1,721,040 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
Single-center experience with the talent LPS endograft in patients with at least 5 years of follow-up
No full textPurpose: To evaluate long-term results in patients undergoing elective endovascular aneurysm repair (EVAR) using the Talent LPS endograft to treat abdominal aortic aneurysm (AAA).Methods: Fifty patients (49 men; median age 72 years, range 54–89) were treated electively between 1997 and 2001 with the Talent LPS endograft chosen for various anatomical reasons, including short (18 mm) in at least 1 iliac artery (32%), angulated (30°–60°) aortic neck (16%), large (>28 mm) aortic neck (6%), and tapered, reversed tapered, or bulging aortic neck (14%). A quarter of patients were preoperatively classified as unfit for AAA open repair, and 58% were high risk (ASA III or IV). The primary endpoints were immediate success, aneurysm-related and non-aneurysm related mortality, secondary interventions, graft-related complications, graft migration (>5 mm), and structural failure.Results: Implantation success was achieved in 96% (48/50). Four (8%) patients died within 30 days; in follow-up, the mortality rate was 51% over a mean 47.7 +/-27.4 months (minimum of 5 years). Aneurysm-related mortality was 12% (6/50); 3 (6%) tients were converted. The overall reintervention rate was 16% (8/50). There were 9 (18%) endoleaks in 8 patients: 4 type I (2 proximal, 2 distal), 3 type II, and 2 type III. The migration rate was 4% (1 ruptured AAA, 1 endoleak). Individual cases of graft kinking and stent fracture occurred in this series.Conclusion: Despite the small population, trends in our results suggest that the Talent stent-graft performs well over the long term. Surveillance, especially with regard to migration and graft integrity, remains of great importance
Treatment of a ruptured abdominal aortic aneurysm with an adverse anatomy using the Nellix endovascular aneurysm sealing system
No full textTransealing: A novel and simple technique for embolization of type 2 endoleaks through direct sac access from the distal stent-graft landing zone
No full textObjective: Type 2 endoleak (T2EL) is the Achilles' heel of endovascular abdominal aortic aneurysm repair. Experience with transealing, an alternative technique for the treatment of T2ELs, is described. Methods: The outcome of a group of patients treated with transealing has been reviewed. Femoral access was obtained with a 9-Fr sheath. A super-stiff guide wire and a stiff hydrophilic wire were placed inside the stent-graft and a Piton GC catheter inserted. The stiff hydrophilic wire was retrieved to allow the catheter to regain its curvature and the catheter tip was placed against the iliac wall, at the edge of the stent-graft. The hydrophilic wire was then forced between the stent-graft and arterial wall into the sac. A 5/6-Fr introducer was inserted inside the sac and angiography was performed to evaluate the leak. Coils, cyanoacrylate, or fibrin glue were deployed. After removal of the catheters, the iliac limb was ballooned. Results: Seventeen patients were treated between February 2009 and April 2013. It was possible to access the aneurysm in 16/17 attempts. One patient treated with acrylic glue suffered from colon ischemia. One intraoperative secondary type 1b endoleak was treated with an iliac extension. Mean follow-up was 21.5 months. Three months of follow-up were completed in 14 patients with a 53% freedom from endoleak rate. At 1 year, the rate was 45%. During the study period, there was one surgical conversion, one aneurysm growth, and one re-embolization procedure. The remaining leaks remained stable. Conclusions: This study shows that transealing is feasible and represents a valid alternative in selected patients. The advantages of this technique are mainly its low invasiveness, reduced costs, and ease of use. © 2014 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved
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
Trattamento degli aneurismi rotti dell'aorta addominale con endoprotesi Nellix:esperienza monocentrica
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