BY MUSHTAQUE CHOWDHURY   This piece was originally published in The Business Standard. It has been reposted below.   Pictured above: Mushtaque Chowdhury, left, and Richard Cash, right, chat among collaborators and peers on the Oral Rehydration Therapy program in Bangladesh. Photo courtesy of Mushtaque Chowdhury. Richard Alan Cash, a senior faculty of the Harvard … Continue reading Richard Cash: my friend and mentor