A Critical Appraisal of State Level Science Exhibition

ERIC Educational Resources Information Center

Nath, Baiju K.

2007-01-01

Science exhibitions are really great opportunities to students as well as teachers to disseminate knowledge that they have, and to experience a variety of new inventions and innovations that also need wide dissemination. The great significance of exhibition is that it fosters acquisition of different process skills leading to the development of…

Poster exhibitions at conferences: are we doing it properly?

PubMed

Beamish, Andrew J; Ansell, James; Foster, Jessica J; Foster, Kathryn A; Egan, Richard J

2015-01-01

Literature exploring the educational value and quality of conference poster presentation is scarce. The aim of this study was to identify and describe the variation in poster exhibitions across a spectrum of conferences attended by trainees. Prospective observational assessment of conference posters was carried out across 7 variables at 4 conferences attended by surgical trainees in 2012. Posters were compared by individual variables and according to overall poster score combining all 7 variables examined. The number of authors listed was also compared. Random samples of consecutively numbered posters were examined at the exhibitions of 4 conferences, which included a UK national medical education conference (Association for the Study of Medical Education), a UK international surgical conference (Association of Surgeons of Great Britain and Ireland), a European oncology conference (European Society of Surgical Oncology), and a North American joint medical and surgical conference (Digestive Diseases Week). Significant variation existed between conferences in posters and their presentation. The proportion of presenters failing to display their posters ranged from 3% to 26% (p < 0.0001). Adherence to size guidelines varied from 89% to 100% (p = 0.002). The inclusion of references ranged from 19% to 82% (p < 0.0001). The presence of a presenting author during the allocated session varied widely from 21% to 86% (p < 0.0001). No significant variation was observed in the proportion of posters that were formatted using aims, methods, results, and conclusion sections (81%-93%; p = 0.513) or in the proportion of posters that were identified as difficult to read (24%-28%; p = 0.919). Association for the Study of Medical Education outperformed each of the other exhibitions overall (p < 0.0001). Posters with greater than the median of 4 authors performed significantly better across all areas (p < 0.0001-0.042) except presenter attendance (p = 0.480). Poster exhibitions varied widely, with room for improvement at all 4 conferences. Lessons can be learned by all conferences from each other to improve presenter engagement with and the educational value of poster exhibitions. Copyright © 2014 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Characterization and comparison of phytoplankton in selected lakes of five Great Lakes area national parks

USGS Publications Warehouse

Nevers, Meredith Becker; Whitman, Richard L.

2004-01-01

Phytoplankton species have been widely used as indicators of lake conditions, and they may be useful for detecting changes in overall lake condition. In an attempt to inventory and monitor its natural resources, the National Park Service wants to establish a monitoring program for aquatic resources in the Great Lakes Cluster National Parks. This study sought to establish baseline information on the phytoplankton and water chemistry of selected lakes in five national parks in a preliminary effort toward establishing a long-term monitoring program. Phytoplankton and water chemistry samples were collected from ten lakes in five national parks over a two-year period. A total of 176 taxa were identified during the study. Northern lakes generally had higher Shannon-Wiener diversity and clustered together in similarity. Lakes exhibited a south to north gradient of many water chemistry variables, with northern lakes having lower hardness, sulfate, turbidity, and temperature and higher dissolved oxygen. Chloride and sulfate concentrations were the variables that best explained variation among phytoplankton in the ten lakes. A monitoring plan will have to incorporate the differences among lakes, but by coordinating the effort, comparisons within and among parks and other regions will prove useful for determining environmental change.

The integration of geophysical and enhanced Moderate Resolution Imaging Spectroradiometer Normalized Difference Vegetation Index data into a rule-based, piecewise regression-tree model to estimate cheatgrass beginning of spring growth

USGS Publications Warehouse

Boyte, Stephen P.; Wylie, Bruce K.; Major, Donald J.; Brown, Jesslyn F.

2015-01-01

Cheatgrass exhibits spatial and temporal phenological variability across the Great Basin as described by ecological models formed using remote sensing and other spatial data-sets. We developed a rule-based, piecewise regression-tree model trained on 99 points that used three data-sets – latitude, elevation, and start of season time based on remote sensing input data – to estimate cheatgrass beginning of spring growth (BOSG) in the northern Great Basin. The model was then applied to map the location and timing of cheatgrass spring growth for the entire area. The model was strong (R2 = 0.85) and predicted an average cheatgrass BOSG across the study area of 29 March–4 April. Of early cheatgrass BOSG areas, 65% occurred at elevations below 1452 m. The highest proportion of cheatgrass BOSG occurred between mid-April and late May. Predicted cheatgrass BOSG in this study matched well with previous Great Basin cheatgrass green-up studies.

The Great Lakes' regional climate regimes

NASA Astrophysics Data System (ADS)

Sugiyama, Noriyuki

For the last couple of decades, the Great Lakes have undergone rapid surface warming. In particular, the magnitude of the summer surface-warming trends of the Great Lakes have been much greater than those of surrounding land (Austin and Colman, 2007). Among the Great Lakes, the deepest Lake Superior exhibited the strongest warming trend in its annual, as well as summer surface water temperature. We find that many aspects of this behavior can be explained in terms of the tendency of deep lakes to exhibit multiple regimes characterized, under the same seasonally varying forcing, by the warmer and colder seasonal cycles exhibiting different amounts of wintertime lake-ice cover and corresponding changes in the summertime lake-surface temperatures. In this thesis, we address the problem of the Great Lakes' warming using one-dimensional lake modeling to interpret diverse observations of the recent lake behavior. (Abstract shortened by ProQuest.).

Temporal variability of exchange between groundwater and surface water based on high-frequency direct measurements of seepage at the sediment-water interface

USGS Publications Warehouse

Rosenberry, Donald O.; Sheibley, Rich W.; Cox, Stephen E.; Simonds, Frederic W.; Naftz, David L.

2013-01-01

Seepage at the sediment-water interface in several lakes, a large river, and an estuary exhibits substantial temporal variability when measured with temporal resolution of 1 min or less. Already substantial seepage rates changed by 7% and 16% in response to relatively small rain events at two lakes in the northeastern USA, but did not change in response to two larger rain events at a lake in Minnesota. However, seepage at that same Minnesota lake changed by 10% each day in response to withdrawals from evapotranspiration. Seepage increased by more than an order of magnitude when a seiche occurred in the Great Salt Lake, Utah. Near the head of a fjord in Puget Sound, Washington, seepage in the intertidal zone varied greatly from −115 to +217 cm d−1 in response to advancing and retreating tides when the time-averaged seepage was upward at +43 cm d−1. At all locations, seepage variability increased by one to several orders of magnitude in response to wind and associated waves. Net seepage remained unchanged by wind unless wind also induced a lake seiche. These examples from sites distributed across a broad geographic region indicate that temporal variability in seepage in response to common hydrological events is much larger than previously realized. At most locations, seepage responded within minutes to changes in surface-water stage and within minutes to hours to groundwater recharge associated with rainfall. Likely implications of this dynamism include effects on water residence time, geochemical transformations, and ecological conditions at and near the sediment-water interface.

The Sun: Source of the Earth's Energy

NASA Technical Reports Server (NTRS)

Thompson, Barbara J.; Fisher, Richard R. (Technical Monitor)

2001-01-01

The Sun is the primary source of the Earth's energy. However, due to the complexity in the way the energy affects Earth, the various solar sources of the energy, and the variation exhibited by the Sun it is difficult to understand and predict the Earth's response to solar drivers. In addition to visible light the radiant energy of the Sun can exhibit variation in nearly all wavelengths, which can vary over nearly all timescales. Depending on the wavelength of the incident radiation the light can deposit energy in a wide variety or locations and drive processes from below Earth's surface to interplanetary space. Other sources of energy impacting Earth include energetic particles, magnetic fields, and mass and flow variations in the solar wind. Many of these variable energetic processes cannot be coupled and recent results continue to demonstrate that the complex dynamics of the Sun can have a great range of measurable impacts on Earth.

Entanglement Entropy across the Superfluid-Insulator Transition: A Signature of Bosonic Criticality.

PubMed

Frérot, Irénée; Roscilde, Tommaso

2016-05-13

We study the entanglement entropy and entanglement spectrum of the paradigmatic Bose-Hubbard model, describing strongly correlated bosons on a lattice. The use of a controlled approximation-the slave-boson approach-allows us to study entanglement in all regimes of the model (and, most importantly, across its superfluid-Mott-insulator transition) at a minimal cost. We find that the area-law scaling of entanglement-verified in all the phases-exhibits a sharp singularity at the transition. The singularity is greatly enhanced when the transition is crossed at fixed, integer filling, due to a richer entanglement spectrum containing an additional gapless mode, which descends from the amplitude (Higgs) mode of the global excitation spectrum-while this mode remains gapped at the generic (commensurate-incommensurate) transition with variable filling. Hence, the entanglement properties contain a unique signature of the two different forms of bosonic criticality exhibited by the Bose-Hubbard model.

Estimation of intra-operator variability in perfusion parameter measurements using DCE-US

PubMed Central

Gauthier, Marianne; Leguerney, Ingrid; Thalmensi, Jessie; Chebil, Mohamed; Parisot, Sarah; Peronneau, Pierre; Roche, Alain; Lassau, Nathalie

2011-01-01

AIM: To investigate intra-operator variability of semi-quantitative perfusion parameters using dynamic contrast-enhanced ultrasonography (DCE-US), following bolus injections of SonoVue®. METHODS: The in vitro experiments were conducted using three in-house sets up based on pumping a fluid through a phantom placed in a water tank. In the in vivo experiments, B16F10 melanoma cells were xenografted to five nude mice. Both in vitro and in vivo, images were acquired following bolus injections of the ultrasound contrast agent SonoVue® (Bracco, Milan, Italy) and using a Toshiba Aplio® ultrasound scanner connected to a 2.9-5.8 MHz linear transducer (PZT, PLT 604AT probe) (Toshiba, Japan) allowing harmonic imaging (“Vascular Recognition Imaging”) involving linear raw data. A mathematical model based on the dye-dilution theory was developed by the Gustave Roussy Institute, Villejuif, France and used to evaluate seven perfusion parameters from time-intensity curves. Intra-operator variability analyses were based on determining perfusion parameter coefficients of variation (CV). RESULTS: In vitro, different volumes of SonoVue® were tested with the three phantoms: intra-operator variability was found to range from 2.33% to 23.72%. In vivo, experiments were performed on tumor tissues and perfusion parameters exhibited values ranging from 1.48% to 29.97%. In addition, the area under the curve (AUC) and the area under the wash-out (AUWO) were two of the parameters of great interest since throughout in vitro and in vivo experiments their variability was lower than 15.79%. CONCLUSION: AUC and AUWO appear to be the most reliable parameters for assessing tumor perfusion using DCE-US as they exhibited the lowest CV values. PMID:21512654

Estimation of intra-operator variability in perfusion parameter measurements using DCE-US.

PubMed

Gauthier, Marianne; Leguerney, Ingrid; Thalmensi, Jessie; Chebil, Mohamed; Parisot, Sarah; Peronneau, Pierre; Roche, Alain; Lassau, Nathalie

2011-03-28

To investigate intra-operator variability of semi-quantitative perfusion parameters using dynamic contrast-enhanced ultrasonography (DCE-US), following bolus injections of SonoVue(®). The in vitro experiments were conducted using three in-house sets up based on pumping a fluid through a phantom placed in a water tank. In the in vivo experiments, B16F10 melanoma cells were xenografted to five nude mice. Both in vitro and in vivo, images were acquired following bolus injections of the ultrasound contrast agent SonoVue(®) (Bracco, Milan, Italy) and using a Toshiba Aplio(®) ultrasound scanner connected to a 2.9-5.8 MHz linear transducer (PZT, PLT 604AT probe) (Toshiba, Japan) allowing harmonic imaging ("Vascular Recognition Imaging") involving linear raw data. A mathematical model based on the dye-dilution theory was developed by the Gustave Roussy Institute, Villejuif, France and used to evaluate seven perfusion parameters from time-intensity curves. Intra-operator variability analyses were based on determining perfusion parameter coefficients of variation (CV). In vitro, different volumes of SonoVue(®) were tested with the three phantoms: intra-operator variability was found to range from 2.33% to 23.72%. In vivo, experiments were performed on tumor tissues and perfusion parameters exhibited values ranging from 1.48% to 29.97%. In addition, the area under the curve (AUC) and the area under the wash-out (AUWO) were two of the parameters of great interest since throughout in vitro and in vivo experiments their variability was lower than 15.79%. AUC and AUWO appear to be the most reliable parameters for assessing tumor perfusion using DCE-US as they exhibited the lowest CV values.

Sensitivity of Great Lakes Ice Cover to Air Temperature

NASA Astrophysics Data System (ADS)

Austin, J. A.; Titze, D.

2016-12-01

Ice cover is shown to exhibit a strong linear sensitivity to air temperature. Upwards of 70% of ice cover variability on all of the Great Lakes can be explained in terms of air temperature, alone, and nearly 90% of ice cover variability can be explained in some lakes. Ice cover sensitivity to air temperature is high, and a difference in seasonally-averaged (Dec-May) air temperature on the order of 1°C to 2°C can be the difference between a low-ice year and a moderate- to high- ice year. The total amount of seasonal ice cover is most influenced by air temperatures during the meteorological winter, contemporaneous with the time of ice formation. Air temperature conditions during the pre-winter conditioning period and during the spring melting period were found to have less of an impact on seasonal ice cover. This is likely due to the fact that there is a negative feedback mechanism when heat loss goes toward cooling the lake, but a positive feedback mechanism when heat loss goes toward ice formation. Ice cover sensitivity relationships were compared between shallow coastal regions of the Great Lakes and similarly shallow smaller, inland lakes. It was found that the sensitivity to air temperature is similar between these coastal regions and smaller lakes, but that the absolute amount of ice that forms varies significantly between small lakes and the Great Lakes, and amongst the Great Lakes themselves. The Lake Superior application of the ROMS three-dimensional hydrodynamic numerical model verifies a deterministic linear relationship between air temperature and ice cover, which is also strongest around the period of ice formation. When the Lake Superior bathymetry is experimentally adjusted by a constant vertical multiplier, average lake depth is shown to have a nonlinear relationship with seasonal ice cover, and this nonlinearity may be associated with a nonlinear increase in the lake-wide volume of the surface mixed layer.

Comparative mapping of serotonin-immunoreactive neurons in the central nervous systems of nudibranch molluscs.

PubMed

Newcomb, James M; Fickbohm, David J; Katz, Paul S

2006-11-20

The serotonergic systems in nudibranch molluscs were compared by mapping the locations of serotonin-immunoreactive (5-HT-ir) neurons in 11 species representing all four suborders of the nudibranch clade: Dendronotoidea (Tritonia diomedea, Tochuina tetraquetra, Dendronotus iris, Dendronotus frondosus, and Melibe leonina), Aeolidoidea (Hermissenda crassicornis and Flabellina trophina), Arminoidea (Dirona albolineata, Janolus fuscus, and Armina californica), and Doridoidea (Triopha catalinae). A nomenclature is proposed to standardize reports of cell location in species with differing brain morphologies. Certain patterns of 5-HT immunoreactivity were found to be consistent for all species, such as the presence of 5-HT-ir neurons in the pedal and cerebral ganglia. Also, particular clusters of 5-HT-ir neurons in the anterior and posterior regions of the dorsal surface of the cerebral ganglion were always present. However, there were interspecies differences in the number of 5-HT-ir neurons in each cluster, and some clusters even exhibited strong intraspecies variability that was only weakly correlated with brain size. Phylogenetic analysis suggests that the presence of particular classes of 5-HT-ir neurons exhibits a great deal of homoplasy. The conserved features of the nudibranch serotonergic system presumably represent the shared ancestral structure, whereas the derived characters suggest substantial independent evolutionary changes in the number and presence of serotonergic neurons. Although a number of studies have demonstrated phylogenetic variability of peptidergic systems, this study suggests that serotonergic systems may also exhibit a high degree of homoplasy in some groups of organisms.

Penultimate Glacial-Interglacial Climate Variability in the Southern Great Plains of North America

NASA Astrophysics Data System (ADS)

Bartow-Gillies, E.; Maupin, C. R.; Roark, E. B.; Chou, Y. C.; White, K.; Kampen-Lewis, S. V.; Shen, C. C.

2017-12-01

Projections of changes in rainfall under future warming scenarios vary in their sign and intensity over the Southern Great Plains (SGP). A scarcity of local paleoclimate information before the Last Glacial Maximum (LGM) limits our understanding of regional climate responses to changes in mean state and forcing. Here, we present absolutely U/Th-dated oxygen and carbon isotope records from a calcite stalagmite near Georgetown, Texas (30°N, 98°W), spanning 98 to 209 kyr before present (kyr BP). SGP moisture is primarily sourced from the Gulf of Mexico, and precipitation exhibits clear seasonality, with a biannual rainy season divided into late boreal spring and fall. We interpret the oxygen isotopic composition of the stalagmite to reflect changes in rainwater δ18O composition, as well as cave temperature, through time. There are no clear kinetic isotope effects observed within the stalagmite. More negative (positive) δ18O values are a reflection of warmer and wetter (cooler and drier) conditions based on modern observations of rainwater δ18O at the study site. Variations in stalagmite δ13C may be driven by shifts in overlying vegetation type and changes in the rates of karst flow and prior calcite precipitation. The stalagmite records include Marine Isotope Stage (MIS) 5e, an interval where global temperatures may have been as much as 2°C warmer and sea level 4-6 m higher than present. Thus, our δ18O record provides context of unique importance for how SGP hydroclimate may respond to future warming. Prominent features in the δ18O record, including a warm and wet MIS 5e appear to be paced by precession, with the timing of δ18O minima (maxima) broadly consistent with that of maxima (minima) in monthly insolation at 30°N. The δ13C record exhibits a striking similarity to canonical, sawtooth records of glacial-interglacial variability, which suggests Great Plains vegetation communities may be sensitive to the status of Northern Hemisphere glaciation. Our SGP stalagmite records help to reveal the fundamental character of SGP climate response to glacial-interglacial forcings and provide evidence for increased precipitation under past warming conditions.

High Efficiency, Low Distortion 3D Diffusion Tensor Imaging with Variable Density Spiral Fast Spin Echoes (3D DW VDS RARE)

PubMed Central

Frank, Lawrence R.; Jung, Youngkyoo; Inati, Souheil; Tyszka, J. Michael; Wong, Eric C.

2009-01-01

We present an acquisition and reconstruction method designed to acquire high resolution 3D fast spin echo diffusion tensor images while mitigating the major sources of artifacts in DTI - field distortions, eddy currents and motion. The resulting images, being 3D, are of high SNR, and being fast spin echoes, exhibit greatly reduced field distortions. This sequence utilizes variable density spiral acquisition gradients, which allow for the implementation of a self-navigation scheme by which both eddy current and motion artifacts are removed. The result is that high resolution 3D DTI images are produced without the need for eddy current compensating gradients or B0 field correction. In addition, a novel method for fast and accurate reconstruction of the non-Cartesian data is employed. Results are demonstrated in the brains of normal human volunteers. PMID:19778618

Individual Movement Variability Magnitudes Are Explained by Cortical Neural Variability.

PubMed

Haar, Shlomi; Donchin, Opher; Dinstein, Ilan

2017-09-13

Humans exhibit considerable motor variability even across trivial reaching movements. This variability can be separated into specific kinematic components such as extent and direction that are thought to be governed by distinct neural processes. Here, we report that individual subjects (males and females) exhibit different magnitudes of kinematic variability, which are consistent (within individual) across movements to different targets and regardless of which arm (right or left) was used to perform the movements. Simultaneous fMRI recordings revealed that the same subjects also exhibited different magnitudes of fMRI variability across movements in a variety of motor system areas. These fMRI variability magnitudes were also consistent across movements to different targets when performed with either arm. Cortical fMRI variability in the posterior-parietal cortex of individual subjects explained their movement-extent variability. This relationship was apparent only in posterior-parietal cortex and not in other motor system areas, thereby suggesting that individuals with more variable movement preparation exhibit larger kinematic variability. We therefore propose that neural and kinematic variability are reliable and interrelated individual characteristics that may predispose individual subjects to exhibit distinct motor capabilities. SIGNIFICANCE STATEMENT Neural activity and movement kinematics are remarkably variable. Although intertrial variability is rarely studied, here, we demonstrate that individual human subjects exhibit distinct magnitudes of neural and kinematic variability that are reproducible across movements to different targets and when performing these movements with either arm. Furthermore, when examining the relationship between cortical variability and movement variability, we find that cortical fMRI variability in parietal cortex of individual subjects explained their movement extent variability. This enabled us to explain why some subjects performed more variable movements than others based on their cortical variability magnitudes. Copyright © 2017 the authors 0270-6474/17/379076-10$15.00/0.

Holocene Relative Sea-Level Changes from Near-, Intermediate-, and Far-Field Locations

NASA Astrophysics Data System (ADS)

Walker, J. S.; Khan, N.; Shaw, T.; Ashe, E.; Vacchi, M.; Peltier, W. R.; Kopp, R. E.; Horton, B.

2015-12-01

Holocene relative sea-level (RSL) records exhibit spatial and temporal variability that arises mainly from the interaction of eustatic (land ice volume and thermal expansion) and isostatic (glacio- and hydro-) factors. We fit RSL histories from near-, intermediate-, and far-field locations with noisy-input Gaussian process models to assess rates of RSL change from selected study areas. Records from near-field regions (e.g., Antarctica, Greenland, Canada, Sweden, and Scotland) reveal a complex pattern of RSL fall from a maximum marine limit due to the net effect of eustatic sea-level rise and glacial-isostatic uplift with rates of RSL fall as great as -69 ± 9 m/ka. Intermediate-field regions (e.g., mid-Atlantic and Pacific coasts of the United States, Netherlands, Southern France, St. Croix) display variable rates of RSL rise from the cumulative effect of isostatic and eustatic factors. Fast rates of RSL rise (up to 10 ± 1 m/ka) are found in the early Holocene in regions near the center of forebulge collapse. Far-field RSL records exhibit a mid-Holocene highstand, the timing (between 8 and 4 ka) and magnitude (between <1 and 6 m) of which varies across South America, Africa, Asia and Australia regions.

Progress on upwelling studies in the China seas

NASA Astrophysics Data System (ADS)

Hu, Jianyu; Wang, Xiao Hua

2016-09-01

East Asian marginal seas surrounding China exhibit rich ocean upwelling, mostly in response to the southwesterly summer monsoon. Upwelling in the China seas, namely, the South China Sea, the Taiwan Strait, the East China Sea, the Yellow Sea, and the Bohai Sea, has become increasingly important because the potential changes in the upwelling may have dramatic ecosystem, socioeconomic, and climate impacts. This paper reviews the progress of upwelling studies in the China seas since the year 2000, by presenting the principal characteristics and new understanding of 12 major upwelling regions in the China seas. Upwelling exhibits long-term variability at intraseasonal to multidecadal scales as well as short-term variability frequently caused by tropical cyclones. It is also associated with the El Niño-Southern Oscillation, local environmental variation, and biogeochemical factors. The coastal upwelling around Hainan Island and the upwelling or cold dome northeast of Taiwan Island are specifically highlighted because they have attracted great interest for decades. This paper summarizes upwelling mechanisms in terms of wind, topography, tide, stratification, and background flow, with applications mostly to the China seas. Finally, we propose some topics for future upwelling research, i.e., potential intensification of coastal upwelling under global climate change, downwelling, intrusion of upwelling into coastal embayments, and the influence of upwelling on fishery and biogeochemical processes.

Satellite Remote Sensing: Aerosol Measurements

NASA Technical Reports Server (NTRS)

Kahn, Ralph A.

2013-01-01

Aerosols are solid or liquid particles suspended in the air, and those observed by satellite remote sensing are typically between about 0.05 and 10 microns in size. (Note that in traditional aerosol science, the term "aerosol" refers to both the particles and the medium in which they reside, whereas for remote sensing, the term commonly refers to the particles only. In this article, we adopt the remote-sensing definition.) They originate from a great diversity of sources, such as wildfires, volcanoes, soils and desert sands, breaking waves, natural biological activity, agricultural burning, cement production, and fossil fuel combustion. They typically remain in the atmosphere from several days to a week or more, and some travel great distances before returning to Earth's surface via gravitational settling or washout by precipitation. Many aerosol sources exhibit strong seasonal variability, and most experience inter-annual fluctuations. As such, the frequent, global coverage that space-based aerosol remote-sensing instruments can provide is making increasingly important contributions to regional and larger-scale aerosol studies.

Regional inequalities in premature mortality in Great Britain

PubMed Central

Laroze, Denise; Neumayer, Eric

2018-01-01

Premature mortality exhibits strong spatial patterns in Great Britain. Local authorities that are located further North and West, that are more distant from its political centre London and that are more urban tend to have a higher premature mortality rate. Premature mortality also tends to cluster among geographically contiguous and proximate local authorities. We develop a novel analytical research design that relies on spatial pattern recognition to demonstrate that an empirical model that contains only socio-economic variables can eliminate these spatial patterns almost entirely. We demonstrate that socioeconomic factors across local authority districts explain 81 percent of variation in female and 86 percent of variation in male premature mortality in 2012–14. As our findings suggest, policy-makers cannot hope that health policies alone suffice to significantly reduce inequalities in health. Rather, it requires strong efforts to reduce the inequalities in socio-economic factors, or living conditions for short, in order to overcome the spatial disparities in health, of which premature mortality is a clear indication. PMID:29489918

Great Basin vegetation response to groundwater fluctuation, climate variability, and previous land cultivation: The application of multitemporal measurements from remote sensing data to regional vegetation dynamics

NASA Astrophysics Data System (ADS)

Elmore, Andrew James

The conversion of large natural basins to managed watersheds for the purpose of providing water to urban centers has had a negative impact on semiarid ecosystems, worldwide. We view semiarid plant communities as being adapted to short, regular periods of drought. However, human induced changes in the water balance often remove these systems from the range of natural variability that has been historically established. This thesis explores vegetation changes over a 13-yr period for Owens Valley, in eastern California. Using remotely sensed measurements of vegetation cover, an extensive vegetation survey, field data and observations, precipitation records, and data on water table depth, I identify the key modes of response of xeric, phreatophytic, and exotic Great Basin plant communities. Three specific advancements were reached as a result of this work. (1) A change classification technique was developed that was used to separate regions of land-cover that were dependent on precipitation from regions dependent on groundwater. This technique utilized Spectral Mixture Analysis of annually acquired Landsat Thematic Mapper remote sensing data, to retrieve regional estimates of percent vegetation cover. (2) A threshold response related to depth-to-water dependence was identified for phreatophytic Alkali Meadow communities. Plant communities that were subject to groundwater depths below this threshold exhibited greater invasion by precipitation sensitive plants. (3) The floristic differences between previously cultivated and uncultivated land were found to account for an increased sensitivity of plant communities to precipitation variability. Through (2) and (3), two human influences (groundwater decline and previous land cultivation) were shown to alter land cover such that the land became more sensitive to precipitation change. Climate change predictions include a component of increased climate variability for the western United States; therefore, these results place serious doubt on the sustainability of human activities in this region. The results from this work broadly cover topics from remote sensing techniques to the ecology of Great Basin plant communities and are applicable wherever large regions of land are being managed in an era of changing environmental conditions.

Genetic variability among elite popcorn lines based on molecular and morphoagronomic characteristics.

PubMed

Dos Santos, J F; Mangolin, C A; Machado, M F P S; Scapim, C A; Giordani, W; Gonçalves, L S A

2017-06-29

Knowledge of genetic diversity among genotypes and relationships among elite lines is of great importance for the development of breeding programs. Therefore, the objective of this study was to evaluate genetic variability based on the morphoagronomic and molecular characterization of 18 elite popcorn (Zea mays var. everta) lines to be used by Universidade Estadual de Maringá breeding programs. We used 31 microsatellite primers (widely distributed in the genome), and 16 morphological descriptors (including the resistance to maize white spot, common rust, polysora rust of maize, cercospora and leaf blights). The molecular data revealed variability among the lines, which were divided into four groups that were partially concordant with unweighted pair group method with arithmetic mean (UPMGA) and Bayesian clusters. The lines G3, G4, G11, and G13 exhibited favorable morphological characters and low disease incidence rates. The four groups were confirmed using the Gower distance in the UPGMA cluster; however, there was no association with the dissimilarity patterns obtained using the molecular data. The absence of a correlation suggests that both characterizations (morphoagronomic and molecular) are important for discriminating among elite popcorn lines.

Evidence of at least two evolutionary lineages in Melipona subnitida (Apidae, Meliponini) suggested by mtDNA variability and geometric morphometrics of forewings.

PubMed

Bonatti, Vanessa; Simões, Zilá Luz Paulino; Franco, Fernando Faria; Francoy, Tiago Mauricio

2014-01-01

Melipona subnitida, a tropical stingless bee, is an endemic species of the Brazilian northeast and exhibits great potential for honey and pollen production in addition to its role as one of the main pollinators of the Caatinga biome. To understand the genetic structure and better assist in the conservation of this species, we characterized the population variability of M. subnitida using geometric morphometrics of the forewing and cytochrome c oxidase I gene fragment sequencing. We collected workers from six localities in the northernmost distribution. Both methodologies indicated that the variability among the sampled populations is related both to the environment in which samples were collected and the geographical distance between the sampling sites, indicating that differentiation among the populations is due to the existence of at least evolutionary lineages. Molecular clock data suggest that this differentiation may have begun in the middle Pleistocene, approximately 396 kya. The conservation of all evolutionary lineages is important since they can present differential resistance to environmental changes, as resistance to drought and diseases.

Evidence of at least two evolutionary lineages in Melipona subnitida (Apidae, Meliponini) suggested by mtDNA variability and geometric morphometrics of forewings

NASA Astrophysics Data System (ADS)

Bonatti, Vanessa; Simões, Zilá Luz Paulino; Franco, Fernando Faria; Francoy, Tiago Mauricio

2014-01-01

Melipona subnitida, a tropical stingless bee, is an endemic species of the Brazilian northeast and exhibits great potential for honey and pollen production in addition to its role as one of the main pollinators of the Caatinga biome. To understand the genetic structure and better assist in the conservation of this species, we characterized the population variability of M. subnitida using geometric morphometrics of the forewing and cytochrome c oxidase I gene fragment sequencing. We collected workers from six localities in the northernmost distribution. Both methodologies indicated that the variability among the sampled populations is related both to the environment in which samples were collected and the geographical distance between the sampling sites, indicating that differentiation among the populations is due to the existence of at least evolutionary lineages. Molecular clock data suggest that this differentiation may have begun in the middle Pleistocene, approximately 396 kya. The conservation of all evolutionary lineages is important since they can present differential resistance to environmental changes, as resistance to drought and diseases.

Modeling of Rolling Element Bearing Mechanics: Computer Program Updates

NASA Technical Reports Server (NTRS)

Ryan, S. G.

1997-01-01

The Rolling Element Bearing Analysis System (REBANS) extends the capability available with traditional quasi-static bearing analysis programs by including the effects of bearing race and support flexibility. This tool was developed under contract for NASA-MSFC. The initial version delivered at the close of the contract contained several errors and exhibited numerous convergence difficulties. The program has been modified in-house at MSFC to correct the errors and greatly improve the convergence. The modifications consist of significant changes in the problem formulation and nonlinear convergence procedures. The original approach utilized sequential convergence for nested loops to achieve final convergence. This approach proved to be seriously deficient in robustness. Convergence was more the exception than the rule. The approach was changed to iterate all variables simultaneously. This approach has the advantage of using knowledge of the effect of each variable on each other variable (via the system Jacobian) when determining the incremental changes. This method has proved to be quite robust in its convergence. This technical memorandum documents the changes required for the original Theoretical Manual and User's Manual due to the new approach.

Seasonal weather-related decision making for cattle production in the Northern Great Plains

USDA-ARS?s Scientific Manuscript database

High inter-annual variability of seasonal weather patterns can greatly affect forage and therefore livestock production in the Northern Great Plains. This variability can make it difficult for ranchers to set yearly stocking rates, particularly in advance of the grazing season. To better understand ...

A Multi-Phased Evaluation of the Impact of a Non-School Science Exhibition.

ERIC Educational Resources Information Center

Fortner, Rosanne W.

The impact of "The Great Lake Erie," an outreach program that aimed to improve visitor knowledge and attitudes about Lake Erie, is discussed in this evaluative study. "The Great Lake Erie" was presented as a two-part program consisting of a lecture and demonstration stage presentation and a series of exhibits. The program was…

Smolting in coastal cutthroat trout Onchorhynchus clarkii clarkii

USGS Publications Warehouse

Zydlewski, Joseph D.; Zydlewski, G.; Kennedy, B.; Gale, W.

2014-01-01

Gill Na+, K+-ATPase activity, condition factor and seawater (SW) challenges were used to assess the development of smolt characteristics in a cohort of hatchery coastal cutthroat trout Oncorhynchus clarkii clarkii from the Cowlitz River in Washington State, U.S.A. Gill Na+, K+-ATPase activity increased slightly in the spring, coinciding with an increase in hypo-osmoregulatory ability. These changes were of lesser magnitude than are observed in other salmonine species. Even at the peak of tolerance, these fish exhibited notable osmotic perturbations in full strength SW. Condition factor in these hatchery fish declined steadily through the spring. Wild captured migrants from four tributaries of the Columbia River had moderately elevated gill Na+, K+-ATPase activity, consistent with smolt development and with greater enzyme activity than autumn captured juveniles from one of the tributaries, Abernathy Creek. Migrant fish also had reduced condition factor. General linear models of 7 years of data from Abernathy Creek suggest that yearly variation, advancing photoperiod (as ordinal date) and fish size (fork length) were significant factors for predicting gill Na+, K+-ATPase activity in these wild fish. Both yearly variation and temperature were significant factors for predicting condition factor. These results suggest that coastal O. c. clarkii exhibit weakly developed characteristics of smolting. These changes are influenced by environmental conditions with great individual variation. The data suggest great physiological plasticity consistent with the variable life-history tactics observed in this species.

Le Conte's sparrows breeding in Conservation Reserve Program fields: precipitation and patterns of population change

USGS Publications Warehouse

Igl, Lawrence D.; Johnson, Douglas H.

1999-01-01

The climate of the North American Great Plains is highly dynamic, with great year-to-year variability in precipitation and periodic, often extreme, wet and dry cycles (Bragg 1995). Drought is a major force of ecological disturbance on the Great Plains and has played a key role in directing the evolution of the grassland biota of this region (Knopf and Samson 1997). Although grassland birds may differ in their responses to enviromenental variations (Rotenberry and Wiens 1991), climatic variability and concomitant unpredictability of resources strongly influence populations of grassland birds across space and time (Wiens 1974, 1986; Cody 1985). Not surprisingly, breeding bird populations on the Great Plains are highly dynamic, exhibiting considerable annual variation in composition, abundance, and distribution (Johnson and Grier 1988, George et al. 1992, Zimmerman 1992, Igl and Johnson 1997). Recently, interest in grassland birds has increased with the recognition that many species are declining both continentally (Droege and Sauer 1994) and globally (Goriup 1988). Identification of the specific factors associated with grassland bird declines in North America, however, remains largely enigmatic (Herkert 1997), and it is complicated by the considerable annual fluctuations in grassland bird distribution and abundance (Igl and Johnson 1997). Although there is evidence that land-use changes on the breeding grounds may have contributed to grassland bird declines (e.g., Igl and Johnson 1997), there also is an indication that long-term drought conditions may have influenced recent population changes of some breeding birds on the Great Plains (Droege and Sauer 1989, Peterjohn and Sauer 1993, Bethke and Nudds 1995, Igl and Johnson 1997). Le Conte's Sparrow (Ammodramus leconteii) is a secretive grassland bird that breeds in central and southern Canada and the northcentral United States (Murray 1969). It winters primarily in the southern United States (Peterson 1980, 1990). Like populations of many grassland breeding birds in North America (Fretwell 1986, Igl and Johnson 1997), Le Conte's Sparrow populations exhibit numerical highs and lows depending on local moisture conditions (Peabody 1901, Stewart 1975, Knapton 1979, Zimmer 1979, Madden 1996). This observation, however, is based largely on anecdotal evidence or short-term observations. Long-term studies of Le Conte's Sparrow populations are limited. Le Conte's Sparrow is poorly represented on the North American Breeding Bird Survey (BBS) because of small sample sizes, poor coverage in the northern portion of its breeding range, and the species' furtive behavior (Sauer et al. 1995). Moreover, dramatic fluctuations in Le Conte's Sparrow abundance tend to obscure the species' long-term population trends on the BBS (Sauer et al. 1995). In this paper we examine long-term population changes of Le Conte's Sparrows breeding in perennial grassland fields enrolled in the Conservation Reserve Program (CRP) on the northern Great Plains. We discuss patterns of population change of Le Conte's Sparrows associated with changes in precipitation and moisture conditions.

Pelvic incidence variation among individuals: functional influence versus genetic determinism.

PubMed

Chen, Hong-Fang; Zhao, Chang-Qing

2018-03-20

Pelvic incidence has become one of the most important sagittal parameters in spinal surgery. Despite its great importance, pelvic incidence can vary from 33° to 85° in the normal population. The reasons for this great variability in pelvic incidence remain unexplored. The objective of this article is to present some possible interpretations for the great variability in pelvic incidence under both normal and pathological conditions and to further understand the determinants of pelvic incidence from the perspective of the functional requirements for bipedalism and genetic backgrounds via a literature review. We postulate that both pelvic incidence and pelvic morphology may be genetically predetermined, and a great variability in pelvic incidence may already exist even before birth. This great variability may also serve as a further reminder that the sagittal profile, bipedal locomotion mode, and genetic background of every individual are unique and specific, and clinicians should avoid making universally applying broad generalizations of pelvic incidence. Although PI is an important parameter and there are many theories behind its variability, we still do not have clear mechanistic answers.

Historical sediment mercury deposition trends for South Dakota lakes

USGS Publications Warehouse

Squillace, Maria K.; Sieverding, Heidi L.; Betemariam, Hailemelekot H.; Urban, Noel R.; Penn, Michael R.; DeSutter, Thomas M.; Chipps, Steven R.; Stone, James J.

2018-01-01

PurposeSelect South Dakota, USA water bodies, including both natural lakes and man-made impoundments, were sampled and analyzed to assess mercury (Hg) dynamics and historical patterns of total Hg deposition.Materials and methodsSediment cores were collected from seven South Dakota lakes. Mercury concentrations and flux profiles were determined using lead (210Pb) dating and sedimentation rates.Results and discussionMost upper lake sediments contained variable heavy metal concentrations, but became more consistent with depth and age. Five of the seven lakes exhibited Hg accumulation fluxes that peaked between 1920 and 1960, while the remaining two lakes exhibited recent (1995–2009) Hg flux spikes. Historical sediment accumulation rates and Hg flux profiles demonstrate similar peak and stabilized values. Mercury in the sampled South Dakota lakes appears to emanate from watershed transport due to erosion from agricultural land use common to the Northern Great Plains.ConclusionsFor sampled South Dakota lakes, watershed inputs are more significant sources of Hg than atmospheric deposition.

Understanding differences in electronic health record (EHR) use: linking individual physicians' perceptions of uncertainty and EHR use patterns in ambulatory care.

PubMed

Lanham, Holly Jordan; Sittig, Dean F; Leykum, Luci K; Parchman, Michael L; Pugh, Jacqueline A; McDaniel, Reuben R

2014-01-01

Electronic health records (EHR) hold great promise for managing patient information in ways that improve healthcare delivery. Physicians differ, however, in their use of this health information technology (IT), and these differences are not well understood. The authors study the differences in individual physicians' EHR use patterns and identify perceptions of uncertainty as an important new variable in understanding EHR use. Qualitative study using semi-structured interviews and direct observation of physicians (n=28) working in a multispecialty outpatient care organization. We identified physicians' perceptions of uncertainty as an important variable in understanding differences in EHR use patterns. Drawing on theories from the medical and organizational literatures, we identified three categories of perceptions of uncertainty: reduction, absorption, and hybrid. We used an existing model of EHR use to categorize physician EHR use patterns as high, medium, and low based on degree of feature use, level of EHR-enabled communication, and frequency that EHR use patterns change. Physicians' perceptions of uncertainty were distinctly associated with their EHR use patterns. Uncertainty reductionists tended to exhibit high levels of EHR use, uncertainty absorbers tended to exhibit low levels of EHR use, and physicians demonstrating both perspectives of uncertainty (hybrids) tended to exhibit medium levels of EHR use. We find evidence linking physicians' perceptions of uncertainty with EHR use patterns. Study findings have implications for health IT research, practice, and policy, particularly in terms of impacting health IT design and implementation efforts in ways that consider differences in physicians' perceptions of uncertainty.

Modeling the contributions of global air temperature, synoptic-scale phenomena and soil moisture to near-surface static energy variability using artificial neural networks

NASA Astrophysics Data System (ADS)

Pryor, Sara C.; Sullivan, Ryan C.; Schoof, Justin T.

2017-12-01

The static energy content of the atmosphere is increasing on a global scale, but exhibits important subglobal and subregional scales of variability and is a useful parameter for integrating the net effect of changes in the partitioning of energy at the surface and for improving understanding of the causes of so-called warming holes (i.e., locations with decreasing daily maximum air temperatures (T) or increasing trends of lower magnitude than the global mean). Further, measures of the static energy content (herein the equivalent potential temperature, θe) are more strongly linked to excess human mortality and morbidity than air temperature alone, and have great relevance in understanding causes of past heat-related excess mortality and making projections of possible future events that are likely to be associated with negative human health and economic consequences. New nonlinear statistical models for summertime daily maximum and minimum θe are developed and used to advance understanding of drivers of historical change and variability over the eastern USA. The predictor variables are an index of the daily global mean temperature, daily indices of the synoptic-scale meteorology derived from T and specific humidity (Q) at 850 and 500 hPa geopotential heights (Z), and spatiotemporally averaged soil moisture (SM). SM is particularly important in determining the magnitude of θe over regions that have previously been identified as exhibiting warming holes, confirming the key importance of SM in dictating the partitioning of net radiation into sensible and latent heat and dictating trends in near-surface T and θe. Consistent with our a priori expectations, models built using artificial neural networks (ANNs) out-perform linear models that do not permit interaction of the predictor variables (global T, synoptic-scale meteorological conditions and SM). This is particularly marked in regions with high variability in minimum and maximum θe, where more complex models built using ANN with multiple hidden layers are better able to capture the day-to-day variability in θe and the occurrence of extreme maximum θe. Over the entire domain, the ANN with three hidden layers exhibits high accuracy in predicting maximum θe > 347 K. The median hit rate for maximum θe > 347 K is > 0.60, while the median false alarm rate is ≈ 0.08.

Urban airborne matter in central and southern Chile: Effects of meteorological conditions on fine and coarse particulate matter

NASA Astrophysics Data System (ADS)

Yáñez, Marco A.; Baettig, Ricardo; Cornejo, Jorge; Zamudio, Francisco; Guajardo, Jorge; Fica, Rodrigo

2017-07-01

Air pollution is one of the major global environmental problems affecting human health and life quality. Many cities of Chile are heavily polluted with PM2.5 and PM10, mainly in the cold season, and there is little understanding of how the variation in particle matter differs between cities and how this is affected by the meteorological conditions. The objective of this study was to assess the effect of meteorological variables on respirable particulate matter (PM) of the main cities in the central-south valley of Chile during the cold season (May to August) between 2014 and 2016. We used hourly PM2.5 and PMcoarse (PM10- PM2.5) information along with wind speed, temperature and relative humidity, and other variables derived from meteorological parameters. Generalized additive models (GAMs) were fitted for each of the eight cities selected, covering a latitudinal range of 929 km, from Santiago to Osorno. Great variation in PM was found between cities during the cold months, and that variation exhibited a marked latitudinal pattern. Overall, the more northerly cities tended to be less polluted in PM2.5 and more polluted in PMcoarse than the more southerly cities, and vice versa. The results show that other derived variables from meteorology were better related with PM than the use of traditional daily means. The main variables selected with regard to PM2.5 content were mean wind speed and minimum temperature (negative relationship). Otherwise, the main variables selected with regard to PMcoarse content were mean wind speed (negative), and the daily range in temperature (positive). Variables derived from relative humidity contributed differently to the models, having a higher effect on PMcoarse than PM2.5, and exhibiting both negative and positive effects. For the different cities the deviance explained by the GAMs ranged from 37.6 to 79.1% for PM2.5 and from 18.5 to 63.7% for PMcoarse. The percentage of deviance explained by the models for PM2.5 exhibited a latitudinal pattern, which was not observed in PMcoarse. This highlights the greater predictability of PM2.5 according to meteorological parameters in the cities to the south. Southern cities located spatially close to one another had similar patterns in both the selected variables for the models and the trends. The meteorological factor influencing the cities had a major impact on PM concentrations. The findings of this study may aid understanding of PM variation across the country, in the way of improving forecasting models.

Accounting for inter-annual and seasonal variability in regionalization of hydrologic response in the Great Lakes basin

NASA Astrophysics Data System (ADS)

Kult, J. M.; Fry, L. M.; Gronewold, A. D.

2012-12-01

Methods for predicting streamflow in areas with limited or nonexistent measures of hydrologic response typically invoke the concept of regionalization, whereby knowledge pertaining to gauged catchments is transferred to ungauged catchments. In this study, we identify watershed physical characteristics acting as primary drivers of hydrologic response throughout the US portion of the Great Lakes basin. Relationships between watershed physical characteristics and hydrologic response are generated from 166 catchments spanning a variety of climate, soil, land cover, and land form regimes through regression tree analysis, leading to a grouping of watersheds exhibiting similar hydrologic response characteristics. These groupings are then used to predict response in ungauged watersheds in an uncertainty framework. Results from this method are assessed alongside one historical regionalization approach which, while simple, has served as a cornerstone of Great Lakes regional hydrologic research for several decades. Our approach expands upon previous research by considering multiple temporal characterizations of hydrologic response. Due to the substantial inter-annual and seasonal variability in hydrologic response observed over the Great Lakes basin, results from the regression tree analysis differ considerably depending on the level of temporal aggregation used to define the response. Specifically, higher levels of temporal aggregation for the response metric (for example, indices derived from long-term means of climate and streamflow observations) lead to improved watershed groupings with lower within-group variance. However, this perceived improvement in model skill occurs at the cost of understated uncertainty when applying the regression to time series simulations or as a basis for model calibration. In such cases, our results indicate that predictions based on long-term characterizations of hydrologic response can produce misleading conclusions when applied at shorter time steps. This study suggests that measures of hydrologic response quantified at these shorter time steps may provide a more robust basis for making predictions in applications of water resource management, model calibration and simulations, and human health and safety.

KSC-2014-3129

NASA Image and Video Library

2014-07-03

CAPE CANAVERAL, Fla. – Former NASA astronaut Tom Jones welcomes visitors to the grand opening of the Great Balls of Fire exhibit at NASA’s Kennedy Space Center Visitor Complex in Florida. Great Balls of Fire shares the story of the origins of our solar system, asteroids and comets and their possible impacts and risks. The 1,500-square-foot exhibit, located in the East Gallery of the IMAX theatre at the visitor complex, features several interactive displays, real meteorites and replica asteroid models. The exhibit is a production of The Space Science Institute's National Center for Interactive Learning. It is a traveling exhibition that also receives funding from NASA and the National Science Foundation. Photo credit: NASA/Daniel Casper

Mechanisms driving recruitment variability in fish: comparisons between the Laurentian Great Lakes and marine systems

USGS Publications Warehouse

Pritt, Jeremy J.; Roseman, Edward F.; O'Brien, Timothy P.

2014-01-01

In his seminal work, Hjort (in Fluctuations in the great fisheries of Northern Europe. Conseil Parmanent International Pour L'Exploration De La Mar. Rapports et Proces-Verbaux, 20: 1–228, 1914) observed that fish population levels fluctuated widely, year-class strength was set early in life, and egg production by adults could not alone explain variability in year-class strength. These observations laid the foundation for hypotheses on mechanisms driving recruitment variability in marine systems. More recently, researchers have sought to explain year-class strength of important fish in the Laurentian Great Lakes and some of the hypotheses developed for marine fisheries have been transferred to Great Lakes fish. We conducted a literature review to determine the applicability of marine recruitment hypotheses to Great Lakes fish. We found that temperature, interspecific interactions, and spawner effects (abundance, age, and condition of adults) were the most important factors in explaining recruitment variability in Great Lakes fish, whereas relatively fewer studies identified bottom-up trophodynamic factors or hydrodynamic factors as important. Next, we compared recruitment between Great Lakes and Baltic Sea fish populations and found no statistical difference in factors driving recruitment between the two systems, indicating that recruitment hypotheses may often be transferable between Great Lakes and marine systems. Many recruitment hypotheses developed for marine fish have yet to be applied to Great Lakes fish. We suggest that future research on recruitment in the Great Lakes should focus on forecasting the effects of climate change and invasive species. Further, because the Great Lakes are smaller and more enclosed than marine systems, and have abundant fishery-independent data, they are excellent candidates for future hypothesis testing on recruitment in fish.

Global distribution and epidemiologic associations of Escherichia coli clonal group A, 1998-2007.

PubMed

Johnson, James R; Menard, Megan E; Lauderdale, Tsai-Ling; Kosmidis, Chris; Gordon, David; Collignon, Peter; Maslow, Joel N; Andrasević, Arjana Tambić; Kuskowski, Michael A

2011-11-01

Escherichia coli clonal group A (CGA) was first reported in 2001 as an emerging multidrug-resistant extraintestinal pathogen. Because CGA has considerable implications for public health, we examined the trends of its global distribution, clinical associations, and temporal prevalence for the years 1998-2007. We characterized 2,210 E. coli extraintestinal clinical isolates from 32 centers on 6 continents by CGA status for comparison with trimethoprim/sulfamethoxazole (TMP/SMZ) phenotype, specimen type, inpatient/outpatient source, and adult/child host; we adjusted for clustering by center. CGA prevalence varied greatly by center and continent, was strongly associated with TMP/SMZ resistance but not with other epidemiologic variables, and exhibited no temporal prevalence trend. Our findings indicate that CGA is a prominent, primarily TMP/SMZ-resistant extraintestinal pathogen concentrated within the Western world, with considerable pathogenic versatility. The stable prevalence of CGA over time suggests full emergence by the late 1990s, followed by variable endemicity worldwide as an antimicrobial drug-resistant public health threat.

Composition and temporal stability of turf sediments on inner-shelf coral reefs.

PubMed

Gordon, Sophie E; Goatley, Christopher H R; Bellwood, David R

2016-10-15

Elevated sediment loads within the epilithic algal matrix (EAM) of coral reefs can increase coral mortality and inhibit herbivory. Yet the composition, distribution and temporal variability of EAM sediment loads are poorly known, especially on inshore reefs. This study quantified EAM sediment loads (including organic particulates) and algal length across the reef profile of two bays at Orpheus Island (inner-shelf Great Barrier Reef) over a six month period. We examined the total sediment mass, organic load, carbonate and silicate content, and the particle sizes of EAM sediments. Throughout the study period, all EAM sediment variables exhibited marked variation among reef zones. However, EAM sediment loads and algal length were consistent between bays and over time, despite major seasonal variation in climate including a severe tropical cyclone. This study provides a comprehensive description of EAM sediments on inshore reefs and highlights the exceptional temporal stability of EAM sediments on coral reefs. Copyright © 2016 Elsevier Ltd. All rights reserved.

Musculo-Skeletal Abnormalities in Patients with Marfan Syndrome

PubMed Central

Al Kaissi, Ali; Zwettler, Elisabeth; Ganger, Rudolf; Schreiner, Simone; Klaushofer, Klaus; Grill, Franz

2013-01-01

Background A leptosomic body type is tall and thin with long hands. Marfanoid features may be familial in nature or pathological, as occurs in congenital contractual arachnodactyly (Beal’s syndrome) and Shprintzen-Goldberg syndrome mimicking some of the changes of Marfan syndrome, although not accompanied by luxation of lens and dissecting aneurysm of aorta. Methods In this article we collected eight patients who were consistent with the diagnosis of Marfan syndrome via phenotypic and genotypic characterization. Results Our patients manifested a constellation of variable presentations of musculo-skeletal abnormalities ranging from developmental dysplasia of the hip, protrusio acetabuli, leg length inequality, patellar instability, scoliosis, to early onset osteoarthritis. Each abnormality has been treated accordingly. Conclusion This is the first paper which includes the diagnosis and the management of the associated musculo-skeletal abnormalities in patients with Marfan syndrome, stressing that patients with Marfan syndrome are exhibiting great variability in the natural history and the severity of musculo-skeletal abnormalities. PMID:23399831

Diversity in shortjaw cisco (Coregonus zenithicus) in North America

USGS Publications Warehouse

Todd, T.N.; Steinhilber, M.

2002-01-01

Shortjaw cisco (Coregonus zenithicus) exhibit morphological variability across their geographic range in North America and could comprise more than one distinct morph or taxon. To investigate this, principal components analysis was applied to a data set that consisted of four variables from nine localities. All data were obtained from digital images of the specimens and the excised first gill arch. Confidence ellipses (95%) about the means of bivariate distributions of the principal components revealed that some populations were distinct from the others, but a continuity of overlap clouded understanding of pattern among the variation. Most populations had more and longer gillrakers than shortjaw cisco from George Lake (Manitoba) and Basswood Lake (Ontario) that had fewer and shorter gillrakers. This analysis supports the existence of a short- and few-rakered morph and a long- and many-rakered morph. However, most populations of shortjaw cisco from the Great Lakes across Canada to the Arctic share a similar morphology and likely represent a single, widespread species.

The Impact of the Great Exhibition of 1851 on the Development of Technical Education during the Second Half of the Nineteenth Century

ERIC Educational Resources Information Center

Walker, Martyn A.

2015-01-01

This paper examines the contribution made by the mechanics' institute movement in Britain just prior to, and following, the opening of the Great Exhibition of 1851 in London. It argues that far from making little contribution to education, as often portrayed by historians, the movement was ideally positioned to respond to the findings of the…

Spatial and Temporal Variability and Trends in 2001-2016 Global Fire Activity

NASA Astrophysics Data System (ADS)

Earl, Nick; Simmonds, Ian

2018-03-01

Fire regimes across the globe have great spatial and temporal variability, and these are influence by many factors including anthropogenic management, climate, and vegetation types. Here we utilize the satellite-based "active fire" product, from Moderate Resolution Imaging Spectroradiometer (MODIS) sensors, to statistically analyze variability and trends in fire activity from the global to regional scales. We split up the regions by economic development, region/geographical land use, clusters of fire-abundant areas, or by religious/cultural influence. Weekly cycle tests are conducted to highlight and quantify part of the anthropogenic influence on fire regime across the world. We find that there is a strong statistically significant decline in 2001-2016 active fires globally linked to an increase in net primary productivity observed in northern Africa, along with global agricultural expansion and intensification, which generally reduces fire activity. There are high levels of variability, however. The large-scale regions exhibit either little change or decreasing in fire activity except for strong increasing trends in India and China, where rapid population increase is occurring, leading to agricultural intensification and increased crop residue burning. Variability in Canada has been linked to a warming global climate leading to a longer growing season and higher fuel loads. Areas with a strong weekly cycle give a good indication of where fire management is being applied most extensively, for example, the United States, where few areas retain a natural fire regime.

Early emergence of anthropogenically forced heat waves in the western United States and Great Lakes

NASA Astrophysics Data System (ADS)

Lopez, Hosmay; West, Robert; Dong, Shenfu; Goni, Gustavo; Kirtman, Ben; Lee, Sang-Ki; Atlas, Robert

2018-05-01

Climate projections for the twenty-first century suggest an increase in the occurrence of heat waves. However, the time at which externally forced signals of anthropogenic climate change (ACC) emerge against background natural variability (time of emergence (ToE)) has been challenging to quantify, which makes future heat-wave projections uncertain. Here we combine observations and model simulations under present and future forcing to assess how internal variability and ACC modulate US heat waves. We show that ACC dominates heat-wave occurrence over the western United States and Great Lakes regions, with ToE that occurred as early as the 2020s and 2030s, respectively. In contrast, internal variability governs heat waves in the northern and southern Great Plains, where ToE occurs in the 2050s and 2070s; this later ToE is believed to be a result of a projected increase in circulation variability, namely the Great Plain low-level jet. Thus, greater mitigation and adaptation efforts are needed in the Great Lakes and western United States regions.

Phase Transition between Black and Blue Phosphorenes: A Quantum Monte Carlo Study

NASA Astrophysics Data System (ADS)

Li, Lesheng; Yao, Yi; Reeves, Kyle; Kanai, Yosuke

Phase transition of the more common black phosphorene to blue phosphorene is of great interest because they are predicted to exhibit unique electronic and optical properties. However, these two phases are predicted to be separated by a rather large energy barrier. In this work, we study the transition pathway between black and blue phosphorenes by using the variable cell nudge elastic band method combined with density functional theory calculation. We show how diffusion quantum Monte Carlo method can be used for determining the energetics of the phase transition and demonstrate the use of two approaches for removing finite-size errors. Finally, we predict how applied stress can be used to control the energetic balance between these two different phases of phosphorene.

Exploring the hidden shallows: extensive reef development and resilience within the turbid nearshore Great Barrier Reef

NASA Astrophysics Data System (ADS)

Morgan, Kyle; Perry, Chris; Smithers, Scott; Johnson, Jamie; Daniell, James

2016-04-01

Mean coral cover on Australia's Great Barrier Reef (GBR) has reportedly declined by over 15% during the last 30 years. Climate change events and outbreaks of coral disease have been major drivers of degradation, often exacerbating the stresses caused by localised human activities (e.g. elevated sediment and nutrient inputs). Here, however, in the first assessment of nearshore reef occurrence and ecology across meaningful spatial scales (15.5 sq km), we show that areas of the GBR shelf have exhibited strong intra-regional variability in coral resilience to declining water quality. Specifically, within the highly-turbid "mesophotic" nearshore (<10 m depth) of the central GBR, where terrigenous seafloor sediments are persistently resuspended by wave processes, coral cover averages 38% (twice that reported on mid- and outer-shelf reefs). Of the mapped area, 11% of the seafloor has distinct reef or coral community cover, a density comparable to that measured across the entire GBR shelf (9%). Identified coral taxa (21 genera) exhibited clear depth-stratification corresponding closely to light attenuation and seafloor topography. Reefs have accreted relatively rapidly during the late-Holocene (1.8-3.0 mm y-1) with rates of vertical reef growth influenced by intrinsic shifts in coral assemblages associated with reef development. Indeed, these shallow-water reefs may have similar potential as refugia from large-scale disturbance as their deep-water (>30 m) "mesophotic" equivalents, and also provide a basis from which to model future trajectories of reef growth within nearshore areas.

KSC-2014-3126

NASA Image and Video Library

2014-07-03

CAPE CANAVERAL, Fla. – Former NASA astronaut Tom Jones, left, joins Andrea Farmer, senior public relations manager with Delaware North Parks and Resorts at NASA Kennedy Space Center Visitor Complex in Florida, for the grand opening of the Great Balls of Fire exhibit. Great Balls of Fire shares the story of the origins of our solar system, asteroids and comets and their possible impacts and risks. The 1,500-square-foot exhibit, located in the East Gallery of the IMAX theatre at the visitor complex, features several interactive displays, real meteorites and replica asteroid models. The exhibit is a production of The Space Science Institute's National Center for Interactive Learning. It is a traveling exhibition that also receives funding from NASA and the National Science Foundation. Photo credit: NASA/Daniel Casper

KSC-2014-3133

NASA Image and Video Library

2014-07-03

CAPE CANAVERAL, Fla. – Former NASA astronaut Tom Jones discusses the characteristics of asteroids and meteors with a young guest during the grand opening of the Great Balls of Fire exhibit at NASA’s Kennedy Space Center Visitor Complex in Florida. Great Balls of Fire shares the story of the origins of our solar system, asteroids and comets and their possible impacts and risks. The 1,500-square-foot exhibit, located in the East Gallery of the IMAX theatre at the visitor complex, features several interactive displays, real meteorites and replica asteroid models. The exhibit is a production of The Space Science Institute's National Center for Interactive Learning. It is a traveling exhibition that also receives funding from NASA and the National Science Foundation. Photo credit: NASA/Daniel Casper

KSC-2014-3127

NASA Image and Video Library

2014-07-03

CAPE CANAVERAL, Fla. – Therrin Protze, chief operating officer with Delaware North Parks and Resorts at NASA's Kennedy Space Center Visitor Complex in Florida, welcomes guests to the grand opening of the Great Balls of Fire exhibit. Great Balls of Fire shares the story of the origins of our solar system, asteroids and comets and their possible impacts and risks. The 1,500-square-foot exhibit, located in the East Gallery of the IMAX theatre at the visitor complex, features several interactive displays, real meteorites and replica asteroid models. The exhibit is a production of The Space Science Institute's National Center for Interactive Learning. It is a traveling exhibition that also receives funding from NASA and the National Science Foundation. Photo credit: NASA/Daniel Casper

KSC-2014-3132

NASA Image and Video Library

2014-07-03

CAPE CANAVERAL, Fla. – Former NASA astronaut Tom Jones discusses the characteristics of asteroids and meteors with a young guest during the grand opening of the Great Balls of Fire exhibit at NASA’s Kennedy Space Center Visitor Complex in Florida. Great Balls of Fire shares the story of the origins of our solar system, asteroids and comets and their possible impacts and risks. The 1,500-square-foot exhibit, located in the East Gallery of the IMAX theatre at the visitor complex, features several interactive displays, real meteorites and replica asteroid models. The exhibit is a production of The Space Science Institute's National Center for Interactive Learning. It is a traveling exhibition that also receives funding from NASA and the National Science Foundation. Photo credit: NASA/Daniel Casper

Rank-sparsity constrained atlas construction and phenotyping

NASA Astrophysics Data System (ADS)

Clark, D. P.; Badea, C. T.

2015-03-01

Atlas construction is of great interest in the medical imaging community as a tool to visually and quantitatively characterize anatomic variability within a population. Because such atlases generally exhibit superior data fidelity relative to the individual data sets from which they are constructed, they have also proven invaluable in numerous informatics applications such as automated segmentation and classification, regularization of individual-specific reconstructions from undersampled data, and for characterizing physiologically relevant functional metrics. Perhaps the most valuable role of an anatomic atlas is not to define what is "normal," but, in fact, to recognize what is "abnormal." Here, we propose and demonstrate a novel anatomic atlas construction strategy that simultaneously recovers the average anatomy and the deviation from average in a visually meaningful way. The proposed approach treats the problem of atlas construction within the context of robust principal component analysis (RPCA) in which the redundant portion of the data (i.e. the low rank atlas) is separated from the spatially and gradient sparse portion of the data unique to each individual (i.e. the sparse variation). In this paper, we demonstrate the application of RPCA to the Shepp-Logan phantom, including several forms of variability encountered with in vivo data: population variability, class variability, contrast variability, and individual variability. We then present preliminary results produced by applying the proposed approach to in vivo, murine cardiac micro-CT data acquired in a model of right ventricle hypertrophy induced by pulmonary arteriole hypertension.

Patterns in stream greenhouse gas dynamics from mountains to plains in northcentral Wyoming

NASA Astrophysics Data System (ADS)

Kuhn, C.; Bettigole, C.; Glick, H. B.; Seegmiller, L.; Oliver, C. D.; Raymond, P.

2017-09-01

Quantification of small stream contributions to global carbon cycling is key to understanding how freshwater systems transmit and transform carbon between terrestrial and atmospheric pools. To date, greenhouse gas emissions of carbon dioxide and methane from freshwaters, particularly in mountainous regions, remain poorly characterized due to a lack of direct field observations. Using a unique longitudinal approach, we conducted field surveys across two ecoregions (Middle Rockies and Great Plains) in the Clear Creek watershed, a subwatershed of Wyoming's Powder River Basin. We took direct measurements of stream gases using headspace sampling at 30 sites (8 June to 23 October). We observed the lowest and most variable concentrations in headwaters, which flow through a federally designated alpine wilderness area. By contrast, the Great Plains exhibited 1.45 and 4 times higher pCO2 and pCH4 concentrations and the relative contributions of methane increased downstream. Fluxes during snowmelt were 45% and 58% higher for CO2 and CH4 than during base flow but overall were lower than estimates for other systems. Variability for pCO2 was highest during late summer and in the uppermost sections of the headwaters. The high heterogeneity and common undersaturation observed through space and time, especially in the mountains, suggest that downscaled regional estimates may fail to capture variability in fluxes observed at these smaller scales. Based on these results, we strongly recommend higher resolution time series studies and increased scrutiny of systems at near equilibrium, inclusive of winter storage and ice-off events, to improve our understanding of the effects of seasonal dynamics on these processes.

Recent changes in county-level corn yield variability in the United States from observations and crop models

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

Leng, Guoyong

The United States is responsible for 35% and 60% of global corn supply and exports. Enhanced supply stability through a reduction in the year-to-year variability of US corn yield would greatly benefit global food security. Important in this regard is to understand how corn yield variability has evolved geographically in the history and how it relates to climatic and non-climatic factors. Results showed that year-to-year variation of US corn yield has decreased significantly during 1980-2010, mainly in Midwest Corn Belt, Nebraska and western arid regions. Despite the country-scale decreasing variability, corn yield variability exhibited an increasing trend in South Dakota,more » Texas and Southeast growing regions, indicating the importance of considering spatial scales in estimating yield variability. The observed pattern is partly reproduced by process-based crop models, simulating larger areas experiencing increasing variability and underestimating the magnitude of decreasing variability. And 3 out of 11 models even produced a differing sign of change from observations. Hence, statistical model which produces closer agreement with observations is used to explore the contribution of climatic and non-climatic factors to the changes in yield variability. It is found that climate variability dominate the change trends of corn yield variability in the Midwest Corn Belt, while the ability of climate variability in controlling yield variability is low in southeastern and western arid regions. Irrigation has largely reduced the corn yield variability in regions (e.g. Nebraska) where separate estimates of irrigated and rain-fed corn yield exist, demonstrating the importance of non-climatic factors in governing the changes in corn yield variability. The results highlight the distinct spatial patterns of corn yield variability change as well as its influencing factors at the county scale. I also caution the use of process-based crop models, which have substantially underestimated the change trend of corn yield variability, in projecting its future changes.« less

Essential-Oil Variability in a Collection of Ocimum basilicum L. (Basil) Cultivars.

PubMed

Maggio, Antonella; Roscigno, Graziana; Bruno, Maurizio; De Falco, Enrica; Senatore, Felice

2016-10-01

Ocimum basilicum L. (Lamiaceae) is an aromatic plant of great tradition in the Mediterranean area. Its economic importance is growing up determining an expansion of cultivation. This paper evaluated the morphological traits, the chemical profiles, and antibacterial activity of 21 cultivars of basil belonging to 'Genovese', 'Napoletano', and 'Purple basil' types. The cultivars were characterized by different growth rate and morphological traits. The chemical composition of the oils analyzed by GC and GC/MS analysis, supported by the PCA analysis, underlined the strong influence of chemotype. It is noteworthy that estragole, never present in Genovese and purple basil types, occurred in Napoletano type. The high presence of eugenol, methyl eugenol, and linalool in the majority of cultivars, belonging both to Genovese and to Napoletano types was registered. Of great interest resulted the composition of the purple basil 'Opal'. All the samples tested exhibited similar antibiotic profiles with moderate antibacterial activity. The results enhanced the importance of determination of essential-oil profile in the selection of cultivars characterized by diverse morphological traits and are useful for different purposes. © 2016 Wiley-VHCA AG, Zürich.

