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

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Who Makes Duke? Visualizing 50 Years of Enrollment Data

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Millions of data points. Ten weeks. Three Duke undergraduates. Two faculty facilitators. One project manager and one pretty cool data visualization website.

Meet 2020 Data+ team “On Being a Blue Devil: Visualizing the Makeup of Duke Students.”

Undergraduates Katherine Cottrell (’21), Michaela Kotarba (’22) and Alexander Burgin (’23) spent the last two and a half months looking at changes in Duke’s student body enrollment over the last 50 years. The cohort, working with project manager Anna Holleman, professor Don Taylor and university archivist Valerie Gillispie, used data from each of Duke’s colleges spanning back to 1970. Within the project, the students converted 30 years of on-paper data to machine-readable data which was a hefty task. “On Being a Blue Devil” presented their final product during a Zoom-style showcase Friday, July 31: An interactive data-visualization website. The site is live now but is still being edited as errors are found and clarifications are added.

The cover page of the launched interactive application.

The team highlighted a few findings. Over the last 20 years, there has been a massive surge in Duke enrollment of students from North Carolina. Looking more closely, it is possible that grad enrollment drives this spike due to the tendency for grad students to record North Carolina as their home-state following the first year of their program. Within the Pratt School of Engineering, the number of female students is on an upward trend. There is still a prevalent but closing gap in the distribution between male and female undergraduate engineering enrollment. A significant drop in grad school and international student enrollment in 2008 corresponds to the financial crisis of that year. The team believes there may be similar, interesting effects for 2020 enrollment due to COVID-19.

However, the majority of the presentation focused on the website and all of its handy features. The overall goal for the project was to create engaging visualizations that enable users to dive into and explore the historic data for themselves. Presentation attendees got a behind-the-scenes look at each of the site’s pages.

Breakdown of enrollment by region within different countries outside of the United States.

The “Domestic Map” allows website visitors to select the school, year, sex, semester, and state they wish to view. The “International Map” displays the same categories, with regional data replacing state distributions for international countries. Each query returns summary statistics on the number of students enrolled per state or region for the criteria selected.

A “Changes Over Time” tab clarifies data by keeping track of country and territory name changes, as well as changes in programs over the five decades of data. For example, Duke’s nursing program data is a bit complicated: One of its programs ended, then restarted a few years later, there are both undergraduate and graduate nursing schools, and over a decade’s worth of male nursing students are not accounted for in the data sets.

The “Enrollment by Sex” tab displays breakdown of enrollment using the Duke-established binary of male and female categories. This data is visualized in pie charts but can also be viewed as line graphs to look at trends over time and compare trends between schools.

“History of Duke” offers an interactive timeline that contextualizes the origins of each of Duke’s schools and includes a short blurb on their histories. There are also timelines for the history of race and ethnicity at Duke, as well as Duke’s LGBTQ history. Currently, no data on gender identity instead of legal sex was made available for the team. This is why they sought to contextualize the data that they do have. If the project continues, Cottrell, Kotarba, and Burgin strongly suggest that gender identity data be made accessible and included on the site. Racial data is also a top priority for the group, but they simply did not have access to this resource for during the duration of their summer project.  

Timeline of Duke’s various schools since it was founded in the 1830’s.

Of course, like most good websites, there is an “About” section. Here users can meet the incredible team who put this all together, look over frequently asked questions, and even dive deeper into the data with the chance to look at original documents used in the research.

Each of the three undergrads of the “On Being a Blue Devil” team gained valuable transferable skills – as is a goal of Duke’s Data+ program. But the tool they created is likely to go far beyond their quarantined summer. Their website is a unique product that makes data fun to play with and will drive a push for more data to be collected and included. Future researchers could add many more metrics, years, and data points to the tool, causing it to grow exponentially.

Many Duke faculty members are already vying for a chance to talk with the team about their work.  

Tracking Tiny Moving Targets

This squiggly line shows the path taken by a snippet of DNA as it might move around within the soupy interior of a cell. Duke’s Kevin Welsher and colleagues have developed a technique that turns a microscope into a ‘flight tracker’ for molecules, making it possible to follow the paths of viruses and other particles thousands of times smaller than the period at the end of this sentence. Until now, such techniques have required particles to be tethered to make sure they stay within the field of view. But the Welsher lab has developed a way to lock on to freely moving targets and track them for minutes at a time.

Why Ruffed Lemurs (and Their Gut Microbes) Need to Eat Greens

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We offered fruit-eating ruffed lemurs at the Duke Lemur Center fresh lettuce each afternoon for 10 days. They happily ate it and their gut microbiomes shifted, suggesting that leafy greens could be incorporated into the lemurs’ standard dietary regimen to boost foraging opportunity and fiber intake.

Red-ruffed lemurs and black-and-white ruffed lemurs are some of Madagascar’s most iconic wildlife. Sporting a long snout and a neck ruff to rival those of the Elizabethan court, these primates naturally live in the rainforests, where they mostly eat fruits and flowers, and make their living as seed dispersers and pollinators.

