Sums of variables at the onset of chaos

We explain how specific dynamical properties give rise to the limit distribution of sums of deterministic variables at the transition to chaos via the period-doubling route. We study the sums of successive positions generated by an ensemble of initial conditions uniformly distributed in the entire phase space of a unimodal map as represented by the logistic map. We find that these sums acquire their salient, multiscale, features from the repellor preimage structure that dominates the dynamics toward the attractors along the period-doubling cascade. And we explain how these properties transmit from the sums to their distribution. Specifically, we show how the stationary distribution of sums of positions at the Feigebaum point is built up from those associated with the supercycle attractors forming a hierarchical structure with multifractal and discrete scale invariance properties.Comment: arXiv admin note: text overlap with arXiv:1312.071

Violent Conflict and Human Development in Latin America: The Cases of Colombia, El Salvador and Guatemala

human development, aid, trade, security

A Reassesment of Flexible Price Evidence Using Scanner Data: Evidence from an Emerging Economy

In this paper we use a new database of scanner-level prices for the Chilean economy to characterize the microeconomic behavior of prices during a period of high inflation. We are able to characterize the price-setting behavior by supermarket chain. The evidence indicates that there is significant heterogeneity in the pricing behavior of individual retailers. Analyzing the source of shocks, results show that even though chain-specific shocks account for a sizable fraction of the observed variation, common (i.e. countrywide) shocks to individual goods and product categories are the most important factors to explain the behavior of prices. In other words, the pricing strategy of retailers seems less important in developing countries to explain microeconomic price dynamics.

Scaling of distributions of sums of positions for chaotic dynamics at band-splitting points

The stationary distributions of sums of positions of trajectories generated by the logistic map have been found to follow a basic renormalization group (RG) structure: a nontrivial fixed-point multi-scale distribution at the period-doubling onset of chaos and a Gaussian trivial fixed-point distribution for all chaotic attractors. Here we describe in detail the crossover distributions that can be generated at chaotic band-splitting points that mediate between the aforementioned fixed-point distributions. Self affinity in the chaotic region imprints scaling features to the crossover distributions along the sequence of band splitting points. The trajectories that give rise to these distributions are governed first by the sequential formation of phase-space gaps when, initially uniformly-distributed, sets of trajectories evolve towards the chaotic band attractors. Subsequently, the summation of positions of trajectories already within the chaotic bands closes those gaps. The possible shapes of the resultant distributions depend crucially on the disposal of sets of early positions in the sums and the stoppage of the number of terms retained in them

Scaling laws of quiet-Sun coronal loops

We study a series of relations between physical parameters in coronal loops of the quiet Sun reconstructed by combining tomographic techniques and modeling of the coronal magnetic field. We use differential emission measure tomography (DEMT) to determine the three-dimensional distribution of the electron density and temperature in the corona, and we model the magnetic field with a potential-field source-surface (PFSS) extrapolation of a synoptic magnetogram. By tracing the DEMT products along the extrapolated magnetic field lines, we obtain loop-averaged electron density and temperature. Also, loop-integrated energy-related quantities are computed for each closed magnetic field line. We apply the procedure to Carrington rotation 2082, during the activity minimum between Solar Cycles 23 and 24, using data from the Extreme Ultraviolet Imager on board the Solar Terrestrial Relations Observatory (STEREO) spacecraft. We find a scaling law between the loop-average density N and loop length L,Nm∼L-0.35, but we do not find a significant relation between loop-average temperature and loop length. We confirm though the previously found result that loop-average temperatures at the equatorial latitudes are lower than at higher latitudes. We associate this behavior with the presence at the equatorial latitudes of loops with decreasing temperatures along their length (“down” loops), which are in general colder than loops with increasing temperatures (“up” loops). We also discuss the role of “down” loops in the obtained scaling laws of heating flux versus loop length for different heliographic latitudes. We find that the obtained scalings for quiet-Sun loops do not generally agree with those found in the case of AR loops from previous observational and theoretical studies. We suggest that to better understand the relations found, it is necessary to forward model the reconstructed loops using hydrodynamic codes working under the physical conditions of the quiet-Sun corona.Fil: Mac Cormack, Cecilia. Universidad Nacional de Tres de Febrero; Argentina. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Lopez Fuentes, Marcelo Claudio. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Mandrini, Cristina Hemilse. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Lloveras, Diego Gustavo. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Poisson, Mariano. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina. Universidad Nacional de Tres de Febrero; ArgentinaFil: Vasquez, Alberto Marcos. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina. Universidad Nacional de Tres de Febrero; Argentin

Evaluacion de la captura de insectos no blanco en nuevos disenos y cebos de trampas para adultos de la polilla de la manzana (Cydia pomonella) en un huerto de manzana de la region del Maule

