La thèse porte sur la génération de fronts d’ondes de test en milieu réverbérant pour la mesure d’antennes Ultra Large Bande. L’objectif est de générer des fronts d’ondes déterministes convergents, respectant les standards de mesure d'antennes, dans un milieu diffusif caractérisé par une décohérence spatiale, temporelle et fréquentielle. Les performances intéressantes, visées pour l’application, sont la génération temps réel, l’utilisation d’un nombre limité de sources et l’obtention d’un rendement de conversion d’énergie élevé. Tout d’abord, nous présentons des concepts de mesure d’antennes et montrons, les limites des méthodes actuelles pour la réalisation de caractérisations rapides permettant un niveau de rapport signal à bruit satisfaisant et n'utilisant pas de sources multiples. Puis, nous introduisons notre moyen d’essai, le système Time reversal Electromagnetic Chamber (TREC), constitué notamment d’une chambre réverbérante, dans laquelle un principe non standard de retournement temporel est utilisé pour générer des fronts d’ondes cohérents et convergents d’espace libre. Nous cherchons alors à étendre les capacités de la TREC à la génération des fronts d’ondes de test convergents et localement plans. Dans une phase d'étude préalable, nous développons deux approches pour synthétiser la propagation en espace libre des fronts d’ondes de mesure. Les techniques utilisées reposent sur l’utilisation de l’opérateur Slepian, permettant la résolution des contraintes imposées par les propriétés spécifiques des distributions de champ. La solution optimale de caractérisation a permis de générer des fronts d'ondes comportant une résolution angulaire. La synthèse des fronts d'ondes de test est utilisée dans des simulations électromagnétiques de TREC 2D et 3D. Les résultats ont validé la faisabilité de la génération de fronts d’ondes convergents, localement plans et résolus angulairement. / This contribution corresponds to the generation of test wavefronts in reverberation chamber for antenna Ultra Wide Band characterization. We were interested in generating deterministic convergent wavefronts, fulfilling the antenna measurement standard, in a diffusive medium characterized by a spatial, temporal and frequency decoherence. The interesting performances referred to the application, are the real-time synthesis, the use of a limited number of sources and the high energy conversion efficiency. First we present the concepts of antenna measurement and the limitations of current methods for achieving quick characterization with a sufficient signal to noise ratio without multiple sources. Then, we introduce our system, the Time Reversal Electromagnetic Chamber (TREC), which is mainly constituted by a reverberation chamber, in which a non-standard time reversal principle is used for coherent convergent free space wavefronts generation. Then we try to extend the TREC capacities to the generation of free space convergent and locally plan wavefronts. In a preliminary study, we develop two approaches to synthesize the free space propagation of the wavefronts. The used techniques are based on the utilization of the operator Slepian, allowing the resolution of the constraints determined by the specific properties of the field distribution. The optimal solution allowed generating wavefronts characterized by angular resolution. Test wavefronts synthesis is used in 2D and 3D TREC electromagnetic simulations. Results validated the feasibility of the generation of locally plan convergent wavefronts with angular resolution.

