30 results on '"Li, Rumeng"'
Search Results
2. Spatiotemporal changes in snow depth and the influence factors in China from 1979 to 2019
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Li, Rumeng, Xia, Haoming, Zhao, Xiaoyang, Bian, Xiqing, Guo, Yan, and Qin, Yaochen
- Published
- 2023
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3. Loss of RSR1 function increases the abscisic acid content and improves rice quality performance at high temperature
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Sun, Xiaosong, Bian, Xinyue, Wang, Jingdong, Chen, Si, Yang, Rui, Li, Rumeng, Xia, Lexiong, Chen, Dinghao, and Fan, Xiaolei
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- 2024
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4. Mapping evergreen forests using new phenology index, time series Sentinel-1/2 and Google Earth Engine
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Li, Rumeng, Xia, Haoming, Zhao, Xiaoyang, and Guo, Yan
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- 2023
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5. Extreme large-scale atmospheric circulation associated with the “21·7” Henan flood
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Xu, Jun, Li, Rumeng, Zhang, Qinghong, Chen, Yun, Liang, Xudong, and Gu, Xiujie
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- 2022
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6. Monitoring the spatiotemporal dynamics of surface water body of the Xiaolangdi Reservoir using Landsat-5/7/8 imagery and Google Earth Engine
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Wang Ruimeng, Pan Li, Niu Wenhui, Li Rumeng, Zhao Xiaoyang, Bian Xiqing, Yu Chong, Xia Haoming, and Chen Taizheng
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landsat imagery ,google earth engine ,water body extraction ,spatiotemporal change ,xiaolangdi reservoir ,Geology ,QE1-996.5 - Abstract
Xiaolangdi Reservoir is a key control project to control the water and sediment in the lower Yellow River, and a timely and accurate grasp of the reservoir’s water storage status is essential for the function of the reservoir. This study used all available Landsat images (789 scenes) and adopted the modified normalized difference water index, enhanced vegetation index, and normalized difference vegetation index to map the surface water from 1999 to 2019 in Google Earth Engine (GEE) cloud platform. The spatiotemporal characteristics of the surface water body area changes in the Xiaolangdi Reservoir in the past 21 years are analyzed from the water body type division, area change, type conversion, and the driving force of the Xiaolangdi water body area changes was analyzed. The results showed that (1) the overall accuracy of the water body extraction method was 98.86%, and the kappa coefficient was 0.96; (2) the maximum water body area of the Xiaolangdi Reservoir varies greatly between inter-annual and intra-annual, and seasonal water body and permanent water body have uneven spatiotemporal distribution; (3) in the conversion of water body types, the increased seasonal water body area of the Xiaolangdi Reservoir from 1999 to 2019 was mainly formed by the conversion of permanent water body, and the reduced permanent water body area was mainly caused by non-water conversion; and (4) the change of the water body area of the Xiaolangdi Reservoir has a weak negative correlation with natural factors such as precipitation and temperature, and population. It is positively correlated with seven indicators such as runoff and regional gross domestic product (GDP). The findings of the research will provide necessary data support for the management and planning of soil and water resources in the Xiaolangdi Reservoir.
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- 2021
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7. Chitosan/biological benzoxazine composites: Effect of benzoxazine structure on the properties of composites
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Yang, Yunhe, Li, Rumeng, Liu, Xiaoyun, Ma, Qi, Zhang, Yitong, and Zhuang, Qixin
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- 2021
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8. Surface grafting modification of titanium dioxide by silane coupler KH570 and its influences on the application of blue light curing ink
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Wang, Lili, Li, Rumeng, Wang, Chenglong, Hao, Bairan, and Shao, Jianzhong
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- 2019
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9. Identification and Characterization of a Nerol Synthase in Fungi.
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Li, Rumeng, Yao, Bo, and Zeng, Haichun
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- 2024
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10. Recombinant baculovirus vaccine expressing hemagglutinin of H7N9 avian influenza virus confers full protection against lethal highly pathogenic H7N9 virus infection in chickens
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Hu, Jiao, Liang, Yanyan, Hu, Zenglei, Wang, Xiaoquan, Gu, Min, Li, Rumeng, Ma, Chunxi, Liu, Xiaowen, Hu, Shunlin, Chen, Sujuan, Peng, Daxin, Jiao, Xinan, and Liu, Xiufan
- Published
- 2019
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11. Mesoscale Factors Contributing to the Extreme Rainstorm on 20 July 2021 in Zhengzhou, China, as Revealed by Rapid Update 4DVar Analysis.
