Groundwater Entrepreneurs in China: Selling Water to Meet the Demand for Water

The overall goal of our paper is to better understand the development of groundwater markets in northern China. In particular, we focus on the factors that determine the development of groundwater markets in our attempt to explain their 'breadth' and 'depth.' Based on a survey of 24 randomly sampled villages and 50 randomly sampled tubewells in two provinces (Hebei and Henan Province) in 2001 and a field survey of 68 randomly sampled villages in 4 provinces (Hebei, Henan, Shanxi, and Shaanxi) of northern China in 2004, our results show that groundwater markets in northern China have emerged and are developing rapidly. Our results show that groundwater markets in northern China are informal and localized. The markets have developed in a way in which they appear somewhat similar to markets that are found in South Asia. However, groundwater markets differ from markets in South Asia in other ways -- water sellers discriminate in pricing and they almost always work on a spot-market, cash basis (that is, there are no share or labor sharing arrangements as found in South Asia). Econometric results show that the privatization of tubewells is one of the most important driving factors that encourage the development of groundwater markets. Increasing water and land scarcity are also major determinants that induce the development of groundwater markets

Groundwater Entrepreneurs in China: Selling Water to Meet the Demand for Water

The overall goal of our paper is to better understand the development of groundwater markets in northern China. In particular, we focus on the factors that determine the development of groundwater markets in our attempt to explain their 'breadth' and 'depth.' Based on a survey of 24 randomly sampled villages and 50 randomly sampled tubewells in two provinces (Hebei and Henan Province) in 2001 and a field survey of 68 randomly sampled villages in 4 provinces (Hebei, Henan, Shanxi, and Shaanxi) of northern China in 2004, our results show that groundwater markets in northern China have emerged and are developing rapidly. Our results show that groundwater markets in northern China are informal and localized. The markets have developed in a way in which they appear somewhat similar to markets that are found in South Asia. However, groundwater markets differ from markets in South Asia in other wayswater sellers discriminate in pricing and they almost always work on a spot-market, cash basis (that is, there are no share or labor sharing arrangements as found in South Asia). Econometric results show that the privatization of tubewells is one of the most important driving factors that encourage the development of groundwater markets. Increasing water and land scarcity are also major determinants that induce the development of groundwater markets.Groundwater markets, Emergence, Characteristics, Determinants, northern China, Resource /Energy Economics and Policy, O53, Q15, Q25,

Probabilistic approach for systems of second order quasi-linear parabolic PDEs

AbstractUsing the stochastic representation for second order parabolic equations, we prove the existence of local smooth solutions in Sobolev spaces for a class of second order quasi-linear parabolic partial differential equations (possibly degenerate) with smooth coefficients. As a simple application, the rate of convergence for vanishing viscosity is proved to be O(νt). Moreover, using Bismutʼs formula, we also obtain a global existence result for non-degenerate semi-linear parabolic equations. In particular, multi-dimensional Burgers equations are covered

A lightweight network for photovoltaic cell defect detection in electroluminescence images based on neural architecture search and knowledge distillation

Nowadays, the rapid development of photovoltaic(PV) power stations requires increasingly reliable maintenance and fault diagnosis of PV modules in the field. Due to the effectiveness, convolutional neural network (CNN) has been widely used in the existing automatic defect detection of PV cells. However, the parameters of these CNN-based models are very large, which require stringent hardware resources and it is difficult to be applied in actual industrial projects. To solve these problems, we propose a novel lightweight high-performance model for automatic defect detection of PV cells in electroluminescence(EL) images based on neural architecture search and knowledge distillation. To auto-design an effective lightweight model, we introduce neural architecture search to the field of PV cell defect classification for the first time. Since the defect can be any size, we design a proper search structure of network to better exploit the multi-scale characteristic. To improve the overall performance of the searched lightweight model, we further transfer the knowledge learned by the existing pre-trained large-scale model based on knowledge distillation. Different kinds of knowledge are exploited and transferred, including attention information, feature information, logit information and task-oriented information. Experiments have demonstrated that the proposed model achieves the state-of-the-art performance on the public PV cell dataset of EL images under online data augmentation with accuracy of 91.74% and the parameters of 1.85M. The proposed lightweight high-performance model can be easily deployed to the end devices of the actual industrial projects and retain the accuracy.Comment: 12 pages, 7 figure