Made available in DSpace on 2016-04-04T18:27:35Z (GMT). No. of bitstreams: 1 GLAUCIA MITSUKO ROCHA.pdf: 493337 bytes, checksum: 75d110b5c61b2396ceab94011e243e75 (MD5) Previous issue date: 2002-12-18 / Considering the evidence of reliability and validity of the Escala Diagn?stica Adaptativa Operacionalizada-Redefinida (EDAO-R) when applied to adults, and the necessity to expand the range of tools and procedures available for the assessment of the elderly people, the main goal of this study is to estimate EDAO-R s reliability and convergent validity applied to the elderly people. Ss were 80 older persons (60 years old or more), of both genders (85% of women), who attend to third age groups. The majority (66,25%) was in the young-old group (60-69 years old), was either married (42,5%) or widowed (40%), having son (83,75%), catholic (75%), retired (61,25%), with many different professions, living in their own home (83,75%), alone (28,75%) or with husband / wife (27,5%), and of middle class (61,3%). EDAO-R is a clinical assessment, and then the reliability was taken from an interrater coefficient (Cohen s kappa) between two independent judges. The convergent validity was taken across assessment instruments, Ferrans and Power s Quality of Life Index (IQV) and the Geriatric Depression Scale (GDS-15), as external criterion. The results showed statistically significant interaction, taken through the Spearman s correlation test, between EDAO-R and age (rs= -0,261, p<0,01) and, through the Contingency test between EDAO-R and the person s occupational conditions (C=0,468, p<0,05). The sample tended to the best adaptive levels when assessment through EDAO-R, as to the best scores when assessment through IQV and GDS-15. The reliability for the adaptive efficacy was ? =0,503. When analyzed by EDAO-R s sectors, the Affective-Relational had k=0,551; Productivity had k=0,459; Organic had k=0,612 and the Social-Cultural had k=0,650, which are considered from fair to good. Statistically significant interactions were observed through Spearman s correlation test, between EDAO-R and IQV (rs=-0,449, p<0,01) and between EDAO-R and GDS-15 (rs=0,397, p<0,01). The results are discussed considering the socio-demographic profile of the sample, and indicate that EDAO-R is a reliable and valid measure of the adaptive efficacy when applied to the elderly people who attend to third age groups. Besides that, considering the used operational assessment categories, it s possible to obtain good agreement scores between independent judges. / Considerando as evid?ncias de precis?o e validade da Escala Diagn?stica Adaptativa Operacionalizada-Redefinida (EDAO-R) quando aplicada a adultos e a necessidade de se ampliar o leque de instrumentos e procedimentos dispon?veis para a avalia??o da pessoa idosa, este estudo teve como objetivos estimar a precis?o e a validade convergente da EDAO-R, aplicada a pessoas idosas. Foram avaliadas 80 pessoas, com 60 anos ou mais de idade, de ambos os sexos, predominantemente mulheres (85%), freq?entadoras de grupos da terceira idade, com idades entre 60 e 69 anos (66,25%), casadas (42,5%) ou vi?vas (40%), tendo filhos (83,75%), de religi?o cat?lica (75%), aposentadas (61,25%), com profiss?es diversificadas, residindo em moradia pr?pria (83,75%), sozinhas (28,75%) ou com o c?njuge (27,5%), e de classe m?dia (61,3%). Por se tratar de avalia??o cl?nica, a precis?o foi estimada atrav?s de coeficiente de acordo (kappa de Cohen) entre dois ju?zes independentes. A validade convergente foi estimada utilizando-se o ?ndice de Qualidade de Vida (IQV), de Ferrans e Powers c a Geriatric Depression Scale (GDS-15), como crit?rios externos. Obteve-se associa??es estatisticamente significantes, atrav?s do teste de correla??o de Spearman, entre a EDAO-R e idade (rs= -0,261, p<0,01) e, atrav?s do teste de Conting?ncia, entre a EDAO-R e a condi??o ocupacional da pessoa (C=0,468, p<0,05). A amostra tendeu aos melhores n?veis adaptativos, quando avaliada pela EDAO-R, assim como aos melhores escores, quando avaliada pelo IQV e pela GDS-15. O coeficiente de precis?o obtido para a efic?cia adaptativa geral foi te=0,503. Avaliada por setores, o Afetivo- Relacional obteve k=0,551; o da Produtividade, te=0,459; o Org?nico, k=0,612 e o S?cio-Cultural k=0,650, coeficientes considerados de moderados a bons. Foram observadas associa??es estatisticamente significantes, atrav?s do teste de correla??o de Spearman, entre a EDAO-R e o IQV (rs=-0,449, p<0,01 e entre a EDAO-R e a GDS-15 (rs=0,397, p<0,01). Os resultados s?o discutidos em fun??o do perfil s?cio-demogr?fico da amostra e indicam que a EDAO-R ? uma medida precisa e v?lida da efic?cia adaptativa quando aplicada a pessoas idosas que freq?entam atividades em grupos da terceira idade. Al?m, disto, em fun??o da boa operacionaliza??o das categorias de avalia??o, ? poss?vel obter-se bons ?ndices de acordo entre avaliadores independentes.

