307 research outputs found

    Adult triclabendazole-resistant Fasciola hepatica: morphological changes in the tegument and gut following in vivo treatment with artemether in the rat model

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    A study has been carried out to determine the morphological changes to the adult liver fluke, Fasciola hepatica after treatment in vivo with artemether. Rats were infected with the triclabendazole-resistant Sligo isolate of F. hepatica, dosed orally with artemether at a concentration of 200mg/kg and flukes recovered at 24, 48 and 72h post-treatment (p.t.). Surface changes were monitored by scanning electron microscopy and fine structural changes to the tegument and gut by transmission electron microscopy. Twenty-four hours p.t., the external surface showed minor disruption, in the form of mild swelling of the tegument. The tegumental syncytium and sub-tegumental tissues appeared relatively normal. Forty-eight and seventy-two hours p.t., disruption to the tegumental system increased, with isolated patches of surface blebbing and reduced production of secretory bodies by the tegumental cells being the main changes seen. The gastrodermal cells showed a relatively normal morphology 24h p.t. By 48h, large numbers of autophagic vacuoles and lipid droplets were present. Autophagy increased in magnitude by 72h p.t. and substantial disruption to the granular endoplasmic reticulum was observed. Results from this study show that flukes treated in vivo with artemether display progressive and time-dependent alterations to the tegument and gut. Disruption to the gut was consistently and substantially more severe than that to the tegument, suggesting that an oral route of uptake for this compound predominates. This is the first study providing ultrastructural information on the effect of an artemisinin compound against liver fluk

    Automated murmurs: the social mobile tourist application

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    The popularity of mobile devices and their increased computing power has given rise to surge in mobile computing technologies. Users are increasingly turning to mobile devices for information relating to their activities and location while on the move. Independent of this, the world has seen a huge uptake in the social web, which has fueled the production of applications where users are the sole providers of valuable information. In this work we present a mobile platform which leverages the popularity of mobile and social computing to produce a location sensitive messaging system which delivers user generated content to the public in the context of their physical location

    A Hedged Monte Carlo Approach to Real Option Pricing

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    In this work we are concerned with valuing optionalities associated to invest or to delay investment in a project when the available information provided to the manager comes from simulated data of cash flows under historical (or subjective) measure in a possibly incomplete market. Our approach is suitable also to incorporating subjective views from management or market experts and to stochastic investment costs. It is based on the Hedged Monte Carlo strategy proposed by Potters et al (2001) where options are priced simultaneously with the determination of the corresponding hedging. The approach is particularly well-suited to the evaluation of commodity related projects whereby the availability of pricing formulae is very rare, the scenario simulations are usually available only in the historical measure, and the cash flows can be highly nonlinear functions of the prices.Comment: 25 pages, 14 figure

    A randomized controlled trial with a delayed-type hypersensitivity model using keyhole limpet haemocyanin to evaluate adaptive immune responses in man

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    Aims Keyhole limpet haemocyanin (KLH) immunization is a clinical model for the evaluation of human antibody responses. The current study evaluated the anti-KLH antibody response after KLH immunization and the delayed-type hypersensitivity response following intradermal KLH administration, using objective imaging techniques.Methods Healthy male subjects aged 24.5 +/- 5.4 years were randomized to intramuscular immunization with 100 mu g KLH (n = 12) or placebo (n = 3). Anti-KLH antibody (Ig) M and IgG titres were determined before and every 7 days after KLH immunization for a total of 28 days. Twenty-one days after the immunization, all subjects received 1 mu g KLH intradermally. Prior to and 2 days after intradermal KLH administration, skin blood perfusion, erythema and oedema were quantified using noninvasive imaging tools. Repeated measures ANCOVAs were used to analyse data.Results Anti-KLH IgM and IgG titres increased after KLH immunization compared to placebo (estimated difference [ED]: 37%, 95% confidence interval [CI]: 19-51% and ED: 68%, 95% CI: 56-76% respectively). Upon intradermal KLH administration an increase in skin blood perfusion (ED: 10.9 arbitrary units (AU), 95% CI: 1.4-20.4 AU) and erythema (ED: 0.3 AU, 95% CI: 0.1-0.5 AU) was observed in KLH-immunized subjects compared to placebo.Conclusion KLH immunization followed by intradermal KLH administration resulted in increased anti-KLH IgM and IgG titres and a delayed-type hypersensitivity response quantified by an increase in skin blood perfusion and erythema. Using noninvasive imaging tools the KLH model has the potential to serve as an objective tool to study the pharmacodynamics of T-cell-directed immunomodulatory drugs.Drug Delivery Technolog

    Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET

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    The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR

    Measurement of the cross section of high transverse momentum Z→bb̄ production in proton–proton collisions at √s = 8 TeV with the ATLAS detector

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    This Letter reports the observation of a high transverse momentum Z→bb̄ signal in proton–proton collisions at √s=8 TeV and the measurement of its production cross section. The data analysed were collected in 2012 with the ATLAS detector at the LHC and correspond to an integrated luminosity of 19.5 fb−¹. The Z→bb̄ decay is reconstructed from a pair of b -tagged jets, clustered with the anti-ktkt jet algorithm with R=0.4R=0.4, that have low angular separation and form a dijet with pT>200 GeVpT>200 GeV. The signal yield is extracted from a fit to the dijet invariant mass distribution, with the dominant, multi-jet background mass shape estimated by employing a fully data-driven technique that reduces the dependence of the analysis on simulation. The fiducial cross section is determined to be σZ→bb¯fid=2.02±0.20 (stat.) ±0.25 (syst.)±0.06 (lumi.) pb=2.02±0.33 pb, in good agreement with next-to-leading-order theoretical predictions

    Operation and performance of the ATLAS semiconductor tracker

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    The semiconductor tracker is a silicon microstrip detector forming part of the inner tracking system of the ATLAS experiment at the LHC. The operation and performance of the semiconductor tracker during the first years of LHC running are described. More than 99% of the detector modules were operational during this period, with an average intrinsic hit efficiency of (99.74±0.04)%. The evolution of the noise occupancy is discussed, and measurements of the Lorentz angle, δ-ray production and energy loss presented. The alignment of the detector is found to be stable at the few-micron level over long periods of time. Radiation damage measurements, which include the evolution of detector leakage currents, are found to be consistent with predictions and are used in the verification of radiation background simulations

    Search for H→γγ produced in association with top quarks and constraints on the Yukawa coupling between the top quark and the Higgs boson using data taken at 7 TeV and 8 TeV with the ATLAS detector

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    A search is performed for Higgs bosons produced in association with top quarks using the diphoton decay mode of the Higgs boson. Selection requirements are optimized separately for leptonic and fully hadronic final states from the top quark decays. The dataset used corresponds to an integrated luminosity of 4.5 fb−14.5 fb−1 of proton–proton collisions at a center-of-mass energy of 7 TeV and 20.3 fb−1 at 8 TeV recorded by the ATLAS detector at the CERN Large Hadron Collider. No significant excess over the background prediction is observed and upper limits are set on the tt¯H production cross section. The observed exclusion upper limit at 95% confidence level is 6.7 times the predicted Standard Model cross section value. In addition, limits are set on the strength of the Yukawa coupling between the top quark and the Higgs boson, taking into account the dependence of the tt¯H and tH cross sections as well as the H→γγ branching fraction on the Yukawa coupling. Lower and upper limits at 95% confidence level are set at −1.3 and +8.0 times the Yukawa coupling strength in the Standard Model
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