Author: Karl Bates Page 6 of 18

Director of Research Communications, Duke University

An Unconventional Career Map

On December 27, 2015

In Climate/Global Change, Computers/Technology, Environment/Sustainability, Field Research, Guest Post

Landscape ecologist Jennifer Swenson has a very special set of skills that come from having an “unconventional academic trajectory.”

Jennifer Swenson is an associate professor of the practice in geospatial analysis at the Nicholas School of the Environment

Her diverse and interesting career began at UC Santa Barbara, where she chose to learn about International Relations and Geography. “I wanted to be versatile and globally aware,” she said. Undergraduate school is where she learned the geography techniques she now uses in her research, and received stacks of reading for international relations.

After this, Swenson spent three years giving bicycle tours, working at a ski resort, and other jobs, until she went on a conservation trip to Ecuador to work for an NGO (non-governmental organization). She was able to use her geospatial techniques (GIS) to map trails and land cover change in Ecuadorian national parks, and also to evaluate forest corridors for an endangered species of monkey.

Connectivity between habitat remnants for critically endangered primate, Callicebus oenanthe, in San Martin, Peru. Presented at the 2nd Simposio de Primatologia en el Peru (Iquitos, November 2013) & at the Remote Sensing forConservation Symposium (London, May 2014) Schaffer-Smith, Swenson, Bóveda-Penalba, Murrieta-Villalobos

She learned many things, including how to manage a lab, and also became fluent in Spanish thanks to the total immersion. “It’s just another barrier,” she says, to have to use English. Plus, it is useful for reading papers that haven’t been translated.

“Everyone should learn a second or third language and have the opportunity to be immersed in that country.”

After this she went back to graduate school and got a Ph.D. in forest science at Oregon State.

Swenson’s research at Duke is often about conservation or biodiversity, and occasionally ecosystem studies. She is still using her special skills to try to do the greatest good.

“Its great to work towards that, but sometimes its hard to detect that you are doing change,” she says. “I still keep trying to forge ahead and do whatever I can for the environment. In the end, all those students that we train and send out will do great things, and that’s how we have the greatest impact for the environment.”

Guest Post by Caleb Caton, a senior at the North Carolina School of Science and Math

Checking in on Air Pollution — With an Expert!

By Karl Bates

On December 23, 2015

In Climate/Global Change, Global Health, Guest Post, Medicine

I had the pleasure of meeting and interviewing Duke Professor Junfeng “Jim” Zhang, an avid environmental health researcher who has done amazing work on air pollution research. Because of my own interest in air pollution and its adverse health effects, I began by trying to grasp Dr. Zhang’s work through his detailed scientific explanations of his projects, such as looking at the human health effects of nano-technology.

Junfeng (Jim) Zhang is a professor of global and environmental health in the Nicholas School and the Duke Global Health Institute

From my reading on the projects I was interested in, I did not expect Zhang to be able to step back and capture the importance of his research in simple terms because his projects were quite complicated (such as testing human health effects due to chemically altered diesel fuel). However, it turned out that Zhang is well-versed in communicating both crucial details of his research and the overall meaning for human health.

The most captivating aspect of my interview with Zhang was our discussion of his contribution to the 2007 Nobel Peace Prize, which was awarded to the Intergovernmental Panel on Climate Change. Dr. Zhang essentially concluded that burning and replanting trees is not necessarily carbon-neutral, disproving the common view that replanting burned trees is always carbon-neutral. His arguments really sold the importance of his research to me and I very quickly agreed with his views on the consequences of his research.

My interview with Zhang also revealed just how important scientific research is in adding evidence and findings to support a side on the growing global issues of environmental pollution and protection. It really amazed me how researchers play such a crucial supportive role in not only protecting the world’s environment, but advancing the quality of human life.

UPDATE – Professor Zhang spoke with BBC about air pollution in China. Read the story here.

Guest Post by Peter Cheng, a senior at the North Carolina School of Science and Math.

Improving Machine Learning With an Old Approach

By Karl Bates

On December 21, 2015

In Computers/Technology, Guest Post, Mathematics

Computer scientist Rong Ge has an interesting approach to machine learning. While most machine learning specialists will build an algorithm which molds to a specific dataset, Ge builds an algorithm which he can guarantee will perform well across many datasets.

Rong Ge is an assistant professor of computer science.