Nesta tese, introduzimos o conceito de sequência convergente de permutações e provamos a existência de um objeto limite para tais sequências. Introduzimos ainda um novo modelo de permutação aleatória baseado em tais objetos e introduzimos um conceito novo de distância entre permutações. Provamos então que sequências de permutações aleatórias são convergentes e provamos a equivalência entre esta noção de convergência e convergência nesta nova distância. Obtemos ainda resultados de amostragem e quase-aleatoriedade para permutações. Provamos também uma caracterização para parâmetros testáveis de permutações. / We introduce the concept of convergent sequence of permutations and we prove the existence of a limit object for these sequences. We also introduce a new and more general model of random permutation based on these limit objects and we introduce a new metric for permutations. We also prove that sequences of random permutations are convergent and we prove the equivalence between this notion of convergence and convergence in this new metric. We also show some applications for samplig and quasirandomness. We also prove a characterization for testable parameters of permutations.

Este trabalho tem como objetivo principal a determinação da distância de estrelas pré-sequência principal em regiões de formação estelar próximas. A determinação precisa da distância individual das estrelas é necessária para obter os principais parâmetros físicos de cada estrela e para investigar a estrutura da Galáxia. Em particular, investigamos as regiões de formação estelar de Lupus e Ophiuchus que contém uma das associações mais ricas em estrelas T Tauri. A grande maioria das estrelas pré-sequência principal nessas regiões não foi observada pelo satélite Hipparcos devido à sua magnitude e também não têm paralaxe trigonométrica medida a partir do solo devido à distância em que se encontram. O procedimento aqui empregado para a obter a distância individual das estrelas baseia-se na estratégia de ponto de convergência e utiliza dados de movimento próprio e velocidade radial. Desenvolvemos uma nova versão do método de ponto de convergência que permite simultaneamente determinar a posição do ponto de convergência e selecionar os membros de um moving group. Partindo dos dados de movimento próprio e o novo método aqui desenvolvido investigamos as propriedades cinemáticas e realizamos uma análise de pertinência das estrelas em cada região estudada o que nos permitiu identificar um moving group com 114 estrelas em Lupus e 55 estrelas em Ophiuchus. Calculamos a distância para cada membro do grupo usando velocidades radiais publicadas, que foram complementadas com novas observações, e a velocidade espacial do moving grup para as estrelas com velocidade radial não conhecida. Calculamos as paralaxes com precisão de 1-2~mas o que implica em um erro relativo médio de 25% nas distâncias obtidas. Finalmente, investigamos as propriedades dos diversos subgrupos e a estrutura tridimensional dos complexos de nuvens em Lupus e Ophiuchus, concluindo que existem efeitos de profundidade importantes. Utilizamos os novos resultados de distância para obter os parâmetros físicos (luminosidade, massa e idade) das estrelas e o diagrama-HR de cada região de formação estelar considerada, confirmando a distribuição de idade diferente das duas subclasses de estrelas T Tauri. Os resultados aqui obtidos representam um primeiro passo no sentido de melhor entender a estrutura das regiões de formação estelar e os estágios iniciais da formação de estrelas e planetas. / The main objective of this work is to determine the distance of pre-main sequence stars in nearby star-forming regions. A precise determination of the distance to individual stars is required to accurately determine the main physical parameters of each star and the structure of the Galaxy. Here we investigate the Lupus and Ophiuchus star-forming regions that contain one of the richest associations of T Tauri stars. Most pre-main sequence stars in these regions were neither observed by the Hipparcos satellite due to their magnitude nor have any trigonometric parallax measured from the ground due to their distance. The procedure that we use here to derive the distance to individual stars is based on the convergent point strategy and makes full use of proper motion and radial velocity data. We developed a new version of the convergent point search method that simultaneously determines the convergent point position and selects the most likely members of a moving group. Based on proper motion data and our new method we investigate the kinematic properties and perform a membership analysis of the stars in each star-forming region considered that allows us to identify a moving group with 114 stars in Lupus and 55 stars in Ophiuchus. We calculate the distance of each group member using published radial velocities, which we supplemented with new measurements, and the spatial velocity of the moving group for the remaining stars with unknown radial velocity. We derived parallaxes with accuracies of 1-2 mas yielding the average relative error of 25% on the distances. Finally, we investigate the properties of the various subgroups and the three dimensional structure of the Lupus and Ophiuchus cloud complex and conclude that significant depth effects exist. We use the new distances to refine the physical parameters (luminosity, mass and age) of stars and the HR-diagram for each star-forming region considered confirming the different age distribution of the two T Tauri subclasses. These results represent a first step towards better understanding the structure of star-forming regions and the early stages of star and planet formation.

