Lead Coordinator

Keisha Herbin Smith

Keisha Herbin Smith is the Lead Project Coordinator for the NOSES study. She received her undergraduate degree in Psychology from the University of North Carolina at Chapel Hill and her Masters’ degree at the University of North Carolina at Wilmington. After graduation, for three years, she worked for the State of North Carolina as a research specialist for the North Carolina Birth Defects Monitoring Program. For over 20 years, Keisha has worked with Dr. Merenstein at Georgetown University in various areas of research, including many probiotics trials and respiratory illness trials.  She enjoys attending her kids' many sporting events, working out, teaching bible study, and spending time with friends and family.

Project Coordinator

Jessy Sparenborg

Jessy Sparenborg, originally from Chile, graduated from Brigham Young University with a degree in Conservation Biology where she gained valuable research and teaching experience. Since 2006, Jessy has been part of the Family Medicine Department at Georgetown University, working with providers, students, and patients. She has used her native Spanish to connect with the Hispanic community, making research more accessible and fostering trust to encourage patient engagement. Jessy has contributed to several probiotic clinical trials, serving as Project Coordinator for two of them. Living in Washington, DC, Jessy enjoys outdoor adventures, drawing, camping, and hiking with her husband and their three sons, aged 15, 13, and 11.  

Project Coordinator

Tina Tan

Tina Tan, MS, CCRC, CRA is the Lead Research Program Manager for the Department of Family Medicine. She has over 15 years of experience in clinical trial operations and sponsored research, including pre- and post-award processes, protocol design and implementation, IRB and regulatory support, and budget administration. She received her MS in Clinical and Translational Research from Georgetown University and AB in Math from Bryn Mawr College. She holds active certifications from the Association of Clinical Research Professionals and the Research Administrators Certification Council.

Research Associate

Mary Truong

Mary Truong is a Clinical Research Associate at Georgetown University. She graduated from Georgetown in 2025 with a Bachelor’s in Human Science. Since 2022, she has worked in clinical research with the Department of Family Medicine as an undergraduate on multiple studies concerning antibiotic stewardship and probiotics, supporting participant recruitment, data collection, and study coordination. She now oversees day-to-day research operations, mentors research assistants, and coordinates study activities across multiple clinical sites.

Research Assistant

Mariana Verdi Pita

Mariana Verdi Pita works as a Research Assistant on the NOSES Study at Georgetown University. Originally from Peru, she graduated from George Mason University with a Bachelor’s degree in Computer Science and a minor in Chemistry. Prior to joining the NOSES team, Mariana worked in a medical oncology unit, where she gained experience supporting patients and clinical care teams. She has also participated in volunteer and service work abroad, which strengthened her interest in medicine and working with diverse communities. As a native Spanish speaker, Mariana is passionate about connecting with Spanish-speaking communities and helping make research and healthcare more accessible. Outside of work, Mariana enjoys exercising, traveling, experiencing different cultures, and spending time with family and friends. 

Research Assistant

Bridget O'Brien

Bridget works as a Research Assistant on the NOSES Study. Originally from Maryland, she moved to Connecticut for college where she received her undergraduate degree in Psychology from Fairfield University. After graduating, she lived abroad for three years in South America. Bridget's goal is to use her Spanish to expand the outreach of the study's participants into more Spanish speaking communities. She enjoys traveling, running outside, and exploring new restaurants!

Principal Investigator

David Rábago

David Rábago MD is an academic family physician working across clinical, education, and research mission areas. He maintains an active continuity of community-based clinical practice. Educational activities include clinical teaching with medical students and research-related instruction and mentorship as director of the NRSA/HRSA-funded T32 Penn State Primary Care Research Fellowship. His 22-year research program is focused on therapy for clinical concerns important to patients including upper respiratory conditions and chronic pain.

Site Project Coordinator

Joshua Blaker

Josh is a Research Project Manager in the Penn State College of Medicine’s Department of Family and Community Medicine. In his 6-year tenure, Josh has assumed responsibility for overseeing initiation, direction, and conduct of clinical trials; developing project infrastructure, standard operating procedures, and data collection instrumentation and methodology; collaborating with individuals internal and external to the project to establish and maintain relationships critical to the project’s operations; developing proposals, budgets, and research plans; and training, leading, and developing members of the research team. Effective November 2023, Josh is set to assume the role of Site Project Coordinator in the NOSES Antibiotic Stewardship Trial.

Principal Investigator

Derjung Mimi Tarn

Derjung Mimi Tarn, MD, PhD is Professor of Family Medicine at the David Geffen School of Medicine at UCLA and a practicing family physician. Dr. Tarn’s career is marked by a passionate commitment to advancing primary care research, with a particular focus on preventive health, medication adherence, and physician-patient communication. Her recent endeavors center on bolstering the utilization of preventive health services among older adults and improving clinical trial participation among underserved older adults. Dr. Tarn employs a multi-faceted approach in her research, using both qualitative and quantitative research methods, including audio recordings of office visits, semi-structured interviews, focus groups, and surveys. 

Senior Research Coordinator

Danielle Schramm

Danielle Schramm, MSPH is a Senior Research Coordinator in the Department of Family Medicine at the David Geffen School of Medicine at UCLA where she manages research projects and clinical trials funded by the National Institutes of Health and the Patient-Centered Outcomes Research Institute. Prior to her time at UCLA, she had over 10 years of experience conducting large-scale research studies and evaluation projects for the Centers for Disease Control and Prevention across a variety of health topics, including school health, obesity prevention, cancer prevention, vector-borne disease prevention, and public health emergency preparedness and response.

