By Mallory Rosten, Student Communications Assistant, College of Sciences

We’ve all had that feeling. Maybe it was in your A.P. Bio class, or while listening to a calculus lecture. The feeling that begs you to ask Why should I care?

From March 9 to 24, Atlanta will explode in a burst of activity. Thousands will gather for robots, performances, and live demonstrations. It can’t be Music Midtown – it’s too late for that. And it’s too early for Shaky Knees. It’s the Atlanta Science Festival, a celebration of science in over 100 events across Atlanta that culminates in a blowout in Piedmont Park.

The 2018 Atlanta Science Festival offers a kaleidoscope of cures for boring science including two new events from the College of Sciences. Taste of Science and Silver Scream Science Spookshow will spark enthusiasm, joy, and curiosity through nerdy exploration of food and ear-shattering, hard-rock rendering of scientific concepts.

TASTE OF SCIENCE
Hosted by Georgia Tech students, Taste of Science uses live demonstrations and food tastings to explore concepts in biology, biochemistry, chemistry, genetics, mathematics, and physics.

“It’s going to be a weird mix of food,” says Jennifer Leavey, the College of Sciences’ integrated science curriculum coordinator and one of the advisors to the event.

One example is Dragon’s Beard, an East Asian candy that’s like taffy, except this candy is coated in confectioners’ sugar. So as the strands are pulled apart, they stay separate and grow exponentially – a living and edible exponential function. Members of the Society of Asian Scientists and Engineers will demonstrate the pulling, often seen on Asian streets.

“It’s exciting because exponential functions have all kinds of science and engineering applications,” Leavey says. Who would’ve thought math could be so sweet?

From Asia, participants travel to the world of science fiction by just walking over to the next booth. Straight out of Willy Wonka’s factory, the miracle berry does something weird: It turns sour into sweet. At this booth, participants will find sour cream and lemon juice to try before and after eating the berry.

“It really works. I took a bottle of lemon juice and chugged it, and it tasted like candy,” says Michael Evans, the coordinator of freshman chemistry laboratory in the School of Chemistry and Biochemistry and another advisor to the event.

So how does it work? The berry contains the protein miraculin, which binds to sweet-tasting receptors. The receptors, however, respond to acid, so the acid will taste like sugar.

Kombucha, bagels, and nitrogen ice cream are just some of the many other foods with hidden science that students in Leavey’s VIPSTEMcomm class will demonstrate in Taste of Science. Other groups involved are SMaRT LLC, Club Math, Graduate Association of Physicists, and Molecular Gastronomists.

SILVER SCREAM SCIENCE SPOOKSHOW
Leavey and Evans are also members of a science punk rock band featuring their genetically modified clones.

When Leavey took biochemistry in college, she learned about DNA-binding proteins called leucine zippers and zinc fingers. “I thought that would be a great band name,” Leavey recalls. The chance to create a band came in 2014, the first Atlanta Science Festival. Leucine Zipper and the Zinc Fingers now is a staple of the Atlanta Science Festival, headlining variety or comedy shows.

In 2018, they’re performing in the Silver Scream Science Spookshow, marrying their outrageous punk rock with an equally outrageous alien movie from the 1950s, “It Came from Outer Space.” Hosted at the historic Plaza Theater, the audience will be transported to the campy world of science fiction.

On stage, Leavey becomes Leucine Zipper, and Evans transforms into X.O. Therm. Alongside them are Gringo Perdido (Joe Mendelson, an adjunct associate professor in the School of Biological Sciences), and Sonic Hedgehog (Ben Prosser, an A.P. Biology teacher and former student of Leavey’s).

For Evans, punk and science are a natural fit. “One of the reasons I got into science was this don’t-take-anyone-at-their-word attitude,” he says. “You verify things independently. That plugs into the punk mindset, making it easy and fun to write songs.”

The band’s song “Let’s Test It” encapsulates this attitude. The lyrics encourage listeners to perform their own experiments to learn about the world and not blindly accept what others say.

The band hopes to teach people that science isn’t just the domain of professors writing on a chalkboard. It’s everywhere, and the very act of performing experiments can be revolutionary.

“The essence of science is looking around you and asking questions,” Leavey says. “I think a lot of students stop asking questions once they get in the classroom. I really want people to be curious everywhere they go. To ask why. The more questions they ask, the more we’ll learn about our world.”

So far, the punk-rock-for-science experiment is working. People come for the fun, loud music, Leavey says. After shows, many nonscientists come to ask them questions. And maybe, just maybe, a young student will take an interest in the field.

“I think a lot of young people in high school or middle school don’t see themselves as scientists,” Leavey says. “Most scientists don’t look like them or talk like them. As a result, they don’t think they can become one.”

As Leavey talks, Evans sighs in exasperation. “That makes me sad,” he says, “because when you’re young you still have the energy, the time, and the mindset to be as scientist.”

On March 3 and 4, the band recorded in a studio for the first time, so that their songs can be available online. A grant from Georgia Tech made this recording possible. 

Taste of Science will take place on Tech Green, right next to Kessler Campanile, on March 10  at 12:00 – 4:00 pm. Silver Scream Spookshow will take place at the Plaza Theatre on March 17 at 12:30 – 3:00 pm, with an additional midnight performance.

This story by Kelly Freund originally appeared in the Winter 2017 Issue of Georgia Tech's Alumni Magazine.

--SPECIAL WEATHER STATEMENT--
NATIONAL WEATHER SERVICE
PEACHTREE CITY GA
JULY 2003

WHAT: A slow moving warm front will pull through the Georgia Tech campus as new students gather for FASET orientation near the student center. Expect this front to affect two students in particular: Laura Griffith and James Belanger. As the group of future Ramblin’ Wrecks gather around large signs depicting their major—with some 300 incoming freshmen milling about all the engineering fields—Laura will find just two other students under the Earth and Atmospheric Sciences banner. The small group will make the 10-minute walk to the department building and no one will say anything. Laura will think this is weird. The boy walking next to her seems like the less odd of the two students with her. So she will say, “Hi, I’m Laura.” “Hi, I’m James.”

PRECAUTIONARY ACTIONS: This is the beginning of something special. But James is a very risk-averse guy. 

This could take a while. 

Laura Belanger likes to tease her husband, James, that his first love was Weather Channel meteorologist Jeanetta Jones. Instead of watching cartoons as a kid, he would sit and watch the Weather Channel for hours. But according to James, it was not because of Jeanetta. Since the age of four, James knew he wanted to be a meteorologist. He spent the first few years of his life in North Carolina before moving to Georgia, and he remembers staying up late to watch the old TV version of radar, looking for snow.

