Skip to main content

OCS Biographies


Dionne Toombs, Director for the Office of the Chief Scientist

Dr. Dionne Toombs is the Director for the Office of the Chief Scientist (OCS). In this role, she provides leadership on a wide range of issues affecting science programs and science policy in agricultural research, education, and economics. She comes to OCS from the National Institute of Food and Agriculture (NIFA) where she was Director of the Division of Nutrition, leading a collaboration of nutrition science leaders across the Department.  Under her leadership, the Division provided direction in science policy and program development to ensure the safety of America’s food supply and the availability of healthy food to its citizens.

She served as National Program Leader for NIFA’s Agriculture Food and Research Initiative (AFRI), leading large competitive grant programs to fund research into nutrition, food science and technology, and food safety.

Dr. Toombs received her Ph.D. in Nutritional Sciences from Howard University. She earned her Master of Science degree from Alabama A & M University and her Bachelor of Science degree in Biology from Bethune-Cookman University.

Richard Derksen, Deputy Director of the Office of the Chief Scientist

Richard (Rich) Derksen is the Deputy Director of the Office of the Chief Scientist (OCS). In this role, he provides direction and leadership on a wide range of issues affecting programs in agricultural research, education, and economics. Derksen manages review and product activity, tracks metrics, output, and impacts, and represents OCS on various Federal working groups and committees.

Derksen has over 25 years of direct research experience. He is an internationally recognized expert in crop production and protection engineering. At Cornell University, he held a joint research and extension appointment related to crop protection. In 1996, Derksen joined the Agricultural Research Service as a research scientist with a focus on providing engineering solutions to crop production and protection issues. He has authored over 200 publications, including 78 peer-reviewed journal manuscripts and given numerous invited presentations at national and international scientific meetings. Derksen received his Master of Science and Ph.D. degrees in Agricultural Engineering from the University of Illinois.

William C. Trenkle, Departmental Scientific Integrity Officer (DSIO) / Research Integrity Officer

Dr. William Trenkle joined the Office of the Chief Scientist in January 2018 as the Senior Advisor on Scientific Integrity and Departmental Scientific Integrity Officer for the U.S. Department of Agriculture (USDA). In this role, he will help to develop Department-wide policies on scientific integrity, administer USDA’s scientific integrity program, and provide oversight of responses to resolve scientific integrity concerns. He also serves as the principal advisor to the Under Secretary for Research, Education, and Economics on scientific integrity matters. 

Dr. Trenkle comes to OCS from the Division of Investigative Oversight (DIO), Office of Research Integrity (ORI), HHS, where he was the Acting Division Director for DIO and had previously served as the Acting Division Director the Division of Education and Integrity (DEI), ORI. Prior to ORI, he served as the Director of the Chemical Biology Core Facility in the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), NIH, as a Program Director with the Division of Pharmacology, Physiology and Biological Chemistry in the National Institute of General Medical Sciences (NIGMS), NIH, and was on the Chemistry faculty at Brown University. Dr. Trenkle has expertise in the forensic analysis of scientific imagery and was appointed to the NIST Organization for Scientific Area Committees (OSAC) for Forensic Science as an inaugural member and Vice-Chair of the Video/Imaging Technology and Analysis (VITAL) Subcommittee. The VITAL Subcommittee is working on the development of national standards and guidelines related to the forensic application of technologies and systems to capture, store, process, analyze, transmit, produce and archive images.

Dr. Trenkle was an NIH National Research Service Award (NRSA) postdoctoral fellow at Harvard University, received his Ph.D. from the University of California, Irvine and his Bachelor of Science degree from Alma College.

Advisors and Staff

Jaime Adams, Senior Advisor for International Affairs

Jaime Adams joined the Office of the Chief Scientist in 2011 as the Senior Advisor for International Affairs. In this capacity, Ms. Adams engages in cross-functional international agricultural science and technology collaboration with all levels of staff and leadership from government and non-governmental organizations. Ms. Adams' portfolio includes management of a multi-million dollar project and management and negotiation of numerous international bilateral and multilateral agricultural science and technology relationships. Ms. Adams manages the U.S. Government (USG) participation in the Global Open Data for Agriculture and Nutrition (GODAN) initiative. Ms. Adams has worked on international agricultural issues for over 10 years, having traveled extensively including serving in Afghanistan for over a year, and has supported high-level USG leadership including members of Congress, U.S. Ambassadors, and U.S. Cabinet officials. Ms. Adams earned a Master of Science degree in Agricultural Economics from the University of Illinois at Urbana-Champaign. Her Bachelor of Science degree in International, Resource, and Consumer Economics was also from the University of Illinois at Urbana-Champaign.

