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The Effects of Diet Quality on Developmental Plasticity of Size and Flight Energetics in the Hawk Moth Manduca sexta
No full textEnergy metabolism is one of the most widely measured structural backbones of physiological and life history traits, where variation in body size and morphology significantly impact flying insects' flight energetics. Both size and energy metabolism are a central feature of a species and individuals' ecology and evolution. In holometabolous insects, the larval stage of development is crucial in determining the final size of adults but also various body proportions. Generally, larger individuals will beat its wings during flight at a lower frequency. However, variations in wing proportions can affect wingbeat frequency, therefore affecting the energy that is required for flight. The flight muscles associated with the metabolic properties of flight vary with body mass and wing proportions, connecting morphological variation with muscle metabolic properties. To assess this, we experimentally induced developmental plasticity by subjecting Manduca sexta fifth instar larvae with varying intermittent starvation treatments: (1) controls being fed ad libitum; (2) our 'mild' group subject to intermittent feeding with 24 hour starvation periods between rations where animals are subject to intervals of one full day of feeding following one full day of starvation; (3) our 'severe' group subject to 48-hour starvation treatment where animals are subject to intervals of two full days of starvation followed by one full day of feeding. Our results show a significantly longer developmental period in mild and severe groups, along with significantly smaller sized larvae at wandering, pupae, and adults. Sexual dimorphism was observed in treated males showing morphological variation of body to wing proportions, along with reduced thorax size while females' morphological variation remained unchanged throughout nutrient restriction. Although males showed higher flight wingbeat frequency than females, wingbeat frequency did not change among treatments, along with showing no relationship between wingbeat frequency and body mass. Further, flight metabolic rate was not significantly different between treatment and sex. These findings suggest that individuals under nutrient-restricted developmental conditions can have a lasting impact on morphology, which may contribute to reduced flight capability, where males are more affected. Further research is needed to understand the metabolic and biomechanical thresholds that are responsible for successful flight under nutrient restricted individuals. These future investigations can provide insight into how developmental plasticity impacts flying insects in terms of energy balance and flight performance
Investigating the Therapeutic Potential of IAP Antagonism for the Treatment of Duchenne Muscular Dystrophy
No full textDuchenne muscular dystrophy (DMD) is a severe, X-linked genetic disorder characterized by progressive muscle degeneration and fibrosis due to the absence of dystrophin. Despite advancements in supportive care, current treatments remain palliative, underscoring the urgent need for therapies targeting fibrosis and inflammation to improve patient outcomes. While the role of inhibitor of apoptosis proteins (IAPs), particularly cellular-IAPs 1 and 2 (cIAP1/2) in skeletal muscle pathology are increasingly recognized, their specific contribution to muscle fibrosis and the inflammatory response in DMD remains poorly understood. This study investigated the therapeutic potential of LCL161, a Second Mitochondria-derived Activator of Caspases (SMAC) mimetic targeting cIAP1/2, in both adult and juvenile D2.mdx mice, a severe mouse model of DMD. Using a comprehensive approach combining functional, histological and biochemical analyses, I evaluated the impact of LCL161 on muscle pathology. In adult D2.mdx mice, LCL161 treatment showed marginal effects on muscle damage and strength, with a trend toward reduced fibrosis in the gastrocnemius muscle and modulation of the cytokine/chemokine profile. Conversely, juvenile D2.mdx mice exhibited reduced muscle damage without improved grip strength, accompanied by increased necrosis in the gastrocnemius and significant decreases in Tnfα and Pax7 expression. The muscle and age-dependent responses suggest that the therapeutic efficacy of LCL161 is influenced by the timing and severity of disease progression. This warrants further investigation into the mechanisms by which IAP inhibition influences muscle regeneration, inflammation, and fibrosis in DMD
Changing epidemiology of leptospirosis in China from 1955 to 2022
No full textAbstract Background Leptospirosis, a zoonotic disease caused by pathogenic species of the genus Leptospira, is an important public health concern globally. Leptospirosis has been notifiable under statute in China since 1955, and its epidemiological characteristics have evolved during near 70 years. This study aimed to describe the spatial and temporal patterns and demographic characteristics of leptospirosis from 1955 to 2022 in China, and explore the possible factors that influence leptospirosis transmission risk. Methods Wavelet time series analysis, global Moran’s I coefficients, space–time scanning statistics, and so on were used to analyze temporal, seasonal, geographic, and demographic trends in leptospirosis using reported national surveillance data from Chinese mainland from 1955 to 2022. Additionally, a Bayesian spatiotemporal model was used in a preliminary analysis to explore potential factors associated with leptospirosis occurrence. Results Between 1955 and 2022, China reported 25,236,601 leptospirosis cases, with 91% occurring from July to October. The annual incidence rate peaked at 38.28/100,000 during outbreaks in the 1960s–1980s but stabilized at a low level (0.07/100,000) between 2005 and 2022, with over 99% of cases in southern China. Clustering increased over time, being greatest during the period 2015–2022 (Moran’s I = 0.41, P < 0.01). Space-time cluster analysis indicated that the most