We address the mechanism by which adult intestinal stem cells (ISCs) become localized to the base of each villus during embryonic development. We find that, early in gut development, proliferating progenitors expressing ISC markers are evenly distributed throughout the epithelium, in both the chick and mouse. However, as the villi form, the putative stem… (More)
In this paper, we present a password stretching method using user specific salts. Our scheme takes similar time to stretch a password as recent password stretching algorithms, but the complexity of a pre-computation attack increases by 10^8 times and the storage required to store the pre-computation result increases by 10^8 times.