Toroidal ripple transport of beam ions in the mega-ampère spherical tokamak

The transport of injected beam ions due to toroidalmagnetic field ripple in the mega-ampère spherical tokamak (MAST) is quantified using a full orbit particle tracking code, with collisional slowing-down and pitch-angle scattering by electrons and bulk ions taken into account. It is shown that the level of ripple losses is generally rather low, although it depends sensitively on the major radius of the outer midplane plasma edge; for typical values of this parameter in MAST plasmas, the reduction in beam heating power due specifically to ripple transport is less than 1%, and the ripple contribution to beam ion diffusivity is of the order of 0.1 m² s⁻¹ or less. It is concluded that ripple effects make only a small contribution to anomalous transport rates that have been invoked to account for measured neutron rates and plasma stored energies in some MAST discharges. Delayed (non-prompt) losses are shown to occur close to the outer midplane, suggesting that banana-drift diffusion is the most likely cause of the ripple-induced losses.This work was funded by the RCUK Energy Programme under Grant EP/I501045, by the Australian Research Council, and by the European Communities under the Contract of Association between EURATOM and CCFE

Featural and configurational processes in the recognition of faces of different familiarity

Previous research suggests that face recognition may involve both configurational and piecemeal (featural) processing. To explore the relationship between these processing modes, we examined the patterns of recognition impairment produced by blurring, inversion, and scrambling, both singly and in various combinations. Two tasks were used: recognition of unfamiliar faces (seen once before) and recognition of highly familiar faces (celebrities). The results provide further support for a configurational - featural distinction. Recognition performance remained well above chance if faces were blurred, scrambled, inverted, or simultaneously inverted and scrambled: each of these manipulations disrupts either configurational or piecemeal processing, leaving the other mode available as a route to recognition. However, blurred/scrambled and blurred/inverted faces were recognised at or near chance levels, presumably because both configurational processing and featural processing were disrupted. Similar patterns of effects were found for both familiar and unfamiliar faces, suggesting that the relationship between configurational and featural processing is qualitatively similar in both cases

On steady poloidal and toroidal flows in tokamak plasmas

The effects of poloidal and toroidalflows on tokamakplasma equilibria are examined in the magnetohydrodynamic limit. “Transonic” poloidal flows of the order of the sound speed multiplied by the ratio of poloidal magnetic field to total field B₀/B can cause the (normally elliptic) Grad–Shafranov (GS) equation to become hyperbolic in part of the solution domain. It is pointed out that the range of poloidal flows for which the GS equation is hyperbolic increases with plasma beta and B₀/B, thereby complicating the problem of determining spherical tokamakplasma equilibria with transonic poloidal flows. It is demonstrated that the calculation of the hyperbolicity criterion can be easily modified when the assumption of isentropic flux surfaces is replaced with the more tokamak-relevant one of isothermal flux surfaces. On the basis of the latter assumption, a simple expression is obtained for the variation of density on a flux surface when poloidal and toroidalflows are simultaneously present. Combined with Thomson scattering measurements of density and temperature, this expression could be used to infer information on poloidal and toroidalflows on the high field side of a tokamakplasma, where direct measurements of flows are not generally possible. It is demonstrated that there are four possible solutions of the Bernoulli relation for the plasma density when the flux surfaces are assumed to be isothermal, corresponding to four distinct poloidal flow regimes. Finally, observations and first principles-based theoretical modeling of poloidal flows in tokamakplasmas are briefly reviewed and it is concluded that there is no clear evidence for the occurrence of supersonic poloidal flows.This work was jointly funded by the Australian Government through International Science Linkages Grant No. CG130047, the Australian National University, the United Kingdom Engineering and Physical Sciences Research Council, and by the European Communities under the contract of Association between EURATOM and CCFE

The relation between questions indicating transient ischaemic attack and stroke in 20 years of follow up in men and women in the Renfrew/Paisley Study

<b>STUDY OBJECTIVE</b> Transient ischaemic attack (TIA) is often a precursor to stroke, so identification of people experiencing TIA could assist in stroke prevention by indicating those at high risk of stroke who would benefit most from intervention for other stroke risk factors. The objective of this study was to investigate whether answers to a simple questionnaire for TIA could predict the occurrence of stroke in the following 20 years. DESIGNProspective cohort study, conducted between 1972 and 1976, with 20 years of follow up. <b>SETTING</b> Renfrew and Paisley, Scotland. <b>PARTICIPANTS</b> 7052 men and 8354 women aged 45-64 years at the time of screening completed a questionnaire and attended a physical examination. The questionnaire asked participants if they had ever, without warning, suddenly lost the power of an arm, suddenly lost the power of a leg, suddenly been unable to speak properly or suddenly lost consciousness. These four questions were taken as indicators of TIA and were related to subsequent stroke mortality or hospital admission. <b>MAIN RESULTS</b> For women, each question was significantly related to stroke risk, whereas for men only the question on loss of power of arm was significantly related to stroke risk. Men and women answering two or more questions positively had double the relative rate of stroke compared with men and women answering none of the questions positively, even after adjusting for other risk factors for stroke. <b>CONCLUSIONS</b> A simple questionnaire for TIA could help predict stroke over 20 years of follow up. Targeting men and women who report TIA with early treatment could help to prevent strokes from occurring

