Oaks,tree-rings and wooden cultural heritage: a review of the main characteristics and applications of oak dendrochronology in Europe

We overview the recent development of oak dendrochronology in Europe related to archaeology and art-history. Tree-ring series of European oaks (Quercus robur and Q. petraea) have provided a reliable framework for chronometric dating and reconstruction of past climate and environment. To date, long oak chronologies cover almost the entire Holocene, up to 8480 BC and the network over the entire area in which the two oaks grow is being improved. We present the main characteristics of oak ring series and discuss the latest methodological advances in defining the calendar year in which the tree-rings were formed and in interpreting such dating in terms of the age of a wooden object. Dendrochronology has established itself as a standard dating tool and has been applied in a wide variety of (pre-)historical studies. Archaeological wood, historical buildings, works of art (such as panel paintings and sculptures) have been successfully investigated. Recent advances in dendro-provenancing have helped to obtain more information on the timber trade in the past. Information on past forest structures, silviculture and timber use have become available through scrutinizing historical and contemporary ring-width patterns.     

Thermodynamic modeling of petroleum inclusions: the prediction of the saturation pressure of crude oils

Microthermometry and volumetric analysis are now widely used techniques in petroleum geology, which allow the reconstitution of the composition and P‐T trapping conditions of petroleum inclusions. However, these methods require efficient thermodynamic modeling tools of the PVT properties, coupled with compositional models for petroleum. Two methods presently available are reviewed here. The first one, called the α–β method, uses a compositional model describing the full spectrum (C₁–C₅₀₀) of natural hydrocarbons with two adjustable parameters α and β. The second technique is based on a so‐called fluid model, i.e., a priori knowledge of the composition and the physical properties of the C₇₊ cut of the trapped petroleum. Up to now, no critical appraisal has been undertaken for these two methods. From an extensive compilation of literature data (201 points), we here show that both techniques are able to describe the composition of crude oils and to predict satisfactorily their saturation pressures. However, the predictive capabilities of fluid models are highly dependent on the correlations used for describing heavy cuts, and we indicate those which give the best results. Finally, we emphasize the key control of the bulk methane mole fraction (x₁) on the saturation pressure: this result allows us to build simplified versions of α–β and fluid models, applicable to the majority of crude oils, and whose formulation depends advantageously on x₁ only.     

Scientific Credibility,Disagreement, and Error Costs in 17 Biotechnology Policy Subsystems

One of the original objectives of the advocacy coalition framework (ACF) was to shed light on the role of science in policymaking. The ACF depicts subsystem scientists as political actors just like any other. Unfortunately, science has never become a major theme of research within the framework and, as a consequence, its role in policymaking remains under‐theorized, leaving ample room for interpretation. This article seeks to explore the validity of three propositions about the role of science in policy. The first two are derived from the ACF: (i) the capacity of scientists to provide credible advice is affected by the harshness of the political debates dividing the policy subsystem; and (ii) agreement among scientists is just as common as among other groupings of policy actors. The third is derived from an “error costs” argument: (iii) Disagreements among scientists are even more pronounced than disagreements among other policy actors. Using the results of a survey of policy actors in 17 biotechnology subsystems, this article finds support for the first and third propositions. Indeed, scientists' participation in political divisions might even be underestimated by the ACF. The article concludes with attempts to clarify the role of scientists within the ACF, including discussions of ambiguity regarding the role of professional forums and of scientists in between‐coalition learning within policy subsystems.     

A STUDY OF OBSIDIAN SOURCE USAGE IN THE CENTRAL ANDES OF ARGENTINA AND CHILE

We present the results of XRF analysis for 428 obsidian samples from archaeological sites in the Argentinian province of Mendoza and from central Chile. The archaeological samples come from different environments and have dates that range from 9000 to 300 bp . The results indicate that all known sources were utilized; however, the beginnings and the intensities of their exploitation were variable. On the contrary, strong differences appear, especially between the Cordilleran and the non‐Cordillera sources. We suggest that this pattern is mainly related to differences in the accessibility, quality and abundance of the obsidian in the sources.     

Taking sides: cosmopolitanism,internationalism and ‘complex solidarity’ in the work of Fred Halliday

Fred Halliday's life and work were intimately associated with the theory and practice of internationalism. In his later writings, the notion of ‘complex solidarity’ emerges as a key component of Halliday's worldview. This article explores the conceptual interconnections between different historical expressions of internationalism, cosmopolitanism and solidarity. It considers the intricate relationship between these categories and their place in our understanding of international affairs, emphasizing the divergence between liberal and revolutionary conceptions of internationalism and cosmopolitanism. The article discusses diverse understandings of ‘solidarity’ in International Relations, arguing that beyond the cosmopolitan and communitarian approaches, there exist other ‘Grotian’ and ‘republican’ ideas of solidarity. Halliday drew on these to present his own defence of universal human rights and solidarity, arguably developing a distinctive brand of republican internationalism. The latter part of the article gives content to ‘complex solidarity’ by suggesting it is built on three inter‐related components: a methodological internationalism, an egalitarian reciprocity and a critique of global capitalism. Overall, these guiding features of complex solidarity deliver a unique rendition of internationalism which reflect Halliday's eclectic combination of radical liberalism with a residual historical materialism.     

Social Cooperation and Resource Management DynamicsAmong Late Hunter-Fisher-Gatherer Societies in Tierra del Fuego (South America)

This paper presents the theoretical basis and first results of an agent-based model (ABM) computer simulation that is being developed to explore cooperation in hunter–gatherer societies. Specifically, we focus here on Yamana, a hunter-fisher-gatherer society that inhabited the islands of the southernmost part of Tierra del Fuego (Argentina–Chile). Ethnographical and archaeological evidence suggests the existence of sporadic aggregation events, triggered by a public call through smoke signals of an extraordinary confluence of resources under unforeseeable circumstances in time and space (a beached whale or an exceptional accumulation of fish after a low tide, for example). During these aggregation events, the different social units involved used to develop and improve production, distribution and consumption processes in a collective way. This paper attempts to analyse the social dynamics that explain cooperative behaviour and resource-sharing during aggregation events using an agent-based model of indirect reciprocity. In brief, agents make their decisions based on the success of the public strategies of other agents. Fitness depends on the resource captured and the social capital exchanged in aggregation events, modified by the agent’s reputation. Our computational results identify the relative importance of resources with respect to social benefits and the ease in detecting—and hence punishing—a defector as key factors to promote and sustain cooperative behaviour among population.     

Footpaths Marked by Changes in Geological Clasts as Indicators of Mobility in Tenerife,Canary Islands

Studies on the mobility of past populations are useful in the interpretation of trade and lifestyle. Preservation of ancient paths is uncommon. In Tenerife, a volcanic island of the Canary Archipelago, ancient paths are still preserved, due to the dry climatic conditions and the presence of extensive lava fields in inhospitable areas of the Island. The Guanches who inhabited this island before the Spanish conquest, those surviving in the highlands after the conquest, and modern goatherders, utilised a still identifiable net of paths to access the central mountains. Clasts in the beds of these paths have suffered variable abrasion, depending on the time during which the path was used and on the number of people and/or animals that have walked on it. We estimated roundness of 1819 clasts collected at different parts of the net of paths crossing different lava fields of known antiquity. Significant differences in roundness of clasts among different parts of the paths allowed an inference about the relative importance of each of the paths constituting the net. Therefore, assessment of roundness of the clasts of the beds of paths may aid in the understanding of the migrations of people.