Spring 2021
February 19, 2021 (Friday) 4:00-5:00p.m.
Speaker: Dr. Luisa Rebull, Scientist, Caltech/IPAC
Host: M. Sher
Title: Stellar Rotation in Young Clusters using K2 and TESS
Abstract: K2 has provided a phenomenal opportunity to study properties of stars in clusters, particularly young low-mass stars, far beyond the expectations of the original Kepler mission. The high-precision photometry provided by K2 allows us to probe stellar variability to lower masses and lower amplitudes than has ever been done before. Younger stars are generally more rapidly rotating and have larger star spots than older stars of similar masses, so spots rotating into and out of view reveal the (surface) rotation rate of these stars. K2 has monitored stars from several clusters, most notably Rho Oph
(~1 Myr), Taurus (~5 Myr), USco (~20 Myr), the Pleiades (~125 Myr), and Praesepe (~700 Myr). The light curves have yielded thousands of rotation rates, and revealed far greater diversity in light curves than was anticipated. Now that we have TESS data as well, we can add the Upper Centaurus-Lupus (UCL) and Lower Centaurus-Crux (LCC) young moving groups (~15 Myr). In this talk, I will review the K2 results and present early results from UCL/LCC.
March 12, 2021 (Friday) 4:00-5:00p.m.
Speaker: Rana Ashkar, Virginia Tech
Host: Justin Stevens
Title: Collective Dynamics in Lipid Membranes: From Fundamental Physics to Health and Disease
Lipid bilayers, the main matrix of cell membranes, host a wide range of vital biological processes and are ubiquitous in a variety of research areas at the interface of biophysics, health care, and biotechnology. In order to understand the function of lipid membranes and fully utilize their potential in pharmaceutical and biotechnological applications, it is imperative to understand biophysical membrane properties on the length and time scales over which key membrane functions occur. Among such phenomena, collective membrane fluctuations and molecular reorganizations remain poorly understood despite their crucial role in various cellular processes, including protein-membrane interactions, viral budding, and signaling events. This talk will highlight recent advances in molecular dynamics (MD) simulations and neutron scattering studies of collective membrane dynamics, in the form of bending and thickness fluctuations, and their implications on membrane functions. Specific focus will be placed on new findings related to the dynamic response of membranes to cholesterol content, lateral rearrangement, and protein binding events. The talk will also discuss the potential of neutron scattering in addressing existential problems, such as the current coronavirus pandemic, by directly probing the interactions of viruses with cell membranes and by offering solutions for enhanced designs of liposomal vaccine carriers.
Bio: Rana Ashkar is an assistant professor at Virginia Tech, where she joined the Physics Department in 2018. Prior to her current appointment, she held a Clifford G. Shull Fellowship at Oak Ridge National Lab, preceded by a joint postdoc position at NIST and the University of Maryland. Dr. Ashkar has a Ph.D. in experimental physics from Indiana University. Her doctoral work was awarded the Esther L. Kinsley dissertation award. Her research group focuses on biophysical investigations of model cell membranes, with specific emphasis on membrane mechanics, membrane-protein interactions, and dynamic membrane responses to interfacial and environmental cues. Besides her scholarly activities, Dr. Ashkar is committed to diversity and inclusion in STEM and promoting a better environment for underrepresented and marginalized groups in science. She was the founder and first chairperson of the "Women in Neutron Sciences” program at Oak Ridge National Lab. She recently served on the APS Committee on the Status of Women in Physics (CSWP) and chaired the APS Climate Site Visits Program, the flagship program of CSWP. Currently, she serves as a Member-at-Large in the APS DBIO executive committee. In her free time, Rana enjoys reading, gardening, and exploring the beautiful hiking scenes of the nearby Appalachian Trail.
March 19, 2021 (Friday) 4:00-5:00p.m.
Speaker: Dr. Joel S. Levine, William & Mary Applied Science
Host: J. Stevens
Title: The Human Exploration of the Moon and Mars: A Preview
The United States is planning a human mission to Mars. To achieve this goal, NASA has built a very powerful new multi-stage rocket, called the Space Launch System (SLS) and a new human capsule, called Orion, which will sit atop the SLS. As early as 2024, humans will return to the Moon, this time for an extended stay to prepare for the human exploration of Mars. Astronauts will explore Mars to address a series of very important scientific questions, including: Is there life on Mars today or in the past? Why did early Mars evolve from an Earth-like planet with abundant liquid water on its surface in the form of large oceans (up to several miles deep), rivers and lakes and a thick atmosphere to the Mars of today, devoid of liquid water with a very thin atmosphere? The human exploration of the Moon and Mars: how, why and when, will be covered.
Joel S. Levine
Levine retired from NASA after a 41-year career as Senior Research Scientist, Science Directorate, NASA Langley Research Center and Mars Scout Program Scientist, Mars Exploration Program, NASA Headquarters. He is a consultant to the NASA Engineering and Safety Center (NESC). His teaching career at the College began in 1990 as Adjunct Professor and head of the atmospheric and planetary science track in the Applied Science Program. He co-chaired NASA’s panel on Human Exploration of Mars: Science Analysis Group (HEM-SAG) and edited The Human Mission to Mars: Colonizing the Red Planet (2010), Dust in Atmosphere of Mars and Its Impact on Human Exploration (2018) and The Impact of Lunar Dust on Human Exploration (2021).
April 23, 2021 (Friday) 4:00-5:00p.m.
Speaker: Andrea J. Welsh, University of Pittsburgh
Host: C. Monahan
Title: Dealing with Mental Health as a Young Scientist
Abstract: In the past few years, more studies about poor mental health in academia have been conducted and found that PhD students are almost 3 times as likely to develop mental health problems than then general population. Topics often linked with poor mental health are work-life balance, job demands, long work hours, supervisor’s leadership, and financial concerns. Many of these stressors are often exacerbated for those with an underrepresented identity with the addition of factors such as stereotype threat, imposter syndrome, or microaggressions. I will discuss the challenges that lead to poor mental health for early career physicists as well as some possible solutions that can be implemented by individuals and the community.
April 30, 2021 (Friday) 4:00-5:00p.m.
Speaker: Amber Boehnlein, Computational Science and Technology Division Thomas Jefferson
Host: Justin Stevens
Title: Building the Roads for Self-Driving Scientific Facilities
Abstract: Addressing fundamental questions across the physical sciences motivates new experimental facilities and methods of theoretical inquiry. Major investments in experiments often require novel approaches in computing and software. An example is the development of the distributed grid computing model to meet the needs of the ATLAS and CMS detectors at the Large Hadron Collider. That spirit of innovation is being applied today to make use of technical advances in computing hardware and to modernize computing models for the current and upcoming generation of experiments. The once sharp line between online and offline computing tasks is being blurred by application of technologies such as streaming readout and machine learning.
Beyond that classic ‘operational’ approach to scientific computing, the DOE Exascale Computing Project, combined with advances in data science, has ushered in a new era of possibilities, including real time feedback that could be used to steer data collection, and setting up automated process ‘agents’ that could enable scientists to focus more on research.
At Jefferson Lab, we are organizing our computing and software efforts towards this vision within the context of the 12 GeV science program. This talk will cover the current Jefferson Lab activities and prospects for the future
