Wednesday, February 29, 2012

Marriage: A powerful heart drug in short supply

Getting married can have consequences for the health of your heart, years later.

By Carol Clark

Married adults who undergo heart surgery are more than three times more likely to survive the next three months than single people who have the same surgery, a new study finds.

“That’s a dramatic difference in survival rates for single people, during the most critical post-operative recovery period,” says Ellen Idler, a sociologist at Emory University and lead author of the study. “We found that marriage boosted survival whether the patient was a man or a woman.”

The Journal of Health and Social Behavior is publishing the results, which were co-authored by David Boulifard and Richard Contrada, both from Rutgers University. The study was funded by the National Institute on Aging.

While the most striking difference in outcomes occurred during the first three months, the study showed that the strong protective effect of marriage continues for up to five years following coronary artery bypass surgery. Overall, the hazard of mortality is nearly twice as great for unmarried as it is for married patients about to undergo the surgery.

During the 1960s, 72 percent of all adults over the age of 18 were married. Today, only 51 percent of them are, a record low.

“The findings underscore the important role of spouses as caregivers during health crises,” Idler says. “And husbands were apparently just as good at caregiving as wives.”

Tying the knot has been associated with longer life since 1858, when William Farr observed that marriage protected against early mortality in France. The evidence keeps accumulating that the widowed, never married and divorced have higher risks of mortality. Much of the research, however, has looked broadly across populations during an entire lifespan, or relies only on medical records.

“We wanted to zero in on a particular window of time: A major health crisis,” Idler says, “and we wanted to add the in-person element of patient interviews, in addition to the full record of their medical history and hospitalization.”

The major study involved more than 500 patients undergoing either emergency or elective coronary bypass surgery. All of the study subjects were interviewed prior to surgery. Data on survival status of the patients were obtained from the National Death Index.

While the data are inconclusive for what caused the striking difference in the three-month survival rate, the interviews provided some possible clues.

“The married patients had a more positive outlook going into the surgery, compared with the single patients,” Idler says. “When asked whether they would be able to manage the pain and discomfort, or their worries about the surgery, those who had spouses were more likely to say, yes.”

Patients who survived more than three months were nearly 70 percent more likely to die during the next five years if they were single. An analysis of the data showed that smoking history accounted for the lower survival rates in the single patients over this longer term.

“The lower likelihood that married persons were smokers suggests that spousal control over smoking behavior produces long-term health benefits,” Idler says.

When it comes to healing hearts, marriage may be powerful medicine, but it’s in increasingly short supply, Idler says, which does not bode well for aging baby boomers.

Barely half of U.S. adults are currently married, the lowest percentage ever, according to the Pew Research Center.

Photos by

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The science of love
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Friday, February 24, 2012

An evolutionary view of depression

From Woodruff Health Sciences Center

A growing body of research is showing that one of the causes of depression may be inflammation, says Andrew Miller, professor of psychiatry and behavioral sciences at Emory. Whenever the body is attacked by a pathogen, the immune system becomes activated. That causes inflammation, a process that releases protein molecules known as cytokines.

“These cytokines can actually get into the brain and start to interact with all the things that we know are important to the development of depression,” Miller says.

Depression is such a common human affliction that it seems almost hard-wired into our brains. Miller and colleagues have proposed that perhaps depression is an evolutionary byproduct of our ability to fight infection. You can read their paper in Molecular Psychiatry.

The reason depression is staying in the gene pool at such a high rate may be that depression is helping us deal with the microbial world, Miller says. “It’s helping us deal with pathogens, as opposed to dealing with other people.”

The researchers looked at genes that are associated with depression one by one, and found that almost every single one of those genes was related to the ability to fight infections.

The behaviors associated with depression, social withdrawal and loss of interest in the external world, help conserve the energy needed to fight infection and heal a wound, Miller says.

Stress can lead to inflammation and ultimately to depression. In acute cases, stress can be a beneficial response, since it ramps up the immune system to help deal with a wound or infection. Chronic stress, however, causes a constant release of cytokines that get into the brain and may cause chronic depression, Miller says.

