Christopher Robertson said he would give the ACA "a solid B" because of its coverage expansions.
University of Arizona researchers found that the "sweet spot" for learning is 85%.
After two months of controlled drought, Biosphere 2's tropical rainforest is dancing in the rain once again.
"When the Earth Had Two Moons," a book by Erik Asphaug, a planetary geologist at the University of Arizona, is reviewed.
Discover Magazine named the first direct image of a black hole as its top story of 2019.
Jessica Tierney says this marriage of proxy records and models is a powerful tool for understanding past climates.
Dr. Dan Derksen discusses the relatively straightforward steps that could help improve conditions with the Indian Health Service.
Karina Salazar was among the researchers and activists nominated as an influencer in higher education admissions.
The work is technically brilliant, says evolutionary biologist Mike Worobey of the University of Arizona.