Correlations Between Shoulder Rotational Motion, Strength Measures and Throwing Biomechanics in Collegiate Baseball Pitchers

Pitching involves high stresses to the arm that may alter soft tissue responsible for controlling biomechanics. It has been hypothesized that imbalances in strength and flexibility of the dominant shoulder lead to decreased performance and increased injury risk, but it is not fully known what specific pitching biomechanics are altered. There is a critical need to determine correlations between shoulder rotational strength, range of motion and pitching kinetics. Without such knowledge, identifying potential for injury from shoulder imbalances will likely remain difficult and invasive. The goal of this study was to determine correlations between shoulder rotational strength and range of motion and kinetics. Twelve collegiate pitchers participated in this IRB approved study. The clinical measures session tested shoulder rotational range of motion and strength and grip strength. The motion analysis session tested pitching biomechanics. Paired t-tests investigated differences in strength and range of motion between arms. Linear regression was performed to determine correlations between clinical measures, kinetics and pitch velocity. Regression learner neural networks were created to predict pitch velocity and elbow varus torque using clinical measures as inputs. The dominant arm had significantly higher external rotation and total range of motion than the nondominant arm. The nondominant arm normalized external rotation peak torque was significantly greater than the dominant arm at 0˚ external rotation. Correlations were found between elbow varus torque and isometric external/internal rotation ratio, and between shoulder posterior shear force and isokinetic eccentric external rotation/internal rotation ratios. Correlations to velocity included grip strength, concentric external rotation peak torque, isometric internal rotation peak torques, and isometric external rotation peak torques. The neural network accurately predicted velocity, with the standard deviation of the error equal to 2.29 (2.97%). These correlations associate two testing methods to identify injury risk. Increasing external/internal rotation ratios may decrease elbow varus torque and shoulder posterior shear force. Increasing external rotation, internal rotation, and grip strength may lead to velocity gains. Velocity can be predicted using clinical measures and a neural network

Electrical characterization of single-walled carbon nanotubes : leading toward electronic devices

This thesis presents research involving the electrical characterization of single-walled carbon nanotubes produced by the pulsed-laser vaporization technique. Carbon nanotubes were suspended in organic solvents and separated using ultrasonic excitation. The dispersed nanotubes were either physically deposited or spin-deposited onto electrode structures that were prefabricated using standard electron-beam lithography. Atomic force microscopy was used to locate and measure nanotubes that spanned across metal electrodes. Two-probe charge transport measurements were then made on these nanotube samples. The first sample exhibited current rectification, while many other carbon nanotubes were damaged by electrical breakdown. The effect of manipulating a nanotube at the electrode junction is also demonstrated. It was found that a potential barrier could be introduced, changing the I-V response of the nanotube device. Then, p-channel field-effect transistor behavior is shown for an individual single-walled carbon nanotube. Finally, an electrodeposition technique is presented for reducing the large contact resistance between a nanotube and the metal electrodes. This technique decreased the electrode-nanotube contact resistance by a factor of more than six, and maintained the semiconducting behavior of the nanotube. Energy band diagram models are used to try to explain some of the observed electronic properties

CONNECTED AND AUTONOMOUS VEHICLES EFFECTS ON EMERGENCY RESPONSE TIMES

Emergency response times have been shown to be directly correlated with mortality rates of out-of-hospital patients. Studies have been conducted to show the relationship between time and mortality rates until patients receive the proper treatment. With more cardiac arrests and other life threatening illnesses occurring in the United States, more emergency calls will be required as well. As of today, technological advancements have been made to reduce response times, but human factors still require certain procedures, causing delays in the run time and increasing the rate of mortality. Here we show the results of emergency response times with the market penetration of connected and autonomous vehicles. With connected and autonomous vehicles, the average time emergency vehicles spend on the roadways can be significantly decreased. Safety procedures with human drivers can be eliminated, giving the emergency vehicle a proper right-of-way through virtual emergency lanes and removing the need to slow down and avoid vehicles at intersections or during periods of heavy congestion. Our results show a three minute decrease in response time under full market penetration of the technology, reducing the mortality rate and increasing the potential to save lives

Development of leaf shape and vein homologies in five species of the genus Ipomoea (Convolvulaceae)

Angiosperm leaves are extremely variable in form while predominantly maintaining the function of the primary photosynthetic organ of the plant. Changes in leaf form can result from myriad physiological processes which may be influenced by ecology, physical stimuli, phylogeny, or other factors. In studying the development of divergent leaf forms among closely related species, conserved morphological elements may be identified that are not apparent in the mature form. The genus Ipomoea (Convolvulaceae) contains over 600 species and a wide range in leaf shapes. Five species, I. purpurea, I. coccinea, I. sloteri, I. quamoclit, and I. cairica show a range in leaf forms from simple to highly dissected. Leaf development was tracked from initiation to maturity in order to identify how developmental trajectories diverge and what is conserved across species. Cleared leaf samples were analyzed and evidence was found supporting the homology between major vein patterns across species. Using these homologous veins, landmarks were established for morphometric analysis. A Generalized Procrustes Analysis was used on landmark coordinates and suggests, through Principal Components Analysis, that the shape described by major venation is conserved across these species despite major divergences in blade form