Suchergebnisse

Collagen is the main structural and most abundant protein in the human body, and it is routinely extracted and analysed in scientifc archaeology. Its degree of preservation is, therefore, crucial and several approaches are used to determine it. Spectroscopic techniques provide a cost-efective, non-destructive method to investigate the molecular structure, especially when combined with multivariate statistics (chemometric approach). In this study, we used FTIR-ATR spectroscopy to characterise collagen extracted from skeletons recovered from necropoleis in NW Spain spanning from the Bronze Age to eighteenth century AD. Principal components analysis was performed on a selection of bands and structural equation models (SEM) were developed to relate the collagen quality indicators to collagen structural change. Four principal components represented: (i) Cp1, transformations of the backbone protein with a residual increase in proteoglycans; (ii) Cp2, protein transformations not accompanied by changes in proteoglycans abundance; (iii) Cp3, variations in aliphatic side chains and (iv) Cp4, absorption of the OH of carbohydrates and amide. Highly explanatory SEM models were obtained for the traditional collagen quality indicators (collagen yield, C, N, C:N), but no relationship was found between quality and δ13C and δ15N ratios. The observed decrease in C and N content and increase in C:N ratios is controlled by the degradation of protein backbone components and the relative preservation of carbon-rich compounds, proteoglycans and, to a lesser extent, aliphatic moieties. Our results suggest that FTIR-ATR is an ideal technique for collagen characterization/pre-screening for palaeodiet, mobility and radiocarbon research. ; Project "Galician Paleodiet" ED481D 2017/014 ; Consiliencia network ED 431D2017/08 ; GPC ED341B 2018/20 ; "Antropoloxia dos restos oseos humanos de Galicia" (Direccion Xeral de Patrimonio Historico), Xunta de Galicia ; Plan Galego I2C mod.B ED481D 2017/014 ; Instituto de Salud Carlos III Spanish Government PID2019-111683RJ-100

Data in this article are related to the chemical characterization ofvarious oak wood samples. Data have been obtained by theapplication of Fourier Transform Infrared (FTIR) spectroscopy andpyrolysis-gas chromatography-mass spectrometry (Py–GC–MS) toliving tree species and shipwreck wood fragments. Measurementswere performed on individual rings in order to facilitate theunderstanding of the variability in wood chemical compositionalong the radial cores, i.e. the same kind of material traditionallyused for dendrochronological analysis. The data in this article islabelled according to the anatomical sections of the wood (sap-wood, transition wood and heartwood) where the samples weretaken. The experimental background and the results can be foundin the related research article,"Chemometric tools for identifica-tion of wood from different oak species and their potential forprovenancing of Iberian shipwrecks (16th–18th centuries CE)"(Traoré et al., 2018) ; This study was developed within the framework of the ForSEAdiscovery project funded from the People Programme (Marie Curie Actions) of the European Union's Seventh Framework Programme (FP72007-2013) under REA Grant agreement no. PITN-GA2013-607545 ; SI

Wetland environments have been important resources for human habitation since prehistoric times and in parts of northern Europe these have witnessed the construction of artificial islet settlements, known as 'crannogs' in Scotland and Ireland. This paper presents a high-resolution multi-proxy palaeoenvironmental study from the Loch of Leys, Aberdeenshire, Scotland, the site of a recently excavated crannog that provides a chronological context for its inhabitation. The combined datasets demonstrate that the first occupation from AD 20-210 coincided not only with a transitional phase from lake to wetland (mire) but also with the timing of the first major Roman campaigns in northeast Scotland. Techniques including microfossil analysis, geochemistry, IR-spectroscopy and physical properties integrated with archaeological and historical records have helped to better define both natural changes that took place in the wetland environment and human activity (agriculture, fires, metal working) spanning the Roman Iron Age through to the present. This has allowed a better understanding of the responses of existing Iron Age communities to Roman military activity (e.g. through continuity or change in land use) as well as the resources exploited in frontier zones during the Roman and post Roman eras. This has wider significance not just for Scotland but also for other parts of Europe that had similar frontiers and conflict zones during the Roman period.

The Mediterranean seagrass Posidonia oceanica maintains a biodiverse ecosystem and it is a world-wide important carbon sink. It grows for millennia, accumulating organic-rich soils (mats) beneath the meadows. This marine habitat is protected by the European Union; however, it is declining rapidly due to coastal development. Understanding its response to disturbances could inform habitat restoration, but many environmental impacts predate monitoring programs (years). This research explores the palaeoecological potential of Posidonia mats to reconstruct six thousand years of environmental change that could have affected Posidonia meadows and, in turn, left an imprint on the mats. Palynological, microcharcoal, magnetic susceptibility and glomalin-related soil protein (GRSP) analyses on Posidonia mats enabled us to detect climate- and human-induced environmental processes impacting on the seagrass during the Late Holocene. The pollen and microcharcoal records reconstructed anthropogenic disturbances attributed to agriculture. The record of GRSP shows that agrarian activities affected continental soil quality. Changes in magnetic susceptibility reveal that enhanced soil erosion was caused by both climate (major flooding events in the NW Mediterranean) and humans (cultivation) which impacted on the Posidonia mat. Finally, increased human impact is linked to eutrophication of coastal waters since Roman-Medieval times. Synthesis. This study shows that climate and land-use changes in the western Mediterranean resulted in enhanced loadings of terrigenous material to the coastal zone since the Late Holocene, likely disturbing the Posidonia meadows and their mat carbon accumulation dynamics. Under the current global change scenario in which CO2 emissions are projected to increase, restoring carbon sinks is a priority. Seagrass habitat restoration should consider not only the coastal perturbations, but also the continental ones at a catchment scale to preserve the socio-economic ecosystem services provided by seagrasses.

