Browse Articles

Dynamics of bioactive compounds and antioxidant activity of Guazuma ulmifolia Lam. fruits and pulp rheology throughout development

Algal Betaine Triggers Bacterial Hydrogen Peroxide Production that Promotes Algal Demise

The effect of laser pulse on nonlinear thermoelasticity using an advanced analytical method

Abstract This study presents a detailed analytical exploration of exact wave solutions under the Green-Naghdi type II (G-N II) thermoelastic theory, emphasizing the role of laser pulse interactions and temperature-sensitive material properties. By employing the Modified Extended Direct Algebraic (MEDA) method, the work derives precise closed-form solutions for the governing thermo-mechanical equations, elucidating the coupled thermal and elastic wave propagation in deformable solids. The central theme of the investigation revolves around how the presence of laser pulse phenomena and the variation of material parameters with temperature significantly influence the response of thermoelastic media. These factors are shown to be critical in dictating the behavior of stress and thermal distributions under varying mechanical and thermal loading conditions. The MEDA approach proves to be a powerful and adaptable mathematical tool, as it facilitates the construction of broad families of wave solutions, each containing arbitrary constants that allow for modeling a diverse array of physical scenarios. By incorporating these free parameters into the solution structures, the study greatly expands the set of exact solutions available, enabling a more comprehensive analysis of wave behavior under distinct environmental and loading circumstances. The derived solutions provide meaningful insights into how wave propagation is affected in thermoelastic systems, particularly in terms of variations in wave velocity, attenuation, and energy transport mechanisms when subject to laser-induced thermal excitation and non-constant material characteristics. In addition to the analytical development, the research supports its theoretical predictions through graphical depictions of various important physical quantities, including stress, displacement, and temperature profiles. A comprehensive parametric investigation is conducted to rigorously examine the influence of multiple key parameters, including laser pulse duration, material properties, and exposure time, in addition to pulse intensity. These visualizations clearly reveal the complex and dynamic interplay between thermal and mechanical influences, especially when external sources such as laser pulses are introduced. This study enhances the comprehension of thermoelastic wave propagation in modern materials exhibiting temperature-dependent behavior.

Grounded reconfigurable metamaterials with customized mapping-invariant behavior

Abstract Mechanical behavior of synthetic materials depends on their microstructure and geometric configurations. This dependency leads to unintended performance when the material remaps its microstructures for shape reconfigurations, such as diminished rigidity in unfolded aerospace morphing structures and reduced sensitivity in twisted soft sensors. Breaking this dependency through material design to improve overall performance has been a long-standing challenge. This work develops a transformation method to design a class of grounded metamaterials that decouples mechanical behavior from microstructure and shape reconfigurations. We fabricate these metamaterials and experimentally demonstrate both configuration-mapping-invariant displacement behavior and unconventional displacement control functions that have not previously been observed. We identify two physical principles that underpin the useful, but counterintuitive behavior: (i) Mapping-invariant displacement fields are the result of body torques that automatically balance non-concurrent internal forces from microstructure reconfigurations; (ii) Tailored displacement control functions are determined by Willis springs pinned to the ground. As a result, the grounded metamaterials are shown to enable the design of highly reconfigurable material systems that demonstrate tailored deformation behavior regardless of their microscopic and geometric configurations.

Sex differences in cardiac structure and function following ST-segment elevation myocardial infarction

Abstract Post-STEMI cardiac remodelling represents an important determinant of long-term outcomes, yet sex-specific differences in this process remain poorly understood. While disparities between women and men are well-established in the presentation, treatment, and outcomes of both STEMI and heart failure, the extent to which cardiac structure and function evolve differently between the sexes following a myocardial infarction has received limited attention. This study investigated sex-based differences in cardiac remodelling among patients enrolled in the GIPS-III trial, a randomized controlled trial comparing metformin to placebo in STEMI patients without diabetes. Transthoracic echocardiography was performed during the initial hospitalization and repeated at four months, allowing for a detailed assessment of structural and functional changes over time. The analysis included 379 patients, of whom 95 were women and 284 were men. Women presented with a higher prevalence of hypertension, lower hemoglobin levels, and markedly elevated NT-proBNP concentrations both on admission and at 24 hours. At both time points, women demonstrated smaller left ventricular diameters and volumes, a higher E/e’ ratio, and a greater left ventricular ejection fraction compared to men. Despite these baseline differences, the trajectories of echocardiographic parameters over time did not differ meaningfully between sexes. Adverse left ventricular remodelling, defined as a 20% or greater increase in left ventricular end-diastolic volume, occurred at comparable rates in women and men. Left ventricular geometry at four months, encompassing normal geometry, concentric or eccentric hypertrophy, and concentric remodelling, was similarly distributed across sexes. These findings suggest that while women and men differ in their baseline cardiac characteristics following STEMI, the underlying remodelling process appears to follow a broadly similar course, which has relevant implications for how post-STEMI monitoring and management strategies might be applied across sexes.

