Ontogenesis of the pituitary-gonadal axis in the chick embryo.

Pregnant Mare Serum and Human Chorionic Gonadotropin Stimulate Ovarian ∆5-3β-Hydroxysteroid Dehydrogenase in Aged Mice

Publisher Summary Perception deals with structure, or more specifically, with correlation among stimuli, among elements in stimuli, and among the representations of all these in the neural processes of the perceiver. Perception is an active process, involving selection, that is, the organism perceives rather than receives information. As the perceiving organism necessarily processes and keeps only a portion of this array, the important questions are what is processed; how is it processed; and why is it processed. This chapter explains the concept of information processing by humans. It also explains the basic tenets of structure and perception, including the concept of redundancy; the measurement of structure, both directly and indirectly; the development of relevant perceptual processes in humans; and the directions that further research might take in specifying and explaining the ways in which humans process information from their environment. It discusses a series of experiments demonstrating the efficacy of the pattern-redundancy approach as reflected in performance, focusing upon the concepts coming from Garner's (1962) book and from the earlier studies.

Perceptual structure and selection

Ovarian ∆5-3β-hydroxysteroid dehydrogenase in aging rats

E stato studiato il quadro enzimatico dei corpi lutei (C.L.) di recente formazione nelle ovaie di ratte ipofisectomizzate. In particolare si e constatato come la comparsa dell'attivita 20α-idrossisteroide deidrogenasica non sia impedita dall'ipofisectomia. Si suggerisce la possibilita che l'ipofisi eserciti una azione inhibitrice sulla comparsa di questo enzima.

E. Turolla

Papers

Histochemistry of ovarian 20α-hydroxysteroid dehydrogenase in mature hypophysectomized rats