1,720,969 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
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
Diversity of endospore-forming bacteria in sediment as a proxy for environmental lake history
No full textThèse de doctorat : Université de Neuchâtel, 2013Les lacs une grande importance écologique et économique, mais ils sont aussi très vulnérables aux pressions anthropogéniques (pollution; surpêche), aux changements climatiques et à l'eutrophisation (hautes concentrations de nutriments). Pour une gestion environnementale et la mise en place de mesures de conservation, les dynamiques des écosystèmes lacustres doivent être connues et les conditions biologiques de référence doivent être établies afin de mesurer dans le futur la santé écologique des lacs. Les conditions biologiques de références, comme les connaissances de la biodiversité et les réponses des écosystèmes aux perturbations environnementales sont fournies par les sédiments, qui sont des archives idéales des conditions du passé. Cette thèse présente la recherche sur la détection et la diversité des bactéries sporulantes et leur usage comme indicateurs des conditions écologiques du lac Léman (France-Suisse) au cours des 100 dernières années. Les endospores sont des structures résistantes qui sont produites par un groupe de bactéries dans des conditions de stress. Les endospores dormantes sont déposées avec le sédiment et sont des capsules biologiques qui reflètent les conditions environnementales au moment de leur sédimentation. Les approches métagénomiques sont des études de séquençage du métagénome entier qui se trouve dans un échantillon environnemental. Une approche ciblée est réalisée uniquement sur une partie de la communauté (fraction ciblée). Ces approches métagénomiques ciblées augmentent la couverture de séquençage et également la résolution de détection de taxons. Elles résolvent donc les problèmes connus des approches métagénomiques globales. Deux méthodes de métagénomique ciblée ont été développées au cours de cette thèse pour étudier la diversité des bactéries sporulantes dans les sédiments. La première méthode est basée sur des amorces moléculaires dessinée pour amplifier un fragment du gène spo0A, gène spécifique aux bactéries sporulantes codant pour le facteur de transcription de la sporulation. De plus, une méthode optimisée d'extraction d'ADN pour les bactéries sporulantes a été développée. En appliquant ces méthodes, la diversité des cellules végétatives des bactéries sporulantes ainsi que les endospores dans le sédiment peut être étudiée. La deuxième méthode de métagénomique ciblée est une méthode de traitement avec chaleur et agents chimiques pour détruire les cellules végétatives, qui sont fragiles, comparé aux endospores qui résistent au traitement. Avec cette méthode, la diversité seule des endospores peut être évaluée. Le traitement pour détruire les cellules végétatives est efficace, 90% des séquences détectées sont classifiées comme bactéries sporulantes. Avec une approche globale, seulement 10% des séquences détectées sont classifiées comme bactéries sporulantes. De plus, la résolution a été augmentée, en détectant jusqu'à 10 fois plus de taxon. La meilleure résolution permet de détecter 34 genres de bactéries sporulantes non révélés avec l'approche globale, dont certain genres qui ont été définis comme étant asporogénique, comme Ethanoligenens et Trichococcus. D'autres séquences ont pu être classifiées au niveau de l'espèce comme Bacillus longiquaesitum ou Clostridium bowmanii. Les méthodes métagénomiques ciblées ont été appliquées à une carotte de sédiment du Lac Léman, qui couvre la période de 1921 à 2010. Une diversité extraordinaire de bactéries sporulantes a été observée dans ces sédiments. Il y a des fluctuations importantes dans la diversité au cours des 100 dernières années. Prioritairement les changements de diversité peuvent être liée à l'eutrophisation du lac de 1960 à 1990, mais aussi au métabolisme du soufre, la charge de matière organique d'origine terrestre ou à des évènements climatiques. La communauté bactérienne dans la période eutrophe a changé vers une dominance de bactéries anaérobies comme les Clostridia, qui reflètent les conditions anoxiques de la surface du sédiment pendant cette période. Les avantages du traitement pour séparer les endospores des cellules végétatives sont que ces deux fractions peuvent être analysées individuellement. Avec ces différentiations, des genres actifs dans le sédiment comme Clostridium et Heliobacterium peuvent être relevés. Par contre, il y a toute une fraction diversifiée d'endospores dormantes qui est présente en faible nombre, jusqu'à ce que les conditions environnementales changent en leur faveur ou elles deviennent dominantes. Des exemples de ce phénomène ont été observés pour les genres Desulfotomaculum, Sporomusa et Brevibacillus. Les nouvelles méthodes de métagénomique ciblée qui ont été développées dans le cadre de cette thèse sont des améliorations importantes pour étudier la diversité des bactéries sporulantes à haute résolution. Les données acquises pendant cette recherche amènent de nouvelles informations sur le rôle des bactéries sporulantes dans les sédiments et en général sur les bactéries des sédiments