Cibercultura, internet y salud móvil

Introduction: In light of new technologies, the health area faces new scenarios that are transforming the world. One of these is the mobile health that has gone from being a utopia to a reality. To get to know the areas of electronic health and mobile health, it is essential to understand the background in which these advances are developed. This context is framed in the Internet, cyberculture and collective intelligence which are built on the basis of the complexity of action and human interaction. Objective: To analyze the transcendence of key concepts to understand the underlying of mobile health. Materials and methods: A documentary review of physical texts and electronic databases was made. Results: The information was structured in three categories: the first one was culture, cyberspace and collective intelligence; the second one was action, interaction and the Internet, and the last one was mobile health and apps. Conclusions: For the current Society of information and knowledge, cutting-edge areas such as the Internet and mobile devices are more than a technological trend. They have become axes of innovation and construction of the future. Technology offers fascinating possibilities; however, it is important to find a deeper sense of scientific developments that can change the world as mobile health

Gaussian statistics as an emergent symmetry of the stochastic scalar Burgers equation

Symmetries play a conspicuous role in the large-scale behavior of critical systems. In equilibrium they allow us to classify asymptotics into different universality classes, and out of equilibrium, they sometimes emerge as collective properties which are not explicit in the "bare" interactions. Here we elucidate the emergence of an up-down symmetry in the asymptotic behavior of the stochastic scalar Burgers equation in one and two dimensions, manifested by the occurrence of Gaussian fluctuations even within the time regime controlled by nonlinearities. This robustness of Gaussian behavior contradicts naive expectations due to the detailed relation-including the lack of up-down symmetry-between the Burgers equation and the Kardar-Parisi-Zhang equation, which paradigmatically displays non-Gaussian fluctuations described by Tracy-Widom distributions. We reach our conclusions via a dynamic renormalization group study of the field statistics, confirmed by direct evaluation of the field probability distribution function from numerical simulations of the dynamical equation.We acknowledge valuable comments by M. Castro, J. Krug, and P. Rodríguez-López and funding from the Ministerio de Economía y Competitividad, Agencia Estatal de Investigación, and Fondo Europeo de Desarrollo Regional (Spain and European Union) through Grant No. FIS2015- 66020-C2-1-P. E.R.-F. acknowledges financial support from the Ministerio de Educación, Cultura y Deporte (Spain) through Formación del Profesorado Universitario scholarship No. FPU16/06304

On the asymptotic exactness of Bank-Weiser's estimator

In this paper we analyze an error estimator introduced by Bank and Weiser. We prove that this estimator is asymptotically exact in the energy norm for regular solutions and parallel meshes. By considering a simple example we show that this is not true for general meshes.Departamento de Matemátic

Influence of boron content on the fracture toughness and fatigue crack propagation kinetics of bainitic steels

The relatively good combination of high strength and ductility makes bainitic steels a candidate to replace many other steels in industrial applications. However, in service, ductility and strength are not up to standard requirements. In many industrial components, toughness and fatigue performance are also very relevant. In the present study, bainitic steels with varying content of boron were fabricated, with the aim of analyzing the fracture toughness and changes in the fatigue life. The results show that a relatively small change in the boron content can cause a notable variation in the fracture toughness of bainitic steels. The maximum value obtained in fracture toughness was for the steel with the highest boron content. It was observed that the amount of interlath martensite constituents decreases in steels with the addition of boron, leading to the promotion of the presence of void coalescence and a remarkable rise in the toughness of bainitic steels. An increase on the fatigue life of the bainitic steels with an increase in the boron content was also observed, through analysis by means of Paris’ law. A comprehensive micrographic study was carried out in order to examine the mechanics of fatigue crack growth in the bainitic steels, revealing small longitudinal cracks in bainitic steels that lack boron. These cracks tend to disappear in bainitic steels that contain boron. To elucidate this behavior, micrographs of the surfaces generated by the crack growth process were taken, showing that several nano-cracks appeared between the bainite laths. It is finally argued that this high-energy consumption process of nano-crack nucleation and growth is the reason for the improved toughness and fatigue life observed in bainitic steels.Peer ReviewedPostprint (author's final draft

