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.

In order to gain a more accurate understanding of the dynamic characteristics of soil, vibration triaxial tests were conducted on representative sand and clay samples from the Beijing area. The study investigated the influence of varying loading frequencies, cyclic stress ratios, and confining pressures on soil strength and liquefaction resistance, while also analyzing changes in shear modulus and damping ratio. The dynamic shear modulus of both sand and clay decreases with increasing shear strain, with higher confining pressures resulting in larger shear moduli. For sand, the damping ratio decreases as shear strain increases; however, for clay it initially increases before decreasing. Overall, clay exhibits a larger dynamic shear modulus but smaller damping ratio compared to sand. The number of cycles experienced by both sand and clay samples decreases with increasing confining pressure or deviational stress. As loading frequency increases, the number of cycles gradually rises for sand samples but first increases then decreases for clay samples. The damping ratio of sand gradually declines with an increase in cycle count while that of clay remains relatively stable. The variations observed in shear modulus and damping ratio are influenced by factors such as loading frequency, confining pressure, and stress.

Freeze-thaw cycles significantly affect soil behavior, leading to pavement failures and infrastructure damage, especially in seasonally freezing regions. The application of road salt for deicing operations introduces high salt concentrations into soils, which can alter their physical properties. Salt in soils affects their freezing point, moisture migration, and overall freeze-thaw behavior. This study investigates the effects of varying sodium chloride (NaCl) concentrations on sandy soil using both the ASTM and low-temperature-gradient methods to simulate different freezing protocols. The methodology involved subjecting soil specimens with 0%, 0.2%, 1%, and 5% salt concentrations to freeze-thaw cycles and measuring parameters such as heave rate, maximum heave, water intake, moisture content, and salt migration. The results revealed that increasing salt concentration leads to a reduction in the freezing point, with the 5% NaCl concentration showing the most significant depression at 2.96 degrees C. The heave rate and maximum heave decreased with higher salt concentrations: the 5% NaCl concentration reduced the heave rate to 11.3 mm/day (ASTM method) and 1.5 mm/day (low-temperature-gradient method) from 22.5 mm/day (ASTM method) and 17.2 mm/day (low-temperature-gradient method) in control. Salt migration analysis indicated more variability in salt distribution within the soil profile under the low-temperature-gradient method, especially at higher salt concentrations. This variability is linked to osmotic suction effects, which retain more water within the soil matrix during freeze-thaw cycles. The study highlights the importance of considering both salinity and freezing protocols in understanding soil behavior under freeze-thaw conditions.

Root-lesion nematodes, particularly Pratylenchus neglectus and P. crenatus (PNC), are widely distributed in New Zealand and cause significant damage to maize roots, reducing crop productivity. Despite their economic importance, no comprehensive assessment of commercial maize hybrids' resistance to PNC has been conducted in the country. Significant variation was observed in the nematode reproduction factor (Rf) and final population (Pf) among hybrids. In Experiment 1 (initial population (Pi) = 1250 PNC kg(-)(1) soil), Rf ranged from 3.1 in hybrid P8500 to 7.1 in hybrid P9127, with Pf values ranging from 3863 to 8903 PNC kg(-)(1) soil + roots in 45 days. In Experiment 2 (Pi = 750 PNC kg(-)(1) soil), Rf ranged from 18.4 in hybrid P1613 to 37.5 in hybrid P8805, with Pf values from 13,784 to 28,426 PNC kg(-)(1) soil + roots in 60 days. These results indicate active nematode reproduction and substantial hybrid-dependent variation in host response. Experiment 3 examined the impact of varying initial inoculum densities (500, 1000 and 1500 PNC kg(-)(1) soil), showing a dose-dependent increase in Pf and corresponding root damage. Susceptible hybrid (P9127) exhibited up to 42% root dry weight and 22% shoot dry weight reductions. This study is the first systematic evaluation of PNC resistance in New Zealand maize hybrids. It identifies P9127 and P8805 as highly susceptible, and P0891, P8500, and P1613 as moderately resistant. These findings offer valuable benchmarks for future breeding and support nematode management in New Zealand.

