Purified mitochondrial ATP synthase has been shown to form Ca2+-activated, large conductance channel activity similar to that of mitochondrial megachannel (MMC) or mitochondrial permeability ...transition pore (mPTP) but the oligomeric state required for channel formation is being debated. We reconstitute purified monomeric ATP synthase from porcine heart mitochondria into small unilamellar vesicles (SUVs) with the lipid composition of mitochondrial inner membrane and analyze its oligomeric state by electron cryomicroscopy. The cryo-EM density map reveals the presence of a single ATP synthase monomer with no density seen for a second molecule tilted at an 86o angle relative to the first. We show that this preparation of SUV-reconstituted ATP synthase monomers, when fused into giant unilamellar vesicles (GUVs), forms voltage-gated and Ca2+-activated channels with the key features of mPTP. Based on our findings we conclude that the ATP synthase monomer is sufficient, and dimer formation is not required, for mPTP activity.
Given the threat of environmental degradation and land deterioration to conventional agriculture, modern greenhouse cultivation has attracted increasing attention as an effective alternative. ...However, the high energy consumption of greenhouse systems is concerning given the need to limit the environmental impact of human activities. The solar integration to agricultural greenhouse in the form of modern solar greenhouse has the potential to simultaneously respond to the declining availability of suitable land and the imperative for minimum emissions. In this review, an overview of China's progress towards the development of modern solar greenhouses, as well as the attempts to mitigate the effects of heat loss, shadowing, and poor light condition is presented. A promising prospect is shown by China's modern solar greenhouses at present levels of performances and costs exemplified by the photovoltaic (PV) greenhouses with a practicable payback period of less than 9 years. Additionally, application of advanced solar technology for better thermal storage, PV power generating and light utilization balance has been proved effective to further promote solar energy utilization in modern solar greenhouses.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Biodegradable poly(lactide)/poly(butylene adipate-co-terephthalate) (PLA/PBAT) blends were prepared by reactive blending in the presence of chain-extenders. Two chain-extenders with multi-epoxy ...groups were studied. The effect of chain-extenders on the morphology, mechanical properties, thermal behavior, and hydrolytic degradation of the blends was investigated. The compatibility between the PLA and PBAT was significantly improved by in situ formation of PLA-co-PBAT copolymers in the presence of the chain-extenders, results in an enhanced ductility of the blends, e.g., the elongation at break was increased to 500% without any decrease in the tensile strength. The differential scanning calorimeter (DSC) results reveal that cold crystallization of PLA was enhanced due to heterogeneous nucleation effect of the in situ compatibilized PBAT domains. As known before, PLA is sensitive to hydrolysis and in the presence of PBAT and the chain-extenders, the hydrolytic degradation of the blend was evident. A three-stage hydrolysis mechanism for the system is proposed based on a study of weight loss and molecular weight reduction of the samples and the pH variation of the degradation medium.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
•A detailed simulation model of 5 MW wind turbine is established for the calculation of gear stress.•The tooth surface contact fatigue strength of specific gear sample is obtained by gear contact ...fatigue test.•The reliability model of series system considering the statistical dependence is established.•The advantage of the proposed reliability model is demonstrated by comparing with the traditional model.
