Language training: some data on response classes and generalization to an occupational setting.

The study was designed to investigate whether present plural uncontractible forms of auxiliary and copula (are) are members of a single response class. A mentally retarded adult female served as the subject. Within a behavior training, reversal, and reinstatement design, only the uncontractible auxiliary are was trained, reversed, and reinstated using operant training contingencies. On probes, however, sentences involving auxiliary as well as those involving copula were tested. It was found that training the uncontractible auxiliary are was sufficient to induce generalized production of the uncontractible copular are. Subsequently, when the auxiliary production was reversed, the copular production was also reversed. Finally, when the auxiliary production was reinstated, the copular production was automatically reinstated. The results suggest that auxiliary and copula are, although distinct grammatically and developmentally, belong to a single response class. The study also revealed that with the help of operant training and generalization strategies, the subject was able to use the trained features in conversational speech exhibited in her occupational setting.

Conformation and activity of chymotrypsin: the pH-dependent, substrate-induced proton uptake.

Hydrogen ion uptake by chymotrypsin during reversible binding of specific substrate is shown to be due to an ionizing group of the enzyme with a pK(apparent) approximately 9 in the free enzyme. This pK(apparent) is shifted to higher value in the enzyme-substrate complexes. Previous results indicating an equilibrium, controlled by this ionizing group, between active and inactive conformational forms of chymotrypsin are confirmed.