Search Results (536)

The degradation of Calcisols in the arid regions of Central Asia constrains sustainable agricultural production because of low organic matter content, poor aggregate stability, nutrient limitations, and increasing climatic stress. This study evaluated a rhizosphere engineering approach based on the native plant growth-promoting bacterium Pseudomonas veronii Ps-S/Sh-1503/2022 for the rehabilitation of degraded Calcisols. Four-year field experiments (2022–2025) using Sorghum bicolor assessed plant growth, rhizosphere microbial indicators, physiological responses, pathogen suppression, crop productivity, and implementation feasibility through economic and environmental assessments. Inoculation with P. veronii increased root depth by 45%, improved aboveground biomass, increased the ratio of culturable bacteria to Fusarium spp. from 6.1 to 10.3, and reduced Fusarium abundance by 29.4%. Structural equation modeling suggested that trophic support (42.1%), aggregate stabilization (27.4%), biocontrol (23.3%), and defense-related responses (7.2%) were the principal pathways associated with soil rehabilitation. Economic assessment indicated that the combined inoculation and mineral fertilization treatment provided the highest profitability, while environmental assessment estimated potential reductions in mineral fertilizer use and greenhouse gas emissions. These findings suggest that rhizosphere engineering using a native P. veronii strain represents a promising, economically viable, and climate-smart approach for improving the biological functioning of degraded Calcisols and supporting sustainable agricultural production. Full article

Understanding how animals operationally identify and exploit resource patches is central to foraging ecology. The “patch”—a discrete area of resource concentration—is the fundamental unit of individual foraging behavior; however, standardized operational definitions of the criteria for patch identification across taxa, habitats, and biomes are still scarce. Following PRISMA 2020 guidelines, we reviewed 87 empirical studies encompassing 133 species, classifying patch identification methods across eight macro-categories of the European Nature Information System (EUNIS)—a structurally detailed habitat classification that, despite its European origin, we apply here as a general structural template for habitat architecture rather than as a claim of biogeographic universality, given that our dataset also spans non-European taxa and biomes. Patches are operationally identified through two approaches: observational delineation of natural resource structures (e.g., fruiting trees, prey aggregations, vegetation clusters) and experimental manipulation via artificial depletable units. We demonstrate that habitat structural complexity and species trophic preferences jointly govern the operational method by which patches are identified: habitat architecture determines which operational approach is used for patch delineation—observational or experimental—while a four-category Feeding Guild classification (Granivore, Herbivore, Omnivore, Carnivore) reveals that resource discretizability—the capacity to standardize prey into countable, depletable units—operates as the primary species-level predictor of patch identification method selection, an association that remains robust after formally controlling for phylogenetic non-independence and body mass in a mixed-effects model. The resulting framework provides, for the first time, a standardized operational guide for calibrating patch identification methods to habitat type and species trophic preferences and searching behavior across taxa and biomes. Full article

Background: Advances in neonatal intensive care have improved survival in congenital diaphragmatic hernia (CDH), shifting the clinical focus toward long-term complications such as feeding difficulties. Initiation of enteral feeding varies across centers, with evidence suggesting that intra-abdominal pressure (IAP) may influence time to feeding and clinical decision-making. We explored associations of early postoperative heart rate (HR), recorded Apgar score, and intra-abdominal pressure (IAP) with time to enteral trophic feeding. Methods: We retrospectively evaluated 28 consecutive neonates undergoing CDH repair at a national referral center between January 2022 and June 2025. Trophic enteral feeding (≥10 mL/kg/day for ≥24 h) was the primary endpoint. Aalen–Johansen estimates and two parsimonious Fine–Gray models (HR plus Apgar; IAP plus Apgar) were primary analyses and cause-specific Cox models were sensitivity analyses. Results: Within 30 postoperative days, trophic enteral feeding was achieved in 21 cases, six patients died before feeding, and one did not achieve feeding before censoring. Each 10 bpm higher HR was associated with lower feeding incidence (subdistribution HR 0.62, 0.46–0.85; p = 0.003); the cause-specific point estimate was also below 1 (HR 0.65, 0.47–0.89; p = 0.007). Mean IAP was not clearly associated with feeding incidence (subdistribution HR 1.01 per mmHg, 0.82–1.25; p = 0.925). Both Cox models failed global proportional-hazards tests. Conclusions: Each 10 bpm increase in HR was associated with a longer time to trophic enteral feeding, and the cause-specific sensitivity analysis pointed in the same direction. Because both estimates derive from the same 28 infants, their agreement is expected rather than corroborative. These findings are exploratory and do not establish causality, individual predictive value, or superiority of HR over IAP. Prospective multicenter studies with adequate sample sizes are needed to confirm these findings. Full article

