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Graduate Theses and Dissertations

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This collections holds all University of Saskatchewan graduate level electronic theses and dissertations (ETDs) published since 2005. More than 700 print theses published before 2005 have been digitized and added to the collection as well.

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    Corporate Green Bonds, Stock Reactions, and Corporate Financial Performance in the U.S.
    (2024-02-29) Li, Woyang; Wilson, Craig; Yang, Fan; Maung, Min; Tannous, George; Fox, Kenneth; Mishra, Dev
    The rapid growth of green bonds highlights their increasing use as a financing tool for eco-friendly projects in response to the global environmental crisis and societal demand for sustainability. Our study, utilizing data from Bloomberg and the WRDS database, examines the relationship between U.S. companies’ green bond issuance over the past decade, its impact on stock market responses, and corporate performance to identify the driving forces behind such issuance. Our findings show that green bonds exert minimal impact on both short-term and long-term stock market reactions and investment returns. Interestingly, companies with lower environmental scores saw benefits in the form of positive firm valuations. This indicates profit maximization remains a dominant force in the U.S. investment landscape. The divergent expected firm values between non-financial and financial sectors suggest signaling theory as the primary motivator behind issuing green bonds. However, this trend, which allows companies who have lower ESG environmental scores or in non-financial sectors to reap greater benefits with minimal investment, could inadvertently promote greenwashing for issuers in these certain groups. This issue is tied to the current stage of development in Environmental, Social, and Governance (ESG) practices and related financial tools. The rapid growth of ESG activities, including green bond issuance, juxtaposed with the sluggish evolution of national policies, could potentially encourage greenwashing activities. Despite employing various methods to minimize biases, the limitations in sample size prevent us from entirely eliminating all potential influences. Therefore, further development in the corporate green bond market in the U.S. would help for researchers to get more comprehensive and reliable results.
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    Exploring the Catalytic Potential of Metal Nanoparticles Stabilized in Alternative Solvents for Transfer Hydrogenation Reactions
    (2024-02-28) Kainth, Money; Scott, Robert; Gravel, Michel; Burgess, Ian; Wilson, Lee
    Ionic liquids and deep eutectic solvents have emerged as promising alternatives to conventional solvents in catalytic processes as they possess low vapour pressure, high thermal stability, wide liquid temperature ranges, and tunable physicochemical properties. Moreover, palladium nanoparticles have garnered significant attention as versatile catalysts in hydrogenation reactions due to their unique properties and high catalytic activity. The utilization of nanoparticles in conjunction with ionic liquids and deep eutectic solvents has emerged as a promising strategy for enhancing hydrogenation processes. These composite systems offer unique advantages, including increased catalytic activity, improved stability in elevated temperature conditions, efficient mass transfer, and recyclability. Conventional direct hydrogenations in nanoparticle-ionic liquid composites often suffer from limitations such as low selectivity, mass transfer issues, tri-phasic catalysis, and the need for hazardous pressurized hydrogen gas. Room temperature transfer hydrogenation is a vital alternative catalytic sustainable process to direct hydrogenation for numerous organic transformations. This thesis explores the potential of using different alcohols, and ammonia borane as hydrogen donors for transfer hydrogenations using Pd nanoparticle catalysts in tetraalkylphosphonium halide ionic liquids, and urea-based deep eutectic solvents. The products of the catalytic reactions are analysed using 1H nuclear magnetic resonance. The characterization of the Pd nanoparticle catalysts in ionic liquids and deep eutectic solvents is performed using various techniques including transmission electron microscopy and X-ray absorption spectroscopy. The obtained results unequivocally showcase the remarkable catalytic activity and recyclability exhibited by the composite catalytic systems. Notably, these findings extend to diverse transfer hydrogenation reactions conducted at room temperature and reveal that the selection of hydrogen donor profoundly influences the reaction outcome, particularly in terms of product selectivity.
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    Enhancing Deep Learning Based Clone Detection
    (2024-02-27) Pinku, Subroto Nag; Roy, Chanchal K.; Mondal, Debajyoti; Roy, Banani; Stakhanova, Natalia
    The abstract of this item is unavailable due to an embargo.
