Monthly Archives: October 2019

Over sixty years digging and we’re still finding new ‘dirt’ on HJ Andrews

One kilometer. Or roughly ten football fields. That’s the extent of the area over which Karla Jarecke, a Ph.D. candidate in the College of Forestry’s Department of Forest, Ecosystems & Society can feasibly navigate her way through the trail-less HJ Andrews Experimental forest to collect the data she needs in a typical day of field work. Imagining a football field is perhaps not the best way to appreciate this feat, nor envision the complex topography that makes up this coniferous forest on the western flanks of the Cascade mountains, roughly 50 miles East of Eugene. But these characteristics are precisely what have made this forest valuable to scientists since 1948 and continue to make it the ideal place for Karla’s research.

Experimental watersheds like the HJ Andrews forest were established initially to understand how clear-cutting influenced forest drainage and other ecosystem processes such as regrowth of plants and change in nutrients in soils and streams. This was during the time when timber-take was increasing and we still had little understanding of its ecosystem effects. Karla’s work is also forward-thinking, but less on the lines of what will happen to drainage when trees are removed and more focused on understanding the availability of water for trees to use now and in the future. She wants to know what influence topography has on plant water availability in mountainous landscapes.

Meter deep soil pits at Karla’s field site.

Back to bushwhacking. The answer to Karla’s research question lies beneath the uneven forest floor. Specifically, in the soil. Soil is the stuff made up of weathered rock, decomposing organic material and lots of life but it is also the medium through which much of the water within a forest drainage moves. Across her study area, Karla has 54 sites where she collects data from sensors that measure soil moisture at two different depths. These steel rods send electrical currents into the ground, which depending on how quickly they travel can tell her how much water is present in the soil. She also keeps track of sensors that measure atmospheric conditions, like temperature and air humidity. This information builds on the incredible sixty-year data set that has been collected on soil moisture within HJ Andrews, but with a new perspective.

Digging soil pits on steep slopes occasionally required stacking logs at the base of a tarp to prevent the soil from sliding down the hill.
Photo credit: Lina DiGregorio

Karla explains that there have been long-standing assumptions surrounding elevation gradients and their control on water availability in a forest system. This understanding has led to modeling tools currently used to extrapolate soil moisture across a landscape. But so far, her data show huge variability on surprisingly small scales that cannot be explained by gradient alone. This indicates that there are other controls on the spatial availability of soil moisture in such mountainous terrain.

“We’re finding that model doesn’t work really well in places where soil properties are complicated and topography is variable. And that’s just the first part of my research.”

The next phase of Karla’s work seeks to evaluate tree stress in the forest and determine if there are any connections between this and the variability she is finding in soil moisture across spatial scales. True to the complex nature of the landscape, this work is complicated! But to Karla, it’s important. Growing up in the mid-west, Karla came to know water as “green” and when she moved West, first to fulfill an internship in Colorado and then to pursue her graduate work here in the Pacific Northwest, she was (and still is) amazed by the abundance of clean, clear rivers and streams. And it’s something she doesn’t ever want to take for granted.

Karla and her sister Stephani snowshoeing on Tumalo Mountain in the Cascade Range of central Oregon.

To find out more about Karla’s research and her journey from farming in Italy to studying soil, tune in on Sunday, October 27th at 7 PM on KBVR 88.7 FM, live stream the show at http://www.orangemedianetwork.com/kbvr_fm/, or download our podcast on iTunes.

Karla’s episode on Apple Podcasts

Monkeying around in the lab to find a good egg

In vitro fertilization (IVF) treatment is a procedure in which a woman’s mature eggs are removed via surgery, combined with sperm in a petri dish in a lab, and then the fertilized egg is placed in the uterus to continue growing into an embryo. Unfortunately, IVF is not covered by all insurance companies and is successful less than 50% of the time. Consequently, undergoing IVF can be a significant burden financially, physically, and emotionally for those who seek out this procedure.

What makes a “good” fertilizable egg? In this week’s special episode, we’re joined by Sweta Ravisankar, a 5th year PhD candidate in the Cell and Developmental Biology program at OHSU (Oregon Health & Science University), who is trying to answer this question in hopes that being able to screen for the “more likely to succeed” eggs, will lower the economic, financial, and physical hurtles of IVF.

