more likely to occur in summer-autumn than in spring-summer.

The role of the subtropical North Atlantic water cycle in recent US extreme precipitation events

NASA Astrophysics Data System (ADS)

Li, Laifang; Schmitt, Raymond W.; Ummenhofer, Caroline C.

2018-02-01

The role of the oceanic water cycle in the record-breaking 2015 warm-season precipitation in the US is analyzed. The extreme precipitation started in the Southern US in the spring and propagated northward to the Midwest and the Great Lakes in the summer of 2015. This seasonal evolution of precipitation anomalies represents a typical mode of variability of US warm-season precipitation. Analysis of the atmospheric moisture flux suggests that such a rainfall mode is associated with moisture export from the subtropical North Atlantic. In the spring, excessive precipitation in the Southern US is attributable to increased moisture flux from the northwestern portion of the subtropical North Atlantic. The North Atlantic moisture flux interacts with local soil moisture which enables the US Midwest to draw more moisture from the Gulf of Mexico in the summer. Further analysis shows that the relationship between the rainfall mode and the North Atlantic water cycle has become more significant in recent decades, indicating an increased likelihood of extremes like the 2015 case. Indeed, two record-high warm-season precipitation events, the 1993 and 2008 cases, both occurred in the more recent decades of the 66 year analysis period. The export of water from the North Atlantic leaves a marked surface salinity signature. The salinity signature appeared in the spring preceding all three extreme precipitation events analyzed in this study, i.e. a saltier-than-normal subtropical North Atlantic in spring followed by extreme Midwest precipitation in summer. Compared to the various sea surface temperature anomaly patterns among the 1993, 2008, and 2015 cases, the spatial distribution of salinity anomalies was much more consistent during these extreme flood years. Thus, our study suggests that preseason salinity patterns can be used for improved seasonal prediction of extreme precipitation in the Midwest.

Late Spring Nitrate Distributions Beneath the Ice-Covered Northeastern Chukchi Shelf

NASA Astrophysics Data System (ADS)

Arrigo, Kevin R.; Mills, Matthew M.; van Dijken, Gert L.; Lowry, Kate E.; Pickart, Robert S.; Schlitzer, Reiner

2017-09-01

Measurements of late springtime nutrient concentrations in Arctic waters are relatively rare due to the extensive sea ice cover that makes sampling difficult. During the SUBICE (Study of Under-ice Blooms In the Chukchi Ecosystem) cruise in May-June 2014, an extensive survey of hydrography and prebloom concentrations of inorganic macronutrients, oxygen, particulate organic carbon and nitrogen, and chlorophyll a was conducted in the northeastern Chukchi Sea. Cold (<-1.5°C) winter water was prevalent throughout the study area, and the water column was weakly stratified. Nitrate (NO3-) concentration averaged 12.6 ± 1.92 μM in surface waters and 14.0 ± 1.91 μM near the bottom and was significantly correlated with salinity. The highest NO3- concentrations were associated with winter water within the Central Channel flow path. NO3- concentrations were much reduced near the northern shelf break within the upper halocline waters of the Canada Basin and along the eastern side of the shelf near the Alaskan coast. Net community production (NCP), estimated as the difference in depth-integrated NO3- content between spring (this study) and summer (historical), varied from 28 to 38 g C m-2 a-1. This is much lower than previous NCP estimates that used NO3- concentrations from the southeastern Bering Sea as a baseline. These results demonstrate the importance of using profiles of NO3- measured as close to the beginning of the spring bloom as possible when estimating local NCP. They also show that once the snow melts in spring, increased light transmission through the sea ice to the waters below the ice could fuel large phytoplankton blooms over a much wider area than previously known.

Estimating Colloidal Contact Model Parameters Using Quasi-Static Compression Simulations.

PubMed

Bürger, Vincent; Briesen, Heiko

2016-10-05

For colloidal particles interacting in suspensions, clusters, or gels, contact models should attempt to include all physical phenomena experimentally observed. One critical point when formulating a contact model is to ensure that the interaction parameters can be easily obtained from experiments. Experimental determinations of contact parameters for particles either are based on bulk measurements for simulations on the macroscopic scale or require elaborate setups for obtaining tangential parameters such as using atomic force microscopy. However, on the colloidal scale, a simple method is required to obtain all interaction parameters simultaneously. This work demonstrates that quasi-static compression of a fractal-like particle network provides all the necessary information to obtain particle interaction parameters using a simple spring-based contact model. These springs provide resistances against all degrees of freedom associated with two-particle interactions, and include critical forces or moments where such springs break, indicating a bond-breakage event. A position-based cost function is introduced to show the identifiability of the two-particle contact parameters, and a discrete, nonlinear, and non-gradient-based global optimization method (simplex with simulated annealing, SIMPSA) is used to minimize the cost function calculated from deviations of particle positions. Results show that, in principle, all necessary contact parameters for an arbitrary particle network can be identified, although numerical efficiency as well as experimental noise must be addressed when applying this method. Such an approach lays the groundwork for identifying particle-contact parameters from a position-based particle analysis for a colloidal system using just one experiment. Spring constants also directly influence the time step of the discrete-element method, and a detailed knowledge of all necessary interaction parameters will help to improve the efficiency of colloidal particle simulations.

Biogeography of thermophilic phototrophic bacteria belonging to Roseiflexus genus.

PubMed

Gaisin, Vasil A; Grouzdev, Denis S; Namsaraev, Zorigto B; Sukhacheva, Marina V; Gorlenko, Vladimir M; Kuznetsov, Boris B

2016-03-01

Isolated environments such as hot springs are particularly interesting for studying the microbial biogeography. These environments create an 'island effect' leading to genetic divergence. We studied the phylogeographic pattern of thermophilic anoxygenic phototrophic bacteria, belonging to the Roseiflexus genus. The main characteristic of the observed pattern was geographic and geochronologic fidelity to the hot springs within Circum-Pacific and Alpine-Himalayan-Indonesian orogenic belts. Mantel test revealed a correlation between genetic divergence and geographic distance among the phylotypes. Cluster analysis revealed a regional differentiation of the global phylogenetic pattern. The phylogeographic pattern is in correlation with geochronologic events during the break up of Pangaea that led to the modern configuration of continents. To our knowledge this is the first geochronological scenario of intercontinental prokaryotic taxon divergence. The existence of the modern phylogeographic pattern contradicts with the existence of the ancient evolutionary history of the Roseiflexus group proposed on the basis of its deep-branching phylogenetic position. These facts indicate that evolutionary rates in Roseiflexus varied over a wide range. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

A Modeling Study of the Spring 2011 Extreme US Weather Activity

NASA Technical Reports Server (NTRS)

Schubert, S.; Suarez, M.; Chang, Y.

2012-01-01

The spring of 2011 was characterized by record-breaking tornadic activity with substantial loss of life and destruction of property. While a waning La Nina and other atmospheric teleconnections have been implicated in the development of these extreme weather events, a quantitative assessment of their causes is still lacking. This study uses high resolution (1/4 lat/lon) GEOS-5 AGCM experiments to quantify the role of SSTs and soil moisture in the development of the extreme weather activity with a focus on April - the month of peak tornadic activity. The simulations, consisting of 22-member ensembles of three-month long simulations (initialized March 1st) reproduce the main features of the observed large-scale changes including the below-normal temperature and above-normal precipitation in the Central US, and the hot and dry conditions to the south. Various sensitivity experiments are conducted to separate the roles of the SST, soil moisture and the initial atmospheric conditions in the development and predictability of the atmospheric conditions (wind shear, moisture, etc.) favoring the severe weather activity and flooding.

An Examination of Test-Retest, Alternate Form Reliability, and Generalizability Theory Study of the easyCBM Word and Passage Reading Fluency Assessments: Grade 3. Technical Report #1218

ERIC Educational Resources Information Center

Park, Bitnara Jasmine; Anderson, Daniel; Alonzo, Julie; Lai, Cheng-Fei; Tindal, Gerald

2012-01-01

This technical report is one in a series of five describing the reliability (test/retest and alternate form) and G-Theory/D-Study research on the easyCBM reading measures, grades 1-5. Data were gathered in the spring of 2011 from a convenience sample of students nested within classrooms at a medium-sized school district in the Pacific Northwest.…

The Green's matrix and the boundary integral equations for analysis of time-harmonic dynamics of elastic helical springs.

PubMed

Sorokin, Sergey V

2011-03-01

Helical springs serve as vibration isolators in virtually any suspension system. Various exact and approximate methods may be employed to determine the eigenfrequencies of vibrations of these structural elements and their dynamic transfer functions. The method of boundary integral equations is a meaningful alternative to obtain exact solutions of problems of the time-harmonic dynamics of elastic springs in the framework of Bernoulli-Euler beam theory. In this paper, the derivations of the Green's matrix, of the Somigliana's identities, and of the boundary integral equations are presented. The vibrational power transmission in an infinitely long spring is analyzed by means of the Green's matrix. The eigenfrequencies and the dynamic transfer functions are found by solving the boundary integral equations. In the course of analysis, the essential features and advantages of the method of boundary integral equations are highlighted. The reported analytical results may be used to study the time-harmonic motion in any wave guide governed by a system of linear differential equations in a single spatial coordinate along its axis. © 2011 Acoustical Society of America

Variable stiffness mechanisms with SMA actuators

NASA Astrophysics Data System (ADS)

Siler, Damin J.; Demoret, Kimberly B. J.

1996-05-01

Variable stiffness is a new branch of smart structures development with several applications related to aircraft. Previous research indicates that temporarily reducing the stiffness of an airplane wing can decrease control actuator sizing and improve aeroelastic roll performance. Some smart materials like shape memory alloys (SMA) can change their material stiffness properties, but they tend to gain stiffness in their `power on' state. An alternative is to integrate mechanisms into a structure and change stiffness by altering boundary conditions and structural load paths. An innovative concept for an axial strut mechanism was discovered as part of research into variable stiffness. It employs SMA springs (specifically Ni-Ti) in a way that reduces overall stiffness when the SMA springs gain stiffness. A simplified mathematical model for static analysis was developed, and a 70% reduction in stiffness was obtained for a particular selection of springs. The small force capacity of commercially available SMA springs limits the practicality of this concept for large load applications. However, smart material technology is still immature, and future advances may permit development of a heavy-duty, variable stiffness strut that is small and light enough for use in aircraft structures.

Memoized Online Variational Inference for Dirichlet Process Mixture Models

DTIC Science & Technology

2014-06-27

breaking process [7], which places artifically large mass on the final component. It is more efficient and broadly applicable than an alternative trunction...models. In Uncertainty in Artificial Intelligence , 2008. [13] N. Le Roux, M. Schmidt, and F. Bach. A stochastic gradient method with an exponential

Alternatives to an elementary Higgs

NASA Astrophysics Data System (ADS)

Csáki, Csaba; Grojean, Christophe; Terning, John

2016-10-01

Strongly coupled and extra-dimensional models of electroweak symmetry breaking are reviewed. Models examined include warped extra dimensions, bulk Higgs, "little" Higgs, dilaton Higgs, composite Higgs, twin Higgs, quantum critical Higgs, and "fat" SUSY Higgs. Also discussed are current bounds and future LHC searches for this class of models.

Moving beyond traditional fire management practices to better minimize community vulnerability to wildfire in southern California

NASA Astrophysics Data System (ADS)

Syphard, A. D.; Keeley, J. E.; Brennan, T. J.

2010-12-01

Wildfires are an important natural process in southern California, but they also present a major hazard for human life and property. The region leads the nation in fire-related losses, and since 2001, wildfires have damaged or destroyed more than 10,000 homes. As human ignitions have increased along with urban development and population growth, fire frequency has also surged, and most home losses occur in large fires when ignitions coincide with Santa Ana windstorms. As the region accommodates more growth in the future, the wildfire threat promises to continue. We will thus explore how a broader, more comprehensive approach to fire management could improve upon traditional approaches for reducing community vulnerability. The traditional approach to mitigating fire risk, in addition to fire suppression, has been to reduce fuel through construction of fuel breaks. Despite increasing expenditure on these treatments, there has been little empirical study of their role in controlling large fires. We will present the results of a study in which we constructed and analyzed a spatial database of fuel breaks in southern California national forests. Our objective was to better understand characteristics of fuel breaks that affect the behavior of large fires and to map where fires and fuel breaks most commonly intersect. We found that fires stopped at fuel breaks 22-47% of the time, depending on the forest, and the reason fires stopped was invariably related to firefighter access and management activities. Fire weather and fuel break condition were also important. The study illustrates the importance of strategic location of fuel breaks because they have been most effective where they provided access for firefighting activities. While fuel breaks have played a role in controlling wildfires at the Wildland Urban Interface, we are evaluating alternative approaches for reducing community vulnerability, including land use planning. Recent research shows that the amount and spatial arrangement of human infrastructure, such as roads and housing developments, strongly influences wildfire patterns. Therefore, we hypothesize that the spatial arrangement and location of housing development is likely to affect the susceptibility of lives and property to fire. In other words, potential for urban loss may be greatest at specific housing densities, spatial patterns of development, and locations of development. If these risk factors can be identified, mapped, and modeled, it is possible that vulnerability to wildfire could be substantially minimized through careful planning for future development - especially because future development will likely increase the region’s fire risk. To address these possibilities, we are evaluating past housing loss in relation to land use planning, in conjunction with other variables that influence fire patterns. We are also exploring alternative future scenarios to identify optimum land use planning strategies for minimizing fire risk.

Spring-fall asymmetry of substorm strength, geomagnetic activity and solar wind: Implications for semiannual variation and solar hemispheric asymmetry

USGS Publications Warehouse

Marsula, K.; Tanskanen, E.; Love, J.J.

2011-01-01

We study the seasonal variation of substorms, geomagnetic activity and their solar wind drivers in 1993–2008. The number of substorms and substorm mean duration depict an annual variation with maxima in Winter and Summer, respectively, reflecting the annual change of the local ionosphere. In contradiction, substorm mean amplitude, substorm total efficiency and global geomagnetic activity show a dominant annual variation, with equinoctial maxima alternating between Spring in solar cycle 22 and Fall in cycle 23. The largest annual variations were found in 1994 and 2003, in the declining phase of the two cycles when high-speed streams dominate the solar wind. A similar, large annual variation is found in the solar wind driver of substorms and geomagnetic activity, which implies that the annual variation of substorm strength, substorm efficiency and geomagnetic activity is not due to ionospheric conditions but to a hemispherically asymmetric distribution of solar wind which varies from one cycle to another. Our results imply that the overall semiannual variation in global geomagnetic activity has been seriously overestimated, and is largely an artifact of the dominant annual variation with maxima alternating between Spring and Fall. The results also suggest an intimate connection between the asymmetry of solar magnetic fields and some of the largest geomagnetic disturbances, offering interesting new pathways for forecasting disturbances with a longer lead time to the future.

Chains of benzenes with lithium-atom adsorption: Vibrations and spontaneous symmetry breaking

NASA Astrophysics Data System (ADS)

Ortiz, Yenni P.; Stegmann, Thomas; Klein, Douglas J.; Seligman, Thomas H.

2017-09-01

We study effects of different configurations of adsorbates on the vibrational modes as well as symmetries of polyacenes and poly-p-phenylenes focusing on lithium atom adsorption. We found that the spectra of the vibrational modes distinguish the different configurations. For more regular adsorption schemes the lowest states are bending and torsion modes of the skeleton, which are essentially followed by the adsorbate. On poly-p-phenylenes we found that lithium adsorption reduces and often eliminates the torsion between rings thus increasing symmetry. There is spontaneous symmetry breaking in poly-p-phenylenes due to double adsorption of lithium atoms on alternating rings.

Let's Get Virtual

ERIC Educational Resources Information Center

Wills, Eric

2006-01-01

With gym time getting squeezed out by standardized tests and extracurriculars, schools are beginning to digitize physical education. This alternative method is first being offered by Minneapolis public schools in spring of 2005. In digital physical education, students can perform physical activities like they would in a traditional PE class but…

Environmental Assessment Upgrade of the Indian Springs Collection and Treatment System

DTIC Science & Technology

2009-12-10

site is voluntary . Alternatively, if the proposed project is federally funded in whole or a significant portion, we understand that the project may be...a veterinarian proficient in reptile medicine for evaluation of appropriate treatment. Rehabilitation or euthanasia expenses will not be covered by

Willingness to Pay for Willamette Basin Spring Chinook and Winter Steelhead Recovery

EPA Science Inventory

Two of the primary goals of conducting economic valuation studies should be to improve the way in which communities frame choices regarding the allocation of scarce resources and to clarify the trade-offs between alternative outcomes. The challenge of quantifying public preferen...

Indian Students' Problems in Boarding Schools.

ERIC Educational Resources Information Center

Klinekole, Ruth V.

1979-01-01

Indian students who have withdrawn from public schools for various reasons may receive alternative education at Bureau of Indian Affairs (BIA) Boarding Schools, but they may also face academic, environmental, and personal problems. Attending a boarding school involves a radical culture break. Students are often far from home, deprived of parental…

Superconductivity as a Synchronous Spatial Alternation of Valence Bonds.

DTIC Science & Technology

1987-04-01

approach. 9 This is likely to be the case in three-dimensions as well. As pair breaking excitations ( magnons ) can be formed at essentially no energy...cost (remember the form of the magnon dispersion curve of 1-D Heisenberg model), superconductivity cannot be achieved. In principle, these metals can be

VOC-FREE, HIGHLY FLAME-RESISTANT HYBRIDSIL® INSULATION COATINGS FOR NEXT-GENERATION THERMAL INSULATION AND ENERGY EFFICIENCY - PHASE II

EPA Science Inventory

NanoSonic's HybridSil^® insulative coatings provide a paradigm-breaking alternative to spray-deposited polyurethane foams by affording comparable insulation, yet without any of the health and safety concerns associated ...

Evaluation of Breakthrough's "America 2049" Game

ERIC Educational Resources Information Center

Diamond, James; Brunner, Cornelia

2011-01-01

Breakthrough, a global human rights organization, produced "America 2049," an alternate-reality game set in a dystopian future in which the United States is on the verge of breaking apart because of an inability to tolerate diversity and promote human rights. During the 12-week game launch, players uncovered artifacts related to the…

Fourier Analysis and the Rhythm of Conversation.

ERIC Educational Resources Information Center

Dabbs, James M., Jr.

Fourier analysis, a common technique in engineering, breaks down a complex wave form into its simple sine wave components. Communication researchers have recently suggested that this technique may provide an index of the rhythm of conversation, since vocalizing and pausing produce a complex wave form pattern of alternation between two speakers. To…

The School-to-Prison Pipeline: From School Punishment to Rehabilitative Inclusion

ERIC Educational Resources Information Center

Mallett, Christopher A.

2016-01-01

The zero tolerance policy movement across most of this country's school districts significantly limited school personnel's disciplinary alternatives for students who break rules on campus. This has resulted in millions of primary and secondary age students who have experienced suspension, arrests, and for some, expulsion. Within the student…

A Future Star: Challenging Stereotypes of Diversity

ERIC Educational Resources Information Center

Hernandez, Paul; Loebickin, Karla

2015-01-01

Ice-breaking discussions around race and personal perspectives can be challenging in any classroom, they also are crucial to cultivating racial consciousness among those espousing that they know better. This provides the groundwork needed to implement--in a non-threatening manner--the creative, alternative methods that will combine students'…

Difficult Dialogues about Service Learning: Embrace the Messiness

ERIC Educational Resources Information Center

Hui, S. Mei-Yen

2009-01-01

When she was graduate coordinator for the Office of Community Service-Learning's Alternative Breaks (AB) program at the University of Maryland-College Park, the author had the privilege of working with undergraduate student trip leaders as they researched, planned, and coordinated weeklong service-learning immersion trips in which students would…

Rescuing Computerized Testing by Breaking Zipf's Law.

ERIC Educational Resources Information Center

Wainer, Howard

2000-01-01

Suggests that because of the nonlinear relationship between item usage and item security, the problems of test security posed by continuous administration of standardized tests cannot be resolved merely by increasing the size of the item pool. Offers alternative strategies to overcome these problems, distributing test items so as to avoid the…

Model Building to Facilitate Understanding of Holliday Junction and Heteroduplex Formation, and Holliday Junction Resolution

ERIC Educational Resources Information Center

Selvarajah, Geeta; Selvarajah, Susila

2016-01-01

Students frequently expressed difficulty in understanding the molecular mechanisms involved in chromosomal recombination. Therefore, we explored alternative methods for presenting the two concepts of the double-strand break model: Holliday junction and heteroduplex formation, and Holliday junction resolution. In addition to a lecture and…

Ecological Data in Support of the Tank Closure and Waste Management Environmental Impact Statement. Part 2: Results of Spring 2007 Field Surveys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sackschewsky, Michael R.; Downs, Janelle L.

2007-05-31

This review provides an evaluation of potential impacts of actions that have been proposed under various alternatives to support the closure of the high level waste tanks on the Hanford Site. This review provides a summary of data collected in the field during the spring of 2007 at all of the proposed project sites within 200 East and 200 West Areas, and at sites not previously surveyed. The primary purpose of this review is to provide biological data that can be incorporated into or used to support the Tank Closure and Waste Management Environmental Impact Statement.

Draft Environmental Impact Statement. MX Deployment Area Selection and Land Withdrawal/Acquisition DEIS. Volume IV. Part II. Environmental Consequences to the Study Regions and Operating Base Vicinities.

DTIC Science & Technology

1980-12-01

desert tortoise distribution at Coyote Spring OB and vicinity. 4-179 4.3.1.9-3 Utah Prairie Dog distribution and Proposed Action conceptual project...layout. 4-185 4.3.1.9-4 Distribution of Utah prairie dog in the vicinity of the Milford OB. 4-187 4.3.1.9-5 Distribution of Utah prairie dog in the...Coyote Spring. 4-180 4.3.1.9-2 Potential impact to the Utah prairie dog around operating bases (OBs) for the Proposed Action and Alternatives 1-8. 4-188

Beyond Paper and Pencil.

ERIC Educational Resources Information Center

Badger, Elizabeth; And Others

In the spring of 1989, over 2,000 pairs of fourth- and eighth-grade students were assessed on their ability to apply mathematical and scientific concepts. The tests (administered in alternate years during the written assessments of the Massachusetts Educational Assessment Program) required students to apply what they knew about mathematics and…

Internship as an Alternative to Student Teaching.

ERIC Educational Resources Information Center

Richards, Don

An internship program involving university students placed in public school classrooms for a full year was initiated through the cooperative efforts of Wright State University and the Yellow Springs, Ohio school district, an innovative district which embraces the concept of individually guided education and which utilizes team teaching at all…

Tackling the Problem of Repurposing Web Content

ERIC Educational Resources Information Center

Gerber, Nathan; Merker, Lance

2008-01-01

Like many institutions across the country, Utah Valley State College (UVSC) found itself struggling to keep its website current. In the spring of 2003, the UVSC's IT department began looking at alternatives that would simplify and streamline the process of updating the university's web pages. Specifically, they wanted a straightforward way to…

A Survey of Student Experiences, Spring, 1973.

ERIC Educational Resources Information Center

Litwin, James L.

The Modular Achievement Program (MAP) at Bowling Green State University was designed to offer students an alternative experience for the freshman year. The experience would include small classes, a student-oriented staff, career workshops and an innovative curriculum. This document describes and reports the findings of a survey of student…

"Restorative Practices" Offer Alternatives to Suspension

ERIC Educational Resources Information Center

Shah, Nirvi

2012-01-01

At City Springs and many other schools across the country, restorative practices are about holding students accountable and getting them to right a wrong. The approach is getting more notice than ever as criticism grows of zero-tolerance disciplinary policies that often require out-of-school suspension and expulsion. Educators are turning to…

Agrobacterium-Mediated Transformation of Bread and Durum Wheat Using Freshly Isolated Immature Embryos

NASA Astrophysics Data System (ADS)

Huixia, Wu; Angela, Doherty; Jones, Huw D.

Agrobacterium-mediated transformation of wheat is becoming a viable alternative to the more established biolistic protocols. It offers advantages in terms of simple, low-copy-number integrations and can be applied with similar efficiencies to specific durum wheat and spring and winter bread wheat types varieties.

Spring Temperatures Alone Cannot Explain Timing of Budburst of Boreal-Temperate Tree Species under Experimental Warming

NASA Astrophysics Data System (ADS)

Montgomery, R. A.; Reich, P. B.; Rich, R. L.; Stefanski, A.

2011-12-01

Phenology, the timing of seasonal biological events such as budburst, blossom dates, bird migration and insect development, is critical to understanding species interactions (e.g. pollination, herbivory); determines growing season length in many (i.e. seasonal) terrestrial ecosystems; and can play a role in determining species range limits. There is ample evidence that plant and animal phenology has changed in recent decades. For trees in seasonally cold climates, change is most commonly manifested as earlier budburst, likely caused by earlier onset of warming temperatures in spring. Indeed, it is often assumed that one of the major phenological responses of temperate and boreal forest ecosystems to climate change will be earlier leafing and concomitantly, a longer growing season. However, spring warming interacts with other factors such as winter chilling and photoperiod to determine timing of spring leafing. For example, warmer winters could reduce the duration and amount of chilling experienced by dormant buds and lead to delayed budburst. Despite knowledge that such interactions exist, we know little about the interactive mechanisms by which various cues influence budburst in forest tree species or whether species differ in sensitivity to those cues. This gap hinders our ability to predict phenological responses and their ecological impacts under future climate scenarios. Over the past three years, we have conducted studies of leafing phenology, germination, photosynthesis, respiration, and growth of seedlings of ten boreal-temperate tree species subjected to experimental warming using infrared heat lamps and soil heating cables. Seedlings were planted into plots receiving ambient, +1.8°C or +3.6°C temperature treatments in open, aspen forest at the Cloquet Forestry Center, Cloquet, MN, USA (46°31' N, 92°30' W, 386 m a.s.l.; 4.5°C MAT, 807 mm MAP). While all species responded to warming by advancing the absolute date of budburst, several lines of evidence support the role of other factors, namely photoperiod or chilling, in co-determining observed responses. First, a number of species showed non-linear responses in absolute day of year of budburst across levels of warming: specifically, some species did not advance the date of budburst in +3.6°C compared to +1.8°C treatments. Second, if warming was the only cue for budburst, then one would expect that the plants would break bud after the same amount of warming regardless of treatment (i.e. at the same thermal time) and thus they would reach that threshold earlier in the warmed treatments (i.e. earlier absolute time). This was not observed. Instead, using thermal time to budburst rather than absolute date of budburst, we found that all species required more warming to break bud in warmed compared to unwarmed treatments. Lastly, when we examined the relationship between thermal time to budburst and chill days, we found that longer thermal time to budburst was associated with reduced chilling. Taken together, these three lines of evidence suggest that spring warming is not the only cue for budburst. Future research and modelling must recognize the role of other cues.

Connections Between the Spring Breakup of the Southern Hemisphere Polar Vortex, Stationary Waves, and Air-sea Roughness

NASA Technical Reports Server (NTRS)

Garfinkel, Chaim I.; Oman, Luke David; Barnes, Elizabeth A.; Waugh, Darryn W.; Hurwitz, Margaret H.; Molod, Andrea M.

2013-01-01

A robust connection between the drag on surface-layer winds and the stratospheric circulation is demonstrated in NASA's Goddard Earth Observing System Chemistry-Climate Model (GEOSCCM). Specifically, an updated parameterization of roughness at the air-sea interface, in which surface roughness is increased for moderate wind speeds (4ms to 20ms), leads to a decrease in model biases in Southern Hemispheric ozone, polar cap temperature, stationary wave heat flux, and springtime vortex breakup. A dynamical mechanism is proposed whereby increased surface roughness leads to improved stationary waves. Increased surface roughness leads to anomalous eddy momentum flux convergence primarily in the Indian Ocean sector (where eddies are strongest climatologically) in September and October. The localization of the eddy momentum flux convergence anomaly in the Indian Ocean sector leads to a zonally asymmetric reduction in zonal wind and, by geostrophy, to a wavenumber-1 stationary wave pattern. This tropospheric stationary wave pattern leads to enhanced upwards wave activity entering the stratosphere. The net effect is an improved Southern Hemisphere vortex: the vortex breaks up earlier in spring (i.e., the spring late-breakup bias is partially ameliorated) yet is no weaker in mid-winter. More than half of the stratospheric biases appear to be related to the surface wind speed biases. As many other chemistry climate models use a similar scheme for their surface layer momentum exchange and have similar biases in the stratosphere, we expect that results from GEOSCCM may be relevant for other climate models.

Variation of heart transplant rates in the United States during holidays.

PubMed

Grodin, Justin L; Ayers, Colby R; Thibodeau, Jennifer T; Mishkin, Joseph D; Mammen, Pradeep P A; Markham, David W; Drazner, Mark H; Patel, Parag C

2014-08-01

Some cardiac transplant programs may upgrade listed patients to United Network for Organ Sharing (UNOS) 1A-status during the holidays. Whether more transplants actually occur during holidays is unknown. We assessed rates of single-organ heart transplantation from 2001 to 2010 for recipients age ≥18 yr using the UNOS database. Patients were stratified by transplantation during holiday (±3 d, n = 2375) and non-holiday periods (n = 16 112). Holidays included Easter/Spring break, Memorial Day, July 4th, Labor Day, Thanksgiving, and Christmas/New Years (winter holidays). Secondary analysis assessing transplant rates across seasons was also completed. Donor and recipient characteristics were similar between groups. Compared with non-holidays, July 4th had higher transplant rates (5.69 vs. 5.09 transplants/d, p = 0.03) while the winter holiday had lower transplant rates (4.50 vs. 5.09 transplants/d, p < 0.01). There was a trend toward lower transplant rates for all holidays compared with non-holidays (p = 0.06). Transplant rates were significantly different across seasons with greater rates in spring and summer (p < 0.01). Heart transplant rates were higher during the July 4th and lower during the winter holidays. Although there was a higher likelihood of transplantation during the spring and summer seasons, upgrading patients to 1A status during most holidays may not improve their chances for transplantation. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Phytoplankton characteristics and hydrological conditions in the western part of the Sea of Okhotsk in the spring of 1999 and 2000 based on expeditionary and satellite data

NASA Astrophysics Data System (ADS)

Zakharkov, S. P.; Selina, M. S.; Vanin, N. S.; Shtraikhert, E. A.; Biebov, N.

2007-08-01

Using the data obtained in 1999 2000 during the spring bloom of phytoplankton (late May early June), the variability of the pigment concentrations, the phytoplankton biomass and species compositions, and the hydrological conditions on the eastern shelf of Sakhalin Island was studied. The study resulted in revealing 135 microalgae species belonging to eight divisions. The most diversely presented were the Dinophyta dinoflagellates and Bacillariophyta diatoms (70 and 53 species, respectively). The concentration of chlorophyll a in the euphotic zone amounted, on average, to 3.8 mg/m3 in 1999 and 2.4 mg/m3 in 2000. It was shown that, in the northern and southern parts of the coastal zone, the concentration of chlorophyll a and the phytoplankton density in the spring were considerably different and depended on the hydrological conditions. In the north, their maximum values were found in the area of the depth break and were determined by the tidal mixing. The increased algae concentrations and temperature inversions at depths of 400 600 m confirm the downslope sliding of the near-bottom shelf waters. In the southern part, the high phytoplankton concentrations in the surface layer in 1999 confirmed by the monthly averaged estimates from the SeaWiFS satellite color scanner were caused by the abnormal northward propagation of the Soya Current waters and by intense tidal mixing.

