155 research outputs found

    Peristaltic Transport of Couple Stress fluids In a Uniform and Non-Uniform Annulus

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    The aim of the present investigation is to study the peristaltic transport through the gap between coaxial tubes, where the outer tube is non uniform and the inner tube is rigid. The necessary theoretical results such as viscosity, pressure gradient and friction force on the inner and outer tubes have been obtained in terms of couple stress parameter. Out of these theoretical results the numerical solution of pressure gradient, outer friction, inert friction and flow rate are shown graphically for the better understanding of the problem

    Antigen-dependent Proliferation of CD4+ CD25+ Regulatory T Cells In Vivo

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    The failure of CD25+ regulatory T cells (Tregs) to proliferate after T cell receptor (TCR) stimulation in vitro has lead to their classification as naturally anergic. Here we use Tregs expressing a transgenic TCR to show that despite anergy in vitro, Tregs proliferate in response to immunization in vivo. Tregs also proliferate and accumulate locally in response to transgenically expressed tissue antigen whereas their CD25− counterparts are depleted at such sites. Collectively, these data suggest that the anergic state that characterizes CD25+ Tregs in vitro may not accurately reflect their responsiveness in vivo. These observations support a model in which Treg population dynamics are shaped by the local antigenic environment

    Cooperative Roles of CTLA-4 and Regulatory T Cells in Tolerance to an Islet Cell Antigen

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    Adoptive transfer of ovalbumin (OVA)-specific T cells from the DO.11 TCR transgenic mouse on a Rag−/− background into mice expressing OVA in pancreatic islet cells induces acute insulitis and diabetes only if endogenous lymphocytes, including regulatory T cells, are removed. When wild-type OVA-specific/Rag−/− T cells, which are all CD25−, are transferred into islet antigen–expressing mice, peripheral immunization with OVA in adjuvant is needed to induce diabetes. In contrast, naive CTLA-4−/−/Rag−/− OVA-specific T cells (also CD25−) develop into Th1 effectors and induce disease upon recognition of the self-antigen alone. These results suggest that CTLA-4 functions to increase the activation threshold of autoreactive T cells, because in its absence self-antigen is sufficient to trigger autoimmunity without peripheral immunization. Further, CTLA-4 and regulatory T cells act cooperatively to maintain tolerance, indicating that the function of CTLA-4 is independent of regulatory cells, and deficiency of both is required to induce pathologic immune responses against the islet self-antigen

    Effect of maternal yeast feeding on dam performance and serum health biomarkers of Beetal goat kids

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    Supplementation with dietary yeast has improved digestibility and productive performance in ruminants. In this research the primary objective was to appraise the effects of dietary yeast supplementation of female goats during the transition period on milk composition and yield and on production and serum health biomarkers of their kids. Twenty-four Beetal goats (4 ± 1.2 years) were randomly assigned to three groups, which received 0, 5, and 10 grams/animal/day of live dried yeast Saccharomyces cerevisiae for 60 days (30 days pre- and post-partum). All goats were fed 500 grams of concentrate with water and green fodder ad libitum. Milk samples were collected at 7, 14, 21, and 28 days post kidding. Kids were weighed on days 0, 7, 15, 22, and 30, and blood samples were collected on days 15 and 30 for serum metabolites (glucose, urea, cholesterol, non-esterified fatty acids (NEFA), serum total proteins, albumin, globulin, albumin to globulin ratio, serum oxidant and antioxidant activity (malondialdehyde) (MDA) and catalase), and liver enzymes aspartate aminotransferase (AST) and alanine transaminase (ALT) assessment. Milk yield was significantly (P =0.02) higher during the post-partum period in yeast-fed goats. Yeast-fed goats also produced milk containing more fat (P <0.001) and protein (P <0.001) compared with control goats. Birth weight, average daily gain, and serum health biomarkers of the kids were not influenced by the treatments. In conclusion, dietary yeast supplementation resulted in increased production performance of the dams without significant impact on their offspring.Keywords: average daily gain, catalase activity, hepatic enzymes, milk production, Saccharomyces cerevisiae, transition perio

    NPARSEC : NTT Parallaxes of Southern Extremely Cool objects. Goals, targets, procedures and first results

