Showing posts with label Chemistry. Show all posts
Showing posts with label Chemistry. Show all posts

Wednesday, June 4, 2014

Crushing myths, pinning down facts about insects

What does an adult luna moth eat? Nothing, because it has no mouth. These short-lived insects are among those that students collected and are displaying in the halls of the biology department, along with posters on the interesting characteristics of 12 different insect orders.

By Carol Clark

“The first day, I flinched,” says Emily Fu of the Emory Maymester course “Insect Biology.” She recalls feeling queasy as the professor, Jaap de Roode, showed a series of close-up images of creepy crawlers.

“I was seriously considering dropping the class. But as we learned more about them, and how awesome they are, I actually started to appreciate them,” says Fu, a junior majoring in biology and psychology. “Insects are really complex and much smarter than most people realize.”

Fu and the 11 other undergraduates in the class created a buzz in the biology department recently when they unveiled dozens of pinned and mounted specimens they collected during four field trips. The students also displayed scientific posters they created for insect orders that particularly intrigued them, wowing guests at the reception with their newfound knowledge.

Add crunch to your lunch: As the human population burgeons to 9 billion, insects are looking like the future of food, according to a recent U.N.report.

The female large blue butterfly, for instance, has evolved to hang out around ant nests. The butterfly lays eggs that hatch into caterpillars that look like, and smell like, an ant larva. “Some ants are tricked into taking care of the butterfly larvae,” Fu says, adding that the ants will even fight to protect the butterfly babies from parasitic wasps that try to lay their eggs inside them. When the ants attack one of these egg-laying wasps, however, the wasp releases a pheromone that drives the ants into a frenzy. The ants end up attacking and killing each other instead.

“A lot of crazy stuff is going on in the insect world,” muses Tufayel Ahmed, a senior majoring in biology.

A snack table was laid out with nacho-cheese Doritos, mealworm beetle larvae seasoned with Mexican spices and salt-and-vinegar crickets.

“The crickets are a bit stale,” warns Wilson Hunt, a junior majoring in biology whose poster was entitled “Orthoptera as Food.” While they may not be fresh, he adds encouragingly, they contain 60 percent protein, versus only 18 percent in a burger.
Alycia Patton eyes a specimen.

In addition to new culinary experiences, the reception gave guests a leg-up on vocabulary.

“Every bug is an insect, but not every insect is a bug,” says Alycia Patton, a senior majoring in biology. She explains that the forewings of true bugs, one branch of an evolutionary tree, are thick and leathery where they attach near the body and thin and membranous near the tips. Another defining feature: Mouth parts that can pierce the tissue of a plant or another insect.

Patton traces her love of entomology back to her childhood. She enjoys finding unexpected beauty in the tiniest of insects, like the vivid colors of the candy-striped leafhopper.

But she reserves her highest praise for the homely mole cricket. “Its front legs have little scoops on them so that it can dig tunnels,” Patton says. “The males build the tunnels in a way that amplifies its mating calls. It creates its own sound system.”

Maura Sare, a junior majoring in biology and environmental sciences, overcame an aversion to touching insects during the class field trips. “Most insects aren’t going to bite you,” she says, and many have evolved much more interesting ways of protecting themselves.

Take the stick insect. “If a predator grabs one of its legs, it can just detach it and get away,” Sare says. And they have fantastic camouflage, she adds. “We actually don’t have any examples of stick insects here today. We couldn’t find any.”

Stone Mountain was the site of one of the class collecting trips.

Alexander Heaven appreciates saturniids, including the large, lime-green luna moth, “because they’re pretty,” and because that beauty is ephemeral. “An adult luna moth doesn’t have a mouth, so it can’t eat,” Heaven says. “When they emerge from the cocoon, they have about five days to find a mate before they just fade away.”

Heaven, a sophomore majoring in environmental sciences, is also a big fan of the praying mantis. “During mating, the female mantis will cannibalize the male,” he says. “She’ll turn around and rip his face off. That’s awesome. They’re just really great predators, the best at what they do.”

Biology major Kevin Flood points to a pinned example of another great predator, the robber fly. It looks like a bee, but that’s a trick of mimicry designed to lure real bees near so the robber fly can eat them, Flood says. “See that needle-like thing coming out of its mouth? It wraps its legs around the bee, sticks the needle in, liquefies the bee’s insides and then sucks them up like a straw.”

As if bees didn’t have enough to worry about.

Head first: Biology post-doc Daniel Kueh dropped by the reception and learned that crickets are like potato chips. It's hard to stop at just one.

Pesticides and pathogens have been linked to a rise in colony collapse disorder, which is causing mass disappearances in honeybees. The issue is under intensive study due the importance of these insects, says Nikki Mehran, a senior majoring in biology.

“I was surprised to learn how many food crops that honeybees pollinate,” she says. “One-third of our diet would be missing if all bees suddenly disappeared.”

Mehran says the fieldwork was her favorite part of the class. “We got to go to Stone Mountain and I’d never been there,” she says. “After coming out of finals and being trapped inside, it felt good to get out in nature. I had a great time.”

The “Insect Biology” class was launched this spring by Jaap de Roode, an evolutionary biologist whose lab is one of only a handful in the world focused on monarch butterflies. “More than half of all animal species are insects, and they are extremely important for many things, from health to ecology,” he says.

De Roode hopes to develop the class to include a field trip to the Ecuadorian Amazon. Meanwhile, he says, the insects that the students collected and the posters they made will be on display near introductory biology classes “so other students can learn and be inspired by this work.”

Credits: Luna moth by Shawn Hanrahan; insect snacks and Daniel Hueh photos by Carol Clark; Alycia Patton photo by Malia Escobar; field trip photo by Jaap de Roode.

Related:
Lack of respect for insects bugs a biologist
Monarch butterflies use drugs
What aphids can teach us about immunity 

Wednesday, May 21, 2014

Armelagos leaves rich legacy of bio-archeology, teaching, friendship

George Armelagos at his Georgia beach house with his cat, Miles.

By Carol Clark

George Armelagos, professor of anthropology at Emory University and one of the founders and leaders of the field of paleopathology, died May 15, just six days after being diagnosed with pancreatic cancer. 

Armelagos, who was 77, was the son of Greek immigrants and grew up outside of Detroit. He came to Emory in 1993 as the Goodrich C. White Professor of Anthropology, and helped solidify the University’s reputation as a national leader in the bio-cultural approach to anthropology. He continued to teach, mentor and publish until his death.

He is survived by his brothers, Nick and James Armelagos of Detroit, as well as numerous friends, former students and colleagues throughout the world.

“George was a joyous man who loved life, people and his work,” said Peter Brown, Emory professor of anthropology and global health. “He taught all of us many things – humility, generosity, curiosity, hard work, and the critical importance of social relationships.”

He was also a prolific scientist, leaving behind 13 books and monographs and more than 250 journal articles.

“I enjoy what I’m doing,” Armelagos said last year of his lengthy career. “It’s energizing. How could I get tired of it?”

