1,721,034 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
Understanding and simulating mechanochromism in dye-dispersed polymer blends: from atomistic insights to macroscopic properties
No full textIn this work, we propose a computational protocol enabling the simulation of mechanochromic responses in dye-dispersed polymer blends. The main objective is the modeling of the molecular-level structural changes responsible for the modulation of the photophysical properties that lead to the mechanochromic phenomenon. In this demonstrative study, we focus on predicting the changes in optical absorption displayed by a model system consisting of a dimer of a tetraphenylethylene derivative dispersed in a polyethylene matrix. The blend is subjected to an external stimulus that causes a modulation of the polymer matrix density that translates, in turn, into the emergence of specific mechanical constraints on the optically active dimers. The accurate description of this phenomenon requires the reliable sampling of the dimer configurations induced by the interaction with the matrix under stress. These molecular geometries are associated with modified electronic structures that confer novel absorption responses to the dispersed dyes.MethodsIn the present contribution, the sampling of these structures is achieved through classical molecular dynamics (MD) simulations including a model element to apply an anisotropic mechanical force. This element allows the microscopic modeling of the chains' and dyes' structural rearrangements under stress. After the sampling, we compare the results of two approaches for the prediction of the optical response: (i) the calculation of a mean response from a statistical average over quantum chemical calculations on the sampled MD structures and (ii) a prediction via a more expensive hybrid scheme allowing the relaxation of the sampled molecular geometries in the presence of the matrix constraints
The genome of Drosophila subpulchrella and the importance of sister-species comparison in agricultural pest science
Get PDFGenomics is often used to clarify the biology of agricultural pests and to define management strategies against them. There is however one crucial aspect often neglected: the comparison between a pest and its closest non-pest sister species. In the absence of a sister species, genome comparisons cannot discriminate characters that are unique to the pest, from those shared with other members of its clade. To highlight the benefit of a sister species comparison, we sequenced a draft genome of D. subuplchrella, the closest known non-pest sister species of model fruit pest D. suzukii. First, our evolutionary analyses could set the age of speciation of D. suzukii, clarified its paleo-ecological context, and revealed genetic admixtures that should be taken into account when modeling pest population in the field. Second, and probably more importantly, we could polarize various genomic event on the phylogenetic tree, revealing a set of key chemosensory genes that will ease the development of trapping strategies based on lures. Finally, we could disentangle the evolutionary significance of Wolbachia symbionts which may serve as bio-control agents. Our results show that applying a sister species concept to applied research agenda can enhance and speed up the definition of new management strategie
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