Copyright of Brock Student Theses and Major Research Papers (MRPs)

Students retain the copyright of their theses and major research papers. Under the terms of the “Thesis and Major Research Paper Copyright Licence” students grant Brock University the right to preserve and disseminate theses and major research papers via the Brock University Digital Repository, Library and Archives Canada and in other third party thesis databases.

Sub-communities within this community

Collections in this community

Recent Submissions

  • Weighted Graph Compression using Genetic Algorithms

    Rutkowski, Emilia; Department of Computer Science
    Networks are a great way to present information. It is easy to see how different objects interact with one another, and the nature of their interaction. However, living in the technological era has led to a massive surge in data. Consequently, it is very common for networks/graphs to be large. When graphs get too large, the computational power and time to process these networks gets expensive and inefficient. This is common in areas such as bioinformatics, epidemic contact tracing, social networks, and many others. Graph compression is the process of merging nodes that are highly connected into one super-node, thus shrinking the graph. The goal of graph compression is to merge nodes while mitigating the amount of information lost during the compression process. Unweighted graphs are largely studied in this area. However, in this thesis, we extend the approaches to compress weighted graphs via genetic algorithms and analyse the compression from an epidemic point of view. It is seen that edge weights provide vital information for graph compression. Not only this, but having meaningful edge weights is important as different weights can lead to different results. Moreover, both the original edge weights and adjusted edge weights produce different results when compared to a widely used community detection algorithm, the Louvain Algorithm. However, the different results may be helpful to public health officials. Lastly, the NSGA-II algorithm was implemented. It was found that NSGA-II is more suitable as a pre-processing tool, in order to find a target compression that introduces a comfortable level of distortion, and then using the single-objective genetic algorithm to achieve an improved solution for the target.
  • Advancing a Youth-Centered Pedagogy that Fosters Physical Literacy by Working with Youth and YMCA Recreation Providers

    Petersen, Jennie; Applied Health Sciences Program
    Participation in sport and physical activity declines in children at approximately 11-14 years of age. Efforts to support long-term participation in physical activity have focused on the promotion of physical literacy, which offers a holistic view of the factors affecting youth participation. Limited research has explored pedagogical approaches that can support youth physical literacy and engagement in recreational sport and physical activity contexts. This dissertation investigates pedagogical approaches aimed at supporting youth physical literacy in a YMCA recreation context using action research. An important objective was to support change in YMCA organizational pedagogical practices. Practical implications for the implementation of physical literacy are discussed throughout. Interviews with 10 youth and eight coaches involved in YMCA recreational sport and physical activity programs were conducted in the first study of this dissertation. Factors that supported youth engagement included sense of enjoyment, learning and accomplishment, and comfort with peers in the program. Youth described feeling disengaged when they felt a low sense of autonomy, excluded, or if there was potential for embarrassment. Gender stereotypes were identified as a contributing factor leading to lower levels of participation and engagement in girls. Coaches who had previously taken physical literacy related training perceived improvements in their instructional ability to engage youth. In the second study, 31 youth participated in a series of focus group meetings exploring what approaches to physical literacy resonate amongst youth. During a wrap-up meeting with YMCA stakeholders, youth participants shared their ideas and courses of action. Findings demonstrated that the presence of a caring adult, interacting with peers of a similar age, opportunities to have input and co-create their programs, games-based approaches, and the flexibility of their program structures were important factors for enhancing youth involvement in sport and physical activity. In the last study, a youth-informed recreation instructors training was designed, developed, and co-created with six YMCA stakeholders over the course of seven focus group meetings. A key outcome was the development of a recreation instructor training, called Working ‘with’ Youth in Sport and Physical Activity. Findings provide insight on the challenges that recreation organizations face with implementing physical literacy concepts.
  • The Influence of Occupational Footwear on Slip Responses

