Batch studies of phosphonate adsorption on granular ferric hydroxides.

Phosphonates are widely used in various industries. It is desirable to remove them before discharging phosphonate-containing wastewater. This study describes a large number of batch experiments with adsorbents that are likely suitable for the removal of phosphonates. For this, adsorption isotherms for four different granular ferric hydroxide (GFH) adsorbents were determined at different pH values in order to identify the best performing material. Additionally, the influence of temperature was studied for this GFH. A maximum loading for nitrilotrimethylphosphonic acid (NTMP) was found to be ∼12 mg P/g with an initial concentration of 1 mg/L NTMP-P and a contact time of 7 days at room temperature. Then, the adsorption of six different phosphonates was investigated as a function of pH. It was shown that GFH could be used to remove all investigated phosphonates from water and, with an increasing pH, the adsorption capacity decreased for all six phosphonates. Finally, five adsorption-desorption cycles were carried out to check the suitability of the material for multiple re-use. Even after five cycles, the adsorption process still performed well.

A comparison of ecological optima of soft-bodied benthic algae in Norwegian and Austrian rivers and consequences for river monitoring in Europe.

Alpine and Nordic rivers are often considered as being among the most pristine in Europe. Nevertheless, acidification and eutrophication impact surface waters in these regions. Soft-bodied, i.e. non-diatom, benthic algae are used as indicators for eutrophication and acidification in both Norway and Austria, but consistency of indicator values has never been tested. We compared species optima with respect to pH, conductivity, total phosphorus (TP), and NO3(-)-N concentration for 21 species, derived from geographically and temporally extensive datasets from Norway and Austria, respectively. The ranges of all four measured parameters were different between Norway and Austria, with Austria having generally higher values for all measured parameters. Optima for all 21 species with respect to pH, conductivity and NO3(-)-N were significantly different between Norway and Austria, while 5 of the 21 taxa showed no significant differences for TP. Nevertheless, species optima for Norway and Austria were significantly correlated with each other for TP, pH and conductivity. This indicates that positions of species optima relative to each other may be stable across ecoregions, in spite of the absolute values of species optima being different. In contrast, optima with respect to NO3(-)-N were not correlated, possibly suggesting a lesser importance of NO3(-) in shaping benthic algal assemblages than TP and pH. We conclude that the use of eutrophication and acidification models across different ecoregions may give meaningful results, but requires regional testing of species optima.

Spatial variation of phytoplankton composition, biovolume, and resulting microcystin concentrations in the Nyanza Gulf (Lake Victoria, Kenya).

The Nyanza Gulf is a large shallow bay of Lake Victoria suffering from eutrophication by human activities. In order to characterize the harmful algal bloom formation as a consequence of eutrophication, both spatially and seasonally, environmental conditions, phytoplankton community composition, and microcystin (MC) concentrations were investigated monthly from Kisumu Bay, and bimonthly from the center of the gulf, as well as quarterly from the Rusinga Channel and the main basin of Lake Victoria between July 2008 to September 2009. The sites located in Kisumu Bay and the central gulf were most strongly affected by eutrophication, including increased nutrient concentrations and phytoplankton growth. More than 90% of the samples obtained from the gulf were dominated by cyanobacteria, whereas diatoms only dominated in the samples obtained from Rusinga Channel and the main lake. In general Microcystis accounted for the largest part (> 50-90%) of cyanobacterial biovolume. MCs were found in 35 (54%) out of 65 samples and were detected throughout the study period in the gulf, but only in two out of eight samples from the Rusinga Channel and the main lake. A significant linear relationship between Microcystis biovolume and MC concentration was observed (n = 65, R2 = 0.88, p <0.001). Highest MC concentrations were recorded in Kisumu Bay between November and March (max. 81 µg l-1) when Microcystis showed max. biovolume (18 mm3 l-1 in November 2008). The results suggest that seasonal variability did not outweigh the spatial differences in phytoplankton composition and MC production that is seasonally persistent in Kisumu Bay.

Cell morphology, ultrastructure, and calcification pattern of Oocardium stratum, a peculiar lotic desmid.

Cell morphology and ultrastructure of the desmid Oocardium stratum and its habitat conditions in two limestone-precipitating spring habitats in the Alps were studied. In spite of specific cell geometry, we found ultrastructural features (nucleus with nucleolus, Golgi apparatus, chloroplast structure, lipid bodies, cell wall texture) closely related to other desmids. The type of the mucilage pore apparatus perforating in high densities extended areas of the cell wall of Oocardium is of the Cosmarium type. Oocardium contrasts to Cosmarium by a peculiar bilateral cell geometry (lateral sphenoid shape) which is combined with a dislocated nucleus. Although the cell features of Oocardium did not differ between the two habitats, different calcification types (rhombohedral calcite versus fascicular-fibrous calcite) and calcification intensities were recorded. The spatial positioning and extension of the Oocardium niches differed considerably between the two springs in spite of high CO(2) oversaturation at both sites.

Methylenetetrahydrofolate reductase and spina bifida: evaluation of level of defect and maternal genotypic risk in Hispanics.

