Yerby Fellows for the 2011-2012 Year
Josephine Asafu-Adjei
In studies that compare different diagnostic or treatment groups, subjects may not only be measured on a certain set of biomarkers, but also matched across groups on a number of demographic characteristics and measured on additional covariates. Josephine’s research focuses on modifying traditional discrimination and classification methods to also account for the group matching and measurement of covariates that may be used in a particular study, in order to more accurately identify discriminatory biomarkers. As a Yerby Fellow, Josephine is working with Dr. Rebecca Betensky in the Department of Biostatistics on novel ways to account for group matching and covariate effects on biomarker data in a variety of research areas, ranging from survival analysis to Bayesian variable selection techniques. A primary aim of her work is to explore the applicability of her research methodology to several types of studies typically involving group matching, including case-control studies and genetic/genomic studies.
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Cabral Bigman
Cabral’s research within the Viswanath lab and the Harvard School of Public Health’s Lung Cancer Disparities Center focuses on advancing understanding of how communication can be utilized to reduce health inequalities and promote public health, including cancer prevention efforts. Her past research includes studies related to framing, risk communication, and health communication. She is particularly interested in examining the effects of communication about health disparities.
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Patricia Chocano-Bedoya
Patricia’s research focuses on the interactions between dietary micronutrient intake and the synthesis of neurotransmitters in the brain. During her doctoral studies, she analyzed the role of dietary intakes of B vitamins and several minerals in the development of premenstrual syndrome (PMS) in the Nurses’ Health Study II PMS Sub-study. As a Yerby Postdoctoral Fellow in the Department of Nutrition, Patricia is working with Dr. Alberto Ascherio to study the role of micronutrient intake in the prevention of psychiatric and neurological diseases, particularly in depression and Parkinson’s disease, using data from the Nurses’ Health Study I and the Health Professionals Follow-Up Study cohorts.
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Dustin Duncan
Dustin’s research seeks to understand how neighborhood characteristics (such as the built environment, crime/violence, neighborhood disorder and collective efficacy) influence population health among children, adolescents and their families—with a special emphasis on minority health and health disparities. His research utilizes a geospatial lens to apply spatially explicit approaches such as computer-based geographic information systems, web-based geospatial technologies and geospatial modeling techniques. As a Yerby Postdoctoral Fellow, Dustin will primarily examine neighborhood determinants of youth cancer prevention behaviors (e.g. tobacco use and obesity risk behaviors) and disparities in neighborhood environmental features related to cancer risk (e.g. disparities in the tobacco retail environment). His primary research mentor is Dr. David Williams.
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Jonghan Kim
Jonghan's research interests center around metal toxicology and physiology-based pharmacokinetic and 
mechanism-based pharmacodynamic modeling. His current work focuses on the effects of iron status on metal transport and neurobehavioral disorders induced by olfactory manganese exposure in the context of genetic susceptibility using animal models of iron deficient anemia and iron overload hemochromatosis.
Variants of the HFE gene are the major cause of hereditary hemochromatosis (HH), promoting increased intestinal absorption and progressive tissue deposition of iron. HH has also been associated with abnormal accumulation of several toxic metals, most likely due to up-regulation of divalent metal transporter (DMT1) present in the intestinal and olfactory epithelium where it may play a role in metal absorption. However, whether or not HFE is a genetic determinant responsible for absorption of harmful metals has yet to be fully examined. To test the hypothesis that absorption of ingested and inhaled metals is up-regulated upon HFE-deficiency, he studies a mouse model deficient in HFE to examine DMT1 expression, pharmacokinetics of metal uptake, and neurotoxicity of metal exposure. His model suggests that these animals and individuals with HFE-associated hemochromatosis would be more susceptible to toxic metal exposure causing impaired neurobehavioral function.
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Miguel Marino
Miguel Marino’s research interests center around statistical issues for large scale community-based studies. There have been considerable technological advances in surveillance and community-based studies that have generated an explosion of data for which the number of covariates is considerably large. Miguel’s research focus lies in developing methodology that can address this unique setting. As a Yerby Fellow, he will work on the development of statistical methodologies tailored to large-scale HIV data from the developing world. The goal in many studies is to discover relevant variables among many potential candidates and achieve better interpretability and better predictive power for HIV outcomes. In the developing world, cost of measurement and rate of subjects who refuse to consent present unique roadblocks to variable selection. Miguel’s research objective is to identify methodological solutions to these roadblocks.
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Josiemer Mattei
Josiemer Mattei's research focuses on genetic, dietary and psychosocial determinants of chronic disease, as well as racial/ethnic variations in diet and genes that may explain health disparities across groups. As a Yerby Fellow, Josiemer is working with Drs. Frank Hu, Hannia Campos and Lu Qi in the Department of Nutrition on the effect of genetic variants and carbohydrate quantity and quality on risk of type 2 diabetes, weight changes, and related cardiometabolic outcomes across racial/ethnic groups, by conducting analysis on data from the Nurses’ Health Study, Health Professionals Follow-up Study, a population-based weight-loss intervention, and a case-control study in Costa Ricans. She continues to collaborate with the Boston Puerto Rican Health Study. In addition, Josiemer is helping develop a nutrition transition intervention for diabetes prevention in Costa Rica and Puerto Rico.
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Petra Sander
Petra Sander’s research focuses on understanding the role of behavioral risk factors in the acquisition of sexually transmitted infections within high-risk groups. As a Yerby Fellow, Petra is working with Dr. George Seage in the Department of Epidemiology on the Pediatric HIV/AIDS Cohort study, looking at sexually transmitted infection incidence in perintally HIV-exposed children as they pass through adolescence. Petra is also currently collaborating with Dr. Seage and Dr. Kenneth Freedberg at the Cost Effectiveness of Prevention AIDS Complications group on an agent-based modeling approach to estimate the potential impact of behavioral interventions on HIV incidence in South Africa. Outside of HSPH, she is part of a research team that studies how perceptions of partner concurrency, intimacy, sexually transmitted infection risk, and condom use change during adolescent relationships. Throughout her work, Petra is focused on applying rigorous epidemiologic methods to the analysis of longitudinal data.
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Weigou Zou
Osteoporosis is a major public health threat, afflicting over 200 million people worldwide. Osteoporosis is characterized by low bone mass, poor bone quality, and an increased risk of bone fractures. As a Yerby Postdoctoral Fellow, Weiguo Zou works with Dr. Laurie Glimcher on discovering novel signaling pathways in the skeletal system that regulate adult bone formation, with the goal of identifying new therapeutic targets to treat osteoporosis. Dr. Glimcher’s lab has recently shown that mice lacking Schnurri-3 (Shn3) have profoundly increased bone mass due to augmented osteoblast activity. Logically, compounds designed to block Shn3 related function are potential therapeutic agents for the treatment of osteoporosis. Weiguo’s research centers on the molecular mechanisms by which Shn3 regulates osteoblast function and bone density.
