1,721,033 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
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
Conception of a natural vascular substitute, fonctionnalized by a polyelectrolyte multilayer film and cellularized by an autologous endothelium
No full textLes taux élevés de mortalité et de morbidité associés aux maladies vasculaires en font des pathologies dont les conséquences physiopathologiques, chirurgicales et socio-économiques sont d’une importance majeure pour le système de santé. Malgré leurs avantages, la disponibilité limitée des vaisseaux autologues a conduit au développement de prothèses synthétiques. Cependant, leur surface hautement thrombogène limite leur utilisation dans la substitution des vaisseaux de petit calibre (< 6 mm). De ce fait, à cause de leur obstruction précoce, la reconstitution d’une surface luminale proche de l’endothélium natif est incontournable. Pourtant, les revêtements de surface actuellement disponibles possèdent de médiocres qualités de rétention des néo-endothélium lorsqu’ils sont soumis à des contraintes de cisaillement physiologiques. Dans ce travail, nous proposons un substitut vasculaire de petit calibre endothélialisé réalisé à partir de trois éléments : 1) une matrice préparée à partir d’une artère ombilicale désendothélialisée, 2) un recouvrement de surface innovant constitué du film multicouche de polyélectrolytes (MPE) (PAH-PSS)3-PAH, et 3) un néo-endothélium constitué de cellules endothéliales matures ou progénitrices. Les études in vitro menées sur ces substituts ont montré que la formation, la rétention sous contraintes de cisaillement et la fonctionnalité du néoendothélium élaboré sur la surface luminale étaient améliorées par le film MPE. L’implantation du substitut par pontage termino-latéral sur le lapin a montré que le cahier des charges imputé aux substituts de petit calibre était rempli, principalement en termes de perméabilité et de diamètre, mais aussi de résistance à la suture et aux infections. En conclusion, le film MPE favorise le développement d’un substitut vasculaire de petit diamètre perméable à « long » terme et qui pourrait répondre aux exigences des chirurgiensVascular diseases with their high rate of mortality and morbidity belong to the pathologies involving important socio-economic factors for health system. Despite the advantages of autografts, the limited availability of autologous vessels has led to the development of synthetic prostheses. However, their high thrombogenic surface limits their use as small calibre vascular substitutes (< 6 mm). To prevent narrowing of small diameter vascular grafts, the reconstruction of a luminal surface close to the native endothelium is essential. However, the retention of the neo-endothelium subjected to shear stress is poor on the coatings currently available. In this work, we developed a small calibre endothelialized vascular substitute thanks to three elements: 1) a natural matrix prepared from umbilical artery, 2) an innovative coating based on the polyelectrolytes multilayer film (PEM) (PAH-PSS)3-PAH, and 3) used for cell culture of mature or progenitor endothelial cells. In vitro studies have shown that the formation, the retention under shear stress and the endothelial function of the neoendothelium on the luminal surface were improved by PEM film. The anastomosis of this substitute on rabbits has shown that the specifications essential to small calibre vascular grafts were reached, mainly in terms of permeability and diameter but also of resistance to suture and infections. In conclusion, PEM films helped us to develop a small diameter vascular substitute with long term patenc
Relationship between EC/blood substitutes : implication of shear stress or hypoxia, and evaluation of new generation hemoglobin cytotoxicity
No full textLes substituts sanguins à base d’hémoglobine (HBOC) en cours de développement et d’évaluation, sont susceptibles, selon leur formulation et le protocole d’évaluation envisagé, d’induire des modifications du comportement des cellules endothéliales (CE). Nous avons développé des protocoles visant à évaluer le rôle de trois paramètres : les contraintes de cisaillement, l’hypoxie et la présence d’HBOC au contact des CE. Plusieurs facteurs, comme le stress oxydatif, la vasomotricité et l’inflammation ont été étudiés par qPCR, RPE, cytométrie en flux et dosage des métabolites. Dans un premier temps, nous avons observé l’action simultanée des contraintes de cisaillement et des HBOC (Hb-Dex-BTC, Oxyglobin®, aa-Hb) sur le comportement des CE. Nos résultats montrent combien le cisaillement influence la réponse des CE en présence d’HBOC. Pour se rapprocher de la situation clinique d’un usage potentiel d’HBOC, nous avons élaboré un protocole d’hypoxie/réoxygénation des CE par ces Hb. Au travers des deux protocoles d’hypoxie développés (brève et chronique), nous avons montré des mécanismes différents de réponse cellulaire : après 4 h, la réoxygénation avec les substituts induit une diminution de l’inflammation engendrée par l’hypoxie. Alors qu’après 24 h, nous constatons son induction quel que soit le substitut utilisé. D’une façon générale, la présence de dextran dans l’Hb-Dex-BTC rend celle-ci plus furtive vis-à-vis des mécanismes de détection de la présence d’Hb par les CE. Dans une dernière partie, nous avons effectué des tests de cytotoxicité sur des Hb de nouvelle génération (PEG-Hb et Hb octamérique produite par génie génétique) par mesure de la viabilité cellulaire et du taux d’apoptose-nécrose, Ces résultats encourageants confirment l’intérêt de poursuivre les évaluations.Hemoglobin based oxygen carriers (HBOC), under development and evaluation, are potentially able to induce modifications of endothelial cells (EC) behaviour. We developed protocols to evaluate the role of three different parameters, like shear stress, hypoxia and HBOC presence on EC. Several factors, like oxidative stress, vasomotion and inflammation were studied using qPCR, EPR, flow cytometry and metabolites quantification. At first, we observed simultaneously the action of shear stress and HBOC (Dex-BTC Hb, Oxyglobin®, aa-Hb) on EC behaviour. Our results show how shear stress influences EC response face to HBOC. Then, we elaborated a hypoxia/reoxygenation protocol with HBOC. Using two different protocols of hypoxia (brief and chronic) we demonstrated that different mechanisms drive cell response. After 4 h of hypoxia, reoxygénation with blood substitutes induces a diminution of the inflammation engender by hypoxia. However, after 24 h of hypoxia, we observed an over inflammation whatever was the blood substitute used. In conclusion, among the three HBOC tested, we highlighted that the presence of dextran in Dex-BTC-Hb solutions makes Hb furtive for EC Hb detection mechanisms. Finally, we developed cytotoxicity tests on new Hb generation (PEG-Hb, octameric Hb) based on cellular viability and apoptosis-necrosis. These tests were encouraging for both Hb
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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