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57 نتائج ل "Hua, Chunlin"
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Effects of Policy for Controlling Agricultural Non-Point Source Pollution in China: From a Perspective of Regional and Policy Measures Differences
The concerns about the contradiction between agricultural production and Agricultural Non-Point (ANPS) pollution has become increased with economic development in China. Government interventions are key to controlling ANPS pollution through the establishment of laws and policies. This paper uses the entropy method to calculate the emissions amount of ANPS pollution and policy strength of 31 provinces from 2010 to 2019 in China. The dynamic panel data model with system generalized moment is used to estimate the impacts of policies with different measures on ANPS pollution emission. According to our findings, China's policies have been helpful in controlling ANPS pollution though there are important regional differences. Moreover, four types of policy measures all contribute to the reduction in ANPS pollution. These findings improve our understanding of the relationship between policies and ANPS pollution in the analyzed period, thus providing support for the formulation of pollution management strategies in the next stage.
An Ex-Post Evaluation of Agricultural Extension Programs for Reducing Fertilizer Input in Shaanxi, China
It is difficult to control agricultural Non-point Source (NPS) pollution, caused by overusing of chemical fertilizer, through laws alone. An agricultural extension program is an alternative way to reduce fertilizer input. This paper estimates the average change in fertilizer use of farmers, which is attributable to their participation in the agricultural extension program. The Inverse-Probability Weighted matching method is used to evaluate the average treatment effect for the farmers who engaged in the program and, to a limited extent, evaluate the impact of individual elements of the program. Surprisingly, we find that farmer-to-farmer training may have had a counterproductive effect while the posters may be the most effective program element in reducing fertilizer use in the context.
‘Drop, cover and hold on’ or ‘triangle of life’ attributes of information sources influencing earthquake protective actions
A well-known fact is that an earthquake or earth shaking does not cause injuries and deaths. rather, buildings and infrastructure systems collapsing on people do. Hence, reputable government organizations from countries prone to high earthquake risks are heavily invested in advising their populations on immediate lifesaving protective actions (PAs). One such action is the ‘Drop, Cover and Hold on’ strategy proven to have saved countless lives. unfortunately, in recent years another action known as the ‘Triangle of life’ has been trolled through internet sites and hearsay. It is believed that adopting such an unsubstantiated erroneous action is likely to put people at greater risk during an earthquake. Thus, there is a need to extend studies to understand factors that influence people’s decisions to take certain PAs over another for earthquakes. This research does that through an empirical study of 647 residents from mianyang City in the Sichuan province of China. The results indicate that if a PA is easy to understand, mentioned often by multiple sources and easy to access, then people will adopt it. but a striking finding is that people are also likely to be influenced by wrong information, depending on who is providing such information and through which medium (e.g. social media). These findings suggest that the Chinese government needs to provide gate keepers who are dedicated, trained personnel who can monitor misinformation on various Internet sites and address them. In parallel they can provide regular, up to date public advisories on immediate PA through multiple legitimate government, private and non-profit sector sources and channels.
FAM20A is a golgi-localized Type II transmembrane protein
Family with sequence similarity 20, member A (FAM20A) is a pseudo-kinase in the secretory pathway and is essential for enamel formation in humans. Here we examine if FAM20A is a membrane-associated protein. We show that the full-length FAM20A can be purified from HEK293 cells transfected with a FAM20A-expresing construct. Further, it is only found in the membrane fraction, but not in the soluble fraction, of cell lysate. Consistently, it is not secreted out of the expressing cells. Moreover, it is co-localized with GM130, a cis-Golgi network marker, and membrane topology analysis indicates that it has its C-terminus oriented towards the lumen of the organelle. Our results support that FAM20A is a Type II transmembrane protein within the secretory compartments.
