1,721,144 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
Pulmonary arterial hypertension and heart failure with preserved ejection fraction: Are they so discordant?
Full text linkHeart failure with preserved ejection fraction (HFpEF) and pulmonary arterial hypertension (PAH) are two emerging diseases focusing the attention of numerous researchers. In the last PAH guideline, there is a crossroad between the two diseases and pulmonary hypertension (PH) due to heart failure (HF) is categorized as subtype 2. In order to assess the correct diagnosis and management, it should be better understood the points of convergence and divergence of two diseases. Although, risk factors, demographic characteristics and haemodynamics are different, we report several similarities regarding vascular alterations, some aspects of cardiac remodelling, and clinical presentation. This model suggests HFpEF and PAH as two comparable conditions, with different cardiac adaptation and trajectories, linked to the intrinsic properties of either right and left ventricles. In both diseases the early pathophysiological mechanisms appear to begin from peripheral vasculature and to be backward transmitted to the larger arterial vascular district, and eventually to the myocardial structure. In this paper we would propose a simple approach to recognize the concordances and, all at once, distinguish the peculiarities of the two diseases
Update on tricuspid regurgitation
No full textAlthough commonly detected by transthoracic echocardiography, tricuspid regurgitation (TR) has been somehow neglected, and recent data have emerged on the need for careful examination of the tricuspid valve. Functional or secondary TR is the most frequent etiology of tricuspid valve pathology in western countries and is related to tricuspid annular dilation and leaflet tethering. The prognostic role of TR associated with organic left-sided valvular heart disease is well known. However, the value of functional TR in outcome stratification of patients with advanced left ventricular dysfunction is less clear. Surgical tricuspid repair has been avoided for years, because of the misconception that TR should disappear once the primary left-sided problem is treated; this results in a large number of untreated patients with functional TR. Over the past few years, many investigators have reported evidence in favor of a more aggressive surgical approach to functional TR. Consequently, interest has been growing in the pathophysiology and treatment of functional TR. The purpose of this article is to provide a comprehensive review of TR incorporating a description of valve anatomy, etiological factors, pathophysiology, epidemiological data, natural history, clinical evaluation, along with a discussion of the important role in prognostic stratification and a summary of management guideline
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
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