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Can age, period and cohort effects help explain support for Quebec sovereignty? Previous work on this question has focused mostly on the effects of age and cohort. We contribute to this debate by adding a period perspective. As such, our study is the first to investigate the impact of age, cohort and period effects in a single study of opinion towards sovereignty in Quebec. We take advantage of an original dataset that includes survey data collected between 1985 and 2012. We use these data to examine the impact of age, birth year and survey year on support for this constitutional option among francophone Quebeckers. Our results are in line with previous work: we show that younger Quebeckers are more likely to support sovereignty, and that some cohorts – namely, respondents born between 1945 and 1959 – are also more likely to favour this option. Perhaps more surprisingly, we find that specific events are comparatively the most important factor to explain fluctuations in Quebeckers' attitudes towards sovereignty.  相似文献   
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Remains of the 16th-century Yarmouth Roads wreck, buried in sediments, were imaged using high-resolution geophysical techniques. The remains appear as strong reflectors underlain by an acoustic blanking zone, which was used to create maps of the wreck material. Close survey line-spacing allowed the construction of contour maps and hull sections, which revealed that the bow and stern sections are tilted to port at different angles, implying that they are detached. The seismic data have enhanced our understanding of the site beyond what was known from conventional archaeological investigations and confirms that this wreck was once a large carrack.
© 2007 The Authors  相似文献   
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The presence of many phytolith-rich layers in late Bronze and Iron Age deposits at Tel Dor, Israel, are indicative of specific locations where plants were concentrated. Detailed studies of six of these phytolith-rich layers and associated sediments from Tel Dor show that the phytoliths were derived mainly from wild and domestic grasses. The most common domestic grass was the cereal Triticum aestivum (bread wheat). Three of these layers have a microlaminated microstructure, associated dung spherulites and phosphate nodules; characteristics that all point to the phytolith-rich layers having formed from dung in animal enclosures. In two of the layers, the microlaminated structure is absent while dung spherulites and phosphate nodules are present, suggesting that these too originate from dung that was not deposited in an enclosure. The sixth layer is microlaminated but does not contain spherulites. We thus cannot suggest a parsimonious explanation of its observed properties. Concentrations of burnt phytoliths are present in three locations, implying that dung was either burnt in situ or the ashes from burnt dung were redeposited. The transformation of dung accumulations into phytolith-rich layers involves a loss of organic material and hence a significant reduction in sediment volume, which is clearly apparent in the stratigraphy of some of the locations examined. The volume reduction can be observed in the macrostratigraphy and has important implications with regard to macrostratigraphic interpretation. The presence of abundant phytolith-rich layers on the tell has significant implications for the concept of ‘urbanism’ during these periods.  相似文献   
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