Cherie Kagan, Daniel Krashen, George Pappas, Kai Tan, and Patrick Walsh are among the nearly 500 scientists, engineers, and innovators honored by the Association for the Advancement of Science this year for distinguished contributions to their fields.
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(Top, from left) Cherie Kagan, Daniel Krashen, and George Pappas. (Bottom, from left) Kai Tan and Patrick Walsh.
AAAS, a society with a mission to “advance science, engineering, and innovation throughout the world for the benefit of all,” has named a class of Fellows since 1874. This year’s honorees will be celebrated at a forum in Washington, D.C., in June.
Daniel Krashen is the Presidential Professor of Mathematics. Krashen’s research is in algebra and arithmetic geometry, including the study of division algebras, quadratic forms, local-global principles, moduli stacks, and derived categories. These areas have connections to a wide range of fields, including physics and cryptography. He has been awarded multiple NSF grants, including a CAREER award, as well as the prestigious Presidential Early Career Award for Scientists and Engineers (PECASE). He is a Fellow of the American Mathematical Society. His publications have appeared in top journals including Inventiones mathematicae, Advances in Math, IMRN, and Crelle’s Journal. Krashen has also been active in promoting outreach and diversity in mathematics at a range of levels from middle school through early career professors.
George Pappas is the UPS Foundation Professor in the Department of Electrical and Systems Engineering at Penn Engineering. He also holds secondary appointments in the Department of Computer and Information Sciences and the Department of Mechanical Engineering and Applied Mechanics. He currently serves as the associate dean for research and innovation in Penn Engineering and as the director of the Raj and Neera Singh Program in Artificial Intelligence. Pappas’ research focuses on control systems, robotics, autonomous systems, formal methods, and machine learning for safe and secure cyber-physical systems. He has received numerous awards, including the NSF PECASE, Antonio Ruberti Young Researcher Prize, George S. Axelby Award, O. Hugo Schuck Best Paper Award, and George H. Heilmeier Faculty Excellence Award. He is a Fellow of the Institute of Electrical and Electronics Engineers and the International Federation of Automatic Control, and he was elected to the National Academy of Engineering in 2024.
Kai Tan is the Richard and Sheila Sanford Professor at the Children’s Hospital of Philadelphia and professor of pediatrics in the Perelman School of Medicine. His research combines experimental genomics and computational modeling to uncover mechanisms of gene regulation in cellular development and cancer. Tan has made seminal contributions to scientists’ understanding of stem cell development within bone marrow, mapping its trajectory and identifying key transcriptional regulators and enhancers that govern this process. He has also developed computational methods to identify noncoding mutations that disrupt transcriptional regulatory networks and rare therapy-resistant cells that contribute to treatment failure. Tan has contributed significantly to major National Institutes of Health-sponsored scientific initiatives, including the Cancer Systems Biology Consortium and the Human Tumor Atlas Network.
Patrick J. Walsh is the Rhodes-Thompson Professor of Chemistry at Penn Arts & Sciences. His research focuses on catalysis and chemical synthesis, developing new reactions that help chemists build useful molecules more efficiently. Walsh’s group studies unusual forms of chemical reactivity that can simplify how complex compounds are made, including the discovery of 2-azaallyl anions, highly reactive molecules that act as powerful “super electron donors.” These reactions enable chemists to assemble complex structures without relying on transition metals, opening new paths for making pharmaceuticals and other useful compounds. He co-authored the textbook “Fundamentals of Asymmetric Catalysis”with Penn colleague Marisa Kozlowski and directs Penn’s Chemistry Research Experiences for Undergraduates program with Marta Guron.
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