Prepping samples in Nubia, 1963
While still a graduate student at the University of Colorado, Armelagos worked on a dig in Sudanese Nubia, including human remains that dated back 500 to 10,000 years.

As Armelagos put it: “Every skeleton has a story to tell. You can tell how a person lived, and how they died.” He didn’t restrict his analysis to individual skeletons, however, applying epidemiology and demography to study patterns of illness and death among populations. This revolutionary approach to paleopathology led to a flurry of groundbreaking papers.

Working with his graduate students, Armelagos discovered tetracycline in the bones of the Nubians — the first documented case of ancient people consuming low levels of this naturally occurring antibiotic, which was likely generated by beer made from grain stored in clay pots. In 2010, he built on this work by collaborating with a chemist and leading expert in tetracycline and other antibiotics. The resulting chemical analysis of the mummy bones indicated that the ancient Nubians were deliberately brewing and consuming the therapeutic agent, providing the strongest evidence yet that the art of making antibiotics was common practice nearly 2,000 years ago.

One of Armelagos’ major contributions was this marriage of biology with archeology. He used this approach to ask “some of the really big questions of our time,” said anthropologist Debra Martin in a 2013 article about his work. “He showed how the past sheds light not only on the origins of human conditions, but where we’re going. We see that racism, for example, is as deeply embedded in human behavior as it’s ever been, and yet it’s not in our biology or genes. It’s in the way that we organize ourselves culturally that we create some of these problems around race, nutrition, health and violence.” 

Martin, a former student of Armelagos, is now a professor at the University of Nevada, Las Vegas. 

"Every skeleton has a story to tell," said Armelagos, at work in a lab during the 1980s.

Armelagos made inroads in our understanding of the evolutionary history of infectious diseases like syphilis. He was also a world expert on the impact of the human diet on evolution. In 1980, he co-wrote “Consuming Passions,” about the anthropology of eating, which was popular in book clubs and is referenced in classrooms to this day.

In addition to writing about food, he was an accomplished chef who loved to cook gourmet meals for his students and turn the dining table of his home into an extension of the classroom.

The highest honors were awarded to Armelagos for his scholarship and service to anthropology, including the Viking Medal from the Wenner-Gren Foundation, the Charles Darwin Award for Lifetime Achievement to Biological Anthropology from the American Association of Physical Anthropologists and the Franz Boas Award for Exemplary Service to Anthropology from the American Anthropological Association. In addition to Emory, where he served as chair of the Department of Anthropology from 2003 to 2009, his career included teaching positions at the University of Utah, the University of Massachusetts (Amherst) and the University of Florida.

Emory graduate Kristin Harper with Armelagos in 2013. Under his tutelage, Harper published the first phylogenetic approach to the centuries-old debate over the origins of syphilis.

Armelagos taught thousands of undergraduates and hundreds of graduate students. At the meeting of the American Association of Physical Anthropologists in 2013, former students and colleagues gathered with Armelagos for a day-long session devoted to his research and mentorship – and a bit of roasting related to his often mischievous sense of humor.

Armelagos loved to give students mementos, like his famous t-shirts imprinted with “Bone to be Wild” and a dancing skeleton. He was also well-known for his collection of air-sickness bags, amassed during his early days in the field when he would often get sick on the bumpy flights of small planes. He displayed some of his favorites in the anthropology lab, like one with a picture of a kangaroo holding open her pouch with the caption: “For that clean feeling.”

He occasionally used one of his hundreds of air-sick bags to bring food to work. “No one has ever stolen my lunch,” he said.

A private interment service will be held near St. Catherine’s Island, Georgia. A public memorial of his life and work will be held at Emory on Friday, August 29. With his estate, Armelagos endowed funds to benefit scholarship at Emory, the University of Massachusetts, and the University of Colorado. In lieu of flowers, he requested that contributions be made to these endowments, including the Armelagos-Brown Bio-Cultural Lecture and the Armelagos Graduate Teaching Award.

All photos courtesy of Armelagos' friends and colleagues.

Related:
Bone to be wild: Fleshing out a career devoted to skeletons and people
Ancient brewers tapped antibiotic secrets
Skeletons point to Columbus voyage for syphilis origins
Dawn of agriculture took toll on health
Mummies tell history of a 'modern' plague
Putting teeth into the Barker hypothesis
Scholar reads the classics -- and bones
Brain vs. gut: Our inborn food fight

Friday, April 4, 2014

Sharing the 'wow' of science

Emory chemist Doug Mulford blows a fireball at the Atlanta Science Festival expo March 29. Emory Photo/Video.

By Megan Terraso, Emory Report

Rows of children sat with rapt attention, their mouths agape at what they were seeing at the Atlanta Science Festival.

"That look of wonder is why we do it," says Douglas Mulford, director of undergraduate studies of chemistry and senior lecturer at Emory. "We wanted to show the 'wow' of science and show how fascinating it can be."

Mulford was one of many Emory faculty, staff and students who participated in 25 Emory demonstrations and exhibits at the Atlanta Science Festival March 22-29. The massive weeklong festival included more than 100 events at nearly 35 venues and everything from tours and film screenings to trivia nights and flashy science demonstrations.

At the festival's science expo March 29 at the Georgia World Congress Center, Mulford and several Emory students put on a science stage show with bubbling beakers and exploding balloons to a packed room with an audience of around 1,000.

Mulford also oversaw the very popular "cornstarch dance pit," a three foot by three foot pit where visitors could dance or sink in the cornstarch and water mix. "As long as you dance, you stay up. When you stop, you sink. That was a lot of fun," Mulford says.

Other Emory exhibits at the expo, which attracted tens of thousands of visitors, included monarch butterflies, the opportunity to touch a real brain and a booth that allowed visitors to swab the bottom of their shoe or their ear and follow the growth of the bacteria they'd swabbed over a few hours or days via a website.

Read more at Emory Report.

Thursday, March 27, 2014

If Carl Sagan had been a dancer


Theater Emory and the Emory Dance Program premiere their first collaboration, "Free/Fall: Explorations of Inner and Outer Space," on April 3 in the Mary Gray Munroe Theater.

"When astronomers talk about the cosmos, you often hear words or phrases that describe behaviors, moods, relationships, even arcs and journeys and sudden eruptions of 'emotion,'" says director Janice Akers, explaining the inspiration behind the production. "The language also has highly physical imagery: rotation, orbiting, colliding, intersecting, floating, coming towards, flying away."

Read more about the production here.

Wednesday, March 26, 2014

Festival gets all fired up for science


First-year chemistry students demonstrated the wonders of science in Emory labs last Saturday, to help launch the Atlanta Science Festival. More than 80 different organizations, including Emory, are collaborating on the week-long festival, made up of dozens of events throughout metro Atlanta, including many on the Emory campus. The festival culminates on Saturday, March 29 with a family friendly "Exploration Expo" in the Georgia World Congress Center.

