BIOTRANS Research

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1. Davalos and student at worktable. 2. Schmale student gathers a water sample. 3. De Vita was honored by the American Society of Mechanical Engineers for her significant contributions as an internationally recognized expert in biomechanics. Photo credit: Emily Roediger. 4. Culex quinquefasciatus mosquito thermogram. Courtesy of Chloé Lahondère 5. Hosein Foroutan (left), David Schmale (middle), and Shane Ross (right) standing behind their drone, which is mounted with a 3D-printed sampling device Photo credit: Alex Crookshanks 6. Grants for interdisciplinary projects help new collaborations grow. Erica Corder for Virginia Tech. 12 7. Dr. Chloé Lahondère handling a frog at Mountain Lake Biological Station. Photo credit: Joanna Reinhold

BIOTRANS | STUDENT AWARDS

Hyunggon Park

Jin Pan Nico Baudoin Liviu Librescu Memorial Fellowship awarded by Engineering Mechanics Sussman Fellowship Virginia Tech Department of Biological Sciences Robert and Marion Patterson Scholarship for excellence in research Virginia Tech Graduate Student Development Award, Fall 2019

SELECT LIST OF 2020 PUBLICATIONS BY BIOTRANS LABS: Lahondère C., Vinauger C., Okubo R.P., Wolff G.H., Chan J.K., Akbari O.S., Riffell J.A. (2020). The olfactory basis of orchid pollination by mosquitoes. Proceedings of the National Academy of Sciences, 117: 708-716. doi: 10.1073/pnas.1910589117 Harrison J.F., Adjerid K., Kassi A., Klok C.J., VandenBrooks J.M., Duell M.E., Campbell J.B., Talal S., Abdo C.D., Fezzaa K., Pendar H., Socha J.J. (2020). Physiological responses to gravity in an insect. Proceedings of the National Academy of Sciences, 117: 2180-2186. doi: 10.1073/pnas.1915424117 Lin K., Marr L.C. (2020). Humidity-dependent decay of viruses, but not bacteria, in aerosols and droplets follows disinfection kinetics. Environmental Science & Technology, 54: 1024-1032. doi: 10.1021/acs.est.9b04959 Baudoin N.C., Nicholson J.M., Soto K., Martin O., Chen J., and Cimini D. (2020). Asymmetric clustering of centrosomes defines the early evolution of tetraploid cells. eLife, 9: e54565. doi: 10.7554/eLife.54565 Graybill P.M., Davalos R.V. (2020). Cytoskeletal disruption after electroporation and its significance to pulsed electric field therapies. Cancers, 12: 1132. doi: 10.3390/cancers12051132 Yeaton I.J., Ross S.D., Baumgardner G.A., Socha J.J. (2020). Undulation enables gliding in flying snakes. Nature Physics, 16: 974–982. doi: 10.1038/s41567-020-0935-4 13

Spurred by COVID-19, BIOTRANS researcher Linsey Marr evaluates efficacy of sterilized N95

respirators and alternative mask materials - Written by Suzanne Irby, Eleanor Nelsen, and Kendall Daniels

SINCE MARCH, VIRGINIA TECH PROFESSOR Linsey Marr, an expert in the airborne transmission of infectious disease, has been testing the efficacy of sterilized N95 respirators and alternative mask materials in filtering out particles. The science experiments conducted by Marr’s team aim to quantify how well different forms of personal protective equipment and homemade face coverings shield their wearers against COVID-19, especially in the face of shortages and sluggish PPE supply chains. Because of these shortages, the medical community and the wider public have turned to improvisation. Some hospitals have worked to extend the use of their stores of N95 respirators by sterilizing them. Members of the public, advised by the Centers of Disease Control and Prevention to wear cloth face coverings in public places, are also exploring creative solutions by sourcing off-the-shelf materials for homemade masks. As people adapt, Marr’s team is working to supply them with insights grounded in science. “Since I understand how the coronavirus moves around in air, I knew how important it was for health care workers to have proper respiratory protection,” said Marr, the Charles P. Lunsford Professor of Civil and Environmental Engineering. “I knew my lab could help by testing N95s after sterilization to ensure that they could be reused safely. I quickly wrote up a procedure, and my students reconfigured our equipment to start running experiments.” Marr’s lab broadly looks at the sources, transformations, and fate of air pollutants. Over the years, she’s focused on engineered nanomaterials and viral aerosols — mainly those of the flu for the latter — and how they can be physically and chemically transformed in the environment. When testing sterilized N95 respirators, Marr and graduate students Jin Pan and Charbel Harb found that the respirators retained their ability to filter particles after up to 10 cycles of sterilization with hydrogen peroxide vapor and ethylene oxide.

