• Influence of timing of milk consumption coupled with endurance training on body composition and endurance training adaptations in humans.

      Euiler, Elizabeth; Applied Health Sciences Program (Brock University, 2014-03-24)
      Consumption of low-fat milk (LFM) after resistance training has been shown to have positive influences on body composition and training adaptations; however, little research has examined the effects of LFM consumption following endurance training. The purpose of the study was to look at the effects of combining additional servings of LFM following endurance exercise on body composition, bone health, and training adaptations. 40 healthy males were recruited. Individuals were randomized into 4 groups – DEI (750mL LFM immediately post exercise), DEA (750mL LFM 4 hrs prior to or 6 hrs post exercise), CEI (750mL carbohydrate beverage immediately post-exercise), and CEA (750mL carbohydrate beverage immediately post-exercise). Participants took part in a 12-week endurance training intervention (1 h/day, 3 d/wk, ~60% max HR). 22 participants completed the study. Analysis showed significant increases in lean mass, spinal bone mineral content, relative VO2peak, and a decrease in Trap 5β across all groups (p < 0.05).
    • Inhibition of allergen-mediated mast cell activation by TAK1 inhibitor 5Z-7-oxozeaenol

      Watson, Colton JF; Applied Health Sciences Program
      Introduction & Aim: Allergic inflammatory disorders are at epidemic levels worldwide. Mast cells drive this inappropriate immune response via release of a variety of pro-inflammatory mediators in response to environmental cues detected by the IgE-FcεRI complex, but we do not fully understand the contributing molecular mechanisms. Transforming growth factor β-activated kinase 1 (TAK1) is a known participant in related signaling through MAPK and NF-κB; however the role of TAK1 in IgE-FcεRI signaling and resultant allergic inflammation remains unknown. We aim to assess the role of TAK1 in IgE-mediated mast cell activation. Methods: Bone marrow-derived mast cells were sensitized with allergen-specific IgE and treated with the corresponding allergen for various times in the presence or absence of 5Z-7-oxozeaenol. Mast cell signaling was measured by western blotting, induced gene expression by qPCR, pro-inflammatory mediator release by ELISA and mast cell degranulation by β-hexosaminidase release assay. Results: TAK1-inhibition resulted in significant impairment in the phosphorylation of various MAPKs (p38, ERK and JNK) as well as NF-κB pathway kinase IκBα. Impaired gene expression of pro-inflammatory cytokines IL-4, IL-6, IL-13, and chemokines CCL1, -2, and -3 were detected. Furthermore, a drastic decrease in the concentration of pro-inflammatory cytokines, IL-6 and TNF, and chemokines CCL1 and CCL2, in stimulated cell supernatants was detected. Finally, a significant inhibition of mast cell degranulation was also observed in the TAK1-inhibited cells. Conclusion and Significance: These results suggest that TAK1 acts as a signaling node linking the MAPK and NF-κB pathways in mast cells responding to allergen and may warrant consideration in future therapeutic development.
    • Inhibition of Free fatty acid-Induced Insulin Resistance by Rosemary Extract: Investigation of the Mechanisms Involved

