Traditional file access interfaces rely on ubiquitous transports that impose severe restrictions on performance and prove insufficient for adaptation to parallel Input/Output (I/O). Remote Direct Memory Access based (RDMA-based) approaches are aimed at moving data between different process address spaces with streamlined mediation and reduced involvement of the operating system using synchronization semantics that are different from ubiquitous transports. This thesis studies the adaptability of RDMA-based transports to parallel I/O. Combining RDMA semantics with parallel I/O leads to overhead reduction by overlapping communication and computation and by bandwidth enhancement. Although parallel I/O tends to increase latency in certain cases, use of RDMA techniques mitigate on this effect.

Introdução: O objetivo do estudo foi analisar a relação entre funções executivas e funcionalidade em uma amostra de idosos com diferentes graus de comprometimento cognitivo e caracterizar sua funcionalidade. O segundo objetivo deste estudo foi traduzir e adaptar culturalmente o instrumento Direct Assessment of Functional Status- revised (DAFS-R) para língua portuguesa (Brasil), avaliar as propriedades psicométricas do instrumento e caracterizar o perfil funcional de cada grupo diagnóstico. Estudos anteriores mostraram diferentes resultados entre avaliação objetiva e avaliação baseada em relatos de informantes sobre funcionalidade de um indivíduo. Neste estudo, foi comparada a avaliação funcional realizada através de medidas objetivas (teste de desempenho) e de julgamentos subjetivos (relatados por cuidadores). Métodos: 89 idosos (idade média de 73,8 anos) foram submetidos a avaliações clínica e neuropsicológica, e foram alocados em três grupos diagnósticos de acordo com nível cognitivo: controles (CO, n = 32), comprometimento cognitivo leve (CCL, n = 31) e doença de Alzheimer (DA, n = 26). As funções executivas foram avaliadas com o instrumento Executive Interview (EXIT25) e a funcionalidade foi medida objetivamente através da DAFS-BR. Resultados: Foi encontrada forte correlação negativa entre os escores da DAFS-BR e os escores da EXIT25 (r=- 0,872, p<0,001). A análise de regressão linear sugeriu uma influência significativa da EXIT-25 e do CAMCOG nos resultados da DAFS-BR. Médias significativamente diferentes foram observadas nos três diagnósticos em relação ao escore total da DAFS-BR. Os subdomínios da DAFS-BR capazes de diferenciar pacientes com CCL dos controles estavam relacionados às habilidades para lidar com dinheiro e de fazer compras. A adaptação transcultural mostrou boa consistência interna (alfa de Cronbach = 0,78), alta confiabilidade interavaliadores (0,996, p<0,001), bem como estabilidade teste-reteste ao longo do tempo (0,995, p <0,001). Correlação entre o escore total da DAFS-BR e do IQCODE foi significativa (r=-0,65, p<0,001). DAFSBR foi capaz de discriminar os grupos estudados (CO, CCL e DA). Análise da curva ROC sugeriu que DAFS-BR tem boa sensibilidade e especificidade para identificar com precisão pacientes com CCL, CO e DA. Conclusões: disfunção executiva está associada a pior capacidade de realizar atividades instrumentais da vida diária. Nesta amostra, os pacientes com CCL apresentaram pior estado funcional quando comparados aos controles. Pacientes com CCL podem apresentar alterações sutis no estado funcional, que somente são capturadas por medidas objetivas da funcionalidade. Resultados da adaptação transcultural e da avaliação das propriedades psicométricas sugerem que a DAFS-BR pode documentar diferentes graus de alterações do comprometimento funcional entre idosos brasileiros. Diagnósticos e tratamentos devem considerar estas diferenças entre métodos de avaliação funcional em vez de focar exclusivamente em relatos subjetivos de funcionalidade do paciente / Introduction: The objective of the study is to examine the association between executive functions and functional status in a cross section of older adults with varying degrees of cognitive impairment and characterize the functional status. The second objective of this study was to translate, culturally adapt the Direct Assessment of Functional Status- revised (DAFS-R) for Brazilian Portuguese (DAFS-BR), and to evaluate its reliability and validity to characterize the functional status in each diagnostic group. Previous studies show different results from objective assessment of functional abilities compared to information based on informants reports. In this study we compared perception of functional status