Photo by Emory Photo/Video

Tuesday, March 25, 2014

How molecules are a lot like birds


Emory chemist Jay Goodwin was featured in an interview by Ari Daniel of PRI's "Living on Earth." Below is an excerpt from the interview transcript:

ARI DANIEL: Once in a while, if you’re lucky, you catch a glimpse of something that gives away a secret of the universe. It’s like a window – up into the heavens and deep into ourselves. This is a story about someone who poked his head through just this kind of window, and we find him in Atlanta. It’s a perfect day here – Jay Goodwin walks over to a bench to sit down. And he can’t help but be reminded about a day just like this one, 5 years ago, in western Michigan where he used to live.

JAY GOODWIN: I was outside – I think I was going for a walk, just to kind of clear my head a little bit. I turned a corner, and I saw this flock of birds and they took off into the sky and they started to form a shape – sort of an amorphous shape. And it was one that was dynamic, and it was changing – but it had a boundary to it, like looking at a blob of oil in water.

DANIEL: It stopped Goodwin in his tracks. Several hundred birds pulsing and dipping and soaring to an invisible beat in the sky.

GOODWIN: It wasn’t clear what they were responding to – there weren’t any predator birds in the sky. And you never got the sense that there was anything that was directing it from within. There was no leader bird that they were all following. But just watching it was, well, it was beautiful.

DANIEL: Goodwin realized he had no way of predicting the flock’s behavior by simply taking lots of individual birds flapping their wings, and adding them up. Rather, it was something that emerged once all these birds threw themselves together. And it’s this notion of emergence – how really complex patterns and properties can arise from combining somewhat simple units – that now defines how Goodwin thinks about his real work. Chemistry.

Goodwin heads into his lab at Emory University. He’s a chemist here. And since seeing that flock, he’s come to appreciate how molecules are a lot like birds. That is – you get to know how the individuals behave and parade on their own, but then, you put them together. And often, something new and astonishing emerges.

You can read the whole transcript, and listen to the podcast, on the "Living on Earth" web site.

Related:
Chemists boldly go in search of 'little green molecules'

Tuesday, March 4, 2014

Atlanta Science Festival to launch on March 22


Via Emory Alumni Association

Get in touch with your inner scientist at the Atlanta Science Festival (ASF), a weeklong celebration of local science and technology.

"From March 22-29 at more than 100 events throughout metro Atlanta, visitors will experience scientific innovation and transform their perspective on how science impacts nearly everything we do," says Sarah Peterson, a co-founder of the ASF and program coordinator for Laney Graduate School. 

Emory has been a partner in ASF from its beginning and is collaborating with more than 80 community partners on the interactive festival.

A variety of events will take place on and around the Emory campus including lab tours, panel discussions, film screenings, an opportunity to see the sun through a solar telescope, a celebration of the science of beer, and much more. Click here to see the complete list of Emory events, times and locations.

The festival will culminate Saturday, March 29 at Centennial Olympic Park with an Exploration Expo featuring family activities, experiments, pop-up interactive exhibits and games, including faculty, staff and students from Emory's science and math departments. The Exploration Expo will be from 11a.m. to 4 p.m., and admission is free.

"Whether you're a self-proclaimed science-lover or simply fascinated by the how the world works, we invite you to share in this celebration of 'the curious' in all of us," says Jordan Rose, associate director at the Emory College Center for Science Education. "There's something for everyone: comedy, art, poetry, food, lasers, stars, gardens, dinosaurs and more."

Photo courtesy San Diego Science and Engineering Festival.

Monday, February 10, 2014

Creating an atmosphere for change

"It's really not possible to understand climate change from the standpoint of one discipline," says Eri Saikawa.

By Carol Clark

Most of the faculty in Emory’s Department of Environmental Sciences look forward to getting into the field, whether it’s to track wild primates through an African rainforest, chase after bumblebees in a Rocky Mountain meadow or just splash through metro-Atlanta streams to monitor mosquitoes and their larvae.

Eri Saikawa, however, loves nothing better than being indoors, battling computer-programming bugs as she wades into murky problems involving mathematics, atmospheric chemistry, and global environmental policy.

“I was never an outdoor person,” says Saikawa, assistant professor of environmental sciences. She smiles at the irony as she sits before her computer, wrapped in a comfy throw to ward off the fall chill seeping through the windows of her fifth-floor office. Using a numerical model, she is able to analyze the link between current emissions, air quality, and the climate to understand the impact of economic activities on the environment in different parts of the world.

Saikawa is an eclectic mix of interests, experience, and knowledge. Her research into public policy and the science of emissions linked to air pollution, ozone depletion, and global warming forms a patchwork quilt of expertise that covers many of the major environmental issues facing the world today.

Since she arrived at Emory last year, Saikawa and her colleagues have identified more than two dozen faculty and staff, from anthropology to sociology, from business to public health, whose work involves climate change. “We’re hoping to knit this network of faculty together into a team at Emory,” Saikawa says. She would eventually like to see this network expand to include researchers at Georgia Tech and other nearby institutions.

“It’s really not possible to understand climate change from the standpoint of one discipline,” she says. “Our energy system is changing. Our air is changing. Our supplies of water and energy are changing. The way we use land is changing. Ecosystems are changing. It’s not just climate change. It’s really global environmental change, and change in one system affects another, and so on. We need to find ways to show how it is all connected.”

Read the whole article in Emory Magazine.

Related:
The growing role of farming and nitrous oxide in climate change
Putting people into the climate change picture

Sunday, December 15, 2013

EPA clean air proposal 'not a war on coal'



Coal-burning plants in the United States emit three percent of the entire world’s greenhouse gases, says Bill Buzbee, an environmental law expert at Emory Law.

The Environmental Protection Agency has proposed clean-air rules for how new power plants should be regulated. The proposed rules are the most recent, major step after the Supreme Court confirmed that the EPA has the power to regulate greenhouse gases.

“This is not a war on coal. This is the United States taking steps to address climate change, for which the science continues to be overwhelming,” Buzbee says.

“This does matter a lot to the world,” he adds. “If the United States does, in fact, require coal plants to do better, and it’s shown to be viable, probably pressure will be brought to bear around the world for other coal-burning countries to think about doing better as well.”

Related:
The growing role of farming and nitrous oxide in climate change
Putting people into the climate change picture

Thursday, November 14, 2013

Atlanta Science Festival offers chance for interactive outreach

"Group Intelligence," which uses the science of molecular behavior to create a flash mob experience, is one of the many activities planned for the Atlanta Science Festival.

By Carol Clark

“We’re building momentum,” says Jordan Rose, who is heading up community outreach for the first Atlanta Science Festival, set for March 22 to 29. “We have a lot to celebrate in Atlanta and Georgia when it comes to science and innovation. It’s important for the public to be aware of all the activities and career opportunities here related to science, technology, engineering and math.”

Two information sessions about the festival are coming up on the Emory campus, for faculty, staff and students who want to get involved as an exhibitor or as a science ambassador. The first session will be held on Thursday, November 14 at 5 pm in Atwood, room 316. The second session is set for Friday, November 15 at 1 pm in the Whitehead Biomedical Research Building, room 600.

