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Urban growth drivers in a Europe of sticky people and implicit boundaries   总被引:2,自引:0,他引:2  
We investigate urban GDP per capita growth across the EU12 usingdata for functionally defined cities—rather than administrativeregions. We test hypotheses on the role of human capital, EUintegration and fragmentation of urban government and explorespatial dependence and mechanisms of spatial interaction. Resultsare acceptable on standard econometric tests without measuresof spatial interaction but there is spatial dependence. If variablesreflecting spatial adjustment are included, they are statisticallysignificant and eliminate spatial dependence. Not only do theresults now provide consistent estimates of parameters, butthey also support relevant theoretical insights and show nationalborders are still significant barriers to economic adjustment.People in Europe are sticky so it is unreasonable to assumespatial disparities will disappear. Our findings also implythat cities in Europe form national rather than a single continentalsystem.  相似文献   
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Der letzte Bericht des Intergovernmental Panel on Climate Change (IPCC 2007) erl?utert die weltweiten Auswirkungen des Klimawandels deutlich – allerdings aus globaler Sicht. Um zu kl?ren wie sich das regionale Klima in ?sterreich ver?ndern wird, wurde mit dem Projekt „reclip:more“ (Research for Climate Protection: Model Run Evaluation) eine erste kleinr?umige Datenbasis für Klimaschutz und Klimafolgenforschung für ?sterreich generiert. Klimaszenarien wurden mittels regionaler Klimamodelle (RCMs) für die Alpen als 10 × 10-Kilometer-Raster und mit anschlie?endem Downscaling für ?sterreich mit einer Zielaufl?sung 1 km entwickelt. Die RCMs wurden mit ERA-40 Reanalyse-Daten der Vergangenheit und Daten eines Zukunftsszenarios des globalen Klimamodells (GCM) ECHAM5 angetrieben, um retrospektive (1981 bis 1990) und künftige (2041 bis 2050) Klimadatens?tze für die Alpen zu berechnen und M?glichkeiten und Unsicherheiten der Modelle und Downscaling-Methoden für die Alpen zu evaluieren. Die nun vorliegenden Datens?tze und weitere, die im Folgeprojekt „reclip:century“ für alternative Treibhausgasszenarien bis 2100 berechnet werden, dienen dazu als Basis für Aussagen über ?kologische und sozio?konomische Entwicklungen im Hinblick auf den Klimawandel.  相似文献   
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Mexico’s Central Highlands form one of Mesoamerica’s fundamental cultural seams, a point of overlap between two traditions, one to the east and the other to the west. Although this area is usually included in the west, it can be more productively viewed as an interface, the physical space where people, goods, and ideas passed from one side to the other, and thus it holds many keys for our understanding of emerging social complexity in Mesoamerica. In reviewing the last two decades of Formative period (1500 BC–AD 100) research in this crucial territory, we focus on themes that reveal the variation and dynamism of interregional interaction, including the formation of regional traditions, exchange systems, and foreign “influence,” and others that help contextualize the events and processes of that time, like household studies and environmental degradation. We stress that this part of Mexico is undergoing relentless development so time is of the essence if we are to broaden our perspectives on social evolution in the Central Highlands. This issue cannot be resolved by rescue and salvage work because it requires long-term, interdisciplinary projects to unravel multifaceted problems.  相似文献   
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This paper demonstrates the results of analyses of Cladocera, pollen, plant macrofossil, lithological and radiocarbon data recovered from a mire located in the Rawka River valley in central Poland. These studies permit to recognise the development of hydrology phases in Kopanicha mire and give insight into Holocene fluvial dynamics of the system; radiocarbon dating partly allowed da-ting of the patterns of Holocene valley floor development of the Rawka River. The Kopanicha mire was formed during the Atlantic period. At that time, an oxbow lake formed, becoming a mire during the Subboreal and possibly Subatlantic periods. The high sensitivity of the oxbow lakes, fens, fauna, and flora remains to climate variations - especially to changes in water level connected with the ag-gradation-erosion cycle of rivers - allows the reconstruction of the palaeoecological changes that oc-curred in the mire. The frequency and timing of hydroclimatic oscillations at Kopanicha show strong similarities to records from other sites in Poland. Changes in Cladocera frequency and plant assem-blages were mostly influenced by the Rawka River which controlled the hydrological regime of the mire. The main factors controlling the presence of Cladocera taxa were the water level and the pres-ence of favourable conditions in the mire (e.g. pH, vegetation). Most of the changes occurred in re-sponse to climate changes, but some of them were connected with local factors.  相似文献   
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The mastication of tough and hard foods combined with the extensive use of teeth as tools, have been considered possible antemortem causes in determining enamel microfractures of the tooth crown. This phenomenon, known as dental chipping, has been found in different fossil hominins and in several pre-historic and historic human populations who adopted different subsistence strategies. However, little is understood of the mechanism, function and the formation of dental chipping.  相似文献   
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