Ningxia Research Articles

Water and Nitrogen Regulation Effects and System Optimization for Potato (Solanum tuberosum L.) under Film Drip Irrigation in the Dry Zone of Ningxia China

Potatoes require water and fertilizer management systems to optimize economic outcomes and fertilizer use, especially in arid areas such as Ningxia, China. In this study, three irrigation quotas (1200 (W1), 1650 (W2), and 2100 (W3) m3/hm2) and three nitrogen application treatments (110 (N1), 190 (N2), and 270 (N3) kg/hm2) were evaluated. Potato growth, final yield, and quality indices were assessed in relation to fertility periods, irrigation utilization efficiency, nitrogen and fertilizer bias productivity, and economic efficiency, using the TOPSIS model. Stem thickness and plant height varied significantly with irrigation and nitrogen treatments; total yield and vitamin C, reducing sugar, and starch contents were the highest under the W3N1, W3N1, W1N2, and W2N3 treatments, increasing by 54.56, 17.00, 69.00, and 45.00%, respectively, compared with those in the control. The regression relationships between water and nitrogen regulation and yield, irrigation water use efficiency, nitrogen fertilizer bias productivity, and economic efficiency agreed with the binary quadratic regression model, and the coefficients of determination (R2) were >0.85. W3N1 was optimal for model yield, nitrogen fertilizer bias productivity, and economic efficiency, and W1N3 was optimal for irrigation water use efficiency. Our findings will help optimize potato management in central Ningxia.

Diversity analysis of vineyards soil bacterial community in different planting years at eastern foot of Helan Mountain, Ningxia

In order to analyze the problem of barriers to continuous vineyard planting, we studied the diversity of soil bacterial communities in vineyards in the eastern foothills of the Helan Mountains in the Ningxia Hui Autonomous Region in different planting years. Rhizosphere and non-rhizosphere soils (0–20 cm) of vineyards planted for 3, 8 and 20 years were collected to determine the composition and community structure of soil bacterial species using high-throughput sequencing technology, and to analyze their correlation with environmental factors. The results showed that: The total number of OUTs was 2523 in 18 soil samples, and they were identified belonging to 549 genera, 233 families, 119 orders, 54 classes and 42 phyla. The dominant phyla were Proteobacteria, Actinobacteria, Acidobacteria, Bacteroidetes, Gemmatimonadetes, Chloroflexi and Firmicutes (relative abundance>1%). Arthrobacter, Nocardioides and Sphingomonas were the top three genera in relative abundance. The relative abundance of beneficial genera such as Niastella, Mesorhizobium, Solirubrobacter and Ensifer decreased with increasing vine growth time, resulting in a decrease in nitrogen fixation and heavy metal resistance in the vineyard. Pathogenic bacteria did not increase significantly in vineyards. The structure of the bacterial community in the soil of the vineyard surface changed significantly after 8 years planted. The correlation analysis of bacteria in the soil samples with environmental factors of the soil showed that soil pH, electric conductivity, and total potassium significantly affected changes in the structure of the bacterial community. The available potassium, total nitrogen, electric conductivity, available phosphorus and total phosphorus had significant effects on the changes in the number of the top ten bacterial species in terms of relative abundance at the genus level. It was found that changes in the bacterial community in vineyard soils as the vines age mainly diminish the vine's nutrient acquisition capacity, thus inhibiting vine growth and development. Such changes had little effect on vine disease. We believe that the frequency of fertilization should be increased and the proportion of nitrogen fertilizer should be increased during the grape growing period. The results of this study can provide a data reference and theoretical basis for improving the quality of the vineyard soil, evaluating the microecological effects of the soil, and promoting the sustainable development of the ecological environment of the vineyard soil.

