This proposal outlines an approach for interfacing Synchronous Transfer Mode and Asynchronous Transfer Mode networks and for transporting voice, fax and voice-band data calls by the ATM network in an efficient manner. The software agent can be a platform independent software object. The reactive groups provide for chemisorption or covalent bonding to the substrate surface. The invention further relates to drug-screening methods using the phosphodiesterase polypeptides and polynucleotides to identify agonists and antagonists for diagnosis and treatment. The robot holds one of a plurality of types of workpiece components using the hand units of the first arm and the second arm at the same time, and the remaining type of the workpiece components is held and carried by the hand unit of the first arm or the second arm.