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The economic burden of athletic injuries across 10 years of Canada GamesInjuries in elite sports are responsible for a substantial economic burden on host organizations, requiring informed decisions to ensure that injury treatment is delivered in an efficient manner. However, there is a paucity of economic assessments that have been conducted surrounding elite sport injury events in Canada. Objective: To estimate the direct medical and opportunity costs of treating various injuries by volunteer medical professionals at the Canada Games (CG). Method: A decision tree model (DTM) incorporated parameters on injury treatment lengths as estimated from a Delphi survey, injury surveillance data from past CG competitions (2009-2019), institutional spending derived from the Athlete Medical Program, and fee-for-service rates for medical professionals derived from government reports. Expected costs were calculated using probabilities from logistic regression analyses and reported in Canadian Dollars as of 2023. A one-way deterministic sensitivity analysis was undertaken which varied annual spending by ±10%. Results: There were 15,717 injury events reported during initial and follow-up visits at on-site polyclinics between the 2009 and 2019 CG events (6 competitions). Median estimated treatment lengths during initial visits were highest for patellofemoral pain syndromes (30.0 [IQR = 15.0-33.5] minutes) and were highest during follow-up visits for impingement injuries (25.0 [IQR = 14.0-30.0] minutes). Knee, ankle, lumbar, shoulder/clavicle, and thigh injuries, had a cumulative average expected medical cost of about $103, $113, $383, $417, and $172, respectively, per event. After having incurred a knee injury, the average opportunity cost of being treated by a physician, a combination of athletic therapist/physiotherapist, or a combination of massage therapist/chiropractor, were $17, $184, and $35, respectively. 72% of athletes treated by a physician were referred for follow-up care. Overall, the total expected medical and opportunity cost of athletic injuries in CG per year were $156,620 and $378,574, respectively. Conclusion: This thesis reports on estimated medical and opportunity costs associated with treating various athletic injuries at on-site polyclinics at CG. Findings from our study can inform decision-making in medical management to support treatment protocol reform, while also informing economic evaluations of future CG or other elite sport competitions. More research is needed to estimate the broader health system and out-of-pocket costs of athletic injuries at elite sporting events beyond on-site polyclinics.
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Does physical activity mediate the relationship between loneliness and mental health in Canadian adolescents?Objectives: Loneliness in adolescents has been consistently increasing over the previous two decades, a trend further exacerbated during to the COVID-19 pandemic. This is particularly concerning considering the links between loneliness and poor mental health. This thesis investigated prospective bidirectional relationships between loneliness and mental health outcomes (anxiety and psychological wellbeing), and additionally, aimed to assess the mediating role of physical activity (PA) within these relationships over a one-year period. Methods: This study used linked student-level survey data of 20,532 Canadian adolescents from the 9th (2020-2021) and 10th (2021-2022) years of the COMPASS study. Cross-lagged panel mediation models were used to test bidirectional associations between loneliness, anxiety symptoms, psychological wellbeing, and PA. Bootstrapping was used to detect mediation effects of PA in the relationships. Models were stratified by gender, and controlled for student grade, family affluence, province, ethnicity, and school-level clustering. Results: Gender-diverse/other adolescents reported higher loneliness frequency and anxiety scores, and lower psychological wellbeing, compared to cis-gender adolescents. Bidirectional relationships between loneliness and anxiety, and loneliness and psychological wellbeing were established in the full sample, with associations varying when stratified by gender. PA did not significantly mediate the relationships between loneliness and the mental health outcomes. Conclusions: Loneliness, anxiety, and psychological wellbeing prospectively and bidirectionally predicted each other, which reinforces current literature that supports loneliness as a risk factor for poor mental health outcomes among adolescents. PA did not mediate these relationships, thus future research should explore novel mediators to help explain the underlying mechanisms in the relationship between loneliness and mental health.
