List of the 100 most densely populated cities in the United Kingdom, measured in people per square miles. 1  Portsmouth, Hampshire â 15,336. 2  London â 13,870. 3  Leicester, Leicestershire â 11,800. 4  Glasgow, Glasgow â 8,542. 5  Bristol, Bristol â 13,398. 6  Liverpool, Merseyside â 12,790. 7  Stoke-on-Trent, Staffordshire â 11,939.
In 1961 at the Wistar Institute in the US, Hayflick researched a phenomenon later called the Hayflick Limit, or the claim that normal human cells can only divide forty to sixty times before they cannot divide any further.
WI-38 cells began to be in high demand during the 1960s. Despite Hayflickâs recognition for the WI-38 cultures, he remained in the same associate position at the Wistar Institute, which was partially funded by the US National Institutes of Health (NIH) headquartered in Bethesda, Maryland.