441 research outputs found

    A Step Closer to Meeting the Threat of Avian Influenza

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    Schultz-Cherry discusses a new study that describes the generation of live, attenuated H5N1 influenza viruses that may be suitable candidates for use in humans

    Production of Electron Neutrinos at Nuclear Power Reactors and the Prospects for Neutrino Physics

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    High flux of electron neutrinos(\nue) is produced at nuclear power reactors through the decays of nuclei activated by neutron capture. Realistic simulation studies on the neutron transport and capture at the reactor core were performed. The production of \chr51 and \fe55 give rise to mono-energetic \nue's at Q-values of 753 keV and 231 keV and fluxes of 8.3×1048.3 \times 10^{-4} and 3.0×1043.0 \times 10^{-4} \nue/fission, respectively. Using data from a germanium detector at the Kuo-Sheng Power Plant, we derived direct limits on the \nue magnetic moment and the radiative lifetime of \mu_{\nu} < 1.3 \times 10^{-8} ~ \mub and τν/mν>0.11s/eV\rm{\tau_{\nu} / m_{\nu} > 0.11 s / eV} at 90% confidence level (CL), respectively. Indirect bounds on τν/mν3\rm{\tau_{\nu} / m_{\nu}^3} were also inferred. The \nue-flux can be enhanced by loading selected isotopes to the reactor core, and the potential applications and achievable statistical accuracies were examined. These include accurate cross-section measurements, studies of mixing angle θ13\theta_{13} and monitoring of plutonium production.Comment: 5 pages, 3 figures, 7 table

    Subtidal salinity and velocity in the Hudson River estuary : observations and modeling

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    Author Posting. © American Meteorological Society, 2008. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 38 (2008): 753-770, doi:10.1175/2007JPO3808.1.A tidally and cross-sectionally averaged model based on the temporal evolution of the quasi-steady Hansen and Rattray equations is applied to simulate the salinity distribution and vertical exchange flow along the Hudson River estuary. The model achieves high skill at hindcasting salinity and residual velocity variation during a 110-day period in 2004 covering a wide range of river discharges and tidal forcing. The approach is based on an existing model framework that has been modified to improve model skill relative to observations. The external forcing has been modified to capture meteorological time-scale variability in salinity, stratification, and residual velocity due to sea level fluctuations at the open boundary and along-estuary wind stress. To reflect changes in vertical mixing due to stratification, the vertical mixing coefficients have been modified to use the bottom boundary layer height rather than the water depth as an effective mixing length scale. The boundary layer parameterization depends on the tidal amplitude and the local baroclinic pressure gradient through the longitudinal Richardson number, and improves the model response to spring–neap variability in tidal amplitude during periods of high river discharge. Finally, steady-state model solutions are evaluated for both the Hudson River and northern San Francisco Bay over a range of forcing conditions. Agreement between the model and scaling of equilibrium salinity intrusions lends confidence that the approach is transferable to other estuaries, despite significant differences in bathymetry. Discrepancies between the model results and observations at high river discharge are indicative of limits at which the formulation begins to fail, and where an alternative approach that captures two-layer dynamics would be more appropriate.This research was supported by the Hudson River Foundation Grant 005/03A, NSF Grant OCE-0452054, and by the Postdoctoral Scholar Program at the Woods Hole Oceanographic Institution, with funding provided by the J. Seward Johnson Fund

    Assessment of information resources for people with hypodontia

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    Aim: To assess the adequacy of patient information to support understanding and decision-making for people affected by hypodontia. Methods: 1) Questionnaire to understand the provision of patient information by dentists; 2) Systematic search to identify online open-access patient information; 3) Quality assessment of written patient information. Results: Questionnaire response rate was 49% (319/649); 91% examined and/or treated people with hypodontia. Most general dentists referred patients to specialist services without providing written hypodontia information. The majority of dental specialists provide patient leaflets but less than a third used web-resources. Only 19% of respondents felt current resources were fit-for-purpose. Thirty-one patient resources (18 leaflets and 13 online) were assessed against quality criteria. The aim of the resource was seldom explicit, the content was often incomplete and variation in readability scores indicated high levels of literacy were required. Discussion: Access to, and quality of, patient information for hypodontia is inadequate. Current resources are not sufficiently comprehensive to prepare young patients to engage in shared dental care decisions with their parents and/or dental professionals. Conclusion: There is a need for improved access to, and provision of, information about hypodontia if dental professionals want to meet best practice guidance and involve patients in shared decision-making

