Rosen's (M,R) System in Process Algebra

Total Page:16

File Type:pdf, Size:1020Kb

Rosen's (M,R) System in Process Algebra Rosen’s (M,R) system in process algebra Gatherer and Galpin Gatherer and Galpin BMC Systems Biology 2013, 7:128 http://www.biomedcentral.com/1752-0509/7/128 Gatherer and Galpin BMC Systems Biology 2013, 7:128 http://www.biomedcentral.com/1752-0509/7/128 RESEARCH ARTICLE Open Access Rosen’s (M,R) system in process algebra Derek Gatherer1,3* and Vashti Galpin2 Abstract Background: Robert Rosen’s Metabolism-Replacement, or (M,R), system can be represented as a compact network structure with a single source and three products derived from that source in three consecutive reactions. (M,R) has been claimed to be non-reducible to its components and algorithmically non-computable, in the sense of not being evaluable as a function by a Turing machine. If (M,R)-like structures are present in real biological networks, this suggests that many biological networks will be non-computable, with implications for those branches of systems biology that rely on in silico modelling for predictive purposes. Results: We instantiate (M,R) using the process algebra Bio-PEPA, and discuss the extent to which our model represents a true realization of (M,R). We observe that under some starting conditions and parameter values, stable states can be achieved. Although formal demonstration of algorithmic computability remains elusive for (M,R), we discuss the extent to which our Bio-PEPA representation of (M,R) allows us to sidestep Rosen’s fundamental objections to computational systems biology. Conclusions: We argue that the behaviour of (M,R) in Bio-PEPA shows life-like properties. Keywords: Robert Rosen, (M,R), Metabolism-replacement, Metabolism-repair, Relational biology, Process algebra, Bio-PEPA, Computability, Turing machine Background kind. By contrast, relational biologists define complex Relational biology is a discipline founded by Robert systems as only those systems having impredicative (self- Rosen (1934–1998) [1-3], based on the previous work of referencing) components, and claim that these systems Nicolas Rashevsky (1899–1972), which considers bio- are non-computable as functions by Turing machines. For logical network structures using the mathematical tools relational biologists, complex systems are therefore quali- of category theory. Relational biology might be consid- tatively different to simple ones. ered a branch of systems biology, in that it studies the A Turing machine is a formal mathematical model of same objects as systems biology, and for similar reasons, computation, which has a notion of its internal state, an namely to improve our understanding of how complex unbounded tape and a read-write head for that tape [4]. biological processes work. However, its methods and It also has a table to determine the next internal state, conclusions are so radically different to those of conven- the symbol to be written to the tape and the direction in tional systems biology that one might almost say it con- which to move the head, all of which depend on the stitutes an alternative discourse on the subject. Systems current internal state and the current symbol. The con- biologists attempt to represent biological network sys- cept of the unbounded tape may be taken to imply limit- tems as software objects for simulation on computers. less time and space for computation. A function is These network structures may vary in their degree of (Turing-) computable if it can be evaluated by a Turing complexity, but the difference between simple and com- machine which, when given an input to the function, plex networks is treated as one of degree rather than of eventually writes the value of the function for that input on its output tape, assuming that the function is defined for the input. No time bound can be imposed on how * Correspondence: [email protected] long the Turing machine will take to output the value. 1MRC-University of Glasgow Centre for Virus Research, 8 Church Street, Glasgow G11 5JR, UK An adequate exposition of the logic of relational biol- 3Present address: Biomedical & Life Sciences, Lancaster University, Lancaster ogy is impossible within the limits of a research paper. LA1 4YQ, UK The strategy adopted here is therefore to concentrate on Full list of author information is available at the end of the article © 2013 Gatherer and Galpin; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Gatherer and Galpin BMC Systems Biology 2013, 7:128 Page 2 of 10 http://www.biomedcentral.com/1752-0509/7/128 Rosen’s Metabolism-Repair/Replacement system, conven- tionally abbreviated in brackets as (M,R), a very small, but nevertheless allegedly non-computable, network which is the central object of study in modern relational biol- ogy. Metabolism-Repair was Rosen’s own phrase, but Metabolism-Replacement is used here