Shaanxi Province Of China Research Articles

Morphology and Phylogeny of Gnomoniopsis (Gnomoniaceae, Diaporthales) from Fagaceae Leaves in China.

Gnomoniopsis (Gnomoniaceae, Diaporthales) is a well-classified genus inhabiting leaves, branches and fruits of the hosts in three plant families, namely Fagaceae, Onagraceae and Rosaceae. In the present study, eighteen Gnomoniopsis isolates were obtained from diseased leaves of Fagaceae hosts collected from Fujian, Guangdong, Hainan, Henan, Jiangxi and Shaanxi provinces in China. Morphology from the cultures and phylogeny based on the 5.8S nuclear ribosomal DNA gene with the two flanking internally transcribed spacer (ITS) regions, the translation elongation factor 1-alpha (tef1) and the beta-tubulin (tub2) genes were employed to identify these isolates. As a result, seven species were revealed, viz. Gnomoniopsis castanopsidis, G. fagacearum, G. guangdongensis, G. hainanensis, G. rossmaniae and G. silvicola spp. nov, as well as a known species G. daii. In addition, G. daii was firstly reported on the host Quercus aliena.

Investigation and molecular identification of Eimeria sp. sampled from captive forest musk deer

Forest musk deer (Moschus berezovskii) is an endangered, protected species in China. Intestinal coccidiosis is a significant problem for captive forest musk deer. However, there are few reports on the prevalence and molecular characteristics of Eimeria sp. in forest musk deer. We sought to investigate the prevalence of Eimeria sp. in forest musk deer in the Sichuan and Shaanxi provinces in China. We also investigated the molecular characteristics of Eimeria sp. by analyzing the 18S rRNA gene. We collected a total of 328 fecal samples from forest musk deer on seven farms throughout the Sichuan and Shaanxi provinces. We extracted this parasite’s DNA and used this as a template for nested PCR amplification. The 18S rRNA gene fragment was associated with the plasmid vector, and these products were introduced into Escherichia coli (DH5α). The cultured bacterial solution was used as a PCR reaction template for identification purposes. We collected 328 fecal samples from forest musk deer in Lixian (n = 54), Maoxian (n = 52), Ma’erkang (n = 49), Dujiangyan (n = 55), Hanyuan (n = 41), Luding (n = 36) and Weinan (n = 41). One hundred ninety-eight (60.37%) fecal samples tested positive for Eimeria sp. . In our analysis of the 18S rRNA gene we found 34 types of Eimeria sp. with a similarity of 90.5–100%. We constructed a phylogenetic tree based on the parasite’s 18S rRNA gene sequence. Our findings indicated that the Eimeria sp. that parasitized the intestinal tract of forest musk deer was closely related to Eimeria alabamensis from Bos taurus and Eimeria ahsata from Ovis aries. To the best of our knowledge, ours was the first investigation and molecular identification of Eimeria sp. sampled from captive forest musk deer in China. Our results provide epidemiological data for the monitoring and prevention of Eimeria sp. in captive forest musk deer.

Synthesis and characterization of sustainable eco-friendly unburned bricks from slate tailings

The volume of tailings in the world has increased rapidly in recent years, which poses a substantial ecological threat. With the objective of reducing negative impacts on environment and reuse the abandoned slate tailings, the possibility of making eco-friendly unburned bricks by using slate tailings from Shaanxi Province of China was investigated. Raw materials included slate tailings, fly ash and cement, and bricks were produced through the process of mixing, molding, and curing. The optimal compressive strength of the product was found at the slate tailings: fly ash: cement = 5:2:3 (wt.%) with 7-day curing at room temperature and 1-day curing in oven, and the forming water content is 15 wt.%. Under these conditions, the compressive strength and water absorption rate were 26 MPa and 14.32% respectively. Other physical properties and durability conform to the Chinese GB/T4111-2013 standard for test methods for concrete blocks and bricks and the Chinese JC/T422-2007 standard for unfired bricks made of tailings. In addition, a variety of methods were combined to explore the formation mechanism. The phase composition, chemical structure and microstructure of the brick are analyzed by XRD, SEM and AFM. Finally, molecular dynamics (MD) was used to simulate main cementation component, the hydrated calcium silicate (C–S–H) gel, to advance the understanding of mechanical properties of brick at the nanoscale. The results show that the C–S–H gel formed in the curing process acted as the main adhesive component, and the slate tailings are mainly worked as aggregate skeleton to provide support strength for unburned bricks.

