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


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  • Novel ways to measure future-oriented cognition: Using parent-report measures and open-ended responses to explore young children’s future thinking development

    Mazachowsky, Tessa; Department of Psychology
    Future-oriented cognition encompasses a set of key abilities that children must develop for successful functioning in daily life including, saving, prospective memory, episodic foresight, planning, and delay of gratification. These future thinking abilities are supported by memory systems (e.g., semantic, episodic), as well as constructive processes, self-projection, and executive functions. Research primarily measures young children’s future-oriented abilities through behavioural tasks, which have various limitations and may not engage future thinking. The current studies introduce new methods to overcome some of these limitations: developing a parent-report questionnaire and examining children’s open-ended responses. In Study 1 (N = 101; Mazachowsky & Mahy, 2020), 3-to 7-year-old’s future thinking was examined to establish the psychometric properties of a new parent-report measure, The Children’s Future Thinking Questionnaire (CFTQ). The CFTQ detected development of children’s future thinking and is a reliable and valid measure. Study 2 (N = 48; Mazachowsky et al., 2020) examined 3-to 5-year-old children’s episodic foresight using a novel, open-ended version of the Picture-book task. Results showed that children were able to generate items for future use and were more successful with age. Children’s explanations for their generated items were typically present-focused and included both episodic and semantic details. Expanding on Study 2, Study 3 (N = 158; Mazachowsky et al., revisions requested) explored 3-to 5-year-old’s explanations for their item choices on two episodic foresight tasks to determine the degree to which these tasks engaged children’s episodic and future-oriented processes. Children provided more future-oriented explanations on the Picture-book task compared to the Spoon task, but episodicity did not differ between tasks. Further, children’s Picture-book task explanations included more first-person personal pronouns compared to the Spoon task, but explanations did not differ in other pronoun use. Together, these studies show that use of a parent-report measure and examination of children’s open-ended responses offer unique insight into the development of young children’s future thinking and engagement in future-oriented processes.
  • Do we become more honest as we age? A multi-methodological approach to studying dishonesty across adulthood

    O'Connor, Alison; Department of Psychology
    Being dishonest with others is a common social behaviour, and it has been proposed that dishonesty increases throughout childhood, peaks in adolescence, and gradually declines across adulthood (i.e., an aging-honesty-effect among older adults). Yet, very little research has comprehensively explored how dishonesty is used and evaluated in later life. Using a multi-methodological approach, the primary goals of my dissertation were to examine if this aging-honesty-effect replicated across methodologies and social contexts and to provide a deeper understanding of the deceptive profiles of older adults to uncover what they lie about, who they lie to, and how they morally evaluate lies. In Study 1, I measured younger and older adults’ willingness to cheat in a spontaneous deceptive paradigm and personality traits of honesty-humility. In Study 2, younger and older adults completed an experience sampling study where they recorded their daily lies for a 7-day period. In Study 3, younger and older adults morally evaluated truths and lies, and participants were recruited in Canada, Singapore, and China to examine if age differences were culturally dependent. Results supported the proposed aging-honesty-effect where older adults were less likely to cheat in a task when given the opportunity (Study 1), they scored higher in the honesty-humility personality trait (Study 1), and they told fewer lies across a 7-day period (Study 2) compared to younger adults. Extending these results beyond lie frequency, Study 2 provided insight into the ways in which younger and older adults use lies in their natural social lives, uncovering that this aging-honesty-effect can vary depending on the type and topic of the lie and the relationship between the liar and the lie recipient. Finally, Study 3 found that not only are older adults more honest themselves, but they evaluate blunt or immodest honesty more favorably and good-intentioned lies less favorably than younger adults, and these effects persisted beyond a Western cultural context. These results provide the foundation for understanding older adults’ use and evaluation of dishonesty and can contribute to constructing a lifespan model of dishonesty from childhood through to old age.
  • Problematic Parents: An Efficacy Analysis of Code of Conduct Policies in Ontario Minor Hockey Associations

