New glucosidated indole-quinazoline alkaloids from mangrove endophytic fungus Aspergillus fumigatus SAl12.

Two new glucosidated indole-containing quinazoline alkaloids designated fumigatosides G (1) and H (2) were isolated from mangrove-derived fungus Aspergillus fumigatus SAl12, together with the known analogues fumigatoside B (3) and fumiquinazoline J (4). The planar structures of the new compounds were elucidated by HR-MS and NMR spectroscopic data analyses. The absolute configurations were determined by comparison of electronic circular dichroic (ECD) spectra with that of the known compound fumigatoside B and with the calculated ECD spectrum. All these indole-quinazoline compounds were tested for anti-bacterial and cytotoxic activities.

Energy Consumption Structure and Influencing Factors of Farmers in China from the Perspective of Labor Transfer.

Under the background of carbon peak and carbon neutralization, the transformation and upgrading of energy consumption structure is crucial to achieve sustainable environmental development. Based on the questionnaire data of 1080 farmers in Sichuan province in 2021, the IV-Probit model was used to explore the impact of labor from off-farm employment on farmers' energy consumption structure and its specific mechanism. The results show the following: (1) the overall proportion of off-farm employment is not high, only 23%; in cooking energy, the most farmers use high-quality energy, accounting for up to 94%; (2) in addition to high-quality energy, off-farm employment of labor force is positively and significantly correlated with the remaining six types of energy consumption structure. The results of a heterogeneity analysis show that the proportion of off-farm employment of farmers with a high education level and above has the greatest positive effect on the use of high-quality energy; (3) the results of the mediating effect show that the off-farm employment can affect the energy consumption structure of farmers through the two paths of annual cash income and population structure.

Will farmers follow their peers in adopting straw returning? Evidence from rural Sichuan Province, China.

From the perspective of conformity tendency, based on 540 farmers' data in Sichuan Province, China, the study used the probability score matching (PSM) model and mediator model to explore the role of four types of peers' straw returning behavior on farmers' preferences to implement straw returning and the realization paths. It was found that (1) farmers' preferences to implement straw returning were influenced by the straw returning behavior of neighbors, relatives, wealthy villagers, and village cadres, i.e., there were conformity tendencies in farmers' straw returning decisions. (2) The degree of conformity tendencies formed by different peers varied. Among the peers affecting farmers' preferences to implement straw returning, the effect of village cadres was the largest, followed by neighbors, relatives, and the wealthy villagers. (3) The degree of conformity tendencies varied by decision-makers. The younger and less educated the farmers were, the more willing they were to adopt straw returning driven by their neighbors, relatives, wealthy villagers, and village cadres. (4) In the conformity tendencies (including conformity to neighbors, relatives, wealthy villagers, and village cadres) of straw returning, farmers' perceptions of income benefits and environmental benefits played a significant mediating role, and the perception of environmental benefits was more vital.

Does labor transfer affect rural household cooking fuel choice? Examining the role of income.

It's the direction of all humankind's joint efforts to develop clean cooking fuels and reduce carbon emissions vigorously. While most studies found that householder and family characteristics influence household cooking fuel choice, few studies focus on the relationship between labor transfer and the choice of clean cooking fuels. Based on the three-phase survey data of the China Labor-Force Dynamic Survey in 2012, 2014, and 2016, this paper analyzes the influence of labor transfer on rural households' cooking fuel choice. It focuses on the mediating role of income and the heterogeneity of labor transfer on household cooking fuel choice under different educational levels and location conditions. The results show that (1) from 2012 to 2016, there are regional differences in the development of clean cooking fuels; (2) labor transfer can promote households to choose clean cooking fuels, and this result remains robust after controlling for endogeneity; (3) labor transfer indirectly influences household cooking fuel choice through affecting family income; and (4) the impact of labor transfer on household cooking fuel choice varies with different education levels and location conditions. Therefore, analyzing the optimization of rural cooking energy structure from the perspective of labor transfer plays an important role in ensuring the sustainable development of clean cooking fuels in rural areas.

Spatial and Temporal Patterns of Ecological Connectivity in the Ethnic Areas, Sichuan Province, China.

