72,576 research outputs found

    Psychology ethics down under: A survey of student subject pools in Australia

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    A survey of the 37 psychology departments offering courses accredited by the Australian Psychological Society yielded a 92% response rate. Sixty-eight percent of departments employed students as research subjects, with larger departments being more likely to do so. Most of these departments drew their student subject pools from introductory courses. Student research participation was strictly voluntary in 57% of these departments, whereas 43% of the departments have failed to comply with normally accepted ethical standards. It is of great concern that institutional ethics committees apparently continue to condone, or fail to act against, unethical research practices. Although these committees have a duty of care to all subjects, the final responsibility for conducting research in an ethical manner lies with the individual researcher

    Cost-effectiveness analysis in R using a multi-state modelling survival analysis framework: a tutorial

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    This tutorial provides a step-by-step guide to performing cost-effectiveness analysis using a multi-state modelling approach. Alongside the tutorial we provide easy-to-use functions in the statistics package R. We argue this multi-state modelling approach using a package such as R has advantages over approaches where models are built in a spreadsheet package. In particular, using a syntax-based approach means there is a written record of what was done and the calculations are transparent. Reproducing the analysis is straightforward as the syntax just needs to be run again. The approach can be thought of as an alternative way to build a Markov decision analytic model, which also has the option to use a state-arrival extended approach if the Markov property does not hold. In the state-arrival extended multi-state model a covariate that represents patients’ history is included allowing the Markov property to be tested. We illustrate the building of multi-state survival models, making predictions from the models and assessing fits. We then proceed to perform a cost-effectiveness analysis including deterministic and probabilistic sensitivity analyses. Finally, we show how to create two common methods of visualising the results, namely cost-effectiveness planes and cost-effectiveness acceptability curves. The analysis is implemented entirely within R. It is based on adaptions to functions in the existing R package mstate, to accommodate parametric multi-state modelling which facilitates extrapolation of survival curves

    Renormalization Group Study of Magnetic Catalysis in the 3d Gross-Neveu Model

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    Magnetic catalysis describes the enhancement of symmetry breaking quantum fluctuations in chirally symmetric quantum field theories by the coupling of fermionic degrees of freedom to a magnetic background configuration. We use the functional renormalization group to investigate this phenomenon for interacting Dirac fermions propagating in (2+1)-dimensional spacetime, described by the Gross-Neveu model. We identify pointlike operators up to quartic fermionic terms that can be generated in the renormalization group flow by the presence of an external magnetic field. We employ the beta function for the fermionic coupling to quantitatively analyze the field dependence of the induced spectral gap. Within our pointlike truncation, the renormalization group flow provides a simple picture for magnetic catalysis.Comment: 14 pages, 6 figures, typos correcte

    NERVA irradiation program, GTR test 21. Volume 4 - Effect of radiation on structural materials tested at cryogenic and elevated temperatures

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    Effect of radiation on structural materials for NERVA engine tested at cryogenic and elevated temperatures - Vol.

    Polarimetric observations of σ\sigma Orionis E

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    Some massive stars possess strong magnetic fields that confine plasma in the circumstellar environment. These \textit{magnetospheres} have been studied spectroscopically, photometrically and, more recently, interferometrically. Here we report on the first firm detection of a magnetosphere in continuum linear polarization, as a result of monitoring of σ\sigma\,Ori\,E at the Pico dos Dias Observatory. {The non-zero intrinsic polarization indicates an asymmetric structure, whose minor elongation axis is oriented 150\fdg0 east of the celestial north.} A modulation of the polarization was observed, with a period of half of the rotation period, which supports the theoretical prediction of the presence of two diametrally opposed, co-rotating blobs of gas. A phase lag of -0.085 was detected between the polarization minimum and the primary minimum of the light curve, suggestive of a complex shape of the plasma clouds. We present a preliminary analysis of the data with the Rigidly Rotating Magnetosphere model, which could not reproduce simultaneously the photometric and polarimetric data. A toy model comprising two spherical co-rotating blobs {joined by a thin disk} proved more successful in reproducing the polarization modulation. {With this model we were able to determine that the total scattering mass of the thin disk is similar to the mass of the blobs (2Mb/Md=1.22M_{\rm b}/M_{\rm d}=1.2) and that the blobs are rotating counterclockwise on the plane of the sky.} This result shows that polarimetry can provide a diagnostic of the geometry of clouds, which will serve as an important constraint for {improving} the Rigidly Rotating Magnetosphere model.Comment: 5 pages, 4 figures, accepted for The Astrophysical Journal Letter

    La matriz imaginaria de las nuevas tecnologías

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    La expresión “nuevas tecnologías de la información y de la comunicación” y su realidad constituyen el centro de los discursos periodísticos, políticos y empresariales. Su uso indiscriminado como sujeto de promesas de todo tipo obliga a la realización de un análisis de sus condiciones de posibilidad y de representación. El presente artículo analiza esa matriz imaginaria de la sociedad contemporánea, dentro de la cual se hacen factibles las particulares significaciones que las nuevas tecnologías adquieren en la sociedad actual

    Thickness dependence of spin-orbit torques generated by WTe2

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    We study current-induced torques in WTe2/permalloy bilayers as a function of WTe2 thickness. We measure the torques using both second-harmonic Hall and spin-torque ferromagnetic resonance measurements for samples with WTe2 thicknesses that span from 16 nm down to a single monolayer. We confirm the existence of an out-of-plane antidamping torque, and show directly that the sign of this torque component is reversed across a monolayer step in the WTe2. The magnitude of the out-of-plane antidamping torque depends only weakly on WTe2 thickness, such that even a single-monolayer WTe2 device provides a strong torque that is comparable to much thicker samples. In contrast, the out-of-plane field-like torque has a significant dependence on the WTe2 thickness. We demonstrate that this field-like component originates predominantly from the Oersted field, thereby correcting a previous inference drawn by our group based on a more limited set of samples.Comment: 8 pages, 8 figure
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