Ruffed lemurs really like romaine lettuce and their gut bugs do too! (Lydia Greene)

Ruffed lemurs also live in zoos worldwide, where they are given fruit-rich diets to match those foraged by their wild peers. But scientists are starting to realize that the fruit eaten by wild lemurs is quite different from the domesticated fruit provided at zoos. Wild fruits are seedy, pulpy, and thick-skinned, whereas orchard fruits are fleshy, plump, and sweet. From a nutritional standpoint, wild fruits contain more fiber, whereas orchard fruits contain more sugar. 

Our team wondered if a fiber boost might benefit Duke’s ruffed lemur colony. But would these fruit-loving lemurs eat their veggies?  

Cue the salad bar.

To test this idea, we offered ruffed lemurs at the Duke Lemur Center a lot of lettuce. Lettuce seemed like a pretty palatable way to stimulate foraging behavior, while boosting fiber intake.

With help from the research department, we offered 19 ruffed lemurs 150-200 grams of romaine lettuce each day, which is about double the weight of their standard diet. We repeated this regimen every day for 10 days, while recording the lemurs’ feeding behavior and collecting fecal samples for gut microbiome analysis. Because gut microbes are chiefly responsible for converting plant fiber into energy for the lemurs, measuring changes to the lemurs’ microbiomes offered a way to ‘see’ the impact of lettuce consumption.

It turns out that ruffed lemurs really like lettuce. They consistently ate lettuce every day and showed no decline in consumption across the study. Younger animals ate more lettuce than did geriatric lemurs, but all lemurs spent more time crunching on lettuce stalks than the leaves.

And their gut microbiomes responded. We noted two microbes that were more abundant on the lettuce diet: a known fiber digester from the Ruminococcaceae family, and a microbe known for its positive association with host health in other animals called Akkermansia.

Despite their classification as fruit eaters, ruffed lemurs readily eat lettuce. We think lettuce can be used to extend the lemurs’ foraging time while boosting dietary fiber. And it might just help replicate the lifestyles experienced by wild ruffed lemurs in their native Malagasy rainforests.     At the Duke Lemur Center, lettuce is now a routine item offered to ruffed lemurs (and other species too!). Next time you come out for a tour (once it’s safe to do so), you might get to see them crunching away on their new favorite snack!

( Read our paper here: https://onlinelibrary.wiley.com/doi/abs/10.1002/zoo.21555 )

Guest Post by Lydia Greene Ph.D., an NSF-sponsored postdoctoral fellow in biology working at the Duke Lemur Center.

Researchers created a tiny circuit through a single water molecule, and here’s what they found

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Graphic by Limin Xiang, Arizona State University

Many university labs may have gone quiet amid coronavirus shutdowns, but faculty continue to analyze data, publish papers and write grants. In this guest post from Duke chemistry professor David Beratan and colleagues, the researchers describe a new study showing how water’s ability to shepherd electrons can change with subtle shifts in a water molecule’s 3-D structure:

Water, the humble combination of hydrogen and oxygen, is essential for life. Despite its central place in nature, relatively little is known about the role that single water molecules play in biology.

Researchers at Duke University, in collaboration with Arizona State University, Pennsylvania State University and University of California-Davis have studied how electrons flow though water molecules, a process crucial for the energy-generating machinery of living systems. The team discovered that the way that water molecules cluster on solid surfaces enables the molecules to be either strong or weak mediators of electron transfer, depending on their orientation. The team’s experiments show that water is able to adopt a higher- or a lower-conducting form, much like the electrical switch on your wall. They were able to shift between the two structures using large electric fields.

In a previous paper published fifteen years ago in the journal Science, Duke chemistry professor David Beratan predicted that water’s mediation properties in living systems would depend on how the water molecules are oriented.

Water assemblies and chains occur throughout biological systems. “If you know the conducting properties of the two forms for a single water molecule, then you can predict the conducting properties of a water chain,” said Limin Xiang, a postdoctoral scholar at University of California, Berkeley, and the first author of the paper.

“Just like the piling up of Lego bricks, you could also pile up a water chain with the two forms of water as the building blocks,” Xiang said.

In addition to discovering the two forms of water, the authors also found that water can change its structure at high voltages. Indeed, when the voltage is large, water switches from a high- to a low-conductive form. In fact, it is may be possible that this switching could gate the flow of electron charge in living systems.

This study marks an important first step in establishing water synthetic structures that could assist in making electrical contact between biomolecules and electrodes. In addition, the research may help reveal nature’s strategies for maintaining appropriate electron transport through water molecules and could shed light on diseases linked to oxidative damage processes.

The researchers dedicate this study to the memory of Prof. Nongjian (NJ) Tao.

CITATION: “Conductance and Configuration of Molecular Gold-Water-Gold Junctions Under Electric Fields,” Limin Xiang, Peng Zhang, Chaoren Liu, Xin He, Haipeng B. Li, Yueqi Li, Zixiao Wang, Joshua Hihath, Seong H. Kim, David N. Beratan and Nongjian Tao. Matter, April 20, 2020. DOI: 10.1016/j.matt.2020.03.023

Guest post by David Beratan and Limin Xiang

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