Search Results (460)

Soil organic carbon (SOC) stocks in cacao agroecosystems are characterized by accumulating large amounts. They depend on the balance between organic matter inputs (plant residues, roots) and losses (decomposition, erosion), being closely related to climatic conditions, soil nature, vegetation type, topography, and land management practices. The objective of this study was to quantify SOC stocks (0–30 cm) and assess key soil fertility indicators across 107 georeferenced sampling locations in cacao production systems of Guamal (Meta, Colombian Llanos Piedmont). Soil pH varies between extremely acidic and moderately acidic (3.8–6.0; mean 4.57), while available P (Bray II) and exchangeable bases showed low concentrations. Organic carbon concentration averaged 1.18% and bulk density averaged 1.17 g cm⁻³. SOC stocks averaged 41.10 Mg C ha⁻¹, ranging from 7.49 to 81.55 Mg C ha⁻¹, evidencing marked spatial contrasts in carbon storage. Spearman correlations highlighted coupled soil chemical controls, including positive associations of pH with Ca²⁺ and P availability and strong negative associations of pH and P with exchangeable Al³⁺, consistent with acidity-driven fertility constraints. Principal component analysis (PCA) further identified a dominant fertility gradient structured by pH, P availability, and Ca²⁺, and a second axis related to organic carbon and cation retention. Spatial modeling using inverse distance weighting (IDW) in ArcGIS supported the visualization of SOC stock variability across the study area. Overall, the results indicate that SOC stocks in these predominantly sandy soils are strongly influenced by acidity-related constraints and heterogeneous nutrient status, underscoring the need for site-specific management to jointly enhance soil fertility and climate-mitigation potential in cacao systems. Therefore, it would be advisable in the future to address the study of differential variations in soil C storage related to chemical fertilizer application rates, especially in the long term. Full article

The pronounced heterogeneity of high-Andean soils constitutes a critical constraint to the sustainable productivity of quinoa in southern Peru, where current yields (1.6 t ha⁻¹) remain well below potential (>5 t ha⁻¹). This study aimed to develop a spatially predictive model of a weighted soil quality index (SQIw), the edaphic supply of nitrogen (N), phosphorus (P) and potassium (K), and the agricultural gypsum requirement by integrating edaphoclimatic covariates through regression–kriging. A total of 198 quinoa-cultivated soil samples were analysed; a minimum data set (MDS) was defined using correlation and principal component analyses, and regression–kriging was applied to map SQIw and the variables of interest. The MDS comprised electrical conductivity (EC), organic matter (OM), available P, exchangeable Na, sand, clay, and effective cation exchange capacity (ECEC); exchangeable Na (Wi = 0.160) and available P (Wi = 0.158) received the largest weights in the SQIw. SQIw values ranged from 0.22 to 0.84 and supported a five-class soil quality taxonomy; spatial modelling revealed a dominance of moderate-quality soils across the territory (85.21% of the agricultural area, 13,461.19 ha). The model achieved R² = 0.56, RMSE = 0.05, and MAE = 0.04 for SQIw. Most of the area (12,175.65 ha; 77%) exhibited an intermediate gypsum requirement (9.73–14.33 t ha⁻¹). Nitrogen and phosphorus showed the greatest territorial limitations, whereas potassium was largely non-limiting (84.82–570.17 kg ha⁻¹). These results indicate that sodicity and N–P deficiencies are the primary functional constraints; the generated maps enable prioritisation of gypsum amendments and targeted variable-rate fertilisation strategies to optimise the sustainability of quinoa production in the Altiplano. Full article

In this work, the electronic, structural, and magnetic properties of Ti-, V-, Cr-, Mn-, and Ni-doped AgZnF₃ perovskites are systematically investigated using the Korringa–Kohn–Rostoker method combined with the coherent potential approximation (KKR-CPA) within the generalized gradient approximation (GGA). Transition metal dopants (Ti and V) at a concentration of 5% substituting the Zn site introduce 3d states that cross the Fermi level in the majority-spin channel, resulting in half-metallic behavior. Ferromagnetic stability is predicted for Ti-, V-, Cr-, and Mn-doped AgZnF₃ at a doping concentration of 5%. The TM-doped AgZnF₃ alloys exhibit noticeable variations in exchange splitting between the t₂g and e_g states of the TM-3d orbitals. In Ti-doped AgZnF₃, the calculated spin magnetic moments follow the expected trend based on crystal-field splitting theory. Furthermore, a clear correlation is observed between the nature of the transition metal dopant (Ti, V, Cr, Mn, and Ni) and the total magnetic moment of the system. Full article

