67 research outputs found

    Occurrence of Hepatitis E Virus in Pigs and Pork Cuts and Organs at the Time of Slaughter, Spain, 2017

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    Zoonotic hepatitis E, mainly caused by hepatitis E virus (HEV) genotype (gt) 3, is a foodborne disease that has emerged in Europe in recent decades. The main animal reservoir for genotype 3 is domestic pigs. Pig liver and liver derivates are considered the major risk products, and studies focused on the presence of HEV in pig muscles are scarce. The objective of the present study was to evaluate the presence of HEV in different organs and tissues of 45 apparently healthy pigs from nine Spanish slaughterhouses (50% national production) that could enter into the food supply chain. Anti-HEV antibodies were evaluated in serum by an ELISA test. Ten samples from each animal were analyzed for the presence of HEV RNA by reverse transcription real-time PCR (RT-qPCR). The overall seroprevalence obtained was 73.3% (33/45). From the 450 samples analyzed, a total of 26 RT-qPCR positive samples were identified in the liver (7/45), feces (6/45), kidney (5/45), heart (4/45), serum (3/45), and diaphragm (1/45). This is the first report on detection of HEV RNA in kidney and heart samples of naturally infected pigs. HEV RNA detection was negative for rib, bacon, lean ham, and loin samples. These findings indicate that pig meat could be considered as a low risk material for foodborne HEV infection.This study was partially supported by the RTA2014-00024-C04 from the Spanish Ministry of Economy and Innovation. NG and DR-L received a research grant by INTERPORC.S

    Rol protector del ácido clorogénico sobre el daño del ADN causado por la exposición a ocratoxina A

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    Chlorogenic acid (ChlA) has shown short-term protective effects against the cytogenotoxic effects of ochratoxin A (OTA). The present study evaluated the effect of oral administration of ChlA in male Wistar rats exposed to OTA. OTA (0.4 mg/kg bw/ day), ChlA (5 mg/kg bw/day), or the combination of both, were administered orally to animals during 28 days. No deaths, decrease in feed consumption or change in the body weight of animals were observed in any group. In the OTA-treated group a decrease in locomotion as well as increased DNA damage in blood, kidney and bone marrow cells were observed. ChlA alone was not genotoxic for animals. The combination of OTA +ChlA decreased the DNA damage by 37% in blood cells, by 55% in kidney cells and by 80% in bone marrow cells compared to OTA-treated group. In conclusion, oral treatment with ChlA showed a good protective effect on genotoxicity produced by OTA in rats during 28 days exposure.El ácido clorogénico (ChlA) mostró efectos protectores a corto plazo contra los efectos citogenotóxicos de ocratoxina A (OTA). En el presente estudio se evaluó si este polifenol mantiene su efecto protector mediante la administración oral en ratas Wistar machos expuestas a OTA. OTA (0,4 mg/kg/día), ChlA (5 mg/kg/día), o la combinación de ambos, fueron administrados a los animales por vía oral durante 28 días. No se observaron muertes, ni disminución en el consumo de alimento, ni cambios en el peso corporal en ningún grupo de animales. En el grupo tratado con OTA se observó disminución en la locomoción, así como daño en el ADN en las células de sangre, riñón y médula ósea. En los animales que solo recibieron ChlA no se observaron efectos genotóxicos. La combinación de OTA + ChlA disminuyó el daño del ADN en un 37%en las células sanguíneas, en un 55% en las células renales y en un 80% en las células de la médula ósea con respecto al grupo tratado con OTA. En conclusión, el tratamiento oral con ChlA mostró buen efecto protector sobre la genotoxicidad producida por OTA en ratas durante 28 días de exposición.Facultad de Ciencias Veterinaria

    A search for ultra-high-energy photons at the Pierre Auger Observatory exploiting air-shower universality

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    The Pierre Auger Observatory is the most sensitive detector to primary photons with energies above ∼0.2 EeV. It measures extensive air showers using a hybrid technique that combines a fluorescence detector (FD) with a ground array of particle detectors (SD). The signatures of a photon-induced air shower are a larger atmospheric depth at the shower maximum (Xmax_{max}) and a steeper lateral distribution function, along with a lower number of muons with respect to the bulk of hadron-induced background. Using observables measured by the FD and SD, three photon searches in different energy bands are performed. In particular, between threshold energies of 1-10 EeV, a new analysis technique has been developed by combining the FD-based measurement of Xmax_{max} with the SD signal through a parameter related to its muon content, derived from the universality of the air showers. This technique has led to a better photon/hadron separation and, consequently, to a higher search sensitivity, resulting in a tighter upper limit than before. The outcome of this new analysis is presented here, along with previous results in the energy ranges below 1 EeV and above 10 EeV. From the data collected by the Pierre Auger Observatory in about 15 years of operation, the most stringent constraints on the fraction of photons in the cosmic flux are set over almost three decades in energy

    Study on multi-ELVES in the Pierre Auger Observatory

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    Since 2013, the four sites of the Fluorescence Detector (FD) of the Pierre Auger Observatory record ELVES with a dedicated trigger. These UV light emissions are correlated to distant lightning strikes. The length of recorded traces has been increased from 100 μs (2013), to 300 μs (2014-16), to 900 μs (2017-present), to progressively extend the observation of the light emission towards the vertical of the causative lightning and beyond. A large fraction of the observed events shows double ELVES within the time window, and, in some cases, even more complex structures are observed. The nature of the multi-ELVES is not completely understood but may be related to the different types of lightning in which they are originated. For example, it is known that Narrow Bipolar Events can produce double ELVES, and Energetic In-cloud Pulses, occurring between the main negative and upper positive charge layer of clouds, can induce double and even quadruple ELVES in the ionosphere. This report shows the seasonal and daily dependence of the time gap, amplitude ratio, and correlation between the pulse widths of the peaks in a sample of 1000+ multi-ELVES events recorded during the period 2014-20. The events have been compared with data from other satellite and ground-based sensing devices to study the correlation of their properties with lightning observables such as altitude and polarity

    Outreach activities at the Pierre Auger Observatory

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    The ultra-high-energy cosmic-ray sky above 32 EeV viewed from the Pierre Auger Observatory

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    First results from the AugerPrime Radio Detector

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    Update of the Offline Framework for AugerPrime

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    Large-scale and multipolar anisotropies of cosmic rays detected at the Pierre Auger Observatory with energies above 4 EeV

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    Extraction of the Muon Signals Recorded with the Surface Detector of the Pierre Auger Observatory Using Recurrent Neural Networks

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    We present a method based on the use of Recurrent Neural Networks to extract the muon component from the time traces registered with water-Cherenkov detector (WCD) stations of the Surface Detector of the Pierre Auger Observatory. The design of the WCDs does not allow to separate the contribution of muons to the time traces obtained from the WCDs from those of photons, electrons and positrons for all events. Separating the muon and electromagnetic components is crucial for the determination of the nature of the primary cosmic rays and properties of the hadronic interactions at ultra-high energies. We trained a neural network to extract the muon and the electromagnetic components from the WCD traces using a large set of simulated air showers, with around 450 000 simulated events. For training and evaluating the performance of the neural network, simulated events with energies between 1018.5, eV and 1020 eV and zenith angles below 60 degrees were used. We also study the performance of this method on experimental data of the Pierre Auger Observatory and show that our predicted muon lateral distributions agree with the parameterizations obtained by the AGASA collaboration
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