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Sun, Juanzhen, Li, Rumeng, Zhang, Qinghong, Trier, Stanley B., Ying, Zhuming, and Xu, Jun
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RAINSTORMS , *VERTICAL wind shear , *JETS (Fluid dynamics) , *RAINFALL , *THUNDERSTORMS - Abstract
The purpose of this study is to diagnose mesoscale factors responsible for the formation and development of an extreme rainstorm that occurred on 20 July 2021 in Zhengzhou, China. The rainstorm produced 201.9 mm of rainfall in 1 h, breaking the record of mainland China for 1-h rainfall accumulation in the past 73 years. Using 2-km continuously cycled analyses with 6-min updates that were produced by assimilating observations from radar and dense surface networks with a four-dimensional variational (4DVar) data assimilation system, we illustrate that the modification of environmental easterlies by three mesoscale disturbances played a critical role in the development of the rainstorm. Among the three systems, a mesobeta-scale low pressure system (mesolow) that developed from an inverted trough southwest of Zhengzhou was key to the formation and intensification of the rainstorm. We show that the rainstorm formed via sequential merging of three convective cells, which initiated along the convergence bands in the mesolow. Further, we present evidence to suggest that the mesolow and two terrain-influenced flows near the Taihang Mountains north of Zhengzhou, including a barrier jet and a downslope flow, contributed to the local intensification of the rainstorm and the intense 1-h rainfall. The three mesoscale features coexisted near Zhengzhou in the several hours before the extreme 1-h rainfall and enhanced local wind convergence and moisture transport synergistically. Our analysis also indicated that the strong midlevel south/southwesterly winds from the mesolow along with the gravity-current-modified low-level northeasterly barrier jet enhanced the vertical wind shear, which provided favorable local environment supporting the severe rainstorm. [ABSTRACT FROM AUTHOR]
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- 2023
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12. A Review of Research on the Record-Breaking Precipitation Event in Henan Province, China, July 2021.
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Zhang, Qinghong, Li, Rumeng, Sun, Juanzhen, Lu, Feng, Xu, Jun, and Zhang, Fan
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LITERATURE reviews , *GLOBAL warming , *METEOROLOGICAL stations , *METEOROLOGICAL research , *DENSITY currents , *RAINSTORMS , *TROPICAL cyclones - Abstract
A record-breaking precipitation event, with a maximum 24-h (1-h) precipitation of 624 mm (201.9 mm) observed at Zhengzhou Weather Station, occurred in Henan Province, China, in July 2021. However, all global operational forecast models failed to predict the intensity and location of maximum precipitation for this event. The unexpected heavy rainfall caused 398 deaths and 120.06 billion RMB of economic losses. The high-societal-impact of this event has drawn much attention from the research community. This article provides a research review of the event from the perspectives of observations, analysis, dynamics, predictability, and the connection with climate warming and urbanization. Global reanalysis data show that there was an anomalous large-scale circulation pattern that resulted in abundant moisture supply to the region of interest. Three mesoscale systems (a mesoscale low pressure system, a barrier jet, and downslope gravity current) were found by recent high-resolution model simulation and data assimilation studies to have contributed to the local intensification of the rainstorm. Furthermore, observational analysis has suggested that an abrupt increase in graupel through microphysical processes after the sequential merging of three convective cells contributed to the record-breaking precipitation. Although these findings have aided in our understanding of the extreme rainfall event, preliminary analysis indicated that the practical predictability of the extreme rainfall for this event was rather low. The contrary influences of climate warming and urbanization on precipitation extremes as revealed by two studies could add further challenges to the predictability. We conclude that data sharing and collaboration between meteorological and hydrological researchers will be crucial in future research on high-impact weather events. [ABSTRACT FROM AUTHOR]
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- 2023
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13. Mixture from carboxymethyl tamarind gum and carboxymethyl starch on double-sided printing of georgette fabric
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Wang, Lili, Li, Rumeng, Wang, Chenglong, Shao, Jianzhong, Wu, Minghua, and Wang, Wei
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- 2017
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14. Mapping tea plantation area using phenology algorithm, time-series Sentinel-2 and Landsat images.
