•Spatio-temporal ecological vulnerabilities across the Qinghai-Tibetan Plateau.•An automatic and objective framework for ecological vulnerability assessment.•The vulnerability in Tibet significantly ...increased and that in Qinghai decreased.•Green vegetation is the dominant driver for ecological vulnerability.•Environmental protection projects are helpful in reducing ecological vulnerability.
The Qinghai-Tibetan Plateau (QTP) has the most fragile ecosystems in the world. Over the past decades, QTP is suffering from increasing external pressures of climate change, human activities, and natural hazards, thus ecological vulnerability assessment is crucial for its sustainable development. This study proposes an objective and automatic framework to assess the ecological vulnerability in the QTP under the threats of mountain hazards, ecosystem degradation and human economic activities and then analyze its spatio-temporal patterns from 2000 to 2015. An ecological vulnerability index (EVI) is established by integrating natural and anthropic factors based on sub-systems of land resources, hydro-meteorology, topography, and social economics. Seventeen indicators are selected to reflect ecological conditions and their weights are determined by principle component analysis and entropy weighting methods. Then, the EVI values are automatically categorized into five vulnerability levels of potential, light, moderate, heavy, and very heavy to illustrate their spatio-temporal patterns across the QTP. Results indicated that spatial distributions of EVI across the QTP exhibited similar patterns during the study period at an overall heavy level. Among all the indicators, vegetation was the dominant driver for ecological vulnerability. Based on trend analyses during the study period, approximately 10.43% of the QTP, mainly distributed in Tibet Autonomous Region, experienced significant increase in ecological vulnerability, while 7.38%, mainly distributed in Qinghai Province, experienced significant ecological vulnerability declination. However, more detailed analyses showed that after the implementation of several ecological protection programs, the increasing trend of ecological vulnerability was eased and more regions experienced significantly decreasing vulnerability. This indicated the ecological restoration projects conducted by the government were efficient in reducing ecological vulnerability.
The Global Land Surface Satellite (GLASS) product suite currently contains 12 products, including leaf area index, fraction of absorbed photosynthetically active radiation, fraction of green ...vegetation coverage, gross primary production, broadband albedo, broadband longwave emissivity, downward shortwave radiation and photosynthetically active radiation, land surface temperature, downward and upwelling thermal radiation, all-wave net radiation, and evapotranspiration. These products are generated from the Advanced Very High Resolution Radiometer and Moderate Resolution Imaging Spectroradiometer satellite data. Their unique features include long-term temporal coverage (many from 1981 to the present), high spatial resolutions of the surface radiation products (1 km and 0.05°), spatial continuities without missing pixels, and high quality and accuracy based on extensive validation using in situ measurements and intercomparisons with other existing satellite products. Moreover, the GLASS products are based on robust algorithms that have been published in peer-reviewed literature. Herein, we provide an overview of the algorithm development, product characteristics, and some preliminary applications of these products. We also describe the next steps, such as improving the existing GLASS products, generating more climate data records (CDRs), broadening product dissemination, and fostering their wider utilization. The GLASS products are freely available to the public.
The fundamental understanding of the mechanisms regulating milk protein synthesis is limited. This study aimed to elucidate the metabolic mechanisms of milk production affected by forage quality ...through studying metabolites from four biofluids (rumen fluid, milk, serum, and urine) collected from 16 lactating cows fed alfalfa hay (AH, high-quality, n = 8) and corn stover (CS, low-quality, n = 8) using gas chromatography-time-of-flight/mass spectrometry. The cows fed AH exhibited higher milk yield (P < 0.01), milk protein yield (P = 0.04), and milk efficiency (P < 0.01) than those fed CS. A total of 165, 195, 218, and 156 metabolites were identified in the rumen fluid, milk, serum, and urine, respectively, while 29 metabolites were found in all four biofluids. In addition 55, 8, 28, and 31 metabolites in each biofluid were significantly different (VIP > 1 and P < 0.05) between the AH- and CS-fed animals. These metabolites were involved in glycine, serine, and threonine metabolism; tyrosine metabolism; and phenylalanine metabolism. Further integrated key metabolic pathway analysis showed that the AH-fed cows may have more comprehensive amino acid metabolisms, suggesting that these metabolite-associated pathways may serve as biomarkers for higher milk yield and better milk protein quality.
With a dinuclear zinc-ProPhenol complex as a catalyst, an efficient and novel 3 + 3 annulation of indoline-2-thiones and isatylidene malononitriles has been successfully developed via the Brønsted ...base and Lewis acid cooperative activation model. This practical methodology gives access to a broad range of chiral spiroindoline-3,4'-thiopyrano2,3-
indole derivatives in good yields with excellent levels of enantioselectivities (up to 88% yield and 99% ee).