Problems with the application of hydrogeological science to regulation of Australian mining projects: Carmichael Mine and Doongmabulla Springs

NASA Astrophysics Data System (ADS)

Currell, Matthew J.; Werner, Adrian D.; McGrath, Chris; Webb, John A.; Berkman, Michael

2017-05-01

Understanding and managing impacts from mining on groundwater-dependent ecosystems (GDEs) and other groundwater users requires development of defensible science supported by adequate field data. This usually leads to the creation of predictive models and analysis of the likely impacts of mining and their accompanying uncertainties. The identification, monitoring and management of impacts on GDEs are often a key component of mine approvals, which need to consider and attempt to minimise the risks that negative impacts may arise. Here we examine a case study where approval for a large mining project in Australia (Carmichael Coal Mine) was challenged in court on the basis that it may result in more extensive impacts on a GDE (Doongmabulla Springs) of high ecological and cultural significance than predicted by the proponent. We show that throughout the environmental assessment and approval process, significant data gaps and scientific uncertainties remained unresolved. Evidence shows that the assumed conceptual hydrogeological model for the springs could be incorrect, and that at least one alternative conceptualisation (that the springs are dependent on a deep fault) is consistent with the available field data. Assumptions made about changes to spring flow as a consequence of mine-induced drawdown also appear problematic, with significant implications for the spring-fed wetlands. Despite the large scale of the project, it appears that critical scientific data required to resolve uncertainties and construct robust models of the springs' relationship to the groundwater system were lacking at the time of approval, contributing to uncertainty and conflict. For this reason, we recommend changes to the approval process that would require a higher standard of scientific information to be collected and reviewed, particularly in relation to key environmental assets during the environmental impact assessment process in future projects.

Do Yield and Quality of Big Bluestem and Switchgrass Feedstock Decline over Winter?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Jane M. F.; Gresham, Garold L.

Switchgrass (Panicum virgatum L.) and big bluestem (Andropogon gerdardii Vitman) are potential perennial bioenergy feedstocks. Feedstock storage limitations, labor constraints for harvest, and environmental benefits provided by perennials are rationales for developing localized perennial feedstock as an alternative or in conjunction with annual feedstocks (i.e., crop residues). Little information is available on yield, mineral, and thermochemical properties of native species as related to harvest time. The study’s objectives were to compare the feedstock quantity and quality between grasses harvested in the fall or the following spring. It was hypothesized that biomass yield may decline, but translocation and/or leaching of mineralsmore » from the feedstock would improve feedstock quality. Feedstock yield did not differ by crop, harvest time, or their interactions. Both grasses averaged 6.0 Mg ha-1 (fall) and 5.4 Mg ha-1 (spring) with similar high heating value (17.7 MJ kg-1). The K/(Ca + Mg) ratio, used as a quality indicator declined to below a 0.5 threshold, but energy yield (Megajoule per kilogram) decreased 13% by delaying harvest until spring. Only once during the four study-years were conditions ideal for early spring harvest, in contrast during another spring, very muddy conditions resulted in excessive soil contamination. Early spring harvest may be hampered by late snow, lodging, and muddy conditions that may delay or prevent harvest, and result in soil contamination of the feedstock. However, reducing slagging/fouling potential and the mass of mineral nutrients removed from the field without a dramatic loss in biomass or caloric content are reasons to delay harvest until spring.« less

Women and Peace [And] Vienna Conference: Women and Disarmament [And] Women, Power and Alternative Futures, Part I: Women and World Order [And] Women, Power and Alternative Futures, Part II: Women and Power. The Whole Earth Papers. Vol. 1, No. 6-8, Spring, 1978.

ERIC Educational Resources Information Center

Rubin, Josephine; Mische, Patricia

Four papers explore the role of women in promoting a peaceful world order. The volume is intended to increase understanding of the linkages between local and global issues, and to examine them as interrelated issues in an interdependent world. The first paper, "Women and Peace," is a historical analysis of the role of individual women, feminists,…

Solid state engine with alternating motion

DOEpatents

Golestaneh, Ahmad A.

1982-01-01

Heat energy is converted to mechanical motion utilizing apparatus including a cylinder, a piston having openings therein reciprocable in the cylinder, inlet and outlet ports for warm water at one end of the cylinder, inlet and outlet ports for cool water at the other end of the cylinder, gates movable with the piston and slidably engaging the cylinder wall to alternately open and close the warm and cool water ports, a spring bearing against the warm water side of the piston and a double helix of a thermal shape memory material attached to the cool end of the cylinder and to the piston. The piston is caused to reciprocate by alternately admitting cool water and warm water to the cylinder.

Solid state engine with alternating motion

DOEpatents

Golestaneh, A.A.

1980-01-21

Heat energy is converted to mechanical motion utilizing apparatus including a cylinder, a piston having openings therein reciprocable in the cylinder, inlet and outlet ports for warm water at one end of the cylinder, inlet and outlet ports for cool water at the other end of the cylinder, gates movable with the piston and slidably engaging the cylinder wall to alternately open and close the warm and cool water ports, a spring bearing against the warm water side of the piston and a double helix of a thermal shape memory material attached to the cool end of the cylinder and to the piston. The piston is caused to reciprocate by alternately admitting cool water and warm water to the cylinder.

The breaking load method - Results and statistical modification from the ASTM interlaboratory test program

NASA Technical Reports Server (NTRS)

Colvin, E. L.; Emptage, M. R.

1992-01-01

The breaking load test provides quantitative stress corrosion cracking data by determining the residual strength of tension specimens that have been exposed to corrosive environments. Eight laboratories have participated in a cooperative test program under the auspices of ASTM Committee G-1 to evaluate the new test method. All eight laboratories were able to distinguish between three tempers of aluminum alloy 7075. The statistical analysis procedures that were used in the test program do not work well in all situations. An alternative procedure using Box-Cox transformations shows a great deal of promise. An ASTM standard method has been drafted which incorporates the Box-Cox procedure.

Tips for longwall conveyor chain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Courtney, J.C.; Fortune, J.

1977-03-01

Mining chain must be capable of sustaining imposed loads of 80 or 90 percent of its minimum breaking strength, and still return to its original dimensions. This means that the chain should behave like an extremely sophisticated spring up to very high load levels, and return to its unloaded state without any plastic stretch or permanent dimensional deformation having taken place. This feature is absolutely essential, not only to enable repeat loadings to be made, but to ensure that constant, precise engagement of the drive and idler sprockets takes place. The mining chain production process, therefore, is carefully designed somore » that the last stage of manufacture introduces these necessary features.« less

Decreases in Maximal Oxygen Uptake Among Army Reserve Officers’ Training Corps Cadets Following Three Months Without Mandatory Physical Training

PubMed Central

LIGUORI, GARY; KREBSBACH, KASSIE; SCHUNA, JOHN

2012-01-01

During the academic year, Army ROTC cadets are required to participate in mandatory physical training; however, during summer months training is not required. The purpose of this study was to determine if there is a change in cadet VO2max after the summer when training is not mandatory. Participants completed a graded exercise treadmill test to determine their VO2max in late spring of 2010 and again in early fall of 2010. Results indicated that over a three-month break from mandatory physical training, a significant decrease in VO2max was seen for both genders in ROTC cadets. PMID:27182392

Homogenization of Mammalian Cells.

PubMed

de Araújo, Mariana E G; Lamberti, Giorgia; Huber, Lukas A

2015-11-02

Homogenization is the name given to the methodological steps necessary for releasing organelles and other cellular constituents as a free suspension of intact individual components. Most homogenization procedures used for mammalian cells (e.g., cavitation pump and Dounce homogenizer) rely on mechanical force to break the plasma membrane and may be supplemented with osmotic or temperature alterations to facilitate membrane disruption. In this protocol, we describe a syringe-based homogenization method that does not require specialized equipment, is easy to handle, and gives reproducible results. The method may be adapted for cells that require hypotonic shock before homogenization. We routinely use it as part of our workflow to isolate endocytic organelles from mammalian cells. © 2015 Cold Spring Harbor Laboratory Press.

Simulatng Sawtooth Mixers For Biofouling Mitigation

NASA Astrophysics Data System (ADS)

Waters, James; Balazs, Anna

2017-11-01

We demonstrate how a ridged surface can be used to generate vortices that will break up clusters of cells as they form. This offers an appealing avenue for fouling mitigation, as it relies on a physical mechanism without unintended environmental consequences. By adjusting the shape of these ridges, we can increase the effectiveness of the surface across a range of shear values. We represent such a system computationally using a hybrid of bulk fluid simulated via the lattice Boltzmann method, and deformable vesicles, representing cells, simulated via that lattice spring method. This simulation methodology allows us to rapidly implement and test different surface patterns, and explore how their parameters can most effectively deter the accumulation of biofilms.

Integrated Media: Toward a Theoretical Framework for Utilizing Their Potential.

ERIC Educational Resources Information Center

Journal of Special Education Technology, 1993

1993-01-01

This article discusses how current theories of learning and memory can guide the application of integrated media (IM) to embellish a standard curriculum; considers theoretical reasons for "breaking the mold"; and offers examples of IM-based alternatives to curricula in the areas of adult literacy, language arts, social studies, language skills,…

Breaking into the Movies: Pedagogy and the Politics of Film.

ERIC Educational Resources Information Center

Giroux, Henry A.

2001-01-01

Proposes that in addition to entertaining, film offers up subject positions; mobilizes desires; influences its audience unconsciously; and helps construct the landscape of American culture. Notes that film can provide a pedagogical tool for offering students alternative views of the world. Concludes that as a form of public pedagogy, film combines…

Act Local or Global?: Comparing Student Experiences in Domestic and International Service-Learning Programs

ERIC Educational Resources Information Center

Niehaus, Elizabeth; Crain, Léna Kavaliauskas

2013-01-01

International service-learning (ISL) is a popular way to facilitate student growth in the areas of cross-cultural learning and civic engagement. However, many have questioned whether international trips provide any added value compared to domestic service-learning. Using the context of Alternative Break programs, this study compares student…

Assessment of Matrix Multiplication Learning with a Rule-Based Analytical Model--"A Bayesian Network Representation"

ERIC Educational Resources Information Center

Zhang, Zhidong

2016-01-01

This study explored an alternative assessment procedure to examine learning trajectories of matrix multiplication. It took rule-based analytical and cognitive task analysis methods specifically to break down operation rules for a given matrix multiplication. Based on the analysis results, a hierarchical Bayesian network, an assessment model,…

Exploring the Role of Alternative Break Programs in Students' Career Development

ERIC Educational Resources Information Center

Niehaus, Elizabeth; Kurotsuchi Inkelas, Karen

2015-01-01

Higher education institutions play a key role in helping to shape students' interests and career plans; as such, student affairs practitioners should understand how the co-curricular environments in their domain contribute to students' career development. The purpose of this study is to explore how one specific co-curricular experience,…

A Diversity of Grammars: Breaking the Boundaries of "The Well Made Box."

ERIC Educational Resources Information Center

Sidler, Michelle

In his 1976 article, "Grammars of Style: New Options in Composition," Winston Weathers calls for a Grammar B, an alternate set of conventions which govern the construction of whole compositions. He urges compositionists to look beyond the "well-made box" and consider other options for compositional patterns and discourse…

Learning to Teach: Alternatives to Trial by Fire

ERIC Educational Resources Information Center

Trautmann, Nancy M.

2008-01-01

The traditional presumption in higher education that subject-matter knowledge is sufficient for effective teaching is breaking down. One cause of this change is the growing knowledge about how people learn, a consequence of which is a heightened focus on student-centered teaching practices. Another is the increasing diversity of students seeking…

The Graduate(S): The Harvests of Israel's Integrated Multicultural Bilingual Education

ERIC Educational Resources Information Center

Bekerman, Zvi

2018-01-01

Advocates of integration and cross cultural contact believe schools have a seminal role to play in perpetuating or breaking the cycle of violence and division in conflicted societies. Historically, segregated schools are the norm in such societies. An alternative educational model is provided through integrated schools--schools where children from…

Developmental changes in genetic and environmental influences on rule-breaking and aggression: age and pubertal development.

PubMed

Harden, K Paige; Patterson, Megan W; Briley, Daniel A; Engelhardt, Laura E; Kretsch, Natalie; Mann, Frank D; Tackett, Jennifer L; Tucker-Drob, Elliot M

2015-12-01

Antisocial behavior (ASB) can be meaningfully divided into nonaggressive rule-breaking versus aggressive dimensions, which differ in developmental course and etiology. Previous research has found that genetic influences on rule-breaking, but not aggression, increase from late childhood to mid-adolescence. This study tested the extent to which the developmental increase in genetic influence on rule-breaking was associated with pubertal development compared to chronological age. Child and adolescent twins (n = 1,031), ranging in age from 8 to 20 years (M age = 13.5 years), were recruited from public schools as part of the Texas Twin Project. Participants reported on their pubertal development using the Pubertal Development Scale and on their involvement in ASB on items from the Child Behavior Checklist. Measurement invariance of ASB subtypes across age groups (≤12 years vs. >12 years old) was tested using confirmatory factor analyses. Quantitative genetic modeling was used to test whether the genetic and environmental influences on aggression and rule-breaking were moderated by age, pubertal status, or both. Quantitative genetic modeling indicated that genetic influences specific to rule-breaking increased as a function of pubertal development controlling for age (a gene × puberty interaction), but did not vary as a function of age controlling for pubertal status. There were no developmental differences in the genetic etiology of aggression. Family-level environmental influences common to aggression and rule-breaking decreased with age, further contributing to the differentiation between these subtypes of ASB from childhood to adolescence. Future research should discriminate between alternative possible mechanisms underlying gene × puberty interactions on rule-breaking forms of antisocial behavior, including possible effects of pubertal hormones on gene expression. © 2015 Association for Child and Adolescent Mental Health.

Alternative end-joining pathway(s): bricolage at DNA breaks.

PubMed

Frit, Philippe; Barboule, Nadia; Yuan, Ying; Gomez, Dennis; Calsou, Patrick

2014-05-01

To cope with DNA double strand break (DSB) genotoxicity, cells have evolved two main repair pathways: homologous recombination which uses homologous DNA sequences as repair templates, and non-homologous Ku-dependent end-joining involving direct sealing of DSB ends by DNA ligase IV (Lig4). During the last two decades a third player most commonly named alternative end-joining (A-EJ) has emerged, which is defined as any Ku- or Lig4-independent end-joining process. A-EJ increasingly appears as a highly error-prone bricolage on DSBs and despite expanding exploration, it still escapes full characterization. In the present review, we discuss the mechanism and regulation of A-EJ as well as its biological relevance under physiological and pathological situations, with a particular emphasis on chromosomal instability and cancer. Whether or not it is a genuine DSB repair pathway, A-EJ is emerging as an important cellular process and understanding A-EJ will certainly be a major challenge for the coming years. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Effect of alternating day and night temperature on short day-induced bud set and subsequent bud burst in long days in Norway spruce

PubMed Central

Olsen, Jorunn E.; Lee, YeonKyeong; Junttila, Olavi

2014-01-01

Young seedlings of the conifer Norway spruce exhibit short day (SD)-induced cessation of apical growth and bud set. Although different, constant temperatures under SD are known to modulate timing of bud set and depth of dormancy with development of deeper dormancy under higher compared to lower temperature, systematic studies of effects of alternating day (DT) and night temperatures (NT) are limited. To shed light on this, seedlings of different provenances of Norway spruce were exposed to a wide range of DT-NT combinations during bud development, followed by transfer to forcing conditions of long days (LD) and 18°C, directly or after different periods of chilling. Although no specific effect of alternating DT/NT was found, the results demonstrate that the effects of DT under SD on bud set and subsequent bud break are significantly modified by NT in a complex way. The effects on bud break persisted after chilling. Since time to bud set correlated with the daily mean temperature under SD at DTs of 18 and 21°C, but not a DT of 15°C, time to bud set apparently also depend on the specific DT, implying that the effect of NT depends on the actual DT. Although higher temperature under SD generally results in later bud break after transfer to forcing conditions, the fastest bud flush was observed at intermediate NTs. This might be due to a bud break-hastening chilling effect of intermediate compared to higher temperatures, and delayed bud development to a stage where bud burst can occur, under lower temperatures. Also, time to bud burst in un-chilled seedlings decreased with increasing SD-duration, suggesting that bud development must reach a certain stage before the processes leading to bud burst are initiated. The present results also indicate that low temperature during bud development had a larger effect on the most southern compared to the most northern provenance studied. Decreasing time to bud burst was observed with increasing northern latitude of origin in un-chilled as well as chilled plants. In conclusion, being a highly temperature-dependent process, bud development is strongly delayed by low temperature, and the effects of DT is significantly modified by NT in a complex manner. PMID:25538722

Negotiating an ecological barrier: crossing the Sahara in relation to winds by common swifts

PubMed Central

2016-01-01

The Sahara Desert is one of the largest land-based barriers on the Earth, crossed twice each year by billions of birds on migration. Here we investigate how common swifts migrating between breeding sites in Sweden and wintering areas in sub-Saharan Africa perform the desert crossing with respect to route choice, winds, timing and speed of migration by analysing 72 geolocator tracks recording migration. The swifts cross western Sahara on a broad front in autumn, while in spring they seem to use three alternative routes across the Sahara, a western, a central and an eastern route across the Arabian Peninsula, with most birds using the western route. The swifts show slower migration and travel speeds, and make longer detours with more stops in autumn compared with spring. In spring, the stopover period in West Africa coincided with mostly favourable winds, but birds remained in the area, suggesting fuelling. The western route provided more tailwind assistance compared with the central route for our tracked swifts in spring, but not in autumn. The ultimate explanation for the evolution of a preferred western route is presumably a combination of matching rich foraging conditions (swarming insects) and favourable winds enabling fast spring migration. This article is part of the themed issue ‘Moving in a moving medium: new perspectives on flight’. PMID:27528783

Low band gap frequencies and multiplexing properties in 1D and 2D mass spring structures

NASA Astrophysics Data System (ADS)

Aly, Arafa H.; Mehaney, Ahmed

2016-11-01

This study reports on the propagation of elastic waves in 1D and 2D mass spring structures. An analytical and computation model is presented for the 1D and 2D mass spring systems with different examples. An enhancement in the band gap values was obtained by modeling the structures to obtain low frequency band gaps at small dimensions. Additionally, the evolution of the band gap as a function of mass value is discussed. Special attention is devoted to the local resonance property in frequency ranges within the gaps in the band structure for the corresponding infinite periodic lattice in the 1D and 2D mass spring system. A linear defect formed of a row of specific masses produces an elastic waveguide that transmits at the narrow pass band frequency. The frequency of the waveguides can be selected by adjusting the mass and stiffness coefficients of the materials constituting the waveguide. Moreover, we pay more attention to analyze the wave multiplexer and DE-multiplexer in the 2D mass spring system. We show that two of these tunable waveguides with alternating materials can be employed to filter and separate specific frequencies from a broad band input signal. The presented simulation data is validated through comparison with the published research, and can be extended in the development of resonators and MEMS verification.

Spring-fall asymmetry of substorm strength, geomagnetic activity and solar wind: Implications for semiannual variation and solar hemispheric asymmetry

USGS Publications Warehouse

Mursula, K.; Tanskanen, E.; Love, J.J.

2011-01-01

We study the seasonal variation of substorms, geomagnetic activity and their solar wind drivers in 1993-2008. The number of substorms and substorm mean duration depict an annual variation with maxima in Winter and Summer, respectively, reflecting the annual change of the local ionosphere. In contradiction, substorm mean amplitude, substorm total efficiency and global geomagnetic activity show a dominant annual variation, with equinoctial maxima alternating between Spring in solar cycle 22 and Fall in cycle 23. The largest annual variations were found in 1994 and 2003, in the declining phase of the two cycles when high-speed streams dominate the solar wind. A similar, large annual variation is found in the solar wind driver of substorms and geomagnetic activity, which implies that the annual variation of substorm strength, substorm efficiency and geomagnetic activity is not due to ionospheric conditions but to a hemispherically asymmetric distribution of solar wind which varies from one cycle to another. Our results imply that the overall semiannual variation in global geomagnetic activity has been seriously overestimated, and is largely an artifact of the dominant annual variation with maxima alternating between Spring and Fall. The results also suggest an intimate connection between the asymmetry of solar magnetic fields and some of the largest geomagnetic disturbances, offering interesting new pathways for forecasting disturbances with a longer lead time to the future. Copyright ?? 2011 by the American Geophysical Union.

Diverse landscapes have a higher abundance and species richness of spring wild bees by providing complementary floral resources over bees’ foraging periods

USDA-ARS?s Scientific Manuscript database

Landscape simplification and natural habitat loss can negatively affect wild bees. Alternatively, anthropogenic land-use change can potentially diversify landscapes to create complementary habitats that increase overall resource continuity and diversity. We examined the effects of landscape composit...

77 FR 43808 - Advisory Committee and Species Working Group Technical Advisor Appointment

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-26

... sent via email ( Rachel.O'Malley@noaa.gov ). In the alternative, nominations may be sent via mail to Rachel O'Malley at NMFS, Office of International Affairs, Room 12622, 1315 East-West Highway, Silver Spring, MD 20910. FOR FURTHER INFORMATION CONTACT: Rachel O'Malley, Office of International Affairs, 301...

Yield potential of spring-harvested sugar beet depends on autumn planting time

USDA-ARS?s Scientific Manuscript database

Sugar crops grown for biofuel production provide a source of simple sugars that can readily be made into advanced biofuels. In the mild climate of the southeastern USA, sugar beet can be grown as a winter crop, providing growers with an alternative crop. Experiments evaluated autumn planting dates...

Initial bird responses to alternative pine regeneration methods in Arkansas and Oklahoma: preliminary findings

Treesearch

Ronald E. Thill; Roger W. Perry; Nancy E. Koerth; Philip A. Tappe; David G. Peitz

2004-01-01

Abstract - We studied spring songbird communities in a predominantly forested landscape in the Ouachita Mountains of west-central Arkansas and eastern Oklahoma. Relative bird abundance, species richness, diversity, and evenness values are presented for the first, third, and fifth years following harvesting in four replications of four regeneration...

Music in the First-Year Writing Classroom

ERIC Educational Resources Information Center

Strovas, Scott

2011-01-01

"Primary research counts, but we don't teach it." This was the sentiment, if these were not the actual words, of Lynee Lewis Gaillet in her critique of the traditional composition curriculum at the spring 2011 annual meeting of the College English Association in St. Petersburg. Gaillet proposes an alternative to furthering students' sometimes…

Web-Based Mathematics Progress Monitoring in Second Grade

ERIC Educational Resources Information Center

Salaschek, Martin; Souvignier, Elmar

2014-01-01

We examined a web-based mathematics progress monitoring tool for second graders. The tool monitors the learning progress of two competences, number sense and computation. A total of 414 students from 19 classrooms in Germany were checked every 3 weeks from fall to spring. Correlational analyses indicate that alternate-form reliability was adequate…

Managing cool-season weeds in sugarbeet grown for biofuel in the Southeastern U.S.

USDA-ARS?s Scientific Manuscript database

Sugarbeet, grown for biofuel, is being considered as an alternate cool-season crop in the southeastern U. S. coastal plain. Typically, the crop would be seeded in the autumn, grow through the winter, and harvested the following spring. Labels for herbicides registered for use on sugarbeet grown in ...

Creating orbiting vorticity vectors in magnetic particle suspensions through field symmetry transitions–a route to multi-axis mixing

DOE PAGES

Martin, James E.; Solis, Kyle Jameson

2015-11-09

It has recently been reported that two types of triaxial electric or magnetic fields can drive vorticity in dielectric or magnetic particle suspensions, respectively. The first type-symmetry -- breaking rational fields -- consists of three mutually orthogonal fields, two alternating and one dc, and the second type -- rational triads -- consists of three mutually orthogonal alternating fields. In each case it can be shown through experiment and theory that the fluid vorticity vector is parallel to one of the three field components. For any given set of field frequencies this axis is invariant, but the sign and magnitude ofmore » the vorticity (at constant field strength) can be controlled by the phase angles of the alternating components and, at least for some symmetry-breaking rational fields, the direction of the dc field. In short, the locus of possible vorticity vectors is a 1-d set that is symmetric about zero and is along a field direction. In this paper we show that continuous, 3-d control of the vorticity vector is possible by progressively transitioning the field symmetry by applying a dc bias along one of the principal axes. Such biased rational triads are a combination of symmetry-breaking rational fields and rational triads. A surprising aspect of these transitions is that the locus of possible vorticity vectors for any given field bias is extremely complex, encompassing all three spatial dimensions. As a result, the evolution of a vorticity vector as the dc bias is increased is complex, with large components occurring along unexpected directions. More remarkable are the elaborate vorticity vector orbits that occur when one or more of the field frequencies are detuned. As a result, these orbits provide the basis for highly effective mixing strategies wherein the vorticity axis periodically explores a range of orientations and magnitudes.« less

Observations of large-amplitude cross-shore internal bores near the shelf break, Santa Monica Bay, CA

USGS Publications Warehouse

Noble, M.A.; Xu, J. P.

2003-01-01

Two sets of moorings were deployed along a cross-shelf transect in central Santa Monica bay for four months in the winter of 1998-1999. Both sites had an array of instruments attached to tripods set on the seafloor to monitor currents over the entire water column, surface waves, near-bed temperature, water clarity and suspended sediment. A companion mooring had temperature sensors spaced approximately 10 m apart to measure temperature profiles between the surface and the seafloor. One array was deployed in 70 m of water at a site adjacent to the shelf break, just northwest of a major ocean outfall. The other was deployed on the mid shelf in 35 m of water approximately 6 km from the shelf break site. The subtidal currents in the region flowed parallel to the isobaths with fluctuating time scales around 10 days, a typical coastal-ocean pattern. However, during the falling phase of the barotropic spring tide, sets of large-amplitude, sheared cross-shore current pulses with a duration of 2-5 h were observed at the shelf break site. Currents in these pulses flowed exclusively offshore in a thin layer near the bed with amplitudes reaching 30-40 cm/s. Simultaneously, currents with amplitudes around 15-20 cm/s flowed exclusively onshore in the thicker layer between the offshore flow layer and the sea surface. The net offshore transport was about half the onshore transport. Near-surface isotherms were depressed 30-40 m. These pulses were likely internal bores generated by tidal currents. Bed stresses associated with these events exceeded 3 dynes/cm2. These amplitudes are large enough to resuspend and transport not only fine-grained material, but also medium to coarse sands from the shelf toward the slope. Consequently, the seafloor over the shelf break was swept clear of fine sediments. The data suggest that the internal bores dissipate and are reduced in amplitude as they propagate across this relatively narrow shelf. There is evidence that they reach the 35 m site, but other coastal ocean processes obscure their distinctive characteristics.

Beaver herbivory of willow under two flow regimes: A comparative study on the Green and Yampa rivers

USGS Publications Warehouse

Breck, Stewart W.; Wilson, Kenneth R.; Andersen, Douglas C.

2003-01-01

The effect of flow regulation on plant-herbivore ecology has received very little attention, despite the fact that flow regulation can alter both plant and animal abundance and environmental factors that mediate interactions between them. To determine how regulated flows have impacted beaver (Castor canadensis) and sandbar willow (Salix exigua) ecology, we first quantified the abundance and mapped the spatial distribution of sandbar willow on alluvial sections of the flow-regulated Green River and free-flowing Yampa River in northwestern Colorado. We then established 16 and 15 plots (1 m × 2.7 m) in patches of willow on the Green and Yampa Rivers, respectively, to determine whether rates of beaver herbivory of willow differed between rivers (Green versus Yampa River), seasons (fall-winter versus spring-summer), and years (spring 1998-spring 1999 versus spring 1999-spring 2000). Areal extent of willow was similar on each river, but Green River willow patches were smaller and more numerous. Beavers cut more stems during fall and winter than spring and summer and cut over 6 times more stems (percentage basis) on the Green River than on the Yampa River. We attribute the between-river difference in herbivory to higher availability of willow, greater beaver density, and lower availability of young Fremont cottonwood (Populus deltoides subsp. wislizenii; an alternative food source) on the Green River. Flow regulation increased willow availability to beaver by promoting the formation of island patches that are continuously adjacent to water and feature a perimeter with a relatively high proportion of willow interfacing with water.

Proposed plan for remedial action for the Groundwater Operable Unit at the Chemical Plant Area of the Weldon Spring Site, Weldon Spring, Missouri

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1999-08-10

This Proposed Plan addresses the remediation of groundwater contamination at the chemical plant area of the Weldon Spring site in Weldon Spring, Missouri. The site is located approximately 48 km (30 mi) west of St. Louis in St. Charles County . Remedial activities at the site will be conducted in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). The U.S. Department of Energy (DOE), in conjunction with the U.S. Department of the Army (DA), conducted a joint remedial investigation/feasibility study (RI/FS) to allow for a comprehensive evaluation of groundwater conditions at the Weldon Spring chemical plant areamore » and the Weldon Spring ordnance works area, which is an Army site adjacent to the chemical plant area. Consistent with DOE policy, National Environmental Policy Act (NEPA) values have been incorporated into the CERCLA process. That is, the analysis conducted and presented in the RVFS reports included an evaluation of environmental impacts that is comparable to that performed under NEPA. This Proposed Plan summarizes information about chemical plant area groundwater that is presented in the following documents: (1) The Remedial Investigation (RI), which presents information on the nature and extent of contamination; (2) The Baseline Risk Assessment (BRA), which evaluates impacts to human health and the environment that could occur if no cleanup action of the groundwater were taken (DOE and DA 1997a); and (3) The Feasibility Study (FS) and the Supplemental FS, which develop and evaluate remedial action alternatives for groundwater remediation.« less

[Influences of tide on silicon and nitrogen contents in soil and porewater in the Minjiang Ri-ver estuary, Southeast China].

PubMed

Hou, Guan Yun; Zhai, Shui Jing; Le, Xiao Qing; Tong, Chuan

2017-01-01

Taking Shanyuntan wetland in the Minjiang River estuary as test object, the dissolved silicates (DSi) and inorganic nitrogen contents in porewater and the biogenic silica (BSi) and total nitrogen contents in surface soil of the Phragmites australis wetland, Cyperus malaccensis wetland and Spartina alterniflora wetland were measured in October 2014 (spring tide month) and April 2015 (neap tide month), respectively, to illuminate the influence of tide on silicon and nitrogen contents in soil and porewater of estuarine wetland. Results showed that the DSi content in porewater and the BSi content in surface soil in spring tide month were slightly higher than those in neap tide month, with the highest being observed on neap tide day and the lowest occurring on spring tide day. In contrast, the BSi content in surface soil on spring tide day showed an opposite trend with that on neap tide day. The contents of NH 4 + -N and NO 3 - -N in porewater of different wetland soils in spring tide month were higher than those in neap tide month, while the content of NH 4 + -N on spring tide day was significantly higher than that on neap tide day (P<0.05). The study found that hydrological conditions such as flooding duration and drying-wetting alternation caused by tide had great influences on silicon and nitrogen contents in porewater and surface soil, and vegetation types also showed great influences on their distributions in intertidal wetland of the Minjiang River estuary.

Persistent 3'-phosphate termini and increased cytotoxicity of radiomimetic DNA double-strand breaks in cells lacking polynucleotide kinase/phosphatase despite presence of an alternative 3'-phosphatase.

PubMed

Chalasani, Sri Lakshmi; Kawale, Ajinkya S; Akopiants, Konstantin; Yu, Yaping; Fanta, Mesfin; Weinfeld, Michael; Povirk, Lawrence F

2018-05-25

Polynucleotide kinase/phosphatase (PNKP) has been implicated in non-homologous end joining (NHEJ) of DNA double-strand breaks (DSBs). To assess the consequences of PNKP deficiency for NHEJ of 3'-phosphate-ended DSBs, PNKP-deficient derivatives of HCT116 and of HeLa cells were generated using CRISPR/CAS9. For both cell lines, PNKP deficiency conferred sensitivity to ionizing radiation as well as to neocarzinostatin (NCS), which specifically induces DSBs bearing protruding 3'-phosphate termini. Moreover, NCS-induced DSBs, detected as 53BP1 foci, were more persistent in PNKP -/- HCT116 cells compared to their wild-type (WT) counterparts. Surprisingly, PNKP-deficient whole-cell and nuclear extracts were biochemically competent in removing both protruding and recessed 3'-phosphates from synthetic DSB substrates, albeit much less efficiently than WT extracts, suggesting an alternative 3'-phosphatase. Measurements by ligation-mediated PCR showed that PNKP-deficient HeLa cells contained significantly more 3'-phosphate-terminated and fewer 3'-hydroxyl-terminated DSBs than parental cells 5-15 min after NCS treatment, but this difference disappeared by 1 h. These results suggest that, despite presence of an alternative 3'-phosphatase, loss of PNKP significantly sensitizes cells to 3'-phosphate-terminated DSBs, due to a 3'-dephosphorylation defect. Copyright © 2018 Elsevier B.V. All rights reserved.

