A cache-coherent network interface includes registers or buffers addressable by a processor with reference to an address space of the processor. According to the invention the locking device in at least one plane orthogonal to a discharge stroke direction has an at least zonally or circumferentially corrugated andor polygonal cross-section. The nanotube is then provided in a circuit, such as a Wheatstone Bridge or other circuit, and the circuit will produce an output signal proportional to the change in electrical characteristics of the nanotube according to the applied force. In addition, methods for delivering a drug to a brain through a spinal canal are described. A filter unit prevents a possible direct current from the light sensitive member from reaching the first input. The spreader bar can be reinserted after the hammock is laundered.