KSC-2014-3137

NASA Image and Video Library

2014-07-03

CAPE CANAVERAL, Fla. – The grand opening of the new Great Balls of Fire exhibit was held at NASA’s Kennedy Space Center Visitor Complex in Florida. The grand opening featured remarks by former NASA astronaut Tom Jones, and Therrin Protze, chief operating officer at Delaware North Parks and Resorts at the visitor complex. Informational displays about future NASA exploration missions are featured along the wall of the new exhibit. Great Balls of Fire shares the story of the origins of our solar system, asteroids and comets and their possible impacts and risks. The 1,500-square-foot exhibit, located in the East Gallery of the IMAX theatre at the visitor complex, features several interactive displays, real meteorites and replica asteroid models. The exhibit is a production of The Space Science Institute's National Center for Interactive Learning. It is a traveling exhibition that also receives funding from NASA and the National Science Foundation. Photo credit: NASA/Daniel Casper

KSC-2014-3128

NASA Image and Video Library

2014-07-03

CAPE CANAVERAL, Fla. – Therrin Protze, chief operating officer with Delaware North Parks and Resorts at NASA's Kennedy Space Center Visitor Complex in Florida, welcomes guests to the grand opening of the Great Balls of Fire exhibit. To his left is former NASA astronaut Tom Jones. Great Balls of Fire shares the story of the origins of our solar system, asteroids and comets and their possible impacts and risks. The 1,500-square-foot exhibit, located in the East Gallery of the IMAX theatre at the visitor complex, features several interactive displays, real meteorites and replica asteroid models. The exhibit is a production of The Space Science Institute's National Center for Interactive Learning. It is a traveling exhibition that also receives funding from NASA and the National Science Foundation. Photo credit: NASA/Daniel Casper

KSC-2014-3125

NASA Image and Video Library

2014-07-03

CAPE CANAVERAL, Fla. – Former NASA astronaut Tom Jones, left, joins Andrea Farmer, senior public relations manager, and Therrin Protze, chief operating officer, both with Delaware North Parks and Resorts at NASA's Kennedy Space Center Visitor Complex in Florida, for the grand opening of the Great Balls of Fire exhibit. Great Balls of Fire shares the story of the origins of our solar system, asteroids and comets and their possible impacts and risks. The 1,500-square-foot exhibit, located in the East Gallery of the IMAX theatre at the visitor complex, features several interactive displays, real meteorites and replica asteroid models. The exhibit is a production of The Space Science Institute's National Center for Interactive Learning. It is a traveling exhibition that also receives funding from NASA and the National Science Foundation. Photo credit: NASA/Daniel Casper

Structural styles of the Guess Creek fault block beneath the Great Smoky thrust sheet, Blount County, Tennessee

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

Carter, M.W.; Davidson, G.L.; Heller, J.A.

1993-03-01

A road cut along US 321 N, approximately 1 km NW of Walland, TN, exposes a previously unexposed complexly deformed section of Middle Ordovician clastic wedge [Chickamauga Group, Sevier Shale] sedimentary rocks. It provides an excellent opportunity to analyze both the lithologic assemblages and complex folding and faulting beneath the Great Smoky thrust sheet. Arkosic quartzite of the Lower Cambrian Cochran Conglomerate [Chilhowee Group], has been thrust over weaker Sevier Shale in the hanging wall of the Guess Creek fault. Regionally, the Great Smoky fault separates metamorphosed Precambrian to Lower Cambrian clastic shelf, slope, and rift facies rocks of themore » western Blue Ridge from Cambro-Ordovician carbonate shelf and orogenic wedge deposits of the foreland fold and thrust belt. West of the Great Smoky fault, the Guess Creek fault has been interpreted to floor duplexed Cambro-Ordovician rocks exposed in windows beneath the Great Smoky thrust sheet in the vicinity of the Great Smoky Mountains National Park. The Sevier Shale here consists of variably cleaved shale, siltstone, sandstone, and conglomerate. It exhibits a variety of fold styles throughout the exposure, ranging from predominantly noncylindrical tight folds to broad, open structures. A weak axial-planar pencil cleavage is developed in the Middle Ordovician shale and siltstone, along with a secondary cleavage that transects the axial surfaces of the folds. Minor thrust faults within the Sevier Shale appear to have formed by propagation through tightened fold hinges or bedding-parallel slip. The fold pattern observed in the roadcut appears to be partly the result of movement along a tear fault that broke both the hanging wall and footwall of the Great Smoky thrust sheet after emplacement. Slickenline orientations along minor thrust surfaces in the Cochran Conglomerate indicate eastward-directed, oblique-slip movement of the tear fault.« less

Environmental drivers and reproductive consequences of variation in the diet of a marine predator

NASA Astrophysics Data System (ADS)

Gladics, Amanda J.; Suryan, Robert M.; Parrish, Julia K.; Horton, Cheryl A.; Daly, Elizabeth A.; Peterson, William T.

2015-06-01

Ocean conditions can greatly impact lower trophic level prey assemblages in marine ecosystems, with effects of ocean state propagating to higher trophic levels. In many regions throughout their range, common murre (Uria aalge) exhibit narrow dietary breadth in feeding chicks and therefore are vulnerable to recruitment failures of dominant prey species during the breeding season. Contrastingly, common murres nesting in the northern California Current off Oregon, exhibit high species diversity and variability in dominant prey consumed. We studied the diets of common murres over 10 years between 1998 and 2011, a period in which the northern California Current experienced dramatic interannual variability in ocean conditions. Likewise, murre diets off Oregon varied considerably. Interannual variation in murre chick diets was influenced by environmental drivers occurring before and during the breeding season, and at both basin and local scales. While clupeids (likely Pacific herring, Clupea pallasii) were an important diet component throughout the study period, in some years murre diets were dominated by Pacific sand lance (Ammodytes hexapterus) and in other years by osmerids (likely whitebait smelt, Allosmerus elongatus and surf smelt, Hypomesus pretiosus). Years in which the Pacific Decadal Oscillation and local sea surface temperatures were higher during summer also showed elevated levels of clupeids in murre diets, while years with higher North Pacific Gyre Oscillation index values and greater local winter ichthyoplankton biomass had fewer clupeids and more sand lance or smelts. Years with higher values of the Northern Oscillation Index during summer and an earlier spring transition showed higher proportion of smelts in the diets. Nesting phenology and reproductive success were negatively correlated with gradients in sand lance and clupeids, respectively, reflecting demographic consequences of environmental variability mediated through bottom-up food web dynamics.

Visualizing ferromagnetic domains in undoped and Fe-doped Sr4Ru3O10

NASA Astrophysics Data System (ADS)

Sass, Paul; Wu, Weida; Mao, Zhiqiang; Li, Peigang

Transition-metal oxides have proven to be a great source of interesting phenomena and new quantum phases of matter with high potential for developing exciting technologies. A remarkable sub-class of these materials with layer dependent properties is the ruthenium perovskites of the Ruddlesden-Popper series, specifically Srn + 1RunO3 n + 1 , exhibiting a range of behavior from ferromagnetism and metamagnetic quantum criticality to p-wave superconductivity. The triple layered oxide Sr4Ru3O10 exhibits coexistence of ferro- (TC < 105 K) and meta- (TM < 50 K) magnetism with strong anisotropy. Despite many studies on bulk magnetic properties of this material, the microscopic nature of the magnetic phase is still unclear. What is lacking is the real space imaging of magnetic domains. To this end, we report our variable temperature magnetic force microscopy studies on floating-zone grown undoped and Fe-doped Sr4Ru3O10 single crystals. Various stripe and branch-like domain patterns were observed below This work is supported by DOE BES under award DE-SC0008147.

Fluorene-Based Conjugated Microporous Polymers: Preparation and Chemical Sensing Application.

PubMed

Zhang, Qiujing; Yu, Sen; Wang, Qian; Xiao, Qin; Yue, Yong; Ren, Shijie

2017-12-01

Conjugated microporous polymers (CMPs) with strong fluorescence are great candidates for optoelectronic applications such as photocatalysis and chemical sensing. A series of novel fluorene-based conjugated microporous polymers (FCMPs) with different electronic structures are prepared by Yamamoto coupling reactions using rationally designed monomers. The FCMPs show a high degree of microporosity, decent specific surface areas, and variable fluorescence. FCMP3, which possesses a triazine knot in the network, exhibits the highest specific surface area of 489 m 2 g -1 , the largest pore volume of 0.30 cm 3 g -1 , and the highest solid-state photoluminescence quantum yield of 11.46%. Chemical sensing performance of FCMPs is studied using a range of nitroaromatic compounds as the analytes. Among the FCMPs, FCMP3 exhibits the highest Stern-Volmer constants of 2541, 4708, and 5241 m -1 for the detection of nitrobenzene, 4-nitrotoluene, 2,4-dinitrotoluene, respectively, which are comparable to the detecting efficiency of the state-of-the-art CMP-based sensing agents. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Comets, Asteroids and Rubble Piles: not just debris

NASA Astrophysics Data System (ADS)

Harold, J. B.; Dusenbery, P.

2010-12-01

The National Center for Interactive Learning at the Space Science Institute (NCIL @ SSI) is developing a variety of asteroids related education activities as part of several E/PO projects, including Finding NEO (funded through NSF and NASA SMD); Great Balls of Fire! (funded through NSF); and a partnership with the WISE (Wide-field Infrared Survey Explorer) mission. These activities range from a web site to traveling exhibits in three different sizes. The Killer Asteroids web site (www.killerasteroids.org) includes background information on comets and asteroids as well as a number of interactive activities and games. These include a game that compares the risk of death from an asteroid impact to other hazards; a game and video vignettes on the role of backyard astronomers in light curve research; a physics-based asteroid deflection game; and a Google Earth -based "drop a rock on your house" activity. In addition, the project is developing a small, portable exhibit suitable for use in libraries or visitors centers. Great Balls of Fire! includes two separate traveling exhibitions: a 3000 square foot exhibition for science centers, and a 500 square foot version for smaller venues. Both will begin national tours in the summer of 2011. The Great Balls of Fire! exhibit program includes a free Education Program for docents and educators, and an Outreach Program to amateur astronomers around the country through the Astronomical Society of the Pacific’s (ASP) Astronomy from the Ground Up program. The project will facilitate partnerships between host venues and local astronomy clubs that can interact with the public using a toolkit of activities developed by ASP. Great Balls of Fire! Represents a collaboration between scientists, educators, exhibit designers, graphic artists, evaluators, education researchers, and three teams of middle school students who acted as advisors. The project’s exhibit design firm is Jeff Kennedy Associates Inc. We will present a summary of the different components of these projects and how different audiences can take advantage of them, from science centers and libraries that can host the exhibits, to home and classroom use through the web site.

KSC-2014-3131

NASA Image and Video Library

2014-07-03

CAPE CANAVERAL, Fla. – Lights flickered and balloons fell as former NASA astronaut Tom Jones, left, and Therrin Protze, chief operating officer of Delaware North Parks and Resorts at NASA’s Kennedy Space Center Visitor Complex in Florida, welcomed guests to the grand opening of the Great Balls of Fire exhibit at the visitor complex. Great Balls of Fire shares the story of the origins of our solar system, asteroids and comets and their possible impacts and risks. The 1,500-square-foot exhibit, located in the East Gallery of the IMAX theatre at the visitor complex, features several interactive displays, real meteorites and replica asteroid models. The exhibit is a production of The Space Science Institute's National Center for Interactive Learning. It is a traveling exhibition that also receives funding from NASA and the National Science Foundation. Photo credit: NASA/Daniel Casper

KSC-2014-3136

NASA Image and Video Library

2014-07-03

CAPE CANAVERAL, Fla. – The grand opening of the new Great Balls of Fire exhibit was held at NASA’s Kennedy Space Center Visitor Complex in Florida. The grand opening featured remarks by former NASA astronaut Tom Jones, and Therrin Protze, chief operating officer at Delaware North Parks and Resorts at the visitor complex. Great Balls of Fire shares the story of the origins of our solar system, asteroids and comets and their possible impacts and risks. The 1,500-square-foot exhibit, located in the East Gallery of the IMAX theatre at the visitor complex, features several interactive displays, real meteorites and replica asteroid models. The exhibit is a production of The Space Science Institute's National Center for Interactive Learning. It is a traveling exhibition that also receives funding from NASA and the National Science Foundation. Photo credit: NASA/Daniel Casper

KSC-2014-3134

NASA Image and Video Library

2014-07-03

CAPE CANAVERAL, Fla. – A real asteroid is on display at the new Great Balls of Fire exhibit at NASA’s Kennedy Space Center Visitor Complex in Florida. The grand opening of the new attraction featured remarks by former NASA astronaut Tom Jones, and Therrin Protze, chief operating officer at Delaware North Parks and Resorts at the visitor complex. Great Balls of Fire shares the story of the origins of our solar system, asteroids and comets and their possible impacts and risks. The 1,500-square-foot exhibit, located in the East Gallery of the IMAX theatre at the visitor complex, features several interactive displays, real meteorites and replica asteroid models. The exhibit is a production of The Space Science Institute's National Center for Interactive Learning. It is a traveling exhibition that also receives funding from NASA and the National Science Foundation. Photo credit: NASA/Daniel Casper

Demographic and social variables associated with psychiatric and school-related indicators for Asian/Pacific-Islander adolescents.

PubMed

Hishinuma, Earl S; Johnson, Ronald C; Carlton, Barry S; Andrade, Naleen N; Nishimura, Stephanie T; Goebert, Deborah A; Yuen, Noelle Y C; Wegner, Eldon L; Makini, George K; Nahulu, Linda B; Else, Iwalani R N; Chang, Janice Y

2004-12-01

Factors associated with Asian/Pacific-Islander adolescent adjustment is a greatly neglected research area. The purpose of the present study was to investigate the relation between demographic, social and adjustment measures based on a large-scale investigation of Asian/Pacific-Islander youths. A total of 2577 adolescents were surveyed across 4 public schools in Hawai'i during the 1992--1993 school year. Three social variables (number of relatives frequently seen, family support and friends' support) exhibited statistically significant but low correlations. Family support had the highest negative association with the four psychiatric symptoms (depression, anxiety, aggression, substance use). Friends' support was inconsistently associated with the adjustment measures, and the number of relatives frequently seen resulted in negligible effects. In contrast, demographic variables, especially ethnicity, played a much greater role in the association with the four school-related measures (grade-point average, absences, suspensions, conduct infractions). For Asian/Pacific-Islander youths, the quality of the social supports, including family relations, may be particularly important in the adolescents' adjustment. When examining school-related outcomes, demographic variables, with particular emphases on ethnicity and culture, must be considered. When developing and implementing prevention and intervention services and programs, consideration of family and ethnic-cultural influences should be taken into account, with further research needed in several related domains: other SES influences, life stressors, migration-generational effects, ethnic identity, self-concept indicators and socio-political aspects.

Use of WONCA global standards to evaluate family medicine postgraduate education for curriculum development and review in Nepal and Myanmar.

PubMed

Gibson, Christine; Ladak, Farah; Shrestha, Ashis; Yadav, Bharat; Thu, Kyaw; Aye, Tin

2016-09-01

Family medicine is an integral part of primary care within health systems. Globally, training programmes exhibit a great degree of variability in content and skill acquisition. While this may in part reflect the needs of a given setting, there exists standard criteria that all family medicine programmes should consider core activities. WONCA has provided an open-access list of standards that their expert community considers essential for family medicine (GP) post-graduate training. Evaluation of developing or existing training programmes using these standards can provide insight into the degree of variability, gaps within programmes and equally as important, gaps within recommendations. In collaboration with the host institution, two family medicine programmes in Nepal and Myanmar were evaluated based on WONCA global standards. The results of the evaluation demonstrated that such a process can allow for critical review of curriculum in various stages of development and evaluation. The implications of reviewing training programmes according to WONCA standards can lead to enhanced training world-wide and standardisation of training for post-graduate family medicine.

Content of gamma-oryzanol and composition of steryl ferulates in brown rice (Oryza sativa L.) of European origin.

PubMed

Miller, Andreas; Engel, Karl-Heinz

2006-10-18

The content of gamma-oryzanol and the composition of steryl ferulates were determined in brown rice of European origin using on-line coupled liquid chromatography-gas chromatography (LC-GC). Analysis of 30 brown rice samples of various cultivars, grown at different sites and in different seasons, revealed the gamma-oryzanol content to range from 26 to 63 mg/100 g. Cycloartenyl ferulate and 24-methylenecycloartanyl ferulate were the major components of gamma-oryzanol followed by campesteryl ferulate, campestanyl ferulate, and beta-sitosteryl ferulate. The proportions of individual steryl ferulates exhibited enormous variability. However, irrespectively of the great variations observed for single steryl ferulates, the proportions of the sum of 4,4'-dimethylsteryl ferulates (cycloartenyl ferulate, 24-methylenecycloartanyl ferulate) and the sum of 4-desmethylsteryl ferulates (campesteryl ferulate, campestanyl ferulate, and beta-sitosteryl ferulate) were rather constant. The significant natural variability observed for gamma-oryzanol content and composition of steryl ferulates were shown to be influenced by environmental conditions but not by the degree of maturity of rice grains.

Ultrasensitive direct impedimetric immunosensor for detection of serum HER2.

PubMed

Sharma, Shikha; Zapatero-Rodríguez, Julia; Saxena, Rahul; O'Kennedy, Richard; Srivastava, Sudha

2018-05-30

Assesment of human epidermal growth factor receptor 2 status is a key factor prompting definitive treatment decisions that help in reducing mortality rates associated with breast cancer. In this article, highly sensitive and low-cost impedimetric immunosensor using single-chain fragment variable antibody fragments was developed for quantitative detection of human epidermal growth factor receptor 2 from serum employing gold nanoparticle-modified disposable screen-printed carbon electrodes. The gold nanoparticles facilitate fast electron transfer and offer a biocompatible surface for immobilization of small antibody fragments in an oriented manner, resulting in improved antigen binding efficiency. The single-chain fragment variable antibody fragment-modified screen printed immunosensor exhibits wide dynamic range of 0.01-100 ng mL -1 and detection limit of 0.01 ng mL -1 . The advantages offered by this platform in terms of high sensitivity, broad dynamic range and low-cost demonstrates great potential for improved monitoring of human epidermal growth factor receptor 2 levels for the management of breast and other cancers. Copyright © 2018 Elsevier B.V. All rights reserved.

Space Research Institute (IKI) Exhibition as an Educational Project

NASA Astrophysics Data System (ADS)

Sadovski, Andrei; Antonenko, Elena

2016-07-01

The Exhibition "Space Science: Part and Future" in Space Research Institute (IKI) was opened in 2007 in commemoration of the 50th anniversary of the first man-made satellite launch. It covers the latest and the most important findings in space research, shows instruments which are used in space exploration, and presents past, current, and future Russian science missions. Prototypes of space instruments developed by Russian specialists and mockups of spacecraft and spaceships flown to space are displayed, together with information posters, describing space missions, their purposes and results. The Exhibition takes a great part in school space education. Its stuff actively works with schoolchildren, undergraduate students and also makes a great contribution in popularization of space researches. Moreover the possibility to learn about scientific space researches first-hand is priceless. We describe the main parts of the Exhibition and forms of it work and also describe the collaboration with other museums and educational organizations.

KSC-2014-3130

NASA Image and Video Library

2014-07-03

CAPE CANAVERAL, Fla. – Former NASA astronaut Tom Jones, left, presses the button on a simulated model of an asteroid to mark the grand opening of the new Great Balls of Fire exhibit at NASA’s Kennedy Space Center Visitor Complex in Florida. To his right is Therrin Protze, chief operating officer with Delaware North Parks and Resorts at the visitor complex. Great Balls of Fire shares the story of the origins of our solar system, asteroids and comets and their possible impacts and risks. The 1,500-square-foot exhibit, located in the East Gallery of the IMAX theatre at the visitor complex, features several interactive displays, real meteorites and replica asteroid models. The exhibit is a production of The Space Science Institute's National Center for Interactive Learning. It is a traveling exhibition that also receives funding from NASA and the National Science Foundation. Photo credit: NASA/Daniel Casper

KSC-2014-3135

NASA Image and Video Library

2014-07-03

CAPE CANAVERAL, Fla. – Samples of Earth rocks and real meteorites are featured in an interactive display at the new Great Balls of Fire exhibit at NASA’s Kennedy Space Center Visitor Complex in Florida. The grand opening featured remarks by former NASA astronaut Tom Jones, and Therrin Protze, chief operating officer at Delaware North Parks and Resorts at the visitor complex. Great Balls of Fire shares the story of the origins of our solar system, asteroids and comets and their possible impacts and risks. The 1,500-square-foot exhibit, located in the East Gallery of the IMAX theatre at the visitor complex, features several interactive displays, real meteorites and replica asteroid models. The exhibit is a production of The Space Science Institute's National Center for Interactive Learning. It is a traveling exhibition that also receives funding from NASA and the National Science Foundation. Photo credit: NASA/Daniel Casper

Structure, transport, and vertical coherence of the Gulf Stream from the Straits of Florida to the Southeast Newfoundland Ridge

NASA Astrophysics Data System (ADS)

Meinen, Christopher S.; Luther, Douglas S.

2016-06-01

Data from three independent and extensive field programs in the Straits of Florida, the Mid-Atlantic Bight, and near the Southeast Newfoundland Ridge are reanalyzed and compared with results from other historical studies to highlight the downstream evolution of several characteristics of the Gulf Stream's mean flow and variability. The three locations represent distinct dynamical regimes: a tightly confined jet in a channel; a freely meandering jet; and a topographically controlled jet on a boundary. Despite these differing dynamical regimes, the Gulf Stream in these areas exhibits many similarities. There are also anticipated and important differences, such as the loss of the warm core of the current by 42°N and the decrease in the cross-frontal gradient of potential vorticity as the current flows northward. As the Gulf Stream evolves it undergoes major changes in transport, both in magnitude and structure. The rate of inflow up to 60°W and outflow thereafter are generally uniform, but do exhibit some remarkable short-scale variations. As the Gulf Stream flows northward the vertical coherence of the flow changes, with the Florida Current and North Atlantic Current segments of the Gulf Stream exhibiting distinct upper and deep flows that are incoherent, while in the Mid-Atlantic Bight the Gulf Stream exhibits flows in three layers each of which tends to be incoherent with the other layers at most periods. These coherence characteristics are exhibited in both Eulerian and stream coordinates. The observed lack of vertical coherence indicates that great caution must be exercised in interpreting proxies for Gulf Stream structure and flow from vertically-limited or remote observations.

Structure, transport, and vertical coherence of the Gulf Stream from the Straits of Florida to the Southeast Newfoundland Ridge

NASA Astrophysics Data System (ADS)

Meinen, Christopher S.; Luther, Douglas S.

2016-05-01

Data from three independent and extensive field programs in the Straits of Florida, the Mid-Atlantic Bight, and near the Southeast Newfoundland Ridge are reanalyzed and compared with results from other historical studies to highlight the downstream evolution of several characteristics of the Gulf Stream's mean flow and variability. The three locations represent distinct dynamical regimes: a tightly confined jet in a channel; a freely meandering jet; and a topographically controlled jet on a boundary. Despite these differing dynamical regimes, the Gulf Stream in these areas exhibits many similarities. There are also anticipated and important differences, such as the loss of the warm core of the current by 42°N and the decrease in the cross-frontal gradient of potential vorticity as the current flows northward. As the Gulf Stream evolves it undergoes major changes in transport, both in magnitude and structure. The rate of inflow up to 60°W and outflow thereafter are generally uniform, but do exhibit some remarkable short-scale variations. As the Gulf Stream flows northward the vertical coherence of the flow changes, with the Florida Current and North Atlantic Current segments of the Gulf Stream exhibiting distinct upper and deep flows that are incoherent, while in the Mid-Atlantic Bight the Gulf Stream exhibits flows in three layers each of which tends to be incoherent with the other layers at most periods. These coherence characteristics are exhibited in both Eulerian and stream coordinates. The observed lack of vertical coherence indicates that great caution must be exercised in interpreting proxies for Gulf Stream structure and flow from vertically-limited or remote observations.

We Practice What We Preach: A Local History of a Community-Based, Student/Faculty Art Exhibition (2002-09)

ERIC Educational Resources Information Center

Ashworth, Elizabeth Auger; Jarvis, Daniel H.

2009-01-01

Student-organized exhibitions hold the potential to greatly enhance the visual arts school curriculum. Student art exhibition events can address socio-economic issues, function as part of integrated or interdisciplinary projects, and even unite students from different continents using today's high-speed Internet connectivity. Although there is…

Long-term hydrometeorological trends in the Midwest region based on a century long gridded hydrometeorological dataset and simulations from a macro-scale hydrology model

NASA Astrophysics Data System (ADS)

Chiu, C. M.; Hamlet, A. F.

2014-12-01

Climate change is likely to impact the Great Lakes region and Midwest region via changes in Great Lakes water levels, agricultural impacts, river flooding, urban stormwater impacts, drought, water temperature, and impacts to terrestrial and aquatic ecosystems. Self-consistent and temporally homogeneous long-term data sets of precipitation and temperature over the entire Great Lakes region and Midwest regions are needed to provide inputs to hydrologic models, assess historical trends in hydroclimatic variables, and downscale global and regional-scale climate models. To support these needs a new hybrid gridded meteorological forcing dataset at 1/16 degree resolution based on data from co-op station records, the U. S Historical Climatology Network (HCN) , the Historical Canadian Climate Database (HCCD), and Precipitation Regression on Independent Slopes Method (PRISM) has been assembled over the Great Lakes and Midwest region from 1915-2012 at daily time step. These data were then used as inputs to the macro-scale Variable Infiltration Capacity (VIC) hydrology model, implemented over the Midwest and Great Lakes region at 1/16 degree resolution, to produce simulated hydrologic variables that are amenable to long-term trend analysis. Trends in precipitation and temperature from the new meteorological driving data sets, as well as simulated hydrometeorological variables such as snowpack, soil moisture, runoff, and evaporation over the 20th century are presented and discussed.

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

Xian, Fenglin; Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra 2601; Ye, Jiandong, E-mail: yejd@nju.edu.cn

In this work, anion alloying is engineered in ZnON nanocrystalline films, and the resultant evolution of the structural transition, subgap states, and carrier transport is investigated. A broad distribution of sub-gap states above the valence band maximum is introduced by nitrogen due to the hybridization of N 2p and O 2p orbitals. The phase transition from partially amorphous states to full crystallinity occurs above a characteristic growth temperature of 100 °C, and the localized states are suppressed greatly due to the reduction of nitrogen composition. The electronic properties are dominated by grain boundary scattering and electron transport across boundary barriers throughmore » thermal activation at band edge states at high temperatures. The conductivity below 130 K exhibits a weak temperature dependence, which is a signature of variable-range hopping conduction between localized states introduced by nitrogen incorporation.« less

The Summertime Warming Trends in Surface Water Temperature of the Great Lakes

NASA Astrophysics Data System (ADS)

Sugiyama, N.; Kravtsov, S.; Roebber, P.

2014-12-01

Over the past 30 years, the Laurentian Great Lakes have exhibited summertime warming trends in surface water temperature which were greater than those in surface air temperature of the surrounding land, by as much as an order of magnitude over some of the regions. For the years 1995-2012, Lake Superior exhibited the most dramatic warming trend in July-mean temperature, of 0.27±0.15 deg. C yr-1, based on the NOAA's GLSEA satellite observations. Shallower lakes, such as Lake Erie, exhibited smaller warming trends. In addition, within each lake, the warming was also the greatest in the regions of larger water depth; for example, some regions of Lake Superior deeper than 200m exhibited surface-water July-mean warming trends which exceeded 0.3 deg. C yr-1. We used a three-column lake model based on the one developed by Hostetler and Barnstein (1990) coupled with a two-layer atmospheric energy balance model to explore the physics behind these warming trends. We found that, as suggested by Austin and Colman (2007), the ice-albedo feedback plays an important role in amplifying the overlake warming trends. Our particular emphasis was on the question of whether the ice-albedo feedback alone is enough to account for lacustrine amplification of surface warming observed over the Great Lakes region. We found that the answer to this question depends on a number of model parameters, including the diffusion and light attenuation coefficients, which greatly affect the model's skill in reproducing the observed ice coverage of the deep lakes.

Perceptions of variability in facial emotion influence beliefs about the stability of psychological characteristics.

PubMed

Weisbuch, Max; Grunberg, Rebecca L; Slepian, Michael L; Ambady, Nalini

2016-10-01

Beliefs about the malleability versus stability of traits (incremental vs. entity lay theories) have a profound impact on social cognition and self-regulation, shaping phenomena that range from the fundamental attribution error and group-based stereotyping to academic motivation and achievement. Less is known about the causes than the effects of these lay theories, and in the current work the authors examine the perception of facial emotion as a causal influence on lay theories. Specifically, they hypothesized that (a) within-person variability in facial emotion signals within-person variability in traits and (b) social environments replete with within-person variability in facial emotion encourage perceivers to endorse incremental lay theories. Consistent with Hypothesis 1, Study 1 participants were more likely to attribute dynamic (vs. stable) traits to a person who exhibited several different facial emotions than to a person who exhibited a single facial emotion across multiple images. Hypothesis 2 suggests that social environments support incremental lay theories to the extent that they include many people who exhibit within-person variability in facial emotion. Consistent with Hypothesis 2, participants in Studies 2-4 were more likely to endorse incremental theories of personality, intelligence, and morality after exposure to multiple individuals exhibiting within-person variability in facial emotion than after exposure to multiple individuals exhibiting a single emotion several times. Perceptions of within-person variability in facial emotion-rather than perceptions of simple diversity in facial emotion-were responsible for these effects. Discussion focuses on how social ecologies shape lay theories. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Fear of Public Speaking: Perception of College Students and Correlates.

PubMed

Ferreira Marinho, Anna Carolina; Mesquita de Medeiros, Adriane; Côrtes Gama, Ana Cristina; Caldas Teixeira, Letícia

2017-01-01

The aims of the study were to determine the prevalence of fear of public speaking among college students and to assess its association with sociodemographic variables and those related to the voice and oral communication. A cross-sectional descriptive and analytic study was conducted with 1135 undergraduates aged 17-58 years. The assessment instruments were (1) a questionnaire addressing the variables sex, age, field of undergraduate study, voice, and frequency of exposure to public speaking, and (2) the Self-statements During Public Speaking Scale (SSPS), which includes variables implicated in specific domains of public speaking. A descriptive analysis was performed of the variables as well as uni- and multivariate logistic regressions to examine their association with fear of public speaking. The level of significance was set at 5%. In all, 63.9% of the college students reported fear of public speaking. As many as 89.3% of the students would like their undergraduate program to include classes to improve public speaking. Being female, having infrequent participation as speakers in groups, and perceiving their voice as high-pitched or too soft increase the odds of exhibiting fear of public speaking compared with students without those features. A great number of undergraduates report fear of public speaking. This fear is more prevalent among women, students who participate in few activities involving speaking to groups of people, and those who have a self-perception of their voice as high-pitched or too soft. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Multi-scale responses of vegetation to removal of horse grazing from Great Basin (USA) mountain ranges

USGS Publications Warehouse

Beever, E.A.; Tausch, R.J.; Thogmartin, W.E.

2008-01-01

Although free-roaming equids occur on all of the world's continents except Antarctica, very few studies (and none in the Great Basin, USA) have either investigated their grazing effects on vegetation at more than one spatial scale or compared characteristics of areas from which grazing has been removed to those of currently grazed areas. We compared characteristics of vegetation at 19 sites in nine mountain ranges of the western Great Basin; sites were either grazed by feral horses (Equus caballus) or had had horses removed for the last 10-14 years. We selected horse-occupied and horse-removed sites with similar aspect, slope, fire history, grazing pressure by cattle (minimal to none), and dominant vegetation (Artemisia tridentata). During 1997 and 1998, line-intercept transects randomly located within sites revealed that horse-removed sites exhibited 1.1-1.9 times greater shrub cover, 1.2-1.5 times greater total plant cover, 2-12 species greater plant species richness, and 1.9-2.9 times greater cover and 1.1-2.4 times greater frequency of native grasses than did horse-occupied sites. In contrast, sites with horses tended to have more grazing-resistant forbs and exotic plants. Direction and magnitude of landscape-scale results were corroborated by smaller-scale comparisons within horse-occupied sites of horse-trail transects and (randomly located) transects that characterized overall site conditions. Information-theoretic analyses that incorporated various subsets of abiotic variables suggested that presence of horses was generally a strong determinant of those vegetation-related variables that differed significantly between treatments, especially frequency and cover of grasses, but also species richness and shrub cover and frequency. In contrast, abiotic variables such as precipitation, site elevation, and soil erodibility best predicted characteristics such as forb cover, shrub frequency, and continuity of the shrub canopy. We found species richness of plants monotonically decreased across sites as grazing disturbance increased, suggesting that either the bell-shaped diversity-disturbance curve of the intermediate-disturbance hypothesis does not apply in this system or that most sites are already all on the greater-disturbance slope of the curve. In our study, numerous vegetation properties of less-grazed areas and sites differed notably from horse-grazed sites at local and landscape scales during a wetter and an average-precipitation year. ?? 2007 Springer Science+Business Media B.V.

Factors related to northern goshawk landscape use in the western Great Lakes region

USGS Publications Warehouse

Bruggeman, Jason E.; Andersen, David E.; Woodford, James E.

2014-01-01

Northern Goshawks (Accipiter gentilis) are a species of special conservation concern in the western Great Lakes bioregion and elsewhere in North America, and exhibit landscape-scale spatial use patterns. However, little information exists about Northern Goshawk habitat relations at broad spatial extents, as most existing published information comes from a few locations of relatively small spatial extent and, in some cases, short durations. We used an information-theoretic approach to evaluate competing hypotheses regarding factors (forest canopy cover, successional stage, and heights of the canopy top and base) related to odds of Northern Goshawk landscape use throughout the western Great Lakes bioregion based on an occupancy survey completed in 2008 (Bruggeman et al. 2011). We also combined these data with historical data of Northern Goshawk nest locations in the bioregion from 1979–2006 to evaluate the same competing hypotheses to elucidate long-term trends in use. The odds of Northern Goshawk use in 2008, and from 1979–2008, were positively correlated with average percent canopy cover. In the best-approximating models developed using 1979–2008 data, the odds of landscape use were positively correlated with the percentages of the landscape having canopy heights between 10 m and 25 m, and 25 m and 50 m, and the amount of variability in canopy base height. Also, the odds of landscape use were negatively correlated with the average height at the canopy base. Our results suggest multiple habitat factors were related to Northern Goshawk landscape-scale habitat use, similar to habitat use described at smaller spatial scales in the western Great Lakes bioregion and in western North America and Europe.

Climate and climate variability of the wind power resources in the Great Lakes region of the United States

Treesearch

X. Li; S. Zhong; X. Bian; W.E. Heilman

2010-01-01

The climate and climate variability of low-level winds over the Great Lakes region of the United States is examined using 30 year (1979-2008) wind records from the recently released North American Regional Reanalysis (NARR), a three-dimensional, high-spatial and temporal resolution, and dynamically consistent climate data set. The analyses focus on spatial distribution...

Comparative and Familial Analysis of Handedness in Great Apes

ERIC Educational Resources Information Center

Hopkins, William D.

2006-01-01

Historically, population-level handedness has been considered a hallmark of human evolution. Whether nonhuman primates exhibit population-level handedness remains a topic of considerable debate. This paper summarizes published data on handedness in great apes. Comparative analysis indicated that chimpanzees and bonobos show population-level right…

A comparative quantitative analysis of cytoarchitecture and minicolumnar organization in Broca's area in humans and great apes.

PubMed

Schenker, Natalie M; Buxhoeveden, Daniel P; Blackmon, William L; Amunts, Katrin; Zilles, Karl; Semendeferi, Katerina

2008-09-01

Broca's area was identified in the inferior frontal gyrus of chimpanzee, bonobo, gorilla, and orangutan brains through direct cytoarchitectonic comparison with human brains. Across species, Broca's area comprises Brodmann's areas 44 and 45. We found that these areas exhibited similar cytoarchitectonic characteristics in all species examined. We analyzed the minicolumnar organization of cells in layer III of Broca's area in 11 human and 9 great ape specimens. A semiautomated method was used to analyze digitized images of histological sections stained for Nissl substance. Horizontal spacing distance and gray level index (GLI; or the area fraction occupied by cells) were quantified in all images. In contrast to area Tpt, the only cortical area for which comparative minicolumnar data have been published previously for humans and one of the great apes, we found no population-level asymmetry, for either horizontal spacing distance or GLI. Only human females exhibited a leftward asymmetry in GLI. GLI was lower in humans than in great apes (P < 0.001), allowing more space for connectivity in layer III. In humans, horizontal spacing distance was greater than in great apes but smaller relative to brain size. (c) 2008 Wiley-Liss, Inc.

Temporal factors in the extinction of fear in inbred mouse strains differing in extinction efficacy.

PubMed

MacPherson, Kathryn; Whittle, Nigel; Camp, Marguerite; Gunduz-Cinar, Ozge; Singewald, Nicolas; Holmes, Andrew

2013-07-05

Various neuropsychiatric conditions, including posttraumatic stress disorder (PTSD), are characterized by deficient fear extinction, but individuals differ greatly in risk for these. While there is growing evidence that fear extinction is influenced by certain procedural variables, it is unclear how these influences might vary across individuals and subpopulations. To model individual differences in fear extinction, prior studies identified a strain of inbred mouse, 129S1/SvImJ (S1), which exhibits a profound deficit in fear extinction, as compared to other inbred strains, such as C57BL/6J (B6). Here, we assessed the effects of procedural variables on the impaired extinction phenotype of the S1 strain and, by comparison, the extinction-intact B6 strain. The variables studied were 1) the interval between conditioning and extinction, 2) the interval between cues during extinction training, 3) single-cue exposure before extinction training, and 4) extinction of a second-order conditioned cue. Conducting extinction training soon after ('immediately') conditioning attenuated fear retrieval in S1 mice and impaired extinction in B6 mice. Spacing cue presentations with long inter-trial intervals during extinction training augmented fear in S1 and B6 mice. The effect of spacing was lost with one-trial fear conditioning in B6, but not S1 mice. A single exposure to a conditioned cue before extinction training did not alter extinction retrieval, either in B6 or S1 mice. Both the S1 and B6 strains exhibited robust second-order fear conditioning, in which a cue associated with footshock was sufficient to serve as a conditioned exciter to condition a fear association to a second cue. B6 mice extinguished the fear response to the second-order conditioned cue, but S1 mice failed to do so. These data provide further evidence that fear extinction is strongly influenced by multiple procedural variables and is so in a highly strain-dependent manner. This suggests that the efficacy of extinction-based behavioral interventions, such as exposure therapy, for trauma-related anxiety disorders will be determined by the procedural parameters employed and the degree to which the patient can extinguish.

Germination phenology of some Great Basin native annual forb species

Treesearch

Tara A. Forbis

2010-01-01

Great Basin native plant communities are being replaced by the annual invasive cheatgrass Bromus tectorum. Cheatgrass exhibits a germination syndrome that is characteristic of facultative winter annuals. Although perennials dominate these communities, native annuals are present at many sites. Germination timing is often an important predictor of competitive...

Statistical characteristics of cloud variability. Part 1: Retrieved cloud liquid water path at three ARM sites: Observed cloud variability at ARM sites

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

Huang, Dong; Campos, Edwin; Liu, Yangang

2014-09-17

Statistical characteristics of cloud variability are examined for their dependence on averaging scales and best representation of probability density function with the decade-long retrieval products of cloud liquid water path (LWP) from the tropical western Pacific (TWP), Southern Great Plains (SGP), and North Slope of Alaska (NSA) sites of the Department of Energy’s Atmospheric Radiation Measurement Program. The statistical moments of LWP show some seasonal variation at the SGP and NSA sites but not much at the TWP site. It is found that the standard deviation, relative dispersion (the ratio of the standard deviation to the mean), and skewness allmore » quickly increase with the averaging window size when the window size is small and become more or less flat when the window size exceeds 12 h. On average, the cloud LWP at the TWP site has the largest values of standard deviation, relative dispersion, and skewness, whereas the NSA site exhibits the least. Correlation analysis shows that there is a positive correlation between the mean LWP and the standard deviation. The skewness is found to be closely related to the relative dispersion with a correlation coefficient of 0.6. The comparison further shows that the log normal, Weibull, and gamma distributions reasonably explain the observed relationship between skewness and relative dispersion over a wide range of scales.« less

Interannual variability of Indian Ocean subtropical mode water subduction rate

NASA Astrophysics Data System (ADS)

Ma, Jie; Lan, Jian

2017-06-01

The interannual variation of Indian Ocean subtropical mode water (IOSTMW) subduction rate in the Southwest Indian Ocean from 1980 to 2007 is investigated in this paper based on Simple Ocean Data Assimilation (SODA) outputs. Climatology of subduction rate exceeds 75 m/year in the IOSTMW formation area. The renewal time of permanent pycnocline water mass based on the subduction rate is calculated for each density class: 3-6 years for IOSTMW (25.8 < σ θ < 26.2 kg m-3). Subduction rate in the Southwest Indian Ocean subtropical gyre exhibits a great year-to-year variability. This interannual variations of the IOSTMW subduction rate is primarily dominated by the lateral induction term, associated with the interannual variations of strong meridional gradient of winter mixed layer depth (MLD). The slope of the mixed layer depth in the mode water is closely linked to the large variations of deep late winter MLD in the mid-latitudes and negligible variations of shallow winter MLD in lower latitudes. It is further identified that the interannual variation of late winter MLD in this area is largely controlled by the latent and sensible heat flux components. The water volume of the permanent pycnocline in the IOSTMW distribution area is also found to show a significant interannual variability, and it is well correlated with the interannual variation of subduction rate.

Spatio-temporal variability of dryness/wetness in the middle and lower reaches of the Yangtze River Basin and correlation with large-scale climatic factors

NASA Astrophysics Data System (ADS)

Chen, Xinchi; Zhang, Liping; Zou, Lei; Shan, Lijie; She, Dunxian

2018-02-01

The middle and lower reaches of the Yangtze River Basin (MLYR) are greatly affected by frequent drought/flooding events and abrupt alternations of these events in China. The purpose of this study is to analyze the spatial and temporal variability of dryness/wetness based on the data obtained from 75 meteorological stations in the MLYR for the period 1960-2015 and investigate the correlations between dryness/wetness and atmospheric circulation factors. The empirical orthogonal function method was applied in this study based on the monthly Standardized Precipitation Index at a 12-month time scale. The first leading pattern captured the same characteristics of dryness/wetness over the entire MLYR area and accounted for 40.87% of the total variance. Both the second and third leading patterns manifested as regional features of variability over the entire MLYR. The cross-wavelet transform method was applied to explore the potential relationship between the three leading patterns and the large-scale climate factors, and finally the relationships between drought/wetness events and climate factors were also analyzed. Our results indicated that the main patterns of dryness/wetness were primarily associated with the Niño 3.4, Indian Ocean Dipole, Southern Oscillation Index and Northern Oscillation Index, with the first pattern exhibiting noticeable periods and remarkable changes in phase with the indices.

Estimating the relative contributions of human withdrawals and climate variability to changes in groundwater

NASA Astrophysics Data System (ADS)

Swenson, S. C.; Lawrence, D. M.

2014-12-01

Estimating the relative contributions of human withdrawals and climate variability to changes in groundwater is a challenging task at present. One method that has been used recently is a model-data synthesis combining GRACE total water storage estimates with simulated water storage estimates from land surface models. In this method, water storage changes due to natural climate variations simulated by a model are removed from total water storage changes observed by GRACE; the residual is then interpreted as anthropogenic groundwater change. If the modeled water storage estimate contains systematic errors, these errors will also be present in the residual groundwater estimate. For example, simulations performed with the Community Land Model (CLM; the land component of the Community Earth System Model) generally show a weak (as much as 50% smaller) seasonal cycle of water storage in semi-arid regions when compared to GRACE satellite water storage estimates. This bias propagates into GRACE-CLM anthropogenic groundwater change estimates, which then exhibit unphysical seasonal variability. The CLM bias can be traced to the parameterization of soil evaporative resistance. Incorporating a new soil resistance parameterization in CLM greatly reduces the seasonal bias with respect to GRACE. In this study, we compare the improved CLM water storage estimates to GRACE and discuss the implications for estimates of anthropogenic groundwater withdrawal, showing examples for the Middle East and Southwestern United States.

A model for evaluating the social performance of construction waste management.

PubMed

Yuan, Hongping

2012-06-01

It has been determined by existing literature that a lot of research efforts have been made to the economic performance of construction waste management (CWM), but less attention is paid to investigation of the social performance of CWM. This study therefore attempts to develop a model for quantitatively evaluating the social performance of CWM by using a system dynamics (SD) approach. Firstly, major variables affecting the social performance of CWM are identified and a holistic system for assessing the social performance of CWM is formulated in line with feedback relationships underlying these variables. The developed system is then converted into a SD model through the software iThink. An empirical case study is finally conducted to demonstrate application of the model. Results of model validation indicate that the model is robust and reasonable to reflect the situation of the real system under study. Findings of the case study offer helpful insights into effectively promoting the social performance of CWM of the project investigated. Furthermore, the model exhibits great potential to function as an experimental platform for dynamically evaluating effects of management measures on improving the social performance of CWM of construction projects. Copyright © 2012 Elsevier Ltd. All rights reserved.

Land change variability and human-environment dynamics in the United States Great Plains

USGS Publications Warehouse

Drummond, M.A.; Auch, Roger F.; Karstensen, K.A.; Sayler, K. L.; Taylor, Janis L.; Loveland, Thomas R.

2012-01-01

Land use and land cover changes have complex linkages to climate variability and change, biophysical resources, and socioeconomic driving forces. To assess these land change dynamics and their causes in the Great Plains, we compare and contrast contemporary changes across 16 ecoregions using Landsat satellite data and statistical analysis. Large-area change analysis of agricultural regions is often hampered by change detection error and the tendency for land conversions to occur at the local-scale. To facilitate a regional-scale analysis, a statistical sampling design of randomly selected 10 km × 10 km blocks is used to efficiently identify the types and rates of land conversions for four time intervals between 1973 and 2000, stratified by relatively homogenous ecoregions. Nearly 8% of the overall Great Plains region underwent land-use and land-cover change during the study period, with a substantial amount of ecoregion variability that ranged from less than 2% to greater than 13%. Agricultural land cover declined by more than 2% overall, with variability contingent on the differential characteristics of regional human–environment systems. A large part of the Great Plains is in relatively stable land cover. However, other land systems with significant biophysical and climate limitations for agriculture have high rates of land change when pushed by economic, policy, technology, or climate forcing factors. The results indicate the regionally based potential for land cover to persist or fluctuate as land uses are adapted to spatially and temporally variable forcing factors.

Jamaica Bay studies III: Abiotic determinants of distribution and abundance of gulls ( Larus)

NASA Astrophysics Data System (ADS)

Burger, Joanna

1983-02-01

The distribution and abundance of gulls were examined at Jamaica Bay Wildlife Refuge (New York) from 31 May 1978 to 31 May 1979. Gulls were found to be affected by tidal, temporal and weather-related factors. The distribution of gulls was affected primarily by tidal factors on the bay, and by temporal (seasonal, circadian) and weather-related factors on the freshwater ponds. The most important weather-related factors were temperature, wind velocity and wind direction. Herring ( L. argentatus), great black-backed ( L. fuscus) and ring-billed gulls ( L. delawarensis) fed on the bay at low tides, and used the ponds at high tide. Laughing gulls ( L. atricilla) fed on the bay at low tide and on rising tides. Herring and great black-backed gulls were present all year, but were most abundant in the winter, ring-billed gulls were abundant in spring and early fall, and laughing gulls were present in the summer following the breeding season but were absent in winter. Gulls used the ponds during high velocity, north winds, when they usually rested or preened. Multiple regression models were used to determine the factors explaining the variability in the numbers of gulls. Temporal variables were important contributors to accounting for the variability in the numbers of great black-backed and herring gulls only; tidal variables were significant for great black-backed and herring gulls on the bay, and for ring-billed and laughing gulls on all areas; and weather variables were significant for all species.

VARIABILITY, PATTERN, AND SENSITIVITY OF ECOLOGICAL INDICAORS FOR NEARSHORE REGIONS OF THE GREAT LAKES

EPA Science Inventory

Associated with the Great Lakes Environmental Indicators (GLEI) project of the EaGLe program, we are evaluating a suite of indicators of ecological condition for the nearshore region of U.S. shorelines of the Great Lakes. The evaluation includes sampling conducted at limited fix...

Hydrologic, land cover and seasonal patterns of waterborne pathogens in great lakes tributaries

USDA-ARS?s Scientific Manuscript database

Great Lakes tributaries deliver waterborne pathogens from a host of sources. To examine the hydrologic, land cover, and seasonal variability of waterborne pathogens, protozoa (2), pathogenic bacteria (4) and human (8) and bovine (8) viruses from eight rivers were monitored in the Great Lakes watersh...

The role of C3 and C4 grasses to interannual variability in remotely sensed ecosystem performance over the US Great Plains

USGS Publications Warehouse

Ricotta, C.; Reed, B.C.; Tieszen, L.T.

2003-01-01

Time integrated normalized difference vegetation index (??NDVI) derived from National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR) multi-temporal imagery over a 10-year period (1989-1998) was used as a surrogate for primary production to investigate the impact of interannual climate variability on grassland performance for central and northern US Great Plains. First, the contribution of C3 and C4 species abundance to the major grassland ecosystems of the US Great Plains is described. Next, the relation between mean ??NDVI and the ??NDVI coefficient of variation (CV ??NDVI) used as a proxy for interranual climate variability is analysed. Results suggest that the differences in the long-term climate control over ecosystem performance approximately coincide with changes between C3- and C4-dominant grassland classes. Variation in remotely sensed net primary production over time is higher for the southern and western plains grasslands (primary C4 grasslands), whereas the C3-dominated classes in the northern and eastern portion of the US Great Plains, generally show lower CV ??NDVI values.

Neutral-Line Magnetic Shear and Enhanced Coronal Heating in Solar Active Regions

NASA Technical Reports Server (NTRS)

Falconer, D. A.; Moore, R. L.; Porter, J. G.; Gary, G. A.; Shimizu, T.

1997-01-01

By examining the magnetic structure at sites in the bright coronal interiors of active regions that are not flaring but exhibit persistent strong coronal heating, we establish some new characteristics of the magnetic origins of this heating. We have examined the magnetic structure of these sites in five active regions, each of which was well observed by both the Yohkoh SXT and the Marshall Space Flight Center Vector Magnetograph and showed strong shear in its magnetic field along part of at least one neutral line (polarity inversion). Thus, we can assess whether this form of nonpotential field structure in active regions is a characteristic of the enhanced coronal heating and vice versa. From 27 orbits' worth of Yohkoh SXT images of the five active regions, we have obtained a sample of 94 persistently bright coronal features (bright in all images from a given orbit), 40 long (greater than or approximately equals 20,000 km) neutral-line segments having strong magnetic shear throughout (shear angle greater than 45 deg), and 39 long neutral-line segments having weak magnetic shear throughout (shear angle less than 45 deg). From this sample, we find that: (1) all of our persistently bright coronal features are rooted in magnetic fields that are stronger than 150 G; (2) nearly all (95%) of these enhanced coronal features are rooted near neutral lines (closer than 10,000 km); (3) a great majority (80%) of the bright features are rooted near strong-shear portions of neutral lines; (4) a great majority (85%) of long strong-shear segments of neutral lines have persistently bright coronal features rooted near them; (5) a large minority (40%) of long weak-shear segments of neutral lines have persistently bright coronal features rooted near them; and (6) the brightness of a persistently bright Coronal feature often changes greatly over a few hours. From these results, we conclude that most persistent enhanced heating of coronal loops in active regions: (1) requires the presence of a polarity inversion in the magnetic field near at least one of the loop footpoints; (2) is greatly aided by the presence of strong shear in the core magnetic field along that neutral line; and (3) is controlled by some variable process that acts in this magnetic environment. We infer that this variable process is low-lying reconnection accompanying flux cancellation.

Raman spectral observation of a new phase observed in nickel electrodes cycled to failure

NASA Technical Reports Server (NTRS)

Loyselle, Patricia L.; Shan, X.; Cornilsen, B. C.; Reid, Margaret A.

1991-01-01

A new phase is reported in nickel electrodes from Ni/H2 boilerplate cells which were cycled to failure in electrolyte of variable KOH concentration (21 to 36 percent). Raman spectra clearly show the presence of this phase, and these spectra have been used to estimate the amounts present on these electrodes. Ten of 12 electrodes examined contain this new phase. The cycle life at higher KOH concentrations (31 and 36 percent) was greatly reduced, and nickel electrodes from these cells exhibited extensive amounts of this new phase. The presence of this new phase correlates with cell failure defined by low end of discharge voltages. It is proposed that the lowered capacity and failure of these electrodes was caused by loss of active mass and formation of a phase with reduced electrochemical activity. These results indicate that formation of the new phase is accelerated at higher KOH concentrations.

Shape Evolution of Highly Lattice-Mismatched InN/InGaN Nanowire Heterostructures

NASA Astrophysics Data System (ADS)

Yan, Lifan; Hazari, Arnab; Bhattacharya, Pallab; Millunchick, Joanna M.

2018-02-01

We have investigated the structure and shape of GaN-based nanowires grown on (001) Si substrates for optoelectronic device applications. The nanowire heterostructures contained InN disks and In0.4Ga0.6N barrier layers in the active region. The resulting nanowire array comprised two differently shaped nanowires: shorter pencil-like nanowires and longer bead-like nanowires. The two different nanowire shapes evolve due to a variation in the In incorporation rate, which was faster for the bead-like nanowires. Both types of nanowires exhibited evidence of significant migration of both Ga and In during growth. Ga tended to diffuse away and down along the sidewalls, resulting in a Ga-rich shell for all nanowires. Despite the complex structure and great variability in the In composition, the optical properties of the nanowire arrays were very good, with strong luminescence peaking at ˜ 1.63 μm.

An internal X-cell pseudotumor in a black croaker (Cheilotrema saturnum).

PubMed

Kent, M L; Myers, M S; Wellings, S R; Elston, R A

1988-01-01

Cells closely resembling X-cells were the primary cellular component of a large pseudotumor in the viscera of a black croaker (Cheilotrema saturnum). The fish was captured in coastal waters off San Diego, California and was maintained at the Scripps Aquarium. After 2 years in captivity the fish exhibited extreme abdominal swelling due to a visceral mass, which weighed approximately one-fifth the total body weight. The cells associated with the pseudotumor were identified as X-cells due to their great variability in size, vesicular nuclei which stained negative for DNA and their formation of a pseudotumor. This is the first report of an X-cell pseudotumor in the visceral cavity. We agree with the hypothesis that the X-cell is a protozoan, and the description here of X-cells in a visceral pseudotumor in a fish of the family Sciaenidae associates an additional type of lesion with this enigmatic parasite.

Genome typing of nonhuman primate models: implications for biomedical research.

PubMed

Haus, Tanja; Ferguson, Betsy; Rogers, Jeffrey; Doxiadis, Gaby; Certa, Ulrich; Rose, Nicola J; Teepe, Robert; Weinbauer, Gerhard F; Roos, Christian

2014-11-01

The success of personalized medicine rests on understanding the genetic variation between individuals. Thus, as medical practice evolves and variation among individuals becomes a fundamental aspect of clinical medicine, a thorough consideration of the genetic and genomic information concerning the animals used as models in biomedical research also becomes critical. In particular, nonhuman primates (NHPs) offer great promise as models for many aspects of human health and disease. These are outbred species exhibiting substantial levels of genetic variation; however, understanding of the contribution of this variation to phenotypes is lagging behind in NHP species. Thus, there is a pivotal need to address this gap and define strategies for characterizing both genomic content and variability within primate models of human disease. Here, we discuss the current state of genomics of NHP models and offer guidelines for future work to ensure continued improvement and utility of this line of biomedical research. Copyright © 2014 Elsevier Ltd. All rights reserved.

137Cs in the meat of wild boars: a comparison of the impacts of Chernobyl and Fukushima.

PubMed

Steinhauser, Georg; Saey, Paul R J

The impact of Chernobyl on the 137 Cs activities found in wild boars in Europe, even in remote locations from the NPP, has been much greater than the impact of Fukushima on boars in Japan. Although there is great variability within the 137 Cs concentrations throughout the wild boar populations, some boars in southern Germany in recent years exhibit higher activity concentrations (up to 10,000 Bq/kg and higher) than the highest 137 Cs levels found in boars in the governmental food monitoring campaign (7900 Bq/kg) in Fukushima prefecture in Japan. The levels of radiocesium in boar appear to be more persistent than would be indicated by the constantly decreasing 137 Cs inventory observed in the soil which points to a food source that is highly retentive to 137 Cs contamination or to other radioecological anomalies that are not yet fully understood.

Linear enamel hypoplasia in the great apes: analysis by genus and locality.

PubMed

Hannibal, Darcy Lee; Guatelli-Steinberg, Debbie

2005-05-01

Most studies report a high prevalence of linear enamel hypoplasia (LEH) in the great apes relative to other nonhuman primates and some human populations. It is unclear if this difference is a direct result of poor health status for the great apes, or if it represents differential incidence due to a lower threshold (sensu Goodman and Rose, 1990 Am. J. Phys. Anthropol. [suppl.] 33:59-110) for the occurrence of enamel hypoplasia among great apes. This study uses the Smithsonian National Museum of Natural History's great ape collection to examine the prevalence of LEH, the most common type of hypoplasia observed. Frequencies of LEH are reported, as well as analyses by taxa and provenience. The study sample consists of 136 specimens and includes 41 gorillas, 25 chimpanzees, and 70 orangutans. Analyses of frequencies are presented for both individuals and teeth by taxonomic category and locality. Among the individuals in this study, 63.97% are affected by LEH. Overall, gorillas (29.27%) exhibit lower frequencies of LEH than chimpanzees (68.00%) and orangutans (82.86%). There is a marked difference in LEH frequencies between mountain and lowland gorillas. There is no difference in LEH frequencies between Sumatran and Bornean orangutans. A range of variation for the great apes in enamel hypoplasia frequencies is found when taxon and locality are considered. It is likely that both biological and environmental factors influence the high frequencies of enamel hypoplasia exhibited in the great apes. Copyright 2004 Wiley-Liss, Inc.

Temporal and spatial variability of frost-free seasons in the Great Lakes region of the United States

Treesearch

Lejiang Yu; Shiyuan Zhong; Xindi Bian; Warren E. Heilman; Jeffrey A. Andresen

2014-01-01

The frequency and timing of frost events and the length of the growing season are critical limiting factors in many human and natural ecosystems. This study investigates the temporal and spatial variability of the date of last spring frost (LSF), the date of first fall frost (FFF), and the length of the frost-free season (FFS) in the Great Lakes region of the United...

Assessment of left ventricular function in healthy Great Danes and in Great Danes with dilated cardiomyopathy using speckle tracking echocardiography.

PubMed

Pedro, B; Stephenson, H; Linney, C; Cripps, P; Dukes-McEwan, J

2017-08-01

Assess global circumferential and radial systolic and diastolic myocardial function with speckle tracking echocardiography (STE) in healthy Great Danes (GD) and in GD diagnosed with dilated cardiomyopathy (DCM). Eighty-nine GD were included in the study: 39 healthy (normal group [NORMg]) and 50 diagnosed with DCM (DCMg). This was a retrospective study. Signalment and echocardiographic diagnosis were obtained from the medical records of GD assessed between 2008 and 2012. Speckle tracking echocardiography analysis of circumferential (C) and radial (R) strain (St) and strain rate (SR) in systole (S), early (E) and late (A) diastole was performed at the levels of the mitral valve (MV), papillary muscles (PM) and apex (Ap) of the left ventricle. Univariable and multivariable analysis was performed to identify differences between groups. Speckle tracking echocardiography variables increase from the MV towards the Ap of the left ventricle in both NORMg and DCMg dogs, some reaching statistical significance. Most of the variables (28/31) were lower in DCMg than in NORMg dogs: statistically significant variables included radial SR at the Ap in systole (p=0.029), radial strain at the PM (p=0.012), circumferential SR at the PM in systole (p=0.031), circumferential and radial SR at the MV in early diastole (p=0.019 and p=0.049, respectively). There are significant differences in STE variables between NORMg and DCMg Great Danes, although the overlap between the two groups may indicate that these variables are not sufficiently discriminatory. STE variables are not sufficiently sensitive to use in isolation as a screening method. Copyright © 2017 Elsevier B.V. All rights reserved.

Highly Sensitive and Reproducible SERS Sensor for Biological pH Detection Based on a Uniform Gold Nanorod Array Platform.

PubMed

Bi, Liyan; Wang, Yunqing; Yang, Ying; Li, Yuling; Mo, Shanshan; Zheng, Qingyin; Chen, Lingxin

2018-05-09

Conventional research on surface-enhanced Raman scattering (SERS)-based pH sensors often depends on nanoparticle aggregation, whereas the variability in nanoparticle aggregation gives rise to poor repeatability in the SERS signal. Herein, we fabricated a gold nanorod array platform via an efficient evaporative self-assembly method. The platform exhibits great SERS sensitivity with an enhancement factor of 5.6 × 10 7 and maintains excellent recyclability and reproducibility with relative standard deviation (RSD) values of less than 8%. On the basis of the platform, we developed a highly sensitive bovine serum albumin (BSA)-coated 4-mercaptopyridine (4-MPy)-linked (BMP) SERS-based pH sensor to report pH ranging from pH 3.0 to pH 8.0. The intensity ratio variation of 1004 and 1096 cm -1 in 4-MPy showed excellent pH sensitivity, which decreased as the surrounding pH increased. Furthermore, this BMP SERS-based pH sensor was employed to measure the pH value in C57BL/6 mouse blood. We have demonstrated that the pH sensor has great advantages such as good stability, reliability, and accuracy, which could be extended for the design of point-of-care devices.

Constancy despite variability: Local and regional macrofaunal diversity in intertidal seagrass beds

NASA Astrophysics Data System (ADS)

Boyé, Aurélien; Legendre, Pierre; Grall, Jacques; Gauthier, Olivier

2017-12-01

The importance of seagrass habitat for the diversity of benthic fauna has been extensively studied worldwide. Most of the information available is, however, about α diversity while little consideration has been given to β diversity. To fill the knowledge gaps regarding the variability of epifaunal and infaunal seagrass assemblages at large spatial and temporal scales, we scrutinized an extensive dataset covering five years of monitoring of eight intertidal Zostera marina meadows around Brittany (France). High species richness arose at the regional scale from the combination of high local diversity of the meadows and substantial among-meadows β diversity. Epifauna and infauna appeared as distinct self-communities as they displayed different spatial and temporal patterns and varied in their responses to local hydrological conditions. Infauna had higher total β diversity than epifauna due to a tighter link to the great variability of local environmental conditions in the region. Both exhibited substantial variations in species composition and community structure with variations of dominant species that were accompanied by extensive change in numerous rare species. The dominant epifaunal species were all grazers. Changes in species composition were induced mostly by species replacement and rarely by richness differences between meadows. Indeed, species richness remained within a narrow range for all seagrass beds, suggesting a potential carrying capacity for species richness of the meadows. Overall, all meadows contributed equally to the regional turnover of seagrass macrofauna, emphasizing high variability and complementarity among beds at the regional scale. The implications of this substantial within-seagrass variability for the functioning of benthic ecosystems at broad scale and for conservation purposes in habitat mosaics warrant further investigations but our results clearly advocate taking into account within-habitat variation when evaluating the diversity of benthic habitats and the potential effect of habitat loss.

BET surface area distributions in polar stream sediments: Implications for silicate weathering in a cold-arid environment

USGS Publications Warehouse

Marra, Kristen R.; Elwood Madden, Megan E; Soreghan, Gerilyn S.; Hall, Brenda L

2014-01-01

BET surface area values are critical for quantifying the amount of potentially reactive sediments available for chemical weathering and ultimately, prediction of silicate weathering fluxes. BET surface area values of fine-grained (<62.5 μm) sediment from the hyporheic zone of polar glacial streams in the McMurdo Dry Valleys, Antarctica (Wright and Taylor Valleys) exhibit a wide range (2.5–70.6 m2/g) of surface area values. Samples from one (Delta Stream, Taylor Valley) of the four sampled stream transects exhibit high values (up to 70.6 m2/g), which greatly exceed surface area values from three temperate proglacial streams (0.3–12.1 m2/g). Only Clark stream in Wright Valley exhibits a robust trend with distance, wherein surface area systematically decreases (and particle size increases) in the mud fraction downstream, interpreted to reflect rapid dissolution processes in the weathering environment. The remaining transects exhibit a range in variability in surface area distributions along the length of the channel, likely related to variations in eolian input to exposed channel beds, adjacent snow drifts, and to glacier surfaces, where dust is trapped and subsequently liberated during summer melting. Additionally, variations in stream discharge rate, which mobilizes sediment in pulses and influences water:rock ratios, the origin and nature of the underlying drift material, and the contribution of organic acids may play significant roles in the production and mobilization of high-surface area sediment. This study highlights the presence of sediments with high surface area in cold-based glacier systems, which influences models of chemical denudation rates and the impact of glacial systems on the global carbon cycle.

Skip-row Planting Patterns Stabilize Corn Grain Yields in the Central Great Plains

USDA-ARS?s Scientific Manuscript database

The highly variable climate of the Central Great Plains makes dryland corn (Zea mays) production a risky enterprise. Twenty-three field trials were conducted across the Central Great Plains from 2004 through 2006 to quantify the effect of various skip-row planting patterns and plant populations on g...

The 1985 central chile earthquake: a repeat of previous great earthquakes in the region?

PubMed

Comte, D; Eisenberg, A; Lorca, E; Pardo, M; Ponce, L; Saragoni, R; Singh, S K; Suárez, G

1986-07-25

A great earthquake (surface-wave magnitude, 7.8) occurred along the coast of central Chile on 3 March 1985, causing heavy damage to coastal towns. Intense foreshock activity near the epicenter of the main shock occurred for 11 days before the earthquake. The aftershocks of the 1985 earthquake define a rupture area of 170 by 110 square kilometers. The earthquake was forecast on the basis of the nearly constant repeat time (83 +/- 9 years) of great earthquakes in this region. An analysis of previous earthquakes suggests that the rupture lengths of great shocks in the region vary by a factor of about 3. The nearly constant repeat time and variable rupture lengths cannot be reconciled with time- or slip-predictable models of earthquake recurrence. The great earthquakes in the region seem to involve a variable rupture mode and yet, for unknown reasons, remain periodic. Historical data suggest that the region south of the 1985 rupture zone should now be considered a gap of high seismic potential that may rupture in a great earthquake in the next few tens of years.

Shell-binary nanoparticle materials with variable electrical and electro-mechanical properties.

PubMed

Zhang, P; Bousack, H; Dai, Y; Offenhäusser, A; Mayer, D

2018-01-18

Nanoparticle (NP) materials with the capability to adjust their electrical and electro-mechanical properties facilitate applications in strain sensing technology. Traditional NP materials based on single component NPs lack a systematic and effective means of tuning their electrical and electro-mechanical properties. Here, we report on a new type of shell-binary NP material fabricated by self-assembly with either homogeneous or heterogeneous arrangements of NPs. Variable electrical and electro-mechanical properties were obtained for both materials. We show that the electrical and electro-mechanical properties of these shell-binary NP materials are highly tunable and strongly affected by the NP species as well as their corresponding volume fraction ratio. The conductivity and the gauge factor of these shell-binary NP materials can be altered by about five and two orders of magnitude, respectively. These shell-binary NP materials with different arrangements of NPs also demonstrate different volume fraction dependent electro-mechanical properties. The shell-binary NP materials with a heterogeneous arrangement of NPs exhibit a peaking of the sensitivity at medium mixing ratios, which arises from the aggregation induced local strain enhancement. Studies on the electron transport regimes and micro-morphologies of these shell-binary NP materials revealed the different mechanisms accounting for the variable electrical and electro-mechanical properties. A model based on effective medium theory is used to describe the electrical and electro-mechanical properties of such shell-binary nanomaterials and shows an excellent match with experiment data. These shell-binary NP materials possess great potential applications in high-performance strain sensing technology due to their variable electrical and electro-mechanical properties.

Memory in a fractional-order cardiomyocyte model alters properties of alternans and spontaneous activity

NASA Astrophysics Data System (ADS)

Comlekoglu, T.; Weinberg, S. H.

2017-09-01

Cardiac memory is the dependence of electrical activity on the prior history of one or more system state variables, including transmembrane potential (Vm), ionic current gating, and ion concentrations. While prior work has represented memory either phenomenologically or with biophysical detail, in this study, we consider an intermediate approach of a minimal three-variable cardiomyocyte model, modified with fractional-order dynamics, i.e., a differential equation of order between 0 and 1, to account for history-dependence. Memory is represented via both capacitive memory, due to fractional-order Vm dynamics, that arises due to non-ideal behavior of membrane capacitance; and ionic current gating memory, due to fractional-order gating variable dynamics, that arises due to gating history-dependence. We perform simulations for varying Vm and gating variable fractional-orders and pacing cycle length and measure action potential duration (APD) and incidence of alternans, loss of capture, and spontaneous activity. In the absence of ionic current gating memory, we find that capacitive memory, i.e., decreased Vm fractional-order, typically shortens APD, suppresses alternans, and decreases the minimum cycle length (MCL) for loss of capture. However, in the presence of ionic current gating memory, capacitive memory can prolong APD, promote alternans, and increase MCL. Further, we find that reduced Vm fractional order (typically less than 0.75) can drive phase 4 depolarizations that promote spontaneous activity. Collectively, our results demonstrate that memory reproduced by a fractional-order model can play a role in alternans formation and pacemaking, and in general, can greatly increase the range of electrophysiological characteristics exhibited by a minimal model.

