Undergraduate Research Program

2006-07 WRF Fellows

Steven Asplund - Bioengineering

Development of microvalves for integration in microfluidic point-of-care diagnostic applications

The purpose of this project is to design, fabricate and test miniature valves. These valves will be used to control small volumes of fluid in credit-card sized devices that will eventually be used for rapid, on-site (point-of-care) medical tests. Thus, the valves must be small, applicable to a wide range of designs and be able to be quickly switched between devices.

Sam Burden - Electrical Engineering

Hierarchical Assembly for Self-Assembly Robots

In my group, we engineer robots that self-assemble into any desired shape. We’ve created techniques to optimize arbitrary assembly processes, but the tools don’t scale well. I propose to perform assembly hierarchically, thus making our previous work applicable at many more scales.

[In other words…]

Self-assembly is a fascinating field because it’s what drives most processes from the cellular down to the atomic level. We’re trying to understand what characteristics a system must have in order to self-assemble, what final products it can reasonably assemble into, how we can prevent and correct errors in that final assembly, and how we can optimize the process to take as little time as possible or generate the largest yield.

Jeff Eaton - Sociology, Statistics, Mathematics

Bayesian Melding to Improve Parameter Estimation in Stochastic HIV Epidemic Modeling

Mathematical models of epidemics are used my epidemiologists, doctors, and policy makers to distill complex disease phenomena into component parts in order to understand and predict what may happen in a variety of scenarios. This information is useful for making informed decisions about controlling and intervening in epidemics, such as the global HIV epidemic. For example, a government may use a model to predict the amount anti-retroviral drugs that would be needed to treat all those living with AIDS in a country, or an epidemiologist may use a model to understand why or why not a particular intervention strategy is effective. Microsimulation models are models that simulate specific individuals in a population by exposing them to random hazard of important events, such as infection, marriage, or death, in each time step. Because of the ability to specifically model complex individual behavior, microsimulation models are very useful for understanding intricate social dynamics. However, it is very difficult to accurately quantize individuals’ behavior and there is a severe lack of high quality population data in the parts of the world worst afflicted by infectious diseases such as HIV, so microsimulation models often can only be used to obtain theoretical results about hypothetical populations. Recently concerted efforts have been made to improve data collection in Africa, and statistical techniques have been developed for estimating parameters even in the case of imperfect data. Combining these it may be possible to develop microsimulation models that recreate actual populations.

Jessica Smith - Chemistry, Biochemistry

Folding Specificity of Homologous Nucleotide-Binding Domains

In order to move molecules across membranes, cells utilize a variety of transport protein complexes including ABC-transporters, or ATP-Binding Cassettes. ABC-transporters are vital to cell metabolism and function because most molecules required for life cannot simply pass through the cell membrane. At the molecular level, ABC-transporters consist of two intermembrane domains that form a channel in the cell membrane and two nucleotide-binding domains (NBDs) in the cytoplasm. This project seeks to better understand the interaction between the intermembrane domains and the NDBs by determining which amino acids in the NBDs are important to efficient transport

[In other words…]

Proteins perform almost all of the tasks necessary to sustain life. In many cases, proteins must work together to facilitate complicated processes. In this project, we are investigating how individual proteins that form a complex “know” how to interect with the right protiens and not with unrelated proteins.

Alex Teel - Earth and Space Science, Physics

Elasticity and Anisotropy of Common Crustal Minerals

Full interpretation of crustal seismology in terms of composition and fabric is difficult in the absence of high quality elasticity data for the constituent minerals. Over the last forty years, a limited data set based on 1-bar ultrasonic determinations has served as the principal foundation for such discussions. We have now measured single crystal elastic properties of several dominant crustal minerals in both feldspar and amphibole mineral series. We use impulsively stimulated light scattering to determine body wave or surface wave velocities as a function of propagation direction on crystals having dimensions of tens to hundreds of microns. Full tensor elastic constants for these low symmetry (monoclinic and triclinic) crystals were obtained by inverting the velocity data. We observe greater velocity anisotropy and find constants that are 10 to 25% larger than previously reported constants. Some of the constants that appear biased low in the older data set are associated with strains in common cleavage directions; this underscores the need for a full re-examination of crustal scale elasticity modeled from properties of constituent minerals. In particular, the new data suggest that minerals less abundant than feldspars and amphiboles have a significant role in obtaining an adequate fit to crustal velocity profiles and that large-scale elastic anisotropy of the crust must be addressed in the next generation of crustal velocity models.

Pavan Vaswani - Computer Science, Biochemistry

Pavan Vaswani working in labNon-Invasive Determination of Intracranial Pressure by Means of Vibroacoustography

Elevated intracranial pressure, the pressure on the brain in the skull, is associated with many neurological conditions. Currently, pressure measurements are made by drilling a hole in the skull and inserting a small pressure transducer.

We seek to replace this invasive method. Vibrating brain tissue noninvasively with High Intensity Focused Ultrasound can be used to determine the tissue’s resonant frequency, which serves as an indicator tissue stiffness, which is expected to be correlated with brain pressure. Stiffer tissue is expected to have a higher resonant frequency and be under higher pressure; and softer tissue is expected to have a lower resonant frequency and be under lower pressure.