Seizure of the Bab el-Mandeb Strait complicates a widening conflict in the Persian Gulf. It also risks reigniting Yemen’s civil war.

New satellite methods can track penguin colonies in winter – and can judge their health based on the colour of their guano.

The African shoreline is now much more valuable to outsiders who want to monitor, contain or outflank the waterway opposite them.

Classroom assessment is a major source of student stress. Research suggests redesigning assessments around psychological needs may improve well-being.