“During elementary school, when we had our closed-circuit television broadcast, I was the TV weather guy,” James says. “It was kind of a no-brainer that I wanted to go to a university where I could become a meteorologist.”

As for Laura, she wanted to be a dentist. But that was short-lived. In the eighth grade, she was given a homework assignment to talk to someone with an occupation that she might like to have someday. Through acquaintances, she set up an interview at the National Weather Service in her hometown of Peachtree City, Ga. What was supposed to be a 15-minute conversation lasted an hour and a half because she wouldn’t stop asking questions. She walked out of the meeting with an offer for a volunteer position. 

Both Laura and James turned to Georgia Tech to jumpstart their careers in meteorology. The closeness to their hometowns played a factor, but the big draw was the prestige of the school and the holistic approach of Tech’s earth and atmospheric sciences program. The curriculum didn’t just focus on one facet, but provided them with a breadth of knowledge in the field. While he was in class, James might have resented sitting through lectures on earthquakes and atmospheric chemistry when all he wanted to learn about was severe thunderstorms and hurricanes. But graduates of Tech’s earth and 
atmospheric sciences program leave with a fundamental knowledge of earth science—as well as a passion to solve the world’s problems.

Laura and James are no exception. While most people think of meteorologists as the people who deliver the local daily weather forecast on TV, the couple works largely behind the scenes, analyzing weather data and its impacts, getting us all prepared for weather’s next big event.
 

--SPECIAL WEATHER STATEMENT--
NATIONAL WEATHER SERVICE
PEACHTREE CITY GA
2006

WHAT: That same slow-moving warm front from 2003. Over the next few years, Laura and James will have a lot of interactions, from classes to study groups. But they will remain “just friends” for a long time. Then, their junior year, they will both become part of a study group for a particularly difficult class, and James (one of the only people Laura knows who will graduate from Tech with straight As) will teach everyone the material. It turns out he is only coming to the study group because Laura is there.

IMPACTS: This has gone on long enough. A friend will finally convince James to ask Laura out—which he will do over AOL Instant Messenger. She will respond with, “I have to check my work schedule.” James will think she’s going to say she has to wash her hair that night. 

She doesn’t.

THE WEATHER FRONT

Laura has been a part of the National Weather Service longer than she hasn’t. For the past 17 years, she’s worked her way from volunteer to intern to meteorologist.

There are 122 National Weather Service offices scattered across the country. Laura works at the only office physically located in Georgia, which covers forecasts and warnings, such as tornadoes and flash floods, for about two-thirds of the state. As a meteorologist, Laura produces routine forecast products (advisories and updates that you would see on TV or on weather apps). The National Weather Service provides decision support—supplying information to people who are trying to make decisions based on weather, like emergency managers or people putting on events. For example, when Atlanta hosts the College Football Championship in January 2018 and the Super Bowl in 2019, the Weather Service is already making plans so that plenty of forecasters will be on site for support in case of inclement weather impacting the area (even though the stadium’s retractable roof will provide ample cover come game time).

Laura also currently serves as the acting service hydrologist for the office. In this role, she goes out to the region’s flood-prone rivers to determine if the flood risk is literally rising, and then draws up detailed reports, also known in her world as impact statements. The National Weather Service uses these statements to provide more detailed information when warnings are issued.

“So when somebody says, ‘OK, you issued a flood warning for this river—what does that mean?’ We have specifics that say a house on the right bank of the river could have one foot of water above the foundation or this road is going to be closed,” Laura says.

When Laura was offered her full-time position with the National Weather Service, James was wrapping up his master’s at the State University of New York in Albany. To be near her, he decided to pursue his PhD at Georgia Tech and got a side gig working with a small startup company, CFAN, through Tech’s VentureLab program. 

CFAN eventually established a relationship with The Weather Company (which began as The Weather Channel in the 1980s), becoming their exclusive provider of tropical products (advisories, updates, etc.). In January 2016, IBM bought The Weather Company, acquiring their product and technology businesses. (The proprietary name, The Weather Channel, was included in the purchase. The television station was not acquired, however, but is now owned by Weathergroup, who has a long-term license and data agreement with IBM to use the name The Weather Channel and The Weather Company’s data products.) More funding became available to expand, including the creation of a new senior meteorological scientist position, which James took later that year in July.
 

The Weather Company is using artificial intelligence and machine learning to improve day-to-day weather forecasting around the globe. James and his team take in the forecast the National Weather Service is providing, but they also take in forecasts from a variety of other weather information sources, as well as other predictive models. The Weather Company then figures out a way to blend all this information together and deliver it to both consumers and businesses. James’ job is on the back end to work on the algorithms that are in place to generate those forecasts and combine them. 

“I’m taking my knowledge of AI and meteorology and trying to bring those two together—trying to identify how we can help industries that have been plagued by weather impacts and make better decisions as they consider their operations,” James says.

As you can imagine, there’s a lot of weather talk going on at the Belanger house. There’s not always agreement. But Laura and James describe these debates as “healthy discussions.”

Because James is in the private sector and Laura works for the government, Laura likes to say the two are not rivals, but teammates who work in tandem. The Weather Company is working on projects that help support the mission of the National Weather Service, and the National Weather Service is providing data to The Weather Company for their forecasts.

“Since James is on more of the research side of things, and trying to improve forecast models and products, I joke with him that he’s got to leave room for the meteorologist,” Laura says. “He can’t do so well at his job that he eliminates the need for forecasters.”
“And my point to that is that we want to use forecasters in different ways than we’ve used them in the past,” James says.

MAN VERSUS HURRICANE

The 2017 Atlantic hurricane season was one of the most active on record. In late August, Hurricane Harvey became the first major hurricane to make landfall in the United States since 2005. Hitting Texas as a Category 4 storm, it went on to affect 13 million people in six states and cause $180 billion in damage. Hurricane Irma followed a few weeks later and went down in the record books for its meteorological significance, including its number of days as a major hurricane and as the strongest storm in the Atlantic this year. 
 

When Irma hit Florida, traveling up toward Georgia, it was all hands on deck for Laura and James at their respective companies. Laura was deployed to FEMA Region IV headquarters in Atlanta to help the office prepare ahead of the storm, and James was called up to write editorial content for weather.com.

“I think there is a general consensus when you’re talking to meteorologists about significant weather systems,” Laura says. “Meteorologists are torn between the awe and beauty of the storm (something we’ve studied and trained for), and the ache of knowing people are in harm’s way.”

As a meteorologist, part of Laura was excited to see such a huge storm persist. But as a forecaster providing decision support to FEMA—knowing what was likely to occur and the potential impacts to the millions of people in harm’s way—it was an emotional experience. 

