Madison Chaos and Complex Systems Seminar

Spring 2015 Seminars

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

Short List

Join us for lunch during the summer on the Memorial Union Terrace at noon each Tuesday, starting May 12th!


January 20, 2015

The passenger pigeon: Why it went extinct, and can we resurrect it?

Stan Temple, Nelson Institute

The passenger pigeon declined from billions to none in the span of 50 years. Stan Temple analyses how this incredible collapse could have happened. And now, 100 years after the species' extinction, advances in biotechnology have led to visions of resurrecting the species. Could we? Should we?

January 27, 2015

Madison Science Museum: from chaos to complexity

Olga Trubetskoy and Dave Nelson, Madison Science Museum

We will start from ongoing story of starting up a science museum in Madison describing how from initial turmoil, obstacles and defeats the museum is now emerging being shaped by inspiration, visions and public involvement. We will resume the saga by revealing a few curious stories from  Madison science history scene that will be a part of a future museum exhibits.

February 3, 2015

Re-conceptualizing visuospatial memory development as an increase in dynamic stability

Vanessa Simmering, UW Department of Psychology

For over a century, developmental psychologists have documented how visuospatial memory improves from infancy through early childhood. A variety of theories have been proposed to account for these improvements, with most addressing only a small developmental period and/or single behavioral task, making these theories difficult to generalize. For example, Piaget attributed changes between 8 and 12 months in infants' errors in a search task to the acquisition of object permanence, but infants between 4 and 16 months show other improvements in the durability and capacity of memory, in both search and looking tasks, that cannot be explained by this theory. The goal of my research program is to advance a comprehensive theory of visuospatial memory development to explain multiple improvements across tasks and age groups. My colleagues and I have proposed a dynamic systems account of memory development which emphasizes the processes that underlie the formation, maintenance, and use of memory representations across behavioral contexts. By formalizing this theory in a dynamic neural field model, my research shows that a host of developmental improvements in memory can emerge through a common change in the dynamic stability of the memory system. I will present empirical evidence that memory capacity is not fixed but varies with task contexts. Furthermore, my model simulations predicted that different task structures will yield inconsistent capacity estimates within the same group of participants while still showing correlations in performance across these tasks. These results suggest that a full explanation of visuospatial memory development will require understanding how memory functions in the moment of the task at hand.

February 10, 2015

Energy and ecosystems: Howard Odum's seminal 1973 paper, "Energy, ecology, and economics," 42 years later

Bill Fischer, Agronomy, Business, Law, and Psychiatry

ECOLOGICAL ENERGETICS AS BIOPHYSICAL ECONOMICS: All economic value, development, and growth depend on energy flow.  In Energy, Ecology, and Economics (1974), Howard T. Odum extended his analysis of energetics in natural ecosystems to the human economy. His basic proposals continue to be developed and applied to economics, but mainstream economics continues to neglect energetics. ENERGY COST AND VALUE: Economic production has correlated with energy use throughout history.  Energy is the predominant factor in economic production and GDP. GROWTH: Population and production grew only slowly until the 19th century.  Growth accelerated with coal in the nineteenth century and even more with oil in the twentieth. THE CURRENT QUANDARY: Growth has slowed in the past 40 years.  Per capita economic growth may have stopped or be negative. ENERGY ACCOUNTING:  Energy cost, insignificant compared to capital and labor costs for almost all human history, is now substantial.  Current price cannot account true energy costs and value. NET ENERGY OR EROI: net energy, or Energy Returned on Energy Invested (EROI) is key to energetics accounting.  EROI declines prevent growth.  We have little idea of today’s economy’s net energy or of alternatives. DEBT historically presumes growth.  We don’t know how to manage debt without growth. And the just-in-time economy increases our vulnerability to shocks in the debt system.

This talk is available as a PowerPoint Presentation.

February 17, 2015

The limits to growth or the limits to models?

