AAAS Fellows - STeP



Step into our community and shape science for society! 




 Zack Valdez

Biography: Dr. Zack Valdez grew up in Dallas, TX and received Bachelor’s degrees in Engineering and Physics as a Div. II athlete (soccer), before earning a Ph.D. in Biogeochemistry. During this time, he conducted research on Liquid Nitrogen-powered Vehicles, modelling long-range transport of Mercury aerosols, and carbon cycling in biofuel agriculture. He has presented at conferences from Taiwan to Iceland. Zack has over 15 years of experience in educational outreach to promote diversity, equity, and inclusion in STEM. He currently works with the Society of Hispanic Professional Engineers to build k-12 and career services programming.





 Meagan Postema

Biography: Meagan is a second year AAAS Science & Technology Policy Fellow placed at the National Science Foundation (NSF), USA. She was born in Michigan and obtained her B.S. in Biomedical Sciences from Central Michigan University in 2012. Meagan went on to receive her Ph.D. from Vanderbilt University in 2019 in the Department of Cell and Developmental Biology where she studied the structure and function of the intestinal brush border. At the NSF, Meagan’s work is focused on global environmental change and sustainability with a portfolio spanning several international organizations. Her primary work is with the Belmont Forum Secretariat where she supports the operation of several funding calls.





Cristina Fernandez

Biography: Cristina Fernandez is an Environmental Engineer by training, broadly interested in water quality, agriculture, and energy issues. She received her B.S. and M.S. from the University of Iowa. Afterwards, she became an AmeriCorps member and worked with communities to implement energy efficient practices in homes and businesses and weatherized homes for elderly, disabled, and low-income families. At Cornell she studied microbial communities involved in greenhouse gas cycling, specifically focused on methane emissions from wastewater treatment. She was also involved in water quality research, quantifying fecal indicator bacteria in recreational waters and harmful algal blooms in the Finger Lakes. As a postdoctoral researcher at the USDA Agricultural Research Service, Cristina studied arsenic uptake in rice, from soil microbes to plant genetics, to reduce arsenic exposure from rice consumption.





Nikkia McDonald

Biography: Dr. McDonald is a materials scientist focused on energy conversion. Her work centres on fabrication and testing of hydrogen powered fuel cells and the characterization of cell microstructure-property relationships to elucidate performance behavior and long term reliability. Nikkia has conducted research in England, Turkey, and Ukraine, and collaborated with scientists in Czech Republic, Russia and Brazil in support of international science diplomacy initiatives. In her current role at DOE, Nikkia reviews program proposals for federal funding considerations, supports awardee project negotiation activities and applies materials science knowledge to highly complex energy technology projects to ensure technical milestones are met and project goals are achieved on time and within budget.



 Alice Grossman

Biography: Alice is currently a Science and Technology Policy Fellow (STPF) with the American Association for the Advancement of Science (AAAS) working at the National Oceanic and Atmospheric Administration to further the use of textual data for portfolio analysis and program planning, management, and evaluation. Within the AAAS STPF program she co-chairs the Developing Infrastructure Group. Prior to her Fellowship, Alice was a Senior Policy Analyst at the Eno Center for Transportation, an independent non-profit think tank in Washington DC. She has also taught graduate and undergraduate courses in Transportation Planning and Engineering at both the Georgia Institute of Technology and Southern Methodist University. Alice has worked with Pritzker award winning firm RCR Arquitectes, as well as with the South Pole Telescope Group at the University of Chicago. She completed her B.A. at Vassar College in Physics and Astronomy, and her Ph.D. at the Georgia Institute of Technology in Civil Engineering.