No description available.

No description available.

These studies compare neurotransmitter localization and the behavioral functions of homologous neurons in nudibranch molluscs to determine the types of changes that might underlie the evolution of species-specific behaviors. Serotonin (5-HT) immunohistochemistry in eleven nudibranch species indicated that certain groups of 5 HT-immunoreactive neurons, such as the Cerebral Serotonergic Posterior (CeSP) cluster, are present in all species. However, the locations and numbers of many other 5 HT-immunoreactive neurons were variable. Thus, particular parts of the serotonergic system have changed during the evolution of nudibranchs. To test whether the functions of homologous neurons are phylogenetically variable, comparisons were made in species with divergent behaviors. In Tritonia diomedea, which crawls and also swims via dorsal-ventral body flexions, the CeSP cluster includes the Dorsal Swim Interneurons (DSIs). It was previously shown that the DSIs are members of the swim central pattern generator (CPG); they are rhythmically active during swimming and, along with their neurotransmitter 5-HT, are necessary and sufficient for swimming. It was also known that the DSIs excite efferent neurons used in crawling. DSI homologues, the CeSP-A neurons, were identified in six species that do not exhibit dorsal-ventral swimming. Many physiological characteristics, including excitation of putative crawling neurons were conserved, but the CeSP A neurons were not rhythmically active in any of the six species. In the lateral flexion swimmer, Melibe leonina, the CeSP-A neurons and 5-HT, were sufficient, but not necessary, for swimming. Thus, homologous neurons, and their neurotransmitter, have functionally diverged in species with different behaviors. Homologous neurons in species with similar behaviors also exhibited functional divergence. Like Melibe, Dendronotus iris is a lateral flexion swimmer. Swim interneuron 1 (Si1) is in the Melibe swim CPG. However, its putative homologue in Dendronotus, the Cerebral Posterior ipsilateral Pedal (CPiP) neuron, was not rhythmically active during swim-like motor patterns, but could initiate such a motor pattern. Together, these studies suggest that neurons have changed their functional relationships to neural circuits during the evolution of species-specific behaviors and have functionally diverged even in species that exhibit similar behaviors.

Higher frequencies in the MHz and GHz range and the increasing miniaturization lead to a higher load of the SAW (surface acoustic wave) metallizations. This higher SAW load and the intrinsic stresses result in a stress induced material transport, called acoustomigration. These microstructural changes can destroy the characteristic of the SAW device. Different Al based material combinations were investigated by different authors to improve the reliability of the metallizations and to delay the cost-intensive change to Cu based metallizations. The Cu based metallizations with TaSiN diffusion barriers were also investigated in this work. The barrier layers are necessary to impede the oxygen diffusion into the Cu layer and the Cu diffusion into the piezoelectric substrate. Also in this work the analytical TEM were used as a tool to investigate these microstructural changes in the SAW electrodes. Chemical changes in the metallizations were analysed by EDXS and EELS. The locally high resolved stress measurement in metallizations is a challenge for the future. The CBED (convergent beam electron diffraction) technique has shown the best resolution, however, it can only be applied to TEM lamellas. The aim of this work was to measure the stress within the SAW metallizations by using the CBED method. With it, we could correlate the microstructural changes with the causing stresses within the metallizations. To qualify the CBED method the thermal expansion of Al and Cu single crystals was measured by using a new model for thin TEM lamallas.

Studies of geologic and geophysical data from the offshore of India have revealed two geologically distinct areas with inferred gas hydrate occurrences: the passive continental margins of the Indian Peninsula and along the Andaman convergent margin. The Indian National Gas Hydrate Program (NGHP) Expedition 01 was designed to study the occurrence of gas hydrate off the Indian Peninsula and along the Andaman convergent margin with special emphasis on understanding the geologic and geochemical controls on the occurrence of gas hydrate in these two diverse settings. NGHP Expedition 01 established the presence of gas hydrates in Krishna- Godavari, Mahanadi and Andaman basins. The expedition discovered one of the richest gas hydrate accumulations yet documented (Site 10 in the Krishna-Godavari Basin), documented the thickest and deepest gas hydrate stability zone yet known (Site 17 in Andaman Sea), and established the existence of a fully-developed gas hydrate system in the Mahanadi Basin (Site 19).

