1,720,966 research outputs found
Investigation of the evolutionary history of common bean (Phaseolus vulgaris)
Get PDFGli studi evolutivi, basati sull'analisi delle forme selvatiche, sono fondamentali per lo sviluppo dei programmi di breeding perché forniscono informazioni sulla diversità genetica disponibile che può essere utilizzata per ripristinare la variabilità persa durante la domesticazione. Il fagiolo comune (P. vulgaris) è uno dei legumi più importanti per il consumo umano e la sua singolare storia evolutiva ne fa un modello per lo studio dell’evoluzione delle colture.
Si possono individuare tre popolazioni selvatiche e geograficamente distinte in Mesoamerica, nelle Ande e in nord Perù-Ecuador. Ad oggi, diverse ipotesi sull’origine del fagiolo comune sono state proposte. L’obiettivo di questo lavoro è risolvere il dibattito sull'origine del fagiolo comune attraverso l'analisi della sua filogenesi a livello plastidiale e nucleare. Abbiamo ricostruito la filogenesi del fagiolo comune con SNP plastidiali e cloroplasti assemblati de-novo, con cui abbiamo anche stimato il tempo di divergenza tra i pool genici. I risultati hanno suggerito due eventi migratori, dal Mesoamerica al nord del Perù-Ecuador (~150.000 anni fa) e dal Mesoamerica alle Ande (~90.000 anni fa). Infine, marcatori nucleari sono stati utilizzati per studiare la storia evolutiva a livello nucleare. Per rispettare il requisito di assenza di ricombinazione, gli SNP delle regioni centromeriche sono stati selezionati e utilizzati per le analisi.
Sebbene i dati plastidiali riflettano chiaramente un'origine monofiletica e mesoamericana del fagiolo comune e non identifichino il pool genetico del Nord Perù-Ecuador come specie diversa, questa popolazione ha comportamenti discordanti quando si analizzano i marcatori nucleari dell'intero genoma e gli SNP localizzati in regioni non ricombinanti.
Oltre a far luce sull'origine del fagiolo comune, questo lavoro rappresenta un interessante esempio dell'effetto della ricombinazione nelle analisi filogenetiche, confermando il ruolo chiave dei cloroplasti in questo tipo di studi.Evolutionary studies, based on the analysis of wild forms, are fundamental for the development of breeding programs because they give information about the available genetic diversity that can be utilized to recover the variability lost during domestication. One of the most important grain legumes for human consumption is common bean (P. vulgaris). The peculiar evolutionary history of this species makes it a model for the study of crop evolution. Three different wild eco-geographical gene pools can be recognized: the Mesoamerican, the Andean, and the North Peru -Ecuador gene pool. To date, numerous studies investigated the origin of common bean and different hypotheses have been proposed. In this thesis, we aimed at solving the open discussion about the origin of common bean through the investigation of its phylogeny at plastid and nuclear level. We reconstructed the phylogeny of common bean with plastid SNPs and de-novo assembled plastomes, wherewith we also estimated the divergence time among gene pools. The results suggested two migration events: from Mesoamerica to North Peru -Ecuador occurred ~150.000 ya and one from Mesoamerica to South Andes arisen ~90.000 ya. Finally, nuclear data of a set of 10 accessions were used to study the evolutionary history at nuclear level. To respect the assumption of absence of recombination, SNPs from the centromeric regions were selected and used for the analyses.
Albeit the analyses of plastid SNPs and whole plastomes clearly reflect a monophyletic and Mesoamerican origin of common bean and do not identify the North Peru-Ecuador gene pool as a different species, we found that this population has discordant behaviors when analyzing whole genome nuclear markers and SNPs located in non-recombinant regions.
In addition to shed light on the origin of common bean, this work represents an interesting example of the effect of recombination in phylogenetic analyses, confirming the key role of chloroplast genomes in this kind of studies
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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