    Yuan, Vanessa; Applied Health Sciences Program
    Falls in the workplace most often occur due to slips and unsuitable footwear. While industry standardized occupational footwear (OF) is required for the safety of occupational activities, little is known about how OF influences how individuals respond to an unexpected slip. Therefore, the purpose of this study was to investigate how OF affects balance recovery strategies and slip outcome in response to an unexpected slip during walking. Twenty-five individuals (13 males, 12 females) completed a total of 12 walking trials at a self-selected pace in either barefoot (BF) or while wearing OF. The first five trials consisted of the no-slip condition, where individuals walked over a sheet of high friction aluminum foil. On the sixth trial and without the participant’s knowledge, the aluminum foil was replaced with a low friction hard plastic surface to induce an unexpected slip. The remaining six trials were conducted over the low friction surface while participants were aware of the low friction surface. For each walking trial, ground reaction forces, lower limb electromyography and kinematics were recorded. It was found that when individuals in both groups first experienced the unexpected slip, both groups responded with a macro-slip. However, the slip was less severe in the OF group, with a 13 cm shorter heel slip distance and a 0.6 m/s slower heel slip velocity, compared to the BF group. A less severe slip may have been due to differences found in normal walking, since the OF group applied 23% less shear force and had a 16% smaller co-efficient of friction utilized. Differences in slip severity may have also contributed to the ensuing slip response. The OF group, who experienced a less severe slip, demonstrated 35-49% less muscle activity in the left (slip limb) medial hamstrings and left tibialis anterior as well as 2˚ less plantar-flexion after encountering the slip. The OF group also activated their right (non-slip) tibialis anterior, medial gastrocnemius, and vastus lateralis to a lesser extent, by 66-78%, after the slip onset. Although walking in OF appears to lead to a decreased slip risk and a less severe slip outcome, more research is required to evaluate the effectiveness of these slip recovery responses in reducing workplace falls.
  • The Logo “Visual Thickness Effect”: When and Why It Boosts Brand Evaluation. Does It Relax the Logo Visual Asymmetry Side-effect?

    Eyni, Ardalan; Faculty of Business Programs
    Logos are one of the first elements of brands with which new consumers interact. Thus, the symbolic meanings that a logo implies by its visual characteristics, e.g., circularity vs angularity, symmetry vs asymmetry, etc., can form consumers’ early perception of personality of the associated brand. A considerable body of research studies the key visual elements of logos that influence consumers’ perceptions about the associated brands. The primary aim of this research is to contribute to this body of literature by documenting the logo “Visual Thickness Effect” (VTE) as an understudied but influential visual phenomenon. Using 4685 MTurk participants and 34 fictitious logos, across two pre-studies and five main studies, we find support for the logo Visual Thickness Effect, in that thick logo boosts perception of brand personality, as a result of boosting perception of brand power. Also, the perception of brand power induced by logo thickness is moderated by consumer’s level of perceived power of the self, in that consumers with higher sense of power are less influenced by thickness of logo, as a sign of brand power, when evaluating a brand. Further, the perception of brand power induced by logo thickness is moderated by consumer’s level of visuospatial capacity, meaning that people with higher visuospatial sketchpad are less influenced by thickness of logo, as an extraneous visual stimulus, while evaluating a brand. Also, results suggest that the logo Visual Thickness Effect is at play as long as consumers do not already possess complementary information about the associated brand. Furthermore, we try to contribute to the findings of prior research by suggesting perception of logo familiarity as the underlying mechanism why asymmetric logo attenuates the perception of brands sincerity, competence, and ruggedness. Results show that symmetrical logos can be perceived as more familiar than asymmetrical logos. Findings of this research imply that brands, especially new-to-market brands, might exploit thick logos. This research contributes to the literature for perception of visual elements, logo design, brand evaluation, perception of power, and sensory marketing.
  • More Than a Green Roof: An Analysis of Low Impact Development Policies and Practices

