Hasil untuk "physics.comp-ph"

Dharm Veer Singh, Naveen K. Singh

Minh Tho Nguyen, Tae-Kyu Ha

M. Esseffar, A. Luna, O. Mó et al.

Ph. Chomaz, F. Gulminelli

Ph. Spindel

Philip E. Bickler

J. Golowasch, J.W. Deitmer

J.P. Lemaistre, Ph. Pée, M. Beguery et al.

C. Bréchignac, Ph. Cahuzac, B. Concina et al.

PH Canter

Sahin Buyukdagli, T. Ala-Nissila

We develop an analytical theory that accounts for the image and surface charge interactions between a charged dielectric membrane and a DNA molecule translocating through the membrane. Translocation events through neutral carbon-based membranes are driven by a competition between the repulsive DNA-image-charge interactions and the attractive coupling between the DNA segments on the trans and the cis sides of the membrane. The latter effect is induced by the reduction of the coupling by the dielectric membrane. In strong salt solutions where the repulsive image-charge effects dominate the attractive trans-cis coupling, the DNA molecule encounters a translocation barrier of ≈10 kBT. In dilute electrolytes, the trans-cis coupling takes over image-charge forces and the membrane becomes a metastable attraction point that can trap translocating polymers over long time intervals. This mechanism can be used in translocation experiments in order to control DNA motion by tuning the salt concentration of the solution.

Ph. Catillon

Robert-Ph. Dollfus

Ph. L. Toint

The problem of symmetric sparse updating is considered from a variational point of view and a new class of sparse symmetric quasi-Newton updating formulae is derived. This class results from the use of a nondiagonally weighted Frobenius norm. The computation of the update involves only one positive definite and symmetric linear system that has the same sparsity pattern as the problem itself.

Robert-Ph. Dollfus

Robert Ph. Dollfus

Robert-Ph. Dollfus

Richard P. McCall

Students in physics sections dominated by one academic major prefer examples that are relevant to their course of study. Topics for pharmacy majors (and other health sciences) include references to the human body. An example illustrating fluid dynamics is presented.

Robert-Ph. Dollfus, Jacques Callot, Camille Desportes

Brian Fluegel