Thursday, August 30, 2012

Science, magic and monsters meet at book fest

The giant green dinosaur will once again rise above Decatur Square for Labor Day weekend, with the return of the Decatur Book Festival and its inflatable monster mascot, Bookzilla.

One of the most popular aspects of the festival is the Science Track organized by Atlanta Science Tavern. Emory psychologist Scott Lilienfeld has been tapped to give a short intro for a talk by Alex Stone, a physicist and a magician who will speak at 5 pm on Sunday about his new book “Fooling Houdini: Magicians, Mentalists, Math Geeks and the Hidden Powers of the Mind.”

Stone notes in his book, “the world of magic is filled with scientists and the world of science is filled with magicians.”

Lilienfeld is just one example of this phenomenon. “I’ve always loved magic tricks,” he says. “I like being fooled by them, and I like trying to figure out how I got duped.”

Magicians have contributed a lot to the science of psychology, Lilienfeld says, by demonstrating the powers of “change blindness” the “illusion of choice” and other mysterious cognitive patterns.

“One of my keen interests is the psychology of deception,” Lilienfeld says. “To me, that’s what science is all about, to minimize the possibility of deception.”

A trailer for the sci-fi book "Year Zero," one of the titles at the book fest.

The potential of thorium as a super fuel, theories of consciousness, lithium batteries, electric cars and astounding tales hidden in the human genetic code are some of the other science subjects that will be highlighted at the festival. Click here to see the complete listing of Science Track authors.

The festival also has an Environmental Issues Track including novelist Lauren Groff and Georgia ecologist Janisse Ray. A Health and Wellness Track includes a panel discussion on "Tackling Obesity Issues," moderated by Emory psychologist Linda Craighead.

Science-fiction fans will have a chance to hear Lydia Netzer talk about her metaphysical novel "Shine, Shine, Shine," and Rob Reid on "Year Zero," his novel about music pirates from outer space. (Check out the trailer for "Year Zero" in the video, above.)

Is hypnosis just hocus-pocus?
Test your behavioral IQ
Science Tavern: Mixing Buffalo wings, beer and brains

Wednesday, August 29, 2012

Analysis finds benefits to racial quotas in Brazilian higher education

“For a long time, Brazil was known as a racial democracy with little discrimination, but social science research in recent decades has shown that view was way off," says economist Andy Francis.

By Carol Clark

A racial quota system at one of the leading universities in Brazil raised the proportion of black students from low-income families, without decreasing their efforts to succeed in school, a major new study finds.

“Critics of affirmative action policies often argue that making it easier for people to get into college lowers their incentive to try hard academically. That argument doesn’t stand up to our data,” says Andrew Francis, an economist at Emory University and co-author of the study.

Francis conducted the research with Maria Tannuri-Pianto, an economist at the University of Brasilia. Their analysis of the short-term impact of racial quotas was recently published in the Journal of Human Resources.

Affirmative action has been in place for decades in the United States, but it remains controversial, especially in regards to higher education. Some states have even taken steps to weaken the policy, which does not include racial quotas.

On October 10, the debate will come back to the forefront, as the U.S. Supreme Court hears arguments in Fisher v. University of Texas at Austin. A rejected white student brought the challenge to the admission policies of UT, a flagship public university.

Boys playing soccer in a slum in Rio de Janeiro, a city of extreme poverty and wealth and the host of the 2016 Olympics.

Brazil offers a diverse and vibrant environment to study how incentives affect education and race. The country’s status as a rising star on the world stage was boosted by its winning bid to host the 2016 Olympics.

More African slaves were brought to Brazil than to all of North America. Many of their descendants have intermarried with other races in Brazil, including indigenous people and those of European and Asian descent.

“For a long time, Brazil was known as a racial democracy with little discrimination, but social science research in recent decades has shown that view was way off,” Francis says. “Generally, the darker your skin in Brazil, the less education and money you have. Brazil is a country of stark contrasts.”

Brazil is just beginning to experiment with its own brand of affirmative action. In 2004, the University of Brasilia became the first federal university to have a racial quota system. All students must pass an admissions exam in order to gain entrance to the university. The racial quota requires each department at the university to reserve 20 percent of its admission spaces for students who self-identify as black.

In order to conduct a comparative analysis, the researchers looked at two admission cycles before the quota system was enacted, and three admission cycles following implementation. The university cooperated with the researchers, giving them access to admissions scores, grades and other pertinent information.

"Brazil is a country of stark contrasts."
More than 2,000 students were interviewed over the course of the study. They were asked to self-identify as belonging to one of five racial groups, from white to black and gradations between. Photographs were taken of more than 700 students. The photos were shown to a panel of Brazilians who were asked to rate the skin tones on a scale of one to seven, from lightest to darkest.

The results showed that the racial policies boosted the numbers of the darkest-skinned students overall, from 5.6 percent to 9 percent. The successful applicants were from lower socioeconomic status families than the displaced applicants.

