924 resultados para Relativistic many-body perturbation theory
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We propose an approach to the quantum-mechanical description of relativistic orientable objects. It generalizes Wigner`s ideas concerning the treatment of nonrelativistic orientable objects (in particular, a nonrelativistic rotator) with the help of two reference frames (space-fixed and body-fixed). A technical realization of this generalization (for instance, in 3+1 dimensions) amounts to introducing wave functions that depend on elements of the Poincar, group G. A complete set of transformations that test the symmetries of an orientable object and of the embedding space belongs to the group I =GxG. All such transformations can be studied by considering a generalized regular representation of G in the space of scalar functions on the group, f(x,z), that depend on the Minkowski space points xaG/Spin(3,1) as well as on the orientation variables given by the elements z of a matrix ZaSpin(3,1). In particular, the field f(x,z) is a generating function of the usual spin-tensor multi-component fields. In the theory under consideration, there are four different types of spinors, and an orientable object is characterized by ten quantum numbers. We study the corresponding relativistic wave equations and their symmetry properties.
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In this paper we study fermion perturbations in four-dimensional black holes of string theory, obtained either from a non-extreme configuration of three intersecting five-branes with a boost along the common string or from a non-extreme intersecting system of two two-branes and two five-branes. The Dirac equation for the massless neutrino field, after conformal re-scaling of the metric, is written as a wave equation suitable to study the time evolution of the perturbation. We perform a numerical integration of the evolution equation, and with the aid of Prony fitting of the time-domain profile, we calculate the complex frequencies that dominate the quasinormal ringing stage, and also determine these quantities by the semi-analytical sixth-order WKB method. We also find numerically the decay factor of fermion fields at very late times, and show that the falloff is identical to those showing for massless fields in other four-dimensional black hole spacetimes.
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We use the deformed sine-Gordon models recently presented by Bazeia et al [1] to take the first steps towards defining the concept of quasi-integrability. We consider one such definition and use it to calculate an infinite number of quasi-conserved quantities through a modification of the usual techniques of integrable field theories. Performing an expansion around the sine-Gordon theory we are able to evaluate the charges and the anomalies of their conservation laws in a perturbative power series in a small parameter which describes the ""closeness"" to the integrable sine-Gordon model. We show that in the case of the two-soliton scattering the charges, up to first order of perturbation, are conserved asymptotically, i.e. their values are the same in the distant past and future, when the solitons are well separated. We indicate that this property may hold or not to higher orders depending on the behavior of the two-soliton solution under a special parity transformation. For closely bound systems, such as breather-like field configurations, the situation however is more complex and perhaps the anomalies have a different structure implying that the concept of quasi-integrability does not apply in the same way as in the scattering of solitons. We back up our results with the data of many numerical simulations which also demonstrate the existence of long lived breather-like and wobble-like states in these models.
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A relativistic four-component study was performed for the XeF(2) molecule by using the Dirac-Coulomb (DC) Hamiltonian and the relativistic adapted Gaussian basis sets (RAGBSs). The comparison of bond lengths obtained showed that relativistic effects on this property are small (increase of only 0.01 angstrom) while the contribution of electron correlation, obtained at CCSD(T) or CCSD-T levels, is more important (increase of 0.05 angstrom). Electron correlation is also dominant over relativistic effects for dissociation energies. Moreover, the correlation-relativity interaction is shown to be negligible for these properties. The electron affinity, the first ionization potential and the double ionization potential are obtained by means of the Fock-space coupled cluster (FSCC) method, resulting in DC-CCSD-T values of 0.3 eV, 12.5 eV and 32.3 eV, respectively. Vibrational frequencies and some anharmonicity constants were also calculated under the four-component formalism by means of standard perturbation equations. All these molecular properties are, in general, ill satisfactory agreement with available experimental results. Finally, a partition in terms of charge-charge flux-dipole flux (CCFDF) contributions derived by means of the quantum theory of atoms in molecules (QTAIM) in non-relativistic QCISD(FC)/3-21G* calculations was carried out for XeF(2) and KrF(2). This analysis showed that the most remarkable difference between both molecules lies on the charge flux contribution to the asymmetric stretching mode, which is negligible in KrF(2) but important in XeF(2). (c) 2008 Elsevier B.V. All rights reserved.
