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Type d'Item : Item , Functionalized Alginate-Glutathione (GSH) Hydrogels as Antioxidant Biomaterials for Skin Wound Repair(Université d'Ottawa | University of Ottawa, 2026-08-07) Abdul Nour, Danielle; St-Pierre, Jean-PhilippeSkin serves as the body’s primary barrier against pathogens, UV radiation, and mechanical damage. When blood flow is impaired or pressure is maintained, skin and underlying tissues can deteriorate, forming chronic wounds such as diabetic ulcers, pressure sores, and venous leg ulcers. These wounds remain trapped in a state of inflammation, where excess reactive oxygen species (ROS) and pro‑inflammatory molecules disrupt normal healing processes. Hydrogels are widely used as wound dressings and can be enhanced with antioxidant components to reduce oxidative stress and help resolve the inflammatory phase of wound healing. In this study, alginate, a natural and biocompatible hydrogel polymer, was functionalized with glutathione (GSH), a natural antioxidant peptide of the human body responsible for reducing oxidative stress through ROS scavenging, via carbodiimide chemistry (EDC/NHS). The resulting conjugate is intended for the development of antioxidant dressings for the treatment of chronic wounds. The conjugate synthesis parameters ((EDC:GSH) molar ratio, pH, and reaction time) were optimized to maximize peptide content of the conjugates and thiol group availability for redox activity compared to a conventional carbodiimide chemistry method. Results showed that the (EDC:GSH) molar ratio and pH positively influenced GSH grafting, but negatively impacted reduced thiol group proportions, while reaction time had no significant effect. Optimal synthesis conditions were identified as: (EDC:GSH) = (4:1), pH = 5.0, reaction time = 2 hours. Chemical characterization of the conjugates using 1H-NMR and quantitative analyses through BCA and Ellman assays demonstrated the successful conjugation of GSH to the alginate backbone through an amide linkage. The conjugates were able to scavenge 50% of H2O2 when dissolved in solution but seemed to have lost their scavenging capacity once crosslinked ionically into hydrogels. Nevertheless, alginate-GSH conjugates could show promise as an antioxidant dressing material to accelerate the healing of chronic skin wounds.Type d'Item : Item , Essays on Fiscal Policy(Université d'Ottawa | University of Ottawa, 2026-08-07) John, Jenny Ebahi; Dissou, YazidThis dissertation examines how the effects of fiscal shocks vary across countries and economic conditions. The three essays analyze fiscal policy transmission in developing, resource-dependent, and advanced economies. The first chapter focuses on the time-varying effects of government expenditure shocks in six WAEMU countries using a Bayesian TVP-SVAR model with stochastic volatility. The findings show that government spending generally supports output, but the strength and persistence of this effect differ across countries. This indicates that even within a monetary union, fiscal policy effectiveness depends importantly on country-specific structural conditions, making fiscal design especially important where monetary autonomy is limited. The second chapter investigates the effects of oil revenue shocks in four African oilexporting economies using a hierarchical Bayesian panel VAR and country-specific structural VAR models. The findings show that oil revenue windfalls generate short run gains in government expenditure and output, but these effects fade within a few years and are accompanied by inflationary pressures and real exchange rate appreciation. This indicates that oil-driven fiscal expansions provide only temporary macroeconomic support and underscores the importance of institutions that smooth revenue volatility and strengthen resilience to external shocks. The third chapter studies whether the effects of government spending shocks on business investment depend on macroeconomic uncertainty in seven OECD countries using a threshold panel VAR. The results suggest that fiscal expansions crowd out business investment in low-uncertainty periods but have a more muted effect when uncertainty is high, indicating that private sector responses to fiscal policy may be state-dependent. More broadly, the findings are consistent with the view that the investment effects of fiscal policy depend not only on the policy shock itself, but also on the prevailing economic environment. Overall, this thesis shows that the effectiveness of fiscal policy cannot be reduced to a single multiplier or uniform transmission mechanism. Instead, the fiscal multiplier varies with structural characteristics and prevailing economic conditions. Taken together, the three essays provide evidence that institutional arrangements, resource dependence, and economic uncertainty influence the transmission of fiscal policy. Collectively, the findings suggest that the effects of fiscal policy are state-dependent, underscoring the importance of accounting for economic and institutional conditions when designing fiscal interventions rather than relying on uniform policy prescriptions.Type d'Item : Item , La coopération entre la cour pénale internationale et les États africains dans le cadre de l’émergence d’une justice pénale régionale(Université d'Ottawa | University of Ottawa, 2026-08-07) Havyarimana, Salvator; Paradelle, MurielLe Protocole de Malabo traduit des revendications régionales d’auto-détermination normative et de contextualisation des priorités judiciaires, notamment en intégrant des crimes économiques et environnementaux. Son adoption s’inscrit dans un contexte où la Cour pénale internationale (CPI), institution centrale de la justice pénale internationale contemporaine, souffre d’un déficit de crédibilité lié à une double fragilité : sa dépendance au Conseil de sécurité, dont les interventions sélectives et l’usage politisé du veto alimentent un sentiment d’instrumentalisation et une pratique judiciaire perçue comme visant principalement des dirigeants africains. Cette perception renforce la défiance de plusieurs États africains, malgré leur posture ambivalente. Cependant, cette ambition régionale est compromise par l’introduction d’une clause d’immunité au bénéfice des dirigeants en exercice, laquelle révèle une instrumentalisation politique visant davantage la protection que la justice : le mécanisme pénal régional semble être érigé en bouclier institutionnel au profit des dirigeants. L’absence persistante de