Fast medio-lateral movements, frequent in a number of sports activities, are associated with lower extremity injuries. These injuries may occur as a result of excessive musculoskeletal stresses on the joints and their associate structures. The purpose of this study was to investigate the effect of running speed and turning movement on the three-dimensional moments at the ankle, knee, and hip joints. Data were collected using video cameras and force plate. Eight male recreational basketball players were tested during slow (1.5 m/s), moderate (3.0 m/s), and fast running (4.5 m/s) and when cutting to the right or left (+60, +30, 0, -30, and -60��). The inverse dynamics approach was used to integrate the body segment parameter, kinematic and force plate data, and to solve the resultant joint moments. At the ankle joint, inversion/eversion, dorsi/plantar flexion, and internal/external rotation moments of the ankle joint increased with running speed (p<.05). At the knee joint, flexion/extension and abduction/adduction moments increased with running speed except flexion moment that decreased with running speed (p<.05). At the hip joint, internal/external rotation, flexion/extension, and abduction/adduction moments increased with running speed (p<.05). In medial cutting movements, greater abduction moments of the ankle, adduction moments of the knee and external rotation and adduction of the hip were found (p<.05). In lateral cutting movements, greater inversion and adduction moments of the ankle, abduction moments of the knee and hip were found (p<.05). These findings reinforce the intuitive notion that fast medio-lateral turning movements produce substantially greater musculoskeletal loading on the joint structures than does straight running and consequently have greater potential for inducing lower extremity injuries such as ankle sprain or anterior cruciate ligament injury. / Graduation date: 1999

Given the high risk of relapse during the first year of exercise involvement, it is important to determine the processes of self-motivation which enable novice exercisers to become long-term maintainers. This study was designed to extend previous Stages of Change (Prochaska & DiClemente, 1983) research by comparing the Possible Selves (Markus & Nurius, 1986) of individuals at different points within the Maintenance stage of exercise. Participants consisted of female university employees, spouses, and dependents age 35-59 years who volunteered for the study. Participants completed the Stage of Exercise Scale (SOES; Cardinal, 1995) and a self-administered form of the Possible Selves Inventory (Cross & Markus, 1991) which was adapted to address the exercise domain. Women classified by the SOES as being in the Maintenance stage of exercise V=92) were assigned to one of three groups based on the duration of their exercise maintenance (6 months-5 years, 6-10 years, and 11-20 years). The three maintenance groups were compared with regard to the number and category of open-ended and exercise-related possible selves and the self-efficacy and outcome expectancy associated with three focused selves (most important, exercise-related, and exercise-specific). The results indicated that the three maintenance groups did not differ significantly in their possible selves. These findings provide support for the current conceptualization of the Stages of Change Model (Prochaska & Di Clemente, 1983) and suggest that differences between novice and expert maintainers may be behavioral, rather than cognitive, in nature. Several implications for intervention design and suggestions for future research are discussed. / Graduation date: 1998

