1,720,964 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Transport du manganèse chez Arabidopsis : Régulation post-traductionnelle du transporteur de manganèse NRAMP1
No full textManganese (Mn) is an essential metallic micronutrient for all living organisms. In plants, it acts as a cofactor for many enzymes involved in major metabolic pathways. However, the bioavailability of Mn in the soil is variable and its deficiency or excess can be limiting for plant growth. In order to adapt to these fluctuations, plants benefit from many transporters controlling root absorption of Mn and its distribution to the various organelles of the cell. The maintenance of Mn cellular homeostasis relies notably on the regulation of the localization or activity of these transporters. In Arabidopsis thaliana, high-affinity Mn uptake is mainly mediated by the transporter NRAMP1, whose subcellular localization depends on the metal availability. NRAMP1 is stabilized at the cell surface under Mn starvation and rapidly cycles between the plasma membrane and the endosomes in response to Mn excess through a phosphorylation-dependent mechanism.Based on this knowledge, my thesis work aimed to deepen the characterization of NRAMP1 post-translational regulatory mechanisms in response to Mn in Arabidopsis. The objective of my first research axis was to determine the involvement of ubiquitination in the regulation of NRAMP1 and to identify the enzymes and transporter residues involved in this process. My second research axis aimed to identify kinases controlling NRAMP1 phosphorylation and to characterize the context and the role of these mechanisms in the regulation of the transporter in response to Mn. During my thesis, I used a wide spectrum of biochemical, proteomic and site-directed mutagenesis strategies to answer these questions. In order to identify enzymes involved in the ubiquitination or phosphorylation of NRAMP1, I sought for protein partners of the transporter through interactome-based untargeted approaches and candidate gene approaches. The latest focused on the calcium-activated CIPKs and CPKs kinases families and established CIPK23 as a main candidate. In vitro phosphorylation experiments coupled with reverse genetics approaches allowed me to demonstrate that CIPK23 phosphorylates Ser20 and 499 on the N- and C-termini of NRAMP1. Physiological analyzes led me to the conclusion that CIPK23 is likely to control the activity of the transporter depending on the Mn status of the plant. Thus, my research on NRAMP1 regulation by phosphorylation and ubiquitination has contributed to a better understanding of the complex mechanisms supporting Mn homeostasis in plants.Le manganèse (Mn) est un micronutriment métallique essentiel pour l’ensemble des organismes vivants. Chez les plantes, il intervient comme cofacteur de nombreuses enzymes impliquées dans des voies métaboliques majeures. La biodisponibilité du Mn dans le sol est cependant variable et sa carence, comme son excès, peuvent constituer des facteurs limitants pour la croissance des plantes. Afin de s’adapter à ces fluctuations, celles-ci bénéficient d’une multitude de transporteurs contrôlant l’absorption racinaire du Mn et sa distribution vers les différents organites de la cellule. Le maintien de l’homéostasie cellulaire du Mn repose notamment sur la régulation de la localisation ou de l’activité de ces transporteurs. Chez Arabidopsis thaliana, l’absorption de Mn à haute affinité est principalement assurée par le transporteur NRAMP1, dont la localisation subcellulaire dépend de la disponibilité du métal. Le transporteur est stabilisé à la surface des cellules en condition de carence et cycle rapidement entre la membrane plasmique et les endosomes face à un excès de Mn selon un mécanisme phosphorylation-dépendant.Sur la base de ces connaissance, mes travaux de thèse ont visé à approfondir la caractérisation des mécanismes de régulation post-traductionnelle de NRAMP1 en réponse au Mn chez Arabidopsis. L’objectif de mon premier axe de recherche a été de déterminer l’implication de l’ubiquitination dans la régulation de NRAMP1 et d’identifier les enzymes et résidus du transporteur impliqués dans cette régulation. Mon second axe de recherche a visé à identifier les kinases contrôlant la phosphorylation de NRAMP1 et caractériser le contexte et le rôle de ces mécanismes dans la régulation du transporteur en réponse au Mn. J’ai employé au cours de ma thèse un large spectre d’approches biochimiques, protéomiques et de mutagénèse dirigée afin de répondre à ces questions. Afin d’identifier des enzymes impliquées dans l’ubiquitination ou la phosphorylation de NRAMP1, j’ai cherché à recenser les partenaires protéiques du transporteur au travers d’approches sans à priori de type interactome et d’approches gènes candidats. Ces dernières se sont concentrées sur les familles de kinases CIPKs et CPKs activées par le calcium et ont permis d’établir CIPK23 comme candidate principale. Des expériences de phosphorylation in vitro couplées à des approches de génétique inverse m’ont ensuite permis de démontrer que cette kinase phosphoryle les Ser20 et 499 N- et C-terminales de NRAMP1. Des analyses physiologiques m’ont amené à la conclusion que CIPK23 est susceptible de contrôler l’activité du transporteur en fonction du statut Mn de la plante. Mes recherches sur la régulation de NRAMP1 par phosphorylation et ubiquitination ont ainsi contribué à une meilleure compréhension des mécanismes complexes soutenant l’homéostasie du Mn chez la plante
Variations on the Author
Get PDF“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
Get PDFWe 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
Get PDFWe 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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