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Seasonal influence on the development of parthenotes and cloned embryos in pigs

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Progress in Natural Science:Materials International 2007年第10期17卷 1172-1176页

作者： Zhang Kun1, Zhang Yunhai3,4, Pan Dengke5, Ma Yufang1, Wei Hengxi1, Zhang Jian6, Li Xuyang7, Wang Shaohua1, Li Yan2, Dai Yunping1,2 and Li Ning1(1. State Key Laboratory for Agrobiotechnology, College of Biological Science, china agricultural university, beijing 100094, china 2. JiPulin Biotech Ltd., beijing 100094, china 3. Danish Institute of agricultural Sciences, 8830 Tjele, Denmark 4. College of Animal Science and Technology, Anhui agricultural university, Hefei 230036, china 5. Institute of Animal Sciences, Chinese Academy of agricultural Sciences, beijing 100094, china 6. Animal Clinical Hospital, china agricultural university, beijing 100094, china 7. Hebei Minghui Group of Pigs Breeding, Sanhe 065200, china) State Key Laboratory for Agrobiotechnology College of Biological Science China Agricultural University Beijing 100094 China JiPulin Biotech Ltd. Beijing 100094 China Danish Institute of agricultural Sciences 8830 Tjele Denmark College of Animal Science and Technology Anhui Agricultural University Hefei 230036 China Institute of Animal Sciences Chinese Academy of Agricultural Sciences Beijing 100094 China Animal Clinical Hospital China Agricultural University Beijing 100094 China 7. Hebei Minghui Group of Pigs Breeding Sanhe 065200 China

Seasonal influence on the developmental ability of porcine embryos was studied by comparisons of the number of cumulus-oocytes-complexes (COCs) per ovary pair and meiotic maturation ability of oocytes in different seasons; and by the observations on developmental competence of the parthenogenetic oocytes and cloned embryos collected from different seasons. We found that the number of COCs per ovary pairs was significantly higher in spring compared to the other seasons (P<0.05). However, no significant difference was found in the rate of oocytes progressing to MⅡ in four seasons (P<0.05). In addition, the rate of blastocyst formation of parthenogenetic embryos in summer was obviously declined compared to the other seasons (P<0.05), and an increased blastocyst rate of cloned porcine embryos was found in spring compared to autumn and winter (P<0.05). The results suggest that there should be a seasonal influence on the developmental competence of porcine embryos.

关键词： pig cloned parthenogenetic season

Integrating MODFLOW and GIS technologies for assessing impacts of irrigation management and groundwater use in the Hetao Irrigation District,Yellow River basin

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Science china(Technological Sciences) 2009年第11期52卷 3257-3263页

作者： XU Xu1,2, HUANG GuanHua1,2 & QU ZhongYi3 1 Center for Agriculture Water Research, china agricultural university, beijing 100083, china 2 Chinese-Israeli International Center for Research and Training in Agriculture, china agricultural university, beijing 100083, china 3 Water Conservancy and Civil Engineering College, Inner Mongolia agricultural university, Hohhot 010018, china 1. Center for Agriculture Water Research China Agricultural University Beijing 100083 China 2. Chinese-Israeli International Center for Research and Training in Agriculture China Agricultural University Beijing 100083 China 3. Water Conservancy and Civil Engineering College Inner Mongolia Agricultural University Hohhot 010018 China

Due to severe water scarcity, water resources used in agricultural sector have been reduced markedly in Hetao irrigation district. Application of water-saving practices (WSPs) is required for the sustainable agricultural development. The human activities including WSPs and increase of groundwater abstraction can lower down the groundwater table, which is helpful to the salinity control. Meanwhile, an excessively large groundwater table depth may result in negative impact on crop growth and fragile ecological environment. In this paper, the Jiefangzha irrigation system in Hetao irrigation district was selected as a typical area, a groundwater flow model based on ArcInfo Geographic Information System (GIS) was developed and implemented to quantify the effect of human activities on the groundwater system in this area. The preand post-processing of model data was performed efficiently by using the available GIS tools. The time-variant data in boundary conditions was further edited in Microsoft Excel with programs of Visual Basic for Application (VBA). The model was calibrated and validated with independent data sets. Application of the model indicated that it can well describe the effect of human activities on groundwater dynamics in Jiefangzha irrigation system.

