Duke Research Blog

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

Author: Robin Smith (Page 1 of 7)

Pinpointing Where Durham’s Nicotine Addicts Get Their Fix

DURHAM, N.C. — It’s been five years since Durham expanded its smoking ban beyond bars and restaurants to include public parks, bus stops, even sidewalks.

While smoking in the state overall may be down, 19 percent of North Carolinians still light up, particularly the poor and those without a high school or college diploma.

Among North Carolina teens, consumption of electronic cigarettes in particular more than doubled between 2013 and 2015.

Now, new maps created by students in the Data+ summer research program show where nicotine addicts can get their fix.

Studies suggest that tobacco retailers are disproportionately located in low-income neighborhoods.

Living in a neighborhood with easy access to stores that sell tobacco makes it easier to start young and harder to quit.

The end result is that smoking, secondhand smoke exposure, and smoking-related diseases such as lung cancer, are concentrated among the most socially disadvantaged communities.

If you’re poor and lack a high school or college diploma, you’re more likely to live near a store that sells tobacco.

If you’re poor and lack a high school or college diploma, you’re more likely to live near a store that sells tobacco. Photo from Pixabay.

Where stores that sell tobacco are located matters for health, but for many states such data are hard to come by, said Duke statistics major James Wang.

Tobacco products bring in more than a third of in-store sales revenue at U.S. convenience stores — more than food, beverages, candy, snacks or beer. Despite big profits, more than a dozen states don’t require businesses to get a special license or permit to sell tobacco. North Carolina is one of them.

For these states, there is no convenient spreadsheet from the local licensing agency identifying all the businesses that sell tobacco, said Duke undergraduate Nikhil Pulimood. Previous attempts to collect such data in Virginia involved searching for tobacco retail stores by car.

“They had people physically drive across every single road in the state to collect the data. It took three years,” said team member and Duke undergraduate Felicia Chen.

Led by UNC PhD student in epidemiology Mike Dolan Fliss, the Duke team tried to come up with an easier way.

Instead of collecting data on the ground, they wrote an automated web-crawler program to extract the data from the Yellow Pages websites, using a technique called Web scraping.

By telling the software the type of business and location, they were able to create a database that included the names, addresses, phone numbers and other information for 266 potential tobacco retailers in Durham County and more than 15,500 statewide, including chains such as Family Fare, Circle K and others.

Map showing the locations of tobacco retail stores in Durham County, North Carolina.

Map showing the locations of tobacco retail stores in Durham County, North Carolina.

When they compared their web-scraped data with a pre-existing dataset for Durham County, compiled by a nonprofit called Counter Tools, hundreds of previously hidden retailers emerged on the map.

To determine which stores actually sold tobacco, they fed a computer algorithm data from more than 19,000 businesses outside North Carolina so it could learn how to distinguish say, convenience stores from grocery stores. When the algorithm received store names from North Carolina, it predicted tobacco retailers correctly 85 percent of the time.

“For example we could predict that if a store has the word “7-Eleven” in it, it probably sells tobacco,” Chen said.

As a final step, they also crosschecked their results by paying people a small fee to search for the stores online to verify that they exist, and call them to ask if they actually sell tobacco, using a crowdsourcing service called Amazon Mechanical Turk.

Ultimately, the team hopes their methods will help map the more than 336,000 tobacco retailers nationwide.

“With a complete dataset for tobacco retailers around the nation, public health experts will be able to see where tobacco retailers are located relative to parks and schools, and how store density changes from one neighborhood to another,” Wang said.

The team presented their work at the Data+ Final Symposium on July 28 in Gross Hall.

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 Counter Tools, a non-profit based in Carrboro, NC.

Writing by Robin Smith; video by Lauren Mueller and Summer Dunsmore

Sizing Up Hollywood’s Gender Gap

DURHAM, N.C. — A mere seven-plus decades after she first appeared in comic books in the early 1940s, Wonder Woman finally has her own movie.

