Formation of localized states in dryland vegetation: Bifurcation structure and stability

In this paper, we study theoretically the emergence of localized states of vegetation close to the onset of desertification. These states are formed through the locking of vegetation fronts, connecting a uniform vegetation state with a bare soil state, which occurs nearby the Maxwell point of the system. To study these structures we consider a universal model of vegetation dynamics in drylands, which has been obtained as the normal form for different vegetation models. Close to the Maxwell point localized gaps and spots of vegetation exist and undergo collapsed snaking. The presence of gaps strongly suggest that the ecosystem may undergo a recovering process. In contrast, the presence of spots may indicate that the ecosystem is close to desertification

Microfluidos: ¿cuánto hay de nuevo?

Microfluidic groups many branches of Physics ranging from Fluid Dynamics to Electronics and closely linked with Biology Sciences. Its interdisciplinary character is a distinctive feature, as the times we are living today. In the last ten years, along with the development of biotechnology, microelectronics, materials science and many others, the use of microfluidic devices has increased remarkably. Few scientists in Cuba have worked in topics related with Microfluidics; nevertheless, there is no reference in which this activity has been pointed out explicitly. This article aims to introduce some terms and divulge basic aspects of Microfluidics; besides this, another article will be published with most applications of Microfluidics that could be of interest for Cuba

“Daily resilience”: sustainable strategies for urban fringe in three medium-sized inner Spanish cities

Urban resilience has evolved in the last time into a wider scope, related not only to facing major challenges or risks but to managing the complexity of urban systems and their “metabolism”, looking for more sustainable strategies. Consequently, it can be a very useful concept for both big and smaller cities, which are facing everyday urban life challenges. In a global context in which the urban phenomenon continues to spread, this paper aims to set a concept of “low regime”, “low intensity” or “daily” resilience as a specific and essential strategy for medium-sized cities in order to fulfil their role in the global concert of cities, through the historical analysis along the last five decades of three medium-sized inner Spanish cities: Vitoria, Zaragoza and Valladolid.These three cities, the most populated and complex among the medium-sized inner Spanish cities, are also capitals of their respective regions (the Basque Country, Aragon and Castile and León), and they represent the transition from an expansive model, in particular in their respective urban fringe, to the “urban resilience agenda”. In the sixties and seventies, they experienced an impressive growth, both physical and demographic. Later, in the eighties and nineties, the moderation in the population growth rates did not also moderate their physical expansion, which moved to the surroundings of the cities, until this growth came to an abrupt end in 2007 due to the economic crisis. Coming from a quite similar and homogenous cultural and urban context, Vitoria, Zaragoza and Valladolid have been developing undifferentiated peripheries, disrespectful with the conditions of the territory, until they started to adopt tailored strategies so as to guarantee a sustainable growth in the future and avoid eventual menaces for their urban territory.These new strategies aim to ensure the resilience of their respective urban fringe, because this is where the urban development tensions concentrate, and consist of composing an own profile of action, learning from the history of the city itself and from the natural values of their surrounding territory, and also keeping in mind the scarcity of economic resources in these medium-sized cities compared to bigger ones. Step by step, the singular history of each city, its “genius loci”, emerges as a solid foundation for these new strategies.This paper concludes that this idea of own identity seems to be resilient, and reveals that it can express itself through different tools (green infrastructure, urban regeneration and territorial planning) which in these three cities have found a useful topic to articulate a new integrated strategy for the “metabolism” of urban fringe in water systems: the Salburua wetlands and Zadorra river in Vitoria, protagonists of its greenbelt; the Ebro river in Zaragoza, recovered for the city after Expo 2008; and the network of rivers, canals and irrigation ditches in Valladolid, which stand as axes of a better relationship with the territory. All of them represent low cost smart and natural strategies that emerge as replicable examples of what “daily resilience” means and offers to these kind of medium-sized cities