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Summer Thesis Research Projects

Evaline Cheng '14


Salama from Madagascar! This summer, I am spending 8 weeks in the beautiful mountains of Ambohitantely Reserve, a central highland forest that is 140 km northwest of Antananarivo, the capital city. At this field site, I am researching the impact of biodiversity on the transmission of diseases from animal to human populations, focusing on plague and leptospirosis in small mammals in landscapes with various levels of human-use (large forest, forest fragments, villages, and rice paddies). Based on the dilution effect hypothesis, biodiversity may serve as a buffer for disease transmission, reducing the risk of zoonoses to humans. On a daily basis, this research involves hiking (often 10-15 miles a day) or bushwhacking in the forest to trap and bait small mammals with Sherman and Tomahawk traps and pit fall lines. Once captured, the animals are processed for blood, urine, and ectoparasite samples which will be used for disease analysis. Field work in a foreign country has been a challenging and exciting experience. At Ambohitantely, we are camping without electricity or showers, and our field lab is actually an open-air grass hut. Our typical meal consists of vary si laoka (rice with accompaniment, mostly beans) three times a day. Alongside the difficulties of communication, I’ve also faced unexpected challenges with research logistics and supplies (lack of transect tape means improvising with 100 meters of marked rope). On the other hand, it has been a reward to live alongside the local people: I have had the opportunity to interact with the Malagasy and learn more about their culture and language. Even with all the challenges I’ve encountered, Madagascar has embraced me with open arms. I could not be more thankful for such a unique learning experience and the funding that made this possible. Until next time, mandra pihaona!


Gilbert Tetteh '12
I performed an environmental genomic study on microbial biodiversity in South African gold mines for my independent lab-based senior thesis at Princeton University. My aim was to identify the biodiversity of methane-oxidizing methanotrophic bacteria and the general microbial community inhabiting the Beatrix Gold Mine from the initial collection of filtered water samples at the mine. After DNA was extracted from the samples, I targeted and amplified the pmoA genes (for the methanotroph) and 16S genes (for all microbes) via polymerase chain reaction (PCR), performed fluorescence-based gel electrophoresis to analyze the presence or absence of the DNA fragments and other co-extracted cellular components, ligated resulting DNA amplicons from the PCR into a pGEM-T Easy vectors and transformed them into competent E. coli cells for cloning. From the successful clones, DNA sequences were attained via Sanger sequencing and sequence analyses were completed via NCBI nucleotide database (BLAST), and 4peaks v1.7, Seaview v4.0, Se-Al v2.0 and MAFFT v6.0 computer programs. Through these programs, the sequences were aligned and Neighbor Joining phylogenetic trees that carefully organized the identified microorganisms from the Beatrix sample were constructed. 84 microbial species were identified from this study. Intriguing results were obtained from the research: A sulfate-reducing Firmicute called the Candidatus D. Audaxviator, previously unknown to possess methane-oxiding capabilities, was discovered in the methanotroph biodiversity analysis, which rouse the question “Did this organism attain methane-oxiding abilities from its neighbors via horizontal transfer to survive within its environment?” 

Erin, second from left.

Erin Buchholtz ’11
I had the opportunity to do my thesis research at Mpala Research Center, in the Laikipia District of central Kenya. The bushy savanna ecosystem there provided an excellent environment for studying wildlife, and after participating in the EEB department’s spring semester in Kenya, I knew I wanted to do my thesis work there.
   My thesis research is based on classifying the landscape-use and vegetation impact of wild herbivores. During the day, I measured the amount of photosynthetically active radiation (PAR) penetrating grass canopies to determine biomass. I also counted leaves on specific tagged tree branches. These numbers, collected on a regular basis, allow me to compare the amount of plant biomass over time and try to correlate it with animal activity. One of the most exciting parts of my project are the camera traps used to record this animal activity – I had 10 motion-sensing cameras set up within the field sites to capture images of animals! I loved going through the different images and seeing not only the herbivores I’m studying, like impala and zebras, I also have captured images of lions, elephants, wild dogs, and even a leopard.
   I thoroughly enjoyed doing my research at Mpala, and I’m very grateful for the opportunity. I appreciate the help from my professors, especially Lizzie King and Dan Rubenstein, plus the hard work of my field guide Koinange. I’m also thankful for the financial support and grants/thesis funding from the EEB Department, Dean’s Fund, and PEI.

Zakk Burns

Zackory Burns 10
I spent roughly 10 weeks over the summer in the Laikipia District of Kenya. I performed my research at the Mpala Research Center, a privately owned biodiversity conservation center of approximately 48,000 acres. Pastoralist communities belonging to the Masaai tribe surround the Mpala Research Center. I stayed at the Mpala Research Center with other undergraduate students, graduate students and my adviser, Professor Dan Rubenstein.
  My senior thesis analyzed plains zebras’ reactions to lion dung. I recorded over 250 zebra encounters and recorded about 100 characteristics per zebra. I used a program to help identify all zebras’ unique stripe pattern. I analyzed whether or not zebras reacted to lion dung, their anti-predation behavior, leadership dynamics and information exchange both within and between family groups, referred to as harems.
  My time spent in Kenya was one of the greatest experiences of my life. I would highly recommend the Mpala Research Center to perform your thesis. Mpala afforded me the ability to see such a beautiful location that includes elephants, lions, hyenas, grevys zebras and giraffes. Mpala definitely takes care of you, with great facilities, great food and a great research community.

