Viana is definitely a Portuguese surname, derived from the place name (Viana do Castelo being the major city with that name). I've definitely never heard of it as a first name.
I suppose
Viviana (which is a somewhat modern name, Bebiana being the traditional form)
could be shortened to Viana, but it sounds counterintuitive: imagine calling a
Maximilian, Milian. The associations with the place are just too strong.
Nevertheless I doubt very much the woman in question was Brazilian or Portuguese, since it would be very unlikely for a person (especially a scientist) to go by a nickname in a professional context.
Florence Maud - Mary Valentine ("May") - Ada Imogen - Clementine Everly - Sophia Eleanor - Lucy Beatrice ("Lou") | Henry Valerian - Maxence George - Benedict Louis - Emory Willian - John Arthur ("Jack") - Frederick DarcyThis message was edited 2/5/2014, 10:30 AM