Master's Theses

Permanent URI for this collectionhttps://hdl.handle.net/10294/2901

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Open Access
Meteorological risk assessment of Canadian transcontinental freight railway: Case study of Saskatchewan and Ontario
(Faculty of Graduate Studies and Research, University of Regina, 2023-08) Bahramimehr, Mehrnoush; Khan, Sharfuddin; Khondoker, Mohammad; Ruparathna, Vithanapalpita Koralalage Rajeev Jayanga
Railway transportation is the heart of the supply chain in Canada. The reason is that railway transportation is known as one of the most reliable and safest modes of transportation. However, due to its complexity, a wide range of risks are associated with this means of transportation. Considering Canada's climate, studying meteorological risks associated with the railway network can be useful for decision-makers in railway transportation, especially when preparing for cold seasons and implementing railway network development. In this study, a comprehensive spatial analysis using ArcMap has been applied to identify hotspots and vulnerable geographical areas in terms of meteorological factors in two provinces with slightly different climates: Saskatchewan and Ontario. Floods, rain, snow, minimum temperature, and wind have been selected as factors to generate meteorological risk maps for the mentioned provinces. The selected railway network for analysis is the Canadian National Railway (CN), one of the two major railways in Canada and the only Transcontinental Freight Railway in North America. However, the results can be applied to any other railway network in Canada. After developing risk maps for each factor, 5 different types of integrated risk maps are generated in this thesis. The first type assumes that the weight (importance) of all factors in causing accidents or service disruptions is the same. Two versions utilize different weights for different factors. One version applies score-based weighting of factors, while the other employs expert opinion-based Analytical Hierarchy Process (AHP). Additionally, two season-based risk maps for warm and cold seasons are also generated. The risk maps demonstrate hotspots and hazardous areas that require more attention and planning to maintain the continuity of the supply chain. The results can be used to enhance safety, reduce service disruptions, and ensure the smooth operation of the railway network.
Open Access
Classifying ovarian cancer using machine learning methods
(Faculty of Graduate Studies and Research, University of Regina, 2023-11) Rahman, Rushda; Peng, Wei; Henni, Amr; Muthu, S. D. Jacob
Ovarian cancer is one of the most fatal cancers for women nowadays. It is ranked as fifth most common cancer deaths among women resulting more deaths than any other cancers in female reproductive system. According to Canadian Cancer society that about 3000 ovarian cancer patients were detected, and among them 1950 patients died in 2022 which indicating more than 50% of mortality rate. Ovarian cancer is mainly generated from cancerous ovarian tumour. So, it is very important to classify cancerous tumour from noncancerous tumour to prevent false positive for ovarian cancer. Moreover, if cancerous tumour is diagnosed in early stage, it can be prevented from spreading and thus survival rate for ovarian cancer can be increased. Also, by separating cancer patients from benign tumour patients, it will be easier for doctors to know the stages of the cancer and know patient’s prognosis and life expectancy. The principal and initial objective of this thesis is building a feasible system using Artificial Intelligence which is easy to use and compatible to classify ovarian cancer. Proposed study will give a new non-conventional way to classify ovarian cancer from ovarian tumour which will be affordable for the patients. Moreover, one of the primary benefits of this study is that doctors/physicians can detect ovarian cancer with only blood test/ serum test. There is no need to do any expensive tests such as: ultrasound, MRI or CT-Scan. The main concept of this research is the application of several machine learning techniques to correctly classify ovarian cancer and finding best technique among those in terms of Accuracy, Precision, Sensitivity, and Specificity. Original dataset is taken from website named Kaggle (https://www.kaggle.com/). This dataset is screened, cleaned and normalized first and then expert’s advice has been taken to extract the most important features to do the correct classification. Later, a correlation test has been done for better understanding of the relations and independency among the input features. 10 input features have been selected including age, menopause, CA-125, AFP, NEU etc. From correlation test result 7 inputs were taken again and a comparison had been made between 10 inputs and 7 inputs. And the output is TYPE which denotes 1 for benign ovarian tumour and 0 for ovarian cancer. Four machine learning models have been used for classification and they are, ANN, SVM, Naïve Bayes, and k-NN. Training of each model is performed and after training, each algorithm is tested and hence performance is calculated and compared. After analysing results, it is found that for the problem considered, the Artificial Neural Network (ANN) is the best classifier in terms of accuracy giving 85.91% accurate results on test data whereas SVM, NB and k-NN gave accuracy of 76.05%, 83.09% and 76.06% respectively. In terms of sensitivity and precision calculation, Naïve Bayes is best, and the ANN Classifier is second best algorithm. Taking specificity into Consideration, the ANN is best with 87.50%. Keywords: Machine Learning Classifier, Ovarian Cancer, Benign Ovarian Tumour, Artificial Intelligence, Artificial Neural Network (ANN), Support Vector Machine (SVM), Naïve Bayes (NB), k-nearest Neighbour (k-NN), Confusion Matrix.