Kinematic evaluation of the finger's interphalangeal joints coupling mechanism--variability, flexion-extension differences, triggers, locking swanneck deformities, anthropometric correlations.

PubMed

Leijnse, J N A L; Quesada, P M; Spoor, C W

2010-08-26

The human finger contains tendon/ligament mechanisms essential for proper control. One mechanism couples the movements of the interphalangeal joints when the (unloaded) finger is flexed with active deep flexor. This study's aim was to accurately determine in a large finger sample the kinematics and variability of the coupled interphalangeal joint motions, for potential clinical and finger model validation applications. The data could also be applied to humanoid robotic hands. Sixty-eight fingers were measured in seventeen hands in nine subjects. Fingers exhibited great joint mobility variability, with passive proximal interphalangeal hyperextension ranging from zero to almost fifty degrees. Increased measurement accuracy was obtained by using marker frames to amplify finger segment motions. Gravitational forces on the marker frames were not found to invalidate measurements. The recorded interphalangeal joint trajectories were highly consistent, demonstrating the underlying coupling mechanism. The increased accuracy and large sample size allowed for evaluation of detailed trajectory variability, systematic differences between flexion and extension trajectories, and three trigger types, distinct from flexor tendon triggers, involving initial flexion deficits in either proximal or distal interphalangeal joint. The experimental methods, data and analysis should advance insight into normal and pathological finger biomechanics (e.g., swanneck deformities), and could help improve clinical differential diagnostics of trigger finger causes. The marker frame measuring method may be useful to quantify interphalangeal joints trajectories in surgical/rehabilitative outcome studies. The data as a whole provide the most comprehensive collection of interphalangeal joint trajectories for clinical reference and model validation known to us to date. 2010 Elsevier Ltd. All rights reserved.

Crop responses to climatic variation

PubMed Central

Porter, John R; Semenov, Mikhail A

2005-01-01

The yield and quality of food crops is central to the well being of humans and is directly affected by climate and weather. Initial studies of climate change on crops focussed on effects of increased carbon dioxide (CO2) level and/or global mean temperature and/or rainfall and nutrition on crop production. However, crops can respond nonlinearly to changes in their growing conditions, exhibit threshold responses and are subject to combinations of stress factors that affect their growth, development and yield. Thus, climate variability and changes in the frequency of extreme events are important for yield, its stability and quality. In this context, threshold temperatures for crop processes are found not to differ greatly for different crops and are important to define for the major food crops, to assist climate modellers predict the occurrence of crop critical temperatures and their temporal resolution. This paper demonstrates the impacts of climate variability for crop production in a number of crops. Increasing temperature and precipitation variability increases the risks to yield, as shown via computer simulation and experimental studies. The issue of food quality has not been given sufficient importance when assessing the impact of climate change for food and this is addressed. Using simulation models of wheat, the concentration of grain protein is shown to respond to changes in the mean and variability of temperature and precipitation events. The paper concludes with discussion of adaptation possibilities for crops in response to drought and argues that characters that enable better exploration of the soil and slower leaf canopy expansion could lead to crop higher transpiration efficiency. PMID:16433091

When ice meets water: Sub-aqueous melt and its relevance in various settings

NASA Astrophysics Data System (ADS)

Truffer, M.; Motyka, R. J.

2014-12-01

The largest glacier changes are primarily observed in settings where ice flows into a proglacial water body. However, the responses to this interaction are not uniform. Rapidly retreating glaciers can occur in close vicinity to advancing ones. Calving styles and glacier morphologies vary greatly as well. Temperate lake-calving glaciers frequently exhibit floating tongues; but this is rarely observed on temperate tidewater glaciers. Calving styles range from mostly sub-aerial calving to full-thickness calving to slow detachment of large ice bergs. In addition to the more obvious mechanical calving, glaciers lose mass at their termini through sub-aqueous melting. Melt rates of submerged ice have been shown to vary over several orders of magnitudes, and can range up to several meters per day. This large range is a consequence of different proglacial water temperatures, and of different modes of water transport. Water convection in proglacial water bodies can be driven by winds and tides, but subglacial water discharge is commonly the strongest and most variable driver. Here we attempt to relate the variability of forcings and melt rates to the various morphologies and calving styles of different water-terminating glaciers. The highest melt rates are observed at low-latitude tidewater glaciers, where ocean water can be warm (7 - 10 deg C) and subglacial discharge high. In such settings, sub-aqueous melt can reach the same magnitude as ice flux delivered to the terminus and it can control ice terminus position. Polar tidewater glaciers, such as those in Greenland, often exhibit floating tongues. Although melt rates are likely much lower, they can have a large effect under a floating tongue because of the much larger exposure of ice to water. Changes in melt rates can therefore affect the stability of such floating tongues. Low melt rates occur at some ice shelves at high latitudes, where the temperature and freshwater forcings are small. This situation can also occur at temperate lake-calving glaciers, which often flow into lakes of near freezing temperatures. Due to the very small density differences between subglacial discharge and ambient lake water, convection below the floating tongue is minor or non-existent.. This is in great contrast to fresh water entering a saline environment.

Spatial, seasonal, and source variability in the stable oxygen and hydrogen isotopic composition of tap waters throughout the USA

USGS Publications Warehouse

Landwehr, Jurate M.; Coplen, Tyler B.; Stewart, David W.

2013-01-01

To assess spatial, seasonal, and source variability in stable isotopic composition of human drinking waters throughout the entire USA, we have constructed a database of δ18O and δ2H of US tap waters. An additional purpose was to create a publicly available dataset useful for evaluating the forensic applicability of these isotopes for human tissue source geolocation. Samples were obtained at 349 sites, from diverse population centres, grouped by surface hydrologic units for regional comparisons. Samples were taken concurrently during two contrasting seasons, summer and winter. Source supply (surface, groundwater, mixed, and cistern) and system (public and private) types were noted. The isotopic composition of tap waters exhibits large spatial and regional variation within each season as well as significant at-site differences between seasons at many locations, consistent with patterns found in environmental (river and precipitation) waters deriving from hydrologic processes influenced by geographic factors. However, anthropogenic factors, such as the population of a tap’s surrounding community and local availability from diverse sources, also influence the isotopic composition of tap waters. Even within a locale as small as a single metropolitan area, tap waters with greatly differing isotopic compositions can be found, so that tap water within a region may not exhibit the spatial or temporal coherence predicted for environmental water. Such heterogeneities can be confounding factors when attempting forensic inference of source water location, and they underscore the necessity of measurements, not just predictions, with which to characterize the isotopic composition of regional tap waters. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

Scale-up of a physiologically-based pharmacokinetic model to predict the disposition of monoclonal antibodies in monkeys.

PubMed

Glassman, Patrick M; Chen, Yang; Balthasar, Joseph P

2015-10-01

Preclinical assessment of monoclonal antibody (mAb) disposition during drug development often includes investigations in non-human primate models. In many cases, mAb exhibit non-linear disposition that relates to mAb-target binding [i.e., target-mediated disposition (TMD)]. The goal of this work was to develop a physiologically-based pharmacokinetic (PBPK) model to predict non-linear mAb disposition in plasma and in tissues in monkeys. Physiological parameters for monkeys were collected from several sources, and plasma data for several mAbs associated with linear pharmacokinetics were digitized from prior literature reports. The digitized data displayed great variability; therefore, parameters describing inter-antibody variability in the rates of pinocytosis and convection were estimated. For prediction of the disposition of individual antibodies, we incorporated tissue concentrations of target proteins, where concentrations were estimated based on categorical immunohistochemistry scores, and with assumed localization of target within the interstitial space of each organ. Kinetics of target-mAb binding and target turnover, in the presence or absence of mAb, were implemented. The model was then employed to predict concentration versus time data, via Monte Carlo simulation, for two mAb that have been shown to exhibit TMD (2F8 and tocilizumab). Model predictions, performed a priori with no parameter fitting, were found to provide good prediction of dose-dependencies in plasma clearance, the areas under plasma concentration versu time curves, and the time-course of plasma concentration data. This PBPK model may find utility in predicting plasma and tissue concentration versus time data and, potentially, the time-course of receptor occupancy (i.e., mAb-target binding) to support the design and interpretation of preclinical pharmacokinetic-pharmacodynamic investigations in non-human primates.

Genetic spatial structure of an anchialine cave annelid indicates connectivity within - but not between - islands of the Great Bahama Bank.

PubMed

Gonzalez, Brett C; Martínez, Alejandro; Borda, Elizabeth; Iliffe, Thomas M; Fontaneto, Diego; Worsaae, Katrine

2017-04-01

Land-locked anchialine blue holes are karstic sinkholes and caves with tidally influenced, vertically stratified water bodies that harbor endemic fauna exhibiting variable troglomorphic features. These habitats represent island-like systems, which can serve to elucidate evolutionary and biogeographic processes at local scales. We investigated whether the 'continuous spelean corridor' hypothesis may elucidate the biogeographical distributions of the stygobitic annelid Pelagomacellicephala iliffei (Polynoidae) collected from the Great Bahama and Caicos Banks of the Bahamas Archipelago. Phylogenetic reconstructions were performed using Bayesian Inference on individual and combined datasets of three molecular markers (16S rDNA, COI, 18S rDNA) and species delimitation employed three widely accepted methods in DNA taxonomy, namely GMYC, bPTP, and ABGD. Mantel tests were used to test the effect of geography on genetic structure. Using these analyses, we recovered five independently evolving entities of the focal species across four islands of the Great Bahama Bank including Cat, Eleuthera, Exumas, and Long. Genetic data yielded strong correlations between islands and phylogenetic entities, signifying independent evolutionary histories within anchialine caves across the platform. The island of Eleuthera showed intra-island gene flow and dispersal capabilities between blue holes separated by 115km, providing evidence of a crevicular spelean corridor within the island. However, no evidence of inter-island dispersal is present in the analyzed system. Consistent with previous biogeographic studies of cave crustaceans, the major barriers shaping the cave biota of the Bahamas Archipelago appears to be the deep trenches and channels separating the Bahamian banks. Copyright © 2017 Elsevier Inc. All rights reserved.

Using adjunct forest inventory methodology to quantify pinyon jay habitat in the great basin

Treesearch

Christopher Witt

2015-01-01

Pinyon jays (Gymnorhinus cyanocephalus) are the principal dispersal agent for pinyon pine seeds in the Great Basin region of the Intermountain West. However, Pinyon jays have exhibited significant population declines over much their range in recent decades, even as pinyon-juniper woodlands appear to have been expanding over the past 150 years. In...

Field-induced refractive index variation in the dark conglomerate phase for polarization-independent switchable liquid crystal lenses.

PubMed

Milton, H E; Nagaraj, M; Kaur, S; Jones, J C; Morgan, P B; Gleeson, H F

2014-11-01

Liquid crystal lenses are an emerging technology that can provide variable focal power in response to applied voltage. Many designs for liquid-crystal-based lenses are polarization dependent, so that 50% of light is not focused as required, making polarization-independent technologies very attractive. Recently, the dark conglomerate (DC) phase, which is an optically isotropic liquid crystalline state, has been shown to exhibit a large change in refractive index in response to an applied electric field (Δn=0.04). This paper describes computational modeling of the electrostatic solutions for two different types of 100 μm diameter liquid crystal lenses, which include the DC phase, demonstrating that it shows great potential for efficient isotropic optical switching in lenses. A feature of the field dependence of the refractive index change in the DC phase is that it is approximately linear in a certain range, leading to the prediction of excellent optical quality for driving fields in this regime. Interestingly, a simulated microlens is shown to exhibit two modes of operation: a positive lens based upon a uniform bulk change in refractive index at high voltages, and a negative lens resulting from the induction of a gradient index effect at intermediate voltages.

Autosomal Dominant Cataract: Intrafamilial Phenotypic Variability, Interocular Asymmetry, and Variable Progression in Four Chilean Families

PubMed Central

Shafie, Suraiya M.; Barria von-Bischhoffshausen, Fernando R.; Bateman, J. Bronwyn

2006-01-01

PURPOSE To document intrafamilial and interocular phenotypic variability of autosomal dominant cataract (ADC). DESIGN Prospective observational case series. METHODS We performed ophthalmologic examination in four Chilean ADC families. RESULTS The families exhibited variability with respect to morphology, location with the lens, color and density of cataracts among affected members. We documented asymmetry between eyes in the morphology, location within the lens, color and density of cataracts, and a variable rate of progression. CONCLUSIONS The cataracts in these families exhibit wide intrafamilial and interocular phenotypic variability, supporting the premise that the mutated genes are expressed differentially in individuals and between eyes; other genes or environmental factors may be the bases for this variability. Marked progression among some family members underscores the variable clinical course of a common mutation within a family. Like retinitis pigmentosa, classification of ADC will be most useful if based on the gene and specific mutation. PMID:16564818

40 CFR Appendix E to Part 132 - Great Lakes Water Quality Initiative Antidegradation Policy

Code of Federal Regulations, 2014 CFR

2014-07-01

... operational variability; (2) Changes in intake water pollutants; (3) Increasing the production hours of the... 40 Protection of Environment 22 2014-07-01 2013-07-01 true Great Lakes Water Quality Initiative... (CONTINUED) WATER PROGRAMS WATER QUALITY GUIDANCE FOR THE GREAT LAKES SYSTEM Pt. 132, App. E Appendix E to...

Long-Term Variability of Satellite Lake Surface Water Temperatures in the Great Lakes

NASA Astrophysics Data System (ADS)

Gierach, M. M.; Matsumoto, K.; Holt, B.; McKinney, P. J.; Tokos, K.

2014-12-01

The Great Lakes are the largest group of freshwater lakes on Earth that approximately 37 million people depend upon for fresh drinking water, food, flood and drought mitigation, and natural resources that support industry, jobs, shipping and tourism. Recent reports have stated (e.g., the National Climate Assessment) that climate change can impact and exacerbate a range of risks to the Great Lakes, including changes in the range and distribution of certain fish species, increased invasive species and harmful algal blooms, declining beach health, and lengthened commercial navigation season. In this study, we will examine the impact of climate change on the Laurentian Great Lakes through investigation of long-term lake surface water temperatures (LSWT). We will use the ATSR Reprocessing for Climate: Lake Surface Water Temperature & Ice Cover (ARC-Lake) product over the period 1995-2012 to investigate individual and interlake variability. Specifically, we will quantify the seasonal amplitude of LSWTs, the first and last appearances of the 4°C isotherm (i.e., an important identifier of the seasonal evolution of the lakes denoting winter and summer stratification), and interpret these quantities in the context of global interannual climate variability such as ENSO.

The role of C3 and C4 grasses to interannual variability in remotely sensed ecosystem performance over the US Great Plains

USGS Publications Warehouse

Ricotta, C.; Reed, Bradley C.; Tieszen, Larry L.

2003-01-01

Time integrated normalized difference vegetation index (ΣNDVI) derived from National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR) multi-temporal imagery over a 10-year period (1989–1998) was used as a surrogate for primary production to investigate the impact of interannual climate variability on grassland performance for central and northern US Great Plains. First, the contribution of C3 and C4 species abundance to the major grassland ecosystems of the US Great Plains is described. Next, the relation between mean ΣNDVI and the ΣNDVI coefficient of variation (CV ΣNDVI) used as a proxy for interannual climate variability is analysed. Results suggest that the differences in the long-term climatic control over ecosystem performance approximately coincide with changes between C3- and C4-dominant grassland classes. Variation in remotely sensed net primary production over time is higher for the southern and western plains grasslands (primarily C4 grasslands), whereas the C3-dominated classes in the northern and eastern portion of the US Great Plains, generally show lower CV ΣNDVI values.

Solar Cycle in the Heliosphere and Cosmic Rays

DTIC Science & Technology

2014-10-23

at the source surface at 2.5 solar radii around the Sun. OMF shows a great variability both in solar cycle and on the centennial scale (see Fig. 3...It is important to note that the centennial variability is great (Lockwood et al. 1999; Solanki et al. 2000) comparable with or even greater than the...be identified as spikes in production of cosmogenic isotope (10Be and 14C) records on the centennial -millennial time scale (e.g., Usoskin and

PDO and ENSO Sea Surface Temperature Anomalies Control Grassland Plant Production across the United States Great Plains

NASA Astrophysics Data System (ADS)

Parton, W. J.; Del Grosso, S. J.; Smith, W. K.; Chen, M.

2017-12-01

The El Nino Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO) are multi-annual to multi-decadal climate patterns defined by ocean temperature anomalies that can strongly modulate climate variability. Here we evaluated the impacts of PDO and ENSO sea surface temperature (SST) anomalies on observed grassland above ground plant production (ANPP; 1940 to 2015), spring (April to July) cumulative actual evapotranspiration (iAET; 1900 to 2015) , and satellite-derived growing season (April to October) cumulative normalized difference vegetation index (iNDVI 1982 to 2015) across the United States Great Plains. The results showed that grassland ANPP is well correlated to iAET (r2=0.69) and iNDVI (r2=0.50 to 0.70) for the Cheyenne Wyoming and Northeastern Colorado long-term ANPP sites. At the site scale, during the negative phase of the PDO, we find ANPP is much lower (25%) and that variability of iAET, iNDVI, and ANPP are much higher (2 to 3 times) compared to the warm phase PDO. Further, we find there is a high frequency of below normal iAET when PDO and ENSO SST's are both negative, while there is a high frequency of above normal iAET when PDO and ENSO values are positive. At the regional scale, iAET, iNDVI, and modeled ANPP data sets show that plant production and iAET values are high in the southern Great Plains and low in the northern Great Plains when spring PDO and ENSO are both in the positive phase, while the opposite pattern is observed when both PDO and ENSO are both in the negative phase. Variability of iAET, iNDVI, and modeled ANPP are much higher in the central Great Plains during the negative phase PDO. We demonstrate clearly that the PDO and ENSO SST anomalies have large impacts on mean and variability of grassland plant production across the Great Plains.

Identification of low and high frequency ranges for heart rate variability and blood pressure variability analyses using pharmacological autonomic blockade with atropine and propranolol in swine.

USDA-ARS?s Scientific Manuscript database

Understanding autonomic nervous system functioning, which mediates behavioral and physiological responses to stress, offers great potential for evaluation of farm animal stress and welfare. Evaluation of heart rate variability (HRV) and blood pressure variability (BPV), using time and frequency doma...

Effective Use of Discovery Learning to Improve Understanding of Factors That Affect Quality

ERIC Educational Resources Information Center

Mukherjee, Arup

2015-01-01

Undergraduate business majors are required to take a course in operations management. In this course, a great deal of emphasis is put on developing a good understanding of quality because this is likely to be the only required course that covers this important topic. Quality of output exhibits a great deal of variation. To produce high quality on…

The context for great lakes silviculture in the 21st century

Treesearch

David D. Reed

2004-01-01

Great Lakes forests were subject to a severe pulse of disturbance from the mid-19th century through the early 20th century that resulted from extensive harvesting and subsequent fires following European settlement. Today?s forest, in many ways, is exhibiting changes in area and demography that reflect recovery from this pulse of disturbance, as well as response to...

Breeding population of the Great Gray Owl (Strix nebulosa Forster) in Belarus: summary of recent knowledge

Treesearch

Alexey K. Tishechkin; Wassilij W. Gritschik; Valery N. Vorobiov; Gennady A. Mindlin

1997-01-01

A nearly isolated Great Gray Owl (Strix nebulosa Forster) population of 50-100 breeding pairs exists in southwestern and south-central Belarus and northern Ukraine. It exhibits rather high nesting density in particular forest tracts and is separated from populations in northwestern Russia by several hundred kilometers. No reliable data on residency,...

Increased gait variability may not imply impaired stride-to-stride control of walking in healthy older adults: Winner: 2013 Gait and Clinical Movement Analysis Society Best Paper Award.

PubMed

Dingwell, Jonathan B; Salinas, Mandy M; Cusumano, Joseph P

2017-06-01

Older adults exhibit increased gait variability that is associated with fall history and predicts future falls. It is not known to what extent this increased variability results from increased physiological noise versus a decreased ability to regulate walking movements. To "walk", a person must move a finite distance in finite time, making stride length (L n ) and time (T n ) the fundamental stride variables to define forward walking. Multiple age-related physiological changes increase neuromotor noise, increasing gait variability. If older adults also alter how they regulate their stride variables, this could further exacerbate that variability. We previously developed a Goal Equivalent Manifold (GEM) computational framework specifically to separate these causes of variability. Here, we apply this framework to identify how both young and high-functioning healthy older adults regulate stepping from each stride to the next. Healthy older adults exhibited increased gait variability, independent of walking speed. However, despite this, these healthy older adults also concurrently exhibited no differences (all p>0.50) from young adults either in how their stride variability was distributed relative to the GEM or in how they regulated, from stride to stride, either their basic stepping variables or deviations relative to the GEM. Using a validated computational model, we found these experimental findings were consistent with increased gait variability arising solely from increased neuromotor noise, and not from changes in stride-to-stride control. Thus, age-related increased gait variability likely precedes impaired stepping control. This suggests these changes may in turn precede increased fall risk. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of Physiochemical Factors on Prokaryotic Biodiversity in Malaysian Circumneutral Hot Springs.

PubMed

Chan, Chia S; Chan, Kok-Gan; Ee, Robson; Hong, Kar-Wai; Urbieta, María S; Donati, Edgardo R; Shamsir, Mohd S; Goh, Kian M

2017-01-01

Malaysia has a great number of hot springs, especially along the flank of the Banjaran Titiwangsa mountain range. Biological studies of the Malaysian hot springs are rare because of the lack of comprehensive information on their microbial communities. In this study, we report a cultivation-independent census to describe microbial communities in six hot springs. The Ulu Slim (US), Sungai Klah (SK), Dusun Tua (DT), Sungai Serai (SS), Semenyih (SE), and Ayer Hangat (AH) hot springs exhibit circumneutral pH with temperatures ranging from 43°C to 90°C. Genomic DNA was extracted from environmental samples and the V3-V4 hypervariable regions of 16S rRNA genes were amplified, sequenced, and analyzed. High-throughput sequencing analysis showed that microbial richness was high in all samples as indicated by the detection of 6,334-26,244 operational taxonomy units. In total, 59, 61, 72, 73, 65, and 52 bacterial phyla were identified in the US, SK, DT, SS, SE, and AH hot springs, respectively. Generally, Firmicutes and Proteobacteria dominated the bacterial communities in all hot springs. Archaeal communities mainly consisted of Crenarchaeota, Euryarchaeota, and Parvarchaeota. In beta diversity analysis, the hot spring microbial memberships were clustered primarily on the basis of temperature and salinity. Canonical correlation analysis to assess the relationship between the microbial communities and physicochemical variables revealed that diversity patterns were best explained by a combination of physicochemical variables, rather than by individual abiotic variables such as temperature and salinity.

Maternal Cultural Participation and Child Health Status in a Middle Eastern Context: Evidence from the Urban Health Study

PubMed Central

Khawaja, Marwan; Barazi, Rana; Linos, Natalie

2006-01-01

Background The negative effect of poverty on child health has been well established. However, rapid urbanization in developing countries prompts new research questions relating to socio-cultural practices and other related variables in these settings. Objective To examine the association between maternal cultural participation and child health status in impoverished neighbourhoods of Beirut, Lebanon. Methods A cross-sectional survey of 1,241 mothers with children under 5 years was conducted from randomly selected households in three impoverished neighbourhoods of diverse ethnic and religious make-up. The outcome variable was child health status (good/bad) as assessed by the mother. Maternal variables, including cultural participation, education, demographic, and environmental/structural factors were studied. Descriptive statistics and bivariate associations were provided using Pearson’s χ2 tests. Unadjusted and adjusted odds ratios were then obtained from binary logistic regression models. Results Two indicators of maternal cultural participation, namely watching entertaining television and attending movies/art exhibitions, were found to be significantly associated to child health status after controlling for other risk factors. The quality of water, the quality of local health services, and maternal education were also significantly associated with child health status. Household income, child gender, and household dampness had no significant association with child health status in this context. Conclusion Maternal cultural participation was a significant predictor of child health status in impoverished urban communities. Improving child health through culturally focused interventions for mothers, especially in deprived areas, may be great. PMID:17291314

Maternal cultural participation and child health status in a Middle Eastern context: evidence from an urban health study.

PubMed

Khawaja, M; Barazi, R; Linos, N

2007-03-01

The negative effect of poverty on child health has been well established. However, rapid urbanization in developing countries prompts new research questions relating to socio-cultural practices and other related variables in these settings. To examine the association between maternal cultural participation and child health status in impoverished neighbourhoods of Beirut, Lebanon. A cross-sectional survey of 1241 mothers with children aged less than 5 years was conducted from randomly selected households in three impoverished neighbourhoods of diverse ethnic and religious make-up. The outcome variable was child health status (good/bad) as assessed by the mother. Maternal variables, including cultural participation, education, demographic and environmental/structural factors, were studied. Descriptive statistics and bivariate associations were provided using Pearson's chi-square tests. Unadjusted and adjusted odds ratios were then obtained from binary logistic regression models. Two indicators of maternal cultural participation, namely watching entertaining television and attending movies/art exhibitions, were found to be significantly associated with child health status after controlling for other risk factors. The quality of water, the quality of local health services and maternal education were also significantly associated with child health status. Household income, child gender and household dampness had no significant association with child health status in this context. Maternal cultural participation was a significant predictor of child health status in impoverished urban communities. Improving child health through culturally focused interventions for mothers, especially in deprived areas, may be greatly important.

Effect of altering starting length and activation timing of muscle on fiber strain and muscle damage.

PubMed

Butterfield, Timothy A; Herzog, Walter

2006-05-01

Muscle strain injuries are some of the most frequent injuries in sports and command a great deal of attention in an effort to understand their etiology. These injuries may be the culmination of a series of subcellular events accumulated through repetitive lengthening (eccentric) contractions during exercise, and they may be influenced by a variety of variables including fiber strain magnitude, peak joint torque, and starting muscle length. To assess the influence of these variables on muscle injury magnitude in vivo, we measured fiber dynamics and joint torque production during repeated stretch-shortening cycles in the rabbit tibialis anterior muscle, at short and long muscle lengths, while varying the timing of activation before muscle stretch. We found that a muscle subjected to repeated stretch-shortening cycles of constant muscle-tendon unit excursion exhibits significantly different joint torque and fiber strains when the timing of activation or starting muscle length is changed. In particular, measures of fiber strain and muscle injury were significantly increased by altering activation timing and increasing the starting length of the muscle. However, we observed differential effects on peak joint torque during the cyclic stretch-shortening exercise, as increasing the starting length of the muscle did not increase torque production. We conclude that altering activation timing and muscle length before stretch may influence muscle injury by significantly increasing fiber strain magnitude and that fiber dynamics is a more important variable than muscle-tendon unit dynamics and torque production in influencing the magnitude of muscle injury.

Dynamical Imaging with Interferometry

NASA Astrophysics Data System (ADS)

Johnson, Michael D.; Bouman, Katherine L.; Blackburn, Lindy; Chael, Andrew A.; Rosen, Julian; Shiokawa, Hotaka; Roelofs, Freek; Akiyama, Kazunori; Fish, Vincent L.; Doeleman, Sheperd S.

2017-12-01

By linking widely separated radio dishes, the technique of very long baseline interferometry (VLBI) can greatly enhance angular resolution in radio astronomy. However, at any given moment, a VLBI array only sparsely samples the information necessary to form an image. Conventional imaging techniques partially overcome this limitation by making the assumption that the observed cosmic source structure does not evolve over the duration of an observation, which enables VLBI networks to accumulate information as Earth rotates and changes the projected array geometry. Although this assumption is appropriate for nearly all VLBI, it is almost certainly violated for submillimeter observations of the Galactic center supermassive black hole, Sagittarius A* (Sgr A*), which has a gravitational timescale of only ∼ 20 s and exhibits intrahour variability. To address this challenge, we develop several techniques to reconstruct dynamical images (“movies”) from interferometric data. Our techniques are applicable to both single-epoch and multiepoch variability studies, and they are suitable for exploring many different physical processes including flaring regions, stable images with small time-dependent perturbations, steady accretion dynamics, or kinematics of relativistic jets. Moreover, dynamical imaging can be used to estimate time-averaged images from time-variable data, eliminating many spurious image artifacts that arise when using standard imaging methods. We demonstrate the effectiveness of our techniques using synthetic observations of simulated black hole systems and 7 mm Very Long Baseline Array observations of M87, and we show that dynamical imaging is feasible for Event Horizon Telescope observations of Sgr A*.

Adsorption and redox reactions of heavy metals on synthesized Mn oxide minerals.

PubMed

Feng, Xiong Han; Zhai, Li Mei; Tan, Wen Feng; Liu, Fan; He, Ji Zheng

2007-05-01

Several Mn oxide minerals commonly occurring in soils were synthesized by modified or optimized methods. The morphologies, structures, compositions and surface properties of the synthesized Mn oxide minerals were characterized. Adsorption and redox reactions of heavy metals on these minerals in relation to the mineral structures and surface properties were also investigated. The synthesized birnessite, todorokite, cryptomelane, and hausmannite were single-phased minerals and had the typical morphologies from analyses of XRD and TEM/ED. The PZCs of the synthesized birnessite, todorokite and cryptomelane were 1.75, 3.50 and 2.10, respectively. The magnitude order of their surface variable negative charge was: birnessite> or =cryptomelane>todorokite. The hausmannite had a much higher PZC than others with the least surface variable negative charge. Birnessite exhibited the largest adsorption capacity on heavy metals Pb(2+), Cu(2+), Co(2+), Cd(2+) and Zn(2+), while hausmannite the smallest one. Birnessite, cryptomelane and todorokite showed the greatest adsorption capacity on Pb(2+) among the tested heavy metals. Hydration tendency (pK(1)) of the heavy metals and the surface variable charge of the Mn minerals had significant impacts on the adsorption. The ability in Cr(III) oxidation and concomitant release of Mn(2+) varied greatly depending on the structure, composition, surface properties and crystallinity of the minerals. The maximum amounts of Cr(III) oxidized by the Mn oxide minerals in order were (mmol/kg): birnessite (1330.0)>cryptomelane (422.6)>todorokite (59.7)>hausmannite (36.6).

Effects of Physiochemical Factors on Prokaryotic Biodiversity in Malaysian Circumneutral Hot Springs

PubMed Central

Chan, Chia S.; Chan, Kok-Gan; Ee, Robson; Hong, Kar-Wai; Urbieta, María S.; Donati, Edgardo R.; Shamsir, Mohd S.; Goh, Kian M.

2017-01-01

Malaysia has a great number of hot springs, especially along the flank of the Banjaran Titiwangsa mountain range. Biological studies of the Malaysian hot springs are rare because of the lack of comprehensive information on their microbial communities. In this study, we report a cultivation-independent census to describe microbial communities in six hot springs. The Ulu Slim (US), Sungai Klah (SK), Dusun Tua (DT), Sungai Serai (SS), Semenyih (SE), and Ayer Hangat (AH) hot springs exhibit circumneutral pH with temperatures ranging from 43°C to 90°C. Genomic DNA was extracted from environmental samples and the V3–V4 hypervariable regions of 16S rRNA genes were amplified, sequenced, and analyzed. High-throughput sequencing analysis showed that microbial richness was high in all samples as indicated by the detection of 6,334–26,244 operational taxonomy units. In total, 59, 61, 72, 73, 65, and 52 bacterial phyla were identified in the US, SK, DT, SS, SE, and AH hot springs, respectively. Generally, Firmicutes and Proteobacteria dominated the bacterial communities in all hot springs. Archaeal communities mainly consisted of Crenarchaeota, Euryarchaeota, and Parvarchaeota. In beta diversity analysis, the hot spring microbial memberships were clustered primarily on the basis of temperature and salinity. Canonical correlation analysis to assess the relationship between the microbial communities and physicochemical variables revealed that diversity patterns were best explained by a combination of physicochemical variables, rather than by individual abiotic variables such as temperature and salinity. PMID:28729863

An Expanded Rossi X-Ray Timing Explorer Survey of X-Ray Variability in Seyfert 1 Galaxies

NASA Astrophysics Data System (ADS)

Markowitz, A.; Edelson, R.

2004-12-01

The first seven years of RXTE monitoring of Seyfert 1 active galactic nuclei have been systematically analyzed to yield five homogeneous samples of 2-12 keV light curves, probing hard X-ray variability on successively longer durations from ~1 day to ~3.5 yr. The 2-10 keV variability on timescales of ~1 day, as probed by ASCA, is included. All sources exhibit stronger X-ray variability toward longer timescales, but the increase is greater for relatively higher luminosity sources. Variability amplitudes are anticorrelated with X-ray luminosity and black hole mass, but amplitudes saturate and become independent of luminosity or black hole mass toward the longest timescales. The data are consistent with the models of power spectral density (PSD) movement described by Markowitz and coworkers and McHardy and coworkers, whereby Seyfert 1 galaxies' variability can be described by a single, universal PSD shape whose break frequency scales with black hole mass. The best-fitting scaling relations between variability timescale, black hole mass, and X-ray luminosity imply an average accretion rate of ~5% of the Eddington limit for the sample. Nearly all sources exhibit stronger variability in the relatively soft 2-4 keV band compared to the 7-12 keV band on all timescales. There are indications that relatively less luminous or less massive sources exhibit a greater degree of spectral variability for a given increase in overall flux.

Prevalence of low back pain in children and adolescents: a meta-analysis

PubMed Central

2013-01-01

Background Low back pain (LBP) is common in children and adolescents, and it is becoming a public health concern. In recent years there has been a considerable increase in research studies that examine the prevalence of LBP in this population, but studies exhibit great variability in the prevalence rates reported. The purpose of this research was to examine, by means of a meta-analytic investigation, the prevalence rates of LBP in children and adolescents. Methods Studies were located from computerized databases (ISI Web of Knowledge, MedLine, PEDro, IME, LILACS, and CINAHL) and other sources. The search period extended to April 2011. To be included in the meta-analysis, studies had to report a prevalence rate (whether point, period or lifetime prevalence) of LBP in children and/or adolescents (≤ 18 years old). Two independent researchers coded the moderator variables of the studies, and extracted the prevalence rates. Separate meta-analyses were carried out for the different types of prevalence in order to avoid dependence problems. In each meta-analysis, a random-effects model was assumed to carry out the statistical analyses. Results A total of 59 articles fulfilled the selection criteria. The mean point prevalence obtained from 10 studies was 0.120 (95% CI: 0.09 and 0.159). The mean period prevalence at 12 months obtained from 13 studies was 0.336 (95% CI: 0.269 and 0.410), whereas the mean period prevalence at one week obtained from six studies was 0.177 (95% CI: 0.124 and 0.247). The mean lifetime prevalence obtained from 30 studies was 0.399 (95% CI: 0.342 and 0.459). Lifetime prevalence exhibited a positive, statistically significant relationship with the mean age of the participants in the samples and with the publication year of the studies. Conclusions The most recent studies showed higher prevalence rates than the oldest ones, and studies with a better methodology exhibited higher lifetime prevalence rates than studies that were methodologically poor. Future studies should report more information regarding the definition of LBP and there is a need to improve the methodological quality of studies. PMID:23351394

Geographical and ethnic variability of finger ridge-counts: biplots of male and female Indian samples.

PubMed

Krishnan, T; Reddy, B M

1994-01-01

The graphical technique of biplot due to Gabriel and others is explained, and is applied to ten finger ridge-count means of 239 populations, mostly Indian. The biplots, together with concentration ellipses based on them, are used to study geographical, gender and ethnic/social group variability, to compare Indian populations with other populations and to study relations between individual counts and populations. The correlation structure of ridge-counts exhibits a tripartite division of digits demonstrated by many other studies, but with a somewhat different combination of digits. Comparisons are also made with the results of Leguebe and Vrydagh, who used principal components, discriminant functions, Andrews functions, etc., to study geographical and gender variations. There is a great deal of homogeneity in Indian populations when compared to populations from the rest of the world. Although broad geographical contiguity is reflected in the biplots, local (states within India) level contiguity is not maintained. Monogoloids and Caucasoids have distinct ridge-count structures. The higher level of homogeneity in females and on the left side observed by Leguebe and Vrydagh is also observed in the biplots. A comparison with principal component plots indicates that biplots yield a graphical representation similar to component plots, and convey more information than component plots.

Squeezing of particle distributions by expanding magnetic turbulence and space weather variability

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

Ruffolo, D.; Seripienlert, A.; Tooprakai, P.

Among the space weather effects due to gradual solar storms, greatly enhanced high-energy ion fluxes contribute to radiation damage to satellites, spacecraft, and astronauts and dominate the hazards to air travelers, which motivates examination of the transport of high-energy solar ions to Earth's orbit. Ions of low kinetic energy (up to ∼2 MeV nucleon{sup –1}) from impulsive solar events exhibit abrupt changes due to filamentation of the magnetic connection from the Sun, indicating that anisotropic, field-aligned magnetic flux tubelike structures persist to Earth's orbit. By employing a corresponding spherical two-component model of Alfvénic (slab) and two-dimensional magnetic fluctuations to tracemore » simulated trajectories in the solar wind, we show that the distribution of high-energy (E ≥ 1 GeV) protons from gradual solar events is squeezed toward magnetic flux structures with a specific polarity because of the conical shape of the flux structures. Conical flux structures and the squeezing of energetic particle distributions should occur in any astrophysical wind or jet with expanding, magnetized, turbulent plasma. This transport phenomenon contributes to event-to-event variability in ground level enhancements of GeV-range ions from solar storms, presenting a fundamental uncertainty in space weather prediction.« less

Natural selection reduced diversity on human y chromosomes.

PubMed

Wilson Sayres, Melissa A; Lohmueller, Kirk E; Nielsen, Rasmus

2014-01-01

The human Y chromosome exhibits surprisingly low levels of genetic diversity. This could result from neutral processes if the effective population size of males is reduced relative to females due to a higher variance in the number of offspring from males than from females. Alternatively, selection acting on new mutations, and affecting linked neutral sites, could reduce variability on the Y chromosome. Here, using genome-wide analyses of X, Y, autosomal and mitochondrial DNA, in combination with extensive population genetic simulations, we show that low observed Y chromosome variability is not consistent with a purely neutral model. Instead, we show that models of purifying selection are consistent with observed Y diversity. Further, the number of sites estimated to be under purifying selection greatly exceeds the number of Y-linked coding sites, suggesting the importance of the highly repetitive ampliconic regions. While we show that purifying selection removing deleterious mutations can explain the low diversity on the Y chromosome, we cannot exclude the possibility that positive selection acting on beneficial mutations could have also reduced diversity in linked neutral regions, and may have contributed to lowering human Y chromosome diversity. Because the functional significance of the ampliconic regions is poorly understood, our findings should motivate future research in this area.

Natural Selection Reduced Diversity on Human Y Chromosomes

PubMed Central

Wilson Sayres, Melissa A.; Lohmueller, Kirk E.; Nielsen, Rasmus

2014-01-01

The human Y chromosome exhibits surprisingly low levels of genetic diversity. This could result from neutral processes if the effective population size of males is reduced relative to females due to a higher variance in the number of offspring from males than from females. Alternatively, selection acting on new mutations, and affecting linked neutral sites, could reduce variability on the Y chromosome. Here, using genome-wide analyses of X, Y, autosomal and mitochondrial DNA, in combination with extensive population genetic simulations, we show that low observed Y chromosome variability is not consistent with a purely neutral model. Instead, we show that models of purifying selection are consistent with observed Y diversity. Further, the number of sites estimated to be under purifying selection greatly exceeds the number of Y-linked coding sites, suggesting the importance of the highly repetitive ampliconic regions. While we show that purifying selection removing deleterious mutations can explain the low diversity on the Y chromosome, we cannot exclude the possibility that positive selection acting on beneficial mutations could have also reduced diversity in linked neutral regions, and may have contributed to lowering human Y chromosome diversity. Because the functional significance of the ampliconic regions is poorly understood, our findings should motivate future research in this area. PMID:24415951

Constraints on ocean carbonate chemistry and pCO2 in the Archaean and Palaeoproterozoic

NASA Astrophysics Data System (ADS)

Blättler, C. L.; Kump, L. R.; Fischer, W. W.; Paris, G.; Kasbohm, J. J.; Higgins, J. A.

2017-01-01

One of the great problems in the history of Earth’s climate is how to reconcile evidence for liquid water and habitable climates on early Earth with the Faint Young Sun predicted from stellar evolution models. Possible solutions include a wide range of atmospheric and oceanic chemistries, with large uncertainties in boundary conditions for the evolution and diversification of life and the role of the global carbon cycle in maintaining habitable climates. Increased atmospheric CO2 is a common component of many solutions, but its connection to the carbon chemistry of the ocean remains unknown. Here we present calcium isotope data spanning the period from 2.7 to 1.9 billion years ago from evaporitic sedimentary carbonates that can test this relationship. These data, from the Tumbiana Formation, the Campbellrand Platform and the Pethei Group, exhibit limited variability. Such limited variability occurs in marine environments with a high ratio of calcium to carbonate alkalinity. We are therefore able to rule out soda ocean conditions during this period of Earth history. We further interpret this and existing data to provide empirical constraints for carbonate chemistry of the ancient oceans and for the role of CO2 in compensating for the Faint Young Sun.

Frontal theta activation during motor synchronization in autism.

PubMed

Kawasaki, Masahiro; Kitajo, Keiichi; Fukao, Kenjiro; Murai, Toshiya; Yamaguchi, Yoko; Funabiki, Yasuko

2017-11-08

Autism is characterized by two primary characteristics: deficits in social interaction and repetitive behavioral patterns. Because interpersonal communication is extremely complicated, its underlying brain mechanisms remain unclear. Here we showed that both characteristics can be explained by a unifying underlying mechanism related to difficulties with irregularities. To address the issues, we measured electroencephalographm during a cooperative tapping task, which required participants to tap a key alternately and synchronously with constant rhythmic a PC program, a variable rhythmic PC program, or a human partner. We found that people with autism had great difficulty synchronizing tapping behavior with others, and exhibited greater than normal theta-wave (6 Hz) activity in the frontal cortex during the task, especially when their partner behaved somewhat irregularly (i.e. a variable rhythmic PC program or a human partner). Importantly, the higher theta-wave activity was related to the severity of autism, not the performance on the task. This indicates that people with autism need to use intense cognition when trying to adapt to irregular behavior and can easily become overtaxed. Difficulty adapting to irregular behavior in others is likely related to their own tendencies for repetitive and regular behaviors. Thus, while the two characteristics of autism have been comprehended separately, our unifying theory makes understanding the condition and developing therapeutic strategies more tractable.

A colloidal assembly approach to synthesize magnetic porous composite nanoclusters for efficient protein adsorption

NASA Astrophysics Data System (ADS)

Yang, Qi; Lan, Fang; Yi, Qiangying; Wu, Yao; Gu, Zhongwei

2015-10-01

A combination strategy of the inverse emulsion crosslinking approach and the colloidal assembly technique is first proposed to synthesize Fe3O4/histidine composite nanoclusters as new-type magnetic porous nanomaterials. The nanoclusters possess uniform morphology, high magnetic content and excellent protein adsorption capacity, exhibiting their great potential for bio-separation.A combination strategy of the inverse emulsion crosslinking approach and the colloidal assembly technique is first proposed to synthesize Fe3O4/histidine composite nanoclusters as new-type magnetic porous nanomaterials. The nanoclusters possess uniform morphology, high magnetic content and excellent protein adsorption capacity, exhibiting their great potential for bio-separation. Electronic supplementary information (ESI) available: Experimental details. See DOI: 10.1039/c5nr05800g

Factors affecting the evolution of coastal wetlands of the Laurentian Great Lakes: An overview

USGS Publications Warehouse

Mayer, T.; Edsall, T.; Munawar, M.

2004-01-01

Coastal wetlands play a pivotal role in the Great Lakes ecosystem. As buffer zones between the land and open waters of the Great Lakes, they perform a variety of essential functions providing both direct and indirect anthropogenic benefits. Geology, morphology and climate are the dominant variables that influence Laurentian Great Lakes wetland development. However, anthropogenic factors are the major contributors to alteration of natural wetland processes. This paper provides an overview of natural and anthropogenic factors important in Great Lakes coastal wetland development and provides statistical information describing the Great Lakes Basin. A brief description of wetlands classification and research issues is also presented.

Interesting examples of supervised continuous variable systems

NASA Technical Reports Server (NTRS)

Chase, Christopher; Serrano, Joe; Ramadge, Peter

1990-01-01

The authors analyze two simple deterministic flow models for multiple buffer servers which are examples of the supervision of continuous variable systems by a discrete controller. These systems exhibit what may be regarded as the two extremes of complexity of the closed loop behavior: one is eventually periodic, the other is chaotic. The first example exhibits chaotic behavior that could be characterized statistically. The dual system, the switched server system, exhibits very predictable behavior, which is modeled by a finite state automaton. This research has application to multimodal discrete time systems where the controller can choose from a set of transition maps to implement.

Moscow City Telephone Network

DTIC Science & Technology

1976-12-23

of sounds over long distances, which he called the telephone, at an exhibition in...Philadelphia. This demonstration of the operation of the telephone was viewed with great interest by visitors at the exhibition . All who saw it were... of the telephones may inspect them at the Central Telephone Exchange from 2 to 4 o’clock. Operation of the telephone system will definitely begin

Temporal factors in the extinction of fear in inbred mouse strains differing in extinction efficacy

PubMed Central

2013-01-01

Background Various neuropsychiatric conditions, including posttraumatic stress disorder (PTSD), are characterized by deficient fear extinction, but individuals differ greatly in risk for these. While there is growing evidence that fear extinction is influenced by certain procedural variables, it is unclear how these influences might vary across individuals and subpopulations. To model individual differences in fear extinction, prior studies identified a strain of inbred mouse, 129S1/SvImJ (S1), which exhibits a profound deficit in fear extinction, as compared to other inbred strains, such as C57BL/6J (B6). Methods Here, we assessed the effects of procedural variables on the impaired extinction phenotype of the S1 strain and, by comparison, the extinction-intact B6 strain. The variables studied were 1) the interval between conditioning and extinction, 2) the interval between cues during extinction training, 3) single-cue exposure before extinction training, and 4) extinction of a second-order conditioned cue. Results Conducting extinction training soon after (‘immediately’) conditioning attenuated fear retrieval in S1 mice and impaired extinction in B6 mice. Spacing cue presentations with long inter-trial intervals during extinction training augmented fear in S1 and B6 mice. The effect of spacing was lost with one-trial fear conditioning in B6, but not S1 mice. A single exposure to a conditioned cue before extinction training did not alter extinction retrieval, either in B6 or S1 mice. Both the S1 and B6 strains exhibited robust second-order fear conditioning, in which a cue associated with footshock was sufficient to serve as a conditioned exciter to condition a fear association to a second cue. B6 mice extinguished the fear response to the second-order conditioned cue, but S1 mice failed to do so. Conclusions These data provide further evidence that fear extinction is strongly influenced by multiple procedural variables and is so in a highly strain-dependent manner. This suggests that the efficacy of extinction-based behavioral interventions, such as exposure therapy, for trauma-related anxiety disorders will be determined by the procedural parameters employed and the degree to which the patient can extinguish. PMID:23830244

A New Variable Weighting and Selection Procedure for K-Means Cluster Analysis

ERIC Educational Resources Information Center

Steinley, Douglas; Brusco, Michael J.

2008-01-01

A variance-to-range ratio variable weighting procedure is proposed. We show how this weighting method is theoretically grounded in the inherent variability found in data exhibiting cluster structure. In addition, a variable selection procedure is proposed to operate in conjunction with the variable weighting technique. The performances of these…

Diagnostics of wear in aeronautical systems

NASA Technical Reports Server (NTRS)

Wedeven, L. D.

1979-01-01

Maintenance costs associated with the transmissions and drive train greatly increase the maintenance burden and failure risk. Detection measurements fall under two general categories of vibration and particle detectors. The latter are more amenable to tracking wear. Wear debris analysis can supply a great deal of information such as: particle concentration, rate of change in concentration, composition, particle size and shape, principal metals, etc. It is not economically feasible to monitor all variables. At least one role of the lubrication and wear specialist is to provide guidance in selecting the most appropriate variables to monitor.

Influence of spatial and temporal variability of subsurface soil moisture and temperature on vapour intrusion

NASA Astrophysics Data System (ADS)

Bekele, Dawit N.; Naidu, Ravi; Chadalavada, Sreenivasulu

2014-05-01

A comprehensive field study was conducted at a site contaminated with chlorinated solvents, mainly trichloroethylene (TCE), to investigate the influence of subsurface soil moisture and temperature on vapour intrusion (VI) into built structures. Existing approaches to predict the risk of VI intrusion into buildings assume homogeneous or discrete layers in the vadose zone through which TCE migrates from an underlying source zone. In reality, the subsurface of the majority of contaminated sites will be subject to significant variations in moisture and temperature. Detailed site-specific data were measured contemporaneously to evaluate the impact of spatial and temporal variability of subsurface soil properties on VI exposure assessment. The results revealed that indoor air vapour concentrations would be affected by spatial and temporal variability of subsurface soil moisture and temperature. The monthly monitoring of soil-gas concentrations over a period of one year at a depth of 3 m across the study site demonstrated significant variation in TCE vapour concentrations, which ranged from 480 to 629,308 μg/m3. Soil-gas wells at 1 m depth exhibited high seasonal variability in TCE vapour concentrations with a coefficient of variation 1.02 in comparison with values of 0.88 and 0.74 in 2 m and 3 m wells, respectively. Contour plots of the soil-gas TCE plume during wet and dry seasons showed that the plume moved across the site, hence locations of soil-gas monitoring wells for human risk assessment is a site specific decision. Subsurface soil-gas vapour plume characterisation at the study site demonstrates that assessment for VI is greatly influenced by subsurface soil properties such as temperature and moisture that fluctuate with the seasons of the year.

An assessment of campsite conditions in Great Smoky Mountains National Park

USGS Publications Warehouse

Marion, J.L.; Leung, Y-L

1997-01-01

This research effort designed and implemented a backcountry campsite monitoring program for Great Smoky Mountains National Park (GSMNP). This report reviews the need for visitor impact monitoring programs, describes monitoring procedures developed and applied at GSMNP, presents results from the first monitoring cycle, evaluates current park camping management policies, and provides recommendations for reducing campingrelated visitor impacts. Field staff assessed 377 campsites at 82 designated backcountry campgrounds, and all 18 shelters. Campgrounds are frequently bisected by park trails and more than half (188, 58%) of legal campsites are within 100 feet of a park trail. High campsite intervisibility diminishes the potential for solitude; 79% of the campsites have at least one other site visible, 26% have three or more other sites visible. Campsite conditions are quite variable, with some campgrounds exhibiting generally good conditions while others are exceptionally large, with substantial vegetation loss, soil exposure, and damage to trees. Evaluations of campsite condition data reveal a number of potential problems, most notably: 1) campsite proliferation, 2) campsite expansion and excessive size, 3) excessive vegetation loss and soil exposure, 4) excessive campfire-related degradation, and 5) low visitor solitude at campsites. Data are used to characterize these problems and evaluate influential relationships and contributing causes. Recreation ecology findings from other studies are considered in evaluating alternative management responses. Park backcountry management policies are also reviewed and recommendations are offered for management consideration.

An Expanded RXTE Survey of Long-Term X-ray Variability in Seyfert 1 Galaxies

NASA Technical Reports Server (NTRS)

Markowitz, A.; Edelson, R.

2004-01-01

The first seven years of RXTE monitoring of Seyfert 1 active galactic nuclei have been systematically analyzed to yield five homogenous samples of 2-12 keV light curves, probing hard X-ray variability on successively longer durations from approx. 1 day to approx. 3.5 years. 2-10 keV variability on time scales of approx. 1 day, as probed by ASCA, are included. All sources exhibit stronger X-ray variability towards longer time scales, with variability amplitudes saturating at the longest time scales, but the increase is greater for relatively higher luminosity sources. The well-documented anticorrelation between variability amplitude and luminosity is confirmed on all time scales. However, anticorrelations between variability amplitude and black hole mass estimate are evident on only the shortest time scales probed. The data are consistent with the models of power spectral density (PSD) movement described in Markowitz et al. (2003) and McHardy et al. (2004), whereby Seyfert 1 galaxies variability can be described by a single, universal PSD shape whose cutoff frequency scales with black hole mass. The best-fitting scaling relations between variability time scale, black hole mass and X-ray luminosity support an average accretion rate of 2% of the Eddington limit for the sample. Nearly all sources exhibit stronger variability in the relatively soft 2-4 keV band compared to the 7-12 keV band on all time scales. Color-flux diagrams support also Seyfert 1s' softening as they brighten. There are indications that relatively less luminous or less massive sources exhibit a greater degree of spectral variability for a given increase in overall flux.

Personal and Contextual Influences on Township School Learners' Motivation and Self-Regulated Learning

ERIC Educational Resources Information Center

Geduld, Bernadette

2017-01-01

Learners' self-regulation, which includes motivational variables, is influenced by personal variables within learners themselves, as well as by contextual factors. A great deal of research has focused on personal variables in learners that influence their self-regulated behaviours; yet contextual influences that operate outside of formal schooling…

cHRV Uncovering Daily Stress Dynamics Using Bio-Signal from Consumer Wearables.

PubMed

Hao, Tian; Chang, Henry; Ball, Marion; Lin, Kun; Zhu, Xinxin

2017-01-01

Knowing the dynamics of one's daily stress is essential to effective stress management in the context of smart and connected health. However, there lacks a practical and unobtrusive means to obtain real-time and longitudinal stress information. In this paper, we attempt to derive a convenient HRV-based (heart rate variability) biomarker named cHRV, which can be used to reliably reflect stress dynamics. cHRV's key advantage lies in its low maintenance and high practicality. It can be efficiently calculated only using data from photoplethysmography (PPG) sensors, the mainstream heart rate sensor embedded in most of the consumer wearables like Apple Watch. Benefiting from the proliferation of wearables, cHRV is ideal for day-to-day stress monitoring. To evaluate its feasibility and performance, we have conducted 14 in-lab controlled experiments. The result shows that the proposed cHRV has strong correlation with the stress dynamics (r > 0.95), therefore exhibits great potential for continuous stress assessment.

Research on Design of Tri-color Shift Device

NASA Astrophysics Data System (ADS)

Xu, Ping; Yuan, Xia; Huang, Haixuan; Yang, Tuo; Huang, Yanyan; Zhu, Tengfei; Tang, Shaotuo; Peng, Wenda

2016-11-01

An azimuth-tuned tri-color shift device based on an embedded subwavelength one-dimensional rectangular structure with single period is proposed. High reflection efficiencies for both TE and TM polarizations can be achieved simultaneously. Under an oblique incidence of 60°, the reflection efficiencies can reach up to 85, 86, and 100 % in blue (azimuth of 24°), green (azimuth of 63°), and red (azimuth of 90°) waveband, respectively. Furthermore, the laws of influence of device period, groove depth, coating thickness, and incident angle on reflection characteristics are investigated and exposed, and feasibility of the device is demonstrated. The proposed device realizes tri-color shift for natural light using a simple structure. It exhibits high efficiency as well as good security. Such a device can be fabricated by the existing embossing and coating technique. All these break through the limit of bi-color shift anti-counterfeiting technology and have great applications in the field of optically variable image security.

New Insights Into the Mechanisms and Biological Roles of D-Amino Acids in Complex Eco-Systems

PubMed Central

Aliashkevich, Alena; Alvarez, Laura; Cava, Felipe

2018-01-01

In the environment bacteria share their habitat with a great diversity of organisms, from microbes to humans, animals and plants. In these complex communities, the production of extracellular effectors is a common strategy to control the biodiversity by interfering with the growth and/or viability of nearby microbes. One of such effectors relies on the production and release of extracellular D-amino acids which regulate diverse cellular processes such as cell wall biogenesis, biofilm integrity, and spore germination. Non-canonical D-amino acids are mainly produced by broad spectrum racemases (Bsr). Bsr’s promiscuity allows it to generate high concentrations of D-amino acids in environments with variable compositions of L-amino acids. However, it was not clear until recent whether these molecules exhibit divergent functions. Here we review the distinctive biological roles of D-amino acids, their mechanisms of action and their modulatory properties of the biodiversity of complex eco-systems. PMID:29681896

Recruitment patterns and growth of high-elevation pines in response to climatic variability (1883–2013), in the western Great Basin, USA

Treesearch

Constance I. Millar; Robert D. Westfall; Diane L. Delany; Alan L. Flint; Lorraine E. Flint

2015-01-01

Over the period 1883–2013, recruitment of subalpine limber pine (Pinus flexilis E. James) and Great Basin bristlecone pine (Pinus longaeva D.K. Bailey) above the upper tree line, below the lower tree line, and across middle-elevation forest borders occurred at localized sites across four mountain ranges in the western Great...

Variable Pitch Propellers

NASA Technical Reports Server (NTRS)

1920-01-01

In this report are described four different types of propellers which appeared at widely separated dates, but which were exhibited together at the last Salon de l'Aeronautique. The four propellers are the Chaviere variable pitch propeller, the variable pitch propeller used on the Clement Bayard dirigible, the variable pitch propeller used on Italian dirigibles, and the Levasseur variable pitch propeller.

Prevalence of an unusual hypoplastic defect of the permanent maxillary lateral incisor in great apes.

PubMed

Hannibal, Darcy L

2017-02-01

In this article, I describe a previously unreported maxillary lateral incisor defect (MLID) of the enamel in great apes and evaluate potential general causes (genetic, systemic stress, or localized disturbance), as well as examine differences in prevalence among the represented taxa. This defect occurred only on the labial surface of the maxillary lateral incisor and extended from the cervical-mesial quarter of the crown to the mesial edge of the cementoenamel junction (CEJ). The study sample consisted of 136 great ape specimens, including 41 gorillas, 25 chimpanzees, and 70 orangutans from the Smithsonian's National Museum of Natural History great ape collection. I used logistic regression to assess the prevalence of this defect in the sample and a binomial probability test for bilaterality. This defect of the maxillary lateral incisor is the second most common defect I observed in the study sample (30.1% of individuals affected), and was more likely to occur in individuals with linear enamel hypoplasia (LEH) and pit defects than those without these defects. Among specimens with both maxillary lateral incisors present, the defect was mostly bilateral. Pan and Pongo were significantly more likely to exhibit the defect than Gorilla. Between Pongo species, Pongo pygmaeus was significantly more likely to exhibit the defect than Pongo abelii. Between subspecies of Gorilla, although Gorilla gorilla gorilla exhibited the defect and Gorilla gorilla beringei did not, the difference was not significant. No sex differences were evident in this sample. The prevalence of this defect indicates it is not hereditary. The bilateral trend indicates a systemic cause, although the high inter-tooth specificity suggests a local disturbance and a combination of both is possible. © 2016 Wiley Periodicals, Inc.

Humidity: A review and primer on atmospheric moisture and human health.

PubMed

Davis, Robert E; McGregor, Glenn R; Enfield, Kyle B

2016-01-01

Research examining associations between weather and human health frequently includes the effects of atmospheric humidity. A large number of humidity variables have been developed for numerous purposes, but little guidance is available to health researchers regarding appropriate variable selection. We examine a suite of commonly used humidity variables and summarize both the medical and biometeorological literature on associations between humidity and human health. As an example of the importance of humidity variable selection, we correlate numerous hourly humidity variables to daily respiratory syncytial virus isolates in Singapore from 1992 to 1994. Most water-vapor mass based variables (specific humidity, absolute humidity, mixing ratio, dewpoint temperature, vapor pressure) exhibit comparable correlations. Variables that include a thermal component (relative humidity, dewpoint depression, saturation vapor pressure) exhibit strong diurnality and seasonality. Humidity variable selection must be dictated by the underlying research question. Despite being the most commonly used humidity variable, relative humidity should be used sparingly and avoided in cases when the proximity to saturation is not medically relevant. Care must be taken in averaging certain humidity variables daily or seasonally to avoid statistical biasing associated with variables that are inherently diurnal through their relationship to temperature. Copyright © 2015 Elsevier Inc. All rights reserved.

How can we turn a science exhibition on a really success outreach activity?

NASA Astrophysics Data System (ADS)

Farrona, A. M. M.; Vilar, R.

2016-04-01

In April 2013, a CERN exhibition was shown in Santander: ;The largest scientific instrument ever built;. Around the exhibition, were proposed several activities: guide tours for children, younger and adults, workshops, film projections… In this way, the exhibition was visited by more than two thousand persons. We must keep in mind that Santander is a small city and it population does not usually take part in outreach activity. With this contribution, we want to teach the way in which it is possible to take advantage of science exhibitions. It made possible to show the Large Hadron Collider at CERN experiment to the great majority of Santander population, and to awaken their interest in or enthusiasm for science.

Gardening guide for high-desert urban landscapes of Great Basin regions in Nevada and Utah

Treesearch

Heidi Kratsch; Rick Heflebower

2013-01-01

Some Great Basin urban areas in Utah and Nevada exhibit climatic conditions that make it difficult for all but the toughest landscape plants to thrive without providing supplemental water. These areas are found at elevations from 4,000 feet to 6,000 feet in USDA cold-hardiness zones 6 and 7. Soils are often poor and gravelly, containing less than 1 percent organic...

Variability in physical and biological exchange among coastal wetlands and their adjacent Great Lakes

EPA Science Inventory

Hydrology is a major governor of physically-driven exchange among coastal wetlands and the adjacent Great Lake, whereas fish movement is a major governor of biologically-driven exchange. We use data describing coastal wetland morphology, hydrology, water quality, and fish tissue...

Nonsteroidal Anti-inflammatory Drugs (NSAIDS) Inhibit the Growth and Reproduction of Chaetomium globosum and Other Fungi Associated with Water-Damaged Buildings.

PubMed

Dalmont, Kelsey; Biles, Charles L; Konsure, Heather; Dahal, Sujita; Rowsey, Tyler; Broge, Matthew; Poudyal, Shubhra; Gurung, Tara; Shrestha, Sabina; Biles, Caleb L; Cluck, Terry; Howard, Alisha

2017-12-01

Indoor mold due to water damage causes serious human respiratory disorders, and the remediation to homes, schools, and businesses is a major expense. Prevention of mold infestation of building materials would reduce health problems and building remediation costs. Nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit yeasts and a limited number of filamentous fungi. The purpose of this research was to determine the possible inhibitory activity of nonsteroidal anti-inflammatory drugs (NSAIDs) on germination, fungal growth, and reproduction of Chaetomium globosum and other important filamentous fungi that occur in water-damaged buildings. Several NSAIDs were found to inhibit C. globosum germination, growth, and reproduction. The most effective NSAIDs inhibiting C. globosum were ibuprofen, diflunisal, and diclofenac. Fusarium oxysporum, Fusarium solani, Aspergillus niger, and Stachybotrys atra were also tested on the various media with similar results obtained. However, F. oxysporum and A. niger exhibited a higher level of resistance to aspirin and NaSAL when compared to the C. globosum isolates. The inhibition exhibited by NSAIDs was variable depending on growth media and stage of fungal development. These compounds have a great potential of inhibiting fungal growth on building materials such as gypsum board. Formulations of sprays or building materials with NSAID-like chemical treatments may hold promise in reducing mold in homes and buildings.

Selection of Variables in Cluster Analysis: An Empirical Comparison of Eight Procedures

ERIC Educational Resources Information Center

Steinley, Douglas; Brusco, Michael J.

2008-01-01

Eight different variable selection techniques for model-based and non-model-based clustering are evaluated across a wide range of cluster structures. It is shown that several methods have difficulties when non-informative variables (i.e., random noise) are included in the model. Furthermore, the distribution of the random noise greatly impacts the…

One- and Two-dimensional Solitary Wave States in the Nonlinear Kramers Equation with Movement Direction as a Variable

NASA Astrophysics Data System (ADS)

Sakaguchi, Hidetsugu; Ishibashi, Kazuya

2018-06-01

We study self-propelled particles by direct numerical simulation of the nonlinear Kramers equation for self-propelled particles. In our previous paper, we studied self-propelled particles with velocity variables in one dimension. In this paper, we consider another model in which each particle exhibits directional motion. The movement direction is expressed with a variable ϕ. We show that one-dimensional solitary wave states appear in direct numerical simulations of the nonlinear Kramers equation in one- and two-dimensional systems, which is a generalization of our previous result. Furthermore, we find two-dimensionally localized states in the case that each self-propelled particle exhibits rotational motion. The center of mass of the two-dimensionally localized state exhibits circular motion, which implies collective rotating motion. Finally, we consider a simple one-dimensional model equation to qualitatively understand the formation of the solitary wave state.

Multiband Fourier Analysis and Interstellar Reddening of the Variable Stars in the Globular Cluster NGC 6402 (M14)

NASA Astrophysics Data System (ADS)

Weinschenk, Sedrick; Murphy, Brian; Villiger, Nathan J.

2018-01-01

We present a detailed study of the variable stars in the globular cluster NGC 6402 (M14). Approximately 1500 B and V band images were collected from July 2016 to August 2017 using the SARA Consortium Jacobus Kaptyen 1-meter telescope located in the Canary Islands. Using difference image analysis, we were able to identify 145 probable variable stars, confirming the 133 previously known variables and adding 12 new variables. The variables consisted of 117 RR Lyrae stars, 18 long period variables, 2 eclipsing variables, 6 Cepheid variables, and 2 SX Phoenix variables. Of the RR Lyrae variables 55 were of fundamental mode RR0 stars, of which 18 exhibited the Blazhko effect, 57 were of 1st overtone RR1, of which 7 appear to exhibit the Blazhko effect, 1 2nd overtone RR2, and 2 double mode variables. We found an average period of 0.59016 days for RR0 stars and 0.30294 days for RR1 stars. Using the multiband light curves of both the RR0 and RR1 variables we found an average E(B-V) of 0.604 with a scatter of 0.15 magnitudes. Using Fourier decomposition of the RR Lyrae light curves we also determined the metallicity and distance of the NGC 6402.

Kinematic analysis of jaw function in children following traumatic brain injury.

PubMed

Loh, E W L; Goozée, J V; Murdoch, B E

2005-07-01

To investigate jaw movements in children following traumatic brain injury (TBI) during speech using electromagnetic articulography (EMA). Jaw movements of two non-dysarthric children (aged 12.75 and 13.08 years) who had sustained a TBI were recorded using the AG-100 EMA system (Carstens Medizineletronik) during word-initial consonant productions. Mean quantitative kinematic parameters and coefficient of variation (variability) values were calculated and individually compared to the mean values obtained by a group of six control children (mean age 12.57 years, SD 1.52). The two children with TBI exhibited word-initial consonant jaw movement durations that were comparable to the control children, with sub-clinical reductions in speed being offset by reduced distances. Differences were observed between the two children in jaw kinematic variability, with one child exhibiting increased variability, while the other child demonstrated reduced or comparable variability compared to the control group. Possible sub-clinical impairments of jaw movement for speech were exhibited by two children who had sustained a TBI, providing insight into the consequences of TBI on speech motor control development.

The complexity of the HANG SENG Index and its constituencies during the 2007-2008 Great Recession

NASA Astrophysics Data System (ADS)

Argyroudis, G.; Siokis, F.

2018-04-01

We apply the multifractal detrended moving average (MF-DMA) procedure to the daily data from HANG SENG Index (HSI) and two sub-indices, the Properties Index which consists of 10 Real Estate Companies and the Finance Index with 12 companies respectively. Two major events are considered: the 2007 and the 1997 crises. Based on scaling exponents and the singularity spectrum analysis, we show that both events reveal multiscaling and the results are robust across different indices. Furthermore, by dividing the data into two equal sub-samples for prior and after the crisis periods, we reveal that for the 2007-2008 crisis, the complexity of the HSI and Properties index remain the same between periods, while for the Finance Index, the after crisis period exhibits richer multifractality and higher complexity. Especially for the Properties Index, the results indicate that the Real Estate sector was not affected as much, by the transitory shocks of the Great Recession. As for the 1997 event, the HS Index is impacted greatly in the after period crisis exhibiting higher degree of multifractality and heterogeneity.

PubMed Central

MAGGI, LORENZO; SALERNO, FRANCO; BRAGATO, CINZIA; SAREDI, SIMONA; BLASEVICH, FLAVIA; MACCAGNANO, ELIO; PASANISI, BARBARA; DANESINO, CESARE; MORA, MARINA; MORANDI, LUCIA

2013-01-01

The adult-onset form of Pompe disease had a wide clinical spectrum, ranging from asymptomatic patients with increased CK to muscle cramps and pain syndrome or rigid-spine syndrome. In addition clinical severity and disease progression are greatly variable. We report on a family with 3 siblings characterized by an unusual adult-onset Pompe disease including dysphagia and weakness of tongue, axial and limb-girdle muscles, in association with atypical globular inclusions in muscle fibres. Our study confirms the great clinical and histological variability of adult-onset Pompe disease and further supports the need of careful evaluation of bulbar function in patients affected by this pathology. PMID:24399864

What makes Great Basin sagebrush ecosystems invasible by Bromus tectorum?