To analyze how the racial quota impacted student effort, the researchers looked at whether the students took a college preparation course, how many times they applied, and whether they applied to more competitive academic departments, like law and medicine.

“Based on our analysis of those factors, there was no evidence that students reduced their efforts due to racial quotas,” Francis says.

The researchers also did a comparative analysis of grades. “The policy did not impact the grades of black students,” Francis says. “There were some racial disparities before and after, with black students on average getting lower grades than white students, but the policies didn’t exacerbate this difference.”

Another aspect of the study was how the racial quotas affected racial self-identity. “We found some evidence that people misrepresented their racial identity after the quota system was enacted,” Francis says. “Some of the students told the university that they were black, but during interviews for our study, they told us that they were not black. People of intermediate skin tone were more likely to make this switch.”

People of the darkest skin tone, however, were more likely after the racial quota policy was implemented to identify themselves as black, both on their university application and for the study survey. “The racial quota policy caused them to see themselves in a different way,” Francis says. “It seemed to reinforce and foster investments in a black identity. Race is flexible and contextual, and our data shows that public policy can have an impact on racial self-identification.”

In a recent case, the Brazilian Supreme Court unanimously upheld the constitutionality of the racial quota system, giving the federal government a green light for implementing more racial quotas as it seeks to correct economic imbalances.

“We hope our data helps shape Brazil’s racial policy,” Francis says, adding that additional policy interventions need to be pursued. “College entrance exam scores are lower for blacks in Brazil for many reasons,” he says. “If society is really committed to erasing inequality, policies have to impact people earlier in life than college.”

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Legacies of slavery and higher education move into the light
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All photos by

Tuesday, August 28, 2012

Capuchin economics: Monkeys on unequal pay

Outrage in the face of inequity goes way back in our evolutionary history, suggests research by Emory primatologist Frans de Waal.

In a classic experiment, de Waal demonstrated that capuchin monkeys reject unequal rewards. In a video clip from a recent de Waal talk for TED (see above), you can see what happens when one monkey receives a cucumber for a task, while another monkey receives a grape for the same task.

“It’s basically the Wall Street protests,” de Waal says.

De Waal will be one of the featured speakers at a major Emory conference devoted to the topic of fairness, set for October 18-19. “What is Fair? An Interdisciplinary Relection on the Meanings of Fairness” will bring together psychologists, ethicists, lawyers, anthropologists, economists and former President Jimmy Carter to explore the many layers of a complex subject.

Monkeys, mankind and morality
The bi-polar ape, in love and war

Thursday, August 23, 2012

Biophysicists unravel secrets of genetic switch

"I hope this kind of experiment will lead to better understanding of how our own DNA is compacted into chromosomes, and how it unravels locally to become expressed," says biophysicist Laura Finzi.

By Carol Clark

When an invading bacterium or virus starts rummaging through the contents of a cell nucleus, using proteins like tiny hands to rearrange the host’s DNA strands, it can alter the host’s biological course. The invading proteins use specific binding, firmly grabbing onto particular sequences of DNA, to bend, kink and twist the DNA strands. The invaders also use non-specific binding to grasp any part of a DNA strand, but these seemingly random bonds are weak.

Emory University biophysicists have experimentally demonstrated, for the fist time, how the nonspecific binding of a protein known as the lambda repressor, or C1 protein, bends DNA and helps it close a loop that switches off virulence. The researchers also captured the first measurements of that compaction.

Their results, published in Physical Review E, support the idea that nonspecific binding is not so random after all, and plays a critical role in whether a pathogen remains dormant or turns virulent.

“Our findings are the first direct and quantitative determination of non-specific binding and compaction of DNA,” says Laura Finzi, an Emory professor of biophysics whose lab led the study. “The data are relevant for the understanding of DNA physiology, and the dynamic characteristics of an on-off switch for the expression of genes.”

Lysis plaques of lambda phage on E. coli bacteria.

C1 is the repressor protein of the lambda bacteriophage, a virus that infects the bacterial species E. coli, and a common laboratory model for the study of gene transcription.

The virus infects E. coli by injecting its DNA into the host cell. The viral DNA is then incorporated in the bacterium’s chromosome. Shortly afterwards, binding of the C1 protein to specific sequences on the viral DNA induces the formation of a loop. As long as the loop is closed, the virus remains dormant. If the loop opens, however, the machinery of the bacteria gets hi-jacked: The virus switches off the bacteria’s genes and switches on its own, turning virulent.

“The loop basically acts as a molecular switch, and is very stable during quiescence, yet it is highly sensitive to the external environment,” Finzi says. “If the bacteria is starved or poisoned, for instance, the viral DNA receives a signal that it’s time to get off the boat and spread to a new host, and the loop is opened. We wanted to understand how this C1-mediated, loop-based mechanism can be so stable during quiescence, and yet so responsive to switching to virulence when it receives the signal to do so.”

