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Search Results: 1 - 10 of 36991 matches for " Zhiguang Zhao "
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Canonicity and Relativized Canonicity via Pseudo-Correspondence: an Application of ALBA
Willem Conradie,Alessandra Palmigiano,Sumit Sourabh,Zhiguang Zhao
Computer Science , 2015,
Abstract: We generalize Venema's result on the canonicity of the additivity of positive terms, from classical modal logic to a vast class of logics the algebraic semantics of which is given by varieties of normal distributive lattice expansions (normal DLEs), aka `distributive lattices with operators'. We provide two contrasting proofs for this result: the first is along the lines of Venema's pseudo-correspondence argument but using the insights and tools of unified correspondence theory, and in particular the algorithm ALBA; the second closer to the style of J\'onsson. Using insights gleaned from the second proof, we define a suitable enhancement of the algorithm ALBA, which we use prove the canonicity of certain syntactically defined classes of DLE-inequalities (called the meta-inductive inequalities), relative to the structures in which the formulas asserting the additivity of some given terms are valid.
Global Transcriptome Sequencing Using the Illumina Platform and the Development of EST-SSR Markers in Autotetraploid Alfalfa
Zhipeng Liu, Tianlong Chen, Lichao Ma, Zhiguang Zhao, Patrick X. Zhao, Zhibiao Nan, Yanrong Wang
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0083549
Abstract: Background Alfalfa is the most widely cultivated forage legume and one of the most economically valuable crops in the world. The large size and complexity of the alfalfa genome has delayed the development of genomic resources for alfalfa research. Second-generation Illumina transcriptome sequencing is an efficient method for generating a global transcriptome sequence dataset for gene discovery and molecular marker development in alfalfa. Methodology/Principal Findings More than 28 million sequencing reads (5.64 Gb of clean nucleotides) were generated by Illumina paired-end sequencing from 15 different alfalfa tissue samples. In total, 40,433 unigenes with an average length of 803 bp were obtained by de novo assembly. Based on a sequence similarity search of known proteins, a total of 36,684 (90.73%) unigenes were annotated. In addition, 1,649 potential EST-SSRs were identified as potential molecular markers from unigenes with lengths exceeding 1 kb. A total of 100 pairs of PCR primers were randomly selected to validate the assembly quality and develop EST-SSR markers from genomic DNA. Of these primer pairs, 82 were able to amplify sequences in initial screening tests, and 27 primer pairs successfully amplified DNA fragments and detected significant amounts of polymorphism among 10 alfalfa accessions. Conclusions/Significance The present study provided global sequence data for autotetraploid alfalfa and demonstrates the Illumina platform is a fast and effective approach to EST-SSR markers development in alfalfa. The use of these transcriptome datasets will serve as a valuable public information platform to accelerate studies of the alfalfa genome.
Genetic Diversity of Mycobacterium tuberculosis Isolates from Tibetans in Tibet, China
Haiyan Dong, Li Shi, Xiuqin Zhao, Ba Sang, Bing Lv, Zhiguang Liu, Kanglin Wan
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0033904
Abstract: Background Tuberculosis (TB) is a serious health problem in Tibet where Tibetans are the major ethnic group. Although genotyping of Mycobacterium tuberculosis (M. tuberculosis) isolates is a valuable tool for TB control, our knowledge of population structure of M. tuberculosis circulating in Tibet is limited. Methodology/Principal Findings In our study, a total of 576 M. tuberculosis isolates from Tibetans in Tibet, China, were analyzed via spoligotyping and 24-locus MIRU-VNTR. The Beijing genotype was the most prevalent family (90.63%, n = 522). Shared-type (ST) 1 was the most dominant genotype (88.89%, n = 512). We found that there was no association between the Beijing genotype and sex, age and treatment status. In this sample collection, 7 of the 24 MIRU-VNTR loci were highly or moderately discriminative according to their Hunter-Gaston discriminatory index. An informative set of 12 loci had similar discriminatory power with 24 loci set. Conclusions/Significance The population structure of M. tuberculosis isolates in Tibetans is homogeneous and dominated by Beijing genotype. The analysis of 24-locus MIRU-VNTR data might be useful to select appropriate VNTR loci for the genotyping of M. tuberculosis.
