Short List
Abstracts:
September 12, 2000
Models of Brain Function and Consciousness
Deric Bownds, UW Department of Molecular Biology and Zoology
This talk will review some basic aspects of brain function and models for the consciousness of humans and other animals.
September 19, 2000
Climate and the Oceanic Conveyer
Arne Winguth, UW Department of Atmospheric and Oceanic Sciences
The movement of warm salty water to high latitudes of the North Atlantic, the formation of dense North Atlantic Deep Water, and the displacement of water as this water mass exits from the North Atlantic can be considered as a linked system or conveyor belt. Paleoclimatic proxies and model studies indicate that complex nonlinear feedback processes between the atmospheric circulation and the oceanic conveyor belt exist, which have significant effects on the climate of Northern America and Europe. The system seems to be quite sensitive to disturbances, particularly by fresh water inflow into the North Atlantic. Different atmospheric-oceanic feedback mechanisms will be discussed in respect to changes in climate and global biogeochemical cycles.
September 26, 2000
From Butterflies to Prisons: America's Failing War on Drugs
Richard Althouse, Wisconsin Department of Corrections
Political understanding of systems models, complexity and nonlinear dynamics can make the difference between the success or failure of public policy. Single focus solutions in complex systems can result in third order nonlinear (positive feedback) outcomes that drives a system away from stability, making a problem greater rather than smaller. The importance of this kind of knowledge in public policy will be illustrated by applying specific system models and complexity principles to the creation and implementation of America's failing "War on Drugs."
October 3, 2000
Modeling Locomotion in Ascaris
Bob Turner, UW Department of Mathematics
Ascaris suum is a parasitic nematode that lives in pigs' intestines. It is a tempting subject for neurophysiologists in that it is 'simple', having only 298 neurons, about 80 of which are associated with locomotion. The muscular and neural structures are quite well understood, but the means by which they produce locomotion are not. As a step to understanding the locomotion we develop a realistic model for a single Ascaris muscle cell, using data from experiments which have established the types of ionic currents in the muscle cell and many of their kinetic properties. When the various ionic currents are put into a single Hodgkin-Huxley type model, numerical simulations reproduce several aspects of the voltage recordings from individual muscle cells. Extensions of the model which include mechanosensory feedback for linked chains of model cells provide a system which simulates locomotion.
October 10, 2000
Climate Model Uncertainties and Century-Timescale Climate Predictions
Chris Forest, MIT Center for Global Change Science
The climate system, as a nonlinear system, has very high dimensionality and thus, understanding and quantifying its predictability requires simplification of the system, for both conceptual and practical reasons. This issue has led the climate research community to use a range of models, from simple to complex (1D EBM to 3D GCM) to explore behavior ranging from global-mean to regional temperatures. In this talk, I will discuss two methods of ``intermediate complexity'' in both modeling and diagnostics that will be used to assign quantitative answers, in terms of probabilities, to questions regarding uncertainty in predictions of the physical climate system. Because the climate system is not just a physical one, but also is influenced by human activity, we must remember that the total uncertainty in climate predictions is a combined uncertainty from multiple forecasts.
October 17, 2000
Testing the Buddhist Hypothesis: An Artificial Life Simulation of the Buddhist Theory of Agency
Alex Turner, UW Institute for Environmental Studies
The ancient indigenous knowledge system that gave rise to humoral medicine and Buddhist psychology turns out to be quite useful as a design for an artificial life computer simulation, to be demonstrated. Possible applications of the simulation's algorithm include fostering bottom-up development and education in Buddhist Asia, GIS-based indigenous land-use planning and preservation, as well as providing the beginnings of a means of testing the basic hypothesis of Buddhism.
The talk concludes with a brief discussion of future directions for the simulation and related work.
See http://www.execpc.com/~alturner/java/Swarmsara.html
October 24, 2000 (in 5280 Chamberlin)
Searching for the Missing Baryons
Blair D. Savage, UW Department of Astronomy
The theory of the nucleosynthesis of the light elements during the big bang and the interpretation of observations of fluctuations in the cosmic background radiation suggest that the density of normal baryonic matter in the universe greatly exceeds that observed in galaxies. A possible solution to this missing baryon problem is that a substantial portion of the baryons in the universe are hidden in moderately hot intergalactic gas. Recent measurements obtained with the ultraviolet spectrographs on the Hubble Space Telescope and the Far Ultraviolet Spectroscopic Explorer satellite are providing evidence that the intergalactic medium may indeed harbor an important fraction of the baryons in the universe.
October 31, 2000
Symbolic Dynamics of the Fixed-Position, Non-Equilibrium Farmer-Joshi Model
David Albers, UW Department of Physics
I will use symbolic dynamics to investigate chaos and other dynamical properties of an agent-based financial market model. Because of the simplicity of the model, it will be used to gain intuition regarding mechanisms that cause chaos. Out of this will arise methods of arguing for or against the existence of chaos in various circumstances. The goal of the talk will be an intuitive, non-mathematical understanding of chaotic dynamics.