Transient-loop formation, left, occurs due to non-specific binding of proteins (small orange disks) to DNA (black line). DNA is attached at one end to the glass surface of a microscope flow-chamber and at the other end to a magnetic bead (large gray disk) that reacts to the pulling force of a pair of magnets. The weak, non-specific DNA-protein interactions are disrupted as the force increases. (Graphic by Monica Fernandez.)

Finzi runs one of a handful of physics labs using single-molecule techniques to study the mechanics of gene expression. In 2009, her lab proved the formation of the C1 loop. “We then analyzed the kinetics of loop formation and gained evidence that non-specific binding played a role,” Finzi says. “We wanted to build on that work by precisely characterizing that role.”

Emory undergraduate student Chandler Fountain led the experimental part of the study. He used magnetic tweezers, which can pull on DNA molecules labeled with miniscule magnetic beads, to stretch DNA in a microscope flow chamber. Gradually, the magnets are moved closer to the DNA, pulling it further, so the length of the DNA extension can be plotted against the applied force.

“You get a curve,” Finzi explains. “It’s not linear, because DNA is a spring. Then you put the same DNA in the presence of C1 protein and see how the curve changes. Now, you need more force to get to the same extension because the protein holds onto the DNA and bends it.”

Specifically-bound proteins are shown as orange ovals on a thicker part of the DNA sequence and non-specifically bound proteins are portrayed as gray ovals on regular DNA. Non-specific, transient loops facilitate the coming together of the specifically-bound proteins that mediate formation of the “switch loop”. Once this loop is formed, non-specifically bound protein further stabilize it by increasing the length of the closure in a zipper-like effect. (Graphic by Monica Fernandez.)

An analysis of the data suggests that, while the specific binding of the C1 protein forms the loop, the non-specific binding acts like a kind of zipper, facilitating the closure of the loop, and keeping it stable until the signal comes to open it.

“The zipper-like effect of the weaker binding sites also allows the genetic switch to be more responsive to the environment, providing small openings that allow it to breathe, in a sense,” Finzi explains. “So the loop is never permanently closed.”

The information about how the C1 genetic switch works may provide insights into the workings of other genetic switches.

“Single-molecule techniques have opened a new era in the mechanics of biological processes,” Finzi says. “I hope this kind of experiment will lead to better understanding of how our own DNA is compacted into chromosomes, and how it unravels locally to become expressed.”

Other authors on the paper include Sachin Goyal, formerly a post-doc in the Finzi lab; Emory cell biologist David Dunlap; and Emory theoretical physicist Fereydoon Family. The research was funded by the National Institutes of Health.

Undersea cables add twist to DNA research
A physicist's view of life

Image credits: DNA (top) by; lamba phage by Madboy via Wikipedia Commons.

Wednesday, August 22, 2012

Acai berries can lengthen lives of fruit flies

Harvesting acai berries in the Brazilian Amazon. Products made from the berries are sold around the world, and are often marketed as health supplements.

By Quinn Eastman, Woodruff Health Sciences Center

Bewildered by the array of antioxidant fruit juices on display in the supermarket and the promises they make? To sort out the antioxidant properties of fruits and berries, scientists at Emory University School of Medicine turned to fruit flies for help.

They found that a commercially available acai berry product can lengthen the lives of fruit flies, when the flies’ lives are made short through additional oxidative stress. Under certain conditions (a simple sugar diet) acai supplementation could triple flies’ lifespans, from eight to 24 days. Acai could also counteract the neurotoxic effects of the herbicide paraquat on the flies.

The results were recently published by the journal Experimental Gerontology, which awarded the paper its inaugural "Outstanding paper" prize. The lead author is Alysia Vrailas-Mortimer, a postdoctoral fellow in Emory University School of Medicine’s Department of Cell Biology. Vrailas-Mortimer says she didn’t start out focusing on acai. But acai worked better than several other antioxidant products such as vitamins, coenzyme Q10 and lutein.

"One thing that makes our work distinctive is that we tried commercially available supplements," she says. "We went to a health food store and filled up a basket."

She says she began the project with the help of undergraduate student Rosy Gomez, and narrowed her focus after initial success with acai. Vrailas-Mortimer took advantage of a discovery she had made working with Subhabrata Sanyal, assistant professor of cell biology. They had previously found that flies with mutations in the "p38 MAP kinase" gene have shorter lives and are more sensitive to heat, food deprivation and oxidative stress.

P38 mutant flies lived an average of only eight days when they were given a simple sugar water diet. However, their lifespans tripled when their diet was supplemented with acai. Ginger was used as a control for the diet supplements.

Acai also protected normal flies against oxidative stress, in the form of hydrogen peroxide or paraquat. Acai can protect against oxidative stress when flies are exposed to hydrogen peroxide before being given acai, but the protective effect does not hold up if the order is reversed.

Paraquat is an herbicide that has neurotoxic effects that resemble Parkinson’s disease. Under the influence of paraquat, flies’ sleep-wake cycles gradually become chaotic (see graph, above). Acai can also help soften the effects of paraquat on flies’ circadian rhythms.