Open Access
Carbon capture, utlization, and storage supply chain risk management framework development
(Faculty of Graduate Studies and Research, University of Regina, 2023-12) Kabir, Md Ainul; Kabir, Golam; Kahn, Sharfuddin; Tontiwachwuthikul, Paitoon
Technology called Carbon Capture, Utilization, and Storage (CCUS) is important for capturing CO2 emissions before they get into the air. Because everyone wants to stop global warming by reducing CO2 emissions, CCUS is an important and emerging technology that can help slow down climate change, lower emissions in many areas, and support the move to a sustainable and carbon-neutral future. As CCUS technology and its adaptation increases, it is very important to pay attention to the CCUS risks from the supply chain (SC) point of view. The ultimate goal of this study is to is to identify CCUS supply chain risks and develop a framework that provides a structured approach to ensure safe and reliable CCUS supply chain. This study develops a complete CCUS SC risk management framework including CCUS SC functions, risks and risk management strategies. Therefore, this study analyzes the literature related to SC of different sectors and identifies the SC risks which is the foundation for CCUS SC risks identification. This study depicts that there is no research article that provides a comprehensive CCUS SC risks as well as risk management framework that connects with risk management strategies. Moreover, the framework provides a guideline for future research which enrich the CCUS supply chain risk management system as well as fight against the climate change. This study has deployed Delphi technique to validate the risks that have been identified from the literature. In addition, principal component analysis (PCA) has been used to identify the communalities of the risks related to the CCUS SC functions. At the same time, 44 risk management strategies have been developed from the supply chain risk management literature in relation with the CCUS SC risks. Finally, the risk management framework has been developed in CCUS SC context which is the main objective of this study. This is the first risk management framework in CCUS SC context which connects the CCUS SC functions, risks, and strategies. This framework provides a comprehensive guideline for the management to develop sustainable roadmaps in CCUS SC management systems. Moreover, this framework helps to prevent the environment and promotes further research in CCUS risk management systems. Keywords: Carbon Capture, Utilization, and Storage (CCUS); Supply Chain (SC); Supply Chain Risk; Risk Management (RM); Principal Component Analysis (PCA), Risk Management Strategies.
Open Access
Preferences and experiences of interdisciplinary communication across hospital unit types: A survey of three health professions in a Regina, Saskatchewan hospital
(Faculty of Graduate Studies and Research, University of Regina, 2024-03) Morrissette, Alana Marie; Camillo, Cheryl; Zarzeczny, Amy; Mou, Haizhen
In the literature, interdisciplinary communication has been linked to high quality patient care, reduced medical error and improved patient and care provider satisfaction. Information sharing, role clarity, and shared goal setting amongst care providers are also attributed with interdisciplinary communication. The Accountable Care Unit (ACU) is an innovative, microsystem-based approach to inpatient hospital care that incorporates distinct features facilitating interdisciplinary collaboration and communication including: geographic co-location of a physicians’ patients and Structured Interdisciplinary Bedside Rounds (SIBR). During SIBR, care providers meet at the patient’s bedside and use a standardized communication protocol to provide and receive information. Traditional hospital wards, on the contrary, lack such features and intentional design. While existing research has separately explored outcomes of ACUs and aspects of interdisciplinary care, no known study has assessed healthcare providers experiences with interdisciplinary communication on ACUs versus traditional wards. The overarching purpose of this study was to understand perceived differences between interdisciplinary communication on traditional medicine wards and ACUs. The research questions that prompted this investigation included: 1. What are the experiences and perceptions of interdisciplinary communication on ACUs at the Pasqua Hospital by nurses, pharmacists and physicians who have previously worked on a traditional medicine ward? 2. How do participants perceive interdisciplinary communication on an ACU versus a traditional ward? 3.Do common themes emerge amongst research participants with similar demographics or professions? The first ACU in Canada was implemented in 2016 on unit 4A at the Pasqua Hospital in Regina, Saskatchewan to reduce lengths of stay, decrease mortality rates, and improving patient and staff satisfaction. In the following years, additional ACUs were implemented at the Pasqua Hospital and in other Saskatchewan hospitals. This research was carried out via an online survey that offered 9 demographic questions and 6 qualitative questions pertaining to interdisciplinary communication both generally, on ACUs, and on traditional wards. The survey was administered from July 13 2022 until October 31 2022 to physicians, pharmacists and nurses who volunteered to participate and who had work experience on both types of units. Fifteen respondents completed the survey and responses were analyzed using descriptive statistics and thematic analysis. Participants of this study reported an overall positive and enhanced experience with interdisciplinary communication on ACUs, generally finding it more effective than on traditional units. Reasons for this included structured communication amongst multiple care providers, regionalization of patients within the hospital with consistency in care providers, respect, and role clarity. Conversely, participants reported interdisciplinary communication to be more difficult on traditional units due to a lack of structure, absence or unavailability of team members, professional silos, hierarchies and egos. With the exception of respondents’ profession, correlations between demographic information, such as gender or age, and thematic codes proved to be inconclusive. The findings of this research could assist in guiding policies that adopt techniques or models, such as microsystem-based care models and scheduled, structured interdisciplinary rounds, which foster improved interdisciplinary communication and teamwork on acute care medicine wards. The implementation of such approaches could improve staff satisfaction, retention, and patient safety, while reducing liability risks and medical errors. Future researchers may consider investigating ACUs at other sites while acquiring more in-depth demographic information of increasingly diversified participants.