Stress Relief and Support for Stability of Deep Mining Roadway with Thick Top Coal in Hujiahe Coal Mine with the Risk of Rock Burst

Rock burst is a typical dynamic disaster in deep underground coal mining. Based on the support problems of the deep roadways in fully mechanized caving face 401111 of Hujiahe Coal Mine suffering from rock burst in Shaanxi Province of China, the failure law and influencing factors of the surrounding rock of the roadway are analyzed. The results show that the deformation of surrounding rock in the roadway shows the characteristics of elastic, plastic transformation, rheology, and expansion. At the same time, it has the typical characteristics of deep roadway, such as the fast deformation speed, long duration, asymmetric deformation, and large loose broken area of surrounding rock. Based on the principle of “strengthening support in shallow zones” and “deep pressure relief in deep zones” in the surrounding rock, the control scheme of surrounding rock in the return roadway of fully mechanized caving working face 401111 is proposed by taking the large diameter pressure relief and deep hole blasting as the main means of pressure relief. The practice shows that the surrounding rock of the return roadway is relatively stable after the implementation of the new scheme, which shows that the design of the new support scheme is reasonable and reliable. It is of great significance for the stability control of surrounding rock of the mining roadway suffering from rock burst.

Exploring the relationship between functional limitations of the older adults and the health-related quality of life of their spouse in Shaanxi Province, China

BackgroundWith trends towards longer life expectancy, lifetime with disability has also been prolonged. It is increasingly recognized that not only the person with disability but also those around them are affected. The relationship between functional limitation (FL) of the older adults and health-related quality of life (HRQoL) of their spouse is of interest. So too is the determination of the factors aside from FL that influence HRQoL.MethodsThe sample was derived from the 2013 National Health Service Survey conducted in Shaanxi Province in China. Married couples aged ≥ 60 years were selected (n = 3463). The European quality of life five dimensions (EQ-5D) and visual analogue scale were used to measure HRQoL.ResultsBoth wife and husband reported lower HRQoL if either the male or female partner had some or serious FLs (P < 0.001). Other factors associated with lower HRQoL of the spouse included age, lower educational level, presence of chronic disease, and lower household economic status. Family size was associated with wife's HRQoL only when the male had no FL and lived with another 1–2 persons, or when the male had some FLs and lived in a larger family (n ≥ 5). Residential status did not relate to the HRQoL of spouses regardless of FL status.ConclusionsOlder adults in Shaanxi province who have partners with FLs tend to report poorer EQ-5D, suggesting that couples amongst whom one has FL may be particularly vulnerable to lower HRQoL.

Identification of known leaf rust resistance genes in bread wheat cultivars from China

Leaf rust caused by Puccinia triticina Eriks. (Pt) is one of the most devastating fungal pathogens affecting wheat (Triticum aestivum L.) production worldwide. Deployment of resistant cultivars is the most environmentally friendly approach to control the disease. In this study, thirty-seven wheat lines from the Hubei and Shaanxi provinces in China were evaluated for seedling resistance in the greenhouse using eighteen Pt races. These lines were also tested for slow rusting resistance in the field in the 2014 to 2018 growing seasons. Eleven molecular markers closely associated with known Lr genes were used as part of the postulation process. Seven known Lr genes, 1, 13, 18, 14a, 26, 34 and 46 either singly or in combination were postulated in twenty-five cultivars. Lr1 and Lr26 were the most commonly identified genes detected in thirteen and ten cultivars, respectively. Lr13 and Lr46 were each found in four and five cultivars. Lr34 was present in three cultivars. Lr18 and Lr14a were identified in cultivar Xi’nong 538. Six cultivars displayed slow rusting resistance in the field tests. The resistant cultivars identified in the present study can be used as resistance parents in crosses aimed at pyramiding and the deployment of leaf rust resistance genes in China.

