Polybrominated diphenyl ethers in whitefish from Swiss lakes and farmed rainbow trout

A method for trace analysis of polybrominated diphenyl ethers (PBDE) in fish based on gas chromatography/electron ionization high resolution mass spectrometry (GC/EI-HRMS) was developed, and levels of PBDE were determined in whitefish (Coregonus sp.) from eight Swiss lakes and in rainbow trout (Oncorhynchus mykiss) from four Swiss fish farms. PBDE concentrations (sum of PBDE congeners BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154, and BDE-183) in filet from whitefish between 36 and 165 ng/g lipid weight (lw) were found, corresponding to wet weight (ww) concentrations of 1.6-7.4 ng/gww. PBDE contents in filet from farmed rainbow trout were significantly lower than in wild whitefish (12-24 ng/glw, 0.74-1.3 ng/gww), and the PBDE congener patterns were different for both species (a higher BDE-47 to BDE-99 ratio for farmed rainbow trout compared to wild whitefish was found). Whitefish PBDE levels [ng/glw] correlate better with the surface/volume ratio of the respective lakes (r(2)=0.70) than with other lake properties such as catchment area (size or number of inhabitants) or residence time, suggesting atmospheric deposition as an input pathway for PBDE. Based on an average daily consumption of 20 g whitefish (Switzerland) with a PBDE content of 7.4 ng/gww (highest PBDE concentration detected in this study), a maximum daily intake of 0.15 microg PBDE was estimated (0.026 microg/day for farmed trout). This number corresponds to the lower end of the estimate for the total PBDE intake of the Nordic consumer of 0.2-0.7 microg/day.     

Detecting general plant functional type responses in fragmented landscapes using spatially-explicit simulations

Habitat loss and increasing landscape fragmentation are known to be key forces driving the ongoing loss of plant species diversity. While the combined effects of increasing isolation and decreasing population size have been studied intensively; it is less understood how plant population performance in heterogeneous landscapes is affected by changes in fragmentation alone.     

Finger and hand protection on circular table and panel saws

Several hundred accidents involving the use of circular saws and resulting in injury, to hands or fingers occur each year in Germany.In the presented project, new approaches for the prevention of hand injuries and for the contactless detection of fingers are being investigated for comprehensive protection on circular saws. The basic principles can be applied to other machines with manual loading and/or unloading. This paper describes several principles to distinct human skin and wood and a safety guard that prevents touching the rotating blade. In a first approach a reliable protective device with functional diversity has been developed using a passive infrared sensor in combination with a capacitive field sensor. Second the distinction between skin and wood or other material is done by dedicated kind of spectral analysis in the near infrared region. With a kind of light curtain the intrusion into the dangerous zone near the blade can be prevented.The safety guard protects the operator’s hand within 50 ms. The forces of the protective system peak at no more than 120 N. We are presenting a complete strategy for such different tasks as cutting wedges, stopped cutting and hidden cutting, which have a very high odds ratio.     

Nature Documentaries,Connectedness to Nature,and Pro-environmental Behavior

We investigate the effects of nature documentaries on pro-environmental cognition and behavior. Of central interest is the concept of connectedness to nature, which describes an individual's sense of being connected to nature. Based on previous research showing that a direct nature experience in zoos can increase connectedness to nature, we questioned whether watching a nature documentary could increase connectedness to nature and pro-environmental behavior. An experiment using one control group (watching a documentary about Einstein's theory of relativity) and one treatment group (watching a nature documentary) revealed that a mediated nature experience is not sufficient to elicit an increase in connectedness to nature. However, we found that exposure increased actual donation behavior for animal and environmental protection organizations. It is important to note that nature documentary exposure increased pro-environmental donation behavior only in those already having a strong sense of connectedness. We discuss real-world implications for donation-accepting, non-profit organizations.     

A High‐Resolution National‐Scale Hydrologic Forecast System from a Global Ensemble Land Surface Model

Warning systems with the ability to predict floods several days in advance have the potential to benefit tens of millions of people. Accordingly, large‐scale streamflow prediction systems such as the Advanced Hydrologic Prediction Service or the Global Flood Awareness System are limited to coarse resolutions. This article presents a method for routing global runoff ensemble forecasts and global historical runoff generated by the European Centre for Medium‐Range Weather Forecasts model using the Routing Application for Parallel computatIon of Discharge to produce high spatial resolution 15‐day stream forecasts, approximate recurrence intervals, and warning points at locations where streamflow is predicted to exceed the recurrence interval thresholds. The processing method involves distributing the computations using computer clusters to facilitate processing of large watersheds with high‐density stream networks. In addition, the Streamflow Prediction Tool web application was developed for visualizing analyzed results at both the regional level and at the reach level of high‐density stream networks. The application formed part of the base hydrologic forecasting service available to the National Flood Interoperability Experiment and can potentially transform the nation's forecast ability by incorporating ensemble predictions at the nearly 2.7 million reaches of the National Hydrography Plus Version 2 Dataset into the national forecasting system.     