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Xia, Haoming, Bian, Xiqing, Pan, Li, and Li, Rumeng
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TEA plantations ,LANDSAT satellites ,PHENOLOGY ,PLANT phenology ,TEA extracts ,PLANT growth ,SHRUBS - Abstract
Tea plants are evergreen broad-leaved perennial shrubs, and their spectral characteristics are very similar to those of other evergreen vegetation, making it difficult to distinguish them. Currently, the most commonly used method of tea plantation extraction is machine learning, which classifies tea plantation through various feature combinations and algorithms. The disadvantage of these methods is that they require a large number of local training samples, making it challenging to produce an accurate model applicable to a large region. Furthermore, complex feature combinations and indicators may result in over-fitting, reducing the accuracy of the results. Therefore, it is necessary to develop a new algorithm suitable for tea plantation extraction in extensive regions. This paper uses Shihe District, Henan Province, China as a case in 2019, combined with Landsat-7/8 and Sentinel-2A/B images, and develops a new phenological-based algorithm to extract the tea plantation area. Firstly, we generated an evergreen vegetation map. Secondly, based on high-quality time series curves, the tea plant growth period was divided into seven parts to extract phenological indicators for classification. Finally, the tea plantation in the study area was extracted on a per-pixel basis. The overall accuracy of the algorithm is 87.59%, and the Kappa coefficient is 0.80. This study demonstrates the potential of the phenology-algorithms in extracting tea plantation areas and provides an advanced scheme and scientific basis for extracting tea plantation in other years, and also offers a reference for identifying tea plantation in other regions. Additionally, this paper generated a map of classified phenological indicators to provide guidance for monitoring tea plants growth. [ABSTRACT FROM AUTHOR]
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- 2023
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15. Comparative Analyses of Grain Quality in Response to High Temperature during the Grain-Filling Stage between Wx a and Wx b under Indica and Japonica Backgrounds.
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Fan, Xiaolei, Sun, Xiaosong, Yang, Rui, Chen, Si, Li, Rumeng, Bian, Xinyue, Xia, Lexiong, and Zhang, Changquan
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RICE ,HIGH temperatures ,GRAIN ,RICE quality ,WESTERN immunoblotting ,AMYLOSE ,COMPARATIVE studies - Abstract
Amylose content controlled by Wx determines rice grain quality, which is easily affected by high temperature. Wx
a and Wxb are the two typical Wx alleles in rice, however, their effects on quality formation in response to high temperature under the backgrounds of indica rice and japonica rice have not been systematically compared. In this study, the near-isogenic lines (NILs) of Wxa and Wxb with japonica rice 2661 and indica rice 3611 backgrounds were treated by high temperature during the grain-filling stages. High temperature accelerated the grain ripening process, decreased the thousand-kernel weight, and increased the chalkiness degree of all rice samples. However, these traits of Wx NILs with 3611 background were more susceptible to high temperature than those with 2661 background. Furthermore, high-temperature treatment decreased the amylose contents (AC) and starch viscosities but increased the gelatinization temperature of all the Wx NILs. The 3611-Wxa was atypical Wxa -type rice, whose AC was more sensitive to high temperature. The AC result was consistent with quantitative analysis of GBSSI by Western blot. In addition, the effects of Wx genotype and genetic background on rice physicochemical quality (such as the gel consistencies, starch crystallinity, and the morphological structure of starch grains) in response to high temperature were systematically analyzed. These results have important guiding significance for rice-quality improvement under high-temperature climate. [ABSTRACT FROM AUTHOR]- Published
- 2023
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16. Model Predictability of Hail Precipitation with a Moderate Hailstorm Case. Part I: Impact of Improved Initial Conditions by Assimilating High-Density Observations.
- Author
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Li, Rumeng, Sun, Juanzhen, Zhang, Qinghong, and Jensen, Anders A.
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HAILSTORMS , *ATMOSPHERIC boundary layer , *VERTICAL wind shear , *METEOROLOGICAL research , *WEATHER forecasting , *NUMERICAL weather forecasting - Abstract
Hailstones have large damage potential; however, their explicit prediction remains quite challenging. The uncertainty in a model's initial condition and microphysics are two of the significant contributors to the challenge. This two-part study aims to investigate the impacts of improved initial condition and microphysics on hail prediction for a moderate hailstorm that occurred in Beijing on 10 June 2016. In the first part, the role of initial conditions on hail prediction is explored by assimilating high-density observations into a numerical model with a recently developed explicit hail microphysics scheme. High-resolution and high-frequency observations from radar and surface networks are assimilated using the Weather Research and Forecasting (WRF) Model's three-dimensional variational data assimilation (3DVAR) system. The role of the initial conditions in improving explicit hail prediction with two different planetary boundary layer (PBL) schemes, the Yonsei University (YSU) scheme and the Mellor–Yamada–Janjić (MYJ) scheme, is then examined. Results indicate that the data assimilation significantly improves the hail size and location prediction for both PBL schemes by reducing errors in surface wind, temperature, and moisture fields. It is also shown that the improved analyses of low-level and midlevel vertical wind shear, resulting mainly from radar data assimilation, are pivotal to the improvement of hailstorm prediction with the YSU scheme, while the improved analysis of thermodynamic field resulting from the assimilation of both radar and surface data plays a more important role with the MYJ scheme. The results of this work shed light on the influence of data assimilation and provide insights on explicit hail predictability with respect to model initial conditions. [ABSTRACT FROM AUTHOR]
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- 2022
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17. Smartphone pressure data: quality control and impact on atmospheric analysis.