Graduation date: 1998

As the aging population continues to grow worldwide, age-related complications are becoming more apparent within the aging population. One of the first age-related complications to become apparent is age-associated memory impairment and it can make the elderly more dependent on caregivers early on. The N-methyl-D-aspartate (NMDA) receptor is important to learning and memory and appears to be especially vulnerable to the process of aging. The density of NMDA receptors declines with age more than any other ionotropic glutamate receptor. Both the density of NMDA receptors and the mRNA and protein expression of its subunits decline with age. In particular, the GluN2B subunit of the NMDA receptor shows the greatest age-related declines in expression across multiple brain regions, including the frontal lobe (including the prefrontal and frontal cortices), caudate nucleus and hippocampus. These declines are strongly correlated to age-related declines in spatial memory. Specifically, age-related decreases in the protein expression of the GluN2B subunit within crude synaptosomes of the frontal cortex of C57BL/6 mice show a relationship to the declines in performance in a long-term spatial memory task across age groups. However, within the population of aged mice, there was a subpopulation of aged mice in which higher expression of the GluN2B subunit within the synaptic membrane of the hippocampus was associated with poorer performance in the same task. Moreover, transgenic mice designed to express higher levels of the GluN2B subunit from birth also possess superior memory, including spatial memory, across adulthood to middle-age. Taken together, these data led to the hypothesis that increasing the expression of the GluN2B subunit within the aged brain could potentially alleviate age-related declines in memory. However, increasing its expression regionally was first examined since higher expression of the GluN2B subunit within the hippocampus has been associated with poorer memory in aged animals. Since age-related decreases in the protein expression of the GluN2B subunit within the frontal cortex show a relationship to impaired memory function, the first study was designed to determine if increasing GluN2B subunit expression in the frontal lobe would improve memory in aged mice. Mice received bilateral injections of either an adenoviral vector, containing cDNA specific for the GluN2B subunit and enhanced Green Fluorescent Protein (eGFP) (GluN2B vector); an adenoviral vector containing only the cDNA for eGFP (control vector); or vehicle into their frontal lobe. Spatial memory, cognitive flexibility and associative memory were assessed using the Morris water maze. Aged mice, with increased GluN2B subunit expression in the frontal lobe, exhibited improved long-term spatial memory, comparable to young mice, in the second day of training. Moreover, a higher concentration of the specific GluN2B antagonist, Ro 25-6981, was required to impair long-term spatial memory in aged mice with enhanced GluN2B subunit expression, as compared to aged controls. The requirement for greater antagonism in aged mice to block memory performance suggests that the number of GluN2B-containing receptors in their frontal lobe was enhanced and contributed to the improved memory. This study provides suggestive evidence that therapies that enhance GluN2B subunit expression within the aged brain could have the potential to ameliorate age-related memory loss. Since higher expression of the GluN2B subunit within the hippocampus of aged mice is associated with poorer memory, the second study was designed to determine if increasing GluN2B subunit expression in the hippocampus would improve or further impair memory in aged mice. This would help to determine if a therapy aimed at enhancing the GluN2B subunit expression or function of GluN2B-containing receptors throughout the aged brain could help ameliorate age-associated memory loss. Mice were injected bilaterally with either the GluN2B vector, a control vector or vehicle into the hippocampus. Spatial memory, cognitive flexibility and associative memory were assessed using the Morris water maze. Aged mice, with increased GluN2B subunit expression in the hippocampus, exhibited improved long-term spatial memory, comparable to young mice, early in training. However, there was a trend for impaired memory later in the long-term spatial memory trials. Still, these data suggest that enhancing GluN2B subunit expression in the aged hippocampus could be more beneficial to memory than harmful. In addition, the results of this study suggest that enhancing GluN2B subunit expression in different brain regions may improve memory at different phases of learning. Therefore, therapies that enhance GluN2B subunit expression throughout the aged brain could help ameliorate age-related memory loss. The first two studies demonstrated that enhancing the expression of the GluN2B subunit within either the frontal lobe or hippocampus of the aged brain has the potential to reduce age-related memory declines. However, the increase was not global nor specific to the synapse. Therefore, a third study was developed with the intent of garnering a more global increase in GluN2B subunit expression that was localized to the synapse. Cyclin dependent kinase 5 (Cdk5) enhances endocytosis of the GluN2B subunit-containing NMDA receptors from the synapse. Previous research has shown that inhibiting Cdk5 increases the number of GluN2B subunits at the synapse and within the whole cell and improves memory in young mice. This study was designed to determine if using antisense phosphorodiamidate morpholino oligomers (Morpholinos) to decrease the expression of Cdk5 protein within the brain would improve memory in aged mice. Morpholinos were conjugated to a cell penetrating peptide, which enhances cellular uptake, and delivered bilaterally to the lateral ventricles of both young and aged mice via acute stereotaxic injection. Treatments consisted of equivalent volumes and concentrations of either vehicle, control Morpholino or a Morpholino targeting the mRNA of Cdk5 (Cdk5 Morpholino). Memory was evaluated in the Morris water maze and using a novel object recognition task. Aged mice treated with the Cdk5 Morpholino exhibited improved early acquisition and spatial bias in the long-term spatial memory trials, as well as improved performance overall, compared to control Morpholino-treated aged animals. However, aged mice treated with the Cdk5 Morpholino performed similarly to vehicle-treated aged animals. The presence of the peptide-conjugated Morpholinos within the brain may have worsened performance in the Morris water maze task since control Morpholino-treated animals performed significantly worse than vehicle-treated animals. In concurrence, there was significantly greater gliosis in peptide-conjugated Morpholino-treated animals over vehicle-treated brains, suggesting it was neurotoxic. In contrast, young mice treated with the Cdk5 Morpholino showed impaired early acquisition and spatial bias but a trend for improved later learning in the long-term spatial memory task compared to control Morpholino-treated animals. Treatment with the Cdk5 Morpholino had no significant effect on cognitive flexibility, associative memory or novel object recognition for young or aged animals. Immunohistochemistry revealed increased GluN2B subunit expression within cells with characteristics of neurons and astroglia in regions of the frontal lobe, caudate nucleus and hippocampus of aged mice who received the Cdk5 Morpholino compared to control treatments. However, the increased GluN2B subunit expression appeared to be greater within the hippocampus. These results suggest that inhibiting the translation of Cdk5 using Morpholinos increased GluN2B subunit expression in both young and aged mice and may have contributed to the improved long-term spatial memory observed in aged mice, despite the Morpholino being administered at a presumably toxic concentration. An additional group of mice was used to determine a non-neurotoxic dosage of the peptide conjugated Morpholino. However, future studies are needed to determine the efficacy of the Cdk5 Morpholino at this dosage. Taken together, the studies presented here suggest that increasing expression of the GluN2B subunit within the aged brain does improve age-associated memory declines. In addition, cell penetrating peptide- conjugated Morpholinos show promise as tools for genetic manipulation within the brain and Cdk5 could prove to be a novel target for enhancing GluN2B subunit expression within the aged brain. Though future studies are needed, the studies presented here do suggest that therapies that enhance GluN2B subunit expression within the aged brain have the potential to help ameliorate memory loss. However, since enhanced GluN2B subunit expression itself can increase the potential for excitotoxicity, an optimal dose of such a therapeutic would need to be determined. / Graduation date: 2013

