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91.
92.
Economic geography has undergone a number of paradigm shifts since the Von Thunen model was at the peak of its popularity in the 1960s and 1970s. This study examines the cost of moving wheat from farm to ship in South Australia and constructs a transport-cost surface for the season 1991/92. Transport costs still exert a very important influence on farm returns and land values. Governments and other authorities, when making decisions in the name of rationalisation, or microeconomic reform, should examine very carefully the spatial consequences of their actions. In the short-run at least, the farmer's world is very much a normative and partial equilibrium one. At least in respect of a significant Australian agricultural enterprise, normative and partial equilibrium models should not be seen as obsolete.  相似文献   
93.
The issue of fairness often is central within environmental policy debates. The recent proliferation of state and local comparative risk projects for informing the selection of environmental policy priorities offers an appropriate setting to explore the issue of procedural fairness in risk-based decisionmaking. This paper describes and evaluates the process by which one of the initial state comparative risk projects, Washington's “Environment 2010,” attempted to include a broader range of participants in identifying, assessing, and generating preferred management strategies for a wide range of environmental hazards. The Washington case study suggests that comparative risk projects can be fairer procedurally, but that significant barriers remain. Noting that greater procedural fairness does not necessarily produce greater substantive fairness, the paper concludes that more attention needs to be directed at the process by which comparative risk projects translate their consensus upon risk priorities into subsequent actions.  相似文献   
94.
Fifty-three copper-based metal fragments, recovered from the Robitaille site in southcentral Ontario, were analysed by neutron activation to establish their chemical make-up and to sort them by their trace elemental chemistries. Three different European copper samples, one brassy copper and 48 brass samples with five different chemistries were found. As few as eight trading actions may account for all of the recovered European metal fragments.  相似文献   
95.
From 1865 to about 1910 studies of the chemistry of the brain were afflicted by the hypothesis that cerebral lipid matter consisted of a giant molecule from which all the simpler lipids were derived as breakdown products. In successive periods the main proponents of this 'protagon' theory were Oscar Liebreich, Arthur Gamgee and William Cramer. The theory was disproved by the careful and detailed studies of JLW Thudichum whose work on the brain was described in many papers, government reports, and two outstanding monographs. The controversy involved rough moments, generated by both sides, but by 1910, a few years after his death, Thudichum was fully vindicated in his opposition to the protagon concept and his classification of brain lipids became the accepted standard for biochemistry as a whole.  相似文献   
96.
ABSTRACT. Johansen's (1988) multivariate test for cointegration is first applied to four models involving quarterly state data and five variables, along with a national model based on Friedman and Kuttner's (1992) model of money demand, which uses three variables. Each regional model consists of frequently used national and state series, for which theory suggests the possible cointegration of several series pairs. Beginning with all five series, however, one state model is found to be cointegrated over each of 20 successive estimation intervals. The money demand model and one state model are not cointegrated over the same intervals. In the cointegrated case, five-year experimental forecasts show that error correction mechanism (ECM) and Bayesian ECM models outperform all other approaches. More importantly, forecasting performance improves further by respecifying the ECM model based on three cointegrated series pairs rather than the five-component cointegrating vector. For the two noncointegrated systems, the first-difference model suggested by the cointegration/ error correction literature is far superior to VAR in levels over both shortand long-term horizons.  相似文献   
97.
98.
The Pacific Coast of North America was occupied by many distinctive groups of coastal hunter-gatherers at the times of early contacts with Europeans. Despite significant cultural diversity, Pacific Coast peoples shared lifeways oriented toward generally similar marine, nearshore, littoral, and estuarine habitats. In this paper, we examine some major issues that guide much of the archaeology done along the Pacific Coast, then discuss some of the theoretical and methodological problems that limit the efficacy of archaeological reconstructions. Most archaeological research conducted on North America's Pacific Coast has been oriented toward the search for the origins and development of a variety of cultural patterns. A comparative review of California and Northwest Coast sequences provides interesting parallels and discrepancies in the approaches taken in studying some of the major issues in Pacific Coast prehistory.  相似文献   
99.
Significant advances in our understanding of ancient agricultural practices in the Americas have been made in recent years. This review of the literature focuses on studies published between 1987 and early 1994. Issues pertaining to the transition from foraging to farming include the habitability of the American tropics prior to the development of agriculture, theories on plant domestication and the origins of agriculture, regional syntheses of agricultural development, and the origin, evolution, and dissemination of domesticates in the Americas. Other topics reviewed include new techniques that have recently been applied to the study of prehistoric agriculture in the Americas, various approaches to the study of agricultural change, and ways in which research on ancient agricultural practices is being applied in modern experimental agriculture and rural development projects.  相似文献   
100.
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