The main goal of this thesis is to investigate the nature of an optional consonant deletion process, through an articulatory and acoustic study of word-final consonant clusters in Persian. Persian word-final coronal stops are optionally deleted when they are preceded by obstruents or the homorganic nasal /n/. For example, the final clusters in the words /næft/ “oil”, /suχt/ “burnt” and /qæsd/ “intention” are optionally simplified in fast/casual speech, resulting in: [næf], [suχ], and [qæs]. What is not clear from this traditional description is whether the coronal stop is truly deleted, or if a coronal gesture is produced, but not heard, because it is obscured by the adjacent consonants. According to Articulatory Phonology (Browman & Goldstein 1986, 1988, 1989, 1990a, 1990b, 1992, 2001), the articulatory gestures of the deleted segments can still exist even if the segments are not heard. In this dissertation, ultrasound imaging was used to determine whether coronal consonant deletion in Persian is categorical or gradient, and the acoustic consequences of cluster simplification were investigated through duration and spectral measures. This phonetic study enables an account for the optional nature of the cluster simplification process. A general phonological account is provided for the simplification of coda clusters with rising sonority, and the acoustic and articulatory investigation focuses on the simplification of clusters with coronal stops. Ten Persian-speaking graduate students from the University of Ottawa and Carleton University, five male and five female, aged 25-38 participated in the articulatory and acoustic study. Audio and real time ultrasound video recordings were made while subjects had a guided conversation with a native speaker of Persian. 662 tokens of word-final coronal clusters were auditorily classified into unsimplified and simplified according to whether they contained an audible [t]. Singleton coda consonants and singleton /t/s were also captured as controls. The end of the constriction plateau of C1 and beginning of constriction plateau of C3 were used to define a time interval in which to measure the coronal gesture as the vertical distance between the tongue blade and the palate. Smoothing Splines ANOVA was used in a novel way to compare tongue blade height over time across the three conditions. The articulatory results of this study showed that the gestures of the deleted segments are often still present. More specifically, the findings showed that of the clusters that sounded simplified, some truly had no [t] gesture, some had gestural overlap, and some had reduced gestures. In order to explain the optional nature of the simplification process, it is argued that the simplified tokens are the result of two independent mechanisms. Inevitable mechanical and physiological effects generate gesturally reduced and overlapped tokens whereas planned language-specific behaviors driven by phonological rules or abstract cognitive representations result in no [t]-gesture output. The findings of this study support the main arguments presented in Articulatory Phonology regarding the underlying reasons for sound patterns and sound change. The results of this study are further used to examine different sound change models. It is argued that the simplified tokens with totally deleted [t] gesture could be the result of speakers changing their representations based on other people’s gestural overlap. This would be instances of the Choice and Chance categories in Blevins’ (2004) CCC sound change model. The acoustic results did not find any major cues which could distinguish simplified tokens from controls. It is argued that articulatory data should form an integral part of phonetic studies.

Dans le cadre du programme nucléaire français, le combustible des réacteurs est constitué d'oxydes d'uranium ou d'oxydes mixtes d'uranium et de plutonium (appelé MOX). Des développements sont constamment effectués sur les procédés de retraitement de ces combustibles afin d'optimiser la récupération des matières valorisables et de minimiser le volume des déchets. Lors de la dissolution des MOX, la quantité de fines de dissolution résiduelles riches en Pu est parfois importante malgré l'utilisation de conditions chimiques dures (oxydantes et corrosives). La difficulté à dissoudre des lots de PuO2 déclarés non conformes lors de la fabrication du MOX peut également représenter un verrou technologique. Dans ce contexte, la sonochimie est envisagée comme alternative aux méthodes actuelles de dissolution de PuO2, ou de MOX enrichi en Pu. Dans un premier temps, des travaux de dissolution sonochimique ont été réalisés sur un analogue inactif de PuO2, à savoir CeO2. Les résultats obtenus ont ainsi permis d'orienter les expériences de dissolution de PuO2. En conditions réductrices et acides, beaucoup plus douces que celles utilisées industriellement, la dissolution totale de ces deux oxydes a été effectuée en quelques heures. Parallèlement, une étude connexe a montré qu'il est possible de dissoudre totalement des oxydes mixtes de lanthanides à base de Ce, par un procédé de dissolution sonocatalytique et réductrice en présence de nanoparticules de Pt. La dissolution est d'autant plus rapide que la teneur en lanthanides trivalents est importante au sein de l'oxyde. Enfin, une dernière partie a été consacrée à la dissolution sous agitation magnétique d'oxydes à base de Ce en présence ou non de métaux nobles, dans des milieux faiblement acides contenant des molécules naturelles réductrices. Dans ces conditions, une dissolution totale, rapide et sélective de ces oxydes a été observée. Ces deux dernières études présentent un intérêt dépassant le cadre du nucléaire et applicable au recyclage de matériaux industriels (pots catalytiques, piles à combustible…). / In the French nuclear program, the reactor fuel consists of uranium oxides or uranium plutonium mixed oxides (called MOX). Developments are constantly made on the resulting reprocessing of these fuels in order to optimize the recovery of reusable materials and to minimize the waste volume. In the case of MOX dissolution, the amount of Pu-rich dissolution residues is sometimes high despite the use of hard chemical conditions (oxidizing and corrosive). The difficulty to dissolve PuO2 batches declared non-standard during the fabrication of MOX can also be a technological barrier. In this context, sonochemistry can be considered as an alternative to current methods of dissolution of PuO2 or Pu enriched MOX. First, experiments of sonochemical dissolution were performed on an inactive analogue of PuO2, namely CeO2. The results were then used as a working basis for the dissolution of PuO2. Under reducing and acidic conditions, much milder than those used industrially, the complete dissolution of these two oxides was carried out within a few hours. Meanwhile, a related study showed that it is possible to completely dissolve lanthanide mixed oxides by a process of sonocatalytic and reductive dissolution in the presence of Pt. The dissolution rates increase with the trivalent lanthanide content within the oxide. Finally, the last part was devoted to the dissolution under magnetic stirring of Ce-based oxides in the presence or absence of noble metals, in weakly acidic media containing reducing natural molecules. Under these conditions, a complete, rapid and selective dissolution of these oxides was observed. These last two studies present an interest beyond the scope of nuclear chemistry, concerning the recycling of industrial materials (catalytic converters, fuel cells...).