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    Effects of Self-Efficacy Supporting Video Game Elements on Control Beliefs
    (2024-02-27) Samadi, Maryam; Klarkowski, Madison; Phillips, Cody; Stavness, Ian; Vassileva, Julita; Bath, Jon
    Self-efficacy---i.e., the perception of one’s ability to accomplish a specific task---is an important factor in developing motivation and showing resilience in facing challenges. This construct, along with perceived competence and dominance, makes up a collection of constructs we refer to as `control beliefs'. Control beliefs demonstrably enhance motivation, performance, and wellbeing outcomes. Despite control beliefs’ prominence in sports and personality psychology, the construct has yet to be explored holistically in games scholarship. The goal of this research is to create a theory-driven design framework to enhance player experience and wellbeing. To test the influence of self-efficacy and control beliefs on player experience outcomes, we developed a framework consisting of game elements associated with enhancing self-efficacy (SE) and integrated the elements into a bespoke game artifact, \textit{Space Oddity}. Subsequently, we conducted two studies, with the second study being more comprehensive than the first. In both studies, we implemented two conditions: one where players engaged with our game featuring the SE-supporting framework (SE condition) and the other without the framework (NSE condition). The first study showed that game enjoyment in the SE condition was significantly higher than in the NSE condition but self-efficacy was not different between the groups. In the second study, following exposure to one of two game conditions, 120 participants responded to inventories assessing enjoyment and player control beliefs. In the SE condition, we observed higher levels of perceived competence, dominance, and enjoyment. Additionally, domain self-efficacy was significantly higher in players with high baseline general self-efficacy (baseline GSE) than those with low baseline GSE. Our results also demonstrated increases in general self-efficacy and dominance for all participants, while domain self-efficacy increased among participants with low baseline GSE who were in the SE condition. Our findings illuminate the influence of SE-supporting elements in enhancing player control beliefs and enjoyment, contributing valuable design insight for reducing the perceived difficulty of challenging games.
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    Development of targeted radioimmunotherapy for osteosarcoma using a comparative oncology approach
    (2024-02-23) Prabaharan, Chandra Bose; Uppalapati, Maruti; Dadachova, Ekaterina; Kalra, Jay; Fonge, Humphrey; Freywald, Andrew; Valerie, MacDonald Dickinson; Dickinson, Ryan; Vorobyeva, Anzhelika
    This study sheds light on the potential of developing targeted antibody-based therapies for osteosarcoma (OS) - a malignant bone tumor that affects both canines and humans. Researchers focused on a cation-independent mannose-6-phosphate/insulin-like growth factor-2 receptor (IGF2R), known for its overexpression in various OS cell lines. They utilised phage display libraries to create antibodies that recognise IGF2R in human, canine, and murine models, including a promising antibody named IF3. The antibodies were then radiolabeled and characterised in vitro and in vivo using patientderived tumor models in SCID mice. The results demonstrated the specific binding of these antibodies to tumours and their potential for effective tumour uptake, which are crucial aspects of antibody-based radioimmunotherapy (RIT). An innovative aspect of the study involved using 177Lu-labeled IF3 in mice with canine-patient-derived tumors, which showed high uptake in both the tumor and spleen, leading to significant inhibition of tumor growth. However, the study also revealed spleen-associated toxicity, indicating the need for careful clinical evaluation in future applications. The findings from the use of IF3, both in its radiolabeled form and various animal models, hold promise for developing targeted antibodybased therapies for OS in both humans and canines. Further modifications to IF3 were made by engineering an amino acid substitution in the Fc region and creating IF3δ, demonstrating the potential for FcRn-mediated endocytosis and recycling. However, biodistribution studies in mice revealed unexpected spleen and bone accumulation, highlighting the distinct pharmacokinetics between mouse models and potential human and canine applications. Lastly, we used a cell-based phage display method to identify CB01, an antibody that selectively binds to OS cell lines with minimal affinity to normal cells. CB01's interaction with glycosaminoglycans (GAGs) revealed the crucial role of glycans in OS and posits GAGs as novel therapeutic targets. MicroSPECT/CT imaging underlined CB01's efficacy in tumor targeting and biodistribution, emphasising its potential in precise cancer treatment through RIT. In conclusion, this study makes significant strides in understanding and treating osteosarcoma, introducing novel therapeutic approaches and insights into the roles of IGF2R and GAGs in cancer progression. The development of IF3 and CB01 antibodies represents a promising advancement in targeted therapies, offering hope for improved management and treatment efficacy in osteosarcoma across species.
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    ANTIMICROBIAL PEPTIDES INSPIRED BY STAPHYLOCOCCAL PHENOL SOLUBLE MODULIN d-TOXINS
    (2024-02-22) Deeyagahage, Hiruni Kathyana; Ruzzini, Tony; Vederas, John; Chelico, Linda; Siqueira, Walter; Leung, Adelaine; Rubin, Joe
    The abstract of this item is unavailable due to an embargo.
