Macroscopic evidence of microscopic dynamics in the Fermi-Pasta-Ulam oscillator chain from nonlinear time series analysis

The problem of detecting specific features of microscopic dynamics in the macroscopic behavior of a many-degrees-of-freedom system is investigated by analyzing the position and momentum time series of a heavy impurity embedded in a chain of nearest-neighbor anharmonic Fermi-Pasta-Ulam oscillators. Results obtained in a previous work [M. Romero-Bastida, Phys. Rev. E {\bf69}, 056204 (2004)] suggest that the impurity does not contribute significantly to the dynamics of the chain and can be considered as a probe for the dynamics of the system to which the impurity is coupled. The ($r,\tau$) entropy, which measures the amount of information generated by unit time at different scales $\tau$ of time and $r$ of the observable, is numerically computed by methods of nonlinear time-series analysis using the position and momentum signals of the heavy impurity for various values of the energy density $\epsilon$ (energy per degree of freedom) of the system and some values of the impurity mass $M$. Results obtained from these two time series are compared and discussed.Comment: 7 pages, 5 figures, RevTeX4 PRE format; to be published in Phys. Rev.

Distributed Computing in the Asynchronous LOCAL model

The LOCAL model is among the main models for studying locality in the framework of distributed network computing. This model is however subject to pertinent criticisms, including the facts that all nodes wake up simultaneously, perform in lock steps, and are failure-free. We show that relaxing these hypotheses to some extent does not hurt local computing. In particular, we show that, for any construction task $T$ associated to a locally checkable labeling (LCL), if $T$ is solvable in $t$ rounds in the LOCAL model, then $T$ remains solvable in $O(t)$ rounds in the asynchronous LOCAL model. This improves the result by Casta\~neda et al. [SSS 2016], which was restricted to 3-coloring the rings. More generally, the main contribution of this paper is to show that, perhaps surprisingly, asynchrony and failures in the computations do not restrict the power of the LOCAL model, as long as the communications remain synchronous and failure-free

Geodesic Deviation Equation in Bianchi Cosmologies

We present the Geodesic Deviation Equation (GDE) for the Friedmann-Robertson-Walker(FRW) universe and we compare it with the equation for Bianchi type I model. We justify consider this cosmological model due to the recent importance the Bianchi Models have as alternative models in cosmology. The main property of these models, solutions of Einstein Field Equations (EFE) is that they are homogeneous as the FRW model but they are not isotropic. We can see this because they have a non-null Weyl tensor in the GDE.Comment: Submitted to Journal of Physics: Conference Series (JPCS), ERE200

Path Integral Approach to Strongly Nonlinear Composite

We study strongly nonlinear disordered media using a functional method. We solve exactly the problem of a nonlinear impurity in a linear host and we obtain a Bruggeman-like formula for the effective nonlinear susceptibility. This formula reduces to the usual Bruggeman effective medium approximation in the linear case and has the following features: (i) It reproduces the weak contrast expansion to the second order and (ii) the effective medium exponent near the percolation threshold are $s=1$, $t=1+\kappa$, where $\kappa$ is the nonlinearity exponent. Finally, we give analytical expressions for previously numerically calculated quantities.Comment: 4 pages, 1 figure, to appear in Phys. Rev.

Status of the left ventricle after arterial switch operation for transposition of the great arteries Hemodynamic and echocardiographic evaluation

