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Spatiotemporal changes in river flow seasonality and predictability using Colwell indices in Northwestern Iran
Abstract The study aimed to examine seasonal-spatial changes in river flow regimes in northwestern Iran using Colwell indices, which assess the regularity and seasonal pattern of flow through three components: Predictability, Constancy, and Contingency. This study is the first to apply Colwell indices across rivers in northwestern Iran, revealing varied trends influenced by climate and human activities. In this study, river flow data from various rivers in northwestern Iran with climate diversity were used to analyze the time and spatial changes of river flow regimes. In this regard, using the Colwell indicators, the variations of the different components of the river flow regime were evaluated from three main aspects including Predictability (P), Constancy (C) and Contingency (M) on different daily, monthly and seasonal time scales. The results showed that the ArbabKandi river had the highest Predictability and Constancy in its currents with values of P_MaxM = 0.739 and C_MaxM = 0.651 and Nir with values of P_MinS = 0.64 and C_MinS = 0.42, while the dostbeglo and Hir Rivers had the lowest values. Analysis of maximum, minimum and average of Colwell indicators of the flow regime showed significant differences between rivers due to the influence of various climatic factors or human exploitation. Trend analysis in Ardabil Province based on the Modified Mann-Kendall test reveals significant river flow decreases at stations such as Samian (S = − 649), Borran (S = − 639), Dostbeglo (S = − 643), and Mashiran (S = − 665), while Abgarm ( p = 0.55), AhleIman ( p = 0.50), Hir ( p = 0.22), and ShamsAbad ( p = 0.15) show no significant trends. Moderate but significant declines are observed at Arbabkandi, Barough, Gilandeh, Hajahmadkandi, Nir, Nuran and Viladaragh ( p < 0.05). The study emphasizes the importance of understanding the variability of river flow regimes and river flow discharge values and can help improve water resource management strategies and better predict future changes.
Why working from home varies across countries and people
We investigate why work from home (WFH) rates vary so widely across countries using the Global Survey of Working Arrangements (G-SWA). Conducted in late 2024 and early 2025, G-SWA is the only harmonized international survey of remote work, covering 14,427 full-time, college-educated workers across 37 countries. Our analysis finds that cultural individualism accounts for 29 percent of the cross-country variation in WFH rates—more than any other single factor. Industry structure, population density, and economic development account for smaller shares of the cross-country variation. We conclude with brief remarks on the broader role of culture in shaping the future of work and its implications for labor market policy.
Enhancement of PID controller performance for a combined LFC and AVR single- and two-area model using exponential distribution optimization technique
Abstract This study presents the exponential distribution optimization (EDO) technique for tuning the proportional-integral-derivative (PID) controller parameters in combined load frequency control (LFC) and automatic voltage regulation (AVR) for both single- and two-area electrical power system models. The objective is to enhance system performance by minimizing frequency and voltage deviations. The proposed approach leverages widely adopted objective functions, namely, the integral time squared error (ITSE) and the integral time absolute error (ITAE) to effectively reduce control errors while improving system stability and transient response. The EDO algorithm iteratively refines PID parameters by selecting optimal values from evolving solution populations, with system disturbances introduced to evaluate robustness under varying operating conditions. Simulation results demonstrate significant improvements, including a 16.52% reduction in LFC undershoots and a 33.3% improvement in AVR steady-state error in single-area systems, and up to 13.2% faster settling times in two-area systems. The EDO-based controller achieves faster dynamic responses, smoother operation, and complete elimination of steady-state errors while maintaining balanced frequency overshoot and minimized transient oscillations. Comparative analyses confirm the method’s superiority over established optimization techniques. A comprehensive robustness further validates the reliability and effectiveness of the EDO-tuned PID controller, underscoring its strong potential for ensuring power system stability.
