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.

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  • Towards the total synthesis of semi-synthetic opiate species and presilphiperfolan-1-ol.

    Wicks, Christopher; Department of Chemistry
    The synthesis of 10-keto opiates is underscored by the urgent need of novel κ-selective opioid agonists that offer comparable analgesic effects to their alkaloid precursors while limiting the risks of physical dependency. While there have been multiple syntheses of oxycodone reported, there has been only one total synthesis of 10-keto-oxycodone to date. Inspired by previous work from the Fukuyama group we investigated a functional group-based approach to oxycodone and 10-keto-oxycodone highlighted by a key oxidative dearomatization step. Efforts made towards this end with be discussed herein. Presilphiperfolanols constitute a family of sesquiterpenes that can undergo further rearrangement to afford a diverse array of terpenoid skeletons due to the ring strain that is inherent to their carbocyclic framework. This structurally complex family of natural products is unique owing to their highly compact tricyclo[5.3.1.04,11]undecane sesquiterpene skeleton that bears five contiguous stereocenters, two all-carbon quaternary centers, and a tertiary hydroxy group. To date, only three natural presilphiperfolanols have been isolated: presilphiperfolan-1β-ol, presilphiperfolan-8α-ol, and presilphiperfolan-9α-ol. In addition to being important biosynthetic precursors, these natural products have also been found to exhibit antimicrobial activity and insecticidal properties. Of particular interest is presilphiperfolan-1β-ol, which has been previously synthesized by Stoltz in the first asymmetric synthesis of a presilphiperfolanol, and subsequently by Tiefenbacher in a semi-synthesis involving supramolecular catalysis. Unlike the approaches by Stoltz and Tiefenbacher, our group has discovered a highly efficient tandem gold (I) catalyzed 5-exo-dig and formal [4+2] cyclization that affords direct access to this tricyclo[5.3.1.04,11]undecane sesquiterpene skeleton. This method has the added benefit of generating 3 of the 5 requisite stereocenters found within the target in a single transformation. Efforts towards the completion of the total synthesis of presilphiperfolan-1-ol will be discussed herein. Experimental and spectral data are provided for all newly synthesized compounds.
  • The Socio-Legal Regulation of BDSM in Canada

    Adams, Zoe; Department of Sociology
    This research examines Canadian case law and the lived experiences of BDSM practitioners articulated on the blog Reddit, using critical discourse analysis in order to understand: (i) How is BDSM framed in legal discourse? (ii) To what extent do dominant discourses produce a criminalised sexual subjectivity for BDSM practitioners? (iii) What interpretive repertoires do BDSM participants in different social locations (e.g., race, class, gender, disability) employ to describe their experiences negotiating consent? (iv) How might an analysis of people’s perspectives and policy arguments contribute to public and scholarly debates by recognizing the social value of BDSM practice? The findings illustrate several discourses, which are categorised by those found within case law data and Reddit data. The discourses found in case law include: Moral custodianship, deviance as a social contagion, biopolitical sexual regulation, state paternalism, and sexual citizenship. The discourses located within Reddit data include: Social-sexual dynamics and hierarchies, self-empowerment/confidence and self-worth, visibility of kink, consent/choice, pleasure/eroticism in kink, and counter-hegemonic pleasures/identities. The distinctions between discursive categories are often blurred as many adjudications and Reddit posts draw from multiple discursive narratives in the appeal for legal action against BDSM-related activities, and the narratives of personal experiences within BDSM communities. Consent, as a concept and practice, is present in Canadian case law and the narratives of BDSM community members within this study. Particularly, this research investigates the nuances of consent, its fluidity, and what consent means in the language of the law as compared to the practices of consent within BDSM-related encounters. Through the narratives of BDSM community members on Reddit, bloggers voice and resist dominant socio-legal discourses that frame their non-normative sexualities as immoral, deviant, and ultimately, criminal. Giving voice to BDSM practitioners contributes to a greater understanding of consent. The corollary of this research is the possibility of utilising the expert knowledge of BDSM community members in differentiating between consented BDSM play and willful sexual assault.
  • Disparities in Mental Health, Physical Health, and Substance Use Across Sexual Orientations in Adults

