Effects of a Dynamic Arm Stabilizer on Varus Elbow Torque, Arm Speed, and Velocity in Collegiate Baseball Players: A Pilot Study

Purpose: The purpose of this study was to assess the effect a dynamic arm stabilizer had on varus elbow torque, arm speed, and throw velocity during baseball throwing. Methods: 8 collegiate baseball players (age= 20 ± 1 years, height= 183.5 ± 6.5 cm, weight= 85.6 ± 7.7 kg) participated in this study. Participants were randomly assigned to throw their first set of 25 throws at 90 feet wearing a dynamic arm stabilizer or throw their second set of 25 throws at 90 feet not wearing a dynamic arm stabilizer. After completing the first set of throws, the participants threw a second set of 25 throws at 90 feet in the opposite condition. Elbow varus torque and arm speed were measured using a wearable inertial measurement unit, and throwing velocity was measured in miles per hour using a handheld radar gun. Pearson’s correlations were performed to determine relationships between varus torque, arm speed, and velocity during activity with and without the dynamic arm stabilizer. Then, paired samples t-tests were performed to determine differences between varus torque, arm speed, and velocity with and without the dynamic arm stabilizer. Results: Significant correlations were found between varus torque and arm speed, varus torque and velocity, and arm speed and velocity when wearing the dynamic arm stabilizer. Other correlations found were between varus torque and velocity, and arm speed and velocity when not wearing the dynamic arm stabilizer. Significant differences were found between throwing with the dynamic arm stabilizer and not wearing the dynamic arm stabilizer in varus torque (stabilizer = 45.80 ± 8.12 Nm, no stabilizer = 51.85 ± 8.87 Nm, p \u3c .001), arm speed (stabilizer = 857.39 ± 59.64 degrees per second, no stabilizer = 876.58 ± 82.74 degrees per second, p \u3c .001), and throwing velocity (stabilizer = 70.95 ± 5.21 mph, no stabilizer = 71.77 ± 5.68 mph, p \u3c .001). Conclusions: Use of a dynamic arm stabilizer results in a decrease in varus elbow torque when throwing on flat ground at 90 feet. The dynamic arm stabilizer also resulted in a decrease in arm speed and throwing velocity when compared to throwing without a dynamic arm stabilizer. Further research is needed to determine the clinical meaningfulness of these findings in order to determine the best application for a dynamic arm stabilizer in baseball players

Spatio-temporal patterns in the Diel Vertical Migration of the Copepod Metridia lucens in the Northeast Atlantic derived from the Continuous Plankton Recorder Survey

The archived data set collected over a 45-yr period (1948-1992) by Continuous Plankton Recorders (CPRs) towed in near-surface waters was used to investigate the diel vertical migration of the copepod Metridia lucens in the northeast Atlantic (47-63?N and 10-30?W). Although the CPR sampling intensity was uniform during the day and the night, M. lucens was caught predominantly in samples collected at night, consistent with a normal diel vertical migration pattern involving movement from greater depth during the day to shallower depths at night. The length of time spent near the surface varied seasonally and was closely correlated (r2 = 0.80) with seasonal change in length of night. The residual variation in length of time spent at the surface was nonrandom, with more time being spent at the surface in spring before the onset of the spring bloom, and less time being spent at the surface in autumn, than that predicted from the length of night at these periods. The timing of this enhanced near-surface occupation in spring varied with latitude, occurring a mean of 3.4 d later per degree of latitude

Electron spin coherence in metallofullerenes: Y, Sc and La@C82

Endohedral fullerenes encapsulating a spin-active atom or ion within a carbon cage offer a route to self-assembled arrays such as spin chains. In the case of metallofullerenes the charge transfer between the atom and the fullerene cage has been thought to limit the electron spin phase coherence time (T2) to the order of a few microseconds. We study electron spin relaxation in several species of metallofullerene as a function of temperature and solvent environment, yielding a maximum T2 in deuterated o-terphenyl greater than 200 microseconds for Y, Sc and La@C82. The mechanisms governing relaxation (T1, T2) arise from metal-cage vibrational modes, spin-orbit coupling and the nuclear spin environment. The T2 times are over 2 orders of magnitude longer than previously reported and consequently make metallofullerenes of interest in areas such as spin-labelling, spintronics and quantum computing.Comment: 5 pages, 4 figure

