Regionalización de las migraciones residenciales interurbanas en Chile en el período 1997-2002

Los cambios de residencia interurbanos constituyen una manifestación de las interacciones entre ciudades de un sistema urbano. Los flujos migratorios conforman una red única y organizada, que emerge de las prácticas de los migrantes. La aplicación combinada de métodos de análisis de redes y análisis espacial a microdatos censales, ha permitido caracterizar la estructura de la red de flujos migratorios interurbanos en Chile en el quinquenio 1997-2002. Los resultados muestran que las migraciones residenciales interurbanas constituyen una red de flujos heterogéneos en cuanto a su magnitud y alcance espacial, pero su combinación genera una estructura jerarquizada y muy estable, compuesta por grupos de ciudades con fuertes interconexiones migratorias mutuas. La proximidad geográfica es uno de los factores más importantes que conforman esta estructura, junto con la dinámica territorial de la economía y la distribución y jerarquía de las infraestructuras de transportes y comunicaciones. Interurban residential changes are expressions of the interactions between cities of an urban system. Migratory flows shape a unique and organized network that emerges from the practices of migrants. An applied combination of network analysis and spatial analysis methods to census microdata has allowed characterizing the structure of the network of interurban migratory flows in Chile in the period 1997-2002. The results obtained show that interurban residential migrations shape a network of heterogeneous flows in terms of their magnitude and spatial extend. Nevertheless, their combination build a hierarchical and very stable structure, composed of groups of cities with strong reciprocal migratory interconnections. Geographical proximity is one of the most important factors shaping this structure, in addition to the territorial dynamics of the economy and the distribution and hierarchy of transport and communications infrastructures

Boolean dynamics revisited through feedback interconnections

Boolean models of physical or biological systems describe the global dynamics of the system and their attractors typically represent asymptotic behaviors. In the case of large networks composed of several modules, it may be difficult to identify all the attractors. To explore Boolean dynamics from a novel viewpoint, we will analyse the dynamics emerging from the composition of two known Boolean modules. The state transition graphs and attractors for each of the modules can be combined to construct a new asymptotic graph which will (1) provide a reliable method for attractor computation with partial information; (2) illustrate the differences in dynamical behavior induced by the updating strategy (asynchronous, synchronous, or mixed); and (3) show the inherited organization/structure of the original network’s state transition graph.publishe

High proportion of cactus species threatened with extinction

This is the author accepted manuscript. The final version is available from Nature Publishing Group via the DOI in this record.Consejo Nacional de Ciencia y Tecnologí

Bioinformed Performative Composite Structures: From biological micro-structures to material composites and articulated assemblies

This ongoing investigation aims to learn from nature novel material organizations and structural systems in order to develop innovative architectural system. We developed a multidisciplinary approach, using scientific analysis and design research and prototyping. We focus on the study of a \u93living fossil\u94 fish, whose armor system is so efficient it has remained almost unchanged for millions of years. We investigate its morphological characteristics, its structural properties, the assembly mechanisms and the underlying material properties in order to derive new principles to design new enhanced structural systems. We use micro computerized tomography and scanning electron microscopy to observe microstructures, parametric design to reconstruct the data into digital models and then several 3D printing technologies to prototype systems with high flexibility and adaptive capabilities, proposing new gradual material interfaces and transitions to embed performative capabilities and multifunctional potentials

Postsuburbia en Europe et en Amérique

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Qualitative modeling, analysis, and control of synthetic regulatory circuits

International audienceQualitative modeling approaches are promising and still underexploited tools for the analysis and design of synthetic circuits. They can make predictions of circuit behavior in the absence of precise, quantitative information. Moreover, they provide direct insight into the relation between the feedback structure and the dynamical properties of a network. We review qualitative modeling approaches by focusing on two specific formalisms, Boolean networks and piecewise-linear differential equations, and illustrate their application by means of three well-known synthetic circuits. We describe various methods for the analysis of state transition graphs, discrete representations of the network dynamics that are generated in both modeling frameworks. We also briefly present the problem of controlling synthetic circuits, an emerging topic that could profit from the capacity of qualitative modeling approaches to rapidly scan a space of design alternatives