1,720,981 research outputs found

    Study of pulmonary vascularization in pulmonary atresia with ventricular septal defect in relation to deletion of chromosome 22

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    A normal lung is supplied by a pulmonary artery branching from the pulmonary trunk. Major aorto-pulmonary collateral arteries (MAPCAs) are found in combination with various congenital heart malformations such as pulmonary atresia with ventricular septal defect (PA-VSD). Now that MAPCAs are used for unifocalization in patients with PA-VSD, the question arises as to whether the morphologic criteria of these collateral arteries could help to provide better results. We compared the morphology of the pulmonary vascular bed, the origin, course and connections of the MAPCAs in 40 consecutive infants with PA-VSD with or without 22q deletion (de122q11.2.). All underwent echocardiographic evaluation and catheterization. Identification of de122q11.2. was performed by FISH study. De122q11.2. was identified in 16 pts (40%); the presence of MAPCAs was significantly higher in patients with de122q11.2. (9/16 vs 3/24, p = 0.01). While complex morphology of MAPCAs, anastomoses with the central pulmonary artery outside the lung and absent ductus arteriosus were associated with de122q11.2, confluence of the pulmonary arteries was not a relevant phenotypic difference. The size of the right and left pulmonary arteries expressed as a standard deviation difference of the normal range for body surface area was -4.2 (quartiles - 3.1/-1.8) for PA-VSD with del22q11.2. and -2.6 (quartiles -5.3/-2.9) for PA- VSD without del22q11.2. (p = 0.02). The difference between measured and theoretical Nakata index was -373 ± 94 for PA-VSD with del22q11.2. vs. -245 ± 93 for PA-VSD without del22q11.2. (p = 0.0002). A specific pulmonary vascular bed phenotype could be defined in patients with PA-VSD with del22q11.2. deletion: MAPCAs with complex loop morphology and small but confluent central pulmonary arteries. These findings indicate a different timing of the faulty development pathway of the pulmonary vascular bed in patients with and without del22q11.2. This phenotype difference may help our understanding of maldevelopment and facilitate decisions concerning the suitability of these arteries for unifocalization procedures

    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

    Author Index

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    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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