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

Category: Biology Page 2 of 29

Expanding the SCOPE of Medical Education

It may be hard to put your finger on it, but Duke often allows students to connect their classes to something more personal.

The university’s emphasis on interdisciplinary education is a major initiative that colors students’ academic experiences. While there are many examples of these connections between people, classes, fields, and departments, few so tangibly represent those connections like The SCOPES Project, which connects arts and humanities to medical education at Duke.

Beneath the Surface by Mihir Patel, 2022. Image Courtesy of SCOPES.

Art and medicine can exist in entirely different worlds. They can appeal to different people and tell different stories. But why be simple when you can be, well… stunning? They can be integrated to form something powerful, and that’s precisely what SCOPES leadership members Isa DeLaura, Raluca Gosman, Mason Seely, David Stevens, and Lindsay Olson aimed to do. 

“It is encouraging as an upperclassman who previously participated in this program to see rising students continue the tradition of incorporating the humanities into medical practice,” Mason Seeley says. The generational aspect of the project seems to contribute to its personality; participants bring their own perspectives to their work only to walk away with dozens more. 

“Having a creative outlet has helped me process interactions with patients and the difficulties of the profession, and celebrate happy moments as well,” says Isa DeLaura.

“The goal is to give artists creative freedom to explore their relationships with their patients with whatever medium and in whatever style works best for them. As such, every year the feel is entirely based on the decisions of the artists.”

Isa DeLaura, MS3+

David Stevens insists that the artists “resist… forces of depersonalization in compelling and beautiful ways.”

The project is inspired and supported by yet another interdisciplinary Duke initiative called APPLE (Appreciating Patient Perspectives through Longitudinal Encounters), which connects medical students with patients living with chronic illnesses. The artists/medical students/empaths-in-training then attended multiple creative workshops and developed art pieces to reflect their patients’ personal experiences. But this year’s 6th annual SCOPES exhibition looks a bit different from past years’ (which are conveniently available online for your viewing pleasure).

Having attended many an art opening myself, I am unashamed to say that much of my enjoyment comes from the cheeseplates (and the excitement in the air, but that’s besides the point). Some exhibitions opt for a traditional charcuterie, some marked Kirkland Signature and others displayed on a handmade butcherblock. The point of fingerfoods is to encourage the attendees to stand up, walk around, and interact with the masses. But it also encourages attendees to “just stop by,” making the affair all the less intimate.

Following limitations on group gatherings Duke enforced during COVID, the SCOPES team decided to apply their newfangled interdisciplinary/revolutionary/innovative thinking to the art opening itself: They held a banquet. 

“I loved the way this turned out,” says DeLaura. “It was very personal and made for great discussion and comradery.” 

Fences, Rivers, Walls by Taylor Yoder, 2022. Image Courtesy of SCOPES.

“SCOPES has provided an opportunity to reflect on my experiences as a first-year medical student while also exploring new ways to combine various art forms to create my vision,” says Taylor Yoder, who created Fences, Rivers, Walls, pictured above. “I hope to continue shooting film throughout my medical education and career.”

I was particularly (although wrongfully) surprised about the variety in the exhibit. While the artists attended the same workshops and worked with patients through the same program, they took radically different approaches to their creations. Esme Trahair, a second-year medical student, was a humanities major in undergrad. Her piece combines historical perspectives with modern (although antiquated) mechanisms, emphasizing “the importance of remembering and learning from historical, outdated medical teachings.”

For the Record by Esme Trahair, 2022. Image Courtesy of SCOPES.

The work features a variety of perspectives, but also some clear motifs that could be key takeaways for future medical providers. Like Yoder, artist Kreager Taber explores the patient’s value of “home.” Exploring these motifs could allow for more personal, “upstream” healthcare. 

This year’s SCOPES exhibition is held in the Mars Gallery in the Duke University Hospital Concourse. It is an initiative of the Trent Center for Bioethics, Humanities & History of Medicine at the Duke University School of Medicine. It will be on display August 9-September 29, and available for viewing online at this link. 

P.S. If you are an MS1 student interested in participating in SCOPES, I have a link for you!

Post by Olivia Ares, Class of 2025

Predicting What Extinctions Could Mean for Lemurs and the Forests They Call Home

New research shows that lemurs and their food trees are tightly linked in ecological networks, and that the extinction of lemurs will have cascading effects on ecosystem functions.

The Critically Endangered black-and-white ruffed lemur, Varecia variegata, is one of the lemurs that eats the most fruit. When they consume the fruit, they pass the whole far from the mother tree, effectively aiding in seed dispersal. Photo credit: Laura De Ara

Lemurs are the primates found only on Madagascar. They are unique in many ways, and like many organisms, they fit in complex ecological networks. These networks include interactions between lemurs and their food trees. Many interactions are beneficial, or mutualistic; for example, lemurs eat the fruits of trees and disperse their seeds, providing a critical service to the trees. If lemurs go extinct — 98% of species are threatened with extinction due to human activities — the links in the ecological network will be severed, with potentially negative impacts on the trees.

