Senate Structure and Operations Committee

Susan Witte is a social worker and Professor at the School of Social Work, where she teaches courses in the clinical and advanced generalist methods of the master’s program, as well as in the doctoral program. In 2019, Dr. Witte was selected as a member of the inaugural cohort of the Provost’s Senior Faculty Teaching Scholars in recognition of her outstanding achievements in both teaching and research. Dr. Witte’s research and teaching involve prevention and treating HIV/AIDS, other STIs, intimate and gender-based violence, alcohol and drug use, and related social determinants of health and mental health.

Sen. Simon Ogundare is an MD-PhD student at Columbia University’s Vagelos College of Physicians and Surgeons and a graduate of Columbia College (’24), where he studied neuroscience while participating in the John Jay and Laidlaw Scholars’ Programs. Born in New York and raised between Nigeria and the United Kingdom, he brings a transnational perspective to questions of health, identity, and structural inequality. 

Simon's research background explores the neuroscience of comorbidity, examining how chronic pain and depression co-occur, and how their neural representations become entangled in the brain. Elected to the University Senate in 2025, Simon is committed to transparency, structural accountability, and expanding student participation in university governance. His platform emphasizes cross-campus coalition-building and ensuring that the University Senate reflects the needs of students across CUIMC, especially during a time of active review of the University Senate’s structure and scope. 

Simon’s approach to advocacy is shaped by his international background, his work as a science communicator, and his commitment to building a community that welcomes and celebrates – rather than dilutes – diverse voices. He believes healing, education, and institutional change are fundamentally communal processes: each requiring trust, shared power, and sustained dialogue. On the University Senate, Simon aims to strengthen avenues of communication through existing and novel channels, strengthen the links between Morningside and CUIMC, and push Columbia toward a more inclusive, responsive, and transparent future. He sees the University Senate not just as a governance body, but as a platform for collective action: a space to organize across schools, challenge institutional inertia, and push for a Columbia that truly reflects the values, needs, and voices of its community.

Sen. Michelle Rivera-Lopez, a lifelong New Yorker, has been a dedicated member of the Columbia University community since 2006. Over the past two decades, Sen. Rivera-Lopez has accumulated deep institutional knowledge through a series of progressive leadership roles across the university's financial and academic sectors. Sen. Rivera-Lopez began her Columbia journey as an Accounting Manager in the Mailman School of Public Health's Finance Office. She later transitioned to the central Treasury Office, where she served as the Associate Director of Cash Management and Investments. Today, she has returned to Mailman to serve as the Department Administrator for the Department of Sociomedical Sciences (SMS). In this role, Sen. Rivera-Lopez is thrilled to partner with faculty, staff, and students alike, leveraging her diverse administrative expertise to ensure the university remains one of the absolute best places to work and learn.

Sen. Henry Ginsberg is the Irving Professor of Medicine at the Vagelos College of Physicians and Surgeons, where he has conducted basic and translational research on lipid metabolism and cardiovascular disease for 37 years. Dr. Ginsberg was Director of the Irving Center for Clinical Research from 1994 to 2006 and the Irving Institute for Clinical and Translational Research from 2006 to 2017. From 1992 to 2008 and from 2014 until the present, he has been PI on an NHLBI T32 postdoctoral training program in Arteriosclerosis Research. Dr. Ginsberg has published over 400 peer-reviewed and invited papers in journals, and has received funding from the NIH for more than 40 years. He also sees patients with severe lipid disorders and teach. On the University Senate, he serves on the Commission on the Status of Women and on the Structure and Operations Committee, and hopes that his many years on the faculty allow him to offer insights and perspectives relevant to the issues facing the University.

Sen. Henning Schulzrinne is the Julian Clarence Levi Professor of Mathematical Methods and Computer Science and Professor of Electrical Engineering. On the University Senate, he serves on the Executive Committee and on the External Relations and Research Policy and Structure and Operations committees.

Professor Schulzrinne received his Ph.D. from the University of Massachusetts in Amherst, Massachusetts. He served as Chair of the Department of Computer Science from 2004 to 2009 and as Engineering Fellow, Technical Advisor, and Chief Technology Officer of the Federal Communications Commission (FCC) from 2010 until 2017.

Professor Schulzrinne has co-developed a number of protocol standards that are now used by almost all Internet telephony and multimedia applications, including RTP, RTSP and SIP. He is a Fellow of the Association for Computing Machinery (ACM) and the Institution of Electrical and Electronics Engineers (IEEE).

Sen. Gregory Mann, Professor of History, is an historian of West and francophone Africa. His work has focused largely on Mali and the Sahel in the twentieth century, including both the colonial and the postcolonial periods. Mann has written two books: From Empires to NGOs in the West African Sahel: the Road to Nongovernmentality (2015) and Native Sons: West African Veterans and France (2006). Each analyzes an aspect of governmentality, or the forms of governmental logic that animate life and struggle in the seam between state and society. Mann has also published a score of peer-reviewed articles—notably in the American Historical Review, Comparative Studies in Society and History, and the Journal of African History—on themes ranging from pilgrimage to migration, human rights, the history of the social sciences, and the historiography of Africa. He is currently writing a synthetic book-length essay on the historical relationship between Africa and France, from the mid-nineteenth to the twenty-first century.

