Regions Of China Research Articles

Statistical Analysis of Moisture Sources and Quantitative Contribution of Cold Vortex Rainstorms in Northeast China during the Warm Season

Abstract The northeast cold vortex (NECV) is an essential system in the northeast region (NER) of China. Understanding the moisture source and associated transport characteristics of NECV rainstorms is the key to the knowledge of its mechanisms. In this study, we focus on two NECV rainstorm centers during the warm season (May–September) from 2008 to 2013. The Flexible Particle (FLEXPART) model and quantitative contribution analysis method are applied to reveal the moisture sources and their quantitative contribution. The results demonstrate that for the northern NECV rainstorm center (R1), Northeast Asia (35.66%) and east-central China and its coastal regions (29.14%) make prominent moisture contributions, followed by R1 (11.37%), whereas east-central China and its coastal regions (45.16%), the southern NECV rainstorm center itself (R2, 17.90%), and the northwest Pacific (10.24%) principally contribute to R2. Moisture uptake in Northeast Asia differs between R1 and R2, which could serve as one of the vital indicators to judge where the NECV rainstorm falls in NER. Moisture from the Arabian Sea, the Bay of Bengal, and the South China Sea suffers massive en route loss, although these sources’ contribution and uptake are positively correlated with the intensity and scale of NECV rainstorms in the two centers. There exists intermonth and geographical variability in NECV rainstorms when the main moisture source region contributes the most. Regulated by the atmospheric circulation and the East Asian summer monsoon, the particle trajectories and source contributions of NECV rainstorms vary from month to month. Sources’ contribution also turns out to be diverse in the overall warm season.

Correlation analysis of gamma-glutamyl transferase to lymphocyte ratio and patients with acute aortic syndrome in China: a propensity score-matched analysis.

Acute aortic syndrome (AAS) is a life-threatening condition in which there is a fracture in the integrity of the aortic wall. gamma-glutamyl transferase to lymphocyte ratio (GLR) is recognized as a risk factor for liver cirrhosis, fibrosis, and hepatocellular carcinoma. However, there are no clinical reports of GLR and AAS. We attempted to determine whether GLR level is associated with AAS in patients from the Chaoshan region of southern China. A total of 2,384 patients were recruited in this study and were divided into AAS and no-AAS groups according to the results of CT angiography of the thoracoabdominal aorta. Univariate and multivariate logistic regression was performed to identify risk factors for the occurrence of AAS. ROC was applied to assess the value of D-Dimer, GLR alone, or in combination for the diagnosis of AAS. And a 1:1 propensity score-matched analysis was performed. Multivariate logistics regression analysis indicated that male, age, hypertension, diabetes, creatinine, D-dimer, and GLR were independent risk factors of AAS patients in the before propensity score-matching cohort. After propensity score-matching, it showed that D-dimer, GLR [OR 3.558(1.891, 6.697); p < 0.001] were independent risk factors of AAS patients. Before propensity score-matching, the area under the curve (AUC) was 0.822 of GLR and 0.767 of D-dimer. When both clinical backgrounds were adjusted, the AUC was 0.773 of GLR and 0.631 of D-dimer. GLR showed high specificity (80.5% and 77.1%), and D-dimer showed high sensitivity (84.7% and 73.6%) in the before and after propensity score-matching cohort. GLR and D-dimer were independent risk factors of acute aortic syndrome. D-dimer in combination with GLR is more valuable than a single indicator for diagnosing acute aortic syndrome.

20th century climate warming and human disturbance triggered high aquatic production and strong water-column mixing in maar Lake Xiaolongwan, northeastern China

