VictorJuiz/thesis huggingface dataset:
Behaviour and localization of chromophore absorption signals in the transmission electron microscope

Previously, an improved Prism-Mirror-Prism spectrometer was designed for a Zeiss EM902 electron microscope. Once constructed, this spectrometer was incorporated into the microscope with only minimal modifications to the mechanics and electronics of the instrument. Using this improved spectrometer design, absorption signals corresponding to light optical colour absorptions were studied at the resolution of the electron microscope. The behaviour of this signal has been characterized according to its selected energy loss behaviour and radiation sensitivity in embedded crystals of hematin and mercury orange. In cellular contexts, the photosensitizer chlorin e6 and the fluorescent dye fluorescein isothiocyanate have been localized, their signals extracted from the images using two different methods. These data were applied to study the absorption signal of the green fluorescent protein. Conditions were determined to optimize preservation of the chromophore structure through the sample preparation, and the GFP signal was observed and characterized in Chang and hepatoblastoma G2 cells.

Keywords: Biophysics
Advisor: Ottensmeyer, F Peter
Une édition critique des discours I et II du livre De l'esprit d'Helvétius

Cette thèse est la première édition critique du livre 'De l'''Esprit' d'Helvétius. L'ouvrage est publié pour la première fois à Paris en 1758. La première édition comporte deux émissions qui sont textuellement différentes parce qu'Helvétius a dû couper, remanier ou ajouter quelques passages pour satisfaire aux exigences d'un deuxième censeur. La seconde édition, publiée clandestinement peu après la première par le même libraire, comporte un texte entièrement recomposé et diffère donc matériellement de l'édition originale. Toutefois, elle est textuellement identique à la seconde émission de l'édition originale. La première émission de l'édition originale est notre texte de base car elle se conforme le plus aux intentions d'Helvétius. L'appareil critique, en bas de page, comporte les variantes de la deuxième émission de l'édition originale et de la seconde édition. Après 1758 Helvétius n'a plus modifié le texte de son ouvrage. Les notes marginales de Diderot, Rousseau et Voltaire sont également placées en bas de page. Les notes explicatives figurent dans un volume à part. Elles élucident les passages qui peuvent paraître obscurs aujourd'hui, elles identifient les passages cités par Helvétius, et elles placent l'ouvrage dans son contexte du dix-huitième siècle en montrant des parallèles entre la pensée de l'auteur et celle de ses contemporains. Une brève introduction fournit un aperçu de la pensée d'Helvétius et résume l'histoire de la publication de 'L'''Esprit'.
Fe II emission from H II regions and active galactic nuclei

This thesis focuses on the elaboration of numerical models of Fe II emission spectra and applications of these models to the interpretation of new observational data. A model of the Fe II atom, which includes the lowest 371 energy levels (up to 11.6 eV) and predicts intensities of 68635 lines, is first developed and then incorporated into the radiative-collisional code Cloudy. The atomic data and numerical methods used to determine level populations are described. The basic equations of ionization and thermal balance, level populations, and radiative transfer are solved self-consistently. Test cases show that the atom goes to local thermodynamical equilibrium in the limits of high particle and radiation densities. The quantitative models have been applied to simulate emission spectra of H II regions. The general behavior of the Fe II emission lines and their sensitivity to density and radiative pumping conditions are investigated. New spectroscopic observations of the Orion Nebula obtained at the Cerro Tololo Inter-American Observatory are presented. The spectral range is 3498-7468 Å. The spectra are high resolution and sensitivity and result in the most extensive line atlas of the Orion Nebula yet made. More than 400 emission lines have been identified, including 40 forbidden [Fe II] lines. Our theoretical model of Fe II emission is in good agreement with the observational data. The velocity field in the Orion Nebula, which shows a marked dependence on the ionization structure, has been analyzed. An overview is presented of general features of the Fe II spectra of typical quasar Broad Emission Line Regions and the dependence of these features on the basic parameters (density, flux of radiation, microturbulent velocity, the Fe abundance, and LyÃ pumping). Calculations of Fe II emission for grids spanning several orders of magnitude in density and ionizing flux are performed in the framework of "locally optimally-emitting clouds." It is shown that strong selection effects are at work. Due to the richness of the Fe II spectra and their sensitivity to the excitation parameters, the Fe II emission lines provide a powerful tool for diagnostics of physical conditions and Fe abundance in a variety of astronomical objects.
Application-specific instruction-set architectures for embedded DSP applications