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    OPTIMAL HOME OXYGEN FLOW RATE FOR INFANTS WITH BRONCHOPULMONARY DYSPLASIA
    (2024-02-20) Imran, Ahmad Ali; Adamko, Darryl; Daspal, Sibasis; Aneed, Anas El; Lawson, Joshua; Montgomery, Julia
    INTRODUCTION: Bronchopulmonary dysplasia (BPD) is one of the most common morbidities related to preterm birth. Infants with moderate BPD are discharged on supplemental oxygen to maintain oxygen saturation between 90-96%, avoiding both hypoxia and hyperoxia, each with its own morbidity. Pulse oximetry (POX) is used to measure oxygenation in the blood. Near-infrared spectroscopy (NIRS) is a potential method to measure cerebral oxygenation and brain perfusion. To the best of our knowledge, there is a lack of normalized data for NIRS values in neonate infants going home with or without oxygen. We proposed that with combination of NIRS and pulse oximetry we could better identify a safe oxygen flow rate/concentration for babies with BPD. In doing so, we also sought to determine what the normative values of NIRS are in premature infants. METHODS: This was a prospective cohort study approved by the Bioethics Board, University of Saskatchewan. Infants were recruited from the NICU, Jim Pattison Children’s Hospital after obtaining written informed consent. One group (Control group, n=22) of relatively healthy preterm infants were recruited for NIRS measurements in relation to standard POX. We then compared NIRS and POX values on varying flow rates (0.03, 0.06, 0.12 L/Min) for moderate BPD infants going on home oxygen (n=10). RESULTS: Of the control infants in room air, the average POX value was 97.8% with SD ± 1.661 and SEM ± 0.006. The average time of hypoxia with POX below 90% was 3.5%, while time above 96% was 96.5%. The average NIRS value was 78.24% with SD ± 7.705 and SEM ± 0.027. The NIRS values for this group showed time at <60% was 1.4% of the time, 60%-80% was 50.75% and >80% was 47.9%. As expected, the difference of means between POX and NIRS (POX – NIRS) was 19.56% with the 95% confidence interval of 19.503 to 19.61. Cohen's correlation coefficient was 0.02 between the two variables Pulse Oximetry and Near-Infrared Spectroscopy. One-sided and two-sided p-tests values were 0.00. For the group on oxygen, at the flow rate of 0.03 lpm the average time with POX <90% was 2.35%, with 90-96% was 15.52% and with > 96% was 82.13 %. Time for this group with NIRS values <60% were 0.01%, 60%-80% were 58.5% and > 80% were 41.5%. At oxygen flow rate of 0.06 lpm, the average time with POX <90% was 1.43%, 90-96% was 6.08% and > 96% was 92.49%. Time for this group with NIRS values <60% was 0.6%, 60%-80% was 65% and > 80% was 34.4%. At oxygen flow rate of 0.12 lpm, the average time with POX <90% was 1.46%, 90-96% was 11.54% and > 96% was 87.00%. Time for this flow rate with NIRS values <60% was 0.2%, 60%-80% was 64% and > 80% was 34.8%. Individually, we did not see POX desaturation events associate with NIRS desaturations. CONCLUSION: As expected, there is an approximate difference of 19.5% between the POX and NIRS values with POX being higher that NIRS in healthy infants. Individually, we could not find any correlation between POX and NIRS values for hypoxia events. On average, we did not see a dose response correlation between oxygen flow rate and time spent in the hyperoxemic range across different flow rates by POX or cerebral NIRS. While NIRS could play an important adjunct role in the NICU for brain oxygen saturation, NIRS data cannot serve as a stand-alone monitoring tool.
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    Analogue Computer Simulation of a Dragline
    (1962-10) Ochitwa, David W.; Nikiforuk, P.N.
    The purpose of this project was to derive a mathematical model which could describe the complete operation of a Marion Type 7800 dragline. This model could then be used for subsequent optimization studies leading perhaps to the fully automatic control of the digging operation. The dragline electrical equipment consisting of rototrols, generators and motors was, simulated on an analogue computer. The resulting steady state operations agreed very well with those of the actual dragline. Accurate definition of the load motion was difficult due to its highly nonlinear nature. Simulation of the nonlinear motion was made possible by the use of relays which altered the operating conditions as the analogue dragline cycle progressed. The results obtained indicate that a mathematical analysis, aided by an analogue computer, could be used to study dragline performance.
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    Large Language Models vs. Stack Overflow Solutions in Addressing Android Permission-Related Challenges
    (2024-01-17) Oishwee, Sahrima Jannat; Codabux, Zadia; Stakhanova, Natalia; Dutchyn, Christopher; Jin, Lingling
    The abstract of this item is unavailable due to an embargo.
