1,720,969 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
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
Biosynthesis of copper metalloenzymes in subterranean clover
No full textSubterranean clover (Trifolium subterraneum L. cv. Seaton Park) was grown in solution cultures containing adequate nitrogen both with and without copper. After copper deficiency had developed, Cu2+ was added to some deficient plants and copper content, protein content and activities of three copper met a 11oenzymes, (diamine oxidase DAO; [EC 1.4.3.63, ascorbate oxidase EEC 1.10.3.33 and .o-diphenol oxidase EEC 1.10.3.13), were assayed in young and recently matured leaf blades over 11 days during the development of the next three leaves.
Copper deficiency had little effect on protein concentrations but markedly depressed enzyme activities and copper concentrations in al 1 leaf blades assayed. Within four days of adding Cu 2 + to copper-deficient plants, copper concentrations of all the leaf blades increased to adequate values. Enzyme activities only increased to control levels in leaves which had not yet emerged at the time that Cu2+ was added.
The results suggested that active holoenzymes of DAO, ascorbate oxidase and .g-diphenol oxidase can only be synthesized in leaf blades during very early stages of their development.
DAO was purified 135-fold from leaves of subterranean clover and found to consist of three isoenzymes. The native enzyme had a molecular weight of about 150,000 and weights of 80,000. Clover DAO catalysed the oxidation of a wide range of amines and was inhibited by copper ligands and reagents consisted of two subunits both with molecular reactive towards carbonyl groups. Copper was essential for enzyme activity with the apoenzyme being reactivated specifically by copper. The enzyme had a broad pH optimum from pH 7 to 8 and an activation energy of 47 kJ/mol with putrescine as a substrate.
To study DAO biosynthesis further, antibodies were raised against the purified enzyme. The biosynthesis of diamine oxidase in leaf blades of subterranean clover was followed by labelling whole plants with 1 4 co2. A pulse-chase experiment in which DAO was immunoprecipitated with anti-DAO antibodies showed that only leaf primordia and the youngest emerged leaves were able to synthesize the enzyme.
The amount of DAO in young leaves of clover grown with a range of copper treatments was determined by its enzymatic activity and by single radial immunodiffusion against anti-DAO antibodies; both parameters were highly correlated with the copper concentration of the 1eaf. Further, anti-DAO antibodies reacted against apo-DAO prepared in vitro indicating that apo-DAO was absent from copper-deficient leaves. These results suggest that the biosynthesis of DAO in young clover leaves is controlled by the copper concentrations of the leaves.
Paly(A) mRNA, purified from leaf primordia and young emerging leaves of plants grown with either a high copper or low copper supply, was translated in wheat germ and rabbit reticulocyte cell-free systems. No differences between the two copper treatments could be seen in the SDS-PAGE profiles of the translation products after f1uorography. Since anti-DAO antibodies did not detect any DAO synthesized in vitro from either treatment no further conclusions could be drawn about the regulation of DAO biosynthesis by copper
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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