[pt] Uma análise de desempenho da transmissão digital, com modulação tipo ON-OFF através de fibras óticas foi feita incluindo todos os estágios do circuito. A partir desta análise foi desenvolvido um método para o dimensionamento e o cálculo da qualidade destes sistemas óticos digitais. O método permite calcular o comprimento máximo da fibra ótica em função das características dos diversos circuitos que compõem o enlace, taxa de transmissão e objetivo de qualidade. / [en] It was made an analysis of performance of digital transmission with modulation ON-OFF through optical fiber including all circuit phases. From this analysis it was developed a method to the dimensioning and the quality calculation of these digital optical systems. This method allows to determine the maximum length of optical fiber, since the characteristics of all enlace circuits, of date rate and the quality objective are known.

Les récepteurs du Fc des Immunoglobulines G (FcγR) sont impliqués dans de nombreuses réactions immunitaires. Deux groupes de faible affinité existent : les FcγRIIa/b/c et les FcγRIIIa/b, FcγRIIb étant le seul inhibiteur. Plusieurs polymorphismes, modifiant l’affinité au ligand et la réponse du récepteur, sont favorisés par une pression de sélection infectieuse et associés aux Maladies Auto-Immunes (MAI). Nous avons étudié l’association des polymorphismes FcγRIIa-R131H, FcγRIIb-I232T, FcγRIIIa-F158V, FcγRIIIb-Na1/Na2 aux Lupus érythémateux systémique (LES), la neuromyélite optique (NMO) et la sclérose en plaque (SEP) en Martinique. Nos résultats montrent une forte fréquence des allèles T232, V158 et des génotypes 232TT et 158VV dans la population générale, une augmentation de la fréquence de l’homozygote Na1, des allèles Na1 et 158F dans le LES, une augmentation du génotype 131RR ainsi que des allèles 131R et 158V dans le LES avec atteinte rénale, une augmentation du génotype 131RR et une diminution du NA2/NA2 dans la SEP ainsi qu’une augmentation de l’allèle 232T dans les NMO. L’étude de l’influence du FcγRIIb-I232T sur l’activation du récepteur à l’antigène des lymphocytes B (BCR) chez des lupiques et des témoins sains porteurs des formes IT, TT ou II montre que la régulation du BCR est effective même en présence de la forme TT. Ces résultats démontrent pour la première fois que la population martiniquaise possède un terrain génétique particulier qui faciliterait l’apparition de MAI avec pronostic plus sévère. / Receptors of Fc of Immunoglobulin G (FcγR) are involved in many immune responses. Two low affinity groups exist: FcγRIIa/b/c, and FcγRIIIa/b, FcγRIIb is the only inhibitor. Several polymorphisms, altering the affinity ligand and receptor response, are selected by an infectious pressure and associated with autoimmune diseases (AID). We studied the association of polymorphisms FcγRIIa-R131H, FcγRIIb-I232T, FcγRIIIa-F158V, FcγRIIIb-Na1/Na2 to systemic lupus erythematosis (SLE), neuromyelitis optica (NMO) and multiple scelrosis (MS) in Martinique. Our results show a high frequency of alleles T232, V158 and 232TT and 158VV genotypes in Martinican, an increase in the frequency of the homozygous Na1, Na1 and 158F alleles in SLE, an increase of 131RR genotype, the 131R and 158V alleles in SLE with kidney disease, an increase of 131RR genotype and a decrease of NA2 / NA2 in MS but an increase in the 232T allele in NMO. Study of the influence of FcγRIIb-I232T on the activation of the B cells receptor (BCR) in lupus and healthy controls controls exibiting IT, TT or II forms, shows that the regulation of BCR is effective even in the presence TT form. These results show for the first time Martinican population has a particular genetic background which would facilitate the appearance of MAI particularly serious.

