Kimberly Yovel Short
Luis Alexandre Pereira
The College of Sciences has named Jennifer Hom, Takamitsu Ito, and Scott Moffat as the 2018 recipients of the Cullen-Peck Faculty Fellowship Awards in the College of Sciences. The awards recognize innovative research by faculty at the associate professor or advanced assistant professor level. The goal is to help recipients take their research programs in new directions.
The fellowships are made possible by a generous gift to the College of Sciences from alumni Frank H. Cullen (B.S. in Mathematics with Honors 1973, M.S. in Operations Research 1975, Ph.D. Engineering 1984) and Libby Peck (B.S. in Applied Mathematics 1975, M.S. in Industrial Engineering 1976). The alumni couple wish to recognize and support faculty development in the College of Sciences
“We continue to be grateful for the generosity of alumni who encourage our faculty to take intellectual risks in their research,” says College of Sciences Dean and Sutherland Chair Paul M. Goldbart. “The Cullen-Peck fellowships help ensure that our research is pushing the frontiers of knowledge. Congratulations to the latest Cullen-Peck fellows.”
Jennifer C. Hom is an associate professor in the School of Mathematics. The award recognizes her outstanding research in knot theory, which has led to fundamental contributions to the study of knots and development of powerful tools in topology.
Knots can be conceived as loops of strings with ends glued together. Their study is a beautiful subject, central to understanding low-dimensional space, as well as some modern trends in physics. Hom’s work centers on knots in three-dimensional space. She has enriched the field by introducing deep new ideas.
A much-studied question asks whether a knot can bound a disk in four-dimensional space in certain nice ways. Such knots were previously known. But Hom was able to find a huge new family of such knots, inspiring a flurry of activity in the use of Heegaard-Floer theory to study such objects.
The Heegard-Floer theory is a much-studied technique that revolutionized low-dimensional topology. Yet, Hom found new subtle features, which she formalized as the epsilon invariant. The epsilon invariant is a number associated to each knot. By using the properties of these numbers, Hom proved that an infinite number of knots could bound certain disks in four-dimensional space and not others.
Her work inspired leaders in the field, including the developers of Heegaard-Floer theory themselves, to pursue new avenues of research. Among other things, this work gives a new proof that in a sense there is more than one way to do calculus in four dimensions.
The epsilon invariant is now part of the Heegard-Floer theory; it is taught in graduate courses around the world; it is considered one of the top five spectacular advances in the past decade. A mark of top-notch mathematics is that it inspires other people and takes a life of its own. Hom’s epsilon invariant belongs to this category.
“It's a great honor to receive this award,” Hom says. “I look forward to using this fellowship to help develop new techniques for studying knots and low-dimensional spaces.”
Biogeochemical Cycling and Ocean Deoxygenation
Takamitsu “Taka” Ito is an associate professor in the School of Earth and Atmospheric Sciences. The Cullen-Peck award recognizes his outstanding research in biogeochemical cycling and ocean deoxygenation.
Ito uses models to better understand the interactions of physical, chemical, and biological processes that regulate the cycling of chemical elements in the ocean. He develops theories of the partitioning of dissolved gases between the ocean and the atmosphere. He is renowned for recent work on the distribution of dissolved oxygen in the subsurface ocean.
In the 2017 paper “The Upper Ocean Oxygen Trend: 1958-2015,” Ito analyzed historical, global datasets of dissolved oxygen. He found that the amount of dissolved oxygen in the water – an important measure of ocean health – has been declining for more than 20 years.
This paper garnered media attention for the implications of declining oxygen in the ocean: It could affect the habitat of marine organisms worldwide. It could lead to more frequent “hypoxic events,” which kill or displace populations of fish, crabs, and other organisms.
Furthermore, the analysis showed that ocean oxygen is falling more rapidly than anticipated from the rise in water temperature due to climate change.
Ito has also been exploring the previously under-appreciated role of polluted aerosols in altering ocean biogeochemistry. In a 2016 paper in Nature Geoscience, he and his collaborators showed that air pollution can deliver additional iron and reactive nitrogen to the ocean and affect oxygen levels.
The transport of highly insoluble iron to the ocean and its availability for biological productivity are not well understood. Ito’s modelling approach will help translate into new insights the oceanic iron data from the large observational program GEOTRACES. His research could reveal how iron cycling affects ocean productivity, carbon uptake, and oxygen concentrations over various time scales.
Cognitive Neuroscience of Aging
Scott Moffat is an associate professor in the School of Psychology. His selection as Cullen-Peck fellow is based on his outstanding research in the cognitive neuroscience of aging.
With aging comes cognitive decline, which affect mental faculties including memory and the ability to navigate. Moffat has embarked on research addressing metabolism and aging. In particular, he studies the role of diabetes in cognitive aging.
Peripheral insulin crosses the blood–brain barrier to modulate memory processes. Insulin resistance in the periphery goes with insulin resistance in the brain and memory impairment. The hope is to associate variations in peripheral insulin secretion and insulin sensitivity to cognitive and neural endpoints.
