On this week’s show, freelance writer Christa Lesté-Lasserre talks with host Sarah Crespi about the scientists working on the restoration of Notre Dame, from testing the changing weight of wet limestone, to how to remove lead contamination from four-story stained glass windows. 

As the emergency phase of work winds down, scientists are also starting to use the lull in tourist activity to investigate the mysteries of the cathedral’s construction.

Also this week, Felipe Quiroz, an assistant professor in the biomedical engineering department at the Georgia Institute of Technology and Emory University, talks with Sarah about his paper on the cellular mechanism of liquid-liquid phase separation in the formation of the tough outer layer of the skin. Liquid-liquid phase separation is when two liquids “demix,” or separate, like oil and water. In cells, this process created membraneless organelles that are just now starting to be understood. In this work, Quiroz and colleagues create a sensor for phase separation in the cell that works in living tissue, and show how phase separation is tied to the formation of the outer layers of skin in mice.