    Health insurance, neighborhood income, and emergency department usage by Utah children 1996–1998

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    BACKGROUND: It is estimated that approximately half of emergency department (ED) usage in the U.S. and other developed countries is for non-urgent conditions and that this usage is related to availability, social, and economic factors. We examined pediatric ED usage in a U.S. state with respect to income, health insurance status, types of medical conditions, and whether introduction of managed care affected utilization by Medicaid children. METHODS: Emergency department usage rates were calculated from 1996 through 1998 using Utah ED data for children with commercial health insurance, Medicaid, for uninsured children, and by income group estimating neighborhood household income from Zip code of residence. We analyzed usage following the July 1996 transition of Utah Medicaid to managed care. RESULTS: Children with Medicaid had approximately 50% greater ED utilization rates than children with commercial health insurance or uninsured children. The majority of usage for Medicaid and uninsured children was for non-traumatic conditions. Only 35% of total ED usage was for non-emergent or non-urgent conditions and this was related to both Medicaid and low household income. Children lacking health insurance were more likely to be discharged against medical advice (OR = 2.36, 95% C.I. 1.88–2.96). There was no reduction in Medicaid ED usage following the transition to managed care. CONCLUSION: Usage of ED services is related to both health insurance status and income. Children lacking health insurance and Medicaid children have excessive usage for conditions which could be treated in a primary care setting. That managed care does not reduce Medicaid ED usage is consistent with findings of other studies

    The state of the Martian climate

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    60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

    Efficacy of a training intervention on the quality of practitioners' decision support for patients deciding about place of care at the end of life: A randomized control trial: Study protocol

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    <p>Abstract</p> <p>Background</p> <p>Most people prefer home palliation but die in an institution. Some experience decisional conflict when weighing options regarding place of care. Clinicians can identify patients' decisional needs and provide decision support, yet generally lack skills and confidence in doing so. This study aims to determine whether the quality of clinicians' decision support can be improved with a brief, theory-based, skills-building intervention.</p> <p>Theory</p> <p>The Ottawa Decision Support Framework (ODSF) guides an evidence based, practical approach to assist clinicians in providing high-quality decision support. The ODSF proposes that decisional needs [personal uncertainty, knowledge, values clarity, support, personal characteristics] strongly influence the quality of decisions patients make. Clinicians can improve decision quality by providing decision support to address decisional needs [clarify decisional needs, provide facts and probabilities, clarify values, support/guide deliberation, monitor/facilitate progress].</p> <p>Methods/Design</p> <p>The efficacy of a brief education intervention will be assessed in a two-phase study. In phase one a focused needs assessment will be conducted with key informants. Phase two is a randomized control trial where clinicians will be randomly allocated to an intervention or control group. The intervention, informed by the needs assessment, knowledge transfer best practices and the ODSF, comprises an online tutorial; an interactive skills building workshop; a decision support protocol; performance feedback, and educational outreach. Participants will be assessed: a) at baseline (quality of decision support); b) after the tutorial (knowledge); and c) four weeks after the other interventions (quality of decision support, intention to incorporate decision support into practice and perceived usefulness of intervention components). Between group differences in the primary outcome (quality of decision support scores) will be analyzed using ANOVA.</p> <p>Discussion</p> <p>Few studies have investigated the efficacy of an evidence-based, theory guided intervention aimed at assisting clinicians to strengthen their patient decision support skills. Expanding our understanding of how clinicians can best support palliative patients' decision-making will help to inform best practices in patient-centered palliative care. There is potential transferability of lessons learned to other care situations such as chronic condition management, advance directives and anticipatory care planning. Should the efficacy evaluation reveal clear improvements in the quality of decision support provided by clinicians who received the intervention, a larger scale implementation and effectiveness trial will be considered.</p> <p>Trial registration</p> <p>This study is registered as NCT00614003</p

    Size matters: just how big is BIG?: Quantifying realistic sample size requirements for human genome epidemiology

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    Background Despite earlier doubts, a string of recent successes indicates that if sample sizes are large enough, it is possible—both in theory and in practice—to identify and replicate genetic associations with common complex diseases. But human genome epidemiology is expensive and, from a strategic perspective, it is still unclear what ‘large enough’ really means. This question has critical implications for governments, funding agencies, bioscientists and the tax-paying public. Difficult strategic decisions with imposing price tags and important opportunity costs must be taken

    Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas

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    This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin
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