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561.
We report an unusual case of the complete Currarino triad diagnosed in a fetus at 21 weeks' gestation by means of prenatal ultrasonography (US). The highly suspicious findings in the fetus were accompanied by analogous US findings in the mother who suffered from mild symptoms of up to that time unrecognized Currarino triad. Consecutively, magnetic resonance imaging (MRI) confirmed the findings simultaneously in the fetus and in her mother. This is the first report describing the prenatal diagnosis of Currarino triad without the background of positive family history. To our knowledge, the prenatal MRI findings of Currarino triad have not yet been published. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
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563.
Gordana Marović Jasminka Senčar Zdenko Franić 《Environmental monitoring and assessment》1997,46(3):233-239
The presence of 226Ra in drinking water may sometimes make important contribution to natural background radiation exposures. The paper describes the study of 226Ra content in drinking water of Croatia: tap water from the public supply system of several major towns and bottled mineral water from two selected mineral water springs. 226Ra was determined by alpha-spectrometric measurement after radiochemical separation. The radiation doses originating from drinking tap water and bottled mineral water were estimated. The annual dose from consumption of bottled mineral water was compared to that received from ingestion of public system tap water. The study showed that 226Ra content for investigated categories of waters is below the levels at which any unacceptable dose due to ingestion would arise. 相似文献
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567.
Milačič R Zuliani T Oblak T Mladenovič A Ančar JŠ 《Journal of environmental quality》2011,40(4):1153-1161
Electric arc furnace (EAF) steel slag can be used as an alternative high-quality material in road construction. Although asphalts with slag aggregates have been recognized as environmentally acceptable, there is a lack of data concerning the potential leaching of toxic Cr(VI) due to the highly alkaline media of EAF slag. Leaching of selected water extractable metals from slag indicated elevated concentrations of total chromium and Cr(VI). To estimate the environmental impacts of asphalt mixes with slag, leachability tests based on diffusion were performed using pure water and salt water as leaching agents. Compact and ground asphalt composites with natural aggregates, and asphalt composites in which the natural aggregates were completely replaced by slag were prepared. The concentrations of total chromium and Cr(VI) were determined in leachates over a time period of 6 mo. After 1 and 6 mo, the concentrations of some other metals were also determined in the leachates. The results indicated that chromium in leachates from asphalt composites with the addition of slag was present almost solely in its hexavalent form. However, the concentrations were very low (below 25 μg L) and did not represent an environmental burden. The leaching of other metals from asphalt composites with the addition of slag was negligible. Therefore, the investigated EAF slag can be considered as environmentally safe substitute for natural aggregates in asphalt mixes. 相似文献
568.
Una Andersone Ieva Druva-Lūsīte Baiba Ieviņa Andis Karlsons Jevgenija Ņečajeva Ineta Samsone Gederts Ievinsh 《Journal of Coastal Conservation》2011,15(4):509-522
Eryngium maritimum is a perennial species growing exclusively in a coastal littoral zone both on sand dunes and shingle beach and indicated
as declining in Northern Europe. The objective of the present study was to prove the use of nondestructive physiological measurement
methods to access physiological status of endangered plants, using E. maritimum as a model species. Plants from two Latvian sites were studied in comparison with other populations in Northern Europe (Estonia,
Lithuania, Poland, United Kingdom) to find out if local differences in environmental factors affect vitality of E. maritimum individuals. Noninvasive chlorophyll analysis and chlorophyll a fluorescence measurements were used as indicators of plant physiological status through characterization of various aspects
of photochemistry of photosystem II activity. Dynamics and morphology of individuals were investigated for evaluation of clonal
growth potential of E. maritimum in natural conditions. Highly fluctuating trend of dynamics of individuals (within 40 groups at two Latvian sites) was established
for E. maritimum in natural conditions over a five-year period. Disturbance of individuals lead to formation of new shoots from nodal root
meristems. An exponential regression between fluorescence parameters FV/FM and Performance Index and summary monthly precipitation was found indicating that E. maritimum plants had significant tolerance to water shortage together with susceptibility to increased precipitation. Negative correlation
between leaf chlorophyll content and more northern localization of individuals was found (r = 0.95 and r = 0.94, for generative and vegetative shoots, respectively). Northern populations of E. maritimum are endangered by high precipitation in conditions of low air temperature, leading to decrease of photosynthetic productivity
and overall physiological status. High developmental plasticity at the root level leads to clonal growth and an efficient
survival and relatively long life span of E. maritimum individuals. Chlorophyll a fluorescence is a useful method to search for the effect of suboptimal conditions on physiological status of endangered plant
species without elimination and disturbance of individuals. 相似文献
569.
