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Author: Robin Smith Page 6 of 9

Lemur Poop Could Pinpoint Poaching Hotspots

DNA detective work aims to map the illegal pet lemur trade in Madagascar

Local business owners in Madagascar sometimes use ring-tailed lemurs to sell photo ops to tourists. Tourists visiting the country can easily support the illegal pet lemur trade unknowingly by paying to touch or have their picture taken with a lemur. Photo courtesy of the Pet Lemur Survey project (www.petlemur.com)

Businesses in Madagascar sometimes use ring-tailed lemurs to sell photo ops to tourists. Tourists visiting the country can easily support the illegal pet lemur trade unknowingly by paying to touch or have their picture taken with a lemur. Photo courtesy of the Pet Lemur Survey project (www.petlemur.com)

When Tara Clarke went to Madagascar this summer, she packed what you might expect for a trip to the tropics: sunscreen, bug spray. But when she returned seven weeks later, her carry-on luggage contained an unusual item: ten pounds of lemur droppings.

“That’s a lot of poop,” Clarke said.

A visiting assistant professor of evolutionary anthropology at Duke, Clarke and colleagues are analyzing DNA from lemur feces to pinpoint poaching hotspots in Madagascar’s pet lemur trade.

Pet lemurs are illegal in Madagascar, the only place on Earth where lemurs — the world’s most endangered primates — live in the wild.

More than 28,000 lemurs were taken from the wild and kept as pets on the island between 2010 and 2013 alone, surveys suggest.

Many pet lemurs are captured as babies, separated from their mothers and sold for less than two dollars apiece to hotels and restaurants to lure tourists, who pay to touch the animals and have their photo taken with them.

Anyone caught removing lemurs from the forest, selling them, or keeping them without a government permit can be fined and sentenced to up to two years in jail. But the laws are difficult to enforce, especially in remote villages, where rural poverty is common and law enforcement personnel may be few.

Clarke (left) and LaFleur (right) co-direct a nonprofit called Lemur Love that aims to protect ring-tailed lemurs and their habitat in southern Madagascar. Follow them at https://www.facebook.com/lemurloveinc/.

Primatologists Tara Clarke (left) and Marni LaFleur (right) co-direct a nonprofit called Lemur Love that aims to protect ring-tailed lemurs and their habitat in southern Madagascar. Follow them at https://www.facebook.com/lemurloveinc/.

In 2011, Malagasy officials began confiscating pet ring-tailed lemurs, the most popular species in the pet lemur trade, and handing them over to a non-governmental organization in southwestern Madagascar called Renalia, home of the Lemur Rescue Center.

About two dozen ring-tailed lemurs are currently being rehabilitated there in the hopes that many of them will one day be reintroduced to the wild.

But rounding up all the lemurs held illegally in private hands and taking them in would be nearly impossible, Clarke said. “There just isn’t a facility big enough, or the funding or the manpower.”

If we can figure out where the animals are being taken from the forest, Clarke said, we might be able to target those poaching hotspots and try to prevent them from becoming pets in the first place through education and outreach initiatives.

Ring-tailed lemurs live in southern Madagascar, an island nation off the coast of Africa. Map by Alex Dunkel.

Ring-tailed lemurs live in southern Madagascar, an island nation off the coast of Africa. Map by Alex Dunkel.

This summer, Clarke and biological anthropologist Marni LaFleur of the University of California, San Diego began collecting baseline samples of ring-tailed lemur poop from national parks and protected areas around southern and southwestern Madagascar, where ring-tailed lemurs live in the wild. They also collected samples from 19 ex-pets at the Lemur Rescue Center.

The samples are being shipped to the Primate Molecular Ecology Laboratory at Hunter College in New York for analysis.

There, with help from lab director Andrea Baden, the team will use DNA extracted from the wild samples to build a map of variation in ring-tailed lemur genes across their range.

By analyzing the DNA of the ex-pets housed at the Lemur Rescue Center and comparing it with their map, the researchers hope to pinpoint or rule out where the animals were first taken from the wild.

In addition to collecting feces, Clarke and LaFleur also worked with local guides to count ring-tailed lemurs in their natural habitat and estimate how many are left.

