However, PCR tests, which are more sensitive, detected the virus in the early days of infection.
The experimental fusion reactor sustained the temperatures for a record-breaking 17 minutes.
A supremely weird new video shows a goldfish driving a water-filled, motorized "car" to help scientists understand how they navigate on land.
A wildlife photographer in Israel spotted a murmuration of starlings flying in an incredible bent spoon shape. How do the birds do it?