A rare case of 68,XX triploidy diagnosed by amniocentesis

68,XX triploidy was found in the amniotic fluid cell culture of a 40-year-old patient. Elective termination of the pregnancy revealed a fetus with multiple congenital anomalies. While this case does show some common features with monosomy X, a greater similarity to the triploidy syndrome is observed.     

Optimizing two- and three-stage designs for spatial inventories of natural resources by simulated annealing

This paper reviews design-based estimators for two- and three-stage sampling designs to estimate the mean of finite populations. This theory is then extended to spatial populations with continuous, infinite populations of sampling units at the latter stages. We then assume that the spatial pattern is the result of a spatial stochastic process, so the sampling variance of the estimators can be predicted from the variogram. A realistic cost function is then developed, based on several factors including laboratory analysis, time of fieldwork, and numbers of samples. Simulated annealing is used to find designs with minimum sampling variance for a fixed budget. The theory is illustrated with a real-world problem dealing with the volume of contaminated bed sediments in a network of watercourses. Primary sampling units are watercourses, secondary units are transects perpendicular to the axis of the watercourse, and tertiary units are points. Optimal designs had one point per transect, from one to three transects per watercourse, and the number of watercourses varied depending on the budget. However, if laboratory costs are reduced by grouping all samples within a watercourse into one composite sample, it appeared to be efficient to sample more transects within a watercourse.     

Monitoring the effects of atmospheric ethylene near polyethylene manufacturing plants with two sensitive plant species

Data of a multi-year (1977-1983) biomonitoring programme with marigold and petunia around polyethylene manufacturing plants was analysed to assess plant responses to atmospheric ethylene and to determine the area at risk for the phytotoxic effects of this pollutant. In both species, flower formation and growth were severely reduced close to the emission sources and plant performance improved with increasing distance. Plants exposed near the border of the research area had more flowers than the unexposed control while their growth was normal. Measurements of ethylene concentrations at a border site revealed that the growing season mean was 61.5 g m(-3) in 1982 and 15.6 g m(-3) in 1983. In terms of number of flowers, petunia was more sensitive than marigold and adverse effects were observed within ca. 400 m distance from the sources for marigold and within ca. 460 m for petunia. The area at risk (ca. 870 m) for ethylene-induced growth reduction was also limited to the industrial zone. Plants were more sensitive to ethylene in terms of growth reduction than in terms of inhibition of flowering. In the Netherlands, maximum permissible levels of ethylene are currently based on information from laboratory and greenhouse studies. Our results indicate that these levels are rather conservative in protecting field-grown plants against ethylene-induced injury near polyethylene manufacturing plants.     

Statistical control of hygienic quality of bathing water

In Denmark the hygienic quality of the bathing water has been controlled, based on general guidelines since 1978. Today more than 1100 control sites in marine areas have been established to ensure safe bathing water quality. According to EEC directives and Danish tradition, the control is usually performed by measuring the content of the indicator bacteria Escherichia coli (E. coli) in 5 to 20 test samples each bathing season.In Denmark, control programmes and data are evaluated using basic statistical quality control principles. This paper presents general guidelines for bacterial control, their statistical background and practical application. Furthermore, the evaluation and application of a specific programme for control of Staphylococcus aureus (S. aureus) are presented. This programme was used in a Danish bay where the authorities prescribe direct control of these potentially harmful bacteria.     

Nematodes as indicators of ecosystem development during platinum mine tailings reclamation

As nematodes are widespread throughout the terrestrial ecosystem, and have shown potential to be used as indicators of ecosystem development. Nematode indices were used to distinguish between two different amendment types during platinum mine tailing reclamation. The two different amendment types include the use of woodchip-vermicompost and inorganic fertiliser. Both treatments had a higher number of nematodes than the natural veldt. Of the 17 genera identified, Rhabditis dominated in all sites. A significant difference (ANOVA; p < 0.05) was observed between Plant parasitic indices of both treatments and the natural veldt. The main decomposition pathway was dominated by bacterial decomposition for all sites as evident from the Channel index values. The dominance of bacterial feeding nematodes and the high number of nematodes feeding on higher plants indicate that the platinum mine tailings sites may be in an initial stage of succession. It is expected that the woodchip-vermicompost may have a low C:N ratio, causing the system to be nutrient enriched as indicated by the enrichment index. An increase in food-web development was observed in the woodchip-vermicompost sites indicating recovery from disturbance, during the third sampling period.     

