Regionalised sprawl: conceptualising suburbanisation in the European context

Being recognised as the predominant urban pattern of the twenty-first century, suburbanisation is a global phenomenon that is characteristically regionalised: time- and site-specific factors and conditions differently shape its emergence in different locations. Post-suburbia and suburban governance are two analytical perspectives that are used to account for the global and regionalised character of suburbanisation. However, conceptualising suburbanisation in Europe should also more clearly encompass the role of spatial planning systems and the related actors’ sociopolitical configurations. We here propose an institutional, actor-centred conceptual framework accounting for spatial planning to more effectively analyse processes and patterns of European regionalised global suburbanisation.status: Published onlin

A Chemoattractant-mediated G(i)-coupled Pathway Activates Adenylyl Cyclase in Human Neutrophils

Neutrophils and Dictyostelium use conserved signal transduction pathways to decipher chemoattractant gradients and migrate directionally. In both cell types, addition of chemoattractants stimulates the production of cAMP, which has been suggested to regulate chemotaxis. We set out to define the mechanism by which chemoattractants increase cAMP levels in human neutrophils. We show that chemoattractants elicit a rapid and transient activation of adenylyl cyclase (AC). This activation is sensitive to pertussis toxin treatment but independent of phosphoinositide-3 kinase activity and an intact cytoskeleton. Remarkably, and in sharp contrast to Gα(s)-mediated activation, chemoattractant-induced AC activation is lost in cell lysates. Of the nine, differentially regulated transmembrane AC isoforms in the human genome, we find that isoforms III, IV, VII, and IX are expressed in human neutrophils. We conclude that the signal transduction cascade used by chemoattractants to activate AC is conserved in Dictyostelium and human neutrophils and is markedly different from the canonical Gα(s)-meditated pathway