Are depressed people too clean?
What aphids can teach us about immunity

Tuesday, February 21, 2012

Monkeys, mankind and morality

Watch a video, above, of primatologist Frans de Waal's TedxPeachtree talk on "Morality without Religion."

Monkeys and mankind have a lot in common when it comes to moral outrage over inequities, and the need to reconcile the conflicts that arise from these differences. On his Cosmic Log, Alan Boyle writes a great summary of a talk on this topic by Emory primatologist Frans de Waal at the recent meeting of the American Association for the Advancement of Science. Among the nuggets he gathered:

"Different primate species express signs of reconciliation in different ways. For example, stumptail monkeys make up by inspecting each other's rear ends, without ever looking each other in the eye. In contrast, chimps and other apes (including us hairless apes) 'need eye contact' when they reconcile their differences, de Waal said."

Read the whole article on the Cosmic Log.

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Hugs go way back in evolution

Thursday, February 16, 2012

Fruit flies use alcohol as a drug to kill parasites

By Carol Clark

Fruit flies infected with a blood-borne parasite consume alcohol to self-medicate, a behavior that greatly increases their survival rate, an Emory University study finds.

“We believe our results are the first to show that alcohol consumption can have a protective effect against infectious disease, and in particular against blood-borne parasites,” says Todd Schlenke, the evolutionary geneticist who led the research.

“It may be that fruit flies are uniquely adapted to using alcohol as medicine,” he adds, “but our data raise an important question: Could other organisms, perhaps even humans, control blood-borne parasites through high doses of alcohol?”

Current Biology is publishing the study, co-authored by Emory graduate student Neil Milan and undergraduate student Balint Kacsoh.

The results add to the growing body of evidence that some animals know how to use toxic substances found in nature as medicine.

A vicious, co-evolutionary battle is constantly ongoing between the common fruit fly, above, and tiny, parasitoid wasps that lay their eggs in the larvae of fruit flies. Photo by Andre Karwath/Wikipedia Commons.

Drosophila melanogaster, the common fruit fly that swirls around browning bananas in your kitchen, is an important biological model system. The Schlenke lab uses D. melanogaster to study how immune systems adapt to pathogens.

The fly larvae eat the rot, or fungi and bacteria, that grows on overripe, fermenting fruit. “They’re essentially living in booze,” Schlenke says. “The amount of alcohol in their natural habitat can range from 5 to 15 percent. Imagine if everything that you ate and drank all day long was 5-percent alcohol. We wouldn’t be able to live like that, but fruit flies are really good at detoxifying alcohol.”

Tiny, endoparasitoid wasps are major killers of fruit flies. The wasps inject their eggs inside the fruit fly larvae, along with venom that aims to suppress their hosts’ immune response. If the venom is effective enough, the wasp egg hatches, and the wasp larva begins to eat the fruit fly larva from the inside out. Eventually, an adult wasp emerges from the remains of the fruit fly pupa.

Adult wasps are about to emerge from fruit fly pupae, above, after eating the fruit fly larvae from the inside out. Photo by Todd Schlenke.

Some fruit flies, however, can overcome the effects of wasp venom and mount an immune response against wasp eggs. The blood cells in these fly larvae swarm over the wasp eggs and release nasty chemicals to kill them, allowing the fruit fly larvae to grow into adults.

“A constant co-evolutionary battle is going on between the immune systems of the flies and the venoms of the wasps,” Schlenke says. “Any new mechanism of defense that protects flies from wasps will tend to spread through fly populations by natural selection.”

Schlenke wondered if the fruit flies could be tapping the toxic effects of alcohol in their natural habitat to fight off wasps.

To test the theory, the researchers used a bisected petri dish filled with the yeast that fruit flies are normally fed in a lab environment. The yeast on one side of the dish was mixed with 6 percent alcohol, while the yeast on the other side remained alcohol-free. The researchers then released fruit fly larvae into the dish, allowing them to freely move to either side.

After 24 hours, 80 percent of the fruit fly larvae that were infected with wasps were on the alcohol side of the dish, while only 30 percent of the non-infected fruit fly larvae were on the alcohol side.

