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81.
Historical records indicate that the fertile soils of the western and central Wimmera Plains of Victoria, Australia formerly supported grassy woodlands on rises and flats, and grasslands on shallow depressions and clay plains. Soil type and micro-relief appear to have been the major factors that determined the distribution of these communities. Burning of the woodlands by Aborigines may have contributed to their open grassy nature. The few ungrazed remnants of Buloke (Allocasuarina luehmannii) woodland support a suite of species that are absent from or uncommon in other Buloke woodland remnants in the region. This work demonstrates that in districts where little intact native vegetation remains, investigation of the distribution and floristic composition of the pre-settlement vegetation can provide useful information for the maintenance and restoration of remnant vegetation. 相似文献
82.
Mark Billinge 《Journal of Historical Geography》1996,22(4):443-459
The institution of more regulated and spatially distinctive work practices from the early-eighteenth century onwards, together with the later Victorian penchant for classification, “cost-benefit analysis” and social theorizing drew increasing attention to the nature and use of leisure time amongst the ordinary mass of people. Mid-nineteenth century theorems began to advocate causal connections between the perceived inactivity of most leisure forms and the moral decline of the working class, and adherents to such theorems sought thereafter to institute new and improving means of recreation, or more extremely, re-Creation as a cure for the Nation's ills. Drawing further strength from constructed contrasts between the precepts of an earlier aristocratic and leisured eighteenth century, the Victorian “recreationists” sought both temporal means (based upon the use of Sunday particularly) and spatial strategies (from the design of the home, through to the set-aside space of the seaside resort) to instil discipline into leisure and to marginalize certain forms of unacceptable behaviour. 相似文献
83.
84.
We develop a new conceptual approach to locating inspection stations for hazardous vehicles, prevention, and compare it to the previous, punitive, philosophy of the flow-capturing location model. We implement this preventive protection philosophy with a new mixed integer program that maximizes hazard avoidance by locating a number of inspection stations to detect and remove hazardous vehicles as early in their trips as possible. We test the model's performance and analyze the spatial characteristics of solutions simulating several potential applications. Our computations demonstrate that a relaxed integer-linear program is overly demanding computationally and that a simple greedy heuristic lacks robustness. We suggest further approaches to developing more powerful and efficient solution methods. 相似文献
85.
86.
H. MOMMSEN TH. BEIER H. DITTMANN D. HEIMERMANN A. HEIN A. ROSENBERG M. BOGHARDT E.-M. HANEBUTT-BENZ H. HALBEY 《Archaeometry》1996,38(2):347-357
Non-destructive X-ray fluorescence analyses induced by white synchrotron radiation (SYXRF) have been performed on a page of the Gutenberg Bible and 21 other different single leaves printed in the years 1470 to 1500. Absolute elemental areal densities for the papers and the inks are reported. The known high Cu and Pb content in Gutenberg's ink is confirmed. The elemental compositions of the other inks, if measurable by XRF at all, are in general very low, governed only by a few additional elements and found to be not distinctive for a known printer. This will render an identification of the printer or printing offices by ink composition analysis in the period after 1470 difficult. 相似文献
87.
Ralph E. J. Boerner Michael N. DeMers John W. Simpson Francisco J. Artigas Alejandra Silva Leslie A. Berns 《Geographical analysis》1996,28(1):56-66
This study examined landcover change during 1940–1988 in two contiguous landscapes of approximately 12,400 hectares in central Ohio, USA: an inertial till plain area and a more dynamic moraine area. Agriculture dominated both landscapes throughout, however, the cover of natural vegetation and urban-suburban development increased over time on the moraine while natural vegetation decreased and agriculture increased on the till plain. Markov process models for landcover change were constructed for three 14–17-year time intervals and for the entire forty-eight-year study period. Probabilities of self-replacement for agricultural lands (0.91–0.97) were higher and those for forests (0.54–0.65) lower than those reported for other landscapes. Predictions of landcover percentages for fifty years in the future were made using Markov process models derived from actual cover changes in 1940–1957, 1971–1988, and 1940–1988. All three models produced similar predictions for the inertial till plain area. In contrast, the three models' predictions differed considerably for the moraine area. Only the 1971–1988 transition matrix was sensitive to increases in urbanization and reforestation which began on the moraine in the 1970s. These results indicate that reliance on lengthy study intervals and net rates of change can obscure spatial and temporal patterns of landcover change that are caused by natural and socioeconomic factors operating on shorter time scales. 相似文献
88.
Classifying coins found during excavation is a challenging task for the archaeologist. This paper describes a multimedia system designed to assist the archaeologist by enabling him either to classify coins based on a pre-existing catalogue or to draw up his own catalogue for specific purposes. The system can also be used to train novices in the field: following an initial screening, the archaeologist only has to examine coins specifically requiring his expertise. A case study uses coins minted in Salerno 800–1200 AD, but the system has been designed to classify any set of coins by simply changing the underlying knowledge base. Very little training is required to operate the user-friendly system, which runs on multimedia PCs, as it is written using the C++ language and makes full use of the advanced features of Windows 3.11. 相似文献
89.
We review evidence from human biology—paleopathological and isotopic paleodietary studies on ancient Maya skeletons—to assess the validity of ecological models of the Classic Maya collapse, in which elevated disease and deteriorating diet are commonly assumed. To be upheld, the health arguments of ecological models require that the Maya disease burden (1) was greater than that for many other societies and (2) increased over the span of occupation. The dietary argument requires (1) consistent change in diet from Preclassic and Early Classic Periods to the Terminal Classic and (2) increasing social divergence in diet. A correlation between diet and disease is necessary to link these arguments. Neither pathology nor isotopic data consistently support these criteria. Instead, it appears that local environmental and political factors created diversity in both disease burden and diet. In view of the human biological data, we are skeptical of ecological models as generalized explanations for the abandonment of Classic Maya sites in the southern lowlands. 相似文献
90.
Stenager E 《Journal of the history of the neurosciences》1996,5(2):197-199
Multiple sclerosis (MS) was first presented in a clinical setting in 1838. In this paper the presentation and treatment of a transient hemiparesis in a drummer in 1789 is discussed. This may have been an early case of MS and presents evidence against the theory that MS is an infectious disease beginning in the 19th century. 相似文献