The pet trade isn’t the only threat to lemur survival. Over the past 40 years, logging, slash-and-burn agriculture, and charcoal production have reduced forest cover in southwestern Madagascar by nearly half.

“Their habitat is disappearing,” said Clarke, who has conducted field research in Madagascar since 2004.

Their 2016 census suggests that fewer than 2000 ring-tailed lemurs remain in the wild — a significant decline compared with the last census in 2000, when ring-tailed lemurs were estimated based on satellite images to number more than 750,000.

In every town the researchers visited they also passed out hundreds of posters about the illegal pet lemur trade as part of a nationwide education campaign called “Madagascar’s Treasure: Keeping Lemurs Wild,” which aims to raise interest in protecting the few wild populations that remain.

Lemur protection programs such as theirs can also benefit other threatened wildlife that share the lemurs’ forest habitat, such as the giant-striped mongoose and the radiated tortoise.

Keeping lemurs as pets isn’t unique to Madagascar. “There are thousands of lemurs in private hands in the U.S. too,” said Andrea Katz, curator at the Duke Lemur Center. Every year, the Duke Lemur Center gets phone calls from people in the U.S. looking for answers to questions about their pet lemurs’ health or behavioral problems.

“In some states it’s legal to have a pet lemur,” Clarke said. “You can find them online. You can find them in pet stores. A lot of times what happens is they reach sexual maturity and they get aggressive, and that’s when people call a zoo or a sanctuary.”

“Because you can see ring-tailed lemurs in zoos and movies people don’t think that they need our help. They don’t believe that they’re endangered. We’re trying to change that view,” Clarke said.

This research was supported by grants from the Margot Marsh Biodiversity Foundation and Conservation International’s Primate Action Fund.

These crowned lemurs are among more than 30 of the roughly 100 known lemur species in Madagascar that are affected by the pet lemur trade. Explore interactive data visualizations of pet lemur sightings in Madagascar by species, date and location at http://www.petlemur.com/data-visualization.html. Photo courtesy of the Pet Lemur Survey project (www.petlemur.com)

These crowned lemurs are among more than 30 of the roughly 100 known lemur species in Madagascar that are affected by the pet lemur trade. Explore interactive data visualizations of pet lemur sightings in Madagascar by species, date and location at http://www.petlemur.com/data-visualization.html. Photo courtesy of the Pet Lemur Survey project (www.petlemur.com)

Robin Smith

 

Post by Robin A. Smith

In Sync

DiTalia2The dividing red spots in this time-lapse video belong to a busily developing fruit fly embryo. A fruit fly egg can divide into some 6,000 cells in just two hours —  faster division than cancer tumors. To watch them action, graduate student Victoria Deneke and assistant professor Stefano Di Talia tagged the nuclei with a protein that glows red. In a recent study, they show that the cells coordinate their rapid divisions via waves of protein activity that spread across the embryo. The waves help ensure that all the cells enter the next stage of development at the same time.

Duke graduate student Victoria Deneke has been awarded an international student research fellowship from the Howard Hughes Medical Institute.

Duke graduate student Victoria Deneke has been awarded an international student research fellowship from the Howard Hughes Medical Institute.

Starting September 2016, Deneke became one of 20 graduate students from 14 countries selected for an international student research fellowship from the Howard Hughes Medical Institute.

Three-year fellowship is designed to support outstanding international graduate students studying in the United States who are ineligible for fellowships or training grants through U.S. federal agencies.

Born in El Salvador, Deneke earned her undergraduate degree in chemical engineering from the University of Notre Dame before joining Stefano Di Talia’s at Duke in 2013.

Fellows must be nominated by their institution; participation is by invitation only. Deneke is only the second student at Duke to receive an HHMI International Student Research Fellowship since the program was established in 2011.

CITATION:  “Waves of Cdk1 Activity in S Phase Synchronize the Cell Cycle in Drosophila Embryos,” Victoria Deneke, Anna Melbinger, Massimo Vergassola and Stefano Di Talia. Developmental Cell, August 2016. http://dx.doi.org/10.1016/j.devcel.2016.07.023

Is Durham's Revival Pricing Some Longtime Residents Out?

When a 2015 national report on gentrification released its results for the nation’s 50 largest cities, both Charlotte and Raleigh — North Carolina’s top two biggest cities — made the list.

