46 research outputs found

    Mass-induced sea level change in the northwestern North Pacific and its contribution to total sea level change

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    Author Posting. © American Geophysical Union, 2013. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 40 (2013): 3975–3980, doi:10.1002/grl.50748.Over the period 2003–2011, the Gravity Recovery and Climate Experiment (GRACE) satellite pair revealed a remarkable variability in mass-induced sea surface height (MSSH) in the northwestern North Pacific. A significant correlation is found between MSSH and observed total sea surface height (SSH), indicative of the importance of barotropic variability in this region. For the period 2003–2011, MSSH rose at a rate of 6.1 ± 0.7 mm/yr, which has a significant contribution to the SSH rise (8.3 ± 0.7 mm/yr). Analysis of the barotropic vorticity equation based on National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis product, GRACE, and altimetry data suggests that the MSSH signal is primarily caused by negative wind stress curl associated with an anomalous anticyclonic atmospheric circulation. Regression analysis indicates that trends in MSSH and surface wind are related to the Pacific Decadal Oscillation, whose index had a decreasing trend in the last decade.This work was supported by the National Basic Research Program of China (2010CB950303 and 2012CB955603) and the National Natural Science Foundation of China (41176023, 41276108, and 41006006). X.H.C. is also sponsored by “Youth Innovation Promotion Association,” CAS (SQ201204, LTOZZ1202).2014-02-0

    Anatomical variation of mesophyll conductance due to salt stress in Populus cathayana females and males growing under different inorganic nitrogen sources

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    Synergistic regulation in leaf architecture and photosynthesis is essential for salt tolerance. However, how plant sex and inorganic nitrogen sources alter salt stress-dependent photosynthesis remains unknown. Leaf anatomical characteristics and photosynthesis of Populus cathayana Rehder females and males were investigated under salt stress conditions combined with nitrate NO3- and ammonium NH4+ supplies to clarify the underlying mechanisms. In salt-stressed females, we observed an increased mesophyll spongy cell density, a reduced chloroplast density, a decreased surface area of chloroplasts adjacent to the intercellular air space (S-c/S) and an increased mesophyll cell area per transverse section width (S/W), consequently causing mesophyll conductance (g(m)) and photosynthesis inhibition, especially under NH4+ supply. Conversely, males with a greater mesophyll palisade tissue thickness and chloroplast density, but a lower spongy cell density had lower S/W and higher S-c/S, and higher g(m) and photosynthesis. NH4+-fed females had a lower CO2 conductance through cell wall and stromal conductance perpendicular to the cell wall, but a higher chloroplast conductance from the cell wall (g(cyt1)) than females supplied with NO3-, whereas males had a higher chloroplast conductance and lower CO2 conductance through cell wall when supplied with NO3- instead of NH4+ under salt stress. These findings indicate sex-specific strategies in coping with salt stress related to leaf anatomy and g(m) under both types of nitrogen supplies, which may contribute to sex-specific CO2 capture and niche segregation.Peer reviewe

    Optimization of Green and Hardness Protection Technology of Frozen Green Pepper

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    To diminish the browning and tissue softening issues of green pepper dishes in the freezing/thawing processes, salt, trehalose and calcium chloride were used to treat thawed green peppers, and the hardness, drip loss rate, chlorophyll content, sensory evaluation and microstructure of thawed green peppers were measured to verify the effect of process green protection and hard preservation. A single factor experiment was used to screen the optimum range of each factor and response surface methodology was chosen to obtain the optimum process parameter combination. Results showed that the optimum process for protecting green and hardness properties of green pepper was as follows: Blanching green pepper at 100 ℃ for 5 s, the mass fraction of salt in the blanching solution was 0.50%, immersed in cold water for 15 min, the mass fraction of trehalose was 0.51%, and the mass fraction of calcium chloride was 0.25%. Under this process condition, compared with the control group, the color difference of green pepper in the treatment group was reduced by 3.98, the hardness was increased by 20.37%, the juice loss rate was decreased by 40.29%, the chlorophyll content and sensory score were increased by 102.70% and 88%, respectively. Through the scanning electron microscopy, it was found that the treated green pepper cell wall was more complete and maintained a better cell structure. This process can effectively maintain the color and taste of green pepper after thawing, which can provide data support for the research of green and hardness preservation technology of frozen green pepper prefabricated vegetables

    Dimerization of Hepatitis E Virus Capsid Protein E2s Domain Is Essential for Virus–Host Interaction

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    Hepatitis E virus (HEV), a non-enveloped, positive-stranded RNA virus, is transmitted in a faecal-oral manner, and causes acute liver diseases in humans. The HEV capsid is made up of capsomeres consisting of homodimers of a single structural capsid protein forming the virus shell. These dimers are believed to protrude from the viral surface and to interact with host cells to initiate infection. To date, no structural information is available for any of the HEV proteins. Here, we report for the first time the crystal structure of the HEV capsid protein domain E2s, a protruding domain, together with functional studies to illustrate that this domain forms a tight homodimer and that this dimerization is essential for HEV–host interactions. In addition, we also show that the neutralizing antibody recognition site of HEV is located on the E2s domain. Our study will aid in the development of vaccines and, subsequently, specific inhibitors for HEV

