It has previously been shown that lack of magnesium, potassium or manganese depresses allocation of new mass to roots in trees, and that these elements often occur in low amounts in declining forest stands. A model for tree growth and nutrient uptake was used to examine the effect of allocation pattern of new plant mass on growth and development in soils with low nutrient concentrations. Growth...

Hairy roots are plants genetically transformed by Agrobacterium rhizogenes, which do not produce shoots and are composed mainly by roots. Hairy roots of Ophiorrhiza mungos Linn. are currently gaining interest of pharmacologists, since a secondary product of their metabolism, camptothecin, is used in chemotherapy. To optimize the production of valuable secondary metabolites it is necessary to un...

Inorganic N is available to plants from the soil as ammonium [Formula: see text] and nitrate [Formula: see text]. We studied how wheat grown hydroponically to senescence in controlled environmental chambers is affected by N form ([Formula: see text] vs. [Formula: see text]) and CO(2) concentration ("subambient," "ambient," and "elevated") in terms of biomass, yield, and nutrient accumulation an...

The relative importance of the various pedological, climatological and physiological factors contributing to the short stature of tropical montane cloud forest (TMCF) is not well understood. This study endeavours to elucidate the controls on carbon assimilation and productivity, which, in conjunction with differences in carbon allocation, interact synergistically to reduce canopy height relativ...

We present a simplified two-dimensional model of fluid flow, nutrient transport and cell distribution in a hollow fibre membrane bioreactor, with the aim of exploring how fluid flow can be used to control the distribution and yield of a cell population which is sensitive to both fluid shear stress and nutrient concentration. The cells are seeded in a scaffold in a layer on top of the hollow fib...

Controlling the light energy and major nutrients is important for high cell density culture of cyanobacterial cells. The growth phase of Anabaena variabilis can be divided into an exponential growth phase and a deceleration phase. In this study, the cell growth in the deceleration phase showed a linear growth pattern. Both the period of the exponential growth phase and the average cell growth r...

We study spreading of a nonmotile bacteria colony on a hard agar plate by using agent-based and continuum models. We show that the spreading dynamics depends on the initial nutrient concentration, the motility, and the inherent demographic noise. Population fluctuations are inherent in an agent-based model, whereas for the continuum model we model them by using a stochastic Langevin equation. W...

Dysphagia affects 590 million people worldwide and increases risk for malnutrition. Puréed food may reduce choking, however preparation differences impact nutrient density making quality assurance necessary. This paper is the first study to investigate the feasibility of computational puréed food nutritional density analysis using an imaging system. Motivated by a theoretical optical dilution m...

Norms of reaction for a number of growth and reproductive characters were determined for 15 randomly sampled Polygonum persicaria genotypes, from two natural populations originating in sites with very different nutrient availabilities. Under severely limiting nutrient conditions, these genotypes shared not only plastic responses such as increased root-to-shoot ratio, but a surprising constancy ...