Apart from this, the regional distribution is fairly even, but nevertheless signifies a centre-periphery pattern when overlooking the Oslo region.
For all three periods, other larger urban regions demonstrate the highest levels of activity, and if we overlook the capital region a centre-periphery pattern appears as the relative number of projects are smallest in the most peripheral areas.
Assuming such a despotic mechanism of colony formation, one would expect a central-periphery pattern of distribution where the phenotypic quality of breeding birds declines from the centre towards the edges of a colony (Coulson 1968).
Such investment decisions, however, also lead to a vicious circle: improving the accessibility of the central zones draws new activities to these zones, reinforcing their central role, their attractiveness for additional future investments, and resulting in core-periphery patterns.
Since the location of each zone could influence the measures of the mentioned sub-indicators (core-periphery patterns), the article also explores two different approaches trying to construct an accessibility composite indicator, thought as a synthetic parameter embracing all the complementary information delivered by the other four 'partial' accessibility measures.
Since the results suggest that the location of each zone (core-periphery patterns) could influence the measures of the various accessibility indicators, the article has also evaluated two different approaches (DEA and BOD) to create a composite accessibility index embracing all the complementary information delivered by the other four 'partial' accessibility measures.
Figure 2 reports the location index for each NUT3 zone in Europe and for each simulated scenario showing clearly the above described core-periphery patterns; as expected the scenarios with maximum speed of 45 km/h or minimum speed of 200 km/h on the whole railway network present respectively the highest and lowest values of the location index.
By contrast, heterogeneous habitats were found to disrupt the central-periphery patterns of distribution within colonies.
These were mainly ground-nesting larids and spheniscids, where clear central-periphery patterns were recorded in ca. 80%% of the taxa.
Under such circumstances, the central-periphery patterns could be disrupted and pairs of varying quality could be distributed more or less uniformly among the central and peripheral zones of colonies.
