Duke Research Blog

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

Category: Global Health (Page 1 of 9)

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

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

Students Share Research Journeys at Bass Connections Showcase

From the highlands of north central Peru to high schools in North Carolina, student researchers in Duke’s Bass Connections program are gathering data in all sorts of unique places.

As the school year winds down, they packed into Duke’s Scharf Hall last week to hear one another’s stories.

Students and faculty gathered in Scharf Hall to learn about each other’s research at this year’s Bass Connections showcase. Photo by Jared Lazarus/Duke Photography.

The Bass Connections program brings together interdisciplinary teams of undergraduates, graduate students and professors to tackle big questions in research. This year’s showcase, which featured poster presentations and five “lightning talks,” was the first to include teams spanning all five of the program’s diverse themes: Brain and Society; Information, Society and Culture; Global Health; Education and Human Development; and Energy.

“The students wanted an opportunity to learn from one another about what they had been working on across all the different themes over the course of the year,” said Lori Bennear, associate professor of environmental economics and policy at the Nicholas School, during the opening remarks.

Students seized the chance, eagerly perusing peers’ posters and gathering for standing-room-only viewings of other team’s talks.

The different investigations took students from rural areas of Peru, where teams interviewed local residents to better understand the transmission of deadly diseases like malaria and leishmaniasis, to the North Carolina Museum of Art, where mathematicians and engineers worked side-by-side with artists to restore paintings.

Machine learning algorithms created by the Energy Data Analytics Lab can pick out buildings from a satellite image and estimate their energy consumption. Image courtesy Hoël Wiesner.

Students in the Energy Data Analytics Lab didn’t have to look much farther than their smart phones for the data they needed to better understand energy use.

“Here you can see a satellite image, very similar to one you can find on Google maps,” said Eric Peshkin, a junior mathematics major, as he showed an aerial photo of an urban area featuring buildings and a highway. “The question is how can this be useful to us as researchers?”

With the help of new machine-learning algorithms, images like these could soon give researchers oodles of valuable information about energy consumption, Peshkin said.

“For example, what if we could pick out buildings and estimate their energy usage on a per-building level?” said Hoël Wiesner, a second year master’s student at the Nicholas School. “There is not really a good data set for this out there because utilities that do have this information tend to keep it private for commercial reasons.”

The lab has had success developing algorithms that can estimate the size and location of solar panels from aerial photos. Peshkin and Wiesner described how they are now creating new algorithms that can first identify the size and locations of buildings in satellite imagery, and then estimate their energy usage. These tools could provide a quick and easy way to evaluate the total energy needs in any neighborhood, town or city in the U.S. or around the world.

“It’s not just that we can take one city, say Norfolk, Virginia, and estimate the buildings there. If you give us Reno, Tuscaloosa, Las Vegas, Pheonix — my hometown — you can absolutely get the per-building energy estimations,” Peshkin said. “And what that means is that policy makers will be more informed, NGOs will have the ability to best service their community, and more efficient, more accurate energy policy can be implemented.”

Some students’ research took them to the sidelines of local sports fields. Joost Op’t Eynde, a master’s student in biomedical engineering, described how he and his colleagues on a Brain and Society team are working with high school and youth football leagues to sort out what exactly happens to the brain during a high-impact sports game.

While a particularly nasty hit to the head might cause clear symptoms that can be diagnosed as a concussion, the accumulation of lesser impacts over the course of a game or season may also affect the brain. Eynde and his team are developing a set of tools to monitor both these impacts and their effects.

A standing-room only crowd listened to a team present on their work “Tackling Concussions.” Photo by Jared Lazarus/Duke Photography.

“We talk about inputs and outputs — what happens, and what are the results,” Eynde said. “For the inputs, we want to actually see when somebody gets hit, how they get hit, what kinds of things they experience, and what is going on in the head. And the output is we want to look at a way to assess objectively.”

The tools include surveys to estimate how often a player is impacted, an in-ear accelerometer called the DASHR that measures the intensity of jostles to the head, and tests of players’ performance on eye-tracking tasks.

