1,720,954 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
Silylformylation as a central tool for the synthesis of complex silaheterocycles
No full textBien que le silicium soit le second élément le plus abondant de la croûte terrestre, il n’est que très peu présent chez l’Homme et est absent des molécules biologiques organiques de la vie. Les propriétés physico-chimiques (électropositivité, taille, lipophilie etc…) de cet atome ainsi que le fait qu’il soit dans la même colonne que le carbone en font pourtant un bioisostère potentiel particulièrement intéressant. Dans ce contexte, de nombreux groupes se sont intéressés à la substitution d’atomes de carbone par un atome de silicium, concept nommé le « carbon-silicon switch ». Parmi les sila-analogues étudiés, certains d’entre eux sont obtenus par inclusion d’un atome de silicium dans un cycle (les silacycles). Néanmoins, contrairement à leurs équivalents carbonés, il n’existe que peu de méthodologies générales permettant l’accès à de tels composés. Ainsi, nos travaux ont alors porté sur la synthèse de silacycles en deux étapes. La première étape est basée sur une réaction de silylformylation d’alcynes introduisant un silane aromatique et un aldéhyde de part et d’autre d’une double liaison C=C. La seconde étape repose sur une cyclisation de type Friedel-Crafts fournissant une nouvelle famille d’hétérocycles silylés dont les propriétés photophysiques ont pu être étudiées. Dans un second temps, une méthode d’annélation d’ynamides conduisant à des amido-indénones a également été mise au point.Although silicon is the second most abundant element in the earth's crust, it is only slightly present in human beings and absent from the organic biological molecules. The physico-chemical properties (electropositivity, size, lipophilicity etc...) of this atom and its presence in the same column as carbon makes it an interesting potential bioisostere. In this context, many research groups have been interested in the substitution of carbon atoms by a silicon atom ("carbon-silicon switch"). Among the sila-analogues studied, some of them are obtained by the inclusion of a silicon atom in a ring (silacycles). Nevertheless, there is a real lack of general methodologies to access such compounds. Thus, we aimed to develop a two-step synthesis of silicon containing heterocycles starting from alkyne derivatives. The first step is based on a silylformylation reaction of alkynes introducing an aromatic silane and an aldehyde on both sides of a C=C double bond. The second step is based on a Friedel-Crafts type cyclization providing a new family of silaheterocycles. The photophysical properties of these compounds were also investigated. In addition, an annulation reaction of ynamides was developed leading to amido-indenones
Silylformylation d'alcynes fonctionnalisés appliquée à la synthèse de silahétérocycles complexes
No full textAlthough silicon is the second most abundant element in the earth's crust, it is only slightly present in human beings and absent from the organic biological molecules. The physico-chemical properties (electropositivity, size, lipophilicity etc...) of this atom and its presence in the same column as carbon makes it an interesting potential bioisostere. In this context, many research groups have been interested in the substitution of carbon atoms by a silicon atom ("carbon-silicon switch"). Among the sila-analogues studied, some of them are obtained by the inclusion of a silicon atom in a ring (silacycles). Nevertheless, there is a real lack of general methodologies to access such compounds. Thus, we aimed to develop a two-step synthesis of silicon containing heterocycles starting from alkyne derivatives. The first step is based on a silylformylation reaction of alkynes introducing an aromatic silane and an aldehyde on both sides of a C=C double bond. The second step is based on a Friedel-Crafts type cyclization providing a new family of silaheterocycles. The photophysical properties of these compounds were also investigated. In addition, an annulation reaction of ynamides was developed leading to amido-indenones.Bien que le silicium soit le second élément le plus abondant de la croûte terrestre, il n’est que très peu présent chez l’Homme et est absent des molécules biologiques organiques de la vie. Les propriétés physico-chimiques (électropositivité, taille, lipophilie etc…) de cet atome ainsi que le fait qu’il soit dans la même colonne que le carbone en font pourtant un bioisostère potentiel particulièrement intéressant. Dans ce contexte, de nombreux groupes se sont intéressés à la substitution d’atomes de carbone par un atome de silicium, concept nommé le « carbon-silicon switch ». Parmi les sila-analogues étudiés, certains d’entre eux sont obtenus par inclusion d’un atome de silicium dans un cycle (les silacycles). Néanmoins, contrairement à leurs équivalents carbonés, il n’existe que peu de méthodologies générales permettant l’accès à de tels composés. Ainsi, nos travaux ont alors porté sur la synthèse de silacycles en deux étapes. La première étape est basée sur une réaction de silylformylation d’alcynes introduisant un silane aromatique et un aldéhyde de part et d’autre d’une double liaison C=C. La seconde étape repose sur une cyclisation de type Friedel-Crafts fournissant une nouvelle famille d’hétérocycles silylés dont les propriétés photophysiques ont pu être étudiées. Dans un second temps, une méthode d’annélation d’ynamides conduisant à des amido-indénones a également été mise au point
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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