    Anyan, Edward; Environmental Sustainability Research Centre
    While the concept of green infrastructure is becoming increasingly popular, practitioners and institutions that implement it have varying perspectives on its meaning. This case study aimed to understand how a medium-sized municipality defines green infrastructure as a concept and incorporates it into official policies and related development plans to encourage green stormwater management strategies. It further sought to understand how the analyzed policies and related plans stimulate low impact development implementation in response to climate change adaptation efforts. A content analysis of eight official documents was conducted to determine how the City of St. Catharines, Ontario defines green infrastructure and includes it in its policies and plans. NVivo 12 was used to gather the meaning of green infrastructure and related terms qualitatively. The findings discuss how green infrastructure was defined and incorporated, as well as the consistency of its usage and meaning across the sampled official documents.
  • Emerging Market Indexes During the Pandemic Period

    Khan, Md Nafeesur Rahman; Faculty of Business Programs
    The thesis empirically examines and analyzes an unusual episode in the behavior of emerging indexes. Specifically, it investigates the sensitivity of high-frequency five-minute interval index price movements to COVID-19-related news announcements and macroeconomic news announcements during the pandemic. The author hypothesized that COVID-19 infection cases, deaths, vaccination counts, major vaccine development announcements, and government response measures related to COVID significantly impact the emerging equity markets’ returns and volatility, namely Argentine, Brazilian, Chilean, and Mexican equity indexes. They also hypothesized an asymmetric effect of macroeconomic news before and during the pandemic. Findings reveal that pandemic cases, vaccination, and death-related news announcements exhibit a statistically significant effect on intraday volatility but not so much on returns. At the same time, government response measures have a more pronounced and significant effect on return and volatility. Additionally, vaccine research & development and approval news increase intraday volatility. Findings also suggest that very few macroeconomic news indicators exhibit statistically significant asymmetric interaction before and during the pandemic, and fewer US macroeconomic news indicators are significant during the pandemic than before. The results support previous findings that US macroeconomic news announcements significantly impact Canadian and Mexican equity indexes, suggesting a linkage between them with US financial markets.
  • Integrating Behavioral Skills Training within an E-Learning Modality to Train Volunteers Working with Neurodiverse Populations

    Young, Kirsten; Center for Applied Disability Studies
    People supporting neurodiverse populations (often volunteers) must acquire adequate training on instructional strategies to ensure the safety of the people they support and those around them. While behavioral skills training (BST) is an empirically validated training framework, it has some resource constraints such as requiring an experienced trainer. Adapting a BST framework for an interactive mobile application (app) to train volunteers may increase their ability to accurately implement a set of pre-determined target behaviours with fewer resources needed. This evaluation included two studies. In Study 1 the researcher conducted semi-structured interviews with volunteers with experience in an adaptive physical activity program to inform app training content. Experienced volunteers indicated three skills they wanted to receive training on to support neurodiverse people (visual schedules, modeling, and high-probability instructional sequence). In Study 2 a multiple probe design across behaviours was used to assess the efficacy of the app for teaching the three target skills to two novel volunteers. Direct observations were conducted virtually to determine the efficacy of the app for increasing volunteers’ performance accuracy on the pre-determined skills. Both participants demonstrated increased performance accuracy of each target skill following relatively brief interaction with the app. They also reported that they found the app to be acceptable and showed improvement on pre-and post- quizzes after using the app. These results suggest preliminary evidence of the efficacy and acceptability of providing training via an interactive technological platform (using BST) for volunteers working with neurodiverse populations.
  • The Role of CRISPR-Mediated Phage Resistance in the Development of Phage-Based Biocontrol for Erwinia amylovora

