1,720,956 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
Trattamento chirurgico di un voluminoso liposarcoma mixoide retroperitoneale plurirecidivo
No full textRetroperitoneal liposarcoma is a malignant neoplasm characterized by a high recurrence rate, varying from 35% to 82%, with a disease-free period of three years. Only in 25% of the cases it is possible to reveal distant metastasis. The elective treatment of the local recurrence is represented by the radical surgical ablation. Nowadays radiotherapy and/or chemiotherapy give poor results both in the treatment of the primary tumor and in the treatment of its recurrence. The Authors describe a case of retroperitoneal mixoid liposarcoma recurred many times
Our experience in the conservative surgical treatment of megaureter in the adult
No full textSurgical treatment of the megaureter in adults is only indicated when important symptoms and/or complications occur. The Authors report their experience with eight adult patients affected by megaureter, undergone to conservative surgery. The average age of the patients was 36 years (range 21-52). The disease was unilateral in five cases (four on the right side and one on the left), bilateral in three. In five patients megaureter was primary (obstructed in four, refluxing in one). A case of megaureter with ectopic orifice in the prostatic urethra was observed. The remaining two cases, already operated in other hospitals, were a segmentary megaureter associated with vesico-ureteral reflux secondary to endoscopic incision of an ureterocele and a bilateral refluxing megaureter in a patient undergone to bilateral ureterocystoneostomy because of primary megaureter in his childhood. All patients underwent ureterocystoneostomy, performed with Politano-Leadbetter antireflux technique in six cases and with direct non-antireflux technique in two. A reductive Hendren ureteroplasty was also performed in 7 cases. The average length of follow-up is actually of 82 months (range 5-231). Satisfactory results were obtained in three primary obstructed megaureters, in the megaureter with ectopic orifice and in the segmentary megaureter associated with reflux. In two patients with refluxing megaureter surgery was unsuccessful and a new operation was necessary. Finally, one patient with primary obstructed megaureter underwent endoscopic dilatation of the strictured vesico-ureteral anastomosis two months after the ureterocystoneostomy
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
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