June 7, 2018 | Atlanta, GA

What does flying in a commercial airliner have in common with working at the office or relaxing at home? 

According to a new study, the answer is the microbiome – the community of bacteria found in homes, offices and aircraft cabins. Believed to be the first to comprehensively assess the microbiome of aircraft, the study found that the bacterial communities accompanying airline passengers at 30,000 feet have much in common with the bacterial communities surrounding people in their homes and offices.

Using advanced sequencing technology, researchers from the Georgia Institute of Technology and Emory University studied the bacteria found on three components of an airliner cabin that are commonly touched by passengers: tray tables, seat belt buckles and the handles of lavatory doors. They swabbed those items before and after ten transcontinental flights and also sampled air in the rear of the cabin during flight. 

What they found was surprisingly unexciting.

“Airline passengers should not be frightened by sensational stories about germs on a plane,” said Vicki Stover Hertzberg, a professor in Emory University’s Nell Hodgson Woodruff School of Nursing and a co-author of the study. “They should recognize that microbes are everywhere and that an airplane is no better and no worse than an office building, a subway car, home or a classroom. These environments all have microbiomes that look like places occupied by people.”

The results of the FlyHealthy™ study were reported June 6, 2018, in the journal Microbial Ecology. In March, the researchers reported on a separate part of the study that examined potential routes for transmitting certain respiratory viruses – such as the flu – on commercial flights.

Given the unusual nature of an aircraft cabin, the researchers hadn’t known what to expect from their microbiome study. On transcontinental flights, passengers spend four or five hours in close proximity breathing a very dry mix of outdoor air and recycled cabin air that has been passed through special filters, similar to those found in operating rooms. 

“There were reasons to believe that the communities of bacteria in an aircraft cabin might be different from those in other parts of the built environment, so it surprised me that what we found was very similar to what other researchers have found in homes and offices,” said Howard Weiss, a professor in Georgia Tech’s School of Mathematics and the study’s corresponding author. “What we found was bacterial communities that were mostly derived from human skin, the human mouth – and some environmental bacteria.”

The sampling found significant variations from flight to flight, which is consistent with the differences other researchers have found among the cars of passenger trains, Weiss noted. Each aircraft seemed to have its own microbiome, but the researchers did not detect statistically significant differences between preflight and post-flight conditions on the flights studied.

“We identified a core airplane microbiome – the genera that were present in every sample we studied,” Weiss added. The core microbiome included genera Propionibacterium, Burkholderia, Staphylococcus, and Strepococcus (oralis).

Though the study revealed bacteria common to other parts of the built environment, Weiss still suggests travelers exercise reasonable caution. “I carry a bottle of hand sanitizer in my computer bag whenever I travel,” said Weiss. “It’s a good practice to wash or sanitize your hands, avoid touching your face, and get a flu shot ever year.”

This new information on the aircraft microbiome provides a baseline for further study, and could lead to improved techniques for maintaining healthy aircraft.

“The finding that airplanes have their own unique microbiome should not be totally surprising since we have been exploring the unique microbiome of everything from humans to spacecraft to salt ponds in Australia. The study does have important implications for industrial cleaning and sterilization standards for airplanes,” said Christopher Dupont, another co-author and an associate professor in the Microbial and Environmental Genomics Department at the J. Craig Venter Institute, which provided bioinformatics analysis of the study’s data.

The 229 samples obtained from the aircraft cabin testing were subjected to 16S rRNA sequencing, which was done at the HudsonAlpha Institute for Biotechnology in Huntsville, Alabama. The small amount of genetic material captured on the swabs and air sampling limited the level of detail the testing could provide to identifying genera of bacteria, Weiss said. The extensive bioinformatics, or sequence analysis, was carried out at the J. Craig Venter Institute in La Jolla, Calif.  

In the March 19 issue of the journal Proceedings of the National Academy of Sciences, the researchers reported on the results of another component of the FlyHealthy™ study that looked at potential transmission of respiratory viruses on aircraft. They 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. 

That portion of the study was designed to assess rates and routes of possible infectious disease transmission during flights, using a model that combines estimated infectivity and patterns of contact among aircraft passengers and crew members to determine likelihood of infection. FlyHealthy™ team members were assigned to monitor specific areas of the passenger cabin, developing information about contacts between passengers as they moved around.

