Paul Remington vice chair of the East of England Ambulance trust thanks Ms Ball for her hard work.
He said: “Maria spent many years leading the ambulance service and I would like to thank her for her dedication and commitment through what have been some challenging times.
"Maria oversaw the formation of this Trust, bringing together three disparate organisations into one service, and its subsequent development."
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A court's heard how a man accused of murdering his partner carried on with normal life in the days after he allegedly killed her.
An unusual species of bird is enjoying a winter vacation here in the UK, according to the RSPB charity.
Clearer spells will develop through the night, particularly in the east, with frost and perhaps some patchy fog.