James echoes Laura’s sentiments, but points out that valuable information can come from these significant storms. “As someone who works to implement the science of weather prediction into operations, these hurricanes provide us with a new sample for testing our machine learning forecast systems,” he says. “In the end, these cases ultimately result in improvement in the accuracy of our weather forecast content even though they end up causing billions of dollars in damage.”
 

Meteorologists like Laura and James know that we can use the new insights gained from significant weather systems to drive better decisions and outcomes not only in the short term (whether or not to put on a coat because of a given day’s temperature or threat of precipitation), but also in terms of the decisions we make when we think about things like where an airport should be located, how we should be designing our cities or implementing building codes. 

“You can’t keep the weather from happening,” Laura says. “But you can lessen the impact.”

EXTENDED OUTLOOK

Weather is an equalizer. It doesn’t care about your socioeconomic status. It doesn’t care where you live. It doesn’t care what college you went to or what you do for a living. It is one of the only things on this planet that affects everyone.

Because of this far-reaching impact, the change in weather statistics over time is an active area of research. The consensus among the scientific community is that there have been changes in things like the planet’s atmosphere, ecosystems and human food systems. James says that regardless of the underlying causes, these changes should motivate conversation and action centered around sustainability policies that increase resilience and reduce our environmental footprint. “A society that is more resilient to high-impact natural hazards like drought, winter storms and landfalling hurricanes is more likely to better withstand the impact of low-frequency climatic changes,” he says.

“You can look at the numbers, and I think it’s 90 percent of the presidential declarations are natural disasters,” Laura says. “We are lucky to be in a field where we can bring some education and some greater understanding to what those impacts mean for people and try to get people to understand what their greatest risks are.” 

Researchers have found previously known skin itch receptors in the airways of mice. The receptors appear to contribute to bronchoconstriction and airway hypersensitivity, which are hallmarks of asthma and other respiratory disorders. The experiments in mice suggest that the receptors’ activation directly aggravates airway constriction. If the same process is active in people, the receptors may be a promising new target for development of drug therapies for asthma and related disorders.

In a report on the study in Nature Neuroscience, researchers say the receptors – called MrgprC11 – are present on nerve cells in the lower respiratory tracts of lab mice.

“The findings give us a fuller picture of what airway reactivity looks like,” says Xinzhong Dong, Ph.D., professor of neuroscience at the Johns Hopkins University School of Medicine Institute for Basic Biomedical Sciences.

Working closely with Dong was Liang Han, the paper’s first author and an assistant professor in the Georgia Tech School of Biological Sciences, where she conducted some of the reported work.

Asthma patients report an itchy sensation in their lungs just prior to a full-blown asthma symptom such as wheezing. This observation inspired the research team to study “itchiness” in the airway.

“Current investigations of the pathogenesis of asthma have largely focused on immune responses,” Han says. “However, anti-inflammatory treatment only partially controls asthma symptoms. We need to understand the involvement of non-immune systems in the disease, such as the potential role of MrgprC11.”

Using fluorescent antibodies that light up MrgprC11 in mice, the investigators observed MrgprC11 on vagus nerves, which serve as a main biochemical connection between airway cells and the brain.

To explore the effects of MrgprC11 on the airway, the researchers used an itch activator that specifically targets MrgprC11 to induce a reaction. They found that mice with MrgprC11 breathed more quickly and with more effort after exposure to the itch activator than did the mice lacking it.

“This result led us to the hypothesis that activation of MrgprC11 induces bronchoconstriction,” Han says. Bronchoconstriction is the constriction of the airways in the lungs due to the tightening of surrounding smooth muscle. It leads to consequent coughing, wheezing, and shortness of breath.

Next, the researchers examined bronchoconstriction by measuring the airway resistance of mice with and without MrgprC11. The team saw increased airway resistance in mice with MrgprC11.

“These findings highlight the critical role of vagal sensory neurons in asthma,” Han says. “They reveal a neural mechanism underlying asthma and a potential therapeutic target for treatment.” Han says.

Other Georgia Tech coauthors of the study are Haley Steele, Yuyan Zhu, and Julie Wilson, who are, respectively, a Ph.D. student, a postdoctoral researcher, and a laboratory technician in Han’s lab.

This research was supported by the National Institutes of Health (NS054791 & NS087088), the National Heart, Lung and Blood Instiute (112919 &122228), and by the American Asthma Foundation.

Three graduate students from College of Sciences attended the inaugural Communicating Science Conference—Atlanta (ComSciCon-Atlanta), held on March 1-2, 2018, at Georgia Tech. Like the 46 other participants, they wanted to improve how to talk to nonscientists about their research.

The conference program comprised lectures, panel discussions, breakout sessions, and networking. Attendees listened, learned, and practiced what they learned on the spot. The three College of Sciences participants came away with practical tips that they can immediately apply to their graduate studies.

Audra Davidson is a second-year Ph.D. student majoring in applied physiology in the School of Biological Sciences. She came to Georgia Tech after obtaining a B.S. in Kinesiology at the University of Michigan, Ann Arbor. Her research, she says, “examines how the way we move interacts with the way we think, by investigating how healthy subjects and patients use their motor system during cognitive tasks such as reading words.”

Justin Lanier is a third-year Ph.D. student in the School of Mathematics. He received a B.A. in Liberal Arts at St. John’s College, in Annapolis, Maryland. Lanier studies the symmetries of surfaces and how they interact. “The questions I try to answer about surfaces,” he says, “are related to the fact that just a few different moves of a Rubik’s cube can combine to create every possible scramble.”

Justin Lawrence is a second-year Ph.D. student studying planetary sciences in the School of Earth and Atmospheric Sciences. He earned his B.S. in Environmental Geoscience from Boston College. Using the least number of words, Lawrence describes his research thus: “Life-finding Antarctic submersibles as practice for Europa.” One of Jupiter’s moons, ice-covered Europa is a target for scientists looking for life outside of Earth. Lawrence’s Ph.D. supervisor, Britney Schmidt, leads a team that is using the Antarctic to test probes that could pierce through Europa’s icy surface and search for life in the waters beneath.

In the following, Q&A Davidson, Lanier, and Lawrence reflect on their experiences at ComSciCon-Atlanta.

How did the conference meet your expectations?
Davidson: This conference wildly exceeded my expectations. From the experienced panelists and complex discussion topics, to the level of engagement and passion of every attendee, this conference was far better than I expected it to be. It’s amazing what can happen when you put a constant supply of caffeine and a lot of passionate scientists studying wildly different topics in the same room for two days!

Lanier: I was hoping to get a sense of publishing opportunities and to learn general-purpose tools and lenses for effective science communication. I also hoped to connect with other scientists interested in communicating with the public. The conference exceeded all these expectations.

