in this study, species richness, evenness and vegetation biodiversity were investigated in stabilized and non-stabilized cut edge areas of chachkam district forest roads in sari forest of iran. 18 micro plots 1×1m (36 micro plots) were sampled to carry out this research on two cut edge areas. number of trees, shrubs and herbaceous were recorded in each micro-plot. significant difference was inv...

By reconciling the phylogenetic tree of a gene family with the corresponding species tree, it is possible to infer lineage-specific duplications and losses with high confidence and hence to annotate orthologs and paralogs. The currently available reconciliation methods for non-binary gene trees are computationally expensive for genome-scale applications. We present four O(|G| + |S|) algorithms ...

It is known that the set of all redexes for a left-linear term rewriting system is recognizable by a tree automaton, which means that we can construct a tree automaton that accepts redexes. The present paper extends this result to Nipkow’s higher-order rewrite systems, in which every left-hand side is a linear fully-extended pattern. A naive extension of the first-order method causes the automa...

capacity of garden productions in iran is such that is accounted as a country that produces thirteen garden products in the world but despite excellent condition in iran for producing garden products, natural disasters damage production of fruits in the country therefore farmers incur a loss. pistachio tree has been in danger of destruction and dryness. thus, in order to reduce loss incurred on...

We show that for every rooted, finitely branching, pruned tree T of height ω there exists a family F which consists of order isomorphic to T subtrees of the dyadic tree C = {0, 1}<N with the following properties: (i) the family F is a Gδ subset of 2C ; (ii) every perfect subtree of C contains a member of F ; (iii) if K is an analytic subset of F , then for every perfect subtree S of C there exi...

Given a graph G and a subset W ⊆ V (G), a Steiner W -tree is a tree of minimum order that contains all of W . Let S(W ) denote the set of all vertices in G that lie on some Steiner W -tree; we call S(W ) the Steiner interval of W . If S(W ) = V (G), then we call W a Steiner set of G. The minimum order of a Steiner set of G is called the Steiner number of G. Given two vertices u, v in G, a short...

A hierarchical divisive algorithm is proposed for identifying communities in complex networks. To that effect, the definition of community in the weak sense of Radicchi [Proc. Natl. Acad. Sci. U.S.A. 101, 2658 (2004)] is extended into a criterion for a bipartition to be optimal: one seeks to maximize the minimum for both classes of the bipartition of the ratio of inner edges to cut edges. A mat...

A metric d is h-embeddable if it can be isometrically embedded in some hypercube. Equivalently, d is h-embeddable if d can be written as a nonnegative integer combination of cut metrics. The problem of testing h-embeddability is NP-complete (Chvbta!, 1980). A good characterization of h-embeddability permitting a polynomial-time algorithm was given for several classes of metrics, in particular, ...

For positive integers k,n, we investigate the simplicial complex NMk(n) of all graphs G on vertex set [n] such that every matching in G has size less than k. This complex (along with other associated cell complexes) is found to be homotopy equivalent to a wedge of spheres. The number and dimension of the spheres in the wedge are determined, and (partially conjectural) links to other combinatori...