Dioxine sind weit verbreitete Umweltschadstoffe. Ähnlich wie die weiblichen Geschlechtshormone, die Östrogene, sind sie in der Lage, in das Hormonsystem wild lebender Arten einzugreifen. So beeinträchtigen sie z. B. die Fortpflanzungsfähigkeit von Fischen. Um die Risiken von Dioxinen auf Gewässerorganismen besser einschätzen zu können, untersuchten wir, ob sie die Expression eines normalerweise durch Östrogene regulierten Gens verändern.

Weibliche Geschlechtshormone, die Östrogene, können ihre Wirkung erst ausüben, wenn sie von Östrogenrezeptoren erkannt werden. Doch was geschieht, wenn die Bildung der Rezeptoren unterdrückt wird? Dies untersuchten wir an Zebrabärblingen. Ein besonders auffälliges Merkmal dieser «Knock down»-Zebrabärblinge war ihr Verhalten, ständig im Kreis zu schwimmen. Ihnen fehlte das Seitenlinienorgan, mit dem sie sich normalerweise orientieren.

Schlüsselenzym der Östrogen-Biosynthese ist die Cytochrom-P450-Aromatase. Sie katalysiert die entscheidende Reaktion, nämlich die Umwandlung der Androgene in Östrogene und bestimmt so die Höhe des Östrogenspiegels. Anhand von Zebrabärblingen untersuchten wir, ob die Aromatase die Entstehung der Geschlechtsorgane und des Seitenlinienorgans steuert.

Vor gut 8 Jahren wurde in der Abteilung Umwelttoxikologie die Forschung an Zebrabärblingen gestartet. Ein aktives Team rund um den Molekularbiologen Rik Eggen arbeitet seither mit diesem neuen Modellorganismus. Nun ist es an der Zeit, die Wissenschaftlerinnen und Wissenschaftler zu Wort kommen zu lassen.

The authors of this article have recently developed COMLIZER, a fertiliser made of municipal solid waste, faecal sludge and mineral fertiliser. Since this new product meets the crop nutrient requirements and has an excellent soil conditioning quality, it has become an attractive source of nutrients for farmers.

Poor soil fertility is a key factor limiting crop production in many parts of the tropics. Nitrogenenriched waste products have the potential to improve crop yield on depleted soils and provide high financial returns.

The Household-Centred Environmental Sanitation (HCES) approach was applied to improve sanitation in a neighbourhood of Vientiane, Laos. Experience underlines the importance of a sound stakeholder analysis and involvement.

To date, no appropriate fluoride removal technology has yet been successfully implemented in the Ethiopian Rift Valley. Filtration with bone char is known to be an efficient process in removing fluoride. However, is its use also compatible with religious beliefs in Ethiopia?

Allegations of health risks related to carcinogenic substances from PET bottle material in drinking water are circulating in the media of countries where such bottles are used for SODIS (solar water disinfection). A recent study shows that there is no reason for concern.

Faecal sludge treatment is a key factor for controlling and reducing the impact of faecal matter from on-site sanitation systems used by more than 80 % of the African population. Yet, technical recommendations are still scarce and inaccurate. Since 2006, a treatment system using unplanted drying beds has been implemented and operated by ONAS (The National Sanitation Utility) in Dakar, Senegal. It offers a unique opportunity to formulate general recommendations for technical design and budgeting.

Composting is a proven technology for organic waste treatment under certain site and contextspecific conditions. Nevertheless, there is still scope for improvement by increasing the value and potential benefits of organic waste treatment and its products. Sandec is currently evaluating and developing a CORS system using larvae of the Black Soldier Fly for organic waste treatment in low and middle-income countries.

Federal regulation in Germany made decentralised wastewater treatment solutions viable alternatives to large sewer network systems. The implementation, however, is weakened due to path dependence.

Unterschlupf- und Beuteangebot bestimmen die Grösse des Sommerlebensraumes zweier Krötenarten im aktiven Geschiebebereich der natürlichen Flussaue des Tagliamento. Das Schwemmholzangebot spielt dabei eine Schlüsselrolle. Grossräumige Flussvitalisierungen eignen sich zur Wiederherstellung terrestrischer Amphibienhabitate. Lukas Indermaur hat am letzten grossen Wildfluss der Alpen seine Doktorarbeit verfasst.

In combination with monitoring technologies already installed at a station in the Rhine catchment system, a new analytical method should make it almost impossible for pollutant waves following major accidents to flow undetected. Andrl Bryner of the Swiss Federal Institute for Aquatic Science and Technology (Eawag) reports on the results of an ongoing investigation of the latest analytical methods.

This paper summarizes the initial results from the long-term monitoring program of running and standing waters in a high elevation cirque landscape (Macun Lakes) in the Swiss National Park. The region comprises two contrasting basins with different water sources, a glacier-fed basin and a precipitation-fed basin. Monitoring encompasses annual measures of physico-chemistry of the waters along with samples of macroinvertebrates in midsummer. Monitoring was initiated in 2001 when the area was annexed to the park. Preliminary results indicate the high sensitivity of alpine waters and biota to changes in climate. Results from the stream measures suggest a shift in physico-chemistry (warmer waters, decreases in nitrogen constituents) and zoobenthos (taxa and density decreases) over time that reflected the differences and changes in water source in each basin. Results from the pond monitoring showed the rapid response of these small water bodies to alterations in air temperature and pluviometry. The pond data also demonstrated a strong spatial heterogeneity between ponds in both physico-chemistry and macroinvertebrate composition. The monitoring of both streams and ponds provides a holistic picture of abiotic and biotic changes of alpine waters to landscape and climate change.