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The aim with this Essay is to examine the two most read magazines in Sweden covering the areas of exercising, fitness, bodybuilding, diets and “wellness” –Fitness and Body. Fitness’s target group is predominantly woman, while Body is almost exclusively read by men. The analysis is first done quantitatively, by systematically categorising the contents of the magazines. Then a qualitative analysis is made. Using two different theories, Anja Hirdman’s gender concept along with her constructivistic media perspective and the theory of Symbolic Interactionism, i try to answer the following questions; Does the two magazines term of address and language differ from one and other? And if that is the case, in what way? With point of departure from contents and subject areas, how are the two magazines compounded? How can the underlying message in the different articles be interpreted?The analysis shows that both magazines followed their purpose of writing about exercising in general, diet, fitness and bodybuilding. However, the magazine Fitness writes more often then Body about matters not following the given purpose, and the language in Body is more informative and general in comparison with the language used in Fitness. Still, the messages sent out by the different articles are in majority of the respects similar. Both magazines are portraying body ideals who can be understand as extreme. In Body the message feels fairly straight, “Build bigger muscles and burn more fat”, whereas Fitness willingly use the concept of “wellness” as a cover for what the message really is, namely “get your self a rock hard body through dieting and hard training”!
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Background: Linkage mapping is used to identify genomic regions affecting the expression of complex traits. However, when experimental crosses such as F2 populations or backcrosses are used to map regions containing a Quantitative Trait Locus (QTL), the size of the regions identified remains quite large, i.e. 10 or more Mb. Thus, other experimental strategies are needed to refine the QTL locations. Advanced Intercross Lines (AIL) are produced by repeated intercrossing of F2 animals and successive generations, which decrease linkage disequilibrium in a controlled manner. Although this approach is seen as promising, both to replicate QTL analyses and fine-map QTL, only a few AIL datasets, all originating from inbred founders, have been reported in the literature. Methods: We have produced a nine-generation AIL pedigree (n = 1529) from two outbred chicken lines divergently selected for body weight at eight weeks of age. All animals were weighed at eight weeks of age and genotyped for SNP located in nine genomic regions where significant or suggestive QTL had previously been detected in the F2 population. In parallel, we have developed a novel strategy to analyse the data that uses both genotype and pedigree information of all AIL individuals to replicate the detection of and fine-map QTL affecting juvenile body weight. Results: Five of the nine QTL detected with the original F2 population were confirmed and fine-mapped with the AIL, while for the remaining four, only suggestive evidence of their existence was obtained. All original QTL were confirmed as a single locus, except for one, which split into two linked QTL. Conclusions: Our results indicate that many of the QTL, which are genome-wide significant or suggestive in the analyses of large intercross populations, are true effects that can be replicated and fine-mapped using AIL. Key factors for success are the use of large populations and powerful statistical tools. Moreover, we believe that the statistical methods we have developed to efficiently study outbred AIL populations will increase the number of organisms for which in-depth complex traits can be analyzed.
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Obesity is heritable and predisposes to many diseases. To understand the genetic basis of obesity better, here we conduct a genome-wide association study and Metabochip meta-analysis of body mass index (BMI), a measure commonly used to define obesity and assess adiposity, in upto 339,224 individuals. This analysis identifies 97 BMI-associated loci (P < 5 x 10(-8)), 56 of which are novel. Five loci demonstrate clear evidence of several independent association signals, and many loci have significant effects on other metabolic phenotypes. The 97 loci account for similar to 2.7% of BMI variation, and genome-wide estimates suggest that common variation accounts for >20% of BMI variation. Pathway analyses provide strong support for a role of the central nervous systemin obesity susceptibility and implicate new genes and pathways, including those related to synaptic function, glutamate signalling, insulin secretion/action, energy metabolism, lipid biology and adipogenesis.
