Author Archives: Daniel Watkins

About Daniel Watkins

I'm a graduate student in atmospheric sciences studying Arctic climate. Along with being a host here at Inspiration Dissemination, I'm a Science Communication Fellow at the Oregon Museum for Science and Industry, a member of the OSU Student Chapter of the American Meteorological Society, and guitarist for the band Mons La Hire.

Libraries of possibilities: Algorithmic identification of possible fossil chronologies

Cedric Hagen, a doctoral candidate in the College of Earth, Ocean, and Atmospheric Sciences, spends a lot of time thinking about fossils. He’s not a paleontologist, though: don’t expect to find him digging up a Tyrannosaurus Rex. For one thing, dinosaurs lived much too recently–a measly 66 million years ago, in the case of the T. rex. Cedric’s work takes him much, much further back in time to the beginning of the Cambrian era, which began over 500 million years ago.

PhD candidate Cedric Hagen (photo by Hannah O’Leary)

While the Cambrian era is not the beginning of life on earth (for that, you’d need to go back a staggering 3.5 billion years) the Cambrian era is important because that is the time when many of the major forms of life appeared. This includes, for example, spongelike animals, burrowing worms, creatures with carbonate shells, reef-forming animals, and arthropods like the remarkably successful trilobites. The apparent rapid increase in the diversity of life at this time is termed the Cambrian explosion.

*Trilobite. Public domain image from Wikimedia Commons, accessed 5/17/2020. Ellipsocephalus Hoffi detail (Cambrian Trilobite) (Fig. 31) (b), from “The ancient life-history of the earth” (Page 85)*

As you may imagine, there are numerous challenges to studying life from so long ago. One of the major challenges is that there simply aren’t very many samples in existence. Part of the problem is that although the rocks at the ocean floor are old from a human standpoint, since oceanic crust is continually formed at mid-ocean ridges and destroyed at deep-sea trenches, there’s a hard limit on the age of fossils you can find at the sea floor. Oceanic crust is at most about 200 million years old throughout most of the world’s oceans. While there are a few places in the Mediterranean that date back around 340 million years, even that is a couple hundred million years too young. Only at isolated locations on the continents are there places where Cambrian carbonate rock formations exist. “You can think of these as reefs, really old reefs,” Hagen said.

Carbonate rocks outcropping in the southern Nopah Range, Death Valley, CA (photo by Cedric Hagen)

Before the advent of carbon isotope and radiometric dating, geologists had to base their ordering of the fossil record on relative positioning in layers of rock and fossil co-occurrence. Sedimentary rock forms as layers of material (strata) pile up over time. So, the more strata above a fossil, the further back in time the fossil formed. If you find multiple fossils in one area, this is a reliable way to place the fossils in chronological order—that is, of course, if those layers haven’t been jumbled up by earthquakes, landslides, or tectonic folding in the meantime. An additional help is that the events that lead to fossilization, such as a mudslide, frequently result in many organisms being fossilized together. If the same species is found at two sites, it is likely that the two sites represent the same era. This lets scientists pin approximate dates on the co-occurring fossils.

Radiometric dating allows precise measurement of age based on the decay of radioactive material. As radioactive material decays, atoms of one element are transformed into another. For example, uranium decays (through a convoluted process) into lead. Measuring the relative abundance of each element allows one to calculate the age of the sample. Since these rocks are made in part from the remnants of carbon-shelled organisms, they also record the amount of particular isotopes of carbon that were present at the time that the organism died. Since the relative abundance of carbon isotopes varies slowly through time, the pattern of carbon isotope concentrations in a sample of carbonate rock is like a record of the rock’s position in time.

“We’ve pulled together these records that have different chunks of time, and we’re trying to correlate them to a single high resolution record that we know the time of so we can know the order of the fossils, ” Hagen says. “What we’ve started to find is that the uncertainty in these measurements is quite large, larger than previously anticipated—there’s a lot of different places and times where things could have evolved.”

Prior to this research, scientists lined up carbon isotope chronologies visually. Hagen has been working on numerical algorithm that allows a computer to identify possible matches between rock samples from different parts of the world. “We’re cataloging libraries of possibilities,” says Hagen. “Are there twenty [possible arrangements]? Are there two? What could we do as geologists to go into the field and pick one or two of those and narrow down this uncertainty?”

To hear more about Cedric’s research, tune in on Sunday,May 15^th at 7 PM on KBVR 88.7 FM. You can live stream the show, or, if you miss it, you can download this episode and most of our earlier shows as podcasts on iTunes.

