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Type d'Item : Item , Cellular Mechanisms Determine Soma-dendrite Correlation(Université d'Ottawa | University of Ottawa, 2026-10-30) Huang, Yusheng; Naud, RichardNeurons receive synaptic inputs across spatially separated compartments, and the relationship between dendritic processing and somatic output can shape how information is represented in spikes and bursts. However, it remains unclear how compartmentalization within a single neuron interacts with multiplexing, in which multiple input streams are represented simultaneously in a single spike train. This thesis uses a two-compartment neuron model to study how dendritic and somatic dynamics jointly support multiplexed coding. The model separates dendritic integration from somatic spike generation while allowing interaction in both directions through forward dendrite-to-soma drive and spike-triggered soma-to-dendrite feedback. Compartmentalization is quantified operationally using the Pearson correlation between dendritic and somatic membrane voltages, and multiplexing is quantified by the extent to which two output features, event rate and burst fraction, track two compartment-specific input streams. The results indicate that multiplexing is strongest at an intermediate level of compartmentalization, as measured by soma-dendrite voltage correlation: when this correlation is high, event rate and burst fraction become less specific to their corresponding input streams, whereas when this correlation is low, dendritic and somatic activity are less effectively linked. Finally, the thesis introduces a compact metric to quantify how noise, forward dendrite-to-soma drive, and spike-triggered soma-to-dendrite feedback shape the relationship between compartmentalization and multiplexing. This work offers a perspective on the design principles of neural computation and may inform future modeling of signal processing in complex neural structures.Type d'Item : Item , Investigating Temporal Resolution in Children with Listening Difficulties Using a Novel Multi-Deviant Paradigm(Université d'Ottawa | University of Ottawa, 2026-10-30) Omidvar, Shaghayegh; Koravand, AminehAuditory temporal resolution is the ability to detect rapid changes in sound. It is often measured using gap-detection tasks, in which a listener detects a brief silent interval within a continuous or long-duration sound. Gap detection is important for speech perception because many speech cues depend on fine temporal information. However, behavioural gap-detection tasks require attention, motivation, and active responses. These factors are especially important when testing children, including those with auditory processing disorder (APD), because poor behavioural performance may not always reflect a pure auditory temporal-processing deficit. The present thesis examined automatic auditory gap detection using event-related potentials (ERPs). The main focus was the deviant-related negativity (DRN), an electrophysiological response elicited by a gap deviant. The thesis investigated whether the temporal position of a gap affects the DRN and whether a time-efficient multi-deviant paradigm can be used to study multiple gap onset times within a single recording sequence. Behavioural and electrophysiological gap detection were examined in adults, typically developing (TD) children, and children with APD. Participants completed passive electroencephalography (EEG) recordings while watching a silent subtitled video and ignoring the auditory stimuli. The standard stimulus was a 500-ms broadband-noise burst. Deviants were created by inserting a silent gap of either 10 or 30 ms at different onset times, ranging from 15 to 400 ms after stimulus onset. In a separate behavioural task, participants actively detected the occurrence of the gap. There was no significant difference in DRN amplitude between the multi- and single deviant paradigms. Across groups, DRN amplitude was larger for 30-ms than for 10-ms gaps and decreased when the gap occurred later in the stimulus. In adults, the DRN was reduced for gaps occurring at 300 and 400 ms. In TD children, this temporal limitation was stronger, with reliable DRNs mainly observed for early-occurring gaps. Behavioural performance was generally high, but children performed more poorly than adults. Children with APD also showed poorer behavioural gap detection than TD children. However, their overall DRN amplitude was not consistently reduced, although less stable responses were observed in some conditions. Overall, this thesis showed that automatic neural detection of gaps is affected by both gap duration and gap onset time. The findings support the idea that auditory deviance detection is limited by a short temporal integration window. This limitation appears stronger in children than in adults. In children with APD, poorer behavioural performance may partly reflect task demands or attention rather than a consistent deficit in automatic auditory change detection. The multi-deviant gap paradigm may therefore be considered in future work as a time-efficient approach for studying auditory temporal processing in adults, children, and clinical populations.Type d'Item : Item , Left Out of Sight: Exploring Stigma in Healthcare Accommodations for Canadians with Low Vision(Université d'Ottawa | University of Ottawa, 2026-10-30) Macdonald, Isabella; Fraser, SarahBackground/Rationale: Older adults with low vision or blindness face healthcare barriers that extend beyond service access, including stigma, ageism, and inconsistent accommodations. Little is known about how these barriers operate within Canadian healthcare settings. Research Questions: What do older adults report when requesting accommodations, and how