Search Results (264)

The ecological drivers of wildlife crop-foraging behavior—whether as a compensatory response to natural resource scarcity or as opportunistic exploitation of anthropogenic food sources—remain poorly understood in human–wildlife conflict research. Traditional methodologies, which primarily rely on direct observation and morphological identification, have limitations in comprehensively quantifying wildlife dietary composition, particularly in accurately distinguishing between morphologically similar plant species and conducting precise quantitative analyses. This study utilized DNA metabarcoding technology (rbcL gene markers) to identify and quantify plant dietary components through fecal sample analysis, systematically investigating the dietary composition and patterns of agricultural resource utilization of wild rhesus macaques (Macaca mulatta) in human–wildlife interface zones of southwestern China. A total of 29 rhesus macaque fecal samples were analyzed (15 from spring and 14 from winter), identifying 142 plant genera, comprising 124 wild plant genera, and 18 crop genera. The results revealed distinct seasonal foraging patterns: crops accounted for 32.11% of the diet in winter compared to 7.66% in spring. Notably, rhesus macaques continued to consume crops even during spring when wild resources were relatively abundant, challenging the traditional hypothesis driven by resource scarcity and suggesting that crop-foraging behavior may reflect an opportunistic, facultative resource selection strategy. This study demonstrates the significant value of DNA metabarcoding technology in wildlife foraging behavior research, providing scientific evidence for understanding human–primate conflict ecology and developing effective management strategies. Full article

Vegetation succession is a critical indicator of ecosystem structure and function and is often disrupted by the expansion of invasive species. However, ecosystem-scale studies elucidating invasion-driven succession mechanisms remain limited. This research focused on the Yancheng coastal salt marsh and analyzed the distribution variation of invasive species (Spartina alterniflora) and native species (Suaeda salsa and Phragmites australis) from 1987 to 2022 via the Google Earth Engine and random forest method. Logistic/Gaussian models were used to quantify land–sea distribution changes and vegetation succession trajectories. By integrating data on soil salinity, invasion duration, and fractional vegetation cover, generalized additive models (GAMs) were applied to identify the main factors influencing vegetation succession and to explore how Spartina alterniflora invasion affects the succession of salt marsh vegetation. The results indicated that the areas of Spartina alterniflora and Phragmites australis significantly increased by 3787.49 ha and 3452.60 ha in 35 years, respectively, contrasting with Suaeda salsa’s 82.46% decline. The FVC in the area has significantly increased by 42.10%, especially in the coexisted areas of different vegetation communities, indicating intensified interspecific competition. The overall trend of soil salinity was decreasing, with a decrease in soil salinity in native species areas from 0.72% to 0.37%. From the results of GAMs, soil salinity, tidal action, and invasion duration were significant factors influencing the distribution of native species, but salinity was not a significant factor affecting the Spartina alterniflora distribution. The findings revealed that the expansion of Spartina alterniflora changed the soil salinity and interspecific interactions, thereby altering the original plant community structure and establishing a new vegetation succession. This study enhances the understanding of the impacts of invasive species on ecosystems and offers theoretical support for salt marsh restoration. Full article

This study uses ordinary Portland–sulfate–silicate composite cement as the matrix and investigates the effects of water–cement ratio, HPMC dosage, and PCS dosage on the performance of specialized grouting materials for subway structure repair during operation through single-factor experiments and orthogonal experiments. Multifactorial variance analysis was employed to quantitatively evaluate the sensitivity of each factor and their interactions to slurry flowability, setting time, anti-dispersibility, and compressive strength. The results show that the water–cement ratio is the most critical factor affecting the performance of the grouting material, with extremely significant impacts on all performance indicators; HPMC dosage significantly affects flowability, setting time, and anti-dispersibility; PCS dosage primarily influences 2 h compressive strength; the interaction between water–cement ratio and HPMC dosage has a significant impact on anti-dispersibility. Principal component analysis revealed the trade-off relationship between flowability, setting time, and strength. The study established a sensitivity ranking for the performance of specialized grouting materials: water–cement ratio > HPMC dosage > PCS dosage > interaction, providing a theoretical basis and methodological reference for the formulation optimization of specialized grouting materials for subway structure repair during operation. Full article