for reasons given by previous authors [5]. Readers interested in the con- struction of (M,R), and in particular the reasons why it is deemed to be non-computable, are referred to Louie’s re- cent book [6], and for contextual material to Rosen’s pre- vious book [7] and the recent series of reviews [5,8-11]. Only the briefest description of (M,R) is given in the fol- lowing paragraphs, referring to Figures 1 and 2, which illustrate (M,R) in two ways. Figure 2 The Goudsmit representation of (M,R) [15]. Black lines Relational biologists argue that the non-computability are metabolic productive reactions. Red dotted lines represent of (M,R) by Turing machines is achieved through a circu- catalysis – for instance f catalyses the production of B from A. Compare with Figure 1, to which this figure is equivalent. lar pathway of causal relations, termed closure to efficient causation [7]. Furthermore relational biologists seek to demonstrate that such non-computable systems, when represented as graphs, may be surprisingly small in terms have used them [12]. The abstract graph structures de- of their total number of nodes and edges. Relational biolo- veloped by relational biologists are referred to as models, gists do not deny that complex systems can be simulated, and a modelling relation is achieved between a system in but maintain that they can never truly be computed as the natural world and a model in the mathematical world functions [6,7,12]. Since even the most advanced com- when their entailment structures, meaning the totality of puters still use Turing architecture (i.e. they are random their internal causal relations, are identical. Entailment is access stored program machines that are almost Turing an important concept in relational biology. When a certain machine equivalent), the full computational analysis of pattern of system states necessarily results in a certain out- complex biological systems is therefore postulated to be come, it is said that this outcome is entailed by that cause. beyond our current computing abilities. Relational biologists describe logical entailments in their Relational biology has therefore concentrated its ef- mathematical work that represent entailments from the forts into pure mathematics to the exclusion of compu- physical world and insist, for a correct modelling relation tational analysis. Rosen once quipped that his mentor, to be obtained, that these entailments must occur in the Rashevsky, had lived in a time when computers were not model. A simulation, by contrast, represents the world in easily accessible but, even if they had been, he would not a much more approximate way than a model, without the requirement for congruence of internal causal relations. A simulation may be an excellent predictive tool for the nat- ural world, but when it goes wrong one may have no idea why, since its entailment structure is largely a work of cre- ative approximation. Relational biologists maintain that much of conventional systems biology is merely about the development of such approximate simulations [6,7,12]. Rosen also argued that a corollary of the non- computability of complex systems is the fact that they are also non-reducible to their component reactions, in that a model of a complex system cannot be constructed sim- ply by an additive assembly of smaller models of that sys- tem’s individual reaction components [7]. By contrast, M,R Figure 1 The Louie-Kercel representation of ( ) [10]. Lines whatever claims that systems biologists may make about with open arrowheads are metabolic productive reactions, for instance A produces B. Lines with filled arrowheads represent their own anti-reductionism [13], the construction of catalysis. Conventionally these point to the substrate of a metabolic software representations of biological networks requires reaction. For instance f catalyses the production of B from A, and the individual representation of component reactions in this is indicated by f pointing to A. Likewise, Φ catalyses the production code, in effect a reduction at the software level. Relational of f from B, so an open-headed arrow goes from B to f, and a filled biologists acknowledge that there are many systems that arrow from Φ to B. are reducible and algorithmically computable in this way, Gatherer and Galpin BMC Systems Biology 2013, 7:128 Page 3 of 10 http://www.biomedcentral.com/1752-0509/7/128 but none of these are truly complex, and therefore few Rosen intended (M,R) to be interpreted very generally, are really interesting from a biological point of view. A as a representation of a whole metabolic system B pro- further point of disagreement concerns the issue of duced from an entire set of nutrient sources A. Meta- mechanism. Systems biologists, and molecular biologists bolic activity in B is catalysed by a set of enzymatic in general, view biological processes as machine-like.
