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A new generation of greenways has emerged in recent years, the most ambitious of which are nationwide, interconnected networks of multi-use, multi-purpose greenways and trails, clustered under a single national vision. However, because these initiatives have been the focus of so few research studies, opportunities to glean lessons from their planning and implementation have been limited. This paper contributes to addressing this knowledge gap by presenting a comparative account of two networks, the Trans Canada Trail in Canada and Sendero de Chile in Chile. Using document analysis and interviews with officials closely involved in their development, the evolution of both networks is documented over time, emphasizing similarities and differences related to their planning and implementation. Both initiatives have faced significant challenges in reaching their connection goals and have availed themselves of a diverse range of opportunities and strategies to advance their agendas. A simple model of a virtuous cycle is proposed to highlight the positive feedback—between political and public support, sustained funding, partnership development, accessibility for urban residents, and connectivity of the network—generated by sustained network expansion over time. It is hoped that the insights offered from this analysis may offer guidance to inform the development of similar scale projects elsewhere.  相似文献   
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The Rainbow Serpent: a chromatic piece. By I. Buchler and K. Maddock (eds). The Hague — Paris, Mouton, 1978. x + 227 pp.  相似文献   
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Although the progression of peace is, in all likelihood, finally imperilling the ascendancy of the thriller as the literary venue for representing social and political life in contemporary Northern Ireland, the genre continues to provide important access points for understanding the Troubles. Eoin McNamee's grim and harrowing Resurrection Man, for example, may be the only contemporary Northern Irish novel to represent the British government's mid-1970s internal security strategy known as ‘Ulsterisation’. By suggesting the various ways in which violence and subterfuge were nourished by government interests and supported by covert operatives, McNamee's novel subtly depicts a London intent on managing the conflict while insulating it from British politics and international criticism. Even as it does so, though, Resurrection Man ultimately struggles to avoid the thriller's more regressive tropes and generic conventions.  相似文献   
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Freshwater resources in past diets can lead to inaccuracies when attempts are made to ascertain their radiocarbon ages or those of the consumers. Radiocarbon reservoir effects may lead to significant age offsets when the bones or other tissues of these consumers are radiocarbon dated. A number of recent studies have investigated freshwater reservoir offsets. However no study thus far has satisfactorily obtained a ubiquitous freshwater reservoir correction due to variability in the ecosystems analysed. This study tests the possibility of predicting freshwater reservoir effects from the carbonate alkalinity of the water with measurements on modern fish bone and water samples. A predictive capability would be especially valuable in the absence of well-preserved archaeological fish bone. We surveyed samples from lakes and rivers in varying geological settings in Britain and Ireland. Modern fish bone and water samples were analysed to investigate modern radiocarbon offsets from the atmosphere. Archaeological fish bone was also analysed to examine past reservoir offsets at selected sites. Stable carbon and nitrogen isotope values were measured to aid in interpretation of any variability in the offsets. Large freshwater reservoir offsets were measured in some modern and archaeological samples (maximum offset = 1638 14C years). The freshwater reservoir offsets in the fish bone were highly correlated with alkalinity of water in modern lake sites analysed. However, a high amount of variation within and between fish species was also evident in the results, precluding the possibility of providing regional corrections for freshwater reservoir offsets from alkalinity although this still may provide a general guideline. The variability is thought to be due to differences in the diet of individual fish.  相似文献   
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Ochre is a red mineral pigment that was a key element of social and ceremonial practices among cultures of the Pacific Northwest Coast. It is recovered routinely from archaeological excavations, is visible as pigment for pictographs, and is described in the historical record as a trade item and component of ceremonial practices. Despite its ubiquity in the archaeological record, it is difficult to interpret its significance without first understanding the nature of its procurement and distribution. As a step towards identifying procurement practices, trade and resource use, it is necessary to thoroughly characterize ochre outcrops with regard to their intra‐source and regional variability. We analysed ochre from three outcrops using INAA to determine their elemental chemistry. The purpose of this study is threefold: to provide an example of the range of elemental variability within and between outcrops, to illustrate the effect of scale and geomorphological processes on elemental compositions and statistical interpretation, and to create a database of known deposits in southern British Columbia. The results demonstrate that ochre deposits may be differentiated on the basis of their chemistry, and that conservative statistical interpretation needs to be employed to assess true elemental variability within and between ochre deposits and regions.  相似文献   
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Benson, R.B.J., Fitzgerald, E.M.G., Rich, T.H. & Vickers-Rich, P., 2013. Large freshwater plesiosaurian from the Cretaceous (Aptian) of Australia. Alcheringa 37, 1–6. ISSN 0311-5518

We report a large plesiosaurian tooth from the freshwater early–middle Aptian (Early Cretaceous) Eumeralla Formation of Victoria, Australia. This, combined with records of smaller plesiosaurian teeth with an alternative morphology, provides evidence for a multitaxic freshwater plesiosaurian assemblage. Dental and body size differences suggest ecological partitioning of sympatric freshwater plesiosaurians analogous to that in modern freshwater odontocete cetaceans. The evolutionarily plastic body plan of Plesiosauria may have facilitated niche differentiation and helped them to exclude ichthyosaurs from freshwater environments during the Mesozoic. However, confirmation of this hypothesis requires the discovery of more complete remains.

Roger B.J. Benson [roger.benson@earth.ox.ac.uk], Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN, UK; Erich M.G. Fitzgerald [efitzgerald@museum.vic.gov.au], Thomas H. Rich [trich@museum.vic.gov.au], Museum Victoria, GPO Box 666, Melbourne, Victoria 3001, Australia; Thomas H. Rich and Patricia Vickers-Rich [pat.rich@monash.edu], School of Geosciences, Monash University, Clayton, Victoria 3800, Australia. Received 30.10.2012; revised 27.1.2013; accepted 31.1.2013.  相似文献   
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