Board of Directors for Exposition Park and the California Science Center

Diane Hamwi, Chair

Diane Hamwi is the Founder of DCH Advisors, Inc. a fundraising and public affairs consulting firm based in Southern California. Diane is a nationally recognized expert in politics, fundraising, project management, relationship building, and philanthropy. She has worked on over 45 presidential, senatorial, gubernatorial, municipal and initiative campaigns as well as with non-profit and advocacy organizations. A native of Los Angeles, Diane earned a Bachelor of Arts degree in Political Science from University of California, Santa Barbara and holds a Masters of Public Administration from The George Washington University in Washington, DC.

Jennifer Lin, Vice Chair

Ms. Lin has been a partner at Gonring, Spahn and Associates since 2006. She was director of corporate affairs at DreamWorks SKG from 1996 to 2006.




Janis Berman

Ms. Berman has been an advisor to Congressman Howard Berman since 1985. She was California co-chair of the Democratic Leadership Council from 1993 to 1995 and director of government relations in the LA Mayor’s Office from 1993 to 1994. She was a member of the Los Angeles Coliseum Commission from 1983 to 1985, president of the California Science Center Board of Directors from 1980 to 1985 and executive officer for Governor Edmund G. Brown Jr.’s Consumer Advisory Council from 1977 to 1979.


Jamie Callahan

Ms. Callahan has served as deputy cabinet secretary in the Office of Governor Gavin Newsom since 2019. She was director of external affairs in the Office of Governor Edmund G. Brown Jr. from 2015 to 2019, where she was special advisor to the executive secretary from 2013 to 2015. She was a campaign aide for Jerry Brown for Governor in 2010, legislative assistant at the Crane Group from 2007 to 2010 and a research assistant for the British Parliamentary Labour Party in 2006. Ms. Callahan is a member of the California K-12 High Speed Network Advisory Board. She earned a Master of Public Policy degree from the George Mason University School of Policy, Government, and International Affairs.

Billie Greer

Ms. Greer has been an independent consultant since 2015. She was president at the Southern California Leadership Council from 2011 to 2015 and senior staff member and director of Governor Arnold Schwarzenegger’s Los Angeles Office from 2004 to 2010. Ms. Greer was president and founding principal at Greer Dailey Inc. from 1993 to 2003, held several positions at Braun Ketchum from 1977 to 1993, including senior vice president of public affairs, and served as a teacher for the Long Beach Unified School District from 1959 to 1960.


Patricia Reon Roski

Ms. Roski has served as managing director at Majestic Realty Co. since 2007. She was of counsel at Glaser, Weil, et al from 1997 to 2007 and attorney in the Real Estate Transactional Department at Allen Matkins from 1994 to 1997. Roski earned a Juris Doctor degree from Loyola Law School.




Stanley Shuster

Mr. Shuster has been president at Grand Havana Enterprises Inc. since 1994. He was vice president of artist and repertoire at JRS Records from 1990 to 1994. Shuster is a member of the California Highway Patrol Citizens Advisory Board and the U.S. Air Force Thunderbirds.



Fabian Wesson

Ms. Wesson has been an assistant executive deputy at South Coast Air Quality Management District since 2016. She was a consultant to California State Senate President pro Tempore Kevin de León from 2015 to 2016, to California State Senate President pro Tempore Darrell Steinberg from 2009 to 2015 and to California State Assemblymember Mervyn Dymally from 2005 to 2009. Ms. Wesson was an administrative director at the First African Methodist Episcopal Church of Los Angeles from 1998 to 2004. She is a member of the Delta Sigma Theta Sorority Inc. Century City Alumnae Chapter Board, 10th Council District Women’s Steering Committee, Mothers In Action and the New Frontier Democratic Club.