1,720,994 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
Intra and inter-patient epigenetic heterogeneity in multiple myeloma
No full textL’évolution du cancer dépend d’une certaine hétérogénéité épigénétique et génétique. Dans le cas du myélome multiple (MM), la diversité sous-clonale et l’évolution tumorale ont été principalement étudiées sous un angle génétique. Dans notre étude, nous avons analysé l’hétérogénéité de la méthylation de l’ADN de patients atteints de MM, en utilisant la notion d’épipolymorphisme et la mesure des changements épialléliques entre deux états de la maladie. Nous avons montré que le MM est caractérisé par une augmentation stochastique / désordonnée de la méthylation de l’ADN au niveau des régions régulatrices. De forts changements épialléliques à l’initiation de la maladie sont associés à un mauvais pronostic et à la déméthylation de domaines partiellement méthylés (PMDs) sur le génome. Ces PMDs représentent la principale source d’hétérogénéité de la méthylation de l’ADN dans le cas du MM, et sont associés à d’autres aberrations clés dans le cancer telles que l’hyperméthylation des régions régulatrices et la redistribution de la marque d’histone H3K27me3. De plus, la perturbation de la méthylation dans ces régions régulatrices est également associée à une faible expression des gènes et à une grande variabilité transcriptomique. Nous proposons que la forte déméthylation de l’ADN observée dans le MM soit responsable de fortes instabilités épigénétiques et transcriptomiques permettant aux cellules tumorales de s’adapter aux changements environnementaux et d’adopter de nouvelles trajectoires.Cancer evolution depends on epigenetic and genetic diversities. Historically, in multiple myeloma (MM), subclonal diversity and tumor evolution have been mostly investigated through the genetic angle. In our study, we analyzed DNA methylation heterogeneity in MM patients, using the notion of epipolymorphism and epiallele switching between two disease states. We showed that MM is characterized by a continuous accumulation of stochastic methylation at promoters. High epiallele entropy is associated with poor outcome and predominantly depends on the demethylation of partially methylated domains (PMDs). These PMDs which represent the major source of DNA methylation heterogeneity in MM are linked to other key epigenetic aberrations such as CGI/TSS hypermethylation and H3K27me3 redistribution. In addition, methylation disorder is associated to low gene expression and high transcriptomic variability. We proposed that strong DNA methylation loss in MM is responsible for high epigenetic and transcriptomic instabilities allowing tumor cells to fit environmental changes by finding new trajectories
Molecular action of dexamethasone into Multiple Myeloma pathology
No full textLe Myélome Multiple est une hémopathie maligne caractérisée par une prolifération incontrôlée des plasmocytes dans la moelle osseuse. Lors du développement de cette pathologie, la cellule fait l’acquisition de nombreuses anomalies génétiques. Ces anomalies ne sont pas retrouvées chez tous les patients ni même dans toutes les cellules d’une même tumeur. Cette maladie est donc caractérisée par une grande hétérogénéité inter et intra-patient mais également intra-clonale. Parmi les divers traitements utilisés, la Dexaméthasone (Dex), une hormone glucocorticoïde est largement utilisée en combinaison avec d’autres médicaments. La Dex exerce son effet en se fixant à son récepteur (GR) pour agir comme un facteur de transcription en se fixant sur les séquences régulatrices du génome, principalement des enhancers, via des séquences de reconnaissance (GRE). Malgré un bénéfice certain de cette molécule en tant que traitement, tous les patients ne répondent pas de la même façon. De plus, si l’efficacité de la Dex est attribuée à une apoptose spécifique des lymphocytes B matures, les mécanismes moléculaires mis en jeu sont encore largement inconnus dans les plasmocytes. Pour mieux comprendre ce mode d’action, des analyses pangénomiques intégrant des données d’accessibilité à la chromatine, de fixation de facteur de transcription, de modification d’histones ainsi que des données de conformation de la chromatine couplées à des analyses en cellule unique ont été réalisées.Multiple Myeloma is a malignant hemopthy characterized by an aberrant proliferation of plasma cell in bone marrow. During development of this pathology, the cell acquires many genetic abnormalities. Not all the patients share those abnormalities and not even all the cells form one tumor. This pathology is characterized by a strong heterogeneity interand intra-patient but also intra-clonal. Among all treatments used, Dexamethasone (Dex), a synthetic glucocorticoid is widely used in combination with other drugs. Dex acts as a transcription factor by interacting with its recptor (GR) and binds to regulatory regions of genome, mostly enhancers, through reconizing DNA sequences (GRE). Despite a certain benefit of this molecule as treatment, all the patients not respond the same way. In addition, if B lymphocytes apoptosis is attributed to Dex efficiency, the molecular mecanisms involved are largely unknown in plasma cells. In order to better understand this mode of action, pan-genomics analysis integrating chromatin accessibility data, transcriptio factor binding, histones modifications and conformation data combined with single cell analysis have been performed
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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