98 research outputs found

    ECOLOGICAL TENSION: BETWEEN MINIMUM AND MAXIMUM CHANGES

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    This article elaborates the conditions as well as four potential modes of the ecological problem: (1) The mode of the absolute minimization of the ecological problem: minimum population plus minimum Gross Domestic Product (GDP), which is characterized by the quantity of destruction being less than the quantity of natural rehabilitation of an ecosystem. This mode is the poorest mode with minimum change. (2) The mode of the relative minimization of the ecological problem: minimum population plus maximization of GDP, which is characterized by the quantity of destruction being less than the quantity of both natural rehabilitation and human rehabilitation of an ecosystem. This mode is the best mode with minimum change. (3) The mode of the relative maximization of the ecological problem: maximization of population plus minimum GDP, which is characterized by the quantity of destruction to the ecosystem not being offset by the quantity of human rehabilitation. An example of this mode is an underdeveloped district with vast population and limited farmland. (4) The mode of the absolute maximization of the ecological problem: maximization of population plus maximization of GDP. This is characterized by the continuous increase of the quantity of destruction beyond the quantity of both natural rehabilitation and human rehabilitation of the ecosystem. Its final outcome is the collapse of the ecosystem and a catastrophe to human beings

    What is the Most Significant Political Legacy of Deng Xiaoping: Thoughts in the 20th Year since Deng Xiaopings Death

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    The policy of reform and opening up is Deng Xiaoping s political legacy of which the most significant part is the fixed term system of cadres on different levels and of different categories especially the fixed term of national leaders stipulated by the Constitution of the People s Republic of China The fixed term system of cadres has played a critical role in the reform and opening up China s rise and the development of China s political system This system under the single-party leadership is a political system that is adapted to China s transition from traditional society to modern society It is also adjustable with the process of modernization Its successful implementation lies in that it is what the Communist Party of China the People s Liberation Army of China and the Chinese people expect Its improvement and optimization rely on enhancing the people s right to speak and influence in the election of cadres i e letting the people decide the cadre

    MiR-574-5p alleviates sepsis-induced acute lung injury by regulating TRAF6/NF-ÎșB pathway

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    Purpose: To investigate the protective effect of miR-574-5p pretreatment against acute lung injury (ALI) induced by sepsis.Methods: A male C57BL/6 mouse model of sepsis-induced ALI was established by cecal ligation and puncture (CLP) and treated with miR-574-5p agomir (intravenous injection, 80 mg/kg per day, 3 days). After that, blood and lung samples were obtained for histopathological observation. Myeloperoxidase (MPO) activity, inflammatory cell infiltration, and cytokine expression were analyzed. The target gene of miR-574-5p was predicted using TargetScan prediction, and verified by luciferase assay and western blot.Results: In sepsis-induced ALI mice model, downregulation of miR-574-5p was observed. Pretreatment of miR-574-5p significantly alleviated ALI by suppressing histological damage, and reducing MPO activity and inflammatory cell infiltration, as well as decreasing cytokine expression. The  underlying mechanism was that miR-574-5p targeted TNF receptor associated factor 6 (TRAF6) and suppressed the downstream NF-ÎșB pathway. Moreover, TRAF6 overexpression reversed the effects of miR-574-5p on ALI.Conclusion: MiR-574-5p pretreatment suppresses inflammatory responses, thus reducing lung injury induced by sepsis in mice, partly via the regulation of TRAF6 and NF-ÎșB pathway. Therefore, this approach can potentially be used for the clinical management of ALI in humans Keywords: Sepsis, Acute lung injury, MiR-574-5p, TRAF6, NF-ÎșB pathwa

    Investigation on chatter stability of thin-walled parts in high-speed milling based on relative transfer functions

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    High-speed milling of thin-walled part is a common application for aerospace industry, automotive, computer hardware and bioengineering industries. Aiming at the small-stiffness frequency response characteristics of thin-walled parts, the dynamic model and critical condition of stability was proposed by the relative transfer functions between cutter subsystem and thin-walled part subsystem in this paper. The stability critical domain was predicted by semi-discretization (SD) method based on the dynamic behavior of the multi-DOF system. It can be shown that the chatter condition in high-speed milling is closely related to both cutter speed and depth of cut, besides cutter geometry, engagement conditions, relative frequency response function, material property of thin-walled part and so on. This conclusion provides a theoretical foundation and reference for the milling mechanism research

    Differences of microscopic seepage mechanisms of water flooding and polymer flooding and prediction models of final oil recovery for conglomerate reservoir

