1,721,014 research outputs found

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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

    The application of ultrasound contrast agents in the characterization of renal tumors

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    The aim of this article is to describe the current ultrasound (US) contrast agents employed in the characterization of renal tumors and to report our experience in the use of a contrast-specific ultrasound technique pulse inversion harmonic imaging (PIHI). A total of 23 renal masses were prospectively evaluated by conventional US, CDUS, PIHI and finally by helical-CT (HCT). The study was performed using a wideband convex array 2-5 MHz transducer and a US digital apparatus. PIHI scanning of each renal mass was performed before and after the injection of Levovist. To reach a definitive diagnosis HCT and/or histological findings were considered as the reference procedures. Eleven solid renal cell carcinomas (RCCs), one embryonal metanephric adenoma (EMA), seven angiomyolipomas (AMLs), and four cystic RCCs were analyzed. Solid RCCs revealed a higher contrast enhancement than AMLs with a typical pattern on conventional US. The EMA and AML with an atypical pattern revealed intense contrast enhancement during the arterial phase, progressively decreasing during the delayed phase. Cystic RCCs showed intense contrast enhancement on the peripheral thick wall during the arterial phase decreasing during the delayed phase. PIHI with Levovist may differentiate solid RCCs from AMLs with no hypervascular pattern while solid RCCs show a higher intensity of contrast enhancement than hypervascular AML. © Springer-Verlag 2004.The aim of this article is to describe the current ultrasound (US) contrast agents employed in the characterization of renal tumors and to report our experience in the use of a contrast-specific ultrasound technique pulse inversion harmonic imaging (PIHI). A total of 23 renal masses were prospectively evaluated by conventional US, CDUS, PIHI and finally by helical-CT (HCT). The study was performed using a wideband convex array 2-5 MHz transducer and a US digital apparatus. PIHI scanning of each renal mass was performed before and after the injection of Levovist. To reach a definitive diagnosis HCT and/or histological findings were considered as the reference procedures. Eleven solid renal cell carcinomas (RCCs), one embryonal metanephric adenoma (EMA), seven angiomyolipomas (AMLs), and four cystic RCCs were analyzed. Solid RCCs revealed a higher contrast enhancement than AMLs with a typical pattern on conventional US. The EMA and AML with an atypical pattern revealed intense contrast enhancement during the arterial phase, progressively decreasing during the delayed phase. Cystic RCCs showed intense contrast enhancement on the peripheral thick wall during the arterial phase decreasing during the delayed phase. PIHI with Levovist may differentiate solid RCCs from AMLs with no hypervascular pattern while solid RCCs show a higher intensity of contrast enhancement than hypervascular AML. © Springer-Verlag 2004

    The role of granulocytes following intravesical BCG prophylaxis

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    Objectives: The antitumour effect of bacillus Calmette-Guérin (BCG) still remains relatively undefined. Most investigations on its mechanism of action have focused on mononuclear cells; little consideration has been given to granulocytes. We analysed urine of patients with bladder cancer during 8 wk of intravesical BCG prophylaxis. The number of polymorphonuclear neutrophils (PMNs) and urothelial cells (UCs) was evaluated. We examined the in vitro response of the T24 UC line to human PMNs after BCG treatment. Methods: Seventeen patients were enrolled in the study. Cytologic analyses were performed on urine samples collected before each BCG instillation and after 2 h from the first voided urine after BCG instillation. Elastase activity was determined on these samples to evaluate PMN activation. PMN-induced damage was measured on the T24 cell line treated with BCG. Results: After BCG treatment, a large number of PMNs transmigrated through the urothelium and PMNs adherent to detached UCs were found. One patient, who did not respond with significant PMN transmigration, experienced recurrent disease. The number of eosinophils that transmigrated was low, with the exception of three patients with recurrent disease. In vitro, PMNs adhered to BCG-primed T24 cells and damaged the monolayer. Conclusions: The results agree with recent evidence that PMNs may play an important role in the antitumour action of BCG during the BCG induction period. This role is probably nonspecific because both normal UCs in vivo and tumour cells in vitro appeared to be injured. As suggested by results obtained from a limited number of patients, a high number of eosinophils in the urine may indicate therapy failure. © 2006.Objectives: The antitumour effect of bacillus Calmette-Guérin (BCG) still remains relatively undefined. Most investigations on its mechanism of action have focused on mononuclear cells; little consideration has been given to granulocytes. We analysed urine of patients with bladder cancer during 8 wk of intravesical BCG prophylaxis. The number of polymorphonuclear neutrophils (PMNs) and urothelial cells (UCs) was evaluated. We examined the in vitro response of the T24 UC line to human PMNs after BCG treatment. Methods: Seventeen patients were enrolled in the study. Cytologic analyses were performed on urine samples collected before each BCG instillation and after 2 h from the first voided urine after BCG instillation. Elastase activity was determined on these samples to evaluate PMN activation. PMN-induced damage was measured on the T24 cell line treated with BCG. Results: After BCG treatment, a large number of PMNs transmigrated through the urothelium and PMNs adherent to detached UCs were found. One patient, who did not respond with significant PMN transmigration, experienced recurrent disease. The number of eosinophils that transmigrated was low, with the exception of three patients with recurrent disease. In vitro, PMNs adhered to BCG-primed T24 cells and damaged the monolayer. Conclusions: The results agree with recent evidence that PMNs may play an important role in the antitumour action of BCG during the BCG induction period. This role is probably nonspecific because both normal UCs in vivo and tumour cells in vitro appeared to be injured. As suggested by results obtained from a limited number of patients, a high number of eosinophils in the urine may indicate therapy failure. © 2006
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