Le contrôle des caractéristiques des cristaux de glace, gouvernées par l'étape de nucléation, demeure un enjeu majeur dans les procédés de congélation et de lyophilisation industriels. Cependant la nucléation est par nature un phénomène aléatoire. L'application d'ultrasons de puissance, capable de générer de la cavitation acoustique, compte très certainement parmi les plus prometteuses méthodes permettant de contrôler le déclenchement de la nucléation, mais le matériel et les conditions opératoires à mettre en oeuvre afin d'industrialiser le procédé restent encore à définir.Le premier objectif de ce travail a été de corréler empiriquement les caractéristiques géométriques des cristaux de glace et les conditions opératoires dans le cas de la congélation d'une solution aqueuse de mannitol en vials. Il a été montré, grâce à une analyse de surface de réponses basée sur un plan d'expérience de deuxième ordre, que l'augmentation du sous refroidissement et de la puissance acoustique provoquent une diminution de la taille moyenne des cristaux et une augmentation de leur circularité.Le deuxième objectif était la modélisation de la cinétique de nucléation de glace dans de l'eau pure déclenchée par cavitation acoustique. D'après les simulations réalisées, la nucléation peut être initiée à de faibles sous-refroidissements (quelques degrés) au moyen de pressions acoustiques modérées (de l'ordre de un bar). Le nombre de nuclei créés est d'autant plus important que le sous-refroidissement et la pression acoustique sont élevés.Ces résultats sont cohérents si l'on considère que la taille des cristaux est inversement proportionnelle au nombre de nuclei générés. / Ice crystal characteristics control, which are governed by the nucleation step, remains a key issue in industrial freezing and freeze-drying processes. However nucleation is by nature arandom phenomenon. Power ultrasounds, able to generate acoustic cavitation, are one of the most promising methods of triggering nucleation, but operating conditions pertaining to an industrial freezing process have not yet been defined.This work aims first at empirically correlating the ice crystals' geometry to the operating conditions, in the case of mannitol aqueous solution in vials freezing. A response surface analysis based on a second order experimental design proved that increasing both supercooling and acoustic power resulted in decreasing ice crystals' mean size and increasing their circularity.The second goal was the modelling of ice nucleation triggered by acoustic cavitation in pure water. According to simulations, the nucleation could be initiated with moderate acoustic pressure amplitude (around one bar) even at low supercooling levels (around few degrees). The number of generated nuclei appeared to increase with the super cooling and with the acoustic power which should lead to a decrease of ice crystals' size as observed experimentally.These results are consistent if the ice crystals' size is considered to be inversely proportional to the number of generated nuclei.

