678 research outputs found

    Tissue-Specific Accumulation of Triphenyltin Compounds in Selected Marine Demersal Fishes of Hong Kong

    Get PDF
    Human ImpactsPoster presentation: P-84Applications of organotin-based antifouling paints in hulls of sea-going vessels have introduced large amount of these compounds, in particular tributyltin (TBT) and triphenyltin (TPT), into the ocean since the 1960s. These endocrine disrupting compounds have threatened a wide range of marine organisms, including fishes and marine mammals. In spite of the global prohibition of the use of organotins in antifouling paints by the International Maritime Organization in September 2008, there are no restrictions on their production and usage in Mainland China and Hong Kong and thus high concentrations of organotins, especially TPT, are still detected in marine fishes and ...postprin

    Complete Sequences of the Mitochondrial DNA of the Wild Gracilariopsis lemaneiformis and Two Mutagenic Cultivated Breeds (Gracilariaceae, Rhodophyta)

    Get PDF
    The complete mitochondrial DNA (mtDNA) of Gracilariopsis lemaneiformis was sequenced (25883 bp) and mapped to a circular model. The A+T composition was 72.5%. Forty six genes and two potentially functional open reading frames were identified. They include 24 protein-coding genes, 2 rRNA genes, 20 tRNA genes and 2 ORFs (orf60, orf142). There is considerable sequence synteny across the five red algal mtDNAs falling into Florideophyceae including Gr. lemaneiformis in this study and previously sequenced species. A long stem-loop and a hairpin structure were identified in intergenic regions of mt genome of Gr. lemaneiformis, which are believed to be involved with transcription and replication. In addition, the mtDNAs of two mutagenic cultivated breeds (“981” and “07-2”) were also sequenced. Compared with the mtDNA of wild Gr. lemaneiformis, the genome size and gene length and order of three strains were completely identical except nine base mutations including eight in the protein-coding genes and one in the tRNA gene. None of the base mutations caused frameshift or a premature stop codon in the mtDNA genes. Phylogenetic analyses based on mitochondrial protein-coding genes and rRNA genes demonstrated Gracilariopsis andersonii had closer phylogenetic relationship with its parasite Gracilariophila oryzoides than Gracilariopsis lemaneiformis which was from the same genus of Gracilariopsis

    Exome Sequencing Identifies Compound Heterozygous Mutations in CYP4V2 in a Pedigree with Retinitis Pigmentosa

    Get PDF
    Retinitis pigmentosa (RP) is a heterogeneous group of progressive retinal degenerations characterized by pigmentation and atrophy in the mid-periphery of the retina. Twenty two subjects from a four-generation Chinese family with RP and thin cornea, congenital cataract and high myopia is reported in this study. All family members underwent complete ophthalmologic examinations. Patients of the family presented with bone spicule-shaped pigment deposits in retina, retinal vascular attenuation, retinal and choroidal dystrophy, as well as punctate opacity of the lens, reduced cornea thickness and high myopia. Peripheral venous blood was obtained from all patients and their family members for genetic analysis. After mutation analysis in a few known RP candidate genes, exome sequencing was used to analyze the exomes of 3 patients III2, III4, III6 and the unaffected mother II2. A total of 34,693 variations shared by 3 patients were subjected to several filtering steps against existing variation databases. Identified variations were verified in the rest family members by PCR and Sanger sequencing. Compound heterozygous c.802-8_810del17insGC and c.1091-2A>G mutations of the CYP4V2 gene, known as genetic defects for Bietti crystalline corneoretinal dystrophy, were identified as causative mutations for RP of this family

    Measurement of the cross-section of high transverse momentum vector bosons reconstructed as single jets and studies of jet substructure in pp collisions at √s = 7 TeV with the ATLAS detector

