Les myopathies sont une maladie rare qui entraine une déficience musculaire. Il apparait que la plupart des myopathies présentent une modification dans la biodistribution et la concentration des collagènes. Le diagnostic actuel de ces maladies repose sur l’étude de protéines déficientes par des outils de biologie moléculaire dont les résultats sont incertains. Nous proposons de développer la spectro-imagerie IRTF pour différencier les cinq principaux types de collagène dans le tissu conjonctif musculaire. Pour cela, nous avons appliqué deux méthodes : la déconvolution spectrale de l’amide I et la détermination des coefficients d’extinction anisotropes des fibres. Nous avons ensuite mis au point une matrice synthétique mimant la composition moléculaire d’un tissu musculaire squelettique d’un muscle de bœuf. Cette matrice a pour but de calibrer la spectro-imagerie IRTF et de quantifier à moyen terme les collagènes dans les tissus. / Myopathies are a rare disease which leads a muscular deficiency. It seems that most of the myopathies present a modification in the biodistribution and in the concentration of collagens. The current diagnosis of these diseases is based on the study of deficient proteins by molecular biology techniques whose the results are uncertain. We suggest developing the spectro-imaging IRTF to differentiate five main types of collagen in the muscular connective tissue. For that, we applied two methods: the spectral déconvolution of the amide I and the determination of the anisotropic extinction coefficient of the fibers. Then, we have set up a synthetic matrix miming the molecular composition of a squeletic muscular tissue of beef muscle. This matrix aims at calibrating the spectro-imaging IRTTF and at quantifying in the medium term the collagen in tissues.

Sommaire L’oxygène fait partie intégrante de l’environnement et ceci jusqu’au fonctionnement même des structures cellulaires qui composent le corps humain. Deux systèmes sont intimement liés à la distribution de l’oxygène, ce sont les systèmes cardiovasculaire et respiratoire. La transparence du système optique de l’œil peut être exploitée afin de mesurer de façon non invasive la concentration en oxyhémoglobine du sang qui alimente le système nerveux central. L’oxygénation capillaire de l’œil a été mesurée par spectro-réflectométrie dans deux régions de l’œil: d’une part les capillaires de la zone du nerf optique qui représentent principalement la circulation rétinienne; d’autre part, les capillaires du limbe cornéen. Cinq sujets volontaires, non fumeurs, sains, âgés de 20 à 45 ans et cinq sujets volontaires, fumeurs, sains, âgés de 20 à 40 ans ont participé à cette étude. Tous ces sujets ont été exposés à des conditions d’hyper et d’hypo oxygénation. Une séance d’expérimentations était composée d’un enregistrement continu de 360 secondes. Durant la première étape de 60 secondes, le sujet respirait de l’air ambiant. Durant une deuxième étape de 180 secondes, le sujet était exposé soit à une condition d’hyper (60% O2) soit, à une condition d’hypo oxygénation (15% O2), tandis que les 120 dernières secondes de la séance de mesure permettait d’exposer le sujet, une fois de plus à l’air ambiant. Le rythme cardiaque et les changements d’oxygénation artérielle au niveau du doigt étaient mesurés pendant ce temps vec le sphygmo-oxymètre. Les variations du taux d’oxyhémoglobine du sang au niveau capillaire de l’œil (nerf optique ou sclérotique) étaient toujours en corrélation directe avec les variations du taux d’oxyhémoglobine artériel. Toutefois, les capillaires du nerf optique offrent plus de précision pour les mesures d’oxygénation, relativement aux mesures d’oxygénation du sang contenu dans les capillaires de la sclérotique. La précision de la mesure de la concentration d’oxyhémoglobine obtenue dans cette étude par spectro-réflectométrie de l’œil, en fait un instrument utile au diagnostic d’une grande partie des pathologies pulmonaires ou oculaires. / Abstract Oxygen is an integral part of the environment. It has a major role to play in the cellular structures of the human body. The two systems, which are closely related to the distribution of oxygen within the body are the cardiovascular and the respiratory systems. The transparency of the eye can be used as a way to non-invasively measure the concentration of oxyhemoglobin in the blood which feeds the central nervous system. The capillary oxygenation of the eye was measured using multichannel spectro-reflectometry technology. Two areas of the eye were studied: the capillaries of the optical nerve which represent retinal circulation as well as the capillaries of the eye at the corneal limbus. Five healthy non-smoking volunteers aged 20-45 years and five healthy smoking volunteers aged 20-40 years took part in this study. All subjects were exposed to hypo and hyper oxygenation conditions. The experimental session was composed of a continuous recording of 360 seconds. In the first 60 seconds, volunteers breathed ambient air, followed by a second phase of 180 seconds during which the subjects were either exposed to a condition of hyper (60% O2) or hypo oxygenation (15% O2). The final phase of the experimental session was an exposure to ambient air. Cardiac rhythm and arterial oxygenation were measured at the tip of the finger with a sphygmo-oxymeter. Clearly, variations in the oxyhemoglobin blood concentration in the capillaries of the optic nerve or the sclerotic are always directly correlated with variations in the arterial oxyhemoglobin levels. However, the optic nerve capillaries offer more precision for measurements of oxygenation as compared to the sclerotic capillaries. In this study, accurate information has been provided on the oxyhemoglobin concentration using spectro-reflectometry of the eye. This technology could become a tool in the diagnosis of various pulmonary or ocular pathologies.