    Heipel, Zach; Applied Health Sciences Program
    Minor hockey in Canada holds significant historical and cultural importance. Many children in Canada aspire to become professional hockey players and many parents dream of their child succeeding in the sport at the highest levels. This perceived importance runs the risk of creating a hypercompetitive environment with overinvolved parents that can adversely affect multiple minor hockey stakeholders, such as young athletes, coaches, referees, administrators, and other parents. Existing research has examined violations from parents in various youth sport settings and a lack of institutional policies to inform, monitor, and discipline parents who violate behavioural expectations. Many studies have recommended the inclusion of parental education tools and association disciplinary procedures, but current literature lacks a fundamental understanding of current behaviour policies and their effectiveness. This study examines the contents of code of conduct policies in Ontario minor hockey associations, the behaviour expectations of parents, the effectiveness of code of conduct policies, the various violations that parents commit, and potential recommendations to improve parental behaviour. Employing constructivist epistemology and qualitative research design, this study used interpretive phenomenology and thematic analysis to analyze two types of data: 58 existing code of conduct documents, and 21 semi-structured interviews with minor hockey rep coaches and administrators. This analysis revealed that while many Ontario minor hockey associations have some form of conduct policy in place, content and implementation varies significantly between associations. Furthermore, while participants perceived that parental behaviour appears to be improving in recent years, misconduct incidents still commonly occur with significant negative consequences to various minor hockey stakeholders. Participants identified many strategies to better prevent and respond to parental misconduct in minor hockey are identified and examined, making this study useful to minor hockey associations in developing better policies and procedures to effectively deal with parental misconduct incidents.
  • Climate Discourse Among Canadian NGOs: Ecological Modernization, Civic Environmentalism, and Climate Justice

    Spiegel, Kate; Department of Sociology
    This research examines the websites of twenty-three Canadian NGOs using critical discourse analysis to understand: (i) What climate change discourses are dominant among Canadian NGOs? (ii) What are the goals and strategies being promoted through these discourses? (iii) How are climate issues being framed by these organizations? (iv) Who do NGOs see as the primary agents and mechanisms of change in addressing climate change? The findings illustrate three main discourses--ecological modernization, civic environmentalism, and climate justice--though the distinctions between discursive categories are often blurred as many organizations draw from multiple discursive narratives in their appeals for climate action. Ecological modernization discourse underpins much of the framing of climate change as a threat to the Canadian economy and the benefits of transitioning to a zero-carbon economy through market interventions and green innovation. Equally represented is a Canadian stream of civic environmentalist discourse. Civic environmentalism has a strong presence in how many NGOs attribute the climate crisis to an imbalance in decision-making power between elites and the rest of Canada where the solution is then to restore democracy in political institutions. Climate justice was least represented but offers a more critical understanding of the nature of the climate crisis and emphasizes the need for a broad-based movement that unifies the fights for social, economic, and ecological justice.
  • AN EXAMINATION OF NOTCH SIGNALLING IN THE REGENERATING SPINAL CORD OF THE AXOLOTL, Ambystoma mexicanum: ESTABLISHMENT AND CHARACTERIZATION OF AN AXOLOTL OPTOGENETIC CONSTRUCT FOR UPREGULATION OF NOTCH1 SIGNALLING IN VIVO.

    Lee, Jacob; Department of Biological Sciences
    The Notch signalling pathway is a juxtacrine signalling pathway conserved across vertebrate and invertebrate species and is known to be a potent regulator of progenitor cell fate decisions during nervous system development. The dysregulation of the Notch pathway has been implicated in the establishment of an anti-neurogenic environment following spinal cord injury in mammals that ultimately prevents functional recovery. In regeneration-competent species, where both neurons and glia are produced by resident progenitor cells in response to trauma, Notch appears to be regulated differently. In the regeneration-competent axolotl, very little is known regarding the role of the Notch signalling pathway in the establishment of a regeneration permissive environment. Here I report that the axolotl possesses a homolog of the Notch1 receptor and qPCR data indicate that its expression decreases significantly at 7 days post injury in caudal spinal cord tissue. I further report that the Notch downstream target gene, Hes1, is expressed in the spinal cord 3 days following injury and that bath application of the indirect Notch inhibitor, tert-Butyl (S)-{(2S)-2-[2-(3,5 difluorophenyl)acetamido]propanamido} phenylacetate (DAPT), impairs spinal cord regeneration. Finally, I have modified an existing optogenetic plasmid construct that allows for light-dependent temporal and spatial Notch receptor-independent signalling through the axolotl Notch intracellular domain (NICD). In vitro characterization has included the determination of an effective membrane anchor for this construct and the production of an appropriate light-insensitive negative control plasmid. This research has provided evidence for a role of Notch during spinal cord regeneration in the axolotl and provided a unique optogenetic tool to facilitate the determination of the in vivo role that Notch signalling plays during spinal cord regeneration in the axolotl.
  • Dynamic Configuration of Large-Scale Cortical Networks: A Useful Framework for Clarifying the Heterogeneity Found in Attention-Deficit/Hyperactivity Disorder

