225 research outputs found
Radiocarbon dating of a multi-phase passage tomb on Baltinglass Hill, Co. Wicklow, Ireland
Baltinglass is a multi-chamber Neolithic passage tomb in Co. Wicklow, Ireland, excavated in the 1930s. This paper presents the results of a radiocarbon dating programme on charred wheat grains and hazelnut shell found underlying the cairn, and on cremated human bone found within and near two of the monumentâs five chambers. The results are surprising, in that three of the six determinations on calcined bone pre-date by one or two centuries the charred cereals and hazelnut shells sealed under the cairn, dating to c. 3600â3400 cal bc. Of the remaining three bone results, one is coeval with the charred plant remains, while the final two can be placed in the period 3300/3200â2900 cal bc, that is more traditionally associated with developed passage tombs. A suggested sequence of construction is presented beginning with a simple tomb lacking a cairn, followed by a burning event â perhaps a ritual preparation of the ground â involving the deposition of cereal grains and other materials, very rapidly and intentionally sealed under a layer of clay, in turn followed by at least two phases involving the construction of more substantial chambers and associated cairns. What was already a complex funerary monument has proven to be even more complex, with a history spanning at least six centuries
Late Glacial and Early Holocene human demographic responses to climatic and environmental change in Atlantic Iberia
Successive generations of hunter-gatherers of the Late Glacial and Early Holocene in Iberia had to contend with rapidly changing environments and climatic conditions. This constrained their economic resources and capacity for demographic growth. The Atlantic façade of Iberia was occupied throughout these times and witnessed very significant environmental transformations. Archaeology offers a perspective on how past human population ecologies changed in response to this scenario. Archaeological radiocarbon data are used here to reconstruct demographics of the region over the long term. We introduce various quantitative methods that allow us to develop palaeodemographic and spatio-temporal models of population growth and density, and compare our results to independent records of palaeoenvironmental and palaeodietary change, and growth rates derived from skeletal data. Our results demonstrate that late glacial population growth was stifled by the Younger Dryas stadial, but populations grew in size and density during the Early to Middle Holocene transition. This growth was fuelled in part by an increased dependence on marine and estuarine food sources, demonstrating how the environment was linked to demographic change via the resource base, and ultimately the carrying capacity of the environment. This article is part of the theme issue 'Cross-disciplinary approaches to prehistoric demography'.FCT: DL 57/2016/CP1361/CT0026info:eu-repo/semantics/publishedVersio
Radiocarbon Dated Trends and Central Mediterranean Prehistory
Abstract: This paper reviews the evidence for long term trends in anthropogenic activity and population dynamics across the Holocene in the central Mediterranean and the chronology of cultural events. The evidence for this has been constituted in a database of 4608 radiocarbon dates (of which 4515 were retained for analysis following initial screening) from 1195 archaeological sites in southern France, Italy and Malta, spanning the Mesolithic to Early Iron Age periods, c. 8000 to 500 BC. We provide an overview of the settlement record for central Mediterranean prehistory and add to this an assessment of the available archaeological radiocarbon evidence in order to review the traditional narratives on the prehistory of the region. This new chronology has enabled us to identify the most significant points in time where activity levels, population dynamics and cultural change have together caused strong temporal patterning in the archaeological record. Some of these episodes were localized to one region, whereas others were part of pan-regional trends and cultural trajectories that took many centuries to play out fully, revealing prehistoric societies subject to collapse, recovery, and continuing instability over the long-term. Using the radiocarbon evidence, we model growth rates in the various regions so that the tempo of change at certain points in space and time can be identified, compared, and discussed in the context of demographic change. Using other published databases of radiocarbon data, we have drawn comparisons across the central Mediterranean to wider prehistoric Europe, and northern Africa. Finally, we include a brief response to the synchronously published but independently developed paper (Palmisano et al. in J World Prehist 34(3), 2021). While there are differences in our respective approaches, we share the general conclusions that large-scale trends can been identified through meta-analyses of the archaeological record, and these offer new perspectives on how society functioned
