Glaciers in Peruvian Andes play an important role for local hydrology. To quantify the availability of glacier meltwater in a climate change scenario, surface energy (SEB) and mass balance (MB) models are required. However, few studies of SEB and MB modeling using coupled process-based models were carried out for this region. In this study, we use the newly updated COupled Snowpack and Ice surface energy and mass balance model in PYthon (COSIPY) in its 2-dimesnional spatially distributed version to simulate energy and mass fluxes over Artesonraju Glacier, Peruvian Andes, from 2016 to 2018. A glacier mass balance program was started at this glacier in 1995, with installation of a network of 22 ablation stakes and two automatic weather stations were started operating since 2005. COSIPY is forced by weather parameters like solar radiation, air temperature, relativity humidity, air pressure,...

MAX phase thin films have been synthesized by thermal treatment of a Ti-Al-C multilayer system. The preparation of the multilayer system was carried out via magnetron sputtering. Based on the thickness ratio among the individual nanoscale monolayers (Ti, Al, C), the resulting MAX phase stoichiometry can be controlled. This paper describes the synthesis of both Ti2AlC and Ti3AlC2 MAX phases from the same precursor multilayer system which is composed of a sequence of Ti/Al/C pure elemental single layers with thicknesses of 14, 6, and 3.5 nm, respectively. This sequence is repeated 22 times with a total thickness of around 500 nm. Rapid thermal treatment tests were performed to study the phase development. The Ti2AlC MAX phase forms in a temperature range below 850 °C, whereas the Ti3AlC2 MAX phase starts to form at temperatures above 850 °C and reaches its highest phase purity at 950 °C...

In this research, the influence of the stiffness irregularity and the p-delta effect on the structural behavior of a reinforced concrete building is analyzed. The main objective is to determine the impact of the stiffness irregularity and the p-delta effect on the structural behavior in regular and irregular buildings. First, the linear dynamic analysis procedure is performed in order to determine the structural response in terms of drifts, shear force and moments per floor. Subsequently, we proceed with the nonlinear static analysis procedure to obtain the capacity curve of the structure. The post elastic stiffness and the overall ductility of the structure are determined from the capacity curve. Finally, a comparative analysis of the responses from the linear and nonlinear analysis is carried out to determine the percentage variation of the results. When analyzing the structures that c...

In this article, we study the existence of weak solutions for a fractional type problem driven by a nonlocal operator of elliptic type (-Δ)sa1u - λa2(|u|)u = ƒ(x, u) + g(x)|u|q(x)-2u in Ω u = 0 in ℝN \ Ω. Our approach is based on critical point theorems and variational methods.

La implementación de métodos y sistemas para la evaluación de los niveles de radionucleídos emisores alfa, tales como los descendientes del uranio y torio, que tienen un aporte a la dosis anual que recibe la población de una determinada región es importante. En virtud de un contrato de investigación entre el Organismo Internacional de Energía Atómica, se desarrollaron las metodologías y la adaptación a nuestras condiciones de laboratorio; igualmente, se ensambló la cadena de espectroscopía alfa y se iniciaron los tratamientos radioquímicos y las lecturas instrumentales preliminares. El presente informe muestra los resultados y las evaluaciones estadísticas obtenidas durante esta segunda etapa del Proyecto, que ha permitido un avance en la implementación de nuestros métodos de ensayo analíticos e instrumentales para la determinación de radionucleídos emisores alfa.

The aim of this study was to determine the antimicrobial resistance of 176 Escherichia coli strains isolated from broiler chicken organs. The strains were challenged with beta-lactam, quinolones and fluoroquinolones, observing resistance to beta-lactam antibiotics (97.7%) and quinolones (86.7%). The results showed that 71.6% of the isolates phenotypically expressed the production of extended spectrum beta-lactamases (ESLB). By PCR, resistance genes for beta-lactams blaTEM, blaSHV, blaCTX-M1 and Amp-C and resistance genes for quinolones qnrA, qnrB, qnrS were determined. The genes Amp-C (74%), blaCTX-M (65%), blaSHV (65%), blaTEM (50%), qnrB (86.4%) and qnrS (11.9%) were found. The qnrA gene was not evident in the samples analysed. The results obtained revealed a large percentage of resistance to the studied antibiotics and the presence of resistance genes in isolates from poultry for huma...

