Madison Chaos and Complex Systems Seminar

Fall 2009 Seminars

All seminars are Tuesday at 12:05 pm in 4274 Chamberlin except as noted. Refreshments will be served

Short List

Abstracts

September 8, 2009

HIV/AIDS, What we know and how we learned it

Pete Cohen, UW Department of Medicine

AIDS/HIV disease is arguably the most important disease in the world.  I will attempt in 45 minutes to review how current understanding of how the disease evolved.


September 15, 2009

Long-term cortical and subcortical neuromodulation induced by electrical tongue stimulation

Joe Wildenberg, UW Department of Neuroscience

The use of electrical neurostimulation to treat neurological disorders is expanding from initial applications in epilepsy and Parkinson’s disease to conditions such as depression, obsessive-compulsive disorder, balance disorders, and as an adjuvant to behavioral therapy during neurorehabilitation for stroke.  Our group has developed a non-invasive technique that stimulates the central nervous system through the tongue.  Previous work has shown this technique efficacious as therapy for balance disorders with beneficial effects lasting weeks to months after the stimulation therapy has ended.  Here I will present a functional magnetic resonance imaging study indicating that stimulation of the cranial nerves via afferents in the tongue can influence neural structures within the balance-processing network to produce positive behavioral effects.  Furthermore, the results of this study indicate that this stimulation can modify neural processing of tasks not encountered during the stimulation sessions.  This seems to be the first evidence of long-term network-wide processing plasticity induced by electrical neurostimulation in humans.


September 22, 2009

Anti-Newtonian dynamics

Clint Sprott, UW Department of Physics

This talk describes a world in which Newton’s first and second laws hold, but Newton’s third law takes the form that the forces between any two objects are equal in magnitude and direction. The dynamics for such a system exhibit curious and unfamiliar features including chaos for two bodies in two spatial dimensions. This talk is an introduction to a more detailed talk to be given on October 6th by Vladimir Zhdankin.

Ref: J. C. Sprott, Am. J. Phys. 77, 783-787 (2009)
This talk is available as a PowerPoint Presentation.


September 29, 2009

Some possible regulatory changes for U.S. financial markets

Don Hester, UW Department of Economics

This talk is awkward because regulatory change is contentious and legislation about changes is being hotly debated as I organize my comments. Consequently, I will briefly 1) explain why new regulations are needed, 2) propose some reforms that address these needs, and then 3) critically comment on likely legislation.


October 6, 2009

Simulation of swarming behavior using anti-Newtonian forces

Vladimir Zhdankin, UW Department of Physics

The emergent behavior of swarming is investigated by using computer simulation. Each swarm agent can be represented as a particle being influenced by forces due to the other agents in the system. A short-range repulsive force and long-range attractive force results in cohesive swarming behavior. However, more complicated dynamics can occur when two distinct species are defined to interact with different force laws. In order to recreate predator and prey swarming behavior that has been observed in nature, an "anti-Newtonian" force will be used between the two species, which violates Newton's Third Law. The resulting dynamics display a lush variety of features, including chaos and emergent behavior. The interesting cases will be demonstrated visually through animations that show the simulations unfold.

This talk is available as a PowerPoint Presentation.


October 13, 2009

Conjectures on music, artistry and the brain
 
Russell Gardner, UW Department of Psychiatry
 
George Steiner tells that  “… we write about books or about music or about art because ‘some primary instinct of communion’ would have us share with and communicate to others an overwhelming enrichment…” He felt this in 1959 with his first major writing and it remained his conviction. I find it resonates, yet how does it work? What does “instinct” mean in terms of the brain? I am not a musician and though always finding music a pleasure and most interesting challenge, I have felt the reasons mysterious ones. Why do people perform? Why do people listen? Where and how in the brain does art generally and music specifically gain its place in humans? What I will say hinges on various recent readings and on communications for the past two years with fellow members of the Arts Immersion (AIm) group. Plus, present some ideas on the medial temporal lobes that bear on performance issues and on evolutionary biology as these bear on human communication. I hope to address how do “artistic” people – including musicians – compare and contrast with other people? How does the musical communication share features of other communications and how may it stand unique? How does it compare/contrast with other means of artistic expression? How does sound production and appreciation in non-human animals bear on the subject?
 
