1,720,978 research outputs found
The autonomic nervous system and chromaffin tissue: Neuroendocrine regulation of catecholamine secretion in non-mammalian vertebrates
No full textIf severe enough, periods of acute stress in animals may be associated with the release of
catecholamine hormones (noradrenaline and adrenaline) into the circulation; a response termed
the acute humoral adrenergic stress response. The release of catecholamines from the sites of
storage, the chromaffin cells, is under neuroendocrine control, the complexity of which appears
to increase through phylogeny. In the agnathans, the earliest branching vertebrates, the
chromaffin cells which are localised predominantly within the heart, lack neuronal innervation
and thus catecholamine secretion in these animals is initiated solely by humoral mechanisms. In
the more advanced teleost fish, the chromaffin cells are largely confined to the walls of the
posterior cardinal vein at the level of the head kidney where they are intermingled with the
steroidogenic interrenal cells. Catecholamine secretion from teleost chromaffin cells is regulated
by a host of cholinergic and non-cholinergic pathways that ensure sufficient redundancy and
flexibility in the secretion process to permit synchronized responses to a myriad of stressors.
The complexity of catecholamine secretion control mechanisms continues through the
amphibians, reptiles and birds although neural (cholinergic) regulation may become increasingly
important in birds. Discrete adrenal glands are present in the non-mammalian tetrapods but
unlike in mammals, there is no clear division of a steroidogenic cortex and a chromaffin cell
enriched medulla. However, in all groups, there is an obvious intermingling of chromaffin and
steroiodogenic cells. The association of the two cell types may be particularly important in the
amphibians and birds because like in mammals, the enzyme catalysing the methylation of
noradrenaline to adrenaline, PNMT, is under the control of the steroid, cortisol
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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