46,237 research outputs found

    Student-centered interventions the key to student health care worker influenza vaccination

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    Objectives: To investigate influenza vaccination uptake rates, attitudes and motivations towards influenza vaccination among student health care workers (HCWs). Methods: Self-reported influenza vaccination uptake among student HCWs at The University of Notre Dame Australia, Fremantle, Western Australia (UNDAF) was surveyed before and after implementation of a peer-led, student-centered campaign to raise awareness of, and improve access to, influenza vaccination. Data were weighted and analysed using logistic regression. Results: Pre-campaign influenza vaccination uptake was 36.3% (95% CI=31.8%-40.8%), with students identifying lack of awareness of both the Australian Government’s recommendations and university policy, cost, and inconvenience of vaccine access as key barriers. Post-campaign vaccination coverage increased significantly to 55.9% (95% CI=52.2%-59.6%). Multivariate logistic regression, controlled for statistically insignificant confounders of age and gender, showed that being a student HCW in 2014 (campaign year) was significantly and independently associated with influenza vaccination (OR 2.2, 95% CI=1.7-2.9, P\u3c0.001). Other significant factors were eligibility for National Immunisation Programme (NIP) funded vaccine (OR 12.3, 95% CI=6.3 – 24.0, P\u3c0.001), employment as HCWs (OR 1.9, 95% CI=1.5-2.6, P\u3c0.001), recalled campaign materials (OR 1.8, 95% CI=1.2 – 2.7, P=0.002) and enrolled in medicine (OR 1.6, 95% CI=1.1-2.4, P=0.016). Conclusions: Student HCWs’ influenza vaccination uptake improved significantly following a low-cost, peer-led promotional campaign. This approach can be adapted to other settings

    Snow tussocks, chaos, and the evolution of mast seeding

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    One hitherto intractable problem in studying mast seeding (synchronous intermittent heavy flowering by a population of perennial plants) is determining the relative roles of weather, plant reserves, and evolutionary selective pressures such as predator satiation. We parameterize a mechanistic resource-based model for mast seeding in Chionochloa pallens (Poaceae) using a long-term individually structured data set. Each plant's energy reserves were reconstructed using annual inputs (growing degree days), outputs (flowering), and a novel regression technique. This allowed the estimation of the parameters that control internal plant resource dynamics, and thereby allowed different models for masting to be tested against each other. Models based only on plant size, season degree days, and/or climatic cues (warm January temperatures) fail to reproduce the pattern of autocovariation in individual flowering and the high levels of flowering synchrony seen in the field. This shows that resource-matching or simple cue-based models cannot account for this example of mast seeding. In contrast, the resource-based model pulsed by a simple climate cue accurately describes both individual-level and population-level aspects of the data. The fitted resource-based model, in the absence of environmental forcing, has chaotic (but often statistically periodic) dynamics. Environmental forcing synchronizes individual reproduction, and the models predict highly variable seed production in close agreement with the data. An evolutionary model shows that the chaotic internal resource dynamics, as predicted by the fitted model, is selectively advantageous provided that adult mortality is low and seeds survive for more than 1 yr, both of which are true for C. pallens. Highly variable masting and chaotic dynamics appear to be advantageous in this case because they reduce seed losses to specialist seed predators, while balancing the costs of missed reproductive events

    The Infrared Nucleus of the Wolf-Rayet Galaxy Henize 2-10

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    We have obtained near-infrared images and mid-infrared spectra of the starburst core of the dwarf Wolf-Rayet galaxy He 2-10. We find that the infrared continuum and emission lines are concentrated in a flattened ellipse 3-4'' or 150 pc across which may show where a recent accretion event has triggered intense star formation. The ionizing radiation from this cluster has an effective temperature of 40,000 K, corresponding to 30M⊙30M_\odot stars, and the starburst is 0.5−1.5×1070.5-1.5 \times 10^7 years old.Comment: 17 pages Latex, 7 postscript figures, 1 postscript table, accepted to A

    Acoustic oscillations in solar and stellar flaring loops

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    Evolution of a coronal loop in response to an impulsive energy release is numerically modelled. It is shown that the loop density evolution curves exhibit quasi-periodic perturbations with the periods given approximately by the ratio of the loop length to the average sound speed, associated with the second standing harmonics of an acoustic wave. The density perturbations have a maximum near the loop apex. The corresponding field-aligned flows have a node near the apex. We suggest that the quasi-periodic pulsations with periods in the range 10-300 s, frequently observed in flaring coronal loops in the radio, visible light and X-ray bands, may be produced by the second standing harmonic of the acoustic mode

    BĂŒchwald-Hartwig reaction applied to synthesis of new luminescent liquid crystal triarylamines derived from isoxazoles

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    © 2015 Taylor & Francis Group, LLC. The present work describes the synthesis and characterization of novel series of triarylamines isoxazoles (TAA) addressed to the organic photovoltaic materials. Diarylisoxazoles were synthesized by sequential [3+2] 1,3-dipolar cycloaddition reaction between arylnitrile oxides and selected arylalkenes followed by MnO2-oxidation. Isoxazoles were coupled to diarylamines by BĂŒchwald-Hartwig reaction to afford desired compounds 6a-k. Some TAA display liquid-crystalline behaviour and UV-Vis absorption and fluorescence emission were analysed for all samples of TAA 6a-k

    Influence of blade aerodynamic model on prediction of helicopter rotor aeroacoustic signatures

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    Brown’s vorticity transport model has been used to investigate how the local blade aerodynamic model influences the quality of the prediction of the high-frequency airloads associated with blade–vortex interactions, and thus the accuracy with which the acoustic signature of a helicopter rotor can be predicted. The vorticity transport model can accurately resolve the structure of the wake of the rotor and allows significant flexibility in the way that the blade loading can be represented. The Second Higher-Harmonic Control Aeroacoustics Rotor Test was initiated to provide experimental insight into the acoustic signature of a rotor in cases of strong blade–vortex interaction. Predictions of two models for the local blade aerodynamics are compared with the test data. A marked improvement in accuracy of the predicted high-frequency airloads and acoustic signature is obtained when a lifting-chord model for the blade aerodynamics is used instead of a lifting-line-type approach. Errors in the amplitude and phase of the acoustic peaks are reduced, and the quality of the prediction is affected to a lesser extent by the computational resolution of the wake, with the lifting-chord model producing the best representation of the distribution of sound pressure below the rotor
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