118 research outputs found

    HisAK70: Progress towards a vaccine against different forms of leishmaniosis

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    Background: Leishmania major and Leishmania infantum are among the main species that are responsible for cutaneous leishmaniosis (CL) and visceral leishmaniosis (VL), respectively. The leishmanioses represent the second-largest parasitic killer in the world after malaria. Recently, we succeeded in generating a plasmid DNA (pCMV-HISA70m2A) and demonstrated that immunized mice were protected against L. major challenge. The efficacy of the DNA-vaccine was further enhanced by the inclusion of KMP-11 antigen into the antibiotic-free plasmid pVAX1-asd. Methods: Here, we describe the use of a HisAK70 DNA-vaccine encoding seven Leishmania genes (H2A, H2B, H3, H4, A2, KMP11 and HSP70) for vaccination of mice to assess the induction of a resistant phenotype against VL and CL. Results: HisAK70 was successful in vaccinated mice, resulting in a high amount of efficient sterile hepatic granulomas associated with a hepatic parasite burden fully resolved in the VL model; and resulting in 100 % inhibition of parasite visceralization in the CL model. Conclusions: The results suggest that immunization with the HisAK70 DNA-vaccine may provide a rapid, suitable, and efficient vaccination strategy to confer cross-protective immunity against VL and CL.This work was partially supported by grants from the Spanish Ministry of Economy and Competitiveness (AGL2010-17394 and AGL2013-44100R) and PLATESA (P2013/ABI-2906) from the Comunidad de Madrid (Spain).Peer Reviewe

    An Adaptive Fuzzy Logic System for the Compensation of Nonlinear Distortion in Wireless Power Amplifiers

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    Computational intelligent systems are becoming an increasingly attractive solution for power amplifier (PA) behavioural modelling, due to their excellent approximation capability. This paper utilizes an adaptive fuzzy logic system (AFLS) for the modelling of the highly nonlinear MIMIX CFH2162-P3 PA. Moreover, PA’s inverse model based also on AFLS has been developed in order to act as a pre-distorter unit. Driving an LTE 1.4 MHz 64 QAM signal at 880 MHz as centre frequency at PA’s input, very good modelling performance was achieved, for both PA’s forward and inverse dynamics. A comparative study of AFLS and neural networks (NN) has been carried out to establish AFLS as an effective, robust, and easy-to-implement baseband model, which is suitable for inverse modelling of PAs and capable to be used as an effective digital pre-distorter. Pre-distortion system based on AFLS, achieved distortion suppression of 84.2%, compared to the 48.4% gained using the NN-based equivalent schem

    Precision measurement of CP\it{CP} violation in the penguin-mediated decay Bs0ϕϕB_s^{0}\rightarrow\phi\phi

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    A flavor-tagged time-dependent angular analysis of the decay Bs0ϕϕB_s^{0}\rightarrow\phi\phi is performed using pppp collision data collected by the LHCb experiment at % at s=13\sqrt{s}=13 TeV, the center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 6 fb^{-1}. The CP\it{CP}-violating phase and direct CP\it{CP}-violation parameter are measured to be ϕssˉs=0.042±0.075±0.009\phi_{s\bar{s}s} = -0.042 \pm 0.075 \pm 0.009 rad and λ=1.004±0.030±0.009|\lambda|=1.004\pm 0.030 \pm 0.009 , respectively, assuming the same values for all polarization states of the ϕϕ\phi\phi system. In these results, the first uncertainties are statistical and the second systematic. These parameters are also determined separately for each polarization state, showing no evidence for polarization dependence. The results are combined with previous LHCb measurements using pppp collisions at center-of-mass energies of 7 and 8 TeV, yielding ϕssˉs=0.074±0.069\phi_{s\bar{s}s} = -0.074 \pm 0.069 rad and lambda=1.009±0.030|lambda|=1.009 \pm 0.030. This is the most precise study of time-dependent CP\it{CP} violation in a penguin-dominated BB meson decay. The results are consistent with CP\it{CP} symmetry and with the Standard Model predictions.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2023-001.html (LHCb public pages

    Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model

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    We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO's second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h095%=3.47×10-25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering. © 2019 American Physical Society

    Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model

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    We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO’s second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h95%0=3.47×10−25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering

    Search for continuous gravitational waves from 20 accreting millisecond x-ray pulsars in O3 LIGO data

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    GWTC-2.1: Deep extended catalog of compact binary coalescences observed by LIGO and Virgo during the first half of the third observing run

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    The second Gravitational-Wave Transient Catalog, GWTC-2, reported on 39 compact binary coalescences observed by the Advanced LIGO and Advanced Virgo detectors between 1 April 2019 15 ∶ 00 UTC and 1 October 2019 15 ∶ 00 UTC. Here, we present GWTC-2.1, which reports on a deeper list of candidate events observed over the same period. We analyze the final version of the strain data over this period with improved calibration and better subtraction of excess noise, which has been publicly released. We employ three matched-filter search pipelines for candidate identification, and estimate the probability of astrophysical origin for each candidate event. While GWTC-2 used a false alarm rate threshold of 2 per year, we include in GWTC-2.1, 1201 candidates that pass a false alarm rate threshold of 2 per day. We calculate the source properties of a subset of 44 high-significance candidates that have a probability of astrophysical origin greater than 0.5. Of these candidates, 36 have been reported in GWTC-2. We also calculate updated source properties for all binary black hole events previously reported in GWTC-1. If the eight additional high-significance candidates presented here are astrophysical, the mass range of events that are unambiguously identified as binary black holes (both objects ≥ 3 M⊙ ) is increased compared to GWTC-2, with total masses from ∼ 14 M ⊙ for GW190924_021846 to ∼ 182 M⊙ for GW190426_190642. Source properties calculated using our default prior suggest that the primary components of two new candidate events (GW190403_051519 and GW190426_190642) fall in the mass gap predicted by pair-instability supernova theory. We also expand the population of binaries with significantly asymmetric mass ratios reported in GWTC-2 by an additional two events (the mass ratio is less than 0.65 and 0.44 at 90% probability for GW190403_051519 and GW190917_114630 respectively), and find that two of the eight new events have effective inspiral spins χeff > 0 (at 90% credibility), while no binary is consistent with χeff < 0 at the same significance. We provide updated estimates for rates of binary black hole and binary neutron star coalescence in the local Universe

    All-sky, all-frequency directional search for persistent gravitational waves from Advanced LIGO’s and Advanced Virgo’s first three observing runs

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    We present the first results from an all-sky all-frequency (ASAF) search for an anisotropic stochastic gravitational-wave background using the data from the first three observing runs of the Advanced LIGO and Advanced Virgo detectors. Upper limit maps on broadband anisotropies of a persistent stochastic background were published for all observing runs of the LIGO-Virgo detectors. However, a broadband analysis is likely to miss narrowband signals as the signal-to-noise ratio of a narrowband signal can be significantly reduced when combined with detector output from other frequencies. Data folding and the computationally efficient analysis pipeline, {\tt PyStoch}, enable us to perform the radiometer map-making at every frequency bin. We perform the search at 3072 {\tt{HEALPix}} equal area pixels uniformly tiling the sky and in every frequency bin of width 1/321/32~Hz in the range 20172620-1726~Hz, except for bins that are likely to contain instrumental artefacts and hence are notched. We do not find any statistically significant evidence for the existence of narrowband gravitational-wave signals in the analyzed frequency bins. Therefore, we place 95%95\% confidence upper limits on the gravitational-wave strain for each pixel-frequency pair, the limits are in the range (0.0309.6)×1024(0.030 - 9.6) \times10^{-24}. In addition, we outline a method to identify candidate pixel-frequency pairs that could be followed up by a more sensitive (and potentially computationally expensive) search, e.g., a matched-filtering-based analysis, to look for fainter nearly monochromatic coherent signals. The ASAF analysis is inherently independent of models describing any spectral or spatial distribution of power. We demonstrate that the ASAF results can be appropriately combined over frequencies and sky directions to successfully recover the broadband directional and isotropic results
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