The strange case of Apigliano: early ‘fossilization’ of medieval bone in southern Italy

The preservation of the osteological material at the medieval site of Apigliano, in southern Italy, is characterized by bones with highly crystalline, and altered, mineral phases. In addition to this, some material retains perfect histological preservation, with the exception of small microfissures present throughout this structure. Diagenetic porosity is indicative of collagen loss via chemical degradation. The levels of residual collagen in these bones are much lower than is predicted from simple models of gelatinization, and thus a more complex explanation for the state of preservation must be sought. Possible explanations for the rapid loss of bone collagen are considered, including a high–temperature event, the acceleration of hydrolysis due to liming and extreme wetting and drying cycles.     

The taphonomy of cooked bone: characterizing boiling and its physico–chemical effects

Cooking is perhaps the most common pre–burial taphonomic transformation that occurs to bone, yet it is still one of the least understood. Little progress has been made in determining a method of identifying cooked bone in the archaeological record, despite its import for various branches of archaeology. This paper attempts to describe boiling in terms of its physico–chemical effects on bone, and uses a suite of diagenetic indicators to do this. It is shown that cooking for brief periods of time has little distinguishable effect on bone in the short term, but that increased boiling times can mirror diagenetic effects observed in archaeological bone. The relationship between the loss of collagen and alterations to the bone mineral is explored through heating experiments, and the results compared with archaeological data.The possibility of boiling being used as an analogue for bone diagenesis in future studies is raised, and the key relationship between protein and mineral is once again highlighted as vital to our understanding of bone diagenesis.     

Bone preservation and DNA amplification

The use of ancient DNA has increased during the past two decades in several scientific disciplines. However, the underlying mechanisms of DNA degradation in bone tissue are poorly understood. Here we address the importance of hydroxyapatite and collagen for DNA preservation in bone. We used two series of bones and teeth, one set of modern experimentally degraded bovid bones and one set of ancient horse bones/teeth. From these samples, we measured crystallinity, DNA presence and extracted collagen. The mtDNA fragments, parts of cytochrome b and the D–loop were amplified and sequenced. Our results show that presence of DNA was strongly related to the crystallinity in the hydroxyapatite and to the amount of collagen. This suggests that the hypothesis that hydroxyapatite has a crucial role in DNA preservation in calcified tissue is valid; and hydroxyapatite and collagen can be used to indicate whether DNA is present in the material. This is what would be expected if DNA is adsorbed to and stabilized by hydroxyapatite in calcified tissue, and collagen is part of the complex system that preserves DNA in bone tissue. Further, since collagen is the preferred material for radiocarbon dating, such bones may be a starting–point for a DNA analysis.     

Combining Geostatistical Methods and Hierarchical Scene Models for Analysis of Multiscale Variation in Spatial Data

Concepts from Hierarchical Analysis of Variance (ANOVA) can be combined with ideas from geostatistics to describe the multiscale structure of spatial data. Hierarchical ANOVA involves modeling spatial data as the sum of effects associated with processes acting at different spatial scales. These effects can be modeled as stationary regionalized variables, whose spatial structure can be described using the variogram. According to this model, the variogram of the spatial data is the sum of variograms and cross‐variograms of the effects. Whereas hierarchical ANOVA reveals the relationship between scale and variability, the hierarchical decomposition of the variogram relates scale with spatial structure. This analysis method can reveal otherwise undetected features of spatial data, and can guide further analysis.     

Rapid loss of endogenous DNA in pig bone buried in five different environments

The rate at which endogenous DNA from differently prepared (butchered, boiled and baked) compact pig bones degrades in five different Danish terrestrial and marine environments over 12 months was investigated. Although > 70% of the estimated endogenous mtDNA is lost after just four weeks of exposure, no cytosine deamination of DNA was recognised. A correlation between the presence of oxygen and the amount of preserved DNA was observed. The results provide valuable information on the interaction between the endogenous DNA and the depositional environment in the early stages of bone diagenesis, which can be a support in the interpretation of the initial diagenetic pathways of archaeological bone.     

A novel and non-destructive approach for ZooMS analysis: ammonium bicarbonate buffer extraction

Bone collagen is found throughout most of the archaeological record. Under experimental conditions, collagen is apparently preserved as an intact molecule, with amino acid compositions and isotopic profiles only changing when almost all of the protein is lost. The ubiquity of collagen in archaeological bone has lead to the development of the use of collagen peptide mass fingerprints for the identification of bone fragments—Zooarchaeology by Mass Spectrometry (ZooMS). We report a novel, but a simple method for the partial extraction of collagen for ZooMS that uses ammonium bicarbonate buffer but avoids demineralisation. We compared conventional acid demineralisation with ammonium bicarbonate buffer extraction to test ZooMS in a range of modern and archaeological bone samples. The sensitivity of the current generation of mass spectrometers is high enough for the non-destructive buffer method to extract sufficient collagen for ZooMS. We envisage that a particular advantage of this method is that it leaves worked bone artefacts effectively undamaged post-treatment, suitable for subsequent analysis or museum storage or display. Furthermore, it may have potential as a screening tool to aid curators in the selection of material for more advanced molecular analysis—such as DNA sequencing.     

Film production incentives,employment transformation and domestic expenditure in South Africa: visualizing subsidy effectiveness

In 2004 the South African Department of Trade and Industry (DTI) introduced a Film and Television Production Rebate Programme. In order to qualify for the rebate, certain criteria have to be met including success in job creation and skills development within the industry, alongside a particular focus on the percentage of ‘historically disadvantaged individuals’ employed. This study sets out the issues associated with evaluating success in meeting these various criteria and is, to the best of our knowledge, the first study to apply multi-criteria visualization techniques to inform the evaluation of public subsidy effectiveness. The ‘PROMETHEE’ method is applied and apart from presenting project performance in a visually intuitive manner, the approach helps to clarify patterns of relative success, show where policy objectives are competing, and to identify project exemplars for more efficiently guiding future public support in the sector.