1,720,953 research outputs found
Spacial and temporal variation of the composition and structure of the cladocera community (crustacea), in an annual cycle in the ciénaga de paredes (santander - colombia).
No full textLas ciénagas por su ubicación en las tierras bajas tropicales presentan características especiales, y son consideradas por algunos autores como planos de inundación. En la Ciénaga de Paredes (73°45’-73°49’W y 7°26’-7°29’N), ubicada en el Departamento de Santander (Colombia), se buscó determinar la composición y la variación espacial y temporal de la estructura de la comunidad de Cladocera, obteniendo las muestras mediante arrastres verticales con malla de 68 µm, en ocho estaciones de muestreo, en un ciclo anual (febrero de 1998 a enero de 1999). Para encontrar la estructura de dicha comunidad, se utilizaron los números de Hill (N0, N1 y N2) y la equidad (Pielou), para encontrar la estructura. El soporte del muestreo fue calculado con los estimadores Chao 1 y 2, y la existencia de diferencias significativas entre campañas y entre estaciones, se realizó a través del ANDEVA y con una prueba a posteriori (Scheffé). Las morfoespecies encontradas (31) poseen distribución tropical, subtropical y cosmopolita; pertenecen generalmente a cuerpos de agua temporales, planos de inundación o ciénagas. Las mayores abundancias fueron registradas para Moina minuta, Moina cf. micrura, Diaphanosoma brevireme y Ceriodaphnia cornuta, las cuales representaron el 81.9% del total de individuos colectados. Los resultados obtenidos por los estimadores de riqueza indican que si se aumentara el esfuerzo de muestreo con las técnicas utilizadas, no incrementaría el número de morfoespecies. Con respecto a la variación espacial de la estructura, la Estación V presento mayor equidad, riqueza y diversidad, pero menor densidad numérica, esta condición muestra la diferencia de esta estación en comparación con las demás, su tendencia atípica puede ser explicada posiblemente por la hipótesis de la perturbación intermedia, ya que dicha estación se encuentra cerca al afluente principal de la Ciénaga (Quebrada La Gómez). En la variación temporal, la estructura de Cladocera cambió a lo largo de las campañas de muestreo, ya que la equidad y la riqueza presentaron diferencias significativas, que se evidencian en el cambio de la abundancia relativa de las morfoespecies, mas no en la densidad numérica de Cladocera. Esto es causado posiblemente por las fluctuaciones de la precipitación y el nivel del agua. En general la estructura de Cladocera en la Ciénaga de Paredes, presentó heterogeneidad espacial y temporal en las ocho estaciones muestreadas y en un ciclo anual. SPACIAL AND TEMPORAL VPregradoBiólogoThe “ciénagas” for their location in the tropical lowlands present special features; they are considered by some authors like floodplains. In the Ciénaga de Paredes (73°45'-73°49'W and 7°26'-7°29'N), located in the Departamento de Santander (Colombia), were obtained biological samples with a vertically hauled net of 68 µm, in an annual cycle (February 1998 to January 1999) and in eight sample stations, with the purpose of determining composition and spatial and temporal variation of the structure of the Cladocera community. Were used the Hill numbers (N0, N1 and N2) and evenness (Pielou) to find the structure. The sampling support was calculated with the Chao 1 and 2 estimates, and the existence of significant differences among field trips and among stations, was carried out through ANDEVA with a posteriori test (Scheffé). The finding morphospecies (31) displayed tropical, subtropical and cosmopolitan distribution; generally belong to temporal water bodies, floodplains or “ciénagas”. The highest abundances were registered for Moina minuta, Moina cf. micrura, Diaphanosoma brevireme and Ceriodaphnia cornuta, which represented 81.9% of the total collected individuals. The results obtained by the richness estimates suggest that if the sampling effort was increased with the used techniques, the morphospecies number would not be increased. With regard to spatial variation of the structure, the station V showed higher evenness, richness and diversity, but lower numeric density; this condition shows that station is different from the other ones, its atypical tendency should be explained by the intermediate disturbance hypothesis, because this station is near to the main tributary of the “ciénaga” (“Quebrada La Gómez”). In the temporal variation, the Cladocera structure changed among field trips, the evenness and the richness showed significant differences, for this reason the morphospecies relative abundance varied but not the numeric density of Cladocera. This should be caused by the influence of the precipitation and water level. The Cladocera structure in the Ciénaga de Paredes showed spatial and temporal heterogeneity in the annual cycle and in the eight sample stations studied
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
- …
