Multifractal Characteristics of Geomagnetic Field Fluctuations for the Northern and Southern Hemispheres at Swarm Altitude.

This paper explores the spatial variations of the statistical scaling features of low to high latitude geomagnetic field fluctuations at Swarm altitude. The data for this study comes from the vector field magnetometer onboard Swarm A satellite, measured at low resolution (1 Hz) for one year (from 9 March 2016, to 9 March 2017). We estimated the structure-function scaling exponents using the p-leaders discrete wavelet multifractal technique, from which we obtained the singularity spectrum related to the magnetic fluctuations in the North-East-Center (NEC) coordinate system. From this estimation, we retain just the maximal fractal subset, associated with the Hurst exponent H. Here we present thresholding for two levels of the Auroral Electrojet index and almost the whole northern and southern hemispheres, the Hurst exponent, the structure-function scaling exponent of order 2, and the multifractal p-exponent width for the geomagnetic fluctuations. The latter quantifies the relevance of the multifractal property. Sometimes, we found negative values of H, suggesting a behavior similar to wave breaking or shocklet-like propagating front. Furthermore, we found some asymmetries in the magnetic field turbulence between the northern and southern hemispheres. These estimations suggest that different turbulent regimes of the geomagnetic field fluctuations exist along the Swarm path.

Modeling interacting city traffic with finite acceleration and braking capacities.

Understanding the fundamental interactions in the complex behavior of one car moving in a sequence of traffic lights necessarily implies the inclusion of finite braking and accelerating capabilities. This characteristic is usually not considered in the standard cellular automaton models, where car interactions are the main concern. Therefore, here we develop a model which includes interactions and finite braking and accelerating capabilities, filling the gap between a standard cellular automaton model that considers car interactions but infinite braking and accelerating capabilities and the continuous one car model that includes finite braking and accelerating capabilities but does not consider, as the name indicates, car interactions. The proposed new model bridge these two seemingly different approaches in an effort to investigate how the traffic jams are produced. We found that, in the appropriate limits, we can reproduce the complex behavior of the one car continuous model and the dynamics close to the resonance induced by the interacting cars, forced by the traffic lights. In the processes of introducing car interactions, we observe how the average velocity decreases to finally obtain traffic jams, which are an emergent state in which the traffic lights control the generation of pulses of cars but do not control its average speed. This model is expected to improve our understanding of the complexity that appears in city traffic situations, as the finite braking and accelerating capabilities are necessary to describe the vehicle dynamics, the control strategy of traffic light synchronization, the motion of buses in segregated lights, and the whole urban design.

Time series analysis in earthquake complex networks.

We introduce a new method of characterizing the seismic complex systems using a procedure of transformation from complex networks into time series. The undirected complex network is constructed from seismic hypocenters data. Network nodes are marked by their connectivity. The walk on the graph following the time of succeeding seismic events generates the connectivity time series which contains, both the space and time, features of seismic processes. This procedure was applied to four seismic data sets registered in Chile. It was shown that multifractality of constructed connectivity time series changes due to the particular geophysics characteristics of the seismic zones-it decreases with the occurrence of large earthquakes-and shows the spatiotemporal organization of these seismic systems.

Modeling a bus through a sequence of traffic lights.

We propose a model of a bus traveling through a sequence of traffic lights, which is required to stop between the traffic signals to pick up passengers. A two dimensional model, of velocity and traveled time at each traffic light, is constructed, which shows non-trivial and chaotic behaviors for realistic city traffic parameters. We restrict the parameter values where these non-trivial and chaotic behaviors occur, by following analytically and numerically the fixed points and period 2 orbits. We define conditions where chaos may arise by determining regions in parameter space where the maximum Lyapunov exponent is positive. Chaos seems to occur as long as the ratio of the braking and accelerating capacities are greater than about ∼3.

Regular transport dynamics produce chaotic travel times.

