Evidence of a decadal solar signal in the Amazon River: 1903 to 2013

It has been shown that tropical climates can be notably influenced by the decadal solar cycle; however, the relationship between this solar forcing and the tropical Amazon River has been overlooked in previous research. In this study, we reveal evidence of such a link by analyzing a 1903-2013 record of Amazon discharge. We identify a decadal flow cycle that is anticorrelated with the solar activity measured by the decadal sunspot cycle. This relationship persists through time and appears to result from a solar influence on the tropical Atlantic Ocean. The amplitude of the decadal solar signal in flow is apparently modulated by the interdecadal North Atlantic variability. Because Amazonia is an important element of the planetary water cycle, our findings have implications for studies on global change.Fil: Antico, Andres. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Torres, Maria Eugenia. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas; Argentina. Universidad Nacional de Entre Ríos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentin

Chemical Oscillations out of Chemical Noise

The dynamics of one species chemical kinetics is studied. Chemical reactions are modelled by means of continuous time Markov processes whose probability distribution obeys a suitable master equation. A large deviation theory is formally introduced, which allows developing a Hamiltonian dynamical system able to describe the system dynamics. Using this technique we are able to show that the intrinsic fluctuations, originated in the discrete character of the reagents, may sustain oscillations and chaotic trajectories which are impossible when these fluctuations are disregarded. An important point is that oscillations and chaos appear in systems whose mean-field dynamics has too low a dimensionality for showing such a behavior. In this sense these phenomena are purely induced by noise, which does not limit itself to shifting a bifurcation threshold. On the other hand, they are large deviations of a short transient nature which typically only appear after long waiting times. We also discuss the implications of our results in understanding extinction events in population dynamics models expressed by means of stoichiometric relations

Technical evaluation and analysis cost / benefit for the implementation of the project construction system Durapanel housing, commercial, institutional and industrial

Para empresas del sector de la construcción el tiempo es una variable a tener en cuenta para el desarrollo de un proyecto constructivo, que se podría representar en un problema económico para una empresa si sus proyectos no son entregados a tiempo. De tal manera que en el sector se han implementado sistemas constructivos industrializados para atacar el tiempo, y así desarrollar un sistema mecanizado en la construcción; dentro de estos sistemas se encuentra el DURAPANEL, el cual es un sistema nuevo constructivo que pueden emplear las empresas dedicadas a proyectos constructivos de vivienda, comercial, institucional e industrial. Es por eso que se expone el análisis de costo/beneficio y la evaluación técnica de DURAPANEL para que las empresas de la construcción puedan emplear este sistema constructivo para sus proyectos, y que su departamento técnico pueda determinar que este sistema puede ser de gran ayuda para mejorar sus rendimientos comparados con otros sistemas convencionales.For companies in the construction time is a variable to consider in the development of a construction project, which could represent an economic problem for a company if their projects are not delivered on time. So that in the sector have been implemented industrialized building systems to attack time, and develop a mechanized system in construction; within these systems is the DURAPANEL, which is a new construction system that may employ dedicated to building projects housing, commercial, institutional and industrial. That's why the analysis cost / benefit and technical evaluation of DURAPANEL exposed to the construction companies can use this construction system for their projects and their technical department to determine that this system can be of great help to improve their performances compared to conventional systems

A framework to test modified gravity using galaxy surveys

We study the application of the marked correlation function, M, to probe gravity using the large scale structure of the Universe. We focus our efforts on testing the f(R) modified gravity theory introduced by Hu & Sawicki 2007. This model mimics the cosmic acceleration at late times through the introduction of new physics when the curvature terms are replaced by a function of the Ricci scalar R, rather than by invoking the cosmological constant. These modifications to the gravity equations lead to changes in the environments of large-scale structures that could, in principle, be used to distinguish this model from GR. We use data from the LOWZ and CMASS luminous red galaxy samples of SDSS-III BOSS to measure the marked statistic over a range of scales. To compare with the data, we create mock galaxy catalogues using the halo occupation distribution (HOD) prescription, to populate haloes from N-body simulations using GR and f(R) gravity. Using the Monte Carlo Markov Chain algorithm, we extract the number density and two-point clustering from the mock catalogues and compare with the observational measurements to constrain the HOD model parameters. Weights for individual galaxies are based on the local density information, calculated using a Voronoi tessellation, and are used to mark galaxies when computing the marked correlation function. We find that when taking into account the 1-sigma confidence interval for the best fitting HOD parameters, the marked correlation function only marginally distinguishes viable gravity models at the 1-sigma level for separations rp < 1.7 Mpc/h. As part of the process of evaluating the suitability of the N-body simulations to build mock catalogues, we address the question of the mass resolution of the halo catalogue, and introduce a simple scheme to allow the use of marginally resolved halos