The Peeps experiments: Science that never goes stale

It’s that time of year again: The sugary, squishy, neon-bright baby chicks and bunnies known as Peeps have reappeared and people are inexplicably eating them. Vox wrote a roundup of some of the best cultural phenomena concerning Peeps over the years. It included an excerpt from a classic Emory Report story from 1999, describing how Emory researchers Gary Falcon and James Zimring “performed perhaps the most exhaustive Peeps testing in human history," exploring the candies’ durability in the face of a variety of substances:

“To test Peep solubility, they began with simple tap water, then moved on to boiling water, then to acetone, sulfuric acid and sodium hydroxide, but were left dumbfounded by Peeps' apparent invulnerability to each.

“Then they tried Phenol, a protein-dissolving solvent lethal to humans in amounts as small as a single gram. Peeps proved mortal to such a substance — well, almost. One hour after plunging an unfortunate Peep into its grisly demise, all that remained in the beaker was a pair of brown carnauba wax eyes floating in a purple Phenol soup.”

Emory’s groundbreaking Peeps research lives on at peepresearch.org, including details of an investigation of the effects of smoking and alcohol on Peeps health and the medical miracle of separating quintuplet Peep siblings, conjoined at birth.

Small world, big impact: The Emory Global Health Institute

The Emory Global Health Institute helped fund a program in Haiti for those suffering from depression in communities ravaged by natural disaster and conflict. This photo, near the town of Hinche, was taken by Emory medical student Jesse Rappaport, one of the 2016 winners of the EGHI Global Health Student Photography Contest.

By Sylvia Wrobel
Emory Magazine 

The little boy died at home, without medical attention, before his fifth birthday. It happens to as many as one in five children in poor African and South Asian countries. The boy was deeply mourned, but never counted. His death was not noted in any registry. Except for a fever, no one had any idea why he died—information that might have been lifesaving for family members, or helped health officials recognize and address a widespread problem, or been the earliest indication of a smoldering epidemic.

In 2015, when the Bill and Melinda Gates Foundation wanted to learn why so many die young, they turned to the Emory Global Health Institute (EGHI) to lead the Child Health and Mortality Prevention and Surveillance Network (CHAMPS), designed to help high-child-mortality countries strengthen their capability to collect, analyze, interpret, and share data. Innovative methods include training local teams to visit families soon after a child dies,gathering information on symptoms and, with permission, taking small needle tissue biopsies, which when examined with specialized tools developed at the US Centers for Disease Control and Prevention (CDC) can identify the specific organisms causing illness and death.

“While we would think we have a pretty good idea of why children are dying—respiratory disease, enteric infections, fevers, and sepsis from different microorganisms—we don’t know those specific causes,” says Jeffrey Koplan, former director of the CDC and now Emory Vice President for Global Health and EGHI’s founding director. “There are a lot of different things that can cause respiratory failure. A lot of illnesses can lead to gastroenteritis and then death. The objective of this grant is to identify the specific causes of death so that we can develop programs to address them and save lives.”

CHAMPS is big: A $75 million investment for the first three years of a projected 20-year study, involving hundreds of partners at field sites and programmatic support from Emory, the CDC, and other Atlanta-based and international partners. But EGHI was created to serve as the mainframe for just such large-scale, long-term efforts—whether addressing high rates of maternal and childhood morbidity, understanding the spike of diabetes in developing nations, or increasing access to safe water.

Borders don’t mean much to infectious diseases, from shape-shifters like HIV and drug-resistant tuberculosis to sudden outbreaks like Ebola, SARS, or Zika. Chronic problems like diabetes and cardiovascular disease no longer belong primarily to richer, fatter nations but take an increasingly heavy toll on the economic stability, development, and even national security of developing nations, all with global impact.

Founded 10 years ago as the flagship program to expand Emory’s commitment to global health, EGHI is its own entity, university-wide, not part of any individual school. The organization is deliberately compact—a staff of ten, a cluster of offices, no big signs on the door. But its design—pragmatic, strategic, multidisciplinary, partner focused—gives it maximum flexibility in how to identify and tackle problems.

Read the whole article in Emory Magazine.

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How babies see faces: New fMRI methods open window into infants' minds

“We’ve provided the first neural evidence that our basic mechanisms for face and place recognition are in place in infancy and only a little weaker than that of adults,” says Emory psychologist Daniel Dilks.

By Carol Clark

The ancient philosophers Descartes, Aristotle and Plato are among those who have pondered variations on the question: How much of our brain and mind are we born with and how much comes from being in the world?

“It’s an age-old debate, and one that we’re still having because it’s one of the most difficult questions to answer,” says Emory psychologist Daniel Dilks. “You can’t do controlled experiments to fully test the question in humans because you would have to take away a person’s experiences.”

Modern-day techniques, such as functional magnetic resonance imaging, or fMRI, offer a window into neural activity. Subjects must remain perfectly still and alert during scanning, however, making it difficult to do experiments with very young children. As a result, most measurements of children’s neural activity only go back to age four, at the earliest.

