Aging Gracefully, and Cheaply, in a Small Space

The old joke is, “We’ve cured cancer several times — in mice!”

But the trouble with our favorite lab animal is that they aren’t nearly as close to humans as we had hoped.

Researchers who are working on human longevity obviously need a model organism — they can’t keep their funding going for 100 years to see how a person dies. And other primates aren’t ideal, either; they’re also pretty long-lived and expensive to house, besides.

microcebus mouse lemurs

Mouse lemurs at a lab outside Paris eagerly lap up their calories. Sometimes it’s great being in the control group. (CNRS photo)

So what if you had a primate that was relatively short-lived, say 13 years tops, and quite small, say 100 grams, a bit bigger than a mouse? Behold the Mouse Lemur, Microcebus, the smallest member of the primate family.

In a pair of presentations Friday during the Duke Lemur Center’s 50th Anniversary scientific symposium, gerontologists Fabien Pifferi of the French national lab CNRS, and Steven Austad, chair of biology at the University of Alabama-Birmingham (UAB), made their arguments for how well “le microcèbe” might work in studying aging in humans.

Pifferi works at one of two mouse lemur breeding colonies in France, which is housed in an elegant old chateau in Brunoy, a suburb southeast of Paris. There, a 450-member breeding colony of grey mouse lemurs produces about 100 pups a year, and the scientists have devised many clever, non-invasive ways to test their physical and mental abilities as they age.

“It seems like their normal aging is very similar to humans,” Pifferi said. But about 20 percent of the tiny lemurs follow a different trajectory, marked by the formation of brain plaques, atrophy of the brain and cognitive declines. It’s not exactly Alzheimer’s disease, he said, but it may be a useful scientific model of human aging.

Aging, UAB’s Austad began, is already the number one health challenge on the planet and will remain so for the foreseeable future. We need a good research model to understand not just how to achieve longevity, but how to live healthy longer, he said.

Filbert, a grey mouse lemur, was born at the Duke Lemur Center in June 2013, weighing less than two cubes of sugar. He should still be around in 2023 at least.

Filbert, a grey mouse lemur, was born at the Duke Lemur Center in June 2013, weighing less than two cubes of sugar.

Citing some early studies on using calorie restriction and rapamycin to increase longevity, Austad said mouse lemurs may be “a mid-way model between mice and humans.”

The CNRS colony at Brunoy tried to replicate a study on calorie restriction and longevity that yielded mixed results in other animals. The mouse lemurs in the experimental condition thrived.

“I saw this colony last year,” Lemur Center Director Anne Yoder said. “The one remaining control animal was old and feeble and sort of pathetic. The four calorie-restricted animals were bouncing around, they were glossy.” Though suffering age-related blindness at that point, they were very much alive and frisky, Pifferi added.

“I think the mouse lemur is a great intermediate to do these sorts of studies,”  Austad said.

But, as you may imagine, some members of the lemur community who had dedicated their lives to preserving rare and critically endangered lemurs might struggle with the idea of  breeding up mouse lemurs to use as lab animals, even if the tests are non-invasive. Nobody asked hostile questions, but the discussion is sure to continue.

Karl Leif BatesPost by Karl Leif Bates

How to Get a Lemur to Notice You

Duke evolutionary anthropology professor Brian Hare studies what goes on in the minds of animals.

Duke evolutionary anthropology professor Brian Hare studies what goes on in the minds of animals.

Duke professor Brian Hare remembers his first flopped experiment. While an undergraduate at Emory in the late 1990s, he spent a week at the Duke Lemur Center waving bananas at lemurs. He was trying to see if they, like other primates, possess an important social skill. If a lemur spots a piece of food, or a predator, can other lemurs follow his gaze to spot it too?

First he needed the lemurs to notice him. If he could get one lemur to look at him, he could figure out if other lemurs then turn around and look too. In similar experiments with monkeys and chimps, oranges had done the trick.

“But I couldn’t get their attention,” Hare said. “It failed miserably.”

Hare was among more than 200 people from 25 states and multiple countries who converged in Durham this week for the 50th anniversary celebration of the Duke Lemur Center, Sept. 21-23, 2016.

