1,720,985 research outputs found

    Differential splicing of three gonadotropin-releasing hormone transcripts in the ovary of seabream (Sparus aurata).

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    Previous studies demonstrated the presence of high-affinity GnRH binding sites and compounds with GnRH-like activity in the ovary of seabream, Sparus aurata, providing evidence for the role of GnRH as a paracrine/autocrine regulator of ovarian function in this species. In the present study, the expression of three forms of GnRH (salmon, chicken-II, and seabream) genes in this marine teleost species was demonstrated for the first time. Moreover, there is evidence for differential splicing and intronic expression of cGnRH-II and sbGnRH. Treatment of seabream follicle-enclosed oocytes with salmon GnRH stimulated reinitiation of oocyte meiosis, whereas chicken GnRH-II treatment was without effect. Novel information was also provided about organization of cGnRH-II and seabream GnRH transcripts, confirming that GnRH gene organization is maintained through evolution, despite changes in the size and sequence of exons and intron

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

    Proopiomelanocortin gene expression in the ovary of the frog, Rana esculenta.

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    The presence of proopionmelanocortin (POMC)-like mRNA has been demonstrated in a variety of extrapituitary tissues including hypothalamus,1 placenta,2 ovary,2 and testis.3 In amphibians, the POMC gene is actively expressed in the pituitary, both in melanotrope cells of the pars intermedia and in corticotrope cells of the pars distalis. 4–6 POMC gene expression in peripheral organs has also been investigated in Rana esculenta,7 indicating that POMC is actually synthetized in the ovary. Previous studies have shown that POMC-derived peptides are involved in local control of ovarian function and display seasonal changes.8,9 The aim of the present work was to develop a competitive reverse transcriptase polymerase chain reaction (RT-PCR) method using a synthetic, deletion mutant of POMC cRNA as an internal standard in order to quantify the amount of POMC mRNA in the ovary of Rana esculenta

    Appropriate Similarity Measures for Author Cocitation Analysis

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    We 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

    Genetically selected Marchigian Sardinian alcohol-preferring (msP) rats: an animal model to study the neurobiology of alcoholism

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    The present article provides an up-to-date review summarizing almost 18 years of research in genetically selected Marchigian Sardinian alcohol-preferring (msP) rats. The results of this work demonstrate that msP rats have natural preference for ethanol characterized by a spontaneous binge-type of drinking that leads to pharmacologically significant blood ethanol levels. This rat line is highly vulnerable to relapse and presentation of stimuli predictive of alcohol availability or foot-shock stress can reinstate extinguished drug-seeking up to 8 months from the last alcohol experience. The msP rat is highly sensitive to stress, shows an anxious phenotype and has depressive-like symptoms that recover following ethanol drinking. Interestingly, these animals have an up-regulated corticotrophin releasing factor (CRF) receptor 1 system. Clinical studies have shown that alcoholic patients often drink ethanol in the attempt to self-medicate from negative affective states and to search for anxiety relief. We propose that msP rats represent an animal model that largely mimics the human alcoholic population that due to poor ability to engage in stress-coping strategies drink ethanol as a tension relief strategy and for self-medication purposes
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