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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
Nouvelles stratégies synthétiques vers la formation d'hétérodinucléotides incorporant un motif difluorophosphinothioate.
No full textOligonucleotides (ONs) represent a major class of bioactive molecules with a great potential in medicinal chemistry. However, the development of therapeutic ONs is facing two major problems: a lack of stability toward nucleases and a lack of selectivity toward a specific therapeutic target. To overcome those problems, academic and industrial chemists are working on the development of modified ONs, incorporating in particular new analogues of the natural phosphodiester bridge. In this context, the synthesis of new analogues was studied in the laboratory, namely the difluorophosphinate (R-CF2-P(O)(OEt)CH2-R) and difluorophosphinothioate (R-CF2-P(S)(OEt)CH2-R) units. Thanks to previous studies, a first-generation synthesis was developed towards a homodinucleotide incorporating a difluorophosphinate moiety. A key fragment furanose-CF2-P(S)(OEt)CH2-furanose, allowing the introduction of two identical nucleic bases, was obtained by the sequential construction of the two P-C bonds. Oxidation of R-CF2-P(S)(OEt)CH2-R gave access to the R-CF2-P(O)(OEt)CH2-R unit. This thesis describes the development of a second-generation synthesis towards heterodinucleotides incorporating a difluorophosphin(othio)ate as internucleosidic bridge and two different nucleic bases. Starting from a common substrate, allofuranose, the synthesis of key fragments was worked out. These intermediates were used to build a difluorophosphinothioate internucleosidic bridge. Thus, a new key fragment furanose-CF2-P(S)(OEt)CH2-nucleoside was obtained and used to introduce a second, identical or different, nucleic base. However, a substitution process involving the replacement of a nucleic base with another one was highlighted. Despite this trans-N-glycosylation process, six dinucleotides (T-PMB-U, T-U, U-U, T-T, C-T, C-G-Prot) were prepared.Les oligonucléotides (ONs) naturels sont une classe majeure de biomolécules ayant un potentiel thérapeutique prometteur. Cependant, le développement d’ONs thérapeutiques rencontre deux problèmes majeurs : un manque de stabilité envers les nucléases et un manque de sélectivité envers une cible thérapeutique. Pour pallier ces problèmes, les chercheurs académiques et industriels ont travaillé sur le développement d’ONs modifiés, incorporant notamment de nouveaux analogues du pont phosphodiester naturel. Dans ce contexte, la synthèse de nouveaux analogues du lien naturel a été étudiée au laboratoire, à savoir les motifs difluorophosphinate (R-CF2-P(O)(OEt)CH2-R) et difluorophosphinothioate (R-CF2-P(S)(OEt)CH2-R). Ainsi, grâce aux travaux menés précédemment, une synthèse de première génération a été mise au point conduisant à la formation d’un homodinucléotide comportant ces motifs. Le fragment-clé furanose-CF2-P(S)(OEt)CH2-furanose, permettant l’introduction de deux bases nucléiques identique, est obtenu par une construction successive des deux liaisons P-C. Une oxydation du motif R-CF2-P(S)(OEt)CH2-R permet l’obtention du lien R-CF2-P(O)(OEt)CH2-R. Dans la continuité de ces travaux, ce projet de thèse est focalisé sur la mise au point d’une synthèse de seconde génération menant à des hétérodinucléotides caractérisés par la présence du motif difluorophosphin(othio)ate et deux nucléobases différentes. A partir d’un substrat commun, l’allofuranose, la synthèse des différents nucléosides intermédiaires a été réalisée. Dans un premier temps, ceux-ci ont ensuite été utilisés afin de former un nouveau fragment-clé furanose-CF2-P(S)(OEt)CH2-nucléoside à partir duquel une seconde base nucléique différente a été incorporée. Cependant, au cours de cette étude, un phénomène de substitution d’une base nucléique par une autre a pu être mis en évidence. En dépit de ce processus dit de trans-N-glycosylation, six dinucléotides (T-PMB-U, T-U, U-U, T-T, C-T, C-G-Prot) ont pu être préparés
