1,721,120 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
Novel approaches for the creation of artificial metalloenzymes
Get PDFArtificial metalloenzymes can be defined as the fusion of chemo- and enzymatic catalysts by insertion of non-specific achiral catalytic moieties into the chiral environment of a protein cavity, thereby broadening the scope of both fields. Presently, the field of artificial metalloenzymes is at an exciting stage, with interesting features already demonstrated and a growing reaction repertoire, but has not yet reached maturity. To exploit the full potential of catalytic reactions using hybrid catalysts is far from trivial and as the ability to screen for novel properties remains limited. Albeit computational simulations are advanced, directed/designed evolution of such selective catalysts remains challenging, hence their development relies to a great extent on trial-and-error. Hitherto, screening and evaluation of ligands for activity or of proteins for selectivity still remains an elaborate process, as all library members have to be evaluated individually. High-throughput analysis to simultaneously evaluate large hybrid catalyst libraries within a short time-frame has therefore become increasingly important.
The key focuses of this research were the development of (i) novel purification strategies to simplify the challenge of producing functional protein (streptavidin), in sufficient quantity and appropriate purity for high-throughput screening of organometallic moieties; (ii) a reiterative approach to protein expression: re-design of streptavidin construct, moving to a more complex expression system, Pichia pastoris, to increase the production of streptavidin and simplify the purification process; and (iii) a novel biomolecular scaffold, human carbonic anhydrase II, for the creation of a new artificial metalloenzyme.
This thesis addresses the issues and feasibility of purification and expression processes and, highlights bottlenecks that arose using these technologies, key learning's and where to go from now
Cloning, expression, characterisation and mutational analysis of L-aspartate oxidase from Pseudomonas putida
No full textL-Amino acid oxidases (LAAOs) are useful catalysts for the deracemisation of racemic amino acid substrates when combined with abiotic reductants. The gene nadB encoding the L-aspartate amino acid oxidase from Pseudomonas putida (PpLASPO) has been cloned and expressed in E. coli. The purified PpLASPO enzyme displayed a K-M for L-aspartic acid of 2.26 mM and a k(cat) = 10.6 s(-1), with lower activity also displayed towards L-asparagine, for which pronounced substrate inhibition was also observed. The pH optimum of the enzyme was recorded at pH 7.4. The enzyme was stable for 60 min at up to 40 degrees C, but rapid losses in activity were observed at 50 degrees C. A mutational analysis of the enzyme, based on its sequence homology with the LASPO from E. coli of known structure, appeared to confirm roles in substrate binding or catalysis for residues His244. His351, Arg386 and Arg290 and also for Thr259 and Gln242. The high activity of the enzyme, and its promiscuous acceptance of both L-asparagine and L-glutamate as substrates, if with low activity, suggests that PpLASPO may provide a good model enzyme for evolution studies towards AAOs of altered or improved properties in the future. (C) 2012 Elsevier B.V. All rights reserved
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
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