900 research outputs found

    Using a Smartphone App to Teach Students Practical Epidemiological Skills

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    Background: Despite the evidence that shows the pedagogical benefits of experiential education, epidemiology instructors rarely utlize experiential activities to teach epidemiological concepts and skills. Poster presented at 8th annual 2016 Thomas Jefferson University Faculty Days

    Developing and Integrating the Management of Elder Abuse in Primary Practice: A Case Study Using A Web-Based CME Course Format

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    Introduction: As the population in the United States continues to age, more attention in primary practice settings is now devoted toward managing the care of the elderly. The occurrence of elder abuse is a growing problem. It is a condition many professionals in primary care may be ill prepared with the knowledge or resources to identify and manage. [See PDF for complete abstract

    Detection of weak gravitational lensing distortions of distant galaxies by cosmic dark matter at large scales

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    Most of the matter in the universe is not luminous and can be observed directly only through its gravitational effect. An emerging technique called weak gravitational lensing uses background galaxies to reveal the foreground dark matter distribution on large scales. Light from very distant galaxies travels to us through many intervening overdensities which gravitationally distort their apparent shapes. The observed ellipticity pattern of these distant galaxies thus encodes information about the large-scale structure of the universe, but attempts to measure this effect have been inconclusive due to systematic errors. We report the first detection of this ``cosmic shear'' using 145,000 background galaxies to reveal the dark matter distribution on angular scales up to half a degree in three separate lines of sight. The observed angular dependence of this effect is consistent with that predicted by two leading cosmological models, providing new and independent support for these models.Comment: 18 pages, 5 figures: To appear in Nature. (This replacement fixes tex errors and typos.

    A boundary stress tensor for higher-derivative gravity in AdS and Lifshitz backgrounds

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    We investigate the Brown-York stress tensor for curvature-squared theories. This requires a generalized Gibbons-Hawking term in order to establish a well-posed variational principle, which is achieved in a universal way by reducing the number of derivatives through the introduction of an auxiliary tensor field. We examine the boundary stress tensor thus defined for the special case of `massive gravity' in three dimensions, which augments the Einstein-Hilbert term by a particular curvature-squared term. It is shown that one obtains finite results for physical parameters on AdS upon adding a `boundary cosmological constant' as a counterterm, which vanishes at the so-called chiral point. We derive known and new results, like the value of the central charges or the mass of black hole solutions, thereby confirming our prescription for the computation of the stress tensor. Finally, we inspect recently constructed Lifshitz vacua and a new black hole solution that is asymptotically Lifshitz, and we propose a novel and covariant counterterm for this case.Comment: 25 pages, 1 figure; v2: minor corrections, references added, to appear in JHE

    A survey of performance enhancement of transmission control protocol (TCP) in wireless ad hoc networks

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    This Article is provided by the Brunel Open Access Publishing Fund - Copyright @ 2011 Springer OpenTransmission control protocol (TCP), which provides reliable end-to-end data delivery, performs well in traditional wired network environments, while in wireless ad hoc networks, it does not perform well. Compared to wired networks, wireless ad hoc networks have some specific characteristics such as node mobility and a shared medium. Owing to these specific characteristics of wireless ad hoc networks, TCP faces particular problems with, for example, route failure, channel contention and high bit error rates. These factors are responsible for the performance degradation of TCP in wireless ad hoc networks. The research community has produced a wide range of proposals to improve the performance of TCP in wireless ad hoc networks. This article presents a survey of these proposals (approaches). A classification of TCP improvement proposals for wireless ad hoc networks is presented, which makes it easy to compare the proposals falling under the same category. Tables which summarize the approaches for quick overview are provided. Possible directions for further improvements in this area are suggested in the conclusions. The aim of the article is to enable the reader to quickly acquire an overview of the state of TCP in wireless ad hoc networks.This study is partly funded by Kohat University of Science & Technology (KUST), Pakistan, and the Higher Education Commission, Pakistan

    Cytoplasmic human TDP-43 mislocalization induces widespread dendritic spine loss in mouse upper motor neurons

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    Amyotrophic lateral sclerosis (ALS) is defined by the destruction of upper- and lowermotor neurons. Post-mortem, nearly all ALS cases are positive for cytoplasmic aggregates containingthe DNA/RNA binding protein TDP-43. Recent studies indicate that this pathogenic mislocalizationof TDP-43 may participate in generating hyperexcitability of the upper motor neurons, the earliestdetectable change in ALS patients, yet the mechanisms driving this remain unclear. We investigatedhow mislocalisation of TDP-43 could initiate network dysfunction in ALS. We employed a tetracyclineinducible system to express either human wildtype TDP-43 (TDP-43WT) or human TDP-43 that cannotenter the nucleus (TDP-43∆NLS) in excitatory neurons (Camk2α promoter), crossed Thy1-YFPH miceto visualize dendritic spines, the major site of excitatory synapses. In comparison to both TDP-43WTand controls, TDP-43∆NLS drove a robust loss in spine density in all the dendrite regions of theupper motor neurons, most affecting thin spines. This indicates that TDP-43 is involved in thegeneration of network dysfunction in ALS likely through impacting the formation or durability ofexcitatory synapses. These findings are relevant to the vast majority of ALS cases, and providesfurther evidence that upper motor neurons may need to be protected from TDP-43 mediated synapticexcitatory changes early in disease

    An applied methodology for stakeholder identification in transdisciplinary research

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    In this paper we present a novel methodology for identifying stakeholders for the purpose of engaging with them in transdisciplinary, sustainability research projects. In transdisciplinary research, it is important to identify a range of stakeholders prior to the problem-focussed stages of research. Early engagement with diverse stakeholders creates space for them to influence the research process, including problem definition, from the start. However, current stakeholder analysis approaches ignore this initial identification process, or position it within the subsequent content-focussed stages of research. Our methodology was designed as part of a research project into a range of soil threats in seventeen case study locations throughout Europe. Our methodology was designed to be systematic across all sites. It is based on a snowball sampling approach that can be implemented by researchers with no prior experience of stakeholder research, and without requiring significant financial or time resources. It therefore fosters transdisciplinarity by empowering physical scientists to identify stakeholders and understand their roles. We describe the design process and outcomes, and consider their applicability to other research projects. Our methodology therefore consists of a two-phase process of design and implementation of an identification questionnaire. By explicitly including a design phase into the process, it is possible to tailor our methodology to other research projects
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