Open Access
Design, development, and control of an off-road hybrid electric vehicle power system
(Faculty of Graduate Studies and Research, University of Regina, 2024-01) Hedayat Pour, Mehdi; Mehranddezh, Mehran; Stilling, Denise; Kabir, Golam
With global warming and climate change threatening the planet, the auto industry is transitioning from conventional internal combustion engines to electrical power trains. Globally, electric vehicles and hybrid electric vehicles are becoming popular with 10 million cars sold in 2022. Electrification is not limited to the personal cars and public transport, but includes applications in transportation, mining, and military. The power system and battery pack are the main components of electric and hybrid electric vehicles. Battery pack capacity and performance affect the overall mileage. This thesis models and sizes the battery pack based on the mechanical and electrical specifications of the vehicle. The control algorithm is the heart of an unmanned, remote controlled, electric vehicle. This work presents a combined control strategy for an unmanned hybrid electric vehicle using a Joystick. The control algorithm consists of a dynamic controller designed using the mechanical modeling of the vehicle combined with an electrical control strategy known as Field Oriented Control. The proposed technique generates the torque and speed signals using dynamic model of the vehicle and trajectories applied to the model. These signals are then utilized by the inverter controller in the vehicle's power system. The proposed algorithm generates excellent results based on trajectory following and can guarantee the safe operation of the battery pack without over discharging the battery higher than its nominal discharge rate to provide longer lifespan during harsh operations. The simulation results show that the vehicle can operate in different road conditions without violating the discharge limit of the battery pack, while following the input trajectories. The highest discharge currents are associated with the toughest road conditions and shorter terminal time during which the vehicle should reach the desired speed applied through the trajectories. The proposed control algorithm can be applied to other vehicular application by taking their specific mechanical behaviors and characteristics into account. Keywords: electric vehicle, hybrid electric vehicle, power system, battery pack, field oriented control, dynamic modeling
Open Access
Exploring experiences of mental health and well-being with post-secondary students in rural Saskatchewan
(Faculty of Graduate Studies and Research, University of Regina, 2025-05) Thomas, Sophia Marie; Fletcher, Kara; Jeffery, Bonnie; Gebhard, Amanda
This study explored the mental health and well-being experiences of post-secondary students in rural Saskatchewan as there is limited research pertaining to this population. Semi-structured interviews were conducted with three participants from different rural locations in Saskatchewan who were currently attending a regional college and willing to discuss their experience of mental health and well-being. This study was informed by principles of Narrative Inquiry and a thematic analysis led to the development of four main themes: feelings, prioritization, accessibility, and stressors. The students’ shared stories provided perspective on the experience of mental health and well-being of post-secondary students living in rural Saskatchewan. The knowledge shared also provided insight on how to approach supporting this student population with their academic success, reducing stressors, developing positive coping strategies, and accessing effective resources. Keywords: post-secondary, off-campus, rural Saskatchewan, mental health, social work
Open Access
Paramedic students and their mental readiness for fieldwork
(Faculty of Graduate Studies and Research, University of Regina, 2024-12) Sudom-Young, Simone Kathleen; Eaton, Andrew; Novik, Nuelle; Carleton, Nicholas
