Language and Genetics

Does DNA work on the same principles the mind works? This is the corageous proposition of some authorities in the filed of Neurobiology like Gustav Stent, and Informatics, my friend Giuseppe Trautteur. ABSTRACT We study a restricted version of Shannon's general purpose analog computer in which we only allow the machine to solve linear differential equations. We show that if this computer is allowed to sense inequalities in a differentiable way, then it can compute exactly the elementary functions, the smallest known recursive class closed under time and space complexity. Furthermore, we show that if the machine has access to a function f(x) with a suitable growth as x goes to infinity, then it can compute functions on any given level of the Grzegorczyk hierarchy. More precisely, we show that the model contains exactly the nth level of the Grzegorczyk hierarchy if it is allowed to solve n - 3 non-linear differential equations of a certain kind. Therefore, we claim that, at least in this region of the complexity hierarchy, there is a close connection between analog complexity classes, the dynamical systems that compute them, and classical sets of subrecursive functions. Modelling biochemical pathways through enhanced π-calculus Source Theoretical Computer Science archiveVolume 325 , Issue 1 (September 2004) table of contentsSpecial issue: Computational systems biology Pages: 111 - 140 Year of Publication: 2004 ISSN:0304-3975 Authors M. Curti Dipartimento di Informatiea, Università di Pisa, Via Filippo Buonarroti, 2, I-56127 Pisa, Italy and Dipartimento di Informatica, Università di Pisa, Via Sommarive, 14, Povo, TN I-38050, Italy P. Degano Dipartimento di Informatiea, Università di Pisa, Via Filippo Buonarroti, 2, I-56127 Pisa, Italy C. Priami Dipartimento di Informatica e Telecomunicazioni, Università di Trento, Via Sommarive, 14, I-38050 Povo, TN, Italy C. T. Baldari Dipartimento di Biologia Evolutiva, Università di Siena, Via Mattioli, 4, I-53100 Siena, Italy Publisher Elsevier Science Publishers Ltd. Essex, UK Bibliometrics Downloads (6 Weeks): n/a, Downloads (12 Months): n/a, Citation Count: 8 Additional Information: abstract references cited by index terms collaborative colleagues Tools and Actions: Review this Article Save this Article to a Binder Display Formats: BibTeX EndNote ACM Ref DOI Bookmark: 10.1016/j.tcs.2004.03.066 ABSTRACT We use the π-calculus to model the evolution of biochemical systems, taking advantage of their similarities with global computation applications. First, we present a reduction semantics for the π-calculus from which causality and concurrency can be mechanically derived. We prove that our semantics agrees with the causal definitions presented in the literature. We also extend our semantics to model biological compartments. Then, we show the applicability of our proposal on a couple of biological examples.