Search Results (449)

Anthropogenic disturbance alters macro- and microclimatic conditions, often increasing ambient temperatures. These changes can strongly affect insects, particularly those experiencing high thermal stress (i.e., large differences between body and environmental temperature), as prolonged exposure to elevated temperatures can reduce their energetic reserves due to increased metabolic demands and physiological stress. We evaluated thermal stress in 16 insect dragonfly species during two sampling periods (2019 and 2022) in preserved and disturbed sites within a tropical dry forest in western Mexico. Also, we compared energetic condition (lipid and protein content) and thoracic mass for the seven most abundant species between both habitat types. In preserved sites, insects showed higher thermal stress at lower maximum temperatures, which decreased as temperatures increased. Dragonflies in disturbed sites maintained consistent levels of thermal stress across the temperature gradient. Thermal stress was linked to lower lipid and protein content, and individuals from disturbed sites had reduced energy reserves. We also found a weak but consistent positive relationship between mean ambient temperature and protein content. In preserved sites, thoracic mass increased with thermal stress, but only at high mean temperatures. These findings suggest that although species can persist in disturbed environments, their energetic condition may be compromised, potentially affecting their performance and fitness. Preserving suitable habitats is essential for preserving both biodiversity and ecological function. Full article

The Inner Mongolia Plateau (IMP), situated in the arid and semi-arid ecological transition zone of northern China, is particularly vulnerable to both climate change and human activities. Understanding the spatiotemporal vegetation dynamics and their driving forces is essential for regional ecological management. This study employs Sen’s slope estimation, BFAST analysis, residual trend method and Geodetector to analyze the spatial patterns of Normalized Difference Vegetation Index (NDVI) variability and distinguish between climatic and anthropogenic influences. Key findings include the following: (1) From 1982 to 2022, vegetation cover across the IMP exhibited a significant greening trend. Zonal analysis showed that this spatial heterogeneity was strongly regulated by regional hydrothermal conditions, with varied responses across land cover types and pronounced recovery observed in high-altitude areas. (2) In the western arid regions, vegetation trends were unstable, often marked by interruptions and reversals, contrasting with the sustained greening observed in the eastern zones. (3) Vegetation growth was primarily temperature-driven in the eastern forested areas, precipitation-driven in the central grasslands, and severely limited in the western deserts due to warming-induced drought. (4) Human activities exerted dual effects: significant positive residual trends were observed in the Hetao Plain and southern Horqin Sandy Land, while widespread negative residuals emerged across the southern deserts and central grasslands. (5) Vegetation change was driven by climate and human factors, with recovery mainly due to climate improvement and degradation linked to their combined impact. These findings highlight the interactive mechanisms of climate change and human disturbance in regulating terrestrial vegetation dynamics, offering insights for sustainable development and ecosystem education in climate-sensitive systems. Full article

Hydrogen is being increasingly integrated into the international trade system as a clean and flexible energy carrier, motivated by the global energy transition and carbon neutrality objectives. The rapid expansion of the global hydrogen trade network has simultaneously exposed several sustainability challenges, including a centralized structure, overdependence on key countries, and limited resilience to external disruptions. Based on this, we develop a risk propagation model that incorporates the absorption capacity of nodes to simulate the propagation of supply shortage risks within the global hydrogen trade network. Furthermore, we propose a composite sustainability index constructed from structural, economic, and environmental resilience indicators, enabling a systematic assessment of the network’s sustainable development capacity under external shock scenarios. Findings indicate the following: (1) The global hydrogen trade network is undergoing a structural shift from a Western Europe-dominated unipolar configuration to a more polycentric pattern. Countries such as China and Singapore are emerging as key hubs linking Eurasian regions, with trade relationships among nations becoming increasingly dense and diversified. (2) Although supply shortage shocks trigger structural disturbances, economic losses, and risks of carbon rebound, their impacts are largely concentrated in a limited number of hub countries, with relatively limited disruption to the overall sustainability of the system. (3) Countries exhibit significant heterogeneity in structural, economic, and environmental resilience. Risk propagation demonstrates an uneven pattern characterized by hub-induced disruptions, chain-like transmission, and localized clustering. Accordingly, policy recommendations are proposed, including the establishment of a polycentric coordination mechanism, the enhancement of regional emergency coordination mechanisms, and the advancement of differentiated capacity-building efforts. Full article

