31 research outputs found

    Automated Mapping of Ms 7.0 Jiuzhaigou Earthquake (China) Post-Disaster Landslides Based on High-Resolution UAV Imagery

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    The Ms 7.0 Jiuzhaigou earthquake that occurred on 8 August 2017 triggered hundreds of landslides in the Jiuzhaigou valley scenic and historic-interest area in Sichuan, China, causing heavy casualties and serious property losses. Quick and accurate mapping of post-disaster landslide distribution is of paramount importance for earthquake emergency rescue and the analysis of post-seismic landslides distribution characteristics. The automatic identification of landslides is mostly based on medium- and low-resolution satellite-borne optical remote-sensing imageries, and the high-accuracy interpretation of earthquake-triggered landslides still relies on time-consuming manual interpretation. This paper describes a methodology based on the use of 1 m high-resolution unmanned aerial vehicle (UAV) imagery acquired after the earthquake, and proposes a support vector machine (SVM) classification method combining the roads and villages mask from pre-seismic remote sensing imagery to accurately and automatically map the landslide inventory. Compared with the results of manual visual interpretation, the automatic recognition accuracy could reach 99.89%, and the Kappa coefficient was higher than 0.9, suggesting that the proposed method and 1 m high-resolution UAV imagery greatly improved the mapping accuracy of the landslide area. We also analyzed the spatial-distribution characteristics of earthquake-triggered landslides with the influenced factors of altitude, slope gradient, slope aspect, and the nearest faults, which provided important support for the further study of post-disaster landslide distribution characteristics, susceptibility prediction, and risk assessment.This work was funded by the National Key Research and Development Program of China (Project No. 2018YFC1505202), the National Natural Science Foundation of China (41941019), the State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Independent Research Project (SKLGP2020Z012), the project on identification and monitoring of potential geological hazards with remote sensing in Sichuan Province (510201202076888) and the Everest Scientific Project at Chengdu University of Technology (2020ZF114103)

    Macrophage CGI-58 Deficiency Activates ROS-Inflammasome Pathway to Promote Insulin Resistance in Mice

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    SummaryOvernutrition activates a proinflammatory program in macrophages to induce insulin resistance (IR), but its molecular mechanisms remain incompletely understood. Here, we show that saturated fatty acid and lipopolysaccharide, two factors implicated in high-fat diet (HFD)-induced IR, suppress macrophage CGI-58 expression. Macrophage-specific CGI-58 knockout (MaKO) in mice aggravates HFD-induced glucose intolerance and IR, which is associated with augmented systemic/tissue inflammation and proinflammatory activation of adipose tissue macrophages. CGI-58-deficient macrophages exhibit mitochondrial dysfunction due to defective peroxisome proliferator-activated receptor (PPAR)γ signaling. Consequently, they overproduce reactive oxygen species (ROS) to potentiate secretion of proinflammatory cytokines by activating NLRP3 inflammasome. Anti-ROS treatment or NLRP3 silencing prevents CGI-58-deficient macrophages from oversecreting proinflammatory cytokines and from inducing proinflammatory signaling and IR in the cocultured fat slices. Anti-ROS treatment also prevents exacerbation of inflammation and IR in HFD-fed MaKO mice. Our data thus establish CGI-58 as a suppressor of overnutrition-induced NLRP3 inflammasome activation in macrophages

    Investigation of cracks in GaN films grown by combined hydride and metal organic vapor-phase epitaxial method

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    Cracks appeared in GaN epitaxial layers which were grown by a novel method combining metal organic vapor-phase epitaxy (MOCVD) and hydride vapor-phase epitaxy (HVPE) in one chamber. The origin of cracks in a 22-μm thick GaN film was fully investigated by high-resolution X-ray diffraction (XRD), micro-Raman spectra, and scanning electron microscopy (SEM). Many cracks under the surface were first observed by SEM after etching for 10 min. By investigating the cross section of the sample with high-resolution micro-Raman spectra, the distribution of the stress along the depth was determined. From the interface of the film/substrate to the top surface of the film, several turnings were found. A large compressive stress existed at the interface. The stress went down as the detecting area was moved up from the interface to the overlayer, and it was maintained at a large value for a long depth area. Then it went down again, and it finally increased near the top surface. The cross-section of the film was observed after cleaving and etching for 2 min. It was found that the crystal quality of the healed part was nearly the same as the uncracked region. This indicated that cracking occurred in the growth, when the tensile stress accumulated and reached the critical value. Moreover, the cracks would heal because of high lateral growth rate

    The complete chloroplast genome of Chamaesium paradoxum

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    Chamaesium paradoxum H. Wolff is an endemic species naturally distributed in China. The complete chloroplast genome sequence of C. paradoxum was generated by de novo assembly using whole genome next generation sequencing data. The complete chloroplast genome of C. paradoxum is 153,512 bp in length, consisting of a pair of inverted repeats (IRs, 25,987 bp) separated by a large single-copy region (LSC, 84,162 bp) and a small single-copy region (SSC, 17,376 bp). There are 129 genes annotated, including 84 coding genes, 37 transfer RNA genes (tRNA), and eight ribosomal RNA genes (rRNA)

    Depuration and Starvation Regulate Metabolism and Improve Flesh Quality of Yellow Catfish (<i>Pelteobagrus fulvidraco</i>)