Lake ecosystems in northeastern (NE) China are sensitive to global environmental change, and are currently under threats of eutrophication and hypolimnetic anoxia. However, the lack of long-term records of lake production and anoxia in this region makes it difficult to discriminate the impacts of recent anthropogenic activity on lake ecosystems from natural ecosystem variability. This study investigates varved sediments from remote maar Lake Xiaolongwan, NE China and reconstructs high-resolution changes in lake primary production, anoxia, nutrient cycling and catchment processes over the past 1500 years using hyperspectral imaging inferred sedimentary total chlorophyll-a and bacteriopheophytin-a (Bphe-a), combined with sedimentary iron and phosphorus fractions data. Results show that, prior to discernible human impacts in this area from ~600 CE to 1900 CE, lake primary production was higher during warm periods and reduced during cold periods. Bphe-a records show that hypolimnetic anoxia persisted regardless of temperature variability. Cluster analysis suggests that lake algal communities and biogeochemical conditions in the twentieth-century warm period are unprecedented and significantly different from any other time over the past 1500 years. This pheonmenon mostly results from global warming and stronger local catchment disturbance in the early 1900s, combined with atmospheric pollution after the 1950s. Human-driven climate warming has caused stronger seasonal mixing (due to shortened ice-cover duration) and overall better oxygenation in the lake. This study demonstrates clear anthropogenic impacts to lake ecosytems in a relatively pristine region in NE China. We anticipate that our findings will have implications for understanding the status of aquatic ecosystems in NE China under future interacting stressors of anthropogenic climate warming and pollution.

Lithology and elevated temperature impact phoD-harboring bacteria on soil available P enhancing in subtropical forests

Plants are generally limited by soil phosphorus (P) deficiency in forest ecosystems. Soil available P is influenced by lithology, temperature, and soil microbes. However, the interactive effects of these factors on soil P availability in subtropical forests remain unclear. To assess their impacts, we measured soil inorganic and available P fractions and the diversity, composition, and co-occurrence network of phoD-harboring bacteria in two contrasting forest soils (lithosols in karst forests and ferralsols in non-karst forests) in the subtropical regions of southwestern China across six temperature gradients. The present results showed that the complexities in composition and network and the diversity indices of phoD-harboring bacteria were higher in the karst forest soils than those in the non-karst forest soils, with marked differences in composition. In both types of forest soils, the complexities of composition and networks and the diversity indices were higher in the high-temperature regions (mean annual temperature (MAT) > 16 °C) compared to the low-temperature regions (MAT <16 °C). Soil total inorganic and available P contents were lower in the karst forest soils compared to the non-karst forest soils. Soil total available P contents were lower in the high temperature regions than those in the low temperature regions in both forest soils, whereas soil total inorganic P contents were contrary. Variance partitioning analysis showed that soil inorganic and available P fractions were predominantly explained by lithology and its interaction with soil microbes and climate. The present findings demonstrate that soil P availability in subtropical forests of southwestern China is influenced by lithology and temperature, which regulate the diversity, composition, and network connectivity of phoD-harboring bacteria. Furthermore, this study highlights the significance of controlling the composition of phoD-harboring bacteria for mitigating plant P deficiency in karst ecosystems.

Biogeography and community assembly of soil fungi from alpine meadows in southwestern China show the importance of climatic selection

Soil fungi are pivotal in alpine and arctic ecosystems that are vulnerable to climate changes. Previous studies have shown broad connections between soil fungi in the arctic and alpine regions, but most of these studies are mainly from Europe and North America, with more sporadic studies from East Asia. Currently, little is known about the biogeographic relationships between soil fungi in alpine meadows of southwestern China (AMSC) and other regions of the world. In addition, the regional-scale spatial patterns of fungal communities in the AMSC, as well as their driving factors and ecological processes, are also poorly understood. In this study, we collected roots and surrounding soils of two dominant ectomycorrhizal plants, Bistorta vivipara and B. macrophylla from the AMSC, and performed bioinformatic and statistical analyses based on high-throughput sequencing of ITS2 amplicons. We found that: (1) fungi from the AMSC were closely related with those from boreal forests and tundra, and saprotrophic fungi had higher dispersal potential than ectomycorrhizal fungi; (2) community compositions exhibited clear divergences among geographic regions and between root and soil samples; (3) climate was the predominant factor driving regional-scale spatial patterns but had less explanatory power for saprotrophic and total fungi from roots than those from soils; (4) homogeneous selection and drift were the key ecological processes governing community assembly, but in communities of saprotrophic and total fungi from soil samples, drift contributed less and its role was partially replaced by dispersal limitation. This study highlights the importance of climatic selection and stochastic processes on fungal community assembly in alpine regions, and emphasizes the significance of simultaneously investigating fungi with different trophic modes and from both roots and soils.

