检索结果-南通市图书馆

Constraints on a scalar-tensor theory with an intermediate-range force by binary pulsars

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2011年第11期54卷 2071-2077页

作者： deng xuemei Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 China

Searching for an intermediate-range force has been considerable interests in gravity experiments. In this paper, aiming at a scalartensor theory with an intermediate-range force, we have derived the metric and equations of motion （EOMs） in the first post- Newtonian （1PN） approximation for general matter without specific equation of state and N point masses firstly. Subsequently, the secular periastron precession ω of binary pulsars in harmonic coordinates is given. After that, ω of four binary pulsars data （PSR B1913＋16, PSR B1534＋12, PSR J0737-3039 and PSR B2127＋11C） have been used to constrain the intermediate-range force, namely, the parameters G and λ. α and λ respectively represent the strength of the intermediate-range force coupling and its length scale. The limits from four binary pulsars data are respectively A = （4.95 ±0.02）× 10^8 m and a = （2.30±0.01）× 10^8 if β = 1, where fl is a parameter like standard parametrized post-Newtonian parameter βPPN. When three degrees of freedom （α, λ and β = β - 1 ） in lσ confidence level are considered, it yields α = （4.21 ±0.01）× 10^4, λ= （4.51 ±0.01）× 10^7 m and β = （-3.30 ±0.01）× 10^-3. Through our research on the scalar-tensor theory with the intermediate-range force, it shows that the parameter α is directly related to the parameter γ （α = （1 - γ）/（1 ＋ γ））. Thus, this presents the constraints on 1 - γ by binary pulsars which is about 10^-4 for three degrees of freedom.

关键词： binary pulsars intermediate-range force post-Newtonian approximation

Global Solutions of Shock Reflection by Wedges for the Nonlinear Wave Equation

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2011年第5期32卷 643-668页

作者： xuemei deng Wei XIANG School of Mathematical Sciences Xiamen University Xiamen 361005 Fujian China Corresponding author. School of Mathematical Sciences Fudan University Shanghai 200433 China

When a plane shock hits a wedge head on, it experiences a reflection-diffraction process and then a self-similar reflected shock moves outward as the original shock moves forward in time. In this paper, shock reflection by large-angle wedges for compressible flow modeled by the nonlinear wave equation is studied and a global theory of existence, stability and regularity is established. Moreover, C^0,1 is the optimal regularity for the solutions across the degenerate sonic boundary.

关键词： Compressible flow Conservation laws Nonlinear wave system Regularreflection

ELLIPTIC EQUATIONS IN DIVERGENCE FORM WITH DISCONTINUOUS COEFFICIENTS IN DOMAINS WITH CORNERS

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2024年第5期44卷 1903-1915页

作者： Jun CHEN xuemei deng Three Gorges Mathematical Research Center China Three Gorges UniversityYichang443002China

We study equations in divergence form with piecewise Cα*** domains contain corners and the discontinuity surfaces are attached to the edges of the *** obtain piecewise C^(1,α) estimates across the discontinuity surf... 详细信息

关键词： elliptic equations divergence form discontinuous coefficients corner regularity

Global classical solution to the three-dimensional isentropic compressible Navier-Stokes equations with general initial data

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2012年第12期55卷 2457-2468页

作者： deng xuemei ZHANG PeiXin ZHAO JunNing School of Mathematical Sciences Xiamen University Xiamen 361005 China College of Science China Three Gorges University Yichang 443002 China School of Mathematical Sciences Huaqiao University Quanzhou 362021 China

We establish the global existence and uniqueness of classical solutions to the Cauchy problem for the isentropic compressible Navier-Stokes equations in the three space dimensions with general initial data which could... 详细信息

关键词： compressible Navier-Stokes equations large viscosity coefficient global classical solutions

Construction of a dual fluorescence whole-cell biosensor to detect N-acyl homoserine lactones

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2014年第2期26卷 415-422页

作者： xuemei deng Guoqiang Zhuang Anzhou Ma Qing Yu Xuliang Zhuang Research Center for Eco-Environmental Sciences Chinese Academy of Sciences

