The abolition of Agricultural Tax in 2005 was a major policy of the early Hu–Wen administration. But how and why did it happen? Drawing on abundant media reports, archive documents and internal ...speeches by key policymakers, as well as on the author's interviews, this article argues that this reform was pushed through (the “how”) by “principle-guided policy experimentation” with origins in the period of Jiang Zemin's leadership. Not only does this show policy continuities from the Jiang–Zhu era into the Hu–Wen period, it also reveals a different process of policy experimentation from that identified by Sebastian Heilmann in the economic policy arena. Under principle-guided policy experimentation, Chinese central decision makers first reached consensus on the principle of the Rural Tax and Fee Reform (RTFR) drawing on policy learning from prior bottom-up local experimentation, and then formulated and implemented an experimental programme from the top-down, funding it in order to encourage local governments to participate. The evidence suggests that international, political (rural instability), economic and fiscal considerations came to explain leaders’ decisions (the “why”) on tax reform as much as their individual preferences. 2005 年废除农业税是胡温执政前期实施的一项重大社会改革。这项改革究竟是怎样实施的，为什么会实施这样的改革? 本文把这项发端于江泽民时代的农村税费改革的政策过程概括为“原则性政策试验”, 认为这项改革不仅凸显了胡温和江朱时代中央政策的延续性，同时还揭示出一种与韩博天在中国经济改革领域所发现的政策试验过程不同的模式。原则性政策试验显示，中央最高决策层在前期地方性改革试点的基础上，首先对实施农村税费改革的基本原则达成共识，然后由中央自上而下地设计和推行试点方案，由点到面，最终形成全国性的政策。证据还表明，国际因素、政治因素（农村稳定）、财政经济因素，以及领导人的个人偏好都对中央决策层实施这项改革起到关键作用。
•Excessive exposure of eye to blue light tends to cause photochemical damage.•The retina and ocular surface are vulnerable to blue light hazard.•The main mechanisms of hazard are oxidative stress and ...mitochondrial apoptosis.•The main treatments include physical protection, antioxidant and gene therapy.
The risk of blue light exposure to human health has attracted increased research attention. Blue light, with relatively high energy, can cause irreversible photochemical damage to eye tissue. Excessive exposure of the eye to blue light tends to cause a series of alterations, such as oxidative stress, mitochondrial apoptosis, inflammatory apoptosis, mitochondrial apoptosis and DNA damage, resulting in the development of dry eye disease, glaucoma, and keratitis. Accordingly, physical protection, chemical and pharmaceutical protective measures, gene therapy, and other methods are widely used in the clinical treatment of blue light hazard. We reviewed the studies on possible blue light-induced signaling pathways and mechanisms in the eye and summarized the therapeutic approaches to addressing blue light hazard.
Large-scale (or massive) multiple-input multiple-out put (MIMO) is expected to be one of the key technologies in next-generation multi-user cellular systems based on the upcoming 3GPP LTE Release 12 ...standard, for example. In this work, we propose-to the best of our knowledge-the first VLSI design enabling high-throughput data detection in single-carrier frequency-division multiple access (SC-FDMA)-based large-scale MIMO systems. We propose a new approximate matrix inversion algorithm relying on a Neumann series expansion, which substantially reduces the complexity of linear data detection. We analyze the associated error, and we compare its performance and complexity to those of an exact linear detector. We present corresponding VLSI architectures, which perform exact and approximate soft-output detection for large-scale MIMO systems with various antenna/user configurations. Reference implementation results for a Xilinx Virtex-7 XC7VX980T FPGA show that our designs are able to achieve more than 600 Mb/s for a 128 antenna, 8 user 3GPP LTE-based large-scale MIMO system. We finally provide a performance/complexity trade-off comparison using the presented FPGA designs, which reveals that the detector circuit of choice is determined by the ratio between BS antennas and users, as well as the desired error-rate performance.
Colorectal cancer (CRC) is one of the most common cancers worldwide and a leading cause of carcinogenic death. To date, surgical resection is regarded as the gold standard by the operator for ...clinical decisions. Because conventional tissue biopsy is invasive and only a small sample can sometimes be obtained, it is unable to represent the heterogeneity of tumor or dynamically monitor tumor progression. Therefore, there is an urgent need to find a new minimally invasive or noninvasive diagnostic strategy to detect CRC at an early stage and monitor CRC recurrence. Over the past years, a new diagnostic concept called "liquid biopsy" has gained much attention. Liquid biopsy is noninvasive, allowing repeated analysis and real-time monitoring of tumor recurrence, metastasis or therapeutic responses. With the advanced development of new molecular techniques in CRC, circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), exosomes, and tumor-educated platelet (TEP) detection have achieved interesting and inspiring results as the most prominent liquid biopsy markers. In this review, we focused on some clinical applications of CTCs, ctDNA, exosomes and TEPs and discuss promising future applications to solve unmet clinical needs in CRC patients.