Programmable digital signal processors (DSPs) are microprocessors with specialized architectural features for the efficient execution of digital signal processing algorithms at relatively low cost. These features also make DSPs difficult targets for high-level language (HLL) compilers, and require that assembly language programming be used to fully exploit their capabilities. As applications become larger and more complex, and as design cycles are required to be shorter, it is important to move towards using more HLL programming. To achieve this, more compiler-friendly DSP architectures and better DSP compiler technology are required. As DSP cores become more pervasive in embedded system-on-a-chip designs, a need is also emerging for application-specific DSP cores that can be customized to the functional, performance, and cost requirements of a target application, or group of applications. This dissertation examines the use of VLIW architectures to achieve a suitable compiler target while being able to express the forms of parallelism found in most DSP applications. Performance improvements by factors of 1.8-2.8 are shown to be achievable simply by using a VLIW architecture compared to more traditional architectures. A method for reducing the instruction bandwidth and storage requirements of VLIW architectures is also proposed, and its impact on performance and cost is examined. To handle some of the DSP-specific architectural features, an optimizing C compiler is developed. In particular, two algorithms that enable the compiler to allocate data automatically across dual data-memory banks are developed, and their impact on cost and performance are examined. Finally, a set of tools that enable a designer to customize the architecture and its instruction set to the requirements of a target application is also presented. This includes an area-estimation model and an instruction-set simulator for measuring cost and execution performance.
Semi-blind strategies for interference suppression in DS-CDMA systems

QAM modulation of OFDM signals (OFDM-QAM) is a popular modulation scheme for linear communication systems because it achieves good spectral efficiency while simplifying the equalization process. This comes at the cost of requiring accurate synchronization methods in the receiver, highly stable oscillators (low phase-noise); and power inefficient transmission. This work addresses issues in these three areas. First, a new frame synchronization method is developed based on Bayesian changepoint principles. It has higher accuracy then current popular methods, can be implemented recursively, and has been tested with success on experimental data collected in a WLAN testbed. Second, phase-noise resistant communication is investigated by performing an accurate statistical analysis of self-heterodyne communication systems. The analysis can be used to accurately predict the bit error probability of such systems. Third, power efficient transmission using phase-modulation (OFDM-PM) is analyzed. The bandwidth, equivalent baseband model, and symbol error probability are investigated. We can now predict the performance of OFDM-PM systems; for a given spectral efficiency, when operating well into the threshold region of angle-demodulators., The semi-blind algorithms presented in this work attempt to improve interference suppression for a given number of training and information symbols by combining training-based and blind estimation techniques. We first derive the minimum number of training symbols the training-based least squares (LS) estimator requires for complete suppression of interference (in the noiseless case). This provides a benchmark which the semi-blind algorithms are compared against. Next, a framework for semi-blind iterative interference suppression is developed which is then used to enhance the LS estimator by adding the constant modulus and cyclostationary properties used in blind algorithms. Finally, a decision-aided (multistage) semi-blind algorithm that jointly processes the signals from all intra-cell users is presented. Simulation results indicate a significant improvement over training-based and blind estimation techniques. Application of this work is in the reverse-link of third generation short-burst asynchronous DS-CDMA systems subject to both ISI and MAI.
Analysis of human CYP2E1 mRNA in a HepG2 cell line by reverse transcription-polymerase chain reaction (RT-PCR)

The research interest of this thesis work focuses on the regulation of human CYP2E1 mRNA in the absence and presence of potential endogenous inducers, cAMP and insulin. The study of human CYP2E1 mRNA stability and the effects of endogenous inducers on the levels of mRNA has been hampered by the inability to establish a cell culture model system that yields consistently detectable levels of CYP2E1 mRNA. In this study we have reassessed HepG2 cells as a model for human CYP2E1 mRNA expression. In these cells, we (and others) have demonstrated the lack of CYP2E1 mRNA detection by Northern analysis. We have developed a reverse transcription polymerase chain reaction (RT-PCR) procedure that facilitates effective detection of CYP2E1 mRNA. This study details the optimization of RT-PCR parameters for CYP2E1 and GAPDH mRNAs. As validation of the use of RT-PCR as a method for the analysis of mRNA stability, we assessed the expression of GAPDH mRNA from HepG2 cells treated with transcriptional inhibitor, 5,6-dichloro-1 $\beta$-D-ribofuranosylbenzimidazole (DRB), by Northern and RT-PCR methods. The amount of GAPDH mRNA present at increasing times after DRB exposure is reflective of mRNA stability. (Abstract shortened by UMI.)
Aryl hydrocarbon receptor-mediated regulation of gene expression in embryonic stem cells

