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The paper analyses with a case study the use of a widely applied normative concept of polycentricity as spatial imaginary. The case study of Helsinki City Plan and the conflict over its city-boulevard scheme draws on qualitative content analysis of planning documents and expert interviews. It demonstrates the instrumental role of multiple interpretations of polycentricity in tension-ridden metropolitan and city-regional spatial planning. The conflict reveals how the conceptual ambiguity of polycentricity and the institutional vagueness of city-regional planning have together enabled advancing contradictory political aims under their guise. In conclusion, the paper emphasizes the persuasive performativity and fluidity of polycentricity as a spatial imaginary in multi-scalar planning settings.  相似文献   
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This paper analyzes the influence of transportation infrastructure, and in particular of the Regional Express Rail (RER), on employment and population growth in the Paris metropolitan area between 1968 and 2010. In order to make proper causal inference, we rely on historical instruments and control for all other transportation modes that could be complement or substitute to the RER. Our results show that proximity to an RER station increases employment and population density and, in particular, employment and population growth. The latter effects are higher in municipalities located near RER stations and close to employment (sub)centers. They are also found to be particularly strong for jobs in the service sector, for factory workers, and for highly educated population. We find no impact of the RER expansion on employment growth during the first part of the period, while the effect on population growth appears earlier but declines over time.  相似文献   
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During the Neolithic period, the Chengdu Plain was a key region where two important crops, rice and millet, were cultivated together. Millet was probably introduced from north-western China c.3500–3300 cal. bce , and rice came from the Middle Yangtze River c.2600 cal. bce . In this study, human and faunal remains, as well as charred crop grains, were collected from the Yingpanshan (3300–2600 cal. bce ) and Gaoshan (2500–2000 cal. bce ) sites where the dominant crop was millet and rice, respectively. Carbon and nitrogen isotope analyses were conducted on human bones and the ecofact samples in order to reconstruct the subsistence at the sites. The results indicate that the diets of two individuals recovered from the Yingpanshan site consisted of both C3- and C4-based foods, predominantly the former. By contrast, Yingpanshan pigs consumed a large quantity of C4 fodder. This result, combined with the ecofact evidence, suggests that millet was the main crop at the Yingpanshan site. It also highlights the fact that the two Yingpanshan individuals might be non-locals and/or belonged to later periods. On the other hand, the diet of the Gaoshan community was dominated by C3-based foods. When considering the archaeobotanical evidence at Baodun, a site contemporaneous with and near to the Gaoshan site, it can be stated that rice was an important food resource for the Gaoshan community. This study also suggests how crops were managed at the two sites. The Yingpanshan people might have used manure for growing millet. Both manuring and irrigation might have also been practised by Gaoshan's rice farmers. However, more studies are required to understand the extent of manuring and irrigation in their agricultural economies.  相似文献   
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Nearly 40% of agricultural workers in the United States earn an hourly wage that is within 10% of the prevailing state-level minimum wage. We evaluate the impact of the minimum wage on farm employment using county-level data from the United States Census of Agriculture. We employ long-differences specifications and find evidence of a dynamic, negative effect of the minimum wage on seasonal agricultural employment, but no effect on year-round agricultural employment. We estimate a long-run elasticity of total agricultural employment with respect to the minimum wage of about −0.40, which is both statistically and economically significant. Employers’ total expenditures on hired agricultural workers are not affected by the minimum wage. Finally, our analysis suggests that increases in minimum wages may lead to higher capital investment as well as the consolidation of farming operations in the agricultural sector.  相似文献   
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ABSTRACT

The employment of timber pegs in timber structure joints is a widespread technology in the field of timber frame building in the United States, where the Timber Frame Engineering Council has published a special Standard to supplement the National Design Specification for Wood Construction. The authors have been studying the possibility of supplementing the Eurocode 5 design formulas, thought for timber joints with metal connectors, with specifications needed for a reliable design when employing timber pegs. The field of application envisaged is that of restoring timber structures and results obtained until now are quite encouraging. In this step of the research, more attention has been paid to deformation process: fir and chestnut samples have been tested to determine their dowel-bearing behavior with steel and ash timber peg while double-shear plane joints made of the same wood species, and fastened with steel as well as timber pegs, have been analyzed.  相似文献   
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William Scott Owen figured prominently in Montgomeryshire history by being deeply involved with the lives of working people and active in local politics. He was an incomer from the south of England and a stalwart of the Anglican faith and the Tory party. He spent the whole of his working life in Montgomeryshire and came to be deeply respected in a part of Britain noted for its Nonconformity and Liberalism. Scott Owen was agent on the Gregynog Estate, which lies in the south east of the county, much of it now belonging to the University of Wales. This study of his life provides a vivid picture of the county in the late Victorian and Edwardian period and discusses why he became so well regarded.  相似文献   
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Traditional agricultural systems have been a fundamental research focus of Pacific archaeologists for decades. In many island groups, it has been demonstrated that whole landscapes have been transformed to facilitate increased agricultural production. High‐resolution digital elevation models (DEM) derived from recent LiDAR survey data from Efate, Central Vanuatu, have now revealed that much of that island was completely modified by human activity prior to European contact. There are a range of substantial and more minor linear mound and circular features associated with agricultural development and innovation, of which researchers and contemporary populations are largely unaware. Detailed analysis of the features across one alluvial plain provides some quantification of the scale of landscape modification. These new data radically change perceptions of the Efate landscape and contribute to a range of debates including traditional Pacific Island food production, its surplus and sustainability, sociopolitical development, environmental change and depopulation.  相似文献   
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ABSTRACT

The territories of the former kingdom of Judah were only sparsely settled during the Persian period, as exemplified by the extreme rarity of domestic structures unearthed in excavations. Viewed against this background, the large number of excavated forts and isolated administrative buildings from this period is remarkable, and they apparently outnumber the period's excavated dwellings. Not only is this an extremely unlikely situation, but various lines of evidence, pertaining to specific sites as well as to the phenomenon as a whole, render the possibility that all these structures were forts or administrative buildings re-examines implausible. Consequently, this article reexamines the phenomenon within the social landscape of the region in particular, and of the Achaemenid empire in general, in an attempt to embed those unique buildings within the broader demographic and political reality of this time. Given the location of many of the sites and the finds unearthed in them, and in light of the demographic reality in the region and of the broader Achaemenid imperial policy, the article suggests that most of the so-called forts were estates, created in the process of the resettlement of this previously devastated region.  相似文献   
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