1,720,992 research outputs found
Structure-function relationships of pheromones of the ciliate Euplotes raikovi with mammalian growth factors: cross-reactivity between Er-1 and interleukin-2 systems.
Full text linkDiffusible protein signals of the ciliate Euplotes raikovi, denoted as pheromones, have functionally been linked with prototypic growth factors of animal cells by the demonstration that they not only induce a temporary cell union in mating pairs, by acting in a paracrine-like fashion, but can also bind to cells in autocrine fashion and promote their vegetative (mitotic) proliferation. It is now shown that pheromone Er-1 is capable of binding to the alpha and beta chains of the multimeric IL-2 receptor on mammalian cells and that IL-2 can, in turn, bind to the putative cell receptor of this pheromone. Similarities in the IL-2 and Er-1 structures support these findings and raise controversial implications with regard to their evolutionary significance
Valutazione in vivo ed in vitro della riparazione del danno al DNA indotta dal flavonoide antocianina sui Teleostei
No full textRAPD-PCR analysis for molecular characterization and genotoxic studies of a new marine fish cell line derived from Dicentrarchus labrax
No full textContinuous cell lines could provide an important tool for studying epidemiology, toxicology, cellular physiology and the host-pathogen interactions. Random amplified polymorphic deoxyribonucleic acid analysis by PCR (RAPD-PCR) was used for the molecular characterization of Dicentrarchus labrax embryonic cells (DLEC) as a possible tool to detect DNA alterations in environmental genotoxic studies. We studied the DNA pattern of the DLEC fish cell line, a fibroblast-like cell line derived from European sea bass. From a total of 15 primers only six showed good discriminatory power for the amplification process on DNA samples collected from cells by three different methods (organic extraction, salting-out method and chelating agent extraction). The results obtained show that the cell line chosen for this study could be used as a possible tool for the detection of potential genotoxicity of numerous chemical compounds. © 2013 Springer Science+Business Media Dordrecht
The effect of adrenalectomy on interleukin-1 release in vitro and in vivo.
No full text1 Peritoneal macrophages (M phi) collected from adrenalectomized (ADX) rats released more interleukin-1 (IL-1) activity and prostaglandin E2 (PGE2) than macrophages from sham-operated (SHO) rats. 2 The increase in IL-1 activity in the supernatants was confirmed by the increase of the cell-associated 33 kD IL-1 alpha precursor in ADX macrophages stimulated by lipopolysaccharide (LPS). 3 After the injection of Complete Freund's Adjuvant (CFA) to induce adjuvant arthritis, 60\% of the ADX rats died, while no deaths occurred in the SHO group. 4 The in vivo administration of dexamethasone inhibited both IL-1 and PGE2 release by macrophages as well as protecting ADX animals from CFA-induced death. Indomethacin and BW 755C partially protected the animals from this lethal effect. 5 These results suggest that adrenalectomy induces an increased release of IL-1 both in vitro and in vivo, and are consistent with a feedback mechanism between IL-1 and glucocorticoid hormones
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
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