likely clusters were in northern provincial-level administrative divisions (PLADs) from 1955 to 1984, in southern PLADs from 1985 to 2022. The main identified risk factors of leptospirosis occurrence were annual average precipitation (3.68, 95% CI: 2.50 to 5.12), GDP per capita (-3.70, 95% CI: − 5.97 to − 1.41), and the total power of agricultural machinery (− 2.51, 95% CI: − 3.85 to − 1.17). Conclusions Over past 70 years, leptospirosis in China has occurred as significant outbreaks but has ultimately declined to stable, low levels of occurrence. However, a clear north–south disparity persists, with tropical and subtropical regions in southern China remaining high-risk areas. The nearly 70-year dataset underscores the complex interplay of climate and socioeconomic factors influencing the disease’s occurrence. Targeted prevention and control measures are critical to prevent outbreaks, especially in regions prone to extreme climatic events like heavy rainfall and floods, which may signal the resurgence of leptospirosis
Éthos public au Québec et en Ontario des enseignantes voilées d'origine maghrébine
No full textEn plus des débats au sein d’instances juridiques fédérales, l’Ontario et Québec ont été secoués, au cours des dernières, par de nombreuses controverses portant sur les accommodements raisonnables touchant plus particulièrement les pratiques et coutumes musulmanes. Les questions relatives aux pratiques religieuses des communautés musulmanes ont été particulièrement débattues au Québec, qui adopte en 2019, la Loi sur la laïcité de l'État qui interdit le port de symboles religieux pour certaines fonctionnaires, dont les enseignantes, tout comme plusieurs pays de l'OCDE l’ont fait dans les dernières années. Dans une perspective disciplinaire d’administration publique, ces événements soulèvent des enjeux d’éthique au sein du secteur public et de gouvernance dans un contexte de société diversifiée.
Cette étude exploratoire vise à comprendre le sens que donnent les enseignantes des secteurs d’éducation publics ontarien et québécois à leurs expériences professionnelles, en rapport avec les contextes socioculturels dans lesquels elles évoluent. Ancrée dans une approche constructiviste sociale, cette thèse se penche sur l’expérience vécue et du sens qui émerge des interactions entre l’individu et son environnement. À travers un cadre conceptuel mobilisant l’éthos public, l'identité et la théorie de la reconnaissance, cette thèse propose d’analyser de manière approfondie les expériences et perceptions de ces enseignantes face à leur rôle professionnel et social, en lien leurs dynamiques sociopolitiques respectives. Cette thèse présente les résultats de notre recherche, issus d'entretiens semi-dirigés effectués en 2020 et 2021 avec des enseignantes musulmanes portant le foulard, issues de la première ou deuxième génération d’immigration et travaillant dans une école publique québécoise ou ontarienne. Cette recherche propose également une analyse thématique des données apportent des réponses quant à la manière dont les notions d’identité, de reconnaissance et d’éthos se manifestent dans les environnements de travail respectifs des enseignantes.
Les résultats de cette analyse portent à croire que le sens qui émerge de l’interaction entre l’éthos public, la reconnaissance, et l’identité trouve un écho profond en elle et nourrit leur passion pour l’enseignement. Ces facteurs s’entremêlent pour former un ensemble cohérent, les motivant à s’investir pour réduire les inégalités sociales, et ce, malgré les multiples défis auxquels elles font face et ainsi que les débats concernant leurs légitimités à occuper un poste. En somme, cette recherche vise à participer aux développements des connaissances en administration publique sur l’interaction entre l’identité culturelle et religieuse et l’emploi comme enseignante dans le secteur public
Policies on artificial intelligence chatbots among academic publishers: a cross-sectional audit
No full textAbstract Background Artificial intelligence (AI) chatbots are novel computer programs that can generate text or content in a natural language format. Academic publishers are adapting to the transformative role of AI chatbots in producing or facilitating scientific research. This study aimed to examine the policies established by scientific, technical, and medical academic publishers for defining and regulating the authors’ responsible use of AI chatbots. Methods This study performed a cross-sectional audit on the publicly available policies of 162 academic publishers, indexed as members of the International Association of the Scientific, Technical, and Medical Publishers (STM). Data extraction of publicly available policies on the webpages of all STM academic publishers was performed independently, in duplicate, with content analysis reviewed by a third contributor (September 2023—December 2023). Data was categorized into policy elements, such as ‘proofreading’ and ‘image generation’. Counts and percentages of ‘yes’ (i.e., permitted), ‘no’, and ‘no available information’ (NAI) were established for each policy element. Results A total of 56/162 (34.6%) STM academic publishers had a publicly available policy guiding the authors’ use of AI chatbots. No policy allowed authorship for AI chatbots (or other AI tool). Most (49/56 or 87.5%) required specific disclosure of AI chatbot use. Four policies/publishers placed a complete ban on the use of AI chatbots by authors. Conclusions Only a third of STM academic publishers had publicly available policies as of December 2023. A re-examination of all STM members in 12–18 months may uncover evolving approaches toward AI chatbot use with more academic publishers having a policy
Exploring the Dynamics of Muslim Conversion in Ottawa: Processes, Challenges, and Social Integration
