objective: animal studies show that vaccination with epitope-based peptides results in protective immunity. however, immunodominance should be regarded as a major challenge in this area. considering the advantages of epitopic-vaccines against hepatitis c virus (hcv) infection, herein, we compared the occurrence of immunodominance following mice immunization with three different hcv epitopic-pep...

The Birkhoff polytope Bn is the convex hull of all n× n permutation matrices in Rn×n. We compute the combinatorial symmetry group of the Birkhoff polytope. A representation polytope is the convex hull of some finite matrix group G 6 GL(d,R). We show that the group of permutation matrices is essentially the only finite matrix group which yields a representation polytope with the face lattice of ...

This paper describes the polytope Pk;N of i-star counts, for all i 6 k, for graphs on N nodes. The vertices correspond to graphs that are regular or as regular as possible. For even N the polytope is a cyclic polytope, and for odd N the polytope is well-approximated by a cyclic polytope. As N goes to infinity, Pk;N approaches the convex hull of the moment curve. The affine symmetry group of Pk;...

A polytope is called a Coxeter polytope if its dihedral angles are integer parts of π. In this paper we prove that if a noncompact Coxeter polytope of finite volume in IH has exactly n+3 facets then n ≤ 16. We also find an example in IH and show that it is unique. 1. Consider a convex polytope P in n-dimensional hyperbolic space IH. A polytope is called a Coxeter polytope if its dihedral angles...

We study the facial structure of two important permutation polytopes in R n 2 , the Birkho or assignment polytope B n , de ned as the convex hull of all n n permutation matrices, and the asymmetric traveling salesman polytope T n , de ned as the convex hull of those n n permutation matrices corresponding to n-cycles. Using an isomorphism between the face lattice of B n and the lattice of elemen...

For n 2, the boolean quadric polytope P n is the convex hull in d := ? n+1 2 dimensions of the binary solutions of x i x j = y ij , for all i < j in N := f1; 2; :::; ng. The polytope is naturally modeled by a somewhat larger polytope; namely, Q n the solution set of y ij x i , y ij x j , x i + x j 1 + y ij , y ij 0, for all i; j in N. In a rst step toward seeing how well Q n approximates P n , ...

The cyclic polytope C(n, d) is the convex hull of any n points on the moment curve {(t, t2, . . . , td ) : t ∈ R} in Rd . For d ′ > d , we consider the fiber polytope (in the sense of Billera and Sturmfels [6]) associated to the natural projection of cyclic polytopes π : C(n, d ) → C(n, d) which ‘forgets’ the last d ′ − d coordinates. It is known that this fiber polytope has face lattice indexe...

We prove that any finite, abstract n-polytope is covered by a finite, abstract regular n-polytope.