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Le modèle des ganglions de la base revisité par l'étude neuronale unitaire des projections striatofuges et de leur contenu neurochimique chez la souris
No full textLes ganglions de la base (GB) sont un ensemble de structures sous-corticales qui régulent le comportement psychomoteur. Le striatum (STR) constitue la principale structure intégratrice des ganglions de la base. Il contient des neurones de projection (MSN), dont une moitié exprime le récepteur dopaminergique D₁ et l'autre moitié exprime D₂. Le modèle anatomique des GB repose sur la ségrégation des projections axonales efférentes du striatum en voie directe et en voie indirecte. Selon ce schème organisationnel, la voie directe est constituée de MSN D₁ exprimant substance P (SP) et dynorphine (DYN) dont l'axone cible le noyau entopédonculaire (ENT) et la substance noire réticulée (SNr). Les MSN D₂ sont à l'origine de la voie indirecte, expriment l'enképhaline (ENK) et ciblent le globus pallidus(GP). Des reconstructions axonales unitaires ont toutefois démontré qu'un même axone de MSN puisse projeter dans toutes les structures cibles du STR. Ces résultats vont à l'encontre du modèle binaire et suggèrent que les voies directe et indirecte ne soient pas aussi ségréguées que ce que le modèle laisse présager. Les travaux de recherche présentés dans ce mémoire visent à quantifier le degré de collatéralisation axonale des MSN D₁ et D₂ dans les différentes cibles du STR, ainsi qu'à élucider la distribution neuropeptidique au sein de ces axones striatofuges, et ce, chez la souris. L'hypothèse proposée implique que l'axone d'un même MSN D₁ ou D₂ puisse se projeter dans les trois cibles du STR via un jeu complexe de collatérales axonales, mais que son contenu neuropeptidique puisse être libéré différentiellement dans ces structures cibles. Les résultats obtenus indiquent que, bien que la grande majorité des MSN D₁ ou D₂ possèdent des collatérales axonales dans toutes les cibles, les axones D₁ ne libèrent de la DYN que dans l'ENT et la SNr, alors que les axones D₂ ne libèrent leur ENK que dans le GP. Ces résultats mettent en doute la validité du modèle binaire de l'organisation anatomique et fonctionnelle des GB et exposent un substratum morphologique pouvant expliquer la neuroplasticité adaptative qui caractérise ces structures sous-corticales.The basal ganglia (BG) consist of a set of subcortical structures that regulate psychomotor behaviour. The striatum (STR) constitutes the main integrative structure of the BG. It is mostly composed of GABAergic medium spiny projection neurons (MSNs), of which one half expresses the dopamine receptor D₁ and the other half expresses D₂. The anatomical model of the BG, commonly used to explain the functioning of these subcortical structures, is based on the segregation of efferent axon projections from the STR into a direct pathway and an indirect pathway. According to this organizational scheme, the direct pathway is composed of D₁ MSNs expressing the neuropeptides substance P (SP) and dynorphin (DYN) whose axon directly targets the outputs of the BG - the entopeduncular nucleus (ENT) and the substantia nigra pars reticulata (SNr). D₂ MSNs give rise to the indirect pathway, express enkephalin (ENK) and target the globus pallidus (GP). Single-cell axon reconstructions have however shown that single MSN striatofugal axons project to all target structures of the STR (GP, ENT, SNr). These results are at odds with the binary model and rather suggest that the direct and indirect pathways are not as segregated as this model lets on. The research works presented in this thesis aim to quantify the degree of axonal collateralization of D₁ and D₂ MSNs projecting to the different target structures of the STR, and to elucidate the neuropeptide distribution within these striatofugal axons, in mice. The proposed hypothesis implies that the axon of a single D₁ or D₂ MSN projects to all STR targets through a complex set of axon collaterals, while its neuropeptide contents are released differentially into these target structures. Our data indicate that, while the vast majority of D₁ or D₂ MSNs possess axon collaterals that innervate all targets, D₁ axons release DYN only in the ENT and SNr, and D₂ axons release ENK only in the GP. These results challenge the validity of the binary model of the anatomical and functional organization of the BG and expose a morphological substratum that may explain the adaptive neuroplasticity that characterizes these subcortical structures
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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