5,225 research outputs found

    Do changes in drinking motives mediate the relation between personality change and maturing out of problem drinking?

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    Recent research has indicated that developmental changes in the personality traits of neuroticism and impulsivity correlate with changes in problem drinking during emerging and young adulthood. However, it remains unclear what potential mechanisms, or mediators, could account for these associations. Drinking motives, particularly drinking to regulate negative affect (drinking to cope) and to get “high” or “drunk” (drinking for enhancement) have been posited to mediate the relationship between personality and drinking problems. Recent work indicates changes in drinking motives parallel changes in alcohol involvement from adolescence to young adulthood. The current study examined changes in drinking motives (i.e., coping and enhancement) as potential mediators of the relation between changes in personality (impulsivity and neuroticism) with changes in alcohol problems in emerging and young adulthood. Analyses were based on data collected from a cohort of college students (N=489) at varying risk for AUDs from ages 18–35. Parallel process latent growth modeling indicated that change in coping (but not enhancement) motives specifically mediated the relation between changes in neuroticism and alcohol problems as well as the relation between changes in impulsivity and alcohol problems. Findings suggest that change in coping motives is an important mechanism in the relation between personality change and the “maturing out” of problematic alcohol involvement

    Behavioral conservatism is linked to complexity of behavior in chimpanzees (<i>Pan troglodytes</i>):implications for cognition and cumulative culture

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    Cumulative culture is rare, if not altogether absent in nonhuman species. At the foundation of cumulative learning is the ability to modify, relinquish, or build upon previous behaviors flexibly to make them more productive or efficient. Within the primate literature, a failure to optimize solutions in this way is often proposed to derive from low-fidelity copying of witnessed behaviors, suboptimal social learning heuristics, or a lack of relevant sociocognitive adaptations. However, humans can also be markedly inflexible in their behaviors, perseverating with, or becoming fixated on, outdated or inappropriate responses. Humans show differential patterns of flexibility as a function of cognitive load, exhibiting difficulties with inhibiting suboptimal behaviors when there are high demands on working memory. We present a series of studies on captive chimpanzees that indicate that behavioral conservatism in apes may be underlain by similar constraints: Chimpanzees showed relatively little conservatism when behavioral optimization involved the inhibition of a well-established but simple solution, or the addition of a simple modification to a well-established but complex solution. In contrast, when behavioral optimization involved the inhibition of a well-established but complex solution, chimpanzees showed evidence of conservatism. We propose that conservatism is linked to behavioral complexity, potentially mediated by cognitive resource availability, and may be an important factor in the evolution of cumulative culture.</p

    Igniting the spread of ferroptotic cell death

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    Sensitivity to speech rhythm explains individual differences in reading ability independently of phonological awareness

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    This study considered whether sensitivity to speech rhythm can predict concurrent variance in reading attainment after individual differences in age, vocabulary and phonological awareness have been controlled. Five to six-year-old English-speaking children completed a battery of phonological processing assessments and reading assessments, along with a simple word stress manipulation task. The results showed that performance on the stress manipulation measure predicted a significant amount of variance in reading attainment after age, vocabulary, and phonological processing had been taken into account. These results suggest that stress sensitivity is an important, yet neglected aspect of English-speaking children?s phonological representations, which needs to be incorporated into theoretical accounts of reading development

    Characterizing quantum dynamics with initial system-environment correlations

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    We fully characterize the reduced dynamics of an open quantum system initially correlated with its environment. Using a photonic qubit coupled to a simulated environment we tomographically reconstruct a superchannel---a generalised channel that treats preparation procedures as inputs---from measurement of the system alone, despite its coupling to the environment. We introduce novel quantitative measures for determining the strength of initial correlations, and to allow an experiment to be optimised in regards to its environment.Comment: 10 pages, 15 figure

    Evolution and impact of defects in a p-channel CCD after cryogenic proton-irradiation

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    P-channel CCDs have been shown to display improved tolerance to radiation-induced charge transfer inefficiency (CTI) when compared to n-channel CCDs. However, the defect distribution formed during irradiation is expected to be temperature dependent due to the differences in lattice energy caused by a temperature change. This has been tested through defect analysis of two p-channel e2v CCD204 devices, one irradiated at room temperature and one at a cryogenic temperature (153K). Analysis is performed using the method of single trap pumping. The dominant charge trapping defects at these conditions have been identified as the donor level of the silicon divacancy and the carbon interstitial defect. The defect parameters are analysed both immediately post irradiation and following several subsequent room-temperature anneal phases up until a cumulative anneal time of approximately 10 months. We have also simulated charge transfer in an irradiated CCD pixel using the defect distribution from both the room-temperature and cryogenic case, to study how the changes affect imaging performance. The results demonstrate the importance of cryogenic irradiation and annealing studies, with large variations seen in the defect distribution when compared to a device irradiated at room-temperature, which is the current standard procedure for radiation-tolerance testing

    Scaled von Mises-Fisher distributions and regression models for paleomagnetic directional data

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    We propose a new distribution for analysing paleomagnetic directional data that is a novel transformation of the von Mises-Fisher distribution. The new distribution has ellipse-like symmetry, as does the Kent distribution; however, unlike the Kent distribution the normalising constant in the new density is easy to compute and estimation of the shape parameters is straightforward. To accommodate outliers, the model also incorporates an additional shape parameter which controls the tail-weight of the distribution. We also develop a general regression model framework that allows both the mean direction and the shape parameters of the error distribution to depend on covariates. The proposed regression procedure is shown to be equivariant with respect to the choice of coordinate system for the directional response. To illustrate, we analyse paleomagnetic directional data from the GEOMAGIA50.v3 database (Brown et al. 2015). We predict the mean direction at various geological 1 time points and show that there is significant heteroscedasticity present. It is envisaged that the regression structures and error distribution proposed here will also prove useful when covariate information is available with (i) other types of directional response data; and (ii) square-root transformed compositional data of general dimension
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