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The Influence of a High Fat Diet on Mice with and without Myosin Light Chain Kinase: Implications for Muscle Thermogenesis and ObesityWork performed at the cellular level suggests that skeletal myosin light chain kinase (skMLCK) mediated phosphorylation of myosin participates in the regulation of muscle thermogenesis. The purpose of this study was to investigate the effect of skMLCK ablation, and resultant loss of myosin phosphorylation, on murine physiology and metabolism. To this end, we compared the morphology and metabolic rate of wildtype and skMLCK absent mice (skMLCK-/- ) in response to 10 weeks of high fat feeding. A larger metabolic challenge better tests the hypothesis that the ability to phosphorylate myosin RLC will aid wildtype mice (WT) in counteracting the obesogenic effects of a HFD more effectively than skMLCK-/- mice. Adult mice (8-12 weeks) of both genotypes were housed at 30°C (thermoneutrality) and randomly assigned to either a control or high fat feeding group (n = 8 per genotype, total of 32 mice). All mice were weighed twice weekly while dual-energy X-ray absorptiometry (DXA) was used at baseline and at week 10 to detect changes in fat and fat-free mass. Metabolic measures such as kcal output as well as behavioural measures such as locomotion, fine movement and food intake were assessed biweekly. At the conclusion of the study, all mice were euthanized, and epididymal white adipose tissue, inguinal white adipose tissue and brown adipose tissue were removed and weighed. Based on cellular studies, it was expected that the absence of myosin phosphorylation would render the skMLCK-/- genotype more susceptible to weight gain than the WT genotype. Contrary to our hypothesis, in vitro data did not translate to effects on whole-body metabolism. WT mice were similarly susceptible to the same morphological and metabolic changes as the skMLCK-/- group when exposed to a high fat diet. Both genotypes consumed the same amount, however, the skMLCK-/- mice were less active and yet, both genotypes gained the same amount of weight. This may suggest a compensatory thermogenic pathway may be at play.
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Exploring Teachers' Experiences of Teaching Online During the COVID-19 Pandemic: A Mixed Methods Multi-Phase StudyThis is a mixed methods multi-phase study that measured teachers’ sense of efficacy for teaching online at the initial stages of the COVID-19 pandemic in the spring of 2020. As the pandemic persisted into the 2020-21 school year, the study was expanded to include a second phase that sought to understand teacher efficacy and experience of teaching online one year into the transition to emergency remote online teaching during the pandemic. The aim of this research was to better understand how to best support teachers as they adapted to online teaching and to use the data to build ongoing and professional learning support for effective online teaching. The study examined the impact of prior experience teaching online, experience teaching online during the pandemic, and access to online training on teacher self-efficacy as teachers adapted to online learning in the context of the pandemic. What became clear was that teaching remotely online under emergency measures is different from normal online teaching. The results of the study in the initial phase found correlations between teachers’ sense of efficacy for teaching online with using a learning management system (LMS) before transitioning online. Having had online training and access to virtual tech support were also associated with a higher sense of efficacy. In the second phase, teachers’ collaboration with colleagues to solve issues and learn affected teacher efficacy. The study also found that access to technical and pedagogical support resources impacted teachers’ sense of efficacy and experience teaching online. One outcome of this study is support for the argument distinguishing between emergency remote teaching and learning and online teaching and learning. Further, the findings emerge from this study support recommendations for dedicated teacher professional development that addresses the challenges and opportunities of designing and implementing emergency remote teaching and learning environments.
