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Ensemble learning prediction of soybean yields in China based on meteorological data

Journal of Integrative Agriculture 2023年第6期22卷 1909-1927页

作者： LI Qian-chuan XU Shi-wei ZHUANG jia-yu liu jia-jia ZHOU Yi ZHANG Ze-xi Agricultural Information Institute Chinese Academy of Agricultural SciencesBeijing 100081P.R.China Beijing Engineering Research Center for Agricultural Monitoring and Early Warning Beijing 100081P.R.China Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100094P.R.China The Department of Mathematics Columbia UniversityNY 10027USA Key Laboratory of Agricultural Monitoring and Early Warning Technology Ministry of Agriculture and Rural AffairsBeijing 100081P.R.China

The accurate prediction of soybean yield is of great significance for agricultural production, monitoring and early *** previous studies have used machine learning algorithms to predict soybean yield based on meteorological data,it is not clear how different models can be used to effectively separate soybean meteorological yield from soybean yield in various regions. In addition, comprehensively integrating the advantages of various machine learning algorithms to improve the prediction accuracy through ensemble learning algorithms has not been studied in depth. This study used and analyzed various daily meteorological data and soybean yield data from 173 county-level administrative regions and meteorological stations in two principal soybean planting areas in China(Northeast China and the Huang–Huai region), covering 34 *** effective machine learning algorithms(K-nearest neighbor, random forest, and support vector regression) were adopted as the base-models to establish a high-precision and highly-reliable soybean meteorological yield prediction model based on the stacking ensemble learning framework. The model's generalizability was further improved through 5-fold crossvalidation, and the model was optimized by principal component analysis and hyperparametric optimization. The accuracy of the model was evaluated by using the five-year sliding prediction and four regression indicators of the 173 counties, which showed that the stacking model has higher accuracy and stronger robustness. The 5-year sliding estimations of soybean yield based on the stacking model in 173 counties showed that the prediction effect can reflect the spatiotemporal distribution of soybean yield in detail, and the mean absolute percentage error(MAPE) was less than 5%. The stacking prediction model of soybean meteorological yield provides a new approach for accurately predicting soybean yield.

关键词： meteorological factors ensemble learning crop yield prediction machine learning county-level

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Periodontal Ligament Stem Cells Reverse the High Glucose Level-Induced Inflammatory State of Macrophages

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Biomedical and Environmental Sciences 2022年第7期35卷 674-679页

作者： liu Yun Xia DING Xiao Ling TANG Shuai CUI Shu Yue liu jia jia DING Gang School of Stomatology Weifang Medical UniversityWeifang 261053ShandongChina Clinical Competency Training Center Weifang Medical UniversityWeifang 261053ShandongChina

Periodontitis is a chronic infectious disease characterized by plaque biofilm as its main pathogenic factor;its clinical manifestations include gingival inflammation,alveolar bone resorption,attachment loss,and periodontal pocket formation,all of which eventually lead to tooth loss and seriously affect the quality of life of patients[1].This illness has a close relationship with blood sugar levels in patients with diabetes and is one of the most important complications of diabetes[2].Macrophages are an important part of host immune responses and exhibit powerful functions of identifying,phagocytizing,and removing bacteria;macrophage polarization is involved in the pathogenesis of periodontitis[3].

关键词： inflammation removing eventually

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Anti-OX40 Antibody Combined with HBc VLPs Delays Tumor Growth in a Mouse Colon Cancer Model

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Biomedical and Environmental Sciences 2024年第2期37卷 187-195页

作者： liu jia jia SU Qiu Dong YI Yao SHEN Li Ping BI Sheng Li National Institute for Viral Disease Control and Prevention Chinese Center for Disease Control and PreventionBeijing 102206China