Humans look to subtle movements in faces and eyes for clues to what others are thinking, Hare told a crowd assembled at a two-day research symposium held in conjunction with the event.

If someone quickly glances down at your name tag, for example, you can guess just from that eye movement that they can’t recall your name.

We develop this skill as infants. Most kids start to follow the gaze of others by the age of two. A lack of interest in gaze-following is considered an early sign of autism.

Arizona State University graduate student Joel Bray got hooked on lemurs while working as an undergraduate research assistant in the Hare lab.

Arizona State University graduate student Joel Bray got hooked on lemurs while working as an undergraduate research assistant in the Hare lab.

“Gaze-following suggests that kids are starting to think about the thoughts of others,” Hare said. “And using where others look to try to understand what they want or what they know.”

In 1998 Hare and researchers Michael Tomasello and Josep Call published a study showing that chimpanzees and multiple species of monkeys are able to look where others are looking. But at the time not much was known about cognition in lemurs.

“When you study dogs you just say, ‘sit, stay,’ and they’re happy to play along,” Hare said. Working at the Duke Lemur Center, eventually his students discovered the secret to making these tree-dwelling animals feel at home: “Lemurs like to be off the ground,” Hare said. “We figured out that if we just let them solve problems on tables, they’re happy to participate.”

Studies have since shown that multiple lemur species are able to follow the gaze of other lemurs. “Lemurs have gone from ignored to adored in cognitive research,” Hare said.

 

Ring-tailed lemurs are among several species of lemurs known to follow the gaze of other lemurs. The ability to look where others are looking is considered a key step towards understanding what others see, know, or might do. Photo by David Haring, Duke Lemur Center.

Ring-tailed lemurs are among several lemur species known to follow the gaze of other lemurs. The ability to look where others are looking is considered a key step towards understanding what others see, know, or might do. Photo by David Haring, Duke Lemur Center.

Robin SmithPost by Robin A. Smith

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

“Gastronauts” Decode Gut-Brain Communication

We like to think of our brains as the ultimate commanders-in-chief, dictating each and every heartbeat and muscle twitch within our bodies.

But our loopy insides may have a lot more say than we realize.

normal_gastric_mucosa_low_mag

Healthy mucosal cells in the human stomach, magnified. (credit: Nephron)

“Not only does the brain send information to the gut, but the gut sends information to the brain,” said Michael Gershon, professor of pathology and cell biology at Columbia University. “And much of that we don’t yet understand.”

Gershon was one of nearly 200 scientists gathered at Duke last Friday for Gastronauts, a symposium exploring how our twisty, slimy guts and our twisty, slimy brains communicate with each other. By decoding the cellular and molecular messaging behind this gut-brain chatter, these researchers hope to gain insight into a wide array of modern health challenges, from obesity to Alzheimer’s.

Scientists gathered in the Trent Semans Great Hall for the Gastronauts poster session

Nearly 200 scientists gathered in the Trent Semans Great Hall Sept. 9 for Gastronauts, sponsored by the Duke Institute for Brain Sciences.

Even if you sever all nerve connections between the brain and the gut, Gershon explained, your digestive tract will still carry on all that squeezing and acid-secreting necessary to digest food. The gut’s ability to ‘direct its own traffic’ led Gershon to dub the gut’s nervous system our “Second Brain.”

“The brain in the head deals with the finer things in life like religion, poetry, politics, while the brain in the gut deals with the messy, dirty, disgusting business of digestion,” Gershon said.

Our head brain and our gut brain talk to each other via long nerve fibers, such as a bundle of nerve cells called the vagus nerve that links the central nervous system to our abdominal organs, or via chemical signals, such as the neurotransmitter serotonin. Talks throughout the day delved into different aspects of these interactions – from how eating sugar can change our perception of taste to how the make-up of our gut microbiome might influence neural connectivity in the brain.

An illustration of human viscera

Our twisty loopy intestines can operate independently of our brains.

Duke professor Warren Grill presented his latest research on electrical stimulation of the vagus nerve. In projects led by graduate student Nikki Pelot and senior Eric Musselman, his group is building computer models to simulate the effects of electrical pulses on individual nerve cells within the vagus. These models might allow researchers to design devices to specifically block electrical signals going to the gut, a treatment that has been shown to help with obesity, Grill said.

