1,720,962 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
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
ST-Segment resolution after fibrinolysis or primary coronary angioplasty in the first three hours in acute myocardial infarction
No full textSuccessful treatment by percutaneous stent deployment of severe retrograde dissection of the right coronary artery extending into the sinus of Valsalva and ascending aorta.
No full textIntroduction. Dissection of the ostium of the right coronary artery (RCA) is a complication of PTCA which may become life-threating. Case report. A 45 year old man was admitted to our Coronary Care Unit (CCU) for acute anterior myocardial infarction. Coronary angiography revealed acute occlusion of left anterior descending coronary artery (LAD) and a chronic total occlusion of RCA. Primary PTCA of LAD was successfully performed. Nine days later he underwent PTCA of RCA; during the procedure the patient developed chest pain and ST-segment elevation in inferior leads. Angiography showed dissection of the RCA beginning at the ostium and progressing until the mid tract, which retrogradely extended into the sinus of Valsalva and ascending aorta. Two stents were placed at the entry door of the dissection, one at the ostium and one along the mid tract of RCA. Angiography showed successful sealing of the dissection. The ECG returned normal. Emergent transesophageal echocardiography and urgent CT scan confirmed the dissection resolved by stent apposition. Discussion. Management of the ostium dissection of the RCA involving the right sinus of valsalva depends on patients’ conditions, progression of aortic dissection and underlying coronary anatomy. In the case report here, dissection of RCA ivolving ascending aorta was successfully treated by stenting. Although surgical repair remains the best option, in the absence of complicating factors, percutaneous stent deployment may offer similar effective treatment
Does risk profile influence management of patients with NonST elevation coronary syndromes
No full textPercutaneous left ventricular assist device, TandemHeart, for high-risk percutaneous coronary revascularization. A single centre experience.
No full textPatients with severe depression of left ventricular ejection fraction and high-risk coronary lesions are at risk of developing complications during percutaneous coronary interventions (PCI). Intra-aortic balloon pump (IABP) is a support that helps the interventionalist in such hemodynamic complications during high-risk PCI, but it does not offer complete circulatory support. Instead, TandemHeart (Cardiac Assist, Pittsburg, PA, USA) is a percutaneous left ventricular assist device (pLVAD) that gives total left circulatory support and can be used for patients in cardiogenic shock or for elective PCI at high-risk. TandemHeart is a percutaneous transseptal ventricular assist device that allows a rapid percutaneous left ventricular support without the need for surgical implantation. Between November 2003 and April 2005, 6 patients admitted to our coronary care unit (CCU) underwent either emergency (n = 3) or elective (n = 3) placement of the TandemHeart device before a high-risk procedure. From our initial experience we conclude that the percutaneous transseptal ventricular assist device, TandemHeart, can be easily and rapidly deployed either in emergency or in elective high-risk PCI to achieve complete cardiac assistance
- …