The present research elicits the mental health preparedness of paramedic students, in relationship to preparedness by their academic institution for fieldwork. Paramedic student’s mental health preparedness has not been extensively explored; improved understanding could result in better mental health services for paramedics-in-training. Paramedics are at a heightened risk for psychological distress. The research, led by a social worker, elicited paramedic student experiences prior to experiencing psychological distress. The research was conducted in Canada’s Prairie provinces, although no Manitoba participants opted to take part in this research. For the research, 43 participants completed the 12-question survey on study eligibility and mental health resiliency. Alberta accounted for 72% (n=31) of participants, and 28% (n=12) were from Saskatchewan. In total, 24 participants agreed to participate further in a Zoom focus group. The research used a phenomenological methodology, and the shared essences of paramedic student’s mental health preparedness were drawn from six focus groups. From those focus groups, four themes emerged. Resiliency as a coping strategy was believed to be developed from birth, as well as an emphasis on how experiences relating to emergency services can impact resiliency. The lack of standards for mental health supports in paramedic training programs were discussed. The need for effective communication with enhanced open learning was expressed. The importance of increased mental health information and recommendations for the future were emphasized. The research explored whether new paramedic students felt they were mentally prepared for the career to which they were soon embarking. Keywords: focus groups, mental health preparedness, paramedic students, phenomenological methodology, social work
Open Access
Alcohol and social work: Context and meanings
(Faculty of Graduate Studies and Research, University of Regina, 2024-10) Redekop, Erin Violet; Fletcher, Kara; Albert, Jason; Sorensen, Michele
There is little research available about alcohol use among social workers in Canada. This mixedmethodology study seeks to address gaps in research regarding alcohol use among social workers in Saskatchewan. Social workers in Saskatchewan were invited to participate in an online survey that collected quantitative data including demographic information, alcohol consumption, adverse childhood experiences, and professional quality of life. Qualitative data was collected using semi-structured interviews to capture the meanings social workers attribute to their experiences of alcohol use. The survey found that the overall alcohol consumption of Saskatchewan social workers may be lower than that of the general Canadian population. The survey also found find higher rates of adverse childhood experiences and mental health issues among Saskatchewan social workers than the general Canadian population. The qualitative interviews found that social workers in Saskatchewan worry about the potential negative consequences of alcohol use as a coping mechanism for stress and feel a dissonance between perceived social norms of alcohol use and what alcohol use means to them in their role as social workers. Key words: Social work; alcohol use; alcohol misuse; Saskatchewan; mental health
Open Access
A multi-proxy environmental and limnologic paleo-reconstruction of two lakes in Southern Saskatchewan recording the past 6,700 cal. years BP based on ostracods
(Faculty of Graduate Studies and Research, University of Regina, 2025-03) Velandia Bahamon, Maria Juliana; Velez, Maria; Robbins, Leslie; McBeth, Joyce
Paleoenvironmental and paleolimnological reconstructions are of great importance to understand future responses of the environment to climate change and environmental stress. Two lake archives, Deep Lake and St. Denis – Pond 1, are used to understand past environmental and limnological conditions in the northernmost part of the Great Plains of North America. Climatic conditions are inferred from the lake sediments and the ostracod assemblage for the Mid- to Late-Holocene (6,700 to 120 cal. yr BP). Mainly, dry conditions with shorter wetter conditions prevailed during the Mid-Holocene as suggested by the presence of a depositional hiatus from 6,302 to 4,366 cal. yr BP and evidences for wetter periods inferred from the bulk-sediment chemistry (Al, Si, K, Fe, K/Ti, Fe/Ti and Mn/Ti), the stable isotopes (ẟ18O, ẟ13C), and the trace element composition of the ostracod valves (Mg/Ca, U/Ca, Fe/Ca). The Late-Holocene displays overall centennial cyclicity fluctuations between wet and dry periods but mostly dry during the last 2,000 years. Both Deep Lake and St. Denis – Pond 1 records seem to respond to regional changes although the period between 2,714 and 1,691 cal. yr BP appear to be responding to local rather than regional forcings due to the moist signature that presents like some but not all the lakes in the northern Great Plains. Likewise, the Medieval Warm Period is recorded by the record of St. Denis – Pond 1, in which dry conditions were inferred.