    Parcey, Michael; Centre for Biotechnology
    In the post-antibiotic era, resistance in pathogenic bacteria is projected to significantly hinder crop production and become one of the leading causes of death. This has necessitated the development of therapies to address antibiotic resistant microbes and prolong the period for which antibiotics remain a viable treatment option. A prominent alternative technology that has recently re-emerged is the use of bacterial viruses known as phages. Phages selectively lyse their bacterial hosts during the replication process but must avoid phage resistance mechanisms to eliminate a bacterial population. In this dissertation, the impact of phage resistance on biocontrol efficacy is examined using the phytopathogen Erwinia amylovora. The primary source of acquired phage immunity in bacteria is the CRISPR-Cas system. However, the absence of methodologies to study Erwinia phages, and a lack of genomic data for E. amylovora, has previously hindered this avenue of research. Quantitative real time PCR assays were developed to simultaneously monitor both the E. amylovora and phage populations. The individual steps of the phage lytic cycle during infection were characterized by further modification of this methodology. Through this, phage candidates ΦEa46-1-A1 and ΦEa21-4, that previously demonstrated high biocontrol potential, were shown to produce a large number of progenies over a short period of time. A comparative genomic analysis using 127 sequenced isolates of E. amylovora was then completed. This study proposed three primary clades of E. amylovora which infect apples in North America. A novel bioinformatic pipeline was subsequently developed to analyse the CRISPR regions of E. amylovora and the activity of the CRISPR-Cas system was then confirmed. While each clade of E. amylovora exhibited a unique CRISPR arrays, none of the identified CRISPR spacers provided inherent protection against any biocontrol candidate. CRISPR-mediated phage resistance was confirmed in E. amylovora against biocontrol candidate ΦEa21-4 but only in isolates with primed CRISPR-Cas systems. Still, phage resistance to ΦEa21-4 was observed through an unknown resistance mechanism in wild-type isolates. Overall, this work demonstrates new techniques to improve trial outcome prediction and lays the foundation for further investigation into the phage resistance mechanisms of E. amylovora.
  • Enhancing Online Faculty Development Programs During COVID-19 and Beyond: A Multiple Case Study of Faculty Members Teaching Online

    Saddik, Wessam; Department of Graduate and Undergraduate Studies in Education
    This study explored how the development needs of faculty members teaching online can inform professional development (PD) programs in higher education (HE), especially after a year and a half of transition to fully online courses due to the pandemic. The research was conducted in a midsize university in Ontario and utilized a multiple case study approach that examined the cases of four faculty members through an emergent process of in-depth interviews. The main criterion used to select participants was an experience with online teaching of at least 1 year. Data were collected from interview responses as well as from documents representing research studies the faculty members wrote about their teaching experience. Multiple cases were constructed using an inductive coding analysis process, and a cross-case analysis was conducted to identify themes common across the cases. Inductive coding was used to analyze the data. Findings revealed that faculty PD programs should be diversified when it comes to program format, duration, regularity, and topics. Programs differentiated in these ways are essential to accommodate diverse PD needs as well as the different stages of online faculty members’ development of expertise. One-time PD events may not offer the best opportunity to develop faculty members. Informal learning opportunities such as learning communities, research publishing, and mentoring are the most preferred and should be prioritized. HE institutions play an important role in enhancing PD programs either directly through improving program design or indirectly through modifying institutional policies and budgets.
  • Molecular Detection for the Apicomplexan Parasites Cyclospora cayetanensis and Cryptosporidium spp.

    Albano, Alexandria; Applied Health Sciences Program
    Background: Cyclospora cayetanensis and Cryptosporidium spp. are intestinal Apicomplexan parasites that can cause severe diarrheal disease in children and immunocompromised hosts. Diagnostic challenges using routine diagnostic methods lead to an underreporting of these parasites, particularly in resource-limited settings. Establishing affordable molecular detection techniques will allow for the reliable determination of these parasites’ prevalence in those settings. Objective: The overarching objective was to optimize polymerase chain reaction (PCR) protocols to detect the presence of C. cayetanensis and Cryptosporidium spp. in human stool samples. Once optimized, these protocols will be used to undertake epidemiological research in Honduras. Methods: To optimize the C. cayetanensis PCR assay, we utilized a previously identified sample that contained C. cayetanensis oocysts, as confirmed by epifluorescence microscopy and safranin staining. Two additional samples from a Honduran epidemiological study on soil-transmitted helminths (STH) reported positive by the modified Ziehl-Neelsen staining were also used. The PCR protocol comprised the amplification of the 18S rRNA gene. To optimize the Cryptosporidium spp. PCR assay, a first step was to identify positive samples among donated specimens from a Honduran epidemiological study on STH. Initial screening was done with an enzyme immunoassay (copro-antigen ELISA). The PCR protocol comprised the amplification of the COWP gene and subsequent species identification using RFLP. Results: The C. cayetanensis and Cryptosporidium spp. PCR assays were both optimized. The C. cayetanensis PCR assay revealed one positive sample of the three tested. The positive sample using epifluorescence microscopy and safranin staining showed the corresponding 18S rRNA gene band at ~501 bp. As for the Cryptosporidium PCR assay, only one was PCR-positive out of 4 ELISA-positive samples. RFLP analysis of this sample revealed a possible mixed infection by both C. hominis and C. parvum. Conclusions: Both protocols can now be used to analyze human stool samples in future collaborative epidemiological research with our partners in Honduras.
  • Multi-guide Particle Swarm Optimisation for Dynamic Multi-objective Optimisation Problems

