and λ̂ := λ̂ ∈Argmin λ∈Λ̂ε ‖λ‖l1 . In the case where f∗ := fλ∗ , λ ∗ ∈ R , Candes and Tao [Ann. Statist. 35 (2007) 2313–2351] suggested using λ̂ as an estimator of λ. They called this estimator “the Dantzig selector”. We study the properties of fλ̂ as an estimator of f∗ for regression models with random design, extending some of the results of Candes and Tao (and providing alternative proofs of thes...

In bryophytes a morphological species concept is still most commonly employed, but delimitation of closely related species based on morphological characters is often difficult. Here we test morphological species circumscriptions in a species complex of the moss genus Racomitrium, the R. canescens complex, based on variable DNA sequence markers from the plastid (rps4-trnT-trnL region) and nuclea...

1. Sib mating avoidance is a pervasive behaviour, which likely evolves in species that sare subject to inbreeding depression. Laboratory studies have provided elegant demonstrations, but small-scale bioassays often minimize the costs associated with mate finding and mate-choice and may for this reason produce spurious findings. 2. We inferred the mating behaviour of the parasitoid wasp Venturia...

the aim of this study was to investigate the fermentation characteristics and cellulolytic enzymes activities of dromedary camels rumen anaerobic fungi in fed with cultivated and pasture forages. hence, the inoculant of rumen anaerobic fungi was prepared by using specific medium and the gas production, digestibility and enzyme activity of rumen fungi were determined on the basis of a 2 × 2 fact...

the toxicity of four potentially toxic trace elements (cu, ni, pb and zn) to annual atriplex (a.hortensis and a. rosea) was examined to determine if this plant showed sufficient tolerance to be used tophytoremediate soils polluted with these heavy metals. the soils, which contained up to (per kilogram) 501mg cu, 1674 mg ni, 1334 mg pb and 3588 mg of zn were sampled around metal-contaminated sit...

abstract nowadays, environmental pollution by heavy metals is one of the most serious threats of the world which needs effective remediation actions. the aim of this study was to investigate the potential use of atriplex [atriplex verucifera], salicornia [salicornia europaea] and chenopodium album in simultaneous uptake and accumulation of na and cd or pb in two calcareous soils with different ...

High temperature can induce the production of 2n gametes and aborted pollen during microsporogenesis in Populus canescens. However, mechanism by which high induces abortion remains unknown. Here, was induced exposing male flower buds P. canescens to 38 41 °C; morphology, meiotic abnormalities, defects microtubular cytoskeleton, tapetum development were characterized. We found that dominant stag...

BACKGROUND AND AIMS In contrast to seeds, high sensitivity of vegetative fragments to unfavourable environments may limit the expansion of clonal invasive plants. However, clonal integration promotes the establishment of propagules in less suitable habitats and may facilitate the expansion of clonal invaders into intact native communities. Here, we examine the influence of clonal integration on...

Feeding agro-industrial by-products and unconventional forages, rich in potentially anti-nutritional factors, may influence the quality of the raw milk and the dairy products prepared therefrom. The aim of the present study was to determine side-effects on physicochemical properties of milk, yoghurt and cheese of feeding diets where one third were feeds either rich in lipids (tomato pomace and ...