Spatiotemporal Assessment of Land Marketization and Its Driving Forces for Sustainable Urban–Rural Development in Shaanxi Province in China

In recent years, market-oriented allocation of land has been promoted to support rural revitalization and urban–rural integrated development. To follow the path of sustainable development, it is necessary to improve the efficiency of resource utilization and to rationally allocate and use resources on the premise of ensuring the sustainable use of resources. This study aims to measure the degree of land marketization in Shaanxi Province, China during the period 2008–2019 and analyze its driving forces. The methods used include Gray Relation Analysis and Hot Spot Analysis. The MK trend method was used to analyze the average area of land acquired through Bidding–Listing–Auction (B-L-A), protocol, and allocation methods. The results show that the land marketization level in Shaanxi declined from 2008 to 2014 and fluctuated upwards from 2014 to 2019. In addition, B-L-A transactions increased across the province. There was little spatial heterogeneity of land marketization, but southern Shaanxi had less land marketization than the other key areas. Urbanization, non-agricultural output, and foreign direct investment were found to be the main driving factors of land marketization, while the influence of fixed asset investment and per capita disposable income declined each year. Based on these findings, we suggest that there is a need for land management reforms and urbanization efforts to encourage land marketization in southern Shaanxi. Further, we suggest that northern Shaanxi would benefit from optimizing the land use structure and focusing on the energy land market. This study also provides theoretical support for realizing the reform of the marketization of national land elements, the healthy operation of urban land marketization, and sustainable urban and rural development.

A new species of the genus Falsomesosella Pic, 1925 (Coleoptera: Cerambycidae) from Shaanxi province of China

A new species of the genus Falsomesosella Pic, 1925 (Coleoptera: Cerambycidae) from Shaanxi province of China

The Associated Factors of Prolonged Screen Time and Using Electronic Devices before Sleep among Elderly People in Shaanxi Province of China: A Cross-Sectional Study.

This study aimed to investigate prolonged screen time and using electronic devices before sleep and their associated factors in elderly people in Shaanxi province of China. We conducted a cross-sectional study among 2647 elderly participants aged 60–88 years. Data were collected through questionnaires. Demographic characteristics, screen time, using electronic devices before sleep, health status, lifestyles, sleep quality, and other associated factors were investigated. Logistic regression analysis was used to analyze the relationship between the associated factors of screen time and using electronic devices before sleep. The crude odds ratio (cOR) and adjusted odds ratio (aOR) and their 95% confidence intervals (CI) were calculated. A total of 1784 subjects completed the questionnaire. There were 6.89% participants with prolonged screen time and 13.45% using electronic devices before sleep frequently. Prolonged screen time was associated with personal monthly income (aOR = 1.205, p = 0.001), number of household residents (aOR = 0.860, p = 0.010), rural residents (aOR = 0.617, p = 0.038), and regular drinkers (aOR = 2.889, p < 0.001). Using electronic devices before sleep was associated with being female (aOR = 0.657, p = 0.007), family monthly income (aOR = 0.866, p = 0.002), being an occasional drinker (aOR = 1.891, p = 0.005), and self-reported sleep quality (aOR = 1.593, p = 0.007). In conclusion, several factors related to screen time or using electronic devices before sleep were identified. Only being a drinker was a common associated factor for both screen time and using electronic devices before sleep.

