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    Agenesia della colecisti senza atresia delle vie biliari

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    Authors describe a case of gallbladder agenesis observed at the Dept. Of Surgery of the University of Perugia. Gallbladder agenesis is a rare malformation whose 300 cases are described; the majority of them are observed during a necroscopy, many others are incidentally found during a surgical procedure carried out for several different indications. The disease incidence is between 0.01 and 0.04 for 100.000 in standard population. Almost half of the subjects are even affected by cardio vascular, scheletal, urinary tract or gastroenteric malformation

    The unwanted third wheel in the Calot's triangle: Incidence and surgical significance of caterpillar hump of right hepatic artery with a systematic review of the literature

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    BACKGROUND: Caterpillar hump of the right hepatic artery is a rare variation increasing the risk of vascular and biliary injuries during hepatobiliary surgery. The aim of this study is to record the cases of the right hepatic artery forming caterpillar hump in a cohort of patients underwent laparoscopic cholecystectomy and to report a review of the literature systematically conducted. METHODS: We reviewed clinical and surgical video data of 230 patients with symptomatic cholelithiasis treated with laparoscopic cholecystectomy between January 2016 and August 2017. A systematic literature search in PubMed, Medline, Cochrane and Ovid databases until 30th June 2017 was also performed in accordance with the PRISMA statement. RESULTS: Our institutional data indicated that 1.3% of 230 patients presented caterpillar hump right hepatic artery. The systematic review included 16 studies reporting data from a total of 498 human cadavers and 579 patients submitted to cholecystectomy. The overall proportion of surgical patients with the caterpillar hump right hepatic artery was 6.9%. CONCLUSIONS: Variations of the cystic artery are not just an anatomical dissertation, assuming a very crucial role in surgical strategies to avoid uncontrolled vascular lesions. A meticulous knowledge of the hepatobiliary triangle in association with all elements of 'Culture of Safety in Cholecystectomy' is mandatory for surgeons facing more than two structures within Calot's triangle

    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

    Dispelling the Myths Behind First-author Citation Counts

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    We 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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