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ABSTRACT. Total cleared area in a von Thünen land-use model drives an atmosphere externality which depresses agricultural productivity uniformly throughout the region. Exogenous events that encourage clearance and use of a larger cultivated area (output price or population increase) exacerbate the externality. Imposition of a simple, corrective tax on land rents does not reverse these patterns but does mitigate the increase in the externality and leaves cultivators with higher incomes than they would obtain without the tax. We examine an optimal tax on land rents, designed to maximize the social value of land rents in the region, and an output tax.  相似文献   
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In Latin America, ethnicity is equated with indigenity. It is an objective of this article to review the legacy of Anthony Smith regarding the vitality of the ethnic past and the myth of origin, as the core of his theory of nationalism based on the weight of ethnocentrism. To this end, we address two routes, the use of the ethnic past and ethnicity by nationalists and founders of the state and, how indigenous intellectuals, on the other, have found a reinvention of their identities through various myths of Amerindian origin. Ethnic myths and the use of the ethnic past have been accepted, denied or rejected by nationalists, while indigenous peoples adhere to their own myths or seek to reinvent them. Mythical information is a component of identity but also requires institutions to disseminate such information among the group.  相似文献   
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Caitlin Henry 《对极》2018,50(2):340-358
Nurses provide essential health care labor, but their work, a mix of caregiving and clinical expertise, is often undervalued and unacknowledged by health care administrators and the policies and practices that govern health care more broadly. Based on interviews with nurses working in the New York metropolitan area and through pairing feminist political economy with literature on abstraction and politics of the possible, I show that the ways in which nurses’ work is measured creates a value hierarchy of tasks. Examining various tools of measurement, I argue that methods for measuring work are rooted in an historical and continuous hierarchy of what counts as work and what has value. For nurses, these processes obscure the essential care work they perform. I argue that bringing an explicit politics of social reproduction to the politics of measuring and accounting for work makes visible necessary and often‐obscured tasks, spaces, and social relations.  相似文献   
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Poropat, S.F., Nair, J.P., Syme, C.E., Mannion, P.D., Upchurch, P., Hocknull, S.A., Cook, A.G., Tischler, T.R. &; Holland, T. XX.XXXX. 2017. Reappraisal of Austrosaurus mckillopi Longman, 1933 Longman, H.A., 1933. A new dinosaur from the Queensland Cretaceous. Memoirs of the Queensland Museum 10, 131144. [Google Scholar] from the Allaru Mudstone of Queensland, Australia’s first named Cretaceous sauropod dinosaur. Alcheringa 41, 543–580. ISSN 0311-5518

Austrosaurus mckillopi was the first Cretaceous sauropod reported from Australia, and the first Cretaceous dinosaur reported from Queensland (northeast Australia). This sauropod taxon was established on the basis of several fragmentary presacral vertebrae (QM F2316) derived from the uppermost Lower Cretaceous (upper Albian) Allaru Mudstone, at a locality situated 77 km west-northwest of Richmond, Queensland. Prior to its rediscovery in 2014, the type site was considered lost after failed attempts to relocate it in the 1970s. Excavations at the site in 2014 and 2015 led to the recovery of several partial dorsal ribs and fragments of presacral vertebrae, all of which clearly pertained to a single sauropod dinosaur. The discovery of new material of the type individual of Austrosaurus mckillopi, in tandem with a reassessment of the material collected in the 1930s, has facilitated the rearticulation of the specimen. The resultant vertebral series comprises six presacral vertebrae—the posteriormost cervical and five anteriormost dorsals—in association with five left dorsal ribs and one right one. The fragmentary nature of the type specimen has historically hindered assessments of the phylogenetic affinities of Austrosaurus, as has the fact that these evaluations were often based on a subset of the type material. The reappraisal of the type series of Austrosaurus presented herein, on the basis of both external morphology and internal morphology visualized through CT data, validates it as a diagnostic titanosauriform taxon, tentatively placed in Somphospondyli, and characterized by the possession of an accessory lateral pneumatic foramen on dorsal vertebra I (a feature that appears to be autapomorphic) and by the presence of a robust ventral mid-line ridge on the centra of dorsal vertebrae I and II. The interpretation of the anteriormost preserved vertebra in Austrosaurus as a posterior cervical has also prompted the re-evaluation of an isolated, partial, posterior cervical vertebra (QM F6142, the ‘Hughenden sauropod’) from the upper Albian Toolebuc Formation (which underlies the Allaru Mudstone). Although this vertebra preserves an apparent unique character of its own (a spinopostzygapophyseal lamina fossa), it is not able to be referred unequivocally to Austrosaurus and is retained as Titanosauriformes indet. Austrosaurus mckillopi is one of the oldest known sauropods from the Australian Cretaceous based on skeletal remains and potentially provides phylogenetic and/or palaeobiogeographic context for later taxa such as Wintonotitan wattsi, Diamantinasaurus matildae and Savannasaurus elliottorum.

Stephen F. Poropat* [; ] Department of Chemistry and Biotechnology, Swinburne University of Technology, John St, Hawthorn, Victoria 3122, Australia; Jay P. Nair [; ] School of Biological Sciences, The University of Queensland, St Lucia, Queensland 4072, Australia; Caitlin E. Syme [] School of Biological Sciences, The University of Queensland, St Lucia, Queensland 4072, Australia; Philip D. Mannion [] Department of Earth Science and Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK; Paul Upchurch [] Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK; Scott A. Hocknull [] Geosciences, Queensland Museum, 122 Gerler Rd, Hendra, Queensland 4011, Australia; Alex G. Cook [] School of Earth Sciences, The University of Queensland, St Lucia, Queensland 4072, Australia; Travis R. Tischler [] Australian Age of Dinosaurs Museum of Natural History, Lot 1 Dinosaur Drive, PO Box 408, Winton, Queensland 4735, Australia; Timothy Holland [] Kronosaurus Korner, 91 Goldring St, Richmond, Queensland 4822, Australia. *Also affiliated with: Australian Age of Dinosaurs Museum of Natural History, Lot 1 Dinosaur Drive, PO Box 408, Winton, Queensland 4735, Australia.  相似文献   
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SUMMARY: In 2014, during construction work at the ex-Civil Hospital in Gibraltar, excavations led by the Gibraltar Museum revealed a major, previously unknown burial ground containing more than 200 skeletons. We present the historical, archaeological and radiometric dating evidence from the site alongside the results of initial osteological analyses. The data indicate that the burials pertain to an earlier 16th-century Spanish hospice, and therefore stand to offer new insights into the functioning of this early modern hospital and the health and movements of people at a time of incipient globalization.  相似文献   
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