Can whales and dolphins adapt to oily Gulf?

The dead sperm whale found this week in the Gulf of Mexico puts the spotlight on how the BP oil spill will affect this endangered mammal, along with other cetaceans, such as dolphins, that must break the oil-slicked surface to breathe.

“These communities of whales and dolphins are already known to be stressed, because they’re dealing with other pollutants, like heavy metals, in the water,” says Emory neuroscientist Lori Marino, an expert in whale and dolphin intelligence and behaviors. “They are already compromised animals, and when they have something like this to deal with, it can be a tipping point for them.”

NASA satellite image, below, shows oil reaching Alabama beaches and the Florida panhandle. (Click on image to enlarge.)
It is unknown whether the deaths of the young sperm whale and the half-dozen dolphins that have been found washed up on Gulf beaches are oil related. Unlike the stark visual evidence of birds with oil-coated feathers, the toxic impact on whales and dolphins is primarily internal.

“They have to open their blowholes to breathe,” Marino says. “Imagine sticking your nose in a bowl and snorting oil. You’d be choking.”

A greater, and more lasting, impact may be the domino effect of toxins in the food chain, as oil droplets get into the fish and squid that cetaceans eat, she says.

Recent reports of large numbers of dolphins moving into shallow waters off Florida to flee the oil are troubling, Marino adds. “If they stay in the shallows and the oil comes in after them, they’ll be trapped.”

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Bringing new blood to high school science

Murder or a grisly accident? Psychology grad student Sabrina Sidaras (on floor) helps high school students learn to think like scientists. Photo by Tiffany Smith.

Want to get the attention of 11th grade chemistry students on the first day of class? Then ask them to investigate a suspicious death in the lab. Set the scene, including yellow police tape, broken vials of chemicals, fake blood and a “corpse” splayed on the floor.

“The first time I did it, I broke a smile,” says Sabrina Sidaras, an Emory psychology graduate student who played dead at Cedar Grove High School. “I didn’t realize how funny the students would be.”

Sidaras joined forces with Cedar Grove science teacher Tiffany Smith last Spring for PRISM, a collaboration of Emory and Atlanta area schools. The program pairs Emory graduate students with middle school and high school teachers to develop and implement problem-based learning (PBL) and other innovative teaching techniques into science classrooms.

In the case of the body on the lab floor, the students have to deduce what killed the victim by observing the evidence. “The students love it,” Sidaras says. “They’re used to coming in a class and sitting down, but this presents them with a whole different experience. They get excited, talking to each other about what may have happened and doing an investigation.”

Click on comic to enlarge:
Neuroscience graduate student Kate O'Toole created a comic strip to introduce teens to her research of ion channels.

PBL lesson plans developed by PRISM have gripping names, like “Dial M for Molecule,” “Adding Fuel to the Fire,” “Fatal Attraction,” “Sealed with a Kiss” and “Got Gas?”

PRISM aims to first get the students interested, then help them learn the science and understand how it applies to real life. “I think it really opens their eyes,” Sidaras says.

The experience changed her perspective as well. Instead of following a traditional career path in academia, Sidaras now hopes to get a job developing high school science curriculums.

Qing Shao, a graduate student in biophysics, was paired with David Wetty, who teaches 10th-grade physics at South Atlanta High School. “He’s very dynamic, and he helped me become a better communicator,” Shao says. “I learned to be patient, and to explain things in a way that everyone can understand.”

When a student who used to sleep at the back of the class started paying attention, she knew she’d made a breakthrough. “He was actually very smart,” she says.
Tenth-grade students turned the periodic table into a rap song and video. Click here to see it.

PRISM lessons, which can involve anything from Spiderman to rap music, were a big culture shock for Shao, a native of China. “In China, you can have 70 students in a class,” she says. “Everybody is very quiet and never moves. The teacher writes things on the board and the students take notes.”

She says she enjoyed PRISM and problem-based learning as much as the high school kids. “In the future, if I get a chance to contribute something, maybe I can bring some PBL to China,” she says. “It’s really very fun.”

About 100 Emory students have participated in PRISM since the program began in 2003 through a National Science Foundation grant. Emory is applying for additional funds to expand the program, with a focus on teaching evolution.

