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Prenatal molecular genetic diagnosis for Noonan syndrome I is reported. Noonan syndrome was suspected because of large cystic hygroma colli, massive pleural effusion and ascites at 23 weeks of gestation and normal karyotype (46,XX). DNA was prepared from amnion cells and screened for mutations in the PTPN11 gene. In exon 8, a missense mutation (S285F) was found. Delivery was induced at 33 weeks of gestation because of silent cardiotocography (CTG). Despite immediate drainage of the hydrothorax, mechanical ventilation was insufficient and the child died 9 h after birth due to severe pulmonary hypoplasia. Pleural punctate was enriched for small lymphocytes and thus was characterized as chylus. Prenatal ultrasound findings in Noonan syndrome usually are unspecific and rarely lead to a diagnosis. However, with the combination of cystic hygroma, pleural effusion, ascites and normal karyotype Noonan syndrome should be considered and DNA testing for PTPN11 mutations may be appropriate. Malformations of lymphatic vessels and/or chylothorax in Noonan syndrome seem to be more frequent than usually anticipated. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   
915.
Irrigated agriculture has resulted in substantial changes in water flows to the lower reaches of the River Murray. These changes have led to large-scale occurrences of dieback inEucalyptus largiflorens (black box) woodlands as well as increased inputs of salt to the river. Management options to address problems of this scale call for the use of spatial data sets via geographic information systems (GIS). A GIS exists for one floodplain of the River Murray at Chowilla, and a simple model predicted six health classes ofEucalyptus largiflorens based on groundwater salinity, flooding frequency, and groundwater depth.To determine the usefulness of the model for vegetation management, the quality of both the model and the GIS data sets were tested. Success of the testing procedure was judged by the degree of spatial matching between the model's predictions of health and that assessed from aerial photographs and by field truthing. Analyses at 80 sites showed that tree health was significantly greater where groundwater salinity was less than 40 dS/m or flooding occurred more frequently than 1 in 10 years or depth to groundwater exceeded 4 m. Testing of the GIS data sets found that vegetation was misclassified at 15% of sites. Association was shown between GIS-predicted values and field-truthed values of groundwater salinity but not groundwater depth. The GIS model of health is a useful starting point for future vegetation management and can be further improved by increasing the quality of the data coverages and further refining of the model to optimize parameters and thresholds.  相似文献   
916.
ABSTRACT. Most water takings in Ontario in excess of 10,000 gallons per day for purposes other than domestic, farm, or fire fighting require authorization by permit by the Ontario Ministry of the Environment. The legislation imposes control beyond that under common law, but does not remove common-law obligations. Permits may not be assigned without the Ministry's consent and do not create property rights in water. Permits to take ground-water require permittees to ensure that sufficient water is made available for the needs of prior users who suffer serious water-supply interference due to the taking, or to reduce the rate and amount of taking. Permits to take surface water require permittees to maintain sufficient downstream flow to protect downstream uses of water and natural functions of streams. Specific permit requirements for city wells in the rural Hunsburger Creek basin protect existing well supplies and require maintenance of streamflow for pond levels and fish. Tobacco irrigation in the Big Creek basin reduced streamflow significantly and requires development of more detailed water-management plans for years of extreme demand. Ontario's permit program serves to resolve water-use conflicts, furnishes information on use and provides one means for implementing management plans.  相似文献   
917.
Cleanup levels at hazardous waste sites are typically developed based at least in pan on either generic or site-specific risk assessments. Risk assessment in its purest form should be a measure of the potential for a site to cause adverse effects and therefore should be used as the basis for cleanup. However, the process of risk assessment continues to be subject to problems, primarily related to inherent uncertainties in the exposure parameters and toxicity criteria that are the building blocks of the risk assessment. Criticism of risk assessments and risk-based decisions range from comments that the process inadequately protects human health to comments that the process is overly protective, and examples of both ends of the spectrum are readily available. Site remediation professionals should be aware of the issues related to uncertainty and understand the potential problems in order to ensure appropriate and effective site cleanup. © 1999 John Wiley & Sons, Inc.  相似文献   
918.
In 1991, a fire occurred at a foundry in western Pennsylvania. The fire started in capacitors that contained polychlorinated biphenyls (PCBs) and subsequent sampling has indicated that PCBs and products of their incomplete combustion, the polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), were released as a result of the fire. This article develops and provides justification for site-specific cleanup levels for the PCBs, PCDDs, and PCDFs accidentally released into this industrial facility during the fire. Cleanup levels were calculated using standard risk assessment approaches and assumptions, and these riskbased values were compared with cleanup criteria used for other sites. Final criteria were established based on this comparison and a consideration of such site-specific factors as migration potential, industrial use patterns, and the small mass of material present.  相似文献   
919.
Agricultural management in Cades Cove, an historic district in Great Smoky Mountains National Park, has affected natural resources both within the district and in the adjoining natural areas. Aquatic impacts of haying and cattle grazing included increases in water temperatures, turbidity, nutrient loading, and bacterial counts and decreases in benthic macroinvertebrate density and fish biomass. Wildlife populations, including groundhogs, wild turkeys, and white-tailed deer, have increased in the open fields and around the periphery of the historic district. Intensive deer foraging has removed deciduous seedlings and saplings from woodlots, lowering species diversity and favoring coniferous reproduction. Cades Cove has limestone habitats unique in the park, and both deer browse and cattle grazing may have disturbed populations of rare plant species. Effects on water quality are detectable at a campground 15 stream km from the agricultural area, and the effects of deer foraging extend about 1 km beyond the open fields.Since historic landscape preservation is presently a goal of the park, managing for open vistas in Cades Cove will require some sort of continuing disturbance. Conversion of cattle pastures to hayfields would reduce aquatic impacts but the deer herd might increase as a result of reduced competition for forage. Retarding old field succession would increase populations of native plant species dependent on sunlight, but would require government-funded mowing. Other options are discussed. Completely eliminating the effects of the historic district on adjoining areas may be impossible, at least under present economic constraints.  相似文献   
920.
ABSTRACT: A method, adapted to an APL interactive terminal, is described which allows the operator to thoroughly search a large set of gaged watersheds in order to find sources of comparable hydrologic data for detailed analysis. Bases of the search - and inventory - include drainage basin size and elevation, and geographical and temporal parameters, and should enhance opportunities for more reliable use of existing data.  相似文献   
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