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

Students exploring the Innovation Co-Lab

Author: Robin Smith Page 4 of 9

Digging Into Durham’s Eviction Problem

This is what 20 years of evictions looks like. It’s an animated heat map of Durham, the streets overlaid with undulating blobs of red and orange and yellow, like a grease stain.

Duke students in the summer research program Data+ have created a time-lapse map of the more than 200,000 evictions filed in Durham County since 2000.

Dark red areas represent eviction hotspots. These neighborhoods are where families cook their favorite meals, where children do their homework, where people celebrate holidays. They’re also where many people live one crisis away from losing their neighbors, or becoming homeless themselves.

Duke junior Samantha Miezio points to a single census tract along NC 55 where, in the wake of an apartment building sale, more than 100 households received an eviction notice in that spot in one month alone. It “just speaks to the severity of the issue,” Miezio said.

Miezio was part of a team that spent 10 weeks this summer mapping and analyzing evictions data from the Durham County Sheriff’s Office, thanks to an effort by DataWorks NC to compile such data and make it more accessible.

The findings are stark.

Every hour in Durham, at least one renter is threatened with losing their home. About 1,000 eviction cases were filed a month against tenants between 2010 and 2017. That’s roughly one for every 280 residents in Durham, where evictions per capita is one of the highest in the state and double the national average.

The data tell us that while Durham’s evictions crisis has actually improved from where it was a few years ago, stubborn hotspots persist, said team member Ellis Ackerman, a math major at North Carolina State University.

When the students looked at the data month by month, a few things stood out. For one, winter evictions are common. While some countries such as France and Austria ban winter evictions to keep from pushing people onto the street in the cold, in Durham, “January is the worst month by far,” said team member Rodrigo Araujo, a junior majoring in computer science. “In the winter months utility bills are higher; they’re struggling to pay for that.”

Rodrigo Araujo (Computer Science, 2021) talks about the Durham evictions project.

The team also investigated the relationship between evictions and rents from 2012 to 2014 to see how much they move in tandem with each other. Their initial results using two years’ worth of rent data showed that when rents went up, evictions weren’t too far behind.

“Rents increased, and then two months later, evictions increased,” Miezio said.

But the impacts of rising rents weren’t felt evenly. Neighborhoods with more residents of color were significantly affected while renters in white neighborhoods were not. “This crisis is disproportionately affecting those who are already at a disadvantage from historical inequalities,” Miezio said.

A person can be evicted for a number of reasons, but most evictions happen because people get behind on their rent. The standard guideline is no more than 30% of your monthly income before taxes should go to housing and keeping the lights on.

But in Durham, where 47% of households rent rather than own a home, only half of renters meet that goal. As of 2019 an estimated 28,917 households are living in rentals they can’t afford.

The reason is incomes haven’t kept pace with rents, especially for low-wage workers such as waiters, cooks, or home health aides.

Durham’s median rents rose from $798 in 2010 to $925 in 2016. That’s out of reach for many area families. A minimum wage worker in Durham earning $7.25/hour would need to work a staggering 112 hours a week — the equivalent of nearly three full-time jobs — to afford a modest two-bedroom unit in 2019 at fair market rent, according to a report by the National Low Income Housing Coalition.

Spending a sizable chunk of your income on housing means having less left over for food, child care, transportation, savings, and other basic necessities. One unexpected expense or emergency — maybe the kid gets sick or the car needs repairs, or there’s a cut back on hours at work — can mean tenants have a harder time making the rent.

“Evictions are traumatic life experiences for the tenants,” and can have ripple effects for years, Miezio said.

Tenants may have only a few days to pay what’s due or find a new place and move out. The Sheriff may come with movers and pile a person’s belonging on the curb, or move them to a storage facility at the tenant’s expense.

A forced move can also mean children must change schools in the middle of the school year.

Benefits may go to the wrong address. Families are uprooted from their social support networks of friends and neighbors.

Not every case filed ends with the tenant actually getting forced out, “but those filings can still potentially inhibit their ability to find future housing,” Miezio said. Not to mention the cost and hassle of appearing in court and paying fines and court fees.

Multiple groups are working to help Durham residents avoid eviction and stay in their homes. In a partnership between Duke Law and Legal Aid of North Carolina, the Civil Justice Clinic’s 2-year-old Eviction Diversion Program provides free legal assistance to people who are facing eviction.

“The majority of people who have an eviction filed against them don’t have access to an attorney,” Miezio said.

In a cost-benefit analysis, the team’s models suggest that “with a pretty small increase in funding to reduce evictions, on the order of $100,000 to $150,000, Durham could be saving millions of dollars” in the form of reduced shelter costs, hospital costs, plus savings on mental health services other social services, Ackerman said.

Ellis Ackerman, a senior math major from NC State University, talks about the Durham evictions research project.

