1,720,965 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
Antioxidants induce different phenotypes by a distinct modulation of signal transduction
No full textAntioxidants are known to exert a preventive activity against degenerative diseases. Here, we investigated the mechanism of action of three antioxidants: resveratrol, which causes differentiation of HL-60 cells, and hydroxytyrosol and pyrrolidine dithiocarbamate which, in the same model system, activate apoptosis. The expression profile of hydroxytyrosol-treated cells showed the up-regulation of several genes, including c-jun and egr1. Pyrrolidine dithiocarbamate activates both genes, while resveratrol increases uniquely egr1. A selective modulation of signalling pathway explained this finding. All antioxidants up-regulate Erk1/2, while only hydroxytyrosol and pyrrolidine dithiocarbamate activate c-Jun N-terminal kinase (JNK). Since JNK induces apoptosis by Bcl-2 phosphorylation, we investigated this event. Bcl-2 phosphorylation was increased by hydroxytyrosol and pyrrolidine dithiocarbamate and not by resveratrol. Our results indicate that the different phenotypical effects of antioxidants correlate with modulation of selective transduction pathways
p21Cip1 gene expression is modulated by Egr1: a novel regulatory mechanism involved in the resveratrol antiproliferative effect
Full text linkEpidemiological observations indicate that resveratrol, a natural antioxidant stilbene, exerts cardioprotective and chemopreventive effects. Moreover, the molecule induces in vitro cell growth inhibition and differentiation. Using human erythroleukemic K562 cells as model system, we demonstrated that resveratrol induces a remarkable gamma-globin synthesis, the erythroid differentiation being linked to impairment of cell proliferation, increased p21Cip1 expression and inhibition of cdk2 activity. The up-regulation of p21Cip1 transcription is prevented by cycloheximide, indicating the requirement of intermediate protein(s), which, in turn, regulate gene expression. The quantitative analysis of some transcription factors involved in the erythroid lineage, namely GATA-1, GATA-2, and Egr1, indicated that resveratrol selectively up-regulates Egr1 by an Erk1/2-dependent mechanism. The presence of an Egr1 consensus sequence in the p21Cip1 promoter suggested the hypothesis that this transcription factor directly regulates the expression of the cdk inhibitor. Transfection studies with deleted gene promoter constructs, as well as EMSA, pull-down, and chromatin immunoprecipitation experiments substantiated this view, demonstrating that Egr1 binds in vitro and in vivo to the identified consensus sequence of the p21Cip1 promoter. Moreover, an Egr1 phosphorothioate antisense hinders p21Cip1 accumulation and the antiproliferative effects of resveratrol. In conclusion, this is the first demonstration that Egr1 controls p21Cip1 expression by directly interacting with a specific sequence on its gene promoter. The identified regulatory mechanism also contributes to the clarification of the complex chemopreventive and antiproliferative properties of resveratrol
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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