1,716 research outputs found

    Cloning and bioinformatics analysis of an ubiquitin gene of the rice stem borer, Chilo suppressalis Walker (Lepidoptera: Pyralidae)

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    Ubiquitin which has the function of selective protein degradation may play an important role in the regulation of insect growth and development. The coding sequence of an ubiquitin gene from the larvae of the rice stem borer, Chilo suppressalis Walker (Lepidoptera: Pyralidae) named CsUB (GenBank Accession No. GU238420) was cloned by RT-PCR and sequenced in this study, with primers according to the sequences of ubiquitin genes  from Homo sapiens, Drosophila melanogaster and Lepidopteran insects. Sequence analysis showed that the length of the coding sequence is 228 bp, encoding 76 amino acids with calculated molecular weight of 8.50 kDa and the theoretical isoeletric point of 5.26. Signal sequence and transmembrane domain had not been found. Multiple sequence alignment indicated that CsUB gene sequence with other known gene sequences of invertebrates and vertebrates had a high degree of homology (more than 72% similarity) and a shorter genetic distance (lower than 0.360). During the genetic diversity analysis, the total of 104 polymorphic sites was detected from 18 ubiquitin gene sequences and 18 haplotypes were sorted. Abundant genetic diversity and strong codon usage bias were found by the haplotype diversity (1.000), average number of nucleotide differences (47.475), nucleotide diversity (0.20866), effective number of codons (44.526), codon bias index (0.559) and scaled Chi-square (0.779). The predicated secondary structure composition of CsUB protein had about 32.89% extended strands, 36.84% random colis, 15.79% alpha helixes and 14.47% beta turns. Subcellular localization analysis showed that CsUB protein of cytoplasm, cell nucleus, mitochondrion, cell skeleton and plasma membrane occupied about 47.80, 26.10, 17.40, 4.30 and 4.30%, respectively. Sequence, homology and structural analysis confirmed that CsUB gene was highly conserved during evolution and belonged to ubiquitin gene family. The results might provide some fundamental data for further studies on expressed characteristics and physiological functions of CsUB gene.Key words: Chilo suppressalis Walker, ubiquitin, gene cloning, bioinformatics

    Hepcidin and iron homeostasis

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    2003-2004 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Chemical characterization of PM2.5 from a southern coastal city of China:applications of modeling and chemical tracers in demonstrationof regional transport

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    An intensive sampling campaign of airborne fine particles (PM2.5) was conducted at Sanya, a coastal city in Southern China, from January to February 2012. Chemical analyses and mass reconstruction were used identify potential pollution sources and investigate atmospheric reaction mechanisms. A thermodynamic model indicated that low ammonia and high relative humidity caused the aerosols be acidic and that drove heterogeneous reactions which led to the formation of secondary inorganic aerosol. Relationships among neutralization ratios, free acidity, and air-mass trajectories suggest that the atmosphere at Sanya was impacted by both local and regional emissions. Three major transport pathways were identified, and flow from the northeast (from South China) typically brought the most polluted air to Sanya. A case study confirmed strong impact from South China (e.g., Pearl River Delta region) (contributed 76.8% to EC, and then this result can be extended to primary pollutants) when the northeast winds were dominant. The Weather Research Forecasting Black carbon model and trace organic markers were used to apportion local pollution versus regional contributions. Results of the study offer new insights into the atmospheric conditions and air pollution at this coastal city

    Formation of P In defect in annealed liquid-encapsulated Czochralski InP

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    Fourier transform infrared spectroscopy measurements have been carried out on liquid-encapsulated Czochralski-grown undoped InP wafers, which reproducibly become semi-insulating upon annealing in an ambient of phosphorus at 800-900°C. The measurements reveal a high concentration of hydrogen complexes in the form V InH 4 existing in the material before annealing in agreement with recent experimental studies. It is argued that the dominant and essential process producing the semi-insulating behavior is the compensation produced by an EL 2-like deep donor phosphorus antisite defect, which is formed by the dissociation of the hydrogen complexes during the process of annealing. The deep donor compensates acceptors, the majority of which are shallow residual acceptor impurities and deep hydrogen associated V In and isolated V In levels, produced at the first stage of the dissociation of the V InH 4 complex. The high concentration of indium vacancies produced by the dissociation are the precursor of the EL 2-like phosphorus antisite. These results show the importance of hydrogen on the electrical properties of InP and indicate that this largely results from low formation energy of the complex V InH 4 in comparison with that of an isolated V In. © 1998 American Institute of Physics.published_or_final_versio

    Evidence for Anthropogenic Surface Loading as Trigger Mechanism of the 2008 Wenchuan Earthquake

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    Two and a half years prior to China's M7.9 Wenchuan earthquake of May 2008, at least 300 million metric tons of water accumulated with additional seasonal water level changes in the Minjiang River Valley at the eastern margin of the Longmen Shan. This article shows that static surface loading in the Zipingpu water reservoir induced Coulomb failure stresses on the nearby Beichuan thrust fault system at <17km depth. Triggering stresses exceeded levels of daily lunar and solar tides and perturbed a fault area measuring 416+/-96km^2. These stress perturbations, in turn, likely advanced the clock of the mainshock and directed the initial rupture propagation upward towards the reservoir on the "Coulomb-like" Beichuan fault with rate-and-state dependent frictional behavior. Static triggering perturbations produced up to 60 years (0.6%) of equivalent tectonic loading, and show strong correlations to the coseismic slip. Moreover, correlations between clock advancement and coseismic slip, observed during the mainshock beneath the reservoir, are strongest for a longer seismic cycle (10kyr) of M>7 earthquakes. Finally, the daily event rate of the micro-seismicity (M>0.5) correlates well with the static stress perturbations, indicating destabilization.Comment: 22 pages, 4 figures, 3 table

    Phylogeny of the Infraorder Pentatomomorpha Based on Fossil and Extant Morphology, with Description of a New Fossil Family from China

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    <div><h3>Background</h3><p>An extinct new family of Pentatomomorpha, Venicoridae Yao, Ren & Cai <b>fam. nov.</b>, with 2 new genera and 2 new species (<em>Venicoris solaris</em> Yao, Ren & Rider <b>gen. & sp. nov.</b> and <em>Clavaticoris zhengi</em> Yao, Ren & Cai <b>gen. & sp. nov.</b>) are described from the Early Cretaceous Yixian Formation in Northeast China.</p> <h3>Methodology/Principal Findings</h3><p>A cladistic analysis based on a combination of fossil and extant morphological characters clarified the phylogenetic status of the new family and has allowed the reconstruction of intersuperfamily and interfamily relationships within the Infraorder Pentatomomorpha. The fossil record and diversity of Pentatomomorpha during the Mesozoic is discussed.</p> <h3>Conclusions/Significance</h3><p>Pentatomomorpha is a monophyletic group; Aradoidea and the Trichophora are sister groups; these fossils belong to new family, treated as the sister group of remainder of Trichophora; Pentatomoidea is a monophyletic group; Piesmatidae should be separated as a superfamily, Piesmatoidea. Origin time of Pentatomomorpha should be tracked back to the Middle or Early Triassic.</p> </div
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