The CEOs argue that the increase in vaccinations and the lifting of restrictions in other countries should make the Biden administration reconsider the policy for travelers.

It alleges that Trump, as a result of defendants' actions, has sustained losses of at least $24 million "and continuing to accrue, as well as the loss of existing and future business opportunities."

How do boa constrictors breathe while constricting their victims? A new study finds that snakes can switch which set of ribs they use to draw in air as they crush their meal before devouring it.

A roundup of key developments and the latest in-depth coverage of Russia's invasion of Ukraine.