In the two months since it premiered, the film has brought in more than $785 million worldwide, making it the highest grossing movie of the summer.

But if Hollywood has seen a number of recent hits with strong female leads, from “Wonder Woman” and “Atomic Blonde” to “Hidden Figures,” it doesn’t signal a change in how women are depicted on screen — at least not yet.

Those are the conclusions of three students who spent ten weeks this summer compiling and analyzing data on women’s roles in American film, through the Data+ summer research program.

The team relied on a measure called the Bechdel test, first depicted by the cartoonist Alison Bechdel in 1985.

Bechdel test

The “Bechdel test” asks whether a movie features at least two women who talk to each other about anything besides a man. Surprisingly, a lot of films fail. Art by Srravya [CC0], via Wikimedia Commons.

To pass the Bechdel test, a movie must satisfy three basic requirements: it must have at least two named women in it, they must talk to each other, and their conversation must be about something other than a man.

It’s a low bar. The female characters don’t have to have power, or purpose, or buck gender stereotypes.

Even a movie in which two women only speak to each other briefly in one scene, about nail polish — as was the case with “American Hustle” —  gets a passing grade.

And yet more than 40 percent of all U.S. films fail.

The team used data from the bechdeltest.com website, a user-compiled database of over 7,000 movies where volunteers rate films based on the Bechdel criteria. The number of criteria a film passes adds up to its Bechdel score.

“Spider Man,” “The Jungle Book,” “Star Trek Beyond” and “The Hobbit” all fail by at least one of the criteria.

Films are more likely to pass today than they were in the 1970s, according to a 2014 study by FiveThirtyEight, the data journalism site created by Nate Silver.

The authors of that study analyzed 1,794 movies released between 1970 and 2013. They found that the number of passing films rose steadily from 1970 to 1995 but then began to stall.

In the past two decades, the proportion of passing films hasn’t budged.

Since the mid-1990s, the proportion of films that pass the Bechdel test has flatlined at about 50 percent.

Since the mid-1990s, the proportion of films that pass the Bechdel test has flatlined at about 50 percent.

The Duke team was also able to obtain data from a 2016 study of the gender breakdown of movie dialogue in roughly 2,000 screenplays.

Men played two out of three top speaking roles in more than 80 percent of films, according to that study.

Using data from the screenplay study, the students plotted the relationship between a movie’s Bechdel score and the number of words spoken by female characters. Perhaps not surprisingly, films with higher Bechdel scores were also more likely to achieve gender parity in terms of speaking roles.

“The Bechdel test doesn’t really tell you if a film is feminist,” but it’s a good indicator of how much women speak, said team member Sammy Garland, a Duke sophomore majoring in statistics and Chinese.

Previous studies suggest that men do twice as much talking in most films — a proportion that has remained largely unchanged since 1995. The reason, researchers say, is not because male characters are more talkative individually, but because there are simply more male roles.

“To close the gap of speaking time, we just need more female characters,” said team member Selen Berkman, a sophomore majoring in math and computer science.

Achieving that, they say, ultimately comes down to who writes the script and chooses the cast.

The team did a network analysis of patterns of collaboration among 10,000 directors, writers and producers. Two people are joined whenever they worked together on the same movie. The 13 most influential and well-connected people in the American film industry were all men, whose films had average Bechdel scores ranging from 1.5 to 2.6 — meaning no top producer is regularly making films that pass the Bechdel test.

“What this tells us is there is no one big influential producer who is moving the needle. We have no champion,” Garland said.

Men and women were equally represented in fewer than 10 percent of production crews.

But assembling a more gender-balanced production team in the early stages of a film can make a difference, research shows. Films with more women in top production roles have female characters who speak more too.

“To better represent women on screen you need more women behind the scenes,” Garland said.

