Graduate Medical Education Current Fellows

Noah Manning grew up in rural northeastern Vermont before attending Dartmouth College and Tufts University School of Medicine. He completed pediatric residency at UMass Chan/UMass Memorial Children's Medical Center in Worcester and is so excited to be here at Boston Children’s for his adolescent medicine training. His clinical interests include reproductive medicine, pregnant and parenting teens, substance use and addiction care, as well as reproductive endocrinology. Outside of medicine, Noah loves spending time with his wife during their adventures hiking, baking, and exploring the region’s diners and high teas. 

Nikos Angelopoulos was born and raised in Athens, Greece, and has family roots in Crete. He earned his medical degree at the University of Athens before moving to Washington, DC, to complete his Pediatrics residency at Georgetown University Hospital. He is excited to join the Adolescent Medicine Fellowship at Boston Children’s Hospital. He previously rotated with the department in June 2025 as a resident and is thrilled to return.

In addition to his clinical work, Nikos is actively involved in research, with interests in substance use and other youth risk behaviors. He also has a strong interest in medical education. Outside of work, he enjoys learning about history, politics, and philosophy; bouldering; exploring the city and nature on foot; and discovering specialty single-origin coffee

Shea Nagle, MD, MPH

Shea Nagle grew up in Upstate New York where she attended Hamilton College for her undergraduate degree and the University of Rochester for medical school. She also had a brief stint in Boston while studying at the Harvard T.H. Chan School of Public Health. She then found herself on the West Coast where she completed her Med Peds training at the University of Southern California/Los Angeles General Medical Center residency program. Shea is excited to be back in Boston for fellowship! Her clinical interests include gender affirming care, reproductive justice and family planning, health equity, patient safety, and medical education. Outside of work, Shea enjoys running, game nights, talking about how much she loves Wegmans (if you know, you know), and going on adventures with her dog Poppy.

Tim Mrowiec, MD

Tim Mrowiec grew up in the Chicago area and attended the University of Illinois College Medicine for medical school. He recently completed Pediatrics residency at Cleveland Clinic. His clinical interests include care for people with eating disorders, psychiatric conditions, and developmental differences. Tim has an academic background in bioethics, in particular exploring theological/philosophical understandings of identity, embodiment, and disability, and research ethics. That is obviously a lot of fun, so that is what Tim does for fun. Also learning anything non-medical for fun and playing strategy games. He could not have gotten this far without his wife Liz, baby Luke, and dog Jasper (in decreasing order of direct relevance to supporting his medical education).

Naseer Ahmed, MD

Naseer grew up in North Carolina and recently completed pediatric residency at UNC Chapel Hill. He is particularly interested in addressing areas such as eating disorders, substance use, and mood disorders, especially in ethnic minority and refugee adolescent/young adult communities. In his free time, he enjoys learning to draw, playing video games, and spending time with his cat!

Cassie Burley, MD, MPH

Cassie grew up in Vermont and attended Oberlin College for her undergraduate degree in neuroscience. After some time in research and public health, she attended the University of Pittsburgh for medical school before completing her pediatrics residency at the University of Colorado. Her academic interests include reducing weight stigma in healthcare, eating disorder prevention, as well as understanding the interplay of social media and human trafficking to increase teen safety online. She enjoys reading fiction, hiking, spending time on the water and with her husband and two dogs.