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Neuroglobin mutation associated with hypoxia adaptation in Tibet chicken

Progress in Natural science:Materials International 2007年第12期17卷 1419-1424页

作者： Zhang Lifan1. Liu Chong2. Lian Linsheng3, Zhao Chunjiang1. Bao Haigang1.and Wu Changxin1.1. {1. of {1. {2. and technology, China agricultural university, beijing 1.0094, China 2. {1. of Biological {2., China agricultural university, beijing 1.0094, China 3. {1. of {1. {2. and technology, Yunnan agricultural university, Kunming 6502.1. China) college of {1. {2. and technology China Agricultural University Beijing 100094 China college of Biological {1. China Agricultural University Beijing 100094 China college of {1. {2. and technology Yunnan Agricultural University Kunming 650201 China

Globin protein family plays an important role in storing and transporting oxygen. As a newly reported globin, the revealed function of neuroglobin includes binding and storing oxygen as well as facilitating the utilization of oxygen in neuronal cells. In the present study, mutations in exons of chicken Ngb gene were identified with the method of sequencing and created restriction site PCR in Tibet chicken and other four lowland chicken breeds. The mutations of Lys-2.2.(E4)-Asn and Ser-2.79(E4)-Gly were identified in exon 4 of the gene. The Lys-2.2.(E4)-Asn mutation existed only in Tibet chicken and the mutation frequencies increased with increasing altitude. Analysis of the haplotype and diplotype of the two mutations in Tibet chicken populations of different altitudes showed that the frequencies of TG haplotype and TTGG diplotype also increased with increasing altitude, while the reverse tendency was found on GGAA diplotype. Under the hypoxic simulation incubation, the main haplotype was TG in living embryos and GA in dead embryos. The results showed that the Lys-2.2.(E4)-Asn mutation may be a specific mutation associated with hypoxia adaptation in Tibet chicken.

关键词： Tibet chicken neuroglobin hypoxia adaptation Ngb gene mutation.

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Production of porcine cloned transgenic embryos expressing green fluorescent protein by somatic cell nuclear transfer

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science China(Life sciences) 2006年第2期49卷 164-171页

作者： ZHANG Yunhai1. PAN Dengke1.2. SUN Xiuzhu1. SUN Guojie1. WANG Xiaobo1. LIU Xiaohui1. LI Yan1. DAI Yunping1.& LI Ning1.1. State Key Laboratory for Agrobio{1., China {1. {2., beijing 1.0094, China 2. college of animal science and technology, China {1. {2., beijing 1.0094, China State Key Laboratory for Agrobiotechnology China Agricultural University Beijing 100094 China college of {1. {2. technology China Agricultural University Beijing 100094 China

In the present study, nuclear transferred embryos (NTEs) were reconstructed by using pig fetal fibroblasts as donors; in vitro matured oocytes as recipients. The effects of G41. selection on donor cells, duration of IVM of prepubertal gilt oocytes; oxygen tension in IVM of oocytes were investigated. The results were as follows: (i) When G41. selected cells expressing GFP were used as donors, the cleavage rate of NTEs decreased drastically in comparison to NTEs derived from donors without antibiotic selection (47.5% vs. 71.6%, p>0.05). For the blastocyst rate, no significant difference was observed between two groups (1.% vs. 1..4%, p2.h (83.6% vs. 96.7%, p>0.05). However, no statistical difference was observed between NTEs derived from oocytes of 36 h IVM group; NTEs from oocytes of 42.h IVM group in the rates of cleavage (59.3% vs. 73.6%, p1..2., p2. tension; NTEs derived from oocytes matured under higher oxygen tension (2.% O2. in cleavage rate (70.6% vs. 67.1., p1..8% vs. 1.0}3%, p1. selection does not have a significant effect on cleavage rate of NTEs expressing GFP. (ii) Nuclear maturation is greatly improved by prolonging IVM duration from 36 to 42.h, while no significant differences were observed for developmental potential of transgenic embryos. Thus IVM 42.h is the better choice in order to obtain maximum number of MII oocytes as recipients. (iii) Lower oxygen tension; higher oxygen tension in IVM have no significant effect on development of cloned embryos.

关键词： transgenic cloning, GFP, Pig, early development.