Objective Combination immunotherapy strategies targeting OX40,a co-stimulatory molecule that can enhance antitumor immunity by modulating the proliferation,differentiation,and effector function of tumor-infiltrating T cells,have attracted much attention for their excellent therapeutic *** this study,we aimed to evaluate the antitumor efficacy of combined anti-OX40 and hepatitis B core viruslike particles(HBc VLPs)therapy using a mouse colon cancer *** Humanized B-h OX40 mice were injected subcutaneously with MC38 colon tumor cells and treated with HBc VLPs+anti-h OX40 *** growth was *** cytometric analysis was performed to evaluate the populations of T cell subsets in the *** The combination of anti-OX40 with HBc VLPs resulted in a significant delay in tumor growth,suggesting that a potent antitumor immunity was induced by the combination *** studies revealed that HBc VLPs+anti-OX40 treatment induced a significant increase in effector T cells(Teffs)and a significant decrease in regulatory T cells(Tregs)in the tumor microenvironment(TME),which accounted for the synergistic antitumor effect of anti-OX40 in combination with HBc *** Combination therapy of anti-h OX40 and HBc VLPs provides synergistic antitumor activity in colon cancer-bearing mice,which may represent a potential design strategy for cancer immunotherapy.

关键词： Anti-OX40 antibody Hepatitis B core virus-like particles Tumor Combination therapy

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Genetic diversity of Ustilago hordei in Tibetan areas as revealed by RAPD and SSR

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Journal of Integrative Agriculture 2016年第10期15卷 2299-2308页

作者： ZHOU Yu CHAO Gui-mei liu jia-jia ZHU Ming-qi WANG Yang FENG Bai-li State Key Laboratory of Crop Stress Biology for Arid Areas/College of Agronomy Northwest A&F University State Key Laboratory of Crop Stress Biology for Arid Areas/College of Plant Protection Northwest A&F University

Covered smut, which is caused by Ustilago hordei（Pers.） Lagerh., is one of the most damaging diseases of highland barley（Hordeum vulgare Linn. var. nudum Hook. f） in Tibetan areas of China. To understand the molecular diversity of U. hordei, a total of 27 isolates, which were collected from highland barley plants from Tibet, Sichuan, Qinghai, and Gansu provinces/autonomous region, were analyzed using random amplified polymorphic DNA（RAPD） and simple sequence repeat（SSR） markers. Among the 100 RAPD primers used, 24 primers exhibited polymorphism. A total of 111 fragments were amplified, of which 103 were polymorphic with a polymorphic rate of 92.79%. The average observed number of alleles（Na）, effective number of alleles（Ne）, Nei＇s genetic diversity（H）, Shannon＇s information index（I） and polymorphism information content（PIC） value in the RAPD markers were 1.9279, 1.5016, 0.2974, 0.4503 and 0.6428, respectively. For the SSR markers, 40 of the 111 primer pairs exhibited polymorphism and provided a total of 119 bands, of which 109 were polymorphic and accounted for 91.60% of the total bands. The Na, Ne, H, I and PIC values of the SSR markers were 1.9160, 1.4639, 0.2757, 0.4211 and 0.4340, respectively. The similarity coefficients ranged from 0.4957 to 0.9261 with an average of 0.7028 among all the 27 isolates used. The dendrogram, which was developed based on the RAPD and SSR combined marker dataset showed that the 27 U. hordei isolates were divided into 3 clusters at similarity coefficient of 0.7314. We determined that RAPD and SSR markers can be successfully used to assess the genetic variation among U. hordei isolates. The RAPD markers revealed higher levels of genetic polymorphism than did the SSR markers in this study. There existed a moderate genetic difference among isolates. The molecular variation and differentiation was somewhat associated with geographical origin but not for all of the isolates.

关键词： highland barley Ustilago hordei RAPD SSR genetic diversity

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The effects of soil properties, cropping systems and geographic location on soil prokaryotic communities in four maize production regions across China

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Journal of Integrative Agriculture 2022年第7期21卷 2145-2157页

作者： TIAN Xue-liang liu jia-jia liu Quan-cheng XIA Xin-yao PENG Yong Alejandra I.HUERTA YAN jian-bing LI Hui liu Wen-de State Key Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing 100193P.R.China Henan Engineering Research Center of Biological Pesticide&Fertilizer Development and Synergistic Application Henan Institute of Science and TechnologyXinxiang 453003P.R.China School of Biological Science and Technology University of JinanJinan 250022P.R.China National Key Laboratory of Crop Genetic Improvement Huazhong Agricultural UniversityWuhan 430070P.R.China Department of Entomology and Plant Pathology North Carolina State UniversityRaleigh 27606USA