Treesearch

Jeanne C. Chambers; Bruce A. Roundy; Robert R. Blank; Susan E. Meyer; A. Whittaker

2007-01-01

Ecosystem susceptibility to invasion by nonnative species is poorly understood, but evidence is increasing that spatial and temporal variability in resources has large-scale effects. We conducted a study in Artemisia tridentata ecosystems at two Great Basin locations examining differences in resource availability and invasibility of Bromus...

Soil modulates the effect of precipitation seasonality on bioenergy crop production

USDA-ARS?s Scientific Manuscript database

Background/Questions/Methods Future climate change scenarios remain uncertain with respect to precipitation amounts and variability. In the U.S. Great Plains, spring precipitation is expected to decrease in the lower Great Plains but increase 20%–40% in the upper Mississippi Valley, suggesting pot...

INVITED REVIEW: Getting more information from your grazing research beyond cattle performance 1,2

USDA-ARS?s Scientific Manuscript database

Research examining the nutrition of grazing ruminants can be a rewarding career; however, this type of science possesses great challenges. This type of research requires the scientist to make many assumptions, deal with great variability across a landscape, and requires careful planning to manage t...

Margins of stability in young adults with traumatic transtibial amputation walking in destabilizing environments✫

PubMed Central

Beltran, Eduardo J.; Dingwell, Jonathan B.; Wilken, Jason M.

2014-01-01

Understanding how lower-limb amputation affects walking stability, specifically in destabilizing environments, is essential for developing effective interventions to prevent falls. This study quantified mediolateral margins of stability (MOS) and MOS sub-components in young individuals with traumatic unilateral transtibial amputation (TTA) and young able-bodied individuals (AB). Thirteen AB and nine TTA completed five 3-minute walking trials in a Computer Assisted Rehabilitation ENvironment (CAREN) system under three each of three test conditions: no perturbations, pseudo-random mediolateral translations of the platform, and pseudo-random mediolateral translations of the visual field. Compared to the unperturbed trials, TTA exhibited increased mean MOS and MOS variability during platform and visual field perturbations (p < 0.010). Also, AB exhibited increased mean MOS during visual field perturbations and increased MOS variability during both platform and visual field perturbations (p < 0.050). During platform perturbations, TTA exhibited significantly greater values than AB for mean MOS (p < 0.050) and MOS variability (p < 0.050); variability of the lateral distance between the center of mass (COM) and base of support at initial contact (p < 0.005); mean and variability of the range of COM motion (p < 0.010); and variability of COM peak velocity (p < 0.050). As determined by mean MOS and MOS variability, young and otherwise healthy individuals with transtibial amputation achieved stability similar to that of their able-bodied counterparts during unperturbed and visually-perturbed walking. However, based on mean and variability of MOS, unilateral transtibial amputation was shown to have affected walking stability during platform perturbations. PMID:24444777

Inter-individual variability in the patterns of responses for electromyography and mechanomyography during cycle ergometry using an RPE-clamp model.

PubMed

Cochrane-Snyman, Kristen C; Housh, Terry J; Smith, Cory M; Hill, Ethan C; Jenkins, Nathaniel D M; Schmidt, Richard J; Johnson, Glen O

2016-09-01

To examine inter-individual variability versus composite models for the patterns of responses for electromyography (EMG) and mechanomyography (MMG) versus time relationships during moderate and heavy cycle ergometry using a rating of perceived exertion (RPE) clamp model. EMG amplitude (amplitude root-mean-square, RMS), EMG mean power frequency (MPF), MMG-RMS, and MMG-MPF were collected during two, 60-min rides at a moderate (RPE at the gas exchange threshold; RPEGET) and heavy (RPE at 15 % above the GET; RPEGET+15 %) intensity when RPE was held constant (clamped). Composite (mean) and individual responses for EMG and MMG parameters were compared during each 60-min ride. There was great inter-individual variability for each EMG and MMG parameters at RPEGET and RPEGET+15 %. Composite models showed decreases in EMG-RMS (r (2) = -0.92 and R (2) = 0.96), increases in EMG-MPF (R (2) = 0.90), increases in MMG-RMS (r (2) = 0.81 and 0.55), and either no change or a decrease (r (2) = 0.34) in MMG-MPF at RPEGET and RPEGET+15 %, respectively. The results of the present study indicated that there were differences between composite and individual patterns of responses for EMG and MMG parameters during moderate and heavy cycle ergometry at a constant RPE. Thus, composite models did not represent the unique muscle activation strategies exhibited by individual responses when cycling in the moderate and heavy intensity domains when using an RPE-clamp model.

Understanding the interdecadal variabilities of East Asian summer precipitation: from a perspective of joint influence of oceanic forcings

NASA Astrophysics Data System (ADS)

Zhang, Z.; Sun, X.; Yang, X. Q.

2017-12-01

East Asian summer precipitation (EASP) is highly complicated in both temporal and spatial variabilities at interdecadal time scales, with various time periods and anomalous spatial distribution patterns. The joint influences of three dominant interdecadal signals, i.e., Pacific Decadal Oscillation (PDO), Atlantic Multidecadal Oscillation (AMO) and Indian Ocean Basin Mode (IOBM), are revealed to be responsible for most of the interdecadal variabilities of EASP in this study, which, however, are not the simply linear combinations of their individual climate effects. Specifically, when PDO and AMO are in antiphase, SST anomalies of the same signs appear in both North Pacific and North Atlantic, the Asian westerly jet (AWJ) is accelerated and acts as a waveguide, favoring a zonally orientated Rossby wave train from North Atlantic to northern East Asia across the mid-high latitude Eurasia. Correspondingly, interdecadal precipitation anomalies exhibit a meridional tripole mode over East China. When PDO and AMO are in phase with oppositely signed SST anomalies in North Pacific and North Atlantic, the waveguide mechanism doesn't work since AWJ is significantly reduced, and the Rossby wave train from North Atlantic travels to South Asia along the great circle path, causing anomalous Indian summer monsoon precipitation (ISMP). In turn, by triggering another Rossby wave trains along both the mid-latitudes and coastal regions of East Asia, the ISMP anomalies induce a meridional dipole mode of interdecadal precipitation anomalies over East China. Through the ISMP and the same dynamical processes, IOBM is more important for the interdecadal precipitation anomalies over northern East Asia.

Variable-focus side-firing endoscopic device

NASA Astrophysics Data System (ADS)

Lemberg, Vladimir G.; Black, Michael

1996-05-01

Conventional side-firing fiber technology exhibits performance limitations and utilizes expensive single-use only devices which often require multiple fibers for laser prostatectomy. Another limitation of existing side-firing fiber technology is its inability to focus the beam to create incisions for urologic applications such as laser TURP (transurethral resectional prostatectomy), tumor necrosis, lithotripsy, genital warts, and photodynamic therapy. Newly introduced variable-focus side-firing endoscopic device utilizes either one or two lenses and a mirror, onto a single cylinder of molded glass. The laser beam exits the optical fiber, passes through the lens, strikes the cylindrical mirror, and traverses the cylindrical surface. Depending on the design, the laser beam is reflected at the angles ranging from 30 degrees to 120 degrees out of the cylindrical lens. A second lens can be formed onto the side of the cylindrical surface at the beam's exit point. Another advantage of the innovative side-firing device is its capability to provide versatile matching to multiple laser wavelengths from 360 nm to 2.5 microns, and achieve power densities great enough to perform vaporization, incision and coagulation of tissue. Precise focusing of the laser beam results in reduced tissue necrosis of surrounding the treatment area as well as in decreased laser radiation back-scattering. Surgeons can very the focus by adjusting the distance from the tip to the target area. The variable focus side-firing device provides a focused beam at the range of 1.0 to 1.5 mm, for incision. Outside this range, it produces a defocused beam for coagulation.

Morphological description of great cardiac vein in pigs compared to human hearts.

PubMed

Alejandro Gómez, Fabian; Ballesteros, Luis Ernesto; Stella Cortés, Luz

2015-01-01

In spite of its importance as an experimental model, the information on the great cardiac vein in pigs is sparse. To determine the morphologic characteristics of the great cardiac vein and its tributaries in pigs. 120 hearts extracted from pigs destined to the slaughterhouse with stunning method were studied. This descriptive cross-over study evaluated continuous variables with T test and discrete variables with Pearson χ square test. A level of significance P<0.05 was used. The great cardiac vein and its tributaries were perfused with polyester resin (85% Palatal and 15% Styrene) and then subjected to potassium hydroxide infusion to release the subepicardial fat. Calibers were measured, and trajectories and relations with adjacent arterial structures were evaluated. The origin of the great cardiac vein was observed at the heart apex in 91 (76%) hearts. The arterio-venous trigone was present in 117 (97.5%) specimens, corresponding to the open expression in its lower segment and to the closed expression in the upper segment in the majority of the cases (65%). The caliber of the great cardiac vein at the upper segment of the paraconal interventricular sulcus was 3.73±0.79 mm. An anastomosis between the great cardiac vein and the middle cardiac vein was found in 59 (49%) specimens. The morphological and biometric characteristics of the great cardiac vein and its tributaries had not been reported in prior studies, and due to their similitude with those of the human heart, allows us to propose the pig model for procedural and hemodynamic applications.

Using natural range of variation to set decision thresholds: a case study for great plains grasslands

USGS Publications Warehouse

Symstad, Amy J.; Jonas, Jayne L.; Edited by Guntenspergen, Glenn R.

2014-01-01

Natural range of variation (NRV) may be used to establish decision thresholds or action assessment points when ecological thresholds are either unknown or do not exist for attributes of interest in a managed ecosystem. The process for estimating NRV involves identifying spatial and temporal scales that adequately capture the heterogeneity of the ecosystem; compiling data for the attributes of interest via study of historic records, analysis and interpretation of proxy records, modeling, space-for-time substitutions, or analysis of long-term monitoring data; and quantifying the NRV from those data. At least 19 National Park Service (NPS) units in North America’s Great Plains are monitoring plant species richness and evenness as indicators of vegetation integrity in native grasslands, but little information on natural, temporal variability of these indicators is available. In this case study, we use six long-term vegetation monitoring datasets to quantify the temporal variability of these attributes in reference conditions for a variety of Great Plains grassland types, and then illustrate the implications of using different NRVs based on these quantities for setting management decision thresholds. Temporal variability of richness (as measured by the coefficient of variation, CV) is fairly consistent across the wide variety of conditions occurring in Colorado shortgrass prairie to Minnesota tallgrass sand savanna (CV 0.20–0.45) and generally less than that of production at the same sites. Temporal variability of evenness spans a greater range of CV than richness, and it is greater than that of production in some sites but less in other sites. This natural temporal variability may mask undesirable changes in Great Plains grasslands vegetation. Consequently, we suggest that managers consider using a relatively narrow NRV (interquartile range of all richness or evenness values observed in reference conditions) for designating a surveillance threshold, at which greater attention to the situation would be paid, and a broader NRV for designating management thresholds, at which action would be instigated.

Sex differences and plasticity in dehydration tolerance: insight from a tropical liverwort

PubMed Central

Marks, Rose A.; Burton, James F.; McLetchie, D. Nicholas

2016-01-01

Background and Aims Adaptations allowing plants to cope with drying are particularly relevant in the light of predicted climate change. Dehydration tolerance (DhT, also dehydration-tolerant) is one such adaptation enabling tissue to survive substantial drying. A great deal of work has been conducted on highly DhT species. However, bryophytes showing less intense and variable DhT are understudied, despite the potential for these species to provide an informative link between highly tolerant and sensitive species. In this study, we tested the degree to which DhT varies across populations and the sexes of a species expected to exhibit a moderate DhT phenotype. Methods To test predicted patterns of tolerance we assessed DhT in males and females of Marchantia inflexa from two distinct habitat types that differ in water availability. Both common garden and field-collected tissue was subjected to drying assays at multiple intensities and recovery was monitored by chlorophyll florescence. Verification studies were conducted to confirm the level of dehydration, the rate of drying and the associated changes in photosynthetic physiology. Key Results We confirmed our expectation that M. inflexa is able to tolerate moderate dehydration. We also found that females exhibited higher DhT than males, but populations did not differ in DhT when cultured in a common garden. However, field-collected samples exhibited differences in DhT corresponding to environmental dryness, suggesting plasticity in DhT. Conclusions By studying a less extreme DhT phenotype we gained insight into how more sensitive (yet still tolerant) organisms cope with dehydration. Additionally, the identified sex-specific variation in DhT may explain ecological patterns such as female-biased sex ratios. Furthermore, plasticity in DhT has the potential to inform management practices aimed at increasing tolerance to drought conditions. PMID:27325895

Evolutionary Determinants of Morphological Polymorphism in Colonial Animals.

PubMed

Simpson, Carl; Jackson, Jeremy B C; Herrera-Cubilla, Amalia

2017-07-01

Colonial animals commonly exhibit morphologically polymorphic modular units that are phenotypically distinct and specialize in specific functional tasks. But how and why these polymorphic modules have evolved is poorly understood. Across colonial invertebrates, there is wide variation in the degree of polymorphism, from none in colonial ascidians to extreme polymorphism in siphonophores, such as the Portuguese man-of-war. Bryozoa are a phylum of exclusively colonial invertebrates that uniquely exhibit almost the entire range of polymorphism, from monomorphic species to others that rival siphonophores in their polymorphic complexity. Previous approaches to understanding the evolution of polymorphism have been based on analyses of (1) the functional role of polymorphs or (2) presumed evolutionary costs and benefits based on evolutionary theory that postulates polymorphism should be evolutionarily sustainable only in more stable environments because polymorphism commonly leads to the loss of feeding and sexual competence. Here we use bryozoans from opposite shores of the Isthmus of Panama to revisit the environmental hypothesis by comparison of faunas from distinct oceanographic provinces that differ greatly in environmental variability, and we then examine the correlations between the extent of polymorphism in relation to patterns of ecological succession and variation in life histories. We find no support for the environmental hypothesis. Distributions of the incidence of polymorphism in the oceanographically unstable Eastern Pacific are indistinguishable from those in the more stable Caribbean. In contrast, the temporal position of species in a successional sequence is collinear with the degree of polymorphism because species with fewer types of polymorphs are competitively replaced by species with higher numbers of polymorphs on the same substrata. Competitively dominant species also exhibit patterns of growth that increase their competitive ability. The association between degrees of polymorphism and variations in life histories is fundamental to understanding of the macroevolution of polymorphism.

Functionally relevant climate variables for arid lands: Aclimatic water deficit approach for modelling desert shrub distributions

Treesearch

Thomas E. Dilts; Peter J. Weisberg; Camie M. Dencker; Jeanne C. Chambers

2015-01-01

We have three goals. (1) To develop a suite of functionally relevant climate variables for modelling vegetation distribution on arid and semi-arid landscapes of the Great Basin, USA. (2) To compare the predictive power of vegetation distribution models based on mechanistically proximate factors (water deficit variables) and factors that are more mechanistically removed...

Designing low-carbon power systems for Great Britain in 2050 that are robust to the spatiotemporal and inter-annual variability of weather

NASA Astrophysics Data System (ADS)

Zeyringer, Marianne; Price, James; Fais, Birgit; Li, Pei-Hao; Sharp, Ed

2018-05-01

The design of cost-effective power systems with high shares of variable renewable energy (VRE) technologies requires a modelling approach that simultaneously represents the whole energy system combined with the spatiotemporal and inter-annual variability of VRE. Here, we soft-link a long-term energy system model, which explores new energy system configurations from years to decades, with a high spatial and temporal resolution power system model that captures VRE variability from hours to years. Applying this methodology to Great Britain for 2050, we find that VRE-focused power system design is highly sensitive to the inter-annual variability of weather and that planning based on a single year can lead to operational inadequacy and failure to meet long-term decarbonization objectives. However, some insights do emerge that are relatively stable to weather-year. Reinforcement of the transmission system consistently leads to a decrease in system costs while electricity storage and flexible generation, needed to integrate VRE into the system, are generally deployed close to demand centres.

A Comparative Assessment of the Influences of Human Impacts on Soil Cd Concentrations Based on Stepwise Linear Regression, Classification and Regression Tree, and Random Forest Models

PubMed Central

Qiu, Lefeng; Wang, Kai; Long, Wenli; Wang, Ke; Hu, Wei; Amable, Gabriel S.

2016-01-01

Soil cadmium (Cd) contamination has attracted a great deal of attention because of its detrimental effects on animals and humans. This study aimed to develop and compare the performances of stepwise linear regression (SLR), classification and regression tree (CART) and random forest (RF) models in the prediction and mapping of the spatial distribution of soil Cd and to identify likely sources of Cd accumulation in Fuyang County, eastern China. Soil Cd data from 276 topsoil (0–20 cm) samples were collected and randomly divided into calibration (222 samples) and validation datasets (54 samples). Auxiliary data, including detailed land use information, soil organic matter, soil pH, and topographic data, were incorporated into the models to simulate the soil Cd concentrations and further identify the main factors influencing soil Cd variation. The predictive models for soil Cd concentration exhibited acceptable overall accuracies (72.22% for SLR, 70.37% for CART, and 75.93% for RF). The SLR model exhibited the largest predicted deviation, with a mean error (ME) of 0.074 mg/kg, a mean absolute error (MAE) of 0.160 mg/kg, and a root mean squared error (RMSE) of 0.274 mg/kg, and the RF model produced the results closest to the observed values, with an ME of 0.002 mg/kg, an MAE of 0.132 mg/kg, and an RMSE of 0.198 mg/kg. The RF model also exhibited the greatest R2 value (0.772). The CART model predictions closely followed, with ME, MAE, RMSE, and R2 values of 0.013 mg/kg, 0.154 mg/kg, 0.230 mg/kg and 0.644, respectively. The three prediction maps generally exhibited similar and realistic spatial patterns of soil Cd contamination. The heavily Cd-affected areas were primarily located in the alluvial valley plain of the Fuchun River and its tributaries because of the dramatic industrialization and urbanization processes that have occurred there. The most important variable for explaining high levels of soil Cd accumulation was the presence of metal smelting industries. The good performance of the RF model was attributable to its ability to handle the non-linear and hierarchical relationships between soil Cd and environmental variables. These results confirm that the RF approach is promising for the prediction and spatial distribution mapping of soil Cd at the regional scale. PMID:26964095

A Comparative Assessment of the Influences of Human Impacts on Soil Cd Concentrations Based on Stepwise Linear Regression, Classification and Regression Tree, and Random Forest Models.

PubMed

Qiu, Lefeng; Wang, Kai; Long, Wenli; Wang, Ke; Hu, Wei; Amable, Gabriel S

2016-01-01

Soil cadmium (Cd) contamination has attracted a great deal of attention because of its detrimental effects on animals and humans. This study aimed to develop and compare the performances of stepwise linear regression (SLR), classification and regression tree (CART) and random forest (RF) models in the prediction and mapping of the spatial distribution of soil Cd and to identify likely sources of Cd accumulation in Fuyang County, eastern China. Soil Cd data from 276 topsoil (0-20 cm) samples were collected and randomly divided into calibration (222 samples) and validation datasets (54 samples). Auxiliary data, including detailed land use information, soil organic matter, soil pH, and topographic data, were incorporated into the models to simulate the soil Cd concentrations and further identify the main factors influencing soil Cd variation. The predictive models for soil Cd concentration exhibited acceptable overall accuracies (72.22% for SLR, 70.37% for CART, and 75.93% for RF). The SLR model exhibited the largest predicted deviation, with a mean error (ME) of 0.074 mg/kg, a mean absolute error (MAE) of 0.160 mg/kg, and a root mean squared error (RMSE) of 0.274 mg/kg, and the RF model produced the results closest to the observed values, with an ME of 0.002 mg/kg, an MAE of 0.132 mg/kg, and an RMSE of 0.198 mg/kg. The RF model also exhibited the greatest R2 value (0.772). The CART model predictions closely followed, with ME, MAE, RMSE, and R2 values of 0.013 mg/kg, 0.154 mg/kg, 0.230 mg/kg and 0.644, respectively. The three prediction maps generally exhibited similar and realistic spatial patterns of soil Cd contamination. The heavily Cd-affected areas were primarily located in the alluvial valley plain of the Fuchun River and its tributaries because of the dramatic industrialization and urbanization processes that have occurred there. The most important variable for explaining high levels of soil Cd accumulation was the presence of metal smelting industries. The good performance of the RF model was attributable to its ability to handle the non-linear and hierarchical relationships between soil Cd and environmental variables. These results confirm that the RF approach is promising for the prediction and spatial distribution mapping of soil Cd at the regional scale.

Water-vapour variability within a convective boundary-layer assessed by large-eddy simulations and IHOP_2002 observations

NASA Astrophysics Data System (ADS)

Couvreux, F.; Guichard, F.; Redelsperger, J. L.; Kiemle, C.; Masson, V.; Lafore, J. P.; Flamant, C.

2005-10-01

This study presents a comprehensive analysis of the variability of water vapour in a growing convective boundary-layer (CBL) over land, highlighting the complex links between advection, convective activity and moisture heterogeneity in the boundary layer. A Large-eddy Simulation (LES) is designed, based on observations, and validated, using an independent data-set collected during the International H2O Project (IHOP 2002) fieldexperiment. Ample information about the moisture distribution in space and time, as well as other important CBL parameters are acquired by mesonet stations, balloon soundings, instruments on-board two aircraft and the DLR airborne water-vapour differential-absorption lidar. Because it can deliver two-dimensional cross-sections at high spatial resolution (140 m horizontal, 200 m vertical), the airborne lidar offers valuable insights of small-scale moisture-variability throughout the CBL. The LES is able to reproduce the development of the CBL in the morning and early afternoon, as assessed by comparisons of simulated mean profiles of key meteorological variables with sounding data. Simulated profiles of the variance of water-vapour mixing-ratio were found to be in good agreement with the lidar-derived counterparts. Finally, probability-density functions of potential temperature, vertical velocity and water-vapour mixing-ratio calculated from the LES show great consistency with those derived from aircraft in situ measurements in the middle of the CBL. Downdraughts entrained from above the CBL are governing the scale of moisture variability. Characteristic length-scales are found to be larger for water-vapour mixing-ratio than for temperature.The observed water-vapour variability exhibits contributions from different scales. The influence of the mesoscale (larger than LES domain size, i.e. 10 km) on the smaller-scale variability is assessed using LES and observations. The small-scale variability of water vapour is found to be important and to be driven by the dynamics of the CBL. Both lidar observations and LES evidence that dry downdraughts entrained from above the CBL are governing the scale of moisture variability. Characteristic length-scales are found to be larger for water-vapour mixing-ratio than for temperature and vertical velocity. In particular, intrusions of drier free-troposphere air from above the growing CBL impose a marked negative skewness on the water-vapour distribution within it, both as observed and in the simulation.

KSC-04PD-2203

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Inside a tent, employees look over an exhibit of work shoes. The exhibits were part of Spaceport Super Safety and Health Day, which also featured presentations by guest speakers Dr. Pamela Peeke, Navy Com. Stephen E. Iwanowicz, NASAs Dr. Kristine Calderon and Olympic-great Bruce Jenner. Vendors exhibits were set up in the parking areas outside the Vehicle Assembly Building and the O&C Building. The annual event was initiated at KSC in 1998 to increase awareness of the importance of safety and health among the government and contractor workforce. The theme for this years event was Safety and Health: A Winning Combination.

KSC-04PD-2204

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Inside a tent, employees look over an exhibit of safety equipment. The exhibits were part of Spaceport Super Safety and Health Day, which also featured presentations by guest speakers Dr. Pamela Peeke, Navy Com. Stephen E. Iwanowicz, NASAs Dr. Kristine Calderon and Olympic-great Bruce Jenner. Vendors exhibits were set up in the parking areas outside the Vehicle Assembly Building and the O&C Building. The annual event was initiated at KSC in 1998 to increase awareness of the importance of safety and health among the government and contractor workforce. The theme for this years event was Safety and Health: A Winning Combination.

Evapotranspiration in winter wheat under different grazing and tillage practices in the southern Great Plains

USDA-ARS?s Scientific Manuscript database

Precipitation in the Southern Great Plains (SGP) is highly variable both spatially and temporally with recurring periods of severe drought. Winter wheat (Triticum aestivum L.) – summer fallow system with conventional tillage is the principal dryland cropping system in this region for both grazing an...

Configuration and Intraseasonal Duration of Interannual Anomalies of the Great Plains Low-Level Jet

NASA Technical Reports Server (NTRS)

Helfand, H. M.

2002-01-01

Despite the fact that the low-level jet of the southern Great Plains (the GPLLJ) of the U.S. is primarily a nocturnal phenomenon that virtually vanishes during the daylight hours, it is one of the most persistent and stable climatological features of the low-level continental flow during the warm-season months, May through August. We have used significant-level data to validate the skill of the GEOS-1 Data Assimilation System (DAS) in realistically detecting this jet and inferring its structure and evolution. We have then carried out a 15-year reanalysis with the GEOS-1 DAS to determine its climatology and mean diurnal cycle and to study its interannual variability. Interannual anomalies of the meridional flow associated with the GPLLJ are much smaller than the mean diurnal fluctuations, than random intraseasonal anomalies, and than the mean wind itself. There are three maxima of low-level meridional flow variance over the Great Plains and the Gulf of Mexico: a 1.2 m2 s-2 peak over the southeast Texas, to the east and south of the mean velocity peak, a 1.0 m2 s-2 peak over the western Gulf of Mexico, and a .8 m2 s-2 peak over the upper Great Plains (UGP), near the Nebraska/South Dakota border. Each of the three variance maxima corresponds to a spatially coherent, jet-like pattern of low-level flow interannual variability. There are also three dominant modes of interannual variability corresponding to the three variance maxima, but not in a simple one-to-one relationship. Cross-sectional profiles of mean southerly wind over Texas remain relatively stable and recognizable from year to year with only its eastward flank showing significant variability. This variability, however, exhibits a distinct, biennial oscillation during the first six to seven years of the reanalysis period and only then. This intermittent biennial oscillation (IBO, one of the three modes discussed in the previous paragraph) in the lowlevel flow is restricted to the region surrounding eastern Texas and is also evident in the NCEP/NCAR reanalysis data set from about 1978 to 1985 or 1986 and again from 1995 to 2000. It is evident as well in surface pressure in both the GEOS-1 and NCEP/NCAR sets. The interannual anomalies do not necessarily persist uniformly throughout an entire season, but can fluctuate from one part of the season to the next. To estimate the characteristic sub-seasonal time scales for coherence of these fluctuations, we have taken the weekly anomaly of low-level wind at each point of the domain from the climatological average for that given point and that given week of the season and computed the covariance of its fluctuations over all weeks and over all years with the weekly climatological anomaly of the meridional wind at each of the three reference points discussed above. The typical duration of a coherent interannual anomaly within a given warm season increases with decreasing latitude from 2 to 3 weeks over the UGP, to 6 to 7 weeks over eastern Texas. Coherence over the western Gulf of Mexico is intermediate between the two with a typical duration of 4 to 5 weeks. There appears to be evidence that the interannual anomalies over Texas the Gulf propagate to the UGP after a week and those over the Gulf propagate there after 2 to 3 weeks. There also appears to be some reverse propagation of interannual anomalies over the UGP to Texas and to the Gulf after a period of about one week. The interannual anomalies in southerly flow over eastern Texas seem to correlate well with interannual anomalies of surface temperature and (negative) ground wetness and over western Texas.

Assimilating a decade of hydrometeorological ship measurements across the North American Great Lakes

NASA Astrophysics Data System (ADS)

Fries, K. J.; Kerkez, B.

2015-12-01

We use a decade of measurements made by the Volunteer Observing Ships (VOS) program on the North American Great Lakes to derive spatial estimates of over-lake air temperature, sea surface temperature, dewpoint, and wind speed. This Lagrangian data set, which annually comprises over 200,000 point observations from over 80,000 ship reports across a 244,000 square kilometer study area, is assimilated using a Gaussian Process machine learning algorithm. This algorithm classifies a model for each hydrometeorological variable using a combination of latitudes, longitudes, seasons of the year, as well as predictions made by the National Digital Forecast Database (NDFD) and Great Lakes Coastal Forecasting System (GLCFS) operational models. We show that our data-driven method significantly improves the spatial and temporal estimation of overlake hydrometeorological variables, while simultaneously providing uncertainty estimates that can be used to improve historical and future predictions on dense spatial and temporal scales. This method stands to improve the prediction of water levels on the Great Lakes, which comprise over 90% of America's surface fresh water, and impact the lives of millions of people living in the basin.

Novel Modeling Tools for Propagating Climate Change Variability and Uncertainty into Hydrodynamic Forecasts

EPA Science Inventory

Understanding impacts of climate change on hydrodynamic processes and ecosystem response within the Great Lakes is an important and challenging task. Variability in future climate conditions, uncertainty in rainfall-runoff model forecasts, the potential for land use change, and t...

Ranch profitability given increased precipitation variability and flexible stocking

USDA-ARS?s Scientific Manuscript database

Forage and cattle performance relationships with spring precipitation, combined with cattle market price variability, were incorporated into a ranch level model to determine if addition of a yearling enterprise to the base cow-calf herd would improve profitability with increasing (25% and 50% greate...

Quantifying spatial and temporal variabilities of microwave brightness temperature over the U.S. Southern Great Plains

NASA Technical Reports Server (NTRS)

Choudhury, B. J.; Owe, M.; Ormsby, J. P.; Chang, A. T. C.; Wang, J. R.; Goward, S. N.; Golus, R. E.

1987-01-01

Spatial and temporal variabilities of microwave brightness temperature over the U.S. Southern Great Plains are quantified in terms of vegetation and soil wetness. The brightness temperatures (TB) are the daytime observations from April to October for five years (1979 to 1983) obtained by the Nimbus-7 Scanning Multichannel Microwave Radiometer at 6.6 GHz frequency, horizontal polarization. The spatial and temporal variabilities of vegetation are assessed using visible and near-infrared observations by the NOAA-7 Advanced Very High Resolution Radiometer (AVHRR), while an Antecedent Precipitation Index (API) model is used for soil wetness. The API model was able to account for more than 50 percent of the observed variability in TB, although linear correlations between TB and API were generally significant at the 1 percent level. The slope of the linear regression between TB and API is found to correlate linearly with an index for vegetation density derived from AVHRR data.

Sexual dimorphic features within extant great ape faciodental skeletal anatomy and testing the single species hypothesis.

PubMed

Cameron, D W

1997-01-01

This paper examines sexually dimorphic skeletal characters within the face and upper dentition of extant hominids (great ape), not including members of the Hominini. Specimens of Pan paniscus, Pan troglodytes, Gorilla gorilla, and Pongo pygmaeus are used to help identify likely sex specific characters for the Hominidae. The aim of this paper is to identify extant hominid faciodental sexual features which can be used to help sex fossil specimens. A morphometric and skeletal study of sexual variability demonstrates relatively diverse patterns of sexual variability within the extant hominids. In terms of morphometrics, P. paniscus is relatively non-dimorphic, while P. troglodytes, Gorilla and Pongo display a large degree of sexual dimorphism. In their respective skeletal anatomies, however, each has specific characters which tend to differentiate between the sexes. Some faciodental sex features are shown to be common amongst all four taxa and as such are likely to be important criteria for determining the sex of Miocene and Plio-Pleistocene fossil hominid specimens. The construction of extant great ape sexual ranges of variability are also important in helping to test the fossil ape single species hypotheses. The testing of sex and species ranges of variability should employ range based statistics not only because they are sample size independent, (relative to C.V.) but also because they are of low power.

Statistical characteristics of cloud variability. Part 1: Retrieved cloud liquid water path at three ARM sites

NASA Astrophysics Data System (ADS)

Huang, Dong; Campos, Edwin; Liu, Yangang

2014-09-01

Statistical characteristics of cloud variability are examined for their dependence on averaging scales and best representation of probability density function with the decade-long retrieval products of cloud liquid water path (LWP) from the tropical western Pacific (TWP), Southern Great Plains (SGP), and North Slope of Alaska (NSA) sites of the Department of Energy's Atmospheric Radiation Measurement Program. The statistical moments of LWP show some seasonal variation at the SGP and NSA sites but not much at the TWP site. It is found that the standard deviation, relative dispersion (the ratio of the standard deviation to the mean), and skewness all quickly increase with the averaging window size when the window size is small and become more or less flat when the window size exceeds 12 h. On average, the cloud LWP at the TWP site has the largest values of standard deviation, relative dispersion, and skewness, whereas the NSA site exhibits the least. Correlation analysis shows that there is a positive correlation between the mean LWP and the standard deviation. The skewness is found to be closely related to the relative dispersion with a correlation coefficient of 0.6. The comparison further shows that the lognormal, Weibull, and gamma distributions reasonably explain the observed relationship between skewness and relative dispersion over a wide range of scales.

Extracellular cholesterol oxidase production by Streptomyces aegyptia, in vitro anticancer activities against rhabdomyosarcoma, breast cancer cell-lines and in vivo apoptosis.

PubMed

El-Naggar, Noura El-Ahmady; Soliman, Hoda M; El-Shweihy, Nancy M

2018-02-09

In recent years, microbial cholesterol oxidases have gained great attention due to its widespread use in medical applications for serum cholesterol determination. Streptomyces aegyptia strain NEAE-102 exhibited high level of extracellular cholesterol oxidase production using a minimum medium containing cholesterol as the sole source of carbon. Fifteen variables were screened using Plackett-Burman design for the enhanced cholesterol oxidase production. The most significant variables affecting enzyme production were further optimized by using the face-centered central composite design. The statistical optimization resulted in an overall 4.97-fold increase (15.631 UmL -1 ) in cholesterol oxidase production in the optimized medium as compared with the unoptimized medium before applying Plackett Burman design (3.1 UmL -1 ). The purified cholesterol oxidase was evaluated for its in vitro anticancer activities against five human cancer cell lines. The selectivity index values on rhabdomyosarcoma and breast cancer cell lines were 3.26 and 2.56; respectively. The in vivo anticancer activity of cholesterol oxidase was evaluated against Ehrlich solid tumor model. Compared with control mice, tumors growth was significantly inhibited in the mice injected with cholesterol oxidase alone, doxorubicin alone and cholesterol oxidase/doxorubicin combination by 60.97%, 72.99% and 97.04%; respectively. These results demonstrated that cholesterol oxidase can be used as a promising natural anticancer drug.

Why do electricity policy and competitive markets fail to use advanced PV systems to improve distribution power quality?

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

McHenry, Mark P.; Johnson, Jay; Hightower, Mike

The increasing pressure for network operators to meet distribution network power quality standards with increasing peak loads, renewable energy targets, and advances in automated distributed power electronics and communications is forcing policy-makers to understand new means to distribute costs and benefits within electricity markets. Discussions surrounding how distributed generation (DG) exhibits active voltage regulation and power factor/reactive power control and other power quality capabilities are complicated by uncertainties of baseline local distribution network power quality and to whom and how costs and benefits of improved electricity infrastructure will be allocated. DG providing ancillary services that dynamically respond to the networkmore » characteristics could lead to major network improvements. With proper market structures renewable energy systems could greatly improve power quality on distribution systems with nearly no additional cost to the grid operators. Renewable DG does have variability challenges, though this issue can be overcome with energy storage, forecasting, and advanced inverter functionality. This paper presents real data from a large-scale grid-connected PV array with large-scale storage and explores effective mitigation measures for PV system variability. As a result, we discuss useful inverter technical knowledge for policy-makers to mitigate ongoing inflation of electricity network tariff components by new DG interconnection requirements or electricity markets which value power quality and control.« less

Why do electricity policy and competitive markets fail to use advanced PV systems to improve distribution power quality?

DOE PAGES

McHenry, Mark P.; Johnson, Jay; Hightower, Mike

2016-01-01

The increasing pressure for network operators to meet distribution network power quality standards with increasing peak loads, renewable energy targets, and advances in automated distributed power electronics and communications is forcing policy-makers to understand new means to distribute costs and benefits within electricity markets. Discussions surrounding how distributed generation (DG) exhibits active voltage regulation and power factor/reactive power control and other power quality capabilities are complicated by uncertainties of baseline local distribution network power quality and to whom and how costs and benefits of improved electricity infrastructure will be allocated. DG providing ancillary services that dynamically respond to the networkmore » characteristics could lead to major network improvements. With proper market structures renewable energy systems could greatly improve power quality on distribution systems with nearly no additional cost to the grid operators. Renewable DG does have variability challenges, though this issue can be overcome with energy storage, forecasting, and advanced inverter functionality. This paper presents real data from a large-scale grid-connected PV array with large-scale storage and explores effective mitigation measures for PV system variability. As a result, we discuss useful inverter technical knowledge for policy-makers to mitigate ongoing inflation of electricity network tariff components by new DG interconnection requirements or electricity markets which value power quality and control.« less

Population bottleneck triggering millennial-scale morphospace shifts in endemic thermal-spring melanopsids.

PubMed

Neubauer, Thomas A; Harzhauser, Mathias; Georgopoulou, Elisavet; Wrozyna, Claudia

2014-11-15

For more than hundred years the thermal spring-fed Lake Pețea near Oradea, Romania, was studied for its highly endemic subfossil and recent fauna and flora. One point of focus was the species lineage of the melanopsid gastropod Microcolpia parreyssii , which exhibited a tremendous diversity of shapes during the earlier Holocene. As a consequence many new species, subspecies, and variety-names have been introduced over time, trying to categorize this overwhelming variability. In contrast to the varied subfossil assemblage, only a single phenotype is present today. We critically review the apparent "speciation event" implied by the taxonomy, based on the presently available information and new data from morphometric analyses of shell outlines and oxygen and carbon isotope data. This synthesis shows that one turning point in morphological evolution coincides with high accumulation of peaty deposits during a short time interval of maximally a few thousand years. The formation of a small, highly eutrophic swamp with increased input of organic matter marginalized the melanopsids and reduced population size. The presented data make natural selection as the dominating force unlikely but rather indicates genetic drift following a bottleneck effect induced by the environmental changes. This claim contrasts the "obvious trend" and shows that great morphological variability has to be carefully and objectively evaluated in order to allow sound interpretations of the underlying mechanisms.

The size effect in corrosion greatly influences the predicted life span of concrete infrastructures.

PubMed

Angst, Ueli M; Elsener, Bernhard

2017-08-01

Forecasting the life of concrete infrastructures in corrosive environments presents a long-standing and socially relevant challenge in science and engineering. Chloride-induced corrosion of reinforcing steel in concrete is the main cause for premature degradation of concrete infrastructures worldwide. Since the middle of the past century, this challenge has been tackled by using a conceptual approach relying on a threshold chloride concentration for corrosion initiation ( C crit ). All state-of-the-art models for forecasting chloride-induced steel corrosion in concrete are based on this concept. We present an experiment that shows that C crit depends strongly on the exposed steel surface area. The smaller the tested specimen is, the higher and the more variable C crit becomes. This size effect in the ability of reinforced concrete to withstand corrosion can be explained by the local conditions at the steel-concrete interface, which exhibit pronounced spatial variability. The size effect has major implications for the future use of the common concept of C crit . It questions the applicability of laboratory results to engineering structures and the reproducibility of typically small-scale laboratory testing. Finally, we show that the weakest link theory is suitable to transform C crit from small to large dimensions, which lays the basis for taking the size effect into account in the science and engineering of forecasting the durability of infrastructures.

Photoproduction of hydrated electrons from natural organic solutes in aquatic environments

USGS Publications Warehouse

Zepp, R.G.; Braun, A.M.; Hoigne, J.; Leenheer, J.A.

1987-01-01

Laser flash photolysis was used to investigate the transients formed on absorption of 355-nm light by dissolved organic matter (DOM) from natural water bodies and from soil. Absorption spectra and quenching studies of the transients provided confirming evidence that hydrated electrons were formed by all of the DOM that were studied. The DOM from the Suwannee River in Georgia and from the Greifensee, a Swiss lake, exhibited great variability in light-absorbing properties. Despite this high variability in absorption coefficients, the primary quantum yields for electron ejection from the Greifensee and Suwannee DOM fell in a narrow range (0.005-0.008). Steady-state irradiations (355 nm) of the DOM with 2-chloroethanol (0.02 M) present as an electron scavenger produced chloride ions with quantum yields that were about 2 orders of magnitude lower than the primary quantum yields. This result indicates that most of the photoejected electrons recombine with cations before escaping into bulk solution. Irradiations of DOM solutions under sunlight (April, latitude 34?? N) photoproduced electrons at rates falling in the range of 0.2-0.4 ??mol/[(mg of DOC) h]. These results indicate that hydrated electrons can play a significant role in the environmental photoreduction of persistent, electronegative pollutants but may be relatively unimportant in the environmental production of hydrogen peroxide. ?? 1987 American Chemical Society.

The size effect in corrosion greatly influences the predicted life span of concrete infrastructures

PubMed Central

Angst, Ueli M.; Elsener, Bernhard

2017-01-01

Forecasting the life of concrete infrastructures in corrosive environments presents a long-standing and socially relevant challenge in science and engineering. Chloride-induced corrosion of reinforcing steel in concrete is the main cause for premature degradation of concrete infrastructures worldwide. Since the middle of the past century, this challenge has been tackled by using a conceptual approach relying on a threshold chloride concentration for corrosion initiation (Ccrit). All state-of-the-art models for forecasting chloride-induced steel corrosion in concrete are based on this concept. We present an experiment that shows that Ccrit depends strongly on the exposed steel surface area. The smaller the tested specimen is, the higher and the more variable Ccrit becomes. This size effect in the ability of reinforced concrete to withstand corrosion can be explained by the local conditions at the steel-concrete interface, which exhibit pronounced spatial variability. The size effect has major implications for the future use of the common concept of Ccrit. It questions the applicability of laboratory results to engineering structures and the reproducibility of typically small-scale laboratory testing. Finally, we show that the weakest link theory is suitable to transform Ccrit from small to large dimensions, which lays the basis for taking the size effect into account in the science and engineering of forecasting the durability of infrastructures. PMID:28782038

Ultraviolet and visible variability of the coma of Comet Levy (1990c)

NASA Technical Reports Server (NTRS)

Feldman, P. D.; Budzien, S. A.; Festou, M. C.; A'Hearn, M. F.; Tozzi, G. P.

1992-01-01

A visible lightcurve of Comet Levy obtained with the IUE Fine Error Sensor has revealed short-term coma variability. A production-rate source function is derivable from these data which implies a nucleus exhibiting hemispherically asymmetric activity. The ratio of gas-to-dust-production rates is also noted to exhibit asymmetry. The low dust-outflow velocity derived from observations, at about 200 m/sec, indicates a distribution that is rich in large, 3-10 micron particles.

A 3D quantitative comparison of trapezium and trapezoid relative articular and nonarticular surface areas in modern humans and great apes.

PubMed

Tocheri, M W; Razdan, A; Williams, R C; Marzke, M W

2005-11-01

The structure and functions of the modern human hand are critical components of what distinguishes Homo sapiens from the great apes (Gorilla, Pan, and Pongo). In this study, attention is focused on the trapezium and trapezoid, the two most lateral bones of the distal carpal row, in the four extant hominid genera, representing the first time they have been quantified and analyzed together as a morphological-functional complex. Our objective is to quantify the relative articular and nonarticular surface areas of these two bones and to test whether modern humans exhibit significant shape differences from the great apes, as predicted by previous qualitative analyses and the functional demands of differing manipulative and locomotor strategies. Modern humans were predicted to show larger relative first metacarpal and scaphoid surfaces on the trapezium because of the regular recruitment of the thumb during manipulative behaviors; alternatively, great apes were predicted to show larger relative second metacarpal and scaphoid surfaces on the trapezoid because of the functional demands on the hands during locomotor behaviors. Modern humans were also expected to exhibit larger relative mutual joint surfaces between the trapezoid and adjacent carpals than do the great apes because of assumed transverse loads generated by the functional demands of the modern human power grip. Using 3D bone models acquired through laser digitizing, the relative articular and nonarticular areas on each bone are quantified and compared. Multivariate analyses of these data clearly distinguish modern humans from the great apes. In total, the observed differences between modern humans and the great apes support morphological predictions based on the fact that this region of the human wrist is no longer involved in weight-bearing during locomotor behavior and is instead recruited solely for manipulative behaviors. The results provide the beginnings of a 3D comparative standard against which further extant and fossil primate wrist bones can be compared within the contexts of manipulative and locomotor behaviors.

Implications of hydrologic variability on the succession of plants in Great Lakes wetlands

USGS Publications Warehouse

Wilcox, Douglas A.

2004-01-01

Primary succession of plant communities directed toward a climax is not a typical occurrence in wetlands because these ecological systems are inherently dependent on hydrology, and temporal hydrologic variability often causes reversals or setbacks in succession. Wetlands of the Great Lakes provide good examples for demonstrating the implications of hydrology in driving successional processes and for illustrating potential misinterpretations of apparent successional sequences. Most Great Lakes coastal wetlands follow cyclic patterns in which emergent communities are reduced in area or eliminated by high lake levels and then regenerated from the seed bank during low lake levels. Thus, succession never proceeds for long. Wetlands also develop in ridge and swale terrains in many large embayments of the Great Lakes. These formations contain sequences of wetlands of similar origin but different age that can be several thousand years old, with older wetlands always further from the lake. Analyses of plant communities across a sequence of wetlands at the south end of Lake Michigan showed an apparent successional pattern from submersed to floating to emergent plants as water depth decreased with wetland age. However, paleoecological analyses showed that the observed vegetation changes were driven largely by disturbances associated with increased human settlement in the area. Climate-induced hydrologic changes were also shown to have greater effects on plant-community change than autogenic processes. Other terms, such as zonation, maturation, fluctuations, continuum concept, functional guilds, centrifugal organization, pulse stability, and hump-back models provide additional means of describing organization and changes in vegetation; some of them overlap with succession in describing vegetation processes in Great Lakes wetlands, but each must be used in the proper context with regard to short- and long-term hydrologic variability.

Potential distribution of the viral haemorrhagic septicaemia virus in the Great Lakes region

USGS Publications Warehouse

Escobar, Luis E.; Kurath, Gael; Escobar-Dodero, Joaquim; Craft, Meggan E.; Phelps, Nicholas B.D.

2017-01-01

Viral haemorrhagic septicaemia virus (VHSV) genotype IVb has been responsible for large-scale fish mortality events in the Great Lakes of North America. Anticipating the areas of potential VHSV occurrence is key to designing epidemiological surveillance and disease prevention strategies in the Great Lakes basin. We explored the environmental features that could shape the distribution of VHSV, based on remote sensing and climate data via ecological niche modelling. Variables included temperature measured during the day and night, precipitation, vegetation, bathymetry, solar radiation and topographic wetness. VHSV occurrences were obtained from available reports of virus confirmation in laboratory facilities. We fit a Maxent model using VHSV-IVb reports and environmental variables under different parameterizations to identify the best model to determine potential VHSV occurrence based on environmental suitability. VHSV reports were generated from both passive and active surveillance. VHSV occurrences were most abundant near shore sites. We were, however, able to capture the environmental signature of VHSV based on the environmental variables employed in our model, allowing us to identify patterns of VHSV potential occurrence. Our findings suggest that VHSV is not at an ecological equilibrium and more areas could be affected, including areas not in close geographic proximity to past VHSV reports.

Sex and family history of cardiovascular disease influence heart rate variability during stress among healthy adults.

PubMed

Emery, Charles F; Stoney, Catherine M; Thayer, Julian F; Williams, DeWayne; Bodine, Andrew

2018-07-01

Studies of sex differences in heart rate variability (HRV) typically have not accounted for the influence of family history (FH) of cardiovascular disease (CVD). This study evaluated sex differences in HRV response to speech stress among men and women (age range 30-49 years) with and without a documented FH of CVD. Participants were 77 adults (mean age = 39.8 ± 6.2 years; range: 30-49 years; 52% female) with positive FH (FH+, n = 32) and negative FH (FH-, n = 45) of CVD, verified with relatives of participants. Cardiac activity for all participants was recorded via electrocardiogram during a standardized speech stress task with three phases: 5-minute rest, 5-minute speech, and 5-minute recovery. Outcomes included time domain and frequency domain indicators of HRV and heart rate (HR) at rest and during stress. Data were analyzed with repeated measures analysis of variance, with sex and FH as between subject variables and time/phase as a within subject variable. Women exhibited higher HR than did men and greater HR reactivity in response to the speech stress. However, women also exhibited greater HRV in both the time and frequency domains. FH+ women generally exhibited elevated HRV, despite the elevated risk of CVD associated with FH+. Although women participants exhibited higher HR at rest and during stress, women (both FH+ and FH-) also exhibited elevated HRV reactivity, reflecting greater autonomic control. Thus, enhanced autonomic function observed in prior studies of HRV among women is also evident among FH+ women during a standardized stress task. Copyright © 2018 Elsevier Inc. All rights reserved.

The Vikings Are Coming!

ERIC Educational Resources Information Center

Zeller, Terry

1981-01-01

The author describes how advance planning of tours, inservice, and teaching materials by school and museum educators ensured that Minneapolis teachers and students learned a great deal when the traveling museum exhibit "The Vikings" came to their city. (SJL)

The Dynamics of Laurentian Great Lakes Surface Energy Budgets

NASA Astrophysics Data System (ADS)

Spence, C.; Blanken, P.; Lenters, J. D.; Gronewold, A.; Kerkez, B.; Xue, P.; Froelich, N.

2015-12-01

The Laurentian Great Lakes constitute the largest freshwater surface in the world and are a valuable North American natural and socio-economic resource. In response to calls for improved monitoring and research on the energy and water budgets of the lakes, there has been a growing ensemble of in situ measurements - including offshore eddy flux towers, buoy-based sensors, and vessel-based platforms -deployed through an ongoing, bi-national collaboration known as the Great Lakes Evaporation Network (GLEN). The objective of GLEN is to reduce uncertainty in Great Lakes seasonal and 6-month water level forecasts, as well as climate change projections of the surface energy balance and water level fluctuations. Although It remains challenging to quantify and scale energy budgets and fluxes over such large water bodies, this presentation will report on recent successes in three areas: First, in estimating evaporation rates over each of the Great Lakes; Second, defining evaporation variability among the lakes, especially in winter and; Third, explaining the interaction between ice cover, water temperature, and evaporation across a variety of temporal and spatial scales. Research gaps remain, particularly those related to spatial variability and scaling of turbulent fluxes, so the presentation will also describe how this will be addressed with enhanced instrument and platform arrays.

Diversity and Activity of Diazotrophs in Great Barrier Reef Surface Waters.

PubMed

Messer, Lauren F; Brown, Mark V; Furnas, Miles J; Carney, Richard L; McKinnon, A D; Seymour, Justin R

2017-01-01

Discrepancies between bioavailable nitrogen (N) concentrations and phytoplankton growth rates in the oligotrophic waters of the Great Barrier Reef (GBR) suggest that undetermined N sources must play a significant role in supporting primary productivity. One such source could be biological dinitrogen (N 2 ) fixation through the activity of "diazotrophic" bacterioplankton. Here, we investigated N 2 fixation and diazotroph community composition over 10° S of latitude within GBR surface waters. Qualitative N 2 fixation rates were found to be variable across the GBR but were relatively high in coastal, inner and outer GBR waters, reaching 68 nmol L -1 d -1 . Diazotroph assemblages, identified by amplicon sequencing of the nifH gene, were dominated by the cyanobacterium Trichodesmium erythraeum , γ-proteobacteria from the Gamma A clade, and δ-proteobacterial phylotypes related to sulfate-reducing genera. However, diazotroph communities exhibited significant spatial heterogeneity, correlated with shifts in dissolved inorganic nutrient concentrations. Specifically, heterotrophic diazotrophs generally increased in relative abundance with increasing concentrations of phosphate and N, while Trichodesmium was proportionally more abundant when concentrations of these nutrients were low. This study provides the first in-depth characterization of diazotroph community composition and N 2 fixation dynamics within the oligotrophic, N-limited surface waters of the GBR. Our observations highlight the need to re-evaluate N cycling dynamics within oligotrophic coral reef systems, to include diverse N 2 fixing assemblages as a potentially significant source of dissolved N within the water column.

Organochlorine-associated immunosuppression in prefledgling Caspian terns and herring gulls from the Great Lakes: an ecoepidemiological study.

PubMed Central

Grasman, K A; Fox, G A; Scanlon, P F; Ludwig, J P

1996-01-01

The objectives of study were to determine whether contaminant-associated immunosuppression occurs in prefledgling herring gulls and Caspian terns from the Great Lakes and to evaluate immunological biomarkers for monitoring health effects in wild birds. During 1992 to 1994, immunological responses and related variables were measured in prefledgling chicks at colonies distributed across a broad gradient of organochlorine contamination (primarily polychlorinated biphenyls), which was measured in eggs. The phytohemagglutinin skin test was used to assess T-lymphocyte function. In both species, there was a strong exposure-response relationship between organochlorines and suppressed T-cell-mediated immunity. Suppression was most severe (30-45%) in colonies in Lake Ontario (1992) and Saginaw Bay (1992-1994) for both species and in western Lake Erie (1992) for herring gulls. Both species exhibited biologically significant differences among sites in anti-sheep red blood cells antibody titers, but consistent exposure-response relationships with organochlorines were not observed. In Caspian terns and, to a lesser degree, in herring gulls, there was an exposure-response relationship between organochlorines and reduced plasma retinol (vitamin A). In 1992, altered White blood cell numbers were associated with elevated organochlorine concentrations in Caspian terns but not herring gulls. The immunological and hematological biomarkers used in this study revealed contaminant-associated health effects in wild birds. An epidemiological analysis strongly supported the hypothesis that suppression of T-cell-mediated immunity was associated with high perinatal exposure to persistent organochlorine contaminants. PMID:8880006

Aquatic insect ecophysiological traits reveal phylogenetically based differences in dissolved cadmium susceptibility.

PubMed

Buchwalter, David B; Cain, Daniel J; Martin, Caitrin A; Xie, Lingtian; Luoma, Samuel N; Garland, Theodore

2008-06-17

We used a phylogenetically based comparative approach to evaluate the potential for physiological studies to reveal patterns of diversity in traits related to susceptibility to an environmental stressor, the trace metal cadmium (Cd). Physiological traits related to Cd bioaccumulation, compartmentalization, and ultimately susceptibility were measured in 21 aquatic insect species representing the orders Ephemeroptera, Plecoptera, and Trichoptera. We mapped these experimentally derived physiological traits onto a phylogeny and quantified the tendency for related species to be similar (phylogenetic signal). All traits related to Cd bioaccumulation and susceptibility exhibited statistically significant phylogenetic signal, although the signal strength varied among traits. Conventional and phylogenetically based regression models were compared, revealing great variability within orders but consistent, strong differences among insect families. Uptake and elimination rate constants were positively correlated among species, but only when effects of body size and phylogeny were incorporated in the analysis. Together, uptake and elimination rates predicted dramatic Cd bioaccumulation differences among species that agreed with field-based measurements. We discovered a potential tradeoff between the ability to eliminate Cd and the ability to detoxify it across species, particularly mayflies. The best-fit regression models were driven by phylogenetic parameters (especially differences among families) rather than functional traits, suggesting that it may eventually be possible to predict a taxon's physiological performance based on its phylogenetic position, provided adequate physiological information is available for close relatives. There appears to be great potential for evolutionary physiological approaches to augment our understanding of insect responses to environmental stressors in nature.

Aquatic insect ecophysiological traits reveal phylogenetically based differences in dissolved cadmium susceptibility

PubMed Central

Buchwalter, David B.; Cain, Daniel J.; Martin, Caitrin A.; Xie, Lingtian; Luoma, Samuel N.; Garland, Theodore

2008-01-01

We used a phylogenetically based comparative approach to evaluate the potential for physiological studies to reveal patterns of diversity in traits related to susceptibility to an environmental stressor, the trace metal cadmium (Cd). Physiological traits related to Cd bioaccumulation, compartmentalization, and ultimately susceptibility were measured in 21 aquatic insect species representing the orders Ephemeroptera, Plecoptera, and Trichoptera. We mapped these experimentally derived physiological traits onto a phylogeny and quantified the tendency for related species to be similar (phylogenetic signal). All traits related to Cd bioaccumulation and susceptibility exhibited statistically significant phylogenetic signal, although the signal strength varied among traits. Conventional and phylogenetically based regression models were compared, revealing great variability within orders but consistent, strong differences among insect families. Uptake and elimination rate constants were positively correlated among species, but only when effects of body size and phylogeny were incorporated in the analysis. Together, uptake and elimination rates predicted dramatic Cd bioaccumulation differences among species that agreed with field-based measurements. We discovered a potential tradeoff between the ability to eliminate Cd and the ability to detoxify it across species, particularly mayflies. The best-fit regression models were driven by phylogenetic parameters (especially differences among families) rather than functional traits, suggesting that it may eventually be possible to predict a taxon's physiological performance based on its phylogenetic position, provided adequate physiological information is available for close relatives. There appears to be great potential for evolutionary physiological approaches to augment our understanding of insect responses to environmental stressors in nature. PMID:18559853

Analysis of variability in the burst oscillations of the accreting millisecond pulsar XTE J1814-338

NASA Technical Reports Server (NTRS)

Watts, Anna L.; Strohmayer, Tod E.; Markwardt, Craig B.

2005-01-01

The accreting millisecond pulsar XTE J1814-338 exhibits oscillations at the known spin frequency during Type I X-ray bursts. The properties of the burst oscillations reflect the nature of the thermal asymmetry on the stellar surface. We present an analysis of the variability of the burst oscillations of this source, focusing on three characteristics: fractional amplitude, harmonic content and frequency. Fractional amplitude and harmonic content constrain the size, shape and position of the emitting region, whilst variations in frequency indicate motion of the emitting region on the neutron star surface. We examine both long-term variability over the course of the outburst, and short-term variability during the bursts. For most of the bursts, fractional amplitude is consistent with that of the accretion pulsations, implying a low degree of fuel spread. There is however a population of bursts whose fractional amplitudes are substantially lower, implying a higher degree of fuel spread, possibly forced by the explosive burning front of a precursor burst. For the first harmonic, substantial differences between the burst and accretion pulsations suggest that hotspot geometry is not the only mechanism giving rise to harmonic content in the latter. Fractional amplitude variability during the bursts is low; we can only rule out the hypothesis that the fractional amplitude remains constant at the l(sigma) level for bursts that do not exhibit photospheric radius expansion (PRE). There are no significant variations in frequency in any of the bursts except for the one burst that exhibits PRE. This burst exhibits a highly significant but small (= 0.1Hz) drop in frequency in the burst rise. The timescale of the frequency shift is slower than simple burning layer expansion models predict, suggesting that other mechanisms may be at work.

Extraversion and cardiovascular responses to recurrent social stress: Effect of stress intensity.

PubMed

Lü, Wei; Xing, Wanying; Hughes, Brian M; Wang, Zhenhong

2017-10-28

The present study sought to establish whether the effects of extraversion on cardiovascular responses to recurrent social stress are contingent on stress intensity. A 2×5×1 mixed-factorial experiment was conducted, with social stress intensity as a between-subject variable, study phase as a within-subject variable, extraversion as a continuous independent variable, and cardiovascular parameter (HR, SBP, DBP, or RSA) as a dependent variable. Extraversion (NEO-FFI), subjective stress, and physiological stress were measured in 166 undergraduate students randomly assigned to undergo moderate (n=82) or high-intensity (n=84) social stress (a public speaking task with different levels of social evaluation). All participants underwent continuous physiological monitoring while facing two consecutive stress exposures distributed across five laboratory phases: baseline, stress exposure 1, post-stress 1, stress exposure 2, post-stress 2. Results indicated that under moderate-intensity social stress, participants higher on extraversion exhibited lesser HR reactivity to stress than participants lower on extraversion, while under high-intensity social stress, they exhibited greater HR, SBP, DBP and RSA reactivity. Under both moderate- and high-intensity social stress, participants higher on extraversion exhibited pronounced SBP and DBP response adaptation to repeated stress, and showed either better degree of HR recovery or greater amount of SBP and DBP recovery after stress. These findings suggest that individuals higher on extraversion exhibit physiological flexibility to cope with social challenges and benefit from adaptive cardiovascular responses. Copyright © 2017 Elsevier B.V. All rights reserved.

Awesome Universe: an exhibition with images that showcase celestial objects as seen by ESO's observatories and associated activities

NASA Astrophysics Data System (ADS)

Marin-Farrona, A. M.

2015-05-01

In September 2013, an ESO exhibition was shown in Santander: ``Awesome Universe -- the Cosmos through the eyes of the European Southern Observatory". Around the exhibition, were proposed several activities: guide tours for children, younger and adults, workshops, film projections... In this way, the exhibition was visited by more than two thousand persons. We must keep in mind that Santander is a small city and its population does not usually take part in outreach activity. With this contribution, we want to teach the way in which it is possible to take advantage of science exhibitions. It made possible to show stunning images that showcase celestial objects as seen by ESO's observatories to the great majority of Santander population, and to awaken their interest in or enthusiasm for science.

30 CFR 250.1610 - Blowout preventer systems and system components.

Code of Federal Regulations, 2010 CFR

2010-07-01

... equipment subject to well and/or pump pressure shall have a rated working pressure at least as great as the... manifold with a pressure rating at least as great as the rated working pressure of the ram-type BOP's..., the BOP stack shall be equipped with conventional and/or variable-bore pipe rams to provide either of...

30 CFR 250.1610 - Blowout preventer systems and system components.

Code of Federal Regulations, 2011 CFR

2011-07-01

... pressure at least as great as the rated working pressure of the ram-type BOP's or as otherwise approved by..., and including, the choke manifold with a pressure rating at least as great as the rated working...-string operations, the BOP stack shall be equipped with conventional and/or variable-bore pipe rams to...

30 CFR 250.1610 - Blowout preventer systems and system components.

Code of Federal Regulations, 2014 CFR

2014-07-01

... equipment subject to well and/or pump pressure shall have a rated working pressure at least as great as the... manifold with a pressure rating at least as great as the rated working pressure of the ram-type BOP's..., the BOP stack shall be equipped with conventional and/or variable-bore pipe rams to provide either of...

30 CFR 250.1610 - Blowout preventer systems and system components.

Code of Federal Regulations, 2012 CFR

2012-07-01

... equipment subject to well and/or pump pressure shall have a rated working pressure at least as great as the... manifold with a pressure rating at least as great as the rated working pressure of the ram-type BOP's..., the BOP stack shall be equipped with conventional and/or variable-bore pipe rams to provide either of...

30 CFR 250.1610 - Blowout preventer systems and system components.

Code of Federal Regulations, 2013 CFR

2013-07-01

... equipment subject to well and/or pump pressure shall have a rated working pressure at least as great as the... manifold with a pressure rating at least as great as the rated working pressure of the ram-type BOP's..., the BOP stack shall be equipped with conventional and/or variable-bore pipe rams to provide either of...

Pathogenic variability of individuals and populations of cucurbit powdery mildew–great confusion and great mystery, or why we still need the classical phytopathology.

USDA-ARS?s Scientific Manuscript database

Golovinomyces cichoracearum and Podosphaera xanthii (family Erysiphales) are considered the most important species causing cucurbit powdery mildew (CPM), a serious disease of field and greenhouse cucurbits. Podosphaera xanthii (Px) is common in subtropical and tropical areas and in greenhouses in te...

HEART RATE VARIABILITY IN RODENTS — USES AND CAVEATS IN TOXICOLOGICAL STUDIES

EPA Science Inventory

Heart rate variability (HRV) is a measure of cardiac pacing dynamics that has recently garnered a great deal of interest in environmental health studies. While the use of these measures has become popular, much uncertainty remains in the interpretation of results, both in terms ...

Sedimentation in the chaparral: how do you handle unusual events?

Treesearch

Raymond M. Rice

1982-01-01

Abstract - Processes of erosion and sedimentation in steep chaparral drainage basins of southern California are described. The word ""hyperschedastic"" is coined to describe the sedimentation regime which is highly variable because of the interaction of marginally stable drainage basins, great variability in storm inputs, and the random occurrence...

Variables Impacting Dispositional Empathy in Doctoral Psychology Students

ERIC Educational Resources Information Center

Micheli, Amelia C.

2014-01-01

The purpose of this study was to explore variables impacting dispositional empathy in doctoral psychology students. While there is a great deal of research regarding empathy in practicing psychologists and mental health professionals, little is known about empathy in psychology trainees. This is especially surprising given the importance of…

How Students Circumvent Problem-Solving Strategies that Require Greater Cognitive Complexity.

ERIC Educational Resources Information Center

Niaz, Mansoor

1996-01-01

Analyzes the great diversity in problem-solving strategies used by students in solving a chemistry problem and discusses the relationship between these variables and different cognitive variables. Concludes that students try to circumvent certain problem-solving strategies by adapting flexible and stylistic innovations that render the cognitive…

Flexible nanopillar-based electrochemical sensors for genetic detection of foodborne pathogens

NASA Astrophysics Data System (ADS)

Park, Yoo Min; Lim, Sun Young; Jeong, Soon Woo; Song, Younseong; Bae, Nam Ho; Hong, Seok Bok; Choi, Bong Gill; Lee, Seok Jae; Lee, Kyoung G.

2018-06-01

Flexible and highly ordered nanopillar arrayed electrodes have brought great interest for many electrochemical applications, especially to the biosensors, because of its unique mechanical and topological properties. Herein, we report an advanced method to fabricate highly ordered nanopillar electrodes produced by soft-/photo-lithography and metal evaporation. The highly ordered nanopillar array exhibited the superior electrochemical and mechanical properties in regard with the wide space to response with electrolytes, enabling the sensitive analysis. As-prepared gold and silver electrodes on nanopillar arrays exhibit great and stable electrochemical performance to detect the amplified gene from foodborne pathogen of Escherichia coli O157:H7. Additionally, lightweight, flexible, and USB-connectable nanopillar-based electrochemical sensor platform improves the connectivity, portability, and sensitivity. Moreover, we successfully confirm the performance of genetic analysis using real food, specially designed intercalator, and amplified gene from foodborne pathogens with high reproducibility (6% standard deviation) and sensitivity (10 × 1.01 CFU) within 25 s based on the square wave voltammetry principle. This study confirmed excellent mechanical and chemical characteristics of nanopillar electrodes have a great and considerable electrochemical activity to apply as genetic biosensor platform in the fields of point-of-care testing (POCT).

Protest and Innovation in Italy--The Great Exhibitions

ERIC Educational Resources Information Center

Costa de Beauregard, Pascaline

1976-01-01

Describes efforts to instill new life into the major agencies concerned with promotion of contemporary art, and emphasizes the need to de-politicize the major art expositions (the Venice Biennale, Rome Quadriennale, and Milan Triennale). (Author/RW)

Photodeposited Pd Nanoparticles with Disordered Structure for Phenylacetylene Semihydrogenation

PubMed Central

Fan, Qining; He, Sha; Hao, Lin; Liu, Xin; Zhu, Yue; Xu, Sailong; Zhang, Fazhi

2017-01-01

Developing effective heterogeneous metal catalysts with high selectivity and satisfactory activity for chemoselective hydrogenation of alkyne to alkene is of great importance in the chemical industry. Herein, we report our efforts to fabricate TiO2-supported Pd catalysts by a photodeposition method at room temperature for phenylacetylene semihydrogenation to styrene. The resulting Pd/TiO2 catalyst, possessing smaller Pd ensembles with ambiguous lattice fringes and more low coordination Pd sites, exhibits higher styrene selectivity compared to two contrastive Pd/TiO2 samples with larger ensembles and well-organized crystal structure fabricated by deposition-precipitation or photodeposition with subsequent thermal treatment at 300 °C. The sample derived from photodeposition exhibits greatly slow styrene hydrogenation in kinetic evaluation because the disordered structure of Pd particles in photodeposited Pd/TiO2 may prevent the formation of β-hydride phases and probably produce more surface H atoms, which may favor high styrene selectivity. PMID:28176843

Photodeposited Pd Nanoparticles with Disordered Structure for Phenylacetylene Semihydrogenation

NASA Astrophysics Data System (ADS)

Fan, Qining; He, Sha; Hao, Lin; Liu, Xin; Zhu, Yue; Xu, Sailong; Zhang, Fazhi

2017-02-01

Developing effective heterogeneous metal catalysts with high selectivity and satisfactory activity for chemoselective hydrogenation of alkyne to alkene is of great importance in the chemical industry. Herein, we report our efforts to fabricate TiO2-supported Pd catalysts by a photodeposition method at room temperature for phenylacetylene semihydrogenation to styrene. The resulting Pd/TiO2 catalyst, possessing smaller Pd ensembles with ambiguous lattice fringes and more low coordination Pd sites, exhibits higher styrene selectivity compared to two contrastive Pd/TiO2 samples with larger ensembles and well-organized crystal structure fabricated by deposition-precipitation or photodeposition with subsequent thermal treatment at 300 °C. The sample derived from photodeposition exhibits greatly slow styrene hydrogenation in kinetic evaluation because the disordered structure of Pd particles in photodeposited Pd/TiO2 may prevent the formation of β-hydride phases and probably produce more surface H atoms, which may favor high styrene selectivity.