Hepatitis C virus genotype diversity in Ningxia Hui autonomous region, Northwestern China

Hepatitis C virus (HCV) genotypes vary greatly in different regions. The aim of this study is to investigate the distribution of HCV genotypes in HCV infected patients, in Ningxia Hui Autonomous Region. Nucleic acid extraction and amplification were performed with test kits on 153 HCV infected patients serum samples. The HCV viral load was measured using reverse transcriptase PCR (RT-PCR) and HCV genotypes were determined. Among the 153 HCV-infected patients, 56 had genotype (GT)1b (36.60%), 45 had GT2a (29.40%), 23 had GT3a (15.00%), 14 had GT3b (9.20%),13 had GT6a (8.50%), 1 had GT1g (0.70%), 1 had GT6xa (0.70%). In GT1b, 21.40% were female and 78.60% were male; in GT2a, 42.20% were female and 57.80% were male;Males were most prevalent in genotypes 1b(39.30%), while female were most prevalent in genotype 2a(46.30%). Rare GT1g and GT6xa were also detected in males. The 41-50 year age group had the highest HCV prevalence of 32.00%. HCV GT1b is the predominant HCV genotype in Ningxia Hui Autonomous Region.

Very short-term probabilistic prediction of PV based on multi-period error distribution

• Empirical mode decomposition based on long short-term memory and backpropagation neural network (EEMD-LSTM-BP) is proposed. • EEMD is utilized to study the characteristic of wave behaviors in different frequency domains. • LSTM and BP are used to determine intrinsic mode functions (IMFs) and remaining components. • Based on the dataset of PV stations in Ningxia Province, the case studies verify the method's feasibility. As the penetration rate of photovoltaic (PV) in the grid increases, enormous challenges have been brought into power grid dispatcher's operation. Efficient and accurate PV power prediction is the key to solve this problem. Considering multi-period error distribution (MPED), a novel probabilistic prediction approach via ensemble empirical mode decomposition based on long short-term memory and backpropagation neural network (EEMD-LSTM-BP) is proposed. EEMD is utilized to study the characteristic of wave behaviors in different frequency domains. LSTM and BP are used to determine intrinsic mode functions (IMFs) and remaining components, respectively. Afterward, based on the prediction errors, PV power output fluctuation in different periods is analysed. The segment points are determined by Nadaraya-Watson (N-W) kernel regression. The bounds of prediction intervals (PIs) are quantified based on the error probability distribution. Based on the dataset of PV stations in Ningxia Province, the case studies verify the method's feasibility.

Research on Public Cultural Services in Minority Areas (Ningxia Hui Autonomous Region)

Research on Public Cultural Services in Minority Areas (Ningxia Hui Autonomous Region)

An Adaptive Predictive Control Algorithm for Comprehensive Dendritic Canal Systems

Automatic canal control is essential to improve water utilization efficiency in irrigation districts. Water level error in the model used by the control algorithm significantly impacts performance. The integrator delay model, which has a linear structure, is widely used in multi-input/multioutput control algorithms, including linear-quadratic control and model predictive control. However, the integrator delay model is suboptimal for large irrigation districts; the canals are long, the flows are large, there are many scattered offtakes, and the operating conditions vary. We developed an adaptive predictive control mode for the Qinhan Canal in Ningxia Province, China. We used a segment integrator delay model for this large irrigation district and employed a differential evolution algorithm for online system identification; this minimizes error. We analyzed and controlled for various uncertainties (i.e., flow observation noise, geometric and hydraulic parameter errors, and accidental interference with the automatic control system). Simulations indicated that the water level fitting errors were significantly reduced compared with the original model, and water level regulation was significantly improved, especially in terms of the maximum absolute error. Adaptive predictive control was better than linear-quadratic control and model predictive control approach for water level. Adaptive predictive control coped well with several uncertainties. The main factors affecting water level control were the flow observation and gate opening control accuracy, and the extent of real-time data coverage. These features require careful attention when automating and modernizing irrigation districts.

Whether the Distribution of Medical Resources among Provinces is Balanced

Objective: To explore the distribution and difference of medical resources among 31 provinces (municipalities) in China. Methods and process: According to the health resource indicators of 31 provinces in China Health Statistical Yearbook and China Statistical Yearbook, we described and analyzed the total amount of medical and health resources, per capita medical and health resources and high-quality medical resources. By using cluster analysis and RSR (Rank-sum ratio) comprehensive evaluation method, the difference of medical resources among 31 provinces in China in 2020 was calculated, and the medical resources of each province were classified, compared and analyzed to describe the difference. Results and conclusions: (1) From the perspective of total medical resources, the total medical resources in the western region are far less than those in the eastern region, showing a situation of "more in the east and less in the west". Provinces with large populations have large medical resources. Developed cities such as Beijing and Shanghai have great advantages in medical and health financial resources, while provinces in remote areas are extremely backward in human, material and financial resources.(2)Unbalanced distribution of high-quality medical resources: tertiary hospitals are mainly concentrated in eastern and central China. The number and scale of tertiary hospitals in western China are obviously backward. China's top 100 hospitals are mainly distributed in the first tier and economically developed cities. Beijing, Shanghai and Guangzhou accounted for half of the top 100 hospitals. Nearly half of China's provinces have no hospitals on the "Top 100" list. (3) Per capita medical resources vary greatly. The per capita level of medical resources in the three northeastern provinces (Inner Mongolia, Qinghai, Sichuan, Beijing and Shanghai) is relatively high. The per capita level of medical resources in Anhui, Jiangxi, Guangdong, Ningxia and other provinces is low.

