Friday, December 18, 2009

2010: A Science Odyssey

Crystal ball courtesy of Crystal Blue in Little Five. Photo by Carol Clark.

Anyone remember the Y2K scare? Fears that a fluke of technology would cause our entire digital world to crash with the 2000 calendar rollover were a mere distraction. As we enter 2010, we're hoping technology can save us from climate change.

The first decade of the 21st century flew by, with changes coming at breakneck speed. It's a good time to peer into the crystal ball of research. eScienceCommons asked Emory scientists for their views on key advances during the past 10 years, and what may be in store by 2020.

"The most important thing that's happened is the recalibration of our perception of the world, and a clarification of the real challenges," says David Lynn, chair of chemistry. "That relates to everything from how we understand the origins of life, to the emerging focus on predictive health, and our increased understanding of the need for renewable energy."

Lynn cited the sequencing of the human genome and the identification of new planets as two events that shook the foundations of our social structure.
NASA photo

“The existence of other planets was predicted decades ago, but now we’ve accumulated hard evidence that we’re clearly not alone – our solar system is not the only one,” he says. “And what are we going to look for on these other planets that could allow life to emerge and evolution to start? I think that is where the fun begins.”

The fast pace of discovery contributed to a polarization of views on research, particularly in areas such as stem cells and evolution.

“The theme of our recent Evolution Revolution conference was that the world is changing very quickly, and we need to understand what that means so we can make better informed decisions,” Lynn says. “The important problems, and the fact that many are interconnected, have become more clearly defined. This clarification attracts people’s attention, and means the chance of finding viable solutions goes way up.”

Emory chemists are using “directed evolution” to study ways to reprogram bacteria to perform useful tasks, from fighting disease to producing renewable hydrogen fuel.

"We are taking principles that are central to evolution and probing them to use in different ways," Lynn says.  "It's a great time to be a scientist -- the sky is no longer the limit."

For neuroscientist Elaine Walker, one of the biggest breakthroughs was the growing awareness of genetic plasticity, or the idea that DNA is not necessarily destiny. "In the past, it was generally assumed that with only a few exceptions the individual genotype was fixed at conception, and that its effects on human health and disease were relatively fixed across the life span," Walker says.

In recent years, however, we've learned that genetic mutations in the form of copy number variations and microdeletions occur much more frequently than was previously assumed. "It now appears that these mutations can occur in embryogenesis, and that they can confer risks for autism, schizophrenia and a range of other disorders," Walker says.
Adding to this paradigm shift is our understanding of epigenetics: changes in the expression of genes due to a person's physical and psycho-social environment. "I think during the next decade, we're going to see more focus on applications of epigenetics for the treatment of everything from cancer to heart disease," says Victor Corces, chair of biology and one of the pioneers of the field.

We have also learned that the brain changes significantly across the life span, a finding that overlaps with genetic plasticity. "These developments have made our research much more complex," Walker says, "but they also provide us with much more optimism about our opportunities to prevent illness."
Walker is studying whether it might be possible to identify the changes in gene expression occurring in some young people that are causing a change in brain funciton that can put them at risk for psychotic disorders.

The theory of grounded cognition has revolutionized studies of the mind during the past decade, says psychologist Larry Barsalou, a leading researcher in this field. "Previously, it was argued that you could study the cognitive system in isolation. Now we realize that you cannot understand cognition without grounding it into the body and the sensory motor system and the world," he explains.
When you think about walking, for instance, your brain fires the same parts that operate when you are actually walking.
Research is increasingly showing the impact of social processes, culture, development and emotion on cognition, he adds. “I think that during the next 10 to 30 years, theories and research of cognition processes and social processes will be increasingly integrated.”
Everything needs to be studied from an interdisciplinary perspective, Barsalou says. "A big question is how to build programs that foster this kind of work. Psychology departments are becoming very strange beasts."
Deboleena Roy’s research spans women’s studies, philosophy, neuroscience and bioethics. During the past decade, the long struggle of women and minorities to be included in clinical trials began paying off, she says. Studies of biological differences can raise thorny issues about race and gender, she adds, stressing that we need to move forward with knowledge of the mistakes of history.