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Pre-Service Teachers using Social Media: Self-Concept in Online SpacesWith the expansion of personal interactions to online spaces, specifically through social media, individual identity and self-concept development can be subjected to a variety of interactions, experiences, and comparisons. For pre-service teachers (PTs), interactions through social media can be experienced through a personal and professional lens. This research aimed to understand better the relationship between PT self-concept and social media use. A survey design method with Likert scale instruments was used to determine potential correlations between PT self-concept clarity and self-presentation across personal and professional spheres online. Univariate correlational analyses were run between the four Likert scale tools, and results indicated a weak, positive relationship between self-concept clarity and self-presentation. Self-concept differentiation was addressed by analyzing the open-ended questions at the end of the survey, using a thematic qualitative approach. Results of the qualitative analysis suggested that PTs exhibited a high level of self-concept differentiation as they considered the content of what they posted and presented online for both personal and professional accounts, meaning they accurately utilized the desired self-concept traits for the differing environments. The findings showed that PTs’ self-presentation in online spaces often aligned with their understanding of who they are and who they want to be, and they consider a variety of scenarios when presenting themselves online, including future careers, self-image, and the professionalism of teaching. The findings also showed that PTs compare themselves to others within the program, often feeling a sensation of intimidation, competitiveness, and perfectionism. An implication for teacher education is for programs to provide additional support for PTs who struggle to navigate the competitiveness of a professional program, their own professional identity, and the concept of moral and ethical duties within their roles as PTs and future teachers.
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Treating Yourself in a Fairway: Examining the Contribution of Self-Compassion and Well-Being on Performance in a Putting TaskResearchers have advocated for greater insight into the relationship between self-compassion and well-being on performance. Grounded in this understanding, the purpose of this study was to examine the unique and combined contribution of self-compassion and well-being on performance in a putting task. It was hypothesized that self-compassion and well-being would predict performance. Using a cross-sectional design, male golfers (N = 87, Mage = 54.94; SDage = 15.37 years) completed the Self-Compassion Scale - Athlete Version and the Warwick Edinburgh Mental Well-Being Scale immediately prior to a golf putting task. The putting task consisted of 15 consecutive putts from 7 feet on an outdoor practice putting green. The number of putts holed served as an indicator of actual performance. Perceived performance was measured using a self-reported single-item indicator. Participants holed an average of 7.77 (SD = 3.15) putts. Perceived performance was rated as neither good or bad (M = 2.56; SD = 1.00) across the 5-point response scale. Results from the linear regression analyses showed that self-compassion did not significantly predict putts holed (β = -0.171, 95% CI -2.12, 0.23, p = 0.11; ƒ2 = .03) or perceived performance (β = -0.171, 95% CI -2.12, 0.23, p = 0.11; ƒ2 = .04). Similarly, well-being was not predictive of putts holed (β = -0.013, 95% CI -1.38, 1,23, p = 0.91; ƒ2 = .00) or perceived performance (β = -0.157, 95% CI -0.79, 0.12, p = 0.12; ƒ2 = .03). Overall, conclusions from this research offer converging evidence that the psychological resources of self-compassion and well-being do not impact actual or perceived performance in adult male golfers. Greater insight into whether, and if so under what conditions, self-compassion and well-being are associated with performance outcomes in sport warrants additional empirical scrutiny. Funding: Match of Minds.
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Emotions, Emotion Regulation, and Interpersonal Emotion Regulation for Academic Writing: A Collective Case Study with Doctoral StudentsDealing with feedback, managing uncertainty regarding writing expectations, and juggling multiple demands are all part of making progress with academic writing. Emotion regulation can enable an academic writer to manage these emotion-related experiences and contribute to writing productivity. A writing group might be particularly beneficial to provide emotion regulation support from others through interpersonal emotion regulation. The purpose of this research was to understand the emotion experiences of doctoral student writers while engaged in academic writing in a social context, the ways in which graduate students experience emotions related to their academic writing, how interpersonal emotion regulation is enacted in social writing contexts, and which intrapersonal and interpersonal emotion regulation strategies support academic writing productivity. To investigate these experiences, in the current collective case study research, four doctoral student writers were led individually through meme elicitation during an initial interview to explore their previous emotion experiences in academic writing. Subsequent multi-participant writing group sessions were offered online and video recorded to document the ways in which the participants and the group facilitator (the researcher) provided interpersonal emotion regulation in that context. During and after each writing group session, participants were invited to complete a brief questionnaire about their emotions and their experiences in the group. Final individual interviews provided participants the opportunity to recount their emotion experiences while writing in the group context. Findings indicate that these doctoral student writers experienced a wide variety of emotions in relation to their academic writing. Participants reported a desire to feel positive, activating emotions while they were engaged in academic writing. These same emotions, including happiness, contentment, and engagement, for example, were reported when they were most satisfied with their writing progress after a writing group session. These doctoral student writers used a variety of interpersonal emotion regulation techniques to support each other, most frequently empathic concern and validation. Participants found emotions to be an important factor in writing motivation. They reported using strategies such as breaking the task into smaller pieces, working for shorter time periods, and compartmentalizing their tasks when they were feeling unmotivated to write.