Orientador: Miriam Dupas Hubinger / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-27T10:07:35Z (GMT). No. of bitstreams: 1 Rabelo_RenataSantos_M.pdf: 54735801 bytes, checksum: 79deeea44988fbcfd818411f5b804573 (MD5) Previous issue date: 2015 / Resumo: A alcachofra (*Cynara scolymus L.*) é uma herbácea perene pertencente à família *Asteraceae. *A espécie, rica em compostos fenólicos, é originária de regiões subtropicais, mas também é cultivada no Brasil, onde maior parte da produção se concentra no interior paulista e é voltada à indústria de conservas*,* que geralmente descarta como resíduo, brácteas externas e internas da planta. Em vista disso, o presente trabalho teve como objetivo, desenvolver extratos ricos em compostos bioativos, principalmente fenólicos, a partir dos resíduos de alcachofra, por meio do estudo do processo de extração assistida por ultrassom e da avaliação do desempenho do processo de concentração por membranas. Inicialmente, foram estudadas as variáveis da extração hidroalcoólica assistida por ultrassom como potência do ultrassom, composição do solvente e razão sólido/solvente. Após esta etapa, dois dos extratos, nas melhores condições de extração, foram concentrados por nanofiltração, usando três membranas de poliamida (NF270, DK e DL), em um sistema de filtração tangencial operado a 20 bar. Os processos foram avaliados quanto ao rendimento de compostos fenólicos (Folin-Ciocauteau), ácido clorogênico (CLAE-DAD) e capacidade antioxidante (DPPH e FRAP). Os rendimentos obtidos com a integração das etapas de extração e concentração, a partir de um fator de redução de volume de 2,5 foram de 559,59 ± 32,09 mg de ácido gálico equivalente/g de extrato seco para fenólicos totais, e 22,95 ± 0,35 mg de ácido clorogênico/g de extrato seco, para ácido clorogênico. Os resultados para capacidade antioxidante foram de 198,88 ± 15,15 mg Trolox equivalente/g de extrato seco, para o método de DPPH, e de 385,70 ± 0,35 mg Trolox equivalente/g de extrato seco para o método FRAP. O declínio do fluxo de permeado no processo de nanofiltração foi causado pela formação de torta, e a membrana que apresentou menor resistência ao fluxo, maior estabilidade ao longo do processo de filtração e maior retenção dos compostos de interesse, foi a DK, sendo esta a mais indicada para concentração dos extratos avaliados nesse trabalho / Abstract: The artichoke (Cynara scolymus L.) is a perennial herb belonging to the family Asteraceae. The species, rich in phenolic compounds, is originally from subtropical regions, but is also cultivated in Brazil, where most of its production is concentrated in the interior of São Paulo, and is geared to the canning industry, where external and internal bracts of plant are usually discarded as waste. The present study aimed to develop extracts rich in bioactive compounds, mainly phenolics, from artichoke waste by the study of the extraction process assisted by ultrasound and the assessment of the performance of the membrane concentration process. Initially, the variables of water-alcohol extraction assisted by ultrasound (ultrasound power, solvent composition and solid/solvent ratio) were studied, after this, two extracts in the best extraction conditions were concentrated by nanofiltration, using three polyamide membranes (NF270, DK, DL), in a tangential filtration system operated at 20 bar. Process yields were evaluated for phenolic compounds (Folin-Ciocauteau), chlorogenic acid (HPLC-DAD) and antioxidant capacity (DPPH and FRAP). The yield obtained with the integration of extraction and concentration processes, from a volume reduction factor of 2.5 were of 559.59 ± 32.09 mg of gallic acid equivalent/g dry extract for total phenolics, and 22.95 ± 0,35 mg of chlorogenic acid/g of dry extract, for chlorogenic acid. The results for antioxidant capacity were of 198.88 ± 15.15 mg Trolox equivalent/g of dry extract to the DPPH method, and 385.70 ± 0.35 mg Trolox equivalent/g of dry extract for the FRAP method. The decline of the permeate flux in nanofiltration process is due to cake formation. The membrane that showed less resistance to flow, greater stability over the filtration process and more retention of the compounds of interest was DK, which is the most suitable for concentration of the extract evaluated in this work / Mestrado / Engenharia de Alimentos / Mestra em Engenharia de Alimentos

Orientadores: Maria Angela de Almeida Meireles Petenate, Diego Tresinari dos Santos / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-27T11:45:25Z (GMT). No. of bitstreams: 1 DelCastilloTorres_RicardoAbel_M.pdf: 4457201 bytes, checksum: 2afa693e20d4497964c4faa4de811759 (MD5) Previous issue date: 2015 / Resumo: Este trabalho apresenta um estudo da aplicação do CO2 supercrítico como antissolvente em contato com a solução de ativos (SA) obtida a partir da extração de compostos de sementes de urucum (Bixa orellana L.) semi desengorduradas a fim de se obter partículas ricas em bixina. Para isso, duas etapas foram desenvolvidas. Na primeira etapa foi aperfeiçoada a técnica de obtenção da SA a partir da extração dos compostos das sementes com etanol, combinando dois equipamentos: Ultra turrax (UTurrax), que produz suspensão operado por recirculação do líquido, e o Ultrassom (USom), que produz cavitação acústica no líquido. Esta é a primeira vez que o UTurrax foi usado para obter compostos ativos das sementes semi desengorduradas de urucum. A mistura etanol e ativos formou a suspensão, denominada de SA. O objetivo nesta etapa foi obter uma SA rica em bixina e pobre em gorduras. Com esse intuito foram feitas extrações variando-se as condições de uso ou não de USom e a razão massa de solvente por massa de matéria-prima (S/F). A composição química dos extratos foi analisada em relação ao teor de bixina e fenólicos por método espectrofotométrico, enquanto que o teor de óleo foi determinado nas sementes pelo método de extração Soxhlet. O uso de USom (800 W) e S/F de 1,6 g CO2/g urucum apresentou menor