Let G(V,E) be a simple graph with m edges. For a given integer k, a k-shifted antimagic labeling is a bijection f:E(G)→{k+1,k+2,…,k+m} such that all vertices have different vertex-sums, where the vertex-sum of a vertex v is the total of the labels assigned to the edges incident to v. A graph G is {\it k-shifted antimagic} if it admits a k-shifted antimagic labeling. For the special case when k=0, a 0-shifted antimagic labeling is known as {\it antimagic labeling}; and G is {\it antimagic} if it admits an antimagic labeling. A spider is a tree with exactly one vertex of degree greater than two. A spider forest is a graph where each component is a spider. In this article, we prove that certain spider forests are k-shifted antimagic for all k≥0. In addition, we show that for a spider forest G with m edges, there exists a positive integer k0

Motivated by applications in molecular biology and genotyping, this paper proposes a novel model of group testing for identifying items with real-valued status using nonbinary pooling designs under standard arithmetic observation. The purpose is to learn more information of each item to be tested rather than identify only which ones are defectives as was done in conventional group testing. This paper provides several efficiently decodable nonadaptive strategies for the considered problem. The major tool is a new structure called q-ary additive (w, d)-disjunct matrix, which is related to known structures: 1) the conventional disjunct matrix by Kautz and Singleton 1964 and 2) the SQ-disjunct matrix by Emad and Milenkovic 2012.