Can China continue feeding itself ? the impact of climate change on agriculture

Several studies addressing the supply and demand for food in China suggest that the nation can largely meet its needs in the coming decades. However, these studies do not consider the effects of climate change. This paper examines whether near future expected changes in climate are likely to alter this picture. The authors analyze the effect of temperature and precipitation on net crop revenues using a cross section consisting of both rainfed and irrigated farms. Based on survey data from 8,405 households across 28 provinces, the results of the Ricardian analysis demonstrate that global warming is likely to be harmful to China but the impacts are likely to be very different in each region. The mid latitude region of China may benefit from warming but the southern and northern regions are likely to be damaged by warming. More precipitation is beneficial to Chinese farmers except in the wet southeast. Irrigated and rainfed farmers have similar responses to precipitation but not to temperature. Warmer temperatures may benefit irrigated farms but they are likely to harm rainfed farms. Finally, seasonal effects vary and are offsetting. Although we were able to measure the direct effect of precipitation and temperature, we could not capture the effects of change in water flow which will be very important in China. Can China continue feeding itself if climate changes? Based on the empirical results, the likely gains realized by some farmers will nearly offset the losses that will occur to other farmers in China. If future climate scenarios lead to significant reductions in water, there may be large damages not addressed in this study.Climate Change,Crops&Crop Management Systems,Global Environment Facility,Common Property Resource Development,Rural Development Knowledge&Information Systems

A STUDY ON FOUR ANTIOXIDATION EFFECTS OF LYCIUM BARBARUM POLYSACCHARIDES IN VITRO

The objective of the study was to investigate the in vitro antioxidation activity of lycium barbarum polysaccharides (LBP). Ultraviolet spectrophotometry was adopted to determine the capability of LBP to clear superoxide anions, hydroxyl radicals, DPPH free radicals and ABTS free radicals. The result showed that the law for LBP to clear superoxide anions, hydroxyl radicals and DPPH free radicals was that the clearance rate increased gradually with the increase of the concentration, and when the concentration reached a certain value, the clearance rate leveled off, while the IC50 for clearing ABTS free radicals was 47.158±6.231μg/ml. The study concluded that LBP is a good in vitro antioxidant

First age- and gender-matched case-control study in Australia examining the possible association between toxoplasma gondii Infection and type 2 diabetes mellitus: The Busselton Health Study

An emerging field of research is starting to examine the association of infectious pathogens with type 2 diabetes mellitus (T2DM). An understudied parasite of interest is Toxoplasma gondii. Globally, very few studies have been conducted to investigate this association. Additionally, very little data exists on the prevalence of T. gondii in the general Australian population. Our group sought to determine the prevalence, association, and risk factors between T. gondii infection and T2DM from a representative Australian human population. Through a cross-sectional, age-A nd gender-matched case-control study, 150 subjects with T2DM together with 150 control subjects from the Busselton Health Study cohort were investigated. Sera samples were tested for the presence of anti-T. gondii IgG and IgM antibodies using enzyme-linked immunosorbent assays. Survey-derived data were also analyzed to evaluate associated risk factors. The IgG seroprevalence was found to be 62% and 66% for the T2DM and control groups, respectively (OR:0.84; p=0.471). IgM antibodies were detected in 5% of the T2DM patients and in 10% of the controls (OR=0.51; p=0.135). There were no significant differences between male and female IgG seroprevalence rates for both groups (OR:0.88, 0.80; p=0.723). The IgG seropositivity rate increased significantly in T2DM patients aged 45-84 years in comparison to those aged 18-44 years (p\u3c 0.05), but this was not observed in the control subjects. No risk factors were associated with T. gondii seropositivity in both groups. The first Australian study of its kind found T. gondii infection in Western Australia to be highly prevalent. The results also showed that there is no serological evidence of an association between T. gondii infection and T2DM in the studied subjects. Australian health authorities should focus on raising awareness of toxoplasma infection and target T. gondii transmission control. Further studies are needed to clarify the role of T. gondii in T2DM. © 2020 Aus Molan et al

Vascular endothelial growth factor and the risk of venous thromboembolism: A genetic correlation and two-sample Mendelian randomization study