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Understanding Transitions for Disabled Students from Secondary to Post-Secondary Education Using Ecological Systems Theory: A Mixed Methods ApproachThis thesis explored the transition planning experiences from secondary to post-secondary education of disabled students. Transition planning is essential for disabled students to access accommodations in higher education (Newman et al., 2016). Recent changes have been proposed by the Government of Ontario Education Technical Sub-committee to help improve transitions for disabled students by working to remove barriers to transition planning (Government of Ontario, 2021). To date, transition planning processes typically follow an individual model (Small et al., 2013). However, this model has yielded limited results in successfully removing barriers. Further research suggests that an ecological systems approach may be more promising for supporting disabled students in their transition planning process (Small et al., 2013). Based on the literature on transition planning and ecological systems theory, this thesis followed a mixed methods explanatory design using initial surveys and follow-up interviews to contextualize students' experiences. Using the Government of Ontario's recommendations, an initial survey was developed and distributed to disabled first and second-year students at Brock University (n=16). Follow-up interviews were also conducted with participants to contextualize their experiences and discuss recommendations (n=4). A descriptive analysis of quantitative survey results as well as a thematic analysis of qualitative survey responses and follow-up interview responses provides understating on barriers students face and how the government of Ontario’s recommendations may reduce these barriers. The findings of this research demonstrate the need for interdependent supports in transition planning for disabled students when transitioning from secondary to post-secondary education.
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THE OPTIMIZATION OF A TIME-RESOLVED, VESICLE-BASED FLUORESCENCE ASSAY FOR THE ACTIVITY OF THE LIPID KINASE PI4K-IIIBETA AND THE EFFECT OF LIPID TRANSFER PROTEINS ON ENZYME ACTIVITYHuman PI4K-IIIβ is an 89 kDa phosphatidylinositol (PI) kinase that phosphorylates its substrate headgroup at position C-4, thus producing PI(4)P. This phosphoinositide is the most abundant in the trans-Golgi network where it is essential for secretory vesicle formation, as well as the precursor for other phosphoinositides that are crucial for intracellular signalling. Among others, phosphoinositide homeostasis in eukaryotic membranes rely on PI kinases and PI transfer proteins (PITPs). In yeast, the PITP Sec14p is known to exchange PI and phosphatidylcholine between lipid bilayers in vitro and proposed to present PI to be phosphorylated by the PI4-kinase Pik1 in a heterotypic ligand exchange fashion. However, the precise mechanism by which this interaction occurs has yet to be elucidated. To explore how and if PITPs and PI4K-IIIβ work as hypothesized, we expressed and purified recombinant human PI4K-IIIβ in Escherichia coli and assayed lipid kinase activity using an optimized real-time, vesicle-based fluorescence assay. After comparing different affinity tags, deletion mutants and expressing cell lines, GST-tagged wild-type PI4K-IIIβ was chosen and expressed in Rosetta 2(DE3) cells with a 2.5-fold increase in the native protein yield when compared to other methods. Proteins were further purified by an addition heat shock protein removal wash. The resulting PI4K-IIIβ displayed activity comparable to the commercially available, insect cell expressed counterpart. Optimization of the activity assay afforded a robust assay that displayed protein concentration dependent response while using unilamellar liposomes as the substrate. Agreeing with previous reports, the activity of PI4K-IIIβ was greatly reduced by wortmannin and increased by Triton X-100. The activity of PI4K-IIIβ was tested in the presence of active human PITPα and PITPβ, as well as yeast Frequenin and Sec14p, but none of them elicited a reproducible enhancement on PI(4)P production by PI4K-IIIβ. A similar pattern was observed with the human PI3-kinase, PIK3C3. Our results demonstrate that a PI presentation model based on heterotypic exchange may not occur in vitro, suggesting either that PITPs’ role in phosphoinositide production could rely uniquely on maintaining sufficient PI pools in the Golgi membrane or that additional protein partners may be required for the regulation of PI4K-IIIβ by PITPs.
