The latest AI news, in focus.

El Agente F\'armaco: A Scalable AI Scientist for Drug Discovery

arXiv:2611.03832v1 Announce Type: new Abstract: Computational drug discovery offers a growing range of tools for proposing and evaluating molecules, but combining them and deciding what to do next still requires substantial expert effort. Here, we introduce El Agente F\'armaco, an AI scientist that uses modern large language model (LLM) technology to turn discovery goals expressed in everyday language into complex, scalable computational screening workflows. The agentic harness selects scientific tools, reviews their results, and adjusts subsequent steps to the target and the user's objectives. Our approach centers on a shared scientific memory: F\'armaco Atlas, which stores molecules, structures, and results together with their provenance -- a record of how they were obtained. The agent uses targeted database queries to retrieve the evidence needed for each decision. A single request can launch calculations for an entire collection of molecules, without requiring a separate LLM decision for every compound. This design limits the information the model must process as screening collections grow, while keeping the underlying results available for inspection and further analysis. The integrated tools support molecule generation, prediction of binding and molecular properties, and searches for compounds available for purchase. In a retrospective comparison with an expert-led campaign, the agent proposed chemically distinct candidates with competitive docking scores and higher calculated drug-likeness under explicitly imposed selection criteria. In a 22-task benchmark against plain tool calls and Codex, the agent achieved the highest observed mean model-judged score, with lower median cumulative token use and peak context. F\'armaco provides a foundation for flexible, scalable drug discovery workflows that connect scientific reasoning with an enduring, traceable record of computational work.

Research reveals that large language models exhibit “invisibility” bias: the rejection rate for evaluating information about Black describers reaches as high as 46%.

An empirical study published on October 24, 2026, on arXiv (paper ID 2610.30785v1) found that mainstream large language models from OpenAI and Anthropic exhibit a significant “invisibility” bias in trust assessment tasks—specifically, they systematically refuse to evaluate information when prompts contain protected attributes (such as “Black”), rather than basing their decisions on the quality of evidence; this bias is difficult to detect using conventional auditing methods.

Why it mattersThis study employs a rigorously designed two-urn Bayesian decision experiment, encompassing 6,600 sessions and 10 descriptive configurations. It is the first to quantify the cost of model‑driven rejection behavior triggered by identity labels and reveals its counterintuitive characteristics: rejection rates vary dramatically (46% for Black describers vs. 9% for White describers), yet once evaluated, Black describers actually receive slightly higher trust; moreover, bias intensifies with increasing reasoning depth, relies on specific vocabulary rather than semantics, and worsens under warning instructions—findings that carry direct implications for AI fairness assessment and alignment practices.

SIM-UT: A User Behavior Simulation and Evaluation Framework for Medical Triage Chatbots

Researchers have proposed SIM-UT (Simulation of User Behaviour for Triage), a multi-round, real-user-behavior–based evaluation method designed to identify eco‑valid failure patterns of large language model (LLM)-driven medical triage chatbots in real-world settings within low- and middle-income countries (LMICs).

Why it mattersThis framework breaks through the limitations of existing single-round, English‑centric evaluations by conducting over 5,000 rounds of multilingual simulated conversations, covering real‑world WhatsApp health programs in India, South Africa, and Kenya. For the first time, it systematically reveals “de‑escalation risk,” a critical failure mode, demonstrating both methodological innovation and significant clinical safety implications.