Iron homeostasis is critical for plant growth; however, the mechanisms underlying responses to iron deficiency and toxicity remain poorly understood. We investigated the adaptive strategies of Ulmus pumila, focusing on leaf physiological, transcriptomic, and metabolomic responses to iron stresses. Both iron deficiency and toxicity impaired chlorophyll biosynthesis, PS II efficiency, and chloroplast ultrastructure, resulting in reduced photosynthetic capacity and etiolation/wilting phenotypes. Iron deficiency reduced antioxidant enzyme activity and ROS levels, while iron toxicity activated the antioxidant enzyme system in response to the ROS burst. Integrated transcriptomic and metabolomic analyses provided insights into the underlying mechanism of these divergent responses: iron deficiency promoted primary metabolic adjustments, particularly the upregulation of genes (e.g., MDH, ACO, and IDH) and metabolites (e.g., malic acid, citric acid, and fumaric acid) associated with the TCA cycle to meet energy demands. Conversely, iron toxicity triggered a metabolic shift from primary to secondary metabolism, upregulating the genes (e.g., CHS, CHI, and F3H) and metabolites (e.g., laricitrin, trifolin, and rutin) involved in flavonoids biosynthesis to mitigate oxidative stress. Overall, U. pumila employs distinct adaptive mechanisms to balance survival and growth under iron stress: prioritizing energy metabolism and iron uptake to meet energy demands and improve iron uptake efficiency under deficiency, and enhancing the secondary metabolism to mitigate oxidative damage under toxicity. These findings enhance understanding of plant nutrient homeostasis and stress adaptation, providing insights into mitigating the impacts of soil degradation on agriculture and forestry.

Root-knot nematodes Meloidogyne spp. are sedentary endoparasites that infest a wide range of plant species; they are also widely distributed, making them one of the most economically significant pests. Similarly, damage caused by Aphelenchoides fragariae can lead to substantial reductions in both crop yield and quality. This research focused on the rhizosphere of Helianthus tuberosus L. (variety Albik), grown in a Polish plantation. The experiment was conducted at the National Institute of Horticultural Research in Skierniewice, using concrete rings filled with medium sandy soil amended with 10% peat. The treatments included the following: control (no amendments), silver solution (Ag+) (120 mg/L soil), and vermicompost (Ve) (20 L of Eisenia fetida vermicompost). Each treatment was replicated four times. Compared with control, (Ve) significantly decreased the numbers of Aphelenchoides fragariae and Meloidogyne hapla, by about 48% and 31%. The application of (Ag+) led to the most significant reduction in population density in both nematode species, with A. fragariae decreasing by over 67% and M. hapla by approximately 75%.

Plants can sustain various degrees of damage or compensate for tissue loss by regrowth without significant fitness costs. This tolerance to insect herbivory depends on the plant's developmental stage during which the damage is inflicted and on how much tissue is removed. Plant fitness correlates, that is, biomass and germination of seeds, were determined at different ontogenetic stages, vegetative, budding, or flowering stages of three annual brassicaceous species exposed to feeding by Pieris brassicae caterpillars at different intensities. Fitness costs decreased with progressive ontogenetic stage at which damage was inflicted. Feeding on meristem tissues on vegetative and budding plants limited the plant's ability to fully compensate for tissue loss, whereas feeding on flowers resulted in full compensation or overcompensation in Sinapis arvensis and Brassica nigra. Herbivory promoted germination of seeds in the following year, thereby causing a shift in relative contribution to the next year's generation at the expense of contributing to the long-lived seed bank. Herbivory intensity affected fitness correlates of B. nigra and to a lesser extent of Sisymbrium officinale, but not of S. arvensis, demonstrating that even closely related plant species can differ in their specific responses to herbivory and that these can differently affect reproductive output. In terms of fitness costs, annual plant species can be quite resilient to herbivory. However, the extent to which they tolerate tissue loss depends on the ontogenetic stage that is under attack. Seed persistence in the soil has been proposed as a bet-hedging strategy of short-lived species to increase long-term fitness. Herbivore-induced changes in seed germination can result in a shift in the relative contribution of seeds to the seed bank and next year's generation.

