Definition of a Novel Pathway Centered on Lysophosphatidic Acid To Recruit Monocytes during the Resolution Phase of Tissue Inflammation.

Blood-derived monocytes remove apoptotic cells and terminate inflammation in settings as diverse as atherosclerosis and Alzheimer's disease. They express high levels of the proresolving receptor ALX/FPR2, which is activated by the protein annexin A1 (ANXA1), found in high abundance in inflammatory exudates. Using primary human blood monocytes from healthy donors, we identified ANXA1 as a potent CD14+CD16- monocyte chemoattractant, acting via ALX/FPR2. Downstream signaling pathway analysis revealed the p38 MAPK-mediated activation of a calcium independent phospholipase A2 with resultant synthesis of lysophosphatidic acid (LPA) driving chemotaxis through LPA receptor 2 and actin cytoskeletal mobilization. In vivo experiments confirmed ANXA1 as an independent phospholipase A2-dependent monocyte recruiter; congruently, monocyte recruitment was significantly impaired during ongoing zymosan-induced inflammation in AnxA1-/- or alx/fpr2/3-/- mice. Using a dorsal air-pouch model, passive transfer of apoptotic neutrophils between AnxA1-/- and wild-type mice identified effete neutrophils as the primary source of soluble ANXA1 in inflammatory resolution. Together, these data elucidate a novel proresolving network centered on ANXA1 and LPA generation and identify previously unappreciated determinants of ANXA1 and ALX/FPR2 signaling in monocytes

MLB Statcast Pitch Analysis: the Association between Active Spin and Opponent’s Batting Average

Baseball has often been described as a game of statistics and strategy, and current technology allows detailed examination of the game. One statistic measured concerning the movement of the ball is spin rate, the rotations per minute created by the pitcher when the ball is released from the hand. However, recent research has not examined the inclusion of pitchers’ spin rate in batter strategy. PURPOSE: The purpose of this study is to see if there is an association between the movement of breaking balls with the batting average of Major League Baseball batters. METHODS: A sample including 76 elite Major League Baseball pitchers, all male (age = 30.12 ± 3.68, mean ± sd), were taken from the 2019 MLB regular season using Statcast, Pitch F/x, and Trackman cameras. Statcast is used in Major League Baseball and collects the pitcher’s data revolving around their pitches (e.g., active spin, speed, whiff). Pitchers who had thrown a minimum of 2,500 pitches were included. The outcome was batting average, an aggregate number based on the number of players who faced an individual pitcher during the season. We performed multivariable linear regression models to regress batting average on curveballs and sliders separately. Covariates for assessment included pitcher demographics, active movement of the pitch, spin rate of the pitch, hits, at bats, percent of breaking balls thrown, pitch velocity, and number thrown versus right- and left-handed batters. RESULTS: After regression assumptions and steps were satisfied, 43.7% of the variation in batting average could be accounted for by the active spin of the slider, the number of sliders thrown, pitching hand, and the pitcher’s height. For every one-unit increase in active spin of the slider, batting average significantly decreased by 0.0013. Concerning curveballs, regression steps yielded a single-variable model, where 13.1% of the variation in batting average could be explained by the number of curveballs thrown. For every one-unit increase in the number of curveballs thrown, batting average significantly decreased by 0.00013. CONCLUSION: Variables significantly associated with batting average varied by whether a slider or a curveball was thrown; an increase in spin rate was significantly associated with a decrease in batting average for sliders thrown, but not for curveballs. The results of this study can be used by coaches as they prepare for games to enable the most favorable matchup between batter and pitcher. Future research should expand the timeline to include multiple MLB seasons to further corroborate these findings

Monte Carlo Simulations for the Magnetic Phase Diagram of the Double Exchange Hamiltonian

We have used Monte Carlo simulation techniques to obtain the magnetic phase diagram of the double exchange Hamiltonian. We have found that the Berry's phase of the hopping amplitude has a negligible effect in the value of the magnetic critical temperature. To avoid finite size problems in our simulations we have also developed an approximated expression for the double exchange energy. This allows us to obtain the critical temperature for the ferromagnetic to paramagnetic transition more accurately. In our calculations we do not observe any strange behavior in the kinetic energy, chemical potential or electron density of states near the magnetic critical temperature. Therefore, we conclude that other effects, not included in the double exchange Hamiltonian, are needed to understand the metal-insulator transition which occurs in the manganites.Comment: 6 pages Revtex, 8 PS figure

Differences in Frontal Plane Knee Kinematics by Grip, Load, and Concentric Subphase in the Front Squat