Glial sulfatides and neuronal complex gangliosides are functionally interdependent in maintaining myelinating axon integrity
Sulfatides and gangliosides are raft-associated glycolipids essential for maintaining myelinated nerve integrity. Mice deficient in sulfatide (cerebroside sulfotransferase knockout, CST-/- ) or complex gangliosides (ÎČ-1,4-N-acetylegalactosaminyltransferase1 knockout, GalNAc-T-/- ) display prominent disorganization of proteins at the node of Ranvier (NoR) in early life, and age-dependent neurodegeneration. Loss of neuronal rather than glial complex gangliosides underpins the GalNAc-T-/- phenotype, as shown by neuron or glial-specific rescue, whereas sulfatide is principally expressed and functional in glial membranes. The similarities in NoR phenotype of CST-/- , GalNAc-T-/- and axo-glial protein deficient mice suggests these glycolipids stabilise membrane proteins including neurofascin155 (NF155) and myelin-associated glycoprotein (MAG) at axo-glial junctions. To assess the functional interactions between sulfatide and gangliosides, CST-/- and GalNAc-T-/- genotypes were interbred. CST-/- x GalNAc-T-/- mice develop normally to P10, but all die between P20-P25, coinciding with peak myelination. Ultrastructural, immunohistological and biochemical analysis of either sex reveals widespread axonal degeneration and disruption to the axo-glial junction at the NoR. In addition to sulfatide-dependent loss of NF155, CST-/-x GalNAc-T-/- mice exhibited a major reduction in MAG protein levels in CNS myelin, compared to wild type and single lipid deficient mice. The CST-/- x GalNAc-T-/- phenotype was fully restored to that of CST-/- mice by neuron-specific expression of complex gangliosides, but not by their glial-specific expression nor by the global expression of a-series gangliosides. These data indicate that sulfatide and complex b-series gangliosides on the glial and neuronal membranes respectively act in concert to promote NF155 and MAG in maintaining the stable axo-glial interactions essential for normal nerve function.SIGNIFICANCE STATEMENTSulfatides and complex gangliosides are membrane glycolipids with important roles in maintaining nervous system integrity. Node of Ranvier maintenance in particular requires stable compartmentalisation of multiple membrane proteins. The axo-glial adhesion molecules neurofascin 155 and myelin-associated glycoprotein require membrane microdomains containing either sulfatides or complex gangliosides to localise and function effectively. The co-operative roles of these microdomains and associated proteins are unknown. Here we show vital interdependent roles for sulfatides and complex gangliosides as double (but not single) deficiency causes a rapidly lethal phenotype in early age. These findings suggests that sulfatides and complex gangliosides on opposing axo-glial membranes are responsible for essential tethering of the axo-glial junction proteins, neurofascin155 and myelin-associated glycoprotein that interact to maintain the nodal complex
Impacts of Early Holocene environmental dynamics on open-air occupation patterns in the Western Mediterranean: insights from El Arenal de la Virgen (Alicante, Spain)
Open-air sites represent a fundamental proxy of the Early Holocene adaptive systems in the Iberian Peninsula. However, its research potential for the study of humanâenvironmental interactions has been minimally explored. In this work, we present the results of an integrated research programme focused on open-area excavations at the Mesolithic site of Arenal de la Virgen (Alicante, Spain). Novel multi-scalar geoarchaeological and archaeo-stratigraphic studies, coupled with featured-based palaeobotanical analysis, were used to design an extensive radiocarbon dating programme and produce different Bayesian chronological models. Our results distinguish two different Mesolithic occupation phases, dating to 9.3â9.1 and 8.6â8.3k cal a bp respectively, consisting of combustion features and lithic scatters. The comparison of occupational dynamics with the nearby palaeoecological records of Salines and Villena indicated that both Mesolithic phases occurred under relatively stable environmental conditions. The second Mesolithic phase, however, ended during the onset of the 8.2k cal a bp climatic event, when sedimentation processes shifted from soil formation to accretion of aeolian sands. We demonstrate that