Published recently in the Artificial Life XII Proceedings of the Twelfth International Conference on the Synthesis and Simulation of Living Systems . The abstract:
There are deep underlying similarities between Rosen’s (M,R) systems as a definition of life and the RAF sets (Reflexive Autocatalytic systems generated by a Food source) introduced by Hordijk and Steel as a way of analyzing autocatalytic sets of reactions. Using RAF concepts we have systematically explored the set of possible small idealized metabolic networks, searching for instances of (M,R) systems. This exhaustive search has shown that the central requirement of Rosen’s framework, unicity of Φ, becomes harder and harder to obtain as the network grows in size. In addition, we give an expression for operators f, β and in terms of RAF sets.
The Proceedings are available as an Open Access e-book from MIT Press here.
 Jaramillo, S., Honorato-Zimmer, R., Pereira, U., Contreras, D., Reynaert, B., Hernández, V., Soto-Andrade, J., Cárdenas, M.L., Cornish-Bowden, A., Letelier, J. C. 2010. “(M,R) Systems and RAF Sets: Common Ideas, Tools and Projections”. Proceedings of the Twelfth International Conference on the Synthesis and Simulation of Living Systems.
 2010. Proceedings of the Twelfth International Conference on the Synthesis and Simulation of Living Systems. MIT Press. ISBN-10:0-262-29075-8 ISBN-13:978-0-262-29075-3