1,720,968 research outputs found
Treatment of end-stage cardiac failure: which surgical alternatives to heart transplantation?
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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
Left ventricular aneurysm resection with port-access surgery: a new mini-invasive surgical approach
No full textBACKGROUND: In recent years port-access and endovascular extra-corporeal circulation techniques have allowed valvular and coronary operations to be performed by mini-thoracotomy. Experience with the technique suggested application to resection of ventricular aneurysms, which are usually approached through a median sternotomy with the use of traditional cardiopulmonary bypass.
METHODS: We performed a left port-access mini-thoracotomy, with 6 to 8 cm skin incisions, in 7 patients undergoing endoventricular pericardial patch repair for anterior left ventricular aneurysm. Cardiopulmonary bypass was effected using the Heartport system. The mean interval between myocardial infarction and operation was 60.4 +/- 57.7 months. Three patients developed sustained ventricular tachicardia. Mean preoperative ejection fraction was 34% +/- 11%. Associated procedures were coronary bypass grafting in 2 patients and cryosurgery in 3 patients.
RESULTS: All patients survived to discharge and are alive and well after an average 14.5 months. They are all in NYHA class I-II. Postoperative echocardiograms revealed an average ejection fraction of 48.0% +/- 7.5% (p = 0.006 compared with preoperative value). The 3 patients who had cryosurgery did not demonstrate any recurrence of arrhythmias.
CONCLUSIONS: Left ventricular aneurysm can be successfully treated through port-access mini-thoracotomy with endovascular cardiopulmonary bypass, avoiding median sternotomy. This mini-invasive approach allows effective ventricular remodeling. Revascularization and antiarrhythmia surgery can also be done at the same time. In case of severely reduced ventricular function this approach permits fibrillatory arrest without aortic cross-clamping. The results are also good in terms of hospitalization time and long-term survival
Right ventricular failure after left ventricular assist device insertion: preoperative risk factors.
No full textRight ventricular failure after left ventricular assist device placement is the major concern on weaning from cardiopulmonary bypass and it is one of the most serious complications in the postoperative period. This complication has a poor prognosis and is generally unpredictable. The identification of pre-operative risk factor for this serious complication is incomplete yet. In order to determine pre-operative risk for severe right ventricular failure after left ventricular assist device support we analyzed preoperative hemodynamics, laboratory data and characteristics of 48 patients who received Novacor (World Heart Corp., Ottawa, ON, Canada). We compared the data from the patients who developed right ventricular failure and the patients who did not. Right ventricular failure occurred in 16\% of the patients. There was no significant difference between the groups in demographic characteristics. We identified as preoperative risk factors the pre-operative low mean pulmonary artery and the impairment of hepatic and renal function on laboratory data. Our results confirm in part the findings of the few previous studies. This information may be useful for the patient selection for isolated left ventricular assist device implantation, but other studies are necessary before establishing criteria for patient selection for univentricular support universally accepted
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
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