Background/Objectives: Recent guidelines have emphasized the importance of early mobilization and rehabilitation of patients following cardiac surgery. However, studies on the optimal targets and prescription methods for phase I cardiac rehabilitation (CR) are lacking. This study aimed to evaluate the feasibility and utility of an early phase 1 submaximal cardiopulmonary exercise test (CPET) using a recumbent ergometer in patients who have undergone cardiac surgery. Methods: Twenty ambulatory patients who underwent cardiac surgery between December 2021 and February 2023 were referred to the CR department on the fifth postoperative day, and a CR program was initiated. The program was conducted five times a week, with hour-long sessions consisting of warm-up exercises, resistance training, aerobic exercises, and a cool-down period. A recumbent ergometer-based submaximal CPET was performed approximately nine days after the surgery, prior to discharge. Participants initiated the test at 0 W, and the workload was increased by 20 W after 2 min. During the test, researchers evaluated parameters including submaximal peak values of oxygen consumption (VO₂), metabolic equivalents of task, respiratory exchange ratio (RER), blood pressure, heart rate (HR), and rating of perceived exertion (RPE). The grip strength test, 6 min walk test (6MWT), Korean Activity Scale/Index (KASI), EuroQol-5 dimension (EQ-5D), and short-form 36-item health survey (SF-36) values were also measured prior to discharge. Results: Twenty patients (75% male, average age 62.50 ± 1.99 years) underwent CPET at a median of 9.0 (8.0; 12.5) days postoperative. The average exercise duration of the CPET was 411.75 ± 168.25 s. During the test, their submaximal peak VO₂ was 12.32 ± 0.75 mL/kg/min (corresponding to 46.65 ± 2.08% of VO₂ max). The submaximal peak RER was 1.01 (0.98–1.12), and the submaximal peak RPE was 15.00 ± 0.51. Furthermore, the submaximal peak HR was 111.8 ± 3.76 beats/min (equivalent to 70.95 ± 2.09% of age-predicted maximal HR). After adjustment for age and sex, statistically significant positive correlations were observed between the submaximal peak VO₂ and 6MWT, squat endurance test, KASI, EQ-5D, and the physical component summary (PCS) of the SF-36 questionnaire. The 6MWT, squat endurance test, KASI, and PCS of SF-36 showed a correlation coefficient (r) of 0.522 (p = 0.026), 0.628 (p = 0.005), 0.586 (p = 0.011), and 0.546 (p = 0.019), respectively. No significant cardiac events, such as ST elevation/depression or hemodynamic instability, were observed during the test. Conclusions: Our findings suggest that performing recumbent ergometer-based CPET during early phase 1 CR is safe and feasible. These results highlight the potential of recumbent ergometer-based CPET as a valuable tool for guiding the appropriate prescription of early CR programs following hospital discharge in patients undergoing cardiac surgery. Full article

