Category: research

New research from the University of Georgia Franklin College of Arts and Sciences departments of microbiology and marine sciences could have a major impact on the study of the global carbon budget. Researchers have studied the Amazon River, the largest in the world in terms of discharge water, and the process by which a plume of nutrients and organisms is transferred into the ocean, creating a hotspot of microbial activity that affects many global processes, including the storage of atmospheric carbon.

The new study further reveals detail about the microbial activity of the Amazon River Plume as part of a broad project to understand the global carbon budget and its possible impacts on a changing ocean. The study, "Microspatial gene expression patterns in the Amazon River Plume," was published July 14 in the online edition of the Proceedings of the National Academy of Sciences.

"By collecting data from genes and gene transcripts in the water samples, taking billions of sequences of DNA and RNA from organisms at various places in the plume, we were able to construct the most detailed look that's ever been put together of the microbial processes in a drop of seawater," said Mary Ann Moran, Distinguished Research Professor of Marine Sciences at UGA.

UGA researchers from the Franklin College of Arts and Sciences departments of marine sciences and microbiology took samples from the plume 300 miles offshore from the Amazon River mouth, then isolated the genes of organisms using the nutrients, nitrogen, phosphorus and carbon being carried into the ocean by the river plume.

Discharge from the plume, more than 200,000 cubic meters of fresh water per second, delivers nitrogen and phosphorus to microscopic phytoplankton that live in the upper sunlit layers of the ocean. Via photosynthesis, phytoplankton capture carbon dioxide that dissolves into the ocean from the atmosphere, a mechanism that captures a larger proportion of CO2 than is consumed by the world's rainforests.

Until now, quantitative data about the microbial activity underlying this mechanism has been elusive.

Data in the paper will used be as part of a larger model of the Amazon and will be available to researchers around the world.

"The scientific community as a whole can draw new conclusions or study different aspects from the data sets," said Brandon Satinsky, a doctoral student in microbiology at UGA and lead author on the study. "It's such a large amount of water and material, and the location of the plume moves over the course of the year, from the Caribbean virtually over to Africa."

"It's first time we've had this kind of data, at this level of detail, and so now we can share with teams of modelers to help them make better predictions about the future of the system," Moran said.

The project is part of two major UGA research initiatives: ROCA, the River Continuum of the Amazon; and ANACONDAS, Amazon iNfluence on the Atlantic: CarbOn export from Nitrogen fixation by DiAtom Symbioses, both of which are led by associate professor of marine sciences Patricia Yager. The initiatives are supported by the Gordon and Betty Moore Foundation through grant GBMF2293 and the National Science Foundation.

For more on UGA research in the Amazon, see http://amazoncontinuum.org/.

The collection of quantitative data from the Amazon River Plume creates further opportunities for study for the scientific community at large. Working together, researchers from two Franklin College departments have advanced scientific knowledge and opened the door for further study on an important topic. Congratulations to the research team on the new study.

Great new work from Franklin College researchers that should garner significant attention:

Researchers at the University of Georgia and their collaborators have developed a new technique to enhance stroke treatment that uses magnetically controlled nanomotors to rapidly transport a clot-busting drug to potentially life-threatening blockages in blood vessels.

The only drug currently approved for the treatment of acute stroke—recombinant tissue plasminogen activator, or t-PA—is administered intravenously to patients after the first symptoms of ischemic stroke appear. The protein in the drug dissolves blood clots that cause strokes and other cardiovascular problems, like pulmonary embolisms and heart attacks.

"Our technology uses magnetic nanorods that, when injected into the bloodstream and activated with rotating magnets, act like stirring bars to drive t-PA to the site of the clot," said Yiping Zhao, co-author of a paper describing the results in ACS Nano and professor of physics in UGA's Franklin College of Arts and Sciences. "Our preliminary results show that the breakdown of clots can be enhanced up to twofold compared to treatment with t-PA alone."

