Headshot of John Valentine smiling

Dr. John Valentine has served as the Head of the Office of National & Homeland Security at Lawrence Berkeley National Laboratory (Berkeley Lab) for 10 years. In this role, Dr. Valentine manages Berkeley Lab’s funded research for the national security agencies of the US government (e.g., DOE NNSA, DoD, DHS, and the intelligence community). Prior to joining Berkeley Lab in this role, he was Chief Scientist at Science Applications International Corp. (SAIC), Associate Program Leader for Radiological & Nuclear Threat Detection at Lawrence Livermore National Laboratory (LLNL), and a Nuclear & Radiological Engineering Program faculty member at the Georgia Institute of Technology and University of Cincinnati. Dr. Valentine received his Ph.D. and M.S.E. degrees from the University of Michigan and his B.S. from Texas A&M University, all in nuclear engineering.

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As the Program Manager for Nuclear Security Technologies (NST) at Berkeley Lab, I have over 17 years of experience in advancing the field of gamma-ray detection and imaging for various applications, including homeland security, space science, and nuclear nonproliferation. I have a Ph.D. in Nuclear Engineering from The University of New Mexico and multiple patents and publications in the areas of radiation imaging and simulations.

In my current role, I am standing up the NextGen nonproliferation leadership development program, a prestigious Postdoctoral fellowship (Darleane C. Hoffman Fellows) aimed at accelerating the next generation of nonproliferation leaders. Additionally, I cultivate and manage Berkeley Lab's portfolio of contributions to the DOE Defense Nuclear Nonproliferation Research & Development (DNN R&D) and the related Nonproliferation Stewardship Program (NSP), as well as other relevant agencies and stakeholders.

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Harshini has lived many professional lives. Originally from Chennai, India, and having completed college in Delhi (for the most part), she went to the U.S. for graduate studies, worked at a biotech startup for a couple of years, and then became a National Institutes of Health (NIH) postdoc at Los Alamos National Laboratory. In 2009, she was hired as a scientist at Los Alamos, where she remained for many years. In this role, she helped to grow their diagnostics portfolio on global health, pandemic preparedness, and national security, and then transitioned to serve as the Group Leader for Physical Chemistry and Applied Spectroscopy.

Berkeley Lab recruited her to join the Lab this summer with dual roles. Harshini will continue with her scientific endeavors with the Biosciences Area while also working in the Lab’s Office of National and Homeland Security (ONHS) to help the Lab explore and take advantage of rapidly expanding national security opportunities.

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I am Christine Mardell, the Administrator to the Office of National and Homeland Security. My career journey began with one of the Big Four Accounting Firms, where I thrived as an Executive Assistant in Advisory before advancing my career to Resource Manager in Tax. Throughout my tenure, I took pride in streamlining administrative processes and working closely with leadership to enhance efficiency and productivity. I had the privilege of serving as the Co-Chair for the DEI LGBTQ Pride Group for a decade where my leadership fostered a more inclusive and supportive environment, demonstrating my commitment to driving positive change.

Outside of work, you'll often find me at barre class, diving into a good book, volunteering, exploring new travel destinations, or spending quality time with my twin sister, family and friends.