26 research outputs found

    Computational Analysis of Drought Stress-Associated miRNAs and miRNA Co-Regulation Network in Physcomitrella patens.

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    miRNAs are non-coding small RNAs that involve diverse biological processes. Until now, little is known about their roles in plant drought resistance. Physcomitrella patens is highly tolerant to drought; however, it is not clear about the basic biology of the traits that contribute P. patens this important character. In this work, we discovered 16 drought stress-associated miRNA (DsAmR) families in P. patens through computational analysis. Due to the possible discrepancy of expression periods and tissue distributions between potential DsAmRs and their targeting genes, and the existence of false positive results in computational identification, the prediction results should be examined with further experimental validation. We also constructed an miRNA co-regulation network, and identified two network hubs, miR902a-5p and miR414, which may play important roles in regulating drought-resistance traits. We distributed our results through an online database named ppt-miRBase, which can be accessed at http://bioinfor.cnu.edu.cn/ppt_miRBase/index.php. Our methods in finding DsAmR and miRNA co-regulation network showed a new direction for identifying miRNA functions

    Template Route to Chemically Engineering Cavities at Nanoscale: A Case Study of Zn(OH)2 Template

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    A size-controlled Zn(OH)2 template is used as a case study to explain the chemical strategy that can be executed to chemically engineering various nanoscale cavities. Zn(OH)2 octahedron with 8 vertices and 14 edges is fabricated via a low temperature solution route. The size can be tuned from 1 to 30 μm by changing the reaction conditions. Two methods can be selected for the hollow process without loss of the original shape of Zn(OH)2 template. Ion-replacement reaction is suitable for fabrication of hollow sulfides based on the solubility difference between Zn(OH)2 and products. Controlled chemical deposition is utilized to coat an oxide layer on the surface of Zn(OH)2 template. The abundant hydroxyl groups on Zn(OH)2 afford strong coordination ability with cations and help to the coating of a shell layer. The rudimental Zn(OH)2 core is eliminated with ammonia solution. In addition, ZnO-based heterostructures possessing better chemical or physical properties can also be prepared via this unique templating process. Room-temperature photoluminescence spectra of the heterostructures and hollow structures are also shown to study their optical properties

    Market Making via Reinforcement Learning in China Commodity Market

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    Market makers play an essential role in financial markets. A successful market maker should control inventory and adverse selection risks and provide liquidity to the market. As an important methodology in control problems, Reinforcement Learning enjoys the advantage of data-driven and less rigid assumptions, receiving great attention in the market-making field since 2018. However, although the China Commodity market has the biggest trading volume on agricultural products, nonferrous metals, and some other sectors, the study of applying RL to Market Making in China market is still rare. In this thesis, we try to fill the gap. Our contribution is threefold: We develop the Automatic Trading System and verify the feasibility of applying Reinforcement Learning in the China Commodity market. Also, we probe the agent's behavior by analyzing how it reacts to different environmental conditions

    Incremental Classification Algorithm of Hyperspectral Remote Sensing Images Based on Spectral-spatial Information

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    An incremental classification algorithm INC_SPEC_MP<sub>ext</sub> was proposed for hyperspectral remote sensing images based on spectral and spatial information. The spatial information was extracted by building morphological profiles based on several principle components of hyperspectral image. The morphological profiles were combined together in extended morphological profiles (MP<sub>ext</sub>). Combine spectral and MP<sub>ext</sub> to enrich knowledge and utilize the useful information of unlabeled data at the most extent to optimize the classifier. Pick out high confidence data and add to training set, then retrain the classifier with augmented training set to predict the rest samples. The process was performed iteratively. The proposed algorithm was tested on AVIRIS Indian Pines and Hyperion EO-1 Botswana data, which take on different covers, and experimental results show low classification cost and significant improvements in terms of accuracies and Kappa coefficient under limited training samples compared with the classification results based on spectral, MP<sub>ext</sub> and the combination of sepctral and MP<sub>ext</sub>

    Contribution of Coagulase and Its Regulator SaeRS to Lethality of CA-MRSA 923 Bacteremia

