Sichuan Research Articles

Two new species and three new records of Diachea (Physarales) from China based on morphological and molecular evidence

Diachea is an important genus of myxomycetes, recognized for its ecological role and wide distribution. This study aimed to expand knowledge of species diversity within this genus in China. We collected Diachea specimens from various locations in Shaanxi and Sichuan provinces and characterized them through morphological analysis and phylogenetic analysis using four genetic markers: small subunit ribosomal RNA (nSSU), translation elongation factor 1-alpha (EF-1α), mitochondrial small subunit (mtSSU), and alpha-tubulin gene (α-Tub). Based on these analyses, we describe two new species, namely, Diachea plectophylla and D. sichuanensis, discovered in the Shaanxi and Sichuan provinces, respectively. Diachea plectophylla is distinguished by its dense, rigid capillitium, spore warts, and distinct separation of capillitium ends from the peridium. Diachea sichuanensis, closely related to D. leucopodia, is identified by its blunt-headed columella, clustered spore warts, and robust stalks. In addition to these new species, we recorded five previously documented species, including D. bulbillosa in Gansu province, D. leucopodia in Yunnan and Sichuan provinces, and D. subsessilis in Sichuan province. Detailed descriptions, micrographs, taxonomic comparisons, and an identification key are provided to aid in accurate identification. The discovery of these new species not only enhances the known diversity of slime molds in the region but also provides valuable information for future studies on their geographical distribution and ecological relationships.

Social support, self-efficacy, self-esteem, and self-management behaviors among people living with HIV/AIDS in China: a structural equation modeling analysis.

Understanding the psychosocial factors influencing self-management behaviors among people living with HIV/AIDS (PLWHA) is crucial for effective medical interventions and improving their quality of life. However, few studies have explored the psychosocial mechanisms influencing self-management behaviors among PLWHA in China. This study, conducted in accordance with STROBE guidelines, uses SEM to explore the roles of social support, self-efficacy, and self-esteem in predicting self-management behaviors among Chinese PLWHA. From March 2023 to July 2023, a convenience sample of 282 PLWHA, recruited from one designated AIDS hospital and one Centers for Disease Control and Prevention in Sichuan Province, China, was surveyed. Data were collected via four validated self-report scales (the Social Support Rating Scale, the General Self-Efficacy Scale, the Self-Esteem Scale, and the HIV/AIDS Patient Self-Management Scale). Structural equation modeling was used to assess the relationships among social support, self-efficacy, self-esteem, and self-management behaviors. The new model demonstrated acceptable fit parameters (χ2/df = 2.15, GFI = 0.96, AGFI = 0.93, CFI = 0.93, IFI = 0.94, RMSEA = 0.05). The direct effect of social support on self-management behaviors was significant (β = 0.117, P < 0.05). In addition, self-efficacy and self-esteem played significant mediating roles in the influence of social support on self-management behaviors, accounting for 38.73% and 22.79% of the total effect, respectively. Moreover, they served as chain mediators, contributing 9.80% to the total effect. These findings contribute to our understanding of the psychosocial dynamics influencing self-management behavior in Chinese PLWHA and have broader implications for populations in other countries. Targeted interventions that enhance social support, self-efficacy, and self-esteem could be applied in various cultural contexts to improve self-management practices among PLWHA globally.

First Report of Powdery Mildew Caused by Golovinomyces ambrosiae on Symphyotrichum subulatum in China.

