1,720,953 research outputs found
Persistencia de marcadores para Bacteroidales como microorganismos indicadores de trazabilidad en tomate y melón contaminados artificialmente
Get PDFLas bacterias indicadoras de contaminación fecal (FIB) no permiten rastrear la fuente de contaminación (MST), por lo que miembros del orden Bacteroidales se han propuesto como indicadores alternativos, dada su abundancia en las heces y especificidad de hospedero; sin embargo, a la fecha, su compartamiento solo se ha evaluado en agua y su persistencia no está bien estudiada. En este trabajo se evaluó la persistencia de los marcadores de Bacteroidales y FIB en tomate y melón contaminados artificialmente y almacenados bajo dos condiciones de temperatura y humedad. Las bacterias utilizadas fueron Escherichia coli ATCC 25922, Enterococcus faecalis ATCC 19433; Bacteroides thetaiotamicron (de origen humano) y las cepas de Bacteroidales spp. 15PIG y 28COW, de origen porcino y bovino respectivamente. Para determinar la persistencia de los Bacteroidales, heces estériles se inocularon con las cepas bacterianas y se utilizaron para contaminar filtros (superficia lisa), corchos (superficie rugosa), tomates y melones, que se almacenaron bajo condiciones de refrigeración (10ºC/95%HR) y medio ambiente (25ºC/65%HR) hasta por 25 días, monitoreando la persistencia de las FIB por microbiología convencional y marcadores de Bacteroidales por qPCR. Se encontró que en filtros y corchos ambas FIB disminuyeron en concentración durante el estudio, E. coli redujo hasta 3.28 logUFC/ml en refrigeración a los 25 días y en medio ambiente fue indetectable hacia los 10-20 días. Para el caso de E. faecalis a los 25 días se redujo de 0.52 a 2.82 logUFC/ml. Cuando el ensayo se realizó en vegetales, ambas FIB aumentaron su concentración en ambas condiciones de almacenamiento, disminuyendo posteriormente. Para el caso de los marcadores de Bacteroidales todos fueron detectados en las muestras; con valores equivalentes a 1.15-5.68 logUFC. El análisis de ANOVA demostró que la humedad fue el factor que mayor efecto tuvo en la persistencia de las FIB; en tanto que para Bacteroidales no hubo diferencia (P≤0.05) en los valores durante el tratamiento. Con esto se demostró la persistencia de marcadores (general y especie-específicos) de Bacteroidales durante la vida de anaquel de tomates y melones contaminados; por lo que pueden ser empleados como indicadores para determinación de la fuente de contaminación fecal en complementariadad o reemplazo de las FIB.
ABSTRACT Fecal Indicator Bacteria (FIB) requires time and selective culture media to grow and do not allow microbial source tracking (MST). Bacteroidales have been proposed as alternative indicators due to their abundance on feces and host specificity, allowing MST. Bacteroidales marker behavior has been mainly evaluated on water and their persistence is not well undestod. Due to this, persistence of hostspecific Bacteroidales markers and FIB on tomatoes and melons artificially contaminated and stored under two different environmental conditions was evaluated. The strains used were Escherichia coli ATCC 25922, Enterococcus faecalis ATCC 19433; Bacteroides thetaiotamicron (human origin); and Bacteroidales 15PIG and 28COW (pig and cow origin). To determinate Bacteroidales persistence, sterile feces from the different hosts were contaminaed with the strains and applied to filters, flat cork, tomatoes and melons, and stored under refrigeration (10ºC/95%HR) and room conditions (25ºC/65%HR), Persistence was monitoring up to 25 days. FIB were analyzed by selective agar plating and Bacteroidales markers by qPCR. Both FIB showed reductions onto filters and cork surfaces during the study, E. coli reduced up to 3.28 logCFU/ml under refrigeration conditions and not detected between days 10 to 20 at room conditions. E. faecalis showed reductions from 0.52 to 2.82 logCFU/ml in both treatments by day 25. FIB increased numbers in produce in both storage conditions, showing a slight reduction by the end of the study at room conditions. All Bacteroidales markers were detected in all samples at levels 1.15-5.5,569 logCFU/ml. ANOVA analysis showed that persistence of FIB was affectd mainy by humidity. Bacteroidales markers did not show differences between them. Persistence of universal and specie-specyfic Bacteroidales markers were proved during all self life of tomatoes and melons contaminated artificialy. We conclude Bacteroidales markers are able to be used for MST pourpuse, together or instead of FIB
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
- …
