Steve Sclar, left, recently demonstrated on the Emory campus how he gathers indoor air quality data. (Emory Photo/Video) By Carol Clark
Steve Sclar traveled to Golog Tibetan Autonomous Prefecture in China last summer to research the indoor air quality of nomads, who burn yak dung in their stoves for warmth and to cook their food. His measurements showed high levels of fine particulate matter in the smoked-filled tents and homes of some of the nomads. But Sclar also caught a glimpse of how global pollutants from industrialization may be impacting the isolated realm of the Tibetan plateau.
"The Tibetans are noticing changes in their climate and they're worried about the effects," says Sclar, an MPH student in Rollins School of Public Health's Department of Environmental Health. "Their grassland is getting poorer in the summer months and they see the snow pack getting smaller on the holiest mountain range in the region, known as Amnye Machen.
"I asked one nomad, 'What happens if Amnye Machen loses all of its snow?' He told me, 'Then it's the end of the world.'"
Climate change "is the biggest environmental health problem we face," Sclar says, "and yet it is so hard to pin down. There's no one country or entity to blame, and there is no one field of study that has the solution. We need to figure out how to reconcile all this."
Climate@Emory is an initiative made up of more than 50 faculty and staff from 20 departments across the university. Its goal is to harness Emory's strengths to help it play a leading role in the global response to perhaps the most complicated and pressing problem of our time. Since its launch last fall, the initiative has worked to support, connect and expand Emory's climate-related scholarship, teaching and community engagement.
"It's really not possible to understand climate change from the standpoint of any one discipline," says Eri Saikawa, who is Sclar's adviser and one of the founders of Climate@Emory. She is an assistant professor at Rollins and in the Department of Environmental Sciences. "We want to connect the dots to improve the quality and impact of Emory's research and provide a platform for intellectual engagement on climate change."
"We're tied into plants in myriad and intricate ways," says biologist Roger Deal, who studies how plants build and adapt their bodies.
By Carol Clark
“I’ve always been really fascinated by plants, even from a young age,” says Emory biologist Roger Deal. “Their lives are so interesting, even though they are stuck where they are born.”
Deal's roots are in Columbia, South Carolina, where his father was a physician and his mother loved to garden.
“My first plants were zinnias,” he recalls. “I was about 10 and my mom and I went to the garden store where I picked out a packet of seeds. You have these little dry things that look like pieces of dust. All you have to do is put them in the ground and get them wet, and then you have a whole organism. I thought, ‘Wow, what an amazing life cycle! How does it work?’”
Roger Deal
Plants go back millions of years, when the Earth’s atmosphere contained very little oxygen. “Where did all that extra oxygen come from? It’s a byproduct of plants,” Deal says. “All the energy that we need to live also comes from plants. And they’re beautiful – they’re an important part of our aesthetic. We are basically tied into plants in myriad and intricate ways.”
As an undergraduate at the University of South Carolina, Deal worked in a lab that studied phytoremediation, or the process of using plants to clean up pollution. “A lot of plants are tolerant of heavy metals,” he explains. “I worked on a project that was exploring how to use Spartina, the grass you see growing along salt marshes on the coast, to suck mercury pollution up out of the soil.”
Deal became interested in how genes are controlled in plant development during his graduate school years at the University of Georgia.
In his lab at Emory, he’s continuing this focus on how plants build and adapt their bodies. By digging deep into the developmental biology and genetics of plant systems, he hopes to unearth secrets that could benefit both agriculture and human health.
“A big question in studying the genome of any organism is figuring out where all the genes are, and how you put all the parts together to build an organism,” he explains. “Humans have a parts list of about 30,000 different genes, for example, but only 2 percent of our genome is genes. The rest was once considered junk DNA, but we now know that it’s not junk.”
Watch a video of Roger Deal:
DNA is not just floating around by itself in the nucleus of a cell. It’s wrapped up in little globules of proteins called histones. By wrapping tightly around histones, a six-meter long strand of DNA can cram into a cell nucleus.