Impacts of multiple temporal and spatial scale drought on grassland vegetation dynamics in the Tibetan Plateau region of China, 1982-2015

The Tibetan Plateau is a sensitive area to global climate change, and the special natural environmental conditions have nurtured extremely fragile vegetation and its ecosystems, making it one of the ideal regions to study the response of vegetation to climate change. In this study, we used the drought index (SPEI) and the vegetation index (NDVI) as drought and green indicators, respectively. The spatial and temporal variation patterns of vegetation greenness on the Tibetan Plateau from 1982 to 2015 were analysed, and the response of vegetation greenness to dry and wet changes was investigated. The results showed that the grassland vegetation improved overall (slope=0.00015, P<0.05) and degraded locally during 34 years. The NDVI of grassland vegetation showed an increasing trend from 1982 to 2008 (slope=0.00005, P=0.86), and a significant decreasing trend from 2009 to 2015 (slope=-0.002, P<0.05). The degraded areas of grassland NDVI were mainly distributed in wet areas. Meanwhile, the Tibetan Plateau as a whole showed a non-significant trend of increasing drought, with a mitigating trend of drought in dry areas and an increasing trend of drought in wet areas. The probability of vegetation growth loss was higher with increasing drought. The vulnerability of grassland vegetation to drought events was significantly higher in the humid region than in the arid region. Under the current drought intensification, the risk of loss of grassland vegetation to drought in the humid zone will increase. This suggests that we need to pay more attention to the stability of vegetation in the humid region and drought trends.

Modeling and analyzing patterns of residential manual window operation

Abstract Window operating behaviour can improve indoor air quality, human thermal comfort, and building energy efficiency. Studies on occupants’ window opening behaviour in hot summer and warm winter region of China are limited and influencing factors and prediction models are not clear. Another limitation is the large number of proposed machine learning-based window opening behaviour models. However, the applicability and stability of these models in different datasets has not been proven. In response to these questions, modelling and field measurements were conducted in Quanzhou, China. Two different types of window-opening behaviour were noticed in the tested households. The first type was the all-closed windows, which had an average daily window-opening rate of 0.03%. The second type was the low-intensity window opening. The average daily window-opening rate was 10.6% and 9.1%, respectively. Then, the analysis of point biserial correlation coefficients revealed different reasons for closing windows in low-intensity households. One household closed the windows due to high outdoor humidity and the other mainly due to high outdoor wind speed and outdoor temperature. Furthermore, the suitable hyperparameters were screened for the support vector machine (SVM) model by K-fold cross-validation and grid search. The prediction model achieved an accuracy of 98.5% on the test set. Finally, the SVM model was trained and tested to verify the robustness of the model using data from the published literature. The prediction accuracy was improved from 0.7% to 7.4% compared to the different models used in the published literature.

Numerical simulation analysis of the influence of karst cave orientation and surrounding rock properties on tunnel excavation

Abstract The underground distribution of complex karst geology in the Zhangjiajie region of China poses a significant threat to the construction safety of tunnels, not only increasing project investments but also severely impacting the stable operation of engineering construction. This paper, based on ABAQUS numerical simulation, explores the influence of karst caves around tunnels in different orientations of surrounding rock environments through the rock strength, stress field, and dimension of surrounding rock mass. The results are as follows: (1) With the decrease in cohesive strength of the cave surrounding rock, the stability of the tunnel is enhanced. (2) The maximum displacement of the lower cave is 0.02011 m, greater than that of the side cave, which is 0.01965 m; the maximum principal stress of the lower cave is 7.457 MPa, greater than that of the side cave, which is 7.423 MPa. The lower cave has a greater impact on tunnel construction and can further reduce the stability of the karst tunnel surrounding rock. This paper has researched the influence of caves on tunneling through surrounding rock and investigated the effects of cave orientation, cohesive strength, and other parameters on tunnel construction. It provides theoretical guidance for tunnel alignment and pre-processing of concealed caves.

Digital finance and industrial structure upgrading: Evidence from Chinese counties

The county-level economy holds the potential for future economic growth in China, but traditional finance faces challenges in meeting the needs of county-level economic development and industrial structure upgrading. Digital finance plays a vital role in addressing the challenges faced in county-level development. This study empirically examines the impact and underlying mechanisms of digital finance on industrial structure upgrading using panel data from 1385 counties in China from 2014 to 2020. The empirical results indicate that the development of digital finance significantly promotes industrial structure upgrading, and this finding holds even after conducting a series of robustness tests. Mechanism analysis suggests that digital finance stimulates industrial structure upgrading in the county by fostering entrepreneurial activity and promoting social consumption. Cross-sectional analysis further reveals that the impact of digital finance is more pronounced in regions with lower levels of traditional finance development and efficiency, as well as lower levels of economic development. Additionally, the influence of digital finance diminishes from central to eastern and western regions of China.