The idea for the Atlanta Science Festival was sparked at Emory, says Rose, one of the co-founders of the event and associate director of Emory’s Center for Science Education. Joining Emory as founding partners are Georgia Tech and the Metro Atlanta Chamber.

More than 57 partners will be putting on events at more than 30 locations during the eight-day festival, including lectures, films, performances, exhibits, trivia contests, demonstrations, workshops, guided walks and more. Events at Emory will include public talks, tours of labs and LEED-certified buildings, and a special Theater Emory performance.

The festival will conclude on March 29 with the Exploration Expo in Centennial Olympic Park. “It will be a big, family-friendly science carnival,” Rose says.

About 100 exhibits, activities, demonstrations and performances are expected for the Expo, and the organizers are accepting proposals for booths through December 13. “We’d really like to see a strong Emory presence,” Jordan says. “We’re hoping for lots of hands-on activities, geared toward kids of different ages, that directly connect to Emory research.”

He notes that Emory exhibitors can apply for special funding being offered through the Center for Science Education and the Howard Hughes Medical Institute to cover most of their costs for participating.

Science students and faculty are also being recruited to visit K-12 classrooms during the festival. “The idea is for scientists to talk to kids about their passion for their careers and some of the unsolved questions and problems of the future,” Rose says. “We want to inspire the next generation of students to address some of those problems.”

Financial sponsors of the festival include the founding partners, as well as Mercer University, Mercer Health Sciences Center, the Center for Chemical Evolution, Georgia Bio, the Atlanta Science Tavern, Captain Planet Foundation and Women in Technology.

The Atlanta Science Festival joins a trend for cities across the country holding similar events, including the World Science Festival in New York. “The Atlanta festival is unique in its real focus on local resources and expertise,” Rose says. “We will also have a strong emphasis on the links between science and the arts,” he adds.

Wednesday, November 13, 2013

Organic chemists now forming global bonds

"When I return to Japan, I'm going to be bringing back a lot of new ideas," says Atsushi Yamaguchi, at work in an Emory lab. Chemistry labs in the NSF Center for Selective C-H Functionalization are boosting their power by collaborating instead of competing. Photo by Carol Clark.

By Carol Clark

Atsushi Yamaguchi, a graduate student of chemistry from Nagoya University in Japan, is spending most of the fall semester as an exchange student, working in the Huw Davies lab at Emory.

“In Nagoya, you only see buildings,” he says. “In Atlanta, I can see lots of trees and squirrels.”

But the best part of the exchange experience, Yamaguchi adds, is the insider’s view he’s getting of top organic chemistry labs throughout the United States that are part of the National Science Foundation’s Center for Selective C-H Functionalization (CCHF).

“Before I came here, I only talked about chemistry with my other lab members, who have my same specialty,” Yamaguchi says.

Now, he’s learning new techniques of hands-on chemistry at Emory, while also joining in regular video conferences with chemists from the 14 top U.S. research universities involved in the CCHF. “When I return to Japan, I’m going to be bringing back a lot of new ideas,” Yamaguchi says.

The CCHF, headquartered at Emory, is pioneering a whole new way for organic chemists to teach and do research. A National Center for Chemical Innovation, the CCHF is funded through a $20 million NSF grant.

“We’ve gotten used to collaborating nationally through video-conferences,” says Huw Davies, the CCHF director and Emory professor of organic chemistry. “Now we’re going international.”

Video conference sessions link the Emory lab to other top organic chemistry labs around the country through the CCHF, which is now poised to connect labs globally.

Boosted this fall by an additional $635,000 from the NSF program Science Across Virtual Institutes (SAVI), the CCHF is expanding to include organic chemistry labs in Nagoya University, the Korea Advanced Institute of Science and Technology (KAIST) in South Korea, Cambridge University in England and the Max Planck Institute in Germany.

Each year, students and post-docs from Emory and other universities involved in the CCHF can spend several months doing chemistry abroad, while foreign students spend time at labs in the United States.

“The idea is to have cultural exchanges while also building collaborative research,” Davies explains. “It’s an incredibly valuable experience for students, who will ultimately be involved in research in a global environment as organic chemistry enters a new era.”

Traditionally, organic chemistry has focused on the division between reactive, or functional, molecular bonds and the inert, or non-functional bonds carbon-carbon (C-C) and carbon-hydrogen (C-H). The inert bonds provide a strong, stable scaffold for performing chemical synthesis on the reactive groups. C-H functionalization flips this model on its head.

Watch a video on how the CCHF is changing chemistry research and education:


“Governments around the world are investing hundreds of millions of dollars into C-H functionalization research,” Davies says. “In terms of organic synthesis and new methods of synthesis, it’s where the action is.”

C-H functionalization holds the potential to make organic synthesis faster, simpler and greener, and could open up whole new ways to develop drugs and other fine-chemical products, for use in everything from agriculture to electronics.

Many challenges remain, however, before C-H functionalization can be fully optimized for broad applications. The global network forged by the CCHF brings together leading players from around the world, representing a range of specialties that will be required to make the critical breakthroughs necessary to bring C-H functionalization into the mainstream of chemical synthesis.

The CCHF’s new model for research, breaking down individual lab walls to create a global collaboration of chemists taking different approaches to similar problems, has already resulted in dozens of research papers.

The journal Science recently published a CCHF finding that resulted from a collaboration between the Davies lab at Emory and the lab of John Berry at the University of Wisconsin-Madison.

The Davies lab has developed a powerful rhodium catalyst to drive chemical reactions for C-H functionalization, and a special class of highly reactive dirhodium carbene intermediates. The lab has been refining these carbenes for more than 25 years, to tame their reactivity so they can be used to perform selective, controllable reactions.

video
Watch a video of the reaction involved in the research paper, above.

Efforts by the Davies lab and others to isolate and study the intermediate steps of the dirhodium metal complex reactions have been hindered by their extreme efficiency and speed, since they react at about 300 times per second.

The Berry lab found a way to freeze and stabilize one step of the process long enough to get an actual glimpse into the workings of the mechanism. Ultraviolet-visible spectrometry showed the formation of a new molecule as the green starting material changed to a blue color that faded over time.

More collaborators helped give an even fuller picture of the intermediate compound. Jochen Autschbach from the University of Buffalo used density function theory to predict the nuclear magnetic resonance features of the compound, and Kyle Lancaster from Cornell University elucidated the compound’s structure using a series of X-ray absorption spectroscopy experiments.

“This is a seminal paper for the fundamental understanding of this chemistry, and it could not have been done without the ability to collaborate across a wide range of specialties,” Davies says. “Our lab has been broadly making C-H bonds functional for years, but there was always this mysterious black box that we couldn’t see into during the reactions. Now we can test the theoretical, computational models we’ve developed against the actual reactions. We can gather more information about bond strength and electron properties, so we’re not doing research in the dark.”