A paper he wrote as a postdoc at Microsoft Research, Escaping From Saddle Points — Online Stochastic Gradient for Tensor Decomposition , describes how a programmer can use the imprecision of a common machine learning algorithm, known as stochastic gradient descent, to his advantage.

Normally this algorithm is used to speed up a slow learning process by only approximating the correct solution rather than working harder to get precision; however, Ge and his colleagues found that the small amount of “noise” created by the algorithm can be the saving grace of an algorithm which would otherwise be trapped by its own perfectionism.

“This algorithm is not normally used for this purpose,” Ge says, “It is normally used as a heuristic to approximate the solution to a problem.”

Noise allows the algorithm to escape from something called a “saddle point” on the function which the stochastic gradient is trying to optimize, which looks sort of like a sine wave. Ge describes gradient descent as being like a ball rolling down a hill. When on the slope of the hill it always seeks the lowest point, but if it is at a saddle point, a high point on a “ridge” between two different slopes, it will not start rolling.

Stochastic gradient descent remedies this problem by jostling the ball enough to start it rolling down one of the slopes. But one cannot be sure which way it will roll.

The results he has obtained relate to a certain branch of machine learning known as unsupervised learning. One common problem from unsupervised learning is “clustering,” in which the algorithm attempts to find clusters of points which are similar to each other while different from the other points in the set. The algorithm then labels each of the clusters which it has found, and returns its solution to the programmer.

A key requirement for the final result of the algorithm to be correct is that the two slopes end at low points of equal depth, which represent optimal solutions. Often two solutions will appear different at first glance, but will actually represent the same set of clusters, different only because the labels on clusters were switched. Ge said one of the hardest parts of his process was designing functions that have this property.

These results are guaranteed to hold so long as the dataset is not provided by someone who has specifically engineered it to break the algorithm. If someone has designed such a dataset the problem becomes “NP hard,” meaning that there is little hope for even the best algorithms to solve it.

Hopefully we will see more growth in this field, especially interesting results such as this which find that the weaknesses associated with a certain algorithm can actually be strengths under different circumstances.

GraysonYork

Guest post by Grayson York, a junior at the North Carolina School of Science and Math

Federal Budget Raises NIH, Other R & D

By Karl Bates

On December 17, 2015

In Data, Faculty, Statistics

Reversing more than a decade of flat growth in research funding, the federal budget proposal announced Wednesday includes a $2 billion increase for the National Institutes of Health, the major source of Duke’s federal research funding. The increase would bring NIH’s budget to $32.1 billion.

Budget trends by agency. Graph courtesy of AAAS.

The budget must pass both houses of Congress and be signed by the president to take effect, but the figures being announced are the result of negotiations between House and Senate budget committees.

According to Chris Simmons, Duke’s associate vice president for government relations, other research funds Duke relies on are also slated to increase.

The National Science Foundation’s budget would increase to $7.46 billion, up $119.3 million over 2015.

The Department of Energy’s Office of Science would grow 5.6 percent to $5.35 billion.

NASA science programs would increase 6.6 percent to $5.6 billion.

Simmons added that most of the major research accounts at the Department of Defense (Basic, Applied and Advanced Technology Development) will receive increased funding. “Unfortunately Air Force Research and DARPA will see a cut in their funding by $20 and $25 million, respectively.”

“This expansion of R&D funding is very encouraging news,” said Duke Vice Provost for Research Larry Carin. “Federal investments in university research have long been a powerful engine of the American economy and we’re heartened to see policymakers returning to that commitment.”

Long-term trends by R&D purpose. Note the little spike for the economic stimulus package. Graph courtesy of AAAS.

Within the increased NIH funding, the budget includes $200 million for the Precision Medicine Initiative, a $350 million increase for Alzheimer’s disease research and an $85 million increase for the BRAIN Initiative.

“Duke has strong research positions in all three of these areas, so we’re pleased by those particular expansions,” Carin said. “Now, of course, our faculty will have to get out there and write the grants that bring that money to North Carolina.”

Post by Karl Leif Bates

Five Duke Papers Crack the Altmetric 100

By Karl Bates

On December 14, 2015

In Animals, Behavior/Psychology, Biology, Medicine

The numbers are in, and five papers with Duke authors cracked the Top 100 Altmetric scores for 2015.

Example of an Altmetric analysis.

