Group: Faculty

Research Focus

The goal of my research centers on understanding how genetic, ecological, geographic and historical factors interact to generate, maintain and distribute biological diversity. Because these forces intertwine and operate on a continuum of spatio-temporal scales, my research ‚ which relies on diverse approaches (e.g., population genetics, phylogenetics), species distribution modeling, genome-scale data, ecological data, and powerful bioinformatics tools ‚ emphasizes an integrated approach to problem solving.

Current Projects

■ Gut microbiome of vertebrate species and their relationships with health and ecological niche of hosts

■ Ecological speciation of sparrows adapted to hot and dry environments

■ Landscape genetics of urban birds

■ Pathogens of pollinators in northern Virginia

■ Biogeographic histories, speciation, and population genetics of Southeast Asian birds

Select Publications

■ Lim, H. C., & Braun, M. J. (2016). High‐throughput SNP genotyping of historical and modern samples of five bird species via sequence capture of ultraconserved elements. Molecular Ecology Resources, 16(5), 1204-1223.

■ Lim, H. C., et al. (2017). Sundaland’s east–west rain forest population structure: variable manifestations in four polytypic bird species examined using RAD‐Seq and plumage analyses. Journal of Biogeography, 44(10), 2259-2271.

■ Lim, H. C., et al. (2015). Deep sequencing and ecological characterization of gut microbial communities of diverse bumble bee species. PLoS One, 10(3), e0118566.

Research Focus

My main interest as a writer is exploring the ways that people and places shape each other. My 2005 novel, Hear Him Roar, dramatizes human-mountain lion interactions to assess the environmental and social costs of suburban development in California. All of the stories in my award-winning 2010 collection, Right of Way, are set in one gentrifying urban neighborhood. I am currently collaborating with ethnobiologist Dr. Michael Gilmore on nonfiction narratives that explore the rich and complex relationship members of the Maijuna indigenous group in the Peruvian Amazon have with their ancestral rainforest landscape. This work studies and celebrates the deep linkages between biological and cultural diversity and underscores the importance of sustaining not only Earth’s biosphere, but also its ethnosphere.

Current Projects

■ The Reader of Currents: A Place-Based Biography of an Amazonian Indigenous Leader is a booklength biographical study of a 67-year-old leader of the Maijuna indigenous group in northeastern Peru. The life story of Sebastián Ríos Ochoa is considered in the context of Maijuna ethnohistory and the larger history of indigenous peoples in Amazonia since European contact. The project, a collaboration with Dr. Michael Gilmore, involves place-based ethnographic research as well as study of scholarly and archival materials.

Select Publications

■ Wingfield, A. and M.P. Gilmore. (2020). Three days of masato. ISLE: Interdisciplinary Studies in Literature and Environment 27(2), 406-415.

■ Bowler, M. T., B. M. Griffiths, M. P. Gilmore, A. Wingfield, and M. Recharte. (2018). Potentially infanticidal behavior in the Amazon river dolphin (Iniageoffrensis). Acta Ethologica 21(2), 141-145.

■ Wingfield, A. (2017). Back to Middle Earth. Carve Fall, 85-92.

Research Focus

I examine the use of communication to promote health and wellbeing, especially in response to serious health threats. I conduct multi-methodological, programmatic, field-based research employing a community-based participatory framework to examine health risks, develop evidence-based health promotion interventions, and implement/sustain refined health promotion programs, policies, technologies, and practices.

My work is designed to improve health outcomes for vulnerable and marginalized populations, including those who face serious socioeconomic, educational, cultural, and health challenges. I examine access to and use of relevant information for making informed health decisions. I develop evidence-based programs to reduce structural, economic, cultural, and bureaucratic barriers to well-being, as well as to prevent, prepare for, and respond to serious health risks and crises. My projects examine regional, national, and international efforts, including global health.