Davies expects the breakthrough to speed up the process of refining and improving the rhodium catalyst, one of the most promising and versatile of the multiple approaches under way to bring C-H functionalization to the forefront of organic chemistry.

Related:
NSF chemistry center opens new era in organic synthesis

Wednesday, October 9, 2013

The growing role of farming and nitrous oxide in climate change

A farmer fertilizes his field in India, where consumption of nitrogen from fertilizer has shot up by 50 percent during the past 10 years.

By Carol Clark

Most people know nitrous oxide as laughing gas, used as a mild anesthetic for dental patients. What’s less well-known is that nitrous oxide is the leading cause of the depletion of the protective layer of ozone in the Earth’s atmosphere, and the third-largest greenhouse gas, after carbon dioxide and methane.

“Not many people know about the impact of nitrous oxide, and very few people are studying the nitrogen cycle,” says Eri Saikawa, an assistant professor in Emory’s Department of Environmental Studies.

Nitrous oxide is released naturally from the soil, as part of the process of microbes breaking down nitrogen. However, human activity, especially agriculture, has boosted the emission levels in recent decades. Livestock manure and fertilizers containing nitrates, ammonia or urea all generate nitrous oxide as they decompose.

“Nitrous oxide emissions stay in the atmosphere for 125 years, similar to carbon dioxide. So it’s very important that we take action now,” Saikawa says.

Saikawa, whose research is focused on emissions linked to air pollution, ozone depletion and global warming, will give an overview of her work on nitrous oxide as part of Environmental Studies’ fall lecture series. Her talk, “Laughing Gas: No Laughing Matter for Climate Change and the Environment,” is set for 4 pm on Monday, October 21 in the Math and Science Center, room N306.

Over-fertilization can degrade soil quality.
Until fairly recently, the United States was the main nitrogen consumer from fertilizers. Since 2000, however, U.S. consumption has declined about 9 percent, according to data from the International Fertilizer Industry Association.

Meanwhile, China’s nitrogen consumption from fertilizers has shot up 40 percent during the past 10 years, making it the number one consumer. And India has moved into the number two spot, with a 50 percent increase.

As the two most populous nations rapidly industrialize, they are also using more fertilizer, in an attempt to boost yields, Saikawa says. “Actually, over-fertilization wastes money and can sometimes degrade soil quality, while also creating more nitrous oxide emissions.”

In her previous position with MIT’s Center for Global Change Science, Saikawa developed a computer model, based on local soil temperatures and moisture content, to estimate global nitrous oxide emissions from natural sources in different regions of the world, from 1975 to 2008. The simulation was checked against the few available actual nitrous oxide measurements, including 25 locations in the Amazon, North and Central America, Asia, Africa and Europe.

The results, verifying the simulation model’s accuracy, were recently published in the journal Global Biogeochemical Cycles, and are highlighted in this month’s issue of Nature Geoscience.

Watch a data visualization of the findings, below:



“We wanted to see if we could reproduce natural soil emissions first,” Saikawa says. “Our next step is to include the agricultural components, so we can understand more about how much nitrous oxide is coming from the activities of people. We can then use the model to simulate possible future scenarios.”

Saikawa is continuing to collaborate with her former colleagues from MIT for the research into the impact of nitrous oxide on climate change and the stratosphere, which is funded by the National Oceanic and Atmospheric Administration (NOAA).

Her computer simulation revealed that El Niño weather events decrease nitrous oxide emissions in tropical South Asia, while the opposing weather pattern, La Niña, causes a spike. This variation is likely due to the change in the rainfall associated with El Niño and La Niña, and the fact that warm, wet soil boosts emission levels, Saikawa says.

The simulation also showed that in temperate regions, snow cover appears to have an effect on emissions.

“There are so many variables, and things that we don’t know about nitrous oxide emissions,” Saikawa says. “We have to get as many measurements as possible to refine and validate our model, and to determine if there are optimal agricultural practices and other ways to potentially minimize emissions. Without more knowledge, it’s difficult to make recommendations, or to regulate the emissions.”

Related:
Fertilizer runoff and the Gulf Dead Zone
Putting people into the climate change picture
Crime may rise along with Earth’s temperatures

Photos: iStockphoto.com 

Fertilizer runoff and the Gulf Dead Zone

Dead Zone graphic by NOAA.
Kristopher Hite, a post-doctoral fellow in biology at Emory, wrote about the “Dead Zone” in a guest blog post for Scientific American. Below is an excerpt:

“Each summer, after the famers of the American Midwest spread manure or spray anhydrous ammonia over their emerging crops, summer rains (usually) come and carry much of that fertilizer down a massive web of tributaries into the mighty Mississippi River. The annual spike in nutrient (mostly nitrogen, phosphorous, and potassium – NPK) causes massive algal blooms. As the algae decompose bacteria feast on the detritus only to die when there is no more food taking with them dissolved oxygen. The resultant area of low oxygen or hypoxia is eerily named the ‘Dead Zone.’ This is a slight misnomer as the area is not completely dead although the lower oxygen levels do threaten large portions of the aquatic food web. In addition to oxygen deprivation a small percentage of the blooming algae also produce lethal toxins to fish, birds, and mammals. The size of the Dead Zone varies summer to summer from about the size of Delaware to New Hampshire depending on the amount of rainfall. …

“It varies. The American Midwest experienced two straight years of drought in 2011 and 2012. Less rain meant less nutrient run-off. Though the Dead Zone was smaller than predicted by the National Oceanic and Atmospheric Administration (NOAA) in 2012, the increased rains throughout the Mississippi watershed in 2013 resulted in a Dead Zone twice as big as last year’s. Fertilizer accumulated during the drought was released with vengeance during the heavy summer rainfall this year. I am curious to see if the horrific flooding we’ve seen recently in Colorado will have any latent effect on the Gulf’s Dead Zone this fall.”

Read the whole article at Scientific American.

Related:
The growing role of farming and nitrous oxide in climate change
A social catalyst for science outreach

Thursday, September 26, 2013

Putting people into the climate change picture

A farmer examines a field baked dry by drought.

Forget the image of a polar bear stranded on a shrinking ice floe. “Climate change is not just about polar bears. It’s a societal issue,” said George Luber, associate director for climate change at the CDC’s National Center for Environmental Health.

Luber recently kicked off a fall lecture series on climate change put together by Emory’s Department of Environmental Studies. Luber is a lead author for the Intergovernmental Panel on Climate Change Fifth Assessment Report.

“If you’re a people person, you ought to care about climate change,” he said.

Rising sea levels and more extreme weather events like floods, droughts, wildfires, major storms and heat waves are some of the better-known examples of how humans will be affected, he said.

What’s harder to grasp is how a warmer planet can cause catastrophic snowfall. Diminished ice coverage in the Great Lakes, Luber explained, makes more water available for evaporation, which can translate to heavier snowfall in the winter.