The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that plays a key role in mediating the toxicity of various environmental pollutants such as 2,3,7,8-tetrachlorodibenzo-'p'-dioxin (TCDD). In its native form the AHR resides in the cytoplasm of the cell and upon ligand binding to the receptor, a series of events is triggered that ultimately results in the altered expression of several genes. TCDD is a potent teratogen and developmental toxicant in several species. The mechanisms by which these adverse events are induced by TCDD remain unclear, but it is thought that the alteration in the expression of these genes particularly during development contributes to the toxicities observed. In the current study, I employed embryonic stem cells (ES R1), totipotent cells derived from mouse blastocysts, in conjunction with gene trap methodology to explore the AHR-mediated regulation of gene expression in the ES R1 cells to further understand the underlying mechanism of AHR-mediated teratogenesis. (Abstract shortened by UMI.)
The role of Rom-1 in maintaining photoreceptor structure and viability, and a mathematical model exploring the kinetics of neuronal degeneration

Rom-1 and peripherin/rds are homologous membrane proteins localized to the disk rims of photoreceptor outer segments (OSs), where they are postulated to be critical for disk morphogenesis, OS renewal, and the maintenance of OS structure. 'Rds'-/- mice (homozygous for a null mutation in the gene encoding peripherin/rds) do not form OSs, indicating that peripherin/rds is essential for OS formation. Futhermore, mutations in RDS cause retinal degeneration, indicating that Peripherin/Rds is necessary for photoreceptor viability. To determine if rom-1 is also critical for maintaining photoreceptor structure and viability, we generated ' Rom1'-/- mice using gene targeting. 'Rom1'-/- mice exhibit a gradual apoptotic death of rod, but not cone, photoreceptors, so that by 18 months of age, 42% of all rods had died. Electroretinogram analysis indicated that although rom-1 is not involved in phototransduction, nine month 'Rom1 '-/- mice displayed a significant decline in photoreceptor function. These results indicate that, like peripherin/rds, rom-1 is required for the maintenance of photoreceptor viability. ' Rom1'-/- mutants form rod outer segments (ROSs), indicating that expression of peripherin/rds alone is sufficient for disk and OS morphogenesis. Mutant ROSs were disorganized: they were not straight and parallel as in control mice. We suggest that the disorganization results from the production of markedly enlarged ROS disks. To test the hypothesis that the accumulation of cellular damage causes neuronal death, we analyzed the kinetics of cell death in 12 animal models of photoreceptor degeneration, and in four examples of neurodegeneration occurring in other parts of the nervous system. We found that the kinetics of cell loss in all examples were best fit by mathematical models in which the risk of cell death decreased or remained constant. These results are inconsistent with the increasing risk predicted by cumulative damage, and instead indicate that the time of death of an individual neuron is random. Finally, we demonstrate that the digenic hypothesis of retinitis pigmentosa (RP) is correct: mice inheriting one Rom] null allele in combination with one L185P 'Rds' substitution exhibit an accelerated rate of photoreceptor death in comparison to mice inheriting only one of these alleles.
Data integration using virtual repositories

Online information is available from a variety of sources. These include databases, transaction systems, the World Wide Web, respositories, and file systems. Increasingly, specialized applications offer their internal data for export as well. A problem often faced by enterprises is to create integrated, browsable representations of data from these sources. This is normally done by duplicating source information in a database or persistent repository. This thesis introduces active virtual repositories (AVR's) as a means of data integration for read-only browsing. Analogous to virtual databases, AVR's do not duplicate the source information persistently. Thus, they do not have to deal with the synchronization issues between the sources and copies of the data. Instead, they simulate repositories by allowing retrieval of entities and navigation across their properties. AVR's encode metadata about source applications in object-oriented schemata. These schemata are represented in the XML Metadata Interchange (XMI) format. The schemata coordinate navigation between the different sources and present them as a single information service. A separate metamodel is created for each source to be integrated. This embodies: (1) the source's subject domain and data model, (2) the methods and formats the source offers for data access and (3) the dependencies between sources that derive data from each other. (Abstract shortened by UMI.)
Adding Metacognitive Functioning to a Phenotypic Profile of College-age Individuals with a Reading Disability

This study investigates the relationships between phonological ability, aptitude, and metacognitive behaviour in college age students with a reading disability. It expands on a "phenotypic profile" of reading disability developed by Stanovich and Siegel (1994), and adopts the notion suggested by Sternberg (1988) that adaptive behaviour is the hallmark of intelligence. Results reported here suggest that the profile of reading disability changes between childhood and adulthood, where those with a reading disability of relatively high aptitude are able to adapt their strengths to compensate for a phonological weakness by using visual or orthographic strategies. The results strongly suggest that college age students with a reading disability possess orthographic ability superior to students without a reading disability, and perform as well or better than their non-disabled peers on reading tasks that involve little or no phonological skill. A number of results converge to suggest that a visual strength and a verbal weakness may characterize a reading disability, while a verbal strength and no visual strengths characterize good readers.
The friction between rationales of national ownership, macroeconomic prudence/supervision and financial restructuring in national banking sectors, how global/regional trade agreements have intensified a competitive rivalry among financial firms operating in the global economy based on the differences between domestic regulatory frameworks

