1,720,955 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
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
Optimisation du système d'édition génique CRISPR-Cas
No full textDéveloppé en 2012, le système CRISPR-Cas a d'ores et déjà révolutionné les sciences du vivant en démocratisant l'édition du génome grâce à sa simplicité d'usage, sa forte efficacité et son adaptabilité. Néanmoins, l'efficacité et la précision de ce système varient grandement ce qui peut freiner ou empêcher sa mise en place. Mes travaux de doctorat se sont articulés autour de ces deux thématiques. L'édition du génome à l'aide de nucléases artificielles repose sur l'activation des voies de réparation de la cellule par induction d'une cassure double brin (DSB) dans l'ADN. Le système CRISPR-Cas est composé d'une nucléase (Cas) associée à un ARN guide qui se lie à la séquence ciblée par appariement de base. Une fois la DSB induite par la nucléase, plusieurs mécanismes de réparation entrent en compétition pour réparer la cassure. La réparation par jonction d'extrémités non-homologues (NHEJ) peut entrainer l'insertion de mutations ce qui permet de réaliser des inactivations de gène alors que la réparation par recombinaison homologue (HDR) permet des corrections ou insertions précises. Les stratégies les plus répandues pour améliorer l'efficacité de l'édition génique reposent sur l'utilisation de marqueurs de sélection. Néanmoins, ces marqueurs peuvent influencer la physiologie des cellules et leur utilisation n'est pas envisageable dans un cadre thérapeutique. Pour y remédier nous avons développé une méthode de cosélection sans marqueur se basant sur la création d'un allèle à gain de fonction. En modifiant le gène ATP1A1 encodant pour la pompe Na+/K+ ATPase par NHEJ et HDR nous avons conféré une résistance à l'ouabaïne aux cellules tout en conservant la fonctionnalité de la pompe. En ciblant simultanément le gène ATP1A1 et un gène d'intérêt, le traitement des cellules à l'ouabaïne permet de sélectionner les cellules résistantes et enrichir la population en cellules génétiquement modifiées dans le gène d'intérêt. Nous avons obtenu des augmentations drastiques de l'efficacité de NHEJ et de HDR et la cosélection à l'aide de Cas12a permet d'enrichir facilement et simultanément de multiples cibles. La méthode est simple et rapide à mettre en place et nous avons démontré sa versatilité en l'appliquant à diverses lignées cellulaires dont les cellules souches et progénitrices hématopoïétiques couramment utilisées en thérapie génique ex vivo, ce qui permet d'envisager de futures applications thérapeutiques. Notre stratégie a été déployée dans de nombreux laboratoires depuis sa publication et, de manière significative, elle a également été utilisée pour enrichir les événements de réparation des éditeurs de base et éditeurs par transcriptase inverse (prime editing) et pourrait aussi être applicable aux futurs outils d'édition du génome. La HDR est la voie privilégiée pour des perspectives thérapeutiques. Néanmoins, la NHEJ est la voie de réparation majoritaire dans les cellules humaines et la recombinaison homologue n'est active que lors des phases S et G2 du cycle cellulaire. La fusion de Cas9 avec le dégron de la géminine a permis de restreindre son activité aux phases S, G2 et M du cycle cellulaire et augmenter sensiblement le ratio de réparation par HDR. Parallèlement à la réplication de l'ADN, la recombinaison homologue présente un pic d'activité en milieu de phase S puis son activité diminue. Nous avons émis l'hypothèse que restreindre l'activité de la nucléase à la phase S permettrait d'augmenter davantage le ratio de réparation par HDR. Néanmoins, aucun dégron existant ne permet une dégradation lors des phases G1, G2 et M. Le système d'identification Fucci se base sur la fusion de dégrons à des protéines fluorescentes pour marquer les différentes phases du cycle cellulaire. Afin de développer un nouveau dégron permettant d'améliorer les systèmes Fucci et CRISPR, nous nous sommes intéressés à SLBP, une protéine active uniquement lors de la phase S. Nous avons caractérisé son dégron et l'avons utilisé afin de développer une sonde fluorescente spécifique de la phase S dont le profil d'expression a été confirmé par cytométrie en flux et microscopie en temps réel. Le marquage précis de la phase S pourrait notamment aider à élucider les voies de réparation de l'ADN. Nous avons également démontré que la fusion d'un de nos dégrons avec SpCas9 permet d'augmenter le taux de réparation par HDR de manière plus significative que le dégron de la géminine. Il sera intéressant d'évaluer sa synergie avec