South America
Adolescence lasts into 30s - new study shows four pivotal ages for your brain
The brain goes through five distinct phases in life, with key turning points at ages nine, 32, 66 and 83, scientists have revealed. Around 4,000 people up to the age of 90 had scans to reveal the connections between their brain cells. Researchers at the University of Cambridge showed that the brain stays in the adolescent phase until our early thirties when we peak. They say the results could help us understand why the risk of mental health disorders and dementia varies through life. The brain is constantly changing in response to new knowledge and experience - but the research shows this is not one smooth pattern from birth to death.
Leveraging Sidewalk Robots for Walkability-Related Analyses
Tong, Xing, Simoni, Michele D., Arfvidsson, Kaj Munhoz, Mårtensson, Jonas
Walkability is a key component of sustainable urban development. In walkability studies, collecting detailed pedestrian infrastructure data remains challenging due to the high costs and limited scalability of traditional methods. Sidewalk delivery robots, increasingly deployed in urban environments, offer a promising solution to these limitations. This paper explores how these robots can serve as mobile data collection platforms, capturing sidewalk-level features related to walkability in a scalable, automated, and real-time manner. A sensor-equipped robot was deployed on a sidewalk network at KTH in Stockholm, completing 101 trips covering 900 segment records. From the collected data, different typologies of features are derived, including robot trip characteristics (e.g., speed, duration), sidewalk conditions (e.g., width, surface unevenness), and sidewalk utilization (e.g., pedestrian density). Their walkability-related implications were investigated with a series of analyses. The results demonstrate that pedestrian movement patterns are strongly influenced by sidewalk characteristics, with higher density, reduced width, and surface irregularity associated with slower and more variable trajectories. Notably, robot speed closely mirrors pedestrian behavior, highlighting its potential as a proxy for assessing pedestrian dynamics. The proposed framework enables continuous monitoring of sidewalk conditions and pedestrian behavior, contributing to the development of more walkable, inclusive, and responsive urban environments.
Quantum Fourier Transform Based Kernel for Solar Irrandiance Forecasting
Mechiche-Alami, Nawfel, Rodriguez, Eduardo, Cardemil, Jose M., Droguett, Enrique Lopez
This study proposes a Quantum Fourier Transform (QFT)-enhanced quantum kernel for short-term time-series forecasting. Exogenous predictors are incorporated by convexly fusing feature-specific kernels. For both quantum and classical models, the only tuned quantities are the feature-mixing weights and the KRR ridge α; classical hyperparameters (γ, r, d) are fixed, with the same validation set size for all models. Experiments are conducted on a noiseless simulator (5 qubits; window length L=32). Limitations and ablations are discussed, and paths toward NISQ execution are outlined. Introduction Quantum Machine Learning (QML) is an emerging discipline that combines the principles of quantum physics with traditional machine learning (ML) to exploit the distinctive characteristics of quantum systems, including superposition and entanglement phenomena [1]. This distinction facilitates the expeditious execution of certain tasks [2], such as classification and dimensionality reduction, where QML has demonstrated significant acceleration [3]. QML applications have extended to time-series data, leveraging quantum phenomena to model complex temporal dependencies. The goal is to enhance the results of traditional tasks by performing computations on qubits, which can process data more efficiently than classical bits [4, 5]. For example, Thakkar et al. [6] demonstrated that quantum machine-learning methods could enhance financial forecasting by improving both churn prediction and credit-risk assessment. Likewise, Kea et al. [7] developed a hybrid quantum-classical Long Short-Term Memory (QLSTM) to improve stock-price forecasting by leveraging quantum data encoding and high-dimensional quantum representations.
Efficient Large-Scale Learning of Minimax Risk Classifiers
Bondugula, Kartheek, Mazuelas, Santiago, Pérez, Aritz
Supervised learning with large-scale data usually leads to complex optimization problems, especially for classification tasks with multiple classes. Stochastic subgradient methods can enable efficient learning with a large number of samples for classification techniques that minimize the average loss over the training samples. However, recent techniques, such as minimax risk classifiers (MRCs), minimize the maximum expected loss and are not amenable to stochastic subgradient methods. In this paper, we present a learning algorithm based on the combination of constraint and column generation that enables efficient learning of MRCs with large-scale data for classification tasks with multiple classes. Experiments on multiple benchmark datasets show that the proposed algorithm provides upto a 10x speedup for general large-scale data and around a 100x speedup with a sizeable number of classes.
