24 research outputs found
Analysis of Temporal and Spatial Evolution Characteristics of Land Subsidence in Western Songnen Plain Using Multisource Remote Sensing
AbstractThe exploitation of underground fluid is an important factor leading to land subsidence. The effects of mining depth, frequency, and mode on land subsidence are also different. The objective of this study was to develop a multisource method—including optical remote sensing interpretation, Interferometric Synthetic Aperture Radar (InSAR) technology, and unmanned aerial vehicle (UAV)—to reveal the long-term temporal and spatial evolution law of subsidence characteristics driven by groundwater and oil extraction, as well as to reveal the formation mechanism and seasonal response law of land subsidence under the action of different driving factors. In this paper, we select the western region of Jilin Province located in Songnen Plain as the study area. The subsidence funnels in the study area are distributed in a porphyritic manner, and the distribution of the subsidence funnels has a certain correlation with the distribution of the pumping wells. In farmland areas, the subsidence is mainly caused by pumping groundwater. The annual land subsidence rate in the study area is -3.14 mm/a, and the maximum deformation rate in the study area is -22.05 mm/a. The subsidence is affected by the season, shown by the fact that it rises in the dry season and decreases in the rainy season. The subsidence in the west of Songnen Plain is caused by oil pumping and groundwater pumping, and groundwater pumping is dominant. The exploitation of underground fluid transfers the pressure borne by water or oil to the soil skeleton so as to increase and consolidate the effective stress of the soil layer and lead to land subsidence. The continuous observation of the surface in the western area of Songnen Plain is helpful to guide the safe production of agriculture and industry and ensure the smooth development of local industry and agriculture
The Importance of Food Security from the Perspective of Food Issue of the Roman Empire
This paper firstly introduced characteristics of the food production (or grain production) and regulation of the prosperous period of the Roman Empire. Then, it discussed the shortcomings and summarized the experience and lessons. It is expected to provide some references for construction of China’s food security
The Effect of Children’s Innovative Education Courses Based on Fractional Differential Equations
Fractional differential equations are one of the important contents of advanced mathematics courses. The article uses fractional differential equations to describe the effects of children’s innovative education courses. Through the qualitative analysis of the basic model, several conditions to ensure the effect of children’s innovative education courses are obtained. At the same time, combined with practical experience, the teaching curriculum case design analyzes the specific application of the fractional differential equation in the effect of children’s innovative education curriculum. Research has found that the fractional differential equation algorithm improves the efficiency of innovation
Flash Flood Hazard Susceptibility Mapping Using Frequency Ratio and Statistical Index Methods in Coalmine Subsidence Areas
This study focused on producing flash flood hazard susceptibility maps (FFHSM) using frequency ratio (FR) and statistical index (SI) models in the Xiqu Gully (XQG) of Beijing, China. First, a total of 85 flash flood hazard locations (n = 85) were surveyed in the field and plotted using geographic information system (GIS) software. Based on the flash flood hazard locations, a flood hazard inventory map was built. Seventy percent (n = 60) of the flooding hazard locations were randomly selected for building the models. The remaining 30% (n = 25) of the flooded hazard locations were used for validation. Considering that the XQG used to be a coal mining area, coalmine caves and subsidence caused by coal mining exist in this catchment, as well as many ground fissures. Thus, this study took the subsidence risk level into consideration for FFHSM. The ten conditioning parameters were elevation, slope, curvature, land use, geology, soil texture, subsidence risk area, stream power index (SPI), topographic wetness index (TWI), and short-term heavy rain. This study also tested different classification schemes for the values for each conditional parameter and checked their impacts on the results. The accuracy of the FFHSM was validated using area under the curve (AUC) analysis. Classification accuracies were 86.61%, 83.35%, and 78.52% using frequency ratio (FR)-natural breaks, statistical index (SI)-natural breaks and FR-manual classification schemes, respectively. Associated prediction accuracies were 83.69%, 81.22%, and 74.23%, respectively. It was found that FR modeling using a natural breaks classification method was more appropriate for generating FFHSM for the Xiqu Gully
Landslide Susceptibility Mapping in Vertical Distribution Law of Precipitation Area: Case of the Xulong Hydropower Station Reservoir, Southwestern China