teor de óleo na SA, isto é, o maior teor de óleo permaneceu nas sementes (0,49 ± 0,08 g/100 g sementes, b.u.). Houve também menor rendimento de extração (X0): 2,6 ± 0,4 g/100 g sementes (b.u.), uma vez que a extração foi mais seletiva, resultando em rendimento de extração de bixina e fenólicos de 0,19 ± 0,06 g/100 g sementes (b.u.) e 0,8 ± 0,1 g/100 g sementes (b.u.), respectivamente. Na segunda etapa, a SA foi alimentada na unidade de precipitação Antissolvente Supercrítico (SAS) com o objetivo de formar partículas e caracterizar a distribuição da bixina e fenólicos nos diversos setores no interior da coluna. Com esse intuito, foi utilizado um planejamento experimental fatorial completo com 3 variáveis (pressão, vazão de CO2 e vazão de SA) em 2 níveis (10 ¿ 12 MPa, 500 ¿ 800 g/h e 0,5 ¿ 1 mL/min, respectivamente) sem repetição, totalizando 8 experimentos. O rendimento de precipitação foi influenciado negativamente pela pressão, sendo maior (80,5 %) a 10 MPa, 500 g/h e 0,5 mL/min. Da análise de distribuição das massas das partículas na coluna de precipitação, concluiu-se que para todos os experimentos maior massa foi depositada na base da coluna (aproximadamente 40%). Da mesma forma, maior concentração de bixina foi determinada na parede da coluna (51 ± 15 g/100 g extrato), com massa de extrato igual a 8,73 g/100 g sementes para 12 MPa, 500 g/h e 1 mL/min. A concentração de fenólicos nas partículas coletadas não foi influenciada pelas variáveis de estudo. A eficiência de precipitação de bixina nesta condição foi de 88,4 %. Porém, acredita-se que a eficiência de precipitação de bixina pode ter sido ainda maior, pois, houve setores da coluna nos quais foi difícil a coleta das partículas. Por último, através do processo de precipitação na unidade SAS, foi possível a obtenção de partículas com concentração de bixina 59 vezes maior do que a concentração inicial de bixina na SA alimentada / Abstract: The following thesis consist of the development of the application of the supercritical CO2 as an anti-solvent in contact with the Active solution obtained from the extraction of semi-defatted Annatto seeds (Bixa orellana L.) to obtain particles rich in bixin. To that objective, the present thesis was developed in two stages. In the first stage it was necessary to perfect the technique for obtaining the Active solution by extracting the compounds from the seeds with ethanol. This was accomplished by combining two pieces of equipment. One of the equipment of production of suspension operated by recirculation of a liquid (Ultra-turrax) and another equipment of production of acoustic cavitations (Ultrasound) inside the liquid. To the best of the author¿s knowledge, this was the first time that the Ultra- turrax was used as a method of extraction; furthermore it was the first time that the equipment was used to obtain Active components from the semi-defatted Annatto seeds. The mixture formed by the ethanol used here as a solvent and the actives formed Suspension which is nominated as Active solution. The objective for this stage was to obtain an Active solution high in bixin with minimum oil content. The extractions were done with that purpose, varying the conditions of use or not of ultrasound and the ratio of S/F (mass of solvent/ mass of raw material). The chemical composition of extracts was analyzed in relation to percentage of bixin and phenolics using the Spectrophotometry method, while the percentage of oils from the seeds were determine by the Soxhlet extraction method. The use of ultrasound (800 W) and S/F of 1.6 presented a low percentage of oil in the Active solution; which means, the greater the percentage of oil present in the seeds (0.49 ± 0.08 %, b.u.), the lower the efficiency of extraction (X0): 2.64 ± 0.42 % (b.u.) The extraction was more selective, resulting in efficient bixin extraction and phenolics in a solution of extract of 0.19 ± 0.06 % (b.u.) and 0.75 ± 0.10 % (b.u.), respectively. In the second stage, an Active solution was inserted into the precipitation unit-SAS with the purpose of forming particles and to characterize the distribution of bixin and phenolic in diverse sectors of the column. To that objective a complete experimental factorial design with 3 variables were used (pressure, flow of CO2 and flow of Active solution) and 2 levels (10 ¿ 12 MPa, 500 ¿ 800 g/h and 0.5 ¿ 1 mL/min, respectively) without repetition, totalizing 8 experiments. The efficiency of precipitation was negatively influenced by pressure, being greater (80.5 %) to 10 MPa, 500 g CO2/h and 0.5 mL Active solution /min. From the analysis of distribution of the masses of particles in the interior of the column of precipitation, it concluded that for all the experiments, greater amount of mass was deposit in the column¿s base (approximately 40%). Great concentration of bixin was settled in the column¿s walls (51 ± 15 %), where the mass of the extract was of 8.73 % for 12 MPa, 500 g CO2/h and 1 mL Active solution /min. The concentration of phenolics in the particles collected was not influenced by the variables of study. The precipitation efficiency of bixin in this condition was 88.4 %. However, its believe that the efficiency of bixin precipitation it could had been greater, because there were areas of the column that it was impossible to collect precipitated particles. Lastly, through the precipitation process in the SAS-unit, was possible to obtain particles with concentration of bixin 59 times greater than the initial concentration of bixin in Active solution inserted in the SAS-unit / Mestrado / Engenharia de Alimentos / Mestre em Engenharia de Alimentos

