Following the people and events that make up the research community at Duke

Category: Guest Post Page 1 of 12

Why Ruffed Lemurs (and Their Gut Microbes) Need to Eat Greens

We offered fruit-eating ruffed lemurs at the Duke Lemur Center fresh lettuce each afternoon for 10 days. They happily ate it and their gut microbiomes shifted, suggesting that leafy greens could be incorporated into the lemurs’ standard dietary regimen to boost foraging opportunity and fiber intake.

Red-ruffed lemurs and black-and-white ruffed lemurs are some of Madagascar’s most iconic wildlife. Sporting a long snout and a neck ruff to rival those of the Elizabethan court, these primates naturally live in the rainforests, where they mostly eat fruits and flowers, and make their living as seed dispersers and pollinators.

Ruffed lemurs really like romaine lettuce and their gut bugs do too! (Lydia Greene)

Ruffed lemurs also live in zoos worldwide, where they are given fruit-rich diets to match those foraged by their wild peers. But scientists are starting to realize that the fruit eaten by wild lemurs is quite different from the domesticated fruit provided at zoos. Wild fruits are seedy, pulpy, and thick-skinned, whereas orchard fruits are fleshy, plump, and sweet. From a nutritional standpoint, wild fruits contain more fiber, whereas orchard fruits contain more sugar. 

Our team wondered if a fiber boost might benefit Duke’s ruffed lemur colony. But would these fruit-loving lemurs eat their veggies?  

Cue the salad bar.

To test this idea, we offered ruffed lemurs at the Duke Lemur Center a lot of lettuce. Lettuce seemed like a pretty palatable way to stimulate foraging behavior, while boosting fiber intake.

With help from the research department, we offered 19 ruffed lemurs 150-200 grams of romaine lettuce each day, which is about double the weight of their standard diet. We repeated this regimen every day for 10 days, while recording the lemurs’ feeding behavior and collecting fecal samples for gut microbiome analysis. Because gut microbes are chiefly responsible for converting plant fiber into energy for the lemurs, measuring changes to the lemurs’ microbiomes offered a way to ‘see’ the impact of lettuce consumption.

It turns out that ruffed lemurs really like lettuce. They consistently ate lettuce every day and showed no decline in consumption across the study. Younger animals ate more lettuce than did geriatric lemurs, but all lemurs spent more time crunching on lettuce stalks than the leaves.

And their gut microbiomes responded. We noted two microbes that were more abundant on the lettuce diet: a known fiber digester from the Ruminococcaceae family, and a microbe known for its positive association with host health in other animals called Akkermansia.

Despite their classification as fruit eaters, ruffed lemurs readily eat lettuce. We think lettuce can be used to extend the lemurs’ foraging time while boosting dietary fiber. And it might just help replicate the lifestyles experienced by wild ruffed lemurs in their native Malagasy rainforests.     At the Duke Lemur Center, lettuce is now a routine item offered to ruffed lemurs (and other species too!). Next time you come out for a tour (once it’s safe to do so), you might get to see them crunching away on their new favorite snack!

( Read our paper here: https://onlinelibrary.wiley.com/doi/abs/10.1002/zoo.21555 )

Guest Post by Lydia Greene Ph.D., an NSF-sponsored postdoctoral fellow in biology working at the Duke Lemur Center.

Saving Africa’s Biggest Trees to Help Earth Breathe

Like wine, cheese, and savvy financial investments, many tropical trees become more valuable with age. This is particularly true when it comes to carbon storage, because old trees are often the biggest trees and the larger the tree, the more carbon it stores.

The value of big, old trees in combating climate change was underscored in a recent study of Gabon’s forests, led by the Nicholas School of the Environment’s John Poulsen. The team’s striking finding — that half of Gabon’s wealth of carbon is found in the largest 5% of trees — has implications that reach far beyond the sparsely populated Central African country’s borders.

Nicholas School Ph.D. student Graden Froese admires a forest giant in Ivindo National Park, Gabon.

Tropical forests play a key role in the global carbon cycle by keeping carbon out of the atmosphere. Trees take in CO2 — one of the infamous, heat-trapping greenhouse gases — during photosynthesis and use the carbon to grow, making new leaves, thicker and taller trunks, and more expansive root systems.

Scientists can estimate how much carbon a tree holds by measuring its trunk. So, like rainforest tailors, trained technicians traveled to all corners of the country to measure the girth and height of tens of thousands of trees.

This extraordinary two-year long effort was one of the first nationwide forest inventories in the tropics, making Gabon a leader in comprehensive forest monitoring.

