4,690 research outputs found

    Managing Public Relations ; Using Radio for Primary Health Care

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    Reviews of Managing Public Relations, by James E. Grunig and Todd Hunt; Using Radio for Primary Health Care, by W. A. Sweeney and M. B. Parlato

    Assessing the Likelihood of Rare Medical Events in Astronauts

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    Despite over half a century of manned space flight, the space flight community is only now coming to fully assess the short and long term medical dangers of exposure to reduced gravity environments. Further, as new manned spacecraft are designed and with the advent of commercial flight capabilities to the general public, a full understanding of medical risk becomes even more critical for maintaining and understanding mission safety and crew health. To address these critical issues, the National Aeronautics and Space Administration (NASA) Human Research Program (HRP) has begun to address the medical hazards with a formalized risk management approach by effectively identifying and attempting to mitigate acute and chronic medical risks to manned space flight. This paper describes NASA Glenn Research Center?s (GRC) efforts to develop a systematic methodology to assess the likelihood of in-flight medical conditions. Using a probabilistic approach, medical risks are assessed using well established and accepted biomedical and human performance models in combination with fundamentally observed data that defines the astronauts? physical conditions, environment and activity levels. Two different examples of space flight risk are used to show the versatility of our approach and how it successfully integrates disparate information to provide HRP decision makers with a valuable source of information which is otherwise lacking

    Forced Convective Diffusion and Interphase Heat and Mass Transfer: Computations of Radial Functions, Temperature and Concentration Fields, and Presentation of Local and Average Nusselt and Sherwood Numbers

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    Theoretical calculations have been carried out for forced convective transport for uniform streaming and uniaxial and biaxial extensional axisymmetric flows past single spheres. Homogeneous and heterogeneous chemical reactions, both of first and of second order have also been or are presently being treated. Orthogonality and other properties of Legendre functions have been used, together with introduction of an eigenfunction expansion, to reduce the mathematical description from a partial differential equation with variable coefficients, which is nonlinear for homogeneous second order chemical reactions, to a system of coupled ordinary differential equations for the radial modes. The numerical solutions of the latter have been obtained using the robust, adaptive grid algorithm of Pereyra and Lentini. Plots of the radial functions for given Peclet and Damkohler numbers give insight into the role and interaction of L and of r∞ (the number of terms necessary for convergence of the expansion and the finite radius at which the boundary conditions at infinity are imposed). From the radial modes, local and average Nusselt and Sherwood numbers, as well as the temperature and concentration fields, can be obtained. Plots of radial function families provide new insights that complement physicochemical understanding gained from isocontour plots of the temperature and concentration fields. Plots of local interphase transfer coefficients reflect the behavior of the flux field over the sphere surface and show how the average coefficients arise

    Estimated Probabililty of Chest Injury During an International Space Station Mission

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    The Integrated Medical Model (IMM) is a decision support tool that is useful to spaceflight mission planners and medical system designers when assessing risks and optimizing medical systems. The IMM project maintains a database of medical conditions that could occur during a spaceflight. The IMM project is in the process of assigning an incidence rate, the associated functional impairment, and a best and a worst case end state for each condition. The purpose of this work was to develop the IMM Chest Injury Module (CIM). The CIM calculates the incidence rate of chest injury per person-year of spaceflight on the International Space Station (ISS). The CIM was built so that the probability of chest injury during one year on ISS could be predicted. These results will be incorporated into the IMM Chest Injury Clinical Finding Form and used within the parent IMM model

    Management of expatriate medical assistance in Mozambique

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    This paper discusses how Mozambique coped with the health system needs in terms of specialized doctors since independence, in a troubled context of war, lack of financial resources and modifying settings of foreign aid. The Ministry of Health (MOH) managed to make up for its severe scarcity of specialist MDs especially through contracting expatriate technical assistance. Different scenarios, partnerships and contract schemes that have evolved since independence are briefly described, as well as self-reliance option possibility and implications. Lessons learned about donor initiatives aimed at contracting specialists from other developing countries are singled out. The issue of obtaining expertise and knowledge in the global market as cheap as possible is stressed, and realistic figures of cost planning are highlighted, as determined by the overall health system necessities and budget limitations

