Recent Submissions

  • Waveform analysis of forearm muscle activity during dynamic wrist flexion and extension: Effects of forearm posture and torque direction

    Parkinson, James; Applied Health Sciences Program
    Background and Aim: For both isometric and dynamic movements at the wrist, a popular analysis technique for forearm muscle activation includes averaged time-series data that may not represent changes in muscle activity throughout the task. Changes in muscle fiber length and environmental stimuli can alter forearm/upper arm muscle activity during dynamic tasks (D. A. Forman et al., 2020a). The purpose of this study was to determine the effects of forearm posture and torque on forearm muscle activity using waveform analysis. Methods: 12 participants performed a controlled wrist flexion/extension (±40°) tracking task using a wrist manipulandum. Participants were positioned in a neutral, 30° pronated, or 30° supinated forearm posture and the manipulandum applied a constant torque that resisted either wrist extension or flexion. Posture-torque combinations were performed once each, with six flexion/extension repetitions completed per condition. Wrist kinematics were tracked using the manipulandum and the movement cycle was time normalized. Surface electromyography from eight forearm/upper arm muscles were normalized to maximum voluntary contractions. Statistical non-parametric mapping analyzed waveforms for each muscle using a two-way repeated measures ANOVA for main/interaction effects (p=0.05), with post-hoc t-tests. Results: All muscles showed main effects for both posture and torque direction. Decreases in activity were observed in non-neutral forearm postures (flexors: 53-70%, extensors: 5-23% of the cycle). Flexion torque increased muscle activity for FCR, FDS, and FCU during 0-56% and 75-100%, 9-81%, and 22-51% of the movement cycle, respectively. ED and ECU had significantly increased activity during 0-26% and 70-100% of the movement cycle during the extension torque direction. During the neutral-flexion condition, FCR activity increased compared to all other conditions during 58-70% of the movement. Conclusion: When evaluating the entire waveform, non-neutral forearm postures decreased activity for all muscles during specific ranges. The extension torque increased ED and ECU activity at the start and end of the movement, while the flexion torque increased FCR and FDS activity for the majority of the movement. Also, FCR was important in supporting wrist extension during the neutral-flexion condition. Waveform analysis demonstrated complex forearm muscle activity patterns that could provide insight into neuromuscular control, performance, and fatigue progression.
  • Supporting Physical Activity in Pregnancy

    Buchanan, Sabrina; Applied Health Sciences Program
    Physical activity is considered a key therapy for reducing obstetric complications, yet more than 3 in 4 individuals fail to meet physical activity recommendations during pregnancy (Gaston & Vamos, 2012). Differing approaches to physical activity counseling have been implemented to address this issue (Pearce et al., 2013). This study aimed to investigate the effect of one such counseling method, termed motivational interviewing (MI; Miller & Rollnick, 2013). It involved two approaches for communicating physical activity information – a guiding style embodying the autonomy-supportive mindset of MI, or a directing style involving specific advice and recommendations. Each of these approaches was depicted through a written vignette, showcasing a consult between an exercise professional and a pregnant client. Based on random assignment, participants (N = 123) read one of the two vignettes, then indicated the vignette client’s physical activity level for three time points post-consult. Participants assigned to the guiding style (n = 56) reported higher scores on the six manipulation check items compared to those assigned to the directing style (n = 67). While the mixed model ANOVA demonstrated no significant group × time interaction effect, the analysis revealed a significant main effect of group and time on physical activity levels. Specifically, those in the guiding style condition reported more physical activity on average than those in the directing style condition, with levels decreasing over time in both groups. In sum, a guiding communication style, generated in accordance with MI-based evidence, shows promise for improving prenatal physical activity levels and merits further investigation.
  • "The things I do for sport": Associations with mental health in student-athletes.

