1,721,108 research outputs found
Early life origin of adult insomnia: does prenatal-postnatal stress play a role?
No full textInsomnia is very common in the adult population and it includes a wide spectrum of sequelae, that is, neuroendocrine and cardiovascular alterations as well as psychiatric and neurodegenerative disorders. According to the conceptualization of insomnia in the context of the 3-P model, the importance of predisposing, precipitating, and perpetuating factors has been stressed. Predisposing factors are present before insomnia is manifested and they are hypothesized to interact with precipitating factors, such as environmental stressful events, contributing to the onset of insomnia. Understanding the early-life origins of insomnia may be particularly useful in order to prevent and treat this costly phenomenon. Based on recent evidence, prenatal-early-life stress exposure results in a series of responses that involve the stress system in the child and could persist into adulthood. This may encompass an activation of the hypothalamic-pituitary-adrenal axis accompanied by long-lasting modifications in stress reactivity. Furthermore, early-life stress exposure might play an important role in predisposing to a vulnerability to hyperarousal reactions to negative life events in the adult contributing to the development of chronic insomnia. Epigenetic mechanisms may also be involved in the development of maladaptive stress responses in the newborn, ultimately predisposing to develop a variety of (psycho-) pathological states in adult life
Long-lasting consequences of a social conflict in rats: behavior during the interaction predicts subsequent changes in daily rhythms of heart rate, temperature, and activity
No full textThis study shows that the long-term consequences of a social conflict in rats do not depend on the physical intensity of the fight in terms of aggression received but, especially, on how the subjects deal with it. Experimental rats were introduced into the cage of an aggressive conspecific for 1 hr, and the effects on daily rhythms of heart rate, body temperature, and activity thereafter were measured by means of telemetry. In some rats, the confrontation caused a strong decrease in the daily rhythm amplitude that lasted up to 3 weeks, whereas other subjects showed only minor changes. The changes in rhythm amplitude did not correlate with the number of attacks received from the territory owner. Contrary to this, the changes showed a clear negative correlation with the aggression of the experimental rats themselves. Subjects fighting back and counterattacking the cage owner subsequently had a smaller reduction in rhythm amplitude
Animal Models of Social Stress: Implications for the Study of Stress Related Pathologies in Humans
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Social stress in rats and mice
No full textThis paper summarizes some of the highlights of our current social stress research in rodents as it was inspired by the work of Jim Henry. First, it is argued that social defeat can be considered as one of the most severe stressors among a number of laboratory stressful stimuli in terms of neuroendocrine activation. Moreover, the stress response induced by defeat in particular is characterized by a strong sympathetic dominance. Depending on the stress parameter, the stress response induced by a single social defeat may last from hours to days and weeks. As a long term consequence of a single defeat experience, the animal becomes sensitized to subsequent minor stressors. Finally, the importance of individual differences in coping style in relation to stress vulnerability is discussed
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