Materials
The Download: extracting lithium, and what we still don't know about Sora
The Download: extracting lithium, and what we still don't know about Sora On a bright afternoon in August, the shore of Utah's Great Salt Lake looks like something out of a science fiction film set in a scorching alien world. This otherworldly scene is the test site for a company called Lilac Solutions, which is developing a technology it says will shake up the United States' efforts to pry control over the global supply of lithium, the so-called "white gold" needed for electric vehicles and batteries, away from China. The startup is in a race to commercialize a new, less environmentally-damaging way to extract lithium from rocks. If everything pans out, it could significantly increase domestic supply at a crucial moment for the nation's lithium extraction industry. Last week OpenAI released Sora, a TikTok-style app that presents an endless feed of exclusively AI-generated videos, each up to 10 seconds long. The app allows you to create a "cameo" of yourself--a hyperrealistic avatar that mimics your appearance and voice--and insert other peoples' cameos into your own videos (depending on what permissions they set).
SSFO: Self-Supervised Faithfulness Optimization for Retrieval-Augmented Generation
Tang, Xiaqiang, Wang, Yi, Hu, Keyu, Xu, Rui, Li, Chuang, Sun, Weigao, Li, Jian, Xie, Sihong
Retrieval-Augmented Generation (RAG) systems require Large Language Models (LLMs) to generate responses that are faithful to the retrieved context. However, faithfulness hallucination remains a critical challenge, as existing methods often require costly supervision and post-training or significant inference burdens. To overcome these limitations, we introduce Self-Supervised Faithfulness Optimization (SSFO), the first self-supervised alignment approach for enhancing RAG faithfulness. SSFO constructs preference data pairs by contrasting the model's outputs generated with and without the context. Leveraging Direct Preference Optimization (DPO), SSFO aligns model faithfulness without incurring labeling costs or additional inference burden. We theoretically and empirically demonstrate that SSFO leverages a benign form of \emph{likelihood displacement}, transferring probability mass from parametric-based tokens to context-aligned tokens. Based on this insight, we propose a modified DPO loss function to encourage likelihood displacement. Comprehensive evaluations show that SSFO significantly outperforms existing methods, achieving state-of-the-art faithfulness on multiple context-based question-answering datasets. Notably, SSFO exhibits strong generalization, improving cross-lingual faithfulness and preserving general instruction-following capabilities. We release our code and model at the anonymous link: https://github.com/chkwy/SSFO
MonitorVLM:A Vision Language Framework for Safety Violation Detection in Mining Operations
Wu, Jiang, Wu, Sichao, Ma, Yinsong, Yu, Guangyuan, Xu, Haoyuan, Zheng, Lifang, Duan, Jingliang
Abstract--Industrial accidents, particularly in high-risk domains such as surface and underground mining, are frequently caused by unsafe worker behaviors. Traditional manual inspection remains labor-intensive, error-prone, and insufficient for large-scale, dynamic environments, highlighting the urgent need for intelligent and automated safety monitoring. In this paper, we present MonitorVLM, a novel vision-language framework designed to detect safety violations directly from surveillance video streams. MonitorVLM introduces three key innovations: (1) a domain-specific violation dataset comprising 9,000 vision-question-answer (VQA) samples across 40 high-frequency mining regulations, enriched with augmentation and auxiliary detection cues; (2) a clause filter (CF) module that dynamically selects the T op-K most relevant clauses, reducing inference latency by 13.56% while maintaining accuracy; and (3) a behavior magnifier (BM) module that enhances worker regions to improve fine-grained action recognition, yielding additional gains of 3.45% in precision and 8.62% in recall. Experimental results demonstrate that MonitorVLM significantly outperforms baseline vision-language models, achieving improvements of 22.01% in precision, 34.22% in recall, and 28.37% in F1 score over the 72B unfine-tuned baseline. This study highlights the potential of multimodal large models to enhance occupational safety monitoring in mining and beyond. The vast majority of industrial accidents, including those occurring in mining and construction, originate from unsafe worker behaviors, which highlights the urgent need for continuous monitoring and timely early-warning systems [1].
An Amphibious Untethered Inchworm Soft Robot for Fast Crawling Locomotion
Javadi, Mohammadjavad, Wadds, Charlie, Chhabra, Robin
Untethered soft robots are essential for advancing the real-world deployment of soft robotic systems in diverse and multitasking environments. Inspired by soft-bodied inchworm, we present a fully untethered soft robot with a curved, flexible structure actuated by magnetic forces. The robot has a total mass of 102.63 g and demonstrates multimodal locomotion, achieving a maximum walking speed of 3.74 cm/s and a swimming speed of 0.82 cm/s. A compact and lightweight onboard control circuit enables wireless command transmission, while an integrated camera provides environmental perception. Through structural optimization and system-level integration, the robot successfully performs walking, steering, swimming, and payload transport without reliance on external infrastructure. The robot's dynamic performance and locomotion capabilities are systematically validated through experimental characterization. Introduction In nature, locomotion is enabled by deformable bodies, inspiring soft robots that mimic biological motion and functionality.
