1,720,996 research outputs found
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
Spectroscopically Labeled Peptaibiotics. Synthesis and Properties of Selected Trichogin GA IV Analogs Bearing a Side-Chain-Monofluorinated Aromatic Amino Acid for19F-NMR Analysis
No full textWe prepared by solid-phase methods, chromatographically purified, and characterized three analogs of the ten-amino acid-residue, membrane-active, lipopeptaibiotic trichogin GA IV, each containing a single (4-fluorophenyl)alanine in position 3, 7, or 10, where it replaces the hydrophobic residue Leu3, Leu7, or Ile10, respectively. We incorporated the fluorine probe based on the observation that the 19F-NMR technique has been extensively utilized to analyze peptidemembrane interactions in biological systems. A detailed conformational investigation in solution, including a membrane-mimetic environment, was performed on these compounds using FT-IR absorption, CD, and 2D-NMR, combined with molecular-dynamics calculations. The experimentally observed, mixed 310/-helical structures unequivocally show that the principal conformational features of trichogin GA IV are preserved in all three analogs. Analogies and differences between the behavior of the natural lipopeptaibiotic and those of the peptides characterized by the side-chain monofluorinated aromatic amino acid were found in membrane-permeabilization experiments and antimicrobial assays. The results of a preliminary solution 19F-NMR study support the view that the 19F label is an excellent reporter for changes in the helical environment of the peptid
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
Spectroscopically labeled peptaibiotic analogs: the 4-nitrophenylalanine infrared absorption probe inserted at different positions into trichogin GA IV
No full textA set of three analogs of the 10-residue, membrane-active lipopeptaibiotic trichogin GA IV, labeled with the promising
4-nitrophenylalanine IR absorption probe for local polarity, was synthesized by the solid-phase methodology, chromatographically
purified, and extensively characterized. A single residue modification was inserted near the N-terminus, in
the central region, or at the C-terminus. A solution conformational analysis, carried out by FT-IR absorption, CD, and
2D-NMR combined with molecular dynamics calculations, indicates that the mono-labeled analogs maintain the overall
helical properties of the parent compound. Membrane permeabilization measurements and antimicrobial tests revealed
that they possess membrane-modifying properties and in vitro antibacterial activities analogous to those of the natural
lipopeptaibiotic. Our IR absorption and attenuated total reflectance investigations in various environments, from which
water was excluded for solubility reasons, showed that the 1350 cm1 4-nitrobenzyl band is a reporter group of rather
limited sensitivity
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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