Recommended publications
  • COMPLEX SYSTEMS BIOLOGY and HEGEL's PHILOSOPHY Kazuyuki
    COMPLEX SYSTEMS BIOLOGY AND HEGEL’S PHILOSOPHY Kazuyuki Ikko Takahashi KandaSurugadai 1-1, Chiyoda, Tokyo 101-8301, Meiji University ABSTRACT In this study I will argue that Hegel’s philosophy has similarity to the self- organization theories of Prigogine and Kauffman and complex systems biology of Kaneko, and is therefore an idea in advance of its times. In The Philosophy of Nature, Hegel’s interest is in how nature evolves through the mechanism of self-organization. He was writing before Darwin proposed the theory of evolution, and his dialectic is aimed at analyzing and describing development in the logical sense. The important feature of this work is their analysis of the fundamental structures by which order is generated. Hegel struggled to produce the concept of life from that of matter. He proposed that matter should develop into organism, but only in a logical sense. Nature itself is a system of producing spontaneous order through the random motion of the contingent. Then Hegel tackles living things. He would like to say that the basis of life is the non-equilibrium self-referential structure. In more modern terminology, we could interpret this as meaning that the first organism emerged from interaction between high polymers. Living creatures exhibit flexibility and plasticity through fluctuations in these elements. Complex systems biology uses a dynamical systems approach to explain how living things acquire diversity, stability and spontaneity. First, simple single-celled organisms arose through interactions between proteins and nucleic acids. These are the archae-bacteria in modern terminology. Next, the development of eukaryote cells from the prokaryotes is explained by symbiogenesis or endosymbiotic theory.
    [Show full text]
  • Complex Systems Analysis of Arrested Neural Cell Differentiation During Development and Analogous Cell Cycling Models in Carcinogenesis
    [04-01-2012 Preprint Update] Complex Systems Analysis of Arrested Neural Cell Differentiation during Development and Analogous Cell Cycling Models in Carcinogenesis V. I. Prisecaru and I.C. Baianu AFC-NMR & NIR Microspectroscopy Facility, College of ACES, FSHN & NPRE Departments, University of Illinois at Urbana, Urbana, IL. 61801, USA Email address: ibaianu @illinois.edu 1.Introduction A new approach to the modular, complex systems analysis of nonlinear dynamics of arrested neural cell Differentiation--induced cell proliferation during organismic development and the analogous cell cycling network transformations involved in carcinogenesis is proposed. Neural tissue arrested differentiation that induces cell proliferation during perturbed development and Carcinogenesis are complex processes that involve dynamically inter-connected biomolecules in the intercellular, membrane, cytosolic, nuclear and nucleolar compartments. Such 'dynamically inter-connected' biomolecules form numerous inter- related pathways referred to as 'molecular networks'. One such family of signaling pathways contains Nature Precedings : hdl:10101/npre.2012.7101.2 Posted 2 Apr 2012 the cell cyclins. Cyclins are proteins that link several critical pro-apoptotic and other cell cycling/division components, including the tumor suppressor gene TP53 and its product, the Thomsen-Friedenreich antigen (T antigen), Rb, mdm2, c-Myc, p21, p27, Bax, Bad and Bcl-2, which play major roles in various neoplastic transformations of many tissues. 1. Arrested Cell Differentiation in Neural
    [Show full text]
  • Systems Biology 1 Systems Biology
    Systems biology 1 Systems biology Systems biology is a term used to describe a number of trends in bioscience research, and a movement which draws on those trends. Proponents describe systems biology as a biology-based inter-disciplinary study field that focuses on complex interactions in biological systems, claiming that it uses a new perspective (holism instead of reduction). Particularly from year 2000 onwards, the term is used widely in the biosciences, and in a variety of contexts. An often stated ambition of An attempted illustration of the systems approach to biology systems biology is the modeling and discovery of emergent properties, properties of a system whose theoretical description is only possible using techniques which fall under the remit of systems biology. These typically involve cell signaling networks, via long-range allostery[1]. Overview Systems biology can be considered from a number of different aspects: • As a field of study, particularly, the study of the interactions between the components of biological systems, and how these interactions give rise to the function and behavior of that system (for example, the enzymes and metabolites in a metabolic pathway).[2][3] • As a paradigm, usually defined in antithesis to the so-called reductionist paradigm (biological organisation), although fully consistent with the scientific method. The distinction between the two paradigms is referred to in these quotations: "The reductionist approach has successfully identified most of the components and many of the interactions but, unfortunately, offers no convincing concepts or methods to understand how system properties emerge...the pluralism of causes and effects in biological networks is better addressed by observing, through quantitative measures, multiple components simultaneously and by rigorous data integration with mathematical models" Sauer et al[4] "Systems biology...is about putting together rather than taking apart, integration rather than reduction.
