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CPLC Faculty Sangjin Kim Gives the Physics Colloquium on Feb 12th at 4pm in 141 Loomis

2/12/2020 12:01:32 PM

 Please join us for the Physics Colloquium TODAY, February 12 at 4:00 pm in 141 Loomis.

The colloquium will be presented by Sangjin Kim, Assistant Professor of Biological Physics at the University of Illinois. The title of her presentation is “Connecting the missing dots between motor traffic and topology in the genome”.

Abstract: Life is defined by base sequences of DNA, a polymer that carries information on how to make proteins—a building block and a functional unit within living cells. As a first step toward making proteins, DNA is read by processive molecular motors, called RNA polymerases (RNAPs). For example, Escherichia coli, a bacterial model organism, has a genomic DNA of about four million bases, and a few hundreds of RNAPs (each covering about 30 bases) can be detected somewhere on the genome at a given time, creating a situation like cars on the highway. While the dynamics of this molecular traffic is important in understanding the structure and function of the genome, we still lack a clear understanding of how even a few RNAPs work in the genomic context. Experimental results suggested that RNAPs can exhibit collective group dynamics by exploiting dynamic changes in DNA topology. In this talk, I will describe our current understanding of RNAP dynamics in connection with the dynamics of DNA topology. I will also present my current experimental and theoretical efforts to make a complete model explaining the emergence of RNAP group dynamics in the genomic context.

Refreshments will be available at 3:30 pm outside room 141 Loomis.

2/6/2014 9:00:00 AM Siv Schwink

Julia Shelton, known to friends and colleagues as Jessie, is a theoretical high-energy particle physicist, with a background in string theory. Her research program is focused on particle phenomenology, and particularly on identifying and modeling beyond-the-standard-model physics.

“The upcoming decade will be a historic watershed in our understanding of physics at the electroweak scale,” comments Shelton. “The complementary probes of beyond-the-standard-model physics coming from colliders on one hand and cosmology on the other promises a fruitful interplay of collider, direct detection, and astrophysical observations in the upcoming years. I work towards developing a comprehensive picture of physics beyond the electroweak scale, with collider and dark matter studies both forming an integral part of my research program.”

Shelton’s background in string theory through her graduate work and her first postdoctoral appointment has influenced her approach to particle physics.

“My field change from string theory to particle physics meant that I came into the field somewhat late—I didn’t grow up as a grad student in phenomenology,” she explains. “A very large number of models of electroweak-scale physics  had been extensively developed at that point, and it seemed more urgent to me to take a bottom-up approach,  asking theoretical questions about how we can distinguish new physics models from the Standard Model and from each other in sharp and useful ways.”

“I’m very interested in evidence of new particle physics, wherever we can see it,” she comments. “Today, the Large Hadron Collider (LHC) is our primary discovery machine. Its initial run produced a flood of data, dramatically altering our picture of the electroweak scale.  Right now the LHC is  in the middle of a two-year shut down (while it undergoes upgrades to operate at higher energy), so it’s a good time to reassess the theoretical motivations for potential LHC signals, and develop  new search strategies that take full advantage of the discovery potential of the LHC.  . The experimental program at the LHC is broad and well motivated, but the LHC is a blunt instrument in that it’s often hard to find  things if you don’t know what you’re looking for —there are places where new physics could be hiding..”

With the promise of exciting new physics on the horizon, Shelton is happy to have Physics Illinois as her home base from which to explore it.

“Illinois is an exciting place to be,” remarks Shelton. “The department is both dynamic and friendly. The particle physics group here is very strong, and the level of communication between theorists and experimentalists is uncommon. . Additionally, the department’s geographic proximity to national labs and  Chicago is a great benefit in terms of having a larger community with which to collaborate.”

Shelton also looks forward to teaching: “Communicating a beautiful piece of physics is the heart of what I find attractive about teaching,” shares Shelton. “A solid foundation in physics is useful to students across a spectrum of disciplines, regardless of their future need for Newton's laws, because it teaches an analytical approach to the world and a quantitative approach to problems.”

Shelton received her bachelor’s degree cum laude in physics from Princeton University in 2000. She received her doctoral degree in physics from the Massachusetts Institute of Technology in 2006, working under thesis adviser Washington Taylor.

Prior to joining the faculty at Illinois, Shelton worked as a postdoctoral fellow in the High Energy Theory Group at Rutgers University (2006–2009), then in the Theoretical Particle Group at Yale University (2009–20012), and finally in the High Energy Theory Group at Harvard University (2012-2013).

Shelton is a recipient of the LHC Theory Initiative Travel and Computing Award (2011), the Andrew M. Lockett Award for Excellence in Theoretical Physics (2006), and a Graduate Student Award for the Lindau Meeting of Nobel Laureates and Students (2003). She was also selected a Goldwater Scholar (1998).