Seminars are listed in reverse chronological order. The
top of the list is subject to change, since more seminars
are still being planned. All seminars are held at
3:10p.m.
in 1310 Stevenson Center
unless otherwise noted. For further
information on events in the department, you may also
consult the
colloquia schedule, the
weekly
calendar and past
calendars.
Wednesday, November 29, 3:10 PM, SC 1310.
Hannah Callender, Vanderbilt University
Title: Modeling Small Molecule Dynamics in Macrophages Downstream Purinergic Receptor Stimulation.
Abstract: A mathematical description is given for the uridine 5'-diphosphate signaling pathway in the RAW 264.7 macrophage, a type of white blood cell that surrounds and kills microorganisms, removes dead cells, and stimulates the action of other immune system cells. A comprehensive single-cell mathematical model is developed which includes a system of nonlinear ordinary differential equations describing the major pathway components, with an emphasis on the production and degradation of diacylglycerol, a cellular second messenger molecule which plays an important role in initiating various changes in cell behavior, including cell activation, differentiation, proliferation and tumor promotion. Modeling techniques, challenges, and computational simulations will be presented.
Wednesday, November 8, 3:10 PM, SC 1310.
Anne Kenworthy, Vanderbilt University
Title: Modeling intracellular transport and membrane domain structure
in living cells.
Abstract: We are interested in the fundamental processes that cells use to target
membrane proteins to their correct intracellular destination, as well as how
the lateral organization of proteins within cell membranes impacts their
function. I will discuss two ongoing projects in the lab that use a
combination of quantitative fluorescence microscopy-based approaches and
mathematical modeling to address these issues. The first uses kinetic
analysis to investigate the mechanism of binding of Ras, a protein often
mutated in human tumors, to intracellular membranes. This work relies
mainly on the use of partial differential equations to model protein
diffusion and membrane binding via either a partitioning or
receptor-mediated mechanism. The second uses a Monte Carlo approach to
simulate a technique known as FRET that reports on the inter-molecular
distances of fluorescently-tagged molecules. This study addresses the
problem of how data on inter-molecular distances from FRET can be used to
study the two-dimensional spatial
organization of proteins in membranes.
Wednesday, October 25, 3:10 PM, SC 1310.
Special joint seminar with the Computational Analysis Seminar.
Manos Papadakis, University of Houston
Title: Isotropic wavelets against coronary artery disease.
Abstract: Acute myocardial infarction is caused by severe occlusion
of coronary arteries due to the rapture of the fibrous cap that
seals cholesterol pools in arterial walls from the lumen. These
pools are a type of atherosclerotic plaque called vulnerable from
the fact that the fibrous cap separating the pool from the lumen
may be destroyed. This situation is often associated with
mid-levels of stenosis and for this reason many patients have no
previous warning symptoms.
A great effort in modern medical imaging is being made for the
detection of vulnerable plaque. We will present some new
algorithmic techniques to image this type of plaque. Our methods
are based on 3D-texture segmentation based on the Isotropic Wavelet
transform. This transform is induced by multiresolution analyses of
$L^2(\mathbb{R}^3)$ defined by radial refinable functions giving
rise to well-localized isotropic wavelets which are also analytic.
This transform is implemented via fast algorithms.
Our experimental results are from an ex-vivo study of CT-scans of
coronary arteries. However, our methods, with appropriate
modifications, can be applied to other modalities such as
intravascular ultrasound.
Wednesday, October 11, 3:10 PM, SC 1310.
Rico Zacher, Universitaet Halle
Title: Analysis of a taxis model for tumor-induced blood vessel growth with vanishing cell motility.
Abstract: I will discuss the existence of classical solutions to a
taxis-diffusion-reaction model for tumor-induced blood vessel
growth. The model consists of
one equation for the endothelial cell-density and another one for
the concentration of tumor angiogenesis factor (TAF). I will
consider the special and interesting case that endothelial cells
are immobile in the absence of TAF, i.e. vanishing cell motility.
In this case the mathematical structure of the model changes
significantly (from parabolic type to a mixed
hyperbolic-parabolic type) and existence of solutions is by no
means clear. I will present conditions on the initial and boundary
data which guarantee local existence, uniqueness and positivity of classical
solutions of the problem. The approach is based on the method of
characteristics and relies on known maximal $L_p$ and H\"older
regularity results for the diffusion equation.
Wednesday, September 27, 3:10 PM, SC 1310.
Phil Crooke, Vanderbilt University
Title: Mathematical models of signal transduction.
Abstract: One can define signal transduction in many ways. In the most fundamental sense, it is the conversion of one type of signal into another type of signal. This
conversion or transformation often involves enzymatic biochemical reactions within the cell or a communication process through the cell membrane or even the cross-talk of information between two cells. We classify signaling domains into extracellular, intracellular, and intercellular signals. We look at some mathematical models for these biological highways of information. In particular, we will examine a famous model for the control of the cell cycle, a model for chemotactic signaling of Dictyostelium discoideum slugs, a model of signal transduction involving membrane-based receptors and G proteins that produce Turing-type patterns, and some preliminary work on a type of haploinsufficiency in gene regulation.
Wednesday, September 13, 3:10 PM, SC 1310.
Daphne Manoussaki, Vanderbilt University
Title: Mammals use spiral cochleas to enhance low frequency hearing.
Previous semesters:
