Objectif. L’activité physique a des bénéfices sur la santé mentale des personnes vivant avec des troubles psychotiques. L’effort aérobie de type continue étant l’intervention la plus populaire dans la littérature, certaines études ont également étudié le type d’effort de haute intensité par intervalles, mais n’ont pas observé ses effets à long terme. La présente étude vise premièrement à observer le maintien des bénéfices auprès de personnes ayant des troubles psychotiques, après une intervention de six mois de haute intensité par intervalles. Deuxièmement, elle vise à déterminer les prédicteurs de participation à la pratique d’activité physique. Méthodes. Soixante-six sujets (37.9% de femmes, 30.73 ± 7.23 ans) diagnostiqués avec un trouble psychotique selon le DSM-5 ont participé à une intervention supervisée de haute intensité par intervalles de course sur tapis, durant six mois, à raison de deux séances de 30 minutes par semaine. Après cette intervention, il a été offert aux sujets un accès gratuit aux installations ou se sont déroulées les séances pendant à nouveau six mois, sans supervision. Les sujets ont été évalués avant et après l’intervention, puis six mois après l’arrêt de la supervision, soit 12 mois après le premier temps de mesure. La symptomatologie (PANSS), le fonctionnement global (GAF) et social (SOFAS) ont été évalués. Les scores des questionnaires mentionnés ci-dessus ont été analysées statistiquement par des modèles mixtes linéaires et des ANOVA à une voie. Résultats. Les résultats ont montré un maintien de l’impact positif de l’intervention sur les symptômes négatifs (p = 0,004) et globaux (p = 0,01). Les facteurs prédicteurs de la participation aux séances d’activité physique ont montré que les individus ayant participé à moins de 64% des séances sont ceux ayant un moins bon fonctionnement global (GAF : p = 0,02) et social (SOFAS : p ˂ 0,001) et des symptômes plus sévères (PANSS : négatifs : p = 0,02 ; positifs : p = 0,01 ; globaux : p = 0,04). Conclusion. Le maintien des bénéfices n’a été observé qu’au niveau des symptômes négatifs, ce qui implique des stratégies supplémentaires dans l’élaboration de l’intervention et ses modalités. De plus, nos analyses prédictives révèlent qu'une amélioration du fonctionnement social et global, ainsi qu'une réduction de la sévérité des symptômes, sont associées à une participation accrue à l'activité physique chez nos participants. / Aims. Physical activity has mental health benefits for people with psychotic disorders. Continuous aerobic exercise being the most popular intervention in the literature, some studies have also investigated high-intensity interval training but have not investigated its long-term effects. This study had two aims. First, to observe whether the benefits of a six-month high intensity interval training intervention could be maintained among people with psychotic disorders. Second, to determine the predictors of participation in physical activity participation. Methods. Sixty-six subjects (37.9% women, 30.73 ± 7.23 years old) diagnosed with psychotic disorder according to DSM-5 participated in a supervised six-month high-intensity interval treadmill running intervention : twice per week, 30 minutes per session. After the intervention, subjects were offered free access to the facilities where the sessions were held for another six months without supervision. The subjects were evaluated before and after the intervention, and six months after the end of supervision, which was 12 months after the first measurement. Symptomatology (PANSS), global (GAF) and social (SOFAS) functioning were evaluated. The scores of the above-mentioned questionnaires were statistically analyzed using linear mixed models and one-way ANOVA. Results. The results showed a maintenance of the positive impact of the intervention on negative (p = 0.004) and global (p = 0.01) symptoms only. Predictors of participation in physical activity sessions showed that individuals who participated in less than 64% of the sessions had poorer global functioning (GAF: p = 0.02) and social functioning (SOFAS : p ˂ 0,001) and more severe symptoms (PANSS: negative: p = 0.02; positive: p = 0.01; global: p = 0.04). Conclusion. The maintenance of benefits was only observed in terms of negative symptoms, which implies the need for additional strategies in the development and implementation of the intervention. In addition, the prediction analyses of participation in physical activity demonstrated that individuals with better global and social functioning and less severe symptoms are more likely to practice physical activity.

