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The Forecast Skills and Predictability Sources of Marine Heatwaves in the NUIST-CFS1.0 Hindcasts
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作者 Jing MA haiming xu +1 位作者 Changming DONG Jing-Jia LUO 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第8期1589-1600,共12页
Using monthly observations and ensemble hindcasts of the Nanjing University of Information Science and Technology Climate Forecast System(NUIST-CFS1.0) for the period 1983–2020, this study investigates the forecast s... Using monthly observations and ensemble hindcasts of the Nanjing University of Information Science and Technology Climate Forecast System(NUIST-CFS1.0) for the period 1983–2020, this study investigates the forecast skill of marine heatwaves(MHWs) over the globe and the predictability sources of the MHWs over the tropical oceans. The MHW forecasts are demonstrated to be skillful on seasonal-annual time scales, particularly in tropical oceans. The forecast skill of the MHWs over the tropical Pacific Ocean(TPO) remains high at lead times of 1–24 months, indicating a forecast better than random chance for up to two years. The forecast skill is subject to the spring predictability barrier of El Nino-Southern Oscillation(ENSO). The forecast skills for the MHWs over the tropical Indian Ocean(TIO), tropical Atlantic Ocean(TAO), and tropical Northwest Pacific(NWP) are lower than that in the TPO. A reliable forecast at lead times of up to two years is shown over the TIO, while a shorter reliable forecast window(less than 17 months) occurs for the TAO and NWP.Additionally, the forecast skills for the TIO, TAO, and NWP are seasonally dependent. Higher skills for the TIO and TAO appear in boreal spring, while a greater skill for the NWP emerges in late summer-early autumn. Further analyses suggest that ENSO serves as a critical source of predictability for MHWs over the TIO and TAO in spring and MHWs over the NWP in summer. 展开更多
关键词 marine heatwaves NUIST-CFS1.0 hindcasts forecast skill predictability source ENSO
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Enhanced Spin–Orbit Torques in Graphene by Pt Adatoms Decoration
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作者 王怡飞 张其 +7 位作者 徐海茗 郭玺 常宇晗 张健荣 和孝东 左亚路 崔宝山 席力 《Chinese Physics Letters》 SCIE EI CAS CSCD 2024年第6期141-147,共7页
Graphene(Gr)with widely acclaimed characteristics,such as exceptionally long spin diffusion length at room temperature,provides an outstanding platform for spintronics.However,its inherent weak spin–orbit coupling(SO... Graphene(Gr)with widely acclaimed characteristics,such as exceptionally long spin diffusion length at room temperature,provides an outstanding platform for spintronics.However,its inherent weak spin–orbit coupling(SOC)has limited its efficiency for generating the spin currents in order to control the magnetization switching process for applications in spintronics memories.Following the theoretical prediction on the enhancement of SOC in Gr by heavy atoms adsorption,here we experimentally observe a sizeable spin–orbit torques(SOTs)in Gr by the decoration of its surface with Pt adatoms in Gr/Pt(t Pt)/Fe Ni trilayers with the optimal damping-like SOT efficiency around 0.55 by 0.6-nm-thick Pt layer adsorption.The value is nearly four times larger than that of the Pt/Fe Ni sample without Gr and nearly twice the value of the Gr/Fe Ni sample without Pt adsorption.The efficiency of the enhanced SOT in Gr by Pt adatoms is also demonstrated by the field-free SOT magnetization switching process with a relatively low critical current density around 5.4 MA/cm^(2)in Gr/Pt/Fe Ni trilayers with the in-plane magnetic anisotropy.These findings pave the way for Gr spintronics applications,offering solutions for future low power consumption memories. 展开更多
关键词 MAGNETIZATION exceptional GENERATING
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Responses of the East Asian Jet Stream to the North Pacific Subtropical Front in Spring 被引量:2
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作者 Leying ZHANG haiming xu +1 位作者 Ning SHI Jiechun DENG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2017年第2期144-156,共13页
