1,720,965 research outputs found
Theory and simulation of DNA charge transfer: From junctions to networks
No full textIn this work, we address charge transfer within complex arrangements of nucleobases from a theoretical and numerical point of view. We study dendrimers constructed from T-shaped double-stranded DNA three-way junctions (3WJs). The electronic structure of these junctions is computed on an atomistic level using a chemically specific Su-Schrieffer-Heeger Hamiltonian, which has been extended by a nonretarded reaction field to take solvent polarization effects into account. Hopping rates through isolated 3WJs are derived by analyzing the emerging potential energy surfaces using Marcus' theory of charge transfer. We find highly anisotropic transport; the corresponding rates are used to compute the global trapping kinetics on DNA dendrimers with a central absorbing core. As a potential application, we discuss a DNA-based drug delivery system
Dynamics Solved by the Three-Point Formula: Exact Analytical Results for Rings
No full textIn this paper, we study in the framework of the Gaussian model, the relaxation dynamics, and diffusion process on structures which show a ring-shape geometry. In order to extend the classical connectivity matrix to include interactions between more distant nearest neighbors, we treat the second derivative with respect to position by using the three-point formula. For this new Laplacian matrix, we determine analytical solutions to the eigenvalue problem. The relaxation dynamics is described by the mechanical relaxation moduli and for diffusion we focus on the behavior of the residual concentration at the initial node. Additionally, we investigate the scaling behaviors of the mean squared radius of gyration and of the smallest eigenvalue. To calculate the residual concentration, we consider that initially the whole material is concentrated only in one node and then it spreads over the ring. We compare our results with the ones obtained from the incremental ratio method. We observe that the results of the two methods for the considered quantities are slightly different. At any intermediate time/frequency domain, the results obtained by using the incremental ratio method underestimate the ones obtained by using the three-point formula. This finding can turn important for many applications in polymer systems or in other systems where diffusive motion occurs
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
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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