Ph.D. Applied Health Sciences
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Item Open Access A Case Study Exploring Mothers' Experiences of Well-being in Prenatal and Postnatal Yoga at a Maternal Wellness Centre using Transformative Service ResearchXing, Trisha; Applied Health Sciences ProgramThe purpose of this case study is to explore experiences of well-being for prenatal and postpartum mothers at a maternal wellness centre in Ontario, Canada. Specifically, I examined the mothers’ experiences in prenatal and postnatal yoga classes (core service) and related wellness services drawing on transformative service research. Through field observations (140 hours over four months) and 33 semi-structured interviews (mothers as well as members of the health-service network), this study provides an in-depth understanding of how experiences of well-being are both co-created and/or co-destructed in prenatal and postnatal yoga, as well as through service experiences at the maternal wellness centre. Using reflexive thematic data analysis, three themes, each with three to five subthemes were developed: a) Centering a Woman’s Body as the Expert; b) Constructing a Meaningful Ambience and Social Connections Co-creates and Co-destructs a Sense of Support and Well-being; and c) “It’s Wellness Capitalism”: Maternal Wellness Is Not Fully Accessible to All Perinatal Women. The analytical observations bring attention to the complexities of offering yoga and maternal wellness services, specifically the ways in which well-being can be co-created, co-destructed and/or inaccessible for perinatal women.Item Embargo Dissecting the role of MAP3Ks TAK1 and ASK1 in IgE-FcERI mediated mast cell exocytosisWatson, Colton J. F.; Applied Health Sciences ProgramMast cells are sentinel immune cells and the main drivers of allergic inflammation. Upon allergen exposure mast cells initiate immediate degranulation in the early-phase of the response, followed by de novo production and secretion of pro-inflammatory mediators in the late-phase. Co-stimulating with allergen and SCF results in the amplification of the pro-inflammatory response launched by allergically-activated mast cells, and a connection between the two signalling pathways is the mitogen activated protein kinase (MAPK) pathway. Therefore, this dissertation includes 3 studies that focussed on MAP3K proteins, TAK1 and ASK1, that are potential nexus points in the signaling mechanisms of the allergic inflammatory response. Our previous work identified TAK1 as a central regulator in co-stimulated mast cells, and study 1 found that TAK1 regulates signaling through both the FcERI and ckit receptor individually as well as supporting that the MAP3K level is an appropriate target for therapeutic development of mast cell stabilizers. Study 2 was carried out to determine if other MAP3Ks, specifically ASK1 also exhibited the regulation observed with TAK1 in allergically-activated mast cells. We found that despite ASK1 sharing the same level in the MAPK cascade, its inhibition did not have as significant an impact in activated mast cells, suggesting that TAK1 is unique in its ability to regulate mast cell function following allergic stimulation. Study 3 was an explorative study to determine how TAK1 is able to exert its regulatory effect on the allergic inflammatory response. We identified a novel interaction between TAK1 and the lipid kinase PIP4K2B. This discovery elucidates the mechanistic placement of TAK1 in mast cells and increases our understanding of the regulation of mast cell inflammatory mechanisms. Taken together, the following research shows that different MAP3Ks exert varying levels of regulatory control in allergically activated mast cells, with TAK1 appearing to be robustly influential, especially compared to ASK1 under the same conditions. Furthermore, we present evidence to support a novel interaction between TAK1 and mechanisms supporting the generation of PIP2, which has the potential to lay the foundation for a new field of study looking into the relationship between the canonical MAPK pathway and lipid metabolism in mast cells.Item Open Access Investigating cross-education in multiple sclerosis following upper limb robotic rehabilitationMannella, Kailynn; Applied Health Sciences ProgramThe overall goal of this thesis was to develop an adaptive rehabilitation technique using a haptic wrist robotic device that would induce the phenomenon of cross-education to improve upper limb function. Following a literature review, Chapter 4 provides a scoping review of existing literature surrounding rehabilitation robots for MS. Chapter 5 reports the development and rationale of the rehabilitative approach, to develop an algorithm that is individualized and adaptive to the user. Once the algorithm was developed, an eight-week intervention for fourteen individuals with MS and eight non-affected adults was conducted. The purpose of the intervention was two-fold and presented in Chapter 6, to improve overall wrist and grip strength (assessed via maximal grip and isometric wrist strength) and Chapter 7, to improve overall motor control (assessed via robotic performance measures). Lastly, in both