Sweta works at the at Oregon National Primate Research Center, OHSU within the division of Reproductive and Developmental Sciences OHSU. She is a graduate student mentored jointly by Dr Shawn Chavez and Dr. Jon D. Hennebold.

The Hennebold lab studies reproduction before the egg is fertilized. This stage involves studying the female reproductive system, the oocyte (egg) itself, and the development of the follicle (region that holds the immature eggs) before ovulation (dropping of immature egg into the ovary). In contrast, the Chavez lab looks at what happens after fertilization such as chromosome abnormalities and how these abnormalities effect embryo development. This joint mentorship allows Sweta to study a more complete story of development.

Screenshot from a video of development from 1C stage to a blastocyst stage. Complex human being development can be traced back to these 120-150 cells implanting in the uterus.
Sweta is always excited to share her science!

Looking at reproduction from these two perspectives allows Sweta to correlate the environment the egg exists in with how the embryo develops. For example, what is the impact of a western style diet (high in fat) on the biochemistry and development of follicles and embryos long term? How does polycystic ovarian morphology (POM) mimicked by prolonged exposure to high fat diet and high testosterone levels in females impact reproductive success at the biomolecular level?

Will work when needed: in the lab on a weekend with a cast on my foot (visible on the left leg).

Being at the Oregon National Primate Center, Sweta’s model organism is the “Rhesus macaque” monkey. These monkeys have a genome ~97.5% similar to humans, meaning that the work she does is very relevant and translatable to humans. Working with the monkeys also means that her research is variable depending on the day. The monkeys will sometimes undergo treatments similar to those done in human IVF (in vitro fertilization) clinics, including surgeries to collect eggs for further research. After harvesting these eggs, they can be fertilized and the cells’ growth, division, and development can be monitored in a plate. When these experiments are not taking place, Sweta conducts various molecular biology experiments.

Sweta has become a true Pacific northwestener: hiking in rain with her husband through the Washington Park, Portland, OR. 

          

In India, Sweta completed her Bachelor’s degree at Dr. D. Y. Patil university in biotechnology and her first Master’s at SRM Institute of Science and Technology. During this time, Sweta happened to have several of family and friends undergoing IVF treatments and also worked in a fertility clinic for a time, bringing her attention to scientific needs within this field. Sweta then completed a second Master’s in Biological Sciences with a fellowship from the California Institute for Regenerative Medicine, and fell in love with fertility-related research during an internship at Stanford where she worked on embryo development. Her passion for this field of research led her to OHSU.

In addition to a being an accomplished researcher, Sweta is also an accomplished Indian Classical Dancer! She teaches bharatanatyam dance classes out of her home and travels around the US to perform. Long term, she hopes to continue research and also run a dance company.

Sweta will be presenting a piece on “depression” to work towards mental health awareness October 25th through 27th. The piece will be in Bharatanatyam and presented as a part of the 12th residency performance at N.E.W. 

Sweta writes her own blog posts about her journey through grad school which can be found here: 

  1. https://blogs.ohsu.edu/studentspeak/2017/09/11/it-is-possible-to-make-sad-not-even-seasonal/
  2. https://blogs.ohsu.edu/studentspeak/2018/07/24/phd-is-more-than-your-research/
  3. https://blogs.ohsu.edu/studentspeak/2019/04/18/never-give-up-there-is-a-bright-day-out-there-drudnischay/

To hear more about Sweta’s graduate work, personal struggles, and classical Indian dance moves, tune in on Sunday, October 20th at 7 PM on KBVR 88.7 FM, live stream the show at http://www.orangemedianetwork.com/kbvr_fm/, or download our podcast on iTunes!

Giving therapy-resistant cancer cells a taste of their own medicine

The use of chemotherapy to fight various forms of cancer in the human body has been a successful method for decades, but what happens when it fails? This question strikes a personal note for Martin Pearce, a Ph.D. candidate in the Department of Environmental and Molecular Toxicology at Oregon state University. Prior to his graduate work, both of his grandmothers were diagnosed with breast cancer. One successfully went through treatment and although the other initially responded well to chemotherapy, years later the cancer cells reappeared and there was no other treatment available.

Martin in the lab, running one of many Western Blots.