      Filip, Vlavcheski; Applied Health Sciences Program
      Excess of plasma free fatty acids (FFA) are highly associated with insulin resistance and are a major risk factor for the development of type 2 diabetes mellitus. This thesis investigates the effect of rosemary extract and rosemary extract polyphenols carnosic acid (CA), rosmarinic acid (RA) and carnosol (COH) on recovering/blunting FFA-induced insulin resistance in skeletal muscle cells and the mechanism(s) involved. Exposure of L6 myotubes with the FFA palmitate significantly reduced the insulin-stimulated glucose uptake. Most importantly, the insulin-stimulated glucose uptake was restored in the presence of RE and its polyphenols CA, RA and COH. Furthermore, treatment with palmitate increased serine phosphorylation of IRS-1 and significantly decreased the insulin-stimulated phosphorylation of Akt. These effects were completely abolished in the presence of rosemary extract. Additionally, we investigated the effect of palmitate and rosemary extract on the phosphorylation and of JNK, mTOR, P70S6K and AMPK kinases. Our results indicate that palmitate treatment increased the phosphorylation of JNK, mTOR, p70S6K whereas rosemary extract completely abolished this effect. Additionally, rosemary extract increased the phosphorylation of AMPK even in the presence of palmitate. The expression levels of these proteins were not affected by any of the treatments. These results indicate that treatment with rosemary extract attenuated the palmitate-induced phosphorylation of the serine residues of IRS-1, mTOR, p70 S6K and JNK while increasing the phosphorylation of AMPK. Additionally, treatment with RE restored the insulin-stimulated glucose uptake in palmitate-induced insulin resistant cells.
    • Interaction between stress and immunity during a week leading to competition in young athletes

      Papadopoulos, Efthymios; Applied Health Sciences Program (Brock University, 2013-07-26)
      This study examined changes in the salivary concentrations of immunoglobulin A (sIgA), cortisol (sC), testosterone (sT) and testosterone-to-cortisol ratio (T/C) in 23 competitive swimmers, 11-15 years old, during a week leading to competition as compared to a control (non-competitive) week. Results showed no effect of week or day, and no significant week-by-day interaction for sIgA, sC and T/C. In contrast, sT significantly decreased during the week of competition, along with a 7%, non-significant decrease in the weekly T/C. The latter suggests that the swimmers were in a catabolic state due to their training, but this did not have a negative effect on their performance Since sC did not change over the two weeks and according to the sport anxiety scale, competition stress was relatively low in these peri-pubertal athletes, it is concluded that in the absence of high cortisol levels mucosal immunity is unaffected in young athletes prior to competition.
    • An international investigation on the validity of the CSAPPA scale in screening for developmental coordination disorder /

      Flouris, Andreas D.; Applied Health Sciences Program (Brock University, 2004-05-21)
      The main objective of the present investigation was to continue the research initiated by Hay and colleagues (2004) in examining the efficacy of the Children's Self-Perceptions of Adequacy in and Predilection for Physical Activity (CSAPPA) scale as a proxy for the short form of the Bruininks-Oseretsky Test of Motor Proficiency (BOTMP-SF) in screening for Developmental Coordination Disorder (DCD) in children. To better appreciate DCD knowledge outside Canada, the measurements of this investigation were expanded in Greece. A translated Greek CSAPP A scale and the BOTMP-SF were administered for the first time in Greek children. A second objective was to investigate the relationship between DCD and various risk factors of coronary artery disease (CAD) in Canadian and Greek children. A sample of 591 (Ms=322; Fs=269) Canadian and 392 (Ms=211; Fs=181) Greek children, aged 9 to 13 years, consented to the BOTMP-SF, CSAPP A Scale, participation in physical activity questionnaire, Leger 20-meter Multistage Shuttle Run test, and body fat using bioelectric impedance. Prevalence of DCD in Canada and Greece was 8% and 19%, respectively. Significant agreement (p<O.OOI) was confirmed when comparing the CSAPPA scale to the BOTMP-SF test in both countries. Canadian children revealed significantly lower percent body fat, CSAPPA scores, and participation in physical activity, as well as higher aerobic fitness levels and BOTMP-SF compared to their Greek peers. Clumsiness was associated with increased percent body fat and low aerobic fitness values. Physical activity was a significant mediator in the clumsiness-aerobic fitness relationship. It is concluded that the CSAPPA scale is an accurate, practical, and inexpensive screening tool for DCD, and that motoric competence is associated with aerobic fitness through physical activity participation.
    • Intra-mitochondrial location of the skeletal muscle perilipin 3 and 5 proteins at rest and following electrically stimulated contraction