Symphyotrichum subulatum (Michx.) G. L. Nesom (syn. Aster subulatus), an annual herb in the Asteraceae family, is native to North America. Nowadays, it has become an invasive weed in several provinces of China, including Jiangsu, Zhejiang, and Sichuan (Li and Xie, 2002). Despite being invasive, this species holds significance in Chinese medicine, where it is used for the external treatment of eczema and swollen sore poison (Hu, 2020). In June 2023, symptoms of powdery mildew were observed in S. subulatum populations in Deyang and Nanchong, Sichuan Province, China. About 32.73% among 55 surveyed S. subulatum plants showed signs of infection. Symptoms initially appeared as small, scattered white powdery patches on the leaves, which enlarged and coalesced over time. Subsequently, hyphal growth forming extensive conidia covered up to 90% of the leaf area on both surfaces (Fig. S1A, B), and the infected leaves withered and fell off (Fig. S1A). A specimen was archived at China West Normal University (SsPM-ZL). Conidiophores were cylindrical and erect, 66.4 to 183.2 µm (avg. 108.2±40.8 μm) in length (n=30) (Fig. S1C). Conidia, produced singly, were ellipsoid-ovoid to nearly cylindrical, measuring 29.5 to 36.7 μm in length (avg. 32.9±2.6 μm) and 16.0 to 19.9 μm in width (avg. 17.4±1.3 μm), lacking distinct fibrosin bodies (n=30) (Fig. S1D). Under a scanning electron microscope, turgid conidia displayed reticulate wrinkles on the surface, with gentle contractions or bulges at both poles (Fig. S1E, F). Based on these characteristics, the powdery mildew fungus was consistent with the genus Golovinomyces (Bradshaw et al. 2022a). To confirm the identity of the causal fungus of specimen (SsPM-ZL), the calmodulin (CAM), RNA polymerase II subunit (RPB2), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), glutamine synthetase (GS), and the internal transcribed spacer (ITS) were amplified using PMCAMF/R, PMRPB2F/R, PMGAPDH1/3R, PMGSF/R, and PM5/ITS4 primers (Bradshaw et al. 2022b), and deposited in GenBank (CAM: OR761878; RPB2: OR761881; GAPDH: OR761879; GS: OR761880; ITS: OR758452). BLAST analysis showed 99 to 100% identity with the sequences of Golovinomyces ambrosiae (FH00941234) for CAM (ON101658, 99.65%), RPB2 (ON119165, 100%), GS (ON075690, 99.78%), and ITS (ON073876, 99.47%). Phylogenetic analysis was performed in MEGAX with maximum likelihood method (Kumar et al. 2016) and clustered SsPM-ZL into the G. ambrosiae clade with a 100% bootstrap support value based on the concatenated sequences of CAM, RPB2, GAPDH, GS and ITS (Fig. S2). Combining morphological and phylogenetic analyses, SsPM-ZL was identified as Golovinomyces ambrosiae. To evaluate pathogenicity, leaves of 3 healthy potted S. subulatum plants (3 leaves per plant) were inoculated by gently pressing them with diseased leaves, while 3 non-contact plants were used as control. Plants in two groups were incubated in separate greenhouses maintained at 27±1°C, with a photoperiod of 14 hours and a relative humidity of 80%. After 7 days, the inoculated plants exhibited symptoms of powdery mildew (Fig. S1H, J), while the control plants remained asymptomatic (Fig. S1G, I). Morphological characteristics of the artificially induced powdery mildew were consistent with those on naturally infected plants. Powdery mildew caused by G. ambrosiae has been reported affecting Helianthus tuberosus (Huang et al. 2017) and Bidens pilosa (Mukhtar et al. 2022) in China. To our knowledge, this is the first report of powdery mildew caused by G. ambrosiae on S. subulatum in China. Our finding will provide the fundamental knowledge for future powdery mildew diagnosis and the development of potential control strategies.

Chengba: the Dangqu City of the Han Dynasty in south-west China

Abstract The Chengba site is the only city site dated from the late Warring States Period in eastern Sichuan Province, China. New discoveries of artefacts and structures at the site enable exploration of the regional role and management of counties that were established at this time by the central government.