With ongoing economic and social development, natural habitats are becoming increasingly fragmented, blocking habitat connections and reducing landscape connectivity. The study of changes in ecological connectivity can provide valuable information for habitat and landscape restoration, which are necessary for sustainable regional development. Despite the growing interest in this issue, studies that reveal the change in ecological connectivity in the compounded areas of ecological vulnerability and deep poverty are still lacking. In this paper, one of the most underdeveloped and ecologically fragile southwestern ethnic regions of China, the Sanzhou region of Sichuan Province, was the study area. Based on a vector map of current land-use status and vector data on ecosystem factors and nature reserves in 2010 and 2015, the change in ecological connectivity was analyzed using the minimum cumulative resistance model using GIS spatial analysis method. Firstly, ecological sources were identified based on the distribution of ecological functional areas. Secondly, the ecological resistance surface based on ecosystem service value is revised by integrating the three dimensions of topography and hydrology, ecological environment and development, and utilization intensity. Finally, the ecological connectivity of ethnic areas in southwest China in 2010 and 2015 was compared and analyzed through the perspective of ecological resistance. The results show that: (1) From 2010 to 2015, the overall ecological connectivity decreased. (2) There were six areas of high ecological resistance featuring human activity and ecological degradation: the Anning River Valley in Liangshan Prefecture, Ganzi, Dege and Luho counties in Ganzi Prefecture, and Ruoergai and Hongyuan counties in Aba Prefecture. (3) Low ecological resistance areas were more numerous and widely distributed, forming an ecological protection barrier for the three autonomous prefectures, and regulating and protecting their natural environments. It is necessary to maintain and strengthen this protection; accordingly, measures are proposed to improve ecological connectivity. This study provides a reference for achieving ecological security and harmonious coexistence between humans and nature in this region.

Influence of anxiety on university students' academic involution behavior during COVID-19 pandemic: Mediating effect of cognitive closure needs.

The COVID-19 pandemic has had a significant negative effect on university students' mental health worldwide. The pandemic has resulted in individuals experiencing increased levels of anxiety and stress as well as intensified concerns about the future due to a rise in uncertainty. To eliminate the anxiety and stress caused by uncertainty, individuals who have high cognitive closure needs are strongly motivated to achieve certainty and seek answers, even if the decisions they make in the process are inappropriate or even irrational. This study attempts to analyze the influence of anxiety and stress on university students' academic involution behavior during the COVID-19 pandemic through the mediating effect of the need for cognitive closure. Analyzing the survey data collected from 402 university students from 3 different universities through the mediating effect model and path analysis with latent variable (PA-LV), our results indicate that: (1) The COVID-19 pandemic has significantly increased the levels of anxiety and stress experienced by university students. The path coefficient of the perceived risk of contracting COVID-19 to perceived emotions (including anxiety and stress) was 0.352 (p < 0.01), (2) anxiety and stress significantly and positively affect academic involution behavior. For each unit of increase in the scores of anxiety and stress, the scores of academic involution behavior increased by 0.408 (p < 0.01) and 0.398 (p < 0.01) units, respectively, and (3) The need for cognitive closure had a complete and partial mediating effect on the relationship between the perceived risk of contracting COVID-19 and academic involution behavior, as well as anxiety and academic involution behavior, respectively. The results of PA-LV showed that the mediating effect values were 0.106 and 0.044, respectively. The impact of the COVID-19 pandemic has not yet come to an end and so clarifying the relationship between anxiety and academic involution behavior will assist university students to optimize the relationship in their own subjective situations, to establish good learning habits, and reduce psychological distress.

Effects of Conformity Tendencies on Farmers' Willingness to Take Measures to Respond to Climate Change: Evidence from Sichuan Province, China.

Encouraging farmers to respond to climate change is very important for agricultural production and environmental governance. Based on the data of 540 farmers in Sichuan Province, China, the effects of conformity tendencies on farmers' adaptive behavior decisions to climate change were analyzed using the binary logistic model and propensity score matching method (PSM). The results show that (1) relatives' and friends' adaptive behaviors to climate change positively affect farmers' adaptive behaviors to climate change. (2) Compared with relatives and friends who do not visit each other during the New Year (weak ties), the climate change adaptation behavior of relatives and friends who visit each other during the New Year (strong ties) has a more significant impact on the climate change adaptation behavior of farmers. (3) Farmers with higher education levels and agricultural products without disaster experience are more significantly affected by peer effects and more inclined to take measures to respond to climate change. (4) Social networks and social trust play a partially mediating role in the peer effects of farmers' adaptation to climate change, but there are differences between relatives and friends with different strong and weak ties.