      Hunter, Mackenzie; Applied Health Sciences Program
      PLIN3 and PLIN5 have been shown to localize to skeletal muscle mitochondria. Hypotheses state that these PLINs could facilitate lipid droplet-mitochondrial interactions, however, this would presumably require that they would localize to the outer mitochondrial membrane (OMM). The purpose of this study was to sub-fractionate skeletal muscle mitochondria at rest and following contraction to determine the precise intra-mitochondrial localization of PLIN3 and PLIN5. At rest, PLIN5 was primarily found in the OMM/intermembrane space (IMS) fraction, however, following contraction there was a redistribution of PLIN5 protein content towards the mitoplasts. PLIN3 protein content localized to the OMM/IMS at rest and was unchanged with stimulation. Co-immunoprecipitation found PLIN5 associated with both ACSL1 and CPT I at rest and following contraction while PLIN3 only associated with ACSL1. CPT I and II also associate, allowing for a link between the two membranes that may help explain the shift of PLIN5 to the mitoplast following contraction.
    • Investigating the Biological Effects of Rosemary (Rosmarinus officinalis L.) Extract on Skeletal Muscle Glucose Uptake

      Naimi, Madina; Applied Health Sciences Program (Brock University, 2014-09-10)
      Skeletal muscle (SKM) is the most important tissue in maintaining glucose homeostasis and impairments in this tissue leads to insulin resistance (IR). Activation of 5’ AMP-activated kinase (AMPK) is viewed as a targeted approach to counteract IR. Rosemary extract (RE) has been reported to decrease blood glucose levels but its effects on SKM are not known. We hypothesized that RE acts directly on SKM to increase glucose uptake (GU). We found an increase in GU (184±5.07% of control, p<0.001) in L6 myotubes by RE to levels similar to insulin and metformin. Carnosic acid (CA) and rosmarinic acid (RA), major polyphenols found in RE, increased GU. RE, CA, and RA significantly increased AMPK phosphorylation and their effects on GU was reduced by an AMPK inhibitor. Our study is the first to show a direct effect of RE, CA and RA on SKM GU by a mechanism that involves AMPK activation.
    • Investigating the effect of isometric handgrip training frequency on cardiovascular health in medicated hypertensives

      Wainman, Liisa; Applied Health Sciences Program
      Hypertension (HTN) is expected to affect approximately 50% of the world’s adult population by 2025 and accounts for 10 million deaths worldwide each year. Historically, HTN has been defined as systolic blood pressure (SBP) greater than 140 mmHg and/or diastolic blood pressure (DBP) greater than 90 mmHg. However, it has been recently suggested that the risks of HTN begin at even lower BP levels and in the United States HTN is now defined as ≥130/80 mmHg. HTN increases the presence of many independent risk factors and/or indicators for cardiovascular disease (CVD) such as increased arterial stiffness and reduced cardiovagal baroreflex sensitivity (cvBRS). This study aimed to investigate the minimum training frequency necessary to maintain decreases in BP following an initial 8-week training period by training individuals 0, 1, or 3 times per week for 4 weeks. Sixteen individuals with medicated hypertension (age 65±9 years) were recruited and performed 8 weeks of IHG 3 times per week and were then allocated to one of 3 training frequency groups; 0, 1 or 3 times for a subsequent 4 weeks. Statistically significant decreases in SBP and DBP were observed in all participants following the initial 8-week IHG training program (-9±10mmHg, p=0.004; -5±6mmHg, p=0.006), as well as at 12 weeks (-9±10 p=0.047; -5±7, p=0.051). cvBRS did not demonstrate any significant changes, while carotid-toe pulse wave velocity (ctPWV), a measure of systemic arterial stiffness, demonstrated a significant main effect for time (p=0.002). Post-hoc testing revealed significant decreases in ctPWV at 12 weeks (-1.0±1.1, p=0.002), as well as a significant decrease from 8 to 12 weeks (-0.73±1.1, p=0.017). As for trained limb arterial stiffness, carotid-radial pulse wave velocity (crPWV) demonstrated a significant effect for group (p=0.045) and time (p=0.015). Post-hoc testing revealed that there was no significant difference between groups, however there was a significant decrease in crPWV at 12 weeks (-1.4±1.7, p=0.010). These findings suggest that IHG at a training frequency lower than traditionally prescribed may maintain the decrease in SBP and DBP with the inclusion of improvements in arterial stiffness both systemically and in the trained limb over time. Thus, these results support the prescription of IHG in the treatment of HTN.
    • Investigating the Effects of Aerobic Exercise with Blood Flow Restriction on Vastus Lateralis Muscle Oxygenation