Fitness for Life: Sport psychology and the motivations behind healthy lifestyles

For graduate teaching assistant Alex Szarabajko, being part of the team teaching the 3,000-plus students who take Lifetime Fitness for Health (HHS 231) every term is not just a job. “It’s the last time students are able to learn about physical activity, nutrition and mental health before adulthood, ” says Alex. The course, which tied for first place in a “Best of 2020” vote, lays a foundation for healthy habits by addressing physical activity, nutrition, and mental health. Alex started work on her doctorate in Kinesiology at Oregon State University in 2018 after completing master’s degrees in General Psychology and in Exercise and Sport Science at Eastern Kentucky University. As a researcher in the field of sport psychology, Alex works to understand the reasons that people pursue their fitness goals and engage in healthy behavior.

Alex first came to the United States to work as an au pair in Bethesda, Maryland. Her host family were very enthusiastic about college sports. In particular, Alex wanted to know: “Why are they so popular?” In her native Germany, university sports are not taken seriously. Instead, serious athletes are members of athletic clubs. If athletes are paid at all, it is typically only a small amount. With the exception of footballers, most elite German athletes need supplemental income, often from a career in a more traditional domain. (Link 2) Alex was excited by the idea of college athletes having national attention and earning scholarships through sport. Perhaps this was a way that she, too, could continue to compete, at least for a few more years. After returning to Germany and resuming track and field practice at her local club, Alex began applying for college in the United States. She was recruited by Eastern Kentucky University on a track and field scholarship.

Starting out, Alex thought she had her career path figured out. As a freshman at EKU she was required to go to a majors expo, which she reluctantly attended. At the expo Alex found a booth advertising the field of sport psychology, an experience she describes as an “immediate lightbulb.” She promptly changed her major to psychology to prepare for graduate work in sport psychology.

Following the completion of her bachelor’s degree, Alex stayed at EKU in order to do graduate work under the tutelage of Dr. Jonathan Gore. Psychologists use the term intrinsic motivation to describe actions inspired by internal rewards. For example, a person playing a sport just for fun is intrinsically motivated. Extrinsic motivation describes actions influenced by others. An employee performing a task that they personally don’t care about is extrinsically motivated. Working with Dr. Gore, Alex examined a third type of motivation, relational motivation, among athletes. Relational motivation is defined by the needs of a group. Initially, Alex expected to find that athletes in team sports like football and basketball were more relationally motivated than athletes in individual sports. To their surprise, she found little difference between sports. Instead, she found differences between the levels of relational motivation among female athletes and male athletes. She found that female athletes’ performance was significantly linked to relationships between athletes and coaches.

In 2018, Alex left Kentucky and came to Oregon. She arrived at the start of the academic year, never having been to Oregon before. It didn’t take long for her to feel at home. “I just fell in love with Oregon when I got here,” says Alex. “I was able to go to the coast, go to the waterfalls.” Being near to Eugene (Track Town, USA) is also a bonus: that’s where the 2020 Olympic trials for track and field are being held. Being raised by Polish parents in Germany, Alex speaks both languages fluently and holds citizenship in both countries. She’s volunteered as an official translator for the Polish national team in the past, and hopes to volunteer again for either the German or Polish team.

As a graduate student in Kinesiology with a Psychosocial emphasis, Alex is focusing now on health and fitness in adults, rather than only among adults who consider themselves athletes. About 10 years ago, her advisor, Dr. Bradley Cardinal, carried out a study examining required health classes in colleges and found that since 1930 the number of schools requiring a course in fitness and healthy living has dropped from 80% to 39%. Alex is interested in finding out whether this trend has continued since that study was carried out. Oregon State’s version of the class, Lifetime Fitness for Health, has adapted with time to address student needs. In particular, student responses to end-of-class surveys resulted in the addition of a mental health component the class, which initially only focused on physical activity and nutrition. Alex hopes to uncover more about how required health classes across multiple universities have adapted to changing needs of students, and whether the number of schools requiring such classes has continued to drop.

Tune in Sunday, February 2nd at 7pm on 88.7 FM or online to learn more about Alex’s research and her personal journey!

Swimming with Salmon(ids)

Dams, bears, and anglers aren’t the only challenges that salmon face as they undergo their journeys from their mountain river birthplaces to the Pacific Ocean and back again. Timber harvests, dam-induced streamflow changes, and climate change have increased stream temperatures throughout the Pacific Northwest. Native cold-water-loving species like salmon and trout struggle in warm water, while certain parasitic microbes flourish.

The confluence of the Deschutes and Columbia Rivers. Illustration by Daniel Watkins.