Parental Influences on Social Competence: An Investigation of Parenting Styles and Children's Social Behavior in Chengdu, Sichuan Province

Parental Influences on Social Competence: An Investigation of Parenting Styles and Children's Social Behavior in Chengdu, Sichuan Province

Prevalence of inhaled allergen sensitization among patients with suspected allergic diseases in Sichuan province: 3-year data from a single center

Allergic diseases are becoming increasingly common, and they are a threat to people’s health. Exploring the distribution characteristics of allergen-specific immunoglobulin E (sIgE) in people from Sichuan province, southwest China, can provide clinical epidemiological data. This study enrolled 12,204 consecutive patients with suspected allergies from May 2018 to May 2021. Among the patients, 4206 were diagnosed with allergic rhinitis or asthma. The Rayto Lumiray 1600 detection system and sIgE and total IgE (tIgE) detection kits were used to measure the levels of nine common sIgE and tIgE. sIgE ≥ 0.35 IU/mL was considered positive. The sensitization rate of D1 (Dermatophagoides pteronyssinus) is the highest (22.97%), followed by D2 (Dermatophagoides farinae) (23.33%); M3 (Aspergillus fumigatus) has the lowest positive rate (1.5%). E5 (Canis familiaris) and I6 (Blatella germanica) exhibited relatively high sensitization rates (8.64% and 12.35%, respectively). Allergen sensitization was significantly higher in men than in women. Moreover, 90.3% of sensitization samples from D1 were combined with at least one of the other eight allergens. Similarly, a positive correlation was demonstrated between D1, D2, and E1 (Felis domesticus). In addition, patients with allergic rhinitis (91.88% and 91.54%, respectively), allergic asthma (72.44% and 74.01%, respectively), and allergic rhinitis with asthma (92.12% and 93.22%, respectively) were mainly sensitized to D1 and D2. D1, D2, I6, and E5 are the main allergens. Moreover, D1 and D2 are the main allergens in patients with respiratory allergic diseases. Research focusing on the distribution of allergens and the characteristics of hypersensitivity in different people helps prevent, diagnose, and treat allergic diseases.

Navigating Urban Risks for Sustainability: A Comprehensive Evaluation of Urban Vulnerability Based on a Pressure–Sensitivity–Resilience Framework

Cities are important symbols of civilization in human society. The vulnerability to cities caused by human activities and natural disasters has become increasingly evident. How to reduce the vulnerability of cities is an important topic in the research of urban public safety and sustainable development. In this study, a comprehensive evaluation of urban vulnerability is conducted on the basis of the pressure–sensitivity–resilience framework from a complex systems perspective, integrating three subsystems—the resource–environment, economic, and social subsystems. On the basis of data from 18 cities in Sichuan Province, China, from 2006 to 2021, this study analyzes vulnerability in terms of its scores, spatial and temporal evolution, and obstacles. The results reveal that the overall vulnerability of the Sichuan Basin has shown a fluctuating downward trend over the past sixteen years, and the spatial distribution has evolved into a large “low-vulnerability” agglomeration. The obstacles affecting urban vulnerability are also changing dynamically and include factors such as the harmless treatment rate of household waste and industrial smoke dust emissions. Drawing from these insights, this study enables the identification and diagnosis of urban vulnerability and, further, provides city managers with tailored recommendations for crafting policies that aim to mitigate risks and promote sustainable development.

Effect of Psychological Resilience on Posttraumatic Growth Among Midwives: The Mediating Roles of Perceived Stress and Positive Coping Strategies.

To explore the relationship between midwives' psychological resilience and posttraumatic growth, and the mediating role of perceived stress and positive coping strategies. A multicentre cross-sectional survey was used. Data were conducted among 339 midwives from 24 Grade III A hospitals in Sichuan Province from April to July 2023, using the Chinese version of the Connor Davidson Resilience Scale, Chinese version Perceived Stress Scale, Simplified Coping Style Questionnaire, Chinese-Posttraumatic Growth Inventory and General Demographic Data Questionnaire. A descriptive statistical approach, Pearson's correlation analysis and the Mplus 8.3 were used to analyse the available data. There was a significant correlation between psychological resilience, perceived stress, positive coping strategies and PTG. Psychological resilience could have a direct positive impact on PTG of midwives, but it could also indirectly affect PTG of midwives through three pathways: the mediating effect of perceived stress, the mediating effect of positive coping strategies and the chain mediating effect of perceived stress and positive coping strategies. Results suggest that nursing managers should help to improve the psychological resilience of midwives and to reduce individual stress perception, enhance coping abilities and achieve positive growth. Prior to data collection, we obtained approval from the nursing department of each hospital. Midwives who met the inclusion and exclusion criteria gave informed consent and invited to participate in this study. This study was guided by STROBE. During the data collection phase, 349 midwives took the time to carefully answer the questionnaire items related to this study.