Research published in the Journal of Animal Ecology by Ph.D. student Camille DeSisto, of the Duke University Nicholas School of the Environment, and James Herrera, from the Duke Lemur Center, shows how tightly linked lemurs and trees are in their interaction networks, and the negative impacts of extinction on network resilience. If lemurs do in fact disappear, many trees will be left without a way to disperse their seeds, and may not be able to reproduce effectively.

DeSisto and Herrera used advanced techniques in social network analysis, including exponential random graph models, to test which traits of lemurs and trees predict their probability of interaction. The lemurs with the highest probability of interactions with trees were large, fruit-eating species with a short gestation length, occurring in arid habitats, and with a threat status of Least Concern. Closely related plants were more likely to interact with the same lemur species than distantly related plants, but closely related lemurs were not more likely to interact with the same plant genus.

Simulated lemur extinction tended to increase network structure in some properties, including connectance (% of realized interactions out of all possible interactions) and modularity (how many unique cliques or subcommunities form in the network), but decrease nestedness (the tendency for specialists which feed on only a few trees to be a subset of generalists which feed on many trees) and robustness (tolerance to future extinctions), compared to pre‐extinction networks. Networks were more tolerant to plant than lemur extinctions.

The silky sifaka, Propithecus candidus, is one of the most endangered primates in the world. Unlike some lemurs, the sifaka have antagonistic relationships with trees, eating leaves and prey on seeds, rather than pass them intact. Photo credit: Laura De Ara.

By simulating the loss of lemur and plant species, the authors could predict how network structure will erode over time if threatened lemurs and trees go extinct. The results showed that if the most well-connected lemurs in the network were to disappear, the percentage of trees with interactions would quickly decline, compared to scenarios in which lemurs were removed randomly or if the least-well connected lemurs went extinct. Given the threat status and geographic range size of lemurs, the percentage of trees that would lose their interacting lemurs would be greater than that expected if lemur extinctions were random.

The bamboo lemur, Hapalemur occidentalis, is a highly specialized species, eating mostly bamboo leaves. They do, however, occasionally eat fruits, and often spread the seeds effectively. Photo credit: Laura De Ara

Results also showed that if lemurs go extinct, the resilience of the networks to further disturbance would decrease. This indicates that the current links between lemurs and trees are critical to the stability of these complex ecological networks.

To prevent the loss of key ecosystem functions like seed dispersal, it is critically important to protect lemurs and trees, which depend so crucially on one another for survival. DeSisto is currently conducting field research in Madagascar, studying how well seeds germinate when eaten by lemurs. She created a tree nursery in the forest to grow the seeds obtained from lemur feces, and already has several species germinating. Interestingly, she is also showing how lemurs disperse the seeds of vines, which are an important yet understudied food source when tree fruits are not available. She will continue her research across multiple seasons, to determine how changes in plant phenology affect seed dispersal patterns.

Author Camille DeSisto and assistant Feno Telessy examine the seeds germinating from lemur feces.
Amazingly, seeds from lemur feces are already germinating after only one month. Some tree seeds take months or even a year before germinating.

Many conservation programs are currently striving to safeguard Madagascar forests and the diverse species found only in these natural habitats. The Duke Lemur Center has an active conservation program in the northeast, called the DLC-SAVA Conservation Initiative. This program takes a community-based approach to conservation, partnering closely with local stakeholders and actors to develop projects that address the needs of both lemurs and people. By co-creating projects that include alternative and sustainable livelihood strategies, both nature and people benefit from conservation. Natural ecosystems provide important services for people, including locally, such as protecting watersheds and pollinators, as well as globally, such as carbon sequestration. Without the native forests, and the lemurs that call those forests home, people would lose the valuable and irreplaceable services forests provide.

CITATION: “Drivers and Consequences of Structure in Plant–Lemur Ecological Networks,” Camille DeSisto and James Paul Herrera. Journal of Animal Ecology, July 15, 2022. DOI: 10.1111/1365-2656.13776.

Behold: the Cell’s Skeleton in Motion

To many of us, cells are the building blocks of life, akin to bricks or Legos. But to biologist Regan Moore, a former Ph.D. student in Dan Kiehart’s lab at Duke, cells are so much more: they’re busy construction sites, machinery and materials moving about to build and shape the body. And now, new live imaging techniques make it possible to watch some of the nano-scale construction in action.

In time-lapse videos published this month, Moore, Kiehart and colleagues were able to peer inside cells as they filled a hole in the back of a developing fruit fly, a crucial step in the fly’s development into a larva. The process is coordinated with help from a thin mesh of protein fibers just under the cell surface, each one 10,000 times finer than a human hair. The fibers help the cells hold their shape, “kind of like rebar in concrete,” Moore said.

But unlike rebar, she added, “they’re constantly moving and changing.” Normally, features like these are too small and quick to see with conventional microscopes, which can only take a few images a second or are too out-of-focus. So Kiehart’s team used a technique called super-resolution fluorescence microscopy to track individual fibers with nanoscale resolution.

By watching the “rebar of the cell” at work during this hole-closing process in fruit flies, the researchers hope to better understand wound healing in humans, and what goes awry for children with birth defects such as cleft lip and spina bifida.