    [Show full text]
  • FOOTPRINTS of GENERAL SYSTEMS THEORY Aleksandar Malecic Faculty of Electronic Engineering University of Nis, Serbia Aleks.Maleci
    FOOTPRINTS OF GENERAL SYSTEMS THEORY Aleksandar Malecic Faculty of Electronic Engineering University of Nis, Serbia [email protected] ABSTRACT In order to identify General Systems Theory (GST) or at least have a fuzzy idea of what it might look like, we shall look for its traces on different systems. We shall try to identify such an “animal” by its “footprints”. First we mention some natural and artificial systems relevant for our search, than note the work of other people within cybernetics and identification of systems, and after that we are focused on what unification of different systems approaches and scientific disciplines should take into account (and whether or not it is possible). Axioms and principles are mentioned as an illustration of how to look for GST*. A related but still separate section is about Len Troncale and linkage propositions. After them there is another overview of different kinds of systems (life, consciousness, and physics). The documentary film Dangerous Knowledge and ideas of its characters Georg Cantor, Ludwig Boltzmann, Kurt Gödel, and Alan Turing are analyzed through systems worldview. “Patterns all the way down” and similar ideas by different authors are elaborated and followed by a section on Daniel Dennett’s approach to real patterns. Two following sections are dedicated to Brian Josephson (a structural theory of everything) and Sunny Auyang. After that the author writes about cosmogony, archetypes, myths, and dogmas. The paper ends with a candidate for GST*. Keywords: General Systems Theory, unification, patterns, principles, linkage propositions SYSTEMS IN NATURE AND ENGINEERING The footprints manifest as phenomena and scientific disciplines.
    [Show full text]
  • Minireview Challenges for Complex Microbial Ecosystems: Combination of Experimental Approaches with Mathematical Modeling
    Microbes Environ. Vol. 28, No. 3, 285–294, 2013 https://www.jstage.jst.go.jp/browse/jsme2 doi:10.1264/jsme2.ME13034 Minireview Challenges for Complex Microbial Ecosystems: Combination of Experimental Approaches with Mathematical Modeling SHIN HARUTA1, TAKEHITO YOSHIDA2, YOSHITERU AOI3,4, KUNIHIKO KANEKO5, and HIROYUKI FUTAMATA6* 1Department of Biological Sciences, Graduate School of Science and Engineering, Tokyo Metropolitan University, 1–1 Minami-Osawa, Hachioji, Tokyo 192–0397, Japan; 2Department of General Systems Studies, University of Tokyo 3–8–1 Komaba, Meguro, Tokyo 153–8902, Japan; 3Institute for Sustainable Sciences and Development, Hiroshima University, 2–113 Kagamiyama, Higashi-Hiroshima, Hiroshima 739–8527, Japan; 4Department of Biology, Northeastern University, 360 Huntington Ave. Mugar Lifescience Bldg., Boston, MA 02115, USA; 5Research Center for Complex Systems Biology, University of Tokyo, Meguro-ku, Tokyo, 153–8902, Japan; and 6Department of Applied Chemistry and Biochemical Engineering, Graduate School of Engineering, Shizuoka University, Hamamatsu, 432–8561, Japan (Received March 12, 2013—Accepted June 7, 2013—Published online August 30, 2013) In the past couple of decades, molecular ecological techniques have been developed to elucidate microbial diversity and distribution in microbial ecosystems. Currently, modern techniques, represented by meta-omics and single cell observations, are revealing the incredible complexity of microbial ecosystems and the large degree of phenotypic variation. These studies propound that microbiological techniques are insufficient to untangle the complex microbial network. This minireview introduces the application of advanced mathematical approaches in combination with microbiological experiments to microbial ecological studies. These combinational approaches have successfully elucidated novel microbial behaviors that had not been recognized previously. Furthermore, the theoretical perspective also provides an understanding of the plasticity, robustness and stability of complex microbial ecosystems in nature.