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    The special sedimentary environments of conglomerate reservoir lead to pore structure characteristics of complex modal, and the reservoir seepage system is mainly in the “sparse reticular-non reticular” flow pattern. As a result, the study on microscopic seepage mechanism of water flooding and polymer flooding and their differences becomes the complex part and key to enhance oil recovery. In this paper, the actual core samples from conglomerate reservoir in Karamay oilfield are selected as research objects to explore microscopic seepage mechanisms of water flooding and polymer flooding for hydrophilic rock as well as lipophilic rock by applying the Computed Tomography (CT) scanning technology. After that, the final oil recovery models of conglomerate reservoir are established in two displacement methods based on the influence analysis of oil displacement efficiency. Experimental results show that the seepage mechanisms of water flooding and polymer flooding for hydrophilic rock are all mainly “crawling” displacement along the rock surface while the weak lipophilic rocks are all mainly “inrushing” displacement along pore central. Due to the different seepage mechanisms among the water flooding and the polymer flooding, the residual oil remains in hydrophilic rock after water flooding process is mainly distributed in fine throats and pore interchange. These residual oil are cut into small droplets under the influence of polymer solution with stronger shearing drag effect. Then, those small droplets pass well through narrow throats and move forward along with the polymer solution flow, which makes enhancing oil recovery to be possible. The residual oil in weak lipophilic rock after water flooding mainly distributed on the rock particle surface and formed oil film and fine pore-throat. The polymer solution with stronger shear stress makes these oil films to carry away from particle surface in two ways such as bridge connection and forming oil silk. Because of the essential attributes differences between polymer solution and injection water solution, the impact of Complex Modal Pore Structure (CMPS) on the polymer solution displacement and seepage is much smaller than on water flooding solution. Therefore, for the two types of conglomerate rocks with different wettability, the pore structure is the main controlling factor of water flooding efficiency, while reservoir properties oil saturation, and other factors have smaller influence on flooding efficiency although the polymer flooding efficiency has a good correlation with remaining oil saturation after water flooding. Based on the analysis on oil displacement efficiency factors, the parameters of water flooding index and remaining oil saturation after water flooding are used to establish respectively calculation models of oil recovery in water flooding stage and polymer flooding stage for conglomerate reservoir. These models are able to calculate the oil recovery values of this area controlled by single well control, and further to determine the oil recovery of whole reservoir in different displacement stages by leveraging interpolation simulation methods, thereby providing more accurate geological parameters for the fine design of displacement oil program

    Genomic insights into local adaptation and future climate-induced vulnerability of a keystone forest tree in East Asia

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    Assessment of population vulnerability and adaptive capacity under climate change is crucial for informing conservation strategies. Sang et al. assemble a reference genome for Populus koreana and combine population genomics and modelling to predict spatiotemporal responses to climate change.Rapid global climate change is posing a substantial threat to biodiversity. The assessment of population vulnerability and adaptive capacity under climate change is crucial for informing conservation and mitigation strategies. Here we generate a chromosome-scale genome assembly and re-sequence genomes of 230 individuals collected from 24 populations for Populus koreana, a pioneer and keystone tree species in temperate forests of East Asia. We integrate population genomics and environmental variables to reveal a set of climate-associated single-nucleotide polymorphisms, insertion/deletions and structural variations, especially numerous adaptive non-coding variants distributed across the genome. We incorporate these variants into an environmental modeling scheme to predict a highly spatiotemporal shift of this species in response to future climate change. We further identify the most vulnerable populations that need conservation priority and many candidate genes and variants that may be useful for forest tree breeding with special aims. Our findings highlight the importance of integrating genomic and environmental data to predict adaptive capacity of a key forest to rapid climate change in the future

    Apelin-13 Administration Protects Against LPS-Induced Acute Lung Injury by Inhibiting NF-ÎșB Pathway and NLRP3 Inflammasome Activation

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    Background/Aims: Acute lung injury (ALI) is induced by a variety of external and internal factors and leads to acute progressive respiratory failure. Previous studies have shown that apelin-13 can decrease the acute lung injury induced by LPS, but the specific mechanism is unclear. Therefore, a mouse lung injury model and a cell model were designed to explore the mechanism of how apelin-13 alleviates the acute lung injury caused by LPS. Methods: The effect of apelin-13 on LPS-induced structural damage was determined by H&E staining and by the wet/dry weight ratio. The related inflammatory factors in BALF were examined by ELISA. The apoptotic pathway and the NF-ÎșB and NLRP3 inflammasome pathways were evaluated by using Western blotting and immunofluorescence staining. Results: LPS induced the structural damage and the production of inflammatory cytokines in the lung tissues of mice. These deleterious effects were attenuated by apelin-13 administration. The protective effects of apelin-13 were associated with decreased reactive oxygen species (ROS) formation and the inhibition of the activation of the NF-ÎșB and NLRP3 inflammasome pathways in mice and in Raw264.7 cells. Conclusion: Taken together, these data suggest that apelin-13 administration ameliorates LPS-induced acute lung injury by suppressing ROS formation, as well as by inhibiting the NF-ÎșB pathway and the activation of the NLRP3 inflammasome in the lungs

    Corrigendum to: The TianQin project: current progress on science and technology

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    In the originally published version, this manuscript included an error related to indicating the corresponding author within the author list. This has now been corrected online to reflect the fact that author Jun Luo is the corresponding author of the article
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