4,562 research outputs found

    There is still no evidence that videogames “harm” minors

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    Mass shootings in recent years such as those Newtown and Aurora in 2012 have once again placed the spotlight onto the role of violent videogames in encouraging youth violence. But is there a link between the two? Christopher J. Ferguson argues that the evidence shows that videogames do not cause violence, and that any alarmist claims that they do are based on minimal data. He writes that moral panics, such as those that arise after mass shootings, encourage psychologists to make extreme claims in order to gain prestige, headlines and grant funding

    The Assembly of Diversity in the Morphologies and Stellar Populations of High-Redshift Galaxies

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    We have studied the evolution in the morphologies, sizes, stellar-masses, colors, and internal color dispersion (ICD) of galaxies at z=1 and 2.3, using a near-IR, flux-limited catalog for the HDF-N. At z=1 most luminous galaxies have morphologies of early-to-mid Hubble-types, and many show transformations between their rest-frame UV-optical morphologies. Galaxies at z=2.3 have compact and irregular morphologies with no clearly evident Hubble-sequence candidates. The mean galaxy size grows from z=2.3 to 1 by 40%, and the density of galaxies larger than 3 kpc increases by 7 times. At z=1, the size-luminosity distribution is broadly consistent with that of local galaxies, with passive evolution. However, galaxies at z=2.3 are smaller than the large present-day galaxies, and must continue to grow in size and stellar mass. We have measured the galaxies' UV-optical ICD, which quantifies differences in morphology and the relative amount of on-going star-formation. The mean and scatter in galaxies' total colors and ICD increase from z=2.3 to 1. At z=1 many galaxies with large ICD are spirals, with a few irregular systems. Few z=2.3 galaxies have high ICD, and those that do are actively merging. We interpret this as evidence for the presence of older and more diverse stellar populations at z=1 that are not generally present at z>2. We conclude that the star-formation histories of galaxies at z>2 are dominated by discrete, recurrent bursts, which quickly homogenize the galaxies' stellar content, and are possibly associated with mergers. The increase in the stellar-population diversification by z<1.4 implies that merger-induced starbursts occur less frequently than at higher redshifts, and more quiescent star-forming modes dominate. This transition coincides with the emergence of Hubble-sequence galaxies. [Abridged]Comment: Accepted for publication in the Astrophysical Journal. 20 pages, in emulateapj forma

    The Internal Ultraviolet-to-Optical Color Dispersion: Quantifying the Morphological K-Correction

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    We present a quantitative measure of the internal color dispersion within galaxies, which quantifies differences in morphology as a function of wavelength. We apply this statistic to a local galaxy sample with archival images at 1500 and 2500 Angstroms from the Ultraviolet Imaging Telescope, and ground-based B-band observations to investigate how the color dispersion relates to global galaxy properties. The intenal color dispersion generally correlates with transformations in galaxy morphology as a function of wavelength, i.e., it quantifies the morphological K-correction. Mid-type spiral galaxies exhibit the highest dispersion in their internal colors, which stems from differences in the bulge, disk, and spiral-arm components. Irregulars and late-type spirals show moderate internal color dispersion, which implies that young stars generally dominate the colors. Ellipticals, lenticulars, and early-type spirals generally have low or negligible internal color dispersion, which indicates that the stars contributing to the UV-to-optical emission have a very homogeneous distribution. We discuss the application of the internal color dispersion to high-redshift galaxies in deep, Hubble Space Telescope images. By simulating local galaxies at cosmological distances, many of the galaxies have luminosities that are sufficiently bright at rest--frame optical wavelengths to be detected within the limits of the currently deepest near-infrared surveys even with no evolution. Under assumptions that the luminosity and color evolution of the local galaxies conform with the measured values of high-redshift objects, we show that galaxies' intrinsic internal color dispersion remains measurable out to z ~ 3.Comment: Accepted for publication in the Astrophysical Journal. 41 pages, 13 figures (3 color). Full resolution version (~8 Mb) available at http://mips.as.arizona.edu/~papovich/papovich_astroph.p