Lawrence: I was hoping for more concrete activities and outcomes than what shorter meetings or seminars often deliver. ComSciCon-Atlanta proved to be just that. Organized by fellow graduate students in rigorous, quantitative fields, the workshops and panel discussions addressed useful, tangible strategies to improve our ability to communicate.

What did you find most useful, interesting, or engaging?
Lanier: Because almost all of the conferences I attend are focused on one discipline, it was exciting to interact with graduate students from a wide range of disciplines. I really enjoyed and appreciated the storytelling session – in which participants told a two-minute story to a partner, got feedback, and retold the now-improved story, to a second partner. It was useful to spend some time thinking about different ways to tell stories, because it’s easy to get in a rut and tell science stories in only certain kinds of ways

Lawrence: I particularly enjoyed the “Write-A-Thon.” We developed pieces on a scientific subject of our choice and went through peer and professional editing over the weeks leading to the conference. Working with an expert to refine a popular article I wrote greatly improved my work. I can apply the lessons I learned to most of the work I do.

Davidson: I loved hearing about other people’s work during the one-minute “Pop Talks.” Everyone’s research was different but we shared a passion for communicating our science to the public. Interacting with the other attendees helped me refine how I talk about my work. The real-time feedback during the “Pop Talks” – when the audience raised signs saying AWESOME or JARGON as the presenter spoke – is one helpful idea that I will take with me.

What practical lessons did learn?
Lawrence

• Tell stories. People respond to stories and personal experiences more than they do to facts.
• Scientists must communicate; it’s pointless to do the work if it cannot be effectively shared. Publicly funded researchers have an obligation to communicate their work. Communicating to audiences outside of one’s field shouldn’t be viewed as “dumbing things down’ or oversimplifying. Scientists must instead distill their work to the most essential, clear components.
• When writing for the public, do not follow the linear flow of academic writing. Lead with the subject and talk about implications without burying the readers in background.

Davidson

• Think creatively about how to think. The conference offered different ways to do this, including real-time feedback, improvisational techniques, and the use of humor. I found these tactics helpful and inspiring.
• Engage with scientists outside your field. This helps inspire creativity and collaboration and forces you to explain your work to someone who has no background in your field.
• Facts can’t counter stories, but other stories can. Scientists are frustrated when others are not swayed by facts. To engage with the public, you must listen to their stories. Explaining your science in a way that relates to their experience may influence their opinions better than just insisting on facts.

Lanier

• I realized the importance of explaining the nature and goals of pure mathematics research, not only to the public but also even to a scientifically trained audience.
• I got lots of great advice about structuring writing for a general audience, like leading with intriguing details and cutting quickly to the chase.
• I learned innovative and inspiring ways to share science with a wider audience, for example, the blog posts at Astrobites and Chembites.

ComSciCon is the brainchild of graduate students at Harvard University and Massachusetts Institute of Technology, who founded the annual workshop in 2013. Since then, ComSciCon has expanded beyond the annual meeting to a dozen local meetings throughout the country.

Laura Mast, a Ph.D. student in the Georgia Tech School of Civil and Environmental Engineering, led the inaugural ComSciCon-Atlanta. Her co-organizers were Carleenmae Sabusap, a graduate student in the University of Alabama, Birmingham; Anzar Abbas, a graduate student in Emory University; and Kellie Vinal, previously a postdoctoral researcher at Emory University and now a freelance science communicator. Vinal is the coordinator of the Atlanta Science Festival, the Atlanta producer of Story Collider, and scientist in residence at STE(A)M Truck.

This story by Monica Elliott originally appeared in the Winter 2017 Issue of Georgia Tech's Alumni Magazine.

Many of us grew up thinking of California as the epicenter of most earthquake activity in the United States. (It’s really Alaska.) But today, in the contiguous U.S., most of the major tremors—magnitude 3 or higher—actually occur in Oklahoma. And these tremors don’t appear to come from wholly natural causes.

“Most of this seismic activity is man-made or induced,” says Zhigang Peng, a professor of geophysics in Georgia Tech’s School of Earth and Atmospheric Sciences. 

Peng says that humankind has been proven to create earthquakes in three different ways: the construction of reservoirs or other surface-loading excavations; the direct extraction of natural resources, such as coal and oil from the earth; and the injection of fluids into the earth. 

However, Peng says a major misconception about induced earthquakes in the U.S. is that they’re primarily caused by the process of hydraulic fracturing, or fracking, to obtain oil and natural gas trapped in the earth. Fracking involves pumping high-pressure fluid into the ground with enough force to break open layers of rock so we can access those natural resources. 

Most of the earthquakes in Oklahoma and southern Kansas that researchers believe are induced are not directly caused by fracking itself, but instead by attempts to dispose of the wastewater at the end of the process by injecting it back into the ground, Peng says.

“The fracking process normally takes a short amount of time—maybe a few hours to a few days—to gain access to oil or natural gas,” Peng explains. “If everything works fine, you start to turn the fracking well into a production well. The production well will usually last for at least a few years if not longer, and during this process, a lot of extra things come out of the earth—most of them things you don’t want, like salt water. The easiest and cheapest way to dispose of this fluid is to inject it back into the earth.”

But to reach the type of rock formation that will consume it and to avoid contaminating aquifers, this wastewater must be injected back into the earth at a much deeper level than the fracking and production wells—which creates a seismic problem.

“The wastewater settles in a formation named Arbuckle that includes limestone and other sedimentary rocks with a lot of porous space because you want to have a layer that can suck a lot of water,” Peng says. “This layer sits right on top of the basement rock where most induced earthquakes occur.”

With the help of some of his students, Peng is studying high-rate injection wells in northwest Oklahoma where the U.S. Geological Survey forecasts the highest chance of earthquake damage in 2017. 

According to the Los Angeles Times, the Sooner state had only two to three earthquakes a year that reached 2.7 or greater from 1980 to 2000; but in 2015, there were 4,000 of that magnitude. That number decreased to 2,500 in 2016, which Peng postulates is likely due to tighter regulations and the decrease in oil prices leading to less fracking activity and resulting wastewater injection.

Among other things, Peng is studying why wastewater injection wells cause so many more earthquakes in Oklahoma than in any other part of the country. The factors he’s researching include injection rate, total volume injected and the presence of subsurface faults large enough to produce earthquakes that can be felt by man. 

INTO THE EARTHQUAKE HOT ZONE

In October, on a trip funded by the School of Earth and Atmospheric Sciences, Peng and some of the Ph.D. students in his earthquake physics course went to that hot zone in Oklahoma—places in and around the towns of Alva, Moreland and Fairview—and deployed some 20 seismic sensors to measure the activity. 

“We think we have pretty clear evidence saying wastewater injection and those induced earthquakes are related,” Peng says. “Fortunately, the state of Oklahoma also recognizes it’s a big problem. But there are still many open questions.”

