1,721,153 research outputs found

    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

    Cholecystokinin and drug abuse : mRNA regulation in drug dependence and alteration of emotional responses after AAV2-shRNA-mediated knock-down in the mouse basolateral amygdala

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    La cholecystokinine (CCK) est un peptide neuromodulateur largement distribué dans le cerveau, lié à de nombreuses fonctions physiologiques telles que l’anxiété, la dépression, les processus mnésiques et les réponses motivationnelles, mais les régions cérébrales exprimant la CCK impliquées dans ces processus sont peu connues. Nous avons montré que le gène de la CCK est régulé par les récepteurs aux opioïdes mu, dans la mesure où l’expression de son ARNm a montré d’importantes modifications dans l’amygdale étendue centrale suite à un traitement à la morphine. Le but de cette thèse a été d’étudier la régulation transcriptionnelle de la CCK en réponse à la morphine dans le cerveau de souris, et d’examiner localement l’implication de la CCK dans les réponses émotionnelles. A l’aide d’une cartographie par autoradiographie quantitative, nous avons trouvé une tendance à l’augmentation de la régulation de mcck dans le cortex cingulaire et l’amygdale basolatérale (BLA) chez des souris abstinentes pour la morphine. Ensuite, nous nous sommes concentrés sur la BLA, fortement impliquée dans la genèse des états émotionnels, et avons démontré qu’une inactivation fonctionnelle de la CCK par des vecteurs viraux (shCCK) dans cette région réduit fortement les niveaux d’anxiété et les comportements de désespoir. Nos données indiquent que la CCK de l’amygdale joue un rôle déterminant dans les effets anxiogéniques et dépressifs connus pour la CCK. Ainsi, dans un contexte d’abus de drogues, nos résultats, combinés avec la description préalable de symptomes de type dépréssif lors de l’abstinence, suggèrent que la CCK de l’amygdale peut contribuer à l’état dépressif caractérisant l’abstinence.Cholecystokinin (CCK) is a neuromodulatory peptide widely distributed in the mammalian brain and related to a variety of physiological functions, including anxiety, depression, memory processes and motivational responses. CCK-expressing brain regions involved in these effects remain unclear and their identification represents an important step towards understanding CCK function in the brain. We had identified CCK as a mu-opioid dependent gene which mRNA showed remarkable modifications in the central extended amygdala, a neuroanatomical entity implicated in drug seeking and relapse, upon morphine treatment. Therefore, the aims of this thesis were to further investigate CCK transcriptional regulation in response to morphine throughout the mouse brain, and to examine the implication of local CCK in emotional responses. Using a quantitative autoradiographic mapping methodology, we found trends for mcck up-regulation in morphine-abstinent mice in the Cingulate Cortex and the basolateral amygdala (BLA), consistent with the established existence of depressive-like symptoms under this state. Then, we focused in the BLA, which is strongly involved in the generation of emotional states, and we found that virally-mediated shCCK knockdown in this region strongly reduces levels of anxiety and despair behavior, as evidenced in the elevated plus-maze and forced swim test, respectively. Altogether, our data indicate that amygdalar CCK represents a key substrate for anxiogenic and depressant effects of neural CCK, and in the context of drug abuse, our results combined with preliminary data, suggest that amygdalar CCK may contribute to the depressive state that characterizes abstinence

    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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    Déficits émotionnels dans l'abstinence à l'héroïne : mécanismes moléculaires et nouveaux gènes

