It is a standard exercise in mechanical engineering to infer the external forces and torques on a body from a given static shape and known elastic properties. Here we apply this kind of analysis to distorted double-helical DNA in complexes with proteins: We extract the local mean forces and torques acting on each base pair of bound DNA from high-resolution complex structures. Our analysis relie...

We show that algebraically shifting a pair of simplicial complexes weakly increases their relative homology Betti numbers in every dimension. More precisely, let ∆(K) denote the algebraically shifted complex of simplicial complex K, and let β j (K, L) = dim k H j (K, L; k) be the dimension of the jth reduced relative homology group over a field k of a pair of simplicial complexes L ⊆ K. Then β ...

When cells or DNA is exposed to ionizing radiation, the radicals produced in the irradiated sample will modify the base-pair region of the double strands. Effects of 1,2-dihydroxy-9,10-anthraquinone (DHA) and its Cu(II) complex on the radiation-induced modification of double-strands in calf thymus DNA were studied using ethidium bromide as a fluorescent probe. Our results show that the Cu(II)-D...

A vertex coloring of a simplicial complex ∆ is called a linear coloring if it satisfies the property that for every pair of facets (F1, F2) of ∆, there exists no pair of vertices (v1, v2) with the same color such that v1 ∈ F1\F2 and v2 ∈ F2\F1. We show that every simplicial complex ∆ which is linearly colored with k colors includes a subcomplex ∆ with k vertices such that ∆ is a strong deformat...