Alterações na coluna vertebral de cães são comumente encontradas na rotina clínica e cirúrgica veterinária. Existem poucos estudos sobre a anatomia ultrassonográfica musculoesquelética do segmento toracolombar e lombar da coluna vertebral normal de cães. O objetivo deste trabalho foi comparar a anatomia ultrassonográfica musculoesquelética normal dos segmentos vertebrais avaliados com imagens obtidas pela ressonância magnética, tomografia computadorizada e peças anatômicas visando demonstrar a sua capacidade de identificação de estruturas. A varredura ultrassonográfica permitiu a visibilização da musculatura da região, processos articulares, processos espinhosos, ligamentos interespinhosos e ligamento amarelo na janela lombossacra. A tomografia computadorizada forneceu imagens com melhor detalhamento ósseo quando comparada ao exame ultrassonográfico. A ressonância magnética de baixo campo permitiu a identificação das mesmas estruturas que o exame ultrassonográfico acrescido da identificação do líquido cefalorraquidiano, processos transversos e melhor detalhamento dos discos intervertebrais e medula espinhal. Com o conhecimento da anatomia ultrassonográfica da região, acredita-se que lesões musculares e ligamentares possam ser identificadas. Vale salientar que em regiões onde a tomografia computadorizada e a ressonância magnética não estejam acessíveis a ultrassonografia da região pode ser uma boa alternativa para identificar possíveis alterações não visibilizadas ao exame radiográfico, ou complementar o mesmo. / Changes in the spine of dogs are usually found in clinical and surgical practices. There are few studies on musculoskeletal ultrasound anatomy of thoracolumbar and lumbar segments of the normal spine of dogs. The aim of this study was to compare normal musculoskeletal ultrasound anatomy of the vertebral segments evaluated with images obtained by magnetic resonance imaging, computed tomography and anatomical parts in order to establish its ability to identify structures. The ultrasound scan allowed visualization of the muscles of the region, articular processes, spinous process, interspinous ligament and yellow ligament in the lumbosacral window. Computed tomography provide images with better bone details when compared to ultrasound examination. Low field magnetic resonance imaging allowed the identification of the same structures as the ultrasound examination plus the identification of cerebrospinal fluid, transverse processes and better detail of the intervertebral discs and spinal cord. Knowledge of ultrasound anatomy of the region may lead to detection of muscle and ligament injuries. It is emphasized that in areas where CT and MRI are not accessible, ultrasonography of the region can be a good alternative to identify possible alterations not visualized by radiographic examination or supplement it.

A articulação do cotovelo é complexa e tem grande relevância clínica nos atendimentos aos pequenos animais. Esta região já foi bem explorada em pesquisas anteriores pelos métodos radiográficos e tomográficos, porém, ainda há poucos estudos relacionados à ultrassonografia. O objetivo deste estudo foi descrever a anatomia ultrassonográfica da articulação do cotovelo de cães e comparar com os achados das demais modalidades de diagnóstico por imagem. Dessa forma, demonstrar a capacidade da técnica de identificar as principais estruturas desta articulação e seu potencial uso em regiões onde a tomografia computadorizada e ressonância magnética não estiverem disponíveis. Dez animais com peso entre 5 kg e 15 kg foram radiografados e selecionados para o estudo ultrassonográfico. O protocolo para a descrição ultrassonográfica foi estabelecido dividindo-se as áreas da articulação em porções proximal, média e distal; e faces lateral, cranial, medial e caudal. A avaliação foi realizada nos planos longitudinais, transversais e oblíquos e as estruturas musculoesqueléticas foram descritas conforme sua arquitetura, ecogenicidade e ecotextura. Como parte complementar deste estudo um dos animais foi submetido aos exames de tomografia computadorizada e ressonância magnética. Em relação às estruturas visibilizadas, o exame ultrassonográfico foi eficiente para as análises muscular, tendínea e ligamentar. Os contornos ósseos e regiões sede de alterações de importância clínica, como processo coronóide medial da ulna e processo ancôneo também foram visibilizados, porém de forma limitada. O conhecimento prévio da anatomia ultrassonográfica normal da articulação do cotovelo, assim como das vantagens e limitações da técnica, permitem a realização de estudos subsequentes, relacionados às possíveis identificações de alterações musculoesqueléticas. / The elbow is a complex joint and has a great clinical relevance at the small animal medicine care. Previous research of this region has been explored using radiographic and tomographic methods, however, there are few studies related to ultrasonography. The aim of this study was to describe the ultrasonographic anatomy of the elbow joint of dogs and compare it with the findings of other types of diagnostic imaging. Thus, demonstrate the ability of this technique to identify the main structures of this joint and its potential use in regions where computed tomography and magnetic resonance imaging are not available. Ten animals weighing between 5 kg and 15 kg were radiographed and selected to the ultrasonographic study. The protocol was established for the ultrasonographic description dividing the articular areas in proximal, middle and distal; and lateral cranial, medial, and caudal faces. The approach was made in longitudinal, transverse and oblique planes and the musculoskeletal structures were described according to the architecture, echogenicity and echotexture. Computed tomography and magnetic resonance scans were made in one animal as an additional part of this study. Regarding visualized structures, the ultrasonography was efficient for muscle, tendon and ligament analysis. Bone contours and regions that have clinical significance such as medial coronoid process and anconeus process were identified, but with limited access. Prior knowledge of the normal sonographic anatomy of the elbow joint as well as the technical advantages and limitations allow pursuing further studies related to the possible identification of musculoskeletal disorders.

