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101.
A detailed electron microscopy analysis of jadeitite celts from the Early Ceramic Age Golden Rock settlement on the small volcanic island of St Eustatius, Lesser Antilles, is presented in an effort to identify the source region(s) of these jadeitite axes and evaluate the extent of trade networks in the Caribbean during pre-Columbian times through which those tools (or source rocks) circulated. Habitation at the site occurred between ca. AD 230–890, and the jadeitite tools most likely date between cal. AD 600 and 825/890. We argue that in provenancing jadeitite emphasis should be placed on the identification of the entire mineral assemblage (including the accessory minerals) and textures, given the complex geological histories and processes that form this quasi-monomineralic rock. Indeed, the mineral assemblages and the characteristics of the individual minerals within the studied jadeitite samples are far from homogenous, suggesting either the source has a high degree of internal variation or there are multiple sources. We have identified three jadeitite groups among the analyzed samples on the basis of mineralogical assemblages: Group 1 consists of samples bearing phlogopite (plus phengite and epidote but without lawsonite or quartz); Group 2 contains lawsonite (plus phengite and quartz but without phlogopite and epidote); and Group 3 is defined by containing hematite. Importantly, we have not identified glaucophane in the analyzed materials. The comparison of these artifact data with those of jadeitites from the four potential known source regions of Caribbean jade, i.e., Guatemala (North and South Motagua Fault mélanges), Cuba (Sierra del Convento mélange) and Dominican Republic (Río San Juan complex) allows us to conclude that both the North and South Motagua Valley mélanges are the most likely sources for artifact groups 2 and 3, and perhaps also for group 1. This identification supports earlier hypotheses on the existence of pan-regional exchange networks, tying the northern Antilles with the Isthmo-Colombian region (Colombia, Panama and Costa Rica) during the Ceramic Age of the Caribbean.  相似文献   
102.
Since 2005 we have been utilizing accelerator mass spectrometry (AMS) 14C dating in research on calcium oxalate crusts associated with open air rock art of the Iberian Peninsula. In this paper we present two dates linked with three eye-idol pictographs at Abrigo de los Oculados (Henarejos, Cuenca, Spain). Radiocarbon ages for these motifs agree with the expected iconography-based archaeological chronology. Such oxalate dates could provide an independent basis for evaluating chronological theories for post-Palaeolithic sites, designated in the UNESCO World Heritage List as Rock Art of the Mediterranean Basin on the Iberian Peninsula.  相似文献   
103.
During the Middle Horizon (AD 650–1000), the Wari polity expanded its sphere of control in various regions of the Andes, including Nasca on the south coast of Peru. The nature of the interaction between Wari and local communities varied. This study explores the consequences of Wari contact in the Nasca region at the site of La Tiza, which includes individuals dated to the Early Intermediate, Middle Horizon, and Late Intermediate periods. Using evidence for burial ritual along with demographic, paleopathological and isotopic data, population composition, mobility, diet, and health are investigated. δ13C data indicate a relatively stable diet through time at La Tiza with evidence for continued maize consumption, and paleopathological results indicate health problems associated with this type of diet. δ18O and 87Sr/86Sr data suggest that most of the individuals buried at La Tiza were local to the area. However, two female adults from the Middle Horizon burials are characterized as nonlocal based on δ18O and 87Sr/86Sr values and several individuals overlap with the 87Sr/86Sr local range for the Wari heartland. In conjunction with the use of new tomb types during this period these results highlight the ideological and populational changes occurring with Wari contact at La Tiza.  相似文献   
104.
Abstract: The complexity of water management requires an explanatory framework that is able to capture the multidimensionality of the relations between nature and society increasingly mediated by the state. The evolution of water problems in the Baixada Fluminense, a wetland area situated to the north of Rio de Janeiro, provides a paradigmatic example of how water management becomes incorporated into the fluid politics between state, nature and society. The local experience is examined by making use of the strategic‐relational approach (after Bob Jessop) expanded to urban political ecology. The concept of “trialectics” is proposed as an ontological representation of the interconnections between the state apparatus, class‐based relations and the socionatural elements of the water cycle. The empirical results show that, in a situation of precarious water supply, regular flooding and severe river degradation, state interventions have tended to favour certain groups and areas, which only intensifies the politicisation of water management.  相似文献   
105.
