1,346 research outputs found

    Electric Switching of the Charge-Density-Wave and Normal Metallic Phases in Tantalum Disulfide Thin-Film Devices

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    We report on switching among three charge-density-wave phases - commensurate, nearly commensurate, incommensurate - and the high-temperature normal metallic phase in thin-film 1T-TaS2 devices induced by application of an in-plane electric field. The electric switching among all phases has been achieved over a wide temperature range, from 77 K to 400 K. The low-frequency electronic noise spectroscopy has been used as an effective tool for monitoring the transitions, particularly the switching from the incommensurate charge-density-wave phase to the normal metal phase. The noise spectral density exhibits sharp increases at the phase transition points, which correspond to the step-like changes in resistivity. Assignment of the phases is consistent with low-field resistivity measurements over the temperature range from 77 K to 600 K. Analysis of the experimental data and calculations of heat dissipation suggest that Joule heating plays a dominant role in the electric-field induced transitions in the tested 1T-TaS2 devices on Si/SiO2 substrates. The possibility of electrical switching among four different phases of 1T-TaS2 is a promising step toward nanoscale device applications. The results also demonstrate the potential of noise spectroscopy for investigating and identifying phase transitions in materials.Comment: 32 pages, 7 figure

    Self-Esteem in Second Life: An inWorld Group Intervention for Women with Disabilities

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    We are developing and investigating the feasibility of a self-esteem enhancement intervention in Second Life for women with physical disabilities. We adapted the curriculum of a previously tested workshop intervention to include features unique to this environment. Results of the beta test were very positive. Everyone involved showed considerable enthusiasm for exploring the new world of SL. The group leaders were challenged to resolve technical problems on every occasion, but these diminished and were perceived as manageable as the intervention progressed. Beta testers gave positive ratings to the information presented, organization, and usefulness of the intervention and found it very enjoyable although fatigue and stress limited the participation of some. They appreciated the use of Internet technology as an accommodation to their disability, in place of requiring transportation and additional energy expenditure to attend face-to-face meetings. Research issues related to engagement, measurement, and participant safety, as well as future research directions, are discussed. We conclude that SL has great potential for delivering health promotion interventions to women with physical disabilities

    The gatekeeper: individual differences are key in the chain from perception to behaviour

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    A basic assumption in mainstream social cognition is that the path from perception to behaviour is often automatic and direct, as supported for example by several experimental studies showing that priming can lead directly to a congruent behaviour without any need of conscious awareness of the process. However, we argue that the priming of a goal or an object activates individual differences in automatic evaluations at the associative level that in turn are the key predictors of action (gatekeeper model). A study (n = 90) on the American stereotype is presented to support the model. The results show that individual differences of the American stereotype as assessed with the IAT predicts a relevant action (essay evaluation) but only under condition of priming. Broader implications for predictive validity of implicit measures are also discussed

    Assessing sexual interest in children using the Go/No-Go Association Test

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    The present study investigated whether a latency-based Go/No-Go Association Task (GNAT) could be used as an indirect measure of sexual interest in children. A sample 29 individuals with a history of exclusive extrafamilial offenses against a child and 15 individuals with either a history of exclusive intrafamilial or mixed offenses (i.e., against both adults and children) were recruited from a treatment center in the US. Also, a sample of 26 nonoffenders was recruited from a university in the UK. All participants completed the Sexual Fantasy-GNAT, a Control-GNAT, and two self-report measures of sexual fantasy. It was hypothesized that, relative to the two comparison groups, the extrafamilial group would respond faster on the block that paired 'sexual fantasy' and 'children'. Also, GNAT scores were expected to correlate with child-related sexual fantasies. Support was found for both hypotheses. Response-latency indices were also found to effectively distinguish the extrafamilial group, as well as those who self-reported using child-related sexual fantasies. The implications of these findings, along with the study's limitations and suggestions for future research, are discussed

    Abuse Assessment Screen–Disability (AAS-D): Measuring Frequency, Type, and Perpetrator of Abuse toward Women with Physical Disabilities

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    An interview questionnaire was presented to a multiethnic sample of 511 women, age 18–64 years, at public and private specialty clinics to determine the frequency, type, and perpetrator of abuse toward women with physical disabilities. The four-question Abuse Assessment Screen–Disability (AAS-D) instrument detected a 9.8% prevalence (50 of 511) of abuse during the previous 12 months. Using two standard physical and sexual assault questions, 7.8% of the women (40 of 511) reported abuse. The two disability-related questions detected an additional 2.0% of the women (10 of 511) as abused. Women defining themselves as other than black, white, or Hispanic (i.e., Asian, mixed ethnic background) were more likely to report physical or sexual abuse or both, whereas disability-related abuse was reported almost exclusively by white women. The perpetrator of physical or sexual abuse was most likely to be an intimate partner. Disability-related abuse was attributed equally to an intimate partner, a care provider, or a health professional. This study concludes that both traditional abuse-focused questions and disability-specific questions are required to detect abuse toward women with physical disabilities

    A Gaze-Driven Evolutionary Algorithm to Study Aesthetic Evaluation of Visual Symmetry

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    Empirical work has shown that people like visual symmetry. We used a gaze-driven evolutionary algorithm technique to answer three questions about symmetry preference. First, do people automatically evaluate symmetry without explicit instruction? Second, is perfect symmetry the best stimulus, or do people prefer a degree of imperfection? Third, does initial preference for symmetry diminish after familiarity sets in? Stimuli were generated as phenotypes from an algorithmic genotype, with genes for symmetry (coded as deviation from a symmetrical template, deviation–symmetry, DS gene) and orientation (0° to 90°, orientation, ORI gene). An eye tracker identified phenotypes that were good at attracting and retaining the gaze of the observer. Resulting fitness scores determined the genotypes that passed to the next generation. We recorded changes to the distribution of DS and ORI genes over 20 generations. When participants looked for symmetry, there was an increase in high-symmetry genes. When participants looked for the patterns they preferred, there was a smaller increase in symmetry, indicating that people tolerated some imperfection. Conversely, there was no increase in symmetry during free viewing, and no effect of familiarity or orientation. This work demonstrates the viability of the evolutionary algorithm approach as a quantitative measure of aesthetic preference

    Science as behaviour: Using a behaviour change approach to increase uptake of open science.

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    This is an Accepted Manuscript of an article published by Taylor & Francis in Psychology & Health on 29 October 2019, available online: http://www.tandfonline.com/10.1080/08870446.2019.167937

    The bright optical flash from GRB 060117

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    We present a discovery and observation of an extraordinarily bright prompt optical emission of the GRB 060117 obtained by a wide-field camera atop the robotic telescope FRAM of the Pierre Auger Observatory from 2 to 10 minutes after the GRB. We found rapid average temporal flux decay of alpha = -1.7 +- 0.1 and a peak brightness R = 10.1 mag. Later observations by other instruments set a strong limit on the optical and radio transient fluxes, unveiling an unexpectedly rapid further decay. We present an interpretation featuring a relatively steep electron-distribution parameter p ~ 3.0 and providing a straightforward solution for the overall fast decay of this optical transient as a transition between reverse and forward shock.Comment: Accepted to A&A, 4 pages, corected few typos pointed out by X.F. W
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