The result was a collection of maps and tables indicating whether various neighborhoods in each city had gentrified or not, based on changes in home values and other factors from 1990 to the present.

Soon Durham residents, business owners, policy wonks and others will have easy access to similar information about their neighborhoods too, thanks to planned updates to a web-based mapping tool called Durham Neighborhood Compass.

Two Duke students are part of the effort. For ten weeks this summer, undergraduates Anna Vivian and Vinai Oddiraju worked with Neighborhood Compass Project Manager John Killeen and Duke economics Ph.D. student Olga Kozlova to explore real-world data on Durham’s changing neighborhoods as part of a summer research program called Data+.

As a first step, they looked at recent trends in the housing market and business development.

Photo by Mark Moz.

Durham real estate and businesses are booming. A student mapping project aims to identify the neighborhoods at risk of pricing longtime residents out. Photo by Mark Moz.

Call it gentrification. Call it revitalization. Whatever you call it, there’s no denying that trendy restaurants, hotels and high-end coffee shops are popping up across Durham, and home values are on the rise.

Integrating data from the Secretary of State, the Home Mortgage Disclosure Act and local home sales, the team analyzed data for all houses sold in Durham between 2010 and 2015, including list and sale prices, days on the market, and owner demographics such as race and income.

They also looked at indicators of business development, such as the number of business openings and closings per square mile.

A senior double majoring in physics and art history, Vivian brought her GIS mapping skills to the project. Junior statistics major Oddiraju brought his know-how with computer programming languages.

To come up with averages for each neighborhood or Census block group, they first converted every street address in their dataset into latitude and longitude coordinates on a map, using a process called geocoding. The team then created city-wide maps of the data using GIS mapping software.

One of their maps shows the average listing price of homes for sale between 2014 and 2015, when housing prices in the area around Duke University’s East Campus between Broad Street and Buchanan Boulevard went up by $40,000 in a single year, the biggest spike in the city

Their web app shows that more businesses opened in downtown and in south Durham than in other parts of the city.

Duke students are developing a web app that allows users to see the number of new businesses that have been opening across Durham. The data will appear in future updates to a web-based mapping tool called Durham Neighborhood Compass.

They also used a programming language called “R” to build an interactive web app that enables users to zoom in on specific neighborhoods and see the number of new businesses that opened, compare a given neighborhood to the average for Durham county as a whole, or toggle between years to see how things changed over time.

The Durham Neighborhood Compass launched in 2014. The tool uses data from local government, the Census Bureau and other state and federal agencies to monitor nearly 50 indicators related to quality of life and access to services.

When it comes to gentrification, users can already track neighborhood-by-neighborhood changes in race, household income, and the percentage of households that are paying 30 percent or more of their income for housing — more than many people can afford.

Vivian and Oddiraju expect the scripts and methods they developed will be implemented in future updates to the tool.

When they do, the team hopes users will be able to compare the average initial asking price to the final sale price to identify neighborhoods where bidding has been the highest, or see how fast properties sell once they go on the market — good indicators of how hot they are.

Visitors will also be able to compare the median income of people buying into a neighborhood to that of the people that already live there. This will help identify neighborhoods that are at risk of pricing out residents, especially renters, who have called the city home.

Vivian and Oddiraju were among more than 60 students who shared preliminary results of their work at a poster session on Friday, July 29 in Gross Hall.

Vivian plans to continue working on the project this fall, when she hopes to comb through additional data sets they didn’t get to this summer.

“One that I’m excited about is the data on applications for renovation permits and historic tax credits,” Vivian said.

She also hopes to further develop the web app to make it possible to look at multiple variables at once. “If sale prices are rising in areas where people have also filed lots of remodeling permits, for example, that could mean that they’re flipping those houses,” Vivian said.

Data+ is sponsored by the Information Initiative at Duke, the Social Sciences Research Institute and Bass Connections. Additional funding was provided by the National Science Foundation via a grant to the departments of mathematics and statistical science.