Deep-sequencing transcriptome analysis of chilling tolerance mechanisms of a subnival alpine plant, Chorispora bungeana
Zhiguang Zhao, Lingling Tan, Chunyan Dang, Hua Zhang, Qingbai Wu, Lizhe An
BMC Plant Biology , 2012, DOI: 10.1186/1471-2229-12-222
Abstract: Two cDNA libraries constructed from mRNAs of control and chilling-treated seedlings were sequenced by Illumina technology. A total of 54,870 unigenes were obtained by de novo assembly, and 3,484 chilling up-regulated and 4,571 down-regulated unigenes were identified. The expressions of 18 out of top 20 up-regulated unigenes were confirmed by qPCR analysis. Functional network analysis of the up-regulated genes revealed some common biological processes, including cold responses, and molecular functions in C. bungeana and Arabidopsis responding to chilling. Karrikins were found as new plant growth regulators involved in chilling responses of C. bungeana and Arabidopsis. However, genes involved in cold acclimation were enriched in chilling up-regulated genes in Arabidopsis but not in C. bungeana. In addition, although transcription activations were stimulated in both C. bungeana and Arabidopsis, no CBF putative ortholog was up-regulated in C. bungeana while CBF2 and CBF3 were chilling up-regulated in Arabidopsis. On the other hand, up-regulated genes related to protein phosphorylation and auto-ubiquitination processes were over-represented in C. bungeana but not in Arabidopsis.We conducted the first deep-sequencing transcriptome profiling and chilling stress regulatory network analysis of C. bungeana, a subnival alpine plant with inherited cold tolerance. Comparative transcriptome analysis suggests that cold acclimation is not a major chilling tolerance mechanism of C. bungeana. Activation of protein phosphorylation and ubiquitination may confer chilling tolerance to C. bungeana in a more rapid and flexible way than cold acclimation. Such differences may have contributed to the differences in cold tolerance between C. bungeana and Arabidopsis. The results presented in this paper will be informative for gene discovery and the molecular mechanisms related to plant cold tolerance.Chorispora bungeana Fisch. & C.A. Mey (C. bungeana) is a perennial subnival alpine plant that
Bilateral heterochronic spontaneous hemothorax caused by pulmonary arteriovenous malformation in a gravid: A case report
Yinghao Zhao, Guang-Yu Li, Zhiguang Yang, Peng Zhang, Kun Zhang, Guoguang Shao
Journal of Cardiothoracic Surgery , 2010, DOI: 10.1186/1749-8090-5-96
Abstract: Nontraumatic hemothorax is distinctly uncommon: bilateral heterochronic spontaneous hemothorax is rarer. They may result from a variety of causes, and in some patients the cause can remain unknown even after exploratory thoracotomy. We submit a case of bilateral heterochronic spontaneous massive hemothorax as a result of pulmonary ateriovenous malformation that presented during the pregnancy.This is the case of a 34-year-old female who at 22 weeks' gestation was diagnosed with spontaneous hemothorax associated with pulmonary arteriovenous malformation and treated with local resection of the right lower lobe. She presented with sudden onset of right-sided chest pain associated with shortness of breath at the emergency department of her local hospital. The pain continued for two hours without any treatment and she felt gradually increasing heaviness in the chest, which was associated with mild dyspnoea. There was no cough, expectoration, hemoptysis, wheezing, hoarseness of voice or pedal swelling. The patient was 6 months pregnant.Upon examination at our institution, dullness was noted in the right thorax. An urgent electrocardiogram was normal and a routine hemogram showed hemoglobin of 11.2 gm%, with a total leukocyte count of 11500/cmm (80% neutrophils). Bleeding time, clotting time, serum fibrinogen, liver function tests and renal function tests were normal. A follow-up contrast-enhanced and three-dimensional (3-D) computed tomographic scan of the chest (Figure 1, 2) showed a large amount of fluid in the right thorax with mediastinal shift, but with no major vessel injury and 2 small dense opacities in the apical segment of the right lower lobe (diameter = 2.5 cm) and in the posterior aspect of the left lower lobe (diameter = 1.5 cm). In the absence of another cause for spontaneous hemothorax on either clinical or imaging grounds, we determined that these might represent small pulmonary arteriovenous malformations. A pleural aspiration was planned. While waiting f
An Integrated Inventory Model for Vendor and Buyer
Zhiguang Zhang
Modern Applied Science , 2010, DOI: 10.5539/mas.v4n7p197
Abstract: An integrated inventory model for vendor and buyer is presented in this paper. Based on the integrated expected total relevant costs of both buyer and vendor, we obtain the optimal values of reorder point, order quantity, and number of shipments. Numerical example shows the model is effective, and it is also used to analyze the savings in joint total cost over individually derived policies.
