A distributed control microprocessor system

Imperial Users onl

53rd Annual Meeting of the Society for Research into Hydrocephalus and Spina Bifida

RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.Published versio

Larval dispersion along a straight coast with tidal currents: Complex distribution patterns from a simple model

Copyright © 1995 Inter-Research.The majority of marine species have a complex life cycle where the adult phase is preceded by a pelagic larval phase. The dynamics of the more obvious adult phase may be strongly influenced by the distribution and abundance of larvae. Field experiments have been unable to give a complete picture of the spatial-temporal dynamics of the larval phase. This is due to the extremely small size of the individual larvae and the environment in which they live. Here we present a mathematical model of the dispersal of larvae into a region consisting of a straight coastline and a current dominated by tidal effects. Spawning is near the coast from a well-defined site the size of a small jetty or reef and the larvae have a relatively short pelagic lifetime. The model is based on the advection-diffusion-mortality equation. Using a new analytic solution to the model, we examine the effect of processes such as the current structure, mortality, and the duration and rate at which larvae are released, on dispersal. The model is relatively simple but produces surprisingly complex patterns of dispersal. This has implications for attempts to produce more complex models of dispersal and the way in which field data of larval densities should be interpreted.S. A. Richards, H. P. Possingham, B. J. Noy

Exploring the use of high and low demand simulation for human performance assessment during multiorgan retrieval with the joint scrub practitioner

INTRODUCTION: The National Organ Retrieval Service (NORS) 2015 review recommended a Joint Scrub Practitioner for abdominal and cardiac teams during combined organ retrieval. To evaluate the feasibility of this role, and to understand the functional implications, this study explores the use of simulation and provides a novel and comprehensive approach to assess individual and team performance in simulated multiorgan retrievals. METHODS: Two high-fidelity simulations were conducted in an operating theatre with porcine organs, en bloc, placed in a mannequin. For donation after brainstem death (DBD) simulation, an anaesthetic machine provided simulated physiological output. Retrievals following donation after circulatory death (DCD) began with rapid arrival in theatre of the mannequin. Cardiothoracic (lead surgeon) and abdominal (lead and assistant surgeons; joint scrub practitioner, n=9) teams combined for the retrievals. Data collected before, during and after simulations used self-report and expert observers to assess: attitudinal expectations, mental readiness, mental effort, non-technical skills, teamwork, task workload and social validation perceptions. RESULTS: Attitudinal changes regarding feasibility of a joint scrub practitioner for DBD and DCD are displayed in the main body. There were no significant differences in mental readiness prior to simulations nor in mental effort indicated afterwards; however, variance was noted between simulations for individual team members. Non-technical skills were slightly lower in DCD than in DBD. Global ratings of teamwork were significantly (p<0.05) lower in DCD than in DBD. Measures of attitude indicated less support for the proposed joint scrub practitioner role for DCD than for DBD. DISCUSSION: The paper posits that the joint scrub practitioner role in DCD multiorgan retrieval may bring serious and unanticipated challenges. Further work to determine the feasibility of the NORS recommendation is required. Measures of team performance and individual psychological response can inform organ retrieval feasibility considerations nationally and internationally