L-ascorbic acid (Vitamin C) can enhance the meiotic maturation and developmental competence of porcine oocytes, but the underlying molecular mechanism remains obscure. Here we show the role of ...ascorbic acid in regulating epigenetic status of both nucleic acids and chromatin to promote oocyte maturation and development in pigs. Supplementation of 250 μM L-ascorbic acid 2-phosphate sesquimagnesium salt hydrate (AA2P) during in vitro maturation significantly enhanced the nuclear maturation (as indicated by higher rate of first polar body extrusion and increased Bmp15 mRNA level), reduced level of reactive oxygen species, and promoted developmental potency (higher cleavage and blastocyst rates of parthenotes, and decreased Bax and Caspase3 mRNA levels in blastocysts) of pig oocytes. AA2P treatment caused methylation erasure in mature oocytes on nucleic acids (5-methylcytosine (5 mC) and N
-methyladenosine (m
A)) and histones (Histone H3 trimethylations at lysines 27, H3K27me3), but establishment of histone H3 trimethylations at lysines 4 (H3K4me3) and 36 (H3K36me3). During the global methylation reprogramming process, levels of TET2 (mRNA and protein) and Dnmt3b (mRNA) were significantly elevated, but simultaneously DNMT3A (mRNA and protein), and also Hif-1α, Hif-2α, Tet3, Mettl14, Kdm5b and Eed (mRNA) were significantly inhibited. Our findings support that ascorbic acid can reprogram the methylation status of not only DNA and histone, but also RNA, to improve pig oocyte maturation and developmental competence.
Protein design has received much attention in the last decades. With an additional disulfide bond to enhance the protein stability, human A15C neuroglobin (Ngb) is an ideal protein scaffold for heme ...enzyme design. In this study, we rationally converted A15C Ngb into a multifunctional peroxidase by replacing the heme axial His64 with an Asp residue, where Asp64 and the native Lys67 at the heme distal site were proposed to act as an acid–base catalytic couple for H2O2 activation. Kinetic studies showed that the catalytic efficiency of A15C/H64D Ngb was much higher (∼50–80-fold) than that of native dehaloperoxidase, which even exceeds (∼3-fold) that of the most efficient native horseradish peroxidase. Moreover, the dye-decolorizing peroxidase activity was also comparable to that of some native enzymes. Electron paramagnetic resonance, molecular docking, and isothermal titration calorimetry studies provided valuable information for the substrate–protein interactions. Therefore, this study presents the rational design of an efficient multifunctional peroxidase based on Ngb with potential applications such as in bioremediation for environmental sustainability.
Uncertainties are one principal part of any practical problem. Like any application, image processing process has different unknown parts as uncertainties which are derived from different reasons ...like initial digitalization, sampling to noise, special domain, and intensity. This study presents strong image segmentation for the breast cancer mammography images by considering the interval uncertainties. To consider the system uncertainties, interval analysis has been proposed. The main prominence of this method is taking into account errors in independent variables. An unclear method has the element of subjectivity, while the deterministic methods are not applicable in all cases. Besides, this method is always guaranteed to include the exact result, no matter that its upper and lower bounds happen to be overestimated. The principle theory here is to develop the traditional Laplacian of Gaussian filter based on interval analysis to consider the intensity uncertainties. Experimental results are applied on MIAS that is a popular breast cancer database for medical image segmentation. The performance of the system has been compared with Prewitt, LoG and canny filters based on PSNR.
SARS-CoV-2 induced marked lymphopenia in severe patients with COVID-19. However, whether lymphocytes are targets of viral infection is yet to be determined, although SARS-CoV-2 RNA or antigen has ...been identified in T cells from patients. Here, we confirmed that SARS-CoV-2 viral antigen could be detected in patient peripheral blood cells (PBCs) or postmortem lung T cells, and the infectious virus could also be detected from viral antigen-positive PBCs. We next prove that SARS-CoV-2 infects T lymphocytes, preferably activated CD4 + T cells in vitro. Upon infection, viral RNA, subgenomic RNA, viral protein or viral particle can be detected in the T cells. Furthermore, we show that the infection is spike-ACE2/TMPRSS2-independent through using ACE2 knockdown or receptor blocking experiments. Next, we demonstrate that viral antigen-positive T cells from patient undergone pronounced apoptosis. In vitro infection of T cells induced cell death that is likely in mitochondria ROS-HIF-1a-dependent pathways. Finally, we demonstrated that LFA-1, the protein exclusively expresses in multiple leukocytes, is more likely the entry molecule that mediated SARS-CoV-2 infection in T cells, compared to a list of other known receptors. Collectively, this work confirmed a SARS-CoV-2 infection of T cells, in a spike-ACE2-independent manner, which shed novel insights into the underlying mechanisms of SARS-CoV-2-induced lymphopenia in COVID-19 patients.
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