INTRODUCTION._Le handicap associé aux maladies inflammatoires du système nerveux central (SNC), représentées par la sclérose en plaques (SEP) et la neuromyélite optique de Devic (NMOSD), est sous-tendu par la perte neuronale._x000D_La tomographie par cohérence optique (OCT) et l'imagerie par résonance magnétique (IRM) sont des outils robustes et reproductibles permettant de mesurer la perte axonale in vivo.OBJECTIFS.Développer des biomarqueurs OCT et IRM pour le diagnostic, le pronostic et le suivi des patients atteints de maladies inflammatoires du SNC.MATERIELS et METHODES.Notre IRM est de champ magnétique 3 teslas (Achieva, Philips, Best, Pays Bas). L'appareil OCT est de 4éme génération (Heidelberg Spectralis, Allemagne). (1) Nous avons développé une séquence en tenseur de diffusion (DTI) de la moelle épinière cervicale en acquisition coronale et (2) évalué les corrélations entre les paramètres DTI et le handicap clinique d'une cohorte de patients SEP. (3) Nous avons comparé la séquence 3D-Double Inversion Récupération (DIR) à la séquence 2D-STIR FLAIR coronal pour la détection des hypersignaux inflammatoires du nerf optique.Sur le plan OCT, (4) nous avons participé à une étude multicentrique pour la validation de critères de qualité OCT. (5) Nous avons réalisé une étude OCT comparative de patients SEP, NMOSD et de sujets sains, afin de mettre en évidence des paramètres OCT différenciant les 2 maladies, parmi lesquels l'épaisseur de la pRNFL (globale ou en secteurs) et des couches maculaires (logiciel de segmentation HEYEX). (6) Nous avons évalué la longueur de l'hypersignal DIR du nerf optique comme potentiel biomarqueur de la perte axonale rétinienne évaluée en OCT.RESULTATS.(1) Les paramètres DTI (fraction d'anisotropie [FA], diffusivité moyenne [MD] et radiale [rD]) étaient significativement différents entre les sujets SEP et sains. Chez les sujets SEP, la FA diminue, la MD et la rD augmentent.(2) Dans la SEP, la FA mesurée au sein de la moelle épinière cervicale (C2-C6) était modérément corrélée au handicap clinique du patient mesuré par le score EDSS et les scores fonctionnels pyramidal, sensitif et sphinctérien._x000D_(3) La séquence 3D-DIR était plus précise que le 2D STIR FLAIR pour la détection d'un hypersignal inflammatoire du nerf optique (Se 95%, Sp 94%) et montrait une concordance inter-observateur plus élevée (kappa = 0.96).(4) La concordance inter-observateur des critères de qualité OCT OSCAR-IB était substantielle (kappa = 0.7).(5) Nous mettons en évidence une atrophie rétinienne post ON comparable entre la SEP et la NMOSD. Les patients SEP présentent une atrophie maculaire et de la pRNFL temporale sur les yeux sans névrite optique. Nos résultats suggèrent une possible atrophie maculaire infraclinique chez les sujets NMOSD. Les corrélations entre OCT et handicap visuel étaient bonnes et nombreuses. Dans la NMOSD, les corrélations entre OCT et handicap clinique étaient moins nombreuses et liée à la présence d'un handicap visuel.(6) Nous avons mis en évidence une bonne association (p<0.0001) entre la longueur de l'hypersignal DIR du nerf optique, l'épaisseur de la pRNFL, le volume des couches maculaires internes et le handicap visuel. Près de 40% des yeux indemnes de NO présentaient un hypersignal du nerf optique.CONCLUSIONS.Nous avons développé une séquence DTI analysant la moelle épinière cervicale, applicable en routine et de façon prospective. Les corrélations entre la FA ou la MD et le handicap restent toutefois modérées [...] / BACKGROUND.Inflammatory diseases affecting the central nervous system (CNS) are mainly represented by multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD). Both diseases may be associated