1,720,994 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
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
Oxidized-HDL3 modulates the expression of Cox-2 in human endothelial cells
No full textModified high density lipoprotein (HDL) has been suggested to modulate endothelial expression of proinflammatory genes. Since oxidised HDL (Ox-HDL) has been found in atheromatous plaques and receptors for modified HDL are present on endothelial cells, we investigated the effect of Ox-HDL3 on the expression of Cox-1 or Cox-2. Ox-HDL3, increased Cox-2 mRNA and protein expression in endothelial cells while no effect on Cox-1 expression was observed. The intracellular pathways involved in this effect were investigated. The incubation with specific inhibitors of intracellular kinases showed that PI3K is mainly involved in the Ox-HDL3-dependent Cox-2 induction. Transient transfection experiments suggested that the NF-IL6 response element in the proximal promoter (-327 to 59) is involved in Ox-HDL3-mediated Cox-2 expression. These data suggest that Ox-HDL induce Cox-2 expression in endothelial cells through a PI3K/NF-IL6-dependent pathwa
Anatomia e Fisiologia degli Animali Domestici
No full textUna nuova edizione aggiornata e rivista sulla base delle moltissime nuove acquisizioni scientifiche, uno strumento di studio e di lavoro rivolto a chi opera nei settori della Produzione Animale, delle Scienze Agrarie e delle Preparazioni Alimentari. Anatomia e Fisiologia sono discipline indispensabili per conoscere gli organismi viventi e costituiscono il binomio fondamentale sul quale costruire qualsiasi ulteriore conoscenza di ordine zootecnico – alimentari stico e patologico; questo lavoro sottolinea l’importanza della loro correlazione per fare sì che il fisiologo tenga in considerazione la struttura degli organismi e che il morfologo possa richiamarsi alle funzioni espletate dalle strutture che sta studiando. L’introduzione di un nuovo e aggiornatissimo glossario dei termini facilita la comprensione della materia
HDL3 induces cyclooxygenase-2 expression and prostacyclin release in human endothelial cells via a p38 MAPK/CRE-dependent pathway : effects on COX-2/PGI-synthase coupling
No full textOBJECTIVE: In endothelial cells, cyclooxygenase-1 (COX-1) and COX-2 both contribute to prostacyclin production. Recent findings suggest that COX-2 contributes significantly to systemic prostacyclin synthesis in humans; whether COX-2 inhibition is related to an increased cardiovascular risk is undergoing debate. HDLs have been shown to increase prostacyclin synthesis, thus in the present study we investigated the molecular mechanisms involved in this effect in endothelial cells. METHODS AND RESULTS: HDL3 (30 microg/mL) induced COX-2 expression in a time- and dose-dependent manner. COX-2 was found mainly in the perinuclear area where it co-localizes with PGI synthase. Transient transfection experiments showed that CRE is required for HDL-induced COX-2 transcription, and we demonstrated that p38 MAPK activation by HDL3 is involved in COX-2 mRNA transcription and stabilization. As a consequence of COX-2-induction by HDL3 prostacyclin production increased, incubation with a COX-2 selective inhibitor blocked this effect. Moreover, HDL3 increased caveolin-1 phosphorylation, thus promoting PGI-synthase shuttling from the membrane to the perinuclear area. CONCLUSIONS: We conclude that in endothelial cells, HDL modulates COX-2/PGI-S activity via both p38 MAPK-dependent COX-2 mRNA stability and transcription and both caveolin-1-dependent PGI-synthase shuttling and COX-2 coupling. The understanding of these mechanisms may provide new insights into the antiatherogenic role of HDL
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