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Essays on Environmental Economics
No full textThis dissertation investigates how diverse policy levers can drive the transition to a low-carbon economy. The first chapter uses dynamic system GMM panel estimation on U.S. electricity sector data (2000-2015), grounded in a theoretical framework inspired by the Directed Technical Change literature, to compare carbon pricing, clean energy tax incentives, and R&D subsidies. It finds that price-based instruments, such as carbon pricing and clean energy tax credits, induce a more immediate and pronounced shift toward renewable generation than R&D subsidies, underscoring the effectiveness of price signals in accelerating the energy transition. The second chapter develops a dynamic general equilibrium model to evaluate a broader suite of climate policies. These include carbon pricing, R&D subsidies, dirty investment taxes, and clean investment tax credits. Policies targeting high-emission sectors, notably carbon pricing, effectively cut emissions due to these sectors' significant market share, but may negatively impact economic prosperity. To balance emissions reduction and economic vitality, the essay proposes a clean "double dividend" strategy, using revenues from dirty-sector taxes to fund clean-sector incentives. This provides a balanced pathway toward reducing emissions while sustaining economic performance. Finally, the third chapter turns to monetary policy, using a structural vector autoregression to quantify how interest rate shocks affect CO₂ emissions across U.S. sectors. It finds that contractionary monetary policy produces a persistent yet transitory negative effect on total CO₂ emissions. These monetary policy shocks primarily affect industrial emissions while minimally impacting the residential and commercial sectors. Given central banks' limited capacity to directly influence environmental outcomes, monetary policy should thus be considered complementary to fiscal policy and environmental regulation in addressing climate change
Innovative Approaches to Natural Killer Cell Engineering: Overcoming Challenges in CRISPR-Cas9 Genome Editing, Transgene Expression, and Cryopreservation
No full textNatural killer (NK) cells, crucial players in the innate immune system, hold immense potential for cancer immunotherapy due to their ability to target malignant cells without prior antigen sensitization and their low risk of adverse effects such as graft-versus-host disease (GvHD), cytokine release syndrome (CRS), and neurotoxicity. Despite these advantages, challenges such as suboptimal gene-editing techniques, transgene silencing, and cryopreservation-induced dysfunctions have hindered their clinical application. Here, I addressed these hurdles by integrating innovative approaches: a one-step CRISPR-Cas9-mediated gene knockout paired with therapeutic genes such as chimeric antigen receptor (CAR) and interleukin (IL)-15 transgenesis, achieving simultaneously modified NK cell populations. To counteract transgene silencing, histone deacetylase inhibitors (HDACis) were employed, resulting in sustained CAR expression and enhanced anti-tumor efficacy against multiple myeloma in vitro and in vivo. Furthermore, optimized cryopreservation protocols implemented during the early expansion phase significantly improved NK cell recovery, viability, and versatility for therapeutic applications. By integrating advanced genetic engineering, epigenetic modulation, and optimized cryopreservation strategies, my thesis establishes a scalable and durable foundation for effective NK cell-based immunotherapies to treat a wide range of cancers
Investigating a Microgravity Earth Analog and the Effectiveness of a Nutritional Countermeasure with Machine Learning
No full textAs space travel advances, it becomes increasingly important to develop effective countermeasures against the negative consequences of microgravity exposure experienced by space travelers, such as bone density loss, muscle atrophy, cardiovascular issues, and the reactivation of dormant viruses. This work presents a machine-learning-based investigation of a nutritional countermeasure designed for and evaluated within a bed rest Earth analog. To improve the effectiveness of the data analysis, multiple transformations and normalization techniques are applied to the original dataset. Various classification models are then employed to assess the efficacy of the countermeasure and to identify physiological and molecular changes corresponding to different phases of the bed rest model. The analysis does not reveal any measurable and consistent effect attributable to the countermeasure. To demonstrate that the modest sample size of the bed rest data does not impose insurmountable limitations on the detectability of potential countermeasure effects, synthetic datasets of varying sizes are also generated and analyzed similarly
Impaired Fluoxetine-Induced Post-Stroke Depression Recovery in a Protocadherin αc2 Deficient Mouse Model
No full textPost-stroke depression (PSD) occurs in 30-50% of stroke patients and is associated with poor recovery, stroke recurrence, and increased death rate. Chronic SSRI treatment can recover the PSD phenotype in mice, but the mechanism of regrowth remains largely unknown. This study aimed to uncover the importance of protocadherin-alphaC2 (pcdhαC2), the main protocadherin isoform found in serotonin neurons, in PSD recovery. Previous studies have shown that knocking out pcdhα in serotonin neurons caused brain-wide tangling of serotonin axons and a depression- like phenotype. Pcdhαc2 knockout mice were used to assess baseline innervation differences, and then stroke recovery with or without fluoxetine (FLX) treatment.
