Biodiversity plays a crucial role in stability and productivity of natural ecosystem. The main goal of this research was to classify ecological groups in steppe rangeland and investigate their relationships with plant diversity indices. Therefore, fifty different Land Unit Tracts (LUT) were identified in Khod-Neuk basin, Yazd province, Iran, in 2010. Vegetation and soil samples were taken in th...

the predatory mites of suborder prostigmata are important natural enemies of spider mites. in this study abundance and biodiversity of predatory mites of super families of raphignathoidea, bdelloidea and erythraeoidea in pomefruit orchards of mashhad) educational orchard of agricultural college of ferdowsi unuversity of mashhad, agricultural research centre of torogh and laeen, torghabe and sha...

There exist many topological indices that are calculated on saturated hydrocarbons since they can be easily modelled by simple graphs. On the other hand, it is more challenging to investigate for with multiple bonds. The purpose of this paper introduce a model gives good results predicting physico-chemical properties alkenes and alkadienes. In particular, we interested in boiling points these m...

Let G and H be two graphs. The corona product G o H is obtained by taking one copy of G and |V(G)| copies of H; and by joining each vertex of the i-th copy of H to the i-th vertex of G, i = 1, 2, …, |V(G)|. In this paper, we compute PI and hyper–Wiener indices of the corona product of graphs.

A factorization theory is proposed for Wiener-Hopf plus Hankel operators with almost periodic Fourier symbols. We introduce a factorization concept for the almost periodic Fourier symbols such that the properties of the factors will allow corresponding operator factorizations. Conditions for left, right, or both-sided invertibility of the Wiener-Hopf plus Hankel operators are therefore obtained...

Let G be a graph with vertex set V(G) and edge set E(G). For any two vertices x and y in V(G), the distance between x and y, denoted by d(x,y), is the length of the shortest path connecting x and y. The degree of a vertex v in G is the number of neighbors of v in G. Numbers reflecting certain structural features of organic molecules that are obtained from the molecular graph are usually called ...

Abstract: The Hosoya polynomial of a molecular graph G is defined as ∑ ⊆ = ) ( } , { ) , ( ) , ( G V v u v u d G H λ λ , where d(u,v) is the distance between vertices u and v. The first derivative of H(G,λ) at λ = 1 is equal to the Wiener index of G, defined as ∑ ⊆ = ) ( } , { ) , ( ) ( G V v u v u d G W . The second derivative of ) , ( 2 1 λ λ G H at λ = 1 is equal to the hyper-Wiener index, d...

"cortical mosaic" theory of the localization of movements by the unit representation of individual muscles, and stresses the importance, alike to physiologists and clinicians, of a wvider appreciation of the importance of the hypothesis of multiple and overlapping representations of movements rather than muscles. In this admirable essay the author shows himself to share with Hughlings Jackson, ...