Nashville
Lyft Sees a Future for Its Drivers in a Driverless World: Servicing Waymos
A team-up with Waymo in Nashville has former Lyft drivers maintaining self-driving cars. This week, Lyft riders in Nashville, Tennessee, who request a ride on the app might get matched with a new driver: a robot . A new partnership between the ride-hail company and Waymo, the self-driving-vehicle developer, will integrate self-driving rides into Lyft's platform. The rollout marks a new milestone for Lyft, which has worked with other, smaller self-driving vehicle companies in the US, but never with a partner as big as Waymo, which operates in 14 US metros. Lyft executives also see the partnership as a continuation of a conversation the ride-hail company has been having for a few years now with its hundreds of thousands of US drivers.
Watch Nashville fans lay flowers in tribute
To play this video you need to enable JavaScript in your browser. The BBC's Helena Humphrey visited the Country Music Hall of Fame in Nashville, Tennessee, on Tuesday evening as fans gathered to mourn Dolly Parton. The country music star died at the age 80 after a brief battle with cancer, her team announced. Updates from your News topics will appear in My News and in a collection on the News homepage . Watch Nashville fans lay flowers in tribute to Dolly Parton.
Viral video captures Koe Wetzel bringing young fan on stage after spotting issue in the crowd at his concert
Josh Brolin confirms Sicario 3 'is happening' as Taylor Sheridan franchise prepares to return Writer joining Lioness writers' room signals Taylor Sheridan's CIA series could have more coming An open marriage somehow leads to regret, woman hooks best friend up with sister's ex & dumb divorce excuses Austin Abrams fights to escape a 60-ton sperm whale in new'Whalefall' trailer with Josh Brolin Ella Langley's'Choosin' Texas' spends 18 weeks at number one on the Billboard Hot 100; sets new record Jill Wagner reveals the month-long boot camp'Lioness' cast endures for Taylor Sheridan's show Ella Langley's Texas photo dump sends country music fans into a frenzy online on Instagram Taylor Sheridan's'Lioness' keeps fans hooked as latest episode raises the stakes in a big way'The Simpsons' shows a teaser for new movie featuring hilarious baseball-chasing scene Brad Pitt battles the Alaskan wilderness with his combat dog in'Heart of the Beast' new trailer Innocent wrestling with sister of wife's best friend reveals cheating with a twist, McDonald's wedding & signs Lioness star Michael Kelly calls Taylor Sheridan'one of the greatest storytellers' in entertainment New York City taxpayers could pay twice under Mamdani's grocery plan US announces'Economic D-Day' against Iran Steve Doocy explores the US Air Force Academy's elite military training Dr. Marc Siegel analyzes new study suggesting GLP-1 may slow down aging Humanoid robot beats Usain Bolt's 100m dash record at Beijing games Bessent SENDS WARNING to Iran: 'We are entering the ENDGAME' South Carolina Sen. Darline Graham makes her case ahead of GOP runoff Psychologist raises questions after Lindsay Clancy's courtroom breakdowns Lindsay Clancy could be released in'not so many years' Ella Langley discusses releasing a series of singles and building momentum toward her sophomore album during coverage tied to the 2026 iHeartRadio Music Awards held March 26, 2026, at the Dolby Theatre in Los Angeles. Koe Wetzel had an awesome moment with a young fan during a recent show. Wetzel has turned into one of the biggest stars in the country music world, and his star only shines brighter with every passing day. He also recently released his new song Jaded with Ella Langley, and as expected, it's a monster hit with fans. Koe Wetzel speaks at the Omni Nashville Hotel on March 20, 2026 in Nashville, Tennessee.
Unsupervised learning of acquisition variability in structural connectomes via hybrid latent space modeling
Rudravaram, Gaurav, Zuo, Lianrui, Ramadass, Karthik, McMaster, Elyssa, Yoon, Jongyeon, Krishnan, Aravind R., Saunders, Adam M., Gao, Chenyu, Newlin, Nancy R., Kanakaraj, Praitayini, Held, Lori L. Beason, Bilgel, Murat, Barquero, Laura A., DArchangel, Micah, Nguyen, Tin Q., Cutting, Laurie B., Archer, Derek, Hohman, Timothy J., Moyer, Daniel C., Landman, Bennett A.
Acquisition differences across sites, scanners, and protocols in dMRI introduce variability that complicates structural connectome analysis. This motivates deep learning models that can represent high-dimensional connectomes in a low-dimensional space while explicitly separating acquisition-related effects from biological variation. Conventional dimensionality reduction methods model all variance as continuous, so acquisition effects often get absorbed into a continuous latent space. Recent hybrid latent-space models combine discrete and continuous components to address this, but typically require manual capacity tuning to ensure the discrete component captures the intended variability. We introduce an unsupervised framework that removes this manual tuning by architecturally annealing encoder outputs before decoding, allowing the model to adaptively balance discrete and continuous latent variables during training. To evaluate it, we curated a dataset of N=7,416 structural connectomes derived from dMRI, spanning ages 2 to 102 and 13 studies with 25 unique acquisition-parameter combinations. Of these, 5,900 are cognitively unimpaired, 877 have mild cognitive impairment (MCI), and 639 have Alzheimer's disease (AD). We compare against a standard VAE, PCA with k-means clustering, and hybrid models that anneal only through the loss function. Our architectural annealing produces stronger site learning (ARI=0.53, p<0.05) than these baselines. Results show that a hybrid continuous-discrete latent space, with architectural rather than loss-based annealing, provides a useful unsupervised mechanism for capturing acquisition variability in dMRI: by jointly modeling smooth and categorical structure, the Joint-VAE recovers clusters aligned with scanner and protocol differences.