    [Show full text]
  • JUNE: Open-Source Individual-Based Epidemiology Simulation
    medRxiv preprint doi: https://doi.org/10.1101/2020.12.15.20248246; this version posted December 16, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY-NC-ND 4.0 International license . JUNE open-source individual-based epidemiology simulation Joseph Bullock1,2,*, Carolina Cuesta-Lazaro1,3,*, Arnau Quera-Bofarull1,3,*, Miguel Icaza-Lizaola1,3,**, Aidan Sedgewick1,4,**, Henry Truong1,2,**, Aoife Curran1,3, Edward Elliott1,3, Tristan Caulfield7, Kevin Fong8,9, Ian Vernon1,6, Julian Williams5, Richard Bower1,3, and Frank Krauss1,2,+ 1 Institute for Data Science, Durham University, Durham DH1 3LE, UK 2Institute for Particle Physics Phenomenology, Durham University, Durham DH1 3LE, UK 3Institute for Computational Cosmology, Durham University, Durham DH1 3LE, UK 4Centre for Extragalactic Astronomy, Durham University, Durham DH1 3LE, UK 5Institute for Hazard, Risk & Resilience, Durham University, Durham DH1 3LE, UK 6Department of Mathematical Sciences, Durham University, Durham DH1 3LE, UK 7Department of Computer Science, University College of London, London WC1E 6BT, UK 8Department of Science, Technology, Engineering and Public Policy, University College London, London WC1E 6BT, UK 9Department of Anaesthesia, University College London Hospital, London NW1 2BU, UK *Equal contribution **Equal contribution +Corresponding author: [email protected] Abstract: We introduce JUNE, an open-source framework for the detailed simulation of epi- demics on the basis of social interactions in a virtual population constructed from geographically granular census data, reflecting age, sex, ethnicity, and socio-economic indicators.
    [Show full text]
  • Systems Biology Success Stories In
    SUCCESS STORIES IN SYSTEMS BIOLOGY Project funded by the European Comission under the Seventh Framework Programme for Research and Technological Development Contents Welcome 2 Research 3 A model that gets to the heart of systems biology 3 Denis Noble, Oxford University Taking a systems-eye view of cancers in children 5 Walter Kolch, Systems Biology Ireland Systems biology study points to Turing model of finger formation 7 James Sharpe, Centre for Genomic Regulation Balancing flavour and texture in tomatoes - with systems biology 9 Stuart Dunbar, Syngenta Systems X.ch: Swiss bank on systems biology 11 Daniel Vonder Muehll, SystemsX, Gisou van der Goot, EPF Lausanne, Cris Kuhlemeier, University of Bern Answering big questions with a small bug 13 Luis Serrano, Centre for Genomic Regulation Blueprints for life 15 Bas Teusink, Netherlands Platform for Systems Biology Merrimack: Following a systems path to drug discovery 17 Peter Sorger, Massachusetts Institute of Technology, and Birgit Schoeberl, Merrimack Pharmaceuticals Beating the conundrum of variability in cardiac simulations 19 Blanca Rodriguez, Oxford University Stats and modelling – a Belgian diagnostic tool for arthritis 21 Thibault Helleputte, DNAlytics Virtual Liver Network: a collaborative solution to hepatic diseases 23 Adriano Henney, Virtual Liver Network Tools and Resources 25 SBML: A lingua franca for systems biology 25 Michael Hucka, California Institute of Technology Model Support: JWS Online and BioModels Database 27 Jacky Snoep, Stellenbosch University, and Henning Hermjakob,
