We derive a three-term asymptotic expansion for the expected lifetime of Brownian motion and for the torsional rigidity on thin domains in R, and a two-term expansion for the maximum (and corresponding maximizer) of the expected lifetime. The approach is similar to that which we used previously to study the eigenvalues of the Dirichlet Laplacian and consists of scaling the domain in one directi...

We generalize to the p−Laplacian ∆p a spectral inequality proved by M.-T. Kohler-Jobin. As a particular case of such a generalization, we obtain a sharp lower bound on the first Dirichlet eigenvalue of ∆p of a set in terms of its p−torsional rigidity. The result is valid in every space dimension, for every 1 < p < ∞ and for every open set having finite measure. Moreover, it holds by replacing t...

We have developed a high-throughput approach to the labor-intensive problems of DNA cyclization, which we use to characterize DNA curvature and mechanical properties. The method includes a combinatorial approach to make the DNA constructs needed and automated real-time measurement of the kinetics using fluorescence. We validated the approach and investigated the flexibility of two kinds of nick...

We have investigated internal motion of DNA in bacteriophages by measuring fluorescence anisotropy decays of intercalated ethidium. The results showed large suppression of the internal motion of the inner DNA; the interhelix interaction of the DNA in the phage head is considered to enhance the effective viscosity of the DNA rod and to restrict the angle of the internal motion. Considering that ...

OBJECTIVE Rod-screw fixation systems are widely used for spinal instrumentation. Although many biomechanical studies on rod-screw systems have been carried out, but the effects of rod contouring on the construct strength is still not very well defined in the literature. This work examines the mechanical impact of straight, 20° kyphotic, and 20° lordotic rod contouring on rod-screw fixation syst...

In the present paper we consider spectral optimization problems involving the Schrödinger operator −∆ + μ on R, the prototype being the minimization of the k the eigenvalue λk(μ). Here μ may be a capacitary measure with prescribed torsional rigidity (like in the Kohler-Jobin problem) or a classical nonnegative potential V which satisfies the integral constraint ∫ V −pdx ≤ m with 0 < p < 1. We p...

We introduce a new method to prove the isoperimetric property of the ball for the first eigenvalue of the Robin-Laplacian. Our technique applies to a full range of Faber-Krahn inequalities in a nonlinear setting and for non smooth domains, including the open case of the torsional rigidity. The analysis is based on regularity issues for free discontinuity problems in spaces of functions of bound...

B-DNA becomes unstable under superhelical stress and is able to adopt a wide range of alternative conformations including strand-separated DNA and Z-DNA. Localized sequence-dependent structural transitions are important for the regulation of biological processes such as DNA replication and transcription. To directly probe the effect of sequence on structural transitions driven by torque, we hav...

In this paper, the characterisation of elastic shear buckling behaviour simply supported plates diagonally stiffened excluding influence direct stresses is made. Two broad numerical parametric studies consisting linear analysis by finite element method are performed, covering entire practical range critical parameters like aspect ratio and stiffener’s mechanical properties. first study, attenti...