Ronald Adrian is currently a Professor of Mechanical and Aerospace Engineering at Arizona State University. Dr Adrian's research interests are the space-time structure of turbulent fluid motion and the development of techniques, both experimental and mathematical, to explore this structure. Techniques to which he has made fundamental contributions include laser Doppler velocimetry, particle image velocimetry, and the optimal estimation method for analysis of turbulent flows. Dr Adrian is a member of the United States National Academy of Engineering and a Fellow of the American Physical Society, the American Institute of Aeronautics and Astronautics, the American Society of Mechanical Engineers, and the American Academy of Mechanics. Dr Adrian's awards include the 2001 Nusselt-Reynolds Prize for experimental fluid mechanics research, the 2002 AIAA Aerospace Measurement Technology Award for his role in developing the particle image velocimeter, the 2005 Fluid Dynamics Prize from the American Physical Society, and the 2007 Fluid Dynamics Award given by the American Institute of Aeronautics and Astronautics. Jerry Westerweel is the Fluid Dynamics Chair in the Laboratory for Aero and Hydrodynamics at the Delft University of Technology in the Netherlands. His research interests are turbulence and coherent flow structures, turbulent mixing and chemical reactions, disperse multiphase flows, microfluidics and biological flows, optical measurement techniques for quantitative measurements in flows such as particle image velocimetry, planar laser-induced fluorescence, and holography.