Yeah, it all seems a little gimmicky and meta, but the scores can be useful. Altmetric (to which Duke has an institutional membership) combines multiple counts of news stories, social media chatter and professional citations on an academic paper to give it a single score. Obviously, the system’s greatest strength is comparing this to other Altmetric scores, but it’s actually a lot of fun.

Duke’s biggest score – a very impressive Altmetric 2294 – came in at #5 on the list. “Estimating the reproducibility of psychological science” attracted a lot of attention in Science, spawning 74 news stories and nearly 2,000 tweets. Postdoctoral researcher Nina Strohminger of the Kenan Institute for Ethics is one of the authors from 125 institutions on the paper that suggests psychology has some housekeeping to do.

At number 28 with an Altmetric of 1,279, came “Global, regional and national incidence, prevalence, and years lived with disability for 301 acute and chronic diseases and injuries in 188 countries, 1990-2013 (here comes the colon!): a systematic analysis for the Global Burden of Disease Study 2013.” This Lancet paper, backed by the Bill and Melinda Gates Foundation, is every bit as massive and important as its title. Among its thousands of authors is our own Terrie Moffitt. It garnered 39 news stories and 1400 tweets and has already been incorporated into nine Wikipedia entries.

A companion paper with another big title for another big study, “Global, regional, and national age-sex specific all-cause and cause-specific mortality for 240 causes of death, 1990-2013: a systematic analysis for the Global Burden of Disease Study 2013,” came in at #36 on the list with an Altmetric of 1180. Its authors might be jealous of #28, but it’s mostly the same folks! Eighty people saw fit to post this one on Facebook and 60 on Google+.

Two papers out of the now-defunct NSF think-tank the National Evolutionary Synthesis Center (NESCent) rounded out our top 100 at #72 and #87.

What are the largest ocean giants?

Craig McClain of NESCent and Duke Biology led “Sizing Ocean Giants,” an analysis that tries to get the right dimensions on a bunch of intimidating ocean creatures including the giant clam and the colossal squid (which turns out to be only a third the size of the less impressively named giant squid). The paper’s Altmetric of 954 was led by 24 news stories, 24 blog posts and almost 900 tweets. McClain also leads a very popular marine science blog “Deep Sea News” which probably aided the story’s social presence.

Number 87 was “Synthesis of phylogeny and taxonomy into a comprehensive tree of life,” which included Karen Cranston of NESCent and Duke Biology. This hugely ambitious effort to draw a tree of life for the whole planet at once earned an Altmetric of 895 by garnering 21 news stories, 12 blogs and nearly 900 tweets. And it too has been incorporated into Wikimedia – once so far.

It’s a brave new world out there in academic publishing.

Post by Karl Leif Bates

Seeing the Research for the Trees

By Karl Bates

On December 9, 2015

In Biology, Climate/Global Change, Environment/Sustainability, Field Research, Students

The Duke Forest is more than just a place to run the trails or harvest timber. It’s also an important living laboratory for Duke’s research community.

On Dec. 4, we joined the annual tour of research sites in the 7,000-acre forest, led by forest Director Sara Childs and Operations Manager Jenna Schreiber. Nearly two dozen of us learned about water and bugs, climate change and nanoparticle pollution.

Maggie Zimmer opened up the equipment box for her show and tell of the hydrology experiment.

At the first stop, in the Edeburn Division south of Hillsborough, Nicholas School graduate student Maggie Zimmer showed us a densely instrumented watershed for studying how a raindrop reaches a stream. A little valley of 130 hectares is studded with wells and dammed by a weir that measures every drop flowing out of the watershed. Zimmer and her thesis advisor Brian McGlynn are trying to get a handle on how a drop of water falling on a leaf or the ground eventually makes its way through several feet of soil and clay, in and around chunks of old rock, to the stream.

It’s not as simple as you think, says Zimmer, who has hand-augured 35 test wells in the study area and spent many dark, wet nights tending to her delicate equipment. For example, the rain gauge measures .01 millimeters at a time!

Across the road from the hydrology lab, we visited a global warming forest built by Jim Clark’s research team and overseen by lab manager Jordan Siminitz.

Jordan Siminitz showed us inside one of the warming forest test chambers.

There are 24 plastic enclosures for studying how temperature increases in the soil might affect the growth of young trees. The warming scenarios were produced by a network of propane-heated pipes under the soil in each enclosure. The funding that built the site and operated it for four years has stopped, but the trees are still there and the team is hopeful they can restart the experiment.