    M-Branes and Metastable States

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    We study a supersymmetry breaking deformation of the M-theory background found in arXiv:hep-th/0012011. The supersymmetric solution is a warped product of R^{2,1} and the 8-dimensional Stenzel space, which is a higher dimensional generalization of the deformed conifold. At the bottom of the warped throat there is a 4-sphere threaded by \tilde{M} units of 4-form flux. The dual (2+1)-dimensional theory has a discrete spectrum of bound states. We add p anti-M2 branes at a point on the 4-sphere, and show that they blow up into an M5-brane wrapping a 3-sphere at a fixed azimuthal angle on the 4-sphere. This supersymmetry breaking state turns out to be metastable for p / \tilde{M} < 0.054. We find a smooth O(3)-symmetric Euclidean bounce solution in the M5-brane world volume theory that describes the decay of the false vacuum. Calculation of the Euclidean action shows that the metastable state is extremely long-lived. We also describe the corresponding metastable states and their decay in the type IIA background obtained by reduction along one of the spatial directions of R^{2,1}.Comment: 33 pages, 5 figures; v2 note adde

    Corner contributions to holographic entanglement entropy

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    The entanglement entropy of three-dimensional conformal field theories contains a universal contribution coming from corners in the entangling surface. We study these contributions in a holographic framework and, in particular, we consider the effects of higher curvature interactions in the bulk gravity theory. We find that for all of our holographic models, the corner contribution is only modified by an overall factor but the functional dependence on the opening angle is not modified by the new gravitational interactions. We also compare the dependence of the corner term on the new gravitational couplings to that for a number of other physical quantities, and we show that the ratio of the corner contribution over the central charge appearing in the two-point function of the stress tensor is a universal function for all of the holographic theories studied here. Comparing this holographic result to the analogous functions for free CFT's, we find fairly good agreement across the full range of the opening angle. However, there is a precise match in the limit where the entangling surface becomes smooth, i.e., the angle approaches π\pi, and we conjecture the corresponding ratio is a universal constant for all three-dimensional conformal field theories. In this paper, we expand on the holographic calculations in our previous letter arXiv:1505.04804, where this conjecture was first introduced.Comment: 62 pages, 6 figures, 1 table; v2: minor modifications to match published version, typos fixe

    Physical Response Functions of Strongly Coupled Massive Quantum Liquids

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    We study physical properties of strongly coupled massive quantum liquids from their spectral functions using the AdS/CFT correspondence. The generic model that we consider is dense, heavy fundamental matter coupled to SU(N_c) super Yang-Mills theory at finite temperature above the deconfinement phase transition but below the scale set by the baryon number density. In this setup, we study the current-current correlators of the baryon number density using new techniques that employ a scaling behavior in the dual geometry. Our results, the AC conductivity, the quasi-particle spectrum and the Drude-limit parameters like the relaxation time are simple temperature-independent expressions that depend only on the mass-squared to density ratio and display a crossover between a baryon- and meson-dominated regime. We concentrated on the (2+1)-dimensional defect case, but in principle our results can also be generalized straightforwardly to other cases.Comment: 21 pages, 10 figures, extra paragraph and figure are added in response to referee's comment

    N=2 Topological Yang-Mills Theory on Compact K\"{a}hler Surfaces

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    We study a topological Yang-Mills theory with N=2N=2 fermionic symmetry. Our formalism is a field theoretical interpretation of the Donaldson polynomial invariants on compact K\"{a}hler surfaces. We also study an analogous theory on compact oriented Riemann surfaces and briefly discuss a possible application of the Witten's non-Abelian localization formula to the problems in the case of compact K\"{a}hler surfaces.Comment: ESENAT-93-01 & YUMS-93-10, 34pages: [Final Version] to appear in Comm. Math. Phy
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