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Search Results: 1 - 10 of 101874 matches for " ZHOU Jia-Yu "
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A general product of tensors with applications
Jia-Yu Shao
Mathematics , 2012,
Abstract: We define a general product of two $n$-dimensional tensors $\mathbb {A}$ and $\mathbb {B}$ with orders $m\ge 2$ and $k\ge 1$, respectively. This product is a generalization of the usual matrix product, and satisfies the associative law. Using this product, many concepts and known results of tensors can be simply expressed and/or proved, and a number of applications of this product will be given. Using this tensor product and some properties on the resultant of a system of homogeneous equations on $n$ variables, we define the similarity and congruence of tensors (which are also the generalizations of the corresponding relations for matrices), and prove that similar tensors have the same characteristic polynomials. We study two special kinds of similarity: permutational similarity and diagonal similarity, and their applications in the study of the spectra of hypergraphs and nonnegative irreducible tensors. We define the direct product of tensors (in matrix case it is also called the Kronecker product), and give its applications in the study of the spectra of two kinds of the products of hypergraphs. We also give applications of this tensor product in the study of nonnegative tensors, including a characterization of primitive tensors, the upper bounds of primitive degrees and the cyclic indices of some nonnegative irreducible tensors.
Ecological functions of volatiles produced by plant growth-promoting micro-organisms
植物促生微生物挥发性物质的生态功能研究进展

ZHOU Jia-Yu,DAI Chuan-Chao,CHEN Yan,YANG Teng,
周佳宇
,戴传超,陈 晏,杨 腾

中国生态农业学报 , 2013,
Abstract: Various kinds of endophytic and rhizospheric micro-organisms were closely related with various plants. Most of these micro-organisms were potential promoters of plant growth and development as they produced phytohormones that increased available nutrients to plants, controlled plant pathogens, etc. These microbes were collectively defined as plant growth-promoting micro-organisms. Furthermore, volatiles released by these plant growth-promoting micro-organisms were critical for mutual symbiosis of the host plants and plant-associated micro-organisms. Many endophytic and rhizospheric micro-organisms were reported to be capable of producing varieties of volatiles as secondary metabolites. Volatiles produced by plant growth-promoting micro-organisms had many essential ecological functions and the relationships among the functions were often quite complex. Some volatiles produced by plant growth-promoting micro-organisms were capable of promoting growth and development of plants. These volatiles induced systemic resistance in plants such that survival rates of plants in negative conditions improved. Also these compounds altered the constituents and contents of valuable secondary metabolites in plants, which in turn enhanced plants biotic resistance. Finally, some volatiles inhibited growth or reproduction of pathogens or insects and prevented herbivores from grazing on the host plants. Given these functions and several more, these critical metabolites enhanced host plants' competitive advantages over non-host plants. Because of these valuable ecological functions, further research studies needed to be done on beneficial effects of mutual symbiosis of micro-organisms and host plants. Several volatiles produced by plants affected signaling pathways or gene expression of host plants. In summary, studies on volatiles produced by plant growth-promoting micro-organisms enabled us to better understand the complex relationships among plants and micro-organisms. For in-depth research on volatiles produced by plant growth-promoting micro-organisms, this review summarized the results of current studies and discussed further development in this field.
Mechanism of Catalytic Ozonation for the Degradation of Paracetamol by Activated Carbon
活性炭催化臭氧氧化扑热息痛的机制研究

WANG Jia-yu,DAI Qi-zhou,YU Jie,YAN Yi-zhou,CHEN Jian-meng,
王佳裕
,戴启洲,鱼杰,颜亦舟,陈建孟

环境科学 , 2013,
Abstract: The degradation of paracetamol (APAP) in aqueous solution was studied with ozonation integrated with activated carbon (AC). The synergistic effect of ozonation/AC process was explored by comparing the degradation efficiency of APAP in three processes (ozonation alone, activated carbon alone and ozonation integrated with activated carbon). The operational parameters that affected the reaction rate were carefully optimized. Based on the intermediates detected, the possible pathway for catalytic degradation was discussed and the reaction mechanism was also investigated. The results showed that the TOC removal reached 55.11% at 60 min in the AC/O3 system, and was significantly better than the sum of ozonation alone (20.22%) and activated carbon alone (27.39%), showing the great synergistic effect. And the BOD5/COD ratio increased from 0.086 (before reaction) to 0.543 (after reaction), indicating that the biodegradability was also greatly improved. The effects of the initial concentration of APAP, pH value, ozone dosage and AC dosage on the variation of reaction rate were carefully discussed. The catalytic reaction mechanism was different at different pH values: the organic pollutions were removed by adsorption and direct ozone oxidation at acidic pH, and mainly by catalytic ozonation at alkaline pH.
Karyotype Variation and Evolution of Sect. Thea in Guizhou
贵州大树茶的核型变异与进化

Liang Guo-lu,Zhou Cai-qiong,Lin Meng-jia,Chen Jia-yu,Liu Jun-su,
梁国鲁
,周才琼,林蒙嘉,陈家玉,刘君素