“Right now we are looking on the scale of a season, maybe two seasons,” Eynde said. “What we would like to do in the future is actually follow some of these students throughout their career and get the full data for four years or however long they are involved in the program, and find out more of the long-term effects of what they experience.”

Kara J. Manke, PhD

Post by Kara Manke

Bass Connections and GHANDI – Understanding Disability from a Global Perspective

Duke prides itself on being a research institution that is not only intellectually curious, but also extremely interdisciplinary. Through Duke’s Bass Connections initiative, students and faculty come together in project teams that tackle complex issues using multiple disciplines and approaches. The program held its annual fair last week to showcase its work and to get new students connected with these exciting projects.

How does it work?

Graduate students, undergraduates, and faculty members apply for a research project in any of these five areas: Brain and Society, Information Society & Culture, Global Health, Education & Development, and Energy. Once accepted, group members work on a year-long research project, that often includes a field work component. One project in particular that combines many disciplines and interests to address an issue of global importance GANDHI, a Global Health project that studies disability from multiple cultural perspectives.

What is GANDHI?

GANDHI team members meet with Dr. Rune Simeonsson at UNC to discuss the WHO ICF-CY (International Classification of Functioning – Children and Youth), a document he helped co-write that provides a framework for diagnosing and addressing disability.

The Global Alliance on Disease and Health Innovation (GANDHI) was created in 2016 to support disabled individuals by providing them with the community reintegration tools necessary to live a healthy, comfortable life. Yukhai Lin, a Duke undergrad and GANDHI team member, shared that many hospital systems are not good at helping those the disabled reintegrate themselves in their community, and often forget about their patients after they are released. The research team recognized this flaw, and began a thorough data collection process to understand the reason for this lack of care. In the fall of 2016, team members took a seminar course, “Living with Disability Around the Globe”, in which they were paired with global partners in ten different countries to examine disability from a more specific context. In this interdisciplinary class, team members not only strengthened their knowledge of disability and its implications on global societies, but they were also able to develop strong research skills, for they ultimately synthesized their findings by creating a thorough comparison of disability in each of the countries studied.

The team also attended a conference in New Orleans to network with organizations that were conducting similar research. Lin said she interviewed doctors from The Netherlands, as well as leaders of influential health organizations to holistically understand the issues that come with helping the disabled. The team hopes to present their findings at a forum this spring, and, like many other Bass Connection projects, will continue throughout the 2017-2018 academic year. They encourage all to apply, and hope to broaden the scope of their research by adding countries in Southeast Asia and creating new opportunities for fieldwork. Some eager students have already showed interest in going to China to interview families with disabled members, says Lin.

Other Bass Connections projects at the fair spread across all disciplines, ranging from the development of effective chemotherapy drugs to the study of urban development in cities across the globe. But, what all projects share in common is a strong emphasis on research that is hands-on, collaborative, and relevant to society.

 

Post by Lola Sanchez-Carrion

Using the Statistics of Disorder to Unravel Real-World Chaos

What do election polls, hospital records, and the Syrian conflict have in common? How can a hospital use a patient’s vital signs to calculate their risk of cardiac arrest in real time?

Duke statistical science professor Rebecca Steorts

Duke statistical science professor Rebecca Steorts

Statistician Rebecca Steorts is developing advanced data analysis methods to answer these questions and other pressing real-world problems. Her research has taken her from computer science to biostatistics and hospital care to human rights.

One major focus of Steorts’ research has been estimating death counts in the Syrian civil war. She is working with her research group at Duke and the Human Rights Data Analysis Group (https://hrdag.org/) on combining databases of death records into a single master list of deaths in the conflict, a task known as record linkage.

“The key problem of record linkage is this: you have this duplicated information, how do you remove it?” explained Steorts. For example, journalists from different organizations might independently record the same death in their databases. Those duplicates have to be removed before an accurate death toll can be determined.