The diversity of prokaryotic communities in soil is shaped by both biotic and abiotic ***,little is known about the major factors shaping soil prokaryotic communities at a large scale in *** this end,we undertook a study to investigate the impact of maize production cropping systems,soil properties and geographic location(latitude and longitude)on soil prokaryotic communities using metagenomic techniques,across four distinct maize production regions in *** all study sites,the dominant prokaryotes in soil were Alphaproteobacteria,Gammaproteobacteria,Betaproteobacteria,Gemmatimonadetes,Acidobacteria,and ***-metric multidimensional scaling revealed that prokaryotic communities clustered into the respective maize cropping systems in which they *** analysis(RDA)showed that soil properties especially pH,geographic location and cropping system jointly determined the diversity of the prokaryotic *** functional genes of soil prokaryotes from these samples were chiefly influenced by latitude,soil pH and cropping system,as revealed by RDA *** abundance of genes in some metabolic pathways,such as genes involved in microbe–microbe interactions,degradation of aromatic compounds,carbon fixation pathways in prokaryotes and microbial metabolism were markedly different across the four maize production *** study indicated that the combination of soil pH,cropping system and geographic location significantly influenced the prokaryotic community and the functional genes of these *** work contributes to a deeper understanding of the composition and function of the soil prokaryotic community across large-scale production systems such as maize.

关键词： metagenome cropping system maize soil prokaryotes

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Stability of tunnel excavation surface based on experiments of transparent soil

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Yantu Lixue/Rock and Soil Mechanics 2020年 41卷 306-310页

作者： Ma, Zhong-Wu Sun, Ji-Zhu liu, jia-jia College of Civil Engineering and Architecture Wuhan University of Technology Wuhan 430070 China Wuhan 430200 China

Due to the difficulty in observing the deformation of soil around tunnels under the ground surface, the transparent soil formed by the melted quartz and calcium bromide solution is applied in studying the instability of excavation surface of the shield. The displacement vector, settlement trough curve and failure mode of the soil in front of the tunnel are obtained. The test results show that the vertical displacement is the main deformation form of soil after the instability of tunnel excavation surface. When the tunnel is buried shallowly, the soil failure presents the wedge shape and the failure surface extends to the ground surface. When the buried depth of tunnel increases, the disturbance range becomes narrow towards the excavation surface. Besides, the pressure arch appears, and the disturbance body presents the silo-shape when the buried depth of tunnel is deep. The settlement trough in the longitudinal section of the tunnel shows the Weibull distribution. The maximum settlement occurs at the tunnel vault about (0.3-0.5)D (D is the tunnel radius) ahead of the excavation surface of tunnel. The deformation mainly occurs above the tunnel vault in front of the excavation surface of tunnel. When the tunnel is buried at a shallow depth, the settlement trough becomes much deeper and narrower. However, when it is buried deeply, the width of the settlement trough is almost the same and it gradually deepens downward from ground. © 2020, Science Press. All right reserved.

关键词： Deformation

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Morphological diversity and correlation analysis of phenotypes and quality traits of proso millet(Panicum miliaceum L.)core collections

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Journal of Integrative Agriculture 2019年第5期18卷 958-969页

作者： ZHANG Da-zhong Rabia Begum Panhwar liu jia-jia GONG Xiang-wei LIANG Ji-bao liu Minxuan LU Ping GAO Xiao-li FENG Bai-li College of Agronomy Northwest A&F University Agricultural Technology Promotion Center of Shenmu City Institute of Crop Sciences Chinese Academy of Agricultural Sciences

Genetic diversity and comprehensive performance are the basis for the discovery and efficient use of proso millet(Panicum miliaceum L.) core collections. In this study, 386 proso millet core collections were used as materials to observe inflorescence color, leaf phase, inflorescence density, axis shape, branched spike length, panicle type, trichome, measured area of the top3 leaves, and chlorophyll content of the top3 leaves at filling stage. These core collections were also used to record growth period, plant height, diameter of main stem, plant tiller number, branch number, panicle length, panicle number per plant, and panicle weight per plant at the maturation stage. Starch, fat, protein, and yellow pigment contents in the grain and 1 000-seed weight were also measured after harvest. Then, quantitative traits were used for diversity analysis and comprehensive evaluation of each collection. Correlations between all traits were also analyzed. Results showed that among the 8 quality traits, the Shannon index(H′) of hull color was the highest(1.588) followed by the H′ of inflorescence density(0.984). However, inflorescence color and axis shape were lower. The H′ of 16 quantitative traits were significantly higher than the quality traits with the following traits having the highest indices: fat content(2.092), 1 000-seed weight(2.073), top3 leaves area(2.070), main stem diameter(2.056), and plant height(2.052). Furthermore, all other traits had a diversity higher than 1.900. After a comprehensive evaluation of phenotypic traits, plant height, diameter of main stem, plant tiller number, leaf area of top3 leaves, and 1 000-seed weight were the biggest contributors to the principal components. Six high-fat and high-protein cultivars, including Nuoshu, A75-2, Zhiduoaosizhi, Panlonghuangmi, Xiaobaishu, and Xiaohongshu were also screened. Correlations between the quantitative traits were significant, including the correlation between quality traits and quantitative traits.