Here and in Harvard Forest, the team was looking at soil temperature increases of 3 degrees or 5 degrees Celsius. The surprising finding out of four years of data was that southern tree species seemed to be more adversely affected by the temperature increase than northern species.

“Long term research like this is really hard to get funding for,” Childs said. But without long term studies, we won’t know much about what to expect from climate change. Incidentally, NC State was conducting a parallel study of ants and warmer soils in the same experimental booths, but they’ll be shutting down this year as well.

Duke Forest Director Sara Childs checked out a pickled Southern Pine Beetle.

At the next stop, we found nattily uniformed NC Forest Service ranger Philip Ramsey standing next to an elaborate plastic contraption like 10 black funnels in a series leading down to a reservoir of antifreeze at the bottom. It’s a pheromone trap for the Southern Pine Beetle and its predator, the Clerid beetle. All is well with those bugs for now, but the devastating enemy of ash trees, the Emerald Ash Borer, is on the march and due to arrive any month now, Ramsey said, passing around pickled specimens of the bugs for our inspection.

Our last stop was an update on the nanotechnology test site called the mesocosm facility – 30 boxes filled with water, silt and plant life. They’re meant to mimic a tiny slice of a shoreline ecosystem to see how various nanoparticle materials are taken up by plant and animal life.

Steve Anderson (at right) explained the mesocosm test chambers to the tour group.

Research analyst Steve Anderson from Emily Bernhardt’s lab explained the latest experiments on what happens to all the poisonous stuff infused into anti-bacterial socks and pressure-treated lumber. The good news so far is that nanoparticies don’t seem to get taken up by ecosystems as readily as some had feared.

This isn’t really forest research per se, but where else are you going to put 30 big bunkers of mud, surrounded by an electrified raccoon fence, a super-fine frog fence and a Quonset hut enclosure for the cooler months?

Duke Forest houses 71 research projects at the moment, 16 of them started in just the last year. We’ll look forward to more fun discoveries on next year’s tour!

Follow Duke Forest on Facebook or subscribe to their updates to catch this and other tours.

Post by Karl Leif Bates

Mapping the Pathways of Least Resistance

By Karl Bates

On November 18, 2015

In Cancer, Guest Post, Lecture, Medicine

Cancer is a notoriously slippery target. It can assume multiple genetic identities, taking a different pathway whenever it needs to dodge the latest treatment. A recent study found that just a single, tiny tumor can contain more than a million distinct mutations, priming it for resistance.

$A series of brain-scans on one patient whose brain tumor bounced back repeatedly despite surgery, chemotherapy and radiation. (Fujimaki T et al. “Effectiveness of interferon-beta and temozolomide combination therapy against temozolomide-refractory recurrent anaplastic astrocytoma.” doi:10.1186/1477-7819-5-89)$

A series of brain-scans on one patient whose tumor (white) bounced back repeatedly despite surgery, chemotherapy and radiation. (Fujimaki T et al. “Effectiveness of interferon-beta and temozolomide combination therapy against temozolomide-refractory recurrent anaplastic astrocytoma.” doi:10.1186/1477-7819-5-89)

So, while one treatment might be able to wipe out most of the cancer cells, the few that remain with the right genetic makeup will go on to forge a resistance.

Such resistance is a huge problem and one of the reasons that cancer is on its way to becoming the number one killer disease in the United States. By the end of this year, cancer will kill nearly 600,000 Americans and millions more around the world.

Kris Wood, Ph.D., spoke about the challenges of combating cancer drug resistance at the Basic Science Day on Nov. 16. The annual event brought together faculty, staff, trainees, and students to celebrate basic science research and to encourage collaborations. During the day, attendees heard TED-length talks from faculty members studying a wide range of topics, from vocal learning to asexual reproduction.

“My lab is most interested in the basic question of what are the things that cancer cells can do that allow them to survive in what should be toxic environments created by drug treatments,” said Wood, an assistant professor of pharmacology and cancer biology. “By understanding how cancer cells survive in drug environments, we might be able to both predict those patients who will respond well and respond poorly to treatments, and also design combination therapies that could work more effectively.”

Kris Wood is an assistant professor of pharmacology and cancer biology.