This study investigated highbush blueberry (Vaccinium corymbosum L.) plants cultivated in distinct cultivation systems (greenhouse vs. open field) to determine if they exhibited significant differences in rhizosphere microbiota, soil nutrient profiles, and fruit metabolites. A clear metabolic trade-off was observed: open-field cultivation significantly enhanced fruit secondary metabolites, including anthocyanins (9.5% higher), flavonoids (56.0% higher), and ascorbic acid (15.6% higher). In contrast, greenhouse fruits were enriched in primary metabolites such as water-soluble sugars (28.3% higher) and total organic acids (30.2% higher) (p < 0.01 for all comparisons). These divergent metabolite profiles were correlated with distinct rhizosphere microenvironments. The open field soil exhibited higher organic carbon and microbial α-diversity, while the greenhouse soil was characterized by a niche with high availability of cations, lower pH, higher electrical conductivity, and elevated levels of exchangeable Ca²⁺, Mg²⁺, and available potassium. These contrasting niches were correlated with shifts in the rhizosphere microbiota assembly. Notably, the greenhouse soil was associated with a higher relative abundance of copiotrophic bacterial taxa such as Streptomyces and Bacillus, whose abundances showed strong positive correlations with cation availability (e.g., Streptomyces vs. Ca²⁺, correlation coefficient r = 0.827, p < 0.01). Multivariate analysis integrated these patterns, revealing that soil cations were negatively correlated with fruit antioxidants but positively linked to sugars and acids. This correlative study suggests that cultivation systems are strongly associated with fruit quality, potentially through their association with functionally specific rhizosphere microbiota that covaries with a shift in the plant’s resource allocation between growth (primary metabolism) and defense (secondary metabolism). Our findings provide an integrative framework for understanding how agricultural practices are associated with the soil–plant–microbe continuum to correlate with crop quality in perennial systems and generate testable hypotheses for future mechanistic research. Full article

Fungal endophytes are microorganisms that inhabit plant tissues without causing disease and emerge as critical mediators of plant stress tolerance, nutrient acquisition, and ecosystem resilience under diverse climate change scenarios. Their unique position within the host allows them to modulate physiological responses more closely than external microbiota. This review explores how endophytic fungi contribute to plant adaptation under climate-induced stresses such as heat, salinity, drought, pollution, and nutrient limitation, with a focus on molecular crosstalk, functional trait modules, and metabolic trade-offs. Key findings emphasize multilayered signaling systems, including MAMP/DAMP recognition, phytohormone regulation, immune tuning, ROS dynamics, and effector deployment, while emerging mechanisms such as cross-kingdom RNA and extracellular vesicle (EV)-mediated exchange are discussed as promising but currently limited in empirical validation within many endophytic systems. Endophytes also enhance nutrient exchange through conditional carbon-for-benefit trade and may shape rhizosphere microbiota and soil activities through plant-mediated inputs. Integrative multi-omics approaches provide predominantly correlational insights into the mechanistic basis of these effects, linking molecular function to ecosystem and community outcomes. These insights have potential applications in climate-resilient agriculture, phytoremediation, and ecosystem restoration; however, their large-scale implementation requires further field-based validation and context-specific assessment. Future priorities should focus on trait-based selection, ecological modeling, and biosafety evaluation to translate microbial functions into reliable field-level strategies that support sustainable crop performance under accelerating environmental stress. Full article

This study evaluated the geotechnical, mineralogical, chemical, and physico-mechanical properties of natural clays from two Portuguese regions, Aveiro and Taveiro, for their potential use as compacted landfill liners. A comprehensive set of tests was conducted, including particle size distribution, Atterberg limits, specific surface area (SSA), cation exchange capacity (CEC), swelling potential, and hydraulic conductivity (K), complemented by X-ray diffraction (XRD) and chemical composition (XRF) analyses. Results showed that Aveiro clays were predominantly fine-grained, with clay fractions exceeding 65% and high Σphyllosilicates content, particularly illite and smectite. These samples exhibited low hydraulic conductivity (K < 1 × 10⁻⁹ m/s), moderate to high plasticity, and good sealing behavior. In contrast, Taveiro clays showed greater textural variability, with higher sand content and a wider range of mineral composition, from kaolinitic to smectitic units. Selected Taveiro samples also achieved acceptable permeability values, particularly those with higher smectite content, but may require strict compaction control or blending with finer materials. The CEC and SSA measurements further distinguished the sealing potential between clay types, correlating with mineralogy and swelling capacity. The use of local clays offers potential cost savings and environmental benefits, including reduced transportation emissions and support for circular economy principles. These findings highlighted the technical viability of Portuguese clays for landfill barrier systems and underscore the importance of localized characterization for optimized liner design. Full article