John Poulsen is an associate professor of tropical ecology.

Poulsen and collaborators used the tree measurements to estimate the amount of carbon stored in Gabon’s forests and to determine why some forests hold more carbon than others.

“The field techs deserve all the credit”, Poulsen explained, “as they often walked for days through thick forest, traversing swamps and enduring humid, buggy conditions to measure trees. We turned their sweat and toil into information that could be used by Gabon’s government to prioritize areas for conservation.”

Who needs ladders, when you have colleagues? The field team collaborates to measure a forest giant.

The team analyzed a suite of environmental factors to see their effects on carbon storage. Of the natural factors, only soil fertility had a noticeable positive effect on tree biomass. Much more important was the impact of humans. As human activities such as agriculture and logging tend to target large trees, more heavily human-disturbed forests had a much different structure than pristine forests. The farther a study area was from human settlements, the more likely it was to host large trees and consequently, higher amounts of carbon.

The paper notes that Gabon stands out as a country with “one of the highest densities of aboveground forest carbon.” In fact, Gabon’s undisturbed forests store more carbon than those in the Amazon, which have been referred to as the lungs of the planet.

According to Poulsen, “Gabon is the second most forested country in the world with 87% forest cover, a deforestation rate near zero…” Because of its impressive forest cover and its location straddling the equator, Gabon’s forests host an incredibly diverse array of plants and animals, including many threatened and endangered species. Rural communities depend on these forests for their livelihoods.

Unfortunately, even Gabon’s ‘small’ trees make for spectacular felled logs.

However, Gabon’s impressive forests are valuable to more than just wildlife, climate researchers, and local communities. The logging industry also sees these forests as a chance for profit. More than half (about 67%) of Gabon’s forests are under contract with logging companies to harvest timber, putting them at risk of losing many of their carbon-storing giants.

Poulsen’s study highlights the importance of a more nuanced approach to forest conservation in Gabon. One that doesn’t simply focus on stopping deforestation or promoting restoration, as is prescribed in many international climate change plans, but an approach that recognizes the necessity of preserving high conservation value, old growth forests.

Anna Nordseth

Guest Post by Anna Nordseth, a graduate student in the Nicholas School of the Environment.

Following In The Footsteps of Elephants

Imagine for a moment that you’re 6,000 pounds, living in one of the wildest places on Earth, with no schedule, nowhere to be. How do you decide where to spend your time? Where to go next? Do you move where food is most plentiful? Is water your main priority?

Amelia Meier in the field.

These are some of the questions addressed by Duke Ph.D. candidate Amelia Meier and former postdoctoral researcher Dr. Chris Beirne in Dr. John Poulsen’s lab. Their recent study published in Trends in Ecology and Evolution focused on the African forest elephant–the slightly smaller yet still undeniably huge cousin of the savanna elephant.  

The team wanted to know what influences certain aspects of elephant behavior. Specifically, how much climate and resource availability drives elephant movement and influences their diet. To do this, the team looked at fruit abundance (a high-energy staple of elephants’ diets), water availability from rainfall, and elephant identity and how those factors affect how an individual moves and eats.

One might think that such a massive animal is easy to spot in the forest. However, the dense vegetation of Central African rainforests can be an impenetrable wall, allowing the massive animals to move unseen through the forest, leaving broken branches and steaming dung piles in their wake.

To better track them, the researchers fitted individual elephants with GPS collars that turn an iPhone into an elephant-tracking tool. This also allowed trackers to follow the elephants at a distance and avoid conflict with the sometimes temperamental animals.

Collared elephant, Marijo, (left) enjoying the rich minerals found at the Langoue Bai forest clearing.

Meier, Beirne, and colleagues also wanted to know more about the diets of the tracked elephants to see if what they ate changed with how much fruit is available. This less-than-glamorous job was done by dissecting fresh dung piles, estimating the proportions of leafy and woody material, and counting the number of seeds in each one.

Tropical rainforests are lush, yet have patchy resources, making it important for many frugivores to have flexible diets. Some trees only produce fruit in the wet season. Others fruit every other year. To gauge fruit availability, the research team conducted “fruit-walks” at the beginning and end of each day of following an elephant, in which trackers counted all of the ripe fruit on the ground.

A key finding of the study was that the most important factor driving movement was an elephant’s individuality; some respond to food or water availability differently and some simply move around more than others.

Field researcher Marius Edang getting the straight poop on elephant diets.