Comparing the pelvis of Tibetan and Chinese Han women in rural areas of China: two population-based studies using coarsened exact matching

This study aims to investigate the difference of pelvic size and shape between Tibetan and Chinese Han women. Data on pelvic dimension measures including interspinous diameter (IS), intercrestal diameter (IC), external conjugate (EC) and transverse outlet (TO) were acquired from two population-based studies amongst Tibetan women in Lhasa, and Chinese Han women in Shaanxi province in China. After coarsened exact matching, there was no statistical difference between any characteristics amongst Tibetan and Chinese Han women (p>.05). The generalised estimating equation models showed Tibetan women had significantly lower IS and IC means than Chinese Han women (IS: 24.39 cm vs. 24.77 cm, p<.001; IC: 26.35 cm vs. 26.93 cm, p<.001) but statistically higher in TO mean (9.12 cm vs. 9.03 cm, p<.001). This study showed Tibetan women have smaller pelvis compared to Chinese Han women. This should offer a useful literature on the comparison of pelvis between Tibetan and Chinese Han women although the difference is small. Impact Statement What is already known on this subject? Previous studies in China indicated different populations have different dimensions of pelvis, with the pelvis of Uighur women being bigger than Chinese Han women, and that of Zhuang and Tu women being smaller than Chinese Han women. Little research reports the specific size of Tibetan women’s pelvis. Living at high altitude, the Tibetan population have differentiated demographics and show local adaptions, such as unelevated haemoglobin, and significant catch-up growth for infants compared with Chinese Han infants. Therefore, there is a strong rationale for better understanding pelvic characteristics amongst this population. What the results of this study add? This study showed Tibetan women have smaller pelvises compared to Chinese Han women. Tibetan women have a smaller interspinous diameter and intercrestal diameter than Chinese Han women, which leads to relatively narrow hip. What the implications are of these findings for clinical practice and/or further research? This study provides useful comparative information on pelvic features between Tibetan and Chinese Han women although the findings of differences were small. In addition, during the formulation of women’s health policy, the results of this study can provide data to support the selection of appropriate indicators of obstetrics and gynaecology for different populations of pregnant women during antenatal care and delivery.

Can the human development level in middle-income regions meet the challenges of natural capital change from the perspective of decoupling? Evidence from Shaanxi Province.

Human activities in middle-income regions (MIRs) accelerate the appropriation of natural capital (NC) through production and living activities. The environmental changes caused by these activities in turn have an impact on human development and challenge the human adaptability of MIRs. Therefore, it is very important to realize the decoupling of NC and human development. This study takes China's Shaanxi Province as a case and establishes a research framework that decouples the human development index (HDI) from the perspective of NC stock and flow. Shaanxi is evaluated based on an analysis of the changing HDI and measuring changes in NC indicators from 2005 to 2018. The state of decoupling between the HDI and NC utilization levels is also discussed. The results show that the average annual growth of the HDI and per capita ecological footprint is 1.54% and 3.22%, respectively. The rate of consumption of the NC stock is greater than the rate of NC flow consumption. The HDI and the three-dimensional ecological footprint have not achieved real decoupling, and the changes in the two are the same as those in the left half of the inverted U-shaped environmental Kuznets curve. However, the inflection point has not been reached. This shows that the NC and HDI in Shaanxi have not achieved decoupling, and rapid NC changes hinder the ability to improve human well-being. This discovery helps MIRs focus on the role of restoration ecosystems in supporting regional human development and respond to the challenge of insufficient human adaptability due to excessive consumption of NC.

Preliminary prediction of the control reproduction number of COVID-19 in Shaanxi Province, China.

ObjectivesFirstly, according to the characteristics of COVID-19 epidemic and the control measures of the government of Shaanxi Province, a general population epidemic model is established. Then, the control reproduction number of general population epidemic model is obtained. Based on the epidemic model of general population, the epidemic model of general population and college population is further established, and the control reproduction number is also obtained.MethodsFor the established epidemic model, firstly, the expression of the control reproduction number is obtained by using the next generation matrix. Secondly, the real-time reported data of COVID-19 in Shaanxi Province is used to fit the epidemic model, and the parameters in the model are estimated by least square method and MCMC. Thirdly, the Latin hypercube sampling method and partial rank correlation coefficient (PRCC) are adopted to analyze the sensitivity of the model.ConclusionsThe control reproduction number remained at 3 from January 23 to January 31, then gradually decreased from 3 to slightly greater than 0.2 by using the real-time reports on the number of COVID-19 infected cases from Health Committee of Shaanxi Province in China. In order to further control the spread of the epidemic, the following measures can be taken: (i) reducing infection by wearing masks, paying attention to personal hygiene and limiting travel; (ii) improving isolation of suspected patients and treatment of symptomatic individuals. In particular, the epidemic model of the college population and the general population is established, and the control reproduction number is given, which will provide theoretical basis for the prevention and control of the epidemic in the colleges.

