Despite a huge drop in people crossing into the US, some Americans are still grabbing weapons and patrolling the boundary with Mexico. Channel 4 News meets a lone vigilante on the border.

Frank Cottrell-Boyce and Cressida Cowell recommend a selection of children’s books.

What began with a focus on weather forecasting has evolved toward addressing errors in scientific modeling. In the collaborative environment of the Penn State Institute for Computational and Data ...