Interestingly, elephants appear to be affected by resources differently depending on the timescale the authors looked at. Water was important on both a day-to-day and month-to-month basis. Yet on a daily basis, fruit and water were more equally matched, with water still maintaining a slight lead.

Fruit availability was also critical in determining how much elephants moved and what they ate. When there was more fruit available, the elephants ate more fruit, as evidenced by the proportion of seeds in dissected dung piles.

Aside from being an awe-inspiring species, forest elephants are important to the health of their native ecosystems. They are unwitting gardeners, planting seeds of the fruits they consume in piles of dung and giving those seeds a better chance of survival. That’s part of why understanding what motivates forest elephant movement is more than the satisfaction of an elephant enthusiast’s curiosity; it is critical to managing and conserving a species that is vulnerable to multiple threats from humans.

Meier’s dissertation research focuses on elephant social behavior and the effects of human disturbance on elephant social groups, allowing her to pursue her long-term interest in animal behavior with a practical conservation application.

“I was living in Congo and I knew I wanted to keep working in the region. There, you have elephants–this amazing, highly intelligent, social species that is surrounded by conflict.”

Poachers seek elephants for their ivory tusks, which are valuable on the black market. The pachyderms are also prone to conflict with humans when they start foraging in village plantations, destroying crops and damaging livelihoods.

The team’s findings open the way for new questions about why different elephants exhibit different patterns of movement. What underlying factors affect behavior, and why? Does it have to do with age? Sex? Their social environment?

These questions remain unanswered for now, but the work of Meier and colleagues represents a critical step in understanding elephant behavior to improve forest elephant management and conservation strategies.

Guest Post by Anna Nordseth, a Ph.D. Candidate in the Nicholas School of the Environment

Duke Scientists Studying the Shape of COVID Things to Come

The novel coronavirus pandemic has now resulted in more than 3 million confirmed cases globally and is pushing scientists to share ideas quickly and figure out the best ways to collaborate and contribute to solutions.

SARS-CoV-2 surface proteins illustrated by We Are Covert, via Wikimedia Commons

Recently, Duke researchers across the School of Medicine came together for an online symposium consisting of several short presentations to summarize the latest of what is known about the novel coronavirus, SARS-CoV-2.

This daylong event was organized by faculty in the Department of Molecular Genetics and Microbiology and researchers from different fields to share what they know about the virus and immunity to guide vaccine design. This conference highlighted the myriad new research pathways that Duke researchers are launching to better understand this pandemic virus.

One neat area of research is understanding viral processes within cells to identify steps at which antivirals may block the virus. Stacy Horner’s Laboratory studies how RNA viruses replicate inside human cells. By figuring out how viruses and cells interact at the molecular level, Horner can inform development of antivirals and strategies to block viral replication. Antivirals stop infections by preventing the virus from generating more of copies of itself and spreading to other cells. This controls damage to our cells and allows the immune system to catch up and clear the infection.

At the symposium, Horner explained how the SARS-CoV viral genome consists of 29,891 ribonucleotides, which are the building blocks of the RNA strand. The viral genome contains 14 areas where the RNA code can be transcribed into shorter RNA sequences for viral protein production. Though each RNA transcript generally contains the code for a single protein, this virus is intriguing in that it uses RNA tricks to code for up to 27 proteins. Horner highlighted two interesting ways that SARS-CoV packs in additional proteins to produce all the necessary components for its replication and assembly into new viral progeny.

The first way is through slippery sequences on the RNA genome of the virus. A ribosome is a machine inside the cell that runs along a string of RNA to translate its code into proteins that have various functions. Each set of 3 ribonucleotides forms one amino acid, a building block of proteins. In turn, a string of amino acids assembles into a distinct structure that gives rise to a functional protein.

One way that SARS-CoV-2 packs in additional proteins is with regions of its RNA genome that make the ribosome machinery slip back by one ribonucleotide. Once the ribosome gets offset it reads a new grouping of 3 ribonucleotides and creates a different amino acid for the same RNA sequence. In this way, SARS-CoV-2 makes multiple proteins from the same piece of RNA and maximizes space on its genome for additional viral proteins.

An example of an RNA ‘hairpin’ structure, which might fool a ribosome to jump across the sequence rather than reading around the little cul de sac. (Ben Moore, via Wikimedia Commons)

Secondly, the RNA genome of SARS-CoV-2 has regions where the single strand of RNA twists over itself and connects with another segment of RNA farther along the code to form a new protein. These folds create structures that look like diverse trees made of repetitive hairpin-like shapes. If the ribosome runs into a fold, it can hop from one spot in the RNA to another disjoint piece and attach a new string of amino acids instead of the ones directly ahead of it on the linear RNA sequence. This is another way the SARS-CoV-2 packs in extra proteins with the same piece of RNA.