And though we may think of the gut as the second brain, we should all remember that it came first, Duke professor Diego Bohórquez reminded the audience in the opening remarks.

“I like to say the gut is actually the first brain,” said Bohórquez. “If you go back to seafloor organisms, that was the first nervous system that was assembled.”

 

 

 

Kara J. Manke, PhD


Post by Kara Manke

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

LHC Reveals No New Physics Yet, but Duke Scientists Stay the Hunt

For particle physicists, “expect the unexpected” is more than just a catchy tagline.

Duke scientists on the Large Hadron Collider’s (LHC’s) ATLAS collaboration are on the hunt for hints of the unexpected: new, undiscovered particles or forces that could point to theories beyond the remarkably accurate, yet clearly incomplete, Standard Model of physics.

IMG_0721_crop

The Duke physics team at CERN this summer, gathered in front of a model of one of the LHC’s superconducting electromagnets. (Left to right: Ifeanyi Achu, Emily Stump, Elisa Zhang, Hannah Glaser, Wei Tang, Spencer Griswold, Andrea Bocci, Minyu Feng, Shu Li and Al Goshaw).

But the tsunami of new data coming out of the LHC’s current run, which began May of this year, has yet to provide any promising clues. Notably, at the ICHEP conference in Chicago, ATLAS collaboration members presented new results showing that an intriguing “bump” observed in 2015 data — speculated to be the first evidence of a completely new particle six times the mass of the Higgs — was likely just a statistical fluctuation in the data.

“It was quite amazing,” said Duke physics professor Al Goshaw, a member of the ATLAS collaboration. “With this new data there should have been a very clear signal, and there is nothing. It’s just absolutely gone.”

Goshaw has spent much of the summer at CERN, leading a team of undergraduate and graduate scientists crunching the numbers on the new data. Undeterred by the results presented in Chicago, he says the Duke team is still hard at work searching for other massive new particles.

“Our plan is to take the full data set collected in 2016 and extend the search for a new force-carrying particle up to much higher energies,” Goshaw said. “The search will go up to about 25 times the mass of the top quark or 35 times the mass of the Higgs.” They aim to have the results of this analysis ready by early 2017.

Why all the interest in tracking down these massive new particles?

ATLAS-CONF

Particle and energy spray recorded following a high-energy proton-proton collision event at the LHC in May. (Credit: CERN)

Goshaw says there are a myriad of alternative theories to the standard model, so many that trying to test specific predictions of individual models would be prohibitively time-consuming.

“But there is one prediction which they almost all make, and that is that there should be additional massive particles beyond those contained in the standard model,” Goshaw said. “So a generic way to search is to look for the new forces which are indicated by a force carrier, a massive new particle.”

The new data, collected at higher energies than the 2010-2012 run and with higher “brightness” or luminosity than the 2015 run, gives physicists the best chance yet of spotting an elusive new particle.

However, it’s not always looking at a plot and looking for a little bump, Goshaw says. Physicists, including the Duke team, are also utilizing the new data to perform highly precise tests of the standard model.

“The precision tests are really trying to find cracks in the standard model,” Goshaw said. “There could be particles that are so massive that we cannot detect them, but they may appear as subtle deviations in standard model predictions.”

But for now, the tried-and-true still holds. “It is quite extraordinary that, with these beautiful tests, everything is still described by the standard model,” Goshaw said.

Kara J. Manke, PhD

Post by Kara Manke

Beauty is in the Ear of the Beholder Too

Just the suggestion that an African-American person is of mixed-race heritage makes that person more attractive to others, research from Duke University concludes.

Reece_imageThis holds true even if the people in question aren’t actually of multiracial heritage, according to the peer-reviewed study, published in the June 2016 issue of Review of Black Political Economy.

The simple perception of exoticism sways people to see multiracial blacks as better-looking, says study author Robert L. Reece, a doctoral candidate in sociology at Duke.

“Being exotic is a compelling idea,” Reece says. “So people are attracted to a certain type of difference. It’s also partially just racism – the notion that black people are less attractive, so being partially not-black makes you more attractive.”