chapters, cross-over effects of strength and motor control to the untrained limb were evaluated. Results of this eight-week training reported increases in wrist strength for the MS group with an average percent change score across all muscle directions of 62.59% in the trained limb and 53.26% in the untrained limb. The control group also reported an average percent change of 31.31% in strength in the trained limb and 24.26% in the untrained limb. MS participants significantly decreased in tracking and figural error (degree of error) post-intervention suggesting evidence that motor control adaptations are possible following an adaptive and resistive robotic intervention of the upper limb. Following the results of the eight-week intervention, Chapter 9 was to investigate changes in strength and motor control following four-weeks of training in an additional subgroup of participants following the same rehabilitative protocol. Results demonstrate a clinically meaningful improvement in strength of the trained limb, but no significant improvements in figural or tracking error performance – suggestive that robotic rehabilitation of this kind needs to be longer in duration than four-weeks to elicit meaningful adaptations of motor control.Item Open Access Dwelling in the In-Between: A Self Study of Moving into a Classroom with Unconventional LearnersPetrachenko, Julian; Applied Health Sciences ProgramThe 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.Item Open Access Carnosic acid against insulin resistance and obesity. Investigating its effects on adipocytes.Vlavcheski, Filip; Applied Health Sciences ProgramAdipose 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.Item Open Access Athletes vs. Coaches: Perspectives on Social MediaGorrell, Elyse; Applied Health Sciences ProgramThis dissertation’s purpose was to understand the different perceptions of social media in athletes and coaches. Previous research has not given a thorough examination of social media’s effects on coaches, or the consequences of social media for meaningful relations between coach and athlete. Previous literature suggests that not only do athletes not understand the influences or implications of social media, but also that these influences and implications could alter an athlete’s mentality for performance. Previous research also recognized that athletes’ preoccupation with social media is a perceived challenge for coaches. Goffman’s (1959) Presentation of Self in Everyday Life and Sissela Bok’s (1978) Lying functioned as significant theoretical frameworks within this dissertation which was also guided by an existential phenomenological orientation to embodied experience. Methods used included 1) semi-structured interviews with 10 high-performance competitive athletes, from individual sports; 2) content analysis of 13 post submissions by athletes with an athlete reflection; and 3) semi-structured interviews with 6 high-performance competitive coaches. A phenomenological analysis sequence was applied to the data sets, which consisted of parsing the responses to the interview questions into units or phrases of meaning, maintaining horizontalization, and creating a rich description that represented the meanings discerned from the data analysis. Imaginative Free Variation (IFV), guided by the lifeworld existentials of Body, Space, Time and Relation (bstr), was also a strategy used to deepen the examination of themes and summary descriptions. A manifest and latent analysis was utilized on the posts (“phase 2”) to describe the post while suggesting a plausible interpretation that the athlete’s reflection could be compared against. The posts were also used within the coach interviews in order to gain the coaches’ perspectives of the selected posts. The study aimed to bridge the gap in understanding the relation between coaches and athletes and how the effects that social media has on athletes and their performance. The findings suggest that athletes are aware that people are viewing them, and that they are having a difficult time regulating information that they see on social media or how they are using social media. The findings from the “phase 2” analysis suggest that athletes believe that they have insider meaning that the average viewer does not when viewing certain social media posts. These findings also suggest that the coach-athlete relationship runs the risk of becoming less effective, because there is less value given to interactions within the physical environment.Item Open Access On the Physical Demands of Gaming: Quantifying Pain, Muscle Activity, Kinematics, and Performance ChangesForman, Garrick Neville; Applied Health Sciences ProgramWith the rapid growth of both the gaming and esports industries, millions of individuals are now playing games as hobbies and careers. The intense and repetitive nature of gaming can likely lead to significant muscle fatigue and increase an individual’s susceptibility to musculoskeletal injuries and pain. However, the physical demands of gaming have largely been unexplored. The objectives of this thesis fell into three categories. 1) Determine where gamers most commonly experience pain while gaming and whether any demographics or gaming habits can predict pain or discomfort in the upper body (Chapter 3). 