Radioactive elements are produced in nature and scientific experiments.

He was diagnosed with bipolar disorder.

This software has forward compatibility.

This software maintains backward compatibility.

He was diagnosed with congestive heart failure.

The success of this project is influenced by a lot of uncertainty.

He is receiving treatment for obsessive-compulsive disorder.

The sexology class is very interesting.

In mathematics, it is important to examine the parity of numbers.

Sex chromosomes play a crucial role in determining the sex of an organism.