Reece used data from the National Longitudinal Study of Adolescent Health. He examined the results of in-person interviews of 3,200 black people conducted by people of varying races. The interviewees were asked a series of questions that included their racial backgrounds. The questioners then ranked each person’s attractiveness on a scale of 1 to 5, with 1 being the least attractive and 5 being the most attractive. The interviewees who identified as mixed race were given an average attractiveness rating of 3.74; those who identified as black were given a 3.47 score – a statistically significant difference that points to the power of perception, Reece says. (The study controlled for a number of factors such as gender, age, skin tone, hair color and eye color)

“Race is more than we think it is,” he says. “It’s more than physical characteristics and ancestry and social class. The idea that you’re a certain race shapes how people view you.”

And attractiveness matters. Previous research has drawn correlations between physical beauty and professional success.

Robert Reece is a doctoral candidate in sociology at Duke.

Robert Reece is a doctoral candidate in sociology at Duke.

Reece’s findings bolster a viewpoint that lighter-skinned blacks are considered more physically striking than their darker-skinned counterparts. But his research also found that blacks with darker skin who identified as mixed-race were considered better looking than those with lighter skin who identified simply as black. This further emphasizes the power of suggestion, Reece says; being told a person is of mixed race – regardless of what that person looks like – makes them appear more attractive.

“It’s a loaded cognitive suggestion when you say ‘I’m not just black, I’m also Native American, for example,” Reece says. “It changes the entire dynamic.”

Reece tackled this topic to examine the connection between multiraciality and “color,” he says.

“People tend to assume that historical multiraciality is at least partially responsible for the broad range of color among black people,” he says. “I’ve even noticed some people in black communities casually using the terms “mixed” and “light skinned” interchangeably. So I wanted to begin an empirical investigation into the contemporary links between the two and how they combine to shape people’s life experiences. Attractiveness is one part of that.”

Ferreri_100Guest post by Eric Ferreri

Taking Math Beyond the Blackboard

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

Fledgling Physicists Embark for the LHC

For physics student Hannah Glaser, taking off for a summer of hands-on research at the world’s largest particle collider is both exciting and terrifying.

But, Glaser says, joining the thousands of scientist at work at the Large Hadron Collider (LHC) also feels a lot like going home.

“It’s such a huge relief to finally be in a group of people who who are interested in the same exact kind of problems that you are,” said Glaser, a rising junior at Virginia Tech. “It really is just this ridiculous nerdy feeling when you finally meet a group of people who have the same obsession with math and science.”

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Undergraduate physicists embarking for a summer at the LHC, posed in front of a map of CERN and neighboring town St. Genis hand-drawn by physics professor Al Goshaw. From left: Wei Tang (Duke), Ifeanyi Achu (Southern Methodist University), Spencer Griswold (Clarkson University), Elisa Zhang (Duke), Emily Stump (Williams College) and Hannah Glaser (Virginia Tech).

Glaser is among six undergraduates — two from Duke and four from other institutions — who will be working alongside Duke scientists at the LHC’s ATLAS experiment this summer. Each will tackle a bite-sized piece of the immense particle physics project, primarily by helping to analyze the massive amounts of data generated by the collider.

“Just going to CERN will be a mind-blowing experience,” said Ifeanyi Achu, a junior at Southern Methodist University, at an orientation event at Duke last week. “I’m looking forward to getting a window into what life could be like as a physics researcher.”

Before setting off for CERN, the group spent the month of June with other REU students on Duke’s campus, learning the basics of quantum mechanics and Root, a software platform used CERN and other particle accelerators around the world.

In addition to grappling with complex physics, the students also had to prepare for the more practical aspects of spending six weeks abroad – like the fact that they will be living in the French town of St. Genis while working in Switzerland, requiring that they regularly cross the border and navigate among two or more currencies and languages.

However, the thrill of spending time with some of the world’s biggest experiments should make the travel anxiety worth it.

ATLAS

Duke student Wei Tang hopes to get a picture with a giant LHC detector while working at CERN this summer. (Credit: CERN)

“I’m definitely looking forward to taking a picture with a giant detector,” said Wei Tang, a Duke junior majoring in physics and computer science.