This study concerns atmospheric responses to the North Pacific subtropical front (NPSTF) in boreal spring over the period 1982-2014. Statistical results show that a strong NPSTF in spring can significantly enhance t... This study concerns atmospheric responses to the North Pacific subtropical front (NPSTF) in boreal spring over the period 1982-2014. Statistical results show that a strong NPSTF in spring can significantly enhance the East Asian jet stream (EAJS). Both transient eddy activity and the atmospheric heat source play important roles in this process. The enhanced atmospheric temperature gradient due to a strong NPSTF increases atmospheric baroclinicity, resulting in an intensification of transient eddy and convection activities. On the one hand, the enhanced transient eddy activities can excite an anomalous cyclonic circulation with a quasi-baraotropical structure in the troposphere to the north of the NPSTF. Accordingly, the related westerly wind anomalies around 30°N can intensify the component of the EAJS over the Northeast Pacific. On the other hand, an enhanced atmospheric heat source over the NPSTF, which is related to increased rainfall, acts to excite an anomalous cyclonic circulation system in the troposphere to the northwest of the NPSTF, which can explain the enhanced component of the EAJS over the Northwest Pacific. The two mechanisms may combine to enhance the EAJS. 展开更多
关键词 North Pacific subtropical front East Asian jet stream transient eddy activity atmospheric heat source
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Joint association analysis method to dissect complex genetic architecture of multiple genetically related traits 被引量:2
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作者 Feng Lin Guoan Qi +3 位作者 Ting xu Xiangyang Lou Yongbo Hong haiming xu 《The Crop Journal》 SCIE CAS CSCD 2020年第5期733-744,共12页
Genome-wide association study(GWAS)has been a standard approach to discover the genetic determinants underlying complex traits.It is a major challenge in GWAS how to improve analysis power,uncover complex genetic corr... Genome-wide association study(GWAS)has been a standard approach to discover the genetic determinants underlying complex traits.It is a major challenge in GWAS how to improve analysis power,uncover complex genetic correlation,and reveal gene-gene and gene-environment interactions through integrated analysis of multiple genetically related traits.To combat these challenges,we proposed a mixed linear model-based joint association analysis method for multiple traits,which include epistasis and geneenvironment interaction in the mapping model and utilize within-trait variance and between-trait covariance simultaneously;A F-statistics based on Wilks statistics is used to test the significance of each SNP and paired interacted SNPs,each genetic effects of QTS are estimated and tested by the MCMC method based on a QTS full model.Simulations showed that the multi-trait GWAS method could provide increased power in detecting pleiotropic loci affecting more than one trait,and can unbiasedly estimate effects of QTS.To demonstrate the performance of the proposed method,we analyzed four blood lipid traits in Multi-Ethnic Study of Atherosclerosis(MESA)Cohort and two yield-related traits in a rice immortalized F2 dataset.A software package was developed for the proposed method. 展开更多
关键词 TRAITS analysis complex
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Interdecadal Variations of ENSO Impacts over the Indo-Northwest Pacific Region and the Related Mechanisms
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作者 Hongxia LAN Jing MA +1 位作者 haiming xu Jingjia LUO 《Journal of Meteorological Research》 SCIE CSCD 2024年第2期235-248,共14页
Owing to limited observations,it remains unknown whether the impact of El Niño-Southern Oscillation(ENSO)on the Indian Ocean-Northwest Pacific(IO-NWP)climate showed decadal changes in the early 20th century.Using... Owing to limited observations,it remains unknown whether the impact of El Niño-Southern Oscillation(ENSO)on the Indian Ocean-Northwest Pacific(IO-NWP)climate showed decadal changes in the early 20th century.Using multi-source reanalysis and hindcast datasets from the ECMWF and NOAA extending back to 1901,this study investigates interdecadal variations of the impact of ENSO on the IO-NWP climate from 1901 to 2009.It is found that the influence of ENSO on the IO-NWP climate shows“strong-weak-strong”interdecadal