1,720,961 research outputs found
Targeting reactive astrogliosis by novel biotechnological strategies
No full textNeuroglial cells are fundamental for control of brain homeostasis and synaptic plasticity. Decades of pathological and physiological studies have focused on neurons in neurodegenerative disorders, but it is becoming increasingly evident that glial cells play an irreplaceable part in brain homeostasis and synaptic plasticity. Animal models of brain injury and neurodegenerative diseases have largely contributed to current understanding of astrocyte-specific mechanisms participating in brain function and neurodegeneration. Specifically, gliotransmission (presence of glial neurotransmitters, and their receptors and active transporters), trophic support (release, maturation and degradation of neurotrophins) and metabolism (production of lactate and GSH components) are relevant aspects of astrocyte function in neuronal metabolism, synaptic plasticity and neuroprotection. Morpho-functional changes of astrocytes and microglial cells after traumatic or toxic insults to the central nervous system (namely, reactive gliosis) disrupt the complex neuro-glial networks underlying homeostasis and connectivity within brain circuits. Thus, neurodegenerative diseases might be primarily regarded as gliodegenerative processes, in which profound alterations of glial activation have a clear impact on progression and outcomes of neuropathological processes. This review provides an overview of current knowledge of astrocyte functions in the brain and how targeting glial-specific pathways might ultimately impact the development of therapies for clinical management of neurodegenerative disorders
INFUSION OF ESCHERICHIA COLI LIPOPOLYSACCHARIDE TOXIN IN RATS PRODUCES AN EARLY AND SEVERE IMPAIRMENT OF BAROREFLEX FUNCTION IN ABSENCE OF BLOOD PRESSURE CHANGES
No full textThe assessment of baroreflex function since the first appearance of endotoxemia is important because the arterial baroreflex should exert a protective role during sepsis. Nevertheless, contrasting results were previously reported. This could be due to the hemodynamic instability characterizing this condition that may per se interfere with reflex cardiovascular adjustments. The aim of our study was therefore to study the baroreflex function (a) since the very beginning of infusion of Escherichia coli lipopolysaccharide (LPS) toxin and (b) in absence of the unloading effect produced by a decrease in blood pressure. Lipopolysaccharide was infused in 10 rats for 20 min at the infusion rate of 0.05 mg . kg(-1) . min(-1). Blood pressure was continuously measured before, during, and after infusion, and the baroreflex function was evaluated analyzing spontaneous fluctuations of systolic blood pressure and pulse interval by the sequence and transfer-function techniques. Plasma concentrations of inflammatory (interleukin 6, tumor necrosis factor alpha) and anti-inflammatory (interleukin 10) cytokines were measured in other eight rats, similarly instrumented, four of which receiving the same LPS infusion. We found that blood pressure levels did not change with the infusion of LPS, whereas inflammatory cytokines increased significantly. The baroreflex sensitivity was significantly reduced 10 min after the beginning of LPS infusion, reached values about half those at baseline within 15 min after the start of infusion, and remained significantly low after the end of infusion. In conclusion, we documented that septic shock inducing LPS infusion is responsible for a very rapid impairment of the baroreflex function, independent from the level of blood pressure
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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