1,720,974 research outputs found

    An exploratory conformational analysis of 3-mercapto-propanamide and 2-methyl-3-mercapto-propanamide as well as their S-deprotonated conjugate basis: An ab initio study

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    Ab initio conformational analysis has been carried out on 3-mercapto-propanamide, (R)- and (S)-2-methyl-3-mercaptopropanamide as well as their S-deprotonated conjugate basis. They were carried out at the HF/3-21G level of theory. The topology of the conformational potential energy surfaces and hypersurfaces have been analysed.Fil: Torday, László L.. Albert Szent-Györgyi Medical University; HungríaFil: Penke, Botond. Albert Szent-Györgyi Medical University; HungríaFil: Zamarbide, Graciela Nidia. Universidad Nacional de San Luis; ArgentinaFil: Enriz, Ricardo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Papp, Julius Gy. Albert Szent-Györgyi Medical University; Hungrí

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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

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    We 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

    Author Index

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    How reliable could economic Hartree-Fock computations be in studying large, folded peptides? A comparative HF and DFT case study on N- and C-protected aspartic acid

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    In this study, potential energy hypersurfaces have been generated and analyzed for each of the nine possible backbone (BB) conformations for both the endo and exo forms of N-acetyl-L-aspartic acid N′-methylamide. Ab initio calculations were carried out at RHF/3-21G, RHF/6-31G(d), and B3LYP/6-31G(d) levels for all backbone conformations. The relative energies, as well as stabilization energies exerted by the sidechain (SC) on the backbone, were calculated for all stable conformers. All sidechain-sidechain (HO···O=C), backbone-backbone (N-H⋯O=C), and sidechain-backbone (N-H···O=C; N-H···OH) hydrogen bond interactions were analyzed. The appearance of the traditionally absent αL and εL conformers may be recognized as special geometric orientation which the aspartyl residue manifests during peptide folding or ligand docking in a receptor that contains aspartic acids in its ligand recognition sites. At all three levels of theory, there exists a trend between the hydrogen bond distance and ring size. In addition, strikingly high correlations between the torsional angles (R2 = 0.9937 for RHF/6-31G(d) versus RHF/3-21G; R2 = 0.9967 for B3LYP/6-31G(d) versus RHF/6-31G(d); R2 = 0.9914 for B3LYP/6-31G(d) versus RHF/3-21G) and between the ΔE values in kcal/mol (R2 = 0.9424 for RHF/6-31G(d) versus RHF/3-21G; R2 = 0.9108 for B3LYP/6-31G(d) versus RHF/6-31G(d); R2 = 0.9434 B3LYP/6-31G(d) versus RHF/3-21G) found at the different ab initio levels suggest that calculations carried out at the lower levels (i.e. at RHF/3-21G) are still significant.Fil: Koo, Joseph C.P.. University of Toronto; CanadáFil: Lam, Janice S.W.. University of Toronto; CanadáFil: Salpietro, Salvatore J.. University of Toronto; CanadáFil: Chass, Gregory A.. University of Toronto; Canadá. Velocet R And D; CanadáFil: Enriz, Ricardo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Química; ArgentinaFil: Torday, Ladislaus L.. Szegedi Tudományegyetem; HungríaFil: Varro, Andras. Szegedi Tudományegyetem; HungríaFil: Papp, Julius Gy.. Szegedi Tudományegyetem; Hungrí

    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We 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
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