A high-fat diet (HFD) has significant effects on health, leading to cardiovascular, metabolic, neurodegenerative, and psychiatric conditions and contributing to obesity and type 2 diabetes. Mitochondria, essential for energy production and oxidative metabolism, are adversely affected by a HFD, causing oxidative stress and impaired cellular function. Mutations in the OPA1 (OPtic Atrophy 1) gene, crucial for mitochondrial dynamics and functions, are responsible for dominant optic atrophy (DOA), a mitochondrial neurodegenerative disease associated with increased reactive oxygen species (ROS). The expressivity of DOA is highly variable, even within the same family. This suggests that both modifying genetics and environmental factors could influence the penetrance of the disease. We previously demonstrated that genetic background modulates DOA expressivity and now ask if this is also the case for external cues. We thus explore how OPA1 deficiency interacts with HFD-induced metabolic disturbances, hypothesizing that long-term HFD consumption impairs brain mitochondrial function and disrupts oxidative metabolism. OPA1^+/− mice were thus subjected to a HFD for a period of 12 weeks, and ROS levels and the expression of antioxidant genes were evaluated by Western blot and spectrophotometry. Cortices from high-fat diet-fed OPA1^+/− mice showed lower aconitase activity than those of their wild-type (WT) litter mates, indicative of an unbalanced increase in mitochondrial ROS. Accordingly, OPA1^+/− mice present lower levels of the antioxidant enzyme superoxide dismutase 2 compared to WT mice. Therefore, this study (i) reveals the onset of oxidative stress in brain cortices from OPA1^+/− mice challenged with a HFD, (ii) shows that diet is a modifying factor for DOA, and (iii) suggests that food control could be used to moderate the severity of the disease. Full article

Temporal lobe epilepsy (TLE) is a common drug-resistant form of epilepsy, often accompanied by cognitive and emotional disturbances, highlighting the urgent need for novel therapies. Scorpion Venom Heat-Resistant Synthetic Peptide (SVHRSP), isolated and synthetically derived from scorpion venom, has shown anti-epileptic and neuroprotective potential. This study evaluated the anti-epileptic effects of SVHRSP in a kainic acid (KA)-induced TLE rat model. Our results demonstrated that SVHRSP (0.81 mg/kg/day) reduced the frequency and severity of spontaneous seizures. Behavioral tests showed improved cognitive performance in the novel object recognition, object location, and T-maze tasks, as well as reduced anxiety-like behavior in the open-field test. Moreover, SVHRSP mitigated hippocampal neuronal loss and glial activation. Transcriptomic analysis indicated that SVHRSP upregulates genes involved in adhesion molecule-triggered and axon guidance pathways. Western blotting and immunofluorescence further confirmed that SVHRSP restored dendritic (MAP2), axonal (NFL), and synaptic (PSD95) marker expression, elevated the functionally important L1CAM fragment (L1-70), and increased myelin basic protein-induced serine protease activity responsible for L1-70 generation. Blockade of L1CAM expression diminished the neuroprotective effects of SVHRSP, suggesting a critical role for L1CAM-mediated synapse functions. This study is the first to reveal the therapeutic potential of SVHRSP in TLE via L1CAM-associated mechanisms. Full article

Megafires are transforming western boreal forests, and many burned forests are salvage logged, removing more structure from landscapes and delaying forest regeneration. We studied forest-dwelling owls in a post-fire and salvage-logged landscape in central British Columbia, Canada, in 2018–2019 after the 2010 Meldrum Creek Fire and the 2017 Hanceville Fire. We examined owl habitat selection via call surveys compared to the habitats available in this landscape. Owl pellets were dissected to determine owl diets. We detected six owl species, of which Northern Saw-whet Owls (Aegolius acadicus) were the most common. Owls had weak and variable habitat selection within an 800 m radius of detections; all species used some burned area. Great Gray Owls (Strix nebulosa) and Great Horned Owls (Bubo virginanus) obtained more prey from mature forests (e.g., red-backed voles, Myodes gapperi, snowshoe hares, Lepus americanus) than other owls did, whereas other owls primarily consumed small mammals that were common in burned or salvaged areas. These results indicate a diverse community of owls can use landscapes within a decade after wildfire, potentially with some prey switching to take advantage of prey that use disturbed habitats. Despite that, owl numbers were low and some owls consumed prey that were not available in salvage-logged areas, suggesting that impacts on owls were more severe from the combination of fire and salvage logging than from fire alone. Full article