If fruit flies infected with wasps tap the alcohol in rotting fruit, it raises their blood-alcohol levels and their survival rates. The alcohol doesn't just kill the wasps, it essentially liquifies them. Photo by Carol Clark.

“The strength of the result was surprising,” Schlenke says. “The infected fruit flies really do seem to purposely consume alcohol, and the alcohol consumption correlates to much higher survival rates.”

Infected fruit flies that consumed alcohol beat out the wasps in about 60 percent of the cases, compared to a 0 percent survival rate for fruit fly controls that fed on plain yeast.

“The wasps aren’t as good as the flies at handling alcohol,” Schlenke says.

A developing wasp knocked out within an alcohol-consuming fly larva dies in a particularly horrible way, he adds. “The wasp’s internal organs disperse and appear to be ejected out of its anus. It’s an unusual phenotype that we haven’t seen in our wasps before,” Schlenke says.

The lab repeated the experiment using another species of wasp that specializes in laying its eggs in D. melanogaster, rather than the generalist wasp used previously. Again, 80 percent of the infected flies wound up on the alcohol side of the dish, while only 30 percent of the uninfected flies did. But the alcohol diet was far less effective against the specialist wasps, killing them in only 10 percent of the cases.

“You would expect this kind of result,” Schlenke says, “since the generalist wasp species can attack plenty of other flies, but the specialist wasps are under strong pressure to adapt to the alcohol-infused habitat of D. melanogaster.”

The researchers hope that their data will lead to more studies of how alcohol may control pathogens in other organisms, including humans.

“Although many studies in humans have shown decreased immune function in chronic consumers of alcohol, little attempt has been made to assay any beneficial effect of acute or moderate alcohol use on parasite mortality or overall host fitness following infection,” Schlenke says.

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Farming ants reveal evolution secrets

Wednesday, February 15, 2012

When music and molecules converge

Mark Gresham reviews Emory's recent music-and-science performance of "Creation of the World" for

"In the beginning was the Sound. The big bang. From that event more than 13 billion years ago, science tells us, the universe rapidly expanded and cooled enough that its white noise of energy could change into subatomic particles. Those particles later joined to form atoms, and those atoms combined to form molecules, eventually leading to the emergence of life. Biochemists are researching what harmonious chemical conditions might have led to the emergence of life.

"Science isn’t the only field to speculate about the origins of the universe and of life. Explorations of the relationship of music to the fundamental nature of the cosmos go far back in history, from the teachings of Pythagoras and the ancient Chinese “yellow bell,” which served as a foundation of not just music but of all physical measurements, to the medieval European concept of musica universalis, the 'music of the spheres.'"

Read the whole article at

Teaching evolution enters new era
A new twist on an ancient story
A geologist paints Darwin

Monday, February 13, 2012

The science of a broken heart

Valentine's Day is a time to celerate the power of love, and all the joy it can bring. But Cupid's arrow is doubled-edged: We have all had our hearts broken, or know someone who has.

"It's a popular belief that the heart is the center of emotion and can actually break. There is some truth to that," says Viola Vaccarino, chair of epidemiology at Emory's Rollins School of Public Health. Watch the above video to learn more.

The chemical basis of love
How to make your Valentine last forever

Friday, February 10, 2012

The eternal tensions of religion and science

A painting titled "Astronomer Copernicus, Conversation with God," by artist Jan Matejko.

Why did the Catholic Church put Galileo on trial for heresy when he argued that the Earth revolves around the sun? Why do many people today not believe in evolution, despite overwhelming scientific evidence?

The tension between religion and science is not something new, nor is it likely to ever go away, despite accumulating knowledge about the natural world, says Robert McCauley, director of Emory’s Center for Mind, Brain and Culture. His latest book is called “Why Religion is Natural and Science is Not.”

“Religion is cognitively natural and comes easily to the human mind. It trafficks in the kind of ideas that minds like to think,” McCauley explains. “By contrast, science is always pulling together representations and models and ideas that are quite contrary to our normal assumptions about the world.”

In other words, science often butts heads with common sense.

