Sat, 19 Jul 2008 19:13:26 BST CiteULike: dchens Marques http://www.citeulike.org/user/dchen/author/Marques CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/dchen/article/1175923 <i>Physical Review E (Statistical, Nonlinear, and Soft Matter Physics), Vol. 75, No. 2. (2007)</i><br /><br />The shapes of flat pebbles may be characterized in terms of the statistical distribution of curvatures measured along their contours. We illustrate this method for clay pebbles eroded in a controlled laboratory apparatus, and also for naturally occurring rip-up clasts formed and eroded in the Mont St.-Michel bay. We find that the curvature distribution allows finer discrimination than traditional measures of aspect ratios. Furthermore, it connects to the microscopic action of erosion processes that are typically faster at protruding regions of high curvature. We discuss in detail how the curvature may be reliably deduced from digital photographs. Shape and erosion of pebbles DJ Durian H Bideaud P Duringer AP Schroder CM Marques doi:10.1103/PhysRevE.75.021301 Physical Review E (Statistical, Nonlinear, and Soft Matter Physics), Vol. 75, No. 2. (2007) 2007-03-19T13:52:50-00:00 2007 Physical Review E (Statistical, Nonlinear, and Soft Matter Physics) 75 2 APS 2007 cool durian grains pre qualif2 shape http://www.citeulike.org/user/dchen/article/2767637 <i>Physical Review Letters, Vol. 100, No. 10. (2008)</i><br /><br />We introduce a general methodology based on magnetic colloids to study the recognition kinetics of tethered biomolecules. Access to the full kinetics of the reaction is provided by an explicit measure of the time evolution of the reactant densities. Binding between a single ligand and its complementary receptor is here limited by the colloidal rotational diffusion. It occurs within a binding distance that can be extracted by a reaction-diffusion theory that properly accounts for the rotational Brownian dynamics. Our reaction geometry allows us to probe a large diversity of bioadhesive molecules and tethers, thus providing a quantitative guidance for designing more efficient reactive biomimetic surfaces, as required for diagnostic, therapeutic, and tissue engineering techniques. Measuring the Kinetics of Biomolecular Recognition with Magnetic Colloids Cohen Tannoudji E Bertrand J Baudry C Robic C Goubault M Pellissier A Johner F Thalmann Lee CM Marques J Bibette doi:10.1103/PhysRevLett.100.108301 Physical Review Letters, Vol. 100, No. 10. (2008) 2008-05-07T23:01:32-00:00 2008 Physical Review Letters 100 10 APS 2008 colloids magnetic