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Empirical likelihood confidence regions of the parameters in a partially linear single-index model

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science China Mathematics 2005年第10期48卷 1333-1348页

作者： XUE Liugen~1.& ZHU Lixing~2.1. {1. of Applied {1.s,{2. university of technology,{2. 1.002.,China 2. Department of Mathematics,Hong Kong Baptist university,Hong Kong,China 1. college of Applied {1.s Beijing University of Technology 100022 Beijing China 2. Department of Mathematics Hong Kong Baptist University Hong Kong China

In this paper, a partially linear single-index model is investigated, and three empirical log-likelihood ratio statistics for the unknown parameters in the model are suggested. It is proved that the proposed statistics are asymptotically standard chi-square under some suitable conditions, and hence can be used to construct the confidence regions of the parameters. Our methods can also deal with the confidence region construction for the index in the pure single-index model. A simulation study indicates that, in terms of coverage probabilities and average areas of the confidence regions, the proposed methods perform better than the least-squares method.

关键词： partially linear single-index model, empirical likelihood, confidence region, chi-square distribution, coverage probability.

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The refined theory of deep rectangular beams based on general solutions of elasticity

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science China(Physics,Mechanics & Astronomy) 2006年第3期49卷 291-303页

作者： GAO Yang1.& WANG Minzhong2.1. {1. of {1., China {2. university, beijing 1.0083, China 2. State Key Laboratory for Turbulence and Complex Systems and Department of Mechanics and Engi- neering {1., Peking university, beijing 1.0871. China college of {1. China Agricultural University Beijing 100083 China State Key Laboratory for Turbulence Complex Systems Department of Mechanics Engineering science Peking University Beijing 100871 China

The problem of deducing one-dimensional theory from two-dimensional the- ory for a homogeneous isotropic beam is investigated. Based on elasticity theory, the re- fined theory of rectangular beams is derived by using Papkovich-Neuber solution and Lur’e method without ad hoc assumptions. It is shown that the displacements and stresses of the beam can be represented by the angle of rotation and the deflection of the neutral surface. Based on the refined beam theory, the exact equations for the beam without transverse surface loadings are derived and consist of two governing differential equations: the fourth-order equation and the transcendental equation. The approximate equations for the beam under transverse loadings are derived directly from the refined beam theory and are almost the same as the governing equations of Timoshenko beam theory. In two ex- amples, it is shown that the new theory provides better results than Levinson’s beam the- ory when compared with those obtained from the linear theory of elasticity.

关键词： deep rectangular beams,the refined theory,Papkovich-Neuber solution,Lur'e method,governing equation

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Genetic polymorphisms of milk epithelial mucin of yaks

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Progress in Natural science:Materials International 2006年第11期16卷 1222-1226页

作者： ZHENG Yucai~1, ZHAO Xingbo~2.*, JIN Suyu~1, PENG Xianwen~1 and BAI Wenlin~1 (1. college of Life {1. and {2., Southwest university for Nationalities, Chengdu 610041, China 2. State Key Laboratory for Agrobio{2. and Ministry of Agriculture Key Laboratory of animal Genetics, Breeding and Reproduction, China agricultural university, beijing 1.0094, China) [a]college of Life {1. and {2. Southwest University for Nationalities Chengdu China [b]State Key Laboratory for Agrobiotechnology and Ministry of Agriculture Key Laboratory of {1. Genetics Breeding and Reproduction China Agricultural University Beijing China

Milk epithelial mucin (MUC1. of yaks was separated by SDS-polyacrylamide gel electrophoresis. A total of nine types of MUC1.were revealed in 42. yaks from five yak breeds including Maiwa yak, Jiulong yak, Tianzhu white yak, Qinghai yak and Tibetan yak. The molecular weights of MUC1.are from 1.3 kD to 2.8 kD, most of which are larger than those of bovine. Population genetic analysis shows that the gene frequency and genotype frequency of yak MUC1.differ among breeds, with relatively high gene heterozygosity. The five yak breeds studied fall into two groups according to their milk MUC1.gene frequency, suggesting that milk MUC1.exhibits specificities for local yak groups.

关键词： yak milk genetic polymorphism MUC1.