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    Fat deposition and off-flavor in the muscle are the main problems affecting flesh quality in aquaculture fish, especially in catfish, leading to low acceptability and reduced market price. Yellow catfish is an important aquaculture fish in China. In this study, 40 days of depuration and starvation treatment were explored to improve the muscle quality of aquaculture yellow catfish. After depuration and starvation, the body weight, condition factor (CF) and mesenteric fat index (MFI) were all significantly decreased 20 days after treatment. The metabolomic profiles in muscle were characterized to analyze the muscle quality in yellow catfish. The results showed that the content of ADP, AMP, IMP, glutamic acid and taurine were significantly increased between 20 and 40 days post-treatment in the muscle of yellow catfish during the treatment, which was positively associated with the flesh tenderness and quality. In contrast, aldehydes and ketones associated with off-flavors and corticosterone associated with bitter taste were all decreased at 20 days post-treatment. Considering the balance of body weight loss and flesh quality improvement, depuration and starvation for around 20 days is suitable for aquaculture yellow catfish. Our study not only provides an effective method to improve the flesh quality of aquaculture yellow catfish but also reveals the potential mechanism in this process

    Revealing the Morphological Evolution of Krakatau Volcano by Integrating SAR and Optical Remote Sensing Images

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    On 22 December 2018, volcano Anak Krakatau, located in Indonesia, erupted and experienced a major lateral collapse. The triggered tsunami killed at least 437 people by the 13-m-high tide. Traditional optical imagery plays a great role in monitoring volcanic activities, but it is susceptible to cloud and fog interference and has low temporal resolution. Synthetic aperture radar (SAR) imagery can monitor volcanic activities at a high temporal resolution, and it is immune to the influence of clouds. In this paper, we propose an automatic method to accurately extract the volcano boundary from SAR images by combining multi-polarized water enhancement and the Nobuyuki Otsu (OTSU) method. We extract the area change of the volcano in 2018&ndash;2019 from Sentinel-1 images and ALOS-2 imagesThe area change and evolution are verified and analyzed by combing the results from SAR and optical data. The results show that the southeastern part of the volcano expanded significantly after the eruption, and the western part experienced collapse and recovery. The volcano morphology change experienced a slow-fast-slow process in the two years

    High performance Bi₀.₅Na₀.₅TiO₃-BiAlO₃-K₀.₅Na₀.₅NbO₃ lead-free pyroelectric ceramics for thermal detectors

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    Both high pyroelectric properties and good temperature stability of ferroelectric materials are desirable when used for applications in infrared thermal detectors. In this work, we report lead-free ternary 0.97(0.99Bi0.5Na0.5TiO3-0.01BiAlO3)-0.03K0.5Na0.5NbO3 (BNT-BA-KNN) ceramics, which not only exhibits a large pyroelectric coefficient (p ∼ 3.7 × 10-8 C cm-2K-1) and figures of merit (Fi, Fv, and Fd) but also shows excellent thermal stable properties. At room temperature, Fi, Fv, and Fd are determined as high as 1.32 × 10-10 m/V, 2.89 × 10-2 m2/C, and 1.15 × 10-5Pa-1/2 at 1 kHz and 1.32 × 10-10 m/V, 2.70 × 10-2 m2/C, and 1.09 × 10-5Pa-1/2 at 20 Hz, respectively. During the temperature range of RT to 85 °C, the achieved p, Fi, Fv, and Fd do not vary too much. The high depolarization temperature and the undispersed ferroelectric-ergodic relaxor phase transition with a sharp pyroelectric coefficient peak value of ∼400 × 10-8 C cm-2K-1 are suggested to be responsible for this thermal stability, which ensures reliable actual operation. The results reveal the BNT-BA-KNN ceramics as promising lead-free candidates for infrared thermal detector applications.This work was supported by the Chinese Academy of Sciences Research Equipment Development Project (No. YZ201332), the National Natural Science Foundation (NSFC) of China (No. 61475176), the Shanghai International Science and Technology Cooperation Project (Grant No. 13520700700), and the International Partnership Project of Chinese Academy of Science. Zhen Liu also acknowledges the support of the Shanghai Sailing Program (No. 17YF1429700)

    Tissue Pharmacology of Da-Cheng-Qi Decoction in Experimental Acute Pancreatitis in Rats

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    Objectives. The Chinese herbal medicine Da-Cheng-Qi Decoction (DCQD) can ameliorate the severity of acute pancreatitis (AP). However, the potential pharmacological mechanism remains unclear. This study explored the potential effective components and the pharmacokinetic characteristics of DCQD in target tissue in experimental acute pancreatitis in rats. Methods. Acute pancreatitis-like symptoms were first induced in rats and then they were given different doses of DCQD (6 g/kg, 12 g/kg, and 24 g/kg body weight) orally. Tissue drug concentration, tissue pathological score, and inflammatory mediators in pancreas, intestine, and lung tissues of rats were examined after 24 hours, respectively. Results. Major components of DCQD could be found in target tissues and their concentrations increased in conjunction with the intake dose of DCQD. The high-dose compounds showed maximal effect on altering levels of anti-inflammatory (interleukin-4 and interleukin-10) and proinflammatory markers (tumor necrosis factor α and interleukin-6) and ameliorating the pathological damage in target tissues P<0.05. Conclusions. DCQD could alleviate pancreatic, intestinal, and lung injury by altering levels of inflammatory cytokines in AP rats with tissue distribution of its components
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