    Brown, Maxwell James; Applied Health Sciences Program
    Literature concerning university sport suggests that student-athletes make a myriad of behavioural sacrifices (e.g. pain, academics, sleep) to support their participation. While willingness to sacrifice has been linked with a host of positive outcomes (e.g., cohesion), whether athlete behavioural sacrifice is linked to mental health is currently unclear. The purpose of this study was to examine the relationship between behavioural sacrifice and mental health in university student-athletes. Using a non-experimental design, university student-athletes (N = 45; Mage = 20.02) completed a multi-item questionnaire tapping behavioural sacrifice, the Warwick-Edinburgh Mental Wellbeing Scale, and the Perceived Stress Scale. Participants did report making sacrifices for their sport, with sacrifice of leisure activities and sleep being most common. Results of bivariate correlations between behavioural sacrifice and mental health were in directions hypothesized, yet none reached conventional levels of significance (p > .05). Further, behavioural sacrifice did not significantly predict mental health. Results of the study showcase that student-athletes do make a variety of sacrifices to accommodate the demands of university sport. Additionally, findings surrounding mental health support the need for further investigation into sacrifices made within sport to develop a better understanding of associated outcomes.
  • The role of mitochondrial membrane phospholipids in muscle mass homeostasis during overloading

    Vidal, Daislyn; Applied Health Sciences Program
    Skeletal muscle is a structurally intricate and heterogenous tissue made up of individual fibers that differ in size, metabolic and contractile properties, and differs within and between organisms. Skeletal muscle is also very dynamic and can adapt to external stimuli supported by a number of cell signalling pathways. For example, muscle cells can increase in size via a process known as hypertrophy which has been studied using different models such as tenotomy. It has been shown in a rodent model of compensatory plantaris muscle hypertrophy induced by soleus and gastrocnemius tenotomy that cardiolipin (CL, mitochondrial membrane phospholipid) content and composition and tafazzin (Taz, CL remodelling enzyme) protein expression increases. However, it is still not known if protein content changes to Taz, or enzymes responsible for CL biosynthesis, precede or follow changes to CL content and composition during this adaptive response. As such, this study examined the temporal relationship (days 3, 7, 10, and 14) between the protein content of CL biosynthetic and remodelling enzymes and CL content on the adaptive response of skeletal muscle to mechanical overload via tenotomy. There was a decrease in CL despite no change in Taz protein content. Of the CL biosynthetic enzymes examined, PGS1 and CRLS1 showed significant increases in protein content post tenotomy. The greatest fold changes in TAMM41 and CRLS1 occurred simultaneously to that of CL, while PTPMT1’s changes occurred both simultaneously and after changes in CL content. PGS1 did not show any fold changes. Finally, the content of PE and PC (substrates of Taz for CL remodeling), both did not change. Thus, it can be inferred that 14 days post tenotomy in overloaded plantaris, de novo CL biosynthesis is not required but instead may rely on currently available CL for remodelling with no required change to Taz content.
  • Pediculus humanus capitis as a potential vector for Acinetobacter baumannii

    Larkin, Kelsey; Applied Health Sciences Program
    Abstract Introduction: The presence of bacterial pathogens in the human head louse, Pediculus humanus capitis, has been subject to intense research in the last decade. Of particular interest, investigations from several countries in Europe, Asia, and Africa coincide in reporting Acinetobacter baumannii, a known opportunistic bacterium causing frequent health-care associated outbreaks. No reports from countries in South America have been published and is important to confirm whether this pathogen is also present in head lice in this continent. Objective: The aim of the present study was to determine whether Acinetobacter baumannii was present in head lice specimens collected from three countries in Latin America. Methods: 123 vials containing 368 head lice collected from Argentina, Colombia, and two locations in Honduras (La Hicaca and San Buenaventura), were analyzed in pools using PCR to determine the presence of A. baumannii DNA. Results: Two vials containing 3 insects halves each from La Hicaca, Honduras were positive for A. baumannii. Since lice were analyzed in pools, it is not possible to calculate an exact frequency of infection in lice. However, based on whether per each vial one, two or all three lice were positive for A. baumannii, a range can be determined between 1.83 - 5.50%. positivity. Genetic sequencing was used to verify our positive results. The remaining lice from Argentina, Colombia, and San Buenaventura; Honduras were identified as negative for the DNA of A. baumannii under the test conditions described. Conclusion: This study is the first to report the presence of Acinetobacter DNA in human head lice from Latin America. Further investigations are required to elucidate the significance of this finding.
  • Subjective cognitive decline and related worry: Examining biopsychosocial correlates in mid-age and older Canadians