“Cities and climates are co-evolving in a manner that will place more populations at risk,” he said. He noted that, in 2008, the proportion of people living in cities reached 50 percent for the first time.

One confusing aspect of climate change is variation in the trend of warmer weather. Here's a great animation explaining the difference between trend and variation:


Heat waves are generally alleviated by cooler evenings, enabling people to better withstand the shock of extreme daytime temperatures. That’s changing, however, as urban heat island effects are allowing almost no cooling at night, Luber said. He cited a recent record high for a night-time temperature in Phoenix of 99 degrees.

A few other health impacts Luber noted:

Higher urban temperatures cause an increase in harmful ozone concentrations.

Wind-carried dust, including such dramatic displays as haboobs, help disperse fungal infections like Valley Fever.

Harmful algae blooms and their associated toxins could be spurred by warmer than usual water temperatures and other factors related to climate change.

Higher temperatures, drought and torrential rainfall stress plants and degrade agricultural cops. Elevated carbon dioxide levels also lower the protein concentrations in grains that feed the world.

Lyme disease, spread by ticks, and other vector-borne diseases, such as malaria, dengue fever and West Nile virus, are expected to expand their prevalence and range.

A dust storm closes in on homes in Phoenix.

Mental health is another concern, as people deal with everything from the trauma of extreme weather events to the day-to-day stress of a booming population in a warming world. “Much like a previous generation feared nuclear annihilation, climate change weighs on kids today,” Luber said. “Paralysis is an easy consequence of all this fear.”

Uriel Kitron, chair of environmental studies, put together the lecture series for students in his Seminar on Environmental Studies. Others are welcomed to attend the talks, but be forewarned: It’s standing room only.

“The goal is to give a better understanding of the human impact on the environment and the acuteness of the problem of a changing climate,” Kitron says. “We can’t just sit back and watch.”

Five more talks are planned for the series, which continues through December 2. Upcoming speakers include Eri Saikawa, from Emory’s Department of Environmental Studies, Karen Levy, of Rollins School of Public Health, and Daniel Rochberg, an Emory graduate who is now with the U.S. State Department. Click for the full schedule: Talks begin at 4 pm in the Math and Science Center, room N306.

Related:
Crime may rise along with Earth's temperatures
Why the future of fuel lies in artificial photosynthesis

Photo credits: Top, istockphoto.com; bottom, Wikipedia Commons.

Wednesday, September 18, 2013

Herty Medalist adds life to chemistry outreach

As David Lynn researches how life first evolved, he is finding ways to explain the complex science to the public. Photo by Ann Borden.

By Carol Clark

Georgia chemist Charles Herty applied his research to transform the economy of the South, and his charisma to become a crusader for the profession. Herty traveled the nation, from 1915 until he died in 1938, delivering spell-binding talks and sparking conversations about the importance of chemistry among politicians, academics, businessmen and women’s clubs.

His legacy lives on through the Charles H. Herty Medal, awarded this year to David Lynn, the Asa Griggs Candler Professor of Chemistry and Biology at Emory. The gold medallion, inscribed with “pro scientia et patria” (for science and country), is given annually by the Georgia Section of the American Chemical Society (ACS) to recognize outstanding work and service of a chemist or chemical engineer from the 11 states of the Southeast.

“The award celebrates the ability of scientists to give back to a community in many different ways. That’s what makes it so special to me,” Lynn says.

“David was selected for his role in advancing the understanding of chemical evolution, and for his service in public outreach for the chemical sciences. He’s a true leader in both areas,” says Rigoberto Hernandez, a chemist at Georgia Tech and current chair of the Herty Award Committee.

The medal, one of the oldest awards of the ACS, and the highest honor given by the Georgia Section, was presented to Lynn at the 79th Annual Herty Award Celebration in Atlanta.



As the honoree, Lynn's talk for the event was entitled “Towards Intelligent Materials,” describing how, during the past decade, our understanding of evolutionary processes and the tree of life has changed more than at any time since Charles Darwin.

“The rate at which technological advances and insights are emerging,” Lynn says, “now demands that we reconsider several of the most fundamental and longstanding questions of our time: What is life, where might it exist, and what forms might it take?”

The Lynn lab is uncovering processes of molecular self-assembly that could boost our ability to engineer living systems. Lynn has served as chair of chemistry at Emory since 2006, and helped establish the Center for Chemical Evolution, a collaboration between Emory, Georgia Tech and other institutions, funded by the National Science Foundation and NASA. The center is testing theories for how chemical reactions may have led to life emerging on Earth some 3.5 billion years ago. Harnessing these forces of evolution could help in everything from drug design to genome engineering.

“I’m a scientist first, and I’m most excited about the discoveries we’re making,” Lynn says. “But it’s equally important to find ways to capture the imagination of the public and explain the meaning of our new knowledge.”



Lynn considers Charles Herty an inspiring role model, both as a chemist and a science ambassador.

Born in Milledgeville in 1867, Herty was a research chemist at the University of Georgia and the University of North Carolina. In 1903 he developed a simple cup-and-gutter system to collect resin from pines without killing the trees. The invention is credited with saving both the southern pine forests and the turpentine and rosin chemical industry. Herty later developed methods to make paper from young, fast-growing pine trees, laying the foundation for a forest products industry in the Southeast.

During World War I, Herty served as ACS president and helped organize chemists to work on critical defense problems like German poison gas attacks. After the war, he lobbied for the expansion of the U.S. chemical industry, and played a key role in its development into an economic powerhouse.

“He used his expertise in chemistry to identify ways that he could contribute to the Southeast, and to the country, at a time when it was really needed,” Lynn says.

Lynn was born in North Carolina, but he spent the bulk of his career at the University of Chicago. He returned to his home region when he joined Emory in 2000.

“We’re entering a challenging time in science communication, because advances are happening so fast,” Lynn says. “Meanwhile, much of the nation, particularly the Southeast, is still struggling to understand scientific theories like evolution.”

Lynn used a $1 million award from the Howard Hughes Medical Institute to create a program for graduate students to teach freshmen about their research, so that they learn to explain their science while doing it.

He frequently taps the visual arts, music and theater to get across key concepts. “Group Intelligence,” in collaboration with Out of Hand Theater for instance, involves children and adults from all walks of life in a flash mob that simulates the interactions of molecules.

“I want to spark conversations about scientific theories like evolution in unexpected places, such as a concert hall, a shopping mall, an art gallery or a park,” Lynn says. “The idea is to use art to create dialogue about the beauty and science of the world that we inhabit.”

Related:
Peptides could be 'missing link' to life
Chemists fine-tune ideas on how life evolved
Teaching evolution enters new era

Wednesday, September 4, 2013

New human health major aims at culture change



“Health is something that’s not just physical,” says Brooke Healey, a junior at Emory. “It’s so much more than that.”

Healey is majoring in human health, an interdisciplinary degree launched this fall at the university that aims to give students practical skills to develop health-related careers, along with a holistic understanding of physical, mental and spiritual well-being.