ratification par ses principaux promoteurs accentue cette contradiction et interroge la portée réelle du projet. Inspirées par les TWAIL, les critiques des États africains dépassent un simple différend institutionnel : elles révèlent une tension entre souveraineté juridique africaine et exigences internationales de lutte contre l’impunité. La crise actuelle appelle à dépasser l’opposition stérile entre ces deux modèles pour instaurer un dialogue et une complémentarité à la fois fonctionnelle et normative. Cette thèse soutient que la légitimité future de la justice pénale internationale dépendra d’un pluralisme juridictionnel coordonné, conciliant universalité normative et émergence d’un système régional africain pleinement engagé dans la lutte contre l’impunité.Type d'Item : Item , Insights into Desiccation Resistance and Related Traits in Drosophila Melanogaster: Sex-specific Genetic Architecture and Selection(Université d'Ottawa | University of Ottawa, 2026-08-07) Levett, Callum; Rundle, Howard; Careau, VincentDesiccation resistance is a key determinant of insect survival in terrestrial environments. While desiccation resistance often differs between the sexes, its sex-specific quantitative genetic architecture remains incompletely understood. Prior work, either explicitly or as a function of experimental design, tend to focus on females, and quantitative genetic studies, using individual-based measures, are rare. Using a pedigreed population of Drosophila melanogaster, I took many individual measurements of desiccation resistance (survival under extreme desiccation stress) alongside three traits that may underlie variation in this – metabolic rate, locomotory activity, and dry body mass. This allowed sex-specific additive genetic (co)variances for these traits to be estimated using quantitative genetic animal models, as well as phenotypic selection gradients. All traits were heritable in both sexes, with evidence for sex differences in additive genetic variance and covariance structure. Genetic correlations among traits differed in magnitude and sometimes in sign between males and females, but the uncertainty around individual estimates were too large to infer statistical significance. Cross-sex within-trait genetic correlations were generally close to one, except for locomotor activity, suggesting some potential for independent evolutionary responses in males and females. Using survival time under desiccation as a proxy for fitness, I found pronounced sex differences in viability selection. Selection differed significantly between the sexes overall, driven primarily by differences in selection on metabolic rate and body mass. In both sexes, survival under desiccation stress was associated with lower activity and larger body mass. In males, survival under desiccation was also associated with lower metabolic rate, while there was no evidence of selection on metabolic rate in females. Correlational selection also differed between sexes, with males exhibiting a more complex fitness surface. These results show that desiccation resistance is a multivariate trait shaped by sex-specific genetic architecture and sex-specific selection, emphasizing the importance of incorporating sex and individual-level variation when studying desiccation resistance and its evolution.Type d'Item : Item , Calibration and Application of Biomarkers in Sediment to Track Paleoclimate and Large-scale Migratory Animal Population Dynamics(Université d'Ottawa | University of Ottawa, 2026-08-07) Dagodzo, Daniel; Blais, JulesThe primary objective of this thesis was to develop and apply lipid biomarker and isotope-based methods for reconstructing large-scale migratory animal populations and climatic histories in western North America from lake sediments. Specifically, this thesis aimed to (1) develop sterol and stanol biomarkers as quantitative proxies for Sockeye salmon escapement alongside the traditional lake sediment proxies (δ¹⁵N); (2) utilize sterols, stanols, and δ¹⁵N to track changes on large cormorant colonies on Lake Ontario Islands; (3) develop and validate lake-specific branched glycerol dialkyl glycerol tetraether (brGDGT) calibrations to refine paleotemperature estimates for Cultus Lake, British Columbia (BC); and (4) to reconstruct past temperatures using lake-specific brGDGT calibrations and assess their relationship with large-scale climate oscillations (Pacific Decadal Oscillation (PDO) and El Niño Southern Oscillation (ENSO)). I will then integrate these results with salmon escapement records and sedimentary δ¹⁵N dynamics from dated Cultus Lake sediment cores to evaluate how climate variability has influenced long-term salmon production. In Chapter Two, I applied sterol, stanols, and δ¹⁵N markers in sediment to track a sharp rise in cormorant population on Lake Ontario Islands. In Chapter Three, I developed novel sterol indices that strongly correlated with historical Sockeye salmon returns record in Alaska and BC, providing robust tools for reconstructing long-term Sockeye salmon population dynamics. In Chapter Four, I calibrated brGDGT distributions in soils, sediments, and water column samples from Cultus Lake, BC, establishing the first lake-specific temperature transfer functions in coastal BC. Chapter Five integrated lake-specific brGDGT-based temperature reconstructions with isotope (δ¹⁵N) based salmon proxies, revealing linkages between large-scale climate systems such as PDO, and ENSO variability, regional climate forcing, and salmon escapement trends over the past century. Together, these chapters demonstrated that lipid biomarkers and isotopes preserved in sediments provide high-resolution ecological and climatic archives, offering tools to disentangle the effects of climate oscillations and anthropogenic pressures on migratory animal populations and freshwater ecosystems. The overall conclusions of this thesis are: (1) sterol and stanol biomarkers provide reliable, independent proxies of Sockeye salmon escapement and can be used alongside traditional salmon proxies; (2) sterol, stanols, and δ¹⁵N signatures enabled the reconstruction of cormorant population and their ecosystem impacts from pond sediments; (3) lake-specific brGDGT calibrations significantly improved the accuracy and ecological relevance of paleotemperature estimates at Cultus lake; and (4) integrating biomarkers, isotopes, and climate indices strengthens our ability to assess the coupled dynamics of climate variability, nutrient cycling, and salmon populations across timescales.