Wind energy is the inexhaustible renewable energy source, and the number of wind power utilization in many countries is also growing rapidly. Wind turbine works in harsh natural environment, and long-term random wind load will cause tremendous damage on the internal gear transmission system. In order to accurately predict the fatigue reliability for a 5 MW large-scale wind power gear transmission system in service, a detailed system simulation model is established, and the accurate stress calculation is carried out for the contact fatigue failure mode on tooth surface. In this paper, the linear relationship between the input torque of gear system and the maximum contact stress of each gear is established, and the load history conversion between the input torque and the contact stress can be realized. Then the Miner cumulative damage theory is used to transform the complex random stress history into equivalent constant amplitude cyclic stress, which is load input variable for the reliability prediction model. At the same time, a contact fatigue test for tooth surface is carried out, and P-S-N curves of the gear samples with specific parameters are obtained, which is the strength input variable for the reliability prediction model. In order to reflect the uncertainty effect of service load on the reliability of gear transmission system, the randomness of load history is expressed complementarily at macro level and micro level, respectively. The traditional stress and strength interference theory is extended, and the reliability model of series system considering the statistical dependence among part failures is established. Finally, the advantage of the proposed model is demonstrated by comparing the prediction result of the new model with that of the traditional model.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Acer rubrum L. (red maple) is a popular tree with attractive colored leaves, strong physiological adaptability, and a high ornamental value. Changes in leaf color can be an adaptive response to ...changes in environmental factors, and also a stress response to external disturbances. In this study, we evaluated the effect of girdling on the color expression of A. rubrum leaves. We studied the phenotypic characteristics, physiological and biochemical characteristics, and the transcriptomic and metabolomic profiles of leaves on girdled and non-girdled branches of A. rubrum. Phenotypic studies showed that girdling resulted in earlier formation of red leaves, and a more intense red color in the leaves. Compared with the control branches, the girdled branches produced leaves with significantly different color parameters a*. Physiological and biochemical studies showed that girdling of branches resulted in uneven accumulation of chlorophyll, carotenoids, anthocyanins, and other pigments in leaves above the band. In the transcriptomic and metabolomic analyses, 28,432 unigenes including 1095 up-regulated genes and 708 down-regulated genes were identified, and the differentially expressed genes were mapped to various KEGG (kyoto encyclopedia of genes and genomes) pathways. Six genes encoding key transcription factors related to anthocyanin metabolism were among differentially expressed genes between leaves on girdled and non-girdled branches. Girdling significantly affected the growth and photosynthesis of red maple, and affected the metabolic pathways, biosynthesis of secondary metabolites, and carbon metabolisms in the leaves. This resulted in pigment accumulation in the leaves above the girdling site, leading to marked red color expression in those leaves. A transcriptome analysis revealed six genes encoding anthocyanin-related transcription factors that were up-regulated in the leaves above the girdling site. These transcription factors are known to be involved in the regulation of phenylpropanoid biosynthesis, anthocyanin biosynthesis, and flavonoid biosynthesis. These results suggest that leaf reddening is a complex environmental adaptation strategy to maintain normal metabolism in response to environmental changes. Overall, the results of these comprehensive phenotype, physiological, biochemical, transcriptomic, and metabolomic analyses provide a deeper and more reliable understanding of the coevolution of red maple leaves in response to environmental changes.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The Homegarden (HG) in Chengdu Plain is an important agricultural heritage in China, and is viewed as a sustainable land use pattern. HGs are damaged continuously under the backdrop of urbanization ...and land use changes, thus influencing ecosystem services and residents’ welfare. This study investigates the distribution characteristics of HGs in Chengdu and their ecosystem service value and proposes HG protection strategies on this basis. Results demonstrate that (1) there are 71,892 HGs in Chengdu, covering an area of 558.70 km2. The average density is 9.94 HGs/km2. (2) The total ecosystem service value of HGs is about USD 30562.70 million/year. Among them, the material product, regulating services, biodiversity maintenance value, and cultural services account for 15.46%, 37.90%, 14.19%, and 32.45%, respectively. (3) The number, area, and ecosystem service value of HGs in Chengdu decreased by 11.45%, 20.89%, and 6.92% in the last ten years, respectively. (4) The area of the extremely important protection zone of HGs accounts for 21.14%. We suggest giving priority attention to these areas. Protection strategies of HGs include, among others, formulating HG protection plans, keeping traditional features, maintaining biodiversity, and increasing the economic income of residents.