Wheel-Rail Contact-Induced Impact Vibration Analysis for Switch Rails Based on the VMD-SS Method
When trains pass through damaged switch rails, rail head damage will change wheel–rail contact states from rolling frictions to unsteady contacts, which will result in impact vibrations and threaten structural safeties. In addition, under approaching and moving away rolling contact excitations and complex wheel–rail contacts, the non-stationary vibrations make it difficult to extract and analyze impact vibrations. In view of the above problems, this paper proposes a variational-mode-decomposition (VMD)-spectral-subtraction (SS)-based impact vibration extraction method. Firstly, the time domain feature analysis method is applied to calculate the time moments that the wheels pass joints, and to correct vehicle velocities. This can help estimate and confine impact vibration distribution ranges. Then, the stationary intrinsic mode function (IMF) components of the impact vibration are decomposed and analyzed with the VMD method. Finally, impact vibrations are further filtered with the SS method. For rail head damage with different dimensions, under different velocity experiments, the frequency and amplitude features of the impact vibrations are analyzed. Experimental results show that, in low-velocity scenarios, the proposed VMD–SS–based method can extract impact vibrations, the frequency features are mainly concentrated in 3500–5000 Hz, and the frequency and peak-to-peak features increase with the increase in excitation velocities.
Molecular and Functional Characterization of Pheromone Binding Protein 2 from Cyrtotrachelus buqueti (Coleoptera: Curculionidae)
Pheromone-binding proteins (PBPs) play important roles in binding and transporting sex pheromones. However, the genes identified in coleopteran insects and their information sensing mechanism are largely unknown. (Coleoptera: Curculionidae) is a major insect pest of bamboo plantations. In this study, a novel gene, , from was functionally characterized. was more abundantly expressed in the antennae of both sexes than other body parts, and its expression level was significantly male-biased. Fluorescence competitive binding assays showed that CbuqPBP2 exhibited the strongest binding affinity to dibutyl phthalate ( = 6.32 μM), followed by styrene ( = 11.37 μM), among twelve volatiles. CbuqPBP2, on the other hand, showed high binding affinity to linalool ( = 10.55), the main volatile of host plant . Furthermore, molecular docking also demonstrated the strong binding ability of CbuqPBP2 to dibutyl phthalate, styrene, and linalool, with binding energy values of -5.7, -6.6, and -6.0 kcal/mol, respectively, and hydrophobic interactions were the prevailing forces. The knockdown of expression via RNA interference significantly reduced the electroantennography (EAG) responses of male adults to dibutyl phthalate and styrene. In conclusion, these results will be conducive to understanding the olfactory mechanisms of and promoting the development of novel strategies for controlling this insect pest.
Transgenic expression of dentin phosphoprotein (DPP) partially rescued the dentin defects of DSPP-null mice
Mutations in the dentin sialophosphoprotein (DSPP) gene cause dentinogenesis imperfecta. After synthesis, DSPP is proteolytically processed into NH2- and COOH-terminal fragments. The NH2-terminal fragment of DSPP is highly glycosylated but not phosphorylated, whereas the COOH-terminal fragment (named \"dentin phosphoprotein\" or \"DPP\") is highly phosphorylated but not glycosylated. These two fragments are believed to perform distinct roles in dentin formation. To analyze the functions of DPP in dentinogenesis, we created \"Dspp-/-;DPP Tg mice\", which expressed transgenic DPP driven by a Type I collagen promoter but lacked the endogenous Dspp gene. We characterized the dentin of the Dspp-/-;DPP Tg mice using X-ray radiography, histology, scanning electron microscopy, double fluorochrome labeling, immunohistochemistry and in situ hybridization. Micro-computed tomography analyses revealed that at postnatal 6 months, the transgenic expression of DPP increased the dentin thickness of the Dspp-null mice by 97.1% and restored the dentin material density by 29.5%. Histological analyses showed that the Dspp-null mice manifested an abnormal widening of the predentin while the predentin in Dspp-/-;DPP Tg mice was narrower than in the Dspp-null mice. Scanning electron microscopy analyses showed that the dentinal tubules in the Dspp-/-;DPP Tg mice were better organized than in the Dspp-null mice. The double fluorochrome labeling analyses demonstrated that the dentin mineral deposition rate in the Dspp-/-;DPP Tg mice was significantly improved compared to that in the Dspp-null mice. These findings indicate that the transgenic expression of DPP partially rescued the dentin defects of the DSPP-null mice, suggesting that DPP may promote dentin formation and that the coordinated actions between DPP and the NH2-terminal fragment of DSPP may be necessary for dentinogenesis.