Among next steps, the researchers would like to study the microbiome of airport areas, especially the departure lounges where passengers congregate before boarding. They would also like to study long-haul international flights in which passengers spend more time together – and are more likely to move about the cabin.

In addition to those already mentioned, the paper’s authors include Josh L. Espinoza and Karen Nelson of the J. Craig Venter Institute, Shawn Levy of the HudsonAlpha Institute for Biotechnology, and Sharon Norris of The Boeing Company.

This work was supported by contract 2001-041-1 between the Georgia Institute of Technology and The Boeing Company.

CITATION: Howard Weiss, et al., “The Airplane Cabin Microbiome,” (Microbial Ecology, 2018).  https://link.springer.com/article/10.1007/s00248-018-1191-3

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June 11, 2018 | Atlanta, GA

Associate School of Math Professor Jen Hom has been selected to receive a 2018 College of Sciences Cullen-Peck Scholar Award in recognition of her innovative research. Additional information on the award and in the citation is included below.  Jen is in good company with past recipients of this award, including Anton Leykin and Sung Ha Kang.

Cullen-Peck Scholar Awards: These awards recognize innovative research led by College of Sciences faculty who are at the associate professor or advanced assistant professor level. They are made possible through the generosity of alumni couple Frank Cullen (BS ’73 Math, MS ’76 ISyE, PhD ’84 ISyE) and Libby Peck (BS ’75 Math, MS ’76 ISyE), who wish to recognize and support faculty development within the College of Sciences.

Associate Professor Jennifer Hom (School of Mathematics): Jen has made fundamental contributions to the study of knots and the development of powerful new tools in topology, in particular innovative contributions to Heegaard-Floer theory. She is a highly creative mathematician who has solved long standing problems and introduced influential new ideas to the community, clearly contributing to Georgia Tech’s role as a US center for geometry and topology.

June 14, 2018 | Atlanta, GA

All over campus this summer, undergraduates are working with Georgia Tech researchers. Many programs are in full swing, modeled after the Research Experiences for Undergraduates (REU) program of the National Science Foundation (NSF).

The School of Mathematics likely takes the prize for the most number of programs by one unit: six.  By summer’s end, seven professors, three postdoctoral mentors, and five graduate students would have worked with 13 undergraduate students. The undergrads come from 11 colleges and universities, including three in Georgia: Agnes Scott College, Georgia Tech, and Spelman College.   

Funding comes from various NSF grants and the School of Mathematics. 

Why REUs

REU programs play the same role for research careers as high school sports do for the NFL and NBA, says School of Mathematics Professor Igor Belegradek. Talent presenting early must be nurtured and honed as soon as possible.

Belegradek organized the summer 2018 REUs with colleague Dan Margalit.

“We have a rich history of undergraduate research in mathematics, as you can see on our website,” Margalit says. “It’s a testament to our faculty’s intellectual creativity and dedication to undergraduate education.”

REUs have important benefits for students, faculty mentors, and the School of Mathematics.

They help bring students to the School’s graduate program. They enable members of underrepresented minorities get advanced training and positive experiences in math research.

REUs advance the research of faculty. “We give students problems that we are genuinely interested in,” Margalit. “They are integral to our research programs.” 

REUs also provide mentoring experience to early-career researchers – graduate students and postdoctoral researchers – serving as mentors. “The training is valuable for them,” Margalit says. “It helps give them confidence in their own research and make them marketable for job searches.”

Undergraduates’ ability to penetrate difficult problems inspires Margalit. “They are fearless and creative, trying approaches that I might not think of,” he says. “They might not understand every bit of background that goes into a problem. But we, as mentors, can airlift them to the front lines of the problem.”

Undergraduates "are fearless and creative, trying approaches that I might not think of. They might not understand every bit of background that goes into a problem. But we, as mentors, can airlift them to the front lines of the problem." Dan Margalit

Cutting-Edge Research

Although Margalit’s program – on mapping class groups – has six students, other REUs have only one or two students. Three began as early as May 21; one will last until Aug. 10. In sessions lasting from five to seven weeks, the mathematicians will tackle problems in various cutting-edge areas.