    Bellows, Zachary; Applied Health Sciences Program
    Background Studying disparities across sexual orientations is important for the design and implementation of public health interventions to improve health in lesbian, gay, and bisexual (LGB) individuals. While prior studies have shown LGB individuals have elevated risk of poor mental health, poor physical health, and substance use, existing study designs may be improved by using representative samples, wider ranges of health outcomes, heterosexual comparison groups, and disaggregated data. The goal of this study is to provide estimates of multiple health disparities across sexual orientations in Canada based on these principles. Methods Using data from 2009-2014 Canadian Community Health Surveys, a sample of 19,980,000 weighted individuals was created. Outcomes included mental health, physical health, binge drinking, illicit drug use, and cannabis use. The study used cross-tabulations and logistic regression models, stratified by sex, to estimate health disparities across sexual orientations. The design of the study is based on pooled cross-sectional analyses. Ten controls, including year of birth, marital status, and income, were included in the fully-adjusted regression models. Results Among LGB individuals, there was evidence for elevated risk of poor mental health (i.e. gay men, bisexual men, bisexual women), poor physical health (i.e. bisexual men, bisexual women), binge drinking (i.e. lesbians, bisexual women), illicit drug use (i.e. lesbians, bisexual women), and cannabis use (i.e. lesbians, bisexual women) relative to their heterosexual counterparts. Those identifying as 'don’t know' or 'refuse' showed reduced odds of substance use. Bisexual women exhibited highest disparities in health outcomes, e.g. OR=3.3, 95% 2.58 - 4.22 for poor mental health. Trends over time showed worsening mental health among bisexual women (relative to changes in heterosexual women), and decreasing substance use in gay and bisexual men, and lesbians. Conclusion This study highlights health disparities across sexual orientations in Canada, especially bisexual women, calling for targeted interventions (e.g. increased training of service providers in working with bisexual women and community outreach against biphobia). Future research should aim to explore these disparities longitudinally while also including the use of administrative-linked health data to reduce potential bias in self-reported data.
  • The effect of Tweets on Cryptocurrencies around the pandemic period

    Paez Beltran, Mateo; Paez Beltran, Mateo; Faculty of Business Programs
    The link between Twitter and cryptocurrencies has been documented in previous literature. However, not all Twitter accounts disseminate the same information to cryptocurrency market participants. This study investigates verified Twitter users and differences between accounts. We differentiate between individual and institutional Twitter accounts, as well as examine the impact of influential Twitter accounts on Bitcoin and Ethereum. We use a high-frequency dataset of Bitcoin and Ethereum quotes, with tweets related to each cryptocurrency. Our data set is from January 1, 2017, to September 30, 2022, and includes the NBER defined Covid-19 pandemic recession period. Thus, we examine whether the impact of tweets is stable over time and economic periods (recession vs expansion). Our results indicate distinctions in the effects between individual and institutional tweets, aligning with existing literature on incentives, audiences, and expertise. Additionally, the study explores the significance of the number of followers and tweets in both user categories, emphasizing that while the number of followers is important, it alone is insufficient, and the frequency of tweets also plays a vital role. Furthermore, the research highlights the impact of influential Twitter accounts, exemplified by figures like Elon Musk, on Bitcoin and Ethereum. This influence is attributed to factors such as a substantial following, perceived expertise, and active involvement in the cryptocurrency space. Tweets exhibit unstable effects over different economic periods.
  • The song remains the same? Responses to adversity in childhood

    Roters, Jennifer; Department of Psychology
    Childhood adversity, specifically abuse and neglect has several outcomes. Both insecure attachment styles and personality disorder traits (borderline and psychopathic traits) are known responses. This dissertation examined two main objectives. The first, to replicate findings where the relationship between childhood adversity and borderline and separately psychopathic traits were indirect through insecure attachment style. In Study 1, anxious attachment was hypothesized to mediate the relationship between adversity and borderline traits and avoidant attachment was hypothesized to mediate for psychopathic traits. In Studies 2 and 3, utilizing Bayesian methodology, fearful attachment was added to the model and hypothesized to mediate the relationship for Factor 2 psychopathic traits. The second objective was to expand the model to include other potential mechanisms in the relationship between adversity and borderline/psychopathic traits. Specifically, the role of mindfulness was examined. Across 3 separate studies, insecure attachment and lower mindfulness were examined. Overall, the findings for insecure attachment were replicated which was supported by the previous literature. The role of mindfulness was more complicated; however, more support for mindfulness as a mediator was found versus mindfulness as a moderator. Limitations and implications are discussed.
  • A Preclinical Evaluation of the Separate and Combined Effects of Context Fading and an Extinction Cue on Mitigating ABA Renewal