Sofiya Yusova, a master’s degree candidate in the Department of Microbiology at Oregon State University, researches the microbe Ceratonova shasta. Her work aims to understand how C. shasta adapts to climate change in river ecosystems in the Pacific Northwest. Her advisor, Dr. Jerri Bartholomew, runs a long-term monitoring project in the Klamath River, and recently began applying the same methods to the Deschutes and Willamette Rivers. Dr. Bartholomew and her lab identified the complex lifecycle of the parasite, recognizing that C. shasta requires an intermediate host (the polychaete worm) in order to infect fish. Understanding the lifecycle is critical for understanding how to intervene when fish populations are struggling, as well as for anticipating the effects of climate change. As stated on Dr. Bartholomew’s website, “Climate change is expected to have profound effects on host-pathogen interactions. We are examining how this might affect myxozoan disease by developing predictions for how the phenology of parasite life cycles will change under future climates, how changing flow dynamics will alter disease, and to identify river habitats that should be protected as refugia.”

Lifecycle of ceratanova shasta. Illustration by Daniel Watkins.

Having a healthy population of salmon is important for many groups, including tribal communities, commercial and recreational anglers. Salmonids (a family of fish including salmon, trout, whitefish, and char) are particularly susceptible to infection when water temperature is warmer than usual, stream flow is low, or the number of C. shasta spores is high. Collaborative monitoring projects on the Klamath River and the Deschutes River have shown that the danger of deadly infections varies along the course of the river. This knowledge has allowed river managers to focus their efforts. For example, if the number of infectious spores is especially high, dam flowthrough rates can be increased to “flush out” the pathogens.

Tune in Sunday, February 2nd at 7pm on 88.7 FM or online to learn more about Sofiya’s research and her personal journey.

You don’t look your age: pruning young forests to mimic old-growth forest

“I’m always looking at the age of the forest, looking for fish, assessing the light levels. Once you’ve studied it, you can’t ignore it.” Allison Swartz, a PhD student in the Forest Ecosystems and Society program in the College of Forestry at Oregon State, is in the midst of a multi-year study on forest stream ecosystems. “My work focuses on canopy structure—how the forest age and structure influences life in streams,” says Allison. “People are always shocked at how many organisms live in such a small section of stream. So much life in there, but you don’t realize it when you’re walking nearby on the trail.”

Three scientists holding large nets stand in a rocky forest stream. One wears a backpack with cable coming out of it. — No, that’s not a Ghostbuster backpack! Here, Allison is using an electrofishing device that stuns fish just long enough for them to be scooped up, measured, and released. From left to right: Allison Swartz, Cedar Mackaness, Alvaro Cortes. Photo credit: Dana Warren

Following a timber harvest, there is a big increase in the amount of light reaching the forest floor. The increase in light also results in an increase in stream temperatures. Fish such as salmon and trout, which prefer cold water, are very sensitive to temperature changes. Since these fish are commercially and recreationally important, Oregon’s water quality regulations include strict requirements for maintaining stream temperatures. As a result, buffer areas of uncut forest are left around streams during timber harvests. These buffer areas, like much of the forests in the Pacific Northwest, and in the United States in general, can be characterized as being in a state of regeneration. Dense, regenerating stands of trees from 20-90 years old, are sometimes called second-growth forest. These forests tend to let less light through than an old growth forest does. Allison’s work focuses on how life in streams responds to differences in forest growth stage.

A Pacific giant salamander – a top-level stream predator and common resident of Oregon’s forest streams. Photo credit Allison Swartz.

The definition of the term old-growth forest depends on which expert you ask, and there is even less agreement on the concept of second-growth forest. Nevertheless, broadly speaking an old-growth forest has a wide range of tree species, ages, and sizes, including both living and dead trees, and a complex canopy structure. Openings in the canopy from fallen trees allow a greater variety of plant species to be established, some of which can only take root under gaps in the canopy but which can persist after the gap in the canopy is filled with new trees. The tightly-packed canopy limits the amount of light that can reach the forest floor, including the surface of the streams that Allison studies.

Forest stream near Yellowbottom Recreation Area, Oregon. Credit: Daniel Watkins

Allison’s research project is focused on six streams in the MacKenzie river basin, which includes private land owned by the Weyerhaeuser company, parts of the Willamette National Forest, and federal land. At some of these sites, after an initial survey, gaps were cut into the forest canopy to mimic light availability in an old growth forest. Sites with cut canopies were paired with uncut areas along the same stream. The daily ebb-and-flow of aquatic species is monitored by measuring the oxygen content of the water. The aquatic and terrestrial ecosystems have mainly been studied separately, she explained, but the linkages between these systems are complex. Measurements of vertebrate species are carried out using electrofishing techniques. “We do vertebrate surveys which infludes a few species of fish and Pacific giant salamanders. We measure and weight them and then return them to the stream,” Allison explained.

