Science Spotlight: Senior Science Theses

The physicist Richard Feynman once wrote “we are very lucky to be living in an age in which we are still making discoveries… and that day will never come again. It is very exciting, it is marvelous, but this excitement will have to go.”

Although I’m skeptical that science will come to an end in the foreseeable future or even at all, the hypothetical is still interesting to contemplate. If there are only so many questions left to investigate then we should join in on the fun of discovery before it ends.

I had this thought in mind while I watched several of this year’s science thesis presentations and I couldn’t help but feel, along with awe and admiration, a tinge of envy. These students were already participating in the honorable task of furthering human knowledge and they were clearly enjoying it.

A thesis represents around a year’s worth of independent research. To pass their theses, students are required to give presentations to a general audience as well as defend their theses in front of a committee of three professors.

A senior thesis is optional for all science majors except for math majors. But theses are required in order to earn honors for chemistry, biochemistry, MBB, and biology.

“The percentage of students completing a thesis varies a lot year by year but I would guess between a quarter and a third of out students complete a thesis," Philip B. Stewart & Sarah F. Cowles Stewart  Professor of Chemistry Jeff Byers said about the thesis process. “Another third do some short term research over a J-term or semester.”

Recently fewer students have chosen to do theses. “The percentage of students completing thesis has plummeted because everyone wants to do double majors,” Byers explained. “When you do a double major you lose depth in both majors, which I consider a shame. I’m a big proponent of a major minor combination, even if the major is not in my discipline.”

Many students make the decision to do a thesis in their junior years and start work the summer before their senior year but the process is flexible.

Elaine Dellinger ’14 described how she got started on her thesis.

“I took an unusual route. I wasn’t planning on doing a thesis and I was just going to do summer research. I stayed here over the summer and worked with Molly-Costanza Robinson on her project. After the summer I thought I was done but in the fall we had some new ideas for different experiments so I decided to stay on and just do senior independent research and not a thesis. At the end of the semester I had to do a write up and I hadn’t realized how much data I had and how much I had to discuss. I ended up writing 40 pages for a short report and when I turned that in my advisor said I should just turn it into a thesis.”

Dellinger did her thesis on organically modified clays and water contaminant remediation. In her presentation she explained that organic contaminants such as BPA, steroids, pesticides, and antibiotics are prevalent in our water sources and that scientists are trying to find ways to remedy this.

“It turns out our drinking water treatment facilities are not that well suited for removing these types of organic contaminants.” Elaine explained. “An emerging method of water remediation for these types contaminants is the use of organically modified clays as absorbents to take in these contaminants from the water.”

She focused her research on one of the most promising types of clay called montmorillonite. Montmorillonite is composed of many small platelets stacked on top of each other and she looked at the interlayer space between them.

“The interlayer space is really important for the purpose of using this as a remediation technique because the interlayer space is where these contaminants would migrate into when they are absorbed from the water,” she said.

Dellinger specifically investigated how placing surfactant molecules in the interlayer space helps the clays absorb more organic contaminants. She found that when they increased the amount of surfactants in the clay the amount of inter-layer space increased but the crystallinity also increased, which would make it harder for contaminants to migrate into the clay. She proposed that to optimize absorbance they would have to create surfactant modified clay that maximized inter-layer space but minimized the crystallinity.

Brian Ayers ’14 also presented a thesis this year titled “The conjugation of anti-CD 47 antibodies to gold nanoparticles via click chemistry for cancer therapy.” In his presentation Ayers explained that anti-CD 47 antibodies were promising chemotherapy drugs because they were able to distinguish between healthy cells and cancer cells, unlike most current chemotherapy drugs, which have negative side effects.

Cancer cells normally avoid detection from the immune system because they display an extracelluar protein called CD 47.

“Researchers call this the ‘don’t eat my signal’,” Ayers said. “You can kind of think of it like a fake ID that it shows our immune system to pretend like it’s a normal cell.” The anti-CD 47 antibody blocks this ‘don’t eat me signal’ and enables the immune system to attack the cancer cells.
Ayer’s focused his research on finding a way to better deliver the anti-CD 47 antibodies to tumors. If antibodies are injected alone they don’t accumulate in tumors because have a ’leaky vasculature’ and antibodies flow right through them. But Ayers thinks that if he connects the anti-CD 47 antibodies to gold nanoparticles they will be more likely to accumulate in tumors.

“Gold nanoparticles are larger and as they travel through a tumor they will reach a pore that they can’t fit through. It’s like a roadblock. So they get stuck there and they start aggregating and that’s why they have this enhanced permeability and retention rate.”

During his year of research Ayer’s successfully connected anti-CD 47 antibodies to gold nanoparticles. In the future he plans to test them on cultures of cancer cells and on mice to see their effectiveness.

Dellinger and Ayer’s theses are just two examples of the brilliant work done by this year’s cohort of thesis students.  Ultimately, a short article is unable to do justice to these students and the best thing to do is ask about their research in person. Senior theses and undergraduate research are two of the most remarkable aspects of Middlebury and are well worth the time to investigate. They’re one of Byers’ favorite things about Middlebury.

“There’s no better way to get your money’s worth out of a Middlebury education than individual mentorship of a Middlebury college professor on a research project. In my mind, the major goal of a liberal arts education is to teach students how to think on their own and become life long learners. Nothing does that like generating truly new knowledge,” he said.