between objective (performance test) e subjective (caregivers judgments) measures of assessment. Methods: 89 individuals (mean age 73.8 years) underwent clinical and neuropsychological evaluations, and were allocated into three diagnostic groups according to cognitive status: normal controls (NC, n=32), mild cognitive impairment (MCI, n=31) and mild Alzheimers disease (AD, n=26). Executive functions were assessed with the 25-item Executive Interview (EXIT25), and functional status was measured with the Brazilian version of the Direct Assessment of Functional Status test (DAFS-BR). Results: We found a robust negative correlation between the DAFS-R and the EXIT25 scores (r=-0.872, p<0.001). Linear regression analyses suggested a significant influence of the EXIT-25 and the CAMCOG on the DAFS-R scores. The DAFS-BR items that differentiated MCI from controls involved the ability to deal with finances and shopping skills. The results of cross-cultural adaptation, reliability and validity indicated good internal consistency (Cronbach´s alpha =0.78) in the total sample. DAFS-BR showed high inter-observer reliability (0.996; p<0.001) as well as test-retest stability over time (0.995; p<0.001). Correlation between the DAFS-BR total score and the IQCODE was moderate and significant (r=-0.65, p<0.001). Significantly different total DAFS-R scores were observed across the three diagnostic groups. The instrument was able to discriminate the studied groups (NC, MCI and AD). ROC curve analyses suggested that DAFS-BR has good sensitivity and specificity to identify MCI and DA from unimpaired controls. Conclusions: Executive dysfunction is associated with worse ability to undertake instrumental activities of the daily living. In this sample, patients with MCI showed worse functional status when compared to NC. MCI patients may show subtle changes in functional status that may only be captured by objective measures of ADLs. Results of cross-cultural adaptation, reliability and validity suggest DAFS-BR can document degrees of severity of functional impairment among Brazilian older adults. Diagnose and treatments should consider these discrepancies rather than focusing on subjective reports of patient functionality

Introdução: O objetivo do estudo foi analisar a relação entre funções executivas e funcionalidade em uma amostra de idosos com diferentes graus de comprometimento cognitivo e caracterizar sua funcionalidade. O segundo objetivo deste estudo foi traduzir e adaptar culturalmente o instrumento Direct Assessment of Functional Status- revised (DAFS-R) para língua portuguesa (Brasil), avaliar as propriedades psicométricas do instrumento e caracterizar o perfil funcional de cada grupo diagnóstico. Estudos anteriores mostraram diferentes resultados entre avaliação objetiva e avaliação baseada em relatos de informantes sobre funcionalidade de um indivíduo. Neste estudo, foi comparada a avaliação funcional realizada através de medidas objetivas (teste de desempenho) e de julgamentos subjetivos (relatados por cuidadores). Métodos: 89 idosos (idade média de 73,8 anos) foram submetidos a avaliações clínica e neuropsicológica, e foram alocados em três grupos diagnósticos de acordo com nível cognitivo: controles (CO, n = 32), comprometimento cognitivo leve (CCL, n = 31) e doença de Alzheimer (DA, n = 26). As funções executivas foram avaliadas com o instrumento Executive Interview (EXIT25) e a funcionalidade foi medida objetivamente através da DAFS-BR. Resultados: Foi encontrada forte correlação negativa entre os escores da DAFS-BR e os escores da EXIT25 (r=- 0,872, p<0,001). A análise de regressão linear sugeriu uma influência significativa da EXIT-25 e do CAMCOG nos resultados da DAFS-BR. Médias significativamente diferentes foram observadas nos três diagnósticos em relação ao escore total da DAFS-BR. Os subdomínios da DAFS-BR capazes de diferenciar pacientes com CCL dos controles estavam relacionados às habilidades para lidar com dinheiro e de fazer compras. A adaptação transcultural mostrou boa consistência interna (alfa de Cronbach = 0,78), alta confiabilidade interavaliadores (0,996, p<0,001), bem como estabilidade teste-reteste ao longo do tempo (0,995, p <0,001). Correlação entre o escore total da DAFS-BR e do IQCODE foi significativa (r=-0,65, p<0,001). DAFSBR foi capaz de discriminar os grupos estudados (CO, CCL e DA). Análise da curva ROC sugeriu que DAFS-BR tem boa sensibilidade e especificidade para identificar com precisão pacientes com CCL, CO e DA. Conclusões: disfunção executiva está