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Rosenberg MW 《International journal of population geography : IJPG》1998,4(3):211-226
While medical geography has grown eclectic to the point where a growing number of medical geographers prefer the terms health geographer, health geography, or the geography of health, schisms have nonetheless developed between Mayer et al. and those who have urged medical geographers to seek new epistemologies. Lost in this debate is the rapid and considerable growth of research by medical and health geographers. The author first reviews recent research on the mapping and modeling of diseases, then examines the literature on the access, delivery, and planning of health services. He then considers the debate over medical geography versus a geography of health. Opportunities are identified where medical, health, and population geographers can productively collaborate. Sharing many of the same theoretical and methodological strengths, weaknesses, and frustrations, medical, health, and population geographers need to work together toward creating inclusive geographies. 相似文献
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Previous studies have used flowmeters in environments that are within the expectations of their published ranges. Electromagnetic flowmeters have a published range from 0.1 to 79.0 m/min, and impeller flowmeters have a published range from 1.2 to 61.0 m/min. Velocity-log data collected in five long-screened production wells in the Pleasant Valley area of southern California showed that (1) electromagnetic flowmeter results were comparable within +/-2% to results obtained using an impeller flowmeter for comparable depths; (2) the measured velocities from the electromagnetic flowmeter were up to 36% greater than the published maximum range; and (3) both data sets, collected without the use of centralizers or flow diverters, produced comparable and interpretable results. Although either method is acceptable for measuring wellbore velocities and the distribution of flow, the electromagnetic flowmeter enables collection of data over a now greater range of flows. In addition, changes in fluid temperature and fluid resistivity, collected as part of the electromagnetic flowmeter log, are useful in the identification of flow and hydrogeologic interpretation. 相似文献
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Potential for satellite remote sensing of ground water 总被引：2，自引：0，他引：2
Becker MW 《Ground water》2006,44(2):306-318
Predicting hydrologic behavior at regional scales requires heterogeneous data that are often prohibitively expensive to acquire on the ground. As a result, satellite-based remote sensing has become a powerful tool for surface hydrology. Subsurface hydrology has yet to realize the benefits of remote sensing, even though surface expressions of ground water can be monitored from space. Remotely sensed indicators of ground water may provide important data where practical alternatives are not available. The potential for remote sensing of ground water is explored here in the context of active and planned satellite-based sensors. Satellite technology is reviewed with respect to its ability to measure ground water potential, storage, and fluxes. It is argued here that satellite data can be used if ancillary analysis is used to infer ground water behavior from surface expressions. Remotely sensed data are most useful where they are combined with numerical modeling, geographic information systems, and ground-based information. 相似文献
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Pterois volitans and Pterois miles, two sub-species of lionfish, have become the first non-native, invasive marine fish established along the United States Atlantic coast and Caribbean. The route and timing of the invasion is poorly understood, however historical sightings and captures have been robustly documented since their introduction. Herein we analyze these records based on spatial location, dates of arrival, and prevailing physical factors at the capture sights. Using a cellular automata model, we examine the relationship between depth, salinity, temperature, and current, finding the latter as the most influential parameter for transport of lionfish to new areas. The model output is a synthetic validated reproduction of the lionfish invasion, upon which predictive simulations in other locations can be based. This predictive model is simple, highly adaptable, relies entirely on publicly available data, and is applicable to other species. 相似文献
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Bacterial transport experiments in fractured crystalline bedrock 总被引：5，自引：0，他引：5
The efficiency of contaminant biodegradation in ground water depends, in part, on the transport properties of the degrading bacteria. Few data exist concerning the transport of bacteria in saturated bedrock, particularly at the field scale. Bacteria and microsphere tracer experiments were conducted in a fractured crystalline bedrock under forced-gradient conditions over a distance of 36 m. Bacteria isolated from the local ground water were chosen on the basis of physicochemical and physiological differences (shape, cell-wall type, motility), and were differentially stained so that their transport behavior could be compared. No two bacterial strains transported in an identical manner, and microspheres produced distinctly different breakthrough curves than bacteria. Although there was insufficient control in this field experiment to completely separate the effects of bacteria shape, reaction to Gram staining, cell size, and motility on transport efficiency, it was observed that (1) the nonmotile, mutant strain exhibited better fractional recovery than the motile parent strain; (2) Gram-negative rod-shaped bacteria exhibited higher fractional recovery relative to the Gram-positive rod-shaped strain of similar size; and (3) coccoidal (spherical-shaped) bacteria transported better than all but one strain of the rod-shaped bacteria. The field experiment must be interpreted in the context of the specific bacterial strains and ground water environment in which they were conducted, but experimental results suggest that minor differences in the physical properties of bacteria can lead to major differences in transport behavior at the field scale. 相似文献
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Kuijper MW 《Marine pollution bulletin》2003,47(1-6):265-272
UNESCO is one of the specialized agencies under the United Nations charged with the advancement and improvement of education, social and natural sciences, culture and communication. This global mandate translates into programmes in the field tailored to the member states' specific requirements that build on the full breadth of expertise available in UNESCO. Environmental awareness building is an integral component of many of UNESCO's programmes. This paper describes how UNESCO addresses the need for awareness building in a variety of settings under different programmes and sectors. A first example is taken from the work of the education sector, which aims at introducing innovative learning methods and curricula that change or cultivate the perspective of people of all ages on sustainable development. The second example is taken from the Man and Biosphere Programme. The Biosphere Reserve concept has had a long history within UNESCO and is increasingly applied to protected areas in the coastal zone. Notable examples are Ranong Biosphere Reserve in Thailand, Can Gio Biosphere Reserve in Vietnam and the Island of Palawan in the Philippines. The concept is currently experiencing a revival as more and more countries realize the importance of striking a balance between human development and strict conservation. Many people know about UNESCO through the so-called World Heritage Sites. These are sites that are recognized by the world community as particular monuments, either natural or cultural, that warrant preservation for the whole of mankind. In the Asia-Pacific region, there are quite a number of coastal and marine sites that have been designated as natural world heritage sites, e.g. Halong Bay in Vietnam, the Komodo marine national park, Indonesia, the Great Barrier Reef in Australia, East-Rennell Island in the Solomon Islands, and Tubbataha Reef in the Philippines. The need for a cross-sectoral approach is evident under the so-called Coastal Zone and Small Islands endeavour, which aims at assisting Member States towards environmentally sound, socially equitable and culturally appropriate development in coastal regions and in small islands. Four examples of current pilot projects (Surin Island, Thailand, Jakarta Bay, Indonesia, Upolo Island, Samoa and Ulugan Bay, the Philippines) are highlighted. Each setting and each audience requires a different strategy. UNESCO's strength is to learn from all these experiences and make such new insights universally available and to put novel concepts into practice. 相似文献