18 research outputs found

    tracking end-effectors for marker-less 3d human motion estimation in multi-view image sequences

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    We propose to track the end-effectors of human body, and use them as kinematic constraints for reliable marker-less 3D human motion tracking. In the presented approach, we track the end-effectors using particle filtering. The tracked results are then combined with image features for 3D full pose tracking. Experimental results verified that the inclusion of end-effectors' constraints improves the tracking performances. © 2013 Springer-Verlag.We propose to track the end-effectors of human body, and use them as kinematic constraints for reliable marker-less 3D human motion tracking. In the presented approach, we track the end-effectors using particle filtering. The tracked results are then combined with image features for 3D full pose tracking. Experimental results verified that the inclusion of end-effectors' constraints improves the tracking performances. © 2013 Springer-Verlag

    Purification and Characterization of a Dark Red Skin Related Dimeric Polyphenol Oxidase from Huaniu Apples

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    The distinct dark-red skin of Huaniu apples renders them attractive to customers. However, the mechanism that leads to the development of the color of the fruit is unclear. In this study, we found that compared with red Fuji (a bright-red apple cultivar), Huaniu apples had higher contents of (−)-epicatechin (EC), (−)-epigallocatechin (EGC), (−)-gallocatechin gallate (GCG), and procyanidins (PCs) B2 and C1 in the peel, which implies that the polymerization of the flavanols and PCs may be correlated with the dark-red skin of the fruit. Using EC as a substrate, we purified an enzyme from Huaniu peel. We performed protein sequencing and discovered that the enzyme was a polyphenol oxidase (PPO). The molecular weight of the enzyme was approximately 140 kDa, which we estimated by native-PAGE and SDS-PAGE, while it was 61 kDa by urea-SDS-PAGE, from which we discovered that the PPO was a dimer. We observed the lowest Km value for catechol (0.60 mM), and the best substrate was 4-methylcatechol, with a Vmax of 526.32 U mg−1 protein. EC is a suitable natural substrate, with a Km value of 1.17 mM, and 55.27% of the Vmax/Km of 4-methylcatechol. When we used EC as a substrate, the optimum temperature and pH of the PPO were 25 °C and 5.0, respectively. In summary, we purified a dimeric PPO from Huaniu apples that showed high activity to EC, which might catalyze the polymerization of flavanols and PCs and lead to the dark-red color development of the fruit

    Metabolite and Transcriptome Profiles of Proanthocyanidin Biosynthesis in the Development of Litchi Fruit

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    The fruit of Litchi chinensis contains high levels of proanthocyanidins (PAs) in the pericarp. These substances can serve as substrates of laccase-mediated rapid pericarp browning after the fruit is harvested. In this study, we found that the major PAs in litchi pericarp were (−)-epicatechin (EC) and several procyanidins (PCs), primarily PC A2, B2, and B1, and the EC and the PC content decreased with the development of the fruit. RNA-seq analysis showed that 43 early and late structure genes related to flavonoid/PA biosynthesis were expressed in the pericarp, including five ANTHOCYANIDIN REDUCTASE (ANR), two LEUCOANTHOCYANIDIN REDUCTASE (LAR), and two ANTHOCYANIDIN SYNTHASE (ANS) genes functioning in the PA biosynthesis branch of the flavonoid pathway. Among these nine PA biosynthesis-related genes, ANR1a, LAR1/2, and ANS1 were highly positively correlated with changes in the EC/PC content, suggesting that they are the key PA biosynthesis-related genes. Several transcription factor (TF) genes, including MYB, bHLH, WRKY, and AP2 family members, were found to be highly correlated with ANR1a, LAR1/2, and ANS1, and their relevant binding elements were detected in the promoters of these target genes, strongly suggesting that these TF genes may play regulatory roles in PA biosynthesis. In summary, this study identified the candidate key structure and regulatory genes in PA biosynthesis in litchi pericarp, which will assist in understanding the accumulation of high levels of browning-related PA substances in the pericarp

