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This study analyzes the change characteristics of compound extreme events (CEEs) of temperature and precipitation (including warm‐wet, warm‐dry, cold‐wet and cold‐dry) in China on interannual and interdecadal scales between 1901 and 2019. The results demonstrate a long‐term increasing trend and interdecadal oscillations in CEEs total frequency. However, the frequency of each type of CEEs changes in a different manner compared with total CEEs frequency. There are fewer CEEs but increasing warm‐dry during 1901–1950. The period 1951–1995 are characterized by frequent cold CEEs (cold‐wet and cold‐dry), cold‐wet are largely distributed in most areas except for northeast and coastal areas of China, while cold‐dry are distributed in most areas except for the northwest regions of China. There are frequent warm CEEs (warm‐wet and warm‐dry) and fewer cold CEEs during 1996–2019. Warm‐wet frequently occurs in the Tibetan Plateau and northwest China, and warm‐dry mainly concentrates in southwest and northern China during this period. The frequency of warm‐dry and cold‐wet were higher than that of warm‐wet and cold‐dry over the past 119 years, whereas warm‐wet increased fastest in the northwest region after 1996, consistent with the warming and wetting characteristics in the northwest region of China. Further study show that long‐term change and low frequency oscillations have the greatest impact on CEEs among different time scale factors. Furthermore, the temperature rise caused by climate change affects the interdecadal characteristics of CEEs in China through the changes of circulation fields such as East Asian trough and subtropical high and the configuration between them. Plain Language Summary: An isolated analysis of univariate extreme events may seriously underestimate the losses caused by multivariable compound extreme events (CEEs). Evolution characteristics of CEEs of temperature and precipitation in China during the past 119 years were investigated. The CEEs in China over the past 119 years experienced three stages: 1901–1950 with less CEEs, 1951–1995 with frequent cold CEEs and 1996–2019 with frequent warm CEEs. Total frequency of CEEs showed an increasing trend but each type of CEEs had an obvious interdecadal variation. The frequency of warm‐dry and cold‐wet was higher than that of warm‐wet and cold‐dry, whereas warm‐wet increased fastest among the four CEEs after 1996. Long‐term change and low frequency oscillations have the greatest impact on CEEs among long‐term change and low frequency oscillations, changes in the variability of higher frequencies and coupling changes between temperature and precipitation. Key Points: Total frequency of compound extreme events (CEEs) shows long‐term increasing trends and interdecadal oscillationWarm CEEs increased rapidly in the past three decades, while the cold CEEs were less during this periodClimate change is the dominant factor of CEEs relative to other scale factors [ABSTRACT FROM AUTHOR]

This study investigated the impacts of Tibetan Plateau vertical heating (TPVH) on the Asian summer monsoon (ASM) on the interdecadal scale since the beginning of the 20th century. The ASM, corresponding to TPVH, generally enhances on the interdecadal scale. In the upper troposphere, the upper‐level westerly and easterly jet streams shift northwards in Asia, with two meridional "southern low and northern high" wave‐like patterns dominating in East Asia and India, respectively. In the lower troposphere, the summer monsoonal airflow and convergence zone migrate northwards in Asia, and two meridional "southern high and northern low" patterns appear in East Asia and India, respectively. Thus, TPVH can strengthen the baroclinicity over northern East Asia and northern India, but weaken it over southern East Asia and southern India. Moreover, two anomalous meridional circulation cells are identified in East Asia and India, with ascending branches in their northern parts and descending branches in their southern parts. Eventually, the ASM strengthens, leading to a southern dry and northern wet pattern in East Asia and India. [ABSTRACT FROM AUTHOR]

HIF‐2α selective inhibitor showed successful efficacy in sensitive clear cell renal cell carcinoma (ccRCC) presenting higher levels of HIF‐2α compared to resistant tumors with low level of HIF‐2α (negative HIF‐2α ccRCC). Currently, negative HIF‐2α ccRCC lacks truly effective therapeutic agents to improve the outcomes. Bromodomain‐containing protein 9 (BRD9) plays a critical role in human hepatocellular carcinoma, squamous cell lung cancer, acute myeloid leukemia, and so on. However, expression and biological role of BRD9 in negative HIF‐2α ccRCC is poorly understood. Clinically, we demonstrated that expression of BRD9 in negative HIF‐2α ccRCC tissues was higher than that in positive HIF‐2α ccRCC. Moreover, high BRD9 expression was correlated with unfavorable clinicopathological features and predicted the poor overall survival of negative HIF‐2α ccRCC patients. Functionally, BRD9 knockout resulted in reduced proliferation, migration and invasion of negative HIF‐2α ccRCC cells (Caki‐2). In addition, BRD9 was related to the TIIC infiltration level in negative HIF‐2α ccRCC tissues. Mechanistically, Gene set enrichment analysis (GSEA) showed that BRD9 was closely related to Notch signaling pathway. BRD9 knockout resulted in reduced mRNA level of Hes1 and Notch1 in negative HIF‐2α ccRCC in vitro. The overexpression of NICD (Notch intracellular domain) enhanced malignant behaviors of Caki‐2 cells with BRD9 knockout. And Notch inhibition led to attenuation of cell growth and reduced migration and invasion in Caki‐2 cells. Overall, our results identified that BRD9 promotes the proliferation, migration and invasion of negative HIF‐2α ccRCC cells by targeting Notch signaling pathway and serve as a promising biomarker for negative HIF‐2α ccRCC. [ABSTRACT FROM AUTHOR]