Moving forward, they’re launching a website in order to share their findings. “I’ve learned HTML and CSS this summer,” said Miezio, who is pursuing an individualized degree program in urban studies. “That’s one of the things I love about Data+. I’m getting paid to learn.”

Miezio plans to continue the project this fall through an independent study course focused on policy solutions to evictions, such as universal right to counsel.

“Housing access and stability are important to Durham,” said Duke’s vice president for Durham affairs Stelfanie Williams. “Applied research projects such as this, reflecting a partnership between the university and community, are opportunities for students to ‘learn by doing’ and to collaborate with community leaders on problem-solving.”

Data+ 2019 is sponsored by Bass Connections, the Rhodes Information Initiative at Duke, the Social Science Research Institute, the Duke Energy Initiative, and the departments of Mathematics and Statistical Science.

Other Duke sponsors include DTECH, Science, Law, and Policy Lab, Duke Health, Duke University Libraries, Sanford School of Public Policy, Nicholas School of the Environment, Duke Global Health Institute, Development and Alumni Affairs, the Duke River Center, Representing Migrations Humanities Lab, Energy Initiative, Franklin Humanities Institute, Duke Forge, the K-Lab, Duke Clinical Research, Office for Information Technology and the Office of the Provost, as well as the departments of Electrical & Computer Engineering, Computer Science, Biomedical Engineering, Biostatistics & Bioinformatics and Biology.

Government funding comes from the National Science Foundation. Outside funding comes from Exxon Mobil, the International Institute for Sustainable Development (IISD), Global Financial Markets Center, and Tether Energy.

Writing by Robin Smith; Video by Wil Weldon
Post by Robin Smith Video by Wil Weldon

800+ Teams Pitched Their Best Big Ideas. With Your Help, This Duke Team Has a Chance to Win

A Duke University professor says the time is ripe for new research on consciousness, and he needs your help.

More than 800 teams pitched their best “big ideas” to a competition sponsored by the National Science Foundation (@NSF) to help set the nation’s long-term research agenda. Only 33 are still in the running for the grand prize, and a project on the science of consciousness led by Duke artificial intelligence expert Vincent Conitzer is among them!

You can help shape the NSF’s research questions of the future by watching Conitzer’s video pitch and submitting your comments on the importance and potential impact of the ideas at https://nsf2026imgallery.skild.com/entries/theory-of-conscious-experience.

But act fast. The public comment period ends Wednesday, June 26. Winners will be announced and prizes awarded by October 2019. Stay tuned.

Watch all the video pitches until June 26 at nsf2026imgallery.skild.com.

What Happens When Data Scientists Crunch Through Three Centuries of Robinson Crusoe?

Reading 1,400-plus editions of “Robinson Crusoe” in one summer is impossible. So one team of students tried to train computers to do it for them.

Reading 1,400-plus editions of “Robinson Crusoe” in one summer is impossible. So one team of students tried to train computers to do it for them.

Since Daniel Defoe’s shipwreck tale “Robinson Crusoe” was first published nearly 300 years ago, thousands of editions and spinoff versions have been published, in hundreds of languages.

A research team led by Grant Glass, a Ph.D. student in English and comparative literature at the University of North Carolina at Chapel Hill, wanted to know how the story changed as it went through various editions, imitations and translations, and to see which parts stood the test of time.

Reading through them all at a pace of one a day would take years. Instead, the researchers are training computers to do it for them.

This summer, Glass’ team in the Data+ summer research program used computer algorithms and machine learning techniques to sift through 1,482 full-text versions of Robinson Crusoe, compiled from online archives.

“A lot of times we think of a book as set in stone,” Glass said. “But a project like this shows you it’s messy. There’s a lot of variance to it.”

“When you pick up a book it’s important to know what copy it is, because that can affect the way you think about the story,” Glass said.

Just getting the texts into a form that a computer could process proved half the battle, said undergraduate team member Orgil Batzaya, a Duke double major in math and computer science.

The books were already scanned and posted online, so the students used software to download the scans from the internet, via a process called “scraping.” But processing the scanned pages of old printed books, some of which had smudges, specks or worn type, and converting them to a machine-readable format proved trickier than they thought.

The software struggled to decode the strange spellings (“deliver’d,” “wish’d,” “perswasions,” “shore” versus “shoar”), different typefaces between editions, and other quirks.

Special characters unique to 18th century fonts, such as the curious f-shaped version of the letter “s,” make even humans read “diftance” and “poffible” with a mental lisp.

Their first attempts came up with gobbledygook. “The resulting optical character recognition was completely unusable,” said team member and Duke senior Gabriel Guedes.

At a Data+ poster session in August, Guedes, Batzaya and history and computer science double major Lucian Li presented their initial results: a collection of colorful scatter plots, maps, flowcharts and line graphs.