"I think this is important," Vrailas-Mortimer says. "We show that whatever is in acai that is lengthening lifespan, it can also keep the flies functioning better for longer when faced with paraquat exposure. It is maintaining quality of life rather than just preventing them from dying."

Read more at Emory News Center.

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Tapping traditional remedies to fight modern super bugs
Monarch butterflies use medicinal plants


Tuesday, August 21, 2012

Sanctuary chimps show high rates of drug-resistant staph

By Carol Clark

Chimpanzees from African sanctuaries carry drug-resistant, human-associated strains of the bacteria Staphylococcus aureus, a pathogen that the infected chimpanzees could spread to endangered wild ape populations if they were reintroduced to their natural habitat, a new study shows.

Young, motherless chimps need close contact.
The study by veterinarians, microbiologists and ecologists was the first to apply the same modern sequencing technology of bacterial genomes used in hospitals to track the transmission of staph from humans to African wildlife. The results were published today by the American Journal of Primatology.

Drug-resistant staph was found in 36 chimpanzees, or 58 percent of those tested at two sanctuaries, located in Uganda and Zambia. Nearly 10 percent of the staph cases in chimpanzees showed signs of multi-drug resistance, the most dangerous and hard to cure form of the pathogen.

“One of the biggest threats to wild apes is the risk of acquiring novel pathogens from humans,” says study co-author Thomas Gillespie, a primate disease ecologist at Emory University.

The study was led by Fabian Leendertz, the head of emerging zoonosis at the Robert Koch Institute in Berlin. Other co-authors were from the University Hospital Munster in Germany, the Ngamba Island Chimpanzee Sanctuary in Uganda and the Chimfunshi Wildlife Orphanage in Zambia.

Antibiotic resistance is rare in wild apes, with only one case of drug-resistant staph ever identified in them, Gillespie notes. That’s a stark contrast to ape sanctuaries, where necessary close contact with human caretakers promotes cross-species pathogen transmission.

“We thought that our study would find some pathogen transmission from humans to the apes, but we were surprised at the prevalence of drug-resistant staph we found in the animals,” Gillespie says. “It mirrors some of the worst-case scenarios in U.S. hospitals and nursing homes.”

Multi-drug resistant staph is a major human health problem, causing an estimated 94,000 life-threatening infections and more than 18,000 deaths annually in the United States alone. It’s unclear the magnitude of the effect the disease could have if accidentally introduced to populations of naïve wild apes.

The researchers hope that their findings influence the policies at ape sanctuaries, since many of them are under growing pressure to reintroduce rescued animals to the wild.

Sanctuaries serve an important function at the interface of animal welfare and species conservation, Gillespie says. “Both animal welfare and conservation are ethical imperatives, but what promotes one does not inevitably benefit the other. That’s just one of the many things that we’re learning as we work to conserve and care for chimpanzees.”

The prevalence of drug-resistant staph in sanctuary chimpanzees may also pose a risk to humans, Gillespie says, due to the close genetic relationship between primates and people.

“The chimpanzee may serve as an incubator where the pathogen can adapt and evolve, and perhaps jump back to humans in a more virulent form,” he says.

The booming human population in sub-Saharan Africa, and the resulting overlap of human activity in wild primate habitats, increases the risk of such cross-species transmission of pathogens, the researchers warn.

Gorilla vet tracks microbes for global health
Captive chimps up for endangered status
Tapping traditional remedies to fight modern super bugs

Friday, August 17, 2012

Behaviors of tiniest water droplets revealed

Water mediates all biological processes, but we still don't fully understand its behavior.

From Science Daily:

“A new study by researchers at the University of California, San Diego, and Emory University has uncovered fundamental details about the hexamer structures that make up the tiniest droplets of water, the key component of life – and one that scientists still don't fully understand.

“The research, recently published in the Journal of the American Chemical Society, provides a new interpretation for experimental measurements as well as a vital test for future studies of our most precious resource. Moreover, understanding the properties of water at the molecular level can ultimately have an impact on many areas of science, including the development of new drugs or advances in climate change research.

A 3-D model of the prism structure of the water hexamer, the smallest drop of water. "Ours are the first simulations that use an accurate, full-dimensional representation of the molecular interactions and exact inclusion of nuclear quantum effects through state-of-the-art computational approaches," says study co-author Joel Bowman, a theoretical chemist at Emory University. "These allow ws to accurately determine the stability of the different isomers over a wide range of temperatures."

‘"About 60% of our bodies are made of water that effectively mediates all biological processes,’ said Francesco Paesani, a study co-author and a biochemist at UC San Diego. ‘Without water, proteins don't work and life as we know it wouldn't exist. Understanding the molecular properties of the hydrogen bond network of water is the key to understanding everything else that happens in water. And we still don't have a precise picture of the molecular structure of liquid water in different environments.’

