1,720,958 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
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
Endothelin-1 LYS198ASN and ETA receptor H323H polymorphisms and risk for coronary artery disease
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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
Endothelial function and carotid intima-media thickness in young healthy subjects among endothelial nitric oxide synthase Glu298-->Asp and T-786-->C polymorphisms
No full textDownregulation of von Willebrand Factor prevents Ang II-induced endothelin-1 expression independently of eNOS activation in porcine endothelial cells
No full textPurpose: Angiotensin II (AngII) generated under conditions of myocardial ischemia and reperfusion increases endothelial levels of endothelin (ET)-1, von Willebrand factor (vWF) and anion superoxide (O2-), which lead to progressive coronary endothelial dysfunction. Recent study described that vWF blockade improves endothelial function in coronary patients, but the mechanisms are still unknown.
Our study investigated whether the downregulation of vWF modulates the ET-1 level, eNOS activity and O2- generation in porcine aortic endothelial cells (PAOECs) chronically exposed to AngII.
Methods: The silencing of vWF in PAOECs was induced with selective short interference RNA. Protein expression of endothelial vWF, ET-1, eNOS and phospho-Ser1177eNOS (p-eNOS) was measured by western blotting in wild type and vWFknockdown cells exposed to vehicle or AngII (100nM for 24h). O2- formation was measured by dihydroethidium staining. In additional experiments, wild type and
vWF-knockdown cells were treated with phorbol 12-myristate 13-acetate (PMA, 5nM for 48h), a nonsubtype selective agonist of protein kinase type C and inhibitor of eNOS activity.
Results: Nearly 65% silencing of vWF cell viability and growth were not impaired. Levels of ET-1, phospho-Ser1177eNOS (peNOS)/eNOS ratio and O2- were unchanged in vWF-knockdown compared to wild type cells under normal conditions.
Conversely, ET-1expression was reduced by 93.7±4% (P<0.0001) in the presence of normal p-eNOS/eNOS ratio in vWF-knockdown cells under oxidative microenvironment; although, the intracellular load of O2- was reduced by 33.3±2% in vWF-knockdown cells with lower level of Mn superoxide dismutase. In additional experiments, the inhibition of eNOS activity by PMA did not reverse the downregulation of ET-1.
Conclusions: We demonstrated that vWF-knockdown modulates the response of PAOECs to chronic exposure to AngII by preventing cell death, reducing ET-1 and O2- production without affecting endothelial function. Our findings support the usefulness of vWF as upstream modulator of ET-1 expression under oxidative stress
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