关键词： proso millet phenotypic traits quality diversity correlation evaluation

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Influence of Heating Rate and Calcining Temperature on Properties of 95 Polycrystalline Alumina Fiber

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China's Refractories 2012年第3期21卷 29-33页

作者： XU jianfeng FU Shunde liu Libin jia jia GAN Xiaoming State Key Laboratory of Advanced Refractories Sinesteel Luoyang Institute of Refractories Research Co.Ltd. Luoyang 471039 China

The swung gel fibers were hea, ted to 400 ℃ at 0. .5 ,1, 1.5,2,2.5,3and4 ℃ min^-1 of heating rate, respectivel, and *** 1 h ; then heated to 600 ℃ at 3 ℃ min ^-1 *** rate amt soaked for 1 h at last calcined m 1 0... 详细信息

关键词： 95 polycrystalline alumina fiber healing rate calcining temperature average single fiber tensile strength

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CVaR风险度量模型在单期发电权交易中的应用

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四川大学学报（工程科学版） 2007年第1期39卷 160-165页

作者：刘嘉佳刘俊勇四川大学电气信息学院四川成都610065

为了研究电力市场环境下发电量在发电权交易市场中的分配比例问题,以条件风险价值(CVaR)为风险计量指标,把发电权交易市场分配的电量作为一种无风险资产,建立了带有CVaR约束的期望收益最大化的投标组合模型,讨论发电商的单期发电权交易... 详细信息

为了研究电力市场环境下发电量在发电权交易市场中的分配比例问题,以条件风险价值(CVaR)为风险计量指标,把发电权交易市场分配的电量作为一种无风险资产,建立了带有CVaR约束的期望收益最大化的投标组合模型,讨论发电商的单期发电权交易量分配策略。仿真结果显示,发电权交易的引入,可以使发电商在获得更大收益的同时,规避其他市场中可能存在的风险。该算法对于发电商参与发电权交易具有一定的参考价值和指导作用。

关键词：电力市场发电权交易单期投标组合条件风险价值

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水循环演变中多因素综合影响贡献量分解方法

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水利学报 2014年第6期45卷 658-665页

作者：刘佳嘉周祖昊贾仰文王浩中国水利水电科学研究院流域水循环模拟与调控国家重点实验室北京100038 水利部水资源与水生态工程技术研究中心北京100038

为了有效计算气候变化和人类活动对流域水循环过程的影响,需对多因素影响贡献量进行分解。由于多因素之间相互影响,单个因素影响量之和,一般并不完全等于所有因素综合影响量,因此传统方法多用于对两个因素进行影响量分解。本文提出一种... 详细信息

为了有效计算气候变化和人类活动对流域水循环过程的影响,需对多因素影响贡献量进行分解。由于多因素之间相互影响,单个因素影响量之和,一般并不完全等于所有因素综合影响量,因此传统方法多用于对两个因素进行影响量分解。本文提出一种基于分布式水文模型的分解方法,用于对多个因素进行影响量分解。该方法能综合考虑不同因素之间的相互作用,使得单因素影响量之和恰好等于所有因素综合影响量,并从理论和应用两个方面对此进行论证。相比于传统方法,新方法能更加科学地分解两个及两个以上因素对水循环过程影响的贡献量,同时在基准期和变化期的选择上也更具有灵活性。该方法不仅可用于水循环演变过程中多因素贡献量分析,还可与具有物理机制的模型相结合,应用于大气、环境和生态演化过程的贡献率分析。

关键词：水循环演变多因素贡献量分解方法

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