associada a pior capacidade de realizar atividades instrumentais da vida diária. Nesta amostra, os pacientes com CCL apresentaram pior estado funcional quando comparados aos controles. Pacientes com CCL podem apresentar alterações sutis no estado funcional, que somente são capturadas por medidas objetivas da funcionalidade. Resultados da adaptação transcultural e da avaliação das propriedades psicométricas sugerem que a DAFS-BR pode documentar diferentes graus de alterações do comprometimento funcional entre idosos brasileiros. Diagnósticos e tratamentos devem considerar estas diferenças entre métodos de avaliação funcional em vez de focar exclusivamente em relatos subjetivos de funcionalidade do paciente / Introduction: The objective of the study is to examine the association between executive functions and functional status in a cross section of older adults with varying degrees of cognitive impairment and characterize the functional status. The second objective of this study was to translate, culturally adapt the Direct Assessment of Functional Status- revised (DAFS-R) for Brazilian Portuguese (DAFS-BR), and to evaluate its reliability and validity to characterize the functional status in each diagnostic group. Previous studies show different results from objective assessment of functional abilities compared to information based on informants reports. In this study we compared perception of functional status between objective (performance test) e subjective (caregivers judgments) measures of assessment. Methods: 89 individuals (mean age 73.8 years) underwent clinical and neuropsychological evaluations, and were allocated into three diagnostic groups according to cognitive status: normal controls (NC, n=32), mild cognitive impairment (MCI, n=31) and mild Alzheimers disease (AD, n=26). Executive functions were assessed with the 25-item Executive Interview (EXIT25), and functional status was measured with the Brazilian version of the Direct Assessment of Functional Status test (DAFS-BR). Results: We found a robust negative correlation between the DAFS-R and the EXIT25 scores (r=-0.872, p<0.001). Linear regression analyses suggested a significant influence of the EXIT-25 and the CAMCOG on the DAFS-R scores. The DAFS-BR items that differentiated MCI from controls involved the ability to deal with finances and shopping skills. The results of cross-cultural adaptation, reliability and validity indicated good internal consistency (Cronbach´s alpha =0.78) in the total sample. DAFS-BR showed high inter-observer reliability (0.996; p<0.001) as well as test-retest stability over time (0.995; p<0.001). Correlation between the DAFS-BR total score and the IQCODE was moderate and significant (r=-0.65, p<0.001). Significantly different total DAFS-R scores were observed across the three diagnostic groups. The instrument was able to discriminate the studied groups (NC, MCI and AD). ROC curve analyses suggested that DAFS-BR has good sensitivity and specificity to identify MCI and DA from unimpaired controls. Conclusions: Executive dysfunction is associated with worse ability to undertake instrumental activities of the daily living. In this sample, patients with MCI showed worse functional status when compared to NC. MCI patients may show subtle changes in functional status that may only be captured by objective measures of ADLs. Results of cross-cultural adaptation, reliability and validity suggest DAFS-BR can document degrees of severity of functional impairment among Brazilian older adults. Diagnose and treatments should consider these discrepancies rather than focusing on subjective reports of patient functionality

Owing to their versatile orbital character with both local and highly dispersive degrees of freedom, transition metal oxides span the range of ionic, covalent and metallic bonding. They exhibit a vast diversity of electronic phenomena such as high dielectric, piezoelectric, pyroelectric, ferroelectric, magnetic, multiferroic, catalytic, redox, and superconductive properties. The nature of these properties arises from sensitive details in the electronic structure, e.g. orbital mixing and orbital hybridization, due to non-stoichiometry, atomic displacements, broken symmetries etc., and their coupling with external perturbations. In the work presented here, these variations of the electronic structure of crystals due to structural and electronic defects have been investigated, exemplarily for the quasi-binary system SrO - SrTiO3 - TiO2. A number of binary and ternary structures have been