1,720,953 research outputs found
Análisis funcional de esfingomielinasas neutras de Entamoeba histolytica
No full textLa virulencia de Entamoeba histolytica es un proceso multifactorial, en el que están involucrados factores tanto del hospedero como de la amiba. Entre los factores del parásito se encuentran los amebaporos, las cisteín proteasas y la lectina; sin embargo, no se descarta la participación de otras moléculas. Algunas de estas moléculas candidatas son las esfingomielinasas (SMasas), enzimas que catalizan la hidrólisis de esfingomielina (SM) produciendo ceramida, la cual está involucrada en diferentes procesos celulares como proliferación celular, apoptosis y lisis celular. En el grupo de trabajo se ha reportado que el genoma de E. histolytica posee tres genes que codifican para SMasas neutras, los cuales se expresan y producen proteínas con actividad enzimática. El objetivo del presente es el análisis funcional de las SMasas neutras, para lo cual se obtuvieron trofozoítos transfectantes para silenciar o sobreexpresar los genes que codifican para dichas enzimas. Se encontró que la actividad de SMasa neutra disminuye con el silenciamiento de los genes y aumenta con su sobrexpresión, lo que permitió evaluar su participación en la virulencia del parásito. La nSMasa3 está asociada con la muerte y lisis celular, mientras que la nSMasa1 y nSMasa2 con la destrucción de monocapas celulares. Mediante ensayos de inmunodetección y microscopía confocal se encontró que estas proteínas están asociadas principalmente a la membrana plasmática, lo que sugiere que el efecto citotóxico y citolítico es dependiente de contacto. La actividad de nSMasa aumentó en amibas expuestas a H2O2, radiación UV-C o choque térmico, sin embargo, las cepas sobre-expresantes no mostraron cambios en su actividad. Esta es la primera vez que se demuestra la participación de las nSMasas en la virulencia de E. histolytica, principalmente de la Ehnsm3.The virulence of Entamoeba histolytica is a multifactorial process, in which both host and amoeba factors are involved. Among the factors of the parasite are amebapores, cysteine proteases and lectin; however, the participation of other molecules is not ruled out. Some of these candidate molecules are sphingomyelinases (SMases), enzymes that catalyze the hydrolysis of sphingomyelin (SM) producing ceramide, which is involved in different cellular processes such as cell proliferation, apoptosis and cell lysis. In the working group it has been reported that the genome of E. histolytica possesses three genes that code for neutral SMasas, which are expressed and produce proteins with enzymatic activity. The objective of the present is the functional analysis of the neutral SMasas, for which transfectant trophozoites were obtained to silence or overexpress the genes that code for these enzymes. It was found that the activity of neutral SMase diminishes with the silencing of the genes and increases with its overexpression, which allowed to evaluate its participation in the virulence of the parasite. NSMasa3 is associated with cell death and lysis, while nSMasa1 and nSMasa2 with the destruction of cellular monolayers. By means of immunodetection and confocal microscopy tests, it was found that these proteins are mainly associated with the plasma membrane, which suggests that the cytotoxic and cytolytic effect is contact-dependent. The activity of nSMase increased in amoebae exposed to H2O2, UV-C radiation or thermal shock, however, the over-expressing strains did not show changes in their activity. This is the first time that the participation of the nMasas in the virulence of E. histolytica, mainly of the Ehnsm3, has been demonstrated
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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