Compound orbits break-up in constituents: an algorithm

In this paper decomposition of periodic orbits in bifurcation diagrams are derived in unidimensional dynamics system $x_{n+1}=f(x_{n};r)$, being $f$ an unimodal function. We proof a theorem which states the necessary and sufficient conditions for the break-up of compound orbits in their simpler constituents. A corollary to this theorem provides an algorithm for the computation of those orbits. This process closes the theoretical framework initiated in (Physica D, 239:1135--1146, 2010)

Redefining the role of obstacles in pedestrian evacuation

The placement of obstacles in front of doors is believed to be an effective strategy to increase the flow of pedestrians, hence improving the evacuation process. Since it was first suggested, this counterintuitive feature is considered a hallmark of pedestrian flows through bottlenecks. Indeed, despite the little experimental evidence, the placement of an obstacle has been hailed as the panacea for solving evacuation problems. In this work, we challenge this idea and experimentally demonstrate that the pedestrians flow rate is not necessarily altered by the presence of an obstacle. This result - which is at odds with recent demonstrations on its suitability for the cases of granular media, sheep and mice - differs from the outcomes of most of existing numerical models, and warns about the risks of carelessly extrapolating animal behaviour to humans. Our experimental findings also reveal an unnoticed phenomenon in relation with the crowd movement in front of the exit: in competitive evacuations, an obstacle attenuates the development of collective transversal rushes, which are hazardous as they might cause falls.Fil: Garcimartín, A.. Universidad de Navarra; EspañaFil: Maza, D.. Universidad de Navarra; EspañaFil: Pastor, J. M.. Focke Meler Gluing Solutions S.A.; EspañaFil: Parisi, Daniel Ricardo. Instituto Tecnológico de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Martín Gómez, C.. Universidad de Navarra; EspañaFil: Zuriguel, I.. Universidad de Navarra; Españ

VISIR-VLT Images of the Water Maser Emitting Planetary Nebula K 3-35

K3-35 is an extremely young bipolar planetary nebula that contains a precessing bipolar jet and a small (radius 80 AU) water maser equatorial ring. We have obtained VISIR- VLT images of K 3-35 in the PAH1 ({\lambda}=8.6 {\mu}m), [S iv] ({\lambda}=10.6 {\mu}m), and SiC ({\lambda}=11.85 {\mu}m) filters to analize the mid-IR morphology and the temperature structure of its dust emission. The images show the innermost nebular regions undetected at optical wavelegths and the precessing bipolar jets. The temperature map shows variations in the temperature in the equatorial zone and in regions associated to its jets.Comment: 2 pages, 2 figures, 283 IAU Symp. Planetary Nebulae an Eye to the Futur

Distinguishing noise from chaos: objective versus subjective criteria using Horizontal Visibility Graph

A recently proposed methodology called the Horizontal Visibility Graph (HVG) [Luque {\it et al.}, Phys. Rev. E., 80, 046103 (2009)] that constitutes a geometrical simplification of the well known Visibility Graph algorithm [Lacasa {\it et al.\/}, Proc. Natl. Sci. U.S.A. 105, 4972 (2008)], has been used to study the distinction between deterministic and stochastic components in time series [L. Lacasa and R. Toral, Phys. Rev. E., 82, 036120 (2010)]. Specifically, the authors propose that the node degree distribution of these processes follows an exponential functional of the form $P(\kappa)\sim \exp(-\lambda~\kappa)$, in which $\kappa$ is the node degree and $\lambda$ is a positive parameter able to distinguish between deterministic (chaotic) and stochastic (uncorrelated and correlated) dynamics. In this work, we investigate the characteristics of the node degree distributions constructed by using HVG, for time series corresponding to $28$ chaotic maps and $3$ different stochastic processes. We thoroughly study the methodology proposed by Lacasa and Toral finding several cases for which their hypothesis is not valid. We propose a methodology that uses the HVG together with Information Theory quantifiers. An extensive and careful analysis of the node degree distributions obtained by applying HVG allow us to conclude that the Fisher-Shannon information plane is a remarkable tool able to graphically represent the different nature, deterministic or stochastic, of the systems under study.Comment: Submitted to PLOS On

Universidad de Navarra = 0 CO2

Un proyecto académico, realizado por alumnos de la Escuela de Arquitectura de la Universidad de Navarra durante el curso 2008-2009, derivó en una ambiciosa actuación propositiva para que en el Campus de la Universidad de Navarra en Pamplona se minimizaran las emisiones de CO2. Las ideas propuestas incluyen acciones relacionadas con el transporte, la gestión del agua, la gestión de residuos,… Es objeto de esta comunicación exponer la metodología seguida en el proyecto, así como los principales resultados obtenidos en distintas áreas

The building stone of the Roman city of Lixus (NW Morocco): provenance, petrography and petrophysical characterization