A waste amidoxime chelate resin (WAR) was converted into a magnetic composite adsorbent (MCA) via carbonization and magnetization for the effective removal of Cr(VI). Under optimized conditions (pH = 1, 30 °C, 1 h), the adsorbent achieved a maximum Cr(VI) adsorption capacity of 197.63 mg/g. The adsorption process conformed to the pseudo-second-order kinetic model (R² > 0.98) and Langmuir isotherm model (R² > 0.99). The materials can be separated by magnetism. The primary mechanism for the adsorption of Cr(VI) involved monolayer chemisorption. FTIR spectroscopy confirmed the dominant role of -C=O, C-O, and Fe-O in the adsorption process. XPS spectroscopy confirmed the dominant role of -C=O and C-O in the adsorption process. The successful conversion of the WAR into an MCA not only mitigates waste accumulation but also provides a cost-effective strategy for heavy metal remediation. Full article

This study addresses the parallel operation of multiple compressor units in the gas injection process of gas storage facilities. A multi-objective optimization model based on the NSGA-II algorithm is proposed to maximize gas injection volume while minimizing energy consumption. Thermodynamic models of compressors and flow–heat transfer models of air coolers are established. The influence of key factors, including inlet and outlet pressures, temperatures, and natural gas composition, on compressor performance is analyzed using the control variable method. The results indicate that the first-stage inlet pressure has the most significant impact on gas throughput, and higher compression ratios lead to increased specific energy consumption. The NSGA-II algorithm is applied to optimize compressor start–stop strategies and air cooler speed matching under high, medium, and low compression ratio conditions. This study reveals that reducing the compression ratio significantly enhances the energy-saving potential. Under the investigated conditions, adjusting air cooler speed can achieve approximately 2% energy savings at high compression ratios, whereas at low compression ratios, the energy-saving potential reaches up to 8%. This research provides theoretical guidance and technical support for the efficient operation of gas storage compressor units. Full article

The apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of amino acids, digestible energy (DE), metabolizable energy (ME), and the apparent total tract digestibility (ATTD) of nutrients in 10 fishmeal (FM) samples were evaluated in weaned barrows (Duroc × Landrace × Yorkshire) using two experiments. In Experiment 1, 11 piglets (18.87 ± 0.10 kg) fitted with T-cannulas were randomly allocated to an 11 × 6 Latin-square design with 11 diets (1 nitrogen-free diet and 10 assay diets) and six periods. The AID and SID of all amino acids (AAs) except proline showed significant differences among all FM (p < 0.05). Importantly, the SID of amino acids was positively correlated with key antioxidant markers and immune parameters, and it was negatively correlated with oxidative stress markers (MDA) and pro-inflammatory cytokines (IL-2 and IL-6). In Experiment 2, 11 piglets (18.05 ± 1.15 kg) were assigned to an 11 × 5 Latin-square design with 11 diets (a 96.35% corn diet and 10 assay diets) and five consecutive periods. Significant variations were observed in the DE, ME, and ATTD of dry matter among different FM samples (p < 0.05). Moreover, predictive equations for estimating the SID of lysine, methionine, threonine, and tryptophan, as well as DE and ME, were established using stepwise regression analysis based on the chemical composition of the FM. These findings demonstrate that the nutritional value of FM in nursery pig diets has been underestimated, and this study provides precise data and predictive methods for evaluating the nutritional quality of FM in precision nutrition. Full article

