Controlling a system with redundant degrees of freedom: transition from standing to walking.

In earlier investigations Lévy and Cruse (J Comp Physiol 194:719-733, 2008; J Comp Physiol 194:735-750, 2008) asked the question that how the nervous system of a stick insect, Carausius morosus, chooses a solution from an abundance of possibilities to solve the task of distributing its body weight onto its six legs, i.e., the torques that are produced by the 18 joints (three per leg). This paper concentrates on the transition from standing to walking using semi-parametrical regression models. Results presented are basically descriptive and do not deal yet with underlying mechanisms. Based on torque changes, the first swing movement is initiated at about 0.3 s before the first leg takes off. The way torques change depends on the joint type, on whether the leg is going to swing and on the number of legs swinging, but not on the leg type, not on the torques size and not on the stepping configuration. Furthermore, the more legs are lifted off to begin a swing movement the higher are the torques produced. The results might be interpreted such that legs starting a swing movement develop, before lift off, levating torques to overcome the adhesive forces produced by the tarsi, whereas the other legs develop depressing torques to maintain the posture.

Service contribution and cost-effectiveness of specialist registrars in NHS trusts: a survey and costing analysis.

Since the introduction of the European Working Time Directive, specialist registrars arguably contribute less to clinical service. The purpose of this study was to broadly quantify the service contribution of specialist registrars across a range of specialties and their value to an NHS organisation. A questionnaire-based survey of the clinical activities of specialist registrars in a large NHS trust was undertaken. Simple costing analyses of this -clinical activity were performed. Responses from 66 specialist registrars in 24 specialties showed an average of 51% overall clinical autonomy. Trainees attended an average of 2.7 outpatient clinics per week and spent 3.5 sessions a week doing ward work. Medical trainees took more referrals and attended more clinics. An analysis of costings suggested that surgical trainees might have generated around £700,000 income per year for the trust. Overall, specialist registrars make a substantial contribution to NHS clinical service and are cost-effective.