1,720,958 research outputs found
Criteria for interpretation of the athlete's ECG: A critical appraisal
No full textThe electrocardiogram (ECG) is cheap and widely available but its use as a screening tool for early identification of athletes with a cardiac disease at risk of sudden cardiac death is controversial because of its presumed low specificity. In the last decade, several efforts have been made to improve the distinction between physiological and pathological ECG findings in the athlete, leading to a continued evolution of the interpretation criteria. The most recent 2017 International recommendations grouped ECG changes into three categories: normal, borderline and abnormal. Borderline findings warrant further investigations only when two or more are present while abnormal changes should always be considered as the sign of a possible underlying disease. This review encompasses the evolution of the athlete's ECG interpretation criteria and highlights areas of uncertainty that will need to be addressed by further studies. This article is protected by copyright. All rights reserved
Arrhythmogenic Cardiomyopathy and Sports Activity
No full textArrhythmogenic right-ventricular cardiomyopathy (ARVC) is a genetically determined heart disease characterized by progressive myocyte death and substitution by fibrofatty tissue. Life-threatening ventricular arrhythmias may occur during the course of the disease and are distinctively triggered by sports activity: for this reason, ARVC is one of the leading causes of sudden death in the athlete. Early identification of affected athletes by preparticipation screening in the pre-symptomatic phase is essential, but differential diagnosis with the athlete's heart may be challenging. Variants with predominant involvement of the left ventricle are difficult to diagnose unless cardiac magnetic resonance is performed. Athletes with overt ARVC or asymptomatic carriers of pathological gene mutations, including those with an implantable cardioverter defibrillator, should refrain from competitive sports, while a moderate-intensity recreational physical activity appears safe
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
Differential diagnosis of arrhythmogenic cardiomyopathy: phenocopies versus disease variants
No full textArrhythmogenic cardiomyopathy (ACM) is a genetic heart muscle disease caused by mutations of desmosomal genes in about 50% of patients. Affected patients may have defective nondesmosomal genes. The ACM phenotype may occur in other genetic cardiomyopathies, cardiocutaneous syndromes or neuromuscular disorders. A sizeable proportion of patients have nongenetic diseases with clinical features resembling ACM (phenocopies). The identification of biventricular and left-dominant phenotypic variants has made differential diagnosis more difficult because of the broader spectrum of phenocopies which require a detailed clinical study with appropriate evaluation of most prominent and discriminatory disease features. Conditions that enter into differential diagnosis of ACM include heart muscle diseases affecting the right ventricle, the left ventricle, or both. To confirm a conclusive diagnosis of ACM, these differential possibilities need to be reasonably excluded by an accurate and targeted clinical evaluation. This article reviews the clinical and imaging features of major phenocopies of ACM and provides indications for differential diagnosis. The recent etiologic classification of Arrhythmogenic Cardiomyopathies, whose common denominator is the distinctive phenotype characterized by a hypokinetic and nondilated ventricle with a large amount of myocardial fibrosis underlying its propensity to generate ventricular arrhythmias is also addressed
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
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