Current Projects

■ The Global Health Information National Trends Survey (HINTS) Research Program: expanding the HINTS-USA research program internationally to China, Germany, Japan, Switzerland, the Netherlands, Israel, Peru, and other countries to inform public health promotion efforts

■ Health Communication Delivery Training Program: working with faculty from the School of Nursing to develop and evaluate a training program for health care providers working with immigrant populations at the Mason and Partners Community Clinics

■ Communicating about Genetically Modified Foods: evaluating audience analysis research to guide design of public health education messaging programs about genetically modified foods

■ Partnership for a Healthier Fairfax: advising a public/private consortium to develop health promotion programs for at-risk populations

Select Publications

■ Kreps, G. L., et al. (2017). Expanding the NCI Health Information National Trends Survey from the United States to China and beyond: examining the influences of consumer health information needs and practices on local and global health. Journalism & Mass Communication Quarterly, 94(2), 515-525.

■ Kreps, G. L. (2017). Online information and communication systems to enhance health outcomes through communication convergence. Human Communication Research, 43(4), 518-530.

■ Kreps, G. L. (2017). Stigma and the reluctance to address mental health issues in minority communities. Journal of Family Strengths, 17(1), 3.

Research Focus

My research aims to develop and apply statistical methods for estimating the health effects of environmental hazards. Specifically, I am interested in estimating exposure to particulate matter (PM) air pollution, a complex chemical mixture of particles in the air. PM is known to impact health, and exposure to PM is associated with approximately seven million premature deaths worldwide each year. However, it is not currently known which PM mixtures are most harmful to human health. My work estimates PM mixtures using source apportionment models, which are dimension reduction approaches to estimate the sources that generate air pollution. These models can be used to estimate exposure to PM mixtures from sources, such as traffic, and their effects on health. The statistical methods that I develop and apply have applications outside of air pollution epidemiology, including the study of chemical mixtures in the body.

Current Projects

■ We have conducted a study of traffic-related particulate matter air pollution for women commuters in northern Virginia. This study is aimed at characterizing the relationship between commute behaviors and air pollution exposure.

■ We are developing statistical methods to adjust personal pollution exposure measured within commuting vehicles using ambient data to better understand the pollution sources that impact commuters. We are leveraging available data to improve source estimates within commuting vehicles.

■ We are developing statistical methods for summarizing air pollution sources across the U.S. Utilizing both standard and state-of-the-art approaches, we are estimating pollution sources across the U.S. and comparing source estimates.

Select Publications

■ Krall J. R., et al. (2017). A hierarchical modeling approach to estimate regional acute health effects of particulate matter sources. Statistics in Medicine, 36(9), 1461-1475.

■ Krall, J. R., et al., (2018). A multicity study of air pollution and cardiorespiratory emergency department visits: comparing approaches for combining estimates across cities. Environment International, 120, 312-320.

■ Krall, J. R., et al., (2016). Associations between source-specific fine particulate matter and emergency department visits for respiratory disease in four U.S. cities. Environmental Health Perspectives, 125(1), 97-103.

Research Focus

The major goal of my research program is to improve the environmental and economic management of living marine resources through the application of methods derived from economic and social science. My work is largely interdisciplinary and draws from disciplines as varied as marine biology, fish ecology, and natural resource economics. I have examined the environmental and economic performance of a number of fisheries in the U.S and Latin America (Atlantic sea scallops, salmon, shrimp). In addition, I have investigated the production and environmental economics of a broad range of aquaculture species (shrimp, tilapia, catfish, hybrid striped bass, scallops, seaweed) and culture systems around the world. My research has also attempted to measure the potential of aquaculture to improve the socio-economic conditions of coastal communities affected by declining fisheries in developing countries. The accomplishment of marine conservation objectives through the development of sustainable aquaculture industries is another long-standing research interest.

Current Projects

■ Ecological management of lionfish invasion in the Caribbean Sea.

■ Sustainable management of queen conch fisheries in the Caribbean Sea.

■ Development of Aquaculture Performance Indicators to assess sustainability of the global aquaculture industry.

■ Sustainable shellfish aquaculture enterprises as an economic alternative for artisanal fishing communities in the Wider Caribbean.