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Contactless ultrasonic power transfer (UPT), using piezoelectric transducers, is based on transferring energy using acoustic waves, in which the waves are generated by an acoustic source or transmitter and then transferred through an acoustic medium such as water or human tissue to a sensor or receiver. The receiver then converts the mechanical strain induced by the incident acoustic waves to electricity and delivers to an electrical load, in which the electrical power output of the system can be determined. The execution and efficiency of this technology can be significantly enhanced through patterning, focusing, and localization of the transmitted acoustic energy in space to simultaneously power pre-determined distributed sensors or devices. A passive 3D-printed acoustic hologram plate alongside a single transducer can generate arbitrary and pre-designed ultrasound fields in a particular distance from the hologram mounted on the transmitter, i.e., a target plane. This dissertation presents the use of these simple, cost-effective, and high-fidelity acoustic holograms in UPT systems to selectively enhance and pattern the electrical power output from the receivers. Different holograms are numerically designed to create single and multi-focal pressure patterns in a target plane where an array of receivers are placed. The incident sound wave from a transmitter, after passing through the hologram, is manipulated, hence, the output field is the desired pressure field, which excites the receivers located at the pre-determined focal points more significantly. Furthermore, multi-functional holograms are designed to generate multiple images at different target planes and driving frequencies, called, respectively, multi-image-plane and multi-frequency patterning holograms. The multiple desired pressure distributions are encoded on the single hologram plate and each is reconstructed by changing the axial distance and by switching the frequency. Several proof-of-concept experiments are performed to verify the functionality of the computationally designed holograms, which are fabricated using modern 3D-printers, i.e., the desired wavefronts are encoded in the hologram plates' thickness profile, being input to the 3D-printer. The experiments include measurement of output pressure fields in water using needle hydrophones and acquisition of receivers' voltage output in UPT systems. Another technique investigated in this dissertation is the implementation of acoustic impedance matching layers deposited on the front leading surface of the transmitter and receiver transducers. Current UPT systems suffer from significant acoustic losses through the transmission line from a piezoelectric transmitter to an acoustic medium and then to a piezoelectric receiver. This is due to the unfavorable acoustic impedance mismatch between the transducers and the medium, which causes a narrow transducer bandwidth and a considerable reflection of the acoustic pressure waves at the boundary layers. Using matching layers enhance the acoustic power transmission into the medium and then reinforce the input as an excitation into the receiver. Experiments are performed to identify the input acoustic pressure from a cylindrical transmitter to a receiver disk operating in the 33-mode of piezoelectricity. Significant enhancements are obtained in terms of the receiver's electrical power output when implementing a two-layer matching structure. A design platform is also developed that can facilitate the construction of high-fidelity acoustically matched transducers, that is, the material layers' selection and determination of their thicknesses. Furthermore, this dissertation presents a numerical analysis for the dynamical motions of a high-intensity focused ultrasound (HIFU)-excited microbubble or stable acoustic cavitation, which includes the effects of acoustic nonlinearity, diffraction, and absorption of the medium, and entails the problem of several biomedical ultrasound applications. Finally, the design and use of acoustic holograms in microfluidic channels are addressed which opens the door of acoustic patterning in particle and cell sorting for medical ultrasound systems. / Doctor of Philosophy / This dissertation presents several techniques to enhance the wireless transfer of ultrasonic energy in which the sound wave is generated by an acoustic source or transmitter, transferred through an acoustic medium such as water or human tissue to a sensor or receiver. The receiver transducer then converts the vibrational energy into electricity and delivers to an electrical load in