1.     Gardner, Howard: In search of the Ur-song. In Gardner, Howard: Art Mind & Brain: A Cognitive Approach to Creativity. New York, NY: Basic Books, Inc., 1982.
2.     Levitan, Daniel J. This is Your Brain on Music: The Science of a Human Obsession. NY: Plume Penquin, 2006.
3.     Mithen, Steve: The Singing Neanderthals: The Origins of Music, Language, Mind and Body. Cambridge, MA: Harvard University Press, 2006.
4.     Sacks O: Musicophilia: Tales of Music and The Brain. NY: Knopf, 2007.
5.     Steiner, George: Introduction, A Reader. OUP, 1984, p.7.

This talk is available on video.


October 20, 2009

High-Energy neutrino astronomy: Towards a kilometer-scale neutrino observatory.
 
Francis Halzen, UW Department of Physics 
 
Kilometer-scale neutrino detectors such as IceCube are discovery instruments covering nuclear and particle physics, cosmology and astronomy. Examples of their multidisciplinary missions include the search for the particle nature of dark matter and for additional small dimensions of space. In the end, their conceptual design is very much anchored to the observational fact that Nature produces photons and protons with energies in excess of one hundred and one hundred million Terraelectronvolts, respectively. The cosmic ray connection sets the scale of cosmic neutrino fluxes. The problem has been to develop a robust and affordable technology to build the kilometer-scale neutrino detectors required to detect candidate sources such as supernova remnants and active galxies. The AMANDA telescope transforming ultra-clear deep Antarctic ice into a Cherenkov detector of muons and showers initiated by neutrinos of all three flavors, has met this challenge. Having collected more than 6000 well-reconstructed muon neutrinos of 50 GeV ~ 500 TeV energy, AMANDA represented a proof of concept for the ultimate kilometer-scale neutrino observatory, IceCube, now almost complete and producing results exceeding seven years of AMANDA data in sensitivity.


October 27, 2009

Chaos unfolding with control of greenhouse gases: Relevance of carbon taxes and cap-and-trade

Martin and Betsy David, UW Department of Economics
 
Effluent taxes and “cap-and-trade” have been discussed for 25-plus years. These “mechanisms” have been applied to a variety of emission and congestion problems. Applications have demonstrated that emissions of wastes that damage environment can be reduced.  Effluent taxes and “cap-and-trade” mechanisms only work when two conditions are met: (a) Effluents are continuously monitored to yield timely and publicly-available information; (b) Enforcement consists of instantaneous financial penalties that are large in comparison to the cost of controlling the effluent. (Think of parking and speeding tickets.  Effective enforcement requires both monitoring and penalties that hurt.)
 
(1) We will explain how and why carbon taxes are preferable to cap-and-trade and what weaknesses have emasculated the bill passed by the House of Representatives.
 
(2) Actuarial science makes it clear that timely control of CO2e gasses are an “insurance premium” that pays benefits in reduced mortality, in reduced “defensive investments” required to control damage from sea level rise, in reduced costs of human resettlement occasioned by reduced availability of water in some areas and in change in the location of productive agriculture, including possible reductions in the extent of arable land.
 
(3) The chaotic aspect of control of CO2e gases is a public goods problem. Everyone wishes to graze on the atmospheric commons. No one has a direct economic incentive to cease grazing.
 
Economists have not solved three problems: (1) How do we value (discount) benefits that accrue to other generations 50 years from now? (2) How do we overcome cognitive problems that voters and consumers face when making decisions related to events in a distant future?  (3) How do we get both consumers and producers to cope with the uncertainty of our knowledge?
 
Adam Smith’s “invisible hand” of market-trading will guide us to a tragic denouement. Can democratically-crafted law and a government bureaucracy improve upon that outcome?

This talk is available as a PowerPoint Presentation.


November 3, 2009 (5310 Chamberlin)

Poetry, mathematics, and science

Robin Chapman, UW Department of Communicative Disorders

I'll read poems of my own from Chaos seminar topics and from several recent anthologies that focus on the use of mathematics and science in poetry across the centuries, and then discuss briefly, and speculatively, what questions a science of poetry comprehension might ask.