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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 {1., China {2. university, beijing 1.0083, China 2. Institute of Physics, Chinese Academy of {1.s, beijing 1.0080, China 1. college of {1. 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

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The refined theory of transversely isotropic piezoelectric rectangular beams

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science China(Physics,Mechanics & Astronomy) 2006年第4期49卷 473-486页

作者： GAO Yang1.& WANG Minzhong2.1. {1. of {1., China {2. university, beijing 1.0083, China 2. State Key Laboratory for Turbulence and Complex Systems and Department of Mechanics and Engi- neering {1., Peking university, beijing 1.0871. China 1. college of {1. China Agricultural University Beijing 100083 China 2. State Key Laboratory for Turbulence and Complex Systems and Department of Mechanics and Engineering {1. Peking University Beijing 100871 China

The problem of deducing one-dimensional theory from two-dimensional theory for a transversely isotropic piezoelectric rectangular beam is investigated. Based on the piezoelasticity theory, the refined theory of piezoelectric beams is derived by using the general solution of transversely isotropic piezoelasticity and Lur'e method without ad hoc assumptions. Based on the refined theory of piezoelectric beams, the exact equations for the beams without transverse surface loadings are derived, which consist of two governing differential equations: the fourth-order equation and the transcendental equation. The approximate equations for the beams under transverse loadings are derived directly from the refined beam theory. As a special case, the governing differential equations for transversely isotropic elastic beams are obtained from the corresponding equations of piezoelectric beams. To illustrate the application of the beam theory developed, a uniformly loaded and simply supported piezoelectric beam is examined.

关键词： rectangular beams, the refined theory, piezoelectric, transversely isotropic.

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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 {1., South China {1. {2., Guangzhou 51.642. China 2. Graduate {2. of Chinese Academy of sciences, beijing 1.0049, China 1. Information college South China Agricultural University Guangzhou 510642 China 2. Graduate {1. of Chinese Academy of {1.s 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.

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Polycistronic strategy for cyanobacterial expression vector construction: Co-transcription of a human gene and a selective marker gene

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Progress in Natural science:Materials International 2005年第9期15卷 798-803页

作者： ZHANG Yukun1, SHI Dingji2. ZHAO Feifei1, YU Meimin1 and RU Binggen1(1. college of Life {1., Peking {2., beijing 100871, China 2. college of Marine {1.s & Engineering, Tianjin {2. of {1. & technology, Tianjin 300450, China) college of Life {1. Peking University Beijing 100871 China. college of Marine {1.s & Engineering Tianjin University of Science & Technology Tianjin 300450 China

A polycistronic expression vector, pKGA-NTF1. was constructed for the cyanobacterium. Within this vector, the spectinomycin/streptomycin resistance gene (aadA) facilitated the selection of transformants when co-transcribed with favorite genes. A natural glnA gene was selected as the platform to introduce the plasmid into a neutral site of the Synechococcus sp. PCC 7002.chromosome. Function of the vector was demonstrated by the insertion of a modified human Trefoil factor 3 gene (NTF1. to upstream of the aadA gene and by the analyses of the transformed strains. Antibiotics resistance assays showed that the dicistronic expression cassette conferred high spectinomycin resistance to both the E. coli cells and the Synechococcus cells. PCR analysis and Western-blot analysis were carried out to confirm the integration and expression of the NTF1.gene, respectively. Through simple molecular manipulations, the artificial polycistronic structure described here can be conveniently used to express other favorable genes or operons in cyanobacteria, and to study the cyanobacterial gene expression as well.

关键词： cyanobacterial transformation human Trefoil factor 3 polycistronic expression Synechococcus sp. PCC 7002 vector construction.

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Structure and kinematic analysis of a novel 2.DOF translational parallel robot

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Progress in Natural science:Materials International 2007年第10期17卷 1213-1219页

作者： Chen Tao1. Wu Chao2.and Liu Xinjun2.1. School of Application science and {1., Harbin {2. of science and {1., Harbin 1.0080, China 2. Department of Precision Instruments, Tsinghua {2., beijing 1.0084, China) School of Application science and {1. Harbin University of Science and Technology Harbin 150080 China Department of Precision Instruments Tsinghua University Beijing 100084 China

This paper addresses the analysis of a novel parallel robot with 2.translational degrees of freedom (DOFs). The robot can position a rigid body in a plane with constant orientation. The kinematic structure of the robot is first described in detail. Some kinematic problems, such as the inverse and forward kinematics, velocity, and singularity are then analyzed. The working and assembly modes are discussed. Since it is the most important index to design a robot, the workspace of the robot is studied systematically in this paper. Based on the analysis of reachable workspace and singularity, a kind of workspace concept characterizing the region that the end-effector of the robot can reach in practice is defined. The results of this paper will be very useful for the design and application of the robot.

关键词： parallel robot degree of freedom kinematics workspace.

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