Detection of N-acyl homoserine lactones （AHLs） is useful for understanding quorum sensing （QS） behaviors, including biofilm formation, virulence and metabolism. For detecting AHLs and indicating the host cells in situ, we constructed the plasmid pUCGMA2T1-4 to make a dual fluorescent whole- cell biosensor based on the AhlI/R AHL system of Pseudomonas syringae pv. syringae B728a. The plasmid contains three components： constitutively expressed enptll：：gfP for indicating host cells, Pahll：：mcherry that produces red fluorescence in response to AHL, and the ahIR gene that encodes an AHL regulatory protein. Meanwhile, two copies of T1-4 （four tandem copies of a transcriptional terminator） were added into the plasmid to reduce background. The results showed that when the plasmid was placed into Escherichia coli, the dual fluorescence whole-cell biosensor was able to respond with red fluorescence within 6 hr to 5 × 10^-8-1 × 10^-5 mol/L of 3OC6-HSL. Bright green fluorescence indicated the host cells. Furthermore, when the plasmid was transferred to wild- type Pseudomonas PhTA125 （an AHL-producing bacterium）, it also showed both green and red fluorescence. This result demonstrates that this plasmid can be used to construct whole-cell indicators that can indicate the AHL response and spatial behaviors of microbes in a mi tal niche

关键词： whole-cell biosensor quorum sensing dual fluorescence gfp mcherry indicator

Molecular cloning and characterization of the endothelin 3 gene in black bone sheep

在线全文

学校读者我要写书评

暂无评论

Journal of Animal Science and Biotechnology 2018年第4期9卷 847-857页

作者： Hesham Y.A.Darwish Yuanyuan Zhang Kai Cui Zu Yang Deping Han Xianggui Dong Huaming Mao Weidong deng xuemei deng National Engineering Laboratory for Animal Breeding and Key Laboratory of Animal Genetics Breeding and Reproduction of the Ministry of AgricultureChina Agricultural University Animal Production Research Institute Agricultural Research Center Ministry of Agriculture and Land Reclamation College of Veterinary Medicine China Agricultural University College of Animal Science and Technology Yunnan Agricultural University

Background: Black bone sheep was first discovered in Yunnan province of China in 1970, with unique black pigmentation on the body and internal organs. Endothelin 3(EDN3) has been known as a key gene causing hyperpigmentation in black bone chicken, the Silky ***: In this study, EDN3 was employed as a candidate gene for regulating black color pigmentation. First,EDN3 was cloned from sheep to obtain the full-length cDNA by using the rapid amplification of cDNA ends(RACE).Genomic EDN3 was screened and a total of thirty predicted single nucleotide polymorphisms(SNPs) were genotyped for allele and genotype frequency analysis in a case-control study involving two black bone sheep populations. Genomic copy number analysis of EDN3 in sheep was conducted to measure the variation in copy number. EDN3 expression levels were observed among the groups in adult liver, lymph node, and kidney tissues, as well as embryo kidney samples. Also, among the tissues of black bone and non-black bone ***: The size of the full-length cDNA was 1,578 bp, which included 426 bp of 5′-untranslated region(5′-UTR),an open reading frame(ORF) of 639 bp encoding a protein of 212 amino acids, and a 3′-UTR of 513 bp. Genotype and allele frequencies of all the discovered SNPs were found insignificantly different in black bone and non-black bone sheep(P > 0.05). Genomic copy number analysis of EDN3 in sheep revealed no significant difference between the two sheep groups. No significant variations were found in the adult liver and kidney embryo samples. However,the expression in lymph node and kidney tissue was significantly higher in black bone sheep than that in non-black bone sheep(P < 0.05). Significant variations in the EDN3 expression levels were observed among the tissues of nonblack bone ***: The findings of the present study indicate that unlike in Silky chickens, EDN3 is not responsible for hyperpigmentation but may play a key functional role in immune and excretory

关键词： Black pigmentation Expression level Sequence analysis SNP

yellow^0,a marker for low body weight in Drosophila melanogaster

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2009年第7期52卷 672-682页

作者： Li XinHai & deng xuemei College of Animal Science and Technology,China Agricultural University,Beijing 100193,China College of Animal Science and Technology China Agricultural University Beijing China

Marker-assisted selection(MAS) is an important modern breeding technique,but it has been found that the effect of the markers for quantitative trait loci(QTL) is inconsistent,leading in some cases to MAS failure and raising doubts about its *** the model organism Drosophila melanogaster was employed to study whether an effective marker could be found and applied to *** crossed the stock carrying the y0 marker(a recessive mutation allele of the yellow gene on the X chromosome) with three other stocks carrying corresponding wild-type markers in an F2 design,and found that the y0 marker was in significant association with low body weight(P<0.001).This association was consistent across different backgrounds and the marker effects in female and male were approximately 0.95 σP(phenotypic standard deviation) and 0.68 σP,*** next introgressed a fragment via the y0 marker into a wild stock background over 20 generations of marker-assisted introgression(MAI),and constructed the introgression stock y0(OR)20 in which body weight decreased by 13% and 7%,in female and male,respectively,compared to the wild stock(P<0.0001).This indicated that there must be a single QTL for low body weight that is tightly linked to the y0 *** then shortened the introgressed fragment to less than 1.5 cM by a deeper MAI using the y0 marker and the white *** narrower fragment also resulted in a similar decrease in body weight to that induced by y0(OR)20,indicating that the QTL for low body weight is located within this less-than-1.5 cM *** characteristics of the y0 marker by PCR amplification and Southern blotting revealed that yellow gene was deficient in the y0 stock,leading to disappearance of melanin from the cuticle and probably influencing the developmental *** above results confirmed the existence of effective QTL markers applicable to MAS breeding schemes,and their potential application in breeding new stocks.

