Talia E. Abbott Chalew, PhD candidate, focuses her research on the effects of engineered nanoparticles in surface water on aquatic organisms, specifically Chesapeake Bay native oysters, Crassostrea virginica. She is also exploring the relationship between nanoparticle exposure and susceptibility to the oyster disease Dermo, Perkinsus marinus, which has decimated the native population.
Yayi (Stephanie) Guo, PhD candidate, is working to reduce the burden of contaminated waters on morbidity and mortality due to diarrheal and other diseases by investigating water treatment methods used to detect and eliminate pollutants from potable waters. She is especially interested in studying the efficacy of purification systems in removing contaminants from waters polluted by human waste and agricultural operations. The appropriate selection and use of such systems to treat source waters prior to ingestion can potentially alleviate much of the microbial, and potentially also the chemical load in the waters, thereby improving drinking water quality and reducing the risk of illnesses. Melissa Opryszko, PhD candidate, is studying the effectiveness of non-piped systems to deliver potable water to rural populations in less developed countries. She is currently evaluating the ability of community-based small water enterprises in southern Ghana to improve surface water to meet the World Health Organization’s microbiological drinking water guidelines. In addition to water quality, evaluation criteria include impacts on health outcomes, changes in household water and hygiene behaviors, sustainability and community perceptions of the small water enterprises. Autumn Downey, PhD, focused her research on waterborne transmission of the parasite Cryptosporidium parvum and foodborne Cryptosporidium infections vectored by oysters commercially harvested from the Chesapeake Bay. The research involved identification of Cryptosporidium species and genotypes, and revealing the sources of Bay contamination as related to surface runoff from agriculture, wastewater discharges and wildlife. Kristen Gibson, PhD, focused her research on developing methods to isolate bacteria, viruses and protozoa simultaneously from large volumes of water. Subsequent to isolation, she is evaluating microbial molecular detection techniques, including quantitative polymerase chain reaction and mass spectrometry, for the enumeration of isolated microbes. Cynthia McOliver, PhD, focused her research on C. parvum contamination of water reservoirs within the Baltimore metropolitan area, and characterization of environmental exposure to Cryptosporidium of HIV-infected population via urban fishing and other water-related activities. She also investigated transmission of Cryptosporidium via seafood (i.e., blue crabs) commercially harvested from the Chesapeake Bay.
Sharon Nappier, PhD, evaluated the public health impacts of non-native oyster species being considered for introduction into the Chesapeake Bay. She also worked to assess how implementing low technology irrigation systems in South Africa's KwaZulu-Natal province can improve the nutrition and health status of children in targeted communities. In addition, she has developed protocols to improve detection of noroviruses in peri-urban sites surrounding Lima, Peru. She is now a postdoctoral fellow at Drexel under Chuck Haas.
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