A novel linear uncertainty propagation method for nonlinear dynamics with interval process
Interval process is a preferable model for time-varying uncertainty propagation of dynamic systems when only the range of uncertainties can be obtained. However, for nonlinear systems, except for Monte Carlo (MC) simulation, there are still few efficient uncertainty propagation methods under the interval process model. This paper develops a non-intrusive and semi-analytical uncertainty propagation method, named the “convex model linearization method (CMLM),” by constructing a linearization formulation of a nonlinear system in a non-probabilistic sense. First, the criterion to evaluate the difference between the original system and the linearization formulation is derived, represented by the discrepancy of middle point, radius and correlations of response. By minimizing these three parameters, the coefficients of linear equations will be optimized to obtain the linearization formulation of the original system. Then, analytical equations are built to calculate uncertainty response under the interval process, without time-consuming analysis of the original system. To further improve the efficiency of the linearization process, Chebyshev polynomial is introduced to approximate the nonlinear dynamic analysis. Two numerical examples of duffing oscillators and vehicle rides are set to test the proposed CMLM. Compared to the MC method, with comparable uncertainty response precision, the CMLM just needs 1–10% times of dynamic analyses of the nonlinear system. Furthermore, a practical launch vehicle ascent trajectory problem with black-box dynamics is solved by, respectively, the CMLM and MC method. The results verify the capacity of the CMLM to deal with black-box problems and show that the CMLM performs better in terms of accuracy, efficiency and robustness.
Genome sequence of the progenitor of wheat A subgenome Triticum urartu
Triticum urartu (diploid, AA) is the progenitor of the A subgenome of tetraploid (Triticum turgidum, AABB) and hexaploid (Triticum aestivum, AABBDD) wheat . Genomic studies of T. urartu have been useful for investigating the structure, function and evolution of polyploid wheat genomes. Here we report the generation of a high-quality genome sequence of T. urartu by combining bacterial artificial chromosome (BAC)-by-BAC sequencing, single molecule real-time whole-genome shotgun sequencing , linked reads and optical mapping . We assembled seven chromosome-scale pseudomolecules and identified protein-coding genes, and we suggest a model for the evolution of T. urartu chromosomes. Comparative analyses with genomes of other grasses showed gene loss and amplification in the numbers of transposable elements in the T. urartu genome. Population genomics analysis of 147 T. urartu accessions from across the Fertile Crescent showed clustering of three groups, with differences in altitude and biostress, such as powdery mildew disease. The T. urartu genome assembly provides a valuable resource for studying genetic variation in wheat and related grasses, and promises to facilitate the discovery of genes that could be useful for wheat improvement.
Maintenance of stemness by miR-589-5p in hepatocellular carcinoma cells promotes chemoresistance via STAT3 signaling
The strength and duration of STAT3 signaling are tightly controlled by multiple negative feedback mechanisms under physical conditions. However, how these serial feedback loops are simultaneously disrupted in cancers, leading to constitutive activation of STAT3 signaling in hepatocellular carcinoma (HCC), remains obscure. Here we report that miR-589-5p is elevated in HCC tissues, which is caused by recurrent gains. Overexpression of miR-589-5p correlates with poor overall and relapse-free survival in HCC patients. Upregulating miR-589-5p enhances spheroid formation ability, fraction of CD133 positive and side population cells, expression of cancer stem cell factors and the mitochondrial potential, and represses the apoptosis induced by doxorubicin in vitro and tumorigenicity in vivo in HCC cells; conversely, silencing miR-589-5p yields an opposite effect. Our findings further demonstrate miR-589-5p promotes the cancer stem cell characteristics and chemoresistance via targeting multiple negative regulators of STAT3 signaling pathway, including SOCS2, SOCS5, PTPN1 and PTPN11, leading to constitutive activation of STAT3 signaling. Collectively, our results unravel a novel mechanism by which miR-589-5p promotes the maintenance of stemness and chemoresistance in HCC, providing a potential rational registry of anti-miR-589-5p combining with conventional chemotherapy against HCC.