East Carolina University : Research and Creative Achievement Week 2011
Interestingly, little work has been done in multicellular organisms with regards to DNA Polymerase ´. Using two novel mutant fly strains along with cell culture, we show that mutations in DNA Polymerase ´ have effects on genome stability. The work employs a three-pronged approach consisting of an interaction analysis, a genetic analysis and a knockdown analysis in tissue culture.
The Effects of Velocity Change on Lower Extremity Work During the Stance Phase of Running, Olivia Ratcliff, Department of Exercise and Sport Science, East Carolina University, Greenville, NC 27858 Most positive work occurs during the propulsion phase of running while most negative work occurs during the braking phase. Individual joints of the lower extremities contribute to total positive and negative work. When running velocity is changed, there is likely a change in the amount of negative and positive work as well as a shift in the role of the individual joints. The purpose of this study is to determine the positive and negative work for the ankle, knee, and hip and their change during acceleration, deceleration or steady state running. METHODS: Three-dimensional motion analysis was performed on 5 physically active subjects running in 3 conditions: acceleration, deceleration and steady state. Kinematic data were collected with a 9-camera motion analysis system. Ground reaction force was collected with 2 force plates and these data were used to verify the conditions of speed and foot strike pattern. All subjects were rearfoot strikers. 3D joint kinematics and kinetics were calculated and joint work was derived from sagittal plane power data for the ankle, knee and hip. Total work was analyzed using a single factor ANOVA (p= 0.05) to determine differences between conditions for positive and negative work. Individual joint contributions to total work in each condition were also compared. RESULTS: No differences were found between speed conditions within total positive or negative work. For positive work, the ankle contributed the highest percentage (49.8%) followed by the hip (35.1%) and finally the knee (15.1%) with no difference seen between conditions. Statistically significant differences (p< 0.05) were observed for individual contributions to total negative work at the ankle and knee. For negative work, the ankle had the largest contribution during acceleration (58.6%) and steady state (47.5%) while the knee had the greatest contribution during deceleration (46.9%). There was no difference in negative work between conditions at the hip. DISCUSSION: Total work in the lower extremities during stance phase of running does not appear to be influenced by changes in velocity. However, individual joint contributions to negative work are influenced by acceleration or deceleration. The increase in knee work recorded for decelerating may have implications for training or injury risk in athletes.
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