Subjective Measurements of In-Flight Sleep, Circadian Variation, and Their Relationship with Fatigue.

PubMed

van den Berg, Margo J; Wu, Lora J; Gander, Philippa H

This study examined whether subjective measurements of in-flight sleep could be a reliable alternative to actigraphic measurements for monitoring pilot fatigue in a large-scale survey. Pilots (3-pilot crews) completed a 1-page survey on outbound and inbound long-haul flights crossing 1-7 time zones (N = 586 surveys) between 53 city pairs with 1-d layovers. Across each flight, pilots documented flight start and end times, break times, and in-flight sleep duration and quality if they attempted sleep. They also rated their fatigue (Samn-Perelli Crew Status Check) and sleepiness (Karolinska Sleepiness Scale) at top of descent (TOD). Mixed model ANCOVA was used to identify independent factors associated with sleep duration, quality, and TOD measures. Domicile time was used as a surrogate measure of circadian phase. Sleep duration increased by 10.2 min for every 1-h increase in flight duration. Sleep duration and quality varied by break start time, with significantly more sleep obtained during breaks starting between (domicile) 22:00-01:59 and 02:00-05:59 compared to earlier breaks. Pilots were more fatigued and sleepy at TOD on flights arriving between 02:00-05:59 and 06:00-09:59 domicile time compared to other flights. With every 1-h increase in sleep duration, sleepiness ratings at TOD decreased by 0.6 points and fatigue ratings decreased by 0.4 points. The present findings are consistent with previous actigraphic studies, suggesting that self-reported sleep duration is a reliable alternative to actigraphic sleep in this type of study, with use of validated measures, sufficiently large sample sizes, and where fatigue risk is expected to be low. van den Berg MJ, Wu LJ, Gander PH. Subjective measurements of in-flight sleep, circadian variation, and their relationship with fatigue. Aerosp Med Hum Perform. 2016; 87(10):869-875.

Continuous earlywood vessels chronologies in floodplain ring-porous species can improve dendrohydrological reconstructions of spring high flows and flood levels

NASA Astrophysics Data System (ADS)

Kames, S.; Tardif, J. C.; Bergeron, Y.

2016-03-01

Plants respond to environmental stimuli through changes in growth and development. Characteristics of wood cells such as the cross-sectional area of vessel elements (hereafter referred to as vessels) may store information about environmental factors present at the time of vessel differentiation. The analysis of vessel characteristics therefore offers a different time resolution than annual ring width because vessels in tree rings differentiate within days to a few weeks. Little research has been conducted on the sensitivity of earlywood vessels in ring-porous species in response to flooding. The general objectives of this study were to determine the plasticity of earlywood vessel to high flows and spring flooding in floodplain black ash (Fraxinus nigra Marsh.) trees and to assess the utility of developing continuous earlywood vessel chronologies in dendrohydrological reconstruction. In contrast, most dendrohydrological studies until now have mainly used vessel anomalies (flood rings) as discrete variables to identify exceptional flood events. The study area is located in the boreal region of northwestern Québec. Vessel and ring-width chronologies were generated from F. nigra trees growing on the floodplain of Lake Duparquet. Spring discharge had among all hydro-climatic variables the strongest impact on vessel formation and this signal was coherent spatially and in the frequency domain. The mean vessel area chronology was significantly and negatively correlated to discharge and both the linearity and the strength of this association were unique. In floodplain F. nigra trees, spring flooding promoted the formation of more abundant but smaller earlywood vessels. Earlywood vessels chronologies were also significantly associated with other hydrological indicators like Lake Duparquet's ice break-up date and both ice-scar frequency and height chronologies. These significant relationships stress the utility of developing continuous vessels chronologies for hydrological reconstructions prior to instrumental data. Continuous earlywood vessel chronologies may also be useful in determining the impact of altered hydrological regime in floodplain habitat regulated by spring floods. Future research should involve quantifying the impact of high flows and flooding on other cell constituents and also determining the plasticity and utility of continuous anatomical series in floodplain diffuse-porous species.

The role of spring precipitation deficits on European and North American summer heat wave activity

NASA Astrophysics Data System (ADS)

Cowan, Tim; Hegerl, Gabi

2017-04-01

Heat waves are relatively short-term climate phenomena with potentially severe societal impacts, particularly on health, agriculture and the natural environment. In water-limited regions, increased heat wave activity over intra-decadal periods is often associated with protracted droughts, as observed over North America's Central and Southern Great Plains in the 1930s and 1950s, highlighting the importance of land surface-atmosphere feedbacks. Here we present an analysis of the covariability of spring precipitation deficit and summer heat waves for North America and Europe, the latter having experienced an increase in summer heat wave frequency since the 1950s (Perkins et al. 2012). Over the Great Plains summer heat waves are significantly earlier, longer and hotter if following dry rather than wet springs, with the mega-heat waves of the 1930s Dust Bowl decade an extreme example (e.g. Cowan et al. 2017). Similar relationships can be found in some parts of Europe for heat wave frequency and duration, namely Southern and Eastern Europe, although the heat wave timing and amplitude (i.e. the hottest events) appear less sensitive to spring drying. Climate model results investigating the relationship between heat waves and precipitation deficit in regions in Europe and North America will also be presented. It is necessary to pinpoint the causes of large decadal variations in heat wave metrics, as seen in the 1930s over North America and more recently across Central Europe, for event attribution purposes and to improve near-decadal prediction. The tight link between spring drought and summer heat waves will also be important for understanding the impacts of these climatic events and supports the development of compound event analysis techniques. References: Cowan, T., G. Hegerl, I. Colfescu, A. Purich and G. Boshcat (2016), Factors contributing to record-breaking heat waves over the Great Plains during the 1930s Dust Bowl. Journal of Climate, doi: 10.1175/JCLI-D-16-0436.1 (in press). Perkins, S. E., L. V. Alexander, and J. R. Nairn (2012), Increasing frequency, intensity and duration of observed global heatwaves and warm spells, Geophys. Res. Lett., 39, L20714, doi:10.1029/2012GL053361.

HiRISE observations of gas sublimation-driven activity in Mars' southern polar regions: III. Models of processes involving translucent ice

USGS Publications Warehouse

Portyankina, G.; Markiewicz, W.J.; Thomas, N.; Hansen, C.J.; Milazzo, M.

2010-01-01

Enigmatic surface features, known as 'spiders', found at high southern martian latitudes, are probably caused by sublimation-driven erosion under the seasonal carbon dioxide ice cap. The Mars Reconnaissance Orbiter (MRO) High Resolution Imaging Science Experiment (HiRISE) has imaged this terrain in unprecedented details throughout southern spring. It has been postulated [Kieffer, H.H., Titus, T.N., Mullins, K.F., Christensen, P.R., 2000. J. Geophys. Res. 105, 9653-9700] that translucent CO2 slab ice traps gas sublimating at the ice surface boundary. Wherever the pressure is released the escaping gas jet entrains loose surface material and carries it to the top of the ice where it is carried downslope and/or downwind and deposited in a fan shape. Here we model two stages of this scenario: first, the cleaning of CO2 slab ice from dust, and then, the breaking of the slab ice plate under the pressure built below it by subliming ice. Our modeling results and analysis of HiRISE images support the gas jet hypothesis and show that outbursts happen very early in spring. ?? 2009 Elsevier Inc. All rights reserved.

Breaking the Institutional Mold: Implications of Alternative Systems for Postsecondary/Higher Education.

ERIC Educational Resources Information Center

Feinsot, Aaron; Sigel, Efrem

Colleges and universities throughout the country are presently faced with responding to a crisis that could mean their very existence. The move toward mass education is well on its way and few administrators have grasped the speed or direction of the changes overwhelming them, especially those changes involving new social attitudes and…

Applying Social Psychology to Reveal a Major (But Correctable) Flaw in Student Evaluations of Teaching.

ERIC Educational Resources Information Center

Greenwald, Anthony G.

Higher education relies on student ratings to evaluate faculty teaching, partly because the alternatives (expert peer appraisals or objective performance criteria) are costly or unavailable. Because student ratings are crucial not only to improving instruction, but also in making or breaking faculty careers, it is important to assure that they…

Women Break Through: Students At Work. La Mujer Adelanta: Alumnos Trabajando. A Teachers Guide.

ERIC Educational Resources Information Center

New York City Board of Education, Brooklyn, NY. Div. of Curriculum and Instruction.

This document is a teachers guide explaining the purpose and contents of an educational radio series in Brooklyn, New York which dramatizes the issues affecting the roles of women who are first entering the work force, and explores opportunities for alternative career choices. Part one examines the cooperative education programs, the executive…

Social Guarantee Programme: Principles for Classroom Procedure with Students Who Have Suffered Failure at School--The Spanish Educational System Case

ERIC Educational Resources Information Center

Recio, R. Vazquez; Diaz, J. Ojeda

2010-01-01

The article explores the Social Guarantee Programmes, one measure at attending to diversity within the Spanish educational system. It is an alternative measure that aims to break away from the organisational structure of Obligatory Secondary Education, seeking an organisational model and educational strategies that pursue satisfactory results…

Changes in fire regime break the legacy lock on successional trajectories in Alaskan boreal forest

Treesearch

Jill F. Johnstone; Teresa N. Hollingsworth; F. Stuart Chapin; Michelle C. Mack

2009-01-01

Predicting plant community responses to changing environmental conditions is a key element of forecasting and mitigating the effects of global change. Disturbance can play an important role in these dynamics, by initiating cycles of secondary succession and generating opportunities for communities of long-lived organisms to reorganize in alternative configurations....

Managing the Grey Literature of a Discipline through Collaboration: AgEcon Search

ERIC Educational Resources Information Center

Kelly, Julia; Letnes, Louise

2005-01-01

AgEcon Search, http://www.agecon.lib.umn.edu, is an important and ground-breaking example of an alternative method of delivering current research results to many potential users. AgEcon Search, through a distributed model, collects and disseminates the grey literature of the fields of agricultural and resource economics. The development of this…

Cadmium telluride solar cells: Record-breaking voltages

DOE PAGES

Poplawsky, Jonathan D.

2016-01-01

Here, the performance of CdTe solar cells — cheaper alternatives to silicon photovoltaics — is hampered by their low output voltages, which are normally well below the theoretical limit. Now, record voltages of over 1 V have been reported in single-crystal CdTe heterostructure solar cells, which are close to those of benchmark GaAs cells.

Phenology and drivers of the winter-spring phytoplankton bloom in the open Black Sea: The application of Sverdrup's hypothesis and its refinements

NASA Astrophysics Data System (ADS)

Mikaelyan, Alexander S.; Chasovnikov, Valeriy K.; Kubryakov, Arseny A.; Stanichny, Sergey V.

2017-02-01

The phenology of the winter-spring phytoplankton bloom in the Black Sea was investigated on the basis of the satellite-derived chlorophyll concentration (Chl) for the recent 18-year period. Data for the 8-day Chl were analysed, together with changes in the nutrient concentration, sea surface temperature (SST), photosynthetically available radiation, wind velocity and duration. Based on Sverdrup's Critical Depth hypothesis and its recent refinements, the Pulsing-Bloom hypothesis was proposed for the highly stratified waters of the Black Sea. This hypothesis relates the biological response to physical forcing and chemical fluxes to the photic zone and predicts the pulsing growth of phytoplankton and different patterns of phytoplankton changes in the upper layer in winter-spring during cold and regular years. The hypothesis was supported by Chl dynamics and several Chl peaks were observed during winter-spring. Normally, the highest Chl occurred in winter and a spring peak was absent, whereas in cold years, a relatively low Chl in winter was followed by a spring bloom. These events were observed only in 15% of cases and the magnitude of the bloom was associated with the intensity of winter convection that was revealed by the negative inter-annual correlation between the March Chl and the February SST. In contrast, the February Chl was positively correlated with the SST. The proposed hypothesis provides an explanation of this phenomenon on the basis of an alternation between the low-turbulence and deep-mixing regimes. This mechanism was confirmed by the positive relationships between Chl and the duration of light wind during the current period and strong wind in the previous period. Inorganic nitrogen was depleted disproportionately during the winter-spring, whereas the phosphate concentration remained relatively high. Following a cold winter, the highest phosphate concentration and extremely low nitrogen-to-phosphorus molar ratios (2) were observed in the upper 25-m layer in late spring. The regular absence of spring blooms might represent one of the consequences of the regional climate change.

Overview of Alternative Bunching and Current-shaping Techniques for Low-Energy Electron Beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Piot, Philippe

2015-12-01

Techniques to bunch or shape an electron beam at low energies (E <15 MeV) have important implications toward the realization of table-top radiation sources [1] or to the design of compact multi-user free-electron lasers[2]. This paper provides an overview of alternative methods recently developed including techniques such as wakefield-based bunching, space-charge-driven microbunching via wave-breaking [3], ab-initio shaping of the electron-emission process [4], and phase space exchangers. Practical applications of some of these methods to foreseen free-electron-laser configurations are also briefly discussed [5].

An alternative mechanism for radioprotection by dimethyl sulfoxide; possible facilitation of DNA double-strand break repair.

PubMed

Kashino, Genro; Liu, Yong; Suzuki, Minoru; Masunaga, Shin-ichiro; Kinashi, Yuko; Ono, Koji; Tano, Keizo; Watanabe, Masami

2010-01-01

The radioprotective effects of dimethyl sulfoxide (DMSO) have been known for many years, and the suppression of hydroxyl (OH) radicals induced by ionizing radiation has been thought to be the main cause of this effect. However, the DMSO concentration used was very high, and might be toxic, in earlier studies. In the present study, we administered a lower, non-toxic concentration (0.5%, i.e., 64 mM) of DMSO before irradiation and examined its radioprotective effects. Colony formation assay and micronucleus assay showed significant radioprotective effects in CHO, but not in xrs5, which is defective in the repair function of DNA double-strand breaks. The levels of phosphorylated H2AX and the formation of 53BP1 foci 15 minutes after irradiation, which might reflect initial DNA double-strand breaks, in DMSO-treated CHO cells were similar to those in non-treated cells, suggesting that the radioprotective effects were not attributable to the suppression of general indirect action in the lower concentration of DMSO. On the other hand, 2 hours after irradiation, the average number of 53BP1 foci, which might reflect residual DNA double-strand breaks, was significantly decreased in DMSO-treated CHO cells compared to non-treated cells. The results indicated that low concentration of DMSO exerts radioprotective effects through the facilitation of DNA double-strand break repair rather than through the suppression of indirect action.

Behavior modification after inactivation of cerebellar dentate nuclei.

PubMed

Peterson, Todd C; Villatoro, Lee; Arneson, Tom; Ahuja, Brittany; Voss, Stephanie; Swain, Rodney A

2012-08-01

Effort-based decision making occurs when subjects are given a choice between a reward available at a high response cost and a reward available at a low response cost and is altered in individuals with disorders such as autism or particular patterns of brain injury. The current study explored the relationship between effort-based decision making and reinforcement characteristics in the T maze. This was done using both normal animals and animals with bilateral inactivation of the cerebellar dentate nuclei. Rats chose between alternatives in which one arm contained high-density reinforcement (HR) and the other arm contained low-density reinforcement (LR). During training, the HR arm was obstructed and the point at which the animal no longer worked for reinforcement (breaking point) was determined. The cerebellar dentate nuclei were then transiently inactivated and once again breaking points were assessed. The results indicated that inactivation of the dentate nucleus disrupted effort-based decision making. Additionally, altering both the palatability and the magnitude of the reinforcement were assessed in an attempt to reestablish the original preinactivation breaking point. It was hypothesized that an increase in the strength or magnitude of the reinforcement would promote an increase in the breaking point of the animal even when the cerebellum was inactivated. The results indicated that with both strategies animals effectively reestablished original breaking points. The results of this study will inform the current literature regarding the modification of behavior after brain injury and further the understanding of the behavioral deficits associated with cerebellar dysfunction.

Acoustic nonreciprocity in Coriolis mean flow systems.

PubMed

Naghdi, Masoud; Farzbod, Farhad

2018-01-01

One way to break acoustic reciprocity is to have a moving wave propagation medium. If the acoustic wave vector and the moving fluid velocity are collinear, the wave vector shift caused by the fluid flow can be used to break. In this paper, an alternative approach is investigated in which the fluid velocity enters the differential equation of the system as a cross product term with the wave vector. A circular field where the fluid velocity increases radially has a Coriolis acceleration term. In such a system, the acoustic wave enters from the central wall and exits from the perimeter wall. In this paper, the differential equation is solved numerically and the effect of fluid velocity on the nonreciprocity factor is examined.

Higgsless approach to electroweak symmetry breaking

NASA Astrophysics Data System (ADS)

Grojean, Christophe

2007-11-01

Higgsless models are an attempt to achieve a breaking of the electroweak symmetry via boundary conditions at the end-points of a fifth dimension compactified on an interval, as an alternative to the usual Higgs mechanism. There is no physical Higgs scalar in the spectrum and the perturbative unitarity violation scale is delayed via the exchange of massive spin-1 KK resonances. The correct mass spectrum is reproduced in a model in warped space, which inherits a custodial symmetry from a left-right gauge symmetry in the bulk. Phenomenological challenges as well as collider signatures are presented. From the AdS/CFT perspective, this model appears as a weakly coupled dual to walking technicolour models. To cite this article: C. Grojean, C. R. Physique 8 (2007).

Spontaneous PT symmetry breaking in Dirac-Kronig-Penney crystals

NASA Astrophysics Data System (ADS)

Longhi, Stefano; Cannata, Francesco; Ventura, Alberto

2011-12-01

We introduce a non-Hermitian PT invariant extension of the Dirac-Kronig-Penney model, describing the motion of a Dirac quasiparticle in a locally periodic sequence of imaginary δ-Dirac barriers and wells, and propose its optical realization using superstructure fiber Bragg gratings with alternating regions of optical gain and absorption. For the infinite crystal, we determine the band structure and show that the PT phase is always broken. For a finite crystal, we derive analytical expressions for reflection and transmission probabilities, and show that the PT phase is unbroken below a finite threshold of the δ-barrier area. In the proposed optical realization, the onset of PT symmetry breaking in the finite crystal corresponds to the lasing condition for the grating superstructures.

Graphene-based half-metal and spin-semiconductor for spintronic applications.

PubMed

Qi, Jingshan; Chen, Xiaofang; Hu, Kaige; Feng, Ji

2016-03-31

In this letter we propose a strategy to make graphene become a half-metal or spin-semiconductor by combining the magnetic proximity effects and sublattice symmetry breaking in graphone/graphene and graphone/graphene/BN heterostructures. Exchange interactions lift the spin degeneracy and sublattice symmetry breaking opens a band gap in graphene. More interestingly, the gap opening depends on the spin direction and the competition between the sublattice asymmetry and exchange field determines the system is a half-metal or a spin-semiconductor. By first-principles calculations and a low-energy effective model analysis, we elucidate the underlying physical mechanism of spin-dependent gap opening and spin degeneracy splitting. This offers an alternative practical platform for graphene-based spintronics.

Exploring the Universe with TV Remotes: Cooperative Quizzes via the Classroom Performance System (CPS) in AY101

NASA Astrophysics Data System (ADS)

Byrd, G.; Coleman, S.; Werneth, C.

2003-12-01

Our AY101 course has large enrollments. There are the usual attendance problems with students putting off studying until just before major exams, with predictable consequences. We (myself, faculty, Werneth, grad student, and Coleman, undergrad) describe our experience with one strategy to actively involve students: cooperatively answering quiz questions. We tried a solution during our May 2002 Interim term. Classes of three hours/day over three weeks make mid-class breaks essential! Before breaks, we presented a short multiple choice, open book/note quiz answered after break. Quizzes could increase grades, e.g. A- to an A, without excessively diluting importance of closed-book major exams. Comparing Interim 2002 final exams to Interim 2001, the average was 80%, much better than the 2001 class's 57%. The 2002 students interacted with one another more. Attendance was over 90%. During a regular semester, handing out and taking up papers would take up much time during the more frequent and larger classes. It's more interesting if students vote for different answers together then revealing the correct answer. Toward these ends, I obtained a grant for a "Classroom Performance System," a computer receiver unit, 128 ``TV remote" response pads and software for creating quizzes. Spring 2003, three teachers tried out the system in a trial fashion. To compare, we used the system during Interim 2003. Ease of giving quizzes and grading permitted a shorter 5 question quiz during break with another at class end totaling of 27 quizzes (almost one/day for a regular semester's Tuesday/Thursday class). Improvement was maintained with a slight 3 % increase. We used the CPS for events such as the recent Mars close approach. Kids of all ages like to check their understanding with a few questions. We created a web site where the students can interactively review questions and other materials, http://ay101.garnetsigma.com/index.html

The Link: Connecting Juvenile Justice and Child Welfare. Volume 6, Number 4, Spring 2008

ERIC Educational Resources Information Center

Shenk, Emily, Ed.; Price, Jennifer M., Ed.

2008-01-01

This issue of "The Link" newsletter contains the following articles: (1) Evidence-Based Practice: Developing a New Business Model from the Inside Out (Jeremy Kohomban, Paul Schiller, and Patricia O'Gorman); (2) The School to Prison Pipeline and Criminalizing Youth: Costs, Consequences, and Alternatives (Marsha Weissman); (3) Group Homes Appear…

Using a wood stove to heat greenhouses

Treesearch

Gloria Whitefeather-Spears

2009-01-01

The Red Lake Tribal Forestry Greenhouse in Red Lake, MN, utilizes four types of outdoor furnaces for heating through the fall, winter, and spring. The WoodMaster® is a highly efficient, wood-fired furnace that provides forced-air heat to the greenhouse. The HeatmorTM furnace is an economical wood-fired alternative that can provide lower...

Tree rings and the local environment

Treesearch

Kevin T. Smith

2011-01-01

The amount of wood produced by a tree each year depends on tree condition, genetic programming, and growing conditions. Wood is mature xylem, the result of inward cell divisions by the vascular cambium, the new cell generator located between the wood and the inner bark (phloem). In temperate climatic zones, where a spring and summer growing season alternates with...

Alternative Methods for the Awarding of College Credit: Credit by Examination for Articulated High School Courses. Adopted Spring 2013

ERIC Educational Resources Information Center

Academic Senate for California Community Colleges, 2013

2013-01-01

Colleges have long had mechanisms for awarding students credit for prior learning, from evaluating transcripts to establishing standards for the units and course credit to be associated with designated scores on nationally and internationally recognized curricula and exams. While the processes for awarding credit via these traditional mechanisms…

Analyzing the Reliability of the easyCBM Reading Comprehension Measures: Grade 5. Technical Report #1204

ERIC Educational Resources Information Center

Park, Bitnara Jasmine; Irvin, P. Shawn; Lai, Cheng-Fei; Alonzo, Julie; Tindal, Gerald

2012-01-01

In this technical report, we present the results of a reliability study of the fifth-grade multiple choice reading comprehension measures available on the easyCBM learning system conducted in the spring of 2011. Analyses include split-half reliability, alternate form reliability, person and item reliability as derived from Rasch analysis,…

Analyzing the Reliability of the easyCBM Reading Comprehension Measures: Grade 2. Technical Report #1201

ERIC Educational Resources Information Center

Lai, Cheng-Fei; Irvin, P. Shawn; Alonzo, Julie; Park, Bitnara Jasmine; Tindal, Gerald

2012-01-01

In this technical report, we present the results of a reliability study of the second-grade multiple choice reading comprehension measures available on the easyCBM learning system conducted in the spring of 2011. Analyses include split-half reliability, alternate form reliability, person and item reliability as derived from Rasch analysis,…

Analyzing the Reliability of the easyCBM Reading Comprehension Measures: Grade 4. Technical Report #1203

ERIC Educational Resources Information Center

Park, Bitnara Jasmine; Irvin, P. Shawn; Alonzo, Julie; Lai, Cheng-Fei; Tindal, Gerald

2012-01-01

In this technical report, we present the results of a reliability study of the fourth-grade multiple choice reading comprehension measures available on the easyCBM learning system conducted in the spring of 2011. Analyses include split-half reliability, alternate form reliability, person and item reliability as derived from Rasch analysis,…

Analyzing the Reliability of the easyCBM Reading Comprehension Measures: Grade 6. Technical Report #1205

ERIC Educational Resources Information Center

Irvin, P. Shawn; Alonzo, Julie; Park, Bitnara Jasmine; Lai, Cheng-Fei; Tindal, Gerald

2012-01-01

In this technical report, we present the results of a reliability study of the sixth-grade multiple choice reading comprehension measures available on the easyCBM learning system conducted in the spring of 2011. Analyses include split-half reliability, alternate form reliability, person and item reliability as derived from Rasch analysis,…

Analyzing the Reliability of the easyCBM Reading Comprehension Measures: Grade 7. Technical Report #1206

ERIC Educational Resources Information Center

Irvin, P. Shawn; Alonzo, Julie; Lai, Cheng-Fei; Park, Bitnara Jasmine; Tindal, Gerald

2012-01-01

In this technical report, we present the results of a reliability study of the seventh-grade multiple choice reading comprehension measures available on the easyCBM learning system conducted in the spring of 2011. Analyses include split-half reliability, alternate form reliability, person and item reliability as derived from Rasch analysis,…

Analyzing the Reliability of the easyCBM Reading Comprehension Measures: Grade 3. Technical Report #1202

ERIC Educational Resources Information Center

Lai, Cheng-Fei; Irvin, P. Shawn; Park, Bitnara Jasmine; Alonzo, Julie; Tindal, Gerald

2012-01-01

In this technical report, we present the results of a reliability study of the third-grade multiple choice reading comprehension measures available on the easyCBM learning system conducted in the spring of 2011. Analyses include split-half reliability, alternate form reliability, person and item reliability as derived from Rasch analysis,…

Recent Honey Bee Colony Declines

DTIC Science & Technology

2007-03-26

neonicotinoids, which contain the active ingredient imidacloprid , and similar other chemicals, such as clothianidin and thiamethoxam. Honey bees are...navigational and foraging abilities of honey bees.23 Concerns about imidacloprid , as CRS-9 24 Northwest Coalition for Alternatives to Pesticides... Imidacloprid , Fact Sheet,” Journal of Pesticide Reform, Spring 2001, at [http://www.moraybeekeepers.co.uk/imiacloprid]; Apiculteurs de France, “Composite

Comparing a Cognitive Model and Phototherapy in the Treatment of Seasonal Affective Disorder.

ERIC Educational Resources Information Center

Krantz, Sandra

Seasonal affective disorder (SAD) is characterized by recurrent major depression or bipolar disorder that occurs annually, usually later in fall as the daylight hours decrease, and that alternates with euthymic or hypomanic moods in the spring and summer. Pioneering research by Dr. Norman Rosenthal and associates has found phototherapy to be…

How fast is the Patagonian shelf-break acidifying?

NASA Astrophysics Data System (ADS)

Orselli, Iole B. M.; Kerr, Rodrigo; Ito, Rosane G.; Tavano, Virginia M.; Mendes, Carlos Rafael B.; Garcia, Carlos A. E.

2018-02-01

Anthropogenic carbon (Cant) concentration is determined according to the TrOCA method, from carbonate system data and hydrographic parameters collected during two consecutive spring cruises (2007 and 2008) in the Argentinean Patagonian shelf-break zone between 36°S and 50°S. Cant has intruded the water column until intermediate depths, with no Cant below 1000 m, in the deeper waters (i.e., North Atlantic Deep Water and Antarctic Bottom Water) of the Northern sector of the study area (i.e., North of 38°S). The higher Cant concentration is observed in Subantarctic Shelf Water in the Southern region, whereas in the Northern sector both Tropical Water and South Atlantic Central Water are equally affected by Cant intrusion. The Antarctic Intermediate Water represents the depth-limit achieved by Cant penetration, reinforcing the role that this water mass plays as an important vehicle to transport Cant to the oceans interior. The estimated Cant average (± method precision) is 46.6 ± 5.3 μmol kg- 1, considering the full depth of the water column. The ocean acidification state (ΔpH) shows an average (± standard deviation) of - 0.11 ± 0.05, thus, indicating an annual pH reduction of - 0.0010 yr- 1 since the Industrial Revolution (c.a. 1750). The degree of aragonite saturation is lowered towards undersaturation levels of calcite. The Patagonian shelf and shelf-break zones-a strong CO2 sink region in the global ocean-are likely a key area for Cant intrusion in the southwestern South Atlantic Ocean.

The timing and location of spawning for the Euphausiid Thysanoessa spinifera off the Oregon coast, USA

NASA Astrophysics Data System (ADS)

Feinberg, Leah R.; Peterson, William T.; Tracy Shaw, C.

2010-04-01

Thysanoessa spinifera eggs were sampled biweekly from 1997-2005 along a transect extending off the coast of Newport, OR, USA. T. spinifera eggs were typically found in greatest abundance at NH05, our shallower mid-shelf station, and in lowest abundance at NH25, our offshore, deep-water station beyond the shelf break. In most years small peaks in density of T. spinifera eggs were found in late winter (February-March) and/or spring (April-May) along with large, prolonged peaks in summer, from July-September. However, it was more common to find egg densities of <1 m -3 or to find no eggs at all (58-91% of sampling dates per year had densities <1 m -3 at NH05). We found that egg densities were significantly positively correlated with chlorophyll a concentrations during the winter and spring ( r2=0.52 and 0.55 respectively, p<0.001), but not during summer. We did not find a significant correlation between egg densities and female densities. When winters were stormy, as in 1998, 1999 and 2000 the first eggs of Thysanoessa spinifera were not observed at any station until after upwelling was initiated later in the spring. However, in other years eggs were likely to be found earlier in the year if there were fewer storms, or winter or spring upwelling events that were not followed by a large storm. In most years, spawning continued until the upwelling season ended in the autumn, however this trend ceased in 2003-2005 and spawning was interrupted earlier in the season. Overall, we found that chlorophyll a peaks and egg peaks increased in magnitude in the later part of our study. We have concluded that T. spinifera is likely an intermittent spawner, whose ovaries are not constantly mature and prepared for spawning, despite the presence of ocean conditions that are suitable for spawning.

Assessing satellite-derived start-of-season measures in the conterminous USA

USGS Publications Warehouse

Schwartz, Mark D.; Reed, Bradley C.; White, Michael A.

2002-01-01

National Oceanic and Atmospheric Administration (NOAA)-series satellites, carrying advanced very high-resolution radiometer (AVHRR) sensors, have allowed moderate resolution (1 km) measurements of the normalized difference vegetation index (NDVI) to be collected from the Earth's land surfaces for over 20 years. Across the conterminous USA, a readily accessible and decade-long data set is now available to study many aspects of vegetation activity in this region. One feature, the onset of deciduous plant growth at the start of the spring season (SOS) is of special interest, as it appears to be crucial for accurate computation of several important biospheric processes, and a sensitive measure of the impacts of global change. In this study, satellite-derived SOS dates produced by the delayed moving average (DMA) and seasonal midpoint NDVI (SMN) methods, and modelled surface phenology (spring indices, SI) were compared at widespread deciduous forest and mixed woodland sites during 1990–93 and 1995–99, and these three measures were also matched to native species bud-break data collected at the Harvard Forest (Massachusetts) over the same time period. The results show that both SOS methods are doing a modestly accurate job of tracking the general pattern of surface phenology, but highlight the temporal limitations of biweekly satellite data. Specifically, at deciduous forest sites: (1) SMN SOS dates are close in time to SI first bloom dates (average bias of +0.74 days), whereas DMA SOS dates are considerably earlier (average bias of −41.24 days) and also systematically earlier in late spring than in early spring; (2) SMN SOS tracks overall yearly trends in deciduous forests somewhat better than DMA SOS, but with larger average error (MAEs 8.64 days and 7.37 days respectively); and (3) error in both SOS techniques varies considerably by year. Copyright © 2002 Royal Meteorological Society.

