1,720,957 research outputs found
Study of the PGC-1α gene isoforms in muscle development in cattle
No full textLe coactivateur de facteurs de transcription PGC-1a (PPARC1A) est connu pour jouer un rôle clé dans la thermogénèse adaptative ainsi que dans l’homéostasie et la croissance musculaire chez l’homme et la souris. Le gène codant pour PGC-1 est contrôlé par deux promoteurs et est soumis à un épissage alternatif, il en résulte de multiples protéines. Chez le bovin, malgré son implication dans la croissance et dans les caractéristiques du lait relevée par des études de SNP, le gène et les transcrits de PGC-1a restent peu étudiés. Ainsi, notre objectif a été de mettre en évidence la structure et l’expression des transcrits de PGC-1a chez le bovin. Nous avons montré que deux formes longues PGC-1a-a et PGC-1a-b étaient exprimées chez le bovin de même que deux formes tronquées NT-PGC-1a-a et NT-PGC-1a-b (aussi appelé PGC-14). En conditions basales, les formes tronquées sont plus exprimées que les formes longues dans le muscle squelettique. De plus, les transcrits dérivants du promoteur proximal sont prédominants, ce qui suggère que NT-PGC-1a serait la forme prédominante dans le muscle squelettique bovin. Nous avons également créé des lignées cellulaires sur-exprimant indépendamment les formes longues ou tronquées et montré que la sur-expression des isoformes bovins entrainait une différenciation accrue des myoblastes associée à une augmentation de l’expression d’IGF-1 et une sousexpression de la myostatine. La multitude d’isoformes codée par le gène PGC-1a ainsi que leur implication dans la myogenèse positionne PGC-1a en gène d’intérêt dans l’étude de la variabilité phénotypique retrouvé chez certaines races bovines. De plus, les transcrits de PGC-1a semblent être de puissants modulateurs de la masse musculaire. PGC-1a pourrait donc être un gène de plus à étudier lors de la sélection des animaux domestiques présentant une plus grande musculature.The transcriptional co-activator PGC-1α (PPARGC1A) has been reported to play a key role in adaptive thermogenesis and to influence muscle homeostasis and growth in mouse and human. PGC-1α has a complex structure with multiple protein domains whose gene is controlled by two promoters and is subject to alternative splicing events. In cattle, very little is currently known about PGC-1α, despite its implication in growth and milk characteristics revealrd by SNP study. So, the aim of our study was to investigate the presence and the structure of bovine PGC-1α alternative transcripts. We found different transcripts, two full-length isoforms named PGC-1α-a and PGC-1α-b, and two truncated forms, NT-PGC-1α and PGC-1α4. In basal conditions, our results showed that the truncated forms are the most expressed in bovine muscle. In addition, the transcripts derived from the proximal promoter are predominant, suggesting that NT-PGC-1 would be the main form. Finally, we showed that the overexpression of either fulllength or truncated isoforms of bovine PGC-1 enhances myoblasts differentiation. The multiplicity of isoforms resulting from PGC-1α as well as their implication in myogenesismakes PGC-1α as a gene of interest for the study of the muscular phenotypic variability found in different cattle breeds. In addition, PGC-1 transctipts appear to be a strong modulators of muscle mass. So the bovine PGC-1a isoforms could be used to engineer future breeds with higher muscularity
Etude des isoformes du gène PGC-1a dans le développement musculaire chez le bovin
No full textThe transcriptional co-activator PGC-1α (PPARGC1A) has been reported to play a key role in adaptive thermogenesis and to influence muscle homeostasis and growth in mouse and human. PGC-1α has a complex structure with multiple protein domains whose gene is controlled by two promoters and is subject to alternative splicing events. In cattle, very little is currently known about PGC-1α, despite its implication in growth and milk characteristics revealrd by SNP study. So, the aim of our study was to investigate the presence and the structure of bovine PGC-1α alternative transcripts. We found different transcripts, two full-length isoforms named PGC-1α-a and PGC-1α-b, and two truncated forms, NT-PGC-1α and PGC-1α4. In basal conditions, our results showed that the truncated forms are the most expressed in bovine muscle. In addition, the transcripts derived from the proximal promoter are predominant, suggesting that NT-PGC-1 would be the main form. Finally, we showed that the overexpression of either fulllength or truncated isoforms of bovine PGC-1 enhances myoblasts differentiation. The multiplicity of isoforms resulting from PGC-1α as well as their implication in myogenesismakes PGC-1α as a gene of interest for the study of the muscular phenotypic variability found in different cattle breeds. In addition, PGC-1 transctipts appear to be a strong modulators of muscle mass. So the bovine PGC-1a isoforms could be used to engineer future breeds with higher muscularity.Le coactivateur de facteurs de transcription PGC-1a (PPARC1A) est connu pour jouer un rôle clé dans la thermogénèse adaptative ainsi que dans l’homéostasie et la croissance musculaire chez l’homme et la souris. Le gène codant pour PGC-1 est contrôlé par deux promoteurs et est soumis à un épissage alternatif, il en résulte de multiples protéines. Chez le bovin, malgré son implication dans la croissance et dans les caractéristiques du lait relevée par des études de SNP, le gène et les transcrits de PGC-1a restent peu étudiés. Ainsi, notre objectif a été de mettre en évidence la structure et l’expression des transcrits de PGC-1a chez le bovin. Nous avons montré que deux formes longues PGC-1a-a et PGC-1a-b étaient exprimées chez le bovin de même que deux formes tronquées NT-PGC-1a-a et NT-PGC-1a-b (aussi appelé PGC-14). En conditions basales, les formes tronquées sont plus exprimées que les formes longues dans le muscle squelettique. De plus, les transcrits dérivants du promoteur proximal sont prédominants, ce qui suggère que NT-PGC-1a serait la forme prédominante dans le muscle squelettique bovin. Nous avons également créé des lignées cellulaires sur-exprimant indépendamment les formes longues ou tronquées et montré que la sur-expression des isoformes bovins entrainait une différenciation accrue des myoblastes associée à une augmentation de l’expression d’IGF-1 et une sousexpression de la myostatine. La multitude d’isoformes codée par le gène PGC-1a ainsi que leur implication dans la myogenèse positionne PGC-1a en gène d’intérêt dans l’étude de la variabilité phénotypique retrouvé chez certaines races bovines. De plus, les transcrits de PGC-1a semblent être de puissants modulateurs de la masse musculaire. PGC-1a pourrait donc être un gène de plus à étudier lors de la sélection des animaux domestiques présentant une plus grande musculature
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
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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