Reading between the lines: δ18O and δ13C isotopes of Unio elongatulus shell increments as proxies for local palaeoenvironments in mid-Holocene northern Syria

The much debated link between the collapse of urban centres in northern Syria and climate change at the end of third millennium bc is arguably one of the best known cases about human societies' struggle with the unpredictable nature of the Holocene. Fine-grained analyses of bioarchaeological materials offer excellent opportunities to overcome some of the difficulties encountered in such studies that tackle the effects of changing environmental and climatic conditions on human civilisations during the Holocene. This paper explains the results of a pilot study that uses archaeological freshwater clams (Unio elongatulus) from northern Syria as intermediary anthropobiogenic proxies to infer about the seasonal rhythms of local pluvial regimes and their possible fluctuations at the turn of the third millennium bc. Having secreted their CaCO₃ in chemical and periodical accordance with the ambient environment and ending up at tell sites through human activity, these bivalves are suitable vessels of information about human ecology in northern Syria at the end of third millennium bc. Marked differences were observed between the isotopic (δ¹⁸O and δ¹³C) compositions of shells from Tell Mozan, an urban site that continued to exist throughout the rapid climate event, and those from Tell Leilan, which went into hiatus at the end of third millennium bc. These results have important implications about the potentially severe effects of micro-environmental differences on distinct human communities inhabiting the same culturally unified region.     

Regional polycentricity: an indicator framework for assessing cohesion impacts of railway infrastructures

Territorial cohesion has become one of the main objectives in transport planning. This has fostered the development of assessment methodologies to quantitatively estimate the territorial impact of major transport infrastructures, which are particularly scarce at the intra-regional level. Linked to cohesion, polycentricity has been defined as the best spatial configuration to achieve balanced regions where population and opportunities are distributed among several entities linked by functional relationships. This paper aims to present a methodology to estimate these impacts based on the use of a new regional composite polycentricity indicator. The proposed indicator is tested by comparing the effects of conventional and high-speed railway (HSR) alternatives in the territorial system of a northern region of Spain. This quantitative assessment is a ranking tool for prioritizing rail network alternatives in terms of achieving the most balanced territory, which is especially relevant in countries where HSR networks follow cohesion goals. Our results show that new HSR links should only be complementary to regional railway services, and that the suppression of secondary lines should be avoided if a reduction in polarization is to be achieved.     

A ‘New’ Commonwealth for Britain? Negotiating Ghana's Pan-African and Asian Connections at the End of Empire (1951–8)

This article examines to what extent Nkrumah's Pan-African ambitions and Asian connections altered the meaning of the ‘new’ Commonwealth for British policy-makers. It discusses India's influence on British political options in the Gold Coast during the negotiations for independence and Commonwealth membership and assesses the impact of Ghana's Pan-Africanism on two major facets of Commonwealth politics: Britain's ability to balance its relations with the Commonwealth and France, the other main European actor in Africa; and Britain's capacity to maintain the idea of a common heritage, which Pan-African projects like the Ghana–Guinea Union threatened to disrupt.     

The Structure and Chemical Composition of Wall Paintings From Islamic and Christian Times in the Seville Alcazar

Wall paintings from the Islamic epoch (10th to 12th centuries) and the Christian monarchy (14th to 16th centuries) have been recovered in discarded materials and on walls after reconstruction works in the Seville Alcazar. These paintings have spent centuries underground or under a plaster coat. Portable X‐ray fluorescence (XRF) and combined XRF/X‐ray diffraction (XRD) were employed in situ, as well as scanning electron microscopy (SEM–EDX), grazing angle incidence XRD and micro‐Raman spectroscopy, on cross‐section samples to fully characterize the materials in the wall paintings. Using these methods, the fresco technique was demonstrated, and many kinds of pigments were identified in accordance with the various periods of the history of the Alcazar, thus assessing the authenticity of all the wall paintings studied here.     

First Investigations of In Situ Electrical Properties of Limestone Blocks of Ancient Monuments

In situ rapid electrostatic investigations on calcareous stones of monuments provide information that strongly correlates with the geological characteristics of the stone and proves to be efficient for provenance identification and successive restoration. With a portable device, it is now possible to scan several thousand blocks on a face of a monument in a few hours. The evolution of the religious building construction practices between the 13th and the 17th centuries is studied. From the petrophysics point of view, the results clearly indicate a marked linear correlation between electrical conductivity and dielectric permittivity. This fact, which agrees with Maxwell–Wagner polarization modelling, confirms the part played by the clay content in the electric properties of the dry carbonate rocks constituting the monument stones. A first test using X‐ray scattering analysis shows the part played by the relative content of illite, which is correlated with a decrease of the resistivity.     

De la controverse aux règles de la méthode de discussion : La métamorphose Pascalienne de la dispute sur le vide

Pascal’s Expériences nouvelles touchant le vide (1647) outlines a physical demonstration that aims to put to an end controversies between plenists and vacuists. The traditional form of the dispute with which Pascal wanted to break, however, finds itself reactivated by Étienne Noël, who takes up again the plenist objections which the Expériences nouvelles only consider as possible the better to refute them. Pascal’s letters Au très révérend père Noël and À Monsieur Le Pailleur on the contrary permit one to define a field of disputation different from the one which Noël perpetuates. Pascal subordinates the dispute to the recognition of common epistemological principles: the antithetical discussion about the vacuum should be governed by methodological criteria accepted by all. In contrast with the model of the learned dispute, Pascal thus defines a radically new model: the scientific dispute.     

Parental Migration,Intergenerational Obligations and the Paradox for Left-Behind Boys in Rural China

Drawing on in-depth interviews with caregivers of left-behind children (LBC) in rural China, this article seeks to explore their understanding of migration motives and the social process of taking on care-giving roles for LBC. The authors argue that there are underlying socio-cultural explanations pertaining to economic motives for migration; such as, making contributions to social events (weddings and funerals) in village life, and fulfilling social obligations for left-behind sons’ futures. Parents migrate to save for sons’, but not daughters’, adult lives. Grandparents, particularly on the paternal side, are expected to fulfil social obligations to care for left-behind grandchildren, even without immediate financial returns. These suggest that left-behind boys, and in particular boys cared for by paternal grandparents, may be at greater risk than other LBC, as they may receive even fewer resources in the form of remittances from migrant parents in their early childhood.