PNAS Nexus

Abstract Large Language Models (LLMs) are being applied in a wide array of settings, well beyond typical language-oriented use cases. In particular, LLMs are increasingly used as a plug-and-play method for generating predictions on tabular data. Prior work has shown that LLMs, via in-context learning or supervised fine-tuning, perform comparably with many tabular supervised learning techniques. H…

Abstract The classical Ginzburg–Landau model has long provided the foundation for modeling superconductivity, yet it does not fully capture the rich diversity of unconventional superconducting phenomena observed experimentally. Examples include magnetic superconductors, re-entrant superconductivity, and the cuprates—materials whose behaviors are not adequately explained by traditional Ginzburg–La…

Abstract Inosine modification on tRNA anticodon (I34) is universally conserved in three kingdoms of life and critical to tRNA decoding capabilities. We found that tRNALeu(IAG) in commensal human bacterial families in Lactobaccilalles is concurrent with genome-wide synonymous leucine codon reprogramming. Pathway analysis reveals significant synonymous Leu codon changes in proteins in multiple KEGG…

Abstract The decarbonization of electric power systems is a critical step in mitigating climate change and achieving global climate targets. Yet current approaches often address policy, markets, technology, and consumer behavior in isolation, making it difficult to design coherent and adaptive decarbonization pathways across stakeholders. To address this gap, we propose a three-layer, feedback-or…

Abstract Universally, humans value communicating information about themselves to others, and exchanges of such information between two individuals are fundamental to social bond formation. Yet, people often keep information private, potentially forfeiting the chance to connect with someone new. In this preregistered functional magnetic resonance imaging (fMRI) study, participants who experienced …

Abstract Can incremental market reforms stimulate clean energy transitions in coal-dependent systems? China’s electricity spot market pilot in Guangdong, which is a regulated experiment in partial liberalization, reveals how even limited market exposure can spark systemic transformation. Leveraging quarter-hourly, unit-level generation data and a novel causal inference approach, we demonstrate th…

Abstract Fine-tuning Large Language Models (LLMs) on some task-specific datasets has been a primary use of LLMs. However, it has been empirically observed that this approach to enhancing capability inevitably compromises safety, a phenomenon also known as the safety-capability trade-off in LLM fine-tuning. This paper presents a theoretical framework for understanding the interplay between safety …

Abstract Klebsiella pneumoniae (Kp) is a leading cause of hospital- and community-acquired infections and is increasingly resistant to last-line antibiotics, positioning it as a World Health Organization-designated priority pathogen. Vaccine development has been hindered by the extensive diversity of Kp exopolysaccharide capsules. We developed a cellular nanoparticle (CNP) platform in which bacte…

Abstract Conservatives are more likely than liberals to oppose climate policies, resulting in political polarization over climate change. Most research treats this gap as if it reflects two cohesive blocs on opposite sides of an issue. Drawing on original survey data from a probability sample of Canadians (n=2,503), we find that while liberals are highly uniform in their orientation toward climat…

Abstract Contamination of drinking water with toxic arsenic affects more than 170 million people worldwide. Because arsenic is tasteless, colorless, and odorless when mixed with water, almost all people consume it unknowingly and suffer from health impairments (like skin-related diseases or cancer). Running a randomized controlled trial with 2,334 Indian households, we show that providing inexpen…

Abstract Existing research on AI cultural biases predominantly focuses on Western models, overlooking critical gaps in non-Western models. We conduct a comparative analysis of AI models – ChatGPT (U.S. developed) and ErnieBot (China developed) – from different cultures to investigate how corresponding cultural biases manifest in their outputs. Additionally, we examine how cultural alignment betwe…

Abstract Humans are uniquely capable of producing highly efficient tools, but the extent to which this capacity depends on individual reasoning abilities remains unclear. In particular, the respective roles of causal and technical reasoning versus cultural transmission in driving technological improvement are the subject of long-standing debate. We address this question by directly manipulating c…

Abstract Sharp disagreements about social issues have raised concerns about increasing societal polarization in democracies worldwide. While diversity of opinion is vital for democratic engagement and can promote innovative solutions, social science research shows that such disagreements can undermine social cohesion and erode social trust if they turn into identity-based conflicts. The present r…

Abstract The Consumer Financial Protection Bureau (CFPB) maintains a centralized complaint intake and routing system, yet whether company response timeliness differs across demographic groups and neighborhoods remains under-investigated. We analyze over 1.27 million consumer financial complaints submitted between 2014–2022 to assess whether older adults and service-members face disparities in com…

Abstract Aging induces physical changes in organisms, many of which are at the cellular level, but the mechanisms underlying these changes are poorly understood. While the cytoplasm provides a crucial physical environment to host essential cellular processes, how its properties change in aging remains largely unknown. Here, using cells from well-established aging mice models, we first investigate…

Abstract Various biological and synthetic media out of equilibrium can be viewed as many-ratchet systems that rectify environmental noise through local measurements and information processing, like Maxwell's prototypical demon. These systems pose a challenge to standard coarse-graining approaches because they are described in terms of decision-making protocols similar to computer programs rather …

Abstract We have discovered a highly specialized innervation of the forebrain by pituitary adenylate cyclase activating polypeptide (PACAP) immunohistochemistry originating from the brain stem that uses glutamate, acetylcholine and PACAP and other peptides as neurotransmitters. The parent neurons of the axons are in the Kölliker-Fuse nucleus and their terminals form calyx-like multi-release site …

Abstract Peri-implantitis (PI) is a treatment-resistant inflammatory condition that affects millions of patients with dental implants, leading to destructive loss of jawbone, implant failure, and escalating healthcare costs. It is classically attributed to bacterial biofilms; however, unlike periodontitis, it frequently progresses despite resolution of infection with standard antimicrobial therap…

Abstract Cryopreservation by vitrification typically requires 30–50 v/v% of cytotoxic penetrable cryoprotective agents (CPAs) to prevent ice crystal formation during freezing and thawing, limiting its broader application. Since pressure suppresses ice crystallization, applying high pressure during vitrification may enable reducing CPA concentrations while maintaining cell viability. In this study…

Abstract Reactive oxygen species (ROS), including superoxide, are central molecules in eukaryotic growth, function, and immunity. While some corals have been associated with high extracellular superoxide concentrations, such as Porites species, we lack a clear understanding of superoxide production dynamics and purpose. Here, we combine extracellular superoxide concentration and decay rate measur…