Effect of Cupping Therapy on Muscle Tenderness in Collegiate Baseball Players Compared to Sham Treatment: A Randomized, Single-Blinded Trial

Purpose: The purpose of this study was to examine the effects of cupping therapy on muscular tenderness in the triceps surae of collegiate baseball players when compared to a control and sham treatment conditions. Methods: 20 collegiate baseball players (age= 22 ± 2 years, height= 186.8 ± 6.9 cm, weight= 88.6 ± 8.5 kg) participated in this study. Subjects were randomly assigned to either the treatment or sham treatment group. A mark was placed 10-cm superior to the musculotendinous junction of the Achilles tendon and the gastrocnemius on both legs. The treatment or sham treatment was then applied over the mark on the right leg for 15-minutes, with the left leg serving as a control. Muscle tenderness was measured in both legs with a handheld algometer at baseline and after treatment. An independent samples t-test was performed to determine differences in changes to muscle tenderness between the cupping therapy and sham cupping therapy groups. Paired samples t-tests were used to determine differences in changes to muscle tenderness between cupping therapy and sham cupping therapy groups and their respective controls. Results: A significant difference in reduction of muscle tenderness was found between the cupping therapy treatment group and the respective control group (treatment = 1.37 ± 0.54, treatment control = 0.5 ± 1.5, p = 0.009). A significant difference in reduction of tenderness was also noted between the cupping therapy treatment group, and the sham cupping therapy treatment group (treatment = 1.37 ± 0.54, sham = -0.37, p \u3c 0.001). Conclusion: A single 15-minute cupping therapy treatment can decrease muscle tenderness at the triceps surae when compared to both a control and sham treatment condition. These findings are in keeping with previous studies, with the added benefit of attempting to control for a placebo effect and bias during statistical analysis. Keywords: Cupping Therapy, Myofascial Decompression, Muscle Tenderness, Algometr

Bordetella petrii Clinical Isolate

We describe the first clinical isolate of Bordetella petrii from a patient with mandibular osteomyelitis. The only previously documented isolation of B. petrii occurred after the initial culture of a single strain from an environmental source

Social Aggregation in Pea Aphids: Experiment and Random Walk Modeling

From bird flocks to fish schools and ungulate herds to insect swarms, social biological aggregations are found across the natural world. An ongoing challenge in the mathematical modeling of aggregations is to strengthen the connection between models and biological data by quantifying the rules that individuals follow. We model aggregation of the pea aphid, Acyrthosiphon pisum. Specifically, we conduct experiments to track the motion of aphids walking in a featureless circular arena in order to deduce individual-level rules. We observe that each aphid transitions stochastically between a moving and a stationary state. Moving aphids follow a correlated random walk. The probabilities of motion state transitions, as well as the random walk parameters, depend strongly on distance to an aphid\u27s nearest neighbor. For large nearest neighbor distances, when an aphid is essentially isolated, its motion is ballistic with aphids moving faster, turning less, and being less likely to stop. In contrast, for short nearest neighbor distances, aphids move more slowly, turn more, and are more likely to become stationary; this behavior constitutes an aggregation mechanism. From the experimental data, we estimate the state transition probabilities and correlated random walk parameters as a function of nearest neighbor distance. With the individual-level model established, we assess whether it reproduces the macroscopic patterns of movement at the group level. To do so, we consider three distributions, namely distance to nearest neighbor, angle to nearest neighbor, and percentage of population moving at any given time. For each of these three distributions, we compare our experimental data to the output of numerical simulations of our nearest neighbor model, and of a control model in which aphids do not interact socially. Our stochastic, social nearest neighbor model reproduces salient features of the experimental data that are not captured by the control