1,721,030 research outputs found
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
Étude des protéines « Plant Mobile Domain », à l'interface entre espèce modèle et plante à intérêt agronomique afin de comprendre leur rôle au cours du processus de maturation du fruit de la tomate
No full textDans le noyau des cellules eucaryotes, l’ADN forme un complexe avec les protéines histones appelé la chromatine. Les modifications de la chromatine, dites épigénétiques, influencent la transcription des gènes. Ces modifications ont aussi un rôle dans la répression des éléments transposables (ETs). Chez Arabidopsis thaliana, les protéines MAINTENANCE OF MERISTEM (MAIN), MAIN-LIKE 1 (MAIL1) et MAIL2 appartiennent à la famille des Plant Mobile Domain (PMD). Les protéines MAIN et MAIL1 interagissent ensemble ainsi qu’avec PROTEIN PHOSPHATASE 7-LIKE (PP7L) afin de réguler la transcription des gènes et réprimer les ETs. Le rôle de MAIL2 dans la cellule reste inconnu. Un homologue de MAIL2, SlPMD2, existe chez Solanum lycopersicum (tomate). Le but de ma thèse a été de décrire plus en détail le mode d’action de MAIN et MAIL1, de comprendre le rôle de MAIL2 dans la cellule et d’explorer le rôle de SlPMD2 chez la tomate. J’ai pu démontrer que MAIN et MAIL1 sont impliquées dans la répression de plusieurs ETs de manière indirecte via le contrôle de la transcription de ICRORCHIDIA 1 (MORC1) qui est un important facteur épigénétique. J’ai pu démontrer par des approches de biochimie que MAIN et MAIL1 interagissent avec la chromatine principalement dans le promoteur de gènes et que ces protéines empêchent la déposition sur certains de ces gènes de la marque épigénétique répressive H3K27me3 par la voie Polycomb. De plus, j'ai montré qu'un motif spécifique d'ADN, que j'ai appelé motif MAIL1-MAIN (M1M), est enrichi dans les régions génomiques liées par MAIN et MAIL1 et pourrait peut-être recruter ces protéines. Par des analyses phénotypiques et transcriptomiques j’ai montré que MAIL2 est requis pour le développement de la graine et pour la bonne transcription de certains gènes. J'ai identifié dans le promoteur de certains de ces gènes dérégulés un motif d'ADN que j'ai appelé le motif MAIL2 (M2M). J’ai pu montrer que dans la tomate SlPMD2 est également requis pour le bon développement de la graine et qu’il contrôle l’expression de plusieurs gènes dans la fleur Enfin, je présente des données préliminaires suggérant que SlPMD2, qui est l'homologue de MAIL2 chez la tomate, est impliqué dans le développement et la germination des graines, très probablement en contrôlant l'expression de gènes spécifiques. Comme chez A. thaliana, j'ai identifié un motif ADN, très similaire au motif M2M, dans le promoteur de plusieurs gènes qui sont misrégulés chez le mutant slpmd2. Dans l'ensemble, mes résultats suggèrent que les protéines PMD pourraient être recrutées dans des régions génomiques spécifiques par le biais d'un motif d’ADN conservé au cours de l'évolution afin d'assurer la correcte expression des gènes, potentiellement en antagonisant la voie Polycomb chez les Angiospermes.In the nucleus of eukaryotic cells, DNA interacts with histone proteins to form a complex called chromatin. Epigenetic modifications of chromatin influence gene transcription. These modifications also play a role in silencing of transposable elements (TEs). In Arabidopsis thaliana, the MAINTENANCE OF MERISTEM (MAIN), MAIN-LIKE 1 (MAIL1) and MAIL2 proteins belong to the Plant Mobile Domain (PMD) family. MAIN and MAIL1 interact with each other and with PROTEIN PHOSPHATASE 7-LIKE (PP7L) to regulate gene transcription and repress TEs. The role of MAIL2 into the cell remains nknown. A homolog of MAIL2, SlPMD2, exists in Solanum lycopersicum (tomato). The aim of my thesis was to describe in more details the mode of action of MAIN and MAIL1, to understand the role of MAIL2 within the cell and to explore the role of SlPMD2 in tomato. I was able to demonstrate that MAIN and MAIL1 are indirectly involved in the silencing of several TEs, by controlling MICRORCHIDIA 1 (MORC1) transcription, which is an important epigenetic factor. Using biochemical approaches, I showed that MAIN and MAIL1 interact with chromatin mainly in gene promoters, and that these proteins prevent the deposition of H3K27me3 mediated by the Polycomb pathway. In addition, I found that a specific DNA motif, called the MAIL1-MAIN (M1M) motif, is enriched at genomic regions targeted by the PMD proteins. Besides, phenotypic and transcriptomic analyses showed that MAIL2 is required for seed development and for the correct expression of several genes, a fraction of them carrying another specific DNA motif called MAIL2 motif (M2M) in their promoter. Finally, I present preliminary data suggesting that SlPMD2, which is the MAIL2 counterpart in tomato, is involved in seed development and germination, most likely by controlling the expression of specific genes. Like in A. thaliana, I identified a DNA motif, which is highly similar to the M2M motif, in the promoter of several genes that are misregulated in the slpmd2 mutant. Altogether, my results suggest that PMD proteins might be recruited at specific genomic regions through an evolutionary conserved DNA motif to ensure the proper expression of genes, possibly by antagonizing the Polycomb pathway in Angiosperms
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
Molecular and physiological characterization of tomato (Solanum lycopersicon) ethylene response factor (ERF)
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