Stable oxygen (δO) and hydrogen (δD) isotopes in ovicaprid dentinal collagen record seasonal variation

Understanding paleoenvironmental conditions, including the frequency and amplitude of seasonal variation, is crucial to understanding a wide array of human behaviors in prehistory. In vertebrate calcified tissue, inorganic oxygen isotopes derived from apatite have been widely used as a proxy for paleoenvironment and seasonality in the archaeological record. However, organic sources of δ¹⁸O and δD in mineralized tissue have remained largely unexplored. Here we measure the oxygen (δ¹⁸O) and hydrogen (δD) composition of dentin collagen sequentially sampled from the lower cheek teeth of four modern ovicaprids from the Baga Gazar'in Chuluu (BGC) region of the Gobi Desert of Mongolia. A significant correlation between trends in hydrogen and oxygen isotope values within individual teeth was identified. The amplitude of isotopic variation observed in sampled tooth dentin is similar to the yearly range of hydrogen and oxygen isotopic variation observed in meteoric precipitation for the region. These data indicate that dentin collagen δ¹⁸O and δD isotopic values reflect seasonal variation in the organic oxygen and hydrogen isotopic composition of diet and ingested water. We argue that paired measurements of dentin collagen δ¹⁸O and δD appear to be reliable seasonal climatic indicators.     

An Exploratory Geophysical Survey at the Pyramid Complex of Senwosret III at Dahshur, Egypt, in Search of Boats

A geophysical survey at the pyramid complex of Senwosret III at Dahshur sought to determine the suitability of magnetometry and electromagnetic induction (EMI, or conductivity) for mapping the area where several ancient boat-burials were found in the 1890s. At least one boat reported at the time of excavation remains unaccounted for. Tests demonstrated that magnetometry does detect subsurface structures of stone, fired brick, and unfired brick under current site conditions. Data indicated areas of geological activity as well as unexcavated archaeological remains, though no definitive traces of boat burials. No excavation was undertaken but another survey season is planned.
© 2009 The Authors     

Museum Volunteering: Heritage as ‘Serious Leisure’

The growing number of volunteers in the heritage sector indicates a desire for a leisure experience by pursuing a subject interest with like‐minded people. Millar and others have suggested that volunteers are the ‘ultimate frequent visitors’, and as the day visitor market for museums and heritage attractions declines, this paper offers the repositioning of ‘heritage visiting’ from day visits to longer term connections with particular heritage attractions via volunteering. It draws on Stebbins’s concept of serious leisure as a way of reading museum volunteering as a leisure practice and argues that museum volunteering is a way of practising heritage as leisure that is ‘self‐generated’, with museum volunteers active in constructing their own identities. According to the concept of ‘serious leisure’, museum volunteers become part of a social world inhabited by those knowledgeable about heritage and history. The paper concludes by examining the adequacy of Stebbins’s P‐A‐P system for analysing the power relations between museum professionals and volunteers in the museum social world.     

Independent confirmation of a diagnostic sheep/goat peptide sequence through DNA analysis and further exploration of its taxonomic utility within the Bovidae

Buckley et al. (2010) recently identified a Type I collagen (COL1A2) peptide sequence that discriminates between sheep and goat species. The exact location of this peptide sequence on the genome was not reported. We identified the sequence's location and developed a PCR based approach that amplifies the diagnostic sequence from exon 41 of the COL1A2 gene. Using DNA analysis, we confirmed that this COL1A2 peptide discriminates between goat and sheep species reliably, but is limited as a more general phylogenetic marker.     

Maize,beans and the floral isotopic diversity of highland Oaxaca,Mexico

Oaxaca, Mexico has been inhabited by humans for over 10,000 years. From the time of earliest habitation, this environment provided a wide floral subsistence to its human inhabitants, notably documented at the cave site of Guila Naquitz. Light stable isotopes, primarily carbon and nitrogen, have been used in dietary and environmental reconstructions throughout Mexico and Central America. We report a large isotopic study of wild and market plants from Oaxaca that demonstrates 1) overlapping δ¹³C values of C4 plants, including maize, and plants that utilize the Crassulacean Acid Metabolism (CAM) pathway for biosynthesis, 2) the existence of a significant C4 grass biomass, 3) the lack of isotopic separation in the δ¹⁵N of legumes and non-leguminous plants and 4) the increase in the nitrogen isotopic composition of crop plants relative to wild plant averages. These four observations are potential complicating factors in interpretations involving the origins and spread of maize agriculture, the relative amount of maize in the diet and assessments of trophic level or meat contributions to the human diet.     