    Silva, Carlos; Center for Applied Disability Studies
    ABA renewal as one type of behavioural relapse occurs when a behaviour successfully reduced in one context re-emerges when a previously experienced context is reintroduced. Due to the undesirable effects of renewal, mitigation strategies have been investigated. “Context fading” is one strategy in which the similarity between an intervention context and the context in which an intervention will be transferred is progressively increased. “Extinction cue” is another strategy and refers to the transfer of stimuli associated with an intervention to the context in which the intervention will be transferred to. In this translational investigation, we assessed the separate and combined effects of both mitigation strategies. Forty university students were divided in four groups and completed a computer task. In Phase 1, clicking in a rectangle during a blue background produced points. In Phase 2, the background changed to yellow, clicking on the rectangle was extinguished and dragging a circle into a dotted circle was reinforced. In Phase 3, the contingencies of Phase 2 remained, however, the background colour reverted to blue (as in Phase 1). The “Control Group” did not receive any mitigation strategy. The “Group Context Fading” was exposed to a gradual change in the background color from yellow to blue during Phase 2. The “Group Extinction Cue” was exposed to a red triangle inside the rectangle during Phase 2, which was transferred to Phase 3. The “Group Combined” received both strategies. Results showed a high degree of renewal in Control group. In contrast, Group Extinction cue produced smaller magnitude renewal. Both Context Fading and Combined groups did not show evidence for renewal. Results are discussed in terms of methodological differences in each strategy and practical recommendations for renewal mitigation in applied settings.
  • Accelerated Ovarian Failure Causes Neuronal Detriments in the Menopausal Transition that are not Recovered by High Intensity Interval Training

    Mohammad, Ahmad; Applied Health Sciences Program
    The impact of menopause on Alzheimer’s disease risk has been widely investigated using the ovariectomy (OVX) mouse model, however, this model does not fully capture the gradual hormone depletion that occurs in humans. The novel vinylcyclohexene diepoxide (VCD) model allows for the study of how different stages in the menopausal transition can impact physiology and the brain. Exercise can be introduced during the transitionary perimenopausal phase to limit the negative effects of the menopausal transition on the brain. This thesis aimed to characterize the cognitive and neuronal effects of the VCD model at different stages of ovarian depletion. We later aimed to determine if a high intensity interval training (HIIT) protocol introduced at the menopausal stage would be able to attenuate the detriments caused by the VCD transition. Mice weighing 20-25 grams were injected with VCD for 15 days (160 mg/kg/d) after the transition began. This transition has four landmarks: 60 days post injection = early perimenopause, 120 days post injection = perimenopause, 137 days post injection = early menopause, and 176 days post injection = menopause. Novel object recognition tests (NORT) were conducted on the mice at each timepoint prior to tissue collection. In the second aim of this thesis, another subset of VCD injected mice were either sedentary or put through a HIIT protocol three times a week starting at the 120-day timepoint. HIIT is frequently used as it is a time efficient modality of exercise and its implementation at the 120-day timepoint allows us to determine if its use can improve the neuronal detriments caused by VCD. NORTs were analyzed through DeepLabCut and the collected tissue was western blotted for neuronal and synaptic markers such as NeuN, SNAP25, PSD95 and BDNF. Mice that received VCD had lower discrimination index (%) on the NORT alongside lower SNAP25 and NeuN. Mice that received VCD in combination with exercise had no improvements in cognition, however, they had lower activity of AD hallmarks.
  • Market Reactions to Dual-class Share Creation and Unification: Evidence from Canada

    Rabbi, Md Ata-e; Faculty of Business Programs
    This study examines the short-term market reactions to the creation of dual-class shares and the unification of dual-class shares in Canada from 1980 to2022. Specifically, we analyze abnormal returns, trading volume, liquidity, and institutional ownership changes surrounding these two events. We use the event study methodology to conduct abnormal return analysis on three event days: The Announcement Day (AD), the Approval Day (ApD), and the Effective Day (ED). For our creation sample, we observe the market reaction on all three days and abnormal returns of more than 5% associated with the Announcement Day. For our unification sample, we find a significant abnormal gain of nearly 4% on the Announcement Day. We also observe that trading volume activity increases significantly around both the creation and unification of dual-class shares. Consistent with previous literature, we find that stocks that adopt the dual-class share structure experience a significant decline in liquidity. Cross-sectional regression analysis suggests that positive abnormal returns of dual-class share creation can be explained by the firm’s arrangement of financing or prospect of financing, whereas positive abnormal returns of unification are associated with changes in institutional ownership. Overall, our analyses suggest strong market reactions and changes in important aspects, such as liquidity of firms, to both events.
  • The Effect of PPARβ/δ Activation on Soleus Contractile and Metabolic Function in the Rodent Model of Barth Syndrome

