1,720,959 research outputs found
Divergent pathways regulate ligand-independent activation of ER alpha in SK-N-BE neuroblastoma and COS-1 renal carcinoma cells
No full textThe α-estrogen receptor (ERα) transcriptional activity can be regulated either by binding to the cognate ligand or by intracellular signaling pathways responsive to a variety of factors acting through cell membrane receptors. Studies carried out in HeLa and COS-1 cells demonstrated that the cross-coupling between estrogen and growth factor receptors is mediated by p21ras and requires phosphorylation of a specific serine residue (Ser 118 in the human ERα and Ser 122 in mouse ERα) located in the ERα N-terminal activation function 1 (AF-1). Likewise, in the SK-N-BE neuroblastoma cell line p21ras is involved in the cross-coupling between insulin and ERα receptors. However, in this cell line Ser 122 is not necessary for insulin-dependent activation of unliganded ERα. In addition, after insulin activation, the electrophoretic mobility associated to serine hyperphosphorylation of ERα in SK-N-BE and in COS-1 cells is different. Our study rules out the possibility of tyrosine phosporylation in unliganded ERα activation by means of transactivation studies of ERα tyrosine mutants and analysis of Tyr phosphorylation immunoreactivity. The two cofactors for steroid receptors RIP 140 and SRC-1 do not seem to be specifically involved in the insulin-induced ERα transactivation. The present study demonstrates the possibility of an alternative, cell-specific pathway of cross-coupling between intracellular and membrane receptors, which might be of importance for the understanding of the physiological significance of this mode of activation in the nervous system
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Oligonucleotide squelching reveals the mechanism of estrogen receptor autologous down-regulation
Get PDFAntisense oligos complementary to the 5'-end, but not to the 3'-end, of the estrogen receptor (ER) messenger RNA caused a paradox accumulation of ER protein in MCF-7 cells, The same effect was observed after treatment of the cells with the corresponding sense oligos, The oligos interfering with ER down-regulation were demonstrated to specifically bind the ER with affinities in the nanomolar range. It is, therefore, proposed that the ER up-regulation induced by the oligos might be due to squelching of the ER (or ER-inducible proteins) from their binding site located in the 5'-end of the ER gene. We also report that transcriptionally inactive ER mutants can undergo down-regulation, and that in denaturing gels, the migration profile of ER-oligo and ER-estrogen-responsive element complexes are dissimilar. We, therefore, propose that ER can interact with DNA in different ways and at different binding sites, These observations might have important pharmacological consequences, since specific drugs could be devised to induce the ER conformation necessary to perform only selected tasks of the ER transcriptional repertoire
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