with slight to severe clinical disability. There is a need for developing imaging biomarkers which could be used for diagnostic purposes and as potential therapeutic biomarkers. Optical coherence tomography (OCT) and magnetic resonance imaging (MRI) are robust and reproducible tools enabling us to measure axonal loss in vivo.OBJECTIVES.To develop OCT and MRI biomarkers for the diagnosis, prognosis and follow-up of inflammatory diseases affecting CNS.METHODS.Our MRI is a 3 teslas MRI (Achieva, Philips, Best the Netherlands) devoted to research at CHRU de Lille. The OCT tool is a 4th generation spectral-domain OCT (Heidelberg Spectralis, Germany).(1) We firstly developped a coronal diffusion tensor imaging (DTI) sequence for cervical spinal cord and (2) applied it to a large MS cohort in order to evaluate potential DTI/clinical disability correlations. (3) We interested in 3D-Double Inversion Recovery (DIR) sequence for the detection of T2 optic nerve hypersignal and compare its diagnosis accuracy with coronal 2D STIR-FLAIR sequence.Considering OCT, (4) we participated to a multicenter study for validating OCT quality criteria by measuring inter rater agreement. (5) We made a comparative OCT study in MS, NMOSD and healthy controls (HC), in order to describe potential OCT parameters differentiating both diseases. OCT parameters will be peripapillary retinal nerve fiber layers thickness (pRNFL; global and values per quadrants) and macular layers thickness evaluated by HEYEX segmentation software. (6) We investigated the length of optic nerve DIR hypersignal as a potential biomarker for retinal axonal loss measured by OCT.RESULTS.(1) The DTI parameters (fractional anisotropy [FA], mean diffusivity [MD], radial diffusivity [rD]) were significantly different between HC and MS patients. FA was reduced. MD and rD were increased.(2) In MS, FA within cervical spinal cord (C2-C6) was moderately correlated with physical disability measured by EDSS, pyramidal, sensory and bowel/urinary functional scores.(3) 3D-DIR sequence was more accurate than 2D STIR FLAIR for the detection of optic nerve hypersignal (Se 95%, Sp 94%) and showed the higher inter-rater agreement (kappa = 0.96).(4) The inter-rater agreement for OSCAR-IB quality criteria for retinal OCT was substantial (kappa = 0.7).(5) We found comparable post ON atrophy between MS and NMOSD and significant macular and temporal pRNFL atrophy in MS non ON eyes. We suggested possible subclinical macular atrophy in NMOSD. Correlations were good and numerous between OCT parameters and visual disability in both diseases. In NMOSD, correlations between OCT and clinical disability were fewer and more related to visual disability.(6) We found good associations (p<0.0001) between optic nerve DIR hypersignal length, pRNFL thicknesses, inner retinal layers volumes and visual disability. A subclinical radiological involvement of non ON eyes was found in 38.5%.CONCLUSION.We developed a DTI sequence for cervical spinal cord analysis which seems applicable in routine and in a prospective follow-up. However, correlations between FA or MD and clinical disability remain moderate.OCT may help to differentiate NMOSD and MS by focusing on the non ON eyes (temporal pRNFL atrophy more severe in MS). Moreover we discuss the possibility of subclinical retinal degenerative process in NMOSD.We showed the 3D-DIR interest in optic nerve inflammatory lesion detection. 3D-DIR sequence which has largely been considered as a marker of demyelination, may be more pathologically specific (i.e retinal axonal loss) by focusing on a specific part of the CNS (i.e optic nerve). Optic nerve DIR hypersignal may be a new biomarker of retinal axonal loss.