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Li, Rumeng, Zhang, Qinghong, Sun, Juanzhen, Chen, Yun, Ding, Lili, and Wang, Tian
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QUALITY control , *SMARTPHONES , *URBAN density , *DATA quality , *CELL phone users , *ATMOSPHERIC sciences - Abstract
Smartphones are increasingly being equipped with atmospheric measurement sensors providing huge auxiliary resources for global observations. Although China has the highest number of cell phone users, there is little research on whether these measurements provide useful information for atmospheric research. Here, for the first time, we present the global spatial and temporal variation in smartphone pressure measurements collected in 2016 from the Moji Weather app. The data have an irregular spatiotemporal distribution with a high density in urban areas, a maximum in summer and two daily peaks corresponding to rush hours. With the dense dataset, we have developed a new bias-correction method based on a machine-learning approach without requiring users' personal information, which is shown to reduce the bias of pressure observation substantially. The potential application of the high-density smartphone data in cities is illustrated by a case study of a hailstorm that occurred in Beijing in which high-resolution gridded pressure analysis is produced. It is shown that the dense smartphone pressure analysis during the storm can provide detailed information about fine-scale convective structure and decrease errors from an analysis based on surface meteorological-station measurements. This study demonstrates the potential value of smartphone data and suggests some future research needs for their use in atmospheric science. [ABSTRACT FROM AUTHOR]
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- 2021
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18. Role of RASA1 in cancer: A review and update.
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Zhang, Yanhua, Li, Yue, Wang, Quanyue, Su, Bo, Xu, Hui, Sun, Yang, Sun, Pei, Li, Rumeng, Peng, Xiaochun, and Cai, Jun
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- 2020
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19. IL-37 expression is decreased in patients with hyperhomocysteinemia and protects cells from inflammatory injury by homocysteine.
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Wang, Sen, Huang, Zhen, Li, Wenrui, He, Suhui, Wu, Hongmei, Zhu, Jiandong, Li, Rumeng, Liang, Zhuangyan, and Chen, Zhangquan
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INTERLEUKIN-37 ,HUMAN body ,BLOOD cells ,LACTATE dehydrogenase ,PROTEIN expression - Abstract
As a novel anti-inflammatory cytokine of the interleukin (IL)-1 family, IL-37 protects the human body from diseases characterized by excessive inflammation. The pathologic process of hyperhomocysteinemia (hHcy) is accompanied by persistent inflammation. However, little is known regarding the role of IL-37 in hHcy. In the present study, the levels of cytokines including IL-37, IL-1β, IL-6 and tumor necrosis factor-α in the supernatant were detected by ELISA. mRNA and protein expression were detected by Reverse transcription-quantitative PCR and western blotting, respectively. LDH level was determined by ELISA and the cell viability was detected through CCK-8 kit. In the present study, mean serum IL-37 levels of patients with hHcy were 32.3% lower than those of controls (P<0.01). In peripheral blood mononuclear cells (PBMCs) from patients with hHcy, mean IL-37 mRNA expression was 73.5% lower (P<0.01) and IL-37 protein expression was 77.7% lower compared with that of healthy controls (P<0.01). Furthermore, the results demonstrated that exogenous homocysteine (Hcy) stimulation markedly downregulated the mRNA and protein expression levels of IL-37 in PBMCs in vitro. In 293T cells, overexpression of IL-37 restored the cell viability impaired by Hcy, and reduced the release of lactate dehydrogenase and the proinflammatory cytokines IL-1β, IL-6 and tumor necrosis factor-α. In conclusion, IL-37 was downregulated by Hcy in vivo and in vitro, and IL-37 exhibited a protective role against cell injury induced by Hcy. [ABSTRACT FROM AUTHOR]
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- 2020
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20. New thickener based on s-triazine di-sulfanilic xanthan for reactive printing of silk fabric with double-sided patterns.
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Li, Rumeng, Hao, Bairan, Wu, Minghua, Wang, Lili, and Wang, Wei
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SILK screen printing ,XANTHAN gum ,TRIAZINES ,SILK ,SODIUM alginate ,FOURIER transforms ,TEXTILES - Abstract
In order to achieve good double-sided printing patterns on silk fabric, a new thickener s-triazine di-sulfanilic xanthan (TDG) was prepared by chemical modification of xanthan gum (XG) using alkali and monochlorotriazine di-sulfanilic acid (TS) as modifiers. The structure of TDG was characterized by Fourier transform infrared spectrophotometry. Rheological behaviors were investigated by steady-shear, dynamic strain sweep and step-shear tests. The results indicated that TDG showed better flowability and smaller structural viscosity than XG. TDG always exhibited the viscous effects under external forces while XG experienced the transition from elasticity to viscosity. Used as a thickener in reactive printing of silk fabric in screen printing, TDG obtained much higher screenability, color yield, penetration and outline sharpness than XG. The double-sided printing qualities of TDG even surpassed those of sodium alginate, implying great potentiality of TDG as a good thickener for double-sided patterns. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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21. Tripterygium wilfordii Glycosides Upregulate the New Anti-Inflammatory Cytokine IL-37 through ERK1/2 and p38 MAPK Signal Pathways.