Following are two examples of problems Georgia Tech undergrads will be confronting.

  • Shadow Problem

Mohammad Ghomi has been working with Georgia Tech undergraduate Alexander Avery since May 21. From Ghomi’s list of open problems in geometry of curves and surfaces, Avery chose the “shadow problem” for surfaces.

Ghomi explains the problem thus: Consider a convex object, such as a ball or an egg. When such object is illuminated from any direction, the dark region of the surface, called the shadow, forms a connected set. In other words, the shadow is one piece.

What about the converse? Suppose the shape of a surface is unknown. And suppose the shadow is one piece when illuminated from any direction. Does it follow that the surface is convex?

Ghomi published a solution in Annals of Mathematics in 2002. The answer is yes for surfaces similar to balls and eggs. But not for other shapes, such as donuts.

“Alex is working on the discrete version of this problem,” Ghomi says. Avery is looking at surfaces that are not smooth – like balls and eggs – but instead are composed of polygons glued along their edges. “Alex has been making good progress. It looks like the polyhedral case will be similar to the smooth case.”  

  • Legendrian Knots

“In mathematics, knots can be thought of as pieces of string which are tied up and then have the ends glued together,” says Caitlin Leverson, one of the postdoctoral mentors. “An interesting problem is to decide whether two knots are the same or different.”

Legendrian knots satisfy additional conditions. Two Legendrian knots may look very different, but be the same. Invariants are methods of assigning values to knots so that two knots are assigned the same value if they are the same. 

From May 29 to Aug. 10, Leverson will be working with two Georgia Tech fourth-year mathematics majors: DeVon Ingram and Hunter Vallejos. Their goal is to find Legendrian knots that are different yet are assigned the same value by the invariant.

 Since his second year as a mathematics major, Ingram has done research with different professors, including outside the School of Mathematics. For example, he worked on computational complexity theory with Lance Fortnow, professor and chair, School of Computer Science.

Ingram appreciates the beauty of differential geometry and its relation to physics. He sees correspondence between knot invariants and topological quantum field theories. Because of these interests, “I am naturally drawn to a knot theory problem,” he says. 

Vallejos has been doing research since he was in Oak Ridge High School, in Oak Ridge, Tennessee, just 10 miles from Oak Ridge National Laboratory (ORNL). One outcome of his stints at ORNL is a 2017 paper in the Journal of Economic Interaction and Coordination, of which Vallejos was first author.

“I love when algebra, geometry, and topology intersect,” Vallejos says. “Legendrian knot theory blends these three distinct fields, which makes it a rich subject to study.”

Visiting Students

Several of the undergraduate researchers this summer come from outside Georgia Tech. Among them are Johannes Hosle and Andrew Sack.

Johannes Hosle hails from South Bend, Indiana. He is a third-year math major in the University of California, Los Angeles. His major interests are analysis and number theory. Starting on June 18, he will work with Galyna Livshyts and Michael Lacey.

“The general area of my problem will be in harmonic analysis in convex geometry,” Hosle says. “My interest stems from a general interest in analysis. The types of problems in this branch of mathematics seem to resonate most with me.”

Andrew Sack hails from Gainesville, Florida. He is a fourth-year mathematics major from the University of Florida. A published author in the International Journal of Mathematics and Computer Science, he is one of two students who have been working with John Etnyre and Sudipta Kolay since May 30.  

Etnyre also studies how to tell knots apart. In his approach, a knot is represented by a diagram of a loop on a paper. The loop can cross over itself as many times. “But each time the loop crosses over itself, you have to specify which of the two strands is on top of the other,” Etnyre says.

A coloring of a knot is a labeling of the strands by a method that has consistency at the crossings. The coloring can tell two knots apart. “The work is related to research trying to figure out how three-dimensional spaces can be put inside a five-dimensional space.”

 “I’m interested in this research because, after taking two years of topology, I find it fascinating,” Sack says. “Previous research I’ve done centered on graph coloring. I can use some of the intuition I built around graph coloring to help better understand knot coloring.”

This story was modified from a story appearing June 14th by Maureen Rohi.