Guedes pointed to clusters of dots on a network graph. “Here, the red editions are American, the blue editions are from the U.K.,” Guedes said. “The network graph recognizes the similarity between all these editions and clumps them together.”

Once they turned the scanned pages into machine-readable texts, the team fed them into a machine learning algorithm that measures the similarity between documents.

The algorithm takes in chunks of texts — sentences, paragraphs, even entire novels — and converts them to high-dimensional vectors.

Creating this numeric representation of each book, Guedes said, made it possible to perform mathematical operations on them. They added up the vectors for each book to find their sum, calculated the mean, and looked to see which edition was closest to the “average” edition. It turned out to be a version of Robinson Crusoe published in Glasgow in 1875.

They also analyzed the importance of specific plot points in determining a given edition’s closeness to the “average” edition: what about the moment when Crusoe spots a footprint in the sand and realizes that he’s not alone? Or the time when Crusoe and Friday, after leaving the island, battle hungry wolves in the Pyrenees?

The team’s results might be jarring to those unaccustomed to seeing 300 years of publishing reduced to a bar chart. But by using computers to compare thousands of books at a time, “digital humanities” scholars say it’s possible to trace large-scale patterns and trends that humans poring over individual books can’t.

“This is really something only a computer can do,” Guedes said, pointing to a time-lapse map showing how the Crusoe story spread across the globe, built from data on the place and date of publication for 15,000 editions.

“It’s a form of ‘distant reading’,” Guedes said. “You use this massive amount of information to help draw conclusions about publication history, the movement of ideas, and knowledge in general across time.”

This project was organized in collaboration with Charlotte Sussman (English) and Astrid Giugni (English, ISS). Check out the team’s results at https://orgilbatzaya.github.io/pirating-texts-site/

Data+ is sponsored by Bass Connections, the Information Initiative at Duke, the Social Science Research Institute, the departments of Mathematics and Statistical Science and MEDx. This project team was also supported by the Duke Office of Information Technology.

Other Duke sponsors include DTECH, Duke Health, Sanford School of Public Policy, Nicholas School of the Environment, Development and Alumni Affairs, Energy Initiative, Franklin Humanities Institute, Duke Forge, Duke Clinical Research, Office for Information Technology and the Office of the Provost, as well as the departments of Electrical & Computer Engineering, Computer Science, Biomedical Engineering, Biostatistics & Bioinformatics and Biology.

Government funding comes from the National Science Foundation.

Outside funding comes from Lenovo, Power for All and SAS.

Community partnerships, data and interesting problems come from the Durham Police and Sheriff’s Department, Glenn Elementary PTA, and the City of Durham.

Videos by Paschalia Nsato and Julian Santos; writing by Robin Smith

Can’t Decide What Clubs to Join Outside of Class? There’s a Web App for That

With 400-plus student organizations to choose from, Duke has more co-curriculars than you could ever hope to take advantage of in one college career. Navigating the sheer number of options can be overwhelming. So how do you go about finding your niche on campus?

Now there’s a Web app for that: the Duke CoCurricular Eadvisor. With just a few clicks it comes up with a personalized ranked list of student clubs and programs based on your interests and past participation compared to others.

“We want it to be like the activity fair, but online,” said  Duke computer science major Dezmanique Martin, who was part of a team of Duke undergrads in the Data+ summer research program who developed the “recommendation engine.”

“The goal is to make a web app that recommends activities like Netflix recommends movies,” said team member Alec Ashforth.

The project is still in the testing stage, but you can try it out for yourself, or add your student organization to the database, at https://eadvisorduke.shinyapps.io/login/

A “co-curricular” can be just about any learning experience that takes place outside of class and doesn’t count for credit, be it a student magazine, Science Olympiad or community service. Research shows that students who get involved on campus are more likely to graduate and thrive in the workplace post-graduation.

For the pilot version, the team compiled a list of more than 150 student programs related to technology. Each program was tagged with certain attributes.

Students start by entering a Net ID, major, and expected graduation date. Then they enter all the programs they have participated in at Duke so far, submit their profile, and hit “recommend.”

The e-advisor algorithm generates a ranked list of activities recommended just for the user.

The e-advisor might recognize that a student who did DataFest and HackDuke in their first two years likes computer science, research, technology and competitions. Based on that, the Duke Robotics Club might be highly recommended, while the Refugee Health Initiative would be ranked lower.

A new student can just indicate general interests by selecting a set of keywords from a drop-down menu. Whether it’s literature and humanities, creativity, competition, or research opportunities, the student and her advisor won’t have to puzzle over the options — the e-advisor does it for them.

The tool comes up with its recommendations using a combination of approaches. One, called content-based filtering, finds activities you might like based on what you’ve done in the past. The other, collaborative filtering, looks for other students with similar histories and tastes, and recommends activities they tried.

