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71.
An Aquifer Vulnerability Assessment of the Paluxy Aquifer, Central Texas, USA, Using GIS and a Modified DRASTIC Approach 总被引:8,自引:1,他引:8
D epth to water, net Recharge, Aquifer media, Soil media,
Topography, Impact of the vadose zone, and
Conductivity of the aquifer). Using such an approach allows one to investigate the potential for groundwater contamination
on a regional, rather than site-specific, scale. Based upon data from variables such as soil permeability, depth to water,
aquifer hydraulic conductivity, and topography, subjective numerical weightings have been assigned according to the variable's
relative importance in regional groundwater quality. The weights for each variable comprise a GIS map layer. These map layers
are combined to formulate the final groundwater pollution potential map. Using this method of investigation, the pollution
potential map for the study area classifies 47% of the area as having low pollution potential, 26% as having moderate pollution
potential, 22% as having high pollution potential, and 5% as having very high pollution potential. 相似文献
72.
Jennifer L. Cochran‐Biederman Katherine E. Wyman William E. French Grace L. Loppnow 《Conservation biology》2015,29(1):175-186
Reintroduction of imperiled native freshwater fish is becoming an increasingly important conservation tool amidst persistent anthropogenic pressures and new threats related to climate change. We summarized trends in native fish reintroductions in the current literature, identified predictors of reintroduction outcome, and devised recommendations for managers attempting future native fish reintroductions. We constructed random forest classifications using data from 260 published case studies of native fish reintroductions to estimate the effectiveness of variables in predicting reintroduction outcome. The outcome of each case was assigned as a success or failure on the basis of the author's perception of the outcome and on whether or not survival, spawning, or recruitment were documented during post‐reintroduction monitoring. Inadequately addressing the initial cause of decline was the best predictor of reintroduction failure. Variables associated with habitat (e.g., water quality, prey availability) were also good predictors of reintroduction outcomes, followed by variables associated with stocking (e.g., genetic diversity of stock source, duration of stocking event). Consideration of these variables by managers during the planning process may increase the likelihood for successful outcomes in future reintroduction attempts of native freshwater fish. Identificación de Correlaciones de Éxito y Fracaso de Reintroducciones de Peces de Nativos Agua Dulce 相似文献
73.
74.
Dr Hae K. Park Helen H. Kay Allyn McConkie-Rosell Joe Lanman Yuan-Tsong Chen 《黑龙江环境通报》1992,12(3):169-173
Uncultured trophoblasts obtained from chorionic villus biopsy during the gestation period of 8–12 weeks were assayed for alpha-glucosidase activity using maltose as the substrate. Only one major form of maltase activity with a pH optimum at 4.0 was demonstrated. Using this method, we performed prenatal diagnosis on three pregnancies at risk for the infantile form of type II glycogen storage disease. Two affected fetuses and one unaffected fetus were predicted and the diagnosis was subsequently confirmed. The maltose assay offered a direct, simple, and sensitive method for prenatal diagnosis of Pompe's disease in the first trimester. 相似文献
75.
Jack Mattice Myra Fraser Stephen Ragone David Daugherty Joe Wisniewski 《Environmental management》1996,20(6):781-788
The conference entitled Managing for Biodiversity: Emerging Ideas for the Electric Utility Industry was held in Williamsburg, Virginia, USA, during 19–20 March 1996. This paper provides an overview of the key points, conclusions, and recommendations from both the presentations/papers and the discussions throughout the conference. 相似文献
76.
Dr Mitchell S. Golbus Joe Leigh Simpson Sarah E. Fowler Felix de la Cruz Robert J. Desnick Ronald Wapner David H. Ledbetter Herbert Lubs Maurice J. Mahoney Eugene Pergament George G. Rhoads Joseph D. Schulman Julia Zachary 《黑龙江环境通报》1992,12(5):373-376
Factors found to be associated with pregnancy loss after transcervical CVS were race (higher for non-white), history of spontaneous abortion, unplanned pregnancy, history of spotting or bleeding during the pregnancy prior to CVS, and placental position (higher for fundal or lateral locations). Whether the increase in loss risk is due to the factor, per se, or the factor plus the CVS cannot be determined due to the lack of appropriate control data. 相似文献
77.