Les anomalies du tube neural (ATN), incluant l'anencéphalie et le spina-bifida, représentent un groupe de malformations congénitales très fréquentes chez l'homme. Ces anomalies sont causées par un défaut partiel ou complet de la fermeture du tube neurale au cours de l'embryogenèse. Les ATN ont une étiologie complexe et multifactorielle impliquant des facteurs environnementaux et génétiques. La voie de signalisation non-canonique du Frizzled (Fz)/Dishevelled (Dvl) contrôle la polarité cellulaire planaire (PCP) et le processus morphogénétique appelé l’extension convergente qui est essentiel pour la gastrulation et la fermeture du tube neural. Très important, des mutations des gènes de cette voie étaient fortement associées aux ATN chez la souris et l’humain. Scribble est un gène de la voie PCP qui cause une sévère ATN chez la souris Circletail. Notre étude vise à analyser le rôle de SCRIBBLE1 dans les ATN humains par des analyses de séquence de son cadre de lecture et ses jonctions exon-introns. Notre étude comporte 396 patients recrutés au Centre Spina Bifida de l’hôpital Gaslini en Gènes, Italie et 83 patients recrutés au Centre Spina Bifida de l’hôpital Sainte Justine. Les patients sont affectés par plusieurs formes d’ATN. Nous avons identifié neuf mutations rares et non synonymes chez 10 patients, p.Asp93Ala (c. 435G>A), p.Gly145Arg (c. 278A>C), p.Gly263Ser (c. 786C>A), p.Gly469Ser (c. 1405G>A), p.Pro649His (c. 1946C>A), p.Gln808His (c. 2424G>T), p.Val1066Met (c. 3196G>A), p.Arg1150Gln (c. 3480G>A) et p.Thr1422Met (c. 4266C>T). Cinque mutations, p.Gly263Ser, p.Pro649His, p.Gln808His, p.Arg1150Gln, p.Thr1422Met, étaient absentes dans les contrôles analysés et prédites d’être pathogéniques in silico. Cette étude montre que des mutations rares dans SCRIB1 pourraient augmenter le risque des ATN dans une fraction des patients. L’identification des gènes prédisposant aux ATN nous aidera à mieux comprendre les mécanismes pathogéniques impliqués dans ces maladies. / Neural tube defects (NTDs), including anencephaly and spina bifida, represent a group of very common birth defects in humans. These anomalies are caused by a partial or complete failure of neural tube closure during embryogenesis. NTDs have a multifactorial etiology involving environmental and genetic factors. The non-canonical signaling pathway Frizzled (Fz) / Dishevelled (Dvl) controls the planar cell polarity (PCP) and the morphogenetic process called convergent extension (CE) which is essential for gastrulation and neural tube closure. Importantly, mutations in genes of this pathway were strongly associated with NTDs in mice and humans. Scribble is a PCP gene that causes a severe NTD mouse Circletail. Scribble binds to another PCP protein, Stbm / Vang, and they cooperate together for the stability of the PCP pathway. Our study aims at investigating the role of SCRIBBLE1 in human NTDs by sequence analyses of its open reading frame and exon-intron junctions. The cohort included in this study consisted of 396 patients recruited at the Spina Bifida Centre of Gaslini Hospital in Genoa, Italy, and 83 patients recruited at the Spina Bifida Center of the Sainte Justine Hospital, Montreal, Canada. Patients were affected by several forms of NTDs. We identified nine non-synonymous and rare mutations in 10 patients: p.Asp93Ala (c. 435G>A), p.Gly145Arg (c. 278A>C), p.Gly263Ser (c. 786C>A), p.Gly469Ser (c. 1405G>A), p.Pro649His (c. 1946C>A), p.Gln808His (c. 2424G>T), p.Val1066Met (c. 3196G>A), p.Arg1150Gln (c. 3480G>A) and p.Thr1422Met (c. 4266C>T). Five of those mutations, p.Gly263Ser, p.Pro649His, p.Gln808His, p.Arg1150Gln, p.Thr1422Met, were absent in all controls analyzed and were predicted to be pathogenic using bioinformatics. Our study demonstrates that rare mutations in SCRIB1 could predispose to NTDs in a fraction of patients. The identification of genes that predispose to ATN will help us better understand the pathogenic mechanisms involved in these diseases.