Lesões em coluna vertebral estão intimamente relacionadas a alterações neuromusculares, de modo que pela sensibilidade dolorosa e restrição da movimentação podem levar a alterações musculares como assimetrias e atrofias. Por outro lado, a musculatura enfraquecida pode predispor a lesões vertebrais. Esse trabalho buscou investigar ultrassonograficamente a presença de alterações musculoesqueléticas em cães com suspeita clínica de alterações nos segmentos toracolombar e lombar da coluna vertebral, confirmada ou não, pelo exame radiográfico. Além da análise descritiva, o grau de atrofia muscular foi quantificado através da mensuração da espessura e área da secção transversal do músculo Multifidus dorsi no nível de cada vértebra entre T13 e L7. Análises descritivas e quantitativas foram realizadas para 30 cães hígidos e 30 sintomáticos, levando em conta a presença de lesões, escore de condição corporal e tempo de evolução do quadro (para animais com histórico de lesão). O exame ultrassonográfico possibilitou a avaliação qualitativa de superfícies ósseas dos processos articulares e espinhosos, ligamentos supraespinhoso, interespinhoso e flavo e grupos musculares que envolvem o Multifidus dorsi e Longissimus dorsi, bem como alterações de ecogenicidade e irregularidades em superfícies ósseas e fibras musculares. Para análise dos dados foi utilizado um modelo com três fatores, considerando presença de lesão, cronicidade e escore como efeitos fixos e o bloco idade-sexo-porte como efeito aleatório. A espessura do Multifidus dorsi foi menor em animais com lesão do que em cães hígidos e naqueles cães que apresentaram lesão crônica, quando comparado com animais sem histórico de lesão, não variando entre cães com escore adequado ou obesos. Houve menores valores de área da secção transversal para animais com lesão crônica e uma correlação forte entre mensurações de área dos lados direito e esquerdo para uma mesma vértebra. A ultrassonografia mostrouse um método interessante para estimativa da atrofia muscular com base na espessura do Multifidus dorsi, sobretudo no nível de T13, L1 e L3. A utilização da ultrassonografia musculoesquelética da coluna vertebral neste trabalho apresentou impacto positivo em 45% dos casos, seja por concomitantemente contribuir para o diagnóstico diferencial e influenciar na conduta em 17% dos casos ou por exclusivamente influenciar na conduta em 28% deles. O emprego deste método não afetou o diagnóstico em 55% dos casos. Portanto, é um método promissor para ser empregado na investigação musculoesquelética da coluna vertebral toracolombar e lombar, em casos específicos. / Spinal injuries are closely related to neuromuscular changes, so that pain and movement impairment can lead to muscle changes such as asymmetries and atrophies. On the other hand, the weakened muscles may predispose to vertebral injuries. This work used the ultrasound to investigate the presence of musculoskeletal alterations in the thoracolumbar and lumbar segments of the canine spine, associated or not to radiographic findings. In addition to the descriptive analysis, the muscle atrophy was quantified by measuring the thickness and crosssectional area (CSA) of the Multifidus dorsi muscle at the level of each vertebra between T13 and L7. Descriptive and quantitative analyzes were performed for 30 healthy and 30 symptomatic dogs, taking into account the presence of lesions, body condition score and chronicity (for animals with a history of injury). Ultrasound examination allowed the qualitative evaluation of bone surfaces of articular and spinal processes, supraspinatus, interspinous and flavum ligaments and paraspinal muscle groups involving Multifidus dorsi and Longissimus dorsi, as well as changes in echogenicity and irregularities in bone surfaces and muscle fibers. For data analysis a model with three factors was used, considering presence of injury, chronicity and score as fixed effects and the block age-sex-size as random effect. Multifidus dorsi thickness was lower in animals with lesions than in healthy dogs and in dogs with chronic lesions when compared to animals with no lesion history. This parameter did not vary between dogs with adequate score or obese dogs. There were lower CSA values for animals with chronic lesions and a strong correlation between CSA measurements on the right and left sides for the same vertebra. Ultrasonography was an interesting method to estimate muscle atrophy based on the Multifidus dorsi thickness, especially at the level of T13, L1 and L3. The use of the musculoskeletal ultrasonography in this study had a positive impact in 45% of the cases, either by contributing to the differential diagnosis and influencing the conduct in 17% of the cases or by exclusively influencing the conduct in 28%. The use of this method did not affect the diagnosis in 55% of the cases. Therefore, it is a promising method to be used in musculoskeletal investigation of the spine in specific cases.

