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Different approaches for the genetic evaluation of oocyte and embryo production in the dairy Gir breed
No full textAs tecnologias de reprodução artificial, como a produção de oócitos e embriões, desempenham um papel importante na disseminação de material genético superior, contribuindo de forma efetiva para acelerar o ganho genético de características de interesse comercial no sistema de produção e no desenvolvimento da cadeia produtiva de carne e leite. Frente a isso, o objetivo deste estudo foi avaliar diferentes metodologias na avaliação genética da produção de embriões e oócitos em bovinos Gir Leiteiro e identificar as estratégias mais adequadas para futuras avaliações genéticas da raça. No primeiro capítulo, apresentamos a revisão de literatura sobre os temas que estão diretamente relacionamentos aos objetivos do nosso projeto. No segundo capítulo, utilizamos modelos de repetibilidade e regressão aleatória (RRM) para estimar parâmetros genéticos e predizer valores genéticos para a produção de oócitos e embriões, e identificamos os modelos que resultaram em maiores ganhos genéticos na produção de oócitos e embriões. No terceiro capítulo, investigamos o impacto do estresse térmico nos parâmetros genéticos e valores genéticos para produção de oócitos e embriões em animais da raça Gir Leiteiro. E, no quarto capítulo, avaliamos a eficiência dos modelos com distribuição Gaussiana (variável não transformada — LIN; transformada por logaritmo — LOG; transformada pelas distribuições de Anscombe — ANS) e Poisson (POI) na avaliação genética para a produção de oócitos e embriões. A herdabilidade estimada pelo RRM foi superior à estimada pelo modelo de repetibilidade, e o ganho genético foi maior, com acréscimos variando entre 0,02 (13,33%) e 0,26 (152,94%) ao utilizar o RRM. Observamos uma reordenação na classificação dos valores genéticos preditos dos 5% melhores touros e fêmeas ao longo da idade da doadora no momento da coleta de óocitos. É recomendável considerar o efeito do estresse térmico por meio dos índices de temperatura e umidade nas avaliações genéticas da raça para produção de oócitos e embriões e, assim, é possível selecionar animais tolerantes ao estresse térmico em características relacionadas à reprodução artificial. Também observamos o reordenamento dos melhores animais em relação às escalas de idades para coleta de oócitos e do índice de temperatura e umidade. Dessa forma, esses fatores devem ser levados em consideração no momento de identificar e selecionar os candidatos à reprodução. Ainda, identificamos que o modelo POI ajustou-se melhor aos dados e resultou em maior acurácia dos valores genéticos quando comparado aos demais modelos com distribuição de probabilidade Gaussiana (LIN, LOG e ANS). Os resultados obtidos nesta tese suportam a conclusão de que é possível obter progresso genético para a produção de oócitos e embriões por meio de seleção. Isso pode contribuir para o crescimento econômico de fazendas e demais empresas envolvidas na comercialização de embriões. Além disso, a rápida disseminação de material genético superior, proporcionada pelas técnicas reprodutivas via grande número de progênies de fêmeas com alto valor genético para diferentes características de interesse econômico, favorecem também o desenvolvimento e o retorno financeiro para os sistemas produtivos.Artificial reproduction technologies, such as the production of oocytes and embryos, play an important role in the dissemination of superior genetic material, effectively contributing to accelerate the genetic gain of traits of commercial interest in the production system and in the development of the production chain of meat and milk. In view of this, the objective of this study was to evaluate different methodologies in the genetic evaluation of the production of oocytes and embryos in Dairy Gir cattle and to identify the most appropriate strategies for future genetic evaluations of the breed. In the first chapter, we present a literature review on topics that are directly related to the objectives of our project. In the second chapter, we used repeatability and random regression (RRM) models to estimate genetic parameters and predict breeding values for oocyte and embryo production, and we identified the models that resulted in the greatest genetic gains in oocyte and embryo production. In the third chapter, we investigated the impact of heat stress on genetic parameters and breeding values for the production of oocytes and embryos in Dairy Gir animals. And, in the fourth chapter, we evaluated the efficiency of models with Gaussian distribution (non-transformed variable — LIN; transformed by logarithm — LOG; transformed by the Anscombe distributions — ANS) and Poisson (POI) in the genetic evaluation for the production of oocytes and embryos. The heritability estimated by the RRM was higher than that estimated by the repeatability model, and the genetic gain was greater, with increases ranging between 0.02 (13.33%) and 0.26 (152.94%) when using the RRM. We observed a reordering in the classification of the predicted breeding values of the top 5% sires and females along the age of the donor at ovum pick-up. It is recommended to consider the effect of heat stress through the temperature-humidity index in the genetic evaluations of the breed for the production of oocytes and embryos and, thus, it is possible to select animals tolerant to heat stress in traits related to artificial reproduction. We also observed the reordering of the best animals in relation to the age scales for age at ovum pick-up and the temperature-humidity index. Thus, these factors must be taken into account when identifying and selecting breeding candidates. Furthermore, we identified that the POI model fitted the data better and resulted in greater accuracy of the breeding values when compared to the other models with Gaussian probability distribution (LIN, LOG and ANS). The results obtained in this thesis support the conclusion that it is possible to obtain genetic progress for the production of oocytes and embryos through selection. This can contribute to the economic growth of farms and other companies involved in the commercialization of embryos. In addition, the rapid dissemination of superior genetic material, provided by reproductive techniques via a large number of progenies of females with high genetic value for different traits of economic interest, also favors the development and financial return for production systems
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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