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The aim of this project is to provide an explanation for recently obtained binding constants for two similar guest molecules, NDMG and N-MAP, with a p-sulfonatocalix[6]arene host in ammonium acetate buffer. This work was done primarily using pressure perturbation calorimetry, which is a technique that determines the coefficient of thermal expansion, α, which is in turn related to the solute molecule's effect on the order of the surrounding water molecules. A series of experiments were designed to test the effects of suspected confounding variables on the validity of PPC data. PPC was then used to study NDMG and N-MAP in ammonium acetate buffer. NDMG exhibited a minimum in α as function of temperature, while N-MAP did not. This difference was theorized to be due to the formation of an intramolecular hydrogen bond in monocationic NDMG that would lower the heat capacity of the molecule and better distribute the molecule's charge. Computational work and nuclear magnetic resonance spectroscopy confirmed that monocationic, ring-closed NDMG has less concentrated charge and more constrained motion than monocationic, ring-open NDMG. This evidence supports the theory that monocationic NDMG forms an intramolecular hydrogen bond and that this may be responsible for the minimum in α. This difference may explain the differences in binding constants between NDMG and N-MAP.
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O tema Gestão sob o enfoque holístico surgiu a partir de uma leitura da revista HSM Management de setembro-outubro/2000. O artigo abordava o novo paradigma de gerenciar funcionários, que privilegia a busca do bem-estar, onde muitas empresas estão sendo obrigadas a revisar suas políticas de recursos humanos para enfocar as três dimensões de um indivíduo - corpo, mente e espírito. Segundo a reportagem, pesquisas da PricewaterhouseCoopers, Universum e outras organizações constataram que o equilíbrio trabalho/vida não é apenas uma demanda dos atuais empregados, mas também uma das principais prioridades dos formandos em universidades do mundo todo. A intensa luta para atrair funcionários de alto gabarito colocará a empresa com abordagem mais holística um degrau acima de suas concorrentes. Para as empresas, atender as verdadeiras necessidades individuais de seus funcionários é um novo paradigma na maneira de gerenciar seus negócios. O que mudou é a percepção de que o ser humano é fator primordial de competitividade e deixou de ser insumo. O ser humano passou a ser tendencialmente o centro, o foco das relações. Ainda que este conceito aparente estar longe da realidade organizacional brasileira, em função da distância entre o discurso e a prática de um modelo de gestão que considere o funcionário como um ser integral, já temos exemplos de empresas que estão adotando este princípio. A necessidade do equilíbrio entre os aspectos físico, mental, emocional e espiritual para ser feliz, tem levado as pessoas a superarem o medo do desconhecido e caminhar com detenninação em direção ao autodesenvolvimento. Este estudo analisou a utilização da gestão sob o enfoque holístico em duas diferentes empresas. Os resultados evidenciaram que a abordagem holística não está no âmbito da utopia, antes trata-se de um desafio para os gestores das organizações que, para um sucesso na adoção desta prática, precisam, mais do que implantá-la, adotá-la como filosofia de vida, incorporando-a a seus valores e visão de mundo. A prática cotidiana do modelo de gestão holística a partir do corpo diretivo é que vai possibilitar a verdadeira transformação da cultura organizacional tradicional para uma cultura organizacional holística, cuja conseqüência é o reflexo positivo nos resultados econômico-financeiros. C onstatamos, por outro lado, as limitações na utilização desse modelo de gestão tanto por parte dos funcionários quanto por parte dos altos executivos. Quanto aos funcionários, nem todos estão preparados para assumir novas responsabilidades ou preparados para o seu desenvolvimento pessoal, através do auto conhecimento. As crenças