“We are testing the effectiveness of different homemade mask materials in limiting airborne particles of different sizes from being inhaled by the wearer. We do that under ideal conditions and realistic conditions, where we use a mannequin to simulate mask fit to a human face. We are also testing the effectiveness of these materials in blocking particles that are exhaled by humans,” said Charbel Harb, a Ph.D. Student in the Department of Civil & Environmental Engineering and a member of the fellow civil and environmental engineering professor Hosein Foroutan’s Applied Interdisciplinary Research on Flow Systems (AIRFlowS) Laboratory. “After realizing how many people died in this pandemic and how many healthcare workers were sacrificed in this war, I can no longer sit still. I am eager to help by using my own knowledge and I am glad that I can do it with funding from the IGEP program and support from my advisor, Dr. Marr,” said Jin Pan, a Ph.D. Candidate in Marr’s Applied Interdisciplinary Research in Air (AIR2) Laboratory and the BIOTRANS program. Since 2010, Marr has been an affiliated faculty member of BIOTRANS, an interdisciplinary Ph.D. program at Virginia Tech that brings biologists and engineers together to study transport in environmental and physiological systems. “Trying to understand the transmission of COVID-19, and other diseases, is a great example of an interdisciplinary problem that demands an understanding of the biology of pathogens and of their transport through the environment as they are moving between people,” said Marr. As she’s pivoted in recent months to apply her insights to the novel coronavirus, Marr has weighed in on subjects that have captured national media attention, such as the possibility of transmission by inhalation, the 6-foot distance recommendation for running outside, and how virus particles may or may not land on a person’s clothes or other surfaces. “Because this is such a public health problem, it is really important to communicate science to the public and to the public health agencies that are providing messages about COVID-19 to the public and developing policies. I realized early on that I was one of a small number of people in the world who have expertise on airborne viruses. And so I realized that it was very important for me to share my research in a way that people could understand,” said Marr. In their examination of homemade mask materials, Marr’s team has tested items that have emerged in the public eye in recent months, such as: Shop-Vac bags, HVAC filters, T-shirts, microfiber cloth, felt, auto shop rags and towels, and coffee filters. A few top performers and busts emerged from their tests. Microfiber cloth, a material used to clean eyeglasses, filtered out at least 80 percent of particles under optimal conditions. But a heavyweight cotton t-shirt, a shop towel, and a shop rag filtered out only about 10 percent of the hardest particles to remove and about 50 percent of the larger ones. HVAC filters removed a low of 20 percent of particles; Shop-Vac bags removed at least 60 percent. Some of the alternative mask materials arrived in Marr’s lab for testing via Matt Hull, a research scientist at the Institute for Critical Technology and Applied Science and Marr’s colleague on the institute’s NanoEarth team. Hull recognized that amid the COVID-19 pandemic, there would be a strain on supply chains for protective materials with specialized properties, including materials that the medical community might eye for lastresort use in PPE. He dropped off potential candidates at the Kelly Hall headquarters of the Institute for Critical Technology and Applied Science. What was once a conference room has now been transformed into a staging area for piles of material destined for testing in Marr’s lab down the hall. The experiments are ongoing, but Marr has been releasing the results in real time on Twitter. She also shared the procedure behind the tests on Twitter, and other aerosol science labs around the country have since adopted these methods to help test materials in their regions. “Twitter is time consuming, but I learn a lot from it. I learn about new scientific papers and I get to see different perspectives. I also have interesting scientific discussions and exchanges with other experts. The general public has really great questions that force us to think more deeply about the problem,” said Marr. As for now, Marr’s team will continue to run experiments as new ideas for mask materials emerge.

This image shows a flying snake (common name: paradise tree snake; scientific name: Chrysopelea paradisi) gliding through the air. The snake transforms itself by flattening, a shape that can be seen in the view of the snake’s belly. In addition to flattening, the snake undulates in the air, a motion that looks like swimming. A recent paper in Nature Physics demonstrated that this behavior is a critical component of the snake’s ability to glide. Without it, the snake would be unstable and would tumble out of the sky. This study was lead by former BIOTRANS graduate Dr. Isaac Yeaton (now at the Johns Hopkins University Applied Physics Laboratory) and was 18 co-authored by faculty members Drs. Shane Ross and Jake Socha.