1,720,964 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
Composite valve graft implantation for the treatment of aortic valve and root disease: Results in 1045 patients
No full textObjectives Aortic root replacement using a composite graft is the treatment of choice for a large variety of aortic root conditions with a diseased aortic valve. The objective of the current study was to evaluate the long-term results of this procedure. Methods Between 1978 and 2010, 1045 patients aged 58.7 ± 13.6 years underwent aortic root composite graft replacement using the following techniques: 95 Bentall operation; 926 the “button technique;” 24 the Cabrol technique. A mechanical composite valve graft was implanted in 69.6% of the patients. Six-hundred and thirty-five patients (62.3%) had annuloaortic ectasia and 162 (15.5%) had aortic dissection. Results Early mortality was 5.3% (55/1045). Independent risk factors for early mortality at logistic regression analysis were age ≥70 years (P = .051; odds ratio [OR], 2.97), New York Heart Association III-IV (P = .052; OR, 1.88), reoperation (P = .021; OR, 2.36), urgency/emergency (P = .003; OR, 3.09), mitral valve replacement (P = .001; OR, 6.01), or coronary artery bypass grafting (CABG) (P < .001; OR, 4.39); while bicuspid aortic valve (BAV) (P = .013; OR, 0.21), and time of operation 2001-2011 (P = .025; OR, 0.60) were protective predictors for early mortality. Overall survival at 5, 10, and 20 years was 84.1% ± 1.3%, 65.5% ± 2.6%, and 40.7% ± 4.6%, respectively. Multivariate analysis revealed chronic renal insufficiency (P = .001; hazard ratio [HR], 3.48), chronic obstructive pulmonary disease (P = .027; HR, 1.94), aortic dissection (P = .001; HR, 2.63), Cabrol technique (P = .009; HR, 15.34), and CABG (P = .016; HR, 2.02) to be significant predictors of late death, and BAV (P = .010; HR, 0.43) to be a significant protective predictor. Freedom from thromboembolism, bleeding complications, and endocarditis was 93.7% ± 2.6%, 90.3% ± 3.1%, and 98.4% ± 1% at 20 years, respectively. Freedom from aortic reoperation was 91.8% ± 2.1% at 20 years and was significantly lower in patients with aortic dissection. Conclusions Within the limitations of this retrospective study, we can conclude that aortic root replacement for aortic root aneurysms can be performed with low morbidity and mortality and with satisfactory long-term results. Few late serious complications were related to the need for long-term anticoagulation or a prosthetic valve. Reoperation on the proximal or in the distal aorta was most commonly performed in patients with aortic dissection
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
Visceral organ protection in aortic arch surgery: Safety of moderate hypothermia
No full textObjectives: Although antegrade selective cerebral perfusion (ASCP) provides good brain protection during aortic arch surgery, the issue of distal organ protection during circulatory arrest remains to be clarified. The aim of the study was to retrospectively evaluate the outcome of aortic arch surgery using ASCP at different temperatures, focusing on visceral functions (VFs). Methods: Three hundred and thirty-four patients underwent elective aortic arch surgery using ASCP from November 1996 to March 2011. Those patients without early postoperative low cardiac output syndrome were included. VFs were evaluated by comparing preoperative and postoperative creatinine, aspartate amino transferase, alanine amino transferase and bilirubin. Univariate and multivariate analysis were performed. Results: Three hundred and four patients represent the cohort of the study. Deeper systemic hypothermia (â¤25°C) (Group A) was used in 194 patients (63.8%) and moderate hypothermia (>25°C) (Group B) in 110 patients (36.2%). The 30-day mortality rate was 3.6% in Group B and 5.2% in Group A (P = NS). Permanent neurological deficits occurred in 4 (3.6%) and in 14 patients (7.2%) of Group A and Group B, respectively (P = NS). Postoperative renal insufficiency requiring dialysis occurred in 6 patients (5.4%) in Group A and in 15 patients (7.7%) in Group B, the differences were not statistically significant. Biochemical markers of VFs increased in the postoperative period without differences between groups. At the multivariate analysis, cardiopulmonary bypass time >180 min (odds ratio (OR) = 2.16) was the only significant risk factor for renal dysfunction with or without liver dysfunction, while cardiopulmonary bypass time longer than 180min (OR = 2.28) and hypothermia higher than 25°C (OR = 0.54) were found to be independently related to liver dysfunction. Conclusions: Our results confirmed that ASCP with moderate hypothermia at 26°C is a safe method for brain protection. Moreover, during circulatory arrest, moderate hypothermia also offers good protection of visceral organs and it should be preferred for limited periods (<60 min) of visceral ischaemia because it may reduce the systemic inflammatory response and the reperfusion organ injury. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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