Unusually broad-spectrum small-molecule sensing using a single protein scaffold
Small-molecule sensing in plants is dominated by chemical-induced dimerization modules. In the abscisic acid (ABA) system, allosteric receptors recruit phosphatase effectors and achieve nM in vivo responses from µM receptor–ligand interactions. This sensitivity amplification could enable ABA receptors to serve as generic scaffolds for designing small-molecule sensors. To test this, we screened collections of mutant ABA-receptors against 2,726 drugs and other ligands and identified 553 sensors for 6.6% of these ligands. The mutational patterns indicate strong selection for ligand-specific binding pockets. We used these data to develop a sensor design pipeline and isolated sensors for multiple plant natural products, 2,4,6-trinitrotoluene (TNT), and “forever” per- and polyfluoroalkyl substances (PFAS). Thus, the ABA sensor system enables design and isolation of small-molecule sensors with broad chemical scope and antibody-like simplicity.
Fourier-plane wavefront and SLM aberration characterization via iterative scanning of beam deflector segments
Abstract This study presents a method for characterizing the effective incident wavefront in the Fourier plane, eliminating the need to decouple measurement and application. The amplitude and phase of this wavefront are cumulatively affected by the incident beam, the curvature of the backplane, and the defocus introduced by the Fourier lens. Using an iterative camera-in-the-loop approach, this method displays square patches of beam deflection phase ramps on the spatial light modulators (SLMs), and the resultant spots in the Fourier plane are positionally controlled. The parameters of each patch are used to reconstruct the phase and amplitude profiles of the wavefront. These profiles are used in hologram computation to correct for SLM aberrations and improve image quality. The proposed method has been experimentally verified to work with off-axis and on-axis optical systems, showing the versatility of the approach.
Long-term exposure to wildfire smoke and mortality: Heterogeneous effects by exposure metric and across subpopulations
Wildfire smoke, once rare, is a hazard that populations across the globe are increasingly exposed to repeatedly. Evidence of acute health effects of wildfire particulate matter (PM 2.5 ) is growing, but less is known about long-term effects related to repeated exposures. Using a cohort of 1,250,083 Kaiser Permanente Southern California members aged ≥60, we estimated the association between all-cause mortality and 3-y exposure to five different census tract–level wildfire smoke metrics (mean daily wildfire-specific PM 2.5 , mean daily wildfire-specific PM 2.5 during the peak wildfire week, number of days with daily wildfire-specific PM 2.5 > 0 μg/m 3 , number of weeks with average wildfire-specific PM 2.5 > 5 μg/m 3 , and number of smoke waves). We applied a discrete-time approach with pooled logistic regressions, adjusting for sex, age, race and ethnicity, marital status, smoking status, requiring an interpreter, calendar year, and census tract–level poverty and population density. When comparing those highly exposed (95th percentile) to those minimally exposed (5th percentile), we found an increased odds of mortality across all five wildfire smoke metrics. Mean daily wildfire PM 2.5 was the metric most strongly associated with mortality (odds ratio: 1.07; 95% CI: 1.05, 1.09). We observed greater vulnerability to the long-term effects of smoke for individuals under age 75, or with Black or Other racial/ethnic identity, or living in a census tract with higher poverty. Identifying the most harmful long-term wildfire smoke metric and most-at-risk populations can help focus attention for developing effective adaptation strategies in a changing climate.
Relating estuarine turbidity maxima to tide and river conditions
Hormonal mechanisms of women’s risk in the face of traumatic stress
Women are underrepresented in biomedical research, limiting understanding of their disproportionate rates of stress-related disorders. Although men experience more trauma, women are twice as likely to develop posttraumatic stress disorder (PTSD). We tested whether ovarian hormones contribute to this disparity via their influence on threat-related brain activity. In a randomized, double-blind crossover study of 110 young women, we examined how exogenous estradiol (E2) modulates threat neurocircuitry, timed precisely to ovarian phase. E2 increased engagement of the ventromedial prefrontal cortex and, in the early luteal phase, reduced central and corticomedial amygdala reactivity to threat in women with little trauma history, but not those with PTSD. Fluctuations in E2 therefore modulate neural responses to threat, and sensitivity to these fluctuations may underlie women’s heightened vulnerability to stress-related disorders.