Susan J. Gross MD Owen P. Phillips Lee P. Shulman N. Lawrette Bright Jeffrey S. Dungan Joe Leigh Simpson Sherman Elias 《黑龙江环境通报》1994,14(7):609-613
An association between various abnormal mid-trimester maternal serum analyte values and adverse perinatal outcome has been reported. From an original sample of 14 857 women, we observed five women who were ‘screen-positive’ for both neural tube defects [maternal serum alpha-fetoprotein (MSAFP) ≥2·5 multiples of the median] and Down syndrome [risk ≥1/274 using MSAFP, maternal serum unconjugated oestriol (MSuE3), maternal serum human chorionic gonadotropin (MShCG), and maternal age]. The four patients who elected to undergo amniocentesis all demonstrated both normal karyotype and normal amniotic fluid AFP levels. All five cases were associated with intrauterine growth retardation (IUGR) and abnormal pregnancy outcomes. Two cases exhibiting severe IUGR on ultrasound examination were terminated at 19·1 and 21·2 weeks, respectively; the former also exhibited fetal calcifications and positive maternal serology for toxoplasmosis. In another case, fetal demise occurred at 36 weeks' gestation in a patient who had been treated for syphilis in the second trimester. Neither infection was confirmed in fetal tissue studies. Though resulting in live births, the remaining two cases required operative deliveries; emergency Caesarean sections for fetal distress were performed at 38 and 32 weeks, respectively, the latter case being associated with severe pre-eclampsia. We conclude that elevated mid-trimester MSAFP levels concurrent with maternal serum analyte values associated with increased risk for fetal Down syndrome may presage a poor perinatal outcome, particularly IUGR and possibly congenital infection. 相似文献
78.
N.?H.?LandmanEmail author J.?K.?Cochran R.?Cerrato J.?Mak C.?F.?E.?Roper C.?C.?Lu 《Marine Biology》2004,144(4):685-691
The age and habitat of the giant squid, Architeuthis sanctipauli Velain, 1877, were determined based on isotopic analyses of the statoliths of three female specimens captured off Tasmania, Australia, between January and March 1996. Assuming that the aragonite of the statoliths formed in equilibrium with seawater, 18O analyses indicated that the squid lived at temperatures of 10.5–12.9°C, corresponding to average depths of 125–250 m and maximum depths of 500 m. The capture records indicated that these squid may have occasionally ranged still deeper, to as much as 1000 m. All the statoliths were labeled with bomb 14C (14C=+22.9 to +44.6), consistent with the depths inferred from 18O. A thin section through one of the statoliths revealed 351 growth increments grouped into check-ring structures every 10–16 increments. A model for statolith growth and the pattern of temporal change in 14C in the water column was used to estimate the ages of the three specimens. These estimates were very sensitive to the choice of depth range over which 14C values were integrated. Assuming that the capture depths represented the maximum habitat depths of these individuals, the calculations suggested an age of 14 years or less. More refined age estimates require a better understanding of the variation of 14C and temperature with depth in the areas in which the squids live.Communicated by J.P. Grassle, New Brunswick 相似文献
79.
80.
Bron Taylor Guillaume Chapron Helen Kopnina Ewa Orlikowska Joe Gray John J. Piccolo 《Conservation biology》2020,34(5):1089-1096
Over the past 5 decades, scientists have been documenting negative anthropogenic environmental change, expressing increasing alarm, and urging dramatic socioecological transformation in response. A host of international meetings have been held, but the erosion of biological diversity continues to accelerate. Why, then, has no effective political action been taken? We contend that part of the answer may lie in the anthropocentric ethical premises and moral rhetoric typically deployed in the cause of conservation. We further argue that it is essential to advance moral arguments for biodiversity conservation that are not just based on perceived human interests but on ecocentric values, namely, convictions that species and ecosystems have value and interests that should be respected regardless of whether they serve human needs and aspirations. A broader array of moral rationales for biodiversity conservation, we conclude, would be more likely to lead to effective plans, adopted and enforced by governments, designed to conserve biological diversity. A good place to start in this regard would be to explicitly incorporate ecocentric values into the recommendations that will be made at the conclusion of the 15th meeting of the parties to the Convention on Biological Diversity, scheduled to be held in October 2020. 相似文献