1,720,955 research outputs found
Leptin levels and leptin and its receptor expression in pig placenta
No full textLeptin, an adipocyte hormone involved in energy homeostasis, is important in reproduction and pregnancy. The objective of this study was to investigate the relationship between placental leptin and its receptor gene expression and maternal plasma leptin concentration in swine, to try to understand the existence of an autocrine regulation for this hormone in placenta. This study began 15 days before the insemination of the animals and this is prolonged for the first month after the birth. The frequency of the drawings was every 15 days up to 45th day of gestation and every 7 days from 46th day up to the end of the protocol of work; an additional drawing has been executed, at parturition day. Leptin concentration was measured by the Linco Multi-Species Leptin Assay Kit; Tissue was taken at delivery, total RNA was extracted and RT-PCR was carried out with specific primers. Blood basal leptin was similar in all animals used: 1.560.03 ng/ml. Leptin levels increase during the pregnancy, but only during the last third of gestation we observed a significant rise in plasma levels (p<0.05). Maternal leptin levels are not modulated by the number of piglets and/or their weight. Results of RT-PCR studies show the expression of leptin and receptor long form: the receptor short form is not expressed. In effect the receptor long form was predicted to be the predominantly functional receptor. The presence of hormone and receptor in the same organ implies a possible autocrine/paracrine effect: these results indicate that leptin can be considered a gestational hormone implied in the endocrine function of the placenta, also with an important role in the autocrine control of the placenta function
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
Leptin levels and leptin and its receptor expresion in pig placenta.
No full textLeptin, an adipocyte hormone involved in energy homeostasis, plays a role in the control of reproduction and pregnancy. The objective of this study was to unravel a possible relationship between maternal plasma leptin concentrations and leptin receptor gene expression in swine. A total of 15 crossbred multiparous sows aging 24 - 36 months with an average weight of 160  10 kg were used. Blood samplings started 2 weeks before A.I. and were carried out every 15 dd until 45 dd of gestation; thereafter, blood samples were obtained weekly until 1 month post-partum. Leptin plasma levels were measured by the Linco Multi-Species Leptin Assay Kit; total RNA was extracted from placental tissue and RT-PCR was carried out with specific primers. Maternal leptin levels significantly (p<0.05) increased during the last third of gestation; they weren’t related with neither piglet number nor weight. Results of RT-PCR studies evidenced the expression of both leptin and receptor long (but not short) form; the long form had been predicted to be the predominantly functional receptor. The co-presence of hormone and receptor in the same organ implies a possible autocrine/paracrine effect. These results suggest that leptin may be involved in placental endocrine function
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
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