Recherche uO, le dépôt numérique de l'Université d'Ottawa, réunit le matériel de recherche et d'enseignement créé par notre communauté universitaire et nos partenaires. Le savoir de l'Université est ainsi disponible à long terme et en accès libre, ce qui lui procure de la visibilité et facilite sa diffusion.
Communautés dans DSpace
Sélectionner une communauté pour parcourir les collections sous-jacentes.
Nouveaux dépôts
Type d'Item : Item , Concurrent Evaluation of Marker-Based and Markerless Motion Capture for Assessing Sex-Based Differences in Lower Limb Kinematics and Anthropometrics(Université d'Ottawa / University of Ottawa, 2026-10-22) Speers, Maxine; Graham, Ryan B.; Clouthier, Allison L.Markerless (ML) motion capture has become increasingly popular in biomechanics because it addresses many practical limitations of marker-based (MB) systems by being less time consuming and more user friendly, and it enables movement data to be collected outside traditional laboratory environments. Systems such as Theia3D have been used to evaluate military and sports performance and in clinical assessments. However, while numerous validation studies have demonstrated promising accuracy, important limitations remain. These include limited transparency regarding kinematic model constraints and training datasets, as well as systematic differences between ML and traditional MB motion capture in joint centre definitions and allowable range of motion in each joint and anatomical plane. These differences make it challenging to distinguish true biomechanical differences from measurement-related differences. This consideration is particularly relevant when examining sex-based biomechanics, where known differences in movement patterns, injury mechanisms and musculoskeletal conditions exist. Understanding how ML and MB systems compare in capturing these differences is important for both research and clinical interpretation of results. The purpose of this study was to compare MB and ML motion capture in their ability to detect established sex-based anthropometric and kinematic differences, and to determine whether the differences between motion capture systems are equivalent across sexes. Twenty-eight healthy adults (14 males, 14 females; 27 ± 4 years) completed self-selected-speed walking and drop vertical jumps (DVJ) while data were recorded simultaneously with both systems. To improve comparability, MB segment coordinate systems were aligned to the ML reference frame using a mean transformation matrix prior to kinematic analysis. Both systems detected expected sex differences in hip width and shank length (p < 0.001). However, ML estimated notably shorter femur lengths compared to MB and did not identify a significant sex-based difference in thigh lengths, a well-established relationship in the literature. Comparison of joint centres revealed systematic offsets between the motion capture systems, with total mean offset of 3.37 ± 1.4 cm at the pelvis and 4.02 ± 1.3 cm at the hip. In general, ML pelvis and hip joint centres were positioned more distally compared to MB, across both static and dynamic trials. For kinematics, both systems identified robust main effects of sex in frontal plane pelvis and hip motion. Sagittal plane waveforms showed very strong agreement between systems (r = 0.98). However, agreement was substantially weaker in the transverse plane for hip, knee, and ankle rotation (r < 0.5). Applying local coordinate system (LCS) alignment reduced overall root mean squared difference (RMSD) from 5.61 ± 4.11° to 3.12 ± 1.88° and significantly reduced systematic differences. For example, ankle rotation RMSD during walking decreased from 12.71° to 4.94° in males, and from 16.14° to 6.11° in females. Despite improvements, females generally exhibited larger RMSD between ML and MB at several joints, including pelvis rotation, ankle inversion and ankle rotation, suggesting a sex-specific effect in the comparison of MB and ML systems. Although LCS alignment substantially improved agreement, residual discrepancies remained. Overall, both MB and ML systems identified key sex-based gait and landing characteristics. Both systems consistently identified greater pelvic list, hip adduction, and ankle flexion in females during walking, as well as greater anterior pelvic tilt, knee abduction, and ankle flexion in females during the drop vertical jump. However, agreement was generally higher in the sagittal plane, whereas lower agreement in non-sagittal plane kinematics - especially among females - highlights the need for careful consideration when choosing between ML and MB motion capture for research or