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    Effectiveness of Whole Egg Versus Whey Protein Powder During Resistance Training
    (2024-02-12) Onwukwe, Victor Maduabuchi; Chilibeck, Phil D; Candow, Darren G; Zello, Gordon A
    The primary purpose was to compare the effectiveness of whole egg versus whey protein powder during 12 weeks of resistance training (RT) on lean tissue mass, and the secondary variables of muscle thickness, muscular strength, and blood glucose in resistance-trained adults. Seventy-one resistance-trained adults were randomly assigned to one of 3 groups while participating in a resistance-training program; Whole egg (WE; n = 23), whey protein (WP; n = 25), and placebo (PL; n = 23). Resistance training consisted of a three-day split (i.e., three days of training where separate muscle groups were trained for 1-1.5 hours each day interspersed with one day rest) for 12 weeks. All groups consumed the supplements (delivering 0.4 g/kg/d protein for WE and WP groups and 0.4 g/kg/d carbohydrate for PL) divided into boluses immediately after resistance training and 1 hour later. Before and after 12 weeks of resistance training and protein supplementation, lean tissue mass, fat mass, total body weight, body fat percentage (Dual Energy X-ray Absorptiometry [DXA]), muscle thickness (B-mode Ultrasound), muscle strength (bench press, leg press, knee extension), and fasting blood glucose level (glucometer) were assessed. There were no group x time x sex or group x time interactions for any of the dependent variables. There were time main effects, as expected for a resistance training program, with increases in lean tissue mass, muscle thickness measures, and strength measures (p < .05). When sex was removed as a factor to improve statistical power, there was a group x time interaction for bench press strength (p = 0.011). Bonferroni post-hoc testing showed that the change in bench press strength for the whole egg group (mean = 10.71, SD = 6.39 kg) was significantly different from the control group (mean = 5.56, SD = 7.65 kg) (p = .049), and the whey protein group (mean = 4.77, SD = 6.69 kg) (p = .015). In conclusion, neither whole egg nor whey protein powder supplementation improved body composition or strength during resistance training except for a greater increase in strength in the bench press with whole egg powder supplementation.
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    A Fault-Tolerant Design on Convolution Neural Networks by Applying Reconfigurable Processing Element Arrays
    (2024-02-09) Jin, Chen; Chen, Li; Ko, Seok-Bum; Zhang, Chris
    Convolutional neural networks (CNNs) implemented on field programmable gate arrays (FPGAs) have garnered significant interest due to their superior performance and flexibility, particularly during the inference phase following CNN model training on other platforms. The ability to customize the programmable logic (PL) section of the FPGA is the key factor driving the aforementioned performance and flexibility advantages. Moreover, recent trends in research have indicated that the parallel design of multiple processing element (PE) groups is becoming increasingly popular for implementing complex CNN designs. This approach offers a significant advantage over single PE or flat implementations, as it results in higher performance levels. However, increasing the number of PEs in a design can result in an elevated Single Event Upset (SEU) rate for designs operating in radiation environments. This is due to the vulnerability of the configuration memories in SRAM-based FPGAs. While memory refreshing can eliminate errors, the CNN may still produce incorrect results before SEUs are rectified. To address this issue, Triple Modular Redundancy (TMR) techniques are commonly employed to ensure correct operations. Nevertheless, this approach incurs at least 200% overhead in terms of resources, which can render it unsuitable for many complex neural networks that have high resource requirements. To address the resource limitations of TMR techniques, FPGA vendors offer Dynamic Partial Reconfiguration (DPR) methods that enable the repair of SEUs in specific regions of the configuration memories through partial refreshing without the need for additional hardware resources in the FPGAs. DPR allows for the reconfiguration of a portion of the FPGA while the rest of the device continues to operate normally. This technique can also be applied to TMR-protected CNN designs to reduce refreshing time. However, it does not alleviate the area overhead associated with TMR methods. In this thesis, a CNN was designed and implemented in a FPGA with multiple parallel PE array groups serving as computing engines, with each group working independently. Prior to the start of computation, self-testing was performed on each PE array to verify its functionality. If any faults were detected, DPR was conducted to correct the errors in the configuration memory of the affected PE array.The experiments in this thesis evaluated the performance of a single PE group without any reinforcement design as a control group using both error injection and laser experiments. Subsequently, more PE groups were added to determine whether the system could handle more SEUs or laser pulses before an error occurred. In the result, for non-critical errors where the CNN incorrectly estimates the percentage of a given output number, adding DPR can result in a 13.8 times improvement in cross-section. In cases where the CNN makes critical errors and predicts the input number incorrectly, adding DPR can improve the cross-section by 25 times. Additionally, the overall accuracy of the CNN remains consistently above 99% even after a large number of laser pulse or fault injections, indicating the robustness and reliability of the model. The key novelty of this study is the use of DPR to improve the overall fault tolerance of the entire CNN by taking advantage of the parallel processing capability of the PE arrays to perform data processing without faulty PE arrays. This approach significantly reduces area overhead compared to TMR methods. Experimental results demonstrated the effectiveness of the proposed method.
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    Cultural Continuity as a Pathway for Métis Peoples Health Promotion: A Descriptive Phenomenological Approach
    (2024-02-09) Diaz Vega, Maria Jose; Groot , Gary; Carr, Tracey; Turner , Tara; Barreno , Leonzo; Janzen , Bonnie
    The Métis Peoples, a distinct group of Indigenous Peoples in Canada, have historically faced adverse consequences from colonialism. Disconnection from their land, cultural suppression, and loss of cultural identity have had adverse effects on the health outcomes and overall well-being of the Métis population. Considering the critical importance of cultural continuity as a health-protective factor for Métis people, this thesis explored Métis people's lived experiences of culture and cultural continuity and the connection with health and well-being. The present thesis used secondary data from a research project titled "Preventing Cancer Through Métis Cultural Revitalization: A Framework for Saskatchewan." Data included twenty four semi-structured interviews with Métis citizens (12 females and 12 males, average age of 47 years) regarding their health and culture. Descriptive phenomenology was used to guide the secondary analysis of the interview data. The analysis revealed that some participants discussed cultural disconnection, while others emphasized active participation in Métis culture, which resulted in the promotion of cultural aspects such as traditional practices, language, and connection to the land. These elements were essential for re-establishing identity, nurturing a deeper connection to heritage, and potentially providing health benefits, including stress relief, a sense of belonging, and pride. The findings contribute to a greater understanding of the role of culture and cultural continuity in promoting health and well-being among Métis people. The results are an addition that could guide future research endeavors with other Métis communities that aim to explore health promotion through cultural continuity.
