Semiconductor materials, particularly III-V materials used to form, e. The outdoor light string support system, includes a support member having a first member, a second member extending downwardly from an edge of the first member, a third member traversely extending from the second member, and a plurality of apertures within the third member for receiving a plurality of bulbs or branch wires from a light string. The carriages include a plurality of pushing prongs which extend, perpendicular to the conveying means, from slide means slidingly mounted on gliding means fastened to the conveying means crosswise to a forward movement direction of conveying means. The door assembly further includes an opening mechanism to release the cover from the secure closed position to the open position. Embodiments of the invention advantageously enhance the practicality of using digital linearization and predistortion amplification techniques. The invention also provides nucleic acid sequences, vectors, and host cells useful in the production of this amidase.