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991.
This paper investigates evidence for subsistence and settlement activities in the Levantine Middle Epipalaeolithic through the application of stable isotope analysis to human and non-human remains from the site of 'Uyun al-Hammam, northern Jordan. In general, bone from the site suffers a high degree of diagenesis and collagen could not be extracted for analysis here. Carbon and oxygen isotopic values from human tooth enamel samples were variable, but within expected values for the Middle Epipalaeolithic, whereas animal carbon and oxygen isotopic values varied widely, most likely due to hydrological and climatological factors. Carbon and isotopic values for the human samples indicated a predominantly C3 plant dietary input, while animal samples appeared to have varying amounts of C4 inputs into their diet. This is the first isotopic analysis conducted on material from the Middle Epipalaeolithic of the southern Levant and, as such, even results constrained by temporal and climatological variants within the region contribute to the overall knowledge of settlement and subsistence strategies during this cultural period.  相似文献   
992.
A landscape-scale conception of the circa 1688–1715 CE Seneca occupation at the White Springs Site (NYSM 1952; RMSC Plp-018), located in Geneva, NY, is important for understanding their built environment during a period of residential upheaval. This paper reports on approximately five hectares of high-resolution, multi-instrument archaeogeophysical surveys. These surveys allowed engagement with layered, temporal contexts and the gathering of otherwise inaccessible information. In combination with excavation, surface survey, and historic research, archaeogeophysical techniques provided expanded access to the site, a settlement size estimate of 1.42–2.75 ha, and tentative evidence for a palisade at the White Springs Site. The interplay between archaeogeophysics and other techniques was critical to this undertaking.  相似文献   
993.
Results of analyses of the photoperiod response gene (PPD-H1) and simple sequence repeats (SSRs) in modern landraces of cultivated barley were used as evidence for the mechanism of agricultural spread in Neolithic Europe. In particular, we explored the usefulness of considering adaptive genes as indicators of past selective pressures acting on crops, during their spread through Europe. In some areas, such as the Alpine region, Britain and Scandinavia, we have evidence to suggest that the adaptation of crops to certain climatic conditions may have contributed to the timing of agricultural spread. At the northern fringes of Europe, and in higher altitude locations in central Europe, the introduction of more suitably adapted cereals may have facilitated successful agriculture to trigger agricultural expansion. This research opens up the possibility of investigating other genetic adaptations to climate, which would permit a fuller evaluation of the relative contributions of climate/crop and forager/farmer interactions in the process of agricultural spread.  相似文献   
994.
The archaeological transition from Clovis to Folsom and Midland in the North American Great Plains coincides with the end of the Pleistocene and onset of the Younger Dryas. Comparisons exploring the adaptive changes that took place during this period frequently employ regional-scale approaches. The focus on regional-scale analyses largely results from the dearth of sites repeatedly visited by multiple early Paleoindian groups. However, regional-scale comparisons have the potential to overlook smaller-scale differences. The Debra L. Friedkin site, Texas offers an opportunity to study Midland, Folsom, and Clovis technology and site-use at a single site. This paper presents the context and chronology of the Midland, Folsom, and Clovis assemblages and a site-scale analysis of lithics from the Friedkin site. It is argued that point production and late-stage reduction were primary activities, and the use of bifacial cores for flake tools was important throughout these occupation periods. Site use at Friedkin differs from early Paleoindian occupation at the nearby Gault site and expands our understanding of settlement and technological organization in the region.  相似文献   
995.
Excavations at Cladh Hallan, a Bronze Age-Iron Age settlement on South Uist in the Outer Hebrides off the west coast of Scotland, revealed the skeletons of two adults, a sub-adult and a child buried beneath the foundations of three roundhouses. Osteological and isotopic evidence has shown that the male adult skeleton is a composite made up of parts of at least three different individuals. To test the hypothesis that the female skeleton was also a composite we examined ancient DNA from four of its components: the skull, mandible, right humerus and right femur. Seven polymerase chain reactions (PCRs) were attempted, these covering positions 15,996–16,420, 16–132 and 232–368 of the mitochondrial DNA hypervariable I and II regions. Three PCRs were successful for each sample and a total of 55 sequences were obtained from the cloned products. After exclusion of possible contaminating sequences, the remaining 34 were compared. It was concluded that the mandible, humerus and femur come from different individuals. Insufficient data were obtained to draw conclusions regarding the origin of the skull. The presence of two composite skeletons at Cladh Hallan indicates that the merging of identities may have been a deliberate act, perhaps designed to amalgamate different ancestries into a single lineage.  相似文献   
996.