Graduation date: 1994

Graduation date: 1994

Moï³¥ H. Goldstein, Jr. / "February 19, 1957." Based on a thesis, M.I.T. Dept. of Electrical Engineering, January 9, 1957. / Bibliography: p. 70-73. / Army Signal Corps Contract DA36-039-sc-64637. Dept. of the Army Task 3-99-06-108 and Project 3-99-00-100.

This investigation examined the influence of two levels of dietary sodium (Na+) intake on intramuscular and extracellular potassium (K+) content. Nine unacclimatized college males exercised. (90 minutes of treadmill walking, 5.6km/hr, 6X grade) in an environmental chamber maintained at 40.1( + .05)°C and 23.5( + . 4) %RH, during two 8-day dietary-acclimation regimens. The first regimen employed a high Na+ diet (399mEq/day), the second a low Na+ diet (98mEq/day); both diets contained 80mEq K+/day. Total body K+ stores increased during the high Na+ diet (+138mEq, 4.1%) and the-low Na+ diet (+114mEq, 3.4%). By day 8 (D8) of both treatments, subjects exhibited a significantly lower (p<.O5) mean heart rate and rectal temperature. Oxygen consumption and sweat rate were unaltered but sweat responsiveness (ml/hr/°c) progressively increased during the acclimation trials. Plasma volume increased +16.3% (D4) and +10.7% (D8) under the high Na+ diet and only +3.0% (D4) and +7.0% (D8) under the low Na+ diet. The low sodium diet was associated with a significantly higher (p<.05) mean heart rate (D3-D5), higher rectal temperature (D3-D6), lower sweat responsiveness (D2) and a delayed plasma volume expansion (D4)--resulting in less effective heat removal. The total content of K+, Na+, and C1- in plasma changed isoosmotically with plasma volume. The diets were associated with equivalent urine K+ excretion, and. during exercise in the heat both diets resulted in significantly decreased urine K+ losses. Muscle K+ and sweat K+ concentrations were not altered by dietary intervention or acclimation trials. Total muscle water-was significantly increased, in accord with Na+ and Cl- increases, on D8 of the low Na+ diet only. It was concluded that dietary intake of Na+, in combination with 8 days. of exercise in the heat and heavy sweating, does not significantly diminish the intramuscular K+ or total body K+ content.