The characterization of building materials is a key tool to assess deterioration processes and improve potential restoration works of archaeological sites. The aim of this paper is to identify and characterize the most important building stones used in the construction of the Roman city of Lixus (Larache, Morocco) by means of petrographic and petrophysical techniques. Based on the visual analysis of the monuments, three major building stones (i.e. lithotypes) have been identified: i) Oligocene sandstones, ii) Quaternary sandstones and iii) Quaternary conglomerates. Based on the analysis of the regional geology and exploitation marks, these three lithotypes have been recognised to crop out in the surroundings of Lixus and the quarries, presumably Roman in origin, recognized. The Oligocene sandstone is the primary building stone in Lixus as it forms and crops out extensively in the Tchemmis hill, at the top of which the city is settled. The Quaternary sandstones and conglomerates, which represent nearshore deposits and eolianites, crop out along the Atlantic coast where they form part of the cliffs next to Larache. Petrographic results indicate that lithotypes differ notably in grain size, ratio of detrital to allochemical components, and the configuration of their porous system. Mechanical analysis shows that the Oligocene sandstones are more resistant to compression than the Quaternary sandstones and conglomerates, the latter exhibiting relatively low compressive strength. The Oligocene sandstones, which display scarce porosity and permeability, show a hydric behaviour characterized by a very low degree of absorption and desorption water, likely resulting from a poor connectivity of the pore network. Contrary to the latter lithotype, the Quaternary sandstones, which exhibit very high porosity and permeability, display a hydric behaviour characterized by high degree of both absorption and desorption of water. This is attributed to the low degree of cementation compared to porosity of this lithotype and the excellent connectivity of the porous network. Finally, Oligocene and Quaternary sandstones do not show a significant weight loss after the accelerated artificial aging test, indicating that both are slightly affected by salt crystallization and presumably ice formation. Results indicate that the relatively fine state of conservation of the building rocks of Lixus is linked to intrinsic factors such as mineralogy and petrophysical characteristics together with the favourable effect of the climatic condition of the study area

Perfiles de supervivencia ajustados mediante modelos lineales y de weibull: estimando estructuras estables y estacionarias para poblaciones de ungulados del pleistoceno

Los perfiles de supervivencia y de mortalidad de mamíferos pueden proporcionar información sobre el contexto ambiental de localidades arqueopaleontológicas del Pleistoceno, así como, sobre los agentes implicados en los procesos de formación del yacimiento. El contexto ambiental y la disponibilidad de carne eran factores relevantes para determinar los asentamientos humanos en Europa durante el Pleistoceno. Por esta razón, profundizar en la paleoecología de comunidades de grandes mamíferos puede proporcionar información clave sobre la evolución humana y patrones de dispersión. En este estudio comparamos dos aproximaciones matemáticas que permiten reconstruir perfiles de supervivencia y de mortalidad de grandes mamíferos y sus estructura de edad: el modelo lineal y el modelod e Weibull. Ambos aproximaciones proporcionan resultados similares para todas las especies de grandes mamíferos analizadas. El coeficiente de correlación más bajo fue para Bison bison (0.789), pero la diferencia en biomasa estimada entre los modelos se reduce a menos del 2%. Cuando ambas metodologías fueron comparadas a nivel de comunidad en los yacimientos de Orce, los índices ecológicos usados para comparar las metodologías también mostraron diferencias de menos del 2%. Dadas la similitudes en las salidas de los modelos, proponemos un uso preferencial del modelo de Weibull por su potencia y mayor facilidad de computación en comparación con el modelo lineal. Además, los parámetros λ y k del modelo de Weibull aportan información sobre la fertilidad y la madurez de las estructuras de población, siendo útiles para diferenciar entre estrategias reproductivas de las especies comparadas. Por tanto, nuestros resultados apoyan que el modelo de Weibull es una herramienta valiosa para investigar la disponibilidad de recursos cárnicos y el nivel de competencia entre los carnívoros en las comunidades de grandes mamíferos europeas del Pleistoceno en las que vivieron los humanos.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Modeling mammals food webs in the Orce sites: Quantitative reconstruction of prey-predator relationships for the first humans of Western Europe

The meat was a relevant trophic resource for the first hominin dispersal in Europe during Early Pleistocene times. Moreover, meat availability could have conditioned human presence due to the intensity of competition with other carnivores for the access to these resources. From this point of view, it is very interesting to test past ecosystems which have fossil records before and after human presence. The Early Pleistocene sites of Orce (Baza Basin, Spain) offer a unique opportunity to analyze the food webs of the mammalian paleocommunities. With an age of 1.6-1.5 Ma and absence of evidence on human presence, the Venta Micena (VM) site provides the scenery before the initial peopling. In contrast, Barranco León (BL) and Fuente Nueva-3 (FN3), dated at around 1.4 Ma, preserve evidence of human presence. The latter sites have provided huge large mammals assemblages with an excellent state of preservation, which has allowed carrying out a number of taphonomic, geochemical isotopic and paleoecological analyses, contextualizing the environmental condition of the first human settlements in Western Europe. For this reason, it is very interesting to reconstruct the Orce food webs for estimating how meat availability could have influenced their structure. In this study, we have applied a mathematical approach based on Leslie matrices to quantify the biomass of large mammals available to the guild of secondary consumers, including humans in BL and FN3, in order to analyze the pattern of meat distribution and intraguild competition. The results for the Orce food webs showed that meat was not the main limiting factor to hominin presence in Western Europe before 1.4 Ma.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Modeling at farm level: Positive Multi-Attribute Utility Programming

This article proposes a new mathematical programming model for the simulation of farmers’ decision-making. We have developed a model based on a multi-attribute utility approach that takes into consideration the most relevant attributes of farmers within a positive framework. This approach overcomes the limitations found in some mathematical models used in the literature to simulate farmers’ behavior. A five-step procedure is presented in order to elicit the utility function that reproduces farmers’ current decision-making. We illustrate this positive multi-attribute approach using a sample of farmers in an irrigated area in southern Spain, where our simulations demonstrate the accurateness of the model in reproducing actual farmers’ decision-making. We also find evidence that the model is able to explain the heterogeneous behavior of farmers within a homogeneous agricultural syste