O comportamento do escoamento supersônico no interior de bocais convergente-divergente retangulares é investigado numericamente, comparando-se quatro bocais com diferentes seções divergentes, com a mesma razão de aspecto AR=1.14 e mesma relação áreas da saída e da garganta dos bocais NAR=1.43. Os bocais são submetidos a diferentes pressões de admissão do fluido de trabalho, mantendo-se a relação entre a pressão de admissão e de descarga constante NPR=5. As simulações consideram o escoamento em regime permanente, compressível, viscoso, com abordagem baseada na massa específica (abordagem acoplada) , juntamente com o modelo de turbulência − /SST. A qualidade dos resultados é medida empregando-se três níveis de refino da discretização do domínio computacional, observandose a ordem de convergência e o índice de convergência de malhas GCI. Os resultados numéricos mostram que o número de Mach e a temperatura do fluido de trabalho independem da pressão de admissão, ao contrário do comportamento da pressão local e da massa específica. As propriedades do escoamento são fortemente dependentes da variação da geometria, e a variação do ângulo da seção divergente provoca uma mudança direta do número de Mach e inversa da pressão, da temperatura e da massa específica do escoamento no interior dessa seção. As simulações são comparadas com os resultados da teoria isentrópica e mostram que a linha sônica é deslocada do centro geométrico da garganta dos bocais para cada geometria simulada. A comparação com a teoria e com dados experimentais mostra desvios inferiores a 6x10-3 %. O uso do modelo de turbulência − / SST é capaz de resolver o escoamento com boa precisão, prevendo bem seu perfil de velocidades, as ondas de expansão de Prandtl-Meyer, juntamente com as interações dessas ondas com a camada limite. / The behavior of the supersonic flow inside rectangular convergent-divergent nozzle is investigated numerically by comparing four nozzles with different divergent sections, with a common aspect ratio AR=1.14, and the same nozzle exit-to-throat area ratios NAR=1.43. Nozzles are subject to several working fluid inlet pressures, maintaining a constant pressure ratio NPR=5. Simulations assume the flow in steady state, compressible, viscous, using a coupled approach with the turbulence model − /SST. The quality of results is measured by employing three refining levels of the computational domain discretization, observing the order of convergence and the grid convergence index GCI. Numerical results show that the Mach number and the temperature of the working fluid are independent of the inlet pressure, unlike the behavior of local pressure and the density. Flow properties are strongly dependent on the geometry variation, and the change on the angle of divergent section causes a direct effect on the Mach number and inverse on the pressure, the temperature and the density of the flow in this section. Simulations are compared to the results of the isentropic theory and show that the sonic line is offset from the geometric center of the throat nozzle, for each simulated geometry. Results from this work are compared to experimental and theoretical data and show deviations below 6x10-3 %. The − / SST turbulence model is able to solve the flow with good accuracy, and predicts its velocity profile, Prandtl-Meyer expansion waves, and their interactions with the boundary layer.