Dam removal is a direct measure to restore river connectivity, but the assessment of its ecological effects has long been constrained by the lack of continuous monitoring data across multiple trophic levels. Based on eight years (2017–2024) of continuous field monitoring data from the Heishui River, a first-order tributary of the Jinsha River, this study systematically analyzed the spatiotemporal dynamics of phytoplankton, zooplankton, and fish communities before and after the removal of the Laomuhe Dam. Ecopath models were constructed annually for six ecological units to quantitatively assess the restructuring effect of dam removal on the structure and function of the aquatic food web. The results showed that: (1) Plankton communities were highly sensitive to the disturbance of dam removal. In the early stage after dam removal (2019), the diversity of phytoplankton and zooplankton across the whole river suffered a cliff-like decline; the Shannon index of zooplankton in the former reservoir area plummeted from 3.06 to 0.81. During the recovery period, diatoms and rotifers acted as pioneer groups for phytoplankton and zooplankton, respectively, and were the first to recover. By 2024, the proportion of copepods rose to the highest level during the study period, and the dominant group of the community shifted from rotifers to copepods. (2) Fish communities responded rapidly and positively to the restoration of connectivity. In the upstream reach adjacent to the dam site, the number of species increased from 3 before dam removal to 12 afterward; in the downstream reach, it increased from 2 to 15, with diversity index increases of 172% and 246%, respectively. (3) Ecopath model analysis revealed a recovery pattern of “structure first, function delayed” in the food web—species number and community composition could be re-established shortly after connectivity restoration, but the recovery of functional indicators such as the system omnivory index (SOI) and energy transfer efficiency (total primary production/total respiration, TPP/TR) lagged significantly behind. By the end of the study period, the upstream dewatered reach had not yet reached the level of the natural reference reach, and the downstream recovery rate and degree were better than those upstream. This study provides comprehensive time-series evidence for the long-term response of aquatic ecosystems to low-head dam removal and offers valuable references for guiding adaptive management of mountain rivers after dam removal. Full article

In this paper, a delayed fractional-order three-trophic-level food chain model with Allee effect and prey shelter is proposed and analyzed. The model adopts the Caputo fractional derivative to describe the memory effect, and introduces two discrete time delays which represent the gestation and response delays of predators, respectively. We establish the positivity, boundedness, existence, uniqueness and continuity of solutions. By using Jacobian matrix analysis and fractional stability theory, we investigate the equilibrium points and their local stability. The corrected characteristic equation is derived, and sufficient conditions for a Hopf-type stability switch induced by the delays are obtained. In the integer-order case $\alpha =1$, the critical delay and transversality condition are verified numerically, supporting a classical Hopf-bifurcation conclusion subject to the usual nondegeneracy assumptions. Numerical simulations verify the theoretical results and illustrate the combined effects of time delays, fractional memory, prey shelter and Allee effect on system dynamics. The results show that time delays may destabilize the system and produce persistent oscillatory numerical behaviour, while stronger memory effects, shelter strength and Allee effects enhance system stability and suppress oscillatory behaviors. Full article

Chlorophyll-a is a widely used indicator for assessing the trophic status and water quality of aquatic ecosystems because of its close relationship with phytoplankton biomass. This study aimed to identify the physicochemical, biological, and temporal variables associated with chlorophyll-a concentrations in Lake Gatun during the 2017–2023 period using the Light Gradient Boosting Machine (LightGBM) algorithm and a Generalized Linear Model (GLM). A total of 25 predictor variables describing water quality were analyzed using data collected from 14 monitoring stations distributed throughout Lake Gatun within the Panama Canal watershed. The LightGBM model achieved satisfactory predictive performance, with an RMSE of 4.58, an MAE of 3.26, and a coefficient of determination (R²) of 0.42 on the testing dataset. Variable importance analysis identified turbidity, dissolved oxygen, and water transparency as the most influential predictors of chlorophyll-a concentrations. These findings improve our understanding of the factors associated with chlorophyll-a variability and demonstrate the potential of machine learning models as decision-support tools for monitoring and managing aquatic ecosystems. Full article

