Fondazione CRT

The relationship between city and country is an old, recurring topic. In this article, we analyse this relation by examining a set of manifestos drawn up in Catalonia between 1976 and 2013, calling for environmental protection, with a particular regard to agriculture. On the basis of these documents, we reflect on the critical state of agriculture in contemporary urban societies and on the development of new environmental cultures. The article introduces manifestos as documents that can be used to analyse a population’s interpretations of contemporary problems, in addition to social and environmental processes, and examines the place of these manifestos in, and their relationship with Catalonia’s urban systems. Our analysis of these manifestos highlights the cultural shift that is currently occurring in many Western urban societies in relation to the environment, agriculture and food.

We show that some of the Josephson couplings of junctions arranged to form an inhomogeneous network undergo a non-perturbative renormalization provided that the network's connectivity is pertinently chosen. As a result, the zero-voltage Josephson critical currents Ic turn out to be enhanced along directions selected by the network's topology. This renormalization effect is possible only on graphs whose adjacency matrix admits a hidden spectrum (i.e. a set of localized states disappearing in the thermodynamic limit). We provide a theoretical and experimental study of this effect by comparing the superconducting behaviour of a comb-shaped Josephson junction network and a linear chain made with the same junctions: we show that the Josephson critical currents of the junctions located on the comb's backbone are bigger than those of the junctions located on the chain. Our theoretical analysis, based on a discrete version of the Bogoliubov–de Gennes equation, leads to results which are in good quantitative agreement with experimental results.