There are some cases where, if the results are somewhat variable, you think you’ve controlled for everything. This is another thing that you need to look at to make sure that you’ve accounted for it. . . . Don’t ignore it anymore.
Our study shows that bearded men harbour significantly higher burden of microbes and more human-pathogenic strains than dogs.—Andreas Gutzeit et al., authors of a recent paper comparing the microbial assemblages present in 18 human beards and microbes in the fur on 30 dogs to assess the safety of using MRI machines on patients after canines had been scanned (Eur Radiol, 29:527–34, 2019)
1. Element in an Einstein equation
1. What can make liquid flow uphill