Effect of Nitrogen Addition on Selection of Germination Trait in an Alpine Meadow on the Tibet Plateau

Seed germination requirements may determine the kinds of habitat in which plants can survive. We tested the hypothesis that nitrogen (N) addition can change seed germination trait-environmental filter interactions and ultimately redistribute seed germination traits in alpine meadows. We determined the role of N addition on germination trait selection in an alpine meadow after N addition by combining a 3-year N addition experiment in an alpine meadow and laboratory germination experiments. At the species level, germination percentage, germination rate (speed) and breadth of temperature niche for germination (BTN) were positively related to survival of a species in the fertilized community. In addition, community-weighted means of germination percentage, germination rate, germination response to alternating temperature and BTN increased. However, germination response to wet-cold storage (cold stratification) and functional richness of germination traits was lower in alpine meadows with high-nitrogen addition than in those with no, low and medium N addition. Thus, N addition had a significant influence on environmental filter-germination trait interactions and generated a different set of germination traits in the alpine meadow. Further, the effect of N addition on germination trait selection by environmental filters was amount-dependent. Low and medium levels of N addition had less effect on redistribution of germination traits than the high level

Safe passing critical criterion for drawn top-coal on rear conveyor and accurate control approach for drawing opening dimension

Fully mechanized top coal caving technology has become the mainstream way of high yield and high efficiency mining in extra thick coal seams in China. The accurate control of the top-coal drawing mechanical parts is of significance to realize the automation and intellectualization of top-coal caving mining. Mastering the spatial motion law of the coal caving mechanism is the premise of accurate control. The immediate shape of the hydraulic support coal caving mechanism is jointly controlled by the support height, support attitude, extension length of the plug plate, and the relative position of the rear scraper, which has an important impact on the coal caving opening and the coal-passing height of the support. This study establishes a 3–D numerical model of four- legs top-coal caving hydraulic support (No. ZF15000/27.5/42) by using the finite element software ABAQUS. Hinge and translator connectors are used to simulate the rotation behavior and expansion-contraction behavior for hinge point and plug plate, respectively. Taking the support height (H), tail beam swing angle (α), and the plug plate extension length (l) as control variables, the spatial motion law of the hinge point between shield beam and tail beam and the end of the plug plate are modeled. The critical security equation for evaluating collision between top-coal drawing mechanical parts and rear scraper is obtained by using Levenberg-Marquardt fitting iteration method. A database for describe the calibration relationship, which contains the end coordination of plug plate, the dimension of the top-coal drawing opening, and H, α, and l, is established. The sensor type and installation position for sensing and controlling the attitude of the top-coal drawing mechanism are recommended, the approach for calculating the tail beam angle based on travel sensor is derived. Through field verification of top-coal drawing opening width, it is concluded that the relative error between measured value and calculated value meets the requirements for accurate control of top-coal drawing mechanism. The approach for controlling the top-coal drawing opening dimension is proposed, which has been successfully applied in the field

How Well Does the ERA5 Reanalysis Capture the Extreme Climate Events Over China? Part II: Extreme Temperature

The fifth-generation atmospheric reanalysis of the European Center for Medium-Range Weather Forecasts (ERA5) is the latest reanalysis product. However, the reliability of ERA5 to capture extreme temperatures is still unclear over China. Hence, based on conventional meteorological station data, a new criterion (DISO) was used to validate the ERA5 capturing extreme temperature indices derived from the Expert Team on Climate Change Detection and Indices (ETCCDI) across the six subregions of China on different timescales. The conclusions are as follows: the original daily temperatures (mean temperature, maximum temperature, and minimum temperature) can be well reproduced by ERA5 reanalysis over China. ERA5 tends to exhibit more misdetection for the duration of extreme temperature events than extreme temperature intensity and frequency. In addition, ERA5 performed best in the summer and worst in the winter, respectively. The trend of absolute indices (e.g., TXx and TNx), percentile-based indices (e.g., TX90p, TX10p, TN90p, and TN10p), and duration indices (e.g., WSDI, CSDI, and GSL) can be captured by ERA5, but ERA5 failed to capture the tendency of the diurnal temperature range (DTR) over China. Spatially, ERA5 performs well in southeastern China. However, it remains challenging to accurately recreate the extreme temperature events in the Tibetan Plateau. The elevation difference between the station and ERA5 grid point contributes to the main bias of reanalysis temperatures. The accuracy of ERA5 decreases with the increase in elevation discrepancy