“We are offering the only bachelors of human health in the country, at a time when health is being redefined,” says Michelle Lampl, director of Emory’s Center for the Study of Human Health. “For too long, our concept of ‘health’ has been limited culturally by our construct of what it is not: The disease state. We are on the cutting edge of using science not just to cure disease, but to identify, predict and support health.”

Emory is uniquely suited to pioneer the human health major, Lampl says, drawing on expert faculty and resources from throughout the humanities and sciences. The first cohort of majors includes students interested in law, political science, economics and business, as well as public health and medicine.

“Human health is a major global issue, and at the same time is a leading sector for job growth,” Lampl says.

The human health graduates, she notes, will help expand and change not just what we mean by the word “health,” but what it means to have a health-related career.



The new major builds on the Center for the Study of Human Health’s programs such as its Health 100 course, launched in 2011, that all Emory freshman are required to take. The course, rooted in predictive health research at Emory, includes classes on topics like nutrition and exercise, as well as small-group discussions to help students manage the stress of college life. Trained upperclassmen serve as mentors, in the form of peer health partners and healthy eating partners.

“The students aren’t just gaining a new perspective on their own health,” says Lisa Dupree, the center’s associate director. “They’re learning how to help their friends, families and others change their behaviors.”

College has long been associated with burning the candle at both ends, Lampl notes, a compressed time when young people are expected to achieve a great deal, while also learning to navigate daily life on their own.

“It’s such a critical period,” she says. “We want to help students step off the moving pathway, take stock of their daily decisions, and get on the right road to true well-being.”

“My peer health partner was great,” says Healey, who recently underwent training to become one herself. “A lot of the things taught to me were valuable in terms of health, stress management and adapting to the college lifestyle.” (Watch the videos, above, to hear more feedback from the students about Emory’s human health classes.)

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Lesson No. 1: Learn to relax
A personalized approach to health education
Hydroponic lettuce offers a taste of green food
A healthy business is in his cards
Tapping traditional remedies to fight modern super bugs

Friday, August 30, 2013

Science a major draw at Decatur Book Festival


Many people would say that we are on the brink of using brain imaging to diagnose mental illness.  “I’m skeptical of that,” counters Emory psychologist Scott Lilienfeld, co-author of “Brainwashed: The Seductive Appeal of Mindless Neuroscience.”

Lilienfeld will be talking about the book as part of the Science Track of the AJC Decatur Book Festival on Saturday, August 31 at 3 pm.

“Neuro-imaging is an invaluable tool,” Lilienfeld says, “but like any tool, it can be overhyped. And I think overhyping can diminish a field’s credibility.”

He recalls when he was in graduate school during the 1980s, and the field of psychology was abuzz with the promise of the nuclear medical imaging technique known as positron emission tomography, or PET.

“A lot of people – smart people, actually – were saying that PET was going to replace the DSM (the Diagnostic and Statistical Manual of Mental Illness),” Lilienfeld says. “That, of course, never came to pass.”

The Science Track, sponsored by the Atlanta Science Tavern, has grown into one of the biggest draws for the festival, August 30 to September 1.  Some of 10 Science Track titles this year include “The Genius of Dogs: How Dogs are Smarter than we Think,” co-authored by Brian Hare (an Emory alum); “My Beloved Brontosaurus: On the Road with Old Bones, New Science, and Our Favorite Dinosaurs,” by Brian Switek; and “The Bonobo and the Atheist: In Search of Humanism Among the Primates,” by Emory primatologist Frans de Waal.

Some intriguing science titles are also part of the book festival’s Atlanta Writers Showcase, including “Life Traces of the Georgia Coast,” by Emory paleontologist Anthony Martin, who will be speaking on Sunday, Sept. 1, at 3:00 pm.

Thursday, August 22, 2013

Joel Bowman's view from the top of theoretical chemistry


"Imagine how sensational it would be if we could predict where and when a cloud will form," says Joel Bowman. Photo by Bryan Meltz, Emory Photo/Video.

By Carol Clark

As Joel Bowman flew across the country recently, on his way to collect the Herschbach Prize for theoretical chemistry, his attention turned to the clouds outside the jet’s window. What’s happening at the molecular level, he wondered, in a cloud at 30,000 feet?

“As we all know, clouds are essentially water in the gaseous state,” says Bowman, Samuel Candler Dobbs Professor of Theoretical Chemistry at Emory. “And, of course, it’s really cold at that altitude. So why do you find clouds at sub-zero temperatures? It’s an obvious but interesting question. The answer certainly has something to do with energy the cloud has absorbed from the sun and with potential energy surfaces: The delicate, attractive forces holding little water molecules together.”

Bowman’s work on developing potential energy surfaces is just one example of why he received the Herschbach Prize for Theory, presented in July at the Dynamics of Molecular Collisions 2013 Conference. The prize is named for Nobel Prize winning chemist Dudley Herschbach, who describes the award’s criteria as “bold and architectural work” that “addresses fundamental, challenging, frontier questions … and typically excites evangelical fervor that recruits many followers.”

The two-sided medal for the Herschbach Prize represents both theoretical (left) and experimental (right) molecular collision dynamics. The designer chose an angel for theory to symbolize “our yearning to attain an exalted, exhilarating comprehension."

Bowman was also recently elected to the International Academy of Quantum Molecular Sciences, and is lauded in the August 15 issue of the Journal of Physical Chemistry, the leading journal in its field. The cover art shows results from two of Bowman’s recent collaborations with experimentalists: One, concerning the dynamics of clusters of water molecules and another involving the complex kinetics of the chemicals in a comet. This special “Festschrift Issue” includes a tribute article to Bowman.

“These are all great honors to me,” says Bowman, who turned 65 this year and has no plans to retire. “Right now, I’m at the top of my game, the sweet spot of my career,” he says, citing four major research grants currently funding his group’s work.

Theoretical chemists do not work with chemicals: They write equations, analyze data and develop simulation models for molecular behaviors. It tends to be “a mature field,” Bowman says, where researchers hit their stride after years of experience, patience and perseverance.

Bowman is considered “one of the founding fathers of theoretical reaction dynamics,” the tribute authors write. (Click here to read the whole article, and more highlights from his career.) More recently, they add, he has made exceptional contributions to modeling potential energy surfaces, or PESs: “Without the PESs emerging from Joel’s group, many theorists would be unable to apply powerful methods of modern quantum dynamics to some of the most challenging problems of great current interest.”

Those problems include the molecular dynamics of water, a puzzle that particularly intrigues Bowman these days. During that cross-country plane flight, while most other passengers were probably trying not to think about things like turbulence and a stormy sky, Bowman took out his iPhone to make a video of lightning shooting through dark clouds (see below).



“What’s going on inside a cloud is extremely complicated, involving chemistry, physics, fluid dynamics and heat transfer, among other things,” Bowman says. “Clouds are full of energy, but parts of them can be cold while other parts are warming up. That’s a recipe for turbulence. Suddenly you can get a violent storm and boom! And all the action is taking place in what seems like just a simple little cloud. It’s mostly water.”