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Stress from Academics, Stress from Interpersonal Relationships and Academic Burnout Among Chinese AdolescentsThe current study examined relations between stress and academic burnout, and the moderating role of adaptive academic coping between stress from academics and academic burnout among adolescents. Potential stress leading to academic burnout included stress from academics and stress from interpersonal relationships (stress from teacher, parental, peer relationships). Five-hundred and eighteen students (48.26% male, 14 to 15 years old) from one middle school in China participated in this study. Structural equation modeling indicated that (1) academic burnout was significantly predicted by stress from academics and stress from parental relationships, but was not significantly predicted by stress from teacher and peer relationships, and (2) adaptive academic coping significantly moderated the association between stress from academics and academic burnout, after controlling for the effects of sex, age, socioeconomic status, and grade ranking. This study provided insight into which types of stress perceived by Chinese adolescents (e.g., stress from academics and interpersonal relationships) predicted academic burnout, and how adaptive academic coping might mitigate links between academic stress and academic burnout. Recommendations of the current study are discussed in terms of government, school and teacher, and parental aspects.
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The Effect of Jack Chapters on the Mental Health Help Seeking Attitudes of Canadian Secondary Students in the COMPASS StudyBackground: School-based peer-led mental health literacy (MHL) programs may be effective tools to reduce stigma, and improve MHL and help seeking attitudes in adolescent populations. The objectives of this thesis were to evaluate the effectiveness of Jack Chapters—a school-based peer-led MHL program—on the mental health help seeking attitudes of Canadian secondary students at the (1) school- and (2) student-level in all students, and (3) in students with anxiety and/or depression. Methods: Linked survey data from the COMPASS study collected during the 2017/18 (T1) and 2018/19 (T2) academic years study were used. The total sample included 5808 students at 30 Ontario secondary schools, of which 3194 students had clinically-relevant anxiety and/or depression scores. COMPASS school-level and Jack Chapters data were used to determine the intervention schools (i.e., schools that implemented Jack Chapters at both timepoints). Four control schools were matched per one intervention school based on school size and urbanicity. A t-test was used to compare the difference in help-seeking reluctancy at the school-level by study group and between timepoints. Generalized logistic mixed models were used to determine the effectiveness of the Jack Chapters program on help seeking attitudes at the student-level between timepoints. Results: At the school-level, there was a significantly greater increase in help seeking reluctancy between intervention schools compared to control schools from T1 to T2. In both the total sample and the subsample, there were higher odds of students being reluctant to seek help at T2 if they were reluctant at T1, however, study group was not a significant predictor of this relationship. Having lower family and friend support were associated with an increase in reluctancy at T2 for both the total and subsample populations, and in the total sample, an increase in school connectedness was associated with a decrease in reluctancy at T2. Conclusions: This study adds to the sparse literature on the effectiveness of improving school-based peer-led MHL initiatives on mental health help seeking attitudes among adolescent populations. Despite the strengths of Jack Chapters, our null results indicate that programming can improve. Findings may inform program targeting for specific populations within the school.
