this research was carried out for evaluation of competitive ability of some wheat cultivars (triticum aestivum l.) of recommended wheat in dargaz region with common weed of feral rye (secale cereale). experiment was conducted as factorial based on randomized complete block design with three replications in 2010-2011 growing season. experimental factors were included four wheat cultivars of says...

to evaluate the role of effective factors on competition of two wheat cultivars against two species of narrow leaf and broad leaf weeds this study was conducted as two separated experiments based on a randomized complete block design with 3 replications at agricultural faculty of bu-ali sina university, in 2008-2009. in both experiments, alvand and sayson cultivars were planted with densities o...

In dynamical systems examples are common in which two or more attractors coexist and in such cases the basin boundary is non-empty. The purpose of this paper is to describe the structure and properties of basins and their boundaries for two-dimensional diffeomorphisms. If a two-dimensional basin has a basin cell (a trapping region whose boundary consists of pieces of the stable and unstable man...

The hydrothermal sediments of Guaymas Basin, an active spreading center in the Gulf of California (Mexico), are rich in porewater methane, short-chain alkanes, sulfate and sulfide, and provide a model system to explore habitat preferences of microorganisms, including sulfate-dependent, methane- and short chain alkane-oxidizing microbial communities. In this study, hot sediments (above 60°C) cov...

Recent concern about survival and recovery of highelevation white pine ecosystems has returned white pine blister rust (caused by Cronartium ribicola) to prominence as a significant threat to forest health in the western U.S. (Samman et al., 2003). This, in turn, has spurred new research into potential rustresistance mechanisms in high-elevation white pines, including whitebark (Pinus albicauli...

Unconventional shale-gas plays are formed by fine-grained organic-rich shales of tight-porosity and ultralow permeability which act as the source, seal, and the reservoir rock. The shale-as-reservoir has its beginnings in 1820 but commercial shale-gas wells were drilled in 1990s in Mississippian Barnett Shale of USA by Mitchell Energy after prolonged (about 17 years) experimentations and advanc...

Hydrothermal vent communities are distributed along mid-ocean spreading ridges as isolated patches. While distance is a key factor influencing connectivity among sites, habitat characteristics are also critical. The Pescadero Basin (PB) and Alarcón Rise (AR) vent fields, recently discovered in the southern Gulf of California, are bounded by previously known vent localities (e.g. Guaymas Basin a...

One of the efficient factors in comprehensive development of an area is to provide water sources and on the other hand the appropriate management of them. Population growth and nourishment security for such a population necessitate the achievement of constant development besides the reforming of traditional management in order to increase the profit of sources; In this case, the constant exploi...