This could be a useful tool for advisors, too, noted Vice Provost for Interdisciplinary Studies Edward Balleisen, while learning about the EAdvisor team at this year’s Data+ Poster Session.

“With sole reliance on the app, there could be a danger of some students sticking with well-trodden paths, at the expense of going outside their comfort zone or trying new things,” Balleisen said.

But thinking through app recommendations along with a knowledgeable advisor “might lead to more focused discussions, greater awareness about options, and better decision-making,” he said.

Led by statistics Ph.D. candidate Lindsay Berry, so far the team has collected data from more than 80 students. Moving forward they’d like to add more co-curriculars to the database, and incorporate more features, such as an upvote/downvote system.

“It will be important for the app to include inputs about whether students had positive, neutral, or negative experiences with extra-curricular activities,” Balleisen added.

The system also doesn’t take into account a student’s level of engagement. “If you put Duke machine learning, we don’t know if you’re president of the club, or just a member who goes to events once a year,” said team member Vincent Liu, a rising sophomore majoring in computer science and statistics.

Ultimately, the hope is to “make it a viable product so we can give it to freshmen who don’t really want to know what they want to do, or even sophomores or juniors who are looking for new things,” said Brooke Keene, rising junior majoring in computer science and electrical and computer engineering.

Video by Paschalia Nsato and Julian Santos; writing by Robin Smith

Data+ is sponsored by Bass Connections, the Information Initiative at Duke, the Social Science Research Institute, the departments of Mathematics and Statistical Science and MEDx. This project team was also supported by the Duke Office of Information Technology.

Other Duke sponsors include DTECH, Duke Health, Sanford School of Public Policy, Nicholas School of the Environment, Development and Alumni Affairs, Energy Initiative, Franklin Humanities Institute, Duke Forge, Duke Clinical Research, Office for Information Technology and the Office of the Provost, as well as the departments of Electrical & Computer Engineering, Computer Science, Biomedical Engineering, Biostatistics & Bioinformatics and Biology.

Government funding comes from the National Science Foundation.

Outside funding comes from Lenovo, Power for All and SAS.

Community partnerships, data and interesting problems come from the Durham Police and Sheriff’s Department, Glenn Elementary PTA, and the City of Durham.

Researcher Turns Wood Into Larger-Than-Life Insects

Duke biologist Alejandro Berrio creates larger-than-life insect sculptures. This wooden mantis was exhibited at the Art Science Gallery in Austin, Texas in 2013.

Duke biologist Alejandro Berrio creates larger-than-life insect sculptures. This wooden mantis was exhibited at the Art Science Gallery in Austin, Texas in 2013.

On a recent spring morning, biologist Alejandro Berrio took a break from running genetic analyses on a supercomputer to talk about an unusual passion: creating larger-than-life insect sculptures.

Berrio is a postdoctoral associate in professor Greg Wray’s lab at Duke. He’s also a woodcarver, having exhibited his shoebox-sized models of praying mantises, wasps, crickets and other creatures in museums and galleries in his hometown and in Austin, Texas, where his earned his Ph.D.

The Colombia-born scientist started carving wood in his early teens, when he got interested in model airplanes. He built them out of pieces of lightweight balsa wood that he bought in craft shops.

When he got to college at the University of Antioquia in Medellín, Colombia’s second-largest city, he joined an entomology lab. “One of my first introductions to science was watching insects in the lab and drawing them,” Berrio said. “One day I had an ‘aha’ moment and thought: I can make this. I can make an insect with wings the same way I used to make airplanes.”

Beetle carved by Duke biologist Alejandro Berrio.

His first carvings were of mosquitoes — the main insect in his lab — hand carved from soft balsa wood with an X-Acto knife.

Using photographs for reference, he would sketch the insects from different positions before he started carving.

He worked at his kitchen table, shaping the body from balsa wood or basswood. “I might start with a power saw to make the general form, and then with sandpaper until I started getting the shape I wanted,” Berrio said.

He used metal to join and position the segments in the legs and antennae, then set the joints in place with glue.

“People loved them,” Berrio said. “Scientists were like: Oh, I want a fly. I want a beetle. My professors were giving them to their friends. So I started making them for people and selling them.”

Soon Berrio was carving wooden fungi, dragons, turtles, a snail. “Whatever people wanted me to make,” Berrio said.

He earned just enough money to pay for his lunch, or the bus ride to school.

Duke biologist Alejandro Berrio carved this butterfly using balsa wood for the body and legs, and paper for the wings.

His pieces can take anywhere from a week to two months to complete. “This butterfly was the most time-consuming,” he said, pointing to a model with translucent veined wings.

Since moving to Durham in 2016, he has devoted less time to his hobby than he once did. “Last year I made a crab for a friend who studies crustaceans,” Berrio said. “She got married and that was my wedding gift.”