Structural evolution of soil aggregates in a karst rocky desertification area.

Desertification and karst landforms are widespread in the water source area of the middle route project of south-to-north water diversion in China. Soil erosion processes directly influence water quality in the water source area and contribute sediments to the bottom of the water reservoir. This study investigates soil evolution over time by sampling a slope surface and discusses associated changes in soil structure, physical and chemical properties, and mineral associations. Changes in soil aggregate structures with slope surface direction and mineral association evolution are observed. The compositions of the main soil minerals and elements are determined using scanning electron microscopy, and X-ray energy spectrum and X-ray diffraction analyses. The results reveal that (1) the evolution of soil aggregates is consistent with evolutionary trends in soil elements and mineral associations. (2) The ultra-microstructure of soil aggregate indicates the soil development stage and condition, while mineral associations indicate the soil development stage along the soil chronosequence. This study increases the understanding of land surface processes in the study area and the soil development, forming and biogeochemical processes in karst rocky desertification areas.

Spatial-Temporal Features and Correlation Studies of County Rural Hollowing in Sichuan.

The research on rural hollowing is necessary for policy making related to rectifying hollow villages in the Rural Revitalization Strategy. In this context, Sichuan was chosen as a typical region to explore the spatial-temporal features and relevant factors of rural hollowing. The results show that (1) from 2010 to 2018, rural hollowing shows a downward trend. The average of comprehensive hollowing dropped by 0.028, and 119 counties have a decrease in the degree of comprehensive hollowing. (2) During the same study period, the regional characteristics of the rural hollowing degree were significant. High and higher degrees of comprehensive hollowing have an obvious decrease in number and have a trend of agglomeration in Central Sichuan. High and higher degrees of land hollowing have an obvious decrease in number, and they were mainly distributed in Northwest Sichuan in 2018. The degree of population hollowing gradually increases from west to east, and high and higher degrees of population hollowing have a significant increase in number, mainly concentrated in East Sichuan. The degree of economic hollowing has obvious spatial characteristics from west to east, and high and higher degrees of economic hollowing have an increase in number, mainly concentrated in Chengdu Plain. (3) During the same study period, the spatial distribution characteristics of rural hollowing degree at the county level in Sichuan Province were obvious. The high-value clustering is mainly concentrated in Chengdu Plain Economic Zone, and the range of clustering is decreasing. Low-value clustering was mainly distributed in Northeast Sichuan Economic Zone and Northwest Sichuan Economic Zone. (4) Rural hollowing in Sichuan Province is negatively correlated with average elevation and per capita arable land area; rural hollowing is positively correlated with urbanization rate and industrial output value.

Internet use and land transfer in: empirical evidence from China's rural panel data.

In the context of the Internet power strategy, "Internet + agriculture" has gradually become a key force in realizing agricultural modernization. Based on the data of the China Labor-force Dynamics Survey 2012, 2014, and 2016, this paper uses conditional mixed process (CMP) to solve the endogeneity problem and tests the impact and mechanism of Internet use on farmers' land transfer in. The results showed that (1) from 2012 to 2016, the proportion of farmers using the Internet increased in turn, while the proportion of farmers transferring in land decreased in turn. (2) Farmers' Internet use is significantly negatively correlated with land transfer in. In 2012, 2014, and 2016, each unit increase in the proportion of farmers' Internet use reduces the probability of land transfer in by 2.6%, 10.7%, and 20.8%, respectively. (3) The analysis of mediating effects shows that the Internet can promote land transfer in by expanding social networks and inhibit land transfer in by improving the stability of non-agricultural employment, and both are partial mediating effects. From the micro-perspective of farmers' Internet use, this study can strengthen our understanding of Internet use and land transfer behavior decision-making and then provide a reference for rural digitalization construction and land transfer-related policy making.

Peer Effects on Farmers' Purchases of Policy-Based Planting Farming Agricultural Insurance: Evidence from Sichuan Province, China.

