for helpful comments on earlier versions of this paper. This paper is a product of a research project on motorization and roads that is being carried out jointly by the Research Advisory Staff and the Transport, Water, and Urban Development Department.
Using panel data from 50 countries and 35 urban areas (both covering a wide range of country incomes), this paper summarizes trends in motorization, road provision, and road transport service production (combining vehicles and roads). The growth of both motorization and road provision is related to incomes, land area, population density, urbanization,… (More)
Adenylyl cyclase (AC), which produces the signalling molecule cAMP, has numerous important cellular functions in diverse organisms from prokaryotes to eukaryotes. Here we report the identification and characterization of an AC gene from the liverwort Marchantia polymorpha. The encoded protein has both a C-terminal AC catalytic domain similar to those of… (More)