    Andonovski, Martin; Applied Health Sciences Program
    Barth syndrome is a rare and incurable X-linked genetic disease that impairs the production of tafazzin (Taz) protein. Taz catalyzes the transacylation reaction of monolysocardiolipin (MLCL) in the final step of cardiolipin (CL) remodeling to produce biologically relevant tetralinolylcardiolipin (TLCL). CL is an integral phospholipid that is responsible for maintaining mitochondrial form and function. Mutations to the gene that encodes for Taz (TAZ) result in missing or decreased Taz enzymatic activity which lowers the quantity and quality of CL. This leads to mitochondrial dysfunction which produces the hallmark symptoms of Barth syndrome, namely cardiomyopathy, neutropenia (low white blood cells), and exercise intolerance stemming from skeletal muscle weakness. We have recently demonstrated that 8 weeks of supplemental linoleic acid treatment improves rates of contraction and relaxation of soleus in a rodent model of Barth syndrome, the Taz knockdown (KD) mouse. Interestingly, supplemental linoleic acid did not impact CL content or side chain composition. Thus, the mechanism underlying the improvements in contractile function are currently unknown, however, we hypothesize that these improvements may be a result of peroxisome proliferator-activated receptor (PPAR) β/δ activation via supplemental linoleic acid. PPARβ/δ is a transcriptional regulator that, when activated, increases mitochondrial biogenesis and oxidative capacity. Previous research has demonstrated that the activation of PPARβ/δ improves skeletal muscle function in wildtype mice (Chen et al., 2015; Narkar et al., 2008; Y.-X. Wang et al., 2004). Given that PPARβ/δ can be activated by free fatty acids, it is plausible that the improvements to contractile kinetics may be mediated through PPARβ/δ activation by linoleic acid. Thus, the purpose of this project is to investigate the role of PPARβ/δ in improving contractile kinetics in TazKD mice through increased mitochondrial biogenesis and improved oxidative metabolism.
  • Understanding Grade 4-8 Teachers’ Instructional Practices and Beliefs as a Function of Transdisciplinary Coaching in STEM-Language Literacy

    Poltl, Heidi-Ann; Department of Graduate and Undergraduate Studies in Education
    Changes in STEM education in Ontario have resulted in the need for teachers to have professional development and coaching support to introduce a cross-curricular, transdisciplinary instructional approach while honouring teachers’ knowledge, attitudes, and instructional methods. This study sought to introduce Grade 48 teachers to transdisciplinary STEM and language literacy through a five-session coaching partnership with the Principal Student Investigator. Participating teachers and students solved real-world problems using a transdisciplinary rather than typical single-subject instructional delivery. The study adopted a generic descriptive qualitative approach (Elliot & Timulak, 2021) to investigate Grade 48 teachers’ practices and beliefs. Four types of data—pre-questionnaires, interviews, researcher reflections, and fieldnotes—were coded to highlight recurring concepts and descriptive words and expressions. Three meaningful themes and sub-themes were identified to respond to the research question. Findings indicated that changes to teacher instructional practices were possible from starting with structured practices, shifting to inquiry-based, student-driven learning, seeing increasing student motivation and problem-solving and identifying the need for more coaching time. Teachers also saw the benefits of learning coding alongside students and how to implement cross-curricular assessment. Teacher beliefs varied with regards to conceptions of teaching language literacy in STEM; their initial apprehensions shifted to realizations, reservations about accountability related to transdisciplinary learning were expressed, and the positive outcomes of transdisciplinary learning impact on students was witnessed. A productive working relationship was established between the coach and teachers. The teachers expressed that the coach was flexible and open, met the teachers where they were at, listened to their needs, and adhered to the gradual release of responsibility to extend the teachers to their next level of instructional acumen. The study identified how teachers’ practices and beliefs might change when provided with coaching support through professional learning (PL) sessions focused on transdisciplinary approaches to STEM-Language Literacy education. Implications for practice include coaching support for teachers to evolve from single-subject teaching to adopting STEM-Language Literacy with the transdisciplinary approach. Implications for theory suggest that scaffolding teachers through the PL experience with STEM-Language Literacy is consistent with the experiential learning theory (Dewey, 1938).
  • Embedding a Culture of Research in Canadian Community Hospitals

    Rego, Kian; Applied Health Sciences Program
    This study aims to understand how research culture is experienced and shaped in Canadian community hospitals to provide strategies for strengthening community hospital research culture. This qualitative interpretive study employed Schein’s Model of Organizational Culture as a theoretical framework to identify the underlying components of research culture. Data was collected via semi-structured interviews and analyzed using reflexive thematic analysis. The final sample included 38 participants, representing 20 different community hospitals across 6 provinces. As community hospital research programs advanced, participants described a shift in research culture based on three key themes: Awareness and Engagement, Understanding the ‘Why’ and Leadership Support and Organizational Commitment. Aligning with each theme, recommended strategies to achieve an embedded culture of research involve six categories: communications; relationship building; mentorship, training and education opportunities; selecting locally relevant studies; system-level support; and ‘top-down’ versus ‘bottom-up’ approaches. These findings illustrate how research culture is experienced in community hospitals and offers targeted strategies for strengthening community hospital research culture at various levels of experience. Overall, strengthening community hospital research culture is necessary for improving Canadian health system research capacity.
  • A Dire Request: The Effects of Public Outreach on the Professionalization of Conservation in the United States

