Our Team

Marni Sommer, Professor of Sociomedical Sciences, Director of GATE 

Marni Sommer, DrPH, MSN, RN, has worked in global health and development on issues ranging from improving access to essential medicines to humanitarian relief in conflict settings. Dr. Sommer's particular areas of expertise include conducting participatory research with adolescents, understanding and promoting healthy transitions to adulthood, the intersection of public health and education, gender and sexual health, and the implementation and evaluation of adolescent-focused interventions. Dr. Sommer presently leads the Gender, Adolescent Transitions and Environment (GATE) Program, based in the Department of Sociomedical Sciences. GATE explores the intersections of gender, health, education and the environment for girls and boys transitioning into adulthood in low-income countries and in the United States. GATE also generates research and practical resources focused on improving the integration of menstrual hygiene management and gender-supportive sanitation solutions into global humanitarian response.

Natalie Wyss, Program Manager

Natalie Wyss, MA, is a Program Manager for the GATE Program. She has personal and professional interests in the intersections of health, education, and gender equity. Her research uses critical qualitative methods and has included studies on girls’ education, teacher practice, and early marriage. She has also supported studies on sexual and reproductive health, gender-based violence prevention, climate change education, and international education policy and decision making. Through this work she has collaborated with government, multilateral, and research partners from around the world including Latin America, East Africa, Eastern Europe, and South Asia. Natalie has a BA in Global Health from the University of California San Diego and an MA in Educational Policy Studies from the University of Wisconsin Madison. 

Susi Martinez, Program Coordinator

Susi Martinez, MPH, is the Program Coordinator for the GATE Program. She is interested in the intersections of gender and health, human rights, and health systems strengthening for migrant populations in low-resource settings, particularly among women, girls, and LGBTQI+ individuals. She has supported research on health system resiliency to natural disasters, investigated health systems' responses to gender-based violence in emergency settings, and contributed to monitoring and evaluation initiatives for HIV care. Susi previously worked at Comunidad Connect in Nicaragua, where she coordinated community development projects and managed a rural mental health program. Susi is passionate about implementing community-centered and sustainable health approaches using a gender and human rights lens. 

Angela Nguyen, Postdoctoral Research Scientist

Angela Nguyen, DrPH, MPH, is a postdoctoral research scientist for the GATE Program. She earned her doctorate from the University of California, Berkeley School of Public Health and her MPH from the New York University School of Global Public Health. Angela’s interdisciplinary research to date has focused on vulnerable populations, social determinants of health, and environmental exposures. Her dissertation centered on the epidemiology of disaster mental health, particularly the community- and individual-level factors associated with mental health recovery among displaced women survivors. More recently, she collaborated on a quantitative research study on the impacts of the COVID-19 pandemic on period poverty in the U.S. With GATE, Angela will engage on several research projects ranging from examining the dissemination of puberty educational content to young people, to assessing the impact of menstrual health on the daily lives of those with periods.

Sarah Blake, Senior Research Program Manager

Sarah Blake, PhD, MPH, MSc has worked at the intersections of research and programming in gender, adolescent health and well-being and rights across diverse global contexts, including West Africa and Central Asia. Her research focuses on qualitative and participatory research on the health and social dimensions of adolescents’ transitions to adulthood. Dr. Blake has contributed to policy and evidence reviews, and program evaluations of health and educational interventions in school and community settings. In addition, she has worked with community, national, and international non-governmental organizations to gather and translate evidence into adolescent-centered, community-based programming. Dr. Blake holds a PhD in Sociology from the University of California, San Francisco, an MPH in Population and Family Health from Columbia University, and an MSc in Gender, Development, and Globalisation from the London School of Economics and Political Science. 