Wood-Derived Ultrathin Carbon Nanofiber Aerogels.

PubMed

Li, Si-Cheng; Hu, Bi-Cheng; Ding, Yan-Wei; Liang, Hai-Wei; Li, Chao; Yu, Zi-You; Wu, Zhen-Yu; Chen, Wen-Shuai; Yu, Shu-Hong

2018-06-11

Carbon aerogels with 3D networks of interconnected nanometer-sized particles exhibit fascinating physical properties and show great application potential. Efficient and sustainable methods are required to produce high-performance carbon aerogels on a large scale to boost their practical applications. An economical and sustainable method is now developed for the synthesis of ultrathin carbon nanofiber (CNF) aerogels from the wood-based nanofibrillated cellulose (NFC) aerogels via a catalytic pyrolysis process, which guarantees high carbon residual and well maintenance of the nanofibrous morphology during thermal decomposition of the NFC aerogels. The wood-derived CNF aerogels exhibit excellent electrical conductivity, a large surface area, and potential as a binder-free electrode material for supercapacitors. The results suggest great promise in developing new families of carbon aerogels based on the controlled pyrolysis of economical and sustainable nanostructured precursors. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Polybrominated diphenyl ethers (PBDEs) in Great Lakes fish: Levels, patterns, trends and implications for human exposure.

PubMed

Gandhi, Nilima; Gewurtz, Sarah B; Drouillard, Ken G; Kolic, Terry; MacPherson, Karen; Reiner, Eric J; Bhavsar, Satyendra P

2017-01-15

Levels of polybrominated diphenyl ethers (PBDEs) were measured in edible portions of Great Lakes fish, with the goal of examining patterns/trends and evaluating implications for human exposure. A total of 470 fillets of 18 fish species collected from various parts of the Canadian waters of the Great Lakes between 2006 and 2013 were analyzed for 17 (expanded to 33 in 2009) PBDEs. For a limited number of species, fillet to whole body and fillet to eggs PBDEs were compared to examine pattern and concentration among tissue types. Levels and patterns of PBDEs varied dramatically within and among the 18 fish species. Bottom dwelling Common Carp (and White Sucker) exhibited the highest ∑PBDE levels (27-71ng/g). Lake Trout and Lake Whitefish from Lake Superior had higher levels than those from the other Great Lakes; otherwise the spatial trend was Lake Ontario≫Erie~Huron~Superior. The measured levels would result in restriction on consumption of only Common Carp from the Toronto waterfront area, which is in proximity to the most urbanised region on the Canadian side of the basin. Deca-BDE was the major congener in panfish, while BDE-47 was the major congener in top predators and its contribution to ∑PBDE increased with the contamination. Although ∑PBDE was related to fish length and lipid content when all measurements were pooled, the relationships were variable for individual sampling events (species/location/year). Whole body ∑PBDE for bottom dweller Brown Bullhead and Common Carp were 2.6-4.9 times greater and egg ∑PBDE for four fatty Salmon/Trout species were same to 6.5 times greater than the corresponding fillet concentrations. Levels of major lower brominated PBDEs appear to have declined in fish fillets by 46-74% between 2006/07 and 2012. Although PBDE in existing consumer items will remain in-use for a while, it will likely not result in appreciable accumulation of PBDEs in fish. Based on an overall assessment, regular monitoring of PBDEs in Great Lake fish can be replaced with targeted surveillance and focus can be shifted to other in-use flame retardants. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

Modern multicore and manycore architectures: Modelling, optimisation and benchmarking a multiblock CFD code

NASA Astrophysics Data System (ADS)

Hadade, Ioan; di Mare, Luca

2016-08-01

Modern multicore and manycore processors exhibit multiple levels of parallelism through a wide range of architectural features such as SIMD for data parallel execution or threads for core parallelism. The exploitation of multi-level parallelism is therefore crucial for achieving superior performance on current and future processors. This paper presents the performance tuning of a multiblock CFD solver on Intel SandyBridge and Haswell multicore CPUs and the Intel Xeon Phi Knights Corner coprocessor. Code optimisations have been applied on two computational kernels exhibiting different computational patterns: the update of flow variables and the evaluation of the Roe numerical fluxes. We discuss at great length the code transformations required for achieving efficient SIMD computations for both kernels across the selected devices including SIMD shuffles and transpositions for flux stencil computations and global memory transformations. Core parallelism is expressed through threading based on a number of domain decomposition techniques together with optimisations pertaining to alleviating NUMA effects found in multi-socket compute nodes. Results are correlated with the Roofline performance model in order to assert their efficiency for each distinct architecture. We report significant speedups for single thread execution across both kernels: 2-5X on the multicore CPUs and 14-23X on the Xeon Phi coprocessor. Computations at full node and chip concurrency deliver a factor of three speedup on the multicore processors and up to 24X on the Xeon Phi manycore coprocessor.

Mesoscale variation in the photophysiology of the reef building coral Pocillopora damicornis along an environmental gradient

NASA Astrophysics Data System (ADS)

Cooper, Timothy F.; Ulstrup, Karin E.

2009-06-01

Spatial variation in the photophysiology of symbiotic dinoflagellates (zooxanthellae) of the scleractinian coral Pocillopora damicornis was examined along an environmental gradient in the Whitsunday Islands (Great Barrier Reef) at two depths (3 m and 6 m). Chlorophyll a fluorescence of photosystem II (PSII) and PAR-absorptivity measurements were conducted using an Imaging-PAM (pulse-amplitude-modulation) fluorometer. Most photophysiological parameters correlated with changes in environmental conditions quantified by differences in water quality along the gradient. For example, maximum quantum yield ( Fv/ Fm) increased and PAR-absorptivity decreased as water quality improved along the gradient from nearshore reefs (low irradiance, elevated nutrients and sediments) to outer islands (high irradiance, low nutrients and sediments). For apparent photosynthetic rate (PS max) and minimum saturating irradiance ( Ek), the direction of change differed depending on sampling depth, suggesting that different mechanisms of photo-acclimatisation operated between shallow and deep corals. Deep corals conformed to typical patterns of light/shade acclimatisation whereas shallow corals exhibited reduced PS max and Ek with improving water quality coinciding with greater heat dissipation (NPQ 241). Furthermore, deep corals on nearshore reefs exhibited elevated Q241 in comparison to outer islands possibly due to effects of sedimentation and/or pollutants rather than irradiance. These results highlight the importance of mesoscale sampling to obtain useful estimates of the variability of photophysiological parameters, particularly if such measures are to be used as bioindicators of the condition of coral reefs.

KSC-04PD-2201

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Employees at KSC stroll among several tents featuring vendors exhibits of safety- and health-related products. The exhibits were part of Spaceport Super Safety and Health Day, which also featured presentations by guest speakers Dr. Pamela Peeke, Navy Com. Stephen E. Iwanowicz, NASAs Dr. Kristine Calderon and Olympic-great Bruce Jenner. Vendors exhibits were set up in the parking areas outside the Vehicle Assembly Building (seen here) and the O&C Building. The annual event was initiated at KSC in 1998 to increase awareness of the importance of safety and health among the government and contractor workforce. The theme for this years event was Safety and Health: A Winning Combination.

Extremes in East African hydroclimate and links to Indo-Pacific variability on interannual to decadal timescales

NASA Astrophysics Data System (ADS)

Ummenhofer, Caroline C.; Kulüke, Marco; Tierney, Jessica E.

2018-04-01

East African hydroclimate exhibits considerable variability across a range of timescales, with implications for its population that depends on the region's two rainy seasons. Recent work demonstrated that current state-of-the-art climate models consistently underestimate the long rains in boreal spring over the Horn of Africa while overestimating the short rains in autumn. This inability to represent the seasonal cycle makes it problematic for climate models to project changes in East African precipitation. Here we consider whether this bias also has implications for understanding interannual and decadal variability in the East African long and short rains. Using a consistent framework with an unforced multi-century global coupled climate model simulation, the role of Indo-Pacific variability for East African rainfall is compared across timescales and related to observations. The dominant driver of East African rainfall anomalies critically depends on the timescale under consideration: Interannual variations in East African hydroclimate coincide with significant sea surface temperature (SST) anomalies across the Indo-Pacific, including those associated with the El Niño-Southern Oscillation (ENSO) in the eastern Pacific, and are linked to changes in the Walker circulation, regional winds and vertical velocities over East Africa. Prolonged drought/pluvial periods in contrast exhibit anomalous SST predominantly in the Indian Ocean and Indo-Pacific warm pool (IPWP) region, while eastern Pacific anomalies are insignificant. We assessed dominant frequencies in Indo-Pacific SST and found the eastern equatorial Pacific dominated by higher-frequency variability in the ENSO band, while the tropical Indian Ocean and IPWP exhibit lower-frequency variability beyond 10 years. This is consistent with the different contribution to regional precipitation anomalies for the eastern Pacific versus Indian Ocean and IPWP on interannual and decadal timescales, respectively. In the model, the dominant low-frequency signal seen in the observations in the Indo-Pacific is not well-represented as it instead exhibits overly strong variability on subdecadal timescales. The overly strong ENSO-teleconnection likely contributes to the overestimated role of the short rains in the seasonal cycle in the model compared to observations.

Development of dopant-free conductive bioelastomers

PubMed Central

Xu, Cancan; Huang, Yihui; Yepez, Gerardo; Wei, Zi; Liu, Fuqiang; Bugarin, Alejandro; Tang, Liping; Hong, Yi

2016-01-01

Conductive biodegradable materials are of great interest for various biomedical applications, such as tissue repair and bioelectronics. They generally consist of multiple components, including biodegradable polymer/non-degradable conductive polymer/dopant, biodegradable conductive polymer/dopant or biodegradable polymer/non-degradable inorganic additives. The dopants or additives induce material instability that can be complex and possibly toxic. Material softness and elasticity are also highly expected for soft tissue repair and soft electronics. To address these concerns, we designed a unicomponent dopant-free conductive polyurethane elastomer (DCPU) by chemically linking biodegradable segments, conductive segments, and dopant molecules into one polymer chain. The DCPU films which had robust mechanical properties with high elasticity and conductivity can be degraded enzymatically and by hydrolysis. It exhibited great electrical stability in physiological environment with charge. Mouse 3T3 fibroblasts survived and proliferated on these films exhibiting good cytocompatibility. Polymer degradation products were non-toxic. DCPU could also be processed into a porous scaffold and in an in vivo subcutaneous implantation model, exhibited good tissue compatibility with extensive cell infiltration over 2 weeks. Such biodegradable DCPU with good flexibility and elasticity, processability, and electrical stability may find broad applications for tissue repair and soft/stretchable/wearable bioelectronics. PMID:27686216

Piezoelectric Active Humidity Sensors Based on Lead-Free NaNbO₃ Piezoelectric Nanofibers.

PubMed

Gu, Li; Zhou, Di; Cao, Jun Cheng

2016-06-07

The development of micro-/nano-scaled energy harvesters and the self-powered sensor system has attracted great attention due to the miniaturization and integration of the micro-device. In this work, lead-free NaNbO₃ piezoelectric nanofibers with a monoclinic perovskite structure were synthesized by the far-field electrospinning method. The flexible active humidity sensors were fabricated by transferring the nanofibers from silicon to a soft polymer substrate. The sensors exhibited outstanding piezoelectric energy-harvesting performance with output voltage up to 2 V during the vibration process. The output voltage generated by the NaNbO₃ sensors exhibited a negative correlation with the environmental humidity varying from 5% to 80%, where the peak-to-peak value of the output voltage generated by the sensors decreased from 0.40 to 0.07 V. The sensor also exhibited a short response time, good selectively against ethanol steam, and great temperature stability. The piezoelectric active humidity sensing property could be attributed to the increased leakage current in the NaNbO₃ nanofibers, which was generated due to proton hopping among the H₃O⁺ groups in the absorbed H₂O layers under the driving force of the piezoelectric potential.

Two-D results on human operator perception

NASA Technical Reports Server (NTRS)

Siapkara, A. A.; Sheridan, T. B.

1981-01-01

The application of multidimensional scaling methodology in human factors engineering is presented. The nonorthogonality of internally perceived task variables is exhibited for first and second order plants with both dependent and independent task variables. Directions of operator preference are shown for actual performance, pilot opinion rating, and subjective measures of fatigue, adaptability, and system recognition. Improvement of performance in second order systems is exhibited by the use of bang-bang feedback information. Dissimilarity measures for system comparison are suggested in order to account for human operator rotations and subjective sense of time.

Population genetic structure of a California endemic Branchiopod, Branchinecta sandiegonensis

USGS Publications Warehouse

Davies, Cathleen P.; Simovich, Marie A.; Hathaway, Stacie A.

1997-01-01

Branchinecta sandiegonensis (Crustacea: Anostraca) is a narrow range endemic fairy shrimp discontinuously distributed in ephemeral pools on coastal mesas in San Diego County, USA. Ten populations across the range of the species were subjected to allozyme analysis for eleven loci. The species exhibits low variability (P95 =9.1–45.5) and one third of the loci tested did not conform to Hardy-Weinberg equilibrium expectations. The species also exhibited a high degree of genetic differentiation between populations. F ST values (fixation index) for most pairs of populations were above 0.25 (0.036–0.889).Low genetic variability and high genetic structure may result from low gene flow and founder effects due to habitat fragmentation and the lack of potential vectors for cyst dispersal. The unpredictable rainfall of the region also creates potential for variable population sizes which could affect structure and variability.

Visualization of the variability of 3D statistical shape models by animation.

PubMed

Lamecker, Hans; Seebass, Martin; Lange, Thomas; Hege, Hans-Christian; Deuflhard, Peter

2004-01-01

Models of the 3D shape of anatomical objects and the knowledge about their statistical variability are of great benefit in many computer assisted medical applications like images analysis, therapy or surgery planning. Statistical model of shapes have successfully been applied to automate the task of image segmentation. The generation of 3D statistical shape models requires the identification of corresponding points on two shapes. This remains a difficult problem, especially for shapes of complicated topology. In order to interpret and validate variations encoded in a statistical shape model, visual inspection is of great importance. This work describes the generation and interpretation of statistical shape models of the liver and the pelvic bone.

Drivers of pCO2 variability in two contrasting coral reef lagoons: The influence of submarine groundwater discharge

NASA Astrophysics Data System (ADS)

Cyronak, Tyler; Santos, Isaac R.; Erler, Dirk V.; Maher, Damien T.; Eyre, Bradley D.

2014-04-01

The impact of groundwater on pCO2 variability was assessed in two coral reef lagoons with distinct drivers of submarine groundwater discharge (SGD). Diel variability of pCO2 in the two ecosystems was explained by a combination of biological drivers and SGD inputs. In Rarotonga, a South Pacific volcanic island, 222Rn-derived SGD was driven primarily by a steep terrestrial hydraulic gradient, and the water column was influenced by the high pCO2 (5501 µatm) of the fresh groundwater. In Heron Island, a Great Barrier Reef coral cay, SGD was dominated by seawater recirculation through the sediments (i.e., tidal pumping), and pCO2 was mainly impacted through the stimulation of biological processes. The Rarotonga water column had a higher average pCO2 (549 µatm) than Heron Island (471 µatm). However, pCO2 exhibited a greater diel range in Heron Island (778 µatm) than in Rarotonga (507 µatm). The Rarotonga water column received 29.0 ± 8.2 mmol free-CO2 m-2 d-1 from SGD, while the Heron Island water column received 12.1 ± 4.2 mmol free-CO2 m-2 d-1. Over the course of this study, both systems were sources of CO2 to the atmosphere with SGD-derived free-CO2 most likely contributing a large portion to the air-sea CO2 flux. Studies measuring the carbon chemistry of coral reefs (e.g., metabolism and calcification rates) may need to consider the effects of groundwater inputs on water column carbonate chemistry. Local drivers of coral reef carbonate chemistry such as SGD may offer more approachable management solutions to mitigating the effects of ocean acidification on coral reefs.

Multi-decadal Variability of the Indian Monsoon Rainfall for the last 14 kyr

NASA Astrophysics Data System (ADS)

Panmei, C.; Pothuri, D.

2017-12-01

Precise reconstruction of Indian monsoon fluctuation events and variability trends over the last 14 kyr has great implications for understanding the dynamics and possible forcing/feedback mechanisms associated with it. We have carried out high-resolution Indian monsoon variability studies of multi-decadal to sub-centennial timescales for the past 14 kyr through oxygen isotopes and Mg/Ca-derived sea surface temperatures (SST) from a western Bay of Bengal sediment core MD 161/17, using planktonic foraminifera Globigerinoides ruber. Indian summer monsoon (ISM) intensity was low during the Younger Dryas (YD) as evidenced by enriched δ18Osw coincides with a striking warming of 1.5°C. We observed ISM intensification from 12-9 kyr, followed by a milder period from 9-7.2 kyr. ISM gradually weakened from 7.2-2.5 kyr, after which there were two very prominent shifts in both ISM and SST; abrupt decrease at 2.4 kyr and increase at 1.4 kyr for ISM, while SST exhibited opposite trend. The contrasting trend continued from 1.4 kyr to the present wherein ISM precipitation has been decreasing and SST has been increasing. In addition, spectral analysis was done using Redfit and the ISM precipitation records reveal statistically significant periodicities at 2118, 411, 344, 144, 101 and 90 yrs. Furthermore, we compared our results with other existing records from the Northern Indian Ocean and adjacent regions, and found that the records share similarities suggesting regional dynamics being expressed coherently. Our results suggest that ISM precipitation and warming/cooling of the Northern Indian Ocean is directly associated with the southward/northward shift of the Intertropical Convergence Zone, which in turn is influenced by Atlantic Meridional Overturning Circulation, North Atlantic climate, and solar insolation interplaying differently at different timescales.

Seasonal Evolution and Interannual Variability of the Local Solar Energy Absorbed by the Arctic Sea Ice-Ocean System

NASA Technical Reports Server (NTRS)

Perovich, Donald K.; Nghiem, Son V.; Markus, Thorsten; Schwieger, Axel

2007-01-01

The melt season of the Arctic sea ice cover is greatly affected by the partitioning of the incident solar radiation between reflection to the atmosphere and absorption in the ice and ocean. This partitioning exhibits a strong seasonal cycle and significant interannual variability. Data in the period 1998, 2000-2004 were analyzed in this study. Observations made during the 1997-1998 SHEBA (Surface HEat Budget of the Arctic Ocean) field experiment showed a strong seasonal dependence of the partitioning, dominated by a five-phase albedo evolution. QuikSCAT scatterometer data from the SHEBA region in 1999-2004 were used to further investigate solar partitioning in summer. The time series of scatterometer data were used to determine the onset of melt and the beginning of freezeup. This information was combined with SSM/I-derived ice concentration, TOVS-based estimates of incident solar irradiance, and SHEBA results to estimate the amount of solar energy absorbed in the ice-ocean system for these years. The average total solar energy absorbed in the ice-ocean system from April through September was 900 MJ m(sup -2). There was considerable interannual variability, with a range of 826 to 1044 MJ m(sup -2). The total amount of solar energy absorbed by the ice and ocean was strongly related to the date of melt onset, but only weakly related to the total duration of the melt season or the onset of freezeup. The timing of melt onset is significant because the incident solar energy is large and a change at this time propagates through the entire melt season, affecting the albedo every day throughout melt and freezeup.

US Drought-Heat Wave Relationships in Past Versus Current Climates

NASA Astrophysics Data System (ADS)

Cheng, L.; Hoerling, M. P.; Eischeid, J.; Liu, Z.

2017-12-01

This study explores the relationship between droughts and heat waves over various regions of the contiguous United States that are distinguished by so-called energy-limited versus water-limited climatologies. We first examine the regional sensitivity of heat waves to soil moisture variability under 19th century climate conditions, and then compare to sensitivities under current climate that has been subjected to human-induced change. Our approach involves application of the conditional statistical framework of vine copula. Vine copula is known for its flexibility in reproducing various dependence structures exhibited by climate variables. Here we highlight its feature for evaluating the importance of conditional relationships between variables and processes that capture underlying physical factors involved in their interdependence during drought/heat waves. Of particular interest is identifying changes in coupling strength between heat waves and land surface conditions that may yield more extreme events as a result of land surface feedbacks. We diagnose two equilibrium experiments a coupled climate model (CESM1), one subjected to Year-1850 external forcing and the other to Year-2000 radiative forcing. We calculate joint heat wave/drought relationships for each climate state, and also calculate their change as a result of external radiative forcing changes across this 150-yr period. Our results reveal no material change in the dependency between heat waves and droughts, aside from small increases in coupling strength over the Great Plains. Overall, hot U.S. summer droughts of 1850-vintage do not become hotter in the current climate -- aside from the warming contribution of long-term climate change, in CESM1. The detectability of changes in hotter droughts as a consequence of anthropogenic forced changes in this single effect, i.e. coupling strength between soil moisture and hot summer temperature, is judged to be low at this time.

Test--retest variability of Randot stereoacuity measures gathered in an unselected sample of UK primary school children.

PubMed

Adler, Paul; Scally, Andrew J; Barrett, Brendan T

2012-05-01

To determine the test-retest reliability of the Randot stereoacuity test when used as part of vision screening in schools. Randot stereoacuity (graded-circles) and logMAR visual acuity measures were gathered in an unselected sample of 139 children (aged 4-12, mean 8.1±2.1 years) in two schools. Randot testing was repeated on two occasions (average interval between successive tests 8 days, range: 1-21 days). Three Randot scores were obtained in 97.8% of children. Randot stereoacuity improved by an average of one plate (ie, one test level) on repeat testing but was little changed when tested on the third occasion. Within-subject variability was up to three test levels on repeat testing. When stereoacuity was categorised as 'fine', 'intermediate' or 'coarse', the greatest variability was found among younger children who exhibited 'intermediate' or 'coarse'/nil stereopsis on initial testing. Whereas 90.8% of children with 'fine' stereopsis (≤50 arc-seconds) on the first test exhibited 'fine' stereopsis on both subsequent tests, only ∼16% of children with 'intermediate' (>50 but ≤140 arc-seconds) or 'coarse'/nil (≥200 arc-seconds) stereoacuity on initial testing exhibited stable test results on repeat testing. Children exhibiting abnormal stereoacuity on initial testing are very likely to exhibit a normal result when retested. The value of a single, abnormal Randot graded-circles stereoacuity measure from school screening is therefore questionable.

Discrimination Enhancement with Transient Feature Analysis of a Graphene Chemical Sensor.

PubMed

Nallon, Eric C; Schnee, Vincent P; Bright, Collin J; Polcha, Michael P; Li, Qiliang

2016-01-19

A graphene chemical sensor is subjected to a set of structurally and chemically similar hydrocarbon compounds consisting of toluene, o-xylene, p-xylene, and mesitylene. The fractional change in resistance of the sensor upon exposure to these compounds exhibits a similar response magnitude among compounds, whereas large variation is observed within repetitions for each compound, causing a response overlap. Therefore, traditional features depending on maximum response change will cause confusion during further discrimination and classification analysis. More robust features that are less sensitive to concentration, sampling, and drift variability would provide higher quality information. In this work, we have explored the advantage of using transient-based exponential fitting coefficients to enhance the discrimination of similar compounds. The advantages of such feature analysis to discriminate each compound is evaluated using principle component analysis (PCA). In addition, machine learning-based classification algorithms were used to compare the prediction accuracies when using fitting coefficients as features. The additional features greatly enhanced the discrimination between compounds while performing PCA and also improved the prediction accuracy by 34% when using linear discrimination analysis.

Optimization the composition of sand-lime products modified of diabase aggregate

NASA Astrophysics Data System (ADS)

Komisarczyk, K.; Stępień, A.

2017-10-01

The problem of optimizing the composition of building materials is currently of great importance due to the increasing competitiveness and technological development in the construction industry. This phenomenon also applies to catalog sand-lime. The respective arrangement of individual components or their equivalents, and linking them with the main parameters of the composition of the mixture, i.e. The lime/sand/water should lead to the intended purpose. The introduction of sand-lime diabase aggregate is concluded with a positive effect of final products. The paper presents the results of optimization with the addition of diabase aggregate. The constant value was the amount of water, variable - the mass of the dry ingredients. The program of experimental studies was taken for 6 series of silicates made in industrial conditions. Final samples were tested for mechanical and physico-chemical expanding the analysis of the mercury intrusion porosimetry, SEM and XRD. The results show that, depending on the aggregate’s contribution, exhibit differences. The sample in an amount of 10% diabase aggregate the compressive strength was higher than in the case of reference sample, while modified samples absorbed less water.

Economic impact and market analysis of a special event: The Great New England Air Show

Treesearch

Rodney B. Warnick; David C. Bojanic; Atul Sheel; Apurv Mather; Deepak Ninan

2010-01-01

We conducted a post-event evaluation for the Great New England Air Show to assess its general economic impact and to refine economic estimates where possible. In addition to the standard economic impact variables, we examined travel distance, purchase decision involvement, event satisfaction, and frequency of attendance. Graphic mapping of event visitors' home ZIP...

Genecology and seed zones for tapertip onion in the US Great Basin

Treesearch

R. C. Johnson; Barbara C. Hellier; Ken W. Vance-Borland

2013-01-01

The choice of germplasm is critical for sustainable restoration, yet seed transfer guidelines are lacking for all but a few herbaceous species. Seed transfer zones based on genetic variability and climate were developed using tapertip onion (Allium acuminatum Hook.) collected in the Great Basin and surrounding areas in the United States. Bulbs from 53 locations were...

Added value from 576 years of tree-ring records in the prediction of the Great Salt Lake level

Treesearch

Robert R. Gillies; Oi-Yu Chung; S.-Y. Simon Wang; R. Justin DeRose; Yan Sun

2015-01-01

Predicting lake level fluctuations of the Great Salt Lake (GSL) in Utah - the largest terminal salt-water lake in the Western Hemisphere - is critical from many perspectives. The GSL integrates both climate and hydrological variations within the region and is particularly sensitive to low-frequency climate cycles. Since most hydroclimate variable records cover...

Optical photometric variable stars towards the Galactic H II region NGC 2282

NASA Astrophysics Data System (ADS)

Dutta, Somnath; Mondal, Soumen; Joshi, Santosh; Jose, Jessy; Das, Ramkrishna; Ghosh, Supriyo

2018-05-01

We report here CCD I-band time series photometry of a young (2-5 Myr) cluster NGC 2282, in order to identify and understand the variability of pre-main-sequence (PMS) stars. The I-band photometry, down to ˜20.5 mag, enables us to probe the variability towards the lower mass end (˜0.1 M⊙) of PMS stars. From the light curves of 1627 stars, we identified 62 new photometric variable candidates. Their association with the region was established from H α emission and infrared (IR) excess. Among 62 variables, 30 young variables exhibit H α emission, near-IR (NIR)/mid-IR (MIR) excess or both and are candidate members of the cluster. Out of 62 variables, 41 are periodic variables, with a rotation rate ranging from 0.2-7 d. The period distribution exhibits a median period at ˜1 d, as in many young clusters (e.g. NGC 2264, ONC, etc.), but it follows a unimodal distribution, unlike others that have bimodality, with slow rotators peaking at ˜6-8 d. To investigate the rotation-disc and variability-disc connection, we derived the NIR excess from Δ(I - K) and the MIR excess from Spitzer [3.6]-[4.5] μm data. No conclusive evidence of slow rotation with the presence of discs around stars and fast rotation for discless stars is obtained from our periodic variables. A clear increasing trend of the variability amplitude with IR excess is found for all variables.

Characterization of Ascochyta rabiei for population structure, mating type and pathogenic variability from Pakistan and United States

USDA-ARS?s Scientific Manuscript database

Chickpea production is greatly hampered by blight causing fungal pathogen Ascochyta rabiei (AR) in chickpea growing regions of the world. Genetic variability and mating type frequency of thirty-two AR isolates from six geographical regions of Pakistan were compared with a US-AR population. Pakistani...

An Evaluation of Observational Methods for Measuring Response to Classwide Intervention

ERIC Educational Resources Information Center

Briesch, Amy M.; Hemphill, Elizabeth M.; Volpe, Robert J.; Daniels, Brian

2015-01-01

Although there is much research to support the effectiveness of classwide interventions aimed at improving student engagement, there is also a great deal of variability in terms of how response to group-level intervention has been measured. The unfortunate consequence of this procedural variability is that it is difficult to determine whether…

GPA in Research Studies: An Invaluable but Neglected Opportunity

ERIC Educational Resources Information Center

Bacon, Donald R.; Bean, Beth

2006-01-01

Grade point average (GPA) often correlates highly with variables of interest to educational researchers and thus offers the potential to greatly increase the statistical power of their research studies. Yet this variable is often underused in marketing education research studies. The reliability and validity of the GPA are closely examined here in…

Trends and variability of daily temperature extremes during 1960-2012 in the Yangtze River Basin, China

USDA-ARS?s Scientific Manuscript database

The variability of temperature extremes has been the focus of attention during the past few decades, and may exert a great influence on the global hydrologic cycle and energy balance through thermal forcing. Based on daily minimum and maximum temperature observed by the China Meteorological Administ...

Variability in range cow mineral use is associated with season and daily high temperature in Northern Great Plains

USDA-ARS?s Scientific Manuscript database

Accurate assessment of mineral nutrition in range cattle is complicated by seasonal changes in diet mineral concentrations, shifting requirements and a lack of knowledge of seasonal mineral intake variability. This study was designed to evaluate variation in herd mineral intake, and individual cow m...

3D ground‐motion simulations of Mw 7 earthquakes on the Salt Lake City segment of the Wasatch fault zone: Variability of long‐period (T≥1  s) ground motions and sensitivity to kinematic rupture parameters

USGS Publications Warehouse

Moschetti, Morgan P.; Hartzell, Stephen; Ramirez-Guzman, Leonardo; Frankel, Arthur; Angster, Stephen J.; Stephenson, William J.

2017-01-01

We examine the variability of long‐period (T≥1  s) earthquake ground motions from 3D simulations of Mw 7 earthquakes on the Salt Lake City segment of the Wasatch fault zone, Utah, from a set of 96 rupture models with varying slip distributions, rupture speeds, slip velocities, and hypocenter locations. Earthquake ruptures were prescribed on a 3D fault representation that satisfies geologic constraints and maintained distinct strands for the Warm Springs and for the East Bench and Cottonwood faults. Response spectral accelerations (SA; 1.5–10 s; 5% damping) were measured, and average distance scaling was well fit by a simple functional form that depends on the near‐source intensity level SA0(T) and a corner distance Rc:SA(R,T)=SA0(T)(1+(R/Rc))−1. Period‐dependent hanging‐wall effects manifested and increased the ground motions by factors of about 2–3, though the effects appeared partially attributable to differences in shallow site response for sites on the hanging wall and footwall of the fault. Comparisons with modern ground‐motion prediction equations (GMPEs) found that the simulated ground motions were generally consistent, except within deep sedimentary basins, where simulated ground motions were greatly underpredicted. Ground‐motion variability exhibited strong lateral variations and, at some sites, exceeded the ground‐motion variability indicated by GMPEs. The effects on the ground motions of changing the values of the five kinematic rupture parameters can largely be explained by three predominant factors: distance to high‐slip subevents, dynamic stress drop, and changes in the contributions from directivity. These results emphasize the need for further characterization of the underlying distributions and covariances of the kinematic rupture parameters used in 3D ground‐motion simulations employed in probabilistic seismic‐hazard analyses.

The associations of morningness-eveningness with anger and impulsivity in the general population.

PubMed

Hwang, Jeong Yeon; Kang, Seung-Gul; Gwak, Ah Reum; Park, Juhyun; Lee, Yu Jin

2016-01-01

The aim of this study was to investigate the relationships among morningness-eveningness, impulsivity and anger in the general population. A total of 1000 community-dwelling subjects (500 males) aged 20-77 years (mean± SD age: 39.6 ± 11.6 years) completed the morningness-eveningness questionnaire (MEQ), Barratt impulsiveness scale (BIS), Spielberger State-Trait Anger Expression Inventory (STAXI) and Center for Epidemiologic Studies Depression Scale. Moderation and mediation analyses were performed to determine whether the relationship between two variables depended on the third variable, referred to as a moderator, and whether the third variable, known as a mediator, was associated with the other two variables establishing causation. The MEQ scores exhibited significant negative associations with BIS (p < 0.001) and STAXI (p < 0.001) scores, and high scores on the BIS were associated with high scores on the STAXI (p < 0.001). Impulsivity, as measured by the BIS, played a role as a moderator (p < 0.001) in the relationship between MEQ and STAXI, and anger, as measured by the STAXI, acted as moderator (p = 0.030) in the association between MEQ and BIS. However, after controlling for the interaction of the BIS and MEQ, the MEQ scores did not significantly predict STAXI scores (p = 0.070). Additionally, the effect size of the mediating effect of the BIS scores on the relationship between the MEQ and STAXI (percent mediation: 53.2%) was larger than that of the STAXI scores on the association between the MEQ and BIS (percent mediation: 31.8%). The present results demonstrate that morningness-eveningness was closely related with both impulsivity and anger in the general population. Furthermore, these findings suggest that impulsivity may exercise a great influence on the association between morningness-eveningness and anger in two ways: as a moderator by modulating this relationship based on the level of impulsivity and as a mediator by acting as an intermediary factor.

Central Asia in Context: Local Rules of the Great Game

DTIC Science & Technology

2013-05-23

warheads to Russia by 1995, and dismantled the testing facility at Semipalatinsk by 2000. Likewise, they participated with the United States in PROJECT...to take small steps to test the reaction of the new international system, in order to develop more coherent long-term strategies. As Lena Jonson...between the variables.31 If certain variables are missing, or other extraneous variables are present, the researcher can conduct other tests to consider

Are there meaningful individual differences in temporal inconsistency in self-reported personality?

PubMed

Soubelet, Andrea; Salthouse, Timothy A; Oishi, Shigehiro

2014-11-01

The current project had three goals. The first was to examine whether it is meaningful to refer to across-time variability in self-reported personality as an individual differences characteristic. The second was to investigate whether negative affect was associated with variability in self-reported personality, while controlling for mean levels, and correcting for measurement errors. The third goal was to examine whether variability in self-reported personality would be larger among young adults than among older adults, and whether the relation of variability with negative affect would be stronger at older ages than at younger ages. Two moderately large samples of participants completed the International Item Pool Personality questionnaire assessing the Big Five personality dimensions either twice or thrice, in addition to several measures of negative affect. Results were consistent with the hypothesis that within-person variability in self-reported personality is a meaningful individual difference characteristic. Some people exhibited greater across-time variability than others after removing measurement error, and people who showed temporal instability in one trait also exhibited temporal instability across the other four traits. However, temporal variability was not related to negative affect, and there was no evidence that either temporal variability or its association with negative affect varied with age.

Spatiotemporal Co-variability of Surface Climate for Renewable Energy across the Contiguous United States: Role of the North Atlantic Subtropical High

NASA Astrophysics Data System (ADS)

Doering, K.; Steinschneider, S.

2017-12-01

The variability of renewable energy supply and drivers of demand across space and time largely determines the energy balance within power systems with a high penetration of renewable technologies. This study examines the joint spatiotemporal variability of summertime climate linked to renewable energy production (precipitation, wind speeds, insolation) and energy demand (temperature) across the contiguous United States (CONUS) between 1948 and 2015. Canonical correlation analysis is used to identify the major modes of joint variability between summer wind speeds and precipitation and related patterns of insolation and temperature. Canonical variates are then related to circulation anomalies to identify common drivers of the joint modes of climate variability. Results show that the first two modes of joint variability between summer wind speeds and precipitation exhibit pan-US dipole patterns with centers of action located in the eastern and central CONUS. Temperature and insolation also exhibit related US-wide dipoles. The relationship between canonical variates and lower-tropospheric geopotential height indicates that these modes are related to variability in the North Atlantic subtropical high (NASH). This insight can inform optimal strategies for siting renewables in an interconnected electric grid, and has implications for the impacts of climate variability and change on renewable energy systems.

Systematically variable planktonic carbon metabolism along a land-to-lake gradient in a Great Lakes coastal zone.

PubMed

Weinke, Anthony D; Kendall, Scott T; Kroll, Daniel J; Strickler, Eric A; Weinert, Maggie E; Holcomb, Thomas M; Defore, Angela A; Dila, Deborah K; Snider, Michael J; Gereaux, Leon C; Biddanda, Bopaiah A

2014-11-01

During the summers of 2002-2013, we measured rates of carbon metabolism in surface waters of six sites across a land-to-lake gradient from the upstream end of drowned river-mouth Muskegon Lake (ML) (freshwater estuary) to 19 km offshore in Lake Michigan (LM) (a Great Lake). Despite considerable inter-year variability, the average rates of gross production (GP), respiration (R) and net production (NP) across ML (604 ± 58, 222 ± 22 and 381 ± 52 µg C L -1 day -1 , respectively) decreased steeply in the furthest offshore LM site (22 ± 3, 55 ± 17 and -33 ± 15 µg C L -1 day -1 , respectively). Along this land-to-lake gradient, GP decreased by 96 ± 1%, whereas R only decreased by 75 ± 9%, variably influencing the carbon balance along this coastal zone. All ML sites were consistently net autotrophic (mean GP:R = 2.7), while the furthest offshore LM site was net heterotrophic (mean GP:R = 0.4). Our study suggests that pelagic waters of this Great Lakes coastal estuary are net carbon sinks that transition into net carbon sources offshore. Reactive and dynamic estuarine coastal zones everywhere may contribute similarly to regional and global carbon cycles.

Temporal Variability and Stability in Infant-Directed Sung Speech: Evidence for Language-Specific Patterns

ERIC Educational Resources Information Center

Falk, Simone

2011-01-01

In this paper, sung speech is used as a methodological tool to explore temporal variability in the timing of word-internal consonants and vowels. It is hypothesized that temporal variability/stability becomes clearer under the varying rhythmical conditions induced by song. This is explored cross-linguistically in German--a language that exhibits a…

Thermal tolerance breadths among groundwater crustaceans living in a thermally constant environment.

PubMed

Mermillod-Blondin, F; Lefour, C; Lalouette, L; Renault, D; Malard, F; Simon, L; Douady, C J

2013-05-01

The climate variability hypothesis assumes that the thermal tolerance breadth of a species is primarily determined by temperature variations experienced in its environment. If so, aquatic invertebrates living in thermally buffered environments would be expected to exhibit narrow thermal tolerance breadths (stenothermy). We tested this prediction by studying the thermal physiology of three isopods (Asellidae, Proasellus) colonizing groundwater habitats characterized by an annual temperature amplitude of less than 1°C. The species responses to temperature variation were assessed in the laboratory using five physiological variables: survival, locomotor activity, aerobic respiration, immune defense and concentrations of total free amino acids and sugars. The three species exhibited contrasted thermal physiologies, although all variables were not equally informative. In accordance with the climate variability hypothesis, two species were extremely sensitive even to moderate changes in temperature (2°C) below and above their habitat temperature. In contrast, the third species exhibited a surprisingly high thermal tolerance breadth (11°C). Differences in response to temperature variation among Proasellus species indicated that their thermal physiology was not solely shaped by the current temperature seasonality in their natural habitats. More particularly, recent gene flow among populations living in thermally constant yet contrasted habitats might explain the occurrence of eurytherm species in thermally buffered environments.

Microstructure and Cross-Sectional Shape of Limb Bones in Great Horned Owls and Red-Tailed Hawks: How Do These Features Relate to Differences in Flight and Hunting Behavior?

PubMed Central

Marelli, Crystal A.; Simons, Erin L. R.

2014-01-01

The Red-tailed Hawk and Great Horned Owl are two species of raptor that are similar in body size, diet, and habitat. Both species use their hindlimbs during hunting, but differ in foot morphology, how they approach and immobilize prey, and the average size of prey captured. They also differ in primary flight style: the Red-tailed Hawk uses static soaring and the Great Horned Owl uses flap-gliding. The objectives of this study were to characterize the microstructure and cross-sectional shape of limb bones of these species and examine the relationship with flight and hunting behaviors. The mid-shaft of six limb bones from six individuals of each species was sampled. The degree of bone laminarity (proportion of circular primary vascular canals) and cross-sectional geometric parameters were calculated. In both species, the humerus and femur exhibited features that suggest high resistance to torsional loading, whereas the tibiotarsus and phalanges had a shape more likely to resist compression and bending in a specific plane. The femur of the Red-tailed Hawk exhibited higher laminarity and larger polar moment of area than that of the Great Horned Owl. The tibiotarsus was more elliptical than that of the Great Horned Owl. The hawk approaches prey from a more horizontal axis, takes prey of greater mass, and is more likely to pursue prey on the ground, which could potentially be causing more torsional loads on the femur and bending loads on the tibiotarsus. In addition, differences in polar moment of area of the phalanges between the species could relate to differences in foot morphology or digit length. The humerus and ulna of the flap-gliding Great Horned Owl are more elliptical than the static soaring Red-tailed Hawk, a shape that may better resist the bending loads associated with a larger amount of flapping. PMID:25162595

Microstructure and cross-sectional shape of limb bones in Great Horned Owls and Red-tailed Hawks: how do these features relate to differences in flight and hunting behavior?

PubMed

Marelli, Crystal A; Simons, Erin L R

2014-01-01

The Red-tailed Hawk and Great Horned Owl are two species of raptor that are similar in body size, diet, and habitat. Both species use their hindlimbs during hunting, but differ in foot morphology, how they approach and immobilize prey, and the average size of prey captured. They also differ in primary flight style: the Red-tailed Hawk uses static soaring and the Great Horned Owl uses flap-gliding. The objectives of this study were to characterize the microstructure and cross-sectional shape of limb bones of these species and examine the relationship with flight and hunting behaviors. The mid-shaft of six limb bones from six individuals of each species was sampled. The degree of bone laminarity (proportion of circular primary vascular canals) and cross-sectional geometric parameters were calculated. In both species, the humerus and femur exhibited features that suggest high resistance to torsional loading, whereas the tibiotarsus and phalanges had a shape more likely to resist compression and bending in a specific plane. The femur of the Red-tailed Hawk exhibited higher laminarity and larger polar moment of area than that of the Great Horned Owl. The tibiotarsus was more elliptical than that of the Great Horned Owl. The hawk approaches prey from a more horizontal axis, takes prey of greater mass, and is more likely to pursue prey on the ground, which could potentially be causing more torsional loads on the femur and bending loads on the tibiotarsus. In addition, differences in polar moment of area of the phalanges between the species could relate to differences in foot morphology or digit length. The humerus and ulna of the flap-gliding Great Horned Owl are more elliptical than the static soaring Red-tailed Hawk, a shape that may better resist the bending loads associated with a larger amount of flapping.

On the role of snow cover ablation variability and synoptic-scale atmospheric forcings at the sub-basin scale within the Great Lakes watershed

NASA Astrophysics Data System (ADS)

Suriano, Zachary J.

2018-02-01

Synoptic-scale atmospheric conditions play a critical role in determining the frequency and intensity of snow cover ablation in the mid-latitudes. Using a synoptic classification technique, distinct regional circulation patterns influencing the Great Lakes basin of North America are identified and examined in conjunction with daily snow ablation events from 1960 to 2009. This approach allows for the influence of each synoptic weather type on ablation to be examined independently and for the monthly and inter-annual frequencies of the weather types to be tracked over time. Because of the spatial heterogeneity of snow cover and the relatively large geographic extent of the Great Lakes basin, snow cover ablation events and the synoptic-scale patterns that cause them are examined for each of the Great Lakes watershed's five primary sub-basins to understand the regional complexities of snow cover ablation variability. Results indicate that while many synoptic weather patterns lead to ablation across the basins, they can be generally grouped into one of only a few primary patterns: southerly flow, high-pressure overhead, and rain-on-snow patterns. As expected, the patterns leading to ablation are not necessarily consistent between the five sub-basins due to the seasonality of snow cover and the spatial variability of temperature, moisture, wind, and incoming solar radiation associated with the particular synoptic weather types. Significant trends in the inter-annual frequency of ablation-inducing synoptic types do exist for some sub-basins, indicating a potential change in the hydrologic impact of these patterns over time.

Shoreline and coastal wetland variability along the west shore of Green Bay, Marinette and Oconto counties, Wisconsin

USGS Publications Warehouse

Shideler, Gerald L.

1994-01-01

Coastal wetland ecosystems along the Great Lakes shorelines are extremely valuable natural resources. They provide numerous environmental and recreational benefits, and they serve as critical habitats for fish and wildlife populations. In general terms, wetlands can be defined as lands transitional between terrestrial and aquatic systems; they are characterized by periodic submergence or a water table at or near the surface and a predominance of hydric soils and hydrophytes. Changes in shoreline positions over time result in concomitant changes in the amount of adjacent coastal wetlands, frequently resulting in a permanent loss of these valuable resources. In the Great Lakes region, the main natural cause of shoreline changes are lake-level fluctuations that result from two interactive factors. One factor is the glacio-isostatic rebound of the lake basins, which has been occurring since the end of the late Wisconsin glaciation to the present. This crustal rebounding has slowly uplifted previous lake outlets, warped and tilted lake basins, and changed lake levels and shoreline positions. On the basis of historic lake-level gauge records, measured modern differential vertical uplift rates range from 0.26 ft/century in the southern part of the Great Lakes drainage basin to 1.74 ft/century in the northern part of the basin (Larsen, 1989). The second factor contributing to lake-level fluctuations is climate variability, which controls the amount of regional precipitation and evaporation, storm frequency, runoff, and resulting lake levels. Climate variability can occur over a wide spectrum of time scales; it can range from seasonal variations, to long-term trends of a few years or decades in duration, to trends lasting hundred of thousands of years. Climatic variations, in conjunction with glacio-isostatic rebound, have resulted in substantial temporal variability of the Great Lakes shorelines and associated wetland tracts during post-glacial times.

First-Passage-Time Distribution for Variable-Diffusion Processes

NASA Astrophysics Data System (ADS)

Barney, Liberty; Gunaratne, Gemunu H.

2017-05-01

First-passage-time distribution, which presents the likelihood of a stock reaching a pre-specified price at a given time, is useful in establishing the value of financial instruments and in designing trading strategies. First-passage-time distribution for Wiener processes has a single peak, while that for stocks exhibits a notable second peak within a trading day. This feature has only been discussed sporadically—often dismissed as due to insufficient/incorrect data or circumvented by conversion to tick time—and to the best of our knowledge has not been explained in terms of the underlying stochastic process. It was shown previously that intra-day variations in the market can be modeled by a stochastic process containing two variable-diffusion processes (Hua et al. in, Physica A 419:221-233, 2015). We show here that the first-passage-time distribution of this two-stage variable-diffusion model does exhibit a behavior similar to the empirical observation. In addition, we find that an extended model incorporating overnight price fluctuations exhibits intra- and inter-day behavior similar to those of empirical first-passage-time distributions.

Do Clouds Save the Great Barrier Reef? Satellite Imagery Elucidates the Cloud-SST Relationship at the Local Scale

PubMed Central

Leahy, Susannah M.; Kingsford, Michael J.; Steinberg, Craig R.

2013-01-01

Evidence of global climate change and rising sea surface temperatures (SSTs) is now well documented in the scientific literature. With corals already living close to their thermal maxima, increases in SSTs are of great concern for the survival of coral reefs. Cloud feedback processes may have the potential to constrain SSTs, serving to enforce an “ocean thermostat” and promoting the survival of coral reefs. In this study, it was hypothesized that cloud cover can affect summer SSTs in the tropics. Detailed direct and lagged relationships between cloud cover and SST across the central Great Barrier Reef (GBR) shelf were investigated using data from satellite imagery and in situ temperature and light loggers during two relatively hot summers (2005 and 2006) and two relatively cool summers (2007 and 2008). Across all study summers and shelf positions, SSTs exhibited distinct drops during periods of high cloud cover, and conversely, SST increases during periods of low cloud cover, with a three-day temporal lag between a change in cloud cover and a subsequent change in SST. Cloud cover alone was responsible for up to 32.1% of the variation in SSTs three days later. The relationship was strongest in both El Niño (2005) and La Niña (2008) study summers and at the inner-shelf position in those summers. SST effects on subsequent cloud cover were weaker and more variable among study summers, with rising SSTs explaining up to 21.6% of the increase in cloud cover three days later. This work quantifies the often observed cloud cooling effect on coral reefs. It highlights the importance of incorporating local-scale processes into bleaching forecasting models, and encourages the use of remote sensing imagery to value-add to coral bleaching field studies and to more accurately predict risks to coral reefs. PMID:23894649

Connecting the Public to Natural Hazards Through a Hands-on Museum Exhibit

NASA Astrophysics Data System (ADS)

Olds, S. E.; Rowe, S. M.; Hanshumaker, W.; Farley, M.

2014-12-01

Communities along the coast of Oregon, Washington, and northern California live with the threat of potentially devastating subduction zone earthquakes and subsequent tsunami that could happen at any time. Both residents and visitors to the coast need to be aware of the potential impacts such hazards can have on their lives as well as what to do during an earthquake and before a tsunami hits. To raise awareness of both natural hazards and the technologies used to monitor them, UNAVCO designed and installed a museum exhibit on display at Oregon State University's Hatfield Marine Science Center (HMSC) Visitor Center in Newport, Oregon. The objectives for the exhibit are to increase familiarization with the natural hazards of earthquakes and tsunamis in the Cascadia region, to explain the connection between the crust's movement and compression over time with the potential strength of a subduction-zone earthquake, and to inform visitors about high-precision, high-rate GPS technology. The exhibit includes multiple hands-on models and an authentic GPS monitoring station. Additionally, panels explain the science behind the models, potential impacts of a great earthquake to society, and actions visitors can take to practice earthquake safety through the Great ShakeOut earthquake drill. Over the past year that the exhibit has been open to the public, it has been visited by over 100,000 people including students, family and senior groups, and the general public. Anecdotal evidence indicates that two components of the exhibit create the most visitor impact providing visitors with 'ah ha moments': a real-scale tape measure showing the approximate 12 foot distance the coast has compressed over the past 300+ years, and a flexible map illustrating that the coastal areas are compressing the most compared to areas further inland. Through HMSC's NSF-funded Cyberlab automated visitor data collection system, we have been able to document and analyze a variety of visitor characteristics including number of people visiting the various elements of the exhibit, time on exhibit elements, order of visitation, grouping characteristics, and basic use of the exhibit as a learning tool by groups. During this session we will share the successes and challenges of the exhibit and next steps to further raise awareness about natural hazards of the region.

Taxonomy

Treesearch

Kimball T. Harper; John D. Shane; John R. Jones

1985-01-01

Quaking aspen, or trembling aspen (Populus tremuloides), was named and described by Michaux in 1803. It exhibits marked phenotypic variability throughout its transcontinental range. Numerous authors, especially the early ones, tried to give order to the variability by subdividing it taxonomically. Quahng aspen has been subdivided by various...

A spatial classification and database for management, research, and policy making: The Great Lakes aquatic habitat framework

USGS Publications Warehouse

Wang, Lizhu; Riseng, Catherine M.; Mason, Lacey; Werhrly, Kevin; Rutherford, Edward; McKenna, James E.; Castiglione, Chris; Johnson, Lucinda B.; Infante, Dana M.; Sowa, Scott P.; Robertson, Mike; Schaeffer, Jeff; Khoury, Mary; Gaiot, John; Hollenhurst, Tom; Brooks, Colin N.; Coscarelli, Mark

2015-01-01

Managing the world's largest and most complex freshwater ecosystem, the Laurentian Great Lakes, requires a spatially hierarchical basin-wide database of ecological and socioeconomic information that is comparable across the region. To meet such a need, we developed a spatial classification framework and database — Great Lakes Aquatic Habitat Framework (GLAHF). GLAHF consists of catchments, coastal terrestrial, coastal margin, nearshore, and offshore zones that encompass the entire Great Lakes Basin. The catchments captured in the database as river pour points or coastline segments are attributed with data known to influence physicochemical and biological characteristics of the lakes from the catchments. The coastal terrestrial zone consists of 30-m grid cells attributed with data from the terrestrial region that has direct connection with the lakes. The coastal margin and nearshore zones consist of 30-m grid cells attributed with data describing the coastline conditions, coastal human disturbances, and moderately to highly variable physicochemical and biological characteristics. The offshore zone consists of 1.8-km grid cells attributed with data that are spatially less variable compared with the other aquatic zones. These spatial classification zones and their associated data are nested within lake sub-basins and political boundaries and allow the synthesis of information from grid cells to classification zones, within and among political boundaries, lake sub-basins, Great Lakes, or within the entire Great Lakes Basin. This spatially structured database could help the development of basin-wide management plans, prioritize locations for funding and specific management actions, track protection and restoration progress, and conduct research for science-based decision making.

Evaluation of Sugar Maple Dieback in the Upper Great Lakes Region and Development of a Forest Health Youth Education Program

ERIC Educational Resources Information Center

Bal, Tara L.

2013-01-01

Sugar Maple, "Acer saccharum" Marsh., is one of the most valuable trees in the northern hardwood forests. Severe dieback was recently reported by area foresters in the western Upper Great Lakes Region. Sugar Maple has had a history of dieback over the last 100 years throughout its range and different variables have been identified as…

Actor-Partner Interdependence Model Analysis of Sexual Communication and Relationship/Family Planning Factors Among Immigrant Latino Couples in the United States.

PubMed

Matsuda, Yui

2017-05-01

The Latino population in the United States is quickly growing, and its unintended pregnancy rate is increasing. To decrease unintended pregnancies, couples must mutually agree on family planning. Communication between partners is one key factor identified in successful family planning for couples. Therefore, the purpose of this study was to examine sexual communication and its associations with sexual relationship power, general communication, and views on family planning. The Actor-Partner Interdependence Model was used to analyze dyadic influences of the chosen variables. Forty immigrant Latino couples were recruited from prenatal care clinics. The study results were grouped according to the three types of power structures: exhibition of men's traditional machismo values, exhibition of women's increased power in their relationships, and exhibition of men's and women's own empowerment with sexual communication. There was a negative association between men's views on family planning and women's sexual communication (exhibition of machismo values); a negative association between women's sexual relationship power and their partners' sexual communication (exhibition of women's increased power); and positive associations between men's and women's general communication and sexual communication (exhibition of men's and women's own empowerment). Dyadic influences of sexual communication and associated variables need to be incorporated into interventions to facilitate family planning for couples.

Its All about Choice

ERIC Educational Resources Information Center

Bowen, G. Michael; Arsenault, Nicole

2008-01-01

Because of the variability exhibited by individual animals' responses to their environment, studying animal behavior can be a wonderful way to engage students in self-directed, open-inquiry investigations. Individual animals react in ways that are a combination of instinct and learned behavior, but collectively they exhibit broader tendencies that…

Spatial variation in population growth rate and community structure affects local and regional dynamics.

PubMed

Trzcinski, M Kurtis; Walde, Sandra J; Taylor, Philip D

2008-11-01

1. Theory predicting that populations with high maximum rates of increase (r(max)) will be less stable, and that metapopulations with high average r(max) will be less synchronous, was tested using a small protist, Bodo, that inhabits pitcher plant leaves (Sarracenia purpurea L.). The effects of predators and resources on these relationships were also determined. 2. Abundance data collected for a total of 60 populations of Bodo, over a period of 3 months, at six sites in three bogs in eastern Canada, were used to test these predictions. Mosquitoes were manipulated in half the leaves partway through the season to increase the range of predation rates. 3. Dynamics differed greatly among leaves and sites, but most populations exhibited one or more episodes of rapid increase followed by a population crash. Estimates of r(max) obtained using a linear mixed-effects model, ranged from 1 x 5 to 2 x 7 per day. Resource levels (captured insect) and midge abundances affected r(max). 4. Higher r(max) was associated with greater temporal variability and lower synchrony as predicted. However, in contrast to expectations, populations with higher r(max) also had lower mean abundance and were more suppressed by predators. 5. This study demonstrates that the link between r(max) and temporal variability is key to understanding the dynamics of populations that spend little time near equilibrium, and to predicting and interpreting the effects of community structure on the dynamics of such populations.

A model for evaluating the social performance of construction waste management

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

Yuan Hongping, E-mail: hpyuan2005@gmail.com

Highlights: Black-Right-Pointing-Pointer Scant attention is paid to social performance of construction waste management (CWM). Black-Right-Pointing-Pointer We develop a model for assessing the social performance of CWM. Black-Right-Pointing-Pointer With the model, the social performance of CWM can be quantitatively simulated. - Abstract: It has been determined by existing literature that a lot of research efforts have been made to the economic performance of construction waste management (CWM), but less attention is paid to investigation of the social performance of CWM. This study therefore attempts to develop a model for quantitatively evaluating the social performance of CWM by using a system dynamicsmore » (SD) approach. Firstly, major variables affecting the social performance of CWM are identified and a holistic system for assessing the social performance of CWM is formulated in line with feedback relationships underlying these variables. The developed system is then converted into a SD model through the software iThink. An empirical case study is finally conducted to demonstrate application of the model. Results of model validation indicate that the model is robust and reasonable to reflect the situation of the real system under study. Findings of the case study offer helpful insights into effectively promoting the social performance of CWM of the project investigated. Furthermore, the model exhibits great potential to function as an experimental platform for dynamically evaluating effects of management measures on improving the social performance of CWM of construction projects.« less

Performance evaluation of nonhomogeneous hospitals: the case of Hong Kong hospitals.

PubMed

Li, Yongjun; Lei, Xiyang; Morton, Alec

2018-02-14

Throughout the world, hospitals are under increasing pressure to become more efficient. Efficiency analysis tools can play a role in giving policymakers insight into which units are less efficient and why. Many researchers have studied efficiencies of hospitals using data envelopment analysis (DEA) as an efficiency analysis tool. However, in the existing literature on DEA-based performance evaluation, a standard assumption of the constant returns to scale (CRS) or the variable returns to scale (VRS) DEA models is that decision-making units (DMUs) use a similar mix of inputs to produce a similar set of outputs. In fact, hospitals with different primary goals supply different services and provide different outputs. That is, hospitals are nonhomogeneous and the standard assumption of the DEA model is not applicable to the performance evaluation of nonhomogeneous hospitals. This paper considers the nonhomogeneity among hospitals in the performance evaluation and takes hospitals in Hong Kong as a case study. An extension of Cook et al. (2013) [1] based on the VRS assumption is developed to evaluated nonhomogeneous hospitals' efficiencies since inputs of hospitals vary greatly. Following the philosophy of Cook et al. (2013) [1], hospitals are divided into homogeneous groups and the product process of each hospital is divided into subunits. The performance of hospitals is measured on the basis of subunits. The proposed approach can be applied to measure the performance of other nonhomogeneous entities that exhibit variable return to scale.

Interindividual variability of soil arsenic metabolism by human gut microbiota using SHIME model.

PubMed

Yin, Naiyi; Du, Huili; Wang, Pengfei; Cai, Xiaolin; Chen, Peng; Sun, Guoxin; Cui, Yanshan

2017-10-01

Arsenic (As) metabolism by human gut microbiota has been evidenced with in vitro experiments from contaminated soils. In this study, the variability in the metabolic potency toward As-contaminated soils and gut microbial diversity were investigated between healthy individuals (Adult versus Child). Arsenic bioaccessibility in the colon phase increased by 1.4-6.8 and 1.2-8.7 folds for adult and child, respectively. We found a high degree of As methylation for the colon digests of the adult (mean 2 μg methylarsenicals/hr/g biomass), 3-folds higher than that of the child. Besides, arsenite [As(III)] concentration (1.5-391.3 μg/L) for the child was 2-18 times for the adult. 16S rRNA gene sequencing revealed that human gut microbiota from 20 various genera potentially had resistance genes to reduce and methylate As under conservative statistics. Our results indicated that As metabolism by gut microbiota from adult and child was significantly different. The adult gut microbiota had a great ability of As methylation; the child gut microbiota exhibited high As(III) level, which could encounter high health risk. The identity and activity of arsenic-metabolizing bacteria isolated from human gut and its homologous role in As metabolism need be further explored. This study provides a better understanding of health risk assessment to adults and children upon soil As exposures. Copyright © 2017 Elsevier Ltd. All rights reserved.

Contactless Determination of Electrical Conductivity of One-Dimensional Nanomaterials by Solution-Based Electro-orientation Spectroscopy

DOE PAGES

Akin, Cevat; Yi, Jingang; Feldman, Leonard C.; ...

2015-05-05

For nanowires of the same composition, and even fabricated within the same batch, often exhibit electrical conductivities that can vary by orders of magnitude. Unfortunately, existing electrical characterization methods are time-consuming, making the statistical survey of highly variable samples essentially impractical. Here, we demonstrate a contactless, solution-based method to efficiently measure the electrical conductivity of 1D nanomaterials based on their transient alignment behavior in ac electric fields of different frequencies. In comparison with direct transport measurements by probe-based scanning tunneling microscopy shows that electro-orientation spectroscopy can quantitatively measure nanowire conductivity over a 5-order-of-magnitude range, 10–5–1 Ω–1 m–1 (corresponding to resistivitiesmore » in the range 102–107 Ω·cm). With this method, we statistically characterize the conductivity of a variety of nanowires and find significant variability in silicon nanowires grown by metal-assisted chemical etching from the same wafer. We also find that the active carrier concentration of n-type silicon nanowires is greatly reduced by surface traps and that surface passivation increases the effective conductivity by an order of magnitude. Moreover, this simple method makes electrical characterization of insulating and semiconducting 1D nanomaterials far more efficient and accessible to more researchers than current approaches. Electro-orientation spectroscopy also has the potential to be integrated with other solution-based methods for the high-throughput sorting and manipulation of 1D nanomaterials for postgrowth device assembly.« less

The Influence of Infant Feeding Practices on Infant Mortality in Southern Africa.

PubMed

Motsa, Lungile F; Ibisomi, Latifat; Odimegwu, Clifford

2016-10-01

Objective To examine the adjusted and unadjusted effects of infant feeding practices on infant mortality in Southern Africa. Methods A merged dataset from the most recent Demographic and Health Surveys for Lesotho, Swaziland, Zambia and Zimbabwe was analysed using the Cox Proportional Hazard Model. A total number of 13,218 infants born in 5 years preceding all the surveys with information on infant feeding practices constituted the study population. Infant mortality was the outcome variable and infant feeding practices categorised into; no breastfeeding, partial breastfeeding and exclusive breastfeeding were the main explanatory variables. Maternal demographic and socio-economic characteristics and infants' bio-demographic characteristics were also studied. Results Although, exclusive breastfeeding was quite low (12 %), exclusively breastfed infants exhibited a 97 % lower risk of dying during infancy compared to infants not breastfed in the region. Variations existed by country in the levels and patterns of both infant mortality and infant feeding practices. Mother's country, highest level of education and marital status; child's sex, birth weight and preceding birth interval were the significant predictors of infant mortality in Southern Africa. Conclusions Any form of breastfeeding whether exclusive or partial breastfeeding greatly reduces the risk of infant mortality with the greatest mortality reduction effect observed among exclusively breastfed infants in Southern Africa. To reduce the upsurge of infant mortality, there is the need to step up the effectiveness of child nutrition programmes that promote breastfeeding and put emphasis on exclusive breastfeeding of infants in the region.

Coral Luminescence Identifies the Pacific Decadal Oscillation as a Primary Driver of River Runoff Variability Impacting the Southern Great Barrier Reef

PubMed Central

Rodriguez-Ramirez, Alberto; Grove, Craig A.; Zinke, Jens; Pandolfi, John M.; Zhao, Jian-xin

2014-01-01

The Pacific Decadal Oscillation (PDO) is a large-scale climatic phenomenon modulating ocean-atmosphere variability on decadal time scales. While precipitation and river flow variability in the Great Barrier Reef (GBR) catchments are sensitive to PDO phases, the extent to which the PDO influences coral reefs is poorly understood. Here, six Porites coral cores were used to produce a composite record of coral luminescence variability (runoff proxy) and identify drivers of terrestrial influence on the Keppel reefs, southern GBR. We found that coral skeletal luminescence effectively captured seasonal, inter-annual and decadal variability of river discharge and rainfall from the Fitzroy River catchment. Most importantly, although the influence of El Niño-Southern Oscillation (ENSO) events was evident in the luminescence records, the variability in the coral luminescence composite record was significantly explained by the PDO. Negative luminescence anomalies (reduced runoff) were associated with El Niño years during positive PDO phases while positive luminescence anomalies (increased runoff) coincided with strong/moderate La Niña years during negative PDO phases. This study provides clear evidence that not only ENSO but also the PDO have significantly affected runoff regimes at the Keppel reefs for at least a century, and suggests that upcoming hydrological disturbances and ecological responses in the southern GBR region will be mediated by the future evolution of these sources of climate variability. PMID:24416214

Coral luminescence identifies the Pacific Decadal Oscillation as a primary driver of river runoff variability impacting the southern Great Barrier Reef.

PubMed

Rodriguez-Ramirez, Alberto; Grove, Craig A; Zinke, Jens; Pandolfi, John M; Zhao, Jian-xin

2014-01-01

The Pacific Decadal Oscillation (PDO) is a large-scale climatic phenomenon modulating ocean-atmosphere variability on decadal time scales. While precipitation and river flow variability in the Great Barrier Reef (GBR) catchments are sensitive to PDO phases, the extent to which the PDO influences coral reefs is poorly understood. Here, six Porites coral cores were used to produce a composite record of coral luminescence variability (runoff proxy) and identify drivers of terrestrial influence on the Keppel reefs, southern GBR. We found that coral skeletal luminescence effectively captured seasonal, inter-annual and decadal variability of river discharge and rainfall from the Fitzroy River catchment. Most importantly, although the influence of El Niño-Southern Oscillation (ENSO) events was evident in the luminescence records, the variability in the coral luminescence composite record was significantly explained by the PDO. Negative luminescence anomalies (reduced runoff) were associated with El Niño years during positive PDO phases while positive luminescence anomalies (increased runoff) coincided with strong/moderate La Niña years during negative PDO phases. This study provides clear evidence that not only ENSO but also the PDO have significantly affected runoff regimes at the Keppel reefs for at least a century, and suggests that upcoming hydrological disturbances and ecological responses in the southern GBR region will be mediated by the future evolution of these sources of climate variability.

Model-assisted forest yield estimation with light detection and ranging

Treesearch

Jacob L. Strunk; Stephen E. Reutebuch; Hans-Erik Andersen; Peter J. Gould; Robert J. McGaughey

2012-01-01

Previous studies have demonstrated that light detection and ranging (LiDAR)-derived variables can be used to model forest yield variables, such as biomass, volume, and number of stems. However, the next step is underrepresented in the literature: estimation of forest yield with appropriate confidence intervals. It is of great importance that the procedures required for...

Monthly and seasonal variability of the land-atmosphere system

Treesearch

Yong-Qiang Liu

2003-01-01

The land surface and the atmosphere can interact with each other through exchanges of energy, water, and momentum. With the capacity of long memory, land surface processes can contribute to long-term variability of atmospheric processes. Great efforts have been made in the past three decades to study land-atmosphere interactions and their importance to long-term...

Dimensional analysis of flame angles versus wind speed

Treesearch

Robert E. Martin; Mark A. Finney; Domingo M. Molina; David B. Sapsis; Scott L. Stephens; Joe H. Scott; David R. Weise

1991-01-01

Dimensional analysis has potential to help explain and predict physical phenomena, but has been used very little in studies of wildland fire behavior. By combining variables into dimensionless groups, the number of variables to be handled and the experiments to be run is greatly reduced. A low velocity wind tunnel was constructed, and methyl, ethyl, and isopropyl...

Tuning group-velocity dispersion by optical force.

PubMed

Jiang, Wei C; Lin, Qiang

2013-07-15

We propose an optomechanical approach for dispersion dynamic tuning and microengineering by taking advantage of the optical force in nano-optomechanical structures. Simulations of a suspended coupled silicon waveguide show that the zero-dispersion wavelength can be tuned by 40 nm by an optical pump power of 3 mW. Our approach exhibits great potential for broad applications in dispersion-sensitive processes, which not only offers a new root toward versatile tunable nonlinear photonics but may also open up a great avenue toward a new regime of nonlinear dynamics coupling between nonlinear optical and optomechanical effects.

Comparative and Familial Analysis of Handedness in Great Apes

PubMed Central

Hopkins, William D.