A Typology and Lead Isotope and Cultural Exchange Study on Bronze Knives from Shuangyuan Cemetery, Chengdu City, Southwest China

Background: Bronze knives, which have been excavated in large quantities and acquired hierarchical significance, are essential artifacts in Shu State in Southwest China. Building upon previous typological analyses of bronze knives, it is hypothesized that Shu culture may have imported foreign-style bronze knives. However, further demonstration of the provenance of metal materials, the typology of knives, and the cultural exchange necessitates a comprehensive examination through the lens of scientific analysis. The purpose of this study is to investigate the differences in the manufacturing processes and metal resources of Shu bronze knives with various cultural styles and whether bronze knives in the foreign styles were imported or locally imitated. Methods: In this study, the typology, portable X-ray fluorescence spectrometry and multi-collector inductively coupled plasma mass spectrometry were used to analyze twenty-four bronze knives unearthed from Shuangyuan cemetery, a cemetery of the Eastern Zhou Dynasty in Chengdu City, Sichuan Province, Southwest China. Results: The results of the study show that the knives of Shuangyuan Cemetery can be classified typologically into five types, encompassing both local and foreign styles. The predominant alloy composition of these knives is lead-tin bronze, characterized by a notably high tin content. Lead isotope ratios indicate that metal materials from the South China geochemical province and Yangtze geochemical province were mainly used to manufacture the bronze knives unearthed from the Shu state Conclusion: While the majority of foreign-style knives with ring-shaped heads were likely imported from neighboring regions like Chu state, distinctively styled type D and type E bronze knives appear to have been locally imitated by the Shu, showcasing a blend of external influences and indigenous innovation. The combination of typology and scientific analysis of the bronze knife may shed new light on the study of the Shu culture of the Eastern Zhou period.

Diagnostic value of CT in patients with stable chronic obstructive pulmonary disease at high altitude: Observational study.

This research aims to explore the diagnostic value of computed tomography (CT) indicators in patients with stable chronic obstructive pulmonary disease (COPD) in a plateau of China, and to find out the correlation between CT indexes and lung function and symptoms. This study screened out 53 stable COPD patients and 53 healthy people through inclusion and exclusion criteria in Hongyuan county, Aba Prefecture, Sichuan Province, between July 2020 and December 2020, and then collected their baseline data, conducted lung function tests and chest CT scans, and collected COPD Assessment Test (CAT), modified Medical Research Council Dyspnea Scale (mMRC) scores. The CT indexes of the 2 groups were compared, binary logistic regression was used to analyze the influence of COPD, the receiver operating characteristic (ROC) curve was used to evaluate the diagnostic value of the CT indexes for COPD. The Spearman test was used to understand the correlation analysis between the CT indexes and lung function, symptom score, and the number of acute exacerbations. Multiple linear regression was used to analyze the influencing factors of lung function. The percentage of low-attenuation areas less than -950 Hounsfield units (%LAA-950; t = -4.387,P = 0), percentage of wall area (WA%; t = -4.501, P = 0), and thickness-diameter ratio (TDR; t = -4.779, P = 0) in the COPD group were higher than those in the normal group. ROC shows that: %LAA-950 (P = .047) and TDR (P = .034) were independent influence in COPD in the plateau. %LAA-950 combined with TDR (AUC = 0.757, P < .001) had the value of diagnosis of COPD in the plateau. All 3 indexes are negatively correlated with lung function, and positively correlated with the symptoms and the number of acute exacerbations. Multiple linear regression analysis showed that the main factors for decrease of ratio of measurement to prediction of forced expiratory volume to the first second (FEV1%) included %LAA-950 (OR = -0.449, P < .001) and WA% (OR = -0.516, P < .001). CT indexes have a certain diagnostic value in patients with stable COPD at high altitude.