A regional Climate‐Weather Research and Forecasting (CWRF) model with a 30‐km horizontal resolution was applied to simulate the East Asian summer monsoon (EASM) and climate in China from 1980 to 2016. As compared with observations and reanalysis data, the model can reasonably reproduce the spatial distributions of the climatological mean atmospheric circulation and water vapour transport in East Asia, as well as the seasonal advance and retreat of EASM and rain bands. The correlation coefficient between the EASM circulation index in the simulation and reanalysis is.97. The model can well represent the geographic distributions of summer mean temperature and precipitation over most of China. However, model biases still exist, in particular the skill in the Yangtze–Huaihe River basin is relatively low. The simulated climatological mean temperature and precipitation deviations from observations may be related to the model's systematic circulation biases, with a thicker lower troposphere (i.e., higher temperature between 500 and 1,000 hPa) over most of China (except for the south and southwest) and a thinner one over the coastal oceans in summertime. Compared with the reanalysis, the model overestimates the land‐ocean thermal contrast, which causes the South Asian High shifted to the north and east, as well as the subtropical high and tropical convective activity located further north and persisted longer. Consequently, more water vapour transports northward, leading to more precipitation over North China–Northeast China and less precipitation over the Yangtze and Huaihe River basin. Therefore, the enhanced land‐ocean thermal contrast may be a major factor for the stronger EASM in the model, and corresponding precipitation and temperature biases in China. This analysis provides important information for further improving model performance in EASM simulation. [ABSTRACT FROM AUTHOR]

Coronavirus disease 2019 (COVID‐19) has spread worldwide. To date, no specific drug for COVID‐19 has been developed. Thus, this randomized, open‐label, controlled clinical trial (ChiCTR2000029853) was performed in China. A total of 20 mild and common COVID‐19 patients were enrolled and randomly assigned to receive azvudine and symptomatic treatment (FNC group), or standard antiviral and symptomatic treatment (control group). The mean times of the first nucleic acid negative conversion (NANC) of ten patients in the FNC group and ten patients in the control group are 2.60 (SD 0.97; range 1–4) d and 5.60 (SD 3.06; range 2–13) d, respectively (p = 0.008). The mean times of the first NANC of four newly diagnosed subjects in the FNC group and ten subjects in the control group are 2.50 (SD 1.00; range 2–4) d and 9.80 (SD 4.73; range 3–19) d, respectively (starting from the initial treatment) (p = 0.01). No adverse events occur in the FNC group, while three adverse events occur in the control group (p = 0.06). The preliminary results show that FNC treatment in the mild and common COVID‐19 may shorten the NANC time versus standard antiviral treatment. Therefore, clinical trials of FNC treating COVID‐19 with larger sample size are warranted. [ABSTRACT FROM AUTHOR]

Fuxian Lake is one of the most important freshwater supply lakes of China; however, its water quality is affected by land degradation in its basin. This study aimed to monitor and simulate the spatiotemporal characteristics of land degradation in Fuxian Lake Basin. A comprehensive land degradation index (LDI), which integrates the indices for land use/land cover (LULC), vegetation coverage (VC), water loss and soil erosion (WLSE), wind erosion (WE) and soil moisture content (SMC), was proposed to describe the spatiotemporal characteristics of land degradation in 1990–2015; a CA‐Markov model was used to simulate and forecast the land degradation in 2020 and 2025; and the mechanisms behind land degradation were analyzed. The results showed that: (a) the degree of land degradation from 1990 to 2015 generally decreased, the most severe years of land degradation were 1990, 2000, and 2005, and the total area of degraded land remained steady at around 250 km2 from 2005 to 2015; (b) the land degradation in different years was primarily moderate, with few severe or extreme degradation; (c) the simulation showed land degradation would remain relatively stable in 2020 and 2025, and the degraded area would fluctuate slightly compared with that in 2015; and (d) the land degradation in this region was driven by both human factors and natural drivers. Therefore, some land degradation control measures should be set in advance for protecting this important supply area for freshwater. [ABSTRACT FROM AUTHOR]