2007-01-01

Historically, population-level handedness has been considered a hallmark of human evolution. Whether nonhuman primates exhibit population-level handedness remains a topic of considerable debate. This paper summarizes published data on handedness in great apes. Comparative analysis indicated that chimpanzees and bonobos show population-level right handedness, whereas gorillas and orangutans do not. All ape species showed evidence of population-level handedness when considering specific tasks. Familial analyses in chimpanzees indicated that offspring and maternal (but not paternal) handedness was significantly positively correlated, but this finding was contingent upon the classification criteria used to evaluate hand preference. Overall, the proportion of right handedness is lower in great apes compared with humans, and various methodological and theoretical explanations for this discrepancy are discussed. PMID:16822166

Oxidation resistant, thoria-dispersed nickel-chromium-aluminum alloy

NASA Technical Reports Server (NTRS)

Baranow, S.; Klingler, L. J.

1973-01-01

Modified thoria-dispersed nickel-chromium alloy has been developed that exhibits greatly improved resistance to high-temperature oxidation. Additions of aluminum have been made to change nature of protective oxide scale entirely and to essentially inhibit oxidation at temperatures up to 1260 C.

Use of benzo anologs to enhance antimycotic activity of kresoxim methyl for control of aflatoxigenic fungal pathogens

USDA-ARS?s Scientific Manuscript database

Potentiation of the conventional fungicide, strobilurin, was achieved by octylgallate-mediated chemosensitization. Octylgallate exhibited considerably higher antifungal activity compared to veratraldehyde. Octylgallate in concert with the fungicide, strobilurin (kresoxim methyl), greatly enhanced se...

Nine and Ten chemical haloacetic acid mixtures exhibit concentration-dependent departure from dose additivity

EPA Science Inventory

Disinfection of water greatly decreases waterborne disease. Disinfection byproducts (DBPs), including haloacetic acids (HAAs), are formed when oxidizing disinfectants react with inorganic and organic matter in water. Water providers routinely assay for 9 HAAs in finished drinking...

A probabilistic fatigue analysis of multiple site damage

NASA Technical Reports Server (NTRS)

Rohrbaugh, S. M.; Ruff, D.; Hillberry, B. M.; Mccabe, G.; Grandt, A. F., Jr.

1994-01-01

The variability in initial crack size and fatigue crack growth is incorporated in a probabilistic model that is used to predict the fatigue lives for unstiffened aluminum alloy panels containing multiple site damage (MSD). The uncertainty of the damage in the MSD panel is represented by a distribution of fatigue crack lengths that are analytically derived from equivalent initial flaw sizes. The variability in fatigue crack growth rate is characterized by stochastic descriptions of crack growth parameters for a modified Paris crack growth law. A Monte-Carlo simulation explicitly describes the MSD panel by randomly selecting values from the stochastic variables and then grows the MSD cracks with a deterministic fatigue model until the panel fails. Different simulations investigate the influences of the fatigue variability on the distributions of remaining fatigue lives. Six cases that consider fixed and variable conditions of initial crack size and fatigue crack growth rate are examined. The crack size distribution exhibited a dominant effect on the remaining fatigue life distribution, and the variable crack growth rate exhibited a lesser effect on the distribution. In addition, the probabilistic model predicted that only a small percentage of the life remains after a lead crack develops in the MSD panel.

Linear solvation energy relationships: "rule of thumb" for estimation of variable values

USGS Publications Warehouse

Hickey, James P.; Passino-Reader, Dora R.

1991-01-01

For the linear solvation energy relationship (LSER), values are listed for each of the variables (Vi/100, π*, &betam, αm) for fundamental organic structures and functional groups. We give the guidelines to estimate LSER variable values quickly for a vast array of possible organic compounds such as those found in the environment. The difficulty in generating these variables has greatly discouraged the application of this quantitative structure-activity relationship (QSAR) method. This paper present the first compilation of molecular functional group values together with a utilitarian set of the LSER variable estimation rules. The availability of these variable values and rules should facilitate widespread application of LSER for hazard evaluation of environmental contaminants.

Symptoms of Post-Traumatic Stress Disorder Among Young Children 2 Years After the Great East Japan Earthquake.

PubMed

Fujiwara, Takeo; Yagi, Junko; Homma, Hiroaki; Mashiko, Hirofumi; Nagao, Keizo; Okuyama, Makiko

2017-04-01

The aim of this study was to investigate the prevalence of post-traumatic stress disorder (PTSD) and its association with each traumatic experience among 5- to 8-year-old children 2 years after the Great East Japan Earthquake. Children ages 5-8 years who were in selected preschool classes on March 11, 2011, in 3 prefectures affected by the earthquake and 1 prefecture that was unaffected, participated in the study (N=280). PTSD symptoms were assessed through questionnaires completed by caregivers and interviews by psychiatrists or psychologists conducted between September 2012 and May 2013 (ie, 1.5-2 years after the earthquake). Among children who experienced the earthquake, 33.8% exhibited PTSD symptoms. Of the different traumatic experiences, experiencing the earthquake and the loss of distant relatives or friends were independently associated with PTSD symptoms; prevalence ratios: 6.88 (95% confidence interval [CI]: 2.06-23.0) and 2.48 (95% CI: 1.21-5.08), respectively. Approximately 1 in 3 young children in the affected communities exhibited PTSD symptoms, even 2 years after the Great East Japan Earthquake. These data may be useful for preventing PTSD symptoms after natural disasters and suggest the importance of providing appropriate mental health services for children. (Disaster Med Public Health Preparedness. 2017;11:207-215).

Differential Impacts of Climate Change on Crops and Agricultural Regions in India

NASA Astrophysics Data System (ADS)

Sharma, A. N.

2015-12-01

As India's farmers and policymakers consider potential adaptation strategies to climate change, some questions loom large: - Which climate variables best explain the variability of crop yields? - How does the vulnerability of crop yields to climate vary regionally? - How are these risks likely to change in the future? While process-based crop modelling has started to answer many of these questions, we believe statistical approaches can complement these in improving our understanding of climate vulnerabilities and appropriate responses. We use yield data collected over three decades for more than ten food crops grown in India along with a variety of statistical approaches to answer the above questions. The ability of climate variables to explain yield variation varies greatly by crop and season, which is expected. Equally important, the ability of models to predict crop yields as well as their coefficients varies greatly by district even for districts which are relatively close to each other and similar in their agricultural practices. We believe these results encourage caution and nuance when making projections about climate impacts on crop yields in the future. Most studies about climate impacts on crop yields focus on a handful of major food crops. By extending our analysis to all the crops with long-term district level data in India as well as two growing seasons we gain a more comprehensive picture. Our results indicate that there is a great deal of variability even at relatively small scales, and that this must be taken into account if projections are to be made useful to policymakers.

Aquatic insect ecophysiological traits reveal phylogenetically based differences in dissolved cadmium susceptibility

USGS Publications Warehouse

Buchwalter, D.B.; Cain, D.J.; Martin, C.A.; Xie, Lingtian; Luoma, S.N.; Garland, T.

2008-01-01

We used a phylogenetically based comparative approach to evaluate the potential for physiological studies to reveal patterns of diversity in traits related to susceptibility to an environmental stressor, the trace metal cadmium (Cd). Physiological traits related to Cd bioaccumulation, compartmentalization, and ultimately susceptibility were measured in 21 aquatic insect species representing the orders Ephemeroptera, Plecoptera, and Trichoptera. We mapped these experimentally derived physiological traits onto a phylogeny and quantified the tendency for related species to be similar (phylogenetic signal). All traits related to Cd bioaccumulation and susceptibility exhibited statistically significant phylogenetic signal, although the signal strength varied among traits. Conventional and phylogenetically based regression models were compared, revealing great variability within orders but consistent, strong differences among insect families. Uptake and elimination rate constants were positively correlated among species, but only when effects of body size and phylogeny were incorporated in the analysis. Together, uptake and elimination rates predicted dramatic Cd bioaccumulation differences among species that agreed with field-based measurements. We discovered a potential tradeoff between the ability to eliminate Cd and the ability to detoxify it across species, particularly mayflies. The best-fit regression models were driven by phylogenetic parameters (especially differences among families) rather than functional traits, suggesting that it may eventually be possible to predict a taxon's physiological performance based on its phylogenetic position, provided adequate physiological information is available for close relatives. There appears to be great potential for evolutionary physiological approaches to augment our understanding of insect responses to environmental stressors in nature. ?? 2008 by The National Academy of Sciences of the USA.

Stream Invertebrate Communities, Water Quality, and Land-Use Patterns in an Agricultural Drainage Basin of Northeastern Nebraska, USA

NASA Astrophysics Data System (ADS)

Whiles, Matt R.; Brock, Brent L.; Franzen, Annette C.; Dinsmore, Steven C., II

2000-11-01

We used invertebrate bioassessment, habitat analysis, geographic information system analysis of land use, and water chemistry monitoring to evaluate tributaries of a degraded northeast Nebraska, USA, reservoir. Bimonthly invertebrate collections and monthly water chemistry samples were collected for two years on six stream reaches to identify sources contributing to reservoir degradation and test suitability of standard rapid bioassessment methods in this region. A composite biotic index composed of seven commonly used metrics was effective for distinguishing between differentially impacted sites and responded to a variety of disturbances. Individual metrics varied greatly in precision and ability to discriminate between relatively impacted and unimpacted stream reaches. A modified Hilsenhoff index showed the highest precision (reference site CV = 0.08) but was least effective at discriminating among sites. Percent dominance and the EPT (number of Ephemeroptera, Plecoptera, and Trichoptera taxa) metrics were most effective at discriminating between sites and exhibited intermediate precision. A trend of higher biotic integrity during summer was evident, indicating seasonal corrections should differ from other regions. Poor correlations were evident between water chemistry variables and bioassessment results. However, land-use factors, particularly within 18-m riparian zones, were correlated with bioassessment scores. For example, there was a strong negative correlation between percentage of rangeland in 18-m riparian zones and percentage of dominance in streams (r 2 = 0.90, P < 0.01). Results demonstrate that standard rapid bioassessment methods, with some modifications, are effective for use in this agricultural region of the Great Plains and that riparian land use may be the best predictor of stream biotic integrity.

Laboratory blood analysis in Strigiformes-Part I: hematologic reference intervals and agreement between manual blood cell counting techniques.

PubMed

Ammersbach, Mélanie; Beaufrère, Hugues; Gionet Rollick, Annick; Tully, Thomas

2015-03-01

While hematologic reference intervals (RI) are available for multiple raptorial species of the order Accipitriformes and Falconiformes, there is a lack of valuable hematologic information in Strigiformes that can be used for diagnostic and health monitoring purposes. The objective was to report RI in Strigiformes for hematologic variables and to assess agreement between manual cell counting techniques. A multi-center prospective study was designed to assess hematologic RI and blood cell morphology in owl species. Samples were collected from individuals representing 13 Strigiformes species, including Great Horned Owl, Snowy Owl, Eurasian Eagle Owl, Barred Owl, Great Gray Owl, Ural Owl, Northern Saw-Whet Owls, Northern Hawk Owl, Spectacled Owl, Barn Owl, Eastern Screech Owl, Long-Eared Owl, and Short-Eared Owl. Red blood cell count was determined manually using a hemocytometer. White blood cell count was determined using 3 manual counting techniques: (1) phloxine B technique, (2) Natt and Herrick technique, and (3) estimation from the smear. Differential counts and blood cell morphology were determined on smears. Reference intervals were determined and agreement between methods was calculated. Important species-specific differences were observed in blood cell counts and granulocyte morphology. Differences in WBC count between species did not appear to be predictable based on phylogenetic relationships. Overall, most boreal owl species exhibited a lower WBC count than other species. Important disagreements were found between different manual WBC counting techniques. Disagreements observed between manual counting techniques suggest that technique-specific RI should be used in Strigiformes. © 2015 American Society for Veterinary Clinical Pathology.

Investigating the chemical mist deposition technique for poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) on textured crystalline-silicon for organic/crystalline-silicon heterojunction solar cells

NASA Astrophysics Data System (ADS)

Hossain, Jaker; Ohki, Tatsuya; Ichikawa, Koki; Fujiyama, Kazuhiko; Ueno, Keiji; Fujii, Yasuhiko; Hanajiri, Tatsuro; Shirai, Hajime

2016-03-01

Chemical mist deposition (CMD) of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) was investigated in terms of cavitation frequency f, solvent, flow rate of nitrogen, substrate temperature Ts, and substrate dc bias Vs as variables for efficient PEDOT:PSS/crystalline silicon (c-Si) heterojunction solar cells. The high-speed-camera and differential mobility analysis characterizations revealed that the average size and flux of PEDOT:PSS mist depend on f, type of solvent, and Vs. Film deposition occurred when positive Vs was applied to the c-Si substrate at Ts of 30-40 °C, whereas no deposition of films occurred with negative Vs, implying that the film is deposited mainly from negatively charged mist. The uniform deposition of PEDOT:PSS films occurred on textured c-Si(100) substrates by adjusting Ts and Vs. The adhesion of CMD PEDOT:PSS film to c-Si was greatly enhanced by applying substrate dc bias Vs compared with that of spin-coated film. The CMD PEDOT:PSS/c-Si heterojunction solar cell devices on textured c-Si(100) in 2 × 2 cm2 exhibited a power conversion efficiency η of 11.0% with better uniformity of the solar cell parameters. Furthermore, η was increased to 12.5% by adding an AR coating layer of molybdenum oxide MoOx formed by CMD. These findings suggest that CMD with negatively charged mist has great potential for the uniform deposition of organic and inorganic materials on textured c-Si substrates by suitably adjusting Ts and Vs.

Genetic variability and phenotypic plasticity of metric thoracic traits in an invasive drosophilid in America.

PubMed

Bitner-Mathé, Blanche Christine; David, Jean Robert

2015-08-01

Thermal phenotypic plasticity of 5 metric thoracic traits (3 related to size and 2 to pigmentation) was investigated in Zaprionus indianus with an isofemale line design. Three of these traits are investigated for the first time in a drosophilid, i.e. thorax width and width of pigmented longitudinal white and black stripes. The reaction norms of white and black stripes were completely different: white stripes were insensitive to growth temperature while the black stripes exhibited a strong linear decrease with increasing temperatures. Thorax width exhibited a concave reaction norm, analogous but not identical to those of wing length and thorax length: the temperatures of maximum value were different, the highest being for thorax width. All traits exhibited a significant heritable variability and a low evolvability. Sexual dimorphism was very variable among traits, being nil for white stripes and thorax width, and around 1.13 for black stripes. The ratio thorax length to thorax width (an elongation index) was always >1, showing that males have a more rounded thorax at all temperatures. Black stripes revealed a significant increase of sexual dimorphism with increasing temperature. Shape indices, i.e. ratios between size traits all exhibited a linear decrease with temperature, the least sensitive being the elongation index. All these results illustrate the complexity of developmental processes but also the analytical strength of biometrical plasticity studies in an eco-devo perspective.

Variable Selection for Support Vector Machines in Moderately High Dimensions

PubMed Central

Zhang, Xiang; Wu, Yichao; Wang, Lan; Li, Runze

2015-01-01

Summary The support vector machine (SVM) is a powerful binary classification tool with high accuracy and great flexibility. It has achieved great success, but its performance can be seriously impaired if many redundant covariates are included. Some efforts have been devoted to studying variable selection for SVMs, but asymptotic properties, such as variable selection consistency, are largely unknown when the number of predictors diverges to infinity. In this work, we establish a unified theory for a general class of nonconvex penalized SVMs. We first prove that in ultra-high dimensions, there exists one local minimizer to the objective function of nonconvex penalized SVMs possessing the desired oracle property. We further address the problem of nonunique local minimizers by showing that the local linear approximation algorithm is guaranteed to converge to the oracle estimator even in the ultra-high dimensional setting if an appropriate initial estimator is available. This condition on initial estimator is verified to be automatically valid as long as the dimensions are moderately high. Numerical examples provide supportive evidence. PMID:26778916

The MASIV Survey - IV. Relationship between intra-day scintillation and intrinsic variability of radio AGNs

NASA Astrophysics Data System (ADS)

Koay, J. Y.; Macquart, J.-P.; Jauncey, D. L.; Pursimo, T.; Giroletti, M.; Bignall, H. E.; Lovell, J. E. J.; Rickett, B. J.; Kedziora-Chudczer, L.; Ojha, R.; Reynolds, C.

2018-03-01

We investigate the relationship between 5 GHz interstellar scintillation (ISS) and 15 GHz intrinsic variability of compact, radio-selected active galactic nuclei (AGNs) drawn from the Microarcsecond Scintillation-Induced Variability (MASIV) Survey and the Owens Valley Radio Observatory blazar monitoring program. We discover that the strongest scintillators at 5 GHz (modulation index, m5 ≥ 0.02) all exhibit strong 15 GHz intrinsic variability (m15 ≥ 0.1). This relationship can be attributed mainly to the mutual dependence of intrinsic variability and ISS amplitudes on radio core compactness at ˜ 100 μas scales, and to a lesser extent, on their mutual dependences on source flux density, arcsec-scale core dominance and redshift. However, not all sources displaying strong intrinsic variations show high amplitude scintillation, since ISS is also strongly dependent on Galactic line-of-sight scattering properties. This observed relationship between intrinsic variability and ISS highlights the importance of optimizing the observing frequency, cadence, timespan and sky coverage of future radio variability surveys, such that these two effects can be better distinguished to study the underlying physics. For the full MASIV sample, we find that Fermi-detected gamma-ray loud sources exhibit significantly higher 5 GHz ISS amplitudes than gamma-ray quiet sources. This relationship is weaker than the known correlation between gamma-ray loudness and the 15 GHz variability amplitudes, most likely due to jet opacity effects.

Toward Understanding Business Student Professional Development Engagement

ERIC Educational Resources Information Center

Blau, Gary; Blessley, Misty; Kunkle, Matthew; Schirmer, Michael; Regan, Laureen

2017-01-01

Professional development engagement (PDE) is defined as the level of perceived undergraduate engagement in professional development activities. An 11-item measure of PDE exhibited a good reliability. Using a complete data sample of 467 graduating business undergraduates, four variable sets (student background or precollege variables,…

Investigating systematic individual differences in sleep-deprived performance on a high-fidelity flight simulator.

PubMed

Van Dongen, Hans P A; Caldwell, John A; Caldwell, J Lynn

2006-05-01

Laboratory research has revealed considerable systematic variability in the degree to which individuals' alertness and performance are affected by sleep deprivation. However, little is known about whether or not different populations exhibit similar levels of individual variability. In the present study, we examined individual variability in performance impairment due to sleep loss in a highly select population of militaryjet pilots. Ten active-duty F-117 pilots were deprived of sleep for 38 h and studied repeatedly in a high-fidelity flight simulator. Data were analyzed with a mixed-model ANOVA to quantify individual variability. Statistically significant, systematic individual differences in the effects of sleep deprivation were observed, even when baseline differences were accounted for. The findings suggest that highly select populations may exhibit individual differences in vulnerability to performance impairment from sleep loss just as the general population does. Thus, the scientific and operational communities' reliance on group data as opposed to individual data may entail substantial misestimation of the impact of job-related stressors on safety and performance.

Simulated sensitivity of seasonal ozone exposure in the Great Lakes region to changes in anthropogenic emissions in the presence of interannual variability

Treesearch

Jerome D. Fast; Warren E. Heilman

2005-01-01

A coupled meteorological and chemical modeling system with a 12-km horizontal grid spacing was used to simulate the evolution of ozone over the Great Lakes region between May and September of 1999 and 2001. The overall temporal and spatial variations in hourly ozone concentrations and ozone exposure from control simulations agreed reasonably well with the observations...

Complex watersheds, collaborative teams: Assessing pollutant presence and effects in the San Francisco Delta

EPA Science Inventory

There is a great diversity of sources of chemical contaminants and stressors over large geographic areas. Chemical contaminant inputs and magnitude can potentially exhibit wide seasonal variation over large geographic areas. Together, these factors make linking exposure to monito...

Lake Michigan nearshore: How modeling scenarios can improve dialog between modelers and ecologists

EPA Science Inventory

The nearshore of Lake Michigan, similarly to the other Great Lakes, experiences environmental concerns due to excessive eutrophication. Assessing the nearshore is challenging because fluctuating nutrient loads, and ever-changing currents cause this area to exhibit large spatial a...

Fatigue Resistance of Al-Cu-Li and Comparison with 7xxx Aerospace Alloys

NASA Astrophysics Data System (ADS)

Daniélou, A.; Ronxin, J. P.; Nardin, C.; Ehrström, J. C.

Al-Cu-Li alloys are of great interest for aerospace applications due to their good mechanical property balance, excellent corrosion resistance and reduced density. These alloys exhibit an increased resistance to fatigue in particular when compared to 7xxx alloys.

Human embryonic and induced pluripotent stem cell-derived cardiomyocytes exhibit beat rate variability and power-law behavior.

PubMed

Mandel, Yael; Weissman, Amir; Schick, Revital; Barad, Lili; Novak, Atara; Meiry, Gideon; Goldberg, Stanislav; Lorber, Avraham; Rosen, Michael R; Itskovitz-Eldor, Joseph; Binah, Ofer

2012-02-21

The sinoatrial node is the main impulse-generating tissue in the heart. Atrioventricular conduction block and arrhythmias caused by sinoatrial node dysfunction are clinically important and generally treated with electronic pacemakers. Although an excellent solution, electronic pacemakers incorporate limitations that have stimulated research on biological pacing. To assess the suitability of potential biological pacemakers, we tested the hypothesis that the spontaneous electric activity of human embryonic stem cell-derived cardiomyocytes (hESC-CMs) and induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) exhibit beat rate variability and power-law behavior comparable to those of human sinoatrial node. We recorded extracellular electrograms from hESC-CMs and iPSC-CMs under stable conditions for up to 15 days. The beat rate time series of the spontaneous activity were examined in terms of their power spectral density and additional methods derived from nonlinear dynamics. The major findings were that the mean beat rate of hESC-CMs and iPSC-CMs was stable throughout the 15-day follow-up period and was similar in both cell types, that hESC-CMs and iPSC-CMs exhibited intrinsic beat rate variability and fractal behavior, and that isoproterenol increased and carbamylcholine decreased the beating rate in both hESC-CMs and iPSC-CMs. This is the first study demonstrating that hESC-CMs and iPSC-CMs exhibit beat rate variability and power-law behavior as in humans, thus supporting the potential capability of these cell sources to serve as biological pacemakers. Our ability to generate sinoatrial-compatible spontaneous cardiomyocytes from the patient's own hair (via keratinocyte-derived iPSCs), thus eliminating the critical need for immunosuppression, renders these myocytes an attractive cell source as biological pacemakers.

Room temperature ferroelectricity in one-dimensional single chain molecular magnets [{M(Δ)M(Λ)}(ox)2(phen)2]n (M = Fe and Mn)

NASA Astrophysics Data System (ADS)

Bhatt, Pramod; Mukadam, M. D.; Meena, S. S.; Mishra, S. K.; Mittal, R.; Sastry, P. U.; Mandal, B. P.; Yusuf, S. M.

2017-03-01

The ferroelectric materials are mainly focused on pure inorganic oxides; however, the organic molecule based materials have recently attracted great attention because of their multifunctional properties. The mixing of oxalate and phenanthroline ligands with metal ions (Fe or Mn) at room temperature followed by hydrothermal treatment results in the formation of one-dimensional single chain molecular magnets which exhibit room temperature dielectric and ferroelectric behavior. The compounds are chiral in nature, and exhibit a ferroelectric behavior, attributed to the polar point group C2, in which they crystallized. The compounds are also associated with a dielectric loss and thus a relaxation process. The observed electric dipole moment, essential for a ferroelectricity, has been understood quantitatively in terms of lattice distortions at two different lattice sites within the crystal structure. The studied single chain molecular magnetic materials with room temperature ferroelectric and dielectric properties could be of great technological importance in non-volatile memory elements, and high-performance insulators.

Decreasing transmembrane segment length greatly decreases perfringolysin O pore size

DOE PAGES

Lin, Qingqing; Li, Huilin; Wang, Tong; ...

2015-04-08

Perfringolysin O (PFO) is a transmembrane (TM) β-barrel protein that inserts into mammalian cell membranes. Once inserted into membranes, PFO assembles into pore-forming oligomers containing 30–50 PFO monomers. These form a pore of up to 300 Å, far exceeding the size of most other proteinaceous pores. In this study, we found that altering PFO TM segment length can alter the size of PFO pores. A PFO mutant with lengthened TM segments oligomerized to a similar extent as wild-type PFO, and exhibited pore-forming activity and a pore size very similar to wild-type PFO as measured by electron microscopy and a leakagemore » assay. In contrast, PFO with shortened TM segments exhibited a large reduction in pore-forming activity and pore size. This suggests that the interaction between TM segments can greatly affect the size of pores formed by TM β-barrel proteins. PFO may be a promising candidate for engineering pore size for various applications.« less

Snow-atmosphere coupling and its impact on temperature variability and extremes over North America

NASA Astrophysics Data System (ADS)

Diro, G. T.; Sushama, L.; Huziy, O.

2018-04-01

The impact of snow-atmosphere coupling on climate variability and extremes over North America is investigated using modeling experiments with the fifth generation Canadian Regional Climate Model (CRCM5). To this end, two CRCM5 simulations driven by ERA-Interim reanalysis for the 1981-2010 period are performed, where snow cover and depth are prescribed (uncoupled) in one simulation while they evolve interactively (coupled) during model integration in the second one. Results indicate systematic influence of snow cover and snow depth variability on the inter-annual variability of soil and air temperatures during winter and spring seasons. Inter-annual variability of air temperature is larger in the coupled simulation, with snow cover and depth variability accounting for 40-60% of winter temperature variability over the Mid-west, Northern Great Plains and over the Canadian Prairies. The contribution of snow variability reaches even more than 70% during spring and the regions of high snow-temperature coupling extend north of the boreal forests. The dominant process contributing to the snow-atmosphere coupling is the albedo effect in winter, while the hydrological effect controls the coupling in spring. Snow cover/depth variability at different locations is also found to affect extremes. For instance, variability of cold-spell characteristics is sensitive to snow cover/depth variation over the Mid-west and Northern Great Plains, whereas, warm-spell variability is sensitive to snow variation primarily in regions with climatologically extensive snow cover such as northeast Canada and the Rockies. Furthermore, snow-atmosphere interactions appear to have contributed to enhancing the number of cold spell days during the 2002 spring, which is the coldest recorded during the study period, by over 50%, over western North America. Additional results also provide useful information on the importance of the interactions of snow with large-scale mode of variability in modulating temperature extreme characteristics.

Power Supply for Variable Frequency Induction Heating Using MERS Soft-Switching High Frequency Inverter

NASA Astrophysics Data System (ADS)

Isobe, Takanori; Kitahara, Tadayuki; Fukutani, Kazuhiko; Shimada, Ryuichi

Variable frequency induction heating has great potential for industrial heating applications due to the possibility of achieving heating distribution control; however, large-scale induction heating with variable frequency has not yet been introduced for practical use. This paper proposes a high frequency soft-switching inverter for induction heating that can achieve variable frequency operation. One challenge of variable frequency induction heating is increasing power electronics ratings. This paper indicates that its current source type dc-link configuration and soft-switching characteristics can make it possible to build a large-scale system with variable frequency capability. A 90-kVA 150-1000Hz variable frequency experimental power supply for steel strip induction heating was developed. Experiments confirmed the feasibility of variable frequency induction heating with proposed converter and the advantages of variable frequency operation.

Linkages Between Multiscale Global Sea Surface Temperature Change and Precipitation Variabilities in the US

NASA Technical Reports Server (NTRS)

Lau, K. M.; Weng, Heng-Yi

1999-01-01

A growing number of evidence indicates that there are coherent patterns of variability in sea surface temperature (SST) anomaly not only at interannual timescales, but also at decadal-to-inter-decadal timescale and beyond. The multi-scale variabilities of SST anomaly have shown great impacts on climate. In this work, we analyze multiple timescales contained in the globally averaged SST anomaly with and their possible relationship with the summer and winter rainfall in the United States over the past four decades.

WEATHER ON OTHER WORLDS. III. A SURVEY FOR T DWARFS WITH HIGH-AMPLITUDE OPTICAL VARIABILITY

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

Heinze, Aren N.; Metchev, Stanimir; Kellogg, Kendra, E-mail: aren.heinze@stonybrook.edu, E-mail: smetchev@uwo.ca

2015-03-10

We have monitored 12 T dwarfs with the Kitt Peak 2.1 m telescope using an F814W filter (0.7-0.95 μm) to place in context the remarkable 10%-20% variability exhibited by the nearby T dwarf Luhman 16B in this wavelength regime. The motivation was the poorly known red optical behavior of T dwarfs, which have been monitored almost exclusively at infrared wavelengths, where variability amplitudes greater than 10% have been found to be very rare. We detect highly significant variability in two T dwarfs. The T2.5 dwarf 2MASS 13243559+6358284 shows consistent ∼17% variability on two consecutive nights. The T2 dwarf 2MASS J16291840+0335371 exhibits ∼10% variability thatmore » may evolve from night to night, similarly to Luhman 16B. Both objects were previously known to be variable in the infrared, but with considerably lower amplitudes. We also find evidence for variability in the T6 dwarf J162414.37+002915.6, but since it has lower significance, we conservatively refrain from claiming this object as a variable. We explore and rule out various telluric effects, demonstrating that the variations we detect are astrophysically real. We suggest that high-amplitude photometric variability for T dwarfs is likely more common in the red optical than at longer wavelengths. The two new members of the growing class of high-amplitude variable T dwarfs offer excellent prospects for further study of cloud structures and their evolution.« less

Reproductive success and contaminant associations in tree swallows (Tachycineta bicolor) used to assess a Beneficial Use Impairment in U.S. and Binational Great Lakes’ Areas of Concern

USGS Publications Warehouse

Custer, Christine M.; Custer, Thomas W.; Etterson, Matthew A.; Dummer, Paul; Goldberg, Diana R.; Franson, J. Christian

2018-01-01

During 2010-2014, tree swallow (Tachycineta bicolor) reproductive success was monitored at 68 sites across all 5 Great Lakes, including 58 sites located within Great Lakes Areas of Concern (AOCs) and 10 non-AOCs. Sample eggs were collected from tree swallow clutches and analyzed for contaminants including polychlorinated biphenyls (PCBs), dioxins and furans, polybrominated diphenyl ethers, and 34 other organic compounds. Contaminant data were available for 360 of the clutches monitored. Markov chain multistate modeling was used to assess the importance of 5 ecological variables and 11 of the dominant contaminants in explaining the pattern of egg and nestling failure rates. Four of 5 ecological variables (Female Age, Date within season, Year, and Site) were important explanatory variables. Of the 11 contaminants, only total dioxin and furan toxic equivalents (TEQs) explained a significant amount of the egg failure probabilities. Neither total PCBs nor PCB TEQs explained the variation in egg failure rates. In a separate analysis, polycyclic aromatic hydrocarbon exposure in nestling diet, used as a proxy for female diet during egg laying, was significantly correlated with the daily probability of egg failure. The 8 sites within AOCs which had poorer reproduction when compared to 10 non-AOC sites, the measure of impaired reproduction as defined by the Great Lakes Restoration Initiative, were associated with exposure to dioxins and furan TEQs, PAHs, or depredation. Only 2 sites had poorer reproduction than the poorest performing non-AOC. Using a classic (non-modeling) approach to estimating reproductive success, 82% of nests hatched at least 1 egg, and 75% of eggs laid, excluding those collected for contaminant analyses, hatched.

Reproductive success and contaminant associations in tree swallows (Tachycineta bicolor) used to assess a Beneficial Use Impairment in U.S. and Binational Great Lakes' Areas of Concern.

PubMed

Custer, Christine M; Custer, Thomas W; Etterson, Matthew A; Dummer, Paul M; Goldberg, Diana; Franson, J Christian

2018-05-01

During 2010-2014, tree swallow (Tachycineta bicolor) reproductive success was monitored at 68 sites across all 5 Great Lakes, including 58 sites located within Great Lakes Areas of Concern (AOCs) and 10 non-AOCs. Sample eggs were collected from tree swallow clutches and analyzed for contaminants including polychlorinated biphenyls (PCBs), dioxins and furans, polybrominated diphenyl ethers, and 34 other organic compounds. Contaminant data were available for 360 of the clutches monitored. Markov chain multistate modeling was used to assess the importance of 5 ecological variables and 11 of the dominant contaminants in explaining the pattern of egg and nestling failure rates. Four of 5 ecological variables (Female Age, Date within season, Year, and Site) were important explanatory variables. Of the 11 contaminants, only total dioxin and furan toxic equivalents (TEQs) explained a significant amount of the egg failure probabilities. Neither total PCBs nor PCB TEQs explained the variation in egg failure rates. In a separate analysis, polycyclic aromatic hydrocarbon exposure in nestling diet, used as a proxy for female diet during egg laying, was significantly correlated with the daily probability of egg failure. The 8 sites within AOCs which had poorer reproduction when compared to 10 non-AOC sites, the measure of impaired reproduction as defined by the Great Lakes Restoration Initiative, were associated with exposure to dioxins and furan TEQs, PAHs, or depredation. Only 2 sites had poorer reproduction than the poorest performing non-AOC. Using a classic (non-modeling) approach to estimating reproductive success, 82% of nests hatched at least 1 egg, and 75% of eggs laid, excluding those collected for contaminant analyses, hatched.

KSC-04PD-2221

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. An exhibit of safety glasses, gloves and protective covers is one of many displayed at KSC during Spaceport Super Safety and Health Day. The event included guest speakers Dr. Pamela Peeke, Navy Com. Stephen E. Iwanowicz, NASAs Dr. Kristine Calderon and Olympic-great Bruce Jenner. In addition, many vendors exhibits were on display for employees. Super Safety and Health Day was initiated at KSC in 1998 to increase awareness of the importance of safety and health among the government and contractor workforce. The theme for this years event was Safety and Health: A Winning Combination.

KSC-04PD-2220

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. KSC Employees stop by the American Red Cross exhibit during Spaceport Super Safety and Health Day. The event included guest speakers Dr. Pamela Peeke, Navy Com. Stephen E. Iwanowicz, NASAs Dr. Kristine Calderon and Olympic-great Bruce Jenner. In addition, many vendors exhibits were on display for employees. Super Safety and Health Day was initiated at KSC in 1998 to increase awareness of the importance of safety and health among the government and contractor workforce. The theme for this years event was Safety and Health: A Winning Combination.

KSC-04PD-2219

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. KSC employees learn about a mechanical robot displayed at an exhibit during Spaceport Super Safety and Health Day. The event included guest speakers Dr. Pamela Peeke, Navy Com. Stephen E. Iwanowicz, NASAs Dr. Kristine Calderon and Olympic-great Bruce Jenner. In addition, many vendors exhibits were on display for employees. Super Safety and Health Day was initiated at KSC in 1998 to increase awareness of the importance of safety and health among the government and contractor workforce. The theme for this years event was Safety and Health: A Winning Combination.

Does the intrathecal propofol have a neuroprotective effect on spinal cord ischemia?

PubMed Central

Sahin, Murat; Gullu, Huriye; Peker, Kemal; Sayar, Ilyas; Binici, Orhan; Yildiz, Huseyin

2015-01-01

The neuroprotective effects of propofol have been confirmed. However, it remains unclear whether intrathecal administration of propofol exhibits neuroprotective effects on spinal cord ischemia. At 1 hour prior to spinal cord ischemia, propofol (100 and 300 µg) was intrathecally administered in rats with spinal cord ischemia. Propofol pre-treatment greatly improved rat pathological changes and neurological function deficits at 24 hours after spinal cord ischemia. These results suggest that intrathecal administration of propofol exhibits neuroprotective effects on spinal cord structural and functional damage caused by ischemia. PMID:26807119

Does the intrathecal propofol have a neuroprotective effect on spinal cord ischemia?

PubMed

Sahin, Murat; Gullu, Huriye; Peker, Kemal; Sayar, Ilyas; Binici, Orhan; Yildiz, Huseyin

2015-11-01

The neuroprotective effects of propofol have been confirmed. However, it remains unclear whether intrathecal administration of propofol exhibits neuroprotective effects on spinal cord ischemia. At 1 hour prior to spinal cord ischemia, propofol (100 and 300 µg) was intrathecally administered in rats with spinal cord ischemia. Propofol pre-treatment greatly improved rat pathological changes and neurological function deficits at 24 hours after spinal cord ischemia. These results suggest that intrathecal administration of propofol exhibits neuroprotective effects on spinal cord structural and functional damage caused by ischemia.

A probabilistic approach to modeling erosion for spatially-varied conditions

Treesearch

William J. Elliot; Peter R. Robichaud; C. D. Pannkuk

2001-01-01

In the years following a major forest disturbance, such as fire, the erosion rate is greatly influenced by variability in weather, in soil properties, and in spatial distribution. This paper presents a method to incorporate these variabilities into the erosion rate predicted by the Water Erosion Prediction Project model. It appears that it is not necessary to describe...

Fuels planning: science synthesis and integration; economic uses fact sheet 08: prescribed fire costs

Treesearch

Rocky Mountain Research Station USDA Forest Service

2004-01-01

Although the use of prescribed fire as a management tool is widespread, there is great variability and uncertainty in the treatment costs. Given specific site variables and management objectives, how much will it cost to use prescribed fire? This paper describes the FASTRACS database, a tool that has been developed to aid managers in addressing this question.

The Use of Biofeedback to Augment the Acquisition of Skills in Performing Joint Mobilization Techniques among Physical Therapy Students

ERIC Educational Resources Information Center

Timmerberg, Jean Fitzpatrick

2011-01-01

Despite the frequent use of joint mobilizations and the available evidence of its effectiveness as a treatment for various musculoskeletal disorders, it is a technique that has been shown to have great variability within and between raters. This variability is believed to occur because of differences between therapists' ability to perceive…

A Study on the Characteristics of Design Variables for IRSS Diffuser

NASA Astrophysics Data System (ADS)

Cho, Yong-Jin; Ko, Dae-Eun

2017-11-01

In modern naval ships, infrared signature suppression systems (IRSS) are installed to decrease the temperature of waste gas generated in propulsion engine and the metallic surface temperature of heated exhaust pipes. Generally, IRSS is composed of eductor, mixing tube, and diffuser. Diffuser serves to reduce the temperature by creating an air film using the pressure difference between internal gas and external air. In this study, design variables were selected by analyzing the diffuser and the characteristics of design variables that affect the performance of diffuser were examined using Taguchi experiment method. For the diffuser performance analysis, a heat flow analysis technique established in previous research was used. The IRSS performance evaluation was carried out based on the average area value of the metal surface temperature and the temperature of the exhaust gas at the outlet of the diffuser, which are variables directly related to the intensity of infrared signature in naval ships. It was verified that the exhaust gas temperature is greatly affected by changes in the diameter of the diffuser outlet, and the metal surface temperature of diffuser is greatly affected by changes in the number of diffuser rings.

Sex differences and plasticity in dehydration tolerance: insight from a tropical liverwort.

PubMed

Marks, Rose A; Burton, James F; McLetchie, D Nicholas

2016-08-01

Adaptations allowing plants to cope with drying are particularly relevant in the light of predicted climate change. Dehydration tolerance (DhT, also dehydration-tolerant) is one such adaptation enabling tissue to survive substantial drying. A great deal of work has been conducted on highly DhT species. However, bryophytes showing less intense and variable DhT are understudied, despite the potential for these species to provide an informative link between highly tolerant and sensitive species. In this study, we tested the degree to which DhT varies across populations and the sexes of a species expected to exhibit a moderate DhT phenotype. To test predicted patterns of tolerance we assessed DhT in males and females of Marchantia inflexa from two distinct habitat types that differ in water availability. Both common garden and field-collected tissue was subjected to drying assays at multiple intensities and recovery was monitored by chlorophyll florescence. Verification studies were conducted to confirm the level of dehydration, the rate of drying and the associated changes in photosynthetic physiology. We confirmed our expectation that M. inflexa is able to tolerate moderate dehydration. We also found that females exhibited higher DhT than males, but populations did not differ in DhT when cultured in a common garden. However, field-collected samples exhibited differences in DhT corresponding to environmental dryness, suggesting plasticity in DhT. By studying a less extreme DhT phenotype we gained insight into how more sensitive (yet still tolerant) organisms cope with dehydration. Additionally, the identified sex-specific variation in DhT may explain ecological patterns such as female-biased sex ratios. Furthermore, plasticity in DhT has the potential to inform management practices aimed at increasing tolerance to drought conditions. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Regional sea level projections with observed gauge, altimeter and reconstructed data along China coast

NASA Astrophysics Data System (ADS)

Du, L.; Shi, H.; Zhang, S.

2017-12-01

Acting as the typical shelf seas in northwest Pacific Ocean, regional sea level along China coasts exhibits complicated and multiscale spatial-temporal characteristics under circumstance of global change. In this paper, sea level variability is investigated with tide gauges records, satellite altimetry data, reconstructed sea surface height, and CMIP simulation fields. Sea level exhibits the interannual variability imposing on a remarkable sea level rising in the China seas and coastal region, although its seasonal signals are significant as the results of global ocean. Sea level exhibits faster rising rate during the satellite altimetry era, nearly twice to the rate during the last sixty years. AVISO data and reconstructed sea surface heights illustrate good correlation coefficient, more than 0.8. Interannual sea level variation is mainly modulated by the low-frequency variability of wind fields over northern Pacific Ocean by local and remote processes. Meanwhile sea level varies obviously by the transport fluctuation and bimodality path of Kuroshio. Its variability possibly linked to internal variability of the ocean-atmosphere system influenced by ENSO oscillation. China Sea level have been rising during the 20th century, and are projected to continue to rise during this century. Sea level can reach the highest extreme level in latter half of 21st century. Modeled sea level including regional sea level projection combined with the IPCC climate scenarios play a significant role on coastal storm surge evolution. The vulnerable regions along the ECS coast will suffer from the increasing storm damage with sea level variations.

Association of monthly frequencies of diverse diseases in the calls to the public emergency service of the city of Buenos Aires during 1999-2004 with meteorological variables and seasons.

PubMed

Alexander, P

2013-01-01

This work aims to study associations between monthly averages of meteorological variables and monthly frequencies of diverse diseases in the calls to the public ambulance emergency service of the city of Buenos Aires during the years 1999-2004. Throughout this time period no changes were made in the classification codes of the illnesses. Heart disease, arrhythmia, heart failure, cardiopulmonary arrest, angina pectoris, psychiatric diseases, stroke, transient ischemic attack, syncope and the total number of calls were analyzed against 11 weather variables and the four seasons. All illnesses exhibited some seasonal behavior, except cardiorespiratory arrest and angina pectoris. The largest frequencies of illnesses that exhibited some association with the meteorological variables used to occur in winter, except the psychiatric cases. Heart failure, stroke, psychiatric diseases and the total number of calls showed significant correlations with the 11 meteorological variables considered, and the largest indices (absolute values above 0.6) were found for the former two pathologies. On the other side, cardiorespiratory arrest and angina pectoris revealed no significant correlations and nearly null indices. Variables associated with temperature were the meteorological proxies with the largest correlations against diseases. Pressure and humidity mostly exhibited positive correlations, which is the opposite of variables related to temperature. Contrary to all other diseases, psychiatric pathologies showed a clear predominance of positive correlations. Finally, the association degree of the medical dataset with recurrent patterns was further evaluated through Fourier analysis, to assess the presence of statistically significant behavior. In the Northern Hemisphere high morbidity and mortality rates in December are usually assigned to diverse factors in relation to the holidays, but such an effect is not observed in the present analysis. There seems to be no clearly preferred meteorological proxy among the different types of temperatures used. It is shown that the amount of occurrences depends mainly on season rather on its strength quantified by temperature.

Association of monthly frequencies of diverse diseases in the calls to the public emergency service of the city of Buenos Aires during 1999-2004 with meteorological variables and seasons

NASA Astrophysics Data System (ADS)

Alexander, P.

2013-01-01

This work aims to study associations between monthly averages of meteorological variables and monthly frequencies of diverse diseases in the calls to the public ambulance emergency service of the city of Buenos Aires during the years 1999-2004. Throughout this time period no changes were made in the classification codes of the illnesses. Heart disease, arrhythmia, heart failure, cardiopulmonary arrest, angina pectoris, psychiatric diseases, stroke, transient ischemic attack, syncope and the total number of calls were analyzed against 11 weather variables and the four seasons. All illnesses exhibited some seasonal behavior, except cardiorespiratory arrest and angina pectoris. The largest frequencies of illnesses that exhibited some association with the meteorological variables used to occur in winter, except the psychiatric cases. Heart failure, stroke, psychiatric diseases and the total number of calls showed significant correlations with the 11 meteorological variables considered, and the largest indices (absolute values above 0.6) were found for the former two pathologies. On the other side, cardiorespiratory arrest and angina pectoris revealed no significant correlations and nearly null indices. Variables associated with temperature were the meteorological proxies with the largest correlations against diseases. Pressure and humidity mostly exhibited positive correlations, which is the opposite of variables related to temperature. Contrary to all other diseases, psychiatric pathologies showed a clear predominance of positive correlations. Finally, the association degree of the medical dataset with recurrent patterns was further evaluated through Fourier analysis, to assess the presence of statistically significant behavior. In the Northern Hemisphere high morbidity and mortality rates in December are usually assigned to diverse factors in relation to the holidays, but such an effect is not observed in the present analysis. There seems to be no clearly preferred meteorological proxy among the different types of temperatures used. It is shown that the amount of occurrences depends mainly on season rather on its strength quantified by temperature.

Forecasting space weather over short horizons: Revised and updated estimates

NASA Astrophysics Data System (ADS)

Reikard, Gordon

2018-07-01

Space weather reflects multiple causes. There is a clear influence for the sun on the near-earth environment. Solar activity shows evidence of chaotic properties, implying that prediction may be limited beyond short horizons. At the same time, geomagnetic activity also reflects the rotation of the earth's core, and local currents in the ionosphere. The combination of influences means that geomagnetic indexes behave like multifractals, exhibiting nonlinear variability, with intermittent outliers. This study tests a range of models: regressions, neural networks, and a frequency domain algorithm. Forecasting tests are run for sunspots and irradiance from 1820 onward, for the Aa geomagnetic index from 1868 onward, and the Am index from 1959 onward, over horizons of 1-7 days. For irradiance and sunspots, persistence actually does better over short horizons. None of the other models really dominate. For the geomagnetic indexes, the persistence method does badly, while the neural net also shows large errors. The remaining models all achieve about the same level of accuracy. The errors are in the range of 48% at 1 day, and 54% at all later horizons. Additional tests are run over horizons of 1-4 weeks. At 1 week, the best models reduce the error to about 35%. Over horizons of four weeks, the model errors increase. The findings are somewhat pessimistic. Over short horizons, geomagnetic activity exhibits so much random variation that the forecast errors are extremely high. Over slightly longer horizons, there is some improvement from estimating in the frequency domain, but not a great deal. Including solar activity in the models does not yield any improvement in accuracy.

Tricyclic antidepressants exhibit variable pharmacological profiles at the α2A adrenergic receptor

PubMed Central

Cottingham, Christopher; Percival, Stefanie; Birky, Tana; Wang, Qin

2014-01-01

Antidepressant mechanisms of action remain shrouded in mystery, greatly hindering our ability to develop therapeutics which can fully treat patients suffering from depressive disorders. In an attempt to shed new light on this topic, we have undertaken a series of studies investigating actions of tricyclic antidepressant drugs (TCAs) at the α2A adrenergic receptor (AR), a centrally important receptor, dysregulation of which has been linked to depression. Our previous work established a particular TCA, desipramine, as an arrestin-biased α2AAR ligand driving receptor endocytosis and downregulation but not canonical heterotrimeric G protein-mediated signaling. The present work is aimed at broadening our understanding of how members of the TCA drug class act at the α2AAR, as we have selected the closely related but subtly different TCAs imipramine and amitriptyline for evaluation. Our data demonstrate that these drugs do also function as direct arrestin-biased α2AAR ligands. However, these data reveal differences in receptor affinity and in the extent/nature of arrestin recruitment to and endocytosis of α2AARs. Specifically, amitriptyline exhibits an approximately 14-fold stronger interaction with the receptor, is a weaker driver of arrestin recruitment, and preferentially recruits a different arrestin subtype. Extent of endocytosis is similar for all TCAs studied so far, and occurs in an arrestin-dependent manner, although imipramine uniquely retains a slight ability to drive α2AAR endocytosis in arrestin-null cells. These findings signify an important expansion of our mechanistic understanding of antidepressant pharmacology, and provide useful insights for future medicinal chemistry efforts. PMID:25128275

Enhancing the Remote Variable Operations in NPSS/CCDK

NASA Technical Reports Server (NTRS)

Sang, Janche; Follen, Gregory; Kim, Chan; Lopez, Isaac; Townsend, Scott

2001-01-01

Many scientific applications in aerodynamics and solid mechanics are written in Fortran. Refitting these legacy Fortran codes with distributed objects can increase the code reusability. The remote variable scheme provided in NPSS/CCDK helps programmers easily migrate the Fortran codes towards a client-server platform. This scheme gives the client the capability of accessing the variables at the server site. In this paper, we review and enhance the remote variable scheme by using the operator overloading features in C++. The enhancement enables NPSS programmers to use remote variables in much the same way as traditional variables. The remote variable scheme adopts the lazy update approach and the prefetch method. The design strategies and implementation techniques are described in details. Preliminary performance evaluation shows that communication overhead can be greatly reduced.

A Multidisciplinary First-Year Seminar about Tuberculosis.

ERIC Educational Resources Information Center

Fluck, Richard A.

2001-01-01

Describes a writing intensive seminar for college freshman. Includes goals, reading assignments, writing assignments, and group projects. Provides web-based resources on tuberculosis along with an evaluation sheet for web site reviews. Concludes that students exhibited great interest in the topic and course feedback was positive. (DLH)

Great Basin sagebrush ecosystems

Treesearch

Jeanne C. Chambers

2008-01-01

Sagebrush ecosystems exhibit widespread degradation due to a variety of causes, including invasion by exotic plants, expansion of pinyon and juniper, altered fire regimes, excessive livestock grazing, urbanization and land development, conversion to agriculture, road development and use, mining, and energy development. These ecosystems have been identified as the most...

Composition and structural features of condensed tannins from Texas legumes exhibiting methane abatement activity during in vitro rumen digestion

USDA-ARS?s Scientific Manuscript database

Previous studies showed that a series of purified condensed tannins (CTs) from warm-season perennial legumes exhibited high variability in their modulation of methane production during in vitro rumen digestion. The molecular weight difference of these CTs did not provide correlation with either the ...

Self-reported coping behavior in health and disease: assessment with a card sort game

NASA Technical Reports Server (NTRS)

Schwartz, C. E.; Peng, C. K.; Lester, N.; Daltroy, L. H.; Goldberger, A. L.

1998-01-01

The authors tested the hypothesis that individuals with a variety of severe chronic illnesses and the healthy elderly exhibit a loss of flexibility in their response to a variety of stressors, compared with healthy adults. A card sort game designed to assess self-reported coping behavior under different stressful life situations was used to compare healthy adults with individuals with multiple sclerosis, rheumatoid arthritis, systemic lupus erythematosus, and the elderly. The healthy adults were found to exhibit more variability than any of the illness groups or the elderly. Healthy function is marked by a complex type of variability.

Actor–Partner Interdependence Model Analysis of Sexual Communication and Relationship/Family Planning Factors Among Immigrant Latino Couples in the United States

PubMed Central

Matsuda, Yui

2017-01-01

The Latino population in the United States is quickly growing, and its unintended pregnancy rate is increasing. To decrease unintended pregnancies, couples must mutually agree on family planning. Communication between partners is one key factor identified in successful family planning for couples. Therefore, the purpose of this study was to examine sexual communication and its associations with sexual relationship power, general communication, and views on family planning. The Actor–Partner Interdependence Model was used to analyze dyadic influences of the chosen variables. Forty immigrant Latino couples were recruited from prenatal care clinics. The study results were grouped according to the three types of power structures: exhibition of men’s traditional machismo values, exhibition of women’s increased power in their relationships, and exhibition of men’s and women’s own empowerment with sexual communication. There was a negative association between men’s views on family planning and women’s sexual communication (exhibition of machismo values); a negative association between women’s sexual relationship power and their partners’ sexual communication (exhibition of women’s increased power); and positive associations between men’s and women’s general communication and sexual communication (exhibition of men’s and women’s own empowerment). Dyadic influences of sexual communication and associated variables need to be incorporated into interventions to facilitate family planning for couples. PMID:27367797

Global-scale modes of surface temperature variability on interannual to century timescales

NASA Technical Reports Server (NTRS)

Mann, Michael E.; Park, Jeffrey

1994-01-01

Using 100 years of global temperature anomaly data, we have performed a singluar value decomposition of temperature variations in narrow frequency bands to isolate coherent spatio-temporal modes of global climate variability. Statistical significance is determined from confidence limits obtained by Monte Carlo simulations. Secular variance is dominated by a globally coherent trend; with nearly all grid points warming in phase at varying amplitude. A smaller, but significant, share of the secular variance corresponds to a pattern dominated by warming and subsequent cooling in the high latitude North Atlantic with a roughly centennial timescale. Spatial patterns associated with significant peaks in variance within a broad period range from 2.8 to 5.7 years exhibit characteristic El Nino-Southern Oscillation (ENSO) patterns. A recent transition to a regime of higher ENSO frequency is suggested by our analysis. An interdecadal mode in the 15-to-18 years period and a mode centered at 7-to-8 years period both exhibit predominantly a North Atlantic Oscillation (NAO) temperature pattern. A potentially significant decadal mode centered on 11-to-12 years period also exhibits an NAO temperature pattern and may be modulated by the century-scale North Atlantic variability.

Comparative and familial analysis of handedness in great apes.

PubMed

Hopkins, William D

2006-07-01

Historically, population-level handedness has been considered a hallmark of human evolution. Whether nonhuman primates exhibit population-level handedness remains a topic of considerable debate. This paper summarizes published data on handedness in great apes. Comparative analysis indicated that chimpanzees and bonobos show population-level right handedness, whereas gorillas and orangutans do not. All ape species showed evidence of population-level handedness when considering specific tasks. Familial analyses in chimpanzees indicated that offspring and maternal (but not paternal) handedness was significantly positively correlated, but this finding was contingent upon the classification criteria used to evaluate hand preference. Overall, the proportion of right handedness is lower in great apes compared with humans, and various methodological and theoretical explanations for this discrepancy are discussed. Copyright (c) 2006 APA, all rights reserved.

Wave Height and Water Level Variability on Lakes Michigan and St Clair

DTIC Science & Technology

2012-10-01

Observations: http://www.ssec.wisc.edu/sose/glwx_activity.html 4. NASA Atlas of Extratropical Storm Tracks: http://data.giss.nasa.gov/stormtracks...term meteorological, ice, wave, and water level measurements. 15. SUBJECT TERMS Base flood elevation Coastal flood Extratropical storms Great...Box 1027 Detroit, MI 48231-1027 ERDC/CHL TR-12-23 ii Abstract The Great Lakes are subject to coastal flooding as a result of severe storms

Preventive physiotherapy interventions for back care in children and adolescents: a meta-analysis

PubMed Central

2012-01-01

Background Preventive interventions improve healthy behaviours and they also increase knowledge regarding back care in children and adolescents, but studies exhibit great variability in their contents, duration and number of sessions, and in the assessment methods. The purpose of this study was to review the empirical evidence regarding preventive physiotherapy interventions for back care in children and adolescents, and to ascertain the most efficacious treatments, in what way and under which circumstances. Methods Studies were located from computerized databases (Cochrane Library, Medline, PEDro, Web of Science and IME) and other sources. The search period extended to May 2012. To be included in the meta-analysis, studies had to use physical therapy methodologies of preventive treatment on children and adolescents, and to compare a treatment and a control group. Treatment, participant, methodological, and extrinsic characteristics of the studies were coded. Two researchers independently coded all of the studies. As effect size indices, standardized mean differences were calculated for measures of behaviours and knowledge, both in the posttest and in the follow-up. The random and mixed-effects models were used for the statistical analyses and sensitivity analyses were carried out in order to check the robustness of the meta-analytic results. Results A total of 19 papers fulfilled the selection criteria, producing 23 independent studies. On average, the treatments reached a statistically significant effectiveness in the behaviours acquired, both in the posttest and in the follow-up (d+ = 1.33 and d+ = 1.80, respectively), as well as in measures of knowledge (posttest; d+ = 1.29; follow-up: d+ = 0.76). Depending on the outcome measure, the effect sizes were affected by different moderator variables, such as the type of treatment, the type of postural hygiene, the teaching method, or the use of paraprofessionals as cotherapists. Conclusions The interventions were successful in significantly increasing the behaviours and knowledge acquired both in the posttest and in the follow-up. The combined treatment of postural hygiene with physiotherapy exercise exhibited the best results. The small number of studies limits the generalizability of the results. PMID:22908965

Preventive physiotherapy interventions for back care in children and adolescents: a meta-analysis.

PubMed

Calvo-Muñoz, Inmaculada; Gómez-Conesa, Antonia; Sánchez-Meca, Julio

2012-08-21

Preventive interventions improve healthy behaviours and they also increase knowledge regarding back care in children and adolescents, but studies exhibit great variability in their contents, duration and number of sessions, and in the assessment methods. The purpose of this study was to review the empirical evidence regarding preventive physiotherapy interventions for back care in children and adolescents, and to ascertain the most efficacious treatments, in what way and under which circumstances. Studies were located from computerized databases (Cochrane Library, Medline, PEDro, Web of Science and IME) and other sources. The search period extended to May 2012. To be included in the meta-analysis, studies had to use physical therapy methodologies of preventive treatment on children and adolescents, and to compare a treatment and a control group. Treatment, participant, methodological, and extrinsic characteristics of the studies were coded. Two researchers independently coded all of the studies. As effect size indices, standardized mean differences were calculated for measures of behaviours and knowledge, both in the posttest and in the follow-up. The random and mixed-effects models were used for the statistical analyses and sensitivity analyses were carried out in order to check the robustness of the meta-analytic results. A total of 19 papers fulfilled the selection criteria, producing 23 independent studies. On average, the treatments reached a statistically significant effectiveness in the behaviours acquired, both in the posttest and in the follow-up (d+ = 1.33 and d+ = 1.80, respectively), as well as in measures of knowledge (posttest; d+ = 1.29; follow-up: d+ = 0.76). Depending on the outcome measure, the effect sizes were affected by different moderator variables, such as the type of treatment, the type of postural hygiene, the teaching method, or the use of paraprofessionals as cotherapists. The interventions were successful in significantly increasing the behaviours and knowledge acquired both in the posttest and in the follow-up. The combined treatment of postural hygiene with physiotherapy exercise exhibited the best results. The small number of studies limits the generalizability of the results.

The Importance of Distance to Resources in the Spatial Modelling of Bat Foraging Habitat

PubMed Central

Rainho, Ana; Palmeirim, Jorge M.

2011-01-01

Many bats are threatened by habitat loss, but opportunities to manage their habitats are now increasing. Success of management depends greatly on the capacity to determine where and how interventions should take place, so models predicting how animals use landscapes are important to plan them. Bats are quite distinctive in the way they use space for foraging because (i) most are colonial central-place foragers and (ii) exploit scattered and distant resources, although this increases flying costs. To evaluate how important distances to resources are in modelling foraging bat habitat suitability, we radio-tracked two cave-dwelling species of conservation concern (Rhinolophus mehelyi and Miniopterus schreibersii) in a Mediterranean landscape. Habitat and distance variables were evaluated using logistic regression modelling. Distance variables greatly increased the performance of models, and distance to roost and to drinking water could alone explain 86 and 73% of the use of space by M. schreibersii and R. mehelyi, respectively. Land-cover and soil productivity also provided a significant contribution to the final models. Habitat suitability maps generated by models with and without distance variables differed substantially, confirming the shortcomings of maps generated without distance variables. Indeed, areas shown as highly suitable in maps generated without distance variables proved poorly suitable when distance variables were also considered. We concluded that distances to resources are determinant in the way bats forage across the landscape, and that using distance variables substantially improves the accuracy of suitability maps generated with spatially explicit models. Consequently, modelling with these variables is important to guide habitat management in bats and similarly mobile animals, particularly if they are central-place foragers or depend on spatially scarce resources. PMID:21547076

The Great Plains low-level jet in 1.5C and 2C HAPPI simulations: Implications for changes in extreme climate events

NASA Astrophysics Data System (ADS)

Weaver, S. J.; Barcikowska, M. J.

2017-12-01

Global temperature targets have become the cornerstone for global climate policy discussions. Given the goal of the Paris Accord to limit the rise in global mean temperature to well below 2.0oC above pre-industrial levels, and pursue efforts toward the more ambitious 1.5oC goal, there is increasing focus in the climate science community on what the relative changes in regional climate extremes may be for these two scenarios. Despite the successes of major climate science modeling efforts, there is still a significant information gap regarding the regional and seasonal changes in some climate extremes over the U.S. as a function of these global mean temperature targets.During the spring and summer, large amounts of heat and moisture are transported northward into the central and eastern U.S. by the Great Plains Low-Level Jet (GPLLJ) - an atmospheric river which dominates the subcontinental scale climate variability during the warm half of the year. Accordingly, the GPLLJ and its vast spatiotemporal variability is highly influential over several types of extreme climate anomalies east of the Rocky Mountains, including, drought and pluvial events, tornadic activity, and the evolution of central U.S warming hole. Changes in the GPLLJ and its variability are probed from the perspective of several hundred climate realizations afforded by the availability of climate model experiments from the Half a degree additional warming, Prognosis, and Projected Impacts (HAPPI) effort - a suite of multi-model ensemble AMIP simulations forced by 1.5oC and 2oC levels of global warming. The multimodel analysis focuses on the variable magnitude of the seasonal changes in the mean GPLLJ and shifts in the extremes of the prominent modes of GPLLJ variability - both of which have implications for the future shifts in extreme climate events over the Great Plains, Midwest, and southeast regions of the U.S.

Variability in Ozone-Induced Pulmonary Injury and Inflammation in Healthy and Cardiovascular Compromised Rat Models

EPA Science Inventory

The molecular bases for variability in air pollutant-induced pulmonary injury due to underlying cardiovascular (CVD) and/or metabolic diseases are unknown. We hypothesized that healthy and genetic CVD-prone rat models will exhibit exacerbated response to acute ozone exposure depe...

Effect of solar loading on greenhouse containers used in transpiration efficiency screening

USDA-ARS?s Scientific Manuscript database

Earlier we described a simple high throughput method of screening sorghum for transpiration efficiency (TE). Subsequently it was observed that while results were consistent between lines exhibiting high and low TE, ranking between lines with similar TE was variable. We hypothesized that variable mic...

Temporal and spatial variability of wind resources in the United States as derived from the Climate Forecast System Reanalysis

Treesearch

Lejiang Yu; Shiyuan Zhong; Xindi Bian; Warren E. Heilman

2015-01-01

This study examines the spatial and temporal variability of wind speed at 80m above ground (the average hub height of most modern wind turbines) in the contiguous United States using Climate Forecast System Reanalysis (CFSR) data from 1979 to 2011. The mean 80-m wind exhibits strong seasonality and large spatial variability, with higher (lower) wind speeds in the...

Species interactions may help explain the erratic periodicity of whooping cough dynamics.

PubMed

Bhattacharyya, Samit; Ferrari, Matthew J; Bjørnstad, Ottar N

2017-12-14

Incidence of whooping cough exhibits variable dynamics across time and space. The periodicity of this disease varies from annual to five years in different geographic regions in both developing and developed countries. Many hypotheses have been put forward to explain this variability such as nonlinearity and seasonality, stochasticity, variable recruitment of susceptible individuals via birth, immunization, and immune boosting. We propose an alternative hypothesis to describe the variability in periodicity - the intricate dynamical variability of whooping cough may arise from interactions between its dominant etiological agents of Bordetella pertussis and Bordetella parapertussis. We develop a two-species age-structured model, where two pathogens are allowed to interact by age-dependent convalescence of individuals with severe illness from infections. With moderate strength of interactions, the model exhibits multi-annual coexisting attractors that depend on the R 0 of the two pathogens. We also examine how perturbation from case importation and noise in transmission may push the system from one dynamical regime to another. The coexistence of multi-annual cycles and the behavior of switching between attractors suggest that variable dynamics of whopping cough could be an emergent property of its multi-agent etiology. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Electrochemical characterization of nanodimensional metal oxide materials

NASA Astrophysics Data System (ADS)

Tang, Paul Enle

Energy storage devices have become a bottleneck in performance improvements for portable electronics. This research seeks to answer basic science questions that may lead to the necessary improvements. First, this work demonstrates that insertion of multivalent ions into vanadium oxide greatly exceeds the storage capacity of materials presently used. Second, this work demonstrates that potassium ferrate exhibits a uniquely large pseudocapacitive effect. This effect can be used to great advantage when high power density and high energy density are required. Lastly, this work proposes a model of pseudocapacitance that has a greater descriptive power than that of previous models.

Adaptive data-driven models for estimating carbon fluxes in the Northern Great Plains

USGS Publications Warehouse

Wylie, B.K.; Fosnight, E.A.; Gilmanov, T.G.; Frank, A.B.; Morgan, J.A.; Haferkamp, Marshall R.; Meyers, T.P.

2007-01-01

Rangeland carbon fluxes are highly variable in both space and time. Given the expansive areas of rangelands, how rangelands respond to climatic variation, management, and soil potential is important to understanding carbon dynamics. Rangeland carbon fluxes associated with Net Ecosystem Exchange (NEE) were measured from multiple year data sets at five flux tower locations in the Northern Great Plains. These flux tower measurements were combined with 1-km2 spatial data sets of Photosynthetically Active Radiation (PAR), Normalized Difference Vegetation Index (NDVI), temperature, precipitation, seasonal NDVI metrics, and soil characteristics. Flux tower measurements were used to train and select variables for a rule-based piece-wise regression model. The accuracy and stability of the model were assessed through random cross-validation and cross-validation by site and year. Estimates of NEE were produced for each 10-day period during each growing season from 1998 to 2001. Growing season carbon flux estimates were combined with winter flux estimates to derive and map annual estimates of NEE. The rule-based piece-wise regression model is a dynamic, adaptive model that captures the relationships of the spatial data to NEE as conditions evolve throughout the growing season. The carbon dynamics in the Northern Great Plains proved to be in near equilibrium, serving as a small carbon sink in 1999 and as a small carbon source in 1998, 2000, and 2001. Patterns of carbon sinks and sources are very complex, with the carbon dynamics tilting toward sources in the drier west and toward sinks in the east and near the mountains in the extreme west. Significant local variability exists, which initial investigations suggest are likely related to local climate variability, soil properties, and management.

Improved capture of stable flies (Diptera: Muscidae) by placement of knight stick sticky fly traps protected by electric fence inside animal exhibit yards at the Smithsonian's National Zoological Park.

PubMed

Hogsette, Jerome A; Ose, Gregory A

2017-12-01

Stable flies are noxious blood-feeding pests of exotic animals at zoological parks, inflicting painful bites, and causing discomfort to animals. Stable fly management is difficult because of the flies' tendency to remain on the host animals only when feeding. Non-toxic traps can be efficient but traps placed around exhibit perimeters captured fewer-than-expected numbers of flies. By surrounding traps with square electric fence enclosures, traps could be placed in the exhibits with the host animals and compared with an equal number of traps placed along perimeter fences. During a 21-week study, traps inside exhibits captured 5× more stable flies than traps placed along exhibit perimeters. Traps inside exhibits tended to show more fluctuations in fly populations than traps along perimeters. The increased numbers of flies captured using this technique should provide relief from this pestiferous fly and greatly improve animal health and welfare. We believe this to be the first study where traps were used to capture stable flies in exhibit yards at a zoological park. © 2017 The Authors. Zoo Biology Published by Wiley Periodicals, Inc.

Predicting the Location and Spatial Extent of Submerged Coral Reef Habitat in the Great Barrier Reef World Heritage Area, Australia

PubMed Central

Bridge, Tom; Beaman, Robin; Done, Terry; Webster, Jody

2012-01-01

Aim Coral reef communities occurring in deeper waters have received little research effort compared to their shallow-water counterparts, and even such basic information as their location and extent are currently unknown throughout most of the world. Using the Great Barrier Reef as a case study, habitat suitability modelling is used to predict the distribution of deep-water coral reef communities on the Great Barrier Reef, Australia. We test the effectiveness of a range of geophysical and environmental variables for predicting the location of deep-water coral reef communities on the Great Barrier Reef. Location Great Barrier Reef, Australia. Methods Maximum entropy modelling is used to identify the spatial extent of two broad communities of habitat-forming megabenthos phototrophs and heterotrophs. Models were generated using combinations of geophysical substrate properties derived from multibeam bathymetry and environmental data derived from Bio-ORACLE, combined with georeferenced occurrence records of mesophotic coral communities from autonomous underwater vehicle, remotely operated vehicle and SCUBA surveys. Model results are used to estimate the total amount of mesophotic coral reef habitat on the GBR. Results Our models predict extensive but previously undocumented coral communities occurring both along the continental shelf-edge of the Great Barrier Reef and also on submerged reefs inside the lagoon. Habitat suitability for phototrophs is highest on submerged reefs along the outer-shelf and the deeper flanks of emergent reefs inside the GBR lagoon, while suitability for heterotrophs is highest in the deep waters along the shelf-edge. Models using only geophysical variables consistently outperformed models incorporating environmental data for both phototrophs and heterotrophs. Main Conclusion Extensive submerged coral reef communities that are currently undocumented are likely to occur throughout the Great Barrier Reef. High-quality bathymetry data can be used to identify these reefs, which may play an important role in resilience of the GBR ecosystem to climate change. PMID:23118952

Components of a Model for Forecasting Future Status of Selected Social Indicators. Department of Education Project on Social Indicators. Technical Report No. 3.