Still no apes, or finches, or prairie voles — all subjects of his current research. “But I’m planning to restart,” Berrio said. “Every time I go home to Colombia I bring back some wood, or my favorite glue, or one of my carving tools.”

Insect sculptures by Duke biologist Alejandro Berrio.

Insect sculptures by Duke biologist Alejandro Berrio.

Explore more of Berrio’s sculpture and photography at https://www.flickr.com/photos/alejoberrio/.

by Robin Smith

by Robin Smith

High as a Satellite — Integrating Satellite Data into Science

Professor Tracey Holloway researches air quality at the University of Wisconsin-Madison.

Professor Tracey Holloway researches air quality at the University of Wisconsin-Madison.

Satellite data are contributing more and more to understanding air quality trends, and professor Tracey Holloway wants the world to know.

As a professor of the Department of Atmospheric and Oceanic Science at University of Wisconsin-Madison and the current Team Lead of the NASA Health and Air Quality Applied Sciences Team (HAQAST), she not only helps with the science related to satellites, but also the communication of findings to larger audiences.

Historically, ground-based monitors have provided estimates on changes in concentrations of air pollutants, Holloway explained in her March 2, 2018 seminar, “Connecting Science with Stakeholders,” organized by Duke’s Earth and Ocean Sciences department.

Despite the valuable information ground-based monitors provide, however, factors like high costs limit their widespread use. For example, only about 400 ground-based monitors for nitrogen dioxide currently exist, with many states in the U.S. entirely lacking even a single one. Almost no information on nitrogen dioxide levels had therefore existed before satellites came into the picture.

To close the gap, HAQAST employed earth-observing and polar-orbiting satellites — with fruitful results. Not only have they provided enough data to make more comprehensive maps showing nitrogen dioxide distributions and concentrations, but they also have detected formaldehyde, one of the top causes of cancer, in our atmosphere for the first time.

Satellites have additional long-term benefits. They can help determine potential monitoring sites before actually having to invest large amounts of resources. In the case of formaldehyde, satellite-generated information located areas of higher concentrations — or formaldehyde “hotspots” —  in which HAQAST can now prioritize placing a ground-based monitor. Once established, the site can evaluate air dispersion models, provide air quality information to the public and add to scientific research.

A slide form Holloway’s presentation, in the LSRC A building on March 2, explaining the purposes of a monitoring site.

A slide from Holloway’s presentation, in the LSRC A building on March 2, explaining the purposes of a monitoring site.

Holloway underscored the importance of effectively communicating science. She explained that many policymakers don’t have the strong science backgrounds and therefore need quick and friendly explanations of research from scientists.

Perhaps more significant, though, is the fact that some people don’t even realize that information exists. Specifically, people don’t realize that more satellites are producing new information every day; Holloway has made it a personal goal to have more one-on-one conversations with stakeholders to increase transparency.

Breakthroughs in science aren’t made by individuals: science and change are collaborative. And for Holloway, stakeholders also include the general public. She founded the Earth Science Women’s Network, with one of her goals being to change the vision of what a “scientist” looks like. Through photo campaigns and other communication and engagement activities, she interacted with adults and children to make science more appealing. By making science more sexy, it would be easier to inspire new and continue old discussions, create a more diverse research environment, and make the field more open for all.

Professor Tracey Holloway, air quality researcher at University of Wisconsin-Madison, presented her research at Duke on March 2, 2018.

Professor Tracey Holloway, air quality researcher at University of Wisconsin-Madison, presented her research at Duke on March 2, 2018.

Post by Stella Wang, class of 2019

Post by Stella Wang, class of 2019

Researchers Get Superman’s X-ray Vision

X-ray vision just got cooler. A technique developed in recent years boosts researchers’ ability to see through the body and capture high-resolution images of animals inside and out.

This special type of 3-D scanning reveals not only bones, teeth and other hard tissues, but also muscles, blood vessels and other soft structures that are difficult to see using conventional X-ray techniques.

Researchers have been using the method, called diceCT, to visualize the internal anatomy of dozens of different species at Duke’s Shared Materials Instrumentation Facility (SMIF).

There, the specimens are stained with an iodine solution that helps soft tissues absorb X-rays, then placed in a micro-CT scanner, which takes thousands of X-ray images from different angles while the specimen spins around. A computer then stitches the scans into digital cross sections and stacks them, like slices of bread, to create a virtual 3-D model that can be rotated, dissected and measured as if by hand.

Here’s a look at some of the images they’ve taken:

See-through shrimp

If you get flushed after a workout, you’re not alone — the Caribbean anemone shrimp does too.

Recent Duke Ph.D. Laura Bagge was scuba diving off the coast of Belize when she noticed the transparent shrimp Ancylomenes pedersoni turn from clear to cloudy after rapidly flipping its tail.

To find out why exercise changes the shrimp’s complexion, Bagge and Duke professor Sönke Johnsen and colleagues compared their internal anatomy before and after physical exertion using diceCT.

