1,086 research outputs found

    Validation of the ITS2 Region as a Novel DNA Barcode for Identifying Medicinal Plant Species

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    BACKGROUND: The plant working group of the Consortium for the Barcode of Life recommended the two-locus combination of rbcL+matK as the plant barcode, yet the combination was shown to successfully discriminate among 907 samples from 550 species at the species level with a probability of 72%. The group admits that the two-locus barcode is far from perfect due to the low identification rate, and the search is not over. METHODOLOGY/PRINCIPAL FINDINGS: Here, we compared seven candidate DNA barcodes (psbA-trnH, matK, rbcL, rpoC1, ycf5, ITS2, and ITS) from medicinal plant species. Our ranking criteria included PCR amplification efficiency, differential intra- and inter-specific divergences, and the DNA barcoding gap. Our data suggest that the second internal transcribed spacer (ITS2) of nuclear ribosomal DNA represents the most suitable region for DNA barcoding applications. Furthermore, we tested the discrimination ability of ITS2 in more than 6600 plant samples belonging to 4800 species from 753 distinct genera and found that the rate of successful identification with the ITS2 was 92.7% at the species level. CONCLUSIONS: The ITS2 region can be potentially used as a standard DNA barcode to identify medicinal plants and their closely related species. We also propose that ITS2 can serve as a novel universal barcode for the identification of a broader range of plant taxa

    The genome and transcriptome of Japanese flounder provide insights into flatfish asymmetry

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    Flatfish have the most extreme asymmetric body morphology of vertebrates. During metamorphosis, one eye migrates to the contralateral side of the skull, and this migration is accompanied by extensive craniofacial transformations and simultaneous development of lopsided body pigmentation(1-5). The evolution of this developmental and physiological innovation remains enigmatic. Comparative genomics of two flatfish and transcriptomic analyses during metamorphosis point to a role for thyroid hormone and retinoic acid signaling, as well as phototransduction pathways. We demonstrate that retinoic acid is critical in establishing asymmetric pigmentation and, via cross-talk with thyroid hormones, in modulating eye migration. The unexpected expression of the visual opsins from the phototransduction pathway in the skin translates illumination differences and generates retinoic acid gradients that underlie the generation of asymmetry. Identifying the genetic underpinning of this unique developmental process answers long-standing questions about the evolutionary origin of asymmetry, but it also provides insight into the mechanisms that control body shape in vertebrates.National Natural Science Foundation of China [31130057, 31461163005, 31530078, 31472269, 31472262, 31472273]; State 863 High Technology R&D Project of China [2012AA092203, 2012AA10A408, 2012AA10A403-2]; Education and Research of Guangdong Province [2013B090800017]; Taishan Scholar Climb Project Fund of Shandong of China; Taishan Scholar Project Fund of Shandong of China for Young Scientists; Shanghai Universities First-class Disciplines Project of Fisheries; Program for Professor of Special Appointment (Eastern Scholar) at the Shanghai Institutions of Higher Learning; Shanghai Municipal Science, Special Project on the Integration of Industryinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/publishedVersio

    Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

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    Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe

    On the Nexus of SO2 and CO2 emissions in China: the ancillary benefits of CO2 emission reductions

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    Three New Species of Apiospora (Amphisphaeriales, Apiosporaceae) on Indocalamus longiauritus, Adinandra glischroloma and Machilus nanmu from Hainan and Fujian, China

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    Apiospora is widely distributed throughout the world, and most of its hosts are Poaceae. In this study, Arthrinium-like strains were isolated from non-Poaceae in the Hainan and Fujian provinces of China. Based on the combined DNA sequence data of the internal transcriptional spacer (ITS), partial large subunit nuclear rDNA (LSU), translation extension factor 1-&alpha; gene (TEF1-&alpha;) and &beta;-tubulin (TUB2), the collected Apiospora specimens were compared with known species, and three new species were identified. Based on morphological and molecular phylogenetic analyses, Apiospora&nbsp;adinandrae sp. nov., A.&nbsp;bawanglingensis sp. nov. and A.&nbsp;machili sp. nov. are described and illustrated

    Triple-band Metamaterial Polarization Converter Based on Substrate Integrated Waveguide Technology

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    Determination of Synthetic Colorants in Beverages by Deep Eutectic Solvent-Based Effervescence-Assisted Dispersive Liquid–Liquid Microextraction Coupled with High-Performance Liquid Chromatography

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    Abstract In this paper, a deep eutectic solvent (DES)-based effervescence-assisted dispersive liquid–liquid microextraction method was proposed for the determination of four synthetic colorants in beverages by high-performance liquid chromatography. In this method, DES synthesized from choline chloride and phenol was used as extractant. The dispersion of DES was assisted by in situ CO2 produced from the effervescence reaction between NaH2PO4 and Na2CO3 without using any organic solvent or auxiliary equipment. Furthermore, phase separation occurred naturally in the presence of the salt products of effervescence reaction, without the addition of any other salting out reagents. Some important parameters, such as species, molar ratio and volume of DES, composition and amount of effervescent agents, were optimized to achieve the best extraction efficiency. Under the optimal conditions, extraction recoveries were obtained for the analytes in the range of 83.5–114.8%. The limits of detection were in the range of 0.6–3.0 ng/mL. Relative standard deviations for intra- and interday precision were &amp;lt;4.68 and 6.08%, respectively. This simple, rapid, cost-effective and environmentally friendly method has been successfully applied to the analysis of synthetic colorants in 10 kinds of beverage samples.</jats:p

    Modeling the Traveler’s Route Choice Behavior under Unexpected Accidents

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    To investigate the route choice behavior of travelers under unexpected accidents, this study designs four different scenarios of travelers’ route choice behavior experiments according to the severity of unexpected accidents. The bounded rationality characteristics of travelers, such as the time perception difference coefficient, psychological threshold effect coefficient, and scale effect, are introduced into the generalized random regret minimization (GRRM) model. An improved generalized random regret minimization (IGRRM) model is constructed based on travelers’ route choice behavior under unexpected accidents. The collected data of travelers’ route choice results under four different congestion-level scenarios are analyzed by the IGRRM model. The study finds that with the increase in congestion level, travelers are more willing to change the route; during the commute, travelers tend to choose the route with less travel time and angular cost; in the moderate and serious congestion scenarios, travelers no longer reject the detour route; attribute perception difference, scale effect, and psychological threshold effect; affect travelers’ route choice behavior. The IGRRM model based on the route choice behavior of travelers can more accurately characterize the route choice behavior of travelers under unexpected accidents, provide a basis for traffic flow distribution under unexpected accidents, and benefit traffic management departments to take traffic control and guidance measures to ease the traffic congestion caused by unexpected accidents
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