Optimal Solutions of Production Inventory Control Problem
Zhiguang Zhang
Modern Applied Science , 2010,
Abstract: This paper studies a production inventory problem, which has deteriorating items and dynamic costs. The corresponding optimal solutions are derived respectively by optimal control theory.
A New Method for Unconstrained Optimization Problem
Zhiguang Zhang
Modern Applied Science , 2010, DOI: 10.5539/mas.v4n10p133
Abstract: This paper presents a new memory gradient method for unconstrained optimization problems. This method makes use of the current and previous multi-step iteration information to generate a new iteration and add the freedom of some parameters. Therefore it is suitable to solve large scale unconstrained optimization problems. The global convergence is proved under some mild conditions. Numerical experiments show the algorithm is efficient in many situations.
Allee effects of local populations and the synchrony of metapopulation
局域种群的Allee效应和集合种群的同步性

LIU Zhiguang,ZHAO Xue,ZHANG Fengpan,CHEN Aimin,
刘志广
,赵雪,张丰盘,陈爱敏

生态学报 , 2012,
Abstract: A metapopulation describes a system of many small and extinction-prone fragmented local populations that are connected via migration. Spatial synchrony of oscillating populations has been observed in many ecological systems, and identifying its causes has attracted the interest of ecologists. Theory has shown that spatially autocorrelated environmental noise, dispersal, and trophic interactions are capable of producing spatial synchrony. Synchrony of a metapopulation has been shown to be detrimental to its persistence because all local populations may go extinct simultaneously. Allee effects at the local population level and Allee-like effects at the metapopulation level are important topics in ecology and conservation. Allee effects result in the existence of a threshold density below which the population goes extinct. At low density, fecundity may decrease while mortality may increase because of a range of factors including difficulties in finding mates, social dysfunction and inbreeding depression. These demographic changes lead to negative population growth rates and ultimately extinction. Many studies have demonstrated the potential importance of Allee effects for the dynamics of small populations, range expansion, community composition and biological invasion. It is widely accepted that Allee effects may increase the extinction risk of low density populations. However, insufficient attention has been paid to the relationship between metapopulation synchrony and Allee effects within local populations. By incorporating detailed information on dispersal strategy in a heterogeneous landscape, we were able to address the following questions: (1) how do Allee effects affect the synchrony of metapopulations? (2) Does the impact of the Allee effect depend on the dispersal strategy? In this paper, we begin by assuming that local populations experience Allee effects and construct a coupled map lattice model of connected local populations, i.e. a metapopulation model. A stability criterion for synchrony involving the Lyapunov number of the local population system, the frequency of dispersal and the network configuration matrix was obtained by Earn et al. We extend these ideas to the situation of a metapopulation comprising local populations subject to Allee effects. Using analysis and simulations, the results suggest that when the intensity of the Allee effect on local populations is strong, the metapopulation goes extinct; (2) when the intensity of the Allee effect on local populations is relatively weak, the local populations fluctuate in synchrony. In this latter case, the metapopulation persists, but the synchronous fluctuations of the local populations cause it to be more susceptible to environmental and demographic stochasticity, which increases metapopulation extinction risk; (3) the connectivity of the network has an important effect on metapopulation synchrony, and fragmented habitat is beneficial for metapopulation survival. Global migration
The biomarkers of 2,6,10,15, 19-pentamethylicosenes and their carbon isotopic composition in the sediments from the Gulf of Mexico
Zhiguang Song,Cuiping Wang
Chinese Science Bulletin , 2006, DOI: 10.1007/s11434-006-2036-x
Abstract: A group of 2,6,10,15,19-pentamethylicosenes (PMIΔ) containing 1–5 unsaturated double bonds has been identified in the sea floor sediments from the Gulf of Mexico at the Green Canyon 238 site. These PMIΔ compounds are distributed between nC22 and nC24 on the mass chromatogram of aliphatic fraction. Their δ 13C values are very much depleted in 13C and in the range of 86.7‰ to 115.5‰, whereas the δ 13C values of companion n-alkanes range from 28.4‰ to 34.6‰ These unsaturated PMIΔ compounds are typical biomarkers derived from the anaerobic oxidation of methane mediated by methane-oxidizing archaeal bacteria and indicative of the gas seeps or even the occurrence of gas hydrates in the deep sea sediments.
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