Apr 20, 2010 - Don Moynihan, La Follette School of Public
Affairs
Apr 27, 2010 - Ananth Seshadri, Economics
May 4, 2010 - Deric Bownds, Zoology
Join us for lunch during the summer on the Union Terrace at noon
each Tuesday, starting May 11th!
Abstracts
January 19, 2010
An amazing freak wave
Chin H. Wu, UW Department of Civil and Environmental Engineering
Freak waves, alternatively called rogue waves or giant waves, are
exceptionally large, steep, and asymmetric waves whose heights
usually exceed by 2.2 times the significant wave height. They have
also been described as “holes in the sea”, “walls of waters”, or
three sisters! These waves have been long known to be notorious
hazards to navigation vessels and marine structures. Many sinister
marine episodes and their devastating impacts have prompted a great
interest in freak waves. With little warning, freak waves often
mysteriously occur as transient giant waves from wave groups in
random coastal and open seas. While statistical methods are widely
employed in examining the occurrence of such extreme sea conditions,
it is still unclear whether freak waves are rare realization of a
typical population or typical realization of a rare population.
Likewise, it is unclear the physical mechanisms of freak wave
formation and its characteristics. In this talk, we will report the
recent laboratory measurements on limiting freak waves on currents.
It is found that wave group structure is critical to determine the
formation and the geometric properties of freak waves. Strong
opposing currents inducing partial wave-blocking can significantly
promote the freak waves, which occur often in the Great Lakes and
Oceans.
January 26, 2010
Auditory activation with electric hearing: Studies on auditory
plasticity in deaf humans
Ruth Litovsky, UW Department of Communicative Disorders
It is not uncommon for individuals who are deaf to undergo surgical
treatment whereby they are fitted with cochlear implants (CIs).
These devices send electrical stimulation to the auditory nerve in
such a way that the brain can learn to interpret the stimulation,
and CI users can effectively understand speech and enjoy the
auditory world. Until recently, the standard of care had been to
implant candidate patients with a single device in one ear. More
recently, this standard has shifted such that two devices, bilateral
CIs, are being provided to growing number of patients. Being able to
hear with two ears affords humans functional abilities such as
localization of sounds and segregation of sources from background
noise. These abilities depend on binaural brain function, that is,
on neural circuits that integrate inputs from the two ears with
great precision. Our lab studies the emergence of binaural hearing
abilities in children and adults who had experienced various periods
of auditory deprivation prior to being activated with electric
hearing. Our studies address questions regarding the ability of the
auditory system to retain sensitivity to binaural hearing after
deprivation. In addition, in children who have never heard with
acoustic hearing, but whose brains are wired for acoustics, we study
the ability of the brain to respond to electric stimulation such
that the children attain age-appropriate abilities in domains of
language, speech and hearing.
February 2, 2010
Complex families: Some implications of multiple partner
fertility for research and policy
Maria Cancian, UW La Follette School of
Public Affairs
We most often think of families with children as including a mother,
father, and their children in common. However, 40 percent of
children are now born to unmarried parents, and recent research
suggests that more often than not, one or both of these parents will
go on to have children with other partners. The complex families
that result-- with siblings, half siblings and step siblings sharing
parents and sometimes living quarters-- raise a host of challenges
for research and policy. In this seminar I will draw on a series of
papers, coauthored with Dan Meyer and other collaborators, to
discuss the evolution of complex families and key related policy
issues.
The quest for algebraically simple chaotic systems began fifty years
ago when Ed Lorenz discovered chaos in a simple model of atmospheric
convection. By now, dozens of chaotic systems, some even simpler
than the celebrated Lorenz attractor, have been identifed and
studied. This talk will describe a 20-year effort to find even
simpler chaotic systems as summarized in a soon-to-be-published book
by the same title in which 280 examples, most of which have never
been previously published, are cataloged. Some new chaotic
electrical circuits will also be described and demonstrated.
