Foundations ∩ StructureInformation and Uncertainty

in the Sciences

Richard M. MurrayControl and Dynamical Systems

California Institute of Technology

OutlineI. Dynamics and Feedback in NatureII. Some Overarching ThemesIII. Example: Synthetic BiologyIV. Some Thoughts on Going Forward

Connections, 15 Jul 04 R. M. Murray, Caltech 2

Biological Systems

“Systems Biology”Many molecular mechanisms for biological organisms are characterizedMissing piece: understanding of how network interconnection creates robust behavior from uncertain components in an uncertain environmentTransition from organisms as genes, to organisms as networks of integrated chemical, electrical, fluid, and structural elements

Key features of biological systemsIntegrated control, communications, computingReconfigurable, distributed control, at molecular level

Design and analysis of biological systemsApply engineering principles to biological systemsSystems level analysis is requiredProcessing and flow of information is key

Connections, 15 Jul 04 R. M. Murray, Caltech 3

Ecological Systems

Populations and ecosystemsExample: bacterial networksMultiple layers of feedback ⇒ complexityGet robust functionality to individual cellAnd system level robustness for colonyQ: how does evolution shape this?

Fire managementPower law distributions ⇒ many existing tools are not appropriateMulti-scale behavior: fuel to atmosphereQ: prevention, planning, policy?

Role of Dynamics and FeedbackMulti-scale dynamicsRobust yet fragile behavior

Connections, 15 Jul 04 R. M. Murray, Caltech 4

Physics: Quantum and Geophysical Systems

Quantum SystemsRational design and empirical optimization of open loop control strategies (eg, NMR)Real-time feedback methodology for controlling quantum systemsRole of interconnection is critical and very different from most engineering applications

Geophysical Systems (earthquakes)Reduced order models emerging for non-crystalline solids, soils, and related geo-physical materials that explain complex physical behaviors Extreme multi-scale behavior of interconnected components

Connections, 15 Jul 04 R. M. Murray, Caltech 5

Overarching Themes

Multiscale modeling, analysis and computation

rigorous techniques for model reduction and efficient, robust simulation becoming essential

Feedback as a tool for uncertainty management

feedback as a fundamental organizing principleenables ``network robustness''

Integrated communication, computing and controlnature uses dramatically different mechanisms to communicate andprocess information

Current tools not capable of addressing many interesting problems

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Example: Synthetic Biology

MIT Bio-Bricks program

Crawling Neutrophil “Chasing” a Bacterium Human polymorphonuclear leukocyte (neutrophil) on blood filmRed blood cells are dark in color, principally spherical shape. Neutrophil is "chasing" Staphylococcus aureus micro-organisms, added to film.

Tom Stossel, June 22, 1999 (John Stossel, 195?)http://expmed.bwh.harvard.edu/projects/motility/neutrophil.html

Synchronization of a repressilator, IAP ‘03

7 Jan

14 Jan

Elowitz and Lieber, 2000

21 Jan

28 Jan

Elowitz and Lieber, 2000

Connections, 15 Jul 04 R. M. Murray, Caltech 7

Synthetic Biology Competition 2004

Boston U, Caltech, MIT, Princeton, U TexasCaltech: 7 undergrads + 3 grad students + 3 facultyProject #1: alternative oscillator designsProject #2: serial counter with digital readout

Features:

Multiscale dynamics

Uncertainty manage-ment via feedback

Integrated commun-ication, computing and control

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New CDS research is requiredIntegration of computing, communications, control“High risk” applications in biology, quantum, geophysics, ecosystemsMaintain rigorous mathematical approach

New approach to educationMake CDS tools accessible to broad audience of scientists and engineersProvide training required to work on interdisciplin-ary applications in science and engineering

Foundations ∩ StructureInformation and Uncertainty

in the Sciences