Wood said that knowing that so many different genetic alterations can lead to resistance might make researchers wonder what chances they have of ever stopping a tumor.

But he thinks there is reason to be optimistic, because these myriad mutations seem to function by altering a discrete set of pathways. In turn, many of these pathways seem to create the same kinds of effects in cells – chiefly, fueling growth and shirking death. Targeting the effects that enable resistance could bring about better ways to treat cancers.

For example, half of melanomas are driven by mutations in a gene called BRAF. Wood began to map out the different drug resistance pathways that are controlled by the BRAF signaling molecule. He found that many of these pathways converge on another signaling molecule called MYC, which is known to promote cell proliferation.

When Wood blocked MYC in drug-resistant melanoma cells, he found that it could make them sensitive to further rounds of chemotherapy. He also found that suppressing MYC in melanoma cells before treatment could dramatically delay the time that it takes for resistance to emerge.

Mutant tumor cells (brown) in a brain metastisis of malignant melanoma. BRAF is stained. (Image by Jensflorian via Wikimedia Commons.)

“MYC is a complicated beast, and there are lots of things it can do,” said Wood. “I think there are some promising strategies for inhibiting MYC, which could lead to intelligent therapies that target resistance.”

Guest post by Marla Vacek Broadfoot Ph.D.

Fisticuffs Among the Mantis Shrimp

By Karl Bates

On September 23, 2015

In Animals, Biology, Students

When mantis shrimp (Stomatopoda) dispute territory or mating rights, they use the tools at hand – namely two super-sonic bludgeons powerful enough to dismember a live crab or break through a clam shell.

Mantis shrimp are pugnacious pugilistic crustaceans . (Photo by Nazir Amin via Wikimedia Commons.)

Mantis shrimp are pugnacious and pugilistic. (Photo by Nazir Amin via Wikimedia Commons.)

Fortunately, they’ve developed a way to use these deadly clubs on each other without causing too many fatalities. In a ritualized battle called “telson sparring,” the combatants take turns hammering on each other’s tail-plate, which is raised up like a shield.

Graduate student Patrick Green watched more than 30 such contests in captive Panamanian mantis shrimp to discover that it wasn’t the shrimp who hit hardest who won the bout, but the one who hit the most frequently.

Green and his Ph.D. supervisor, biology professor Sheila Patek, hypothesize that the ritualized fighting could be a display of overall vigor and tenacity rather than outright punching power.

CITATION: “Contests with deadly weapons: telson sparring in mantis shrimp (Stomatopoda),” Green PA, Patek SN. Biology Letters, Sept. 2015. DOI:10.1098/rsbl.2015.0558

[youtube https://www.youtube.com/watch?v=psnvOqtRmzI]

Post by Karl Leif Bates, Director of Research Communications

Student Ideas Have a Place to Call Home

By Karl Bates

On September 3, 2015

In Biomedical Engineering, Computers/Technology, Engineering, Science Communication & Education, Students

Student project teams have become an important part of engineering education at Duke and elsewhere in recent years, but our campus wasn’t always the easiest place for them to work.

DukeMakers showed off a 3D-printed replica of Duke Chapel in the same blue as its construction tarping.

When the robotic submarine team needed to test for leaks in their craft, “we used to roll a bin down the hallway at CIEMAS and fill it up at the water fountain,” said Will Stewart, a junior on the club.

Stewart was showing off his team’s shiny new workroom in The Foundry, a purpose-built 7,600-square-foot space on two levels in the basement of Gross Hall. It has a huge industrial sink.

The Foundry’s airy main workspace was once the home to grimy, ugly machinery that sustained Gross Hall.

Throughout the Foundry, lockers for gear double as whiteboards and sturdy butcher block tables stand ready to take any pounding, grinding and soldering the students can dream up.

In addition to the dedicated spaces for the larger project teams. there is plenty of meeting space and shop space for optics and electronics and some light machining.

Originally the home to big, ugly utilities for the one-time chemistry building, the Foundry space was converted for student use with input from students and faculty representing the Pratt School of Engineering, the Innovation Co-Lab, Duke Innovation and Entrepreneurship, the Nicholas School of the Environment, the Physics Department, and Gross Hall neighbors the Energy Initiative and the Information Initiative.

“It’s amazing that what was actually an ugly space in the basement could turn into a beautiful space for students,” Interim Engineering Dean George Truskey said in brief remarks.