Seasonal and annual variation in Chilean hake Merluccius gayi spawning locations and egg size off central Chile

NASA Astrophysics Data System (ADS)

Landaeta, Mauricio F.; Castro, Leonardo R.

2012-01-01

Variability in Chilean hake reproductive tactics off central Chile was assessed by analyzing ichthyoplankton samples from nine oceanographic cruises (1996-2005) and through experimental trials with early life stages (eggs, yolk-sac larvae) during the main (austral spring) and secondary (late summer-early autumn) spawning seasons. Abundant eggs in the plankton (1300-2000 eggs per 10 m 2) and historical adult reproductive data showed the highest reproductive activity in austral spring, with large egg aggregations near shelf break (50-100 m depth). Large, recently spawned eggs (1.15-1.20 mm diameter) were advected nearshore by coastward subsurface flows in the spring upwelling season. Experimental trials indicated that recently hatched larvae (3.4-3.5 mm) consumed their yolk-sac (0.17-0.41 mm 3) in 3-4 days at 10-12 °C; plankton sampling indicated that larval hake remained at mid-depth (50-100 m) without showing daily vertical migrations until completing their caudal fin formation (∼15 mm). During the secondary reproductive peak, hake spawned nearshore, when smaller eggs (0.95-1.13 mm) and recently hatched larvae (2.2-2.6 mm notochord length) occurred in surface waters (0-10 m depth). Their relatively large yolk-sac volumes (0.57 ± 0.11 mm 3) provided endogenous nourishment for at least 5 days at 10 °C, according to experiments. In the field, preflexion larvae occurred mainly in the mixed layer (0-25 m) and started ontogenetic daily vertical migrations at 7 mm. A strong decline occurred after 2002 in the adult Chilean hake biomass (estimated by hydroacoustic surveys) and body size, coinciding with variations in spawning locations (more coastward in early spring 2004 and 2005) and decline in egg size. Thus, recent variations in Chilean hake reproductive tactics may reflect an indirect effect of declines in the parental population size.

Diversity and Distribution Patterns of Cetaceans in the Subtropical Southwestern Atlantic Outer Continental Shelf and Slope

PubMed Central

Di Tullio, Juliana Couto; Gandra, Tiago B. R.; Zerbini, Alexandre N.; Secchi, Eduardo R.

2016-01-01

Temporal and spatial patterns of cetacean diversity and distribution were investigated through eight ship-based surveys carried out during spring and autumn between 2009 and 2014 on the outer continental shelf (~150m) and slope (1500m) off southeastern and southern Brazil (~23°S to ~34°S). The survey area was divided into southeast and south areas according to their oceanographic characteristics. Twenty-one species were observed in 503 sightings. The overall number of species was similar between the two areas, though it was higher in the spring in the south area. Five species were dominant and diversity varied more seasonally than spatially. ANOVA and kernel analyses showed that overall cetacean densities were higher in spring compared to autumn. Physeter macrocephalus, the most frequent species, concentrated throughout the south area at depths over 1000m in both seasons. Despite the overlapped occurrence at a broader scale, small delphinids presented latitudinal and in-offshore gradients as well as seasonal variation in distribution patterns, which could indicate habitat partitioning between some species. Delphinus delphis was only recorded in the south and its density decreased in areas where the presence of Stenella frontalis increased, mainly beyond the 250m isobath. Densities of S. longirostris and S. attenuata increased in lower latitudes and beyond the shelf break. The large delphinids Tursiops truncatus and Globicephala melas formed mixed groups in many occasions and were observed along the study area around depths of 500m. Grampus griseus was twice as frequent in the south area and densities increased in waters deeper than 600m. As expected, densities of both small and large migratory whales were higher during spring, over the continental slope, in the southeast area. The results presented here provided strong evidence on the importance of the outer continental shelf and slope to a diverse community of cetaceans occurring in the subtropical Southwestern Atlantic. PMID:27243455

Diversity and Distribution Patterns of Cetaceans in the Subtropical Southwestern Atlantic Outer Continental Shelf and Slope.

PubMed

Di Tullio, Juliana Couto; Gandra, Tiago B R; Zerbini, Alexandre N; Secchi, Eduardo R

2016-01-01

Temporal and spatial patterns of cetacean diversity and distribution were investigated through eight ship-based surveys carried out during spring and autumn between 2009 and 2014 on the outer continental shelf (~150m) and slope (1500m) off southeastern and southern Brazil (~23°S to ~34°S). The survey area was divided into southeast and south areas according to their oceanographic characteristics. Twenty-one species were observed in 503 sightings. The overall number of species was similar between the two areas, though it was higher in the spring in the south area. Five species were dominant and diversity varied more seasonally than spatially. ANOVA and kernel analyses showed that overall cetacean densities were higher in spring compared to autumn. Physeter macrocephalus, the most frequent species, concentrated throughout the south area at depths over 1000m in both seasons. Despite the overlapped occurrence at a broader scale, small delphinids presented latitudinal and in-offshore gradients as well as seasonal variation in distribution patterns, which could indicate habitat partitioning between some species. Delphinus delphis was only recorded in the south and its density decreased in areas where the presence of Stenella frontalis increased, mainly beyond the 250m isobath. Densities of S. longirostris and S. attenuata increased in lower latitudes and beyond the shelf break. The large delphinids Tursiops truncatus and Globicephala melas formed mixed groups in many occasions and were observed along the study area around depths of 500m. Grampus griseus was twice as frequent in the south area and densities increased in waters deeper than 600m. As expected, densities of both small and large migratory whales were higher during spring, over the continental slope, in the southeast area. The results presented here provided strong evidence on the importance of the outer continental shelf and slope to a diverse community of cetaceans occurring in the subtropical Southwestern Atlantic.

Understanding solute transport at catchment scales by using a synthesis of bottom-up and top-down modelling approaches

NASA Astrophysics Data System (ADS)

Selle, Benny; Schwientek, Marc; Osenbrück, Karsten

2013-04-01

The understanding of flow paths and travel times of water and solutes in catchments can be substantially improved by a combination of bottom-up and top-down modelling approaches. This hypothesis was tested for the 180 km² Ammer catchment in south-western Germany in which the landuse is dominated by agricultural and urban areas. The Ammer River with a mean discharge of 1 m³/s is mainly fed by springs from karstified and fractured aquifers. A limestone aquifer is extensively used for groundwater production. As a first step, we analysed measured concentrations of major ions, selected organic micro-pollutants and environmental tracers for surface water, springs and deep groundwater from wells using typical top-down approaches such as principal component analysis and lumped parameter models. From these approaches, we gained an initial understanding of water and solute fluxes in the catchment. The initial hypotheses on subsurface flow paths and travel times were subsequently tested using a numerical, 3-D groundwater model as a typical bottom-up approach. Our synthesis of top-down and bottom-up approaches provided us with a reliable picture of the dominant processes governing water and solute fluxes in the Ammer catchment. Several spring waters indicated mixing with wastewater. These contaminations were indentified to be caused by either recharge of surface water or leaky sewer systems. Deep percolation below the plant root zone polluted with agrochemicals was found to affect most springs and surface waters resulting in nitrate concentrations of approximately 30 mg/l. This process also influenced some of the drinking-water wells, although water quality for most of these wells is still relatively high due to some attenuation of pollutants but - above all - due to a significant proportion of groundwater with ages > 50 years. However, water quality will likely decrease if contaminants break through and/or conditions for microbiological attenuation process will deteriorate, for example due to depletion of suitable electron donors.

Early Spring Phytoplankton Dynamics in the Western Antarctic Peninsula

NASA Astrophysics Data System (ADS)

Arrigo, Kevin R.; van Dijken, Gert L.; Alderkamp, Anne-Carlijn; Erickson, Zachary K.; Lewis, Kate M.; Lowry, Kate E.; Joy-Warren, Hannah L.; Middag, Rob; Nash-Arrigo, Janice E.; Selz, Virginia; van de Poll, Willem

2017-12-01

The Palmer Long-Term Ecological Research program has sampled waters of the western Antarctic Peninsula (wAP) annually each summer since 1990. However, information about the wAP prior to the peak of the phytoplankton bloom in January is sparse. Here we present results from a spring process cruise that sampled the wAP in the early stages of phytoplankton bloom development in 2014. Sea ice concentrations were high on the shelf relative to nonshelf waters, especially toward the south. Macronutrients were high and nonlimiting to phytoplankton growth in both shelf and nonshelf waters, while dissolved iron concentrations were high only on the shelf. Phytoplankton were in good physiological condition throughout the wAP, although biomass on the shelf was uniformly low, presumably because of heavy sea ice cover. In contrast, an early stage phytoplankton bloom was observed beneath variable sea ice cover just seaward of the shelf break. Chlorophyll a concentrations in the bloom reached 2 mg m-3 within a 100-150 km band between the SBACC and SACCF. The location of the bloom appeared to be controlled by a balance between enhanced vertical mixing at the position of the two fronts and increased stratification due to melting sea ice between them. Unlike summer, when diatoms overwhelmingly dominate the phytoplankton population of the wAP, the haptophyte Phaeocystis antarctica dominated in spring, although diatoms were common. These results suggest that factors controlling phytoplankton abundance and composition change seasonally and may differentially affect phytoplankton populations as environmental conditions within the wAP region continue to change.

Calculation of total free energy yield as an alternative approach for predicting the importance of potential chemolithotrophic reactions in geothermal springs.

PubMed

Dodsworth, Jeremy A; McDonald, Austin I; Hedlund, Brian P

2012-08-01

To inform hypotheses regarding the relative importance of chemolithotrophic metabolisms in geothermal environments, we calculated free energy yields of 26 chemical reactions potentially supporting chemolithotrophy in two US Great Basin hot springs, taking into account the effects of changing reactant and product activities on the Gibbs free energy as each reaction progressed. Results ranged from 1.2 × 10(-5) to 3.6 J kg(-1) spring water, or 3.7 × 10(-5) to 11.5 J s(-1) based on measured flow rates, with aerobic oxidation of CH(4) or NH4 + giving the highest average yields. Energy yields calculated without constraining pH were similar to those at constant pH except for reactions where H(+) was consumed, which often had significantly lower yields when pH was unconstrained. In contrast to the commonly used normalization of reaction chemical affinities per mole of electrons transferred, reaction energy yields for a given oxidant varied by several orders of magnitude and were more sensitive to differences in the activities of products and reactants. The high energy yield of aerobic ammonia oxidation is consistent with previous observations of significant ammonia oxidation rates and abundant ammonia-oxidizing archaea in sediments of these springs. This approach offers an additional lens through which to view the thermodynamic landscape of geothermal springs. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Stable isotope and noble gas constraints on the source and residence time of spring water from the Table Mountain Group Aquifer, Paarl, South Africa and implications for large scale abstraction

NASA Astrophysics Data System (ADS)

Miller, J. A.; Dunford, A. J.; Swana, K. A.; Palcsu, L.; Butler, M.; Clarke, C. E.

2017-08-01

Large scale groundwater abstraction is increasingly being used to support large urban centres especially in areas of low rainfall but presents particular challenges in the management and sustainability of the groundwater system. The Table Mountain Group (TMG) Aquifer is one of the largest and most important aquifer systems in South Africa and is currently being considered as an alternative source of potable water for the City of Cape Town, a metropolis of over four million people. The TMG aquifer is a fractured rock aquifer hosted primarily in super mature sandstones, quartzites and quartz arenites. The groundwater naturally emanates from numerous springs throughout the cape region. One set of springs were examined to assess the source and residence time of the spring water. Oxygen and hydrogen isotopes indicate that the spring water has not been subject to evaporation and in combination with Na/Cl ratios implies that recharge to the spring systems is via coastal precipitation. Although rainfall in the Cape is usually modelled on orographic rainfall, δ18O and δ2H values of some rainfall samples are strongly positive indicating a stratiform component as well. Comparing the spring water δ18O and δ2H values with that of local rainfall, indicates that the springs are likely derived from continuous bulk recharge over the immediate hinterland to the springs and not through large and/or heavy downpours. Noble gas concentrations, combined with tritium and radiocarbon activities indicate that the residence time of the TMG groundwater in this area is decadal in age with a probable maximum upper limit of ∼40 years. This residence time is probably a reflection of the slow flow rate through the fractured rock aquifer and hence indicates that the interconnectedness of the fractures is the most important factor controlling groundwater flow. The short residence time of the groundwater suggest that recharge to the springs and the Table Mountain Group Aquifer as a whole is vulnerable to climate change and reductions in regional precipitation. Any plans for large scale abstraction to supplement the City of Cape Town water supply would need to factor this into models of maximum sustainable yield.

Exposure to nature versus relaxation during lunch breaks and recovery from work: development and design of an intervention study to improve workers' health, well-being, work performance and creativity.

PubMed

de Bloom, Jessica; Kinnunen, Ulla; Korpela, Kalevi

2014-05-22

The objective of this research project is to understand and to improve workers' recovery from work stress. Although recovery during lunch breaks is the most common within-workday break, it has received only minor research attention. Therefore, we will study whether lunch breaks including a relaxation session or exposure to nature have more favorable outcomes than usually spent lunch breaks concerning: a) recovery processes, b) health, c) well-being, d) job performance and e) creativity. We approach recovery by combining the theoretical frameworks of work and environmental psychology. We conduct an intervention study in a sample of 268 knowledge-workers who engage in different lunch break activities for 15-minutes per day, two weeks in a row. We randomly assign participants to three experimental conditions: 1) exposure to nature, 2) relaxation and 3) control group (lunch break spent as usual). Online questionnaires before and after the intervention assess long term changes regarding recovery processes and the major outcome variables. Before, during and after the intervention, SMS and paper-pencil questionnaires measure the same constructs four times a day with fewer items. We also measure blood pressure and collect saliva samples to map cortisol excretion across the intervention period. A timed experimental task (i.e., the Alternative Uses Task) is used to examine differences in creativity between the three groups after the intervention period. By combining the knowledge of work and environmental psychology about recovery and restorative experiences, by merging three recovery perspectives (settings, processes, and outcomes) and by using data triangulation, we produce valid results that broaden our view on mechanisms underlying recovery and enhance our understanding about their links to psychological, behavioural and physiological outcomes, resulting in a more comprehensive picture of work stress recovery in general. ClinicalTrials.gov Protocol Registration System NCT02124837. Registered 24 April 2014.

Exposure to nature versus relaxation during lunch breaks and recovery from work: development and design of an intervention study to improve workers’ health, well-being, work performance and creativity

PubMed Central

2014-01-01

Background The objective of this research project is to understand and to improve workers’ recovery from work stress. Although recovery during lunch breaks is the most common within-workday break, it has received only minor research attention. Therefore, we will study whether lunch breaks including a relaxation session or exposure to nature have more favorable outcomes than usually spent lunch breaks concerning: a) recovery processes, b) health, c) well-being, d) job performance and e) creativity. We approach recovery by combining the theoretical frameworks of work and environmental psychology. Methods/Design We conduct an intervention study in a sample of 268 knowledge-workers who engage in different lunch break activities for 15-minutes per day, two weeks in a row. We randomly assign participants to three experimental conditions: 1) exposure to nature, 2) relaxation and 3) control group (lunch break spent as usual). Online questionnaires before and after the intervention assess long term changes regarding recovery processes and the major outcome variables. Before, during and after the intervention, SMS and paper-pencil questionnaires measure the same constructs four times a day with fewer items. We also measure blood pressure and collect saliva samples to map cortisol excretion across the intervention period. A timed experimental task (i.e., the Alternative Uses Task) is used to examine differences in creativity between the three groups after the intervention period. Discussion By combining the knowledge of work and environmental psychology about recovery and restorative experiences, by merging three recovery perspectives (settings, processes, and outcomes) and by using data triangulation, we produce valid results that broaden our view on mechanisms underlying recovery and enhance our understanding about their links to psychological, behavioural and physiological outcomes, resulting in a more comprehensive picture of work stress recovery in general. Trial registration ClinicalTrials.gov Protocol Registration System NCT02124837. Registered 24 April 2014. PMID:24885178

Spring onset variations and trends in the continental United States: past and regional assessment using temperature-based indices

USGS Publications Warehouse

Schwartz, Mark D.; Ault, Toby R.; Betancourt, Julio L.

2012-01-01

Phenological data are simple yet sensitive indicators of climate change impacts on ecosystems, but observations have not been made routinely or extensively enough to evaluate spatial and temporal patterns across most continents, including North America. As an alternative, many studies use weather-based algorithms to simulate specific phenological responses. Spring Indices (SI) are a set of complex phenological models that have been successfully applied to evaluate variations and trends in the onset of spring across the Northern Hemisphere’s temperate regions. To date, SI models have been limited by only producing output in locations where both the plants’ chilling and warmth requirements are met. Here, we develop an extended form of the SI (abbreviated SI-x) that expands their application into the subtropics by ignoring chilling requirements while still retaining the utility and accuracy of the original SI (now abbreviated SI-o). The validity of the new indices is tested, and regional SI anomalies are explored across the data-rich continental United States. SI-x variations from 1900 to 2010 show an abrupt and sustained delay in spring onset of about 4–8 d (around 1958) in parts of the Southeast and southern Great Plains, and a comparable advance of 4–8 d (around 1984) in parts of the northern Great Plains and the West. Atmospheric circulation anomalies, linked to large-scale modes of variability, exert modest but significant roles in the timing of spring onset across the United States on interannual and longer timescales. The SI-x are promising metrics for tracking spring onset variations and trends in mid-latitudes, relating them to relevant ecological, hydrological, and socioeconomic phenomena, and exploring connections between atmospheric drivers and seasonal timing.

The impact of winter and spring temperatures on temperate tree budburst dates: results from an experimental climate manipulation.

PubMed

Fu, Yongshuo H; Campioli, Matteo; Deckmyn, Gaby; Janssens, Ivan A

2012-01-01

Budburst phenology is a key driver of ecosystem structure and functioning, and it is sensitive to global change. Both cold winter temperatures (chilling) and spring warming (forcing) are important for budburst. Future climate warming is expected to have a contrasting effect on chilling and forcing, and subsequently to have a non-linear effect on budburst timing. To clarify the different effects of warming during chilling and forcing phases of budburst phenology in deciduous trees, (i) we conducted a temperature manipulation experiment, with separate winter and spring warming treatments on well irrigated and fertilized saplings of beech, birch and oak, and (ii) we analyzed the observations with five temperature-based budburst models (Thermal Time model, Parallel model, Sequential model, Alternating model, and Unified model). The results show that both winter warming and spring warming significantly advanced budburst date, with the combination of winter plus spring warming accelerating budburst most. As expected, all three species were more sensitive to spring warming than to winter warming. Although the different chilling requirement, the warming sensitivity was not significantly different among the studied species. Model evaluation showed that both one- and two- phase models (without and with chilling, respectively) are able to accurately predict budburst. For beech, the Sequential model reproduced budburst dates best. For oak and birch, both Sequential model and the Thermal Time model yielded good fit with the data but the latter was slightly better in case of high parameter uncertainty. However, for late-flushing species, the Sequential model is likely be the most appropriate to predict budburst data in a future warmer climate.

Foraging habitat for shorebirds in southeastern Missouri and its predicted future availability

USGS Publications Warehouse

Twedt, Daniel J.

2013-01-01

Water management to protect agriculture in alluvial floodplains often conflicts with wildlife use of seasonal floodwater. Such is the case along the Mississippi River in southeastern Missouri where migrating shorebirds forage in shallow-flooded fields. I estimated the current availability of habitat for foraging shorebirds within the New Madrid and St. Johns Basins based on daily river elevations (1943–2009), under assumptions that shorebirds forage in open habitat with water depth <15 cm and use mudflats for 3 days after exposure. The area of shorebird foraging habitat, based on replicated 50-year random samples, averaged 975 ha per day during spring and 33 ha per day during fall. Adjustments to account for habitat quality associated with different water depths, duration of mudflat exposure, intra-seasonal availability, and state of agricultural crops, indicated the equivalent of 494 ha daily of optimal habitat during spring and 11 ha during fall. Proposed levees and pumps to protect cropland would reduce shorebird foraging habitat by 80 %: to 211 ha (108 optimal ha) per day during spring and 9 ha (<3 optimal ha) per day during fall. Alternative water management that allows natural flooding below a prescribed elevation would retain nearly all existing shorebird foraging habitat during fall and about 60 % of extant habitat during spring.

A comprehensive draft genome sequence for lupin (Lupinus angustifolius), an emerging health food: Insights into plant-microbe interactions and legume evolution

USDA-ARS?s Scientific Manuscript database

Lupins are important grain legume crops that form a critical part of sustainable farming systems, by reducing the need for fertilizer and providing disease breaks. Narrow-leafed lupin (Lupinus angustifolius L.) is gaining popularity as a human health food, as a non-GM alternative to soybean with the...

The Museum as a Catalyst for Education and Citizenship: Breaking Barriers in Rio de Janeiro

ERIC Educational Resources Information Center

Bottrel Tostes, Vera Lucia

2011-01-01

Brazil's National History Museum in Rio de Janeiro is reaching out to the most marginalized young people and establishing itself as an important partner in offering them alternatives to a life of crime and addiction. The target population for its programs includes disenfranchised children and young people aged 10 to 20--those living in the…

The Space of Pedagogic Imaginary: The Interstice of Teacher's Intent and Students' Learning

ERIC Educational Resources Information Center

Doerr, Neriko Musha

2016-01-01

How do we make of students learning something their teacher did not intend to teach? Researchers suggest it unnecessary extras, learning of implicit rules of the game, or keys to understand power structure. Based on an ethnographic fieldwork of a college alternative break trip to learn about poverty through simulation, this article suggests such…

Dark Energy, or Worse

ScienceCinema

Carroll, Sean

2018-01-09

General relativity is inconsistent with cosmological observations unless we invoke components of dark matter and dark energy that dominate the universe. While it seems likely that these exotic substances really do exist, the alternative is worth considering: that Einstein's general relativity breaks down on cosmological scales. I will discuss models of modified gravity, tests in the solar system and elsewhere, and consequences for cosmology.

Social Studies Now!: Put Storybook Characters on Trial to Spark Students' Interest in the Justice System.

ERIC Educational Resources Information Center

Lindquist, Tarry

1998-01-01

This social studies activity helps primary students understand the trial process by putting literary characters on trial (e.g., Goldilocks for breaking and entering or Cruella DeVille for stealing dalmatians). Alternatively, students can try real-life problems such as bullying on the playground. Through role playing, students learn how the justice…

Break-even analysis revisited: the need to adjust for profitability, the collection rate and autonomous income.

PubMed

Broyles, R W; Narine, L; Khaliq, A

2003-08-01

This paper modifies traditional break-even analysis and develops a model that reflects the influence of variation in payer mix, the collection rate, profitability and autonomous income on the desired volume alternative. The augmented model indicates that a failure to adjust for uncollectibles and the net surplus results in a systematic understatement of the desired volume alternative. Conversely, a failure to adjust for autonomous income derived from the operation of cafeterias, gift shops or an organization's investment in marketable securities produces an overstatement of the desired volume. In addition, this paper uses Microsoft Excel to develop a spreadsheet that constructs a pro forma income statement, expressed in terms of the contribution margin. The spreadsheet also relies on the percentage of sales or revenue approach to prepare a balance sheet from which indicators of fiscal performance are calculated. Hence, the analysis enables the organization to perform a sensitivity analysis of potential changes in the desired volume, the operating margin, the current ratio, the debt: equity ratio and the amount of cash derived from operations that are associated with expected variation in payer mix, the collection rate, grouped by payer, the net surplus and autonomous income.

Alternative Lengthening of Telomeres Mediated by Mitotic DNA Synthesis Engages Break-Induced Replication Processes

PubMed Central

Min, Jaewon; Wright, Woodring E.

2017-01-01

ABSTRACT Alternative lengthening of telomeres (ALT) is a telomerase-independent telomere maintenance mechanism that occurs in a subset of cancers. By analyzing telomerase-positive cells and their human TERC knockout-derived ALT human cell lines, we show that ALT cells harbor more fragile telomeres representing telomere replication problems. ALT-associated replication defects trigger mitotic DNA synthesis (MiDAS) at telomeres in a RAD52-dependent, but RAD51-independent, manner. Telomeric MiDAS is a conservative DNA synthesis process, potentially mediated by break-induced replication, similar to type II ALT survivors in Saccharomyces cerevisiae. Replication stresses induced by ectopic oncogenic expression of cyclin E, G-quadruplexes, or R-loop formation facilitate the ALT pathway and lead to telomere clustering, a hallmark of ALT cancers. The TIMELESS/TIPIN complex suppresses telomere clustering and telomeric MiDAS, whereas the SMC5/6 complex promotes them. In summary, ALT cells exhibit more telomere replication defects that result in persistent DNA damage responses at telomeres, leading to the engagement of telomeric MiDAS (spontaneous mitotic telomere synthesis) that is triggered by DNA replication stress, a potential driver of genomic duplications in cancer. PMID:28760773

Apogean-perigean signals encoded in tidal flats at the fluvio-estuarine transition of Glacier Creek, Turnagain Arm, Alaska; implications for ancient tidal rhythmites

USGS Publications Warehouse

Greb, S.F.; Archer, A.W.; Deboer, D.G.

2011-01-01

Turnagain Arm is a macrotidal fjord-style estuary. Glacier Creek is a small, glacially fed stream which enters the estuary tangentially near Girdwood, Alaska. Trenches and daily sedimentation measurements were made in a mudflat along the fluvio-estuarine transition of Glacier Creek during several summers since 2003. Each year, the flats appear to erode during the winter and then accrete vertically in the spring and summer. In each of the years studied, tidal laminae in vertically thickening and thinning laminae bundles were deposited by twice daily tides in neap-spring tidal cycles. In 2004, bundles of thickening and thinning laminae couplets were noted in trenches cut into the flats. Five laminae bundles alternated between thicker and thinner bundles, corresponding to the perigean (high spring) and apogean (low spring) tides. Well-preserved apogean-perigean cycles have rarely been documented in modern tidal flat sediments. At this location, vertical accretion of tidal rhythmites with well-developed neap-spring cyclicity is possible because of the near-complete removal of the flat from the previous year, which creates accommodation space for vertical accretion without significant reworking. Macrotidal conditions, no reworking by infaunal invertebrates, protection from the main tidal channel by a gravel bar and protection from storm waves and fluvial erosion by a recess in the sedge marsh that surrounds the flats all aid in preservation of rhythmites during aggradation. The position of the flats relative to tidal range allows for accumulation of complete spring cycles and incomplete neap cycles. In the summer of 2004, apogee and perigee were closely aligned with the new and full moons, resulting in successive strong perigee and apogee tides which probably aided in the accumulation of successive thick-thin spring cycles encoding the apogean and perigean tidal cycle. The apogean-perigean signal was not observed in subsequent years. ?? 2011 The Authors.

Effects of gypsy moth-oriented silvicultural treatments on vertebrate predator communities

Treesearch

Richard D. Greer; Robert C. Whitmore

1991-01-01

The impact of forest thinning, as an alternative gypsy moth management technique, on insectivorous birds and small mammals is being investigated in the West Virginia University Forest. The effects of thinning on predation of gypsy moth larvae and pupae by vertebrates are also being examined. Pre-thinning studies were conducted during the spring, summer, and fall of...

Agile Port and High Speed Ship Technologies

DTIC Science & Technology

2009-12-31

Alternative Shipboard Powering Systems for Naval and Regulatory Review • The Evaluation and Implementation Plan for Southern California Maglev ...Ackerman". CSULB Foundation Annual Report. CSULB Foundation, Long Beach, CA. December 2005. " Maglev Technology ’Conveys’ Port Transportation Solutions...34. Newsflash. College of Engineering, California State University, Long Beach. Cover page. Spring 2006 Hanson, Kristopher. "Engineers Tout Maglev at

Air Force Energy Program Policy Memorandum

DTIC Science & Technology

2009-06-16

Critical Asset Prioritization Methodology ( CAPM ) tool Manage costs. 3.4.2.5. Metrics Percentage of alternative/renewable fuel used for aviation fuel...supporting critical assets residing on military installations Field the Critical Asset Prioritization Methodology ( CAPM ) tool by Spring 2008. This CAPM ...Increase the number of flexible fuel systems • Identify/develop privately financed/operated energy production on Air Bases • Field the Critical

Alternative Estimates of the Reliability of College Grade Point Averages. Professional File. Article 130, Spring 2013

ERIC Educational Resources Information Center

Saupe, Joe L.; Eimers, Mardy T.

2013-01-01

The purpose of this paper is to explore differences in the reliabilities of cumulative college grade point averages (GPAs), estimated for unweighted and weighted, one-semester, 1-year, 2-year, and 4-year GPAs. Using cumulative GPAs for a freshman class at a major university, we estimate internal consistency (coefficient alpha) reliabilities for…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kornfeldt, H.; Bjoerk, K.O.; Ekstroem, P.

The protection against dynamic effects in connection with potential pipe breaks has been implemented in different ways in the development of BWR reactor designs. First-generation plant designs reflect code requirements in effect at that time which means that no piping restraint systems were designed and built into those plants. Modern designs have, in contrast, implemented full protection against damage in connection with postulated pipe breaks, as required in current codes and regulations. Moderns standards and current regulatory demands can be met for the older plants by backfitting pipe whip restraint hardware. This could lead to several practical difficulties as thesemore » installations were not anticipated in the original plant design and layout. Meeting the new demands by analysis would in this situation have great advantages. Application of leak-before-break criteria gives an alternative opportunity of meeting modem standards in reactor safety design. Analysis takes into account data specific to BWR primary system operation, actual pipe material properties, piping loads and leak detection capability. Special attention must be given to ensure that the data used reflects actual plant conditions.« less

Design of a resistive exercise device for use on the Space Shuttle

NASA Technical Reports Server (NTRS)

Carlson, Dennis L.; Durrani, Mohammed; Redilla, Christi L.

1992-01-01

The National Aeronautics and Space Administration in conjunction with the Universities Space Research Association sponsored the design of a Resistive Exercise Device (RED) for use on the Space Shuttle. The device must enable the astronauts to perform a number of exercises to prevent skeletal muscle atrophy and neuromuscular deconditioning in microgravity environments. The RED must fit the requirements for limited volume and weight and must provide a means of restraint during exercise. The design team divided the functions of the device into three major groups: methods of supplying force, methods of adjusting force, and methods of transmitting the force to the user. After analyzing the three main functions of the RED and developing alternatives for each, the design team used a comparative decision process to choose the most feasible components for the overall design. The design team selected the constant force spring alternative for further embodiment. The device consists of an array of different sized constant force springs which can be pinned in different combinations to produce the required output forces. The force is transmitted by means of a shaft and gear system. The final report is divided into four sections. An introduction section discusses the sponsor background, problem background and requirements of the device. The second section covers the alternative designs for each of the main functions. The design solution and pertinent calculations comprises the third section. The final section contains design conclusions and recommendations including topics of future work.