Why doesn't my electricity come from the sun? Future photovoltaic
materials for harnessing solar energy
Mike Arnold, UW Department of Materials Science and Engineering
The Earth is continuously bathing in over 1017
watts of sunlight. This talk will discuss the science, technology,
and economics of using photovoltaic solar cells to collect and
convert a fraction of this free solar energy into electricity. In
particular, this talk will focus on the materials and composition of
photovoltaic solar cells and the principles of their operation and
will attempt to answer the question of why past and current solar
cell technologies have failed to become widespread. The talk will
conclude by discussing the future of solar photovoltaics and new
materials and technologies (with a focus on those being pursued by
my research group such as semiconducting carbon nanotubes) that have
the potential to boost the efficiency, decrease cost, and increase
the practicality of solar cells.
February 23, 2010
Pictures from piles of data
Michael Gleicher, UW Department of Computer Sciences
Most of my work is focused around a single (broad) question: How can
we use our understanding of human perception and artistic traditions
to improve our tools for communicating and data understanding? In
problems ranging from molecular biology to video editing, we are
faced with a deluge of data. In this talk, I'll survey some of the
ways we've tried to turn this problem into solutions. I'll discuss
our efforts in scientific visualization and multimedia, showing how
we can use ideas from art and perception to create novel tools for a
range of problems. Time permitting, I might also discuss some of my
efforts to create a cross-disciplinary course on Visualization.
March 2, 2010
Overview of satellite-based aviation applications for detection of
thunderstorms, turbulence, and volcanic ash
Wayne Feltz, UW Space Science and Engineering Center
The University of Wisconsin-Madison Cooperative Institute for
Meteorological Satellite Studies (CIMSS) Satellite Nowcasting and
Aviation APplication (SNAAP) team is heavily involved in research to
develop satellite-based nowcasting tools (0-3 hour forecast) for
improving aviation weather forecasting. Current areas of research
focus on satellite detection of aviation hazards such as convection,
turbulence, and volcanic ash using current and future weather
satellite systems. This seminar will overview this research as
well as in context toward improvement of future air transportation
route planning and warning for the general public.
March 9, 2010
Why we need to conserve crop diversity and what we need to know - An
example from the Andes
Eve Emshwiller, UW Department of Botany
Dr Emshwiller will provide an overview of the value of crop genetic
diversity and the kinds of information needed to conserve the
diversity of crop plants and their wild relatives. An ongoing
project in the Andes Mountains provides an example of research
designed to provide information for conservation. The tuber crop
“oca,” Oxalis tuberosa, is second to potatoes in the diet and
farming systems of traditional agriculturists in rural highland
communities of Peru and Bolivia. The crop is a polyploid, with eight
sets of chromosomes. Dr. Emshwiller’s research has focused on
finding out which wild Oxalis species may have hybridized to
contribute oca’s several genomes, and studying how the exchange of
planting material among farming families has affected the
distributions of varieties of the crop.
Exploring the conformational search leading to protein folding in
vitro and in the cell
Silvia Cavagnero, UW Department of Chemistry
Proteins are key components of all living cells and their correct in
vivo function is intimately connected to the well-being of every
living organism. The large conformational freedom of a protein chain
and its structural complexity suggests that understanding folding
mechanisms and predicting protein structure from amino acid sequence
may be dauntingly difficult. What have we learned from the studies
carried out on protein folding mechanisms over the last three
decades; are there any leading trends; and how do these trends
change (or are predicted to change) for proteins folding in the
cellular environment, where a lot of the relevant parameters are
dramatically tuned by various cellular components? This talk will
attempt to address some key aspects of the above topics and
highlight research directions in crucial need of further
exploration.
March 23, 2010
Emotional communication in primates: Music to their ears?