We formulate and study a predator–prey model with pursuit-evasion spatial behaviour, incorporating the fear effect in a sexually-reproducing prey population. The pursuit-evasion movements are described as indirect taxis: populations respond to diffusively dispersed and decaying kairomonal cues of their antagonists. The prey-emitted kairomone attracts predators, while the predator-emitted kairomone repels prey and locally reduces prey reproduction rate, mimicking a physiological fear response. To isolate the net effect of predator’s prey-taxis, we assume predator birth/death rates are negligible, implying a constant predator abundance. Linear stability analysis yields a condition for taxis-driven oscillatory instability of the homogeneous steady state. Numerical simulations reveal spatially heterogeneous dynamics, coexistence of periodic travelling waves, and transitions to spatiotemporal chaos. The results highlight interrelations between fear responses, spatial movements, spatiotemporal heterogeneity, and viability of the trophic system. Full article

Copper-based nanopesticides are increasingly explored as nano-enabled alternatives to conventional copper pesticides because they may improve deposition, antimicrobial efficacy, and material-use efficiency. Their environmental risk, however, cannot be inferred from total copper concentration or from the toxicity of pristine particles alone. After agricultural application, copper-based nanoforms may be transported to soils, drainage waters, wetlands, and sediments, where aggregation, dissolution, aging, sulfidation, organic complexation, and biological processing reshape their speciation and bioavailability. This review critically examines copper-based nanopesticides at the benthic interface, with emphasis on environmental transformation, synchrotron-resolved speciation, lower-trophic invertebrate exposure, trophic transfer, and food-web risk. We highlight that sediment-associated organisms are not only toxicity endpoints but also biological processors and vectors of transformed copper species. Evidence from stable-isotope tracing, dietary exposure studies, mesocosms, and micro-food-web experiments shows that copper-based nanoforms can enter aquatic, benthic, and terrestrial food chains. However, most studies demonstrate transfer or accumulation rather than consistent biomagnification across trophic levels. We further argue that future risk assessment should move beyond single-material and single-endpoint testing toward transformation-aware, route-specific, and food-web-relevant frameworks. Integrating total copper analysis with particle-specific measurements, synchrotron-based speciation where analytically feasible, realistic lower-trophic exposure models, and ecosystem-level endpoints will be essential for evaluating the long-term risks of copper-based nanopesticides. Full article

Cardiovascular diseases (CVDs) remain the foremost cause of death globally, responsible for 19.2 million deaths and 437 million disability-adjusted life years in 2023, with prevalent cases having more than doubled since 1990. No approved therapy restores myocardium lost to infarction. The adult heart replaces cardiomyocytes at approximately 1% per year in young adults, declining to about 0.45% per year with ageing, far below what is needed to recover the more than one billion cells destroyed by a large myocardial infarction. Cell-based regenerative strategies have been investigated for more than two decades, encompassing bone marrow mononuclear cells (BM-MNCs), mesenchymal stromal cells (MSCs), cardiac progenitor cells, cardiosphere-derived cells (CDCs), skeletal myoblasts, and induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs). Safety has been consistent. Efficacy has been modest and variable: the CADUCEUS trial demonstrated scar mass reduction with CDCs without proportionate ejection fraction improvement; the Phase 1/2 POSEIDON trial confirmed MSC safety in 30 patients; and the Phase 3 DREAM-HF trial, enrolling 537 patients, failed its primary endpoint (HR 1.2, p = 0.406). Mechanistic work has established that transplanted cells engraft poorly and exert their benefit principally through paracrine signalling mediated by secreted extracellular vesicles and exosomes carrying microRNAs, trophic factors, and immunomodulatory proteins. For iPSC-CMs, electrophysiological immaturity and arrhythmogenic risk in primate models remain unresolved barriers. Emerging strategies include CRISPR-engineered hypoimmune iPSC lines, bioengineered cardiac patches, injectable hydrogel scaffolds, and engineered exosome platforms. This review provides a comprehensive synthesis of preclinical and clinical evidence, examines translational barriers, and identifies the scientific and regulatory priorities required before these therapies can enter routine clinical practice. Full article