    Jocko, Pawel; Department of Computer Science
    This study investigates the suitability of, and adapts, the multi-guide particle swarm optimisation (MGPSO) algorithm for dynamic multi-objective optimisation problems (DMOPs). The MGPSO is a multi-swarm approach, originally developed for static multi-objective optimisation problems (SMOPs), where each subswarm optimises one of the objectives. It uses a bounded archive that is based on a crowding distance archive implementation. Compared to static optimization problems, DMOPs pose a challenge for meta-heuristics because there is more than one objective to optimise, and the location of the Pareto-optimal set (POS) and the Pareto-optimal front (POF) can change over time. To efficiently track the changing POF in DMOPs using MGPSO, six archive management update approaches, eight archive balance coefficient initialization strategies, and six quantum particle swarm optimisation (QPSO) variants are proposed. To evaluate the adapted MGPSO for DMOPs, a total of twenty-nine well-known benchmark functions and six performance measures were implemented. Three experiments were run against five different environment types with varying temporal and spatial severities. The best strategies from each experiment were then compared with the other dynamic multi-objective optimisation algorithms (DMOAs). An extensive empirical analysis shows that the adapted MGPSO achieves very competitive, and often better, performance compared to existing DMOAs.
  • An Exploration of the Current Orientation Practices for Clinical Instructors at Ontario University Nursing Programs

    Van Roon, Breann; Applied Health Sciences Program
    The Joint Provincial Nursing Committee in Ontario in 2015 set forth recommendations to improve clinical nursing education. This thesis was conducted to explore the current orientation processes for new clinical instructors within nursing programs at Ontario universities. Qualitative methodology, more specifically case study design, was chosen to guide the research process. Eight participants from six universities in Ontario were recruited, using purposeful sampling, and participated in semi-structured interviews. Four themes emerged from the data: (a) the process of orientation starts with the hiring process; (b) training methods and content of orientation programs; (c) completion of the orientation process; (d) clinical instructors as part-time employees. Findings indicated that there is a lack of a standardized orientation process across Ontario, resulting in inconsistencies in how clinical instructors teach across the province. It is recommended that an evidence-informed, standardized orientation model be developed to provide consistency in clinical education across Ontario.
  • Mean Power Frequency of Boys and Men during a Progressive Isometric Contractions Protocol to Exhaustion

    Langille, Jordan; Applied Health Sciences Program
    Background: The mean power frequency (MPF) of an electromyographic (EMG) signal is affected by contraction intensity and muscular fatigue but is also a potential indicator of motor unit (MU) recruitment. Methods: This study is a secondary analysis (Woods et al. 2019) in which participants (17 boys, 20 men) completed a progressive isometric contraction protocol while EMG was recorded from the vastus lateralis (VL), using tripolar surface electrodes. MPF and EMG threshold (EMGTh) were calculated for each completed intensity. The latter reflects the onset of accelerated increased in higher-threshold MU recruitment. Independent t-tests were used to assess differences between groups in demographic variables, mean MPF (MPFmn), peak MPF (MPFPK), force (%1RM) at MPFPK, and MPF range. An ANOVA for repeated measures was used to assess differences between groups in MPF pattern, interpolated over ten stages. A correlation analysis was used to assess the relationship between %1RM at MPFPK and %1RM at EMGTh. Results: Both, MPFmn and MPFPK were higher in the men, but only reached statistical significance when %body fat was used as a covariate in the statistical analysis. 65% of participants displayed an expected (inverted-U shape) MPF pattern. Within this subset, the %1RM at which MPFPK occurred was significantly higher (i.e., occurred later) in the boys compared with the men. Additionally, a moderate correlation was observed between the %1RM at MPFPK and the %1RM at EMGTh (r = 0.51). Discussion: Overall, the findings of the current analysis provide support for the hypothesis of lower type-II MU activation in children. The high variability in MPF patterns may be a result of the interaction between confounding factors that affect MPF (intensity and fatigue). Future research should use an exercise protocol that examines MPF under the influence of each factor separately.
  • Innovation and Stock Returns