Naïve pcdhαc2 knockout mice showed significantly impaired 5-HT innervation in the medial prefrontal cortex and hippocampus, with heterozygous knockout mice showing intermediate impairment. Stroke mice all exhibited significant anxiety and depression-like phenotypes post- stroke. Only wildtype mice properly recovered their depressive-like phenotype following FLX treatment, with only moderate recovery by heterozygous pcdhαc2 knockout mice. Stroke mice also had decreased 5-HT innervation in the medial prefrontal cortex and basolateral amygdala, with complete FLX-induced recovery only in the wildtype mice.
Taken together, these results indicate that in PSD mice depleted of pcdhαc2, chronic FLX fails to reverse the PSD behavioural phenotype and recover 5-HT innervation in key brain regions. This implicates pcdhαc2 in PSD recovery and could elucidate new targets to enhance neuroplasticity for recovery post-stroke
La chimie générale pour les Gee-Gees
No full textCe manuel a été conçu pour les étudiants inscrits au cours CHM1711 Principes de chimie à l'Université d'Ottawa
Essays on Labour Economics
No full textThe first chapter studies the labour force participation of older individuals during COVID-19. COVID-19 significantly changed the labour participation rates of older Canadians, leading to substantial flows among employment, unemployment, marginal attachment, and non-attachment. Using the Canadian Labour Force Survey (LFS), this paper examines the impact of these flows on the participation rates of older individuals and explores whether COVID-19 prompted early retirements. Unlike the Great Recession, the pandemic caused significant direct separations from employment to non-participation. Additionally, older women experienced slower participation rate recovery than men due to higher outflows and lower inflows. Notably, many individuals who initially became non-attached to the labour force in early 2020 transitioned back to employment in the following months of the same year. Generally, the pandemic did not increase older individuals' self-reported retirement transitions and reduced their probability of staying non-attached to the labour market.
The second chapter examines the cyclicality of worker flows across experience levels in Canada. Using the LFS, I estimate individual monthly transition probabilities over business cycles conditional on labour-market experience and job tenure. The job-finding rate and separation rate are relatively more cyclical for the youth. I find that experience is a major contributor to the cyclical fluctuations in employer-to-employer probabilities, whereas tenure is a major contributor to the cyclicality of employment-to-nonemployment.
The third chapter studies the evolution of the gender unemployment gap in Canada. The gender unemployment gap - defined as women's unemployment rates minus men's unemployment rates - was positive before 1990 but has remained negative since then. I decompose the gender unemployment gap into contributions from gender differences in transition flows between employment, unemployment, and non-participation. The results show that gender differences in flows between employment and non-participation have been positive contributors to the gap over time, while gender differences in employment-to-unemployment flows have been a significant negative contributor. Over the decades, the contribution of flows between employment and non-participation has been decreasing. As employment-to-unemployment flows continue to contribute negatively to the gap, the diminishing contribution of flows between employment and non-participation explains the flip of the gender unemployment gap from positive to negative. Furthermore, I find that differences in industry and occupation composition play a significant role in explaining the gender difference in employment-to-unemployment transition rates
Photosynthetic Adaptation of the Green Alga Chlamydomonas priscui to the Extremely Low Light Conditions of Lake Bonney, Antarctica
No full textÀ la demande de l'auteur, le résumé a été retiré en raison de la nature confidentielle de la thèse. Il sera ajouté une fois la période d'embargo terminée.