Horner said a step-by-step understanding of what the virus needs to survive at each step of its replication cycle will allow us to design molecules that are able to block these crucial steps.

Indeed, shapes of molecules can determine their function inside the cell. Three Duke teams are pursuing detailed investigation of SARS-CoV-2 protein structures that might guide development of complementarily shaped molecules that can serve as drugs by interfering with viral processes inside cells.

Some Duke faculty who participated in the virtual viral conference. (L-R from, top) Stacy Horner, Nick Heaton, Micah Luftig, Sallie Permar, Ed Miao and Georgia Tomaras. (image: Tulika Singh)

For example the laboratory of Hashim Al-Hashimi, develops computational models to predict the diversity of structures produced by these tree-like RNA folds to identify possible targets for new therapeutics. Currently, the Laboratories of Nicholas Heaton and Claire Smith are teaming up to identify novel restriction factors inside cells that can stop SARS-CoV-2.

However, it is not just the structures of viral components expressed inside the cells that matter, but also those on the outside of a virus particle. In Latin, corona means a crown or garland, and coronaviruses have been named for their distinctive crown-like spikes that envelop each virus particle. The viral protein that forms this corona is aptly named the “Spike” protein.

This Spike protein on the viral surface connects with a human cell surface protein (Angiotensin-converting enzyme 2, abbreviated as ACE2) to allow the virus to enter our cells and cause an infection. Heaton proposed that molecules designed to block this contact, by blocking either the human cell surface protein or the viral Spike protein, should also be tested as possible therapies.

One promising type of molecule to block this interaction is an antibody. Antibodies are “Y” shaped molecules that are developed as part of the immune response in the body by the second week of coronavirus infection. These molecules can detect viral proteins, bind with them, and prevent viruses from entering cells. Unlike several other components on our immune defense, antibodies are shaped to specifically latch on to one type of virus. Teams of scientists at Duke led by Dr. Sallie Permar, Dr. Georgia Tomaras, and Dr. Genevieve Fouda are working to characterize this antibody response to SARS-CoV-2 infection and identify the types of antibodies that confer protection.

Infectious disease specialist Dr. Chris Woods is leading an effort to test whether plasma with antibodies from people who have recovered can prevent severe coronavirus disease in acutely infected patients.

Indeed, there are several intriguing research questions to resolve in the months ahead. Duke scientists are forging new plans for research and actively launching new projects to unravel the mysteries of SARS-CoV-2. With Duke laboratory scientists rolling up their sleeves and gowning up to conduct research on the novel coronavirus, there will be soon be many more vaccine and therapeutic interventions to test.

Guest post by Tulika Singh, MPH, PhD Candidate in the Department of Molecular Genetics and Microbiology (T: @Singh_Tulika)

Students Dance Their Way Out of “AI Bias”

Martin Brooke is no ordinary Engineering professor at Duke University. He teaches computer scientists, engineers, and technology nerds how to dance.

Brooke co-teaches Performance and Technology, an interactive course where students create performance projects and discuss theoretical and historical implications of technologies in performance. In a unique partnership with Thomas DeFrantz, a professor of African and African American Studies and Dance students will design a technology based on “heart,” for example, in order to understand how human expression is embedded in technology. Two weeks later, they’ll interact with motion-sensing, robotic trees that give hugs; and 3D printed hearts that detect colors and match people, sort of like a robotic tinder.

Thomas DeFrantz (left) and Martin Brooke  watch their students perform in the Performance and Technology course .

Brooke loves that this class is fun and interactive, but more importantly he loves that this class teaches students how to consider people’s emotions, facial expressions, cultural differences, cultural similarities and interactions when designing new technologies.

Human interface is when a computerized program or device takes input from humans — like an image of a face — and gives an output — like unlocking a phone. In order for these devices to understand human interface, the programmer must first understand how humans express themselves. This means that scientists, programmers, and engineers need to understand a particular school of learning: the humanities. “There are very, very few scientists who do human interface research,” Brooke said.

The students designed a robotic “Tinder” that changes colors when it detects a match.

Brooke also mentioned the importance of understanding human expressions and interactions in order to limit computer bias. Computer bias occurs when a programmer’s prejudiced opinions of others are transferred into the computer products they design. For example, many recent studies have proven that facial recognition software inaccurately identifies black individuals when searching for suspects of a criminal case.