This study investigates the impact of dynamically adjusting the potassium-to-calcium ratio (molar ratio) in nutrient solutions used on cherry tomatoes at different growth stages (seedling, flowering and fruit setting, and maturity) to enhance fruit appearance, nutritional quality, and mineral content. By focusing on the ‘Saopolo’ variety, 17 treatments were implemented, each involving a specific potassium-to-calcium ratio in the nutrient solutions applied during the seedling, flowering and fruit setting, and fruiting stages. The aim was to optimize the nutrient solution formula and enhance fruit quality. Fruit quality parameters were assessed at the initial maturity stage across various treatments, encompassing commodity quality (fruit stalk length, fruit shape index, and fruit hardness), taste quality (total soluble sugar, titratable acid content, and sugar-acid ratio), nutritional quality (vitamin C (Vc), soluble protein, and lycopene content), antioxidant quality (total phenol and flavonoid content), as well as comprehensive quality (soluble solids content). Principal component analysis was conducted on these parameters. Additionally, mineral element levels in fruits were analyzed at different developmental stages (white ripe, color transition, and mature stages). When tomato plants were treated with nutrient solutions containing varying potassium-to-calcium ratios at different growth stages, observations revealed distinct outcomes in the first fruit cluster. T15 (seedling stage (A): 0.5 times standard nutrient solution; flowering and fruit-setting stage (B): potassium-to-calcium = 1.6:1; fruiting stage (C): potassium-to-calcium = 2.1:1) exhibited the highest fruit firmness (1.54 kg·cm⁻²), while T14 (A; B (K:Ca = 1.6:1); C (K:Ca = 2.0:1)) elevated levels of total soluble sugars (6.59%), titratable acidity (0.74%), soluble proteins (2.79 mg·g⁻¹), and total phenolics (2.56 mg·g⁻¹). T13 (A; B (K:Ca = 1.6:1); C (K:Ca = 1.9:1)) demonstrated superior soluble solids (5.9%), lycopene (32.09 µg·g⁻¹), and flavonoid contents (0.77 mg·g⁻¹), whereas T12 (A; B (K:Ca = 1.6:1); C (K:Ca = 1.8:1)) showcased the highest sugar–acid ratio (12.63) and soluble solids content (5.9%). Notably, T8 (A; B (K:Ca = 1.5: 1); C (K:Ca = 1.9:1)) exhibited the highest Vc content (10.03 mg·100 g⁻¹). Mineral element analysis indicated that an increased potassium-to-calcium ratio in the nutrient solution during various growth stages enhanced phosphorus and potassium uptake by the fruits but hindered the absorption of nitrogen, calcium, magnesium, and iron. In summary, employing half the standard nutrient solution dosage during the seedling stage, utilizing a potassium-to-calcium ratio of 1.6:1 in the nutrient solution at the flowering and fruit setting stage, and applying nutrient solution T13 with a potassium-to-calcium ratio of 1.9:1 during the fruit-bearing phase, optimally coordinates fruit nutrient accrual and enhances flavor quality. These findings support the use of stage-specific nutrient modulation to improve cherry tomato quality in controlled-environment agriculture. Full article

Due to the rapid development of China’s economy, the current situation of fishing villages in the southeastern coastal areas is spatial disorder caused by changes in population composition and industrial transformation. This study analyses the differences between the clan structure and the multi-stakeholder engagement model in traditional fishing villages. The main aim is to illustrate contemporary issues that fishing villages’ spaces need to deal with in governance and decision making. With the development of information technology, social media has become an important platform through which stakeholders can communicate and make decisions. The aims of this paper were as follows: (1) Identify the stakeholders involved in the governance of fishing villages; (2) explore how stakeholders participate in the planning and governance of fishing villages through social media; (3) examine the mechanisms of social media and its impact on the spatial planning of fishing villages. Through qualitative research methods such as field surveys and in-depth interviews, the following results were obtained: (1) Social media subverts the traditional fishing village governance model, and the scope of the governance subject is expanded; (2) spatial changes in fishing villages are affected by the joint influence of people, the environment, and the economy, and a social network acts as an intermediary to compensate for the deficiencies that existed in previous fishing village governance processes. Full article

Liaoning cashmere goats is a dual-purpose breed valued for premium cashmere fiber and meat yields, and there is currently a lack of optimized strategies for meat quality, including skeletal muscle development and lipid partitioning. This investigation systematically examines how melatonin administration modulates gastrointestinal microbiota and antioxidant capacity to concurrently enhance skeletal muscle hypertrophy and redirect lipid deposition patterns, ultimately improving meat quality and carcass traits in Liaoning cashmere goats. Thirty female half-sibling kids were randomized into control and melatonin-treated groups (2 mg/kg live weight with subcutaneous implants). Postmortem analyses at 8 months assessed carcass traits, meat quality, muscle histology, plasma metabolites, and gut microbiota (16S rRNA sequencing). Melatonin supplementation decreased visceral adiposity (perirenal, omental, and mesenteric fat depots with a p < 0.05) while inducing muscle fiber hypertrophy (longissimus thoracis et lumborum (LTL) and biceps femoris (BF) with p < 0.05). The melatonin-treated group demonstrated elevated postmortem pH₂₄h values, attenuated muscle drip loss, enhanced intramuscular protein deposition, and improved systemic antioxidant status (characterized by increased catalase and glutathione levels with concomitant reduction in malondialdehyde with p < 0.05). Melatonin reshaped gut microbiota, increasing α-diversity (p < 0.05) and enriching beneficial genera (Prevotella, Romboutsia, and Akkermansia), while suppressing lipogenic Desulfovibrio populations, and concomitant with improved intestinal morphology as evidenced by elevated villus height-to-crypt depth ratios. These findings establish that melatonin-mediated gastrointestinal microbiota remodeling drives anabolic muscle protein synthesis while optimizing fat deposition, providing a scientifically grounded strategy to enhance meat quality. Full article

