1,720,996 research outputs found

    Thrombolysis in dementia patients with acute stroke : is it justified?

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    The administration of thrombolytic therapy in elderly patients with dementia and acute ischemic stroke may be controversial, because the reported risk of rt-PA associated intracerebral hemorrhage in these patients is higher compared with that of patients without dementia and because these patients are already disabled. Moreover, there are known risk factors for hemorrhagic transformation in patients with dementia: amyloid angiopathy, leukoaraiosis and the presence of microbleeds. In this review, we describe the impact of dementia on functional outcome following thrombolytic therapy for acute ischemic stroke and discuss some of the issues related to the use of this therapy in this specific patient's population

    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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    History of cardiac embolism

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    From 1742, the first time Gerhard van Swieten postulated that embolism might arise inside the heart chambers and great vessels, another century was needed before that clinicians became accustomed to the concept that an embolism can lead to an occlusion of a brain artery. In fact, in 1875, Gowers described a case of blindness and contralateral hemiplegia in a patient with mitral stenosis. At autopsy, emboli were found in the middle cerebral artery and in the central retinal artery. Specifically, the emboli were found to originate from clots on the auricular appendices. Subsequently, in 1954, Fisher demonstrated that a thromboembolic mechanism underlies most ischemic strokes and that the source of thrombus might be the heart rather than a proximal arterial lesion. He suggested that the embolus might have arisen after myocardial infarction, in the fibrillating atrial appendage. In 1977, a necropsy study provided additional evidence supporting the role of atrial fibrillation as a crucial cause of cerebral embolism which was later confirmed by large epidemiological studies. Finally, in the first part of the 1990’s, several studies reported that oral anticoagulants consistently reduced the risk of stroke in patients with atrial fibrillation. Oral anticoagulants currently remain the most powerful stroke prevention strategy available for patients with atrial fibrillation

    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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