“This complex of histones and DNA is called chromatin,” Deal says. “The chromatin is used to turn genes on or off, which determines the function of a cell. So chromatin is part of the system that differentiates the cells when an embryo is growing. Chromatin is also involved in establishing and maintaining cell proliferation. If cell proliferation gets turned on inappropriately, the result can become a tumor.”
One of the model organisms Deal’s lab uses is Arabidopsis thaliana, a small flowering plant that is a member of the mustard family. “It’s just a lowly little weed that you’ve probably stepped on and not noticed,” Deal says of Arabidopsis. “It grows all over the northern hemisphere.”
The Arabidopsis genome is about one-twentieth the size of the human genome. “It’s sort of streamlined,” Deal says. “It has about the same number of genes as we do, but it has way less ‘intergenic’ DNA. So in terms of finding the regulatory parts, we have a lot less stuff to look at. When it comes to lab research, Arabidopsis is like the fruit fly of the plant world.”
Arabidopsis thaliana (NIH)
Arabidopsis plants begin their life as the fusion of a sperm and an egg: A single cell, which develops into an embryo inside of a seed. “This little embryo can sit there for decades,” Deal says. “But once it gets wet, the whole thing kicks into action. Suddenly, it starts growing, pops a root, develops leaves.”
At some point, the plant switches from vegetative growth to reproductive growth. “Something in the environment, the length of the day, the quality of light, tells these plants it’s time to stop making leaves and start making flowers,” Deal says. “A really important question is how this switch operates at the molecular level.”
A key part of the puzzle appears to be a histone protein called H2AZ, which is an important component of chromatin in plants, animals and fungi.
“The H2AZ gene is essential for life in animals,” Deal says. “If an embryo doesn’t have it, the embryo stops developing and dies. But an overproduction of an H2AZ molecule appears to drive the genesis of several types of cancer, including breast and prostate cancer.”
Plants, unlike laboratory rats, can survive without the H2AZ gene. “If you knock out the H2AZ gene in Arabidopsis plants they don’t die, it just messes them up,” Deal says. “The lack of H2AZ affects the leaf size, flowering time and their susceptibility to pathogens and other stresses.”
That makes Arabidopsis an easily accessible model to study this particular gene and its on-and-off switch. “We can mess with Arabidopsis in pretty extreme ways, removing this critical regulator of a process, and then study what happens at the molecular level,” Deal says. “We’re hoping that our research will help us understand something about the biology of cancer and the biology of animal and plant development all in one fell swoop.”
“Amorphous material is everywhere, it’s among the most common states of solid matter,” Burton says, “and yet, there’s a lot that we don’t understand about it.”
Crystalline material, by contrast, is relatively rare but well understood by physicists. Crystals have a structural order that makes them easier to conceptualize and define mathematically.
“Research into the thermodynamic behavior of crystals at ultra-low temperatures led to our understanding of how they conduct heat,” Burton says. “That’s one of the fundamental triumphs of quantum mechanics. It helped lay the foundation for a lot of important tools of the modern world, from computers to cell phones.”
Lacking the well-defined order of crystals, amorphous materials often behave in peculiar, unpredictable ways. Burton uses the example of a pile of sand at the bottom of an hourglass. “What seems stable enough can suddenly avalanche upon the addition of a few extra grains,” he says. “Or even a traffic jam: What determines the boundary between a flowing state and a rigid one? Our world is full of similar examples where systems exist in a region near marginal stability.”
A view inside the vacuum chamber, where colloidal particles are suspended in a flat disc, lit by the green light of a laser. Photo by Justin Burton.
Burton’s lab is creating model systems to simulate the dynamics of the microscopic granules of amorphous, glassy matter at ultra-low temperatures of below 1 degree Kelvin. That’s colder than the deepest reaches of space.
In a vacuum chamber, filled with argon gas, the lab conducts experiments. The chamber is filled with ionized argon gas. “It’s a plasma, or a gas that has had its electrons ripped away from its atoms,” Burton explains. “The electrons are constantly being ripped away and resembling.”