CLT-Optimal Parameter Error Bounds for Linear System Identification
There has been remarkable progress over the past decade in establishing finite-sample, non-asymptotic bounds on recovering unknown system parameters from observed system behavior. Surprisingly, however, we show that the current state-of-the-art bounds do not accurately capture the statistical complexity of system identification, even in the most fundamental setting of estimating a discrete-time linear dynamical system (LDS) via ordinary least-squares regression (OLS). Specifically, we utilize asymptotic normality to identify classes of problem instances for which current bounds overstate the squared parameter error, in both spectral and Frobenius norm, by a factor of the state-dimension of the system. Informed by this discrepancy, we then sharpen the OLS parameter error bounds via a novel second-order decomposition of the parameter error, where crucially the lower-order term is a matrix-valued martingale that we show correctly captures the CLT scaling. From our analysis we obtain finite-sample bounds for both (i) stable systems and (ii) the many-trajectories setting that match the instance-specific optimal rates up to constant factors in Frobenius norm, and polylogarithmic state-dimension factors in spectral norm.
Towards Verified and Targeted Explanations through Formal Methods
Wang, Hanchen David, Lopez, Diego Manzanas, Robinette, Preston K., Oguz, Ipek, Johnson, Taylor T., Ma, Meiyi
As deep neural networks are deployed in safety-critical domains such as autonomous driving and medical diagnosis, stakeholders need explanations that are interpretable but also trustworthy with formal guarantees. Existing XAI methods fall short: heuristic attribution techniques (e.g., LIME, Integrated Gradients) highlight influential features but offer no mathematical guarantees about decision boundaries, while formal methods verify robustness yet remain untargeted, analyzing the nearest boundary regardless of whether it represents a critical risk. In safety-critical systems, not all misclassifications carry equal consequences; confusing a "Stop" sign for a "60 kph" sign is far more dangerous than confusing it with a "No Passing" sign. We introduce ViTaX (Verified and Targeted Explanations), a formal XAI framework that generates targeted semifactual explanations with mathematical guarantees. For a given input (class y) and a user-specified critical alternative (class t), ViTaX: (1) identifies the minimal feature subset most sensitive to the y->t transition, and (2) applies formal reachability analysis to guarantee that perturbing these features by epsilon cannot flip the classification to t. We formalize this through Targeted epsilon-Robustness, certifying whether a feature subset remains robust under perturbation toward a specific target class. ViTaX is the first method to provide formally guaranteed explanations of a model's resilience against user-identified alternatives. Evaluations on MNIST, GTSRB, EMNIST, and TaxiNet demonstrate over 30% fidelity improvement with minimal explanation cardinality.
The Geometric Alignment Tax: Tokenization vs. Continuous Geometry in Scientific Foundation Models
Foundation models for biology and physics optimize predictive accuracy, but their internal representations systematically fail to preserve the continuous geometry of the systems they model. We identify the root cause: the Geometric Alignment Tax, an intrinsic cost of forcing continuous manifolds through discrete categorical bottlenecks. Controlled ablations on synthetic dynamical systems demonstrate that replacing cross-entropy with a continuous head on an identical encoder reduces geometric distortion by up to 8.5x, while learned codebooks exhibit a non-monotonic double bind where finer quantization worsens geometry despite improving reconstruction. Under continuous objectives, three architectures differ by 1.3x; under discrete tokenization, they diverge by 3,000x. Evaluating 14 biological foundation models with rate-distortion theory and MINE, we identify three failure regimes: Local-Global Decoupling, Representational Compression, and Geometric Vacuity. A controlled experiment confirms that Evo 2's reverse-complement robustness on real DNA reflects conserved sequence composition, not learned symmetry. No model achieves simultaneously low distortion, high mutual information, and global coherence.
FT-AED: Benchmark Dataset for Early Freeway Traffic Anomalous Event Detection
Early and accurate detection of anomalous events on the freeway, such as accidents, can improve emergency response and clearance. However, existing delays and mistakes from manual crash reporting records make it a difficult problem to solve. Current large-scale freeway traffic datasets are not designed for anomaly detection and ignore these challenges. In this paper, we introduce the first large-scale lane-level freeway traffic dataset for anomaly detection. Our dataset consists of a month of weekday radar detection sensor data collected in 4 lanes along an 18-mile stretch of Interstate 24 heading toward Nashville, TN, comprising over 3.7 million sensor measurements.