In the shrimp cross sections in this video, blood vessels are colored blue-green, and muscle is orange-red. The researchers found that more blood flowed to the tail after exercise, presumably to deliver more oxygen-rich blood to working muscles. The increased blood flow between muscle fibers causes light to scatter or bounce in different directions, which is why the normally see-through shrimp lose their transparency.

Peer inside the leg of a mouse

Duke cardiologist Christopher Kontos, M.D., and MD/PhD student Hasan Abbas have been using the technique to visualize the inside of a mouse’s leg.

The researchers hope the images will shed light on changes in blood vessels in people, particularly those with peripheral artery disease, in which plaque buildup in the arteries reduces blood flow to the extremities such as the legs and feet.

The micro-CT scanner at Duke’s Shared Materials Instrumentation Facility made it possible for Abbas and Kontos to see structures as small as 13 microns, or a fraction of the width of a human hair, including muscle fibers and even small arteries and veins in 3-D.

Take a tour through a tree shrew

DiceCT imaging allows Heather Kristjanson at the Johns Hopkins School of Medicine to digitally dissect the chewing muscles of animals such as this tree shrew, a small mammal from Southeast Asia that looks like a cross between a mouse and a squirrel. By virtually zooming in and measuring muscle volume and the length of muscle fibers, she hopes to see how strong they were. Studying such clues in modern mammals helps Kristjanson and colleagues reconstruct similar features in the earliest primates that lived millions of years ago.

Try it for yourself

Students and instructors who are interested in trying the technique in their research are eligible to apply for vouchers to cover SMIF fees. People at Duke University and elsewhere are encouraged to apply. For more information visit https://smif.pratt.duke.edu/Funding_Opportunities, or contact Dr. Mark Walters, Director of SMIF, via email at mark.walters@duke.edu.

Located on Duke’s West Campus in the Fitzpatrick Building, the SMIF is a shared use facility available to Duke researchers and educators as well as external users from other universities, government laboratories or industry through a partnership called the Research Triangle Nanotechnology Network. For more info visit http://smif.pratt.duke.edu/.

Post by Robin Smith, News and Communications

Post by Robin Smith, News and Communications

Meet Africa’s Bird Master of Vocal Imitation

The red-capped robin-chat (Cossypha natalensis) can mimic the songs and calls of dozens of other bird species – even their duets, says Duke researcher Tom Struhsaker.

The red-capped robin-chat (Cossypha natalensis) can mimic the songs and calls of dozens of other bird species – even their duets, says Duke researcher Tom Struhsaker.

Singing a duet in a foreign language isn’t just for opera stars — red-capped robin-chats do it too. These orange-brown birds with grey wings can imitate the sounds of 40 other bird species, even other species’ high-speed duets.

The latter finding comes from Tom Struhsaker, adjunct professor of evolutionary anthropology at Duke. Struhsaker didn’t set out to study robin-chats. His interest in their vocal abilities developed while studying monkeys in Kibale Forest in Uganda, where he lived for nearly two decades from 1970 to 1988.

Their typical song “sounds like a long, rambling human-like whistle,” Struhsaker said. But during the 18 years he spent studying and living in Kibale, Struhsaker also heard these birds impersonate the tambourine-like courtship call of the crested guineafowl, the crow of a rooster, and the “puweepuweepuwee” of a crowned eagle, among others.

“The robin-chat’s ability to imitate is so good that many a bird watcher has looked skyward vainly searching for a crowned eagle performing its aerial display, when in fact the source of the eagle’s undulating whistle was a robin-chat in the nearby understory,” Struhsaker said.

He also noticed that if he whistled, eavesdropping robin-chats would approach and call back, and if he tweaked the pitch and sequence of notes in his whistle, the birds sometimes changed their reply.

This suggests red-capped robin-chats may be lifelong learners, unlike many other bird species that only learn songs during critical time windows, Struhsaker said.

But the robin-chat doesn’t stop at mimicking others’ solo performances. Notably, Struhsaker also heard them imitate the duet of the black-faced rufous warbler.

Black-faced rufous warblers sing a rapid-fire “seee-oooo-ee” duet with their mates. The two birds take turns such that the male sings the “seee,” the female chimes in with the “oooo” and the male fires back with the final “ee,” with no pauses between the three notes. The partners sing back and forth so seamlessly that they are often mistaken for a single bird.

“In order to do this, birds have an incredibly rapid reaction time, much greater than that of humans,” Struhsaker said.

On two occasions he heard single robin-chats sing both the male and female parts of the warbler duet by themselves. On another occasion he heard two robin-chats make music together as the warblers do, with one singing the male warbler’s part and the other singing the female part.

“This suggests these birds have an unusually high level of auditory perception and reaction time and cognitive ability,” Struhsaker said.

