Task vectors capture how a model changes during fine-tuning by recording the difference between pre-trained and task-specific weights. The composition of task vectors, a key operator in task arithmetic, enables models to integrate knowledge from multiple tasks without incurring significant additional inference costs. In this paper, we propose variational task vector composition (VTVC), where composition coefficients are taken as latent variables and estimated in a Bayesian inference framework. Unlike previous methods that operate at the task level, our framework focuses on sample-specific composition. Motivated by the observation of structural redundancy in task vectors, we introduce a Spike-and-Slab prior that promotes sparsity and aims to preserve the most informative components. To further address the high variance and sampling inefficiency in sparse, high-dimensional spaces, we develop a gated sampling mechanism that constructs a controllable posterior by filtering the composition coefficients based on both uncertainty and importance. This yields a more stable and interpretable variational framework by deterministically selecting reliable task components, reducing sampling variance while improving transparency and generalization. Experimental results demonstrate that our method achieves state-of-the-art average performance across a diverse range of benchmarks, including image classification and natural language understanding.

We introduce a comprehensive framework for modeling single cell transcriptomic responses to perturbations, aimed at standardizing benchmarking in this rapidly evolving field. Our approach includes a modular and user-friendly model development and evaluation platform, a collection of diverse perturbational datasets, and a set of metrics designed to fairly compare models and dissect their performance. Through extensive evaluation of both published and baseline models across diverse datasets, we highlight the limitations of widely used models, such as mode collapse. We also demonstrate the importance of rank metrics which complement traditional model fit measures, such as RMSE, for validating model effectiveness. Notably, our results show that while no single model architecture clearly outperforms others, simpler architectures are generally competitive and scale well with larger datasets. Overall, this benchmarking exercise sets new standards for model evaluation, supports robust model development, and furthers the use of these models to simulate genetic and chemical screens for therapeutic discovery.

Counterfactual explanations play a pivotal role in explainable artificial intelligence (XAI) by offering intuitive, human-understandable alternatives that elucidate machine learning model decisions. Despite their significance, existing methods for generating counterfactuals often require constant access to the predictive model, involve computationally intensive optimization for each instance and lack the flexibility to adapt to new user-defined constraints without retraining. In this paper, we propose DiCoFlex, a novel model-agnostic, conditional generative framework that produces multiple diverse counterfactuals in a single forward pass. Leveraging conditional normalizing flows trained solely on labeled data, DiCoFlex addresses key limitations by enabling real-time user-driven customization of constraints such as sparsity and actionability at inference time. Extensive experiments on standard benchmark datasets show that DiCoFlex outperforms existing methods in terms of validity, diversity, proximity, and constraint adherence, making it a practical and scalable solution for counterfactual generation in sensitive decision-making domains.

Causal representation learning (CRL) is the process of disentangling the latent low-dimensional causally-related generating factors underlying high-dimensional observable data. Extensive recent studies have characterized CRL identifiability and perfect recovery of the latent variables and their attendant causal graph. This paper introduces the notion of reward-oriented CRL, the purpose of which is to move away from perfectly learning the latent representation and instead learning it to the extent needed for optimizing a desired downstream task (reward). In reward-oriented CRL, perfectly learning the latent representation can be excessive; instead, it must be learned at the coarsest level sufficient for optimizing the desired task. Reward-oriented CRL is formalized as the optimization of a desired function of the observable data over the space of all possible interventions and focuses on linear causal and transformation models. To sequentially identify the optimal subset of interventions, an adaptive exploration algorithm is designed that learns the latent causal graph and the variables needed to identify the best intervention. It is shown that for an n-dimensional latent space and a d-dimensional observation space, over a horizon T the algorithm's regret scales as O(d

Protesters clashed with police forces during a demonstration against the upcoming G7 summit in Geneva. Tear gas and a water cannon were deployed to disperse the large crowd after protesters smashed windows and set a car on fire. What needs to be understood is the message, the basic message regarding all these countries that oppress us through money and power, said one protester who was disappointed to see the protest turn violent. The G7 summit starts on 15 June in Évian-les-Bains and will bring together the leaders of Britain, France, Canada, Germany, Italy, Japan, the United States and the European Union. Pope Leo XIV says Barcelona's iconic Sagrada Família is a masterpiece of stones, colours and light during his visit to Spain.

An AI agent system proposed by researchers in Spain promises to prevent energy theft and damage to EV chargers, as well as the critical energy infrastructure that powers them. The number of electric vehicles on roads around the world continues to grow. The boom in EV adoption has driven the development of accessible, fast, and efficient charging infrastructure. However, this expansion also brings with it new cybersecurity risks that have been not been widely studied, and for which there are still few viable solutions. Cristina Alcaraz, an infrastructure-security researcher at Spain's University of Malaga, explains that the liability of electric-vehicle charging stations is due to the fact that they integrate multiple physical and digital components.

Follow this author to personalize your feed and get instant alerts. Follow Go to your personalized feed WHY FOLLOW? Smart Alerts: Get notified about major news as it happens. Carlos Alcaraz, the 23-year-old tennis phenom from Spain, combines the physicality of his countryman Rafael Nada l and the drop-shot artistry of Roger Federer, and his complete package may help him obliterate the record books. After winning the 2022 U.S. Open, Alcaraz became the youngest world No. 1 in men's tennis history.

Follow this author to personalize your feed and get instant alerts. Follow Go to your personalized feed WHY FOLLOW? Smart Alerts: Get notified about major news as it happens. Spanish midfielder Aitana Bonmatí, the reigning three-time winner of both the Best FIFA Women's Player award and the Ballon d'Or Féminin, is the best women's soccer player on the planet. She led Spain to its first women's World Cup title in 2023, and her pro team, Barcelona, has won the Liga F title seven years running and Champions League crowns in 2021, 2023, 2024, and 2026; Bonmatí has been named the Champions League Player of the Season three times.

Model-assisted interval designs such as the Keyboard design are transparent and easy to implement in phase I oncology trials. However, interim decisions based solely on data from the current dose may overlook informative signals from neighbouring doses, leading to unnecessary escalation or de-escalation. We propose the shared Keyboard design, a Bayesian model-assisted design that replaces the independent beta--binomial updating scheme at each dose with a posterior induced by a Beta kernel process using kernel-weighted pseudo-counts. The design preserves the decision structure of the Keyboard design while enabling controlled borrowing across nearby doses. To prioritise overdose control, we propose an asymmetric kernel that assigns greater weight to toxicities observed at higher doses during escalation. We further extend the proposed design to accommodate adaptive dose insertion when the initial dose grid is inadequate and time-to-event outcomes when late-onset toxicities are present. Extensive simulation studies demonstrate substantial improvements in both accuracy and safety for identifying the maximum tolerated dose. In settings involving dose insertion, the proposed design identifies inserted target doses more effectively than adaptive dose modification while maintaining a comparable modification rate.

MV Hondius, the Dutch cruise ship hit by a deadly hantavirus outbreak, has docked at its final destination in Rotterdam. Only the ship's crew were aboard for the last leg of the journey, as all passengers docked off the ship in the Canary Islands between 10 and 11 May. Rotterdam port harbour master René de Vries said 25 mobile homes kitted out with catering and satellite communications would be available for the crew to self-isolate in. Three people - a Dutch couple and a German woman - died after travelling on the ship, with two of them confirmed to have had the virus. The World Health Organization has so far reported 10 cases in total, eight confirmed and two suspected.