macadam

Her reading includes If This Is A Man and Man's Search for Meaning - Primo Levi and Viktor Frankl's accounts of their incarceration in Nazi-run concentration camps during the Second World War - and Heather Dune Macadam's The Nine Hundred, which details the story of a group of young women who were the first Jews to be taken by official transport to Auschwitz.

That gave companies “abnormal power to push up prices’’ and pass higher costs along to consumers – clout they hadn’t had for decades, Simon MacAdam, senior global economist at Capital Economics, wrote last month.

So she and her daughter went into business together, opening a Portland shop on Southwest Macadam Avenue called Little Amsterdam.

Since then, it has been used more than 650 million times - and, Dr Macadam said, "we've never seen a reversion" back to dangerous poliovirus.

"The issue is they're genetically unstable," Dr Andrew Macadam, from the UK's National Institute for Biological Standards and Control, told BBC News.