    Hopper, Shawna; Applied Health Sciences Program
    Introduction: Subjective cognitive decline (SCD), a self-reported decline in cognition in otherwise cognitively healthy people, has been acknowledged as a risk factor for Alzheimer’s disease. Using data from the Canadian Longitudinal Study on Aging (CLSA), a large national study with participants ages 45-85 at baseline, we sought to identify correlates of SCD and SCD-related worry. Methods: In our primary analysis using a Poisson regression model, associations between biopsychosocial variables and SCD were identified (analytic sample: n=21,920). In a second analysis using an ordinal regression model, associations between biopsychosocial variables and SCD-related worry were identified (analytic sample: n=12,694). Results: Multiple risk and protective factors of cognitive decline were not associated with SCD within our sample (i.e., physical activity, hypertension, vision problems), as well as minority stress variables such as sexual orientation and race. Rather, psychosocial variables (i.e., depression, perceived social status, and personality traits) showed a more consistent association with SCD within the sample. Greater SCD-related worry, which is believed to increase the risk of future dementia, was associated with specific personality traits, depression, age, gender, and sexuality. Conclusion: The results from this study confirm the association between multiple health variables and SCD but also emphasize the importance of considering psychological and social factors when conceptualizing SCD and its risk factors.
  • 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.
  • 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.
  • 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, 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.
  • Investigating the Effects of a Task-Specific Fatigue Protocol on Hand Tracking Performance Using a Wrist Robotic Device

    Fortaleza, Alvin; Applied Health Sciences Program
    The purpose of this work was to evaluate the effects of a dynamic submaximal fatigue protocol and forearm/hand anthropometrics on hand tracking performance. Participants traced a 2:3 Lissajous curve using a haptic wrist robotic device (WristBot). This same curve was traced before the fatigue (baseline), during the fatigue protocol, and after the fatigue protocol. Post fatigue trials were completed at 0, 1, 2, 4, 6, 8, and 10 minutes after the cessation of the fatigue protocol. Overall tracking performance and movement smoothness decreased immediately. Directional biases in the normal and longitudinal component of tracking error were present after the fatigue protocol. Proximal forearm circumference and forearm length had a negative correlation with movement smoothness. Hand tracking performance decreased due to the submaximal fatigue protocol. Those with a larger proximal forearm circumference and longer forearm length had better movement smoothness performance which can be applied to the workplace where hand and wrist are predominately used.
  • The Influence of Occupational Footwear on Slip Responses

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

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

    Langille, Jordan; Applied Health Sciences Program
    Background: The mean power frequency (MPF) of an electromyographic (EMG) signal is affected by contraction intensity and muscular fatigue but is also a potential indicator of motor unit (MU) recruitment. Methods: This study is a secondary analysis (Woods et al. 2019) in which participants (17 boys, 20 men) completed a progressive isometric contraction protocol while EMG was recorded from the vastus lateralis (VL), using tripolar surface electrodes. MPF and EMG threshold (EMGTh) were calculated for each completed intensity. The latter reflects the onset of accelerated increased in higher-threshold MU recruitment. Independent t-tests were used to assess differences between groups in demographic variables, mean MPF (MPFmn), peak MPF (MPFPK), force (%1RM) at MPFPK, and MPF range. An ANOVA for repeated measures was used to assess differences between groups in MPF pattern, interpolated over ten stages. A correlation analysis was used to assess the relationship between %1RM at MPFPK and %1RM at EMGTh. Results: Both, MPFmn and MPFPK were higher in the men, but only reached statistical significance when %body fat was used as a covariate in the statistical analysis. 65% of participants displayed an expected (inverted-U shape) MPF pattern. Within this subset, the %1RM at which MPFPK occurred was significantly higher (i.e., occurred later) in the boys compared with the men. Additionally, a moderate correlation was observed between the %1RM at MPFPK and the %1RM at EMGTh (r = 0.51). Discussion: Overall, the findings of the current analysis provide support for the hypothesis of lower type-II MU activation in children. The high variability in MPF patterns may be a result of the interaction between confounding factors that affect MPF (intensity and fatigue). Future research should use an exercise protocol that examines MPF under the influence of each factor separately.
  • GSK3 signalling in DBA/2J mdx mice: a comparison against the traditional C57BL/10 mdx model and investigation into its pathogenic contribution

