1,721,046 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
HCV AND lymphoma: Genetic and epigenetic factors
No full textOver 180 million people worldwide are chronically infected with the hepatitis C virus (HCV). HCV infection is a major cause for hepatocellular carcinoma (HCC), moreover the association with B-cell lymphoproliferative disorders (LPDs) like mixed cryoglobulinemia (MC) or B-cell non-Hodgkin lymphoma (B-NHL) is undisputed.
The mechanisms by which HCV contributes to LPD development are still poorly understood. Available data suggest that the viral infection may induce LPDs through a multifactorial and multistep process that involves the sustained activation of B cells, the abnormal and prolonged B cell survival, and genetic and/or epigenetic factors.
Concerning genetic factors, different authors reported an association between specific HLA clusters or B-cell activating factor promoter genotype and a higher risk of developing MC and lymphoma. In addition, the results of a large, ongoing genome wide association study (GWAS) will probably allow the identification of specific genetic profile of HCV patients with LPDs.
Furthermore, microRNAs (miRNAs) can give a major contribution to the pathogenesis of several neoplastic, lymphoproliferative diseases and it is conceivable their involvement in the pathogenesis of HCV-related LPDs.
We recently showed that specific miRNAs were differently modulated in PBMCs from HCV patients who developed MC and/or NHL. In addition, HCV patients who developed HCC, showed a differential miRNAs regulation.
In conclusion, available data suggest that the genetic/epigenetic analysis of HCV-related cancerogenesis is of great usefulness in both the pathogenetic and clinical/translational areas possibly allowing the definition of diagnostic/prognostic markers for early detection of lymphatic or hepatic cancer
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
Circadian pattern of serum leptin and beta-endorphin levels in obese and non obese women
No full textTo investigate diurnal profile of leptin and P-endorphin circulating levels and to assess any possible influence between these two peptides, 24-h serum concentrations of leptin and P-endorphin were examined in 24 obese (BMI 32. +/- 1 1.3) women and in 12 controls (BMI 21 +/- 0.5). Blood samples for leptin and P-endorphin determinations were drawn every four hours for 24 hours beginning at 8.00 am. Data were analyzed by unpaired t-test, linear regression and by inferential statistical procedures. We found a significant circadian rhythm for both peptides, either in obese or in controls. The 24-h mean leptin levels were significantly (p < 0.0001) higher (32.1 &PLUSMN; 2.8 ng/ml; mean &PLUSMN; SE) in obese women than controls (13.6 &PLUSMN; 1. 1), with a peak time located after midnight in obese and controls. The 24-h P-endorphin mean levels were significantly (p < 0.0001) higher in obese than controls (30.6 +/- 2 vs 22 +/- 1.9pg/ml), with acrophase located in the early morning hours in both groups. Finally, we found a positive relationship (R-2= 0.303; p = 0.0005) between leptin and P-endorphin circadian mean levels. These results show that the time course of 24-h rhythm of leptin and P-endorphin are similar in obese and lean women. The positive relationship between 24-h leptin and P-endorphin mean levels allow us to speculate that leptin may be a likely candidate to increase P-endorphin levels in obese subjects
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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