Colloidal particles, tiny as dust specks, are suspended in the plasma of the vacuum chamber, to stand-in for the molecules of an amorphous material. By altering the gas pressure inside the chamber, and varying the size of the particles, the lab members can study how the particles behave as they move between an excited, free-flowing state into a jammed, stable position.
They can also simulate how molecules in a stable position react to a disturbance. “We want to create a wave, like dropping a pebble into a still pond to make ripples, and study that dynamic,” Burton says. “That could help us understand, for instance, how sound moves through a glassy material.”
Burton’s lab will use another model, involving polymer hydrogel particles that expand or shrink in response to salt concentrations, to study Casimir forces, a special type of long-ranged force that can arise between objects in a highly fluctuating medium.
In addition to opening a window into the molecular motions common in glasses, the research could shed light on the connection between the dynamics and disorder in a broad range of physical systems, Burton says.
In parallel to his research effort, the CAREER award will also fund the creation of an after-school science club at an elementary school in Dekalb County. Burton and his graduate students will lead children in hands-on activities and experiments that give insights into basic principles of physics.
Image from cover of the NIH brochure "The BRAIN Initiative."
The European Commission has promised 1 billion euros for its Human Brain Project, which seeks to build a computer model of the human brain within the next decade. And U.S. federal agencies are expected to contribute several billion dollars to President Obama's BRAIN Initiative (Brain Research through Advancing Innovative Neurotechnologies).
Articles in the current issue of the American Journal of Bioethics Neuroscience (AJOBN) represent the scope of ongoing neuroethical inquiry, from criteria for human trials to study Parkinson’s disease to the use of prescription stimulants to enhance motivation.
“The study of neuroscience, unlike many other scientific disciplines, resonates with the notion of who we think we are,” write the authors of an editorial in the issue. “Therefore, the ethical questions often move beyond research and professional ethics into the complex terrain of evaluating societal implications. This will impact how we educate our burgeoning neuroscientists.”
“Ultimately, the success or failure of the human brain projects will be measured only partly by the extent to which they accomplish the goal of mapping the human connectome,’ the editorial authors conclude. “If the goal of the projects is to understand the human brain, the goal of neuroethics is to help understand and explain what understanding the brain would really mean.”
The AJOBN is the official publication of the International Neuroethics Society and many of its editors are housed in Emory’s Center for Ethics.
Emory chemist Doug Mulford gets kids fired up for science during a demonstration at last year's Atlanta Science Festival. Emory Photo/Video
By Carol Clark
Start with a beaker as big as metro Atlanta. Add scientists, artists, music, dance, robots, games, movies, lab tours and chances to try new technology and conduct fun experiments. Throw in some liquid nitrogen ice cream, giant soap bubbles and Tibetan momos. Now mix with hundreds of enthusiastic volunteers and thousands of curious people of all ages. Finally, jump in yourself.
The Atlanta Science Festival is back, March 21-28, with its ever-evolving formula for fascination and fun. The eight-day celebration of local science and technology encompasses more than 120 events at 70 venues throughout Atlanta, including many on the Emory campus. The festival culminates in the Exploration Expo at Centennial Park on Saturday, March 28.
“We want to help our community become proud of the resources, research and discoveries happening here, and all the opportunities for careers,” says Jordan Rose, co-director of the festival and associate director of the Emory College Center for Science Education. “The more we can connect people to local scientists and their innovations, the more people can get excited about science in general.”
Last year, 30,000 people attended the week-long inaugural Atlanta Science Festival, including 16,000 who came to the Exploration Expo, which was chaired by Emory chemist Monya Ruffin.
"It’s hard to predict attendance this year for all of the events over eight days, but we’re expecting at least 20,000 people for the Expo alone,” Rose says. “It’s going to be a busy day at the park.”
About 20 booths at the Expo will feature Emory science faculty and students. ChEmory, for example — the outreach group made up of Emory chemistry undergraduates — will return with its popular dance pit. Kids can kick their shoes off and experience moving to music through a non-Newtonian fluid.
