Results 1 
3 of
3
Discreteness of the Spectrum for Some Differential Operators With Unbounded Coefficients in R^n
"... We give sufficient conditions for the discreteness of the spectrum of differential operators of the form Au = \Gamma\Deltau +hrF;rui in L 2 (R n ) where d(x) = e \GammaF (x) dx and for Schrödinger operators in L 2 (R n ). Our conditions are also necessary in the case of polynomial coeffic ..."
Abstract

Cited by 4 (1 self)
 Add to MetaCart
We give sufficient conditions for the discreteness of the spectrum of differential operators of the form Au = \Gamma\Deltau +hrF;rui in L 2 (R n ) where d(x) = e \GammaF (x) dx and for Schrödinger operators in L 2 (R n ). Our conditions are also necessary in the case of polynomial coefficients.
INTERRESPONSE TIME CHANGES AS A FUNCTION OF WATER DEPRIVATION AND AMPHETAMINE1
, 1974
"... Drug effects on operant behavior are often characterized by their effects on rate of responding, usually expressed as the number of responses per unit of time. The time between two consecutive responses constitutes an interresponse time (IRT) , and this nmeasune lmas been used also to characterize t ..."
Abstract
 Add to MetaCart
Drug effects on operant behavior are often characterized by their effects on rate of responding, usually expressed as the number of responses per unit of time. The time between two consecutive responses constitutes an interresponse time (IRT) , and this nmeasune lmas been used also to characterize the effects of drugs on operant behavior. TilTs wimich occur during a session can be classified on a statistical basis as: 1) shortIRT, an IRT(s) of simort duration generated by highfrequency responses; 2) pause, an IRT of long duration generated by lowfrequency responses; and 3) postreinforcement pause, an IRT which immediately follows reinforcement. This investigation used three schedules of water reinforcement (fixedratio 20, fixedinterval 90seconds and variableinterval 20seconds) to examine how these IRT classes are influenced by changes in water deprivation conditions or amphetamine administration. Baseline IRT distnibutions depended upon the schedule of reinforcement. Changes induced by doses of ampimetamine or alterations in level of water deprivation were compared and contrasted. ShontIRTs that characterized fixedratio 20 performance were resistant to change with increasing doses of amphetamine, but were increased in duration with decreasing water