The Silent Expansion of Fire Activity in Continental Tropical Asia shaped by natural and anthropogenic forces

Discovering a low-dimensional temperature control architecture across animals

Abstract Hibernation is an adaptation to extreme environmental seasonality that has been studied for almost 200 years, but our understanding of the underlying physiological system remains lacking due to the partially observed nature of the system. During hibernation, small mammals, such as the Arctic ground squirrel, exhibit dramatic oscillations in body temperature, typically one of the only physiological states measured, of up to 40 $$\vphantom{0}^{\circ }$$ C. These spikes are known as interbout arousals and typically occur 10–20 times throughout hibernation. The physiological process that drives interbout arousals is unknown, but two distinct macro-scale mechanisms have been hypothesized. Using model selection for partially observed systems and classical dynamical systems theory, we are able to differentiate between these two hypotheses using only body temperature data recorded from a free-ranging Arctic ground squirrel, and show that our model can capture the broad features of the observed seasonal physiological transitions. We then modify our discovered physiological model to include internally encoded environmental information and find that we can qualitatively match body temperature data recorded from a wide range of species, including a bird, a shrew, and a bear, which also dynamically modulate body temperature. Our results suggest that a low-dimensional, environmentally sensitive core regulator could control body temperature across a diverse range of species—a new understanding of the physiological organization across species. While the findings presented here are applicable to thermophysiology, the general modeling procedure is applicable to time series data collected from partially observed biological, chemical, physical, mechanical, and cosmic systems for which the goal is to elucidate the underlying mechanism or control structure.

Modelling impacts of paediatric amoxicillin shortage management on pneumococcal resistance and invasive disease in Europe

Abstract Antibiotic shortages are increasing worldwide. Their impact on individual health and bacterial ecology is unknown, but it could be significant, and there is a lack of epidemiological evidence. Here, we assess the impact of beta-lactam shortage management on pneumococcal resistance and the incidence of invasive pneumococcal disease (IPD). We developed a mechanistic model of S. pneumoniae paediatric colonization and transmission, accounting for beta-lactam and macrolide exposure. We explored the effects of four antibiotic allocation strategies following a one-year beta-lactam shortage: lowering consumption frequency, shortening treatment duration, reducing the daily dose, or substituting beta-lactams with macrolides. These strategies were analyzed in different European pharmaco-epidemiological settings. We found heterogeneous impacts of allocation strategies, amplified at high shortage intensity. The adverse outcomes of shortages increased with baseline antibiotic consumption and the main determinants of the optimal strategy were the initial prevalence of resistance. Reducing beta-lactam frequency most effectively limited resistance, lowering penicillin-non-susceptible and multidrug-resistant strains by up to 21% in Spain during a 50% shortage. The optimal strategy for minimizing IPD incidence was country-dependent: either lowering the daily dose or beta-lactam-to-macrolide substitution. However, the latter significantly increased macrolide resistance, reaching up to 26.2% in Denmark, for a 50% shortage. Our results show that public health priorities and country-specific pharmaco-epidemiological factors should guide antibiotic management strategies during antimicrobial shortages.

Occupational heat risk perceptions and behavioral adaptation strategies among construction and welding workers in Bangladesh

Gene-gene interactions between a LMNA variant and common polymorphisms drive early-onset atrial fibrillation

