1,720,971 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
Bovine lactoferrin peptidic fragments involved in inhibition of herpes simplex virus type 1 infection
No full textBovine lactoferrin (BLf) prevents the infection of some enveloped and naked viruses, To identify BLf sequences responsible for the antiviral activity, we tested 31 HPLC fractions, derived from tryptic digestion of BLf, toward herpes simplex virus type 1 (HSV-1). Only a few HPLC purified fragments were active against HSV-1, even if at lower extent than the native undigested BLf, Two large fragments, one corresponding to the C-lobe (amino acid sequence 345-689) and the other corresponding to a large portion of the N-lobe (1-280), were inhibitors of HSV-1 infection, while a smaller part of the N-lobe (86-258) was ineffective. Among the low-molecular-weight fragments, only two small peptides, which coeluted in a single chromatographic peak, were effective towards HSV-1. These peptides, both present in the N-lobe, were identified as peptides 222-230 (ADRDQYELL) and 264-269 (EDLIWK). The same peptides, chemically synthesised, were able to inhibit HSV-1 infection only when they were assayed in association. (C) 1999 Academic Press
Lactoferrin inhibits herpes simplex virus type 1 adsorption to Vero cells
No full textThis paper describes the ability of human and bovine lactoferrins (HLf; BLf), iron-binding proteins belonging to the non-immune defense system, to interfere with herpes simplex virus type 1 (HSV-1) infection. Since lactoferrins are known to bind to heparan sulphate proteoglycans and to low density lipoprotein receptor, which in turn act as binding sites for the initial interaction of HSV-1 with host cells, we tested the effect of these proteins on HSV-1 multiplication in Vero cells. Both HLf and BLf are found to be potent inhibitors of HSV-1 infection, the concentrations required to inhibit the viral cytopathic effect in Vero cells by 50% being 1.41 mu M and 0.12 mu M, respectively. HLf and BLf exerted their activity through the inhibition of adsorption of virions to the cells independently of their iron withholding property showing similar activity in the apo- and iron-saturated form. The binding of [S-35]methionine-labelled HSV-1 particles to Vero cells was strongly inhibited when BLf was added during the attachment step. BLf interacts with both Vero cell surfaces and HSV-1 particles, suggesting that the hindrance of cellular receptors and/or of viral attachment proteins may be involved in its antiviral mechanism
Antiadenovirus activity of milk proteins: lactoferrin prevents viral infection
No full textDifferent milk proteins were analysed for their inhibitory effect on adenovirus infection in vitro. Proteins investigated were mucin, alpha-lactalbumin, beta-lactoglobulin, bovine lactoferrin, and human lactoferrin. Results obtained demonstrated that mucin, alpha-lactalbumin, and beta-lactoglobulin did not prevent the viral cytopathic effect, whereas lactoferrin was able to inhibit adenovirus replication in a dose-dependent manner. Further experiments were carried out in which lactoferrin was added to the cells during different phases of viral infection. Results obtained showed that lactoferrin was able to prevent viral replication when added both before, or during the viral adsorption step, or when present during the entire replicative cycle of adenovirus, demonstrating that its action takes place on an early phase of viral replication, (C) 2002 Elsevier Science B.V. All rights reserved
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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