Le Cameroun est un pays d'Afrique centrale dont les besoins en eau potable sont encore énormes. En effet, l'adduction des eaux de la ville de Yaoundé, assurée par la Camwater, enregistre une couverture de moins de 50 % des besoins. Les populations les plus vulnérables recourent aux eaux des puits et des sources pour la boisson, ainsi que pour différentes activités domestiques.

An international expedition investigating the disappearance of the almost legendary white-flag dolphin (baiji) and the threatened finless porpoise Neophocaena phocaenoides asiaorientalis in the Yangtze River revealed surprising water quality data. Authors Beat Müller, Michael Berg, and August Pfluger,who participated in the extinction of the baiji.

Alkylphenolic compounds derived from microbial degradation of non-ionic surfactants became a major focus of environmental research in the early 1980s. More toxic than the parent compounds and weakly oestrogenic, certain metabolites of nonylphenol polyethoxylate (NP<I>n</I>EO) surfactants, especially nonylphenol (NP), raised sustained concern over the risk they pose to the environment and triggered legal measures as well as partly voluntary actions by the manufacturing industry. Continuous progress in the development of analytical techniques is crucial to understand how these alkylphenolic compounds behave in wastewater treatment, the aquatic environment and in laboratory experiments. Measured concentrations and mass flows of phenolic endocrine disruptors, particularly nonylphenolic compounds, bisphenol A and parabens in municipal wastewater effluents and in the Glatt River, Switzerland, show that rain events leading to discharges of untreated wastewater into rivers have a great impact on the riverine mass flows of contaminants. Biotransformation experiments in our laboratory with nonylphenoxyacetic acid and individual NP isomers enabled the elucidation of degradation pathways of these compounds. The finding that nonylphenoxyacetic acid is metabolized via NP further underscores the role of NP as the most relevant metabolite in the degradation of NP<I>n</I>EO. Several <I>Sphingomonadaceae</I> bacterial strains were found to degrade <I>α</I>-quaternary 4-NP isomers by an <I>ipso</I>-substitution mechanism, and to use only the aromatic part of the molecule. These reactions turned out to be isomer specific, meaning that rate and extent of transformation depend on constitution, and possibly also on the absolute configuration of the alkyl side chain of a specific isomer. The observation that NP isomers with distinct oestrogenic activities are differentially degraded has significant implications for risk assessment.

This paper investigates the relationship between the income growth and the trend in industrial wastewater discharge in China during the period 1981-2007. For the data encompassing all the provinces over the entire period considered, both an inverted U-shaped EKC and an N-shaped EKC are statistically significant. An analysis dividing provinces into rich and poor groups reveals that the EKC relations are mainly governed by the rich province group. The EKC relations for the poor province group are either not found or are statistically weak. A further analysis based on dividing the data into before and after the year 2000 is in favour of the quadratic EKC model. The results of this study show that the relationships between a given pollutant and income are temporal and spatial specific depending on the driving forces behind. This implies that results derived from one study for certain regions/countries and for a specific time period may not be generalized for other regions/countries and extrapolated to other periods.

The Chaobai watershed in northern China is the most important source of drinking water for Beijing. The level of fertilizer use, especially overuse, as well as farming practices in the region have therefore a great impact on the water quality downstream. This study analyses the factors influencing farmers' decision on fertilizer use and the implications for water quality. The analysis is based on a survey of 349 farm households. It takes into consideration both farm and farmer specific characteristics and farmers' subjective evaluation of factors shaping their decisions. Regression models are used to examine the determinants of fertilizer use intensity across farm households and to investigate the factors influencing the overuse of nitrogen. The results suggest the significance of many of these 'subjective' factors, indicating the importance of considering them in the analyses. The results also show that irrigation, gains in crop yield and farming goal of earning are positively correlated to fertilizer use intensity while farm size, manure application, soil fertility and the distance to fertilizer market are negatively correlated. Investigation of the overuse problem shows that higher education level significantly reduces the probability of overfertilization. Based on these findings a few policy relevant implications are discussed.

Cellulose acetate 0.45-μm syringe filters could be used to filter environmental samples containing steroidal hormones, such as estradiol, prior to analysis. Such pretreatment may result in significant loss of analyte due to either adsorption of analyte to the filter material or association with retained colloidal and particulate materials. To determine the quantity of such losses, several experiments were performed by filtering water spiked with estradiol at different concentrations (50, 100, and 500ng/L) and pH (3–12) through cellulose acetate syringe filters. Further, the influence of added organic matter was studied. At all concentrations the experiments indicated that below pH 11, up to 50% of estradiol in the feed was adsorbed on the filter. This occurred regardless of the presence of bulk organic matter in solution, and was related to dissociation of estradiol with pH and subsequent changes in filter interaction. As a consequence, pretreatment of solutions containing estradiol should be adjusted to greater than pH 11 prior to filtration with 0.45-μm cellulose acetate filters.