As members of the ATLAS experiment, The Duke high-energy physics team hopes to spot particles or forces not predicted by the Standard Model of physics, the theoretical framework that currently forms the basis of our physical understanding of the universe. New particles or forces could provide clues to solving some of the mysteries that remain in physics, such as what is the nature of dark matter.

“This is probably the most exciting year for the LHC,” said Duke physicist Al Goshaw, who will be onsite advising the students for part of the summer. “Data taken in this run really offers an extraordinary opportunity to look for physics beyond the standard model because it is the first time the LHC is operating at its full potential. It really could be the discovery run, and we are excited to be involved in that.”

But even if new discoveries aren’t made this summer, the students are still thrilled to be a part of the experiment.

“To know that you have done just a tiny bit of science at CERN – it’s just a dream come true for anyone interested in particle physics,” Glaser said.

Kara J. Manke, PhD

Post by Kara Manke

Cracking a Hit-and-Run Whodunit — With Lasers

The scratch was deep, two feet long, and spattered with paint flecks. Another vehicle had clearly grazed the side of Duke graduate student Jin Yu’s silver Honda Accord.

But the culprit had left no note, no phone number, and no insurance information.

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Duke graduate student Jin Yu used laser-based imaging to confirm the source of a large scratch on the side of her car. Paint samples from an undamaged area on her Honda Accord (top left) and a suspected vehicle (top right) gave her the unique pump-probe microscopy signatures of the pigments on each car. The damaged areas of the Honda (bottom left) and the suspected vehicle on right (bottom right) show pigment signatures from both vehicles.

The timing of the accident, the location of the scratch, and the color of the foreign paint all pointed to a likely suspect: another vehicle in her apartment complex parking lot, also sporting a fresh gash.

She had a solid lead, but Yu wasn’t quite satisfied. The chemistry student wanted to make sure her case was rock-solid.

“I wanted to show them some scientific evidence,” Yu said.

And lucky for her, she had just the tools to do that.

As a researcher in the Warren Warren lab, Yu spends her days as scientific sleuth, investigating how a laser-based tool called pump-probe microscopy can be used to differentiate between individual pigments of paint, even if they appear identical to the human eye.

The team is developing the technique as a way for art historians and conservators peer under the surface of priceless paintings, without causing damage to the artwork. But Yu thought there was no reason the technique couldn’t be used for forensics, too.

“The idea popped into my mind — car paint is made up of pigments, just like paintings,” Yu said. “So, if I can compare the pigments remaining on my car with the suspected car, and they match up, that would be a pretty nice clue for finding the suspected car.”

Using a clean set of eyebrow tweezers, Yu carefully gathered small flecks of paint from her car and from the suspected vehicle and sealed them up inside individual Ziploc bags. She collected samples both from the scratched up areas, where the paint was mixed, and from undamaged areas on both cars.

She left a note on the car, citing the preliminary evidence and stating her plan to test the paint samples. Then, back at the lab, she examined all four samples with the pump-probe microscope. Unlike a standard optical microscope, this device illuminates each sample with a precisely timed series of laser pulses; each pigment absorbs and then re-emits this laser light in a slightly different pattern depending on its chemical structure, creating a unique signature.

Optical-Microscope-and-Note

After finding the gash on her Accord (top left), Yu left a note (top right) on the car that she suspected of having caused the accident. Under an optical microscope, samples from damaged areas on the cars show evidence of the same two kinds of paint (bottom). Yu used pump-probe microscopy to confirm that the pigments in the paint samples matched.

The samples from the undamaged areas gave her the characteristic pigment signatures from both of the two vehicles.

She then looked at the paint samples taken from the scratched areas. She found clear evidence of paint pigment from the suspected car on her Honda, and clear evidence of paint pigment from her Honda on the suspected car. This was like DNA evidence, of the automotive variety.

Fortunately, the owner of the suspect vehicle contacted Yu to confess and pay to have her car fixed, without demanding the results of the paint analysis. “But it was reassuring to have some scientific evidence in case she denied the accident,” Yu said.

Yu says she had no interest in forensic science when she started the investigation, but the experience has certainly piqued her curiosity.

“I had never imagined that I can use pump-probe microscopy for forensic science before this car accident happened,” Yu said. “But I think it shows some interesting possibilities.”