29 p.El uso de distintas trampas y cebos para el monitoreo de la polilla de la manzana (Cydia pomonella) ha evolucionando durante estos últimos años, con los cuales se busca lograr atraer tanto machos como hembras. Uno de los nuevos cebos utilizados es el éster de pera en conjunto con ácido acético; además el éster de pera en combinación con feromonas sexuales, con los cuales se ha permitido obtener buenos resultados en la captura de machos y hembras. Sin embargo una de las problemáticas de estas nuevas trampas son los insectos no blanco que estos cebos pueden capturar, ya que existen diversos reportes de insectos no blanco capturados por estas trampas y cebos. Debido a esto se dispuso en el huerto las cinco configuraciones cebo-trampa (Trampas blancas cebadas con feromona sexual, trampas blancas cebadas con feromona sexual y éster de pera, trampas naranjas cebadas con feromona sexual y éster de pera trampas delta transparente cebada con éster de pera y ácido acético y trampas cilíndricas transparente cebadas con éster de pera y ácido acético) en un huerto de manzana abandonado, donde se evaluaron las capturas de insectos no blanco, durante la temporada 2009-2010. Dándonos como resultado que el color de las trampas es más importante que los cebos utilizados para la captura de insectos no blanco. Las trampas de color blanco, cebadas con feromona sexual sola y cebadas con éster de pera y feromona sexual en conjunto,capturaron un mayor número de himenópteros. Por el contrario, las trampas transparentes capturaron significativamente más hemípteros y dípteros lo que nos podría indicar que el ácido acético podría influenciar la captura de esos insectos. La trampa naranja capturó niveles bajos de himenópteros y dípteros, e intermedios de hemípteros por lo que desde el punto de vista de la captura de insectos no blanco sería la más recomendable para el monitoreo de Cydia pomonella./ ABSTRACT:The use of different traps and lures to attract males and females of the codling moth (Cydia pomonella) has changed in the last years. Some of the new baits used are pear ester with the sexual pheromone (codlemone) and the incorporation of acetic acid in orange and transparent delta traps, which have shown good results in the capture of males and females. However, one problem of these new traps and lures is the capture of non-target insects. In this work new trap designs and lures were evaluated to evaluate the capture of non-target insects in an abandoned apple orchard at Escuela Agrícola de Colín (Talca, Región del Maule), during the 2009-2010 season. The following traps and lures were used: i) transparent delta trap with pear ester and acetic acid, ii) transparent round trap with pear ester and acetic acid, iii) white delta trap with codlemone, iv) white delta trap with codlemone and pear ester, and v) orange delta trap with codlemone and pear ester. Non-target insect capture was more affected by trap color than by lures. White traps, either with codlemone or with pear ester and codlemone, captured a higher number of Hymenoptera. On the contrary, transparent traps with pear ester and acetic acid captured significantly more Hemiptera and Diptera. Orange delta traps with pear ester and codlemone captured few Hymenoptera and Diptera, and intermediate levels of Hemiptera. Therefore, form the point of view of reduced catches of non-target insects the orange delta trap with pear ester and codlemone is more suitable for Cydia pomonella monitoring

Renormalization group structure for sums of variables generated by incipiently chaotic maps

We look at the limit distributions of sums of deterministic chaotic variables in unimodal maps and find a remarkable renormalization group (RG) structure associated to the operation of increment of summands and rescaling. In this structure - where the only relevant variable is the difference in control parameter from its value at the transition to chaos - the trivial fixed point is the Gaussian distribution and a novel nontrivial fixed point is a multifractal distribution that emulates the Feigenbaum attractor, and is universal in the sense of the latter. The crossover between the two fixed points is explained and the flow toward the trivial fixed point is seen to be comparable to the chaotic band merging sequence. We discuss the nature of the Central Limit Theorem for deterministic variables.Comment: 14 pages, 5 figures, to appear in Journal of Statistical Mechanic

Ecología de los significados de los objetos matemáticos intervinientes en la resolución de problemas de ecuaciones diferenciales

Presentamos un análisis ecológico de los objetos intervinientes, sus significados y su relación con las dificultades para resolver problemas utilizando ecuaciones diferenciales. Esto bajo el Enfoque Ontológico-Semiótico (EOS). Este análisis muestra que la posibilidad de entender un proceso está asociada a la significación que tienen los elementos que intervienen y a las diferentes formas de representarse. Un objeto matemático tiene sentido alrededor de otros objetos. Debido al carácter epistémico de la investigación se utilizó una metodología cualitativa. Se abordaron casos de estudiantes que cursaban ecuaciones diferenciales en la Facultad de Ingeniería-Mexicali, dependiente de la Universidad Autónoma de Baja California, México

Caso clínico : agresividad por dominancia

De los perros que acuden a la consulta por trastornos de comportamiento, el problema más frecuente y preocupante es el de la agresividad. En este artículo se describe un caso de agresividad por dominancia en una perra mestiza de 2 años de edad. Este tipo de agresividad se manifiesta hacia las personas que conviven normalmente con el perro. Se trata de un caso estándar en el que se aporta un protocolo de diagnóstico y seguimiento a través de una amplia anamnesis y la elaboración de encuestas, así como un detallado programa de tratamiento.Out of all the dogs that are assisted in the consulting room because of problems in their behavior, the one which worries most and the commonest of all is aggression. In this article ít's described a case of dominant aggression in a two year oid mongrel. This type of aggression is normally projected on the owners of the animal. It's a standard case in which we give a protocol when suggesting the diagnosis, after that on observation through the results of a request, as well as a detailed treatment program