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The proteins needed for indole induced biofilm formation and their functions in E. coli DH5α
No full textABSTRACT
之前我們已經以二維膠片的分析技術發現當大腸桿菌的重要病原菌O157被處以抗生素枯草桿菌素時會經由EvgS/EvgA雙蛋白質系統引起Tryptophanase基因的表現，並進而分解Tryptophan引起Indole的產生，接著引起生物膜的形成以及一系列相關蛋白質的表達。
在這篇論文中我們以被跳躍子基因破壞的大腸桿菌DH5α突變株作為研究材料，進一步研究哪些基因為由Indole引起大腸桿菌形成生物膜所必須，結果發現當yhiP、cyaA、trkA、phr、fimE突變時大腸桿菌無法為Indole引起生物膜的形成。經由互補實驗我們也進一步證實這些基因確實為Indole引起大腸桿菌形成生物膜所必須。我們也利用報導基因分析再進一步證實Indole確實能引起這些基因的表現，其中又以yhiP、cyaA活性增加至200% 以上最為明顯﹔另外經由互補實驗和報導基因分析我們也部分的闡明了Indole與這些基因上游的轉錄調控子之間的關聯﹔以及各種常見抗生素對這些基因表現的影響。除此之外，在這篇論文中也以butanol等實驗材料分析了這些基因對大腸桿菌形成生物膜以對抗逆境的貢獻。
另外由於我們之前發現了在大腸桿菌中蛋白質B0363能為autoinducer (indole)引發表現且為金黃色葡萄球菌IcaA的類似物，因為它被預測是被分泌至細胞膜外側的部分水溶性蛋白質較易於分析，所以在這篇論文中我們也表達純化了這個蛋白質並做了相關的活性分析並且得到了高純度且具有活性的蛋白質。ABSTRACT
By using the two-dimensional gel method, we already discovered that when E. coli O157 was exposed to bacitracin, the expression of tryptophanase gene was induced through the EvgS/EvgA two-component system. Tryptophanase then converted tryptophan to indole,which caused biofilm formation as well as a series of related protein expression.
In this study, we screened the E. coli DH5α transposon library mutants to find out which genes are crucial for indole induced biofilm formation. These results show that when yhiP, cyaA, trkA, phr, and fimE genes are disrupted by transposon, indole can not induce these mutant strains to form biofilm. By using complementary assays, we confirmed that these genes are truly necessary for Indole induced biofilm formation in E. coli DH5α. Besides, we also used the reporter gene analysis method to further confirm that indole can cause these genes expressions with the promoter activity of yhiP, cyaA increased up to 200%. Moreover, we also clarified the relationship between indole and expressions of some transcription factor genes upstream to these genes, as well as the influences of each kind of common antibiotic to the expressions of these genes. In addition, we also used other experiment material such as butanol to test if expressions of these genes also contribute to the resistence to the adverse circumstance when E. coli formed biofilm.
Besides, the expression of B0363 can be induced byindole in E.coli. B0363 is an analogous protein of IcaA of staphylococcus, which is secreted to outside of cell after transcription. I also expressed and purified this protein successfully and made sure it has catalytic activity
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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