Insecticides harm the beneficial organisms, such as predatory spiders, through direct killing or regulation of the development and reproduction. In this study, the bioassay showed that the treatment ...of juvenile hormone (JH) analogue fenoxycarb delayed the moulting of Pardosa pseudoannulata, a dominant predatory spider in paddy fields. In order to figure out the regulatory mechanism of fenoxycarb on the spider development, we systematically analyzed JH biosynthesis in P. pseudoannulata. All genes involved in JH biosynthesis pathway were retrieved from the genome of P. pseudoannulata, except for CYP15A1. The absence of CYP15A1 was in agreement with the identification of methyl farnesoate (MF) rather than JH III in the spider. The delayed moulting and decreased expression of JH biosynthesis-related genes in the MF-applied spiderlings supported that MF was an active JH. Fenoxycarb treatment significantly upregulated the transcriptional level of JH biosynthesis-related genes and consequently delayed the spiderling moulting. In the spider development, ecdysteroid played the opposite role, in contrast to MF, to accelerate the development, as our previous study. Here we found that the treatment of ecdysteroid analogue tebufenozide accelerated P. pseudoannulata spiderling moulting, which resulted from the expressional suppression of ecdysteroid biosynthesis-related genes. In total, the JH and ecdysteroid analogues affected the development of P. pseudoannulata by the expressional regulation of biosynthesis-related genes, which would be helpful for the evaluation of hormone analogue insecticides in environmental safety, and useful for the protection and application of P. pseudoannulate and related spider species.
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•Hormone analogues, fenoxycarb and tebufenozide, affected Pardosa pseudoannulata development.•Fenoxycarb and tebufenozide regulated juvenile hormone (JH) and ecdysteroid biosynthesis, respectively.•Methyl farnesoate was the endogenous JH in P. pseudoannulata due to the absence of CYP15A1.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Nighttime light remote sensing technologies provide methods for studying spatiotemporal changes in urban areas. In this research, we study the changes in the urban zone in Zhejiang Province based on ...NPP/VIIRS nighttime light data. Moreover, we propose a methodology to extract urban zones through a buffer threshold analysis method and apply the standard deviation ellipse, urban scale increment, “dual-core” primacy and urban-scale Gini index to uncover the evolution of urban dynamics in Zhejiang Province. The results show that the highest overall urban area extraction accuracy was 95.9%; the highest Kappa coefficient was 91%. The nighttime light intensity changes observed in most cities in Zhejiang Province reflected three periods: “high-speed growth” from 2012–2014, “low-speed growth” from 2014–2018 and “high-speed growth” from 2019–2020. The growth rates observed during the 2019–2020 “high-speed growth” period exceeded those of the 2012–2014 period. Over nine years, the growth rates of the total nighttime light values in all cities ranged from 40% to 319%. Third-tier cities such as Quzhou and Lishui showed significant increases. Second-tier cities, such as Jinhua, Huzhou and Taizhou, had growth rates over 100%. From 2012–2014, the development rates increased in cities in southern Zhejiang Province, such as in Wenzhou and Taizhou, thus promoting a southward shift in the center of gravity. After 2014, the development rates increased in cities in northern Zhejiang Province, such as Hangzhou, Ningbo and Jiaxing, thus promoting a northward shift in the center of gravity, with the center stabilizing in the Keqiao District-Yuecheng District of Shaoxing. According to the changes observed in the “dual-core” primacy and urban-scale Gini index results derived from 2012 to 2020, the development of cities in Zhejiang Province has become more balanced over the past nine years.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
To improve the power-extraction performance of the Savonius vertical-axis wind turbine (S-VAWT), additional cylinders, which are used to control the fluid flow around the wind turbine blade, were ...introduced into the blade design. In contrast to the traditional numerical method, a mathematical model in the form of a dynamical system was used in this study. A numerical calculation program that could effectively solve the equations of wind-induced rotation of S-VAWT was developed, and combined with the Taguchi experimental method to investigate the influence of additional cylinders on the power-extraction characteristics of the S-VAWT. The results showed that the additional cylinders have a significant impact on the power-extraction performance of the S-VAWT. At 4-m/s wind speed, the average power coefficient of the S-VAWT with additional cylinders is 15% higher than that of the conventional S-VAWT. After construction of the wind turbine prototype and power-extraction tests, the results showed that compared with a conventional S-VAWT, the output power was 29% higher for the S-VAWT with additional cylinders under the same particular conditions.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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