Alexa Glencer 10
During the spring of my junior year, I was introduced to the concept of Health Impact Assessment (HIA). HIA is an interdisciplinary and multidisciplinary methodology designed to identify and analyze the potential public health effects of projects, programs, and policies. It is intended to influence decision-making by providing information that can be used to implement strategies that effectively minimize project-related negative health effects and that enhance project-related positive health effects. Over the summer, I interned at the Alaska Department of Health and Social Services Environmental Public Heath Program through a Princeton Global Health Program placement. While in Anchorage, I was granted unique exposure to the emerging field of HIA in the context of Alaskan natural resource development projects. I attended meetings held among federal and State regulatory and health agencies and tribal organizations, visited the Native Village of Tyonek during a participatory community outreach meeting, and collected baseline health data from a variety of State agencies. By the end of the internship, I was very familiar with the most contentious issues that impeded comprehensive analysis of project-related health effects within the HIA framework. Specifically, the rural Alaska Native villages predominantly affected by large-scale resource-extraction projects suffer from profound physical and psychosocial health insults related to diminished reliance on traditional subsistence lifestyles. Subsistence is integral not only to villagers’ diets but also to their social organization and traditional cultural practices.  Thus, project-imposed subsistence threats are particularly serious, and they warrant inclusion in the HIA process; however, it is often difficult to isolate project-related impacts from macro-level modernizing trends and to control for the mediating role of personal choice. Some of the greatest controversies encountered in current HIA negotiations are the product of project proponents’ adamance that limits be placed on the extent of their financial responsibility for determining baseline subsistence consumption figures and for enacting subsistence-related mitigation.
   This past January, I had the opportunity to return to Alaska, but this time, I was not destined for Anchorage.  Instead, I had arranged to speak with employees at the proposed Donlin Creek gold mine site about the local hire program that has provided them with a reliable source of income and, in doing so, has allowed them to adequately respond to the demands of a mixed subsistence/ cash-based economy. Anecdotal evidence already suggests that the program, which was implemented fourteen years ago, has significantly improved the wellbeing of the local population. Since it also serves the financial interests of Donlin Creek LLC, it represents a form of corporate social responsibility. I was particularly intrigued by the relationship that I perceived between corporate social responsibility and HIA. My exploration of this relationship, coupled to my understanding of the most cogent challenges emerging within the HIA field, allowed me to make predictions about future changes in HIA methodology. Specifically, I was able to suggest means by which complex socioeconomic and cultural repercussions of large-scale resource extraction projects may best be systematically recognized and mitigated. The purpose of my thesis is (1) to identify the need for Health Impact Assessment (HIA) as a standard component of the Alaskan resource extraction industry permitting process, (2) to describe HIA evolution to date within Alaska, (3) to identify persistent issues that impede formulation of a consistent HIA methodology within Alaska, and (4) to suggest strategies by which HIA could be best employed to resolve the tension between broad Alaskan public health concerns and corporate responsibility. 

Raaj Mehta
Photo: Raaj Mehta poses with Dr. Maritza Vaca and the subjects of the study in Tambillo, Ecuador.

Raaj Mehta ’10
I traveled to Esmeraldas, Ecuador and Santa Cruz, Bolivia to research the biology and policy surrounding intestinal parasites, like roundworm and whipworm. For the first five weeks, I was out in the field, canoeing to work every day, with a team of doctors from Quito. There, I collected and analyzed stool and blood samples from children living in tiny fishing villages on the coast of Ecuador to gather data for my thesis, on how these parasites suppress the immune system and prevent allergy. Then, for the next six weeks, I was in Bolivia, working with Save the Children on implementing a baseline nutritional study in the region, which includes work on determining parasite loads in children. Using data I collected, as well as information from interviews I conducted, I wrote an additional policy chapter for my thesis. I am extremely grateful to the Adel Mahmoud Global Health Scholars Program for funding my amazing travels.

Christina Jung ’10
Building upon the ideas from my JP on household treatment-seeking behavior in urban vs. rural malaria in Africa, I focused my thesis study on the circulation of counterfeit and substandard malaria medicines in the African informal drug market.  I spent a fascinating and eye-opening summer in Ghana, West Africa after my junior year interviewing families in Kokrobitey village about their knowledge of malarial symptoms and available medicines.  I found that patients strongly preferred informal or home-based treatment – primarily by purchasing drugs from the street market – over other care options, because of its accessibility and affordability despite the often questionable quality of market drugs and frequent treatment failure.  Interested in further investigating the informal drug market and the actual quality of malaria medicines available in drug shops, I returned briefly to Ghana in January of my senior year for two weeks.  This time, I collected samples of malaria medicines from various drug vendors in the markets that families and patients had mentioned in interviews previously, and talked with licensed and unlicensed drug vendors.  Ultimately, my study maintained that the informal drug market should be supported with education programs for drug vendors and patients because market medicine vendors sit at a crucial social intersection between patients and prompt treatment.  I had an amazing time traveling through Ghana and meeting families and drug vendors alike – thanks to the support of IIP, the Evnin ’62 Fund, and the Dean’s Fund.