July 5, 2018 | Atlanta, GA

The National Science Foundation (NSF) has awarded a Research Training Groups (RTG) grant to the Georgia Tech Geometry and Topology (GTGT) group. GTGT will use the $2.1 million grant over five years to train undergraduates, graduate students, and postdoctoral fellows. The GTGT project supports NSF’s long-range goal to increase the number of U.S. citizens, nationals, and permanent residents pursuing careers in mathematics.

School of Mathematics faculty members Igor Belegradek, John Etnyre, Stavros Garoufalidis, Mohammad Ghomi, Jennifer Hom, Thang Le, Dan Margalit, and Kirsten Wickelgren make up GTGT and are co-principal investigators of the grant.

Why Study Topology and Geometry
Etnyre answers this question. He explains:

“Topology is the study of spaces. They can be the space we live in or configurations of mechanical systems. Mathematicians also consider spaces of solutions to algebraic equations and partial differential equations, as well as even more abstract space.

“More specifically topology is the study of spaces where some notion of continuity makes sense. What are these spaces? How can we distinguish one space from another? What interesting properties do specific spaces have? These are the basics questions in topology, whose language pervades much of mathematics, science, and engineering.

“Geometry is, loosely speaking, the study of some kind of structure on a space. Riemannian geometry involves spaces on which you can measure lengths of vectors and the angles in between. Symplectic geometry allows one to study dynamical systems akin to classical mechanics on a space.

“Topology and geometry underlie a great deal of science and engineering. Whether trying to understand general relativity and the structure of the universe, design robust sensor networks, unravel DNA recombination, develop string theory, or countless other endeavors, the underlying language and ideas are likely to be that of geometry and topology.”

“Topology and geometry underlie a great deal of science and engineering. Whether trying to understand general relativity and the structure of the universe, design robust sensor networks, unravel DNA recombination, develop string theory, or countless other endeavors, the underlying language and ideas are likely to be that of geometry and topology.”

Expected Outcomes 
Over its five-year run, the grant will enable the training of 60 undergraduate students, 22 graduate students, and 14 postdoctoral fellows. Supplementary funding from the College of Sciences will ensure three years of support for all postdoctoral fellows.

Etnyre says GTGT will leverage its access to Georgia Tech’s engineering programs to spark collaborations between engineers and mathematicians. Similarly, GTGT will use its proximity to institutions serving groups underrepresented in mathematics to help increase the representation of minorities and women in advanced mathematics.

Ultimately, Etnyre says, “we aim to develop students and postdoctoral fellows who are well-rounded scholars, accomplished teachers, and valuable members of the mathematics community.”

Areas of Expertise
The GTGT group is strong in various fields:

  • Algebraic Topology: Kirsten Wickelgren
  • Contact and Symplectic Topology: John Etnyre
  • Geometric Group Theory: Igor Belegradek and Dan Margalit
  • Global Riemannian and Differential Geometry: Igor Belegradek, John Etnyre, and Mohammad Ghomi
  • Heegard-Floer Theory: John Etnyre and Jennifer Hom
  • Low-Dimensional Topology: John Etnyre, Stavros Garoufalidis, Jennifer Hom, Thang Le, and Dan Margalit
  • Quantum Topology: Stavros Garoufalidis and Thang Le
  • Riemannian Geometry of Submaniforlds: Mohammad Ghomi

All these areas would benefit from the grant.

“We aim to develop students and postdoctoral fellows who are well-rounded scholars, accomplished teachers, and valuable members of the mathematics community.”

Grant-Enabled Activities
The grant enables the GTGT group to embark on several major activities:

  • Expand the group by supporting graduate and postdoctoral fellowships
  • Enhance educational opportunities for all students through new courses, expanded seminars and REU (Research Experiences for Undergraduates) opportunities, and a direct-reading program for undergraduates
  • Firmly establish the annual Georgia Tech Topology Conference and the biennial Topology Students Workshop, continue the Southeastern Undergraduate Mathematics Workshop, and initiate the Georgia Tech Topology Summer School
  • Strengthen professional development components of graduate and postdoctoral training
  • Increase interaction with colleges and universities serving groups that are underrepresented in mathematics and expand outreach to precollege students
  • Create a website to serve as repository of resources

JungHwan Park

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Shaojun Ma

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Skye Binegar

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Nicholas Barvinok

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Michael Wigal

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Michail Sarantis

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