The question of how meaningful associations between verbal and spatial information might be utilized to facilitate working memory performance is potentially highly instructive for models of memory function. The present study explored how separable processing capacities within specialized domains might each contribute to this, by examining the disruptive impacts of simple verbal and spatial concurrent tasks on young adults' recall of visually presented digit sequences encountered either in a single location or within a meaningful spatial "keypad" configuration. The previously observed advantage for recall in the latter condition (the "visuospatial bootstrapping effect") consistently emerged across 3 experiments, indicating use of familiar spatial information in boosting verbal memory. The magnitude of this effect interacted with concurrent activity; articulatory suppression during encoding disrupted recall to a greater extent when digits were presented in single locations (Experiment 1), while spatial tapping during encoding had a larger impact on the keypad condition and abolished the visuospatial bootstrapping advantage (Experiment 2). When spatial tapping was performed during recall (Experiment 3), no task by display interaction was observed. Outcomes are discussed within the context of the multicomponent model of working memory, with a particular emphasis on cross-domain storage in the episodic buffer (Baddeley, 2000).

Flight crew are occupationally exposed to several potentially carcinogenic hazards; however, previous investigations have been hampered by lack of information on lifestyle exposures. The authors identified, through the United Kingdom Civil Aviation Authority medical records, a cohort of 16,329 flight crew and 3,165 air traffic control officers (ATCOs) and assembled data on their occupational and lifestyle exposures. Standardised incidence ratios (SIRs) were estimated to compare cancer incidence in each occupation to that of the general population; internal analyses were conducted by fitting Cox regression models. Allcancer incidence was 20-29% lower in each occupation than in the general population, mainly due to a lower incidence of smoking-related cancers [SIR (95% CI) 5 0.33 (0.27-0.38) and 0.42 (0.28-0.60) for flight crew and ATCOs, respectively], consistent with their much lower prevalence of smoking. Skin melanoma rates were increased in both flight crew (SIR 5 1.87; 95% CI 5 1.45-2.38) and ATCOs (2.66; 1.55-4.25), with rates among the former increasing with increasing number of flight hours (p-trend 5 0.02). However, internal analyses revealed no differences in skin melanoma rates between flight crew and ATCOs (hazard ratio: 0.78, 95% CI 5 0.37-1.66) and identified skin that burns easily when exposed to sunlight (p 5 0.001) and sunbathing to get a tan (p 5 0.07) as the strongest risk predictors of skin melanoma in both occupations. The similar sitespecific cancer risks between the two occupational groups argue against risks among flight crew being driven by occupationspecific exposures. The skin melanoma excess reflects sun-related behaviour rather than cosmic radiation exposure.

Aeromedical emphasis on minimizing cardiovascular risk and monitoring the mental health of pilots remains appropriate. Age should influence the content and periodicity of regulatory aeromedical assessments. The demonstrated annual incapacitation rate of 0.25% may provide a basis for quantifying the acceptable risk for a pilot undertaking single pilot commercial air transport operations.

The differences between aircrews and the general population are consistent with a strong "healthy worker effect." Aircrews and ATCOs undergo a similar employment selection process and thus taking the latter as the reference population, in addition to the general population, will help to minimize the "healthy worker effect" and gain insight into its biases.

Even when comparisons were made with the highest income quintile of the general population to control for socio-economic status, pilots had a significantly lower prevalence of obesity and smoking. This finding is consistent with a strong 'healthy worker effect'.