Jilin Province is an important ecological security barrier and major grain-producing region in northeast China, playing a crucial role in ensuring ecological security and promoting regional sustainable development. This study examines ecological resilience from three dimensions: resistance, adaptability, and resilience. Based on multi-source data from 2000 to 2020, an ecological resilience indicator system was constructed. Spatial autocorrelation and OPGD models were employed to analyze temporal and spatial evolution and the driving mechanisms. The results indicate that ER exhibits an overall spatial pattern of “high in the east, low in the west, and under pressure in the central region.” The eastern mountainous areas demonstrate high and stable resilience, while the central plains and western ecologically fragile regions exhibit weaker resilience. In terms of resistance, the eastern mountainous regions are primarily forested, with high and sustained ESV, while the western sandy edge regions primarily have low ESV, making ecosystems susceptible to disturbance. In terms of adaptability, the large-scale farmland landscapes in the central regions exhibit strong disturbance resistance, while water resource adaptability in the western ecologically fragile regions has locally improved. However, adaptability in the eastern mountainous regions is relatively low due to development impacts. In terms of resilience, the eastern core regions possess stable recovery capabilities, while the central and western regions generally exhibit lower resistance with fluctuating changes. Between 2000 and 2020, the ecological resilience Moran’s I index slightly decreased from 0.558 to 0.554, with the spatial aggregation pattern remaining largely stable. Among the driving factors, DEM remains the most stable. The influence of NDVI has weakened, while temperature (TEM) and NPP-VIIRS have become more significant. Overall, factor interactions have grown stronger, as reflected by the q-value rising from 0.507 to 0.5605. This study provides theoretical support and decision-making references for enhancing regional ecological resilience, optimizing ecological spatial layout, and promoting sustainable ecosystem management. Full article

The intensive utilization of agricultural inputs is key to agricultural modernization. This study analyzed the elasticity of substitution among inputs in Chinese grain production (1991–2023) using a Translog production function, controlling for price disturbances. The key findings are as follows: (1) Complementary relationships exist between capital–fertilizer, capital–land, fertilizer–land, pesticide–land, and fertilizer–labor, while capital–pesticide, fertilizer–pesticide, pesticide–labor, and land–labor are substitutive. (2) The elasticity of substitution among agricultural inputs stabilizes over time, with substitutive and complementary relationships among most factors weakening after 2004. (3) Eastern and northeastern regions tend to substitute labor with capital more significantly, while central and western regions show a balanced interplay. (4) Nationwide trends in agricultural input shares indicate increasing mechanization, land-use efficiency, fertilizer use, and reduced labor input. These results provide insights for optimizing input allocation and enhancing food security. Full article

Polylepis woodlands, endemic to the Andean Mountains, are critical for biodiversity and ecosystem services but face threats from anthropogenic disturbances and climate change. This study employed sonic tomography (ST) to assess the structural integrity of three relict Polylepis stands on the western slopes of the Peruvian Andes. A total of 192 tomograms from 48 trees across three sites revealed substantial variation in internal decay (2.5–70%), with mean decay levels of 11.6% (Z1), 16.6% (Z2), and 10.5% (Z3). Although the initial generalized linear mixed models (GLMMs) suggested tree diameters at breast height (DBH) as a potential predictor of decay, subsequent non-parametric Spearman’s correlation analysis found no significant relationship between DBH and decay (r < 0.001, p > 0.05) or between altitude and decay (r = 0.187, p = 0.204). No significant differences were detected among species or zones. The study demonstrates the efficacy of ST for noninvasive health assessment in high-altitude ecosystems and underscores the need for long-term monitoring to guide conservation strategies. Full article

Hedgehog (HH) signaling plays important roles in the development of the nervous system (Sonic hedgehog), bone, cartilage (Indian Hedgehog) and testis (Desert Hedgehog). Research on HH and testes has mostly been conducted in HH-knockout mice and rats, etc. The relationship between HH and cellular junctions has mostly been found in the nervous system and intestine. However, few research studies concerning the link between HH signaling and cell junctions in testis function have been reported. We identified the members of HH signaling that are involved in Eriocheir sinensis testes: HH, Smoothen, Patched, Kif27 and Ci. HH has only one homolog in E. sinensis and is expressed in several types of germ cells in the testes. We found that Kif27 colocalized with Ci in the testes. The knockdown of HH induced enlarged interstitial spaces of the seminiferous tubules. A biotin–streptavidin immunofluorescence experiment indicated that the hemolymph–testis barrier (HTB) was disrupted. Western blot results showed that pinin, HH signaling and cell proliferation- and apoptosis-related protein levels were downregulated. Further immunofluorescent results showed the dislocation of several junction proteins, the abnormality of F-actin and the slowdown of germ cell proliferation and apoptosis. While β-catenin entered the spermatocyte nucleus, it did not activate Wnt-β-catenin signaling, which indicated that the disturbance of the cell cycle in germ cells was not caused by Wnt-β-catenin signaling. In summary, HH signaling plays some roles beyond our understanding in the regulation of the HTB and the germ cell cycle in E. sinensis testes. Full article