clinical applications that rely on detecting subtle non-sagittal plane mechanics.Type d'Item : Item , Satellite Remote Sensing of Inland Water Quality: Sensor Evaluation, Atmospheric Correction, and Empirical Modeling(Université d'Ottawa / University of Ottawa, 2026-10-22) Ansari, Mohsen; Knudby, Anders J.Inland waters represent a critical yet understudied environment in satellite Remote Sensing (RS), occupying a unique position between terrestrial and open oceans systems that makes them particularly challenging to monitor from space. Despite their ecological and socioeconomic importance, only 60% of known inland waters meet good ambient water quality standards, underscoring the need for cost-effective, large-scale monitoring solutions. Satellite RS offers such a solution, but its effectiveness depends on three interconnected components: suitable sensors, accurate atmospheric correction, and robust retrieval models. This thesis advances each of these components through four studies. Chapter 1 provides a comprehensive review of satellite RS for inland Water Quality Parameter (WQP) retrieval, synthesizing developments in sensor technologies, atmospheric correction algorithms, and Machine Learning (ML) models. The review identifies three key research gaps that motivate the subsequent chapters: the potential of hyperspectral data for inland WQP retrieval, the impact of Adjacency Effect (AE) correction on WQP retrieval, and the influence of spatial autocorrelation on ML model evaluation. Chapter 2 addresses hyperspectral sensor capability by evaluating Wyvern Dragonette-001 against Sentinel-2 MSI for retrieving chlorophyll-a, colored dissolved organic matter, dissolved organic carbon, suspended solids, and turbidity in the St. Lawrence River, Canada. Wyvern demonstrated competitive performance for turbidity retrieval but underperformed relative to Sentinel-2 for chlorophyll-a, colored dissolved organic matter, presumably due to the absence of blue spectral bands. These results highlight that hyperspectral capability alone does not guarantee superior WQP retrieval performance. Chapter 3 addresses atmospheric correction by investigating the impact of AE correction on turbidity retrieval from Landsat 8/9 and Sentinel-2 imagery in the St. Lawrence River. Applying T-Mart AE correction prior to atmospheric correction with ACOLITE's Dark Spectrum Fitting technique improved retrieval accuracy for both sensors, with Root Mean Square Error reductions of 48.8% and 28.4% for Landsat 8/9 and Sentinel-2 respectively, compared to atmospheric correction alone. The most pronounced improvements were observed within 300 meters of the shoreline, where AE from surrounding land are strongest, demonstrating that AE correction is a meaningful and necessary preprocessing step in riverine environments. Chapter 4 addresses WQP retrieval modeling through a comprehensive comparison of 24 statistical and ML models for salinity mapping in the Karun River, Iran, using Landsat 8 OLI imagery. Decision tree-based ensemble models, particularly Gradient Boosted Decision Trees, achieved the highest accuracy while also exhibiting non-significant residual spatial autocorrelation. A key finding is that strong statistical performance metrics do not necessarily indicate spatially uncorrelated residuals, and vice versa, demonstrating that residual spatial autocorrelation analysis is an essential complement to conventional performance evaluation when satellite imagery is used to map WQP. Together, these contributions demonstrate that advances in inland WQP retrieval depend on progress across three distinct but interconnected components: sensor design, atmospheric correction algorithms, and retrieval methodology. Moreover, the findings provide actionable guidance for researchers and practitioners developing satellite-based monitoring systems for inland waters.Type d'Item : Item , Cryogen-Free Zeeman-Perturbed NQR and Green Mechanochemistry for Halogen and Chalcogen Bonding in Molecular Solids(Université d'Ottawa / University of Ottawa, 2026-10-22) Nari, Alireza; Bryce, David L.Understanding the relationships between crystal structure, local electronic environment, and intermolecular interactions is fundamental to the rational design of molecular solids for applications in pharmaceuticals, supramolecular chemistry, and functional materials. This dissertation presents complementary advances in the sustainable characterization and synthesis of molecular solids through the development of cryogen-free Zeeman-perturbed nuclear quadrupole resonance (Zp-NQR) spectroscopy, integrated multimodal structural analysis, and mechanochemical