Measurement and modelling of air pollution and atmospheric chemistry in the U.K. West Midlands conurbation: overview of the PUMA Consortium project.

The PUMA (Pollution of the Urban Midlands Atmosphere) Consortium project involved intensive measurement campaigns in the Summer of 1999 and Winter of 1999/2000, respectively, in which a wide variety of air pollutants were measured in the UK West Midlands conurbation including detailed speciation of VOCs and major component analysis of aerosol. Measurements of the OH and HO2 free radicals by the FAGE technique demonstrated that winter concentrations of OH were approximately half of those measured during the summer despite a factor of 15 reduction in production through the photolysis of ozone. Detailed box modelling of the fast reaction chemistry revealed the decomposition of Criegee intermediates formed from ozone-alkene reactions to be responsible for the majority of the formation of hydroxyl in both the summer and winter campaigns, in contrast to earlier rural measurements in which ozone photolysis was predominant. The main sinks for hydroxyl are reactions with NO2, alkenes and oxygenates. Concentrations of the more stable hydrocarbons were found to be relatively invariant across the conurbation, but the impacts of photochemistry were evident through analyses of formaldehyde which showed the majority to be photochemical in origin as opposed to emitted from road traffic. Measurements on the upwind and downwind boundaries of the conurbation revealed substantial enhancements in NOx as a result of emissions within the conurbation, especially during westerly winds which carried relatively clean air. Using calcium as a tracer for crustal particles, it proved possible to reconstruct aerosol mass from the major chemical components with a fairly high degree of success. The organic to elemental carbon ratios showed a far greater influence of photochemistry in summer than winter, presumably resulting mainly from the greater availability of biogenic precursors during the summer campaign. Two urban airshed models were developed and applied to the conurbation, one Eulerian, the other Lagrangian. Both were able to give a good simulation of concentrations of both primary and secondary pollutants at urban background locations.

Postural control: visual and cognitive manipulations.

Numerous questions exist regarding the utilization of sensory information for postural control. Past research has established the possibility that cognitive tasks requiring visual perception may affect the processing of visual information used for postural control. The purpose of this study was two fold: (1) to investigate the effects of varying demands of visual perception and (2) to evaluate the effects of performing a cognitive task on postural control in healthy, young adults (N=30). Three posture-related dependent variables were recorded during the manipulation of two independent variables (eye movement and modality of presentation of a cognitive task). The two levels of eye movement were movement and no movement, while the three levels of modality of presentation were visual, auditory, and none. A 2x3 repeated measures ANOVA was applied to the data to investigate the presence of group differences. Significantly more variability was observed in the no cognitive condition than the visual and the auditory for medial-lateral (M--L) COP variability. Additionally, the eye movement condition revealed significantly greater M--L COP variability than the no eye movement condition. No differences were observed between the visual and auditory conditions for any dependent variable. Therefore, the greatest COP variability was observed in the eye movement and no cognitive condition. Further, an interesting relationship between the measures of COP variability and sway velocity was described.

Oophoropexy and ovarian function in the treatment of Hodgkin's disease.

Fifty-four female patients under 45 years of age were followed-up for assessment of ovarian function after treatment for Hodgkin's disease. Forty-six patients had oophoropexy performed, but it was found that in only 28 (60.8%) were the ovaries sufficiently displaced from their normal positions that, had an inverted 'Y' field of irradiation been applied, the ovaries would have been spared. In the 12 patients who were treated by irradiation alone (including an inverted 'Y' field), only one patient maintained normal ovarian function. Therefore, it is suggested that oophoropexy and the shielding performed at inverted 'Y' irradiation has proved of limited value in preserving ovarian function further measures should be taken.