Measuring cutthroat trout. Photo credit Allison Swartz.

Over the last few years, Allison has spent three months of the summer living and working at one of her research sites, the HJ Andrews Experimental Forest. “We didn’t have much in terms of internet the first few years, so you connect with people and with the environment more,” Allison said.

Allison never expected to be in a college of forestry. Her background is in hydrology, and she spent some time working for the United States Geological Survey before beginning graduate work. She has enjoyed being part of a research area with such direct policy and management impacts. “We all use wood, all the time, for everything. So we can’t deny that we need this as a resource,” says Allison. “It’s great that we’re looking at ways to manage this the best we can—to make a balance for everybody.”

Allison’s Apple Podcast Link

Perceptions of trust

Imagine a final exam for a college course with hundreds of students. The proctor, a teacher’s assistant who has not interacted with any of the students before, is walking up and down the rows. She sees motion out of the corner of her eye. A small piece of paper is on the floor, covered in tiny print–answers to questions on the exam. She asks the student in the nearest desk, if the paper is his. Should the proctor believe him?

Most of the decisions we make in day-to-day life are unconscious. We don’t make up lists of pros and cons and consult experts when we have to decide what shoe should I tie first, what foot should enter my car first, or whether to I turn on the blinker 5 seconds or 10 seconds before turning. Having to weigh the pros and cons and carefully consider the consequences of every action would be exhausting, and could even be dangerous.

Zoe Alley, PhD Candidate in Psychology at Oregon State

Deciding whether to trust a stranger, however, is not at all inconsequential. Our brains unconsciously process faces to make decisions such as whether a person is, for example, aggressive, or whether they should be trusted. Zoe Alley, a PhD candidate in Psychology at Oregon State, has spent the last three years studying how facial trustworthiness impacts adolescents and new adults.

“People around the world, from many different cultures, from many different ethnicities, tend to hone in on the same facial characteristics when deciding who they want to trust,” Zoe said. Within the first few seconds of seeing a person’s face for the first time, your brain makes judgments of that person’s aggressiveness and trustworthiness (among other traits.) These snap judgements are often inaccurate, but have appeared consistently enough in participants in psychological studies that it is thought by some to be an evolved trait. Nineteenth and early twentieth century scientists went so far as to provide expert witness at trials, describing “typical” features of criminals. Although this view is no longer considered scientific, the human tendency to attempt to draw conclusions from appearances has been measured, with often concerning results.

As Zoe explains it, it is not clear that we have control over how our brain processes faces. And conscious attempts to address these biases can lead to over-correction, which is also undesirable.

Zoe speaking at GradX 2019 at Oregon State University. The faces shown are the Oosterhof-Todorov faces: computer-generated representations of a trustworthy and an untrustworthy face.

However, knowing how the human mind makes judgments is important. “It can help us make decisions about the structure of our society,” says Zoe. She points out some troubling findings looking at the justice system and elections. A 2004 study found that among a random sample of prison inmates, after controlling for race, people with more “Afrocentric” features received harsher sentences. A study from 2007 showed people contenders for Senate and governor’s races in the US and asked them to choose the more competent candidate, making sure that participants didn’t recognize either candidate. The winner of the race was selected 72% and 68% percent of the time, respectively — a far greater success rate than expected by chance.

Zoe’s own work focuses on how people are affected by facial traits such as trustworthiness, aggressiveness, dominance, and exploitativeness. The data comes from a long running longitudinal study of about 200 boys in Oregon that started in the 1980s. Participants in the study were interviewed about once a year from adolescence into adulthood, with a special focus on understanding antisocial and deviant behaviors such as underage substance use and criminal behavior. Along with interviews, photographs of the participants were taken. However, these photographs had not yet been incorporated in any of the many studies based on the data set.

Processing the data was an enormous task. She analyzed facial structure development across 35 years of data for 200 participants. Each photo had to be considered individually, and to protect privacy she had to drive an hour to a secure facility to do the work. “I’m interested in seeing how facial characteristics develop across time, and how these characteristics alter people’s experience,” says Zoe. “Are people who look less trustworthy more likely to associate with deviant peers?”

Hear more about Zoe’s research findings and personal story this Sunday, June 9, 2019 at 7 pm on KBVR Corvallis 88.7FM. Stream the show live or catch the episode as a podcast in the coming weeks.

You can also watch Zoe’s GradX presentation here.

