1,720,973 research outputs found
Mortalité de masse et infection bactérienne chez les bivalves : liens avec la physiologie larvaire et l'environnement bactérien chez deux espèces d'huîtres commerciales
Full text linkRÉSUMÉ: L'émergence de la mortalité est un phénomène récurrent en écloserie de bivalves.
Celle-ci est le plus associée à une modification des conditions de cultures des larves qui
favorise la prolifération de bactéries opportunistes. L'impact de ces bactéries sur la
physiologie larvaire est encore mal connu. C'est pourquoi dans ce projet, nous avons
décidé de documenter les relations qui peuvent exister entre la physiologie larvaire,
l'environnement bactérien et l'apparition de la mortalité chez deux espèces d'huîtres,
Crassostrea virginica et C gigas. Pour cela, la thèse a été axée autour de deux
expériences principales où les larves ont été mises en culture dans des environnements
bactériens différents. La première expérience avait pour objectif de suivre le
développement de larves d'huîtres américaines (C virginica) cultivées en présence ou
non d'un antibiotique non sélectif. L'antibiotique a été utilisé dans cette expérience pour
pouvoir générer des environnements bactériens différents, l'un où la charge et la
prolifération bactérienne est limitée par le traitement à l'antibiotique, et l'autre où les
bactéries peuvent se développer sans contraintes. Dans la deuxième expérience,
l'environnement bactérien des larves d'huîtres du Pacifique (C gigas) a été modifié par
l'ajout ou non d'un pathogène connu dans les bassins de culture (challenge bactérien).
Dans les deux expériences, la physiologie larvaire a été abordée par l'étude du contenu en
lipides, du métabolisme, du stress oxydatif et de l'immunité, grâce à une approche
multidisciplinaire comprenant des analyses enzymologiques, biochimiques et
moléculaires. De plus, afin d'avoir une vision globale de la qualité de l'élevage, ces
analyses ont été complétées par des mesures des taux de survie, de croissance et des
niveaux d'alimentation. Des analyses microbiologiques ont également été effectuées pour
caractériser l'environnement bactérien des larves. Les résultats obtenus pour ces deux
expériences, nous ont permis de caractériser des changements physiologiques associés
d'une part à la dégradation des conditions de culture des larves et à l'apparition d'une
mortalité de masse (première expérience), et d'autre part, à une exposition à un pathogène
(deuxième expérience). Dans les deux situations, nous avons pu mettre en évidence que
l'apparition de la m0l1alité était associée à (1) une baisse de l'activité alimentaire, (2) un
niveau métabolique plus faible, (3) la consommation des réserves énergétiques, (4) une
modification de la composition en acides gras des lipides polaires, (5) un stress cellulaire
plus important, (6) l'activation des défenses antioxydantes et des mécanismes de
cytoprotection, et (7) à l'activation de la réponse immunitaire. De par son caractère
intégratif, cette étude a permis d'avoir une vision plus large des changements
physiologiques associés à l'apparition de la mortalité en écloserie d' huîtres, ce qui ouvre
la voie à de futures études qui auront pour objectifs de mieux comprendre l'impact
physiologique des pathologies chez les larves de bivalves. -- ABSTRACT: The emergence of mortality is a recurrent event in bivalve hatchery, often linked to
the modification in the culture environment of larvae in Iink to proliferation of
opportunistic bacteria. The impact of these bacteria on larval physiology is weakly
understood. We investigated the relationships between larval physiology, bacterial
environ ment and the occurrence of mortality in two oyster species, Crassostrea virginica
and C. gigas. This thesis was realised around two main experiments where larvae were
reared in different bacterial environments. The objective of the first experiment was to
follow the larval development of American oysters reared in presence or not of nonselective
antibiotic. Antibiotic was used to generate different environments, one where the
bacterial load and the opportunistic proliferation were restricted by the antibiotic treatment,
and another where bacteria could develop without restriction. In the second experiment, the
bacterial environment of larvae was modified by addition or not of know pathogens for
oyster larvae. In both experiments, 1arval physiology was investigated by the
multidisciplinary study of the lipids content, the metabolism, the oxidative stress and the
immunity, with the use of enzyme, biochemical and molecular analyses. Moreover, to have
an overall vision of larval culture, these analyses were supplemented by the measurements
of survival rates, growth and feeding activity. Microbiological analyses were also
performed to characterize the bacterial environment of larvae. The results acquired in this
project, allowed us to understand the changes in physiology of oyster larvae in contact to
bacterial environmental changes associated to mass mortality (first experience) or directly
during exposition to pathogen bacteria (second experience). In both situations, the
appearance of mortality was associated to (l) a feeding activity decline, (2) a weaker
metabolic level, (3) the consumption of energy reserves, (4) changes in fatty acids profiles
of the polar lipids, (5) a higher oxidative stress, (6) the activation of antioxidant defenses
and cytoprotection, and (7) in the activation of immune response. The integrative approach
of this study provides an overview of the physiologie al meehanisms of oyster larvae related
to pathogen and mass mortality
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
- …