Prevalence and genetic evolution analysis of porcine epidemic diarrhea virus and porcine circovirus type 2 in Sichuan Province, China, from 2023 to 2024

IntroductionPorcine circovirus type 2 (PCV2) and Porcine epidemic diarrhea virus (PEDV) are highly prevalent in Sichuan, significantly affecting the swine industry’s development. PCV2, known for its immunosuppressive effects, can compromise pigs’ immune systems, while PEDV typically causes diarrhea in piglets, leading to high mortality rates. Despite their impact, recent studies on the epidemiology and genetic diversity of PCV2 and PEDV within Sichuan Province remain limited.MethodsThis study examines clinical samples from 352 diarrheal piglets across 63 pig farms in 17 regions of Sichuan Province, revealing positivity rates of 42.33% (149/352) for PCV2 and 50.28% (177/352) for PEDV, with a co-infection rate of 27.56% (97/352). Notably, the highest positivity rates were observed in Ziyang for PCV2 at 61.90% (13/21), and in Meishan for PEDV at 73.81% (31/42), both regions also reported the highest co-infection rates of 47.62%.Results and discussionSeasonal analysis indicated that PEDV infections peaked during winter, whereas PCV2 showed no significant seasonal trends. Phylogenetic analysis identified 14 PCV2 strains, categorizing 2 as PCV2b (14.29%), 10 as PCV2d (71.43%), and 2 as PCV2e (14.29%). Among the 16 PEDV strains, 2 were classified as G1a (12.5%) and 14 as G2a (87.5%), with PCV2d and PEDV G2a identified as the predominant strains in the region. The study also highlights a high mutation rate at the antigenic sites of both viruses, potentially affecting vaccine efficacy. These findings underscore the need for ongoing surveillance and vaccine development tailored to the prevalent strains to improve control measures within the province.

Cow Milk Fatty Acid and Protein Composition in Different Breeds and Regions in China

Cow milk is rich in proteins, fats, carbohydrates, and minerals; however, its precise nutrient content varies based on various factors. In the current study, we evaluated the differences in the fatty acid and protein contents of milk and the factors associated with these differences. To achieve this, samples were collected from seven types of cows in different regions. These included samples from three dairy breeds: Chinese Holstein milk from Beijing, China (BH), Chinese Holstein milk (HH) and Jersey milk (JS) from Hebei province, China; and four dairy/meat breeds: Sanhe milk (SH) from Inner Mongolia Autonomous Region, China, Xinjiang brown milk (XH) and Simmental milk (SI) from Xinjiang Uygur Autonomous Region, China, and Shu Xuanhua milk (SX) from Sichuan province, China. Breed significantly affects total fat, fatty acid, and protein contents. Additionally, geographic region significantly affects the contents of different fatty acids, α-lactalbumin, and lactoferrin. JS has the highest total fat and casein contents. XH samples contain significantly higher unsaturated fatty acid content than BH samples and do not differ significantly from JS. Additionally, the low β-lactoglobulin and high lactoferrin contents in XH samples may be favorable for the growth and development of infants. Our results may inform the development of dairy products from different cow breeds and advance the process of accurate breed identification.

A hybrid model based on novel SVM-SVR and weighted combination strategy for build-up rate prediction

Abstract The build-up rate prediction is of great importance for trajectory control in the field of drilling. However, it is very difficult to achieve accurate prediction due to the complexity, nonlinearity, and multiple uncertainties of the drilling system. As a consequence, a novel hybrid prediction model is proposed, which uses multiple feature selection methods, the model combination strategy based on machine learning, and three prediction models to improve the prediction accuracy of the build-up rate. More precisely, correlation analysis, importance analysis, and statistical analysis are employed to ensure the effectiveness of feature selection. Then, a novel classification prediction model called support vector machine-support vector regression (SVM-SVR) is proposed to improve the accuracy of samples with the higher build-up rate. Subsequently, the SVR optimized by grey wolf optimizer (GWO-SVR) and back propagation (BP) neural network are constructed. Finally, the three models are integrated by a weighted combination method based on SVR to realize the accurate prediction of the build-up rate. To verify the performance of the hybrid model, the data of the Z48 well in Sichuan province is used, and the results show that the hybrid model can reduce by 22.7% in mean absolute error and 32% in mean square error when compared with the existing models.

