1,721,064 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
Study of the cell types involved in abdominal aortic aneurysms
No full textL’anévrysme de l’aorte abdominale (AAA) est une maladie vasculaire consistant en une dilatationde l’aorte abdominale. Son caractère asymptomatique rend importante la recherche debiomarqueurs afin de faciliter la prise en charge des patients.Le but de mes travaux de thèse a été d’étudier spécifiquement les types cellulaires impliqués dansl’AAA.Après obtention d’une banque d’échantillons d’AAA, nous avons localisé ces types cellulaires etrepéré 3 zones d’intérêt : le thrombus intraluminal contenait des neutrophiles, lymphocytes T,mastocytes et macrophages M2. Les macrophages M1 étaient localisés dans l’adventice, avec leslymphocytes B et des mastocytes. La média contenait des cellules musculaires lisses (CML) dont lephénotype variait entre les états sain, anévrysmal et apoptotique.Ces résultats suggérant une implication différente des deux types de macrophages et uneévolution des CML au cours de l’AAA, nous avons isolé ces deux types cellulaires du tissu anévrysmalpar microdissection laser afin d’y étudier l’expression de biomarqueurs potentiels. Nous avons ainsimontré que l’augmentation plasmatique de peroxiredoxine-1 provient des macrophages M1 et quel’augmentation d’ADAMTS5 provient des CML anévrysmales allongées.Nous avons ensuite comparé les protéomes des macrophages M1 et M2 afin d’élucider leur rôledans l’AAA et d’identifier de nouveaux biomarqueurs. Cinq protéines différentielles ont étéidentifiées impliquées dans la phagocytose ou la réponse au stress.L’étude des différents types cellulaires impliqués dans l’AAA pourrait nous permettre unemeilleure compréhension de ses mécanismes et l’identification de biomarqueurs potentiels de cettepathologie.Abdominal aortic aneurysm (AAA) is a vascular disease consisting in a dilatation of the abdominalaorta. As AAA is asymptomatic, it is important to identify new biomarkers in order to improve theearly care management of patients.The aim of this work was to study specifically the cell types involved in the development of AAA.After collection of an AAA samples bank, we located these cell types among the tissue andhighlighted 3 interesting areas: the intraluminal thrombus contained neutrophils, T lymphocytes,mast cells and M2 macrophages. M1 macrophages were located in the adventitia along with Blymphocytes and other mast cells. The media contained smooth muscle cells (SMC) with a phenotypevarying from a healthy state, to an aneurysmal one and to an apoptotic one.These results suggest a different role of the two subtypes of macrophages and an evolution ofSMCs during AAA. Thus, we chose to isolate these subtypes from the aneurysmal tissue with lasermicrodissection in order to study the proteins differentially expressed between them that could bepotential biomarkers. We showed that the plasmatic increase in peroxiredoxin-1 levels in AAApatients came from pro-inflammatory M1 macrophages and the increase in ADAMTS5 levels camefrom aneurysmal elongated SMCs.We then compared the whole proteome of M1 and M2 macrophages in order to elucidate theirrole in AAA and identify new biomarkers. Five differentially expressed proteins were identified,implicated in phagocytosis and stress response.The study of the different cell types involved in AAA could enable us a better understanding of itsmechanisms and allow the identification of new potential biomarkers for this patholog
Transcriptomic analysis of isolated vascular cells implicated in abdominal aortic aneuvrysm in human
No full textL'anévrysme de l'aorte abdominale (AAA) est un problème de Santé Publique qui touche principalement les hommes de plus de 65 ans. L'AAA souvent asymptomatique évolue vers la rupture associée à un taux de mortalité élevé. Parmi les acides ribonucléiques (ARNs) non codants, les microARNs (miARNs), stables dans le tissu et les biofluides, sont des candidats intéressant dans la recherche de biomarqueurs. L'inflammation, la dégradation de la matrice extra-cellulaire (MEC) et la raréfaction de la média participent à l'AAA. De nombreuses cellules inflammatoires sont impliquées dans l'AAA. La raréfaction des cellules musculaires lisses (CML) est secondaire à l'anoïkis, apoptose par détachement cellulaire de la MEC. Une analyse protéomique différentielle de CML en culture, issues de patients porteurs d'AAA, réalisée au laboratoire a montré que la désintégrine et metalloprotéinase avec un motif de thrombospondine 5 (ADAMTS 5) est surexprimée dans les CML de patients présentant un AAA. L'isolement des cellules par la microdissection laser permet de conserver le phénotype des cellules isolées et de mettre en évidence des marqueurs potentiels de l'AAA masqués par l'analyse du tissu global. Mon travail de thèse a consisté à partir des cellules isolées de la paroi anévrysmale de l'aorte abdominale sous-rénale chez l'Homme: à effectuer une analyse globale des miARNS et une analyse ciblée de l'ADAMTS 5, métalloprotéase qui a une action enzymatique sur les protéines de la MEC. Les objectifs de ce travail sont une meilleure compréhension de l'AAA et l'identification de nouveaux biomarqueurs.La distribution des cellules dans la paroi anévrysmale est étudiée par immunohistochimie sur des biopsies anévrysmales et d'aortes saine obtenues chez l'Homme. Les cellules localisées sont isolées par microdissection laser. L'analyse par criblage de l'expression des miARNs des cellules isolées de l'AAA et des CML issues d'aorte saine est réalisée sur