Compounds that are central nervous system drug candidates for the treatment of cognitive decline and, more particularly, Alzheimer’s disease are provided. The controller, typically a single ASIC, is operable to distribute a print job associated with each received request for printing to one of a plurality of print mechanisms wherein each print mechanisms is coupled to the controller and operable to print a document as directed by the associated print job. The combustion chamber is delimited by the piston. The counter roller moves to, during the toner concentration detection, a position opposed to the toner concentration sensor across the intermediate transfer belt. In the thin film transistor in the driver circuit portion, the semiconductor layer is sandwiched between a gate electrode layer and a conductive layer.