change during 1901-2009.This is characterized by much weaker Indian Ocean sea surface temperature(SST)warming and a weaker NWP subtropical anticyclone(NWPSA)in the following summer of El Ni?o during 1946-1967,compared with those in the other two periods(1901-1945 and 1968-2009).Analyses of the datasets indicate that the interdecadal variation is mainly associated with the change in ENSO amplitude.In contrast to the period of 1946-1967,a greater SST variance occurred in the central-eastern equatorial Pacific during 1901-1945 and 1968-2009.A stronger El Ni?o tends to generate more significant anticyclonic anomalies over the southeast Indian Ocean through teleconnection.The northwesterly anomalies to the south of the anticyclone weaken the southeast trade winds and warm the south Indian Ocean SST via wind-evaporation-SST feedback,and the positive south Indian Ocean SST anomalies trigger westward-propagating oceanic Rossby waves to induce stronger warming of the southwest Indian Ocean,leading to a significant asymmetric wind pattern across the equator in spring.The profound northeastward winds on the north side weaken the southwest monsoon,leading to a“second warming”over the north Indian Ocean in summer,which anchors the eastward-propagating warm Kelvin waves and results in a stronger NWPSA by inducing surface divergence and suppressing deep convection. 展开更多
关键词 ENSO Indo-Northwest Pacific Northwest Pacific subtropical anticyclone decadal changes
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On the spring stratospheric final warming in CMIP5 and CMIP6 models
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作者 Jinggao HU Zexuan LIU +2 位作者 haiming xu Rongcai REN Dachao JIN 《Science China Earth Sciences》 SCIE EI CAS CSCD 2023年第1期129-145,共17页
This study evaluates the performance in simulating the stratospheric final warming events(SFWs)that lead to the final collapse of the stratospheric polar vortex in spring in both Southern and Northern Hemispheres(SH a... This study evaluates the performance in simulating the stratospheric final warming events(SFWs)that lead to the final collapse of the stratospheric polar vortex in spring in both Southern and Northern Hemispheres(SH and NH,respectively)based on the historical simulations provided by the Coupled Model Intercomparison Project Phases 5 and 6(CMIP5 and CMIP6,respectively).Overall,CMIP5 and CMIP6 models can reproduce the main characteristics of the occurrence of SFWs.However,the SFW onset date(SFWOD)is 7 and 9 days later than in observations in the SH and NH,respectively.Moreover,the intensity of SFWs in models is 50%to 70%of that in observations.Compared with CMIP5 models,CMIP6 models have an ameliorated capability to simulate NH SFWs.However,this improvement does not manifest as significantly earlier SFW onset,but as more intense stratospheric planetary wave activities before the SFWand as a larger interannual variability of the SFWOD.By contrast,in the SH,the capability of CMIP6 models is roughly unchanged,even deteriorated in the simulation of SFWOD and stratospheric planetary wave activities before the SFW onset.The performance of CMIP6 high-top models is better than that of lowtop models.Specifically,in the NH,high-top models are considerably improved in terms of intensity of circumpolar zonal wind around the SFWOD and stratospheric planetary wave activities before the SFW onset.In the SH,high-top models show fairly earlier SFWOD by 11 days,which is closer to observations. 展开更多
关键词 Stratospheric final warming events CMIP5 and CMIP6 models Historical simulation Southern and Northern Hemispheres
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杭州市下城区50岁及以上人群眼病流行病学调查 被引量:19
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作者 徐海铭 王鑫 龚静文 《中华眼视光学与视觉科学杂志》 CAS CSCD 2018年第6期333-338,共6页
目的:调查杭州市下城区50岁及以上人群眼部疾病的患病情况及盲和中、重度视力损伤的患病率及病因。方法:横断面调查研究。于2015年4-8月期间采用整群随机抽样方法,从杭州市下城区8个街道共抽取50岁及以上人群2 953例,对其进行视力、屈... 目的:调查杭州市下城区50岁及以上人群眼部疾病的患病情况及盲和中、重度视力损伤的患病率及病因。方法:横断面调查研究。于2015年4-8月期间采用整群随机抽样方法,从杭州市下城区8个街道共抽取50岁及以上人群2 953例,对其进行视力、屈光状态、眼压等检查,分析不同年龄、性别和受教育程度人群盲和中、重度视力损伤的患病率及病因。各数据间的比较采用χ2检验和趋势χ2检验。结果:共2 363例接受并完成了检查,受检率为80%,人群中盲和中、重度视力损伤的患病率为1.6%(38例),并随着年龄增长而上升(χ2=38.094,P<0.001);文化程度越低,盲的患病率越高(χ2=39.497,P<0.001)。导致盲和中、重度视力损伤的主要原因有眼底异常(30眼,39.5%)、白内障(26眼,34.2%)、青光眼(12眼,15.8%)等。人群中眼病患病率由高到低依次为未矫正的屈光不正(2 048例,86.7%)、白内障(1 065例,44.7%)、翼状胬肉(219例,9.3%)、年龄相关性黄斑变性(81例,3.5%)、青光眼(52例,2.2%)、斜视(46例,2.0%)、糖尿病视网膜病变(39例,1.7%)。结论:杭州市下城区50岁及以上人群常见的眼部疾病是未矫正的屈光不正、白内障。盲和中、重度视力损伤的患病率较低,其中眼底异常、白内障是导致盲和中、重度视力损伤的主要原因。 展开更多
