1,720,958 research outputs found
Efectividad de la dispersión de semillas de Olea europaea por aves frugívoras nativas: una comparación entre poblaciones cultivadas y naturalizadas
Get PDFFil: Barrera, Mateo. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Carrera de Ciencias Biológicas; Argentina.Las plantas exóticas invasoras de frutos carnosos tienen la capacidad de dispersar sus semillas al establecer
mutualismos con aves frugívoras nativas, como es el caso de Olea europaea en diversas regiones del
mundo donde fue introducida como cultivo. Si bien en el Valle de Traslasierra, Córdoba, es posible
observar tanto olivos cultivados como naturalizados, se desconoce qué vínculo tiene la especie con las
aves frugívoras de la región y qué implica ello para su proceso de invasión. En este contexto, se
describieron características individuales y poblacionales en sitios donde la especie está naturalizada y se
investigaron aspectos cuantitativos y cualitativos de la efectividad de la dispersión de sus semillas. En
primer lugar, se analizó la composición etaria de las poblaciones naturalizadas identificadas, y se comparó
el tamaño de sus frutos y semillas con olivos de poblaciones cultivadas. Luego, se caracterizaron los
ensambles de aves mediante observaciones de frugivoría en árboles focales de ambas poblaciones y se
comparó la cantidad de semillas consumidas. Por último, se realizaron experimentos de siembra en
invernadero, donde se evaluó el efecto del consumo de frutos por las principales aves dispersoras
identificadas (i.e., Patagioenas maculosa, Turdus rufiventris y T. amaurochalinus), del sitio de origen
(olivo cultivado o naturalizado) y del tamaño de las semillas sobre la germinación, mortalidad y viabilidad
de las mismas. En la mayoría de los sitios analizados se detectó un alto número de plántulas y juveniles,
indicando un reclutamiento activo de nuevos individuos en el bosque serrano de Traslasierra. Se
observaron diez especies de aves frugívoras, de las cuales cinco fueron catalogadas como dispersoras
legítimas y cinco como consumidoras de pulpa. En cultivos, dos especies de Patagioenas consumieron
mayor cantidad de frutos, mientras que en poblaciones naturalizadas fueron dos especies de Turdus. Tras
nueve meses de siembra, la germinación fue nula debido a la dormición que caracteriza la especie, pero
las semillas tanto cultivadas como naturalizadas presentaron embriones viables que sobrevivieron el paso
por el tracto digestivo de las aves. Además, se observó que los frutos y semillas de olivos cultivados
tuvieron mayor tamaño que los de olivos naturalizados y que esto se asociaba significativamente a una
menor mortalidad y mayor viabilidad embrionaria. Es muy probable que los cultivos de olivos sean fuentes
eficientes de propágulos que las palomas dispersan a larga distancia, mientras que las poblaciones
naturalizadas se expandirían por la dispersión a corta distancia ejercida por zorzales. Se sugiere que,
aunque el proceso de invasión del olivo en la región es incipiente, éste se vería favorecido principalmente
por las poblaciones cultivadas, cuyas semillas de gran tamaño son dispersadas eficazmente y mantienen
su potencial de germinación.Fil: Barrera, Mateo. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Carrera de Ciencias Biológicas; Argentina
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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