Rethinking voter identification: its rationale and impact

Voter ID is a contentious issue in electoral democracies worldwide. This article surveys arguments for and against voter ID in the Australian context, presenting data from the first election in the country to require it. The data demonstrate a differential impact on regional electorates and on electorates with concentrations of Indigenous voters. While the law in question (from the State of Queensland) was moderate in its overall impact, confusion created by it may have suppressed turnout. The law has since been repealed, but voter ID now has the support of a conservative majority on the Commonwealth Parliament’s electoral matters committee. We conclude that voter ID is not a solution to eliminating fraud, but an additional bureaucratic layer upon the ritual of casting a ballot and a hurdle with unintended consequences.     

Alkaline cooking and stable isotope tissue-diet spacing in swine: archaeological implications

In this study we examine the effects of alkaline cooking on carbon and oxygen stable isotopic ratios of mineralized tissues from nine pigs raised on monotonous mixed C3/C4 vegetarian diets. Two sources of collagen (humerus and mandible) and two sources of apatite (humerus and enamel) were analyzed. Within each diet group, humerus and mandible collagens were found to record equivalent δ¹³C and δ¹⁸O ratios; however, enamel apatite was found to be enriched over bone apatite by 2.3‰ in carbon and 1.7‰ in oxygen. Alkaline cooking was found to slightly, but significantly increase the Δ¹³C_{collagen-diet} and Δ¹⁸O_{collagen-diet} of bone collagen. A similar trend towards enrichment was observed in bone and enamel Δ¹³C_apatite-diet and Δ¹⁸O _apatite-diet, but the differences were not significant. Observed isotopic shifts were consistent with increased nutrient utilization of the alkaline-cooked maize as compared to raw maize. In addition, a reexamination of the relationship between diet and tissue carbon isotopic values suggests that species and alimentary type should be considered when interpreting ancient diets.     

Acheulean variability and hominin dispersals: a model-bound approach

Understanding the pattern of hominin dispersal is a fundamental component of Palaeolithic archaeology and palaeoanthropology. A widely held assumption is that bifacial handaxe (i.e. Acheulean or ‘Mode 2’) technologies evolved in Africa and dispersed into northern and western Eurasia via subsequent hominin migrations. To date, however, few formal tests of this hypothesis have been presented. Here, we use a combination of morphometrics, cultural transmission theory, and a dispersal model drawn from population genetics in order to test this hypothesis. The iterative founder effect (repeated bottlenecking) model is assumed to be supported if a significant inverse relationship is found between geographic distance from source along an estimated dispersal route and within-assemblage variance. The results of our analyses support the hypothesis that Acheulean technologies evolved in Africa and dispersed with migrating hominin populations into northern and western Eurasia under the assumptions of this iterative founder effect model. Based on our results we suggest that the occurrence of certain Mode 1 technologies such as those east of the Movius Line, and some assemblages assigned to the Clactonian of Britain, plausibly represent instances where effective population sizes in colonising populations dropped below levels where Mode 2 technologies could be maintained.     

Policy Subsystems and Regimes: Organized Interests and Climate Change Policy

This research is an examination of the role of organized interests in international climate change policy formation. Systematic survey results are used to demonstrate that organized interests actually engage in the same activities in both the international and domestic arenas. This research demonstrates that the climate change negotiations can be characterized as both a policy subsystem and an international regime. It is further argued that these two concepts are in fact highly analogous, thereby facilitating new cross-discipline research opportunities. The research is based on a web survey of organized interests accredited by the United Nations Framework Convention on Climate Change (UNFCCC), and on interviews and field research at the 8th Conference of the Parties of the UNFCCC in New Delhi, India.