adquiridas no período educacional, tanto no lar quanto na escola, bem como suas recentes experiências profissionais podem inibir a descoberta de novas possibilidades, até que se sintam compelidos a lidar com os novos conhecimentos por necessidade de empregabilidade. Quanto aos executivos, por se tratar de um modelo de gestão relativamente novo, sem comprovação científica aliado à dificuldade de encontrar instrumentos de medição objetivos e ao elevado nível de exigência quanto a resultados crescentes no curto prazo, acabam priorizando a administração por objetivos, por se sentirem mais confortáveis quanto à certeza de obtenção de resultados econômico-financeiros no curto prazo. Esquecem-se, no entanto, dos efeitos desastrosos no clima organizacional, que vão comprometer os resultados de médio e longo prazos, seja pela possibilidade de elevado turnover como pela desmotivação generalizada, onde os funcionários só trabalham sob pressão. Por sua vez, cientes da importância do ser humano no novo cenário de elevada competitividade, não são poucos os empresários que já estão começando a trabalhar seus valores intrinsecos com a ajuda de terapeutas, filósofos, psicólogos, estimulando primeiro o auto conhecimento pessoal, para que possam futuramente empreender essa nova maneira de ver o mundo em suas respectivas empresas.
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o presente estudo procura trazer ao saber administrativo uma nova perspectiva, ao evidenciar a natureza parcial e instrumental das teorias organizacionais até então desenvolvidas. Ao buscar introduzir a percepção dos valores no estudo da administração, procura-se fazê-lo sob a ótica dos indivíduos, enfatizando-se o seu ponto de vista. Neste ensaio, a administração é concebida como ciência social não neutra, que tem reproduzido, no ambiente organizacional, os valores do sistema. Na medida em que os diversos arcabouços teóricos se desenvolveram, variadas e cada vez mais complexas foram as formas por intermédio das quais as teorias organizacionais procuraram submeter os indivíduos às necessidades produtivas. Teria a administração se distanciado, tanto de sua razão de ser, o indivíduo, como das grandes discussões desse final de milênio. Ter-se-ia tornado técnica, direcionando-se para o atendimento das demandas organizacionais, entendendo o homem como mero agente produtivo. Para a compreensão dessa feição das teorias organizacionais, o presente estudo lança mão da Teoria Crítica, que é uma proposta de visão do meio social, transpondo seus pressupostos para o domínio organizacional, no intuito de evidenciar os valores das diversas teorias e a caracterização do homem que cada uma delas promoveu. Na busca do entendimento das dificuldades existentes para que outros valores sejam percebidos pela administração, já que no universo consciente os valores do sistema tornaram-se hegemônicos, recorre-se aos ensinamentos de Carl Gustav Jung e suas definições de inconsciente pessoal e coletivo. Em seguida, tratou-se de contextualizar e associar às idéias previamente desenvolvidas sobre valores e teorias organizacionais o universo no qual desenvolveuse a pesquisa de campo, as Forças Armadas Brasileiras. Por fim, a pesquisa de campo desenvolvida constituiu reforço do que, até então, tinha-se procurado deixar evidente: que as teorias organizacionais têm privilegiado outros valores, que não os do indivíduo, que existe outra forma de se ver a realidade, mais substantiva e que, embora a administração tenha-se esforçado, pelo menos ao nível do discurso, para atender às demandas básicas do indivíduo no contexto organizacional, não obteve êxito. A nova perspectiva de que trata o presente estudo refere-se ao entendimento de que existem outros valores, que não os organizacionais, que precisam ser percebidos pelo saber administrativo. Procura-se alertar o corpo teórico quanto ao papel social que incumbe à administração e propõe-se que ela se afaste da instrumentalidade e se aproxime da substantividade, visão de mundo sempre possível e tantas vezes negligenciada por ela e por outras ciências auto-denominadas sociais.
