1,720,953 research outputs found
Evaluation of the potential digestive assimilation of nanoplastics
No full textEn los últimos años, los nanoplásticos han empezado a ser considerados contaminantes muy importantes en los océanos, ya que han atraído la atención de la comunidad científica. Los plásticos a escala nanométrica pueden provenir de dos fuentes, ya sea por la degradación y abrasión de piezas de plástico o presentar ese tamaño desde su fabricación. La omnipresencia de estos nanomateriales pone sobre la mesa la necesidad de estudiar el impacto ambiental que puedan tener en diferentes ecosistemas. Uno de los que más preocupación han generado es el ecosistema marino, ya que es una basta fuente de alimentos para el humano. De los organismos que pueden verse afectados directamente por la interacción con los micro y nanoplásticos están los detrítivos, como el camarón. Para conocer el efecto de los nanoplásticos en la especie del camarón blanco del Pacífico Litopenaeus vannamei, se expusieron 24 camarones durante 33 días a concentraciones de 0, 0.25, 0.5 y 1 mg/g de NanoPET. Se prepararon las dietas para los camarones y se le añadieron nanoplásticos que etiquetados con Rojo Nilo con la intención de confirmar su presencia en el alimento. Se analizaron la hemolinfa y los hepatopáncreas de los organismos. Se evaluaron los niveles de glucosa, proteína total, colesterol y triglicéridos en la hemolinfa de los camarones. También, se midieron los niveles de nitritos y de ROS en el hepatopáncreas. Finalmente, se evaluó la expresión relativa de los genes referentes al sistema antioxidante (SOD, CAT, GPx y GST). Se detectó estrés agudo en la hiperglucemia de la hemolinfa. Los genes SOD, CAT y GPx también mostraron señales de activación del sistema antioxidante en los organismos expuestos a las concentraciones 0.5 y 1 mg/g de NanoPET. Esto permitió que hubiera una inhibición en la producción de ROS. Se registró una activación del sistema antioxidante derivado de la inflamación detectada en las células del hepatopáncreas de los camarones expuestos al NanoPET contenido en los alimentos.In recent years, nanoplastics have attracted the attention of the scientific community as very important pollutant in the oceans. Nanoscale plastics are originated from different sources, either from the environmental degradation and abrasion of plastic pieces, or by the direct manufacture of nanosized plastic material. The widespread presence of these nanomaterials rise the concern of their environmental impact on different ecosystems. Marine ecosystem, being an important food source for humans, is one of the most affected. Among the organisms that can be directly affected by the interaction with micro and nanoplastics are detritus scavengers, such as shrimp. In order to know the effect of nanoplastics on the Pacific white shrimp species Litopenaeus vannamei, were feed for 33 days with a feed containing different concentrations of NanoPET (0, 0.25, 0.5 and 1 mg/g). The nanoplastics were labelled with Red Nile with the intention of confirming their presence in the food. Hemolymph and hepatopancreas tissues from the organisms were analyzed. Glucose, total protein, cholesterol and triglycerides levels were evaluated in shrimp hemolymph. In addition, nitrite and ROS levels in the hepatopancreas were measured. Finally, the relative gene expression of some antioxidant proteins (SOD, CAT, GPx and GST) was evaluated. Acute stress was detected in the hyperglycemia of hemolymph, inhibition of nitrites as affectation in the immune system and presence of ROS in the concentrations of 0.25 and 0.5 mg/g NanoPET. The SOD, CAT and GPx genes showed signs of antioxidant system activation in organisms exposed to the 0.5 and 1 mg/g concentrations of NanoPET. The activation fo these genes inhibited the production of ROS. An activation of the antioxidant system derived from the inflammation was also detected in the hepatopancreas tissue of shrimp feed with a diet containing NanoPE
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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