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Wang, Sen, Li, Rumeng, He, Suhui, He, Lingge, Zhao, Hang, Deng, Xiaohong, and Chen, Zhangquan
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ANTI-inflammatory agents , *AUTOIMMUNE diseases , *CELLULAR signal transduction , *CYTOKINES , *HERBAL medicine , *INTERLEUKINS , *CHINESE medicine , *SIGNAL peptides , *PHARMACOKINETICS - Abstract
As a Chinese traditional patent medicine, Tripterygium wilfordii glycosides (TWG) have been approved by the China State Food and Drug Administration (Z32021007) for autoimmune and inflammatory diseases. Application of TWG leads to significant decrease of the inflammatory cytokines, such as IL-6, IL-1β, and TNF-α. However, little is known whether TWG could regulate the anti-inflammatory cytokines and what the mechanism is. Here, we found that TWG could induce the upregulation of IL-37 which is a new anti-inflammatory cytokine. Furthermore, the inhibitors of ERK1/2 and/or p38 MAPK pathways suppressed IL-37 expression induced by TWG, indicating that the two pathways took part in this process. In conclusion, TWG could upregulate the anti-inflammatory cytokine IL-37 and ERK1/2 and p38 MAPK signal pathways were involved in the upregulation of IL-37 induced by TWG. The results showed that TWG had a potent activity on promoting the expression of IL-37, a new anti-inflammatory cytokine, which help further understanding the anti-inflammatory mechanism for the clinical application of TWG in therapy of diseases. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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22. Rheological behaviors of carboxymethyl tamarind gum as thickener on georgette printing with disperse dyes.
- Author
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Wang, Lili, Li, Rumeng, Shao, Jianzhong, and Wang, Zhao
- Abstract
ABSTRACT The printing performances on georgette fabric with disperse dyes are closely related to the rheological behaviors of thickener used in the printing paste. Compared with sodium alginate (SA), rheological behaviors of carboxymethyl tamarind gum (CTG) were investigated by steady shear, oscillatory and transient tests. Results showed that CTG and SA exhibited typical pseudoplastic characteristics, more viscous behaviors under lower frequency and high viscosity recoverability. Flow behaviors were well predicted by Cross model at low shear rates and power-law model at high shear rates. Viscoelastic behaviors were well depicted by Friedrich-Braun model. However, CTG had quicker shear-thinning features and stronger elasticity than SA. In the disperse printing of georgette fabric, CTG had better screenability, higher color yield, excellent double-sided printings, levelness, hand, color fastness, and outline sharpness instead of SA. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45000. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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23. Web GIS for Sustainable Education: Towards Natural Disaster Education for High School Students.
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Li, Jiaqi, Xia, Haoming, Qin, Yaochen, Fu, Pinde, Guo, Xuan, Li, Rumeng, and Zhao, Xiaoyang
- Abstract
The rapid development of the web geographic information system (Web GIS) has promoted new vitality in high school geography education, relieved the stress of geography teachers caused by software and technical problems, and made it possible for teachers to devote more energy to geography teaching and research activities. Natural disaster education is not only an important part of the geography curriculum, but also an indispensable aspect of education for sustainable development (ESD) for high school students. The application of Web GIS in the dynamic monitoring, forecast, and early warning of natural disasters is becoming more experienced. Therefore, the application of Web GIS in natural disaster education is quite feasible. How to build a bridge between them is the purpose of this paper. Thus, the paper selects ArcGIS Online, which is not limited by time and space, and analyzes several functions that apply it to geography teaching. These include smart mapping, story maps, 3D web maps, and mobile GIS. Meanwhile, it analyzes the knowledge structure of "natural disasters" in Chinese geography textbooks to guide the subsequent case design. Then, the Web GIS inquiry-based teaching case is formed based on "7.20 Zhengzhou Torrential Rain". It contains knowledge about natural disasters and designs from many aspects, such as the causes, manifestations, and prevention and control of disasters. The discussion identifies a range of specific educational benefits of applying Web GIS to natural disaster education for teachers and schools. Ultimately, it can provide some reference values for geography teachers and other developers to explore curriculum resources and create quality educational models. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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24. Mapping the Northern Limit of Double Cropping Using a Phenology-Based Algorithm and Google Earth Engine.