      Vaantaja, Jonathan; Applied Health Sciences Program
      Blood flow restriction training (BFRT) is a novel adaptation to traditional forms of aerobic or resistance exercise. By restricting blood flow to the active skeletal muscles, previous research has demonstrated that it can induce similar benefits to musculoskeletal health as non-blood flow restricted (BFR) exercise, despite exercising at lower intensities and for a shorter duration of time. The mechanisms through which BFRT stimulates physiological adaptations remains uncertain however, one proposed stimulus is localized skeletal muscle hypoxia. This thesis aimed to investigate this stimulus by assessing muscle oxygenation during low-intensity aerobic exercise with BFR. Vastus lateralis oxygenation was assessed using continuous-wave near-infrared spectroscopy in 15 participants (n=15) during 20 minutes of BFR and non-BFR exercise sessions. Significant differences in muscle tissue oxygenation was observed (P<0.001) indicating that BFR during low-intensity walking exercise reduced muscle oxygenation more so than non-BFR exercise. Furthermore, significant differences in total hemoglobin (THb) and deoxygenated hemoglobin (HHb) were observed (P<0.05 and P<0.001, respectively), such that THb and HHb were significantly greater during BFR-exercise versus non-BFR exercise. Oxygenated hemoglobin (O2Hb) on the other hand, was not significantly different between exercise sessions. These findings suggest that BFR during low-intensity aerobic exercise may induce a localized hypoxic response in the skeletal muscle tissues distal to the cuffs. The reduction in muscle oxygenation in the presence of increased tissue blood volume may suggest that BFRT influences oxygenation by moderating blood flow through the active skeletal muscle tissues during exercise.
    • Investigating the Effects of High-Intensity Interval Training on Baroreflex Sensitivity

      Cameron, Austin James; Applied Health Sciences Program
      Cardiovagal baroreflex sensitivity (cvBRS) is known to be influenced by endurance exercise. In fact, endurance exercisers typically display a greater cvBRS compared to sedentary controls. Despite the merits of endurance training, adherence to exercise is a problem for many individuals. High-intensity interval training (HIIT) protocols generally involve less time and work completed while imparting similar cardiovascular responses compared to endurance training. To our current knowledge, the findings of HIIT and cvBRS have been equivocal. This study investigated the effects of 12-weeks of HIIT on cvBRS and the relationship between cvBRS and measures of arterial stiffness in 16 young, healthy males. Following HIIT, cvBRS appeared to be unchanged along with most measures of arterial stiffness (carotid to femoral pulse wave velocity, common carotid artery (CCA) distensibility, and compliance); however, CCA intima-media thickness (IMT) significantly improved. Systolic blood pressure, a major determinant of cvBRS, was unchanged, while resting heart rate appeared to improve following 12-weeks of HIIT. Therefore, these findings suggest that in this sample, 12-weeks of HIIT does not appear to influence cvBRS.
    • Investigating the Effects of Subclinical Neck Pain, Cervical Treatment, and Neck Muscle Fatigue on Wrist Joint Position Sense

