1,415 research outputs found
Generating Muscle Driven Arm Movements Using Reinforcement Learning
This project focuses on using Reinforcement Learning to optimize arm dynamics through muscle control for desired trajectories. The goal of this project was to create a tool that can be used to gain a better understanding of the armâs muscles and collect information that is useful in many other disciplines such as biomechanics, anthropology, medicine and robotics. I developed biologically realistic models of primate arm\u27s using Stanfordâs SimTK software, an open-source tool for modeling musculoskeletal structures. I then made use of Differential Dynamic Programming in order to generate novel movements from first principles and optimize motion over a specified trajectory. Lastly, I demonstrated the usefulness of this tool by examining its effectiveness in discovering the consequences of different muscle groups on the optimal behavior policy
A Discrete Version of the Inverse Scattering Problem and the J-matrix Method
The problem of the Hamiltonian matrix in the oscillator and Laguerre basis
construction from the S-matrix is treated in the context of the algebraic
analogue of the Marchenko method.Comment: 11 pages. The Laguerre basis case is adde
Health education for musicians
Context and aims: Many musicians suffer for their art, and health is often compromised during training. The Health Promotion in Schools of Music (HPSM) project has recommended that health education should be included in core curricula, although few such courses have been evaluated to date. The aim of the study was to design, implement and evaluate a compulsory health education course at a UK conservatoire of music.
Methods: The course design was informed by a critical appraisal of the literature on musicians' health problems and their management, existing health education courses for musicians, and the HPSM recommendations. It was delivered by a team of appropriately-qualified tutors over 5 months to 104 first-year undergraduate students, and evaluated by means of questionnaires at the beginning and end of the course. Thirty-three students who had been in their first year the year before the course was introduced served as a control group, completing the questionnaire on one occasion only. Items concerned: hearing and use of hearing protection; primary outcomes including perceived knowledge and importance of the topics taught on the course; and secondary outcomes including physical and psychological health and health-promoting behaviors. The content of the essays written by the first-year students as part of their course assessment served as a guide to the topics they found most interesting and relevant.
Results: Comparatively few respondents reported using hearing protection when practicing alone, although there was some evidence of hearing loss, tinnitus, and hyperacusis. Perceived knowledge of the topics on the course, and awareness of the risks to health associated with performing music, increased, as did self-efficacy; otherwise, there were negative effects on secondary outcomes, and few differences between the intervention and control groups. The topics most frequently covered in students' essays were managing music performance anxiety, and life skills and behavior change techniques.
Conclusion: There is considerable scope for improving music students' physical and psychological health and health-related behaviors through health education, and persuading senior managers, educators and students themselves that health education can contribute to performance enhancement
Estimation of responses of yield and grain protein concentration of malting barley to nitrogen fertiliser using plant nitrogen uptake
The effect of nitrogen application on the grain yield and grain protein concentration of barley was studied in 13 field trials covering a wide range of soil N conditions over 4 years at locations in south-eastern Queensland. The main objectives of the study were to quantify the response of barley to N application rate over a range of environmental conditions, and to explain the response in terms of soil mineral N, total N uptake, and N distribution in the plants. Barley made efficient use of N (60 kg grain/kg N) until grain yield reached 90% of maximum yield. Grain protein concentration did not increase to levels unacceptable for malting purposes until grain yield exceeded 85–90% of maximum yield. Nitrogen harvest index was generally high (above 0·75), and did not decrease until the total N supply exceeded that necessary for maximum grain yield. Rates of application of N for malting barley should be determined on the basis of soil analysis (nitrate-N) to 1 m depth and 90% of expected maximum grain yield, assuming that 17 kg N is taken up per tonne of grain produced. It can further be assumed that the crop makes full use of the nitrate N to 1 m present at planting, provided the soil is moist to 1 m. A framework relating grain yield to total N uptake, N harvest index, and grain N concentration is presented. Further, total N uptake of fertilised barley is related to N uptake without fertiliser, fertiliser application rate, and apparent N recovery. The findings reported here will be useful in the development of barley simulation models and decision support packages that can be used to aid N management
OtherâSacrificing Options
I argue that you can be permitted to discount the interests of your adversaries even though doing so would be impartially suboptimal. This means that, in addition to the kinds of moral options that the literature traditionally recognises, there exist what I call other-sacrificing options. I explore the idea that you cannot discount the interests of your adversaries as much as you can favour the interests of your intimates; if this is correct, then there is an asymmetry between negative partiality toward your adversaries and positive partiality toward your intimates
Carbohydrate, protein and fat metabolism during exercise after oral carnitine supplementation in humans
Twenty non-vegetarian active males were pair-matched and randomly assigned to receive 2 g L-Carnitine L-tartrate (LC).d-1 or placebo for 2 weeks. Subjects exercised for 90 min at 70% O2max following 2 days of a prescribed diet (mean ± SD: 13.6 ± 1.6 MJ, 57% carbohydrate, 15% protein, 26% fat, 2% alcohol) before and after supplementation. Results indicated no change in carbohydrate oxidation, nitrogen excretion, branched-chain amino acid oxidation, or plasma urea during exercise between the beginning and end of supplementation in either group. Following 2 weeks LC supplementation the plasma ammonia response to exercise tended to be suppressed (0 vs. 2wk at 60 min exercise: 97 ± 26 vs. 80 ± 9; and 90 min exercise: 116 ± 47 vs. 87 ± 25 ”mol.L-1), with no change in the placebo group. The data indicate that 2 weeks of LC supplementation does not affect fat, carbohydrate and protein contribution to metabolism during prolonged moderate intensity cycling exercise. However, the tendency towards suppressed ammonia accumulation indicates that oral LC supplementation may have the potential to reduce the metabolic stress of exercise or alter ammonia production/removal which warrants further investigation
Effects of exercise intensity and altered substrate availability on cardiovascular and metabolic responses to exercise after oral carnitine supplementation in athletes
The effects of 15 d of supplementation with L-carnitine L-tartrate (LC) on metabolic responses to graded-intensity exercise under conditions of altered substrate availability were examined. Fifteen endurance-trained male athletes undertook exercise trials after a 2-d high-carbohydrate diet (60% CHO, 25% fat) at baseline (D0), on Day 14 (D14), and after a single day of high fat intake (15% CHO, 70% fat) on Day 15 (D15) in a double-blind, placebo-controlled, pair-matched design. Treatment consisted of 3 g LC (2 g L-carnitine/d; n = 8) or placebo (P, n = 7) for 15 d. Exercise trials consisted of 80 min of continuous cycling comprising 20-min periods at each of 20%, 40%, 60%, and 80% VO2peak. There was no significant difference between whole-body rates of CHO and fat oxidation at any workload between D0 and D14 trials for either the P or LC group. Both groups displayed increased fat and reduced carbohydrate oxidation between the D14 and D15 trials (p less than .05). During the D15 trial, heart rate (p less than .05 for 20%, 40%, and 60% workloads) and blood glucose concentration (p less than .05 for 40% and 60% workloads) were lower during exercise in the LC group than in P. These responses suggest that LC may induce subtle changes in substrate handling in metabolically active tissues when fatty-acid availability is increased, but it does not affect whole-body substrate utilization during short-duration exercise at the intensities studied
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