Dollar for dollar, making an effort to close the Hollywood gender gap can mean better returns at the box office too. Films that pass the Bechdel test earn $2.68 for every dollar spent, compared with $2.45 for films that fail — a 23-cent better return on investment, according to FiveThirtyEight.

Other versions of the Bechdel test have been proposed to measure race and gender in film more broadly. The advantage of analyzing the Bechdel data is that thousands of films have already been scored, said English major and Data+ team member Aaron VanSteinberg.

“We tried to watch a movie a week, but we just didn’t have time to watch thousands of movies,” VanSteinberg said.

A new report on diversity in Hollywood from the University of Southern California suggests the same lack of progress is true for other groups as well. In nearly 900 top-grossing films from 2007 to 2016, disabled, Latino and LGBTQ characters were consistently underrepresented relative to their makeup in the U.S. population.

Berkman, Garland and VanSteinberg were among more than 70 students selected for the 2017 Data+ program, which included data-driven projects on photojournalism, art restoration, public policy and more.

They presented their work at the Data+ Final Symposium on July 28 in Gross Hall.

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. 

Writing by Robin Smith; video by Lauren Mueller and Summer Dunsmore

Mapping Electricity Access for a Sixth of the World’s People

DURHAM, N.C. — Most Americans can charge their cell phones, raid the fridge or boot up their laptops at any time without a second thought.

Not so for the 1.2 billion people — roughly 16 percent of the world’s population — with no access to electricity.

Despite improvements over the past two decades, an estimated 780 million people will still be without power by 2030, especially in rural parts of sub-Saharan Africa, Asia and the Pacific.

To get power to these people, first officials need to locate them. But for much of the developing world, reliable, up-to-date data on electricity access is hard to come by.

Researchers say remote sensing can help.

For ten weeks from May through July, a team of Duke students in the Data+ summer research program worked on developing ways to assess electricity access automatically, using satellite imagery.

“Ground surveys take a lot of time, money and manpower,” said Data+ team member Ben Brigman. “As it is now, the only way to figure out if a village has electricity is to send someone out there to check. You can’t call them up or put out an online poll, because they won’t be able to answer.”

India at night

Satellite image of India at night. Large parts of the Indian countryside still aren’t connected to the grid, but remote sensing, machine learning could help pinpoint people living without power. Credits: NASA Earth Observatory images by Joshua Stevens, using Suomi NPP VIIRS data from Miguel Román, NASA’s Goddard Space Flight Center

Led by researchers in the Energy Data Analytics Lab and the Sustainable Energy Transitions Initiative, “the initial goal was to create a map of India, showing every village or town that does or does not have access to electricity,” said team member Trishul Nagenalli.

Electricity makes it possible to pump groundwater for crops, refrigerate food and medicines, and study or work after dark. But in parts of rural India, where Nagenalli’s parents grew up, many households use kerosene lamps to light homes at night, and wood or animal dung as cooking fuel.

Fires from overturned kerosene lamps are not uncommon, and indoor air pollution from cooking with solid fuels contributes to low birth weight, pneumonia and other health problems.

In 2005, the Indian government set out to provide electricity to all households within five years. Yet a quarter of India’s population still lives without power.

Ultimately, the goal is to create a machine learning algorithm — basically a set of instructions for a computer to follow — that can recognize power plants, irrigated fields and other indicators of electricity in satellite images, much like the algorithms that recognize your face on Facebook.

Rather than being programmed with specific instructions, machine learning algorithms “learn” from large amounts of data.

This summer the researchers focused on the unsung first step in the process: preparing the training data.

Phoenix power plant

Satellite image of a power plant in Phoenix, Arizona

Fellow Duke students Gouttham Chandrasekar, Shamikh Hossain and Boning Li were also part of the effort. First they compiled publicly available satellite images of U.S. power plants. Rather than painstakingly framing and labeling the plants in each photo themselves, they tapped the powers of the Internet to outsource the task and hired other people to annotate the images for them, using a crowdsourcing service called Amazon Mechanical Turk.