    Effect of dimethylaluminumhydride-derived aluminum oxynitride passivation layer on the interface chemistry and band alignment of HfTiO-InGaAs gate stacks

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    In this letter, the reduction and removal of surface native oxide from as-received InGaAs surface by using dimethylaluminumhydride-derived aluminum oxynitride (AlON) passivation layer prior to HfTiO deposition is proposed to solve Fermi level pinning issue. It has been revealed that complete consumption of native oxides of AsOx and GaOx at the InGaAs surface, but no effect to InOx, has been realized after metalorganic chemical vapor deposition AlON at 300 °C. X-ray photoelectron spectroscopy observations of HfTiO/InGaAs gate stacks demonstrate that introducing AlON layer can suppress the regrowth of native oxide at the interface. In addition, the dependence of the valence band spectra of HfTiO/InGaAs gate stacks on AlON passivation layer has been discussed in detail

    Taraxasterol Inhibits LPS-Induced Inflammatory Response in BV2 Microglia Cells by Activating LXRα

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    Neuroinflammation plays a critical role in the development of neurodegenerative diseases. Taraxasterol, a pentacyclic-triterpene isolated from Taraxacum officinale, has been reported to have anti-inflammatory effect. The aim of this study was to investigate the anti-inflammatory effects and mechanism of taraxasterol in LPS-stimulated BV2 microglia cells. BV2 microglia cells were treated with taraxasterol 12 h before LPS stimulation. The effects of taraxasterol on LPS-induced TNF-α and IL-1β production were detected by ELISA. The effects of taraxasterol on LXRα, ABCA1, TLR4, and NF-κB expression were detected by western blot analysis. The results showed that taraxasterol dose-dependently inhibited LPS-induced TNF-α and IL-1β production and NF-κB activation. Taraxasterol also disrupted the formation of lipid rafts and inhibited translocation of TLR4 into lipid rafts. Furthermore, taraxasterol was found to activate LXRα-ABCA1 signaling pathway which induces cholesterol efflux from cells. In addition, our results showed that the anti-inflammatory effect of taraxasterol was attenuated by transfection with LXRα siRNA. In conclusion, these results suggested that taraxasterol inhibits LPS-induced inflammatory response in BV2 microglia cells by activating LXRα-ABCA1 signaling pathway

    BcXyl, a β-xylosidase Isolated from <i>Brunfelsia Calycina</i> Flowers with Anthocyanin-β-glycosidase Activity

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    Brunfelsia calycina flowers lose anthocyanins rapidly and are therefore well suited for the study of anthocyanin degradation mechanisms, which are unclear in planta. Here, we isolated an anthocyanin-&#946;-glycosidase from B. calycina petals. The MS/MS (Mass Spectrometry) peptide sequencing showed that the enzyme (72 kDa) was a &#946;-xylosidase (BcXyl). The enzyme showed high activity to p-Nitrophenyl-&#946;-d-galactopyranoside (pNPGa) and p-Nitrophenyl-&#946;-d-xylopyranoside (pNPX), while no activity to p-Nitrophenyl-&#946;-d-glucopyranoside (pNPG) or p-Nitrophenyl-&#946;-D-mannopyranoside (pNPM) was seen. The optimum temperature of BcXyl was 40 &#176;C and the optimum pH was 5.0. The enzyme was strongly inhibited by 1 mM D-gluconate and Ag+. HPLC (High Performance Liquid Chromatography) analysis showed that BcXyl catalyzed the degradation of an anthocyanin component of B. calycina, and the release of xylose and galactose due to hydrolysis of glycosidic bonds by BcXyl was detected by GC (Gas Chromatography) /MS. A full-length mRNA sequence (2358 bp) of BcXyl (NCBI No. MK411219) was obtained and the deduced protein sequence shared conserved domains with two anthocyanin-&#946;-glycosidases (Bgln and BadGluc, characterized in fungi). BcXyl, Bgln and BadGluc belong to AB subfamily of Glycoside hydrolase family 3. Similar to BcPrx01, an anthocyanin-degradation-related Peroxidase (POD), BcXyl was dramatically activated at the stage at which the rapid anthocyanin degradation occurred. Taken together, we suggest that BcXyl may be the first anthocyanin-&#946;-glycosidase identified in higher plants