Solar-assisted biogas system with air-source heat pump for the energy-saving of indoor heating in north China

Abstract To address the challenges associated with winter heating in high-latitude regions of China, solar-assisted biogas heating systems have emerged as the predominant focus of research due to their cost-effectiveness, accessibility, and environmentally friendly attributes. However, traditional solar-assisted biogas heating systems encounter issues of low efficiency and limited practicality resulting from unstable solar radiation and extreme ambient temperatures during the heating season. To improve the economy and stability of the system, this study proposed a novel operational control method for a small-scale energy station system in rural regions of North China, named Solar-Biomass-Air Source Heat Pump Hybrid Heating System (SBHP-HHS). The integration of solar energy, biogas energy, and air-source heat pump (ASHP) systems in this proposed work has shown to create effective complementarity and enhances the production efficiency of the existing system. Test and simulation studies have been carried out for this system. The layout of buildings and equipment within a university campus in Beijing is reconfigured and redesigned, incorporating an ASHP into the existing heat source configuration. To begin with, a mathematical model is established for the complementary heating system that incorporates solar energy, a biogas digester, and an ASHP. Subsequently, a dynamic simulation model is developed using the TRNSYS platform, and a corresponding operational control strategy for the multi-energy complementary heating system is proposed. Dynamic simulation and analysis of the newly implemented system are performed using the TRNSYS platform, focusing on energy flow and thermodynamic performance. Throughout the heating season, the solar-biogas integrated system achieves a remarkable assurance rate of up to 79%. Additionally, ASHP maintains a relatively high heating efficiency, coefficient of performance (COP) reaches 3.02. Finally, an economic evaluation of the multi-energy complementary system was conducted based on the annual cost method. This was compared with the clean approach of using only an ASHP unit. The results indicate that the SBHP-HHS is more economical when the anticipated useful life is 6 years or longer. The results indicate that the proposed can achieve significant energy-saving and carbon-reduction benefits in rural areas, catering to their heating needs.

Relationship between Vitamin D Concentration and Lipid Concentration in Patients with NAFLD in the Hulunbuir Region of China.

We aimed to characterize the relationship between the serum 25-hydroxyvitamin D concentration and the circulating lipid concentrations of patients with NAFLD in the Hulunbuir region of China. One hundred fifty-six patients, who were diagnosed with NAFLD in the Physical Examination Department of the Second Clinical College of Inner Mongolia University for the Nationalities between January 2021 and March 2023, were recruited as NAFLD group, and 160 healthy people were recruited as a control group during the same period. The serum 25(OH)VitD, TBIL, TG, TC, LDL-C, HDL-C, AST, ALT, GGT, and FPG activities of the participants were measured, and hepatic ultrasonography was performed. The BMI of the NAFLD group was higher than of the control group (p < 0.05). The serum 25(OH)VitD3 (p < 0.05) and the HDL-C concentrations of the NAFLD group were lower than those of the normal control group. However, the AST (p < 0.05), ALT (p < 0.05), and GGT (p < 0.05) activities, and the serum TG (p < 0.05), TC (p < 0.05), LDL-C (p < 0.05), and the fasting glucose (p < 0.05) concentrations of the NAFLD group were higher than those of the normal control group. The serum 25(OH)VitD3 concentrations of the NAFLD group significantly cor-related negatively with BMI (r = -0.302, p < 0.01), TG (r = -0.221, p < 0.05), and fasting glucose (r = -0.236, p < 0.05). The BMI, TG, and fasting glucose of vitamin D-deficient participants were higher than of the participants with adequate or insufficient levels of vitamin D (p < 0.05). Finally, the BMI of vitamin D-deficient participants was higher than of those with an adequate vitamin D status (p < 0.05). A deficiency of 25(OH)VitD is more common in people from the Hulunbuir region of China than elsewhere. In addition, the vitamin D status is significantly associated with NAFLD; as the serum vitamin D concentration decreases, patients with NAFLD show greater dyslipidemia and hyperglycemia and a higher BMI.