AbstractBackground : The potential for improved preservation of systemic ventricular function represents an important reason for the increasing popularity of the arterial switch operation. In support of this expectation, prior studies in patients early after arterial switch operation have found normal ventricular contractility and function. This study was conducted to extend those observations to up to 10 years of follow-up and to directly examine the effects of a coexisting ventricular septal defect or short-term preparatory banding of the pulmonary artery before the arterial switch operation. Methods : Patients operated on from 1983 through 1991 were included. Echocardiographic and catheterization data were collected as part of a prospective evaluation of outcome in all patients who undergo the arterial switch operation at Boston Children's Hospital, with inclusion of data from the most recent catheterization only. Echocardiograms performed at least 6 months after the operation were included, with assessment of both the most recent status as well as serial trends. Whenever possible, echocardiographic evaluation included data necessary to perform analysis of ventricular mechanics including indices of afterload, preload, and contractility. Comparison was made to normal values and between subgroups defined on the basis of an arterial switch operation with or without ventricular septal defect and those who had a rapid two-stage arterial switch operation. Results : Invasive measures of left and right ventricular filling pressures, cardiac index, and pulmonary vascular resistance did not differ among the three groups. Overall, echocardiographic left ventricular end-diastolic dimension, wall thickness, mass, afterload (end-systolic wall stress), function (fractional shortening and rate-corrected velocity of fiber shortening), contractility (stress-velocity and stress-shortening relations), and preload were normal, and none of these variables was different between the groups with and without a ventricular septal defect. Serial evaluation indicated a slight but significant trend toward ventricular dilatation, perhaps related to a relatively high incidence of at least mild aortic regurgitation (30%). In contrast, in the rapid two-stage group the echocardiographic indices of left ventricular function (fractional shortening and velocity of fiber shortening) and contractility (stress-velocity and stress-shortening relations) were found to be mildly but significantly reduced compared with normal subjects and with the other arterial switch operation groups. Over the duration of follow-up encompased by this study, no tendency toward progressive depression of function was seen. Conclusions : As the length of observation after the arterial switch operation continues to increase, left ventricular size, mass, functional status, and contractility continues to be normal, with no evidence of time-related deterioration of function. As previously reported, the rapid two-stage arterial switch operation does represent a higher risk for mild impairment of myocardial mechanics. (J T horac C ardiovasc S urg 1995;109:311-21

Memantine protects cholinergic and glutamatergic septal neurons from Aβ1-40-induced toxicity

The medial septal region (medial septum and diagonal band of Broca, MS/DB) controls hippocampal excitability and synaptic plasticity. MS/DB cholinergic neurons degenerate early in Alzheimer\u27s disease (AD). The presence of MS/DB glutamatergic neurons that project to the hippocampus and are vulnerable to Aβ suggests that excitotoxicity plays a role in AD septal degeneration and hippocampal dysfunction. To demonstrate the presence of excitotoxicity in Aβ-induced septal damage, we compared rats injected with Aβ1-40 into the MS/DB with animals treated with memantine prior, during and after Aβ1-40 injections. Controls were injected with phosphate buffered saline (PBS). MS/DB cholinergic, glutamatergic and GABAergic neurons were immunochemically identified. The number of MS/DB neurons was estimated using stereology. Our results show that memantine blocks Aβ1-40-induced septal damage and suggest that excitotoxicity plays a role in basal forebrain neurodegeneration

Memantine protects cholinergic and glutamatergic septal neurons from Aβ1-40-induced toxicity

The medial septal region (medial septum and diagonal band of Broca, MS/DB) controls hippocampal excitability and synaptic plasticity. MS/DB cholinergic neurons degenerate early in Alzheimer’s disease (AD). The presence of MS/DB glutamatergic neurons that project to the hippocampus and are vulnerable to Aβ suggests that excitotoxicity plays a role in AD septal degeneration and hippocampal dysfunction. To demonstrate the presence of excitotoxicity in Aβinduced septal damage, we compared rats injected with Aβ1–40 into the MS/DB with animals treated with memantine prior, during and after Aβ1–40 injections. Controls were injected with phosphate buffered saline (PBS). MS/DB cholinergic, glutamatergic and GABAergic neurons were immunochemically identified. The number of MS/DB neurons was estimated using stereology. Our results show that memantine blocks Aβ1–40-induced septal damage and suggest that excitotoxicity plays a role in basal forebrain neurodegeneration

Determination of Physical and Mechanical Properties of Three-layer Boards of Teak (Tectona grandis), Seike (Cedrelinga catenaeformis) and Mascarey (Hieronima alchorneoides), Company PISMADE S.A., Riobamba Canton, Chimborazo Province