关键词 眼病 患病率 社区 杭州
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Polybrominated diphenyl ether (PBDE) in blood from children (age 9–12) in Taizhou, China 被引量:5
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作者 Xiaoyou Zhang Xianli Ruan +6 位作者 Minchan Yan Yaxian Zhao Wuji Wei Zhanfen Qin Yongjian Yang haiming xu Yan Li 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2011年第7期1199-1204,共6页
Polybrominated diphenyl ethers (PBDEs) as ubiquitous persistent organic pollutants have attracted much attention in recent years. Exposure to PBDEs could induce a high health risk for children. The aim of this study... Polybrominated diphenyl ethers (PBDEs) as ubiquitous persistent organic pollutants have attracted much attention in recent years. Exposure to PBDEs could induce a high health risk for children. The aim of this study was to investigate the PBDEs exposure of children (9–12 years) from Taizhou, China. Fifty-eight blood samples were collected in one school in a mountainous area in Taizhou. The concentrations of ∑9PBDEs (sum of BDE-28, -47, -99, -100, -153, -154, -183, -197 and -209) ranged from 2.66 to 33.9 ng/g lipid wet (lw) with a median of 7.22 ng/g lw. These concentrations were lower than those of children in USA, but close to European and Asian general population levels. The results showed that children in Taizhou countryside were at a low level of PBDEs exposure. The predominant congener was BDE-209, followed by BDE-28, -47, -197 and -153. High abundance of BDE-209 was consistent with the pollution background of PBDEs in China characterized by high brominated congeners as main pollutants. 展开更多
关键词 polybrominated diphenyl ether CHILDREN BLOOD EXPOSURE Taizhou
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Enhanced ozonation degradation of atrazine in the presence of nano-ZnO: Performance, kinetics and effects 被引量:5
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作者 Xiangjuan Yuan xuan Yan +4 位作者 haiming xu Dongya Li Lei Sun Gang Cao Dongsheng Xia 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2017年第11期3-13,共11页
Enhanced ozonation degradation of atrazine(ATZ) with nano-ZnO(nZnO) as catalyst and the influences of the operational parameters have been investigated through semi-continuous experiments in this study. The result... Enhanced ozonation degradation of atrazine(ATZ) with nano-ZnO(nZnO) as catalyst and the influences of the operational parameters have been investigated through semi-continuous experiments in this study. The results demonstrated that the combination of ozone(O3) and nZnO showed an obvious synergetic effect and the ATZ degradation conformed to pseudo-first-order kinetics. An improvement of ATZ degradation efficiency by 41.8% and pseudo-first-order rate constant by more than a factor of four was obtained in the O3/nZnO process after 5 min of reaction compared to O3 alone. Meanwhile, the degradation efficiency of ATZ was gradually enhanced with increasing nZnO dosage and initial pH in the range from 3.0 to 8.0, and a higher amount of ATZ was degraded when the initial concentration of ATZ rose from 0.5 to 5 mg/L. Additionally, sulfate ion, chloride ion, nitrate ion and low concentrations of humic acid substances led to enhancement of the ATZ degradation. The notable decrease of ATZ removal efficiency observed in the presence of radical scavengers and the results of free radical tests indicated thatUOH is the dominant active radical species. The mechanism investigation demonstrated that the enhancement effect could be attributed to the introduction of nZnO,which could promote the utilization of O3, enhance the formation of superoxide radical, and further accelerate the production of hydrogen peroxide and the generation of OH/O2-. 展开更多
关键词 NANO-ZNO ATRAZINE Catalytic ozonation Reaction mechanism
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Relationship of tropical-cyclone-induced remote precipitation with tropical cyclones and the subtropical high 被引量:2
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作者 Rui XING Zhiying DING +1 位作者 Sangjie YOU haiming xu 《Frontiers of Earth Science》 SCIE CAS CSCD 2016年第3期595-606,共12页