Background: Rates of molecular evolution vary widely among species. While significant deviations from molecular clock have been found in many taxa, effects of life histories on molecular evolution are not fully understood. In plants, annual/perennial life history traits have long been suspected to influence the evolutionary rates at the molecular level. To date, however, the number of genes investigated on this subject is limited and the conclusions are mixed. To evaluate the possible heterogeneity in evolutionary rates between annual and perennial plants at the genomic level, we investigated 85 nuclear housekeeping genes, 10 non-housekeeping families, and 34 chloroplast genes using the genomic data from model plants including <I>Arabidopsis thaliana </I>and <I>Medicago truncatula </I>for annuals and grape (<I>Vitis vinifera</I>) and popular (<I>Populus trichocarpa</I>) for perennials.<BR/>Results: According to the cross-comparisons among the four species, 74-82% of the nuclear genes and 71-97% of the chloroplast genes suggested higher rates of molecular evolution in the two annuals than those in the two perennials. The significant heterogeneity in evolutionary rate between annuals and perennials was consistently found both in nonsynonymous sites and synonymous sites. While a linear correlation of evolutionary rates in orthologous genes between species was observed in nonsynonymous sites, the correlation was weak or invisible in synonymous sites. This tendency was clearer in nuclear genes than in chloroplast genes, in which the overall evolutionary rate was small. The slope of the regression line was consistently lower than unity, further confirming the higher evolutionary rate in annuals at the genomic level.<BR/>Conclusions: The higher evolutionary rate in annuals than in perennials appears to be a universal phenomenon both in nuclear and chloroplast genomes in the four dicot model plants we investigated. Therefore, such heterogeneity in evolutionary rate should result from factors that have genome-wide influence, most likely those associated with annual/perennial life history. Although we acknowledge current limitations of this kind of study, mainly due to a small sample size available and a distant taxonomic relationship of the model organisms, our results indicate that the genome-wide survey is a promising approach toward further understanding of the mechanism determining the molecular evolutionary rate at the genomic level.

This case study deals with long-term contamination of the Leuna aquifer, which is intended to be restored using sustainable technologies financed by the state. The contamination can only be solved using active rather than passive intervention, because the aquifer has an extraordinarily low natural attenuation capacity for the specific pollutants. Due to the longevity of the contamination source, the groundwater treatment technology that was chosen for the site must operate for a minimum of 20 years but probably much longer. Since the polluter-pay principle cannot be applied, the estimated dynamic primary remediation costs must be accepted as a political or social cost, which must be paid by current and future generations.

In many animals, sexual selection on male traits results from female mate choice decisions made during a sequence of courtship behaviors. We use a bower-building cichlid fish, <I>Nyassachromis</I> cf. <I>microcephalus</I>, to show how applying standard selection analysis to data on sequential female assessment provides new insights into sexual selection by mate choice. We first show that the cumulative selection differentials confirm previous results suggesting female choice favors males holding large volcano-shaped sand bowers. The sequential assessment analysis reveals these cumulative differentials are the result of selection acting on different bower dimensions during the courtship sequence; females choose to follow males courting from tall bowers, but choose to engage in premating circling with males holding bowers with large diameter platforms. The approach we present extends standard selection analysis by partitioning the variances of increasingly accurate estimates of male reproductive fitness and is applicable to systems in which sequential female assessment drives sexual selection on male traits.

A major goal of evolutionary biology is to unravel the molecular genetic mechanisms that underlie functional diversification and adaptation. We investigated how changes in gene regulation and coding sequence contribute to sensory diversification in two replicate radiations of cichlid fishes. In the clear waters of Lake Malawi, differential opsin expression generates diverse visual systems, with sensitivities extending from the ultraviolet to the red regions of the spectrum. These sensitivities fall into three distinct clusters and are correlated with foraging habits. In the turbid waters of Lake Victoria, visual sensitivity is constrained to longer wavelengths, and opsin expression is correlated with ambient light. In addition to regulatory changes, we found that the opsins coding for the shortest- and longest-wavelength visual pigments have elevated numbers of potentially functional substitutions. Thus, we present a model of sensory evolution in which both molecular genetic mechanisms work in concert. Changes in gene expression generate large shifts in visual pigment sensitivity across the collective opsin spectral range, but changes in coding sequence appear to fine-tune visual pigment sensitivity at the short- and long-wavelength ends of this range, where differential opsin expression can no longer extend visual pigment sensitivity.

Background: Transgressive segregation describes the occurrence of novel phenotypes in hybrids with extreme trait values not observed in either parental species. A previously experimentally untested prediction is that the amount of transgression increases with the genetic distance between hybridizing species. This follows from QTL studies suggesting that transgression is most commonly due to complementary gene action or epistasis, which become more frequent at larger genetic distances. This is because the number of QTLs fixed for alleles with opposing signs in different species should increase with time since speciation provided that speciation is not driven by disruptive selection. We measured the amount of transgression occurring in hybrids of cichlid fish bred from species pairs with gradually increasing genetic distances and varying phenotypic similarity. Transgression in multi-trait shape phenotypes was quantified using landmark-based geometric morphometric methods.<BR/>Results: We found that genetic distance explained 52% and 78% of the variation in transgression frequency in F1 and F2 hybrids, respectively. Confirming theoretical predictions, transgression when measured in F2 hybrids, increased linearly with genetic distance between hybridizing species. Phenotypic similarity of species on the other hand was not related to the amount of transgression.<BR/>Conclusion: The commonness and ease with which novel phenotypes are produced in cichlid hybrids between unrelated species has important implications for the interaction of hybridization with adaptation and speciation. Hybridization may generate new genotypes with adaptive potential that did not reside as standing genetic variation in either parental population, potentially enhancing a population's responsiveness to selection. Our results make it conceivable that hybridization contributed to the rapid rates of phenotypic evolution in the large and rapid adaptive radiations of haplochromine cichlids.

