In two identical and simultaneously performed case-control studies of basal cell carcinoma (BCC) and cutaneous malignant melanoma (CMM) with age-matched, sex-matched and residence-matched controls, skin pigmentation was measured objectively by skin reflectance spectroscopy in 145 BCC patients and 174 matched controls and in 168 CMM patients and 176 matched controls. Measurements were performed at the forehead, the upper chest, the upper back, the lateral and medial aspects of the upper arm, and the buttocks. Self-estimation of sun exposure in childhood, in youth and in adulthood was performed by all subjects. There were no statistically significant differences in constitutive skin pigmentation at the buttocks between BCC patients and controls (P = 0.96) or between CMM patients and controls (P = 0.13). Facultative skin pigmentation in ultraviolet-exposed sites was not significantly different between BCC patients and controls except that women patients had higher pigmentation at the lateral side of the upper arm. For CMM, men patients had higher pigmentation at the lateral side of the upper arm. Self-estimations of sun exposure did not show differences between patients and controls but indicated high exposure levels in childhood and youth and in adult leisure time. Sun exposure estimated by increase in facultative pigmentation above the constitutive level (the Sun Exposure Index) was not significantly different between BCC patients and controls, whereas CMM men patients had higher estimates for the lateral side of the upper arm, the chest and the back.

No abstract

Abstrocf-A 252 channel FM sonar is developed to generate images of objects buried in sediments using reflection tomography. An omnidirectional source, transmitting FM pulses over the band of 2 to 12 IrHz, illuminates buried targets.The backscattered signals are measured with 252 hydrophones and processed with a digital matched filter. Coherent nearfield focusing generates a 3D map of acoustic intensity for each transmission event. As the sonar approaches and passes buried targets, the processor generates 3D matrices of acoustic intensity, overlapping in space and referenced to a coordinate system fixed to the seabed. The eo-located pixels are added incoherently to generate a multi-aspect image of the target. The change in vehicle position between transmissions is measured with a DVL(dopp1er velocity log) and IMU (inertial measurement unit). The resulting reflection tomographic images provide target shape information nsefnl for target classification. The sonar can be mounted on small AUVs by replacing the 252 channel, 1.5 m diameter array with one meter long line arrays mounted as wings. The receiver aperture is generated synthetically using the near field focusing processor which performs time delay focusing based on the positions of the hydrophones in the line array and vehicle motion data. A comparison between synthetic swath and tomographic images of a rigid spherical target in water shows the improvement provided by reflection tomography.

No abstract