So far, they have collected more than 8,500 image annotations of different kinds of power plants, including oil, natural gas, hydroelectric and solar.

The team also compiled firsthand observations of the electrification rate for more than 36,000 villages in the Indian state of Bihar, which has one of the lowest electrification rates in the country. For each village, they also gathered satellite images showing light intensity at night, along with density of green land and other indicators of irrigated farms, as proxies for electricity consumption.

Using these data sets, the goal is to develop a computer algorithm which, through machine learning, teaches itself to detect similar features in unlabeled images, and distinguishes towns and villages that are connected to the grid from those that aren’t.

“We would like to develop our final algorithm to essentially go into a developing country and analyze whether or not a community there has access to electricity, and if so what kind,” Chandrasekar said.

Electrification map of Bihar, India

The proportion of households connected to the grid in more than 36,000 villages in Bihar, India

The project is far from finished. During the 2017-2018 school year, a Bass Connections team will continue to build on their work.

The summer team presented their research at the Data+ Final Symposium on July 28 in Gross Hall.

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 University Energy Initiative.

Writing by Robin Smith; video by Lauren Mueller and Summer Dunsmore

Science on the Trail

Duke launches free two-week girls science camp in Pisgah National Forest.

Duke launches free two-week girls science camp in Pisgah National Forest.

DURHAM, N.C. — To listen to Destoni Carter from Raleigh’s Garner High School, you’d never know she had a phobia of snails. At least until her first backpacking trip, when a friend convinced her to let one glide over her outstretched palm.

Destoni Carter

Destoni Carter from Raleigh’s Garner High School was among eight high schoolers in a new two-week camp that combines science and backpacking.

Soon she started picking them up along the trail. She would collect a couple of snails, put them on a bed of rocks or soil or leaves, and watch to see whether they were speedier on one surface versus another, or at night versus the day.

The experiment was part of a not-so-typical science class.

From June 11-23, 2017, eight high school girls from across North Carolina and four Duke Ph.D. students left hot showers and clean sheets behind, strapped on their boots and packs, and ventured into Pisgah National Forest.

For the high schoolers, it was their first overnight hike. They experienced a lot of things you might expect on such a trip: Hefty packs. Sore muscles. Greasy hair. Crusty socks. But they also did research.

The girls, ages 15-17, were part of a new free summer science program, called Girls on outdoor Adventure for Leadership and Science, or GALS. Over the course of 13 days, they learned ecology, earth science and chemistry while backpacking with Duke scientists.

Duke ecology Ph.D. student Jacqueline Gerson came up with the idea for the program. “Backpacking is a great way to get people out of their comfort zones, and work on leadership development and teambuilding,” said Gerson, who also teamed up with co-instructors Emily Ury, Alice Carter and Emily Levy, all Ph.D. students in ecology or biology at Duke.

Marwa Hassan of Riverside High School in Durham studying stream ecology as part of a two-week summer science program in Pisgah National Forest. Photo by Savannah Midgette.

Marwa Hassan of Riverside High School in Durham studying stream ecology as part of a two-week summer science program in Pisgah National Forest. Photo by Savannah Midgette.

The students hauled 30- to 40-pound loads on their backs for up to five miles a day, through all types of weather. For the first week and a half they covered different themes each day: evolution, geology, soil formation, aquatic chemistry, contaminants. Then on the final leg they chose an independent project. Armed with hand lenses, water chemistry test strips, measuring tapes and other gear, each girl came up with a research question, and had two days to collect and analyze the data.

Briyete Garcia-Diaz of Kings Mountain High School surveyed rhododendrons and other trees at different distances from streambanks to see which species prefer wet soils.

Marwa Hassan of Riverside High School in Durham waded into creeks to net mayfly nymphs and caddisfly larvae to diagnose the health of the watershed.