Background: Conflicts of interest between the sexes are increasingly recognized as an engine driving the (co-)evolution of reproductive traits. The reproductive behaviour of <I>Drosophila montana</I> suggests the occurrence of sexual conflict over the duration of copulation. During the last stages of copulation, females vigorously attempt to dislodge the mounting male, while males struggle to maintain genital contact and often successfully extend copulations far beyond the females' preferred duration.<BR/>Results: By preventing female resistance, we show that females make a substantial contribution towards shortening copulations. We staged matings under different sex ratio conditions, and provide evidence that copulation duration is a form of male reproductive investment that responds to the perceived intensity of sperm competition as predicted by game theoretical models. Further, we investigated potential benefits to persistent males, and costs to females coerced into longer matings. While males did not benefit in terms of increased progeny production by protracting copulation, female remating was delayed after long first copulations.<BR/>Conclusion: Copulation time is a trait subject to sexual conflict. Mating durations exceeding female optima serve males as a form of 'extended mate guarding': by inducing mating refractoriness in the female, a male extends the time over which its sperm is exclusively used to sire progeny and reduces the likelihood of the female being reinseminated by a competitor.

<I>Background and objectives</I> There is an urgent need to detect, assess, and reduce effects of hormonally active compounds and endocrine disrupters in aquatic systems, as reflected in national research programs like the Swiss NRP 50 "Endocrine Disruptors" and its consensus platforms. As a medium-term measure, the EU strategy on endocrine disruptors (SEC(2007)1635) uses the Endocrine Disruptor Testing and Assessment (EDTA) Task Force of the Organisation for Economic Co-operation and Development (OECD) along with other research activities. In particular the test methods of the OECD that are currently in validation or already validated may contribute to a better understanding of the extent of endocrine disruption, in particular if they are applied on environmental samples and in the context of risk-assessment strategies, for instance in waste water treatment. This article aims to give an overview and an evaluation on available and validated biological test systems for the detection of endocrine disruptive and reproductive effects in aquatic systems. Based on this a recommendation for a modular ecotoxicological test platform is given. The study focuses on test methods for sex hormone active substances.<BR/><I>Material and methods</I> On the basis of an extensive literature search and ongoing international validation efforts by the OECD for methods to detect endocrine disruptive effects, 15 biological test methods (5 <I>in vivo</I> and 10 <I>in vitro</I>) were selected. Comprising, for example, of eight OECD methods and three out of five <I>in-vitro</I> methods mentioned in the Global Water Research Coalition (GWRC) report "Tools to detect estrogenic activity in environmental waters" (Leusch 2008). Experienced users and developers were then asked to rate the test according to given relevant criteria. The resulting criteria profiles were compiled, compared, and evaluated.<BR/><I>Results</I> The methods were selected on the basis of validation status, distribution, their suitability for standardisation, and their proven sensitivity for environmental samples. We assumed that specific YES/YAS-procedures and the ER/AR Calux systems achieve the mentioned criteria. In the case that strong cytotoxicity of environmental samples affects the applicability of cellular reporter gene assays, alternatively a molecular receptor binding assay (e. g. ELRA) could be used. Additional molecular receptor binding assays are currently in validation by the OECD. Modulating effects on steroidgenesis and probably even on aromatase activity can be detected by the OECD validated H295R Steroidgenesis Assay. Its applicability for environmental samples is currently tested. As <I>in-vivo</I> methods different fish assays (e. g. Fish Screening Assay and the Zebrafish Embryo Test) were evaluated. For the detection of effects on the thyroid-associated hormone system the Amphibian Metamorphosis Assay (XEMA, for Xenopus Metamorphosis Assay) will soon be available as an OECD-Guideline. Because of trends in the international community to avoid tests with vertebrates in the future, only an optional recommendation was given for such tests. Reproduction toxicity, on the other hand, can be sensitively tested by the tests using the gastropod <I>Potamopyrgus antipodarum</I>, which, as invertebrate tests, do not require a permit to perform animal testing procedures . This test is also sensitive for many substances which are able to induce an endocrine disruption in vertebrates. Its validation is currently performed by the OECD. The applicability of the herein proposed test methods of the modular test platform for environmental-sample assessments were previously confirmed by several published scientific studies.<BR/><I>Discussion</I> We propose several test methods to be included in an application-oriented modular test platform. These tests should be suitable to efficiently indicate different mechanisms of endocrine disruption and reproduction toxicity, and may be employed in different situations according to their respective advantages. The modular test platform is able to detect impacts on the reproduction relevant effects in invertebrates, amphibians, and fishes. Furthermore the different mode of actions of estrogenic and androgenic receptor binding, steroid genesis and perhaps even the modulation of aromatase are detectable. A research report on the relevance of endocrine substances and pharmaceuticals in aquatic environments (Moltmann et al. 2007) showed that endocrine end-points of <I>in-vivo</I> tests (31 of 71 tested substances) tend to be more sensitive than general ecotoxicological end-points, such as mortality and growth. Consequently, endocrine and general-toxic effects should be detected in an integrative manner by ecotoxicological test platforms.<BR/><I>Conclusions</I> By combining literature research with a targeted query for information about the chosen test procedures it was possible to obtain a detailed overview about the current state-of-the-art of science and technology in the detection of hormone-active effects and reproduction toxicity. Ecotoxicological and regulative aspects were considered equally, and the applicability of the test procedures was evaluated. Because of the diversity of endocrine disrupting mechanisms, a modular combination of <I>in-vivo</I> and <I>in-vitro</I> methods in a joint test platform is needed to recognise and differentiate the transitions from hormone-active effects to endocrine disruption.<BR/><I>Recommendations and perspectives</I> Our study leads to a proposal of a modular ecotoxicological test platform, which offers an integrative detection of hormone-active and reproduction-relevant effects in the aquatic environment. The modular system presented here allows the switching between test modules according to the continuously developing state-of-the-art of science and technology as well as the incorporation of novel developments. Further standardisation of such methods for regulative applications is recommended.

