This estimator has an intuitive appeal because it can be viewed as a Kaplan-Meier estimator computed on k components, one for each stratum, in which all the mj controls are given the same weight.
In the final model, the prognostic factors that showed statistically significant effects were analyzed according to subgroups to determine the effect of each stratum on survival time for breast cancer patients.
Estimates were corrected for the complex sampling design of the study in order to obtain a stratified probabilistic sample whose primary selection unit was village and the weights of each participant were based on the relative size of each stratum and the proportion of women and children in the target population.
We calculated λO and λP, conditional on γ=1.8, for each stratum using an iterative numerical algorithm written specifically for the task in Stata version 8.2 (Stata Corporation, College Station, TX, USA), the software used throughout this paper.
Once the supervised classification was completed, to prevent any strata from being less than 4.05 ha (10 acres) in size, an algorithm was applied to swap grid cells that were on the "edge" of each strata into neighboring strata (considering the nearness according to BA, height, Trees Per Hectare (TPH), and % conifer BA).
Further, on the X chromosome, motifs/oligomers related to X-chromosome inactivation may also accumulate in response to loss of functional genes on the Y (Carrel et al. 2006; Wilson Sayres and Makova 2013), and thus the sequence composition of each strata on the X diverges from neighboring regions that still undergo X-Y recombination.
After enumerating the households by residential zones in the urban areas, we determined an appropriate sample size for each stratum based on probability in proportion to population size.
4) Regional variation sampling (REGVAR) maximizes the number of randomly chosen organizational health care regions (n = 7) included for each stratum, based on the assumption that there is considerable variation between regions that must be reflected in the sample.
We then calculated the mean age at immigration into El Paso for each stratum based on the child's age at entry into first grade (10.2, 8.1, 4.25, 1.0, and 0, respectively).
We also extracted the relative percent error between the field plot sampling estimated ACD and the model ACD, and graphed this against each stratum on a hectare-by-hectare basis (Fig. 7).
Interventionists at each site selected participants from within each stratum on this list (with the goal of having approximately an equal number in each subgroup) until they had collected data on 35 participants for a total target number of 140.