Chuck Snowdon, UW Department of Psychology
Vocal communication in nonhuman animals is thought to communicate
the emotional state of the caller and provide information about the
caller's behavior. An alternative view is that animal signals induce
emotional states in listeners. In support of this alternative are
the prosodic features of speech that humans use to communicate with
infants ("parentese") or their animals ("doggeral"). Building on
this idea, my collaborator, David Teie, a musician and composer and
I have hypothesized that music evolved from emotional communication
and is a powerful means to communicate emotions. We have
hypothesized several acoustic features that are emotional universals
and have tested these using music-naive cotton-top tamarins. Since
tamarins communicate with higher pitch and faster tempo than humans,
we also hypothesized that they would be indifferent to human based
music, but would instead respond emotionally to music composed at
their frequency range and tempo. Tamarins did show appropriate
emotional responses to music composed for them by David Teie and
were generally unresponsive to human music. The results have several
implications: emotional aspects of music may have a long
evolutionary history, animal vocalizations may serve to induce
emotional contagion in listeners and, although musical aspects of
emotions follow universal principles they actual music tested must
be appropriate to the vocal range and tempo of the species tested.
Running form modification: When self-selected is not preferred.
Bryan Heiderscheit, UW Orthopedics and Rehabilitation
While it is generally well accepted that an individual's patten of
running is optimized to conserve metabolic energy, at times, this
self-selection process may increase injury risk. That is, the
selected pattern may be one that increases local joint loading and
the potential for repetitive microtraumatic injury. This is
most evident in those just beginning to run as part of a regular
exercise program. Using research and patient care findings, I will
discuss how a simple modification to one's running gait can be an
effective component to the treatment and prevention of common
running-related injuries.
April 13, 2010
Shock waves in nature and in numerical computations
James Rossmanith, UW Department of Mathematics
Shock waves are propagating disturbances that are characterized by
an abrupt, nearly discontinuous change in the characteristics of a
fluid or plasma. They can occur in a variety of phenomena in both
laboratory and natural settings. Mathematically, shock waves are
difficult to handle since in general they are not unique solutions
of the equations that model them. Computationally, shock waves are
difficult to handle for several reasons: (1) most discontinuous
cannot be exactly represented on a discrete mesh, (2) standard
high-order methods are unstable for shocks, and (3) the numerical
schemes must be carefully constructed to yield the physically
correct solution.
In this talk I will begin by briefly reviewing the basic theory of
shock waves. I will then, mostly through computational examples,
describe the various pitfalls in trying to numerically solve
equations with shock solutions. Finally, I will describe some
strategies based on adaptive mesh refinement to obtain highly
accurate numerical solutions.
April 20, 2010
The dynamics of performance management: Governance reform amidst
complexity
Donald Moynihan, La Follette School of Public Affairs
Professor Moynihan examines efforts to make the public sector more
focused on outcomes through performance measurement
techniques. Bureaucrats use the data for different purposes,
and with different consequences, some unintended. This talk will
summarize these reforms, their consequences, and the particular
factors that affect how public actors use performance data.
April 27, 2010
Health and wealth over the life-cycle
Ananth Seshadri, UW Department of Economics
This talk presents a model of health investments over the life
cycle. Health affects both longevity and provides flow utility. We
analyze the interplay between consumption choices and investments in
health by solving each household's dynamic optimization problem to
obtain predictions on health investments and consumption choices
over the lifecycle. Our model does a good job of matching the
distribution of medical expenses across the households in the
sample. We use the model to examine the effects of several policies
on patterns of wealth and mortality.
May 4, 2010
Who wants to know? - The nature of our subjective "I"
Deric Bownds, UW Department of Zoology
Most cognitive neuroscientists are practicing Cartesian dualists in
their daily lives, even while knowing that there is no distinction
between our minds and bodies. They accept compelling modern
experiments (as well as ancient religious insights) demonstrating
that the 'self' or 'I' is a fiction, albeit a useful one we could
not live without. It is a ancient fiction that co-evolved with a
supportive neuroendocrine emotional repertoire to eventually
generate social brains capable of scientific and artistic culture.
The purpose of this talk is to outline a few central observations on
the nature of this phenomenal self, how it is constructed with
respect to the physical world and the social world of other humans.