Background Difference-in-differences is a method commonly used in population health research. It is based on assumptions that ...

When I was a kid, I was placed in special education. Recurrent ear infections had left me with a central auditory processing disorder, and the school’s verdict was that I needed to be sorted into the ...

The bees had to roll the ball under a blue "flower," then stand atop the moved object to access a sweet treat. Mikko Törmänen / University of Oulu Some bumblebees can spontaneously solve problems, a ...