A necessidade constante de desenvolvimento de competências individuais e organizacionais atrelada a projetos de educação a distância (EAD) expande a possibilidade de acesso a programas de treinamento, formação e qualificação profissionais ofertados por instituições de ensino superior (IES) e outras organizações do sistema produtivo. Nota-se um grande progresso tecnológico cada vez mais disseminado no recente campo da EAD. Porém, essa modalidade de ensino é muito carente de estudos sistemáticos. Variáveis relacionadas ao perfil da clientela necessitam ser mais investigadas, como é o caso dos Estilos de Aprendizagem, que necessita de uma definição mais apurada, especialmente para garantir a qualidade dos instrumentos que se propõem a medir esse construto. Muitas vezes o seu conceito está relacionado com o conceito de Estratégias de Aprendizagem, sem grandes diferenciações entre eles. Além disso, a literatura indica que tais variáveis de características da clientela podem estar relacionadas com a Evasão em cursos na modalidade EAD. Nesse sentido, a presente pesquisa objetivou construir e verificar evidências de validade de um instrumento de medida de Estilos de Aprendizagem, bem como realizar a validade convergente com o instrumento de Estratégias de Aprendizagem, além de propor uma discussão conceitual acerca dos Estilos de Aprendizagem. Ao final desse estudo, o instrumento de Estilos de Aprendizagem foi construído, passou por validação semântica, por juízes e foram verificadas evidências de validade estatística. Foi demonstrado também que os alunos que fizeram mais uso das Estratégias de Aprendizagem Autorregulatórias, bem como das Estratégias Comportamentais e valorizam mais os aspectos do ambiente no quais realiza os seus estudos (ou seja, possuem mais Preferências Ambientais) tendem a não abandonar o curso. A validação convergente entre os instrumentos de Estilos de Aprendizagem e Estratégias de Aprendizagem demonstraram que os instrumentos refletem o histórico de relacionamento entre esses conceitos. Muitos fatores de Estratégias de Aprendizagem se relacionam com o instrumento de Estilos de Aprendizagem. Os resultados também possibilitaram uma definição operacional de Estilos de Aprendizagem no campo da Psicologia Organizacional e do Trabalho (POT). Para pesquisas futuras, recomenda-se o uso de técnicas estatísticas mais robustas, como o uso de Análise Fatorial Confirmatória, bem como a Modelagem de Equações Estruturais, que poderiam mensurar com maior exatidão o quanto os Estilos e as Estratégias de Aprendizagem influenciam a Evasão em Ações Educacionais Ofertadas a Distância em contexto de IES. / The constant need to develop individual and organizational competences linked to e-learning projects expands the possibility of access to professional training and qualification programs offered by higher education institutions (HEIs) and other organizations of the productive system. A great technological progress is becoming increasingly widespread in this recent e-learning field. However, this type of education is very lacking in systematic studies. Variables related to the customer profile needs to be further investigated, like the Learning Styles variable. This last requires a more precise definition, especially to ensure the quality of the instruments used to measure this construct. The Learning Styles concept is often related to the Strategy Styles concept without mentioning the proper differences between them. Besides that, the literature indicates that such costumers characteristics variables may be related to the Evasion in e-learning courses. This research aimed to carry out the conceptual analysis of Learning Styles through the construction and verification of validity evidence of a measuring instrument and the convergent validity with Learning Strategies. The Learning Styles instrument was built, underwent semantic validation by judges and evidence of statistical validity were verified. It was also shown that students who made more use of Self-Regulatory Learning Strategies, as well as Behavioral Strategies and value the aspects of the environment in which they realize its studies (ie, have more Environmental Preferences) tend not to leave the course. The convergent validity between Learning Styles and Learning Strategies instruments showed that the instruments reflect the historical relationship between these concepts. Many aspects of Learning Strategies are also related to the Learning Styles aspects. The results showed an adequate definition of Learning Styles in the field of Organizational and Work Psychology (OWP). For future research, it is recommending the use of more consistent statistical techniques such the Confirmatory Factor Analysis as well as Structural Equation Modeling, which could measure more accurately how the Styles and Learning Strategies influence the Evasion in e-learning in the higher education institutions context.