No full textThis study explores the experiences of Muslim converts in Ottawa, with a particular focus on the processes of conversion, the challenges faced by converts, and their social integration within Canadian society. Through in-depth interviews with 15 converts, the research dives into the role of Islamophobia, societal stereotypes, and cultural identity in shaping the conversion experience. It examines how negative perceptions of Islam, such as the association with terrorism or the belief that all Muslims are Arabs, affect the decision to embrace Islam, and how converts navigate these stereotypes. The study also looks at the intellectual motivations behind conversion and how converts reconcile their new religious identity with their previous cultural and social contexts. Additionally, the research investigates the practical challenges faced by converts, such as adapting to Islamic practices, dealing with the language barrier, and finding appropriate support networks. By contributing to the literature on Muslim conversion, particularly within the Canadian context, this study highlights the need for greater support for converts, including access to educational resources, mentorship, and community-building initiatives, to foster a more inclusive and supportive environment for Muslim converts in Canada
Jet-O-mized Eggshell Membrane Powder: A Novel Hydrolysis Strategy to Unlock Gut-Promoting Bioactivities
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
Experimental Identification of High-Reward Nectar Plants for the Monarch Butterfly (Danaus plexippus)
No full textMonarch butterfly (Danaus plexippus) populations have significantly declined in the last 30 years. As a result, monarchs have been listed as 'Endangered' under Canada's Species at Risk Act, meaning conservation strategies must be developed and implemented to slow and reverse this decline. Monarchs migrate up to 5000 km from their breeding grounds in Canada to their wintering grounds in Central Mexico, with habitat loss and degradation occurring throughout their range. Consequently, restoration work is needed to increase monarch success across the continent of North America. Current work in Canada is focused on restoring grassland habitats with Asclepias spp. (milkweed species), the monarch's larval host plant, and nectar plants. While nutrient concentrations in nectar vary between plant species, little is known about the effects of nectar quality from different plant species on the performance of adult monarchs. For the most effective use of limited conservation resources, work must be done to identify the most beneficial nectar plant species for monarchs. For the migratory generation which does not breed, the effects of nectar on body composition have never been studied. This generation undergoes several physiological changes to build and maintain large fat stores for this journey, indicating that fat is a key factor for migration success. Consequently, I conducted an experimental study evaluating monarch butterflies' body condition (wet mass, fat, lean mass, and water mass) when foraging on one of seven nectar plant species for seven days. I found that nectar plant species significantly affected monarch fat mass, lean mass, and overall wet mass. These results indicate a need to carefully choose plants for restoration, as these choices could have implications for migration success. This study represents the first experimental test of the effects of nectar plants on monarch butterfly body composition, providing an approach for future studies to evaluate nectar plants across the monarch's range
Product Structure, Separating Systems, Freeze-Tag Problem, and Planar Multicolor Turan Number
No full textThis thesis is based on a collection of papers focused on graph theory and computational geometry.
The first paper focuses on the Product Structure Theorem for planar graphs, which asserts that any planar graph can be embedded in the strong product of a planar 3-tree, a path, and a 3-cycle. The paper presents a simple linear-time algorithm to find this decomposition for an n-vertex planar graph, improving on the previous O(n log n) time algorithm.
In the second paper, the concept of vertex-separating systems is explored, where a separating system is a collection of vertex subsets that is used to distinguish between any two distinct elements of the vertex set. The paper investigates the minimum size of vertex-separating path and tree systems for various types of graphs, including trees, grids, and maximal outerplanar graphs.
The third paper tackles the geometric freeze-tag problem, an optimization problem where the goal is to minimize the total wake-up time for a swarm of robots starting with a single active robot. The authors prove a conjecture by Bonichon et al. regarding an upper bound on the wake-up time for robots in convex position and provide an upper bound of 4.63r for robots located in a disk of radius r in the -norm, improving the best known bound of .
Finally, the fourth paper addresses the planar rainbow Turan problem, where the objective is to determine the smallest number of maximal planar graphs required on the same set of n vertices to guarantee a rainbow triangle (a triangle formed by edges from three distinct graphs). The paper establishes both upper and lower bounds, showing that a sequence of at least 0.75n planar graphs guarantees a rainbow triangle, and provides an almost linear lower bound using Behrend’s construction for three-term arithmetic progression-free sets.
Together, these works contribute to both theoretical and algorithmic advancements in graph decompositions, separating systems, and optimization problems within geometric and graph theoretic settings
Prison Pandemic Papers 2.0 – Manitoba
No full textThis dataset was collected through Access to Information requests submitted to the Government of Manitoba as part of the "COVID-19: Investigating Canada's Carceral Response to the Coronavirus through the Prison Pandemic Partnership" led by Kevin Walby (Full Professor, Criminal Justice, University of Winnipeg), Justin Piché (Full Professor, Criminology, University of Ottawa), and Abby Deshman (Executive Director, Canadian Civil Liberties Association). Initial triage of this dataset was undertaken by Mackenzie Plumb (PhD Student, Criminology, University of Ottawa).This research was funded by a Social Sciences and Humanities Research Council of Canada Partnership Engage Grant (1008-2020-0238)