Repair, don’t replace: developing a new treatment for lower back pain

Chances are that you, or someone you know, has had lower back pain get in the way of daily life. For some people it is merely an inconvenience, but for many, it is debilitating. In the United States, over 70% of adults suffer from back pain at some time during their lives. Lower back pain is the second-most common reason for missed work, after the common cold. Lost productivity due to lower back pain is estimated to be over $30 billion dollars annually.

Out of the myriad causes of lower back pain, one of the most common is degeneration of the intervertebral disk. The intervertebral disk is like a shock absorber between bones in the spine. As people age, wear-and-tear on these disks leads to damage: essentially only children have intervertebral disks without any signs of deterioration. By middle age, lower back pain is sometimes bad enough that people resort to invasive surgeries.

Ward presenting his research at the Graduate Research Showcase, 2019.

Ward Shalash, a first-year PhD student studying bioengineering with Dr. Morgan Giers, is working to find a better way to treat deteriorated intervertebral disks. Currently, the primary method for treating severe back pain caused by a deteriorated intervertebral disk is to either replace the disk with an artificial disk, or to remove the disk and fuse the neighboring vertebra. Although these methods are effective in relieving pain, patients often need to have the procedure redone after ten years. In addition, particularly for the method where vertebra are fused, patients experience loss of flexibility. In 2003 a new method, cell replacement therapy, was demonstrated on a rabbit. This treatment involves collecting mesenchymal stem cells from a patient (generally from fat cells), and injecting them into the gel-like material in the center of the intervertebral disk. Ideally, this process allows the disk to be restored in place. While this treatment has been applied with some success to human patients, the procedure is not yet standardized or tested well enough for FDA approval in the US. In particular it isn’t yet clear how to determine the number of cells to inject for best results.

This is where Ward’s research comes in. “The goal is to develop a method so that doctors can know whether cell replacement therapy will work for patients or not,” said Ward. An intervertebral disk consists of three main parts: the nucleous puplosus, a jelly-like substance in the center; the anulus fibrosus, stiff, fibrous walls around the jelly center; and cartilage endplates above and below.

Cross-section of an intervertebral disk. As the disk deteriorates, the gel-like nucleus pulposus leaks into the fibers of the anulus fibrosus.

Cells require a supply of nutrients to survive; as there is no blood flow into the disk, cells inside rely on water seeping through the cartilage endplates. Dissolved in the water are nutrients such as glucose and oxygen which are vital for cell survival.

Ward uses a combination of MRI imaging and mathematical modeling to study the flow of water through the intervertebral disk. From this information, he hopes to find a method doctors can use to determine the number of stem cells to inject. Ward hopes that the ability to algorithmically predict the success of treatment this way would cut down the cost of clinical trials.

Ward’s parents at the commencement ceremony in 2018. As a first-generation college student Ward mentions that his family’s support was important for him to continue his education towards a PhD degree.

Ward first came to Oregon as an exchange student from Israel. After finishing an associate’s degree at Portland Community College, he came to Oregon State to study bioengineering. He has a dream of a world where people don’t have to worry about injuries. One of his concerns is making sure that progress in bioengineering is ethical. For example, says Ward, “How do you make sure that it’s accessible for all kinds of people?”

Along with his academic pursuits, Ward enjoys the outdoors, playing the oud, and volunteering. To hear more about Ward’s story and his science, tune in this Sunday at 7PM (PST). You can stream the show live online, or listen to the interview live on the air at 88.7 KBVR FM, Corvallis. If you miss the broadcast, you can also listen to the episode on our podcast soon after the broadcast.

In the background is Mt. Broken Top in the Deschutes Basin. Despite common belief that PhD degrees are scary and stressful, Ward believes that there is always time for adventures!

References:
Summary of stem cell treatment for back pain: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3347696/
Discussion of current strategies for treatment of lower back pain: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5651638/

Magnet blocks, connect the dots, and the world of modern mathematics

At the Mathematical Sciences Research Institute in Berkely, CA with the Klein quartic sculpture. Photo by Charles Camacho

Charles Camacho, a sixth-year PhD student in the Department of Mathematics at Oregon State University, spends a lot of time thinking about shapes. He describes his research as such: “I study the symmetries of abstract mathematical surfaces made from gluing triangles together.”

Charles explaining his thesis research at the Latinx in the Mathematical Sciences conference at UCLA. Photo by Farida Saleh from the Daily Bruin.