Orientadores: Maria Leticia Cintra, Cassio Menezes Raposo do Amaral / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-07-20T00:27:27Z (GMT). No. of bitstreams: 1 Tiziani_Valdenize_D.pdf: 3584406 bytes, checksum: 71b81f0a408df6231f33acf1b7882c6b (MD5) Previous issue date: 1995 / Resumo: O gel dos implantes de silicona pode entrar em contacto direto com o organismo em decorrência do vazamento através da membrana elastomérica do implante ou devido à rotura desta membrana. Estudou-se os efeitos da silicona gellivre injetada no tecido subcutâneo de ratos. Analisou-se as características morfológicas dos gânglios linfáticos axilares e inguinais. Foram injetados 3 cm3 de silicona gel no tecido subcutâneo de 96 ratos Wistar. Os animais do grupo controle (96 ratos Wistar) receberam injeção subcutânea de água destilada. Oito animais tratados e oito animais controle foram sacrificados decorridos 1, 3, 7, 9, 15, 30, 60, 90, 120, 180, 270 e 365 dias da injeção. Não foram observadas alterações morfológicas nos gânglios linfáticos sugestivas de migração ou de resposta reacional à silicona gel. Pequenas quantidades não detectáveis de silicona poderiam migrar para os gânglios linfáticos e provocar hiperplasia daquelas estruturas. Para avaliar esta possibilidade fêz-se um estudo morfométrico auxiliado por computador, onde comparou-se a área dos cortes dos gânglios linfáticos dos animais tratados com os do grupo controle. A análise estatística não mostrou diferenças significativas entre o grupo tratado e o controle. Se ocorreu migração de silicona, não provocou manifestação morfológica de hiperplasia dos gânglios linfáticos / Abstract: The gel of the silicone gel implants may bleed through the elastomeric envelope or may enter in contact with the organism due to a rupture of the implant. It was studied the effects of free silicone gel injected into the subcutaneous tis sue of rats. It was analysed the morphologic features of the axilar and inguinallymph nodes. Ninety six Wistar rats were injected in their subcutaneous space with 3 cm3 of silicone gel. The animaIs of control group, ninety six Wistar rats, were injected in their subcutaneous space with distilled water. The animaIs were sacrificed on days: 1, 3, 7, 9, 15, 30, 60, 90, 120, 180, 270 and 365 after the injection. There was no detectable silicone and no damage to the lymph nodes based on routine histopathological analysis. Little amounts of silicone that could migrate to lymph nodes could result in hyperplasia. In order to evaluate this possibility, a morphometric study based on a computer aided system compared the area of lymph node sections between treated and contraI animais. The statistical analysis didn't show any difference between treated and control groups. If silicone migration ocurred it did not provoke morphologic manifestation or hyperplasia of the lymph nodes / Doutorado / Anatomia Patologica / Doutor em Ciências Médicas

[pt] O interesse no monitoramento da integridade estrutural de risers flexíveis tem crescido significativamente nos últimos anos. Para dutos que já estão atingindo sua vida de projeto, sistemas de monitoramento podem fornecer alertas antecipados de possíveis falhas e também auxiliar o operador na programação de paradas para manutenção. Diferentes técnicas estão sendo testadas pelos operadores de dutos flexíveis tais como inspeção visual automatizada, monitoramento de vibrações e emissão acústica, além de técnicas baseadas em métodos eletromagnéticos. Algumas destas técnicas já estão sendo implementadas em unidades de exploração e produção marítimas no Brasil e em outros países. A presente contribuição aborda o monitoramento contínuo e em tempo real utilizando sensores a fibra óptica (Redes de Bragg) para detectar a ruptura dos arames nas armaduras de tração de risers flexíveis. Duas linhas são seguidas, monitoramento direto e monitoramento indireto. O monitoramento indireto consiste na instrumentação da capa polimérica do riser, de forma não intrusiva, e avalia possíveis alterações na mesma, causadas pelo rompimento dos arames. Para isso foi desenvolvido um transdutor, denominado Colar 3D, capaz de detectar variações no diâmetro externo, elongação e torção no duto. A técnica de monitoramento direto é denominada MODA (Monitoramento Óptico Direto nos Arames). Nesta técnica os arames são instrumentados individualmente com os sensores ópticos, que monitoram as tensões/deformações dos mesmos, assim, rompimentos de arames e comportamentos inesperados podem ser facilmente detectados. Resultados de ensaios em escala real mostraram que a probabilidade de detecção do monitoramento indireto aumenta significativamente quando o sistema é empregado em conjunto com outros tipos de monitoramento indireto. Os resultados de laboratório para o monitoramento direto apontaram alta sensibilidade e confiabilidade do sistema, que já foi instalado em três plataformas operadas pela Petrobra na Bacia de Campos. / [en] The interest in structural health monitoring of flexible risers has grown significantly in recent years. For ducts that are already reaching their design life, monitoring systems can provide early warnings of potential failures and also assist the operator in scheduling downtime. Different techniques are being tested by operators of flexible pipes such as automated visual inspection, vibration monitoring and acoustic emission, in addition to techniques based on electromagnetic methods. Some of these techniques are already being implemented in units of maritime exploration and production in Brazil and other countries. This contribution discusses the continuous monitoring and real-time using optical fiber sensors (FBGs) to detect the breaking of wires in the tensile armor of flexible risers. Two lines are followed, direct monitoring and indirect monitoring. The proposed indirect monitoring technique consists in the nonintrusive instrumentation of the riser’s polymeric outer sheath, which will provide strain signals that change due to the breaking of wires in the armor layer. For that, a transducer capable of detecting variations in the outer diameter, as well as stretching and twisting in the duct was developed. In the direct monitoring technique, all the wires in the external armor layer are individually instrumented with optical sensors that continuously monitor their strains, so that any disruptions of wires and unexpected behavior can be easily detected. Results of full scale laboratory tests showed that the probability of detection of indirect monitoring increases significantly when the system is used in conjunction with other types of indirect monitoring. The laboratory results for the direct monitoring showed high sensitivity and reliability of the system, which has already been installed in three oil rigs operated by Petrobras in the Campos Basin.

