1,721,193 research outputs found
Vasopressinergic modulation of stress responses in the central amygdala of the Roman high-avoidance and low-avoidance rat
Full text linkThe central nucleus of the amygdala (CEA) is selectively involved in the passive component of the behavioral (immobility) and the accompanying parasympathetic response during conditioned, stressful environmental challenges. Vasopressinergic mechanisms in the brain seem to play a role in these stress responses. The effects of the neuropeptides arginine-8-vasopressin (AVP) and oxytocin (OXT) on modulating CEA activity during conditioned stress of inescapable footshock were studied in male Roman high-avoidance (RHA/Verh) and low-avoidance (RLA/Verh) rats, psychogenetically selected on the basis of shuttle-box acquisition behavior. In RLA/Verh rats, the cardiac and behavioral responses to the conditioned emotional stressor were bradycardia and immobility, suggesting an important role for the CEA in these rats. The RHA/Verh rats, however, failed to show any change in heart rate or immobility in response to a conditioned stress situation. The low dose of AVP (20 pg) in the CEA of conscious RLA/Verh rats caused an enhancement of the stress-induced bradycardiac and immobility response. However, the high dose of AVP (2 ng) and OXT (200 pg) attenuated the bradycardiac and immobility responses in the RLA/Verh rats. Infusion of AVP and OXT in the RHA/Verh rats failed to induce any change in heart rate nr immobility. Binding studies revealed that the AVP receptor selectively binds AVP with high affinity. In contrast, the OXT receptor recognizes both AVP and OXT with a similar (but lower) affinity. This suggests that the behavioral and autonomic responses of the high dose of AVP may be caused by OXT receptor stimulation. In conclusion, on the basis of the present results one may hypothesize that CEA differences in AVP and OXT innervation and/or receptor densities may contribute to the differences in coping strategy found in these animals.
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
Vasopressin Prolongs Behavioral and Cardiac Responses to Mild Stress in Young But Not in Aged Rats
Full text linkIn young male Wistar rats sudden silence superimposed on low intensity background noise evokes a relative decrease in heart rate. This bradycardia is accompanied by immobility behavior. In the present study, involving young (3 month), late-adult (14 month), aged (20 month), and senescent (25 month) rats the magnitude of the stress-induced bradycardia shows an age-related reduction while the behavioral immobility response remained unchanged during the process of aging. Arginine-8-vasopressin (AVP, 6 µg/kg SC) administered 60 min prior to the experiment led to a prolonged behavioral and cardiac stress response in young and late-adult rats, but not in aged and senescent animals. The peripheral and central mechanisms possibly involved in the failure of systemically applied AVP to improve bradycardiac stress responses in aged rats 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
Electrocardiographic and plasma catecholamine responses to social defeat and restraint stress in wild type rats.
No full textThe hypothalamo-pituitary-adrenal axis in the adult rat after perinatal hormonal manipulation
No full textLong-term effects of social defeat on the neuroendocrine response to corticotropin-releasing factor in rats.
No full textDispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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