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    PROTEOGLYCAN MODULATION OF BMP SIGNALLING IN ENDOCHONDRAL AND INTRAMEMBRANOUS OSSIFICATION: INSIGHTS FROM ZEBRAFISH CRANIOFACIAL AND FIN REGENERATION
    (2024-02-09) Koosha, Elham; boughner, Julia; Eskiw, Christopher; Papagerakis, Petros; Collins, Michelle; Graf, Daniel
    During the early stages of embryo development, the formation of the skeletal system is carefully controlled by specialized growth factors that are secreted locally. One such group of growth factors is known as bone morphogenetic proteins (BMPs), which serve multiple functions and play crucial roles in the maturation of cartilage and the differentiation of osteoblasts. To transmit the BMP signals from the cell membrane receptors to the nucleus, two pathways are involved: the canonical Smad pathway and the noncanonical p38 mitogen-activated protein kinase (MAPK) pathway. The extracellular regulation of BMP signalling occurs through interactions with proteoglycans (PGs) present in the extracellular matrix (ECM). These PGs generally modulate the efficiency of binding between the ligands and their receptors. During the process of endochondral ossification, which involves bone formation through cartilage, chondrocytes (cartilage cells) produce an ECM abundant in PGs. Following the formation of cartilage, bone formation occurs in the surrounding perichondrium as certain chondrocytes express Indian hedgehog (Ihh), a factor that induces osteoblasts, while undergoing a precisely regulated maturation process. Interestingly, the PG-rich ECM somehow inhibits the maturation of cartilage, including cellular hypertrophy and the expression of Ihh and Col10a1 genes. Given that BMPs are known to promote cartilage maturation, I hypothesize that PGs normally act as inhibitors of BMP signalling. To investigate this hypothesis, using various experimental manipulations we evaluated BMP signalling in chondrocytes of both wild-type zebrafish and zebrafish with a mutation in the PG gene fam20b-/-, which encodes a kinase responsible for phosphorylating xylose in the GAG side chain. The results showed that the levels of phosphorylated Smad1/5/9 (p-Smad1/5/9) were increased only when mutant fam20b chondrocytes secreted PGs, while the phosphorylation of p38 (p-p38) remained unaffected. As anticipated, the levels of p-Smad1/5/9 decreased in chondrocytes treated with DMH1, an inhibitor of the BMP receptor kinase domain, and in chondrocytes of zebrafish with a dominant-negative BMP receptor (dnBMPR). Only treatment with DMH1, and not the dnBMPR condition, reduced p-p38 levels in the chondrocytes. However, in both DMH1-treated and dnBMPR zebrafish the expression of two markers of chondrocyte maturation, ihha and col10a1, was decreased, and formation of perichondral bone was diminished. Next, to confirm the regulatory role of PGs in BMP-dependent cartilage maturation and in the timing of endochondral ossification, we were able to rescue the early expression of ihha and col10a1 genes as well as the formation of perichondral bone in fam20b mutant zebrafish by treating them with either DMH1 or dnBMPR. These rescue findings supported the hypothesis that PGs normally inhibit canonical BMP-dependent cartilage maturation, thereby influencing the rate and onset time of endochondral ossification. Additionally, we hypothesized that PGs typically inhibit BMP signalling during the process of intramembranous (or dermal) ossification, where bone tissue develops directly from mesenchymal cells without the presence of a cartilage precursor. We investigated the development of dermal bones in the craniofacial region of zebrafish to further test our hypothesis. Using a Tg(5xBMPRE-Xla.Id3:GFP)ir1189 transgenic zebrafish line that exhibits green fluorescent protein (GFP) expression in response to BMP signalling, the involvement of BMP signalling in the development of ossified dermal elements was confirmed. However, when embryos were treated with DMH1, the development of craniofacial dermal bone remained unchanged. While most craniofacial dermal bones of fam20b-/- zebrafish showed no discernible differences in their formation during embryonic development, we did observe an early initiation of dermal bone formation derived from the perichondrium, specifically in the dentary and quadrate bones. To test the hypothesis further, the process of fin regeneration was used as an additional model for investigating intramembranous ossification. Through the analysis of GFP expression in two BMP-responsive reporter lines, namely Tg(5xBMPRE-Xla.Id3:GFP)ir1189 and Tg(BMPRE:EGFP)pt510, a relationship was observed, linking the GFP signal as an indicator to the development of bony rays during fin regeneration. Furthermore, regeneration of caudal fin dermal bony rays in fam20b-/- zebrafish was not impaired. In adult zebrafish, the repercussions of DMH1 treatment were clear as it significantly hindered the regenerative capacity of adult fins, supporting the involvement of BMP signalling in this process. Overall, this study demonstrates the inhibitory role of PGs in BMP signalling during cartilage maturation and the influence of PGs on the rate and onset time of endochondral ossification. Furthermore, this study unveils a novel observation, the early formation of dermal bones originating from the perichondrium in fam20b-/- zebrafish mutants.
