Two-step simulations of reaction systems by minimal ones

Reaction systems were introduced by Ehrenfeucht and Rozenberg with biochemical applications in mind. The model is suitable for the study of subset functions, that is, functions from the set of all subsets of a finite set into itself. In this study the number of resources of a reaction system is essential for questions concerning generative capacity. While all functions (with a couple of trivial exceptions) from the set of subsets of a finite set S into itself can be defined if the number of resources is unrestricted, only a specific subclass of such functions is defined by minimal reaction systems, that is, the number of resources is smallest possible. On the other hand, minimal reaction systems constitute a very elegant model. In this paper we simulate arbitrary reaction systems by minimal ones in two derivation steps. Various techniques for doing this consist of taking names of reactions or names of subsets as elements of the background set. In this way also subset functions not at all definable by reaction systems can be generated. We follow the original definition of reaction systems, where both reactant and inhibitor sets are assumed to be nonempty

Reaction Systems and Synchronous Digital Circuits

A reaction system is a modeling framework for investigating the functioning of the living cell, focused on capturing cause-effect relationships in biochemical environments. Biochemical processes in this framework are seen to interact with each other by producing the ingredients enabling and/or inhibiting other reactions. They can also be influenced by the environment seen as a systematic driver of the processes through the ingredients brought into the cellular environment. In this paper, the first attempt is made to implement reaction systems in the hardware. We first show a tight relation between reaction systems and synchronous digital circuits, generally used for digital electronics design. We describe the algorithms allowing us to translate one model to the other one, while keeping the same behavior and similar size. We also develop a compiler translating a reaction systems description into hardware circuit description using field-programming gate arrays (FPGA) technology, leading to high performance, hardware-based simulations of reaction systems. This work also opens a novel interesting perspective of analyzing the behavior of biological systems using established industrial tools from electronic circuits design

Minimizing Reaction Systems

The theoretical model for reaction systems is a relatively new framework originally proposed as a mathematical model for biochemical processes which take place in living cells. Growing interest in this research area has lead to the abstraction of the model for non-biological purpose as well. Reaction systems, with a well understood behavior, have become important for studying transition systems. As with any mathematical model, we want to simplify a given implementation of the model as much as possible while maintaining functional equivalence. This paper discusses the formal model for reaction systems, how we can simplify them with minimization techniques, some of their capabilities and properties, and a comparison of those properties for minimal and non-minimal reaction systems. Original software written for the purpose of exploring reaction systems for this paper as well as well-known logic minimization algorithms instrumental in simplifying reaction systems are discussed

Comparing reactions in reaction systems

Originally, reaction systems were introduced to describe in a formal way the interactions between biochemical reactions taking place in living cells. They are also investigated as an abstract model of interactive computation. A reaction system is determined by a finite background set of entities and a finite set of reactions. Each reaction specifies the entities that it needs to be able to occur, the entities which block its execution, and the entities that it produces if it occurs. Based on the entities available in a state of the system, all reactions of the system that are enabled take place and together produce the entities that form the next state. In this paper we compare reactions in terms of their enabledness and results. We investigate three partial orders on reactions that build on two definitions of equivalence of (sets of) reactions. It is demonstrated how each partial order defines a lattice (with greatest lower bounds and least upper bounds) for all nontrivial reactions. Together, these orders provide an insight in possible redundancies and (re)combinations of the reactions of a reaction system. (C) 2020 Elsevier B.V. All rights reserved.Algorithms and the Foundations of Software technolog