1,720,953 research outputs found
Zooplankton assemblage in a high andean reservoir (Chivor, Colombia)
No full textilustraciones, diagramas, tablasLos embalses representan importancia social y económica, ya que ofrecen servicios para las comunidades cercanas, entre ellos destacan la generación de energía eléctrica, almacenamiento de agua para consumo y en algunos casos para riego. Varios estudios han demostrado la importancia del zooplancton en los ecosistemas acuáticos basados en su rol ecológico. De esta forma es importante resaltar la importancia de ampliar el conocimiento respecto a la dinámica de este grupo, que lleve a un acercamiento al comportamiento del sistema. Este estudio se realizó en el Embalse La Esmeralda (Chivor, Boyacá), donde se definió una periodicidad de muestreo de 16 semanas, en tres estaciones de muestreo: Estación 1 zona de entrada o riberina, Estación 2 o zona de transición y Estación 3 o zona de presa, cada una con tres profundidades (superficie, media, fondo), donde se tomaron muestras de 30 L. En laboratorio se tomaron 30 ml de muestra y se realizaron los conteos por medio de cámara de sedimentación. Se probaron los supuestos estadísticos y se realizaron pruebas de Kruskal-Wallis, no pareada de Wilcoxon y t-Student para verificar diferencias significativas temporales y espaciales, además de análisis de ordenación indirecta (Análisis de Componentes Principales) y directa (Análisis de Correlación Canónica) para identificar la relación entre el componente biótico y abiótico. Los resultados mostraron tendencia neutra-alcalina, de baja mineralización y tendencia a la polimixis. Es un sistema limitado por nitrógeno y de características eutróficas. Además, se observó mayor representatividad tanto en densidad como en biomasa por parte del Cyclopoida T. decipiens (copepodito). Estos organismos, en particular copépodos y rotíferos tienen relación estrecha con variables nutricionales principalmente fósforos y sólidos. La comparación entre 2007 y 2022 mostró que la condición eutrófica del embalse se mantiene entre ambas fechas, así mismo, se mantuvo la presencia de T. decipiens, K. tropica tropica y Polyarthra sp., lo que puede estar relacionado tanto con oferta alimenticia como interacciones ecológicas (Texto tomado de la fuente).Reservoirs represent social and economic importance, as they offer services to nearby communities, including generation of electricity, water reservoirs for drinking water, and sometimes used for irrigation. Several studies have demonstrated the importance of zooplankton in aquatic ecosystems based on their ecological role. Thus, it should emphasize the importance of expanding the knowledge regarding the dynamics of this group, leading to an approach to the system behavior. La Esmeralda reservoir was the study place in Chivor, Boyacá municipality. The study sampling was during a periodicity of 16 weeks. In three sampling stations: Station 1 inlet or riparian zone, Station 2 or transition zone, and Station 3 or dam zone, and in each station 30 L samples were taken in three depths (surface, middle, bottom). To verify significant, temporal and spatial differences were used: statistical assumptions tests, Kruskal-Wallis, unpaired Wilcoxon, and Student's t-tests t. The results show a neutral-alkaline trend, low mineralization, and suspended particles accumulation with polymictic characteristics. It is a nitrogen-limited system with eutrophic characteristics. In addition, the Cyclopid T. decipiens copepodite was more representative in density and biomass. These organisms, particularly copepods and rotifers, have a close relationship with nutritional variables, mainly phosphorus and solids. The comparison between 2007 and 2022 showed that the eutrophic condition of the reservoir is maintained between both dates, likewise, the presence of T. decipiens, K. tropica tropica and Polyarthra sp. was maintained, which may be related to both food supply and ecological interactions.MaestríaMagíster en Ciencias - BiologíaLimnologí
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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