In striking contrast to simple polymer physics theory, which does not account for solvent effects, we find that physical confinement of solvated biopolymers decreases solvent entropy, which in turn leads to a reduction in the organized structural content of the polymer. Since our theory is based on a fundamental property of water-protein statistical mechanics, we expect it to have broad implica...

The successful fabrication and experimental verification of a novel metamaterial based on flexible metallic helices is reported. The helices undergo compression under the influence of incident radiation, demonstrating a nonlinear chiral electromagnetic response, associated with the power-dependent change in the helix pitch. This design is promising for application to power-dependent polarizatio...

Building on the work of Nogin [17], we prove that the braid group B4 acts transitively on full exceptional collections of vector bundles on Fano threefolds with b2 = 1 and b3 = 0. Equivalently, this group acts transitively on the set of simple helices (considered up to a shift in the derived category) on such a Fano threefold. We also prove that on threefolds with b2 = 1 and very ample anticano...

An analysis on the nature of alpha-helix stop signals has been carried out, using a dataset of 1057 helices identified from 250 high resolution (</=2.0 A), non-homologous, protein crystal structures. The backbone dihedral angles (phi, psi) of the terminating residue (T) were found to cluster either in the left-handed helical region (alphaL: phi=20 degrees to 125 degrees and psi=-45 degrees to 9...

A k-degenerate graph is a graph in which every induced subgraph has a vertex with degree at most k. The class of k-degenerate graphs is interesting from a theoretical point of view and it plays an interesting role in the theory of fixed parameter tractability since some otherwise W[2]-hard domination problems become fixed-parameter tractable for k-degenerate graphs. It is a well-known fact that...

We discuss the deletion of a single vertex in a Delaunay tetrahedralization (DT). While some theoretical solutions exist for this problem, the many degeneracies in three dimensions make them impossible to be implemented without the use of extra mechanisms. In this paper, we present an algorithm that uses a sequence of bistellar flips to delete a vertex in a DT, and we present two different mech...