Welcome New Calhoun Faculty and Staff!

With the start of the school year upon us, join us in welcoming new Calhoun employees. If you see these new faces around our buildings, don’t hesitate to say hello!


Claudia Becerra: Spanish Teacher
Claudia will be teaching Spanish I, Spanish III and Spanish V. Claudia has a Ph.D. in Hispanic studies from Brown University, and she was a visiting professor at Brown. On top of her interest and expertise in Spanish, Claudia is a creative writer and is hoping to work with students on their creative writing endeavors.

Arisa Hirabayashi: Math and Computer Programming Teacher
Arisa has a B.S. in applied mathematics from the University of California, San Diego, and an M.A. in mathematics education from Columbia University. Arisa will be teaching conceptual geometry and an array of computer programming courses. We are all excited to have Arisa join our community this year, as her presence will allow us to continue to challenge students at all levels as well as help us design a more robust and engaging computer science curriculum.

Kevin Roth: English Teacher
Kevin will be teaching 9th and 10th grade English core classes, as well as a handful of English electives. He has a B.A. in history and an M.F.A. in fiction writing from Columbia University, and an M.A. in journalism from Stanford University. Kevin is deeply invested in diversity and equity work, and he hopes to continue to engage with this work at Calhoun.

Lee Kasper: Theater Production Teacher
Lee will be directing and producing all after-school shows in the Upper School, while also teaching a variety of classes during the day. Lee comes to us most recently from Success Academy, and has been the head of theater at the French Woods Festival and the associate artistic director at Theater Masters. He earned a BFA in theater from NYU - Tisch School of the Arts while also minoring in Jewish history and civilization.


Zach Leong: Science Teacher
Zach will be joining our team from the Churchill School where he's been working with middle schoolers for four years. He'll be joining our science department to head up our 6th grade science class. Zach has an MA in science education/biology from Teachers College, Columbia University and a BA in psychology from Rutgers University.

Gloribel Momin: Social Studies Teacher
Gloribel has a passion for working with middle schoolers and will be teaching social studies to our 6th graders. Gloribel has a BA in Middle East studies from Fordham University. She brings experience teaching STEM education in middle school. In addition, Gloribel has a background in new media and digital design. 


Sylvia Morales: 4th Grade Language Arts Teacher
Sylvia comes to us from Chapin where she taught 3rd grade. Sylvia earned her B.A. and master's degrees from U.C. Berkeley and earned her teaching credential from S.F. State University. She worked as a classroom teacher for many years before becoming a school based curriculum/teacher coach in San Francisco. She is an admitted education research geek and enjoys reading a myriad of teacher professional development books.

Molly O'Steen '08: Theater Arts Teacher
Molly, a Class of 2008 alum of Calhoun, is beyond thrilled to rejoin our community. She received her B.A. in theater education from Emerson College, and a dual M.S. and certification in childhood education and special education from Hunter College. Prior to joining Calhoun, Molly worked as a 3rd/4th grade teacher at the Rodeph Sholom School, and this past year was a reading, writing and social studies teacher at The Shefa School. On Saturdays, Molly is an acting and performance skills teacher at the famed Neighborhood Playhouse Junior School. She loves creating theater and inspiring a love of performance in her students, opening up their imaginations, and supporting meaningful collaboration among peers. 

Paul Weaver: Science Teacher
Paul is entering his 21st year of teaching. He comes to New York with his family from Minneapolis where he taught K-4 science at St. Paul Academy and Summit School. Prior to his teaching roles in Minneapolis, Paul taught 3rd-5th grade science in Miami at St. Stephen's Episcopal Day School. He began his teaching career at Michigan's Ann Arbor Learning Community, where he taught a 3rd-5th grade multi-aged homeroom. Paul comes to New York with his wife Dorraya, 10-year-old daughter Lilah, and his very large, sweet puppy Willow.  


Debra Jeffreys-Glass: Director of Lower School – Elementary
Debra comes to us after serving as assistant principal of the lower school at Little Red School House & Elisabeth Irwin High School (LREI) in downtown Manhattan. She was at LREI since 2014; prior to that she taught kindergarten and fourth grade and held a range of other roles at Ethical Culture Fieldston School in Manhattan. Debra's first career was as a production manager in the motion picture industry – her B.A. is in radio, television and film from Temple University. Shifting to education 15 years ago, she received master's degrees in early childhood and elementary education from Bank Street, and in private school leadership from Teachers College. A mother of two, she has been active in a number of community groups including Community Board 3, and the M'Finda Kalunga Community Garden.

Nayantara Mhatre: MS Dean of Students
Nayantara joins us from Ethical Culture Fieldston School where she served as a social studies and diversity coordinator. Prior to that, she was a middle school humanities teacher at Bank Street School for Children. Nayantara has masters' degrees in educational leadership and museum education from Bank Street College of Education and a B.A. in art history from Tufts University.

Julie Torres: US/MS Academic Dean
Julie comes to us after serving as assistant principal at Schreiber High School in Port Washington, NY. She has an M.A. in secondary science education from Teachers College and her Ed.D in education leadership from the University of Pennsylvania. Julie also brings valuable experience in horizontal and vertical articulation of curriculum at both the middle and high school levels.

Katy Saintil: Director of Administrative Services and Auxiliary Program
Katy (pronounced Kah-Tee) comes to us from the School at Columbia University, where she has served as director of external programs. Prior to that, she worked as senior program coordinator for Community Impact, a non-profit based at Columbia University that supports community service projects led by students at Columbia and Barnard. In this new role, Katy will be providing strategic leadership to our after-school and summer programming and will be the primary contact point for individuals or organizations interested in renting Calhoun's facilities. She will also oversee the 81st Street library, nurse, food services and school office. Katy is a graduate of Columbia College and holds a master's in nonprofit management from its School of Professional Studies. She has also worked with the Harlem School of the Arts and other arts organizations.

Gelin Castillo: School Office Administrative Assistant
Gelin will manage all student attendance and transportation, and will provide daily administrative support to the 81st Street building community. Gelin holds a B.A. in Political Science from John Jay-CUNY and has over a decade of experience working as a provider relations specialist at DentalSave. Prior to Calhoun, she took some time off to be with her family. During her free time Gelin enjoys traveling, reading and listening to music! 


David Alpert is now serving full-time as Director of Music and Performing Arts. 

Anthony Yacobellis is returning to a teaching role after serving as the LS - E Assistant Director. He will serve as the LS - EC Math Coordinator and teach 3rd grade math.

Liz Mavis is moving from teaching 4th grade language arts to supporting LS - E students division-wide as a Learning Specialist.

Nina Harmande is moving from her position as our 3rd-5th grade theater arts teacher into the new 3rd grade humanities position.

Meg Siddiqui is moving from her position teaching 3rd - 5th science to become the 5th grade language arts teacher.

Nina Leksin '05, who has been serving as Interim Director of Administrative Services, will be the Director of the School Office.