Savannah Midgette of Manteo High School counted mosses and lichens on the sides of trees, but she also learned something about the secret of slug slime.

“If you lick a slug it makes your tongue go numb. It’s because of the protective coating they have,” Midgette said.

High schoolers head to the backcountry to learn the secret of slug slime and other discoveries of science and self in new girls camp

High schoolers head to the backcountry to learn the secret of slug slime and other discoveries of science and self in new girls camp

The hiking wasn’t always easy. On their second day they were still hours from camp when a thunderstorm rolled in. “We were still sore from the previous day. It started pouring. We were soaking wet and freezing. We did workouts to keep warm,” Midgette said.

At camp they took turns cooking. They stir fried chicken and vegetables and cooked pasta for dinner, and somebody even baked brownies for breakfast. Samantha Cardenas of Charlotte Country Day School discovered that meals that seem so-so at home taste heavenly in the backcountry.

“She would be like, ugh, chicken in a can? And then eat it and say: ‘That’s the most amazing thing I’ve ever had,’” said co-instructor Emily Ury.

Savannah Midgette and Briyete Garcia-Diaz drawing interactions within terrestrial systems as part of a new free summer science program called Girls on outdoor Adventure for Leadership and Science, or GALS. Learn more at https://sites.duke.edu/gals/.

Savannah Midgette and Briyete Garcia-Diaz drawing interactions within terrestrial systems as part of a new free summer science program called Girls on outdoor Adventure for Leadership and Science, or GALS. Learn more at https://sites.duke.edu/gals/.

The students were chosen from a pool of over 90 applicants, said co-instructor Emily Levy. There was no fee to participate in the program. Thanks to donations from Duke Outdoor Adventures, Project WILD and others, the girls were able to borrow all the necessary camping gear, including raincoats, rain pants, backpacks, tents, sleeping bags, sleeping pads and stoves.

The students presented their projects on Friday, June 23 in Environment Hall on Duke’s West Campus. Standing in front of her poster in a crisp summer dress, Destoni Carter said going up and down steep hills was hard on her knees. But she’s proud to have made it to the summit of Shining Rock Mountain to see the stunning vistas from the white quartz outcrop near the top.

“I even have a little bit of calf muscle now,” Carter said.

Funding and support for GALS was provided by Duke’s Nicholas School of the Environment, Duke ecologist Nicolette Cagle, the Duke Graduate School and private donors via GoFundMe.

2017 GALS participants (left to right): Emily Levy of Duke, Destoni Carter of Garner High School, Zyrehia Polk of East Mecklenburg High School, Rose DeConto of Durham School of the Arts, Briyete Garcia-Diaz of Kings Mountain High School, Marwa Hassan of Riverside High School, Jackie Gerson of Duke, Daiana Mendoza of Harnett Central High School, Savannah Midgette of Manteo High School, Samantha Cardenas of Charlotte Country Day School and Alice Carter of Duke.

2017 GALS participants (left to right): Emily Levy of Duke, Destoni Carter of Garner High School, Zyrehia Polk of East Mecklenburg High School, Rose DeConto of Durham School of the Arts, Briyete Garcia-Diaz of Kings Mountain High School, Marwa Hassan of Riverside High School, Jackie Gerson of Duke, Daiana Mendoza of Harnett Central High School, Savannah Midgette of Manteo High School, Samantha Cardenas of Charlotte Country Day School and Alice Carter of Duke.

 

Immerse Yourself in Virtual Reality on the Quad

Open since September 2016, the Virtual Reality Room on the first floor lounge of Edens 1C allows students to experience virtual reality using the HTC Vive headset and controllers.

DURHAM, N.C. — The virtual reality headset looked like something out of a science fiction film. It was tethered by a long cable to a glass-encased PC, which in turn was connected to thick hoses filled with glowing blue coolant.

I slipped the mask over my head and was literally transported to another world.