“As described in the JACS paper, researchers have determined the relative populations of the different isomers of the water hexamer as they assemble into various configurations called 'cage', 'prism', and 'book'.

A 3-D model of the cage structure of the water hexamer. The mesh contours represent the actual quantum-mechanical densities of the oxygen (red) and hygrogen (white) atoms. The small yellow spheres represent the hydrogen bonds between the six water molecules. Model images courtesy of UC San Diego.

“The water hexamer is considered the smallest drop of water because it is the smallest water cluster that is three dimensional, i.e., a cluster where the oxygen atoms of the molecules do not lie on the same plane. As such, it is the prototypical system for understanding the properties of the hydrogen bond dynamics in the condensed phases because of its direct connection with ice, as well as with the structural arrangements that occur in liquid water.

“This system also allows scientists to better understand the structure and dynamics of water in its liquid state, which plays a central role in many phenomena of relevance to different areas of science, including physics, chemistry, biology, geology, and climate research. For example, the hydration structure around proteins affects their stability and function, water in the active sites of enzymes affects their catalytic power, and the behavior of water adsorbed on atmospheric particles drives the formation of clouds.”

Read the whole article in Science Daily.

Crystal-liquid interface visible for first time
Chemists reveal the force within you

Top photo by

Frequent massage boosts biological benefits

By Kathi Baker, Woodruff Health Sciences Center

Repeated massage therapy delivers sustained, cumulative beneficial effects, a new study shows. The effects persist for several days to a week, and differ depending on the frequency of sessions. Results of the study were reported in the Journal of Alternative and Complementary Medicine.

The researchers, led by Mark Hyman Rapaport, examined the biological effects of repeated Swedish Massage Therapy and light touch intervention. In a prior study, the researchers found that healthy people who undergo a single session of Swedish Massage experience measureable changes in their body’s immune and endocrine response.

"We expanded the study to show the effects of repeated massage because we believed the frequency of massage, or the interval between massages, may have different biological and psychological effects than a single session," explains Rapaport, chair of the Department of Psychiatry and Behavioral Sciences at Emory University School of Medicine.

The study was conducted over five weeks, assessing neuroendocrine and immune parameters. Study volunteers were randomized into four intervention groups to receive a concurrent five weeks of Swedish Massage once a week or twice a week, or a light touch control once a week or twice a week.

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Meditation benefits foster children
Are hugs the new drugs?

Thursday, August 16, 2012

Democracy works for Endangered Species Act

The Bald Eagle, a living symbol of democracy as the national bird of the United States, was on the "threatened" list for the lower 48 states until 2007. Photo by Saffron Blaze via Wikipedia Commons.

By Carol Clark

When it comes to protecting endangered species, the power of the people is key, an analysis of listings under the U.S. Endangered Species Act finds.

The journal Science is publishing the analysis comparing listings of “endangered” and “threatened” species initiated by the U.S. Fish and Wildlife Service, the agency that administers the Endangered Species Act, to those initiated by citizen petition.

“We found that citizens, on average, do a better job of picking species that are threatened than does the Fish and Wildlife Service. That’s a really interesting and surprising finding,” says co-author Berry Brosi, a biologist and professor of environmental studies at Emory University.

The "threatened" gray wolf. Photo by FWS.
Brosi conducted the analysis with Eric Biber, a University of California, Berkeley School of Law professor who specializes in environmental law.

Controversy has surrounded the Endangered Species Act (ESA) since it became law nearly 40 years ago. A particular flashpoint is the provision that allows citizens to petition the Fish and Wildlife Service (FWS) to list any unprotected species, and use litigation to challenge any FWS listing decision. Critics of this provision say the FWS wastes time and resources processing the stream of citizen requests. Another argument is that many citizen-initiated listings are driven less by concern for a species than by political motives, such as blocking a development project.

The study authors counter that their findings bolster the need to keep the public highly involved.

“There are some 100,000 species of plants and animals in North America, and asking one federal agency to stay on top of that is tough,” Biber says. “If there were restrictions on the number of citizen-initiated petitions being reviewed, the government would lose a whole universe of people providing high-quality information about species at risk, and it is likely that many species would be left unprotected.”

Only about 2,000 American Crocodiles, an ESA-protected species, remain in Florida. Photo by Tomas Castelazo via Wikipedia Commons.

The researchers built a database of the 913 domestic and freshwater species listed as “threatened” or “endangered” under the ESA from 1986 on. They examined whether citizens or the FWS initiated the petition, whether it was litigated, and whether it conflicted with an economic development project. They also looked at the level of biological threat to each of the species, using FWS threat scores in reports the agency regularly makes to Congress.

The Northern Spotted Owl. Photo by FWS.
The results showed that listings resulting from citizen-initiated petitions are more likely to pose conflicts with development, but those species are also significantly more threatened, on average, than the species in FWS-initiated petitions.