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Sewage raises West Nile virus risk

More than 700 U.S. cities have combined sewer overflows, allowing wastewater to flow into urban waterways with minimal treatment. Video of an Atlanta CSO stream by Gonzalo Vazquez-Prokopec.

Sewage that overflows into urban creeks and streams during periods of heavy rain can promote the spread of West Nile virus, an Emory study finds.

The analysis of six years of data showed that people living near creeks with sewage overflows in lower-income neighborhoods of Southeast Atlanta had a seven times higher risk for West Nile virus than the rest of the city.

“The infection rate for mosquitoes, birds and humans is strongly associated with their proximity to a creek impacted by sewage,” says Gonzalo Vazquez-Prokopec, the Emory disease ecologist who led the study. “And if the creek is in a low-income neighborhood, we found that the entire cycle of infection is even higher.”

More affluent residents are more likely to have air-conditioning and use insect repellant and other protective measures, the researchers theorized.
Red outline shows Atlanta boundary: Click on graph to enlarge.

The study, to be published by Environmental Health Perspectives, was a collaboration of Emory, the Centers for Disease Control and Prevention, the Georgia Division of Public Health, the Fulton County Department of Health and Wellness, the National Institutes of Health, the Fogarty International Center and the University of Georgia.

According to the Environmental Protection Agency, about 850 billion gallons per year of untreated mixed wastewater and storm water are discharged into U.S. urban waters, mainly through combined sewer overflow (CSO) systems that are used in more than 700 cities. Under normal conditions, CSO systems channel wastewater to a treatment plant before it is discharged into a waterway. During periods of heavy rain or snowmelt, however, the wastewater flows directly into natural waterways after only minimal chlorine treatment and sieving to remove large physical contaminants.
Photos of Atlanta CSO streams, above and below, by Gonzalo Vazquez-Prokopec.

Most of the available data on the human health impacts of sewage-affected waterways focuses on the effects of exposures to bacteria, heavy metals, hormones and other pollutants.

Previous research by Emory’s Department of Environmental Studies has shown that the Culex mosquito – a vector for West Nile virus and other human pathogens – thrives in Atlanta streams contaminated with CSO discharges. The mosquitoes become more populous, breed faster and grow larger than those found in cleaner waters.

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“We wanted to know if the CSOs also raised the risk of getting infected with West Nile Virus,” said Uriel Kitron, chair of environmental studies and a co-author of the study.

An expert in geographic information systems (GIS) technology, Vazquez-Prokopec did a spatial analysis integrating the geographic coordinates of each CSO facility and associated streams, and six years of surveillance data on mosquito abundance and West Nile virus infections in mosquitoes, humans, blue jays and crows. (These birds are considered sentinels for the disease, due to their high West Nile Virus mortality and their proximity to humans.)

During 2001-2007, Georgia reported 199 human West Nile virus infections and 17 deaths. About 25 percent of the cases resided in Fulton County. The county forms the core of metropolitan Atlanta, and encompasses a range of socio-economic conditions, from the wealthiest neighborhoods in the state to those with the highest poverty rates in the country.

The analysis found that mosquitoes and birds near all seven of the CSO facilities and associated streams of Atlanta had significantly higher rates of West Nile virus infection than those near urban creeks not affected by CSOs. Humans residing near CSO streams also had a higher rate of infection if they lived in a low-income neighborhood with a greater proportion of tree canopy cover and homes built during the 1950s-60s. Residents of a wealthy northern Fulton County area did not experience an increase in West Nile virus cases, despite their proximity to two CSO streams.

In 2008, Atlanta completed an underground reservoir system designed to reduce the size and the number of CSOs. “In terms of mosquitoes, however, this remediation has the potential to make things worse instead of better by releasing slower flows of nutrient-rich effluent into streams,” Vazquez-Prokopec notes.

Emory scientists and public health officials are continuing to study West Nile virus and CSOs in Atlanta urban streams. Their goal is to help identify effective measures to limit the spread of the disease.

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Hugs go way back in evolution

Charles Q. Choi writes in Scientific American: Chimpanzees may comfort others in distress in ways very similar to how people do, according to what may be the largest study of consolation in animals by far. The new findings in our closest living relatives could help shed light on the roots of empathy in humans. ...