Dark Gauge U(1) symmetry for an alternative left-right model

NASA Astrophysics Data System (ADS)

Kownacki, Corey; Ma, Ernest; Pollard, Nicholas; Popov, Oleg; Zakeri, Mohammadreza

2018-02-01

An alternative left-right model of quarks and leptons, where the SU(2)_R lepton doublet (ν ,l)_R is replaced with (n,l)_R so that n_R is not the Dirac mass partner of ν _L, has been known since 1987. Previous versions assumed a global U(1)_S symmetry to allow n to be identified as a dark-matter fermion. We propose here a gauge extension by the addition of extra fermions to render the model free of gauge anomalies, and just one singlet scalar to break U(1)_S. This results in two layers of dark matter, one hidden behind the other.

Integrated agricultural energy system

NASA Astrophysics Data System (ADS)

Taylor, R. M.

1985-08-01

The purpose of this program is to show New England farmers and other New England energy users how they can use alternative energy sources to reduce their energy cost and dependency on conventional sources. The project demonstrates alternative energy technologies in solar, alcohol and methane. Dissemination is planned through tours to be conducted by the Worcester County Extension Service. Most of these goals were completed as planned. A few things have yet to be completed. The solar panels and solar hot water tanks have to be installed. The fermenter's agitating and cooling system have to be secured inside the fermenter. Once these items are complete tours will begin early in the spring.

Crowder College MARET Center Facility Final Scientific/Technical Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rand, Amy

This project was a research facility construction project and did not include actual research. The new facility will benefit the public by providing training opportunities for students, as well as incubator and laboratory space for entrepreneurs in the areas of alternative and renewable energies. The 9,216 -square-foot Missouri Alternative and Renewable Energy Technology (MARET) Center was completed in late 2011. Classes in the MARET Center began in the spring 2012 semester. Crowder College takes pride in the MARET Center, a focal point of the campus, as the cutting edge in education, applied research and commercial development in the growing fieldmore » of green technology.« less

Breaking Tolerance to Thyroid Antigens: Changing Concepts in Thyroid Autoimmunity

PubMed Central

Rapoport, Basil

2014-01-01

Thyroid autoimmunity involves loss of tolerance to thyroid proteins in genetically susceptible individuals in association with environmental factors. In central tolerance, intrathymic autoantigen presentation deletes immature T cells with high affinity for autoantigen-derived peptides. Regulatory T cells provide an alternative mechanism to silence autoimmune T cells in the periphery. The TSH receptor (TSHR), thyroid peroxidase (TPO), and thyroglobulin (Tg) have unusual properties (“immunogenicity”) that contribute to breaking tolerance, including size, abundance, membrane association, glycosylation, and polymorphisms. Insight into loss of tolerance to thyroid proteins comes from spontaneous and induced animal models: 1) intrathymic expression controls self-tolerance to the TSHR, not TPO or Tg; 2) regulatory T cells are not involved in TSHR self-tolerance and instead control the balance between Graves' disease and thyroiditis; 3) breaking TSHR tolerance involves contributions from major histocompatibility complex molecules (humans and induced mouse models), TSHR polymorphism(s) (humans), and alternative splicing (mice); 4) loss of tolerance to Tg before TPO indicates that greater Tg immunogenicity vs TPO dominates central tolerance expectations; 5) tolerance is induced by thyroid autoantigen administration before autoimmunity is established; 6) interferon-α therapy for hepatitis C infection enhances thyroid autoimmunity in patients with intact immunity; Graves' disease developing after T-cell depletion reflects reconstitution autoimmunity; and 7) most environmental factors (including excess iodine) “reveal,” but do not induce, thyroid autoimmunity. Micro-organisms likely exert their effects via bystander stimulation. Finally, no single mechanism explains the loss of tolerance to thyroid proteins. The goal of inducing self-tolerance to prevent autoimmune thyroid disease will require accurate prediction of at-risk individuals together with an antigen-specific, not blanket, therapeutic approach. PMID:24091783

The Assessment of Service through the Lens of Social Change Leadership: A Phenomenological Approach

ERIC Educational Resources Information Center

Buschlen, Eric Lee; Reusch, Jonathan

2016-01-01

Service to others plays a key role in the development of one's worldview. To study this key role, authors examined a sample of 38 student narratives in three phases: before, during, and 45 days after they served at an alternative break site around the United States. Students kept a prompt-based journal inspired by the tenets of the social change…

New Perspectives on Active Tectonics: Observing Fault Motion, Mapping Earthquake Strain Fields, and Visualizing Seismic Events in Multiple Dimensions Using Satellite Imagery and Geophysical Data Base

NASA Technical Reports Server (NTRS)

Crippen, R.; Blom, R.

1994-01-01

By rapidly alternating displays of SPOT satellite images acquired on 27 July 1991 and 25 July 1992 we are able to see spatial details of terrain movements along fault breaks associated with the 28 June 1992 Landers, California earthquake that are virtually undetectable by any other means.

Mixing to Monsoons: Air-Sea Interactions in the Bay of Bengal

NASA Astrophysics Data System (ADS)

Lucas, A. J.; Shroyer, E. L.; Wijesekera, H. W.; Fernando, H. J. S.; D'Asaro, E.; Ravichandran, M.; Jinadasa, S. U. P.; MacKinnon, J. A.; Nash, J. D.; Sharma, R.; Centurioni, L.; Farrar, J. T.; Weller, R.; Pinkel, R.; Mahadevan, A.; Sengupta, D.; Tandon, A.

2014-07-01

More than 1 billion people depend on rainfall from the South Asian monsoon for their livelihoods. Summertime monsoonal precipitation is highly variable on intraseasonal time scales, with alternating "active" and "break" periods. These intraseasonal oscillations in large-scale atmospheric convection and winds are closely tied to 1°C-2°C variations of sea surface temperature in the Bay of Bengal.

Feed-forward motor control of ultrafast, ballistic movements.

PubMed

Kagaya, K; Patek, S N

2016-02-01

To circumvent the limits of muscle, ultrafast movements achieve high power through the use of springs and latches. The time scale of these movements is too short for control through typical neuromuscular mechanisms, thus ultrafast movements are either invariant or controlled prior to movement. We tested whether mantis shrimp (Stomatopoda: Neogonodactylus bredini) vary their ultrafast smashing strikes and, if so, how this control is achieved prior to movement. We collected high-speed images of strike mechanics and electromyograms of the extensor and flexor muscles that control spring compression and latch release. During spring compression, lateral extensor and flexor units were co-activated. The strike initiated several milliseconds after the flexor units ceased, suggesting that flexor activity prevents spring release and determines the timing of strike initiation. We used linear mixed models and Akaike's information criterion to serially evaluate multiple hypotheses for control mechanisms. We found that variation in spring compression and strike angular velocity were statistically explained by spike activity of the extensor muscle. The results show that mantis shrimp can generate kinematically variable strikes and that their kinematics can be changed through adjustments to motor activity prior to the movement, thus supporting an upstream, central-nervous-system-based control of ultrafast movement. Based on these and other findings, we present a shishiodoshi model that illustrates alternative models of control in biological ballistic systems. The discovery of feed-forward control in mantis shrimp sets the stage for the assessment of targets, strategic variation in kinematics and the role of learning in ultrafast animals. © 2016. Published by The Company of Biologists Ltd.

Characterization of Ni19.5Ti50.5Pd25Pt5 High-Temperature Shape Memory Alloy Springs and their Potential Application in Aeronautics

NASA Technical Reports Server (NTRS)

Stebner, Aaron; Padula, Santo A.; Noebe, Ronald D.

2008-01-01

Shape memory alloys (SMAs) have been used as actuators in many different industries since the discovery of the shape memory effect, but the use of SMAs as actuation devices in aeronautics has been limited due to the temperature constraints of commercially available materials. Consequently, work is being done at NASA's Glenn Research Center to develop new SMAs capable of being used in high temperature environments. One of the more promising high-temperature shape memory alloys (HTSMAs) is Ni19.5Ti50.5Pd25Pt5. Recent work has shown that this material is capable of being used in operating environments of up to 250 C. This material has been shown to have very useful actuation capabilities, demonstrating repeatable strain recoveries up to 2.5% in the presence of an externally applied load. Based on these findings, further work has been initiated to explore potential applications and alternative forms of this alloy, such as springs. Thus, characterization of Ni19.5Ti50.5Pd25Pt5 springs, including their mechanical response and how variations in this response correlate to changes in geometric parameters, are discussed. The effects of loading history, or training, on spring behavior were also investigated. A comparison of the springs with wire actuators is made and the benefits of using one actuator form as opposed to the other discussed. These findings are used to discuss design considerations for a surge-control mechanism that could be used in the centrifugal compressor of a T-700 helicopter engine.

A nonlinear stretching based electromagnetic energy harvester on FR4 for wideband operation

NASA Astrophysics Data System (ADS)

Mallick, Dhiman; Amann, Andreas; Roy, Saibal

2015-01-01

We report a nonlinear stretching-based electromagnetic energy harvester using FR4 as a vibrating spring material due to its low Young’s modulus. We show analytically that the nonlinearity is caused by the stretching, in addition to the bending, of the specially designed spring arms; this gives rise to a wider half-power bandwidth of 10 Hz at 1 g acceleration, which is almost 5 times higher than that of a comparable linear counterpart. The output spectra show the first reported experimental evidence of a symmetry broken nonlinear secondary peak in a single potential well system at frequencies close to the nonlinear jump frequency, which may appear to be due to the dynamic symmetry breaking of the oscillator or to the inherent asymmetry of the built prototype. The presence of this secondary peak is useful in generating a significant amount of power compared to the symmetric states, producing ˜3 times more power at the secondary peak than the nearby symmetric states. 110% of the peak power obtained for 0.5 g acceleration is achieved at the secondary peak during the frequency up-sweep. The experimental results are compared with a deterministic numerical model based on the Duffing oscillator, and we include a qualitative discussion on the influence of noise in an experimental energy harvesting system.

Seasonal and spatial variabilities in northern Gulf of Alaska surface water iron concentrations driven by shelf sediment resuspension, glacial meltwater, a Yakutat eddy, and dust

NASA Astrophysics Data System (ADS)

Crusius, John; Schroth, Andrew W.; Resing, Joseph A.; Cullen, Jay; Campbell, Robert W.

2017-06-01

Phytoplankton growth in the Gulf of Alaska (GoA) is limited by iron (Fe), yet Fe sources are poorly constrained. We examine the temporal and spatial distributions of Fe, and its sources in the GoA, based on data from three cruises carried out in 2010 from the Copper River (AK) mouth to beyond the shelf break. April data are the first to describe late winter Fe behavior before surface water nitrate depletion began. Sediment resuspension during winter and spring storms generated high "total dissolvable Fe" (TDFe) concentrations of 1000 nmol kg-1 along the entire continental shelf, which decreased beyond the shelf break. In July, high TDFe concentrations were similar on the shelf, but more spatially variable, and driven by low-salinity glacial meltwater. Conversely, dissolved Fe (DFe) concentrations in surface waters were far lower and more seasonally consistent, ranging from 4 nmol kg-1 in nearshore waters to 0.6-1.5 nmol kg-1 seaward of the shelf break during April and July, despite dramatic depletion of nitrate over that period. The reasonably constant DFe concentrations are likely maintained during the year across the shelf by complexation by strong organic ligands, coupled with ample supply of labile particulate Fe. The April DFe data can be simulated using a simple numerical model that assumes a DFe flux from shelf sediments, horizontal transport by eddy diffusion, and removal by scavenging. Given how global change is altering many processes impacting the Fe cycle, additional studies are needed to examine controls on DFe in the Gulf of Alaska.

Temperature dependence of needle and shoot elongation before bud break in Scots pine.

PubMed

Schiestl-Aalto, Pauliina; Mäkelä, Annikki

2017-03-01

Knowledge about the early part of needle growth is deficient compared with what is known about shoot growth. It is however important to understand growth of different organs to be able to estimate the changes in whole tree growth in a changing environment. The onset of growth in spring has been observed to occur over some certain threshold value of momentary temperature or temperature accumulation. We measured the length growth of Scots pine (Pinus sylvestris L.) needles and shoots from March until bud break over 3 years. We first compared needle growth with concurrent shoot growth. Then, we quantified threshold temperature of growth (i) with a logistic regression based on momentary temperatures and (ii) with the temperature sum accumulation method. Temperature sum was calculated with combinations of various time steps, starting dates and threshold temperature values. Needle elongation began almost concurrently with shoot elongation and proceeded linearly in relation to shoot growth until bud break. When studying the threshold temperature for growth, the method with momentary temperature effect on growth onset yielded ambiguous results in our conditions. The best fit of an exponential regression between needle growth or length and temperature sum was obtained with threshold temperatures -1 to +2 °C, with several combinations of starting date and time step. We conclude that although growth onset is a momentary event the process leading to it is a long-term continuum where past time temperatures have to be accounted for, rather than a sudden switch from quiescence to active growth. Further, our results indicate that lower temperatures than the commonly used +5 °C are sufficient for actuating the growth process. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Phenology of temperate trees in tropical climates

NASA Astrophysics Data System (ADS)

Borchert, Rolf; Robertson, Kevin; Schwartz, Mark D.; Williams-Linera, Guadalupe

2005-09-01

Several North American broad-leaved tree species range from the northern United States at ˜47°N to moist tropical montane forests in Mexico and Central America at 15-20°N. Along this gradient the average minimum temperatures of the coldest month (T Jan), which characterize annual variation in temperature, increase from -10 to 12°C and tree phenology changes from deciduous to leaf-exchanging or evergreen in the southern range with a year-long growing season. Between 30 and 45°N, the time of bud break is highly correlated with T Jan and bud break can be reliably predicted for the week in which mean minimum temperature rises to 7°C. Temperature-dependent deciduous phenology—and hence the validity of temperature-driven phenology models—terminates in southern North America near 30°N, where T Jan>7°C enables growth of tropical trees and cultivation of frost-sensitive citrus fruits. In tropical climates most temperate broad-leaved species exchange old for new leaves within a few weeks in January-February, i.e., their phenology becomes similar to that of tropical leaf-exchanging species. Leaf buds of the southern ecotypes of these temperate species are therefore not winter-dormant and have no chilling requirement. As in many tropical trees, bud break of Celtis, Quercus and Fagus growing in warm climates is induced in early spring by increasing daylength. In tropical climates vegetative phenology is determined mainly by leaf longevity, seasonal variation in water stress and day length. As water stress during the dry season varies widely with soil water storage, climate-driven models cannot predict tree phenology in the tropics and tropical tree phenology does not constitute a useful indicator of global warming.

Circulation and water properties in the landfast ice zone of the Alaskan Beaufort Sea

NASA Astrophysics Data System (ADS)

Weingartner, Thomas J.; Danielson, Seth L.; Potter, Rachel A.; Trefry, John H.; Mahoney, Andy; Savoie, Mark; Irvine, Cayman; Sousa, Leandra

2017-09-01

Moorings, hydrography, satellite-tracked drifters, and high-frequency radar data describe the annual cycle in circulation and water properties in the landfast ice zone (LIZ) of the Alaskan Beaufort Sea. Three seasons, whose duration and characteristics are controlled by landfast ice formation and ablation, define the LIZ: ;winter;, ;break-up;, and ;open-water;. Winter begins in October with ice formation and ends in June when rivers commence discharging. Winter LIZ ice velocities are zero, under-ice currents are weak ( 5 cm s-1), and poorly correlated with winds and local sea level. The along-shore momentum balance is between along-shore pressure gradients and bottom and ice-ocean friction. Currents at the landfast ice-edge are swift ( 35 cm s-1), wind-driven, with large horizontal shears, and potentially unstable. Weak cross-shore velocities ( 1 cm s-1) imply limited exchanges between the LIZ and the outer shelf in winter. The month-long break-up season (June) begins with the spring freshet and concludes when landfast ice detaches from the bottom. Cross-shore currents increase, and the LIZ hosts shallow ( 2 m), strongly-stratified, buoyant and sediment-laden, under-ice river plumes that overlie a sharp, 1 m thick, pycnocline across which salinity increases by 30. The plume salt balance is between entrainment and cross-shore advection. Break-up is followed by the 3-month long open-water season when currents are swift (≥20 cm s-1) and predominantly wind-driven. Winter water properties are initialized by fall advection and evolve slowly due to salt rejection from ice. Fall waters and ice within the LIZ derive from local rivers, the Mackenzie and/or Chukchi shelves, and the Arctic basin.

Center for Alternative Energy Storage Research and Technology

DTIC Science & Technology

2013-03-28

measurement systems needed for characterization of the resulting exfoliated graphite coated metal nanowires for their evaluation in supercapacitors...Synthesis of exfoliated graphite nanoplatelet (xGnP) composite carbon aerogels for use in supercapacitors,” oral presentation at the Spring, Materials...Research Society Meeting in San Francisco, CA. W. Qian, J. Cintron-Rivera, S. Han, X. Lu and F. Z. Peng, “Management and control of energy storage

Post-harvest prescribed burning of oak stands: an alternative to the shelterwood-burn technique?

Treesearch

Patrick H. Brose

2013-01-01

Prescribed burning of two mixed-oak (Quercus spp.) stands in northwestern Pennsylvania 4 and 5 years after the final removal cut of a three-step shelterwood sequence was investigated. One stand was burned with hot mid-spring fire in May 2005 and the other treated likewise in May 2006. Understory inventories 3 years later showed reductions in black...

Local Normative Data on easyCBM[R] Reading and Mathematics: Fall 2009. Technical Report # 0918

ERIC Educational Resources Information Center

Tindal, Gerald; Alonzo, Julie; Anderson, Daniel

2009-01-01

We developed equivalent, alternate forms of easyCBM[R] in reading (n=20 forms) and mathematics (n=13 forms) with different skills reflective of the National Reading Panel (NRP) and the National Council of Teachers of Mathematics (NCTM), respectively. We then took three forms to use as screening measures in the fall, winter, and spring so educators…

Observation of nonlinear dissipation in piezoresistive diamond nanomechanical resonators by heterodyne down-mixing.

PubMed

Imboden, Matthias; Williams, Oliver A; Mohanty, Pritiraj

2013-09-11

We report the observation of nonlinear dissipation in diamond nanomechanical resonators measured by an ultrasensitive heterodyne down-mixing piezoresistive detection technique. The combination of a hybrid structure as well as symmetry breaking clamps enables sensitive piezoresistive detection of multiple orthogonal modes in a diamond resonator over a wide frequency and temperature range. Using this detection method, we observe the transition from purely linear dissipation at room temperature to strongly nonlinear dissipation at cryogenic temperatures. At high drive powers and below liquid nitrogen temperatures, the resonant structure dynamics follows the Pol-Duffing equation of motion. Instead of using the broadening of the full width at half-maximum, we propose a nonlinear dissipation backbone curve as a method to characterize the strength of nonlinear dissipation in devices with a nonlinear spring constant.

Preparation of Total RNA from Fission Yeast.

PubMed

Bähler, Jürg; Wise, Jo Ann

2017-04-03

Treatment with hot phenol breaks open fission yeast cells and begins to strip away bound proteins from RNA. Deproteinization is completed by multiple extractions with chloroform/isoamyl alcohol and separation of the aqueous and organic phases using MaXtract gel, an inert material that acts as a physical barrier between the phases. The final step is concentration of the RNA by ethanol precipitation. The protocol can be used to prepare RNA from several cultures grown in parallel, but it is important not to process too many samples at once because delays can be detrimental to RNA quality. A reasonable number of samples to process at once would be three to four for microarray or RNA sequencing analyses and six for preliminary investigations of mutants implicated in RNA metabolism. © 2017 Cold Spring Harbor Laboratory Press.

Water survey of Canada: Application for use of ERTS-A for retransmission of water resources data

NASA Technical Reports Server (NTRS)

Halliday, R. A. (Principal Investigator); Reid, I. A.

1974-01-01

The author has identified the following significant results. Water resources data were retransmitted from nine data collection platforms (DCP) located in remote regions of Canada. The DCPs located in the Arctic operated in temperatures lower than -40 C and the DCP antennas have survived wind speeds of greater than 80 kph and snow loads of a depth of one metre. Ice-out indicators were installed at a few DCP sites. The purpose of these indicators was to enable the detection of the movement of ice out of river channel during spring break-up. The suitability of satellite retransmission as a means of obtaining data from remote areas of Canada continues to be demonstrated. A modest expansion of the DCP network is planned.

On the Role of SST Forcing in the 2011 and 2012 Extreme U.S. Heat and Drought: A Study in Contrasts

NASA Technical Reports Server (NTRS)

Wang, Hailan; Schubert, Siegfried; Koster, Randal; Ham, Yoo-Geun; Suarez, Max

2013-01-01

This study compares the extreme heat and drought that developed over the United States in 2011 and 2012 with a focus on the role of SST forcing. Experiments with the NASA GEOS-5 atmospheric general circulation model show that the winter/spring response over the U.S. to the Pacific SST is remarkably similar for the two years despite substantial differences in the tropical Pacific SST. As such, the pronounced winter and early spring temperature differences between the two years (warmth confined to the south in 2011 and covering much of the continent in 2012) primarily reflect differences in the contributions from the Atlantic and Indian Oceans, with both acting to cool the east and upper mid-west during 2011, while during 2012 the Indian Ocean reinforced the Pacific-driven continental-wide warming and the Atlantic played a less important role. During late spring and summer of 2011 the tropical Pacific SST force a continued warming and drying over the southern U.S., though considerably weaker than observed. Nevertheless, the observed anomalies fall within the models intra-ensemble spread. In contrast, the rapid development of intense heat and drying over the central U.S. during June and July of 2012 falls outside the models intra-ensemble spread. The response to the SST (a northward expansion of a modest summer warming linked to the Atlantic) gives little indication that 2012 would produce record-breaking precipitation deficits and heat in the central Great Plains. A diagnosis of the 2012 observed circulation anomalies shows that the most extreme heat and drought was tied to the development of a stationary Rossby wave and an associated anomalous upper tropospheric high maintained by weather transients.

Delayed dehiscence of the pericarp: role in germination and retention of viability of seeds of two cold desert annual Brassicaceae species.

PubMed

Lu, J J; Tan, D Y; Baskin, C C; Baskin, J M

2017-01-01

Considerable variation occurs in post-maturity timing of dehiscence in fruits of Brassicaceae species, and several studies have shown that the pericarp plays an important role in seed germination and retention of viability in species with indehiscent fruits. However, little is known about the significance to seed biology of delay in pericarp dehiscence for <1 year in the field. Thus, we determined the role of the pericarps of Leptaleum filifolium and Neotorularia korolkovii, which open in <1 year after fruit maturity and dispersal, in seed germination and retention of seed viability. We compared dormancy-break via after-ripening in the laboratory and germination phenology and retention of seed viability in intact siliques and isolated seeds buried in an experimental garden. Seeds of both species have Type 6 non-deep physiological dormancy, which is enhanced by the pericarp. Seeds of both species after-ripened during summer 2013, and some of them germinated in autumn and some in the following spring in watered and non-watered soil. Germination percentages of seeds in siliques increased in soil in spring 2014, after the pericarps had opened. Most isolated seeds of L. filifolium and N. korolkovii had germinated or were dead by spring 2014 and summer 2015, respectively, whereas 60% of the seeds of both species in the (opened) pericarps were viable after 24 months. Thus, although the pericarp opened 9-10 months after burial, its presence had a significant effect on seed dormancy, germination phenology and retention of viability of seeds of L. filifolium and N. korolkovii. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

Screening of Thermophilic Bacteria Produce Xylanase from Sapan Sungai Aro Hot Spring South Solok

NASA Astrophysics Data System (ADS)

Irdawati, I.; Syamsuardi, S.; Agustien, A.; Rilda, Y.

2018-04-01

xylanase is one of the enzymes with great prospects as hemicellulose hydrolyzing enzyme. Global annual market demand for this enzyme reach US 200 million. This enzyme catalyzes the xylan (hemicellulose) reactions breaking into xilooligosakarida and xylose. Xylanase can be applied to various industrial sectors such as bread, sugar xylose, biofuels, especially in bleaching paper (bleaching) pulp. Xylanase Isable to replace conventional chemical bleaching using chlorine that is not friendly for the environment. Currently xylanase production is extracted from the thermophilic bacteria for enzyme stability at high temperatures that are suitable for industrial applications. Thermophilic bacteria can be isolated from a hot spring, one of the which is a source of Sapan Sungai Aro Hot Spring, located in the district South Solok. The aim of this study was to select and identification of thermophilic bacteria can produce xylanase.This roomates is a descriptive study, which was Carried out in the Laboratory of Microbiology, Mathematic and Science Faculty of Padang State University, and Laboratory of Bacteriology, BasoVeterinary Research Center. The research procedure consisted of the preparation and sterilization of materials and tools, medium manufacturing, regeneration, selection and identification. Selection is performed by using a semiquantitative screening plate that contains xylan substrate. Identification is based on microscopic and biochemical characteristics until the genus level.Selection results Showed 12 out of 16 isolates had xilanolitik activity, with the highest activity is SSA2 with xilanolitik index of 0.74. The top five index producehigestxilanolitik isolates that are SSA2, SSA3 and SSA4 identified as Bacillus sp. 1., and SSAS6 and SSA7 is Bacillus sp. 2.

A study of in-situ sediment flocculation in the turbidity maxima of the Yangtze Estuary

NASA Astrophysics Data System (ADS)

Guo, Chao; He, Qing; Guo, Leicheng; Winterwerp, Johan C.

2017-05-01

In order to improve our understandings of temporal and vertical variations of sediment flocculation dynamics within the turbidity maxima (TM) of the highly turbid Yangtze Estuary (YE), we deployed LISST-100C, a laser instrument for in-situ monitor of the sizes and concentrations of flocculated particles in a wet season. Field data in terms of vertical profiles of flow velocity, suspended sediment concentration (SSC), salinity, flocculated particle size distribution and volume concentration were obtained, based on field works conducted at consecutive spring, moderate, and neap tides. Data analyses show that the mean floc diameters (DM) were in the range of 14-95 μm, and flocculation exhibited strong temporal and vertical variations within a tidal cycle and between spring-neap cycles. Larger DM were observed during high and low slack waters, and the averaged floc size at neap tide was found 57% larger than at spring tide. Effective density of flocs decreased with the increase of floc size, and fractal dimension of flocs in the YE was mainly between 1.5 and 2.1. We also estimated the settling velocity of flocs by 0.04-0.6 mm s-1 and the largest settling velocity occurred also at slack waters. Moreover, it is found that turbulence plays a dominant role in the flocculation process. Floc size decreases significantly when the shear rate parameter G is > 2-3 s-1, suggesting the turbulence breaking force. Combined effects of fine sediment flocculation, enhanced settling process, and high sediment concentration resulted in a large settling flux around high water, which can in part explain the severe siltation in the TM of the YE, thus shedding lights on the navigation channel management.

STS-78 Crew at Pad 39B during TCDT

NASA Technical Reports Server (NTRS)

1996-01-01

STS-78 flight crew members and their alternates pose in front of the Space Shuttle Columbia at Launch Pad 39B during a break in Terminal Countdown Demonstration Test (TCDT) activities for that mission. They are (from left, standing) Alternate Payload Specialist Pedro Duque; Pilot Kevin R. Kregel; Mission Specialist Charles E. Brady, Jr.; Mission Commander Terence T. 'Tom' Henricks; Mission Specialist Richard M. Linnehan; Alternate Payload Specialist Luca Urbani; and Payload Specialist Jean- Jaques Favier. Kneeling in the foreground are Payload Specialist Robert D. Thirsk and Payload Commander Susan J. Helms. The TCDT includes a simulated full-scale countdown, crew pad egress training and other activities. During the nearly 16-day mission, the seven-member crew will conduct 22 medical, materials and physics investigations in the Life and Microgravity Spacelab (LMS) located in Columbia's payload bay.

Transposition-mediated DNA re-replication in maize

PubMed Central

Zhang, Jianbo; Zuo, Tao; Wang, Dafang; Peterson, Thomas

2014-01-01

Every DNA segment in a eukaryotic genome normally replicates once and only once per cell cycle to maintain genome stability. We show here that this restriction can be bypassed through alternative transposition, a transposition reaction that utilizes the termini of two separate, nearby transposable elements (TEs). Our results suggest that alternative transposition during S phase can induce re-replication of the TEs and their flanking sequences. The DNA re-replication can spontaneously abort to generate double-strand breaks, which can be repaired to generate Composite Insertions composed of transposon termini flanking segmental duplications of various lengths. These results show how alternative transposition coupled with DNA replication and repair can significantly alter genome structure and may have contributed to rapid genome evolution in maize and possibly other eukaryotes. DOI: http://dx.doi.org/10.7554/eLife.03724.001 PMID:25406063

Energy crops cultivated on the slag from incineration of the sewage sludge energy value assessment

NASA Astrophysics Data System (ADS)

Głowacka, Anna; Tarnowski, Krzysztof; Bering, Sławomira; Mazur, Jacek; Kiper, Justyna; Wołoszyk, Czesław

2017-11-01

In 2011-2013, research on the fertilizer value of slag from the incineration of municipal sewage sludge as an alternative source of phosphorus was carried out. The research scheme included 5 variants (in 4 repetitions) fertilization cultivated for grain with mineral fertilizers and ash. (P1, P2 and P3 - consecutive doses of phosphorus from ash) from municipal sewage sludge combustion: NK, NPK, NK+P1, NK+P2 and NK+P3. The obtained results indicate that the average of the three years of research, the value for the straw spring rape heat of combustion was 15.99 MJ/kg d.m., corn straw 16.20 MJ/kg d.m., triticale straw 17.06 MJ/kg d.m. and Miscanthus 17.34 MJ/kg d.m. The highest value of combustion heat for spring rape straw and miscanthus performed for objects fertilized with NK + P3 - 16.08 MJ/kg d.m. (Spring rape) and 17.57 MJ/kg d.m. (Miscanthus); For corn straw objects fertilized with nitrogen and potassium - 16.35 MJ/kg d.m. and triticale straw objects fertilized with NPK and NK + P2 - 17.10 MJ/kg d.m. Straw calorific value of tested plants was lower than the combustion heat by an average of 6.97% (triticale) to 7.38% (spring rape).

Los Alamos National Laboratory considers the use of biodiesel.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matlin, M. K.

2002-01-01

A new EPA-approved alternative fuel, called biodiesel, may soon be used at Los Alamos National Laboratory in everything from diesel trucks to laboratory equipment. Biodiesel transforms vegetable oils into a renewable, cleaner energy source that can be used in any machinery that uses diesel fuel. For the past couple years, the Laboratory has been exploring the possibility of switching over to soybean-based biodiesel. This change could lead to many health and environmental benefits, as well as help reduce the nation's dependence on foreign oil. Biodiesel is a clean, renewable diesel fuel substitute made from soybean and other vegetable oil crops,more » as well as from recycled cooking oils. A chemical process breaks down the vegetable oil into a usable form. Vegetable oil has a chain of about 18 carbons and ordinary diesel has about 12 or 13 carbons. The process breaks the carbon chains of the vegetable oil and separates out the glycerin (a fatty substance used in creams and soaps). The co-product of glycerin can be used by pharmaceutical and cosmetic companies, as well as many other markets. Once the chains are shortened and the glycerin is removed from the oil, the remaining liquid is similar to petroleum diesel fuel. It can be burned in pure form or in a blend of any proportion with petroleum diesel. To be considered an alternative fuel source by the EPA, the blend must be at least 20 percent biodiesel (B20). According to the U.S. Department of Energy (DOE), biodiesel is America's fastest growing alternative fuel.« less

'Checkmating HIV&AIDS': Using chess to break the silence in the classroom.

PubMed

Esau, Omar

2012-12-01

In this article, I give an account of my 'Checkmating HIV&AIDS' action research project, which was an attempt to break the 'culture of silence' concerning HIV&AIDS and sex and sexuality in my classroom. In this project, I focused specifically on one code of sport, namely chess, and I point out and discuss the potential of using chess as an educational tool in addressing HIV&AIDS. It was found that learners enjoy playing chess and that it can be used in the Life Orientation classroom to promote HIV&AIDS awareness. This type of alternative awareness is relevant as learners in most schools were becoming fatigued by HIV&AIDS information overload. The project portrays the role of the teacher as a researcher and critical change agent in an HIV&AIDS-challenged society.

