diurnal variation


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Related to diurnal variation: diurnal variation of temperature

diurnal variation

1 the variability of output or excretion of a substance during the day versus the night or over a 12-hour interval.
2 expected high and low levels of a substance during a 24-hour period. For example, blood cortisol is highest in the morning and lowest in the early evening.
References in periodicals archive ?
Diurnal variations in summer season precipitation in India.
Motor performance, requiring coordination and reactive strength, may have different diurnal variation due to a hierarchy of biological clocks, which are commanded by the "master" clock in the CNS, acting in synchrony with the environment and activity (Waterhouse, 2010; Richter et al.
The present findings reveal significant diurnal variations within the SCI subjects for Mb and H-FABP, with morning values generally elevated compared with those collected later in the day, a trend previously reported with nondisabled subjects [22-23].
To analyze diurnal variation of 12 hour (6:00 am to 6:00 pm) of day time and 12 hours (6:00 pm to 6:00 am) of night time were compared.
The diurnal variation in these parameters does not seem to be determined by an endogenous circadian rhythm, but rather through changes in physical activity over the 24-hour period.
Determine if the stress of an exam would cause students to lose their normal diurnal variation of cortisol.
Analysis of diurnal variation of lymphocyte subsets in healthy subjects in the Caribbean, and its implication in HIV monitoring and treatment.
4 individuals; min = 2, max = 11) between 1700 and 1800 hrs without any significant diurnal variation (Fig.
Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) is another tool which uses nonverbal assessments to evaluate acute or fluctuating onset of delirium, inattention, disorganized thinking and altered level of consciousness, however, sleep-wake cycle, diurnal variation and lability of mood are not questioned by CAM-ICU, while they are well evaluated by NDRS.
During the period from 2005 to 2007 it is observed that the diurnal variation of total column ozone is increasing from February to May after that it shows a decreasing trend up to the month of December.
In this volume we also show that bio-optical model calculations could provide an alternative to the time-consuming 14C method in order to estimate the diurnal variation of primary production.