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Georgia Tsartsidou Simcha Lev-Yadun Rosa-Maria Albert Arlene Miller-Rosen Nikos Efstratiou Steve Weiner 《Journal of archaeological science》2007
The phytolith record from archaeological strata is a powerful tool for reconstructing aspects of past human behaviour and ecology. Considerable insights into the problems and potentials of this record can be obtained by studying phytoliths in modern plants. We prepared a phytolith reference collection of modern plants mostly from northern Greece that includes quantitative information on phytolith concentrations (number of phytoliths per gram dry organic material) and morphological assemblages. Here we analyse this reference collection with the aim of evaluating the strengths and weaknesses of the archaeological phytolith record. The reference collection comprises 62 different plant taxa. Of them, 28 are trees, 1 conifer, 10 shrubs and 1 herb, 3 domesticated annual legumes and 19 monocotyledons. We demonstrate quantitatively the extent to which woody species, legumes and fruits of dicots contribute only small amounts of phytoliths to the sediments per unit tissue dry weight, while leaves of trees and shrubs produce significant amounts of phytoliths and grasses are prolific phytolith producers. We compare the data of this reference collection with a similar reference collection from another Mediterranean ecosystem (Israel). The comparison indicates that some aspects of phytolith production are probably genetically controlled, whereas others are environmentally controlled. We note that despite the fact that woody species produce few phytoliths per gram of tissue, their record can be most informative when taking into account other properties of the sediments. We also note that jigsaw puzzle-shaped phytoliths normally form in plants that grow in humid conditions, but may form in arid environments when the plants are irrigated. This study clearly shows the extent to which some plants can be under-represented and others over-represented in the phytolith record. Knowing the extent of this bias can greatly improve our interpretation of the phytolith record. 相似文献
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Steve Bradley Giuseppe Migali Maria Navarro Paniagua 《Journal of regional science》2020,60(5):1074-1107
We investigate the “determinants” of spatial variations in youth unemployment and NEET rates, and the presence of spatial clusters, for Italy, Spain and the UK. We aggregate Labour Force Survey data for the period 1993–2018 to a “regional” level. We find that youths are sensitive to aggregate labor market conditions and a discouraged worker effect. In the UK and Spain, temporary jobs are more likely to be preferred to part-time jobs, whereas in Italy the opposite occurs. There is evidence of spatial clustering of youth unemployment and NEET rates. We discuss the implications for place-based regional and labor market policies. 相似文献
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Steve Marsh 《Iranian studies》2009,42(2):213-229
2009 is the thirtieth anniversary of the Iranian Revolution. In 2006 the Bush administration ranked Iran as posing arguably the greatest single threat to America. And throughout 2008 that administration insisted all options were open in dealing with Iran, including preventative strikes. Yet, unlike its decisive intervention to establish Iran as a client state in the 1950s, the US has thus far been unable to force the changes it desires in and from Iran's leadership. This article argues that to help understand this situation it is important to recognize that the Iranian Revolution was and remains nurtured by a contemporaneous “silent revolution” in the international oil industry, even if the Ahmadinejad regime's economic policies especially threaten currently to squander some of the potential afforded by it. 相似文献
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Steve Weber Heather Lehman Timothy Barela Sean Hawks David Harriman 《Archaeological and Anthropological Sciences》2010,2(2):79-88
Ancient seeds from archaeological sites can provide clues that are crucial for understanding and characterizing subsistence strategies. This in turn contributes to our understanding of, and explanations for, the relationship between socioeconomic systems and organization of craft production. This article will examine the relationship between rice and millets at three prehistoric sites from a regional copper-producing center in central Thailand to provide new insights into the subsistence strategy of these communities and to better understand the relationship between these crops and their introduction and use in Southeast Asia. 相似文献
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Richard Cosgrove Judith Field Jillian Garvey Joan Brenner-Coltrain Albert Goede Bethan Charles Steve Wroe Anne Pike-Tay Rainer Grün Maxime Aubert Wendy Lees James O’Connell 《Journal of archaeological science》2010
The reasons for megafaunal extinction in Australia have been hotly debated for over 30 years without any clear resolution. The proposed causes include human overkill, climate, anthropogenic induced habitat change or a combination of these. Most protagonists of the human overkill model suggest the impact was so swift, occurring within a few thousand years of human occupation of the continent, that archaeological evidence should be rare or non-existent. In Tasmania the presence of extinct megafauna has been known since the early twentieth century (74, 85 and 86) with earlier claims of human overlap being rejected because of poor chronology and equivocal stratigraphic associations. More recent archaeological research has not identified any megafauna from the earliest, exceptionally well-preserved late Pleistocene cultural sites. In 2008 however an argument for human induced megafaunal extinctions was proposed using the direct dates from a small sample of surface bone from two Tasmanian non-human caves and a museum sediment sample from an unknown location in a cave, since destroyed by quarrying (Turney et al., 2008). Turney et al. (2008) supplemented their data with published dates from other Tasmanian caves and open sites to argue for the survival of at least seven megafauna species from the last interglacial to the subsequent glacial stage. 相似文献