•Mechanical stimulation improves the proliferation and cartilage phenotype.•Co-culture with mesenchymal stem cells improves the proliferation of chondrocytes.•Proper mechanical stimulation co-culture ...is effective for expanding the cells.
Mesenchymal stem cells and chondrocytes are an important source of the cells for cartilage tissue engineering. Therefore, the culture and expansion methods of these cells need to be improved to overcome the aging of chondrocytes and induced chondrogenic differentiation of mesenchymal stem cells. The aim of this study was to expand the cells for cartilage tissue engineering by combining the advantages of growing cells in co-culture and under a mechanically-stimulated environment. Rabbit chondrocytes and co-cultured cells (bone mesenchymal stem cells and chondrocytes) were subjected to cyclic sinusoidal dynamic tensile mechanical stimulationusing the FX-4000 tension system. Chondrocyte proliferation was assayed by flow cytometry and CFSE labeling. The cell cartilage phenotype was determined by detecting GAG, collagen II and TGF-β1 protein expression by ELISA and the Col2α1, TGF-β1 and Sox9 gene expression by RT-PCR. The results show that the co-culture improved both the proliferation ability of chondrocytes and the cartilage phenotype of co-cultured cells. A proper cyclic sinusoidal dynamic tensile mechanical stimulation improved the proliferation ability and cartilage phenotype of chondrocytes and co-cultured cells. These results suggest that the co-culture of mesenchymal stem cells with chondrocytes and proper mechanical stimulation may be an appropriate way to rapidly expand the cells that have an improved cartilage phenotype for cartilage tissue engineering.
With a requirement of miniaturization in modern vibrating screens, the vibration synchronization method can no longer meet the process demand, so the controlled synchronization method is introduced ...in the vibrating screen to achieve zero phase error state and realize the purpose of increasing the amplitude. In this article, the controlled synchronization of a vibrating screen driven by two motors based on improved sliding mode controlling method is investigated. Firstly, according to the theory of mechanical dynamics, the motion state of the vibrating screen is simplified as the electromechanical coupling dynamical model of a vibrating system driven by two inductor motors. And then the synchronization conditions and stability criterion of the vibrating system are derived and numerically analyzed. Based on a master-slave controlling strategy, the controllers of two motors are respectively designed with Super-Twisting sliding mode control (ST-SMC) and backstepping second-order complementary sliding mode control (BSOCSMC), while the uncertainty is estimated by an adaptive radial basis function neural network (ARBFNN). In addition, Lyapunov stability analysis is performed on the two controllers to prove their stability theoretically. Finally, simulation analysis is conducted based on the dynamics model in this paper.
•Spatio-temporal variation of soil water content (SWC) was investigated for typical hillslopes.•Representative locations of mean SWC were identified by the methods of relative differences.•Temporal ...stability of SWC differed notably with slope aspect, position, and soil depth.•Identified representative locations performed well in predicting the mean SWC.•Soil particle and SOC contents greatly affect the spatio-temporal distribution of SWC.
Spatio-temporal variability in soil water content (SWC) increases the difficulty in soil water resource management and vegetation construction in arid and semi-arid regions. Our objectives were to investigate the spatial variability and temporal stability of SWC and identify representative locations for reliably predicting the profile mean SWC (MSWC) of a 33-year-old Caragana korshinskii plantation on typical sunny and shady hillslopes on the Loess Plateau, China. The profile SWC (0–180 cm) in three sampling belts and five hillslope positions (upper position, UP; upper-middle position, UMP; middle position, MP; lower-middle position, LMP; lower position, LP) were measured 27 times for both the hillslopes in 2018 and 2019. The mean relative difference (MRD), the standard deviation of the MRD (SDRD), and an index of temporal stability (ITS) were used to identify representative locations of the MSWC. The results indicated that the SWC presented different horizontal but similar vertical change trends in the five hillslope positions. The profile MSWC on the sunny hillslope (8.89%) was lower than that on the shady hillslope (9.44%). The mean Spearman correlation coefficients of the temporal patterns ranged from 0.6 to 0.8 for the five soil layers on both hillslopes. The characteristics of temporal stability differed in both temporal persistence and the representative locations for the five soil layers on the sunny and shady hillslopes. The mean ITS values generally decreased with increasing soil depth. Ultimately, the representative locations for estimating the profile MSWC were determined to be the MP-2 location on the sunny hillslope and the MP-3 location on the shady hillslope based on the MRD, SDRD, and ITS values. The representative locations have the lowest ITS values and represent the MSWC accurately, with root mean square error (RMSE) and mean error (ME) values of less than 1%. In addition, the soil organic carbon, clay, silt, and sand contents greatly affect the spatial and temporal distributions of the soil water at the hillslope scale. Our study provides a rapid and accurate method for determining profile MSWC in C. korshinskii plantations on typical sunny and shady hillslopes and could also support valuable guidance for the rational management of hillslope-scale SWC resources for similar dry regions.
