54 research outputs found

    Long-term antagonistic effect of increased precipitation and nitrogen addition on soil respiration in a semiarid steppe

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    Changes in water and nitrogen (N) availability due to climate change and atmospheric N deposition could have significant effects on soil respiration, a major pathway of carbon (C) loss from terrestrial ecosystems. A manipulative experiment simulating increased precipitation and atmospheric N deposition has been conducted for 9 years (2005–2013) in a semiarid grassland in Mongolian Plateau, China. Increased precipitation and N addition interactively affect soil respiration through the 9 years. The interactions demonstrated that N addition weakened the precipitation-induced stimulation of soil respiration, whereas increased precipitation exacerbated the negative impacts of N addition. The main effects of increased precipitation and N addition treatment on soil respiration were 15.8% stimulated and 14.2% suppressed, respectively. Moreover, a declining pattern and 2-year oscillation were observed for soil respiration response to N addition under increased precipitation. The dependence of soil respiration upon gross primary productivity and soil moisture, but not soil temperature, suggests that resources C substrate supply and water availability are more important than temperature in regulating interannual variations of soil C release in semiarid grassland ecosystems. The findings indicate that atmospheric N deposition may have the potential to mitigate soil C loss induced by increased precipitation, and highlight that long-term and multi-factor global change studies are critical for predicting the general patterns of terrestrial C cycling in response to global change in the future

    Influence of climatic variables on maize grain yield and its components by adjusting the sowing date

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    Yield and its components are greatly affected by climate change. Adjusting the sowing date is an effective way to alleviate adverse effects and adapt to climate change. Aiming to determine the optimal sowing date of summer maize and clarify the contribution of climatic variables to grain yield and its components, a consecutive 4-year field experiment was conducted from 2016 to 2019 with four sowing dates at 10-day intervals from 5 June to 5 July. Analysis of historical meteorological data showed that more solar radiation (SR) was distributed from early June to mid-August, and the maximum temperature (Tmax) > 32°C appeared from early July to late August, which advanced and lasted longer in 1991–2020 relative to 1981–1990. Additionally, the precipitation was mainly distributed from early June to late July. The climate change in the growing season of summer maize resulted in optimal sowing dates ranging from 5 June to 15 June, with higher yields and yield stability, mainly because of the higher kernel number per ear and 1,000-grain weight. The average contribution of kernel number per ear to grain yield was 58.7%, higher than that of 1,000-grain weight (41.3%). Variance partitioning analysis showed that SR in 15 days pre-silking to 15 days post-silking (SS) and silking to harvest (SH) stages significantly contributed to grain yield by 63.1% and 86.4%. The extreme growing degree days (EDD) > 32°C, SR, precipitation, and diurnal temperature range (DTR) contributed 20.6%, 22.9%, 14.5%, and 42.0% to kernel number per ear in the SS stage, respectively. Therefore, we concluded that the early sowing dates could gain high yield and yield stability due to the higher SR in the growing season. Meanwhile, due to the decreasing trend in SR and increasing Tmax trend in this region, in the future, new maize varieties with high-temperature resistance, high light efficiency, shade tolerance, and medium-season traits need to be bred to adapt to climate change and increased grain yield

    Diabetes mellitus is associated with elevated urinary pyrrole markers of γ-diketones known to cause axonal neuropathy

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    Introduction Progressive distal symmetrical axonal neuropathy, a complication of diabetes mellitus (DM), has an unknown cause. Normal physiological metabolism and diabetic dysmetabolism are associated with the generation of γ-diketones. γ-Diketones form pyrroles with protein amines, notably with axonal proteins required for the maintenance of nerve fiber integrity, especially elongate, large-diameter peripheral nerve fibers innervating the extremities. We tested the hypothesis that neuropathy-associated γ-diketone pyrroles are elevated in DM.Research design and methods We measured the urinary concentration of γ-diketone pyrroles in age-matched and gender-matched elderly (60–84 years) persons with (n=267) or without (n=267) indicators of DM based in a community population (9411 community older adults aged ≥60 years) in Shenzhen city, Guangdong, China. We used statistical methods, including a generalized linear model, multivariate logistic regression analysis and restricted cubic splines, to assess linear and nonlinear relationships between urinary γ-diketone pyrroles and indicators of DM.Results Compared with healthy controls, those with DM had significantly higher levels of fasting blood glucose, glycated hemoglobin A1c, urinary ketone bodies and urinary γ-diketone pyrroles. The median concentration of urinary γ-diketone pyrrole adducts was significantly higher (p<0.0001) in individuals with DM (7.5 (5.4) μM) compared with healthy controls (5.9 (4.3) μM). Both linear and non-linear relations were found between urinary γ-diketone pyrroles and indicators of DM.Conclusions Diabetic dysmetabolism includes increased generation and excretion of neuropathy-associated γ-diketone pyrroles. These findings form the foundation for studies to test whether γ-diketone pyrrole concentration correlates with quantitative sensory (vibration and temperature) and electrodiagnostic testing