“The overriding message is that citizen involvement really does work in combination with the oversight of the FWS,” Brosi says. “It’s a two-step system of checks and balances that is important to maintain.”

The public brings diffuse and specialized expertise to the table, from devoted nature enthusiasts to scientists who have spent their whole careers studying one particular animal, insect or plant. Public involvement can also help counter the political pressure inherent in large development projects. The FWS, however, is unlikely to approve the listing of a species that is not truly threatened or endangered, so some petitions are filtered out.

“You could compare it to the trend of crowdsourcing that the Internet has spawned,” Brosi says. “It’s sort of like crowdsourcing what species need to be protected.”

Many people associate the success of the ESA with iconic species like the bald eagle and the whooping crane.

The Mojave Desert population of the Desert Tortoise is in the highest threat category of the ESA. Photo by FWS.

“To me,” Brosi says, “the greater accomplishment of the act is its protection of organisms that don’t get the same amount of attention as a beautiful bird or mammal.”

For example, the FWS turned down a petition to list the Mojave Desert population of the Desert Tortoise, Gopherus agassizii, but that decision was reversed. The Desert Tortoise is now in the ESA highest threat category, and populations of the entire species are thought to have declined by more than 90 percent during the past 20 years.

“One of the biggest threats it faces is urban and suburban expansion, which could have made it politically challenging for the FWS,” Brosi notes. “And yet, the Desert Tortoise is a keystone species that helps support dozens of other species by creating habitats in its burrows and dispersing seeds.”

A glimpse of world's most elusive gorillas
Captive chimps up for endangered status
The risks of returning rescued apes to the wild

Tuesday, August 14, 2012

'Smart bandage' knows when bleeding stops

Imagine a stick-on bandage that looks just like the one your mother put on your scraped knee, but it has special powers. This bandage is coated with an invisible layer of graphene, a nano-material that is 1,000 times stronger than steel, yet only one molecule thick and extremely flexible. The graphene coating speeds up the wound-healing process, then gives a signal when the bleeding has stopped.

Graphene is a lattice of carbon atoms.
In the above video, researchers discuss their prototype of this “smart bandage.” The inventors, who have filed a provisional patent, include Emory pediatrician Wilbur Lam, who is trained in hematology and bioengineering, and Zhigang Jiang and Anton Siderov, both physicists at Georgia Tech.

Animal studies have shown that graphene causes blood clots to form if the material is used internally, a red flag to the biomedical community.

“We’re flipping that around and using that to our advantage,” Lam explains. “It might not be safe to use graphene in vivo, but perhaps on the outside, where you have a vascular injury, you actually want to induce clot formation.”

The electrochemical properties of graphene add to its potential for making a better bandage, particularly for chronic wounds, Lam adds. “During clot formation on a graphene bandage there’s an electrical signal that changes. So now you have this bandage that is not only better at inducing clotting, but you have a way to detect when a clot has formed, when you’re able to peel it off.”

Graphene image: AlexanderAIUS via Wikipedia Commons.

Physics puts new lens on major eye disease

Thursday, August 9, 2012

Her patient approach to health: Tapping traditional remedies to fight modern super bugs

Cassandra Quave bridges traditional and modern medicine as an ethnobotanist, studying human interactions with plants.

By Carol Clark

Cassandra Quave was first immersed in the battle against infectious diseases when she was 3 years old and hospitalized with a life-threatening case of staph.

“That’s probably why I feel a strong connection to people who deal with these kinds of infections,” says Quave, a graduate of Emory College who is now a visiting assistant professor at Emory’s Center for the Study of Human Health.

Quave just received a $1.8 million grant from the National Institutes of Health to pursue her research into how an extract from a tree common in forests across Europe might help fight antibiotic-resistant staph. The five-year project led by Quave will include collaborators from the Emory Institute for Drug Development, the University of Iowa and Montana State University.

She notes that prolific use of modern drugs in our society helped turn multi-drug resistant Staphylococcus aureus (MRSA) into the leading cause of invasive disease in the U.S., killing more people every year than AIDS. And the remedies of traditional healers may lead to better ways of treating it.

Quave draws from the knowledge of rural people like 82-year-old Donato Sabato of Italy, who uses Malva sylvestris stems to treat stomachache. Photo by Cassandra Quave.

“Ideally, we should combine the best of both modern medicine and complementary alternative medicine,” says Quave. She bridges the two worlds as a medical ethnobotanist, studying human interactions with plants.

At 34, Quave already has a utility patent for one promising medicinal plant extract, and has filed a disclosure for a second patent. In 2011, she formed the bio-venture startup PhytoTEK with a friend from Harvard Business School, Sahil Patel, who is also an Emory alumnus. PhytoTEK advanced to the final round of the Harvard Business School’s Alumni New Venture Contest, placing in the top three of the global finals.

The unusual career of Quave (rhymes with “wave”) has been forged by everything from interviewing native healers in the Peruvian Amazon to undergoing dozens of major medical procedures in the United States.

