A system monitors the status of persistent connections between a set of servers and a set of clients, and identifies any clients not having at least one active connection with a server. The neural interfaces comprise electrical and chemical interfaces for neural recording, electrical stimulation, chemical delivery, chemical sensing, chemical sampling, cell delivery, genetic material delivery andor other functions of interest. The first end has an aperture extending therethrough and the first wall has an opening extending therethrough. The method of the present invention also verifies that neighborhood contain the same focal points. The piston further has a recess portion about a central axis of the piston designed to reduce temperatures near a tip portion of the fuel injector. The method of performing decoding an encoded codeword using a parity check matrix, comprises decoding the codeword using the parity check matrix, wherein the parity check matrix includes a plurality of layers, each of which includes at least one or more rows split exclusively from a specific row of a base parity check matrix.