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1.
In this article, prehistoric population history in eastern Fennoscandia is modelled using summed probability distributions of radiocarbon dates. In addition, radiocarbon date distribution is compared with other proxy data. Different proxies seem to produce similar distributions, which enhances the overall reliability of the pattern. The results indicate that there was a very pronounced peak in the hunter–gatherer population slightly after 4000 cal BC. This peak seems to be linked to increased environmental productivity. The subsequent population decline culminated just before the local appearance of farming economies in different sub-areas, which is an interesting result in the wider northern and central European context. Along with the adoption of agriculture, new population growth began in eastern Fennoscandia.  相似文献   

2.
东西部区域发展差异实证分析   总被引:1,自引:0,他引:1  
苏多杰 《攀登》2009,28(4):70-75
我国东西部发展差距不断扩大的问题仍未得到有效地解决,有些方面还在进一步拉大,有些问题甚至更加突出。本文从经济、社会、科技和对外开放等几个角度对此进行了分析。  相似文献   

3.
This commentary on the Feeding Teotihuacan collection of papers provides an “outsider” perspective on the contributions, by an archeologist who conducts research on agriculture and plant use by the ancient Maya.  相似文献   

4.
Charcoal recovered from different archaeological excavations carried out in the Teotihuacan Valley, México was used to evaluate whether significant changes in the use of wood took place through time (approx. 400 B.C.–A.D. 1500). Sixteen taxa of trees and shrubs characteristic of the Basin of Mexico were identified (including Pinus, Quercus, Arbutus, Cupressaceae, Alnus, Prunus, Taxodium, Salix, Baccharis and Buddleia, among others). Variations in the proportions of taxa are interpreted as a reflection of the intensity of use rather than an indicator of deforestation. The analysis of the data shows a pattern of continuity in the utilization of taxa throughout the occupation. This includes the use of different vegetative parts (trunk and branches), genera and species with different life forms (trees, shrubs, herbaceous plants) and primary (Pinus and Quercus) as well as secondary taxa (Prunus and Arbutus). We propose that the inhabitants of the Teotihuacan Valley implemented practices to manage vegetation in order to assure resource availability in the region.  相似文献   

5.
"This paper presents a two-sector dynamic model of regional population change. The model contains a migration equation, an earnings equation, and an amenity equation for each region. In the context of this model, migration is seen as a disequilibrium process through which the regional populations move towards equilibrium positions. Migration occurs when one region is perceived to be superior to the other on the basis of its earnings and amenity levels. Equilibrium is achieved when population movements between the regions eliminate any differences in their relative attractiveness. A comparative-static analysis of the model is presented to analyze the effects of policy changes and exogenous shocks on the distribution of population among the regions." The geographical focus is on the United States.  相似文献   

6.
In the present investigation, a geophysical study was carried out in the eastern flank of the Pyramid of the Sun to define potential continuations in this direction of a tunnel discovered beneath the western main entrance of this building. This man-made structure is one of the many extraction tunnels hollowed by the ancient Teotihuacans to obtain construction materials to build their city. Total field and high-resolution vertical gradient magnetic surveys were carried out. The spectral analysis of the total magnetic field enabled us to estimate the thickness of the alluvial cover over the basaltic flow as 3·3 m. It was also found that the main contribution to the observed magnetic field comes from the pyroclastic flow that covers the area of study. The horizontal gradient filter was applied to the low-pass filtered magnetic field to enhance magnetic contacts and structural boundaries. Inferred magnetic trends were related to fracture patterns within the basalts and pyroclasts, and low gradients provided an evidence of voids or tunnels. The Euler deconvolution method was applied as an attempt to confirm the above results. Using a structural index S=0, we determined the boundaries of main magnetic contacts as well as the interface between the basaltic flow and Las Varillas tunnel. Euler depths were found to range between 3 to 6 m, which represent the mean thickness of the basaltic flow.Two parallel ground probing radar (GPR) profiles were surveyed in the NW-SE direction. One passes on top of the known location of a tunnel (Las Varillas) and a second one 10 m to the north, approximately. The tunnel's roof is well outlined at depths between 3·5 and 4 m. On the other hand, little evidences of other buried tunnels or extensions of the known one were found. The second profile depicts a more complex morphology for the pyroclastic sheet. Anomalies related to basaltic flow or eruptive centres are clearly observed. Both profiles depicted the sedimentary base at 3 m, on average. A resistivity profile was undertaken along the first GPR profile. A resistivity image was obtained, that showed the vertical and lateral distribution of the true resistivity. High resistivity values were associated with the tunnel location (Las Varillas). Its geometry could also be inferred, its top is found at about 4 m and extends 20 m in the profile direction to the west. Unfortunately, the depth to its base could not be estimated, since profile length was too short. The sediment-pyroclastic flow interface could also be delimited at a depth of 3 m.Finally, a vertical magnetic field profile taken along the same surveyed line (GPR and resistivity) was inverted applying a two-dimensional algorithm. The initial model was estimated from GPR and resistivity interpretations. A simple model of Las Varillas tunnel was computed, which reasonably well satisfied geological and geophysical considerations.  相似文献   