Sommaire L’oxygène fait partie intégrante de l’environnement et ceci jusqu’au fonctionnement même des structures cellulaires qui composent le corps humain. Deux systèmes sont intimement liés à la distribution de l’oxygène, ce sont les systèmes cardiovasculaire et respiratoire. La transparence du système optique de l’œil peut être exploitée afin de mesurer de façon non invasive la concentration en oxyhémoglobine du sang qui alimente le système nerveux central. L’oxygénation capillaire de l’œil a été mesurée par spectro-réflectométrie dans deux régions de l’œil: d’une part les capillaires de la zone du nerf optique qui représentent principalement la circulation rétinienne; d’autre part, les capillaires du limbe cornéen. Cinq sujets volontaires, non fumeurs, sains, âgés de 20 à 45 ans et cinq sujets volontaires, fumeurs, sains, âgés de 20 à 40 ans ont participé à cette étude. Tous ces sujets ont été exposés à des conditions d’hyper et d’hypo oxygénation. Une séance d’expérimentations était composée d’un enregistrement continu de 360 secondes. Durant la première étape de 60 secondes, le sujet respirait de l’air ambiant. Durant une deuxième étape de 180 secondes, le sujet était exposé soit à une condition d’hyper (60% O2) soit, à une condition d’hypo oxygénation (15% O2), tandis que les 120 dernières secondes de la séance de mesure permettait d’exposer le sujet, une fois de plus à l’air ambiant. Le rythme cardiaque et les changements d’oxygénation artérielle au niveau du doigt étaient mesurés pendant ce temps vec le sphygmo-oxymètre. Les variations du taux d’oxyhémoglobine du sang au niveau capillaire de l’œil (nerf optique ou sclérotique) étaient toujours en corrélation directe avec les variations du taux d’oxyhémoglobine artériel. Toutefois, les capillaires du nerf optique offrent plus de précision pour les mesures d’oxygénation, relativement aux mesures d’oxygénation du sang contenu dans les capillaires de la sclérotique. La précision de la mesure de la concentration d’oxyhémoglobine obtenue dans cette étude par spectro-réflectométrie de l’œil, en fait un instrument utile au diagnostic d’une grande partie des pathologies pulmonaires ou oculaires. / Abstract Oxygen is an integral part of the environment. It has a major role to play in the cellular structures of the human body. The two systems, which are closely related to the distribution of oxygen within the body are the cardiovascular and the respiratory systems. The transparency of the eye can be used as a way to non-invasively measure the concentration of oxyhemoglobin in the blood which feeds the central nervous system. The capillary oxygenation of the eye was measured using multichannel spectro-reflectometry technology. Two areas of the eye were studied: the capillaries of the optical nerve which represent retinal circulation as well as the capillaries of the eye at the corneal limbus. Five healthy non-smoking volunteers aged 20-45 years and five healthy smoking volunteers aged 20-40 years took part in this study. All subjects were exposed to hypo and hyper oxygenation conditions. The experimental session was composed of a continuous recording of 360 seconds. In the first 60 seconds, volunteers breathed ambient air, followed by a second phase of 180 seconds during which the subjects were either exposed to a condition of hyper (60% O2) or hypo oxygenation (15% O2). The final phase of the experimental session was an exposure to ambient air. Cardiac rhythm and arterial oxygenation were measured at the tip of the finger with a sphygmo-oxymeter. Clearly, variations in the oxyhemoglobin blood concentration in the capillaries of the optic nerve or the sclerotic are always directly correlated with variations in the arterial oxyhemoglobin levels. However, the optic nerve capillaries offer more precision for measurements of oxygenation as compared to the sclerotic capillaries. In this study, accurate information has been provided on the oxyhemoglobin concentration using spectro-reflectometry of the eye. This technology could become a tool in the diagnosis of various pulmonary or ocular pathologies.