synthesis. The primary contribution of this work is the development of a practical and versatile cryogen-free Zp-NQR methodology for investigating quadrupolar nuclei in molecular solids. By introducing a weak magnetic field, generated by an adjustable electromagnet, to perturb the pure quadrupolar energy levels and analyzing the resulting spectral line shapes using exact Hamiltonian simulations, a robust experimental workflow was established for accurately determining the complete electric field gradient (EFG) tensor directly from powder samples. This approach eliminates the need for superconducting magnets and liquid-helium cryogens, significantly lowering the experimental barriers associated with quadrupolar spectroscopy while providing a more sustainable and accessible alternative to conventional high-field magnetic resonance techniques. Building upon this methodological foundation, the analytical capabilities of Zp-NQR were further expanded. Zeeman perturbation was shown to enable direct experimental identification of quadrupolar isotopes by measuring their characteristic Zeeman response to an applied magnetic field. Analysis of the resulting spectral splitting allows the corresponding Larmor frequency and gyromagnetic ratio (γ), which is unique to each isotope, to be determined experimentally, thereby enabling unambiguous isotopic assignment and the identification of overlapping resonance lines in complex, and multicomponent, molecular solids without isotopic enrichment or prior structural information. The methodology was subsequently extended to demonstrate that experimentally determined quadrupolar interaction parameters serve as sensitive reporters of halogen bond strength. By combining Zp-NQR with relativistic density functional theory (DFT) calculations, strong correlations were established between quadrupolar coupling constants, electric field gradient tensors, electronic structure descriptors, and halogen-bond interaction energies, providing a direct experimental approach for quantifying halogen-bond strength in molecular solids. The versatility of the methodology was further demonstrated through the site-resolved characterization of chlorine-bearing pharmaceutical materials. An integrated approach combining ³⁵Cl Zp-NQR, zero-field NQR, high-field solid-state NMR (SSNMR), three-dimensional electron diffraction 3D ED, and first-principles calculations enabled the structural characterization of pharmaceutical cocrystals, hydration-dependent materials, degradation products, and conformationally disordered systems directly from powder samples. The combined methodology resolved chemically inequivalent chlorine environments and provided detailed insight into crystal packing, hydration, disorder, and local electronic structure, establishing a multimodal framework for pharmaceutical solid-state characterization. Complementary studies expanded the scope of this dissertation beyond quadrupolar resonance spectroscopy. Combined ⁷⁷Se magic-angle spinning (MAS) SSNMR spectroscopy and first-principles quantum chemical calculations were employed to investigate selenium-centred non-covalent interactions, providing detailed insight into the amphiphilic behaviour of selenium and its participation in halogen and chalcogen bonding. In parallel, resonant acoustic mixing (RAM) was demonstrated as a gentle, scalable, and solvent-efficient mechanochemical route for the synthesis of halogen-bonded cocrystals. RAM successfully produced phase-pure materials, enabled the discovery of previously unknown crystal forms, and expanded accessible polymorphic and stoichiometric landscapes beyond those attainable by conventional ball milling. Overall, this dissertation demonstrates how advances in cryogen-free magnetic resonance spectroscopy, complementary crystallographic and computational techniques, and sustainable mechanochemical synthesis can be integrated into a unified framework for molecular solid research. Beyond expanding the analytical capabilities and accessibility of quadrupolar resonance spectroscopy, this work establishes experimentally grounded approaches for probing local electronic structure, intermolecular interactions, and structural complexity while promoting more sustainable practices in the characterization and synthesis of molecular materials.Type d'Item : Item , Toward Precision Bioengineering of Human-Induced Pluripotent Stem Cells: A Modular Platform for Transcriptional Reprogramming and Targeted Genomic Integration(Université d'Ottawa / University of Ottawa, 2026-10-21) Hwang, Roy; Kaern, MadsCellular reprogramming marks a new era of regenerative medicine and immunotherapy, enabling