Jim Blair, Milton and Edgewood College


Thomas Malthus and the Malthusian Trap

The Limits to Growth in 3 iterations (Club of Rome)

The Limits to the Limits to Growth  (Ben Bova)

The Bet:  Paul Ehrlich vs Julian Simon

2020 Vision (1970), and at the Midway (1995)

This talk is available as a PowerPoint Presentation.

February 24, 2015

Sweet talks and trade deals in symbiotic associations

Jean-Michel Ané, UW Department of Agronomy

Living organisms, such as plants, animals and humans in particular, interact constantly with microbes present in their environment to form symbioses. These symbioses are very dynamic and can range all along a continuum between mutually beneficial interactions to parasitic ones. Sometimes, these associations are necessary for the survival of one or both partners, but they can also be facultative. These associations can be lost or acquired over time depending on environmental constraints. We will discuss how plants and microbes communicate (sweet talks) to initiate and maintain symbiotic associations, how these mechanisms evolved or have been lost sometimes, but also how nutrients exchanges between partners are regulated with interesting similarities to economic markets (trade deals).

This talk is available as a Prezi presentation.

March 3, 2015

Linking dynamics of chemistry, physiology and genetics in ecosystems through spectroscopy

Phil Townsend, UW Department of Forest &Wildlife Ecology

Contact and imaging spectroscopy show great promise for measurement of the physiology of ecosystems related both to environmental drivers and genetics. Over the last decade, researchers have demonstrated the use of reflectance spectroscopy to rapidly and accurately characterize features of ecosystems that previously entailed considerable monetary expense and effort, and/or were not thought to be mappable. We have discovered that plant spectra provide a record of plant traits and can be exploited to better understand their function in time and space. Though we do not understand all drivers of variation -- at leaf, canopy and ecosystem levels -- here I will provide evidence that we can infer properties ranging from gene expression to photosynthetic capacity to nutrient availability. For example, we have used spectroscopy to characterize forest response to insect herbivores and to track foliar chemistry as it is related to forest productivity and nutrient availability following logging. In agricultural settings, spectroscopy offers the capacity to measure the physiological effects of pests such as aphids and disease on plant physiology and ultimately yield. In aspen forests, we show how traits and genetics co-vary based on inferences from imaging spectroscopy. The potential future applications of these methods are extensive, and adaptation of spectrometers to deploy in a range of settings will enable us to bridge the gaps in spatial and temporal measurement capacity from the leaf/canopy to airborne to spaceborne levels.

March 10, 2015

Characterizing variations in Wisconsin’s extreme weather

Steve Vavrus, Nelson Institute

Anecdotal evidence suggests an increasing occurrence of extreme weather in recent years, but a major impediment to identifying and quantifying trends is the absence of a common measuring stick.  Many definitions of extreme weather exist, but they are often haphazard and not comparable to one other for quantifying the aggregate behavior of extremes.  To help remedy this problem, I created a simple, non-parametric index of extreme weather based on the combined percentile rankings of temperature and precipitation (at monthly or longer timescales).  This integrated index reveals that extreme weather has indeed been unusually pronounced in recent years in Madison and across Wisconsin.  However, the reasons for the high index values vary considerably by location.  The temporal and spatial variations of extreme weather in Wisconsin and elsewhere are probably a combination of chaotic weather processes and emerging anthropogenic climate change.

March 17, 2015

Chaos for the home electronics lab

Wesley Thio, Ohio State University

Electronic devices that behave chaotically are often considered to be a nuisance, whether it’s a buzzing air conditioner, a flickering lightbulb or a phone that just keeps disconnecting from the internet.  However by using some basic electronics tools, I intend to demonstrate the opposite, that circuits behaving according to the principles of chaos theory can be beautiful and have potentially useful functions. I will also show how accessible these circuits are to the home tinkerer in their basement and give many visual examples that will even appeal to non-engineers. A preview of one experiment is given below.
Wesley Thio

This talk is available as a PowerPoint Presentation.

March 24, 2015

What is the Internet of Things (IOT) and key trends?