2) Determine how muscle fatigue and motor performance of the distal upper limb are impacted by a low-force/high-repetition fatiguing protocol utilizing rapid mouse clicking (Chapter 4) and mouse aiming (Chapter 5). 3) Determine the muscular and postural demands associated with high level, competitive gaming (Chapter 6). In Chapter 3, we identified that the neck, low back, and right arm were the most common locations of gaming-related pain. The high prevalence of gaming-related pain reported confirmed that gaming-related pain is a significant problem which requires further investigation. In Chapters 4 and 5, we found that low-force, high repetition fatigue protocols led to few impairments in motor performance. However, changes in EMG characteristics indicated that the mouse clicking protocol led to fatigue of the wrist flexors while the mouse aiming protocol produced muscle fatigue in the wrist extensors. Finally, in Chapter 6, we found that static loading of the shoulder and forearm musculature exceeded guidelines while playing a competitive PC first-person shooter. Musculature of the upper limb produced sustained high levels of muscle activity with little to no rest, exceeding suggested guidelines based on both magnitude of activity and rest time. This thesis provides some of the first research investigating the physical impact of video games on the upper body. It is also the first work to document the impact of low-force fatiguing protocols on fine motor functioning of the distal upper limb and to quantify the physical demands while playing competitive PC video games.Item Open Access Child-Adult Differences in Discrete Motor-Unit Activation: Insights from sEMG DecompositionWoods, Stacey; Applied Health Sciences ProgramThe 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.Item Open Access Advancements in Trichuris trichiura treatment and diagnosis in children: Assessing high-dose ivermectin, benzimidazoles and diagnostic techniquesMatamoros, Gabriela; Applied Health Sciences ProgramIntroduction Approximately 350 million people are currently infected with Trichuris trichiura. The WHO recommends mass drug administration (MDA) with benzimidazole (BZ) as the main control strategy, however, these drugs have demonstrated a reduced efficacy against T. trichiura infections. The current strategy is, therefore, not suitable for achieving the recently established goal of eliminating STH as a public health problem by 2030. Administration of combination treatment with broad-spectrum anthelminthic drugs such as IVM has been recommended. Objective The aim of this thesis was to investigate the advancements in T. trichiura treatment and diagnosis. First, by conducting an RCT comparing experimental multiple-day, and high-dose IVM drug combinations against ALB monotherapy. Followed by performing a rapid systematic review and meta-analysis to update the current knowledge on the efficacy and safety of IVM administration against trichuriasis in children. Lastly, comparing the performance of RT-qPCR vs. Kato-Katz, to determine their performance in a context of reduced transmission due to treatment intervention. Methods The randomized clinical trial was performed in northern Honduras. Efficacy was measured 14-21 days post-treatment through egg reduction rate (ERR) and cure rate (CR). Safety was evaluated by analyzing the frequency and severity of adverse events. A rapid review of evidence was conducted in 5 databases, to explore the literature results with respect to efficacy and safety of IVM against trichuriasis. Finally, two diagnostic techniques were evaluated to determine their performance after treatment intervention. Results All the experimental arms containing IVM resulted in significantly higher efficacy compared to the standard of treatment. The combination of ALB and high dose IVM demonstrated an excellent safety profile. The rapid systematic review confirmed the superiority of BZ+IVM combination. The two diagnostic techniques resulted in an almost perfect agreement, in a setting decreasing burden. Conclusions These results provide high-quality data contributing to the available body of knowledge related to the challenges faced by the global efforts of STH control, emphasizing in T. trichiura.Item Open Access Investigating the role of Brain Derived Neurotrophic Factor content and signalling on Amyloid Precursor Protein processingBaranowski, Bradley; Applied Health Sciences ProgramAlzheimer’s disease (AD) is a progressive, multifactorial, neurodegenerative disorder putatively linked to aging. The major pathological hallmark of AD is amyloid-β (Aβ) plaques, which is regulated through the activity of beta-site amyloid precursor protein cleaving enzyme 1 (BACE1). As such, understanding BACE1 regulation is crucial in the development of AD preventive strategies. It has been demonstrated that an acute bout of exercise can reduce BACE1 activity and content; however, the mechanism behind this regulation is unknown. One potential mediator of the exercise-induced reductions of BACE1 is brain-derived neurotrophic factor (BDNF). Studies indicate that