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October 15, 2012鈥擯rofessor of has been named the first Interdisciplinary Chair in Science at Georgetown University. Urbach, who is also the inaugural chair of the , received the honor from Georgetown 海角论坛 in recognition of his ongoing collaboration with other science departments.

Since coming to the Hilltop 16 years ago, Urbach has been interested in combining physics with other disciplines in order to solve real-world problems. These connections鈥攐ften years in the making鈥攈ave helped him create research methodologies that solve phenomena in creative ways. He has formed working relationships with Associate Professor of Biology , Professor of Chemistry , and hopes to start a project soon with Associate Professor of Biology .

鈥淚 wanted to branch out, in part because I was interested in learning how to apply the tools and techniques that I had to biological problems鈥擺not just] because these problems were interesting and were obviously important, but also because being at Georgetown, it made a lot of sense, especially because of my proximity to the [Georgetown University] Medical Center,鈥� Urbach said.

According to Urbach, in the last two decades interdisciplinary research has become more common for physicists at research institutions. He attributes this to the fact that different departments will often have complementary perspectives on shared scientific questions.

鈥淭here鈥檚 a lot about what鈥檚 going on in the biological environment that a physicist is not going to understand well. But in many situations, the understanding of the physical phenomena going on requires a physicist,鈥� Urbach explained. 鈥淭he way a physicist typically works is to make an idealized model of something. The trick is to do an idealization that is simple enough that you can solve the problem but is not so simple that it鈥檚 irrelevant to the real world. That requires a lot of back and forth [between departments], and that鈥檚 kind of the fun part.鈥�

For the past five years, Urbach has been working closely with Heidi Elmendorf in an effort to better understand the Giardia parasite, which is common in underdeveloped countries with poor health care and nutrition. Urbach and Elmendorf are investigating how the parasite manages to adhere to the intestinal lining of its hosts.

鈥淚n order to do its thing, the parasite鈥攖his little single-celled [organism]鈥攏eeds to attach itself to the wall of the intestine and stay there and resist the forces that would normally push things like food through the intestine. It turns out that the community does not know the mechanism by which it attaches,鈥� Urbach said. 鈥淔or most biological [systems], when one thing attaches to another, it鈥檚 some sort of chemically mediated attachment, some sort of bonding. But there was evidence in the literature [saying] that was not what was going on here.鈥�

Through their collaboration, Elmendorf and Urbach discovered that the parasite clings to the intestine using the microscopic equivalent of a suction cup and a vacuum cleaner.

While suction cups easily stick to impermeable surfaces like glass, the wall of the intestine is permeable, meaning liquids can flow through it as the Giardia parasite hangs on. In order to maintain the air pressure needed for suction beneath its 鈥榗ups,鈥� the parasite uses its flagella鈥攖ail-like structures鈥攖o 鈥渁ct like a pump,鈥� Urbach said, to rhythmically 鈥渂eat鈥� and 鈥渨ave鈥� out the fluid that leaks in.

鈥淣ow that we鈥檝e got this figured out, there鈥檚 a whole bunch of additional things we would like to do to build on what we鈥檝e learned,鈥� Urbach said. His next goal will be to simulate Giardia鈥檚 environment, the intestine. Just like other soft matter materials, the intestine has both solid and liquid properties, making it a perfect project for a physicist.

鈥淚n fact, it鈥檚 interesting鈥攁nd this is all stuff that I鈥檝e recently learned鈥攂ut the center part of the intestine is more of the stuff that鈥檚 in the liquid phase, and as you get to the wall it gets more and more solid-like, but it鈥檚 not a sudden transition. It鈥檚 a gradation.鈥