Diversidad de interpretaciones de la norma matemática asociada a los criterios de legitimación de solución a un problema matemático que involucra los conceptos de frecuencia relativa y frecuencia absoluta en grado sexto

Este escrito es un avance (fase final) del trabajo de grado titulado “Diversidad de interpretaciones de la norma matemática asociada a los criterios de legitimación de solución a un problema matemático que involucra los conceptos de frecuencia relativa y frecuencia absoluta en grado sexto”. El estudio, bajo una estrategia metodológica de estudio de caso, tiene como propósito indagar cuáles son las diversas interpretaciones que un grupo de estudiantes de grado sexto presenta respecto a la norma matemática asociada a la legitimación de la solución de un problema matemático que involucra los conceptos de frecuencia relativa y frecuencia absoluta en grado sexto. En la primera parte se exponen algunos lineamientos teóricos que sustentan el trabajo, posteriormente se presenta un primer análisis de parte de la información recolectada, y en la parte final, a manera de conclusión preliminar, se presentan algunas interpretaciones que hacen los estudiantes bajo estudio de la norma establecida en la clase

Non-KPZ fluctuations in the derivative of the Kardar-Parisi-Zhang equation or noisy Burgers equation

The Kardar-Parisi-Zhang (KPZ) equation is a paradigmatic model of nonequilibrium low-dimensional systems with spatiotemporal scale invariance, recently highlighting universal behavior in fluctuation statistics. Its space derivative, namely the noisy Burgers equation, has played a very important role in its study, predating the formulation of the KPZ equation proper, and being frequently held as an equivalent system. We show that, while differences in the scaling exponents for the two equations are indeed due to a mere space derivative, the field statistics behave in a remarkably different way: while the KPZ equation follows the Tracy-Widom distribution, its derivative displays Gaussian behavior, hence being in a different universality class. We reach this conclusion via direct numerical simulations of the equations, supported by a dynamic renormalization group study of field statistics.We acknowledge valuable comments by B. G. Barreales, M. Castro, J. Krug, P. Rodríguez-López, and J. J. Ruiz-Lorenzo. This work has been supported by Ministerio de Economía y Competitividad, Ministerio de Ciencia, Innovación y Universidades, Agencia Estatal de Investigación, and Fondo Europeo de Desarrollo Regional (Spain and European Union) through Grants No. FIS2015-66020-C2-1-P and No. PGC2018-094763-B-I00. E.R.-F. also acknowledges financial support from Ministerio de Educación, Cultura y Deporte (Spain) through Formación del Profesorado Universitario sco-larship No. FPU16/06304

Transition between chaotic and stochastic universality classes of kinetic roughening

The dynamics of nonequilibrium spatially extended systems are often dominated by fluctuations, e.g., due to deterministic chaos or intrinsic stochasticity. This reflects into generic scale invariant or kinetic roughening behavior that can be classified into universality classes defined by critical exponent values and by the probability distribution function (PDF) of field fluctuations. Suitable geometrical constraints are known to change secondary features of the PDF while keeping the values of the exponents unchanged, inducing universality subclasses. Working on the Kuramoto-Sivashinsky equation as a paradigm of spatiotemporal chaos, we show that the physical nature of the prevailing fluctuations (chaotic or stochastic) can also change the universality class while respecting the exponent values, as the PDF is substantially altered. This transition takes place at a nonzero value of the stochastic noise amplitude and may be suitable for experimental verification.This work has been supported by Ministerio de Economía y Competitividad, Agencia Estatal de Investigación, and Fondo Europeo de Desarrollo Regional (Spain and European Union) through Grant No. PGC2018-094763-B-I00. E.R.-F. also acknowledges financial support by Ministerio de Educación, Cultura y Deporte (Spain) through Formación del Profesorado Universitario Scholarship No. FPU16/06304