1,720,993 research outputs found
Environmental enrichment during adolescence reverses the effects of prenatal stress on play behaviour and HPA axis reactivity in rats
No full textPrenatal stress (PS) can produce profound and long-lasting perturbations of individual adaptive capacities, which in turn can result in an increased proneness to behavioural disorders. Indeed, in PS rats there is evidence of impaired social play behaviour, disturbances in a variety of circadian rhythms, enhanced anxiety and increased hypothalamic-pituitary-adrenal (HPA) axis reactivity. This study was designed to experimentally investigate the degree of reversibility of PS-induced disturbances of social play and HPA reactivity by assessing the effect of the enrichment of the physical environment on PS rats during periadolescence. PS subjects showed a reduced expression of social play behaviour and a prolonged corticosterone secretion in response to restraint stress, but both these effects were markedly reversed following environmental enrichment. Interestingly, the enrichment procedure increased social behaviour but had no effect on corticosterone secretion in nonstressed animals, indicating a differential impact of the postnatal environment as a function of prenatal background. As a whole, results clearly indicate that rats prenatally exposed to stress can benefit during periadolescence from the modulatory effects of an enriched environment. Moreover, they confirm that PS may well represent a suitable animal model for the design and testing of new therapeutic strategies for behavioural disorders produced by early insults
Social withdrawal, neophobia, and stereotyped behavior in developing rats exposed to neonatal asphyxia
No full textPerinatal asphyxia is a concern for public health and may promote subtle neuropsychiatric disorders. Anoxic insults to neonatal rats cause long-lasting neurobehavioral deficits. In the present study, we focussed on changes in emotional behaviors as a consequence of neonatal asphyxia in Wistar rats. Newborn pups (24 h after birth) underwent a single 30-min exposure to a 100% N2 atmosphere (or air). The offspring was tested for a) locomotor and exploratory activity with or without a d-amphetamine challenge (0, 1, or 2 mg/kg) on postnatal day (pnd) 15; b) social interactions and novelty seeking during adolescence; c) levels of the brain-derived neurotrophic factor (BDNF). In the open-field test (pnd 15), N2-exposed pups injected with the high (2 mg/kg) amphetamine dose exhibited reduced levels of locomotor hyperactivity, and a more marked involvement in stereotyped behaviors. Individual differences emerged in the locomotor response to the novelty-seeking test: two subgroups of rats (separated on the basis of the median value) showed either arousal/attraction or avoidance/inhibition in response to free-choice novelty. The N2-exposed group showed a more marked novelty-induced avoidance and inhibition. Time devoted to allogrooming and play-soliciting behaviors was reduced, whereas object exploration was increased. Levels of BDNF were reduced in the striatum of N2-exposed rats, suggesting poorer synaptic performance of dopamine pathways. In conclusion, these findings suggest an increased risk of developing social withdrawal, neophobia and behavioral stereotypies (common symptoms found in schizophrenia and autism) as a consequence of neonatal asphyxia in preterm humans. © Springer-Verlag 2004
L’ADHD e l’intervento multimodale/ ADHD and multimodal intervention.
No full textDuring the year 2003, the National Register of the Attention deficit hyperactivity disorder (ADHD) has been implemented in Italy. It was commissioned by the Ministry of Health to the Istituto Superiore di Sanità, which is its leading technical and scientific body, with the aim to set up a sound database gathering detailed information on the prescription of Ritalin at the national level. The latter represents the most diffused elective drug treatment for such an early-onset neuropsychiatric syndrome. To this aim, the more prevalent theories on the pathogenesis of ADHD and the debate on therapy are reviewed and discussed. This paper is aimed at emphasizing that this kind of systematic data gathering of such a Register has not to be meant an unconditional approval of a therapeutical approach based on drug therapy only. Pharmacological therapies may or may not be included within the frame of a multimodal complex treatment plan which should also rely on psychological intervention
D-amphetamine-related reinforcing effects are reduced in mice exposed prenatally to estrogenic endocrine disrupters
No full textGoing 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
Dispelling 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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