950 resultados para character tracing


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Rapid divergence in postmating-prezygotic characters suggests that selection may be responsible for generating reproductive barriers between closely related species. Theoretical models indicate that this rapid divergence could be generated by a series of male adaptations and female counteradaptations by means of sexual selection or conflict, but empirical tests of particular mechanisms are generally lacking. Moreover, although a male–female genotypic interaction in mediating sperm competition attests to an active role of females, molecular or morphological evidence of the female's participation in the coevolutionary process is critically needed. Here we show that postmating-prezygotic variation among populations of cactophilic desert Drosophila reflects divergent coevolutionary trajectories between the sexes. We explicitly test the female's role in intersexual interactions by quantifying differences in a specific postmating-prezygotic reproductive character, the insemination reaction mass, in two species, Drosophila mojavensis and Drosophila arizonae. A series of interpopulation crosses confirmed that population divergence was propelled by male–female interactions, a prerequisite if the selective forces derive from sexual conflicts. An association between the reaction mass and remating and oviposition behavior argues that divergence has been propelled by sexually antagonistic coevolution, and potentially has important implications for speciation.

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Let G be the fundamental group of the complement of the torus knot of type (m, n). It has a presentation G = . We find a geometric description of the character variety X(G) of characters of representations of G into SL(3,ℂ), GL(3,ℂ) and PGL(3,ℂ).

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We compute the E-polynomial of the character variety of representations of a rank r free group in SL(3,C). Expanding upon techniques of Logares, Muñoz and Newstead (Rev. Mat. Complut. 26:2 (2013), 635-703), we stratify the space of representations and compute the E-polynomial of each geometrically described stratum using fibrations. Consequently, we also determine the E-polynomial of its smooth, singular, and abelian loci and the corresponding Euler characteristic in each case. Along the way, we give a new proof of results of Cavazos and Lawton (Int. J. Math. 25:6 (2014), 1450058).

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Esta tese é dividida em duas partes: traçar a filogenia de Sericothripinae Karny, 1921 e realizar uma revisão taxonômica das espécies neotropicais. Para a análise filogenética, estados de caracteres morfológicos foram examinados entre Sericothripinae e Thysanoptera-Terebrantia relacionados, e as relações genéricas e supragenéricas foram exploradas. O monofiletismo de Sericothripinae foi recuperado, mas o formato do metasterno, usado na classificação dos gêneros, provavelmente não reflete a filogenia. De acordo com estudos moleculares recentes, o grupo genérico Scirtothrips em conjunto com o gênero Echinothrips Moulton, 1911 foram recuperados como intimamente relacionados aos Sericothripinae, mas, neste trabalho, Psilothrips Hood, 1927 e Pseudothrips Hinds, 1902 foram recuperados como não relacionados com Sericothripinae. Muitos estados de caracteres morfológicos entre os Sericothripinae são considerados homoplásticos e, na ausência de análises moleculares adequadas, alterações formais de nomenclatura não foram realizadas. Na revisão taxonômica, 14 novas espécies de Sericothripinae da região Neotropical são descritas. Chaves ilustradas foram elaboradas para as fêmeas de sete espécies de Hydatothrips Karny, 1913 e 41 espécies de Neohydatothrips John, 1929, principalmente do Brasil, mas incluindo todas as espécies registradas do sul da fronteira entre o México e os EUA até o extremo sul da América do Sul. Espécies de plantas em que associações-hospedeiras foram registradas são indicadas sempre que possível, comentários são elencados para as poucas espécies de importância econômica e uma chave para imaturos de segundo instar de cinco espécies é proposta. Neohydatothrips burungae (Hood, 1935) stat. rev. e N. aztecus Johansen, 1983 stat. rev. são retiradas de sinonímia com N. signifer (Priesner, 1932), ao passo que Sericothrips denigratus De Santis, 1966 syn. n. é sinonimizada com N. burungae. Hydatothrips williamsi (Hood, 1928) comb. n. é realocado de Neohydatothrips e, com isso, houve um caso de homônimo no gênero. Para resolver esse problema, H. tareei nom. nov. é proposto para H. williamsi Mound e Tree, 2009, da Austrália.

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We compute the E-polynomials of the moduli spaces of representations of the fundamental group of a once-punctured surface of any genus into SL(2, C), for any possible holonomy around the puncture. We follow the geometric technique introduced in [12], based on stratifying the space of representations, and on the analysis of the behavior of the E-polynomial under fibrations.