Neena Anandaraman, Veterinary Science Policy Advisor

Dr. Neena Anandaraman joined the Office of the Chief Scientist in 2014 as the Senior Advisor for Animal Health Production and Products. In this role, she coordinates scientific collaboration and planning on high priority emerging animal health agricultural issues. Her focus is on zoonotic infectious diseases - those that can be transmitted between humans and animals -- including antimicrobial resistance and biosecurity. Her work provides science-based advice to senior leadership to help inform their policy decisions.

Dr. Anandaraman served as Team Lead for the Prevention and Control Team in the Applied Epidemiology Staff in the Office of Public Health Science (OPHS) at the Food Safety and Inspection Service (FSIS). She is a veterinary epidemiologist and has been evaluating zoonoses issues for OPHS since 2001, focusing on foodborne conditions, especially Salmonella and antimicrobial resistance for their impacts on pre-harvest and post-harvest food safety. She served as a Supervisory Veterinary Medical Officer in the Office of Field Operations of FSIS in Arkansas before joining OPHS.

Prior to joining USDA, Dr. Anandaraman worked at a mixed animal veterinary practice in Texas. She received her Doctor of Veterinary Medicine from Texas A&M University, and her Master of Public Health from Tulane University. Dr. Anandaraman is a Diplomate of the American College of Veterinary Preventive Medicine.

David M. Babson, Ph.D., Senior Advisor for Renewable Energy, Natural Resources and the Environment on detail

Dr. David Babson is the Senior Advisor for Renewable Energy, Natural Resources and the Environment in the Office of the Chief Scientist at the United States Department of Agriculture. David is on detail from the Bioenergy Technologies Office (BETO) at the U.S. Department of Energy where he is Technology Manager. At BETO David oversees several projects for its Conversion Program and works to understand how to leverage new technologies to advance the emerging bioeconomy and address global energy and climate challenges. David is BETO’s federal lead for its waste-to-energy and advanced carbon commoditization efforts. Based in BETO’s Washington, DC office, David has extensive research and policy experience. Before joining BETO he advocated for sustainable transportation solutions as a Senior Fuels Engineer at the Union of Concerned Scientists, and served as an AAAS Science and Technology Policy Fellow in the Climate Economics and Modeling Center at the U.S. Environmental Protection Agency, where he reviewed key initiatives such as the Renewable Fuel Standard. Before starting his fellowship he completed post-docs at the University of Minnesota’s Biotechnology Institute and the U.S. Naval Research Laboratory. David received a PhD in Chemical and Biochemical Engineering from Rutgers University and a BS in Chemical Engineering from the University of Massachusetts Amherst.

Rena Bannister, Administrative Assistant

Ms. Rena Bannister joined the Office of the Chief Scientist in January 2015 as the primary Administrative Assistant. Ms. Bannister advises the Director and team of Senior Advisors of complex administrative processes and provides support in business greetings, executive correspondence, budget matters, procurement, personnel, data processing, travel, time keeping, program record-keeping, and report production. She is an expert on the policies and procedures for the development of issuances and other reports that are important across the Department. Ms. Bannister takes pride in serving as the first point of contact for callers to the Office, who may include Members of Congress, members of Congressional committee staff, White House officials, USDA executives and staff, high level executives from other Federal Departments and agencies, leaders of special interest groups, and members of the public. Ms. Bannister has received numerous awards for her administrative work since her first position in government service in 1984. She attended the University of Maryland University College from 1998-2004 and is currently pursuing a Bachelor of Science degree in Technical Management from Embry Riddle Aeronautical University. Ms. Bannister is passionate about working with others, creating a collegial atmosphere at work, and performing office operations at a high level.

Genevieve Croft, International Affairs Fellow

Dr. Genevieve Croft joined the Office of the Chief Scientist (OCS) in 2016 as International Affairs Fellow. She comes from the Association of Public and Land-grant Universities (APLU), where she served as the Senior Associate for Research Policy. In this role, she analyzed federal policies, developed positions, and represented APLU in stakeholder meetings with the White House, federal agencies, university membership, and external groups. She also coordinated the APLU Council on Research, comprised of the senior research officers of the Association's 235 member universities.

