1,048 research outputs found

    Інформаційні технології у сфері освіти - нові можливості, нові завдання

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    AbstractIn Limulus photoreceptors, light induces a depolarization. The gating mechanism of the cation channels involved is not understood but evidence exists that cyclic nucleotides may act as ligands. Using an antiserum against a cGMP-protein conjugate, we found strong immunoreactivity localized to the light-sensitive rhabdoms of lateral eye photoreceptors. In homogenated tissue, the cGMP concentration was on average 0.2 pmol/mg retinal tissue protein both in light- and dark-adapted eyes. Phosphodiesterase inhibitors caused a 2–3-fold increase in the cGMP level. Despite our failure to detect a light dependence of the cGMP concentration, these results support the proposed role of cGMP in Limulus phototransduction

    The analysis of randomised controlled trial data with more than one follow-up measurement. A comparison between different approaches.

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    When more than one follow-up measurement is analysed in a randomized controlled trial, there is no consensus how to analyse the overall intervention effect in a proper way. Mostly, longitudinal analysis of covariance is used, because with this method a correction is made for possible regression to the mean. However, in this paper it is shown that this method (mostly) leads to an overestimation of the intervention effect. A possible solution is the use of autoregression, although this does not seem to be the best solution, because it leads to an overcorrection. Due to these flaws, in this paper a new approach is introduced in which a correction for the baseline value is made for the first follow-up, but no correction is made for the remaining follow-up measurements

    Challenging parenting behavior from infancy to toddlerhood: Etiology, measurement, and differences between fathers and mothers

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    Based on evidence that fathers show more challenging and physical play than mothers, it has been theorized that fathers have a different parenting role, more focused at stimulating exploration and taking chances. Challenging parenting behavior (CPB) may foster confidence and buffer against anxiety development in children. In this study, CPB was assessed in fathers and mothers at child ages of 4 months, 1 year, and 2.5 years, using newly developed questionnaires and observational tasks. Reliability of the questionnaire and observational measures was good, and fathers' and mothers' self-rated CPB showed a similar factor structure. Modest and significant convergence between questionnaires and observations provided support for validity of CPB, whereas negative correlations with overprotection supported divergent validity. CPB correlated positively with warmth. We further found moderate to high stability of CPB from early infancy to toddlerhood, and interparental correspondence in CPB. Fathers and mothers did not differ in observed CPB, but fathers rated themselves higher than mothers in toddlerhood. It is concluded that the development of the instruments to assess CPB was successful. Overall, the results reveal similarities rather than differences between fathers' and mothers' CPB in early childhood. The potential relevance of CPB in child development and psychopathology is discussed

    Fathers’ challenging parenting behavior predicts less subsequent anxiety symptoms in early childhood

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    Recent theories propose that (especially fathers’) challenging parenting behavior (CPB) serves to reduce offspring's anxiety development, and that fearful children are more susceptible to parenting. Using a longitudinal design we explored whether more CPB (and less overprotection) of both parents, (1) separately, (2) relatively, and (3) jointly predicts less anxiety in early childhood, and (4) whether child fearful temperament moderates these relations. Participants were 132 couples with their first-born child. Child fearful temperament was observed at 4 months and 1 year, and parents’ CPB and overprotection at 1 and 2.5 years. Child anxiety symptoms were assessed at 2.5 and 4.5 years. Multilevel analyses showed that more CPB and, unexpectedly, more overprotection predicted less child anxiety. Relatively, fathers’ CPB and mothers’ overprotection predicted less anxiety. An interaction showed that if one parent shows low CPB, the other parent's higher CPB predicts less child anxiety. A trend interaction suggested that fathers’ CPB predicts less anxiety most strongly for fearful children. Thus, fathers’ CPB appears to play a protective role in anxiety development, possibly in particular for children most vulnerable to develop anxiety problems. Parents can compensate for a less challenging partner. The finding that maternal overprotection mitigates child anxiety requires further investigation

