Photolysis of complexes of dimethyl sulfoxide (DMSO) with chlorine atoms results in rapid and permanent photobleaching which may be due to intramolecular hydrogen abstraction. The effects of solvent polarity were examined in a wide variety of DMSO-carbon tetrachloride mixed solvents. The quantum yields of photobleaching decreased from 0.27 to 0.08 as the solvent polarity increased, while significant changes were observed in the low DMSO concentration range (< 0.2 mol dm -3 ). This cannot be accounted for by simple solvent polarity effects. The effects of polar and nonpolar additives were also examined and it is concluded that the specific solvation effect of DMSO was the main cause of the significant change in the quantum yields in the low concentration range of DMSO.

DMSO–Cl complexes were produced by pulse radiolysis of mixtures of dimethyl sulfoxide (DMSO) and CCl4 of various compositions, and photochemical reactions were studied by laser flash photolysis. The quantum yields of intramolecular hydrogen abstraction depend strongly on both solvent composition and additives.

--A number of children with learning disabilities (LD) are not good at visuomotor control. In this study, we analyzed hand trajectories and joint angles during reaching movement tasks under rotated visual feedback in subjects with and without LD. The error in ballistic movement was determined by measuring the angle between the direction in which the subject started to reach out and the direction of the target (error angle), and the error in corrective movement was determined by the measuring the area between the trajectory and a straight line drawn between the starting point and the end point (error area). In the initial movement when the visual field had been rotated 30 deg, error angles were about -30 deg in both the LD and normal groups; however, the error area was 2.9 cm 2 greater in the LD group than in the normal group. On the other hand, joint paths of the shoulder in reaching the same target tended to change in the LD group. These results suggested that the LD subjects had worse skills in corrective movement than did the normal subjects and that adaptation by the LD subjects occurred more slowly than that by the normal subjects.