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Muitas transformações são esperadas por causa das mudanças do clima, especialmente das atividades agrícolas realizadas nos trópicos. Esta tese centra-se em dois aspectos. O primeiro deles é o de reunir o conhecimento de sistemas silvipastoris; este ponto de vista estabelece a importância de solos tropicais e sua gestão adequada de acordo com as normas ambientais e sustentáveis. A segunda parte da tese é a aplicação desses princípios em um caso específico: a fazenda "El Paraíso". O objetivo central ou problema a resolver da segunda parte é propor um projeto para melhorar as atividades de produção de carne e, ao mesmo tempo, ajudar a preservar e melhorar o meio ambiente e especialmente os ecossistemas tropicais. A metodologia utilizada na tese foi buscar e analisar informações sobre o assunto. Depois disso, a investigação experimental e de campo foi realizada para levantar o projeto que combinaria as duas partes da obra. No final, com a informação recolhida uma proposta de projeto foi feita. O objetivo era propor a transformação dos processos de produção na fazenda selecionada. Logo de desenvolver e apresentar o projeto, foram analisadas as possibilidades de implementação do projeto. A conclusão do estudo foi o de apresentar e discutir três cenários possíveis após a implementação. Finalmente, a conclusão geral apresenta as realizações, as oportunidades e possíveis expansões futuras do projeto.
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In theory say the education as a knot of meanings made in the body. We take as a reference for demonstration of this argument the shows Folguedos, Guarnicê and Flor do Lírio and built within such spectacles cultural, symbolic and aesthetic meanings, which reveal the education woven in the body. Education that can happen not only in the formal space like the classroom or the university, but also in the area of art and the inclusion of individuals in the world of culture. So during the construction of the thesis we reflect on the following issues: what is the construction of culture and art that have in the Parafolclórico group? What way theses shows in their buildings bring significant elements that might compose an educational activity. How objectives sought asking the dichotomies present in the concepts of art and culture; critically systematize a work of artistic, cultural and educational production in the group, in addition to expanding the understanding of education, considering the body experiences. The phenomenological attitude of Merleau-Ponty, is a reference methodology of this study, which places the reference knowledge as a result of our experience in the world, our world lived. Thus, this study considers the experience of the researcher in the three shows in tariff, represented by scenes described, as a dancer and spectator. Therefore we understand that Folguedos, Guarnicê and Flor do Lírio in their artistic, aesthetic and cultural languages, allow many meanings that occur in the body, which invites the perception and extend the experience of the subject, demonstrating an education that allows sight and knowledge, seeking new sensations and experiences, we show our intimacy with the world, with the objects and with the other. The art is understood as virtuality, as a human creation that carries the reality and that allows many readings and experiences, each perception can recognize and know new horizons, having as base and material the culture. This entails the heterogeneous, is not closed but that individuals can interpret it entered and recognize the symbols they created the same way, confirming a unit. The art and culture show us significant evidences of an education woven in the body
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This body of work aims to describe and analyze the behavior of the Aí specificity marker of indefinite Noun Phrases (NP), one of the many functions this linguistic item is developing in contemporary Brazilian Portuguese. From the Functional Linguistic theory perspective, the North American declivity, this project intends to outline the possible grammaticalization trajectory taken by the Aí specificity marker. It will be followed from its function as a spatial deitic up to its integration of indefinite NP, and the action of the fundamental principles of the theory, such as iconicity and informativity, will be observed on the use of this item. Following this, Aí specificity marker behavior will be described in respect to various linguistic and social factors: type of text where the occurrence is encountered, language modality in which the latter is produced, syntactic function developed by the NP specified by Aí , the existence or lack of material intervening between Aí and the NP nuclear noun, informational status of the NP adjugated to Aí , and finally, sex, education and age of the speaker. The occurrence of conversational implicatures will also be verified (GRICE, 1982) within the contexts of Aí specificity marker use. Reflections on the teaching of grammar will be made, as well as on the possibility and validity of working with noun phrase specificity markers in elementary and high school Portuguese language classes. The data used in this research project stem from Corpus Discurso & Gramática A língua falada e escrita na cidade do Natal (FURTADO DA CUNHA, 1998), and from Corpus Discurso & Gramática A língua falada e escrita na cidade do Rio de Janeiro (VOTRE; OLIVEIRA, 1995)
