1,720,970 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
Synthèses de propargylamines et dérivés par catalyse au cuivre à l'aide de zéolithes modifiées
No full textLes propargylamines sont d'un grand intérêt synthétique et thérapeutique, avec diverses applications comme intermédiaires de synthèse et dans la conception de médicaments. Au cours des dernières années, la préparation du motif propargylamine via des stratégies à forte économie d’atomes et d’étapes a été rendue possible grâce au développement de diverses méthodes métallocatalysées. L'utilisation d'une zéolithe dopée au cuivre comme catalyseur hétérogène, ainsi que sa recyclabilité dans la synthèse de diverses propargylamines et de dérivés, ont été étudiées. Plusieurs procédures en cascade ont été développées dans des conditions sans solvant ou dans des solvants "verts", avec des stœchiométries de réactifs responsables et à des températures les plus douces possibles.Des propargylamines, dont des γ-amino-ynamides, ont été préparées via des réactions à trois com-posants et d'hydroamination. Des propargylamines α-tertiaires portant des amines secondaires ont été dérivées en 1,2-dihydropyridines spirocycliques. Ces dernières ont enfin été utilisées comme pré-curseurs d’isoquinuclidines et de pipéridines.Propargylamines are versatile compounds of great synthetic and therapeutic interest with diverse ap-plications as versatile synthetic intermediates and as lead structures in drug design. In recent years, several metal-catalysed methodologies have emerged for their atom- and step-economical prepara-tion. Aiming for improved sustainability, the use of a copper-exchanged zeolite as a heterogeneous catalyst, as well as its recyclability in the synthesis of diverse propargylamines and valuable deriva-tives, were investigated. Several atom- and step-economical catalytic procedures were developed under solvent-free conditions or based on “green” solvents, attractive reagent stoichiometries, and the mildest possible temperatures
Copper(I)-doped zeolites as green catalysts for organic synthesis
No full textLes motifs aryliques sont présents dans de nombreux composés biologiquement actifs. Nombre d’entre eux se retrouvent sous forme de biaryles, de phénols et de tétrahydroisoquinoléines, systèmes que l’on trouve dans de nombreux produits naturels et certains intermédiaires synthétiques importants. Au cours des dernières décennies, diverses réactions de couplage catalysées par des métaux (de transition) ont émergé pour synthétiser de tels motifs ou molécules en formant des liaisons carbone-carbone ou des liaisons carbone-hétéroatome. Cependant, la plupart de ces réactions ont été réalisée dans des conditions homogènes avec des conditions de réaction non satisfaisantes, telles que des températures élevées, des solvants toxiques et des bases et ligands supplémentaires. Afin de rendre ces conditions plus vertes et plus durables, le potentiel des zéolithes dopées au cuivre en tant que catalyseurs hétérogènes et recyclables a été évalué pour la synthèse de biaryles, de phénols et de dérivés de tétrahydroisoquinoléine au travers de plusieurs réactions de couplage, telles que les réactions de type homocouplage, les réactions de couplage croisé de type Chan-Lam-Evans et les réactions de couplage déhydrogénatif croisé. Plusieurs procédés catalytiques efficaces et économiques ont été développés dans des conditions plus vertes et plus douces, sans avoir besoin d’un ligand ni d’une base supplémentaire.De plus, l’application des motifs biaryles ainsi obtenus a également été explorée dans des réactions de Diels-Alder pour la construction d’hétérocycles d’intérêt avec des économies d’atomes élevées.Aryl rings are a predominant feature in numerous biologically active compounds. Most of them can exist as biaryl, phenol, and tetrahydroisoquinoline moieties, which are encountered in many natural products and in various important synthetic intermediates. In the last few decades, various (transition) metal-catalyzed coupling reactions have emerged to synthesize such motifs or molecules via the formation of carbon-carbon bonds or carbon-heteroatom bonds. However, most of them were performed under homogeneous conditions with unsatisfactory reaction conditions, such as high temperatures, toxic solvents, and additional bases and ligands. To improve the greenness and sustainability of these processes, the potential of copper-doped zeolites as heterogeneous and recyclable catalysts was evaluated for the synthesis of biaryls, phenols, and tetrahydroisoquinoline derivatives through the study of several coupling reactions, such as homocoupling-type reactions, Chan-Lam-Evans-type cross-coupling and cross-dehydrogenative coupling reactions. Several efficient and economical catalytic procedures were developed under greener and milder conditions without the need for any additional ligand and base.Furthermore, the application of the so-obtained important biaryl motifs has also been explored in Diels–Alder reactions for the construction of heterocycles of interest with high atom economies
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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