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    The midsagittal view of the fetal brain: a useful landmark in recognizing the cause of fetal cerebral ventriculomegaly

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    To evaluate the positive predictive value of the midsagittal view of the fetal brain in recognizing the cause of ventriculomegaly diagnosed with traditional axial scan. METHODS: Fifty-eight pregnant women, referred to our Center following a generic diagnosis of ventriculomegaly have been evaluated: 38 had marked and 20 had borderline ventriculomegaly. The fetal brain was scanned by the midsagittal view using a transabdominal probe in fetuses in breech presentation or transverse lie and a transvaginal probe in fetuses in cephalic presentation. The possible cause of ventriculomegaly was postulated by combining the findings of the corpus callosum/cavum septi pellucidi complex with those of the posterior fossa. The prenatal diagnoses were compared with the anatomical specimens of aborted fetuses or with postnatal neuroimaging. RESULTS: The prenatal diagnoses were confirmed in 54/58 cases (PPV 93.1%). In the marked ventriculomegaly group, one case of partial agenesis of the corpus callosum was mistaken for a complete agenesis. In the group of borderline ventriculomegaly, two cases of partial agenesis of the corpus callosum were confused with a complete agenesis, while one case of suspected isolated ventriculomegaly was diagnosed after birth as partial agenesis of the corpus callosum. CONCLUSIONS: The sagittal scan of the fetal brain is a useful source of information and allows the contemporary view of both corpus callosum and posterior fossa, where various typical sonographic findings are present in ventriculomegaly

    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
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