LEARN MORE: “Super-resolution microscopy reveals actomyosin dynamics in medioapical arrays,” Regan P. Moore, Stephanie M. Fogerson, U. Serdar Tulu, Jason W. Yu, Amanda H. Cox, Melissa A. Sican, Dong Li, Wesley R. Legant, Aubrey V. Weigel, Janice M. Crawford, Eric Betzig, and Daniel P. Kiehart. Molecular Biology of the Cell, July 15, 2022. DOI: 10.1091/mbc.E21-11-0537

Modeling Biology: Ruby Kim’s Research on the Math of Physiological Cycles

What lies at the intersection of mathematics and biology? Freshly-minted math PhD Ruby Kim and her work on mathematically modeling human dopamine cycles.

Ruby Kim, recent Duke PhD graduate

Kim’s work has centered around her creation of a math model to predict how a person’s dopamine levels ebb and flow over the course of a day “to understand the general mechanics of how disruptions in the (biological) clock lead to disruptions in dopamine.”

She said there is a pretty long history of mathematicians using differential equations to see how different clock genes and proteins change over the course of a day’s circadian cycle. Yet, no previous models have connected the circadian clock – controlled by the brain’s suprachiasmatic nucleus – to dopamine levels. And Kim tells me that work suggesting dopamine changes throughout the day are likely controlled by the internal circadian clock itself is “relatively new.”

The first step in Kim’s work was validating scientists’– or “experimentalists,” as Kim dubs them –  hypotheses about dopamine and dopaminergic enzyme cycling.

Many physiological processes are controlled via circadian rhythms and the internal clock in humans, as well as other organisms.

“But I’d like this work to help experimentalists go one step further and be able to test out hypotheses more easily.” For example, Kim says that her model has the potential to reveal other fascinating phenomena, such as how drug treatments or different genetic mutations may impact circadian rhythm or dopamine. This is thanks to the multifaceted layers of Kim’s model.

“From a mathematical perspective, the math model is very interesting. It has a lot of interesting dynamics,” she says. “Not only does it show nice, 24-hour rhythms, it shows both steady state behavior… but then also behavior that’s really wild – something called quasi-periodic behavior, where the internal clock is significantly different than the external 24-hour light-dark cycle.”

“This leads to oscillatory behavior that’s not periodic,” she says. These sorts of quasi-periodic behaviors have been observed in experiments and misunderstood, but they can be computed.

Kim emphasized the experimental and clinical implications of her work. Dopamine is involved in learning and motivation and is also linked a plethora of psychiatric conditions like Parkinson’s, ADHD, and schizophrenia. “Patients with these conditions often also experience circadian disruptions,” Kim says. “That’s a pretty big symptom.”

Kim began her academic career in her home state of California at Pomona College as a pre-med math major. “I had always been intrigued by human physiology. And math was one of the subjects I was also pretty drawn to. I just didn’t appreciate it much because throughout high school and the beginning of undergrad, I didn’t see any direct applications,” Kim told me.

The marriage of her love for math with her intrigue in biology actually began at Duke when Kim attended a mathematical biology workshop during the summer after her sophomore year. “I had never heard of math biology before that.”

After working on a brief project to model sleep apnea in infants at the workshop, Kim returned to California and took up math modeling courses in her following semesters of undergrad. One of her professors, Ami E. Radunskaya, PhD, was extremely supportive and introduced Kim to a lot of “cool biological problems.” Kim went on to do research with Radunskaya, modeling tumor-immune interactions. This experience, Kim says, “kind of just threw me into academia.” The project gave way to an undergraduate thesis with Radunskaya that analyzed the long-term behavior of this tumor growth and treatment model.

Radunskaya then suggested that Kim pursue grad school. “I kind of applied on a whim,” Kim said, “It wasn’t something I had specifically imagined for myself.” Kim mentioned how no one from her home community had really ever gone to grad school and so it was not something she had ever “explicitly” thought about before.

Using mathematics to fight cancer | Department of Mathematics | University  of Washington
An abstract of Radunskaya’s work on mathematical modeling and understanding tumor-immune interactions to address cancer.

In her search for a graduate program, Kim applied to math programs, as well as those that were interdisciplinary. “I ended up choosing Duke because I really liked my advisor,” Kim told me. While Kim’s advisor Michael Reed, PhD “does a lot of interesting math,” Kim wanted to work with him because math isn’t his focus – understanding “really complex biological systems using mathematical language is.”

“A lot of times you see people who do things at the intersection of math and biology that are more motivated from a mathematical standpoint … that’s just not what I’m interested in personally. I’m very interested in finding an interesting biological problem and then applying whatever mathematical tools I have.”

While at Duke, Kim was foundational to founding the university’s chapter of the Association for Women in Math (AWM). During her undergrad, Kim “had a really great experience with AWM,” finding both a community of women mathematicians and a network of women professors who were involved in the chapter.

At Duke, there wasn’t a chapter “but quite a few people who were interested in starting and being part of one.” This organization, which is open to people of any gender identity, heads mentorship programming that brings undergrads, grad students, postdocs, and professors together, organizes conferences, and contributes to their central focus of community building in math.