CITATION:  “Two Red-Capped Robin-Chats Cossypha Natalensis Imitate Antiphonal Duet of Black-Faced Rufous Warblers Bathmocercus rufus,” Thomas Struhsaker. Journal of East African Natural History, Dec. 2017. https://doi.org/10.2982/028.106.0201.

 

Some Lemurs are Loners, Others Crave Connection

DURHAM, N.C. — If lemurs were on Facebook, Fern would have oodles of friends, liking and commenting on their posts. Captain Lee, on the other hand, would rarely send a friend request.

Best buddies Fern and Alena at the Duke Lemur Center in Durham, North Carolina. Photo by Ipek Kulahci.

Best buddies Fern and Alena at the Duke Lemur Center in Durham, North Carolina. Photo by Ipek Kulahci.

These are just two of the distinct personalities discovered in a recent study of group dynamics in ring-tailed lemurs, primate cousins that live in groups of up to two dozen on the island of Madagascar.

First author Ipek Kulahci spent several years studying ring-tailed lemurs housed at the Duke Lemur Center in North Carolina and the St. Catherines Island Lemur Program in Georgia. Along the way, she noticed a lot of variation in social behavior from one lemur the next. She observed socialite Fern, loner Captain Lee, best buddies Limerick and Herodotus and other lemur characters.

Some individuals seemed more outgoing than others. To try to quantify that, she followed four groups of ring-tailed lemurs over two consecutive years and recorded their behavior a minimum of four times a week for at least two months.

A social network of lemurs. Each circle represents an individual lemur, and lemurs who respond to each other’s calls are connected by arrows. Thicker arrows indicate lemurs who respond more frequently and have a stronger social bond.

A social network of lemurs. Each circle represents an individual lemur, and lemurs who respond to each other’s calls are connected by arrows. Thicker arrows indicate lemurs who respond more frequently and have a stronger social bond.

Using a method called social network analysis, she was able to measure how many connections each lemur had, with whom, and how strong those connections were. She was also able to figure out which lemurs were most influential in each group — either because they connected others, or because they had well-connected friends.

Kulahci and colleagues found that lemurs behaved consistently no matter what their age, sex or social situation. Some lemurs like Fern tended to seek connection; reinforcing social bonds by frequently picking through their friends’ fur and responding to other lemurs’ calls and scent marks.

Their interactions weren’t always amicable — the more socially active lemurs were also more likely to chase others or pick fights with individuals with whom they weren’t on friendly terms. “But they have a drive to interact with others, rather than be a loner,” said Kulahci, now a postdoctoral researcher at University College Cork in Ireland.

The researchers also found that lemurs, like us, don’t bond with just anyone. Whether they were extroverted or shy, all lemurs had an inner circle of groupmates they tended to groom, call back, or otherwise keep in touch with more than others.

Ipek Kulahci, postdoctoral researcher at University College Cork in Ireland.

Ipek Kulahci, postdoctoral researcher at University College Cork in Ireland.

“They essentially have buddies,” Kulahci said.

“This is important because social connectedness influences health, immunity, survival,” Kulahci said. “This is true for animals as well as humans.”

The results appeared online Dec. 9, 2017, in the journal Animal Behaviour.

Other authors on this study include Asif Ghazanfar and Daniel Rubenstein of Princeton University. This study was funded by grants from the Animal Behavior Society, American Society of Mammalogists, American Society of Primatologists and Princeton University.

CITATION:  “Consistent Individual Variation Across Interaction Networks Indicates Social Personalities in Lemurs,” Ipek Kulahci, Asif Ghazanfar and Daniel Rubenstein. Animal Behaviour, Dec. 9, 2017.  https://doi.org/10.1016/j.anbehav.2017.11.012

by Robin Smith

by Robin Smith

Captive Lemurs Get a Genetic Health Checkup

DURHAM, N.C. — Careful matchmaking can restore genetic diversity for endangered lemurs in captivity, researchers report.

Ring-tailed lemurs born at the Duke Lemur Center have seen a recent infusion of new genetic material at key genes involved in the immune response, finds a new study.

Thanks to a long-term collaborative breeding program that transfers animals between institutions to preserve genetic diversity, genetic variation at one region was restored to levels seen in the wild.

The findings, published in the journal Ecology and Evolution, are important for the ability of future generations to fight disease.

Baby lemur twins Nemesis and Narcissa were the product of a breeding program developed by the American Association of Zoos and Aquariums to preserve the future genetic health of North America’s captive ring-tailed lemurs. Their mother Sophia was among 62 ring-tailed lemurs recommended for breeding across 20 institutions nationwide in 2016. Photo by David Haring, Duke Lemur Center.

