1,720,956 research outputs found
Étude structurale et fonctionnelle de lecteurs de marques épigénétiques dans l'expression et le maintien du génome
No full textLa chromatine est une structure essentielle qui régit l'homéostasie cellulaire à travers diverses voies dépendantes de la molécule d'ADN telles que l'expression des gènes, la stabilité du génome, l'apoptose, etc. Ainsi, étudier ses mécanismes de régulation est un enjeu crucial pour comprendre le fonctionnement cellulaire. Un des facteurs clés de la modulation de la structure de la chromatine est le complexe acétyltransférase NuA4/TIP60. En effet, ce complexe multi-protéiques très conservé permet l'acétylation des histones, dont H4, et l'incorporation du variant H2A.Z. Il agit alors sur plusieurs mécanismes cellulaires tels que la réparation des cassures doubles brins d'ADN en favorisant la recombinaison homologue ou encore l'activation de la transcription. C'est pourquoi, il est primordial de comprendre en détails les fonctions de ce complexe. Mon projet de doctorat se découpe en deux parties selon les sous-unités du complexe NuA4/TIP60 étudiées. La première partie concerne la sous-unité MRG15, associée à de nombreux complexes, et donc impliquée dans plusieurs fonctions telles que la régulation de l'épissage ou encore la réparation de l'ADN. Combinant des méthodes d'édition du génome avec des purifications de complexes natif et de spectrométrie de masse, nous avons pu identifier un nouveau complexe, composé des sous-unités BRD8, MRGBP, MRG15/X ainsi qu'une nouvelle sous-unité, EP400NL, initialement décrite comme un pseudogène. Puis, par une technique de séquençage d'ARNs, nous montrons que ce complexe est important pour moduler l'expression de gènes spécifiques. De plus, nous avons étudié le mutant W78A/F105A de MRGBP qui perd l'interaction avec MRG15, et le mutant W172A/Y235A de MRG15 qui n'interagit plus avec les facteurs de réparations PALB2/BRCA2. De ce fait, ces mutants aideraient à la compréhension de la fonction de MRG15 lors de la réparation de l'ADN. La seconde partie de mon doctorat concerne la sous-unité MBTD1. En effet, nous nous sommes intéressés à la fusion entre MBTD1 et le facteur d'épissage ZMYND11. Elle est retrouvée dans des cas de leucémies myéloïdes aigües (LMA). Nous avons montré que les mécanismes oncogéniques de cette fusion sont dépendants de la délocalisation sur les corps des gènes du complexes NuA4/TIP60 induisant une augmentation d'acétylation de H4. Ceci génère alors un défaut transcriptionnel dont une surexpression de l'oncogène Myc et des dérégulations d'épissage alternatif de transcrits spécifiques. De plus, nous avons mis en évidence les résidus essentiels pour l'interaction entre MBTD1 et la sous-unité EPC1, associant alors MBTD1 avec le reste du complexe NuA4/TIP60. Ensemble, ces résultats permettraient le développement de nouveaux outils thérapeutiques pouvant cibler MBTD1 afin de traiter les cas de LMA spécifiques. L'ensemble de ces travaux offre une meilleure compréhension des fonctions du complexe NuA4/TIP60 liées à ses différentes sous-unités, à la fois au niveau transcriptionnel mais également au niveau de la réparation de l'ADN. De plus, ils établissent les mécanismes oncogéniques associées à ce complexe. Ainsi, de futures stratégies thérapeutiques pourraient être développées.Chromatin is an essential structure that governs cell homeostasis through various DNA molecule-dependent pathways such as gene expression, genome stability, apoptosis, etc. Thus, studying its regulatory mechanisms is a crucial issue in understanding cell functioning. One of the key factors in the modulation of chromatin structure is the acetyltransferase complex NuA4/TIP60. Indeed, this highly conserved multi-protein complex allows the acetylation of histones, including H4, and the incorporation of the H2A.Z variant. It then acts on several cellular mechanisms such as the repair of DNA double strand breaks by promoting homologous recombination or even the activation of transcription. This is why it is essential to understand in detail the functions of this complex. My doctoral project is divided into two parts according to the subunits of the NuA4/TIP60 complex studied. The first part concerns the MRG15 subunit, associated with many complexes and therefore involved in several functions such as the regulation of splicing or DNA repair. Combining genome editing methods with native complex purifications and mass spectrometry analysis, we were able to identify a new complex, composed of the BRD8, MRGBP, MRG15/X subunits as well as a new subunit, EP400NL, initially described as a pseudogene. Then, by an RNA sequencing technique, we show that this complex is important for modulating the expression of specific genes. In addition, we studied the W78A/F105A mutant of MRGBP which loses interaction with MRG15 and the W172A/Y235A mutant of MRG15 which loses its interaction with repair factors PALB2/BRCA2. Thus, these mutants would help to understand the function of MRG15 during DNA repair. The second part of my doctorate concerns the MBTD1 subunit. Indeed, we were interested in the fusion between MBTD1 and the splicing factor ZMYND11 found in cases of acute myeloid leukemia (AML). We then showed that the oncogenic mechanisms of this fusion are dependent on the delocalization of the NuA4/TIP60 complex on the bodies of the genes, leading to an increase of H4 acetylation. This generates a transcriptional alteration including overexpression of the Myc oncogene and deregulation of alternative splicing of specific transcripts. In addition, we have characterized the residues required for the interaction between MBTD1 and the EPC1 subunit, essential for the association of MBTD1 with the rest of the NuA4/TIP60 complex. Together, these results would allow the development of new therapeutic tools that can target MBTD1 to treat specific AML cases. All of this work provides a better understanding of the functions of the NuA4/TIP60 complex linked to its various subunits both at the transcriptional level but also in DNA repair. In addition, they establish the oncogenic mechanisms associated with this complex. Thus, future therapeutic strategies could be developed
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
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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