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Writing by Robin Smith; video by Sarah Spencer and Ashlyn Nuckols

Taking Math Beyond the Blackboard

https://youtu.be/cZVxTeUeez8

Most days, math graduate student Veronica Ciocanel spends her time modeling how frog eggs go from jelly-like blobs to tiny tadpoles having a well-defined front and back, top and bottom. But for a week this summer, she used some of the same mathematical tools from her Ph.D. research at Brown to help a manufacturing company brainstorm better ways to filter nasty-smelling pollutants from industrial exhaust fumes.

Math professor Ryan Pellico of Trinity College took a similar leap. Most of his research aims to model suspension bridges that twist and bounce to the point of collapse. But he spent a week trying to help a defense and energy startup devise better ways to detect landmines using ground-penetrating radar.

Ciocanel and Pellico are among more than 85 people from across the U.S., Canada and the U.K. who met at Duke University June 13-17 for a five-day problem-solving workshop for mathematicians, scientists and engineers from industry and academia.

The concept got its start at Oxford University in 1968 and has convened 32 times. Now the Mathematical Problems in Industry workshop (MPI) takes place every summer at a different university around the U.S. This is the first time Duke has hosted the event.

The participants’ first task was to make sense of the problems presented by the companies and identify areas where math, modeling or computer simulation might help.

One healthcare services startup, for example, was developing a smartphone app to help asthma sufferers and their doctors monitor symptoms and decide when patients should come in for care. But the company needed additional modeling and machine learning expertise to perfect their product.

Another company wanted to improve the marketing software they use to schedule TV ads. Using a technique called integer programming, their goal was to ensure that advertisers reach their target audiences and stay within budget, while also maximizing revenue for the networks selling the ad time.

“Once we understood what the company really cared about, we had to translate that into a math problem,” said University of South Carolina graduate student Erik Palmer. “The first day was really about listening and letting the industry partner lead.”

Mathematicians Chris Breward of the University of Oxford and Sean Bohun of the University of Ontario Institute of Technology were among more than 80 people who met at Duke in June for a week-long problem-solving workshop for scientists and engineers from industry and academia.

Mathematicians Chris Breward of the University of Oxford and Sean Bohun of the University of Ontario Institute of Technology were among more than 80 people who met at Duke in June for a week-long problem solving workshop for scientists and engineers from industry and academia.

For the rest of the week, the participants broke up into teams and fanned out into classrooms scattered throughout the math and physics building, one classroom for each problem. There they worked for the next several days, armed with little more than caffeine and WiFi.

In one room, a dozen or so faculty and students sat in a circle of desks in deep concentration, intently poring over their laptops and programming in silence.

Another team paced amidst a jumble of power cords and coffee cups, peppering their industry partner with questions and furiously scribbling ideas on a whiteboard.

“Invariably we write down things that turn out later in the week to be completely wrong, because that’s the way mathematical modeling works,” said University of Oxford math professor Chris Breward, who has participated in the workshop for more than two decades. “During the rest of the week we refine the models, build on them, correct them.”

Working side by side for five days, often late into the night, was intense.

“It’s about learning to work with people in a group on math and coding, which are usually things you do by yourself,” Ciocanel said.

“By the end of the week you’re drained,” said math graduate student Ann Marie Weideman of the University of Maryland, Baltimore County.

For Weideman, one of the draws of the workshop was the fresh input of new ideas. “Everyone comes from different universities, so you get outside of your bubble,” she said.

“Here people have tons of different approaches to problems, even for things like dealing with missing data, that I never would have thought of,” Weideman added. “If I don’t know something I just turn to the person next to me and say, ‘hey, do you know how to do this?’ We’ve been able to work through problems that I never could have solved on my own in a week’s worth of time.”

Supported by funding from the National Science Foundation and the industry partners, the workshop attracts a wide range of people from math, statistics, biostatistics, data science, computer science and engineering.

monday_groupMore than 50 graduate students participated in this year’s event. For them, one of the most powerful parts of the workshop was discovering that the specialized training they received in graduate school could be applied to other areas, ranging from finance and forensics to computer animation and nanotechnology.

“It’s really cool to find out that you have some skills that are valuable to people who are not mathematicians,” Pellico said. “We have some results that will hopefully be of value to the company.”

On the last day of the workshop, someone from each group presented their results to their company partner and discussed possible future directions.