Comparison of trace metal bioavailabilities in European coastal waters using mussels from Mytilus edulis complex as biomonitors

Mussels from Mytilus edulis complex were used as biomonitors of the trace metals Fe, Mn, Pb, Zn, and Cu at 17 sampling sites to assess the relative bioavailability of metals in coastal waters around the European continent. Because accumulated metal concentrations in a given area can differ temporally, data were corrected for the effect of season before large-scale spatial comparisons were made. The highest concentration of Fe was noted in the North Sea and of Mn in the Baltic. Increased tissue concentrations of Pb were recorded in the mussels from the Bay of Biscay and the Baltic Sea. Low concentrations of metals were determined in the mussels from the Mediterranean Sea and the Northern Baltic. Relatively low geographic variations of Cu and Zn indicate that mussels are able to partially regulate accumulated body concentrations, which means Cu and Zn are, to some extent, independent of environmental concentrations.     

Methane yield in source-sorted organic fraction of municipal solid waste

Treating the source-separated organic fraction of municipal solid waste (SS-OFMSW) by anaerobic digestion is considered by many municipalities in Europe as an environmentally friendly means of treating organic waste and simultaneously producing methane gas. Methane yield can be used as a parameter for evaluation of the many different systems that exist for sorting and pre-treating waste. Methane yield from the thermophilic pilot scale digestion of 17 types of domestically SS-OFMSW originating from seven full-scale sorting systems was found. The samples were collected during 1 year using worked-out procedures tested statistically to ensure representative samples. Each waste type was identified by its origin and by pre-sorting, collection and pre-treatment methods. In addition to the pilot scale digestion, all samples were examined by chemical analyses and methane potential measurements. A VS-degradation rate of around 80% and a methane yield of 300-400Nm(3) CH(4)/ton VS(in) were achieved with a retention time of 15 days, corresponding to approximately 70% of the methane potential. The different waste samples gave minor variation in chemical composition and thus also in methane yield and methane potential. This indicates that sorting and collection systems in the present study do not significantly affect the amount of methane produced per VS treated.     

Composition of source-sorted municipal organic waste collected in Danish cities

Source-sorted municipal organic waste from different dwelling types in five Danish cities was sampled during one year. The samples were from permanent, full-scale systems or temporary, experimental systems for collection of source-sorted municipal organic waste. Pre-treatment of the organic waste prior to biological treatment was used in all cities to remove foreign objects and provide size reduction. All sampling was performed after pre-treatment in order to obtain more homogeneous and representative samples. The sampling included both the pre-treated waste and the reject from the pre-treatment allowing for estimation of the composition of the original waste. A total of 40 waste samples were chemically characterised with respect to 15 parameters. The waste generally consisted of around 88% VS of which an average of 80% was easily degradable. The average content of N, P and K in the dry matter of the organic waste was 2.5%, 0.4% and 0.9%, respectively. A general analysis of variance was applied to show the influence of the collection system, dwelling type and annual season on the waste composition. The content of plastic and crude fibres in the waste differed the most among the samples, probably due to use of different bag types (plastic and paper) in the different collection systems. Variations in the ash content and the calorific value might be explained by differences in the sorting instructions (whether soil and cat litter are allowed in the organic fraction). Significant seasonal variations were seen for ash, S and Cl. Dwelling type showed no statistically significant influence on any waste components. A test for uniform distribution of the p-values from the analysis of variance (Kolmogorov-Smirnov test) showed that the overall composition of the collected waste was strongly affected by the collection system (city) and season, while dwelling type had no significant influence.