中国科学院研究生院学报 , 1994,
Abstract: 本文对贵州大树茶7种1变种11类型的核型进行了分析。结果表明,这些种类均为二倍体2n=30。五室茶Camellia quinquelocularis 2n=30=24m+6sm;四球茶C.tetracocca 2n=30=22m+8sm;大理茶C.taliensis 2n=30=22m+8sm;秃房茶C.gymnogyna 2n=30=22m+6sm+2st与2n=30=20m+8sm+2st;假秃房茶C. gymnogynoides 2n=30=22m+6sm+2st与2n=30=20m+8sm+2st;榕江茶C. jungkiangensis 2n=30+20m+8sm+2st;茶C.sinensis 2n=30=20m+8sm+2st以及变种淡红花茶C.sinensis var.ruolla 2n=30=20m+8sm+2st;均属2A核型。染色体结构变异在茶组植物演化中起了重要作用。所划分的两大类核型,即m和sm类与m,sm,和st类是与其子房室数,即5室和3室相一致的。根据核型的不对称性程度、外部形态及生化分析,探讨了各种类的亲缘关系与系统演化途径,论证了茶组植物的原产地是位于滇、桂、黔毗邻交汇处的云贵高原,探讨了茶组植物的分类学问题。
Hominoid-Specific De Novo Protein-Coding Genes Originating from Long Non-Coding RNAs
Chen Xie equal contributor,Yong E. Zhang equal contributor,Jia-Yu Chen equal contributor,Chu-Jun Liu,Wei-Zhen Zhou,Ying Li,Mao Zhang,Rongli Zhang,Liping Wei ,Chuan-Yun Li
PLOS Genetics , 2012, DOI: 10.1371/journal.pgen.1002942
Abstract: Tinkering with pre-existing genes has long been known as a major way to create new genes. Recently, however, motherless protein-coding genes have been found to have emerged de novo from ancestral non-coding DNAs. How these genes originated is not well addressed to date. Here we identified 24 hominoid-specific de novo protein-coding genes with precise origination timing in vertebrate phylogeny. Strand-specific RNA–Seq analyses were performed in five rhesus macaque tissues (liver, prefrontal cortex, skeletal muscle, adipose, and testis), which were then integrated with public transcriptome data from human, chimpanzee, and rhesus macaque. On the basis of comparing the RNA expression profiles in the three species, we found that most of the hominoid-specific de novo protein-coding genes encoded polyadenylated non-coding RNAs in rhesus macaque or chimpanzee with a similar transcript structure and correlated tissue expression profile. According to the rule of parsimony, the majority of these hominoid-specific de novo protein-coding genes appear to have acquired a regulated transcript structure and expression profile before acquiring coding potential. Interestingly, although the expression profile was largely correlated, the coding genes in human often showed higher transcriptional abundance than their non-coding counterparts in rhesus macaque. The major findings we report in this manuscript are robust and insensitive to the parameters used in the identification and analysis of de novo genes. Our results suggest that at least a portion of long non-coding RNAs, especially those with active and regulated transcription, may serve as a birth pool for protein-coding genes, which are then further optimized at the transcriptional level.
The tiny world of microRNAs in the cross hairs of the mammalian eye
Robert M Lavker, Jia-Yu, David G Ryan
Human Genomics , 2009, DOI: 10.1186/1479-7364-3-4-332
Abstract: MiRNAs, more than any other class of regulatory RNA, have drawn the lion's share of attention in recent years. MiRNAs have been found in diverse organisms from both the plant and animal kingdoms[18-22]. Their numbers have increased exponentially since the first descriptive reports of the two founding members of their class, lin-4 and let-7, were published.[23,24] A central online database, the miRNA Registry (http://www.microrna.sanger.ac.uk/sequences), was created in 2004 to accommodate the expanding numbers of newly identified miRNAs.[25] The database incorporated a previously developed system for the acceptance and annotation of newly identified sequences as miRNAs.[26] The miRNA Registry currently lists 5,922 distinct miRNA sequences from the genomes of 58 species.[27] MiRNA genes account for between 1 and 2 per cent of the total gene pool of an organism. Many miRNAs are phylogenetically conserved.[18,21,22,28] For example, 60 per cent of the 533 unique human miRNAs are also found in mice.[27] A smaller but significant number of these miRNAs, such as let-7, are highly conserved across a wider range of species, reflecting important biological functions.[18,20,21,28,29] MiRNAs exhibit as wide a variety of developmental and tissue distribution patterns as we are accustomed to seeing with the more commonly encountered protein-coding mRNAs.[30] Many miRNAs are expressed in[19,31-33] a highly tissue-specific manner. ' It is important to note that those miRNAs that are conserved in sequence across species also show a high degree of similarity in their expression profiles.Of the known mouse or human miRNAs, more than 70 per cent are located in highly organised transcription units.[34] Based on their location in the human genome, miRNAs can be further classified into three categories: (i) exonic miRNAs in non-coding gene transcripts; (ii) intronic miRNAs in non-coding gene transcripts; and (iii) intronic miRNAs in protein-coding gene transcripts. Transcription of miRNA g
A Regional Tourism Development Pattern Based on the WSR
Liu Jia-yu,Kang Hong-fei
Journal of Chongqing Normal University , 2010,