1. The Mediterranean seagrass Posidonia oceanica maintains a biodiverse ecosystem and it is aworld-wide important carbon sink. It grows for millennia, accumulating organic-rich soils (mats)beneath the meadows. This marine habitat is protected by the European Union; however, it is declin-ing rapidly due to coastal development. Understanding its response to dist urbances could informhabitat restoration, but many environmental impacts predate monitoring programs (<50 years).2. This research explores the palaeoecological potential of Posidonia mats to reconstruct six thou-sand years of environmental change that could have affected Posidonia meadows and, in turn, leftan imprint on the mats.3. Palynological, microcharcoal, magnetic susceptibility and glomalin-related soil protein (GRSP)analyses on Posidonia mats enabled us to detect climate- and human-induced environmentalprocesses impacting on the seagrass during the Late Holocene.4. The poll en and microcharcoal records reconstructed anthropogenic disturbances attributed to agri-culture. The record of GRSP shows that agrarian activities affected continental soil quality. Changesin magnetic susceptibility reveal that enhanced soil erosion was caused by both climate (major flood-ing events in the NW Mediterranean) and humans (cultivation) which impacted on the Posidoniamat. Finally, increased human impact is linked to eutrophication of coastal waters since Roman-Medieval times.5. Synthesis. This study shows that climate and land-use changes in the western Mediterraneanresulted in enhanced loadings of terrigenous material to the coastal zone since the Late Holocene,likely disturbing the Posidonia meadows and their mat carbon accumulation dynamics. Under thecurrent global change scenario in which CO2emissions are projected to increase, restoring carbonsinks is a priority. Seagrass habitat rest oration should consi der not only the coastal perturbations,but also the continenta l ones at a catchment scale to preserve the socio-economic ecosystem servicesprovided by seagrasses ; Full Text

Date of Acceptance: 05/06/2015 This research was made possible through funding provided by the Leverhulme Trust, the Spanish Ministry of Science and Innovation (Project CGL2010–20672) and Xunta de Galicia (grants R2014/001 and GPC2014/009). N Silva-Sánchez is currently supported by a FPU pre-doctoral grant (AP2010–3264) funded by the Spanish Government. Kirsty Golding, Andy McMullen, and Ian Simpson are thanked for their assistance with fieldwork. Alison Sandison produced the maps. Pete Langdon and two anonymous referees are thanked for comments that helped to improve the paper. ; Peer reviewed ; Postprint

The Mediterranean seagrass Posidonia oceanica maintains a biodiverse ecosystem and it is a world-wide important carbon sink. It grows for millennia, accumulating organic-rich soils (mats) beneath the meadows. This marine habitat is protected by the European Union; however, it is declining rapidly due to coastal development. Understanding its response to disturbances could inform habitat restoration, but many environmental impacts predate monitoring programs (<50 years). This research explores the palaeoecological potential of Posidonia mats to reconstruct six thousand years of environmental change that could have affected Posidonia meadows and, in turn, left an imprint on the mats. Palynological, microcharcoal, magnetic susceptibility and glomalin-related soil protein (GRSP) analyses on Posidonia mats enabled us to detect climate- and human-induced environmental processes impacting on the seagrass during the Late Holocene. The pollen and microcharcoal records reconstructed anthropogenic disturbances attributed to agriculture. The record of GRSP shows that agrarian activities affected continental soil quality. Changes in magnetic susceptibility reveal that enhanced soil erosion was caused by both climate (major flooding events in the NW Mediterranean) and humans (cultivation) which impacted on the Posidonia mat. Finally, increased human impact is linked to eutrophication of coastal waters since Roman-Medieval times. Synthesis. This study shows that climate and land-use changes in the western Mediterranean resulted in enhanced loadings of terrigenous material to the coastal zone since the Late Holocene, likely disturbing the Posidonia meadows and their mat carbon accumulation dynamics. Under the current global change scenario in which CO2 emissions are projected to increase, restoring carbon sinks is a priority. Seagrass habitat restoration should consider not only the coastal perturbations, but also the continental ones at a catchment scale to preserve the socio-economic ecosystem services provided by ...