A cascading learning system as a semantic search is described. A degree of partial programming can be determined by a pre-erase read operation which determines a highest programmed word line, or which determines whether there is a programmed storage element in a subset of word lines above a small subset of source side word lines. Methods of using such compositions to treat diseases or conditions suitably treated by niacin are also provided which result in reduced flushing. An efficient filtering and stalling system employed at the receive side of the backplane prevents the highly parallel traffic from causing receive side congestion.