Currently, weather forecasting depends greatly on receiving continuous data from satellites and observing approaching fronts and other activity. “We can measure wind direction, high-and-low pressure, and use that information to create models, but that’s not nearly the level of data my research focuses on,” Bowman says.

Potential energy surfaces describe how water molecules bind together, and how much energy it takes to break them up into individual molecules.

“Imagine how sensational it would be if we could predict where and when a cloud will form,” Bowman says. “We’re getting closer to that ability, but we’re not there yet.”

Solving these kinds of puzzles could not only improve the accuracy of 10-day weather forecasts, it could help us predict long-term climate change, he says. “We don’t currently have the knowledge or the theoretical tools to fully understand what our climate will be like 20 to 30 years from now.”

Bowman is also exploring molecular mysteries underlying questions such as why we need water to live. “We know that we are made up of 70 to 80 percent water, and that without water, you cannot have life,” Bowman says. “And yet, from a chemical standpoint, we don’t really understand how water molecules interact with biological systems.”

"When I look at clouds, all kinds of questions come to my mind," Bowman says. Photo by Bryan Meltz, Emory Photo/Video.

Bowman joined Emory in 1986, during a time of rapid growth for the chemistry department. He has served as department chair, and helped establish Emory’s Emerson Center for Scientific Computation, becoming its acting director from 1991 to 1993. The center’s supercomputers are crucial to the Bowman Group’s work.

“Computer power has changed the field enormously,” Bowman says. “We can address problems and think about complicated chemical reactions in ways that people couldn’t dream of 20 years ago. Today, the computer winds up being almost like a laboratory where you can go in and do experiments.”

One challenge is to formulate the right question and get it onto the computer in a reasonable way, Bowman says. “Once you find the right question, and pose it correctly, getting the answer is often fairly straight-forward. Of course, then you have to interpret and understand the result that the computer spits out.”

While many of Bowman’s high-impact publications are collaborations with experimentalists, the theoretical work often begins with three or four members of his group sitting at a round table in his office, discussing a problem. “For me, the biggest joy is bouncing ideas around with my students and post-docs, questioning what’s known,” Bowman says. “And, of course, the discovery of things is a thrill. I get so excited they have to calm me down sometimes.”

Theoretical chemistry “is such a complex subject, involving math, physics, chemistry and computer science,” Bowman says. “Rather than intense focus on one thing, it involves carrying around a lot of data in your brain and thinking about many different things at the same time. That’s why when I look at clouds, all kinds of questions come to my mind and I start scratching my head.”

Related:
Behaviors of tiniest water droplets revealed
Chemists modify rules for reaction rates

Friday, July 12, 2013

Why the future of fuel lies in artificial photosynthesis


By Carol Clark

Most people, especially technical experts, may agree that we have an energy crisis, but it’s much harder to come to a consensus on how to solve it.

Fossil fuels, wind power, biofuels, geothermal power, nuclear energy and solar power are all pieces in the puzzle for how to keep Earth’s burgeoning civilization running, says Emory inorganic chemist Craig Hill.

He adds, however, that an energy source that will be essential to manage the crisis in the coming decades is the least developed: Artificial photosynthesis.

Hill and other top experts in the nascent field of artificial photosynthesis co-wrote an opinion piece on the topic published in the journal Energy and Environmental Science.

“Humanity is on the threshold of a technological revolution that will allow all human structures across the earth to undertake photosynthesis more efficiently than plants,” the authors write.

The 18 authors on the opinion piece, from leading research universities and national laboratories in the United States, Europe and Australia, represent the broad range of expertise, from chemistry to biology to engineering, working on the problem.

The aim of artificial photosynthesis is to use solar energy to split water, to generate hydrogen as a cheap and abundant source of carbon-free fuel.


“The development and global deployment of such artificial photosynthesis (AP) technology,” the authors write, “addresses three of humanity’s most urgent public policy challenges: to reduce anthropogenic carbon dioxide emissions, to increase fuel security and to provide a sustainable global economy and ecosystem. Yet, despite the considerable research being undertaken in this field … AP remains largely unknown in energy and climate change public policy debates.”

“Globally, our energy requirements our expected to double in the next 30 to 40 years, maybe less,” Hill says. “It’s a staggering problem that puts everything else in perspective. Everything derives from energy. If we don’t have enough energy, we’re not going to have enough food and water.”

Fracking has opened up new sources of fossil fuels in the United States, but ultimately fossil fuels are going to run out. Fossil fuel use is also coming at a rapidly escalating environmental cost, including rising global temperatures and acidification of the oceans.

The only energy source that can come close to sustainably powering our long-term needs is terrestrial sunlight, Hill says.

The solar power industry, which converts sunlight into electricity, continues to grow, but it has severe limitations, Hill says. A great deal of space is required for solar panels to collect the sun’s energy, and that energy must be stored in batteries.

“We’re at the point now where we have solar powered buildings and electric cars, but we are never going to be able to run airplanes and ships and most other forms of transportation on electricity,” Hill says. “That’s why we ultimately need artificial photosynthesis, which is just another way of saying solar fuel.”

The goal of artificial photosynthesis is to do what plants do, only better.

“Plants use sunlight, water and carbon dioxide to make fuel in the form of carbohydrates,” Hill explains. “The process, however, is incredibly inefficient. It works for plants because they don’t have to worry about finances.”

Scientists currently know how to mimic plant photosynthesis, but not in ways that are powerful and efficient enough for practical application. Breakthroughs are needed in both fundamental science and materials engineering, says Hill, who is working on perfecting a key aspect of the problem, a water oxidation catalyst. Hill’s lab has developed the fastest homogeneous water oxidation catalyst to date.

“Artificial photosynthesis is a tremendous challenge,” Hill says, “but it’s also tremendously exciting.”

Hill foresees that we will eventually make the necessary breakthroughs to generate solar fuel. We simply have no other choice, he adds, as the human population approaches 10 billion by 2050.

Meanwhile, Hill and the co-authors of the Energy and Environmental Science opinion piece are calling for a globalized approach to artificial photosynthesis, to help raise the field’s public policy profile, remove logistical and governmental hurdles to its development, and strengthen an international commitment to clean, sustainable energy.

They envision scenarios like a network of light capture facilities situated in coastal cities where seawater would be catalytically converted to hydrogen and oxygen.

“Photosynthesis is the great invention of life,” they write. “Like biodiversity, the atmosphere, the moon, outer-space, the human genome and the world’s cultural and natural heritage, it could be treated as subject to common heritage requirements under international law, perhaps through a specific UN or UNESCO declaration. Common heritage of humanity status putatively limits private or public appropriation; requires representatives from all nations to manage such resources on behalf of all, actively share the benefits, restrain from their militarization and preserve them for the benefit of future generations.”

Related:
Water oxidation advance aims at solar fuel
Bringing new energy to solar quest
Freshman friendship fuels bio-tech business

Images: iStockphoto.com