关键词： Drosophila low body weight yellow quantitative trait loci marker-assisted selection introgression

A microarray study of altered gene expression during melanoblasts migration in normal pigmented White Leghorn and hyperpigmented mutant Silky Fowl

在线全文

学校读者我要写书评

暂无评论

Frontiers of Agricultural Science and Engineering 2014年第4期1卷 299-306页

作者： Yulin LI Deping HAN Junying LI Dawn KOLTES xuemei deng Key Laboratory of Animal Genetics and Breeding of the Ministry of Agriculture College of Animal Science and TechnologyChina Agricultural UniversityBeijing 100193China Iowa State University AmesIA 50011USA

Melanoblasts originating from neural crest cells can migrate through the mesenchyme of the developed embryo and give rise to *** the melanocytes that are confined to the integument in other vertebrates,melanocytes in Silky Fowl can reach the ventral regions of the embryos owing to differences in gene expression in the process of melanoblasts *** this study,we used microarray profiling to identify differences in gene expression between White Leghorn and Silky *** expression of 2517 microarray probes(P2)was observed in Silky Fowl compared to White *** filtration by cluster analysis,functional annotation and pathway analysis,eight differentially expressed genes were identified to be closely related to the development of ***,differences in expression of immune genes were also detected between Silky Fowl and White *** differentially expressed genes associated with melanocyte development were verified by q-PCR,and results were highly consistent with the microarray *** genes with significantly altered expression involved in melanoblast migration and development suggested that different microenvironments resulted in the abnormal melanoblast migration in Silky Fowl,although there were no big differences in melanoblast development between these two *** candidate genes discovered in this study are beneficial to understand the molecular mechanism of hyperpigmentation in Silky Fowl.

关键词： Silky Fowl White Leghorn melanoblast migration gene expression

Genome-wide profiling of RNA editing sites in sheep

在线全文

学校读者我要写书评

暂无评论

Journal of Animal Science and Biotechnology 2019年第2期10卷 274-282页

作者： Yuanyuan Zhang Deping Han Xianggui Dong Jiankui Wang Jianfei Chen Yanzhu Yao Hesham Y.A.Darwish Wansheng Liu xuemei deng Key Laboratory of Animal Genetics Breeding and Reproduction of the Ministry of Agriculture&Beijing Key Laboratory of Animal Genetic ImprovementChina Agricultural UniversityBeijing 100193China Department of Animal Science Pennsylvania State UniversityUniversity ParkPA 16802USA.3Animal Production Research InstituteAgricultural Research CenterMinistry of Agriculture and Land ReclamationGiza 12618Egypt.

Background: The widely observed RNA-DNA differences(RDDs) have been found to be due to nucleotide alteration by RNA editing. Canonical RNA editing(i.e., A-to-I and C-to-U editing) mediated by the adenosine deaminases acting on RNA(ADAR) family and apolipoprotein B mRNA editing catalytic polypeptide-like(APOBEC)family during the transcriptional process is considered common and essential for the development of an *** date, an increasing number of RNA editing sites have been reported in human, rodents, and some farm animals;however, genome-wide detection of RNA editing events in sheep has not been reported. The aim of this study was to identify RNA editing events in sheep by comparing the RNA-seq and DNA-seq data from three biological replicates of the kidney and spleen ***: A total of 607 and 994 common edited sites within the three biological replicates were identified in the ovine kidney and spleen, respectively. Many of the RDDs were specific to an individual. The RNA editing-related genes identified in the present study might be evolved for specific biological functions in sheep, such as structural constituent of the cytoskeleton and microtubule-based processes. Furthermore, the edited sites found in the ovine BLCAP and NEIL1 genes are in line with those in previous reports on the porcine and human homologs, suggesting the existence of evolutionarily conserved RNA editing sites and they may play an important role in the structure and function of ***: Our study is the first to investigate RNA editing events in sheep. We screened out 607 and 994 RNA editing sites in three biological replicates of the ovine kidney and spleen and annotated 164 and 247 genes in the kidney and spleen, respectively. The gene function and conservation analysis of these RNA editing-related genes suggest that RNA editing is associated with important gene function in sheep. The putative functionally important RNA editing sites reported in the present study

关键词： DNA resequencing RNA-DNA differences RNA editing RNA-seq Sheep