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Generative Medical Event Models Improve with Scale

Waxler, Shane, Blazek, Paul, White, Davis, Sneider, Daniel, Chung, Kevin, Nagarathnam, Mani, Williams, Patrick, Voeller, Hank, Wong, Karen, Swanhorst, Matthew, Zhang, Sheng, Usuyama, Naoto, Wong, Cliff, Naumann, Tristan, Poon, Hoifung, Loza, Andrew, Meeker, Daniella, Hain, Seth, Shah, Rahul

arXiv.org Artificial Intelligence

Realizing personalized medicine at scale calls for methods that distill insights from longitudinal patient journeys, which can be viewed as a sequence of medical events. Foundation models pretrained on large-scale medical event data represent a promising direction for scaling real-world evidence generation and generalizing to diverse downstream tasks. Using Epic Cosmos, a dataset with medical events from de-identified longitudinal health records for 16.3 billion encounters over 300 million unique patient records from 310 health systems, we introduce the Curiosity models, a family of decoder-only transformer models pretrained on 118 million patients representing 115 billion discrete medical events (151 billion tokens). We present the largest scaling-law study of medical event data, establishing a methodology for pretraining and revealing power-law scaling relationships for compute, tokens, and model size. Consequently, we pretrained a series of compute-optimal models with up to 1 billion parameters. Conditioned on a patient's real-world history, Curiosity autoregressively predicts the next medical event to simulate patient health timelines. We studied 78 real-world tasks, including diagnosis prediction, disease prognosis, and healthcare operations. Remarkably for a foundation model with generic pretraining and simulation-based inference, Curiosity generally outperformed or matched task-specific supervised models on these tasks, without requiring task-specific fine-tuning or few-shot examples. Curiosity's predictive power consistently improves as the model and pretraining scale. Our results show that Curiosity, a generative medical event foundation model, can effectively capture complex clinical dynamics, providing an extensible and generalizable framework to support clinical decision-making, streamline healthcare operations, and improve patient outcomes.


Evaluating Online Moderation Via LLM-Powered Counterfactual Simulations

Fidone, Giacomo, Passaro, Lucia, Guidotti, Riccardo

arXiv.org Artificial Intelligence

Online Social Networks (OSNs) widely adopt content moderation to mitigate the spread of abusive and toxic discourse. Nonetheless, the real effectiveness of moderation interventions remains unclear due to the high cost of data collection and limited experimental control. The latest developments in Natural Language Processing pave the way for a new evaluation approach. Large Language Models (LLMs) can be successfully leveraged to enhance Agent-Based Modeling and simulate human-like social behavior with unprecedented degree of believability. Y et, existing tools do not support simulation-based evaluation of moderation strategies. We fill this gap by designing a LLM-powered simulator of OSN conversations enabling a parallel, counterfactual simulation where toxic behavior is influenced by moderation interventions, keeping all else equal. We conduct extensive experiments, unveiling the psychological realism of OSN agents, the emergence of social contagion phenomena and the superior effectiveness of personalized moderation strategies.


Scientists predict the universe will end in 'big crunch'

Popular Science

Science Space Deep Space Scientists predict the universe will end in'big crunch' Starts with a bang, ends with a crunch. Breakthroughs, discoveries, and DIY tips sent every weekday. Our vast universe might not be infinitely expanding after all. Some newly reviewed dark energy data may contradict the theory first posed in 1922 by the astronomer Alexander Friedmann. According to a study recently published in the, the cosmos will actually conclude with a "big crunch."


Learning to Walk in Costume: Adversarial Motion Priors for Aesthetically Constrained Humanoids

Alvarez, Arturo Flores, Zargarbashi, Fatemeh, Liu, Havel, Wang, Shiqi, Edwards, Liam, Anz, Jessica, Xu, Alex, Shi, Fan, Coros, Stelian, Hong, Dennis W.

arXiv.org Artificial Intelligence

We present a Reinforcement Learning (RL)-based locomotion system for Cosmo, a custom-built humanoid robot designed for entertainment applications. Unlike traditional humanoids, entertainment robots present unique challenges due to aesthetic-driven design choices. Cosmo embodies these with a disproportionately large head (16% of total mass), limited sensing, and protective shells that considerably restrict movement. To address these challenges, we apply Adversarial Motion Priors (AMP) to enable the robot to learn natural-looking movements while maintaining physical stability. We develop tailored domain randomization techniques and specialized reward structures to ensure safe sim-to-real, protecting valuable hardware components during deployment. Our experiments demonstrate that AMP generates stable standing and walking behaviors despite Cosmo's extreme mass distribution and movement constraints. These results establish a promising direction for robots that balance aesthetic appeal with functional performance, suggesting that learning-based methods can effectively adapt to aesthetic-driven design constraints.