Impact of water deficit on the development and senescence of tomato roots grown under various soil textures of Shaanxi, China

PurposeWater scarcity is expected to extend to more regions of the world and represents an alarming threat to food security worldwide. Under such circumstances, water holding capacity is an important agronomic trait, which is primarily controlled by soil texture.MethodsOur work examined three different soil textures from three cities of Shaanxi Province in China, i.e., silt-sandy loam from Yulin (north of Shaanxi), loam—clay loam from Yangling (middle and western part of Shaanxi), and clay loam-clay from Hanzhong soil (south of Shaanxi), at two moisture levels, i.e., field capacity of 70–75% (well-watered) and 50–55% (water deficit).ResultsThe differences in soil particle sizes altered the soil physiochemical properties and soil enzymatic activities. Soil urease and ß-glucosidase activities were significantly higher in the Yangling soil under the well-watered treatment, while the differences were nonsignificant under the water deficit conditions. The leaf photosynthesis rate and total chlorophyll content were significantly higher in Hanzhong soil after 15 days of treatment; however, the overall highest plant length, root cortex diameter, and xylem element abundance were significantly higher in Yangling soil under the water deficit conditions. Furthermore, comparable differences were observed in antioxidant defence enzymes and endogenous hormones after every 15 days of treatments. The auxin, gibberellic acid and cytokinin concentrations in leaves and roots were comparably high in Yangling soil, while the abscisic acid concentrations were higher in Hanzhong soil under the water deficit conditions.ConclusionsOur findings concluded that soil compaction has a significant role not only in root morphology, growth, and development but also in the soil physicochemical properties and nutrient cycle, which are useful for the growth and development of tomato plants.

LC-Q-Orbitrap HRMS-based proteomics reveals potential nutritional function of goat whey fraction

• Large variations in protein composition were observed between goat and bovine milk. • Abundance of GSN, SERPINA1, C3, and APOA1 were high in goat mature milk. • Functional analysis of the identified protein revealed potential biological function. • These results expand the direction for dairy-based functional food exploitation. Guanzhong dairy goat milk is the product of national geographical indication exclusively in Shaanxi province of China. A total of 433 whey proteins were identified and quantified in colostrum and mature milk, which were obtained from Guanzhong dairy goat and Chinese Holstein. Twenty-seven highly expressed proteins in GM were related to immune response, and 23 were metabolic processes. Thirty-four highly expressed proteins in GC milk were mainly related to the immune response, negative regulation of endopeptidase activity and ossification, indicating that goat milk was very important for the development of immune system and bone growth and ossification in newborns. Bioinformatics analysis showed that the differentially expressed proteins in the four whey groups were mapped in 15 pathways, in which the complement and coagulation cascade and carbon metabolism were the most important. Cross-species comparison of whey protein helps to extend understanding of variation in the nutritional value of different milk sources.