The present investigation aims to determine the physical and mechanical properties in three-layer boards of Teak (Tectona grandis), Seike (Cedrelinga catenaeformis) and Mascarey (Hieronima alchorneoides), from the PISMADE S.A. Company, Canton Riobamba, province of Chimborazo. The three specimens used for each of the species in each of the tests performed were worked on using the ASTM D143-94 standard for the tests of parallel compression, perpendicular compression and flexion, and the DIN-52182 standard, with the main variation in thickness measurements caused by the commercial use established by the company. Mechanical tests showed that Seike had the best results, being superior in two tests: perpendicular compression and flexion. Teak tests gave us results that were superior in the perpendicular compression test. Mascarey, unlike the two species mentioned above, had complications during the trials due to problems with the glue between layers. Keywords: physical and mechanical properties of wood, three-layer boards. Resumen La presente investigación pretende: Determinar las propiedades físicas y mecánicas en tableros tricapa de Teca, Seike (Cedrelinga catenaeformis) y Mascarey (Hyeronima alchorneoides), Empresa PISMADE S.A., cantón Riobamba, provincia de Chimborazo; para lo cual se utilizaron 3 probetas por cada una de las especies en cada uno de los ensayos realizados, las mismas fueron trabajadas con base a la Norma ASTM D143-94 para las pruebas de compresión paralela, compresión perpendicular y flexión y la Norma DIN-52182, teniendo como principal variación en las medidas de espesor debido al uso comercial establecido por la empresa. Las pruebas mecánicas mostraron que Seike tuvo los mejores resultados al ser superior en dos ensayos: Compresión perpendicular y flexión. Los ensayos con Teca nos dieron como resultados que es superior en el ensayo de compresión perpendicular. Mascarey a diferencia de las dos especies mencionadas anteriormente tuvo complicaciones con los ensayos debido a problemas con el pegamento entre capas. Palabras clave: propiedades físicas y mecánicas de la madera, tableros tricapa

Participation of the leading representatives of the community in the CLAS of Chiclayo, Lambayeque, September - December, 2007

Los Comités locales de administración en salud (CLAS) son instituciones legales privadas, no lucrativas; administradas por siete miembros que forman la asamblea general. El propósito del estudio fue determinar el nivel de participación de los líderes en los CLAS de Chiclayo - Perú,durante el periodo septiembre - diciembre 2007. Los datos fueron obtenidos a través de un cuestionario, en relación a las normas dadas para el funcionamiento de los CLAS, los que fueron procesados con Microsoft Excel. Los resultados indican que el buen funcionamiento de los CLAS se rigen por la actitud de involucramiento de sus miembros, comprometidos en la promoción de los principios esenciales de la administración compartida; sin embargo, se encontró una debilidad en los integrantes que es la indiferencia. Es escasa la capacidad logística para enfrentar el reto. El tiempo de dedicación y el nivel de educación, está relacionada con el dinamismo y el desarrollo de sus funciones. El 56,94% de los represenatantes tienen secundaria completa, hecho que influye en su participación y en la calidad de sus ideas. Se concluye que mejor funcionamiento como asociación presentó el CLAS de Monsefú, mientras que el CLAS con menor grado de participación es Oyotún. Asimismo, se concluye que existe relación entre el nivel de instrucción y el aporte de ideas de los miembros que integran los CLAS.Abstract : The local Committees of health administration (CLAS) are legal, private, non-lucrative institutions; administered by seven members who conform the general assembly. The purpose of the study was to determine the level of participation of the leaders in the CLAS of Chiclayo - Peru, during September - December, 2007. The data was obtained from a ques-tionnaire in relation to legal norms for the functioning of CLAS, which was procesed with Microsoft Excel. The results indicate that the good functioning of the CLAS depends upon the attitude of involvement of its members, engaged in promoting the basic principles of shared administration; however a weakness in the members was found indiffe rence. There is a limited logistical capacity to confront the challenge. The time commitment and the instruction level are related to the dynamism and development of their functions. 56.94% of the representatives have complete High School studies, which is related to their participation and the quality of their ideas during the meetings. We concluded that CLAS Monsefú shows a better functioning, while Oyotún is the CLAS with the lesser degree of participation. Also, we concluded that there is a relationship between the instruction level and the ideas given by members during their meetings