In real life, I was in the lower level of Edens residence hall testing out the recently opened BoltVR gaming room during an event hosted by the Duke Digital Initiative (DDI). Virtual reality is one of the technologies that DDI is exploring for its potential in teaching and learning.

Rebekkah Huss shoots invaders with a virtual bow and arrow in Duke's newest virtual reality space.

Rebekkah Huss shoots invaders with a virtual bow and arrow in Duke’s newest virtual reality space. Open to students 4 p.m. to 10 p.m. on weekdays, noon to midnight on weekends.

BoltVR is a virtual reality space outfitted with the immersive room-scale technology of the HTC Vive, an $800 gaming system consisting of the headset, hand-held controllers and motion sensors in the room. The VR experience is a new addition to the Bolt gaming suite that opened in 2015 for Duke students.

Once I had the headset on, suddenly the bare walls and carpet were replaced by the yellow lined grid of the Holodeck from Star Trek. It was like nothing I’d ever seen. This is like the home screen for the gaming system, explained  Mark-Everett McGill the designer of the BoltVR game room, as he scrolled through the more than 70 downloaded VR experiences on the BoltVR online account at Steam.

McGill chose a story experience so that I could adjust to being able to move around physical objects in a virtual space.

It was like the floor melted away. On a tiny asteroid in front of me The Little Prince and his rose played out their drama from the cover of the classic children’s book. The stars surrounded me and I tilted my head back to watch a giant planet fly over.

I could walk around the prince’s tiny asteroid and inspect the little world from all angles, but I found it disorienting to walk with normal stability while my eyes told me that I was floating in space. The HTC Vive has a built-in  guidance system called the Chaperone that used a map of the room to keep me from crashing into the walls, I still somehow managed to bump a spectator.

“A lot of people get motion sickness when they use VR because your eyes are sensing the movement but your ears are telling you, you aren’t doing anything.” said, McGill.

Lucky for me, I have a strong stomach and suffered no ill effects while wearing the headset. The HTC Vive also helps counteract motion sickness because is room scale design allows for normal walking and movement.

There was however, one part of the experience that felt very odd, and that was the handheld controllers. The controllers  are tracked by wall-mounted sensors so they show up really well in the VR headset. The problem was that in the titles I played my hands and body were invisible to me.

The headset and controller themselves are incredibly sensitive and accurate. I think most people would intuitively understand how to use them, especially if they have a gaming background, but I missed having the comfort of my own arms. So while the VR worlds are visually believable and the technology powering them is absolutely fascinating, there is still lots of room for new innovations.

Once I started playing games though, I no longer cared about the limitations of the tech because I was having so much fun!

The most popular student choice in the BoltVR is a subgame of The Lab by Valve, it’s a simple tower defense game where the player uses a bow and arrow to shoot little 2D stickmen and stop their attack.

Everything about using the bow felt pretty realistic like loading arrows, and using angles to control the trajectory of a shot. There was even a torch that I used to light my arrow on fire before launching it at an attacker. With unlimited ammunition, I happily guarded my tower from waves of baddies until I finally had to let someone else have a turn.

To learn more about VR experiences for teaching and learning at Duke, join the listserv at https://lists.duke.edu/sympa/subscribe/vr2learn.

Post by Rebekkah Huss

Post by Rebekkah Huss

Lemur Research Gets a Gut Check

Baby Coquerel’s sifaka

Clinging to her mom, this baby Coquerel’s sifaka represents the only lemur species at the Duke Lemur Center known to fall prey to cryptosporidium, a microscopic parasite that causes diarrhea that can last for a week or more. The illness wipes out much of the animals’ gut microbiome, researchers report, but fecal transplants can help them recover. Photo by David Haring, Duke Lemur Center.

DURHAM, N.C. — “Stool sample collector” is not a glamorous way to introduce oneself at a party. But in the course of their research, gut microbiologists Erin McKenney and Lydia Greene have spent a lot of time waiting for animals to relieve themselves.

