Rationale Strontium isotope (Sr-87/Sr-86) analysis of skeletal remains has become a powerful tool in archaeological studies of human migration and mobility. Owing to its resistance to post-mortem... Show moreRationale Strontium isotope (Sr-87/Sr-86) analysis of skeletal remains has become a powerful tool in archaeological studies of human migration and mobility. Owing to its resistance to post-mortem alteration, dental enamel is the preferred sampling material used for Sr-87/Sr-86 analysis in bioarchaeological provenance research, although recent studies have demonstrated that cremated bone is also generally resistant to diagenesis. This paper presents the results of a pilot study exploring the potential of unburnt petrous bone (pars petrosa) as a reservoir of biogenic (diagenetically unaltered) strontium, as the otic capsule or bony labyrinth within the petrous bone is extremely dense and is thought to be unable to remodel after early childhood, potentially providing an alternative for dental enamel. Methods From an individual from a colonial-era (18th century) site on the island of Saba in the Caribbean for whom previous enamel Sr-87/Sr-86 results had indicated non-local origins, multiple locations (n = 4) on the petrous were sampled and measured for strontium isotope composition. Saba (13 km(2)) has been extensively mapped for baseline strontium isotopes (n = 50) with Sr-87/Sr-86 varying from ca 0.7065 to 0.7090, whereas enamel Sr-87/Sr-86 (n = 3) ranged from 0.7104 to 0.7112. Results All four petrous Sr-87/Sr-86 ratios (0.7111-0.7122) are consistently and considerably higher than the local bioavailable range, and very similar to the enamel Sr-87/Sr-86. These results provide initial evidence that unburnt petrous bones may preserve biogenic strontium, at least in this specific burial context. Conclusions While more research in diverse burial conditions is needed to validate this observation, if confirmed, it would have broader implications for sample selection strategies in bioarchaeological studies using the strontium isotope method. Show less
Rationale Strontium isotope analysis can be applied to the calcined human otic capsule in the petrous part (pars petrosa ossis temporalis; PP) to gain information on childhood mobility in... Show moreRationale Strontium isotope analysis can be applied to the calcined human otic capsule in the petrous part (pars petrosa ossis temporalis; PP) to gain information on childhood mobility in archaeological and forensic contexts. However, only a thin layer of the otic capsule, the inner cortex, demonstrates virtually no remodelling. This paper proposes an improved sampling method for the accurate sampling of the inner cortex of the otic capsule to ensure that Sr-87/Sr-86 ratios related to early childhood are obtained.Methods Calcined rib and diaphyseal fragments and PP from ten cremation deposits are sampled for strontium isotope analysis, whereby our improved sampling strategy is applied to sample the inner cortex of the otic capsule. This allows inter- and intraskeletal Sr-87/Sr-86 comparison within an Iron Age collection from Oss, The Netherlands.Results Forty percent (4/10) of the calcined PP that were evaluated for this study show marked differences in Sr-87/Sr-86 (0.00035-0.00065) between the inner cortex and the bone sample surrounding this layer, the external cortex that has higher remodelling rates. Differences in Sr-87/Sr-86 between various skeletal elements also aided in the identification of the minimum number of individuals.Conclusions Our study demonstrates the problematic nature of the external cortex and stresses the need for a precise sampling method of the correct areas of the otic capsule. This can only be obtained by cutting the calcined PP midmodiolarly to enable adequate combustion degree assessment, and the correct identification and sampling of the inner cortex of the otic capsule. Show less
Plas-Duivesteijn, S.J. van der; Wulff, T.; Klychnikov, O.; Ohana, D.; Dalebout, H.; Veelen, P.A. van; ... ; Palmblad, M. 2016
ConclusionsThe results illustrate a broad applicability of the metric based on shared tandem mass spectra between LC/MS/MS datasets for analysing protein digests in different types of experiments.... Show moreConclusionsThe results illustrate a broad applicability of the metric based on shared tandem mass spectra between LC/MS/MS datasets for analysing protein digests in different types of experiments. There is no reason to assume that our instance of this method is optimal in any of these situations, as it makes limited or no use of accurate mass and chromatographic retention time. We propose that with further improvement and refinement, this type of analysis can be applied as a simple but informative first step in many pipelines for bottom-up tandem mass spectrometry data analysis in proteomics and other fields, comparing or analysing large numbers of samples or datasets. Copyright (c) 2016 John Wiley & Sons, Ltd. Show less