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

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

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

    Columbus, Allison; Applied Health Sciences Program
    Athlete mental health and associated components (e.g., ill-being, role of the coach, mental health literacy) have become a focal point in athletics and research, however, little attention has been given to positive mental health (i.e., well-being). The primary objective of this study was to observe variation in university athlete well-being. A secondary purpose was to assess the influence of injury and internal training load (i.e., RPE) on athlete well-being. Using a non-experimental longitudinal research design, female university basketball players (N = 11; Mage = 20.29 years) provided self-report data via the mobile application AthleteMonitoring™ for 22 consecutive weeks. Well-being was assessed using the 7-item Short Warwick-Edinburgh Mental Wellbeing Scale (SWEMWBS; Stewart-Brown et al., 2008). Injury and internal training load data was collected via self-report. Athletes reported ‘average’ well-being across the 22-week data collection period based on SWEMWBS scores (M = 22.76; SD = 1.98). Repeated-measures Analysis of Variance indicated statistically significant differences in well-being (F(3.54, 35.42) = 3.24, p = .027; np2 = .25). Magnitude-based differences showcased considerable variability in individual athlete’s well-being trajectories over 22 weeks. SWEMWBS scores did not differ by injury status of the athlete, nor were they predicted by internal training load. Given the interpretation of aggregate scores and individual trajectories in this study, it is clear that university female basketball athletes experience fluctuations in their well-being. The results of this study support the need for further investigation into athlete well-being and more specifically, the aspects that influence it.
  • The Role of ASK1 in Allergen-mediated Mast Cell Signaling and Activation-dependent Inflammatory Responses

    Rouillard, Melissa M; Applied Health Sciences Program
    The prevalence of allergies has been increasing at alarming rates and identifying key targets in allergen-induced mast cell-mediated inflammation is crucial for therapeutic development. Apoptosis signal-regulating kinase 1 (ASK1) is a mitogen-activated protein kinase (MAPK) that is involved in various cellular responses, including oxidative stress, high calcium concentrations and receptor-mediated inflammation. ASK1 has been known to be a key player in various inflammatory-based pathologies, such as liver, kidney, and cardiovascular disease, and has been investigated in various immune cells such as neutrophils, macrophages, and dendritic cells. However, its role in IgE-FcERI-activated mast cells remains elusive. The purpose of this project is to expand on current knowledge of MAPK signaling and the role of ASK1 in mast cell-mediated allergic inflammation. Bone marrow-derived mast cell and fetal liver-derived mast cells were sensitized with TNP-BSA-specific IgE antibodies and stimulated following treatment with various GS-444217 treatment concentrations. GS-444217 (ASK1-IN) is a potent and ATP-selective ASK1 inhibitor. Following incubation of various inhibitor concentrations, IgE-mediated mast cell degranulation responses were significantly reduced in both BMMC and FLMC models. Other mast cell signaling responses in BMMCs, such as protein/mRNA expression, cytokine/chemokine secretion, receptor expression, and cell viability were also investigated. Through western blotting, our results show that GS-444217 does not alter JNK, p38, ERK, or ASK1 protein levels. Phosphorylation of ASK1 could not be detected, however the presence of ASK1 in mast cells has been identified. qPCR data also shows that there were no alterations in TNF-a-, IL-6-, CCL2-, and CCL3 mRNA expression following ASK1-IN treatment. Interestingly, contrary to mRNA expression levels, 5µM ASK1-IN treatment caused a significant reduction in CCL1, IL-6, and IL-13 secretion. Lastly, two key receptors associated with IgE-mediated mast cell activation – c-kit and FcERI – showed no changes in expression following inhibitor treatment. Cell metabolic activity was also investigated to ensure cell viability and no significant changes occurred compared to controls. Our results suggest that ASK1 may play a role as an upstream regulator in secretory mechanisms in mast cell-directed allergic inflammation and may warrant future consideration as a therapeutic target candidate.
  • Impacts of the COVID-19 Pandemic on Body Mass, Physical Activity and Nutrition in Canadian Post-Secondary Students