Sandra Bradley, UW Department of Industrial Engineering

The landscape of technology is changing at an ever-increasingly rapid pace. Broadband connectivity is inexpensive and ubiquitous; devices are becoming more powerful and smaller with a variety of on-board sensors. The data in this machine-to-machine world creates "smart" experiences for everyday consumers and businesses alike. This highly-charged connected world is what we are calling the Internet of Things. As Boo-Keun Yoon, president and CEO of Samsung Electronics Samsung said at a conference recently, "IoT isn't science fiction anymore. It's science fact." We are already seeing applications ranging from energy efficiency to logistics to personal healthcare to smart homes using IoT concepts. In this session we will give an overview of what IoT is, how it will change the way we live and work, and will talk about key trends and challenges in IoT.

This talk is available as a PowerPoint Presentation.

April 7, 2015

Movement of eosinophils into lungs of patients with asthma

Deane Mosher, UW Department of Biomolecular Chemistry

Eosinophils are granular leukocytes (white cells) that are relatively scarce in blood but more common in tissues. Tissue eosinophils contribute to tissue homeostasis in the gut and other organs and are a prominent component of inflammation associated with malignancies, viral and helminthic infections, allergic diseases such as asthma, and orderly tissue repair. Among leukocytes, eosinophils are exceptional in a number of ways—content of eosinophilic granules; complement of receptors and other molecules that control activation and trafficking; complement of mediator-generating enzymes; and polarization upon activation into a granular compartment and a nucleopod, a specialized protrusion occupied by the nucleus. I will describe a series of related processes that target blood eosinophils to the bronchial tree of asthmatic patients.

April 14, 2015

How scale-dependent are ecosystem-atmosphere exchanges?

Ankur Desai, UW Department of Atmospheric and Oceanic Sciences

Terrestrial surfaces are a lower boundary condition for exchanges of trace gases, energy, and momentum with the atmosphere and consist of biologically-active organisms. In terrestrial ecosystems, information relevant to these processes scales upwards from gene to cell to microbe to plant, while for the atmosphere, the relevant modes of interactions with these processes scale downward from climate dynamics to synoptic systems to boundary layer turbulence. Consequently, identifying the appropriate space and time scale over which ecosystems interact with the atmosphere is critical for improving theoretical and numerical simulations of these processes. Further, there is a fundamental spatiotemporal scale mismatch between the terrestrial observations made about these process and the spatial scale over which numerical models of ecosystems, weather systems, and climate operate. I will present a general overview of this problem, a few examples of work in my lab addressing this issue from the perspective of 1) modeling spatial heterogeneity in ecosystem energy balance, 2) data synthesis for terrestrial carbon cycling, and 3) rectification of eddy covariance flux tower observation flux footprint bias. The overview and examples will be used to engage discussion in a general conceptual framework on ecosystem-atmosphere scaling and model-data comparison.

April 21, 2015

Towards understanding IceCube high energy neutrinos

Yang Bai, UW Department of Physics

The IceCube collaboration has recently observed high energy neutrinos in the 30 TeV to 2 PeV range. The flux is much above the atmospheric neutrino background and requires new sources to explain its origin. In this talk, I will provide a list of potential explanations with a focus on decaying dark matter and point-like sources.

April 28, 2015

Barker frailty, Barker echoes and warped older age mortality dynamics

Hiram Beltran Sanchez, UW Center for Demography and Health of Aging

An association between early childhood and old age mortality in successive  birth cohorts (Barker frailty) generates conditions under which old age mortality can increase, decrease or remain constant even though background mortality is declining (Barker echoes). The stronger the association is, the larger will  be the deviations from background mortality, but,  paradoxically,  the less durable this deviant behavior will be (warped dynamics). Under regimes of strong Barker frailty, life expectancy at older ages my decrease even though survival conditions are improving.

May 5, 2015

Year-end celebration

Following the tradition begun last year in which we had a delightful discussion of where we have come and where we might go with the seminars, this last seminar of the semester will be devoted to a continuation of that discussion without any formal speaker. We will also discuss what we want to do during our informal weekly lunches on the Memorial Union Terrace which begin on May 12th. This celebration will include expanded refreshments, to which your own culinary contribution is welcome.