which the electrical power output from the system can be determined. The first enhancement technique presented in this dissertation is using a pre-designed and simple structured plate called an acoustic hologram in conjunction with a transmitter transducer to arbitrarily pattern and shape ultrasound fields at a particular distance from the hologram mounted on the transmitter. The desired wavefront such as single or multi-focal pressure fields or an arbitrary image such as a VT image pattern can simply be encoded in the thickness profile of this hologram plate by removing some of the hologram material based on the desired shape. When the sound wave from the transmitter passes this structured plate, it is locally delayed in proportion to the hologram thickness due to the different speed of sound in the hologram material compared to water. In this dissertation, various hologram types are designed numerically to implement in the ultrasonic power transfer (UPT) systems for powering receivers located at the predetermined focal points more significantly and finally, their functionality and performances are verified in several experiments. Current UPT systems suffer from significant acoustic losses through the transmission from a transmitter to an acoustic medium and then to a receiver due to the different acoustic impedance (defined as the product of density and sound speed) between the medium and transducers material, which reflects most of the incident pressure wave at the boundary layers. The second enhancement technology addressed in this dissertation is using intermediate materials, called acoustic impedance matching layers, bonded to the front side of the transmitter and receiver face to alleviate the acoustic impedance mismatch. Experiments are performed to identify the input acoustic pressure from a transmitter to a receiver. Using a two-layer matching structure, significant enhancements are observed in terms of the receiver's electrical power output. A design platform is also developed that can facilitate the construction of high-fidelity acoustically matched transducers, that is, the material layers' selection and determination of their thicknesses. Furthermore, this dissertation presents a numerical analysis for the dynamical motions of a microbubble exposed to a high-intensity focused ultrasound (HIFU) field, which entails the problem of several biomedical ultrasound applications such as microbubble-mediated ultrasound therapy or targeted drug delivery. Finally, an enhancement technique involving the design and use of acoustic holograms in microfluidic channels is addressed which opens the door of acoustic patterning in particle and cell sorting for medical ultrasound systems.

Introduktion: Fysisk aktivitet har stor betydelse för en god hälsa när vi åldras. Trots det är en stor andel av äldre personer stillasittande. Brist på tid och obehagliga upplevelser ses som hinder till träning. Högintensiv träning kan utföras på kort tid och kan ge större hälsofördelar än medelintensiv träning. Däremot har högintensiv träning upplevts för ansträngande och olämpligt för en stillasittande population. En negativ affektiv respons kan minska följsamheten i träningen vilket belyser vikten av att anpassa högintensiv träning för äldre. Forskning om upplevelser av en anpassad högintensiv träningsregim saknas i dagsläget. Syfte: Att beskriva upplevelser av supramaximala cykelintervaller, träningsmotivation och fortsatta träningsvanor hos informanterna, sex månader efter genomförd intervention.  Metod: I studien användes en kvalitativ induktiv ansats. Sex månader efter en träningsintervention genomfördes semi-strukturerade intervjuer. Tio av de intervjuerna har analyserats i denna studie, med deltagare som hade genomfört anpassade supramaximala intervaller på cykel två gånger per vecka under tolv veckor. Materialet analyserades med kvalitativ innehållsanalys. Resultat: Analysen av intervjuerna resulterade i fem kategorier: Träningen fyllde en viktig plats i livet, Att uppleva kroppen genom träning, Gemenskap som ger drivkraft, Träningen som stärkande upplevelse, och Att förändra eller falla in i gamla vanor. Konklusion: Supramaximala anpassade intervaller i grupp är en träningsform som verkar passa äldre personer. Träningen har upplevts lättsam och tidseffektiv. Gruppen har varit viktig och bidragit med glädje och motivation i träningen. Trots ökad motivation till träning har många fallit tillbaka i gamla vanor efter träningsperioden. Individuellt motstånd möjliggör träning på rätt intensitet i en grupp med blandad träningsvana. Dessa insikter kan komma att bli viktiga för att implementera träningsformen.

