Canola (Brassica napus) is cultivated for oil as a biofuel crop. Few quantitative data concerning its tolerance to abiotic stresses has been presented. We evaluated the tolerances of canola to drought and salinity stresses in terms of parameter values in a macroscopic root water uptake model. We conducted an experiment using nine columns with two plants in each: three columns were under drought stresses, another three were under saline stress and others provided potential transpiration. Two soil moisture and salinity probes were inserted into each of the six columns under stress to monitor water content and electrical conductivity. Weight of the columns was manually measured to obtain daily transpiration. Water uptake at each depth and time was calculated by substituting linearly interpolated matric and osmotic potentials into the stress response function. Determined stress response functions indicated that canola is more sensitive to drought compared to Jatropha. While, it was found to be as tolerant as Jatropha to salinity stress in terms of transpiration. Matric potential was more determining than osmotic potential to root water uptake of canola.
A systematical exposition of the concept of number cannot be found in Aquinas’ works. Nevertheless, there are many places where the problem is touched. The problem is encountered on the one hand within the discussion of the category of quantity and on the other hand when Aquinas speaks about transcendental concepts and deals with the problem of numerical statements concerning God. The aim of the paper is to reconstruct, on the basis of Aquinas more or less fragmentary ideas, his concept of number., Systematický výklad pojmu čísla nelze nalézt v dílech Akvinů. Existuje však mnoho míst, kde se problém dotýká. Problém se objevuje na jedné straně v rámci diskuse o kategorii kvantity a na druhé straně, když Aquinas hovoří o transcendentálních pojmech a zabývá se problémem číselných tvrzení o Bohu. Cílem příspěvku je rekonstruovat na základě Akvinů více či méně fragmentární myšlenky, jeho koncept čísla., and David Svoboda , Prokop Sousedík