They estimate they have hundreds of vials of the stuff, from a dozen primate species including lemurs, baboons and gorillas, sitting in freezers on the Duke University campus.

The researchers aren’t interested in the poop per se, but in the trillions of bacteria inhabiting the gastrointestinal tract, where the bugs help break down food, produce vitamins and prevent infection.

A few years ago, McKenney and Greene started collecting stool samples at the Duke Lemur Center to see how the microbial makeup of lemurs’ guts varies from birth to weaning, and as their diets change over the seasons. And what happens when they get sick?

Illustration of Cryptosporidium, a widespread intestinal parasite that causes diarrhea in people, pets, livestock and wildlife worldwide. Courtesy of the U.S. Centers for Disease Control.

Illustration of Cryptosporidium, a widespread intestinal parasite that causes diarrhea in people, pets, livestock and wildlife worldwide. Courtesy of the U.S. Centers for Disease Control.

Between 2013 and 2016, ten of the lemurs they were studying contracted cryptosporidium, or “crypto” for short, a waterborne parasite that causes diarrhea in people, pets, livestock and wildlife worldwide.

All of the infected animals were Coquerel’s sifakas — the only lemur species out of roughly 20 at the Duke Lemur Center known to fall prey to the parasite — and most of them were under five years old when they fell ill.

Animals that tested positive were moved into separate holding areas away from other animals and visitors. Keepers wore protective suits, gloves, face masks and booties while working in the animals’ enclosures to prevent infection.

All of the animals eventually recovered. Along the way, six of the affected animals were treated with antibiotics, and three were also fed a slurry of saline and feces from a healthy relative.

McKenney and Greene collected stool samples before, during and after infection for up to two months. They used a technique called 16S ribosomal RNA sequencing to identify the types of bacteria in the samples based on their genes, and compared the results with those of 35 unaffected individuals.

In a healthy gut microbiome, “good” bacteria in the gut compete with “bad” microbes for space and nutrients, and secrete substances that inhibit their growth.

The guts of sick and recovering sifakas are host to a very different assortment of microbes than those of unaffected animals, the researchers found.

Not surprisingly, both crypto infection, and antibiotic treatment, wiped out much of the animals’ gut flora — particularly the bacterial groups Bifidobacterium, Akkermansia, Succinivibrio and Lachnospiraceae.

Even after the infections cleared, most animals took another several weeks to stabilize and return to normal levels of gut biodiversity, with younger animals taking longer to recover.

The only animals that made a full comeback within the study period were those that received a fecal transplant, suggesting that the treatment can help restore gut bacterial diversity and speed recovery.

The patterns of gut recolonization following crypto infection mirrored those seen from birth to weaning, said McKenney, now a postdoctoral researcher at North Carolina State University.

The researchers hope their findings will help control and prevent crypto outbreaks in captive primates. Because lemurs are more closely related to humans than lab mice are, the research could also help scientists understand how the gut microbiome protects humans from similar infections and facilitates recovery.

“Thanks to bioinformatics and advances in sequencing, the microbiome gives us a window into the health of these animals that we’ve never had before,” said Greene, a graduate student in ecology at Duke.

They published their findings June 15, 2017, in the journal Microbial Ecology in Health and Disease.

Duke evolutionary anthropology professors Christine Drea and Anne Yoder were senior authors on this study. This research was supported by the National Science Foundation (1455848) and the Duke Lemur Center Directors Fund.

CITATION:  “Down for the Count: Cryptosporidium Infection Depletes Gut Microbiota in Coquerel’s Sifakas,” Erin McKenney, Lydia Greene, Christine Drea and Anne Yoder. Microbial Ecology in Health and Disease, June 15, 2017. http://dx.doi.org/10.1080/16512235.2017.1335165

Post by Robin Smith, science writer, Office of News & Communications

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