We present a geological map, profiles and the results of a detailed structural analysis of the Early Oligocene Engi Slates southwest of the village of Engi in the Sernft Valley in canton Glarus (Switzerland). In this area, the Engi Slates are folded on a deca- to hectometer scale into tight NW-vergent folds with sharp hinges. This took place during the Plattenberg F<SUB>1</SUB> folding phase. No axial plane foliation was formed. The F<SUB>1</SUB> folds are unconformably cut-off by a 16-25° NE dipping thrust, along which Eocene marls were emplaced onto the folded Engi Slates. We refer to this thrust as Riedboden Thrust and correlate it with the base of the upper, chaotic part of the Wildflysch Nappe of Oberholzer (1942). This is a (probably tectonic) mélange of rocks from the underlying Sardona, Blattengrat and North Helvetic Flysch Units. It lies as a 5 to 100 m thick, more or less continuous nappe below the Glarus Thrust. A younger, SE-dipping tectonic foliation (Plattenberg F<SUB>2</SUB> foliation) cuts both through the folded Engi Slates, the Riedboden Thrust and the Eocene marls. This foliation is the axial plane foliation to meter-scale open F<SUB>2</SUB> folds. It developed parallel to the overturned limbs of the F<SUB>1</SUB>-folds.

The potential for reducing diarrhoea morbidity and improving the health status of children in developing countries using solar water disinfection (SODIS) has been demonstrated in past research. A baseline survey was conducted to explore the feasibility and necessity of introducing SODIS in peri-urban communities of Zimbabwe. The survey sought to establish drinking water quality in these areas and to determine the health and hygiene beliefs as well as practices related to water handling in the household. Microbiological water quality tests and personal interviews were carried out in Epworth township and Hopley farm, two peri-urban areas near the capital of Zimbabwe, Harare. These two areas are among the poorest settlements around Harare with 80% of inhabitants being informal settlers. Community meetings were held to introduce solar water disinfection prior to the survey. This was followed by administration of questionnaires, which aimed to investigate whether the community had ever heard about SODIS, whether they were practicing it, other means that were being used to treat drinking water as well as health and hygiene beliefs and practices. It was found out that most households cannot afford basic water treatment like boiling as firewood is expensive. People generally reported that the water was not palatable due to objectionable odour and taste. Microbiological water quality tests proved that drinking water was contaminated in both areas, which makes the water unsafe for drinking and shows the necessity of treatment. Although the majority of people interviewed had not heard of SODIS prior to the interview, attitudes towards its introduction were very positive and the intention to do SODIS in the future was high. Amongst the ones who had heard about SODIS before the study, usage was high. Plastic PET bottles, which were used for the SODIS experiments are currently unavailable and this has been identified as a potential hindrance to the successful implementation of SODIS.

<I>Background</I> The November 1, 1986 fire at a Sandoz Ltd. storehouse at Schweizerhalle, an industrial area near Basel, Switzerland, resulted in chemical contamination of the environment. The storehouse, which was completely destroyed by the fire, contained pesticides, solvents, dyes, and various raw and intermediate materials. The majority of the approximately 1,250 t of stored chemicals was destroyed in the fire, but large quantities were introduced into the atmosphere, into the Rhine River through runoff of the fire-fighting water, and into the soil and groundwater at the site. The chemicals discharged into the Rhine caused massive kills of benthic organisms and fish, particularly eels and salmonids. Public and private reaction to the fire and subsequent chemical spill was very strong. This happened only a few months after the Chernobyl accident and it destroyed the myth of immunity of Switzerland regarding such catastrophes.<BR/><I>Aim</I> This article reviews the damaging events of November 1986 and aims at striking stock two decades later.<BR/><I>Results and discussion</I> In the aftermath of this once-per-century accident, the aim was to obtain new knowledge for the environmental sciences and to achieve progress for water pollution control issues. The following themes are discussed: mitigation measures by the chemical industry and by the governmental authorities, activities of environmental protection organizations, chemical and biological monitoring, alert organization, ecological damages, ecotoxicological effects assessment, recovery and alteration of the river biology, return of the salmon, drinking water supplies, research programs, education of environmental scientists, and visions for the future.<BR/><I>Conclusion</I> The catastrophic pollution of the Rhine in November 1986 has triggered by the openly visible damages of the river biology that subsequently significant progress was made towards the prevention of such environmental catastrophes. The crucial risk reduction measures in the chemical industry, legal regulations and controls as well as chemical and biological monitoring of the river water quality were substantially improved. Politics and chemical industry have learned their lectures and have proceeded accordingly.<BR/><I>Recommendations</I> A drastic acute contamination, as it has happened at Schweizerhalle in 1986, is clearly recognizable by the toxic effects, which it is causing. This can lead to mitigation activities, which are positive considering a long-term perspective. However, the less obvious effects of chronic water pollution should receive more attention as well as the ongoing alteration of the biocenosis. A high water quality must be demanded for using water from the Rhine to produce drinking water. In that context, micropollutants should also be considered and particular attention should be payed to emerging contaminants.<BR/><I>Perspectives</I> The big chemical storehouse fire of 1986 had an important impact on the transboundary cooperation and has improved the willingness for international cooperation. The fire catastrophe of Schweizerhalle has triggered many activities in particular for the Rhine River. Overall, the effects are positive on the basis of a long-term perspective. The applied whole basin approach gives an example on a global basis for other river systems, which still are more heavily polluted.

The 1st Young Environmental Scientists (YES) Meeting took place in March (16–18) 2009 at the Institute for Environmental Sciences at the University of Koblenz-Landau, Landau Campus, Germany. This special students-only conference was organised under the umbrella of Society of Environmental Toxicology and Chemistry (SETAC) Europe by its Student Advisory Council (SAC). The SAC represents student members (master, diploma or Ph.D.) throughout every level of SETAC and provides additional advice, recommendations and new initiatives to the SETAC Europe Council.