In the hope of making passenger travel times shorter and more reliable, many cities are introducing dedicated bus lanes (e.g., Bogota, London, Miami). Here we show that chaotic travel times are actually a natural consequence of individual bus function, and hence of public transport systems more generally, i.e., chaotic dynamics emerge even when the route is empty and straight, stops and lights are equidistant and regular, and loading times are negligible. More generally, our findings provide a novel example of chaotic dynamics emerging from a single object following Newton's laws of motion in a regularized one-dimensional system.

Lagrangian coherent structures at the onset of hyperchaos in the two-dimensional Navier-Stokes equations.

We study a transition to hyperchaos in the two-dimensional incompressible Navier-Stokes equations with periodic boundary conditions and an external forcing term. Bifurcation diagrams are constructed by varying the Reynolds number, and a transition to hyperchaos (HC) is identified. Before the onset of HC, there is coexistence of two chaotic attractors and a hyperchaotic saddle. After the transition to HC, the two chaotic attractors merge with the hyperchaotic saddle, generating random switching between chaos and hyperchaos, which is responsible for intermittent bursts in the time series of energy and enstrophy. The chaotic mixing properties of the flow are characterized by detecting Lagrangian coherent structures. After the transition to HC, the flow displays complex Lagrangian patterns and an increase in the level of Lagrangian chaoticity during the bursty periods that can be predicted statistically by the hyperchaotic saddle prior to HC transition.

Traumatismo maxilofacial asociado a neumomediastino y enfisema de cuello. Revisión de la literatura y fisiopatología / Maxillofacial trauma associated with pneumomediastinum and neck emphysema. Revision of literature and pathophysiology

La extensión de un enfi sema facial sin neumotórax, hacia el cuello o el mediastino, secundario a un traumatismo maxilofacial, es de baja frecuencia. En la literatura se encuentran pocos casos referidos y su presencia obliga a descartar la ruptura de vísceras cérvico-tóraco-abdominales. De un total de 744 pacientes con traumatismo facial ingresados en el Sanatorio del Norte de San Miguel de Tucumán, desde octubre de 1996 a septiembre de 2001, 57 pacientes presentaron enfi sema facial, 4 asociados a fractura de mandíbula, 3 a traumatismos faciales cerrados y 50 a fracturas faciales del tercio medio y superior (maxilar superior, senos paranasales, malar, órbita, arco cigomático y frontal). De estos últimos, 3 que tenían fractura del seno maxilar, cursaron con enfi sema de cuello y uno de ellos además con enfi sema mediastinal. Se relata la evolución clínica, diagnósticos diferenciales, conducta terapéutica y teorías de la diseminación del aire hacia el mediastino. Se realiza, además, una revisión bibliográfi ca

The extension of the facial emphysema without pneumothorax, toward neck or the mediastinum area, secondary to a traumatism maxillofacial, it is low frequency. In the literature they are few referred cases and their presence forces to discard viscera rupture of the neck, thorax or abdominal region. About a total of 744 patients with facial traumatism entered in the Sanatorium del Norte, of San Miguel of Tucumán, from October of 1996 to September of 2001, 57 patients presented facial emphysema, 4 associated to jaw fracture, 3 at closed facial traumatisms and 50 to facial fractures of the upper third of facial region (maxillary superior, paranasal sinus, orbit, zigomatic bone, zigomatic arch and frontal bone). Three patients had fracture of maxillary sinus and neck emphysema, one of them also developed pneumomediastinum. The clinical evolution is related, diff erential diagnoses, therapeutic and theories of the dissemination of the air toward the mediastinum. Bibliographical revision is preformed in this presentation

Quantitative description of realistic wealth distributions by kinetic trading models.

Data on wealth distributions in trading markets show a power law behavior x(-)(1+alpha) at the high end, where, in general, alpha is greater than 1 (Pareto's law). Models based on kinetic theory, where a set of interacting agents trade money, yield power law tails if agents are assigned a saving propensity. In this paper we are solving the inverse problem, that is, in finding the saving propensity distribution which yields a given wealth distribution for all wealth ranges. This is done explicitly for two recently published and comprehensive wealth datasets.