At the author’s request, the abstract has been removed due to the confidential nature of the thesis. It will be added once the embargo period has passed
Jugular Venous Height Measurement Through Contactless Monitoring
No full textHeart failure remains the leading cause of mortality worldwide, underscoring the urgent need for early diagnosis to improve patient outcomes and alleviate the burden on healthcare systems. One of the key indicators of heart failure is elevated Jugular Venous Pressure (JVP), which reflects increased venous pressure and fluid retention when the heart fails to pump blood effectively. Traditional methods of measuring JVP are often time-consuming and expensive. However, the advent of smartphones equipped with high-quality cameras and advanced processing units present an opportunity for a more efficient and cost-effective approach. This research proposes a novel framework utilizing machine learning and signal processing techniques to measure the JVP height in the neck through smartphone video recordings. The framework enables patients to capture and assess their JVP height by simply using their smartphones, offering a practical alternative to conventional methods. To evaluate the effectiveness of the proposed system, a dataset comprising videos of patients recorded from various angles and distances at a cardiopulmonary clinic was utilized. The algorithm’s performance in detecting JVP height was compared with assessments made by medical professionals using ultrasonic methods. The results demonstrate that the proposed system is comparable in terms of accuracy in JVP height measurement with expert’s evaluations. This advancement suggests a promising solution for improving the accessibility and efficiency of heart failure diagnostics, potentially transforming patient self-monitoring and reducing healthcare costs
Investigation of Advanced Effusion Cooling Technology for Gas Turbine Combustor Liner
No full textEffusion cooling represents the forefront of cooling technology for gas turbines, particularly within the hot-gas path components. Traditionally, effusion cooling holes are aligned with the combustor axis, resulting in a nominal zero compound angle, which is defined as the angle between the direction of the effusion jet and the mainstream flow in the lateral (transverse) plane. This alignment is based on the assumption that the swirling nature of the main flow does not significantly affect the cooling effectiveness. However, this study challenges this assumption by investigating the directional effects of effusion cooling under the influence of a swirling main flow, particularly focusing on the adiabatic film cooling effectiveness (AFE).
The research initially explores the isolated impacts of varying compound angles on AFE, deliberately excluding the influences of changing effusion hole spacing called effusion hole pitch. This approach facilitates a clearer understanding of how non-zero compound angles alone affect AFE. Building on this foundation, the study then examines the combined effects of varying pitch and compound angle, aiming to guide future designs of effusion cooling under swirling flow conditions. To achieve this, a novel effusion cooling design was proposed, featuring varying compound angles of 90, 60, and 30 degrees along the main flow direction. This design was compared against conventional methods with fixed compound angles.
Both experimental studies utilized Binary Pressure Sensitive Paint (PSP) and the heat/mass transfer analogy to measure AFE. The results indicate that larger compound angles facilitate quicker initial cooling film build-up, but optimal angles decrease downstream as the cooling film develops. The new effusion cooling design with varying compound angles demonstrated more uniform cooling film coverage and a slight enhancement in AFE compared to traditional designs with fixed angles. These findings suggest that reconsidering the standard alignment and angle of effusion cooling holes, particularly in the context of swirling main flows, can lead to significant improvements in gas turbine cooling efficiency
“Cancer changes everything, but it makes you wonder—am I still enough?” serial focus groups with adolescent and young adult cancer patients to understand experiences with cancer and sexual and reproductive health
No full textAbstract Background The impacts of cancer and its treatment on sexual and reproductive health among adolescents and young adults (AYA, ages 15–39) are not understood. We conducted a patient-oriented, novel serial focus group study to explore the sexual and reproductive health experiences of AYA cancer patients during and beyond treatment. Methods Participants (≥ 18 years) who were diagnosed with cancer between 15 and 39 years and reside in Canada were assigned to respective focus group cohorts based on shared characteristics (e.g., gender, cancer stage). Each cohort participated in three serial focus groups that emulated support groups, fostering a sense of community. Focus groups were co-facilitated with a patient research partner (PRP) and guided by a topic guide co-created with PRPs. Framework analysis involving steps of familiarizing with transcripts, identifying thematic framework, indexing data sections by theme, extracting and organizing data into charts, and analyzing charts, were applied to transcripts. Results Altogether, 48 AYA cancer patients, divided into 8 cohorts, participated in a total of 24 focus groups. Cohorts included: cis-gender women (n = 10), 2SLGBTQIA+ (n = 7), Black, Indigenous, and People of Colour (BIPOC; n = 7), cis-gender men (n = 6), breast cancer (n = 6), pelvic cancer (n = 6), diagnosed during adolescence (ages 15 to 19; n = 4), and stage 4 (n = 3) (one individual participated in two cohorts). Cohorts had representation of nonbinary and gender fluid participants (n = 4), non-heterosexual sexual orientation (n = 14), and racial diversity (n = 12). The final framework encompassed two thematic areas broadly categorized as patients’ experiences (“what is happening to them”) and their responses (“how they are reacting or acting”). The first thematic area (three themes), focused inward on the direct effects of cancer and its treatment on patients’ sexual and reproductive health. The second thematic area (three themes), looks outward at the external impacts, capturing how cancer affects aspects of patients’ sexual and reproductive health, including relationships, societal expectations, and community support. Conclusion Uncovering the profound and complex personal and interpersonal impacts of AYA cancer on sexual and reproductive health, our study has important implications for informing appropriate and affirming support