Although the back squat is one of few exercises that has been extensively analyzed, the body of literature examining its counterpart, the front squat, is not as robust. The front squat is a vital exercise known for its quadricep development capabilities and unique front-rack positioning. This grip position renders the front squat more difficult, and thus proper form is more vital to prevent injury. PURPOSE: To evaluate the association between grip (standard front-rack, cross-grip, and strap-assisted), load (50% and 80% of 1-RM), and subphases of the concentric portion of the squat on frontal plane knee varus and valgus movement in the front squat. METHODS: Data was gathered from eight participants. Inclusion criteria were at least 60% on the Lower Extremity Functional Scale, self-report of performing front squats at least every two weeks for the past six months, and squatting below parallel. Two sessions were completed. First, consent, anthropometrics, and a 1-RM were obtained. Next, each subject was randomized to perform four repetitions of each grip at 50% and 80% of their 1-RM. During this session, a 29-marker set for 3D motion capture was used to collect joint angle data for each squat. We used data from knee frontal plane angles to analyze the concentric portion of the squat which we broke into subphases (1: 25%, 2: 50%, 3: 75% and 4: 100%) by frame. Only the second repetition from the left leg was analyzed. We performed a three-way repeated measures ANOVA for within-subject factors of grip technique (front-rack, cross-grip, strap-assisted), load (50%, 80%), and sub-phase of the concentric part of the squat (1, 2, 3, 4). We performed a sensitivity analysis with data from the second repetition of the right leg. Analyses were performed using R, version 4.0.3. Significance was set at p\u3c0.05. RESULTS: The eight participants (6 males, 2 females) were 173.10 ± 8.00cm (mean ± sd) in height, 78.20 ± 12.30kg in mass, 25 ± 3yrs of age, reported 6 ± 4 yrs of training experience, and had a 1-RM of 114.10 ± 31.00kg. There were no significant main effects for grip or load on knee varus/valgus movement in the frontal plane. However, there was a significant main effect for subphases of the concentric portion of the squat (p\u3c0.001). Except for between phases 3 and 4, there were significant differences between all pairwise comparisons of phases (p\u3c0.001 for all remaining except between 2 and 3, p = 0.002); whereas varus movement was found in phase 1, valgus movement was found in phase 2. Sensitivity analyses on the right leg yielded similar results. CONCLUSION: Our findings suggest that the subphases of the concentric portion of the front squat, but not grip or load, were significantly associated with varus/valgus movement of the knee. Therefore, strength coaches can choose a grip and load that is most appropriate for the specific athlete without significant impact on varus/valgus movement. However, regardless of grip or load, strength coaches should tune in closely to the concentric subphases of the front squat. In particular, to better prevent injury, strength coaches should focus on the first and second subphases phases where significant frontal plane movement may occur

A globally efficient means of distributing UTC time and frequency through GPS

Time and frequency outputs comparable in quality to the best laboratories have been demonstrated on an integrated system suitable for field application on a global basis. The system measures the time difference between 1 pulse-per-second (pps) signals derived from local primary frequency standards and from a multi-channel GPS C/A receiver. The measured data is processed through optimal SA Filter algorithms that enhance both the stability and accuracy of GPS timing signals. Experiments were run simultaneously at four different sites. Even with large distances between sites, the overall results show a high degree of cross-correlation of the SA noise. With sufficiently long simultaneous measurement sequences, the data shows that determination of the difference in local frequency from an accepted remote standard to better than 1 x 10(exp -14) is possible. This method yields frequency accuracy, stability, and timing stability comparable to that obtained with more conventional common-view experiments. In addition, this approach provides UTC(USNO MC) in real time to an accuracy better than 20 ns without the problems normally associated with conventional common-view techniques. An experimental tracking loop was also set up to demonstrate the use of enhanced GPS for dissemination of UTC(USNO MC) over a wide geographic area. Properly disciplining a cesium standard with a multi-channel GPS receiver, with additional input from USNO, has been found to permit maintaining a timing precision of better than 10 ns between Palo Alto, CA and Washington, DC

Endogenous annexin A1 is a novel protective determinant in nonalcoholic steatohepatitis in mice

Macrophage-derived AnxA1 plays a functional role in modulating hepatic inflammation and fibrogenesis during NASH progression, suggesting the possible use of AnxA1 analogs for therapeutic control of this disease

Conductance as a Function of the Temperature in the Double Exchange Model

We have used the Kubo formula to calculate the temperature dependence of the electrical conductance of the double exchange Hamiltonian. We average the conductance over an statistical ensemble of clusters, which are obtained by performing Monte Carlo simulations on the classical spin orientation of the double exchange Hamiltonian. We find that for electron concentrations bigger than 0.1, the system is metallic at all temperatures. In particular it is not observed any change in the temperature dependence of the resistivity near the magnetical critical temperature. The calculated resistivity near $T_c$ is around ten times smaller than the experimental value. We conclude that the double exchange model is not able to explain the metal to insulator transition which experimentally occurs at temperatures near the magnetic critical temperature.Comment: 6 pages, 5 figures included in the tex

Double Exchange Alone Does Not Explain the Resistivity of La1−xSrxMnO3La_{1-x} Sr_x MnO_3

The $La_{1-x} Sr_x MnO_3$ system with $0.2 \lesssim x \lesssim 0.4$ has traditionally been modelled with a ``double exchange'' Hamiltonian, in which it is assumed that the only relevant physics is the tendency of carrier hopping to line up neighboring spins. We present a solution of the double exchange model, show it is incompatible with many aspects of the resistivity data, and propose that a strong electron-phonon interaction arising from a Jahn-Teller splitting of the outer Mn d-level plays a crucial role.Comment: Figure available via concentional mail. Contact [email protected]

Franck-Condon-Broadened Angle-Resolved Photoemission Spectra Predicted in LaMnO3

The sudden photohole of least energy created in the photoemission process is a vibrationally excited state of a small polaron. Therefore the photoemission spectrum in LaMnO3 is predicted to have multiple Franck-Condon vibrational sidebands. This generates an intrinsic line broadening approximately 0.5 eV. The photoemission spectral function has two peaks whose central energies disperse with band width approximately 1.2 eV. Signatures of these phenomena are predicted to appear in angle-resolved photoemission spectra.Comment: Revtex file 4 pages and 3 figure