Multiwater Index Synergistic Monitoring of Typical Wetland Water Bodies in the Arid Regions of West-Central Ningxia over 30 Years

The Shapotou National Nature Reserve in the Ningxia Hui Autonomous Region is a typical arid region in China. There is an exceptionally serious problem of surface water resource conservation, and dynamic monitoring of surface water with the help of water indices can help to elucidate its change patterns and impact mechanisms. Here, we analysed the characteristics of interannual variation in surface water area in the study area from 1992–2021. The correlation coefficients of the surface water area in the previous year and the contemporaneous water bodies of the Yellow River with the total surface water area (TSWA) were calculated. The results show the following: ① In terms of the classification accuracy of the two methods, water indices and support vector machine classification, water indices are more suitable for water body extraction in the study area. In particular, the three water indices, NDWI, MNDWI and AWEIsh, were more effective, with average overall accuracies of 90.38%, 90.33% and 90.36% over the 30-year period, respectively. ② From the TSWA extraction results from the last 30 years, the TSWA showed an increasing trend with an increase of 368.28 hm2. Among the areas, Tenggeli Lake contributed the most to the increase in TSWA. ③ The highest correlation between the TSWA and the previous year’s TSWA was 0.89, indicating that the better way to protect the water body is to maintain water surface stability year-round. The surface water area of the Yellow River and TSWA also showed a strong correlation, indicating that the rational use of Yellow River water is also an important direction for the future conservation of water resources in the study area.

Virulence, Antibiotic Resistance, and Phylogenetic Relationships of Aeromonas spp. Carried by Migratory Birds in China.

This study aimed to evaluate antimicrobial resistance, virulence, and the genetic diversity of Aeromonas isolated from migratory birds from Guangxi Province, Guangdong Province, Ningxia Hui Autonomous Region, Jiangxi Province, and Inner Mongolia in China. A total of 810 samples were collected, including fresh feces, cloacal swabs, and throat swabs. The collected samples were processed and subjected to bacteriological examination. The resistance to 21 antibiotics was evaluated. A phylogenetic tree was constructed using concatenated gltA-groL-gyrB-metG-PPSA-recA sequences. Eight putative virulence factors were identified by PCR and sequencing, and a biofilm formation assay was performed using a modified microtiter plate method. In total, 176 Aeromonas isolates were isolated including A. sobria, A. hydrophila, A. veronii, and A. caviae. All isolates showed variable resistance against all 16 tested antibiotic discs, and only one antibiotic had no reference standard. Six kinds of virulence gene markers were discovered, and the detection rates were 46.0% (hlyA), 76.1% (aerA), 52.3% (alt), 4.5% (ast), 54.0% (fla), and 64.2% (lip). These strains were able to form biofilms with distinct magnitudes; 102 were weakly adherent, 14 were moderately adherent, 60 were non-adherent, and none were strongly adherent. Our results suggest that migratory birds carry highly virulent and multidrug-resistant Aeromonas and spread them around the world through migration, which is a potential threat to public health.

A comparative study of virus nucleic acid re-positive and non-re-positive patients infected with SARS-CoV-2 Delta variant strain in the Ningxia Hui Autonomous Region.