d'autres stratégies d'optimisation du système CRISPR.Developed in 2012, the CRISPR-Cas system has rapidly revolutionized life sciences and is routinely used in research laboratories worldwide. Its efficiency, simplicity and versatility greatly facilitate gene editing and functional genomics. However, the variability of its precision and efficiency is a major concern since it restrains its implementation, especially for therapeutic use. My PhD investigations revolves around these challenges. Gene editing through artificial nucleases relies on inducing a double-strand break (DSB) in the DNA to activate cellular repair pathways. For CRISPR-Cas systems, targeting is realised through base pairing between the targeted sequence and a guide RNA that associates with the Cas nuclease, making the design of new guides a simple process. Once the nuclease has elicited the DSB, several repair mechanisms compete to repair the break. Non-homologous end joining (NHEJ) can lead to mutations in the targeted sequence and allows gene knock-out while homology-directed repair (HDR) permits precise corrections or insertions. The most common strategy to enrich for cells that have undergone the desired genetic modification relies on the use of selection markers. However, since these markers can impact cell physiology, they are not suitable for therapeutic use. To address this issue, we have developed a marker free co-selection method based on the creation of a gain of function allele. By targeting ATP1A1, the gene encoding for the Na+/K+ ATPase pump, we conferred resistance to ouabain to the cells by either NHEJ or HDR while conserving the pump properties. Simultaneous targeting of ATP1A1 and a gene of interest followed by cell treatment with ouabain allows enrichment for cells genetically modified in the gene of interest. We observed a drastic improvement in efficiency for both NHEJ and HDR events and several targets can be enriched simultaneously and easily by exploiting Cas12a multiplexing capabilities. It's a simple and fast strategy and we have demonstrated its versatility by modifying various cell lines including hematopoietic and progenitor stem cells, commonly used in ex vivo gene therapy, demonstrating therapeutic potential. Since its publication, the ATP1A1 co-selection strategy has been exploited in numerous laboratories and successfully applied to enrich for base and prime editors' modifications and it could as well be applied to future genome editing tools, further demonstrating its versatility. Due to its fidelity, HDR is the preferred pathway for potential therapeutic use. Nevertheless, NHEJ is the major repair mechanism in human cells and homologous recombination is only active during S and G2 cell cycle phases. Although inhibiting NHEJ or promoting HDR by targeting proteins involved in these pathways is greatly efficient, the efficiency variability between cell lines and toxicity is considerable. Fusing Cas9 to the geminin degron restricts its activity to the S, G2 an M phases and slightly improves the HDR ratio. Alongside DNA replication, homologous recombination activity is thought to peak in the mid S phase and decline during G2 phase. We hypothesized that restricting Cas9 nuclease expression to the S phase will further bias repair towards HDR. However, no degron allowing G1, G2 and M phases degradation has been developed yet. The Fucci system is based on the fusion between degrons and fluorescent proteins to distinguish the different cell cycle phases but lack an S-phase specific probe. To improve cell cycle identification and HDR ratio, we decided to develop a degron allowing such a regulation. In that order, we studied the stem-loop binding protein (SLBP) which bind histone mRNAs and is only active during S phase and is degraded in other phases. We analysed SLBP endogenous expression pattern, characterised its degron, and used it to engineer an S-phase specific probe that we named Fucci-S. K562 and HeLa S3 cells constitutively expressing Fucci-S probe were created and their fluorescence expression pattern were analysed by FACS and live cell microscopy to confirm its S-phase specificity. Combined with the Fucci probes it allows to differentiate all the cell cycles phases and could be used in developmental and DNA repair studies. Fusing one of our newly developed degrons to SpCas9 increases HDR ratio more than the geminin degron. Additional studies would allow to establish its range of use and how it synergizes with other CRISPR-Cas optimisation strategies
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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