The Proterozoic Eon, spanning from 2,500 million to 539 million years ago, marked a transformative chapter in Earth's history. Often overshadowed by the more data-rich Phanerozoic Eon, this period ...

Around 1900 many American educators advocated the use of objects in teaching mathematics and the sciences. R. O. Evans Company of Chicago published this set of twenty chromolithographed charts. They ...

Urine drug test (UDT) data can generate timely estimates of overdose deaths, a new study suggests.. The study, published in JAMA Network Open by specialty lab Millennium Health and The Ohio State ...