Technical nonylphenol (tNP), used for industrial production of nonylphenol polyethoxylate surfactants, is a complex mixture of C<SUB>3−10</SUB>-phenols. The major components, 4-nonylphenols, are weak endocrine disruptors whose estrogenicities vary according to the structure of the branched nonyl group. Thus, accurate risk assessment requires isomer-specific determination of 4-NPs. Comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GC × GC/ToFMS) was used to characterize tNP samples obtained from seven commercial suppliers. Under optimal chromatographic conditions, 153−204 alkylphenol peaks, 59−66 of which were identified as 4-NPs, were detected. The 4-NPs comprised 86−94% of tNP, with 2-NPs and decylphenols making up 2−9% and 2−5%, respectively. The tNP products were analyzed for eight synthetic 4-NP isomers, and results were compared with published data based on GC/MS analysis. Significant differences were found among the products and between two samples from a single supplier. The enhanced resolution of GC × GC coupled with fast mass spectral data acquisition by ToFMS facilitated identification of all major 4-NP isomers and a number of previously unrecognized components. Analysis of tNP altered by the bacterium, <I>Sphingobium xenophagum</I> Bayram, revealed several persistent 4-NPs whose structures and estrogenicities are presently unknown. The potential of this technology for isomer-specific determination of 4-NP isomers in environmental matrices is demonstrated using samples of wastewater-contaminated groundwater and municipal wastewater.

A wide variety of antibacterial compounds is rapidly oxidized by O<SUB>3</SUB> and hydroxyl radical (<SUP><B>·</B></SUP>OH) during aqueous ozonation. Quantitative microbiological assays have been developed here or adapted from existing methods and utilized to measure the resulting changes in antibacterial potencies during O<SUB>3</SUB> and <SUP><B>·</B></SUP>OH treatment of 13 antibacterial molecules (roxithromycin, azithromycin, tylosin, ciprofloxacin, enrofloxacin, penicillin G, cephalexin, sulfamethoxazole, trimethoprim, lincomycin, tetracycline, vancomycin, and amikacin) from 9 structural classes (macrolides, fluoroquinolones, β-lactams, sulfonamides, dihydrofolate reductase inhibitors, lincosamides, tetracyclines, glycopeptides, and aminoglycosides), as well as the biocide triclosan. Potency measurements were determined from dose−response relationships obtained by exposing <I>Escherichia coli</I> or <I>Bacillus subtilis</I> reference strains to treated samples of each antibacterial compound via broth micro- or macrodilution assays and related to the measured residual concentrations of parent antibacterial in each sample. Data obtained from these experiments show that O<SUB>3</SUB> and <SUP><B>·</B></SUP>OH reactions lead in nearly all cases to stoichiometric elimination of antibacterial activity (i.e., loss of 1 mole equivalent of potency permole of parent compound consumed). The β-lactams penicillin G (PG) and cephalexin (CP) represent the only clear exceptions, as bioassay measurements indicate that biologically active products may be formed in the reactions of these two compounds with both O<SUB>3</SUB> and <SUP><B>·</B></SUP>OH. The active product(s) generated in the direct reaction of O<SUB>3</SUB> with PG appear(s) to be recalcitrant to further transformation by O<SUB>3</SUB>, though any biologically active products formed in the reactions of CP with O<SUB>3</SUB>, or of either PG or CP with <SUP><B>·</B></SUP>OH, are apparently deactivated by further reactions with O<SUB>3</SUB> or <SUP><B>·</B></SUP>OH, respectively. Thus, with few exceptions, it can be expected that municipal wastewater ozonation will generally yield sufficient structural modification of antibacterial molecules to eliminate their antibacterial activities, whether oxidation results from selective reactions with O<SUB>3</SUB> or from relatively nonselective reactions with incidentally produced <SUP><B>·</B></SUP>OH.

<em>Background and aim</em> Despite intensive and continuous stocking and improvement of water quality since the 1970s, fish populations, especially those of the grayling (<em>Thymallus thymallus</em>), have declined over the last two decades in the upper Danube River (Germany). In order to assess 1) possible links between molecular/biochemical responses and ecologically relevant effects, and 2) if ecotoxicological effects might be related to the decline in fish catches in the upper Danube river, sediment samples and fish were collected at different locations and analyzed using a weight-of-evidence (WOE) approach with several lines of evidence. The objective of the presentation is to introduce the conceptual framework and to review results of the ongoing study. As previously addressed by Chapman and Hollert (2006) a variety of lines of evidence can be used in WOE studies. Briefly, 1) a comprehensive battery of acute and mechanism-specific bioassays was used to characterize the ecotoxicological hazard potential. 2) Histopathological investigations and the micronucleus assay with erythrocytes were applied, analyzing <em>in situ</em> parameters. 3) Diversity and abundance of benthic macroinvertebrates and fish as well as 4) persistent organic pollutants, endocrine disrupting substances, limnochemical parameters and the concentration of heavy metals were recorded. To identify organic contaminants a spotential causes of sediment toxicity assays, 5) effect directed analysis was applied.

The Swiss Federal Railways (SFR) use glyphosate as the only herbicide for the chemical weed control on railway tracks. After the application on the railroad embankment the herbicide can be partly transported with the rainfall to the aquatic environment.<BR/>In order to assess the potential environmental pollution glyphosate and its main degradation product aminomethylphosphonic acid (AMPA) were analysed in selected drainage water of the railroad embankment from all over the railway system. The results were compared with studies in other European countries. Furthermore, the time-dependent concentration dynamics during one rain event was investigated at one selected sampling site.

