Bacteria such as Mycobacterium tuberculosis are unique human pathogens in part because of their ability to persist in a dormant state and reactivate later.
RNA- and DNA viruses were examined because of their different abilities to persist and to rapidly generate new variants.
In cases where populations evolve reduced sensitivity to control efforts (e.g., herbicide), the derived populations could be considered to exhibit increased invasiveness because of their increased ability to persist in the altered environment relative to populations exhibiting wild-type sensitivity to control efforts.
Dioxins [polychlorinated dibenzo- p-dioxins (PCDDs)] belong to a group of chemicals identified as persistent organic pollutants (POPs) because of their tendency to resist degradation and persist in the environment.
These clones would be at a disadvantage because of their decreased transmissibility, but could persist for some time during an epidemic associated with high flea density.
The latter fail to persist because of their rapid removal by RNases H and Sen1 (Mischo et al., 2011; Wahba et al., 2011).
Because of their lipophilicity, organochlorines and PBDEs persist in the environment [ Arctic Monitoring and Assessment Programme (AMAP) 2004; Colborn et al. 1993; Damstra et al. 2002; de March et al. 1998].
In contrast, short-acting estrogens, such as estriol (E3), match long-acting estrogens in eliciting the early responses, but because of their pharmacokinetics they do not persist, and thus in vivo responses characteristic of later end points are blunted (Clark and Markaverich 1984; Katzenellenbogen 1984).
Evolutionary comparisons based on genetic data have become a powerful tool that scientists and physicians are now using to identify and understand genetic disorders and to identify genes that, because of their importance to life processes, have persisted for millions of years.
Although it has been suggested that TCM has a better capacity to replenish memory T cell pool and to mediate protective immunity than TEM because of their greater capacity to proliferate and persist in vivo, the findings of Huster et al. show that TEM is crucial for providing efficient protective immunity against Listeria monocytogenes infection [ 19].