This study concerns the precipitation induced by a tropical cyclone (TC) before the TC arrives, which will be referred to as TC remote precipitation (TRP). Based on the distribution characteristics of the non-rota... This study concerns the precipitation induced by a tropical cyclone (TC) before the TC arrives, which will be referred to as TC remote precipitation (TRP). Based on the distribution characteristics of the non-rotational wind and the divergent-wind vertical circulation related to TC, the subtropical high, and TRP of 45 TRP events during June, July, and August of 2000-2009, the relationships among these three entities (TC, subtropical high, and TRP) can be categorized into four patterns. The first pattern accounts for the highest proportion of the TRP events (59%), and a conceptual model is then provided for this pattern. The primary characteristics of this model are as follows: TC, the subtropical high, and TRP can interact with each other through the divergent-wind secondary circulation at both sides of the ridge line of the subtropical high (between the subtropical high and TC, and between the subtropical high and TRP). At the upper level (150 or 200 hPa), the northward non-rotational wind from the TC converged toward the subtropical high ridge line and subsided, and at 950 hPa the divergent wind from the ridge line of the subtropical high converged toward TC; these constructed the secondary circulation between TC and the subtropical high. In the meantime, the southward non- rotational wind at the upper level (150 or 200hPa) from TRP and the divergent wind at 950hPa from the subtropical high ridge line toward TRP constructed the secondary circulation between TRP and the subtropical high. As TC and TRP interacted with each other, the subtropical high ridge line was usually under the down- draft area of the whole atmosphere. The other three patterns are different from the first pattern mainly in terms of the intensity and position of the non-rotational-wind secondary circulation. The numerical simulation of the Beijing 7.21 rainstorm confirmed the relationship amongTC, the subtropical high, and TRP, indicating that when the interaction weakened, the TRP also weakened. 展开更多
关键词 tropical cyclone precipitation subtropical high simulation tropical cyclone remotedivergent wind numerical
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Seasonal variation of the global mixed layer depth: comparison between Argo data and FIO-ESM 被引量:2
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作者 Yutong ZHANG haiming xu +1 位作者 Fangli QIAO Changming DONG 《Frontiers of Earth Science》 SCIE CAS CSCD 2018年第1期24-36,共13页
The present study evaluates a simulation of the global ocean mixed layer depth (MLD) using the First Institute of Oceanography-Earth System Model (FIO- ESM). The seasonal variation of the global MLD from the FIO-E... The present study evaluates a simulation of the global ocean mixed layer depth (MLD) using the First Institute of Oceanography-Earth System Model (FIO- ESM). The seasonal variation of the global MLD from the FIO-ESM simulation is compared to Argo observational data. The Argo data show that the global ocean MLD has a strong seasonal variation with a deep MLD in winter and a shallow MLD in summer, while the spring and fall seasons act as transitional periods. Overall, the FIO-ESM simula- tion accurately captures the seasonal variation in MLD in most areas. It exhibits a better performance during summer and fall than during winter and spring. The simulated MLD in the Southern Hemisphere is much closer to observations than that in the Northern Hemisphere. In general, the simulated MLD over the South Atlantic Ocean matches the observation best among the six areas. Additionally, the model slightly underestimates the MLD in parts of the North Atlantic Ocean, and slightly overestimates the MLD over the other ocean basins. 展开更多
关键词 mixed layer depth FIO-ESM model SEASONALVARIATION
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Index selection on seed traits under direct,cytoplasmic and maternal effects in multiple environments 被引量:1
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作者 Wenying Zhang haiming xu Jun Zhu 《Journal of Genetics and Genomics》 SCIE CAS CSCD 2009年第1期41-49,共9页
