A hybrid integrated trunk and subscriber line interface
A two-chip hybrid integrated trunk and subscriber line interface has been fabricated for voice and data applications. This paper will discuss features including a programmable battery feed with lightning protection, battery-reversal signaling, 2-4 wire conversion, loop closure detection and power down capability.
A Versatile Subscriber Line Interface Circuit
This paper will describe a bipolar SLIC LSI for telephone switching. The aluminum master slices accommodate central offices as well as PABXs, ie. constant resistance feed and constant current feed. The SLICs are programmable by the external components to meet any of line impedance requirements.
Similarities in protozoan and flatworm habituation behavior.
ONE problem in the study of habituation in protozoa is that similar results, given the same experimental manipulations, may not be obtained in metazoa. I shall compare habituation behaviour in the protozoan Spirostomum with that in the micrometazoan Rhabdocoel flatworm Stenostomum; it remains to be shown whether there is a correspondence between protozoa and metazoa both in behaviour and in their underlying chemical processes. Both these organisms contract in response to mechanical and touch stimuli: when subjected to repeated stimulation, they habituate1. Furthermore, the more intense the stimulus, the longer it takes for habituation to occur1.