Kara J. Manke, PhD

Post by Kara Manke

LHC Reboot Promises Piles of New Data for Duke Physicists

Undeterred by a recent weasel incursion, CERN announced last week that the Large Hadron Collider (LHC) is back up and running for the 2016 season, smashing protons together at nearly the speed of light and creating exotic forms of matter in the debris.

Back at Duke, students and professors collaborating on LHC’s ATLAS experiment are eager to see if the 2016 run provides any hint of surprising new physics.

“It’s a really exciting time,” said Duke graduate student Douglas Davis. “Hopefully something comes out of this new data that we aren’t expecting.”

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CERN’s Large Hadron Collider (LHC) creates exotic forms of matter by smashing together protons that are traveling at nearly the speed of light. This image depicts a collision detected by the LHC’s ATLAS Experiment, which Duke physicists collaborate on, during beam commissioning in April. (Credit: CERN)

Since the early 1970s, physicists have relied on the Standard Model of physics to explain all the most basic bits of matter in the universe and the forces through which they interact. And it has performed remarkably well at describing all of the curious new particles the LHC has created, from the magnificent Higgs Boson to that quirky pentaquark spotted last year.

But the Standard Model can’t quite explain everything. For instance, it cannot reconcile gravity – the force whose existence we verify every time we knock over a coffee mug or drop a pen – or dark matter, which physicists know exists from observations of twisted galaxies in the cosmos.

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One of the early proton-proton collisions with recorded by ATLAS on 23 April 2016. The picture shows the very inner core of the ATLAS detector where the two beams of proton bunches from the LHC collide . In this event the colliding protons give birth to ten primary interactions, shown in white. The reconstructed tracks of the particles produced in those interactions are drawn in yellow. (Credit: CERN)

During the upcoming run, the Large Hadron Collider will be operating at its full design capacity, smashing proton bunches at energies of  13 TeV (trillion electron-volts), which is almost twice the collision energy it was capable of during the 2009 to 2013 “Run 1” that discovered the Higgs.

For the 2016 re-boot, they have also increased the “luminosity” of the beams, narrowing the size of the proton bunches to boost the number of collisions per pass by five or six times – resulting in five to six times more data.

To a particle physicist, more energy and more data means a better chance of finding anomalies in the Standard Model that could lend credence to alternate theories, like supersymmetry or string theory, or point in an entirely new direction all together.

“Anything that is even a hint of something new or non-expected these days gets everyone abuzz.” said Davis. “Everyone is waiting on pins and needles for something to happen.”

Most of the excitement in the physics world is currently over a “bump” at 750 GeV observed during the 2015 run. If confirmed, this signal could mean the discovery of a completely new particle that is six times heavier than the Higgs. But, it could also just be a statistical fluctuation.

“There is a huge amount of excitement now because soon after start-up in a few months, we should be able to determine whether that bump is real or not,” said physics Professor Mark Kruse, who leads Duke’s ATLAS team. “I’m right on the fence for whether it could be real or not real, but would probably bet that it’s not. It certainly doesn’t belong to the standard model, but unfortunately it also doesn’t fit very nicely into any of the favored contenders to replace the standard model.”

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A view of the proton collision debris field looking down the beam line (left) and from the side of the beam line (bottom right). On the top right, a zoomed-in view of the proton interaction region, showing the locations where they collide (white squares) and the reconstructed tracks. (Credit: CERN)

The Duke team won’t be focusing all its energy there. Kruse says they have researchers working on a wide variety of projects, from searching for new dark matter candidates to closely analyzing rare Standard Model events.

Davis plans to employ an analysis technique called AIDA, originally developed by Kruse, his advisor, and Kruse’s first graduate student, Sebastian Carron. Davis will use the technique to search for anomalies in a rare Standard Model process that produces two top quarks along with a Z or W boson.

And even if everything works out just as the Standard Model predicts, Davis still thinks the fact that we can collect this data at all is still pretty impressive.

“It may seem kind of boring to see everything work exactly as the Standard Model says it should, but at the same time it’s like – man, this was written down in the seventies and they probably would never have dreamed of being able to observe all this,” said Davis. “But so far, it works perfectly.”

Kara J. Manke, PhD

Post by Kara Manke