Proton Pumping P Systems -- A Binary Data Structure for Membrane Processors: Connectivity Arrays -- Parsing with Active P Automata -- Universality of Minimal Symport/Antiport: Five Membranes Suffice -- Collapsing Hierarchies of Parallel Rewriting P Systems without Target Conflicts -- Evolution and Observation: A New Way to Look at Membrane Systems -- Tiling Rectangular Pictures with P Systems -- Simulating Boolean Circuits with P Systems -- P Systems Running on a Cluster of Computers -- Implementing in Prolog an Effective Cellular Solution to the Knapsack Problem -- On the Dynamics of PB Systems: A Petri Net View -- P Systems Generating Hexagonal Picture Languages -- A Membrane System for the Leukocyte Selective Recruitment -- P Systems with Cutting/Recombination Rules Assigned to Membranes -- ? -P Automata with Communication Rules -- The Number of Membranes Matters -- An Agent-Based Behavioural Model of Monomorium Pharaonis Colonies -- Can Hyperbolic Geometry Be of Help for P Systems? -- A Linear-Time Solution to the Knapsack Problem Using P Systems with Active Membranes -- A Reconfigurable Hardware Membrane System -- P Systems and Petri Nets -- Simulation of Mobile Ambients by P Systems. Part 1 -- Computing Partial Recursive Functions by Transition P Systems -- P Systems with External Input and Learning Strategies -- A Distributed Simulation of Transition P Systems -- About Splicing P Systems with Immediate Communication and Non-extended Splicing P Systems.