Owen Chung demonstrated IEEE’s robo drink mixer that can combine six different fluids on command from an iPhone app.

The Electric Vehicle Club is looking forward to having one good space, rather than six cramped rooms spread around Hudson Hall to build their super-efficient carbon fiber prototypes. “So far, what we have fits, but we’re actually looking for more space,” said club president Charlie Kritzmacher. “We’re a pretty big club.”

By Karl Leif Bates, Director of Research Communications

Four-Fifths of a Banana is Better than Half

By Karl Bates

On August 24, 2015

In Animals, Behavior/Psychology, Guest Post, Neuroscience, Students

Fractions strike fear in the hearts of many grade schoolers – but a new study reveals that they don’t pose a problem for monkeys.

Even as adults, many of us struggle to compute tips, work out our taxes, or perform a slew of other tasks that use proportions or percentages. Where did our teachers and parents go wrong when explaining discounts and portions of pie? Are our brains simply not built to handle quantitative part-whole relationships?

Fractions and logical relationships are some of the things a wild macaque might think about while grooming and being groomed. (image copyright Lauren Brent)

To try to answer these questions, my colleagues and I wanted to test whether other species understand fractions. If our fellow primates can reason about proportions, our minds likely evolved to do so too.

In our study, which appears online in the journal Animal Cognition, Marley Rossa (Trinity 2014), Dr. Elizabeth Brannon, and I asked whether rhesus monkeys (Macaca mulatta) are able to compare ratios.

We let the monkeys play on a touch-screen computer for a candy reward. First we trained them to distinguish between two shapes that appeared on the screen: a black circle and a white diamond. When they touched the black circle, they heard a ding sound and received a piece of candy. But when they touched the white diamond, they heard a buzz sound and did not get any candy. The candy-loving monkeys quickly developed a habit of choosing the rewarding black circle.

$http://www.free-training-tutorial.com/math-games/fraction-matching-equivalent1.html$

Fractions example taken from sheppardsoftware.com

Next we introduced fractions. We showed two arrays on the screen, each with several black circles and white diamonds. The monkeys’ job was to touch the array having a greater ratio of black circles to white diamonds. For example, if there were three black circles and nine white diamonds on the left, and eight black circles and five white diamonds on the right, the monkey needed to touch the right side of the screen to earn her candy (8:5 is better than 3:9).

We didn’t always make it so easy, though. Sometimes both arrays had more black circles than white diamonds, or vice versa. Sometimes the array with the higher black-circle-to-white-diamond ratio actually had fewer black circles overall. They needed to find the largest fraction of black circles. For example, if there were eight black circles and 16 white diamonds on the left (8:16), and five black circles and six white diamonds on the right (5:6), the correct answer would be the latter, even though there were more black circles on the left side. That is how we made sure that monkeys were paying attention to the relative numbers of shapes in both arrays.

The monkeys were able to learn to compare proportions. They chose the array with the higher black-circle-to-white-diamond ratio about three-quarters of the time. Impressively, when we showed them new arrays with number combinations they had never seen before, the monkeys still tended to select the array with the better ratio.

Our results suggest that monkeys understand the magnitude of ratios. They also indicate that monkeys might be able to answer another type of question: analogies. These four-part statements you may have seen on standardized tests take the form “glove is to hand as sock is to foot.”

This kind of reasoning requires not only recognizing the relationship between two items (glove and hand) but also how that relationship compares with the relationship between the other two items (sock and foot). Understanding the relationships between relationships — that is, second-order relationships — was believed to require language, making it possibly a uniquely human ability. But in our study, monkeys successfully determined the relationship between two fractions – each one a relationship between two numbers – to make their choices.

If monkeys can reason about ratios and maybe even analogies, our minds are likely to have been set up with these skills as well.

The next step for this line of research will be to figure out how best to employ these in-born abilities when teaching proportions, percentages, and fractions to human children.

CITATION: “Comparison of discrete ratios by rhesus macaques (Macaca mulatta)” Caroline B. Drucker, Marley A. Rossa, Elizabeth M. Brannon. Animal Cognition, Aug. 19, 2015. DOI: 10.1007/s10071-015-0914-9

Guest post by graduate student Caroline B. Drucker. Caroline is curious about both the evolutionary origins and neural basis of numerical cognition, which she currently studies in lemurs and rhesus monkeys.