How Well Does the ERA5 Reanalysis Capture the Extreme Climate Events Over China? Part I: Extreme Precipitation

ERA5 is the fifth-generation atmospheric reanalysis of the European Center for Medium-Range Weather Forecasts, with high spatiotemporal resolution and global coverage. However, the reliability of ERA5 for simulating extreme precipitation events is still unclear over China. In this study, 12 extreme precipitation indices and a comprehensive quantitative distance between indices of simulation and observation were used to evaluate ERA5 precipitation from three fundamental aspects: intensity, frequency, and duration. The geomorphological regionalization method was used to divide the subregions of China. The results showed that the ability of ERA5 to simulate annual total precipitation was better than that of daily precipitation. For the intensity indices, ERA5 performs well for simulating the PRCPTOT (annual total wet days precipitation) over China. ERA5 performs better on RX5day (max 5-days precipitation amount) and R95p (very wet days), especially in eastern China, than on RX1day (max 1-day precipitation amount) and R99p (extremely wet days). For the frequency indices, the ability of the ERA5 simulation increased as the amount of precipitation increased, except for northwestern China. However, the ability of ERA5 to simulate R50 mm (number of extreme heavy precipitation days) decreased. For the duration indices, ERA5 was better at simulating drought events than wet events in eastern China. Our results highlight the need for ERA5 to enhance the simulation of trend changes in extreme precipitation events

Andrographolide alleviates paraquat-induced acute lung injury by activating the Nrf2/HO-1 pathway

Objective(s): Paraquat (PQ), a highly effective and rapidly non-selective herbicide, mainly targets the lungs and causes acute lung injury (ALI). So far, the scarcity of effective drug candidates against PQ-induced ALI remains a big challenge. Andrographolide (Andro), with its anti-inflammatory and antioxidant activities, has been demonstrated to alleviate ALI. Nevertheless, whether Andro could alleviate the PQ-mediated ALI remains unknown. Therefore, this study will explore the effects as well as the possible mechanism of Andro against ALI caused by PQ. Materials and Methods: C57BL/6J mice were injected with 20 mg/kg PQ intraperitoneally to establish an ALI model. PQ-treated MLE-12 cells were applied to a vitro model. Nuclear factor erythroid like-2 (Nrf2) was knocked out to explore the specific effects of the Nrf2/ Heme oxygenase-1 (OH-1) pathway in the protection of Andro against ALI caused by PQ.Results: Andro significantly reduced lung damage and the ratio of Wet/Dry (W/D) weight, decreased MDA, IL-6, IL-1β, and TNF-ɑ levels, reversed the decrease of CAT and SOD levels, and inhibited apoptosis caused by PQ. Andro obviously increased the ratio of Bcl-2/Bax while reducing caspase-3 and cleaved caspase-3 levels. Furthermore, Andro dramatically elevated the antioxidant proteins Nrf2, NQO-1, and HO-1 levels compared with the PQ group. This experiment demonstrated that Andro reduced ROS and inhibited apoptosis, induced by PQ in MLE-12 cells, by inducing Nrf2/HO-1 pathway activation.Conclusion: Andro effectively ameliorates oxidant stress and apoptosis in ALI caused by PQ, possibly through inducing Nrf2/HO-1 pathway activation