The tendency to conform with peers, and learning by imitation, have become new influencing factors that affect farmers' purchases of policy-based planting agricultural insurance. Based on the survey data of 540 farmers in Sichuan Province in 2021, this study empirically analyzed the impact of peer effects on farmers' purchases of policy-based planting agricultural insurance and its mechanism. The results show that: (1) Regardless of whether farmers' relatives and friends visit during the New Year period, the purchase of policy-based planting agricultural insurance by relatives and friends will positively and significantly affect the purchasing behavior of the farmers. (2) The impact of the peer effect on the behavior of farmers purchasing policy-based planting agricultural insurance is related to the relationship between the strengths and weaknesses. (3) The results of the mechanism analysis show that, through the mediating variables of social network and trust, the influence of the peer effect is weakened. (4) Heterogeneity analysis shows that farmers having a larger land scale and higher educational background are more influenced by the same peer effect. The results of the study emphasize the importance of the peer effect on the behavior of farmers purchasing policy-based planting agricultural insurance, and can provide a decision-making reference for the formulation of related policies.

Peer effects on the adoption of biogas in rural households of Sichuan Province, China.

Encouraging rural residents to adopt biogas is of great practical significance in tackling environmental degradation in China. Based on the survey data of 540 rural households in Sichuan Province, China, this paper studies the peer effects of biogas adoption in rural households, focusing on the influence of relatives and friends on the biogas adoption behavior of rural households. According to whether there is a Chinese New Year visit, the relatives and friends of rural households are divided into strong ties and weak ties. The peer effects are further discussed from the perspective of strong and weak ties, and the probability score matching (PSM) method is used to correct the estimation errors that may be caused by selection bias. In addition, the study further revealed the internal mechanism of peer effects through heterogeneity analysis. The results found that (1) the adoption of biogas by relatives and friends significantly promotes the adoption of biogas in rural households. (2) Compared with relatives and friends who did not visit during the Chinese New Year (weak ties), relatives and friends who visited (strong ties) had a more significant impact on the biogas adoption behavior of rural families. (3) Farmer groups with lower education levels and farther from the market are more affected by the peer effects and are more likely to adopt biogas. The driving effect of biogas behavior choice of relatives and friends on biogas behavior decision of rural households can provide a reference for decision-makers to make relevant measures.

Stay in Risk Area: Place Attachment, Efficacy Beliefs and Risk Coping.

For residents living in earthquake-threatened areas, choosing suitable risk coping behaviors can effectively reduce the loss of family life and property. However, some residents still choose to continue to live within areas at risk of earthquake disaster. Place attachment may play an important role. Based on place attachment theory and the Protective Action Decision Model (PADM), this study explores the possible relationships among place attachment, efficacy beliefs, and evacuation/relocation intention. Furthermore, it examines the mediating role of efficacy beliefs. The study also used the partial least squares method (PLS-SEM) to test samples of 327 rural households in Wenchuan and Lushan earthquake-hit areas. The results show that: (1) Place attachment has a significant effect on response efficacy (RE), but not on self-efficacy (SE); (2) Place dependence (PD) has a negative and significant effect on relocation intention (RI) but has no significant effect on evacuation intention (EI). However, place identity (PI) can indirectly affect EI by influencing RE; (3) Efficacy beliefs have a significant positive effect on EI and RI. These results help us understand the complex relationships among place attachment, efficacy beliefs, and residents' risk coping behavior, thus providing decision-making references for the formulation and improvement of regional disaster risk management policies.

Potent Anticancer Activities of Beauvericin Against KB Cells In Vitro by Inhibiting the Expression of ACAT1 and Exploring Binding Affinity.