This study presents an improved methodology for assessing the environmental sensitivity of the host rock in Huashan art paintings. A hygroscopic experiment was first designed to determine the moisture diffusion coefficient of the rock mass preserving the Huashan rock paintings, as verified by hygroscopic kinetics. Additionally, variations in color difference values were simultaneously used to quantitatively evaluate moisture absorption characteristics. Subsequently, a finite element (FE) simulation was conducted to assess potential damage to the rock art system with respect to varying environmental conditions. Regarding the correlated functions with consideration of the influencing factors, the environmental sensitivity of the host rock in Huashan art paintings was clarified to illustrate the deterioration process resulting from the combined effects of temperature and humidity. It is found that the deformation gradient (F) and maximum tensile stress (σ_max) exhibit a linear relationship with ambient temperature (T_a), and an exponential relationship with heat transfer coefficient (h). The ambient humidity (H_en) and surface humidity exchange coefficient (f) primarily influence the water content of the rock mass. This insight into the host rock in Huashan art paintings provides a valuable approach to highlight the active role of environmental conditions and offers an additional methodology to understand the detachment of large superficial rock flakes and the granular disintegration of the rock. Full article

Antibody–drug conjugates (ADCs) comprise a monoclonal antibody covalently bound to a cytotoxic payload by a linker. ADCs minimize off-target effects on healthy tissues, leveraging the specificity of monoclonal antibodies to deliver cytotoxic drugs to the intended tumor site. ADCs can be prone to poor behavior, including aggregation and misfolding, leading to poor efficacy, impaired pharmacokinetics, and immunogenicity. It is advantageous to understand the developability and potential liabilities of a protein candidate prior to costly in vivo studies or clinical trials. This review summarizes biophysical and structural techniques used to characterize ADCs and introduces emerging techniques aimed at accurately assessing the developability of protein candidates. Stability is commonly assayed using techniques like differential scanning calorimetry (DSC), differential scanning fluorimetry (DSF), or spectroscopic probes such as circular dichroism and intrinsic fluorescence. Drug-to-antibody ratio (DAR) is a critical parameter that can be measured using absorbance spectroscopy or chromatographic analysis. Aggregation and self-association can be probed using scattering techniques such as dynamic light scattering (DLS), static light scattering (SLS), and size exclusion chromatography–multi-angle light scattering (SEC-MALS), as well as more specialized approaches such as fluorescence correlation spectroscopy (FCS) and analytical ultracentrifugation (AUC). Mass spectrometry (MS) provides extremely valuable insight into stability, covalent modifications, and, through approaches like hydrogen–deuterium exchange (HDX-MS), structural dynamics of ADCs. Looking forward, the use of biophysical assays in ex vivo matrices and strategic use of artificial intelligence/machine learning (AI/ML) approaches are likely to advance the efficient and rapid development of ADCs and other next-generation protein therapeutics. Full article

Background/Objectives: Glioblastoma (GBM) is the most aggressive primary brain tumor in adults and remains associated with poor prognosis despite multimodal therapy. Metabolic reprogramming, particularly increased dependence on glutamine, supports GBM bioenergetic, biosynthetic, and redox demands. This study aimed to systematically identify glutamine-associated metabolic regulators with prognostic relevance and biological plausibility in GBM. Methods: Transcriptomic data from TCGA and GTEx were analyzed using GEPIA2, with survival validation performed using the CGGA. Functional pathway enrichment, protein expression assessment, protein–protein interaction network analysis, tumor microenvironment evaluation, epigenetic profiling, and single-cell RNA sequencing validation were integrated to contextualize candidate genes. Pharmacogenomic correlation analysis and structure-based molecular docking were applied as supportive validation layers. Results: Ceruloplasmin (CP), Solute Carrier Family 25 Member 13 (SLC25A13), and Solute Carrier Family 38 Member 2 (SLC38A2) were selectively dysregulated and associated with poor clinical outcomes in GBM. CP was linked to redox regulation and stress-adaptive survival programs, SLC25A13 to mitochondrial metabolite exchange and glutamine-coupled nucleotide biosynthesis, and SLC38A2 to glutamine uptake, nutrient sensing, and mTORC1-MYC-associated growth signaling. Conclusions: CP, SLC25A13, and SLC38A2 emerge as clinically relevant glutamine-associated metabolic regulators in GBM, linking redox regulation, mitochondrial metabolite exchange, and glutamine-driven growth signaling. These findings highlight transport- and exchange-centered metabolic nodes as potential biomarkers and candidates for future metabolic targeting in GBM. Full article

