1,721,123 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
The role of P2Y11 receptor in the modulation of dendritic cell phenotype and cardiomyocyte survival during hypoxia/reoxygenation
No full textLes cellules dendritiques (DCs) possèdent des rôles clés dans la modulation de la réponse inflammatoire. Leur implication dans la réponse inflammatoire post-ischémie/reperfusion semble claire. Cependant, leurs rôles spécifiques restent encore à élucider. Nous avons émis l’hypothèse selon laquelle la modulation de la réponse des cellules dendritiques suite à la séquence d’ischémie/reperfusion pourrait diminuer les lésions du greffon cardiaque. L’objectif de ce travail a donc consisté en l’exploration et l’identification d’un mécanisme immunomodulateur dans la DC. Un modèle cellulaire d’hypoxie/réoxygénation (H/R) et un modèle de co-culture DCs / cardiomyocytes ont été utilisés.Dendritic cells (DCs) play key roles during the inflammatory process. Although their involvement in ischemia/reperfusion (I/R)-related inflammation is known, their specific role in such a context remain to be elucidated.We hypothesized that the modulation of DC phenotype during I/R might decrease cardiac graft injuries. In this study, we aimed to explore and identify an immunomodulatory mechanism in DCs. An in vitro model of hypoxia/reoxygenation (H/R) and a co-culture model were used. Our results highlight that the purinergic receptor P2Y11 (P2Y11R) exhibits an immunosuppressive role in DCs. This effect was lost when cells were subjected to a H/R insult, due to P2Y11R downregulation during hypoxia
Human peripheral blood mononuclear cells display a temporal evolving inflammatory profile after myocardial infarction and modify myocardial fibroblasts phenotype
No full textLors de l'infarctus du myocarde (IDM), la nécrose des cellules cardiaques est à l'origine d'une réaction inflammatoire stérile qui contribue, à terme, au développement d'une cicatrice fibreuse du myocarde. Cette réponse, particulièrement décrite dans les modèles animaux, se déroule en trois étapes et implique des modifications phénotypiques des cellules immunitaires et des fibroblastes cardiaques, évoluant dans le temps. Elle débute par une phase inflammatoire, suivie par une phase de réparation et se termine par une phase de maturation de la cicatrice fibreuse. Les facteurs responsables de cette réponse inflammatoire sont mal connus mais pourraient impliquer certains récepteurs purinergiques, en particulier P2Y11 connu pour ses propriétés immunomodulatrices, et une polarisation particulière de la réponse lymphocytaire T CD4.L'objectif de notre travail était de caractériser le profil de réponse immuno-inflammatoire de patients au décours de l'IDM et de mettre au point un modèle de coculture in vitro impliquant les cellules immunitaires des patients et des fibroblastes cardiaques humains pour étudier leurs interactions.Les cellules mononucléées du sang périphérique (PBMC) ont été collectées chez 178 patients à différents temps après un infarctus du myocarde, de l'angiographie réalisée à la phase aiguë jusqu'à un an après l'IDM. Les niveaux d'expression de P2Y11 et de gènes impliqués dans le profil pro-tolérogène des cellules dendritiques et dans la polarisation de la réponse lymphocytaire T ont été évalués par RT-qPCR et le niveau d'expression protéique de P2Y11 des PBMC a été analysé par cytométrie en flux. Des expériences de coculture entre les PBMC de patients et une culture primaire de fibroblastes cardiaques humains ont été réalisés et la différenciation myofibroblastique évaluée par l'expression des protéines α-SMA et vimentine après 24 heures de coculture, par cytométrie en flux.Les PBMC collectées dans les 48 premières heures après l'IDM présentaient une augmentation du niveau d'expression des gènes de tolérogénicité HMOX1 et STAT3 et de CD4 et une diminution du gène IDO1 et du ratio TBX21/GATA3. Ces mêmes PBMC présentaient une augmentation du niveau d'expression génique de P2RY11 et de l'expression protéique dans les lymphocytes T et B. In vitro, les PBMC collectées dans les 48 premières heures induisaient une augmentation du ratio α-SMA/vimentine dans les fibroblastes cardiaques humains après 24 heures de coculture.Ces résultats suggèrent que le profil inflammatoire des cellules immunitaires circulantes évolue dans le temps chez l'Homme après un IDM avec un profil de type réparateur précoce, et qu'elles semblent capables de sécréter des médiateurs solubles induisant une différenciation des myofibroblastes, participant ainsi au processus de fibrose myocardique.During acute myocardial infarction (AMI), cardiomyocytes necrosis induces a sterile inflammatory response. Pathophysiology of this response has been studied in rodent models and described as a three-stage model involving temporal phenotypic modifications of both immune cells and fibroblasts: a primary inflammatory phase, followed by a reparative phase and a fibrous scar maturation phase. Factors involved in this inflammatory response are not well understood and could imply the participation of some purinergic receptors, particularly the P2Y11 