1,721,485 research outputs found
The role of adenosine A2A receptor signalling in cardiac fibrosis
Full text linkMyocardial fibrosis contributes to the pathogenesis of diverse forms of cardiac hypertrophy. Recent evidence suggests a crucial role for purinergic signalling in the formation of tissue fibrosis. In particular, inhibition of adenosine A2A receptors (A2AR) in animal models for hepatic and skin fibrosis resulted in a reduction of fibrosis formation. The specific hypothesis of this investigation was that myocardial stress results in increased interstitial levels of adenosine, which activate cardiac fibroblasts via adenosine A2AR. Accordingly, the specific objective of this investigation was to delineate the role of adenosine A2AR signalling in the development of myocardial fibrosis. In vitro, isolated cardiac fibroblasts demonstrated a significant increase in collagen secretion into CCM upon specific A2AR stimulation. This stimulatory effect was inhibited by the addition of a specific A2AR inhibitor. In vivo, models for cardiac hypertrophy including the transgenic cardiac actin E99K hypertrophic cardiomyopathy model, and a transverse aortic constriction (TAC) model of pressure overload, were investigated as murine models for myocardial fibrosis (MF). In cardiac actin E99K hearts the occurrence of cardiac fibrosis was associated with ventricular dysfunction, as well as energetic perturbations. In addition, a direct linear correlation between myocardial collagen content and interstitial adenosine levels was found in actin E99K hearts upon microdialysis experiments. Crossbreeding of actin E99K and A2AR knock-out (KO) mice resulted in a significant reduction of myocardial collagen content and fibrosis in E99K heterozygous A2AR KO animals compared to E99K heterozygous A2AR wild-type (WT) animals. Further, adenosine A2AR KO mice undergoing transverse aortic constriction demonstrated significantly less fibrosis formation compared to constricted WT mice. This was associated with a significant rescue of cardiac function. In addition, pharmacologic adenosine A2AR inhibition using the antagonist ZM241385 demonstrated a partial rescue of myocardial fibrosis in both TAC and E99K animals. These data suggest that adenosine the A2AR plays a crucial role in the formation of myocardial fibrosis in a variety of cardiac pathologies and that this pathway is susceptible to pharmacologic modulation. A2AR manipulation may contribute to further understanding of pathophysiological pathways in the development and progression of cardiac disease and represents an excellent therapeutic target for clinically available A2AR antagonists
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe 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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