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This study examines the diet consumed by the population at the neighborhood center of Teopancazco, Teotihuacan, in the basin of Mexico. We used stable isotope analysis of δ13C and δ15N of the dentine collagen as well as the δ13C from enamel bioapatite from teeth (M2 and M3) of 39 of excavated burials. The results show that the diet consumed by the majority of the population during childhood and adolescence had high 13C enriched values in both dietary components: δ13C enamel_bioapatite = ?2.0 ‰ ± 1.5 for the whole diet and δ13C dentine_collagen = ? 9.4 ‰ ± 2.1 for the protein component. According to the bi-variable and multivariable models, some individuals consumed higher amounts of C4/CAM resources than those specified in cluster #2 (70 % C4 diet; ≥50 % C4/CAM protein). An inter-tissue adjustment of 2.3 ‰ was used to relate the enamel bioapatite data to the bone bioapatite of the models. Average δ15Ndentine_collagen was 10.2 ‰ ± 2.8 with high variability especially for four individuals, three of which belong to special burials, suggesting different access to meat or marine products due to their social or migration status and/or to pathological conditions. The data suggest that maize was the staple crop of the population not only at Teopancazco but for Teotihuacan as a whole, in the form of tortillas, tamales, atole, and protein from maize-fed animals with the inclusion of other CAM, C4, and C3 resources probably from the bountiful ecosystem of the basin of Mexico or from the wide trade system that Teotihuacan had with Mesoamerica.  相似文献   

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10.
Mechanisms for the maintenance of Zapotec ethnicity in Tlailotlacan, an enclave of Teotihuacan, Mexico, are reconstructed using oxygen-isotope analyses of bone and enamel phosphate. The data indicate continual interaction among the enclave inhabitants, their Oaxacan homeland, and other diaspora colonies, with no dominant post-marital residence pattern. There is no apparent association between social status and place of origin, and individual agency is indicated by variable acceptance of Teotihuacan traditions. Striking patterns of movement include the sojourning of children in other regions and the relocation of breastfeeding women. These segments of the population would have played major roles in the social and political articulation of diaspora colonies. Foreign signatures in primary burials indicate that some immigrants died shortly after their arrival in Tlailotlacan. Data from secondary burials indicate the transportation of dead relatives or ancestors to Teotihuacan for burial. We conclude that the behaviour of immigrants in ancient and modern cities is analogous in many ways.  相似文献   

11.
This study characterizes the degree of calcination of lime in lime plaster samples from Teotihuacan, the capital of a regional state in prehispanic Central Mexico. Lime plaster production consists of multiple steps, from the firing of raw materials to the mixing of lime and aggregate and the final application. While previous studies have focused on the compositional variability, specifically the recipe of lime plasters and mortars, the characterization of lime itself has not been sufficiently addressed. In this study, cathodoluminescence analysis coupled with petrographic and image analyses were employed to examine the degree of calcination of lime. The results of cathodoluminescence petrography were further examined through stable carbon isotope and 14C measurements. It appeared that the results of cathodoluminescence analysis are consistent with those of other analytical methods and that there are diachronic changes in the degree of calcination of lime among lime plaster samples. This implies changes in the organization of lime production, specifically the consistency in the control of firing temperature.  相似文献   