studied, both experimentally as well as by means of electronic modeling. The applied methods comprise Resonant X-ray Scattering techniques like Diffraction Anomalous Fine Structure, Anisotropy of Anomalous Scattering and X-ray Absorption Fine Structure, and simultaneously extensive electronic calculations by means of Density Functional Theory and Finite Difference Method Near-Edge Structure to gain a thorough physical understanding of the underlying processes, interactions and dynamics. It is analyzed in detail how compositional variations, e.g. manifesting as oxygen vacancies or ordered stacking faults, alter the short-range order and affect the electronic structure, and how the severe changes in mechanical, optical, electrical as well as electrochemical properties evolve. Various symmetry-property relations have been concluded and interpreted on the basis of these modifications in electronic structure for the orbital structure in rutile TiO2, for distorted TiO6 octahedra and related switching mechanisms of the Ti valence, for elasticity and resistivity in strontium titanate, and for surface relaxations in Ruddlesden-Popper phases. Highlights of the thesis include in particular the methodical development regarding Resonant X-Ray Diffraction, such as the first use of partially forbidden reflections to get the complete phase information not only of the tensorial structure factor but of each individual atomic scattering tensor for a whole spectrum of energies, as well as the determination of orbital degrees of freedom and details of the partial local density of states from these tensors. On the material side, the most prominent results are the identification of the migration-induced field-stabilized polar phase and the exergonic redox behavior in SrTiO3 caused by defect migration and defect separation.

Owing to their versatile orbital character with both local and highly dispersive degrees of freedom, transition metal oxides span the range of ionic, covalent and metallic bonding. They exhibit a vast diversity of electronic phenomena such as high dielectric, piezoelectric, pyroelectric, ferroelectric, magnetic, multiferroic, catalytic, redox, and superconductive properties. The nature of these properties arises from sensitive details in the electronic structure, e.g. orbital mixing and orbital hybridization, due to non-stoichiometry, atomic displacements, broken symmetries etc., and their coupling with external perturbations. In the work presented here, these variations of the electronic structure of crystals due to structural and electronic defects have been investigated, exemplarily for the quasi-binary system SrO - SrTiO3 - TiO2. A number of binary and ternary structures have been studied, both experimentally as well as by means of electronic modeling. The applied methods comprise Resonant X-ray Scattering techniques like Diffraction Anomalous Fine Structure, Anisotropy of Anomalous Scattering and X-ray Absorption Fine Structure, and simultaneously extensive electronic calculations by means of Density Functional Theory and Finite Difference Method Near-Edge Structure to gain a thorough physical understanding of the underlying processes, interactions and dynamics. It is analyzed in detail how compositional variations, e.g. manifesting as oxygen vacancies or ordered stacking faults, alter the short-range order and affect the electronic structure, and how the severe changes in mechanical, optical, electrical as well as electrochemical properties evolve. Various symmetry-property relations have been concluded and interpreted on the basis of these modifications in electronic structure for the orbital structure in rutile TiO2, for distorted TiO6 octahedra and related switching mechanisms of the Ti valence, for elasticity and resistivity in strontium titanate, and for surface relaxations in Ruddlesden-Popper phases. Highlights of the thesis include in particular the methodical development regarding Resonant X-Ray Diffraction, such as the first use of partially forbidden reflections to get the complete phase information not only of the tensorial structure factor but of each individual atomic scattering tensor for a whole spectrum of energies, as well as the determination of orbital degrees of freedom and details of the partial local density of states from these tensors. On the material side, the most prominent results are the identification of the migration-induced field-stabilized polar phase and the exergonic redox behavior in SrTiO3 caused by defect migration and defect separation.