1,721,009 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
Maternal endothelial function and vascular stiffness after HELLP syndrome: a case–control study
No full textObjectives: To assess endothelial function and arterial stiffness in women with a previous pregnancy complicated by pre-eclampsia (PE) with hemolysis, elevated liver enzymes and low platelet count (HELLP) syndrome, and to compare these findings to those in women with previous PE but no HELLP and to those in controls with previous uncomplicated pregnancy, in order to investigate the influence of HELLP syndrome on subsequent cardiovascular impairment. Methods: In this prospective single-center case–control study, we performed peripheral arterial tonometry (PAT) (using the EndoPAT method) and pulse-wave velocity (PWV) assessment in 109 women who had had a singleton pregnancy complicated by PE with (n = 49) or without (n = 60) HELLP syndrome, as well as in 60 controls with previous uncomplicated pregnancy, between 6 months and 4 years after delivery. The following EndoPAT and PWV indices were compared between groups: reactive hyperemia index (RHI), as an indication of endothelial function, and peripheral and aortic heart-rate-corrected augmentation indices (AIx) standardized for a heart rate of 75 bpm (AIx@75) and carotid–femoral pulse-wave velocity (cfPWV), as indications of arterial stiffness. Results: PAT and arterial stiffness indices were significantly different between PE cases, with or without previous HELLP, and controls, except for carotid–femoral PWV. There were no significant differences among PE groups: women who had experienced HELLP and those with a history of PE without HELLP showed similar rates of RHI ≤ 1.67 (28.6% vs 18.3%, P = 0.254) and RHI ≤ 2.00 (61.2% vs 41.7%, P = 0.055), peripheral AIx@75 ≥ 17% (38.8% vs 30.0%, P = 0.417), aortic AIx@75 ≥ 35% (29.2% vs 20.0%, P = 0.461) and cfPWV × 0.8 > 9.6 m/s, which occurred in only three women, all in the group without previous HELLP (0% vs 5.0%, P = 0.251). On multivariate regression analysis, HELLP syndrome, intrauterine growth restriction (IUGR) and early-onset PE independently predicted endothelial dysfunction at 6 months to 4 years postpartum, after correcting for uterine artery pulsatility index, birth-weight percentile, and maternal blood pressure, age and body mass index. Women with both previous HELLP and early-onset IUGR had a significantly higher prevalence of endothelial dysfunction (P = 0.001). Conclusion: Similar vascular abnormalities were found in women previously affected by HELLP syndrome and those with previous PE without HELLP. However, a history of HELLP syndrome, IUGR and early-onset PE seems to identify a subgroup of women with a higher risk for future development of endothelial dysfunction. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd
Evaluation of Ascending Aorta Wall in Rheumatoid Arthritis by Tissue and Strain Doppler Imaging During Anti-Tumor Necrosis Factor-α Therapy
No full text
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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