Possible isotopic fractionation of argon in source obsidians and archeological artifacts from Kulkuletti, Ethiopia

Despite uniform geochemistry ⁴⁰Ar/³⁹Ar ages of 0.6, 1.25, and 1.3 Ma on obsidians from a source flow (Worja) and from archeological artifacts at the sites of Kulkuletti (near Gademotta, Ethiopia) have been interpreted to suggest that they derive from different source flows of different ages. A further suggestion is that the magmatic source of the obsidian flows was chemically homogeneous between 1.3 Ma and 0.6 Ma. Chemical analysis of these obsidians indeed suggests that they derive from a single flow. Reexamination of the argon isotopic data reveals that argon isotopes may have been fractionated within the flow, so that the assumption of an atmospheric ⁴⁰Ar/³⁶Ar ratio of 295.5 is inappropriate to use for computing ages. Three groups of data are apparent, and internally all yield ages near 1.3 Ma if the intercept value for ⁴⁰Ar/³⁶Ar from an isotope correlation plot is used for computation instead of using the atmospheric ratio. The Soret thermal diffusion effect provides a possible mechanism of fractionation of argon within the obsidian flow that is of approximately the right magnitude to explain the observations by in-diffusion of already fractionated atmospheric argon.     

'Walking a Real Tight-rope of Difficulties': Sir Edward Heath and the Search for Stability in Northern Ireland, June 1970-March 1971

Since we know Sir Edward Heath was forced to impose direct ruleover Northern Ireland in March 1972, before launching his governmentinto a series of highly constructive (if unsuccessful) initiativesthat led to the Sunningdale Agreement, his policy and approachtowards the province during the first 18 months of his premiershiphas rarely been seen as anything other than a tale of miscalculation,poor judgement and political ignorance. However, with the openingup of various official papers over the past few years, it isnow possible to offer a more sympathetic assessment of Heath'searly attempts to deal with the situation in Northern Ireland.This assessment suggests that his policy, far from being barrenand directionless, was beginning to evolve in quite innovativeand radical directions as it sought to stabilize and reformNorthern Ireland, directions that, significantly, pre-figurethe various policy initiatives Heath took after 1972. Theseincluded the pursuit of active cooperation between London andDublin, and between Dublin and Belfast, major political changein Northern Ireland, with the full involvement of the minorityin the governance of the region, and a consideration of futureconstitutional relationships between London, Belfast and Dublin.     

The in situ preservation of archaeological remains: using lysimeters to assess the impacts of saturation and seasonality

Recent research has studied the effects of seasonal variability on waterlogged burial environments. In a new approach to the study of archaeological contexts, the use of controlled laboratory conditions via lysimeters has enabled new insights into the nature of short term fluctuations in saturation, and the impact that these can have on burial contexts. In addition, the protocols used have facilitated interesting insights into burial environments and the way in which fluctuations in saturation and seasonality can impact on the contained organic components within them.     

Viewing obesogenic advertising in children's neighbourhoods using Google Street View

The advertising of unhealthy food and beverages forms an important component of obesogenic environments. Such marketing to children is a key health determinant because of its impact on dietary preference and food purchasing behaviour. The location of outdoor advertising is important in exploring obesogenic environments and children's neighbourhoods. The aim of this study is to explore issues involved in the use of Google Street View to examine outdoor food and beverage advertising. The implications for using Google Street View in the context of neighbourhood built environment research and grass‐roots advocacy are discussed. The study was conducted within walkable distances from 19 primary and intermediate schools in Auckland, New Zealand, where “walkable” was defined as limited by 800 m road network boundaries, which are equivalent to school buffer boundaries. Google Street View allows for centrality of data collection, coding, and storage. However, challenges exist with the method because 727 (29.4%) of a total of 2,474 outdoor advertisements that were identified were not able to be categorised because images were unclear, not in English, blocked, or at angles where detail cannot be deciphered. Specific to outdoor advertising for food and beverages, the results presented here show that children are exposed to a significantly greater number of unhealthy advertising than other advertising, P=0.001, eta‐squared statistic (0.45) indicates a large effect size. Overall, the results show promise for the use of Google Street View in the study of obesogenic environments.     

Time-Averaging Slows Down Rates of Change in the Archaeological Record

Measuring the pace of cultural change, and understanding its determinants is a fundamental goal of anthropological research. The archaeological record is the main source of information about the pace of cultural change, but it is an imperfect one, as taphonomic loss and mixing distort rate measurements. Here, I focus on the impact of time-averaging on rate measurements. Time-averaging arises when archaeological materials associated with activities and events that took place at different points in time are mixed into the same unit, whether because of depositional processes, disturbance factors, or because archaeologists lump together archaeological contexts when creating analytical units. I use analytical models to show how time-averaging can slow down the observed rates of change under two general modes of cultural change: random drift and directional change. I test this prediction using empirical rates of change from the archaeological record of North America. I show that empirical rates of change are indeed inversely correlated with the duration of time-averaging and provide a range estimate for this correlation.     

Degrees of Engagement: Using Cultural Worldviews to Explain Variations in Public Preferences for Engagement in the Policy Process

Scholars have been studying the concept of public engagement and its role in the policy process for some time. Scholars have argued that understanding the interests and motivations of the public and engaging them in the decision‐making process can lead to better policy designs and, ultimately, better policy outcomes. However, studies of public engagement often assume that people have a desire to get involved in the policy process. This paper tests this key assumption using the case of nuclear facility siting in the United States to ask: what factors influence an individual's stated willingness to want to engage in the policy process? Using data from a national web survey fielded in 2013, we ask the public if and to what extent they would likely engage in the siting process if given the opportunity. Findings indicate that the likelihood of engagement varies rather substantially across individuals. We find that an individual's cultural belief system and existing level of political activity account for some of this variation. These findings suggest that public engagement programs may vary across groups and communities. In other words, the prospects of engagement are likely to appeal to some members of the population and not others.