The stability characteristics of 16th century ships are not known with certainty, but safety issues related to floatability, stability and overloading were a cause of concern at the time. The aim of the paper is to advance knowledge in this field by developing a set of loading conditions for a typical Portuguese ship of this epoch, for both the voyage from Lisbon to India and the return voyage. This allows testing the reconstruction of the presumable Nossa Senhora dos Mártires as well as to use this reconstruction to bring a better understanding of safety and loading issues on the Portuguese East India route. Given the uncertainties about the loading conditions, several hypotheses are tested, varying the amount of ballast, the degree of overloading and the distribution of weights on board, and allowing the development of a range of plausible loading arrangements. The stability of the ship is then assessed using modern tools to develop the limit KG curve for compliance with a modern stability criterion applicable to large sailing vessels. The case study ship is a plausible reconstruction based on the analysis of nautical archaeological remains, contemporary documents and the use of modern naval architecture methods.  相似文献   
997.
Research on the neurobiology and pharmacotherapy of attention-deficit/hyperactivity disorder (ADHD) has grown exponentially since 1980. A reasonable question is whether this research has improved our understanding and treatment of ADHD. This article describes relevant developments that took place roughly between 1900 and 1970. During this time, the efficacy of stimulant therapy for the disorder was established and the symptoms of ADHD were linked to many possible nervous system disorders including in the brain-stem, reticular formation, diencephalon, basal ganglia, frontal lobes, and cortex. In 1970, the catecholamine hypothesis of ADHD was proposed. It is concluded that early theories about the neurobiologic basis of ADHD anticipated core ideas of modern theory.  相似文献   
998.
ABSTRACT In research conducted some 20 years ago, we elucidated the starkly lower suburbanization propensities of black households in the Washington, D.C. metropolitan area. The paper showed that simulated closure of large socio‐economic gaps between blacks and whites did little to diminish prevailing high levels of residential segregation or otherwise enhance moves by black households to areas of educational, employment, and housing opportunity. Some two decades later and in the wake of significant urban evolution, this paper assesses anew racial variations in residential location choice. Results of the multinomial logit (MNL) analysis indicate large, persistent racial differentials in intrametropolitan residential location choice. While black location choice in 2000 was relatively more dispersed than in 1980, it remained remarkably concentrated in D.C. and Prince George's County. As in our prior analysis, results showed that large simulated gains in black economic and educational status had little effect on prevailing racial segregation. These findings underscore the ongoing, limited access of black households to schooling, employment, and homeownership opportunities available outside traditional areas of settlement. In marked contrast, the locational choices of Latino and immigrant households bore greater similarity to those of whites and were more sensitive to improvements in socio‐economic status.  相似文献   
999.
ABSTRACT Contemporary European urban planning policies aim to mix land uses in compact neighborhoods. It is presumed that mixing land uses yields socioeconomic benefits and therefore has a positive effect on housing values. In this paper, we investigate the impact of mixed land use on housing values using semiparametric estimation techniques. We demonstrate that a diverse neighborhood is positively valued by households. There are various land use types that have a positive impact on house prices, e.g., business services and leisure. Land uses that are incompatible with residential land use are, among others, manufacturing and wholesale. It appears that households are willing to pay about 2.5 percent more for a house in a mixed neighborhood. We also show that there is substantial heterogeneity in willingness to pay for mixed land use. For example, only apartment occupiers are willing to pay for an increase in diversity, whereas households living in other house types are not willing to pay for diversity.  相似文献   
1000.
ABSTRACT State per capita income differences narrowed considerably between 1939 and 1976. However, this convergence has been incomplete. We examined the sources of relative per capita income growth using an augmented growth model and a panel of the 48 contiguous states from 1939 to 2004. We explored the effect of tax burdens, public infrastructure, size of private financial markets, rates of business failure, industry structure, climate, educational attainment, and technology production. Our results show that a state's technology and its college attainment rates are the main factors that allow some state's per capita income to remain above those of other states.  相似文献   
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