Compuestos de Caucho Reforzado con Sistemas Híbridos

El negro de humo es el refuerzo más utilizado de la industria del caucho. Debido a que se trata de un material derivado de la industria del petróleo, se prevé un aumento en el costo. El objetivo del presente trabajo es estudiar el efecto de la adición de caolín y montmorillonita para formar un sistema híbrido de refuerzo sobre una matriz de SBR, y reducir el uso de negro de humo en las formulaciones de caucho. Se observa que la presencia de montmorillonita aumenta el alargamiento a la rotura, la tracción y el desgarre. El estudio por microscopía detecta un cambio morfológico que justifica la mejora en las propiedades mecánicas. La reología indica que los sistemas híbridos presentan mayor grado de entrecruzamiento. Por otra parte, la montmorillonita retrasa las reacciones de vulcanización, mientras que el caolín no influye en la cinética de curado

Big Data Analytics for Automated QoE Management in Mobile Networks

Over the last years, there has been a significant increase in the number of services in mobile networks. This trend has forced operators to change their network management processes to ensure adequate user QoE, instead of adequate QoS. As a result, customer experience management is now a critical task for mobile network operators, who demand tools for QoE monitoring on an individual user basis. With the latest advances in information technologies, the newest TMA solutions can leverage the huge amount of information available from network elements and interfaces in mobile networks. However, data processing algorithms in these tools are still to be defined. In this work, we review the shortcomings and challenges in the use of TMA applications in mobile networks, and how these can be empowered by big data analytics. For this purpose, a methodology to validate a generic big-data-driven TMA framework with user terminal agents in a real cellular network is outlined. A use case is presented to show the potential and limitations of these applications for monitoring end-user QoE in a live LTE network.Spanish Ministry of Economy and Competitiveness (TEC2015-69982-R) and Ericsson Spain

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

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

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

IP3-dependent, post-tetanic calcium transients induced by electrostimulation of adult skeletal muscle fibers

Tetanic electrical stimulation induces two separate calcium signals in rat skeletal myotubes, a fast one, dependent on Cav 1.1 or dihydropyridine receptors (DHPRs) and ryanodine receptors and related to contraction, and a slow signal, dependent on DHPR and inositol trisphosphate receptors (IP3Rs) and related to transcriptional events. We searched for slow calcium signals in adult muscle fibers using isolated adult flexor digitorum brevis fibers from 5–7-wk-old mice, loaded with fluo-3. When stimulated with trains of 0.3-ms pulses at various frequencies, cells responded with a fast calcium signal associated with muscle contraction, followed by a slower signal similar to one previously described in cultured myotubes. Nifedipine inhibited the slow signal more effectively than the fast one, suggesting a role for DHPR in its onset. The IP3R inhibitors Xestospongin B or C (5 µM) also inhibited it. The amplitude of post-tetanic calcium transients depends on both tetanus frequency and duration, having a maximum at 10–20 Hz. At this stimulation frequency, an increase of the slow isoform of troponin I mRNA was detected, while the fast isoform of this gene was inhibited. All three IP3R isoforms were present in adult muscle. IP3R-1 was differentially expressed in different types of muscle fibers, being higher in a subset of fast-type fibers. Interestingly, isolated fibers from the slow soleus muscle did not reveal the slow calcium signal induced by electrical stimulus. These results support the idea that IP3R-dependent slow calcium signals may be characteristic of distinct types of muscle fibers and may participate in the activation of specific transcriptional programs of slow and fast phenotype

Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

A measurement of the cosmic-ray spectrum for energies exceeding $4{\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\circ}$ detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above $5.3{\times}10^{18}$ eV, the "ankle", the flux can be described by a power law $E^{-\gamma}$ with index $\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)}$ followed by a smooth suppression region. For the energy ($E_\text{s}$) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find $E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19}$ eV.Comment: Replaced with published version. Added journal reference and DO

Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file