Stereochemistry of LinB-catalyzed biotransformation of δ-HBCD to 1R,2R,5S,6R,9R,10S-pentabromocyclododecanol

The haloalkane dehalogenase LinB from Sphingobium indicum B90A converts β-hexachlorocyclohexane (β-HCH), the most persistent HCH stereoisomer, to mono- and dihydroxylated metabolites. Recently, we reported that LinB also transforms α-, β- and γ-hexabromocyclododecanes (HBCDs), which are structurally related to HCHs. Here, we show that LinB catalyzes the hydroxylation of δ-HBCD to two pentabromocyclododecanols (PBCDOHs) and two tetrabromocyclododecadiols (TBCDDOHs). The stereochemistry of this enzymatic transformation was deduced from XRD crystal structure data of the substrate δ-HBCD and α₂-PBCDOH, one of the biotransformation products. Five stereocenters of δ-HBCD are unchanged but the one at C6 is converted to an alcohol with inversion from S- to R-configuration in a nucleophilic, S_N2-like substitution reaction. Only α₂-PBCDOH with the 1R,2R,5S,6R,9R,10S-configuration is obtained but not its enantiomer. With only two of the 64 PBCDOHs formed, these transformations indeed are regio- and stereoselective. A conformational analysis revealed that the triple-turn motive, which is predominant in δ-HBCD and in several other HBCD stereoisomers, is also found in the product. This shows that LinB preferentially converted reactive bromine atoms but not those in the conserved triple-turn motive. The widespread contamination with HCHs triggered the bacterial evolution of dehalogenases which acquired the ability to convert these pollutants and their metabolites. We here demonstrate that LinB of S. indicum also transforms HBCDs regio- and stereoselectively following a similar mechanism.     

Denitrification in the river estuaries of the northern Baltic Sea

Estuaries have been suggested to have an important role in reducing the nitrogen load transported to the sea. We measured denitrification rates in six estuaries of the northern Baltic Sea. Four of them were river mouths in the Bothnian Bay (northern Gulf of Bothnia), and two were estuary bays, one in the Archipelago Sea (southern Gulf of Bothnia) and the other in the Gulf of Finland. Denitrification rates in the four river mouths varied between 330 and 905 micromol N m(-2) d(-1). The estuary bays at the Archipelago Sea and the Gulf of Bothnia had denitrification rates from 90 micromol N m(-2) d(-1) to 910 micromol N m(-2) d(-1) and from 230 micromol N m(-2) d(-1) to 320 micromol N m(-2) d(-1), respectively. Denitrification removed 3.6-9.0% of the total nitrogen loading in the river mouths and in the estuary bay in the Gulf of Finland, where the residence times were short. In the estuary bay with a long residence time, in the Archipelago Sea, up to 4.5% of nitrate loading and 19% of nitrogen loading were removed before entering the sea. According to our results, the sediments of the fast-flowing rivers and the estuary areas with short residence times have a limited capacity to reduce the nitrogen load to the Baltic Sea.     

Crystal structure analysis of enantiomerically pure (+) and (-) beta-hexabromocyclododecanes

The molecular structures of individual HBCD stereoisomers are not elucidated yet. Recently, we isolated 8 of the 16 possible stereoisomers from a technical HBCD mixture and tentatively assigned their relative configurations. Herein we report on the isolation of enantiomerically pure (+) and (-) beta-HBCDs, both obtained from preparative chiral-phase liquid chromatography, and we present their absolute configurations determined from X-ray diffraction analysis. The absolute configuration of (+) beta-HBCD was found to be (1S,2S,5S,6R,9S,10R), while the one of (-) beta-HBCD was assigned to (1R,2R,5R,6S,9R,10S). The given structural information allows, for the first time, the unambiguous identification of these two important HBCD stereoisomers, which are typically found in technical products at proportions of about 3-5% for each enantiomer.     

Persistent organic pollutants, brominated flame retardants and synthetic musks in fish from remote alpine lakes in Switzerland

Remote alpine lakes do not receive any direct aquatic inputs from anthropogenic activities. Therefore, these ecosystems may receive persistent organic compounds (POPs) by direct atmospheric deposition, only. Consequently, fish dwelling in these ecosystems represent an excellent indicator for the long-term atmospheric input of bioaccumulating and persistent contaminants. In the present study, fish from seven remote alpine lakes, located between 2062 and 2637 m above sea level in south eastern Switzerland (Grisons), were investigated. Lipid-based fish tissue concentrations of pesticides including dichlorodiphenyltrichloroethane (DDT) and its transformation products (2,4'-DDT, 4,4'-DDT, 2,4'-dichlorodiphenyldichloroethane (DDD), 4,4'-DDD, 2,4'-dichlorodiphenyldichloroethene (DDE), 4,4'-DDE), as well as dieldrin, heptachlor exo-epoxide (HPEX), hexachlorobenzene (HCB), hexachlorocyclohexanes (HCH), polychlorinated biphenyls (PCB), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F), and polybrominated diphenyl ethers (PBDE) were measured. In addition, seven synthetic musk compounds (Crysolide (ADBI), Phantolide (AHMI), Fixolide (AHTN), Traseolide (ATII), Galaxolide (HHCB), musk ketone (MK), and musk xylene (MX)) were determined. Concentrations of PCB, PCDD/F, and PBDE were in the same range as in fish from the major lakes situated in the Swiss plateau, indicating mainly atmospheric input of these persistent compounds. In contrast, concentrations of synthetic musks which are used as fragrances in laundry detergents and cosmetic products were distinctly lower than concentrations in fish from Swiss plateau lakes which receive inputs from waste water treatment plants.