Abstract: The regional tourism development is a huge social systems engineering, and the physical-affair-person (WSR) system methodology is precisely one practiced available tool in solving complex questions. In view of the regional tourism development,this article subdivides the regional tourism development in each link of the physics, the affair, the human manages, and then launches the elaboration separately in its physical research,affair research and human managed research.Thus, we applies the WSR methodology's basic steps into the regional tourism development correspondencely, and forms the application framework map of the regional tourism development based on the WSR. Finally, by fully considering the factors of physics, affair and the human manages,we construct the three dimensional pattern of the regional tourism development based on the WSR. In this pattern, due to a systematic, complete, sub-regional level consideration of all aspects of tourism development, we can we can make the regional tourism development be achievable and acceptable.
Cored Hypergraphs, Power Hypergraphs and Their Laplacian H-Eigenvalues
Shenglong Hu,Liqun Qi,Jia-Yu Shao
Mathematics , 2013,
Abstract: In this paper, we introduce the class of cored hypergraphs and power hypergraphs, and investigate the properties of their Laplacian H-eigenvalues. From an ordinary graph, one may generate a $k$-uniform hypergraph, called the $k$th power hypergraph of that graph. Power hypergraphs are cored hypergraphs, but not vice versa. Hyperstars, hypercycles, hyperpaths are special cases of power hypergraphs, while sunflowers are a subclass of cored hypergraphs, but not power graphs in general. We show that the largest Laplacian H-eigenvalue of an even-uniform cored hypergraph is equal to its largest signless Laplacian H-eigenvalue. Especially, we find out these largest H-eigenvalues for even-uniform sunflowers. Moreover, we show that the largest Laplacian H-eigenvalue of an odd-uniform sunflower, hypercycle and hyperpath is equal to the maximum degree, i.e., 2. We also compute out the H-spectra of the class of hyperstars. When $k$ is odd, the H-spectra of the hypercycle of size 3 and the hyperpath of length 3 are characterized as well.
Some new trace formulas of tensors with applications in spectral hypergraph theory
Jia-Yu Shao,Liqun Qi,Shenglong Hu
Mathematics , 2013,
Abstract: We give some graph theoretical formulas for the trace $Tr_k(\mathbb {T})$ of a tensor $\mathbb {T}$ which do not involve the differential operators and auxiliary matrix. As applications of these trace formulas in the study of the spectra of uniform hypergraphs, we give a characterization (in terms of the traces of the adjacency tensors) of the $k$-uniform hypergraphs whose spectra are $k$-symmetric, thus give an answer to a question raised in [3]. We generalize the results in [3, Theorem 4.2] and [5, Proposition 3.1] about the $k$-symmetry of the spectrum of a $k$-uniform hypergraph, and answer a question in [5] about the relation between the Laplacian and signless Laplacian spectra of a $k$-uniform hypergraph when $k$ is odd. We also give a simplified proof of an expression for $Tr_2(\mathbb {T})$ and discuss the expression for $Tr_3(\mathbb {T})$.
Inter-Allelic Prion Propagation Reveals Conformational Relationships among a Multitude of [PSI] Strains
Jia-Yu Lin,Tzu-Ya Liao,Han-Chung Lee,Chih-Yen King
PLOS Genetics , 2011, DOI: 10.1371/journal.pgen.1002297
Abstract: Immense diversity of prion strains is observed, but its underlying mechanism is less clear. Three [PSI] prion strains—named VH, VK, and VL—were previously isolated in the wild-type yeast genetic background. Here we report the generation and characterization of eight new [PSI] isolates, obtained by propagating the wild-type strains with Sup35 proteins containing single amino-acid alterations. The VH strain splits into two distinct strains when propagated in each of the three genetic backgrounds, harboring respectively single mutations of N21L, R28P, and Gi47 (i.e. insertion of a glycine residue at position 47) on the Sup35 N-terminal prion-forming segment. The six new strains exhibit complex inter-conversion patterns, and one of them continuously mutates into another. However, when they are introduced back into the wild-type background, all 6 strains revert to the VH strain. We obtain two more [PSI] isolates by propagating VK and VL with the Gi47 and N21L backgrounds, respectively. The two isolates do not transmit to other mutant backgrounds but revert to their parental strains in the wild-type background. Our data indicate that a large number of [PSI] strains can be built on three basic Sup35 amyloid structures. It is proposed that the three basic structures differ by chain folding topologies, and sub-strains with the same topology differ in distinct ways by local structural adjustments. This “large number of variations on a small number of basic themes” may also be operative in generating strain diversities in other prion elements. It thus suggests a possible general scheme to classify a multitude of prion strains.
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