exercise-induced changes in cognition and neuronal health require the synthesis, release, and binding of BDNF to its receptor. However, in AD, there is a reduction in synaptic plasticity, cognitive function, and BDNF content. The purpose of this thesis was to determine a viable method to elevate BDNF levels to modulate BACE1 activity and to determine the exact mechanisms by which BDNF can elicit this effect. In study 1 we aimed to determine if subcutaneous injections of recombinant BDNF would elicit a similar effect on amyloid precursor protein (APP) processing as observed with exercise. I found that peripheral BDNF injections improved cognitive performance, reduced BACE1 activity in the prefrontal cortex. In study 2, we explored a potential dietary intervention that may influence BDNF levels. Elevated beta-hydroxybutyrate (β-OHB) levels were previously established to elevate BDNF through epigenetic modifications. Therefore, we examined the effect of oral β-OHB supplementation on BDNF and (APP) processing. I determined that β-OHB supplementation was ineffective at elevating BDNF levels and did not improve cognition. However, β-OHB supplementation did reduce BACE1 activity. Finally, despite demonstrating a link between BDNF and BACE1 activity, the exact mechanism connecting them has remained elusive. The final purpose of this thesis was to examine how BDNF can modulate BACE1 activity. I conclude that BDNF appears to be eliciting a regulatory role on BACE1 activity through GSK3β inhibition. Taken together, this thesis highlights potential therapeutic strategies to target BACE1 modulation and elucidates a mechanism by which BDNF acts, thus allowing for more targeted therapeutic approaches in the future.Item Open Access Uncovering the Psychological and Physiological Factors that Influence Performance and Choking Under PressureMarini, Matthew; Applied Health Sciences ProgramResearch suggests that there are more complex psychophysiological influences occurring when an athlete chokes under competitive pressure (Hill et al., 2010; Mesagno et al., 2015). Although the main choking under pressure theories have been researched independently for decades, both Hill et al. (2010) and Lewis and Linder (1997) suggested that these theories are no longer mutually exclusive, with the potential to converge providing insight into the same psychological and physiological factors that influence performance and choking under pressure. Therefore, this dissertation examines the psychological and physiological factors that influence performance and choking under pressure for those who are susceptible to choking, while also exploring different contexts for performers under pressure. This dissertation also investigates how sport psychology interventions such as a pre-performance routine, that integrate breathing, muscle relaxation, attention and self-talk, could help to improve the psychological and physiological factors that influence performance and choking under pressure. In conclusion, all three studies provide insight into the psychological and physiological factors that influences performance and choking under pressure. In particular, the results from study 1 suggested that athletes who are choking susceptible have a lower working memory capacity, and self-confidence, as well as higher cognitive and somatic anxiety than those athletes who are non-choking susceptible. In study 2 results provided insight into how pressure is experienced by athlete and non-athlete performers, and how pressure may be experienced differently between performance contexts. The results from study 3 demonstrated that learning to use a pre-performance routine at the proper time during competition, could help to improve factors contributing to performance under pressure and ideally could help to alleviate a choke.Item Open Access Stepping away from pharmaceutical therapies: Exercise and supplementation with fermented red clover extract as alternative strategies to promote vascular health in postmenopausal womenWickham, Kate A.; Applied Health Sciences ProgramCardiovascular disease is the leading cause of death worldwide. Both aging and menopause, associated with the cessation of endogenous estrogen production, are key factors that contribute to the development of cardiovascular disease in women. Over the last few decades, an interest in alternatives to pharmaceutical interventions for promoting and/or rescuing cardiovascular health in postmenopausal women has emerged, where both exercise and phytoestrogen supplementation have been deemed effective candidates. However, due to the paucity of intervention studies in postmenopausal women, knowledge gaps remain in these strategies that need to be elucidated in the context of vascular health. This dissertation aims to answer three main questions that will refine the scientific community’s understanding of alternative interventions for vascular health in postmenopausal women: (1) Can exercise training work synergistically with in-vitro dual anti-platelet therapy to improve platelet function, as determined by basal platelet reactivity and prostacyclin sensitivity (Chapter 4)? (2) Does the timing of the initiation of exercise training after