1,720,958 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
Pinces moléculaires commutables pour des organogels stimulables
No full textThis thesis presents the synthesis of a family of switchable molecular tweezers in order to control organogelation properties by exploiting their mechanical motion induced by a chemical stimulus. The molecular architecture of the system is based on a central switchable terpyridine unit that can, by complexation of a Zn2+ metal cation, change conformation from an 'open' to a 'closed' form. This molecular movement can then be reversed by adding tris(2-aminoethyl)amine, a competitive zinc(II) ligand. The gelation properties of the system are mainly due to the platinum(II)-salphen side units functionalized by alkyl chains. This work first focused on the study of the gelation properties of these complexes. Their self-assembly and aromatic solvent organogelation properties were studied at both macroscopic (DLS, rheology) and microscopic (SEM, cryo-ME, SAXS) scale in order to solve the structure of the assembly and the intermolecular interactions involved in it. The study then focused on optimizing the synthesis of the molecular tweezers using a double Sonogashira cross-coupling strategy. In their open form, the tweezers enabled gel formation in toluene or tetrachloroethane, which were fully characterized by multiple techniques. The switching properties of the tweezers were studied at the molecular scale under dilute conditions as well as at the material scale. The change in conformation of the tweezers induces a modification of the self-assembly properties of the system, resulting in a gel-sol transition at the macroscopic scale. The sol-gel transitions were achieved by successively adding complexation and decomplexation stimuli, then with temporal control using a chemical fuel in a multicomponent system. The last part of the work focused on possible optimizations of the system (changing the metal or the type of functionalization) in order to explore new types of solvents.Cette thèse présente la synthèse d'une famille de pinces moléculaires commutables en vue de contrôler des propriétés d'organogélation en exploitant leur mouvement mécanique induit par un stimulus chimique. L'architecture moléculaire du système est basée sur une unité commutable centrale terpyridine qui peut, par complexation d'un cation métallique Zn2+, changer de conformation d'une forme « ouverte » vers une forme « fermée ». Ce mouvement moléculaire peut alors être inversé par ajout de tris(2-aminoethyl)amine, un ligand compétitif du zinc(II). Les propriétés de gélation du système proviennent principalement des unités latérales platine(II)-salphen fonctionnalisées par des chaines alkyles. Ce travail s'est tout d'abord concentré sur l'étude des propriétés de gélation de ces complexes. Leurs propriétés d'autoassemblage et d'organogélation de solvants aromatiques ont été étudiée à l'échelle macroscopique (DLS, rhéologie) et microscopique (MEB, cryo-ME, SAXS) afin d'élucider la structure de l'assemblage et les interactions intermoléculaire impliquées. La suite de l'étude s'est portée sur l'optimisation de la synthèse des pinces moléculaires par une stratégie de double couplage de Sonogashira. Dans leur forme ouverte, les pinces ont permis la formation de gel dans le toluène ou le tétrachloréthane qui ont été entièrement caractérisés par de multiples techniques. Les propriétés de commutation des pinces ont été étudiées à l'échelle moléculaires en conditions diluées puis à l'échelle du matériau. Le changement de conformation de la pince induit une modification des propriétés d'autoassemblage du système, ce qui se traduit par une transition gel-sol à l'échelle macroscopique. Les transitions sol-gel ont pu être réalisées par ajouts successifs des stimuli de complexation et de décomplexation, puis avec un contrôle temporel en faisant usage d'un carburant chimique dans un système multicomposants. La dernière partie du travail s'est concentrée sur les optimisations possibles du système (changement du métal ou du type de fonctionnalisation) afin d'explorer de nouveaux types de solvants
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Switchable molecular tweezers for stimuli responsive organogels
No full textCette thèse présente la synthèse d'une famille de pinces moléculaires commutables en vue de contrôler des propriétés d'organogélation en exploitant leur mouvement mécanique induit par un stimulus chimique. L'architecture moléculaire du système est basée sur une unité commutable centrale terpyridine qui peut, par complexation d'un cation métallique Zn2+, changer de conformation d'une forme « ouverte » vers une forme « fermée ». Ce mouvement moléculaire peut alors être inversé par ajout de tris(2-aminoethyl)amine, un ligand compétitif du zinc(II). Les propriétés de gélation du système proviennent principalement des unités latérales platine(II)-salphen fonctionnalisées par des chaines alkyles. Ce travail s'est tout d'abord concentré sur l'étude des propriétés de gélation de ces complexes. Leurs propriétés d'autoassemblage et d'organogélation de solvants aromatiques ont été étudiée à l'échelle macroscopique (DLS, rhéologie) et microscopique (MEB, cryo-ME, SAXS) afin d'élucider la structure de l'assemblage et les interactions intermoléculaire impliquées. La suite de l'étude s'est portée sur l'optimisation de la synthèse des pinces moléculaires par une stratégie de double couplage de Sonogashira. Dans leur forme ouverte, les pinces ont permis la formation de gel dans le toluène ou le tétrachloréthane qui ont été entièrement caractérisés par de multiples techniques. Les propriétés de commutation des pinces ont été étudiées à l'échelle moléculaires en conditions diluées puis à l'échelle du matériau. Le changement de conformation de la pince induit une modification des propriétés d'autoassemblage du système, ce qui se traduit par une transition gel-sol à l'échelle macroscopique. Les transitions sol-gel ont pu être réalisées par ajouts successifs des stimuli de complexation et de décomplexation, puis avec un contrôle temporel en faisant usage d'un carburant chimique dans un système multicomposants. La dernière partie du travail s'est concentrée sur les optimisations possibles du système (changement du métal ou du type de fonctionnalisation) afin d'explorer de nouveaux types de solvants.This thesis presents the synthesis of a family of switchable molecular tweezers in order to control organogelation properties by exploiting their mechanical motion induced by a chemical stimulus. The molecular architecture of the system is based on a central switchable terpyridine unit that can, by complexation of a Zn2+ metal cation, change conformation from an 'open' to a 'closed' form. This molecular movement can then be reversed by adding tris(2-aminoethyl)amine, a competitive zinc(II) ligand. The gelation properties of the system are mainly due to the platinum(II)-salphen side units functionalized by alkyl chains. This work first focused on the study of the gelation properties of these complexes. Their self-assembly and aromatic solvent organogelation properties were studied at both macroscopic (DLS, rheology) and microscopic (SEM, cryo-ME, SAXS) scale in order to solve the structure of the assembly and the intermolecular interactions involved in it. The study then focused on optimizing the synthesis of the molecular tweezers using a double Sonogashira cross-coupling strategy. In their open form, the tweezers enabled gel formation in toluene or tetrachloroethane, which were fully characterized by multiple techniques. The switching properties of the tweezers were studied at the molecular scale under dilute conditions as well as at the material scale. The change in conformation of the tweezers induces a modification of the self-assembly properties of the system, resulting in a gel-sol transition at the macroscopic scale. The sol-gel transitions were achieved by successively adding complexation and decomplexation stimuli, then with temporal control using a chemical fuel in a multicomponent system. The last part of the work focused on possible optimizations of the system (changing the metal or the type of functionalization) in order to explore new types of solvents
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