BACKGROUND AND OBJECTIVE: Beauvericin (BEA), a cyclic hexadepsipeptide mycotoxin, is a potent inhibitor of the acyl-CoA: cholesterol acyltransferase enzyme 1 (ACAT1), involved in multiple tumor-correlated pathways. However, the binding mechanisms between BEA and ACAT1 were not elucidated. METHODS: BEA was purified from a mangrove entophytic Fusarium sp. KL11. Single-crystal X-ray diffraction was used to determine the structure of BEA. Wound healing assays of BEA against KB cell line and MDA-MB-231 cell line were evaluated. Inhibitory potency of BEA against ACAT1 was determined by ELISA assays. Molecular docking was carried out to illuminate the bonding mechanism between BEA and ACAT1. RESULTS: The structure of BEA was confirmed by X-ray diffraction, indicating a monoclinic crystal system with P21 space group (α = 90°, ß = 92.2216(9)°, γ= 90°). BEA displayed migration-inhibitory activities against KB cells and MDA-MB-231 cells In Vitro. ELISA assays revealed that the protein expression level of ACAT1 in KB cells was significantly decreased after BEA treatment (P ＜0.05). Molecular docking demonstrated that BEA formed hydrogen bond with His425 and pi-pi staking with Tyr429 in ACAT1. CONCLUSION: BEA sufficiently inhibited the proliferation and migration of KB cells and MDA-MB-231 cells by downregulating ACAT1 expression. In addition, BEA potentially possessed a strong binding affinity with ACAT1. BEA may serve as a potential lead compound for the development of a new ACAT1-targeted anticancer drug.

Social Networks, Trust, and Disaster-Risk Perceptions of Rural Residents in a Multi-Disaster Environment: Evidence from Sichuan, China.

Individual perception of disaster risk is not only the product of individual factors, but also the product of social interactions. However, few studies have empirically explored the correlations between rural residents' flat social networks, trust in pyramidal channels, and disaster-risk perceptions. Taking Sichuan Province-a typical disaster-prone province in China-as an example and using data from 327 rural households in mountainous areas threatened by multiple disasters, this paper measured the level of participants' disaster-risk perception in the four dimensions of possibility, threat, self-efficacy, and response efficacy. Then, the ordinary least squares method was applied to probe the correlations between social networks, trust, and residents' disaster-risk perception. The results revealed four main findings. (1) Compared with scores relating to comprehensive disaster-risk perception, participants had lower perception scores relating to possibility and threat, and higher perception scores relating to self-efficacy and response efficacy. (2) The carrier characteristics of their social networks significantly affected rural residents' perceived levels of disaster risk, while the background characteristics did not. (3) Different dimensions of trust had distinct effects on rural residents' disaster-risk perceptions. (4) Compared with social network variables, trust was more closely related to the perceived level of disaster risks, which was especially reflected in the impact on self-efficacy, response efficacy, and comprehensive perception. The findings of this study deepen understanding of the relationship between social networks, trust, and disaster-risk perceptions of rural residents in mountainous areas threatened by multiple disasters, providing enlightenment for building resilient disaster-prevention systems in the community.

Livelihood resilience and strategies of rural residents of earthquake-threatened areas in Sichuan Province, China.

Natural disasters are increasing in frequency in China. Enhancing residents' livelihood resilience and adjusting their livelihood strategies have gradually become effective means of dealing with disaster risk. Therefore, it is of great significance to explore the livelihood strategies and livelihood resilience of rural residents in earthquake-stricken areas to help them cope with disaster risks. However, few studies have explored the correlation between residents' livelihood resilience and livelihood strategies from the perspective of residents' livelihood resilience. Based on a survey of 327 households in four districts and counties of Sichuan Province, China that were affected by the Wenchuan and Lushan earthquakes, we construct a framework for analyzing livelihood resilience and livelihood strategy selection. We comprehensively analyze the characteristics of livelihood resilience and livelihood strategy and explore their correlation using an ordinal multi-classification logistic regression model. The results show that: (1) Among 327 sample households, 90.21% were non-farming, 3.67% were part-time households and 6.12% were farming households. Residents' livelihood resilience is mainly based on their disaster prevention and mitigation capacity. (2) As far as the correlation between livelihood resilience and livelihood strategies is concerned, the stronger the buffer capacity in livelihood resilience, the more rural residents tend to engage in non-farming activities to obtain income. When other conditions remain unchanged, the logarithmic probability of choosing an agricultural livelihood strategy decreases by 21.814 for each unit of buffer capacity. From the perspective of residents' livelihood resilience, this study deepens our understanding of the relationship between livelihood resilience and livelihood strategy in earthquake-stricken areas. It also provides useful information for the formulation of policies to improve residents' resilience in disaster-threatened areas.

Investment risk and natural resource potential in "Belt & Road Initiative" countries: A multi-criteria decision-making approach.