The contamination of paddy soils with arsenic (As) and cadmium (Cd), coupled with the depletion of soil organic carbon (SOC), poses significant threats to rice yields and quality. There is an urgent need to identify a suitable soil additive capable of achieving simultaneous heavy metal remediation and promotion of organic matter enrichment. The current study introduced two novel iron (Fe)/magnesium (Mg)-based bimetal-oxide-modified rice straw biochar (RSB), namely RSB-Fe/Mn and RSB-Fe/Mg. It evaluated their effectiveness in As/Cd immobilization and SOC preservation. An 8-week cultivation experiment was carried out in sequential drying–flooding moisture fluctuation conditions, with the soil pore water As/Cd (PWAs/Cd) and SOC fractions monitored. The mechanisms of As/Cd immobilization were investigated using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and X-ray Photoelectron Spectroscopy (XPS) characterizations. Results revealed that PWAs and PWCd were reduced by up to 67.1% and 80.2% during the drying period and by 27.0% and 76.5% during the flooding period, respectively. Additionally, SOC content increased by 16.3% and 33.9% with RSB-Fe/Mn addition during the drying and flooding period, respectively, with an increase in the mineral-associated organic carbon (MAOC) fraction. The study proves that RSB-Fe/Mn and RSB-Fe/Mg are effective for soil As/Cd passivation and SOC stabilization, offering a promising solution to mitigate As and Cd pollution in paddy soils while maintaining soil quality. Full article

The effects of stomatal factors of plant leaves under partial root-zone drying (PRD) have been widely studied. However, the non-stomatal factors and the relationship between photosynthesis with soil moisture have not been explored. In this study, four treatments over-irrigation, full irrigation, moderate water deficit, and severe water deficit were investigated, aiming to evaluate the effects on the diurnal variation of alfalfa leaf photosynthesis under PRD and its relationship with stomatal and non-stomatal limitations, as well as soil moisture. The results showed that any levels of water deficit led to a decrease in the photosynthetic rate (P_n) of alfalfa leaves. Leaves under moderate and severe water deficit displayed a pronounced midday “photosynthetic lunch break,” while those under over- and full irrigation did not display this phenomenon. Before 11:30 a.m., the reduction in P_n was primarily due to stomatal limitations, as evidenced by reduced stomatal conductance (G_s) and decreased intercellular CO₂ concentration (C_i). After 11:30 a.m., non-stomatal limitations became the dominant factor, with both G_s and transpiration rate (T_r) continuing to decrease, while C_i increased, indicating a shift in the limiting factors. Under PRD with moderate water deficit, alfalfa experienced both stomatal and non-stomatal limitations within a single day, leading to a hay yield reduction of 18.6%. Additionally, over-irrigation helped to maintain higher P_n and T_r, increasing alfalfa yield and thus improving water productivity by 33.1%. The correlation coefficients between soil moisture content at 10 cm depths with alfalfa leaf P_n, T_r, and G_s on the photosynthetic measurement day were 0.9864, 0.8571, and 0.8462, respectively. At 20 cm, the correlation coefficients were 0.8820, 0.6943, and 0.6951, respectively. The study concluded that both stomatal and non-stomatal mechanisms contributed to reduced alfalfa P_n in water deficit of PRD. Furthermore, shallow soil moisture also played a crucial role in influencing photosynthetic performance. Full article

In this study, the dissimilar joining of aluminum to high-melting-point alloys, including steel, titanium, and copper, was successfully achieved through hot-dipping. By precisely controlling the dipping temperature at 670 °C and maintaining a dipping time of 5 s, uniform aluminum layers with a thickness of 3–4 mm were successfully formed on the surfaces of high-melting-point alloys. This process enabled effective dissimilar metal joining between Al/steel, Al/Ti, and Al/Cu. Metallurgical bonding at the joining interfaces was achieved through the formation of uniform intermetallic compounds, specifically Fe₄Al₁₃, TiAl₃, Al₂Cu, and Al₃Cu₄, respectively. The different joints exhibited varying mechanical properties: the Al/Cu joint demonstrated the highest shear strength at 79.1 MPa, while the Fe₄Al₁₃-containing joint exhibited the highest hardness, reaching 604.4 HV. Numerical simulations revealed that an obvious decrease in interfacial temperature triggered the solidification and growth of the aluminum layer. Additionally, the specific heat and thermal conductivity of the high-melting-point alloys were found to significantly influence the thickness of the aluminum layer. The hot-dip joining technology is well suited for dissimilar metal bonding involving large contact areas and significant differences in melting points. Full article