12.
We present the chemical characteristics of samples collected from the central courtyard of Teopancazco, a neighbourhood centre in Teotihuacan (Mexico), the most important classic Mesoamerican city. The rhyolitic glass shards used as aggregates have a composition comparable to the glass material sourced from the magmatic system of Altotonga (located along the route to the Gulf Coast). People travelling from the Gulf Coast may have transported the glass shards to Teotihuacan during the Xolalpan phase (350–550 AD). However, the reasons for using glass shards as a construction material remain unknown. These new data confirm the close relationship between inhabitants of Teopancazco and the Gulf Coast already revealed by previous archaeological and archaeometric studies.  相似文献   

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14.
The directions of propagation, in the earth-ionosphere waveguide, of multi-component two-hop whistlers recorded on 10 July 1972 by four VLF goniometer receivers in eastern Canada have been determined. Using the bearings of these great circle paths, triangulation of several whistler exit-points has been accomplished. The L-values of the whistler exit-points determined by this method are systematically lower than those expected from their nose frequencies, by ~ 0.6. Various explanations are discussed for this effect. The most satisfactory is that the whistler waves leave through the side of the ducts (in which they had propagated for most of their path through the magnetosphere) at an altitude of a few thousand kilometres, and then are refracted to lower L-values before exiting from the lower ionosphere. The results are consistent with both the duct termination altitude predicted by Bernhardt and Park (1977) for the appropriate conditions and also with the observed upper cut-off frequency of the whistlers.  相似文献   

15.
Changing configurations of national elites are shaping the prospects for democracy in the countries of Central and Eastern Europe. There are three broad possibilities: (1) increasingly unchecked and violent power struggles between elites, with regimes oscillating between democratic and authoritarian forms; (2) restrained elite competitions in accordance with democratic game rules and tacit accommodations, with regimes gradually becoming stable democracies; (3) takeovers by ultra‐nationalist elites through coups or plebiscitary victories, with regimes becoming state‐corporatist in form and quasi‐fascist in operation. Crucial questions are the extent and nature of elite unity and differentiation. This article identifies elite configurations and the most likely regime outcomes in Bulgaria, the Czech Republic, Hungary, Poland, Romania, Russia, Slovakia, and Ukraine.  相似文献   

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The aim of modern innovation policies is to enhance the innovation capability of regions, their organizations and people. Regional innovation system (RIS) theory has been one of the most popular frameworks for realizing innovation policies. Yet, adopting the perspective of sustainable innovation policy where innovation is also seen as a solution to various societal and environmental problems has been slow. Social enterprises (SEs) are discussed here as a means to address those problems, particularly through collaboration between sectors and focusing on social sustainability. The aim of this paper is to identify whether and in what way SEs are communicated as an innovative solution and as a source of innovations for economic and development activities through regional strategies. The data consist of regional innovation and business strategies from all Finnish regions, analysed using qualitative content analysis. We argue that there is a need to go deeper and include effective support mechanisms for SEs in these documents. Better inclusion of SEs as part of innovation systems and communicating this through regional strategies would help to develop SEs and to have them perceived as potential innovators and active entrepreneurial actors in innovation systems contributing to economically, environmentally and socially sustainable development.  相似文献   

19.
Eastern North America in late Pleistocene times was characterized by two major environmental regions: a periglacial tundra or open spruce parkland and an extensive complex boreal/deciduous forest in the unglaciated, lower latitudes. These environments selected for different adaptive strategies on the part of human foraging groups—known archaeologically as Paleoindians. Those in the tundra and tundra-forest region were highly mobile, possibly specialized hunters, exploiting caribou; those in the forest were generalists, exploiting a variety of subsistence resources with a less mobile settlement system. There is little evidence in either area for hunting of Pleistocene megafauna. These differences in adaptive strategies are reflected in the record of sites and isolated fluted points scattered throughout the region, as well as aspects of tool technology, function, and patterns of stone use.  相似文献   

20.
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