Comparison of simple gravity based accelerometer calibration procedures

Accelerometers are commonly used, yet the process of calibrating them and the influence this has on recorded accelerations is rarely reported. The aim of this study was to compare the accuracy of three simple gravity based calibration methods of accelerometers. Using a custom made rig, 16 Delsys Trigno sensors were simultaneously calibrated by positioning the sensors in 9 positions throughout the full range of orientations across three axes. Three calibration methods were used spanning a range of 1g (1G), 2g (2G), and 2g with optimisation (2Gopt). Errors were greatest in 1G (RMSD=3.1%) and equally as good for the 2G and 2Gopt (2.1%). Gravity based calibration of accelerometers can be achieved quickly, and calibration over a larger range provides more accurate results. This work provides recommendations of accelerometer use which help the applied practitioner to collect more reliable and valid data. Further investigation of factors, including those affecting the frequency of calibration, is required

MANIPULATION OF THE KINEMATIC CHAlN USING VISUAL BIOFEEDBACK

Feedback has been shown to be an influential component in skill development, yet this has not been assessed in movements involving an explosive proximal to distal sequencing pattern. Novices (n=14) were introduced to a lunge touch task. Visual biofeedback were given on the timing and magnitude of rear leg kinematics. Results showed that those who received feedback adapted their movement patterns by developing extension velocity magnitudes in a summative pattern (pre v post, mean f SD peak ankle angular velocity: biofeedback; 479 * 181 v 889 k 11 7, control; 468 k 106 v 477 f 84 deg.s7), resulting in greater horizontal impulse (mean ? SD: biofeedback; 1.17 ? 0.60 v 1.7 & 0.89, control; 1.33 & 0.33 v 1-48? 0.33 M-s-kg7). The changes were retained after six weeks. These results demonstrate that knowledge of performance based biofeedback interventions alone are effective in developing whole limb contributions in an explosive task

Arkansas Soybean Performance Tests 2022

Soybean variety and strain performance tests are conducted each year in Arkansas by the University of Arkansas System Division of Agriculture’s Arkansas Crop Variety Improvement Program. The tests provide information to companies developing varieties and/ or marketing seed within the state, and aid the Arkansas Cooperative Extension Service in formulating variety recommendations for soybean producers

Arkansas Wheat Performance Tests 2022-2023

Wheat variety performance tests are conducted each year in Arkansas by the University of Arkansas System Division of Agriculture’s Arkansas Crop Variety Improvement Program. The tests provide information to companies developing cultivars and marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating variety recommendations for small-grain producers. The tests were conducted at the Northeast Research and Extension Center at Keiser, the Vegetable Substation near Kibler, the Lon Mann Cotton Research Station near Marianna, the Pine Tree Research Station near Colt, and the Rohwer Research Station near Rohwer. Specific location and cultural practice information accompany each table

LONGITUDINAL MANIPULATUION OF THE KINEMATIC CHAIN USING A REDUCING BIOFEEDBACK SCHEDULE

Feedback has been shown to be an influential component in skill development, yet this has not been assessed longitudinally in a complex motor skill. Novices (n=32) were introduced to a lunge touch task. Visual biofeedback were given on the timing and magnitude of rear leg kinematics. Results showed that those who received feedback adapted their movement patterns by developing extension velocity magnitudes (40.0%, 24.8% and 28.9% increases for the hip, knee and ankle respectively). The changes were retained across 26 weeks, with a reducing visit schedule of feedback. These results demonstrate that knowledge of performance based biofeedback interventions alone are effective in developing whole limb contributions in an explosive task, and that a reducing visit schedule negates dependence on feedback

Arkansas Corn and Grain Sorghum Performance Tests 2022

Corn and grain sorghum performance tests are conducted each year in Arkansas by the University of Arkansas System Division of Agriculture. The tests provide information to companies marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating recommendations for producers. The 2022 corn performance tests contained 68 hybrids and were conducted at the Northeast Rice Research and Extension Center (NERREC) at Harrisburg, the Northeast Rice Research and Extension Center (NEREC) at Keiser, the Lon Mann Cotton Research Station (LMCRS) near Marianna, the Rohwer Research Station (RRS) near Rohwer, and the Rice Research and Extension Center (RREC) near Stuttgart. The 2022 grain sorghum performance tests contained 24 hybrids and were conducted at the NERREC, the NEREC, the LMCRS, the RRS, and the RREC locations. The test location map for grain sorghum and corn can be found on page 42

Arkansas Corn and Grain Sorghum Performance Tests 2022

Corn and grain sorghum performance tests are conducted each year in Arkansas by the University of Arkansas System Division of Agriculture. The tests provide information to companies marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating recommendations for producers. The 2022 corn performance tests contained 68 hybrids and were conducted at the Northeast Rice Research and Extension Center (NERREC) at Harrisburg, the Northeast Rice Research and Extension Center (NEREC) at Keiser, the Lon Mann Cotton Research Station (LMCRS) near Marianna, the Rohwer Research Station (RRS) near Rohwer, and the Rice Research and Extension Center (RREC) near Stuttgart. The 2022 grain sorghum performance tests contained 24 hybrids and were conducted at the NERREC, the NEREC, the LMCRS, the RRS, and the RREC locations. The test location map for grain sorghum and corn can be found on page 42

Arkansas Soybean Performance Tests 2022

Soybean variety and strain performance tests are conducted each year in Arkansas by the University of Arkansas System Division of Agriculture’s Arkansas Crop Variety Improvement Program. The tests provide information to companies developing varieties and/ or marketing seed within the state, and aid the Arkansas Cooperative Extension Service in formulating variety recommendations for soybean producers