Crop seeds are important sources of protein, oil, and carbohydrates for food, animal feeds, and industrial products. Recently, much attention has been paid to quality and functional properties of crop seeds. However, ... Crop seeds are important sources of protein, oil, and carbohydrates for food, animal feeds, and industrial products. Recently, much attention has been paid to quality and functional properties of crop seeds. However, seed traits possess some distinct genetic characteristics in comparison with plant traits, which increase the difficulty of genetically improving these traits. In this study, diallel analysis for seed models with genotype by environment interaction (GE) effect was applied to estimate the variance-covariance components of seed traits. Mixed linear model approaches were used to estimate the genetic covariances between pair-wise seed and plant traits. The breeding values (BV) were divided into two categories for the seed models. The first category of BV was defined as the combination of direct additive, cytoplasmic, and maternal additive effects, which should be utilized for selecting stable cultivars over multi-environments. The three genetic effects, together with their GE interaction, were included in the second category of BV for selecting special lines to be grown in specific ecosystems. Accordingly, two types of selection indices for seed traits, i.e., general selection index and interaction selection index, were developed and constructed on the first and the second category BV, respectively. These proposed selection indices can be applied to solve the difficult task of simultaneously improving multiple seed traits in various environments. Data of crop seeds with regard to four seed traits and four yield traits based on the modified diallel crosses in Upland cotton (Gossypium hirsutum L.) were used as an example for demonstrating the proposed methodology. 展开更多
关键词 index selection seed trait mixed linear model approach genotype by environment interaction
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Molecular characterization and developmental expression patterns of thyroid hormone receptors(TRs) and their responsiveness to TR agonist and antagonist in Rana nigromaculata 被引量:3
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作者 Qinqin Lou Yinfeng Zhang +4 位作者 Dongkai Ren haiming xu Yaxian Zhao Zhanfen Qin Wuji Wei 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2014年第10期2084-2094,共11页
Considering some advantages of Rana nigromaculata as an experimental species, we propose that this species, like Xenopus laevis, could be used to assay thyroid hormone(TH) signaling disrupting actions. To validate t... Considering some advantages of Rana nigromaculata as an experimental species, we propose that this species, like Xenopus laevis, could be used to assay thyroid hormone(TH) signaling disrupting actions. To validate the utilizability of R. nigromaculata, we investigated the responsiveness of R. nigromaculata to a TH receptor(TR) agonist(T3) and antagonist(amiodarone) by analyzing expression, based on characterizing TR cDNA and developmental expression patterns. With high levels of identity with the corresponding genes in X. laevis, both TRα and TRβ in R. nigromaculata exhibited roughly similar developmental expression patterns to those of X. laevis, in spite of some species-specific differences. Both TRα and TRβ expression had greater changes in the liver and intestine than in the tail and brain during metamorphosis. T3 exposure for 2 days induced more dramatic increases of TRβ expression in stage 27 than in stage34 tadpoles but not in stage 42 tadpoles, showing that the responsiveness of R. nigromaculata to TH decreased with development and disappeared at the onset of metamorphic climax.Corresponding to greater changes of TRβ expression in the liver and intestine than in the tail and brain during metamorphosis, the liver and intestine had higher responsiveness to exogenous T3 than the tail and brain. Amiodarone inhibited T3-induced TRβ expression. Our results show that R. nigromaculata can be used as a model species for assaying TH signaling disrupting actions by analyzing TRβ expression, and intestine tissues at stage 27 are ideal test materials due to high responsiveness and easy accessibility. 展开更多