Aging, obesity and increased waist circumference (WC) increases risk for metabolic syndrome (MetS). MetS is a cluster of symptoms (elevated WC, triglycerides, blood pressure, fasting glucose, and decreased high-density lipoprotein cholesterol [HDL-C]) increasing risk for chronic disease. Low-energy dense (LED) diets, emphasizing whole food eating patterns, have not been examined in combination with moderate (mod)/high-intensity physical activity (PA) or dietary protein levels to determine their impact on changes in body weight (BW) and WC in premenopausal, abdominally obese women. PURPOSE: To determine the effect of two 16-wk diet and PA interventions, differing in protein intake, on BW, WC, MetS risk factors, dietary patterns, energy density (ED), and min of Mod-Hi PA. METHODS: Healthy, abdominally obese (WC≥80cm) women (n=38; 34±10y) were randomly assigned to either a 15 or 25% (+18 g/d whey protein) en from protein diet. Individualized LED diets plans decreased energy intake (EI) by ~300kcal/d; PA 5 d/wk (30-60 min/d) consisted of supervised, high-intensity Zumba classes 3d/wk (≥65%HRmax; ≥6METs) and self-selected mod-intensity PA (≥3METs) 2d/wk. Servings of fruits/vegetables, whole grains, and low-fat/fat-free dairy (LFD), fiber, high calorie beverages (BEV), ED, and PA were monitored before (T1), during (T2) and after (T3) the intervention using repeated measures ANOVA. Bonferroni simultaneous testing procedure was used in analysis of multiple comparisons. RESULTS: At T1, groups did not differ in dietary patterns, PA, BW, WC, or MetS risk. Groups responded similarly to the interventions so data were combined, with BW and WC decreasing (p<0.0001) by -4.8±2.7kg and -7.1±3.6cm, respectively. Comparing T1 vs. T2, there were increases (p<0.0001) in fruits/vegetables, (Δ=+1.5 ser/d), whole grains (Δ=+1.0 ser/d), LFD (Δ=+0.5 ser/d), fiber (Δ=+5.7g/1000 kcal), and decreases in BEV (Δ=-165 kcal/d) and ED (Δ=-0.55 kcal/g). During the intervention high-intensity Zumba PA was 87min/wk; total min of all mod-intensity PA increased by 75 min/d (p<0.0001); VO2max improved from 29.3±4.7 (T1) to 34.4±5.3 (T3) mL/kg/min (p<0.0001). Triglycerides significantly decreased (-24±52 mg/dl; p=0.006), no other significant changes occurred in MetS risk factors. Exploratory analysis indicated that increases in fruits/vegetables and LFD, and decreases ED were associated with BW loss, while increases in whole grains, fiber, LFD, and min/wk of high-intensity PA (Zumba) were associated with WC reductions. CONCLUSION: For abdominally obese women, an intervention focused on LED foods and high-intensity PA significantly reduced BW and WC and improved dietary patterns regardless of protein intake. Helping clients identify a few key factors that positively promote reductions in BW and WC may improve weight loss success, while reducing MetS risk factors. / Graduation date: 2012

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

A evidência científica da cariologia atual vem apontando para a promoção de saúde bucal, técnicas preventivas, diagnóstico precoce da doença cárie e suas lesões nos elementos dentais, remineralização de lesões de cárie incipientes e a intervenção restauradora célere como procedimentos minimamente invasivos. Durante o ato de remoção de lesão de cárie, é comum remover-se inadvertidamente também tecido dental hígido durante a fase final, por ser um tanto quanto difícil precisar clinicamente os limites entre tecido dental comprometido e tecido dental viável. Usando-se a tecnologia com lasers de Érbio, uma dica clínica subjetiva é a mudança da percepção do som emitido pela ablação do tecido dental ao passar-se de substrato cariado para hígido (de grave para agudo), como uma forma adicional de saber que a ablação naquele ponto deve ser interrompida. Este estudo visa classificar estas diferenças sonoras em dentina e torná-las um parâmetro objetivo para odontologia de mínima intervenção ao usar-se lasers de Érbio. Para tanto, foram realizadas três fases do estudo: primeiramente, utilizaram-se vinte dentes posteriores humanos, sendo dez cariados e dez hígidos. A dentina foi irradiada com laser de Er:YAG sob os mesmos parâmetros, distância e refrigeração e um microfone