    Kember, Jonah; Department of Child and Youth Studies
    The heterogeneity of attention-deficit/hyperactivity disorder(ADHD) traits (inattention vs. hyperactivity/impulsivity) complicates diagnosis and intervention. Identifying how the configuration of large-scale functional brain networks during cognitive processing correlate with this heterogeneity could help us understand the neural mechanisms altered across ADHD presentations. Here, we recorded high-density EEG while 62 non-clinical participants (ages 18-24; 32 male) underwent an inhibitory control task (Go/No-Go). Functional EEG networks were created using sensors as nodes and across-trial phase-lag index values as edges. Using cross-validated LASSO regression, we examined whether graph-theory metrics applied to both static networks (averaged across time-windows: -500–0ms, 0–500ms) and dynamic networks (temporally layered with 2ms intervals), were associated with hyperactive/impulsive and inattentive traits. Network configuration during response execution/inhibition was associated with hyperactive/impulsive (mean R2across test sets = .20, SE = .02), but not inattentive traits. Post-stimulus results at higher frequencies (Beta, 14-29Hz; Gamma, 30-90Hz) showed the strongest association with hyperactive/impulsive traits, and predominantly reflected less burst-like integration between modules in oscillatory beta networks during execution, and increased integration/small-worldness in oscillatory gamma networks during inhibition. We interpret the beta network results as reflecting weaker integration between specialized pre-frontal and motor systems during motor response preparation, and the gamma results as reflecting a compensatory mechanism used to integrate processing between less functionally specialized networks. This research demonstrates that the neural network mechanisms underlying response execution/inhibition might be associated with hyperactive/impulsive traits, and that dynamic, task-related changes in EEG functional networks may be useful in disentangling ADHD heterogeneity.
  • Representing Recovery: A discourse analysis of the television shows You, AJ and the Queen, and Mom

    Downton, Zabrina; Social Justice and Equity Studies Program
    This thesis analyses representations of mothers seeking recovery from drug use in the first season of three serial shows available on Netflix: Mom, AJ and the Queen, and You. Prior to the main analysis of these shows, a literature review was conducted resulting in the opportunity to address a lacuna in the literature related to gender-focused studies looking at recovery from addiction. The shows that were chosen all include at least one character who is a mother and begins the process of recovery. These shows possess striking similarities in their portrayals of an abstinence-based approach to addiction recovery as well as intersecting discourses of addicted women as bad mothers who reproduce deviance through their children. A discursive analysis of Mom, AJ and the Queen, and You seeks to understand which discourses of addiction, drug use, gender, motherhood, and deviance are present in these representations and the messages that are communicated to the viewing public. This thesis illustrates that these representations reproduce dominant, gendered discourses which construct drug using women as deviant women and “bad mothers” who produce “bad children”. These representations further reinforce the dominant abstinence-based recovery discourse that creates a dichotomous understanding of addiction and recovery as active use as the problem and total abstinence as the only solution. Despite the presence of some resistance to these discourses, these shows ultimately reproduce stereotypical, and often harmful, gendered discourses of addiction and recovery.
  • The development of sensitivity to threat among children and adolescents

    Heffer, Taylor; Department of Psychology
    Several theories of adolescent brain development suggest that adolescence is a sensitive period of development characterized by the onset of internalizing problems, such as anxiety. Sensitivity to threat, a heightened responsiveness to aversive situations, has been suggested to be a precursor to anxiety, highlighting the importance of understanding sensitivity to threat among children and adolescents. Yet relatively little is known about the development of sensitivity to threat. Further, identifying the neural indicators that are associated with heightened sensitivity to threat would help classify which youth are most at risk for anxiety. The primary goals of my dissertation were: 1) to explore whether adolescents, compared to children, have heightened sensitive to threat, 2) assess which neural indicators are associated with heightened sensitivity to threat, and 3) assess whether individual differences (e.g., in consistency of sensitivity to threat across time and situation) help predict which youth are most at risk for anxiety-related problems. Study 1 of my dissertation examined, with concurrent data, whether adolescents have greater neural sensitivity to negative feedback compared to children. Study 2 examined whether children and adolescents differ in their longitudinal trajectories of sensitivity to threat (e.g., consistency across time). I also was interested in whether these trajectories were associated with frontal asymmetry, a neural indicator associated with avoidance motivations. Study 3 extended the findings from Study 2 to examine consistency across threatening situations. While Studies 1 through 3 investigated whether adolescence is a period of heightened sensitivity to threat, Study 4 of my dissertation used a latent class analysis to investigate whether individual differences in sensitivity to threat, impulsivity, and emotion dysregulation are associated with anxiety and/or risk taking. Results indicated that adolescence (especially when defined by pubertal status), may be a normative period for sensitivity to threat. At the same time, not all youth who are sensitive to threat go on to develop anxiety; thus, it may be that for many adolescents, sensitivity to threat is an adolescent-limited phenomenon, meaning that threat sensitivity may peak in adolescence, but then tapers off into adulthood. Importantly, neural indicators associated with threat sensitivity helped identify which youth may have the highest levels of threat sensitivity. Overall, my dissertation shows that while some level of sensitivity to threat is normative, it is less common for youth to be consistently sensitive to threats and importantly, these youth who are consistently sensitive appear to be most at risk. Taken together, the four studies of my dissertation incorporate EEG, longitudinal designs, multiple indicators of development (age and pubertal status), and self-report data to gain a holistic understanding of sensitivity to threat from childhood to adolescence.
  • What Factors Increase Odds of Long-Stay Delayed Discharge in Alternate Level of Care Patients?

