1,721,466 research outputs found
Publisher Correction: Visualizing translation dynamics at atomic detail inside a bacterial cell
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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
Transcripts in Space and Time
No full textLes biologistes moléculaires cherchent à comprendre comment fonctionnent les organismes au niveau moléculaire. Le but ultime de ces recherches est d’offrir la possibilité de manipuler sans risque des cellules et/ou des organismes afin de combattre des maladies génétiques, d’éradiquer les maladies contagieuses ou par example d’améliorer les qualités nutritives de l’alimentation. Actuellement, la manière la plus précise et pratique de comprendre le fonctionnement d’un organisme est d’étudier son transcriptome et ses variations dans l’espace et le temps. Suivant cette logique, le but de ma thèse de doctorat a été double: (1) estimer l’importance de l’épissage alternatif qui engendre une diversité des transcripts (2) étudier les transcriptomes de deux organismes modèles : Mus musculus et Drosophila melanogaster, respectivement dans l’espace et le temps.
Durant ces années de recherche, j’ai rassemblé des découvertes intéressantes concernant l’expression des gènes et sa régulation. D’abord, l’épissage alternatif s’est avéré être un méchanisme important non seulement en terme de fréquence (des transcripts alternatifs sont générés pour une vaste majorité des gènes, et ce dans de multiples espèces), mais aussi en terme d’évolution (l’épissage alternatif semble permettre à un gène d’évoluer sans conséquences trop négatives pour l’organisme). Par ailleurs nous avons prouvé que le niveau d’expression de transcripts n’est pas en soi synonyme de fonction: il y a en effet une quantité non négligeable d’expression neutre, qui doit être prise en compte lors de l’assignation d’une fonction à un gène, uniquement basée sur la similarité de son profil d’expression par rapport à celui d’un gène de fonction connue. Enfin, nous avons étudié des séries de puces à ADN appliquées à l’embryogenèse de la mouche dans le temps, en utilisant une technique non conventionnelle pour ce type d’approche. Nous avons réparti les gènes en différentes classes selon leurs profils d’expression. Nous avons pu prouver que ces classes de gènes ont des critères biologiques en commun, ce qui laisse supposer que les gènes inconnus ou mal caractérisés qui tombent dans ces classes sont d’interessants points de départ pour de futures recherches.
Des découvertes inestimables ont été et seront encore faites en biologie moléculaire grâce à l’étude des transcriptomes dans des organismes variés, analysés dans différentes conditions. Cependant, il est devenu clair qu’à cause de la présence de nombreuses étapes de régulation après la transcription, dont l’épissage alternatif, seule l’analyse des protéomes permettra d’obtenir une vision complète de la biologie de la cellule.Molecular biologists aim at the understanding of organisms at the molecular level. The ultimate goal is to have the possibility to safely manipulate cells and/or organisms in order to heal genetic diseases, eradicate contagious diseases or for example improve nutrient qualities of food. Currently the most accurate and practical way to capture the functioning of an organism is to look at its transcriptome and its spatial and temporal variations. Following this logic, the focus of my PhD thesis has been two folds: (1) estimate the importance of alternative splicing in the generation of transcript diversity (2) study the transcriptomes of two model organisms: Mus musculus and Drosophila melanogaster, respectively in a spatial and in a temporal dimension.
Along these years of research I gathered interesting findings on gene expression and its regulation. First, alternative splicing proved to be an important mechanism both in terms of frequency (alternative transcripts are generated for a vast majority of genes and in many species) and evolution (it seems to allow a gene to evolve with manageable consequences for the organism). Moreover we were able to prove that levels of gene expression at the transcript level do not automatically imply function: there is a non negligible amount of neutral expression which has to be taken into account when inferring function according to similarities in expression patterns.
Lastly we investigated time series microarray data by applying an innovative technique which allowed grouping of genes into classes according to an original expression profiles criterion (”consistent changes”), and could show that this grouping makes biological sense, and hence that unknown or poorly characterized genes within these groups might be worth investigating further.
An inestimable insight on molecular biology has been and will be gained thanks to studies of the transcriptomes of different organisms in various conditions. However, the full picture seems to only be accessible with proteomics data due to the number of regulatory steps still present after the transcript level, among which alternative splicing
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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