Upcoming Colloquia

Affiliation: Case Western Reserve
Time: 4:00 PM
Location: C215 ESC or Live Online

From static images to functional models: Using cryo-EM to reveal dynamic protein machines

Recent advances in structural biology such as cryo-electron microscopy (cryo-EM) and artificial intelligence have radically advanced our ability to visualize molecular protein structures. In this colloquium, I will first highlight how fundamental physical and mathematical principles in imaging, signal processing, and thermodynamics have enabled this biological triumph. I will then turn to the emerging frontier: linking the thermodynamic sampling of protein ensembles to biological function. Proteins are not static objects, but dynamic systems that explore complex energy landscapes through conformational changes and protein–protein interactions. I will outline how cryo-EM is addressing these frontiers through two stories from my research. The first involves a viral polymerase that leverages viral and host proteins to guide itself into a functional protein complex. The second demonstrates how an ion channel transduces chemical signals into electrical signals by sampling various conformational states. A common theme is how physics and biology intertwine in generating the relevant experimental data and interpreting the final results.

Biographical Sketch:

Dr. Eric Gibbs received his B.S. in physics from Brigham Young University in 2013. His undergraduate research investigated using symmetry mode analysis to characterize magnetic crystal structures under the guidance of Dr. Branton Campbell. In 2019, Eric obtained his PhD from Duke University in Biomedical Engineering under the guidance of Dr. Chunlei Liu. The Liu lab studies how MRI technology interfaces with molecular processes and Eric’s thesis work focused on exploring the use of radiofrequency waves to modulate ion channel activity. Since then, Eric has pursued postdoctoral research under Dr. Sudha Chakrapani at Case Western Reserve University. His primary focus has been using cryo-EM to study the structure and function of proteins with a particular emphasis on synaptic signaling.

Affiliation: ORNL
Time: 4:00 PM
Location: C215 ESC or Live Online

Research Experiences and Opportunities at Department of Energy National Laboratories

The Department of Energy oversees a large system of national laboratories and centers where each year, thousands of undergraduate students participate in internships in science, technology, engineering, and mathematics.  Dr. Cullen will discuss how his undergraduate research experiences in the national laboratory system shaped his scientific career, from selecting a graduate program to securing his current position as an electron microscopist at Oak Ridge National Laboratory.  He will discuss his current research in materials characterization at the nanoscale using scanning transmission electron microscopy.  A range of examples will be presented, including observing individual atoms in graphitic carbons, visualizing nanoparticle catalysts in 3D, and automating electron microscopy workflows to increase sampling. The latest national laboratory research opportunities for undergraduate students will also be discussed, along with tips for filling out a successful internship application.

Biographical Sketch:

Dr. Dave Cullen is a Distinguished R&D Staff Scientist at Oak Ridge National Laboratory in East Tennessee. He received a B.S. in Applied Physics in 2005 from Brigham Young University, and a Ph.D. in Materials Science and Engineering from Arizona State University, after which he joined Oak Ridge National Laboratory as an Alvin M. Weinberg Fellow. His current research is focused on catalyst development through automated microscopy methods for efficient and cost-effective energy conversion funded under the Department of Energy’s Critical Minerals and Energy Innovation Office.

Affiliation: UVU
Time: 4:00 PM
Location: C215 ESC or Live Online

Addressing the Hubble Tension with JWST

The sharp conflict between the current expansion rate of the universe (the Hubble constant, or H0) measured using the local extragalactic distance ladder and the value of H0 derived from the cosmic microwave background has the potential to reveal the presence of additional physics beyond the LCDM standard model of cosmology, so reducing and eliminating sources of systematic uncertainty in the local distance scale is of paramount importance. I will describe our efforts to calibrate the surface brightness fluctuation technique using the tip of the red giant branch to enable measurements of H0 at distances beyond 200 Mpc with JWST while minimizing systematic uncertainties. The results of our TRGB+SBF project are completely independent of the Cepheid+supernova distance ladder and form one of the key components of a new “Distance Network” that has now been used to accurately assess the covariances between various distance measurements and techniques. The Distance Network results reaffirm the reality of the Hubble tension at the 6-sigma level and further reduce the systematic uncertainties on H0, providing evidence that additional physics beyond cold dark matter and traditional dark energy may exist. 

Biographical Sketch:

Dr. Joseph Jensen is an astronomy professor in the Physics Department at Utah Valley University. He currently uses the Hubble and James Webb Space Telescopes to study the size and expansion rate of the universe by measuring distances to galaxies hundreds of millions of light years away. He received his Ph.D. in astronomy from the University of Hawaii at Manoa. Dr. Jensen worked at the Gemini Observatory for 12 years during the construction and commissioning of the twin telescopes. Dr. Jensen has been at UVU for 16 years and works with undergraduate students on optical and infrared imaging projects in cosmology.

Affiliation: University of Maryland
Time: 4:00 PM
Location: C215 ESC or Live Online

Affiliation: Siemens Corp
Time: 4:00 PM
Location: C215 ESC or Live Online

Affiliation:
Time: 4:00 PM
Location: C215 ESC

Affiliation:
Time: 4:00 PM
Location: C215 ESC

Affiliation: BYU Physics and Astronomy
Time: 4:00 PM
Location: C215 ESC