"People who are the subject of research need to be involved in generating the research questions," Roy says. "The day of the scientist in a white coat working alone in a lab is over. Scientists have to learn to connect to the broader community."

Biologists Nicole Gerardo and James Taylor are taking DNA sequencing to the next level, by tapping cutting-edge technology to analyze the sequence of a complex system, the world of agricultural ants.

“We’re entering completely new territory,” says Taylor, a computer scientist specialized in bioinformatics. “DNA sequencing technology is becoming faster and cheaper, but this transition is just happening.”
Within five years, he adds, the complex data sets he is mining through a grant will likely become much cheaper and more easily obtainable.

Psychologist Joe Manns, whose work focuses on the biology of memory, views the use of genetically engineered mice and functional magnetic resonance imaging (fMRI) as transformational. While both these technologies were developed prior to the past decade, they matured and hit their stride during the past 10 years, he says.

He believes that the emerging technology of optogenetics – using high-speed optics to control genetically targeted neurons – will likely help fuel memory discoveries in the coming decade.
“Now we can put a wire into a brain and induce neurons within a region of the brain to fire, but we can’t control which neurons,” Mann says. “Optogenetics gives you anatomical precision, allowing you to target a specific neuron, along with temporal precision, because the pulses of light operate in milliseconds.”

The past decade saw wireless devices like iPods and iPhones become almost physical extensions of the human body. Google became a household word – both as a noun and a verb – as search engine technology connected our collective digital mind.

Search personalization, coupled with advances in wireless handheld devices and biometrics such as eye-tracking, will further speed changes in Web search, predicts Eugene Agichtein, who directs the Emory Intelligent Information Access Lab. “Ten years from now, computerized searches will look much different than they do today — you won’t be just typing words into a box on a screen,” he says.

Give your mind a hand
Daily pot smoking may hasten psychosis onset
DNA is not destiny
Can neuroscience read your mind?

Monday, December 14, 2009

Lottery study zeros in on risk

Most people know they are not going to get rich playing the lottery. But if you just want to buy some tickets for fun, can you improve your odds? Is a bigger jackpot a better bet? How big is big enough?

When lottery prizes climb into hundreds of millions of dollars, these are the kinds of questions Emory mathematicians Aaron Abrams (above, right) and Skip Garibaldi (above, left) get from their students. The pair decided to conduct an analysis, applying math and economic theory to analyze the rates of return and risks associated with lottery tickets. "We wanted solid numbers to help explain why playing the lottery is not a good plan," Garibaldi explains.

You can read their paper, "Finding Good Bets in the Lottery -- And Why You Shouldn't Take Them," in the January edition of the American Mathematical Monthly. Their results showed that, while a lottery ticket could theoretically be a good bet, it is always a bad investment.

Their mathematical models for the interstate lottery Mega Millions and its competitor, Powerball, demonstrated that as the jackpots grow and more tickets are sold, the extra tickets nullify the benefit of the bigger jackpot.

Smaller, single-state lotteries like Georgia's Fantasy 5 offered better rates of return, due to the larger ratio of jackpot size to total number of tickets sold, according to their analysis. "To our great surprise, in some cases single-state lotteries have had positive rates of return as high as 30 percent," Abrams says. "That is, for these drawings a $1 ticket would give you back $1.30 on average. We didn't expect this."

So why not buy lottery tickets instead of stocks? Because the odds are you won't win the lottery.

"The technical word for this is risk," Garibaldi says. "The high rate of return is only an average for all lottery tickets for a particular drawing, and most people in that drawing will not win the jackpot."

The two mathematicians applied modern portfolio theory, pioneered by economist Harry Markowitz, to compare the potential return and risk of a savings account, various stocks and bonds and lottery tickets. "When we ran the analysis, the result was: don't buy lottery tickets," Garibaldi says. "It's too risky. Even the enormous returns we found were not enough to counteract the enormous likelihood of not winning the lottery."