Outside of her research, Kim spends most of her free time taking care of foster pups, which she describes as “extremely rewarding but also very tiring.” Her most recent foster, a four-month-old puppy, eavesdropped on our interview as he took a nap.

This fall, Kim will begin a post-doc with the University of Michigan’s math department as she “wanted to keep studying circadian rhythms with faculty who are really great in that area.”

Post by Cydney Livingston, Class of 2022

Vernal, Ephemeral, Spring Beauty by Any Other Name

Nicki Cagle, Ph.D., with perfoliate bellwort, an ephemeral forest plant also known as wild oats (Uvularia perfoliata).

“Ephemeral” is one of my favorite words. It conjures up images of vernal pools and fireflies and flowers in spring. It comes from ephēmeros, a Greek word meaning “lasting a day.” English initially used it in a scientific sense, to refer to fevers and then in reference to short-lived organisms like flowers or insects. Today “ephemeral” is most often used to describe anything fleeting or short-lived.

The term “spring ephemeral,” for instance, refers to flowers that are visible for only a short time each spring before they disappear.

Nicki Cagle, Ph.D, a senior lecturer in the Nicholas School of the Environment, led a spring ephemeral workshop in the Korstian Division of Duke Forest on a Friday afternoon in late March. The workshop was hosted by DSER, the Duke student chapter of the Society for Ecological Restoration. We focused on identifying herbaceous plant species and families, particularly spring ephemerals.

“Spring ephemerals are perennials that emerge early in the spring and then grow, reproduce, and disappear from the surface of the forest floor in just a few short weeks,” Cagle explains. We also found several species that aren’t technically ephemerals but still bloom in early spring — before the tree canopy emerges and plunges the floor into shade.

Oxalis violacea, a species of wood sorrel.

The first plant Cagle points out is Oxalis violacea, a type of wood sorrel. “This particular species will have purple flowers,” she says. The genus name, Oxalis, refers to the plant’s oxalic acid content. “You can nibble on it,” but “you don’t want to nibble on it too much.” Oxalic acid, which is also found in common foods like spinach, gives the leaves a pleasant, lemony taste, but it can cause problems if eaten in excess.

Common bluet (Houstonia caerulea).

When we come across a patch of lovely, pale violet flowers with yellow centers, Cagle challenges the workshop participants to determine which family it belongs to. She offers two options: Rubiaceae, a large family that often has either opposite or whorled leaves and four to five petals and which includes familiar plants like coffee, or Violaceae, a very small plant family whose members “tend to have everything in fives” (like petals, stamens, and sepals) and often have basal leaves. Answer: Rubiaceae. This particular species is Houstonia caerulea, the common bluet. Its yellow centers help distinguish it from related species like the summer bluet, tiny bluet, and purple bluet. If anything, Cagle says, the plant’s presence is “an indicator of disturbance,” but it’s still good to have around.

Here’s the little brown jug (Hexastylis arifolia).

Next we come across two species in the Hexastylis genus. They are sometimes called wild ginger, but the name is misleading. Hexastylis species are not related to the ginger you buy in the store, which is in a completely different family. Hexastylis is, however, in the same family as the Asarum genus, which Cagle thinks of as “proper” wild ginger. Asarum and Hexastylis have traditionally been used as food and medicine, but they also contain toxins. According to Cagle, they belong to “one of the few plant families that have fossilized remains in the United States,” even dating back to the late Cretaceous Period.

The two species we see are Hexastylis arifolia, the little brown jug, and Hexastylis minor which looks similar but “tends to have a much more rounded form.” Like many spring ephemerals, Hexastylis is often dispersed by ants. The seeds have elaiosomes, fatty deposits that ants find attractive.

“We have a lot of different violets of varying origins” in this area. According to Cagle, this one is likely to be a common blue violet, Viola sororia.

There’s a patch of violets near the Hexastylis plants. “We have a lot of different violets… of varying origins” around here, Cagle says. Many of the native species have both a purple form and a variety that’s white with purple striping. Other species in the violet family come in different colors altogether, and Cagle says many of those are of European origin.

The Johnny-jump-up pansy, for instance, can have “funkier colors,” like yellow or pinkish purple and is native to Europe and Asia. Violets can be hard to identify. Some species are distinguished mainly by characteristics like the lobes (projections in leaves with gaps between them) or the hairiness of the leaves. The bird’s foot violet and wood violet, for example, “tend to have really deep lobes.”

Cagle says the violet we’re looking at is likely the common blue violet, characterized by smooth leaves and petals, purple or purple-and-white flowers, and rounded or slightly arrow-shaped leaves.

The Cranefly orchid (Tipularia discolor) reproduces later in the year. The purple on the bottom of the leaves, and sometimes on the top as well (see right), helps protect the plant from sunlight and herbivores.

The orchid family, Orchidaceae, is one of the largest families of flowering plants in the world. Many of its members are tropical, including the Vanilla genus, but “we do have a number of native orchids” here as well, including yellow and pink lady’s slipper orchids, putty-root, and the cranefly orchid.

