Examining changes in population exposure over time in lahar-prone areas provides insight on where new education efforts may be needed.
A J-shaped exposure-risk relationship with a diminishing population exposure over time fitted the observed seasonal pattern in the Danish birth weight data.
A microenvironmental study allows comparison of the exposure levels between different study areas but does not necessarily reflect population exposure because time spent in different microenvironments may differ between study populations.
The D-value was determined from the inactivation kinetic curve given by the equation: t = D × (log No-log Nf) = D × n [ 1], where D = D-value (min) at specified conditions, No = bioburden of the chosen bacterium as the BI; Nf = surviving population after an exposure time, t (min), to the selected disinfectant and n = (log No-log Nf) = log10 reduction of a bioburden.
Unfortunately, ex vivo analyses such as these remain complex and their utility may depend on several factors including the inhibitor's relative specificity for tumour-associated endothelial cells, the sensitivity of the assay to detect effects on rare cell populations, and limited exposure time of the drug to have an effect on peripheral blood cells before they are isolated.
However, the test of whether population exposure patterns vary over time between outcome groups is valid.
In placebo-controlled trials in adult PAH patients, elevations of liver aminotransferases (more than three times the upper limit of normal) occurred in 12.8% of the population (n= 258; median exposure time to bosentan 18.8 months) [ 21], and they appeared to be dose dependent [ 22].
As a result, previous measurement studies have focussed mainly on maximum exposure levels occurring over space and/or time, as appropriate for assessing compliance with safety limits, but not on exposure patterns in the general population such as average personal exposure, time spent above a threshold or rate of change.
The sum of censored person-time identified from the hospital and death registers within each sociodemographic group was removed from the aggregate person-years of follow-up within each sociodemographic group (inferred from the full baseline population counts) to obtain accurate exposure time in each sociodemographic group.
Rates for all three types of cancer are also projected to double by the year 2020 as the UAE population ages, total fertility declines, exposure time to lifestyle risk factors increases, the prevalence of obesity and diabetes increases, and due to the long latency period between starting smoking and developing lung cancer.
Freire et al. (2013) considered the time dependence of population exposure with respect to tsunami threat and developed high-resolution daytime and nighttime population distribution maps.