    Carfagnini, Quinten; Applied Health Sciences Program
    Background: Patients no longer requiring the current level of care they are receiving, but continue to be delayed from discharging, are designated as Alternate Level of Care (ALC) patients. These patients add to the continued challenge surrounding hospital overcrowding. We assessed risk factors of long-stay ALC patients; patients who have been delayed more than 30 days. Objective: The primary objective of this study was to determine the factors that increase the odds of long-stay delayed discharge in ALC patients. Methods: We conducted a retrospective cohort study utilizing data from Niagara Health’s WTIS database between September 2014 and September 2019. We compared hospital location, demographic and needs/barriers factors pertaining to regular versus long-stay ALC patients using logistical regression analysis. Results: Of the 16,436 patients, 1,679 (10.2%) were considered long-stay ALC patients. Long-stay ALC patients were more likely to be male (OR=1.22, [1.08-1.38]), be directly admitted as opposed to through the ED (OR=1.30), currently occupy a convalescent care bed (OR=5.52, [1.66-18.37]) or mental health bed (OR=9.75, [2.36-36.17]) and have a discharge destination of an LTC bed (OR=66.39, [26.22-168.09]). Each present barrier increased the odds of becoming long-stay ALC by 44%. Odds were also increased by the presence of a bariatric (OR=6.13, [2.98-12.59]), feeding (OR=6.48, [1.92-21.92]) or infection (isolation) (OR=2.03, [1.49-2.77]) barrier. Conclusions: Long-stay ALC patients were more likely to be directly admitted, males with discharge destinations to LTC and assisted living facilities with the presence of bariatric, feeding and/or isolation requirements.
  • Mad Futures Now: Avant-Garde Dishumanism in the Poetry of Claude Gauvreau, Hannah Weiner, and bill bissett

    McEwan, Andrew; Interdisciplinary Humanities Program
    This interdisciplinary dissertation puts the theories and aesthetics of avant-gardism into conversation with recent theories of mental disability arising from critical disability studies and madness studies. It does so in order to develop a critical approach that both expands literary disability studies' formal criticism, and provokes avant-garde theorization to reconsider some of its founding aestheticization and metaphorization of mental disability. Through a close analysis of the poetry and poetics of three North American avant-garde writers who have documented lived experiences of mental disability and ableist harm, including Claude Gauvreau (1925-1971), Hannah Weiner (1928-1977), and bill bissett (b. 1939), this dissertation analyzes the modes by which mentally disabled avant-garde poets integrated disruptive aesthetics with their lived experience. Through this analysis, this dissertation theorizes avant-garde dishumanist aesthetics and social critique. With critical attention to silenced narratives, a combined avant-garde dishumanism presents a complex temporality that acknowledges incompleteness, messiness, and the shifting critical positions of communicative relation in audiences of the present. Avant-garde dishumanist texts trouble normative and dominant ideologies for the purposes of creating experiences of future modes of relation and communication from located and embodied positions of disability. Avant-garde dishumanism finds form in a poetics of linguistic rupture and creation of a sense of more equitable futurity in poetry that resists, speaks back to, and reframes mental ableism. This dissertation ultimately argues for a literary disability studies approach informed by avant-garde poetics to both address the avant-garde's roots in mental ableism, and deepen disability studies' formal textual analysis.
  • Decolonizing Graduate Education: Considerations for Integration and Internationalization of a Master of Education Program