puce. L'expression différentielle de miARNs sélectionnés est analysée par PCR quantitative dans des cellules isolées de l'AAA et dans du tissu global. L'expression des miARNs sélectionnés est ensuite comparée dans le plasma des patients présentant un AAA et de patients athérosclérotiques sans AAA par PCR pour identifier de potentiels biomarqueurs. Dans l'AAA, les macrophages M1 proinflammatoires sont retrouvés dans l'adventice et les macrophages M2 anti inflammatoires dans le thrombus intraluminal, les lymphocytes de type B sont retrouvés organisé en organe lymphoïde tertiaire adventitielle ou ATLOs dans 11 échantillons sur 20 analysés. Les CML sont rares et strictement localises au niveau de la média. Sur 850 miARNs testés dans la puce, 205 miARNs sont exprimés dans les cellules isolées. Les miR-29b et let-7f sont augmentés dans le plasma de patients porteurs d'AAA et représentent de potentiel biomarqueurs.L'expression d'ADAMTS 5 dans les CML de la paroi anévrysmale est évaluée par immunohistochimie dans la paroi aortique saine et anévrysmale et quantifiée par Western-blot dans les CML isolées de la paroi aortique saine et anévrysmale.Deux morphotypes de CML anévrysmales ont été identifiés: un morphotype arrondi positif au marqueur de l'apoptose, caspase 3 et un morphotype allongé, similaire aux CML de l'aorte saine. Le profil d'expression des sous-unités d'ADAMTS 5 est diffèrent dans les CML arrondies et les CML allongées anévrysmales et saines. La mise en apoptose des CML a été mise au point in vitro pour étudier les mécanismes impliqués dans les modifications d’ expression d'ADAMTS 5 dans l'AAA et les conséquences sur son action enzymatique.L'approche systématique de l'expression transcriptomique des cellules anévrysmales isolées a identifié des marqueurs potentiels de l'AAA, les miR-29b et let-7f et l'analyse ciblée suggère l'implication d'ADAMTS 5 dans le profil évolutif des CML vers l'anoïkis dans l'AAA. Des études complémentaires permettront une meilleure compréhension de l'AAA.Abdominal aortic aneurysm (AAA) is a public health problem, which mainly affects men older than 65 year. AAA are usually asymptomatic with a natural evolution towards rupture associated with a high mortality rate. Among non coding ribonucleic acids (RNAs), microRNAs are stable in tissue and biofluids and are interesting candidates for the search of biomarkers. Inflammation, extracellular matrix (ECM) degradation and media rarefaction are involved in AAA. Many inflammatory cells are involved in AAA. Anoikis is an apoptosis secondary to a cell detachment from ECM and is responsible for rarefaction of smooth muscle cells (SMC). Differential proteomic analysis of cultured SMC from AAA patients was performed in the laboratory and highlighted the overexpression of a disintegrin and metalloproteinase with thrombospondin motif of type 5 (ADAMTS 5) in SMC of AAA patients. Isolation of cells with laser microdissection allows to keep their phenotype and to find potential markers that may be masked by global tissue analysis.The aim of my PhD work was to perform a global miRNA screening of cells isolated from human aneurysmal wall and an analysis targeted on ADAMTS 5, a metalloprotease with an enzymatic activity on ECM proteins. The main objectives were a better understanding of AAA and the identification of new biomarkers.The distribution of cells in the aneurysmal wall was studied by immunohistochemistry in human aneurysmal and healthy aortic samples. Once located, the cells were isolated by laser microdissection and screened for miRNAs by microarrays. Differential expression of selected miRNAs was quantified by PCR in the cells isolated by laser microdissection and in whole aortas. They were then compared in plasma of AAA patients and atherosclerotic patients without AAA by quantitative PCR to identify potential biomarkers.In AAA, the M1 proinflammatory macrophages were located in the adventitia and the M2 antiinflammatory macrophages in the intraluminal thrombus; the type B lymphocytes were organized in tertiary lymphoid organs (ATLOs) in 11/20 of analysed samples. SMC were rare and restricted to the media. Among the 850 miRNAs tested on microarray, 205 miRNAs were detected in isolated cells. MiR-29b and let-7f were upregulated in plasma of AAA patients, and thus are potential biomarkers.The expression of ADAMTS 5 in aneurysmal SMC was evaluated by immunohistochemistry of healthy and aneurysmal aortic wall and quantified by Western blot in isolated SMC from healthy and aneurysmal wall.Two aneurysmal SMC morphotypes were identified: a rounded morphotype positive for caspase 3, an apoptotic marker, and a spindle-shaped morphotype similar to the healthy aortic SMC. The expression profile of ADAMTS 5 subunits was different in rounded SMC compared to aneurysmal and healthy spindle-shaped SMC. In vitro induction of apoptosis of SMC was established in order to study the mechanisms involved in ADAMTS 5 expression in AAA and their consequences on enzymatic actions.The global transcriptomic screening of aneurysmal cells isolated by laser microdissection has identified potential markers of AAA, miR-29b and let-7f. The targeted analysis suggested that ADAMTS 5 is involved in the evolution profile of SMC towards anoikis in AAA. Further investigations will allow a better understanding of AAA pathophysiology
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
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
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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