Ginsenosides on stem cells fate specification—a novel perspective

Recent studies have demonstrated that stem cells have attracted much attention due to their special abilities of proliferation, differentiation and self-renewal, and are of great significance in regenerative medicine and anti-aging research. Hence, finding natural medicines that intervene the fate specification of stem cells has become a priority. Ginsenosides, the key components of natural botanical ginseng, have been extensively studied for versatile effects, such as regulating stem cells function and resisting aging. This review aims to summarize recent progression regarding the impact of ginsenosides on the behavior of adult stem cells, particularly from the perspective of proliferation, differentiation and self-renewal

Long Cycle Life TiC Anode Fabricated via High-Energy Ball Mill for Li-Ion Battery

Nano-TiC and nano-WC anodes for Li-ion battery were manufactured by high-energy ball milling. Pure titanium powder and toluene are mixed with a high-energy ball mill to prepare TiC powder. The powder is calcined at 750°C/1 h and secondary ball milled to make a negative electrode for lithium-ion battery. The phase composition and micromorphology of TiC powder are analyzed and observed, and the charge-discharge cycle performance of TiC anode material is tested. The results show that there are TiH2 and WC impurities in the product after primary ball milling. After calcination and secondary ball milling, TiH2 impurities are removed and the TiC grain size is refined, and TiC powder is obtained with a grain size of 12.5 nm. The specific discharge capacity of the TiC anode is stable during the long cycle discharge. When the current density is 1 A/g, the specific discharge capacity can still be maintained at 110 mAh/g after 3000 cycles. The results show that TiC anode materials have excellent long-cycle performance and could be used as the frame material of Si anode materials. Nano-WC powders are prepared by a ball milling method to investigate the effect of WC impurities on the performance of TiC lithium batteries. The charge and discharge capacity at 0.5 A/g current density is similar to that of TiC anode. After 2000 cycles, the discharge-specific capacity is about 100 mA/g, which is slightly lower than TiC, and the final capacity is maintained at 230 mA/g, but its low discharge capacity affects the performance of the TiC battery after a long ball milling. The results show that the performance of the TiC anode after the first 50 h of ball milling is poor. The main reason is the agglomeration of TiC nanoparticles

The Gelo’s Wisdom on Water Ecology from the Ecological Concept of “Shield and Sustain”

The Gelo’s living environment and worship of nature breeds its ecological concept of “shield and sustain”, self-consciousness of water ecology, water protection behavior custom and rules, and superior hydro-ecology wisdom based adequate protection and utilization of water resources. With today’s commitment to holding and carrying forward Gelos’ traditional wisdom of water protection, it is recommended to popularize and apply the modern water conservancy science and technology and the Gelos’ traditional wisdom of water protection in a parallel or integrated way, which is of far-reaching significance to boosting the rural revitalization of the Gelo ethnic group and even promoting the domestic construction of modern ecological civilization

A Comparative Study of Frequent Pattern Mining with Trajectory Data

Sequential pattern mining (SPM) is a major class of data mining topics with a wide range of applications. The continuity and uncertain nature of trajectory data make it distinctively different from typical transactional data, which requires additional data transformation to prepare for SPM. However, little research focuses on comparing the performance of SPM algorithms and their applications in the context of trajectory data. This study selected some representative sequential pattern mining algorithms and evaluated them with various parameters to understand the effect of the involved parameters on their performances. We studied the resultant sequential patterns, runtime, and RAM consumption in the context of the taxi trajectory dataset, the T-drive dataset. It was demonstrated in this work that a method to discretize trajectory data and different SPM algorithms were performed on trajectory databases. The results were visualized on actual Beijing road maps, reflecting traffic congestion conditions. Results demonstrated contiguous constraint-based algorithms could provide a concise representation of output sequences and functions at low min_sup with balanced RAM consumption and execution time. This study can be used as a guide for academics and professionals when determining the most suitable SPM algorithm for applications that involve trajectory data