    Wainaina, Esther; Department of Graduate and Undergraduate Studies in Education
    Abstract The internationalization of graduate education at Western higher education institutions (WHEIs) is seldom offered in programs that segregate international students from domestic students. The Master of Education Internationally educated Students Program (MEd ISP) at Brock University in Ontario, Canada had offered a segregated graduate program prior to the university’s decision to terminate the program and integrate all future international and domestic students in its Master of Education (MEd) program. While current knowledge of internationalization approaches at WHEIs reveals disparities between official discourses for internationalization and international students’ experiences at WHEIs, this study identified a gap in the knowledge of WHEIs’ strategies for transitioning internationalization from segregated to integrated graduate programs. Adopting a decolonial theoretical framework, the study explored dominant, neoliberal, and colonizing approaches to internationalization in the MEd ISP and sought to advocate for decolonizing considerations for future internationalization of the MEd program at Brock University. The study engaged 5 international students and 1 domestic student in a decolonizing phenomenology that utilized qualitative interviews to explore participants’ firsthand accounts of the strengths and weaknesses of the MEd ISP as well as their perceptions of colonizing and decolonizing attributes of internationalization at Brock University. Interestingly, the study found that the most relevant attributes of colonizing educational approaches were perceptions of the superiority of Western knowledge and not the segregationist approach to internationalization as had been anticipated. Rather than offering formulations for decolonizing the internationalization of graduate programs, the study recommends a process of pertinent questioning that problematizes naturalized Western knowledge through epistemic and ontological pluralization. Further, the study offers initial questions that can be advanced through an iterative interaction of neoliberal, critical, and decolonizing considerations for internationalization of graduate programs at WHEIs. The narrowed scope of the study’s pool of participants contributed a significant limitation to the generalizability of the study. Future studies on internationalization approaches at WHEIs may be inspired to build on the study’s findings to include insights from graduate program administrators and instructors.
  • Nurturing Empathy through Critical Media Literacy and Design Thinking: Partnering Pedagogy to Build Community

    McKinney-Lepp, Melissa; Department of Graduate and Undergraduate Studies in Education
    What counts in critical literacy education today and for learners’ futures? The neoliberal agenda in Canada prioritizes standardization, efficiency, and results- based performance. The social isolation and unrest of the global pandemic are reflected in media headlines and images. This thesis considers narrow views of success in light of critical educational practices that nurture competencies such as critical empathy, collaboration, and communication. This arts-informed multimodal research contemplates how educators can begin addressing what pedagogies work and are important for learners right now. This action research and thesis is framed by design thinking (Ask, Imagine, Design, Build, Evaluate, Refine and Share). Research examined experiences created in a primary classroom where pedagogies were designed to nurture critical empathy (CE) by utilizing design thinking (DT) and critical media literacy (CML). Students worked for a six-month period on an inquiry into family cultures and traditions, which included photographing an important family object, editing, and manipulating these photos (their own and their peers’) and sharing them with audiences. The photographic processes and pedagogies build on Wendy Ewald’s Literacy through Photography work. Data included photographs, journaling, and audio and video recordings were analyzed using my adaptation of Suchar’s (1997) framework. Findings indicated that CE could be nurtured through intentional experiences utilizing DT and CML, reaching both participants and a wider audience who interacted with student work. Specifically, CE was nurtured when students worked towards common goals through opportunities that built upon collaboration, communication, and problem solving over time. CE was nurtured when students had opportunities to become experts, take risks, practice being leaders, and make decisions in a safe and supportive environment. Lastly, CE was nurtured when students had opportunities to build relationships with their peers and consider multiple points of view. Limitations included separating teacher-learner from teacher-researcher roles, and restrictions put into place due to the global pandemic. This research examines and illustrates an alternative to performance-based “best practice” teaching. Utilizing critical literacy, multimodal, photographic pedagogies employed through design thinking, an environment was created where each student could be successful, and competencies were valued over standardized results.
  • The temporal relationship between cardiolipin biosynthesis and remodeling enzymes and cardiolipin content during unloading atrophy in mouse soleus

    Elkes, Mario; Applied Health Sciences Program
    Skeletal muscle is a heterogeneous tissue that consists of individual fibers that differ in contractile and metabolic properties. Skeletal muscle is also dynamic in its ability to adapt to external stimuli through changes in cell size, number, and/or fiber type composition, which are matched by mitochondrial content. Mitochondria are central to skeletal muscle adaptations and mitochondrial energetic function is highly dependent on the membrane phospholipid composition, specifically the mitochondrially exclusive cardiolipin (CL). CL biosynthesis results in nascent CL which must be remodeled by tafazzin (Taz) to form the predominant CL species in mammals, tetralinoleoyl cardiolipin (TLCL). Previous research has shown that CL content and 18:2n6 composition decreased and Taz protein content increased in tenotomy-induced atrophied mouse soleus, suggesting the upregulation of Taz may play a role in slowing this process. Thus, the purpose of this thesis was to examine the temporal relationship between enzymes of CL biosynthesis and remodelling and CL content during unload induced atrophy. Fourteen days post tenotomy resulted in reduced expression of phosphatidyl glycerol phosphate synthase (PGS1) and Taz protein, as well as a reduction in CL content. PGS1 appeared to be reduced prior to changes to CL content, while Taz was reduced following changes to CL content, suggesting that CL content is mainly dependant on PGS1, and the reduction in total CL may have reduced the need for Taz. This is the first study to show a temporal relationship between CL, CL biosynthesis and remodeling enzymes during muscle atrophy. Our identification of the CL biosynthesis proteins which are impacted during muscle atrophy resulting in reduced CL content, may pave the path for future treatment strategies to preserve the function of these enzymes during atrophy, and maintain CL content.
  • The individual and combined effects of creatine monohydrate and lithium chloride supplementation on brain creatine uptake in male and female rats.

