“…In order to analyze the network tolerance we need to specify particular models within this general class. The so-called threshold model [15] is a simple case of heterogenous PA based on the assumption that the affinity between nodes is inversely related to the distance between their states as defined by a certain space metric. The rationale for this choice is that the inverse relationship between affinity and state distance may be a reasonable proxy for many real networks where PA can be considered as the most relevant linking mechanism, such as protein interactions, web page hyperlinks, scholar citations or social relationships.…”