So most people already know this intuitively, right? What's the point of spelling it out in precise mathematical and economics terms?

"Most people don't fully understand risk," Abrams says. He points out that when people make decisions about how to allocate their money in an IRA, the prospectus gives the rate of return, but doesn't attempt to quantify the risks.

"I strongly feel that mutual fund prospectuses should include the risk data," Abrams says. "It's important for people to understand how they are spending their money."

The recent collapse of the financial system illustrates the importance of driving home the fundamentals of risk, say the two mathematicians, who both teach probability theory to freshmen.

"The field of probability has developed rapidly during the past 50 years, and we have a tremendous understanding of how randomness works," Abrams says. "But as our understanding of probability gets better, financial instruments keep growing increasingly complex."

To sum up the lesson in their lottery analysis for students: Math studies are a sure bet and a great investment.

Math's in your cards, so deal with it

Thursday, December 10, 2009

Transgenic voles key to pair bonding secrets

Emory researchers have generated the first transgenic prairie voles, a key step toward unlocking the genetic secrets of pair bonding. The advancement by Emory's Yerkes National Primate Research Center will enable scientists to perform genetic manipulations to help identify the brain mechanisms of complex social behaviors. The work, in the current issue of the Biology of Reproduction, may also have important implications for understanding and treating psychiatric disorders associated with impairments in social behavior.

The prairie vole is a naturally occurring monogamous rodent that is being used to discover the brain mechanisms underlying monogamous pair bonds.

"Domesticated lab rats and mice dominate biomedical research, but wild rodent species with more complex social behaviors are better suited for investigating the biology of the social brain. Until now, genetic engineering among rodents has been limited to lab mice and rats," says Zoe Donaldson, the lead researcher.

Watch a video of Donaldson explaining the process of creating the transgenic vole.

Single-cell prairie vole embryos were injected with a lentivirus containing a gene found in glowing jellyfish. The gene encodes a green fluorescent protein, which glows under the appropriate conditions. The prairie vole that developed from this embryo expressed the green fluorescent protein throughout its body, and the foreign gene was passed on to the offspring for multiple generations.

Larry Young, a senior investigator on the study and an expert in social behavior, will use this technology to determine whether monogamy and its associated social behaviors can be affected by manipulating a single gene. Researchers are also investigating ways to refine this technology in order to alter gene expression in certain brain regions as well as at certain developmental milestones.

Watch a talk by Young, featured speaker at Vole Conference 2009.

The science of love
How early nurturing affects adult love

Monday, December 7, 2009

Mosquito hunters invent better disease weapon

Emory researchers believe they have come up with the cheapest, most efficient way yet to monitor adult mosquitoes and the deadly diseases they carry, from malaria to dengue fever and West Nile Virus. Emory has filed a provisional patent on the Prokopack mosquito aspirator, but the inventors have provided simple instructions for how to make it in the Journal of Medical Entomology.

“This device has broad potential, not only for getting more accurate counts of mosquito populations, but for better understanding mosquito ecology,” says Gonzalo Vazquez-Prokopec, the invention’s namesake. Vazquez-Prokopec is a post-doctoral fellow working with Uriel Kitron, chair and professor of environmental studies.

“There is a great need for effective and affordable mosquito sampling methods. Use of the Prokopack can increase the coverage area, and the quality of the data received, especially for blood-fed mosquitoes. Ultimately, it can help us develop better health intervention strategies.”

In both field and lab tests, the Prokopack outperformed the current gold standard for resting mosquito surveillance – the Centers for Disease Control and Prevention Backpack Aspirator (CDC-BP). In addition to having a longer reach, enabling it to collect more mosquitoes than the CDC-BP, the Prokopack is significantly smaller, lighter, cheaper and easier to build.

