Closing the Water Balance with a Precision Small-Scale Field Lysimeter.

We developed a set of two precision, small-scale, water balance lysimeters to provide accurate measurements of bare soil evaporation. Each lysimeter comprises a soil tank, a balance assembly with load cell, a wicking drainage system, and a stilling well to measure drained water. Fiberglass wicks installed at the bottom of the soil tanks provide -60 cm of tension to the base of the soil column, and soil water drainage is quantified to close the water balance within the lysimeter.

Selective, controllable, and reversible aggregation of polystyrene latex microspheres via DNA hybridization.

The directed three-dimensional self-assembly of microstructures and nanostructures through the selective hybridization of DNA is the focus of great interest toward the fabrication of new materials. Single-stranded DNA is covalently attached to polystyrene latex microspheres. Single-stranded DNA can function as a sequence-selective Velcro by only bonding to another strand of DNA that has a complementary sequence.