    The Potential Role of ORM2 in the Development of Colorectal Cancer

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    Colorectal cancer (CRC) is the third most common malignancy in the world. The risk of death is closely correlated to the stage of CRC at the time of primary diagnosis. Therefore, there is a compelling need for the identification of blood biomarkers that can enable early detection of CRC. We used a quantitative proteomic approach with isobaric labeling (iTRAQ) to examine changes in the plasma proteome of 10 patients with CRC compared to healthy volunteers. Enzyme-Linked Immunosorbnent Assay (ELISA) and Western blot were used for further validation. In our quantitative proteomics analysis, we detected 75 human plasma proteins with more than 95% confidence using iTRAQ labeling in conjunction with microQ-TOF MS. 9 up-regulated and 4 down-regulated proteins were observed in the CRC group. The ORM2 level in plasma was confirmed to be significantly elevated in patients suffering from CRC compared with the controls. ORM2 expression in CRC tissues was significantly increased compared with that in corresponding adjacent normal mucous tissues (P<0.001). ITRAQ together with Q-TOF/MS is a sensitive and reproducible technique of quantitative proteomics. Alteration in expression of ORM2 suggests that ORM2 could be used as a potential biomarker in the diagnosis of CRC

    Responses of Soil Organic Carbon Sequestration Potential and Bacterial Community Structure in Moso Bamboo Plantations to Different Management Strategies in Subtropical China

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    Moso bamboo is one of the fastest-growing plants in the world. The objective of this study was to investigate the impact of converting secondary broadleaf evergreen forests (CK) to Moso bamboo plantations, and the impact of different management strategies, including no disturbance (M0), extensive management (M1), and intensive management (M2), on the soil organic carbon (SOC) sequestration potential, and relevant characteristics of the soil bacterial community. Our results showed that, in comparison with CK, M0 and M1 had significantly higher SOC and recalcitrant organic materials (aliphatic and aromatic compounds), and a lower C mineralization rate, whereas M2 had the opposite effects. The conversion from CK to Moso bamboo plantation significantly decreased the relative abundance of Acidobacteria in both the topsoil and subsoil soil layers. Compared with CK, M0 led to the enrichment of bacteria such as Alphaproteobacteria, Chloroflexi, and Bacteroidetes, which are involved in the decomposition of organic matter and the formation of humus and are, therefore, potentially beneficial for increasing the SOC. Furthermore, the ratio of the microbial biomass C (MBC) to total organic C (TOC), C mineralization rate, and bacterial diversity increased from M0 to M2, i.e., with an increase in the disturbance intensity. These findings indicate that the conversion of secondary broadleaf forest to bamboo forest alter the soil bacterial community structure. Reducing disturbance in bamboo forest management strategies should be actively taken up to improve the SOC, and maintain sustainable development in the forest industry

    Senecavirus A Enhances Its Adaptive Evolution via Synonymous Codon Bias Evolution

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    Synonymous codon bias in the viral genome affects protein translation and gene expression, suggesting that the synonymous codon mutant plays an essential role in influencing virulence and evolution. However, how the recessive mutant form contributes to virus evolvability remains elusive. In this paper, we characterize how the Senecavirus A (SVA), a picornavirus, utilizes synonymous codon mutations to influence its evolution, resulting in the adaptive evolution of the virus to adverse environments. The phylogenetic tree and Median-joining (MJ)-Network of these SVA lineages worldwide were constructed to reveal SVA three-stage genetic development clusters. Furthermore, we analyzed the codon bias of the SVA genome of selected strains and found that SVA could increase the GC content of the third base of some amino acid synonymous codons to enhance the viral RNA adaptive evolution. Our results highlight the impact of recessive mutation of virus codon bias on the evolution of the SVA and uncover a previously underappreciated evolutionary strategy for SVA. They also underline the importance of understanding the genetic evolution of SVA and how SVA adapts to the adverse effects of external stress

    Salicylic acid alleviates the adverse effects of salt stress in Torreya grandis cv. Merrillii seedlings by activating photosynthesis and enhancing antioxidant systems.

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    BACKGROUND: Salt stress is a major factor limiting plant growth and productivity. Salicylic acid (SA) has been shown to ameliorate the adverse effects of environmental stress on plants. To investigate the protective role of SA in ameliorating salt stress on Torreya grandis (T. grandis) trees, a pot experiment was conducted to analyze the biomass, relative water content (RWC), chlorophyll content, net photosynthesis (Pn), gas exchange parameters, relative leakage conductivity (REC), malondialdehyde (MDA) content, and activities of superoxide dismutase (SOD) and peroxidase (POD) of T. grandis under 0.2% and 0.4% NaCl conditions with and without SA. METHODOLOGY/PRINCIPAL FINDINGS: The exposure of T. grandis seedlings to salt conditions resulted in reduced growth rates, which were associated with decreases in RWC and Pn and increases in REC and MDA content. The foliar application of SA effectively increased the chlorophyll (chl (a+b)) content, RWC, net CO2 assimilation rates (Pn), and proline content, enhanced the activities of SOD, CAT and POD, and minimized the increases in the REC and MDA content. These changes increased the capacity of T. grandis in acclimating to salt stress and thus increased the shoot and root dry matter. However, when the plants were under 0% and 0.2% NaCl stress, the dry mass of the shoots and roots did not differ significantly between SA-treated plants and control plants. CONCLUSIONS: SA induced the salt tolerance and increased the biomass of T. grandis cv. by enhancing the chlorophyll content and activity of antioxidative enzymes, activating the photosynthetic process, and alleviating membrane injury. A better understanding about the effect of salt stress in T. grandis is vital, in order gain knowledge over expanding the plantations to various regions and also for the recovery of T. grandis species in the future
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