Prior to working for APLU, Dr. Croft worked on national and international science policy for the U.S. Agency for International Development, the White House Office of Science and Technology Policy, and the National Academy of Sciences. She has received both the American Association for the Advancement of Science (AAAS) Fellowship and the Mirzayan Science and Technology Policy Fellowship.

Dr. Croft earned her Ph.D. in Biology from Washington University in St. Louis. Supported by the National Science Foundation and the U.S. Department of Education, she conducted field and laboratory research throughout Latin America which led to a better understanding of the early processes of plant domestication. Dr. Croft holds a Bachelor of Science degree in Biology from Georgetown University and worked with farmers in Panama as a Peace Corps Volunteer, implementing sustainable agricultural practices.

Elizabeth Dann, Strategic Planning and Program Evaluation Officer

Ms. Elizabeth Dann joined the Office of the Chief Scientist in 2015 as Strategic Planning and Program Evaluation Officer. In this role, she oversees the Action Plan of the Research Education and Economics Mission Area (REE), monitors progress made with respect to science and research accomplishments and supports deep dive program evaluation, with Agency performance officers and an external advisory board. Ms. Dann comes from a leadership role with the USDA Food Safety and Inspection Service and previously the Office of the Director of National Intelligence, the Department of Defense, and from the private sector. Her strong interest in conflict analysis and resolution, change leadership, and financial and performance management have made her a trusted advisor to senior leaders seeking to create strategies and action-oriented solutions that align activities to organizational goals. Ms. Dann worked in a number roles and subject matter areas, including Senior Associate for cyber security for Booz Allen Hamilton, Vice President of sales and marketing for Discovery Communications, as well as serving as an Intelligence Officer for the U. S. Air Force. Her reputation for making the complex simple helps to inform decision-making by large organizations and small organizations alike. She focuses on the human side of issues and maps them to technical and operational activities to facilitate important changes. She is able to do so by developing critical partnerships for effective stakeholder engagement. Ms. Dann received her Bachelor degree from Harvard College. She has earned Certificates of Study in leadership, conflict analysis, and excellence in government from institutions including the Wharton School of Business, the U.S. Institute for Peace, the McDonough School of Business, and the Partnership for Public Service, where she is a senior fellow. She is currently working on the Lean Six Sigma Green Belt certification in data-driven process improvement.

Sarah Federman, AAAS Science and Technology Policy Fellow

Dr. Sarah Federman joined the Office of the Chief Scientist in 2017 as the AAAS Science and Technology Policy Fellow.  In this role, she works with USDA representatives to the National Science and Technology Council (NSTC) of the White House, coordinates Department activities related to plant health and production, and supports USDA’s role in the GEO Global Agricultural Monitoring program (GEOGLAM).

Dr. Federman has a strong interest in developing solutions to issues at the intersection of human development and the environment.  She designed and conducted original research in evolutionary biology, forged international multilateral collaborations, and managed field teams in Madagascar.  Her areas of technical expertise include: forest ecology and evolution, statistical coding, big data, geographic information systems, phylogenetics, and genomics.

With a passion for public service and inclusiveness in academia, she was involved in both Yale University’s Diversity Fellows Program and the Graduate and Professional Student Title IX Board. She actively engages in science outreach and education, working with diverse audiences through mentorship, publications, and presentations.  As a consultant for the Oak Spring Garden Foundation, Sarah developed educational materials for online courses on plant biology. She has consulted on combating illicit wildlife trafficking and managing the use of chemical pesticide. 

Dr. Federman received her Ph.D. from the Department of Ecology and Evolutionary Biology at Yale University.  Her research in the evolution of tropical biodiversity and the impact of extinctions on ecosystems over time was supported by a Graduate Research Fellowship of the National Science Foundation.

Sheila E. Fleischhacker, Senior Advisor for Nutrition and Food Safety

Dr. Sheila Fleischhacker joined the Office of the Chief Scientist (OCS) in February 2017 as the Senior Advisor for Nutrition and Food Safety.  She is on detail from the National Institutes of Health where she is the Senior Public Health and Science Policy Advisor in the National Institute of Diabetes and Digestive and Kidney Diseases Office of Nutrition Research.  Dr. Fleischhacker serves on strategic planning teams that identify vital research in nutrition.  As the lead author or contributor on a variety of peer-reviewed publications, her work has impacted legislation and policy at all levels of government on issues related to food and health.  Her work in land use and zoning requirements contributes to enhancing access to healthy food environments, fostering the ability for all to choose healthy eating options.  Dr. Fleischhacker received her Ph.D. in 2004 from The Pennsylvania State University and her J. D. from Loyola University Chicago in 2007.