Robot vision technology based on binocular vision holds tremendous potential for development in various fields, including 3D scene reconstruction, target detection, and autonomous driving. However, ...current binocular vision methods used in robotics engineering have limitations such as high costs, complex algorithms, and low reliability of the generated disparity map in different scenes. To overcome these challenges, a cross-domain stereo matching algorithm for binocular vision based on transfer learning was proposed in this paper, named Cross-Domain Adaptation and Transfer Learning Network (Ct-Net), which has shown valuable results in multiple robot scenes. First, this paper introduces a General Feature Extractor to extract rich general feature information for domain adaptive stereo matching tasks. Then, a feature adapter is used to adapt the general features to the stereo matching network. Furthermore, a Domain Adaptive Cost Optimization Module is designed to optimize the matching cost. A disparity score prediction module was also embedded to adaptively adjust the search range of disparity and optimize the cost distribution. The overall framework was trained using a phased strategy, and ablation experiments were conducted to verify the effectiveness of the training strategy. Compared with the prototype PSMNet, on KITTI 2015 benchmark, the 3PE-fg of Ct-Net in all regions and non-occluded regions decreased by 19.3 and 21.1% respectively, meanwhile, on the Middlebury dataset, the proposed algorithm improves the sample error rate at least 28.4%, which is the Staircase sample. The quantitative and qualitative results obtained from Middlebury, Apollo, and other datasets demonstrate that Ct-Net significantly improves the cross-domain performance of stereo matching. Stereo matching experiments in real-world scenes have shown that it can effectively address visual tasks in multiple scenes.
Next-generation flexible electronics require highly stretchable and transparent electrodes. Few electronic conductors are both transparent and stretchable, and even fewer can be cyclically stretched ...to a large strain without causing fatigue. Fatigue, which is often an issue of strained materials causing failure at low strain levels of cyclic loading, is detrimental to materials under repeated loads in practical applications. Here we show that optimizing topology and/or tuning adhesion of metal nanomeshes can significantly improve stretchability and eliminate strain fatigue. The ligaments in an Au nanomesh on a slippery substrate can locally shift to relax stress upon stretching and return to the original configuration when stress is removed. The Au nanomesh keeps a low sheet resistance and high transparency, comparable to those of strain-free indium tin oxide films, when the nanomesh is stretched to a strain of 300%, or shows no fatigue after 50,000 stretches to a strain up to 150%. Moreover, the Au nanomesh is biocompatible and penetrable to biomacromolecules in fluid. The superstretchable transparent conductors are highly desirable for stretchable photoelectronics, electronic skins, and implantable electronics.
•Biogas production was enhanced by co-digestion of rice straw with other materials.•The optimal ratio of kitchen waste, pig manure and rice straw is 0.4:1.6:1.•The maximum biogas yield of 674.4L/kgVS ...was obtained.•VFA inhibition occurred when kitchen waste content was more than 26%.•The dominant VFA were propionate and acetate in successful reactors.
In order to investigate the effect of feedstock ratios in biogas production, anaerobic co-digestions of rice straw with kitchen waste and pig manure were carried out. A series of single-stage batch mesophilic (37±1°C) anaerobic digestions were performed at a substrate concentration of 54g/L based on volatile solids (VS). The results showed that the optimal ratio of kitchen waste, pig manure, and rice straw was 0.4:1.6:1, for which the C/N ratio was 21.7. The methane content was 45.9–70.0% and rate of VS reduction was 55.8%. The biogas yield of 674.4L/kgVS was higher than that of the digestion of rice straw or pig manure alone by 71.67% and 10.41%, respectively. Inhibition of biogas production by volatile fatty acids (VFA) occurred when the addition of kitchen waste was greater than 26%. The VFA analysis showed that, in the reactors that successfully produced biogas, the dominant intermediate metabolites were propionate and acetate, while they were lactic acid, acetate, and propionate in the others.
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