Mexican rural communities suffer significant impacts on the health of their population due to the application of pesticides that contaminate local air, water, soil, and food. Prolonged exposure to these toxic substances affects the long-term health of the population, especially children, who are extremely vulnerable to damage to their physical and neurocognitive development. This problem is analyzed in the context of industrial and extractive agriculture, which focuses on monocultures for national and export markets within the framework of a lax and permissive behavior of the Mexican state that protects neither the health of workers nor the rights of children to a healthy life. This article presents the results of a case study in a rural locality in a region of intensive agriculture. Two urine samples were taken from 180 schoolchildren, ages 3-14, to analyze their exposure to pesticides in a mass chromatograph; the samples were supplemented with a survey of their families and an ethnographic study.

Salinity stress is one of the most detrimental abiotic factors affecting plant development, harming vast swaths of agricultural land worldwide. Silicon is one element that is obviously crucial for the production and health of plants. With the advent of nanotechnology in agricultural sciences, the application of silicon oxide nanoparticles (SiO-NPs) presents a viable strategy to enhance sustainable crop production. The aim of this study was to assess the beneficial effects of SiO-NPs on the morpho-physio-biochemical parameters of rice (Oryza sativa L., variety: DRR Dhan 73) under both normal and saline conditions. To create salt stress during transplanting, 50 mM NaCl was injected through the soil. 200 mM SiO-NPs were sprayed on the leaves 25 days after sowing (DAS). It was evident that salt stress significantly hindered rice growth because of the reductions in shot length (41 %), root length (38 %), shot fresh mass (40 %), root fresh mass (47 %), shoot dry mass (48 %), and root dry mass (39 %), when compared to controls. Together with this growth inhibition, elevated oxidative stress markers including a 78 % increase in malondialdehyde (MDA) and a 67 % increase in hydrogen peroxide (H2O2) indicating enhanced lipid peroxidation were noted. Increasing the chlorophyll content (14 %), photosynthetic rate (11 %), protein levels, total free amino acids (TFAA; 13 %), and total soluble sugars (TSS; 11 %), all help to boost nitrogen (N; 16 %), phosphorous (P; 14 %), potassium (K; 12 %), and vital nutrients. The adverse effects of salt stress were significantly reduced by exogenous application of SiO-NPs. Additionally; SiO-NPs dramatically raised the activity of important antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POX), and catalase (CAT), improving the plant's ability to scavenge reactive oxygen species (ROS) and thereby lowering oxidative damage brought on by salt. This study highlights SiO-NPs' potential to develop sustainable farming practices and provides significant new insights into how they enhance plant resilience to salinity, particularly in salt-affected regions worldwide.

Seasonal freezing and thawing significantly influence the migration and distribution of soil hydrothermal salts. Understanding the dynamics of hydrothermal salt forces in canal foundation soils is crucial for effective canal disease control and optimization. However, the impact on rectangular canals remains poorly understood. Therefore, field-scale studies on water-heat-salt-force-displacement monitoring were conducted for the canal. The study analyzed the changes and interaction mechanisms of water-heat-salt-force in the soil beneath the canal, along with the damage mechanisms and preventive measures. The results indicate that the most rapid changes in temperature, moisture, and salt occur in the subsoil on the canal side, with the greatest depth of freezing. Heat transfer efficiency provides an intuitive explanation for the sensitivity of ground temperature at the junction of the canal wall and subsoil to air temperature fluctuations, as well as the minimal moisture migration in this region under the subcooling effect. The temperature-moisture curve suggests that current waterheat-force and water-heat-salt-force models exhibit a delay in accurately predicting water migration within the subsoil. Rectangular canals are more susceptible to damage under peak freezing conditions, requiring a combined approach of freezing restraint and frost-heaving force to mitigate damage. These findings offer valuable insights for canal design, maintenance, and further research.

Moderate nitrogen addition can enhance plant growth performance under salt stress. However, the regulatory effects of nitrogen addition on the growth of the leguminous halophyte medicinal plant, Sophora alopecuroides, under salt stress remain unclear. In this study, a two-factor pot experiment with different NaCl levels (1 g/kg, 2 g/kg, 4 g/kg) and NH4NO3 levels (0 mg/kg, 32 mg/kg, 64 mg/kg, 128 mg/kg) was set up to systematically study the response of S. alopecuroides plant phenotype, nodulation and nitrogen fixation characteristics, nitrogen (N), phosphorus (P), potassium (K) nutrient absorption and utilization efficiency, plant biomass and nutrient accumulation to nitrogen addition under salt stress. The results demonstrated that under mild (1 g/kg NaCl) and moderate (2 g/kg NaCl) salt stress, S. alopecuroides exhibited a relatively low nitrogen demand. Specifically, low (32 mg/kg N) and medium (64 mg/kg N) nitrogen levels significantly enhanced nodule nitrogenase activity and nitrogen fixation capacity. Furthermore, the uptake of essential nutrients, including N, P, and K, in the aboveground biomass was markedly increased, which in turn promoted the accumulation of major nutrients such as crude protein, crude fat, and alkaloids, as well as overall biomass production. However, under severe (4 g/kg NaCl) salt stress, S. alopecuroides exhibited a preference for low nitrogen levels (32 mg/kg N). Under S3 conditions, excessive nitrogen application (e.g., 64 mg/kg and 128 mg/kg N) exacerbated the damage caused by salt stress, leading to significant inhibition of nitrogen fixation and nutrient uptake. Consequently, this resulted in a substantial reduction in biomass. This study provides a theoretical basis for nitrogen nutrition management of S. alopecuroides under salt stress conditions and offers valuable insights for optimizing fertilization and nutrient management strategies in saline-alkali agricultural production.