Le gliome est le type le plus agressif et mortel de tumeur cérébrale. Ces tumeurs se caractérisent par la présence conjointe de phénotypes solides (de bas grade, moins invasif, hautement vascularisé) et diffus (haut grade, très envahissant et diffus) des glioblastomes multiformes. Les collagènes sont des composants majeurs de la MEC des cellules tumorales des gliomes, et sont également présents dans la membrane basale des vaisseaux sanguins, mais avec une composition différente entre vasculatures saine et tumorale. L'abondance et la typologie des collagènes dans la MEC des cellules tumorales et la vasculature représentent donc un marqueur potentiel de diagnostic pour la gradation des tumeurs gliales. Nous avons développé la spectro-imagerie infrarouge à transformée de Fourier pour déterminer les modifications morphologiques et moléculaires apparaissant dans les formes solides et diffuses de gliomes, ainsi que dans les vasculatures saine et tumorale. Nous avons d'abord mis en évidence les vasculatures saine et tumorale en utilisant des nanoparticules injectées dans le système sanguin. Ensuite, nous avons appliqué des méthodes de reconstruction spectrale pour distinguer les tissus sains vs. ceux des formes solide et diffuse de tumeurs sur la base de leurs contenus en collagène de la MEC. Enfin, nous avons déterminé les changements de types du collagène au cours de la progression tumorale, validant ainsi la notion que l’analyse de ces contenus est potentiellement un marqueur diagnostic pour la gradation des gliomes. / The glioma is the most aggressive and lethal type of brain tumor. Such tumor is characterized both by solid (low grade, less invasive, highly vascularized) and diffuse (high grade, very invasive and diffuse) phenotypes in high-grades. Collagens are major components of ECM in glioma tumor cells, and are also present in basement membrane of blood vessels in vasculature, but with different composition between healthy and tumor capillaries. The abundance and typology of collagens in tumor cell ECM and vasculature is thus a potential diagnostic marker for grading glioma tumors. We developed Fourier transform infrared (FTIR) spectro-imaging as a functional technique to determine the morphological and molecular changes occurring in solid and diffuse form of tumor tissues as well as in healthy and tumor vasculatures. We first highlighted healthy and tumor vasculatures using nanoparticles injected in blood system. Then, we applied curve-fitting methods to distinguish between healthy tissue vs. solid and diffuse tumor tissues on the basis of the collagen contents found in ECM. Finally, we determined collagen typology changes during tumor progression, thus validating that collagen contents analysis is potentially a diagnostic marker for glioma grading.