关键词： groundwater flow modeling MODFLOW GIS water-saving practices irrigation district

Mechanisms of invasive population establishment and spread of pinewood nematodes in china

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Science china(Life Sciences) 2009年第6期52卷 587-594页

作者： XIE BingYan1,CHENG XinYue2,SHI Juan3,ZHANG QingWen4,DAI ShuMing1,CHENG Fei Xue2 & LUO YouQing3 1 Institute of Vegetables and Flowers,Chinese Academy of agricultural Sciences,beijing 100081,china 2 beijing Normal university,beijing 100875,china 3 beijing Forestry university,beijing 100083,china 4 Chinese agricultural university,beijing 100094,china 1. Institute of Vegetables and Flowers Chinese Academy of Agricultural Sciences Beijing 100081 China 2. beijing Normal university Beijing 100875 China 3. beijing Forestry university Beijing 100083 China 4. Chinese agricultural university Beijing 100094 China

This paper summarizes the results of our study of the pinewood nematode(Bursaphelenchus xylophi-lus).By population genetic analysis,it was determined that there was no genetic bottle caused by the founder effect and genetic drift in the Chinese invasive *** invasions with large amounts of nematodes from different sources led to rich genetic diversity in the invasive *** high genetic diversity in the invasive process may be one of the genetic mechanisms in its successful *** testing interspecies competition,it was shown that,with high fecundity and a strong competitive ability,*** outcompeted the native species *** in the natural ecosystem during the invasion *** displacement may be one of the ecological mechanisms of ***'s *** addition,an unequal interspecific hybridization with intro-gress was in favor of the invasive species which also accelerated the replacement of *** by *** structures,functions and evolutions of a few important genes that are closely related to the ecological adaptation of pinewood nematodes were studied to explore the molecular mechanism of its ecological ***,the resistance and resilience mechanism of the pine ecosystem invaded by pinewood nematodes was also *** results of these studies uncovered a portion of the genetic and ecological mechanisms of PWN's successful invasion and laid a foundation for further study to obtain a comprehensive interpretation of the mechanisms of the nematode *** results also provided a scientific basis for effectively controlling the occurrence and spread of pine wilt disease which is caused by *** aspects requiring further investigation are considered.

关键词： pinewood nematode bioinvasion genetic diversity ecological adaptation resistance resilience

CHEMICAL　INCORPORATING　PESTICIDES　***　OF　NEW　SUCCINIMIDO　ORGANOPHOSPHATES　AS　POTENTIAL　PESTICIDES

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Chinese Chemical Letters 1996年第7期7卷 609-610页

作者： Er Le ZANG He Hui ZHENG Ping LI(Department of Applied Chemistry,china agricultural university.beijing 100094) beijing AGR UNIV DEPT APPL CHEMBEIJING 100094PEOPLES R CHINA

A series of succinimido-organophosphate analogueswas synthesized with maleic anhydride as starting material viamaleimide and its analogues as intermediates and characterized by IR,1HNMR and elementary analysis.

关键词： AS ORGANOPHOSPHATES INCORPORATING CHEMICAL

Pattern phenomena in an rf discharge dusty plasma system

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Science china(Physics,Mechanics & Astronomy) 2006年第5期49卷 588-596页

作者： HUANG Feng1,2, YE Maofu2 & WANG Long2 1. College of Science, china agricultural university, beijing 100083, china 2. Institute of Physics, Chinese Academy of Sciences, beijing 100080, china 1. College of Science China Agricultural University Beijing 100083 China 2. Institute of Physics Chinese Academy of Sciences Beijing 100080 China

Various dust patterns are observed in an rf discharge dusty plasma system. According to the dust growth process from small to large in size, the formation of different dust patterns can be divided into two stages: the small-particle stage (or dust cloud stage), and the large-particle stage (or dust crystal stage). The evolution relations between different dust patterns with gas pressure changing are investigated. Dust voids, dust acoustic waves and strong turbulence modes are presented at the small-particle stage. The self-organized dust lattices and dust clusters are investigated at the large-particle stage. The static structure of a dust lattice is characterized by means of the pair correlation function. Dust clusters formed by particles with different numbers and the regular evolution of the clusters with gas pressure are also investigated. The packing sequences of dust clusters are verified through two-dimensional confined molecular dynamics simulations.

关键词： dusty plasma dust patterns

The refined theory of deep rectangular beams for symmetrical deformation

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Science china(Physics,Mechanics & Astronomy) 2009年第6期52卷 919-925页

作者： GAO Yang1 & WANG MinZhong2 1 College of Science, china agricultural university, beijing 100083, china 2 State Key Laboratory for Turbulence and Complex Systems and Department of Mechanics and Aerospace Engineering, Peking university, beijing 100871, china College of Science China Agricultural University Beijing 100083 China State Key Laboratory for Turbulence and Complex Systems and Department of Mechanics and Aerospace Engineering Peking University Beijing 100871 China

Based on elasticity theory, various one-dimensional equations for symmetrical deformation have been deduced systematically and directly from the two-dimensional theory of deep rectangular beams by using the Papkovich-Neuber solution and the Lur'e method without ad hoc assumptions, and they construct the refined theory of beams for symmetrical deformation. It is shown that the displacements and stresses of the beam can be represented by the transverse normal strain and displacement of the mid-plane. In the case of homogeneous boundary conditions, the exact solutions for the beam are derived, and the exact equations consist of two governing differential equations: the second-order equation and the transcendental equation. In the case of non-homogeneous boundary conditions, the approximate governing differential equations and solutions for the beam under normal loadings only and shear loadings only are derived directly from the refined beam theory, respectively, and the correctness of the stress assumptions in classic extension or compression problems is revised. Meanwhile, as an example, explicit expressions of analytical solutions are obtained for beams subjected to an exponentially distributed load along the length of beams.

