This week's stories show how fast attackers change their tricks, how small mistakes turn into big risks, and how the same old ...

Epithelial cells form a layer in which an apical surface is exposed to the external environment and to other forms of stress in ducts in specialized organs. As such, epithelial cells require robust ...

Adam Hayes, Ph.D., CFA, is a financial writer with 15+ years Wall Street experience as a derivatives trader. Besides his extensive derivative trading expertise, Adam is an expert in economics and ...

Carol M. Kopp edits features on a wide range of subjects for Investopedia, including investing, personal finance, retirement planning, taxes, business management, and career development. Somer G.