Figures 5 and 7 suggest that this might result from a slight lack of temporal variability in CHAOS-6 in the southern African region, where secular variation and its gradients are strong in global comparison.
The lack of temporal variability in panel D suggests that groups 1 and 2 together capture the essential secular charge variation shown by the whole HA molecule.
Any temporal variability in exposure would be influenced by behavioral changes (in the use of, or exposure to, products) and by secular changes in the composition or selection of products available on the market, which could affect the reliable estimation of individuals' absolute or relative exposures.
We assessed the secular trends and variability in the number of diagnoses per encounter regardless of immunization status referred as diagnostic code density, by healthcare setting, age, and pre-specified condition in eight large health care systems of the Vaccine Safety Datalink project during 2001 2009.
The highest quality records of geomagnetic secular variation and its time variability come from ground magnetic observatories, where absolute calibrations are routinely carried out.
LUR models explained significant variability as a function of secular trends, traffic density within 500 m, distance from major roads, and block group population density (R = 0.83; Table 3).
In humans, on the one hand, the sex ratio at birth is essentially constant at the secular population level [ 20], but on the other hand, considerable variability of the sex ratio may be observed under a variety of specific circumstances.
By supposing that the observed δ13C modern increase of ∼0.3‰ is also produced by a solar irradiance variability on a longer time scale, through the same mechanisms, we estimate a secular increase of the total solar irradiance between 1760 and 1950 of (0.3/0.08)∗0.1% ≅ 0.37%.
However, for most existing population cohorts, additional variability is introduced by different numbers of visits for individuals and by possible secular drift.