Discussion of the classification of pediatric drug clinical trials in children's hospitals in China.

This study aimed to gain insights into pediatric clinical trials conducted in children's hospitals in China and provide valuable references for the development of children's hospitals and the research and development of pediatric drugs. A comprehensive search was performed on the Chinese Clinical Trial Registry (Chi CTR) and ChinaDrugTrials.org.cn to collect information on all clinical trials involving subjects under 18 years, including those conducted in children's hospitals. The retrieval period was extended until 31 December 2022. A total of 459 pediatric clinical trials were collected, comprising 299 from Chi CTR and 160 from the Drug Clinical Trial Registration and Information Publicity Platform (Information Platform). Post-marketing drug studies and phase III clinical trials accounted for the majority of research stages. These trials covered a wide range of diseases/systems, with a particular focus on respiratory system disorders, tumors, endocrine disorders, and nutritional or metabolic diseases. Chemical drugs constituted the most extensively studied category, while traditional Chinese medicine/natural drugs received comparatively less attention. Clinical trial activities were primarily geographically focused on the eastern coastal regions of China, with multicenter trials being the most predominant. Ethics committee approval was obtained for 427 studies. The pediatric clinical trials conducted by children's hospitals in China have shown an overall upward trend; however, there is limited research focusing on traditional Chinese medicine, along with significant regional and institutional imbalances. Furthermore, there is still room for improvement regarding ethical review processes. It is recommended that children's hospitals enhance their scientific research capabilities while optimizing resource allocation to meet medical service demands effectively. Additionally, fostering more research-focused children's hospitals will contribute to the high-quality development of children's health in China.

Patient satisfaction with letter-based communication of LCS pulmonary nodule results.

To analyze patient satisfaction with letter-based communication of lung cancer screening (LCS) pulmonary nodule results. Prospective randomized controlled trial of LCS between May and December 2019. All participants came from a prospective randomized controlled study on pulmonary nodule results in LCS with low-dose CT (LDCT) to analyze patient satisfaction, perception of information received via letters, preferred methods of receiving results, and dissatisfaction-relatedcharacteristics. A total of 153 patients were detected to have pulmonary nodules among 600 recruited participants in the lung cancer high-risk group screened using LDCT. Most of the patients were satisfied with receiving pulmonary nodule results via letters (78.4%; n = 120) and agreed that the letters contained an appropriate amount of information (83.7%; n = 128). Univariate logistic regression analysis revealed that satisfaction was related to age (OR, 0.905; 95% CI, 0.832-0.985), education level (OR, 0.367; 95% CI, 0.041-3.250), no family history of cancer (OR, 0.100; 95% CI, 0.011-0.914), and the number of nodules (OR, 6.028; 95% CI, 1.641-22.141). Of the patients who reported dissatisfaction with letter-based communication (7.2%; n = 11), the most common reasons cited were that they contained insufficient patient education materials and that it was difficult to comprehend the medical terminology. The majority of participants (61.4%; n = 94) reported that they would prefer the letter-based communication. No correlation was identified between satisfaction and gender, smoking status, alcohol consumption, risk factors, nodule size, or nodule location. Patients were generally satisfied with receiving their LCS pulmonary nodule results via letters, reporting that the letters included adequate information about their diagnosis and follow-up steps. This may provide a basis for feasible result communication via letters for cancer screening programs in underdeveloped regions inChina.

Environmental Regulations, Green Technological Innovation, and Green Economy: Evidence from China

With the advancement of the green economy, the influence of the environmental regulations on green technological innovation and the green economy is increasingly expanding. This paper investigates the impact of the environmental regulations and corporate green technological innovation on the green economy. We hope to explore how the environmental regulations affect the green economy through corporate green innovation. Thus, the research aims to enhance our understanding of the impact of the environmental regulations on the green economy. By incorporating the fixed-effects models, mediation models, spatial models, and regression analysis, this paper unveils the impact process of the environmental regulations on the green economy. The research findings are as follows: (1) The environmental regulations show the direct capacity to facilitate the elevation of the green economy. (2) Through the mediating variable of corporate green technological innovation, the environmental regulations could indirectly enhance the green economy. (3) Significant spatial correlations exist between the environmental regulations and corporate green technological innovation activities across the different regions in China. (4) Substantial disparities are evident in the relationships among the environmental regulations, green technological innovation, and the green economy across the various regions in China. The findings presented in this paper serve to broaden the scope of research on the relationship between the environmental regulations and the green economy. Moreover, it offers essential insights for the relevant government authorities and businesses in formulating management policies.

