100 days without COVID-19: how New Zealand got rid of a virus that keeps spreading across the world
New Zealand is among a bare handful of countries which have avoided community spread of the COVID-19 coronavirus. Here's how they did it.
global
5 reasons Chinese students may stop studying in the US
A loss of Chinese students from the US - and the US$15 billion they spend on tuition - could have serious repercussions for American colleges and universities.
What is ammonium nitrate, the chemical that exploded in Beirut?
For combustion to occur, oxygen must be present. Ammonium nitrate prills provide a much more concentrated supply of oxygen than the air around us.
How other countries reopened schools during the pandemic – and what the US can learn from them
Nearly every country in the world shuttered its schools due to COVID-19. Now, from Israel to Uruguay, many students are back in class, with varying degrees of success.
Critics: Changing information about coronavirus transmission, impact leads to backlash over policy decisions
As more is learned about the COVID-19 coronavirus, health officials are changing guidance, leading to public frustration and mistrust.
The WHO often has been under fire, but no nation has ever moved to sever ties with it
The WHO is a health agency, not a political one. Yet political leaders have often criticized it. Still, the move by the US to pull out from the organization is unprecedented.
Aerosols are a bigger coronavirus threat than WHO guidelines suggest – here's what you need to know
Nanoparticles dressed up in cell membranes snag SARS-CoV-2 virus particles before they reach human cells.
U.S. to withdraw from World Health Organization
In the midst of the COVID-19 coronavirus pandemic, United States President Donald Trump has decided to withdraw the country from the World Health Organization.
Mexico closes border before holiday weekend
The border between Arizona and Sonora, Mexico, has been closed starting Saturday, to help slow the spread of the COVID-19 coronavirus pandemic.
100 degrees in Siberia? 5 ways the extreme Arctic heat wave follows a disturbing pattern
The Arctic heat wave that sent Siberian temperatures soaring to around 100 degrees Fahrenheit on the first day of summer put an exclamation point on an astonishing transformation of the Arctic environment that's been underway for about 30 years.