November 10, 2009 (5310 Chamberlin)

The stability of oscillators

George Hrabovsky, Madison Area Science and Technology

By converting an oscillator equation to a well-known special function equation, it is possible to apply a graphical method of analysis to determine if an oscillation is stable, and to locate where solutions become unphysical when it is not stable.


November 17, 2009 (5310 Chamberlin)

Age Related Macular Degeneration Through the Eye of the Fly

Nansi Colley, UW Department of Ophthalmology & Visual Sciences

A highly magnified view of a fruit fly's eye shows the light-sensitive cellular structures known as rhabdomeres.  These specialized structures in the retina transform light into electrical impulses that the brain recognizes as “sight.”  Analogous structures serve the same function in humans.  The fly’s surprising genetic similarity to humans allows Nansi Colley, PhD, a UW Eye Research Institute scientist, to pinpoint mutations leading to macular degeneration, retinitis pigmentosa, and other vision-threatening diseases.


November 24, 2009 (5310 Chamberlin)

Directed evolution of ionizing radiation resistance in Escherichia coli

Michael Cox, UW Department of Biochemistry
 
We have generated extreme ionizing radiation resistance in a relatively sensitive bacterial species, Escherichia coli, by directed evolution. Four populations of Escherichia coli K12 were independently derived from strain MG1655, each specifically adapted to survive exposure to high doses of ionizing radiation. D37 values for strains isolated from two of the populations approached that exhibited by Deinococcus radiodurans. Complete genomic sequencing was carried out on nine purified strains derived from these populations. Clear mutational patterns were observed that both pointed to key underlying mechanisms and guided further characterization of the strains. In these evolved populations, passive genomic protection is not in evidence. Instead, enhanced recombinational DNA repair makes a prominent but probably not exclusive contribution to genome reconstitution. Multiple genes, multiple alleles of some genes, multiple mechanisms, and multiple evolutionary pathways all play a role in the evolutionary acquisition of extreme radiation resistance. Several mutations in the recA gene and a deletion of the e14 prophage both demonstrably contribute to and partially explain the new phenotype. Mutations in additional components of the bacterial recombinational repair system and the replication restart primosome are also prominent, as are mutations in genes involved in cell division, protein turnover and glutamate transport. At least some evolutionary pathways to extreme radiation resistance are constrained by the temporally ordered appearance of specific alleles.


December 1, 2009 (5310 Chamberlin)

Health Care Reform: what are we reforming?

Linda Reivitz, UW School of Nursing

Health care reform, and ideas for national health insurance, have been part of our national dialogue at least since 1912, when the idea was proposed by Theodore Roosevelt . We're still talking about health care reform today. But what is health care reform. And what are we 'reforming' anyway. Is 'reform" going to happen. What would change if it did. Of all the reform ideas now being discussed, which one is "best"? And how many people are really uninsured? The answers to these questions will be discussed by Linda Reivitz, an instructor of health policy in the UW School of Nursing and former legislation aide on Capitol Hill. Says Reivitz: as I write this in late September, two things are clear: first, the world of "health care reform" will surely be a lot different in December, 2009 than it is today; and second, questions about public policy are rarely answered using the scientific method. Talking about health care and health reform to a seminar on Chaos and Complex Systems is totally apropos.  

For those who have an interest in comparing, across a number of characteristics and plan components, the leading comprehensive reform proposals being considered by the Congress, you can find this information at http://www.kff.org/healthreform/upload/healthreform_sbs_full.pdf.

This talk is available as a PowerPoint Presentation.


December 8, 2009 (5310 Chamberlin)

Living the unknown: A dancer's perspective

Peggy Choy, UW Department of Dance

In these times of economic and social turmoil, we live with a sense of growing insecurity. Through the lens of dance, we can understand the past--both mythic and real--and investigate the present to fearlessly move into the future.


December 15, 2009 (5310 Chamberlin)

The cosmic history of supermassive black holes

Amy Barger, UW Department of Astronomy

The early universe was dominated by a small number of giant galaxies containing colossal black holes and prodigious bursts of star formation. More recently, the creation of stars and the accretion of material into black holes has been taking place in a large number of medium-size and small galaxies. I will present observations made at many different wavelengths that show this vast downsizing of cosmic activity.