The affiliation motive and perceptual sensitivity to faces.

An attempt was made to predict from imaginative measures of the affiliation motive the frequency with which S selects human faces from similar but nonhuman figures in a perceptual task. The Ss were 93 male undergraduates who responded to pictures with imaginative stories scored for n Affiliation. A month later they were introduced to the perceptual task which required that they state which of 4 figures flashed on a screen was clearest, all stimuli being below the recognition threshold. On each trial 1 of the 4 stimuli was a face and the others were similar but affiliation-neutral. Ss high in n Affiliation recognized faces significantly more frequently than those low in n Affiliation. Thus, the predicted relationship between motivation and the perceptual selection of motive-relevant stimuli was supported. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Permanent fluorescent test slides

Permanent test slides for fluorescence microscopy can easily be prepared by suspending Helecon fluorescent pigments, numbers 2225 and 2266, in DPX and mounting under a cover glass in the usual way. These two pigments simulate the excitation and emission of fluorescein conjugates and acridine orange. Eight other pigments have been tested and their properties are described.     

The Influence of Excimer Formation on Solvent-Solute Energy Transfer in Organic Liquid Scintillators

Excimer (excited dimer) formation occurs in all the aromatic hydrocarbon solvents used in liquid scintillators. The influence of this process on solvent-solute energy transfer has been studied for a model system: 9, 10-diphenyl anthracene (DPA) in 1, 6-dimethyl naphthalene (DMN), diluted by n-heptane (Hp). Data on the fluorescence lifetimes, spectra and quantum yields and the viscosity of DMN in Hp are used to analyze the results. It is found that the energy transfer rate parameters of the excited monomer and excimer differ, but that they are independent of Hp dilution. The influence of diffusion and solvent energy migration on solvent-solute energy transfer are discussed, and a migration mechanism involving excimer formation and dissociation is proposed.