139 research outputs found

    Propuesta de diseño de pavimento con geometría Optimizada para evitar agrietamiento en la Calle Zarumilla Cuadra 17, Jaén, Cajamarca

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    El objetivo fue proponer el diseño de pavimento con Geometría Optimizada para evitar agrietamiento en la calle Zarumilla Cuadra 17, Jaén, Cajamarca. La metodología fue: Investigación de tipo aplicada. Según su enfoque es cuantitativo por el uso del software OptiPave 2 y según su alcance es de tipo descriptivo al especificarse los parámetros y características del proceso de diseño estructural del pavimento. El diseño es no experimental transversal descriptivo correlacional causal. La muestra es la calle Zarumilla Cuadra 17 del distrito de Jaén, Provincia de Jaén de la Región Cajamarca. La población es la infraestructura vial del distrito de Jaén; siendo una muestra no probabilística. Tenemos como resultados propuestos: En el diseño del pavimento largo de losa 1.75 m, espesor 130 mm, porcentaje de losa agrietada 4.16% al finalizar la vida útil del pavimento, escalonamiento 0.07 mm e IRI 2.44 m/km. Conclusión: Se acepta la hipótesis general “el pavimento con Geometría Optimizada evitará el agrietamiento en la calle Zarumilla Cuadra 17, Jaén, Cajamarca

    Enfermedad neumocócica invasiva en pacientes de un hospital pediátrico de Perú, 2017-2020

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    El propósito del presente estudio fue describir las características clínicas, serotipos y susceptibilidad antibiótica en pacientes con enfermedad neumocócica invasiva (ENI). Se revisaron las historias clínicas de los pacientes con ENI hospitalizados en el Instituto Nacional de Salud del Niño-Breña (Lima, Perú). Se evaluaron a 29 pacientes. La mediana de edad fue 1,9 años (rango intercuartílico 1 a 4 años). El 51,7% eran mujeres y la forma clínica de la ENI más frecuente fue la bacteriemia en 18 (62,1%) pacientes. El 65,5% tenía el esquema de vacunación completo, según el Ministerio de Salud de Perú. El 82,8% del aislamiento del germen fue de sangre. La resistencia antibiótica fue más frecuente a la eritromicina (55,2%), trimetoprim-sulfametoxazol (48,3%) y penicilina (24,1%). Los serotipos registrados fueron 6C, 19A, 23A y 24F. Un paciente falleció por meningitis. En conclusión, la ENI fue más frecuente en niños de uno a cinco años y en la forma clínica de bacteriemia. Se encontraron cinco serotipos reportados en estudios previos con resistencia a penicilina y eritromicina

    Accelerating to Zero: Strategies to Eliminate Malaria in the Peruvian Amazon.

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    AbstractIn February 2014, the Malaria Elimination Working Group, in partnership with the Peruvian Ministry of Health (MoH), hosted its first international conference on malaria elimination in Iquitos, Peru. The 2-day meeting gathered 85 malaria experts, including 18 international panelists, 23 stakeholders from different malaria-endemic regions of Peru, and 11 MoH authorities. The main outcome was consensus that implementing a malaria elimination project in the Amazon region is achievable, but would require: 1) a comprehensive strategic plan, 2) the altering of current programmatic guidelines from control toward elimination by including symptomatic as well as asymptomatic individuals for antimalarial therapy and transmission-blocking interventions, and 3) the prioritization of community-based active case detection with proper rapid diagnostic tests to interrupt transmission. Elimination efforts must involve key stakeholders and experts at every level of government and include integrated research activities to evaluate, implement, and tailor sustainable interventions appropriate to the region

    Measurements of Cloud Base Height and Coverage using Elastic Multiangle Lidar Scans at the Pierre Auger Observatory

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    Studies of the mass composition of cosmic rays and proton-proton interaction cross-sections at ultra-high energies with the Pierre Auger Observatory

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    In this work, we present an estimate of the cosmic-ray mass composition from the distributions of the depth of the shower maximum (Xmax) measured by the fluorescence detector of the Pierre Auger Observatory. We discuss the sensitivity of the mass composition measurements to the uncertainties in the properties of the hadronic interactions, particularly in the predictions of the particle interaction cross-sections. For this purpose, we adjust the fractions of cosmic-ray mass groups to fit the data with Xmax distributions from air shower simulations. We modify the proton-proton cross-sections at ultra-high energies, and the corresponding air shower simulations with rescaled nucleus-air cross-sections are obtained via Glauber theory. We compare the energy-dependent composition of ultra-high-energy cosmic rays obtained for the different extrapolations of the proton-proton cross-sections from low-energy accelerator data

