AWM at SIAM 2010 Abstracts

Monday, July 12, 2010, 4:00 pm – 6:00 pm, Room: 303

AWM Career Development Minisymposium: Success Through Transitions

Deciding to Give Up Tenure: Surprising Decisions Along the Path

Mary Ann Horn, Vanderbilt University, USA and National Science Foundation, USA,

Abstract. In a world where a successful research program and tenure often seem to be the main goals of a Ph.D. scientist, one may find it hard to see the other options available. After receiving my degree, my choices were not unusual and I spent three years as a postdoc before accepting a tenure-track position and, later, receiving tenure. But life sometimes throws unexpected opportunities in your path and I will describe a number of my own experiences, including how I eventually reached a decision to resign a tenured position.

Panel Discussion: Success through Transitions

Elebeoa May, Sandia National Laboratories, USA,
Gigliola Staffilani, Massachusetts Institute of Technology, USA,
Mary Ann Horn, Vanderbilt University, USA and National Science Foundation, USA,

Abstract. This panel session provides an opportunity for AWM workshop members to ask questions and discuss issues with professional development speakers.

Tuesday, July 13, 2010, 10:30 am – 12:30 am, Room: 303

AWM Workshop Recent Ph.D. Minisymposium: PDEs and Applications

Numerical Methods for a Problem arising in 3D Breast Image Reconstruction

Julianne Chung, University of Maryland, USA,

Abstract. Digital tomosynthesis imaging, the process of reconstructing a 3D object from a few 2D projection images, is a viable alternative to standard mammography in breast cancer imaging. However, current algorithms for image reconstruction do not incorporate the polyenergetic nature of the x-ray beam entering the object, resulting in reconstruction inaccuracies. In this talk, we discuss a novel mathematical model based on a polyenergetic x-ray spectrum and develop statistically based iterative optimization methods for image reconstruction.

Non-linear Wave Interactions in Rotating Stratified Fluid Flow

Dawn Ring, Wentworth Institute of Technology, USA,

Abstract. By utilizing the asymptotic renormalization theory of Wirosoetisno et. al. (2002), we propose a dynamical explanation of the origin, nature, and energetics of the spontaneously generated inertia gravity waves which appear in the trough of the baroclinic mode in the rotating annular experiment of Williams et. al. (1995). We compute the O(ε)
Wirosoetisno et. al. correction term to the underlying quasi-geostrophic dynamics and compare our results with the location, amplitude, and morphology of the IGWs observed in the lab. We also present energy results which offer a strong indication that in a real fluid, spontaneously emitted IGWs are an extremely efficient way to transfer geostrophic energy to ageostrophic energy, ultimately to be dissipated by viscosity.

Modeling Combustion Reactions with Step-function Kinetics

Erin Lennon, Northwestern University, USA,

Abstract. Here we develop reaction-diffusion models for self-propagating reactions where the reaction rates are reduced to have a step-function dependence on temperature. This approach is first studied in the case of a single reaction in both adiabatic and non-adiabatic environments. Of particular interest, however, are systems of two reactions which are thermodynamically coupled. This includes parallel, competing and sequential reactions with both analytical and numerical studies.

The Mechanical Stability of Growing Arteries

Rebecca Vandiver, Bryn Mawr College, U.S.,

Abstract. In many cylindrical structures in biology, residual stress fields are created through differential growth. The possible role of axial residual stress in regulating stress in arteries and preventing buckling instabilities is investigated. It is shown that axial residual stress lowers the critical internal pressure leading to buckling and that a reduction of axial loading may lead to a buckling instability which may eventually lead to arterial tortuosity.

Tuesday, July 13, 2010, 4:00 pm – 6:00 pm, Room:303

AWM Workshop Recent Ph.D. Minisymposium: Stochastic and Probabilistic Methods and Applications

Mechanisms of Simple Perceptual Decision-making Processes

Xueying Wang, Statistical and Applied Mathematical Sciences Institute, USA,

Abstract. Perceptual decision-making, an omnipresent component of everyday life, plays a pivotal role in cognitive tasks. In this presentation, I will talk about mechanisms underlying simple two-option perceptual decision-making processes by studying a biological-realistic reduced two-variable model and phenomenological drift-diffusion models.

Using Sequence Coverage Statistics to Determine Protein Binding Sites in a Genome

Valerie Hower, University of California, Berkeley, USA,

Abstract. Inspired by the notion of persistence in topological data analysis, we introduce a tree depicting sequence coverage via fragment placement on a genome. We then describe statistically the trees that correspond to random fragment placement and use this theory to determine the binding sites for a given protein in a genome. Our method for calling statistically signifcant protein binding sites reduces to the study of certain tree-based statistics derived from the data.

Oscillations in NFkB Signaling Pathway

Yunjiao Wang, Ohio State University, USA,

Abstract. Upon stimulation, oscillations of NF-kB localization are observed at both single cell and population levels. A recent work reported that different frequencies of the oscillations leads to different gene expression. Many authors point out that NF-kB may interact with other pathways. However, the existence and mechanism of those potential interactions are not clear. In this talk, we study this issue by considering the pathway subjected to two types of putative signals: sinusoid and pulsatile signals.