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Deep neural networks are becoming incredibly sophisticated; they can generate realistic images, engage in complex dialogues, analyze intricate data, and execute tasks that appear almost human-like. But how do such models achieve these abilities?

In this talk, I will present a line of work that aims to explain behaviors of deep neural networks. This includes a new approach for evaluating cross-domain knowledge encoded in generative models, tools for uncovering core mechanisms in large language models, and their behavior under fine-tuning. I will show how to automate and scale the scientific process of interpreting neural networks with the Automated Interpretability Agent, a system that autonomously designs experiments on models’ internal representations to explain their behaviors. I will demonstrate how such understanding enables mitigating biases and enhancing models’ performance. The talk will conclude with a discussion of future directions, including developing universal interpretability tools and extending interpretability methods to automate scientific discovery.

Bio: 

Tamar Rott Shaham is a postdoctoral researcher at MIT CSAIL in Prof. Antonio Torralba’s lab. She earned her PhD from the ECE faculty at the Technion, supervised by Prof. Tomer Michaeli. Tamar has received several awards, including the ICCV 2019 Best Paper Award (Marr Prize), the Google WTM Scholarship, the Adobe Research Fellowship, the Rothchild Postdoctoral Fellowship, the Vatat-Zuckerman Postdoctoral Scholarship, and the Schmidt Postdoctoral Award.

We report that skin from a female woolly mammoth (†Mammuthus primigenius) that died 52, 000 years ago retained its ancient genome architecture. We hypothesize that, shortly after this mammoth’s death, the sample spontaneously freeze-dried in the Siberian cold, leading to a glass transition that preserved subfossils of ancient chromosomes at nanometer scale. This talk will explore the physics that underlies the preservation of ancient chromosomes. FOR THE LATEST UPDATES AND CONTENT ON SOFT MATTER AND BIOLOGICAL PHYSICS AT THE WEIZMANN, VISIT OUR WEBSITE: https://www.biosoftweizmann.com/

Transcription factors (TFs) bind genomic DNA regulating gene expression and developmental programs in embryonic stem cells (ESCs). Even though comprehensive genome-wide molecular maps for TF-DNA binding are experimentally available for key pluripotency-associated TFs, the understanding of molecular design principles responsible for TF-DNA recognition remains incomplete. In this talk, I will show that binding preferences of key pluripotency TFs exhibit bimodality in the local GC-content distribution. Sequence-dependent binding specificity of these TFs is distributed across three major contributions. First, local GCcontent is dominant in high-GC-content regions. Second, recognition of specific k-mers is predominant in low-GC-content regions. Third, short tandem repeats (STRs) are highly predictive in both low- and high-GC-content regions. In sharp contrast, binding preferences of a key oncogenic protein, c-Myc, are exclusively dominated by local GC-content and STRs in high-GC-content genomic regions. I will propose that the transition in the TF-DNA binding landscape upon ESC differentiation is solely regulated by the concentration of c-Myc, which forms a bivalent c-Myc-Max heterotetramer upon promoter binding, competing with key pluripotency factors. Taken together, these findings point out that c-Myc may significantly affect the genome-wide TF-DNA binding landscape, chromatin structure, and enhancerpromoter interactions.FOR THE LATEST UPDATES AND CONTENT ON SOFT MATTER AND BIOLOGICAL PHYSICS AT THE WEIZMANN, VISIT OUR WEBSITE: https://www.biosoftweizmann.com/

In my lecture, I will showcase how designing new materials and exploring their fundamental properties can lead to innovative concepts and practical applications in organic chemistry. We will begin by discussing the synthesis of novel halo-organic compounds that enable the stereoselective catalytic synthesis of biologically relevant chiral organofluorides.     The talk will primarily focus on the versatile chemistry of N-Heterocyclic Nitrenium ions (NHNs) – the nitrogen-based analogs of ubiquitous N-Heterocyclic Carbenes. We will demonstrate their unique coordination abilities, analyze their properties, and highlight their role in stabilizing elusive species.1,2 Nitrenium ions represent a novel family of nitrogen-based Lewis acids3 and serve as efficient metal-free catalysis, frustrated Lewis pairs partners4 and platform for isolating valuable radicals.5 Finally, we will demonstrate how the fundamental understanding nitrenium properties led to the development of triazenolysis reaction - an aza-version of the canonical alkene ozonolysis.6References:[1] Nat. Chem. 2011, 5, 525.[2] Chem.Sci. 2014, 5, 1305.[3] J. Am. Chem. Soc. 2017, 139, 4062.[4] Angew. Chem. Int. Ed. 2020, 59, 23476.[5] J. Am. Chem. Soc. 2022, 144, 23642; J. Am. Chem. Soc. 2024, 146, 19474.[6] Nat. Chem. 2025, 17, 101.