关键词 Rana nigromaculata Thyroid hormone receptor Thyroid hormone signaling Developmental expression pattern Responsiveness
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Possible Impact of Spatial and Temporal Non-Uniformity in Land Surface Temperature Data on Trend Estimation 被引量:1
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作者 Zhiyu LI Wenjun ZHANG haiming xu 《Journal of Meteorological Research》 SCIE CSCD 2018年第5期819-828,共10页
The present work investigates possible impact of the non-uniformity in observed land surface temperature on trend estimation, based on Climatic Research Unit (CRU) Temperature Version 4 (CRUTEM4) monthly temperatu... The present work investigates possible impact of the non-uniformity in observed land surface temperature on trend estimation, based on Climatic Research Unit (CRU) Temperature Version 4 (CRUTEM4) monthly temperature data-sets from 1900 to 2012. The CRU land temperature data exhibit remarkable non-uniformity in spatial and temporal features. The data are characterized by an uneven spatial distribution of missing records and station density, and dis-play a significant increase of available sites around 1950. Considering the impact of missing data, the trends seem to be more stable and reliable when estimated based on data with 〈 40% missing percent, compared to the data with above 40% missing percent. Mean absolute error (MAE) between data with 〈 40% missing percent and global data is only 0.011℃ (0.014℃) for 1900-50 (1951-2012). The associated trend estimated by reliable data is 0.087℃ decade^-1 (0.186℃ decade^-l) for 1900-50 (1951-2012), almost the same as the trend of the global data. However, due to non-uniform spatial distribution of missing data, the global signal seems mainly coming from the regions with good data coverage, especially for the period 1900-50. This is also confirmed by an extreme test conducted with the records in the United States and Africa. In addition, the influences of spatial and temporal non-uniform features in observation data on trend estimation are significant for the areas with poor data coverage, such as Africa, while insig-nificant for the countries with good data coverage, such as the United States. 展开更多
关键词 temperature trend gridded data NON-UNIFORMITY
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A primal perspective for indefinite kernel SVM problem
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作者 Hui xuE haiming xu +1 位作者 Xiaohong CHEN Yunyun WANG 《Frontiers of Computer Science》 SCIE EI CSCD 2020年第2期349-363,共15页
Indefinite kernel support vector machine(IKSVM)has recently attracted increasing attentions in machine learning.Since IKSVM essentially is a non-convex problem,existing algorithms either change the spectrum of indefin... Indefinite kernel support vector machine(IKSVM)has recently attracted increasing attentions in machine learning.Since IKSVM essentially is a non-convex problem,existing algorithms either change the spectrum of indefinite kernel directly but risking losing some valuable information or solve the dual form of IKSVM whereas suffering from a dual gap problem.In this paper,we propose a primal perspective for solving the problem.That is,we directly focus on the primal form of IKSVM and present a novel algorithm termed as IKSVM-DC for binary and multi-class classification.Concretely,according to the characteristics of the spectrum for the indefinite kernel matrix,IKSVM-DC decomposes the primal function into the subtraction of two convex functions as a difference of convex functions(DC)programming.To accelerate convergence rate,IKSVM-DC combines the classical DC algorithm with a line search step along the descent direction at each iteration.Furthermore,we construct a multi-class IKSVM model which can classify multiple classes in a unified form.A theoretical analysis is then presented to validate that IKSVM-DC can converge to a local minimum.Finally,we conduct experiments on both binary and multi-class datasets and the experimental results show that IKSVM-DC is superior to other state-of-the-art IKSVM algorithms. 展开更多
关键词 INDEFINITE KERNEL support VECTOR MACHINE MULTI-CLASS classification non-convex optimization
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Assessment of the Capability of ENSEMBLES Hindcasts in Predicting Spring Climate in China
