In common parlance, succulents are all fleshy plants with swollen stems and leaves. Instead, it would be more correct to use the term succulent, as their characteristic feature is that they have succulent tissue inside them, i.e. a soft, spongy fleshiness saturated water produces typical swelling in plant. Usually, of plant aerial parts, stem There are, however, some cases succulence at roots i...

The spectrum of a graph is the family of eigenvalues of its (0, 1) adjacency matrix.A simple graph is reflexive if its second largest eigenvalue 2 does not exceed 2. The graphic property 2 2 is a hereditary one, i.e. every induced subgraph of a reflexive graph preserves this property and that is why reflexive graphs are usually represented through maximal graphs. Cacti, or treelike graphs, are ...

Divergent selection between environments can result in changes to the behavior of an organism. In many insects, volatile compounds are a primary means by which host plants are recognized and shifts in plant availability can result in changes to host preference. Both the plant substrate and microorganisms can influence this behavior, and host plant choice can have an impact on the performance of...

In a taxonomic review of the species of the Heterodera "cacti group," H. thornei n. sp. is described and illustrated from Miner's lettuce in California. This new species is distinguishable especially by havpunctate egg shells and a larval stylet (27 mum) and tail (56 mum) longer than other related species. Heterodera weissi is redescribed, type specimens are designated, and new data added on th...

We consider the following NP-hard problem: in a weighted graph, find a minimum cost set of vertices whose removal leaves a graph in which no two cycles share an edge. We obtain a constant-factor approximation algorithm, based on the primaldual method. Moreover, we show that the integrality gap of the natural LP relaxation of the problem is Θ(logn), where n denotes the number of vertices in the ...

Dozens of arthropod species are known to feed and breed in the necrotic tissues (rots) of columnar cacti in the Sonoran Desert. Because the necrotic patches are ephemeral, the associated arthropods must continually disperse to new cacti and therefore the populations of any given species are expected to show very little local genetic differentiation. While this has been found to be true for the ...

The first detections of Asian citrus psyllid, Diaphorina citri Kuwayama, in North America occurred almost simultaneously in Florida and in the Caribbean (Guadeloupe). Damaging populations on citrus have been reported in Florida but not in Puerto Rico where the psyllid was first detected in 2001, having probably arrived with its parasitoid, Tamarixia radiata Waterston. In an effort to identify a...