ERIC Educational Resources Information Center

Collazo, Andres; And Others

Since a great number of variables influence future educational outcomes, forecasting possible trends is a complex task. One such model, the cross-impact matrix, has been developed. The use of this matrix in forecasting future values of social indicators of educational outcomes is described. Variables associated with educational outcomes are used…

Predicting the Spatial Distribution of Aspen Growth Potential in the Upper Great Lakes Region

Treesearch

Eric J. Gustafson; Sue M. Lietz; John L. Wright

2003-01-01

One way to increase aspen yields is to produce aspen on sites where aspen growth potential is highest. Aspen growth rates are typically predicted using site index, but this is impractical for landscape-level assessments. We tested the hypothesis that aspen growth can be predicted from site and climate variables and generated a model to map the spatial variability of...

Development of Component Mechanisms and Novel Actuation for Origami Inspired Designs

DTIC Science & Technology

2016-11-17

soft robot for the competition ‘RoboSoft Grand Challenge 2016’, and contributed greatly to SNUMAX’s winning performance. Table 1 summarizes the...gliding multimodal robot . Self-Depolyable Glider DISTRIBUTION A. Approved for public release: distribution unlimited. II. Research Performances...proposed a novel variable-diameter wheel using an origami-based soft robotics design approach. Using soft materials for a variable-diameter wheel

Modeled summer background concentration nutrients and ...

EPA Pesticide Factsheets

We used regression models to predict background concentration of four water quality indictors: total nitrogen (N), total phosphorus (P), chloride, and total suspended solids (TSS), in the mid-continent (USA) great rivers, the Upper Mississippi, the Lower Missouri, and the Ohio. From best-model linear regressions of water quality indicators with land use and other stressor variables, we determined the concentration of the indicators when the land use and stressor variables were all set to zero the y-intercept. Except for total P on the Upper Mississippi River and chloride on the Ohio River, we were able to predict background concentration from significant regression models. In every model with more than one predictor variable, the model included at least one variable representing agricultural land use and one variable representing development. Predicted background concentration of total N was the same on the Upper Mississippi and Lower Missouri rivers (350 ug l-1), which was much lower than a published eutrophication threshold and percentile-based thresholds (25th percentile of concentration at all sites in the population) but was similar to a threshold derived from the response of sestonic chlorophyll a to great river total N concentration. Background concentration of total P on the Lower Missouri (53 ug l-1) was also lower than published and percentile-based thresholds. Background TSS concentration was higher on the Lower Missouri (30 mg l-1) than the other ri

Exploring the spectral variability of the Seyfert 1.5 galaxy Markarian 530 with Suzaku

NASA Astrophysics Data System (ADS)

Ehler, H. J. S.; Gonzalez, A. G.; Gallo, L. C.

2018-05-01

A 2012 Suzaku observation of the Seyfert 1.5 galaxy Markarian 530 was analysed and found to exhibit two distinct modes of variability, which were found to be independent from one another. Firstly, the spectrum undergoes a smooth transition from a soft to a hard spectrum. Secondly, the spectrum displays more rapid variability seemingly confined to a very narrow energy band (˜1 - 3 keV). Three physical models (blurred reflection, partial covering, and soft Comptonisation) were explored to characterise the average spectrum of the observation as well as the spectral state change. All three models were found to fit the average spectrum and the spectral changes equally well. The more rapid variability appears as two cycles of a sinusoidal function, but we cannot attribute this to periodic variability. The Fe Kα band exhibits a narrow 6.4 keV emission line consistent with an origin from the distant torus. In addition, features blueward of the neutral iron line are consistent with emission from He-like and H-like iron that could be originating from the highly ionised layer of the torus, but a broad Gaussian profile at ˜6.7 keV also fits the spectrum well.

ACHP | News

Science.gov Websites

Preservation Officer, U.S. Forest Service. "This program has done a great deal to make the public more its vital role in heritage education through museum exhibits and programs, and incorporating award underscores the importance of our role in sharing the stories of Asian Pacific Americans for all

Show Me the Monet!...and Other Artists.

ERIC Educational Resources Information Center

Roman, Michele

1999-01-01

Describes a project designed to advertise art history where eighth-grade students painted the classroom door windows throughout their school recreating famous classic paintings from various artists, such as Claude Monet or Vincent van Gogh. Explains that the students learned about different artistic styles and exhibited a great deal of pride in…

Vintage Vinyl Record Design

ERIC Educational Resources Information Center

Sacco, Michael

2008-01-01

In this article, the author describes a project in which his ninth-grade art students utilized a vinyl record as an unusual medium to create a work that exhibited solid design, great creativity, and strong craftsmanship. Students presented their pieces to the class for critique, explained the process, the media, and their feelings about their…

Aztec Mexico: Discovery of Templo Mayor.

ERIC Educational Resources Information Center

Breslav, Marc

1982-01-01

Describes the Aztec archaeological artifacts shown in the American Museum of Natural History exhibit: "Aztec Mexico: Discovery of Templo Mayor." More than 100 objects, ranging from human skulls to jewelry, found in the excavation of the Great Temple of Mexico located under the center of Mexico City, were displayed. (AM)

Thermo-stability, dose effects and shelf-life of antifungal metabolite-containing supernatants produced by Xenorhabdus szentirmai

USDA-ARS?s Scientific Manuscript database

Xenorhabdus spp. produce secondary metabolites that are antifungal to protect nematode-infected cadavers from fungal colonization. In previous work, the concentrated, or cell-free metabolites of X. szentirmaii exhibited high toxicity against various fungal plant pathogens and showed great potential ...

Phylogenetic and ecological characteristics associated with thiaminase activity in Laurentian Great Lakes fishes

USGS Publications Warehouse

Riley, S.C.; Evans, A.N.

2008-01-01

Thiamine deficiency complex (TDC) causes mortality and sublethal effects in Great Lakes salmonines and results from low concentrations of egg thiamine that are thought to be caused by thiaminolytic enzymes (i.e., thiaminase) present in the diet. This complex has the potential to undermine efforts to restore lake trout Salvelinus namaycush and severely restrict salmonid production in the Great Lakes. Although thiaminase has been found in a variety of Great Lakes fishes, the ultimate source of thiaminase in Great Lakes fishes is currently unknown. We used logistic regression analysis to investigate relationships between thiaminase activity and phylogenetic or ecological characteristics of 39 Great Lakes fish species. The taxonomically more ancestral species were more likely to show thiaminase activity than the more derived species. Species that feed at lower trophic levels and occupy benthic habitats also appeared to be more likely to show thiaminase activity; these variables were correlated with taxonomy, which was the most important predictor of thiaminase activity. Further analyses of the relationship between quantitative measures of thiaminase activity and ecological characteristics of Great Lakes fish species would provide greater insight into potential sources and pathways of thiaminase in Great Lakes food webs. ?? Copyright by the American Fisheries Society 2008.

Spatial Variance in Resting fMRI Networks of Schizophrenia Patients: An Independent Vector Analysis

PubMed Central

Gopal, Shruti; Miller, Robyn L.; Michael, Andrew; Adali, Tulay; Cetin, Mustafa; Rachakonda, Srinivas; Bustillo, Juan R.; Cahill, Nathan; Baum, Stefi A.; Calhoun, Vince D.

2016-01-01

Spatial variability in resting functional MRI (fMRI) brain networks has not been well studied in schizophrenia, a disease known for both neurodevelopmental and widespread anatomic changes. Motivated by abundant evidence of neuroanatomical variability from previous studies of schizophrenia, we draw upon a relatively new approach called independent vector analysis (IVA) to assess this variability in resting fMRI networks. IVA is a blind-source separation algorithm, which segregates fMRI data into temporally coherent but spatially independent networks and has been shown to be especially good at capturing spatial variability among subjects in the extracted networks. We introduce several new ways to quantify differences in variability of IVA-derived networks between schizophrenia patients (SZs = 82) and healthy controls (HCs = 89). Voxelwise amplitude analyses showed significant group differences in the spatial maps of auditory cortex, the basal ganglia, the sensorimotor network, and visual cortex. Tests for differences (HC-SZ) in the spatial variability maps suggest, that at rest, SZs exhibit more activity within externally focused sensory and integrative network and less activity in the default mode network thought to be related to internal reflection. Additionally, tests for difference of variance between groups further emphasize that SZs exhibit greater network variability. These results, consistent with our prediction of increased spatial variability within SZs, enhance our understanding of the disease and suggest that it is not just the amplitude of connectivity that is different in schizophrenia, but also the consistency in spatial connectivity patterns across subjects. PMID:26106217

Vagal-dependent nonlinear variability in the respiratory pattern of anesthetized, spontaneously breathing rats

PubMed Central

Dhingra, R. R.; Jacono, F. J.; Fishman, M.; Loparo, K. A.; Rybak, I. A.

2011-01-01

Physiological rhythms, including respiration, exhibit endogenous variability associated with health, and deviations from this are associated with disease. Specific changes in the linear and nonlinear sources of breathing variability have not been investigated. In this study, we used information theory-based techniques, combined with surrogate data testing, to quantify and characterize the vagal-dependent nonlinear pattern variability in urethane-anesthetized, spontaneously breathing adult rats. Surrogate data sets preserved the amplitude distribution and linear correlations of the original data set, but nonlinear correlation structure in the data was removed. Differences in mutual information and sample entropy between original and surrogate data sets indicated the presence of deterministic nonlinear or stochastic non-Gaussian variability. With vagi intact (n = 11), the respiratory cycle exhibited significant nonlinear behavior in templates of points separated by time delays ranging from one sample to one cycle length. After vagotomy (n = 6), even though nonlinear variability was reduced significantly, nonlinear properties were still evident at various time delays. Nonlinear deterministic variability did not change further after subsequent bilateral microinjection of MK-801, an N-methyl-d-aspartate receptor antagonist, in the Kölliker-Fuse nuclei. Reversing the sequence (n = 5), blocking N-methyl-d-aspartate receptors bilaterally in the dorsolateral pons significantly decreased nonlinear variability in the respiratory pattern, even with the vagi intact, and subsequent vagotomy did not change nonlinear variability. Thus both vagal and dorsolateral pontine influences contribute to nonlinear respiratory pattern variability. Furthermore, breathing dynamics of the intact system are mutually dependent on vagal and pontine sources of nonlinear complexity. Understanding the structure and modulation of variability provides insight into disease effects on respiratory patterning. PMID:21527661

Spatial and Temporal Coherence of SeaWiFS Chlorophyll Concentration Anomalies in the North Atlantic Bloom (1998-2005) Examined with Giovanni

NASA Technical Reports Server (NTRS)

Acker, James G.

2006-01-01

The availability of climatological chlorophyll-a concentration data products from the SeaWiFS mission spanning the eight-year mission period allowed the creation of a climatological anomaly analysis function in Giovanni, the GES DISC Interactive Online Visualization and ANalysis Infrastructure. This study utilizes the Giovanni anomaly analysis function to examine mesoscale anomalies in the North Atlantic Ocean during the springtime North Atlantic Bloom. This examination indicates that areas exhibiting positive anomalies and areas exhibiting negative anomalies are coherent over significant spatial scales, with relatively abrupt boundaries between areas with positive and negative anomalies. Year-to-year variability in anomaly "intensity" can be caused by either variability in the temporal occurrence of the bloom peak or by variability in the peak chlorophyll concentration in a particular area. The study will also discuss the feasibility of combining chlorophyll anomaly analysis with other data types.

Wind, Circulation, and Topographic Effects on Alongshore Phytoplankton Variability in the California Current

NASA Astrophysics Data System (ADS)

Fiechter, Jerome; Edwards, Christopher A.; Moore, Andrew M.

2018-04-01

A physical-biogeochemical model is used to produce a retrospective analysis at 3-km resolution of alongshore phytoplankton variability in the California Current during 1988-2010. The simulation benefits from downscaling a regional circulation reanalysis, which provides improved physical ocean state estimates in the high-resolution domain. The emerging pattern is one of local upwelling intensification in response to increased alongshore wind stress in the lee of capes, modulated by alongshore meanders in the geostrophic circulation. While stronger upwelling occurs near most major topographic features, substantial increases in phytoplankton biomass only ensue where local circulation patterns are conducive to on-shelf retention of upwelled nutrients. Locations of peak nutrient delivery and chlorophyll accumulation also exhibit interannual variability and trends noticeably larger than the surrounding shelf regions, thereby suggesting that long-term planktonic ecosystem response in the California Current exhibits a significant local scale (O(100 km)) alongshore component.

The eclipsing AM Herculis variable H1907 + 690

NASA Technical Reports Server (NTRS)

Remillard, R. A.; Silber, A.; Stroozas, B. A.; Tapia, S.

1991-01-01

The discovery is reported of an eclipsing cataclysmic variable that exhibits up to 10 percent circular polarization at optical wavelengths, securing its classification as an AM Herculis type binary. The object, H1907 + 609, was located with the guidance of X-ray positions from the HEAO 1 survey. Optical CCD photometry exhibits deep eclipses, from which is derived a precise orbital period of 1.743750 hr. The eclipse duration suggests an inclination angle about 80 deg for a main-sequence secondary star. The optical flux has been persistently faint during observations spanning 1987-1990, while the X-ray measurements suggest long-term X-ray variability. The polarization and photometric light curves can be interpreted with a geometric model in which most of the accretion is directed toward a single magnetic pole, with an accretion spot displaced about 17 deg in longitude from the projection of the secondary star on the white dwarf surface.

The chewing lice (Phthiraptera: Ischnocera, Amblycera) of the great cormorant (Phalacrocorax carbo).

PubMed

Leitinger, Jan Phillip; Richter, Stefan

2018-08-01

The Great Cormorant is a widespread bird species with almost worldwide distribution. Accordingly, its general biology has been investigated thoroughly. Less well known, however, are the chewing lice that live inside the plumage of this diving bird. We examined the two known species of Great Cormorant chewing lice, Eidmanniella pellucida (Rudow, 1869) (Amblycera: Menoponidae) and Pectinopygus gyricornis (Denny, 1842) (Ischnocera: Philopteridae). Taking advantage of the autofluorescence of the cuticle, confocal laser scanning microscopy (CLSM) was used to explore the external morphology of all developmental stages of P. gyricornis. Morphometric analyses revealed a standard increase in body size from first larval instar to the adult. In addition, all instars exhibited increasing body segment differentiation, especially in the abdomen and the head. A total of 277 individuals of Pectinopygus gyricornis and 2 individuals of Eidmanniella pellucida were collected from eleven Great Cormorants from Mecklenburg-Western Pomerania, Germany, in 2015. Copyright © 2018 Elsevier B.V. All rights reserved.

Bone indicators of grasping hands in lizards

PubMed Central

2016-01-01

Grasping is one of a few adaptive mechanisms that, in conjunction with clinging, hooking, arm swinging, adhering, and flying, allowed for incursion into the arboreal eco-space. Little research has been done that addresses grasping as an enhanced manual ability in non-mammalian tetrapods, with the exception of studies comparing the anatomy of muscle and tendon structure. Previous studies showed that grasping abilities allow exploitation for narrow branch habitats and that this adaptation has clear osteological consequences. The objective of this work is to ascertain the existence of morphometric descriptors in the hand skeleton of lizards related to grasping functionality. A morphological matrix was constructed using 51 morphometric variables in 278 specimens, from 24 genera and 13 families of Squamata. To reduce the dimensions of the dataset and to organize the original variables into a simpler system, three PCAs (Principal Component Analyses) were performed using the subsets of (1) carpal variables, (2) metacarpal variables, and (3) phalanges variables. The variables that demonstrated the most significant contributions to the construction of the PCA synthetic variables were then used in subsequent analyses. To explore which morphological variables better explain the variations in the functional setting, we ran Generalized Linear Models for the three different sets. This method allows us to model the morphology that enables a particular functional trait. Grasping was considered the only response variable, taking the value of 0 or 1, while the original variables retained by the PCAs were considered predictor variables. Our analyses yielded six variables associated with grasping abilities: two belong to the carpal bones, two belong to the metacarpals and two belong to the phalanges. Grasping in lizards can be performed with hands exhibiting at least two different independently originated combinations of bones. The first is a combination of a highly elongated centrale bone, reduced palmar sesamoid, divergence angles above 90°, and slender metacarpal V and phalanges, such as exhibited by Anolis sp. and Tropidurus sp. The second includes an elongated centrale bone, lack of a palmar sesamoid, divergence angles above 90°, and narrow metacarpal V and phalanges, as exhibited by geckos. Our data suggest that the morphological distinction between graspers and non-graspers is demonstrating the existence of ranges along the morphological continuum within which a new ability is generated. Our results support the hypothesis of the nested origin of grasping abilities within arboreality. Thus, the manifestation of grasping abilities as a response to locomotive selective pressure in the context of narrow-branch eco-spaces could also enable other grasping-dependent biological roles, such as prey handling. PMID:27168987

Annotation: Early Intervention and Prevention of Self-Injurious Behaviour Exhibited by Young Children with Developmental Disabilities

ERIC Educational Resources Information Center

Richman, D. M.

2008-01-01

The ontogeny of self-injurious behaviour exhibited by young children with developmental delays or disabilities is due to a complex interaction between neurobiological and environmental variables. In this manuscript, the literature on emerging self-injury in the developmental disability population is reviewed with a focus on an operant conceptual…

Mathematical model for production of an industry focusing on worker status

NASA Astrophysics Data System (ADS)

Visalakshi, V.; kiran kumari, Sheshma

2018-04-01

Productivity improvement is posing a great challenge for industry everyday because of the difficulties in keeping track and priorising the variables that have significant impact on the productivity. The variation in production depends on the linguistic variables such as worker commitment, worker motivation and worker skills. Since the variables are linguistic we try to propose a model which gives an appropriate production of an industry. Fuzzy models aids the relationship between the factors and status. The model will support the industry to focus on the mentality of worker to increase the production.

Gorlin and goltz syndrome: a case report with surgical review.

PubMed

Namdeoraoji Bahadure, Rakesh; Surendraji Jain, Eesha; P Badole, Gautam

2013-05-01

Gorlin and Goltz syndrome are a very complex syndrome and a multisystemic process that is characterized by the presence of multiple pigmented basocellular carcinomas, keratocysts in the jaws, palmar and/or plantar pits and calcification of the falx cerebri. Along with these major features a great number minor features have also been described which involves numerous skeletical, dermatology related, neurological, ophthalmological and reproductive anomalies. It exhibits high penetrance and variable expressivity. Presented here is the case of Gorlin-Goltz in a 12 years old male patient which was diagnosed through its oral and maxillofacial manifestations. Treatment of odontogenic keratocyst was done by enucleation without primary suturing. Iodoform dressing was kept to enhance the healing and to reduce the recurrence of the lesion. It is important to provide the early diagnosis for detection of clinical and radiological manifestations in young patients and for provision of advice concerning preventive treatment like protection of the skin from the sunlight and genetic sensitivity testing so that possible complications associated with this syndrome can be prevented. How to cite this article: Bahadure RN, Jain ES, Badole GP. Gorlin and Goltz Syndrome: A Case Report with Surgical Review. Int J Clin Pediatr Dent 2013;6(2):104-108.

Gorlin and Goltz Syndrome: A Case Report with Surgical Review

PubMed Central

Surendraji Jain, Eesha; P Badole, Gautam

2013-01-01

ABSTRACT Gorlin and Goltz syndrome are a very complex syndrome and a multisystemic process that is characterized by the presence of multiple pigmented basocellular carcinomas, keratocysts in the jaws, palmar and/or plantar pits and calcification of the falx cerebri. Along with these major features a great number minor features have also been described which involves numerous skeletical, dermatology related, neurological, ophthalmological and reproductive anomalies. It exhibits high penetrance and variable expressivity. Presented here is the case of Gorlin-Goltz in a 12 years old male patient which was diagnosed through its oral and maxillofacial manifestations. Treatment of odontogenic keratocyst was done by enucleation without primary suturing. Iodoform dressing was kept to enhance the healing and to reduce the recurrence of the lesion. It is important to provide the early diagnosis for detection of clinical and radiological manifestations in young patients and for provision of advice concerning preventive treatment like protection of the skin from the sunlight and genetic sensitivity testing so that possible complications associated with this syndrome can be prevented. How to cite this article: Bahadure RN, Jain ES, Badole GP. Gorlin and Goltz Syndrome: A Case Report with Surgical Review. Int J Clin Pediatr Dent 2013;6(2):104-108. PMID:25206202

Gut Microbiota and Host Reaction in Liver Diseases

PubMed Central

Fukui, Hiroshi

2015-01-01

Although alcohol feeding produces evident intestinal microbial changes in animals, only some alcoholics show evident intestinal dysbiosis, a decrease in Bacteroidetes and an increase in Proteobacteria. Gut dysbiosis is related to intestinal hyperpermeability and endotoxemia in alcoholic patients. Alcoholics further exhibit reduced numbers of the beneficial Lactobacillus and Bifidobacterium. Large amounts of endotoxins translocated from the gut strongly activate Toll-like receptor 4 in the liver and play an important role in the progression of alcoholic liver disease (ALD), especially in severe alcoholic liver injury. Gut microbiota and bacterial endotoxins are further involved in some of the mechanisms of nonalcoholic fatty liver disease (NAFLD) and its progression to nonalcoholic steatohepatitis (NASH). There is experimental evidence that a high-fat diet causes characteristic dysbiosis of NAFLD, with a decrease in Bacteroidetes and increases in Firmicutes and Proteobacteria, and gut dysbiosis itself can induce hepatic steatosis and metabolic syndrome. Clinical data support the above dysbiosis, but the details are variable. Intestinal dysbiosis and endotoxemia greatly affect the cirrhotics in relation to major complications and prognosis. Metagenomic approaches to dysbiosis may be promising for the analysis of deranged host metabolism in NASH and cirrhosis. Management of dysbiosis may become a cornerstone for the future treatment of liver diseases. PMID:27682116

Protein Hydrolysates and Biopeptides: Production, Biological Activities, and Applications in Foods and Health Benefits. A Review.

PubMed

Nasri, M

In recent years, a great deal of interest has been expressed regarding the production, characterization, and applications of protein hydrolysates and food-derived biopeptides due to their numerous beneficial health effects. In this regard, research is mainly focused on investigating the therapeutic potential of these natural compounds. Based on their amino acids composition, sequences, hydrophobicity, and length, peptides released from food proteins, beyond their nutritional properties, can exhibit various biological activities including antihypertensive, antioxidative, antithrombotic, hypoglycemic, hypocholesterolemic, and antibacterial activities among others. Protein hydrolysates are essentially produced by enzymatic hydrolysis of whole protein sources by appropriate proteolytic enzymes under controlled conditions, followed by posthydrolysis processing to isolate desired and potent bioactive peptides from a complex mixture of active and inactive peptides. Therefore, because of their human health potential and safety profiles, protein hydrolysates and biopeptides may be used as ingredients in functional foods and pharmaceuticals to improve human health and prevent diseases. In this review, we have focused on the major variables influencing the enzymatic process of protein hydrolysates production. The biological properties of protein hydrolysates will be described as well as their applications in foods and health benefits. © 2017 Elsevier Inc. All rights reserved.

Composition spread studies of Nd1-xLaxNiO3 combinatorial thin films

NASA Astrophysics Data System (ADS)

Suchoski, Richard; Jin, Kui; Yasui, Shintaro; Greene, Richard; Takeuchi, Ichiro

2013-03-01

Rare earth nickelates have attracted a great deal of attention in recent years due to a host of interesting features, one being a transition from paramagnetic metal to antiferromagnetic insulator through distortions from the ideal perovskite unit cell. This metal-to-insulator transition (MIT) can be manipulated by modifying variables such as temperature, rare earth ion size, oxygen content, or stress from lattice-mismatched epitaxial thin film growth. Research on this family has been extensive, though there still exists an absence of thin film studies focusing on intermediate compositions. We have fabricated epitaxial thin film composition spreads of Nd1-xLaxNiO3 grown via combinatorial PLD to investigate these transitional compositions. While our films exhibit a smooth composition progression, we observe a composition threshold where orthorhombic NdNiO3 transforms to rhombohedral LaNiO3, correlating with disappearance of the MIT, and displays a non-Vegard evolution of the film's in-plane lattice constant in HRXRD and Raman scattering data of the A1g rotational mode. This work was performed at the Center for Nanophysics and Advanced Materials (CNAM) at UMD, and supported by AFO SR MURI Grant #FA95500910603.

Effect Of Gravity On Porous Tricalcium Phosphate And Nonstoichiometric Titanium Carbide Produced Via Combustion Synthesis

NASA Technical Reports Server (NTRS)

Castillo, M.; Moore, J. J.; Schowengerdt, F. D.; Ayers, R. A.

2003-01-01

Novel processing techniques, such as self-propagating high temperature synthesis (SHS), have the capability to rapidly produce advanced porous materials that are difficult to fabricate by other methods. This processing technique is also capable of near net shape synthesis, while variable gravity allows the manipulation of the structure and composition of the material. The creation of porous tricalcium phosphate (TCP) is advantageous in the biomaterials field, since it is both a biocompatible material and an osteoconductive material. Porous tricalcium phosphate produced via SHS is an excellent candidate for bone scaffold material in the bone regeneration process. The porosity allows for great vascularization and ingrowth of tissue. Titanium Carbide is a nonstoichiometric biocompatible material that can be incorporated into a TiC-Ti composite system using combustion synthesis. The TiC-Ti composite exhibits a wide range of mechanical and chemical properties. Both of these material systems (TCP and TiC-Ti) can be used to advantage in designing novel bone replacement materials. Gravity plays an important role in both the pore structure and the chemical uniformity of these composite systems and offers considerable potential in advanced bone engineering.

Short-term and long-term outcome of athletic closed head injuries.

PubMed

Webbe, Frank M; Barth, Jeffrey T

2003-07-01

The continued development of the sport environment as a laboratory for clinical investigation of mild head injury has greatly advanced the use of neuropsychological assessment in evaluating brain-injured athletes, and tracking their symptoms and recovery in an objective manner. The use of neurocognitive baseline measures has become critical in determining whether a brain-injured athlete has recovered function sufficiently to return to play. The rapid growth of computerized and web-based neurocognitive assessment measures provides an efficient, valid technology to put such testing within the reach of most institutions and organizations that field sport teams. Moreover, the knowledge of the recovery curve following mild head injury in the sport environment can be generalized to the management of MTBI in general clinical environments where baseline measures are unlikely. What we know today is that sideline assessments of severity are not predictive of which athletes will show the most typical 5- to 10-day recovery period and which will report persistent PCS complaints and exhibit impaired neurocognitive performance for an extended time. The research on mechanisms of brain injury in MTBI suggests that unpredictable, diffuse white-matter damage may control much of the variability in functional impairments and recovery duration.

Analyzing endocrine system conservation and evolution.

PubMed

Bonett, Ronald M

2016-08-01

Analyzing variation in rates of evolution can provide important insights into the factors that constrain trait evolution, as well as those that promote diversification. Metazoan endocrine systems exhibit apparent variation in evolutionary rates of their constituent components at multiple levels, yet relatively few studies have quantified these patterns and analyzed them in a phylogenetic context. This may be in part due to historical and current data limitations for many endocrine components and taxonomic groups. However, recent technological advancements such as high-throughput sequencing provide the opportunity to collect large-scale comparative data sets for even non-model species. Such ventures will produce a fertile data landscape for evolutionary analyses of nucleic acid and amino acid based endocrine components. Here I summarize evolutionary rate analyses that can be applied to categorical and continuous endocrine traits, and also those for nucleic acid and protein-based components. I emphasize analyses that could be used to test whether other variables (e.g., ecology, ontogenetic timing of expression, etc.) are related to patterns of rate variation and endocrine component diversification. The application of phylogenetic-based rate analyses to comparative endocrine data will greatly enhance our understanding of the factors that have shaped endocrine system evolution. Copyright © 2016 Elsevier Inc. All rights reserved.

The application of microtextural and heavy mineral analysis to discriminate between storm and tsunami deposits

USGS Publications Warehouse

Costa, Pedro J.M.; Gelfenbaum, Guy R.; Dawson, Sue; La selle, Seanpaul; Milne, F; Cascalho, J.; Ponte Lira, C.; Andrade, C.; Freitas, M. C.; Jaffe, Bruce E.

2017-01-01

Recent work has applied microtextural and heavy mineral analyses to sandy storm and tsunami deposits from Portugal, Scotland, Indonesia and the USA. We looked at the interpretation of microtextural imagery (scanning electron microscopy) of quartz grains and heavy mineral compositions. We consider inundation events of different chronologies and sources (the AD 1755 Lisbon and 2004 Indian Ocean tsunamis, the Great Storm of 11 January 2005 in Scotland, and Hurricane Sandy in 2012) that affected contrasting coastal and hinterland settings with different regional oceanographic conditions. Storm and tsunami deposits were examined along with potential source sediments (alluvial, beach, dune and nearshore sediments) to determine provenance.Results suggest that tsunami deposits typically exhibit a significant spatial variation in grain sizes, microtextures and heavy minerals. Storm deposits show less variability, especially in vertical profiles. Tsunami and storm quartz grains had more percussion marks and fresh surfaces compared to potential source material. Moreover, in the studied cases, tsunami samples had fewer fresh surfaces than storm deposits.Heavy mineral assemblages are typically site-specific. The concentration of heavy minerals decreases upwards in tsunamigenic units, whereas storm sediments show cyclic concentrations of heavy minerals, reflected in the laminations observed macroscopically in the deposits.

A balanced memory network.

PubMed

Roudi, Yasser; Latham, Peter E

2007-09-01

A fundamental problem in neuroscience is understanding how working memory--the ability to store information at intermediate timescales, like tens of seconds--is implemented in realistic neuronal networks. The most likely candidate mechanism is the attractor network, and a great deal of effort has gone toward investigating it theoretically. Yet, despite almost a quarter century of intense work, attractor networks are not fully understood. In particular, there are still two unanswered questions. First, how is it that attractor networks exhibit irregular firing, as is observed experimentally during working memory tasks? And second, how many memories can be stored under biologically realistic conditions? Here we answer both questions by studying an attractor neural network in which inhibition and excitation balance each other. Using mean-field analysis, we derive a three-variable description of attractor networks. From this description it follows that irregular firing can exist only if the number of neurons involved in a memory is large. The same mean-field analysis also shows that the number of memories that can be stored in a network scales with the number of excitatory connections, a result that has been suggested for simple models but never shown for realistic ones. Both of these predictions are verified using simulations with large networks of spiking neurons.

Electrochemical sensor for multiplex screening of genetically modified DNA: identification of biotech crops by logic-based biomolecular analysis.

PubMed

Liao, Wei-Ching; Chuang, Min-Chieh; Ho, Ja-An Annie

2013-12-15

Genetically modified (GM) technique, one of the modern biomolecular engineering technologies, has been deemed as profitable strategy to fight against global starvation. Yet rapid and reliable analytical method is deficient to evaluate the quality and potential risk of such resulting GM products. We herein present a biomolecular analytical system constructed with distinct biochemical activities to expedite the computational detection of genetically modified organisms (GMOs). The computational mechanism provides an alternative to the complex procedures commonly involved in the screening of GMOs. Given that the bioanalytical system is capable of processing promoter, coding and species genes, affirmative interpretations succeed to identify specified GM event in terms of both electrochemical and optical fashions. The biomolecular computational assay exhibits detection capability of genetically modified DNA below sub-nanomolar level and is found interference-free by abundant coexistence of non-GM DNA. This bioanalytical system, furthermore, sophisticates in array fashion operating multiplex screening against variable GM events. Such a biomolecular computational assay and biosensor holds great promise for rapid, cost-effective, and high-fidelity screening of GMO. Copyright © 2013 Elsevier B.V. All rights reserved.

Troubleshooting RSIG

EPA Pesticide Factsheets

Remote Sensing Information Gateway, a tool that allows scientists, researchers and decision makers to access a variety of multi-terabyte, environmental datasets and to subset the data and obtain only needed variables, greatly improving the download time.

Decadal-to-centennial-scale climate variability: Insights into the rise and fall of the Great Salt Lake

NASA Technical Reports Server (NTRS)

Mann, Michael E.; Lall, Upmanu; Saltzman, Barry

1995-01-01

We demonstrate connections between decadal and secular global climatic variations, and historical variations in the volume of the Great Salt Lake. The decadal variations correspond to a low-frequency shifting of storm tracks which influence winter precipitation and explain nearly 18% of the interannual and longer-term variance in the record of monthly volume change. The secular trend accounts for a more modest approximately 1.5% of the variance.

Immortal, telomerase-negative cell lines derived from a Li-Fraumeni syndrome patient exhibit telomere length variability and chromosomal and minisatellite instabilities.

PubMed

Tsutsui, Takeki; Kumakura, Shin-Ichi; Tamura, Yukiko; Tsutsui, Takeo W; Sekiguchi, Mizuki; Higuchi, Tokihiro; Barrett, J Carl

2003-05-01

Five immortal cell lines derived from a Li-Fraumeni syndrome patient (MDAH 087) with a germline mutant p53 allele were characterized with respect to telomere length and genomic instability. The remaining wild-type p53 allele is lost in the cell lines. Telomerase activity was undetectable in all immortal cell lines. Five subclones of each cell line and five re-subclones of each of the subclones also showed undetectable telomerase activity. All five immortal cell lines exhibited variability in the mean length of terminal restriction fragments (TRFs). Subclones of each cell line, and re-subclones of the subclones also showed TRF variability, indicating that the variability is owing to clonal heterogeneity. Chromosome aberrations were observed at high frequencies in these cell lines including the subclones and re-subclones, and the principal types of aberrations were breaks, double minute chromosomes and dicentric chromosomes. In addition, minisatellite instability detected by DNA fingerprints was observed in the immortal cell lines. However, all of the cell lines were negative for microsatellite instability. As minisatellite sequences are considered recombinogenic in mammalian cells, these results suggest that recombination rates can be increased in these cell lines. Tumor-derived human cell lines, HT1080 cells and HeLa cells that also lack p53 function, exhibited little genomic instability involving chromosomal and minisatellite instabilities, indicating that chromosomal and minisatellite instabilities observed in the immortal cell lines lacking telomerase activity could not result from loss of p53 function.

Spatial, Temporal, and Matrix Variability of Clostridium botulinum Type E Toxin Gene Distribution at Great Lakes Beaches

PubMed Central

Oster, Ryan J.; Haack, Sheridan K.; Fogarty, Lisa R.; Tucker, Taaja R.; Riley, Stephen C.

2015-01-01

Clostridium botulinum type E toxin is responsible for extensive mortality of birds and fish in the Great Lakes. The C. botulinum bontE gene that produces the type E toxin was amplified with quantitative PCR from 150 sloughed algal samples (primarily Cladophora species) collected during summer 2012 from 10 Great Lakes beaches in five states; concurrently, 74 sediment and 37 water samples from four sites were also analyzed. The bontE gene concentration in algae was significantly higher than in water and sediment (P < 0.05), suggesting that algal mats provide a better microenvironment for C. botulinum. The bontE gene was detected most frequently in algae at Jeorse Park and Portage Lake Front beaches (Lake Michigan) and Bay City State Recreation Area beach on Saginaw Bay (Lake Huron), where 77, 100, and 83% of these algal samples contained the bontE gene, respectively. The highest concentration of bontE was detected at Bay City (1.98 × 105 gene copies/ml of algae or 5.21 × 106 g [dry weight]). This study revealed that the bontE gene is abundant in the Great Lakes but that it has spatial, temporal, and matrix variability. Further, embayed beaches, low wave height, low wind velocity, and greater average water temperature enhance the bontE occurrence. PMID:25888178

Biomechanical deviations during level walking associated with knee osteoarthritis: a systematic review and meta-analysis.

PubMed

Mills, Kathryn; Hunt, Michael A; Ferber, Reed

2013-10-01

To identify which gait deviations are consistently associated with knee osteoarthritis (KOA) and how these are influenced by disease severity, the involved compartment, and sex. Five electronic databases and reference lists of publications were searched. Cross-sectional, observational studies comparing temporospatial variables, joint kinematics, and joint moments between individuals with KOA and healthy controls or between KOA subgroups were considered for review. Only publications scoring ≥50% on a modified methodology quality index were included. Because of the number of gait deviations examined, only biomechanical variables reported by ≥4 publications were further analyzed. Where possible, a meta-analysis was performed using effect sizes (ES) calculated from discrete variables. In total, 41 publications examining 20 variables were included. The majority of consistent gait deviations associated with KOA were exhibited by those with severe disease in the temporospatial domain. Individuals with severe KOA exhibited greater stride duration than controls (ES 1.35 [95% confidence interval (95% CI) 1.03, 1.67]) and a decrease in cadence (ES -0.75 [95% CI -1.12, -0.39]) compared with controls. The evidence for kinematic and joint moment change was primarily limited or conflicting. There was a lack of evidence for alterations in the external knee adduction moment. Individuals with KOA exhibit a range of gait deviations compared with controls. Despite its common usage in KOA gait studies, we did not find consistent evidence that knee adduction moment differs between those with and without KOA or between disease severity levels. Further research examining the reasons for a lack of difference in many gait variables in those with knee OA is needed. Copyright © 2013 by the American College of Rheumatology.

The match-to-match variation of match-running in elite female soccer.

PubMed

Trewin, Joshua; Meylan, César; Varley, Matthew C; Cronin, John

2018-02-01

The purpose of this study was to examine the match-to-match variation of match-running in elite female soccer players utilising GPS, using full-match and rolling period analyses. Longitudinal study. Elite female soccer players (n=45) from the same national team were observed during 55 international fixtures across 5 years (2012-2016). Data was analysed using a custom built MS Excel spreadsheet as full-matches and using a rolling 5-min analysis period, for all players who played 90-min matches (files=172). Variation was examined using co-efficient of variation and 90% confidence limits, calculated following log transformation. Total distance per minute exhibited the smallest variation when both the full-match and peak 5-min running periods were examined (CV=6.8-7.2%). Sprint-efforts were the most variable during a full-match (CV=53%), whilst high-speed running per minute exhibited the greatest variation in the post-peak 5-min period (CV=143%). Peak running periods were observed as slightly more variable than full-match analyses, with the post-peak period very-highly variable. Variability of accelerations (CV=17%) and Player Load (CV=14%) was lower than that of high-speed actions. Positional differences were also present, with centre backs exhibiting the greatest variation in high-speed movements (CV=41-65%). Practitioners and researchers should account for within player variability when examining match performances. Identification of peak running periods should be used to assist worst case scenarios. Whilst micro-sensor technology should be further examined as to its viable use within match-analyses. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Contaminants of emerging concern in tributaries to the Laurentian Great Lakes: II. Biological consequences of exposure

PubMed Central

Brigham, Mark E.; Choy, Steven J.; Moore, Jeremy N.; Banda, Jo A.; Gefell, Daniel J.; Minarik, Thomas A.

2017-01-01

The Laurentian Great Lakes contain one fifth of the world’s surface freshwater and have been impacted by human activity since the Industrial Revolution. In addition to legacy contaminants, nitrification and invasive species, this aquatic ecosystem is also the recipient of Contaminants of Emerging Concern (CECs) with poorly understood biological consequences. In the current study, we documented the presence, concentrations, and biological effects of CECs across 27 field sites in six Great Lakes tributaries by examining over 2250 resident and caged sunfish (Lepomis ssp.) for a variety of morphological and physiological endpoints and related these results to CEC occurrence. CEC were ubiquitous across studies sites and their presence and concentrations in water and sediment were highest in effluent dominated rivers and downstream of municipal wastewater treatment plant discharges. However, even putative upstream reference sites were not free of CEC presence and fish at these sites exhibited biological effects consistent with CEC exposure. Only the Fox River exhibited consistent adverse biological effects, including increased relative liver size, greater prominence of hepatocyte vacuoles and increased plasma glucose concentrations. Canonical Redundancy Analysis revealed consistent patterns of biological consequences of CEC exposure across all six tributaries. Increasing plasma glucose concentrations, likely as a result of pollutant-induced metabolic stress, were associated with increased relative liver size and greater prominence of hepatocyte vacuoles. These indicators of pollutant exposure were inversely correlated with indicators of reproductive potential including smaller gonad size and less mature gametes. The current study highlights the need for greater integration of chemical and biological studies and suggests that CECs in the Laurentian Great Lakes Basin may adversely affect the reproductive potential of exposed fish populations. PMID:28953953

Contaminants of emerging concern in tributaries to the Laurentian Great Lakes: II. Biological consequences of exposure.

PubMed

Thomas, Linnea M; Jorgenson, Zachary G; Brigham, Mark E; Choy, Steven J; Moore, Jeremy N; Banda, Jo A; Gefell, Daniel J; Minarik, Thomas A; Schoenfuss, Heiko L

2017-01-01

The Laurentian Great Lakes contain one fifth of the world's surface freshwater and have been impacted by human activity since the Industrial Revolution. In addition to legacy contaminants, nitrification and invasive species, this aquatic ecosystem is also the recipient of Contaminants of Emerging Concern (CECs) with poorly understood biological consequences. In the current study, we documented the presence, concentrations, and biological effects of CECs across 27 field sites in six Great Lakes tributaries by examining over 2250 resident and caged sunfish (Lepomis ssp.) for a variety of morphological and physiological endpoints and related these results to CEC occurrence. CEC were ubiquitous across studies sites and their presence and concentrations in water and sediment were highest in effluent dominated rivers and downstream of municipal wastewater treatment plant discharges. However, even putative upstream reference sites were not free of CEC presence and fish at these sites exhibited biological effects consistent with CEC exposure. Only the Fox River exhibited consistent adverse biological effects, including increased relative liver size, greater prominence of hepatocyte vacuoles and increased plasma glucose concentrations. Canonical Redundancy Analysis revealed consistent patterns of biological consequences of CEC exposure across all six tributaries. Increasing plasma glucose concentrations, likely as a result of pollutant-induced metabolic stress, were associated with increased relative liver size and greater prominence of hepatocyte vacuoles. These indicators of pollutant exposure were inversely correlated with indicators of reproductive potential including smaller gonad size and less mature gametes. The current study highlights the need for greater integration of chemical and biological studies and suggests that CECs in the Laurentian Great Lakes Basin may adversely affect the reproductive potential of exposed fish populations.

Contaminants of emerging concern in tributaries to the Laurentian Great Lakes: II. Biological consequences of exposure

USGS Publications Warehouse

Thomas, Linnea M.; Jorgenson, Zachary G.; Brigham, Mark E.; Choy, Steven J.; Moore, Jeremy N.; Banda, Jo A.; Gefell, D.J.; Minarik, Thomas A.; Schoenfuss, Heiko L.

2017-01-01

The Laurentian Great Lakes contain one fifth of the world’s surface freshwater and have been impacted by human activity since the Industrial Revolution. In addition to legacy contaminants, nitrification and invasive species, this aquatic ecosystem is also the recipient of Contaminants of Emerging Concern (CECs) with poorly understood biological consequences. In the current study, we documented the presence, concentrations, and biological effects of CECs across 27 field sites in six Great Lakes tributaries by examining over 2250 resident and caged sunfish (Lepomis ssp.) for a variety of morphological and physiological endpoints and related these results to CEC occurrence. CEC were ubiquitous across studies sites and their presence and concentrations in water and sediment were highest in effluent dominated rivers and downstream of municipal wastewater treatment plant discharges. However, even putative upstream reference sites were not free of CEC presence and fish at these sites exhibited biological effects consistent with CEC exposure. Only the Fox River exhibited consistent adverse biological effects, including increased relative liver size, greater prominence of hepatocyte vacuoles and increased plasma glucose concentrations. Canonical Redundancy Analysis revealed consistent patterns of biological consequences of CEC exposure across all six tributaries. Increasing plasma glucose concentrations, likely as a result of pollutant-induced metabolic stress, were associated with increased relative liver size and greater prominence of hepatocyte vacuoles. These indicators of pollutant exposure were inversely correlated with indicators of reproductive potential including smaller gonad size and less mature gametes. The current study highlights the need for greater integration of chemical and biological studies and suggests that CECs in the Laurentian Great Lakes Basin may adversely affect the reproductive potential of exposed fish populations.

Bi-functional fusion enzyme EG-M-Xyn displaying endoglucanase and xylanase activities and its utility in improving lignocellulose degradation.

PubMed

Chen, Chin-Chung; Gao, Guo-Jhan; Kao, Ai-Ling; Tsai, Zheng-Chia

2018-05-01

In this study, the gene fusion of endoglucanase (EG, one of cellulases) from Teleogryllus emma and xylanase (Xyn, one of hemicellulases) from Thermomyces lanuginosus was constructed to generate a fusion enzyme (EG-M-Xyn). Through the expression and purification by ultrafiltration and size-exclusion chromatography, the purified EG-M-Xyn had a molecular weight of 75.5 kDa and exhibited the specific activity of CMCase and xylanase as 306.8 U/mg and 1227.3 U/mg, respectively. The K m values (CMC and beechwood xylan) were 6.8 and 60.6 mg mL -1 while catalytic efficiency (k cat /K m ) values of CMCase and xylanase were 3280 and 38,797 min -1  mg -1  mL, respectively. EG-M-Xyn exerted great properties for its great potential in improving the enzymatic hydrolysis of lignocellulosics to produce fermentable sugars. First, EG-M-Xyn showed mild reaction pH and temperature of 5.5 and 50 °C, respectively. Secondly, EG-M-Xyn exhibited great heat tolerance of T 1/2 values of 173 (CMCase) and 693 min (xylanase). Lastly and most importantly, application of EG-M-Xyn in combination with Ctec2 (commercial enzyme) in the saccharification led to a 10-20% net increase in fermentable sugars liberated from pretreated rice straw in comparison to the Ctec2 alone group. In conclusion, EG-M-Xyn had great potential in generating fermentable sugars from renewable agro-residues for biofuel and fine chemical industry. Copyright © 2017 Elsevier B.V. All rights reserved.

Morphologic and chemical composition of particulate matter in motorcycle engine exhaust.

PubMed

Chernyshev, V V; Zakharenko, A M; Ugay, S M; Hien, T T; Hai, L H; Kholodov, A S; Burykina, T I; Stratidakis, A K; Mezhuev, Ya O; Tsatsakis, A M; Golokhvast, K S

2018-01-01

Despite the fact that environmental pollution due to motorcycle exhaust gases reports a great increase, motorcycle production exhibits a great increase through the last years. Countries of Asia and Africa are reported to be the major regions where two-wheeled vehicles are a major transportation mode, with tens of millions of units sold per year. Motorcycle exhaust particles are considered to be the major contributor to environmental pollution due to their airborne dispersion, containing great amount of polycyclic aromatic hydrocarbons (PAHs). This study aims at reporting an objective analysis of the main sources of the ambient air pollution as also particle size distribution and chemical composition analysis of particulate matter originated from the exhausts of two-wheeled vehicles used in the territory of Vladivostok, Russia. Various types of two-wheeled vehicles were examined (motorcycles, ATVs, scooters and wet bikes) using different types of engine and fuel system. Experimental results showed that there was no clear relation to the particle size distribution with the engine displacement of motorcycle and the number of strokes and the fuel system. Instead, there were reported two clear assumptions. The first one is that regarding to the motorcycle brand, a few samples did not exhibit a great percentage of PM 10 fraction. The second one is that more modern vehicles, that have a harmful gas afterburning system, are usually the source of an increased percentage of PM 10 emitted particles. At last, it should be mentioned that the laser particle size analysis method is capable of determining the particle sizes after their agglomeration whereas the optical morphometry method allows to determine the real particle size of emissions. In conclusion, it can be pointed out that the agglomeration of particles can lead to the reduction in the toxicity of particles emissions originated from two wheeled-vehicles.

The Use of Structural Behavioral Assessment to Develop Interventions for Secondary Students Exhibiting Challenging Behaviors

ERIC Educational Resources Information Center

Losinski, Mickey; Maag, John W.; Katsiyannis, Antonis; Ryan, Joseph B.

2015-01-01

Structural behavioral assessment (SBA) involves a series of heuristic approaches similar to those used with functional behavioral assessment (FBA). It involves assessing contextual variables that precede the occurrence of a behavior. These variables have also been termed antecedents, setting events, or establishing operations. Once these variables…

A Better Lemon Squeezer? Maximum-Likelihood Regression with Beta-Distributed Dependent Variables

ERIC Educational Resources Information Center

Smithson, Michael; Verkuilen, Jay

2006-01-01

Uncorrectable skew and heteroscedasticity are among the "lemons" of psychological data, yet many important variables naturally exhibit these properties. For scales with a lower and upper bound, a suitable candidate for models is the beta distribution, which is very flexible and models skew quite well. The authors present…

Vegetation and environmental controls on soil respiration in a pinon-juniper woodland

Treesearch

Sandra A. White

2008-01-01

Soil respiration (RS) responds to changes in plant and microbial activity and environmental conditions. In arid ecosystems of the southwestern USA, soil moisture exhibits large fluctuations because annual and seasonal precipitation inputs are highly variable, with increased variability expected in the future. Patterns of soil moisture, and periodic severe drought, are...

Regional and hemispheric influences on temporal variability in baseline carbon monoxide and ozone over the Northeast US

EPA Science Inventory

Interannual variability in baseline carbon monoxide (CO) and ozone (O3), defined as mixing ratios under minimal influence of recent and local emissions, was studied for seven rural sites in the Northeast US over 2001–2010. Annual baseline CO exhibited statistically signific...

Preparation and characterization of ibuprofen-cetyl alcohol beads by melt solidification technique: effect of variables.

PubMed

Maheshwari, Manish; Ketkar, Anant R; Chauhan, Bhaskar; Patil, Vinay B; Paradkar, Anant R

2003-08-11

Ibuprofen (IBU) exhibits short half-life, poor compressibility, flowability and caking tendency. IBU melt has sufficiently low viscosity and exhibits interfacial tension sufficient to form droplet even at low temperature. A single step novel melt solidification technique (MST) was developed to produce IBU beads with lower amounts of excipient. Effect of variables was studied using a 3(2) factorial approach with speed of agitation and amount of cetyl alcohol (CA) as variables. The beads were evaluated using DSC, FT-IR and scanning electron microscope (SEM). Yield, micromeritic properties, crushing strength and release kinetics were also studied. Spherical beads with a method yield of above 90% were obtained. The data was analyzed by response surface methodology. The variables showed curvilinear relationship with yield in desired particle size range, crushing strength and, bulk and tap density. The drug release followed non-Fickian case II transport and the release rate decreased linearly with respect to amount of CA in the initial stages followed by curvilinearity at later stages of elution. The effect of changing porosity and tortuosity was well correlated.

Operational Assessment of Apollo Lunar Surface Extravehicular Activity

NASA Technical Reports Server (NTRS)

Miller, Matthew James; Claybrook, Austin; Greenlund, Suraj; Marquez, Jessica J.; Feigh, Karen M.

2017-01-01

Quantifying the operational variability of extravehicular activity (EVA) execution is critical to help design and build future support systems to enable astronauts to monitor and manage operations in deep-space, where ground support operators will no longer be able to react instantly and manage execution deviations due to the significant communication latency. This study quantifies the operational variability exhibited during Apollo 14-17 lunar surface EVA operations to better understand the challenges and natural tendencies of timeline execution and life support system performance involved in surface operations. Each EVA (11 in total) is individually summarized as well as aggregated to provide descriptive trends exhibited throughout the Apollo missions. This work extends previous EVA task analyses by calculating deviations between planned and as-performed timelines as well as examining metabolic rate and consumables usage throughout the execution of each EVA. The intent of this work is to convey the natural variability of EVA operations and to provide operational context for coping with the variability inherent to EVA execution as a means to support future concepts of operations.

Effect of shock waves on the statistics and scaling in compressible isotropic turbulence

NASA Astrophysics Data System (ADS)

Wang, Jianchun; Wan, Minping; Chen, Song; Xie, Chenyue; Chen, Shiyi

2018-04-01

The statistics and scaling of compressible isotropic turbulence in the presence of large-scale shock waves are investigated by using numerical simulations at turbulent Mach number Mt ranging from 0.30 to 0.65. The spectra of the compressible velocity component, density, pressure, and temperature exhibit a k-2 scaling at different turbulent Mach numbers. The scaling exponents for structure functions of the compressible velocity component and thermodynamic variables are close to 1 at high orders n ≥3 . The probability density functions of increments of the compressible velocity component and thermodynamic variables exhibit a power-law region with the exponent -2 . Models for the conditional average of increments of the compressible velocity component and thermodynamic variables are developed based on the ideal shock relations and are verified by numerical simulations. The overall statistics of the compressible velocity component and thermodynamic variables are similar to one another at different turbulent Mach numbers. It is shown that the effect of shock waves on the compressible velocity spectrum and kinetic energy transfer is different from that of acoustic waves.

Multilocus variable-number tandem repeat analysis for molecular typing and phylogenetic analysis of Shigella flexneri

PubMed Central

2009-01-01

Background Shigella flexneri is one of the causative agents of shigellosis, a major cause of childhood mortality in developing countries. Multilocus variable-number tandem repeat (VNTR) analysis (MLVA) is a prominent subtyping method to resolve closely related bacterial isolates for investigation of disease outbreaks and provide information for establishing phylogenetic patterns among isolates. The present study aimed to develop an MLVA method for S. flexneri and the VNTR loci identified were tested on 242 S. flexneri isolates to evaluate their variability in various serotypes. The isolates were also analyzed by pulsed-field gel electrophoresis (PFGE) to compare the discriminatory power and to evaluate the usefulness of MLVA as a tool for phylogenetic analysis of S. flexneri. Results Thirty-six VNTR loci were identified by exploring the repeat sequence loci in genomic sequences of Shigella species and by testing the loci on nine isolates of different subserotypes. The VNTR loci in different serotype groups differed greatly in their variability. The discriminatory power of an MLVA assay based on four most variable VNTR loci was higher, though not significantly, than PFGE for the total isolates, a panel of 2a isolates, which were relatively diverse, and a panel of 4a/Y isolates, which were closely-related. Phylogenetic groupings based on PFGE patterns and MLVA profiles were considerably concordant. The genetic relationships among the isolates were correlated with serotypes. The phylogenetic trees constructed using PFGE patterns and MLVA profiles presented two distinct clusters for the isolates of serotype 3 and one distinct cluster for each of the serotype groups, 1a/1b/NT, 2a/2b/X/NT, 4a/Y, and 6. Isolates that had different serotypes but had closer genetic relatedness than those with the same serotype were observed between serotype Y and subserotype 4a, serotype X and subserotype 2b, subserotype 1a and 1b, and subserotype 3a and 3b. Conclusions The 36 VNTR loci identified exhibited considerably different degrees of variability among S. flexneri serotype groups. VNTR locus could be highly variable in a serotype but invariable in others. MLVA assay based on four highly variable loci could display a comparable resolving power to PFGE in discriminating isolates. MLVA is also a prominent molecular tool for phylogenetic analysis of S. flexneri; the resulting data are beneficial to establish clear clonal patterns among different serotype groups and to discern clonal groups among isolates within the same serotype. As highly variable VNTR loci could be serotype-specific, a common MLVA protocol that consists of only a small set of loci, for example four to eight loci, and that provides high resolving power to all S. flexneri serotypes may not be obtainable. PMID:20042119

RSIG Data Inventory

EPA Pesticide Factsheets

Remote Sensing Information Gateway, a tool that allows scientists, researchers and decision makers to access a variety of multi-terabyte, environmental datasets and to subset the data and obtain only needed variables, greatly improving the download time.

Remote Sensing Information Gateway

EPA Pesticide Factsheets

Remote Sensing Information Gateway, a tool that allows scientists, researchers and decision makers to access a variety of multi-terabyte, environmental datasets and to subset the data and obtain only needed variables, greatly improving the download time.

RSIG Video Demonstrations

EPA Pesticide Factsheets

Remote Sensing Information Gateway, a tool that allows scientists, researchers and decision makers to access a variety of multi-terabyte, environmental datasets and to subset the data and obtain only needed variables, greatly improving the download time.

How RSIG Regrids Data

EPA Pesticide Factsheets

Remote Sensing Information Gateway, a tool that allows scientists, researchers and decision makers to access a variety of multi-terabyte, environmental datasets and to subset the data and obtain only needed variables, greatly improving the download time.

Multivariate hydrological frequency analysis for extreme events using Archimedean copula. Case study: Lower Tunjuelo River basin (Colombia)

NASA Astrophysics Data System (ADS)

Gómez, Wilmar

2017-04-01

By analyzing the spatial and temporal variability of extreme precipitation events we can prevent or reduce the threat and risk. Many water resources projects require joint probability distributions of random variables such as precipitation intensity and duration, which can not be independent with each other. The problem of defining a probability model for observations of several dependent variables is greatly simplified by the joint distribution in terms of their marginal by taking copulas. This document presents a general framework set frequency analysis bivariate and multivariate using Archimedean copulas for extreme events of hydroclimatological nature such as severe storms. This analysis was conducted in the lower Tunjuelo River basin in Colombia for precipitation events. The results obtained show that for a joint study of the intensity-duration-frequency, IDF curves can be obtained through copulas and thus establish more accurate and reliable information from design storms and associated risks. It shows how the use of copulas greatly simplifies the study of multivariate distributions that introduce the concept of joint return period used to represent the needs of hydrological designs properly in frequency analysis.

Some aspects of river flow in northern New South Wales, Australia

NASA Astrophysics Data System (ADS)

Ward, R. C.

1984-03-01

A number of catchment and hydrological characteristics are examined for a 385,000 km 2 study area in northern New South Wales. This study area spans the Great Divide and data selected from the archives of the New South Wales Water Resources Commission illustrate the marked contrasts in the character and variability of streamflow between coastal rivers draining comparatively small steeply sloping basins east of the Great Divide and the larger river systems draining the more extensive semi-arid basins of the western slopes. Particular attention is paid to comparisons of annual flows, flow-duration curves, seasonal flow regimes, flood flow and low flows. The study not only confirms the hydrological contrasts between two distinct geographical regions but also emphasises the rigorous data requirements of hydrological studies in areas of high variability of precipitation and streamflow.

Novel Process of Simultaneous Removal of Nitric Oxide and Sulfur Dioxide Using a Vacuum Ultraviolet (VUV)-Activated O2/H2O/H2O2 System in A Wet VUV-Spraying Reactor.

PubMed

Liu, Yangxian; Wang, Qian; Pan, Jianfeng

2016-12-06

A novel process for NO and SO 2 simultaneous removal using a vacuum ultraviolet (VUV, with 185 nm wavelength)-activated O 2 /H 2 O/H 2 O 2 system in a wet VUV-spraying reactor was developed. The influence of different process variables on NO and SO 2 removal was evaluated. Active species (O 3 and ·OH) and liquid products (SO 3 2- , NO 2 - , SO 4 2- , and NO 3 - ) were analyzed. The chemistry and routes of NO and SO 2 removal were investigated. The oxidation removal system exhibits excellent simultaneous removal capacity for NO and SO 2 , and a maximum removal of 96.8% for NO and complete SO 2 removal were obtained under optimized conditions. SO 2 reaches 100% removal efficiency under most of test conditions. NO removal is obviously affected by several process variables. Increasing VUV power, H 2 O 2 concentration, solution pH, liquid-to-gas ratio, and O 2 concentration greatly enhances NO removal. Increasing NO and SO 2 concentration obviously reduces NO removal. Temperature has a dual impact on NO removal, which has an optimal temperature of 318 K. Sulfuric acid and nitric acid are the main removal products of NO and SO 2 . NO removals by oxidation of O 3 , O·, and ·OH are the primary routes. NO removals by H 2 O 2 oxidation and VUV photolysis are the complementary routes. A potential scaled-up removal process was also proposed initially.

Winter distribution and survival of a high-desert breeding population of canvasbacks

USGS Publications Warehouse

Kruse, K.L.; Lovvorn, J.R.; Takekawa, John Y.; MacKay, J.

2003-01-01

The southernmost major breeding area of Canvasbacks (Aythya valisineria) is located at the Ruby Lake National Wildlife Refuge, Nevada, in the high desert of the western Great Basin. We determined winter distributions, recovery rates, and survival for Canvasbacks banded in Nevada from March to November, 1968–2000. Winter recovery distributions did not differ by sex or age, but differed between direct recoveries (same year as banding) and indirect recoveries (after year of banding), indicating variable site use between years. Of direct band returns (October–March), 92% were from the Pacific Flyway and 56% were from California alone. In California, recovery distributions shifted from southern California and the San Francisco Bay estuary in the 1970s to the Central Valley in the 1980s and 1990s. In the 1990s, there were no recoveries in San Francisco Bay, historically the major wintering area for Canvasbacks in the Pacific Flyway. Adult and juvenile survival decreased by 24% between the 1980s and 1990s. Ruby Lake Canvasbacks exhibited weaker fidelity to wintering sites than Canvasbacks wintering on the Atlantic and Gulf coasts. Moreover, no major concentrations occurred during fall migration, unlike patterns in eastern North America. Shifts in distribution and survival may correspond to effects of El Niño weather on habitat conditions in Nevada and San Francisco Bay, and to major improvements in water delivery and wetland restoration in the Central Valley. Canvasbacks that use widely distributed and variable habitats may be good indicators of the effects of changing climate and water-use practices on waterbirds throughout this arid region.

On the impact of the resolution on the surface and subsurface Eastern Tropical Atlantic warm bias

NASA Astrophysics Data System (ADS)

Martín-Rey, Marta; Lazar, Alban

2016-04-01

The tropical variability has a great importance for the climate of adjacent areas. Its sea surface temperature anomalies (SSTA) affect in particular the Brazilian Nordeste and the Sahelian region, as well as the tropical Pacific or the Euro-Atlantic sector. Nevertheless, the state-of the art climate models exhibits very large systematic errors in reproducing the seasonal cycle and inter-annual variability in the equatorial and coastal Africa upwelling zones (up to several °C for SST). Theses biases exist already, in smaller proportions though, in forced ocean models (several 1/10th of °C), and affect not only the mixed layer but also the whole thermocline. Here, we present an analysis of the impact of horizontal and vertical resolution changes on these biases. Three different DRAKKAR NEMO OGCM simulations have been analysed, associated to the same forcing set (DFS4.4) with different grid resolutions: "REF" for reference (1/4°, 46 vertical levels), "HH" with a finer horizontal grid (1/12°, 46 v.l.) and "HV" with a finer vertical grid (1/4°, 75 v.l.). At the surface, a more realistic seasonal SST cycle is produced in HH in the three upwellings, where the warm bias decreases (by 10% - 20%) during boreal spring and summer. A notable result is that increasing vertical resolution in HV causes a shift (in advance) of the upwelling SST seasonal cycles. In order to better understand these results, we estimate the three upwelling subsurface temperature errors, using various in-situ datasets, and provide thus a three-dimensional view of the biases.

Global Shifts in Genome and Proteome Composition Are Very Tightly Coupled

PubMed Central

Brbić, Maria; Warnecke, Tobias; Kriško, Anita; Supek, Fran

2015-01-01

The amino acid composition (AAC) of proteomes differs greatly between microorganisms and is associated with the environmental niche they inhabit, suggesting that these changes may be adaptive. Similarly, the oligonucleotide composition of genomes varies and may confer advantages at the DNA/RNA level. These influences overlap in protein-coding sequences, making it difficult to gauge their relative contributions. We disentangle these effects by systematically evaluating the correspondence between intergenic nucleotide composition, where protein-level selection is absent, the AAC, and ecological parameters of 909 prokaryotes. We find that G + C content, the most frequently used measure of genomic composition, cannot capture diversity in AAC and across ecological contexts. However, di-/trinucleotide composition in intergenic DNA predicts amino acid frequencies of proteomes to the point where very little cross-species variability remains unexplained (91% of variance accounted for). Qualitatively similar results were obtained for 49 fungal genomes, where 80% of the variability in AAC could be explained by the composition of introns and intergenic regions. Upon factoring out oligonucleotide composition and phylogenetic inertia, the residual AAC is poorly predictive of the microbes’ ecological preferences, in stark contrast with the original AAC. Moreover, highly expressed genes do not exhibit more prominent environment-related AAC signatures than lowly expressed genes, despite contributing more to the effective proteome. Thus, evolutionary shifts in overall AAC appear to occur almost exclusively through factors shaping the global oligonucleotide content of the genome. We discuss these results in light of contravening evidence from biophysical data and further reading frame-specific analyses that suggest that adaptation takes place at the protein level. PMID:25971281

High-resolution experiments on chemical oxidation of DNAPL in variable-aperture fractures

NASA Astrophysics Data System (ADS)

Arshadi, Masoud; Rajaram, Harihar; Detwiler, Russell L.; Jones, Trevor

2015-04-01

Chemical oxidation of dense nonaqueous-phase liquids (DNAPLs) by permanganate has emerged as an effective remediation strategy in fractured rock. We present high-resolution experimental investigations in transparent analog variable-aperture fractures to improve understanding of chemical oxidation of residual entrapped trichloroethylene (TCE) in fractures. Four experiments were performed with different permanganate concentrations, flow rates, and initial TCE phase geometry. The initial aperture field and evolving entrapped-phase geometry were quantified for each experiment. The integrated mass transfer rate from the TCE phase for all experiments exhibited three time regimes: an early-time regime with slower mass transfer rates limited by low specific interfacial area; an intermediate-time regime with higher mass transfer rates resulting from breakup of large TCE blobs, which greatly increases specific interfacial area; and a late-time regime with low mass transfer rates due to the deposition of MnO2 precipitates. In two experiments, mass balance analyses suggested that TCE mass removal rates exceeded the maximum upper bound mass removal rates derived by assuming that oxidation and dissolution are the only mechanisms for TCE mass removal. We propose incomplete oxidation by permanganate and TCE solubility enhancement by intermediate reaction products as potential mechanisms to explain this behavior. We also speculate that some intermediate reaction products with surfactant-like properties may play a role in lowering the TCE-water interfacial tension, thus causing breakup of large TCE blobs. Our quantitative experimental measurements will be useful in the context of developing accurate computational models for chemical oxidation of TCE in fractures.

Hyperspectral image classification by a variable interval spectral average and spectral curve matching combined algorithm

NASA Astrophysics Data System (ADS)

Senthil Kumar, A.; Keerthi, V.; Manjunath, A. S.; Werff, Harald van der; Meer, Freek van der

2010-08-01

Classification of hyperspectral images has been receiving considerable attention with many new applications reported from commercial and military sectors. Hyperspectral images are composed of a large number of spectral channels, and have the potential to deliver a great deal of information about a remotely sensed scene. However, in addition to high dimensionality, hyperspectral image classification is compounded with a coarse ground pixel size of the sensor for want of adequate sensor signal to noise ratio within a fine spectral passband. This makes multiple ground features jointly occupying a single pixel. Spectral mixture analysis typically begins with pixel classification with spectral matching techniques, followed by the use of spectral unmixing algorithms for estimating endmembers abundance values in the pixel. The spectral matching techniques are analogous to supervised pattern recognition approaches, and try to estimate some similarity between spectral signatures of the pixel and reference target. In this paper, we propose a spectral matching approach by combining two schemes—variable interval spectral average (VISA) method and spectral curve matching (SCM) method. The VISA method helps to detect transient spectral features at different scales of spectral windows, while the SCM method finds a match between these features of the pixel and one of library spectra by least square fitting. Here we also compare the performance of the combined algorithm with other spectral matching techniques using a simulated and the AVIRIS hyperspectral data sets. Our results indicate that the proposed combination technique exhibits a stronger performance over the other methods in the classification of both the pure and mixed class pixels simultaneously.

Decision making in healthy participants on the Iowa Gambling Task: new insights from an operant approach.

