Dr David Perlmutter is president of the Perlmutter Health Centre in Naples, Florida, and the co-founder and president of The Perlmutter Brain Foundation.

He is the recipient of numerous awards, including the Humanitarian of the Year Award from the American College of Nutrition and the Linus Pauling Award.

A frequent lecturer, he writes a blog at VanguardNeurologist.com and is a contributor to The Huffington Post. His previous books include Grain Brain and The Grain Brain Cookbook.

John Buchan was born in Perth. His father was a minister of the Free Church of Scotland; and in 1876 the family moved to Fife where in order to attend the local school the small boy had to walk six miles a day. Later they moved again to the Gorbals in Glasgow and John Buchan went to Hutchesons' Grammar School, Glasgow University (by which time he was already publishing articles in periodicals) and Brasenose College, Oxford.

His years at Oxford - 'spent peacefully in an enclave like a monastery' - nevertheless opened up yet more horizons and he published five books and many articles, won several awards including the Newdigate Prize for poetry and gained a First. His career was equally diverse and successful after university and, despite ill-health and continual pain from a duodenal ulcer, he played a prominent part in public life as a barrister and Member of Parliament, in addition to being a writer, soldier and publisher. In 1907 he married Susan Grosvenor, and the marriage was supremely happy. They had one daughter and three sons. He was created Baron Tweedsmuir of Elsfield in 1935 and became the fifteenth Governor-General of Canada, a position he held until his death in 1940. 'I don't think I remember anyone,' wrote G. M. Trevelyan to his widow, 'whose death evoked a more enviable outburst of sorrow, love and admiration.'

John Buchan's first success as an author came with Prester John in 1910, followed by a series of adventure thrillers, or 'shockers' as he called them, all characterized by their authentically rendered backgrounds, romantic characters, their atmosphere of expectancy and world-wide conspiracies, and the author's own enthusiasm. There are three main heroes: Richard Hannay, whose adventures are collected in The Complete Richard Hannay; Dickson McCunn, the Glaswegian provision merchant with the soul of a romantic, who features in Huntingtower, Castle Gay and The House of the Four Winds; and Sir Edward Leithen, the lawyer who tells the story of John MacNab and Sick Heart River, John Buchan's final novel. In addition, John Buchan established a reputation as an historical biographer with such works as Montrose, Oliver Cromwell and Augustus.