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Guo, Yan, Xia, Haoming, Pan, Li, Zhao, Xiaoyang, and Li, Rumeng
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DOUBLE cropping ,MODIS (Spectroradiometer) ,FARM management ,CLIMATE change ,AGRICULTURAL policy ,PLANT phenology - Abstract
Double cropping is an important cropping system in China, with more than half of China's cropland adopting the practice. Under the background of global climate change, agricultural policies, and changing farming practices, double-cropping area has changed substantially. However, the spatial-temporal dynamics of double cropping is poorly understood. A better understanding of these dynamics is necessary for the northern limit of double cropping (NLDC) to ensure food security in China and the world and to achieve zero hunger, the second Sustainable Development Goal (SDG). Here, we developed a phenology-based algorithm to identify double-cropping fields by analyzing time-series Moderate Resolution Imaging Spectroradiometer (MODIS) images during the period 2000–2020 using the Google Earth Engine (GEE) platform. We then extracted the NLDC using the kernel density of pixels with double cropping and analyzed the spatial-temporal dynamics of NLDC using the Fishnet method. We found that our algorithm accurately extracted double-cropping fields, with overall, user, and producer accuracies and Kappa coefficients of 95.97%, 96.58%, 92.21%, and 0.91, respectively. Over the past 20 years, the NLDC generally trended southward (the largest movement was 66.60 km) and eastward (the largest movement was 109.52 km). Our findings provide the scientific basis for further development and planning of agricultural production in China. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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25. Drought Monitoring over Yellow River Basin from 2003–2019 Using Reconstructed MODIS Land Surface Temperature in Google Earth Engine.
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Zhao, Xiaoyang, Xia, Haoming, Pan, Li, Song, Hongquan, Niu, Wenhui, Wang, Ruimeng, Li, Rumeng, Bian, Xiqing, Guo, Yan, and Qin, Yaochen
- Subjects
DROUGHT management ,EARTH temperature ,LAND surface temperature ,DROUGHTS ,WATERSHEDS ,NORMALIZED difference vegetation index ,ENVIRONMENTAL disasters - Abstract
Drought is one of the most complex and least-understood environmental disasters that can trigger environmental, societal, and economic problems. To accurately assess the drought conditions in the Yellow River Basin, this study reconstructed the Land Surface Temperature (LST) using the Annual Temperature Cycle (ATC) model and the Normalized Difference Vegetation Index (NDVI). The Temperature Condition Index (TCI), Vegetation Condition Index (VCI), Vegetation Health Index (VHI), and Temperature-Vegetation Drought Index (TVDI), which are four typical remote sensing drought indices, were calculated. Then, the air temperature, precipitation, and soil moisture data were used to evaluate the applicability of each drought index to different land types. Finally, this study characterized the spatial and temporal patterns of drought in the Yellow River Basin from 2003 to 2019. The results show that: (1) Using the LST reconstructed by the ATC model to calculate the drought index can effectively improve the accuracy of drought monitoring. In most areas, the reconstructed TCI, VHI, and TVDI are more reliable for monitoring drought conditions than the unreconstructed VCI. (2) The four drought indices (TCI, VCI, VH, TVDI) represent the same temporal and spatial patterns throughout the study area. However, in some small areas, the temporal and spatial patterns represented by different drought indices are different. (3) In the Yellow River Basin, the drought level is highest in the northwest and lowest in the southwest and southeast. The dry conditions in the Yellow River Basin were stable from 2003 to 2019. The results in this paper provide a basis for better understanding and evaluating the drought conditions in the Yellow River Basin and can guide water resources management, agricultural production, and ecological protection of this area. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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26. Development of a New Phenology Algorithm for Fine Mapping of Cropping Intensity in Complex Planting Areas Using Sentinel-2 and Google Earth Engine.
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Guo, Yan, Xia, Haoming, Pan, Li, Zhao, Xiaoyang, Li, Rumeng, Bian, Xiqing, Wang, Ruimeng, and Yu, Chong
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AGRICULTURAL remote sensing ,NORMALIZED difference vegetation index ,STANDARD deviations ,DOUBLE cropping ,PHENOLOGY - Abstract
Cropping intensity is a key indicator for evaluating grain production and intensive use of cropland. Timely and accurately monitoring of cropping intensity is of great significance for ensuring national food security and improving the level of national land management. In this study, we used all Sentinel-2 images on the Google Earth Engine cloud platform, and constructed an improved peak point detection method to extract the cropping intensity of a heterogeneous planting area combined with crop phenology. The crop growth cycle profiles were extracted from the multi-temporal normalized difference vegetation index (NDVI) and land surface water index (LSWI) datasets. Results show that by 2020, the area of single cropping, double cropping, and triple cropping in the Henan Province are 52,236.9 km
2 , 74,334.1 km2 , and 1927.1 km2 , respectively; the corresponding producer accuracies are 86.12%, 93.72%, and 91.41%, respectively; the corresponding user accuracies are 88.99%, 92.29%, and 71.26%, respectively. The overall accuracy is 90.95%, and the Kappa coefficient is 0.81. Using the sown area in the statistical yearbook data of cities in the Henan Province to verify the extraction results of this paper, the R2 is 0.9717, and the root mean square error is 1715.9 km2 . This study shows that using all the Sentinel-2 data, the phenology algorithm, and cloud computing technology has great potential in producing a high spatio-temporal resolution dataset for crop remote sensing monitoring and agricultural policymaking in complex planting areas. [ABSTRACT FROM AUTHOR]- Published
- 2021
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27. H7N9 influenza virus-like particle based on BEVS protects chickens from lethal challenge with highly pathogenic H7N9 avian influenza virus.