She grew up in the small town of Arcadia, in a rural area of South Florida, where her mother was a teacher and her father ran a land-clearing business for agriculture. She had multiple congenital birth defects of her skeletal system, including missing part of her right calf bone. When she was 3, her right leg was amputated below the knee in an effort to improve her mobility.

“The doctors told my mother not to unwrap the bandages, but she noticed this horrible stench coming from my leg and knew that something wasn’t right,” Quave says. “As she took off the bandages, the flesh just fell off the bone. It was almost liquefied.”

Quave in the hospital, after the amputation of her lower right leg.

The toddler returned to the hospital for treatment of a severe staph infection. “I had to spend a very long time in the hospital,” she recalls. “I remember the nurses putting me in a bright-red bath of Betadine. I thought it was blood.”

Her leg had to be cut off even shorter, leaving her with a heavily scarred stump that lacks fatty tissue, making prosthetics less comfortable.

A neighbor later told Quave that she had felt sorry for her when she was a little girl and watched her struggle to climb the ladder of a slide. The neighbor thought it was terrible that Quave’s mother saw her daughter cry from the effort, and didn’t go and help.

“I’m so glad my parents had the strength not to help me do everything,” Quave says. “That made me independent. It takes a special person to raise a disabled child.”

Quave at work in the Amazon.
Like many kids, Quave enjoyed playing in the dirt or climbing a tree to be alone with a good book. During high school, she learned to operate the bulldozer and backhoe parked in the family’s yard, so she could help with her father’s business on summer breaks. Curiosity was her constant companion. She excelled in science fairs, competing at the state and international level. For her first science project, in the sixth grade, she took saliva samples from her dog, a horse and a cow for a comparative analysis. 

Nearly every year as she grew up, Quave had to return to the hospital to have her leg re-operated on. The bone had to be filed down as it kept growing out the end of the stump. She later made history as one of the first amputees to have bone lengthening surgery. “They broke my femur and implanted a kind of knob that you twist,” Quave explains matter-of-factly.

At 13, she developed scoliosis. Metal rods were surgically implanted in her back. She also had hip dysplasia, requiring her pelvis to be broken and rebuilt.

One silver lining to her slew of medical problems was pediatric orthopedist Chad Price, who also happens to be an Emory alumnus. He performed almost every surgery on Quave, except for the initial leg amputation, and became a friend and mentor that Quave still consults.

“I was a very odd, inquisitive kid, and Dr. Price took the time to listen to me and answer all of my questions,” Quave says. “He is different from most surgeons, he’s almost like a traditional healer in the way that he connects with patients,” she adds. “I remember once when I was coming out of anesthesia, and I was crying because it hurt so much. Dr. Price lay down in the bed next to me and held me.”

The metal rods implanted in Quave’s spine had to be removed after she had a bad reaction to them and her back became inflamed. Quave told one of the medical residents who saw her before surgery that she wanted the operation filmed.

“He thought that was a really strange request and said, no, but then Dr. Price said, ‘Sure, we’ll do that for you.’ I still have the VHS tape at home. It was fascinating to me, to see them chisel these rods out of my back.”

"I have as much respect for the best traditional healers as I do for the top scientists at Emory," says Cassandra Quave, right, in the Peruvian Amazon as an undergraduate at Emory.

During the 8th grade, Quave started volunteering at the local hospital’s emergency room. “I would spend Friday and Saturday nights watching doctors perform procedures in this small-town E.R. I’d make sure the patients were comfortable, bring them blankets and things,” she recalls. “I definitely had a gift for communicating with people who were sick.”

When her mother insisted that she get home before 2 am, Quave recalls arguing, “That’s when all the good drug cases and bar fights start coming in.”

Following in the footsteps of Price, Quave got her undergraduate degree at Emory, where she majored in biology and anthropology. She planned to go on to medical school and become an orthopedic surgeon. But a different path opened up when she took a tropical ecology class from Larry Wilson, an adjunct faculty in Emory’s department of environmental studies and an ecologist at Atlanta’s Fernbank Science Center. Under Wilson’s tutelage, Quave spent several months in the Peruvian Amazon, researching the therapies of traditional healers.

“You can learn a lot by listening to those people,” Quave says. “I have as much respect for the best traditional healers as I do for the top scientists at Emory.”

Traveling by boat through the Amazon. Photo by Cassandra Quave.

Quave’s leg became inflamed and infected from the rough walking on the jungle trails, but she had come prepared with antibiotics. She treated her leg and simply walked less, switching to small riverboats to travel amid the mestizo communities.

Many of the children had swollen bellies and stunted growth, telltale signs of intestinal worms. A traditional healer explained to her how the white latex from a fig tree could be made into a remedy to purge worms. The Peruvian government, however, had installed medicine chests in the remote communities, stocked with treatments for parasites and other ailments. Eventually, the supplies were used and not replenished. Meanwhile, the traditional healers had stopped training apprentices because people preferred the stronger drugs to the older ways.

