1,720,955 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
P-31 NMR-studies on the interaction of morpholinyl anthracyclines and related compounds with d(CGTACG)2. Thermodynamic and kinetic parameters
No full text31P NMR spectroscopy has been used to study the intercalation of the anthracyclines doxorubicin1, daunorubicin2, 4-demethoxydaunorubicin3, morpholinodoxorubicin4, methoxymorpholinodoxorubicin5 and 9-deoxydaunorubicin6 with the DNA fragment d(CGTACG)2. The individual phosphate resonances of the oligonucleotide were assigned in the free as well as in the intercalated species. The31P chemical shift variations allowed us to identify the intercalation sites, which resulted to be the same for all compoundsi.e. between the terminal CG base-pairs of the helix (two molecules of drugper duplex). The binding constants, the dissociation rate constants and ΔG # values have been determined in different conditions of ionic strength and temperature. The kinetic constant (k off) of the slow step of the anthracycline/duplex intercalation process has been directly measured by NOE exchange techniques. Binding constants depend on the ionic strength and on the self-association process so greatly, that their use to study by NMR anthracycline/DNA interactions is questionable. On the contrary, thek off are not affected by these phenomena and present an interesting trend for1–6, thus showing that the average lifetime of the drug in the intercalation site appears to be important for determining the cytotoxicity and the antimitotic activity
Assignment of phosphate groups and determination of P,H coupling constants in the DNA fragment d(CGTACG) by31P 2D NMR experiments
No full text2D 31P/1H correlation spectroscopy has been used to assign individual phosphates in the self-complementary DNA fragment d(CGTACG), which is present in solution as a B-DNA type double helix. 31P chemical shift variation with temperature and with the base sequence has been studied, and evidence is given of a steric clash between purines in the minor groove, affecting the chemical shift of the innermost TpA phosphate. For this hexanucleotide there is a good correlation of 31P shifts with both the helical twist (∑1) and roll angle (∑2) Calladine-Dickerson sum functions. Different types of linear correlations, also including data from other nuclotides, have been performed. The results show that it is more appropriate to consider the change in chemical shifts as it occurs during melting rather than the actual 31P shifts. An interesting correlation was also found between 31P chemical shifts and P,H-3′ coupling constants
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
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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