Before revision:  A common picture that emerges out of analysing them all is that of a system growing over time, which becomes increasingly sparse , and whose URLanization at the mesoscopic level is characterised by the presence of a statistically-significant core-periphery structure.
After revision:  A common picture that emerges is that of a system growing over time, which becomes increasingly sparse , and whose URLanization at the mesoscopic level is characterised by the presence of a statistically-significant core-periphery structure.