Noise sources also differ when seen in a shorter time perspective (variations over minutes).
In this perspective, variations of ΔLODeff (1850 to 2009 period) and of the corresponding quantity Δω eff =ω n − ω n−1, being the difference of the Earth's rotation rate, over two consequent years are reported in Additional file 1: Figures S11 and S12, respectively.
From that perspective, variations in professional density from the defined standard across a geographical area are considered imbalances.
From a reaction-norm perspective, phenotypic variation in these traits reflects both genetic and plastic effects, along with possible genetic variation in this plasticity.
From an individual user perspective, such variation in the achievable performance indicates low reliability of the transmission quality and is typically inacceptable.
The key elements of evolutionary models are the external environment (patent regimes, market structures, standards and regulations as well as natural environment) in which technologies are developed, the population perspective and variation (not only average values but also variances in the population of firms/products are in focus of analysis).
For perspective, normal variation in IOP over a 24-hour period among healthy subjects is approximately 7 mmHg.
This idea is consistent with the quantitative genetics perspective that variation and covariation of phenotypic traits are subject to the effects of natural selection [ 34, 35].
In the systems improvement perspective, excess variation in health system structures and processes is a cause for concern, indicating possible inefficiencies and opportunities to improve the system [ 5, 6].
From our perspective, the variation is unimportant because each attribute contains an implicit clause of ceteris paribus: all other things being equal, humility is generally now seen to be desirable and its importance can be assessed alongside that of other human attributes.
Finally, the issue raised earlier regarding coordinating the two perspectives on variation and distribution, that is, variation as generating distribution and distribution as variation from a desired 'model' (Prodromou and Pratt, 2006), warrants increased curriculum and research consideration.
