1,721,051 research outputs found
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
Differential modulation of insulin actions by dexamethasone: studies in primary cultures of adult rat hepatocytes
No full textBackground/Aims: Steroid diabetes is associated with hepatic insulin resistance; in hepatic cell models, however, mainly insulin-permissive effects have been described. Here we investigate modulation by dexamethasone of a larger number of insulin actions. Methods: Adult rat hepatocytes were cultured dexamethasone for 48 h; insulin actions were studied subsequently. Results: Stimulation of glycolysis by insulin but not by glucose required culture with dexamethasone. Activation of glycogen synthesis by insulin or glucose was strongly enhanced by dexamethasone, the insulin effects on glycogenolysis and amino acid uptake were not modulated. When dexamethasone was omitted from the culture, insulin was incapable to activate glycogen synthase, inactivate glycogen phosphorylase or elevate the level of fructose 2,6-bisphosphate. Dexamethasone did not alter insulin binding, insulin receptor number or kinase activity, insulin receptor substrate-1 and Akt protein expression/phosphorylation. Insulin-stimulated association of phosphatidylinositol 3-kinase with insulin receptor substrates-1 and -2 was increased with dexamethasone, the increased association with IRS-2 may, at least partially, be explained by higher IRS-2 protein expression. Conclusions: The steroid does not cause hepatic resistance in vitro. The differential attenuation under steroid deprivation points to defects in branches of the insulin signal chain and/or loss of hormonal regulation at the level of target enzymes. (C) 2002 European Association for the Study of the Liver. Published by Elsevier Science B.V. All rights reserved
Hepatocyte-supported serum-free culture of rat liver sinusoidal endothelial cells
No full textBackground/Aims: A major problem in rat liver endothelial cell culture is the rapid loss of cells after 48 h, This study aimed to develop a protocol that allowed easy maintenance and proliferation of sinusoidal endothelial cells in serum-free culture for 5-6 days. Methods: Cells isolated from adult rat liver by collagenase digestion were purified by centrifugal elutriation and cultured on glutaraldehyde-crosslinked collagen, Results: At high plating densities cells could be maintained serum-free for 6 days in the presence of hydrocortisone and basic fibroblast growth factor; at lower plating densities medium had to be supplemented with additional growth-promoting factors. Conditioned medium of adult rat hepatocytes proved to be the most effective growth stimulus; it increased thymidine incorporation, DNA content and cell number per dish with a half-maximal effect at 20% (v/v), Cell proliferation was also observed with either vascular endothelial growth factor, phorbol ester or conditioned media from FAO or HEPG2 liver cell lines provided the cultures were additionally supplemented with 1% newborn calf serum. Vascular endothelial growth factor was detected in all conditioned media. In the absence of hepatocyte-conditioned medium, 1% serum helped to maintain cultures; it itself exerted a low proliferative effect. Higher serum concentrations (>5%), however, led to cell loss after 48 h, The numerous sieve plates of 6-h-old cells progressively disappeared during culture and were replaced by randomly distributed pores, which later grouped together at cell-cell borders. More than 90% of the cells endocytosed acetylated low-density lipoprotein, Conclusions: The study shows that cultured hepatocytes secrete growth-promoting substances that stimulate in vitro endothelial cell proliferation in the absence of serum; this effect could be mimicked by the combined addition of vascular endothelial growth factor and 1% serum. The new media formulations should facilitate future research on liver endothelial cells in mono- or coculture
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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