Personalisation of the Dutch combined lifestyle intervention SLIMMER improves participant retention and weight loss in people at risk for cardiometabolic disease
The COVID-19 pandemic had heterogeneous effects on migration dynamics
Multilabel feature selection using graph neural networks and differential evolution optimization
Oxytocin varies across the life course in a sex-specific way in a human subsistence population
Oxytocin, a hormone linked to reproduction and health, may mediate life-history trade-offs across the human life course. Yet, how oxytocin naturally varies with age remains poorly understood. Here, working with the Tsimane, forager-horticulturalists of lowland Bolivia, we collected the largest sample of oxytocin measurements to date (n = 1,242 samples, n = 405 individuals, age = 2 to 84 y, 51% female), and i) examined how oxytocin varies throughout the life course in females and males, and ii) investigated potential drivers of age- and sex-specific variation. Our sample provides rare insight into the relationship between oxytocin and age in a context where energy is limited and trade-offs between reproduction and somatic maintenance are more salient. We found that oxytocin follows a nonlinear sex-specific trajectory throughout the life course. In females, oxytocin levels were high during the reproductive years and declined in the early to midforties, a pattern largely explained by breastfeeding and, to a lesser extent, childcare and good self-rated health. In males, oxytocin was low in early adulthood but high in old age, and although higher oxytocin was linked to good self-rated health, this did not explain the rise in oxytocin in later life. These findings suggest that oxytocin is instrumental for reproduction and caregiving in females and may also be associated with health in both males and females. Together, our work highlights oxytocin’s broader biological significance across the human life course, suggesting that it may play a pivotal role in coordinating age- and sex-specific trade-offs involving reproduction and health.
Vitamin D3 attenuates hepatic inflammation in primary biliary cholangitis by inhibiting TLR4/NF-κB mediated M1 macrophage polarization
Association between muscle-specific strength and inflammatory biomarkers in community-dwelling older women: a cross-sectional study
Fluctuation theorems for autonomous work
Classical fluctuation theorems for work have been obtained theoretically, and verified experimentally, within a nonautonomous framework in which work is performed on a system of interest, S , by the external manipulation of a work parameter, such as a piston’s position. Here, we obtain fluctuation theorems within an autonomous framework in which S exchanges energy with a reversible work source, R . The two subsystems, R and S , interact with one another as they evolve under Hamiltonian or stochastic dynamics, without external intervention. In this setting, we must account for the backaction of S on R , which is absent in the nonautonomous setting. We obtain autonomous versions of standard fluctuation theorems for work and entropy production. In each case, we argue, the autonomous fluctuation theorem reduces to its nonautonomous counterpart when R ’s inertia becomes infinitely large.
Rapid thickness distribution prediction of superplastic formed parts based on geometry adapted PSO-BP neural network surrogate model
Seismic response and fragility analysis of BRB-retrofitted highway pile-slab structures with an improved load-transmission path
Precursory electrical resistivity signatures of shear failure in saturated sandstone under varying shear rates
Reviving Vavilov’s vision: The tragedy of biodiversity governance and principles for reform
This perspective addresses two of humanity’s greatest challenges: feeding a growing population and conserving biodiversity. We begin by examining the legacy of Nikolai Vavilov, who pioneered the improvement of crops such as wheat and beans by hybridizing them with their wild relatives. This strategy used wild species biodiversity to introduce new genetic variation into crops, making them more resilient and productive. Its adoption around the world greatly increased food security and brought lasting benefits to humanity. However, since the 1990 s, well-intentioned laws shifted the governance of biodiversity from a shared global resource to the sovereign control of nation states, with serious unintended consequences. These changes have disrupted the collection, preservation, exchange, and use of biodiversity, all of which are central to Vavilov’s strategy for crop improvement and to biodiversity science more broadly. Efforts at reform have been frustrated as the issues became moralized, inhibiting the open dialogue needed for change. Using foundational concepts shared by science and good governance, we propose seven empirically grounded principles for reform, to help realign biodiversity governance with its intended aims. We then illustrate one possible framework—underpinned by global financing to protect biodiversity hotspots—that would align incentives and work in synergy with the principles to foster practical reform. The principles, together with frameworks that align incentives, would create the conditions for stronger biodiversity conservation and research, agricultural development, global food security, and all the associated benefits to humanity.