L'objectif de ce travail était de développer des méthodes pour permettre une évaluation in vivo plus robuste du réseau vasculaire dans la tumeur par imagerie de contraste ultrasonore. Trois aspects de l'analyse de donnée ont été abordé: 1) la régression des modèles paramétriques de flux sur les données de puissance linéaire, 2) la compensation du mouvement 3) l’évaluation d’une méthode de clustering pour identifier les hétérogénéités dans les tumeurs. Un modèle multiplicatif est proposé pour décrire le signal DCE-US. Une méthode de régression en est dérivée. La caractérisation du signal permet la mise au point d’une méthode de simulation de séquences 2D+T. La méthode de régression permet une diminution de la variabilité des paramètres de flux fonctionnels extraits, sur données simulées expérimentales. La méthode de simulation est appliquée pour évaluer une méthode combinant estimation du mouvement et estimations des paramètres micro-vasculaires dans un unique problème mathématique d'optimisation. Cette nouvelle méthode présente en plus l'avantage d'être indépendante de l'opérateur. Il est montré que dans une large majorité des cas l'estimation du mouvement est meilleure avec la nouvelle méthode qu'avec une méthode de références. Une méthode de clustering est adaptée et évaluée sur données DCE-US simulées et in-vivo. Elle permet de détecter des hétérogénéités dans la structure vasculaire des tumeurs. Les méthodes développées permettent d'améliorer l’évaluation du réseau microvasculaire par DCE-US grâce à une description rigoureuse du signal, à la mise au point d'outil diminuant l'intervention de l'opérateur et la prise en compte de l'hétérogénéité du réseau vasculaire. / This work aimed to develop methods to robustly evaluate in vivo functional flow within the tumor vascular network with Dynamic contrast-enhanced ultrasound (DCE-US). Three aspects of data analysis were addressed: 1) insuring best fit between parametric flow models and the experimentally acquired echo-power curves, 2) compensating sequences for motion and 3) evaluating a method to discriminate between tissues with different functional flow. A multiplicative model is proposed to describe the DCE-US signal. Based on this model, a new parametric regression method of the signal is derived. Characterization of the statistical properties of the noise and signal is also used to develop a new method simulating contrast-enhanced ultrasound 2D+t sequences. A significant decrease in the variability of the functional flow parameters extracted according to the new multiplicative-noise fitting method is demonstrated using both simulated and experimentally-acquired sequences. The new sequence simulations are applied to test a method combining motion estimation and flow-parameter estimation within a single mathematical framework. Because this new method does not require the selection of a reference image, it reduces operator intervention. Tests of the method on both simulations and clinical data and demonstrate in a majority of sequences a more accurate motion estimation than the commonly used image registration method. Finally, a non-parametric method for perfusion curve clustering is evaluated on 2D+t sequences. The aim of this method is to regroup similar filling patterns without a priori knowledge about the patterns. The method is tested on simulated and on pre-clinical data.

