2,995 research outputs found

    A feasibility study of signed consent for the collection of patient identifiable information for a national paediatric clinical audit database

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    Objectives: To investigate the feasibility of obtaining signed consent for submission of patient identifiable data to a national clinical audit database and to identify factors influencing the consent process and its success. Design: Feasibility study. Setting: Seven paediatric intensive care units in England. Participants: Parents/guardians of patients, or patients aged 12-16 years old, approached consecutively over three months for signed consent for submission of patient identifiable data to the national clinical audit database the Paediatric Intensive Care Audit Network (PICANet). Main outcome measures: The numbers and proportions of admissions for which signed consent was given, refused, or not obtained (form not returned or form partially completed but not signed), by age, sex, level of deprivation, ethnicity (South Asian or not), paediatric index of mortality score, length of hospital stay (days in paediatric intensive care). Results: One unit did not start and one did not fully implement the protocol, so analysis excluded these two units. Consent was obtained for 182 of 422 admissions (43%) (range by unit 9% to 84%). Most (101/182; 55%) consents were taken by staff nurses. One refusal (0.2%) was received. Consent rates were significantly better for children who were more severely ill on admission and for hospital stays of six days or more, and significantly poorer for children aged 10-14 years. Long hospital stays and children aged 10-14 years remained significant in a stepwise regression model of the factors that were significant in the univariate model. Conclusion: Systematically obtaining individual signed consent for sharing patient identifiable information with an externally located clinical audit database is difficult. Obtaining such consent is unlikely to be successful unless additional resources are specifically allocated to training, staff time, and administrative support

    Magnetic Reconnection with Radiative Cooling. I. Optically-Thin Regime

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    Magnetic reconnection, a fundamental plasma process associated with a rapid dissipation of magnetic energy, is believed to power many disruptive phenomena in laboratory plasma devices, the Earth magnetosphere, and the solar corona. Traditional reconnection research, geared towards these rather tenuous environments, has justifiably ignored the effects of radiation on the reconnection process. However, in many reconnecting systems in high-energy astrophysics (e.g., accretion-disk coronae, relativistic jets, magnetar flares) and, potentially, in powerful laser plasma and z-pinch experiments, the energy density is so high that radiation, in particular radiative cooling, may start to play an important role. This observation motivates the development of a theory of high-energy-density radiative magnetic reconnection. As a first step towards this goal, we present in this paper a simple Sweet--Parker-like theory of non-relativistic resistive-MHD reconnection with strong radiative cooling. First, we show how, in the absence of a guide magnetic field, intense cooling leads to a strong compression of the plasma in the reconnection layer, resulting in a higher reconnection rate. The compression ratio and the layer temperature are determined by the balance between ohmic heating and radiative cooling. The lower temperature in the radiatively-cooled layer leads to a higher Spitzer resistivity and hence to an extra enhancement of the reconnection rate. We then apply our general theory to several specific astrophysically important radiative processes (bremsstrahlung, cyclotron, and inverse-Compton) in the optically thin regime, for both the zero- and strong-guide-field cases. We derive specific expressions for key reconnection parameters, including the reconnection rate. We also discuss the limitations and conditions for applicability of our theory.Comment: 31 pages, 1 figur

    Bluff Body Fuel Mixer

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    A combustor is provided. The combustor may include an axial fuel injection system, and a radial fuel injection system aft of the axial fuel injection system. The axial fuel injection system includes a mixer having a bluff body at an exit port of the mixer, and a fuel injector disposed within the mixer. A fuel and air mixer is also provided and comprises an outer housing with an exit port and a bluff body. The bluff body extends across the exit port of the outer housing. A fuel injection system is also provided. The systems comprise a mixer having a bluff body at an exit port of the mixer and a fuel injector disposed within the mixer

    Analytic, Group-Theoretic Density Profiles for Confined, Correlated N-Body Systems