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Li, Jun, Li, Rumeng, Zhang, Qi, Peng, Peipei, Wang, Xiaoquan, Gu, Min, Hu, Zenglei, Jiao, Xinan, Peng, Daxin, Hu, Jiao, and Liu, Xiufan
- Subjects
- *
INFLUENZA A virus, H7N9 subtype , *CHICKEN diseases , *H7N9 Influenza , *NEWCASTLE disease virus , *VIRUS-like particles , *VIRAL shedding , *CHICKENS - Abstract
• The H7N9 VLPs based on BEVS was successfully generated. • H7N9 VLPs confers 100 % protection against lethal H7N9 virus challenge in birds. • H7N9 VLPs significantly limits viral shedding. • H7N9 VLPs confers complete inhibition of virus replication in birds. • H7N9 VLPs dramatically alleviates acute lung injury of the birds challenged by H7N9. H7N9 avian influenza virus poses a dual threat to both poultry industry and public health. Therefore, it is highly urgent to develop an effective vaccine to reduce its pandemic potential. Virus-like particles (VLP) represent an effective approach for pandemic vaccine development. In this study, a recombinant baculovirus co-expressing the HA, NA and M1 genes of the H7N9 virus was constructed for generation of H7N9 VLP. Single immunization of chickens with 15 μg of the VLP or the commercial whole virus inactivated vaccine stimulates high hemagglutination inhibition, virus neutralizing and HA-specific IgY antibodies. Moreover, the antiserum had a good cross-reactivity with H7N9 field strains isolated in different years. Within 14 days after a lethal challenge with highly pathogenic (HP) H7N9 virus, no clinical symptoms and death were observed in the vaccinated chickens, and no virus was recovered from the organs. Compared to the non-vaccinated chickens, H7N9 VLP significantly reduced the proportion of animals shedding virus. Only 30 % of the VLP-vaccinated birds shed virus, whereas virus shedding was detected in 50 % of the chickens immunized with the commercial vaccine. Moreover, both vaccines dramatically alleviated pulmonary lesions caused by HP H7N9 virus, with a greater degree observed for the VLP. Altogether, our results indicated that the H7N9 VLP vaccine candidate confers a complete clinical protection against a lethal challenge with HP H7N9 virus, significantly inhibits virus shedding and abolishes viral replication in chickens. The VLP generated in this study represents a promising alternative strategy for the development of novel H7N9 avian influenza vaccines for chickens. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
28. Research on Large-Scale Urban Shrinkage and Expansion in the Yellow River Affected Area Using Night Light Data.
- Author
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Niu, Wenhui, Xia, Haoming, Wang, Ruimeng, Pan, Li, Meng, Qingmin, Qin, Yaochen, Li, Rumeng, Zhao, Xiaoyang, Bian, Xiqing, and Zhao, Wei
- Subjects
URBAN planning ,URBAN decline ,URBAN research ,SMALL cities ,RIVERS - Abstract
As the land use issue, caused by urban shrinkage in China, is becoming more and more prominent, research on urban shrinkage and expansion has become particularly challenging and urgent. Based on the points of interest (POI) data, this paper redefines the scope, quantity, and area of natural cities by using threshold methods, which accurately identify the shrinkage and expansion of cities in the Yellow River affected area using night light data in 2013 and 2018. The results show that: (1) there are 3130 natural cities (48,118.75 km
2 ) in the Yellow River affected area, including 604 shrinking cities (8407.50 km2 ) and 2165 expanding cities (32,972.75 km2 ). (2) The spatial distributions of shrinking and expanding cities are quite different. The shrinking cities are mainly located in the upper Yellow River affected area, except for the administrative cities of Lanzhou and Yinchuan; the expanding cities are mainly distributed in the middle and lower Yellow River affected area, and the administrative cities of Lanzhou and Yinchuan. (3) Shrinking and expanding cities are typically smaller cities. The research results provide a quick data supported approach for regional urban planning and land use management, for when regional and central governments formulate the outlines of urban development monitoring and regional planning. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
29. Dynamic Monitoring of Surface Water Area during 1989–2019 in the Hetao Plain Using Landsat Data in Google Earth Engine.