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Distributed Supervised Statistical LearningWe live in the era of big data, nowadays, many companies face data of massive size that, in most cases, cannot be stored and processed on a single computer. Often such data has to be distributed over multiple computers which then makes the storage, pre-processing, and data analysis possible in practice. In the age of big data, distributed learning has gained popularity as a method to manage enormous datasets. In this thesis, we focus on distributed supervised statistical learning where sparse linear regression analysis is performed in a distributed framework. These methods are frequently applied in a variety of disciplines tackling large scale datasets analysis, including engineering, economics, and finance. In distributed learning, one key question is, for example, how to efficiently aggregate multiple estimators that are obtained based on data subsets stored on multiple computers. We investigate recent studies on distributed statistical inferences. There have been many efforts to propose efficient ways of aggregating local estimates, most popular methods are discussed in this thesis. Recently, an important question about the number of machines to deploy is addressed for several estimation methods, notable answers to the question are reviewed in this literature. We have considered a specific class of Liu-type shrinkage estimation methods for distributed statistical inference. We also conduct a Monte Carlo simulation study to assess performance of the Liu-type shrinkage estimation methods in a distributed framework.
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Gender matters: Exploring the mental health of youth experiencing homelessness, a qualitative studyIt is well known that gender shapes mental health experiences broadly. Gender adds an additional layer to the already complex experience of being a male, female, or transgender young person who is experiencing homelessness. Yet, research in this area is limited. The purpose of this qualitative, interpretive description study was to understand how gender shapes the mental health of youth who are experiencing homelessness in the Niagara Region of Ontario, Canada. Eleven young people between the ages of 16 and 24 were recruited from a youth shelter and participated in a semi-structured interview. Interviews were audio-recorded and transcribed so that data could be analyzed using thematic analysis and Gender Based Analysis Plus. Findings revealed four contextual factors that appear to influence a young person’s mental health while homeless, but that are experienced differently depending on one’s gender identity. These factors include (1) housing acquisition is challenging, (2) appearances are meaningful, (3) cleanliness and hygiene are expected, and (4) utilizing mental health resources is complicated. Additionally, the many strengths that the youth identified and demonstrated in navigating their circumstances are highlighted in our results. These strengths include (1) exhibiting resilience, (2) expressing the ability to survive, (3) imagining a world that is better, (4) articulating their needs, and (5) drawing on their social connections. The gendered lens that guides this study provides a challenge to the homogenous way that young people experiencing homelessness are often portrayed within the literature. The experiences of young people who live with homelessness cannot simply be addressed within the siloed categories of gender, homelessness, and age. Ensuring that interventions are tailored to meet young people’s specific gendered needs is both a matter of human rights and health equity. Practical implications for service providers are discussed.
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Understanding Explicit and Implicit U SPORTS Brand Associations Among Ontario University Student Sport FansThe purpose of this research was to generate insight to better understand how explicit and implicit associations of the U SPORTS brand affects the brand’s meaning among Ontario university students who identify as sport fans. This research employed an interpretivist research paradigm, as well as a research lens emphasizing Verstehen. Seventeen semi-structured interviews were conducted with university-aged student sport fans. To analyze the data, Tracy’s (2013) typology approach was utilized to create conceptual ‘bins’ for the emergent themes to be placed in. From there, findings were parsed into explicit and implicit associations of the U SPORTS brand and subsequently incorporated into a U SPORTS brand meaning model inspired by Batey (2008) and Chard’s (2013) brand meaning frameworks.