Open Access
Community-based programming for families and children with disabilities
(Faculty of Graduate Studies and Research, University of Regina, 2025-02) Silljer, Rachelle Kathleen; Hopper, Tristan; Genoe, Rebecca; Mang, Cameron
Leisure and recreation are known to positively impact families and children with disabilities. Leisure is defined as an activity that participants take part in when they are free from the demands of other responsibilities. However, opportunities for individuals with disabilities to take part in leisure activities in the community can be limited. The purpose of this research is to explore the experiences of families and children with disabilities in community recreation programming. To obtain participants’ perspectives the study was done using a constructivist viewpoint, and a qualitative descriptive design. Data were collected from four families using both one-on-one interviewing and larger connection groups. Thematic analysis was used to analyze the qualitative data. Three main themes were identified as the largest barriers to inclusion: attitudes, opportunities, and acceptance. Participants experienced barriers based on the views of other attendees, their caregivers, their self-doubts, and their coaches. The participants expressed the need for intervention and expressed how assistance in accessing community-based recreation could reduce these barriers. Keywords: disability, inclusion, family, acceptance, opportunity, attitudes.
Open Access
Proportional hazards modelling for current lifetime data
(Faculty of Graduate Studies and Research, University of Regina, 2025-03) Sembukuttige, Himansi Vihanga Kumari; McVittie, James; Deng, Dianliang
Current lifetime data represent a unique subset of length-biased data where only the times from the initiating event to the cross-section date are observed without follow-up. We propose an efficient estimation procedure to fit the semi-parametric proportional hazards model using current lifetime data. This estimation procedure is based on the EM algorithm which has two versions based on the support points of the non-parametric baseline hazard function. We apply the method to simulated data and Parkinson’s disease current lifetime data drawn from the Canadian-Open Parkinson Network (C-OPN). We estimate the effects of clinical and epidemiological covariates using the proportional hazards model on the survival of subjects with Parkinson’s disease.
Open Access
The germ game design framework for user engagement, retention, and monetization
(Faculty of Graduate Studies and Research, University of Regina, 2025-04) Sachdeva, Parul; Hamilton, Howard; Butz, Cory; Uddin, Md Sami
Many video game development teams passionately pursue innovative concepts they believe will appeal to users, often resulting in well-crafted games as products. However, despite the creativity and effort of the teams, the resulting games frequently fail to realize their full audience potential and economic viability. This thesis presents the GERM framework to enhance user engagement, retention, and monetization in video games. The framework is named GERM, which is short for Game Engagement, Retention, and Monetization, to emphasize its focus on strengthening these three foundational areas. The framework elements are a Multi-Objective Goal Generator, Reward System, Timer Scheme, Social Dynamics, Enhancers, Obstructors, Monetization Design, Analytics Design, Impression Design, and Novelty. The framework was devised following a comprehensive review of successful video games, experience in the video game development field, and a study of the psychological factors relevant to game success. Following a concise description of each component of the framework, the thesis discusses the Phased Integration methodology, which is a five-phase process for applying the framework during game development and enhancement. In the first phase, the Assessment Phase, a game is evaluated using the Game Assessment (GERMAF) form, which scores the game across the elements of the GERM framework. This scoring identifies areas needing improvement, which guides attention to weaker points in the Engagement, Retention, and Monetization strategies. Next, the Engagement Phase targets elements that directly influence player engagement, establishing a foundation for sustained interest in the game. The Short-term Retention Phase then addresses elements focusing on player retention during the early stages of player engagement. The Monetization Phase focuses on the game’s monetization design elements to increase profitability. Finally, the Long-term Retention Phase focuses on strategies that promote extended player retention, such as planned updates and dynamic content. A case study was conducted on a live game named One Shot Golf, which faced challenges in user retention and overall profitability. The game’s engagement, retention, and monetization features were evaluated using the GERM Assessment form (GERMAF). This assessment identified areas for improvement across the game. Several features were proposed and discussed with the game’s design team. In conclusion, this thesis presents a comprehensive framework for enhancing user engagement, retention, and monetization in video games. The framework extends beyond current industry practices and encourages game developers to innovate and tailor strategies aligned with their game’s design and audience. Future research could test the applicability of this framework across diverse game genres. The applicability of the framework to software design could also be investigated.