“A classic illustration is, even though it’s the case that we think we are all Copernicans and everyone understands that the Earth circles the sun, the fact of the matter is when we look at the night sky, we don’t see the world as Copernican,” McCauley says. “Once you undergo the intellectual exercise to see the world as Copernican, it’s startlingly unnerving.”

"Galileo Facing the Roman Inquisition," a painting by Christiano Banti.

On the other hand, the seeds of religious belief may be inherent in our minds as far back as infancy.

“We are having to figure out what other people are thinking and why they’re doing what they’re doing in order to anticipate things that they might do, whether it’s for survival in a complex social setting or a more fundamental issue of detecting agents that may want to have you for lunch, ” McCauley says.

The price of your soul: How your brain decides whether to 'sell out'
Why religion is natural and science is not

Wednesday, February 8, 2012

Metaphors activate sensory areas of brain

Regions of the brain activated by hearing textural metaphors are shown in green. Yellow and red show regions activated by sensory experience of textures visually and through touch.

By Quinn Eastman, Woodruff Health Sciences Center

When a friend tells you she had a rough day, do you feel sandpaper under your fingers? The brain may be replaying sensory experiences to help understand common metaphors, new research suggests.

Linguists and psychologists have debated how much the parts of the brain that mediate direct sensory experience are involved in understanding metaphors. George Lakoff and Mark Johnson, in their landmark work "Metaphors we live by," pointed out that our daily language is full of metaphors, some of which are so familiar (like "rough day") that they may not seem especially novel or striking. They argued that metaphor comprehension is grounded in our sensory and motor experiences.

New brain imaging research reveals that a region of the brain important for sensing texture through touch, the parietal operculum, is also activated when someone listens to a sentence with a textural metaphor. The same region is not activated when a similar sentence expressing the meaning of the metaphor is heard.

The results were published online this week in the journal Brain & Language.

"We see that metaphors are engaging the areas of the cerebral cortex involved in sensory responses even though the metaphors are quite familiar," says senior author Krish Sathian, professor of neurology, rehabilitation medicine and psychology at Emory University. "This result illustrates how we draw upon sensory experiences to achieve understanding of metaphorical language."

Seven college students who volunteered for the study were asked to listen to sentences containing textural metaphors as well as sentences that were matched for meaning and structure, and to press a button as soon as they understood each sentence. Blood flow in their brains was monitored by functional magnetic resonance imaging. On average, response to a sentence containing a metaphor took slightly longer (0.84 vs 0.63 seconds).

In a previous study, the researchers had already mapped out, for each of these individuals, which parts of the students' brains were involved in processing actual textures by touch and sight. This allowed them to establish with confidence the link within the brain between metaphors involving texture and the sensory experience of texture itself.

"Interestingly, visual cortical regions were not activated by textural metaphors, which fits with other evidence for the primacy of touch in texture perception," says research associate Simon Lacey, the first author of the paper.

The researchers did not find metaphor-specific differences in cortical regions well known to be involved in generating and processing language, such as Broca's or Wernicke's areas. However, this result doesn't rule out a role for these regions in processing metaphors, Sathian says. Also, other neurologists have seen that injury to various areas of the brain can interfere with patients' understanding of metaphors.

"I don't think that there's only one area responsible for metaphor processing," Sathian says. "Actually, several recent lines of research indicate that engagement with abstract concepts is distributed around the brain."

"I think our research highlights the role of neural networks, rather than a single area of the brain, in these processes. What could be happening is that the brain is conducting an internal simulation as a way to understand the metaphor, and that's why the regions associated with touch get involved. This also demonstrates how complex processes involving symbols, such as appreciating a painting or understanding a metaphor, do not depend just on evolutionarily new parts of the brain, but also on adaptations of older parts of the brain."

Sathian's future plans include asking whether similar relationships exist for other senses, such as vision. The researchers also plan to probe whether magnetic stimulation of the brain in regions associated with sensory experience can interfere with understanding metaphors.

The research was supported by the National Institutes of Health and the National Science Foundation.

