The aim of this study was to analyze the effect of drought stress on the kinetics of leaf elongation in relationship to the variation of sugar concentrations and their net deposition rates along the elongation zone of leaf 4 of durum wheat plants. Plants were grown in soil in a naturally illuminated greenhouse, and water...

this study investigated the variation between two sugar beet (beta vulgaris l.) cultivars with respect to growth parameters and photosynthetic rates of individual attached leaves during salinization. sugar beet plants grown in sand culture were gradually exposed to different levels of salinity (0, 50, 150 , 250, and 350 mm, nacl+cacl2 in 5:1 ratio). salt concentrations significantly decreased a...

Maize (Zea mays L.) stem is thought to function alternately as a net importing and net exporting organ during ontogeny, depending on whole plant photosynthetic source and sink status. The [(14)C]sucrose and [(14)C]glucose uptake capacity of stem tissues was investigated to increase our understanding of the transport factors which may influence sink status.Uptake from solutions containing up to ...

Tall fescue leaf blades elongate at near constant rates during most of the light and dark periods of the diurnal cycle, with the dark rate being higher by 60 to 65%. Our objective was to determine relationships among diurnal rates of leaf elongation, deposition of water and deposition of dry matter (DM) into the elongation zone. Two separate experiments were conducted, both with a 15-hour photo...

The suitability of three vapor deposition techniques for pore size modification was evaluated using polycarbonate track etched membranes as model supports. A feature scale model was employed to predict the pore geometry after modification and the resulting pure water flux. Physical vapor deposition (PVD) and pulsed plasma-enhanced chemical vapor deposition (PECVD), naturally, form asymmetric na...

Mercury emissions from chlor-alkali plants have been past and present sources of soil contamination with Hg. Here we calculate net mercury (Hg) deposition to soils in the vicinity (100-1000-m downwind) of three-chlor alkali plants. Calculations were based on spatial distribution patterns of Hg concentrations in soils, which were extrapolated by kriging. Moreover, we investigated to what extent ...

In a northwestern Connecticut forest, we quantified the carbon (C) and nitrogen (N) content of the forest floor and the top 15 cm of mineral soil and the rate of midsummer net N mineralization beneath six different tree species. There were large interspecific differences in forest floor depth and mass, in the size and distribution of C and N pools at varying soil depths, and in rates of midsumm...

Along with the scaled-up distribution of long-lasting insecticidal nets for malaria control has become concern about insecticide resistance. A related concern regards the evolution of host-seeking periodicity from the nocturnal to the crepuscular periods of the day. Why we observe such shifts in some areas but not others and which methods could prove useful in managing such behavioral resistanc...

3-O-Methyl-D-glucose transport across the plasma membrane of isolated rat hepatocytes was followed for net entry of the sugar into sugar-free cells (zero trans entry), net exit of sugar into sugar-free medium (zero trans exit) and for unidirectional entry and exit fluxes when cells had been equilibrated with sugar in the extracellular medium (equilibrium exchange entry and exit). These measurem...