Peng says the state is providing resources to help with their studies. Two staffers from the Oklahoma Geologic Survey and several University of Oklahoma students joined Peng and his students during the last deployment, as did two representatives from the company that provided the seismic sensors for the study, Seismic Source of Ponca City, Okla.

“The field deployment really highlighted the complexities of seismology and earthquake physics,” says Tech doctoral student Louisa Barama. “Over a few days, we set up stations in the same region but were surprised by the small differences each location had, from soil type and surrounding landscape and even picking station location.”  

Kai Hu, another PhD student, adds that their team also had a chance to communicate and interact with the local people who were well aware of all the seismic activity. “We let them know how the earthquake monitoring network can be used to advise and inform the government and oil companies to regulate their injection practices,” Hu says.

The largest earthquake registered in the region was a 5.8 in October 2016 near Pawnee, Okla., causing injury and damages. However, the vast majority of the tremors remain small, though still concerning.

According to Peng, there are two schools of thought on whether these induced earthquakes can cause larger, more dangerous earthquakes. Some believe it depends on the size of the perturbed area—if only a small, confined area is perturbed, only a small event could result, so the maximum size is limited. But the other argument is that once an event is triggered, no matter how small, that event could trigger an even larger event. 

“We’ve actually seen signs of this type of domino effect,” Peng says. “And in that case, once you start something, it’s not controlled by the region of perturbation, it’s controlled by tectonic loading. That means if the region is already stressed out and you trigger something and it goes into this domino effect you may trigger something much bigger than your initial perturbations.”

Peng hopes ultimately his research can help inform better ways for energy companies to access natural resources from the earth without inducing large, damaging earthquakes.

“You can’t just say to companies, ‘Don’t do it,’” Peng says. “We have to have energy, but we have to find a way to do it so that we don’t potentially cause problems. Nobody wants to trigger a damaging magnitude 7 or 8 earthquake. In that aspect, we’re all on the same page.” 

A RESERVOIR OF POSSIBILITIES IN CHINA

In addition to his work on earthquakes induced by wastewater injection, Zhigang Peng is conducting research on reservoir-induced earthquakes in the Sichuan Province of China where he grew up. He’s focused on the magnitude 7.9 Wenchuan earthquake that occurred in May 2008—the largest and most devastating earthquake in China in the past 40 years. 

A few years before the earthquake, the Zipingpu dam and reservoir was built within 10 kilometers of the epicenter of the event. There has been a long debate on whether the reservoir triggered the 2008 earthquake. Peng is currently working with scientists in China to re-examine the seismic data near the epicenter to find answers. 

Peng is presenting his research this month in New Orleans at the Annual American Geophysical Union Meeting, the largest conference for geophysicists in the world. If his findings establish a connection between the reservoir and the 2008 earthquake, it would be the largest confirmed human-induced earthquake on record. 

TREMOR TRIVIA

THE LARGEST RECORDED EARTHQUAKE in the United States was a magnitude 9.2 that struck Prince William Sound, Alaska, on March 28, 1964. The largest recorded earthquake in the world was a magnitude 9.5 (moment magnitude) in Chile on May 22, 1960. 

MAGNITUDE is the most common measure of an earthquake’s size. It is a measure of the size of the earthquake source based on the maximum motion recorded by a seismograph or seismometer. It is the same number no matter where you are or what the shaking feels like. 

THE RICHTER SCALE is no longer used by seismologists to measure magnitude, but it is still referenced often by the media. Other magnitude scales, extensions of Richter’s original idea, include body wave magnitude (Mb) and surface wave magnitude (Ms). Their range of validity is equivalent to the Richter magnitude. The more uniformly applicable extension of the magnitude scale is moment magnitude (Mw). For very large earthquakes, moment magnitude gives the most reliable estimate of earthquake size.

AN INCREASING NUMBER of earthquakes are being cataloged today not because there are more earthquakes, but because there are more seismic instruments able to record them.

THE NATIONAL EARTHQUAKE INFORMATION CENTER now locates approximately 20,000 earthquakes each year, or approximately 55 per day. 

ABOUT 16 MAJOR EARTHQUAKES, including 15 earthquakes in the magnitude 7 range and one earthquake magnitude 8.0 or greater, are expected to occur each year. 

Source: United States 
Geological Survey

Stephen Hawking spent his distinguished career studying the universe. It seems only fitting that the universe would have a say in the circumstances of the world-famous scientist’s death.

Hawking died on March 14 – Albert Einstein’s birthday. The day is also known as Pi Day (3.14 are the first three numbers of the famed mathematical constant.) Like Einstein, Hawking died at the age of 76.

A more profound connection between the two legendary geniuses is noted by City University of New York physics professor and author Michio Kaku in the New York Times obituary for Hawking: “Not since Albert Einstein has a scientist so captured the public imagination and endeared himself to tens of millions of people around the world,” Kaku says.

Hawking’s most impactful work in physics and cosmology involves the study of black holes, which are super-dense wells of gravity in space so powerful that not even light can escape them. It was Einstein who first predicted their existence, in the same 1916 research that posited his general theory of relativity. Hawking took Einstein’s foundational work and enhanced it with his own theory that black holes could dribble out energy in the form of heat before eventually disappearing – a theory now known as Hawking radiation.

Einstein predicted something else: the existence of gravitational waves, ripples in space and time caused when black holes collide. The Laser Interferometer Gravitational-Waves Observatory (LIGO) detected those waves for the first time in 2015. The LIGO Scientific Collaboration (LSC) supporting the effort, which led to the 2017 Nobel Prize in Physics, included the work of 17 Georgia Tech faculty and students.

School of Physics researchers share their thoughts on Hawking, what he meant to science, and how he inspired their research:

Paul Goldbart, Dean of the College of Sciences, Betsy Middleton and John Clark Sutherland Chair, and professor in the School of Physics 

“I was an undergraduate at Gonville and Caius College in the University of Cambridge, where Stephen Hawking was a Fellow of the College. My hall of residence for my first year was next door to his home on West Road. I would see him on many evenings, as we made our way the half-mile or so across the River Cam, and through the grounds of Kings College, to Caius for dinner.”

Pablo Laguna, LSC member, professor, and chair of the School of Physics

“Regarding his influence on my work, I would say it has been mostly inspirational. From the beginning of my career, Hawking’s work fueled my research to understand black hole phenomena where gravity has its strongest grip.”

Gongjie Li, assistant professor, School of Physics 

“Hawking's work is very influential to my research areas. Hawking made great contributions studying the perturbations of an expanding universe, and he estimated the dissipative effects of gravitational waves in 1966, which heat the nearby environment of the gravitational wave sources. This plays an important role in estimating the electromagnetic counterpart of gravitational waves, which can help localize their sources and solve puzzles of giant supermassive black holes. Based on Hawking’s work, we estimated the heating of stars and accretion disks, which could produce the electromagnetic counterpart of gravitational waves.