As plantas têm diversos modos de resolver problemas como a escassez de recursos, o ataque de herbívoros ou a perda de água. O modo como uma planta resolve um desses problemas pode ser considerado uma tática e o conjunto dessas táticas constitui uma estratégia ecológica. As estratégias só são possíveis porque as plantas têm uma série de atributos que têm um efeito direto no desempenho ecológico dessas plantas. Esses atributos funcionais, portanto, refletem as estratégias ecológicas das espécies. Com base nessa lógica, descrevemos as 157 espécies de árvore dominantes de uma floresta de terra firme da Amazônia Central segundo treze atributos funcionais (foliares, vegetativos e regenerativos). Nosso objetivo era descomplicar a ecologia de florestas tropicais, até então muito focada na identidade das espécies. Como essas florestas têm muitas espécies e a densidade dessas espécies é muito baixa, os padrões de composição de espécies das comunidades são muito complexos e pouco claros. Com a mudança do foco para a diversidade de estratégias, conseguimos desvendar um padrão interessante de dominância de tipos de estratégia: apesar de haver onze tipos diferentes na floresta estudada, 61% das espécies são de um só tipo. Além de ter o maior número de espécies, o tipo 1 respondeu por 52% da biomassa vegetal da floresta, o que indica que essa é a estratégia ótima. No entanto, como a dominância relativa não varia muito entre as espécies, é possível que o benefício gerado pela adoção da estratégia ótima seja compensado pelo número de espécies que adotam essa estratégia. Concluímos que os padrões encontrados na distribuição das dominâncias entre as espécies e entre os tipos são resultado principalmente das peculiaridades do conjunto de espécies, em especial a grande quantidade de espécies dos tipos 1 e 2. Mas como tantas espécies parecidas podem ter se originado? Para responder essa pergunta, testamos três hipóteses: 1) a taxa de especiação foi maior do que a taxa de divergência ecológica; 2) as espécies convergiram recentemente ou evoluíram paralelamente; e 3) razões alométricas ou demandas conflitantes entre os atributos restringiram a diversidade de estratégias. Encontramos evidências parciais que corroboram essas três hipóteses. Como a diversidade filogenética foi menor do que a diversidade ecológica, as espécies estudadas podem ser fruto de especiação recente, o que é compatível com a teoria dos refúgios. Segundo essa teoria, as espécies teriam se formado em refúgios do Pleistoceno durante as glaciações, o que deve ter proporcionado altas taxas de especiação alopátrica, não necessariamente acompanhada por divergência ecológica. Por outro lado, o efeito positivo do sinal filogenético na diversidade de estratégias revela que os antepassados das espécies atuais eram mais diferentes entre si do que as espécies atuais. Isso indica que houve uma convergência recente de estratégias, o que está de acordo com a hipótese do Lago Amazonas, que cobriu a área estudada até o início do Pleistoceno. O solo rico em silte da área estudada reforça a suspeita de que o leito desse lago deve ter fornecido uma ótima oportunidade ecológica para as espécies de terra firme. Finalmente, encontramos evidência de que a diversidade das estratégias ligadas aos atributos foliares é severamente limitada por demandas conflitantes e razões alométricas. / Plants have several ways to solve their problems such as resource limitation, herbivory damage or water loss. How a plant solves one of these problems can be considered a tactic and all the tactics together constitutes an ecological strategy. The strategies are possible only because plants have a series of traits that directly affect ecological performance of these plants. These functional traits, therefore, reflect the ecological strategies of species. Based on this rationale, we described the 157 dominant tree species in a terra firme forest of Central Amazon according to thirteen functional traits (among leaf, vegetative and regenerative traits). Our goal was to simplify the ecology of tropical forests, so far focused on species identity. Since these forests have a lot of species that are in general very rare, the patterns of species composition of these communities are very complex and unclear. By shifting focus to diversity of strategies, instead identities, we unveiled an interesting pattern of dominance among the strategy types: Although there are eleven different types of strategies in the forest studied, 61% of the species were of only one type. In addition to a greater number of species, only one type responded by 52% of the tree biomass of the forest sampled, which indicates that this is the optimal strategy. However, as the dominance does not vary considerably between species, it is possible that the benefit generated by the use of the optimal strategy is offset by the number of species who also use this strategy. We conclude that the neutral pattern found in the distribution of dominances among species and the dominance pattern found among the types are mainly the result of peculiarities of the species set, in particular the large number of the two most common strategies. But how so many similar species can have been originated? To answer to this question, we tested three hypotheses: 1) the rate of speciation was greater than the rate of ecological divergence; 2) species converged recently or evolved parallelly; and 3) allometric relations or tradeoffs between traits restricted the diversity of strategies. We found evidences that partially support these three hypotheses. As phylogenetic diversity was lower than ecological diversity, it is possible that the species studied resulted from recent speciation, which is compatible with the refuge theory. According to this theory, several species would have originated in Pleistocene refuges during the glaciations, which might have enhanced rates of allopatric speciation that was not necessarily followed by ecological divergence. On the other hand, the positive effect of phylogenetic signal in strategy diversity reveals that current species ancestors were ecologically more different from each other than current species are. This indicates that there was a recent convergence of strategies, which is consistent with the hypothesis of Lake Amazonas, which covered the area studied until the early Pleistocene. The large relative amount of silt in the soil of the studied area strengthens the suspect that the bed of this Lake should have provided a great ecological opportunity for species that were adapted to drier and poorer soils. Finally, we found evidence that only the diversity of strategies linked to leaf traits is severely limited by tradeoffs and allometric relations.