Repair of Double-Strand Breaks by End Joining

PubMed Central

Chiruvella, Kishore K.; Liang, Zhuobin; Wilson, Thomas E.

2013-01-01

Nonhomologous end joining (NHEJ) refers to a set of genome maintenance pathways in which two DNA double-strand break (DSB) ends are (re)joined by apposition, processing, and ligation without the use of extended homology to guide repair. Canonical NHEJ (c-NHEJ) is a well-defined pathway with clear roles in protecting the integrity of chromosomes when DSBs arise. Recent advances have revealed much about the identity, structure, and function of c-NHEJ proteins, but many questions exist regarding their concerted action in the context of chromatin. Alternative NHEJ (alt-NHEJ) refers to more recently described mechanism(s) that repair DSBs in less-efficient backup reactions. There is great interest in defining alt-NHEJ more precisely, including its regulation relative to c-NHEJ, in light of evidence that alt-NHEJ can execute chromosome rearrangements. Progress toward these goals is reviewed. PMID:23637284

Defining International Contracting Terms

DTIC Science & Technology

1994-09-01

compensation so that another nation or company can make a sale or export. The Coca - Cola company refused to accept offsets to break into the lucrative Soviet...Union Market. Their main competitor, Pepsi- Cola , broke into this market 15 years earlier by accepting Stolichnaya vodka as a reciprocal purchase, a... advantages over the other available alternatives (personal interviews or a telephone A-2 survey). While personal interviews offer the advantages of a high

A Systematic Cathode Study-Activation of a Thermionic Cathode, and Measuring Cesium Evaporation from a Dispenser Photocathode

DTIC Science & Technology

2010-06-01

QCM Quartz Crystal Deposition Monitor SEM Scanning Electron Microscope SRF Superconducting Radio Frequency T Torr Ti Titanium UHV Ultra...High Vacuum ( ᝺-7 Torr) UM University of Maryland QCM Quartz Crystal Deposition Monitor V Volt VAC Voltage-Alternating Current xvii...event. The two originally had problems with their tungsten filaments crystallizing and breaking. Being experimentalists, they added thorium in an

Operational Design: The Importance of Getting the Fundamentals Right

DTIC Science & Technology

2010-04-01

problems require only a simple form of Aristotelian mission analysis. They can be broken down into parts and treated accordingly. Davison 44...collection of subtly alternative but essentially derivative theories have promised to break through into mainstream doctrine. SOD itself has matured...desired system frame. This is the theory of action that informs the rest of the planning process. This transitional step is commander led, as it

Serving a Stranger or Serving Myself: Alternative Breaks and the Influence of Race and Ethnicity on Student Understanding of Themselves and Others

ERIC Educational Resources Information Center

Niehaus, Elizabeth; Rivera, Mark

2015-01-01

Given the ever increasing numbers of Students of Color engaging in higher education, the importance of cross-cultural interactions for all students, and the evidence that White students and Students of Color may have vastly different experiences in higher education, there is a need to further explore the types of cross-cultural experiences that…

Biofiltration as a Viable Alternative for Air Pollution Control at Department of Defense Surface Coating Facilities

DTIC Science & Technology

2007-03-01

enzymes or energy to break down the contaminants (Devinny, 1999). Known biologically toxic compounds should be avoided altogether if using a...mesophilic and thermophilic temperature ranges, however, most biodegradation is executed by mesophiles and thermophiles (Leson and Winer, 1991). Of...ambient temperatures. Some microbes are known to function effectively in thermophilic conditions (40-55 °C). For example, microbes were shown to have

Techno-economic analysis of fuel cell auxiliary power units as alternative to idling

NASA Astrophysics Data System (ADS)

Jain, Semant; Chen, Hsieh-Yeh; Schwank, Johannes

This paper presents a techno-economic analysis of fuel-cell-based auxiliary power units (APUs), with emphasis on applications in the trucking industry and the military. The APU system is intended to reduce the need for discretionary idling of diesel engines or gas turbines. The analysis considers the options for on-board fuel processing of diesel and compares the two leading fuel cell contenders for automotive APU applications: proton exchange membrane fuel cell and solid oxide fuel cell. As options for on-board diesel reforming, partial oxidation and auto-thermal reforming are considered. Finally, using estimated and projected efficiency data, fuel consumption patterns, capital investment, and operating costs of fuel-cell APUs, an economic evaluation of diesel-based APUs is presented, with emphasis on break-even periods as a function of fuel cost, investment cost, idling time, and idling efficiency. The analysis shows that within the range of parameters studied, there are many conditions where deployment of an SOFC-based APU is economically viable. Our analysis indicates that at an APU system cost of 100 kW -1, the economic break-even period is within 1 year for almost the entire range of conditions. At 500 kW -1 investment cost, a 2-year break-even period is possible except for the lowest end of the fuel consumption range considered. However, if the APU investment cost is 3000 kW -1, break-even would only be possible at the highest fuel consumption scenarios. For Abram tanks, even at typical land delivered fuel costs, a 2-year break-even period is possible for APU investment costs as high as 1100 kW -1.

Nepheloid Layers: Origin and Development In A Narrow Continental Shelf (nw Portugal)

NASA Astrophysics Data System (ADS)

Oliveira, A.; Vitorino, J.; Rodrigues, A.; Jouanneau, J. M.; Weber, O.; Dias, J. A.

A general hydrographic, nephelometric and sedimentological surveying of the NW Portuguese continental shelf and slope was undertaken, under winter and spring con- ditions in order to elaborate a conceptual model of suspended sediments (nepheloid layer) dynamics. Two major situations were found: 1) Spring/Summer - with northerly winds (upwelling) and low energetic wave regime that favour the deposition of sedi- ments. The northerly winds promote offshore transport in the surface nepheloid layer (SNL) and the establishment of a seasonal thermocline allow the expansion of the SNL to the west. The SNL can reach or even cross the shelf-break (50 km from coastline). Particulate organic carbon (POC) content in this layer highlights the higher contribution of biogenic particles (average concentration of 22%); 2) Winter, with southerly winds (downwelling) and high energetic wave regime that favour mid- shelf sediments resuspension and offshore transport in the bottom nepheloid layer (BNL). In the shelf-break the BNL detached to form intermediate nepheloid layers (INL). The SNL is restricted to the inner shelf. The effect of southerly winds gener- ates shoreward Ekman transport and detains the offshore westward extension of this layer even during high river run-off periods. The POC content indicates a dominance of litogenic particles in suspension (average concentration of 8%). Over the mid- and inner-shelf the dominant resuspension mechanism is associated with surface waves (Vitorino et al., 2002). Estimates based on wave measurements at mid-shelf (86m depth) suggested that, in winter, the wave shear velocity frequently exceeds 1 cm/s, assumed as the critical shear velocity for the resuspension of the fine grained sedi- ments (34m) of the bottom cover. Storm events, such as the one observed in November 1996 easily increase the wave shear velocities over 3 cm/s, leading to the increase of the BNL thickness (20-30m) (Vitorino et al., 2002; Oliveira et al., 2002). Low-frequency currents (periods longer than about 2 days) and internal waves can also lead to the resuspension of fine bottom sediments. Shelf morphology (outer shelf re- lieves and Porto submarine canyon) and sedimentary cover can also affect both spatial and vertical development of BNL.

Stable isotope labeling confirms mixotrophic nature of streamer biofilm communities at alkaline hot springs.

PubMed

Schubotz, Florence; Hays, Lindsay E; Meyer-Dombard, D'Arcy R; Gillespie, Aimee; Shock, Everett L; Summons, Roger E

2015-01-01

Streamer biofilm communities (SBC) are often observed within chemosynthetic zones of Yellowstone hot spring outflow channels, where temperatures exceed those conducive to photosynthesis. Nearest the hydrothermal source (75-88°C) SBC comprise thermophilic Archaea and Bacteria, often mixed communities including Desulfurococcales and uncultured Crenarchaeota, as well as Aquificae and Thermus, each carrying diagnostic membrane lipid biomarkers. We tested the hypothesis that SBC can alternate their metabolism between autotrophy and heterotrophy depending on substrate availability. Feeding experiments were performed at two alkaline hot springs in Yellowstone National Park: Octopus Spring and "Bison Pool," using various (13)C-labeled substrates (bicarbonate, formate, acetate, and glucose) to determine the relative uptake of these different carbon sources. Highest (13)C uptake, at both sites, was from acetate into almost all bacterial fatty acids, particularly into methyl-branched C15, C17 and C19 fatty acids that are diagnostic for Thermus/Meiothermus, and some Firmicutes as well as into universally common C16:0 and C18:0 fatty acids. (13)C-glucose showed a similar, but a 10-30 times lower uptake across most fatty acids. (13)C-bicarbonate uptake, signifying the presence of autotrophic communities was only significant at "Bison Pool" and was observed predominantly in non-specific saturated C16, C18, C20, and C22 fatty acids. Incorporation of (13)C-formate occurred only at very low rates at "Bison Pool" and was almost undetectable at Octopus Spring, suggesting that formate is not an important carbon source for SBC. (13)C-uptake into archaeal lipids occurred predominantly with (13)C-acetate, suggesting also that archaeal communities at both springs have primarily heterotrophic carbon assimilation pathways. We hypothesize that these communities are energy-limited and predominantly nurtured by input of exogenous organic material, with only a small fraction being sustained by autotrophic growth.

Parametric Resonances of a Conductive Pipe Driven by an Alternating Magnetic Field in the Presence of a Static Magnetic Field

ERIC Educational Resources Information Center

Donoso, Guillermo; Ladera, Celso L.

2012-01-01

The parametric oscillations of an oscillator driven electromagnetically are presented. The oscillator is a conductive pipe hung from a spring, and driven by the oscillating magnetic field of a surrounding coil in the presence of a static magnetic field. It is an interesting case of parametric oscillations since the pipe is neither a magnet nor a…

Resonances of an Oscillating Conductive Pipe Driven by an Alternating Magnetic Field in the Presence of a Static Magnetic Field

ERIC Educational Resources Information Center

Ladera, Celso L.; Donoso, Guillermo

2011-01-01

A short conducting pipe that hangs from a weak spring is forced to oscillate by the magnetic field of a surrounding coaxial coil that has been excited by a low-frequency current source in the presence of an additional static magnetic field. Induced oscillating currents appear in the pipe. The pipe motion becomes damped by the dragging forces…

Analysis of Energy-Absorbing Foundations.

DTIC Science & Technology

1978-12-15

side rails. At the top of the rebound, air brakes are automatically activated which press against the rails and stop the table, preventing a second...for the same application to automobile bumpers , was greater than that used in an alternate design in which the tube was crushed axially, so it appears...shock mounts prepared by Burns [48]. Typi- cal non-linear, elastic, load-deflection curves are given for helical springs, pneumatic cylinders, hydraulic

Dynamically balanced, hydraulically driven compressor/pump apparatus for resonant free piston Stirling engines

DOEpatents

Corey, John A.

1984-05-29

A compressor, pump, or alternator apparatus is designed for use with a resonant free piston Stirling engine so as to isolate apparatus fluid from the periodically pressurized working fluid of the Stirling engine. The apparatus housing has a first side closed by a power coupling flexible diaphragm (the engine working member) and a second side closed by a flexible diaphragm gas spring. A reciprocally movable piston is disposed in a transverse cylinder in the housing and moves substantially at right angles relative to the flexible diaphragms. An incompressible fluid fills the housing which is divided into two separate chambers by suitable ports. One chamber provides fluid coupling between the power diaphragm of the RFPSE and the piston and the second chamber provides fluid coupling between the gas spring diaphragm and the opposite side of the piston. The working members of a gas compressor, pump, or alternator are driven by the piston. Sealing and wearing parts of the apparatus are mounted at the external ends of the transverse cylinder in a double acting arrangement for accessibility. An annular counterweight is mounted externally of the reciprocally movable piston and is driven by incompressible fluid coupling in a direction opposite to the piston so as to damp out transverse vibrations.

Fusional vergence detected by prism bar and synoptophore in chinese childhood intermittent exotropia.

PubMed

Fu, Tao; Wang, Jing; Levin, Moran; Su, Qing; Li, Dongguo; Li, Junfa

2015-01-01

Purpose. To measure the changes in fusional vergence in Chinese children with intermittent exotropia (IXT) and the association with the control of IXT. Methods. Ninety-two patients with IXT (8-15 years old) were compared with 86 controls. Exodeviation control was evaluated using the Revised Newcastle Control Score. Angle of deviation was measured using prism and alternate cover testing at distance and near. Fusional vergence was measured using prism bar and synoptophore. This study was registered with ChiCTR-RCC-13003920. Results. Using prism bar, convergence break points were lower whereas divergence break points were higher in children with IXT at distance (P < 0.001) and near (P < 0.001) compared with controls. There was no significant difference in mean divergence amplitudes between the two groups when testing using a synoptophore (P = 0.53). In children with IXT, the distance between recovery point and break point in both convergence (distance: P = 0.02; near: P = 0.02) and divergence (distance: P < 0.001; near: P < 0.001) was larger than controls when detected by prism bar and synoptophore (convergence: P = 0.005; divergence: P = 0.006). Conclusions. Children with IXT have reduced convergence amplitudes as detected by both prism bar and synoptophore.

Alternative methods to model frictional contact surfaces using NASTRAN

NASA Technical Reports Server (NTRS)

Hoang, Joseph

1992-01-01

Elongated (slotted) holes have been used extensively for the integration of equipment into Spacelab racks. In the past, this type of interface has been modeled assuming that there is not slippage between contact surfaces, or that there is no load transfer in the direction of the slot. Since the contact surfaces are bolted together, the contact friction provides a load path determined by the normal applied force (bolt preload) and the coefficient of friction. Three alternate methods that utilize spring elements, externally applied couples, and stress dependent elements are examined to model the contacted surfaces. Results of these methods are compared with results obtained from methods that use GAP elements and rigid elements.

Aircraft interior noise reduction by alternate resonance tuning

NASA Technical Reports Server (NTRS)

Bliss, Donald B.; Gottwald, James A.; Gustaveson, Mark B.; Burton, James R., III

1988-01-01

Model problem development and analysis continues with the Alternate Resonance Tuning (ART) concept. The various topics described are presently at different stages of completion: investigation of the effectiveness of the ART concept under an external propagating pressure field associated with propeller passage by the fuselage; analysis of ART performance with a double panel wall mounted in a flexible frame model; development of a data fitting scheme using a branch analysis with a Newton-Raphson scheme in multiple dimensions to determine values of critical parameters in the actual experimental apparatus; and investigation of the ART effect with real panels as opposed to the spring-mass-damper systems currently used in much of the theory.

Shape memory alloy resetable spring lift for pedestrian protection

NASA Astrophysics Data System (ADS)

Barnes, Brian M.; Brei, Diann E.; Luntz, Jonathan E.; Strom, Kenneth; Browne, Alan L.; Johnson, Nancy

2008-03-01

Pedestrian protection has become an increasingly important aspect of automotive safety with new regulations taking effect around the world. Because it is increasingly difficult to meet these new regulations with traditional passive approaches, active lifts are being explored that increase the "crush zone" between the hood and rigid under-hood components as a means of mitigating the consequences of an impact with a non-occupant. Active lifts, however, are technically challenging because of the simultaneously high forces, stroke and quick timing resulting in most of the current devices being single use. This paper introduces the SMArt (Shape Memory Alloy ReseTable) Spring Lift, an automatically resetable and fully reusable device, which couples conventional standard compression springs to store the energy required for a hood lift, with Shape Memory Alloys actuators to achieve both an ultra high speed release of the spring and automatic reset of the system for multiple uses. Each of the four SMArt Device subsystems, lift, release, lower and reset/dissipate, are individually described. Two identical complete prototypes were fabricated and mounted at the rear corners of the hood, incorporated within a full-scale vehicle testbed at the SMARTT (Smart Material Advanced Research and Technology Transfer) lab at University of Michigan. Full operational cycle testing of a stationary vehicle in a laboratory setting confirms the ultrafast latch release, controlled lift profile, gravity lower to reposition the hood, and spring recompression via the ratchet engine successfully rearming the device for repeat cycles. While this is only a laboratory demonstration and extensive testing and development would be required for transition to a fielded product, this study does indicate that the SMArt Lift has promise as an alternative approach to pedestrian protection.

Dynamic Vulnerability of Karst Systems: a Concept to understand qualitative and quantitative Aspects of Karst springs due to Changes in Groundwater Recharge

NASA Astrophysics Data System (ADS)

Huggenberger, P.; Butscher, C.; Epting, J.; Auckenthaler, A.

2015-12-01

Karst groundwater resources represent valuable water resources, which may be affected by different types of pollution and changes of groundwater recharge by climate change. In many parts of Europe, it has been predicted that record-breaking heat waves, such as the one experienced in 2003 and 2015, will become more frequent. At the same time, even as summers become drier, the incidence of severe precipitation events could increase. What is the influence such changes to the quantitative and qualitative aspects of Karst groundwater systems? A factor to be considered in conjunction with groundwater quality is the vulnerability of the resource, which is defined as the sensitivity of a groundwater system to pollution. Intrinsic vulnerability refers to the sensitivity to pollution when considering only natural, geogenic conditions without the effects of human activities such as contaminant release. Intrinsic vulnerability depends on the recharge conditions, which are dependent on the surface and subsurface structure and on precipitation and evaporation patterns. The latter are highly time dependent. Therefore, our groundwater vulnerability concept also includes dynamic aspects of the system, the variations of spatial and temporal components. We present results of combined monitoring and modelling experiments of several types of Karst systems in the Tabular and the Folded Jura of NW Switzerland. The recharge, conduit flow, diffuse flow(RCD) rainfall-discharge model "RCD-seasonal" was used to simulate the discharge and substance concentration of several spring. This lumped parameter model include: the recharge system (soil and epikarst system), the conduit flow system, and the diffuse flow system. The numerically derived Dynamic Vulnerability Index (DVI) can indicate qualitative changes of spring water with sufficient accuracy to be used for drinking water management. In addition, the results obtained from the test sites indicate a decrease in short-lived contaminants in spring water as a result of climate change. The impact of persistent contaminants, however, can only be determined if future climatic conditions at the site can be estimated with sufficient accuracy, because predicted summer heat waves and severe rainfall events will have opposite effects on the groundwater vulnerability.

Force probe simulations of a reversibly rebinding system: Impact of pulling device stiffness

NASA Astrophysics Data System (ADS)

Jaschonek, Stefan; Diezemann, Gregor

2017-03-01

We present a detailed study of the parameter dependence of force probe molecular dynamics (FPMD) simulations. Using a well studied calix[4]arene catenane dimer as a model system, we systematically vary the pulling velocity and the stiffness of the applied external potential. This allows us to investigate how the results of pulling simulations operating in the constant velocity mode (force-ramp mode) depend on the details of the simulation setup. The system studied has the further advantage of showing reversible rebinding meaning that we can monitor the opening and the rebinding transition. Many models designed to extract kinetic information from rupture force distributions work in the limit of soft springs and all quantities are found to depend solely on the so-called loading rate, the product of spring stiffness and pulling velocity. This approximation is known to break down when stiff springs are used, a situation often encountered in molecular simulations. We find that while some quantities only depend on the loading rate, others show an explicit dependence on the spring constant used in the FPMD simulation. In particular, the force versus extension curves show an almost stiffness independent rupture force but the force jump after the rupture transition does depend roughly linearly on the value of the stiffness. The kinetic rates determined from the rupture force distributions show a dependence on the stiffness that can be understood in terms of the corresponding dependence of the characteristic forces alone. These dependencies can be understood qualitatively in terms of a harmonic model for the molecular free energy landscape. It appears that the pulling velocities employed are so large that the crossover from activated dynamics to diffusive dynamics takes place on the time scale of our simulations. We determine the effective distance of the free energy minima of the closed and the open configurations of the system from the barrier via an analysis of the hydrogen-bond network with results in accord with earlier simulations. We find that the system is quite brittle in the force regime monitored in the sense that the barrier is located near to the closed state.

Alternative Z ' bosons in E 6

NASA Astrophysics Data System (ADS)

Rojas, Eduardo; Erler, Jens

2015-10-01

We classify the quantum numbers of the extra U(1)' symmetries contained in E 6. In particular, we categorize the cases with rational charges and present the full list of models which arise from the chains of the maximal subgroups of E 6. As an application, the classification allows us to determine all embeddings of the Standard Model fermions in all possible decompositions of the fundamental representation of E 6 under its maximal subgroups. From this we find alternative chains of subgroups for Grand Unified Theories. We show how many of the known models including some new ones appear in alternative breaking patterns. We also use low energy constraints coming from parity-violating asymmetry measurements and atomic parity non-conservation to set limits on the E 6 motivated parameter space for a Z ' boson mass of 1.2 TeV. We include projected limits for the present and upcoming QWEAK, MOLLER and SOLID experiments.

Mangrove forest against dyke-break-induced tsunami on rapidly subsiding coasts

NASA Astrophysics Data System (ADS)

Takagi, Hiroshi; Mikami, Takahito; Fujii, Daisuke; Esteban, Miguel; Kurobe, Shota

2016-07-01

Thin coastal dykes typically found in developing countries may suddenly collapse due to rapid land subsidence, material ageing, sea-level rise, high wave attack, earthquakes, landslides, or a collision with vessels. Such a failure could trigger dam-break tsunami-type flooding, or "dyke-break-induced tsunami", a possibility which has so far been overlooked in the field of coastal disaster science and management. To analyse the potential consequences of one such flooding event caused by a dyke failure, a hydrodynamic model was constructed based on the authors' field surveys of a vulnerable coastal location in Jakarta, Indonesia. In a 2 m land subsidence scenario - which is expected to take place in the study area after only about 10-20 years - the model results show that the floodwaters rapidly rise to a height of nearly 3 m, resembling the flooding pattern of earthquake-induced tsunamis. The depth-velocity product criterion suggests that many of the narrow pedestrian paths behind the dyke could experience strong flows, which are far greater than the safe limits that would allow pedestrian evacuation. A couple of alternative scenarios were also considered to investigate how such flood impacts could be mitigated by creating a mangrove belt in front of the dyke as an additional safety measure. The dyke-break-induced tsunamis, which in many areas are far more likely than regular earthquake tsunamis, cannot be overlooked and thus should be considered in disaster management and urban planning along the coasts of many developing countries.

Growth and development of spring towers at Shiqiang, Yunnan Province, China

NASA Astrophysics Data System (ADS)

Jones, Brian; Peng, Xiaotong

2017-01-01

Throughout the world, high artesian pressures in hydrothermal areas have led to the growth of tall spring towers that have their vents at their summits. The factors that control their development and formative precipitates are poorly understood because these springs, irrespective of location, are mostly inactive. Spring towers found at Shiqiang (Yunnan Province, China), which are up to 4 m high and 3 m in diameter, are formed largely of calcite and aragonite crystal bushes, euhedral calcite crystals and coated grains with alternating Fe-poor and Fe-rich zones, calcite rafts, and cements formed of various combinations of calcite, aragonite, strontianite, Mg-Si reticulate, needle fiber calcite, calcified and non-calcified microbes, diatoms, and insects. Collectively, the limestones that form the towers can be divided into (1) Group A that are friable, porous and form the cores of the towers and have δ18OSMOW values of + 15.7 to + 19.7‰ (average 17.8‰) and δ13CPDB values of + 5.1 to + 6.9‰ (average 5.9‰), and (2) Group B that are hard and well lithified and found largely around the vents and the tower sides, and have δ18OSMOW values of + 13.0 to + 22.0‰ (average 17.6‰) and δ13CPDB values of + 1.4 to + 3.6‰ (average 2.6‰). The precipitates and the isotopic values indicate that these were thermogene springs. Growth of the Shiqiang spring towers involved (1) Phase IA when precipitation of calcite and aragonite bushes formed the core of the tower and Phase IB when calcite, commonly Fe-rich, was precipitated locally, (2) Phase II that involved the precipitation of white cements, formed of calcite, aragonite, strontianite, and Mg-Si reticulate coatings in cavities amid the Phase I precipitates, and (3) Phase III, which formed probably after spring activity ceased, when needle-fiber calcite was precipitated and the mounds were invaded by microbes (some now calcified), diatoms, and insects. At various times during this complex history, pore waters mediated dissolution of the calcite and aragonite and sometimes partial alteration of the aragonite. The diverse array of precipitates, depositional fabrics and diagenetic changes clearly indicate that the composition of the spring water changed frequently. Growth of the spring towers at Shiqiang continued until there was insufficient artesian pressure to lift the water above the top of the tower vent.

Shelf spawning habitat of Emmelichthys nitidus in south-eastern Australia - Implications and suitability for egg-based biomass estimation

NASA Astrophysics Data System (ADS)

Neira, Francisco J.; Lyle, Jeremy M.; Keane, John P.

2009-03-01

The spawning habitat of Emmelichthys nitidus (Emmelichthyidae) in south-eastern Australia is described from vertical ichthyoplankton samples collected along the shelf region off eastern through to south-western Tasmania during peak spawning in October 2005-06. Surveys covered eastern waters in 2005 (38.8-43.5°S), and both eastern and southern waters in 2006 (40.5°S around to 43.5°S off the south-west). Eggs ( n = 10,393) and larvae ( n = 378) occurred along eastern Tasmania in both years but were rare along southern waters south and westwards of 43.5°S in 2006. Peak egg abundances (1950-2640 per m -2) were obtained off north-eastern Tasmania (40.5-41.5°S) between the shelf break and 2.5 nm inshore from the break. Eggs were up to 5-days old, while nearly 95% of larvae were at the early preflexion stage, i.e. close to newly emerged. Average abundances of aged eggs pooled across each survey declined steadily from day-1 to day-5 eggs both in 2005 (97-18) and 2006 (175-34). Moreover, day-1 egg abundances were significantly greater 2.5 nm at either side of the break, including at the break, than in waters ≥5 nm both inshore and offshore from the break. These results, complemented with egg and larval data obtained in shelf waters off New South Wales (NSW; 35.0-37.7°S) in October 2002-03, indicate that the main spawning area of E. nitidus in south-eastern Australia lies between 35.5°S off southern NSW and 43.5°S off south-eastern Tasmania, and that spawning activity declines abruptly south and westwards of 43.5°S around to the south-west coast. In addition, quotient analyses of day-1 egg abundances point to a preferred spawning habitat contained predominantly within a 5 nm corridor along the shelf break, where waters are 125-325 m deep and median temperatures 13.5-14.0 °C. Spawning off eastern Tasmania is timed with the productivity outburst typical of the region during the austral spring, and the temperature increase from the mixing between the southwards advancing, warm East Australian Current and cooler subantarctic water over the shelf. Overall, ichthyoplankton data, coupled with reproductive information from adults trawled off Tasmania, indicate that E. nitidus constitutes a suitable species for the application of the daily egg production method (DEPM) to estimate spawning biomass. This finding, together with evidence in support of a discrete eastern spawning stock extending from southern NSW to southern Tasmania, strengthens the need for DEPM-based biomass estimates of E. nitidus prior to further fishery expansion.

The potential for facilitating spring discharge from continental climate waste stabilisation ponds by carry-over of treated wastewater: concepts and experimental findings.

PubMed

Whalley, C; Pak, L N; Heaven, S

2007-01-01

The research investigated some factors influencing the rate of stabilisation of wastewater in the spring period in continental climate waste stabilisation ponds, and in particular the potential for bringing forward the discharge date by optimising storage capacity and dilution. Experiments using pilot and modelscale ponds were set up in Almaty, Kazakhstan. These simulated operating regimes for a facultative and storage/maturation pond system subject to ice cover from late November until late March. Two pilot-scale facultative ponds were operated at hydraulic retention times (HRT) of 20 and 30 days, with surface loading rates of 100 and 67 kg BOD ha(-1) day(-1). Effluent from the 20-day HRT facultative pond was then fed to two pilot-scale storage/maturation ponds which had been partially emptied and allowed to refill over the winter period with no removal of effluent. The paper discusses the results of the experiments with respect to selection of an operating regime to make treated wastewater available early in the spring. Preliminary results indicate that there may be potential for alternative operating protocols designed to maximise their performance and economic potential.

Mucous lysozyme levels in hatchery coho salmon (Oncorhynchus kisutch) and spring chinook salmon (O. tshawytscha) early in the parr-smolt transformation

USGS Publications Warehouse

Schrock, R.M.; Smith, S.D.; Maule, A.G.; Doulos, S.K.; Rockowski, J.J.

2001-01-01

Mucous lysozyme concentrations were determined in juvenile coho salmon (Oncorhynchus kisutch) and spring chinook salmon (O. tshawytscha) to establish reference levels during the time associated with the parr-smolt transformation. The first reported naris and vent mucous lysozyme levels are provided for spring chinook salmon and coho salmon. Naris mucous lysozyme levels ranged between 300 and 700 ??g ml-1, vent mucous lysozyme from 100 to 300 ??g ml-1, and skin mucous lysozyme levels were below 130 ??g ml-1. Lysozyme levels in the two species showed the same relationship with the highest levels in naris mucous, and the lowest in skin mucous. A seasonal decrease occurred in both species with a significant decrease in naris mucous lysozyme between February and March. Gill ATPase levels used to monitor smolt development during the same period did not reach ranges reported for smolts for either species during emigration. Identification of seasonal levels of lysozyme activity in mucous provides an alternative determination of developmental status prior to release of fish from the hatchery when salmonids are still undergoing the parr-smolt transformation. ?? 2001 Elsevier Science B.V.

Piezoelectric step-motion actuator

DOEpatents

Mentesana,; Charles, P [Leawood, KS

2006-10-10

A step-motion actuator using piezoelectric material to launch a flight mass which, in turn, actuates a drive pawl to progressively engage and drive a toothed wheel or rod to accomplish stepped motion. Thus, the piezoelectric material converts electrical energy into kinetic energy of the mass, and the drive pawl and toothed wheel or rod convert the kinetic energy of the mass into the desired rotary or linear stepped motion. A compression frame may be secured about the piezoelectric element and adapted to pre-compress the piezoelectric material so as to reduce tensile loads thereon. A return spring may be used to return the mass to its resting position against the compression frame or piezoelectric material following launch. Alternative embodiment are possible, including an alternative first embodiment wherein two masses are launched in substantially different directions, and an alternative second embodiment wherein the mass is eliminated in favor of the piezoelectric material launching itself.

Effects of urbanization on groundwater evolution in an urbanizing watershed

NASA Astrophysics Data System (ADS)

Reyes, D.; Banner, J. L.; Bendik, N.