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This dissertation looks at the creative identity of an American yoga, both rooted in its Indic origins and radically transformed in its U.S. manifestations. It traces the broad historical transactions of yoga in terms of East and West, Secular and Religious, authenticity and idealized conception, as well as provides a critical historical genealogy of Anusara and Sridaiva yoga. Furthermore, the project relates yoga to the identity, power, and knowledge dynamics of pre-modern, modern, and postmodern histories and interpretations of yoga and Tantra, multiple theoretical discourses, and the embodied practices of individuals within Indian and American contexts. I argue that there is a unique and polysemous yogic identity in America, and that this identity has developed from a messy process of transaction between Indian and Western modes of being and knowing. Furthermore, the current Americanized culture of yoga brings along with it narratives of specific value. American yoga displays a particularly consumptive quality of yogic lifestyle that reflects a cultural atmosphere of reinvention and a merging of profit and personal purpose. American yoga’s identity today is entrepreneurial, branded, business oriented, and marketed for consumption. This dissertation shows how the American yogic identity is in flux, continuously fracturing and multiplying into various and novel understandings that relate to yoga’s past and to the market value for today’s American consumer. It examines the moving nature of yoga in the American landscape as what Jared Farmer calls a “center of creativity” and as a display of excess and choice. The discussion of yoga is further located in John Friend’s styles of yoga and/or lifestyle practices, Anusara and Sridaiva, as they both redefine and further remove yoga from established Indian markers of identity. My locations as American yogi, as comparativist, as ethnographer, and as a Bachelor of Science in Advertising and Marketing also situate this analysis.

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Small leaf containing a handwritten extract from a November 12, 1804 letter by Rev. Joseph Lathrop to Rev. John Lathrop recommending Rev. Jesse Appleton as the successor to Dr. Tappan.

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One-page handwritten remembrance written by "B. Kent," beginning "Hark, tis a voice on high--'Come to thy rest..."

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Reviews of the sport psychology literature have identified a number of models of athlete development in sport (Alfermann & Stambulova, 2007; Durand-Bush &Salmela, 2001). However, minimal research has investigated the origins of knowledge from which each model was developed. The purpose of this study was to systematically examine the influential texts responsible for providing the basis of athlete development models in sport. A citation path analysis of the sport psychology literature was used to generate a knowledge development path of seven athlete development models in sport. The analysis identified influential texts and authors in the conceptualization of athlete development. The popula-tion of 229 texts (articles, books, book chapters) was selected in two phases. Phase1 texts were articles citing seven articles depicting models of athlete development(n  75). Phase 2 included texts cited three or more times by Phase 1 articles (n  154). The analysis revealed how the scholarship of Benjamin Bloom (1985) has been integrated into the field of sport psychology, and how two articles appearing in 1993 and 2003 helped shape present conceptualizations of athlete development

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A new interview procedure is proposed for collecting valid information on the acquisition of high-level performance in sport. The procedure elicits verifiable information on the development of athletes' achievements in their primary sport, as well as factors that might influence performance, including involvement in other sporting activities, injuries, physical growth and quality of training resources. Interviewed athletes also describe their engagement in specific training and other relevant activities during each year of their development as well as how they experienced each type of activity. The collected information is then examined to identify those aspects of the athletes' recall of their development that meet criteria of reliability and validity. Recommendations to coaches and scientists are discussed for how retrospective interviews can uncover aspects of development that distinguish elite from less accomplished athletes.

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EU and national policy-makers argue that the single services market is a key to EU growth, but that many barriers to services market access remain. Grasping the scope, nature and economic meaning of these barriers, however, has proven rather difficult. This is exactly what the present CEPS Special Report helps the reader to do. We trace all market access barriers in services, as far as the data allow, and attempt to understand their nature and economic meaning (given that they are usually forms of domestic regulation) and discuss aspects of the measurement of restrictiveness. We make a sharp distinction between market access barriers restrictions in a non-EU WTO/GATS environment and intra-EU ones, and demonstrate the significant difference in ambition between the two. The paper specifies in detail the progress made by the EU's horizontal reform in services markets, documenting the removal of many cross-border obstacles to trade in services and establishment. Finally, following these conceptual and descriptive analyses, a brief assessment of access restrictiveness indices is provided for both the non-EU WTO environment and for intra-EU services access barriers.