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SUMMARY1. Changes in heart rate and blood pressure were observed, in nine healthy subjects, during and after voluntary and electrically evoked isometric contractions of the triceps surae under conditions of local circulatory arrest.2. The progressive increases in heart rate and blood pressure seen during 2 min voluntary and evoked contractions at 30 % of maximal voluntary contraction were not significantly different in the two conditions. On cessation of contraction but with circulatory arrest maintained, heart rate fell to control levels while blood pressure fell to a similar though still significantly elevated level in both conditions. Elevated blood pressure was maintained for 2 min until the circulatory occlusion was removed; however it was maintained at a significantly higher level for the last 60-90 s of occlusion following electrically evoked contractions compared to voluntary contraction.3. Comparison of the responses to voluntary and involuntary electrically evoked contractions suggest that 'central command' is not necessary for the initial increases in heart rate and blood pressure to occur. In addition the removal of central command on cessation of contraction need not account for the return of heart rate to control levels or the drop in blood pressure at that time. Maintained blood pressure elevation during circulatory occlusion would seem to be due to the trapping of chemical substances within the muscle interstitium.
Learning that transcends participation processes is critical if public engagement is to translate into a legacy of enhanced environmental citizenship. However, a lack of empirical evidence has limited discussion to date to largely 'aspirational' claims. This paper offers the first rigorous examination of whether public participation does generate beyond-process social learning. Initially we review the literature on public participation and environmental citizenship to identify the key dimensions of social learning. We then re-visit a well-worked case study of an innovative public engagement process on the Hampshire waste strategy from the 1990s. Approximately one third of the original participants have been interviewed to identify whether and how the experience had a lasting effect on them. Key methodological difficulties are discussed, not least the analytical difficulties of attributing learning to a process that happened ten years previously. However, we argue that there is evidence that both instrumental and communicative learning have taken place, and conclude by identifying key areas that require further research.social learning, public engagement, deliberation, waste management, environmental citizenship,
Films made from cellulose nitrate LR-115 (Pathé Kodak) and CR-39 have been used for long-term measurements of the radon-222 emanation from building materials and the resultant activity inside houses. The emanation from crushed granite bricks is found to be produced from within the brick while in the clay bricks it originates in the surface layers only. The airborne radon activity inside houses constructed from clay brick is found on average to be 22 mBq 1-1 (0.57 pCi 1-1) while inside a closed vessel sealed to the brick the average equilibrium activity is 40 mBq 1-1 pCi 1-1).
In a recent epidemiological study, Bayesian uncertainties on lung doses have been calculated to determine lung cancer risk from occupational exposures to plutonium. These calculations used a revised version of the Human Respiratory Tract Model (HRTM) published by the ICRP. In addition to the Bayesian analyses, which give probability distributions of doses, point estimates of doses (single estimates without uncertainty) were also provided for that study using the existing HRTM as it is described in ICRP Publication 66; these are to be used in a preliminary analysis of risk. To infer the differences between the point estimates and Bayesian uncertainty analyses, this paper applies the methodology to former workers of the United Kingdom Atomic Energy Authority (UKAEA), who constituted a subset of the study cohort. The resulting probability distributions of lung doses are compared with the point estimates obtained for each worker. It is shown that mean posterior lung doses are around two- to fourfold higher than point estimates and that uncertainties on doses vary over a wide range, greater than two orders of magnitude for some lung tissues. In addition, we demonstrate that uncertainties on the parameter values, rather than the model structure, are largely responsible for these effects. Of these it appears to be the parameters describing absorption from the lungs to blood that have the greatest impact on estimates of lung doses from urine bioassay. Therefore, accurate determination of the chemical form of inhaled plutonium and the absorption parameter values for these materials is important for obtaining reliable estimates of lung doses and hence risk from occupational exposures to plutonium.
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