This study aimed to provide a basis for epidemic prevention and control measures as well as the management of re-positive personnel by analyzing and summarizing the characteristics of re-positive patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta variant infections discharged from a hospital in the Ningxia Hui Autonomous Region in 2021. This case-control study included a total of 45 patients with Delta variant infections diagnosed in the Fourth People's Hospital of the Ningxia Hui Autonomous Region between October 17 and November 28, 2021. Based on the nucleic acid test results post-discharge, the patients were dichotomized into re-positive and non-re-positive groups. Based on the time of the first re-positive test, the re-positive group was further divided into <7 and ≥7 days groups to compare their clinical characteristics and explore the possible influencing factors of this re-positivity. Of the 45 total patients, 16 were re-positive (re-positivity rate: 35.6%), including four patients who were re-positive after 2 weeks (re-positivity rate: 8.8%). The median time of the first re-positive after discharge was 7 days (IQR: 14-3). The re-positive group was younger than the non-re-positive group (35 vs. 53, P < 0.05), had a higher proportion of patients who were not receiving antiviral therapy (56.2 vs. 17.2%, P < 0.05). The median CT value of nucleic acid in the re-positive group was considerably greater than that at admission (36.7 vs. 22.6 P < 0.05). The findings demonstrated that neutralizing antibody treatment significantly raised the average IgG antibody level in patients, particularly in those who had not received COVID-19 vaccine (P < 0.05). The median lowest nucleic acid CT value of the ≥7 days group during the re-positive period and the immunoglobulin G (IgG) antibody level at discharge were lower than those in the <7 days group (P < 0.05). When compared to the non-positive group, patients in the ≥7 days group had a higher median virus nucleic acid CT value (27.1 vs. 19.2, P < 0.05) and absolute number of lymphocytes at admission (1,360 vs. 952, P < 0.05), and a lower IgG antibody level at discharge (P < 0.05). In conclusion, this study found that: (1) The re-positivity rate of SARS-CoV-2 Delta variant infection in this group was 35.6%, while the re-positivity rate was the same as that of the original strain 2 weeks after discharge (8.0%). (2) Young people, patients who did not use antiviral therapy or had low IgG antibody levels at discharge were more likely to have re-positive. And the CT value of nucleic acid at the time of initial infection was higher in re-positive group. We speculated that the higher the CT value of nucleic acid at the time of initial infection, the longer the intermittent shedding time of the virus. (3) Re-positive patients were asymptomatic. The median CT value of nucleic acid was > 35 at the re-positive time, and the close contacts were not detected as positive. The overall transmission risk of re-positive patients is low.

Clinical Characteristics, Antimicrobial Resistance, and Outcomes of Patients with Invasive Pneumococcal Disease in Ningxia Hui Autonomous Region, China, 2013-2021.

This study aimed to analyze the clinical features, antibiotic susceptibility profiles, and outcomes of patients with invasive pneumococcal disease (IPD) at a hospital in Ningxia Hui Autonomous Region, to provide the basis for improving the clinical treatment effect. Patients with IPD were retrospectively collected from 2013 to 2021. Clinical manifestations, laboratory tests, antimicrobial susceptibility, antibiotic treatment, and outcomes of the disease were analyzed. In this study, we identified 127 IPD cases, of whom 49 (38.6%) had meningitis and 78 (61.4%) had bacteremia. The median ages of pediatric cases and adult cases were 2 years (IQR: 0-5) and 52.5 years (IQR: 35-62), respectively. There were 27 and 45 males in the pediatric and adult groups, and no significant gender difference in the different age groups (p = 0.584) was found. Of 75 cases with underlying diseases, pneumonia (11%), malignancy (11%), hypertension (9.4%), and hepatic cirrhosis (7.9%) were the most common. The incidence of underlying diseases was even higher in the adult group (67.1%) than in the pediatric group (47.1%) (p = 0.028). The frequency of fever, cough, and seizures was significantly higher in the pediatric group than in the adult group, with p-values of 0.004, 0.004, and 0.001, respectively. The percentage of neutrophils in the blood was significantly higher in the adult cases than in the pediatric cases (p < 0.001). Furthermore, there was a significantly higher WBC count (p < 0.001), percentage of neutrophils (p = 0.012), and protein level (p = 0.019) in the CSF samples in the adult patients compared to pediatric patients. The susceptibility rates of S. pneumoniae isolates to vancomycin, linezolid, and levofloxacin were 100%. The susceptibility rates of penicillin were 98.7% and 34.1% in bacteremia and meningitis patients, respectively. Most isolates were resistant to erythromycin, clindamycin, tetracycline, and azithromycin. The most common antibiotic treatment was β-lactams. Seven (5.5%) patients died during hospitalization, and 38 (29.9%) patients' health deteriorated. These results may provide a reference basis for the diagnosis and empiric treatment of IPD in the region.