Background: The relationship between vascular endothelial growth factor (VEGF) and the risk of venous thromboembolism (VTE) has always been one of the concerns in the medical field. However, the causal inferences from published observational studies on this issue may be affected by confounders or reverse causality. We performed a two-sample bidirectional Mendelian randomization (MR) to infer the associations between VEGF and VTE. Methods: Summary statistics from genome-wide association studies (GWAS) for VEGF and VTE were obtained from published meta-analysis studies and the FinnGen consortium, respectively. Independent genetic variables significantly associated with exposure were selected as instrumental variables. Linkage disequilibrium score regression (LDSC) and five robust MR analytical approaches were conducted to estimate the genetic correlations and causal inference. The MR-Egger intercept, Cochran’s Q, and MR pleiotropy residual sum and outlier (MR-PRESSO) were performed to evaluate the horizontal pleiotropy, heterogeneities, and stability of these genetic variants on outcomes. Notably, replication analyses were performed using different subgroups of VTE. Results: LDSC failed to identify genetic correlations between VEGF and VTE. Based on 9 SNPs, the circulating VEGF level was positively related to the risk of VTE using inverse variance weighting (IVW) method (odds ratio (OR) = 1.064, 95 % confidence interval (CI), 1.009 – 1.122). Reverse MR analyses showed that genetic liability for VTE was not associated with increased VEGF level (β = -0.021, 95 % CI, -0.087-0.045). Pleiotropy-robust methods indicated no bias in any estimates. Conclusions: Our findings failed to detect coheritability between VEGF and VTE. The suggestive positive effect of the higher VEGF level on the VTE risk may have clinical implications, suggesting that VEGF as a possible predictor and therapeutic target for VTE prevention need to be further warranted

Survey of Research on Personalized News Recommendation Approaches

Personalized news recommendation is an important technology to help users obtain the news information they are interested in and alleviate information overload. In recent years, with the development of information technology and society, personalized news recommendation has been increasingly widely studied, and has achieved remarkable success in improving the news reading experience of users. This paper aims to systematically summarize personalized news recommendation methods based on deep learning. Firstly, it introduces personalized news recommendation methods and analyzes their characteristics and influencing factors. Then, the overall framework of personalized news recommendation is given, and the personalized news recommendation methods based on deep learning are analyzed and summarized. On this basis, it focuses on personalized news recommendation methods based on graph structure learning, including user-news interaction graph, knowledge graph and social relationship graph. Finally, it analyzes the challenges of the current personalized news recommendation, discusses how to solve the problems of data sparsity, model interpretability, diversity of recommendation results and news privacy protection in personalized news recommendation system, and puts forward more specific and operable research ideas in the future research direction

Association between telomere length in peripheral blood leukocytes and risk of ischemic stroke in a Han Chinese population: A linear and non‑linear Mendelian randomization analysis

Background: Many contradictory conclusions pertaining to the telomere length in peripheral leukocyte chromosomes as a potential biomarker for ischemic stroke (IS) risk have been reported by the various observational studies in previous years. This study aims to investigate whether the leukocyte telomere length is associated with an increased IS risk or not, based on the Mendelian randomization (MR) approach. Methods: Based on the NHGRI-EBI GWAS Catalog database, the Chinese online genetic database as well as the previous published studies, twelve single nucleotide polymorphisms (SNPs) with minor allele frequency ≥ 0.05 were selected and the leukocyte telomere length was measured in 431 first-ever IS patients and 304 healthy controls (quantitative polymerase chain reaction). To explore linear and non-linear effect of telomere length on the IS risk, we preformed the linear MR analysis (the inverse-variance weighted method, the maximum likelihood method, and the mode-based estimation method), and the non-linear MR analysis (semiparametric method with three tests for non-linearity, including the quadratic test, Cochran’s Q test, and the fractional polynomial test). Results: Two verified SNPs (rs11125529 and rs412658) were chosen as instrumental variables. In linear MR analysis, the adjusted odds ratios and 95% confidence intervals of IS for genetically predicted telomere lengths, based on the two SNPs, were 1.312 (0.979 to 1.759), 1.326 (0.932 to 1.888) and 1.226 (0.844 to 1.781) for the inverse-variance weighted method, the maximum likelihood method, and the mode-based estimation method, respectively. Three tests for nonlinearity failed to reject the null exactly, indicating that the relationship between telomere length and IS risk is unlikely to be non-linear. Conclusion: This MR study based on individual data does not provide strong evidence for a positive linear or non-linear effect of telomere length on the IS risk