receptor known for its immunomodulatory properties, and a specific T cell polarization.For the first time, we characterized the immuno-inflammatory and P2Y11 expression profiles of peripheral blood mononuclear cells (PBMC) collected in patients after AMI and analyzed the consequences of presenting these cells to cardiac fibroblasts in vitro.PBMC from 178 patients were collected at various times after reperfused ST-segment elevation AMI, from H0 to M12. Expression levels of P2RY11 and genes involved in tolerogenic profile of dendritic cells and T cell polarization were evaluated by RT-PCR; and P2Y11 protein expression was assessed by flow cytometry. PBMC and human cardiac fibroblasts (HCF) were cocultured and fibroblasts differentiation into myofibroblasts was analyzed by flow cytometry using α-SMA/vimentin ratio.Within the first 48 hours after AMI, expression levels of HMOX1, STAT3 and CD4 increased while IDO1 and TBX21/GATA3 ratio decreased. Concomitantly, the expression of P2RY11 increased in both T and B cells. In vitro, PBMC collected at H48 after AMI induced an increase in α-SMA/vimentin ratio in HCF.Our results suggest that human PBMC display an evolving inflammatory profile with reparative characteristics the first two days after AMI and secrete soluble mediators leading to the myofibroblastic differentiation, thus participating to myocardial fibrosis
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
Intercellular signaling and P2Y11 purinoceptor implication after myocardial ischemia/reperfusion injury
No full textLes lésions d’Ischémie/Reperfusion (I/R) contribuent à la physiopathologie de l’infarctus du myocarde. Le stress induit par l’I/R entraîne la mort des cardiomyocytes, une forte réponse inflammatoire de type stérile et la mise en place d’un processus de réparation impliquant les fibroblastes cardiaques. Il a précédemment été montré au laboratoire que l’activation du récepteur purinergique P2Y11 par l’ATP diminuait la sécrétion d’IL-6 et d’IL- 12 par la cellule dendritique (DC), permettant une diminution de la polarisation vers une réponse adaptative Th1. Nous avons donc émis l’hypothèse que la signalisation purinergique pouvait également moduler la mortalité des cardiomyocytes et l’activation des fibroblastes cardiaques après I/R, en diminuant la mise en place de réponses cellulaires délétères à long terme pour l’organe. L’objectif de cette thèse a été de déterminer in vitro le rôle de la signalisation purinergique sur la réponse des cardiomyocytes et des fibroblastes cardiaques à l’Hypoxie/Réoxygénation (H/R). Nous avons pu montrer que l’activation des récepteurs purinergiques au moment de la réoxygénation, en particulier du récepteur P2Y11, permettait de réduire la mortalité des cardiomyocytes après H/R. Nous avons ensuite montré que la stimulation de P2Y11 au moment de la réoxygénation diminue la prolifération des fibroblastes cardiaques et leur switch phénotypique en myofibroblastes, mais aussi diminue leur sécrétion de facteurs pro-inflammatoires. Le sécrétome des fibroblastes cardiaques a également induit une diminution de la sécrétion d’IL-6 et d’IL-12 par les DC, ainsi qu’une diminution de la mortalité des cardiomyocytes soumis à une H/R. Ces effets immunomodulateurs et cardioprotecteurs étaient dépendants de l’activation du récepteur P2Y11 sur les fibroblastes cardiaques. Ces résultats suggèrent fortement que le récepteur P2Y11 est au centre des réponses cellulaires post-H/R, et que le cibler in vivo à la reperfusion pourrait améliorer le pronostic clinique des patients atteints d’infarctus du myocarde.Ischemia/Reperfusion injuries are involved in the pathophysiology of myocardial infarction. I/R-induced stress leads to massive cardiomyocyte death, an acute inflammatory response and the establishment of a repair process by cardiac fibroblasts. Previous work in the laboratory showed that P2Y11 purinergic receptor activation by ATP decreased IL-6 and IL-12 secretion by dendritic cells (DC), inducing a decrease in polarization towards Th1 response. We hypothesized that purinergic signaling could also modulate cardiomyocyte death and activation of cardiac fibroblasts responses to hypoxia/reoxygenation (H/R). We showed that the activation of purinergic receptors at the onset of reoxygenation, especially P2Y11 receptor, improved cardiomyocytes survival following H/R. We then showed that P2Y11 stimulation at the onset of reoxygenation decreased cardiac fibroblasts proliferation and their phenotypic switch into myofibroblasts, but also decreased their secretion of pro-inflammatory factors. Cardiac fibroblasts secretome reduced IL-6 and IL-12 secretion by DC, and cardiomyocyte mortality. These immunomodulatory and cardioprotective effects were dependent on P2Y11 receptor activation in cardiac fibroblasts. These results suggest that P2Y11 receptor is strongly involved in post- H/R cellular responses, and that targeting this receptor in vivo could improve the clinical prognosis of patients with myocardial infarction
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
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