At first glance, this might seem like an easy task. But typographic errors, missing information, and inconsistent record-keeping make hunting for duplicates a complex and time consuming problem; a simple algorithm would require days to sort through all the records. So Steorts and her collaborators designed software to sift through the different databases using powerful machine learning techniques. In 2015, she was named one of MIT Technology Review’s 35 Innovators Under 35 for her work on the Syrian conflict. She credits a number of colleagues and students for their contributions to the project, including Anshumali Shrivastava (Rice University), Megan Price (HRDAG), Brenda Betancourt and Abbas Zaid (Duke University), Jeff Miller (Harvard Biostatistics, formerly Duke University), Hanna Wallach (Microsoft Research), and Giacomo Zanella (University of Bocconi and Visitor of Duke University in 2016).

Steorts’ work towards estimating death counts in the Syrian conflict is still ongoing, but human rights isn’t the only field that she plans to study. “I think of my work as very interdisciplinary,” she said. “For me, it’s all about the applications.”

Recently, Steorts, colleague Ben Goldstein, and students Reuben McCreanor and Angie Shen have been applying statistical methods to medical data from the Duke healthcare system. Her ultimate goal is to find techniques that can be used for many different applications and data sets.

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Guest post by Angela Deng, North Carolina School of Science and Math, Class of 2017

José Jerónimo – Innovations in Cervical Cancer Screening

José Jerónimo and his team are transforming the face of cervical cancer screening. Jerónimo is a physician and senior advisor for the women’s cancers branch of PATH, an international nonprofit organization that uses innovative technologies to improve health outcomes in developing countries. Jerónimo, who’s work at PATH has facilitated the prevention and treatment of cervical cancer for thousands in the developing world, spoke at the Duke Institute for Global Health on Dec. 2.

Cervical cancer testing has been a point of conflict in the medical community for quite some time now, for the pap smear — for many years, the only test available to detect cervical cancer — is not very sensitive to abnormal tissue. Since skepticism with the pap smear arose a few decades ago, doctors like Jerónimo have been working tirelessly to find more effective screening strategies.

José Gerónimo, Peruvian physician and public health advocate, received his specialty training in gynecologic oncology at the National Cancer Institute in Peru.

José Jerónimo, Peruvian physician and public health advocate, received his specialty training in gynecologic oncology at the National Cancer Institute in Peru.

Cervical cancer can be acquired through the presence of HPV (human papilloma virus). Chronic infections of HPV have been proven to increase the likelihood of contracting cervical cancer, so developing primary prevention initiatives to avoid developing HPV to begin with are essential to decrease the prevalence of cervical cancer. HPV testing, unlike the pap smear, can be self-collected and does not require the complex, expensive machinery that the pap smear does. Initial self-sampling studies in India, Uganda, and Nicaragua indicated a willingness by the female community to self-test, so long as sanitary and private conditions were provided.

Studies in the Jujuy province of Argentina indicated that community health workers played a key role in facilitating the self-sampling process. When the health workers differed locals to clinics or sent them to facilities for testing, only 20 percent actually went. But, when they brought the self-sampling tests to locals’ homes directly, testing was above 80 percent. The easy accessibility of self-sampling, along with encouragement by local health volunteers, clearly showed that self-sampling was much more effective.

A group of female community health workers in Lima, Peru, educating the community about HPV testing.

Jerónimo’s current work focuses on strengthening government screening systems for HPV that are already in place. By helping ministries introduce and scale up the testing, he and others at PATH hope to decrease HPV and cervical cancer rates.

But, it goes beyond testing. Jerónimo emphasizes the need for evaluation and follow-up mechanisms after testing positive. Although testing efforts have improved significantly, the treatment provided after for those who have tested positive is still lagging. Jerónimo claims that much of this is due to minimal efforts by the local governments to really follow through beyond the testing phase.

PATH is looking for innovative ways to treat HPV that are inexpensive and effective. They recently developed their own version of the thermal coagulator, a probe that treats infected tissue using heat. Their design runs on a battery, rather than needing constant electricity, and uses a progressive heating mechanism that is only activated upon touching the cervix. There is still progress to be made, in both testing and treatment of HPV and cervical cancer, but through efforts by both local and international communities, Jerónimo shows us that is possible.

lola_sanchez_carrion_100hedPost by Lola Sanchez-Carrion

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