Contexte : L'obésité est considérée par l'OMS comme une « épidémie » mondiale en raison de l'essor de sa prévalence et de ses conséquences sur la santé. Chez les patientes enceintes, son impact semble tout aussi préoccupant et sa prévalence en France atteint actuellement 10%. Certaines complications de l'obésité chez la femme enceinte ont été peu étudiées et notamment le lien particulier avec la macrosomie fœtale.Objectifs : Mieux appréhender la prise en charge des patientes enceintes obèses et de certaines complications qui en découlent.Méthodes : Trois séries de données différentes ont servi pour répondre à différentes questions sur la thématique de l'obésité et de la macrosomie. 1) Une évaluation de la faisabilité et de la qualité d'une échographie obstétricale du 2ème trimestre chez les patientes obèses a été réalisée via une étude mono centrique avec recueil prospectif des données. 2) Une étude des facteurs de risques de complications maternelles en cas d'accouchement d'un enfant macrosome, indépendamment de l'obésité maternelle et du poids de naissance de l'enfant a été menée sous la forme d'une étude prospective de cohorte d'enfant de plus de 4000g dans deux maternités d'Ile de France. 3) Enfin, une comparaison de la relation entre les complications maternelles de la grossesse et /ou néonatales et l'obésité a été menée entre la France (4 maternités de type III) et le Québec (données issues d'une étude randomisée dans toute la province) entre 2009 et 2011 via une étude comparative de deux échantillons transversaux de femmes enceintes (26 973 accouchements en France et 83 545 accouchements au Québec). Résultats : 1) Une échographie du deuxième trimestre de la grossesse chez une population obèse est possible, avec un taux de réussite en une fois de 70,4 %, (versus 82% ; p=0,08). Les facteurs d'amélioration de ce taux étaient : passer plus de temps lors de l'échographie (p=0,03), déplacer le fœtus de sorte que son dos soit en position latérale ou postérieure (p=0,01), et échographie réalisée par des échographistes expérimentés (p=0,03). Néanmoins, la qualité des images reste significativement moins bonne dans la population obèse (p=0,001). 2) La survenue de complications maternelles lors de la tentative d'accouchement vaginal d'un enfant de plus de 4000 g est de 6%. Les facteurs de risque de complications maternelles, outre le poids de naissance de l'enfant (p=0,004, Risque attribuable (RA)=10%), sont l'origine asiatique de la mère (p=0,04 ; RA=3%), une durée longue du travail (>10h) (p=0,02 ; RA=12%), et une césarienne au cours du travail (p=0,004 ; RA=17%). Les patientes multipares ayant déjà accouché par voie vaginale d'un enfant macrosome avaient un risque diminué de complications maternelles (p=0,03). 3) La prévalence de l'obésité était de 9,1% en France et 16,8% au Québec (p<0,001). L'obésité était associée de manière statistiquement significative (p<0,0001), à la fois en France et au Québec, à un risque accru de diabète gestationnel, de troubles hypertensifs de la grossesse, de prééclampsie, de mort fœtale in utero, d'accouchement par césarienne et de macrosomie. L'association était différente en France et au Québec (p interaction <0,005), pour la survenue du diabète gestationnel, de complications hypertensives de la grossesse et pour la macrosomie, avec une augmentation plus importante des complications avec l'IMC au Québec par rapport à la France.Conclusion : La compréhension de certaines complications inhérentes à l'obésité (complications médicales de la grossesse, faisabilité et qualité du dépistage échographique, complications obstétricales) est améliorée par les résultats de cette thèse. / Background: According to WHO, obesity is considered as an "epidemic" condition due to the global growth of its prevalence and its impact on patient health. For pregnant patients, its impact seems equally worrying and its prevalence is now reaching 10% in France. Some complications of obesity in pregnant women have been little studied and particularly the special link with fetal macrosomia.Objectives: To better understand care and obstetric outcome of obese pregnant patients as well as some of their complications such as fetal macrosomia.Methods: Three different sets of data were used to deal with questions regarding obesity and macrosomia. 1) Assessment of feasibility and quality of second trimester ultrasound scan in obese patients was performed through a mono centric case-control study with prospective data collection. 2) A study of risk factors for maternal complications in case of the delivery of a macrosomic child, regardless of maternal obesity and child's birth weight, was conducted as a prospective cohort study including children with birthweight above 4000g in two “Ile de France” maternity wards. 3) Finally, a comparison of the relationship between maternal and/or neonatal complications of pregnancy and obesity was conducted in France (4 type III maternity wards) and in Quebec (data from a randomized study throughout the province) between 2009 and 2011 through a comparative study of two cross-sectional samples of pregnant women (26,973 births in France and 83,545 births in Quebec).Results: 1) Second trimester ultrasound scan in obese pregnant women is feasible, with a success rate of 70.4% (versus 82%; p=0.08). Factors of improvement were: to spend more time at ultrasound (p=0.03), to move the fetus so that its back is in lateral or posterior position (p=0.01) and when ultrasound was performed by experienced sonographers (p=0.03). However, the quality of the image remains significantly lower in the obese population (p=0.001). 2) The occurrence of maternal complications, when attempting vaginal birth of a child of more than 4000g, was 6%. Beyond childbirth weight (p=0.004, attributable risk (AR) = 10%), the risk factors of maternal complications were Asian ethnicity (p=0.04; AR=3%), prolonged labor (> 10h) (p=0.02; AR=12%), and caesarean section during labor (p=0.004; AR=17%). Multiparous women with a previous vaginal delivery of a macrosomic child had a lower risk of maternal complications (p=0.03). 3) The prevalence of obesity was 9.1% in France and 16.8% in Quebec (p <0.001). Obesity was significantly (p <0.0001) associated with, both in France and in Quebec, an increased risk of gestational diabetes, hypertensive disorders of pregnancy, preeclampsia, stillbirth, cesarean delivery and macrosomia. The strength of the association was different in France and Quebec (p of interaction <0.005) for the occurrence of gestational diabetes, hypertensive complications of pregnancy and macrosomia, with a larger increase in complications with body mass index in Quebec compared to France.Conclusion: Understanding some inherent complications of obesity (medical complications of pregnancy, feasibility and quality of ultrasound screening, obstetric complications) is enhanced by the result of this work.