This study focused on landslide susceptibility analysis mapping of the Xulong hydropower station reservoir, which is located in the upstream of Jinsha River, a rapidly uplifting region of the Tibetan Plateau region. Nine factors were employed as landslide conditioning factors in landslide susceptibility mapping. These factors included the slope angle, slope aspect, curvature, geology, distance-to-fault, distance-to-river, vegetation, bedrock uplift and annual precipitation. The rapid bedrock uplift factor was represented by the slope angle. The eight factors were processed with the information content model. Since this area has a significant vertical distribution law of precipitation, the annual precipitation factor was analyzed separately. The analytic hierarchy process weighting method was used to calculate the weights of nine factors. Thus, this study proposed a component approach to combine the normalized eight-factor results with the normalized annual precipitation distribution results. Subsequently, the results were plotted in geographic information system (GIS) and a landslide susceptibility map was produced. The evaluation accuracy analysis method was used as a validation approach. The landslide susceptibility classes were divided into four classes, including low, moderate, high and very high. The results show that the four susceptibility class ratios are 12.9%, 35.06%, 34.11%and 17.92% of the study area, respectively. The red belt in the high elevation area represents the very high susceptibility zones, which followed the vertical distribution law of precipitation. The prediction accuracy was 85.74%, which meant that the susceptibility map was confirmed to be reliable and reasonable. This susceptibility map may contribute to averting the landslide risk in the future construction of the Xulong hydropower station
Genome-Wide Identification and Expression Analysis of the <i>High-Mobility Group B</i> (<i>HMGB</i>) Gene Family in Plant Response to Abiotic Stress in Tomato
High-mobility group B (HMGB) proteins are a class of non-histone proteins associated with eukaryotic chromatin and are known to regulate a variety of biological processes in plants. However, the functions of HMGB genes in tomato (Solanum lycopersicum) remain largely unexplored. Here, we identified 11 members of the HMGB family in tomato using BLAST. We employed genome-wide identification, gene structure analysis, domain conservation analysis, cis-acting element analysis, collinearity analysis, and qRT-PCR-based expression analysis to study these 11 genes. These genes were categorized into four groups based on their unique protein domain structures. Despite their structural diversity, all members contain the HMG-box domain, a characteristic feature of the HMG superfamily. Syntenic analysis suggested that tomato SlHMGBs have close evolutionary relationships with their homologs in other dicots. The promoter regions of SlHMGBs are enriched with numerous cis-elements related to plant growth and development, phytohormone responsiveness, and stress responsiveness. Furthermore, SlHMGB members exhibited distinct tissue-specific expression profiles, suggesting their potential roles in regulating various aspects of plant growth and development. Most SlHMGB genes respond to a variety of abiotic stresses, including salt, drought, heat, and cold. For instance, SlHMGB2 and SlHMGB4 showed positive responses to salt, drought, and cold stresses. SlHMGB1, SlHMGB3, and SlHMGB8 were involved in responses to two types of stress: SlHMGB1 responded to drought and heat, while SlHMGB3 and SlHMGB8 responded to salt and heat. SlHMGB6 and SlHMGB11 were solely regulated by drought and heat stress, respectively. Under various treatment conditions, the number of up-regulated genes significantly outnumbered the down-regulated genes, implying that the SlHMGB family may play a crucial role in mitigating abiotic stress in tomato. These findings lay a foundation for further dissecting the precise roles of SlHMGB genes
Inundation depth controls leaf photosynthetic capacity by regulating leaf area and N content in an estuarine wetland
Background and AimsEstuarine wetlands are important carbon sinks, with plant photosynthesis being a vital component of this process. Changes in the inundation depth of wetlands could alter leaf photosynthesis and thus ecosystem carbon uptake capacity, ultimately determining the size of carbon sink. However, the relationship between inundation depth and photosynthetic capacity has yet to be determined, especially in estuarine wetlands with complex hydrological conditions. In addition, there is also conflicting evidence regarding the effect of inundation depth on photosynthetic capacity.MethodsTo better understand the mechanisms of photosynthetic capacity responding to inundation depth, we performed a field experiment with a gradient of inundation depths (0, 5, 10, 20, 30 and 40 cm) in estuarine wetland dominated by Phragmites australis in the Yellow River Delta, China.ResultsOur results showed that inundation depth significantly altered leaf morphological traits, elements and photosynthetic capacity. In particular, leaf photosynthetic capacity was obviously increased with increasing inundation depth. The increased leaf area enhanced light harvesting ability of leaves, and then increased Pn at different inundation depths. Besides, higher leaf N content promoted leaf photosynthetic capacity at different inundation depths.ConclusionOverall, the findings demonstrated that inundation depth significantly enhanced the photosynthetic capacity of P. australis, which was correlated with altered leaf functional traits in wetlands. Our results hold important implications for more accurately predicting the relationship between photosynthetic capacity and inundation depth in wetland ecosystems under climate change and more accurately estimating of the carbon sink capacity of wetland ecosystems in the future