Automatic recognition of human emotion in speech aims at recognizing the underlying emotional state of a speaker from the speech signal. The area has received rapidly increasing research interest over the past few years. However, designing powerful spectral features for high-performance speech emotion recognition (SER) remains an open challenge. Most spectral features employed in current SER techniques convey short-term spectral properties only while omitting useful long-term temporal modulation information. In this thesis, modulation spectral features (MSFs) are proposed for SER, with support vector machines used for machine learning. By employing an auditory filterbank and a modulation filterbank for speech analysis, an auditory-inspired long-term spectro-temporal (ST) representation is obtained, which captures both acoustic frequency and temporal modulation frequency components. The MSFs are then extracted from the ST representation, thereby conveying information important for human speech perception but missing from conventional short-term spectral features (STSFs). Experiments show that the proposed features outperform features based on mel-frequency cepstral coefficients and perceptual linear predictive coefficients, two commonly used STSFs. The MSFs further render a substantial improvement in recognition performance when used to augment the extensively used prosodic features, and recognition accuracy above 90% is accomplished for classifying seven emotion categories. Moreover, the proposed features in combination with prosodic features attain estimation performance comparable to human evaluation for recognizing continuous emotions. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2009-09-08 13:01:54.941

Carbon dioxide electroreduction (CO2R) is a promising and sustainable route to generate valuable feedstocks through the electrochemical conversion from CO2 with electricity generated by renewable energy resources, to reduce greenhouse gas emissions, thereby protecting the global environment. One of the critical challenges for developing practical CO2R developments is understanding the structures and chemistry of CO2R electrocatalysts, and then generating fundamental insights to guide the design and optimization of high-performance electrocatalysts. During my Ph.D. studies, synchrotron-based X-ray spectro-microscopy techniques, scanning transmission X-ray microscopy (STXM) and X-ray spectro-ptychography, were used to study nickel-nitrogen-carbon (Ni-N-C) and electrodeposited Cu-based CO2R electrocatalysts. STXM and ptychography were upgraded to in situ characterizations to provide spectroscopic characterization and quantitative, chemically selective imaging of these catalytic materials under CO2R conditions. To achieve in situ STXM and spectro-ptychography, a micro-fluidic based, liquid-flow electrochemical in situ device was developed, fabricated, and implemented. The in situ device is optimized from previous versions developed by Vinod Prabu, past graduate student of Hitchcock group, and the initial concept was provided by Pablo Ingino and Dr. Martin Obst, collaborators at the University of Bayreuth. In situ STXM and spectro-ptychography provided a detailed chemical and morphological evaluation of catalyst materials at different applied potentials during electrochemical processes. The in situ STXM studies of Cu-based catalysts showed that electrodeposited Cu2O particles are converted to metallic Cu with different reaction rates at applied potentials less negative than that for initiation of CO2R. The in situ STXM results show a degree of heterogeneity in the electrochemical response of discrete nanoparticles and metallic Cu as the active catalyst for CO2 reduction which is structurally relatively stable at CO2R-relevant potentials within the spatial resolution of STXM. In situ spectra-ptychography was used to follow morphological changes of a single Cu-based catalytic particle in the electrochemical regime of CO2R. Our results show that the Cu particle lost the initial cubic structure and formed irregular dendritic-like structures during the CO2R process. To the best of my knowledge, this is the first time in situ STXM has been applied to CO2R electrocatalysts under flow liquid and electrochemical conditions and the first report of in situ spectro-ptychography studies. In summary, my research has successfully achieved the in situ STXM and spectro-ptychography experiments and contributed to an improved understanding of Cu nanoparticle CO2R electrocatalysts. / Dissertation / Doctor of Philosophy (PhD)

京都大学 / 新制・課程博士 / 博士(理学) / 甲第24421号 / 理博第4920号 / 新制||理||1703(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 一本 潔, 准教授 浅井 歩, 教授 横山 央明 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