The sub‐seasonal characteristics and prediction of rainfall over the South China Sea and surrounding areas during spring–summer transitional season (April–May–June) are investigated using a full set of hindcasts generated by the Dynamic Extended Range Forecast operational system version 2.0 (DERF2.0) of Beijing Climate Center, China Meteorological Administration. The onset and development of Asian summer monsoon and the seasonal migration of rain belt over East Asia can be well depicted by the model hindcasts at various leads. However, there exist considerable differences between model results and observations, and model biases depend not only on the lead time, but also on the stage of monsoon evolution. In general, forecast skill drops with increasing lead time but rises again after lead time becomes longer than 30 days, possibly associated with the effect of slowly‐varying forcing or atmospheric variability. An abrupt turning point of bias development appears around mid‐May when bias growths of wind and precipitation exhibit significant changes over the northwestern Pacific and South Asia, especially over the Bay of Bengal and the South China Sea. This abrupt bias change is reasonably captured by the first two modes of multivariate empirical orthogonal function analysis, which reveals several important features associated with the bias change. This analysis may provide useful information for further improving model performance in sub‐seasonal rainfall prediction. [ABSTRACT FROM AUTHOR]

For improving the reliability of power transmission lines, it is urgent to reduce the horizontal load and wind deviation, while replacing with drag reduced conductors can achieve it without changing the original transmission line path. On the basis of the theory of turbulence simulation, a new model of drag reduced conductor with accurate traverse section is built using finite element method software. This new model is applicable for calculating the air flow field around the conductor, for studying the effect of wind speed, attack angle and conductor section shape on the drag coefficients of both single and bundle conductors. Compared with aluminum conductor steel reinforced (ACSR) in the same diameter, drag reduced conductor has lower drag coefficient and decreases more significantly with the increase of wind speed. A new research method for the development of new conductors and the galloping of overhead conductors is presented. [ABSTRACT FROM AUTHOR]

The application of droop control in the voltage‐source converter‐based multi‐terminal direct current (VSC‐MTDC) system has been previously proposed in the literature. However, how to determine the droop coefficients to stabilise the DC voltage is still the key issue to concern and research. This study presents a novel calculation methodology for droop coefficients in the case of outage or power step disturbance on any converter station. The overall design objective is to minimise the DC voltage deviation between pre‐ and post‐disturbance, depicted with a quadratic programming model. In addition, the selection method of the optimal DC voltage signal for droop controllers is developed in both cases of communication failure and communication normal. Based on the calculated droop coefficients and selected DC voltage signal, the power coordinated control among the converter stations is implemented to stabilise the DC voltage of the post‐disturbance system quickly. Case studies are conducted on the Nordic 32 and New England system, respectively. The simulation results show that the proposed methodology for droop coefficients can significantly reduce the steady‐state DC voltage deviations without the limitation of preassigning the maximum allowable DC voltage deviation, compared to the methodologies existing in the literature. [ABSTRACT FROM AUTHOR]

Abstract: The accuracy and efficiency of the simulations in distributed hydrological models must depend on the proper estimation of flow directions and paths. Numerous studies have been carried out to delineate the drainage patterns based on gridded digital elevation models (DEMs). The triangulated irregular network (TIN) has been increasingly applied in hydrological applications due to the advantages of high storage efficiency and multi‐scale adaptive performance. Much of the previous literature focuses mainly on filling the depressions on gridded DEMs rather than treating the special cases in TIN structures, which has hampered its applications to hydrological models. This study proposes a triangulation‐based solution for the removal of flat areas and pits to enhance the simulation of flow routing on triangulated facet networks. Based on the drainage‐constrained TIN generated from only a gridded DEM by the compound point extraction (CPE) method, the inconsistent situations including flat triangles, V‐shape flat edges and sink nodes are respectively identified and rectified. The optimization algorithm is an iterative process of TIN reconstruction, in which the flat areas are generalized into their center points and the pits are rectified by embedding break lines. To verify the proposed algorithm and investigate the potential for flow routing, flow paths of steepest descent are derived by the vector‐based tracking algorithm based on the optimized TIN. A case study of TIN optimization and flow path tracking was performed on a real‐world DEM. The outcomes indicate that the proposed approach can effectively solve the problem of inconsistencies without a significant loss in accuracy of the terrain model. [ABSTRACT FROM AUTHOR]