The participants rarely produce tidy solutions or solve all the problems in a week. But they often uncover new avenues that might be worth exploring, and point to new approaches to try and questions to ask.

“We got lots of new ideas,” said industry representative Marco Montes de Oca, whose company participated in the MPI workshop for the second time this year. “This allows us to look at our problems with new eyes.”

Next year’s MPI workshop will be held at the New Jersey Institute of Technology in Newark.

Robin SmithPost by Robin A. Smith

Post-Game Roundup from the Brain Teaser Bowl

Duke claims another top ten finish in North America’s most prestigious math competition

DURHAM, N.C. — The Blue Devils may have lost in the Sweet 16 during March Madness 2016, but a Duke team crushed more than 500 other schools in the NCAA tournament of the math world, known by mathletes as the Putnam, claiming a top ten finish for the 22nd time since 1990.

Left to right, Trung Can, Feng Gui, Professor David Kraines, Tony Qiao and Alex Milu are pictured in front of the Math/Physics Building. Can, Gui, Qiao and Milu are the top four Duke finishers in the annual Putnam Competition. Their combined rankings carried Duke to a tenth place finish overall. Photo by Megan Mendenhall, Duke Photography.

Left to right, Trung Can, Feng Gui, Professor David Kraines, Tony Qiao and Alex Milu are pictured in front of the Math/Physics Building. Can, Gui, Qiao and Milu are the top four Duke finishers in the annual Putnam Competition. Their combined rankings carried Duke to a tenth place finish overall. Photo by Megan Mendenhall, Duke Photography.

Alex Milu ’16, Tony Qiao ’17, Trung Can ’18 and Feng Gui ’18 scored higher than 90 percent of the 4,275 undergraduates who competed in this year’s event. More than a dozen other Duke students also competed in this year’s contest. The results of the 76th annual competition were announced this month.

Named after an 1882 Harvard graduate, the William Lowell Putnam Mathematical Competition is the most prestigious college-level math contest you have probably never heard of.

Every year on the first Saturday in December, thousands of students from across the U.S. and Canada compete in a grueling six-hour exam to see who can be the Steph Curry of math.

Contestants in the annual Putnam Competition have six hours to solve 12 problems.

Contestants in the annual Putnam Competition have six hours to solve 12 problems.

Armed with nothing more than pencil and paper, their task is to solve 12 brain bending math problems. No laptops, no course notes.

“These are not problems that textbook learning will help you much with,” said associate professor of mathematics David Kraines, who has coached Duke’s Putnam teams for much of the past 25 years.

“Knowing anything beyond calculus or linear algebra is really not a help,” Kraines said. Instead, coming up with solutions requires an “ability to think abstractly and outside the box.”

“We have A+ students who don’t do well at all in this competition, and others who don’t get great grades for one reason or another, and who become Putnam stars,” Kraines said.

“You have to think more creatively than you do in class,” said Feng Gui, who finished among the top 8 percent and competed in similar competitions as a high school student in China.

One question gave the sequence of numbers 6,16,27,36…, and asked the competitor to prove or disprove that there is some number in the sequence whose base 10 representation ends with 2015.

“Most of the questions don’t have numerical answers,” Kraines said. “They say ‘prove this,’ or ‘show that.’ To do well you have to justify your solution mathematically.”

A perfect score on the 12-question test is 120 points, but the grading is so tough that almost two thirds of this year’s Putnam contestants got zero points. Only one in five contestants correctly solved even one problem.

“It was a little tougher than usual,” said Alex Milu of Bucharest, Romania, a Karsh Scholar who took the Putnam for the fourth time this year and was named Honorable Mention for scoring in the top two percent, or 54th out of 4,275 students.

Calculators wouldn't have been much help in tackling the test questions from this year's Putnam Competition.

Calculators wouldn’t have been much help in tackling the test questions from this year’s Putnam Competition.

For Trung Can, a former gold medalist from Vietnam in the annual International Math Olympiad (IMO), the world math championship for high schoolers, math competitions like the Putnam are an opportunity to “meet people who share the same passion. Those friendships can last a lifetime,” said Can, who will help lead a training camp for high school students in Vietnam this July.

The Blue Devils competed sporadically in the Putnam in the 1970s and 80s, but Duke’s first top ten win was in 1990, when a three-person Duke team finished in second place behind Harvard.

