1,721,012 research outputs found

    Dynamics of propagation patterns and anti-arrhythmic mechanisms during atrial fibrillation

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    Atrial fibrillation leads to a rapid and irregular heartbeat. It is an extremely dynamic process involving many electrical waves. Wave patterns can be identified to help direct catheter treatments for atrial fibrillation. An accurate interpretation requires the use of many electrodes and a sufficiently long hospital admission. Vernakalant is the most recent medicine used to treat atrial fibrillation. While Vernakalant proved to be highly effective in treating this arrhythmia, we found the action mechanism to be different than previously thought. Vernakalant slows down electrical activation, which is associated with life-threatening arrhythmias. Careful patient selection is therefore imperative

    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

    Mechanisms of action of atrial-specific anti-arrhythmic drugs

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    Atrial fibrillation (AF) is a rhythm disorder characterized by fast and irregular activations of the atria. The patients with AF have an increased risk for having a stroke and for developing other cardiovascular diseases. Having effective strategies for treatment of AF is therefore essential. None of the currently available therapeutic strategies for treatment of AF achieves satisfying success rates. Moreover, the use of anti-arrhythmic drugs (AADs, drugs that can terminate the arrhythmia) is limited by their side effects, especially by an increased risk for development of ventricular arrhythmias. This creates an urgent need for development of new AADs that would be safe and efficient at the same time, as well as for better understanding of the mechanisms that are responsible for maintenance and termination of AF.The thesis describes antiarrhythmic mechanisms of two novel AADs in goats with AF. Both drugs are atrial-selective, which means that they affect atria but not ventricles. The results suggest that these drugs have a potential to become safe and efficient strategies for treatment of AF. The thesis also provides new insights into the mechanisms underlying AF termination. It demonstrates that regardless of the presence or the type of AAD, cardioversion of AF in goats is associated with increased organization of the fibrillatory process and with abrupt changes in electrophysiological parameters. Finally, the thesis presents a novel method for processing of experimental data that were acquired by a technique called optical mapping. Applying this method, the thesis provides new insights into the mechanisms underlying perpetuation of the arrhythmia

    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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    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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