    [Show full text]
  • The Challenges Facing Systemic Approaches in Biology: an Interview with Kunihiko Kaneko
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE PERSPECTIVE ARTICLE published: 05 December 2011 provided by PubMed Central doi: 10.3389/fphys.2011.00093 The challenges facing systemic approaches in biology: an interview with Kunihiko Kaneko Kunihiko Kaneko* Research Center for Complex Systems Biology, University of Tokyo, Tokyo, Japan Edited by: Interviewed by Kumar Selvarajoo and MasaTsuchiya at Institute for Advanced Biosciences, Kumar Selvarajoo, Keio University, Keio University, Japan, I discuss my approach to biology, what I call complex systems biol- Japan ogy. The approach is constructive in nature, and is based on dynamical systems theory Reviewed by: Kumar Selvarajoo, Keio University, and statistical physics. It is intended to understand universal characteristics of life sys- Japan tems; generic adaptation under noise, differentiation from stem cells in interacting cells, Masa Tsuchiya, Keio University, Japan robustness and plasticity in evolution, and so forth. Current status and future directions in *Correspondence: systems biology in Japan are also discussed. Kunihiko Kaneko, Research Center for Complex Systems Biology, University Keywords: plasticity, adaptation, robustness, stem cell, noise of Tokyo, Meguro, Komaba, Tokyo 153-8902, Japan. e-mail: [email protected]. ac.jp Q1: PROFESSOR KANEKO, CAN YOU INTRODUCE YOURSELF for the Logic of Life as a Complex System” (1999–2004) and AND YOUR RESEARCH? the ERATO project ”Kaneko Complex Systems Biology” (2004– I have been a physicist, and although I am more and more involved 2010), and am a head of Center for Complex Systems Biology at in biology now, I think my approach is quite a physicist-type.
    [Show full text]
  • Meeting New Challenges in Food Science Technology: the Development of Complex Systems Approach for Food and Biobased Research
    Meeting new challenges in food science technology: the development of complex systems approach for food and biobased research Hugo de Vries, Monique Axelos, Pascale Sarni-Manchado, Michael O’Donohue To cite this version: Hugo de Vries, Monique Axelos, Pascale Sarni-Manchado, Michael O’Donohue. Meeting new chal- lenges in food science technology: the development of complex systems approach for food and biobased research. Innovative Food Science and Emerging Technologies, Elsevier, 2018, 46, pp.1-6. 10.1016/j.ifset.2018.04.004. hal-01837847 HAL Id: hal-01837847 https://hal.archives-ouvertes.fr/hal-01837847 Submitted on 26 May 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Distributed under a Creative Commons Attribution| 4.0 International License Accepted Manuscript Meeting new challenges in food science technology: the development of complex systems approach for food and biobased research Hugo de Vries, Monique Axelos, Pascale Sarni-Manchado, Michael O'Donohue PII: S1466-8564(18)30422-3 DOI: doi:10.1016/j.ifset.2018.04.004 Reference: INNFOO 1965 To appear in: Innovative Food Science and Emerging Technologies Please cite this article as: Hugo de Vries, Monique Axelos, Pascale Sarni-Manchado, Michael O'Donohue , Meeting new challenges in food science technology: the development of complex systems approach for food and biobased research.