That year, Kraines persuaded the department to start offering a half-credit problem-solving seminar in the fall to prepare students for the competition. Each week they focus on a different topic. One week it might be number theory, the next week geometry or combinatorics the week after that. “We entice them with pizza,” Kraines said.

Around the same time, Duke also started making a concerted effort to attract top math students the same way college sports recruiters attract basketball stars.

“I was able to get on the scholarship committee and we started actively recruiting,” Kraines said. “It worked. We got some fantastic kids.”

What followed was a 15-year run of near-continuous top three finishes. Since 1990, Duke Putnam teams have ranked No. 1 in North America three times, No. 2 twice, and No. 3 six times.

Duke’s Putnam champs don’t burn benches to mark major victories, but they do celebrate in other ways.

Hanging proudly in the math department lounge are some of the retired jerseys of the five Duke students who have placed among the top five highest-ranking individual finishers, known as “Putnam Fellows,” a distinction shared by several Fields Medal winners and Nobel laureates in physics.

The No. 2 jersey of 2002 Putnam winner Melanie Wood is among them, a reminder of the last time a Duke student finished among the top five individual spots.

A scrapbook in Kraines’ office contains dozens of newspaper clippings and other keepsakes from Duke’s earliest wins, including a congratulatory letter from former NC Governor Jim Hunt.

Kraines plans to retire from teaching next year after 45 years at Duke, but this won’t be his last Putnam. “It’s been a very good experience. I don’t plan to leave,” Kraines said.

 

Post by Robin A. Smith Robin Smith

 

Why Testing Lemur Color Vision is Harder Than it Looks

Elphaba the aye-aye is not an early riser. A nocturnal primate with oversized ears, bulging eyes and long, bony fingers, she looks like the bushy-tailed love child of a bat and an opossum.

She would much rather sleep in than participate in Duke alum Joe Sullivan’s early morning vision tests.

“I can’t blame her,” said Sullivan, who graduated from Duke in 2015.

Elphaba is one of 14 aye-ayes at the Duke Lemur Center in Durham, North Carolina, where researchers like Sullivan have been trying to figure out if these rare lemurs can tell certain colors apart, particularly at night when aye-ayes are most active. But as their experiments show, testing an aye-aye’s eyesight is easier said than done.

Elphaba the aye-aye takes a vision test at the Duke Lemur Center in Durham, North Carolina. She’s getting encouragement from student researcher Joe Sullivan and technician Jennifer Templeton. Photo by David Haring.

Elphaba the aye-aye takes a vision test at the Duke Lemur Center in Durham, North Carolina. She’s getting encouragement from student researcher Joe Sullivan and technician Jennifer Templeton. Photo by David Haring.

Aye-ayes don’t see colors as well as humans do. While we have genes for three types of color-sensing proteins in our eyes, aye-ayes and most other mammals have two, one tuned to blue-violet light and another that responds to green.

In all animals, the eyes’ color-detecting machinery depends on medium to bright light. In a version of “use it or lose it,” the genes responsible for color vision in some nocturnal species have decayed over time, such that they see the world in black and white.

But in aye-ayes, research shows, the genes for seeing colors remain intact, and scientists at Duke and elsewhere are trying to understand why.

One possibility is the aye-aye’s color vision genes are mere leftovers, relics passed down from daylight-loving ancestors and no longer useful to aye-ayes today.

Or, the genes may have been preserved because color vision gives aye-ayes an edge. Wild aye-ayes live by eating fruit, nuts, nectar and grubs in the rainforests of Madagascar. Wouldn’t an animal that could distinguish the blue fruits of a favorite snack like the Traveler’s palm from the green of the surrounding foliage have an advantage?

Understanding what aye-ayes can see is no easy feat. One of the most common tests for colorblindness, the Ishihara, requires the subject to recognize and identify numbers hidden within a patch of colored dots of different sizes and brightness.

Aye-ayes don’t read numbers, so Sullivan tests for color vision using food and colored cards.

The first tests were simple enough. In a dimly lit enclosure, a trainer held up two cards: a white card and a black one.

Each time the aye-ayes chose the white card over the black one by reaching out and touching it with their hand, the animal got a peanut.

