Invited Lectures.- Psim: A Computational Platform for Metabolic P Systems.- Modeling the Dynamics of HIV Infection with Conformon-P Systems and Cellular Automata.- (UREM) P Systems with a Quantum-Like Behavior: Background, Definition, and Computational Power.- The Calculus of Looping Sequences for Modeling Biological Membranes.- Membrane Computing in Connex Environment.- Regular Papers.- Skin Output in P Systems with Minimal Symport/Antiport and Two Membranes.- On the Reachability Problem in P Systems with Mobile Membranes.- Modeling Symport/Antiport P Systems with a Class of Hierarchical Petri Nets.- A Hybrid Approach to Modeling Biological Systems.- Causality in Membrane Systems.- Simulating the Bitonic Sort Using P Systems.- On the Number of Agents in P Colonies.- Events, Causality, and Concurrency in Membrane Systems.- P Systems with String Objects and with Communication by Request.- On the Dynamics of PB Systems with Volatile Membranes.- A Logarithmic Bound for Solving Subset Sum with P Systems.- A Formal Framework for Static (Tissue) P Systems.- Conformon-P Systems with Negative Values.- Optimizing Evolution Rules Application and Communication Times in Membrane Systems Implementation.- Hill Kinetics Meets P Systems: A Case Study on Gene Regulatory Networks as Computing Agents in silico and in vivo.- Solving Numerical NP-Complete Problems with Spiking Neural P Systems.- Towards a Complete Covering of SBML Functionalities.- Active Membrane Systems Without Charges and Using Only Symmetric Elementary Division Characterise P.- Balancing Performance, Flexibility, and Scalability in a Parallel Computing Platform for Membrane Computing Applications.- On Flip-Flop Membrane Systems with Proteins.- Characterizing Membrane Structures Through Multiset Tree Automata.- OPERAS CC : An Instance of a Formal Framework for MAS Modeling Based on Population P Systems.