1,720,978 research outputs found
Inter-individual variability and temporal scaling in the aging transcriptome
No full textGràcies als amplis esforços d'investigació, la nostra comprensió dels mecanismes fisiològics de l'envelliment ha progressat enormement. Recentment, les tecnologies òmiques han permès l'estudi a tot el genoma dels canvis relacionats amb l'edat. No obstant això, les anàlisis òmiques sovint passen per alt la naturalesa estocàstica, dinàmica i complexa de l'envelliment. Per aquest motiu, desenredar les relacions causa-efecte s'ha demostrat difícil. En aquesta tesi, analitzem l'efecte de l'envelliment sobre el transcriptoma en Caenorhabditis elegans, estudiant els canvis en l'expressió gènica a mesura que varien i covarien entre individus, al llarg del temps, i en resposta a múltiples intervencions que modulen la longevitat. En primer lloc, hem desenvolupat un protocol d'ARN-seq d'individus únics que ens permet mesurar la variabilitat transcriptòmica interindividual. Hem trobat que les diferències interindividuals en la mida dels teixits són el principal contribuent a la variabilitat transcriptòmica interindividual. Després de tenir en compte aquestes diferències, hem utilitzat la covariabilitat interindividual per reconstruir una xarxa de coexpressió gènica. Aquesta xarxa ens ha permès identificar mòduls funcionals alterats per la senyalització de la insulina/IGF-1. En segon lloc, hem fet servir un sistema degron induïble per auxina per comparar la dinàmica temporal de l'envelliment i l'expressió gènica en nou poblacions que envelleixen a diferents velocitats. Hem recopilat mesures transcriptòmiques temporals i trobem que només el cinc per cent de les trajectòries transcriptòmiques es reescalen temporalment a la par que la longevitat. En tercer lloc, hem col·laborat amb un laboratori que treballa amb la prohibitina, una proteïna mitocondrial que pot allargar o escurçar la longevitat segons el context. Hem trobat canvis coordinats en l'expressió gènica en múltiples soques compromeses metabòlicament que poden explicar aquests efectes dependents del context. Per concloure, presentem noves maneres de relacionar la longevitat i els canvis transcriptòmics, proporcionant així una visió de com les intervencions de modulació de la longevitat afecten l'envelliment.Thanks to extensive research efforts, our understanding of the physiological mechanisms underlying aging has immensely progressed. Recently, omics technologies have enabled the genome-wide study of age-related changes. Nevertheless, omics analyses often overlook the stochastic, dynamic, and complex nature of aging. Consequently, untangling cause-effect relationships has proven challenging. In this thesis, we analyze the effect of aging on the transcriptome in Caenorhabditis elegans, studying gene expression changes as they vary and covary between individuals, over time, and in response to multiple lifespan-modulating interventions. First, we developed a single individual RNA-seq protocol that allows us to measure inter-individual transcriptomic variability. We found that inter-individual differences in tissue size are the main contributor to inter-individual transcriptomic variability. After accounting for these differences, we utilized inter-individual covariability to reconstruct a gene co-expression network. This network allowed us to identify functional communities altered by insulin/IGF-1 signaling. Second, we used an auxin-inducible degron system to compare the temporal dynamics of aging and gene expression across nine differentially aging populations. We collected time-resolved transcriptomic measurements and found that only five percent of transcriptomic trajectories are temporally rescaled in the same way as lifespan. Third, we collaborated with a laboratory working on prohibitin, a mitochondrial protein that can extend or shorten lifespan depending on the context. We found coordinated changes in gene expression across multiple metabolically compromised strains that may explain context-dependent effects. To conclude, we present novel ways to relate lifespan and transcriptomic changes, thus providing insight on how lifespan-modulating interventions ultimately impact aging.Programa de doctorat en Biomedicin
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
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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