1,721,211 research outputs found
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
European A-SMGCS: the Challenge of Milan-Malpensa Airport in the Context of EMMA Project
No full textChronic thromboembolic pulmonary hypertension: an update
No full textChronic thromboembolic pulmonary hypertension (CTEPH) is a condition characterized by single or recurrent pulmonary thromboemboli that obstruct the pulmonary vascular bed, promoting increased pulmonary vascular resistance and progressive pulmonary hypertension and right-heart failure. Some studies have analyzed the risk factors associated with CTEPH, e.g. prior pulmonary embolism, younger age, large perfusion defect, idiopathic pulmonary embolism at presentation, risk factors for venous thromboembolism. The symptoms and signs of pulmonary hypertension are extremely variable. Patients may complain of progressive dyspnea on exertion, hemoptysis and/or signs of right heart dysfunction including fatigue, palpitations, syncope or edema after a single episode or recurrent episodes of overt pulmonary embolism. Echocardiography is widely used as the initial diagnostic tool when pulmonary hypertension is suspected. Imaging technologies including ventilation-perfusion scanning, computed tomography, MRI, and pulmonary angiography are a fundamental part of the diagnostic workup of patients with suspected CTEPH. From the point of view of current treatment of CTEPH pulmonary endarterectomy surgery remains the treatment of choice for symptomatic patients. The most common reasons for rejection of patients referred for pulmonary endarterectomy are severe comorbidity and significant distal disease in combination with excessive pulmonary hypertension. Such patients may benefit from pre-operative reduction of pulmonary vascular resistance by means of medical therapy. In fact over the last decade, several novel therapies have been developed for pulmonary arterial hypertension, including prostacyclin analogs (epoprostenol, beraprost, iloprost), endothelin receptor antagonists (bosentan, sitaxsentan, ambrisentan) and phosphodiesterase-5 inhibitors (sildenafil)
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