1,720,959 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
Antimicrobial surfaces based on self-assembled nanoreactors : from block copolymer synthesis to bacterial adhesion study
Get PDFThe aim of this work is to develop a new strategy for the prevention of biofilm growth. For this purpose, we prepared bioactive surfaces resulting from the surface-immobilization of nanoreactors self-assembled from amphiphilic poly(isobutylene)-block-oligonucleotide copolymers. The block copolymer was synthesized and characterized via appropriate complementary techniques. Self-assembly into vesicles allowed the functional encapsulation of enzymes, as assayed through enzyme activity monitoring, leading to a prodrug-drug system. The self-assembled structures were specifically immobilized on surfaces via base pairing between the oligonucleotide block of the copolymer and the surface tethered complementary nucleotide sequence.
Using E.coli strains, we first observed an influence of the two density of oligonucleotides immobilized on the surface on the number of adherent bacteria. This influence may be due to an effect of surface charge density. We then confirmed the well-known role of curli in biofilm cohesion, and we showed gene over-expression associated with curli production on oligonucleotide-modified surfaces. We demonstrated that gene over-expression does not depend on the topographical features of the surface or on the composition of the nucleotide sequences used in this study. Finally, we demonstrated that the presence of the vesicular structure is able to produce strong anti-adhesive properties of the surface. We assume, from observations of bacterial response in dynamic conditions, that this effect is due to increased bacterial motility on the surface, leading to a high detachment rate. Which is further confirms by a comparable bacterial response observed on agar hydrogel of different hardnesses. This result provides a preliminary outcome, paving the way to new approaches to antimicrobial strategies
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
Surfaces antimicrobiennes basées sur l'auto-assemblage de nanoréacteurs : de la synthèse du copolymère à l'étude de l'adhésion bactérienne
No full textThe aim of this work is to develop a new strategy for the prevention of biofilm growth. For this purpose, we prepared bioactive surfaces resulting from the surface-immobilization of nanoreactors self-assembled from amphiphilic poly(isobutylene)-block-oligonucleotide copolymers. The block copolymer was synthesized and characterized via appropriate complementary techniques. Self-assembly into vesicles allowed the functional encapsulation of enzymes, as assayed through enzyme activity monitoring, leading to a prodrug-drug system. The self-assembled structures were specifically immobilized on surfaces via base pairing between the oligonucleotide block of the copolymer and the surface tethered complementary nucleotide sequence. Using E.coli strains, we first observed an influence of the two density of oligonucleotides immobilized on the surface on the number of adherent bacteria. This influence may be due to an effect of surface charge density. We then confirmed the well-known role of curli in biofilm cohesion, and we showed gene over-expression associated with curli production on oligonucleotide-modified surfaces. We demonstrated that gene over-expression does not depend on the topographical features of the surface or on the composition of the nucleotide sequences used in this study. Finally, we demonstrated tha the presence of the vesicular structure is able to produce strong anti-adhesive properties of the surface. We assume, from observations of bacterial response in dynamic conditions, that this effect is due to increased bacterial motility on the surface, leading to a high detachment rate. Which is further confirms by a comparable bacterial response observed on agar hydrogel of different hardnesses. This result provides a preliminary outcome, paving the way to new approaches to antimicrobial strategies.Ce travail a pour but le développement d'une nouvelle classe de surfaces destinée à la lutte contre la formation de biofilms. Ces surfaces se basent sur l'immobilisation de nanoréacteurs, résultant de l'auto-assemblage d'un copolymère amphiphile poly(isobutylène)-bloc-oligonucléotide sous forme de vésicules encapsulant une enzyme. Le rôle de cette enzyme est de produire des agents antimicrobiens à partir de précurseurs inactifs. Le copolymère a été synthétisé et caractérisé par des techniques complémentaires et le maintien de l'activité enzymatique a été démontré. Les surfaces bioactives sont finalement obtenues par l'immobilisation des nanoréacteurs grâce aux capacités d'hybridation des séquences nucléiques complémentaires. Nous avons d'abord montré l'influence des deux densités d'oligonucléotides utilisées sur le nombre d'E.coli adhérentes, due probablement aux variations de charges surfaciques associées. Nous avons ensuite confirmé l'influence des curli sur la cohésion des biofilms et mis en évidence une surexpression de la production de curli en présence d'oligonucléotides sur les surfaces, et ce, indépendamment de la séquence et de la topographie considérées. Finalement, nous avons observé un effet antiadhésif lié aux structures vésiculaires indépendant de la topographie de la surface. L'étude complémentaire, menée en mode de culture dynamique, a conduit à envisager que les propriétés mécaniques de la surface affectent la rétention des bactéries en modifiant leur mobilité sur la surface. L'analogie avec des résultats obtenus sur des hydrogels d'agar de différentes duretés conforte cette hypothèse. Ces résultats posent les fondements permettant d'envisager de nouvelles stratégies dans la lutte contre la formation des biofilms
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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