Advances in the elaboration of vaccines and enzyme inhibitors rely on acquiring more knowledge about protein-carbohydrate binding events. Furthermore, the relationships between biological function and the three-dimensional properties of large glycans can be studied by focusing on the structural components they contained, namely, by scaling down the system under analysis. Chemical methods are useful assets as they allow the isolation and determination of epitopes; these small and recognizable fragments that lead to very specific interactions. In this thesis, biologically relevant saccharides were obtained using recently developed concepts in carbohydrate synthesis and NMR spectroscopy was used to unravel their conformational preferences. In paper I, the convergent synthesis of the tetrasaccharide found in the natural product solaradixine is described. Reactivity enhanced disaccharide glycosyl donors were coupled to a disaccharide acceptor in a 2 + 2 fashion. The computer program CASPER was subsequently used to verify the synthesized structure. The conformation arming concept employed in paper I was further investigated in paper II. An NMR-based methodology enabled the determination of the ring conformations of a set of donors. Subsequently, glycosylation reactions were performed and yields were correlated to donors ring shapes. Perturbations in the rings shape caused by bulky silyl ether protective groups were sufficient to boost the potency of several donors. As a matter of fact, complex branched oligosaccharides could be obtained in good to excellent yields. In paper III, NMR spectroscopy observables were measured to elucidate the ring shape, the mutual orientation of the rings across the glycosidic bond and the positions of the side chains of 5 trisaccharides found in larger structures. With the aid of molecular dynamics simulations, their overall conformational propensities were revealed. Finally, the software CASPER prediction skills were improved by adding, inter alia, NMR information of synthesized mono- and disaccharides to its database. Unassigned chemical shifts from polysaccharides served as input to challenge its ability to solve large carbohydrate structures. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 4: Manuscript.</p>

This thesis deals with the system of human resource management in international companies. The theoretical part is focused on the concept of international human resource management basic methods and trends and techniques of human resource management in international corporations. The practical part is devoted to analyze the current state of human resources management in ADP Employer Services Ceska republika a.s. the daughter company of international organization ADP Inc. Based on my practical research: employees survey and personal interview with the local HR Business Partner Lead I will evaluate the current state of human resource management system in the company and make series of recommendations that will help to improve the system of human resources for ADPs branch in Czech Republic which is the main contribution of this thesis.

Thesis deals with leasing financing in light of Czech national regulations and IFRS. At first part it applies to lease at common level, its historical development, advantages and disadvantages and also its division. Second part targets the legal regulations in the Czech Republic, including tax and accounting view. Third part deals with IFRS adjustment, some distinctions from US GAAP, convergent project of IASB and FASB and discussion paper Leases: preliminary views. The work is completed by the practical application aimed at comparison Czech national regulations and IFRS in case of the financial leasing.

