Posture flexibility and grip strength in horse riders

Since the ability to train the horse to be ambidextrous is considered highly desirable, rider asymmetry is recognized as a negative trait. Acquired postural and functional asymmetry can originate from numerous anatomical regions, so it is difficult to suggest if any is developed due to riding. The aim of this study was therefore to assess symmetry of posture, strength and flexibility in a large population of riders and to determine whether typical traits exist due to riding. 127 right handed riders from the UK and USA were categorized according to years riding (in 20 year increments) and their competition level (using affiliated test levels). Leg length, grip strength and spinal posture were measured and recorded by a physiotherapist. Standing and sitting posture and trunk flexibility were measured with 3-D motion capture technology. Right-left differences were explored in relation to years riding and rider competitive experience. Significant anatomical asymmetry was found for the difference in standing acromion process height for a competition level (-0.07±1.50 cm Intro/Prelim; 0.02±1.31 cm Novice; 0.43±1.27 cm Elementary+; p=0.048) and for sitting iliac crest height for years riding (-0.23±1.36 cm Intro/Prelim; 0.01±1.50 cm Novice; 0.86±0.41 cm Elementary+;p=0.021). For functional asymmetry, a significant interaction was found for lateral bending ROM for years riding x competition level (p=0.047). The demands on dressage riders competing at higher levels may predispose these riders to a higher risk of developing asymmetry and potentially chronic back pain rather than improving their symmetry

Preliminary results on the 233U capture cross section and alpha ratio measured at n_TOF (CERN) with the fission tagging technique

233U is of key importance among the fissile nuclei in the Th-U fuel cycle. A particularity of 233U is its small neutron capture cross-section, which is on average about one order of magnitude lower than the fission cross-section.The accuracy in the measurement of the 233U capture cross-section depends crucially onan efficient capture-fission discrimination, thus a combined set-up of fission and ¿-detectors is needed. A measurement of the 233U capture cross-section and capture-to-fissionratio was performed at the CERN n_TOF facility. The Total Absorption Calorimeter (TAC) of n_TOF was employed as ¿-detector coupled with a novel compact ionization chamber as fission detector. A brief description of the experimental set-up will be given, and essential parts of the analysis procedure as well as the preliminary response of the set-up to capture are presented and discussedPostprint (published version

Feedback vibration control of a base-isolated building with delayed measurements using h∞ techniques

n this paper we address the problem of vibration reduction of buildings with delayed measurements, where the delays are time-varying and bounded. We focus on a convex optimization approach to the problem of state-feedback H ∞ control design. An appropriate Lyapunov-Krasovskii functional and some free weighting matrices are used to establish some delay-range-dependent sufficient conditions for the design of desired controllers in terms of linear matrix inequalities (LMIs). The controller, which guarantees asymptotic stability and an H ∞ performance, simultaneously, for the closed-loop system of the structure, is then developed. The performance of the controller is evaluated through the simulation of an n-story base-isolated building

Safety culture maturity assessment for mining activities in South America

BACKGROUND:Health and safety is a crucial issue in the mining industry due to the implication of accidents in the sector. OBJECTIVE:This study determines the safety culture characteristics in several mining activities from South America. METHODS:A survey of the safety culture maturity has been done by means of 24 questions regarding the type of activity, number of employees and safety culture characteristics of the activity: information of accidents and incidents, organizational structure to deal with information, involvement of the company in health and safety issues, the way it communicates accidents and incidents and commitment of the company towards health and safety. RESULTS:The questionnaire was completed by 62 managers from Bolivia, Peru and Colombia. Results show different behaviors depending on the type of company, Artisanal or Large-Scale Mines, ASM and LSM respectively. LSM show a level of maturity according to the size of the company, while ASM does not have a clear trend in terms of size, even though there is a relationship between employees and safety culture maturity. In addition, a remarkable difference can be seen between activities with and without continuous improvement systems implemented. CONCLUSIONS:Large scale mining improves their level of safety culture as the size of the company increases, because procedures and control systems are implemented. Cooperatives or small companies also achieve substantial gains when they introduce similar systems