    Shahid, Sonal; Faculty of Business Programs
    The main aim of this thesis is to determine the relevance of innovation for the average stock returns, thereby investigating if innovation is one the factors explaining the stock returns. Innovation has been identified as an important determinant of economic growth and has been incorporated in economic growth models. With respect to equity returns, one part of literature identifies innovation as source of increased risk given the uncertainty associated with its outcome while another part of literature finds high innovation to reduce technological risk of a firm. In this thesis, we find that there is a premium to high innovation particularly for small size stocks. The highest innovation stocks earn higher average returns than lowest innovation stocks and this effect is significant and prominent for small size stocks. This persists when innovation is accounted for along with other variables like book to market value, operating profitability and investment. Regressing innovation sorted portfolios against Fama-French 5 factors model generates positive significant alphas for high innovation portfolios, even when controlled for size. Based on this, an innovation factor is constructed that captures the difference between the average return on high and low innovation portfolios. This innovation factor is incorporated in the Fama-French 5 factors model as the sixth factor evaluating if the model better explains the average stock returns. The six factors model incorporating innovation factor is rejected based on the test statistic testing if the alphas produced by the model are jointly equal to zero. However, the six factors model produces lower values of test statistics and alpha based measures used for model comparison, implying an improvement over the existing model.
  • Objects in your rear may be less important than they appear: How objects in candidates’ video interview backgrounds influence interviewers’ perceptions of fit and hiring recommendations.

    Angus-Yamada, Owen; Faculty of Business Programs
    Interviews are widely used by hiring managers to inform their decisions; however, the interview evaluations have been found to be influenced by various factors, including the physical and professional appearance of the candidates. With the growing popularity of video interviews, my research examines how the appearance of video backgrounds, through the presence of personal objects, can influence interviewer judgements. It also adds to the personnel selection literature by testing a theory – the Prototype Match Model – to examine how appearances, more generally influence interviewer judgements. Using an experimental design that controls for the video background and involved 92 undergraduate and graduate students, I found no evidence that the presence of personal objects in the background elicit inferences of personality traits and influence interviewer evaluations. There was, however, some evidence to suggest that a prototype match process occurs in the interview, where the closer candidates match the interviewers’ vision of the ideal employee, the more positive their interview outcomes are.
  • Exploring Fan Experience with Multiple Cases of Relocation and Expansion

    Parent, Brett; Applied Health Sciences Program
    Current literature surrounding sport team relocation and expansion only examines a fan’s experience with one relocation or expansion at one point of time. With relocation and expansion being a commonality in the sports industry, there are many sports fan who have experienced multiple cases of relocations and expansion. Experiencing multiple relocations and expansions may also expose individuals to teams at varying levels of play. In Canada alone, 17 cities have hosted both a hockey team at the professional minor-league and amateur major-junior level at different points in time. To examine this phenomena, 12 individuals from Belleville, Ontario were interviewed, as Belleville has had four cases of relocation and expansion in their surrounding region in the last 40 years. These participants demonstrated four themes that suggest that experiencing multiple relocations and expansions has a lasting impact on their fan behaviour and attitudes. First, participants suggested that geography, distinctiveness, and exposure at a young age acted as a motivation to cheer for a newly established team, while existing team allegiances acted as a barrier. Second, participants discussed the unique consumption strategies they used to maintain an identity with a relocated team, such as following ex-players, recalling memories, and incorporating the relocated team into their present-day activities. Third, participants outlined the different points of attachment they developed with an amateur team versus a minor league team, as well as the points of detachment that they claimed to have with minor league hockey. Lastly, participants suggested that they have experienced six changes in perspectives towards teams, leagues, and hockey.
  • GSK3 signalling in DBA/2J mdx mice: a comparison against the traditional C57BL/10 mdx model and investigation into its pathogenic contribution