    Get PDF
    This paper presents a measurement of the cross-section for high transverse momentum W and Z bosons produced in pp collisions and decaying to all-hadronic final states. The data used in the analysis were recorded by the ATLAS detector at the CERN Large Hadron Collider at a centre-of-mass energy of √s = 7 TeV;{\rm Te}{\rm V}andcorrespondtoanintegratedluminosityof and correspond to an integrated luminosity of 4.6\;{\rm f}{{{\rm b}}^{-1}}.ThemeasurementisperformedbyreconstructingtheboostedWorZbosonsinsinglejets.ThereconstructedjetmassisusedtoidentifytheWandZbosons,andajetsubstructuremethodbasedonenergyclusterinformationinthejetcentre−of−massframeisusedtosuppressthelargemulti−jetbackground.Thecross−sectionforeventswithahadronicallydecayingWorZboson,withtransversemomentum. The measurement is performed by reconstructing the boosted W or Z bosons in single jets. The reconstructed jet mass is used to identify the W and Z bosons, and a jet substructure method based on energy cluster information in the jet centre-of-mass frame is used to suppress the large multi-jet background. The cross-section for events with a hadronically decaying W or Z boson, with transverse momentum {{p}_{{\rm T}}}\gt 320\;{\rm Ge}{\rm V}andpseudorapidity and pseudorapidity |\eta |\lt 1.9,ismeasuredtobe, is measured to be {{\sigma }_{W+Z}}=8.5\pm 1.7$ pb and is compared to next-to-leading-order calculations. The selected events are further used to study jet grooming techniques

    Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at s√=8 TeV with the ATLAS detector

    Get PDF
    The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fb−1 of proton–proton collision data at √s = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t˜→tχ˜01 or t˜→ bχ˜±1 →bW(∗)χ˜01 , where χ˜01 (χ˜±1 ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t˜ → tχ˜01 . For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ˜01 masses below 30 GeV. For a branching fraction of 50% to either t˜ → tχ˜01 or t˜ → bχ˜±1 , and assuming the χ˜±1 mass to be twice the χ˜01 mass, top squark masses in the range 250–550 GeV are excluded for χ˜01 masses below 60 GeV

    Search for pair-produced long-lived neutral particles decaying to jets in the ATLAS hadronic calorimeter in ppcollisions at √s=8TeV

    Get PDF
    The ATLAS detector at the Large Hadron Collider at CERN is used to search for the decay of a scalar boson to a pair of long-lived particles, neutral under the Standard Model gauge group, in 20.3fb−1of data collected in proton–proton collisions at √s=8TeV. This search is sensitive to long-lived particles that decay to Standard Model particles producing jets at the outer edge of the ATLAS electromagnetic calorimeter or inside the hadronic calorimeter. No significant excess of events is observed. Limits are reported on the product of the scalar boson production cross section times branching ratio into long-lived neutral particles as a function of the proper lifetime of the particles. Limits are reported for boson masses from 100 GeVto 900 GeV, and a long-lived neutral particle mass from 10 GeVto 150 GeV

    Modelling credit spreads with time volatility, skewness, and kurtosis

    Get PDF
    This paper seeks to identify the macroeconomic and financial factors that drive credit spreads on bond indices in the US credit market. To overcome the idiosyncratic nature of credit spread data reflected in time varying volatility, skewness and thick tails, it proposes asymmetric GARCH models with alternative probability density functions. The results show that credit spread changes are mainly explained by the interest rate and interest rate volatility, the slope of the yield curve, stock market returns and volatility, the state of liquidity in the corporate bond market and, a heretofore overlooked variable, the foreign exchange rate. They also confirm that the asymmetric GARCH models and Student-t distributions are systematically superior to the conventional GARCH model and the normal distribution in in-sample and out-of-sample testing

    Photochemical activation of TRPA1 channels in neurons and animals

    Get PDF
    Optogenetics is a powerful research tool because it enables high-resolution optical control of neuronal activity. However, current optogenetic approaches are limited to transgenic systems expressing microbial opsins and other exogenous photoreceptors. Here, we identify optovin, a small molecule that enables repeated photoactivation of motor behaviors in wild type animals. Surprisingly, optovin's behavioral effects are not visually mediated. Rather, photodetection is performed by sensory neurons expressing the cation channel TRPA1. TRPA1 is both necessary and sufficient for the optovin response. Optovin activates human TRPA1 via structure-dependent photochemical reactions with redox-sensitive cysteine residues. In animals with severed spinal cords, optovin treatment enables control of motor activity in the paralyzed extremities by localized illumination. These studies identify a light-based strategy for controlling endogenous TRPA1 receptors in vivo, with potential clinical and research applications in non-transgenic animals, including humans
    • 

    corecore