Drought and salt stress are two major abiotic factors significantly impacting crop growth and yield. Climate change leads to increasing drought and soil salinization issues, rising significant challenges to agricultural production. Amylases play a crucial role in enhancing the tolerance of crops to these stresses by regulating physiological and enzymatic activities. Previous study identified MeAMY1 and MeBAM3 as key genes involved in cassava starch metabolism under drought stress. To investigate their functions under drought and salt stress, MeAMY1 and MeBAM3 genes were cloned and over-expressed in Arabidopsis thaliana in the current study. Overexpression of MeAMY1 in Arabidopsis enhances amylase activities, promotes starch hydrolysis, releases soluble sugar and thus enhances osmotic balance in transgenic Arabidopsis. In the mean while, expression of BAM1 and SEX1 were depressed by MeAMY1 to maintain the protects cells closed under stress and preserved starch for adapting the stressful environments. Overexpression of the MeBAM3 in Arabidopsis can increase the expression levels of AMY3 and RVE1, promotes starch hydrolysis, releases soluble sugar from the chloroplasts to the cytoplasm and thus enhances osmoregulatory substance content, reducing stress-induced damage to antioxidant enzymes and cell membranes and improving stress tolerance. The principal component analysis further indicated that MeAMY1 and MeBAM3 overexpression lines responded similarly to drought stress, while MeBAM3 overexpression provided greater resilience to salt stress.

Root-knot nematodes (RKN) are globally distributed and highly pathogenic. By determining the threshold at which damage occurs, we can create effective measures to protect plants from nematodes. In our study, we investigated the impact of ten initial population densities (Pi-log series) of M. javanica, i.e., 0, 2.38, 2.68, 2.98, 3.28, 3.58, 3.88, 4.18, 4.48 and 4.78 juveniles (J2) g(-1) soil on tomato cv. S22 plants in pots. The graphical estimation of yield losses caused by RKN was calculated using Seinhorst's yield loss model based on the relationship between the RKN population and damage to tomato plants. The relationship between initial nematode population density (Pi) and plant yield was analyzed using Seinhorst's model, where T is the tolerance limit, m is the minimum yield, and z is a constant describing yield decline. This allowed us to determine the threshold at which nematode infestation significantly reduces tomato growth. Seinhorst's model, y = m + (1-m) 0.95(Pi/T-1) for Pi > T; y = 1 for Pi <= T for RKN, was fitted to the data of shoot length and fresh weight of infected and uninoculated control plants to estimate the damage threshold level. The impact of M. javanica on plant physiological parameters, including chlorophyll content, carotenoid and nitrate reductase activity, root-gall formation, and disease incidence, was also determined in this study. The tolerance limits for relative tomato shoot length and fresh weight were 3.34 J2 of M. javanica g(-1) soil. The minimum relative values (y(m)) for shoot length and fresh weights were 0.39 and 0.42, respectively. We found that the damage threshold level was between 3.28 and 3.58. The root galls index, nematode population and reproduction factors were 3.75, 113 and 29.42, respectively, at an initial population density (Pi) of 3.58 J2 g(-1) soil. The chlorophyll (0.43 mg g(-1)), carotenoids (0.06 mg g(-1)) and nitrate reductase activity (0.21 mu mol min(-1) g(-1)). Our study highlights the importance of the accurate estimation of damage thresholds, which can guide timely and effective nematode management strategies.

With global warming and intensified rainfall, the heat and moisture transfer processes within frozen subgrades beneath asphalt pavements have become increasingly complex, posing risks to highway stability in cold regions. This study developed a multi-physics coupled indoor simulation system based on a typical asphalt highway structure on the Qinghai-Tibet Plateau to examine subgrade responses under solar radiation, wind, and rainfall. Results showed that rainfall shifted the dominant depth of moisture migration from 7 cm to 12 cm, with moisture at 2 cm and 7 cm increasing rapidly by 2.67 % and 1.58 %, respectively. A nonlinear decrease-increase pattern was observed at 12 cm due to the capillary barrier effect. Evaporative latent heat significantly suppressed surface warming, reducing the temperature rise at 2 cm by 59.2 %, and delayed heat transfer to deeper layers (reductions of 54.5 %-64.7 %). A cumulative heat flux prediction model, incorporating solar radiation, evaporation, convection, and surface wetting, showed high accuracy (R-2 = 0.981 and 0.952; relative errors: 4.1 % and 9.6 %). Sensitivity analysis identified the surface wetting rate coefficient (beta) and evaporation attenuation coefficient (gamma) as dominant factors (F > 6.0). These findings improve understanding of rainfall-induced thermal effects and offer guidance for climate-resilient road infrastructure in permafrost regions.