    Whitley, Kennedy; Applied Health Sciences Program
    Duchenne muscular dystrophy (DMD) is an X-linked disorder caused by an absence of dystrophin that compromises membrane integrity, ultimately resulting in muscle weakness, wasting and premature death. There is currently no cure for DMD, however, promoting the slow oxidative fibre type and reducing inflammation in muscle has become a viable therapeutic strategy. In this thesis, the role of glycogen synthase kinase 3 (GSK3) in DMD pathology, as it relates to inflammation and muscle fibre type composition, was examined. Specifically, the purpose of this thesis was to first characterize GSK3 signalling in two mdx mouse models of DMD, the traditional C57BL/10 (BL10) mdx mouse and the more severe DBA/2J (D2) mdx mouse model. Next, it was examined whether inhibiting GSK3 with a clinically relevant drug called tideglusib would promote the slow oxidative fibre type, reduce inflammation and ultimately enhance muscle structure and function in the D2 mdx mouse. In the first objective of this thesis, it was found that total GSK3 was significantly higher in extensor digitorum longus (EDL) muscles from D2 mice compared with BL10 mice. Inhibitory serine9 phosphorylation of GSK3 was also significantly lower in D2 mice compared with BL10 mice, suggestive of a strain effect whereby D2 mice had more active GSK3. In the second objective of this thesis, it was found short-term (2-4 weeks) tideglusib treatment (10 mg/kg/day) increased EDL:body mass ratio and reduced serum creatine kinase levels compared with vehicle control. Tideglusib treatment also enhanced muscle function with a significant improvement in hangwire impulse, and EDL specific force production and fatigue resistance. In the EDL muscles, tideglusib treatment reduced total GSK3, a result that was associated with an increase in the proportion of oxidative type I and IIa fibres and elevated utrophin mRNA expression. However, tideglusib treatment did not alter inflammatory cytokine expression of IL-1 and TNF-. Collectively, these results show that GSK3 activation may contribute to dystrophic pathology in the D2 mdx mouse and that short-term tideglusib treatment can inhibit GSK3 in these mice leading to a promotion of the oxidative fibres and an improvement in muscle form and function.
  • Low-Dose Lithium as a Therapy for High-Fat Diet Induced Obesity: A Burning Topic in Metabolic Research and Adipose Tissue Browning

    Ryan, Chantal Rose; Applied Health Sciences Program
    The prevalence of obesity is rising at an alarming rate around the globe. As a way to combat obesity, the activation of white adipose tissue thermogenesis has been a burning topic in metabolic research. Recent findings from our lab demonstrate that this thermogenic program is inhibited by a protein kinase known as glycogen synthase kinase 3-β (GSK3β); and the inhibition of GSK3β provides a mechanism to activate adipose tissue browning. Lithium (Li) is a well-known inhibitor of GSK3β and also a known sensitizer of insulin signalling. Our previous work has demonstrated that low dose lithium inhibits GSK3β and induces adipose browning in healthy male chow-fed mice. The purpose of this thesis was to examine the efficacy of low-dose lithium supplementation to inhibit adipose tissue GSK3β to activate the browning process to overcome the effects of high-fat diet (HFD) induced obesity and insulin resistance. 72 male C57BL/6J mice were divided into three experimental groups: 1) control (CON; n=24), 2) HFD (60% fat; n=24), and 3) HFD supplemented with a low-dose of lithium in their drinking water (10mg/kg body weight/day; HFD+Li; n=24) for 12 weeks. Inguinal white adipose tissue (iWAT), epididymal white adipose tissue (eWAT), and interscapular brown adipose tissue (BAT) were collected and underwent western blot and histological analysis. Lithium supplementation did not blunt the diet induced gain in body mass with the HFD. However, the HFD+Li mice ingested more calories than the HFD mice indicative of decreased metabolic efficiency. Lithium supplementation blunted the initial spike in a glucose tolerance test but exhibited no effects on insulin sensitivity at the whole body or tissue specific level. Lithium supplementation did not blunt the HFD induced reduction in GSK3β inhibition (Ser9) in iWAT, however, in eWAT the HFD+Li mice demonstrated higher GSK3β inhibition. Additionally, mitochondrial markers such as PGC-1α and cytochrome C were higher in HFD+Li eWAT compared to control, with cytochrome C being higher compared to HFD mice. This data provides evidence that low-dose lithium supplementation alone can increase the thermogenic program in visceral WAT depots but may not be robust enough to increase thermogenesis in subcutaneous WAT depots under HFD conditions.
  • Positive Experiences, Dreams, and Expectations of International Master’s Students at a Southern Ontario University: An Appreciative Inquiry

