Scientists at Northwestern University in the US have determined the molecular structure of a viral protein, the parainfluenza virus 5 fusion (F) protein. The parainfluenza virus 5 is part of a family of viruses (paramyxoviruses) that causes everything from pneumonia, croup and bronchiolitis to cold-like illness and is responsible for many hospitalizations and deaths each year. The results are published in the Jan. 5 issue of the journal Nature. Also, check out our how to avoid colds and flu page for advice on sidestepping viruses.