Open Access
Neurophysiological mechanisms of dual-tasking in people with multiple sclerosis
(Faculty of Graduate Studies and Research, University of Regina, 2025-02) Plandowski, Kristen Elle; Mang, Cameron; Donkers, Sarah; Barden, John
Saskatchewan has one of the highest rates of multiple sclerosis (MS) globally, affecting approximately 4,000 people within the province. An emerging topic of study within MS rehabilitation is dual-tasking (i.e., the performance of two tasks simultaneously). Reports on dual-task performance among people with MS (PwMS) vary in the literature, with past research limited by methodological differences and minimal consideration of the underlying neurophysiology. Studies suggest that changes in inhibitory neural activity in the motor cortex may support dual-task performance in healthy adults, as assessed by transcranial magnetic stimulation (TMS) techniques. Other TMS work indicates that MS alters corticospinal inhibition, but how and whether it is modulated during dual-tasking in PwMS is unknown. The primary objective of this cross-sectional study was to determine whether changes in corticospinal inhibition that occur during dual-tasking are different in PwMS compared to non-MS controls. Six PwMS (4F; 45.17 ± 15.74 years) and three non-MS controls (2F; 42.33 ± 16.62 years) participated and performed motor and cognitive tasks under single-task and dual-task conditions. Each dual-task included a core motor task, which involved maintaining a pinch grip at a steady-force level. Performance of this core motor task allowed for assessment of corticospinal inhibition during task performance via measurement of the cortical silent period elicited by TMS. Tasks combined with the core motor task included holding a string of numbers and/or number letter combinations in working memory and a foot-tapping task. Several versions of these tasks were presented alongside the core motor task, each providing different levels of task novelty and complexity. Dual-task performance was measured as a dual-task cost with consideration of task performance and cortical silent period duration. Several key findings emerged from this exploratory study: i) PwMS demonstrated only minor negative impacts to cognitive performance under dual-task conditions, with some indication of a ‘cognitive-first’ prioritization strategy, ii) both PwMS and non-MS controls generally displayed some level of an interference effect on force-grip performance indicated by negative dual-task costs; and iii) PwMS displayed greater changes in cortical silent period dual-task costs that were particularly apparent under the motor-motor dual-task conditions. Findings from this study indicate that while PwMS and non-MS controls may experience similar performance changes during dual-tasking, it appears that the neurophysiological mechanisms may be different. Future work should continue to investigate the impact of MS-related changes in the corticospinal system on dual-task performance.
Open Access
Role of erythritol catabolism by Rhizobium johnstonii in the rhizospheres of lentil, pea, and vetch
(Faculty of Graduate Studies and Research, University of Regina, 2024-10) Nasrollahishirazi, Mina; Yost, Christopher; Cameron, Andrew
Legumes are known for their high protein content and ability to improve soil fertility. They form a symbiotic relationship with rhizobia through exchange of signaling molecules and plant exudates, such as carbon sources, which, in turn, enable biological nitrogen fixation through the formation of nodules. In the rhizosphere, the environment around the roots, bacteria compete against each other for root colonization and nodulation. Rhizobium johnstonii is capable of catabolizing erythritol, a known pea root exudate. Previous deletion mutation of the catabolic genes (Yost et al., 2006) created strains unable or with reduced ability to grow on media containing erythritol as a sole carbon source. Subsequently, the mutant strains were impaired in their ability to compete against the wild type to colonize pea root cells. In this study, I expanded the investigation to include lentils and vetch, alongside pea, to assess competition between wild type and mutant strains in different legume plants. It was determined that erythritol catabolism is important for Rhizobium for successful colonization and nodulation of all three legume species. In this research, I demonstrate that the capacity to catabolize erythritol is an important trait that is required across all these three plants. Previous deletion mutations in the transporter genes resulted in strains with reduced growth rates compared to the wild type when grown on minimal medium with erythritol as the sole carbon source. Non-specific transporters can sometimes facilitate the uptake of similar molecules, even if they are not the primary substrate, although their involvement in erythritol uptake remains unclear. To further explore this, I employed an IN-seq library and TRANSIT analysis, but these approaches did not reveal any additional specific transporters responsible for erythritol uptake in Rhizobium johnstonii bv. viciae VF39sm mutants. The IN-Seq approach may not be effective for identifying erythritol transporters due to the redundancy of alternative transporter systems. Additionally, metabolic flexibility and compensatory mechanisms might explain the observed growth on erythritol, as bacteria are able to adapt by upregulating various transporter pathways under selective pressure. In 2022, Mullock observed the upregulation of rhi genes (rhizosphere induced genes involved in a quorum sensing system) in Rhizobium johnstonii bv. viciae 3841 when growing on erythritol and compared the results with growth of this strain on mannitol, suggesting that erythritol may act as a signaling molecule in the rhizosphere. Now the key question is whether erythritol functions as a signaling molecule in the rhizospheres of lentil, pea, and vetch plants, in addition to serving as a carbon source. To investigate the role of erythritol as a signaling molecule rather than solely a carbon source, I integrated rhiA promoter-gusA fusions into wild type, catabolic and transporter mutant strains to measure gene expression through the GUS assay. rhiA is part of the rhiABC operon, which is involved in the quorum sensing system of Rhizobium and plays a role in the regulation of genes associated with rhizosphere-induced proteins. While β-glucuronidase activity was detected, it did not show consistent trends in expression patterns across strains. Therefore, further investigation is suggested to characterize the role of erythritol as a signaling molecule for regulation of genes not involved in erythritol catabolism.