Baby lemur twins Nemesis and Narcissa were the product of a breeding program developed by the American Association of Zoos and Aquariums to preserve the future genetic health of North America’s captive ring-tailed lemurs. Their mother Sophia was among 62 ring-tailed lemurs recommended for breeding across 20 institutions nationwide in 2016. Photo by David Haring, Duke Lemur Center.

Distant primate cousins with long black-and-white striped tails, ring-tailed lemurs live on the African island of Madagascar and nowhere else except in zoos and other captive facilities.

Some studies suggest that as few as 2,500 ring-tailed lemurs live in the wild today. Habit loss, hunting and the illegal pet trade have reduced their numbers by at least 50 percent in recent decades.

An additional estimated 2,500 ring-tailed lemurs live in zoos around the world, where experts work to maintain their genetic health in captivity.

The researchers studied DNA sequence variation at a region of the major histocompatibility complex, or MHC, a part of the genome that helps the immune system identify disease-causing bacteria, viruses and parasites.

Because different MHC gene variants recognize different types of pathogens, greater MHC diversity means animals are able to fend off a wider array of invaders.

The researchers estimated the number of MHC variants in 121 captive individuals born at the Duke Lemur Center and the Indianapolis and Cincinnati Zoos between 1980 and 2010.

They also compared them with 180 wild individuals from southwestern Madadgascar at the Bezà Mahafaly Special Reserve, where the animals regularly interbreed with lemurs from nearby forests.

Not surprisingly, MHC diversity was lower in captivity than in the wild.

Today’s captive ringtails came from a small group of ancestors that carried only a small fraction of the total genetic variation found in the larger wild population. Since their establishment, gene flow between captive populations and wild lemurs has been restricted.

Overall, the researchers found 20 unique MHC variants in the captive population, fewer than half the number in their wild counterparts.

However, efforts to identify good genetic matches across dozens of institutions have helped to preserve and even improve upon the diversity that is left.

For infants born at the Duke Lemur Center, MHC gene diversity remained low but stable for three decades from 1980 to 2010, then increased significantly from 2010 to 2013, researchers found.

Genetic contributions from several transplants contributed to the comeback.

An arranged marriage between ring-tailed lemurs at the Duke Lemur Center in North Carolina produced healthy twins Griselda and Hedwig in 2016. The infants are among 40 to 60 ring-tailed lemur infants born in North American zoos and other facilities each year. Photo by David Haring, Duke Lemur Center.

An arranged marriage between ring-tailed lemurs at the Duke Lemur Center in North Carolina produced healthy twins Griselda and Hedwig in 2016. The infants are among 40 to 60 ring-tailed lemur infants born in North American zoos and other facilities each year. Photo by David Haring, Duke Lemur Center.

The American Association of Zoos and Aquariums (AZA) tries to maintain a genetically healthy population by moving animals between institutions as potential mates. A team of experts uses computer software to help pick the best pairs for breeding.

Between 1980 and 2013, more than 1,160 ring-tailed lemurs were transferred between 217 institutions in North America alone.

In 2009, a male named Randy was transferred from the Saint Louis Zoo to the Duke Lemur Center for pairing with Sprite, a resident female. Experts also brought a mother-daughter pair, Schroeder and Leisl from the Zoo at Chehaw in Georgia, as potential mates for a resident male named Aracus.

“They saw an immediate improvement in the diversity of the offspring that were born,” said lead author Kathleen Grogan, who conducted the study while working on a doctorate with co-author Christine Drea at Duke University.

Grogan and colleagues are now examining whether MHC gene diversity helps the animals live longer or produce more offspring, as has been shown for other species.

“Not only do these lemurs serve as an assurance against extinction of their Malagasy counterparts, but maintaining as many variations of genes is important for keeping the individual lemurs, as well as the population healthy for any future challenges it may face,” said AZA Species Survival Plan Coordinator Gina Ferrie, a population biologist at Disney’s Animal Kingdom.

Conserving genetic diversity in captive populations over multiple generations is challenging due to their small size and relative isolation, but careful breeding can stem the loss, said Grogan, now a postdoctoral fellow at Pennsylvania State University.

Other authors include Michelle Sauther of the University of Colorado-Boulder and Frank Cuozzo at LaJuma Research Centre in South Africa.

This research was supported by Duke University, the International Primatological Society, Primate Conservation Inc., the University of Colorado-Boulder, the University of North Dakota, the National Science Foundation (BCS 0922465, BCS-1232570, IOS-071900), the Margot Marsh Biodiversity Foundation, the St. Louis Zoo and the American Society of Primatologists.

CITATION:  “Genetic Wealth, Population Health: Major Histocompatibility Complex Variation in Captive and Wild Ring-Tailed Lemurs (Lemur Catta),” Kathleen Grogan, Michelle Sauther, Frank Cuozzo and Christine Drea. Ecology and Evolution, Date. DOI: 10.1002/ece3.3317

Page 4 of 9

Powered by WordPress & Theme by Anders Norén