Optical solitons supported by finite waveguide lattices with diffusive nonlocal nonlinearity* *Project supported by the National Natural Science Foundation of China (Grant No. 11704339), the Applied Basic Research Program of Shanxi Province, China (Grant No. 201901D211466), the Natural Science Basic Research Plan in Shaanxi Province of China (Grant No. 2019JM-307), and the Scientific and Technological Innovation Programs of Higher Education

We investigate the properties of fundamental, multi-peak, and multi-peaked twisted solitons in three types of finitewaveguide lattices imprinted in photorefractive media with asymmetrical diffusion nonlinearity. Two opposite soliton self-bending signals are considered for different families of solitons. Power thresholdless fundamental and multi-peaked solitons are stable in the low power region. The existence domain of two-peaked twisted solitons can be changed by the soliton self-bending signals. When solitons tend to self-bend toward the waveguide lattice, stable two-peaked twisted solitons can be found in a larger region in the middle of their existence region. Three-peaked twisted solitons are stable in the lower (upper) cutoff region for a shallow (deep) lattice depth. Our results provide an effective guidance for revealing the soliton characteristics supported by a finite waveguide lattice with diffusive nonlocal nonlinearity.

Effects of Vision Health Education and Free Eyeglasses on Knowledge of Vision and Usage of Spectacles Among Primary School Students: Evidence from Gansu and Shaanxi Provinces in China

BackgroundIn rural China, children’s vision problems are very common, with many who would benefit from refractive correction not getting the care they need. This study examines whether a health information campaign that involves vision health education and a free trial of health product with free eyeglasses is effective at raising students’ awareness of myopia and promoting students’ eyeglasses usage.MethodsWe conducted an in-the-field randomized controlled experiment of a program providing vision health education and subsidized free eyeglasses to myopic children from 168 primary schools in rural Northwestern China in 2012.ResultsA total of 2189 students, mean age 10.5 years (49.3% male), participated in the baseline survey. At the baseline, the average correct response rate for visual knowledge among the sample students was 30.1%, and only 15% who needed eyeglasses used them. Seven months after intervention, the average correct response rate for vision knowledge were 48.5% and 48.3% in the education group and the education plus free eyeglasses group respectively, significantly higher than that of the control group. The rate of eyeglasses usage was 36% and 43% in the free eyeglasses group and the education plus free eyeglasses group respectively, significantly higher than that of the control group. The rate of eyeglasses compliance in the free eyeglasses group and the education plus free eyeglasses group was 19% and 26%, which also were significantly higher than the control group.ConclusionThe information campaign combined with subsidized eyeglasses had a better effect both on vision knowledge and eyeglasses usage. The information campaign improved knowledge by providing the right information, and free eyeglasses changed the perceived utility and experience by the students using the product and getting benefits. Information and the free eyeglasses (subsidized) are complements.

Molecular Characteristics and Drug Resistance of Mycobacterium tuberculosis Isolate Circulating in Shaanxi Province, Northwestern China.

Objective: Shaanxi is the most highly populated province with high burdens of tuberculosis in northwestern China. The aim of this study was to investigate the molecular characteristics and drug resistance of Mycobacterium tuberculosis isolates from Shaanxi province of China in 2018. Methods: Phenotypic drug susceptibility testing and spoligotyping methods were performed on 518 M. tuberculosis isolates; drug-resistant isolates were sequenced in 11 drug loci, including katG, inhA, oxyR-ahpC, rpoB, embB, rpsL, rrs1 (nucleotides 388-1084), gyrA, gyrB, rrs2 (nucleotides 1158-1674), and eis. Results: The prevalences of isoniazid, rifampicin, ethambutol, streptomycin, ofloxacin, and kanamycin resistance were 22.0%, 19.3%, 7.9%, 23.8%, 10.4%, and 3.3%, respectively. The Beijing family (82.8%) was the predominant genotype, followed by the T (9.3%), H (0.6%), CAS (0.4%), LAM (0.4%), and U (0.4%) families. The percentage of Beijing genotype in a central area (88.1%) was higher than in the south (77.3%) and the north area (80.1%) (p < 0.05), while the sex, age, and treatment history between Beijing and non-Beijing family were not statistically different. Mutation analysis found that the most prevalent mutations were katG315, rpoB531, embB306, rpsL43, gyrA94, and rrs1401; the Beijing family exhibited a high rate of isoniazid-resistant isolates carrying katG315 mutations (p < 0.05). Furthermore, compared with the phenotypic data, the sensitivities of isoniazid, rifampicin, ethambutol, streptomycin, ofloxacin, and kanamycin resistance by sequencing base on 11 loci were 85.1%, 94.0%, 53.7%, 74.8%, 77.8%, and 64.7%, respectively. Conclusions: Shaanxi has a serious epidemic of drug-resistant tuberculosis, Beijing family is the predominant genotype, and the distribution showed geographic diversity. The prevalence of Beijing genotypes has a tendency to promote the transmission of high-level isoniazid-resistant M. tuberculosis. Besides, the hot spot regions localized in the embB, rrs2, and eis gene appear not to serve as excellent biomarkers for predicting ethambutol and kanamycin resistance in Shaanxi.

