8,461 research outputs found

    Nonlinear actuator disk theory and flow field calculations, including nonuniform loading

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    Actuator disk theory and flow field calculations for propeller induced flow with nonuniform circulation distributio

    U.S. Navy: Vietnam

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    Joining up health and bioinformatics: e-science meets e-health

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    CLEF (Co-operative Clinical e-Science Framework) is an MRC sponsored project in the e-Science programme that aims to establish methodologies and a technical infrastructure forthe next generation of integrated clinical and bioscience research. It is developing methodsfor managing and using pseudonymised repositories of the long-term patient histories whichcan be linked to genetic, genomic information or used to support patient care. CLEF concentrateson removing key barriers to managing such repositories ? ethical issues, informationcapture, integration of disparate sources into coherent ?chronicles? of events, userorientedmechanisms for querying and displaying the information, and compiling the requiredknowledge resources. This paper describes the overall information flow and technicalapproach designed to meet these aims within a Grid framework

    Political Engagement During a Presidential Election Year: A Case Study of Media Literacy Students

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    This exploratory, mixed-methods study uses data gathered during the previous U.S. presidential election in 2012 to evaluate student political engagement and digital culture. Survey results and media diary entries revealed that college students enrolled in a media literacy course during Super Tuesday or Election Day gravitated toward low-barrier political actions and expressive modes of citizenship, and they were most engaged when there was a social component to following election news. These results, coupled with recent data on political engagement and media consumption, present an opportunity to consider the role of digital platforms and online communities in the 2016 election

    Statistics and Quantum Chaos

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    We use multi-time correlation functions of quantum systems to construct random variables with statistical properties that reflect the degree of complexity of the underlying quantum dynamics.Comment: 12 pages, LateX, no figures, restructured versio

    A Quasi-Experimental Test of the Elementary School Success Profile Model of Assessment and Prevention

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    The Elementary School Success Profile Model of Assessment and Prevention (ESSP MAP) is an assessment and intervention strategy designed to improve student academic performance and behavior. The current analysis uses a quasi-experimental design to examine the relationship between a 3-year implementation of the ESSP MAP and aggregate academic outcomes. Students in one 3rd grade cohort (2007-2008) from 4 schools in 1 district received the intervention as they progressed from 3rd to 5th grade. Longitudinal hierarchical linear modeling with cross-classified effects of schools (N = 10) and cohorts (N = 11) was used to compare trajectories of reading proficiency percentages for the targeted group overall and its demographic subgroups with the trajectories of analogous groups of students across schools and time in the district. Findings suggest that the ESSP MAP was associated with greater growth in reading proficiency rates for Black and White students

    Respiratory Evaporative Water Loss During Hovering and Forward Flight in Hummingbirds

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    Hummingbirds represent an end point for small body size and water flux in vertebrates. We explored the role evaporative water loss (EWL) plays in management of their large water pool and its use in dissipating metabolic heat. We measured respiratory evaporative water loss (REWL) in hovering hummingbirds in the field (6 species) and over a range of speeds in a wind tunnel (1 species) using an open-circuit mask respirometry system. Hovering REWL during the active period was positively correlated with operative temperature (Te) likely due to some combination of an increase in the vapor-pressure deficit, increase in lung ventilation rate, and reduced importance of dry heat transfer at higher Te. In rufous hummingbirds (Selasphorus rufus; 3.3 g) REWL during forward flight at 6 and 10 m/s was less than half the value for hovering. The proportion of total dissipated heat (TDH) accounted for by REWL during hovering at Te\u3e40 °C was b40% in most species. During forward flight in S. rufus the proportion of TDH accounted for by REWL was ~35% less than for hovering. REWL in hummingbirds is a relatively small component of the water budget compared with other bird species (b20%) so cutaneous evaporative water loss and dry heat transfer must contribute significantly to thermal balance in hummingbirds

    Fractionating Choice: A Study on Reward Discrimination, Preference, and Relative Valuation in the Rat (Rattus Norvegicus)

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    Choice behavior combines discrimination between distinctive outcomes, preference for specific outcomes and relative valuation of comparable outcomes. Previous work has focused on 1 component (i.e., preference) disregarding other influential processes that might provide a more complete understanding. Animal models of choice have been explored primarily utilizing extensive training, limited freedom for multiple decisions and sparse behavioral measures constrained to a single phase of motivated action. The present study used a paradigm that combines different elements of previous methods with the goal to distinguish among components of choice and explore how well components match predictions based on risk-sensitive foraging strategies. In order to analyze discrimination and relative valuation, it was necessary to have an option that shifted and an option that remained constant. Shifting outcomes among weeks included a change in single-option outcome (0 to 1 to 2 pellets) or a change in mixed-option outcome (0 or 5 to 0 or 3 to 0 or 1 pellets). Constant outcomes among weeks were also mixed-option (0 or 3 pellets) or single-option (1 pellet). Shifting single-option outcomes among weeks led to better discrimination, more robust preference and significant incentive contrast effects for the alternative outcome. Shifting multioptions altered choice components and led to dissociations among discrimination, preference, and reduced contrast effects. During extinction, all components were impacted with the greatest deficits during the shifting mixed-option outcome sessions. Results suggest choice behavior can be optimized for 1 component but suboptimal for others depending upon the complexity of alterations in outcome value between options
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