A classic problem in computational origami is flat foldability : given a crease pattern (planar straightline graph with n edges) on a polygonal piece of paper P , can P be folded flat isometrically without selfintersection while creasing at all creases (edges) in the crease pattern? The problem can also be defined for assigned crease patterns, in which every crease is labeled mountain or valley...

Abstract Seshadri constants on abelian surfaces are fully understood in the case of Picard number one. Little is known so far for simple higher number. In this paper we investigate principally polarized with real multiplication. They two and might be considered next natural to studied. The challenge not only determine individual line bundles, but understand whole function these surfaces. Our re...

Let S be a topological semigroup acting on a topological space X. We develop the theory of (weakly) almost periodic functions on X, with respect to S, and form the (weakly) almost periodic compactifications of X and S, with respect to each other. We then consider the notion of an action of Son a Banach space, and on its dual, and after defining S-invariant means for such a space, we give a...

All rings are commutative with identity and all modules are unital. Let R be a ring, M an R-module and R(M), the idealization of M . Homogenous ideals of R(M) have the form I (+)N , where I is an ideal of R and N a submodule of M such that IM ⊆ N . A ring R (M) is called a homogeneous ring if every ideal of R (M) is homogeneous. In this paper we continue our recent work on the idealization of m...

We consider the steady free surface two-dimensional flow past a semi-infinite flat plate in water of a constant finite depth. The fluid is assumed to be inviscid, incompressible and the flow is irrotational; surface tension at the free surface is neglected. Our concern is with the periodic waves generated downstream of the plate edge. These can be characterized by a depth-based Froude number, F...

BACKGROUND HIV-1 can infect and replicate in both CD4 T cells and macrophages. In these cell types, HIV-1 entry is mediated by the binding of envelope glycoproteins (gp120 and gp41, Env) to the receptor CD4 and a coreceptor, principally CCR5 or CXCR4, depending on the viral strain (R5 or X4, respectively). Uninfected CD4 T cells undergo X4 Env-mediated autophagy, leading to their apoptosis, a m...