Select Publications

■ Valderrama, D., & Fields, K. H. (2016). Flawed evidence supporting the Metabolic Theory of Ecology may undermine goals of ecosystem-based fishery management: the case of invasive Indo-Pacific lionfish in the western Atlantic. ICES Journal of Marine Science, 74(5), 1256-1267.

■ Valderrama, D., et al. (2016). Economic assessment of hatchery production of Argopecten nucleus spat to support the development of scallop aquaculture in the wider Caribbean. Aquaculture Reports, 4, 169-177.

■ Valderrama, D., et al. (2015). The economics of Kappaphycus seaweed cultivation in developing countries: a comparative analysis of farming systems. Aquaculture Economics and Management, 19(2), 251-277.

Research Focus

I specialize in medical policies, particularly in the fields of organ transplantation and end-stage kidney and liver diseases. My research focuses on the applications of various quantitative tools such as biostatistics, Geographic Information Systems (GIS), simulation and mathematical optimization to analyze various medical and medical policy questions related to organ transplantation and other chronic disease treatments. My projects, funded by the NIH and NSF, include simulations and optimizations of organ allocation (NIH-R21) and bed allocation in a mental health system (NIH-R21 and R01), simulation of slum expansion in India (NSF), and network analysis of organ trafficking systems (NSF).

Current Projects

■ Network Analysis and Opportunities for Disruption of Organ Trafficking: this project performs a network analysis to understand the evolution of global kidney sales network and effective approaches to disrupt such networks.

■ Analysis of Optimal Geographic Boundaries and Organ Allocation Mechanism in Heart Transplantation: this project investigates the optimal boundaries for heart allocation to improve the equity in access to heart transplants in the United States.

■ Personalization of Immunosuppressive Treatment for Organ Transplant Recipients: this project explores new algorithms for personalized prescription of immunosuppressive drugs.

■ Optimal Desensitization to Support Kidney Paired Donation (KPD) System: this project explores the ways to argument the existing KPD exchange operation by effectively incorporating ABO and HLA antibody desensitizations prior to transplantation.

Select Publications

■ Brooks, J. T., et al. (2018). Improved retransplant outcomes: early evidence of the share35 impact. HPB, 20(7), 649-657.

■ Islam, M. S., et al. (2017). Towards a threshold climate for emergency lower respiratory hospital admissions. Environmental Research, 153, 41-47.

■ Koizumi, N., et al. (2015). Geographic variation in cold ischemia time: kidney versus liver transplantation in the United States, 2003 to 2011. Transplantation Direct, 1(7).

■ Patel, A., et al. (2012). Slumulation: an agent-based modeling approach to slum formations. Journal of Artificial Societies and Social Simulation, 15(4), 2.

Research Focus

My research interests broadly lie on intersections of interactive media, health communication, and strategic messaging. Research contexts primarily concern challenging health and environmental issues such as cancer, addiction, and climate change, as well as verbal and nonverbal interplay of doctor-patient communication. My interdisciplinary work allows me to employ both quantitative and qualitative methodologies.

Current Projects

■ A project that investigates public and government employees’ perception of climate change impacts on U.S. transportation manabgement and related policies

■ A project that examines humorous and active inoculating messages to counter misinformation about climate change

■ A project that investigates the effectiveness of the Every Try Counts anti-smoking campaign messages with eye tracking technology

■ A project that examines mobile text messaging strategies to encourage quitting among Korean and Chinese male immigrant smokers in the Washington DC metropolitan area

Select Publications

■ Kim, S. C., et al. (2019). Interactivity, presence, and targeted patient care: mapping e-Health intervention effects over time for cancer patients with depression. Health Communication, 34(2), 162-171.

■ Cooke, S. L., & Kim, S. C. (2019). Exploring the “evil twin of global warming”: public understanding of ocean acidification in the United States. Science Communication, 41(1), 66-89.

