1,967 research outputs found

    Global health security and islands as seen through COVID-19 and vaccination

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    Since the declaration of COVID-19 as a pandemic in March 2020, significant research and attention has focused on countries’ abilities and interests in enacting response measures to the spread of the coronavirus including lockdowns, travel restrictions, and vaccination programmes to contain infections, hospitalisations, and deaths. As the pandemic has continued, much discussion has also centred on the ability of islands to control borders, enact public health measures, and keep the virus out or controlled, owing in part to presumed islandness characteristics of isolation and remoteness. Drawing from ongoing empirical examples of island experiences in the context of COVID-19, this article examines to what extent islandness impacts health concerns and health responses within aspects of global health security and health systems. In considering how islands around the world have been implementing health security measures regarding COVID-19, linkages or suggested linkages among islands, global health security, and pandemics indicate the lack of exceptionality of islands and archipelagos. That is, how islandness or lack thereof is managed ends up being far more important for global health security outcomes than islandness itself

    Transonic wind tunnel test of a 14 percent thick oblique wing

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    An experimental investigation was conducted at the ARC 11- by 11-Foot Transonic Wind Tunnel as part of the Oblique Wing Research Aircraft Program to study the aerodynamic performance and stability characteristics of a 0.087-scale model of an F-8 airplane fitted with an oblique wing designed by Rockwell International. The 10.3 aspect ratio, straight-tapered wing of 0.14 thickness/chord ratio was tested at two different mounting heights above the fuselage. Additional tests were conducted to assess low-speed behavior with and without flaps, aileron effectiveness at representative flight conditions, and transonic drag divergence with 0 degree wing sweep. Longitudinal stability data were obtained at sweep angles of 0, 30, 45, 60, and 65 degrees, at Mach numbers ranging from 0.25 to 1.40. Test Reynolds numbers varied from 3.2 to 6.6 x 10 exp 6/ft. and angle of attack ranged from -5 to +18 degrees. Most data were taken at zero sideslip, but a few runs were at sideslip angles of +/- 5 degrees. The raised wing position proved detrimental overall, although side force and yawing moment were reduced at some conditions. Maximum lift coefficient with the flaps deflected was found to fall short of the value predicted in the preliminary design document. The performance and trim characteristics of the present wing are generally inferior to those obtained for a previously tested wing designed at ARC

    The Qualitative Interview in Psychology and the Study of Social Change: Sexual Identity Development, Minority Stress, and Health in the Generations Study.

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    Interviewing is considered a key form of qualitative inquiry in psychology that yields rich data on lived experience and meaning making of life events. Interviews that contain multiple components informed by specific epistemologies have the potential to provide particularly nuanced perspectives on psychological experience. We offer a methodological model for a multi-component interview that draws upon both pragmatic and constructivist epistemologies to examine generational differences in the experience of identity development, stress, and health among contemporary sexual minorities in the United States. Grounded in theories of life course, narrative, and intersectionality, we designed and implemented a multi-component protocol that was administered among a diverse sample of three generations of sexual minority individuals. For each component, we describe the purpose and utility, underlying epistemology, foundational psychological approach, and procedure, and we provide illustrative data from interviewees. We discuss procedures undertaken to ensure methodological integrity in process of data collection, illustrating the implementation of recent guidelines for qualitative inquiry in psychology. We highlight the utility of this qualitative multi-component interview to examine the way in which sexual minorities of distinct generations have made meaning of significant social change over the past half-century

    Performance Evaluation and Optimization of Math-Similarity Search

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    Similarity search in math is to find mathematical expressions that are similar to a user's query. We conceptualized the similarity factors between mathematical expressions, and proposed an approach to math similarity search (MSS) by defining metrics based on those similarity factors [11]. Our preliminary implementation indicated the advantage of MSS compared to non-similarity based search. In order to more effectively and efficiently search similar math expressions, MSS is further optimized. This paper focuses on performance evaluation and optimization of MSS. Our results show that the proposed optimization process significantly improved the performance of MSS with respect to both relevance ranking and recall.Comment: 15 pages, 8 figure

    Partition Functions of Non-Abelian Quantum Hall States

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    Partition functions of edge excitations are obtained for non-Abelian Hall states in the second Landau level, such as the anti-Read-Rezayi state, the Bonderson-Slingerland hierarchy and the Wen non-Abelian fluid, as well as for the non-Abelian spin-singlet state. The derivation is straightforward and unique starting from the non-Abelian conformal field theory data and solving the modular invariance conditions. The partition functions provide a complete account of the excitation spectrum and are used to describe experiments of Coulomb blockade and thermopower.Comment: 42 pages, 3 figures; published version; minor corrections to sect. 4.

    Theory of Magnetodynamics Induced by Spin Torque in Perpendicularly Magnetized Thin Films

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    A nonlinear model of spin wave excitation using a point contact in a thin ferromagnetic film is introduced. Large-amplitude magnetic solitary waves are computed, which help explain recent spin-torque experiments. Numerical simulations of the fully nonlinear model predict excitation frequencies in excess of 0.2 THz for contact diameters smaller than 6 nm. Simulations also predict a saturation and red shift of the frequency at currents large enough to invert the magnetization under the point contact. The theory is approximated by a cubic complex Ginzburg-Landau type equation. The mode's nonlinear frequency shift is found by use of perturbation techniques, whose results agree with those of direct numerical simulations.Comment: 5 pages, 4 figures, submitted to PR
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