Dear friends in the quantum information and foundations communities,
Many of you may not know it, but the concept of a generalized quantum measurement or positive-operator-valued measure was introduced in
E. B. Davies and J. T. Lewis, "An Operational Approach to Quantum Probability," Communications in Mathematical Physics 17, 239-260 (1970).
Last night, John Lewis passed away here in Dublin, his home of 28 years, from complications due to a recent surgery. He was a good man, honest and upright, and left us a deep legacy. He will be missed.