“It turns out one of the biggest problems with technology today is human interface,” Brooke said. “Microsoft found out that they had a motion sensitive Artificial Intelligence that tended to say women, [more often than men], were angry.”  Brooke said he didn’t consider the importance of incorporating the arts and humanities into engineering before coming to Duke. He suggested that it can be uncomfortable for some scientists to think and express themselves artistically. “[When] technologists [take Performance and Technology], for example, they are terrified of the performance aspects of it. We have some video of a guy saying, ‘I didn’t realize I was going to have to perform.’ Yeah, that’s what we were actually quite worried about, but in the end, he’s there in the video, doing slow motion running on stage — fully involved, actually performing, and really enjoying it.

Duke has a strong initiative to promote arts and humanities inclusion in science, technology, engineering, and mathematics. Brooke plans to bring Bass Connections, a research program that focuses on public outreach and cross-disciplinary work, to his Performance and Technology class before the end of the semester to demonstrate bias through a program he calls AI Bias In the Age of a Technical Elite.  

“You give it someone’s name and it will come up with a movie title, their role, and a synopsis of the movie,” Brooke said. “When I put in my name, which is an English name, it said that the movie I would be in is about a little boy who lives in the English countryside who turns into a monster and terrorizes the town.” This program shows even something as simple as a name can have so much stigma attached to it.

Bass Connections Students working on technology and engineering projects. (From the official Duke page for Bass Connections.)

Brooke’s hope is that his class teaches students to think about technology and human interface. “Hopefully that’s a real benefit to them when they get out actually designing products.”

Guest post by Jordan Anderson, a masters student in Science & Society

Teens Have the Feels About Their Family’s Standing

A study of British twins appearing this week in the Proceedings of the National Academy of Sciences shows that an adolescent’s sense of their own family’s social and economic standing is closely linked to that child’s physical and cognitive health.

In fact, the adolescent’s perception of status was a more powerful predictor of their well-being and readiness for further education than their family’s actual status. The study sample represented the full range of socioeconomic conditions in the U.K.

“Testing how young people’s perceptions related to well-being among twins provided a rare opportunity to control for poverty status as well as environmental and genetic factors shared by children within the same family,” said lead author Joshua Rivenbark, an MD/PhD student in Duke’s Medical School and Sanford School of Public Policy.

Joshua Rivenbark is an MD/PhD student in medicine and policy

“Siblings grew up with equal access to objective resources, but many differed in where they placed their family on the social ladder – which then signaled how well each twin was doing,” Rivenbark said.

Researchers followed 2,232 same-sex twins born in England and Wales in 1994-95 who were part of the Environmental Risk (E-Risk) Longitudinal Twin Study based at King’s College London. Adolescents assessed their family’s social ranking at ages 12 and 18. By late adolescence, these beliefs signaled how well the teen was doing, independent of the family’s access to financial resources, healthcare, adequate nutrition and educational opportunities. This pattern was not seen at age 12.

“The amount of financial resources children have access to is one of the most reliable predictors of their health and life chances,” said Candice Odgers, a professor of psychological science at the University of California, Irvine, who is the senior author of the report. “But these findings show that how young people see their family’s place in a hierarchical system also matters. Their perceptions of social status were an equally good, and often stronger, indicator of how well they were going to do with respect to mental health and social outcomes.”

Study findings also showed that despite growing up in the same family, the twins’ views were not always identical. By age 18, the twin who rated the family’s standing as higher was less likely to be convicted of a crime; was more often educated, employed or in training; and had fewer mental health problems than his or her sibling.

“Studies that experimentally manipulate how young people see their social position would be needed to sort out cause from effect,” Rivenbark said.

The E-Risk study was founded and is co-directed by Duke professors Avshalom Caspi and Terrie Moffitt at King’s College London.

Guest Post by Pat Harriman, UC-Irvine News @UCIPat

Inventing New Ways to Do Brain Surgery

This is the sixth and final 2019 post written by students at the North Carolina School of Science and Math as part of an elective about science communication with Dean Amy Sheck.

Dr. Patrick Codd is the Director of the Duke Brain Tool Laboratory and an Assistant Professor of Neurosurgery at Duke. Working as a neurosurgeon and helping with the research and development of various neurosurgical devices is “a delicate balance,” he said.

Patrick Codd

Codd currently runs a minimally invasive neurosurgery group. However, at Massachusetts General Hospital, he used to run the trauma section. When asked about which role was more stressful, he stated “they were both pretty stressful” but for different reasons. At Mass General, he was on call for most hours of the day and had to pull long shifts in the operating room. At Duke, he has to juggle surgery, teaching, and research and the development of new technology.