The Impact of the Digital Economy on Carbon Emission Levels and Its Coupling Relationships: Empirical Evidence from China

The development of the digital economy has injected new vitality into the global economy, but the environmental issues it raises cannot be ignored. This paper analyzes the impact of the digital economy on carbon emission levels and their coupling relationships using panel data from 30 provinces, cities, and autonomous regions in mainland China from 2013 to 2021. By employing the coupling coordination degree model and the PVAR model, the study finds that the digital economy in mainland China has shown an upward trend, while carbon emission levels have exhibited a downward trend. The coupling degree between the digital economy and carbon emission levels is relatively good, though the coupling coordination degree is still in its early stages, indicating significant room for development. The digital economy has achieved a positive cumulative effect and can promote itself, and it has a significant negative impact on carbon emission levels.

Varying Drivers of 2013–2017 Trends in PM2.5 Pollution over Different Regions in China

A significant decrease in surface PM2.5 concentrations has been reported since the implementation of the Air Pollution Prevention and Control Action Plan in 2013. In this study, we use the GEOS-Chem model to simulate the trend in surface PM2.5 pollution in China from 2013 to 2017, as well as the relative contributions of emission reduction and meteorology. The simulated decline rate averaged over monitoring sites in China is around −4.7 μg m−3 yr−1 in comparison with the value of −6.4 μg m−3 yr−1 from observations. The model also captures the variations over different regions, with r in the range of 0.85–0.95. Based on the sensitivity tests against emissions and meteorology, the study finds that the decline in PM2.5 concentrations is mainly driven by the reduction in anthropogenic emissions. The variation in open biomass burning (OBB) is not significant, except in Northeast China (NEC) and Pearl River Delta (PRD), where the changes originated from OBB are 40% and 30% of those associated with anthropogenic emission reductions. Changes in meteorology from 2013 to 2017 led to significant increases in PM2.5 concentrations in most areas in China, except in NEC. The increase attributed to meteorology, to a large extent, could be explained by the significant decrease in surface wind speed (WS) and planetary boundary layer height (PBLH) between 2013 and 2017, combined with their negative correlation with PM2.5. The decrease in PM2.5 concentrations in NEC, on the other hand, could be explained by the significant decrease in relative humidity (RH) there combined with the positive correlation of RH with PM2.5, while the changes in WS and PBLH there are relatively small compared with other areas. The change in meteorology, therefore, hinders the improvement of air quality via emission controls in most of China. In Sichuan Basin (SCB), the increase due to meteorology almost compensates for the decrease associated with emission reduction, leading to the least change in PM2.5 concentrations, although the decrease due to emission controls is the largest compared with other areas.

Exploring the Lagged Correlation Between Baidu Index and Influenza-Like Illness - China, 2014-2019.

This study investigated the lagged correlation between Baidu Index for influenza-related keywords and influenza-like illness percentage (ILI%) across regions in China. The aim is to establish a scientific foundation for utilizing Baidu Index as an early warning tool for influenza-like illness epidemics. In this study, data on ILI% and Baidu Index were collected from 30 provincial-level administrative divisions (PLADs) spanning April 2014 to March 2019. The Baidu Index was categorized into Overall Index, Ordinary Index, Prevention Index, Symptom Index, and Treatment Index based on search query themes. The lagged correlation between the Baidu Index and ILI% was examined through the cross-correlation function (CCF) method. Correlating the Baidu Overall Index of 30 PLADs with ILI% revealed CCF values ranging from 0.46 to 0.86, with a median lag of 0.5 days. Subcategory analysis indicated that the Prevention Index and Symptom Index exhibited quicker responses to ILI%, with median lags of -9 and -0.5 days, respectively, compared to 0 and 3 days for the Ordinary and Treatment Indexes. The median lag days between the Baidu Index and the ILI% were earlier in the northern PLADs compared to the southern PLADs. The Prevention and Symptom Indexes show promising predictive capabilities for influenza-like illness epidemics.

