Sirtuin 1 (SIRT1) was initially identified as an enzyme that deacetylates histones and suppresses gene activity. Since then, its roles have expanded considerably, and it is now recognized as a multifunctional protein conserved across various organisms. Despite increasing interest, it remains essential to clarify how exercise-induced changes in SIRT1 counteract multiple hallmarks of aging, as well as the full scope of SIRT1’s impact on different physiological systems. This review highlights recent findings on the short- and long-term effects of exercise on SIRT1 signaling in both rodents and humans during aging. We explore the molecular pathways activated in various tissues, providing insight into the specific biological functions of SIRT1 within aging cells. Optimal levels of SIRT1 help maintain homeostasis and a biochemical environment conducive to healthspan, influencing biological processes such as mitochondrial dynamics, metabolic pathways, tissue remodeling, autophagy, inflammatory responses, and redox balance. This indicates that SIRT1, a pleiotropic molecule, orchestrates multiple responses throughout aging. SIRT1 may act as a dynamic sensor for exercise benefits and protect against aging by maintaining genomic integrity. Different exercise protocols (acute and chronic) and modalities (aerobic, resistance, and combined training) can increase mRNA levels, activity, or protein levels of SIRT1 in various vital organs (adipose tissue, hippocampus, heart, liver, bone, and skeletal muscle) of aged animals and older adults, promoting health. Taken together, these observations support the notion that SIRT1 functions as a potential exerkine, and understanding its role in exercise-induced adaptations offers new insights into non-pharmacological strategies to enhance longevity.
Cancer survivors have a high prevalence of depressive symptoms. Moderate-to-vigorous physical activity (MVPA), sedentary time, and sleep are key modifiable behaviors associated with depressive symptoms. This study examines the associations between accelerometer-measured 24-h movement behaviors and self-reported depressive symptoms in cancer survivors. This is a cross-sectional analysis using data from the NHANES 2011–2012 and 2013–2014 cycles. The 24-h movement behaviors were measured by wrist accelerometers, including MVPA, sedentary time, and nightly sleep time. Depressive symptoms were assessed using the Patient Health Questionnaire (PHQ-9). Robust Poisson regression was used to estimate the prevalence ratio (PR) with their respective 95
BACKGROUND:Flow diverters (FDs) are increasingly used off-label for distal cerebral aneurysms (DCAs), those located at or beyond the anterior cerebral artery (ACA) A2, middle cerebral artery M2, and posterior cerebral artery P2 segments. However, data on their safety and efficacy remain limited. This systematic review and meta-analysis synthesizes current evidence on FD treatment for DCAs. METHODS:A comprehensive search was performed across PubMed, Scopus, and Web of Science, including studies with ≥5 patients reporting FD treatment of DCAs. Efficacy outcomes included adequate and complete aneurysm occlusion and retreatment rates. Safety outcomes included good functional outcome (modified Rankin Scale (mRS) score 0-2), procedure-related morbidity, mortality, complications, in-stent stenosis, and covered branch occlusion at follow-up. Pooled analyses with 95% confidence intervals (CI) were conducted using a random-effects model. RESULTS:Eighteen studies (441 patients, 70% women; mean age: 57.2±13.6 years) with 445 DCAs were included. Most aneurysms were unruptured (93.7%) and located in the ACA territory (78.4%). Adequate and complete occlusion at last follow-up were 90% (95% CI, 86 to 95) and 79% (95% CI, 74 to 85), respectively. The retreatment rate was 1.6% (95% CI, 0.2 to 3). Good functional outcome was achieved in 97% (95% CI, 95 to 99). Procedure-related complications occurred in 9% (95% CI, 5 to 13), with morbidity and mortality of 1.5% and 0.6%, respectively. In-stent stenosis and covered branch occlusion rates were 3% (95% CI, 0 to 8) and 5.5% (95% CI, 2 to 9), respectively. CONCLUSION:FDs appear to be safe and effective for DCAs, with high occlusion rates and low retreatment and complication rates.
Contemporary intelligent systems increasingly operate with high levels of autonomy, remaining formally accurate, calibrated and compliant with established performance standards. However, recent failures in large-scale sociotechnical systems suggest that harm can arise even in the absence of an explicit malfunction. This article introduces the concept of autonomous risk to describe how intelligent systems can become structurally dangerous without failing in conventional technical terms. A formal operationalization of autonomous risk is proposed as a dynamic interaction between autonomy, opacity, supervision and instability, distinguishing the baseline risk estimate from its endogenous amplification under autonomy. The proposed formulation is model-agnostic, allowing autonomous risk to be instantiated from any continuous signal of deviation from nominal system behavior, while preserving the same structural relationship between autonomy, opacity, supervision, and instability. Risk is modeled not as a discrete event or outcome, but as a path-dependent property of the system that evolves over time. Through a series of simulated decision environments, it is demonstrated that high risk is concentrated in specific regimes of partial autonomy, where systems are sufficiently independent to act, but insufficiently robust to self-correct. Empirical results reveal non-linear risk amplification, latent instability fields, and emerging schema-like trajectories that remain invisible to standard performance metrics. These findings challenge prevailing governance approaches focused on accuracy, explainability, and episodic oversight. It is argued that effective governance must shift to adaptive, trajectory-aware oversight mechanisms capable of detecting structural risks ex ante, before clear failure occurs. The framework contributes a measurable diagnostic lens to anticipate dangerous system dynamics in smart systems before collapse.
Planned cities remain underexplored in the empirical literature on urban spatial structure, particularly from a long-term perspective using high-resolution data. This paper addresses this gap by analyzing how a highly regulated, purpose-built capital has evolved, offering a contrast to the trajectories of organically developed cities. Brasília, built from scratch in 1960 and now the fourth-largest urban agglomeration in Brazil, serves as a compelling case. Using satellite data from the Global Human Settlement Layer (GHSL) at a 1 km × 1 km resolution, we describe the evolution of the urban structure of Brasília from 1975 to 2015. Population density and built-up gradients are positive, increasing with distance from the city center, and have steepened over time. This reflects faster growth at the urban fringe, the emergence of high-density clusters in suburban areas, and stable, low occupancy in the city center. Finally, we also show that Brasília's unique pattern of urban land use contrasts with other Brazilian urban agglomerations, marked by low density in the center and high levels of urban sprawl.
