1,721,089 research outputs found
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
Expression and aggregation of α-synuclein and Tau in the enteric nervous system under inflammatory conditions
No full textLes synucléinopathies et les tauopathies sont des maladies neurodégénératives caractérisées par une accumulation anormale et une agrégation des protéines α-synucléine et Tau, respectivement. La neuroinflammation joue un rôle central sur les fonctions physiologiques et l’agrégation de ces deux protéines. Parallèlement, au cours de la maladie de Parkinson, on retrouve les inclusions d’α-synucléine tout au long du tractus digestif et de nombreuses études ont mis en évidence la présence d’une inflammation intestinale chez les patients parkinsoniens. Dans ce contexte, nous avions émis l’hypothèse que l’inflammation intestinale pourrait altérer la régulation de ces deux protéines, mener à leur agrégation et possiblement leur propagation vers le SNC, et que le concept de synucléinopathie entérique pourrait s’étendre aux tauopathies. Ainsi, les objectifs de notre projet visaient à étudier le rôle de l’inflammation intestinale aiguë et chronique sur la régulation et l’agréation de l’α-synucléine et Tau. Nous avons montré, in vitro et in vivo, qu’une inflammation intestinale aiguë régulait à la baisse l’α-synucléine via une voie p38 dépendante. Inversement, dans des biopsies de patients Crohn, nous avons observé une régulation à la hausse de l’α-synucléine et de Tau, en l’absence de formes pathologiques. Cette régulation n’était pas liée à un mécanisme transcriptionnel mais serait due à une diminution de la dégradation de ces deux protéines via une voie NRF2/NDP52 dépendante. Ainsi, nos travaux suggèrent que l’inflammation intestinale altère l’expression de ces deux protéines clés et pourrait, sur le long terme, participer à leur pathogénicité.Synucleinopathies and tauopathies are neurodegenerative diseases characterized by abnormal accumulation and aggregation of the proteins α-synuclein and Tau, respectively. Neuroinflammation plays a central role in the physiological functions and aggregation of these two proteins. During Parkinson's disease, α-synuclein inclusions are found throughout the digestive tract and many studies have shown the presence of intestinal inflammation in Parkinson's patients. In this context, we hypothesized that intestinal inflammation could alter the regulation of these two proteins and that the concept of enteric synucleinopathy could extend to tauopathies. Thus, the objectives of our project aimed to study the role of acute and chronic intestinal inflammation on the regulation and aggregation of α-synuclein and Tau. We have shown, in vitro and in vivo, that acute intestinal inflammation downregulates α-synuclein via a p38 pathway, and that this regulation is specific to enteric neurons. On the other hand, in biopsies of Crohn’s disease patients, we have observed an upregulation of α-synuclein and Tau, in the absence of pathological forms. This regulation was not linked to a transcriptional mechanism but to a decrease in the degradation of these two proteins throughout a NRF2/NDP52 pathway. Therefore, our work suggests that intestinal inflammation dysregulates the expression of these two key proteins and could, in the long term, contribute to their pathogenicity
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
Enteric LRRK2 : a link between Parkinson’s disease and Crohn’s disease ?
No full textLRRK2 est un gène impliqué dans la maladie de Parkinson (MP) ainsi que dans la maladie de Crohn (MC). Bien qu’a priori sans rapport, ces deux pathologies partagent en fait une part de phénotype commun au niveau digestif, marqué notamment par une inflammation et un métabolisme altéré de l’α-synucléine. Dans ce contexte, nous avons émis l’hypothèse que Lrrk2 entérique pourrait être un maillon moléculaire commun aux mécanismes pathologiques des MC et MP. Pour tester cette hypothèse, nous avons entrepris d’étudier Lrrk2 dans des biopsies coliques de patients atteints des MC ou MP, ainsi que de sujets témoins. Nous avons montré que Lrrk2 était exprimée dans le SNE (ganglions myentériques et sous-muqueux), aussi bien par les neurones que par les cellules gliales entériques (CGE). Nous avons observé une augmentation de l’expression de Lrrk2 entérique dans la muqueuse/sous-muqueuse de la MC qui contraste avec la baisse d’expression et d’activité kinase de Lrrk2 dans la MP. Pour préciser l’implication du système nerveux entérique (SNE) dans ces résultats, nous avons quantifié l’expression de Lrrk2 dans les ganglions du SNE. Aucune différence n’a été observée entre des patients parkinsoniens et des sujets témoins. Nous avons également mis en lumière un mécanisme de régulation transcriptionnelle de LRRK2 par la voie AMPc dans les CGE. Au total, nos données humaines originales, générées à la fois en conditions physiologique et pathologique, nous permettent de proposer des hypothèses sur les rôles