    Murphy, Jensen; Applied Health Sciences Program
    During ischemia and traumatic brain injuries (TBIs), phosphocreatine (PCr) acts as a temporal energy buffer preventing rapid decreases in intracellular ATP concentrations. Though, the brain has limited stored creatine and it therefore relies heavily on exogenous substrates. Moreover, creatine monohydrate (CrM) supplementation can significantly increase brain total creatine concentration (TCr). Creatine’s ability to enter the brain is dependent on creatine transporters, and limited evidence suggests lithium (Li), through GSK3 inhibition, upregulates this transport. Therefore, the purpose of this research was to investigate the individual and combined influences of in vivo creatine monohydrate and lithium chloride on creatine concentrations in the rat brain. 64 Sprague-Dawley rats (32 males, 32 females), given ad libitum access to a pelleted 14% certified protein rodent maintenance diet, were randomized into four experimental groups: control (CON), creatine (Cr), lithium (Li), and creatine-lithium (Cr-Li). CrM at 5g/L (0.412g/kg/day) and lithium chloride (LiCl) at 0.2g/L (0.018g/kg/day) were supplemented in the reverse osmosis drinking water. Brain [TCr] was greater with LiCl (p=0.0002), irrespective of CrM, and greater with CrM (p<0.0001), irrespective of LiCl. For slc6a8 mRNA expression, there was a trend for increased expression with LiCl (p=0.12). The female Li group also had a trend greater (p=0.06) than the Cr group. Relative daily CrM consumption was higher without LiCl (p<0.0001) and higher in females (p=0.0001). Relative daily LiCl consumption was higher among females than males (p<0.0001). LiCl inhibited GSK3 activity through an increase in pGSK3a, pGSK3b, ratio of pGSK3a:GSK3a, and ratio of pGSK3b:GSK3b and there was a trend for reduced total GSK3 activity (p=0.11) with LiCl. In conclusion, this study demonstrated that CrM and LiCl supplementation alone and in combination similarly increased brain TCr, with no synergistic or additive effects when combined.
  • The Linkage of Yeast Metabolites, Produced Under Hyperosmotic Stress, to Cellular Cofactor Systems During Icewine Fermentation.

    Allie, Robert; Centre for Biotechnology
    Icewine is a dessert wine of critical importance to the Canadian wine industry. The Icewine grapes are frozen on the vine, creating ice crystals, and subsequently concentrating the solutes in the juice. Icewine juice places yeast under increased osmotic stress, resulting in altered metabolism. This includes increased glycerol production, an internal osmolyte, and higher acetic acid production as they are linked to the cytosolic NAD+ and NADP+ cofactor systems. The yeast glycerol transporter Stl1p allows for glycerol uptake, lowering the production of glycerol and therefore acetic acid. Here we compare two Saccharomyces cerevisiae wine yeast strains, K1-V1116 wild type and K1-V1116 Δstl1, with Saccharomyces uvarum CN1, and relate the differences in metabolite production to the cofactor systems. To that end, starter cultures of each strain were established Icewine juice with samples collected at fixed intervals and assayed for acetic acid, glycerol, ethanol, acetaldehyde, sugar, and the NAD+/NADH and NADP+/NADPH cofactor systems. K1-V1116 wild-type, K1-V1116 Δstl1 knockout, and CN1 showed different kinetics of glycerol and acetic acid production. Although glycerol production per unit time did not vary among the three yeast strains, per unit sugar consumed, K1V1116 Δstl1 produced the most glycerol followed by CN1 and then K1-V1116. K1-V1116 Δstl1 was found to produce the highest amount of acetic acid as a function of sugar consumed compared to the wildtype. CN1 produced the lowest amount of acetic acid as a function of sugar despite producing higher glycerol than the K1 V1116 wild-type. While there was no statistical difference in the NAD(H) redox system ratios between the three yeast to account for the differences in glycerol and acetic acid production, S. uvarum CN1 showed statistically lower amounts of oxidized NADP+ to total NADP(H) compared to both of the S. cerevisiae K1 strains. These findings provide further insight about yeast metabolism under hyperosmotic stress.
  • Effects of Image Temperature and Types of Messages on Advertisement and Product evaluations

