An ideal solution? Optimising pretreatment methods for artificially mummified ancient Egyptian tissues.

RATIONALE: Although the analysis of skeletal remains dominates the study of ancient dietary stable isotopes, mummified bodies also allow short-term diet to be studied through the analysis of soft tissues. The application of resins, waxes and oils during mummification can affect the results obtained. This study assesses a range of methods for removing such substances from mummified tissue. METHODS: An experimental mummification model following ancient Egyptian methods was created using a modern pig leg. Sub-samples of skin, muscle and bone were removed and coated with a range of substances used in Egyptian mummification. Four methods were used to clean these samples before the measurement of the carbon and nitrogen stable isotope ratios of their gelatinised collagen content using a ThermoFinnigan Flash Elemental analyser coupled to a DeltaPlus XL isotope ratio mass spectrometer via a ConFlo III interface. RESULTS: The results showed that embalming materials can significantly affect dietary stable isotope ratios, and that these substances are most effectively removed using a mixture of polar and non-polar solvents. Results indicate that bone samples demineralised with HCl and skin samples produce more accurate results than bone samples demineralised with EDTA or muscle samples. CONCLUSIONS: The choice of tissue and the preparation methods used can have a significant effect on the accuracy of stable isotope data obtained from mummified tissue, particularly when embalming materials are also present. A mixture of solvents appears to be a more effective cleaning agent than a single solvent. Demineralisation with HCl is preferable for well-preserved bone, as used in this study, but whether this is the case for more fragile, less well-preserved bone requires further study. Skin samples produce more consistent data than muscle, but visually distinguishing between these tissues is not simple on ancient mummies.

Beach litter sources around Nuuk, Greenland: An analysis by UArctic summer school graduate course students.

Modeling studies illustrate the potential for long-range transport of plastics into the Arctic, although the degree to which this occurs remains relatively undocumented. We utilised a teaching exercise at a UArctic summer school graduate course in Nuuk, Greenland to conduct a preliminary in-depth analysis of beach litter sources in the Nuup Kangerlua fjord. Students and instructors collected and analysed 1800 litter items weighing 200 kg from one location in the fjord and another at its mouth. The results suggest a predominance of local sources to macrolitter, rather than long-range transport from Europe. Fisheries-related items and rope were common. Packaging which could be identified was largely suspected to be products distributed in Greenland, and soft plastics, which rarely disperse far from its source, were also common. The results suggest local measures to reduce mismanaged waste and emissions from fisheries are important for reducing marine litter in West Greenland.

Variations in immunohistochemical preservation of proteins in a mummification model.

Immunohistochemistry is an important tool in the investigation of ancient mummified remains because of its ability not only to detect proteins but also to isolate their location to specific tissues and thereby improve confidence that the results are genuine. A mouse model of Egyptian mummification has been used to demonstrate that the survival of proteins, judged by the retention of immunohistochemical staining, varies markedly. Some survive the process well, whereas others become barely detectable despite the morphology of the tissue being excellently preserved. The results obtained show that protein preservation is multi-factorial, with tissue type and degradation, and the properties of the protein itself all having significant effects. Proteins forming large, multi-subunit complexes such as collagen IV appear to be more resistant to degradation than those that do not, such as S-100. Although modern modelling studies cannot replicate the full extent of degradative processes and taphonomic changes experienced by real mummies, the results obtained can be useful for guiding research that requires ancient tissues.

Exploring public views on marine litter in Europe: Perceived causes, consequences and pathways to change.

Marine litter is a global challenge and society plays an important role via lifestyles and behaviour, including policy support. We analysed public perceptions of marine litter and contributing factors, using data from 1133 respondents across 16 European countries. People reported high levels of concern about marine litter, and the vast majority (95%) reported seeing litter when visiting the coast. The problem was attributed to product and packaging design and behaviour rather than lack of facilities or accidental loss of items. Retailers, industry and government were perceived as most responsible, but also least motivated and competent to reduce marine litter, whereas scientists and environmental groups were perceived as least responsible but most motivated and competent. Regression analyses demonstrated the importance of psychological factors such as values and social norms above sociodemographic variables. These findings are important for communications and interventions to reduce inputs of marine litter to the natural environment.