The SPF% data presented here are inherently different from previously reported studies as the tumour (epithelial) cell fraction SPF% has been specifically calculated, not the total SPF%.
Although metaplastic Paneth cells expressing antimicrobial proteins such as cryptdins and lysozymes are known to appear in inflammed colons [ 41, 42], histological examination detected no such cells in the large intestines of SPF mice (data not shown).
Within this subset, the same result was observed as for the whole dataset, i.e. heritability estimates for average daily gain were lower under non-SPF than SPF conditions (p < 0.05) (data not shown).
Hence, we first estimated a SPF with pooled data by including a binary variable, Off_farm, as a regressor, which indicates whether the household participates or not in off-farm activities, and two separate SPF models, one for households participating in off-farm activities and the other for non- participants.
Heritabilities for CD8 antigen density measurements were similar under both SPF and non-SPF conditions (data not shown).
SPF handles dynamic input data structures (e.g., lists and trees) using lazy initialization [31].
Further data on SPF and latency time also give an explaination for findings of tumour biology in the very young women.
The expression of IFN-α s (α1, α2, α4), the end products of these signaling cascades, has also been analyzed but expression of IFN-αs was not detected in either SPF or GF mice (data not shown).
It is thus of decisive importance to be aware of these difficulties when calculating SPFs from flow cytometry data (Falkmer et al, 1990).
When applying these SPFs in a jurisdiction whose data were not used to develop the SPF, a calibration factor can be applied to adjust the expected crash frequency estimate to statewide or local conditions.
The uni-variate and bi-variate analyses for each trait were then repeated using data from either only SPF and non-SPF farms.