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    Root System Response of Lentil to Varied Nitrogen Availability: Insights from Positron Emission Tomography (PET)
    (2024-02-09) Subedi, Abinash; Lamb, Eric; Arcand, Melissa; Stewart, Katherine; Congreves, Kate; Yost, Christopher
    Studying plant root system growth responses and carbon allocation is difficult due to the opaque nature of the soil. Novel imaging techniques such as positron emission tomography (PET) where the plant roots can be visualized in-situ can overcome those shortcomings. However, PET is a challenging technique to implement due to the lack of a standard workflow. Thus, the objectives of this research were 1) to develop a repeatable workflow for PET using lentils as a test crop species and 2) to use PET imaging to examine the response of lentil seedling roots to a gradient of soil nitrogen levels. Multiple preliminary experiments were conducted to set parameters such as dosing rate, and dosing time to develop a PET workflow to obtain three-dimensional images of the root system. It was found that dosing a lentil plant with 2 GBq of 11C-CO2 for 30 minutes, followed by 60 minutes of acclimatization in the growth chamber, produced an optimal 3D root system image. When fertilized with urea, 20-day-old lentils grown under higher nitrogen levels had a lower number of active first-order lateral roots and a lower root-to-shoot biomass ratio. This indicates that the roots use less carbon, and more carbon is allocated to the shoots when the nitrogen level in the soil is high. Morphologically, a lower number of fine total root length was seen with high nitrogen which contradicts previous findings. One factor that has not been considered is the change in root birth or death rate response (i.e., demographic response), in high nitrogen conditions. At high nitrogen conditions, the death rate of the fine roots increased, and so did fine root branching, leading to less total root length. Under low nitrogen treatment, total root length was higher due to the higher longevity of roots in nutrient-scarce conditions. Thus, this research highlights the possibility of PET imaging in understanding carbon allocation in lentil root system to varied nitrogen availability through a standard PET imaging workflow established by this experiment.
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    Renewable Energy for Sustainable Arctic Communities: A Framework for Conceptualizing RE Projects as Drivers of Sustainable Development
    (2024-02-07) Ward, Josie Katherine; Poelzer, Greg; Noble, Bram; Reed, Maureen; Zapata, Oscar; Dickinson, Harley
    Rural Northern communities often struggle to build and maintain sustainable economies. The current models of economic development often do not provide paths to long-term sustainable communities. Concurrently, the concept of human development and wellbeing in the Arctic is being reimagined beyond traditional economic indicators, which drives the need for new projects and industries that can support local economies and contribute to overall community wellbeing. Community renewable energy (CRE) projects have been proposed as a driver of sustainable development in the Arctic and globally. Research on CRE projects has highlighted many hypothesized socio-economic benefits. However, there is a limited understanding of the mechanisms that generate these socioeconomic benefits. This thesis seeks to identify the mechanisms that make CRE projects drivers of sustainable development in rural Northern communities by advancing a CRE model, called the community renewable energy framework, informed by a nation building approach and the concept of creative class. The nation building approach highlights the importance of self-governance, competent governing institutions, cultural match, and long-term planning are instrumental. These factors provide the foundation for deriving socioeconomic benefits from CRE but it is not sufficient to motivate a new future in Northern communities. The creative class concept, with critical adaptations, can be applied to CRE projects to extend their impact beyond the direct benefits and motivate sustainable development through the creation of a local creative class. Finally, this conceptual framework is applied to a community in Northern Norway. This thesis contributes to the body of research highlighting the potential of CRE projects to motivate sustainable development in Northern communities.