monodirecional foi posicionado a 10cm da área operatória para captação e gravação dos sons produzidos pela ablação ao se operar tanto em dentina hígida quanto cariada. Dez pulsos por arquivo foram então analisados em um software (200 análises). Foram encontradas diferenças entre os padrões sonoros produzidos dos grupos cariados e hígidos e encontrado um ponto de corte para estas freqüências sonoras, que seria testado a seguir. Em outra segunda etapa, foi desenvolvido, testado e aplicado um software limitador de freqüência sonora, para que, em tempo real, avisasse o operador se o tecido dentinário que estava sendo ablacionado pelo laser de Érbio (Er:YAG e Er,Cr:YSGG) era cariado ou viável, e este evitasse o sobrepreparo, ou seja, desgastar o tecido sadio inadvertidamente, de acordo com os preceitos de mínima intervenção. Finalmente, em uma terceira etapa, o método foi validado através dos critérios visual-tátil e de fluorescência a laser; ilustrações representativas dos espécimes testados foram obtidas através de microscopia de luz e de microscopia eletrônica de varredura. Conclui-se que o som da ablação dentinária é um parâmetro objetivo que pode ser utilizado como um recurso adicional de orientação no processo de remoção de dentina cariada com lasers de Érbio e que a ferramenta desenvolvida para tanto foi efetiva, devendo ser aprimorada. O método foi validado exitosamente pelos critérios propostos. / Studies in cariology have been struggling for the development of health promotion, caries prevention techniques, precocious diagnoses of lesions, re-mineralization of incipient carious lesions and early restorative intervention with minimally invasive procedures. When removing caries lesion, healthy dental structure is often removed inadvertently during its final phase, for being quite difficult to clinically precise the limits between viable and decayed dental tissues. With laser technologies, a subjective clinical hint, often used to indicate when tissue ablation should be stopped is that different sounds are perceptive whether in carious (bass) or in healthy (treble) dental structure; when sound produced by ablation turned treble it would mean that healthy tissue was reached. This study aims to classify those audio differences and to turn them into objective parameters for a conservative operative dentistry with minimally invasive tissue removal when using Erbium lasers. For so, three phases of this study were needed: at first, twenty freshly extracted posterior human teeth were used (10 decayed and 10 sound teeth). Dentine was irradiated with Er:YAG laser under the same parameters, distance and refrigeration and a mono directional microphone was set 10cm far from the operative area in order to capture and record the ablation produced sounds when working either on carious or healthy dentine. Ten pulses per file were then analyzed in a computer software (200 analyses).It was permitted to draw differences between decayed and healthy produced sounds and also to establish a cut-off value for these sound frequencies, that would be tested later on. On a second phase, a piece of software which was able to border the sound frequency was then developed and tested. This tool was meant to warn the operator, in real-time basis, if sound dentine was reached, while it was ablated by Erbium lasers (either Er:YAG or Er,Cr:YSGG) and so one could avoid over-treatment, which means not to remove sound tissue inadvertently, according to minimal intervention dentistry concepts. Finally, on a third part of the study, the proposed guiding method for dentine caries removal was validated through visuo-tactile and laser fluorescence criteria. Representative illustrations of the tested specimens were obtained by light microscopy and scanning electron microscopy. As a conclusion, audio analysis came out to be a technical reliable objective parameter to determine whether laser ablated dentine substrates are decayed or sound; therefore it can be proposed as an additional conservative parameter to guide the clinician during dentine caries removal process, and that the tool developed for so was effective and should be sharpened. This method was successfully validated by the proposed criteria.