    B Type and Complex A/B Type Epicatechin Trimers Isolated from Litchi pericarp Aqueous Extract Show High Antioxidant and Anticancer Activity

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    Litchi (Litchi chinensis Sonn.) fruit is known for its rich source of phenolics. Litchi pericarp contains high levels of epicatechin that may form oligomers of various lengths. Except for several A or B type epicatechin dimers, other soluble oligomers have rarely been identified in the pericarp. Here, bioassay-guided column fractionation was applied to isolate bioactive phenolics from aqueous pericarp extract. A fraction (S3) was obtained by two rounds of Sephadex LH-20 column chromatography, and showed higher antioxidant activity and inhibition on the proliferation of human lung cancer cells (A549) than Litchi anthocyanins. S3 was further separated to isolate fractions P1–P4, which all showed higher antioxidant activity than vitamin C. P3 showed 32.9% inhibition on A549 cells at 30 μg/mL, higher than other fractions and cis-Dichlorodiamineplatinum (DDP, 0.5 μg/mL), but not as high as the combination of the four fractions. Using HPLC-Q-TOF-MS/MS, one B-type and complex A/B type epicatechin trimers were identified in P3; another B-type and two A/B-type trimers were identified in P4. P1 and P2, containing epicatechin and proanthocyanidin B2, respectively, showed no cell inhibition at 30 μg/mL. It is the first time that the two B type trimers of epicatechins (Litchitannin B1 and B2), have been found in Litchi species. The identified proanthocyanidins were detected in the pericarp of the young fruit, and the levels of the compounds decreased as the fruit developed, correlating to the decreasing patterns of the expression of LcLAR and LcANR, two key genes in the catechin biosynthesis pathway

    Cocktails of pesticide residues in conventional and organic farming systems in Europe – Legacy of the past and turning point for the future

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    Considering that pesticides have been used in Europe for over 70 years, a system for monitoring pesticide residues in EU soils and their effects on soil health is long overdue. In an attempt to address this problem, we tested 340 EU agricultural topsoil samples for multiple pesticide residues. These samples originated from 4 representative EU case study sites (CSS), which covered 3 countries and four of the main EU crops: vegetable and orange production in Spain (S–V and S–O, respectively), grape production in Portugal (P-G), and potato production in the Netherlands (N–P). Soil samples were collected between 2015 and 2018 after harvest or before the start of the growing season, depending on the CSS. Conventional and organic farming results were compared in S–V, S–O and N–P. Soils from conventional farms presented mostly mixtures of pesticide residues, with a maximum of 16 residues/sample. Soils from organic farms had significantly fewer residues, with a maximum of 5 residues/sample. The residues with the highest frequency of detection and the highest content in soil were herbicides: glyphosate and its main metabolite AMPA (P-G, N–P, S–O), and pendimethalin (S–V). Total residue content in soil reached values of 0.8 mg kg−1 for S–V, 2 mg kg−1 for S–O and N–P, and 12 mg kg−1 for P-G. Organic soils presented 70–90% lower residue concentrations than the corresponding conventional soils. There is a severe knowledge gap concerning the effects of the accumulated and complex mixtures of pesticide residues found in soil on soil biota and soil health. Safety benchmarks should be defined and introduced into (soil) legislation as soon as possible. Furthermore, the process of transitioning to organic farming should take into consideration the residue mixtures at the conversion time and their residence time in soil.</p
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