menopause affect the degree of vascular adaptations and thrombotic risk profile (Chapters 5 and 6)? (3) Can short-term supplementation with the novel phytoestrogen fermented red clover extract improve markers of vascular inflammation (Chapter 7)? Together, the findings from this dissertation highlight that exercise and fermented red clover extract are effective alternative strategies to improving vascular health in postmenopausal women. Specifically, exercise training improves platelet function and sensitivity and can work synergistically with in-vitro dual anti-platelet therapy (Chapter 4). In addition, short-term supplementation with fermented red clover extract improves the vascular inflammatory profile in recently postmenopausal women (Chapter 7). However, the timing of exercise training after menopause may influence the magnitude of thrombogenic adaptations, as recently postmenopausal women experience more robust thrombogenic benefits than women who are a greater number of years postmenopausal (i.e., late postmenopausal women) (Chapter 5 and 6).Item Open Access The Effects of Heat and Cold on Cognitive Function and Endurance CapacityWallace, Phillip Julian; Applied Health Sciences ProgramThe maintenance of mental and physical function in hot and cold environments is more challenging compared to thermoneutral environments due to increases systemic physiological and psychological strain. The mechanism for impairments in both cognitive and physical function may be due to early perturbations in whole-body heat balance where the change in skin temperature (even before measurable changes in core temperature) impair performance, followed by greater impairments with changes in core temperature. However, the separate and combined effects of changes in skin and core temperature over a range of cognitive functions and exercise require further elucidation. Therefore, this dissertation tested cognitive function (psychomotor processing, working memory, and executive function) and endurance capacity (at 70% of peak power output) over a range of skin and core temperatures and thermal conditions. Chapter 4 investigates the effects of whole-body skin and core warming (hyperthermia) on cognitive function. In addition, the pharmacological drug, methylphenidate (20 mg, dopamine re-uptake inhibitor) was used as it may improve physiological and psychological strain during heat stress. Chapter 5 built upon Chapter 4 by testing the effects of whole-body skin and core cooling (mild hypothermia) on cognitive function. Chapter 6 extended the findings of Chapter 5 by testing the effects of whole-body skin and core cooling on endurance capacity, to potentially see a cognitive-physical performance interaction. Collectively, we found that neither changes in skin temperature (Range: ∆-6 to +4.5°C), without changes in core temperature, nor manipulation of core temperature (Range: ∆-0.8 to +1.5°C) significantly impaired cognitive function in hot or cold environments (Chapters 4 & 5). Furthermore, methylphenidate did not enhance cognitive function. Whereas, endurance capacity was significantly influenced by cold stress, where cooling the skin/outer shell impaired performance by 32%, while core cooling of ∆-0.5C and ∆-1.0C from baseline temperature further impaired performance by 61% and 71% respectively. There were no differences between the two core cooling conditions. Collectively, this research program demonstrates the capacity to maintain cognitive function, but not physical capacity under thermal strain. From a practical standpoint, interventions should focus to minimize cold strain to prevent declines in physical capacity under cold conditions.Item Open Access Understanding Emerging Adults’ Decision-Making Process When Selecting a Smoking Cessation Approach: A Grounded Theory StudyBarkans, Meagan E.; Applied Health Sciences ProgramRates of cigarette smoking have been markedly reduced in recent decades, but young adults (or emerging adults) continue to have the highest rate of tobacco use in Ontario, Canada. Though preventing smoking initiation is optimal, positive outcomes of cessation early in the lifespan make it clear that cessation support for smokers in this age group is critical. Despite research into the effectiveness of quitting approaches and smokers’ preferred approaches to quitting, it remains largely unclear how smokers characterized as emerging adults (Arnett, 2000) make and act upon “real-world” decisions about which cessation approach to use. To learn more about this important aspect of the quitting process, this study investigated emerging adults’ experiences of choosing their approach to quitting. Twenty-six recent quitters between the ages of 19-29 participated in semi-structured interviews. Grounded theory methods were used to develop a framework explaining the decision-making process successful quitters engaged in when choosing a smoking-cessation approach. The newly proposed “Choosing How To Quit” Framework shows a decision making process that includes three distinct phases: Awareness of Approaches; Personal Reflection; Making a Choice. Successful emerging-adult quitters chose a quitting approach by drawing on a variety of