Adverse socioeconomic conditions in childhood and cause specific adult mortality: prospective observational study

<b>Objective:</b> To investigate the association between social circumstances in childhood and mortality from various causes of death in adulthood. Design: Prospective observational study. Setting: 27 workplaces in the west of Scotland. <b>Subjects:</b> 5645 men aged 35-64 years at the time of examination. <b>Main outcome measures:</b> Death from various causes. <b>Results:</b> Men whose fathers had manual occupations when they were children were more likely as adults to have manual jobs and be living in deprived areas. Gradients in mortality from coronary heart disease, stroke, lung cancer, stomach cancer, and respiratory disease were seen (all P<0.05), generally increasing from men whose fathers had professional and managerial occupations (social class I and II) to those whose fathers had semiskilled and unskilled manual occupations (social class IV and V). Relative rates of mortality adjusted for age for men with fathers in manual versus non-manual occupations were 1.52 (95% confidence interval 1.24 to 1.87) for coronary heart disease, 1.83 (1.13 to 2.94) for stroke, 1.65 (1.12 to 2.43) for lung cancer, 2.06 (0.93 to 4.57) for stomach cancer, and 2.01 (1.17 to 3.48) for respiratory disease. Mortality from other cancers and accidental and violent death showed no association with fathers' social class. Adjustment for adult socioeconomic circumstances and risk factors did not alter results for mortality from stroke and stomach cancer, attenuated the increased risk of coronary heart disease and respiratory disease, and essentially eliminated the association with lung cancer. <b>Conclusions:</b> Adverse socioeconomic circumstances in childhood have a specific influence on mortality from stroke and stomach cancer in adulthood, which is not due to the continuity of social disadvantage throughout life. Deprivation in childhood influences risk of mortality from coronary heart disease and respiratory disease in adulthood, although an additive influence of adulthood circumstances is seen in these cases. Mortality from lung cancer, other cancer, and accidents and violence is predominantly influenced by risk factors that are related to social circumstances in adulthood

Carboxyhaemoglobin concentration, smoking habit, and mortality in 25 years in the Renfrew/Paisley prospective cohort study

Objective: To investigate how carboxyhaemoglobin concentration is related to smoking habit and to assess whether carboxyhaemoglobin concentration is related to mortality. Design: Prospective cohort study. Setting: Residents of the towns of Renfrew and Paisley in Scotland. Participants: The whole Renfrew/Paisley study, conducted between 1972 and 1976, consisted of 7048 men and 8354 women aged 45–64 years. This study was based on 3372 men and 4192 women who were screened after the measurement of carboxyhaemoglobin concentration was introduced about halfway through the study. Main outcome measures: Deaths from coronary heart disease (CHD), stroke, chronic obstructive pulmonary disease (COPD), lung cancer, and all causes in 25 years after screening. Results: Carboxyhaemoglobin concentration was related to self reported smoking and for each smoking category was higher in participants who reported inhaling than in those who reported not inhaling. Carboxyhaemoglobin concentration was positively related to all causes of mortality analysed (relative rates associated with a 1 SD (2.93) increase in carboxyhaemoglobin for all causes, CHD, stroke, COPD, and lung cancer were 1.26 (95% confidence interval (CI) 1.19 to 1.34), 1.19 (95% CI 1.13 to 1.26), 1.19 (95% CI 1.13 to 1.26), 1.64 (95% CI 1.47 to 1.84), and 1.69 (95% CI 1.60 to 1.79), respectively). Adjustment for self reported cigarette smoking attenuated the associations but they remained relatively strong. Conclusions: Self reported smoking data were validated by the objective measure of carboxyhaemoglobin concentration. Since carboxyhaemoglobin concentration remained associated with mortality after adjustment for smoking, carboxyhaemoglobin seems to capture more of the risk associated with smoking tobacco than does self reported tobacco consumption alone. Analysing mortality by self reported cigarette smoking underestimates the strength of association between smoking and mortality