■ Kim, S. C., et al. (2018). Understanding public opinion change of HPV vaccination controversy: effects of exemplification and the mediating role of projection. Health Education, 118(5), 402-412.

Research Focus

My research focuses on human-environmental interactions during the Later Pleistocene (~125,000 – 10,000 years ago). My work is driven by a desire to understand the factors that account for the success and spread of our species relative to the Neanderthals and other archaic human groups. I approach this through the lens of zooarchaeology– the study of animal remains from archaeological sites. Not only do zooarchaeological data provide information about past environmental conditions, but they also speak directly to human subsistence choices and landscape use. I am engaged in research at a number of sites, including Sibudu (South Africa), Border Cave (South Africa), Mughr el-Hamamah (Jordan), and Sefunim (Israel). I am particularly interested in the ways in which early human groups adapted to climate change.

Current Projects

■ Reconstructing past subsistence and landscape use at Sefunim Cave (Israel) from ~60-20,000
years ago.

■ Exploring the relationships between climate change and human behavioral change in the
Middle Stone Age of Southern Africa.

Select Publications

■ Clark, J. L. (2019). The Still Bay and pre-Still Bay fauna from Sibudu Cave: taphonomic and taxonomic analysis of the macromammal remains from the Wadley excavations. Journal of Paleolithic Archaeology 2, 26-73.

■ Shimelmitz, R., et al. (2018). The Upper Paleolithic and Epipaleolithic of Sefunim Cave, Israel. Quaternary International 464,106-125.

Research Focus

My research is at the intersection of several topics which are of vital concern to today’s society including how climate change and epidemic disease affect the treatment of traditionally marginalized groups such as Jews or women, especially in the context of weak states. My research also deals with the effect trade networks have on economic development and its resilience to exogenous shocks.

Current Projects

■ Pandemics, Places, and Populations: evidence from the Black Death

■ Global supply shocks and market disruption: the Tambora volcanic eruption of 1815

■ Assimilation and cohesiveness in a hostile environment: theory and evidence from Jewish communities in Medieval Europe

■ The institutional foundations of religious freedom

Select Publications

■ Jedwab, R., et al. (2017). Negative shocks and mass persecutions: evidence from the black death. GMU Working Paper in Economics No. 17-12.

■ Anderson, R. W., et al. (2016). Jewish persecutions and weather shocks: 1100–1800. The Economic Journal, 127(602), 924-958.

■ Johnson, N. D., & Koyama, M. (2014). Taxes, lawyers, and the decline of witch trials in France. The Journal of Law and Economics, 57(1), 77-112.

■ Johnson, N. D., & Koyama, M. (2017). Jewish communities and city growth in preindustrial Europe. Journal of Development Economics, 127, 339-354.

Research Focus

I have two overlapping areas of specialization. One is technology, science, and innovation policy. I am interested in the sources and implications of discoveries and inventions of all sorts, past and present. The other area is governance, at the regional, national, and global levels. I want to understand the processes by which policy-makers decide what to do. The two areas come together as I seek to comprehend how states, markets, individuals, and social groups interact to produce decisions about important new technological capabilities.

Current Projects

■ I am studying the federal government’s efforts to stimulate low-carbon energy innovation, with a particular focus on energy storage.

■ I am studying how the US government manages energy technology demonstration projects.

■ I am participating in the public discourse about energy and climate policy and politics.

■ I am working with colleagues to build out a policy agenda for federal funding of RD&D for deep decarbonization.

Select Publications

■ Hart, D. Making beyond lithium a reality: fostering innovation in long-duration grid storage. Information Technology and Innovation Foundation, November 28, 2018.

■ Sivaram, V., et al. (2018). The need for continued innovation in solar, wind, and energy storage. Joule, 2(9), 1639-1642.

■ Hart, D. Beyond the technology pork barrel? An assessment of the Obama administration’s energy demonstration projects. Energy Policy, 119, 367-376.F (2018).

■ Hart, D., & Kearney, M. ARPA-E: versatile catalyst of US energy innovation. Information Technology and Innovation Foundation, November 2017.