This graphic shows the atomically precise assembly of an atomic-scale antiferromagnet with the tip of a scanning tunneling microscope. Iron atoms are placed onto a copper nitride surface and bound by two nitrogen atoms (blue rods) into a regular array separated by one copper atom (yellow). Credit: Sebastian Loth/CFEL
This is a cross section of a mouse liver lobule under a fluorescence microscope. The middle layer reveals an abundance of messenger RNA molecules (white dots) for the gene encoding hepcidin, the iron-regulating hormone.
On probably the most exciting day of David Keays life, his research team found microscopic iron balls in the thinly sliced neurons of a pigeons inner ear. For four years, Keays team had been searching for the cellular receptor that allows birds to sense magnetic fields. This ability allows some birds to migrate thousands of miles, but no scientist has definitively found the anatomical structure responsible.