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    Coagulase is a critical factor for distinguishing Staphylococcus aureus and coagulase-negative Staphylococcus. Our previous studies demonstrated that the null mutation of coagulase (coa) or its direct regulator, SaeRS, significantly enhanced the ability of S. aureus (CA-MRSA 923) to survive in human blood in vitro. This led us to further investigate the role of coagulase and its direct regulator, SaeRS, in the pathogenicity of CA-MRSA 923 in bacteremia during infection. In this study, we found that the null mutation of coa significantly decreased the mortality of CA-MRSA 923; moreover, the single null mutation of saeRS and the double deletion of coa/saeRS abolished the virulence of CA-MRSA 923. Moreover, the mice infected with either the saeRS knockout or the coa/saeRS double knockout mutant exhibited fewer histological lesions and less neutrophils infiltration in the infected kidneys compared to those infected with the coa knockout mutant or their parental control. Furthermore, we examined the impact of coa and saeRS on bacterial survival in vitro. The null mutation of coa had no impact on bacterial survival in mice blood, whereas the deletion mutation of saeRS or coa/saeRS significantly enhanced bacterial survival in mice blood. These data indicate that SaeRS plays a key role in the lethality of CA-MRSA 923 bacteremia, and that coagulase is one of the important virulence factors that is regulated by SaeRS and contributes to the pathogenicity of CA–MRSA 923

    rLj-RGD3, a Novel Recombinant Toxin Protein from <i>Lampetra japonica</i>, Protects against Cerebral Reperfusion Injury Following Middle Cerebral Artery Occlusion Involving the Integrin-PI3K/Akt Pathway in Rats

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    <div><p>Background</p><p>The RGD-toxin protein Lj-RGD3 is a naturally occurring 118 amino acid peptide that can be obtained from the salivary gland of the <i>Lampetra japonica</i> fish. This unique peptide contains 3 RGD (Arg-Gly-Asp) motifs in its primary structure. Lj-RGD3 is available in recombinant form (rLj-RGD3) and can be produced in large quantities using DNA recombination techniques. The pharmacology of the three RGD motif-containing peptides has not been studied. This study investigated the protective effects of rLj-RGD3, a novel polypeptide, against ischemia/reperfusion-induced damage to the brain caused by middle cerebral artery occlusion (MCAO) in a rat stroke model. We also explored the mechanism by which rLj-RGD3 acts by measuring protein and mRNA expression levels, with an emphasis on the FAK and integrin-PI3K/Akt anti-apoptosis pathways.</p><p>Methods</p><p>rLj-RGD3 was obtained from the buccal secretions of <i>Lampetra japonica</i> using gene recombination technology. Sprague Dawley (SD) rats were randomly divided into the following seven groups: a sham group; a vehicle-treated (VT) group; 100.0 μg·kg<sup>-1</sup>, 50.0 μg·kg<sup>-1</sup> and 25.0 μg·kg<sup>-1</sup> dose rLj-RGD3 groups; and two positive controls, including 1.5 mg·kg<sup>-1</sup> Edaravone (ED) and 100.0 μg·kg<sup>-1</sup> Eptifibatide (EP). MCAO was induced using a model consisting of 2 h of ischemia and 24 h of reperfusion. Behavioral changes were observed in the normal and operation groups after focal cerebral ischemia/reperfusion was applied. In addition, behavioral scores were evaluated at 4 and 24 h after reperfusion. Brain infarct volumes were determined based on 2,3,5-triphenyltetrazolium chloride (TTC) staining. Pathological changes in brain tissues were observed using hematoxylin and eosin (H&E) staining. Moreover, neuronal apoptosis was detected using terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) assays. We determined the expression levels of focal adhesion kinase (FAK), phosphatidyl inositol 3-kinase (PI3K), protein kinase B (Akt, PKB), caspase-3 and Bcl-2 in the brain using western blot analysis and RT-PCR assays. The research protocol was approved by the Institutional Ethics Committee of Dalian Medical University.</p><p>Results</p><p>The behavioral scores and cerebral infarct volumes of the rLj-RGD3 groups were markedly lower at 4 and 24 h/RF. The rLj-RGD3 protein significantly ameliorated pathological changes in the brain and reduced the number of apoptotic neurons. Furthermore, the FAK and PI3K/Akt pathways were activated. rLj-RGD3 significantly increased the expression of FAK, p-FAK and Bcl-2 proteins. In contrast, caspase-3 expression was inhibited.</p><p>Conclusion/Significance</p><p>We conclude that recombinant <i>Lampetra japonica</i> RGD-peptide (rLj-RGD3) exerts a protective effect against cerebral ischemia/reperfusion injury in the brain. In addition, the mechanism of this protection is associated with the activation of the integrin-PI3K/Akt pathway. These results provide a theoretical foundation and an experimental basis for using RGD peptides as novel drugs for treating ischemic cerebral vascular diseases in addition to promoting the research and development of marine biotechnology drugs.</p></div
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