Madison Chaos and Complex Systems Seminar

Fall 2006 Seminars

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

Short List


September 5, 2006

Vegetational responses to novel climate regimes
Jack Williams, UW Dept of Geography
Three lines of evidence – niche theory, late-Quaternary fossil data, and GCM simulations of late-Quaternary and end-21st-century climates – together suggest that novel plant communities are likely to arise in response to novel 21st-century climate change.  Niche theory predicts that, if species have unique climatic tolerances and optima, then novel species associations should arise in response to climate regimes outside the modern climatic envelope.  This hypothesis is supported by late-Quaternary pollen data, which show 1) large and individualistic shifts in plant distributions in response to climate change, and 2) the widespread occurrence of ‘no-analog’ fossil pollen assemblages in late-glacial and early-Holocene sediments.  These no-analog pollen assemblages are commonly interpreted to indicate the past existence of plant communities compositionally unlike any modern plant communities.  In North America, the spatial and temporal distribution of the no-analog pollen assemblages apparently correspond to insolation and climatic regimes also with no counterpart in extant North American climates.  Analyses of 20th- and 21st-century climate simulations produced for the fourth assessment report of the Intergovernmental Panel on Climate Change (IPCC AR4) indicate that some end-21st-century climate will lack good analogs in end-20th-century climates, particularly in humid tropical regions.  These areas therefore may be at higher risk of developing novel plant associations and other ecological surprises.  Additionally, some end-20th-century climates are projected to disappear during the 21st-century, increasing the risk of extinction for species endemic to those climates.  Areas with disappearing 20th-century climates are concentrated in tropical montane regions and the poleward portions of continents. 

September 12, 2006

Cloud cover, jet contrails, and climate change

David Travis, University of Wisconsin - Whitewater

Efforts to predict global scale climate change are complicated by the many regional-scale changes occurring simultaneously, and in response to, those operating at larger scales.  These can impact the large-scale climate system in the same direction or act to offset the current direction of change.  The role of clouds in current and future climate change provides one example of where substantial uncertainty exists in climate models.  This is in part due to the differing impacts of high (warming) versus low (cooling) clouds on the temperature of the surface and lower atmosphere. Further complicating this issue, in certain regions of the world, is the role of jet condensation trails (contrails) resulting from our growing dependency on aviation. Contrails represent a uniquely thick cloud type for being located at such a high altitude (typically between 10-12 km) and, thus, have the ability to both substantially cool and warm the atmosphere and surface below.  The net effect, or “contrail forcing”, depends on their age, time of day, and season of occurrence. 

This presentation focuses on the rapid increase in jet contrail coverage occurring in the U.S. and investigates causes for such an increase beyond just growth in commercial aviation.  In addition, discussion is provided on recent advances in better understanding contrail impacts on climate, including the unusual opportunity provided during the three-day grounding of all U.S. commercial aviation, following the Sept. 11th, 2001 terrorist attacks.

September 19, 2006

Behavioral responses to stochastic demographic events in wild Muriqui monkeys

Karen Strier, UW Department of Anthropology

September 26, 2006

The power of expectancy, anxiety, and the brain

Jack Nitschke, UW Departments of Psychiatry and Psychology

Our expectations have an impact on our lives in multiple ways, including our perception of external events and our emotional responses to them. The impact can be positive in terms of enhancing the pleasant emotions following success or in terms of mitigating the negative emotional consequences of adversity. The impact of expectancy can also be negative, as seen in individuals suffering from anxiety disorders. For them, expectations about possible negative events in the future can result in debilitating levels of worry and distress. Research in my laboratory investigates the brain mechanisms responsible for these expectancy effects. Using both clinical and healthy populations, our research has shown how expectancy modulates neural responses to emotional events and influences perception and subsequent memory of those events.

October 3, 2006

What we've learned about inflation from the 2.7 K cosmic microwave background radiation

Peter Timbie, UW Department of Physics

October 10, 2006

Climate predictions: Sine waves and fractals

C. S. Clay, UW Department of Geology and Geophysics

Spectrum analysis of climate data or time series, g(t) were made using a digital-finite form of the infinite  Fourier integrals.  The spectra G(f) are complex because the signals are real.  The code can handle non-uniformly spaced data points.

The data are the analysis of Antarctic ice cores from Dome C.  From the data, peaks or warm conditions have a roughly 100 ky  separation. Spectral analysis gives spectral peaks at 100 ky, 41 ky, and several in the 23 to 19 ky range and are the insolation periods.  These spectral peaks were used to choose several G(f).  Using these G(f), the Fourier transformation gave a climate simulation in which the insolation is going down.

Fractal analysis is usually done on uniformly sampled time series. Inverse integral Fourier transformation of G(f) is used to create a uniformly spaced  g'(t).   Fractal analysis of a time series has shown that the climate time series may be fractal for periods less than 20 ky.

Conversations about climates with Alley, Kutzbach, Maher, and Young are acknowledged.  W. F. Ruddiman, "How did humans first alter global climate," Sci. Am. March, 46-53 (2005) finds that the insolation has reduced to perhaps glacial levels but the humans are keeping the climate warm and even making it hotter.

October 17, 2006

Ganging up on software bugs

Ben Liblit, UW Department of Computer Sciences

The resources available for testing and verifying software are always limited, and through sheer numbers an application's user community will uncover many flaws not caught during development. The Cooperative Bug Isolation Project (CBI) marshals large user communities into a massive distributed debugging army to help programmers find and fix problems that appear after deployment. Dynamic instrumentation based on sparse random sampling provides our raw data; statistical machine learning techniques mine this data for critical bug predictors; static program analysis places bug predictors back in context of the program under study. We discuss CBI's dynamic, statistical, and static views of post-deployment debugging and show how these three different approaches join together to help improve software quality in an imperfect world.

