No colloquium this week - Dr. Narae Kang has been rescheduled for 4 October 2019.

Mark C. Williams, Northeastern University

How Proteins Use Thermodynamics to Fight Over DNA

Optical tweezers allow us to probe the interactions of proteins with single DNA molecules and apply very small forces. Measurement of force-dependent DNA conformations allows us to quantify interactions that govern cellular function. DNA forms a stable double-helix in order to store the genetic information for most organisms. However, in the process of replicating an organism’s genome, the two strands of the helix must be separated to form single-stranded DNA (ssDNA). This intermediate state is vulnerable to interference from many cellular processes and is therefore tightly regulated.

Andrew Baker, Rutgers University

Dusty Star-Forming Galaxies at High Redshift
Interstellar dust grains can collectively scatter, redden, and attenuate the light from a galaxy's stars-- in some cases, so effectively that a galaxy can become nearly undetectable at rest-frame ultraviolet and optical wavelengths. Starting in the late 1990s, astronomers have come to understand that luminous but optically obscured systems are much more prevalent at high redshifts (i.e., earlier times) than in the local universe, and that they make important contributions to the overall history of cosmic star formation.