Voronoi tessellations are a mathematical concept that appears in many examples in nature, such as the skin of giraffes, dry soil, and vegetable cells. In the context of biomimicry, these tessellations have been used to build impressive structures worldwide that are both aesthetically pleasing and structurally efficient. This paper proposes a methodology based on genetic algorithms (GA) to determine the structural topology of Voronoi flat roofs with tubular steel cross sections and a given boundary. The design variables correspond to the number and position of the Voronoi centers that form the tessellations within the roof, as well as the dimensions of the structural elements. This representation of the design variables creates an unstructured optimization problem. Such characteristic is addressed by an implicit redundant representation of possible solutions, which generates chromosomes with varying numbers of variables. The objective function relates to the weight of the roof, considering constraints raised in technical and constructive issues. The methodology was applied to four different roof boundaries: triangular, pentagonal, square, and rhombic. In general, the results provide optimal aesthetic solutions with a few Voronoi tessellations, based on the algorithm configuration and the multimodal nature of the search space. Convergence analysis indicates the possibility of the algorithm getting stuck in an optimum local and shows the progressive reduction of Voronoi centers. Lastly, it is observed that the maximum displacement constraint leads to the shape of the optimal roof.

Subterranean termites, Anacanthotermes ochraceus, are a widely distributed and mainly recognized in Saudi Arabia as agricultural pests and economically serious insects causing damage to wood structures. Because termites have a cryptic feeding habit and have developed resistance to several insecticides, the effectiveness of most synthetic insecticides against them has been diminished. This study was designed in laboratory using sawdust and sand bioassay to confirm six native entomopathogenic nematode (EPN) isolates' effectiveness including Steinernema feltiae NEM-29, S. feltiae AHN, Heterorhabditis indica NEM-19, H. indica NEM-18, H. bacteriophora NEM-26 and H. bacteriophora AHN22 against workers of A. ochraceus. Results revealed that termite worker mortality was higher in the sawdust bioassay than in sand bioassay. At both tested assay methods, S. feltiae had a significantly greater mortality rate, followed by H. indica and H. bacteriophora. The maximum mortalities (100% and 79.0%) was recorded for S. feltiae AHN at 1000 IJs/termite with lower LC50 values of 7.3 and 73.8 IJs/termites at 16 d-post exposure in sawdust and sand assay, respectively. All tested EPN strains reproduced successfully and emerged from dead A. ochraceus workers in 8-14 days with higher reproduction rate (22,193 IJs/termite) for S. feltiae AHN in sawdust bioassay. Conclusively, it has been discovered that native EPNs can control termites more successfully, presumably due to they have the ability to spread further infections via infected dead individuals and can directly interact with termite pests in the soil.

Structural health monitoring (SHM) is crucial in the early stage of damage formation for the life-cycle service of offshore structures. The influence of soils on vibration-based damage detection systems in offshore structures is a critical issue but has received less attention in previous literature. Due to the complexity of offshore structures and their exposure to diverse loads, simultaneous compound damages across different components can occur, posing a significant challenge for damage detection. Existing methods often treat compound damage as a distinct type of damage, independent of corresponding single damages. Nonetheless, in cases where damages arise concurrently, the distinct characteristics of each individual damage are evident independently within the vibration signals. This study presents a new approach for detecting both single and compound damage in offshore structures considering soil interaction using vibration data. The approach combines Wavelet Transform (WT) with a Multiple Interference Deep Convolutional Neural Network (MIDCNN) to effectively learn desired features and detect damage in these structures. The MIDCNN model is trained on time-frequency data from healthy and single damage states, without incorporating time-frequency data from compound damage during training. In the testing phase, the MIDCNN model intelligently alarms healthy, single damage states, and an untrained compound damage state based on predefined probabilistic conditions derived from the MIDCNN output probabilities. The time-frequency data are generated using the WT method, which is adept at capturing the natural characteristics of the structure while minimizing the influence of noise or irrelevant components. The proposed approach is validated using measured data from a laboratory-scale offshore monopile model with soil interaction. The findings demonstrate that the proposed method is more robust than other methods in extracting features and classifying various states, including healthy, single and compound damages.