Charles works in a branch of mathematics called topology. Topologists think about shapes and surfaces. There’s a joke among mathematicians that a topologist is someone who can’t tell the difference between a coffee cup and a donut, and there’s some truth to that. It’s not that they can’t see a difference, but that they look past the difference to see the core similarity: both are solid objects punctured with a single hole. Topology as a formal area of mathematics is fairly recent (early 20th century). Topology’s roots go much further back, though, through the streets of Königsberg in the 1700s and to the geometry of the ancient Greeks.

Königsberg bridge problem
There’s a famous puzzle that originated in Königsberg, Prussia in the 1700s (Königsberg is now Kaliningrad, Russia). The puzzle didn’t originate among mathematicians—but my understanding is that it’s mainly mathematicians that think about the puzzle now. Back then, there were seven bridges crossing the river Preger.

The Bridges of Königsberg (illustration by Leonard Euler, 1736).

The puzzle is this: Is it possible to cross each one of the seven bridges exactly once? (Go on, try it!) In his description of the problem and its solution, Euler said “it neither required the determination of quantities, nor did calculation with quantities help towards its solution.” He was interested in solving this superficially trivial problem because he couldn’t see a way for algebra, counting, or geometry to solve it. This goes against most people’s conception of mathematics—can it really be a math problem if you don’t fill a chalkboard with calculations?

The fact that no one yet had found a way to cross all the bridges without a repeat did not prove that it could not be done. To do that, and thus solve the problem for good, Euler had the insight to try and reduce the problem to its core. Reframing the Königsberg Bridges problem (elements of image from Wikimedia Commons, composited graphic by Daniel Watkins)
Knowing the layout of the city and all of its streets is irrelevant, so we can simplify to a map of just bridges. But even knowing that there is a river and land doesn’t really matter. All we really need is to know is represented in the network on the right (what mathematicians today call a graph). Euler’s solution was this: “If there are more than two regions with an odd number of bridges leading into them, then it can safely be stated that there is no such crossing.” It didn’t matter where the bridges were, it just mattered how many of the possible paths led to each landmass.

With collaborators at a summer research workshop on graph theory. Photo copyright American Mathematical Society

Being a mathematician, Euler wasn’t satisfied just stating a solution to the Königsberg problem. He went further, and generalized: he came up with rules and a solution that would work for any city with any number of bridges. All you have to do is look at the crossings, and note whether there’s an odd number of ways to get there, or an even number of ways. Euler’s method was developed by later mathematicians into graph theory, a branch of mathematics focusing on sets of points and the paths connecting them. Graph theory has a reputation for having many problems that are simple to state, but incredibly difficult to solve conclusively. In this sense, graph theory has a lot in common with geometric toy blocks.

Platonic solids
Charles has a set of magnetic toys in familiar shapes: triangles, squares, pentagons. These shapes are known as regular polygons, which just means that they are shapes composed of straight lines, each of which has the same length. Playing with these, one can hardly help but to arrange them into three-dimensional shapes. Playing with the triangles, you can quickly form a triangular pyramid: a tetrahedron. With six squares, a cube. With eight triangles, an octahedron. And with twelve pentagons, a dodecahedron. Surprisingly, there are only five shapes that can be made this way! Why is this the case? And must this always be the case?

The Platonic Solids: Tetrahedron, Cube, Octahedron, Dodecahedron, Icosahedron. Image copyright Daniel Watkins.

You might notice some other interesting things about these shapes. If you turn a cube while holding the middle of a side, you will see that it looks the same after each turn. It has rotational symmetry. Each of these shapes has multiple axis of symmetry. They can be rotated holding them in different ways and still show symmetry.

As a mathematician, Charles thinks about ways to generalize these ideas. We know that the five Platonic shapes are the only solids that can be formed from regular polygons, but what shapes could be formed if you used slightly different definitions? What if, for example, you used arcs of a circle to form the lines? What can we say about different kinds of surfaces? These shapes are defined on flat planes, like a piece of paper, but we know of lots of other surfaces, like the world we live on, that aren’t perfectly flat. What kind of symmetry do polygons in these geometries show? “Specifically, I wanted to know all the ways that such surfaces can be rotated a given number of times. I generalized previous research on counting symmetries and discovered a formula describing the number of these rotational symmetries,” Charles said.

A topological representation of a four-holed surface with a twelve-fold rotational symmetry (blue arrows indicate which edges are to be glued to make the surface. Graphic copyright Charles Camacho

Tune in to KBVR Corvallis 88.7 FM on Sunday March, 10 at 7 PM to hear more about Charles’s research, his inspirations, and his path to research in mathematics. Stream the show live or catch this episode as a podcast.

Feather collections and stressed-out owls

Ashlee Mikkelsen holding a juvenile northern spotted owl. Photo courtesy Ashlee Mikkelsen.

