AIM Executive Management

Shawn D. Lamb

Chairman of the Board

Shawn D. Lamb was the founding President of AIM from 1999 to 2015. As Chairman, Shawn continues to bring exceptional skills in nonprofit management, governance, board development, strategic planning, and membership to the AIM client base.

Shawn has been working with the toxicology industry since 1991, and served as the Executive Director for the Society of Toxicology for 21 years. In recognition of her outstanding leadership and international service to the science of toxicology, she was inducted as an SOT Honorary member in March 2015.

Shawn earned a BIS degree in business communications from George Mason University.  She is married to James Christian Lamb, IV and together they have five children, four children-in-law, and six grandchildren.

Deborah O’Keefe

President and Chief Executive Officer

Deborah O’Keefe oversees the Managing Partner team and leads all aspects of the management company, including increasing operational excellence on all levels, from strategy, to communications, marketing, technology, new business development, and financial management. She is charged with upholding the unique culture of AIM and its continuing work toward fulfilling its primary mission:  helping the scientific societies in its care to exceed their objectives.

As a founding Managing Partner, Deborah began her career as Director of Communications. She established and managed a team of creative and innovation specialists who developed and managed the professional image and branding of AIM and its client partners. With her guidance, the team continues to work to achieve growth for the organization through the utilization of emerging technology, insightful strategies, and innovative solutions that will enhance member engagement and increase operational efficiencies.

Deborah is a dedicated, life-long learner; she is currently pursuing a Master of Science in Leadership along with a graduate certificate in Nonprofit Management at Marymount University. She earned a BA from George Mason University and is a member of the American Society of Association Executives (ASAE). In her free time, Deborah enjoys being with her family and friends, supporting their passions and endeavors, traveling, and on occasion, skiing and sailing.


Clarissa L. Russell

Senior Vice President


Clarissa L. Russell brings more than 20 years of experience and expertise in association management to our partners and members. She is responsible for leading the teams who transition incoming partners—all of whom have successfully reduced their financial liabilities while experiencing growth in their net assets.

Clarissa is a founding Managing Partner of AIM. In 2017, she became the Executive Director for The Toxicology Forum. She has served over 19 associations in her career. She specializes in strategic and financial planning, as well as tradeshow and convention management with a focus on international participation. 

Clarissa earned a Masters of Business Administration with a concentration in finance from Johns Hopkins University. She earned her undergraduate degree from James Madison University. Since 1990, she has been a member of the American Society of Association Executives (ASAE) and in 1994, she received the Certified Meeting Planner designation. She also earned a culinary degree from the École hôtelière de Lausanne in conjunction with the University of Nevada, Las Vegas.


Veronica Fisher

Chief Financial Officer

Veronica Fisher has more than 25 years of experience in nonprofit financial management. As the director of finance and administration for AIM, she defines the process and implements the infrastructure and systems needed to support substantial growth. She continues to build and manage effective and streamlined administrative and financial systems, including financial, accounting, and legal matters.

Veronica is a founding Managing Partner and holds the senior finance management position for the Society of Toxicology. She specializes in ensuring that the audit communications, findings, and management comments are distributed to the Board of Governors without any significant findings.

Veronica is a member of the American Society of Association Executives (ASAE). Though she loves to spend time relaxing, here favorite pastimes are going to a movie, a play, or concert with her friends.


Tonia M. Masson

Chief Operations Officer

Tonia M. Masson has more than 20 years of experience in association management.  In addition to her operational role at AIM, she is also the Executive Director for the Society of Toxicology. She possesses excellent leadership, strategic planning, governance, program, publication, project, and financial management skills. In addition to those skills, she also provides the management company with expertise in IT management and new technology implementation techniques. 

Tonia has been with the management company since 1999 and is a founding Managing Partner. Active in other societies and forums, she has helped them to achieve notoriety and public awareness. She has been the past Executive Director for the Environmental Mutagenesis and Genomics Society, the Teratology Society, and the Toxicology Forum.

Tonia is a member of the American Society of Association Executives (ASAE). She is married and has two active children who she supports in their schoolwork as well as their pursuit of being better soccer, basketball, and softball players. Between sporting events, Tonia enjoys basking in the sunshine with a good book in hand.


Betty J. Eidemiller


Betty J. Eidemiller is a founding Managing Partner and serves as Executive Director and Director of Education for AIM clients. Since 1996, she has been working as an active member for many scientific societies, and has been a faculty member and academic division chair for several science education-related societies.

Betty has provided staff leadership for the Society of Toxicology’s education, awards, and membership programs. She has also procured grants and funding. She has led volunteer, strategic planning, and data management efforts. Betty has served as the Executive Director for the International Association of Environmental Mutagenesis and Genomic Societies from 2004–2015, and the Toxicology Education Foundation from 1998–2002. Previously she was Manager of Faculty Programs at the American Society for MicrobioRogy. 

Betty holds a PhD in Ecology and Evolutionary bioRogy from the University of California, Irvine and a BA from Whitman College.  She is a member of the American Society of Association Executives (ASAE).


Donna Breskin



Donna Breskin is a Managing Partner and Human Resources Director for AIM and serves as Executive Director of the International Union of Toxicology (IUTOX) since 2007.

Before AIM, Donna worked as an HR Director for small technology firms in the federal government contracting space. Prior to that, she worked in nonprofit organizations in a number of professional management and fundraising positions.

Donna has a Bachelor’s degree in Education and Special Education from SUNY at Geneseo, she also has a Master’s Degree in Human Resources Management from Marymount University in Arlington, Virginia. She is a member of the Society of Human Resource Management (SHRM) and the American Association of University Women (AAUW). She spends her free time cooking, entertaining and traveling, she especially loves exploring new cities, their art, and their cuisine. She’s married and enjoys spending time with, her immediate and extended family and friends.