Re(Visiting) Time Series Foundation Models in Finance
Rahimikia, Eghbal, Ni, Hao, Wang, Weiguan
Financial time series forecasting is central to trading, portfolio optimization, and risk management, yet it remains challenging due to noisy, non-stationary, and heterogeneous data. Recent advances in time series foundation models (TSFMs), inspired by large language models, offer a new paradigm for learning generalizable temporal representations from large and diverse datasets. This paper presents the first comprehensive empirical study of TSFMs in global financial markets. Using a large-scale dataset of daily excess returns across diverse markets, we evaluate zero-shot inference, fine-tuning, and pre-training from scratch against strong benchmark models. We find that off-the-shelf pre-trained TSFMs perform poorly in zero-shot and fine-tuning settings, whereas models pre-trained from scratch on financial data achieve substantial forecasting and economic improvements, underscoring the value of domain-specific adaptation. Increasing the dataset size, incorporating synthetic data augmentation, and applying hyperparameter tuning further enhance performance.
Using MLIR Transform to Design Sliced Convolution Algorithm
Ferrari, Victor, Pereira, Marcio, Alvarenga, Lucas, Leite, Gustavo, Araujo, Guido
This paper proposes SConvTransform, a Transform dialect extension that provides operations for optimizing 2D convolutions in MLIR. Its main operation, SConvOp, lowers Linalg convolutions into tiled and packed generic operations through a fully declarative transformation pipeline. The process is guided by a Convolution Slicing Analysis that determines tile sizes and data layout strategies based on input and filter shapes, as well as target architecture parameters. SConvOp handles edge cases by splitting irregular regions and adjusting affine maps where needed. All packing and tiling operations are derived from a parametric set of affine equations, enabling reusable and analyzable transformations. Although functional correctness was the primary goal of this work, the experimental evaluation demonstrates the effectiveness of SConvTransform, achieving good enough performance across different target architectures. Future work will focus on optimizing performance and porting to other target devices. When applied to standard convolution configurations, the generated code achieves up to 60% of peak performance on ARM SME and 67% on Intel AVX512. These results validate the benefit of combining static shape analysis with structured tiling and packing strategies within the MLIR Transform dialect. Furthermore, the modular design of SConvTransform facilitates integration with future extensions, enabling continued optimization of convolution workloads through MLIR's extensible compilation infrastructure.
Zelensky warns against giving away territory as latest Ukraine talks end
Talks in Geneva between the US and Ukraine aimed at ending the war with Russia have concluded, with officials from both sides reporting progress and an intention to continue working. However, no details have emerged on how to bridge the considerable divide between Moscow and Kyiv over territorial issues and security guarantees for Ukraine. Ukraine's president Volodymyr Zelensky welcomed the important steps that had been made but warned that the main problem facing the peace talks was Vladimir Putin's demand for legal recognition of Russian-occupied territories in eastern Ukraine. This would break the principle of territorial integrity and sovereignty, he said, highlighting concerns that Moscow could be rewarded for its aggression with land it seized by force. Meanwhile, President Donald Trump suggested on social media that something good just may be happening, but with the caveat: Don't believe it until you see it.
US and Ukraine announce revised peace plan: this is what we know
What is in the 28-point US plan for Ukraine? Why is Europe opposing Trump's peace plan? Is the fall of Pokrovsk inevitable? 'A corruption scandal may well end the Ukraine war' Russian drones attacked targets in Ukraine hours after the US and Kyiv announced revisions to a controversial peace plan proposed by Donald Trump. Speaking after talks in Geneva, US and Ukrainian officials agreed any deal should "fully uphold" Ukraine's sovereignty.
Are tech companies using your private data to train AI models?
Are tech companies using your private data to train AI models? Leading tech companies are in a race to release and improve artificial intelligence (AI) products, leaving users in the United States to puzzle out how much of their personal data could be extracted to train AI tools. Meta (which owns Facebook, Instagram, Threads and WhatsApp), Google and LinkedIn have all rolled out AI app features that have the capacity to draw on users' public profiles or emails. Google and LinkedIn offer users ways to opt out of the AI features, while Meta's AI tool provides no means for its users to say "no, thanks." Anthropic's AI hacking claims divide experts Posts warned that the platforms' AI tool rollouts make most private information available for tech company harvesting .
Ukraine's soldiers react to US peace plan with defiance, anger and resignation
'No one will support it': Ukraine's soldiers react to US peace plan Ukraine's frontline soldiers have reacted to draft US peace proposals with a mixture of defiance, anger and resignation. The BBC spoke to half a dozen who sent us their views via social media and email in response to the original US plan - details of which were leaked last week. Since then, American and Ukrainian negotiators have been working on changes to the proposals - and are set to continue talks about the peace framework. Of the original US plan, Yaroslav, in eastern Ukraine, says it sucks no one will support it while an army medic with the call sign Shtutser dismissed it as an absolutely disgraceful draft of a peace plan, unworthy of our attention. But one soldier with the call sign Snake told us it's time to agree at least on something.