Perfluorinated compounds are emerging persistent organic pollutants. Wastewater treatment plants are reported to be one of their primary sources. However; a standard analytical method for sludge samples has not been set up. A novel and rapid analytical method based on the liquid extraction; followed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was set up for 7 perfluorocarboxylic acids (PFCAs) and their precursors, 6: 2 and 8: 2 unsaturated flourotelomer carboxylic acids (FTUCAs), and 2 perfluoroalkyl sulfonates vPFASs) and their precursors; 5 derivates of sulfonamide in sludge. The parameters of methanol extraction, including pH, sonication temperature and time, and eluent volume were optimized. The extraction method was optimized as neutral extraction under sonication at 40 °C for 10 min, and it was successfully used for the analysis of perfluorinated compounds in the sludge samples. The linear calibration curves were obtained in the ranges of 0. 1 - 20 μg/L for PFCAs and 6:2/8:2 FTUCA and 0. 25 - 50 μg/L for PFASs and their precusors with linear correlation coefficients larger than 0. 99. The recoveries of the target compounds ranged from 74% to 141% (except for FTUCAs) and the limits of quantification ranged from 0. 6 to 30 μg/kg (dry weight). The use of internal standards can well correct the ion suppression (or enhancement) induced by co-eluting components present in the sample extracts, and improve the quantitative accuracy.

Spontaneous mutations are not randomly distributed throughout a genome. Although mutation hotspots are found on genomes of a variety of species, mechanisms that generate the hotspots are not well understood. In eukaryotes, strong association between a regional nucleotide substitution rate and insertions/deletions (indels) was reported in a previous study, and the “indel-induced mutation” hypothesis was proposed. However, it is unknown whether the association exists even in prokaryote genomes. In this study, we conducted a systematic survey for the association in 262 complete genomes from 73 bacterial species. In these bacteria, the level of nucleotide diversity was negatively correlated with the distance from the closest indel, which is consistent with the eukaryote data. The same pattern was observed even after excluding noncoding sequences, indicating that the difference in functional constraints among genomic regions is not a primary cause of the correlation. In addition, the increase of nucleotide substitution rate was detected disproportionally on a lineage carrying a derived indel mutation, confirming the indel-nucleotide diversity association in the bacterial genomes. In some cases, the level of nucleotide diversity was more than 100 times higher in regions close to indels than in distant regions. Although further understanding of the molecular mechanism is required to test the hypothesis, these results suggest that the same mechanism for the indel–nucleotide diversity associations might exist in eukaryotes and prokaryotes and play an important role in molecular evolution.

We employed environmental tracers (<SUP>3</SUP>H-<SUP>3</SUP>He, noble gases, stable isotopes <SUP>18</SUP>O and <SUP>2</SUP>H) to study groundwater recharge and residence times in the strongly exploited North China Plain aquifer system in the area of Shijiazhuang, the capital of the Hebei province. Groundwater in the unconfined parts of the piedmont plain contains tritium down to depths of about 100 m and exhibits <SUP>3</SUP>H-<SUP>3</SUP>He ages of less than 40 years. <SUP>3</SUP>H-<SUP>3</SUP>He ages correlate well with sampling depth but less so with distance along a transect from the mountains in the west through the recharge area in the piedmont plain, indicating a minor role of lateral inflow compared to spatially distributed recharge. The increase of groundwater age with increasing thickness of the saturated zone combined with the steady groundwater table descent over the last decades implies an effective recharge rate of around 0.3 m/yr, mostly due to infiltration of precipitation and irrigation water. Despite the recycling of irrigation water, a water balance deficit remains, causing depletion of the aquifers. Anthropogenic modifications of the natural recharge regime appear to be reflected by a trend of increasing stable isotope ratios in groundwater of the last decades.

The principle of subsurface or in situ iron and arsenic removal is that aerated water is periodically injected into an anoxic aquifer through a tube well, displacing groundwater containing Fe(II). An oxidation zone is created around the tube well where Fe(II) is oxidised. The freshly formed iron hydroxide surfaces provide new sorption sites for soluble Fe(II) and arsenic. The system's efficiency is determined based on the ratio between abstracted volume with reduced iron/arsenic concentrations (V) and the injected volume (V<I><SUB>i</SUB></I>). In the field study presented in this paper, the small-scale application of this technology was investigated in rural Bangladesh. It was found that at small injection volumes (<1 m<SUP>3</SUP>) iron removal was successful and became more effective with every successive cycle. For arsenic, however, the system did not prove to be very effective yet. Arsenic retardation was only limited and breakthrough of 10 mg/L (WHO guideline) was observed before V/V<I><SUB>i</SUB></I>=1, which corresponds to arrival of groundwater at the well. Possible explanations for insufficient arsenic adsorption are the short contact times within the oxidation zone, and the presence of competing anions, like phosphate.

Flow cytometry (FCM) is rapidly becoming an essential tool in the field of aquatic microbiology. It provides opportunities for microbial analysis at both the community and single-cell levels. Compared with other techniques, FCM facilitates rapid data acquisition and multi-parameter analysis, leading to increased popularity and widespread applications. Here, we briefly review the current status of FCM in the field of microbiology, focusing on its recent applications in aquatic microbiology. These developments range from straightforward total cell counts to community structure analysis, and further extend to physiological analysis at a single-cell level. Exciting future prospects for the applications of FCM in aquatic microbiology are also discussed based on current scientific and practical needs.

