Inference-Time Decomposition of Activations (ITDA): A Scalable Approach to Interpreting Large Language Models

Sparse Autoencoders (SAEs) are a popular method for decomposing Large Language Model (LLM) activations into interpretable latents, however they have a substantial training cost and SAEs learned on different models are not directly comparable. Motivated by relative representation similarity measures, we introduce Inference-Time Decomposition of Activation models (ITDAs). ITDAs are constructed by greedily sampling activations into a dictionary based on an error threshold on their matching pursuit reconstruction. ITDAs can be trained in 1% of the time of SAEs, allowing us to cheaply train them on Llama-3.1 70B and 405B. ITDA dictionaries also enable cross-model comparisons, and outperform existing methods like CKA, SVCCA, and a relative representation method on a benchmark of representation similarity. Code available at https://github.com/pleask/itd

Global stability and tipping point prediction in a coral–algae model using landscape–flux theory

Coral reef ecosystems are remarkable for their biodiversity and ecological significance, exhibiting the capacity to exist in different stable configurations with possible abrupt shifts between these alternative stable states. This study applies landscape–flux theory to analyze how these complex systems behave when subjected to random environmental disturbances. We use this theory to formulate and investigate several early warning indicators of ecosystem transitions in a well-known coral reef model. We studied a number of specific indicators, including the average flux (the driving force when the system is out of equilibrium), the entropy production rate (EPR), the non-equilibrium free energy, and the time irreversibility of the cross-correlation functions. These indicators demonstrate a distinctive advantage when compared to classical indicators based on the phenomenon of critical slowing down; they exhibit turning points midway between two bifurcations, enabling them to forecast transitions in both directions substantially earlier than conventional methods. In contrast, early warning indicators based on the critical slowing down (CSD) phenomenon typically only become apparent when the system approaches the actual bifurcation or tipping point(s). Our findings offer improved tools for anticipating critical transitions in coral reef and other at-risk ecosystems, with the potential to enhance conservation and management strategies

Pathways to High-Quality Tourism Development: An Integrated Analysis of Factor Endowment, Digital Transformation, and Institutional Quality

This study explores how factor endowment, digital transformation, and institutional quality influence high-quality tourism economic development through the lens of endogenous growth theory. Using data from 30 Chinese provinces (2010–2019), it applies panel regression and fuzzy-set Qualitative Comparative Analysis (fsQCA) to identify key drivers. Findings reveal three distinct pathways to high-quality tourism economic development, with digital transformation emerging as a universal driver, even in regions with weak institutional support. Challenging conventional institutional perspectives, we demonstrate that institutional quality’s impact is not uniformly positive but context-dependent. Strong digital capabilities or abundant resources can effectively compensate for institutional weaknesses. The study extends endogenous growth theory to tourism and offers valuable guidance for policymakers to optimize resource allocation, accelerate digital transformation, strengthen institutional frameworks, and promote region-specific tourism strategies while fostering regional integration to ensure sustainable and high-quality tourism economic development

An evaluation of a one-day pain science education event in a 16–18 years school setting targeting pain-related beliefs, knowledge, and behavioural intentions: A mixed-methods, non-randomised controlled trial

Background: Public understanding of persistent pain is fraught with misconceptions. Pain education in schools may improve public understanding long-term. This study evaluated the impact of a one-day Pain Science Education (PSE) public health event delivered in a 16–18 year old school setting. Methods: This was a multi-site, non-randomised controlled, mixed-methods study with three data collection time points: baseline, post intervention, and three-month follow-up. Participants were high school students ≥16 years old. Pain beliefs, knowledge, and behavioural intentions were assessed with the Pain Beliefs Questionnaire (PBQ [organic and psychological subscales]), Concepts of Pain Inventory (COPI-Adult), a case vignette, and reflexive thematic analysis of semi-structured interviews. Results: Thirty intervention (mean age 16.6 years, 37 % female, 63 % male) and 24 control group participants (16.9 years, 63 % female, 37 % male) were recruited. Attending the pain education event was associated with reductions in Organic Beliefs [mean difference −4.4 (95 % CI, −6.0, −1.9)] and increases in Psychological Beliefs [4.6 (2.7, 6.4)] compared to the control group. This represents a shift away from biomedical beliefs in the intervention group compared to the control group. This shift was partially sustained at 3 months. A similar pattern was seen for the COPI-Adult and case vignette assessments. Semi-structured interviews (n = 13) identified an increased awareness of chronic pain and varying degrees of reconceptualisation of pain towards a biopsychosocial understanding. Conclusions: Attendance at a one-day PSE-based public health event was associated with improved knowledge, beliefs, and behavioural intentions regarding persistent pain. This exploratory study supports the need for a robust mixed-methods RCT of pain education for school children with long-term follow-up

