Nonnative Bromus tectorum (cheatgrass) is decimating sagebrush steppe, one of the largest ecosystems in the Western United States, and is causing regional-scale shifts in the predominant plant-fungal interactions. Sagebrush, a native perennial, hosts arbuscular mycorrhizal fungi (AMF), whereas cheatgrass, a winter annual, is a relatively poor host of AMF. This shift is likely intertwined with d...

1. Arid ecosystems are a patch mosaic of plants and biological soil crusts that have been described as islands and mantles of fertility, respectively. To determine whether these patches are metabolically linked by a fungal network of dark septate and arbuscular mycorrhizal fungi (AMF), we measured translocation of nitrogen (N) and carbon (C) in a desert grassland using 15 N-NO 3 and 13 C 5 , 15...

We examined the phylogenetic relationships of two species that mimic Chaetosphaeria in teleomorph and anamorph morphologies, Chaetosphaeriatulasneorum with a Cylindrotrichum anamorph and Australiasca queenslandica with a Dischloridium anamorph. Four data sets were analysed: a) the internal transcribed spacer region including ITS1, 5.8S rDNA and ITS2 (ITS), b) nc28S (ncLSU) rDNA, c) nc18S (ncSSU...

We introduce a model for the computation of a multicommodity flow together with back-up flows for each commodity after any of a given set of failure states occurs in a network. We call such a total routing strategy a restorable multicommodity flow. One advantage of restorable flows over classical network protection methods, such as disjoint paths, is that the commodities may effectively share c...

MicroRNAs (miRNAs) are small, non-coding RNAs that play important roles in post-transcriptional regulation of their target genes, yet the transcriptional regulation of plant miRNAs by promoter is poorly understood. Here, we firstly clone pri-miR475b cDNA and its native promoter from P. suaveolens, and characterize Psu-MIR475b as class-II gene transcribed by RNA polymerase II. By 5' deletion ana...

Take a finite set T of trees, and close it under the operation of substitution—replacing daughterless nonterminals by other trees in T whose root node label matches the nonterminal. The set of all terminal strings of trees in the resultant tree-set will be a context-free language (CFL), and for every CFL there will be such a finite set of trees that generates it under substitution. For an elega...