mediator with OWL

Hi

I am interested by references concerning recent results or work related to "mediators and OWL"

- theoritical issues : query language and query planing, hybrid language ruleML + OWL or subset, etc. 
- mediator systems designed using DAML+OIL (OWL orr subset) for the global ontology, for real applications

any help is welcome

Christine Golbreich