Holly R. Wiggins, Strategic Planning and Program Evaluation Officer on detail

Ms. Holly Wiggins joined the Office of the Chief Scientist (OCS) on detail in October, 2017 as the Strategic Planning and Program Evaluation Officer while the incumbent Elizabeth Dann, is on detail in the Office of the Secretary. During her detail with OCS, Ms. Wiggins oversees the Action Plan of the Research Education and Economics Mission Area (REE), monitors progress made with respect to science and research accomplishments, and supports deep dive program evaluation with Agency performance officers and an external advisory board.

Ms. Wiggins is on detail from the Food Safety and Inspection Service (FSIS) where she has served over nine years in strategic planning, performance, and Federal budget formulation within the Office of the Chief Financial Officer. During her tenure at FSIS, Ms. Wiggins was recognized several times for introducing innovative solutions toward developing a cohesive strategic planning and performance framework including the development of the Agency’s first Strategic Planning Dashboard, the first annual FSIS Strategic Plan Performance Report, the first FSIS Annual Performance Planning Process Cycle, and the first Agency-wide employee engagement program, i-Impact Food Safety, which communicated the linkages between FSIS employees’ daily work to the larger Agency mission. This Agency-wide engagement program was the first of its kind at the USDA and was rolled out to the entire FSIS field and headquarter workforce of over 9,000 employees and is still in place, three years later. 

Prior to her Federal career, Ms. Wiggins has accumulated over 12 years’ experience working in a number of roles and industries relating to business, communications, strategy, and marketing in the private sector. She is skilled in the areas of leadership, change management, process improvement, product marketing, branding, and entrepreneurial initiatives and has run her own management consulting business servicing clients in the higher educational, publishing, consumer product, and non-profit sectors. 

Ms. Wiggins received her Masters of Business Administration (MBA) from Texas A&M University where she focused on globalization and international trade. She earned a Masters of International Policy and Practice (MIPP) from George Washington University’s Elliott School of International Affairs where her focus was on international law, intergovernmental organizations, and security. Ms. Wiggins has also completed graduate studies in human rights and international law at the University of Oxford emphasizing War, Peace and International Humanitarian Law (IHL). Ms. Wiggins volunteers her time as a Board Member for the non-profit organization, Thrive Saves Lives, (, which provides transitional housing and holistic resources for women and children survivors of domestic violence.

Paul Zankowski, Senior Advisor for Plant Health & Production and Plant Products

Dr. Paul Zankowski joins OCS on Oct 1, 2017, as incoming Sr. Advisor for PHPPP, bringing over 30 years of experience in plant sciences from basic to applied. He joins OCS on detail from USDA’s Agricultural Marketing Service/Plant Variety Protection Office (AMS/PVPO), where he has served as PVPO Commissioner since 2001. As PVPO Commissioner, Dr. Zankowski worked with public- and private-sector U.S. and international plant breeders to protect their new innovative varieties through the U.S. PVP system. He has collaborated with entities including the U.S. Patent and Trademark Office, the American Seed Trade Association (ASTA), Seed Association of the Americas (SAA), Association of University Technology Managers (AUTM), USDA ARS Office of Technology Transfer, Association of Official Seed Certifying Agencies (AOSCA ),and the International Union for the Protection of New Varieties of Plants (UPOV), as well as other country’s PVP offices, on plant breeder’s rights issues. Most recently, he has been actively involved in a joint working group comprised of scientists from ASTA and the PVP Advisory board, on developing an effective molecular marker protocol for distinguishing plant varieties, as a distinction basis that can be internationally accepted.

Prior to joining the USDA, Dr. Zankowski held the positions of  Director of Biotechnology, Vice President of Research, Biotechnology Manager, Associate Director of Science & Technology, and Cell Biologist, for Harris Moran Seed Company in San Juan Bautista, California, working on improving fruit and vegetable varieties since 1988.

Paul conducted post-doctoral research in plant biotechnology at Advanced Genetic Sciences (Oakland, CA) in 1987 and the ARCO Plant Cell Research Institute (Dublin, CA) in 1986, and received Ph.D. and M.S. degrees in Plant Physiology from the University of California, Davis and a B.S. in Biology from Penn State University.