Let G be a planar graph with n vertices whose vertex set is partitioned into subsets V0, . . . , Vk−1 for a positive integer 1 ≤ k ≤ n and let S be a set of n distinct points in the plane partitioned into subsets S0, . . . , Sk−1 with |Vi| = |Si| (0 ≤ i ≤ k − 1). This paper studies the problem of computing a crossing-free drawing of G such that each vertex of Vi is mapped to a distinct point of...

The homomorphisms of oriented or undirected graphs, the oriented chromatic number, the relationship between acyclic coloring number and oriented chromatic number, have been recently studied. Improving and combining earlier techniques of N. Alon and T. H. Marshall (1998, J. Algebraic Combin. 8, 5 13) and A. Raspaud and E. Sopena (1994, Inform. Process. Lett. 51, 171 174) we prove here a general ...

The aim of this study is to assess the effect polyphenol curcumin on lipid peroxidation (LPO) in homogenate cerebral hemispheres from rats exposed round-the-clock lighting (RCL) and kept high-calorie carbohydrate-lipid diet (HCCLD). experiments were performed 21 white male Wistar weighing 210-250 g, divided into 3 groups 7 animals each. Animals group 1 (control I) a standard vivarium equal alte...

We study k-colored kernels in m-colored digraphs. An m-colored digraph D has k-colored kernel if there exists a subset K of its vertices such that (i) from every vertex v / ∈ K there exists an at most k-colored directed path from v to a vertex of K and (ii) for every u, v ∈ K there does not exist an at most k-colored directed path between them. In this paper, we prove that for every integer k ≥...

Safari parks, roadside menageries, exotic animal auctions and wildlife rehabilitation centres exist world-wide, and serve as sites of wild animal concentrations. When these animals are brought together, the potential is great for the spread and eventual outbreak of many different infectious and parasitic diseases. It is therefore necessary that procedures be developed in these facilities to min...