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    The discovery and subsequent detailed study of T dwarfs have provided many surprises and pushed the physics and modelling of cool atmospheres in unpredicted directions. Distance is a critical parameter for studies of these objects to determine intrinsic luminosities, test binarity and measure their motion in the Galaxy. We describe a new observational programme to determine distances across the full range of T-dwarf subtypes using the New Technology Telescope (NTT)/SOFI telescope/instrument combination. We present preliminary results for ten objects, five of which represent new distances.Peer reviewe

    Quality control for the first large areas of triple-GEM chambers for the CMS endcaps

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    The CMS Collaboration plans to equip the very forward muon system with triple-GEM detectors that can withstand the environment of the High-Luminosity LHC.This project is at the final stages of R&D and moving to production. A large area of several 100 m 2 are to be instrumented with GEM detectors which will be produced in six different sites around the world. A common construction and quality control procedure is required to ensure the performance of each detector.The quality control steps will include optical inspection,cleaning and baking of all materials and parts used to build the detector,leakage current tests of the GEM foils,high voltage tests,gas leak tests of the chambers and monitoring pressures time,gain calibration to know the optimal operation region of the detector,gain uniformity tests, and studying the efficiency,noise and tracking performance of the detectors in a cosmic stand using scintillator

    SARS-CoV-2 vaccination modelling for safe surgery to save lives: data from an international prospective cohort study

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    Background Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. Methods The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18–49, 50–69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. Results NNVs were more favourable in surgical patients than the general population. The most favourable NNVs were in patients aged 70 years or more needing cancer surgery (351; best case 196, worst case 816) or non-cancer surgery (733; best case 407, worst case 1664). Both exceeded the NNV in the general population (1840; best case 1196, worst case 3066). NNVs for surgical patients remained favourable at a range of SARS-CoV-2 incidence rates in sensitivity analysis modelling. Globally, prioritizing preoperative vaccination of patients needing elective surgery ahead of the general population could prevent an additional 58 687 (best case 115 007, worst case 20 177) COVID-19-related deaths in 1 year. Conclusion As global roll out of SARS-CoV-2 vaccination proceeds, patients needing elective surgery should be prioritized ahead of the general population

    Mapping subnational HIV mortality in six Latin American countries with incomplete vital registration systems

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    BackgroundHuman immunodeficiency virus (HIV) remains a public health priority in Latin America. While the burden of HIV is historically concentrated in urban areas and high-risk groups, subnational estimates that cover multiple countries and years are missing. This paucity is partially due to incomplete vital registration (VR) systems and statistical challenges related to estimating mortality rates in areas with low numbers of HIV deaths. In this analysis, we address this gap and provide novel estimates of the HIV mortality rate and the number of HIV deaths by age group, sex, and municipality in Brazil, Colombia, Costa Rica, Ecuador, Guatemala, and Mexico.MethodsWe performed an ecological study using VR data ranging from 2000 to 2017, dependent on individual country data availability. We modeled HIV mortality using a Bayesian spatially explicit mixed-effects regression model that incorporates prior information on VR completeness. We calibrated our results to the Global Burden of Disease Study 2017.ResultsAll countries displayed over a 40-fold difference in HIV mortality between municipalities with the highest and lowest age-standardized HIV mortality rate in the last year of study for men, and over a 20-fold difference for women. Despite decreases in national HIV mortality in all countries-apart from Ecuador-across the period of study, we found broad variation in relative changes in HIV mortality at the municipality level and increasing relative inequality over time in all countries. In all six countries included in this analysis, 50% or more HIV deaths were concentrated in fewer than 10% of municipalities in the latest year of study. In addition, national age patterns reflected shifts in mortality to older age groups-the median age group among decedents ranged from 30 to 45years of age at the municipality level in Brazil, Colombia, and Mexico in 2017.ConclusionsOur subnational estimates of HIV mortality revealed significant spatial variation and diverging local trends in HIV mortality over time and by age. This analysis provides a framework for incorporating data and uncertainty from incomplete VR systems and can help guide more geographically precise public health intervention to support HIV-related care and reduce HIV-related deaths.Peer reviewe

    Centrality Dependence Of The Pseudorapidity Density Distribution For Charged Particles In Pb-pb Collisions At √snn=2.76tev

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