Present position: PhD student at Institut de Mécanique d'Alembert (UPMC University Paris 6) Adivsors: Basile Audoly and Sébastien Neukirch
Reasearch interests: My research deals with elasticity in mechanics, physics and biological physics. I mainly focus on the mechanics of elastic structures with a view to understand problems in which physical effects, such as long-range interactions or thermal fluctuations, must be taken into account. Such issues commonly arise in the study of biological processes or experiments like single molecule manipulations. More precisely my PhD research concerns the elastcity of knots and the mechanics of DNA supercoiling.
Abstract: <p style="text-align:justify">We consider an elastic rod model for twisted DNA in the plectonemic regime. The molecule is treated as an impenetrable tube with an effective, adjustable radius. The model is solved analytically, and we derive formulas for the contact pressure, twisting moment, and geometrical parameters of the supercoiled region. We apply our model to magnetic tweezer experiments of a DNA molecule subjected to a tensile force and a torque and extract mechanical and geometrical quantities from the linear part of the experimental response curve. These reconstructed values are derived in a self-contained manner and are found to be consistent with those available in the literature.</p>
Abstract: <p style="text-align:justify">We study the mechanical response of elastic rods bent into open knots, focusing on the case of trefoil and cinquefoil topologies. The limit of a weak applied tensile force is studied both analytically and experimentally: the Kirchhoff equations with self-contact are solved by means of matched asymptotic expansions; predictions on both the geometrical and mechanical properties of the elastic equilibrium are compared to experiments. The extension of the theory to tight knots is discussed.</p>
Abstract: <p style="text-align:justify">The DNA molecule is modeled as an elastic rod with bending and twisting rigidities, subjected to external tension and twist applied at one end, the other end being clamped. We study the plectonemic equilibrium of such a rod, taking into account the impenetrability constraint. Numerical solutions of this boundary value problem have previously shown that purely elastic models can reproduce the supercoiling response of the DNA molecule. Using a variational approach, we derive analytical formulae for the elastic response of the filament, and extend former numerical results.</p>