“I didn’t know I was going to be a neurosurgeon until I was in college,” Codd said. Despite all of the interesting specialties he learned about in medical school, he said “it was always neurosurgery that brought me back.”

Currently, he is exclusively conducting cranial surgery.

 Neurosurgeon U.S. Air Force Maj Jonathan Forbes,looks through loupes as he performs brain surgery at the Bagram Air Field in Afghanistan, Oct. 10, 2014. 

Though Dr. Codd has earned many leadership positions in his career, he said he was never focused on advancement. He simply enjoys working on topics which he loves, such as improving minimally invasive surgical techniques. But being in leadership lets him unite other people who are interested in working towards a common goal in research and development. He has been able to skillfully bring people together from various specialties and help guide them. However, it is difficult to meet everyone’s needs all of the time. What is important for him is to be a leader when he needs to be.

Dr. Codd said there are typically five to eight research papers necessary in to lay the groundwork for every device that is developed. However, some technologies are based on the development of a single paper. He has worked on devices that make surgery more efficient and less minimally invasive and those that help the surgical team work together better. When developing technologies, he tries to keep the original purpose of the devices the same. However, many revisions are made to the initial design plans as requirements from the FDA and other institutions must be met. Ironically, Dr. Codd can’t use the devices he develops in his own operating room because it would be a conflict of interest. Typically other neurosurgeons from across the country will use them instead.

Post by Andrew Bahhouth, NCSSM 2020

Sharing is Caring, But How Does it Start?

This is the second of several posts written by students at the North Carolina School of Science and Math as part of an elective about science communication with Dean Amy Sheck.

As an occasional volunteer at a local children’s museum, I can tell you that children take many different approaches to sharing. Some will happily lend others their favorite toys, while others will burst into tears at the suggestion of giving others a turn in an exhibit.

For Rita Svetlova Ph.D. at the Duke Empathy Development Lab, these behaviors aren’t just passing observations, they are her primary scientific focus. In November, I sat down with Dr. Svetlova to discuss her current research, past investigations, and future plans.

Margarita Lvovna Svetlova

Originally from Russia, Svetlova obtained an M.A. from Lomonosov Moscow State University in Moscow before earning her Ph.D in developmental psychology from the University of Pittsburgh. She later worked as a post-doctoral researcher at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.

Now at Duke University as an assistant research professor of psychology and neuroscience and the principal investigator in the Empathy Development Lab, Svetlova looks at the development of ‘prosocial’ behavior in children — behaviors such as sharing, empathy, and teamwork.

Svetlova credits her mentor at the University of Pittsburgh, Dr. Celia Brownell, for inspiring her to pursue child psychology and development. “I’ve always been interested in prosociality, but when I was in Russia I actually studied linguistics,” she says. “When I moved to the U.S., I changed paths partly because I’ve always wanted to know more about human psychology. The reason I started studying children is partly because I was interested in it and partly because I met Dr. Brownell. I branched out a little bit, but I generally found it interesting.”

An unsuccessful sharing experience. (From Awkward Family Photos)

Although her passion for childhood development research began in Pittsburgh,  Svetlova has embraced her role as a Duke researcher, most recently tackling a scenario that most academically-inclined readers are familiar with — a partner’s failure to perform in a joint-commitment — in a co-authored May 2017 paper titled “Three-Year-Olds’ Reactions to a Partner’s Failure to Perform Her Role in a Joint Commitment.”

In the study, 144 three-year-olds were presented with a common joint commitment scenario: playing a game. For one third of the children, the game ended when their partner defected, while another third of the test group had a partner who didn’t know how to play.  The final third of the group saw the game apparatus break. Svetlova looked at how the children’s reactions varied by scenario: protesting defectors, teaching the ignorant partner, and blaming the broken apparatus. The results seem to suggest that three-year-olds have the ability to evaluate intentions in a joint commitment.

Another paper Svetlova co-authored, titled “Three- and 5-Year-Old Childrens’ Understanding of How to Dissolve a Joint Commitment,” compared the reactions of three- and five-year-olds when a puppet left a collaborative game with either permission, prior notification, or suddenly without prior notification. If the puppet left without warning, three-year-old subjects protested more and waited longer for the puppet’s return, but both age groups seemed to understand the agreement implicit in a joint commitment.

These joint commitments are only a small fraction of the questions that Svetlova hopes to address.

