The present invention relates to pyrazinoylguanidine compounds represented by formula :where the structural variables are defined herein. Alteration of the picture updating frequency of the stream of pictures expressed by the MPEG data stream can thereby be achieved very simply, while in addition the overall amount of MPEG data can be substantially reduced. The mounting mechanism used to engage and disengage the heat exchangers is configured to isolate the force applied to the two heat exchangers. The carry creation unit may create an ordered plurality of carry bits each corresponding to one or more of the generate and propagate bit pairs. The circuit includes electrodes exposed to the exterior of the hollow body that, when in contact with water or other liquid beverage, cause the circuit to turn on the LED and illuminate the beverage. The method includes providing the optical medium, and recording information on the optical medium by irradiating an optical spot thereon.