I seek to examine the dynamic interconnection between a range of disparate regulatory interventions that influence and/or constrain the strategic positioning of financial firms, which may also possibly give rise to a competitive strategy used by national banks that may be accessory to the creation of anti-competitive practices, albeit justified in the name of macroeconomic prudence and supervision. I illustrate these complexities in the case of Canada. In turn, I concluded that the gains from the liberalisation of national banking sectors are only realised if policy interventions are left untouched. In this sense, the process of liberalisation involves reaching a consensus on where to draw the line between regulations that are barriers to trade and regulations that are necessary for prudential purposes.
Regulation of ClC-2 chloride channel by protein kinase C phosphorylation

ClC-2 is an inward-rectifying chloride channel that is expressed ubiquitously in the body. It is found present in the apical membrane of respiratory epithelial cells, where the chloride channel defective in cystic fibrosis (CFTR) is also present, providing a possible target for cystic fibrosis therapy. ClC-2 channel has been shown to be down-regulated by phorbol esters, although the mechanisms are not known. In this study, we show that the phorbol ester phorbol 12,13 di-butyrate (PDBu) regulates ClC-2 via the protein kinase C (PKC) phosphorylation pathway. In addition, we report that activation of PKC phosphorylation by PDBu mediates a decrease in cell-surface expression of ClC-2. Therefore, membrane trafficking plays an important role in the regulation of ClC-2 activity by PKC phosphorylation.
Bending stiffness prediction for Oriented Strandboard by Classical Lamination Theory

In this study, the feasibility of applying Classical Lamination Theory to predict the bending modulus of Oriented Strandboard was evaluated. First, the elastic mechanical properties (modulii and Poisson's ratio) and the longitudinal modulus (EL) versus density relationship of Oriented Strandboard's main constituent, Aspen flakes were measured. Image analysis was then applied to determine the grain orientations of the flakes on the surface of Oriented Strandboard and the bending modulus was measured. After these measurements, a pair of one-millimeter thick layers was planed from the top and the bottom surfaces of Oriented Strandboard. The image analysis and bending modulus measurements were repeated until the specimens were two-millimeter thick. The density of each layer was also measured during the experiment. With the knowledge of the properties of Aspen, the density of the layers, and their orientation distributions. Classical Lamination Theory was applied to determine the tensile modulus of each layer. After determining the tensile modulus of each layer, the bending modulus of the Oriented Strandboard specimens was predicted by the parallel axis theorem. The predicted bending modulus was compared to the measured bending modulus. The deviation for the five specimens cut parallel to the principle alignment direction of the surface flakes was nine percent, and the deviation for the five specimens cut perpendicular to the principle alignment direction of the surface flakes was eight percent. The excellent agreement between the predicted and the measured bending modulus proved that both image analysis and Classical Lamination Theory are useful tools to evaluate the bending modulus of Oriented Strandboard.
Assessing the needs of visually handicapped students and workers

This study examined the practical, personal, social, economic and technical experiences of visually handicapped students and workers in Ontario schools and workplaces. The examination was based on the data generated from a series of semi-structured interviews with eleven visually impaired participants who have widely different educational and work experiences. The data from the interviews served as a basis for evaluating the appropriateness of current needs assessment tools and practices in Ontario and other jurisdictions. In order to reflect the above mentioned experiences accurately, a qualitative research paradigm, using a series of case studies, was chosen as the most appropriate strategy for investigation. A somewhat unusual feature of this approach was the opportunity it provided to explore in depth as well as in breadth the lives of the participants. In this case, the persons with visual impairments who provided the information to the study were treated as research partners. They had direct, timely, and meaningful input into the many and varied activities of this study in order to establish mutual trust, thereby enhancing the trustworthiness of the data. The results of this study indicated that there are clearly significant barriers for people with visual impairment in their educational, social and work lives. The kinds of inadequacies cited by the participants included problems with the availability of information in an accessible format and the psychological, technical, and academic preparedness of educators, employers and support staff to create a level playing field for students and workers with visual disabilities and their sighted counterparts. A somewhat surprising finding was that participants felt that both mainstream institutions and those institutions designed to provide education exclusively to persons with visual impairments had similar instructional and employment barriers. In the workplace, they were particularly concerned about the difficulties they had in work discussions because they were not given in accessible format the background material that sighted workers had. In classrooms, they were concerned about teachers who did not provide educational materials in accessible format in a timely manner. In addition, they had limited opportunities for interacting with the community at large both on the intellectual and social levels.