1,721,314 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Pharmacological activity of polyphenolic derivatives from Malaysian Clusiaceae and Calophyllaceae : regulatory effects on inflammatory and immune endothelial markers
No full textAfin d’identifier de nouveaux composés prévenant la dysfonction et l’immunogénicité des cellules endothéliales qui sont impliquées dans la survenue des rejets de greffe,nous nous sommes intéressés aux métabolites secondaires de différentes espèces de Clusiaceae et de Calophyllaceae. Tout d’abord, 4 extraits DCM de Calophyllaceae malaisiennes ont été sélectionnés sur la base d’une étude déréplicative et d’un criblage biologique anti-inflammatoire. Puis, l’étude phytochimique de l’extrait de fruits de Mesua lepidota a permis d’isoler 9 coumarines de type mammea, dont 7 constituent 2 nouvelles séries : Les lépidotols et les lépidotines. L’étude des extraits de 2 lots de feuilles de Calophyllumtetrapterum a quant à elle conduit à l’isolement de dérivés polyphénoliques distincts : Desacylphloroglucinols polyprénylés dans le lot A, dont le composé majoritaire, la tétraptérone, est un dérivé acide original, et des pyranochromanones acides dans le lot B, dont un nouveau dérivé appelé acide tétraptérique. Le même protocole appliqué à l’extrait de feuilles de Mesuaassamica a montré que les fractions cytotoxiques sont riches en xanthones, tandis que les fractions anti inflammatoires renferment des coumarines de type mammea. Parallèlement à ces études phytochimiques, un panel de polyphénols représentatifs des classes chimiques retrouvées dans les Clusiaceae et les Calophyllaceae ont été évalués pour leurs effets sur divers marqueurs endothéliaux de l’inflammation et de l’immunité. Il apparaît ainsi que les coumarines de type mammea et la guttiférone J, une benzophénone polyprénylée, inhibent significativement l’expression de VCAM-1 ainsi que des molécules HLA de classe II, HLAE et MICA.In order to identify new compounds preventing endothelial cells dysfunction and immunogenicity which are involved in the emergence of graft rejection, the secondary metabolites of different Clusiaceae and Calophyllaceae specious were investigated. Firstly 4DCM extracts originating from Malaysian Calophyllaceae specious were selected through a dereplication analysis combined with an anti-inflammatory screening. Then, the phytochemical study of the fruits extract of Mesualepidota allowed us to isolate 9 mammea coumarins, among which 7 represent 2 novel series, i.e. lepidotols and lepidotins. The phytochemical study of 2 different batches of Calophyllum tetrapterum leaves led to the isolation of distinct polyphenolic derivatives : polyprenylated acylphloroglucinols were identified in batch A, with the major compound, tetrapterone, as a new acid derivative, whilst chromanone acids were identified in batch B, including a new derivative named as tetrapteric acid. The same protocol applied to Mesuaassamica leave extract showed that cytotoxic fractions were rich in xanthones whereas anti-inflammatory fractions contained numerous mammea coumarins. Along with these phytochemical studies, a panel of polyphenols representative of the chemical classes generally identified in Clusiaceae and Calophyllaceae specious were evaluated for their effects on various endothelial markersof inflammation and immunity. Mammea coumarins and guttiferone J, a polyprenylated benzophenone, appeared to significantly inhibit the expression of VCAM-1 as well as that of HLA class II molecules, HLA-E and MICA
Chemical characterization and biological valorisation of propolis extracts
No full textLa propolis est une substance résineuse collectée par les abeilles sur certaines parties des végétaux. Sa composition en métabolites secondaires est alors variable puisqu’elle dépend notamment de la flore locale près du site de collecte. Dans cette étude, la caractérisation chimique d’un échantillon représentatif de la propolis française de l’entreprise ‘‘Ballot-Flurin Apiculteurs’’ a conduit, au moyen d’analyses HPLC/DAD/MS et RMN 1D & 2D, à l’identification de 51 composés dont deux sont originaux. Les acides et esters phénoliques ainsi que les flavonoïdes identifiés dans cette propolis indiquent qu’elle appartient au type "peuplier". L’évaluation des activités biologiques de différents extraits et composés isolés a montré que cette propolis, qui possède une bonne activité antioxydante (DPPH et ORAC) associée à un potentiel antiglycant (anti-AGEs) très intéressant, représente un bon candidat pour la prévention des maladies, telles que le diabète, impliquant les AGEs. Elle montre également de bonnes activités antifongiques, sur deux levures du genre Candida, et antibactériennes sur Staphylococcus aureus et ses souches résistantes et sensibles à la méticilline, ces dernières étant responsables, à l’heure actuelle, de nombreuses infections nosocomiales. Une étude de variabilité inter-lots ainsi qu’un travail d’optimisation du procédé d’extraction industriel par plan d’expériences ont également été réalisés (partie confidentielle). Enfin, l’analyse de trois autres propolis, provenant d’Amérique Latine (Mexique) et d’Afrique (Côte d’Ivoire et Ouganda), a montré de grandes diversités de résultats en termes de compositions chimiques et d’activités biologiques.Propolis is a resinous substance collected by honeybees from various plant sources. Its secondary metabolites composition depends on the local flora around the collection site. During this study, the chemical characterization of a representative sample of a French propolis produced by ‘‘Ballot-Flurin Apiculteurs’’ led, through structural identifications involving HPLC/DAD/MS as well as 1D & 2D NMR, to the identification of 51 compounds, two of them being new. Phenolic acids and esters and flavonoids identified in this propolis indicate that it belongs to the so-called "poplar" type. The evaluation of the biological activities of different extracts or isolated compounds showed that this propolis, which exhibits a significant antioxidant activity (DPPH and ORAC) associated with a very interesting anti-glycation (anti-AGEs) potential, would represent a good candidate for the prevention of diseases involving AGEs such as diabetes. These extracts or compounds also exhibit antifungal and antibacterial activities towards two Candida yeasts on the one hand, and Staphylococcus aureus and its methicillin-resistant and susceptible strains on the other hand, the latter being nowadays responsible for many nosocomial infections. A study dealing with the inter-batch variability accompanied by an optimization of the industrial extraction process using experimental design were also carried out (Confidential part). Finally, the analysis of three propolis originating from Latin America (Mexico) and Africa (Ivory Coast and Uganda), revealed a great diversity of results in relation to chemical compositions and biological activities
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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