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JOHNSON J 《California medicine》1956,85(3):147-151
The best opportunities at present for improving the results in the treatment of patients with cancer of the lung are by way of (a) utilizing the information obtained on routine x-ray examination of the chest, (b) decreasing the delay between the time of the first symptoms and the time the patient consults a physician, and (c) decreasing the delay between the time the patient first consults a physician and the time the cancer is surgically removed. The medical profession must increase its index of suspicion of cancer of the lung and persist in efforts to make a diagnosis when lung cancer is suspected. Exploratory thoracotomy should be used in suspicious cases when the diagnosis cannot be established by other methods. 相似文献
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LUCINDA JOHNSON & STUART GAGE 《The Plant journal : for cell and molecular biology》2004,37(1):113-132
1. In the mid-1970s, Hynes (1975) wrote eloquently about the complex interactions between aquatic and terrestrial systems. Central theories in stream ecology developed thereafter have dealt with the longitudinal flow of energy, materials and organisms in streams, and, with the exception of the flood pulse concept (Junk, Bayley & Sparks, 1989), have largely ignored areas outside the riparian zone. The structure of the upland and activities occurring there play a more important part than previously recognized in regulating community structure and ecosystem processes in streams.
2. These new perspectives are made possible by developments in hierarchy theory, patch dynamics, and the refinement of tools used to quantify spatial and temporal heterogeneity.
3. Geographical information systems (GIS), image processing technology and spatial statistical techniques allow quantitative assessment of lateral, longitudinal and vertical components of the landscape that interact at several spatial and temporal scales to influence streams. When GIS is used in concert with geostatistics, multivariate statistics, or landscape models, complex relationships can be elucidated and predicted.
4. To a certain extent, the tools discussed above have only automated functions that were previously performed manually. This suite of tools has improved the ability of aquatic ecologists to examine relationships and test theories over larger, more heterogeneous regions than were previously possible.
5. At the local, state and federal level, management and regulatory frameworks are currently being re-evaluated to incorporate this new perspective in resource management and policy decision making.
6. We will discuss current and future trends in technologies and tools used for aquatic ecosystem research, and the use of techniques as they are applied in these regional assessments are also discussed. 相似文献
2. These new perspectives are made possible by developments in hierarchy theory, patch dynamics, and the refinement of tools used to quantify spatial and temporal heterogeneity.
3. Geographical information systems (GIS), image processing technology and spatial statistical techniques allow quantitative assessment of lateral, longitudinal and vertical components of the landscape that interact at several spatial and temporal scales to influence streams. When GIS is used in concert with geostatistics, multivariate statistics, or landscape models, complex relationships can be elucidated and predicted.
4. To a certain extent, the tools discussed above have only automated functions that were previously performed manually. This suite of tools has improved the ability of aquatic ecologists to examine relationships and test theories over larger, more heterogeneous regions than were previously possible.
5. At the local, state and federal level, management and regulatory frameworks are currently being re-evaluated to incorporate this new perspective in resource management and policy decision making.
6. We will discuss current and future trends in technologies and tools used for aquatic ecosystem research, and the use of techniques as they are applied in these regional assessments are also discussed. 相似文献
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Data on re-mating between and within breeding seasons were collected between 1983 and 1994 as part of a long-term study of the Greater Flamingo Phoenicopterus ruber roseus in the Camargue, southern France. Flamingos have bred in the Rhône delta for centuries and since 1972 have done so annually on an artificial island in the Etang du Fangassier. A sample of chicks has been ringed each year since 1977; many of these birds were later observed back at the breeding site and were used in this study. The mate-switching rate between consecutive breeding seasons was 98.3%. This result is contrary to what has been reported from captive flocks where extensive mate fidelity occurred between consecutive breeding seasons. Mate-switching also was observed in the Camargue within breeding seasons, following breeding failure, and seems to be linked to male breeding strategy in response to the need to synchronize hatching and the limited energy supply of breeding females. The absence of a long-term pair bond in Greater Flamingos contrasts with current views on the evolution of mate fidelity in relation to longevity in birds. 相似文献