      Reece, Ashley; Applied Health Sciences Program
      The purpose of this work was to evaluate the effects of neck pain, cervical treatment, and neck muscle fatigue on joint position sense of the wrist. 12 healthy participants and 12 participants with chronic subclinical neck pain were recruited. Participants took part in two sessions, separated by 48 hours. On the first day, participants preformed two wrist proprioception sessions using a haptic robotic device separated by an isometric cervical extensor fatigue protocol. On the second day participants performed an additional two proprioception sessions, this time separated either by a neck treatment (pain group) or 20 minutes of rest (control group). Each session consisted of 12 trials; 6 in wrist flexion and 6 in wrist extension. Matching error, error bias and variability were measured for each trial. Kinematic data for each trial was recorded from the robotic device and analyzed. Results showed significantly higher error scores for the pain group when compared to the control group at baseline (p=<0.05). Joint position error scores increased significantly in the control group after the fatigue protocol (p= <0.05). Error scores for the pain group decreased significantly after a single treatment session (p= <0.05). This study confirms that altered afferent input from the neck (due to pain and/or fatigue) can influence wrist joint position sense (JPS). Furthermore, the results suggest that a single treatment can improve wrist JPS accuracy.
    • Investigating the Neuromuscular Response to Sudden Wrist Perturbations

      Forman, Garrick; Applied Health Sciences Program
      The purpose of this work was to evaluate changes in forearm muscle activity and co-contraction caused by sudden wrist perturbations during a dynamic wrist tracking task using a haptic wrist robot. Surface electromyography was recorded from eight muscles of the upper-limb. Participants were seated with their forearm placed on an armrest, grasping the handle of a haptic wrist robot. Participants performed trials consisting of 17 repetitions of ±40° of wrist flexion/extension. During trials, participants received 3 perturbations. Perturbations varied based on condition: radial or ulnar direction, during flexion or extension, and with known or unknown timing. Co-contraction ratios for all muscle pairs illustrated significantly greater extensor activity across all experimental conditions. Expected (known) perturbations produced greater anticipatory muscle activity as well as greater task performance. While improving performance, this increase in anticipatory muscle activity may leave muscles susceptible to early-onset fatigue and chronic overuse injuries in the workplace.
    • Investigating the role of estrogen deprivation and diet-induced insulin resistance on markers of amyloid-β production and degradation in the brain

      Hayward, Grant; Applied Health Sciences Program
      Estrogen loss, which women experience during menopause, has recently been associated with increased amyloid-β (Aβ) peptides, a main feature of Alzheimer’s Disease (AD). Furthermore, diet-induced insulin resistance has also been shown to increase Aβ; however, whether this process is exacerbated with the loss of estrogen remains unknown. We aimed to investigate the effects of estrogen loss on amyloid production and degradation pathways, as well as markers of insulin signaling, glucose uptake and synaptic function, in an insulin resistant mouse model. To do this, female C57BL/6J mice received either bilateral ovariectomy, to simulate estrogen loss, (OVX; n=20) or remained intact (n=20) at 24 weeks of age. Mice were then placed on either a low or high fat diet (LFD; n=10 for OVX and intact, HFD; n=10 for OVX and intact) for 10 weeks to induce insulin intolerance. Prefrontal cortex and hippocampus tissues were then isolated and markers of amyloidogenesis, Aβ degradation, insulin signaling, glucose uptake, and synaptic function were examined. Independently, OVX led to increases in the amyloidogenic marker, sAPPβ. Furthermore, HFD combined with OVX, led to lower IDE protein content and activity in the prefrontal cortex, indicative of decreased Aβ degradation. Lastly, HFD with OVX led to exacerbated decreases in pGSK-3β /GSK, GLUT1, and Homer-1 (a postsynaptic marker) in the hippocampus, and GLUT3 in the prefrontal cortex. Data from this study provide evidence of a synergistic effect of systemic insulin resistance and estrogen loss in decreasing brain markers of Aβ degradation, insulin signaling, glucose uptake, and synaptic function. Furthermore, findings indicate how the loss of estrogen can promote the formation of amyloidogenic APP cleavage products, independent of diet-induced insulin resistance. These results ultimately contribute to our understanding of both estrogen-deprivation and insulin resistance on female brain health in relation to AD progression.
    • Investigation of Periodontal Outcomes After Sanative Therapy Among Patients With or Without Dry Mouth