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    L'addiction est une affection chronique emmaillée de rechutes, caractérisée principalement par des comportements compulsifs de recherche et de consommation de drogue. Il s'agit d'une pathologie grave et fréquente. Les sujets qui parviennent à se désengager de ces compulsions sont considérés comme abstinents. Les études épidémiologiques montrent que l'abstinence, notamment pour les opiacés est fortement associée à une prévalence accrue de la dépression. Le but de mon travail de thèse était d'aborder spécifiquement la cooccurrence des troubles dépressifs et addictifs. J'ai participé à l'élaboration d'un modèle murin de cette comorbidité, et nous nous sommes focalisés sur l'addiction aux opiacés, en particulier l'héroïne. Suite à un traitement chronique par l'héroïne et au cours de l'abstinence paraissent progressivement des comportements apparentés à la dépression. Ce traitement chronique à l'héroïne modifie le fonctionnement du système sérotoninergique et l'activité du récepteur opioïde kappa (Article publié: Distinct mu, delta, and kappa opioid receptor mechanisms underlie low sociability and depressive-­like behaviors during heroin abstinence). Les déficits comportementaux observés peuvent être prévenus et reversés par un traitement antidépresseur ciblant le system sérotoninergique ou en inhibant l'activité du récepteur opioïde kappa avec un antagoniste, dans des portions similaires (Manuscript submis: Kappa opioid receptor antagonism prevents and reverses heroin abstinence-­induced social deficit with similar efficacy compared to chronic antidepressant treatment). Notre étude nous permet de proposer que le récepteur opioïde kappa constitue un acteur majeur à l'interface de l'addiction et de la dépression(Revue publié: The kappa opioid receptor: from addiction to depression, and back).Addiction is a chronic, relapsing disorder and is mainly described as compulsive craving and consumption of a drug in spite of adverse consequences. Individuals who have achieved to refrain from such compulsive behaviour are considered abstinent, but present symptoms reminiscent of depression. Epidemiological studies report that abstinence, particularly from opiates, strongly associates with higher prevalence of depression. Aim of my thesis was to specifically address the co-­occurrence of opiate addiction and major depression in preclinical research. Thus, I have contributed to develop a mouse model of opiate abstinence, and in particular extend our model of morphine abstinence to heroin. Following exposure to escalating doses of heroin, abstinent mice progressively exhibit a depressive-­like phenotype, revealed by low sociability., and show altered serotonergic and kappa opioid receptor signaling (Published article: Distinct mu, delta and kappa opioid receptor mechanisms underlie low sociability and depressive-­like behaviors during heroin abstinence).Importantly, these behavioural deficits can be both prevented and reversed by antidepressant treatment targeting serotonergic signaling, or inhibiting the activity of the kappa opioid receptor withan antagonist, with similar efficacy (Submitted article: Kappa opioid receptor antagonism prevents and reverses heroin abstinence-­induced social deficit with similar efficacy compared to chronic antidepressant treatment). Altogether, our results allow us to propose the kappa opioid receptor is a major player at the interface of addiction and depression (Published review: The kappa opioid receptor: from addiction to depression, and back)

    Comorbidity between opiate addiction and depression : serotonergic mechanisms in a mouse model

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    L’addiction ou dépendance aux substances psychoactives est une affection chronique, fréquente et grave, émaillée de rechutes et de périodes d’abstinence. Les études épidémiologiques montrent que l’abstinence aux opiacés est fortement associée à une prévalence accrue de la dépression. Nous résumons ici les principaux aspects cliniques de la dépendance aux opiacés et de la dépression, en détaillant leurs mécanismes physiopathologiques. Puis, nous présentons notre modèle d’abstinence aux opiacés chez la souris. Suite à un traitement morphinique chronique et au cours de l’abstinence apparaissent progressivement des comportements apparentés à la dépression. Ce traitement morphinique modifie profondément le fonctionnement du système sérotoninergique, notamment dans le noyau du raphé dorsal. De plus, les déficits comportementaux observés peuvent être prévenus par un traitement chronique par la fluoxétine, un antidépresseur ciblant ce système. Nous avons généralisé ce modèle à l’héroïne, un autre opiacé illicite. Nous avons révélé par des approches génétiques de délétion constitutive et conditionnelle les rôles distincts des 3 récepteurs opioïdes (mu, delta et kappa) lors de l’abstinence à l’héroïne. Enfin, nous avons initié une étude de caractérisation, à l’échelle de l’ensemble du génome, des adaptations transcriptomiques (ARN messagers et micro-ARN) dans le noyau du raphé dorsal au cours de l’abstinence à l’héroïne et du traitement antidépresseur. Ce travail devrait permettre d’améliorer notre compréhension des mécanismes neurobiologiques à l’œuvre dans la comorbidité entre dépendance aux opiacés et dépression et pourrait suggérer de nouvelles pistes thérapeutiques.Addiction is a chronic, frequent and serious brain disease, with relapse alternating with abstinence periods. Epidemiological studies show that abstinence, notably from opiates, is strongly associated with depression.Here we present the main clinical aspects of opiate addiction and depression, and most recent advances in molecular pathophysiology of both disorders. Then, we present our mouse model of opiate abstinence. Following chronic morphine exposure, depressive-like behaviours progressively emerge. Morphine treatment profoundly disrupts serotonergic signalling, notably in the dorsal raphe nucleus. In addition, behavioural deficits can be prevented by chronic treatment with fluoxetine, an antidepressant targeting serotonergic neurons. We then generalized our mouse model to heroin, another major illicit opiate. Using constitutive and conditional knockout strategies, we documented distinct roles for all 3 opioid receptors (mu, delta and kappa) in heroin abstinence. Finally, we initiated a large-scale analysis of transcriptomic regulations (mRNA and micro-RNA) occurring in our model as a function of heroin abstinence and fluoxetine treatment.These studies should reveal an unforeseen contribution of the dorsal raphe nucleus to addiction. They should uncover new molecular mechanisms underlying depressive-like behaviors in mice during opiate abstinence and thus put forward new therapeutic targets in humans

    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
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