Anyone with access to a hardware store, and about $45 to $70, can make the Prokopack, which uses a battery-powered motor to suck up live mosquitoes for analysis. Mosquito-borne diseases rank among the world’s top killers, and Vazquez-Prokopec hopes that more affordable and efficient surveillance methods will help save lives.

“I come from a developing country,” says the Argentine native. “I understand what it feels like to know that there is a health technology available, and to not have the money to access it.”

For decades, public health officials have struggled to conduct mosquito surveillance. One early method, with obvious drawbacks, was to expose a bit of skin and count the bites. Another low-tech method is to spray inside a home with insecticide, and gather the bugs that fall onto on a drop cloth.

Mosquito traps baited with a chemical that mimics human sweat are sometimes used to catch live adult insects. But these traps capture only females who are looking for a meal.

The CDC-BP can quickly vacuum up samples of live specimens, which can be analyzed in a lab to determine the source of blood they recently consumed. The drawbacks to the CDC-BP, however, include its heavy weight (25 pounds), its bulk and its price – about $450 to $750 in the United States.

Emory researchers used a CDC-BP in their study of West Nile Virus and urban mosquito ecology in Atlanta. They wanted to learn if mosquitoes that harbor the virus were overwintering in nooks near the ceilings of sewer tunnels. But the CDC-BP only reaches six feet, and the tunnels are 15-feet high.

With a bit of ingenuity and a few trips to the hardware store, the research team put together a solution: a plastic container, a wire screen, a plumbing pipe coupler, a battery-powered blower motor and painter extension poles. After some experimentation with these components, the Prokopack was born.

“It’s not like we woke up one day and said, ‘Let’s invent a mosquito aspirator,’” Vazquez-Prokopec explains. “It grew out of our needs during field research.”

Comparative tests with the Prokopack and the CDC-BP were conducted outdoors and in sewer tunnels during the Emory lab’s Atlanta research projects. Additional field tests were done during a dengue fever study in Iquitos, Peru, where public health technicians are trying to control mosquitoes in homes. The Prokopack, which weighs less than two pounds, collected more mosquitoes than the CDC-BP, and reached higher into ceilings and into foliage.

Collecting more mosquitoes in higher locations can give researchers more insights into their behaviors. Upper foliage, for instance, can yield more mosquitoes resting after feeding on birds. And upper walls and ceilings of homes may harbor more mosquitoes resting after a meal on humans.


Urban mosquito research creates buzz

Thursday, December 3, 2009

Monkeys can recognize faces in photos

Capuchin monkeys can recognize familiar individuals in photographs, a study by the Yerkes National Primate Research Center at Emory has found. The discovery is in the current online edition of The Proceedings of the National Academy of Sciences.

"The study not only reveals that capuchin monkeys are able to individually recognize familiar faces, but it also convincingly demonstrates they understand the two-dimensional representational nature of photographs,"
says lead researcher Jennifer Pokorny. "The fact these monkeys correctly determined which faces belonged to in-group versus out-group members, corresponding to their personal experiences, validates the conclusion that capuchin monkeys view images of faces as humans do -- as individuals they do or do not know.

For the study, the capuchins viewed photographs of four different faces. One of the four pictures was of a capuchin from their own group, which they needed to tell apart from three strangers. They also needed to do the reverse, differentiating one stranger from three familiar individuals.

“This required monkeys to look at similar-looking faces and use their personal knowledge of group mates to solve the task,” says Pokorny. "They readily performed the task and continued to do well when shown new pictures in color and in gray-scale, as well as when presented with individuals they had never before seen in pictures, though with whom they were personally familiar."

Researchers often use two-dimensional images in experiments, yet there is little conclusive evidence to suggest nonhuman primates, particularly monkeys, truly understand the image represents individuals or items in real life.

Pokorny trained under Emory primatologist Frans de Waal, who says the study is the first to show face recognition in monkeys is fundamentally similar to that in humans, indicating that face recognition is an evolutionarily ancient ability. De Waal is director of the Yerkes Living Links Center.


Study gives clue to evolution of face recognition

Chimps mirror emotions in cartoons