abstract in order to determine the time of maximum demand of winter wheat (triticum aestivum l.) to phosphorous fertilizers and p and zinc (zn) distribution in different parts of wheat at various growth stages and study their relation to the contents of these elements in soil p and zn under field conditions, samples were collected from different parts of the plants at seven growth stages (i.e.,...

abstract in this study, willingness to pay of 180 wheat farmers in khorasan razavi province to remove weeds in different options and different growth stages in 2008 through logarithmic regression was investigated. the results indicated that farmer's total annual income, being perennial of weeds and dummy variables percent of removing weeds in growth different stages, had positive and significan...

to achieve the desired level of animal performance providing animal food supplies containing mineral elements is essential. for this purpose, mineral elements of 8 important rangeland species, including ferula ovina, prangus uloptera, medicago sativa, lotus goeblia, trifolium montanum, melilotus officinalis, sanguisorba minor and stachys inflate, were measured at different growth stages in the ...

Research in recent years has supported the hypothesis that many properties of the electroencephalogram (EEG) are specific to an individual. In this study, the intra- and inter-individual variations of sleep EEG signals were investigated. This was carried out by analyzing the stability of the average EEG spectra individually computed for the Rechtschaffen and Kales (RK) sleep stages. Six EEG cha...

A Markov chain model has been proposed as a mechanism that generates human sleep stages. A method for estimating the parameters of the model, i.e., the transition probabilities (rates) between sleep stages, has been introduced and applied to 95 hypnograms taken from 23 subjects. The rates characterize interindividual differences and nightly variations of the sleep mechanism, related to sleep-on...