1,720,963 research outputs found
Takayasu’s arteritis: a cell mediated large vessel vasculitis
No full textTakayasu's arteritis is an idiopathic, systemic inflammatory disease, typically involving the aorta and its main branches. Cell-mediated autoimmunity has been strongly implicated in its pathogenesis. Early or active-stage pathology consists of continuous or patchy granulomatous inflammation, which progresses to intimal and adventitial fibrosis and scarring of the media. Multiple focal or segmental stenoses result and aneurysms may occasionally occur. Clinical presentation is heterogeneous, ranging from asymptomatic to catastrophic. In some patients, constitutional signs and symptoms indicating a systemic inflammatory response are observed, usually in the early stages. Specific features reflect arterial involvement, and result from end-organ or limb ischemia; they include vascular, neurological, cardiac, and pulmonary manifestations. The course of Takayasu's arteritis usually extends for many years with varying degrees of activity. Takayasu's arteritis has a worldwide distribution, with the greatest prevalence in eastern countries. Women of reproductive age are preferentially affected, but the illness is being recognized with increasing frequency in males. Variable phenotypes are recently emerging in different ethnic groups. Diagnosis is based on clinical features and vascular imaging studies that document typical patterns of stenoses or aneurysms of the aorta and its primary branches. Assessment of the activity of Takayasu's arteritis is imprecise, in that clinical features and acute-phase reactants do not accurately reflect active blood vessel inflammation. High-dose corticosteroids alone or a cytotoxic agent in addition to a corticosteroid may be effective in treating active disease. Critical lesions may require correction by surgery or interventional radiology
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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