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CT diagnosis of cerebral venous thrombosis: importance of the first examination fast treatment.
No full textThis study is a retrospective investigation of the role of non contrast-enhanced CT (NCCT) in the diagnosis of cerebral venous thrombosis (CVT) in clinical practice. We retrospectively identified 24 patients discharged with a diagnosis of CVT between January 2002 and December 2008 who had undergone NCCT as the first imaging modality. NCCT had been evaluated by a general radiologist and subsequently by a neuroradiologist in five cases. Final diagnosis was established by CT angiography (CTA), magnetic resonance (MR) and digital subtraction angiography (DSA). NCCT diagnosis was defined as "positive" when the neuroradiologist suggested the diagnosis of CVT on the report, as opposed to the "negative" diagnosis group. All NCCT examinations were reviewed by a neuroradiologist experienced in cerebrovascular pathology. We compared his evaluation and analysed the location and number of direct signs found on NCCT. The neuroradiologist strongly suggested an NCCT diagnosis of CVT in 63% (15/24) of patients: 80% (4/5) with deep venous thrombosis (DVT) and 57% (11/19) with sinus venous thrombosis (SVT). The general radiologist's NCCT evaluation was incorrect in four cases, subsequently diagnosed at NCCT by the neuroradiologist. After reviewing the NCCT examination the experienced neuroradiologist identified the CVT direct sign in two that belonged to the NCCT negative diagnosis group. Thus the direct sign was present in 71% (17/24) of the cases: all the patients with DVT and 63% (12/19) of the patients with SVT. NCCT still plays an important role for fast and accurate diagnosis of CVT in the emergency setting. NCCT displayed the CVT direct sign more frequently than previously thought and it was correctly interpreted in most cases. Neuroradiological consultation adds value to the general radiologist's evaluation
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
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
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