Theresa Laverty

Theresa Laverty '10
I spent 9 weeks last summer in the Peruvian Amazon based in the Pacaya-Samiria National Reserve, one of the country’s largest protected areas, and on the border of Brazil in the Lago Preto Conservation Concession with Operation Wallacea. I based my work off a boat due to the remote study locations.
  My project compared the diets of three species of caiman, Amazonian crocodilians, using an adaptation of a stomach flushing technique. The population of the black caiman, the largest Neotropical predator reaching lengths of greater than six meters, was drastically reduced in the mid-twentieth century due to the value of its hide. Now protected, the species is once again expanding its range. The black caiman and spectacled caiman distribution and microhabitats greatly overlap. The diets of the two species also proved to be very similar. The spectacled caiman may be hindering the black caiman from reestablishing populations of the same magnitude of those noted a century beforehand.
  The Amazon was all I had ever hoped for and I loved getting into the heart of the rainforest. I chose a project that I could never imagine doing myself and am very grateful I was given this opportunity for field work. Aside from nights out surveying the crocodilians, I was able to enjoy the rest of the wildlife- macaws, monkeys, frogs, fish, etc- and fauna surrounding me.

David Gibbs '10
I am interested in both marine biology and epidemiology so I developed a thesis that combined these areas. I found this at a lab at the Virginia Institute of Marine Science that studies diseases of crustaceans. Over eight weeks during the summer, I studied several aspects of how a lethal species of parasitic ciliates infects blue crabs. I conducted four lab and aquarium-based experiments with crabs that I collected from local creeks. One experiment tested whether the ciliates need blue crabs to be wounded to enter them. (They do.) Another experiment tested whether the ciliates are attracted to blue crab hemolymph. (They are.) The other two experiments tested whether the ciliates can infect a species of fiddler crab (they can) and the minimum lethal dose of the ciliate in that fiddler crab. These experiments can help explain the natural transmission of this generally unstudied parasite. In addition to learning about crab diseases and the frustrations of research, I got a sense of what it's like to be part of a lab and how exciting it is to have multiple research programs in one lab.

Ruth Metzel '10
Los Santos, Panama is one of the most deforested and degraded provinces in Panama, the wealthiest nation in Central America. This confluence of characteristics makes it a likely place to experience a forest transition, the turnaround point at which a region begins to regrow forest after decades of deforestation. For my thesis I traveled down to Los Santos, Panama, to map forest cover change and explore the socioeconomic factors that lead a region to this forest transition point. I used satellite image analysis to determine that forest cover is increasing in Los Santos and a survey of 85 land managers in the area to determine the factors contributing to this regrowth. Due to the generosity of the Labouisse Prize, I plan to expand upon my thesis work and implement some of my recommendations for reforestation on the peninsula after graduation by working with the Azuero Earth Project, an NGO that will serve as the first permanent environmental resource available to landowners wis hing to reforest on the peninsula.

Heather Larkin '06
For my senior thesis, I was able (thanks to Professor Rubenstein and Ilya Fischhoff [graduate student]) to go Kenya with the purpose of studying leadership and decision-making in Plains Zebra. This involved going out every morning and/or evening to look for harems of zebra, taking 3-minute scan samples, and taking notes on individual and harem movement. Sometimes the zebra grazed nonstop for an hour, othertimes we saw the zebra do pretty amazing things: males fighting vehemently over a recently sexually matured female; females obstinately refusing to go where the male was pushing them (to the obvious frustration of the male); and a very rare event: a new born foal being fought over by the mother and another female of the same harem!
Photo: On the reserve there is a chimpanzee sanctuary for chimps who had been rescued from horrible owners all over Africa. This baby, along with two others were bring cared for by the owner of the sanctuary before entering the sanctuary.

Olympia Moy '05
I spent the summer at the Wolong Nature Reserve in Sichuan, China with the research team of Prof. Jianguo Liu of Michigan State University. Wolong is home to an estimated one tenth of the world’s giant panda population as well as the famous Hetaoping Panda Breeding Center. Less publicized is the fact that the reserve is also home to approximately 4,400 residents, mostly ethnic Qiang and Tibetan farmers. Human activity, particularly fuelwood collection for heat and cooking (of food and pig fodder) is the primary cause of panda habitat degradation. Recently, three different policies including a logging ban have been implemented that could have positive and negative effects on this situation. My study focused on the implementation of “Grain-to-Green,” a national reforestation policy that provides farmers with saplings and grain subsidies so that they will plant trees instead of crops. From May to August, we sampled reforested fields of 220 households by measuring saplings and collecting spatial data using GPS. It was a challenging but amazingly rewarding experience to live in rural China and collaborate with the local farmers and biologists. I’m eternally grateful to Prof. Liu and his team, Prof. Levin, and the Colvin Family for the opportunity.