sources for information and exploring personal facets including their past experiences, real-life daily-living considerations and an understanding of their present and future-selves. The Framework offers emerging adults and cessation supporters new realistic avenues to consider or explore when making the decision about a cessation approach, potentially leading to a greater likelihood of success. As a preliminary theory, the CHQ Framework requires further investigation, including into which components may be most essential to the decision-making process.Item Open Access Cardiovascular and Inflammatory Consequences of Adverse Childhood ExperiencesDempster, Kylie S; Applied Health Sciences ProgramThis thesis is composed of three investigations which aim to identify changes in cardiovascular and inflammatory health which are present in individuals who have experienced different types of ACEs (i.e., maltreatment, household dysfunction) and the accumulation of ACEs (i.e., <4 and ≥ 4 different ACEs). First, this thesis sought to identify the effects of adversity on change in arterial stiffness and cardiovagal baroreflex sensitivity (cvBRS) from childhood to young adulthood. Study 1 identified significant interactions between ≥ 4 ACEs and time, and maltreatment by time which were associated with a greater increase in systemic pulse wave velocity from childhood to young adulthood among those with a high ACE profile; although this effect only remained significant in maltreatment models after covariates were introduced. Study 1 also observed a significant interaction between ≥ 4 ACEs, time, and sex on the change in cvBRS from childhood to young adulthood with females driving this relationship. Study 2 aimed to determine whether childhood adversity demonstrated an effect on the heart, particularly left ventricular mass (LVM) and left ventricular function, measured as ejection fraction (EF) and fractional shortening (FS). This investigation identified a unique cardiac profile present among individuals who experienced childhood household dysfunction and was characterized by a significantly lower LVM, independent of recent life stress, smoking, physical activity, and inflammation while childhood maltreatment demonstrated a negative effect on EF independent of covariates. Whether this persists into older age is unknown. Notably, Studies 1 and 2 identified the MMP proteolytic family may be involved in subclinical cardiovascular remodeling among those with ACEs and warrants future investigation. Study 3 utilized an acute 60° head up tilt (HUT) to determine whether childhood adversity influenced the hemodynamic and autonomic responses to orthostatic stress. This thesis identified enhanced blood pressure and total peripheral resistance responses and blunted RR-interval, cardiac output, and cvBRS responses to 60° HUT in individuals who experienced ≥ 4 ACEs; suggesting a reduced vagal and likely enhanced sympathetic response to orthostatic stress. Collectively, these studies provide evidence that exposure to ACEs produce unique cardiovascular changes which occur largely in the absence of covariates and enhanced inflammation.Item Open Access Sclerostin influences body composition adaptations to exercise trainingKurgan, Nigel; Applied Health Sciences ProgramSclerostin is a secreted glycoprotein mainly produced by the osteocyte, which inhibits the canonical Wnt/ß-catenin signalling pathway. In mice, genetic deletion, or inhibition of sclerostin with a neutralizing antibody increases bone mass while also improving insulin sensitivity and lipid homeostasis. Despite sclerostin not being expressed by adipose tissue (AT), reductions in white AT (WAT) mass and adipocyte cross-sectional area can also be observed with sclerostin inhibition, ultimately conferring resistance to a high-fat diet. Resting circulating sclerostin has also been shown to decrease following exercise training. This dissertation includes six studies examining the hypothesis that sclerostin influences adaptations in fat mass in response to exercise training. Study 1 did not identify serum sclerostin’s response to acute exercise with a top-down proteomic analysis. Study 2 of this thesis utilized a targeted approach and found sclerostin increases in the circulation transiently following acute exercise in adolescents with excess adiposity while those with normal weight have a blunted response. Study 3 utilized a longitudinal study design and found a diet and exercise intervention that leads to a reduction in fat mass attenuates sclerostin’s post-exercise increase in adolescents with excess adiposity. Study 4 identified sclerostin was present in human AT and decreased following exercise training in adults with excess adiposity. Study 5 characterized sclerostin’s response to acute exercise within serum and WAT depots of a mouse model and showed that serum sclerostin is elevated during recovery only in obese mice compared to lean mice and the monomeric form of sclerostin is reduced in scWAT during recovery from acute exercise and is abolished in visceral WAT in response to an obesogenic diet. Study 6 showed that prevention in the reduction in sclerostin seen with exercise with daily injections