The academic system in the United Kingdom, from where Martin hails, encourages undergraduate students to take what is termed a “placement year” between their second and third years to gain practical experience. At the time of his grandmother’s returning prognosis, Martin was in the second year of his studies at University of the West of England Bristol which had a connection with East Carolina University in the States. Although deviating somewhat from his initial advanced level courses in business, the opportunity to work full time in a biomedical sciences lab at a university renowned for its medical research provided just the right place for Martin to spend the following year.

Martin’s time in North Carolina was not only practical but a reminder of his experience with biology in secondary school. His teacher was a doctor and she encouraged him to pursue a career in a biomedical field. While biology wasn’t his easiest subject, Martin was inspired by his mentor and enjoyed the challenge. Today, he is fully committed to this challenge as a key member in Dr. Siva Kolluri’s Cancer Biology lab group at Oregon State University researching new strategies to target the cancer cells that continue to grow after treatment with chemotherapeutic agents.

Current members of Dr. Siva Kolluri’s Cancer Biology Laboratory group.

Their work involves screening tens of thousands of compounds against such resistant cancer cells that express a particular group of proteins called the Bcl-2 family of proteins. The lab has discovered a novel compound that binds specifically to the Bcl-2 family of proteins that are consistently expressed in therapy-resistant cancer cells and cause them to change shape. One of the fundamental principles of cell and molecular biology is the relationship between structure and function. Change the structure of a molecule and its function within a cell can completely transform. In the case of the Bcl-2 family of proteins, this literally means life or death for the cell.

Protected within the typical expression of a Bcl-2 protein is a region Martin describes as a “death domain”; if this domain is exposed, it induces cell death. Cell death or ‘apoptosis’ is a naturally occurring process in biology. Without apoptosis in the early stages of human development, we would all have webbed fingers! Martin and his team have discovered a compound capable of binding to a Bcl-2 protein, causing it to unfold and expose its death domain. Thus, the protein transforms from one that protects the resistant cancer cell into one that kills it.  

Example of Breast cancer cells that are resistant to chemotherapeutic agent Taxol, that are responsive to compound Bcl-2 Functional Converter (BFC). Blue dots are cancer cell colonies.

Demonstrating the effectiveness of this pathway at the cellular level is remarkable, but Martin explains even the years it has taken to reach this stage are just the beginning of a very long process until it can be used to treat people with cancer. Beyond discovery, through the work of his Ph.D. Martin has realized other critical steps in developing effective cancer treatments that occur outside of the lab. For example, once a compound has been identified that successfully binds to a target protein, medical researchers must work with a patent attorney to protect their work and generate funding. Without patent protection, new drugs can’t be developed.

The dedication to ‘translational research’ or science that is specifically designed to be applied in improving health outcomes is what drew Martin to work with Dr. Kolluri in the first place and continues to inspire his plans for the future. Drawing back to his early interest in business, after finishing his Ph.D., Martin intends to explore a career as a patent attorney.

“This way I can be involved in the most exciting part of the process for me and be a part of people being at the edge of achieving what I was initially inspired in this career to achieve.“

Lifelong Bristol City F.C. supporters, Martin and his dad at Ashton Gate Stadium.

To hear more about Martin’s graduate work and insights into translational research, tune in on Sunday, October 13th at 7 PM on KBVR 88.7 FM, live stream the show at http://www.orangemedianetwork.com/kbvr_fm/, or download our podcast on iTunes!

What ties the Panama Canal, squeaky swing sets, and the Smithsonian together? Birds of course!

Have you ever wondered why you see birds in some places and not in others? Or why you see a certain species in one place and not in a different one? Birds have wings enabling them to fly so surely we should see them everywhere and anywhere because their destination options are technically limitless. However, this isn’t actually the case. Different bird species are in fact limited to where they can and/or want to go and so the question of why do we see certain birds in certain areas is a real research question that Jenna Curtis has been trying to get to the bottom of for her PhD research.

  • Jenna conducting field birding surveys on Barro Colorado Island (BCI)
  • Jenna next to one of their (absurdly heavy) autonomous recording devices

Jenna is a 4th year PhD candidate working with Dr. Doug Robinson in the Department of Fisheries & Wildlife. Jenna studies bird communities to figure out which species occur within those communities, and where and why they occur there. To dial in on these big ecological questions, Jenna focuses on tropical birds along the Panama Canal (PC). PC is a unique area to study because there is a large man-made feature (the canal) mandating what the rest of the landscape looks and behaves like. Additionally, it’s short, only about 50 miles long, however, it is bookended by two very large cities, Panama City (which has a population over 1 million people) and Colón. Despite the indisputable presence and impact of humans in this area, PC is still flanked by wide swaths of pristine rainforest that occur between these two large cities as well as many other types of habitat.

