6,964 research outputs found
The Role of CagA Protein Signaling in Gastric Carcinogenesis — CagA Signaling in Gastric Carcinogenesis
Epidemiology and molecular characterization of Carnivore protoparvovirus-1 infection in the wild felid Leopardus guigna in Chile
Landscape anthropization has been identified as one of the main drivers of pathogen emergence worldwide, facilitating pathogen spillover between domestic species and wildlife. The present study investigated Carnivore protoparvovirus-1 infection using molecular methods in 98 free-ranging wild guignas (Leopardus guigna) and 262 co-occurring owned, free-roaming rural domestic cats. We also assessed landscape anthropization variables as potential drivers of infection. Protoparvovirus DNA was detected in guignas across their entire distribution range, with observed prevalence of 13.3% (real-time PCR) and 9% (conventional PCR) in guignas, and 6.1% (conventional PCR) in cats. Prevalence in guigna did not vary depending on age, sex, study area or landscape variables. Prevalence was higher in juvenile cats (16.7%) than in adults (4.4%). Molecular characterization of the virus by amplification and sequencing of almost the entire vp2 gene (1, 746 bp) from one guigna and five domestic cats was achieved, showing genetic similarities to canine parvovirus 2c (CPV-2c) (one guigna and one cat), feline panleukopenia virus (FPV) (one cat), CPV-2 (no subtype identified) (two cats), CPV-2a (one cat). The CVP-2c-like sequence found in a guigna clustered together with domestic cat and dog CPV-2c sequences from South America, suggesting possible spillover from a domestic to a wild species as the origin of infection in guigna. No clinical signs of disease were found in PCR-positive animals except for a CPV-2c-infected guigna, which had haemorrhagic diarrhoea and died a few days after arrival at a wildlife rescue centre. Our findings reveal widespread presence of Carnivore protoparvovirus-1 across the guigna distribution in Chile and suggest that virus transmission potentially occurs from domestic to wild carnivores, causing severe disease and death in susceptible wild guignas
The Ring Imaging Cherenkov detector (RICH) of the AMS experiment
The Alpha Magnetic Spectrometer (AMS) experiment to be installed on the
International Space Station (ISS) will be equipped with a proximity focusing
Ring Imaging Cherenkov (RICH) detector for measuring the electric charge and
velocity of the charged cosmic particles. A RICH prototype consisting of 96
photomultiplier units, including a piece of the conical reflector, was built
and its performance evaluated with ion beam data. Preliminary results of the
in-beam tests performed with ion fragments resulting from collisions of a 158
GeV/c/nuc primary beam of Indium ions (CERN SPS) on a Pb target are reported.
The collected data included tests to the final front-end electronics and to
different aerogel radiators. Cherenkov rings for a large range of charged
nuclei and with reflected photons were observed. The data analysis confirms the
design goals. Charge separation up to Fe and velocity resolution of the order
of 0.1% for singly charged particles are obtained.Comment: 29th International Conference on Cosmic Rays (Pune, India
RELATION BETWEEN MORTALITY FOR FOUR YEARS AND COMPUTERIZED TOMOGRAPHY BY MARSHALL SCORE IN TRAUMATIC BRAIN INJURY CRITICAL PATIENTS
The AMS-RICH velocity and charge reconstruction
The AMS detector, to be installed on the International Space Station,
includes a Ring Imaging Cerenkov detector with two different radiators, silica
aerogel (n=1.05) and sodium fluoride (n=1.334). This detector is designed to
provide very precise measurements of velocity and electric charge in a wide
range of cosmic nuclei energies and atomic numbers. The detector geometry, in
particular the presence of a reflector for acceptance purposes, leads to
complex Cerenkov patterns detected in a pixelized photomultiplier matrix. The
results of different reconstruction methods applied to test beam data as well
as to simulated samples are presented. To ensure nominal performances
throughout the flight, several detector parameters have to be carefully
monitored. The algorithms developed to fulfill these requirements are
presented. The velocity and charge measurements provided by the RICH detector
endow the AMS spectrometer with precise particle identification capabilities in
a wide energy range. The expected performances on light isotope separation are
discussed.Comment: Contribution to the ICRC07, Merida, Mexico (2007); Presenter: F.
Bara
The RICH detector of the AMS-02 experiment: status and physics prospects
The Alpha Magnetic Spectrometer (AMS), whose final version AMS-02 is to be
installed on the International Space Station (ISS) for at least 3 years, is a
detector designed to measure charged cosmic ray spectra with energies up to the
TeV region and with high energy photon detection capability up to a few hundred
GeV. It is equipped with several subsystems, one of which is a proximity
focusing RICH detector with a dual radiator (aerogel+NaF) that provides
reliable measurements for particle velocity and charge. The assembly and
testing of the AMS RICH is currently being finished and the full AMS detector
is expected to be ready by the end of 2008. The RICH detector of AMS-02 is
presented. Physics prospects are briefly discussed.Comment: 5 pages. Contribution to the 10th ICATPP Conference on Astroparticle,
Particle, Space Physics, Detectors and Medical Physics Applications (Como
2007). Presenter: Rui Pereir
Eficiencia de la laguna de oxidación para el tratamiento de aguas residuales domésticas, localidad de Huaro – Cusco
El objetivo fue evaluar la eficiencia de la laguna de oxidación para el tratamiento de las aguas residuales domésticas en la localidad de Huaro, Quispicanchis, región Cusco. Se evaluó las características y riesgo sanitario, de la laguna de oxidación, se hizo un análisis físico-químico y bacteriológico de las aguas residuales del afluente, efluente, vertimiento, y agua del río Huaro (cuerpo receptor), aplicando las metodologías estandarizadas de análisis de laboratorio, propuestas por la OMS, MINSA-DIGESA y MINAM. El mantenimiento y operatividad de la laguna de oxidación es deficiente, por cercanía al recurso hídrico se considera un riesgo sanitario alto, de acuerdo a los análisis físico-químicos del agua residual tanto del afluente, efluente y vertimiento los valores se encontraron por debajo de los LMP de efluentes para vertidos a cuerpos de agua natural a excepción de aceites y grasas se reporta 25 mg/L superando el LMP que es de 20mg/L, al análisis bacteriológico todos los valores del NMP/100ml de Coliformes Termotolerantes encontrados superan los LMP, siendo NO APTAS para vertidos a cuerpos de agua natural, no utilizables para riego de vegetales. De acuerdo al análisis físico-químico y bacteriológico las aguas del rio Huaro arriba del punto de vertimiento, los valores se encuentran por debajo de los LMP, considerándose APTA para riego; sin embargo a partir del punto de vertimiento aguas abajo a pesar de que los valores de los parámetros fisicoquímicos están por debajo de los LMP, los valores de Coliformes Termotolerantes sobrepasan los LMP, siendo NO APTAS para riego de vegetales
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