    Feng, Junhui; Faculty of Business Programs
    This study examined the effects of images and messages in advertisement and product evaluations. The study categorized advertisements into two parts: images (warm and cold imagery) and messages (abstract and concrete messaging). It is expected that an advertisement with warm images and concrete messages, cold images and abstract messages is more effective in stimulating positive advertisement and product evaluations. The study also explored the mediating role of processing fluency toward advertisement and product evaluations. Results suggest that a warm image fits better with abstract messages, a cold image fits better with concrete messages, which could generate more positive advertisement and product evaluations. In addition, the effect of the “fit condition” of image and message on advertisement and product evaluations is mediated by viewers’ advertisement processing fluency.
  • Re-evaluation of analytical chemistry techniques in studying DNA structures

    Vanloon, Jesse; Department of Chemistry
    This work describes the use of analytical chemistry techniques to examine the structural changes that DNA adopts when subjected to a number of external/internal factors. A self-complementary sequence, d(CG)9, and a non-self-complementary sequence (mixed sequence) were used to study the conformational effects displayed by each type of oligonucleotide sequence. The structural changes adopted by DNA was examined using a variety of analytical techniques, such as: nuclear magnetic resonance imaging (NMR), differential scanning calorimetry (DSC), ultra violet visible (UV-Vis) spectroscopy, circular dichroism (CD) spectroscopy, and high-performance liquid chromatography (HPLC). 1) d(CG)9 and a mixed sequence in the B- and Z-DNA conformation was examined by CD and UV-Vis at a concentration of 1mM using a home-made cuvette called a Flexicell with a minimum pathlength of 0.129± 0.015 mm. The CD and UV-Vis spectra’s produced were found to be reliable when compared to commercial cuvettes with a pathlength of 1 cm and sample concentration of 10 µM. 2) d(CG)9 was lyophilized and reconstituted using either water or buffer to determine if d(CG)9 adopts a different structure when reconstituted using different conditions. It was determined that lyophilized d(CG)9 adopts a hairpin conformation when reconstituted with water, and a B-DNA duplex when reconstituted with a buffer containing NaCl. 3) d(CG)9 was thermally denatured using DSC to determine if DSC can be a viable method to study oligonucleotides. It was determined that d(CG)9 undergoes a two-state unfolding pathway. 4) Nuclear Overhauser Effect spectroscopy (NOESY) and correlation spectroscopy (COSY) were used to examine the conformational differences of 2’-deoxyadenosine when incubated in water. From the distance and torsion angle constraints obtained from NOESY and COSY respectively, and from existing crystal structures, it was found the structures that were determined by NMR spectroscopy were misleading because of spectral artifacts. 5) A mixed sequence was treated with organic modifying agents to determine the minimal condition required for DNA denaturation when different modifiers were used. It was determined that urea at a concentration of 8 M and at a pH of 12.5 is sufficient to denature the mixed sequence duplex.
  • Volitional muscle activation and its reliability in boys and men

    Maynard, James; Applied Health Sciences Program
    Background Maximal torque production largely depends on the ability to activate the available motor unit (MU) pool. Using the interpolated twitch technique (ITT), early studies reported lower volitional MU activation (VA) in children compared with adults, while several recent studies suggested no age-related differences. The reliability of VA determination has been studied to a limited extent in adults but has not been examined in children. Purpose To assess age-related VA difference and its reliability in boys and men. Methods Eleven boys (8‒12 years) and 12 men (18‒30 years) completed two identical test sessions (following habituation session) which included 10 x 5-s knee-extension MVCs, with 2-min rest intervals. Each contraction was immediately followed by an evoked twitch (Tc). A superimposed twitch (SiT) was applied only to the last five MVCs each day. Age-related VA differences were determined using a repeated measures ANOVA. ITT reliability (SiT, Tc, VA) was assessed in 7 boys and 12 men, using intraclass correlation coefficients (ICC), derived from a fully nested ANOVA model. Results Maximal knee extension torque was significantly lower in boys compared with men (84.4±18.5 vs. 267.8±67.6 N.m, respectively), even after correcting for body mass (2.3±0.5 vs. 3.3±0.6 N.m.kg-1, respectively). VA was significantly lower in boys than in men (visit 2: 92.6±4.5 vs. 95.2±2.0 %, respectively; visit 3: 93.5±3.4 vs. 96.2±2.8%, respectively, group effect = 0.04), ii with no difference between visits nor group-by-visit interaction. A similar pattern was observed for the SiT and Tc. The ICC for VA was higher in men than in boys (ICC=0.80 vs. 0.33, respectively). In both groups, most of the variance in VA stemmed from inter-trial variability (58.2% and 59.7% of total variance for boys and men, respectively), indicating inconsistency in both groups. In boys, large day-to-day variance (32.5%) indicated poor stability. The SiT reliability was moderate in both groups (ICC=0.69 and 0.47 for boys and men, respectively). The Tc reliability was high for boys and men (r = 0.96 and 0.85, respectively). Conclusions In congruence with early previous findings, boys’ knee extensors VA was lower than that of the men. Contradictory reports of age-related differences in VA in the literature may be due to lack of reliability, and specifically, lack of trial-to-trial consistency using the ITT.
  • COVID-19 news announcements and the foreign exchange markets