The Dominant Livelihood Types of Farm Households and Their Determinants in Key Ecological Function Areas

The dominant livelihood types of farm households have become increasingly differentiated in recent years, which has attracted the attention of researchers. Identifying the characteristics and driving factors of household livelihood differentiation is of great significance for revealing man-land relationship and policy making. Based on the interview data of farm households in typical villages in key ecological function areas of Ningxia Hui Autonomous Region in China, we analyzed the pattern of the dominant diversified livelihood types and the livelihood characteristics among different farm households. Then we assessed the driving forces of livelihood diversification by optimal scaling regression. The results indicated that: (1) In the study area, the dominant livelihood types show two trends of agriculturally dominant livelihood (accounting for 53.07%) and non-agriculturally dominant livelihood (accounting for 46.93%). Moreover, farm households in the agro-pastoral areas are mainly agriculturally dominated (accounting for 75.68%), while farm households in the mountainous areas are mainly non-agriculturally dominated (accounting for 66.93%). (2) The labor allocation and income source of different types of farm households are consistent with their dominant livelihood types. The farm households with agriculturally dominant livelihoods have more natural resources than those with non-agriculturally dominant livelihoods. In terms of housing conditions, farm households with agriculturally dominant livelihoods are inferior to those with non-agriculturally dominant livelihoods. (3) The farm labor, dependency ratio, agricultural income, supplemental income and locational conditions have negative impacts on the non-agricultural trend of farm household livelihood decisions, while off-farm labor, non-farm income, education level and the per capita amount of compensation have significant positive impacts on it.

Evolutionary process and mechanism of population hollowing out in rural villages in the farming-pastoral ecotone of Northern China: A case study of Yanchi County, Ningxia

The hollowing out of the rural population is one of the main reasons for declining rural areas. Studying the hollowing out of the rural population is of great significance in promoting the integrated development of urban and rural areas in the new era. This paper presents the mechanism of the rural development process and divides it into four stages: primary equilibrium, differentiation and divestment, decline or transformation, and urban-rural integration. This paper provides the spatial and temporal evolution patterns and driving factors of rural population hollowing out by analyzing spatial changes of 87 administrative villages in Yanchi County, Ningxia Province with ArcGIS. The results show that: (1) the degree of population hollowing out is unevenly distributed spatially, with highly hollowed areas mainly concentrated in the north where transportation is convenient, and the hollowed areas develop over time from point to linear along transportation routes; (2) the degree of population hollowing out is increasing, but the rate has slowed down; (3) rural population hollowing is influenced by physical geography, basic service facilities, and socio-economic, changing over time. This paper concludes that population hollowing out in rural villages is inevitable in the process of transition from a smallholder economy to modern agriculture. Hollowing out has resulted in rural land use changes, and may bring opportunities for large-scale agricultural operation and advances the development of urban-rural integration, under appropriate policy design and guidance. In the future, more attention should be paid to the new trends of return migration.

Analysis of Factors Influencing the Decision-Making Behavior of Beef Cattle Farmers: An Empirical Analysis Based on Logit-ISM Model.

The beef cattle industry is an important part of herbivorous animal husbandry and an important industry to enrich the dietary structure of residents and promote the income of farmers and herdsmen. The cow is an important foundation to support the healthy development of the beef cattle industry, which is related to the stability of cattle sources and the sustainable development of the industry. However, in recent years, the shortage of cows in our country has led to the shortage of cattle resources and the high price of calves, which has restricted the further development of our beef cattle industry. In order to explore the factors that affect the decision-making behavior behind cow breeding and to find the right policy to mobilize the enthusiasm for cow breeding, based on the field survey of five provinces (cities and regions), including Inner Mongolia Autonomous Region and Ningxia Hui Autonomous Region, this paper conducts an empirical analysis through the Logit ISM model. The results show that market expectation is the surface factor that directly affects the decision-making behavior of cow breeding. The influencing factors of the middle layer are policy propaganda, policy subsidies, breeding years, and feeding methods. The deep root factors are the age of the breeder, the amount of loan, and whether to plant feed crops. Based on this, this paper proposes that we should actively promote the importance of cow breeding, strengthen policy support for cow breeding, formulate scientific and reasonable subsidy policies for cows, innovate financial support methods to solve the problem of fund shortage of farmers, and develop forage resources and reduce the breeding cost of cows.