The vehicle routing problem (VRP) is one of the most prominent problems in spatial optimization because of its broad applications in both the public and private sectors. This article presents a novel spatial parallel heuristic approach for solving large-scale VRPs with capacity constraints. A spatial partitioning strategy is devised to divide a region of interest into a set of small spatial cells to allow the use of a parallel local search with a spatial neighbor reduction strategy. An additional local search and perturbation mechanism around the border area of spatial cells is used to improve route segments across spatial cells to overcome the border effect. The results of one man-made VRP benchmark and three real-world super-large-scale VRP instances with tens of thousands of nodes verify that the presented spatial parallel heuristic approach achieves a comparable solution with much less computing time. [ABSTRACT FROM AUTHOR]

An improved variational mode decomposition (VMD) method is introduced into the mode recognition of low‐frequency oscillation of power system in this study. First, fast Fourier transform is used to determine the number of VMD components, and the approximate fitting formula of the best balancing parameter α is obtained by a large number of tests. The original signal is decomposed into several modes via improved VMD (IMVD) method. Then, Teager–Kaiser energy operator is applied on the fitting of each component to get the amplitude, frequency, and damping factor of it. By the constructed test signals, the proposed method is compared with the methods of non‐parametric VMD, empirical mode decomposition, total least‐squares estimation of signal parameters via rotational invariance techniques, and Prony on the performance of mode parameter identification. Results show that the IVMD method effectively overcomes the shortcomings of those methods mentioned above in dealing with mode mixing, noise sequence, and non‐stationary signals. Finally, the feasibility of the proposed method in extracting the low‐frequency oscillation mode parameters of power system is verified by the simulation signals of the IEEE two‐area four‐generator power system and the New England 39‐bus system. [ABSTRACT FROM AUTHOR]

The current Retinex algorithm processes the RGB channels separately for color image enhancement. However, it changes the ratios of RGB components and also causes some serious problems, such as color distortion, color noise, and the halo artifacts. To solve these issues, we propose a novel algorithm based on color space fusion. The single scale Retinex with fast mean filtering is applied to the luminance component in hue-saturation-value (HSV) color space. An enhancement adjustment factor is introduced to avoid color distortion and noise amplification. Then, the surrounding function is replaced by a small scale Gaussian filter in RGB color space to eliminate the halo artifact. A parameter is involved to keep the color natural when the reflection is estimated. Finally, the enhanced color image is constructed from the weighted averaging results of these two steps. The subjective and objective evaluations of many different backlight images captured by different cameras are implemented to verify the validity of the proposed algorithm in our experiments. The experimental results show that the proposed algorithm can not only significantly suppress the halo effect and noise amplification, but can also remove color distortion. Our proposed algorithm is superior to the multi-scale Retinex with color restoration approach and other state-of-the-art methods. © 2014 Wiley Periodicals, Inc. Col Res Appl, 41, 22-31, 2016 [ABSTRACT FROM AUTHOR]

Turn restrictions, such as 'no left turn' or 'no U-turn', are commonly encountered in real road networks. These turn restrictions must be explicitly considered in the shortest path problem and ignoring them may lead to infeasible paths. In the present study, a hybrid link-node Dijkstra's (HLND) algorithm is proposed to exactly solve the shortest path problem in road networks with turn restrictions. A new hybrid link-node labelling approach is devised by using a link-based labelling strategy at restricted nodes with turn restrictions, and a node-based labelling strategy at unrestricted nodes without turn restrictions. Computational results for several real road networks show that the proposed HLND algorithm obtains the same optimal results as the link-based Dijkstra's algorithm, while having a similar computational performance to the classical node-based Dijkstra's algorithm. [ABSTRACT FROM AUTHOR]

Malignant gliomas recur even after extensive surgery and chemo-radiotherapy. Although a relatively novel chemotherapeutic agent, temozolomide (TMZ), has demonstrated promising activity against gliomas, the effects last only a few months and drug resistance develops thereafter in many cases. It has been acknowledged that glioma cells respond to TMZ treatment by undergoing G2/M arrest, but not apoptosis. Here we demonstrate a phase-specific chemotherapy resistance due to cellular prion protein (PrPc) in human glioma cells upon TMZ treatment. TMZ-induced G2/M-arrested cultures show an upregulation of PrPc expression and are more resistant, whereas G1/S-phase cells that show decreased levels of PrPc are more sensitive to apoptosis. Furthermore, an investigation into the biological significance of PrPc association with par-4 provided the first evidence of a relationship between the endogenous levels of PrPc and the resistance of glioma cells to the apoptotic effects of TMZ. Upon TMZ treatment, PrPc exerts its antiapoptotic activity by inhibiting PKA-mediated par-4 phosphorylation that are important for par-4 activation, nuclear entry and initiation of apoptosis. In context with cell cycle-dependent responses to chemotherapy, the data from this study suggest the possibility of exploiting the PrPc-dependent pathway to improve the efficacy of TMZ-based regimen for patients with gliomas. [ABSTRACT FROM AUTHOR]