Collagen content dating updating firmware on linksys
C dating and isotope palaeodietary analysis of bone.The intactness and purity of the extracted gelatin (“collagen”) is strongly dependent on the extent of diagenetic degradation, contamination and the type of extraction method.Possible chemical, elemental and isotopic parameters for the assessment of “collagen” quality are discussed.The most important distinction that can be made is the one between contaminated bone (mostly from temperate zones), and bone low in collagen content (mostly from arid and tropical zones). In line with our preliminary report, the most likely explanation of our current findings is that there is an ongoing collagen type I biosynthesis in CAs because of dynamic remodeling comparable with a continuous attempt for fibrotic tissue repair to a previous event causing vessel wall instability and the aneurysm formation. Thus, biological data on collagen age and turnover in larger human CA cohorts in relation to cerebral arteries are lacking. M.); and Department of Surgery, University of Toronto, Toronto, Ontario, Canada (R. Although collagen type I is a main constituent of the CA wall, mechanical stability in cerebral arteries is maintained by a complex network of elastin; collagen types III, IV, and VI; and smooth muscle cells but without a significant contribution of collagen I. Ultimately, our findings also underline that the extracellular matrix and the biomechanical properties of CAs and cerebral arteries are fundamentally different.
In particular, when grouping the measured samples according to their C/N ratio, the agreement between C dates and archaeological evidence is good or inconsistent when the C/N ratio clearly falls inside or outside the “recommended” range, respectively, with a still reasonable agreement also when it is slightly above the upper limit of that range. Generally speaking, environmental conditions such as low p H level of soils, high temperatures, and percolating groundwaters, typical of arid and tropical zones, can affect the preservation of collagen; at the same time, bones recovered in such environments are more likely to be contaminated with carbon from the surrounding environment.Possible contamination of samples can also occur in temperate zones. However, because collagen I is the main constituent of CAs and because we generally excised and analyzed ≥2/3 of the aneurysm dome, the birth dating measurements are likely to reflect the majority of the aneurysmal mass. In addition, we can only estimate relative collagen turnover using radiocarbon birth dating as an indicator because the total collagen content in human CA samples cannot be monitored over time.