In the northwestern saline soils and coastal areas, cement soil (CS) materials are inevitably subjected to various factors including salt erosion, dry-wet cycle (DWC), temperature fluctuations and dynamic loading during its service life, which the coupling effect of these unfavourable factors seriously threatened the durability and engineering reliability of CS materials. Additionally, combined with the substantially extensive application prospects of rubber cementitious material, as a resource-efficient civil engineering material and fibre-reinforced composites, consequently, in order to address aforementioned issues, this investigation proposed to consider the incorporation of rubber particles composite basalt fiber (BF) to CS materials as an innovative engineering solution to effectively enhance the mechanical and durability properties of CS materials for prolonging its service life. In this study, sulphate ions were utilized to simulate external erosive environment and basalt fibre rubber cement soil (BFRCS) specimens were subjected to various DWC numbers (0, 1, 4, 7, 11 and 15) in diverse concentrations (0 g/L, 6 g/L and 18 g/L) of Na2SO4 solution, and specimens that had completed the corresponding DWC number were then conducted both unconfined and dynamic compressive strength tests simultaneously to analyze static and dynamic stress-strain curves, static and dynamic compressive strength, apparent morphological deterioration characteristics and energy absorption properties of BFRCS specimens. Furthermore, further qualitative and quantitative damage assessments of pore distribution and microscopic morphology of BFRCS specimens under various DWC sulphate erosion environments were carried out from the fine and microscopic perspectives through pore structure test and scanning electron microscopy (SEM) test, respectively. The test results indicated that the static, dynamic compressive strength and specific energy absorption (SEA) of BFRCS specimens exhibited a slight increase followed by a progressive decline as DWC number increased. Additionally, compared to 4 mm BFRCS specimens, those with 0.106 mm rubber particle size demonstrated more favorable resistance to DWC sulphate erosion. The air content, bubble spacing coefficient and average bubble chord length of BFRCS specimens all progressively grew as DWC number increased, while the specific surface area of pores gradually decreased. The effective combination of BF with CS matrix significantly diminished pores and weak areas within specimen, and its synergistic interaction with rubber particles efficiently mitigated the stresses associated with expansive, contraction, crystallization and osmosis subjected by specimen. Simultaneously, more ettringite (AFt) had been observed within BFRCS specimens in 18 g/L sulphate erosive environments. These findings will facilitate the design and construction of CS subgrade engineering in northwestern saline soils and coastal regions, promoting sustainable and durable solutions while reducing the detrimental environmental impact of waste rubber.

A novel thermo-hydro-mechanical-chemical (THMC) coupling model grounded in thermodynamic dissipation theory was established to unravel the intricate behavior of unsaturated sulfate-saline soils during cooling crystallization. The model quantifies energy transfer and dissipation during crystallization and introduces a method to calculate the amount of sulfate crystallization. It intricately captures the interdependencies between crystallization, pore water pressure, crystallization pressure and volumetric expansion, while also accounting for the dynamic feedback of latent heat from phase transitions on heat conduction. The reliability of the model was validated through experimental data. Numerical simulations explored the effects of cooling paths, thermal conductivity, initial salt content and initial porosity on the crystallization behavior and mechanical properties. The model provides theoretical support for optimizing the engineering design and facility maintenance of sulfatesaline soils.

In the last decade, several studies have reported enrichments of the heavy isotopes of moderately volatile elements in lunar mare basalts. However, the mechanisms controlling the isotope fractionation are still debated and may differ for elements with variable geochemical behaviour. Here, we present a new comprehensive dataset of mass-dependent copper isotope compositions (delta 65Cu) of 30 mare basalts sampled during the Apollo missions. The new delta 65Cu data range from +0.14 %o to +1.28 %o (with the exception of two samples at 0.01 %o and -1.42 %o), significantly heavier than chondrites and the bulk silicate Earth. A comparison with mass fractions of major and trace elements and thermodynamic constraints reveals that Cu isotopic variations within different mare basalt suites are mostly unrelated to fractional crystallisation of silicates or oxides and late-stage magmatic degassing. Instead, we propose that the delta 65Cu average of each suite is representative of the composition of its respective mantle source. The observed differences across geographically and temporally distinct mare basalt suites, suggest that this variation relates to large-scale processes that formed isotopically distinct mantle sources. Based on a Cu isotope fractionation model during metal melt saturation in crystal mush zones of the lunar magma ocean, we propose that distinct delta 65Cu compositions and Cu abundances of mare basalt mantle sources reflect local metal melt-silicate melt equilibration and trapping of metal in mantle cumulates during lunar magma ocean solidification. Differences in delta 65Cu and mass fractions and ratios of siderophile elements between low- and high-Ti mare basalt sources reflect the evolving compositions of both metal and silicate melt during the late cooling stages of the lunar magma ocean.