A debt-to-GDP ratio of 60% is quite often noted as a prudential limit for developed countries. This suggests that crossing this limit will threaten fiscal sustainability. For developing and emerging economies, 40% is the suggested debt-to-GDP ratio that should not be breached on a long-term basis.
1 Telomerase is found in high levels in germline cells (egg and sperm) and stem cells. 2  In these cells telomere length is maintained after DNA replication and the cells do not show signs of ageing. 3  Telomerase is also found in high levels in cancer cells.
1 Every time a cell carries out DNA replication the chromosomes are shortened by about 25-200 bases (A, C, G, or T) per replication. 2  However, because the ends are protected by telomeres, the only part of the chromosome that is lost, is the telomere, and the DNA is left undamaged. Telomerase is an enzyme that adds the TTAGGG telomere sequence to the ends of chromosomes. 2  Telomerase is only found in very low concentrations in our somatic cells. 3  Because these cells do not regularly use telomerase they age leading to a reduction in normal function.