The cranefly orchid, Tipularia discolor, isn’t yet in bloom, but we come across the leaves several times on our walk. According to Cagle, Tipularia discolor “isn’t actually a spring ephemeral” because it reproduces later in the year. However, “it’s ephemeral in its own way,” the leaves disappear by the time it flowers. Cagle says the plant’s scientific name can remind you what to look for: “‘Tip-’ because you’re going to tip this leaf over” to look at the underside and “discolor” because the leaves are a striking purple underneath. Some of the ones we see are purple on top as well. Cagle explains that the purple coloration serves as sunscreen and protection from critters that eat plants.

The plant gets its common name (and its scientific genus name, interestingly) from its delicate flowers, which are supposed to resemble craneflies. When the plant blooms, “the flowers are so delicate and so subtle that most of the time you miss them.” Pollinators like Noctuid moths, on the other hand, find the flowers easily and often. Cranefly orchids even have “specialized seed structures” that “get fused onto insects [such as the moths]… and carried off.”

Rue anemone (Thalictrum thalictroides or Anemonella thalictroides).
Cagle with giant chickweed (Stellaria pubera).

The rue anemone, unlike the cranefly orchid, is a true spring ephemeral. It belongs to a more “primitive” family and has lots of petals in a spiral arrangement. The species is also known as windflower “because they flutter and dance as the breeze comes through.” Cagle mentions that the plant is “usually pollinated by flies and little bees” and serves as an important food source for insects in early spring. But “how do these even exist” in a forest with so many plant-eating deer? Many spring ephemerals, Cagle explains, have “some really potent toxins” that protect them from large herbivores.

We stop briefly to examine perfoliate bellwort, also known as wild oats (Uvularia perfoliata), and giant (or star) chickweed. Chickweed is in the pink family, named not for the color but because “the petals… [look] as if they’re cut by ‘pinking shears,’” which have saw-toothed blades that leave notches in fabric.

Trout lily (Erythronium umbilicatum). According to Cagle, “No spring ephemeral walk is actually complete without finding some trout lilies.”

Near the end of our walk, we find several trout lilies. That’s fortunate. “No spring ephemeral walk is actually complete without finding some trout lilies,” Cagle says.

Unsurprisingly, trout lilies belong to the lily family. “Their flower structure,” Cagle says, “is very symmetrical” with three petals and three sepals. In trout lilies, the sepals resemble petals, too. This particular species is Erythronium umbilicatum. The species name, umbilicatum, refers to its “really long peduncle,” or flower stalk, which “allows the seed to actually touch the ground.” The seed is dimpled, Cagle says, “like a little belly button.” The name “trout lily,” meanwhile, refers to the mottled pattern on the leaves.

Spring beauty (Claytonia virginica), “a quintessential spring ephemeral.”

At the base of a tree near a small river, Cagle points out a flower called spring beauty (Claytonia virginica), “a quintessential spring ephemeral.” Some flowers, like the common bluet we saw earlier, thrive in disturbed areas, but plants like the spring beauty need rich, undisturbed habitat. That makes them good indicator species, species that can help scientists gauge environmental conditions and habitat quality. When a natural area is being restored, for example, scientists can measure restoration progress by comparing the “restoration site” to an undisturbed “reference site.”

According to Cagle, the spring beauty is pollinated by “bee flies… flies that kind of look like bees.” After pollination, the flowers turn pink. Cagle says this is common among ephemerals. One theory is that the color change signifies which flowers have already been pollinated, but others think it’s just a result of senescence, or aging.

Spring beauties are also “photonastic,” meaning they open and close in response to changing light conditions. “There is some evidence that the Iroquois would eat this plant in order to prevent conception,” Cagle says, but today the plant—like many spring ephemerals—is under protection in some areas. Human activities, sadly, have contributed to the decline of too many spring ephemerals.

Alum root (Heuchera americana) near the end of the walk. According to Cagle, its roots can be used “to form mordant for dyes.” Members of the Saxifrage family, which includes alum root, often have five petals, five sepals, and five stamens.

Not all of the plants we saw are spring ephemerals. Some, although they bloom in early spring, “wouldn’t technically be considered ephemeral because their leaves stick around even if their blooms don’t last long.” True ephemerals, on the other hand, “are plants that just seem to disappear off the face of the planet (or the forest floor) after a few weeks,” Cagle says. Only three of the species we found during the workshop are true ephemerals: the windflower, trout lily, and spring beauty. However, these aren’t the only spring ephemerals found in the area. Cagle’s personal favorite is bloodroot, with its “bright white petals” and pollen “that looks like it’s glowing.”

Next time you’re in the woods, keep your eyes out for ephemerals and other early spring flowers, but look quickly. They won’t be here for long.

By Sophie Cox

Post and Photos by Sophie Cox, Class of 2025

Kinsie Huggins: the Future Doctor Who Could Shot-Put

From shot-putting, to helping conduct two research studies, to being selected for a cardiology conference, meet: Kinsie Huggins. She is from Houston, Texas, currently majoring in Biology and minoring in Psychology with a Pre-Med track here at Duke. With such a simple description, one can already see how bright her future is!

