723 research outputs found
West Nile Virus and Wildlife Health
The West Nile Virus and Wildlife Health Workshop, hosted by the Smithsonian Institution, National Audubon Society, U.S. Geological Survey, and U.S. Department of Agriculture, was held February 5–7, 2003, at the Smithsonian Environmental Research Center in Edgewater, Maryland. The event was attended by more than 100 scientists, who heard 29 speakers and participated in strategy discussions during the 2-day meeting. The main focus of the conference was the present and future impact of West Nile virus on wildlife populations. Talks and discussions emphasized how basic research, public health, and land management can contribute to our understanding of the disease’s impact and spread. A primary objective of this meeting was to develop future research priorities from both basic and applied perspectives. The conference centered around four main themes: 1) host, vector, and pathogen interactions (disease ecology); 2) vertebrate behavior and ecology; 3) vector behavior and ecology; and 4) modeling and spatial statistics. We describe some of the findings from the meeting. For an in-depth summary of this meeting, please visit the conference website for meeting abstracts and a downloadable conference white paper (available from: URL: www.serc.si.edu/migratorybirds/ migratorybirds_index.htm)
Homogeneous nucleation and growth of silicon powder from laser heated gas phase reactants
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1983.MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCEVita.Includes bibliographical references.by Robert A. Marra.Ph.D
Upwelling and convergence in the Middle Atlantic Bight shelfbreak front
Convergent and upwelling circulation within the shelfbreak front in the Middle Atlantic Eight are detected using a dye tracer injected into the bottom boundary layer at the foot of the front. From the three day displacement and dispersion of two dye injections within the front we infer Lagrangian isopycnal (diapycnal) velocities and diffusivities of 2 x 10(-2) m/s (4 x 10(-6) m/s) and 9 m(2)/s (6 x 10(-6) m(2)/s). These results substantiate model predictions of Chapman and Lentz [1994] and previous dye tracer observations by Houghton [1997]
Characterizing avian survival along a rural-to-urban land use gradient
Many avian species persist in human-dominated landscapes; however, little is known about the demographic consequences of urbanization in these populations. Given that urban habitats introduce novel benefits (e.g., anthropogenic resources) and pressures (e.g., mortality risks), conflicting mechanisms have been hypothesized to drive the dynamics of urban bird populations. Top-down processes such as predation predict reduced survivorship in suburban and urban habitats, whereas bottom-up processes, such as increased resource availability, predict peak survival in suburban habitats. In this study, we use mark–recapture data of seven focal species encountered between 2000 and 2012 to test hypotheses about the processes that regulate avian survival along an urbanization gradient in greater Washington, D.C., USA. American Robin, Gray Catbird, Northern Cardinal, and Song Sparrow exhibited peak survival at intermediate and upper portions of the rural-to-urban gradient; this pattern supports the hypothesis that bottom-up processes (e.g., resource availability) can drive patterns of avian survival in some species. In contrast, Carolina Chickadee showed no response and Carolina and House Wren showed a slightly negative response to urban land cover. These contrasting results underscore the need for comparative studies documenting the mechanisms that drive demography and how those factors differentially affect urban adapted and urban avoiding species
Ultrasound-detected subclinical inflammation was better reflected by the disease activity score (DAS-28) in patients with suspicion of inflammatory arthritis compared to established rheumatoid arthritis
Limited data are available about the ultrasound (US)-detected inflammatory features in patients with suspicion of inflammatory arthritis (S-IA) vs. established rheumatoid arthritis (RA). Our study aimed to assess if the presence of power Doppler (PD) can be predicted by a combination of clinical, laboratory and US parameters. We conducted a real-life, retrospective cohort study comparing clinical, laboratory and US parameters of 108 patients with established RA and 93 patients with S-IA. We propose a PD signal prediction model based on a beta-binomial distribution for PD variable using a mix of outcome measures. Patients with RA in clinical remission had significantly more active inflammation and erosions on US when compared with patients with S-IA with similar disease scores (p = 0.03 and p = 0.01, respectively); however, RA patients with different disease activity score (DAS-28) scores had similar PD scores (p = 0.058). The PD scores did not correlate with erosions (p = 0.38) or DAS-28 scores (p = 0.28) in RA patients, but they correlated with high disease activity in S-IA patients (p = 0.048). Subclinical inflammation is more common in patients with RA in clinical remission or with low disease activity than in patients with S-IA; therefore, US was more useful in assessing for true remission in RA rather than diagnosing IA in patients with low disease activity scores. This is the first study to propose a PD prediction model integrating several outcome measures in the two different groups of patients. Further research into validating this model can minimise the risk of underdiagnosing subclinical inflammation
Lazer Antes e Durante e Trabalho Docente Durante a Pandemia de Covid-19
