1,720,952 research outputs found
The emb proteins in Mycobacterium smegmatis
Get PDFMycobacterium tuberculosis, the causative agent of tuberculosis, was once thought to be a ghost of the past. However, the emergence of drug resistant strains has brought this bacterium back into the spot light. Ethambutol, a compound with structural similarity to D-arabinose, has been shown to have many inhibitory effects on M. tuberculosis and other mycobacterial species. Some of these activities include: inhibition of synthesis of the arabinan constituent of the cell wall arabinogalactan (AG), inhibition of RNA metabolism, and phospholipid synthesis. Likewise, this inhibition of arabinan synthesis extends to that of lipoarabinomannan (LAM). One of the most significant components of all mycobacterial cell walls is LAM; it has been implicated as a central molecule involved in the virulence and immunopathogenesis of tuberculosis. The arabinan of LAM is attached to a mannan backbone which extends from a phosphatidylinositol mannoside anchor at the reducing end. Recent research efforts have been directed towards showing that the Emb proteins are involved in arabinan synthesis. These proteins are conserved throughout all mycobacterial species, and through the use of computer program algorithms (such as SOSUI, TMPRED), it has been predicted that there are 11-13 transmembrane domains in the N-terminal region of the proteins. This correlates to approximately 670 amino acids. Also, these programs showed a soluble globular C-terminal domain accounting for approximately 430 amino acids. Specifically, it was found that EmbC targets the arabinan of LAM. This was made possible by the inactivation of the embA, embB, and embC genes individually, and subsequently looking at the resulting structural alterations on the arabinan component of cell wall AG and LAM. With this knowledge, the establishment of the catalytic site of the embC gene that specifically controls the arabinosylation of lipomannan to give mature lipoarabinomannan was necessary. Generation of hybrids with variation in the N-terminus of the EmbC protein is the current strategy being used to pursue this information. An EmbC/B hybrid was created by the fusion of the N-terminus of EmbC and the C-terminal domain of EmbB. This included 668 amino acids from the N-terminal of EmbC, fused with the last 407 amino acids of EmbB. This gene fusion was cloned into the pVV16 shuttle vector and electroporated into M. smegmatis ΔembC. LAM was then extracted from these hybrid cells, and analysis showed that the EmbC/B hybrid resulted in a shortened form of LAM. After further biochemical studies on this truncated LAM such as glycosyl compositional analysis, endoarabinase digestion followed by HPAEC (High-pH anion-exchange chromatography) profiling, and mass spectrometry analysis, it was shown that LAM was not only truncated, but had a structural alteration where the nonreducing end resembled that of the arabinan of AG. After such exciting results, current work continues with the generation of hybrids. The formation of the 50:50 EmbC/B hybrid containing approximately 580 amino acids of each of the EmbC and EmbB genes has been completed. This final construct has been transformed into the ΔembC mutant by electroporation and biochemical analysis is being performed. Results pertaining to the hybrids capacity to complement the LAM defect will be discussed in this poster presentation. This new 50:50 fusion will be essential in giving us the knowledge on the contribution of the first eight transmembrane domains of the EmbC protein in LAM biosynthesis.College Honors
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
- …