    Bell, Madison; Applied Health Sciences Program
    This study examined changes in body mass, physical activity, and dietary intake and habits in Canadian university students during the first (March – September 2020) and second (October 2020 – March 2021) lockdown/restrictions of the COVID-19 pandemic. Two observational, self-reported recall surveys were conducted online; in September 2020 (T1) and March 2021 (T2). Five hundred ten (99 males, 411 females) students completed the survey at T1 and 135 of them also completed the survey at T2. The surveys included demographic information (age, sex, living arrangements, activity level, etc.), body mass and height, and a series of standardized questionnaires on eating habits and behaviours, as well as energy, macronutrient, and micronutrient intake. Body mass and body mass index increased in both males and females. Body mass increased on average by 0.91 kg, t(132) = -2.7, p = 0.008, 95%CI = [0.24, 1.58]. Importantly, a significant change was shown that between T1 and T2 with a greater number of participants identified as overweight (19.8% to 24.4%) than normal weight (61.7% to 54.8%). Body mass change was not associated with changes in physical activity and dietary intake. Females were more likely to decrease At Home Workouts compared to males with no other significant changes detected for type of physical activity in either T1 or T2. Energy intake significantly decreased by ~200 kcals/d. Diet quality also changed in both sexes characterized by negative changes in in both macro and micronutrients. Restrictive eating behaviours were found to increase significantly in females and were more frequent in those with eating disorders. Therefore, modest weight gain did occur during the pandemic in Canadian university students despite the insignificant changes reported in physical activity and the decrease in overall dietary intake, which can be possibly attributed to the changes in diet quality and dietary behaviours.
  • The Big Five Personality Traits and Choking Susceptibility

    Thiessen, Burgandy; Applied Health Sciences Program
    Choking susceptibility is the likelihood or potential of an individual choking under pressure (Mesagno et al., 2012). Choking susceptibility may be influenced by personality traits. The purpose of this study was to examine the differences between the Big Five personality traits on choking susceptible and choking non-susceptible individuals. A protocol developed by Mesagno et al. (e.g., 2008; 2009), comprised of a self-consciousness scale, sport anxiety scale, and coping style scale, was used to measure choking susceptibility. Personality traits were measured using the Big Five Inventory-10. A total of 60 post-secondary students were analysed in this study; 30 were choking susceptible and 30 were choking non-susceptible. A MANOVA showed a significant effect of the personality traits on choking susceptibility. Separate univariate tests on the outcome variables (i.e., neuroticism, openness, extraversion, agreeableness, and conscientiousness) revealed a significant effect for neuroticism. Additionally, a discriminant function analysis further showed that neuroticism contributed the most to choking susceptibility compared to the other four personality traits. According to the current study, individuals higher in neuroticism are more choking susceptible than those lower in neuroticism. Therefore, individuals who are neurotic may benefit from interventions designed for their personality to combat the likelihood of choking under pressure. This study is the first to use Mesagno’s choking susceptibility protocol outside of sport.

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