A data processing apparatus stores continuous area management information which associates head position information of each continuous area on the storage medium with a continuous size thereof. The polycrystalline silicon film is formed by laser annealing with an energy density that completely melts the thin-film part but does not completely melt the thick-film part. Said isolated nucleic acid fragment coding for a protein capable of binding with the AT2 receptor is selected among the group consisting of the sequences SEQ ID NO: 1, 3, 5, 7 and 9. The probe when connected to a suitable electrical system is capable of identifying microbiological activity resulting in microbiologically influenced corrosion; microbiological activity not resulting in microbiologically influenced corrosion; microbiological inactivity, coupled with non-microbiologically influenced corrosion; and microbiological inactivity; and no corrosion. The recursive invocation of this procedure ultimately determines one or more paths through the network from the initiator agent to one more more leaf agents.