Our traces are left behind in the patterns of data littering everything from flash cards, thumb drives, RAM, and hard drives".
For all developmental and reproductive data, the litter was considered the experimental unit; for example, litter means and frequencies per litter were used as the experimental units for analyzing pup weights and pup examination data.
Data of litter size (total number born per litter) for 338,346 sows were analyzed.
Data of litter size (total number born per litter) for 338,346 sows, of which 1,919 were genotyped using the Illumina PorcineSNP60 BeadChip, were analyzed.
Published data for litter production were generally presented as mass of material, for conversion to C inputs a 50% C content was assumed [ Wright et al., 2013].
Contingency tables of categorical data on litter sizes and pup weight at weaning (3 × 4 and 2 × 3 tables, respectively) were analyzed by χ-test.
Finally, we statistically clustered our data by litter, a method not used in many earlier BPA studies, which represents a significant criticism of and barrier to interpretation of prior studies.
Analysis of data from litter-bag experiments suggests that a significant portion of the litter is lost in the first few years owing primarily to rapid initial decomposition processes, including movement/leaching of soluble materials.
Because of missing data, two litters were excluded from the analysis of eye-opening: One litter in Fish High PCB with 7 pups on PND12 and one litter in Casein High PCB with 7 pups on PND13.
When looking for effects using litters of mice, it is important to consider that as the sampling of embryos naturally groups the data as litters, one might expect effects to be observed not only across an entire population, but perhaps that certain effects are also clustered within litters.