CLAPP: The CLASS LLM Agent for Pair Programming

Casas, Santiago, Fidler, Christian, Bolliet, Boris, Villaescusa-Navarro, Francisco, Lesgourgues, Julien

arXiv.org Artificial Intelligence

We introduce CLAPP (CLASS LLM Agent for Pair Programming), an interactive AI assistant designed to support researchers working with the Einstein-Boltzmann solver CLASS. CLAPP leverages large language models (LLMs) and domain-specific retrieval to provide conversational coding support for CLASS-answering questions, generating code, debugging errors, and producing plots. Its architecture combines multi-agent LLM orchestration, semantic search across CLASS documentation, and a live Python execution environment. Deployed as a user-friendly web application, CLAPP lowers the entry barrier for scientists unfamiliar with AI tools and enables more productive human-AI collaboration in computational and numerical cosmology. The app is available at https://classclapp.streamlit.app


Is this how the world will end? Scientists give terrifying glimpse into the 'Big Crunch' - and reveal the exact date it could happen

Daily Mail - Science & tech

This means that galaxies had to be closer to each other in the past. In 1964, Wilson and Penzias discovered the cosmic background radiation, which is a like a fossil of radiation emitted during the beginning of the universe, when it was hot and dense. The cosmic background radiation is observable everywhere in the universe. The composition of the universe - that is, the the number of atoms of different elements - is consistent with the Big Bang Theory. So far, this theory is the only one that can explain why we observe an abundance of primordial elements in the universe.


COSMOS: Predictable and Cost-Effective Adaptation of LLMs

Wang, Jiayu, Albarghouthi, Aws, Sala, Frederic

arXiv.org Artificial Intelligence

Large language models (LLMs) achieve remarkable performance across numerous tasks by using a diverse array of adaptation strategies. However, optimally selecting a model and adaptation strategy under resource constraints is challenging and often requires extensive experimentation. We investigate whether it is possible to accurately predict both performance and cost without expensive trials. We formalize the strategy selection problem for LLMs and introduce COSMOS, a unified prediction framework that efficiently estimates adaptation outcomes at minimal cost. We instantiate and study the capability of our framework via a pair of powerful predictors: embedding-augmented lightweight proxy models to predict fine-tuning performance, and low-sample scaling laws to forecast retrieval-augmented in-context learning. Extensive evaluation across eight representative benchmarks demonstrates that COSMOS achieves high prediction accuracy while reducing computational costs by 92.72% on average, and up to 98.71% in resource-intensive scenarios. Our results show that efficient prediction of adaptation outcomes is not only feasible but can substantially reduce the computational overhead of LLM deployment while maintaining performance standards.


COSMO: Combination of Selective Memorization for Low-cost Vision-and-Language Navigation

Zhang, Siqi, Qiao, Yanyuan, Wang, Qunbo, Yan, Zike, Wu, Qi, Wei, Zhihua, Liu, Jing

arXiv.org Artificial Intelligence

Vision-and-Language Navigation (VLN) tasks have gained prominence within artificial intelligence research due to their potential application in fields like home assistants. Many contemporary VLN approaches, while based on transformer architectures, have increasingly incorporated additional components such as external knowledge bases or map information to enhance performance. These additions, while boosting performance, also lead to larger models and increased computational costs. In this paper, to achieve both high performance and low computational costs, we propose a novel architecture with the COmbination of Selective MemOrization (COSMO). Specifically, COSMO integrates state-space modules and transformer modules, and incorporates two VLN-customized selective state space modules: the Round Selective Scan (RSS) and the Cross-modal Selective State Space Module (CS3). RSS facilitates comprehensive inter-modal interactions within a single scan, while the CS3 module adapts the selective state space module into a dual-stream architecture, thereby enhancing the acquisition of cross-modal interactions. Experimental validations on three mainstream VLN benchmarks, REVERIE, R2R, and R2R-CE, not only demonstrate competitive navigation performance of our model but also show a significant reduction in computational costs.


COSMOS: Continuous Simplicial Neural Networks

Einizade, Aref, Thanou, Dorina, Malliaros, Fragkiskos D., Giraldo, Jhony H.

arXiv.org Artificial Intelligence

Simplicial complexes provide a powerful framework for modeling high-order interactions in structured data, making them particularly suitable for applications such as trajectory prediction and mesh processing. However, existing simplicial neural networks (SNNs), whether convolutional or attention-based, rely primarily on discrete filtering techniques, which can be restrictive. In contrast, partial differential equations (PDEs) on simplicial complexes offer a principled approach to capture continuous dynamics in such structures. In this work, we introduce COntinuous SiMplicial neural netwOrkS (COSMOS), a novel SNN architecture derived from PDEs on simplicial complexes. We provide theoretical and experimental justifications of COSMOS's stability under simplicial perturbations. Furthermore, we investigate the over-smoothing phenomenon, a common issue in geometric deep learning, demonstrating that COSMOS offers better control over this effect than discrete SNNs. Our experiments on real-world datasets of ocean trajectory prediction and regression on partial deformable shapes demonstrate that COSMOS achieves competitive performance compared to state-of-the-art SNNs in complex and noisy environments.