Childhood emotional maltreatment affects depression of adolescents with mood disorders: the mediating role of functions of non-suicidal self-injury

BackgroundChildhood emotional maltreatment, non-suicidal self-injury and depression are prevalent among adolescents with mood disorders. While existing model indicated that childhood emotional maltreatment, functions of non-suicidal self-injury and depression are interrelated, not much is understood about the interplay of functions of non-suicidal self-injury in the relationship between childhood emotional maltreatment and depression. Thus, the goal of this research was to ascertain how functions of non-suicidal self-injury relate to childhood emotional maltreatment and depression.MethodsThe participants were adolescents with mood disorders from three hospitals in Sichuan Province, data was collected using self-administered questionnaires, including the Childhood Trauma Questionnaire, Ottawa Self-injury Inventory-Functions, and Childhood Depression Inventory. SPSS26.0 software and PROCESS v3.3 model 4 were used for analysis.ResultsIn all, 235 adolescents (Mage=14.8, SD = 1.62) participated in the research. The functions of non-suicidal self-injury (r = 0.289, P < 0.01) and depression (r = 0.475, P < 0.01) were considerably positively connected with childhood emotional maltreatment, and the functions of non-suicidal self-injury were strongly positively correlated with depression (r = 0.364, P < 0.01). The direct impact of childhood emotional maltreatment on depression in adolescents was found to be significant (95% CI 0.434, 0.828) in the mediated effects model. Additionally, the indirect effect of childhood emotional maltreatment on depression through functions of non-suicidal self-injury was found to be significant (95% CI 0.055, 0.236), with a mediating effect value of 17.58%.ConclusionChildhood emotional maltreatment has a direct impact on depression, but it also has an indirect influence through mediation roles of functions of non-suicidal self-injury. Medical staff should take care of the mental health of adolescents hospitalized for mood disorders so that they can clarify the role of functions of NSSI in lowering depressive symptoms and improving quality of life and create more targeted and effective intervention plans.

The Professional Development of Primary School Teachers in Rural China

The professional development of rural teachers is not only related to their personal growth, but also directly affects the improvement of rural education quality and the future development of rural students. Although the professional development of rural teachers is highly valued in today's society, there is still an issue of unequal education resources and investment between urban and rural areas in China. This study aims to determine the professional development of primary school teachers in rural China. This study used a questionnaire survey method to determine the career development in rural China. 600 teachers will be randomly assigned to 50 rural primary schools in Sichuan Province. After collecting data, this study will use SPSS for analysis to measure the professional development of participants. This has potential impacts on both policy and practice. In addition, this study provides a solid evidence foundation for policy-making on training opportunities.

Periodontal conditions and salivary microbiota are potential indicators to distinguish silicosis: an exploratory study

BackgroundSilicosis has always been a serious global occupational health problem. Oral microbiota plays important roles in the development of lung disease. However, few studies have investigated the relationship between periodontal conditions, oral bacteria and silicosis disease.MethodA single-center and cross-sectional study was conducted in 2019 in Sichuan Province, China, including a small sample of silicosis patient group and healthy control group. Demographic data and periodontal examinations measured by clinical attachment loss (CAL), bleeding on probing (BOP) and periodontal pocket (PD) were collected from each participant. Phenotypic changes were detected by histopathological staining. Next-generation sequencing targeting 16S ribosomal RNA was targeted to decipher the salivary microbiome of the two groups. Random forest, Least Absolute Shrinkage and Selection Operator (LASSO) logistic regression and multivariable logistic regression analysis were conducted to find potential indicators to distinguish silicosis.ResultsIn general, 29 male healthy controls and 24 male silicosis patients were included. The proportion of CAL ≥ 3 mm in silicosis group was greater than control group, while the proportion of BOP (+) and PD ≥ 4 mm was reduced in silicosis group. The α-smooth muscle actin and fibronectin expression increased in gingiva of patients. The composition of salivary microbiota exhibited significant differences between the two groups, with silicosis patients demonstrating a lower diversity of salivary microbiota. Genus of Aggregatibacter [odds ratio (OR) = 0.000, p = 0.003] and Catonella (OR = 0.000, p = 0.049) were identified as biomarkers to distinguish silicosis.ConclusionsThe silicosis group exhibited worse CAL, improved BOP and PD, which may be related to the gingival fibrosis found in this study. The composition of the oral microbiota underwent significant changes, accompanied by a decrease in diversity, in patients with silicosis. Our study indicates that respirable crystalline silica exposure affects oral health, and alterations of oral microbiota might be implicated in silicosis. We primarily identified Aggregatibacter and Catonella as the potential indicators to distinguish silicosis patients from healthy controls.