...

Stroke is the second leading cause of death worldwide, according to the World Health Organization, while the Centers for Disease Control and Prevention estimates that one American dies from stroke every four minutes.

"We're dealing with a huge population of patients who desperately need new treatments," said Leidong Mao, paper co-author and associate professor in UGA's College of Engineering.

Medical advances can sometime appear quite far removed from the source of their greatest need - either only focused on a small aspect of a condition or only remotely connected to a future treatment regime. Zhao, Mao and their colleagues have a special intuition about getting to the essence of a problem, drug delivery in this instance, and forging solutions with the use of technology developed in their labs. Congratulations to this team of perceptive researchers as they seek to utilize technology to improve the efficiency of the t-PA drug to help stroke and heart attack victims.

Image: Professor Yiping Zhao

As science moves forward, disease treatment regimes become more refined, safer and more effective. Great news from Shanta Dhar's research lab in the department of chemistry:

Dhar, assistant professor of chemistry in the UGA Franklin College of Arts and Sciences, and Rakesh Pathak, a postdoctoral researcher in Dhar's lab, constructed a modified version of cisplatin called Platin-M, which is designed to overcome this resistance by attacking mitochondria within cancerous cells. They published their findings recently in the Proceedings of the National Academy of Sciences.

"You can think of mitochondria as a kind of powerhouse for the cell, generating the energy it needs to grow and reproduce," said Dhar, a member of the UGA Cancer Center and principal investigator for the project. "This prodrug delivers cisplatin directly to the mitochondria in cancerous cells. Without that essential powerhouse, the cell cannot survive."

Sean Marrache, a graduate student in Dhar's lab, entrapped Platin-M in a specially designed nanoparticle 1,000 times finer than a human hair that seeks out the mitochondria and releases the drug. Once inside, Platin-M interferes with the mitochondria's DNA, triggering cell death.

Dhar's research team tested Platin-M on neuroblastoma-a cancer commonly diagnosed in children-that typically originates in the adrenal glands. In preliminary experiments using a cisplatin-resistant cell culture, Platin-M nanoparticles were 17 times more active than cisplatin alone.

Improving on current therapies can be a very difficult target. But with an expanding knowledge about the role of mitochondria in cell survival, drug design and delivery mechanism on the nanoscale have scientists poised for promising breakthroughs. Great work.

Image: Shanta Dhar (center), Rakesh Pathak (right) and Sean Marrache, courtesy of UGA Photographic Services.

2014 doctoral graduate in the department of chemistry Robert J. Gilliard, Jr., has been awarded a UNCF/Merck Foundation Postdoctoral Science Research Fellowship. The award provides $92,000 and includes a stipend, research grant and travel funds for up to two years of fellowship tenure:

Gilliard will pursue research projects focused on synthetic chemistry and will collaborate with John Protasiewicz of Case Western Reserve University in Cleveland, Ohio, and Hansjörg Grützmacher of ETH Zürich—an engineering, science, technology, mathematics and management university in Zürich, Switzerland. Gilliard will depart for Zürich in August.

"This is a tremendous honor for which I am extremely grateful," said Gilliard, a native of Hartsville, South Carolina, who came to UGA in 2009 to work with Gregory H. Robinson, the Foundation Distinguished Professor of Chemistry. "My experience at UGA has been highly rewarding in research as well as teaching, and I'm looking forward to these new opportunities for collaboration."

Gilliard is one of UGA's best, who chose to come to the university to work with our best faculty. In Gilliard's case, that meant Foundation Distinguished Professor of Chemistry Gregory H. Robinson. said Robinson of Gilliard:

"Robert arrived at UGA with a clear career plan, and he has worked hard to realize his ambition, forging new directions in the synthetic organic chemistry of beryllium."

An extraordinarily bright young researcher and teacher, Gilliard has already achieved great, early career distinction and we look for more in the future. Congratulations to Gilliard and to the department of chemistry on this prestigious fellowship.