With the intensification of global climate change and human activities, coniferous species as the main components of natural forests in the Altay Mountains are facing the challenges of aging and regeneration. This study systematically analyzed structural heterogeneity and regeneration of three coniferous stand groups, Larix sibirica Ledeb. stand group, Abies sibirica Ledeb.-Picea obovata Ledeb.-Larix sibirica mixed stand group, and Picea obovata stand group, respectively, across western, central, and eastern forest areas of the Altay Mountains in Northwest China based on field surveys in 2023. Methodologically, we integrated Kruskal–Wallis/Dunn’s post hoc tests, nonlinear power-law modeling (diameter at breast height (DBH)–age relationships, validated via R², root mean square error (RMSE), and F-tests), static life tables (age class mortality and survival curves), and dynamic indices. Key findings revealed structural divergence: the L. sibirica stand group exhibited dominance of large-diameter trees (>30 cm DBH) with sparse seedlings/saplings and limited regeneration; the mixed stand group was dominated by small DBH individuals (<10 cm), showing young age structures and vigorous regeneration; while the P. obovata stand group displayed uniform DBH/height distributions and slow regeneration capacity. Radial growth rates differed significantly—highest in the mixed stand group (average of 0.315 cm/a), intermediate in the P. obovata stand group (0.216 cm/a), and lowest in the L. sibirica stand group (0.180 cm/a). Age–density trends varied among stand groups: unimodal in the L. sibirica and P. obovata stand groups while declining in the mixed stand group. All stand groups followed a Deevey-II survival curve (constant mortality across ages). The mixed stand group showed the highest growth potential but maximum disturbance risk, the L. sibirica stand group exhibited complex variation with lowest risk probability, while the P. obovata stand group had weaker adaptive capacity. These results underscore the need for differentiated management: promoting L. sibirica regeneration via gap-based interventions, enhancing disturbance resistance in the mixed stand group through structural diversification, and prioritizing P. obovata conservation to maintain ecosystem stability. This multi-method framework bridges stand-scale heterogeneity with demographic mechanisms, offering actionable insights for climate-resilient forestry. Full article

High-altitude environments pose significant risks for insomnia development, which severely compromises both physiological health and occupational performance. To elucidate the mechanisms underlying altitude-induced sleep disruption and establish a validated animal model for therapeutic intervention development, we exposed Sprague-Dawley rats to hypobaric hypoxia (5500 m altitude equivalent: 308 mmHg, 20.37% O₂, PiO₂ 8.0 kPa) for 7 days. We employed continuous wireless telemetry to monitor EEG/EMG signals, with concurrent analysis of physiological parameters, blood biochemistry, histopathology, transcriptomics, and protein expression. Quantitative analyses demonstrated decreased caloric intake, transient body mass reduction, and immune-metabolic disturbances. While total sleep duration showed no significant variation, sleep architecture displayed elevated wakefulness periods, reduced active wakefulness, a decreasing trend of slow-wave sleep (SWS), and increased paradoxical sleep (PS) accompanied by attenuated circadian oscillations. The duration of SWS episodes was significantly shortened, indicating a sleep homeostasis imbalance that peaked on day 3. Biochemical profiling revealed reduced levels of antioxidant enzymes, elevated pro-inflammatory cytokines, and hypothalamic–pituitary–adrenal axis activation. Transcriptomic analyses identified the critical involvement of serotonergic/glutamatergic synaptic regulation, lipid metabolism, IL-17 signaling, and cortisol synthesis pathways. Western blot analyses confirmed OX2R upregulation, 5-HT1AR downregulation, and circadian gene dysregulation. Our findings demonstrate that hypobaric hypoxia induces sleep disruption via coordinated mechanisms involving oxidative stress, inflammatory activation, HPA axis hyperactivity, neurotransmitter imbalance, and circadian clock dysfunction, providing a robust preclinical model for mechanistic exploration and therapeutic target identification. Full article