stem cell researchers to develop new models, therapeutics, and technologies with human-induced pluripotent stem cells (hiPSCs) at their core. However, hiPSC translational research is often limited by slow differentiation kinetics, heterogeneity within differentiated populations, transgene silencing during lineage commitment and unpredictable genomic profiles. Current methods for bioengineering hiPSCs lack the precision and modularity required to develop regenerative medicine-based therapeutics and complex modelling applications. This thesis describes the development of a modular bioengineering platform that demonstrates accelerated transcriptional reprogramming and precise, stable targeted genomic integration in human hiPSCs. By characterizing the feasibility of these two approaches, a framework and toolkit for downstream precise stem cell-based bioengineering were established. Here, we designed a multiplexed CRISPR activation system for the directed differentiation of hiPSCs by targeting coordinated transcriptional programs and genes. This modular approach generated human iPSC-derived brain endothelial-like cells (iBECs), shortening conventional differentiation timelines by 61% while maintaining and expanding key phenotypic markers. Moreover, to achieve stable and safe transgene expression, we describe a site-specific engineering platform for hiPSCs across four genomic safe harbours (GSH): AAVS1, CCR5, hRosa26 and the novel hRogi1 locus. We evaluated the performance of modular genetic cassettes, benchmarking the stability of traditional (CAG, EFS) and unique (CBX3.1) promoters to mitigate gene silencing during lineage differentiation into germ layers. Finally, by using recombinase-mediated cassette exchange (RMCE), we demonstrate a proof-of-principle “plug-and-play” pipeline that enables the swapping of synthetic cargoes, providing a modular platform for downstream translational applications. Collectively, this research delivers a comprehensively optimized bioengineering toolkit and blueprint for hiPSCs that improves differentiation fidelity and the reliability of genomic modifications. The modularity of this toolkit positions this research uniquely and lays the basis for the future advancement of next-generation cell therapies and complex models.Type d'Item : Item , Marūṯā de Maypherqaṭ : Un évêque transfrontalier entre Byzance et la Perse dans l'Antiquité tardive(Université d'Ottawa / University of Ottawa, 2026-10-21) Amanatidis-Saadé, George; Greatrex, Geoffrey; Jullien, ChristelleAu tournant du Ve siècle ap. J.-C., un renouveau des relations entre les empires romain d'Orient et perse sassanide est inauguré en partie grâce à l'action d'un homme : Marūṯā de Maypherqaṭ, évêque d'une cité frontalière du nord de la Mésopotamie. Aucune étude d'ensemble ne lui avait encore été consacrée. Pourtant, ce personnage polymorphe fut au coeur des enjeux géostratégiques et ecclésiaux de son temps : médiateur recherché dans un contexte de profondes tensions, acteur de la refondation de l'Église de l'Orient et de sa reconnaissance officielle, conseiller du šāhānšāh Yazdgird Ier, initiateur de réseaux d'alliances et d'un culte transfrontalier, il contribua au rayonnement d'une culture hégémonique. Cette thèse propose l'analyse critique d'une trajectoire transculturelle hors norme à partir d'une relecture du corpus documentaire, des traditions associées et des processus de construction d'une mémoire posthume. Elle ouvre à une nouvelle compréhension de la société frontalière du Ve siècle et de ses dynamiques historiques. At the turn of the fifth century A.D., a renewal of relations between the Eastern Roman Empire and the Sasanian Persian Empire was ushered in largely thanks to the efforts of one man: Marūṯā of Maypherqaṭ, bishop of a frontier city in northern Mesopotamia. Although no comprehensive study has yet been devoted to him, Marūṯā was nonetheless a multifaceted figure at the heart of the geostrategic and ecclesiastical issues of his time: a mediator in a context of deep tensions, a key-figure in the re-establishment of the Church of the East and its official recognition, an advisor to the šāhānšāh Yazdgird I, and the initiator of network of alliances and a cross-border martyr cult, thus contributing significantly to the culture of his time. This thesis offers a critical analysis of this extraordinary transcultural phenomenon based on a re-examination of the documentary corpus and associated traditions, and the examination of the processes of memory construction. Through this methodology, a new understanding of 5th-century frontier society and its historical dynamics is achieved.