Even animals with no color vision can tell white from black, so Sullivan was confident they’d ace the test. But aye-ayes aren’t programmed to please. Just getting them to sit still, instead of running around their enclosure, was a challenge.

One aye-aye, 29-year-old Ozma who was born in the wild in Madagascar, never got the hang of even the most basic task, a warmup involving a single white card.

“That’s when I realized that aye-ayes don’t always play by my rules,” said Sullivan, who started working at the Duke Lemur Center as an undergraduate research intern in 2012.

After four months and 200 trials, all five of the aye-ayes in Sullivan’s study started picking the white card more often than not, with Merlin, Elphaba and Grendel passing the test at least 70 percent of the time.

Norman and Ardrey tended to reach for the card on their left, no matter what the color.

Sullivan isn’t giving up. Still working at the Duke Lemur Center post-graduation, now he’s trying to see if aye-ayes can distinguish a purplish card from a green one, in brighter light more similar to dawn or dusk.

So far, Merlin and Grendel are getting it right just over half the time, leaving Sullivan still unsure if the aye-ayes are choosing the cards by their colors or by some other cue.

“I came in thinking that the aye-ayes were going to play nice and do everything I wanted. That was so wrong,” Sullivan said. “Still, they’ve been very good sports.”

How do you give a lemur a vision test? Photo by David Haring, Duke Lemur Center.

How do you give a lemur a vision test? Photo by David Haring, Duke Lemur Center.

Post by Robin A. Smith Robin Smith

3-D Movies of Life at Nanoscale Named Best Science Paper of the Year

If you’ve ever wanted to watch a killer T cell in action, or see human cancer make new cells up-close, now is your chance.

A collection of 3-D movies captured by Duke biology professor Dan Kiehart and colleagues has won the 2015 Newcomb Cleveland Prize for most outstanding paper in the journal Science.

The paper uses a new imaging technique called lattice light-sheet microscopy to make super high-resolution three-dimensional movies of living things ranging from single cells to developing worm and fly embryos.

https://www.youtube.com/watch?v=fwzIUnKNw0s

Cutting-edge microscopes available on many campuses today allow researchers to take one or two images a second. But the lattice light-sheet microscope, co-developed by 2014 Nobel Prize winner Eric Betzig, lets researchers take more than 50 images a second, and in the specimen’s natural state, without smooshing it under a cover slip.

You can watch slender antennae called filopodia extend from the surface of a human cancer cell, or tiny rods called microtubules, several thousand times finer than a human hair, growing and shrinking inside a slide mold.

Daniel Kiehart and former Duke postdoctoral fellow Serdar Tulu made a video of the back side of a fruit fly embryo during a crucial step in its development into a larva.

Chosen from among nominations submitted by readers of Science, the paper has been viewed more than 20,000 times since it was first published on October 24, 2014.

The award was announced on February 12, 2016, at an award ceremony held during the annual meeting of the American Association for the Advancement of Science (AAAS) in Washington, D.C.

Winners received a commemorative plaque and $25,000, to be shared among the paper’s lead authors Eric Betzig, Bi-Chang Chen, Wesley Legant and Kai Wang of Janelia Farm Research Campus.

Read more: “Lattice light-sheet microscopy: Imaging molecules to embryos at high spatiotemporal resolution,” Chen, B.-C., et al. Science, October 2014. DOI:10.1126/science.1257998

 

Post by Robin A. Smith Robin Smith

 

Charles Darwin Artifacts You Can Find at Duke

In this letter written nearly 150 years ago, Charles Darwin asks whether nest-building is something birds instinctively know how to do from birth, or whether it’s a skill they get better at with practice -- a question researchers continue to investigate today.

In this letter written nearly 150 years ago, Charles Darwin asks whether nest-building is something birds instinctively know how to do from birth, or whether it’s a skill they get better at with practice — a question researchers continue to study today.

Hidden among more than four million books and documents stacked three stories high, in a room kept a constant 50 degrees with 30 percent humidity, Duke’s Rubenstein Library houses several letters and early edition publications by one of history’s greatest scientists — the British naturalist Charles Darwin.