In addition to general relativity, Hawking was a leader in the search for extraterrestrial life. He served as a board member of the Breakthrough Starshot Initiative, which aims to visit our nearest neighboring star, Alpha Centauri. I was a member of the advisory committee, and now my students characterize the habitability of these extrasolar planets.”

Deirdre Shoemaker, LSC member, professor, and director of Georgia Tech’s Center for Relativistic Astrophysics

“Our understanding of black holes today has its foundation in the work of Stephen Hawking. While his most famous work was the discovery of black hole evaporation via the appropriately-named Hawking radiation, his work on black holes and singularity theories in the 1960s and 1970s informed generations of scientists, work that he continued throughout his life. The research I have had the good fortune to be involved with – predicting the gravitational radiation from the merger of two black holes and their subsequent detection by LIGO – relies on lessons from Hawking’s work, such as his black hole area theorem, and his work on the no-hair theorem. His work will live on and continue to influence future generations of physicists and astrophysicists.”

Ignacio Taboada, associate professor, School of Physics

“Stephen Hawking predicted thermal radiation by black holes. This results in black holes, very slowly, losing mass. As time goes on, the mass loss accelerates and the temperature of the black hole increases. The black hole eventually disappears in a flash of particles, including neutrinos. My doctoral student Pranav Dave is re-interpreting existing results by the IceCube neutrino observatory to search for ‘primordial black holes’ that would produce such a burst of neutrinos.”

Congratulations to faculty members who earned promotions and/or in academic year 2017-18.

Promotion from Assistant Professor to Associate Professor with Tenure

James Gumbart, School of Physics

Zaher Hani, School of Mathematics

Jennifer Hom, School of Mathematics

Patrick McGrath, School of Biological Sciences

Nepomuk Otte, School of Physics

Joseph Rabinoff, School of Mathematics

Martin Short, School of Mathematics

Matthew Torres, School of Biological Sciences

Kirsten Wickelgren, School of Mathematics

Ronghu Wu, School of Chemistry and Biochemistry

Promotion from Associate Professor to Professor

Flavio Fenton, School of Physics

Daniel Goldman, School of Physics

Plamen Iliev, School of Mathematics

Anton Leykin, School of Mathematics

Raquel Lieberman, School of Chemistry and Biochemistry

Zhiwu Lin, School of Mathematics

Francesca Storici, School of Biological Sciences

Mark Wheeler, School of Psychology

Tenure

Flavio Fenton, School of Physics

This story by Roger Slavens originally appeared in the Winter 2017 Issue of Georgia Tech's Alumni Magazine.

THOUGH VOLCANIC ACTIVITY of some form or another happens daily on our planet Earth, explosive eruptions of ash and pyroclastic matter—like those recently spewing from Bali’s Mount Agung—are a fairly rare occurrence. So it should be no surprise that Josef Dufek and his fellow volcanologists are excited by the opportunity to watch the fireworks and learn something new. An acclaimed expert on magma, fluid mechanics and the detonative dynamics of volcanoes, Dufek serves as professor and associate chair in the School of Earth and Atmospheric Sciences, where he teaches a number of courses and regularly leads students in field research. The Alumni Magazine thought it would be a blast to talk to Dufek about his work at Tech and find out if we’re all inevitably doomed to die under mounds of volcanic ash and lava.

1. WHAT'S YOUR SPECIFIC EXPERTISE WHEN IT COMES TO VOLCANO SCIENCE?

My training really is in fluid dynamics; in particular I’m trying to understand how fluids play a role in distributing energy—from the crust of the earth upwards. I look at the magma system below the ground and how it interacts with geothermal fluids and subsurface rocks. But probably the majority of my time is spent studying how volcanoes erupt, what causes them to erupt, and then—once they erupt—what the likely outcomes are. I’m most fascinated with explosive eruptions, like the one going on in Bali right now. 

2. HOW CAN YELLOW JACKETS PURSUE THE STUDY OF VOLCANOLOGY AT TECH?

We have an intro level class called Natural Hazards that’s fairly broad to start them off. But, more focused, we have a class called Physical Volcanology that really dives into the physics of volcanoes. It draws a lot of earth science majors but also many from engineering disciplines, most notably aeronautical engineers who are interested in how volcanic ash affects flight. We also teach a field course that’s called Field Methods in Volcanic Terrains that’s taught every year, and faculty and students travel to different volcanic sites every year. We often go to the Pacific Northwest, Northern Arizona and California, but we’ve also traveled farther afield to places like Mexico and Greece. 

3. IS THAT EVERYTHING?

Those are the big courses but there are many related offerings such as Geodynamics, that explores how large earth motions are dictated by energy in the earth, and an Intro to Geophysics class. I teach Fluid Mechanics as well. So there’s actually quite a breadth of things that touch upon volcanoes in one way or another. An undergraduate at Tech who is really interested in volcanoes would typically be an earth and atmospheric sciences major, and then could specialize in Geophysics.

4. WHAT'S INVOLVED WITH YOUR BIG RESEARCH PROJECT IN SOUTH AMERICA THIS COMING JANUARY?

Yes, in Chile. It’s a long-term project that involves a number of different U.S. institutions, but the main ones are Georgia Tech, Wisconsin and Cornell. It’s focused on one volcanic region called Laguna del Maule that first gained interest a few years ago because satellites found it evidence of sustained and dramatic uplift that might indicated volcanic activity. Our project aims to document that activity, and to try to understand better what will happen in the future in this region.

5. YOU MENTIONED THE EXPLOSIVE VOLCANO IN BALI, MOUNT AGUNG. WHAT'S GOING ON WITH THAT? WHY IS IT RECEIVING SO MUCH ATTENTION?

I’m not an expert on this particular volcano, but what’s happening is that magma is rising and volatile species—water, carbon dioxide, sulfur—are exsolving, creating a bubbly, low density magma. So you have this rapid change in density, and the change in buoyancy allows the magma to rise faster and faster, and then if it gets fast enough, it goes past the yield strength of the fluid, the magma, and it’ll break up or fragment. That’s when you get an explosive eruption that releases all that built-up pressure. 