Jasmonates (JAs) are essential signaling molecules that orchestrate plant responses to abiotic and biotic stresses and regulate growth and developmental processes. MYC2, a core transcription factor in JA signaling, plays a central role in mediating these processes through transcriptional regulation. However, the broader regulatory functions of MYC2, particularly in secondary metabolism and stress signaling pathways, are still not fully understood. This review broadens that perspective by detailing the signaling mechanisms and primary functions of MYC2 transcription factors. It specifically emphasizes their roles in regulating the biosynthesis of secondary metabolites such as alkaloids, terpenes, and flavonoids, and in modulating plant responses to environmental stresses. The review further explores how MYC2 interacts with other transcription factors and hormonal pathways to fine-tune defense mechanisms and secondary metabolite production. Finally, it discusses the potential of MYC2 transcription factors to enhance plant metabolic productivity in agriculture, considering both their applications and limitations in managing secondary metabolite synthesis. Full article

Currently, the world is facing a serious agricultural water crisis, which also affects grassland areas. Alfalfa, a key perennial forage legume, consumes about 10% of China’s pastoral irrigation water. Reducing irrigation generally results in a loss of hay yield, but the effects on alfalfa quality and its relationship to water use are less clear. In this study, we explore alfalfa quality under different irrigation deficits and its relationship to water use in the Hexi Corridor of China. Alfalfa water use, quality yield (relative feeding value yield (RFV_yield) and crude protein yield (CP_yield)), and quality water use efficiency (relative feeding value water use efficiency (WUE_RFV) and crude protein water use efficiency (WUE_CP)) were measured in a field experiment. Alfalfa quality showed a negative correlation with the irrigation quota (the determination coefficient for relative feeding value was 0.375 and for crude protein was 0.289). There was a positive correlation between quality yield and irrigation quota (the determination coefficient for RFV_yield was 0.570 and for CP_yield was 0.631). The higher irrigation quota increased quality yield, which compensated for its negative effects on alfalfa quality. The mild and moderate water deficit treatments showed lower WUE_RFV than both the severe and no water deficit treatments. Moderate or mild water deficit is recommended to be used for one-year-old alfalfa treatment. No water deficit is beneficial to improve the quality water use efficiency of two-year-old alfalfa. Full article

Ferrochelatase is the terminal enzyme in heme biosynthesis. Bacillus thuringiensis (Bt) 97-27 contains two ferrochelatases, HemH1 and HemH2, but their regulatory mechanisms and functional differences under virous environmental stimuli remain unclear. This study confirmed that the iron uptake regulator protein (Fur) bound to the promoters of hemH1 and hemH2, with Fe²⁺ or Fe³⁺ enhancing this binding. Heterologous expression of HemH1 and HemH2 in Escherichia coli showed that pEH2/BL grew better than pEH1/BL under different 2,2′-Bipyridyl, Fe²⁺, and Fe³⁺ concentrations. Under iron limitation, the heme precursor ALA production decreased significantly in both strains. The heme production of pEH2/BL decreased sharply under iron-limited conditions, while that of pEH1/BL decreased significantly under iron-rich conditions. The H₂O₂ sensitivity experiment revealed that E. coli pEH1/BL was more tolerant to H₂O₂ than pEH2/BL. In Bt, ΔhemH2 was most sensitive to H₂O₂ stress, but complementation of hemH1 or hemH2 partially restored H₂O₂ resistance, with the overexpressed strain pHH2/Bt being most tolerant. β-galactosidase assays indicated that Fur positively regulated hemH1 and negatively regulated hemH2 under normal conditions, but this regulation reversed with 2.5 mM Fe³⁺. qRT-PCR showed upregulation of genes related to heme synthesis, oxidative stress, and ferrous iron transport. This study reveals the functional differentiation of HemH1 and HemH2 under the joint regulation of Fur and environmental factors, highlighting their synergistic roles in heme synthesis, heavy metal detoxification, and oxidative stress resistance to maintain bacterial physiological homeostasis. Full article