To better understand how empathy might have evolved in our lineage, animal behaviorist Teresa Romero of Emory University and her colleagues studied roughly 30 chimpanzees housed outdoors at the Yerkes National Primate Research Center. Over a span of eight years they documented cases where uninvolved bystanders offered comfort to recent victims of aggression. Whereas most studies on animal consolation typically involve looking into a few hundred cases of conflicts and their aftermaths, "ours is based on an analysis of about 3,000 cases," Romero says.

Read the full Scientific American article, and see the full details about the Emory study in the Proceedings of the National Academy of Sciences.

Photo, above, by Frans de Waal shows a young chimpanzee consoling an adult male that just lost a fight.

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How babies use number, space and time

A 9-month-old can make intuitive leaps across quantitative concepts, says Stella Lourenco, shown in her lab with research participant Beckett Ford. Photo by Kay Hinton.

By Carol Clark

Even before they learn to speak, babies are organizing information about numbers, space and time in more complex ways than previously realized, a study led by Emory University psychologist Stella Lourenco finds.

“We’ve shown that 9-month-olds are sensitive to ‘more than’ or ‘less than’ relations across the number, size and duration of objects. And what’s really remarkable is they only need experience with one of these quantitative concepts in order to guess what the other quantities should look like,” Lourenco says.

Lourenco collaborated with neuroscientist Matthew Longo of University College London for the study, to be published in an upcoming issue of Psychological Science.

In his 1890 masterwork, “The Principles of Psychology,” William James described the baby’s impression of the world as “one great blooming, buzzing confusion.” Accumulating evidence is turning that long-held theory on its head.

“Our findings indicate that humans use information about quantity to organize their experience of the world from the first few months of life,” Lourenco says. “Quantity appears to be a powerful tool for making predictions about how objects should behave.”

Lourenco focuses on the development of spatial perception, and how it interfaces with other cognitive dimensions, such as numerical processing and the perception of time. Previous research suggests that these different cognitive domains are deeply connected at a neural level. Tests show, for instance, that adults associate smaller numbers with the left side of space and larger numbers with the right.

“It’s like we have a ruler in our heads,” Lourenco says of the phenomenon.

Other tests show that when adults are asked to quickly select the higher of two numbers, the task becomes much harder if the higher number is represented as physically smaller than the lower number."It's like we have a ruler in our heads," Lourenco says. Photo by Carol Clark.

Lourenco wanted to explore whether our brains just pick up on statistical regularities through repeated experience and language associations, or whether a generalized system of magnitude is present early in life.

Her lab designed a study that showed groups of objects on a computer screen to 9-month-old infants. “Babies like to stare when they see something new,” Lourenco explains, “and we can measure the length of time that they look at these things to understand how they process information.”

When the infants were shown images of larger objects that were black with stripes and smaller objects that were white with dots, they then expected the same color-pattern mapping for more-and-less comparisons of number and duration. For instance, if the more numerous objects were white with dots, the babies would stare at the image longer than if the objects were black with stripes.

“When the babies look longer, that suggests that they are surprised by the violation of congruency,” Lourenco says. “They appear to expect these different dimensions to correlate in the world.”


The findings suggest that humans may be born with a generalized system of magnitude. “If we are not born with this system, it appears that it develops very quickly,” Lourenco says. “Either way, I think it’s amazing how we use quantity information to make sense of the world.”

Lourenco recently received a grant of $300,000 from the John Merck Fund, for young investors doing cognitive or biological science with implications for developmental disabilities. She plans to use it to further study how this system for processing quantitative information develops, both normally and in an atypical situation such as the learning disorder known as dyscalculia – the mathematical counterpart to dyslexia.

“Dyslexia has gotten a great deal of attention during the past couple of decades,” Lourenco says. “But as our world keeps getting more technical, and students in the United States lag other countries in math, more attention is being paid to the need to reason about numbers, space and time. I’d like to explore the underlying causes of dyscalculia and maybe get a handle on how to intervene with children who have difficulty engaging in quantitative reasoning.”

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