125 research outputs found

    Light scattering spectra of supercooled molecular liquids

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    The light scattering spectra of molecular liquids are derived within a generalized hydrodynamics. The wave vector and scattering angle dependences are given in the most general case and the change of the spectral features from liquid to solidlike is discussed without phenomenological model assumptions for (general) dielectric systems without long-ranged order. Exact microscopic expressions are derived for the frequency-dependent transport kernels, generalized thermodynamic derivatives and the background spectra.Comment: 12 page

    The Prospective Association Between Electronic Device Use Before Bedtime and Academic Attainment in Adolescents

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    © 2018 Elsevier Ltd Purpose: To examine longitudinal associations between five commonly used technology devices prior to bedtime and real-life academic outcomes in adolescents. Methods: A total of 853 adolescents were recruited to a three-year prospective cohort study, with annual assessments. Academic grades/levels for three core subjects (English, Mathematics, and Science) were extracted from school records, and standardized (z-scores) were derived at the end of each academic year. A validated questionnaire was used to determine the frequency of using five types of technology (television viewing, video gaming, mobile telephone use, listening to music, and social networking) before bedtime. Results: After adjustment, English attainment was the subject most affected by prebedtime technology use, where three of five technologies assessed were negatively and prospectively associated (social networking [β = −.07 and p =.024], video gaming [β = −.10 and p =.008], and mobile telephone [β = −.07 and p=.017]). Social networking (β = −.07and p =.042), television viewing (β = −.08 and p =.044), and mobile telephones (β = −.07 and p =.031) were associated with significant impairment in English for girls whereas attainment in boys was most impaired by video gaming (β = −.12 and p =.014). Conclusions: The use of electronic devices by adolescents before bedtime may reduce their academic attainment, but apart from video gaming for boys, the negative impact of near bedtime technology use on academic performance is small

    Positive and negative evaluation of caregiving among three different types of informal care relationships

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    Based on the caregiver stress model, we examined how care demands, caregiver motivation, coping style and external support are associated with positive evaluation and caregiver burden among spousal, adult child and other types of care relations. Data from a sample of Dutch informal caregivers of 1,685 older persons (55 and older) were analyzed employing multivariate linear regression analyses for each of the care relationship types. Spouses (N = 206) report high positive evaluation and high burden, adult children (N = 1,093) report low positive evaluation, and other caregivers (N = 386) report high positive evaluation and a low burden. Multivariate linear regression analyses showed that motives and external support were important for positive evaluation but the impact varied among types of caregivers, whereas care demands and not asking for help were associated with burden for all types. Only among 'other' caregiver relationships, positive evaluation was negatively associated with burden. It is concluded that results confirm the dual nature of caregiving among spouses and children. The care context and motivation of the different types of caregivers explain their differences in care evaluation. Various interventions for types of caregivers are discussed. © 2013 Springer-Verlag Berlin Heidelberg

    Prokineticin 2 Regulates the Electrical Activity of Rat Suprachiasmatic Nuclei Neurons

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    Neuropeptide signaling plays roles in coordinating cellular activities and maintaining robust oscillations within the mammalian suprachiasmatic nucleus (SCN). Prokineticin2 (PK2) is a signaling molecule from the SCN and involves in the generation of circadian locomotor activity. Prokineticin receptor 2 (PKR2), a receptor for PK2, has been shown to be expressed in the SCN. However, very little is known about the cellular action of PK2 within the SCN. In the present study, we investigated the effect of PK2 on spontaneous firing and miniature inhibitory postsynaptic currents (mIPSCs) using whole cell patch-clamp recording in the SCN slices. PK2 dose-dependently increased spontaneous firing rates in most neurons from the dorsal SCN. PK2 acted postsynaptically to reduce γ-aminobutyric acid (GABA)-ergic function within the SCN, and PK2 reduced the amplitude but not frequency of mIPSCs. Furthermore, PK2 also suppressed exogenous GABA-induced currents. And the inhibitory effect of PK2 required PKC activation in the postsynaptic cells. Our data suggest that PK2 could alter cellular activities within the SCN and may influence behavioral and physiological rhythms

    An examination of the self-referent executive processing model of test anxiety: control, emotional regulation, self-handicapping, and examination performance

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    According to the self-referent executive processing (S-REF) model, test anxiety develops from interactions between three systems: executive self-regulation processes, self-beliefs, and maladaptive situational interactions. Studies have tended to examine one system at a time, often in conjunction with how test anxiety relates to achievement outcomes. The aim of this study was to enable a more thorough test of the S-REF model by examining one key construct from each of these systems simultaneously. These were control (a self-belief construct), emotional regulation through suppression and reappraisal (an executive process), and self-handicapping (a maladaptive situational interaction). Relations were examined from control, emotional regulation, and self-handicapping to cognitive test anxiety (worry), and subsequent examination performance on a high-stakes test. Data were collected from 273 participants in their final year of secondary education. A structural equation model showed that higher control was indirectly related to better examination performance through lower worry, higher reappraisal was indirectly related to worse examination performance through higher worry, and higher self-handicapping was related to worse examination performance through lower control and higher worry. These findings suggest that increasing control and reducing self-handicapping would be key foci for test anxiety interventions to incorporate. © 2018 The Author(s
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