School of Humanities and Sciences


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  • Grant M. Rotskoff

    Grant M. Rotskoff

    Assistant Professor of Chemistry

    BioGrant Rotskoff studies the nonequilibrium dynamics of living matter with a particular focus on self-organization from the molecular to the cellular scale. His work involves developing theoretical and computational tools that can probe and predict the properties of physical systems driven away from equilibrium. Recently, he has focused on characterizing and designing physically accurate machine learning techniques for biophysical modeling. Prior to his current position, Grant was a James S. McDonnell Fellow working at the Courant Institute of Mathematical Sciences at New York University. He completed his Ph.D. at the University of California, Berkeley in the Biophysics graduate group supported by an NSF Graduate Research Fellowship. His thesis, which was advised by Phillip Geissler and Gavin Crooks, developed theoretical tools for understanding nonequilibrium control of the small, fluctuating systems, such as those encountered in molecular biophysics. He also worked on coarsegrained models of the hydrophobic effect and self-assembly. Grant received an S.B. in Mathematics from the University of Chicago, where he became interested in biophysics as an undergraduate while working on free energy methods for large-scale molecular dynamics simulations.

    Research Summary

    My research focuses on theoretical and computational approaches to "mesoscale" biophysics. Many of the cellular phenomena that we consider the hallmarks of living systems occur at the scale of hundreds or thousands of proteins. Processes like the self-assembly of organelle-sized structures, the dynamics of cell division, and the transduction of signals from the environment to the machinery of the cell are not macroscopic phenomena—they are the result of a fluctuating, nonequilibrium dynamics. Experimentally probing mesoscale systems remains extremely difficult, though it is continuing to benefit from advances in cryo-electron microscopy and super-resolution imaging, among many other techniques. Predictive and explanatory models that resolve the essential physics at these intermediate scales have the power to both aid and enrich the understanding we are presently deriving from these experimental developments.

    Major parts of my research include:

    1. Dynamics of mesoscale biophysical assembly and response.— Biophysical processes involve chemical gradients and time-dependent external signals. These inherently nonequilibrium stimuli drive supermolecular organization within the cell. We develop models of active assembly processes and protein-membrane interactions as a foundation for the broad goal of characterizing the properties of nonequilibrium biomaterials.

    2. Machine learning and dimensionality reduction for physical models.— Machine learning techniques are rapidly becoming a central statistical tool in all domains of scientific research. We apply machine learning techniques to sampling problems that arise in computational chemistry and develop approaches for systematically coarse-graining physical models. Recently, we have also been exploring reinforcement learning in the context of nonequilibrium control problems.

    3. Methods for nonequilibrium simulation, optimization, and control.— We lack well-established theoretical frameworks for describing nonequilibrium states, even seemingly simple situations in which there are chemical or thermal gradients. Additionally, there are limited tools for predicting the response of nonequilibrium systems to external perturbations, even when the perturbations are small. Both of these problems pose key technical challenges for a theory of active biomaterials. We work on optimal control, nonequilibrium statistical mechanics, and simulation methodology, with a particular interest in developing techniques for importance sampling configurations from nonequilibrium ensembles.

  • Jennifer Schwartz Poehlmann

    Jennifer Schwartz Poehlmann

    Senior Lecturer of Chemistry

    BioReaching out to Stanford’s diverse body of students and beyond to share the excitement of scientific discovery has been a growing passion for Dr. Jennifer Schwartz Poehlmann. In addition to coordinating and co-teaching Stanford’s freshmen chemistry sequence, she takes a leadership role in developing training programs for teaching assistants and enhancing classroom and lab experiences for undergraduates, while also providing STEM learning opportunities for incoming freshmen and local high school students.

    Jennifer Schwartz Poehlmann studied chemistry at Washington University in Saint Louis Missouri (A.B. 2002) before coming to Stanford University as a graduate student (Ph.D. 2008). Her thesis work under Prof. Edward Solomon addressed structural contributions to reactivity in active sites of non-heme di-iron enzymes, including ferritins. She joined the Stanford Center (now Vice Provost) for Teaching and Learning as a Teaching Fellow in 2008. In 2009, she became Lecturer and Introductory Course Coordinator for the Department of Chemistry, and in 2011 was promoted to Senior Lecturer. She has received multiple awards for her teaching and training work, including the Walter J. Gores Award for Excellence in Teaching, Dean’s Award for Achievements in Teaching, Hoagland Award Fund for Innovations in Undergraduate Teaching, and Society of Latino Engineers and School of Engineering’s Professor of the Year Award.

    Teaching
    Dr. Schwartz coordinates and co-teaches the introductory course sequence of Chem31A, 31B, and 33 for about 450 students each year. She has also created a set of companion courses (Chem31A-C, 31B-C, and 33-C) designed to provide motivated students an opportunity to build stronger study habits and problem solving tools that help them persevere in the sciences regardless of prior science background. In parallel, she has been involved in the creation and teaching of the Leland Scholars Program, which facilitates the transition to college for incoming freshman intending to study in STEM or pre-health fields.

    Instructor Training
    Dr. Schwartz has always believed that well-prepared and enthusiastic teachers inspire and motivate learning, yet excellent teaching requires training, feedback, reflection and support. She has worked both within the department and more broadly to help ensure that teaching assistants throughout the university receive the training, practice and mentorship they need to grow and excel as educators. She previously directed the Department of Chemistry’s TA Training program and, with the Vice Provost for Teaching and Learning, co-founded and directs the Mentors in Teaching Program, MinT, which provides training and resources to teaching mentors from more than 15 departments on campus. Through MinT, advanced graduate students learn effective ways to mentor TAs, through mid-quarter feedback, classroom observation, establishment of teaching goals, and workshops that enable new TAs to better engage with students in the classroom.

    Enhanced Learning Experiences
    Dr. Schwartz has been heavily involved in the development of hands-on, guided-inquiry lab activities that are now fully integrated into lab/lecture courses throughout the introductory general and organic chemistry sequence. Through the “Inspiring Future Scientists in Chemistry” Outreach Program, she is also helping to bring the excitement of exploring real-world chemistry into local high schools. She works with local high school teachers to design lab experiences that reinforce and compliment the chemistry concepts in the California State curriculum. Stanford Chemistry students take these activities to local high schools, providing hundreds of students the opportunity to work with enthusiastic young scientists while getting hands-on experience in chemistry. The program aims to demonstrate how chemistry relates to the ‘real world’ and to promote an appreciation for both science and higher education.