A pneumatically actuated fluid control valve includes a piston and a piston actuator including a permanent magnet. The subject polypeptide and nucleic acid compositions find use in a variety of applications, including research, diagnostic, and therapeutic agent screening applications. A kit for inducing apoptosis of malignant cells is also disclosed. The flexible cutting element has a means to move toward a second shape suitable for forming a cavity in tissue. According to the present invention as described above, the microcontroller cannot omit any one of the encoder signals for the interrupt period. The plug of the impeller is split so that when the fastener is inserted into the passage the plug expands to contact the bore and create an interference fit between the shaft and the impeller.