For six months out of every year, Ashlee Mikkelsen spends her days hiking for miles off-trail in the Ponderosa pine-filled forests of central Washington, hooting like an owl, and carefully listening for responses. These days, responses can be few and far between. You see, Ashlee isn’t just a wildlife enthusiast; she is a research assistant in a long-term US Forest Service monitoring program focused on the northern spotted owl.

Since being listed as threatened by the US Fish and Wildlife Service in 1990, populations of northern spotted owls have continued to decline. In some areas, the number of spotted owls has decreased by more than half in only 20 years (see (Dugger et al. (2016)). Northern spotted owls are inhabitants of old-growth forests. Although northern spotted owls historically could be found in almost every forest from northern California to British Columbia, as forests have shrunk in size through timber harvesting and through changing land use, the amount of suitable habitat has drastically decreased. A second major contributor to the decline of the northern spotted owl is arrival during the last century of the barred owl, which are native to northeastern North America. Barred owls competed with spotted owls for territory and resources, and have been observed fighting with spotted owls. Ashlee’s master’s research at Oregon State aims to quantify the stress experienced by spotted owls.

Northern spotted owl. Photo courtesy Ashlee Mikkelsen.

When birds experience stress, their bodies respond by releasing larger-than-usual quantities of the hormone corticosterone. Similar to cortisol in humans, corticosterone is always present, but having levels that are very high or that are very low is associated with poor health outcomes. It used to be that in order to measure the physical stress response of a bird, researchers had to take a blood sample. The problem with this is that the process of taking a blood sample itself is a source of stress for the bird. Recently, however, a new technique was introduced based on the fact that corticosterone is also present in feathers. Being able to use feathers is a distinct advantage: birds are constantly dropping feathers, so collecting feathers is fairly non-invasive, and importantly, similar to the benefits of measuring cortisol in hair, feather corticosterone measurements show the average level of the hormone over a long period, rather than just the instant that the feather is collected.

Ashlee banding a juvenile northern spotted owl. Photo courtesy Ashlee Mikkelsen

Working with professor Katie Dugger (who, incidentally, was Ashlee’s supervisor in the owl-monitoring field crew for the two years prior to beginning graduate school), Ashlee is analyzing a collection of feathers that spans over a 30-year time period. Measuring corticosterone levels in feathers is a high-tech process involving organic chemistry and radioactive isotopes. Although there are many complications that need to be accounted for, tracking the levels of corticosterone in these feathers gives Ashlee insight into the impact of stressors such as environmental degradation and competition with barred owls. Because the data spans so many years, she is able to examine the average stress in spotted owls over periods of change in the populations of barred owls. Ashlee’s data shows a strong response in corticosterone in spotted owls when the number of barred owls in the neighborhood goes up. This supports the view that spotted owls’ woes are not just due to habitat loss, but also due to competition with barred owls.

To hear more about Ashlee’s path to OSU, experiences in research, and of course about northern spotted owls, tune in Sunday, February 16th at 7 PM on KBVR 88.7 FM, live stream the show at http://www.orangemedianetwork.com/kbvr_fm/, or download our
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Applying medical anthropology: a history of stress in Puerto Rico and its impacts on birth outcomes

Over the course of the last six years, Holly Horan, a doctoral candidate in the Applied Anthropology program at Oregon State University, has developed and carried out a course of research culminating in the largest-ever study measuring perceived and biological maternal stress during and after pregnancy in Puerto Rico. By combining in-depth interviews with Puerto Rican mothers with quantitative analysis of perceived stress and the stress hormone cortisol during each stage of pregnancy, Holly has gained insights into both the perceived and the physiological components of maternal stress that have potential to impact birth outcomes (in particular, timing of birth).

Holly describes herself as an applied medical anthropologist. She strives to take a holistic approach to health, considering not only the physiology of an individual, but external factors as well: the political situation, economics, the culture, and the historical context of the research site. She is passionate about “community-led research.” In community-led research, the community where the research is being conducted takes a role in the development, execution, analysis, and evaluation of the research.

Holly has found a way to combine her personal and professional interests in maternal and infant health with her desire to engage in research with Puerto Rican communities. Holly’s mother is Puerto Rican, and she had long wanted to engage in research that could benefit the island. While completing a master’s degree in anthropology at the University of Montana, Holly did preliminary research on the early onset of puberty among Puerto Rican girls. Here at OSU, Holly has been able to use both qualitative and quantitative methods to research maternal and infant health within a community-led framework.