    Stiver, Carrie; Interdisciplinary Humanities Program
    This dissertation examines public representations of modern scientific art conservation to determine their effect on the field’s professionalization efforts, on public understanding of conservation and museums, and how these effects impacted the development of conservation as a profession and a practice in the United States. The conservation field has long struggled to achieve professional status in American society. Since the mid-twentieth century, conservators have argued that the key to alleviating the ongoing challenges of a sparse job market, poor pay, inadequate support, and a lack of respect from art and museum colleagues, lay in a collective effort to engage in more, and better quality, public outreach. However, this mandate is seldom, if ever, contextualized through examination of how new outreach relates to almost a century of similar efforts. I examine three conservation-focused museum exhibits: Technical Exhibit at Harvard University’s Fogg Art Museum (1936), Take Care at the Brooklyn Museum (1954), and the Lunder Conservation Center at the Smithsonian American Art Museum and National Portrait Gallery (2006-present). While most previous studies of the history of conservation focus on straightforward documentation, my research utilizes co-methodologies of professionalism studies and visual rhetorical analysis to examine conservation as a case study of professionalization and as an active agent in the development of the American public’s relationship to museums. In finding that conservation exhibits are not only ineffective in advancing the field’s professional goals but also actively harm communities by reinforcing the closed system of the modern heterotopic museum, I complicate the ethical grounding of concepts like professionalism and public outreach. Though my final case studies— representations of conservation on the internet— continue to replicate the ineffective visual rhetorical model I identify in museum exhibits, I argue that digital communication, especially social media, has dismantled many of the structures that contributed to the inadequacy of this model and presents an opportunity to build something new. I suggest the path forward that offers the best opportunity for achieving both adequate support for conservation and the field’s highest moral and emancipatory potential lies in abandoning public outreach altogether in favor of adopting a strategy of activism.
  • Synthesis and Reactivity of Diimino-N-Heterocyclic Carbene Supported Tetrylones

    Segizbayev, Medet; Department of Chemistry
    The work described in this thesis is focused on the preparation of a series of novel tetrylones stabilized by diimino-N-heterocyclic carbene followed by studies on their reactivity. In the pursuit of dimNHC-supported stannylone III-6, attempts to isolate free dimNHC ligand IV-19 before its reaction with a tin reagent proved challenging. Conventional deprotonation of imidazolium salt III-7 led to undesired rearrangement product III-10. Facing difficulties in isolating free dimNHC III-8, alternative routes were explored. An effective solution involved using bis(trimethylsilyl)amido chlorotin(II), SnCl[N(SiMe3)2], which generated dimNHC ligand III-8 in-situ. This process simultaneously incorporated the (Sn+-Cl) fragment at the central carbene position, forming cationic stannylene III-14. The subsequent reduction of III-14 with excess potassium graphite resulted in the desired stannylone III-6. The reactivity studies of dimNHC-supported germylone IV-6 were expanded. Germylone IV-6 reacts with azides N3R (R=SiMe3 or p-tolyl) to furnish the first examples of germanium π-complexes IV-10 and IV-11. Reaction of IV-10 with tetrachloro-o-benzoquinone results in the net transfer of a germanium atom and formation of the free diimino-guanidine ligand IV-13. Germylone IV-6 reacts with B(C6F5)3 to give the zwitterionic borate V-7. This compound can be converted into the hydroborate V-8 and further into germylene-borane V-4. Compound V-4 is a Ge/B analogue of Stephan’s FLP parent P/B compound (C6H2Me3)2P-C6F4-B(C6F5)2 but unlike the latter cannot split dihydrogen. Moreover, attempts to prepare a Ge/B analogue of the zwitterion (C6H2Me3)2HP-C6F4-BH(C6F5)2 by protonation of borate V-8 resulted in immediate elimination of H2. A synthetic approach for dimNHC-supported silylone VI-9 involved utilizing the adduct of dimNHC with ZnCl2 VI-11. The adduct VI-11 was prepared by trapping the in-situ formed dimNHC IV-19 with a Lewis acid (ZnCl2). Subsequent exchange between the dimNHC →ZnCl2 adduct VI-11 and the IPr→SiCl2 silylene VI-12 resulted in the formation of the novel dimNHC-supported silylene VI-13. Finally, VI-13 was successfully reduced to yield the desired dimNHC-supported silylone VI-9. Later, we found that dimNHC IV-19 could be directly prepared from imidazolium salt VI-10 by deprotonation with IPr, serving as a Lewis acid-free base. IV-19 is the first isolable diimino carbene. Upon heating IV-19 in toluene, it cleanly converted to the aromatic C-C bond activation product IV-17. With dimNHC IV-19, we established an alternative synthetic route to silylone VI-9 using ligand IV-19 and HSiCl3 as starting reagents.
  • Dwelling in the In-Between: A Self Study of Moving into a Classroom with Unconventional Learners