This dissertation investigates the nonlinear wave propagation phenomena in nonlinear metamaterials with nonlinear chains and nonlinear resonators using analytical and spectro-spatial analyses. In the first part of the thesis, the nonlinear metamaterials are modeled as a chain of masses with multiple local resonators attached to each cell. The nonlinearity stems from the chain's stiffness in one case and the local resonator's stiffness in another. Analytical approximates solutions are obtained for each case using perturbation techniques. These results are validated through numerical simulations and the results show good agreement. To further demonstrate the nonlinear wave propagation characteristics, spectro-spatial analyses are conducted on the numerical integration data sets. The wave profiles, short-term Fourier transform spectrograms, and contour plots of 2D Fourier transform show the presence of solitary waves for both sources of nonlinearity. In addition, spectro-spatial features demonstrate the presence of significant frequency shifts at different wavelength limits. indent The second part of the thesis studies a nonlinear electromechanical metamaterial and examines how the electromechanical coupling in the local resonator affects the wave propagation. Numerical examples indicate that the system can be used for simultaneous energy harvesting and vibration attenuation without any degradation in the size of bandgaps. Spectro-spatial analyses conducted on the electromechanical metamaterial also reveal the presence of solitons and frequency shifts. The presence of solitary wave in the electromechanical metamaterial suggests a significant improvement in energy harvesting and sensing techniques. The obtained significant frequency shift is employed to design an electromechanical diode, allowing voltage to be sensed and harvested only in one direction. Design guidelines and the role of different key parameters are presented to help designers to select the type of nonlinearity and the system parameters to improve the performance of acoustic diodes. indent The last part of this thesis studies the passive self-tuning of a metastructure via a beam-sliding mass concept. The governing equations of motions of the holding structure, resonator, and sliding mass are presented and discretized into a system of ODEs using Galerkin's projection. Given that the spatial parameters of the system continuously change over time (i.e., mode shapes and frequencies), instantaneous exact mode shapes and frequencies are determined for all possible slider positions. The numerical integration is conducted by continuously updating the spatial state of the system. The obtained exact mode shapes demonstrate that the resonance frequency of the resonator stretches over a wide frequency band. This observation indicates that the resonator can attenuates vibrations at a wide frequency range. Experiments are also conducted to demonstrate the passive self-tunability of the metastructure and the findings colloborate the analytical results. / Doctor of Philosophy / Metamaterials are artificially engineered structures that can offer incredible dynamical properties, which cannot be found in conventional homogeneous structures. Consequently, the global metamaterials market is expected to display a 23.6$%$ compound annual growth rate through 2027. Some of these exciting properties include, but not limited to, negative stiffness, negative mass, negative Poisson's ratio. The unique dynamic properties show the importance of metamaterials in many engineering applications, such as vibration reduction, noise control, and waveguiding and localization. However, beyond the linear characteristics of metamaterials, nonlinear metamaterials can exhibit more interesting nonlinear wave propagation phenomena, such as solitons, cloaking, tunable bandgaps, and wave non-reciprocity. indent This research work investigates wave propagation characteristics in nonlinear locally resonant metamaterials using analytical, numerical, and signal processing techniques. The nonlinearity stems from the chain in one case and from the local resonator in another. Numerical examples show the presence of solitary waves in both types of nonlinearity and significant frequency shift in certain frequency/wavenumber regions. The obtained significant frequency shift can be utilized to design mechanical diodes, where its operation range can be increased by introducing nonlinearity in the resonator. indent For simultaneous energy harvesting and vibration attenuation, integrating the local resonator with piezoelectric energy harvesters is also investigated in this research work with the presence of both types of nonlinearities. For weak electromechanical coupling, the results demonstrate that the band structure of the system is not affected by the electromechanical coupling. Therefore, the system can also be used for energy harvesting without any degradation in the vibration attenuation performance. This observation is also validated experimentally for the linear limit. Spectro-spatial analyses also reveal the presence of solitary output voltage waves, which can enhance the energy harvesting and sensing. The obtained significant frequency shift can be utilized to design an electromechanical diode where the wave can propagate and be harvested only in one direction. Numerical examples show that the performance of the electromechanical diode can be significantly improved by including nonlinearities in the local resonator. indent Another goal of this research work is the introduction of passive self-tuning mechanism to design self-tuning metastructure. The design of such a metastructure is motivated by the need for broadband devices that can adapt to changing environment. The passive self-tuning concept is achieved by a sliding mass coupled with a resonator. Analytical and experimental results show the ability of this system to tune itself to the excitation frequency, and hence, can control vibrations over a significantly wider frequency band as compared to conventional resonators.