“I want to be a pediatrician and work with kids,” Huggins says. “When I was younger, I lived in Kansas, and in my area, there were no black pediatricians. My mother decided to go far to find one and I really bonded with my pediatrician. One day, I made a pact with her in that I would become a pediatrician too so that I can also inspire other little girls like me of my color and other minority groups.”

Having such a passion to let African-American and minority voices be heard, Huggins is also part of the United Black Athletes, using her shot-put platform to make sure these voices are heard in the athletics department.

And while she may be a top-notch sportswoman, she is also just as impressive when it comes to her studies and research. One of her projects focuses on the field of nephrology – the study of kidneys and kidney disease. She and a pediatric nephrologist are currently working on studying rare kidney diseases and the differences in DNA correlating to these diseases.

Kinsie is also a researcher at GRID (Genomics Race Identity Difference), which studies the sickle cell trait in the NCAA. With the sudden deaths of college athletes from periods of over-exhaustion during conditioning, there has been a rise in attention of sickle cell trait and its impact on athletes. At first, the NCAA implemented a policy that made it mandatory for college athletes to get tested for sickle cell in 2010, but some were wary about the lack of scientific validity in such claims. Now, the NCAA has funded GRID to conduct such research.

The difference of Normal red blood cell and sickle cell (CDC).

 “We are analyzing the policy (athletes need to be tested for sickle cell), interviewing athletes in check-ups, and looking at data to see if the policy is working out for athletes and their performance/health,” Huggins explains.

With such an impressive profile, it doesn’t go without saying that Huggins didn’t go unnoticed. The American College of Cardiology (ACC) select high school and college students interested in the field of medicine and have them attend a conference in Washington D.C. to hear about research presentations, groundbreaking results of late-breaking clinical trials, and lectures in the field. Having worked hard, Huggins was selected to be part of the Youth Scholars program from the ACC and was invited to the conference on April 2-4. 

Let’s wish Kinsie the best of luck at the conference and on her future research!

Post by Camila Cordero, Class of 2025

Quorum Sensing: The Social Network of Bacteria

Dr. Bonnie L. Bassler, the Chair of Molecular Biology at Princeton University, is an advocate for diversity in science.

Bonnie Bassler of Princeton University

Throughout her presentation of the Ingrid Daubechies Lecture on Jan. 31 during Research Week, she emphasized that the diversity of her scientific team allowed every lab member to contribute to different steps of the process of studying quorum sensing, a form of microbial communication. (Watch her talk.)

Bacteria are everywhere. They’re sitting at the tables you sit at, burrowing in the clothes you wear and unfortunately, also crawling around on your skin. For a long time, they’ve had a pretty bad reputation, and for good reason! They have caused plagues that have wiped out masses across the globe, driven up breath mint sales by thriving in your mouth and mutated into every biologist’s Boogeyman when you try to kill them with antibiotics – super bugs!

However, the bacterial redemption arc is also quite compelling. “Good guy” bacteria in the gut help us break down food, produce essential vitamins and also sometimes fight off their evil siblings.

So, good or bad, the impact of bacteria in our daily lives is undeniable. But how does a microscopic little being have the capacity to influence the macroscopic world so greatly?

It doesn’t. At least, not by itself.

Lactococcus lactis is one of the starter bacteria in a cheese culture!

A bacterium never works alone because its strength lies in its numbers! Groupwork and communication (as any Pratt star going through recruiting season will swear to their interviewers) are what make bacteria so powerful. A bacterium by its lonesome will act differently than a bacterium surrounded by its daughters, sisters and cousins (bacterial family tree dynamics can get a little unusual).

Knowing that bacteria optimize their behaviors to work efficiently in a group answers the question of how they are so powerful, but it raises another.

How do bacteria know when they have company?

In a world where social media helps us stay connected, it is easy to take rapid status updates for granted. But for tech-deprived microbial colony, how does one member gauge the population of their surroundings? This question is one that Bassler’s lab answered: with a special chemical compound called autoinducers.

Autoinducers are little chemical signaling molecules that each bacterium sends out into its immediate environment. These molecules allow for quorum sensing, or cell-to-cell communication, to take place among bacteria.

Basic quorum sensing: How bacteria know who’s around them. (Nidhi Srivaths)

Every bacterium senses changes in the concentration of these autoinducers in their surroundings. Sensing a sudden increase in autoinducer concentration will change a bacterium’s gene expression, protein synthesis, and consequently, behavior. It will adapt to group behavior, while a bacterium that senses a drop in autoinducers will adapt to individual behavior.

Bacteria not only sense how many others are around them but also who their neighbors are. Autoinducers are universal to both Gram positive and negative bacteria and are unique to the type of bacteria that produce them.

This provides the bacterium with qualitative information on the population of its surroundings. Are they friends or foes?

Quorum sensing also includes nametags so bacteria can tell friend from foe. (Nidhi Srivaths)

In marine vibrio (a genus of Gram-negative bacteria), Bassler’s lab found that quorum sensing could perform intra-species, intra-genus and inter-species identification. This additional information helps the microbes adjust their behavior – from being friendly and supportive towards their relatives to being aggressive and competitive with their enemies.