    Petrachenko, Julian; Applied Health Sciences Program
    The impetus for this research project stems from an enduring commitment to comprehend, enhance, and innovate pedagogical principles underpinning my teaching practices. Experiencing a transition from preparing teachers to work more expressively in movement settings with neurodiverse youth to directly working with neurodiverse adults in a non-movement-based college setting marked a pivotal moment. Recognizing this novel shift in teaching contexts, an inherent need arose for a naturalistic, flexible, and emergent approach to delve deeper into my evolving teaching practice. In employing a Self-Study approach, I followed LaBoskey's (2004) recommended features of establishing an improvement-aimed, self-focused, self-initiated, interactive, and reflective/reflexive research design, where the study employed qualitative data characterized by thickness and richness, fostering questioning and wonderment. The analysis embraced an inductive approach, generating detailed descriptions and narratives by engaging with critical friends, journals, notes, recordings, and continuous reflective writing and self-questioning. Three overarching thematic statements emerged from this immersive analysis: How did I not see that coming/who will it be today; Teaching is hard; The many faces of anxiety. These encapsulated the essence of my evolving teaching practice. Composite narratives were constructed, highlighting trajectories and storytelling arcs that illuminated turning points and critical incidents within each thematic statement. This research endeavor sought to contribute valuable insights into the emergent pedagogical practices when practitioners transition to the college educational sector as contractual faculty and work with a range of complex and unconventional student learners.
  • Effects of Space Restrictions and Mouse Locations on Upper Extremity Kinematics and Muscle Activity during Computer Tasks

    Lang, Cameron; Applied Health Sciences Program
    People spend an average of 37.5 hours/week on their computers, totalling 1800 hours annually (Noack-Cooper, K. L. et al., 2009). Spending >4 hours daily on a computer demonstrates increased MSD risk, such as carpal tunnel syndrome (Ardahan, M., & Simsek, H., 2016; Manktelow, R. T. et al., 2004). Work-from-home scenarios can lead to make-shift workstations, with space restrictions. The purpose of this work was to quantify upper extremity muscle activity and posture during computer tasks, when people are exposed to restricted environments. 18 healthy university-aged participants (8 Male, 10 Female) were recruited. Participants were outfitted with surface electromyography on 16 muscles of the trunk/right upper extremity, and 13 reflective motion capture markers. Two mouse-based tasks were completed using AimLab: 1) a point-and-click task, and 2) a mouse tracing task. Tasks were completed in four common mouse locations in both restricted and unrestricted boundaries. Supraspinatus, upper trapezius, and middle trapezius demonstrated significant increases in muscle activity between both tasks. Right middle (SUPR: 64.1 ± 17.2 %MVE; UPTR: 3.5 ± 0.8 %MVE; MTRP: 12.9 ± 4.4 %MVE), and front keyboard (SUPR: 71.5 ± 19.6 %MVE; UPTR: 3.5 ± 0.7 %MVE; MTRP: 16.0 ± 5.3 %MVE) locations produced the greatest amount of muscle activity in both conditions. Restricted conditions across locations increased joint angles across the shoulder, elbow, and wrist joints. Lateral and deep mouse locations created increased shoulder extension and abduction across both conditions. Participant accuracy was greater in the restricted conditions (PC: 96 ± 5.3%; Track: 84.9 ± 10.7%) compared to unrestricted (PC: 95.4 ± 5.8%; Track: 81.4 ± 8.9%). Increases in muscle activity were found across all locations and conditions for the shoulders and upper back, with the restricted condition demonstrating the greatest increase in activity. This could suggest that increased discomfort and musculoskeletal complaints are probable when working in a restricted environment for extended periods of time. Utilizing the front edge of the desk as a mouse location decreased muscle activity, which may provide rest of relief from muscle overuse.
  • Relationships Between Key Performance Indicators Across Four Swimming Strokes and by Distances in Competitive Swimmers