关键词： deep rectangular beams the refined theory symmetrical deformation the Papkovich-Neuber solution the Lur’e method

Research on the method for retrieving soil moisture using thermal inertia model

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Science china Earth Sciences 2006年第5期49卷 539-545页

作者： LIU Zhenhua1 & ZHAO Yingshi2 1. Information College, South china agricultural university, Guangzhou 510642, china 2. Graduate university of Chinese Academy of Sciences, beijing 100049, china 1. Information College South China Agricultural University Guangzhou 510642 China 2. Graduate university of Chinese Academy of Sciences Beijing 100049 China

In order to improve accuracy of soil moisture inversion using remote sensing, a new thermal inertia model is proposed in this paper. The improved model needs only surface maximum temperature as the temperature parameter input instead of input of the surface temperature difference, as well as the surface sensible and latent fluxes are introduced into boundary conditions of thermal conductivity equation. Furthermore, surface soil conductive heat transfer equation of two-layer model is used to solve the soil thermal inertia so that the remote sensing thermal inertia method can be ap- plied to regions with better-covered vegetation, but usually only for the bare areas or worse vegetation covered areas. The model has been tested at several locations in the area of west Inner Mongolia. Comparing the simulation of the new model with the measurements obtained by apparent thermal inertia and by field test, the result shows that the inertia thermal model can be used to estimate soil moisture in more reasonable accuracy.

关键词： thermal model, thermal conductivity equation, soil initial, sensible flux, latent flux, two-layer model.

Simulation study on the efficiencies of MOET nucleus breeding schemes applying marker assisted selection in dairy cattle

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Science china(Life Sciences) 2009年第3期52卷 296-306页

作者： LUO WeiZhen,WANG YaChun & ZHANG Yuan Department of Animal Genetics & Breeding,College of Animal Science and Technology,china agricultural university,beijing 100094,china 1. Department of Animal Genetics & Breeding College of Animal Science and Technology China Agricultural University Beijing 100094 China

Advantages of breeding schemes using genetic marker information and/or multiple ovulation and embryo transfer(MOET) technology over the traditional approach were extensively evaluated through *** yield was the trait of interest and QTL was the genetic marker *** dairy cattle breeding scenarios were considered,i.e.,traditional progeny testing breeding scheme(denoted as STANPT),GASPT scheme including a pre-selection of young bulls entering progeny testing based on their own QTL information,MOETPT scheme using MOET technology to generate young bulls and a selection of young bulls limited within the full-sib family,GAMOPT scheme adopting both QTL pre-selection and MOET technology,COMBPT scheme using a mixed linear model which considered QTL genotype instead of the BLUP model in GAMOPT,and three non-progeny testing schemes,*** MOET,GAMO and COMB schemes,corresponding to MOETPT,GAMOPT and COMBPT with progeny testing being part of the *** were selected based on their breeding value which was estimated under an animal model *** selection over 17 years was performed in the simulations and 30 replicates were designed for each *** influences of using QTL information and MOET technology on favorable QTL allele frequency,true breeding values,polygenetic breeding values and the accumulated genetic superiority were extensively evaluated,for five different populations including active sires,lactating cows,bull dams,bull sires,and young *** results showed that the combined schemes significantly outperformed other approaches wherein accumulated true breeding value *** difference between schemes exclusively using QTL information or MOET technology was not *** STANPT scheme was the least efficient among the 8 *** schemes using MOET technology had a higher polygenetic response than others in the 17th *** increases of frequency of the favorable QTL allele varied more greatly across t

关键词： dairy cattle marker-assisted selection two-stage selection MOET QTL

A study on the allocation of productive factors of Chinese agriculture

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Journal of Geographical Sciences 2000年第1期10卷 59-65页

作者： LIU Yan-li (Institute of Rural Development, china agricultural university, beijing 100094, china) 中国农业大学北京

Chinese agriculture is undergoing a transformation process from traditional agriculture into modern *** article discusses how land. labor, fertilizer, machinery etc. are used in agricultural production of different regions. reveals the influence of natural conditions and economic level on the utilization of modern agricultural factors. It proposes a system of allocation hoes of regional agricultural productive factors and points out the development stage and tendency of allocation of agricultural productive factors in different regions.

关键词： agricultural productive factor, innovative productive factor,traditional allocation technological allocation