Depuis ces 3 derniers milliards d'années l'eau liquide est extrêmement peu présente sur Mars. Cependant les multiples données disponibles sur la planète montrent des preuves d'une présence importante d'eau liquide depuis l'accrétion de la planète jusqu'à environ 3,7 milliards d'années. L'hypothèse dominante aujourd'hui est que Mars possédait une atmosphère plus dense (possiblement riche en CO2) au début de son histoire. Une grande partie de cette atmosphère et de l'eau auraient été perdu dans l'espace. Une autre hypothèse pour la diminution de la quantité d'eau liquide disponible et pour la diminution de l'atmosphère est le stockage d'eau et de CO2 dans la croûte. La croûte martienne est étudiée via les données de spectro-imagerie CRISM pour caractériser l'altération hydrothermale primitive de la planète. Des détections de serpentine et de carbonates confirment que le stockage d'une partie de l'eau et de l'atmosphère martienne a eu lieu. Des contraintes supplémentaires sont apportées par de la modélisation géochimique de la serpentinisation et de la carbonatation de la croûte martienne via les programme EQ3/6. L'importance de la serpentinisation et de la carbonatation de la croûte martienne est ainsi réévaluée. Les résultats permettent d'ouvrir la réflexion sur le rôle de la serpentinisation et de la carbonatation sur l'évolution de la quantité d'eau liquide disponible et sur l'évolution de l'atmosphère. En outre, les conditions thermodynamiques permettent d'apporter des contraintes sur le potentiel exobiologique de la croûte martienne / Over the last 3 billion years liquid water has an extremely limited presence on Mars. However, the multiple data available on the planet show evidences of a significant presence of liquid water from the accretion of the planet until about 3.7 billion years. The prevailing hypothesis today is that Mars had a denser atmosphere (possibly rich in CO2) early in its history. Much of this atmosphere and water were lost in space. Another possibility for reducing the amount of liquid water available and the reduction of the atmosphere is the water storage of water and CO2 in the crust. The Martian crust is studied via CRISM spectro-imaging data to characterize the early hydrothermal alteration of the planet. Serpentine and carbonates of detections confirm that the storage of a portion of the water and the atmosphere of Mars occurred. Additional constraints are provided by the geochemical modeling of serpentinization and carbonation of the Martian crust through EQ3/6 programs. The importance of serpentinization and carbonation of the Martian crust is thus reassessed. The results allow to open the debate on the role of serpentinization and carbonation on the evolution of the liquid water available and the evolution of the atmosphere. In addition, the thermodynamic conditions help provide constraints on the exobiology potential of the Martian crust

Les micro-bolomètres non-refroidis bénéficient de développements technologiques récents qui se traduisent par des matrices de plus en plus grandes (1024*768 pixels), pour des pixels de plus en plus petits (17 µm) et de plus en plus sensibles bien que non-refroidis (NETD<60 mK @300 K). L'objectif de cette thèse est d'étudier les détecteurs micro-bolométriques non-refroidis afin de tester leurs capacités en imagerie et en spectroscopie en vue de leur utilisation dans le cadre d'une mission spatiale vers les petits corps du système solaire, dont en particulier la mission Marco Polo R. J'ai étudié le fonctionnement de ces détecteurs en prenant pour exemple le détecteur Nano640Etm de la société Ulis, représentatif de la technologie des micro-bolomètres non-refroidis disponible actuellement. J'ai mesuré la stabilité dans le temps de son signal, l'homogénéité de la matrice du détecteur, et l'influence de différents paramètres de fonctionnement (température du plan focal, temps d'intégration des pixels, gain). La réponse du détecteur est linéaire en fonction de la température de scène à la puissance 4. Les résultats de cette caractérisation m'ont permis de mesurer le NETD du détecteur dans le cadre de cette expérience. J'ai ensuite testé les capacités du détecteur Nano640Etm en imagerie radiométrique calibrée afin d'estimer les erreurs maximales de calibration pour un, deux, ou trois points de calibration placés différemment dans la gamme de température observée / The recent progress of the uncooled micro-bolometer technology has lead to larger detector matrices (1024*768 pixels), with smaller pixel sizes (17 µm) and a higher sensitivity although it is an uncooled technology (NETD<60 mK @300 K). The objective of this thesis is to study uncooled micro-bolometer detectors in order to assess their performance for imagery and spectroscopy within the framework of a space mission towards small bodies of the solar system, including the Marco Polo R mission. I have studied these detectors through the example of the Nano640Etm detector of the Ulis society, which represents well the currently available uncooled micro-bolometer technology. I have measured its signal stability through time, the detector's matrix homogeneity, and the influence of various operating parameters (focal plane temperature, integration time of the pixels, gain). The detector's response is linear as a function of the scene temperature to the power of 4. The results of this characterization allowed me to measure the detector's NETD within this experiment. Then, I tested the Nano640Etm detector's ability to perform calibrated radiometric images in order to estimate the maximum calibration error for one, two, or three calibration points chosen differently within the observed temperature range. Lastly, I assessed the detector's performances for dispersive spectroscopic measurements, using its signal to noise ratio, as a function of the observation wavelength, the scene temperature, and the spectral resolution. The results of these tests are very positive.