    The Wave of the Digital Economy: The Conflict and Balance between Data Sharing and Personal Privacy

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    As modern society gradually penetrates into the era of big data, digital economy becomes an important field. Citizens’ information data is rapidly passed in the tripartite field of economy, government and individuals, and citizens’ privacy leakage is serious. The article will take Learning Pass leaked information, township bank red code, etc. as examples to study the result and impact of personal privacy leakage, the conflict and balance between digital sharing and personal privacy, how to work together to protect personal privacy, personal privacy related protection policies, etc. Through questionnaire survey, data crawling, and XXXX model, etc. to analyze data, the article will research on the digital economy on personal privacy, and propose protection countermeasures, so that individual citizens can be more vigilant, relevant fields can comply with relevant norms, improve relevant literacy, reduce personal privacy leakage, and make data sharing and personal privacy present a balanced state

    Constitutional Amendments and Myanmar Political Evolution:Trajectory and Orientation

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    林达丰,厦门大学东南亚研究中心/南洋研究院讲师,法学博士 ;范宏伟,厦门大学东南亚研究中心/南洋研究院教授、博士生导师,历史学博士。【中文摘要】缅甸现行宪法于2008年由当时执政的军政府历时十五年起草颁布,该法赋予了军方特殊的政治地位。2011年,缅甸民主化转型之后,缅军只是表面上退出了政治,缅甸进入了军政 “双头政治”的格局。2019年1月,缅甸执政党全国民主联盟启动修宪,试图改变这一局面。然而,这一努力不出意外地在2020年3月遭遇失败。修宪本质是如何处理军人在缅甸政治中的角色与作用问题。军人在缅甸政治中的重要作用,来自尚未完成的民族国家建构困境,有长期、深厚的历史根源。2008年宪法实际也是缅甸独立60年发展史、近半个世纪军人执政历史的逻辑结果和延伸。民盟也充分意识到这一点,主张通过渐进、协商的方式修宪。此次修宪更多是民盟为了应对2020年11月大选的策略,以恢复、强化选民对民盟民主化改革意志的信心和决心,打击和分化军方-巩发阵营。 【Abstract】Myanmar's current constitution was approved in 2008,under which the Tatmadaw retains significant control of the government. In January 2019,the NLD initiated constitutional amendment. It failed unsurprisingly in March 2020. The military's constitutional role has its roots firmly embedded in Myanmar s unfinished nation -building impasse. Thus,the 2008 constitution is an expression of a specific context with historical and cultural implications,which the NLD with its political insights well appreciates. The NLD claims that it will push the constitutional amendment only through negotiations. As a result,it is a pre-campaign maneuver,intended to consolidate its pre-campaign status as democratic transition leader and its popularity over other opposition political groups.教育部人文社科重点研究基地项目“冷战时期中国与东南亚关系编年史” (18JJD770002

    Structural and Functional Insights into the Stealth Protein CpsY of <i>Mycobacterium tuberculosis</i>

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    Mycobacterium tuberculosis (Mtb) is an important and harmful intracellular pathogen that is responsible for the cause of tuberculosis (TB). Mtb capsular polysaccharides can misdirect the host’s immune response pathways, resulting in additional challenges in TB treatment. These capsule polysaccharides are biosynthesized by stealth proteins, including CpsY. The structure and functional mechanism of Mtb CpsY are not completely delineated. Here, we reported the crystal structure of CpsY201−520 at 1.64 Å. CpsY201−520 comprises three β-sheets with five α-helices on one side and three on the other. Four conserved regions (CR1–CR4) are located near and at the base of its catalytic cavity, and three spacer segments (S1–S3) surround the catalytic cavity. Site-directed mutagenesis demonstrated the strict conservation of R419 at CR3 and S1–S3 in regulating the phosphotransferase activity of CpsY201−520. In addition, deletion of S2 or S3 (∆S2 or ∆S3) dramatically increased the activity compared to the wild-type (WT) CpsY201−520. Results from molecular dynamics (MD) simulations showed that S2 and S3 are highly flexible. Our study provides new insights for the development of new vaccines and targeted immunotherapy against Mtb.</i
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