“I would see all these kids with swollen bellies, and a fig tree right in the middle of the village, but no one knew how to prepare the treatment,” Quave says. “It’s a great example of why we have to understand both sets of knowledge – modern and traditional.”

A Peruvian healer shares his knowledge. Photo by Cassandra Quave.

She uses the term “complementary alternative medicine,” or CAM, adding: “There is a reason it’s called ‘complementary.’ It doesn’t have to be just one or the other.”

An acceptance letter from a medical school was waiting for her when she returned to Atlanta during her senior year at Emory, but the Amazon had changed Quave. She no longer wanted to be an MD. A chance meeting with an Italian ethnobiologist at a conference led Quave to Southern Italy, where she conducted field research into the traditional remedies of rural people there.

She wrote a sort of “cookbook” of traditional medicine of the region. The volume, penned in English and Italian, and full of gorgeous photographs, aims to conserve both the local knowledge and the natural environment.

A weed to one person is medicine to another.
Quave also fell in love while in Italy. She married Marco Caputo, a resident of the tiny town of Ginestra, and they now have two young children. “It’s funny how fate works,” she says.

Back in the United States, Quave pursued a PhD in biology at Florida International University, where she focused on an ethnobotanical approach to drug discovery. “I felt strongly that people who dismissed traditional healing plants as medicine because the plants don’t kill a pathogen were not asking the right questions,” she says. “What if these plants play some other role in fighting a disease?”

She led a project to analyze extracts from 100 different species of plants that she had collected in Italy, guided by clues from hundreds of interviews with local people and healers. She was particularly interested in finding treatments for skin and soft-tissue infections, to help in the fight against MRSA.

This “super bug” bacterium can cause everything from mild skin irritation to death. MRSA is difficult to treat because it is constantly adapting, and has become resistant to many antibiotics. It is now common in people with weak immune systems in hospitals and nursing homes. People with implanted medical devices, like knee or hip replacements, are especially at risk since the implants provide a smooth surface that the sugary matrix of the bacteria likes to adhere to.

In 2005, the CDC reported that MRSA was responsible for an estimated 94,000 life-threatening infections and 18,650 deaths, and the rates have kept rising since then.

Rubus ulmifolius, or the elm leaf blackberry, is one plant that shows promise for treating MRSA.

Even more alarmingly, MRSA infections are on the rise in healthy, young people outside of hospitals. Those who share close quarters and have skin-to-skin contact, such as football players, are at higher risk.

Quave is uncovering promising new ways to treat MRSA by teasing apart leaves, stems, roots and bark, isolating individual plant compounds for analysis. Her first patent involves a compound from the roots of an Italian elm leaf blackberry that neutralizes the staph defense system.

“Think of it like Star Trek,” she says, explaining that after MRSA attaches to something, it can grow a biofilm that acts like a shield against antibiotics, much like a villainous space ship uses a force field to ward off weapons of the Starship Enterprise. The plant extract prevents the MRSA bacteria from attaching to anything, so it can’t throw up a force field.

Quave hopes that the extract could one day be used to coat artificial implants and catheters before they are surgically implanted, preventing MRSA from ever gaining a foothold on them.

The recent NIH grant Quave received will further her research into a second compound from a European tree. This compound, which she is identifying only as “Extract 134” until a utility patent is filed, inhibits the toxic effects of MRSA.

An Albanian woman tells her plant stories.
“One reason that MRSA can infect healthy people is that it’s really good at producing a ton of toxins that it shoots out like lasers to cause tissue damage,” Quave says. “Extract 134 turns off the MRSA system responsible for toxin production. The bacteria is still able to grow, but its weapons are turned off.”

Taking away MRSA’s tissue damaging weapons, and/or its force field, could tip the battle back into the favor of the host’s immune system, with little, or no, help from antibiotics, Quave theorizes.

“It’s more of a delicate approach. The goal is to improve patient therapy, reduce infection rates, and avoid creating more virulent strains of MRSA,” she says.

After a post-doctoral stint at the University of Arkansas for Medical Sciences, Quave joined Emory last fall. She was recruited by another one of her long-time mentors, Michelle Lampl, a physician and anthropologist who heads Emory’s Center for the Study of Human Health. Lampl founded the center last year to serve as a nexus of Emory’s diverse assets in health education, research and practices. The aim is to foster exchange among scholars whose interests span the scientific, social and cultural dimensions of health and well-being.

Quave teaches a course on medical botany while also pursuing her drug discovery research that will tap expertise from anthropology, biology, chemistry and environmental studies. “I have my finger in a lot of pies,” Quave says, “so I tend to bring together a lot of different people who might not normally mix.”

Many hurdles remain to getting the plant-based MRSA treatments from the laboratory into clinical trials, but Quave is undaunted. “I’m used to obstacles,” she says. “I’ve climbed a lot of brick walls in my life.”

All photos courtesy of Cassandra Quave.

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