Metabolic syndrome (MetS) and abdominal obesity (AbOb) increase the risk of developing cardiovascular disease and diabetes. Energy restriction (ER), highprotein (PRO) intake and high-intensity interval training (HIT) can independently improve MetS and AbOb. However, ER reduces metabolically active lean body mass (LBM) in addition to body fat (BF). Purpose: To determine the effects of a 16-wk ER diet with 2 levels of PRO (15% or 25% of energy), plus HIT, on MetS risk factors, AbOb, and body composition in women. Methods: Sedentary, premenopausal women (age=35±10y) with AbOb (waist circumference [WC] ≥80cm) were randomized to a 16-wk ER diet (-300kcals/d) with 15% (15PRO; n=17) or 25% (25PRO; n=18) of energy from PRO, plus 45min/d, 3d/wk HIT and 45min/d, 2d/wk continuous moderate-intensity exercise (CME) (-200kcals/d). Diet and physical activity (PA) were assessed using 4-d weighed food and PA records, respectively; diet and exercise compliance were assessed monthly with multiple-pass 24-h recalls and weekly tracking logs. Body weight (BW), WC, DXA-assessed body composition (BF [%], BF [kg], trunk fat [kg], and LBM [kg]), blood lipids (total cholesterol [TC], high-density lipoprotein cholesterol [HDL-C], low-density lipoprotein cholesterol [LDL-C], triglycerides [TG]), glycemic markers (fasting plasma glucose [FPG], insulin, and homeostatic model assessment for insulin resistance [HOMA-IR], beta cell function [HOMA-%β] and insulin sensitivity [HOMA-%S]) and resting blood pressure (BP) (systolic BP [SBP]; diastolic BP [DBP]) were assessed pre/post-intervention. Repeated measures analysis of variance and two sample t-tests were used at analyze the date. Results are reported as means±standard deviations. Results: There were significant time, but not group, differences in BW (-5.1±2.6kg, p=0.0141), WC (- 7.3±3.6cm, p<0.0001), TC (-18.1±17.4mg/dL, p<0.0001), LDL-C (12.2± 16.2mg/dL, p<0.0001), TG (-25.3±56.2mg/dL, p=0.0064), insulin (-2.1±4.2mg/dL, p=0.0048), HOMA-IR (-0.2±0.5, p=0.0062), HOMA-%β (-12.1±35.2%, p=0.0497), HOMA-%S (28.5±78.4%, p=0.0357), and SBP (-3±9mmHg, p=0.214). There were significant group x time differences in DBP (15PRO=-5±8mmHg, 25PRO=- 2±8mmHg; p=0.0024). There were no time or group differences in FPG or HDLC. There were significant time, but not group, effects on changes in BW (-5.1kg± 2.6, p<0.0001), BF (-3.3±1.6%, p<0.0001), and LBM (-0.6kg±1.5, p=0.0283). The 15PRO group lost more absolute whole BF (-5.2kg vs. -3.9kg, p=0.0355) and trunk fat (-3.1kg vs. -2.2kg) vs. the 25PRO group. Conclusion: Both diets significantly improved BW, AbOb, MetS risk factors, glycemic control, and BF (%); LBM (kg) loss was similar in both groups. Compared to the 15PRO diet had significantly greater absolute BF-kg and trunk fat-kg losses. Increased PRO intake did not improve AbOb or MetS risk beyond ER and HIT/CME. The impact of HIT/CME and the greater (-1.3kg) changes in BW in the 15PRO group may have contributed significantly to the changes in absolute BF and trunk fat. More research is needed to separate the impact of HIT/CME and weight loss from the impact of PRO during ER. / Graduation date: 2013 / Access restricted to the OSU Community at author's request from March 28, 2013 - March 28, 2014

The purpose of this study was to compare the myocardial structure and function among endurance athletes (n.12), powerlifters/steroid users (n=5), powerlifters/non-steroid users (n=6), and sedentary controls (n=4). All subjects had a M-mode echocardiographic examination of their left ventricles under resting conditions. The echocardiographic measurements recorded and analyzed were of the left ventricular posterior wall at diastole and systole, left ventricular internal diameter at diastole and systole, and inter-ventricular septal thickness at diastole and systole. Myocardial function measurements consisting of left ventricle ejection time, left ventricular mass, mean ventricular contractile force, and percent fractional shortening were also recorded and analyzed. A One Way Analysis of Variance was used to analyze the data for statistical significance. A Tukey's HSD post-hoc test was used to determine statistical significance between the groups. A significant difference (p =0.02) was found for inter-ventricular septal thickness during diastole. All three athletic groups had significantly thicker inter-ventricular septa' thickness during diastole as compared to the controls. Power lifters/steroid users had the thickest inter-ventricular septal thickness (18.7 mm), followed by endurance athletes (18.6 mm), and powerlifters/nonsteroid users (16.5 mm). Overall, powerlifters/steroid users had the thickest walls at systole and diastole, while endurance athletes had the greatest internal diameters relative to the size of the left ventricle. Statistically significant differences among the groups were found for all four myocardial functional parameters: left ventricular ejection time (p = 0.03), left ventricular mass (p = 0.002), mean ventricular contractile force of (p 0.0013), and percent fractional shortening (p = 0.05). Power lifters/steroid users had the fastest left ventricular ejection times, largest left ventricular mass, greatest mean ventricular contractile force, and greatest percent fractional shortening. Endurance athletes had the slowest left ventricular ejection times, second largest left ventricular mass, lowest mean ventricular contractile force, and third lowest percent fractional shortening. The results indicated that not all individuals participating in high level endurance or powerlifting training and competition demonstrated complete adaptations in myocardial structure and function. Power lifters/steroid users however, demonstrated myocardial functional adaptations that were significantly different from powerlifters/non-steroid users, endurance athletes, and controls. The results of this study cannot attribute these changes either to the use of large amounts of anabolic steroids, or long-term, high-intensity training and competition in powerlifting. However, the study identified alterations in myocardial functions in powerlifters/steroid users, and contributes to the existing body of knowledge regarding the use of anabolic steroids by athletes. / Graduation date: 1990