distincts que pourrait tenir Lrrk2 entérique dans les MP et MC.Leucine-rich repeat kinase 2 (LRRK2) is genetically associated with both Parkinson's disease (PD) and Crohn's disease (CD). Besides the genetics aspects, these two seemingly unrelated disorders also share common features such as gastrointestinal (GI) inflammation, epidemiological links and impaired α-synuclein metabolism. These observations suggest that Lrrk2 may sit at the crossroads between PD, CD and GI inflammation. The aim of the current research was therefore to study the expression levels and kinase activity of Lrrk2 in the GI tract in both pathological and physiological conditions. We first showed that the two main ganglia of the enteric nervous system (ENS), namely the myenteric and submucosal ganglia expressed Lrrk2, both in enteric neurons and glial cells. We further showed that Lrrk2 expression levels were increased in colonic biopsies from CD patients, sharply contrasting with the decrease in Lrrk2 levels and kinase activity observed in PD samples. In order to get a more precise view on the involvement of the ENS, we quantified Lrrk2 expression levels in ENS ganglia, but didn’t find any difference between PD patients and non-neurodegenerative controls. In addition, we also showed that Lrrk2 expression was tightly regulated by the cAMP pathway in enteric glial cells. Taken as a whole, our data provide new insights into the possible role of Lrrk2 in the GI tract in both physiological and pathological conditions
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
Parkinson’s disease spreading to the autonomic nervous system : a pathophysiological study
No full textAu-delà de la triade motrice liée à la dégénérescence de la substance noire, les symptômes non moteurs dans la maladie de Parkinson (MP) reflètent une large diffusion du processus pathologique (agrégation d’alpha-synucléine). Ainsi, la dysautonomie, les troubles du sommeil ou les troubles cognitifs sont fréquents au cours de la MP, la constipation et le trouble du comportement en sommeil paradoxal (TCSP) pouvant même précéder les signes moteurs. Le tractus digestif pourrait jouer un rôle dans la pathogénie de la MP. L’objectif de ce travail de thèse était d’explorer l’atteinte du système nerveux autonome (SNA) dans l’histoire naturelle de la MP. Nous avons réalisé une exploration fonctionnelle et morphologique de la barrière épithéliale intestinale sur des biopsies coliques. Nous avons montré une désorganisation structurale des jonctions serrées, non corrélée à la synucléinopathie dans le système nerveux entérique. Chez des patients parkinsoniens avec et sans TCSP, marqueur de sévérité de la MP et de diffusion au tronc cérébral, nous avons étudié la perméabilité et la charge lésionnelle entériques. La perméabilité ne différait pas, mais la synucléinopathie était plus fréquente chez les patients avec TCSP, supportant l’existence de formes plus diffuses de MP. Enfin, nous avons réalisé une étude systématique du SNA par des explorations cliniques, fonctionnelles et histologiques (biopsie cutanée). L’atteinte des modalités du SNA montrait une distribution hétérogène, suggérant une progression éparse et erratique. Seules la constipation et l’hypotension orthostatique étaient associées à une altération cognitive, confirmant leurs liens avec la sévérité de la maladie.Beyond cardinal motor symptoms due to the degeneration of substantia nigra neurons, non motor symptoms are major features of Parkinson’s disease (PD), displaying the large spread of alpha-synuclein histopathology. Dysautonomia, sleep problems or cognitive alteration are frequent in PD; constipation and rapid eye movement sleep behavior disorder (RBD) may even precede motor symptoms for years. Gastrointestinal tract might be involved in PD pathogenesis. The aim of the current research was to explore the autonomic nervous system (ANS) in the natural history of PD. We first performed a functional and morphological study of the intestinal epithelial barrier (IEB) in colonic biopsies. We observed a structural disorganization of tight junction, unrelated to ENS alpha-synuclein pathology. In PD patients with and without RBD, a disease severity and brainstem diffusion marker, we evaluated IEB permeability and enteric alpha-synuclein pathology. No difference in IEB permeability was observed between the two groups, but ENS alpha-synuclein pathology was more frequent in PD patients with RBD, suggesting that RBD may mark a more widespread alpha-synuclein-driven pathophysiology. Finally, we undertook a systematic assessment of ANS components, with clinical, functional and histological (skin biopsy) measures. ANS components were impaired in a heterogeneous pattern, thereby suggesting an erratic rather than a stepwise progression. Only constipation and orthostatic hypotension were associated with cognitive alteration, which reinforce their relationship with disease severity
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