of recombinant sclerostin also prevents the reduction in scWAT mass and adipocyte cell size and increased lean mass seen with exercise training. These changes may be related to a shift in fuel utilization. Taken together, this thesis provides evidence that sclerostin is influenced by adiposity and exercise training and fluctuations in sclerostin content can regulate adaptations in fat mass and lean mass, which may be mediated by changes in metabolism.Item Open Access Advancing a Youth-Centered Pedagogy that Fosters Physical Literacy by Working with Youth and YMCA Recreation ProvidersPetersen, Jennie; Applied Health Sciences ProgramParticipation in sport and physical activity declines in children at approximately 11-14 years of age. Efforts to support long-term participation in physical activity have focused on the promotion of physical literacy, which offers a holistic view of the factors affecting youth participation. Limited research has explored pedagogical approaches that can support youth physical literacy and engagement in recreational sport and physical activity contexts. This dissertation investigates pedagogical approaches aimed at supporting youth physical literacy in a YMCA recreation context using action research. An important objective was to support change in YMCA organizational pedagogical practices. Practical implications for the implementation of physical literacy are discussed throughout. Interviews with 10 youth and eight coaches involved in YMCA recreational sport and physical activity programs were conducted in the first study of this dissertation. Factors that supported youth engagement included sense of enjoyment, learning and accomplishment, and comfort with peers in the program. Youth described feeling disengaged when they felt a low sense of autonomy, excluded, or if there was potential for embarrassment. Gender stereotypes were identified as a contributing factor leading to lower levels of participation and engagement in girls. Coaches who had previously taken physical literacy related training perceived improvements in their instructional ability to engage youth. In the second study, 31 youth participated in a series of focus group meetings exploring what approaches to physical literacy resonate amongst youth. During a wrap-up meeting with YMCA stakeholders, youth participants shared their ideas and courses of action. Findings demonstrated that the presence of a caring adult, interacting with peers of a similar age, opportunities to have input and co-create their programs, games-based approaches, and the flexibility of their program structures were important factors for enhancing youth involvement in sport and physical activity. In the last study, a youth-informed recreation instructors training was designed, developed, and co-created with six YMCA stakeholders over the course of seven focus group meetings. A key outcome was the development of a recreation instructor training, called Working ‘with’ Youth in Sport and Physical Activity. Findings provide insight on the challenges that recreation organizations face with implementing physical literacy concepts.Item Open Access Effects of Exogenous Lipopolysaccharide Exposure on Bone Outcomes in Rodent ModelsBott, Kirsten; Applied Health Sciences ProgramChronic low-grade inflammation has been identified as a potential contributor to the pathophysiology of osteoporosis. A key mediator may be lipopolysaccharide (LPS) released from gram-negative bacteria in the gut that can enter circulation stimulating an inflammatory response and upregulate bone resorption. Since rodent models mimic the loss of bone mineral density (BMD) and structure that occurs in humans, rodents offer an accelerated model for studying these inflammation-mediated changes. Therefore, the objective of this thesis was to characterize a rodent model of LPS-induced bone loss using repeated in vivo μCT scans to establish a time course effect of LPS longitudinally and for this purpose three studies were conducted. Study 1 & 2 were run simultaneously using the same control mice. Study 1 demonstrated that repeated irradiation had a negative impact on trabecular bone in both male and female CD-1 mice, while cortical bone was only negatively impacted in the females. In study 2, continuous delivery of exogenous LPS via osmotic pumps for 12 weeks elevated serum LPS in both male and female CD-1 mice but did not alter trabecular or cortical bone structure or BMD at any of the scanning timepoints. Results from Study 2 may in part have been influenced by the effects of repeated irradiation from the in vivo μCT scans at 4-week intervals for a total of 4 scans analyzed in Study 1. In study 3, a systematic review was conducted to better characterize a model of LPS induced bone loss and identify factors that may impact the effects of LPS on bone outcomes in rodent models. Regardless of study duration, exogenous LPS negatively impacted trabecular bone structure and BMD but not cortical bone structure, due to an upregulation in bone resorption. Together these data suggest that exogenous LPS can induce alterations in bone structure and BMD in rodent models, however a clearly defined model of exogenous