    [Show full text]
  • COMPLEX SYSTEMS BIOLOGY of MAMMALIAN CELL CYCLE SIGNALING in CANCER by JAYANT AVVA Submitted in Partial Fulfillment of the Requi
    COMPLEX SYSTEMS BIOLOGY OF MAMMALIAN CELL CYCLE SIGNALING IN CANCER by JAYANT AVVA Submitted in partial fulfillment of the requirements For the degree of Doctor of Philosophy Dissertation Advisor: Dr. Sree N. Sreenath Department of Electrical Engineering and Computer Science CASE WESTERN RESERVE UNIVERSITY May, 2011 CASE WESTERN RESERVE UNIVERSITY SCHOOL OF GRADUATE STUDIES We hereby approve the thesis/dissertation of JAYANT AVVA candidate for the PhD degree *. (signed) SREE N. SREENATH (chair of the committee) KENNETH A. LOPARO VIRA CHANKONG MIHAJLO D. MESAROVIC JAMES W. JACOBBERGER (date) 12/01/2010 *We also certify that written approval has been obtained for any proprietary material contained therein. Copyright © 2011 by Jayant Avva All rights reserved Table of Contents LIST OF TABLES .................................................................................................vi LIST OF FIGURES .............................................................................................. vii ACKNOWLEDGEMENTS .....................................................................................xi ABSTRACT ........................................................................................................ xiii 1. INTRODUCTION ....................................................................................... 1 1.1. Overview ................................................................................................. 1 1.2. Chapter Organization .............................................................................
    [Show full text]
  • Complex Systems Theory and Biodynamics Complexity, Emergent Systems and Complex Biological Systems
    Complex Systems Theory and Biodynamics Complexity, Emergent Systems and Complex Biological Systems PDF generated using the open source mwlib toolkit. See http://code.pediapress.com/ for more information. PDF generated at: Tue, 09 Jun 2009 07:58:48 UTC System 2 Complex Systems Theory System System (from Latin systēma, in turn from Greek σύστημα systēma) is a set of interacting or interdependent entities, real or abstract, forming an integrated whole. The concept of an 'integrated whole' can also be stated in terms of a system embodying a set of relationships which are differentiated from relationships of the set to other elements, and from relationships between an element of the set and elements not a part of the relational regime. The scientific research field which is engaged in the study of the general A schematic representation of a closed system and its properties of systems include systems boundary theory, systems science, systemics and systems engineering. They investigate the abstract properties of the matter and organization, searching concepts and principles which are independent of the specific domain, substance, type, or temporal scales of existence. Most systems share the same common characteristics. These common characteristics include the following • Systems are abstractions of reality. • Systems have structure which is defined by its parts and their composition. • Systems have behavior, which involves inputs, processing and outputs of material, information or energy. • Systems have interconnectivity, the various parts of a system have functional as well as structural relationships between each other. The term system may also refer to a set of rules that governs behavior or structure.
    [Show full text]
  • A Framework for Evolutionary Systems Biology Laurence Loewe
    BMC Systems Biology BioMed Central Correspondence Open Access A framework for evolutionary systems biology Laurence Loewe Address: Centre for Systems Biology at Edinburgh, The University of Edinburgh, Darwin building, Kings Buildings, Mayfield Road, Edinburgh, Scotland, EH9 3JU, UK Email: Laurence Loewe - [email protected] Published: 24 February 2009 Received: 1 July 2008 Accepted: 24 February 2009 BMC Systems Biology 2009, 3:27 doi:10.1186/1752-0509-3-27 This article is available from: http://www.biomedcentral.com/1752-0509/3/27 © 2009 Loewe; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Background: Many difficult problems in evolutionary genomics are related to mutations that have weak effects on fitness, as the consequences of mutations with large effects are often simple to predict. Current systems biology has accumulated much data on mutations with large effects and can predict the properties of knockout mutants in some systems. However experimental methods are too insensitive to observe small effects. Results: Here I propose a novel framework that brings together evolutionary theory and current systems biology approaches in order to quantify small effects of mutations and their epistatic interactions in silico. Central to this approach is the definition of fitness correlates that can be computed in some current systems biology models employing the rigorous algorithms that are at the core of much work in computational systems biology.
    [Show full text]