cylinder plot

Collapsing bacterial cylinders

Dec. 31, 2001

Under special conditions bacteria excrete an attractant and aggregate. The high density regions initially collapse into cylindrical structures, which subsequently destabilize and break up into spherical aggregates.

dirt cartoon

Formation of structure in snowfields motivated by penitentes, suncups, and dirt cones

Nov. 30, 2001

Penitentes and suncups are structures formed as snow melts, typically high in the mountains. When the snow is dirty, dirt cones and other structures can form instead.