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Bilayers and multilayers of a mutated form of cytochrome P450 reductase, P499C, form ordered structures when adsorbed at Au(110)/phosphate buffer interfaces. Reflection anisotropy spectroscopy (RAS) indicates that the degree of order increases with the number of layers and that the optical dipoles that contribute to the RAS profiles observed from the bilayer lie in planes that are oriented vertical to the surface and along one of the principal axes of the Au(110) surface. The contribution of the Au(110) substrate and the protein to the RAS profiles of the combined systems show an opposite dependence on the potential applied to the Au(110) electrode. The RAS profile observed from an adsorbed multilayer is dominated by the contribution from the protein. [ABSTRACT FROM AUTHOR]

The reflection anisotropy spectra (RAS) observed initially from Au(110)/phosphate buffer interfaces at applied potentials of −0.652 and 0.056 V are very similar to the spectra observed from ordered Au(110) (1 × 3) and anion induced (1 × 1) surface structures respectively. These RAS profiles transform to a common profile after cycling the potential between these two values over 72 h indicating the formation of a less ordered surface. The RAS of a monolayer of a P499C variant of the human flavoprotein cytochrome P450 reductase adsorbed at 0.056 V at an ordered Au(110)/phosphate buffer interface is shown to arise from an ordered layer in which the optical dipole transitions are in a plane that is orientated roughly normal to the surface and parallel to either the [ABSTRACT FROM AUTHOR]

We show that thymine self-assembles into an ordered structure when adsorbed at a Au(110)/liquid interface. Reflection anisotropy spectroscopy (RAS) shows that as found for cytosine and adenine the adsorbed thymine molecules are oriented essentially vertically on the Au(110) surface with the molecule aligned along one of the principal axes of the Au(110) surface. Simulations of the RA spectra to an empirical model indicates that as found for adsorbed cytosine and adenine, thymine is aligned along the [ $1{\bar {1}}0$] direction on the Au(110) surface. [ABSTRACT FROM AUTHOR]

Provides information on experiments which examined discrimination learning and learning of letters by severely subnormal (SSN) children. Sources of evidence for suggesting that SSN children learn a discrimination on the basis of learning to respond to the area which provides the relevant cue; Educational problems dealt by the experiments; Significant factors in pattern learning by SSN children.