The C677T and A1298C mutations in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene are each associated with reduced MTHFR activity. The C677T mutation in the heterozygous and homozygous state correlates with increased enzyme thermolability, with homozygous mutant genotypes showing significantly elevated plasma homocysteine levels and decreased plasma folate levels. The A1298C mutation results in decreased MTHFR activity, but changes in neither homocysteine nor folate levels are associated with A1298C variant genotypes. Our study determined the frequencies of the C677T and A1298C MTHFR mutations for spina bifida (SB) cases, mothers and fathers of SB cases, and controls in Hispanics of Mexican-American descent. In addition, our subject population was further categorized as to whether the spina bifida lesion occurred as an upper or lower level defect, according to the Van Allen "multi-site closure" model. Hispanic SB cases with upper level defects and their mothers were homozygous for the C677T variant allele at a higher rate than their respective controls (OR = 1.5 [95% CI 0.8-2.9], P = 0.30; OR = 2.3 [1.1-4.8], P = 0.04, respectively), with statistically significant results seen only for the maternal homozygous genotype. Homozygosity for the A1298C mutation was seen at a higher rate only in Hispanic mothers of both upper and lower level SB cases when compared to controls, but these results were not statistically significant. Our study provides evidence that the maternal C677T MTHFR homozygous mutant genotype is a risk factor for upper level spina bifida defects in Hispanics.

Is there a safe therapeutic window for delivery of chemotherapy prior to initiation of surgery and/or radiation-therapy for treatment of the primary tumor in children with rhabdomyosarcoma.

To avoid the delayed consequences of treatment with radiotherapy, an effort was made to determine if patients with rhabdomyosarcoma could be cured with chemotherapy as the sole form of treatment. Alternatively, if radiotherapy and/or surgery were required to reduce the severity and incidence of delayed sequelae, an effort was made to determine if there was an optimum safe period for delaying implementation of these definitive forms of treatment. In patients where primary (immediate) definitive non-mutilating surgical extirpation of tumor was not feasible, exclusive treatment with chemotherapy was implemented. If considered necessary or appropriate, delayed surgery and/or radiation therapy were employed in 3 circumstances: (i) to consolidate a partial response; (ii) failure to respond; (iii) recurrent disease. The outcome of the delays prior to the implementation of definitive therapy was analyzed as a function of local and systemic recurrence and cure. Fifty-two patients were evaluated. Seven underwent primary non-mutilating surgical extirpation of localized tumor followed by adjuvant chemotherapy. The remaining 45 were treated with primary chemotherapy and 44 responded. Actuarial survival curves of the delay in initiating definitive therapy in the 52 patients revealed that the optimum delay to attain the best survival was 5 months. In circumstances where definitive therapy was not electively introduced, recurrent disease during remission appeared between 7 and 14 months in 7 patients on continued treatment, and in one patient at 30 months, 8 months after discontinuation of chemotherapy. Based upon the 5-month delay an analysis of survival was performed: Definitive therapy was introduced in 14 patients within 5 months and 7 were cured. In the remaining 31 patients, definitive therapy was introduced between 5 and 30 months and 15 were cured. The five month delay is supported empirically by tumor doubling times. No patient was cured exclusively with chemotherapy.

[Biolgical problems of a manmade small lake (author's transl)]. / Zur Biologie eines künstlich entstandenen Kleinbadesees

In connection with an intensive hygienic supervision of public bathing facilities and the attempts to draw up a law on bathing hygiene, the lack of contamination standards for small lakes available to the public for bathing was particularly conspicuous. In addition to the current chemical and bacteriological routine examinations, a small bathing lake with a surface area of 3000 square metres containing about 7000 m3 of water and which has been in existence for over 10 years was objected to extensive biological investigations during the months July to September. The results of the analysis show a relatively constant hydrogen ion concentration (pH 8.2), small variations in electrolytic conductivity and 8 German degrees of hardness. The mean phosphourus level was 60 mug/L. the orthophosphate levels ranged between 5.2 and 18.5 mug/L. Oxygen saturation during the entire summer months was more than 100%. Altogether, 49 different kinds of phytoplankton- and 12 kinds of zooplancton-organisms were identified. The total biological mass of phytoplancton organisms was between 8.5 and 16 mg fresh weight per litre, bacterial biomass varied between 4.5 and 9.5 mg/l. Particularly striking for summer conditions was the high proportion of Cyclotella- and Synedra species among the phytoplancton mass, while the algal-bloom producing Microcystis flos aquae attained a maximum proportion of 15%. In spite of the great variety of its forms, green algae were present in small numbers only. The comparison of the described findings with the trophic-systems of HUTCHINSON, NYGAARD and RAWSON indicated an eutrophic type of lake; classification according to the types of the various saprobic systems of NAUMANN, KOLKWITZ and LIEBMANN yielded a predominantly beta-mesosaprobic type of lake. The investigations described show, however, that this is probably a lake rich in nutrients, but that there is a relatively stable biological equilibrium and that, consequently, there is no further threat of progressive eutrophism. Special hygienic parameters, contamination due to visitors and phytoplancton production will be reported in a second communication.