    Ankomah, William Sarfo; Department of Graduate and Undergraduate Studies in Education
    This study used appreciative inquiry (AI) as a methodological and theoretical framework and positive psychology theory to investigate international master’s students’ positive experiences, dreams, and expectations in their programs and institution to inform policies, programs, and practices. Although the literature describes international students’ mixed experiences in Canada, including developing critical thinking skills, making friends with other nationals, culture shock, and financial challenges, previous studies seldom focus on life-affirming conditions that enrich and improve such students’ schooling experiences. The first three stages of AI’s 4-D cycle—discovery, dream, and design—informed the study’s data collection methods (14 semi-structured individual interviews and three focus group discussions) to generate strength-based data for analysis, resulting in five key themes: (a) personal well-being and sense of belonging, (b) instructors’ pedagogical practices, (c) financial constraints and employment opportunities, (d) career development, and (e) policies. Based on its findings, the study makes six recommendations to inform international graduate student policy and practice: (a) allow international master’s students to study with their domestic counterparts, (b) increase international student diversity, (c) regularize socializing events for students and community members, (d) bridge the gap between theory and practice (hands-on experience), (e) work with all stakeholders to make international master’s students’ tuition fees more affordable, and (f) create on- and off-campus employment opportunities. Participants’ first-person accounts emphasize the need to include student voices in their own education and also shift the conversation from a deficit lens to a more positive discourse to balance the narratives around international students’ experiences.
  • Assessing the prevalence of injuries in competitive rowing athletes: the effects of body location, sex, and perceived fatigue

    Johnston, Alexander; Applied Health Sciences Program
    The purpose of this study is to; assess the lifetime prevalence of musculoskeletal injures, based on different anatomical regions, including the perceptions of muscular fatigue as a contributing factor to these injuries in recreational rowing athletes; to assess the relative effect of muscle fatigue on musculoskeletal injury in male and female athletes, respectively; to assess the effect of sex on LBP prevalence and severity in recreational rowing athletes. With this purpose in mind a survey was conducted involving rowing athletes across all ages and sexes. In this survey information on rowing experience, injury history, prevalence of low back pain, subjective level of fatigue at the time of injury, activity at the time of most severe injury, and type of pain with most severe injury. The most severe injury incurred for participants most commonly on a rowing ergometer (n=31), followed by training on the water (sweep n=26, scull n=24), most severe injuries were described as a dull pain (n=77). The most common injury site was the back, which had a significantly higher prevalence than the upper body, lower body and other injury sites. Injury prevalence of the upper body was significantly greater than the lower body and other injury sites, and lower body injury prevalence was significantly greater than the other injury sites. Lastly, Participants perceived that they were significantly more fatigued when a back injury occurred than injuries to any other site. Additionally, Injuries to the lower extremity had a higher perception of fatigue than upper extremity and other injury sites. The current work also suggests that there are no systematic differences in the prevalence of low back pain between male and female rowing athletes, nor in the severity of duration of such pain experienced at the low back or in other more general body regions.

View more