“A longitudinal study of prosociality would be amazing,” she says. “What I’m interested in now is the intersection of fairness understanding and in-group/out-group bias. What I am trying to look into is how children understand their in-group members vs. out-group members and whether there’s something we can do to make them more accepting of their out-group members.”

“Another one I am interested in is the neural basis of empathy and prosocial behavior. I haven’t started yet, but I’m planning a couple of studies on looking into the brain mechanisms of empathy in particular,” Svetolova says. “We plan to scan children and adults while experiencing an emotion themselves and compare that brain activation to the brain activation while witnessing someone experiencing an emotion, the question being ‘do we really feel others’ emotions as our own?’”

Svetlova also expressed her interest in the roles that gender, culture, and upbringing play in a child’s development of prosociality.

I had to ask her why teenagers seemed to “regress” in prosociality, seemingly becoming more selfish when compared to their childhood selves.

“I would distinguish between self-centered and selfish,” she assured me. “You are not necessarily selfish, it’s just that during teenagehood you are looking for your place in the world, in the ‘pack.’ That’s why these things become very important, other’s opinions about you and your reputation in this little group, people become very anxious about it, it doesn’t mean that they become selfish all of a sudden or stop being prosocial.” She added, “I believe in the good in people, including teenagers.”

Guest Post by Sellers Hill, NCSSM 2020

How Do You Engineer a Microbial Community?

This is the first of several posts written by students at the North Carolina School of Science and Math as part of an elective about science communication with Dean Amy Sheck.

Claudia Gunsch, the Theodore Kennedy distinguished associate professor in the department of civil and environmental engineering, wants to know how to engineer a microbial community. An environmental engineer with a fascination for the world at the micro level, Gunsch takes a unique approach to solving the problem of environmental pollution: She looks to what’s already been done by nature.

Claudia Gunsch, Ph.D.

Gunsch and her team seek to harness the power of microbes to create living communities capable of degrading contamination in the environment.

“How can you engineer that microbial community so the organisms that degrade the pollutant become enriched?” she asks. “Or — if you’re thinking about dangerous pathogenic organisms — how do you engineer the microbial community so that those organisms become depressed in that particular environment?”

The first step, Gunsch says, is to figure out who’s there. What microbes make up a community? How do these organisms function? Who is doing what? Which organisms are interchangeable? Which prefer to live with one another, and which prefer not living with one another?

“Once we can really start building that kind of framework,” she says, “we can start engineering it for our particular purposes.”

Yet identifying the members of a microbial community is far more difficult than it may seem. Shallow databases coupled with vast variations in microbial communities leave Gunsch and her team with quite a challenge. Gunsch, however, remains optimistic.

Map of U.S. Superfund Sites (2013)

“The exciting part is that we have all these technologies where we can sequence all these samples,” she says. “As we become more sophisticated and more people do this type of research, we keep feeding all of this data into these databases. Then we will have more information and one day, we’ll be able to go out and take that sample and know exactly who’s there.”

“Right now, it’s in its infancy,” she says with a smile. “But in the long-term, I have no doubt we will get there.”

Gunsch is currently working on Duke’s Superfund Research Center designing bioremediation technologies for the degradation of polycyclic aromatic hydrocarbon (PAH) contamination. These pollutants are extremely difficult to break down due to their tendency to stick strongly onto soil and sediments. Gunsch and her team are searching for the right microbial community to break these compounds down — all by taking advantage of the innate capabilities of these microorganisms.

A photo montage from Dr. Gunsch’s lab page.

Step one, Gunsch says, has already been completed. She and her team have identified several different organisms capable of degrading PAHs. The next step, she explains, is assembling the microbial communities — taking these organisms and getting them to work together, sometimes even across kingdoms of life. Teamwork at the micro level.

The subsequent challenge, then, is figuring out how these organisms will survive and thrive in the environment they’re placed in, and which microbial seeds will best degrade the contamination when placed in the environment. This technique is known as “precision bioremediation” — similar to precision medicine, it involves finding the right solution in the right amounts to be the most effective in a certain scenario.

“In this particular case, we’re trying to figure out what the right cocktail of microbes we can add to an environment that will lead to the end result that is desired — in this case, PAH degradation,” Gunsch says.

Ultimately, the aim is to reduce pollution and restore ecological health to contaminated environments. A lofty goal, but one within sight. Yet Gunsch sees applications beyond work in the environment — all work dealing with microbes, she says, has the potential to be impacted by this research.

“If we understand how these organisms work together,” she says, “then we can advance our understanding of human health microbiomes as well.”