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    Creating and Measuring High Brightness Synchrotron Radiation Beams Using Interferometric X-ray Optics at the CLS
    (2024-02-01) Simonson, Nicholas A.; Boland, Mark; Ghezelbash, Masoud; Urquhart, Stephen; Bourassa, Adam; Chang, Gap Soo
    This thesis presents the work done with two types of interferometric X-ray optics, namely a Fresnel zone plate (FZP) and a double slit interferometer or synchrotron radiation interferometer (SRI). For the first project, FZPs were modelled, designed, fabricated, and visually inspected with the aim to increase the brightness of the soft X-ray beam on the Spectromicroscopy beamline (SM) at the Canadian Light Source (CLS). The devices were fabricated and visually inspected for quality in this work, but not yet tested with X-rays. This work demonstrates the possibility of rapid and in-house FZP fabrication for the CLS soft X-ray beamlines. In a second set of experiments, SRI X-ray optics were used on SM to measure the first order transverse spatial coherence of the synchrotron radiation. This SRI experiment served as a proof-of-principle measurement of transverse electron beam profiles with narrow transverse beam sizes, which will be necessary for fourth-generation light sources such as CLS2 [1]. The use of zone plates and upgrading to a fourth-generation light source will increase the speed at which scientists can do their experiments.
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    Extending Ice-Jam Flood Hazard Assessment Systems to Ungauged River Reaches with the Application of Dendrogeomorphological Methods
    (2024-01-31) Lubiniecki, Teagan I; Laroque, Colin P; Lindenschmidt, Karl-Erich; Rokaya, Prabin; Ireson, Andrew
    Throughout spring and fall, ice jams can occur in cold-region rivers, which may lead to flooding. When temperatures rise and flooding occurs, ice can be pushed onshore, damaging vegetation, riverbanks, shoreline ecosystems, and anthropogenic infrastructure. To help understand the outcomes of ice-jam flooding, ice-jam flood hazard assessments systems have been developed. Currently, ice-jam flood-hazard assessments rely on gauged river data to assess flooding. However, many rivers that are at risk of ice-jam flooding do not have gauges, so current hazard assessment methods are less accurate in these areas. The research conducted in this thesis determines whether dendrogeomorphological data, such as tree scars, can sufficiently replicate the long-term gauged data required for ice-jam flood-hazard assessments. Dendrogeomorphological data were collected near Prince Albert, Saskatchewan. Tree-ring data were analyzed to estimate flood dates based on the tree scars from past ice-jam flooding events. Tree scar heights were measured relative to the river water stage level to determine the water level heights of past scarring events. The dendrogeomorphological data were compared with the recorded gauged river data collected from the city of Prince Albert to assess the accuracy of the former. After the flood-stage data were collected in the field, a stage-frequency distribution was calculated and compared with the current stage-frequency distribution derived from the gauged data. The frequency distribution created from the dendrogeomorphological data could now be used in current ice-jam flood-hazard assessment systems in future research. Any uncertainties identified in the distribution were also investigated. Results showed that staging of an ice-jam flood event with a return period of 10 and 100 years were found to be 412 m a s.l. and 414 m a s.l, respectively. The new technique has the potential to improve the current limitations of ice-jam flood-hazard assessments, and advance hazard predictions in river regions with limited data, benefitting many remote communities impacted by ice-jams.
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    Torrefaction and Steam Explosion of Selected Biomass for Biofuel Production
    (2024-01-31) Onyenwoke, Chukwuka Austine; Tabil, Lope G; Dumonceaux, Tim; Cannayen, Igathinathane; Mupondwa, Edmund; Cree, Duncan; Adapa, Phani; Karunakaran, Chithra
    Lignocellulosic biomass has demonstrated great potential as feedstock for pellet production, notwithstanding the fact that the industrial production of pellet is faced with some economic challenges. Pretreatment research has been focused on identifying, evaluating, developing, and demonstrating promising approaches that enhance the physiochemical and mechanical properties of biomass. Assessment of biomass pretreatment processes depends on a parameter called the severity factor, which is defined as the combined effect of temperature and residence time. This study summarizes pretreatment processing methods, namely, steam explosion and torrefaction of selected biomass feedstocks (sawdust and oat straw), processing characteristics, and product properties. The study also discusses the economics of densifying biomass, outstanding challenges, the potential for industrial applications of biomass-pretreated products, and global trends in biomass utilization. Steam explosion pretreatment of sawdust and oat straw was conducted under 3 stages: mild, medium, and severe conditions. The effects of temperature, time, and moisture content on the physiochemical and mechanical properties of pellets formed were examined. The p-values of the regression models for all the response variables (dimensional stability, tensile strength, and pellet density) studied were significant (p < 0.05), except for the pellet density of steam-pretreated oat straw pellets. The interaction of these three factors did not significantly affect the response variables of oat straw pellets. Microstructural examination of the pellets from steam-pretreated biomass revealed that the material contained particles that were more closely bonded and featured a cemented surface with fewer pores when compared to particles from untreated oat straw and sawdust. Microwave-assisted torrefaction was conducted on white spruce sawdust (WSS) at temperatures of 200 °C, 250 °C, and 300 °C and retention times of 5 min, 7 min, and 9 min in an inert environment. Torrefaction pretreatment is a mild form of pyrolysis that has the potential to produce high-quality raw material for