Scholarship and research support from private giving to the Franklin College avails our students and faculty of broad opportunities across every aspect of society. This short video, featuring a student and one of our donors, elaborates on the impact of giving:

More potentially transformative new research from the department of genetics, this time in the realm of transportation fuels. For sometime now, biofuels have held great promise - and have been the focus of great controversy. But the economics of the conversion process of grasses to fuels may have finally seen its last barrier fall:

Pre-treatment of the biomass feedstock—non-food crops such as switchgrass and miscanthus—is the step of breaking down plant cell walls before fermentation into ethanol. This pre-treatment step has long been the economic bottleneck hindering fuel production from lignocellulosic biomass feedstocks.

Janet Westpheling, a professor in the Franklin College of Arts and Sciences department of genetics, and her team of researchers—all members of U.S. Department of Energy-funded BioEnergy Science Center in which UGA is a key partner—succeeded in genetically engineering the organism C. bescii to deconstruct un-pretreated plant biomass.

"Given a choice between teaching an organism how to deconstruct biomass or teaching it how to make ethanol, the more difficult part is deconstructing biomass," said Westpheling, who spent two and a half years developing genetic methods for manipulating the C. bescii bacterium to make the current work possible.

The UGA research group engineered a synthetic pathway into the organism, introducing genes from other anaerobic bacterium that produce ethanol, and constructed a pathway in the organism to produce ethanol directly.

"Now, without any pretreatment, we can simply take switchgrass, grind it up, add a low-cost, minimal salts medium and get ethanol out the other end," Westpheling said. "This is the first step toward an industrial process that is economically feasible."

Emphasis mine. With no pre-treatment and the ability of microbe to transform the feedstock into ethanol (and other, higher-energy-yield fuels), this process is ready for industrial scale up. Westpheling explained how biofuels are already the standard in Brazil. Is the U.S. on the verge of a transformative fuel moment?

Image: Bales of miscanthus being transported in the U.K., courtesy of Wikimedia Commons. Miscanthus and switchgrass are the best biofuel feedstock because of the high tons-per-acre yield.

There are a number of species that have a low to negligible probability of developing cancer. These include squirrels, turtles, the mole rat and certain whales. The reasons why are linked to these species' ability to adapt their oxygen demand when faced with a low oxygen supply. That connection itself goes back to a discover by the great physiologist and Nobel laureate Otto Warburg, who hypothesized in 1924 that, whatever the secondary causes of cancer, there is only one primary cause: a cell switch to fermentation of sugars in the face of low oxygen levels. The details of this fascinating story have now been filled in a little further by UGA bioinformatics and computational bioloy professor, Regents-GRA Eminent Scholar Ying Xu:

Chronic inflammation that induces low oxygen levels, or hypoxia, is a widely accepted cause of cancer development. However, the link between hypoxia and cell proliferation is far from clear.

A new study by University of Georgia researchers presents a model explaining the connection between chronic inflammation, low oxygen levels and the resulting cell proliferation that begins the cancer process.

"A switch in energy metabolism mechanisms—from the normal oxygenic respiration our cells use to process glucose into energy to a much less efficient, much lower capacity process called anaerobic fermentation—leads to glucose accumulation," said Ying Xu, a Regents-Georgia Research Alliance Eminent Scholar and professor of bioinformatics and computational biology in the UGA Franklin College of Arts and Sciences.

According to the study, this accumulation of glucose and related signaling through the body leads to a reaction much the same as to that of damaged tissue, eventually triggering the cell proliferation that causes cancer. Specifically it leads to synthesis, export and fragmentation of hyaluronic acids, which can serve as signals for tissue repair.