Association Between Polymorphism in Diabetes Susceptibility Gene Insulin-Like Growth Factor 2mRNA–Binding Protein 2 and Risk of Diffuse Large B-Cell Lymphoma
Background: Numerous studies have shown that polymorphisms in the diabetes susceptibility gene, insulin-like growth factor 2mRNA–binding protein 2 (IGF2BP2), are associated with the occurrence and development of various malignant tumors; however, their correlation with the onset of diffuse large B-cell lymphoma (DLBCL) is still unknown. Therefore, this study aimed to explore whether IGF2BP2 polymorphisms increase the risk of developing DLBCL. Methods: This study included 295 DLBCL patients and 331 healthy individuals. Peripheral blood was collected, and polymerase chain reaction-ligase detection reaction (PCR-LDR) was used to detect IGF2BP2 gene polymorphisms. Logistic regression was used to assess the association between IGF2BP2 polymorphism and the risk of DLBCL, adjusted for age, sex, and body mass index (BMI). P < .05 indicated statistical significance. Results: The rs4402960 polymorphism in the IGF2BP2 gene was associated with the occurrence and development of DLBCL. After adjusting for age, sex, and BMI, GT (odd ratio [OR] = 1.54; 95% confidence interval [CI] = 1.08-2.19; P = .016), TT (OR = 2.00; 95% CI = 1.09-3.68; P = .026), and T genotype carrying (GT + TT) (OR = 1.62; 95% CI = 1.17-2.25; P = .004) significantly increased the risk of DLBCL. This study also found that the polymorphism rs1470579 was related to the development of DLBCL. After adjusting for age, sex, and BMI, AC (OR = 1.55; 95% CI = 1.11-2.17; P = .010), CC (OR = 2.18; 95% CI = 1.17-4.06; P = .014), and C genotype carrying (AC + CC) (OR = 1.64; 95% CI = 1.19-2.26; P = .002) significantly increased the risk of DLBCL. Conclusions: Our study found that polymorphism in the IGF2BP2 gene was associated with an increased risk of developing DLBCL
Effects of Vegetation Restoration Age on Soil C: N: P Stoichiometry in Yellow River Delta Coastal Wetland of China
Vegetation restoration can alter carbon (C), nitrogen (N), and phosphorus (P) cycles in coastal wetlands affecting C: N: P stoichiometry. However, the effects of restoration age on soil C: N: P stoichiometry are unclear. In this study, we examined the responses of soil C, N, and P contents and their stoichiometric ratios to vegetation restoration age, focusing on below-ground processes and their relationships to aboveground vegetation community characteristics. We conducted an analysis of temporal gradients based on the 'space for time' method to synthesize the effects of restoration age on soil C: N: P stoichiometry in the Yellow River Delta wetland of China. The findings suggest that the combined effects of restoration age and soil depth create complex patterns of shifting soil C: N: P stoichiometry. Specifically, restoration age significantly increased all topsoil C: N: P stoichiometries, except for soil total phosphorus (TP) and the C: N ratio, and slightly affected subsoil C: N: P stoichiometry. The effects of restoration age on the soil C: N ratio was well constrained owing to the coupled relationship between soil organic carbon (SOC) and total nitrogen (TN) contents, while soil TP content was closely related to changes in plant species diversity. Importantly, we found that the topsoil C: N: P stoichiometry was significantly affected by plant species diversity, whereas the subsoil C: N: P stoichiometry was more easily regulated by pH and electric conductivity (EC). Overall, this study shows that vegetation restoration age elevated SOC and N contents and alleviated N limitation, which is useful for further assessing soil C: N: P stoichiometry in coastal restoration wetlands
Improvement of Seed Germination under Salt Stress via Overexpressing <i>Caffeic Acid O-methyltransferase 1</i> (<i>SlCOMT1</i>) in <i>Solanum lycopersicum</i> L.
Melatonin (MT) is a phytohormone-like substance and is profoundly involved in modulating nearly all aspects of plant development and acclimation to environmental stressors. However, there remain no studies about the effects of MT on tomato seed germination under salt stress. Here we reported that the overexpression of caffeic acid O-methyltransferase 1 (SlCOMT1) significantly increased both MT content and salt tolerance in the germinated seeds of a transgenic tomato relative to wild type (WT) samples. Physiological investigation showed higher amylase activity in the stressed overexpression seeds than WT, leading to the promoted starch decomposition and enhanced soluble sugar content. The stimulated production of osmolytes and enhanced activities of SOD, POD, and CAT, together with the significant reduction in H2O2 and O2·− accumulation, were revealed in the stressed overexpression seeds relative to WT, largely accounting for their lower membrane lipid peroxidation. qPCR assay showed that, upon salt stress, the transcript abundance of hub genes related to germination (SlCYP707A1, SlABA1, SlGA3ox2 and SlGA2ox4) and stress tolerance (SlCDPK1, SlWRKY33 and SlMAPK1) were distinctly altered in the overexpression samples when compared to WT, providing a molecular basis for MT-mediated improvement of seed salt tolerance. Altogether, our observations shed new insights into biological functions of SlCOMT1 and could expand its utilization in genetic improvement of tomato salt tolerance in future