Barro Colorado Island can be seen in the centre of the Panama Canal.

A portion of Jenna’s PhD research focuses on the bird communities found on an island in the PC called Barro Colorado Island (BCI), which is the island smack-dab in the middle of the canal. To put Jenna’s research into context, we need to dive a little deeper into the history of the PC. When it was constructed by the USA (1904-1914), huge areas of land were flooded. In this process, some hills on the landscape did not become completely submerged and so areas that used to be hilltops became islands in the canal. BCI is one such island and it is the biggest one of them in the PC. In the 1920s, the Smithsonian acquired administrative rights for BCI from the US government and started to manage the island as a research station. This long-term management of the island is what makes BCI so unique to study as we have studies dating back to 1923 from the island but it has also been managed by the Smithsonian since 1946 so that significant development of infrastructure and urbanization never occurred here.

Large cargo vessels pass next to BCI on their transit of the Panama Canal

Now back to Jenna. Over time, researchers on the island noticed that fewer bird species were occurring on the island. There are now less species on the island than would be expected based on the amount of available habitat. Therefore, Jenna’s first thesis chapter looks at which bird species went extinct on BCI after the construction of PC and why these losses occurred. She found that small, ground-dwelling, insectivore species were the group to disappear first. Jenna determined that this group was lost because BCI has started to “dry out”, ecologically speaking, since the construction of PC. This is because after the PC was built, the rainforest on BCI was subjected to more exposure from the sun and wind, and over time BCI’s rainforest has no longer been able to retain as much moisture as it used to. Therefore, many of the bird species that like shady, cool, wet areas weren’t able to persist once the rainforest started becoming more dry and consequently disappeared from BCI.

Another chapter of Jenna’s thesis considers on a broader scale what drives bird communities to be how they are along the entire PC, and what Jenna found was that urbanization is the number one factor that affects the structure and occurrence of bird communities there. The thing that makes Jenna’s research and findings even more impactful is that we have very little information on what happens to bird communities in tropical climates under urbanization pressure. This phenomenon is well-studied in temperate climates, however a gap exists in the tropics, which Jenna’s work is aiming to fill (or at least a portion of it). In temperate cities, urban forests tend to look the same and accommodate the same bird communities. For example, urban forest A in Corvallis will have pigeons, house sparrows, and starlings, and this community of birds will also be found in urban forest B, C, D, etc. Interestingly, Jenna’s research revealed that this trend was not the case in Panama. She found that bird communities within forest patches that were surrounded by urban areas were significantly different to one another. She believes that this finding is driven by the habitat that each area may provide to the birds. 

Jenna has loved birds her entire life. To prove to you just how much she loves birds, on her bike ride to the pre-interview with us, she stopped on the road to smash walnuts for crows to eat. Surprisingly though, Jenna didn’t start to follow her passion for birds as a career until her senior year of her undergraduate degree. The realization occurred while she was in London to study abroad for her interior design program at George Washington University in D.C. where on every walk to school in the morning she would excitedly be pointing out European bird species to her friends and classmates, while they all excitedly talked about interior design. It was seeing this passion among her peers for interior design that made her realize that interior design wasn’t the passion she should be pursuing (in fact, she realized it wasn’t a passion at all), but that birds were the thing that excited her the most. After completely changing her degree track, picking up an honor’s thesis project in collaboration with the Smithsonian National Zoo on Kori bustard’s behavior, an internship at the Klamath Bird Observatory after graduating, Jenna started her Master’s degree here at OSU with her current PhD advisor, Doug Robinson in 2012. Now in her final term of her PhD, Jenna hopes to go into non-profit work, something at the intersection of bird research and conservation, and public relations and citizen science. But until then, Jenna will be sitting in her office (which houses a large collection of bird memorabilia including a few taxidermized birds) and working towards tying all her research together into a thesis.

To hear more about Jenna’s research, tune in on Sunday, October 6th at 7 PM on KBVR 88.7 FM, live stream the show at http://www.orangemedianetwork.com/kbvr_fm/, or download our podcast on iTunes!