Fine-grained uncertainty relation for open quantum system* *Project supported by the National Natural Science Foundation of China (Grant No. 12075178) and the Natural Science Basic Research Plan in Shaanxi Province of China (Grant No. 2018JM1049).

The fine-grained uncertainty relation (FUR) is investigated for accelerating open quantum system, which manifests the celebrated Unruh effect, a crucial piece of the jigsaw for combining relativity and quantum physics. For a single detector, we show that the inevitable Unruh decoherence can induce a smaller FUR uncertainty bound, which indicates an additional measurement uncertainty may exist. For an open system combined with two detectors, via a nonlocal retrieval game, the related FUR uncertainty bound is determined by the non-classical correlation of the system. By estimating the maximal violation of Bell inequality for an accelerating system, we show that the FUR uncertainty bound can be protected from Unruh decoherence, due to quantum correlation generated through Markovian dynamics.

The adoption and impact of E-commerce in rural China: Application of an endogenous switching regression model

Rural e-commerce is embraced as an opportunity for economic advancement for farmers in developing countries. However, little empirical evidence has been presented about the factors that affect farmers' decisions to adopt e-commerce, and how much farmers benefit from as well as cost on the adoption. This study addresses this research gap by analyzing rural household data collected in the Shandong, Henan and Shaanxi provinces of China in 2019, utilizing an endogenous switching regression (ESR) model to address the self-selection bias issue. The empirical results show that education level, smartphone use, off-farm employment and social capital significantly impact farmers' decisions to adopt e-commerce. E-commerce adoption drives a significant increase in selling price; yet simultaneously causes a tremendous increase in marketing costs for farmers. The operation of e-commerce requires farmers to pay considerable costs that were formerly undertaken by intermediaries in conventional exchange transactions. Still, farmers are seen to benefit from adopting e-commerce, as the gross return shows an increase. The PSM approach is employed for the robustness check, which obtains consistent results with the ESR model. The results of the heterogeneous analysis show that the rural households that are located closer to the local township benefit more from the adoption of e-commerce. Overall, this study presents a better understanding of the actual impacts of adopting e-commerce for farmers in rural China, which provides valuable insights for other developing countries or regions that also engage in rural e-commerce to promote the development of rural economy.

Analysis of dynamic contact network of patients with COVID-19 in Shaanxi Province of China

The spread of COVID-19 is closely related to the structure of human social networks. Based on 237 cases, by using epidemiological retrospective statistics, data visualization, and social network analysis methods, this paper summarized characteristics of patients with COVID-19 in Shaanxi, China, and analyzed these patients’ dynamic contact network structure. The study found that there are many clustered infections through strong ties, about one-third of cases are caused by relatives' infection. In early stages of the epidemic, imported cases were the most, and in the later stages, local infection cases were the most. The infected people were mostly middle-aged men. Symptoms of imported cases occurred on average of 3 days after they arrived, and medical measures were taken 5 days later on average. All cases showed symptoms in less than 2 days on average and were then taken to medical treatment. The contact network can be divided into multiple disconnected components. The largest component has 12 patients. The average degree centrality in the network is 0.987, average betweenness degree is 0, average closeness degree is 0.452, and average PageRank index is 0.0042. The number of contacts of patients is unevenly distributed in the network.