    Study of downward Terrestrial Gamma-ray Flashes with the surface detector of the Pierre Auger Observatory

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    The surface detector (SD) of the Pierre Auger Observatory, consisting of 1660 water-Cherenkov detectors (WCDs), covers 3000 km2 in the Argentinian pampa. Thanks to the high efficiency of WCDs in detecting gamma rays, it represents a unique instrument for studying downward Terrestrial Gamma-ray Flashes (TGFs) over a large area. Peculiar events, likely related to downward TGFs, were detected at the Auger Observatory. Their experimental signature and time evolution are very different from those of a shower produced by an ultrahigh-energy cosmic ray. They happen in coincidence with low thunderclouds and lightning, and their large deposited energy at the ground is compatible with that of a standard downward TGF with the source a few kilometers above the ground. A new trigger algorithm to increase the TGF-like event statistics was installed in the whole array. The study of the performance of the new trigger system during the lightning season is ongoing and will provide a handle to develop improved algorithms to implement in the Auger upgraded electronic boards. The available data sample, even if small, can give important clues about the TGF production models, in particular, the shape of WCD signals. Moreover, the SD allows us to observe more than one point in the TGF beam, providing information on the emission angle

    Combined fit to the spectrum and composition data measured by the Pierre Auger Observatory including magnetic horizon effects

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    The measurements by the Pierre Auger Observatory of the energy spectrum and mass composition of cosmic rays can be interpreted assuming the presence of two extragalactic source populations, one dominating the flux at energies above a few EeV and the other below. To fit the data ignoring magnetic field effects, the high-energy population needs to accelerate a mixture of nuclei with very hard spectra, at odds with the approximate E2^{-2} shape expected from diffusive shock acceleration. The presence of turbulent extragalactic magnetic fields in the region between the closest sources and the Earth can significantly modify the observed CR spectrum with respect to that emitted by the sources, reducing the flux of low-rigidity particles that reach the Earth. We here take into account this magnetic horizon effect in the combined fit of the spectrum and shower depth distributions, exploring the possibility that a spectrum for the high-energy population sources with a shape closer to E2^{-2} be able to explain the observations

    Measuring the muon content of inclined air showers using AERA and the water-Cherenkov detector array of the Pierre Auger Observatory

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    The dynamic range of the upgraded surface-detector stations of AugerPrime

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    The detection of ultra-high-energy cosmic rays by means of giant detector arrays is often limited by the saturation of the recorded signals near the impact point of the shower core at the ground, where the particle density dramatically increases. The saturation affects in particular the highest energy events, worsening the systematic uncertainties in the reconstruction of the shower characteristics. The upgrade of the Pierre Auger Observatory, called AugerPrime, includes the installation of an 1-inch Small PhotoMultiplier Tube (SPMT) inside each water-Cherenkov station (WCD) of the surface detector array. The SPMT allows an unambiguous measurement of signals down to about 250m from the shower core, thus reducing the number of events featuring a saturated station to a negligible level. In addition, a 3.8m2 plastic scintillator (Scintillator Surface Detector, SSD) is installed on top of each WCD. The SSD is designed to match the WCD (with SPMT) dynamic range, providing a complementary measurement of the shower components up to the highest energies. In this work, the design and performances of the upgraded AugerPrime surface-detector stations in the extended dynamic range are described, highlighting the accuracy of the measurements. A first analysis employing the unsaturated signals in the event reconstruction is also presented

    Investigating multiple elves and halos above strong lightning with the fluorescence detectors of the Pierre Auger Observatory

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    ELVES are being studied since 2013 with the twenty-four FD Telescopes of the Pierre Auger Observatory, in the province of Mendoza (Argentina), the world’s largest facility for the study of ultra-high energy cosmic rays. This study exploits a dedicated trigger and extended readout. Since December 2020, this trigger has been extended to the three High levation Auger Telescopes (HEAT), which observe the night sky at elevation angles between 30 and 60 degrees, allowing a study of ELVES from closer lightning. The high time resolution of the Auger telescopes allows us to upgrade reconstruction algorithms and to do detailed studies on multiple ELVES. The origin of multiple elves can be studied by analyzing the time difference and the amplitude ratio between flashes and comparing them with the properties of radio signals detected by the ENTLN lightning network since 2018. A fraction of multi-ELVES can also be interpreted as halos following ELVES. Halos are disc-shaped light transients emitted at 70-80 km altitudes, appearing at the center of the ELVES rings, due to the rearrangement of electric charges at the base of the ionosphere after a strong lightning event
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