The degree to which a water sample can potentially support the growth of human pathogens was evaluated. For this purpose, a pathogen growth potential (PGP) bioassay was developed based on the principles of conventional assimilable organic carbon (AOC) determination, but using pure cultures of selected pathogenic bacteria (<em>Escherichia coli</em> O157, <em>Vibrio cholerae</em>, or <em>Pseudomonas aeruginosa</em>) as the inoculum. We evaluated 19 water samples collected after different treatment steps from two drinking water production plants and a wastewater treatment plant and from ozone-treated river water. Each pathogen was batch grown to stationary phase in sterile water samples, and the concentration of cells produced was measured using flow cytometry. In addition, the fraction of AOC consumed by each pathogen was estimated. Pathogen growth did not correlate with dissolved organic carbon (DOC) concentration and correlated only weakly with the concentration of AOC. Furthermore, the three pathogens never grew to the same final concentration in any water sample, and the relative ratio of the cultures to each other was unique in each sample. These results suggest that the extent of pathogen growth is affected not only by the concentration but also by the composition of AOC. Through this bioassay, PGP can be included as a parameter in water treatment system design, control, and operation. Additionally, a multilevel concept that integrates the results from the bioassay into the bigger framework of pathogen growth in water is discussed. The proposed approach provides a first step for including pathogen growth into microbial risk assessment.

Sexual selection by female mating preference for male nuptial coloration has been suggested as a driving force in the rapid speciation of Lake Victoria cichlid fish. This process could have been facilitated or accelerated by genetic associations between female preference loci and male coloration loci. Preferences, as well as coloration, are heritable traits and are probably determined by more than one gene. However, little is known about potential genetic associations between these traits. In turbid water, we found a population that is variable in male nuptial coloration from blue to yellow to red. Males at the extreme ends of the phenotype distribution resemble a reproductively isolated species pair in clear water that has diverged into one species with blue-grey males and one species with bright red males. Females of the turbid water population vary in mating preference coinciding with the male phenotype distribution. For the current study, these females were mated to blue males. We measured the coloration of the sires and male offspring. Parents-offspring regression showed that the sires did not affect male offspring coloration, which confirms earlier findings that the blue species breeds true. In contrast, male offspring coloration was determined by the identity of the dams, which suggests that there is heritable variation in male color genes between females. However, we found that mating preferences of the dams were not correlated with male offspring coloration. Thus, there is no evidence for strong genetic linkage between mating preference and the preferred trait in this population.

A key parameter used in the assessment of bank filtration is the travel time of the infiltrated river water during the passage through groundwater. We analyze time series of electrical conductivity (EC) in the river and adjacent groundwater observation wells to investigate travel times of young hyporheic groundwater in adjoining channelized and restored sections of River Thur in North-East Switzerland. To quantify mixing ratios and mean residence times we perform cross-correlation analysis and non-parametric deconvolution of the EC time series. Measurements of radon-222 in the groundwater samples validate the calculated residence times. A simple relationship between travel time and distance to the river has not been observed. Therefore, we speculate that the lateral position and depth of the thalweg as well as the type of bank stabilization might control the infiltration processes in losing rivers. Diurnal oscillations of EC observed in the river and in nearby observation wells facilitate analyzing the temporal variation of infiltration. The diurnal oscillations are particularly pronounced in low flow situations, while the overall EC signal is dominated by individual high-flow events. Differences in travel times derived from diurnal and overall EC signals thus reflect different infiltration regimes.

Current advances in genetic analysis are opening up our knowledge of the genetics of species differences, but challenges remain, particularly for out-bred natural populations. We constructed a microsatellite-based linkage map for two out-bred lines of <I>Drosophila montana</I> derived from divergent populations by taking advantage of the <I>Drosophila virilis</I> genome and available cytological maps of both species. Although the placement of markers was quite consistent with cytological predictions, the map indicated large heterogeneity in recombination rates along chromosomes. We also performed a quantitative trait locus (QTL) analysis on a courtship song character (carrier frequency), which differs between populations and is subject to strong sexual selection. Linkage mapping yielded two significant QTLs, which explained 3% and 14% of the variation in carrier frequency, respectively. Interestingly, as in other recent studies of traits which can influence speciation, the strongest QTL mapped to a genomic region partly covered by an inversion polymorphism.

The virtual water strategy which advocates importing water intensive products and exporting products with low water intensity is gradually accepted as one of the options for solving water crisis in severely water scarce regions. However, if we count the virtual water embodied in imported products as the water saved for a region, we might overestimate the saving by including the virtual water that is later re-exported in association with the proceeded products made from the originally imported products. This problem can be avoided by accounting for the saved water through calculating water footprint (WF) in domestic final consumptive products. In this paper, an input-output analysis (IOA) based on the water footprint accounting framework is built to account for WF and virtual water trade of final consumptive products in the water stressed Haihe River basin in China for the year 1997, 2000, and 2002. The input-output transaction tables of the three years are constructed. The results show WF of 46.57, 44.52, and 42.71 billion m(3) for the three years, respectively. These volumes are higher than the water used directly in the corresponding years in the basin. A WF intensity (WFI) indicator is then used to assess if the economic activities in the basin are consistent with the virtual water strategy. The temporal change of the WFI is also decomposed by the index number analysis method. The results showed that the basin was silently importing virtual water through the trade of raw and processed food commodities under the background of the whole economic circulation.

In Switzerland, we are also expecting an increase in biogas utilisation in future for generating current and heat or biomethane (as a substitute for natural gas). The factors below are seen as being pivotal for the coming development in the technology field of biogas [1]: The availability of highenergy fermentable biomass, the political framework, advanced development of technologies and the prices for energy and nutrients. This article recommends adding to this list an outspoken debate on operator models for an analysis of future biogas utilisation.