New Solutions to the Firing Squad Synchronization Problems for Neural and Hyperdag P Systems

We propose two uniform solutions to an open question: the Firing Squad Synchronization Problem (FSSP), for hyperdag and symmetric neural P systems, with anonymous cells. Our solutions take e_c+5 and 6e_c+7 steps, respectively, where e_c is the eccentricity of the commander cell of the dag or digraph underlying these P systems. The first and fast solution is based on a novel proposal, which dynamically extends P systems with mobile channels. The second solution is substantially longer, but is solely based on classical rules and static channels. In contrast to the previous solutions, which work for tree-based P systems, our solutions synchronize to any subset of the underlying digraph; and do not require membrane polarizations or conditional rules, but require states, as typically used in hyperdag and neural P systems

Investigations on nitrification in the water and the sediment of the Kiel Bight (Baltic Sea)

The results of this study show that chemoautrophic nitrification is the most important source ot nitrate in the brackish water of the Kiel Bight. The main nitrification potential is localized in the sediment. Nitrification activities were measured from January to March 1978 in a sand sediment from a beach station in the Kiel Fjord and in March and May 1979 in the sand sediment of the central Kiel Bight. The nitrification rates measured at the beach station lay between 0.9 x 10-3 μgat N/cm3 x h and 4.5 x 10-3 μgat N/cm3 x h and in the Kiel Bight between 1.9 x 10-2 μgat N/cm3 x h and 4.7 x 10-2 μgat N/cm3 x h