Learn about the SEP Staff

Sandra Arriaga, Academic Coordinator


Sandra (she/her/ella) joined SEP in 2022 after graduating from UC Berkeley with a B.A. in Molecular and Cell Biology and a Minor in Science and Math Education. During her time at UC Berkeley, Sandra held several roles, including volunteering as a Student Teacher in East Bay middle schools, and working as a Research Assistant in the Berkeley Psychophysiology Lab and for the Writing Data Stories Project

Rachel Harris, Academic Coordinator


Rachel Harris (she/they) joined SEP in 2022 after teaching both informal and formal science in public and private elementary schools in the East Bay for 16 years. She has an MA in Teaching and a Teaching Credential from University of San Francisco. She also participated in the Teacher Institute for Science and Sustainability program at the California Academy of Sciences.

Sabine Jeske, Academic Coordinator


Sabine (she/her/hers) joined SEP in 2006 with a dual background in science teaching and scientific research. She received her Masters degree in Biology from the University of Bonn, Germany and worked as a field biologist on environmental research studies. After moving to the Bay Area, she earned a teaching credential and worked as a science teacher at a public high school for several years.

Jennifer Chu Kaelin, Academic Coordinator


Before coming to SEP in 2006, Jennifer (she/her/hers) worked as a middle school math and science teacher and as coordinator for the Wild City! environmental education program at the California Academy of Sciences. Jennifer received a B.S. in Biology from the University of California at San Diego, a M.S. in Environmental Studies from San José State University and a teaching credential from Santa Clara University.

Mishael Aydela Marcelo, Program Assistant


Mishael (she/her/hers) joined SEP in 2022 with a background in healthcare administration and public health. She received her Bachelor’s degree in Health Education with a minor in Women’s Health Issues from San Francisco State University in 2020.

Luz Marin, Financial Manager


Luz started her UCSF career at the Library in 1987. While working at the Library and with both young daughters in school, she reduced her time at work in order to attend school full-time. In 1994, she moved to the Department of Psychiatry at SFGH, and provided financial and computer tech support to the Latino Mental Health Research Project. Prior to joining SEP, Luz worked for the Department of Medicine at SFGH, assisting the Budget Manager and Director of Finance with annual budget planning and implementation, and serving as a resource to the department with respect to faculty outside income, cash handling, accounts payable, purchasing, and UC financial systems.

Katherine Nielsen, Director


Katherine (she/her/hers) first came to SEP in 1995 as coordinator of Triad, a program set in SF middle schools focused on gender equity in science. She, returned to SEP in 2001, and became Co-Director in 2004. She has experience in both the education and scientific fields, having taught science at the middle and high school, community college, and undergraduate level; conducted research in developmental neurobiology; and completed a Masters Degree in Education from Stanford University and one in Biological Sciences from Montana State University.

Lizz Wang, Program Assistant


Lizz Wang (she/her/hers) joined SEP in 2022 with a background in early childhood education and medical biology/physiology. She received her Bachelor’s degree in Molecular and Cell Biology with a minor in Education from the University of California, Berkeley in 2022.


Lakisha Witzel, Academic Coordinator


Lakisha (she/her/hers) began working at SEP in 2008, with a background in biology and experience teaching in various informal science education settings. Lakisha received her M.S. from San Francisco State University where she investigated the impact that scientists working in partnership with elementary school teachers have on 4th and 5th grade students. As a graduate student, she participated in a year-long partnership with an SFUSD middle school science teacher.