Until now, that is. As a post-doctoral fellow at MIT, Dilks was part of a team that successfully scanned the brains of awake human infants using fMRI. The researchers wanted to learn whether infants used similar neural mechanisms as adults to visually distinguish specific types of input, such as faces and objects.

“Two thirds of the adult brain is involved in visual processing, so the origins of how we process visual stimuli is particularly important to understanding the brain and the mind,” Dilks says.

The researchers adapted fMRI technology to make it baby friendly. They built a special fMRI head coil – the receiving antenna of the scanner – that allows a subject to recline in what resembles an infant car seat. A mirror attached to the seat allows a baby to watch videos while in the scanner. The researchers also muffled the noise of the scanner.

Using this technology, and other modifications, they conducted fMRI experiments on babies just four to six months old. The babies watched movies of faces and places and other stimulus categories while in the scanner, as data was collected on their neural activity. Their responses were then compared to those of adults.

The results, published this year by Nature Communications, found that the visual cortex of the infants responded preferentially to the categories of faces and places, with a spatial organization similar to adults. The adult responses, however, were more sensitive.

“We’ve provided the first neural evidence that our basic mechanisms for face and place recognition are in place in infancy and only a little weaker than that of adults,” Dilks says.

The work adds to the growing evidence that babies do not come into the world as what the ancient philosophers referred to as tabular rasa, or blank slates.

“Thirty years ago, we thought that infants were basically little sponges, absorbing everything around them,” Dilks says. “We now know that babies are full of knowledge really early — and we’re learning that some of that knowledge is pretty complex. It’s a big paradigm shift.”

Dilks has brought the fMRI scanning technology for infants and children to Emory, where his lab will build on the research to learn more about the development of visual processing. One goal is to map the progression of the category-selective visual cortex from infancy to adulthood. In addition to adding to basic scientific knowledge, the research may one day have medical applications.

“We can’t fix most neurological problems right now, partly because we don’t know enough about the brain,” Dilks says. “By continuing to learn more about how the brain develops and functions normally, we may keep moving closer to being able to repair it when something goes wrong.”

Related:
Babies have logical reasoning before age one
Dogs process faces in specialized brain area, study reveals 
How babies use numbers, space and time

Primate-parasite network analyses show how germs jump from host to host

A juvenile bonobo leaps from a branch. The bonobo, a threatened species of great ape found in the Congo Basin, is the closest existing relative to humans, along with the chimpanzee.

By Carol Clark

An extensive review of research on wild primate social networks and parasites underscores the importance of super-spreaders, or central individuals that play an outsized role in transmission of a pathogen.

Trends in Parasitology published the review, the first comprehensive synthesis of environmental and theoretical studies of disease dynamics in wild primate species — most of which are now threatened with extinction.

“This review gives critical insights that are applicable not just to conservation, but to our understanding of emerging infectious diseases and human health,” says Thomas Gillespie, lead author of the review and a primate disease ecologist at Emory University. “We hope it helps jump-start a new way of approaching research into disease transmission – one that integrates ecology, behavior and evolution on a grand scale.”

About 60 percent of the more than 500 known primate species face an extinction threat and more than three-fourths of them are on the decline, due to loss of habitat, hunting and disease. Large chunks of the world’s forests are succumbing to agriculture, mining and logging, bringing people, primates, pets and livestock into closer proximity. That juxtaposition sets the stage for more pathogens to jump between humans and our closest relatives. More than 20 percent of wild primate species harbor parasites capable of spilling over into humans. HIV, Ebola, yellow fever and respiratory viruses are examples of viruses shared by humans and wild primates.

“How an emerging pathogen spreads through a species tends to be ‘a black box’ until it causes an outbreak among people,” Gillespie says. The Zika virus, for instance, was first identified in monkeys in Uganda in 1947 but was not widely studied until recently, after it started sweeping through human populations.

Wild chimpanzees in Uganda's Kibale National Park. Chimpanzees, another threatened species of great ape, share 96 percent of human DNA. (Photo by Julie Rushmore)

Traditional infectious disease models generally assume that all individuals within a population have an equal probability of receiving or giving an infection, but more powerful analytical tools are showing that is not the case.

“Especially during the last decade,” Gillespie says, “it’s become much clearer that, just as everything in natural systems is heterogeneous, so is disease transmission.”

The so-called 80-20 rule – 80 percent of disease transmission events in an epidemic are caused by 20 percent of individuals – is now a well-established phenomenon. What’s not yet as well-understood are all of the variations within a disease system, and how these variations can combine to make an individual a super-spreader.

“Primate-parasite networks are an ideal model system for studying these questions,” Gillespie says, “because primate species are so varied and they have sophisticated social structures. We also have behavioral data for many primates – detailing the hierarchical ranking of individuals, and whom those individuals are related to and whom they interact with – collected over decades of observational studies.”

Combining knowledge of behaviors by individual species with data on their parasites can help researchers sort out high-risk traits and identify super-spreaders that contribute to transmission in a predictable way. Such patterns can help researchers to develop targeted interventions.