Ivana Teodorović Sonja Kaišarević Kristina Pogrmić-Majkić Ivana Planojević Svetlana Fa Vanja Dakić Jelena Hrubik Branka Glišić Radmila Kovačević 《Environmental Sciences Europe》2011,23(1):1-9
Background
In order to map exceedances of critical atmospheric deposition loads for nitrogen (N) surface data on the atmospheric deposition of N compounds to terrestrial ecosystems are needed. Across Europe such information is provided by the international European Monitoring and Evaluation Programme (EMEP) in a resolution of 50 km by 50 km, relying on both emission data and measurement data on atmospheric depositions. The objective of the article at hand is on the improvement of the spatial resolution of the EMEP maps by combining them with data on the N concentration in mosses provided by the International Cooperative Programme on Effects of Air Pollution on Natural Vegetation and Crops (ICP Vegetation) of the United Nations Economic Commission for Europe (UNECE) Long-range Transboundary Air Pollution (LTRAP) Convention.Methods
The map on atmospheric depositions of total N as modelled by EMEP was intersected with geostatistical surface estimations on the N concentration in mosses at a resolution of 5 km by 5 km. The medians of the N estimations in mosses were then calculated for each 50 km by 50 km grid cell. Both medians of moss estimations and corresponding modelled deposition values were ln-transformed and their relationship investigated and modelled by linear regression analysis. The regression equations were applied on the moss kriging estimates of the N concentration in mosses. The respective residuals were projected onto the centres of the EMEP grid cells and were mapped using variogram analysis and kriging procedures. Finally, the residual and the regression map were summed up to the map of total N deposition in terrestrial ecosystems throughout Europe.Results and discussion
The regression analysis of the estimated N concentrations in mosses and the modelled EMEP depositions resulted in clear linear regression patterns with coefficients of determination of r 2 = 0.62 and Pearson correlations of r p = 0.79 and Spearman correlations of r s = 0.70, respectively. Regarding the German territory a nationwide mean of 18.1 kg/ha/a (standard deviation: 3.49 kg/ha/a) could be derived from the resulting map on total N deposition in a resolution of 5 km by 5 km. Recent updates of the modelled atmospheric deposition of N provided a similar estimate for Germany.Conclusions
The linking of modelled EMEP data on the atmospheric depositions of total N and the accumulation of N in mosses allows to map the deposition of total N in a high resolution of 5 km by 5 km using empirical moss data. The mapping relies on the strong statistical relationship between both processes that are physically and chemically related to each other. The mapping approach thereby relies on available data that are both based on European wide harmonized methodologies. From an ecotoxicological point of view the linking of data on N depositions and those on N bioaccumulation can be considered a substantial progress. 相似文献570.
This study deals with numerical simulation of flow fields and dispersion of model passive admixtures in the planetary boundary
layer in a 10 × 10 km square area, centered on the Czech Republic’s Temelín Nuclear Power Plant. Numerical calculations of
three-dimensional flow fields with eight basic wind directions given for the inlet boundary of the computational domain are
performed using the FLUENT CFD code with the standard k – ε turbulence model. The resultant modeling of the flow fields provides information as to probable local directions and velocities
of flow vectors on a horizontal scale of 100 m, which are consistent with the data given for the boundaries of the calculation
area in the framework of a scale of 10 km. The modeled flow fields generate the input data for related Lagrangian simulation
of the ground concentration and deposition fields of passive particles assumedly emitted at the site of the Temelín plant.
Simulated plumes describe eight cases of potential ground-level distribution of model passive admixtures in the area. 相似文献