Aminata Diarra, Research Assistant

Aminata is a second year MPH student in the Department of Population and Family Health with a certificate in Global Health. This past summer she completed her MPH Practicum abroad in Chad, Africa where she was part of a research team conducting qualitative and quantitative research on person-centered maternity care, as well as formative research on adolescent sexual and reproductive health in the Sudanese refugee population in Guereda, Chad. The studies involved a collaboration among IRC, RAISE/MSPH and the University of N’Djamena. Her areas of interest in public health include maternal and child health care/reproductive health disparities, health inequality and social determinants of health, healthcare delivery and health communication. She graduated from Fordham University in 2020 with a BA in Anthropology and a minor in Humanitarian Studies.

Hawi Teizazu, Research Assistant

Hawi Teizazu, MA, is a PhD student in the Department of Sociomedical Sciences. Her research uses a mixed-methods approach to understand the ways that health communication and media impact health-seeking behavior and policy attitudes. She is a Health Policy Research Scholar with the Robert Wood Johnson Foundation, where she focuses on translating research into policies that advance health equity. Prior to her time at Columbia, Hawi worked at CDC to strengthen data systems and address maternal and child health (MCH) disparities in Indigenous communities.  

Sadie Bergen, Research Assistant

Sadie Bergen, MA, is a fifth year PhD student in the Department of Sociomedical Sciences where she is a predoctoral fellow in Gender, Sexuality and Health. Her research examines the ways that institutions like hospitals and corporations have historically shaped reproductive health access and outcomes. Her dissertation project traces the history of neonatal intensive care in the United States. In her time at Columbia, Sadie has participated in qualitative research on a range of subjects related to reproductive health equity, including the experiences of women living with HIV and the role of pro-choice physicians play in abortion politics. 

Aaron Morrill, Research Assistant 

Aaron is a rising second year MPH student in the Department of Sociomedical Sciences and is concurrently studying towards an MA in Jewish ethics at the Jewish Theological Seminary's Kekst Graduate School. He graduated from Columbia and JTS's undergraduate joint-degree program in 2021, earning BA's in data science and Jewish thought. Aaron is currently a research assistant for two Columbia research projects outside of GATE: one centered around the impact of Covid-19 experts on Twitter; and MOVE (Marriage, Orthodox Judaism and a Vision of Empowerment), which is examining forced marriage as a social phenomenon in the Ultra-Orthodox Jewish community. His research interests include information dissemination, data communication, and the intersection of religion and public health. With GATE, Aaron is a research assistant for a qualitative study on young men's knowledge, attitudes and beliefs on menstruation. This study is aiming to bridge a key knowledge gap surrounding young, low-income, BIPOC men's knowledge and perceptions of menstruation. 

Michaela (Aela) Camozzi, Research Assistant 

Micaela (Aela) Camozzi (she/her) is a second year MPH student in the Department of Sociomedical Sciences with a certificate in Health Policy and Practice. She graduated with Honors in Public Health, BA and a minor in Ethnic Studies from University of California, Berkeley in 2020. Prior to Columbia, she engaged in field research at the Thailand-Myanmar border, focusing on the determinants of domestic violence; in addition to supporting transgender patients at a gender-affirming surgical center in San Francisco. For her practicum at Mailman, Aela joined GATE as the Sid Lerner Women and Adolescent Health Fellow (2022) and looks forward to continuing global menstrual health & hygiene and puberty research as a Research Assistant. 

Elizana - Marie Joseph, Research Assistant 

Elizana is a second year MPH student in the Department of Population and Family Health with a certificate in Health Communication. This past summer she completed her MPH Practicum at ICAP where she was part of a research team conducting formative qualitative research assessing the strengths, needs, HIV/STI-risks, and health barriers that exist for Female Sex Workers in Zambia. Prior to Columbia, Elizana worked in a hospital for several years as an HIV PrEP Specialist and Case Manager. Elizana graduated from the University of Rochester in 2017 with dual bachelor’s degrees in Public Health and English: Language, Media, and Communications. Her areas of interest within public health include topics related to health communication, sexual and reproductive health, health disparities, disability health, social determinants of health, and program evaluation.