      Sparrow, Taylor; Applied Health Sciences Program
      Untreated periodontal disease can have detrimental consequences on oral health. Consequences such as tooth loss can significantly affect an individual’s daily habits such as eating, speaking, and socializing. Sanative therapy (ST) followed by ongoing periodontal maintenance appointments is necessary to attenuate periodontal disease and prevent tooth loss. In addition to ST and periodontal maintenance appointments, saliva has an essential role in oral health. However, the relationship between salivary flow and periodontal outcomes, particularly in terms of low salivary production, has not been extensively investigated. The first objective was to determine if patients with dry mouth have similar probing depths as patients without dry mouth when receiving regular periodontal maintenance post-ST. The second objective was to determine if patients who alternate periodontal maintenance appointments between a general dental clinic and a periodontal specialty clinic have different probing depths than patients who solely have periodontal maintenance at a periodontal specialty clinic post-ST. Patients who had completed initial ST 1 to 5 years prior and continued with routine periodontal maintenance provided an unstimulated saliva sample and completed questionnaires assessing their symptoms of dry mouth. It was hypothesized that patients who have inadequate salivary flow exhibit worsened probing depths than patients who have adequate salivary output. However, periodontal health was maintained post-ST to present day for both groups. The second hypothesis was that patients who have periodontal maintenance performed solely at a periodontal specialty clinic have improved periodontal outcomes than those who alternate appointments 1 to 5 years post-ST There was a significant difference in probing depth between patients who do or do not alternate appointments (p < 0.05). Patients who do not alternate appointments had significantly greater probing depth than those who alternate. This may be due to the periodontist’s recommendation for patients of unstable periodontal health to be solely seen at specialty clinic.
    • Investigation of the anti-cancer effects of rosemary (Rosmarinus Officinalis L.) extract in human breast and prostate cancer cells

      Jaglanian, Alina; Applied Health Sciences Program
      Breast and prostate cancer are the most frequently diagnosed cancers in women and men respetively, in North America. Triple-negative breast cancer (TNBC) cells do not express estrogen receptor, progesterone receptor, and human epidermal growth factor receptor-2 (HER-2). TNBC accounts for 15% of all breast cancer cases, is aggressive in nature, and is characterized by resistance to chemo and radiotherapy thus, finding new approaches to inhibit it are urgently needed. Similarly, prostate cancer is typically characterized by the expression of androgen receptor (AR) and prostate-specific antigen (PSA). Prostate cancer that is AR positive can be treated with hormonal therapy. In contrast, AR negative prostate cancer is more aggressive and does not respond to hormone therapy, thus new approaches, including identifying specific signaling molecules that are overactivated and could be targeted, are required to effectively treat this subtype of prostate cancer. Rosemary extract (RE) has been shown to have anti-cancer properties in vitro and in vivo. However, limited evidence exists regarding its effect on triple-negative breast cancer and AR negative prostate cancer. In this study, we examined the effects of RE on triple-negative breast cancer cell (MDA-MB-231) and androgen insensitive prostate cancer cell (PC-3) proliferation, survival/apoptosis, and migration. In addition, we investigated the effect of RE treatment on key signaling molecules involved in cancer cell proliferation and survival.
    • Investigation of the Biological Effects of Rosemary (Rosmarinus Officinalis L.) Extract in Human Lung Cancer Cells