The present paper reports the chemical data obtained on samples of pigmenting materials contained in 31 miniature vessels found in a burial found in Teopancazco, a multiethnic neighborhood center located in the southeastern sector of the archaeological site of Teotihuacan (Central Mexico) and the analytical protocol established for the complete characterization of these archaeological materials. For this purpose a multi-technique approach based on the combination of several non destructive and micro-destructive instrumental techniques, namely, light microscopy (LM), scanning electron microscopy-X-ray microanalysis (SEM-EDX), transmission electron microscopy (TEM), voltammetry of microparticles (VMP), X-ray microdiffraction (μXRD), X-ray diffraction (XRD), UV-Vis spectrophotometry, FTIR spectroscopy and gas chromatography-mass spectrometry (GC-MS) has been developed in an attempt to completely characterize these materials. These instrumental techniques provide reliable and complementary data including elemental and mineralogical composition, identification of functional groups as well as speciation studies of electroactive species. Among the most relevant findings, volcanic pyroclastic rocks and clayey soils, most probably, from the Teotihuacan valley as well as galena, jarosite and mica from other provenances in Mesoamerica, have been identified. Charcoal and Ocote resin have also been identified. The chemical composition of the samples is discussed with a view to the possible function as cosmetic materials and their use in funerary rites. The results have been critically compared with those others obtained in other ancient civilizations. The study carried out on the materials found in the burial 105 is especially relevant insofar it represents the first evidence, scientifically characterized, of the use of cosmetics in Mesoamerica at this early period (AD 200-550).  相似文献   
106.
107.
In this report we present and discuss an unpublished letter written by Santiago Ramón y Cajal in October 1904 in relation to his possible nomination for the Nobel Prize for Physiology and Medicine. This letter shows that Cajal was aware of his previous nominations for the Prize. He was convinced that these nominations had not been successful because neither anatomy nor histology were among the sciences included in the Nobel Statutes' definition of Physiology or Medicine. He gives a list of the merits he thought might be used for a new nomination, which included only works concluded during the previous five years.  相似文献   
108.
109.
Central areas enjoy greater efficiency in the production of goods and services than do outlying areas. Because of the inherent advantages of central areas over outlying areas, disparities among regions do not vanish over time. On the contrary, centripetal forces increase inequalities across space. The phenomena of increased globalization, trade liberalization and treaties among countries not only enable the flow of labour, products (export) and foreign direct investment but also help reduce spatial inequality between countries. These phenomena also induce greater spatial economic concentration within a country. Thus, although disparities among countries decrease, a widening gap is observed between regions within countries and within large urban areas. In the empirical part, we analyse the general patterns of spatial inequality found among 55 localities in Israel with population size over 20,000. Looking at the spatial inequality relationship, both within and between cities in Israel, we show how all economic indicators measured, including inequality, decrease with distance from the core. Localities in the periphery that experience greater equality also experience lower average income, lower education, less self-employment and more unemployment.  相似文献   
110.
The use of Nonlinear Static Procedures (NSPs) for the seismic assessment of plan irregular buildings is challenging. The most common pushover-based approaches have led to adequate results in regular buildings, and hence, there is a need to verify the validity of such methods on the assessment of irregular structures. In this article, four commonly used nonlinear static procedures (CSM, N2, MPA, ACSM) are applied on the assessment of two existing five- and eight-story plan-asymmetric buildings in Turkey. The accuracy of the different NSPs is evaluated through comparisons with the results derived from nonlinear dynamic analyses. The results are presented in terms of interstory drifts, normalized top displacements, lateral displacement profiles, chord rotations, base shear, and top displacement ratios. The performance of such procedures in evaluating the damage limitation according to the Eurocode8 is also verified. Special attention is given to the ACSM (Adaptive Capacity Spectrum Method) whose performance in 3D plan irregular buildings has recently been tested. Conclusions about the performance of each NSP are outlined at the end of the article.  相似文献   
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