A fascinating and important breakthrough, in a field reluctant to use that term but where many desperately hope for its reality. Building on the work of the past, questioning current practices, explaining a complex process through the use of simple analogs - all the hallmarks of great research. The idea that cancer cell growth might be understood as a survival reaction, to a mistaken circumstance, in the body could not have wider significance. Great work and there's no doubt more to come from Xu and his team. 

Research by associate professor of geography John Knox on the use of Facebook to track tornado debris was one of our biggest stories of last year. A nice story this week on Knox and his research in his hometown paper in Birmingham, AL:

Knox's research can be applied to more than household debris. Toxic waste, for example. What would happen if a tornado hit a Superfund site?

"So maybe at some deep point in the future we'll be issuing watch boxes or warnings or something like that having to do with debris," he said. "That sounds kind of crazy, but it's one of those things that sounds dumb until it actually happens.

"So maybe it's a good thing we've done our research. Because if a tornado hits something where you really care where that stuff is going to fall -- it's not just shingles or photographs but something else -- it'll be something where they need to Google it real quick. And maybe they find our research … maybe someday that's going to happen. Maybe there will be a polygon having to do with debris."

Nice going. Have a great Memorial Day Weekend.

Biker, lifeguard and Iowa transplant Allison Koch is making the most of her academic opportunities at UGA:

Degree objective:
A.B. in anthropology, A.B. in Latin American and Caribbean studies, minor in ecology

Freshman year, I pursued interests in archeology, interning for a semester in the archeology lab under Jared Wood. I worked on digitizing data for a Native American mound site in Southwest Georgia. The following summer, I interned in Malang, Indonesia, teaching English at a kindergarten and living with a host family for nearly two months. This was a challenging experience, but it was invaluable in directing my future academic and career path.Sophomore year, I decided to focus my anthropology interests in Latin America, specifically on cultural interactions with the neotropical forests. During that next summer, I lived on an island in Bocas del Toro, Panama, studying at the Institute for Tropical Ecology and Conservation. It was an incredible four weeks, solidifying my love for the rain forest environment and cultures of Latin America.

Fantastic. And following on our earlier post, Allison also studied in Costa Rica this past semester. This unique set of sparkling credentials she is building for herself will help transform ambition into accomplishment - a great example of what you can do at UGA. Well-rounded young scholars discovering the world, and themselves.

A new study in Nature Geoscience by UGA marine scientist Samantha Joye questions the fate of methane released from the 2010 oil spill in the Gulf and provides evidence that microbes may not be capable of removing contaminants as quickly and easily as once thought.

"Most of the gas injected into the Gulf was methane, a potent greenhouse gas that contributes to global climate change, so we were naturally concerned that this potent greenhouse gas could escape into the atmosphere," said Samantha Joye, senior author of the paper, director of the study and professor of marine science in UGA's Franklin College of Arts and Sciences. "Many assumed that methane-oxidizing microbes would simply consume the methane efficiently, but our data suggests that this isn't what happened."

Joye and colleagues from other universities and government organizations measured methane concentrations and the activity of methane-consuming bacteria for ten months, starting before the blowout with collection of an invaluable set of pre-discharge samples taken in March 2010.

The abundance of methane in the water allowed the bacteria that feed on the gas to flourish in the first two months immediately following the blowout, but their activity levels dropped abruptly despite the fact that methane was still being released from the wellhead.

This new data suggests the sudden drop in bacterial activity was not due to an absence of methane, but a host of environmental, physiological, and physical constraints that made it difficult or impossible for bacteria to consume methane effectively.

An ability to step back and see the big picture (bringing greater focus to the original view) is but one major asset of university scientists and researchers. Their goal is to gain a true assessments of any situaiton - not the quickest, nor the most rosy. Kudos to Joye, UGA and the research conglomerates supporting the work in the Gulf to follow up on earlier conclusions and keep attention focused on the consequences of this tragic spill.

Image: NASA photo of sunlight illuminated the lingering oil slick off the Mississippi Delta on May 24, 2010. The Moderate-Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this image the same day.