lacustres. Cette étude est aussi la première étude sur la diversité des bactéries sporulantes par des méthodes de séquençage et la première étude d'utilisation des endospores comme indicateur paléolimnologique., Freshwater systems are of high ecological and economical importance but at the same time subjected to anthropogenic pressure such as input of pollutants, overfishing, changes in climate regime, and eutrophication (high nutrient input). For environmental management and the implementation of conservation measures, the dynamics of freshwater ecosystems need to be known and biological reference conditions have to be established against which future changes can be measured. Baseline knowledge about biodiversity and ecosystem responses to environmental perturbations in lakes can be obtained from the sediments that provide an ideal environmental archive of past conditions. This thesis presents research on the diversity detection of bacterial endospores, and its use as proxy to reconstruct the environmental history of the last 100 years of Lake Geneva at the border of France and Switzerland. Endospores are resistant structures formed when bacteria are under stress. Once these endospores are deposited in the sediment they remain dormant and serve as natural biological time capsules, archiving the conditions at the time of sedimentation. To infer the diversity of endospores, two specific methods for targeted metagenomics were developed and validated in sediments. Metagenomics is a sequencing approach of the entire genetic pool directly retrieved from an environmental sample. Similarly, targeted metagenomics is based on a targeted genetic pool, for example a sub-community of the sample. Targeted metagenomics increases the sequencing coverage and resolution of detection, circumventing common problems of traditional metagenomics studies. For this work the endospore-forming bacterial community was targeted. The first targeting method was based on a molecular marker for endospore-forming bacteria, the global transcription regulator of sporulation (spo0A). After an optimized DNA extraction method for endospores in sediment, where biomass was separated from the sediment particles (indirect DNA extraction), and the spo0A gene fragment was amplified and sequenced. With this method, the diversity of the endospore-forming bacteria (vegetative cells and endospores) in sediments was determined. The second targeting method consisted of a treatment to separate the endospores from vegetative cells, prior to DNA extraction and sequencing. The goal of the treatment was to destroy vegetative cells that are generally more fragile, while leaving the more resistant endospores intact. With this method, the diversity of only the endospores in sediment was detected. The treatment to separate endospores was successful, as shown by an enrichment of endospore-forming bacteria from 10% abundance in the global approach to over 90% abundance in the targeted metagenome. Also the resolution was improved to up to 10-fold increase in detected endospore-forming taxa. The better resolution led to the detection of 34 genera unique to the targeted metagenome, including some supposedly asporogenic groups like Ethanoligenens and Trichococcus and high numbers of sequences that could be classified to a species level such as Bacillus longiquaesitum or Clostridium bowmanii. The application of targeted metagenomics to a sediment core retrieved from Lake Geneva spanning a time period from 1921 to 2010, revealed substantial diversity of endospore-forming bacteria in sediments. The diversity fluctuated significantly in the last 100 years, reflecting the eutrophication period from 1960 to 1990 as well as sulphate metabolism, input of terrestrial organic matter, and specific climate events. The shift in the community composition during eutrophication was linked to a dominance of anaerobic Clostridia-like members that reflect anoxic sediment conditions during this time. The advantage of the treatment is that the communities in vegetative cell state can be differentiated from the communities present as dormant endospores. Using this differentiation we report activity of selected endospore-forming bacteria in sediment, for example members from genus Clostridium and Heliobacterium at the sediment surface. In contrast, a small fraction of dormant endospores present at high diversity represent the microbial seed bank. This group of bacteria is inactive for long periods of time but selected members can propagate and become dominant if the environmental conditions change to their favour, as was observed in this study for Desulfotomaculum, Sporomusa or Brevibacillus. The novel targeted metagenomics approaches developed here provide a significant experimental improvement to explore the diversity of endospore-forming bacteria at high resolution. The data provides knowledge on the role of endospore-forming bacteria in freshwater sediment and on freshwater sediment bacteria in general. It is also the first report of metagenomics to reveal the diversity of endospores in sediment and the use of endospores as paleolimnological proxies
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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