Multilayer Networks and Mesoscale Structure
How can communities, flows and other intermediate-scale structures be identified when a system contains several kinds of interaction?
Highlights
From brain signals to meaningful networks
How can brain activity recordings reveal the interactions that distinguish subjects and characterise brain disorders?
The layered structure of global trade
How do commodity and industry layers organise international trade, and how do production shocks travel through it?
Research focus
Many systems contain several kinds of interaction and organise themselves at scales between individual nodes and the network as a whole. Multilayer models keep different relations distinct; community-detection and flow-based methods help reveal the resulting mesoscale organisation.
Our work has examined the community structure of multilayer systems, molecular networks, international trade and global value chains. The common question is which structural information is lost when heterogeneous relations are reduced to a single graph.
Molecular networks and biological function
Our study of the human proteome, with Giuseppe Jurman and Manlio De Domenico, keeps molecular interaction layers separate when identifying functional modules with Multiplex Infomap. Its random walker follows the links of its current layer and, with a probability called the relax rate, the links of any layer, which lets it move between layers. An information-theoretic criterion selects this rate.
Comparing the resulting modules with independently annotated gene sets assesses their biological relevance. The selected multilayer organisation has greater functional content than modules obtained from the aggregate representation, connecting a modelling choice to an external biological assessment.
Selected publications
- The nested structural organization of the worldwide trade multi-layer network, Scientific Reports (2019)
- Modularity in multilayer networks using redundancy-based resolution and projection-based inter-layer coupling, IEEE Transactions on Network Science and Engineering (2019)
- Multilayer flows in molecular networks identify biological modules in the human proteome, IEEE Transactions on Network Science and Engineering (2020)