    Autonomic arousal in children of parents with and without Social Anxiety Disorder:A high-risk study

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    Objective Autonomic hyperarousal in social situations is considered a genetic vulnerability factor for social anxiety disorder (SAD), but so far it is unstudied in children at risk for developing SAD. We examined autonomic activity during socially stressful tasks in children of mothers and fathers with and without lifetime SAD to reveal possible biological mechanisms of intergenerational transmission of SAD. Methods One hundred ten children aged 4.5 years were asked to sing a song in front of an audience and watch back their performance in the presence of that audience. Heart rate (HR), heart rate variability (HRV), electrodermal activity (EDA), and blushing (cheek blood flow and temperature) were measured in anticipation of, during, and after the tasks. Both parents’ lifetime SAD status was assessed, and both parents reported about their own and their child's social anxiety symptoms. Results Children of parents with lifetime SAD blushed more during the socially challenging tasks than children of parents without SAD. Moreover, children of parents with more social anxiety symptoms showed increased EDA throughout the tasks. Finally, more blushing, increased EDA, and reduced HRV were associated with greater child social anxiety. Conclusions This study adds to the current knowledge on the intergenerational transmission of SAD by providing evidence that children at risk for SAD are characterized by excessive blushing in socially challenging situations. The findings also demonstrate that heightened autonomic activity is a characteristic of social anxiety already during early childhood. Hence, autonomic hyperarousal, and blushing in particular, is likely to play an etiological role in the development of SAD

    Should we use logistic mixed model analysis for the effect estimation in a longitudinal RCT with a dichotomous outcome variable?

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    Background: Within epidemiology both mixed model analysis and Generalised Estimating Equations (GEE analysis) are frequently used to analyse longitudinal RCT data. With a continuous outcome, both methods lead to more or less the same results, but with a dichotomous outcome the results are totally different. The purpose of the present study is to evaluate the performance of a logistic mixed model analysis and a logistic GEE analysis and to give an advice which of the two methods should be used. Methods: Two real life RCT datasets with and without missing data were used to perform this evaluation. Regarding the logistic mixed model analysis also two different estimation procedures were compared to each other. Results: The regression coefficients obtained from the two logistic mixed model analyses were different from each other, but were always higher then the regression coefficients derived from a logistic GEE analysis. Because this also holds for the standard errors, the corresponding p-values were more or less the same. It was further shown that the effect estimates derived from a logistic mixed model analysis were an overestimation of the ‘real’ effect estimates. Conclusions:  Although logistic mixed model analysis is widely used for the analysis of longitudinal RCT data, this article shows that logistic mixed model analysis should not be used when one is interested in the magnitude of the regression coefficients (i.e. effect estimates)

    Physical activity, mindfulness meditation, or heart rate variability biofeedback for stress reduction: a randomized controlled trial

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    In contemporary western societies stress is highly prevalent, therefore the need for stress-reducing methods is great. This randomized controlled trial compared the efficacy of self-help physical activity (PA), mindfulness meditation (MM), and heart rate variability biofeedback (HRV-BF) in reducing stress and its related symptoms. We randomly allocated 126 participants to PA, MM, or HRV-BF upon enrollment, of whom 76 agreed to participate. The interventions consisted of psycho-education and an introduction to the specific intervention techniques and 5 weeks of daily exercises at home. The PA exercises consisted of a vigorous-intensity activity of free choice. The MM exercises consisted of guided mindfulness meditation. The HRV-BF exercises consisted of slow breathing with a heart rate variability biofeedback device. Participants received daily reminders for their exercises and were contacted weekly to monitor their progress. They completed questionnaires prior to, directly after, and 6 weeks after the intervention. Results indicated an overall beneficial effect consisting of reduced stress, anxiety and depressive symptoms, and improved psychological well-being and sleep quality. No significant between-intervention effect was found, suggesting that PA, MM, and HRV-BF are equally effective in reducing stress and its related symptoms. These self-help interventions provide easily accessible help for people with stress complaints
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