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    Confined quantum systems involving NN identical interacting particles are to be found in many areas of physics, including condensed matter, atomic and chemical physics. A beyond-mean-field perturbation method that is applicable, in principle, to weakly, intermediate, and strongly-interacting systems has been set forth by the authors in a previous series of papers. Dimensional perturbation theory was used, and in conjunction with group theory, an analytic beyond-mean-field correlated wave function at lowest order for a system under spherical confinement with a general two-body interaction was derived. In the present paper, we use this analytic wave function to derive the corresponding lowest-order, analytic density profile and apply it to the example of a Bose-Einstein condensate.Comment: 15 pages, 2 figures, accepted by Physics Review A. This document was submitted after responding to a reviewer's comment

    Conservation of Mass: An Old Principle That Needs More Usage in Hot & Humid Climates

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    Conservation of mass is such a basic principal that most designers no longer consider it for most design calculations. Design phase commissioning checks on several recent projects indicate designers should include conservation of mass calculations in the design. Recent retro-commissioning project indicate the concept should be considered by building owners and operators as well

    Design, analysis and test verification of advanced encapsulation systems, phase 2 program results

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    Optical, electrical isolation, thermal structural, structural deflection, and thermal tests are reported. The utility of the optical, series capacitance, and structural deflection models was verified

    The rarity of terrestrial gamma-ray flashes

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    We report on the first search for Terrestrial Gamma-ray Flashes (TGFs) from altitudes where they are thought to be produced. The Airborne Detector for Energetic Lightning Emissions (ADELE), an array of gamma-ray detectors, was flown near the tops of Florida thunderstorms in August/September 2009. The plane passed within 10 km horizontal distance of 1213 lightning discharges and only once detected a TGF. If these discharges had produced TGFs of the same intensity as those seen from space, every one should have been seen by ADELE. Separate and significant nondetections are established for intracloud lightning, negative cloud-to-ground lightning, and narrow bipolar events. We conclude that TGFs are not a primary triggering mechanism for lightning. We estimate the TGF-to-flash ratio to be on the order of 10^(−2) to 10^(−3) and show that TGF intensities cannot follow the well-known power-law distribution seen in earthquakes and solar flares, due to our limits on the presence of faint events

    Feeling Safe in the Dark : Examining the Effect of Entrapment, Lighting Levels, and Gender on Feelings of Safety and Lighting Policy Acceptability

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    This research examined to what extent physical factors, notably lighting and entrapment (blocked escape), and individual factors, notably gender, affect feelings of safety and the acceptability of reduced lighting levels. The authors reasoned that acceptability of reduced street lighting depends on perceived safety, which in turn depends on entrapment, lighting, and gender. Virtual representations of a residential street were used, systematically manipulating entrapment and lighting levels. As expected, people felt less safe in lower lighting and higher entrapment settings, and these settings were evaluated as less acceptable. Although women perceived a situation as less safe compared with men, the authors found no gender differences in acceptability, which extends previous research. Importantly, as hypothesized, perceived safety mediated the effect of lighting on acceptability levels, suggesting that people can accept lower lighting levels when social safety is not threatened

    Intervention Delivery Matters: What Mothers at High Risk for Type 2 Diabetes Want in a Diabetes Prevention Program—Results from a Comparative Effectiveness Trial

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    Participants in the ENCOURAGE Healthy Families Study, a family-focused, modified Diabetes Prevention Program, reported challenges to and preferences for engaging in a diabetes prevention program. Challenges with flexible intervention delivery, accessibility, the traditional group-based format, and Coronavirus Disease 2019 (COVID-19) exposure risk can be mitigated by participant preferences for one-on-one, virtual/online intervention delivery.This work was supported by the JPB Foundation, New York, NY and the IUPUI Signature Center Initiative Fund. Sponsors did not contribute to the writing of this report or in the decision to submit the article for publication. The Journal’s Rapid Service Fee is funded by the University of Arizona Health Sciences Center for Border Health Disparities
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