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
New synthetic pathways for the formation of heterodinucleotides incorporing difluorophosphinothioate linkage
No full textLes oligonucléotides (ONs) naturels sont une classe majeure de biomolécules ayant un potentiel thérapeutique prometteur. Cependant, le développement d’ONs thérapeutiques rencontre deux problèmes majeurs : un manque de stabilité envers les nucléases et un manque de sélectivité envers une cible thérapeutique. Pour pallier ces problèmes, les chercheurs académiques et industriels ont travaillé sur le développement d’ONs modifiés, incorporant notamment de nouveaux analogues du pont phosphodiester naturel. Dans ce contexte, la synthèse de nouveaux analogues du lien naturel a été étudiée au laboratoire, à savoir les motifs difluorophosphinate (R-CF2-P(O)(OEt)CH2-R) et difluorophosphinothioate (R-CF2-P(S)(OEt)CH2-R). Ainsi, grâce aux travaux menés précédemment, une synthèse de première génération a été mise au point conduisant à la formation d’un homodinucléotide comportant ces motifs. Le fragment-clé furanose-CF2-P(S)(OEt)CH2-furanose, permettant l’introduction de deux bases nucléiques identique, est obtenu par une construction successive des deux liaisons P-C. Une oxydation du motif R-CF2-P(S)(OEt)CH2-R permet l’obtention du lien R-CF2-P(O)(OEt)CH2-R. Dans la continuité de ces travaux, ce projet de thèse est focalisé sur la mise au point d’une synthèse de seconde génération menant à des hétérodinucléotides caractérisés par la présence du motif difluorophosphin(othio)ate et deux nucléobases différentes. A partir d’un substrat commun, l’allofuranose, la synthèse des différents nucléosides intermédiaires a été réalisée. Dans un premier temps, ceux-ci ont ensuite été utilisés afin de former un nouveau fragment-clé furanose-CF2-P(S)(OEt)CH2-nucléoside à partir duquel une seconde base nucléique différente a été incorporée. Cependant, au cours de cette étude, un phénomène de substitution d’une base nucléique par une autre a pu être mis en évidence. En dépit de ce processus dit de trans-N-glycosylation, six dinucléotides (T-PMB-U, T-U, U-U, T-T, C-T, C-G-Prot) ont pu être préparés.Oligonucleotides (ONs) represent a major class of bioactive molecules with a great potential in medicinal chemistry. However, the development of therapeutic ONs is facing two major problems: a lack of stability toward nucleases and a lack of selectivity toward a specific therapeutic target. To overcome those problems, academic and industrial chemists are working on the development of modified ONs, incorporating in particular new analogues of the natural phosphodiester bridge. In this context, the synthesis of new analogues was studied in the laboratory, namely the difluorophosphinate (R-CF2-P(O)(OEt)CH2-R) and difluorophosphinothioate (R-CF2-P(S)(OEt)CH2-R) units. Thanks to previous studies, a first-generation synthesis was developed towards a homodinucleotide incorporating a difluorophosphinate moiety. A key fragment furanose-CF2-P(S)(OEt)CH2-furanose, allowing the introduction of two identical nucleic bases, was obtained by the sequential construction of the two P-C bonds. Oxidation of R-CF2-P(S)(OEt)CH2-R gave access to the R-CF2-P(O)(OEt)CH2-R unit. This thesis describes the development of a second-generation synthesis towards heterodinucleotides incorporating a difluorophosphin(othio)ate as internucleosidic bridge and two different nucleic bases. Starting from a common substrate, allofuranose, the synthesis of key fragments was worked out. These intermediates were used to build a difluorophosphinothioate internucleosidic bridge. Thus, a new key fragment furanose-CF2-P(S)(OEt)CH2-nucleoside was obtained and used to introduce a second, identical or different, nucleic base. However, a substitution process involving the replacement of a nucleic base with another one was highlighted. Despite this trans-N-glycosylation process, six dinucleotides (T-PMB-U, T-U, U-U, T-T, C-T, C-G-Prot) were prepared
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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