Scholars Share: Conversations on Graduate Student Research, a partnership between the Graduate College and Graduate Student Association (GSA), is an opportunity for current graduate students from across Drexel's colleges and schools, as well as postdocs and recent alumni, to come together to share their research endeavors and student experience moderated by a student leader and peer who facilitates questions and discussion from the audience.

For more information about Scholars Share and to sign up to present, visit the Scholars Share: Conversations on Graduate Student Research main page.

The STEM Spectacular Scholars Share Event

Tuesday, October 25, 2022
2 to 3 p.m. EDT

Virtual via Zoom

Watch the Recording [Drexel Streams]

Download Event Flyer [PDF]

Featured Speakers:

Mike Le

PhD Program in Biology
College of Arts and Sciences

Environmental Enrichment Stimulates Neuron’s Communication with Astrocytes – An Under-Appreciated Cell Type in The Central Nervous System

​Description: ​Exploring how cells in the central nervous system work together is key to understanding how the brain achieves its function. Astrocytes, the most abundant subtype of glial cells in the central nervous system, play a crucial role in regulating the formation and function of neurons. Growing evidence suggests astrocytes can facilitate changes in neurons in response to enriched living experience, known as experience-dependent plasticity. However, the mechanism by which astrocytes accomplish this is poorly understood. The Sonic hedgehog (Shh) signaling pathway is a compelling candidate for mediating this bidirectional communication. In the adult cortex, Shh is expressed by neurons and transduced by a subpopulation of nearby astrocytes. To examine whether Shh signaling can be regulated by neuronal activity, we housed mice in an enriched environment to promote robust somatosensory activity. We found that enriched sensory experience stimulated Shh signaling, indicating that neuron-astrocyte Shh signaling can be mediated by cortical activity. To investigate the functional significance of this observation, we identified potential activity-dependent genes regulated by Shh signaling through bulk RNA sequencing. We identified SPARC and Hevin – astrocyte-secreted matricellular proteins that regulate synaptic formation, function and plasticity – as selectively enriched in Shh-transducing astrocytes and dependent on Shh signaling. Ongoing work will determine whether SPARC and Hevin can be regulated in vivo by enriched experience and identify the changes to neurons that SPARC and Hevin mediate. In summary, our work revealed a novel activity-dependent feature of neuron-astrocyte Shh signaling, deepening our understanding of neuron-astrocyte bidirectional communication in experience-dependent plasticity.

Bio: Mike Le is a fourth-year PhD candidate in the Dr. Denise Garcia's lab in the department of biology in the College of Arts and Sciences at Drexel University. Mike’s project specifically focuses on elucidating the role of astrocytes, a specialized class of non-neuronal cells in the central nervous system known as glia, in facilitating neuronal plasticity that occurs in environmental enrichment. His interest in glial cells started when he was an undergraduate student in neuroscience at University of Cincinnati and as a research assistant at Wayne State University School of Medicine, in the labs of Dr. Elke Buschbeck and Tiffany Cook. In 2021, Mike presented his graduate research work at the Graduate School of Biomedical Sciences and Professional Studies’ annual Discovery Day and was awarded second place for "Outstanding Senior Graduate Student Poster". In 2022, Mike was awarded the Teck-Kah Lim Graduate Student Travel Subsidy Award to support a poster presentation at Cold Spring Harbor Laboratory’s Glia in Health and Disease meeting. In lab, Mike is passionate about providing research opportunities for undergraduate students, and has mentored many to become self-motivated, highly independent, and critical-thinking researchers. When not learning about glial cells, Mike enjoys researching about the financial market, investing in companies that are the building blocks of the American economy.

Dominique McDaniel

PhD Program in Biostatistics
Dornsife School of Public Health

Bayesian Approach to Principal Stratum in a Clinical Setting

Description: Patients in clinical trials may discontinue their randomized study treatments due to intercurrent events such as adverse side-effects. Accordingly, clinical trials for drug approval must evaluate treatment effects while accounting for intermediate outcomes, to prevent biased inferences that could arise from confounding of latent variables. Existing statistical methodologies for clinical trials such as intention- to – treat typically ignore treatment discontinuation and focus on treatment assignment. In this research presentation, we will discuss principal strata that arise due to intercurrent events in randomized comparative trials. Further, we will introduce a Bayesian testing methodology that can account for the existence of principal strata in such clinical trials. The potential utility of this methodology will be illustrated on simulated clinical trials from a novel data generating model that accounts for multiple intercurrent events under the potential outcomes' framework.

Bio: Dominique McDaniel is a PhD candidate in biostatistics at the Dornsife School of Public Health at Drexel University. Dominique completed her undergraduate studies in mathematics at Cheyney University of Pennsylvania. She also holds a Master of Science degree in applied statistics and mathematical statistics from West Chester and Purdue University, respectively. Prior to starting her doctoral studies, Dominique worked in the pharmaceutical industry at Eli Lilly & Company in Indianapolis, IN. Dominique's research interests include Bayesian & Spatial Statistics, Clinical- Trial Development, and Causal Inference.

Weixiang Yu

Chasing the “Monsters” in our Universe

Description: As the most powerful/energetic objects in the Universe, quasars are believed to be powered by supermassive black holes (SMBHs) that weight from ten million to one billion times the mass of the Sun accreting matter onto themselves, in the process of doing so, shine at one trillion times the brightness of the Sun. The brightness of quasars are not static but rather in random fluctuation. In the talk, I will show how we can infer the size, mass, intrinsic brightness of quasars and study the environment near the central SMBHs through modeling their brightness fluctuation using novel statical methods.

Bio: Originally from Langfang, China, Weixiang Yu is a sixth-year PhD candidate in the department of physics in the College of Arts and Sciences at Drexel University. He earned his B.S. in physics from the University of Illinois at Urbana-Champaign (UIUC). While at UIUC, he was fascinated by the idea/reality that the physical world is four-dimensional (i.e., space-time) rather than three and became determined to pursue a career in astrophysics. At Drexel, he studies the most powerful objects in the Universe—Quasars, which are thought to be powered black holes that are one billion times the mass of the Sun accreting matter onto themselves, and in the process of doing so, they shine at one trillion times the brightness of the Sun. Weixiang studies quasars by monitoring their brightness variation as a function of time and modeling their variability using novel statistical methods. Through sophisticated modeling, he can learn about the size, mass, and intrinsic brightness of those “monsters”; the inferred physical properties of quasars are crucial to the understanding of how our Universe has evolved from a single point in space-time to what it looks like today. Weixiang is also very active in public outreach, for example, he has been helping run the monthly Drexel University Lynch Observatory open house since he first arrived at Drexel. Weixiang was awarded a Teck-Kah Lim Graduate Student Travel Subsidy Award to support his participation in the 240th American Astronomical Society meeting, where he presented his most recent work on modeling quasar variability.

Student Moderator:

London Thompson, M.Ed.

Vice President for Academic Affairs
Graduate Student Association

EdD Program in Educational Leadership & Management, Athletic Administration
School of Education

Bio: London is a Philadelphia native who currently lives in Honolulu, Hawaii. His research focuses on educational issues including education policy, identity development, the academic experiences of African American students, critical theory, the lived experience of the student-athlete, and organizational identity development toward social justice. London joined the GSA to get more involved, make more friends, share, and grow his talents. His other passions include coffee, his children, athletics, music, and education.