6. IS THIS ERUPTION PARTICULARLY DANGEROUS?

Yes, because the material being released is extremely energetic. There are two main hazards to worry about. One, which is making the news now, is the volcanic ash that’s being expelled into the atmosphere. You can’t fly airplanes through it because the ash is rapidly quenched molten rock, which is really a glass. So if you have a plane up there in the ash, you’d be flying through glass shards, which you can guess would be bad for jet engines. The other hazard, which is why thousands of people are evacuating, is pyroclastic density currents. These are fast-moving, ground-hugging, deadly currents that are akin to a scalding hot avalanche. They’re turbulent, and they can move tens of meters per second—faster than you probably can drive down the roads there. It’s very hard to predict where these flows will go and they are much worse than effusive lava flows, which tend to move slower and more predictably. One other issue that becomes important in a place that gets a lot of rain, like Bali, is something called lahars, or mudflows. From this volcano, you’re ejecting tons and tons of really fine-grain material, and if you add a little water in, that kind of soup is a lahar. They are also very mobile and energetic and capable of causing much destruction in low-lying areas.

7. HOW COMMONPLACE ARE VOLCANOES LIKE THIS?

They’re pretty rare in terms of overall volcanic activity, but they get most of the news coverage. At any given moment, somewhere around the earth there’s something erupting, just not as grand as Mount Agung or in as populated a region.

8. WHAT'S ONE OF THE BIGGEST MISCONCEPTIONS ABOUT VOLCANOES?

Most people think of active volcanoes being these majestic mountains with colorful, relatively tranquil streams of lava flowing out of them, like the ones we have in Hawaii. But there’s a wide range of volcanic activity that doesn’t look or behave like that. The most dangerous ones are those like Agung that can explode violently and eject a lot of ash and create fast-moving, very destructive pyroclastic density currents.

9. WHAT'S THE UPSIDE OF VOLCANOES COMPARED TO OTHER NATURAL DISASTERS?

The thing that we do have an advantage over some other geophysical phenomena—say, earthquakes—is that we often have good warning signs that volcanoes will erupt. With earthquakes, scientists can make some long-term predictions about when faults are likely to fail, but the exact moments are pretty impossible to predict. Volcanoes generally give us more time to evacuate people and prepare for what’s about to come.

10. THERE'S A LOT OF TALK ABOUT SO-CALLED "SUPERVOLCANOES" AND THAT THEY COULD BE MANKIND'S DOOM. IS THAT TRUE?

“Supervolcano” is one of those terms with which volcanologists have a love-hate relationship. What people are talking about is something that’s massive in size and can produce a hundred to a thousand times the volcanic materials of, say, Mount St. Helens produced (about one cubic kilometer of volcanic material). We know that eruptions producing 100 to 1,000 cubic kilometers of material have happened in the past, just not in recorded human history. If you drive across the western United States, you almost certainly have driven by eruption deposits that document past volcanic activity on this scale—the evidence is there at Yellowstone National Park and all across southern Idaho in the calderas, many of which are now buried beneath potato fields. Researchers know that a so-called supervolcano will explode in the future, but there are no signs it will happen anytime soon, or even during our lifetimes. If Yellowstone did erupt on a massive scale right now, the volcanic ash would cool temperatures across the northern hemisphere and settle across the Midwestern U.S., probably destroying much of the country’s food production capabilities. There would be a domino effect globally, but it wouldn’t likely cause mass extinction or our ultimate doom. 
 

[Yes, HOIP quantum properties look extremely robust, and their physics are mystifying]

Some novel materials that sound too good to be true turn out to be true and good. An emergent class of semiconductors, which could affordably light up our future with nuanced colors emanating from lasers, lamps, and even window glass, could be the latest example.

These materials are very radiant, easy to process from solution, and energy-efficient. The nagging question of whether hybrid organic-inorganic perovskites (HOIPs) could really work just received a very affirmative answer in a new international study led by physical chemists at the Georgia Institute of Technology.

With significant effort, researchers succeeded in testing an existing HOIP and observed a “richness” of semiconducting physics created by what could be described as electrons dancing on chemical underpinnings that wobble like a funhouse floor in an earthquake. That bucks conventional wisdom because established semiconductors rely upon rigidly stable chemical foundations, that is to say, quieter molecular frameworks, to produce the desired quantum properties.

“We don’t know yet how it works to have these stable quantum properties in this intense molecular motion,” said first author Felix Thouin, a graduate research assistant at Georgia Tech. “It defies physics models we have to try to explain it. It’s like we need some new physics.”

Quantum properties surprise

Their gyrating jumbles have made HOIPs challenging to examine, but the team of researchers from a total of five research institutes in four countries succeeded in measuring a prototypical HOIP and found its quantum properties on par with those of established, molecularly rigid semiconductors, many of which are graphene-based.

“The properties were at least as good as in those materials and may be even better,” said Carlos Silva, a professor in Georgia Tech’s School of Chemistry and Biochemistry. Not all semiconductors also absorb and emit light well, but HOIPs do, making them optoelectronic and thus potentially useful in lasers, LEDs, other lighting applications, and also in photovoltaics.

The lack of molecular-level rigidity in HOIPs also plays into them being more flexibly produced and applied.

Silva co-led the study with physicist Ajay Ram Srimath Kandada. Their team published the results of their study on two-dimensional HOIPs on March 8, 2018, in the journal Physical Review Materials. Their research was funded by EU Horizon 2020, the Natural Sciences and Engineering Research Council of Canada, the Fond Québécois pour la Recherche, the Research Council of Canada, and the National Research Foundation of Singapore.

The ‘solution solution’

Commonly, semiconducting properties arise from static crystalline lattices of neatly interconnected atoms. In silicon, for example, which is used in most commercial solar cells, they are interconnected silicon atoms. The same principle applies to graphene-like semiconductors.

“These lattices are structurally not very complex,” Silva said. “They’re only one atom thin, and they have strict two-dimensional properties, so they’re much more rigid.”

“You forcefully limit these systems to two dimensions,” said Srimath Kandada, who is a Marie Curie International Fellow at Georgia Tech and the Italian Institute of Technology. “The atoms are arranged in infinitely expansive, flat sheets, and then these very interesting and desirable optoelectronic properties emerge.”

These proven materials impress. So, why pursue HOIPs, except to explore their baffling physics? Because they may be more practical in important ways.

“One of the compelling advantages is that they’re all made using low-temperature processing from solutions,” Silva said. “It takes much less energy to make them.”

By contrast, graphene-based materials are produced at high temperatures in small amounts that can be tedious to work with. “With this stuff (HOIPs), you can make big batches in solution and coat a whole window with it if you want to,” Silva said.

Funhouse in an earthquake

For all an HOIP’s wobbling, it’s also a very ordered lattice with its own kind of rigidity, though less limiting than in the customary two-dimensional materials.

“It’s not just a single layer,” Srimath Kandada said. “There is a very specific perovskite-like geometry.” Perovskite refers to the shape of an HOIPs crystal lattice, which is a layered scaffolding.

