1,721,014 research outputs found
The Ca-calmodulin dependent kinase II: A promising target for future antiarrhythmic therapies?
No full textAbstractTreating arrhythmias is a challenge for clinicians because pharmacological therapies are often ineffective or have severe side effects. Patients with heart failure frequently present with supreventricular and ventricular arrhythmias. New antiarrhythmic therapies are needed that modulate the specific pathomechanisms underlying the development of cardiac arrhythmias and may have a better safety-profile. The Ca-calmodulin dependent kinase II (CaMKII) seems to be involved in the development of heart failure and arrhythmias and may therefore be a promising target for the development of antiarrhythmic therapies. The current review aims at discussing some novel as well as known cytosolic and sarcolemmal mechanisms involved in CaMKII-dependent arrhythmias without being able to cover all aspects known in the field. This article is part of a Special Issue entitled "Calcium Signaling in Heart"
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
The ryanodine receptor leak: how a tattered receptor plunges the failing heart into crisis
Full text linkIt has been persuasively shown in the last two decades that the development of heart failure is closely linked to distinct alterations in Ca2+ cycling. A crucial point in this respect is an increased spontaneous release of Ca2+ out of the sarcoplasmic reticulum during diastole via ryanodine receptors type 2 (RyR2). The consequence is a compromised sarcoplasmic reticulum Ca2+ storage capacity, which impairs systolic contractility and possibly diastolic cardiac function due to Ca2+ overload. Additionally, leaky RyR2 are more and more regarded to potently induce proarrhythmic triggers. Elimination of spontaneously released Ca2+ via RyR2 in diastole can cause a transient sarcolemmal inward current and hence delayed after depolarisations as substrate for cardiac arrhythmias. In this article, the pathological role and consequences of the SR Ca2+-leak and its regulation are reviewed with a main focus on protein kinase A and Ca2+-calmodulin-dependent kinase II. We summarise clinical consequences of "leaky RyR2" as well as possible therapeutic strategies in order to correct RyR2 dysfunction and discuss the significance of the available data
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
The combined effects of ranolazine and low dose dronedarone on atrial vs. ventricular electrophysiology; a novel therapeutic hope?
No full textDispelling 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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