1,721,013 research outputs found
Genetic parameters and selection indices for a population of Pinus elliottii Engelm. var. elliottii
Get PDFP. elliottii Engelm. var. elliottii is an important exotic plantation species in Zimbabwe, where it is grown for saw-timber and resin production. Three progeny tests, originating from factorial matings between parents selected in plantations, were assessed at five, eight and 15 years. The objectives of the study were to characterise quantitative genetic variation in the population through the estimation of genetic parameters, and to use these parameters in combined indices to select for specified breeding objectives for P. elliottii in Zimbabwe. All traits of interest were under a reasonable degree of additive genetic control, and the magnitudes of nonadditive genetic variances were almost invariably much less than those of additive genetic variances. Narrow-sense heritabilities for growth traits, wood density and resin yield were moderate to high, ranging from 0.3 - 0.42; those for stem straightness and branching traits were lower, ranging between 0.10 and 0.25. Genetic correlations at each of the assessment ages were more variable; of most consequence for this study were the slight negative correlations between wood density and both stem diameter and volume, and the slight positive correlation between density and height. Age-age correlations for growth traits were high, indicating potential for early selection. Age-age correlations for other traits ranged from moderately negative to highly positive. Although statistically significant for many traits, genotype-environment interaction was judged by a number of criteria to be of little practical importance. No one site was the most efficient for selection across the range of traits for establishment at other sites; rather, a set of pooled parameters was estimated for application on sites typical of those on which commercial plantations of P. elliottii are established. Selection indices were constructed for four breeding objectives, representing differing assumptions about the relative importance of saw-timber and resin production. Indices for both direct and indirect selection were compared in terms of genetic gain, efficiency and accuracy, which were influenced by the differential weighting of traits in the breeding objective. The highest gains, efficiency and accuracies were for the breeding objective of saw-timber only; increasing the emphasis on resin production reduced each of these parameters, and also had a more adverse impact on wood density. For a breeding objective corresponding to or emphasizing saw-timber production, selection based on diameter or height at five years was best; selection on the latter has the advantage of maintaining wood density at around its present level. Should resin production also be important, resin yield or a correlated trait must be included in the index. Efficiencies of indirect selection were highest at five years, regardless of the breeding objective or selection criteria considered. The lack of economic information was a considerable hinderance in conducting these analyses. The construction of more complete indices, incorporating information from all siblings represented in the factorial mating design, was also investigated for the breeding objective of saw-timber production. These indices were compared in terms of gain and accuracy, and their effect on population structure in the subsequent generation. Selection based on the most complete index resulted in the greatest gain and accuracy, but also in the greatest reduction in additive genetic variance in the next generation. These results highlight the dilemma facing breeders charged both with achieving gains in the short term and maintaining diversity over the longer term. Breeding strategies which facilitate differential intensities of selection and breeding, and the maintenance of a large effective population size, are seen as the best means to resolve these conflicting demands; some implications for the breeding population of P. elliottii in Zimbabwe are discussed
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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