    Usability and feasibility of consumer-facing technology to reduce unsafe medication use by older adults

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    Background Mobile health technology can improve medication safety for older adults, for instance, by educating patients about the risks associated with anticholinergic medication use. Objective This study's objective was to test the usability and feasibility of Brain Buddy, a consumer-facing mobile health technology designed to inform and empower older adults to consider the risks and benefits of anticholinergics. Methods Twenty-three primary care patients aged ≥60 years and using anticholinergic medications participated in summative, task-based usability testing of Brain Buddy. Self-report usability was assessed by the System Usability Scale and performance-based usability data were collected for each task through observation. A subset of 17 participants contributed data on feasibility, assessed by self-reported attitudes (feeling informed) and behaviors (speaking to a physician), with confirmation following a physician visit. Results Overall usability was acceptable or better, with 100% of participants completing each Brain Buddy task and a mean System Usability Scale score of 78.8, corresponding to “Good” to “Excellent” usability. Observed usability issues included higher rates of errors, hesitations, and need for assistance on three tasks, particularly those requiring data entry. Among participants contributing to feasibility data, 100% felt better informed after using Brain Buddy and 94% planned to speak to their physician about their anticholinergic related risk. On follow-up, 82% reported having spoken to their physician, a rate independently confirmed by physicians. Conclusion Consumer-facing technology can be a low-cost, scalable intervention to improve older adults’ medication safety, by informing and empowering patients. User-centered design and evaluation with demographically heterogeneous clinical samples uncovers correctable usability issues and confirms the value of interventions targeting consumers as agents in shared decision making and behavior change

    Use of mental simulations to change theory of planned behaviour variables

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    Objectives. The predictive validity of the theory of planned behaviour iswell established, but much less is known about: (a) whether there are causal relationships between key components of the model and (b) how to go about changing the theory of planned behaviour variables. This study tested the ability of outcome and process simulations to change variables specified in the theory of planned behaviour in relation to blood donation. Design. Participants (N ¼ 146) were randomized to one of four conditions: outcome simulation only, process simulation only, process-plus-outcome simulation and a distractor control condition. The dependent variables were state anxiety, and intention attitude, subjective norm and perceived control from the theory of planned behaviour. Methods. Participants were asked to empty their mind and visualize themselves: (a) after donating blood (outcome manipulation), (b) preparing to donate blood (process manipulation), (c) both preparing to donate blood and after having donated blood (process-plus-outcome manipulation) or (d) both preparing to get a high mark and after having got a high mark on their course (control condition). Following mental rehearsal, participants completed the dependent variables. Results. There were no main effects of outcome simulation, but process simulation successfully increased intention, subjective norm and perceived control. There was also a significant outcome simulation x process simulation interaction for attitude. The effect of the process manipulation on intention was mediated by subjective norm and perceived control. Conclusions. The findings show promise for the use of mental simulations in changing cognitions and further research is required to extend the present findings to other health behaviours.</p

    7,7′-(3,3′-Dibenzyl-3H,3′H-4,4′-bi-1,2,3-triazole-5,5′-di­yl)bis­(4-methyl-2H-chromen-2-one)

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    The title compound, a bis-5,5′-triazole, C38H28N6O4, was observed as a side-product from the Sharpless–Meldal click reaction of the corresponding coumarin alkyne and benzyl­azide. Although the compound was present as a minor component, it crystallized in preference to the major product. The two triazole rings are almost orthogonal to each other [dihedral angle = 83.8 (1)°]. However the 4 and 4′ coumarin systems are close to coplanar with their respective triazole rings [23.6 (1) and 15.1 (1)°]. Each of the benzene rings packs approximately face-to-face with the opposing coumarin ring systems, with inter­planar angles of 7.7 (1) and 25.3 (1)° and distances of 3.567 (2) and 3.929 (2) Å between the respective centroids of the opposing rings
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