the end of the Mesolithic occupations at Arenal de la Virgen coincides with the cessation of radiocarbon-dated activity in other open-air Postglacial sites in the central Mediterranean region of Iberia.This research is primarily part of a project that has received funding from the European Research Council (ERC) under the Horizon 2020 research and innovation programme (Grant agreement No. 683018) to JFLdP. Additional analyses on the pollen data sets have been produced in the context of the research project HAR2017-88503-P supported by the Spanish Ministry of Science and Innovation. JFLdP is additionally supported by the Plan Gen-T programme (Ref.CIDEGENT-18/040) from the Generalitat Valenciana. JRR is currently supported by a Margarita Salas fellowship (ref. MARSALAS21-22) at the University of Alicante, and AP-D is holder of a MarĂa Zambrano fellowship at the University of the Basque Country (UPV/EHU) both funded by the European Union-Next Gene and the Ministry of Universities (Government of Spain)
Island questions: the chronology of the Brochtorff Circle at Xagħra, Gozo, and its significance for the Neolithic sequence on Malta
Bayesian chronological modelling of radiocarbon dates from the Brochtorff Circle at Xagħra, Gozo, Malta (achieved through the ToTL and FRAGSUS projects), provides a more precise chronology for the sequence of development and use of a cave complex. Artefacts show that the site was in use from the Ć»ebbuÄĄ period of the late 5th/early 4th millennium cal BC to the Tarxien Cemetery phase of the later 3rd/early 2nd millennia cal BC. Absolutely dated funerary activity, however, starts with a small rock-cut tomb, probably in use in the mid to late fourth millennium cal BC, in the Ä gantija period. After an interval of centuries, burial resumed on a larger scale, probably in the 30th century cal BC, associated with Tarxien cultural material, with the use of the cave for collective burial and other depositions, with a series of structures, most notably altar-like settings built from massive stone slabs, which served to monumentalise the space. This process continued at intervals until the deposition of the last burials, probably in the 24th century cal BC; ceremonial activity may have ended at this time or a little later, to be followed by occupation in the Tarxien Cemetery period. The implications for the development of Neolithic society on Malta are discussed, as well as the changing character of Neolithic Malta in comparison to contemporary communities in Sicily, peninsular Italy and southern Iberia. It is argued that underground settings and temples on Malta may have served to reinforce locally important values of cooperation and consensus, against a wider tide of differentiation and accumulation, but that there could also have been increasing control of the treatment of the dead through time. The end of the Maltese Neolithic is also briefly discussed
Is alignment enough? Investigating the effects of state policies and professional development on science curriculum implementation
Implementation of science curriculum materials has been a fundamental challenge in science education for decades. Policy researchers have argued that alignment of standards, curriculum, and assessment are the key to supporting implementation. This paper focuses on teachers' perceptions of curricular alignment and on curriculum implementation using empirical data from a statewide systemic inquiry science reform effort targeting students from kindergarten to eighth grade. We find that the success of alignment policies depends on teachers' construal of the relationship between standards and curriculum materials and on allocation of time for planning at the school level. © 2008 Wiley Periodicals, Inc. Sci Ed 93: 656â677, 2009Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63036/1/20321_ftp.pd
Sex Determination and Isotopic Analysis of the NivÄfjord Mesolithic Burials, Zealand, Denmark
Since 1992 the prehistoric NivÄfjord in northeast Zealand, Denmark, has yielded an appreciable number of inhumation burials and cremations dating to the Mesolithic, especially the sites of NivÄ 10 and NivÄgÄrd. Unfortunately, the micro-region is characterised by poor organic preservation, restricting the successful application of biomolecular techniques to human remains, including large-scale radiocarbon dating programmes as well as both stable isotope and ancient DNA analyses. Here, we apply an alternative technique, an acid etch peptide-based method, to determine the sex of eight individuals from NivÄ 10 as well as the NivÄgÄrd child. Moreover, we revisit the utility of stable carbon (Ύ13C), nitrogen (Ύ15N) and sulfur (Ύ34S) isotope analysis of human tissues to reconstruct the life histories and diets of 10 individuals from NivÄ 10 as well as the NivÄgÄrd child. To contextualise further, we sampled 14 Capreolus capreolus and three Sus scrofa from the NivÄgÄrd site for stable isotope analysis. We demonstrate that sex can successfully be determined from contexts susceptible to poor organic preservation, and show that the NivÄgÄrd child spent a proportion of its life outside a sea spray-influenced environment, and consumed significant quantities of marine protein as demonstrated by its Ύ13C and Ύ34S values