Born more than 200 years ago today, Darwin famously wrote thousands of letters in his lifetime. You can find several of the handwritten originals at Duke, on topics ranging from how birds moult to the behavior of blow flies.

“I begin to think that the pairing of birds must be as delicate and tedious an operation as the pairing of young gentlemen and ladies,” a 59-year-old Darwin wrote to his bird-loving friend and frequent correspondent John Jenner Weir on April 18, 1868.

Also available is an 1855 copy of Darwin’s firsthand account of the voyage of the Beagle. These and other Darwin writings are available by request at http://library.duke.edu/rubenstein/.

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Visitors to Duke’s Rubenstein Library can browse an 1855 copy of Darwin’s firsthand account of the voyage of the Beagle, “Journal of Researches into the Natural History and Geology of the Countries Visited During the Voyage of H.M.S. Beagle Round the World, Under the Command of Capt. Fitz Roy, R.N.”

Post by Robin A. Smith Robin Smith

 

 

 

Middle Schoolers Ask: What's it Like to be a Scientist?

PostdocsWhen a group of local middle schoolers asked four Duke postdocs what it’s like to be a scientist, the answers they got surprised them.

For toxicologist Laura Maurer, it means finding out if the tiny silver particles used to keep socks and running shirts from getting smelly might be harmful to your health.

For physics researcher Andres Aragoneses, it means using lasers to stop hackers and make telecommunications more secure.

And for evolutionary anthropologist Noah Snyder-Mackler, it means handling a lot of monkey poop.

The end result is a series of short video interviews filmed and edited by 5th-8th graders in Durham, North Carolina. Read more about the project and the people behind it at http://sites.duke.edu/pdocs/, or watch the videos below:

Science a waste of money? “Wastebook” misses big picture

Duke biologist Sheila Patek explains the big picture behind a recent study on sparring mantis shrimp. Photograph by Roy Caldwell.

Duke biologist Sheila Patek explains the big picture behind a recent study on sparring mantis shrimp. Photograph by Roy Caldwell.

Sheep in microgravity. An experiment involving a monkey in a hamster ball on treadmill. These are among more than 100 descriptions of what Senator Jeff Flake, Republican of Arizona, deems wasteful federal spending in “Wastebook: The Farce Awakens,” released on Tuesday, Dec. 8. The latest in a series originally launched by retired Senator Tom Coburn, each “Wastebook” targets a range of federally-funded projects, many of them science-related, which the authors declare a waste of taxpayers’ money.

But what do the researchers behind these projects have to say? We asked Duke biologist Sheila Patek, whose work on fighting mantis shrimp was singled out in Flake’s latest report, to tell us her side of the story:

“What do we stand to learn from basic research on mantis shrimp? It turns out, a lot,” Patek said.

“First, mantis shrimp strike with weapons operating at the same acceleration as a bullet in the muzzle of a gun, yet they achieve high performance without explosive materials. They use a system based on muscles, springs and latches and neutralize their opponents with impact-resistant armor. This research helps us understand how animals survive when they have lethal weapons at their disposal but do not actually kill the opponent — something that could change the way we look at future defense systems,” Patek said.

“Second, these crustaceans have properties of extreme acceleration that are of great interest to military and manufacturing engineers. Mantis shrimp use a toothpick-sized hammer that can break snail shells in water that humans can only break with a larger hammer in air. Their small, lightweight hammer resists fracture over thousands of uses. Our research has already led to the development of novel engineered materials that resist impact fracture, based directly on mantis shrimp hammers,” Patek said.

“Third, mantis shrimp do something else that humans cannot: strike in water at the speed of cars on a major highway without causing cavitation, a phenomenon that occurs in systems with rapid motion (like propellers) where implosive bubbles emit heat, light and sound with energy sufficient to wear away steel. Naval engineers have been trying to solve this problem since the invention of the submarine. When we understand how mantis shrimp avoid cavitation during the rotation phase of their strikes while effectively using cavitation during their impact phase, the knowledge will undoubtedly improve the capabilities of ships, submarines, torpedoes and other machines,” Patek said.

“Research that helps us understand and apply the mechanics and evolutionary diversity of natural systems to create a better and safer society for all of us is a wise investment for this country.”

RobinSmith_hed100Post by Robin A. Smith, Senior Science Writer

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