1,721,185 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
Continuous Positive Airway Pressure During Upper Endoscopies: A Bench Study on a Novel Device
Meta-analysis of Randomized Trials of Effect of Milrinone on Mortality in Cardiac Surgery: An Update
Objective: The long-term use of milrinone is associated with increased mortality in chronic heart failure. A recent meta-analysis suggested that it might increase mortality in patients undergoing cardiac surgery. The authors conducted an updated meta-analysis of randomized trials in patients undergoing cardiac surgery to determine if milrinone impacted survival. Design: A meta-analysis. Setting: Hospitals. Participants: One thousand thirty-seven patients from 20 randomized trials. Interventions: None. Measurements and Main Results: Biomed, Central, PubMed, EMBASE, the Cochrane central register of clinical trials, and conference proceedings were searched for randomized trials that compared milrinone versus placebo or any other control in adult and pediatric patients undergoing cardiac surgery. Authors of trials that did not include mortality data were contacted. Only trials for which mortality data were available were included. Overall analysis showed no difference in mortality between patients receiving milrinone versus control (12/554 [2.2%] in the milrinone group v 10/483 [2.1%] in the control arm; relative risk [RR] = 1.15; 95% confidence interval [Cl], 0.55-2.43; p = 0.7) or in analysis restricted to adults (11/364 [3%] in the milrinone group v 9/371 [2.4%] in the control arm; RR = 1.17; 95% Cl, 0.54-2.53; p = 0.7). Sensitivity analyses in trials with a low risk of bias showed a trend toward an increase in mortality with milrinone (8/153 [5.2%] in the milrinone arm v2/152 [1.3%] in the control arm; RR = 2.71; 95% Cl, 0.82-9; p for effect = 0.10). Conclusions: Despite theoretic concerns for increased mortality with intravenous milrinone in patients undergoing cardiac surgery, the authors were unable to confirm an adverse effect on survival. However, sensitivity analysis of high-quality trials showed a trend toward increased mortality with milrinone. (C) 2013 Elsevier Inc. All rights reserved
Variations on the Author
“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
We 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
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