Wildfire is a critical driver of ecological processes in western U.S. forests, but recent shifts in climate, land use, and fire suppression have altered forest structure and disturbance regimes. Understanding post-fire recovery is essential for land management, particularly across complex montane landscapes like the southern Rocky Mountains. We assessed forest recovery in montane conifer forests, ranging from ponderosa pine to spruce-fir, following a large mixed-severity fire using field-based forest stand data and remotely sensed Leaf Area Index (LAI) measurements. Our objectives were to determine whether LAI is a meaningful proxy for post-fire vegetative recovery and how recovery patterns vary by forest type, burn severity, and abiotic factors. Stand characteristics predicted crown burn severity inconsistently and did not predict soil burn severity. LAI correlated strongly with live overstory tree density and shrub cover (R² = 0.70). Recovery trajectories varied by forest type, with lower-severity burns generally recovering four years post-fire, while high-severity burns showed delayed recovery. Regeneration patterns were strongly influenced by climate, with higher seedling densities occurring at wetter sites. Our findings highlight the utility of LAI as a proxy for vegetative recovery and underscore the importance of forest type, fire severity, and climatic factors when assessing post-fire resilience. Full article

Biochemical alterations linked to metabolic syndrome (MetS), type 2 diabetes (T2DM), and metabolic dysfunction-associated steatotic liver disease (MASLD) may be brought on by the Western diet. Based on research conducted over the past decade, fructose is one of the main culprits. Over 80% of ingested fructose is metabolized by the liver at first pass, where it stimulates de novo lipogenesis (DNL) to drive hepatic triglyceride (TG) synthesis, which contributes to MASLD, hepatic insulin resistance (IR), and dyslipidemia. Fructose reduction produces quick and significant amelioration in these metabolic disturbances. We hereby propose potential overarching processes that can link these pathways to signaling disruption by the critical metabolic sensor AMP-activated protein kinase (AMPK). We proffer that when large amounts of fructose and glucose enter the liver, triose fluxes may be sufficient to produce transient increases in methylglyoxal (MG), allowing steady-state concentrations between its production and catabolism by glyoxalases to be high enough to modify AMPK-sensitive functional amino acid residues. These reactions would transiently interfere with AMPK activation by both AMP and aldolase. Such a sequence of events would boost the well-documented lipogenic impact of fructose. Given that MG adducts are irreversible, modified AMPK molecules would be less effective in metabolite sensing until they were replaced by synthesis. If proven, this mechanism provides another avenue of possibilities to tackle the problem of fructose in our diet. We additionally discuss potential multimodal treatments and future research avenues for this apparent hepatic AMPK malfunction. Full article

Background: Coix seed oil (YRO), rich in unsaturated fatty acids, has emerged as a promising intervention for hyperuricemia (HUA) due to its potential to alleviate oxidative damage and support organ health. Methods: The fatty acid composition of YRO was determined by gas chromatography–mass spectrometry (GC-MS). A HUA mouse model was established, and serum markers and hepatic enzymes were evaluated. Renal mitochondrial function was assessed using immunohistochemistry and immunofluorescence, and urate transporter expression, along with key signaling proteins, was quantified by Western blot analysis. Additionally, gut microbiota composition was analyzed, and non-targeted metabolomics was performed to observe alterations in serum lipid metabolites. Results: YRO significantly reduced serum uric acid (UA) levels and normalized hepatic enzyme activities. Histological evaluation revealed less tissue damage in both the kidney and the intestine. In the kidney, YRO improved mitochondrial function and supported antioxidant defenses via regulation of Keap1/Nrf2 signaling. In the intestine, YRO enhanced barrier integrity by increasing ZO-1, Occludin, and Claudin-1 expression. Moreover, YRO modulated gut microbiota by increasing beneficial bacteria (Muribaculaceae, Prevotellaceae UCG-001, Lachnospiraceae_ NK4A136_group, Akkermansia) while suppressing harmful species (Bacteroides, Dubosiella). Lipid metabolomics indicated a restoration of phospholipid balance through modulation of the PI3K/AKT/mTOR pathway. Conclusions: YRO supported metabolic health by promoting UA homeostasis, enhancing mitochondrial function, reinforcing antioxidant capacity, and maintaining gut integrity. These findings suggest that coix seed oil could serve as a nutritional supplement in managing HUA and related metabolic disturbances. Full article