[pt] Diante do crescimento do interesse pelos amplificadores Raman faz-se necessário um estudo mais detalhado destes. Uma técnica tradicionalmente já utilizada para analise de atenuação em enlaces, a reflectometria óptica no domínio do tempo, é empregada de maneira inovadora neste trabalho para a observação da amplificação Raman distribuída. O objetivo principal deste trabalho não é a analise de amplificadores Raman, mas sim a apresentação desta técnica como nova ferramenta observação do ganho Raman distribuído em fibras ópticas. / [en] Due to increased interest in Raman amplifiers, a more detailed study of them is required. A technique traditionally used for analysis of attenuation on optical links, time domain optical reflectometry, is used in an innovative way in this work for observation of distributed Raman amplification. The main objective of this work in not the analysis of Raman amplifiers, but the introduction of this technique as a new tool for the observation of distributed Raman gain in optical fibers.

[pt] Um estudo completo da dispersão dos modos de polarização (PMD) em fibras ópticas foi apresentado. Uma nova proposição de Emuladores de PMD com comprimentos de acoplamento aleatóriamente gerados foram comparados, teórica e experimentalmente, com os comumente encontrados na literatura. Um novo método para a medida da freqüência óptica em função do tempo baseado na técnica da discriminação de freqüências ópticas através de um filtro foi apresentado, mostrando suas vantagens sobre outro método encontrado na literatura. Utilizando este novo método foram medidas as características espectrais de alguns lasers DFB modulados em alta freqüência. Os efeitos das PMDs de primeira e segunda ordem em transmissões digitais de alta capacidade foram avaliados, através de medidas da distorção temporal do pulso óptico, bem como pelas penalidades de potência induzidas. O tratamento estatístico das penalidades de potência foi discutido, mostrando que as distorções por PMD de segunda ordem podem levar a uma eventual melhora do desempenho do sistema. Foi proposto um modelamento teórico para a PMD em fibras ópticas, baseado no comportamento observado nos novos emuladores de PMD ccom comprimento de acoplamento aleatório. / [en] A complete study of polarization mode dispertion (PMD) in optical fibers is presented. A new class of PMD emulators with random mode coupling lengths is proposed and compared experimentally and theoretically with other emulators exinting measurements, based in a optical filter transfer function is also presented and compared with the preceding method.With this new method the time domain spectral characteristics of some high frequency modulated DFB lasers were measured. First and second order PMD effects in high speed digital transmission were evaluated through both temporal distortion and power penalties measurement. The statistical treatment of the power penalties was discussed, showing that signal distortion by PMD may eventually improve the performance of the system. A theoretical model of simulate the signal propagation along the fiber was porposed, based on the emulator conception with random coupling lengths.

