1,720,957 research outputs found
Homology building, protein-protein docking and MD approach to the simulation of the quaternary complex E1/E2/Ub2
No full textUbiquitylation is essential to numerous cellular and developmental processes. Alterations in this process are observed in most cancer cells. Ubiquitylation is catalysed by the sequential action of ubiquitin-activating enzyme (UbA1; E1), a ubiquitin-conjugating enzyme (UbC; E2) and a ubiquitin protein ligase (E3). Despite the central role of the E1 enzyme in the Ub conjugation cascade, and its potential as drug target, information regarding the mechanism of UbA1 ubiquitylation or of the Ub transfer from UbA1 to the E2, are limited to mutational studies,[1] and the mechanistic details of ubiquitin thioester bond formation and transfer to substrate are still undetermined. In this context, we have simulated in silico the entire process leading to the UbA1-UbC interaction, by means of a computational approach including many techniques such as homology building, protein-protein docking and molecular dynamics. In particular here we describe static models of hUbA1, as well as of its intermediate complexes involved in the activation and in the formation of transient thiolester complex: i) hUbA1 in complex with adenylated ubiquitin, ii) the covalent adduct between Ub and hUbA1, iii) the hUbA1 in complex with adenylated ubiquitin and covalently linked to the ubiquitin and, finally iv) the quaternary complex including hUbA1 two ubiquitin molecules and a member of the UBC family of enzymes.
In this proposal, we intend to study the conformational behaviour of these four model by using a computational approach characterized by an increased level of accuracy in the study of the system. To the best of our knowledge, this is the first structural information on the hUbA1/E2 complex, and therefore could disclose important information on the mechanism of this important enzyme and will pave the way to the rational design of ubiquitylation inhibitors
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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