2011-12-01

The Jollyville Plateau Salamander (Eurycea tonkawae), a candidate species for listing under the Endangered Species Act, is endemic to springs and caves within the Bull Creek Watershed of Austin, Texas. Rapid urbanization endangers known populations of this salamander. Conservation strategies lack information on the extent of groundwater contamination from anthropogenic sources in this karst watershed. Spring water was analyzed for strontium (Sr) isotopes and major ions from sites classified as "urban" or "rural" based on impervious cover estimates. Previous studies have shown that the 87Sr/86Sr value of municipal water is significantly higher than values for natural streamwater, which are similar to those for the Cretaceous limestone bedrock of the region's watersheds. We investigate the application of this relationship to understanding the effects of urbanization on groundwater quality. The use of Sr isotopes as hydrochemical tracers is complemented by major ion concentrations, specifically the dominant ions in natural groundwater (Ca and HCO3) and the ions associated with the addition of wastewater (Na and Cl). To identify high priority salamander-inhabited springs for water quality remediation, we explore the processes controlling the chemical evolution of groundwater such as municipal water inputs, groundwater-soil interactions, and solution/dissolution reactions. 87Sr/86Sr values for water samples from within the watershed range from 0.70760 to 0.70875, the highest values corresponding to sites located in the urbanized areas of the watershed. Analyses of the covariation of Sr isotopes with major ion concentrations help elucidate controls on spring water evolution. Springs located in rural portions of the watershed have low 87Sr/86Sr, high concentrations of Ca and HCO3, and low concentrations of Na and Cl. This is consistent with small inputs of municipal water. Three springs located in urban portions of the watershed have high 87Sr/86Sr, low Ca and HCO3, and high Na and Cl. This is consistent with large inputs of municipal water. The other five springs located in urban portions have low 87Sr/86Sr, low concentrations of Ca and HCO3, and high concentrations of Na and Cl. This is reflects a process other than an input of municipal water. Groundwater interaction with soils generally results in higher Na concentrations relative to Ca. 87Sr/86Sr values in this scenario may increase or decrease, depending on the Sr isotope variability of the local soils. Alternatively, precipitation of calcite from groundwater would decrease the concentration of Ca without necessarily decreasing 87Sr/86Sr values. The results suggest more anthropogenic water in urban springs than rural springs. These data serve to identify sources of spring recharge, including better constraints on the location(s) of urban leakage.

Interbasin flow in the Great Basin with special reference to the southern Funeral Mountains and the source of Furnace Creek springs, Death Valley, California, U.S.

USGS Publications Warehouse

Belcher, W.R.; Bedinger, M.S.; Back, J.T.; Sweetkind, D.S.

2009-01-01

Interbasin flow in the Great Basin has been established by scientific studies during the past century. While not occurring uniformly between all basins, its occurrence is common and is a function of the hydraulic gradient between basins and hydraulic conductivity of the intervening rocks. The Furnace Creek springs in Death Valley, California are an example of large volume springs that are widely accepted as being the discharge points of regional interbasin flow. The flow path has been interpreted historically to be through consolidated Paleozoic carbonate rocks in the southern Funeral Mountains. This work reviews the preponderance of evidence supporting the concept of interbasin flow in the Death Valley region and the Great Basin and addresses the conceptual model of pluvial and recent recharge [Nelson, S.T., Anderson, K., Mayo, A.L., 2004. Testing the interbasin flow hypothesis at Death Valley, California. EOS 85, 349; Anderson, K., Nelson, S., Mayo, A., Tingey, D., 2006. Interbasin flow revisited: the contribution of local recharge to high-discharge springs, Death Valley, California. Journal of Hydrology 323, 276-302] as the source of the Furnace Creek springs. We find that there is insufficient modern recharge and insufficient storage potential and permeability within the basin-fill units in the Furnace Creek basin for these to serve as a local aquifer. Further, the lack of high sulfate content in the spring waters argues against significant flow through basin-fill sediments and instead suggests flow through underlying consolidated carbonate rocks. The maximum temperature of the spring discharge appears to require deep circulation through consolidated rocks; the Tertiary basin fill is of insufficient thickness to generate such temperatures as a result of local fluid circulation. Finally, the stable isotope data and chemical mass balance modeling actually support the interbasin flow conceptual model rather than the alternative presented in Nelson et al. [Nelson, S.T., Anderson, K., Mayo, A.L., 2004. Testing the interbasin flow hypothesis at Death Valley, California. EOS 85, 349] and Anderson et al. [Anderson, K., Nelson, S., Mayo, A., Tingey, D., 2006. Interbasin flow revisited: the contribution of local recharge to high-discharge springs, Death Valley, California. Journal of Hydrology 323, 276-302]. In light of these inconsistencies, interbasin flow is the only readily apparent explanation for the large spring discharges at Furnace Creek and, in our view, is the likely explanation for most large volume, low elevation springs in the Great Basin. An understanding of hydrogeologic processes that control the rate and direction of ground-water flow in eastern and central Nevada is necessary component of regional water-resource planning and management of alluvial and bedrock aquifers.

OutKnocker: a web tool for rapid and simple genotyping of designer nuclease edited cell lines.

PubMed

Schmid-Burgk, Jonathan L; Schmidt, Tobias; Gaidt, Moritz M; Pelka, Karin; Latz, Eicke; Ebert, Thomas S; Hornung, Veit

2014-10-01

The application of designer nucleases allows the induction of DNA double-strand breaks (DSBs) at user-defined genomic loci. Due to imperfect DNA repair mechanisms, DSBs can lead to alterations in the genomic architecture, such as the disruption of the reading frame of a critical exon. This can be exploited to generate somatic knockout cell lines. While high genome editing activities can be achieved in various cellular systems, obtaining cell clones that contain all-allelic frameshift mutations at the target locus of interest remains a laborious task. To this end, we have developed an easy-to-follow deep sequencing workflow and the evaluation tool OutKnocker (www.OutKnocker.org), which allows convenient, reliable, and cost-effective identification of knockout cell lines. © 2014 Schmid-Burgk et al.; Published by Cold Spring Harbor Laboratory Press.

Characterizing fate and transport properties in karst aquifers under different hydrologic conditions

NASA Astrophysics Data System (ADS)

Rodriguez, E.; Padilla, I. Y.

2017-12-01

Karst landscapes contain very productive aquifers. The hydraulic and hydrogeological characteristics of karst aquifers make these systems capable of storing and transporting large amount of water, but also highly vulnerable to contamination. Their extremely heterogeneous nature prevents accurate prediction in contaminant fate and transport. Even more challenging is to understand the impact of hydrologic conditions changes on fate and transport processes. This studies aims at characterizing fate and transport processes in the karst groundwater system of northern Puerto Rico under different hydrologic conditions. The study involves injecting rhodamine and uranine dyes into a sinkhole, and monitoring concentrations at a spring. Results show incomplete recovery of tracers, but breaking curves can be used to estimate advective, dispersive and mass transfer characteristic of the karst system. Preliminary results suggest significant differences in fate and transport characteristics under different hydrologic conditions.

Dancing with the Tides: Fluctuations of Coastal Phytoplankton Orchestrated by Different Oscillatory Modes of the Tidal Cycle

PubMed Central

Blauw, Anouk N.; Benincà, Elisa; Laane, Remi W. P. M.; Greenwood, Naomi; Huisman, Jef

2012-01-01

Population fluctuations are often driven by an interplay between intrinsic population processes and extrinsic environmental forcing. To investigate this interplay, we analyzed fluctuations in coastal phytoplankton concentration in relation to the tidal cycle. Time series of chlorophyll fluorescence, suspended particulate matter (SPM), salinity and temperature were obtained from an automated measuring platform in the southern North Sea, covering 9 years of data at a resolution of 12 to 30 minutes. Wavelet analysis showed that chlorophyll fluctuations were dominated by periodicities of 6 hours 12 min, 12 hours 25 min, 24 hours and 15 days, which correspond to the typical periodicities of tidal current speeds, the semidiurnal tidal cycle, the day-night cycle, and the spring-neap tidal cycle, respectively. During most of the year, chlorophyll and SPM fluctuated in phase with tidal current speed, indicative of alternating periods of sinking and vertical mixing of algal cells and SPM driven by the tidal cycle. Spring blooms slowly built up over several spring-neap tidal cycles, and subsequently expanded in late spring when a strong decline of the SPM concentration during neap tide enabled a temporary “escape” of the chlorophyll concentration from the tidal mixing regime. Our results demonstrate that the tidal cycle is a major determinant of phytoplankton fluctuations at several different time scales. These findings imply that high-resolution monitoring programs are essential to capture the natural variability of phytoplankton in coastal waters. PMID:23166639

Dancing with the tides: fluctuations of coastal phytoplankton orchestrated by different oscillatory modes of the tidal cycle.

PubMed

Blauw, Anouk N; Benincà, Elisa; Laane, Remi W P M; Greenwood, Naomi; Huisman, Jef

2012-01-01

Population fluctuations are often driven by an interplay between intrinsic population processes and extrinsic environmental forcing. To investigate this interplay, we analyzed fluctuations in coastal phytoplankton concentration in relation to the tidal cycle. Time series of chlorophyll fluorescence, suspended particulate matter (SPM), salinity and temperature were obtained from an automated measuring platform in the southern North Sea, covering 9 years of data at a resolution of 12 to 30 minutes. Wavelet analysis showed that chlorophyll fluctuations were dominated by periodicities of 6 hours 12 min, 12 hours 25 min, 24 hours and 15 days, which correspond to the typical periodicities of tidal current speeds, the semidiurnal tidal cycle, the day-night cycle, and the spring-neap tidal cycle, respectively. During most of the year, chlorophyll and SPM fluctuated in phase with tidal current speed, indicative of alternating periods of sinking and vertical mixing of algal cells and SPM driven by the tidal cycle. Spring blooms slowly built up over several spring-neap tidal cycles, and subsequently expanded in late spring when a strong decline of the SPM concentration during neap tide enabled a temporary "escape" of the chlorophyll concentration from the tidal mixing regime. Our results demonstrate that the tidal cycle is a major determinant of phytoplankton fluctuations at several different time scales. These findings imply that high-resolution monitoring programs are essential to capture the natural variability of phytoplankton in coastal waters.

Superconducting gravimeters reveal unprecedented details of changes related to volcanic processes

NASA Astrophysics Data System (ADS)

Carbone, Daniele; Greco, Filippo; Cannavò, Flavio

2017-04-01

Continuous gravity measurements have been successfully carried out at a number of volcanoes around the world using spring gravimeters. Nevertheless, these instruments do not provide reliable measurements when used in continuous mode for weeks or more, because they are influenced by environmental factors and are subject to instrumental drift. Accordingly, most studies of continuous gravity at active volcanoes have focused on the analysis of changes over time-scales of minutes to a few days. An alternative to spring gravimeters for continuous measurements is given by superconducting gravimeters (SGs) that feature a much higher precision and stability than spring gravimeters. However, even the most portable SGs (e.g., the iGrav® by GWR) are not ideal for installation in the vicinity of active volcanic structures. Indeed, they require AC power at the installation site and some kind of hut or vault to house the instrumentation. At Mt. Etna, the installation of a mini-array of three SGs (distances of 3.5 to 15.5 km from the active craters) was begun in September 2014. To our knowledge, these are the first SGs ever installed on an active volcano. Signals from these instruments show hydrologically-induced components superimposed on small (a few microGal) gravity changes that are related to volcanic processes. Such changes, occurring over periods of minutes to weeks, would not be observable by spring gravimeters due to their intrinsic limitations regarding precision and long-term stability.

Using larval fish community structure to guide long-term monitoring of fish spawning activity

USGS Publications Warehouse

Pritt, Jeremy J.; Roseman, Edward F.; Ross, Jason E.; DeBruyne, Robin L.

2015-01-01

Larval fishes provide a direct indication of spawning activity and may therefore be useful for long-term monitoring efforts in relation to spawning habitat restoration. However, larval fish sampling can be time intensive and costly. We sought to understand the spatial and temporal structure of larval fish communities in the St. Clair–Detroit River system, Michigan–Ontario, to determine whether targeted larval fish sampling can be made more efficient for long-term monitoring. We found that larval fish communities were highly nested, with lower river segments and late-spring samples containing the highest genus richness of larval fish. We created four sampling scenarios for each river system: (1) using all available data, (2) limiting temporal sampling to late spring, (3) limiting spatial sampling to lower river segments only, and (4) limiting both spatial and temporal sampling. By limiting the spatial extent of sampling to lower river sites and/or limiting the temporal extent to the late-spring period, we found that effort could be reduced by more than 50% while maintaining over 75% of the observed and estimated total genus richness. Similarly, limiting the sampling effort to lower river sites and/or the late-spring period maintained between 65% and 93% of the observed richness of lithophilic-spawning genera and invasive genera. In general, community composition remained consistent among sampling scenarios. Targeted sampling offers a lower-cost alternative to exhaustive spatial and temporal sampling and may be more readily incorporated into long-term monitoring.

Geophysical investigations of the geologic and hydrothermal framework of the Pilgrim Springs Geothermal Area, Alaska

USGS Publications Warehouse

Glen, Jonathan; McPhee, Darcy K.; Bedrosian, Paul A.

2014-01-01

Pilgrim Hot Springs, located on the Seward Peninsula in west-central Alaska, is characterized by hot springs, surrounding thawed regions, and elevated lake temperatures. The area is of interest because of its potential for providing renewable energy for Nome and nearby rural communities. We performed ground and airborne geophysical investigations of the Pilgrim Springs geothermal area to identify areas indicative of high heat flow and saline geothermal fluids, and to map key structures controlling hydrothermal fluid flow. Studies included ground gravity and magnetic measurements, as well as an airborne magnetic and frequency-domain electromagnetic (EM) survey. The structural and conceptual framework developed from this study provides critical information for future development of this resource and is relevant more generally to our understanding of geothermal systems in active extensional basins. Potential field data reveal the Pilgrim area displays a complex geophysical fabric reflecting a network of intersecting fault and fracture sets ranging from inherited basement structures to Tertiary faults. Resistivity models derived from the airborne EM data reveal resistivity anomalies in the upper 100 m of the subsurface that suggest elevated temperatures and the presence of saline fluids. A northwest trending fabric across the northeastern portion of the survey area parallels structures to the east that may be related to accommodation between the two major mountain ranges south (Kigluaik) and east (Bendeleben) of Pilgrim Springs. The area from the springs southward to the range front, however, is characterized by east-west trending, range-front-parallel anomalies likely caused by late Cenozoic structures associated with north-south extension that formed the basin. The area around the springs (~10 km2 ) is coincident with a circular magnetic high punctuated by several east-west trending magnetic lows, the most prominent occurring directly over the springs. These features possibly result from hydrothermal alteration imposed by fluids migrating along intra-basin faults related to recent north-south extension. The Pilgrim River valley is characterized by a NE-elongate gravity low that reveals a basin extending to depths of ~300 m beneath Pilgrim Springs and deepening to ~800 m to the southwest. The margins of the gravity low are sharply defined by northeasttrending gradients that probably reflect the edges of fault-bounded structural blocks. The southeastern edge of the low, which lies very close to the springs, also corresponds with prominent NE-striking anomalies seen in magnetic and resistivity models. Together, these features define a structure we refer to as the Northeast Fault. The location of the hot springs appears to be related to the intersection of the Northeast Fault with a N-oriented structure marked by the abrupt western edge of a resistivity low surrounding the hot springs. While the hot springs represent the primary outflow of geothermal fluids, additional outflow extends from the springs northeast along the Northeast fault to another thaw zone that we interpret to be a secondary region of concentrated upflow of geothermal fluids. The Northeast Fault apparently controls shallow geothermal fluid flow, and may also provide an important pathway conveying deep fluids to the shallow subsurface. We suggest that geothermal fluids may derive from a reservoir residing beneath the sediment basin southwest of the springs. If so, the shape of the basin, which narrows and shallows towards the springs, may funnel fluids beneath the springs where they intersect the Northeast Fault allowing them to reach the surface. An alternative pathway for reservoir fluids to reach intermediate to shallow depths may be afforded by the main Kigluaik range front fault that coincides with a resistivity anomaly possibly resulting from fluid flow and associated hydrothermal mineralization occurring within the fault zone.

A mixability theory for the role of sex in evolution

PubMed Central

Livnat, Adi; Papadimitriou, Christos; Dushoff, Jonathan; Feldman, Marcus W.

2008-01-01

The question of what role sex plays in evolution is still open despite decades of research. It has often been assumed that sex should facilitate the increase in fitness. Hence, the fact that it may break down highly favorable genetic combinations has been seen as a problem. Here, we consider an alternative approach. We define a measure that represents the ability of alleles to perform well across different combinations and, using numerical iterations within a classical population-genetic framework, show that selection in the presence of sex favors this ability in a highly robust manner. We also show that the mechanism responsible for this effect has been out of the purview of previous theory, because it operates during the evolutionary transient, and that the breaking down of favorable genetic combinations is an integral part of it. Implications of these results and more to evolutionary theory are discussed. PMID:19073912

A mixability theory for the role of sex in evolution.

PubMed

Livnat, Adi; Papadimitriou, Christos; Dushoff, Jonathan; Feldman, Marcus W

2008-12-16

The question of what role sex plays in evolution is still open despite decades of research. It has often been assumed that sex should facilitate the increase in fitness. Hence, the fact that it may break down highly favorable genetic combinations has been seen as a problem. Here, we consider an alternative approach. We define a measure that represents the ability of alleles to perform well across different combinations and, using numerical iterations within a classical population-genetic framework, show that selection in the presence of sex favors this ability in a highly robust manner. We also show that the mechanism responsible for this effect has been out of the purview of previous theory, because it operates during the evolutionary transient, and that the breaking down of favorable genetic combinations is an integral part of it. Implications of these results and more to evolutionary theory are discussed.

Neutrino masses and leptogenesis in left-right symmetric models: a review from a model building perspective

NASA Astrophysics Data System (ADS)

Hati, Chandan; Patra, Sudhanwa; Pritimita, Prativa; Sarkar, Utpal

2018-03-01

In this review, we present several variants of left-right symmetric models in the context of neutrino masses and leptogenesis. In particular, we discuss various low scale seesaw mechanisms like linear seesaw, inverse seesaw, extended seesaw and their implications to lepton number violating process like neutrinoless double beta decay. We also visit an alternative framework of left-right models with the inclusion of vector-like fermions to analyze the aspects of universal seesaw. The symmetry breaking of left-right symmetric model around few TeV scale predicts the existence of massive right-handed gauge bosons W_R and Z_R which might be detected at the LHC in near future. If such signals are detected at the LHC that can have severe implications for leptogenesis, a mechanism to explain the observed baryon asymmetry of the Universe. We review the implications of TeV scale left-right symmetry breaking for leptogenesis.

Nonreciprocity and magnetic-free isolation based on optomechanical interactions

PubMed Central

Ruesink, Freek; Miri, Mohammad-Ali; Alù, Andrea; Verhagen, Ewold

2016-01-01

Nonreciprocal components, such as isolators and circulators, provide highly desirable functionalities for optical circuitry. This motivates the active investigation of mechanisms that break reciprocity, and pose alternatives to magneto-optic effects in on-chip systems. In this work, we use optomechanical interactions to strongly break reciprocity in a compact system. We derive minimal requirements to create nonreciprocity in a wide class of systems that couple two optical modes to a mechanical mode, highlighting the importance of optically biasing the modes at a controlled phase difference. We realize these principles in a silica microtoroid optomechanical resonator and use quantitative heterodyne spectroscopy to demonstrate up to 10 dB optical isolation at telecom wavelengths. We show that nonreciprocal transmission is preserved for nondegenerate modes, and demonstrate nonreciprocal parametric amplification. These results open a route to exploiting various nonreciprocal effects in optomechanical systems in different electromagnetic and mechanical frequency regimes, including optomechanical metamaterials with topologically non-trivial properties. PMID:27897165

Retributive and restorative justice.

PubMed

Wenzel, Michael; Okimoto, Tyler G; Feather, Norman T; Platow, Michael J

2008-10-01

The emergence of restorative justice as an alternative model to Western, court-based criminal justice may have important implications for the psychology of justice. It is proposed that two different notions of justice affect responses to rule-breaking: restorative and retributive justice. Retributive justice essentially refers to the repair of justice through unilateral imposition of punishment, whereas restorative justice means the repair of justice through reaffirming a shared value-consensus in a bilateral process. Among the symbolic implications of transgressions, concerns about status and power are primarily related to retributive justice and concerns about shared values are primarily related to restorative justice. At the core of these processes, however, lies the parties' construal of their identity relation, specifically whether or not respondents perceive to share an identity with the offender. The specific case of intergroup transgressions is discussed, as are implications for future research on restoring a sense of justice after rule-breaking.

Chasing the Garlock: A study of tectonic response to vertical axis rotation

NASA Astrophysics Data System (ADS)

Guest, Bernard; Pavlis, Terry L.; Golding, Heather; Serpa, Laura

2003-06-01

Vertical-axis, clockwise block rotations in the Northeast Mojave block are well documented by numerous authors. However, the effects of these rotations on the crust to the north of the Northeast Mojave block have remained unexplored. In this paper we present a model that results from mapping and geochronology conducted in the north and central Owlshead Mountains. The model suggests that some or all of the transtension and rotation observed in the Owlshead Mountains results from tectonic response to a combination of clockwise block rotation in the Northeast Mojave block and Basin and Range extension. The Owlshead Mountains are effectively an accommodation zone that buffers differential extension between the Northeast Mojave block and the Basin and Range. In addition, our model explores the complex interactions that occur between faults and fault blocks at the junction of the Garlock, Brown Mountain, and Owl Lake faults. We hypothesize that the bending of the Garlock fault by rotation of the Northeast Mojave block resulted in a misorientation of the Garlock that forced the Owl Lake fault to break in order to accommodate slip on the western Garlock fault. Subsequent sinistral slip on the Owl Lake fault offset the Garlock, creating the now possibly inactive Mule Springs strand of the Garlock fault. Dextral slip on the Brown Mountain fault then locked the Owl Lake fault, forcing the active Leach Lake strand of the Garlock fault to break.

A possible cause of the AO polarity reversal from winter to summer in 2010 and its relation to hemispheric extreme summer weather

NASA Astrophysics Data System (ADS)

Otomi, Yuriko; Tachibana, Yoshihiro; Nakamura, Tetsu

2013-04-01

In 2010, the Northern Hemisphere, in particular Russia and Japan, experienced an abnormally hot summer characterized by record-breaking warm temperatures and associated with a strongly positive Arctic Oscillation (AO), that is, low pressure in the Arctic and high pressure in the midlatitudes. In contrast, the AO index the previous winter and spring (2009/2010) was record-breaking negative. The AO polarity reversal that began in summer 2010 can explain the abnormally hot summer. The winter sea surface temperatures (SST) in the North Atlantic Ocean showed a tripolar anomaly pattern—warm SST anomalies over the tropics and high latitudes and cold SST anomalies over the midlatitudes—under the influence of the negative AO. The warm SST anomalies continued into summer 2010 because of the large oceanic heat capacity. A model simulation strongly suggested that the AO-related summertime North Atlantic oceanic warm temperature anomalies remotely caused blocking highs to form over Europe, which amplified the positive summertime AO. Thus, a possible cause of the AO polarity reversal might be the "memory" of the negative winter AO in the North Atlantic Ocean, suggesting an interseasonal linkage of the AO in which the oceanic memory of a wintertime negative AO induces a positive AO in the following summer. Understanding of this interseasonal linkage may aid in the long-term prediction of such abnormal summer events.

A possible cause of the AO polarity reversal from winter to summer in 2010 and its relation to hemispheric extreme hot summer

NASA Astrophysics Data System (ADS)

Tachibana, Yoshihiro; Otomi, Yuriko; Nakamura, Tetsu

2013-04-01

In 2010, the Northern Hemisphere, in particular Russia and Japan, experienced an abnormally hot summer characterized by record-breaking warm temperatures and associated with a strongly positive Arctic Oscillation (AO), that is, low pressure in the Arctic and high pressure in the midlatitudes. In contrast, the AO index the previous winter and spring (2009/2010) was record-breaking negative. The AO polarity reversal that began in summer 2010 can explain the abnormally hot summer. The winter sea surface temperatures (SST) in the North Atlantic Ocean showed a tripolar anomaly pattern—warm SST anomalies over the tropics and high latitudes and cold SST anomalies over the midlatitudes—under the influence of the negative AO. The warm SST anomalies continued into summer 2010 because of the large oceanic heat capacity. A model simulation strongly suggested that the AO-related summertime North Atlantic oceanic warm temperature anomalies remotely caused blocking highs to form over Europe, which amplified the positive summertime AO. Thus, a possible cause of the AO polarity reversal might be the "memory" of the negative winter AO in the North Atlantic Ocean, suggesting an interseasonal linkage of the AO in which the oceanic memory of a wintertime negative AO induces a positive AO in the following summer. Understanding of this interseasonal linkage may aid in the long-term prediction of such abnormal summer events.

Contrasting subtropical PV intrusion frequency and their impact on tropospheric Ozone distribution over Pacific Ocean in El-Niño and La-Niña conditions.

PubMed

Nath, Debashis; Chen, Wen; Graf, Hans-F; Lan, Xiaoqiang; Gong, Hainan

2017-09-20

Upper tropospheric equatorial westerly ducts over the Pacific Ocean are the preferred location for Rossby wave breaking events during boreal winter and spring. These subtropical wave breaking events lead to the intrusion of high PV (potential vorticity) air along the extra-tropical tropopause and transport ozone rich dry stratospheric air into the tropics. The intrusion frequency has strong interannual variability due to ENSO (El-Niño/Southern Oscillation), with more events under La-Niña and less under El-Niño conditions. This may result from stronger equatorial westerly ducts and subtropical jets during La-Niña and weaker during El-Niño. It was previously suggested that the interannual variability of the tropospheric ozone distribution over the central-eastern Pacific Ocean is mainly driven by convective activity related to ENSO and that the barotropic nature of the subtropical intrusions restricts the tracers within the UT. However, our analysis shows that tropospheric ozone concentration and subtropical intrusions account ~65% of the co- variability (below 5 km) in the outer tropical (10-25°N) central Pacific Ocean, particularly during La-Niña conditions. Additionally, we find a two-fold increase and westward shift in the intrusion frequency over the Pacific Ocean, due to the climate regime shift in SST pattern during 1997/98.

Future summer mega-heatwave and record-breaking temperatures in a warmer France climate

NASA Astrophysics Data System (ADS)

Bador, Margot; Terray, Laurent; Boé, Julien; Somot, Samuel; Alias, Antoinette; Gibelin, Anne-Laure; Dubuisson, Brigitte

2017-07-01

This study focuses on future very hot summers associated with severe heatwaves and record-breaking temperatures in France. Daily temperature observations and a pair of historical and scenario (greenhouse gas radiative concentration pathway 8.5) simulations with the high-resolution (∼12.5 km) ALADIN regional climate model provide a robust framework to examine the spatial distribution of these extreme events and their 21st century evolution. Five regions are identified with an extreme event spatial clustering algorithm applied to observed temperatures. They are used to diagnose the 21st century heatwave spatial patterns. In the 2070s, we find a simulated mega-heatwave as severe as the 2003 observed heatwave relative to its contemporaneous climate. A 20-member initial condition ensemble is used to assess the sensitivity of this future heatwave to the internal variability in the regional climate model and to pre-existing land surface conditions. Even in a much warmer and drier climate in France, late spring dry land conditions may lead to a significant amplification of summer extreme temperatures and heatwave intensity through limitations in evapotranspiration. By 2100, the increase in summer temperature maxima exhibits a range from 6 °C to almost 13 °C in the five regions in France, relative to historical maxima. These projections are comparable with the estimates given by a large number of global climate models.

Spring Ankle with Regenerative Kinetics to Build a New Generation of Transtibial Prostheses

DTIC Science & Technology

2009-07-01

fiber keel. This feature can provide an alternative if the electronics fail in a field condition. We are focused on developing the most durable...step forward in design of new prosthesis 22 14. Discovery Channel, 2008, “Toad research could leapfrog to new muscle model”, show was called...turning on the proportional myoelectric control. The pneumatic muscles supplied 36% plantar flexor torque and 123% dorsi flexor torque. Challenges

A new concept for actuating space mechanisms. [for the Mariner Jupiter-Saturn spacecraft magnetometer

NASA Technical Reports Server (NTRS)

Stange, W. C.

1975-01-01

A two position (0 and 180 deg) actuating mechanism driven by two alternately heated opposing flat NITINOL springs is proposed for rotating the low field triaxial fluxgate magnetometer experiment on the 1977 Mariner Jupiter-Saturn spacecraft to its 0 deg and 180 deg positions. The magnetic field, power requirements, weight, and volume of this device are very restrictive. The problems encountered in design and development are presented.

Proceedings of the Symposium on Psychology in the Department of Defense (11th) Held in Colorado Springs, Colorado on 13-15 April 1988

DTIC Science & Technology

1988-04-15

participatory methods and organization-wide change. This program appears to be well managed by those who understand and accept the strategies and values of...many alternative management strategies , including participatory approaches, to improve product quality, productivity, and quality of work life (Brown...PRESENT, AND FUTJRE" Leslie Wilson Mickey Dansby Dan Landis Defense Equal Opportunity Management Institute ........ ....................... ... 54

Air and Space Power Journal. Volume 18, Number 1, Spring 2004

DTIC Science & Technology

2004-01-01

throughput (coatings, etc.) Thermal management Integrated power , energy, and thermal management Target link Passive tracking and pointing Active...facet of the alternate-energy equa­ tion. In 2002, capacities of 3 MW of station­ ary power evolved but only to the point where it was economically...engine-performance requirements, but also its energy content is so high and flash point so low that it becomes the standard for auxiliary- power

Remote sensing application possibilities on groundwater characterization in arid regions at the example of the Dead Sea

NASA Astrophysics Data System (ADS)

Mallast, U.; Siebert, C.; Gloaguen, R.; Wagner, B.; Schwonke, F.; Rödiger, T.; Geyer, S.; Krieg, R.; Sauter, M.; Kühn, F.; Merz, R.

2012-04-01

In arid regions like the Dead Sea (DS) water supply mostly relies on restricted groundwater resources, which are in many cases defined by large inaccessible areas with scarce in-situ data. However, particularly in these regions it is essential to obtain detailed information of this precious resource in order to develop a sustainable water management - one of the main aims of the BMBF-funded multilateral SUMAR (Sustainable Management of Arid and Semiarid Regions) project. The usage of remote sensing offers different indicators and directly sensed patterns from different platforms providing important data where practical alternatives or simply spatial data are not available (Becker, 2006). One application possibility regards the identification of lineaments which are simple or composite linear features of a surface and which have been proven to reflect general groundwater flow-paths (Sander, 1997). In a previous study we derived lineaments using a freely available digital elevation model (30 m spatial resolution) and developed a semi-automatic approach composed of low pass and 2nd order Laplace linear filtering and a subsequent object based classification. Based on these lineaments we could identify general groundwater flow-paths with striking directional trends towards known spring areas along the DS (Mallast et al., 2011). With the knowledge of both, location of spring areas and a given temperature contrast between ground- and DS water, we derived by using thermal remote sensing from satellite and airborne platforms a second application possibility. Satellite based thermal remote sensing with Landsat ETM+ images allowed us to identify groundwater discharge pattern, which highly correlate in location with the previously derived flow-paths, but also enabled us to relatively quantify also seasonal varying groundwater discharge over a time period of 12 years (2000-2011). The drawback remains in the spatial resolution of 30 m (resampled from United States Geological Survey from 60 m), which hinders to accurately delineate spring-caused thermal plumes or to identify small scale springs or even spring types (terrestrial springs and submarine springs) (Mallast et al., 2012). As exactly this fact is important for subsequent studies we pursued an airborne thermal campaign in January, 2011 where technical specifications (0.5 m spatial resolution, flight time at night for higher contrast) were chosen to account for any so far observed spring type and scale. The result confirms the delineated areas from the satellite findings but refines these areas showing numerous and differentiable discharge locations. It also reveals unknown submarine spring locations and a third spring type where groundwater diffusely seeps through high saline Dead Sea sediments in contrast to the other spring types, with rather concentrated flow. The study shows at two application examples how remote sensing can be used for groundwater studies and also points at related advantages and disadvantages. Integrating these information into numerical groundwater modelling or sustainable water management strategies can significantly improve existing approaches and hence, yields a valuable benefits.

A simulation analysis of the fate of phytoplankton within the mid-Atlantic bight

NASA Technical Reports Server (NTRS)

Walsh, J. J.; Dieterle, D. A.; Meyers, M. B.