- Author
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Wang, Ruimeng, Xia, Haoming, Qin, Yaochen, Niu, Wenhui, Pan, Li, Li, Rumeng, Zhao, Xiaoyang, Bian, Xiqing, and Fu, Pinde
- Subjects
WATER ,AGRICULTURAL water supply ,NORMALIZED difference vegetation index ,SURFACE area ,WATER supply ,CLOUD computing - Abstract
The spatio-temporal change of the surface water is very important to agricultural, economic, and social development in the Hetao Plain, as well as the structure and function of the ecosystem. To understand the long-term changes of the surface water area in the Hetao Plain, we used all available Landsat images (7534 scenes) and adopted the modified Normalized Difference Water Index (mNDWI), Enhanced Vegetation Index (EVI), and Normalized Difference Vegetation Index (NDVI) to map the open-surface water from 1989 to 2019 in the Google Earth Engine (GEE) cloud platform. We further analyzed precipitation, temperature, and irrigated area, revealing the impact of climate change and human activities on long-term surface water changes. The results show the following. (1) In the last 31 years, the maximum, seasonal, and annual average water body area values in the Hetao Plain have exhibited a downward trend. Meanwhile, the number of maximum, seasonal, and permanent water bodies displayed a significant upward trend. (2) The variation of the surface water area in the Hetao Plain is mainly affected by the maximum water body area, while the variation of the water body number is mainly affected by the number of minimum water bodies. (3) Precipitation has statistically significant positive effects on the water body area and water body number, which has statistically significant negative effects with temperature and irrigation. The findings of this study can be used to help the policy-makers and farmers understand changing water resources and its driving mechanism and provide a reference for water resources management, agricultural irrigation, and ecological protection. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
30. Baculovirus-derived influenza virus-like particle confers complete protection against lethal H7N9 avian influenza virus challenge in chickens and mice.
- Author
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Hu, Jiao, Zhang, Qi, Peng, Peipei, Li, Rumeng, Li, Jun, Wang, Xiaoquan, Gu, Min, Hu, Zenglei, Hu, Shunlin, Liu, Xiaowen, Mei, Mei, Jiao, Xinan, Peng, Daxin, and Liu, Xiufan
- Subjects
- *
INFLUENZA A virus, H7N9 subtype , *INFLUENZA , *VIRUS-like particles , *AVIAN influenza , *PANDEMICS , *CHICKENS , *VIRUS diseases ,BIRD infections - Abstract
• H7N9 VLP composed of HA, NA and M1 genes was generated in BEVS via coinfection strategy. • H7N9 VLP has strong immunogenicity and excellent efficacy both in chickens and mice. • H7N9 VLP significantly reduces virus shedding and viral replication in chickens and mice. • H7N9 VLP dramatically alleviates pulmonary lesions induced by H7N9 virus in chickens and mice. • H7N9 VLP significantly diminishes key inflammatory cytokine expression in mouse lung. Currently, highly pathogenic avian influenza (HPAI) H7N9 viruses still pose a potential pandemic threat. Influenza virus-like particle (VLP) is one of the most promising vaccine strategies to complement traditional egg-dependent vaccines. Here, we generated a H7N9 VLP vaccine candidate by baculovirus expression system and evaluated its efficacy in chickens and mice. The H7N9 VLP was produced through co-infection of Sf9 insect cells with three recombinant baculoviruses expressing individual HA, NA and M1 gene of the HPAI H7N9 virus A/chicken/Guangdong/GD15/2016. Intramuscular immunization of the H7N9 VLP elicited robust antibody immune responses and conferred complete clinical protection against lethal H7N9 virus challenge both in chickens and mice. Meanwhile, H7N9 VLP significantly restrained virus shedding and dramatically alleviated pulmonary lesions caused by H7N9 virus infection in birds and mice. Interestingly, chicken antibodies induced by the H7N9 VLP also had a good cross-reactivity with H7N9 field strains isolated in different years. In addition, vaccination with the H7N9 VLP elicited high T cell immunity in mouse lung, evidenced by significantly upregulated expression of IL-2, IL-4 and IFN-γ. Furthermore, the H7N9 VLP significantly decreased the expression of some key inflammatory cytokines, such as IL6, RANTES and TNF-α in mouse lung, which may partially account for its contribution to alleviate lung pathology. Therefore, our study describes the good efficacy of the HA + NA + M1-containing H7N9 VLP both in chicken and mice models, highlighting the potential of VLP-based vaccine as a critical alternative of traditional egg-based vaccine for control of H7N9 influenza virus in both humans and poultry. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
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