Home pregnancy tests that use colored streaks to indicate positive results may display an evaporation line (evap line). This is a colorless streak that occurs when urine dries on the test strip.

For our food systems, the rise of the honey bee has been an unqualified success. For our ecosystems, though, there is plenty ...

This week, the Curiosity rover found large carbon deposits on Mars, suggesting an ancient carbon cycle. Researchers exploring ...

The eccentrics of the new right aren’t rebelling against our political regime – they are its twisted successors.