1,720,963 research outputs found

    Discrimination and Robustness Evaluation of Neuronal Responses of the Auditory System in Acoustic Degradation Situations

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    Ces travaux de recherche ont eu pour objectif d’évaluer les capacités de discrimination des réponses des neurones et leur robustesse dans le bruit à chaque étage du système auditif. Nous avons ainsi quantifié la capacité de discrimination neuronale entre quatre vocalisations cibles conspécifiques masquées par un bruit stationnaire depuis le noyau cochléaire jusqu’au cortex auditif secondaire chez le cobaye anesthésié. La discrimination des vocalisations cibles par les populations neuronales a été fortement diminuée par le bruit dans toutes les structures, mais les populations du colliculus inférieur et du thalamus ont montré de meilleures performances que les populations corticales. La comparaison avec les réponses neuronales obtenues avec les vocalisations vocodées (38, 20 ou 10 bandes de fréquences) a révélé que la réduction des capacités de discrimination neuronale était principalement due à l'atténuation des modulations d'amplitude lente (< 20 Hz). En outre, nous avons quantifié la robustesse des réponses neuronales grâce à une méthode de classification automatique réalisée sur l’ensemble des données obtenues en présence du bruit stationnaire et d’un autre bruit appelé chorus. Cela a mis en évidence cinq catégories de comportements neuronaux (des plus robustes aux plus sensibles) et leurs proportions respectives sur l’ensemble du système auditif ainsi qu’au sein de chaque structure auditive. Cette analyse a montré également qu’il existait des neurones robustes à tous les étages du système auditif, bien qu’une proportion plus importante soit retrouvée au niveau du colliculus inférieur et du thalamus. Par ailleurs, la proportion de neurones robustes est plus faible dans le bruit chorus ce qui laisse suggérer que ce dernier est plus pénalisant que le bruit stationnaire. Il est important de souligner qu’une proportion non négligeable de neurones sous-corticaux et corticaux changent de comportement d’un bruit à l’autre de sorte que le comportement de ces neurones dans un bruit particulier est peu prédictible. Ces résultats démontrent donc que la discrimination neuronale en situation de dégradation acoustique est principalement déterminée par l’altération des modulations lentes d'amplitude à la fois au niveau sous-cortical et cortical et suggèrent que les structures sous-corticales contribuent de façon importante à la perception robuste d’un signal cible dans le bruit.This research aimed at evaluating the discrimination abilities of neuronal responses and their robustness to noise at each stage of the auditory system, from the cochlear nucleus to the secondary auditory cortex. We quantified the neuronal discrimination performance between four conspecific vocalizations masked by a stationary noise in anesthetized guinea pig. Discrimination of target vocalizations by neuronal populations was significantly reduced by noise in all structures, but collicular and thalamic populations displayed better performance than cortical populations. The comparison with neuronal responses obtained with vocoded vocalizations (using 38, 20 or 10 frequency bands) revealed that the reduction in discrimination performance was mainly due to the attenuation of slow amplitude modulations (<20 Hz). In addition, we quantified the robustness of neuronal responses using an automatic classification method performed on the whole database obtained in presence of stationary noise and of another noise called “chorus” noise. This highlighted five categories of neural behavior (from robustness to sensitivity) and their respective proportions across the auditory system as well as within each auditory structure. This analysis demonstrated that robust neurons do exist at all stages of the auditory system, although a higher proportion was found in the inferior colliculus and thalamus. Moreover, the proportion of robust neurons is lower in the chorus noise, which suggests that the latter is more penalizing than the stationary noise. It is worth to point out that a significant proportion of subcortical and cortical neurons changed category from one background noise to another, so that the behavior of these neurons in a particular noise was unpredictable. These results provide clear evidence that neuronal discrimination in degraded acoustic conditions is mainly determined by alterations of slow amplitude modulations both at the subcortical and cortical level, and suggest that the subcortical structures significantly contribute to the robust perception of a target signal in noise

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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

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    We 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

    Author Index

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    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We 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 Under Sail The Imagination of Jack London, 1893-1902

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    In 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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