426 research outputs found

    Large Deviation Principles and Complete Equivalence and Nonequivalence Results for Pure and Mixed Ensembles

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    We consider a general class of statistical mechanical models of coherent structures in turbulence, which includes models of two-dimensional fluid motion, quasi-geostrophic flows, and dispersive waves. First, large deviation principles are proved for the canonical ensemble and the microcanonical ensemble. For each ensemble the set of equilibrium macrostates is defined as the set on which the corresponding rate function attains its minimum of 0. We then present complete equivalence and nonequivalence results at the level of equilibrium macrostates for the two ensembles.Comment: 57 page

    The Large Deviation Principle for Coarse-Grained Processes

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    The large deviation principle is proved for a class of L2L^2-valued processes that arise from the coarse-graining of a random field. Coarse-grained processes of this kind form the basis of the analysis of local mean-field models in statistical mechanics by exploiting the long-range nature of the interaction function defining such models. In particular, the large deviation principle is used in a companion paper to derive the variational principles that characterize equilibrium macrostates in statistical models of two-dimensional and quasi-geostrophic turbulence. Such macrostates correspond to large-scale, long-lived flow structures, the description of which is the goal of the statistical equilibrium theory of turbulence. The large deviation bounds for the coarse-grained process under consideration are shown to hold with respect to the strong L2L^2 topology, while the associated rate function is proved to have compact level sets with respect to the weak topology. This compactness property is nevertheless sufficient to establish the existence of equilibrium macrostates for both the microcanonical and canonical ensembles.Comment: 19 page

    Communication Disorders and Mental Health: A Scoping Review

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    This scoping review examined current research investigating the relationship between communication disorders and mental health disorders. Depression and anxiety disorders were correlated with communication disorders, but this relationship is complex. Next, potential interventions and clinical implications are discussed. The literature suggests that Speech-Language Pathologists and mental health professionals are most effective when working collaboratively to meet the needs of the whole child

    InP shallow-homojunction solar cells

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    Indium phosphide solar cells with very thin n-type emitters have been made by both ion implantation and metalorganic chemical vapor deposition. Air mass zero efficiencies as high as 18.8 percent (NASA measurement) have been achieved. Although calculations show that, as is the case with GaAs, a heterostructure is expected to be required for the highest efficiencies attainable, the material properties of InP give the shallow-homojunction structure a greater potential than in the case of GaAs. The best cells, which were those made by ion implantation, show open-circuit voltage (V sub oc) of 873 mV, short-circuit current of 357 A/sq m (35.7 mA/sq cm), and fill factor of 0.829. Improvements are anticipated in all three of these parameters. Internal quantum efficiency peaks at over 90 percent in the red end of the spectrum, but drops to 54 percent in the blue end. Other cells have achieved 74 percent in the blue end. Detailed modeling of the data indicates that a high front surface recombination velocity is responsible for the low blue response, that the carrier lifetime is high enough to allow good carrier collection from both the base and the emitter, and that the voltage is base-limited

    Fresh-Water Kill Of Oysters (Crassostrea virginica) In James River, Virginia, 1958

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    Fresh water invaded the upper half of James River seed area in winter and spring of 1958. Many oysters died between 1 May and 15 ·June. On some grounds, salinities did not become suitable until l July when temperature had reached 23°c. Death rates of native oysters were as high as 90 percent. Oysters exposed to fresh water from midwinter were conditioned to a low physiological state as evidenced by absence of heart beat, ciliary motion and mantle sensitivity when first opened. Oysters held in trays at one extremity of the seed area withstood fresh-water conditions similarly to oysters on natural bottom--in accordance with their previous history of exposure. Oysters in pans of fresh.well water at the Laboratory endured unsuitable conditions for similar periods as those in James River. Once broken, the conditioned state could not be regained at temperatures favoring activity. Apparently slow conditioning of oysters at low salinities and at low temperatures induces a state of narcosis which permits conservation of food supply and evasion of effects of temperature rises. This lasts only as long as closure is continuously enforced by fresh water or other factors

    Treatment Of Shell Cultch With Polystream To Increase The Yield Of Seed Oysters, Crassostrea Virginica

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    A commercial scale study was conducted on the Eastern Shore of Virginia during 1964, 1965 and 1966 to evaluate treatment of shell cultch with Polystream. Three intertidal reefs of the same approximate size were shelled with similar amounts of untreated shells

    Can moral case deliberation in research groups help to navigate research integrity dilemmas? A pilot study

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    There is an increased focus on fostering integrity in research by through creating an open culture where research integrity dilemmas can be discussed. We describe a pilot intervention study that used Moral Case Deliberation (MCD), a method that originated in clinical ethics support, to discuss research integrity dilemmas with researchers. Our research question was: can moral case deliberation in research groups help to navigate research integrity dilemmas? We performed 10 MCDs with 19 researchers who worked in three different research groups from three different disciplinary fields at a university in the Netherlands. We analyzed the dilemmas and values discussed, sent out a survey questionnaire to assess self-perceived moral competencies, and conducted in-depth interviews. We found research integrity dilemmas pertained to authorship disputes, supervision of junior co-workers, and questionable handling of data. Participants perceived the majority of moral competencies to a higher degree during the MCD when compared to perceiving them in daily practice afterward. Interviewees told us that they felt most comfortable discussing dilemmas among peers with whom they were not closely affiliated. We conclude that MCD sessions could be relevant in navigating research integrity dilemmas, but that revisions to ensure commitment and safety are required.</p

    Multilateral Biomedical Data Sharing in the One-year Joint US-Russian Mission on the International Space Station

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    The One Year Mission (1YM) by two astronauts on the International Space Station (ISS), starting in March 2015, offers a unique opportunity to expand multilateral collaboration by sharing data and resources among the partner agencies in preparation for planned space exploration missions beyond low Earth orbit. Agreements and protocols will be established for the collection, distribution, analysis and reporting of both research and clinical data. Data will be shared between the agencies sponsoring the investigators, and between the research and clinical medicine communities where common interests are identified. The assignment of only two astronauts, one Russian and the other American, to the 1YM necessitated creativity in bilateral efforts to maximize the biomedical return from the opportunity. Addition of Canadian, European and Japanese investigations make the effort even more integrative. There will be three types of investigations: joint, crossparticipation and dataexchange. The joint investigations have US and Russian coprincipal investigators, and the data acquired will be their common responsibility. The other two types must develop data sharing agreements and processes specific to their needs. A multilateral panel of ISS partner space agencies will develop policies for international exchange of scientific information to meet their science objectives and priorities. They will promote archiving of space flight data and will inform each other and the scientific community at large about the results obtained from space life sciences studies. Integration tasks for the 1YM are based on current experience from the ISS and previous efforts on the Russian space station Mir. Closer coordination between international partners requires more common approaches to remove barriers to multilateral resource utilization on the ISS. Greater integration in implementation should increase utilization efficiency to benefit all participants in spaceflight human research. This presentation will describe the overarching principles for multilateral data collection, analysis and sharing and for data security for medical and research data shared between ISS partners prior to release in public forums
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