Abstract Atrial fibrillation (AF), the most common sustained arrhythmia, has a complex genetic basis; however, the molecular mechanisms linking rare and common variants remain poorly understood. Polygenic risk score (PRS) analysis in the UK Biobank and All of Us cohorts reveals that carriers of protein-altering LMNA variants (PAVs) have a significantly higher risk of incident AF than predicted by PRS alone, supporting an additive effect of common polymorphisms and LMNA variants. Induced pluripotent stem cell derived atrial cardiomyocytes (iPSC-aCMs) from individuals carrying the pathogenic missense variant p.S143P in LMNA exhibit widespread disruption of chromatin architecture and perturbation of atrial gene regulatory networks, particularly at loci harboring AF-associated variants and transcription factors essential for atrial rhythm control and contractility. Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-based epigenetic editing validates the function of several AF-associated regulatory elements and their downstream targets. Notably, reduced accessibility at an intronic SCN10A enhancer harboring the AF-associated SNP rs6801957 is associated with reduced sodium current in p.S143P iPSC-aCMs. These findings are reproduced in iPSC-aCMs derived from an additional individual carrying a distinct pathogenic LMNA variant, supporting a broader mechanism in which rare LMNA variants and common polymorphisms converge on shared regulatory networks to influence AF susceptibility and highlighting the value of integrating both in arrhythmia risk assessment.

A hierarchical framework for cropland and crop classification in the Qingtongxia irrigation district using support vector machine and random forest models

Decoding coral resistance to eutrophication through the association of hyper‑efficient denitrifiers as key microbial allies

Abstract Coral reefs face a perilous future due to global climate change compounded by the increasing prevalence of local stressors. Prominent among these is nutrient pollution, particularly nitrate eutrophication, which disrupts the coral-algal symbiosis and escalates reef degradation. While microbial denitrification is hypothesized to mitigate nitrate stress, the mechanisms underlying coral resilience remain unknown. Studying Hong Kong’s coral “reef oases” that persist under chronic hyper-eutrophication, we discovered that resilience is not mediated by diversity or abundance shifts in denitrifier genera but by the association with specific, hyper-efficient denitrifying populations within the dominant denitrifier genus Ruegeria . By integrating population genomics, subspecies-resolution metabarcoding (resolving both the entire Ruegeria community and the denitrifying sub-community), and direct isotope-based activity assays, we identified and validated putative denitrifying “specialist” populations. These specialists were significantly enriched in corals from high-nitrate waters and exhibited 10-fold higher denitrification rates in low-oxygen incubations, converting nitrate to inert N 2 with superior efficiency compared to non-specialists. Our findings reveal that critical ecosystem-scale adaptations to anthropogenic change can occur through a unique association with specialized sub-genus populations, which may be missed in conventional microbiome surveys. As such, our work sheds light into why dominant denitrifying genera are ubiquitous, yet only certain corals thrive in eutrophic conditions. It also provides a framework for future studies delineating ecologically important host-associated microbes.

Energy-efficient information processing and eligibility-trace plasticity in the Drosophila optic lobe connectome

Distinct phosphorylation mechanisms as dynamic switches for Hsp90 regulation

Interpretable machine learning for predicting school absenteeism at-scale in Brazil: evidence from 22,000 schools

Pyridium-π interaction preserves N,S-benzylidene thioacetals in acidolysis enabling efficient protein chemical synthesis

Antiparasitic activity and molecular docking of canthin-6-one derivatives from LED- modulated Eurycoma longifolia roots against Blastocystis ST3 and ST7

Addressing global hotspots of drought-related crop production losses

Abstract Meeting future food demand requires transforming food systems to simultaneously increase production, reduce environmental impacts, and adapt to climate change. As climate variability increasingly affects production stability, understanding where cropping patterns are vulnerable to hydroclimatic stress is a missing but critical step toward improving agricultural production resilience. Here we combine gridded climate data, spatially explicit agricultural statistics, and empirical water-production functions to quantify global patterns of rainfed and irrigated crop-specific Drought Sensitivity-defined as the percent reduction in median yield under extreme hydroclimatic conditions—and drought-associated losses for 17 major crops, representing 75% of global production. This metric identifies locations where crops experience high climate variability and are most susceptible to drought-related losses. We estimate global losses of  − 10.1% and  − 6.8% in median rainfed and irrigated production, respectively, under historically observed extremes—enough calories to feed 2.1 billion people—and identify hotspots in the central US, eastern Brazil, the Mediterranean, and South Asia. Focusing on monsoon cereals (rice, maize, millet, sorghum), we show that sustainable irrigation expansion and targeted crop switching could avoid 62% of rainfed losses while increasing median production by 14%. This scalable framework enables proactive targeting of mitigation actions and investments to stabilize and increase global crop supply.

Designing a multi-epitope subunit vaccine against chikungunya virus using immunoinformatics and molecular simulation approaches

Engineering yeast chromosomal telomeres with a bacteriophage system