A 3D DEM modeling of soil-rock mixture considering spatial distribution orientation of blocks

Spatial distribution orientations of blocks can cause significant errors in the discrete element model (DEM) calculation of soil-rock mixture (SRM). To avoid this error, spherical harmonic (SH) series whose harmonization degrees fixed at 15 were proposed for block reconstruction. This research refers to the case-history of a deep excavation rift valley spanning from the Mabian to Zhaojue section of the Leshan-Xichang Expressway, mainly containing moderately-weathered silty mudstone, in the Leshan City, Sichuan Province, China. The appropriate degree of finite-term SH series is selected by the volume, surface area. 100 blocks were scanned on site, and sphericity and angularity of the blocks were calculated. The sphericity and angularity of 50 reconstructed blocks were considered for the error analysis of SH method. Moreover, stochastic polyhedron method was considered for comparing different block reconstructions. The maximum block placement angle was defined to control the spatial distribution orientations of the blocks. Large scale direct tests were carried. Numerical simulations of large-scale direct shear tests were conducted to study the influence of the spatial distribution orientations of the blocks on the mechanical properties of the SRMs. The results revealed that the finite-term SH series fixed at 15 accurately reflected the shape characteristics and mechanical behaviors of actual blocks. The spatial distribution orientations of the blocks had a minimal impact on the friction angle and cohesion of SRM constructed through the SH method. The SRMs developed via the SH method exhibited marginal variations in contact force and anisotropy index of contact across diverse block placement strategies. The evolution of coordination number was closer when employing the SH method under varied block placement methods. Blocks reconstructed by the SH method, could mitigate errors in DEM calculation caused by the spatial distribution orientations of the blocks.

Study on the Damage Characteristics of Red Sandstone Foundation Under Rainfall Infiltration in the Red-Bed Area of the Sichuan Basin—Taking Zhongjiang County as an Example

The Sichuan Basin in China is one of the most concentrated areas of red beds in China. In the red-bed area, abundant rainfall can easily cause natural disasters, such as landslides, mudslides, collapses, and subsidence. This has had a great impact on the safety of people and property and sustainable modernization in the area. Zhongjiang County of Sichuan Province is a typical red-bed area, and red sandstone is one of the main foundation rocks in this area. Under the influence of rainfall, the strength of red sandstone foundation easily decays, causing disasters such as house collapse. Therefore, in order to explore the influence of rainfall on the mechanical properties of red sandstone, this paper takes the red sandstone in Zhongjiang County, Sichuan Province, China, as the research object and conducts acoustic-emission uniaxial compression experiments under different water contents. The strength characteristics, instability precursor characteristics, fracture types, and damage characteristics of red sandstone in different water-bearing states are obtained. The abovementioned results provide a reference for the Zhongjiang County Government to consider the impact of rainfall on the red sandstone foundation during modernization and emergency management.