An Object- and Shapelet-Based Method for Mapping Planted Forest Dynamics from Landsat Time Series

Large-scale afforestation in arid and semi-arid areas with fragile ecosystems for the purpose of restoring degradation and mitigating climate change has raised issues of decreased groundwater recharge and ambiguous climatic benefits. An accurate planted forest mapping method is necessary to explore the impacts of afforestation expansion on fragile ecosystems. However, distinguishing planted forests from natural forests using remote sensing technology is not a trivial task due to their strong spectral similarities, even when assisted by phenological variables. In this study, we developed an object- and shapelet-based (OASB) method for mapping the planted forests of the Ningxia Hui Autonomous Region (NHAR), China in 2020 and for tracing the planting years between 1991 and 2020. The novel method consists of two components: (1) a simple non-iterative clustering to yield homogenous objects for building an improved time series; (2) a shapelet-based classification to distinguish the planted forests from the natural forests and to estimate the planting year, by detecting the temporal characteristics representing the planting activities. The created map accurately depicted the planted forests of the NHAR in 2020, with an overall accuracy of 87.3% (Kappa = 0.82). The area of the planted forest was counted as 0.56 million ha, accounting for 67% of the total forest area. Additionally, the planting year calendar (RMSE = 2.46 years) illustrated that the establishment of the planted forests matched the implemented ecological restoration initiatives over the past decades. Overall, the OASB has great potential for mapping the planted forests in the NHAR or other arid and semi-arid regions, and the map products derived from this method are conducive to evaluating forestry eco-engineering projects and facilitating the sustainable development of forest ecosystems.

Self-Reflection and Transformation Among Ningxia International Students in Malaysia

The study investigated the learning experiences and the adaptation process among Ningxia China international students studying in Malaysia. The paper aims to highlight the researcher’s self-reflection on the learning experience which led to self-transformation. The study employed a qualitative paradigm where a total of the ten participants were interviewed. Through a unique self-reflection during analysis, the researcher placed herself in the study and supported by ten other respondents. The researcher went through a rigorous search within herself. In addition, a set of semi-structured questions was used during the interview. The self-reflection of the researcher was conceptualized, interviews were transcribed and data were triangulated. Coding and constant comparison were adopted during data analysis. The findings showed the sub-themes of the learning experiences which led to self -transformation. The results yielded from this study contributed significantly towards the notion of transformation, study abroad and internationalisation. Thus, this implies that to able to succeed while studying abroad, it is important to understand the learning processes and the outcomes of the transformation within an individual.

Research on Water Rights Trading and Pricing Model between Agriculture and Energy Development in Ningxia, China

The contradiction between the supply and demand of water resources has become increasingly prominent, and water rights trading is an effective approach to increase the efficiency of water resource utilization and allocation so as to achieve sustainable use of water resources. Current transferring cost and price in China are both underestimated, taking into account the construction and maintenance fee of water conservation project and the irrigation risk compensation fee but ignoring the renovation and reconstruction fee of water conservation projects, and the compensation fee for farmers. This paper takes assignee rights, assignee capacity, and compensation to third parties into comprehensive considerations in Ningxia Hui Autonomous Region, where the contradictions between water, energy and food are most prominent in China. Tradable water use rights were analyzed based on a water transfer pricing model. The results show that there is an obvious negative correlation between shadow water price and water usage, and the shadow price of water resources is between 10.91 and 40.52 CNY/m3, which is an optimal solution under the constraint of water usage from 6.65 to 7.03 billion m3. The reasonable water transfer price is 10.91 CYN/m3, of which the earning of the agricultural assignor was 5.96 CNY/m3. This price guarantees the interests of the assignee and is also affordable to the assignee. This research provides a specific calculation method for the transfer pricing of water rights under non-market conditions, which is of important theoretically and has practical significance.