Coral reef ecosystems are increasingly threatened by climate change, pollution, and overfishing, causing major declines in marine megafauna and high-trophic-level fishes. Monitoring these species is vital for conservation, yet traditional survey methods are slow and resource intensive. This study presents a semi-automated monitoring pipeline that integrates deep learning (DL) with human-in-the-loop validation to streamline Baited Remote Underwater Video (BRUV) analyses in the Gita Nada Marine Protected Area (MPA), Indonesia. A total of 244 BRUV deployments from SORCE’s long-term monitoring program in the Gita Nada MPA, comprising 328 h of footage, collected 2023–2025 under Indonesian research oversight through Yayasan SORCE Konservasi Indonesia, were processed using a DL workflow. To address long-tailed species distributions, focal taxa were grouped into six Morphological Groups and detected using a YOLOv12x model trained via transfer learning from the Community Fish Detector. A custom temporal-tracking framework extracted ecological metrics including N, Time to First Visit ($T_{1^{st}}$), and Visit Duration ($T_{visit}$). The pipeline achieved moderate to high detection and tracking performance for several Morphological Groups, achieving object detection F1-scores of up to 0.873 and an overall tracker recall and precision of 0.80 and 0.76, respectively, although performance varied substantially among groups and was substantially limited for data-deficient taxa. As a proof-of-concept, we applied the framework to assess ecological shifts in Cheloniidae and Carangidae across coral-cover gradients. Overall, this semi-automated approach reduces BRUV processing effort and provides a scalable foundation for generating the large datasets needed to detect subtle ecological change. Full article

Biogenic volatile organic compounds released from soil (SBVOCs) are an important component of the material exchange and information transmission between terrestrial ecosystems and the atmosphere. Soil ecosystems act as both critical sources and frequently overlooked sinks of BVOCs. SBVOC emissions are mainly regulated by the temperature, moisture, and pH of the soil. Climate warming may enhance volatilization and microbial production in the short term. However, its long-term effects depend on drought, vegetation composition, substrate availability, permafrost thaw, and microbial acclimation. SBVOCs also influence microbial activity, nutrient cycling, plant–microbe interactions, plant defence, and below ground trophic interactions, although the strength of evidence differs among these functions. Ecologically, SBVOCs promote carbon cycling, modulate plant-microbe interactions, and influence atmospheric chemistry. This review further synthesizes SBVOC emission and uptake patterns across different climatic zones. Several challenges remain, particularly the scarcity of long-term quantitative measurements and difficulties in distinguishing multiple emission sources. Our understanding of rhizosphere interactions and climate-change feedback is also limited. It is essential to enhance long-term observational studies and optimize models to deepen our understanding of the role of SBVOCs in the global carbon cycle and air quality. Full article

Research over the last decades have demonstrated that macrophages, considered canonical players of the immune system, also perform many other important biological functions in adult organisms. These properties have stimulated extensive research, particularly given their importance in human pathologies, including cancer. However, despite significant advances in our understanding of macrophage functions in adult organisms and diseases, their roles in embryonic systems remain comparatively underexplored. Owing to their complex developmental origin and the lack of pronounced phenotypes in embryos subjected to either spontaneous or experimentally induced macrophage ablation, macrophages have often been considered as a largely passive scavenger population associated with programmed cell death during organ and tissue remodeling. Here, we highlight key findings regarding macrophage functions during vertebrate morphogenesis. We emphasize the differences in phenotypic outcomes following macrophage ablation in adult organisms, embryos, and models of organ regeneration. Currently, the remarkable plasticity of the macrophage lineage complicates the identification of specific trophic functions involved in organ morphogenesis. Developing new approaches that improve the efficiency of macrophage ablation models, along with implementing complementary gain-of-function strategies, will contribute to a deeper understanding of the role of macrophages during embryonic development. Full article