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Tuesday, February 7, 2012

African-Americans and the toll of AIDS

HIV-AIDS is the third leading cause of death among African-American men and women between the ages of 35 and 44. Today is National Black HIV/AIDS Awareness Day, which aims to lower that tragic statistic through education, testing, involvement and treatment of the disease.

African Americans face the most severe burden of HIV of all racial groups in the United States. They disproportionately represent both new infections and fatalities, says Drenna Waldrop-Valverde, an investigator with Emory's Center for AIDS Research, and a professor in the Nell Hodgson Woodruff School of Nursing.

"Unfortunately, in this country, race and socio-economic status are very closely tied together," says Waldrop-Valverde. She is conducting an NIH-funded study of the effects of health literacy on drug compliance in African Americans living with HIV-AIDS.

"Taking medications just as the doctor tells you to take them, day in and day out, can have a greater benefit on the health of those with HIV than nearly any other factor," Waldrop-Valverde says.

How is HIV/AIDS affecting your community? Click here to see an interactive AIDS map of the United States.

Chemist recalls history of AIDS drugs
AIDS: From a new disease to a leading killer

Monday, February 6, 2012

On the trail of black flies and river blindness

The parasite that causes river blindness, Onchocerca volvulus, is transmitted through the bite of the black fly. In the above photo, the parasite can be seen emerging from the antenna of a black fly. (Credit: U.S. Department of Agriculture.)

Onchocerciasis, better known as “river blindness,” is one of the leading causes of preventable blindness in the world. More than 18 million people suffer from river blindness, the vast majority of them in Africa.

The disease is caused by parasitic worms that are spread to humans through the bite of the black fly. The symptoms include itching so severe that those infected have been known to claw their skin off – or even commit suicide. The disease can also harden the eye tissue, leading to permanent blindness.

A documentary called “Dark Forest Black Fly” is tracking the efforts of the Carter Center and its partners to wipe out river blindness in Uganda. If successful, Uganda may become the model for eliminating river blindness Africa-wide. (Watch the film's trailer, below.)

The filmmakers and scientists involved will describe their on-the-ground experiences of this historic public health effort on Tuesday, February 7, at the Carter Center in Atlanta. The program will include exclusive footage from “Dark Forest Black Fly,” to be completed this year. Click here for details of the event.

And click here to visit the Science Scene, where you can learn about more great science events at Emory and in metro Atlanta.

Sunday, February 5, 2012

Brace yourself for tornado season

Downed trees at the Emory law school, following a 2011 windstorm.

The National Oceanic and Atmospheric Administration has designated February 6-10 Severe Weather Awareness Week for Georgia. Do you have a plan for what to do in case of severe winds or a tornado? If not, it’s time to get one. Click here for guidance from Emory’s Office of Critical Event Preparedness and Response.

Severe weather is common in Atlanta, where large trees make heavy winds especially dangerous. Last year, a windstorm took down 40 trees on the Emory campus alone.

Tornadoes have been reported throughout the year, but they are most likely to occur from March to May. Georgia lies within what is referred to as “Dixie Alley,” where tornado activity is on par with the better-known “Tornado Alley.” Tornadoes can spawn with very little warning. In Georgia, tornadoes are more likely to strike at night, tend to stay on the ground longer, and are often hard to see as they are wrapped in areas of rain and hail.

Below is video of a 2008 tornado as it approached downtown Atlanta.

Windstorm reshapes Atlanta forests

Friday, February 3, 2012

Chinese war secrets: Beyond 'Guns, Germs and Steel'

Emory historian Tonio Andrade explains why he wrote his latest book, “Lost Colony: The Untold Story of China’s First Great Victory over the West,” in this column for

"In 1997, Jared Diamond published his wonderful book, 'Guns, Germs, and Steel,' which asked why it was that some societies become rich and powerful and others don’t. His explanation was geographical—it depended on where those societies were located and what ecological resources they had available to them. Eurasians (that is the people of Europe and Asia) were unusually blessed just because of where they lived, and so they developed techniques and technologies that enabled them to expand around the world.