November 7, 2000
Current Compositional Cacophonies Concerning Concepts of Chaos and Complexity Theory
Paula Matthusen, Jeff Snyder and Ryan Smith, UW Department of Music
Ryan Smith, Jeff Snyder, and Paula Matthusen are three composition students applying concepts of Chaos and Complexity Theory to their compositional and performative processes. The three composers will briefly discuss their current works and how they are borrowing these theories. Performances of current works are also being arranged. Music fresh off the press with fresh new ideas for discussion!
November 14, 2000
Karyn Kunzelman, UW Department of Surgery
Computer Modeling of Cardiac Valve Dynamics
November 21, 2000
Physics and Medicine Get Together to Cure Brain Cancer
Gelsomina De Stasio, UW Department of Physics
Malignant brain cancers are expected to affect 35,239 of the 275,306,000 people in the United States in 2000, according to the year 2000 census. These malignant cancers are resistant to currently available therapies, and stimulate the search for new therapeutic strategies, such as neutron capture or radiotherapy, enhanced by a locally accumulated sensitizer.
Gadolinium is a candidate radiosensitizer and neutron capture agent. Gadolinium Neutron Capture Therapy (GdNCT) for brain cancer is so far only a hypothetical therapy, since it has never been tested on human or animal cases. We must find a Gd compound that targets all and only cancer cells, and accumulates in cell nuclei, before it can be suggested for clinical trials. At the UW-Synchrotron Radiation Center we are using an X-ray PhotoElectron Emission Microscope (X-PEEM) to investigate the micro-localization of Gd in brain cancer cells and tissues, to find the right Gd-compound for the therapy. The MEPHISTO X-PEEM, after reaching a resolution of 20 nm, has been extensively used for the last five years. Among the most recent results, we will present the micro-localization of gadolinium in glioblastoma cells in culture and tissue sections. The results obtained with the first Gd-compound tested prove that gadolinium is uptaken in the cancer cell nuclei, as necessary for GdNCT, in the in vitro case, while in vivo only 20% of the tumor exhibits Gd. Therefore new Gd-compounds must be tested, in collaboration with UW-Human Oncology, before GdNCT can become a real therapy. These experiments demonstrate the need for close collaboration of physicists and medical doctors to address the elusive goal of curing malignant brain cancers.
A brief overview of other experiments will include the microchemistry of bacteria, rocks, colossal magnetoresistive materials, tribology and archaeology specimens, demonstrating the interdisciplinarity of our approach.
November 28, 2000
Why do Stars and Planets have Magnetic Fields?
Cary B. Forest, UW Department of Physics
The Earth and other planets, the Sun and other stars, and perhaps even the Galaxy have magnetic fields generated by complex turbulent flows of conducting fluids or plasmas. These phenomena are known collectively as geophysical or astrophysical dynamos. In this seminar, I will present heuristic pictures of how magnetic fields can be spontaneously generated by flows of conducting fluids. Then, I will discuss how the saturation process of the dynamo (which ultimately determines the strength of the self generated magnetic field) is a non-linear process in which the self generated magnetic field acts back on the flow which produced it. Finally, I will describe an experiment under construction at the University of Wisconsin which is designed to produce a dynamo in the laboratory for study.
December 5, 2000
The Reason/Unreason Project: Gravity, Complexity, Poetry
Judith Strasser, Wisconsin Public Radio (retired)
For the past three months, Judith Strasser has been a Fellow at the Wurlitzer Foundation in Taos, New Mexico, beginning work on a book-length manuscript of poems that consider the relationships between reason and unreason, science and art, physics and faith. In this talk, she will share some of her poems (including "The Rails, Removed," recently published in Poetry magazine, which was inspired by a Chaos & Complex Systems Seminar last year) and describe her visits to the Santa Fe Institute and other sites of poetic inspiration.
Judith Strasser recently retired as a producer and interviewer for the nationally-syndicated public radio program TO THE BEST OF OUR KNOWLEDGE, to pursue a career as a poet and freelance writer. Her poems have appeared in many literary magazines, including Poetry, Nimrod, and The Kenyon Review.
December 12, 2000
Large-Scale Structures from Small-Scale Disorder in Geophysical Flows
Leslie Smith, UW Department of Mathematics
In models of atmospheric and oceanic flows, such as models for
weather
prediction, small-scale motions are parameterized as a sink of
energy,
that is, to remove energy from larger scales. In this talk,
we
will
explain why this might make sense in an isotropic world, but not
in the
real world. We show that small-scale turbulence can actually
generate
the large-scale structures that we see in geophysical flows, such
as
cyclones
and eastward jets.