Open Access
Towards root cause analysis in hybrid dynamic domains
(Faculty of Graduate Studies and Research, University of Regina, 2025) Mehmood, Asim; Khan, Shakil M.; Zilles, Sandra
Reasoning about actual causes of observed effects is fundamental to the study of rationality. As such, this important problem has been studied since the time of Aristotle, with formal mathematical accounts emerging recently. We live in a world where change due to actions can be both discrete and continuous, i.e., hybrid. Yet, while there has been extensive research on actual primary and indirect causes in discrete dynamic domains, only few recent studies address causation in such hybrid domains. Building on recent progress, in this thesis I propose a first definition of primary cause in a hybrid temporal action-theoretic framework. My proposal is limited to primitive observations/effects. I also show how a variant of my definition can be interpreted from a counterfactual perspective and hint how the account can be modified to work with conjunctive/disjunctive effects. My proposal is set within a hybrid variant of the situation calculus. I show that my formalization has some basic intuitive properties.
Open Access
Geochemical analyses of amber associated with dinosaur bonebeds in central North America
(Faculty of Graduate Studies and Research, University of Regina, 2024-10) McWilliams, James Scott; Velez, Maria; McKellar, Ryan; Robbins, Leslie
For a long time, amber has been praised for its ability to preserve organic inclusions in spectacular detail. More recently amber has been analysed from a geochemical point of view, to gain a better understanding of the environments in which this fossilized tree resin was produced. Due to lack of fossils and detail in known paleo-environments three meters below the Cretaceous-Paleogene (K-Pg) boundary, amber geochemistry helps to fill in a gap of the fossil record. This study consists of the analysis of carbon and hydrogen stable isotopes from amber in bone beds, as well as Fourier Transform Infrared Spectroscopy (FTIR) and more traditional means of paleontological and sedimentological analysis from sites in Saskatchewan, Alberta, Montana, and North Dakota. The main aim is understanding how this geographic region of the world was changing during the Cretaceous period. Results indicate that Cretaceous ecosystems, during the last 15 million years of the Cretaceous, were relatively quite stable; however, the δ13C values leading up to the Cretaceous-Paleogene extinction boundary appear to show that many of the geographic region’s resin producing plants were experiencing some form of ecophysiological stress. They also indicate that the Western Interior Seaway underwent transgressions and regressions throughout the Cretaceous and that it was still actively playing a part in the terrestrial ecosystem’s precipitation up until the end of the Cretaceous period, although with varying degrees of influence. Finally, the data indicate that throughout the Cretaceous the main amber producing plants were trees from the Cupressaceae family. Using the geochemical information from amber along with the sedimentological and paleontological data from each of these sites, details of the environments leading up to the end Cretaceous extinction event can be constructed.
Open Access
Learning hypertrees with shortest path queries
(Faculty of Graduate Studies and Research, University of Regina, 2025-01) Maliuk, Valerii; Zilles, Sandra; Yang, Boting
One branch of computational learning theory focuses on algorithms for learning discrete structured objects from queries. In this context, we consider the problem of learning a labeled hypergraph from a given family of hypergraphs using shortest path (SP) queries. An SP query specifies two vertices and asks for their distance in the target hypergraph. For various classes H of hypertrees, we present bounds on the number of queries required to learn an unknown hypertree from H. Matching upper and lower asymptotic bounds are presented for learning hyperpaths and hyperstars. Moreover, inspired by Hein’s algorithm for learning evolutionary trees with bounded vertex degrees, we develop an efficient algorithm for learning any hypertree. The query complexity of the algorithm is bounded from above by a function linear in the edge degree. As part of this research, we also introduce the notion of bag graph, which is a new way to generalize a graph, and provide an efficient algorithm for learning certain bag trees with SP queries. The query complexity of the algorithm for learning bag trees is bounded from above by a function linear in the bag degree. This algorithm allows us to carry over ideas from Hein’s algorithm for learning trees to our task of learning hypertrees.