"It’s a great book, but it leaves open an important question: why did Europeans rather than other Eurasians become so powerful on the world stage in modern times—i.e., after around 1500? After all, Asians—most notably the Chinese—had been world leaders in science and technology for centuries. What accounted for the sudden leap in European power vis-à-vis Asia in recent centuries?

"Historians and sociologists have been vehemently debating this question, but with little progress.

"It seemed to me that one way to help answer it was to look at warfare between Europeans and Chinese. So I did. And the war that I describe in this book is a fascinating and exciting one. It really is an 'untold story'—the first ever major conflict between western European and Chinese forces, and the last one until the famous Opium War of the 1800s.

"The Chinese lost the Opium War. They won the Sino-Dutch War. Why? How? Technology, weather, and leadership."

Read the whole article in

Wednesday, February 1, 2012

Laura Finzi: A physicist's view of life

Physicist Laura Finzi runs one of a handful of labs using single-molecule techniques to study gene transcription.

By Carol Clark

Have you ever had to remove a tiny speck of glass from your foot with a pair of tweezers? Imagine if that speck of glass was microscopic.

Emory physicist Laura Finzi uses magnetic tweezers and minuscule metal beads to tug on individual DNA molecules. Her lab studies the mechanics of DNA transcription, the first step in the expression of a gene, a process that is partly regulated by the bending and uncoiling of DNA. Protein-mediated loops in DNA operate like genetic switches. Often, when a loop is closed, transcription is “off” and when the loop is open, transcription turns “on.” In other cases, the loops connect proteins to turn on transcription. Identifying the physical and mechanical parameters of this process could lead to a better understanding of the causes, and potential treatments, for many diseases.

A native of Italy, Finzi is married to Emory biophysicist David Dunlap who has his research group in the cell biology department. In the interview below, Finzi tells eScienceCommons about her Italian roots, and why she became a physicist.

What makes your lab unique?

We are one of only a handful of physics labs using single-molecule techniques to study DNA transcription, and we combine three of these methods in our studies: Tethered particle motion, magnetic tweezers and atomic-force microscopy. In TPM, when you see the tethered plastic microspheres wiggle and shake, it’s like seeing the molecular world in action. With a tethered magnetic bead, a pair of magnets over the microscope stage becomes a pair of tweezers that we can use to twist and stretch the DNA precisely. In AFM, we see the macromolecules like bumps on an atomically flat surface.

Another thing that makes my lab unique is the gender balance: Five women and three men.

What was it like growing up in Italy?

My mother was a pianist and my father was a harbor engineer. We lived in Ravenna and Trieste on the Adriatic Sea, and later in Bologna. I have two elder sisters. My father always said that we needed to get married. But he also said that we had to be well-educated and have jobs that made us independent. He combined a traditional and a modern view.

What inspired you to become a physicist?

My father really wished that we all would have become engineers, and both of my sisters did. But as the youngest, I thought that they would have always told me, “Listen to us, we have more experience,” so I was eager to strike out in another direction.

Before graduating from college, I met a brilliant biophysicist, Carlos Bustamante, now a member of the American National Academy of Science. He offered me a position in his lab as a graduate student. He had a charming personality and was full of enthusiasm. He was always throwing fascinating challenges at his students. He’s the reason I became a biophysicist.

How did you and David Dunlap meet?

We were both graduate students at the University of New Mexico. David was very different from anyone I’d seen before and impossible not to notice. He’s very tall and often had mismatched, brightly colored socks. Given an Italian sense of fashion, I could not help but notice his bizarre taste. He thinks out of the box, and is a very creative and happy person.

What do you like to do for fun?

I enjoy downhill skiing, it’s like a ballet, very elegant and gentle and harmonic. And I love the white of the snow and the scenery above the tree line. It’s enchanting.

I like sports in general and being in shape. It feels good. We live near campus and I either walk or ride my bike to work. David and I have two wonderful and smart teenagers. The four of us, and Spark the dog, go for hikes and canoeing.

Do you cook Italian?

Yes, we like to cook at home, and we prefer a Mediterranean diet. My chocolate salami, an Italian dessert, is well-appreciated by my colleagues at Emory.

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Epigenetics zeroes in on nature vs. nurture