Bassler provided a real-world perspective on quorum sensing. One species of the vibrio genus, Vibrio cholerae, is responsible for causing Cholera a deadly food and water-borne disease that has plagued low- and middle-income countries for centuries.

When the cholera bacteria enter the host, they are highly virulent and create a sticky biofilm around themselves that helps them clump into aggregates. Their cell density increases with bacterial division until the bacteria sense a certain concentration of autoinducers. Then their gene expression is modified to reduce virulence and biofilm production and the bacterial gene expression patterns shift to escape mechanisms. The bacteria soon break out in large numbers in search of a new host. (Their human host has voluminous, watery diarrhea in response and that becomes the vector for infecting new hosts.)

While the sequence of events that occurred in a cholera infection was known, the discovery of quorum sensing in V. cholerae opens doors for possible treatments, Bassler said. As bacterial communication sets the cycle of infection and division in motion, interfering with the autoinducers produced or disrupting bacteria’s ability to sense them sets the stage for innovative therapies for several infectious diseases.

Quorum sensing is another step towards understanding the world of the tiny microorganisms that influence our world and Bassler and her team are another example of the incredible research that can come from diverse teams in science.

Post by Nidhi Srivaths, Class of 2024

Medicine Under a Microscope

Duke Research Week 2022 featured a range of speakers from across all disciplines. The Lefkowitz Distinguished Lecture on January 31st highlighted some of our favorite things here at Duke Research Blog: ingenuity and perspective. 

Dr. Huda Yahya Zoghbi’s career spans decades; her Wikipedia page sports an “Awards and Honors” section that takes up my entire computer screen. She is a geneticist, neuroscientist, pediatric neurologist, pharmaceutical executive, and literature lover. Her presentation kicked off 2022 Research Week with a discussion of her work on Rett Syndrome. (View the session)

Rett Syndrome is a rare genetic disorder. The gene that researchers identified as the driver of the syndrome is MeCP2, which is especially active in brain cells. Certain mutations of this one gene can be responsible for a loss of speech, development issues, and persistent fidgeting. 

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The MeCP2 protein. Image: Wikipedia Commons

Children with Rett Syndrome faced chronic misdiagnosis, and even with proper care were limited by a lack of research.

Duke’s Dr. Robert Lefkowitz introduced Zoghbi at the beginning of the seminar and explained how she came to become the leading expert on this relatively unknown disorder. After completing medical school in Beirut in the midst of the ravaging Lebanese Civil War, she came to Texas Children’s Hospital, where she was able to observe and diagnose her first case of the syndrome, a process spurred by a simple interest in a newly-published journal article.

Holistic knowledge of Rett Syndrome is completely dependent on genetic research. A mutation on the MeCP2 gene causes errors in transcription, the reading out of DNA in your cells which leads to the production of proteins.

The mutated gene’s MeCP2 protein is then lacking the ability to do its job, which is helping other genes be expressed, or actively transcribed.

It’s a vicious cycle; like when you go to sleep late one night, so you sleep in the next day, then go to sleep late the next night, then sleep in the next day, and so forth.

In order to simulate and measure the effect of different kind of mutations on the MeCP2 gene, Zoghbi and her team studied genetically modified mice. While Rett Syndrome is caused by a lack of MeCP2 function, an overactive MeCP2 gene causes MeCP2 duplication syndrome. Varying degrees of gene efficiency then produce varying degrees of severity in the syndrome’s traits, with fatality at either end of the curve.  

Varying degrees of phenotype severity.

Zoghbi’s talk focused mainly on the mechanics of the disorder on a genetic level, familiar territory to both Nobel Laureate Lefkowitz and Duke Medicine Dean Mary Klotman, who shared some discussion with Zoghbi.

This medicine on a microscale is applicable to treating genetic disorders, not just identifying them. Zoghbi has been able to experimentally correct MeCP2 duplication disorder in mice by modifying receptors in a way that reverses the effects of the disorder.

The symptoms of Rett Syndrome are physical; they present themselves as distinct phenotypes of a subtle difference in genotype that’s too small to see. The field of genetics in medicine is responsible for making that connection.

Post by Olivia Ares, Class 2025

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Materials For a Changing World… What is That?

Everything in our world is made from materials, meaning life is enabled by material development and efficiency. In today’s society, from constant technological revolution to the global pandemic, life as we know it is always evolving. But as the world around us evolves, the materials around us also need to evolve to keep up with current demands. But how? As a part of Duke University’s annual Research Week on Feb. 3, researchers from a multitude of practices offered their wisdom and research.

Moderated by Dr. Catherine L. Brinson, Ph.D., the panel hosted three Duke Scholars and their research on ‘Materials for a Changing World’. “The development of new materials can really be key in solving some of the more critical challenges of our time,” Brinson maintained.

Dr. David Beratan explaining his research on bio-machines and their material efficiency.

The first scholar to present was R.J Reynolds distinguished professor of chemistry, Dr. David N Beratan, Ph.D. His research concerns the transition from soft, wet, and tiny research machines to more durable, long-term research machines in the science field. “The machines of biology tend to be stochastic and floppy rather than deterministic and hard,” Beratan began. “They’re messy and there are lots of moving parts. They’re intrinsically noisy and error-prone, etc…They’re very different from the kinds of things you see under the hood of your car, and we’d really like to understand how they work and what lessons we might derive from them for our world.” His complex research and research group have aided in bridging the gap in knowledge regarding the transition of biological functional machines to synthetic ones.