The effect of LiPF₆ acidity, represented by LiPF₆·xHF adduct formation and its interaction with fluoride species, on the surface reactivity and stability of LiPF₆ was investigated using density functional theory (DFT) calculations performed with the Vienna Ab initio Simulation Package (VASP). The exchange–correlation energy was described using the Perdew–Burke–Ernzerhof (PBE) functional within the Generalized Gradient Approximation (GGA). Four distinct surface terminations of the (003) and (101) facets—F4–P2–Li, P2–F3–Li, Li2–F3–P, and F4–Li2–P were systematically examined. Surface and adsorption energies were evaluated together with key electronic descriptors, including the work function, dipole moment, electron localization function (ELF), electrostatic potential, band structure, and density of states, to elucidate the mechanisms governing adsorption and stability. The (101) facet exhibits a pronounced susceptibility to HF-induced solvation, driven by enhanced surface polarity, a low work function, and intermolecular H–F interactions at lithium-exposed terminations. In contrast, the thermodynamically dominant (003) facet shows greater resistance to HF interaction, with adsorption remaining predominantly molecular and progressing toward deliquescence only at elevated HF concentrations. Fluorine-rich and charge-balanced terminations on both facets display enhanced stability, characterized by high work functions, minimal ELF redistribution, and suppressed charge transfer. Full article

Near-surface air temperature measurements are sensitive to solar radiation and ambient longwave irradiance, which can introduce measurement errors of approximately 1 °C. This study presents the design and experimental validation of a high-accuracy naturally ventilated radiation shield that operates without mechanical aspiration. Computational fluid dynamics (CFD) simulations were used to optimize a bowl–cover airflow-guiding structure and shading configuration, thereby enhancing air exchange around the sensing probe and reducing radiation-induced heating. A coupled multi-parameter simulation framework was further developed to evaluate the sensitivity of radiation error to wind speed, scattered radiation, altitude, and other environmental factors. Field intercomparison experiments were conducted using a Model 076B radiation shield as the reference and a Model 41003 radiation shield for comparison. Results show that the proposed shield exhibits a mean uncorrected radiation error of 0.12 °C, which is significantly lower than that of the 41003 shield (0.59 °C). In addition, a multilayer perceptron (MLP)-based radiation error correction model was developed using environmental parameters as inputs, achieving a root mean square error (RMSE) of 0.051 °C and a mean absolute error (MAE) of 0.043 °C. After correction, the correlation coefficient between Pt100 probe measurements and reference values reaches 0.999, demonstrating the potential of the proposed approach for high-accuracy near-surface air temperature observations. Full article

Plant leaf drought tolerance is regulated by the coordinated effects of water transport efficiency, transpirational water loss, and hydraulic safety. Although cotton is considered drought-tolerant, the mechanisms that coordinate water transport and gas exchange to confer drought tolerance remain incompletely understood. In this study, four soil moisture gradients were established under field conditions and maintained consistently throughout the growing season. The relationships among leaf turgor loss point (Ψ_tlp), gas exchange, and hydraulic traits were examined in two cotton cultivars at the peak flowering stage. With increasing drought treatments, Ψ_tlp, stomatal aperture ratio (g_ratio), leaf hydraulic conductance (K_leaf), leaf hydraulic conductance inside the xylem (K_x) and leaf hydraulic conductance outside the xylem (K_ox) declined significantly, with K_x showing the greatest reduction. Both K_x and g_ratio were strongly positively correlated with Ψ_tlp. Anatomically, vein density (D_v) and vessel number (Np) increased, whereas xylem vessel area (Ap) decreased. The reduction in Ap was the primary structural factor driving the decline in K_x and contributing to lower Ψ_tlp. We conclude that cotton enhances drought tolerance through a coordinated hydraulic and osmotic strategy, by modifying xylem anatomy (reducing Ap) to downregulate K_x and by adjusting osmotically to depress Ψ_tlp. The synergistic reduction in K_x and g_ratio slows the decline in leaf water potential, thereby delaying Ψ_tlp and enhancing leaf hydraulic safety during drought. This integration optimizes stomatal regulation and water transport while ensuring hydraulic safety. The findings provide a key theoretical basis and potential breeding targets for the targeted improvement of drought tolerance and water use efficiency in cotton. Full article

