268 research outputs found

    A new formulation to assess the seismic demand of masonry structures by means of input energy

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    The main objective of this paper is to evaluate the elastic input energy of unreinforced masonry structures by means of the input energy spectrum. The energy is a novel approach which allows evaluating in a global and easily way the performance of the masonry structures. Structures modeled with non frame elements require of a great number of 2D or 3D elements, thereby making the calculation of the input energy a complicated issue. In this context, a new formulation that calculates the input energy using an input energy spectrum and the balance of energy is proposed. Two examples of application of unreinforced masonry structures were considered to evaluate the input energy and compare it with the proposed formula. The formula proposed shows interesting results that allowed identify the key features of the accelerograms that influence the input energy into structures

    Autonomy, Good Humor and Support Networks, Potential of Community Resilience Intervention in People Victims of the Earthquake in the Calderón Parish

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    Resilience is a concept widely used in recent years, especially when it comes to evaluating the level of recovery of communities that are hit by natural phenomena. It can be stated that conceptually resilience constitutes the ability to react effectively and quickly to the effects of disasters, being a complex phenomenon to evaluate and define. And although the level of resilience does not necessarily imply greater control of vulnerability, it can be affirmed that the reduction of vulnerable conditions can strengthen and consolidate the resilient capacity of individuals and communities, in the face of the effects of natural disasters

    Estrés a microescala de Vallisneria americana por enriquecimiento de nutrientes con estequiometría N:P

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    To distinguish between the stress of Vallisneria americana caused by increases either in the molar N:P relation (N-NO3 and P-H2PO4) or in the concentration of nutrients (CN), the nutritional regimen (NR) was examined by means of two randomized factorial experiments on plants cultured in vitro in modified MS medium. The first (RN1) crossed N:P relation of 16, 20, and 24 and CN (%) of 25, 50, and 100; while the second (RN2) evaluated N:P relations of 48, 60, 72, and CN percentages of 3.125, 6.25, 12.5, 25, and 50. The mechanism of resistance to the stress by factor was examined with the decrease in the regeneration and viability of leaves and roots; both measured by unit or percentage for 45 to 75 days, since the plants in vitro did not produce ramets. In NR1 experiments, all plants died in 100% CN and leaves registered greater resistance with 24N:P, and 25% CN (p<0.05). The algae grew in 52% of the cultures, without covariance effect (p>0.05). In RN2 experiments, leaves and roots resisted at 72N:P, within the percent ranging from 6.25 to 25 CN (p<0.05). Additional useful information was the significant relationship (p<0.01) found between regenerated leaves and roots (r=0.9), and between regeneration and viability of leaves (r=0.5). The mechanism of stress by the N: P was deciphered by metabolic stoichiometry (protein: RNA). In contrast, the mechanism for the CN was osmotic and fast. At in vitro microscale, resistance to the stress of V. americana, in high N:P and with the supply of N-oxidized, was linked to low nutrient loads.El estrés de Vallisneria americana provocado por incrementos de la relación molar N:P (N-NO3 y P-H2PO4) o por el aumento de la concentración de nutrientes (CN) fue diferenciado mediante el análisis del régimen nutricional (RN), el cual fue examinado con dos experimentos factoriales al azar sobre plantas cultivadas in vitro en medio MS modificado. El primero (RN1) cruzó relaciones N:P de 16, 20 y 24 y CN (%) de 25, 50 y 100; mientras que, el segundo (RN2) evaluó las relaciones N:P de 48, 60, 72 y porcentajes de CN de 3.125, 6.25, 12.5, 25 y 50. El mecanismo de estrés por factor fue analizado con la declinación en regeneración y viabilidad de hojas y raíces, porcentual o unitaria, durante 45 o 75 días, ya que las plantas in vitro no produjeron rametos. En los experimentos RN1, todas las plantas murieron en 100% CN, las hojas reportaron mayor resistencia con 24N:P y 25% CN (p<0.05). Las algas crecieron en el 52% de los cultivos, sin efecto de covarianza (p>0.05). En los RN2, hojas y raíces resistieron en 72N:P dentro del rango porcentual de 6.25 a 25 de CN (p<0.05). Otra información útil fue la correlación significativa (p<0.01) entre hojas y raíces regeneradas (r=0.9) y entre regeneración y viabilidad de hojas (r=0.5). El mecanismo de estrés por la relación N:P fue descifrado mediante estequiometría metabólica (proteína:ARN). En contraste, el mecanismo por la CN fue osmótico y rápido. A microescala in vitro, la resistencia al estrés de V. americana, en N:P elevada y con el suministro de N oxidado, fue vinculado a cargas bajas de nutrientes

    Impact of international travel and diarrhea on gut microbiome and resistome dynamics

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    International travel contributes to the global spread of antimicrobial resistance. Travelers\u27 diarrhea exacerbates the risk of acquiring multidrug-resistant organisms and can lead to persistent gastrointestinal disturbance post-travel. However, little is known about the impact of diarrhea on travelers\u27 gut microbiomes, and the dynamics of these changes throughout travel. Here, we assembled a cohort of 159 international students visiting the Andean city of Cusco, Peru and applied next-generation sequencing techniques to 718 longitudinally-collected stool samples. We find that gut microbiome composition changed significantly throughout travel, but taxonomic diversity remained stable. However, diarrhea disrupted this stability and resulted in an increased abundance of antimicrobial resistance genes that can remain high for weeks. We also identified taxa differentially abundant between diarrheal and non-diarrheal samples, which were used to develop a classification model that distinguishes between these disease states. Additionally, we sequenced the genomes of 212 diarrheagenic Escherichia coli isolates and found those from travelers who experienced diarrhea encoded more antimicrobial resistance genes than those who did not. In this work, we find the gut microbiomes of international travelers\u27 are resilient to dysbiosis; however, they are also susceptible to colonization by multidrug-resistant bacteria, a risk that is more pronounced in travelers with diarrhea

    The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment

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    The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since July 2014. This paper describes the second data release from this phase, and the fourteenth from SDSS overall (making this, Data Release Fourteen or DR14). This release makes public data taken by SDSS-IV in its first two years of operation (July 2014-2016). Like all previous SDSS releases, DR14 is cumulative, including the most recent reductions and calibrations of all data taken by SDSS since the first phase began operations in 2000. New in DR14 is the first public release of data from the extended Baryon Oscillation Spectroscopic Survey (eBOSS); the first data from the second phase of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2), including stellar parameter estimates from an innovative data driven machine learning algorithm known as "The Cannon"; and almost twice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous release (N = 2812 in total). This paper describes the location and format of the publicly available data from SDSS-IV surveys. We provide references to the important technical papers describing how these data have been taken (both targeting and observation details) and processed for scientific use. The SDSS website (www.sdss.org) has been updated for this release, and provides links to data downloads, as well as tutorials and examples of data use. SDSS-IV is planning to continue to collect astronomical data until 2020, and will be followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14 happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov 2017 (this is the "post-print" and "post-proofs" version; minor corrections only from v1, and most of errors found in proofs corrected

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

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    A measurement of the cosmic-ray spectrum for energies exceeding 4×10184{\times}10^{18} eV is presented, which is based on the analysis of showers with zenith angles greater than 6060^{\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 5.3×10185.3{\times}10^{18} eV, the "ankle", the flux can be described by a power law EγE^{-\gamma} with index γ=2.70±0.02(stat)±0.1(sys)\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)} followed by a smooth suppression region. For the energy (EsE_\text{s}) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find Es=(5.12±0.25(stat)1.2+1.0(sys))×1019E_\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
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