Dr.Rubinstein presenting his research on materials at Duke’s Pratt School of Engineering in 2019.

The panel continued with Aleksandar S. Vesic Distinguished Professor in mechanical engineering, Dr. Michael Rubinstein, Ph.D. His research involves the development of self-healing materials across multiple spectrums. “What you want to think about is materials that can heal themselves,” he stated. “If there’s a crack or a failure in a material, we would like the material to heal itself without external perturbation involvement. So it could be done by the other diffusion of molecules across some physical approaches, or by a chemical approach where you have bonds that were broken to the form.” His research on this possibility has made strides in the scientific field, especially in a time of such ecological stress and demand for materials.

Dr. Segura talking with Dr. Brinson on her research involving self-healing materials.

The panel concluded with biomedical engineering professor Dr. Tatiana Segura, Ph.D. Segura talked about work they are doing at their lab regarding materials that can be used to heal the human body after damage or injury. She began by mentioning that “we are a materials lab and that’s what we’re interested in designing. So what are we inspired by? Well, we are really inspired by the ability of our body to heal.” At her lab, a primary motivation is healing disabilities after a stroke. “Sometimes you have something that you deal with for a long time no matter how your body healed. And that inspires us to consider how do we actually engage this process with materials to make it go better and actually make our body heal in a way that we can promote repair and regeneration.” Understanding this process is a complex one, she explained, but one that she believes is crucial in understanding the design of the material.

‘Materials for a Changing World’ was yet another extremely powerful speaker series offered this year during Duke Research Week. Our world is changing, and our materials need to keep up. With the help of these experts, material innovation has a bright future.

Written by Skylar Hughes
Class of 2025

Finding the Tipping Point for Coastal Wetlands

Cypress swamp, eastern North Carolina. Photo by Steve Anderson, Duke

DURHAM, N.C. — The Albemarle-Pamlico Peninsula covers more than 2,000 square miles on the North Carolina coastal plain, a vast expanse of forested swamps and tea-colored creeks. Many people would probably avoid this place, whose dense thickets of cane and shrubs and waterlogged soils can slow a hike to a crawl.

“It’s hard fieldwork,” says Duke researcher Steve Anderson. “It gets really dense and scratchy. That, plus the heat and humidity mixed with the smell of sulfur and the ticks and the poison ivy; it just kind of adds up.”

But to Anderson and colleagues from Duke and North Carolina State University, these bottomlands are more than impenetrable marsh and muck and mosquitoes. They’re also a barometer of change.

Researchers surveying plants in Alligator River National Wildlife Refuge in 2016. Photo by Mathew Stillwagon, North Carolina State University

Most of the area they study lies a mere two to three feet above sea level, which exposes it to surges of ocean water — 400 times saltier than freshwater — driven inland by storms and rising seas. The salt deposits left behind when these waters recede build up year after year, until eventually they become too much for some plants to cope with.

Trudging in hip waders through stunted shrubs and rotting tree stumps, Anderson snaps a picture with his phone of a carpet of partridge berry trailing along the forest floor. In some parts of the peninsula, he says, the soils are becoming so salty that plants like these can no longer reproduce or are dying off entirely.

Along the North Carolina coast, understory plants such as this partridge berry (left) are quickly ceding ground to species such as this bigleaf marsh-elder (right) as the soils become too salty for them to thrive. Credit: Steve Anderson

In a recent study the team, led by professors Justin Wright and Emily Bernhardt of Duke, and Marcelo Ardón of NC State, surveyed some 112 understory plants in the region, making note of where they were found and how abundant they were in relation to salt levels in the soil.

The researchers identified a ‘tipping point,’ around 265 parts per million sodium, where even tiny changes in salinity can set off disproportionately large changes in the plants that live there.

Above this critical threshold, the makeup of the marsh floor suddenly shifts, as plants such as wax myrtle, swamp bay and pennywort are taken over by rushes, reeds and other plants that can better tolerate salty soils.

Certain dwindling plants could be an early warning sign that salt is poisoning inland waters, researchers say. Credit: Steve Anderson

The hope is that monitoring indicator species like these could help researchers spot the early warning signs of salt stress, Anderson says.

This research was supported by grants from the National Science Foundation (DEB1713435, DEB 1713502, and Coastal SEES Collaborative Research Award Grant No. 1426802).

CITATION: “Salinity Thresholds for Understory Plants in Coastal Wetlands,” Anderson, S. M., E. A. Ury, P. J. Taillie, E. A. Ungberg, C. E. Moorman, B. Poulter, M. Ardón, E. S. Bernhardt, and J. P. Wright. Plant Ecology, Nov. 24, 2021. DOI: 10.1007/s11258-021-01209-2.

Salt is poisoning the soils past a point of no return for some marsh plants; one team is trying to pinpoint the early warning signs. By Steve Anderson.

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