Comet Calendar, The Official Event Calendar for UT Dallas en-us This week's events for Natural Sciences & Mathematics at UT Dallas Biology Seminar Monday, Jan 26
(4 p.m. - 5 p.m.)

The Department of Biological Sciences presents Dr. Hock Chung from R.M. Bock Laboratories, University of Wisconsin-Madison, Madison, WI.

Presentation Title: "Ecological Adaptation and Speciation in Drosophila".

     The ecological and genetic factors underlying the formation of new species remain a central puzzle in biology. Evolutionary changes in traits that affect both ecological divergence and mate choice are hypothesized to produce reproductive isolation which will lead to the formation of new species. However, few examples of such dual traits have been demonstrated, and the genetic and molecular bases of their evolution have not been identified.

     I and my collaborators have shown that insect cuticular hydrocarbons (CHCs) can function as such traits, and we have deciphered the genetic and molecular mechanisms that underlie the evolution of these CHCs in ecologically diverging Drosophila species. The study of dual traits may advance our understanding of how adaptation to different environments leads to the formation of new species.


Physics Colloquium: Atomically Thin Semiconductors: New Devices and New Physics Wednesday, Jan 28
(4:15 p.m. - 5:30 p.m.)

Dr. Hugh Churchill (MIT)

The discovery of two-dimensional crystals—materials only one to a few atoms thick—continues to drive exciting developments in condensed matter physics, more than 10 years after atomically thin graphene was first peeled from graphite.  The techniques used to isolate graphene have now been generalized to other materials with layered structures including a nearly perfect insulator hexagonal boron nitride, an entire family of atomically thin semiconductors such as MoS2 and WSe2, and many more.  These materials can be picked up and stacked together to make a wide variety of electronic devices composed entirely of atomically thin, transparent, and flexible materials.  In this talk I will present an overview of these developments and describe our contributions to the field, including the demonstration of a photovoltaic device and light-emitting diode made from a three-atom thick sheet of WSe2.  Finally, I will give an outlook for how continued improvements in materials and device fabrication are opening up a playground for new devices and new physics in this area.