[pt] As teorias clássicas da propagação das ondas eletromagnéticas em presença da terra apresentam soluções gerais que, em vista da complexidade matemática, não se aplicam diretamente aos casos práticos. Desta forma, partindo destas soluções, procura-se determinar aproximações que simplifiquem os cálculos de propagação. Entretanto, devido às condições supostas na obtenção das soluções aproximadas, estas apresentam uma região de validade restrita e a sua aplicação indevida pode acarretar erros inaceitáveis. Este fato, no entanto, não tira o mérito das soluções aproximadas, que, quando empregadas corretamente, fornecem resultados bastante satisfatórios em comparação com os experimentais. O objetivo do presente trabalho é a análise das aproximações efetuadas na obtenção das expressões usualmente empregadas nos cálculos de propagação, onde se procurará evidenciar as limitações inerentes a cada caso particular. O efeito da ionosfera não será considerado, assim como as variações do índice de refração da atmosfera, responsáveis pelo mecanismo da tropodifusão. / [en] In view of the mathematical complexity, the rigorous solutions of the classical theories of radio wave propagation in the presence of the earth are not directly applied to practical problems. Hence, based on these rigorous solutions, approximate expressions are developed to simplify the eveluation of radio wave signal attenuation. However, due to assumptions considered in the derivation of such solutions, they have a limited range of validity and, if erroneously used, can lead to unacceptable errors. Nevertheless, this fact does not take out the merit of the approximate solutions, once when they are correctly employed the numerical results are in accordance with the experimental data. This dissertation intends to analyze the approximations usually carried out in radio wave propagation problems, pointing out limitations associated to each particular case. The effect of the ionosphere will not be considered, as well as, the variability of the refractive index of the troposphere responsibe by the scatter propagation mechanism.

Neuromyelitis Optica (NMO) is a rare, autoimmune, neurodegenerative disease selectively affecting the optic nerves and spinal cord. Relapsing NMO is nine times more prevalent in women than in men and approximately one-quarter of NMO patients have symptoms of another autoimmune disorder (National Institute of Health, 2019). NMO has not been linked to any genetic mutations and the cause of the disorder is unknown beyond the general understanding that the body produces anti-aquaporin-4 antibodies (AQP4) which mistakenly attack cells in the nervous system. NMO affects roughly one percent of that of Multiple Sclerosis (4000-8000 patients total) in the United States, but prevalence rates are abnormally high in a handful of regions around the world, particularly among Latin America, where rates can reach up to 5/100,000 individuals. The results of this study predict that there is a connection between African genetics and NMO, but further studies will need to be conducted in more Latin America nations and other regions to determine prevalence rates as well as genetic analysis of affected individuals.

El propósito de esta tesis se enmarca dentro del campo de la óptica no lineal y, como el problema es formalmente idéntico, tiene aplicación directa en el campo de la materia condensada, en particular en los condensados de Bose-Einstein. El objetivo es obtener una nueva herramienta teórica que permita analizar la dinámica de una solución no lineal estacionaria sometida a una perturbación pequeña. Nos centraremos en soluciones que llenen todos los nodos de la red, y, por lo tanto, que tienen simetría traslacional en el caso periódico y son aperiódicas en el caso cuasiperiódico. El punto de partida es la ecuación de Schrödinger no lineal (ESNL) y obtenemos las ecuaciones efectivas para la envolvente de la solución en el régimen de bajas energías, es decir, bajo la aproximación de que las variaciones son suaves en comparación con el espaciado de la red, tanto en potenciales periódicos como cuasiperiódicos, e intentamos llenar el vacío teórico existente en el último caso. Estas ecuaciones describen la dinámica, a bajas energías o largo alcance, de la envolvente de la solución no lineal. El primer paso es la obtención de las ecuaciones discretas de la ESNL, es decir, las ecuaciones que se obtienen como consecuencia de la expansión del campo en funciones localizadas sobre la red. Se hace uso de la base de funciones de Wannier solución del problema no lineal estacionario, en lugar de la aproximación clásica que utiliza como base las funciones de Wannier lineales. Se introduce el concepto de envolvente para analizar el comportamiento del sistema en las proximidades de la solución no lineal. Pasamos al continuo haciendo el límite cuando el espaciado de la red tiende a 0. Se demuestra que la ecuación efectiva que se obtiene es libre de potencial. En el caso cuasiperiódico, el marco de la geometría no conmutativa resultará ser la herramienta adecuada para tratar el problema. / Monreal Mengual, L. (2010). Equacions efectives de l'equació de Schrödinger no lineal en sistemes periòdics i quasiperiòdics [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/8500