1,721,113 research outputs found
Studies of archaemycin biosynthesis
No full textThe biosynthesis of archaemycin S541 factor A in a culture of Streptomyces thermoarchaencis (RS1), has been studied using 13C, 14C, 18O, 2H and 3H labeled precursors. The 13C NMR spectrum of S541 factor-A has been assigned. Incorporation of [1-13C]acetate resulted in a major enrichment of carbons 1, 5, 9, 15, 17, 19 and 21, and a minor enrichment of carbons 3, 7, 11, 13, 23 and 25. With [1-13C]propionate, enrichment of carbons 3, 7, 11, 13, 23, and 25 was observed. Feeding [3-13C]propionate, produced enrichment of carbons 4a, 8a, 12a, 14a, 24a and 26a respectively. This established that the carbon skeleton of S541 factor-A, is derived from a head to tail condensation of seven acetate and six propionate units. Studies elsewhere using 18O-labeled precursors and 18O2, have shown that out of a total of eight oxygen atoms, four are derived from acetate, three from propionate, and one from molecular oxygen. The synthesis and feeding of [3-13C,3-2H3]priopionate resulted in the incorporation of [13C2H3]methyl groups at carbons 4a, 12a, 14a, 24a, and 26a, and a [13C2H2]methylene group at C-8a. This indicated that during the formation of the archaemycin furan ring, modification resulting in an aldehyde group at the C-8a position, is unlikely to occur. Feeding 2,2-[13C2H3]isobutyrate led to intact [13C2H3]methyl groups at C-29 and C-30. Efficient incorporation of [3-14C]propionate (8.45% specific incorporation per site, six sites) has been obtained. Synthesis of sodium [3-3H1]propionate from 3-trityloxy-1-p-toluenesulphonate, afforded a white powder with a specific activity of 1.03 Ci mmole-1. Feeding [3-3H1]propionate yielded S541 factor-A with a specific activity of 0.38 Ci mmole-1. Synthesis of sodium (3S)-[3-1H1,2H1,3H1]propionate from (1S)-[1-1H1,2H1]-3-trityloxy-1-p-toluenesulphonate (98 % ee), afforded a white powder with a specific activity of 2.52 Ci mmole-1.</p
Men's narratives of the body and sport
No full textThis book contains stories which are experienced and written by ten white middle-class academic men and one woman from Australia, Finland, New Zealand, the United Kingdom and the USA. What is it that brings authors separated by such long distances together to write stories? Why have these stories been told?
All are based on autobiographical narratives stemming from the authors’ own experiences or from their interpretations of stories told by other men. Many of the story-tellers are ex- athletes, so to speak, able-bodied men. But, what happens when this feeling of masculinity begins to change or even disappear? What does it mean when a familiar body becomes troublesome, disruptive, alien, or even anguished?
This book opens an interesting and fresh avenue in the ‘city’ of gender studies. It is a rather unusual book in the field of social science — unusual in a positive sense. The book can be recommended to students and teachers working in fields engaged, whether practically or theoretically, with the living body. Take your own place as a reader.unknown accessibilityei tietoa saavutettavuudest
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
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
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