These variations can be linked to different and/or shifting production centres, thus turning beads into useful chronological markers of archaeological sites [2 6].
Nonetheless, many of these tephras could be identified, and they have provided important links between palaeoenvironmental records across the North Atlantic, as well as acting as high-precision chronological markers for the Dosenmoor sequence itself.
Recently, with the aid of cosmogenic nuclides analysis (Zhou et al. 2010), reassessment of the BGE and LGE excursions in some of the classic sections on the CLP revealed a record of geomagnetic intensity that is consistent with the record in marine sediments, thus affirming the potential value of geomagnetic excursions as important chronological markers in Quaternary sediments.
The large faceted hexagonal beads, which were made in Bohemia (Czechoslovakia), as well as the single-wound annular (ring) beads mainly made in Germany (top row Fig. 7), appeared in southern Africa in the nineteenth century and are therefore useful chronological markers [2].
If these frequently reported sites are only markers of chronological age, markers of biological age are yet to be identified.
The hypothesis of telomere erosion as a chronological aging marker has been well documented by many investigations linking the telomere lengths to the biological age.
Chronological age as surrogate marker for intrinsic ageing has the most important influence on most facial skin ageing signs.
With immunofluorescence, we were able to co-localise Sir3p and Rap1p signals with nucleolar Nop2p, which may be considered a nucleolar marker, during chronological aging (Fig. 5a, b).
(ii) Determine whether a marker of chronological age also discriminates individuals with a youthful or old level relative to their age category in the general population, which would indicate that the quantitative parameter potentially marks biological age (Fig. 2).
That is, although a number of studies had reported somatic mtDNA mutations in aged persons (as described above), it was possible that these were simply a marker of chronological rather than biological age.