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作者 Yitong LIN haiming xu +1 位作者 Jing MA Haijun LI 《Journal of Meteorological Research》 SCIE CSCD 2019年第2期307-322,共16页
Using the hindcasts provided by the Ensemble-Based Predictions of Climate Changes and Their Impacts(ENSEMBLES) project for the period of 1980–2005, the forecast capability of spring climate in China is assessed mainl... Using the hindcasts provided by the Ensemble-Based Predictions of Climate Changes and Their Impacts(ENSEMBLES) project for the period of 1980–2005, the forecast capability of spring climate in China is assessed mainly from the aspects of precipitation, 2-m air temperature, and atmospheric circulations. The ENSEMBELS can reproduce the climatology and dominant empirical orthogonal function(EOF) modes of precipitation and 2-m air temperature, with some differences arising from different initialization months. The multi-model ensemble(MME) forecast of interannual variability is of good performance in some regions such as eastern China with February initialization.The spatial patterns of the MME interannual and inter-member spreads for precipitation and 2-m air temperature are consistent with those of the observed interannual spread, indicating that internal dynamic processes have major impacts on the interannual anomaly of spring climate in China. We have identified two coupled modes between intermember anomalies of the 850-hPa vorticity in spring and sea surface temperature(SST) both in spring and at a lead of 2 months, of which the first mode shows a significant impact on the spring climate in China, with an anomalous anticyclone located over Northwest Pacific and positive precipitation and southwesterly anomalies in eastern China.Our results also suggest that the SST at a lead of two months may be a predictor for the spring climate in eastern China. A better representation of the ocean–atmosphere interaction over the tropical Pacific, Northwest Pacific, and Indian Ocean can improve the forecast skill of the spring climate in eastern China. 展开更多
关键词 ENSEMBLES SEASONAL FORECAST SPRING climate coupled atmosphere-ocean mode
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Development and characterization of monoclonal antibodies against human aryl hydrocarbon receptor
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作者 Wenjing Tian Xinhui Pei +8 位作者 Heidi Qunhui Xie Sherry Li xu Jijing Tian Qin Hu haiming xu Yangsheng Chen Hualing Fu Zhengyu Cao Bin Zhao 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2016年第1期165-174,共10页
Aryl hydrocarbon receptor(Ah R), a ligand-dependent nuclear receptor, is involved in a diverse spectrum of biological and toxicological effects. Due to the lack of three dimensional(3D)crystal or nuclear magnetic ... Aryl hydrocarbon receptor(Ah R), a ligand-dependent nuclear receptor, is involved in a diverse spectrum of biological and toxicological effects. Due to the lack of three dimensional(3D)crystal or nuclear magnetic resonance structure, the mechanisms of these complex effects of AhR remain to be unclear. Also, commercial monoclonal antibodies(mA bs) against human AhR protein(h Ah R), as alternative immunological tools, are very limited. Thus, in order to provide more tools for further studies on h Ah R, we prepared two m Abs(1D6 and 4A6) against h Ah R. The two newly generated m Abs specifically bound to amino acids 484–508(located in transcription activation domain) and amino acids 201–215(located in Per-ARNT-Sim domain)of h Ah R, respectively. These epitopes were new as compared with those of commercial m Abs.The m Abs were also characterized by enzyme-linked immunosorbent assay, western blot,immunoprecipitation and indirect immunofluorescence assay in different cell lines. The results showed that the two m Abs could recognize the linearized AhR s in six different human cell lines and a rat hepatoma cell line, as well as the h Ah R with native conformations. We concluded that the newly generated m Abs could be employed in AhR-based bioassays for analysis of environmental contaminants, and held great potential for further revealing the spatial structure of AhR and its biological functions in future studies. 展开更多
关键词 Aryl hydrocarbon receptor Monoclonal antibody Western blot Immunoprecipitation Indirect immunofluorescence assay
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