    Bozyigit, Gokhan; Applied Health Sciences Program
    Key performance indicators (KPIs) are skill-based metrics, used by coaches and athletes to adjust technique and develop race strategies. The purpose of the study was to investigate the effect of key performance indicators (KPIs), such as stroke rate (SR;#/s), stroke count (SC;#), stroke length (SL;m) and kick frequency (KF;#/s) on total swim time (s), across four swimming strokes (butterfly, backstroke, breaststroke, freestyle) of the same swim distance, and within a swimming stroke between swim distances (50m and 100 m). Varsity-caliber competitive swimmers (n=12 males; 19yrs1.4) were recruited. Anthropometric measures including height (m), seated height (m), weight (kg), wingspan (m), hand length (m) and leg length (m) were recorded. Shoulder and ankle range of motion (ROM) measurements and a Y-balance test (YBT) were conducted to profile upper and lower limb mobility. Athletes completed four swim sessions; each session consisted of a standardized warm up, 50m kick, 50m pull, 50m swim and 100m swim distances per swimming stroke. Swimming KPIs and total swim time (s) were collected by a portable Triton 2 device (TritonWear, ON, Canada). A GoPro Hero 8 device (GoPro, California, USA) collected underwater video to facilitate calculating KF (#/s). Descriptives were calculated for all variables across all four swimming strokes and two swim distances. Pearson product-moment correlations revealed significant relationships between select anthropometrics and ROM and performance times (p<0.005), suggesting that both anthropometric and ROM measures have the potential to influence swim performance times. A series of repeated-measure ANOVAs with Greenhouse-Geisser corrections revealed significant differences in select KPIs [SR (#/s), SC (#), SL (m) and KF (#/s)] across the four swimming strokes and between 50m and 100m swim distances within a swimming stroke (p<0.05), suggesting that both swimming strokes and swim distances may utilize different KPI related strategies. A multiple regression analyses was conducted to identify the contribution of pull time (s) versus kick time (s) to total swim time (s) within 50m swim distance and each swimming stroke. Percent contributions were calculated and revealed differences by each stroke. Data-driven metrics obtained during swim performances facilitated a better understanding of the relationships between KPIs, anthropometrics, ROM, and YBT measures. Furthermore, metrics provided support to adjust select KPIs relative to an athlete’s anthropometrics. These sport specific skill-based metrics can empower coaches and athletes to use KPIs to optimize athlete potential and target performance goals.
  • Tracking nuclear generating station emissions and fossil fuel contributions using tree rings in southern Ontario, Canada

    Martin, Danielle S.; Department of Biological Sciences
    Changing atmospheric concentrations of stable (12C, 13C) and radioactive (14C) isotopes of carbon are an important indicator of the Anthropocene. Carbon from anthropogenic sources can be released to the atmosphere as radiocarbon (14C) from nuclear power and above-ground nuclear weapons testing. Carbon-12 and carbon-13 (12,13C) are derived from fossil fuel combustion in the urban, industrial, and transportation sectors. In Ontario (Canada), ~half of the province’s power generation is derived from three nuclear generating stations (NGS), including Bruce Nuclear Generating Station (BNGS), one of the world’s largest NGS. Thus, understanding the contributions of NGS emissions and fossil fuel use in urban, industrial, and transportation sectors is essential for developing accurate atmospheric carbon inventories in southern Ontario. This study analyzes tree-ring Δ14C (the amount of 14C in a particular sample) as a proxy for atmospheric Δ14C by isolating tree-ring alpha cellulose and using accelerator mass spectrometry (AMS). Results indicate that Δ14C tree-ring signatures from white spruce (Picea glauca) and blue spruce (Picea pungens) can track 14C-enrichment from NGS 14C emissions when comparing peaks in tree-ring Δ14C offset data and 14C emissions during the trees’ growing season. Tree-ring Δ14C signatures are also observed in Canada’s largest urban centre the City of Toronto, which is nearby to Pickering Nuclear Generating Station (PNGS). Conversely, Toronto also experiences fossil fuel contributions and thus is susceptible to the Suess Effect. We observe fossil fuel-derived 12,13C from urban activities via tree-ring Δ14C-depletion. Peaks were also observed in the tree-ring Δ14C offset and PNGS 14C emissions. To determine 14C-enrichment or -depletion, sites are compared to a regional clean-air site (Egbert, Ontario, Canada) and northern hemisphere atmospheric background sites (Northern Hemisphere Zone 1; Jungfraujoch, Switzerland). Tree growing season and meteorology analyses strengthen the validity of this study’s results. Similar Δ14C levels from white spruce tree rings and an Environment and Climate Change Canada (ECCC) air sampler (ρ = 0.9273) were also observed. Thus, tree-ring Δ14C signatures can be used to measure local influences from anthropogenic sources of NGS 14C emissions and fossil fuel contributions to help build an atmospheric carbon inventory.
  • Carnosic acid against insulin resistance and obesity. Investigating its effects on adipocytes.