Analysis of periosteal lesions from commingled human remains at the Xagħra Circle hypogeum reveals the first case of probable scurvy from Neolithic Malta
Funder: FP7 Ideas: European Research Council; Id: http://dx.doi.org/10.13039/100011199; Grant(s): 323727Funder: Magdalene College, University of Cambridge; Id: http://dx.doi.org/10.13039/501100000653Funder: Arts and Humanities Research Council; Id: http://dx.doi.org/10.13039/501100000267Abstract: Objectives: Palaeopathological analysis is key for characterising population health at the individual level and across large assemblages but is rarely exploited to unite the remains of disarticulated individuals. This study explores the potential for individual identification through differential diagnosis of periosteal lesions in a commingled deposit, both to ascertain the number of individuals represented and provide a differential diagnosis. Materials and Methods: The late Neolithic Xagħra Circle hypogeum on Gozo contains the remains of more than 800 individuals, most of which were transformed to a collective disarticulated assemblage. Across the excavated population, pathological observations are strikingly low. In one specific 1 Ă 1âm area in a single stratigraphic context, fragmented and disarticulated cranial and postâcranial nonâadult bones were identified that displayed periosteal new bone formation. To aid differential diagnosis, macroscopic analysis, taphonomic analysis and microâcomputed tomography (ÎŒCT) imaging were integrated. Results: This approach, when combined with osteobiographical analyses, reveals that the elements most likely derive from one individual, a young child, who presents a probable case of scurvy. The potential for micronutrient coâmorbidities are explored, but without further microscopic study it cannot be determined if this individual also experienced ironâdeficiency anaemia and/or rickets. Discussion: In the context of the Mediterranean and Europe in later prehistory, reported cases of scurvy are currently low and often reveal periods of environmental instability and resource insufficiency. Our finding of nonâadult scurvy in late 3rd millennium BC Malta contributes to a developing picture of an increasingly unstable palaeoenvironment and declining population health at this time, although it may also indicate an individual case of poor childhood health within this broader context
The use of early pottery by hunter-gatherers of the Eastern European forest-steppe
The Eastern European steppe and forest-steppe is a key region for understanding the emergence of pottery in Europe. The vast region encompasses the basins of two major waterways, the Don and the Volga rivers, and was occupied by hunter-gatherer-fisher communities attracted to highly productive forest/aquatic ecotones. The precise dates for the inception of pottery production in this region and the function of pottery is unknown, but such information is vital for charting the pan-Eurasian dispersal of pottery technology and whether there were common motivations for its adoption. To investigate, we conducted AMS dating, including a re-evaluation of legacy radiocarbon dates together with organic residue analysis and microscopy. The dating programme was able to clarify the sequence and show that hunter-gatherer pottery production was unlikely in this region before the 6th millennium BC. Regarding use, stable isotope and molecular analysis of 160 pottery samples from 35 sites across the region shows that terrestrial animal carcass fats were preferentially processed in pots at Middle Volga sites whereas aquatic resources dominate the residues in pottery from the Middle and Upper Don basin. This is supported by fragments of fish, legumes and grasses in the available charred deposits adhering to the inside of pottery from the Don basin. Since the sites from both river basins had similar environmental settings and were broadly contemporaneous, it is posited that pottery use was under strong cultural control, recognisable as separate sub-regional culinary traditions. The âaquatic hypothesisâ, previously suggested to explain the emergence of Eurasian pottery, cannot be substantiated in this context
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