1986-01-01

A time-dependent, three-dimensional simulation model of wind-induced changes of the circulation field, of light and nutrient regulation of photosynthesis, of vertical mixing as well as algal sinking, and of herbivore grazing stress, is used to analyze the seasonal production, consumption, and transport of the spring bloom within the mid-Atlantic Bight. The particular case (c) of a 58-day period in February-April 1979, simulated primary production, based on both nitrate and recycled nitrogen, with a mean of 0.62 g C sq m/day over the whole model domain, and an export at the shelf-break off Long Island of 2.60 g ch1 sq m/day within the lower third of the water column. About 57% of the carbon fixation was removed by herbivores, with 21% lost as export, either downshelf or offshore to slope waters, after the first 58 days of the spring bloom. Extension of the model for another 22 days of case (c) increased the mean export to 27%, while variation of the model's parameters in 8 other cases led to a range in export from 8% to 38% of the average primary production. Spatial and temporal variations of the simulated albal biomass, left behind in the shelf water column, reproduced chlorophyll fields sensed by satellite, shipboard, and in situ instruments.

Inducing rye 1R chromosome structural changes in common wheat cv. Chinese spring by the gametocidal chromosome 2C of Aegilops cylindrica.

PubMed

Shi, Fang; Liu, Kun-Fan; Endo, Takashi R; Wang, Dao-Wen

2005-05-01

To generate 1 R deletion and translocation lines, we introduced a 2C chromosome,which was derived from Aegilops cylindrica and was known to have a gametocidal function when added monosomically into common wheat cv. Chinese Spring (CS) and its derivative, into a wheat-rye 1R chromosome disomic addition line (CS-1R"). When the individuals with chromosome constitution 21" + 1R" + 2C' (2n = 45) were selfed, the 1R chromosome structural changes were found to be induced with high frequency (24.1%) among the progenies. By using C-banding and GISH analysis, we analyzed 1R structural changes in 46 F3 individuals, which came from 23 F2 plants. The rearranged 1R chromosomes could be characterized in about 85% of the F3 individuals. This included telosome 1RL (39.1%), iso-chromosome 1 RL (2.2%), whole arm translocation involving 1RL (32.6%), telosome 1RS (4.3%), iso-chromosome 1RS (4.3%), and 1R deletion mutant with break point in the long arm (2.2%). The mutant 1R lines obtained in this study will potentially be useful in mapping the chromosome locations of agronomically important genes located in 1R. This study also demonstrated that molecular markers might be used to identify wheat chromosome arm involved in translocation with 1R.

Steady-state propagation speed of rupture fronts along one-dimensional frictional interfaces.

PubMed

Amundsen, David Skålid; Trømborg, Jørgen Kjoshagen; Thøgersen, Kjetil; Katzav, Eytan; Malthe-Sørenssen, Anders; Scheibert, Julien

2015-09-01

The rupture of dry frictional interfaces occurs through the propagation of fronts breaking the contacts at the interface. Recent experiments have shown that the velocities of these rupture fronts range from quasistatic velocities proportional to the external loading rate to velocities larger than the shear wave speed. The way system parameters influence front speed is still poorly understood. Here we study steady-state rupture propagation in a one-dimensional (1D) spring-block model of an extended frictional interface for various friction laws. With the classical Amontons-Coulomb friction law, we derive a closed-form expression for the steady-state rupture velocity as a function of the interfacial shear stress just prior to rupture. We then consider an additional shear stiffness of the interface and show that the softer the interface, the slower the rupture fronts. We provide an approximate closed form expression for this effect. We finally show that adding a bulk viscosity on the relative motion of blocks accelerates steady-state rupture fronts and we give an approximate expression for this effect. We demonstrate that the 1D results are qualitatively valid in 2D. Our results provide insights into the qualitative role of various key parameters of a frictional interface on its rupture dynamics. They will be useful to better understand the many systems in which spring-block models have proved adequate, from friction to granular matter and earthquake dynamics.

Phase-change lines, scale breaks, and trend lines using Excel 2013.

PubMed

Deochand, Neil; Costello, Mack S; Fuqua, R Wayne

2015-01-01

The development of graphing skills for behavior analysts is an ongoing process. Specialized graphing software is often expensive, is not widely disseminated, and may require specific training. Dixon et al. (2009) provided an updated task analysis for graph making in the widely used platform Excel 2007. Vanselow and Bourret (2012) provided online tutorials that outline some alternate methods also using Office 2007. This article serves as an update to those task analyses and includes some alternative and underutilized methods in Excel 2013. To examine the utility of our recommendations, 12 psychology graduate students were presented with the task analyses, and the experimenters evaluated their performance and noted feedback. The task analyses were rated favorably. © Society for the Experimental Analysis of Behavior.

Electrohydrodynamic (EHD) stimulation of jet breakup

NASA Technical Reports Server (NTRS)

Crowley, J. M.

1982-01-01

Electrohydrodynamic (EHD) excitation of liquid jets offers an alternative to piezoelectric excitation without the complex frequency response caused by piezoelectric and mechanical resonances. In an EHD exciter, an electrode near the nozzle applies an alternating Coulomb force to the jet surface, generating a disturbance which grows until a drop breaks off downstream. This interaction is modelled quite well by a linear, long wave model of the jet together with a cylindrical electric field. The breakup length, measured on a 33 micrometer jet, agrees quite well with that predicted by the theory, and increases with the square of the applied voltage, as expected. In addition, the frequency response is very smooth, with pronounced nulls occurring only at frequencies related to the time which the jet spends inside the exciter.

Knee Osteoarthritis Treatment with the KineSpring Knee Implant System: A Report of Two Cases

PubMed Central

Hayes, David A.; Miller, Larry E.; Block, Jon E.

2012-01-01

Osteoarthritis (OA) is a leading cause of disability in middle-aged and older adults with the prevalence expected to increase by 40% by 2025. This dramatic projected increase in OA reflects, in large part, the alarming obesity epidemic. Indeed, it is now well understood that abnormal loading across the knee joint due to malalignment and/or excessive weight gain is responsible for accelerating OA progression. Consequently, there is a therapeutic need for alternative knee OA treatments that directly address joint overload to fill the gap between ineffective conservative care and invasive joint-modifying surgical procedures. We describe two cases that presented with bilateral knee OA resistant to conservative treatments, each with one knee previously and unsuccessfully treated with high tibial osteotomy to improve alignment and the contralateral knee successfully treated with a joint-preserving, load-absorbing implant (KineSpring Knee Implant System). PMID:23304590

Noninvasive determination of optical lever sensitivity in atomic force microscopy

NASA Astrophysics Data System (ADS)

Higgins, M. J.; Proksch, R.; Sader, J. E.; Polcik, M.; Mc Endoo, S.; Cleveland, J. P.; Jarvis, S. P.

2006-01-01

Atomic force microscopes typically require knowledge of the cantilever spring constant and optical lever sensitivity in order to accurately determine the force from the cantilever deflection. In this study, we investigate a technique to calibrate the optical lever sensitivity of rectangular cantilevers that does not require contact to be made with a surface. This noncontact approach utilizes the method of Sader et al. [Rev. Sci. Instrum. 70, 3967 (1999)] to calibrate the spring constant of the cantilever in combination with the equipartition theorem [J. L. Hutter and J. Bechhoefer, Rev. Sci. Instrum. 64, 1868 (1993)] to determine the optical lever sensitivity. A comparison is presented between sensitivity values obtained from conventional static mode force curves and those derived using this noncontact approach for a range of different cantilevers in air and liquid. These measurements indicate that the method offers a quick, alternative approach for the calibration of the optical lever sensitivity.

Technical features of curriculum-based measures for beginning writers.

PubMed

McMaster, Kristen L; Xiaoqing Du; Pétursdóttir, Anna-Lind

2009-01-01

The purpose of the two studies reported in this article was to examine technical features of curriculum-based measures for beginning writers. In Study 1, 50 first graders responded to word copying, sentence copying, and story prompts. In Study 2, 50 additional first graders responded to letter, picture-word, picture-theme, and photo prompts. In both studies, 3- to 5-minute prompts were administered in winter and spring and scored using a variety of quantitative procedures. Students were also administered the Test of Written Language-Third Edition , and teacher ratings and scores on a district rubric for writing were collected. Test-retest (Study 1 only) and alternate-form reliability, criterion validity, and winter-to-spring growth were examined for each measure. Sentence-copying, story, picture-word, and photo prompts emerged as promising beginning-writing measures. Findings have implications for monitoring student progress within a seamless and flexible system across ages and skill levels.

Ozone vertical profile changes over South Pole

NASA Technical Reports Server (NTRS)

Oltmans, S. J.; Hofmann, D. J.; Komhyr, W. D.; Lathrop, J. A.

1994-01-01

Important changes in the ozone vertical profile over South Pole, Antarctica have occurred both during the recent period of measurements, 1986-1991, and since an earlier set of soundings was carried out from 1967-1971. From the onset of the 'ozone hole' over Antarctica in the early 1980s, there has been a tendency for years with lower spring ozone amounts to alternate with years with somewhat higher (although still depleted) ozone amounts. Beginning in 1989 there have been three consecutive years of strong depletion although the timing of the breakdown of the vortex has varied from year to year. Comparison of the vertical profiles between the two periods of study reveals the dramatic decreases in the ozone amounts in the stratosphere between 15-21 km during the spring. In addition, it appears that summer values are also now much lower in this altitude region.

Littoral foraging by red phalaropes during spring in the northern Bering Sea

USGS Publications Warehouse

Haney, J. Christopher; Stone, Amy E.

1988-01-01

Phalaropes demonstrate considerable plasticity in their choice of foraging habitats. The Red Phalarope (Phalaropus fulicaria) alternates use of pelagic environments in winter and migration (Taning 1933, Stanford 1953, Briggs et al 1984) with wet tundra habitats during the breeding season (Kistchinski 1975, Mayfield 1979, Ridley 1980). Foods available and taken in littoral zones of the Arctic Ocean in fall have been identified (Conners and Risebrough 1978, Johnson and Richardson 1980), but otherwise little attention has been devoted to the transition between the marine and terrestrial periods of the Red Phalarope’s life history. We report phalarope use of littoral areas during spring in the northern Bering Sea and Kongkok Bay, St. Lawrence Island, Alaska. In addition, we describe phalarope foraging tactics and foods available in the sur zone, emphasizing this form of littoral foraging as an opportunistic and facultative feeding strategy.

Seismomagnetic observation during the 8 July 1986 magnitude 5.9 North Palm Springs earthquake

USGS Publications Warehouse

Johnston, M.J.S.; Mueller, R.J.

1987-01-01

A differentially connected array of 24 proton magnetometers has operated along the San Andreas fault since 1976. Seismomagnetic offsets of 1.2 and 0.3 nanotesla were observed at epicentral distances of 3 and 9 kilometers, respectively, after the 8 July 1986 magnitude 5.9 North Palm Springs earthquake. These seismomagnetic observations are the first obtained of this elusive but long-anticipated effect. The data are consistent with a seismomagnetic model of the earthquake for which right-lateral rupture of 20 centimeters is assumed on a 16-kilometer segment of the Banning fault between the depths of 3 and 10 kilometers in a region with average magnetization of 1 ampere per meter. Alternative explanations in terms of electrokinetic effects and earthquake-generated electrostatic charge redistribution seem unlikely because the changes are permanent and complete within a 20-minute period.

Evaluation of three gears for sampling spawning populations of rainbow trout in a large Alaskan river

USGS Publications Warehouse

Schwanke, C.J.; Hubert, W.A.

2004-01-01

Alternatives to electrofishing are needed for sampling sexually mature rainbow trout Oncorhynchus mykiss during the spawning season in large Alaskan rivers. We compared hook and line, beach seining, and actively fished gill nets as sampling tools. Beach seining and active gill netting yielded similar catch rates, length frequencies, and sex ratios of sexually mature fish. Hook-and-line sampling was less effective, with a lower catch rate and selectivity for immature fish and sexually mature females. We conclude that both beach seining and active gill netting can serve as alternatives to electrofishing for sampling sexually mature rainbow trout stocks during the spawning season in large rivers with stable spring flows and spawning areas with few snags.

Trends in complementary/alternative medicine use by breast cancer survivors: Comparing survey data from 1998 and 2005

PubMed Central

Boon, Heather S; Olatunde, Folashade; Zick, Suzanna M

2007-01-01

Background Use of complementary and alternative medicine (CAM) by women with breast cancer is often said to be increasing, yet few data exist to confirm this commonly held belief. The purpose of this paper is to compare overall patterns of CAM use, as well as use of specific products and therapies at two different points in time (1998 vs 2005) by women diagnosed with breast cancer. Methods Surveys were mailed to women randomly selected from the Ontario Cancer Registry (Canada) in the spring of 1998 (n = 557) and again in the spring of 2005(n = 877). Results The response rates were 76.3% in 1998 and 63% in 2005. In 1998, 66.7% of women reported using either a CAM product/therapy or seeing a CAM therapist at some time in their lives as compared with 81.9% in 2005 (p = 0.0002). Increases were seen in both use of CAM products/therapies (62% in 1998 vs. 70.6% in 2005) and visits to CAM practitioners (39.4% of respondents in 1998 vs 57.4% of respondents in 2005). Women in 2005 reported that 41% used CAM for treating their breast cancer. The most commonly used products and practitioners for treating breast cancer as reported in 2005 were green tea, vitamin E, flaxseed, vitamin C, massage therapists and dietitians/nutritionists. Conclusion CAM use (both self-medication with products and visits to CAM practitioners) increased significantly from 1998 to 2005. Now that more than 80% of all women with breast cancer report using CAM (41% in a specific attempt to management their breast cancer), CAM use can no longer be regarded as an "alternative" or unusual approach to managing breast cancer. PMID:17397542

Multidisciplinary optimization for engineering systems - Achievements and potential

NASA Technical Reports Server (NTRS)

Sobieszczanski-Sobieski, Jaroslaw

1989-01-01

The currently common sequential design process for engineering systems is likely to lead to suboptimal designs. Recently developed decomposition methods offer an alternative for coming closer to optimum by breaking the large task of system optimization into smaller, concurrently executed and, yet, coupled tasks, identified with engineering disciplines or subsystems. The hierarchic and non-hierarchic decompositions are discussed and illustrated by examples. An organization of a design process centered on the non-hierarchic decomposition is proposed.

Multidisciplinary optimization for engineering systems: Achievements and potential

NASA Technical Reports Server (NTRS)

Sobieszczanski-Sobieski, Jaroslaw

1989-01-01

The currently common sequential design process for engineering systems is likely to lead to suboptimal designs. Recently developed decomposition methods offer an alternative for coming closer to optimum by breaking the large task of system optimization into smaller, concurrently executed and, yet, coupled tasks, identified with engineering disciplines or subsystems. The hierarchic and non-hierarchic decompositions are discussed and illustrated by examples. An organization of a design process centered on the non-hierarchic decomposition is proposed.

Non-linear dynamics and alternating 'flip' solutions in ferrofluidic Taylor-Couette flow

NASA Astrophysics Data System (ADS)

Altmeyer, Sebastian

2018-04-01

This study treats with the influence of a symmetry-breaking transversal magnetic field on the nonlinear dynamics of ferrofluidic Taylor-Couette flow - flow confined between two concentric independently rotating cylinders. We detected alternating 'flip' solutions which are flow states featuring typical characteristics of slow-fast-dynamics in dynamical systems. The flip corresponds to a temporal change in the axial wavenumber and we find them to appear either as pure 2-fold axisymmetric (due to the symmetry-breaking nature of the applied transversal magnetic field) or involving non-axisymmetric, helical modes in its interim solution. The latter ones show features of typical ribbon solutions. In any case the flip solutions have a preferential first axial wavenumber which corresponds to the more stable state (slow dynamics) and second axial wavenumber, corresponding to the short appearing more unstable state (fast dynamics). However, in both cases the flip time grows exponential with increasing the magnetic field strength before the flip solutions, living on 2-tori invariant manifolds, cease to exist, with lifetime going to infinity. Further we show that ferrofluidic flow turbulence differ from the classical, ordinary (usually at high Reynolds number) turbulence. The applied magnetic field hinders the free motion of ferrofluid partials and therefore smoothen typical turbulent quantities and features so that speaking of mildly chaotic dynamics seems to be a more appropriate expression for the observed motion.

DNA Damage Response Factors from Diverse Pathways, Including DNA Crosslink Repair, Mediate Alternative End Joining

PubMed Central

Howard, Sean M.; Yanez, Diana A.; Stark, Jeremy M.

2015-01-01

Alternative end joining (Alt-EJ) chromosomal break repair involves bypassing classical non-homologous end joining (c-NHEJ), and such repair causes mutations often with microhomology at the repair junction. Since the mediators of Alt-EJ are not well understood, we have sought to identify DNA damage response (DDR) factors important for this repair event. Using chromosomal break reporter assays, we surveyed an RNAi library targeting known DDR factors for siRNAs that cause a specific decrease in Alt-EJ, relative to an EJ event that is a composite of Alt-EJ and c-NHEJ (Distal-EJ between two tandem breaks). From this analysis, we identified several DDR factors that are specifically important for Alt-EJ relative to Distal-EJ. While these factors are from diverse pathways, we also found that most of them also promote homologous recombination (HR), including factors important for DNA crosslink repair, such as the Fanconi Anemia factor, FANCA. Since bypass of c-NHEJ is likely important for both Alt-EJ and HR, we disrupted the c-NHEJ factor Ku70 in Fanca-deficient mouse cells and found that Ku70 loss significantly diminishes the influence of Fanca on Alt-EJ. In contrast, an inhibitor of poly ADP-ribose polymerase (PARP) causes a decrease in Alt-EJ that is enhanced by Ku70 loss. Additionally, the helicase/nuclease DNA2 appears to have distinct effects from FANCA and PARP on both Alt-EJ, as well as end resection. Finally, we found that the proteasome inhibitor Bortezomib, a cancer therapeutic that has been shown to disrupt FANC signaling, causes a significant reduction in both Alt-EJ and HR, relative to Distal-EJ, as well as a substantial loss of end resection. We suggest that several distinct DDR functions are important for Alt-EJ, which include promoting bypass of c-NHEJ and end resection. PMID:25629353

Design, Analysis and Implementation of an Experimental System to Harvest Energy From Atmospheric Temperature Variations Using Ethyl Chloride Filled Bellows

NASA Astrophysics Data System (ADS)

Ali, Gibran

The increase in global warming and the dwindling supplies of fossil fuels have shifted the focus from traditional to alternate sources of energy. This has resulted in a concerted effort towards finding new energy sources as well as better understanding traditional renewable energy sources such as wind and solar power. In addition to the shift in focus towards alternate energy, the last two decades have offered a dramatic rise in the use of digital technologies such as wireless sensor networks that require small but isolated power supplies. Energy harvesting, a method to gather energy from ambient sources including sunlight, vibrations, heat, etc., has provided some success in powering these systems. One of the unexplored areas of energy harvesting is the use of atmospheric temperature variations to obtain usable energy. This thesis investigates an innovative mechanism to extract energy from atmospheric variations using ethyl chloride filled mechanical bellows. The energy harvesting process was divided into two parts. The first part consisted of extracting energy from the temperature variations and converting it into the potential energy stored in a linear coil spring. This was achieved by designing and fabricating an apparatus that consisted of an ethyl chloride filled bellows working against a mechanical spring in a closed and controlled environment. The bellows expanded/contracted depending upon the ambient temperature and the energy harvested was calculated as a function of the bellows' length. The experiments showed that 6 J of potential energy may be harvested for a 23°C change in temperature. The numerical results closely correlated to the experimental data with an error magnitude of 1%. In regions with high diurnal temperature variation, such an apparatus may yield approximately 250 microwatts depending on the diurnal temperature range. The second part of the energy harvesting process consisted of transforming linear expansion of the bellows into electric power. A system was designed and simulated using Mathworks Simulink and SimDriveline packages that converted the linear oscillations of the bellows into electric power. This was achieved in two steps; a gear train was designed that would convert the linear displacement of the bellows into potential energy stored in a spiral spring. The spiral spring would then periodically engage to a small generator producing electric power. The electrical power generated was found to depend solely on the potential energy stored in the spring. It was discovered that for a sinusoidal force with constant amplitude and frequency, the potential energy stored in the spring depended on the duration of force input and the parameters of the drivetrain such as the spring stiffness, the gear ratios, and the pinion radii. After simulating the system for different parameters, an optimal set of values was presented to maximize the electrical energy output for a given duration of time. For constant amplitude (120 N) sinusoidal force input with a time period of T seconds, the system stored 37 J, 65 J, and 90 J after a time of 3T, 5T, and 7T, respectively. The electric power output was 7.14 microwatts for a conversion efficiency of 5%. The next step is building a physical geartrain generator assembly based on the design presented in the thesis. The physical system will first be verified by simulating the force input using a pneumatic cylinder. The two parts of the research experiment can then be integrated into one system that would generate electric power directly from temporal temperature and pressure variations.

Vibration Interaction in a Multiple Flywheel System

DTIC Science & Technology

2011-03-01

IP/IT ) t time x x−axis y y−axis z z−axis κ rotational spring stiffness ρ radial distance between flywheel center of mass and shaft center θ axial...they may be a viable alternative for the satellite designer . One additional benefit of flywheel-based energy storage is its inherent ability to control...rotating wheels it can change the satellite’s attitude by exchanging momentum between flywheels and 2 the spacecraft. Thus an IPACS, if well designed

Genesis lunar outpost: An evolutionary lunar habitat

NASA Technical Reports Server (NTRS)

Moore, Gary T. (Compiler); Baschiera, Dino; Fieber, Joe; Moths, Janis

1990-01-01

Students at the University of Wisconsin-Milwaukee Department of Agriculture undertook a series of studies of lunar habitats during the 1989 to 1990 academic year. Undergraduate students from architecture and mechanical and structural engineering with backgrounds in interior design, biology and construction technology were involved in a seminar in the fall semester followed by a design studio in the spring. The studies resulted in three design alternatives for lunar habitation and an integrated design for an early stage lunar outpost.

Environmental and economic analysis of switchgrass production for water quality improvement in northeast Kansas.

PubMed

Nelson, Richard G; Ascough, James C; Langemeier, Michael R

2006-06-01

The primary objectives of this research were to determine SWAT model predicted reductions in four water quality indicators (sediment yield, surface runoff, nitrate nitrogen (NO(3)-N) in surface runoff, and edge-of-field erosion) associated with producing switchgrass (Panicum virgatum) on cropland in the Delaware basin in northeast Kansas, and evaluate switchgrass break-even prices. The magnitude of potential switchgrass water quality payments based on using switchgrass as an alternative energy source was also estimated. SWAT model simulations showed that between 527,000 and 1.27 million metric tons (Mg) of switchgrass could be produced annually across the basin depending upon nitrogen (N) fertilizer application levels (0-224 kg N ha(-1)). The predicted reductions in sediment yield, surface runoff, NO(3)-N in surface runoff, and edge-of-field erosion as a result of switchgrass plantings were 99, 55, 34, and 98%, respectively. The average annual cost per hectare for switchgrass ranged from about 190 US dollars with no N applied to around 345 US dollars at 224 kg N ha(-1) applied. Edge-of-field break-even price per Mg ranged from around 41 US dollars with no N applied to slightly less than 25 US dollars at 224 kg N ha(-1) applied. A majority of the switchgrass produced had an edge-of-field break-even price of 30 Mg(-1) US dollars or less. Savings of at least 50% in each of the four water quality indicators could be attained for an edge-of-field break-even price of 22-27.49 US dollars Mg(-1).

Characterizing Droplet Formation from Non-Linear Slosh in a Propellant Tank

NASA Technical Reports Server (NTRS)

Brodnick, Jacob; Yang, Hong; West, Jeffrey

2015-01-01

The Fluid Dynamics Branch (ER42) at the Marshall Space Flight Center (MSFC) was tasked with characterizing the formation and evolution of liquid droplets resulting from nonlinear propellant slosh in a storage tank. Lateral excitation of propellant tanks can produce high amplitude nonlinear slosh waves through large amplitude excitations and or excitation frequencies near a resonance frequency of the tank. The high amplitude slosh waves become breaking waves upon attaining a certain amplitude or encountering a contracting geometry such as the upper dome section of a spherical tank. Inherent perturbations in the thinning regions of breaking waves result in alternating regions of high and low pressure within the fluid. Droplets form once the force from the local pressure differential becomes larger than the force maintaining the fluid interface shape due to surface tension. Droplets released from breaking waves in a pressurized tank may lead to ullage collapse given the appropriate conditions due to the increased liquid surface area and thus heat transfer between the fluids. The goal of this project is to create an engineering model that describes droplet formation as a function of propellant slosh for use in the evaluation of ullage collapse during a sloshing event. The Volume of Fluid (VOF) model in the production level Computational Fluid Dynamics (CFD) code Loci-Stream was used to predict droplet formation from breaking waves with realistic surface tension characteristics. Various excitation frequencies and amplitudes were investigated at multiple fill levels for a single storage tank to create the engineering model of droplet formation from lateral propellant slosh.

Ergonomic principles and tools for best interdisciplinary psycho-physical stress prevention.

PubMed

Dal Cason, Dott Luigi

2012-01-01

The psycho-physical stress is a risk to all intents and purposes,finally acknowledged, it requires increasing attention. Measures forits protection are reflected in the appropriate application of organizational policies on a human scale, or in respect of the"macro-ergonomics". This work consists on several inter-disciplinary tools available to the proper prevention, outbreaks of work-related stress.During work, adequate rests are important to prevent work related physical and mental fatigue. The strategies for maintaining a healthy balance between work rate and work breaks, may differ depending on the individual, subjective habits and peculiarities related to the work environment. Resting does not necessarily mean "going to break". The break-time is important as the work-time. While the latter is regulated, the first is not always clearly defined, though necessary. Knowing the employment contract is the first step towards the implementation of their rights relating to periods of suspension from the activity of work is also essential for high performance working. Breathing exercises, massage therapy, biofeedback, role-playing are some of the tools used during work breaks to prevent mental and physical fatigue. At the end music has a rhythm by alternating strong and weak accents. If the musical notes represent the "vertical" trend of music (melody), figures and pauses, inserted into the rhythmic structure of the measure, regulate the duration of sounds over time and determine the "horizontal" trend of a song. Transferring this concept on work, is meant to understand, using a metaphor, the importance of respect of changes in both vertical and horizontal trends inside a cycle.

Mutational signatures of non-homologous and polymerase theta-mediated end-joining in embryonic stem cells.

PubMed

Schimmel, Joost; Kool, Hanneke; van Schendel, Robin; Tijsterman, Marcel

2017-12-15

Cells employ potentially mutagenic DNA repair mechanisms to avoid the detrimental effects of chromosome breaks on cell survival. While classical non-homologous end-joining (cNHEJ) is largely error-free, alternative end-joining pathways have been described that are intrinsically mutagenic. Which end-joining mechanisms operate in germ and embryonic cells and thus contribute to heritable mutations found in congenital diseases is, however, still largely elusive. Here, we determined the genetic requirements for the repair of CRISPR/Cas9-induced chromosomal breaks of different configurations, and establish the mutational consequences. We find that cNHEJ and polymerase theta-mediated end-joining (TMEJ) act both parallel and redundant in mouse embryonic stem cells and account for virtually all end-joining activity. Surprisingly, mutagenic repair by polymerase theta (Pol θ, encoded by the Polq gene) is most prevalent for blunt double-strand breaks (DSBs), while cNHEJ dictates mutagenic repair of DSBs with protruding ends, in which the cNHEJ polymerases lambda and mu play minor roles. We conclude that cNHEJ-dependent repair of DSBs with protruding ends can explain de novo formation of tandem duplications in mammalian genomes. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

A rationale for long-lived quarks and leptons at the LHC: low energy flavour theory

NASA Astrophysics Data System (ADS)

Éboli, O. J. P.; Savoy, C. A.; Funchal, R. Zukanovich

2012-02-01

In the framework of gauged flavour symmetries, new fermions in parity symmetric representations of the standard model are generically needed for the compensation of mixed anomalies. The key point is that their masses are also protected by flavour symmetries and some of them are expected to lie way below the flavour symmetry breaking scale(s), which has to occur many orders of magnitude above the electroweak scale to be compatible with the available data from flavour changing neutral currents and CP violation experiments. We argue that, actually, some of these fermions would plausibly get masses within the LHC range. If they are taken to be heavy quarks and leptons, in (bi)-fundamental representations of the standard model symmetries, their mixings with the light ones are strongly constrained to be very small by electroweak precision data. The alternative chosen here is to exactly forbid such mixings by breaking of flavour symmetries into an exact discrete symmetry, the so-called proton-hexality, primarily suggested to avoid proton decay. As a consequence of the large value needed for the flavour breaking scale, those heavy particles are long-lived and rather appropriate for the current and future searches at the LHC for quasi-stable hadrons and leptons. In fact, the LHC experiments have already started to look for them.

Novel approach for dam break flow modeling using computational intelligence

NASA Astrophysics Data System (ADS)

Seyedashraf, Omid; Mehrabi, Mohammad; Akhtari, Ali Akbar

2018-04-01

A new methodology based on the computational intelligence (CI) system is proposed and tested for modeling the classic 1D dam-break flow problem. The reason to seek for a new solution lies in the shortcomings of the existing analytical and numerical models. This includes the difficulty of using the exact solutions and the unwanted fluctuations, which arise in the numerical results. In this research, the application of the radial-basis-function (RBF) and multi-layer-perceptron (MLP) systems is detailed for the solution of twenty-nine dam-break scenarios. The models are developed using seven variables, i.e. the length of the channel, the depths of the up-and downstream sections, time, and distance as the inputs. Moreover, the depths and velocities of each computational node in the flow domain are considered as the model outputs. The models are validated against the analytical, and Lax-Wendroff and MacCormack FDM schemes. The findings indicate that the employed CI models are able to replicate the overall shape of the shock- and rarefaction-waves. Furthermore, the MLP system outperforms RBF and the tested numerical schemes. A new monolithic equation is proposed based on the best fitting model, which can be used as an efficient alternative to the existing piecewise analytic equations.

Internal tidal mixing as a control on continental margin ecosystems

NASA Astrophysics Data System (ADS)

Sharples, Jonathan; Moore, C. Mark; Hickman, Anna E.; Holligan, Patrick M.; Tweddle, Jacqueline F.; Palmer, Matthew R.; Simpson, John H.

2009-12-01

We show that a breaking internal tide at a shelf edge is a fundamental control on the structural and functional properties of ecosystems. Contrasts in vertical mixing of nitrate between the shelf and the open ocean correspond with horizontal and vertical changes in phytoplankton communities, with largest cells found in surface waters at the shelf edge. Intense fishing activity is commonly seen at continental shelf edges, targeting spawning fish stocks. We suggest that the internal tide, a globally ubiquitous physical process at steep shelf edge bathymetry, supports shelf edge fisheries by providing large-celled phytoplankton for first-feeding fish larvae. The repeatability of the internal tide removes fish from the need to time spawning with a spring bloom. Also, with large phytoplankton cells dominating particulate organic carbon export, the internal tides could be an important influence on spatial and temporal variability in patterns of global carbon sequestration in deep water and sediments.

An ecologic study of peat landforms in Canada and Alaska

NASA Technical Reports Server (NTRS)

Glaser, P. H.

1986-01-01

The role of groundwater and surface runoff in controlling the water chemistry and development of peat landforms in northern Minnesota are described. The LANDSAT imagery taken duing spring break-up are particularly valuable in identifying potential zones of groundwater discharge. The vascular floras of raised bogs in eastern North Americas demonstrating the remarkabe uniformity of the ombrotrophic flora over broad geographic regions are described. The evolution of peat landforms in the major boreal peatlands of eastern America is examined. The LANDSAT imagery is used to determine the area of patterned to featureless peatlands, the area of ombrotrophic bog relative to minerotrophic fen, and the relative size and degree of streamlining of island landforms entirely composed of peat. Such measurements can be used to assess the role of climate, time, and hydrology in controlling the formation of peatland patterns across broad geographic regions.