The day opens with Sahel cease-fire enters day four.
Monitors report full compliance across three corridors; aid convoys reached Gao.
The 17-year-old from Lagos posted a perfect 42/42 at the International Mathematical Olympiad in Warsaw.
Marine biologists off Nova Scotia recorded a right whale singing a call last documented in 1996, a family memory, sung back.
Hyalinobatrachium mashpi discovered in the Chocó, the 158th glass frog known to science.