Purpose of this work is to describe long-termed tangible assets in compliance with IFRS and U.S. GAAP and compare their individual elements using financial statements of The Coca-Cola Company and Coca-Cola HBC. Part of this work will focus on ongoing convergent process. Specifity of agriculture (IAS 41) is not an object of this work.

A ecomorfologia apresenta diferentes ramos, sendo a ecomorfologia comparada o ramo proposto neste trabalho, qual segue a análise das estruturas convergentes dos representantes das famílias africana Pantodontidae e neotropical Gasteropelecidae. Para tal, são analisadas e discutidas as pressões seletivas exercidas pelos ambientes muito similares encontrados nos pequenos córregos e igarapés localizados no interior da Floresta do Congo e Floresta Amazônica, onde vivem respectivamente as espécies africanas e neotropicais. Assim, foi possível identificar uma forte convergência adaptativa na musculatura das nadadeiras peitorais, uma vez que são adaptações aos saltos de longo alcance para fora dágua, característicos de todas as espécies analisadas, tratadas em conjunto por peixes-borboleta de água doce (Weist, 1995; Saidel et al., 2003). / The ecomorphology studies present different fields. The Comparative Ecomorphology, the field suggested at this work, follows the analyses of convergent structures found among Pantodontidae african families and Gasteropelecidae neotropical families. Due to that, we evaluated the selective pressures from similar aquatic environments, such as streams and small rivers. The analyses of african and neotropical species were done in relation to the Congo and Amazon Forest areas, respectively. In this context, we identified strong adaptive convergence in the musculature associated to the pectoral fins. These adaptations are related, in both studied cases, to the ability to jump long distandes out of the water (Weist, 1995; Saidel et al., 2003).

Understanding the nature of adaptive evolution has been the recent focus of research detailing the genetic basis of adaptation and theoretical work describing the mechanics of adaptive evolution. Nevertheless, key questions regarding the process of adaptive evolution remain. Ultimately, a detailed description of the ecological context, evolutionary history, and genetic basis of adaptations is required to advance our understanding of adaptive evolution. To address some of the contemporary issues surrounding adaptive evolution, I examine phenotypic and genotypic changes in a snake feeding adaptation. Adaptations can arise through fixation of novel mutations or recruitment of existing variation. Some populations of the garter snakes Thamnophis sirtalis, T. couchii, and T. atratus possess elevated resistance to tetrodotoxin (TTX), the lethal toxin of their newt prey. I show that TTX resistance has evolved independently through amino acid changes at critical sites in a voltage-gated sodium channel protein (Nav1.4) targeted by TTX. Thus, adaptive evolution has occurred multiple times in garter snakes via de novo acquisition of beneficial mutations. Detailing the genetic basis of adaptive variation in natural populations is the first step towards understanding the tempo and mode of adaptive evolution. I evaluate the contribution of Nav1.4 alleles to TTX resistance in two garter snake species from central coastal California. Allelic variation in Nav1.4 explains 29% and 98% of the variation in TTX resistance in T. atratus and T. sirtalis, respectively, demonstrating that Nav1.4 is a major effect locus. The simple genetic architecture of TTX resistance in garter snakes may significantly impact the dynamics of trait change and coevolution. Patterns of convergent evolution are cited as some of the most compelling examples of the strength of natural selection in shaping organismal diversity. Yet repeated patterns may tell us as much about the constraints that restrict evolution as about the importance of natural selection. I present data on convergent molecular adaptations in parallel arms races between diverse snakes and amphibians from across the globe. Six snake species that prey on TTX bearing amphibians have independently acquired amino acid changes in Nav1.4. The derived mutations are clustered in two portions of the gene, often involving the same sites and substitutions. While a number of amino acid changes can make Nav1.4 insensitive to TTX, most of these negatively impact or abolish the ion-conducting function of the protein. Thus, intramolecular pleiotropy likely prevents most replacements from becoming fixed and imposes limits on protein evolution.

No description available.