Mann is a former editor of the Journal of African History, and a member of the editorial boards of that journal and of Humanity. He is a member—along with Dr. Devon Golaszewski, Madina Thiam and Oumou Sidibe—of the Projet Archives des Femmes du Mali, a project funded by the Modern Endangered Archives Program at UCLA. He is former director of Columbia’s M.A. program in History and Literature (Paris).

Mann has been a visiting professor at Paris-VIII (St. Denis), Sciences Po (Paris), and Paris-I Sorbonne-Panthéon. He has also co-organized a number of workshops and programs with colleagues at the University of Bamako. He has been a fellow of the Stanford Humanities Center and has won numerous other fellowships and awards.

Mann has worked with a number of doctoral students on dissertations in history, anthropology and political science, as well as with Master’s students in the Columbia-LSE Dual Degree Program in International and World History. Queries from prospective students are welcome.

Sen. Greg Freyer is Professor and Faculty Director of Graduate Education in the Department of Environmental Health Sciences at the Mailman School of Public Health.  He directs the DrPH and MS Toxicology programs and the Certificate in Toxicology. Dr. Freyer has been a member of the University Senate since 2011. He co-chairs the Faculty Affairs, Academic Freedom and Tenure Committee and serves on the Budget Committee, Structure and Operations Committee, the Commission on Benefits and the Commission on the Status of Health Sciences.

Dr. Freyer is deeply engaged in developing educational programs, teaches multiple courses and was recipient of both the Mailman School of Public Health Excellence in Teaching Award and the Columbia University Presidential Teaching Award in 2014. Dr. Freyer’s research has focused on cellular responses to environmental insults, particularly related to DNA damage. 

Sen. Daniel Wolf Savin is Senior Research Scientist in the Columbia Astrophysics Laboratory. Dr. Savin's work addresses cutting-edge questions in astrophysics, planetary science, and solar physics through observations coupled with laboratory astrophysics studies in atomic, molecular, condensed matter, and plasma physics. On the University Senate, he represents Professional Research Officers and chairs the Research Officers Committee. He serves on the Executive Committee, co-chairs the Structure and Operations Committee, and serves on the Budget Committee. Dr. Savin is a Fellow of the American Association for the Advancement of Science, the American Astronomical Society, and the American Physical Society. In 2026 Dr. Savin was awarded the Laboratory Astrophysics Prize of the Laboratory Astrophysics Division of the American Astronomical Society.

Sen. Brent Stockwell is the William R. Kenan Jr. Professor of Biological Sciences and Chair of the Department of Biological Sciences, Professor of Chemistry in Arts & Sciences, and Professor of Pathology and Cell Biology. He is a current Senator representing tenured natural sciences faculty in A&S, and a member of the Executive Committee of the Senate. He served on the Alumni Relations and Campus Planning and Physical Development Committees in the Senate. He has been on the Columbia faculty for 22 years, where he has consistently advocated for improved resources for science. In a series of papers from 2003 to 2012, Professor Stockwell discovered a previously unrecognized form of cell death that he termed ferroptosis. Professor Stockwell has received numerous awards, including being elected to the US National Academy of Medicine, the Lenfest Distinguished Columbia Faculty Award, the Great Teacher of Columbia College Award from the Society of Columbia Graduates, and the Dean Peter Awn Commitment to the LGBTQ community Faculty Award. He has been in the top 1 percent of highly cited researchers the last six years and was ranked among the top 50 scientists in the world by citations in 2025. He has published >200 scientific articles and received >50 research grants for >$40 million. He has served as Chair of the Educational Policy and Planning Committee in A&S, on the Columbia College and College of General Studies Joint Committee on Instruction, as Chair of the Provost's Advisory Committee on the Libraries Research Subcommittee, and as Chair of the Provost Faculty Advisory Committee. He has a BA in Chemistry and Economics from Cornell and a PhD in Chemistry from Harvard.

Brendan O’Flaherty is Professor of Economics. On the University Senate, he serves as parliamentarian, co-chairs the Senate Structure and Operations Committee and is a member of the Elections Commission.

Professor O'Flaherty's research focuses on homelessness, race, and the economics of cities. Before coming to Columbia in 1987, he spent two years as an aide to Kenneth Gibson, the first black mayor of Newark, N.J. He previously served as acting director of finance for the City of Newark and chaired the Program and Planning Committee of the Arts and Sciences at Columbia. He received his Ph.D. from Harvard. 

Sen. Andrew Puthumana is a student at Columbia College, majoring in financial economics with minors in sustainable development and history. He previously served as the pre-professional representative for the Columbia College Student Council, focusing on club reform and transparency regarding the student groups recruitment process. Andrew currently serves as the Financial Director of the Columbia Bartending Agency and as a Co-Executive Editor of Columbia’s Undergraduate Law Review, and remains active in other organizations related to research, student culture, and pre-professional development. 

As a University Senator, Andrew is interested in expanding dialogue around restoring student trust in the university administration and upholding shared governance–especially in Columbia’s current environment. With a dedication to work that impacts all Columbia students, he is passionate about ensuring student perspectives are recognized in university decision making and creating accountability for policy made outside of the University Senate.