%0 Generic %D 2013 %T Bridging Membrane and Reaction Systems – Further Results and Research Topics %A Gheorghe Paun %A Mario J. Pérez-Jiménez %A Grzegorz Rozenberg %C Warsaw, Poland %I IOS Press %K fypercomputation %K Membrane computing %K reaction system %K SAT %K semilinear set %N 1-4 %P 99-114 %R 10.3233/FI-2013-898 %U http://iospress.metapress.com/content/y724g8012056k237/?issue=1&genre=article&spage=99&issn=0169-2968&volume=127 %V 127 %X This paper continues an investigation into bridging two research areas concerned with natural computing: membrane computing and reaction systems. More specifically, the paper considers a transfer of two assumptions/axioms of reaction systems, non-permanency and the threshold assumption, into the framework of membrane computing. It is proved that: (1) spiking neural P systems with non-permanency of spikes assumption characterize the semilinear sets of numbers, and (2) symport/antiport P systems with threshold assumption (translated as ω multiplicity of objects) can solve SAT in polynomial time. Also, several open research problems are stated. %8 10/2013