The invention concerns a simple and user-friendly actuating device for miniature keyboards or miniature input tablets. Multiple reflections are created by illuminating the display screen form a plurality of directions, or by illuminating the display screen with light beams of differing polarizations. Pressurized pulses of air can be directed around a circumference of the distributor to at least partially fluidize the particulate material to facilitate the material passing through the metering orifice. Examples of implementations of the present invention include a credit card system, an RFID tag system, an electronic tollgate system, an automated callback system, and an inventory transport system. The present invention is a circuit design that utilizes two transistor types that can be manufactured together thereby reducing the number of processing steps and masks and resulting in lower cost. This invention also relates to inhibiting the biosynthesis or action of such polynucleotides or polypeptides and to the use of such inhibitors in therapy.