Effects of long-term ambient air pollution exposure on township-level pulmonary tuberculosis notification rates during 2005–2017 in Ningxia, China

Studies examining long-term effects of ambient air pollution exposure, measured as annual averages, on pulmonary tuberculosis (TB) incidence are scarce, particularly in endemic, rural settings. We performed a small-area study in Ningxia Hui Autonomous Region (NHAR), a high TB-burden area in rural China, using township-level (n = 358 non-overlapping townships) annual TB notification data (2005–2017). We aimed to determine if annual average concentrations of ambient air pollution (particulate matter <2·5 μm [PM2·5], nitrogen dioxide [NO2] ozone [O3]) were associated with TB notification rates (as a proxy for incidence). Air pollution effects on TB notification rates at township-level were estimated as incidence rate ratios (IRR), fitted using a generalised estimating equation (GEE) adjusted for covariates (age, sex, occupation, education, ethnicity, remoteness [urban or rural], household crowding and solid fuel use). A total of 38,942 TB notifications were reported in NHAR between 2005 and 2017. The mean annual TB notification rate was 67 (standard deviation [SD]; 7) per 100,000 people. Median concentrations of PM2·5, NO2, and O3 were 42 μg/m3 (interquartile range [IQR]; 38–48 μg/m3), 15 ppb (IQR; 12–16 ppb), and 56 ppb (IQR; 56–57 ppb), respectively. In single pollutant models, adjusted for covariates, an interquartile range (IQR) increase (10 μg/m3) in PM2·5 was significantly associated with higher TB notification rates (IRR: 1∙35; 95% CI: 1·25–1·48). Comparable effects on notifications of TB were observed for increases in NO2 exposure (IRR: 1·20 per IQR (4 ppb) increase; 95% CI: 1·08–1·31). Ground-level ozone was not associated with TB notification rate in any models. The observed effects were consistent over time, in multi-pollutant models, and appeared robust to additional adjustment for indicators of household crowding, solid fuel use and remoteness. More rigorous study designs are needed to understand if improving air quality has population-level benefits on TB disease incidence in endemic settings.

Field Test on Soybean-Urease Induced Calcite Precipitation (SICP) for Desert Sand Stabilization against the Wind-Induced Erosion

Soybean-urease induced calcite precipitation (SICP) is an effective method for the improvement of sand, which forms a biocemented layer on the desert sand surface to resist erosion induced by the wind. Under this study, field tests were carried out to determine how the SICP approach may enhance the resistance of the desert to wind-induced erosion and the durability of SICP treatment in southeastern margin of Tengger Desert, Ningxia Hui Autonomous Region, China. The experimental results demonstrated that the erosion resistance of desert sand was significantly enhanced due to the SICP treatment, and the improvement effect was enhanced with the increase of the biocement solution concentration and dosage and the number of treatment cycles. Furthermore, it was also found that the resistance of SICP-treated sand to erosion induced by the wind reduced as the development of time reduced. Based on the test results in this paper, larger biocement solution concentration and dosage and multiple treatment cycles are proposed in the areas where severe wind-induced erosion takes place in order to improve the ductility of SICP treatment.

Estimating farmers’ willingness to pay for photovoltaic industry to improve agricultural green resources and environment

Based on the consideration of the level of the regional radiation effect of the photovoltaic industry, four main regions were selected as case sites in Pingluo County, Ningxia Province, for this research. The study used the double-bound dichotomous CVM model and C-optimal design to revise the bidding value of the payment scheme that reduced the WTP range error. Five independent sub-sample questionnaires, including seven bidding value payment schemes, along with four internal range tests and six external range tests, were designed. The results showed that the comparison of the WTP for the improvement of agricultural resources and the environment among different independent sub-samples in the same region passed the external quantitative scope test, indicating that the questionnaire design, survey implementation, and WTP estimation results of the double-bound dichotomous CVM in this study were reliable. Saturation degree, diminishing marginal utility, and substitution effect are the main influencing factors of low marginal WTP added value and embedding effect. When the quantity range changes, the utility of respondents tends to saturate and marginal utility rapidly decreases. Influenced by the aforementioned factors, the sum of the independent estimates of the respondents on the WTP for the improvement of agricultural green resources and environment of the photovoltaic industry in the four research areas is 3.04 times the average value of the overall estimates of the four areas. In order to obtain and maintain the local photovoltaic industry for agricultural production resources and environmental improvement, the average WTP of each respondent was 99.80 yuan per year.