At the beginning of her dissertation research, Holly learned that the cesarean birth rate in Puerto Rico was close to 50% — far higher than the rate in the continental U.S., which hovers around 30%. Both rates are much higher than the rate recommended by the World Health Organization, which indicates that the cesarean birth rate should be no higher than 15%. She also learned that the island struggled with high incidence of preterm birth and low birth weight, both of which are important population-level health indicators. Holly’s advisor, Dr. Melissa Cheyney, is a home-birth midwife and an associate professor within the Applied Anthropology program in the School of Language, Culture, and Society. Dr. Cheyney helped connect Holly to Puerto Rican midwives, who, in turn, connected them to other medical providers in Puerto Rico.

In the summer of 2014, Holly conducted a pilot study, spending six weeks in Puerto Rico interviewing maternal and infant health-care professionals. These interviews allowed her to develop goals for her dissertation research that aligned with the needs of the community. Participant narratives frequently displayed concerns associated with unexplainable high rates of preterm birth.

Holly’s National Science Foundation (NSF)-funded dissertation research examined the relationship between perceived maternal stress, biological maternal stress, and prematurity. After the 2014 pilot study, she moved to Puerto Rico for 16 months, where she used semi-structured interviews and perceived stress questionnaires to develop an understanding of this relationship. In addition to this qualitative component, she also measured the stress hormone cortisol from maternal hair samples. Cortisol is one of the most well-understood biological stress indicators. Up until recently, the primary available way to measure cortisol levels was through blood or saliva samples, which provided only an indication of short-term stress. As it turns out, however, cortisol is also incorporated into hair. Hair cortisol provides a measure of long-term stress — the type of stress that is speculated to impact maternal and infant health outcomes, including preterm birth.

In the summer of 2016, Holly initiated her dissertation research with an extensive series of in-depth interviews with pregnant and recently-postpartum women. At this time, the ZIKA virus was declared a public health emergency, and there was a variety of public health messaging concerning delayed reproduction and the risk of microcephaly. Through these interviews, Holly learned that the U.S. Government’s public health messaging led to an internal conflict for many pregnant Puerto Rican women. Families felt stress and fear about the prospect of infants developing microcephaly. However, the warnings and official recommendations to delay reproduction provided uncomfortable reminders of the island’s colonial past, which includes targeted experimental clinical trials of oral contraceptives and sterilization offered primarily to low-income women. This led many interviewees to be skeptical about the threat of the Zika virus, but did not deter them from being concerned for their fetus’ well-being.

These participants identified sources of stress that varied widely, ranging from socioeconomic concerns, political changes, and gender-based inequalities. For example, in May 2016, Puerto Rico’s government defaulted on over 70 billion dollars of debt. Under the regulations passed by La Junta, the appointed fiscal board, many employees were fired and then rehired for lower pay. Also affected was the secondary public-school system: nearly 150 schools were closed. While these events are structural, the interviews revealed that within the Puerto Rican people, the impact of the events was personal, and the magnitude of impacts depended on individuals social support networks and life circumstances.

After comparing maternal cortisol levels with the perceived maternal stress from the structured surveys, which were collected in each trimester across pregnancy, Holly found a counter-intuitive result: some of the mothers who had most problems with their pregnancies (such as premature birth) had unusually low levels of cortisol. One current theory is the concepts of allostasis or allostatic load and “weathering,” a term which has been in the media in recently describing the cumulative effects of chronic stress on health (discussed in an NPR interview here in the context of race-based discrimination). Normally, the body responds to stress by heightening the amount of hormones such as cortisol. After the stressor is removed, hormone levels shift back to a low-stress state. However, if stress is prolonged over months or years–such as when living under a system of oppression–the body starts to experience “wear-and-tear,” causing the body’s stress response system to become ineffective. This ultimately impacts health outcomes, such as premature birth.

There have been road bumps along the way. In late summer 2017, Holly was nearly three quarters completed with data collection and the project was moving along smoothly. However, Mother Nature had different plans: In September 2017, Puerto Rico was hit first by Hurricane Irma and then by Category 4 Hurricane Maria two weeks later. The hurricanes destroyed the power grid and most of the island’s infrastructure. Holly was evacuated by OSU a week after the storm. Although she was worried about the well-being of her participants, and the impact this storm would have on the research project, NSF and her other funders graciously supported her to return and complete the study, which she did in February and March of 2018. As a separate side-project, Holly plans to return to Puerto Rico this summer to share study results with the community and with community partners.

To hear more about Holly’s research, tune in Sunday, December 9th at 7 PM on KBVR 88.7 FM, live stream the show at http://www.orangemedianetwork.com/kbvr_fm/, download our podcast on iTunes, or listen to this episode directly!