PubMed

Bull, Peter N; Tippett, Lynette J; Addis, Donna Rose

2015-01-01

The Iowa Gambling Task (IGT) has contributed greatly to the study of affective decision making. However, researchers have observed high inter-study and inter-individual variability in IGT performance in healthy participants, and many are classified as impaired using standard criteria. Additionally, while decision-making deficits are often attributed to atypical sensitivity to reward and/or punishment, the IGT lacks an integrated sensitivity measure. Adopting an operant perspective, two experiments were conducted to explore these issues. In Experiment 1, 50 healthy participants completed a 200-trial version of the IGT which otherwise closely emulated Bechara et al.'s (1999) original computer task. Group data for Trials 1-100 closely replicated Bechara et al.'s original findings of high net scores and preferences for advantageous decks, suggesting that implementations that depart significantly from Bechara's standard IGT contribute to inter-study variability. During Trials 101-200, mean net scores improved significantly and the percentage of participants meeting the "impaired" criterion was halved. An operant-style stability criterion applied to individual data revealed this was likely related to individual differences in learning rate. Experiment 2 used a novel operant card task-the Auckland Card Task (ACT)-to derive quantitative estimates of sensitivity using the generalized matching law. Relative to individuals who mastered the IGT, persistent poor performers on the IGT exhibited significantly lower sensitivity to magnitudes (but not frequencies) of rewards and punishers on the ACT. Overall, our findings demonstrate the utility of operant-style analysis of IGT data and the potential of applying operant concurrent-schedule procedures to the study of human decision making.

Zooxanthellae harvested by ciliates associated with brown band syndrome of corals remain photosynthetically competent.

PubMed

Ulstrup, Karin E; Kühl, Michael; Bourne, David G

2007-03-01

Brown band syndrome is a new coral affliction characterized by a local accumulation of yet-unidentified ciliates migrating as a band along the branches of coral colonies. In the current study, morphologically intact zooxanthellae (= Symbiodinium) were observed in great numbers inside the ciliates (>50 dinoflagellates per ciliate). Microscale oxygen measurements and variable chlorophyll a fluorescence analysis along with microscopic observations demonstrated that zooxanthellae within the ciliates are photosynthetically competent and do not become compromised during the progression of the brown band zone. Zooxanthellae showed similar trends in light acclimation in a comparison of rapid light curve and steady-state light curve measures of variable chlorophyll a fluorescence. Extended light exposure of steady-state light curves resulted in higher quantum yields of photosystem II. The brown band tissue exhibited higher photosynthetically active radiation absorptivity, indicating more efficient light absorption due to a higher density of zooxanthellae in the ciliate-dominated zone. This caused relatively higher gross photosynthesis rates in the zone with zooxanthella-containing ciliates compared to healthy coral tissue. The observation of photosynthetically active intracellular zooxanthellae in the ciliates suggests that the latter can benefit from photosynthates produced by ingested zooxanthellae and from photosynthetic oxygen production that alleviates diffusion limitation of oxic respiration in the densely populated brown band tissue. It remains to be shown whether the zooxanthellae form a stable symbiotic association with the ciliate or are engulfed incidentally during grazing on coral tissue and then maintained as active inside the ciliate for a period before being digested and replaced by new zooxanthellae.

Zooxanthellae Harvested by Ciliates Associated with Brown Band Syndrome of Corals Remain Photosynthetically Competent▿

PubMed Central

Ulstrup, Karin E.; Kühl, Michael; Bourne, David G.

2007-01-01

Brown band syndrome is a new coral affliction characterized by a local accumulation of yet-unidentified ciliates migrating as a band along the branches of coral colonies. In the current study, morphologically intact zooxanthellae (= Symbiodinium) were observed in great numbers inside the ciliates (>50 dinoflagellates per ciliate). Microscale oxygen measurements and variable chlorophyll a fluorescence analysis along with microscopic observations demonstrated that zooxanthellae within the ciliates are photosynthetically competent and do not become compromised during the progression of the brown band zone. Zooxanthellae showed similar trends in light acclimation in a comparison of rapid light curve and steady-state light curve measures of variable chlorophyll a fluorescence. Extended light exposure of steady-state light curves resulted in higher quantum yields of photosystem II. The brown band tissue exhibited higher photosynthetically active radiation absorptivity, indicating more efficient light absorption due to a higher density of zooxanthellae in the ciliate-dominated zone. This caused relatively higher gross photosynthesis rates in the zone with zooxanthella-containing ciliates compared to healthy coral tissue. The observation of photosynthetically active intracellular zooxanthellae in the ciliates suggests that the latter can benefit from photosynthates produced by ingested zooxanthellae and from photosynthetic oxygen production that alleviates diffusion limitation of oxic respiration in the densely populated brown band tissue. It remains to be shown whether the zooxanthellae form a stable symbiotic association with the ciliate or are engulfed incidentally during grazing on coral tissue and then maintained as active inside the ciliate for a period before being digested and replaced by new zooxanthellae. PMID:17259357

Spectral Variability in the Aged Brain during Fine Motor Control

PubMed Central

Quandt, Fanny; Bönstrup, Marlene; Schulz, Robert; Timmermann, Jan E.; Zimerman, Maximo; Nolte, Guido; Hummel, Friedhelm C.

2016-01-01

Physiological aging is paralleled by a decline of fine motor skills accompanied by structural and functional alterations of the underlying brain network. Here, we aim to investigate age-related changes in the spectral distribution of neuronal oscillations during fine skilled motor function. We employ the concept of spectral entropy in order to describe the flatness and peaked-ness of a frequency spectrum to quantify changes in the spectral distribution of the oscillatory motor response in the aged brain. Electroencephalogram was recorded in elderly (n = 32) and young (n = 34) participants who performed either a cued finger movement or a pinch or a whole hand grip task with their dominant right hand. Whereas young participant showed distinct, well-defined movement-related power decreases in the alpha and upper beta band, elderly participants exhibited a flat broadband, frequency-unspecific power desynchronization. This broadband response was reflected by an increase of spectral entropy over sensorimotor and frontal areas in the aged brain. Neuronal activation patterns differed between motor tasks in the young brain, while the aged brain showed a similar activation pattern in all tasks. Moreover, we found a wider recruitment of the cortical motor network in the aged brain. The present study adds to the understanding of age-related changes of neural coding during skilled motor behavior, revealing a less predictable signal with great variability across frequencies in a wide cortical motor network in the aged brain. The increase in entropy in the aged brain could be a reflection of random noise-like activity or could represent a compensatory mechanism that serves a functional role. PMID:28066231

Diagnosing Cloud Biases in the GFDL AM3 Model With Atmospheric Classification

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

Evans, Stuart; Marchand, Roger; Ackerman, Thomas

In this paper, we define a set of 21 atmospheric states, or recurring weather patterns, for a region surrounding the Atmospheric Radiation Measurement Program's Southern Great Plains site using an iterative clustering technique. The states are defined using dynamic and thermodynamic variables from reanalysis, tested for statistical significance with cloud radar data from the Southern Great Plains site, and are determined every 6 h for 14 years, creating a time series of atmospheric state. The states represent the various stages of the progression of synoptic systems through the region (e.g., warm fronts, warm sectors, cold fronts, cold northerly advection, andmore » high-pressure anticyclones) with a subset of states representing summertime conditions with varying degrees of convective activity. We use the states to classify output from the NOAA/Geophysical Fluid Dynamics Laboratory AM3 model to test the model's simulation of the frequency of occurrence of the states and of the cloud occurrence during each state. The model roughly simulates the frequency of occurrence of the states but exhibits systematic cloud occurrence biases. Comparison of observed and model-simulated International Satellite Cloud Climatology Project histograms of cloud top pressure and optical thickness shows that the model lacks high thin cloud under all conditions, but biases in thick cloud are state-dependent. Frontal conditions in the model do not produce enough thick cloud, while fair-weather conditions produce too much. Finally, we find that increasing the horizontal resolution of the model improves the representation of thick clouds under all conditions but has little effect on high thin clouds. However, increasing resolution also changes the distribution of states, causing an increase in total cloud occurrence bias.« less

Abundance and characteristics of the recreational water quality indicator bacteria Escherichia coli and enterococci in gull faeces

USGS Publications Warehouse

Fogarty, L.R.; Haack, S.K.; Wolcott, M.J.; Whitman, R.L.

2003-01-01

Aims: To evaluate the numbers and selected phenotypic and genotypic characteristics of the faecal indicator bacteria Escherichia coli and enterococci in gull faeces at representative Great Lakes swimming beaches in the United States. Methods and Results: E. coli and enterococci were enumerated in gull faeces by membrane filtration. E. coli genotypes (rep-PCR genomic profiles) and E. coli (Vitek?? GNI+) and enterococci (API?? rapid ID 32 Strep and resistance to streptomycin, gentamicin, vancomycin, tetracycline and ampicillin) phenotypes were determined for isolates obtained from gull faeces both early and late in the swimming season. Identical E. coli genotypes were obtained only from single gull faecal samples but most faecal samples yielded more than one genotype (median of eight genotypes for samples with 10 isolates). E. coli isolates from the same site that clustered at ???85% similarity were from the same sampling date and shared phenotypic characteristics, and at this similarity level there was population overlap between the two geographically isolated beach sites. Enterococcus API?? profiles varied with sampling date. Gull enterococci displayed wide variation in antibiotic resistance patterns, and high-level resistance to some antibiotics. Conclusions: Gull faeces could be a major contributor of E. coli (105-109 CFU g-1) and enterococci (104-108 CFU g-1) to Great Lakes recreational waters. E. coli and enterococci in gull faeces are highly variable with respect to their genotypic and phenotypic characteristics and may exhibit temporal or geographic trends in these features. Significance and Impact of the Study: The high degree of variation in genotypic or phenotypic characteristics of E. coli or enterococci populations within gull hosts will require extensive sampling for adequate characterization, and will influence methods that use these characteristics to determine faecal contamination sources for recreational waters.

Climatic and hydrologic influences on wading bird foraging patterns in Everglades National Park

NASA Astrophysics Data System (ADS)

Kwon, H.; Lall, U.; Engel, V.

2007-12-01

A goal of the Everglades National Park (ENP) restoration project is to ensure that the ecological health of the ENP improves as a direct result of management activities. Achieving hydrologic targets through the proper timing and amount of releases from control structures is a first step in the management process. Significant climate and weather variations in the region influence the ability to make releases and also determine the ecological outcomes. An assessment of the relative impact of climate variations and water releases to ENP in determining ecological outcomes is consequently a key to the evaluation of the success or failure of any restoration plan. Seasonal water depths in ENP depend on managed surface water releases from control structures and on direct rainfall. Here we link wading bird foraging patterns - a fundamental aspect of Everglades' ecology - to hydrologic management and climate variability in the National Park. Our objective is multifold. First, we relate the water levels at P33 and Shark Slough to the synoptic hydrologic conditions. Second, we develop a statistical model relating water levels at a station in central Shark Slough (P33) to wading birds foraging patterns throughout ENP. We attempt to apply a Hierarchical Bayesian scheme to a time series of wading bird to provide an uncertainty distribution of the population over specified time periods given hydrologic condition. Third, we develop a set of hydrologic index derived by recorded water level at P33 for a use of the statistical model of wading birds as an input. Our study will focus on great egret and white ibis that are major species among wading birds in the ENP. The great egret and white ibis prediction predicted by the model using the proposed predictors exhibits strong correlation with the observed streamflow, with an correlation 0.8.

Complex MHC class I gene transcription profiles and their functional impact in orangutans

PubMed Central

de Groot, Natasja G.; Heijmans, Corrine M.C.; van der Wiel, Marit K.H.; Blokhuis, Jeroen H.; Mulder, Arend; Guethlein, Lisbeth A.; Doxiadis, Gaby G.M.; Claas, Frans H.J.; Parham, Peter; Bontrop, Ronald E.

2015-01-01

MHC haplotypes of humans and the African great ape species have one copy of the MHC-A, -B, and -C genes. In contrast, MHC haplotypes of orangutans, the Asian great ape species, exhibit variation in the number of gene copies. An in-depth analysis of the MHC class I gene repertoire in the two orangutan species, Pongo abelii and Pongo pygmaeus, is presented here. This analysis involved Sanger and next-generation sequencing methodologies, revealing diverse and complicated transcription profiles for orangutan MHC-A, -B, and -C. Thirty-five previously unreported MHC class I alleles are described. The data demonstrate that each orangutan MHC haplotype has one copy of the MHC-A gene, and that the MHC-B region has been subject to duplication, giving rise to at least three MHC-B genes. The MHC-B*03 and -B*08 lineages of alleles each account for a separate MHC-B gene. All MHC-B*08 allotypes have the C1-epitope motif recognized by KIR. At least one other MHC-B gene is present, pointing to MHC-B alleles that are not B*03 or B*08. The MHC-C gene is present only on some haplotypes, and each MHC-C allotype has the C1-epitope. The transcription profiles demonstrate that MHC-A alleles are highly transcribed, whereas MHC-C alleles, when present, are transcribed at very low levels. The MHC-B alleles are transcribed to a variable extent and over a wide range. For those orangutan MHC class I allotypes that are detected by human monoclonal anti-HLA class I antibodies, the level of cell-surface expression of proteins correlates with the level of transcription of the allele. PMID:26685209

Abrupt Climate Change in the Southern Great Plains during the Last Glacial Interval

NASA Astrophysics Data System (ADS)

Housson, A. L.; Maupin, C. R.; Roark, B.; Shen, C. C.; Baykara, O.; White, K.; Kampen-Lewis, S. V.; McChesney, C. L.

2016-12-01

Understanding how the climate of the North American Great Plains may change in the future is of tremendous socioeconomic importance, yet the regional response to previous abrupt global climate events, such as the Dansgaard-Oeschger (DO) cycles of the last glacial interval, are poorly known. Here we present two absolutely dated (U/Th), partially replicated oxygen isotope (δ18O) records from calcite speleothems in central Texas (30° N, 98° W) that grew during marine isotope stage 3 (MIS 3) (31 to 49 ky BP). The study site experiences boreal spring and fall maxima in precipitation with rainfall moisture sourced almost exclusively from the Gulf of Mexico. The two samples exhibit reproducible δ18O means and variability during overlapping growth intervals. Weak correlations between paired oxygen and carbon isotopic values coupled with reproducible δ18O strongly suggest that dripwater δ18O and calcite formation temperatures are the primary drivers of speleothem δ18O variations through time. We interpret more depleted (enriched) δ18O values to reconstruct warmer and wetter (cooler and drier) conditions based on observations of modern rainfall stable isotope variations at the study site. We find that warmer and wetter conditions in the Southern Plains are contemporaneous with MIS 3 DO interstadials, while cooler and more arid conditions prevail during stadials and Heinrich Events 4 and 5. Our results show a response opposite that of hydrologic reconstructions from the American Southwest, where wetter conditions occur with stadial conditions. Future work includes exploration of paleoclimate model results to examine potential mechanisms responsible for this opposite phasing. Our speleothem data indicate that further intensification of rainy seasons in the Southern Plains should not be ruled out as a response to anthropogenic global warming.

Patch size and edge proximity are useful predictors of brood parasitism but not nest survival of grassland birds.

PubMed

Benson, Thomas J; Chiavacci, Scott J; Ward, Michael P

2013-06-01

Declines of migratory birds have led to increased focus on causative factors for these declines, including the potential adverse effects of habitat fragmentation on reproductive success. Although numerous studies have addressed how proximity to a habitat edge, patch size, or landscape context influence nest survival or brood parasitism, many have failed to find the purported effects. Furthermore, many have sought to generalize patterns across large geographic areas and habitats. Here, we examined evidence for effects of edge proximity, patch size, and landscape context on nest survival and brood parasitism of grassland birds, a group of conservation concern. The only consistent effect was a positive association between edge proximity and brood parasitism. We examined effects of patch size on nest survival (37 studies) and brood parasitism (30 studies) representing 170 and 97 different estimates, respectively, with a total sample size of > 14000 nests spanning eastern North America. Nest survival weakly increased with patch size in the Great Plains, but not in the Midwestern or Eastern United States, and brood parasitism was inversely related to patch size and consistently greater in the Great Plains. The consistency in brood parasitism relative to nest survival patterns is likely due to parasitism being caused by one species, while nest survival is driven by a diverse and variable suite of nest predators. Often, studies assume that predators responsible for nest predation, the main driver of nest success, either are the same or exhibit the same behaviors across large geographic areas. These results suggest that a better mechanistic understanding of nest predation is needed to provide meaningful conservation recommendations for improving grassland bird productivity, and that the use of general recommendations across large geographic areas should only be undertaken when sufficient data are available from all regions.

Diagnosing Cloud Biases in the GFDL AM3 Model With Atmospheric Classification

NASA Astrophysics Data System (ADS)

Evans, Stuart; Marchand, Roger; Ackerman, Thomas; Donner, Leo; Golaz, Jean-Christophe; Seman, Charles

2017-12-01

We define a set of 21 atmospheric states, or recurring weather patterns, for a region surrounding the Atmospheric Radiation Measurement Program's Southern Great Plains site using an iterative clustering technique. The states are defined using dynamic and thermodynamic variables from reanalysis, tested for statistical significance with cloud radar data from the Southern Great Plains site, and are determined every 6 h for 14 years, creating a time series of atmospheric state. The states represent the various stages of the progression of synoptic systems through the region (e.g., warm fronts, warm sectors, cold fronts, cold northerly advection, and high-pressure anticyclones) with a subset of states representing summertime conditions with varying degrees of convective activity. We use the states to classify output from the NOAA/Geophysical Fluid Dynamics Laboratory AM3 model to test the model's simulation of the frequency of occurrence of the states and of the cloud occurrence during each state. The model roughly simulates the frequency of occurrence of the states but exhibits systematic cloud occurrence biases. Comparison of observed and model-simulated International Satellite Cloud Climatology Project histograms of cloud top pressure and optical thickness shows that the model lacks high thin cloud under all conditions, but biases in thick cloud are state-dependent. Frontal conditions in the model do not produce enough thick cloud, while fair-weather conditions produce too much. We find that increasing the horizontal resolution of the model improves the representation of thick clouds under all conditions but has little effect on high thin clouds. However, increasing resolution also changes the distribution of states, causing an increase in total cloud occurrence bias.

Diagnosing Cloud Biases in the GFDL AM3 Model With Atmospheric Classification

DOE PAGES

Evans, Stuart; Marchand, Roger; Ackerman, Thomas; ...

2017-11-16

In this paper, we define a set of 21 atmospheric states, or recurring weather patterns, for a region surrounding the Atmospheric Radiation Measurement Program's Southern Great Plains site using an iterative clustering technique. The states are defined using dynamic and thermodynamic variables from reanalysis, tested for statistical significance with cloud radar data from the Southern Great Plains site, and are determined every 6 h for 14 years, creating a time series of atmospheric state. The states represent the various stages of the progression of synoptic systems through the region (e.g., warm fronts, warm sectors, cold fronts, cold northerly advection, andmore » high-pressure anticyclones) with a subset of states representing summertime conditions with varying degrees of convective activity. We use the states to classify output from the NOAA/Geophysical Fluid Dynamics Laboratory AM3 model to test the model's simulation of the frequency of occurrence of the states and of the cloud occurrence during each state. The model roughly simulates the frequency of occurrence of the states but exhibits systematic cloud occurrence biases. Comparison of observed and model-simulated International Satellite Cloud Climatology Project histograms of cloud top pressure and optical thickness shows that the model lacks high thin cloud under all conditions, but biases in thick cloud are state-dependent. Frontal conditions in the model do not produce enough thick cloud, while fair-weather conditions produce too much. Finally, we find that increasing the horizontal resolution of the model improves the representation of thick clouds under all conditions but has little effect on high thin clouds. However, increasing resolution also changes the distribution of states, causing an increase in total cloud occurrence bias.« less

Analyzing the responses of species assemblages to climate change across the Great Basin, USA.

NASA Astrophysics Data System (ADS)

Henareh Khalyani, A.; Falkowski, M. J.; Crookston, N.; Yousef, F.

2016-12-01

The potential impacts of climate change on the future distribution of tree species in not well understood. Climate driven changes in tree species distribution could cause significant changes in realized species niches, potentially resulting in the loss of ecotonal species as well as the formation on novel assemblages of overlapping tree species. In an effort to gain a better understating of how the geographic distribution of tree species may respond to climate change, we model the potential future distribution of 50 different tree species across 70 million ha in the Great Basin, USA. This is achieved by leveraging a species realized niche model based on non-parametric analysis of species occurrences across climatic, topographic, and edaphic variables. Spatially explicit, high spatial resolution (30 m) climate variables (e.g., precipitation, and minimum, maximum, and mean temperature) and associated climate indices were generated on an annual basis between 1981-2010 by integrating climate station data with digital elevation data (Shuttle Radar Topographic Mission (SRTM) data) in a thin plate spline interpolation algorithm (ANUSPLIN). Bioclimate models of species niches in in the cotemporary period and three following 30 year periods were then generated by integrating the climate variables, soil data, and CMIP 5 general circulation model projections. Our results suggest that local scale contemporary variations in species realized niches across space are influenced by edaphic and topographic variables as well as climatic variables. The local variability in soil properties and topographic variability across space also affect the species responses to climate change through time and potential formation of species assemblages in future. The results presented here in will aid in the development of adaptive forest management techniques aimed at mitigating negative impacts of climate change on forest composition, structure, and function.

A population on the rise: The origin of deepwater sculpin in Lake Ontario

USGS Publications Warehouse

Welsh, Amy B.; Scribner, Kim T.; Stott, Wendylee; Walsh, Maureen

2017-01-01

Deepwater sculpin, Myoxocephalus thompsonii, were thought to have been extirpated from Lake Ontario. However, in recent years, abundance has increased and recruitment has been documented. There are two hypotheses concerning the origin of the current Lake Ontario deepwater sculpin population. First, individuals from the upper Great Lakes may have recolonized Lake Ontario. Alternatively, the Lake Ontario population may have not been extirpated, and the remnant population has recovered naturally. To test these hypotheses, eight microsatellite loci were used to analyze samples from the current Lake Ontario population, museum specimens from the historic Lake Ontario population, and current upper Great Lakes populations. The genetic data suggest that historically throughout the Great Lakes, deepwater sculpin exhibited low levels of spatial genetic structure. Approximate Bayesian Computation analyses support the hypothesis that the current Lake Ontario population is more closely related to populations in the upper Great Lakes than to the historic Lake Ontario samples, indicating that the current Lake Ontario population likely resulted from recolonization from the Upper Great Lakes. The current Lake Ontario population has reduced allelic diversity relative to upper Great Lakes populations, indicating a possible founder effect. This study demonstrates the role life history variation can play in recolonization success. The pelagic larval phase of the deepwater sculpin allowed recolonization of Lake Ontario via passive larval drift.

Selective wetting-induced micro-electrode patterning for flexible micro-supercapacitors.

PubMed

Kim, Sung-Kon; Koo, Hyung-Jun; Lee, Aeri; Braun, Paul V

2014-08-13

Selective wetting-induced micro-electrode patterning is used to fabricate flexible micro-supercapacitors (mSCs). The resulting mSCs exhibit high performance, mechanical stability, stable cycle life, and hold great promise for facile integration into flexible devices requiring on-chip energy storage. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Developmental Assets: Profile of Youth in a Juvenile Justice Facility

ERIC Educational Resources Information Center

Chew, Weslee; Osseck, Jenna; Raygor, Desiree; Eldridge-Houser, Jennifer; Cox, Carol

2010-01-01

Background: Possessing high numbers of developmental assets greatly reduces the likelihood of a young person engaging in health-risk behaviors. Since youth in the juvenile justice system seem to exhibit many high-risk behaviors, the purpose of this study was to assess the presence of external, internal, and social context areas of developmental…

Evaluation Techniques for the Sandy Point Discovery Center, Great Bay National Estuarine Research Reserve.

ERIC Educational Resources Information Center

Heffernan, Bernadette M.

1998-01-01

Describes work done to provide staff of the Sandy Point Discovery Center with methods for evaluating exhibits and interpretive programming. Quantitative and qualitative evaluation measures were designed to assess the program's objective of estuary education. Pretest-posttest questionnaires and interviews are used to measure subjects' knowledge and…

Printing without Ink

ERIC Educational Resources Information Center

Thompson, James P.

2005-01-01

Often we find great ideas around the artroom. One day, the author spotted several pieces of construction paper that had gotten wet near the sink. They had stained the white paper they were lying on. He noticed a design of strong contrast exhibited by the stains. Layers of transparent color had created textural nuances resembling a multicolored…

Establishment and early growth of Populus hybrids irrigated with landfill leachate

Treesearch

Ronald S., Jr. Zalesny; Adam H. Wiese; Edmund O. Bauer; Jill A. Zalesny

2007-01-01

Hybrid poplar genotypes exhibit great potential for tree establishment and growth when irrigated with municipal solid waste landfill leachate. We evaluated the potential for establishment on leachate-irrigated soils by testing: 1) aboveground growth of hybrid poplar during repeated irrigation with landfill leachate and 2) aboveground and belowground biomass after 70 d...

Thermally stable, plastic-bonded explosives

DOEpatents

Benziger, Theodore M.

1979-01-01

By use of an appropriate thermoplastic rubber as the binder, the thermal stability and thermal stress characteristics of plastic-bonded explosives may be greatly improved. In particular, an HMX-based explosive composition using an oil-extended styrene-ethylenebutylene-styrene block copolymer as the binder exhibits high explosive energy and thermal stability and good handling safety and physical properties.

Effects of a spring prescribed burn on the soil seed bank in sagebrush steppe exhibiting pinyon-juniper expansion

Treesearch

Elizabeth A. Allen; Jeanne C. Chambers; Robert S. Nowak

2008-01-01

Pinyon-juniper (Pinus monophylla-Juniperus osteosperma) woodlands are expanding into shrubsteppe ecosystems in western portions of the Great Basin. Often, highly competitive trees displace the understory, and prescribed fire is increasingly used as a restoration tool. To inform management decisions about post-fire recovery, we...

Slaying the Great Green Dragon: Learning and Modelling Iterable Ordered Optional Adjuncts

ERIC Educational Resources Information Center

Fowlie, Meaghan

2017-01-01

Adjuncts and arguments exhibit different syntactic behaviours, but modelling this difference in minimalist syntax is challenging: on the one hand, adjuncts differ from arguments in that they are optional, transparent, and iterable, but on the other hand they are often strictly ordered, reflecting the kind of strict selection seen in argument…

Teaching Methodology of Flexible Pavement Materials and Pavement Systems

ERIC Educational Resources Information Center

Mehta, Yusuf; Najafi, Fazil

2004-01-01

Flexible pavement materials exhibit complex mechanical behavior, in the sense, that they not only show stress and temperature dependency but also are sensitive to moisture conditions. This complex behavior presents a great challenge to the faculty in bringing across the level of complexity and providing the concepts needed to understand them. The…

Redox-Responsive Biomimetic Polymeric Micelle for Simultaneous Anticancer Drug Delivery and Aggregation-Induced Emission Active Imaging.

PubMed

Hu, Jun; Zhuang, Weihua; Ma, Boxuan; Su, Xin; Yu, Tao; Li, Gaocan; Hu, Yanfei; Wang, Yunbing

2018-05-10

Intelligent polymeric micelles have been developed as potential nanoplatforms for efficient drug delivery and diagnosis. Herein, we successfully prepared redox-sensitive polymeric micelles combined aggregation-induced emission (AIE) imaging as an outstanding anticancer drug carrier system for simultaneous chemotherapy and bioimaging. The amphiphilic copolymer TPE-SS-PLAsp- b-PMPC could self-assemble into spherical micelles, and these biomimetic micelles exhibited great biocompatibility and remarkable ability in antiprotein adsorption, showing great potential for biomedical application. Anticancer drug doxorubicin (DOX) could be encapsulated during the self-assembly process, and these drug-loaded micelles showed intelligent drug release and improved antitumor efficacy due to the quick disassembly in response to high levels of glutathione (GSH) in the environment. Moreover, the intracellular DOX release could be traced through the fluorescent imaging of these AIE micelles. As expected, the in vivo antitumor study exhibited that these DOX-carried micelles showed better antitumor efficacy and less adverse effects than that of free DOX. These results strongly indicated that this smart biomimetic micelle system would be a prominent candidate for chemotherapy and bioimaging.

Constructing Free Standing Metal Organic Framework MIL-53 Membrane Based on Anodized Aluminum Oxide Precursor

PubMed Central

Zhang, Yunlu; Gao, Qiuming; Lin, Zhi; Zhang, Tao; Xu, Jiandong; Tan, Yanli; Tian, Weiqian; Jiang, Lei

2014-01-01

Metal organic framework (MOF) materials have attracted great attention due to their well-ordered and controllable pores possessing of prominent potentials for gas molecule sorption and separation performances. Organizing the MOF crystals to a continuous membrane with a certain scale will better exhibit their prominent potentials. Reports in recent years concentrate on well grown MOF membranes on specific substrates. Free standing MOF membranes could have more important applications since they are independent from the substrates. However, the method to prepare such a membrane has been a great challenge because good mechanical properties and stabilities are highly required. Here, we demonstrate a novel and facile technique for preparing the free standing membrane with a size as large as centimeter scale. The substrate we use proved itself not only a good skeleton but also an excellent precursor to fulfill the reaction. This kind of membrane owns a strong mechanical strength, based on the fact that it is much thinner than the composite membranes grown on substrates and it could exhibit good property of gas separation. PMID:24821299

Unique pattern of dietary adaptation in the dentition of Carnivora: its advantage and developmental origin

PubMed Central

Saito, Kazuyuki; Kishida, Takushi; Takahashi, Katsu; Bessho, Kazuhisa

2016-01-01

Carnivora is a successful taxon in terms of dietary diversity. We investigated the dietary adaptations of carnivoran dentition and the developmental background of their dental diversity, which may have contributed to the success of the lineage. A developmental model was tested and extended to explain the unique variability and exceptional phenotypes observed in carnivoran dentition. Carnivorous mammalian orders exhibited two distinct patterns of dietary adaptation in molars and only Carnivora evolved novel variability, exhibiting a high correlation between relative molar size and the shape of the first molar. Studies of Bmp7-hetero-deficient mice, which may exhibit lower Bmp7 expression, suggested that Bmp7 has pleiotropic effects on these two dental traits. Its effects are consistent with the pattern of dietary adaptation observed in Carnivora, but not that observed in other carnivorous mammals. A molecular evolutionary analysis revealed that Bmp7 sequence evolved by natural selection during ursid evolution, suggesting that it plays an evolutionary role in the variation of carnivoran dentition. Using mouse experiments and a molecular evolutionary analysis, we extrapolated the causal mechanism of the hitherto enigmatic ursid dentition (larger M2 than M1 and M3). Our results demonstrate how carnivorans acquired novel dental variability that benefits their dietary divergence.

Analysis of pelvic rotation on the standard hip ventrodorsal extended radiographic view.

PubMed

Martins, João; Colaço, Bruno J; Ferreira, António J; Ginja, Mário M

2016-01-01

To study the symmetry of the iliac horizontal diameter (IHD) maximum obturator foramen width (OFW), ischiatic femoral overlap (IFO), pelvic horizontal radius (PHR), femoral head diameter (FHD), and obturator foramen area (OFA) parameters in the normal hip extended radiographic view and to evaluate the correlation of pelvic rotation with the magnitude of asymmetry of these parameters. Nine canine cadavers from adult, large and giant breeds were radiographed in standard hip extended views and with 2°, 4° and 6° degrees of rotation. The variables IHD, OFW, IFO, PHR, FHD, and OFA were analysed in radiographs. The IHD measurements exhibited repeatability, bilateral symmetry and 95% of confidence interval of asymmetry in different pelvic rotations without superposition (p <0.05); OFW and IFO exhibited repeatability, bilateral symmetry and a small superposition in 95% of confidence interval of asymmetry according different pelvic rotations; PHR, FHD and OFA exhibited repeatability, bilateral symmetry and unacceptable superposition in 95% of confidence interval of asymmetry depending on pelvic rotation. The IHD is the recommended variable and OFW is an acceptable variable in order to evaluate slight pelvic rotation. The data may be used in qualitative analyses of hip extended radiographic views. In the future, complementary studies should be performed to evaluate the impact of degree of pelvic rotation on the hip dysplasia score.

An example of complex modelling in dentistry using Markov chain Monte Carlo (MCMC) simulation.

PubMed

Helfenstein, Ulrich; Menghini, Giorgio; Steiner, Marcel; Murati, Francesca

2002-09-01

In the usual regression setting one regression line is computed for a whole data set. In a more complex situation, each person may be observed for example at several points in time and thus a regression line might be calculated for each person. Additional complexities, such as various forms of errors in covariables may make a straightforward statistical evaluation difficult or even impossible. During recent years methods have been developed allowing convenient analysis of problems where the data and the corresponding models show these and many other forms of complexity. The methodology makes use of a Bayesian approach and Markov chain Monte Carlo (MCMC) simulations. The methods allow the construction of increasingly elaborate models by building them up from local sub-models. The essential structure of the models can be represented visually by directed acyclic graphs (DAG). This attractive property allows communication and discussion of the essential structure and the substantial meaning of a complex model without needing algebra. After presentation of the statistical methods an example from dentistry is presented in order to demonstrate their application and use. The dataset of the example had a complex structure; each of a set of children was followed up over several years. The number of new fillings in permanent teeth had been recorded at several ages. The dependent variables were markedly different from the normal distribution and could not be transformed to normality. In addition, explanatory variables were assumed to be measured with different forms of error. Illustration of how the corresponding models can be estimated conveniently via MCMC simulation, in particular, 'Gibbs sampling', using the freely available software BUGS is presented. In addition, how the measurement error may influence the estimates of the corresponding coefficients is explored. It is demonstrated that the effect of the independent variable on the dependent variable may be markedly underestimated if the measurement error is not taken into account ('regression dilution bias'). Markov chain Monte Carlo methods may be of great value to dentists in allowing analysis of data sets which exhibit a wide range of different forms of complexity.

Drivers of pCO2 dynamics in two contrasting coral reef lagoons: The influence of submarine groundwater discharge (Invited)

NASA Astrophysics Data System (ADS)

Cyronak, T.; Santos, I. R.; Erler, D.; Maher, D. T.; Eyre, B.

2013-12-01

The carbon chemistry of coral reef lagoons can be highly variable over short time scales. While much of the diel variability in seawater carbon chemistry is explained by biological processes, external sources such as river and groundwater seepage may deliver large amounts of organic and inorganic carbon to coral reefs and represent a poorly understood feedback to ocean acidification. Here, we assess the impact of submarine groundwater discharge (SGD) on pCO2 variability in two coral reef lagoons with distinct SGD driving mechanisms. Diel variability of pCO2 in the two ecosystems was explained by a combination of biological drivers and SGD inputs. In Rarotonga, a South Pacific volcanic island, SGD was driven primarily by a steep terrestrial hydraulic gradient, and the lagoon was influenced by the high pCO2 (5,501 μatm) of the fresh groundwater. In Heron Island, a Great Barrier Reef coral cay, SGD was dominated by seawater recirculation through sediments (i.e. tidal pumping) and pCO2 was mainly impacted through the stimulation of biological processes. The Rarotonga water column had a relatively higher average pCO2 (549 μatm) than Heron Island (471 μatm). However, pCO2 exhibited a greater diel range in Heron Island (778 μatm) than in Rarotonga (507 μatm). The Rarotonga lagoon received 31.2 mmol CO2 m-2 d-1 from SGD, while the Heron Island lagoon received 12.3 mmol CO2 m-2 d-1. Over the course of this study both systems were sources of CO2 to the atmosphere (3.00 to 9.67 mmol CO2 m-2 d-1), with SGD-derived CO2 contributing a large portion to the air-sea CO2 flux. The relationship between both water column pH and aragonite saturation state (ΩAr) and radon (222Rn) concentrations indicate that SGD may enhance the local acidification of some coral reef lagoons. Studies measuring the carbon chemistry of coral reefs (e.g. community metabolism, calcification rates) may need to consider SGD-derived CO2.

Survey of submesoscale structures at the margin of the Northern Current in the North Western Mediterranean Sea using Gliders: observations and diagnostics

NASA Astrophysics Data System (ADS)

Bosse, Anthony; Testor, Pierre; Mortier, Laurent; Beguery, Laurent; Bernardet, Karim; Taillandier, Vincent; d'Ortenzio, Fabrizio; Prieur, Louis; Coppola, Laurent; Bourrin, François

2013-04-01

From 2008 on, repeated sections crossing the Northern Current (NC) were operated by gliders as part of a global observing system (MOOSE project) of the North Western Mediterranean Sea. This work is dedicated to the analysis of the submesoscale thermohaline variability at the margin of this current observed by gliders. The mean circulation of the basin is characterized by a cyclonic gyre (whose Northern part is the so-called NC) associated with a doming of the isopycnals preconditionning the whole interior basin to great vertical mixing. The thermal and haline differences between the Atlantic Water (AW) transported by the NC and older and modified AW off the coast leads to a frontal structure. Especially in winter, when the mixed layer depth used to reach several hundreds of meters offshore, isopycnal outcropping and the role of frontal processes are enhanced leading to intense variability at scales smaller than the deformation radius. Based on diagnostics using the Potential Vorticity (PV) computed from the glider data assuming quasi-geostrophic conditions and no variation in the alongshore direction, we discuss the dynamical processes at work, with a focus on 2 typical examples: (1) the first example takes place in winter during a strong vertical mixing event. While the glider crossed the frontal region, the temperature and salinity fields exhibit vertical motions at depths about 0-400m. Frontogenesis might be at play through mesoscale strain since the glider shows an intense mesoscale activity but a weak stratification and enhanced horizontal buoyancy gradient actually make the Ertel PV reach negative values and symmetric instability is likely to be a prominent mechanism explaining the observed variability. (2) the second example takes place in spring. We identify an episode of down-front wind blowing during the glider deployment which could have extracted PV from the surface layer. However, the geostrophic turbulence is in that case likely to play a key role in the formation of the observed variability of the temperature and salinity since it is organized along slopes characterized by an aspect ratio of an order of f/N.

Evaluating a Local Ensemble Transform Kalman Filter snow cover data assimilation method to estimate SWE within a high-resolution hydrologic modeling framework across Western US mountainous regions

NASA Astrophysics Data System (ADS)

Oaida, C. M.; Andreadis, K.; Reager, J. T., II; Famiglietti, J. S.; Levoe, S.

2017-12-01

Accurately estimating how much snow water equivalent (SWE) is stored in mountainous regions characterized by complex terrain and snowmelt-driven hydrologic cycles is not only greatly desirable, but also a big challenge. Mountain snowpack exhibits high spatial variability across a broad range of spatial and temporal scales due to a multitude of physical and climatic factors, making it difficult to observe or estimate in its entirety. Combing remotely sensed data and high resolution hydrologic modeling through data assimilation (DA) has the potential to provide a spatially and temporally continuous SWE dataset at horizontal scales that capture sub-grid snow spatial variability and are also relevant to stakeholders such as water resource managers. Here, we present the evaluation of a new snow DA approach that uses a Local Ensemble Transform Kalman Filter (LETKF) in tandem with the Variable Infiltration Capacity macro-scale hydrologic model across the Western United States, at a daily temporal resolution, and a horizontal resolution of 1.75 km x 1.75 km. The LETKF is chosen for its relative simplicity, ease of implementation, and computational efficiency and scalability. The modeling/DA system assimilates daily MODIS Snow Covered Area and Grain Size (MODSCAG) fractional snow cover over, and has been developed to efficiently calculate SWE estimates over extended periods of time and covering large regional-scale areas at relatively high spatial resolution, ultimately producing a snow reanalysis-type dataset. Here we focus on the assessment of SWE produced by the DA scheme over several basins in California's Sierra Nevada Mountain range where Airborne Snow Observatory data is available, during the last five water years (2013-2017), which include both one of the driest and one of the wettest years. Comparison against such a spatially distributed SWE observational product provides a greater understanding of the model's ability to estimate SWE and SWE spatial variability, and highlights under which conditions snow cover DA can add value in estimating SWE.

Talking about Animals: Studies of Young Children Visiting Zoos, a Museum and a Farm.

ERIC Educational Resources Information Center

Tunnicliffe, Susan Dale

The purpose of this study was to identify the content and form of the conversations and recognize the variables that are acting during visits to animal exhibits, and the influence on conversational content of both different types of locations and animal exhibits and visit rationales. Conversations of children between the ages of 3 and 12 years and…

Factors associated with bruxism in children with developmental disabilities.

PubMed

Souza, Valeska Aparecida Fernandes; Abreu, Mauro Henrique Nogueira Guimarães; Resende, Vera Lúcia Silva; Castilho, Lia Silva

2015-01-01

The aim of the present study was to investigate factors associated with bruxism in children aged from 1 to 13 years with developmental disabilities. A total of 389 dental records were examined. The bruxism analyzed was determined based on parental reports. The following variables were also analyzed: gender, age, International Code of Diseases (ICD), mouth breathing, history of gastroesophageal reflux, use of psychotropic drugs, gingival status, reports of xerostomia, hyperkinesis, pacifier use, thumb sucking and involuntary movements. For the purposes of analysis, the individuals were categorized as being with and without bruxism. Variables with a p-value < 0.25 in the bivariate analysis were incorporated into the logistic regression models. Females had a 0.44-fold (95%CI: 0.25 to 0.78) greater chance of exhibiting bruxism than males. Individuals with gastroesophageal reflux had a 2.28-fold (95%CI: 1.03 to 5.02) greater chance of exhibiting bruxism. Individuals with reported involuntary movements had a 2.24-fold (95%CI: 1.19 to 4.24) greater chance of exhibiting bruxism than those without such movements. Exhibiting involuntary movements, the male gender and gastroesophageal reflux are factors associated with bruxism in children with developmental disabilities.

Web Access to RSIG Data

EPA Pesticide Factsheets

Remote Sensing Information Gateway, a tool that allows scientists, researchers and decision makers to access a variety of multi-terabyte, environmental datasets and to subset the data and obtain only needed variables, greatly improving the download time.

Tips for Running RSIG2D

EPA Pesticide Factsheets

Remote Sensing Information Gateway, a tool that allows scientists, researchers and decision makers to access a variety of multi-terabyte, environmental datasets and to subset the data and obtain only needed variables, greatly improving the download time.

Role of wind forcing and eddy activity in the intraseasonal variability of the barrier layer in the South China Sea

NASA Astrophysics Data System (ADS)

Liang, Zhanlin; Xie, Qiang; Zeng, Lili; Wang, Dongxiao

2018-03-01

In addition to widely discussed seasonal variability, the barrier layer (BL) of the South China Sea (SCS) also exhibits significant intraseasonal variability (ISV) and plays an important role in the upper heat and salt balances. The characteristics and mechanisms of spatiotemporal variations in the BL are investigated using an eddy-resolving ocean model OFES (OGCM For the Earth Simulator) ouput and related atmospheric and oceanic processes. The active intraseasonal BL variability in the SCS occurs mainly during the late summer/autumn and winter and exhibits remarkable differences between these two periods. The BL ISV in late summer/autumn occurs in the southern basin, while in winter, it is limited to the northwestern basin. To further discuss the evolution and driving thermodynamic mechanisms, we quantify the processes that control the variability of intraseasonal BL. Different mechanisms for the intraseasonal BL variability for these two active periods are investigated based on the case study and composite analysis. During late summer/autumn, the active BL in the southern basin is generated by advected and local freshwater, and then decays rapidly with the enhanced wind. In winter, anticyclonic eddy activity is associated with the evolution of the BL by affecting the thermocline and halocline variations, while wind stress and wind stress curl have no obvious influence on BL.

Are Droughts in the United States Great Plains Predictable on Seasonal and Longer Time Scales?

NASA Technical Reports Server (NTRS)

Schubert, Siegfried D.; Suarez, M.; Pegion, P.; Kistler, M.; Einaudi, Franco (Technical Monitor)

2001-01-01

The United States Great Plains has experienced numerous episodes of unusually dry conditions lasting anywhere from months to several years, In this presentation, we will examine the predictability of such episodes and the physical mechanisms controlling the variability of the summer climate of the continental United States. The analysis is based on ensembles of multi-year simulations and seasonal hindcasts generated with the NASA Seasonal to-Interannual Prediction Project (NSIPP-1) General Circulation Model.

Silicon waveguide with four zero-dispersion wavelengths and its application in on-chip octave-spanning supercontinuum generation.

PubMed

Zhang, Lin; Lin, Qiang; Yue, Yang; Yan, Yan; Beausoleil, Raymond G; Willner, Alan E

2012-01-16

We propose a novel silicon waveguide that exhibits four zero-dispersion wavelengths for the first time, to the best of our knowledge, with a flattened dispersion over a 670-nm bandwidth. This holds a great potential for exploration of new nonlinear effects and achievement of ultra-broadband signal processing on a silicon chip. As an example, we show that an octave-spanning supercontinuum assisted by dispersive wave generation can be obtained in silicon, over a wavelength range from 1217 to 2451 nm, almost from bandgap wavelength to half-bandgap wavelength. Input pulse is greatly compressed to 10 fs.

N, P-codoped Mesoporous Carbon Supported PtCox Nanoparticles and Their Superior Electrochemical toward Methanol Oxidation

NASA Astrophysics Data System (ADS)

Cui, Hangjun; Li, Yueming; Liu, Shimin

2018-03-01

In this report, a novel strategy by using the N, P co-doped mesoporous carbon structure as catalyst support to enhance the electrochemical catalytic activity of Pt-based catalysts is proposed. The as-synthesized PtCox@N, P-doped mesoporous carbon nanocomposties have been studied as an anode catalyst toward methanol oxidation, exhibiting greatly improved electrochemical activity and stability compared with Pt@mesoporous carbon. The synergistic effects of N, P dual-doping and porous carbon structure help to achieve better electron transport at the electrode surface, which eventually leads to greatly enhanced catalytic activity compared to the pristine Pt/mesoporous carbon.…

A High-Resolution, Three-Dimensional Model of Jupiter's Great Red Spot

NASA Technical Reports Server (NTRS)

Cho, James Y.-K.; delaTorreJuarez, Manuel; Ingersoll, Andrew P.; Dritschel, David G.

2001-01-01

The turbulent flow at the periphery of the Great Red Spot (GRS) contains many fine-scale filamentary structures, while the more quiescent core, bounded by a narrow high- velocity ring, exhibits organized, possibly counterrotating, motion. Past studies have neither been able to capture this complexity nor adequately study the effect of vertical stratification L(sub R)(zeta) on the GRS. We present results from a series of high-resolution, three-dimensional simulations that advect the dynamical tracer, potential vorticity. The detailed flow is successfully captured with a characteristic value of L(sub R) approx. equals 2000 km, independent of the precise vertical stratification profile.

Quantifying seasonal velocity at Khumbu Glacier, Nepal

NASA Astrophysics Data System (ADS)

Miles, E.; Quincey, D. J.; Miles, K.; Hubbard, B. P.; Rowan, A. V.

2017-12-01

While the low-gradient debris-covered tongues of many Himalayan glaciers exhibit low surface velocities, quantifying ice flow and its variation through time remains a key challenge for studies aimed at determining the long-term evolution of these glaciers. Recent work has suggested that glaciers in the Everest region of Nepal may show seasonal variability in surface velocity, with ice flow peaking during the summer as monsoon precipitation provides hydrological inputs and thus drives changes in subglacial drainage efficiency. However, satellite and aerial observations of glacier velocity during the monsoon are greatly limited due to cloud cover. Those that do exist do not span the period over which the most dynamic changes occur, and consequently short-term (i.e. daily) changes in flow, as well as the evolution of ice dynamics through the monsoon period, remain poorly understood. In this study, we combine field and remote (satellite image) observations to create a multi-temporal, 3D synthesis of ice deformation rates at Khumbu Glacier, Nepal, focused on the 2017 monsoon period. We first determine net annual and seasonal surface displacements for the whole glacier based on Landsat-8 (OLI) panchromatic data (15m) processed with ImGRAFT. We integrate inclinometer observations from three boreholes drilled by the EverDrill project to determine cumulative deformation at depth, providing a 3D perspective and enabling us to assess the role of basal sliding at each site. We additionally analyze high-frequency on-glacier L1 GNSS data from three sites to characterize variability within surface deformation at sub-seasonal timescales. Finally, each dataset is validated against repeat-dGPS observations at gridded points in the vicinity of the boreholes and GNSS dataloggers. These datasets complement one another to infer thermal regime across the debris-covered ablation area of the glacier, and emphasize the seasonal and spatial variability of ice deformation for glaciers in High Mountain Asia.

GALA: group analysis leads to accuracy, a novel approach for solving the inverse problem in exploratory analysis of group MEG recordings

PubMed Central

Kozunov, Vladimir V.; Ossadtchi, Alexei

2015-01-01

Although MEG/EEG signals are highly variable between subjects, they allow characterizing systematic changes of cortical activity in both space and time. Traditionally a two-step procedure is used. The first step is a transition from sensor to source space by the means of solving an ill-posed inverse problem for each subject individually. The second is mapping of cortical regions consistently active across subjects. In practice the first step often leads to a set of active cortical regions whose location and timecourses display a great amount of interindividual variability hindering the subsequent group analysis. We propose Group Analysis Leads to Accuracy (GALA)—a solution that combines the two steps into one. GALA takes advantage of individual variations of cortical geometry and sensor locations. It exploits the ensuing variability in electromagnetic forward model as a source of additional information. We assume that for different subjects functionally identical cortical regions are located in close proximity and partially overlap and their timecourses are correlated. This relaxed similarity constraint on the inverse solution can be expressed within a probabilistic framework, allowing for an iterative algorithm solving the inverse problem jointly for all subjects. A systematic simulation study showed that GALA, as compared with the standard min-norm approach, improves accuracy of true activity recovery, when accuracy is assessed both in terms of spatial proximity of the estimated and true activations and correct specification of spatial extent of the activated regions. This improvement obtained without using any noise normalization techniques for both solutions, preserved for a wide range of between-subject variations in both spatial and temporal features of regional activation. The corresponding activation timecourses exhibit significantly higher similarity across subjects. Similar results were obtained for a real MEG dataset of face-specific evoked responses. PMID:25954141

Physically-based distributed mass balance modeling of a tropical glacier: An application to backward modeling of past climate

NASA Astrophysics Data System (ADS)

Moelg, T.; Cullen, N. J.; Hardy, D. R.; Winkler, M.; Kaser, G.

2009-04-01

The use of spatially distributed (2-D) mass balance models has increased in recent years, but mostly focuses on extratropical glacier surfaces. Here we present the first application of a process-based 2-D model to an African glacier: Kersten Glacier on Kilimanjaro. Multi-year data from an automatic weather station (AWS) at 5873 m a.s.l. (500 hPa) serve to force the model. Validation variables comprise surface temperature, surface height change, snow depth, and incoming radiation - all of which indicate a good model performance. Analyses of the interannual variability in the most significant total mass budget terms (surface accumulation, melt, and sublimation), as well as in the related energy fluxes, exhibit a strong link to atmospheric moisture of a particular year. This is because net shortwave radiation (a result of both cloudiness and surface albedo) is the most variable energy flux on monthly to annual time scales. Internal accumulation (refreezing of melt water), however, shows a time lag and is strongest after a very wet year. Due to the limited validation data at lower elevations, we also perform a detailed sensitivity study by varying 17 model parameters - which yields a total mass loss estimate of 522 +/- 105 kg/m2/year under present climate conditions. Moreover, the verified model allows us to perform backward modeling of the last maximum extent of Kersten Glacier in the 1880s, which is indicated by a well preserved terminal moraine. This step reveals decreases in precipitation (30-45%), water vapor pressure (0.1-0.3 hPa) and cloud cover (2-4 percentage units) as the most likely local climate change between late 19th century and present. Thus, the study also demonstrates how 2-D modeling can help reconstruct past climate for a remote place prior to the availability of measurements. In our case these findings have great relevance for the debate of surface versus mid-tropospheric climate change in the tropics.

Variability of Jupiter's Five-Micron Hot Spot Inventory

NASA Technical Reports Server (NTRS)

Yanamandra-Fisher, Padma A.; Orton, G. S.; Wakefield, L.; Rogers, J. H.; Simon-Miller, A. A.; Boydstun, K.

2012-01-01

Global upheavals on Jupiter involve changes in the albedo of entire axisymmetric regions, lasting several years, with the last two occurring in 1989 and 2006. Against this backdrop of planetary-scale changes, discrete features such as the Great Red Spot (GRS), and other vortices exhibit changes on shorter spatial- and time-scales. We track the variability of the discrete equatorial 5-micron hot spots, semi-evenly spaced in longitude and confined to a narrow latitude band centered at 6.5degN (southern edge of the North Equatorial Belt, NEB), abundant in Voyager images. Tantalizingly similar patterns were observed in the visible (bright plumes and blue-gray regions), where reflectivity in the red is anti-correlated with 5-microns thermal radiance. Ortiz et al. (1998, GRL, 103) characterized the latitude and drift rates of the hot spots, including the descent of the Galileo probe at the southern edge of a 5-micron hot spot, as the superposition of equatorial Rossby waves, with phase speeds between 99 - 103m/s, relative to System III. We note that the high 5-micron radiances correlate well but not perfectly with high 8.57-micron radiances. Because the latter are modulated primarily by changes in the upper ammonia (NH3) ice cloud opacity, this correlation implies that changes in the ammonia ice cloud field may be responsible for the variability seen in the 5-m maps. During the NEB fade (2011 - early 2012), however, these otherwise ubiquitous features were absent, an atmospheric state not seen in decades. The ongoing NEB revival indicates nascent 5-m hot spots as early as April 2012, with corresponding visible dark spots. Their continuing growth through July 2012 indicates the possit.le re-establishment of Rossby waves. The South Equatorial Belt (SEB) and NEB revivals began similarly with an instability that developed into a major outbreak, and many similarities in the observed propagation of clear regions.

Observations of CO above Venus cloud top near 4.53 μm

NASA Astrophysics Data System (ADS)

Marcq, E.; Encrenaz, T.; Widemann, T.; Bertaux, J. L.

2013-09-01

Venus' cloud top region exhibits a higher level of variability both in space and time than previously thought. The interplay between photochemistry, dynamics and cloud microphysics requires more observational constraints in order to be fully grasped. Recent observations of sulfur dioxide (SO2) variability [2, 8, 7, 9] have evidenced both short-term, longterm and latitudinal variability whose origin remains mysterious (volcanogenic emissions? dynamic variability?). A better knowledge of the variability of other minor species would be highly welcome in this context. Carbon monoxide (CO), whose pattern of sinks and sources is opposite to SO2, is a prime candidate.

Photometric Variability of the Be Star Population

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

Labadie-Bartz, Jonathan; Pepper, Joshua; McSwain, M. Virginia

2017-06-01

Be stars have generally been characterized by the emission lines in their spectra, and especially the time variability of those spectroscopic features. They are known to also exhibit photometric variability at multiple timescales, but have not been broadly compared and analyzed by that behavior. We have taken advantage of the advent of wide-field, long-baseline, and high-cadence photometric surveys that search for transiting exoplanets to perform a comprehensive analysis of brightness variations among a large number of known Be stars. The photometric data comes from the KELT transit survey, with a typical cadence of 30 minutes, a baseline of up to 10more » years, photometric precision of about 1%, and coverage of about 60% of the sky. We analyze KELT light curves of 610 known Be stars in both the northern and southern hemispheres in an effort to study their variability. Consistent with other studies of Be star variability, we find most of the stars to be photometrically variable. We derive lower limits on the fraction of stars in our sample that exhibit features consistent with non-radial pulsations (25%), outbursts (36%), and long-term trends in the circumstellar disk (37%), and show how these are correlated with spectral sub-types. Other types of variability, such as those owing to binarity, are also explored. Simultaneous spectroscopy for some of these systems from the Be Star Spectra database allow us to better understand the physical causes for the observed variability, especially in cases of outbursts and changes in the disk.« less

Marsh dieback, loss, and recovery mapped with satellite optical, airborne polarimetric radar, and field data

USGS Publications Warehouse

Ramsey, Elijah W.; Rangoonwala, Amina; Chi, Zhaohui; Jones, Cathleen E.; Bannister, Terri

2014-01-01

Landsat Thematic Mapper and Satellite Pour l'Observation de la Terre (SPOT) satellite based optical sensors, NASA Uninhabited Aerial Vehicle synthetic aperture radar (UAVSAR) polarimetric SAR (PolSAR), and field data captured the occurrence and the recovery of an undetected dieback that occurred between the summers of 2010, 2011, and 2012 in the Spartina alterniflora marshes of coastal Louisiana. Field measurements recorded the dramatic biomass decrease from 2010 to 2011 and a biomass recovery in 2012 dominated by a decrease of live biomass, and the loss of marsh as part of the dieback event. Based on an established relationship, the near-infrared/red vegetation index (VI) and site-specific measurements delineated a contiguous expanse of marsh dieback encompassing 6649.9 ha of 18,292.3 ha of S. alterniflora marshes within the study region. PolSAR data were transformed to variables used in biophysical mapping, and of this variable suite, the cross-polarization HV (horizontal send and vertical receive) backscatter was the best single indicator of marsh dieback and recovery. HV backscatter exhibited substantial and significant changes over the dieback and recovery period, tracked measured biomass changes, and significantly correlated with the live/dead biomass ratio. Within the context of regional trends, both HV and VI indicators started higher in pre-dieback marshes and exhibited substantially and statistically higher variability from year to year than that exhibited in the non-dieback marshes. That distinct difference allowed the capturing of the S. alterniflora marsh dieback and recovery; however, these changes were incorporated in a regional trend exhibiting similar but more subtle biomass composition changes.

Exact extreme-value statistics at mixed-order transitions.

PubMed

Bar, Amir; Majumdar, Satya N; Schehr, Grégory; Mukamel, David

2016-05-01

We study extreme-value statistics for spatially extended models exhibiting mixed-order phase transitions (MOT). These are phase transitions that exhibit features common to both first-order (discontinuity of the order parameter) and second-order (diverging correlation length) transitions. We consider here the truncated inverse distance squared Ising model, which is a prototypical model exhibiting MOT, and study analytically the extreme-value statistics of the domain lengths The lengths of the domains are identically distributed random variables except for the global constraint that their sum equals the total system size L. In addition, the number of such domains is also a fluctuating variable, and not fixed. In the paramagnetic phase, we show that the distribution of the largest domain length l_{max} converges, in the large L limit, to a Gumbel distribution. However, at the critical point (for a certain range of parameters) and in the ferromagnetic phase, we show that the fluctuations of l_{max} are governed by novel distributions, which we compute exactly. Our main analytical results are verified by numerical simulations.

Cheap, High-Performance, and Wearable Mn Oxide Supercapacitors with Urea-LiClO4 Based Gel Electrolytes.

PubMed

Deng, Ming-Jay; Chen, Kai-Wen; Che, Yo-Cheng; Wang, I-Ju; Lin, Chih-Ming; Chen, Jin-Ming; Lu, Kueih-Tzu; Liao, Yen-Fa; Ishii, Hirofumi

2017-01-11

Here we report a simple, scalable, and low-cost method to enhance the electrochemical properties of Mn oxide electrodes for highly efficient and flexible symmetrical supercapacitors. The method involving printing on a printer, pencil-drawing, and electrodeposition is established to fabricate Mn oxide/Ni-nanotube/graphite/paper hybrid electrodes operating with a low-cost, novel urea-LiClO 4 /PVA as gel electrolyte for flexible solid-state supercapacitor (FSSC) devices. The Mn oxide nanofiber/Ni-nanotube/graphite/paper (MNNGP) electrodes in urea-LiClO 4 /PVA gel electrolyte show specific capacitance (C sp ) 960 F/g in voltage region 0.8 V at 5 mV/s and exhibit excellent rates of capacitance retention more than 85% after 5000 cycles. Moreover, the electrochemical behavior of the MNNGP electrodes in urea-LiClO 4 /PVA at operating temperatures 27-110 °C was investigated; the results show that the MNNGP electrodes in urea-LiClO 4 /PVA exhibit outstanding performance (1100 F/g), even at 90 °C. The assembled FSSC devices based on the MNNGP electrodes in urea-LiClO 4 /PVA exhibit great C sp (380 F/g in potential region of 2.0 V at 5 mV/s, exhibiting superior energy density 211.1 W h/kg) and great cycle stability (less than 15% loss after 5000 cycles at 25 mV/s). The oxidation-state change was examined by in situ X-ray absorption spectroscopy. FSSC devices would open new opportunities in developing novel portable, wearable, and roll-up electric devices owing to the cheap, high-performance, wide range of operating temperature, and simple procedures for large-area fabrication.

Quantifying mental foramen position in extant hominoids and Australopithecus: implications for its use in studies of human evolution.

PubMed

Robinson, Chris A; Williams, Frank L

2010-08-01

The location of the mental foramen on the mandibular corpus has figured prominently in debates concerning the taxonomy of fossil hominins and Gorilla gorilla. In this study we quantify the antero/posterior (A/P) position of the mental foramen across great apes, modern humans and Australopithecus. Contrary to most qualitative assessments, we find significant differences between some extant hominoid species in mental foramen A/P position supporting its potential usefulness as a character for taxonomic and phylogenetic analyses of fossil hominoids. Gorilla gorilla, particularly the eastern subspecies, with a comparatively longer dental arcade and fossil and extant hominins with reduced canines and incisors tend to exhibit more anteriorly positioned mental foramina. Conversely, Pan troglodytes exhibits more posteriorly positioned mental foramina. Variation in this character among Gorilla gorilla subspecies supports recent taxonomic assessments that separate eastern and western populations. In all taxa other than Pan troglodytes the A/P position of the mental foramen is positively allometric with respect to dental arcade length. Thus, within each of these species, specimens with longer dental arcades tend to have more posteriorly positioned mental foramina. Those species with greater sexual dimorphism in canine size and dental arcade length (i.e., Gorilla gorilla and Pongo pygmaeus) exhibit more extreme differences between smaller and larger individuals. Moreover, among great apes those individuals with greater anterior convergence of the dental arcade tend to exhibit more posteriorly positioned mental foramina. Dental arcade length, canine crown area and anterior convergence are all significantly associated with mental foramen A/P position, suggesting that these traits may influence taxonomic variation in the A/P position of the mental foramen. (c) 2010 Wiley-Liss, Inc.

Facile and cost effective synthesis of mesoporous spinel NiCo2O4 as an anode for high lithium storage capacity

NASA Astrophysics Data System (ADS)

Jadhav, Harsharaj S.; Kalubarme, Ramchandra S.; Park, Choong-Nyeon; Kim, Jaekook; Park, Chan-Jin

2014-08-01

To fulfill the high power and high energy density demands for Li-ion batteries (LIBs) new anode materials need to be explored to replace conventional graphite. Herein, we report the urea assisted facile co-precipitation synthesis of spinel NiCo2O4 and its application as an anode material for LIBs. The synthesized NiCo2O4 exhibited an urchin-like microstructure and polycrystalline and mesoporous nature. In addition, the mesoporous NiCo2O4 electrode exhibited an initial discharge capacity of 1095 mA h g-1 and maintained a reversible capacity of 1000 mA h g-1 for 400 cycles at 0.5 C-rate. The reversible capacity of NiCo2O4 could still be maintained at 718 mA h g-1, even at 10 C. The mesoporous NiCo2O4 exhibits great potential as an anode material for LIBs with the advantages of unique performance and facile preparation.To fulfill the high power and high energy density demands for Li-ion batteries (LIBs) new anode materials need to be explored to replace conventional graphite. Herein, we report the urea assisted facile co-precipitation synthesis of spinel NiCo2O4 and its application as an anode material for LIBs. The synthesized NiCo2O4 exhibited an urchin-like microstructure and polycrystalline and mesoporous nature. In addition, the mesoporous NiCo2O4 electrode exhibited an initial discharge capacity of 1095 mA h g-1 and maintained a reversible capacity of 1000 mA h g-1 for 400 cycles at 0.5 C-rate. The reversible capacity of NiCo2O4 could still be maintained at 718 mA h g-1, even at 10 C. The mesoporous NiCo2O4 exhibits great potential as an anode material for LIBs with the advantages of unique performance and facile preparation. Electronic supplementary information (ESI) available: Experimental details and additional experimental results. See DOI: 10.1039/c4nr02183e

The Great Emch Closure Theorem and a combinatorial proof of Poncelet's Theorem

NASA Astrophysics Data System (ADS)

Avksentyev, E. A.

2015-11-01

The relations between the classical closure theorems (Poncelet's, Steiner's, Emch's, and the zigzag theorems) and some of their generalizations are discussed. It is known that Emch's Theorem is the most general of these, while the others follow as special cases. A generalization of Emch's Theorem to pencils of circles is proved, which (by analogy with the Great Poncelet Theorem) can be called the Great Emch Theorem. It is shown that the Great Emch and Great Poncelet Theorems are equivalent and can be derived one from the other using elementary geometry, and also that both hold in the Lobachevsky plane as well. A new closure theorem is also obtained, in which the construction of closure is slightly more involved: closure occurs on a variable circle which is tangent to a fixed pair of circles. In conclusion, a combinatorial proof of Poncelet's Theorem is given, which deduces the closure principle for an arbitrary number of steps from the principle for three steps using combinatorics and number theory. Bibliography: 20 titles.

Quantifying Landscape Spatial Pattern: What Is the State of the Art?

Treesearch

Eric J. Gustafson

1998-01-01

Landscape ecology is based on the premise that there are strong links between ecological pattern and ecological function and process. Ecological systems are spatially heterogeneous, exhibiting consid-erable complexity and variability in time and space. This variability is typically represented by categorical maps or by a collection of samples taken at specific spatial...

Environmental Fluctuations and Acoustic Data Communications

DTIC Science & Technology

2015-09-30

July 2011 along with subsequent analysis of the experiment data. KAM11 Experiment (2011) A shallow water acoustic communications experiment...packet and packet-to-packet variability. Algorithm Design and Experiment Data Analysis Communication receiver algorithm design for shallow water is...exhibited substantial daily oceanographic variability. Analysis of the KAM11 experiment data this past year has focused on fixed source transmissions

Using the Contextual Model of Learning to Understand Visitor Learning from a Science Center Exhibition

ERIC Educational Resources Information Center

Falk, John; Storksdieck, Martin

2005-01-01

Falk and Dierking's Contextual Model of Learning was used as a theoretical construct for investigating learning within a free-choice setting. A review of previous research identified key variables fundamental to free-choice science learning. The study sought to answer two questions: (1) How do specific independent variables individually contribute…

Factors influencing spatial variability in nitrogen processing in nitrogen-saturated soils

Treesearch

Frank S. Gilliam; Charles C. Somerville; Nikki L. Lyttle; Mary Beth Adams

2001-01-01

Nitrogen (N) saturation is an environmental concern for forests in the eastern U.S. Although several watersheds of the Fernow Experimental Forest (FEF), West Virginia exhibit symptoms of N saturation, many watersheds display a high degree of spatial variability in soil N processing. This study examined the effects of temperature on net N mineralization and...

LES/PDF studies of joint statistics of mixture fraction and progress variable in piloted methane jet flames with inhomogeneous inlet flows

NASA Astrophysics Data System (ADS)

Zhang, Pei; Barlow, Robert; Masri, Assaad; Wang, Haifeng

2016-11-01

The mixture fraction and progress variable are often used as independent variables for describing turbulent premixed and non-premixed flames. There is a growing interest in using these two variables for describing partially premixed flames. The joint statistical distribution of the mixture fraction and progress variable is of great interest in developing models for partially premixed flames. In this work, we conduct predictive studies of the joint statistics of mixture fraction and progress variable in a series of piloted methane jet flames with inhomogeneous inlet flows. The employed models combine large eddy simulations with the Monte Carlo probability density function (PDF) method. The joint PDFs and marginal PDFs are examined in detail by comparing the model predictions and the measurements. Different presumed shapes of the joint PDFs are also evaluated.

Beyond logistic regression: structural equations modelling for binary variables and its application to investigating unobserved confounders.

PubMed

Kupek, Emil

2006-03-15

Structural equation modelling (SEM) has been increasingly used in medical statistics for solving a system of related regression equations. However, a great obstacle for its wider use has been its difficulty in handling categorical variables within the framework of generalised linear models. A large data set with a known structure among two related outcomes and three independent variables was generated to investigate the use of Yule's transformation of odds ratio (OR) into Q-metric by (OR-1)/(OR+1) to approximate Pearson's correlation coefficients between binary variables whose covariance structure can be further analysed by SEM. Percent of correctly classified events and non-events was compared with the classification obtained by logistic regression. The performance of SEM based on Q-metric was also checked on a small (N = 100) random sample of the data generated and on a real data set. SEM successfully recovered the generated model structure. SEM of real data suggested a significant influence of a latent confounding variable which would have not been detectable by standard logistic regression. SEM classification performance was broadly similar to that of the logistic regression. The analysis of binary data can be greatly enhanced by Yule's transformation of odds ratios into estimated correlation matrix that can be further analysed by SEM. The interpretation of results is aided by expressing them as odds ratios which are the most frequently used measure of effect in medical statistics.