the rehabilitation of sandy desertified land in various dryland ecosystems by different management practices has a great potential to increase aggregate stability and improve soil quality. however, plants in general may have a different ability to sustain soil. the objective was to determine the effects of reclamation practices including haloxylon ammodendron and atriplex canescens plantation o...

Diameter—the task of computing the length of a longest shortest path—is a fundamental graph problem. Assuming the Strong Exponential Time Hypothesis, there is no O(n)time algorithm even in sparse graphs [Roditty and Williams, 2013]. To circumvent this lower bound we aim for algorithms with running time f(k)(n+m) where k is a parameter and f is a function as small as possible. For our choices of...

In this paper the Maximal Diameter Theorem of Riemannian geometry is proven for Riemannian orbifolds. In particular, it is shown that a complete Riemannian orbifold with Ricci curvature bounded below by (n− 1) and diameter = π, must have constant sectional curvature 1, and must be a quotient of the sphere (S, can) of constant sectional curvature 1 by a subgroup of the orthogonal group O(n+1) ac...

The main result of the paper is to prove for every r ≥ 0 and n > n0(r) that every antichain on n vertices and consisting of more than ( n r ) sets contains two members whose symmetric difference is at least 2r + 2. The bound is best possible and all the extremal families are determined. For r ≥ 3 we show that n > 6(r + 1)2 is sufficient.

Abstract Diameter —the task of computing the length a longest shortest path—is fundamental graph problem. Assuming Strong Exponential Time Hypothesis, there is no $$O(n^{1.99})$$ O ( n 1.99 ) -tim...