Is it possible that the value of circadian amplitude higher than circadian MESOR? or depends upon the variable such as physiological (blood pressure) or biochemical (ex. melatonin)?
Hi, Babita
Yes, it is quite a usual thing. The amplitude of a rhythm can be a higher value then mesor. The mesor is usually an estimate of statics of a wave and derived from the average of all variable samples, whereas amplitude is specific to a acrophase of the curve. I would suggest reading this paper would give better insight.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3663600/pdf/nihms249029.pdf
if amplitude is defined as the difference between min and max (like some biologists do), than amplitude can easily be higher than mesor (=average). If amplitude is the difference between max and mesor (or min and mesor), than it can only be higher than mesor if negative values are allowed/present. If negative values are not present, and amplitude is defined as difference between mesor and max, than still amplitude can be higher than mesor if a sine fit is used whit data that do not follow a sine wave. This can happen for instance if sine fits are used to describe some hormonal profiles such as melatonin, which goes to zero at daytime.
Thank you Devraj and Roelof for your answers. Your answers are informative and helped me to clear my doubts.
The mesor is an average, so the amplitute canbe higher that the mesor.