1,721,084 research outputs found
The oxidation of methanol in methylotropic bacteria
No full textMethylobacterium AM1 and Methylophilus methylotrophus are known to contain modifier proteins with the abiilty to alter the substrate specificity of methanol dehydrogenase. Both M-proteins have been reported to be soluble colourless proteins of native molecular weight 130kD, containing two identical subunits and constituting up to 6% of the soluble cell protein (Page and Anthony, 1986). This thesis reports the purification of the M-protein of M.methylotrophus by the method used previously with an additional final step which showed that the active component of the M-protein preparation was not the major protein, containing two 67kD subunits (previously designated as the M-protein band) but a minor contaminant of this protein. The active components could not be purified to homogeneity. Paracoccus denitrificans was shown also to contain a modifier protein similar to those characterised previously in terms of native molecular weight and ability to inhibit formaldehyde oxidation by MDH in a dye-linked assay at pH 9. However, its subunit molecular weight was 45kD and the quantity of this protein in the cell was much less than that of MDH. It was demonstrated that in P.denitrificans M-protein was localised exclusively within the periplasmic space of the bacterium using a lysozyme/EDTA treatment to produce spheroplasts. In order to study the effect of the M-protein from P.denitrificans upon MDH under physiological conditions it was necessary to set up a cytochrome c-linked assay, such as that described by Beardmore-Gray and Anthony (1983). Since the cytochrome c acting as electron acceptor from MDH was unknown in this organism, all cytochromes c present during methylotrophic growth were purified and tested for their ability to accept electrons from MDH. The soluble 22kD cytochrome c552 was found to be the physiological electron acceptor for MDH in P.denitrificans, contrary to previous speculation that the 30kD c553 performed this role. Cytochrome c552 was used to mediate electron flow between MDH and horse-heart cytochrome c in a physiological assay at pH 7.5. In this assay M-protein inhibited the oxidation of formaldehyde. It also diminished rates of methanol oxidation while increasing the affinity of MDH for methanol. Thus it is proposed that M-protein may have a role both in the regulation of formaldehyde and methanol oxidation. In both cases the greatest effect is observed when the molar ration of MDH to M-protein in the assay was 5:1; however, this molar ratio was much greater in periplasmic protein extracts, at least under the single set of conditions used for the growth of the bacteria, suggesting that there may be too little M-protein expressed to perform the role(s) proposed. During these studies two strains of P.denitrificans 8944 were used: one obtained from Oxford University, the other form the N.C.I.B. Although both were identical with respect to their expression of M-protein, the Oxford strain expressed two novel cytochrome c complexes during methylotrophic and heterotrophic growth, both of which were purified and characterised. The major complex (up to 25% of total cytochrome c) was shown to be a heterodymeric cytochrome c containing subunits of 30kD and 15kD. The large subunit contained three high spin haems and the small subunit two low spin haems. The functions of either complex are unknown.</p
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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