A novel machine learning-based artificial intelligence method for predicting the air pollution index PM2.5

Accurate prediction of the Particulate Matter 2.5 (PM2.5) plays a crucial role in the accurate management of air pollution and prevention of respiratory diseases. However, PM2.5 as a time series is extremely difficult to accurately predict. In this paper, a Hybrid Integration (HIG) algorithm that combines data pre-processing, time-series decomposition, signal decomposition, a prediction module, a matching strategy, and a hybrid integrated optimization algorithm is proposed. First, the optimal parameters for the four individual models were selected by integrating multiple evaluation perspectives. Additivity was then determined by Seasonal and Trend decomposition using LOWESS (STL), followed by refinement decomposition using signal decomposition. The four new sequences were reconstructed using Range Entropy (RangeEn) and mapped to the models. Additionally, Recurrent Neural Networks (RNN) and Long Short-Term Memory (LSTM) methods were optimized using the HIG algorithm. The results show that the HIG-RNN and HIG-LSTM are more advantageous than the ordinary method in terms of reasonable weight assignment. Finally, an innovative confusion test method was developed to test the stability of the prediction direction. To ensure generalizability, validation was performed using PM2.5 data from two regions of China. The results show that the method significantly improves the prediction performance and provides a powerful tool for policy formulation and management.

Characteristics of an Inorganic Carbon Sink Influenced by Agricultural Activities in the Karst Peak Cluster Depression of Southern China (Guancun)

Land use in karst areas affects soil properties, impacting carbon sinks. Accurate estimation of carbon sink flux in karst areas through zoning and classification is crucial for understanding global carbon cycling and climate change. The peak cluster depression is the largest continuous karst landform region in southern China, with the depressions primarily covered by farmland and influenced by agricultural activities. This study focused on the Guancun Underground River Basin, a typical peak cluster depression basin, where sampling and analysis were conducted during the agricultural period of 2021–2022. Using hydrochemical analysis and isotopic methods, the results indicated that: (1) The primary hydrochemical type in the Guancun Underground River Basin is HCO₃-Ca, with hydrochemical composition mainly controlled by carbonate rock weathering. (2) The primary sources of Cl−, SO₄2−, and NO₃− are agricultural activities, with agriculture contributing 0.68 mmol/L to dissolved inorganic carbon (DIC), accounting for about 13.86%, as confirmed by ion concentration analysis and isotope verification. (3) The size of the depression area is proportional to the contribution of agricultural activities to DIC, while also being influenced by dilution effects. A comparison was made regarding the contribution of other land use types to DIC. The impact of land use on DIC in karst processes should not be overlooked, and zoning and classification assessments of carbon sink flux under different influencing factors contribute to carbon peaking and carbon neutrality goals.

Functional validation of AaCaM3 response to high temperature stress in Amorphophallus albus

Amorphophallus is a perennial monocotyledonous herbaceous plant native to the southwestern region of China, widely used in various fields such as food processing, biomedicine and chemical agriculture. However, Amorphophallus is a typical thermolabile plant, and the continuous high temperature in summer have seriously affected the growth, development and economic yield of Amorphophallus in recent years. Calmodulin (CaM), a Ca2+ sensor ubiquitous in eukaryotes, is the most important multifunctional receptor protein in plant cells, which affects plant stress resistance by participating in the activities of a variety of signaling molecules. In this study, the key gene AaCaM3 for the Ca2+-CaM regulatory pathway was obtained from A. albus, the sequence analysis confirmed that it is a typical calmodulin. The qRT-PCR results demonstrated that with the passage of heat treatment time, the expression of AaCaM3 was significantly upregulated in A. albus leaves. Subcellular localization analysis revealed that AaCaM3 localized on the cytoplasm and nucleus. Meanwhile, heterologous transformation experiments have shown that AaCaM3 can significantly improve the heat tolerance of Arabidopsis under heat stress. The promoter region of AaCaM3 was sequenced 1,338 bp by FPNI-PCR and GUS staining assay showed that the promoter of AaCaM3 was a high-temperature inducible promoter. Yeast one-hybrid analysis and Luciferase activity reporting system analysis showed that the AaCaM3 promoter may interact with AaHSFA1, AaHSFA2c, AaHSP70, AaDREB2a and AaDREB2b. In conclusion, this study provides new ideas for further improving the signal transduction network of high-temperature stress in Amorphophallus.