Complex Systems: Mathematics, Computation & Science
(Leader: Prof. Greg McColm)
Wednesday, November 26, 2003
| Title |
TBA |
| Speaker |
TBA |
| Time |
1:00-2:00 p.m. |
| Place |
SCA 202 |
Wednesday, November 19, 2003
| Title |
Deoxyribozyme-based decision-making networks: Logic gates,
circuits and automata |
| Speaker |
Milan Stojanovic
Department of Chemistry
Columbia University
|
| Time |
1:00-2:00 p.m. |
| Place |
SCA 202 |
Abstract
Deoxyribozymes are nucleic acid enzymes. Using modular design, deoxyribozymes
may be turned into sensors for oligonucleo-tides. Extending this principle,
a complete set of logic gates can be constructed, with oligonucleotides with
inputs and catalytic chemical reaction as an output. These logic gates could
be arranged into solution-phase circuits and automata, capable of more complex
Boolean calculations.
Wednesday, November 12, 2003
| Title |
TBA |
| Speaker |
TBA |
| Time |
1:00-2:00 p.m. |
| Place |
SCA 202 |
Wednesday, October 29, 2003
| Title |
When will it happen? "Stopping Time" and "Concentration |
| Speaker |
Professor Greg McColm
|
| Time |
1:00-2:00 p.m. |
| Place |
SCA 202 |
Abstract
Many phenomena involve a scientist waiting to see WHEN something will happen.
The time WHEN it happens is called the "stopping time," as that is when
the scientist can stop waiting.
Some phenomena are actually complexes of many simpler phenomena, and what we
are waiting for is some global event that is a consequence of many local events.
The question is: how predictable is the time the global event occurs?
We will look at some of the examples, issues and outstanding problems in this
area.
NOTE: This presentation will be designed to be accessible to
non-mathematicians.
Wednesday, October 15, 2003
| Title |
Dispersal Ecology: Why it's Important Biologically,
and Why and Where Current Models Fail |
| Speaker |
Professor Gordon Fox
Department of Biology |
| Time |
1:00-2:00 p.m. |
| Place |
SCA 202 |
Abstract
TBA
Wednesday, October 1, 2003
| Title |
Bifurcation of Kidney Hemodynamics in Hypertension |
| Speaker |
Daniel Yip
Department of Physiology and Biophysics |
| Time |
1:00-2:00 p.m. |
| Place |
SCA 202 |
Abstract
Each rat kidney is composed of 250,000-500,000 functional subunits called
nephron. Each nephron is a limited cycle oscillator coupled to adjacent nephrons
that supplied by the same cortical radial artery. The oscillations are due to the
time delays and intrinsic nonlinearity in the intra-nephron feedback loop,
tubuloglomerular feedback. Oscillations of 30 mHz are found in hydraulic pressure,
flow and chloride concentrations within each nephron. The oscillations become
aperiodic in animal with genetic hypertension, or experimentally induced
hypertension. The time series of these apparent random fluctuations bear some
characteristic of deterministic chaos. Using non-invasive laser doppler
velocimetry to monitor the spontaneous variations of blood flow in a single
nephron. We detected a fast oscillation (100-150 mHz) superimposes on top of the
tubuloglomerular feedback mediated oscillations (30 mHz). We suggested that these
two oscillatory mechanisms interact in a nonlinear manner, and that development of
hypertension alters this interaction and leads to the bifurcation of kidney
hemodynamics.
Wednesday, September 17, 2003
| Title |
Mathematical Models for Recombinant DNA Processes |
| Speaker |
Natasha Jonoska and Masahico Saito |
| Time |
1:00-2:00 p.m. |
| Place |
SCA 202 |
Abstract
We will present a mathematical observation about how
knot theory could give a possible explanation for actions of
topoisomerases. We also present another mathematical observation
about possible use of formal language theory in explaining the
gene assembly in ciliates. We hope to start a discussion about
these and other genetic processes that could be explained by some
of these techniques.