336 research outputs found

    Responses of greenhouse-gas emissions to land-use change from rice to jasmine production in subtropical China

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    We studied the impacts of an increasingly common change in land use from paddy field to jasmine fields on the emission of greenhouse gases (GHGs), which have supposed the transformation of more than 1200 ha only in the last decade in the surroundings of Fuzhou city in response to economic changes. The possible increases that this can suppose constitutes and environmental concern in China. We studied areas dedicated to rice crop that have been partially converted to jasmine cultivation with some parts still kept as rice fields. Emissions of CO2, CH4 and N2O varied significantly among the seasons. CO2 and CH4 cumulative emissions and the global-warming potential (GWP) of these emissions were significantly lower in the jasmine than the paddy field. N2O emission, N2O cumulative emission, however, were higher in the jasmine than the paddy field, despite in some concrete studied periods the differences were not statistically significant. The total decrease in GHG emissions from the conversion from rice to jasmine production was strongly influenced by the indirect effects of various changes in soil conditions. The expected changes due to the great differences in water and fertilization use and management and organic matter input to soil between these two crops were in great part due to modified soil traits. According to structural equation models, the strong direct effects of the change from rice to Jasmine crop reducing the emissions of CO2 and N2O were partially decreased by the indirect effects of crop type change decreasing soil pH and soil [Fe2+] for CO2 emissions and by decreasing soil salinity and soil [Fe3+] for N2O emissions. The negative effects of the crop conversion on CH4 emissions were mostly due to the globally negative indirect effects on soil conditions, by decreases in soil salinity, water content and [Fe2+]. Soil salinity, water content, pH, [Fe2+], [Fe3+] and [total Fe] were significantly lower in the jasmine than the paddy field, but temperature had the opposite pattern. CO2 emissions were generally correlated positively with salinity, temperature, and water content and negatively with [Fe3+] and [total Fe] in both fields. CH4 emissions were positively correlated with salinity, temperature, water content and pH in both fields. N2O emissions were positively correlated with temperature and were negatively correlated with water content, pH, [Fe2+], [Fe3+] and [total Fe] in both fields. CO2 was the most important GHG for the GWPs, and the total GWP was significantly lower for the jasmine than for the rice cropland field. The change in the land use in this area of paddy fields will decreased the global GHG emission, and the effect on the GWPs was mostly due to changes in soil properties

    Agricultural land use decouples soil nutrient cycles in a subtropical riparian wetland in China

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    Altres ajuts rebuts per a dur a terme el treball: Grant from the National Science Foundation of China (31000209)We examined the impact of human changes in land use on the concentrations and stoichiometric relationships among soil carbon (C), nitrogen (N), phosphorus (P) and potassium (K) in a Phragmites australis riparian wetland (Minjiang River estuary, China). We compared a natural (unaltered) wetland with five altered land uses: intertidal mudflat culture and vegetable, flower, fruit and rice cultivations. All these land uses decreased C, N and K soil concentrations relative to those in the P. australis wetland. The close relationship between total soil C and N concentrations, under all land uses, suggested that N was the most limiting nutrient in these wetlands. The lower N concentrations, despite the use of N fertilizers, indicated the difficulty of avoiding N limitation in the agricultural land. Croplands, except rice cultivation, had lower soil N:P ratios than the original P. australis wetland, consistent with the tendency of favoring species adapted to high rates of growth (low N:P ratio). The release of soil C was less and the soil C:N and C:P ratios higher in the natural P. australis riparian wetland than in the croplands, whereas C storage was more similar. The levels of soil C storage were generally opposite to those of C release, indicating that C release by respiration was the most important factor controlling C storage. Cropland soil management promotes faster nutrient and C cycles and changes in soil nutrient stoichiometry. These impacts can further hinder the regeneration of natural vegetation by nutrient imbalances and increase C-cycling and C emissions

    Antigout Effects of Plantago asiatica

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    The XOD inhibitory effects of Plantaginis Semen, that is, the seeds of P. asiatisca, and its representative four single compounds, acteoside, 1H-indolo-3-carbaldehyde, isoacteoside, and myristic acid, were evaluated by electron transfer signal blocking activities (ETSBA), which is based on the electron transfer signal of XOD enzymatic reaction. The blocking activities were detected using an electrochemical biosensing method. Compared with control, significant effects were observed after the addition of P. asiatica extract, acteoside, and 1H-indolo-3-carbaldehyde (all p<0.05). The IC50 values of the extract and acteoside are 89.14 and 7.55 μg·mL−1, respectively. The IC20 values of the extract, acteoside, and 1H-indolo-3-carbaldehyde are 24.28, 3.88, and 16.16 μg·mL−1, respectively. Due to the relatively lower inhibitory potential of 1H-indolo-3-carbaldehyde, its IC50 was not obtained. In addition, isoacteoside and myristic acid did not show any XOD inhibitory effects. Our data demonstrated that the XOD inhibitory effects of the extract, acteoside, and 1H-indolo-3-carbaldehyde can be accurately evaluated by the ETSBA method. The results from this study indicated that Plantaginis Semen significantly inhibited XOD activities to reduce hyperuricemia and treat gout. The study also proves that measuring the electron transfer signal blocking activities is a simple, sensitive, and accurate method to evaluate the XOD inhibitory effects

    The CTNNBIP1-CLSTN1 fusion transcript regulates human neocortical development

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    Fusion transcripts or RNAs have been found in both disordered and healthy human tissues and cells; however, their physiological functions in the brain development remain unknown. In the analysis of deposited RNA-sequence libraries covering early to middle embryonic stages, we identify 1,055 fusion transcripts present in the developing neocortex. Interestingly, 98 fusion transcripts exhibit distinct expression patterns in various neural progenitors (NPs) or neurons. We focus on CTNNBIP1-CLSTN1 (CTCL), which is enriched in outer radial glial cells that contribute to cortex expansion during human evolution. Intriguingly, downregulation of CTCL in cultured human cerebral organoids causes marked reduction in NPs and precocious neuronal differentiation, leading to impairment of organoid growth. Furthermore, the expression of CTCL fine-tunes Wnt/β-catenin signaling that controls cortex patterning. Together, this work provides evidence indicating important roles of fusion transcript in human brain development and evolution

    Electric-field-driven Non-volatile Multi-state Switching of Individual Skyrmions in a Multiferroic Heterostructure

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    Electrical manipulation of skyrmions attracts considerable attention for its rich physics and promising applications. To date, such a manipulation is realized mainly via spin-polarized current based on spin-transfer torque or spin-orbital torque effect. However, this scheme is energy-consuming and may produce massive Joule heating. To reduce energy dissipation and risk of heightened temperatures of skyrmion-based devices, an effective solution is to use electric field instead of current as stimulus. Here, we realize an electric-field manipulation of skyrmions in a nanostructured ferromagnetic/ferroelectrical heterostructure at room temperature via an inverse magneto-mechanical effect. Intriguingly, such a manipulation is non-volatile and exhibits a multi-state feature. Numerical simulations indicate that the electric-field manipulation of skyrmions originates from strain-mediated modification of effective magnetic anisotropy and Dzyaloshinskii-Moriya interaction. Our results open a direction for constructing low-energy-dissipation, non-volatile, and multi-state skyrmion-based spintronic devices.Comment: Accepted by Nature Communications 11, 3577 (2020
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