Danielle earned an MSPH in Health Policy & Management from the University of North Carolina at Chapel Hill and a BA in Political Science and an ABJ in Public Relations from the University of Georgia.

Research Coordinator

Aike Misawa

Aika Olario Misawa, MS, is a Research Project Coordinator in the Department of Family Medicine at the David Geffen School of Medicine at UCLA, where she recruits participants for the NOSES study. Previously, she contributed to several public health research projects in the Philippines, focusing on improving accurate history-taking with foreign patients and advancing ultrasound training and telehealth support in underserved areas.

Aika also worked on VR-based, multi-phase NIH-funded studies for obesity management at Northeastern University’s Health and Innovation Lab and served as a Research Monitor for the Sleep and Inflammatory Systems lab at Beth Israel Deaconess Medical Center in Boston.

She holds an MS in Bioinformatics and a BS in Behavioral Neuroscience with a minor in Health Science from Northeastern University. Aika is passionate about supporting public health community programs, health data analytics, and advocating for mental health awareness, particularly for healthcare workers and LGBTQI+ youth.

Research Assistant

Ellie Baron

Ellie graduated from Georgetown University with a major in Human Science and a minor in Public Health in 2025. As an undergrad, she worked in a lab studying epilepsy and contributed to a study on resilience in caregivers of homebound older adults alongside the MedStar Center for Health Equity Research team as part of her senior capstone. After graduation, she moved to Mammoth Lakes, CA, where her parents live, and worked as a tech in the ED. She moved back to her hometown of Los Angeles in Fall 2025 and began working in UCLA’s Psychiatry Neuromodulation division before joining the NOSES team in August. She plans to pursue a career in medicine and hopes to continue to engage in clinical research with a focus on promoting health equity.

Principal Investigator

Bruce Barrett

Bruce Barrett, MD, PhD, is a practicing family physician and primary care researcher. He serves as the Vice Chair of Research for the Department of Family Medicine and Community Health at the University of Wisconsin-Madison. Dr. Barrett’s current work is focused on common cold and influenza-like illness, especially as it relates to mind-body interactions and placebo effects. He is committed to doing research that reflects his values as an engaged citizen with interests in environmental health, equity, and human rights.

Research Program Manager

Shari Barlow

Shari Barlow is a Research Program Manager at the University of Wisconsin-Madison’s Department of Family Medicine and Community Health. She has over 20 years of experience managing complex clinical and community-based research projects focusing on respiratory disease transmission, antiviral prescribing practices, long-term care facility outbreak detection, and the effects of alternative medicine on acute respiratory infections. She has assisted in publishing over 35 research reports and manuscripts. Throughout her career, Shari has prioritized building connections and has found success in fostering a collaborative environment that supports open cooperation between research teams, public health entities, and laboratory teams. Shari and her research team have achieved impressive participant recruitment and retainment rates on numerous longitudinal studies, and she looks forward to applying those skills in future research endeavors.

Principal Investigator

Alex Krist

Alex Krist, M.D., M.P.H. is a Professor in the Department of Family Medicine and Population Health at Virginia Commonwealth University and an active clinician and teacher at the Fairfax Family Practice residency. He is co-director of the Virginia Ambulatory Care Outcomes Research Network, director of community-engaged research at the Center for Clinical and Translational Research, and a member of the U.S. Preventive Services Task Force. His areas of interest include community engagement, implementation of preventive recommendations, patient-centered care, shared decision-making, cancer screening, and health information technology. He is the primary author of numerous peer-reviewed publications and has presented to a wide range of audiences at national and international conferences.

Site Project Coordinator

Gaby Villalobos

Gaby Villalobos (she/her) is a Research Coordinator in the Department of Family Medicine and Population Health at VCU. Our work is centered on improving primary care through research. She is also a Practice Advocate as part of the Virginia Ambulatory Care Outcomes Research Network. Gaby has been with the department for over eight years working in various areas of research, including women’s health, substance use, and youth violence prevention.  

Principal Investigator

Sebastian Tong

Dr. Tong (he/him) is a practicing family physician, addiction medicine specialist, and health services researcher. He serves as the Associate Director of the WWAMI (Washington, Wyoming, Alaska, Montana, and Idaho) region Practice and Research Network, a practice-based research network of over 120 primary care practices. His research is informed by his clinical practice at the Harborview Family Medicine Clinic in Seattle, WA, and his areas of interest include behavioral health, loneliness, chronic pain, and unhealthy substance use. Before moving to UW, he served as a senior staff fellow from 2020-2022 at the Agency for Healthcare Research and Quality where he co-led the behavioral health and substance use research portfolios.

Research Coordinator

Astoria Ho

Astoria Ho, MIMS, (she/her) is a Research Coordinator in the Department of Family Medicine at the University of Washington. Her work is focused on research projects that advance health, improve health outcomes, and promote access to evidence-based care in primary care. Before coming to Family Medicine, she worked in the School of Public Health managing research projects and developing evidence-based programs around healthy aging and workplace wellness. She holds a Masters in Informatics Management from the UC Berkeley, and a BS in Lifespan Health from the University of Southern California.

What is the Patient Advisory Board (PAB)?  

Our Patient Advisory Board brings the patient voice into every part of the NOSES study. PAB members share their perspectives to help shape research that is practical, inclusive and focused on what really matters to patients.