LPS induced bone loss has yet to be fully characterized.Item Open Access The Role of Protein Following Intense Exercise in Competitive Youth AthletesMcKinlay, Brandon; Applied Health Sciences ProgramThe overall purpose of this thesis was to examine the role of post-exercise dairy protein consumption (isolated and whole-food) on recovery indices (performance and muscle damage) and inflammation following intense exercise within the context of different ecologically valid sporting environments, i.e., acute competition and a short-term period of intensified training, in competitive youth athletes. For this, two studies were conducted. Study 1 (Chapter 3) investigated the effect of whey protein consumption following a high-intensity interval swim session (HIIS) among adolescent swimmers on subsequent performance, muscle soreness, plasma creatine kinase and inflammatory cytokines, compared with isoenergetic carbohydrate and flavoured water in the acute (0–8 h) and short-term (8–24 h) recovery periods. Study 2 (Chapter 4) examined the effects of increased protein consumption, via plain Greek yogurt, compared with an isoenergetic carbohydrate control on performance recovery, inflammation, and muscle damage, during a 5-day simulated soccer training camp in competitive adolescent female soccer players. The collective findings indicate that during both acute and short-term periods of intensified exercise, the provision of dairy protein regardless of form (isolated or whole food), provided no added benefit at enhancing performance recovery or ameliorating muscle damage above that of energy matched carbohydrates. However, it does appear that the consumption of calories, regardless of type (e.g., carbohydrates or dairy protein), when rapid recovery is required, offers greater performance retainment than water. Therefore, during periods of intensified exercise that may be accompanied by inadequate recovery, the replenishment of energy should be the primary focus. Further, in both studies the consumption of dairy protein following exercise leads to an augmented anti-inflammatory response (i.e., increased IL10), not observed in the control conditions (i.e., water or energy-matched carbohydrates). Thus, it is possible that dairy protein consumption post-exercise may benefit the acute immune response. This possibility requires further study.Item Open Access Tea types and their effects on in vitro mineralization and in vivo bone structure and densityMcAlpine, Michael D.; Applied Health Sciences ProgramThe consumption of tea has many proposed health benefits thought to likely be the result of an abundance of unique polyphenols. In particular, one exciting potential health benefit of tea is its capacity to have bone supportive effects when consumed throughout life. Prior to testing the potential bone supportive effects, it was important to characterize several types of tea and determine the ideal steeping time for each tea, maximizing the quantity of polyphenols while also maintaining taste (Study 1). Results from this study were congruent with manufacturer’s recommendations. Following this, several types of teas and tisanes were tested in an in vitro osteoblast model to determine if there were any alterations in quantity of mineral produced (Study 2). Findings demonstrated that all teas effectively increased mineralization at a dietary concentration of polyphenols, but red rooibos tea appeared to produce the greatest effects. The next important aspect which needed to be clarified was if there was an optimal concentration of red rooibos tea that elicited maximal results (Study 3). To determine this, a dose response study was conducted in the same osteoblast model as study 2 and mineral quantity was measured. From this study a positive dose-dependent response was observed without any signs of toxicity, suggesting that high concentrations may be beneficial. Following the initial in vitro studies it was important to test red rooibos tea in a physiologically relevant model of elevated bone turnover, pregnancy and lactation (Study 4). Female Sprague-Dawley rats were randomized to one of the following groups: PREG TEA (pregnant and received a supplemental level of red rooibos: ~2.6 g /kg body weight/day in water), PREG WATER (became pregnant and received water), or NONPREG CON (age-matched, non-pregnant control) from 2 weeks prior to pregnancy (age 8 weeks) through to 4 months post-lactation. Results demonstrated that there were immediate losses of both trabecular and cortical bone following lactation. However, cortical bone rapidly recovered in both pregnancy groups while the majority of trabecular outcomes only partially recovered and appeared to have permanent reductions. When comparing the two pregnancy groups, there were no differences in cortical bone post-lactation but there were significant improvements in several of the trabecular outcomes in rats that received red rooibos herbal tea. The findings from this thesis demonstrated in progressively more complex and physiologically relevant models that tea does have the capacity to be bone supportive, particularly during periods of high turnover.
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