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The Contribution of Male Allyship to the Struggle for Gender Equity in the Workplace: A Study in Experimental SociologyWhile the legal grounds for workplace discrimination in Canada and many other Western capitalist nations have been eliminated, there is still substantial evidence of gender inequality in many workplaces. Whether conscious or unconscious, practices in work settings often create unwelcoming or exclusionary environments for women. This thesis examines the impact of male allyship as a means to mitigate sexism and motivate others to respond to instances of gender bias in the workplace. Specifically, it seeks to determine if acts of allyship by a male colleague of female employees influence the behaviour of other male colleagues in a work setting. Using a vignette study, participants were asked to imagine starting at a new workplace where they were required to attend an orientation. During the orientation, an existing employee told a story about why they enjoyed working at the company. The gender and extent to which the existing employee shared a story involving an act of allyship against sexism were manipulated. Participants were then asked to imagine being employed at the company for several months. Participants were then exposed to an instance of gender bias and were asked how they would respond. It was hypothesized that participants who were exposed to a male employee who demonstrated an act of allyship against sexism would be more likely to report that they would be comfortable responding to an instance of sexism in an active or confrontational manner. It was also hypothesized that this trend would be most evident amongst male participants. Statistical analysis found participants exposed to a prior instance of allyship during the orientation were significantly more likely to think it was effective to confront a perpetrator of sexist comments (Brandon). On a more negative note, this research additionally revealed that male participants who were not exposed to an instance of allyship during the orientation were significantly more likely to support a perpetrator of sexist comments (Brandon). Several other significant findings involving levels of sexism and personality traits were also found. Implications for these findings are discussed.
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On the Effectiveness of Video Prompting with Embedded Safety Checks to Teach Correct Child Passenger Safety Restraint Installation and HarnessingIn North America, motor vehicle collisions are the leading cause of unintended injury-related deaths among children under the age of 14. The primary cause of these deaths is the improper use of child passenger safety restraints (CPSR). Correctly installed CPSRs can decrease the risk of fatal injury by 45% to 95%. To date, no studies have used video prompting with embedded safety check to teach correct CPSR installation and harnessing in the absence of researcher implementation. We used a concurrent multiple baseline across participants design to evaluate the effectiveness of a video-prompting procedure with embedded safety checks to teach four prospective parents and caregivers CPSR installation and harnessing skills. All participants learned to perform these skills and these effects maintained for 4 weeks. Further, this training produced an improvement on all participants’ performance of an untrained installation position, vehicle, and harnessing skill, and these effects largely maintained for 4 weeks.
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Child-Adult Differences in Discrete Motor-Unit Activation: Insights from sEMG DecompositionThe overall purpose of this thesis was to examine age-related differences in the discrete motor-unit (MU) activation of two muscles, differing by size and recruitment strategy (vastus lateralis (VL) and flexor carpi radialis (FCR)) as well as during contractions where torque was developed at low and high rates. These research objectives were assessed within one research project and reported in three studies. Study 1 (Chapter 3) examined differences in muscle performance and discrete MU activation of the VL (large muscle, broad RT range) between boys and men during moderate-intensity isometric contractions. Study 2 (Chapter 4) examined differences in muscle performance and discrete MU activation of the FCR (small muscle, narrow RT range) between boys and men during moderate-intensity isometric contractions. Lastly, study 3 (Chapter 5) examined differences in discrete MU activation between boys and men during moderate-intensity contractions performed at low and high contraction rates in both the VL and FCR. The collective findings of this work indicate that during moderate-intensity isometric contractions, boys activate smaller MUs that have lower MU firing rates (MUFR) compared with men. Although this general trend was observed in both muscles as well as during slow and fast contractions, the specific age-related differences in discrete MU activation patterns varied between muscles. In the VL, men recruited relatively larger high-threshold MUs compared with boys even when accounting for differences in muscle size. Moreover, lower MUFR in boys was present in low- and high-threshold MUs. On the other hand, in the FCR there were no differences in the relative size of high-threshold MUs between groups, but boys demonstrated a narrower recruitment range which may explain why lower MUFR in boys were especially pronounced among high-threshold MUs. Overall, lower MUFRs in boys compared with men can partly explain age-related differences in size-normalized strength. While our findings provide some support for the notion of lower type-II MU activation in children, other emergent differences in MU activation suggest that there are other explanatory factors contributing to differences in muscle performance between children and adults.
