1,721,054 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
Quality of life 10 years after cardiac surgery in adults: a long-term follow-up study
No full textQuality of life (QoL) is a multifactorial concept that assesses physical and mental health. We prospectively studied the quality of life of patients undergoing coronary artery bypass graft (CABG) surgery using the Short-Form 36-item questionnaire (SF-36) up to 10 years after surgery. Between January 2000 and December 2002, all patients undergoing elective isolated CABG in the cardiac & thoracic surgery department of a large university hospital in Eastern France underwent initial QoL evaluation with the SF-36. The same questionnaire was mailed to every patient annually (± 2 weeks around the date of surgery) up to 10 years after their operation. We recorded socio-demographic and clinical variables at inclusion. Predictors of impaired QoL at 10 years were identified by logistic regression. A total of 272 patients (213 men, 59 women) were enrolled; mean age at inclusion was 65 ± 10 years. At 10 years post-surgery, 81 patients had died (29.7%). The physical component summary (PCS) score was significantly higher at 5 years after surgery than at baseline (p < 0.01), and significantly lower at 10 years than at 5 years (p < 0.01), although there remained a significant difference between 10-year PCS and baseline score (p = 0.004). The mental component summary (MCS) score was significantly higher at 5 years than at the time of surgery (p < 0.001), and remained significantly higher compared to baseline at 10 years after surgery (p = 0.010). By multivariate analysis, diabetes and dypsnea were both associated with worse PCS at 10 years, while lower age was associated with better 10-year PCS. Only diabetes was associated with impaired MCS at 10 years. Cardiac surgery appears to durably and positively affect both physical and mental components of quality of life
Perioperative patency of coronary artery bypass grafting is not influenced by off-pump technique
No full textBackground. Some concerns have been raised about technical accuracy and quality of distal anastomoses in off-pump myocardial revascularization. (OPCAB), which could affect graft patency.Methods. Transit-time flowmetric results and clinical, enzymatic, and echocardiographic findings from 201 consecutive isolated on-pump coronary artery bypass graft cases (cardiopulmonary bypass coronary artery bypass grafting; group A) were compared with 96 consecutive OPCAB (group B) cases performed at our institution between January 2003 and December 2004. Maximum, mean, minimum flow, and pulsatility index were compared, stratifying the two groups according to graft type and coronaries revascularized. Graft flow reserve was evaluated in patients undergoing preoperative intraaortic balloon pump during baseline conditions and at a 1 to 1 ratio of intraaortic balloon pump augmentation.Results. No differences were recorded between the two groups in hospital mortality, perioperative myocardial infarction, postoperative enzymatic leakage, echocardiographic recovery, or hospital stay (p = not significant). Off-pump coronary artery bypass and cardiopulmonary bypass coronary artery bypass grafting demonstrated similar intraoperative maximum (75.8 +/- 10.4 mL/min vs 82.3 +/- 15.8; p = 0.190), mean (50.1 +/- 13.3 vs 46.3 +/- 7.7; P = 0.420), minimum flow (12.7 +/- 5.3 vs 11.9 +/- 5.4; p = 0.811), and pulsatility index (2.9 +/- 0.2 vs 2.6 +/- 0.8; p = 0.360). After stratifying the population according to graft type, no differences were detected between the two groups in transit-time flowmetric results of left internal mammary artery, radial artery, and single and sequential saphenous vein grafts. A one to one ratio of intraaortic balloon pump augmentation did not result in any difference in graft flow reserve when left internal mammary artery (p = 0.699), radial artery (p = 0.066), and saphenous vein graft anastomoses (p = 0.772) were considered.Conclusions. Off-pump coronary artery bypass grafting and cardiopulmonary bypass coronary artery bypass grafting demonstrated similar clinical, biochemical, and transit-time flowmetric results, as well as comparable graft flow reserve. These data exclude a lower anastomotic quality in off-pump coronary artery bypass grafting
Changing performance of surgical risk scores according to the endpoint of postoperative mortality in infective endocarditis patients
Full text linkBackground: The optimal endpoint for reporting early mortality after cardiac operations for infective endocarditis (IE), as well as the optimal mortality target for surgical risk scores, are unresolved questions. Methods: Five risk scores created specifically to predict early mortality after cardiac operations for definite IE, and the European System for Cardiac Operative Risk Evaluation II, were assessed in terms of calibration, discrimination and accuracy in predicting early mortality following cardiac surgery for IE. The evaluation was based on five definite endpoints of postoperative mortality: In-hospital, 30-day, in-hospital/30-day, six-month, and one-year mortality. The six risk scores were tested in a population of 991 patients with definite IE who underwent 1,014 cardiac operations at five European university-affiliated centers. Results: There were 133 (13.1%) hospital deaths after surgery. Overall, 10% of patients died within 30 days after surgery, 10.4% of survivors died between 30 days and six months after surgery, and another 5.5% between six months and one year after surgery. All risk scores showed good prediction accuracy and at least acceptable discrimination for all endpoints of postoperative mortality. However, only one (IE-specific) risk score exhibited acceptable calibration for every endpoint of postoperative mortality. Conclusions: Since mortality decreases slowly throughout the first year after cardiac surgery for IE, it may be appropriate to report both in-hospital and one-year mortality (coupled endpoint) for this condition. For both endpoints, only one of the risk scores considered in this study showed acceptable calibration and discrimination
Validation of a Predictive Scoring System for Deep Sternal Wound Infection after Bilateral Internal Thoracic Artery Grafting in a Cohort of French Patients
No full textThe Gatti score is a weighted scoring system based on risk factors for deep sternal wound infection (DSWI) that was created in an Italian center to predict DSWI risk after bilateral internal thoracic artery (BITA) grafting. No external evaluation based on validation samples derived from other surgical centers has been performed. The aim of this study is to perform this validation
Effects of COVID-19 pandemic on cardiac surgery practice in 61 hospitals worldwide: results of a survey
No full textTo investigate the impact of COVID-19 infection on cardiac surgery community and practice
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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