Chinese enterprises that conduct overseas investment projects encounter diverse challenges that emerge from political, economic, social, and environmental risks in the host countries. To better assess the overseas investment risks faced by Chinese enterprises, this study introduced and assessed novel aspects and an indicator system. Moreover, the "Technique for Order Preference by Similarity to Ideal Solution" (TOPSIS) method based on entropy weight was performed to generate a comprehensive assessment of China's foreign investment risk and natural resource potential in 63 "Belt & Road Initiative" (BRI) countries. This study aims to encourage Chinese enterprises to devise suitable overseas investment decision-making strategies concerning natural resource potential in host countries. A Geographic Information System (GIS) map was also created to assess the potential risks and opportunities for Chinese enterprises when making investment decisions in host countries. The findings indicate that the majority of countries in Central and Eastern Europe and other BRI countries such as Singapore, Malaysia, Nepal, Bhutan, Russia, Armenia, and the United Arab Emirates were the most suitable choices for Chinese enterprises engaging in overseas investment. Based on these results, Chinese enterprises could manage and execute BRI projects more effectively to minimise potential risks and maximise their investment benefits.

Functional study of a novel c.630delG (p.Y211Tfs*85) mutation in NR5A1 gene in a Chinese boy with 46,XY disorders of sex development.

PURPOSE: This study aimed to present the clinical features and gene mutation characteristics of a child with 46,XY disorders of sex development (DSD) caused by a novel heterozygous mutation in the NR5A1 gene to determine the potential association between this heterozygous mutation and the pathogenesis of 46,XY DSD. METHODS: We present the case of a Chinese child with ambiguous genitalia at birth but a normal adrenal gland. Targeted next-generation sequencing, comprising 163 candidate genes involved in sexual differentiation and development, was performed, followed by the functional evaluation of the novel NR5A1 mutation. RESULT: The patient had a novel heterozygous mutation in the NR5A1 gene, c.630delG (p.Y211Tfs*85). Results revealed that overexpression of p.Y211Tfs*85 impaired steroidogenic factor-1 (SF-1) protein synthesis. Immunofluorescence analysis revealed that both SF-1 wild-type and p.Y211Tfs*85 mutation proteins were localized in the cell nucleus. Furthermore, dual-luciferase reporter assay results revealed that the p.Y211Tfs*85 mutation could effectively downregulate the transcriptional activation of anti-Müllerian hormone and steroidogenic acute regulatory protein genes (P < 0.01). Additionally, the p.Y211Tfs*85 mutation changed three-dimensional conformation of SF-1, and three conformations could be constructed with the mutated amino acid sequences. Therefore, the novel frameshift mutation could result in decreased protein expression of SF-1. CONCLUSION: We described a novel mutation in NR5A1 and showed that it might affect protein structure, thereby seriously compromising the role of SF-1 in regulating gonadal development. The novel p.Y211Tfs*85 mutation in the NR5A1 gene enriches the boy of information available regarding the mutation spectrum of this gene in the Chinese population.

Labor migration and farmland abandonment in rural China: Empirical results and policy implications.

Farmland abandonment is a universal socio-economic phenomenon in various countries in the world. However, there is a lack of the large-sample empirical research on rural households' farmland abandonment in China, and few studies have explored the quantitative influences of labor migration on rural households' farmland abandonment. This study uses the survey data of 8031 rural households from 27 provinces (cities) in China. It analyzes the spatial distribution characteristics of labor migration and farmland abandonment on the basis of provinces (cities). Moreover, it constructs the iv-probit models and the iv-tobit models to quantitatively explore the influences of off-farm employment and part-time employment on rural households' farmland abandonment. The results show that: Labor migration and farmland abandonment in various provinces (cities) of China present the trend of spatial area agglomeration. The regional differences of off-farm laborers are significant, whereas the regional differences of part-time laborers are relatively small; Labor migration would promote rural households' farmland abandonment. When other conditions remain unchanged, with every 10% increase in off-farm employment and part-time employment, the average probability of rural households' farmland abandonment increases by 4% and 5%, respectively, and the average farmland area that rural household abandons increases by 3% and 5%, respectively. This study can enhance the understanding of the relationship between labor migration and rural households' farmland abandonment in China, so as to provide reference for the rational allocation of labor resources and the formulation of the policies related to ensuring food security.