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“At Breakfast We Heard Whistles Blowing”: Nationalist Sentiment in St. Catharines 1899-1902Scholarship on Canadian nationalism in the late nineteenth and early twentieth centuries provides a clear but broad examination of predominant types of nationalist thought in Canada at the outbreak of the Boer War (1899-1902). Nationalism was often influenced by regional considerations, religion, ethnic background, education, and gender. However, existing scholarship neglects the ways that nationalist thought manifested in and shaped everyday life of citizens and communities. This thesis explores the intensity and nature of nationalist sentiment in St. Catharines during a brief window in time—1899 to 1902—as seen through the lens of the local media and contemporary sources such as diaries, veterans’ association records, publications, and civic reports. This material reveals that nationalist sentiment, as articulated on a micro level, was nuanced in its promotion of the city as a small but significant node in a broader imperial nation. In St. Catharines, imperial nationalism manifested in ways that privileged an Anglo, white, Protestant, middle- to upper-class audience who enthusiastically participated in the perpetuation of an imperial view of Canada’s role in the world.
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Responding to organizational crisis: The role of crisis communication message framing and communication information processing to protect organizational credibilityThis research studied the impact of communication message framing (rational vs. emotional) and consumer’s information processing system (systematic vs. heuristic) on organizational credibility during a crisis. The different emotions induced by different message framings influences consumers’ information processing and the credibility towards the company differently. It established a fit between rational-systematic and emotional-heuristic suggesting that rational message framing would be more fluently processed under systematic processing and emotional message framing would be more fluently processed under heuristic processing. The research considered the moderating effect of crisis timing strategies and crisis type as well which are considered significant to assess during such setting. Findings propose an effective communication model for developing corporate response strategies during an organizational crisis. The research would add incremental contribution to practitioners in assisting them design the framing of the communication messages based on their customer profiling post a crisis. In terms of theoretical perspective, the study extends the literature of crisis communication by establishing a matching of rational vs. emotional message framing with systematic vs. heuristic information processing respectively.
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Investigating Drill Constraint Kinematics in Male Baseball PitchersPitching requires the development of high forces (Werner et al., 1993; Fleisig et al., 1995) to be generated in short periods of time (Werner et al., 1993; Seroyer et al., 2010). The ecological dynamics approach can be used to enhance these qualities through the use of constraint drills (Wilk et al., 2002; Wilk et al., 2009; Brady et al., 2020; Gray, 2020). In this framework, coaches aim to implement a variety of appropriate constraints to help facilitate an effective search for successful movement solutions (Renshaw et al., 2010). This study aimed to use pitchAITM (Dobos et al., 2022) to 1) determine kinematic differences that pitching constraint drills (e.g. medicine ball shot put drill, pivot pickoff drill, foot-up rocker drill, walk-in drill, towel drill, janitor drill, drop step drill, and long toss) elicit compared to a typical baseball pitch, and 2) determine the effect of experience, fatigue, intensity, height and weight on kinematics. 25 male baseball pitchers with average height (183.16 ± 6.28 cm), weight (87.48 ± 9.38 kg), and pitch velocity (34.57 ± 2.89 m/s) were included in this study. pitchAITM videos of pitches and drills were captured, and demographic information, prior drill experience, pre and post-testing fatigue collected at two different baseball training facilities. Extracted pitchAITM data included five joint angles, four maximum joint angles, five maximum rotational velocities, and nine timing related metrics. Multiple linear fixed effects models revealed a total of 127 unique significant kinematic differences in response variables across all measured pitching constraint drills compared to the pitching delivery. Prior drill experience, fatigue, intensity, height and weight also had significant influence on measured kinematics. This work demonstrates the first collective approach to studying the biomechanics of common constraint drills, in which coaches can refer to when choosing appropriate drills for effective practice design.