making biofuel that serves as a replacement for coal in the bioenergy industry. The torrefaction process produces a solid carbon, commonly known as biochar, and condensable (torrefaction liquid (TL)) and non-condensable gases. In this study, torrefaction characteristics were investigated to observe its effects on the thermal and physiochemical properties of the pellets produced. During the torrefaction process, a significant mass loss associated with the decomposition of hemicellulose was observed. The hemicellulose content drastically reduced to approximately 1.8% from 19.25% and the cellulose content was reduced by approximately 10%, while the lignin gained approximately 35% as the severity increased. This led to an improvement in the higher heating value (HHV), hydrophobicity, bulk, particle density, pellet dimensional stability, and pellet density. However, the pellet tensile strength decreased as the torrefaction severity increased. Therefore, to enhance the tensile strength of the pellets, the introduction of a binder was necessary. Torrefaction liquid and sawdust were used as additives at different proportions during pelletization. The addition of binders (torrefaction liquid and sawdust) to the pellet formulation increased the tensile strength of the torrefied WSS by approximately 50%. The OH groups in the biomass break down to a limited degree due to dehydration. This hinders the formation of H bonds, thereby increasing the chances that the pretreated biomass will become hydrophobic. The Scanning Electron Microscope (SEM) graphs showed that the torrefied WSS pellets demonstrated more firmly glued surfaces with fewer pores spaces when set side by side with the raw pellets. The thermogravimetric analysis conducted showed that the torrefaction of WSS slightly reduced its thermal stability. Technoeconomic analysis of six case scenarios (wood pellet production from raw sawdust in a pellet plant (I), straw pellet production from raw oat straw in a pellet plant (II), integrated torrefied treated sawdust pelletization plant utilizing the torrefaction liquid (TL) as the pellet binder (III), integrated torrefied treated oat straw pelletization plant utilizing the torrefaction liquid (TL) as a pellet binder (IV), integrated steam treated sawdust pellet plant (V), and integrated steam treated oat straw pellet plant (VI)) was carried out to develop a process model for pellet production from sawdust and oat straw that uses torrefaction and steam explosion pretreatments prior to pelletization. The breakdown of equipment purchase cost showed that the torrefaction reactor is the most expensive unit with about 51% of the purchase cost. Scenarios 1, 2, 5, and 6 generated positive net present value at baseline model. Facility-dependent and feedstock costs were the major significant contributors to the pellet production cost. The minimum selling price of pellets obtained from Scenarios 1-6 were $113.4/t, $118.7/t, $283.4/t $298.7/t, $200.5/t, and $208.4/t, respectively. The profitability of pellet production as determined by the net present value (NPV), internal rate of return (IRR), and payback period was found to be sensitive to variations in feedstock cost.
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    Comparison Between Distance Element Method and High Speed Discriminating Method in Loss of Field Protection
    (2024-01-30) Xu, Ben; Gokaraju, Rama; Karki, Rajesh; Mohamed, Ebrahim B
    The abstract of this item is unavailable due to an embargo.
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    Human Rights, Culture, and the Law: Strategies to Indigenize Responses To Gender Discrimination and Sexual Violence Against Women in Igbo Communities in Nigeria
    (2024-01-30) Okondu, Victory Chika; Buhler, Sarah; Odumosu, ibironke; Vandervort, Lucinda; Lavallee, Jaime
    Gender discrimination and sexual violence have long been aspects of the lived experience of women in eastern Nigeria. Over the past three decades, both the international community and the Nigerian government have taken steps to eliminate discrimination against women. Despite these efforts, Nigeria, like most countries in Africa, still struggles to recognize, let alone implement, the human rights of women to live free from gender discrimination and sexual violence. This experience raises questions about gaps in the implementation of human rights in the context of women’s lived realities in Nigeria. In this thesis, I examine the contributions legal statutes, international laws, and regional regulations have made to improving the lives of women in the Igbo communities in eastern Nigeria and find that the law falls short in addressing the practical aspects of implementation. I acknowledge that international and domestic laws constitute a potentially valuable framework for addressing violations of women’s rights but believe the application of legal approaches alone is limiting and ineffective. To this end, I argue that meeting the challenges faced in implementing human rights laws that guarantee women’s rights to equality and freedom from gender discrimination and sexual violence requires adoption of culturally grounded and contextualized approaches. Women’s human rights laws are more apt to gain meaningful acceptance at all levels, from the community to the highest courts, when they are implemented by grass roots institutions that are rooted in the culture. Accordingly, I recommend that traditional leaders, whose legitimacy as custodians of Igbo culture is unquestioned, assume a central role in interpreting and reinterpreting the meaning and significance of cultural values and norms that shape and, in turn, are affirmed by cultural practices. I further suggest that cultural reinterpretation can: (1) discern and incorporate the underlining purpose of most cultural practices; (2) promote and enrich inter-group gender dialogue; and (3) transform and enrich the cultural competency training required by legal professionals and others involved in securing the human rights of women. This multi-faceted approach will gradually transform cultural understanding at the grass-roots level and among professionals and the courts, and in due course lead to international recognition of culture as a valuable resource in the implementation of women’s human rights.