4,248 research outputs found

    The Future of Emergency Medicine Public Health Research

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    This chapter addresses past successes and challenges and then elaborates on the potential for further advances in three areas that bridge emergency medicine and the broader public health and health services research agenda: (1) monitoring health care access; (2) surveillance of diseases, injuries, and health risks; and (3) delivering clinical preventive services. This article also suggests ways to advance policy-relevant research on systems of health and social welfare that impact the health of the public

    Selecting and implementing overview methods: implications from five exemplar overviews

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    This is the final version of the article. Available from BioMed Central via the DOI in this record.Background Overviews of systematic reviews are an increasingly popular method of evidence synthesis; there is a lack of clear guidance for completing overviews and a number of methodological challenges. At the UK Cochrane Symposium 2016, methodological challenges of five overviews were explored. Using data from these five overviews, practical implications to support methodological decision making of authors writing protocols for future overviews are proposed. Methods Methods, and their justification, from the five exemplar overviews were tabulated and compared with areas of debate identified within current literature. Key methodological challenges and implications for development of overview protocols were generated and synthesised into a list, discussed and refined until there was consensus. Results Methodological features of three Cochrane overviews, one overview of diagnostic test accuracy and one mixed methods overview have been summarised. Methods of selection of reviews and data extraction were similar. Either the AMSTAR or ROBIS tool was used to assess quality of included reviews. The GRADE approach was most commonly used to assess quality of evidence within the reviews. Eight key methodological challenges were identified from the exemplar overviews. There was good agreement between our findings and emerging areas of debate within a recent published synthesis. Implications for development of protocols for future overviews were identified. Conclusions Overviews are a relatively new methodological innovation, and there are currently substantial variations in the methodological approaches used within different overviews. There are considerable methodological challenges for which optimal solutions are not necessarily yet known. Lessons learnt from five exemplar overviews highlight a number of methodological decisions which may be beneficial to consider during the development of an overview protocol.The overview conducted by Pollock [19] was supported by a project grant from the Chief Scientist Office of the Scottish Government. The overview conducted by McClurg [21] was supported by a project grant by the Physiotherapy Research Foundation. The overview by Hunt [22] was supported as part of doctoral programme funding by the National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care South West Peninsula (PenCLAHRC). The overview conducted by Estcourt [20] was supported by an NIHR Cochrane Programme Grant for the Safe and Appropriate Use of Blood Components. The overview conducted by Brunton [23] was commissioned by the Department of Health as part of an ongoing programme of work on health policy research synthesis. Alex Pollock is employed by the Nursing, Midwifery and Allied Health Professions (NMAHP) Research Unit, which is supported by the Chief Scientist Office of the Scottish Government. Pauline Campbell is supported by the Chief Nurses Office of the Scottish Government

    Gluon polarization tensor in color magnetic background

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    In SU(2) gluodynamics we calculate the gluon polarization tensor in an Abelian homogeneous magnetic field in one-loop order in the Lorentz background field gauge. It turned out to be non transversal and consisting of ten tensor structures and corresponding form factors - four in color neutral and six in color charged sector. Seven tensor structures are transversal, three are not. The non transversal parts are obtained by explicit calculation. We represent the form factors in terms of double parametric integrals which can be computed numerically. Some examples are provided and possible applications are discussed.Comment: A number of misprints is correcte

    Book Reviews

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    Finite Element Analysis of Multipass Effects of Vehicles on Soil Compaction

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    Finite element procedure was used to simulate multiple wheel loading and to predict its effect on soil compaction. Results of nonlinear analysis, conducted using an incremental loading procedure, show effects of tire size, soil type, and number of passes on soil compaction. The results of the study also demonstrate the potential use of the procedure in compaction related studies. However, experimental verification of the model is necessary before the procedure can be recommended for wider use

    Development and Uses of Upper-division Conceptual Assessment

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    The use of validated conceptual assessments alongside more standard course exams has become standard practice for the introductory courses in many physics departments. These assessments provide a more standard measure of certain learning goals, allowing for comparisons of student learning across instructors, semesters, and institutions. Researchers at the University of Colorado Boulder have developed several similar assessments designed to target the more advanced physics content of upper-division classical mechanics, electrostatics, quantum mechanics, and electrodynamics. Here, we synthesize the existing research on our upper-division assessments and discuss some of the barriers and challenges associated with developing, validating, and implementing these assessments as well as some of the strategies we have used to overcome these barriers.Comment: 12 pages, 5 figures, submitted to the Phys. Rev. ST - PER Focused collection on Upper-division PE

    Tomographic imaging and scanning thermal microscopy: thermal impedance tomography

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    The application of tomographic imaging techniques developed for medical applications to the data provided by the scanning thermal microscope will give access to true three-dimensional information on the thermal properties of materials on a mm length scale. In principle, the technique involves calculating and inverting a sensitivity matrix for a uniform isotropic material, collecting ordered data at several modulation frequencies, and multiplying the inverse of the matrix with the data vector. In practice, inversion of the matrix in impractical, and a novel iterative technique is used. Examples from both simulated and real data are given

    New Constraints on the Origin of the Short-Term Cyclical Variability of the Wolf-Rayet Star WR 46

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    The Wolf-Rayet star WR 46 is known to exhibit a very complex variability pattern on relatively short time scales of a few hours. Periodic but intermittent radial velocity shifts of optical lines as well as multiple photometric periods have been found in the past. Non-radial pulsations, rapid rotational modulation or the presence of a putative low-mass companion have been proposed to explain the short-term behaviour. In an effort to unveil its true nature, we observed WR 46 with FUSE (Far Ultraviolet Spectroscopic Explorer) over several short-term variability cycles. We found significant variations on a time scale of ~8 hours in the far-ultraviolet (FUV) continuum, in the blue edge of the absorption trough of the OVI {\lambda}{\lambda}1032, 1038 doublet P Cygni profile and in the SVI {\lambda}{\lambda}933, 944 P Cygni absorption profile. We complemented these observations with X-ray and UV light-curves and an X-ray spectrum from archival XMM-Newton (X-ray Multi-Mirror Mission - Newton Space Telescope) data. The X-ray and UV light-curves show variations on a time scale similar to the variability found in the FUV. We discuss our results in the context of the different scenarios suggested to explain the short-term variability of this object and reiterate that non-radial pulsations is the most likely to occur.Comment: 36 pages, 11 figures. Accepted for publication in Ap
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