Urban wetlands on the Qinghai–Tibetan Plateau are increasingly recognized as potentially important components of city-scale carbon budgets; however, their CO₂ flux dynamics and associated environmental drivers remain insufficiently quantified, particularly under high-altitude urban conditions. In this study, we addressed this knowledge gap by conducting continuous eddy covariance observations at Haihu Wetland Park in Xining City, China. Carbon fluxes were monitored throughout 2023 using the Huangshui Park Station flux tower. We quantified the temporal dynamics of gross primary productivity (GPP), ecosystem respiration (Re), and net ecosystem exchange (NEE), and systematically assessed their responses to key environmental drivers across multiple temporal scales. GPP and Re exhibited unimodal seasonal patterns, with substantially higher values during the growing season. NEE showed pronounced diel cycling, with nighttime CO₂ release and daytime uptake, and shifted seasonally between net source and net sink states. At the daily scale (n = 365), Pearson correlations showed that air temperature (T_a), 5 cm soil temperature (T_s5) and volumetric soil water content (SWC) exhibited the strongest associations with the flux components, whereas photosynthetic photon flux density (PPFD) showed moderate associations and precipitation was weak. At the monthly scale (n = 12), Mantel tests further highlighted a dominant thermal control on GPP and Re (T_a and T_s5), whereas precipitation showed additional associations with Re and NEE. Overall, the ecosystem acted as a net CO₂ sink in 2023 (annual NEE = −292.25 g C m⁻² yr⁻¹ under our sign convention), with uptake concentrated in the first eight months of the year. Under the combined effects of multiple environmental factors, plateau urban wetlands functioned as a strong carbon sink, and the results of this study provide a data basis for improving the accuracy of carbon budget estimates for this type of ecosystem. Full article

Efficient apple orchard water management under climate variability requires understanding how fruit load and water supply regulate branch-scale water use to optimize irrigation, yield, and fruit quality. During the summer of 2014, sap flow (SF) and maximum daily shrinkage (MDS) were measured in one branch from six apple trees (Malus domestica Borkh. Cv. ‘Jazz™’) using the Compensation Heat Pulse method and diameter variation sensors in an orchard near Havelock North, New Zealand. One west-oriented branch per tree, with diameters of 1.5 to 2.3 cm, was monitored alongside midday stem (ψs) and leaf (ψl) water potentials, leaf gas exchanges, leaf area index (LAI), and fruit dry matter per branch at the end of the growing season. Half of the trees were subjected to irrigation withdrawal after day of year (DOY) 31 (non-irrigated treatment), resulting in a significantly lower midday stem water potential (ψs) by DOY 56 (−1.03 MPa). Pre-harvest, SF and MDS were tightly correlated (r² = 0.69), but this correlation decreased post-harvest (r² = 0.16) due to reduced fluctuations in both SF and branch variations (BV). SF was normalized per unit of leaf area, categorizing branches into high and low LAI: fruit dry matter ratio. SF values were approximately 2.2 times higher for FI pre-harvest and remained 2-fold higher post-harvest, associated with lower ψl and higher midday leaf transpiration for FI. MDS was identified as a better indicator of mild water deficit compared to SF, with both measurements responding effectively to midday vapor pressure deficit and reference evapotranspiration values. Overall, MDS proved to be a more sensitive indicator of mild water deficit than SF, while fruit load exerted a persistent influence on branch water use, highlighting the value of branch-scale measurements for improving irrigation management in apple orchards. Full article