Post by Emily Yang, NCSSM 2021

Stalking Elusive Ferns Down Under

Graduate student Karla Sosa (left) photographs and presses newly collected ferns for later analysis while Ashley Field (in truck) marks the GPS location of the find.

In Queensland, Australia, early March can be 96 degrees Fahrenheit. It’s summer in the Southern Hemisphere, but that’s still pretty hot.

Although hot, dry Australia probably isn’t the first place you’d think to look for ferns, that’s precisely why I’m here and the sole reason we’ve hit the road at 6 a.m. Our schedule for the day: to drive as far south as we can while still letting us come home at the end of the day.

My local colleague, Ashley Field, grew up just the next town over. A skinny, speedy man, he works at James Cook University in Cairns and knows most of northern Queensland like the back of his hand.

Cairns is on the coast at the upper right, where the little green airplane is.

The ferns I’m looking for today are interesting because some species can move from their original home in Australia to the tiny islands in the Pacific. But some cannot. Why? Understanding what makes them different could prove useful in making our crops more resilient to harsh weather, or preventing weeds from spreading.

We’ve been driving for four hours before we turn off onto a dirt road. If you haven’t been to Australia, it’s worth noting that four hours here is unlike any four hours I’ve experienced before. The roads are fairly empty, flat, and straight, meaning you can cover a lot of terrain. Australia is also incredibly big and most of the time you’re travelling through unpopulated landscapes. While it may be only four hours, your mind feels the weight of the distance.

Here’s the one they were looking for!
Cheilanthes tenuifolia with lots of little spore babies on the undersides of its leaves.

The dirt road begins to climb into the mountains. We are leaving behind low scrub and big granite rocks that sit on the flat terrain. Ashley knows where we can find the ferns I’m looking for, but he’s never driven this road before. Instead, we’re trusting researchers who came before us. When they explored this area, they took samples of plants that were preserved and stored in museums and universities. By reviewing the carefully labelled collections at these institutions, we can know which places to revisit in hopes of finding the ferns.

Often, however, having been collected before there was GPS, the location information on these samples is not very precise, or the plants may no longer live there, or maybe that area got turned into a parking lot, as happened to me in New Zealand. So, despite careful planning, you may drive five hours one way to come up empty handed.

As we move higher up the mountain, the soil turns redder and sparse eucalyptus forests begin to enclose us. We locate the previous collections coordinates, an area that seems suitable for ferns to grow. We park the truck on the side of the road and get out to look.

We comb 300 feet along the side of the road because these ferns like the edges of forest, and we find nothing. But as we trudge back to the truck, I spot one meager fern hiding behind a creeping vine! It’s high up off the road-cut and I try to scramble up but only manage to pull a muscle in my arm. Ashley is taller, so he climbs partway up a tree and manages to fetch the fern. It’s not the healthiest, only 6 inches tall for a plant that usually grows at least 12 to 14 inches. It’s also not fertile, making it less useful for research, and in pulling it out of the ground, Ashley broke one of its three leaves off. But it’s better than nothing!

This delicate beauty has no name yet. Karla has to compare it to other ferns in the area to know whether it’s just an odd-looking variant or possibly … a new species!

Ashley excels at being a field botanist because he is not one to give up. “We should keep looking,” he says despite the sweat dripping down our faces.

We pile back in and continue up the road. And who could have predicted that just around the bend we would find dozens of tall, healthy looking ferns! There are easily fifty or so plants, each a deep green, the tallest around 12 inches. Many others are at earlier stages of growth, which can be very helpful for scientists in understanding how plants develop. We take four or five plants, enough to leave a sample at the university in Cairns and for the rest to be shipped back to the US. One sample will be kept at Duke, and the others will be distributed amongst other museums and universities as a type of insurance.

The long hours, the uncertainty, and the harsh conditions become small things when you hit a jackpot like this. Plus, being out in remote wilderness has its own soothing charm, and chance also often allows us to spot cool animals, like the frilled lizard and wallaby we saw on this trip.

Funding for this type of fieldwork is becoming increasingly rare, so I am grateful to the National Geographic Society for seeing the value in this work and funding my three-week expedition. I was able to cover about 400 miles of Australia from north to south, visiting twenty-four different sites, including eight parks, and ranging from lush rainforest to dry, rocky scrub. We collected fifty-five samples, including some that may be new species, and took careful notes and photographs of how these plants grow in the wild, something you can’t tell from dried-up specimens.

Knowing what species are out there and how they exist within the environment is important not only because it may provide solutions to human problems, but also because understanding what biodiversity we have can help us take better care of it in the future.

Guest Post by graduate student Karla Sosa

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