Este estudo investiga o impacto da pandemia nas experiências de lazer de professores universitários. Mediante uma abordagem qualitativa, foram coletados dados de 589 professores universitários por meio de questionários online, permitindo uma compreensão aprofundada dos desafios enfrentados. Os resultados destacam a dificuldade de conciliar as demandas profissionais com as obrigações familiares, afetando as atividades de lazer. A interação entre o ambiente doméstico e as atividades diárias limitou as oportunidades de vivenciar o lazer diversificado em diferentes espaços. A análise revelou a importância do lazer para o bem-estar dos professores, reforçando a necessidade de políticas de apoio. É relevante repensar práticas de lazer e estratégias de adaptação, especialmente diante do contexto pós-pandemia
Phytoplankton bloom phenomena in the North Atlantic Ocean and Arabian Sea
Author Posting. © The Author(s), 2014. This is the author's version of the work. It is posted here by permission of International Council for the Exploration of the Sea for personal use, not for redistribution. The definitive version was published in ICES Journal of Marine Science 72 (2015): 2021-2028, doi:10.1093/icesjms/fsu241.We review bio-optical and physical data from three mooring experiments, the Marine Light–Mixed Layers programme in spring 1989 and 1991 in the Iceland Basin (59°N/21°W), and the Forced Upper Ocean Dynamics Experiment in the central Arabian Sea from October 1994 to 1995 (15.5°N/61.5°E). In the Iceland Basin, from mid-April to mid-June in 1989, chlorophyll-a concentrations are sensitive to small changes in stratification, with intermittent increases early in the record. The spring increase occurs after 20 May, coincident with persistent water column stratification. In 1991, the bloom occurs 2 weeks earlier than in 1989, with a background of strong short-term and diurnal variability in mixed layer depth and minimal horizontal advection. In the Arabian Sea, the mixing response to the northeast and southwest monsoons, plus the response to mesoscale eddies, produces four blooms over the annual cycle. The mixed layer depth in the Arabian Sea never exceeds the euphotic zone, allowing interactions between phytoplankton and grazer populations to become important. For all three mooring experiments, change in water column stratification is key in producing phytoplankton blooms.2016-01-0
Precision Farming by Cotton Producers in Six Southern States: Results from the 2001 Southern Precision Farming Survey
Precision Farming by Cotton Producers in Six Southern States: Results from the 2001 Southern Precision Farming Surveycotton, precision farming, survey, Agribusiness, Farm Management, Production Economics, Research and Development/Tech Change/Emerging Technologies,
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Soil arthropod responses to different patch types in a mixed-conifer forest of the Sierra Nevada
The Teakettle Ecosystem Experiment in the southern Sierra Nevada is using thinning and prescribed
fire to recreate historical stand conditions. As part of Teakettle we assessed pretreatment diversity and density
of the soil arthropod community in 1998 and 2000. We determined the density and diversity of soil microarthropods
among treatment plots, the influence of patch type (closed canopy, canopy gaps, Ceanothus sp., and
coarse woody debris [CWD]), and established baseline pretreatment data. Mites were the dominant microinvertebrates
(78%). Canopy gaps had the lowest mite density and diversity, and were more sensitive to
year-to-year changes in climate (1998 was an extremely wet year for the region). Soil organic matter as
represented by bulk density appeared to be most closely associated with changes in species composition among
different patch types. There was substantial overlap, however, in community composition among the different
patch types as represented by nonmetric multidimensional scaling (NMS) ordination. No significant differences
were observed for mite species richness and density among plots assigned to future treatments. The gap data
suggest that in the characteristically hot, dry summers of the southern Sierra Nevada the rate of recovery of
vegetation following thinning and fire treatments may have a significant influence on the recovery rate of
microarthropods, not only by providing sources of energy inputs in the form of dead organic matter, but also by
moderating the microclimate of the forest floor.Keywords: Mites, Pretreatment data, Soil invertebrates, Teakettle projec
Identification of novel androgen-responsive genes by sequencing of LongSAGE libraries
<p>Abstract</p> <p>Background</p> <p>The development and maintenance of the prostate is dependent on androgens and the androgen receptor. The androgen pathway continues to be important in prostate cancer. Here, we evaluated the transcriptome of prostate cancer cells in response to androgen using long serial analysis of gene expression (LongSAGE) libraries.</p> <p>Results</p> <p>There were 131 tags (87 genes) that displayed statistically significant (p ≤ 0.001) differences in expression in response to androgen. Many of the genes identified by LongSAGE (35/87) have not been previously reported to change expression in the direction or sense observed. In regulatory regions of the promoter and/or enhancer regions of some of these genes there are confirmed or potential androgen response elements (AREs). The expression trends of 24 novel genes were validated using quantitative real time-polymerase chain reaction (qRT-PCR). These genes were: <it>ARL6IP5, BLVRB, C19orf48, C1orf122, C6orf66, CAMK2N1, CCNI, DERA, ERRFI1, GLUL, GOLPH3, HM13, HSP90B1, MANEA, NANS, NIPSNAP3A, SLC41A1, SOD1, SVIP, TAOK3, TCP1, TMEM66, USP33</it>, and <it>VTA1</it>. The physiological relevance of these expression trends was evaluated <it>in vivo </it>using the LNCaP Hollow Fibre model. Novel androgen-responsive genes identified here participate in protein synthesis and trafficking, response to oxidative stress, transcription, proliferation, apoptosis, and differentiation.</p> <p>Conclusion</p> <p>These processes may represent the molecular mechanisms of androgen-dependency of the prostate. Genes that participate in these pathways may be targets for therapies or biomarkers of prostate cancer.</p
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