    Vlavcheski, Filip; Applied Health Sciences Program
    Adipose tissue plays a crucial role in regulating metabolic homeostasis, and its dysfunction in obesity leads to insulin resistance and type 2 diabetes (T2D). White adipose tissue (WAT) primarily stores energy as lipids while brown adipose tissue (BAT) regulates thermogenesis by dissipating energy in a form of heat. The process of browning involves transdifferention of WAT into brown-like or beige adipocytes, which exhibit the same functional properties as BAT. Browning of WAT is an attractive approach against obesity and insulin resistance. In addition, evidence indicate that activation of the energy sensor AMP-activated protein kinase (AMPK) could counteract insulin resistance. In recent years, chemicals found in plants/herbs have attracted attention for their use as nutraceuticals for preventing and treating insulin resistance and obesity. For example, metformin derived from French Lilac (Syringa vulgaris), has been an established medication in the management of diabetes and hyperglycemia. However, metformin is associated with adverse side effects thereby prompting the search for alternative plant-derived chemicals that may be useful for obesity and diabetes treatment. Rosemary is an evergreen shrub indigenous to the Mediterranean region, which contains various polyphenols. One of the most abundant polyphenols in rosemary is carnosic acid, a compound exhibiting potent antioxidant, antiinflammatory, anticancer, and anti-hyperglycemic properties. Furthermore, based on the limited evidence available, it appears as though carnosic acid may have anti-obesity and antidiabetic potential, but more work needs to be done, and particularly examine its effects on adipocytes. The present studies aim to examine the effects of carnosic acid (CA) on adipocyte browning, on palmitate-induced adipocyte insulin resistance and investigate the role of AMPK. In the first study, it was found that the palmitate-induced insulin resistance was prevented in the presence of CA and the palmitate-induced increase in the activation of mTOR, its downstream target p70S6K, JNK, ERK and Ser307 phosphorylation of IRS-1 were completely blocked while the insulin-stimulated glucose uptake and Akt phosphorylation was restored. In the second study, we show that CA reduced lipid accumulation and increased the expression of browning protein markers (UCP-1, PGC-1α, PRDM16, TFAM) and mitochondrial biogenesis in an AMPK-dependent manner in 3T3- L1 white adipocytes. Conclusion: These studies demonstrate that CA has a pronounced potential in 1) attenuating the palmitate-induced insulin resistance in adipocytes and 2) stimulating browning of white adipocytes in an AMPK-dependent mechanism. Future animal and human studies are required to examine the effects of CA in vivo.
  • The Behaviour and Ecology of Mosquito Vectors

    Benton, Nicholas; Department of Biological Sciences
    Mosquitoes continue to vector pathogens to humans around the world. Research into the unique behaviour and ecology of vector species enables new avenues of control to be developed. I examined two mosquito vector species. The first, Coquillettidia perturbans (Walker, 1856), has been incriminated as a competent vector of eastern equine encephalitis virus (EEEV) in North America. The behaviour and ecology of Cq. perturbans is poorly studied due to how difficult it is to study the immature stages. I attempted to collect and rear Cq. perturbans to establish a laboratory colony. A multi-generational colony was not successful in part to high mortality rates in the 1st instar and pupal stage as well as a suspected obligatory diapause in later larval instars. Despite this, it was possible to artificially blood-feed and have them oviposit viable egg rafts, which hatched and developed into 4th instar larvae. Larvae and pupae collected from the field were also able to successfully pupate and emerge into adult mosquitoes. Other aspects: such as oviposition site preference, oviposition rate, hatch rate, and immature morphology were also documented. The second species studied, was Culex pipiens Linnaeus, which is known to be a competent vector of West Nile virus (WNV). Cx. pipiens is considered ornithophilic (bird-feeding) but is believed to switch to mammal blood-meals in the late-summer to early-fall in northern regions. I tested a protocol that could be used for determining the host preference of Cx. pipiens in a laboratory setting. The protocol involves creating an environment that limits distractions to feeding and positional bias while giving equal opportunity to choose between two different blood-meals. A PCR assay for testing the blood meal contents of blood-fed mosquitoes was also developed. When tested with bird blood vs. mammal blood, the laboratory colony of Cx. pipiens fed on bird blood ~60% of the time. The number of detections for each blood-meal in a cage raised questions about factors such as bias within the Cx. pipiens colony itself, highlighting a need to take behavioural factors into account when performing laboratory host preference experiments.
  • Moving through the system: The ruling relations of migration, mobility, and childhood disability

    Atwal, Abneet; Department of Child and Youth Studies
    This thesis is about institutional interactions of young disabled children and families who have migrated or have travelled to access services. Through an institutional ethnography, I seek to understand these families’ everyday activities and to make the invisible work of these families visible, and ultimately to interrogate the systems connected to childhood disability and different forms of human movement. For this dissertation, I examined longitudinal data from the Inclusive Early Childhood Service System Project (IECSS; 2021). The IECSS project is an institutional ethnography, a methodology originally developed by the Canadian sociologist and feminist studies scholar, Dorothy Smith (2006). The central problematic of interest for this dissertation was the intersection of childhood disability and human movement in the form of transnational migration, internal migration, and travelling to access services. Through this institutional ethnography, I entered into the everyday experiences of disabled children and their families through the standpoint of the IECSS family informants from across Canada. An analysis of the institutional maps, interview transcripts, and attribute tables led to six (6) key findings: (1) Migration and travelling: What is the context of human movement and childhood disability?; (2) People move, texts stay still; (3) Duplication and replication of services across different communities; (4) Formal and informal support networks: making it work when you’re mobile; (5) The importance of gaining perceived and official citizenship status and; (6) Restarting the process: The added work on families and disabled children. The findings of this study are significant for research, policy, and practice in the area of early childhood, disability, and human movement.

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