Open Access
Victim blaming in the courtroom: The influence of lawyer gender and style on juror decision-making
(Faculty of Graduate Studies and Research, University of Regina, 2024-08) MacDonald, Katie Lynne; Yamamoto, Susan; Tottenham, Laurie Sykes; Sangster, Sarah
Despite the present Canadian laws meant to protect victims of sexual assault during the trial process, it is common for defence lawyers to employ stereotypes against the victim (a process known as “whacking”; Tanovich, 2015). It is unclear whether the gender of the defence lawyer is a determining factor in the influence of such stereotypes. Only a limited number of studies have examined the effects of lawyer gender, which yielded conflicting findings (Levi et al., 2022; Villemur & Hyde, 1983). Moreover, the previous studies did not explore whether the lawyers’ cross-examination style or the juror’s level of sexism factor into their verdict choice. This thesis extended previous literature by examining the potential impact of defence lawyer gender, cross-examination style, and jurors’ benevolent sexist attitudes on the outcomes of sexual assault trials and lawyer perceptions. A community sample (N = 212) of jury-eligible Canadians were recruited to read a mock sexual assault trial transcript. The defence lawyer’s gender (woman/man) and cross-examination content (whacking/no whacking) were manipulated. Following the trial transcript, participants delivered an individual verdict and completed measures of ambivalent sexism, rape myth acceptance, and perceived lawyer capability. Three-way interactions were not observed between lawyer gender, cross-examination style, and juror sexism on the verdict outcome or lawyer capability. However, benevolent sexism did directly predict perceptions of the defence lawyer, and the whacking manipulation indirectly affected the verdict outcome via mock jurors’ perceptions of the victim’s culpability. Of most interest, implementing the whacking tactic increased the defence lawyer’s chance at obtaining a not-guilty verdict if the lawyer and the juror were men. Keywords: Juror-decision making, lawyer gender, benevolent sexism, rape myth acceptance, sexual assault trials, victim blaming
Open Access
Beta-delayed proton emission of magnesium-20 and the RCMP silicon detector array
(Faculty of Graduate Studies and Research, University of Regina, 2024-09) Liu, Jizhong; Grinyer, Gwen; Berg, Marcella; Mobed, Nader
In 2011, experiment e09024 was performed in National Superconducting Cyclotron Laboratory(NSCl) located at Michigan State University from Michigan state. The goal was to investigate delayed particle emission for isotopes near proton drip line. The main secondary beam was ²²Si while other exotic beam such as ²⁰Mg,²²Al,²³Si was also produced. The delayed particle emission from ²⁰Mg is of particular interest in this thesis and has been studied in details. In 2018, Dr.Gwen Grinyer's group at University of Regina started constructing a Silicon Detector Array named Regina Cube for Multiple Particle(RCMP) used for studying delayed particles at proton drop line with high resolution and high solid angle coverage. The detector is designed to be placed inside GRIFFIN chamber located at TRIUMF cyclotron facility. GRIFFIN chamber designed by GRIFFIN collaboration consists of 16 High Purity Germanium detectors with 8 fast timing LaBr3 used for studying gamma rays. It is a high effociency detector chamber with BGO shielding for Compton suppression. The combination of the two could provide more detailed study of nuclear structure for isotopes near proton drip line. The detector has been deployed in 2024 and a new experiment on ²⁰Mg S2232 is being scheduled during 2024 summer. In this thesis, I will be presenting analysis of ²⁰Mg from experiment e09024 with development and testing of RCMP detector array and experiment S2232. Key words: Proton Drip line,Beta-delayed, NSCL, TRIUMF, RCMP, GRIFFIN
Open Access
Progressive partition-based granular computing and complexity measures
(Faculty of Graduate Studies and Research, University of Regina, 2024-09) Li, Qiaoyi; Yao, Yiyu; Mouhoub, Malek
Granular computing has received much interest over the past few decades due to its effectiveness and practicality in managing complexity. While it is intuitively believed that complexities in granular computing are linked to granularities, there do not exist any studies to show they have a direct connection. This suggests the need to investigate complexity from a different perspective. Simon’s concept of nearly decomposable systems, which describes complexity from a hierarchical perspective, aligns closely with the hierarchical nature of granular structures. Thus, granular structures can provide a foundation for exploring complexities in granular computing. This study investigates the complexity of the progressive partition-based model of granular computing. We formally define the progressive partitioning tree (PPT), which is the structure used in the progressive partition-based model, and provide a general method that recursively measures the complexity of PPTs. Additionally, we propose a class of interaction-based complexity measures by treating interactions as the source of complexity. These measures can quantitatively explain the complexity differences between structures and the complexity reduction offered by the progressive partition-based model of granular computing.

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