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In this dissertation, we analyze, in a comparative perspective, the link between the short stories: Dama da Noite‟ and O Rapaz mais triste do mundo‟, of Caio Fernando Abreu. In order to reveal, analyze and establish relevant dialogues with Queer Theory, it‟s important, above all, make a misreading guided in the discursive contextuality of postmodern literature. In order to justify and clarify the many issues that arises in the emblematic relationships of characters that are present in the text and in the cultural context, historically and socially. It also highlights the utterance comparative value identified in the works, given the peculiarities of each one of them, not being possible to classify them as `figures of language` with which the comparison can be cited as an example. In this case, they serve to inspire the ways that may lead us to a better understanding of the parallels created between a world of the binary value and adjectives suggested by society and so well portrayed in the ideas and writings of Caio Fernando Abreu
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The recent astronomical observations indicate that the universe has null spatial curvature, is accelerating and its matter-energy content is composed by circa 30% of matter (baryons + dark matter) and 70% of dark energy, a relativistic component with negative pressure. However, in order to built more realistic models it is necessary to consider the evolution of small density perturbations for explaining the richness of observed structures in the scale of galaxies and clusters of galaxies. The structure formation process was pioneering described by Press and Schechter (PS) in 1974, by means of the galaxy cluster mass function. The PS formalism establishes a Gaussian distribution for the primordial density perturbation field. Besides a serious normalization problem, such an approach does not explain the recent cluster X-ray data, and it is also in disagreement with the most up-to-date computational simulations. In this thesis, we discuss several applications of the nonextensive q-statistics (non-Gaussian), proposed in 1988 by C. Tsallis, with special emphasis in the cosmological process of the large structure formation. Initially, we investigate the statistics of the primordial fluctuation field of the density contrast, since the most recent data from the Wilkinson Microwave Anisotropy Probe (WMAP) indicates a deviation from gaussianity. We assume that such deviations may be described by the nonextensive statistics, because it reduces to the Gaussian distribution in the limit of the free parameter q = 1, thereby allowing a direct comparison with the standard theory. We study its application for a galaxy cluster catalog based on the ROSAT All-Sky Survey (hereafter HIFLUGCS). We conclude that the standard Gaussian model applied to HIFLUGCS does not agree with the most recent data independently obtained by WMAP. Using the nonextensive statistics, we obtain values much more aligned with WMAP results. We also demonstrate that the Burr distribution corrects the normalization problem. The cluster mass function formalism was also investigated in the presence of the dark energy. In this case, constraints over several cosmic parameters was also obtained. The nonextensive statistics was implemented yet in 2 distinct problems: (i) the plasma probe and (ii) in the Bremsstrahlung radiation description (the primary radiation from X-ray clusters); a problem of considerable interest in astrophysics. In another line of development, by using supernova data and the gas mass fraction from galaxy clusters, we discuss a redshift variation of the equation of state parameter, by considering two distinct expansions. An interesting aspect of this work is that the results do not need a prior in the mass parameter, as usually occurs in analyzes involving only supernovae data.Finally, we obtain a new estimate of the Hubble parameter, through a joint analysis involving the Sunyaev-Zeldovich effect (SZE), the X-ray data from galaxy clusters and the baryon acoustic oscillations. We show that the degeneracy of the observational data with respect to the mass parameter is broken when the signature of the baryon acoustic oscillations as given by the Sloan Digital Sky Survey (SDSS) catalog is considered. Our analysis, based on the SZE/X-ray data for a sample of 25 galaxy clusters with triaxial morphology, yields a Hubble parameter in good agreement with the independent studies, provided by the Hubble Space Telescope project and the recent estimates of the WMAP