Ice dynamics and structural evolution of Jutulstraumen, Dronning Maud Land, East Antarctica (1963-2022)

Jutulstraumen is a major outlet glacier in East Antarctica that drains into the Fimbulisen, Dronning Maud Land. Here, we present the first long-term (∼60 years) record of its behaviour using optical satellite imagery. Our analysis reveals that the ice front has been steadily advancing since its last major calving event in 1967, with a steady ice flow velocity of ∼720 ± 66m yr-1 (2000-2021), accompanied by spatially variable thickening of the grounded ice at +0.14 ± 0.04 m yr-1 (2003-2020). We also find evidence to suggest a minor grounding line advance of ∼200 m between 1990 and 2022, albeit with large uncertainties. Mapping of the major rifts on Jutulstraumen's ice tongue (2003-2022) reveals an overall increase in their length, accompanied by some minor calving events along its lateral margins. Given the present-day ice front advance rates (∼740 m yr-1), the ice tongue would reach its most recent maximum extent (attained in the mid-1960s), in around 40 years, but extrapolation of rift lengthening suggests that a major calving event may occur sooner, possibly in the late 2050s. Overall, there is no evidence of any dynamic imbalance, mirroring other major glaciers in Dronning Maud Land

La Crónica de Castilla, paradigma de la historia novelesca

Abstract: This paper is the initial outcome of the research project «Cuenta la estoria: the post-Alphonsine chronicles and the opening of the horizon of literary fiction (1284-1344)», whose aim is to engage in a systematic study of the literary shift experienced by the vernacular chronicles produced in Castile in the wake of Alfonso X’s Estoria de España at the end of the thirteenth and the beginning of the fourteenth centuries. Our chosen object of study is the Crónica de Castilla (1290-1312), a text that represents the paradigm of the genre of historical fiction, as it is the one that best displays the deliberate deployment of poetic techniques by its author. Part One, «Textual issues», provides a summary of the conclusions textual scholars have reached concerning the relationship of the chronicle with the tradition of the Estoria de España. In Part Two, «The Crónica de Castilla: dramatised history?», the close reading of a short section of the chronicle allows us to formulate its shift towards fiction in the terms of a dramatization of the historical narrative.Keywords: Crónica de Castilla, Estoria de España, post-Alphonsine chonicles, fictional history, novelisation, dramatisation

Acyclic, star and injective colouring: A complexity picture for H-free graphs

A (proper) colouring is acyclic, star, or injective if any two colour classes induce a forest, star forest or disjoint union of vertices and edges, respectively. The corresponding decision problems are Acyclic Colouring, Star Colouring and Injective Colouring. We give almost complete complexity classifications for Acyclic Colouring, Star Colouring and Injective Colouring on H-free graphs (for each of the problems, we have one open case). Moreover, we give full complexity classifications if the number of colours k is fixed, that is, not part of the input. From our study it follows that for fixed k, the three problems behave in the same way, but this is no longer true if k is part of the input. To obtain several of our results we prove stronger complexity results that in particular involve the girth of a graph and the class of line graphs of multigraphs

Why Are Plume Excess Temperatures Much Less Than the Temperature Drop Across the Lowermost-Mantle Thermal Boundary Layer?

While temperature drop across the mantle's basal thermal boundary layer (TBL) is likely (Formula presented.) 1,000 K, the temperature anomaly of plumes believed to rise from that TBL is only up to a few hundred Kelvins. Reasons for that discrepancy are still poorly understood and a number of causes have been proposed. Here, we use the ASPECT software to model plumes from the lowermost mantle and study their excess temperatures. We use a mantle viscosity that depends on temperature and depth with a strong viscosity increase from below the lithosphere toward the lower mantle, reaching about (Formula presented.) Pas above the basal TBL, consistent with geoid modeling and slow motion of mantle plumes. With a mineral physics-derived pyrolite material model, the difference between a plume adiabat and an ambient mantle adiabat just below the lithosphere is about two thirds of that at the base of the mantle, for example, 1,280 versus 835 K. 3D models of isolated plumes become nearly steady-state (Formula presented.) 10–20 Myr after the plume head has reached the surface, with excess temperature drop compared to an adiabat for material directly from the core-mantle boundary (CMB) usually less than 100 K. In the Earth, plumes are likely triggered by slabs and probably rise preferably above the margins of chemically distinct piles. This could lead to reduced excess temperatures, if plumes are more sheet-like, similar to 2D models, or temperature at their source depth is less than at the CMB. Excess temperatures are further reduced when averaged over the plume conduit or melting region