The review cites the example of a vaccine under development for Ebola virus, which is designed to replicate and spread immunity from a few individuals to others in a population. Targeting the most central individuals in an ape group with such a vaccine may be an effective way to mitigate future Ebola-related ape die-offs and spillover events into human populations.

The review also lays out a vision for the next decade of research into pathogen transmission, one that integrates ecology, behavior and evolution for studies of wild primates, other wildlife and humans.

“In addition to looking at how sociality influences infection, this review highlights the need to understand more about the flip side of that question: How do pathogens affect behavior and shape sociality?” Gillespie says. “We want to get people thinking about questions like this, in parallel networks of species.”

Co-authors of the review include Julie Rushmore of Oregon State University and the University of Georgia, and Donal Bisanzio of the University of Oxford.

Related:
Experts warn of impending extinction of many of the world's primates
Zeroing in on super-spreaders, and other hidden patterns of epidemics

Brain scans of service-dog trainees help sort weaker recruits from the pack

Some of the service dog trainees that were involved in the study pose with an fMRI scanner. (Photo by Gregory Berns.)

By Carol Clark

Brain scans of canine candidates to assist people with disabilities can help predict which dogs will fail a rigorous service training program, a study by Emory University finds.

The journal Scientific Reports published the results of the study, involving 43 dogs who underwent service training at Canine Companions for Independence (CCI) in Santa Rosa, California.

“Data from functional magnetic resonance imaging (fMRI) provided a modest, but significant, improvement in the ability to identify dogs that were poor candidates,” says Emory neuroscientist Gregory Berns, who led the research. “What the brain imaging tells us is not just which dogs are more likely to fail, but why.”

All of the dogs in the study underwent a battery of behavioral tests showing that they had a calm temperament before being selected for training. Despite calm exteriors, however, some of the dogs showed higher activity in the amygdala – an area of the brain associated with excitability. These dogs were more likely to fail the training program.

“The brain scans may be like taking a dog’s mental temperature,” Berns says. “You could think of it as a medical test with a normal range for a service dog. And the heightened neural activity that we see in the amygdala of some dogs may be outside of that range, indicating an abnormal value for a successful service dog.”

The findings are important, he adds, since the cost of training a service dog ranges from $20,000 to $50,000. As many as 70 percent of the animals that start a six-to-nine-month training program have to be released for behavioral reasons.

“There are long waiting lists for service dogs, and the training is lengthy and expensive,” Berns says. “So the goal is to find more accurate ways to eliminate unsuitable dogs earlier in the process.

The study found that fMRI boosted the ability to identify dogs that would ultimately fail to 67 percent, up from about 47 percent without the use of fMRI.

“This type of approach is not going to be feasible for individual trainers and their dogs because of the expense of fMRI,” Berns says. “It would only be practical for organizations that train large numbers of dogs every year.”

CCI is a non-profit that breeds, raises and trains dogs to assist human partners. Its service dog program, designed for disabled people, provides dogs to do tasks such as turn on lights, pick up dropped keys, open a door and pull a manual wheelchair.

Golden retrievers, Labradors — or crosses between the two — are the usual CCI service dog breeds, due to their generally calm and affable natures. After the puppies are weaned, they are adopted by volunteer puppy raisers for 15 months, before returning to CCI to undergo behavioral tests. Those that pass begin training.

For the Scientific Reports paper, the researchers taught the dogs how to remain still while undergoing an fMRI at the start of the training program.

The Berns lab was the first to conduct fMRI experiments on awake, unrestrained dogs, as part of an ongoing project to understand canine cognition and inter-species communication. In an early experiment, dogs were trained to respond to hand signals. One signal meant the dog would receive a food treat, and another signal meant that the dog would not receive one. The caudate region of the brain, associated with rewards in humans, showed activation when the dogs saw the signal for the treat, but not for the non-treat signal.

The researchers adapted this experiment for the current study — the largest yet involving dogs undergoing fMRI. The dogs were taught hand signals for “treat” and “no treat,” but sometimes the signals were given by the dog’s trainer and other times by a stranger.

The results found that dogs with stronger activity in the caudate in response to the treat signal – regardless of who gave the signal – were slightly more likely to successfully complete the service dog training program. However, if a dog had relatively more activity in the amygdala in response to the treat signal – particularly if the signal was given by a stranger – that increased the likelihood that the dog would fail.

“The ideal service dog is one that is highly motivated, but also doesn’t get excessively excited or nervous,” Berns says. “The two neural regions that we focused on – the caudate and the amygdala – seem to distinguish those two traits. Our findings suggest that we may be able to pick up variations in these internal mental states before they get to the level of overt behaviors.”

Berns hopes that the technology may become more refined and have applications for a broader range of working dogs, such as those used to assist the military and police forces.

Co-authors of the study include Andrew Brooks and Mark Spivak from Dog Star Technologies in Sandy Springs, Georgia, and Kerinne Levy from CCI.

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What is your dog thinking? Brain scans unleash canine secrets
Dogs process faces in specialized brain area, study reveals