MITS: Enhanced Tree Search Reasoning for LLMs via Pointwise Mutual Information
Li, Jiaxi, Shi, Yucheng, Lu, Jin, Liu, Ninghao
Tree search has become as a representative framework for test-time reasoning with large language models (LLMs), exemplified by methods such as Tree-of-Thought and Monte Carlo Tree Search that explore multiple reasoning paths. However, it remains difficult to provide instant and reliable quantitative assessments of intermediate reasoning step quality, and extensive path exploration is computationally costly. To address this, we propose Mutual Information Tree Search (MITS), a novel framework that guides reasoning with information-theoretic principles. MITS introduces an effective scoring function based on pointwise mutual information (PMI), which enables step-wise evaluation of reasoning paths and search tree expansion via beam search without expensive look-ahead simulations, achieving superior reasoning performances while maintaining computational efficiency. The framework is complemented by an entropy-based dynamic sampling strategy that adaptively allocates computational resources to uncertain reasoning steps where exploration is most beneficial. For final prediction, MITS employs a weighted voting scheme that combines PMI scores with prediction consensus. Complex multi-step reasoning remains a fundamental challenge for Large Language Models (LLMs), particularly in tasks that require logical deduction, mathematical computation, or systematic problem-solving (Y ang et al., 2025a; Zhu et al., 2024; Yi et al., 2024). While Chain-of-Thought (CoT) prompting (Wei et al., 2022; Kojima et al., 2022) has emerged as a powerful technique to enhance reasoning by decomposing problems into intermediate steps, it typically generates a single reasoning path, which may lead to incorrect solutions due to error accumulation or the selection of suboptimal reasoning strategies. This limitation becomes particularly pronounced in complex reasoning tasks where multiple valid approaches exist, but only specific paths lead to correct answers.
High Cycle S-N curve prediction for Al 7075-T6 alloy using Recurrent Neural Networks (RNNs)
Aluminum is a widely used alloy, which is susceptible to fatigue failure. Characterizing fatigue performance for materials is extremely time and cost demanding, especially for high cycle data. To help mitigate this, a transfer learning based framework has been developed using Long short-term memory networks (LSTMs) in which a source LSTM model is trained based on pure axial fatigue data for Aluminum 7075-T6 alloy which is then transferred to predict high cycle torsional S-N curves. The framework was able to accurately predict Al torsional S-N curves for a much higher cycle range. It is the belief that this framework will help to drastically mitigate the cost of gathering fatigue characteristics for different materials and help prioritize tests with better cost and time constraints.
2025 Climate Tech Companies to Watch: Cemvision and its low-emissions cement
The startup is using waste materials and alternative fuels to make cement, slashing greenhouse gas emissions in a polluting industry. Cement is one of the most used materials on the planet, and the industry emits billions of tons of greenhouse gasses annually. Cemvision wants to use waste materials and alternative fuels to help reduce climate pollution from cement production. Today, making cement requires crushing limestone and heating it to super high temperatures, usually by burning fossil fuels. The chemical reactions also release carbon dioxide pollution. Swedish startup Cemvision made a few key production changes to reduce both emissions and the need to mine new materials.
Rubrics as Rewards: Reinforcement Learning Beyond Verifiable Domains
Gunjal, Anisha, Wang, Anthony, Lau, Elaine, Nath, Vaskar, He, Yunzhong, Liu, Bing, Hendryx, Sean
Reinforcement Learning with Verifiable Rewards (RLVR) has proven effective for complex reasoning tasks with clear correctness signals such as math and coding. However, extending it to real-world reasoning tasks is challenging, as evaluation depends on nuanced, multi-criteria judgments rather than binary correctness. Instance-specific rubrics have recently been used in evaluation benchmarks to capture such judgments, but their potential as reward signals for on-policy post-training remains underexplored. We introduce $\textbf{Rubrics as Rewards}$ (RaR), an on-policy reinforcement learning method that extends RLVR beyond verifiable domains by using rubric-based feedback. Across both medical and science domains, we evaluate multiple strategies for aggregating rubric feedback into rewards. The best RaR variant achieves relative improvements of up to $31\%$ on HealthBench and $7\%$ on GPQA-Diamond over popular LLM-as-judge baselines that rely on direct Likert-based rewards. These results demonstrate that RaR-trained policies adapt well to diverse evaluation formats, performing strongly on both rubric-based and multiple-choice tasks. Moreover, we find that using rubrics as structured reward signals yields better alignment for smaller judges and reduces performance variance across judge scales.
To Augment or Not to Augment? Diagnosing Distributional Symmetry Breaking
Lawrence, Hannah, Hofgard, Elyssa, Portilheiro, Vasco, Chen, Yuxuan, Smidt, Tess, Walters, Robin
Symmetry-aware methods for machine learning, such as data augmentation and equivariant architectures, encourage correct model behavior on all transformations (e.g. rotations or permutations) of the original dataset. These methods can improve generalization and sample efficiency, under the assumption that the transformed datapoints are highly probable, or "important", under the test distribution. In this work, we develop a method for critically evaluating this assumption. In particular, we propose a metric to quantify the amount of anisotropy, or symmetry-breaking, in a dataset, via a two-sample neural classifier test that distinguishes between the original dataset and its randomly augmented equivalent. We validate our metric on synthetic datasets, and then use it to uncover surprisingly high degrees of alignment in several benchmark point cloud datasets. We show theoretically that distributional symmetry-breaking can actually prevent invariant methods from performing optimally even when the underlying labels are truly invariant, as we show for invariant ridge regression in the infinite feature limit. Empirically, we find that the implication for symmetry-aware methods is dataset-dependent: equivariant methods still impart benefits on some anisotropic datasets, but not others. Overall, these findings suggest that understanding equivariance -- both when it works, and why -- may require rethinking symmetry biases in the data.