The aim of this study was to determine the antimicrobial resistance of 176 Escherichia coli strains isolated from broiler chicken organs. The strains were challenged with beta-lactam, quinolones and fluoroquinolones, observing resistance to beta-lactam antibiotics (97.7%) and quinolones (86.7%). The results showed that 71.6% of the isolates phenotypically expressed the production of extended spectrum beta-lactamases (ESLB). By PCR, resistance genes for beta-lactams blaTEM, blaSHV, blaCTX-M1 and Amp-C and resistance genes for quinolones qnrA, qnrB, qnrS were determined. The genes Amp-C (74%), blaCTX-M (65%), blaSHV (65%), blaTEM (50%), qnrB (86.4%) and qnrS (11.9%) were found. The qnrA gene was not evident in the samples analysed. The results obtained revealed a large percentage of resistance to the studied antibiotics and the presence of resistance genes in isolates from poultry for huma...

The aim of this study was to determine the percentage of sensitivity or resistance of strains of E. coli isolated from asymptomatic broiler chicken against 18 common antibiotics used in poultry and in human medicine. In addition, strains that produce extended-spectrum beta-lactamases (ESBL) from a farm or slaughterhouses in the poultry area of Santander, Colombia. The circulation of strains resistant to beta-lactams, cephalosporins, aminoglycosides, quinolones and sulfonamides was determined, as well as antibiotics widely used in other non-farm environments. The content of the bursa of Fabricius was cultivated in McConkey agar obtaining 46 strains of E. coli. Susceptibility tests (n=18) were conducted to the isolated strains, and 91% of the strains were resistant to ampicillin and 80% to cephalosporins. The association of antibiotics with beta-lactamase inhibitors (ampicillin sulbactam a...

The aim of this study was to determine the percentage of sensitivity or resistance of strains of E. coli isolated from asymptomatic broiler chicken against 18 common antibiotics used in poultry and in human medicine. In addition, strains that produce extended-spectrum beta-lactamases (ESBL) from a farm or slaughterhouses in the poultry area of Santander, Colombia. The circulation of strains resistant to beta-lactams, cephalosporins, aminoglycosides, quinolones and sulfonamides was determined, as well as antibiotics widely used in other non-farm environments. The content of the bursa of Fabricius was cultivated in McConkey agar obtaining 46 strains of E. coli. Susceptibility tests (n=18) were conducted to the isolated strains, and 91% of the strains were resistant to ampicillin and 80% to cephalosporins. The association of antibiotics with beta-lactamase inhibitors (ampicillin sulbactam a...

In this work, we propose a method to retrieve the thickness and optical constants of dielectric thin films from single optical transmittance measurements. The method is based on the envelope method and requires a simple dispersion model for the real part of the refractive index with few fitting parameters, while the absorption coefficient can be determined without the aid of a dispersion model. The wavelength-dependent optical constants can be obtained even from spectra that exhibit few interference fringes. We have tested the method with simulated and real transmittance data from thin films in the spectral range covering the fundamental absorption. In order to assess the method’s reliability to retrieve the optical constants and optical bandgap, a comparison is performed with the method by Chambouleyron, known as the Pointwise Unconstrained Minimization Approach, and a fit using the C...

Hepatitis C virus (HCV) has high genomic variability and, since its discovery, at least six different types and an increasing number of sub-types have been reported. There is not knowledge about the degree of genetic variation among HCV strains circulating in the Andean region of South America. In order to study the degree of genetic variability of strains isolated at the HNERM, in this preliminary study it was obtained the sequences from the 5’ non coding region (5’ NCR) belonging to 12 patients and were reported to the GenBank obtaining the accession identifications.

El tratamiento quirúrgico de las vías biliares, será tema de comunicación científica constante tanto en congresos, revistas, simposiums, etc., de acuerdo con la aparición de nuevos procedimientos. Actualmente somos testigos y protagonistas de acontecimientos que están sucediendo en los últimos 10 años y que están cambiando los conceptos clásicos del tratamiento Quirúrgico de patologías del Aparato Digestivo. Es en mérito de estos cambios que comunicamos nuestras primeras experiencias de 157 casos de Cirugía Laparoscópica realizadas en nuestro servicio y de éstos, 153 fueron Colecistectomía, una Esplenectomía, una Cirugía de Hernia de Morgagni, una Vagotomía Troncular Bilateral Supra-diafragmática por toracoscopía y otra exploración y biopsia de Tumor Hepático. Asimismo, en uno de nuestros pacientes el estudio ecográfico pre-operatorio reveló, presencia de Polip...