A METHOD TO IDENTIFY AND LOCALIZE A SINGLE HOT PARTICLE IN THE LUNGS USING AN ARRAY OF HIGH-PURITY GERMANIUM DETECTORS FOR IMPROVED ESTIMATE OF THE DEPOSITED ACTIVITY.

A new method has been developed to identify and localize a single hot particle in the lungs using an array of four high-purity germanium detectors. The method is based upon calculating a set of three count rate ratios (generated by each individual detector in the array) that are evaluated in sequence to designate whether the measured deposition can be associated with a hot particle rather than the default assumption of a uniform activity distribution. Identification and localization of the hot particle are determined from a single in vivo measurement in which detectors are positioned above and below the thorax. The method was tested using an anthropomorphic thorax phantom in which point sources of 241Am, 137Cs and 60Co were individually inserted in the lungs at 15 different locations and were measured using a scanning bed whole-body counter. Depending upon source location and photon energy, a bias of -35% up to +76% could be introduced by falsely assuming a uniform activity distribution in the lungs. This bias would directly translate to an erroneous dose estimate to the lungs. It was demonstrated that by using the appropriate detector efficiencies for the single hot particle, the bias associated with the activity determination is reduced to <10% and ~2% in average.

The interactive effect of chronic exposure to noise and job complexity on changes in blood pressure and job satisfaction: a longitudinal study of industrial employees.

The hypothesis of this study was that noise exposure level and job complexity interact to affect changes in blood pressure (BP) levels and job satisfaction over 2-4 years of follow-up. Results showed that among workers exposed to high noise, those with complex jobs showed increases in BP that were more than double shown by those with simple jobs. Under low noise exposure, there was a small increase in BP for workers with complex jobs but about a 3-fold increase in workers with simple jobs. The prevalence of elevated BP showed a similar trend. Job satisfaction increased among workers with complex jobs but was much less in those exposed to high noise. It was concluded that exposure to occupational noise has a greater negative impact on changes in BP and job satisfaction over time among those performing complex jobs. In contrast, job complexity had a clear beneficial effect for workers exposed to low noise.

Some observations and questions in intensive psychotherapy.

The authors discuss their observations of acute psychiatric patients in a day hospital, noting the universality of the existential concerns that arise once the patient has confronted his illness. They discuss the problem of what determins a "cure" in emotional disturbances and suggest that the primary issue is for patients to learn to live as healthy people within the limits of their individual potential.