Meanwhile, type 2 diabetes is a public health crisis in the U.S. and many developed countries. The disease is a risk factor for other serious health conditions, such as brain and cognitive dysfunction, as well as Alzheimer’s disease. Using functional magnetic resonance imaging, Moffat is examining the association of glucose and insulin metabolism with cognitive and brain function.
The research is still in its early days, but already Moffat and his colleagues are realizing remarkable results. For example, they’ve found that individuals with higher fasting glucose levels or insulin insensitivity – even within the non-diabetes range – have poorer performance in episodic and working memories. They also have thinner gray matter in key prefrontal cortical areas.
The implications for prediabetes are profound. Prediabetes is prevalent among adults; the National Center for Chronic Disease Prevention reports that majority of all adults older than 65 have prediabetes. Discovering the impact of prediabetes on cognition and cognitive decline could bring about interventions, pharmaceutical or otherwise.
Title: Sparsity, oracles and inference in high-dimensional statistics
Title: Sparsity, oracles and inference in high-dimensional statistics
A new national project, which includes the Georgia Institute of Technology, aims to convey the benefits of physics’ age-old intertwining with math upon biology, a science historically less connected with it. The National Science Foundation and the Simons Foundation have launched four centers to do this, funded with $40 million, one of which is headquartered at Georgia Tech and will receive a quarter of the funding.
Founding Members of the Organization include:
- Greg Bleckerman (GaTech SoM math)
- Christine Heitsch (GaTech SoM math)
- Natasha Jonoska (USF math)
- Julie Mitchell (UW-Madison math)
- Peter Bubenik (U. Florida math)
- Elena Dimitrova (Clemson math)
- Scott McKinley (Tulane math)
- Dan Goldman (GaTech physics)
- Francesca Storici (GaTech bio)
- Annalise Paaby (GaTech bio)
- Matt Torres (GaTech bio)
- Hang Lu (GaTech biochem)
- Melissa Kemp (GaTech bio-eng)
- Christine Payne (GaTech mech-eng)
This article was edited from a story originally posted 5/24/2018 by Ben Brumfield.
Galina Livshyts, an assistant professor in the School of Mathematics, has received one of the highly competitive early-career grants from the National Science Foundation Faculty Early Career Development (CAREER) program.
NSF CAREER grants provide five years of funding to junior faculty. The award is a strong signal of recipients’ potential to serve as academic role models in research and education and to lead advances in the mission of their organization.
“My research is about geometry in two, three, and higher dimensions,” Livshyts says. The NSF CAREER grant enables her to explore the geometry of convex bodies in high dimensions.
A convex body is a geometric body having the property that any segment joining two of its points is entirely contained within it. Livshyts' research proposal aims to answer the following questions:
- What is the largest hyperplane section of a unit cube?
- How many translates of a slightly smaller copy of a convex body suffice to cover it?
- Can two different polygons have the same collection of normals and the same areas of triangles spanned by their sides?
- How large are the perimeters of convex sets with respect to isotropic log-concave measures?
“A lot of the geometric properties of convex bodies have important applications,” Livshyts says.
Suppose we have a million 10-inch-diameter ball-shaped items, and we need to pack them in an optimal way. What shape should we choose for the package? Some other questions in which the theory of convex bodies is used are directly related to the speed of certain algorithms.
NSF CAREER awards are unique in also requiring grant proposals to include an education component. Supporting junior researchers is the focus of Livshyts’ education component. During the term of the award, she will undertake several educational activities, including a research workshop for junior mathematicians, seminars for women in mathematics at all levels, and workshops for K-12 mathematics teachers.
“It is very important for a junior mathematician to be able to find just one other direction for their research, to create just one collaboration aside from their doctoral and postdoctoral work,” Livshyts says. She hopes her proposed five-day research workshop will give junior mathematicians – those in their final two years of their Ph.D. and those within five years after completing their Ph.D. – “an opportunity to expand their collaboration network and the circle of their interests early in their career.”
Livshysts has been organizing regular seminars for Women in Mathematics in Northern Georgia. In this activity she is joined by Yulia Babenko, an associate professor of mathematics at Kennesaw State University.
“Having a network of female researchers in Atlanta will bring more female participants to mathematics conferences,” Livshyts says. Mathematicians of all levels are invited to participate, and talks are intended for a general audience. “That will help junior participants expand their interests, as well as practice giving talks to a broad audience,” Livshyts says.
In spring 2018, Livshyts facilitated workshops at the Atlanta Intown Teachers’ Math Circles. Intended for K-12 mathematics teachers, the workshops will focus on nonstandard mathematics problems to increase participants’ mathematical knowledge and encourage creativity.
Livshyts is one of several School of Mathematics faculty members currently enjoying NSF CAREER grants.
“This award makes a great difference in my career,” Livshysts says. “It will allow me to hire a postdoc, as well as organize a series of workshops for junior researchers, aimed to help others early in their career.”