      Moore, Jessy; Applied Health Sciences Program
      Cancer cells display enhanced growth rates and a resistance to apoptosis. Lung cancer accounts for the most cancer related deaths and non-small cell lung cancer (NSCLC) represents an aggressive form of lung cancer, accounting for almost 80% of all lung cancer cases. The phytochemical rosemary extract (RE) has been reported to have anticancer effects in vitro and in vivo however, limited evidence exists regarding the effects of RE and its polyphenolic constituents carnosic acid (CA) and rosmarinic acid (RA) in lung cancer. The present study shows RE, CA and RA inhibit lung cancer cell proliferation and survival in various NSCLC cell lines and that CA and RA interact synergistically to inhibit cell proliferation. Moreover RE, CA and RA are capable of altering activation and/or expression of Akt, ERK and AMPK, signaling molecules which regulate cell proliferation and survival. RE shows potential as an anticancer agent and should be further investigated.
    • Investigation of the Expression of Glucose Transporter Proteins in Human Cancer Cells

      Barron, Carly; Applied Health Sciences Program (Brock University, 2012-08-15)
      Cancer cells are known to display increased glucose uptake and consumption. The glucose transporter (GLUT) proteins facilitate glucose uptake, however, their exact role in cancer metabolism remains unclear. The present study examined mRNA and protein expression of GLUT1, GLUT3, GLUT4 and GLUT12 in lung, breast and prostate cancer cells and corresponding noncancerous cells. Additionally, GLUT expression was determined in tumours from mice xenografted with human cancer cells. Differences in the mRNA and protein expression of GLUTs were found between cancerous and corresponding noncancerous cells. These findings demonstrate abundant expression of GLUT1 in cancer and highlight the importance of GLUT3 as it was expressed in several cancer cells and tumours. GLUT expression patterns in vitro were supported by the in vivo findings. The study of GLUT protein expression in cancer is important for understanding cancer metabolism and may lead to identification of biomarkers of cancer progression and development of target therapies.
    • Investigation of the Time Dependent Influence of Extracellular Osmotic Stress on Protein Turnover in Skeletal Muscle Cells

      McAlpine, Michael; Applied Health Sciences Program
      Acute alterations in cell volume can substantively modulate subsequent metabolism of substrates. However, how such alterations in skeletal muscle modulate protein metabolism is limited. The purpose of this study was to determine the time dependent influence of extracellular osmotic stress on protein turnover in skeletal muscle cells. L6 cells were incubated in hyperosmotic (HYPER; 425.3 ± 1.8mmol/kg), hypo-osmotic (HYPO; 235.4 ± 1.0mmol/kg) or control (CON; 333.5 ± 1.4mmol/kg) media for 4, 8, 12, or 24hrs. During the final 4hrs, incorporation of L-[ring-3,5-3H]-tyrosine was measured to estimate protein synthesis. Western blotting measured markers of protein synthesis and degradation. No differences were observed in any outcomes except p70S6K phosphorylation whereby HYPO was lower (p<0.05) than CON and HYPER; which remained similar except for a large increase at 8hrs for HYPER. These findings suggest that regardless of duration, extracellular osmotic stress does not significantly affect protein metabolism in L6 cells.
    • Investigative links between cognitive function and moderate-to-vigorous physical activity in elementary physical education

      Pirrie, A. Melissa.; Applied Health Sciences Program (Brock University, 2008-06-01)
      Research has noted both physical and psychosocial benefits when children participate in regular physical activity. Recent studies are indicating that there may also be academic benefits and that students may be more efficient learners with participation in physical activity. This study investigated the influence of acute moderate-to-vigorous physical activity on four cognitive functions: planning, attention, simultaneous processing, and successive processing. Three classes (59 students) were each tested twice using a balanced design (intervention, balance, and control groups). It was found that the intervention group had a large increase in planning abiHty (ES = 1.67) when compared to the balance (ES = .80) and control (ES = -.89) groups. On the three remaining cognitive functions, the intervention group showed effect sizes similar to that of the balance and control groups. These results indicate that improved planning after physical activity may playa role in improving student performance.