    Gholi Panah, Pari; Faculty of Business Programs
    This thesis entails an empirical study investigating the intraday effects of corona-virus pandemic news announcements on FX market price diffusion components, return, and volatility. The study examines explicitly the major foreign exchange market response to the COVID-19 news release, including pandemic figures related to new confirmed cases, number of deaths, progress of vaccine development and administration, government intervention measures to mitigate virus spread, and the World Health Organization senior official speech about pandemic progress. In addition, this paper investigates the context-specific effects of macroeconomic news. In other words, it examines the effects of important macroeconomic news on currency price components prior to and during the pandemic period. The reason behind this is that the literature has reached a clear consensus about macroeconomic news’s significant effects over time. The findings of this research contribute to both the empirical finance literature and the financial industry because they include insights into the behavior of foreign exchange market participants and international finance portfolio managers when analyzing the effects of unprecedented health, social and economic crises. Previous literature shows that the stability of a country’s foreign trade and its external environments impacts the exchange rate return and volatility. COVID-19 made financial markets more volatile as the pandemic increased uncertainty in foreign trade and foreign investment and intensified financial market risks. To have a clear picture of the impact of the COVID-19 pandemic on FX markets, we incorporate all the essential COVID 19 announcements in this study. Our analysis documents that COVID-19 pandemic indicators and government response policies profoundly impact FX market volatility than a return. Also, regarding vaccine development news, there is strong evidence of FX market reaction to phase 3and emergency approval news related to COVID-19 vaccine development news. There is no evidence of market reaction to WHO official speeches about the COVID-19 pandemic in FX markets. The findings reveal that the FX market reacts to fewer macroeconomic news during the COVID-19 pandemic. However, the market reaction to US macroeconomic news is still state-dependent.
  • Fabrication and Characterization of CoFe2O4-BiFeO3 Core Shell Nanocomposite and SrFe(12−2x)CoxRuxO19 Hexaferrites

    Monfared, Sara; Department of Physics
    This thesis consists of three parts. The first section is about CoFe2O4-BiFeO3 core-shell multiferroic nanocomposite synthesized via a two-step wet-chemical process. The presence of both spinel and perovskite constituents as well as the core-shell structure of nanocomposite have been identified using x-ray diffraction and high-resolution transmission electron microscopy, respectively. Low temperature (5 K) magnetic measurement exhibited a significant exchange bias in the core-shell nanocomposite which confirms promising connectivity of the constituents in the interface. An enhancement in magneto-dielectric of the core-shell nanocomposite over the CoFe2O4-BiFeO3 (0-3)-type nanocomposites has been seen. Further study on the magneto-loss demonstrated the contribution of the magneto-electric and Maxwell-Wagner effects in magneto-dielectric of the core-shell nanocomposite. The second part of this thesis has focused on the bulk of SrFe(12−2x)CoxRuxO19 (x = 0, 0.1, 0.2, 0.3, 0.4) which have been synthesized through the solid-state reaction process. DC magnetic measurement at room temperature exhibited a significant reduction in the coercive field of samples as the concentration of dopants increased. Contrary, an increase in the saturation magnetization was observed in the doped samples. Furthermore, a transition from conical to uniaxial anisotropy has been seen for the doped samples above x=0.3. Thin films of SrFe(12−2x)CoxRuxO19 / (111) SrTiO3 fabricated by a pulsed laser deposition technique, have been studied in the last part of this work. High-resolution parallel beam x-ray diffraction results have shown single orientations for all thin films except one. The thickness of thin films has been determined by the x-ray reflectivity measurement. A certain level of mosaicity has been detected in the prepared films using the rocking curve measurement. The strain and the epitaxial growth of thin films have been investigated utilizing the reciprocal space map technique. Finally, in-plane pole figure measurements revealed high textured films with three-fold and six-fold hexagonal symmetry. The formation of a perpendicular anisotropy in Co-Ru doped Sr-M thin films has been detected from room temperature magnetic measurement. The distribution of Co2+ and Ru4+ ions in different interstitial spaces, the thickness of films, and change in the magneto-anisotropy with a concentration of dopants have a significant effect on the magnetic characteristic of thin films.

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