COMPARISON OF THE CATCHER’S TRADITIONAL THROW-DOWN VERSUS PITCH-OUT

The catcher is often the defensive leader on the field. With a plethora of assignments to manage during a game, one of the many responsibilities a catcher has is catching base runners that attempt to steal. Catchers throwing out base stealers at second base utilize two methodologies: a traditional throw-down or the pitch-out. The purpose of the study was to explore potential differences in joint kinematics between the two motions when throwing to second base and how performance is affected. Vicon cameras recorded the throwing motions of the catcher, providing data for kinematic analysis. The pitch-out showed higher ball velocities than the traditional throw-down, but similar pop times. Furthermore, elbow extension and trunk angular velocities were significantly different. With knowledge of the throwing kinematics of catchers, performance can be potentially improved and injury avoided

JIGSAW: Efficient and Scalable Path Constraints Fuzzing

Coverage-guided testing has shown to be an effective way to find bugs. If we model coverage-guided testing as a search problem (i.e., finding inputs that can cover more branches), then its efficiency mainly depends on two factors: (1) the accuracy of the searching algorithm and (2) the number of inputs that can be evaluated per unit time. Therefore, improving the search throughput has shown to be an effective way to improve the performance of coverage-guided testing.In this work, we present a novel design to improve the search throughput: by evaluating newly generated inputs with JIT-compiled path constraints. This approach allows us to significantly improve the single thread throughput as well as scaling to multiple cores. We also developed several optimization techniques to eliminate major bottlenecks during this process. Evaluation of our prototype JIGSAW shows that our approach can achieve three orders of magnitude higher search throughput than existing fuzzers and can scale to multiple cores. We also find that with such high throughput, a simple gradient-guided search heuristic can solve path constraints collected from a large set of real-world programs faster than SMT solvers with much more sophisticated search heuristics. Evaluation of end-to-end coverage-guided testing also shows that our JIGSAW-powered hybrid fuzzer can outperform state-of-the-art testing tools

ANALYSIS OF TRUNK ROTATION PATTERNS WHEN SWINGING AT DIFFERENT SPEEDS: A PILOT STUDY

As the trunk plays a vital role during the golf full swing, it is important to understand how body movements affect the golf swing. The purpose of this study was to determine how golfers increase club head speed through trunk rotation. Trunk rotation patterns were captured by 3D motion capture system at 250 Hz. To investigate the effective factors of increasing club head speed, we compared two situations, swing at normal club head speed and at accelerated club head speed, via the trunk rotation angles at three dimensions through six temporary events. The results showed that subtle differences between normal club head speed and accelerated club head speed. To increase club head speed, golfers might optimize the separation between shoulder and pelvic in the early downswing

DISTRIBUTION OF GRIP PRESSURE THROUGHOUT THE PHASES OF PUTTING IN ELITE GOLF COLLEGE PLAYERS

The purpose of this study is to investigate the distribution of grip pressure, force and the peak pressure of different phases during the putting stroke. Five elite college players with handicaps of 2-8 participated in the study. The Novel Pliance-x System and 150Hz 8- camera Motion Analysis Corporation System were used to collect grip pressure and identify each phase of the putting stroke. At each phase of the putting stroke, average grip pressure, peak pressure and grip force were investigated. Results indicated that lowest grip pressure occurred at address up to the top of backswing (2.41±1.36 Kpa). Grip pressure started to increase during the downswing and reached its peak, 0.02±0.05s, before impact (4.70±1.97 Kpa). The pressure reduced again after impact (4.36±2.06 Kpa). Results indicate that grip pressure does not remain the same throughout the stroke

PHYSIOLOGICAL AND ELECTROMYOGRAPHIC RESPONSES AT THREE LEVELS OF BICYCLE SEAT HEIGHT

Recently, bicycle riding has become one of the most popular exercises. As the use time increased, the risk of pedalling injury raised. Holmes (1994) indicated that inappropriate bicycle saddle height could result in lower limbs injuries. The motivation of this study was to find out the best riding position that could effectively use energy from the physiology and electromyography measures. The oxygen consumption (VO2), heart rate (HR), respiratory exchange ratio (RER) and the muscle activity (electromyography, EMG) from rectus femoris (RF) and biceps femoris (BF) of lower limb were collected during a 6 min cycling trail in three different heights of bicycle saddle. The purpose of this study was to compare the effects of three different types of bicycle seat heights and different perspectives of muscle activity and physiology’s parameters

Influences of different developmental periods of taurine supplements on synaptic plasticity in hippocampal CA1 area of rats following prenatal and perinatal lead exposure

<p>Abstract</p> <p>Background</p> <p>Previous study has demonstrated that dietary taurine supplement protected rats from impairments of synaptic plasticity induced by postnatal lead exposure. However, little is known about the role of taurine in the presence of prenatal and perinatal lead exposure. We investigated the possible effect of taurine supplement on prenatal and perinatal lead-induced synaptic plasticity deficit and determined developmental periods critical for the effect of taurine.</p> <p>Results</p> <p>In the present study, taurine was administrated to prenatal and perinatal lead-exposed rats in different developmental periods: from prenatal to weaning (Lead+PW-Tau), from weaning to life (Lead+WL-Tau), and from prenatal to life (Lead+PL-Tau). We examined the input-output (I/O) function, paired-pulse facilitation (PPF) and the long-term potentiation (LTP) of field excitatory postsynaptic potential (fEPSP) in the hippocampal CA1 area of rats on postnatal days 18–25 (P18–25) or days 60–75 (P60–75). We found that (1) on P18–25, taurine had no evident effect on I/O functions and PPF ratios of lead-exposed rats but caused a 12.0% increase in the LTP amplitudes of these animals; (2) on P60–75, taurine significantly elevated lead depressed I/O functions and PPF ratios in Lead+PW-Tau and Lead+PL-Tau rats, but failed in Lead+WL-Tau rats. The amplitudes of LTP of lead-exposed rats were all significantly increased by additional taurine supplement in any developmental period compared with untreated rats. Thus, taurine appeared to have the most effect during the prenatal and lactation periods and its effects on younger rats would not be manifest until the adult life; and (3) the level of lead deposition in hippocampus was evidently reduced by additional treatment of taurine in lead-exposed rats, compared with untreated rats.</p> <p>Conclusion</p> <p>Taurine supplement can protect the adult rats from synaptic plasticity deficits following prenatal and perinatal lead exposure, and the protective effects are critical for the prenatal and lactation periods of lead-exposed rats.</p