“The lattice self-assembles,” Srimath Kandada said, “and it does so in a three-dimensional stack made of layers of two-dimensional sheets. But HOIPs still preserve those desirable 2D quantum properties.”

Those sheets are held together by interspersed layers of another molecular structure that is a bit like a sheet of rubber bands. That makes the scaffolding wiggle like a funhouse floor.

“At room temperature, the molecules wiggle all over the place. That disrupts the lattice, which is where the electrons live. It’s really intense,” Silva said. “But surprisingly, the quantum properties are still really stable.”

Having quantum properties work at room temperature without requiring ultra-cooling is important for practical use as a semiconductor.

Going back to what HOIP stands for -- hybrid organic-inorganic perovskites – this is how the experimental material fit into the HOIP chemical class: It was a hybrid of inorganic layers of a lead iodide (the rigid part) separated by organic layers (the rubber band-like parts) of phenylethylammonium (chemical formula (PEA)2PbI4).

The lead in this prototypical material could be swapped out for a metal safer for humans to handle before the development of an applicable material.

Electron choreography

HOIPs are great semiconductors because their electrons do an acrobatic square dance.

Usually, electrons live in an orbit around the nucleus of an atom or are shared by atoms in a chemical bond. But HOIP chemical lattices, like all semiconductors, are configured to share electrons more broadly.

Energy levels in a system can free the electrons to run around and participate in things like the flow of electricity and heat. The orbits, which are then empty, are called electron holes, and they want the electrons back.

“The hole is thought of as a positive charge, and of course, the electron has a negative charge,” Silva said. “So, hole and electron attract each other.”

The electrons and holes race around each other like dance partners pairing up to what physicists call an “exciton.” Excitons act and look a lot like particles themselves, though they’re not really particles.

Hopping biexciton light

In semiconductors, millions of excitons are correlated, or choreographed, with each other, which makes for desirable properties, when an energy source like electricity or laser light is applied. Additionally, excitons can pair up to form biexcitons, boosting the semiconductor’s energetic properties.

“In this material, we found that the biexciton binding energies were high,” Silva said. “That’s why we want to put this into lasers because the energy you input ends up to 80 or 90 percent as biexcitons.”

Biexcitons bump up energetically to absorb input energy. Then they contract energetically and pump out light. That would work not only in lasers but also in LEDs or other surfaces using the optoelectronic material.

“You can adjust the chemistry (of HOIPs) to control the width between biexciton states, and that controls the wavelength of the light given off,” Silva said. “And the adjustment can be very fine to give you any wavelength of light.”

That translates into any color of light the heart desires.

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ALSO read this materials article: Turbocharging Fuel Cells with a Multifunctional NanoCatalyst

Coauthors of this paper were Stefanie Neutzner and Annamaria Petrozza from the Italian Institute of Technology (IIT); Daniele Cortecchia from IIT and Nanyang Technological University (NTU), Singapore; Cesare Soci from the Centre for Disruptive Photonic Technologies, Singapore; Teddy Salim and Yeng Ming Lam from NTU; and Vlad Dragomir and Richard Leonelli from the University of Montreal. The research was funded by: The EU Horizon 2020’s Curie Fellowship (project 705874); the EU 2020 Research and Innovation Program (Grant #643238 SYNCHRONICS); the Natural Sciences and Engineering Research Council of Canada and Fond Québécois pour la Recherche: Nature et Technologies; the Canadian Foundation for Innovation, the Natural Science and Engineering Research Council of Canada; and the National Research Foundation of Singapore (NRF-CRP14-2014-03). Any findings and opinions are those of the authors and not necessarily of the funding agencies.

A recent study conducted by researchers from Emory University and the Georgia Institute of Technology found that an infectious passenger with influenza or other droplet-transmitted respiratory infection will most likely not transmit infection to passengers seated farther away than two seats laterally and one row in front or back on an aircraft. The study was designed to assess rates and routes of possible infectious disease transmission during flights.
 
Co-researchers Vicki Hertzberg, Ph.D., professor at Emory University's Nell Hodgson Woodruff School of Nursing and Howard Weiss, Ph.D., professor in the School of Mathematics at the Georgia Institute of Technology, led tracking efforts in their FlyHealthy(TM) study, developing a model that combines estimated infectivity and patterns of contact among aircraft passengers and crew members to determine likelihood of infection.  
 
FlyHealthyTM team members were assigned to monitor specific areas of the passenger cabin, and made five round trips from the East to West Coast recording movements of passengers and crew. In addition, they collected air samples and obtained surface samples from areas most likely to harbor microbes. They leveraged the movement data to create thousands of simulated flight scenarios and possibilities for direct exposure to droplet-transmitted respiratory diseases. 
 
“Respiratory diseases are often spread within populations through close contact,” explained Hertzberg. “We wanted to determine the number and duration of social contacts between passengers and crew, but we could not use our regular tracking technology on an aircraft. With our trained observers, we were able to observe where and when contacts occurred on flights. This allows us to model how direct transmission might occur.”
 
“We now know a lot about how passengers move around on flights. For instance, around 40 percent of passengers never leave their seats, another 40 percent get up once during the flight, and 20 percent get up two or more times. Proximity to the aisle was also associated with movement. About 80 percent of passengers in aisle seats got up during flights, in comparison to 60 percent of passengers in middle seats and 40 percent in window seats. Passengers who leave their seats are up for an average of five minutes.”
 
Researchers also noted fomite transmission – exposure to viruses that remain on certain surfaces such as tray tables, seat belts and lavatory handles – as additional likely contributors to disease transmission. They provide public health recommendations to help prevent the spread of infectious disease.
 
“We found that direct disease transmission outside of the one-meter area of an infected passenger is unlikely,” explained Weiss. Respiratory infections can also be transmitted indirectly through contact with an infected surface. This could happen if a sick passenger coughs into their hand, and later touches a lavatory surface or overhead bin handle. “Passengers and flight crews can eliminate this risk of indirect transmission by exercising hand hygiene and keeping their hands away from their nose and eyes.”
 
The study, which was funded in partnership with aerospace leader Boeing, evaluated only the potential spread of infectious agents on an aircraft. Transmission could also occur at other points in a passenger’s journey, underscoring the need to maintain healthy habits, he added.
 
Complete findings of the study are available in the journal Proceedings of the National Academy of Sciences. 
 
CITATION: Vicki Stover Hertzberg and Howard Weiss (co-first authors), Lisa Elon, Wenpei Si, Sharon L. Norris, and The FlyHealthy Research Team, “Behaviors, movements, and transmission of droplet-mediated respiratory diseases during transcontinental airline flights,” (Proceedings of the National Academy of Sciences, 2018). http://www.pnas.org/content/early/2018/03/13/1711611115

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