to study the effects of nitrogen on tomato plant growth and the possibility of reducing nitrogen in drainage water, two nutrient solutions (complete nutrient solution (n+) and nutrient solution with a 30% decrease in n concentration (n-)) along with and three culture media (perlite, a mixture of perlite and nh4- enriched zeolite and finally a mixture of perlite and raw zeolite) were employed fo...

In this paper we combine nonstandard finite-difference (NSFD) schemes and Richardson’s extrapolation method to obtain numerical solutions of two biological systems. The first biological system deals with the dynamics of phytoplankton–nutrient interaction under nutrient recycling and the second one deals with the modeling of whooping cough in the human population. Since both models requires posi...

Previous investigations have confirmed the potential effectiveness of various metabolic stimulants and physiological salt solutions in supporting broiler embryogenesis. The current study investigated the effects of the same solutions on chick posthatch performance and tissue nutrient profiles. In the first of 2 trials, 200 μL each of a (i) 0.18 mM carbohydrate electrolyte nutrient (CEN) solutio...

A mathematical model of infiltrative tumour growth taking into account cell proliferation, death and motility is considered. The model is formulated in terms of local cell density and nutrient (oxygen) concentration. In the model the rate of cell death depends on the local nutrient level. Thus heterogeneous nutrient distribution in tissue affects tumour structure and development. The existence ...

CONTENTS 3.1 Temperate Region Soil Differences .................................................................................. 28 3.2 Challenges to Soil Fertility and Management................................................................ 29 3.2.1 Soil Organic Matter Restoration and Conservation.......................................... 30 3.2.2 High Nutrient-Use Efficiency .................

The growth of a species feeding on a limiting nutrient supplied at a constant rate is modelled by chemostat-type equations with a general nutrient uptake function and delayed nutrient recycling. Conditions for boundedness of the solutions and the existence of non-negative equilibria are given for the integrodifferential equations with distributed time lags. When the time lags are neglected cond...