A Study of the Mechanisms of Government Embedment and Organizational Environment Related to Supervisory Effectiveness in the Collective Governance of Rural Residential Land

Rural Residential Land is a kind of public pond resource, and the implementation of the collective governance of Rural Residential Land is a response to the dilemma of utilizing the land. This paper takes the attribute of using Rural Residential Land as a public pond resource as an entry point, draws on Autonomous Governance Theory, and utilizes the OLS model and the mediated effect model to explore the influence of Government Embedment on supervisory effectiveness in the collective governance of Rural Residential Land, based on the fieldwork data of 450 farming households in three districts (cities and counties) in Sichuan Province. This study shows that Government Embedment, the Technological Environment and the Cultural Environment can significantly enhance supervisory effectiveness in the collective governance of Rural Residential Land, while the Resource Environment has a negative effect on it. The Resource Environment has a masking effect on the influence of Government Embedment on supervisory effectiveness in the collective governance of Rural Residential Land, while the Technological Environment and the Cultural Environment play a part in the mediating effect. The anonymous whistleblowing mechanism positively moderates the influence of the Technological and Cultural Environments on supervisory effectiveness. Additionally, there is obvious locational heterogeneity in the influence of Government Embedment and the Organizational Environment on supervisory effectiveness. Therefore, a coordinated supervision and sanctioning mechanism should be constructed in towns and villages to promote the integration and complementarity of formal and informal systems; a sound mechanism for anonymous reporting of illegal and irregular use of Rural Residential Land should be established; and the effective implementation of the collective governance of Rural Residential Land should be promoted in accordance with the differences in the location of the villages.

A Case Study on the Integration of Remote Sensing for Predicting Complicated Forest Fire Spread

Forest fires can occur suddenly and have significant environmental, economic, and social consequences. The timely and accurate evaluation and prediction of their progression, particularly the spread speed in difficult-to-access areas, are essential for emergency management departments to proactively implement prevention strategies and extinguish fires using scientific methods. This paper provides an analysis of models for predicting forest fire spread in China and globally. Incorporating remote sensing (RS) technology and forest fire science as the theoretical foundation, and utilizing the Wang Zhengfei forest fire spread model (1983), which is noted for its broad adaptability in China as the technical framework, this study constructs a forest fire spread model based on remote sensing interpretation. The model improves the existing model by adding elevation an factor and optimizes the method for acquiring certain parameters. By considering regional landforms (ridge lines, valley lines, and slopes) and vegetation coverage, this paper establishes three-dimensional visual interpretation markers for identifying hotspots; the orientation of the hotspots can be identified to simulate the spread of the fire uphill, downhill, in the direction of the wind, left-level slope, and right-level slope. Then, the data of Sentinel-2 and DEM were used to invert the fuel humidity and slope of pixels in the fire line areas. The statistical inversion data from pixels, which replaced fixed-point values in traditional models, were utilized for predicting forest fire spread speed. In this paper, the model was applied to the case of a forest fire in Mianning County, Sichuan Province, China, and verified using high-time-resolution Himawari-8 data, Gaofen-4 data, and historical data. The results demonstrate that the direction and maximum speed of fire spread for the fire lines in Baifen Mountai, Jiaguer Villageand, Muchanggou, Xujiabaozi, and Zhaizigou are uphill, 16.5 m/min; wind direction, 17.32 m/min; wind direction, 1.59 m/min; and wind direction, 5.67 m/min. The differences are mainly due to the locations of the fire lines, moisture content of combustibles, and maximum slopes being different. Across the entire fire line area, the average rate of increase in the area of open flames within one hour was 3.257 hm2/10 min (square hectares per 10 min), closely matching the average increase rate (3.297 hm2/10 min) monitored by the Himawari-8 satellite in 10 min intervals. In contrast, conventional fixed-point fire spread models predicted an average rate of increase of 3.5637 hm2/10 min, which shows a larger discrepancy compared to the Himawari-8 satellite monitoring results. Moreover, when compared to the fire spot monitoring results from the Gaofen-4 satellite taken 54 min after the initial location of the fire line, the predictions from the RS-enabled fire spread model, which integrates remote sensing interpretations, closely matched the actual observed fire boundaries. Although the predictions from the RS-enabled fire spread model and the traditional model both align with historical data in terms of the overall fire development trends, the RS-enabled model exhibits higher reliability and can provide more accurate information for forest fire emergency departments, enabling effective pre-emptive measures and scientific firefighting strategies.