Coral reefs are typical ecosystems of high diversity and productivity, but they are facing significant degradation in their structure and function due to the dual stresses of climate change and human activities. To uncover the trophic structure, energy flow, and environmental driving mechanisms of nearshore coral reefs in Hainan, this study constructed mass balance models for five regions, Sanya, Changjiang, Lingao, Wenchang, and Wanning, using Ecopath with Ecosim, and conducted quantitative analysis in conjunction with satellite environmental monitoring data. The results showed that the trophic levels of functional groups in different ecosystems ranged from 1.00 to 5.00, with Sanya and Changjiang having the highest trophic levels (4.505, 4.656), higher than Lingao, Wenchang, and Wanning (3.776–3.924). The system average trophic transfer efficiency ranged from 15.98% to 30.25%, generally higher than the classic Lindeman 10% rule, with Changjiang being the highest (30.25%) and Lingao the lowest (15.98%). In terms of material cycling, the energy utilization efficiency of primary trophic levels was low, with a large amount of energy retained as detritus at lower trophic levels; Sanya and Changjiang showed more complete detritus chain energy cycling, with Finn cycling indices reaching 7.69 and 2.53, respectively, indicating higher maturity. Keystone analysis identified zooplankton, corals, and medium carnivorous fish as key functional groups with a decisive impact on system stability. Environmental correlation analysis revealed that particulate inorganic carbon (Pic), light diffuse attenuation coefficient (Kd), chlorophyll-a concentration (Chl_a), and sea surface temperature (Sst) were the main regulating factors, among which Pic showed a significant peaked relationship with the total system throughput, total biomass, and total production, with an optimal range of 0.0050–0.0075 mol/m². Overall, the material cycling and energy flow states of the Sanya and Changjiang coral reef ecosystems were stronger than those of Lingao, Wenchang, and Wanning, with lower fishing pressure in the former contributing to a more complex food web and enhanced community structural stability. This study provides the first systematic quantitative assessment of food-web structures across five distinct nearshore coral reef regions in Hainan, introducing an early-warning threshold for particulate inorganic carbon that offers direct, actionable reference for regional ecosystem-based management. Full article

Long-term changes in land-use and water quality degradation are key pressures on riverine ecosystems, yet their effects on the functional structure of fish assemblages remain insufficiently quantified. We conducted a decadal assessment of fish assemblages in four rivers experiencing rapid land-use transformation in Guangxi, China—the Zuojiang (ZY), Youjiang (YJ), Yujiang (YuJ), and Guijiang (GJ) rivers. Species-level functional traits describing body shape, vertical habitat position, feeding guild, trophic level, and maximum total length were used to calculate multiple functional diversity indices related to environmental variables using redundancy analysis and random forest models. Over the decade from 2013 to 2023, impervious surface and bare land increased significantly, while forest, shrubland, and grassland declined, coinciding with marked deterioration in water quality, including higher chlorophyll-a and lower dissolved oxygen concentrations (p < 0.05). Fish abundance and species richness decreased, and formerly dominant benthic cyprinids and loaches were replaced by tolerant and invasive taxa such as Oreochromis niloticus and Tilapia zillii. NMDS and PERMANOVA indicated a significant shift in community composition between 2013 and 2023 (R² = 0.14, p < 0.001), with fish assemblages shifting toward small-bodied, pelagic, omnivorous, and laterally compressed species. Functional richness declined, whereas functional evenness and functional dispersion increased, indicating functional simplification and homogenization. Multivariate and machine learning models consistently identified increasing impervious cover and declining dissolved oxygen as the strongest predictors of these changes. Our results demonstrate that land-use intensification and water quality deterioration are associated with reduced functional integrity in Guangxi rivers and highlight the value of trait-based indicators for monitoring and managing biodiversity in rapidly urbanizing catchments. Full article

Stable carbon (δ¹³C) and nitrogen (δ¹⁵N) isotope analysis of bone collagen has become a cornerstone method for reconstructing the diets of past populations. This critical review moves beyond the mere presentation of data to examine the theoretical foundations, methodologies, and applications of this approach. The principles of the method are based on isotopic fractionation during photosynthetic pathways (C₃, C₄, and CAM) and the trophic-level enrichment of ¹⁵N, which together enable the differentiation of plant food sources and the identification of consumer trophic position, respectively. The methodology encompasses sampling strategies, challenges posed by diagenesis, collagen extraction protocols, including the Longin method, and quality-control criteria (collagen yield, C:N ratio). Key applications include the reconstruction of baseline diets, the determination of weaning practices, and the identification of social inequalities. However, confounding factors—such as climate-driven variation in baseline nitrogen values, physiological effects (disease, lactation), and the consequences of human activities (manuring)—can complicate interpretation. Future directions include compound-specific amino acid analysis, multi-isotope approaches, and Bayesian modelling. In conclusion, isotopic data require a contextual and interdisciplinary approach to achieve a realistic understanding of diet and socio-cultural dynamics during the Quaternary. Full article