October 24, 2006

Mirroring minds: Are mirror neuron systems the DNA of psychology or a red herring?

Deric Bownds, UW Department of Zoology

This talk will present some of the data on mirror neuron systems in monkeys and humans and then proceed to a collaborative discussion of its relevance to understanding intentions, theory of mind, autism, language......

This talk is available on the speaker's web site.

October 31, 2006

Characterizing global transport of air pollution

Tracey Holloway, Gaylord Nelson Institute

Air pollution can travel far beyond national borders, impacting  public health, agriculture, visibility, and climate in downwind  regions. Sometimes, pollutants are transported in intense, discrete  episodes, such as dust storms from Asia that cross the Pacific and  lead to unhealthy air in the Western U.S. Emissions of smoke and  chemicals also contribute to a belt of air pollution encircling the  Northern Hemisphere, clearly visible in satellite images. Using a  global model of atmospheric chemistry and transport, we characterize  when and where episodic pollution transport is most important. These  results will be presented, and connected with broader issues in  intercontinental pollution transport science and policy.

November 7, 2006

Of genes and drugs
Olga Trubetskoy, PanVera, UW Research Park

There are well documented differences in a frequency of genetic mutations (genetic polymorphism) in certain human groups that have a long history of shared environmental conditions. The polymorphisms in a group of enzymes involved into metabolism of drugs may lead to toxic effects and adverse drug reactions in humans who are carriers of these polymorphic variants. Individuals with specific polymorphic variants may experience toxic accumulation of certain drugs resulting in increased toxicity and elevated risks of adverse drug reactions or, surprisingly, experience much higher cure rates for certain diseases. Existence of these polymorphisms in human genomes reveals a long history of adaptation of certain groups to specific environmental factors, often needed to reduce their toxic effects and beneficial for survival. For example, mutations in CYP2C19 are prevalent in Southeastern Asian populations because they are beneficial for their carriers providing the resistance to high doses of region-specific spices found in the local diet. But such mutations are considered beneficial only in response to specific environmental factors. What happens if the environment changes? To what degree your drug response, therapeutic effects and toxicity are dependent on your genetic make-up? Are your interactions with environment “recorded” in your personal genetic history? Can you change this “record” or create your own microenvironment  for better individual adaptation?

November 14, 2006

Climate change studies in the upper atmosphere

Susan Nossal, UW Department of Physics
Increases in greenhouse gases such as carbon dioxide and methane are expected to alter the middle and upper regions of the atmosphere, as well as the troposphere. Scientists are studying vertical as well as geographical patterns of climate change to form a better understanding of the climate system. In the middle and upper atmosphere, temperatures are expected to cool and the atmospheric density and composition is predicted to change. Understanding sources of natural variability in the upper atmosphere such as the solar cycle is needed to isolate signatures of natural variability from those due to human-caused change. This talk will provide an overview of some of the efforts to investigate climate change processes in the middle and upper atmosphere, with a focus on upper atmospheric studies of hydrogen, a by-product of methane emissions below.

November 21, 2006

Regional patterns of climate variability & influence of chaos

John Young, UW Department of Atmospheric and Oceanic Sciences

The two strongest signals in climate observations over the past 30 years are rends ("climate warming") and ENSO (El Nino-Southern Oscillation).The patterns of these components are not uniform, but show geographical differences which arise from regional complexity and the physics of the large-scale winds. For example, the response called "global warming" is patchy, a result of predictable physics and chaos.

I will present figures of analyzed changes in temperature and precipitation for the globe and the U.S., and invite group questions and discussion.

November 28, 2006

From hybrid poplar to electric power - Recycling carbon dioxide using whole tree energy

Ken Ragland, UW Department of Mechanical Engineering

The Whole Tree Energy (WTE)  process is a method of generating renewable electric power in a sustainable, carbon dioxide neutral, and economical manner.  The entire process - planting tree slips, growing and harvesting trees, transporting and drying whole trees, and modifying conventional power plants - will be described.  Energy Performance systems Inc.  of Rogers, MN is the developer of the WTE process.  Research done at the UW Arlington Farms, Mechanical Engineering and the Forest Products Laboratory has contributed to this effort.  This approach is possible wherever  25 inches of rain per year and good soil are available.

December 5, 2006

Teaching concepts of complexity science to undergraduates

Cristie Hurd, UW Department of Zoology
The dominant understanding of the origination and perpetuation of organized structures is that an outside being with a goal, a plan, and the power of execution imposes order on a collection of parts.  As the subordinate parts in the hierarchical organizations of their families, schools, and churches, our students are intimately familiar with this top-down method of causality.  But our research in the physical, biological, and social sciences demonstrates that, at all scales, order emerges from the repeated interactions of parts.  Series of interactions can become cyclical.  Through feedback processes and the coupling of multiple cycles, higher-ordered structures emerge whose coherent pattern of organization perpetuates and, and in complex systems, adapts to changing conditions. We offer our students a bottom-up view of causality, but how well are they understanding it?  In this talk I’ll demonstrate how instructors can use multi-agent simulation models to let students discover the fundamental complexity concepts of emergence, non-linearity, and connectivity.

December 12, 2006

Origin and evolution of astrophysical magnetic fields

Ellen Zweibel, UW Department of Astronomy

Astrophysical bodies almost all appear to be magnetized, but it is widely accepted that magnetic fields were not created in the Big Bang. The current view is that very weak "seed" magnetic fields were generated by one of a number of plasma processes, and that these weak fields were then amplified by rotation and turbulence. I will discuss some recent models, with a focus on the basic issues.