do provider interactions reflect stigma and ageism? Objective: To explore how older adults with low vision and blindness experience requesting accommodations and interacting with providers in the Canadian healthcare system, primarily in Ontario, where 14 of the 15 participants resided. Methods: Semi-structured interviews were conducted with 15 adults with low vision or blindness who had accessed Canadian healthcare within the previous 10 years. Participants were recruited through community, retiree, and disability organizations. Results: Seven themes were identified. Continuity of care provided the context against which other experiences were measured. Three challenges were described: inconsistent accessibility, clinician and staff gaps, and stigma. Participants responded through family advocacy and self-advocacy, and identified recommendations for recognition, systemic reform, and training. Accommodations were available when requested but were rarely anticipated, which transferred the work of obtaining accessible care to participants and their families. Conclusion: Healthcare in Ontario, where most participants resided, accommodated participants when asked but did not anticipate their needs. Findings inform more equitable, age-inclusive, and disability-conscious healthcare practice.Type d'Item : Item , Comparable Differentials, Distinct Architectures. Parliamentary Mediation, Emiri Concentration, and The Citizenship Differential in Kuwait and Qatar.(Université d'Ottawa | University of Ottawa, 2026-10-30) El Idrissi, Meryem; Vairel, FrédéricKuwait and Qatar allocate to their citizens similar income entitlement over non-citizens; however, they constitute it in different ways. This thesis examines that entitlement, which it conceptualizes it as the citizenship differential, across two closely paired, resource-dependent Gulf monarchies distinguished by one institutional variable, given that Kuwait maintained an active elected Assembly during the period studied, while Qatar did not. Disaggregating official household survey data through five distinct channels (employment, asset income, government transfers, subsidies and legal restrictions on non-citizens), using four Kuwaiti survey waves (1999/2000 – 2019/2021) and one Qatari survey for 2006/07, the analysis inclusive of imputed rent yields disparities of 2.72 times in Qatar and 2.91 times in Kuwait. Qatar’s differential is driven from state transfers and subsidies and Kuwait’s stems from employment. Therefore, their near-identical totals are the product of arithmetic cancellation rather than a shared institutional design. Meanwhile, non-citizens across both jurisdictions converge on the same floor due to the kafāla system. Due to Qatar’s limited data disclosure constituted of only one survey, the comparison rests on the two closest survey waves. This study advances a channel-by-channel disaggregation of the income gap, while extending existing institutional frameworks of welfare stratification from class cleavages to the divide between citizens and expatriates.Type d'Item : Item , Re-evaluating the South Cyclades Shear Zone, Ios, Greece(Université d'Ottawa / University of Ottawa, 2026-10-29) Salo, Camryn; Schneider, DavidMetamorphic core complexes (MCC) are large-scale extensional structures that exhume mid- to lower- crustal rocks beneath low-angle detachment systems and provide important insight into the processes of crustal deformation, metamorphism, and tectonic exhumation. The island of Ios, Greece, has long been regarded as a classic example of an MCC, where exhumation of the Cycladic Basement (CB) has traditionally been attributed to Miocene displacement along the so-called South Cyclades Shear Zone (SCSZ). However, the structural evolution of the island remains controversial due to the preservation of opposing kinematic indicators, and complex overprinting relationships. This study re-evaluates the tectonic evolution of Ios through detailed field mapping, structural analysis, petrography, and in-situ white mica ⁸⁷Rb/⁸⁷Sr geochronology. Emphasis is placed on the relationships between folding, foliation development, shearing, and the nature of the contact between the Cycladic Basement and Cycladic Blueschist Unit (CBU). Field observations demonstrate that both units preserve a pervasive schistose foliation (S₂) that is cut by a regionally developed axial planar cleavage (S₃), which overprints mineral assemblages and mylonitized fabrics. Opposing top-to-north and top-to-south kinematic indicators occur within the same lithologies, structural domains, and are commonly preserved with folded fabrics. These relationships suggest that many apparent kinematic reversals result from structural rotation during folding rather than recording discrete episodes of opposing shear. White mica in-situ ⁸⁷Rb/⁸⁷Sr geochronology from both units suggests a similar exhumation history, where retrograde related recrystallization occurred between c. 30-20 Ma, matching similar ages previously published for the island. The CB-CBU contact lacks a consistent strain gradient, metamorphic discontinuity, and structural continuity expected of a crustal-scale detachment zone. Instead, it is interpreted as a folded lithological boundary that shared a common tectonometamorphic and exhumation history. A younger top-to-north Headland Shear Zone locally overprints earlier fabrics and represents the latest recognized phase of ductile deformation on the island. Collectively, these observations challenge traditional interpretations of Ios as a classical metamorphic core complex and highlight the importance of structural inheritance, polyphase deformation, and fold-related modification of kinematic indicators when reconstructing the evolution of extended continental crust.