Aerobe Phosphorylierung unter dem Einfluß von K+, Na+, Rb+ und NH 4 +

The Science of Nature -     

Polychlorinated biphenyls, organochlorine pesticides and polycyclic aromatic hydrocarbons in a one-off global survey of bivalves

During the Danish Galathea 3 expedition, bivalve samples were collected at the Faroe Islands, Greenland, Ghana, South Africa, Australia, Solomon Islands, New Zealand, Chile, US Virgin Islands, Boston, Newfoundland and Shetland Islands and analysed for organochlorines and PAHs. Concentration differences of up to three orders of magnitude were observed, with the highest concentrations at Boston harbour (SPCB 338 ng g(-1) dw, ΣSPAH 5966 ng g(-1) dw) and the Sydney estuary (ΣSPCB 282 ng g(-1) dw, SPAH 1453 ng g(-1) dw). Local impacts were also found for the Greenland capital Nuuk in terms of PCB and PAH levels, while other Greenland samples came closest to representing PAH background levels. Several locations had undetectable organochlorine levels, including Hobart and Chile, which had the lowest SPAH concentrations (<200 ng g(-1) dw). It was possible to group the stations according to their pyrogenic/petrogenic influence using Principal Component Analyses, and indications of petroleum sources were found at Nuuk.     

Utility assessment of a map-based online geo-collaboration tool

Spatial group decision-making processes often include both informal and analytical components. Discussions among stakeholders or planning experts are an example of an informal component. When participants discuss spatial planning projects they typically express concerns and comments by pointing to places on a map. The Argumentation Map model provides a conceptual basis for collaborative tools that enable explicit linkages of arguments to the places to which they refer. These tools allow for the input of explicitly geo-referenced arguments as well as the visual access to arguments through a map interface. In this paper, we will review previous utility studies in geo-collaboration and evaluate a case study of a Web-based Argumentation Map application. The case study was conducted in the summer of 2005 when student participants discussed planning issues on the University of Toronto St. George campus. During a one-week unmoderated discussion phase, 11 participants wrote 60 comments on issues such as safety, facilities, parking, and building aesthetics. By measuring the participants' use of geographic references, we draw conclusions on how well the software tool supported the potential of the underlying concept. This research aims to contribute to a scientific approach to geo-collaboration in which the engineering of novel spatial decision support methods is complemented by a critical assessment of their utility in controlled, realistic experiments.     

über die Notwendigkeit der wirkungsorientierten Analytik in einer umfassenden Wasserforschung

Ohne Zusammenfassung Verantwortliche Herausgeber: Jan Schwarzbauer · Peter Heininger · Evelyn Claus

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Effect directed analysis and mixture effects of estrogenic compounds in a sediment of the river Elbe

INTRODUCTION: Endocrine disrupting chemicals (EDCs) are present in the environment and can have serious effects on humans and wildlife. For the establishment of environmental quality guidelines and regulation of EDCs, a better understanding and knowledge of the occurrence and the behavior of environmental EDCs is necessary. The aim of the present study was to comprehensively identify substances that are responsible for the estrogenic effect of an environmental sediment sample taken from the river Elbe/Germany. DISCUSSION: The estrogenic effect of the organic sediment extract was determined using the yeast-estrogen-screen (YES). The sample was fractionated by liquid chromatography (LC) for effect directed analysis. The composition of estrogen-active fractions was further investigated by gas chromatography-mass spectrometry and high-resolution LC-MS analysis. The composition of the environmental sample was rebuilt with pure compounds in order to assess the partition of estrogenic activity caused by the identified compounds. The organic sediment extract showed an estrogenic potential of 1.9?±?0.4 ng/g ethinylestradiol equivalents in the sediment. The most prominent contaminants with an estrogenic potential were 17β-estradiol, estrone, and 4-iso-nonylphenols, but other xenoestrogens like bisphenol A and stigmasterol could be found as well. A rebuild of the sample was measured in the YES in order to investigate mixture effects. About 67 % of the observed estrogenic effect in the sediment extract could be explained by a mixture which contained all identified compounds. Chlorophene (o-benzyl-p-chlorophenol)-a widely used antiseptic that was also identified in the sediment extract-has xenoestrogenic properties in the YES that are in the range of other xenoestrogens like 4-n-nonylphenol. This is the first report on chlorophene acting as a xenoestrogen.     

Quantitative PCR analysis of molds in the dust from homes of asthmatic children in North Carolina

The vacuum bag (VB) dust from the homes of 19 asthmatic children in North Carolina (NC) was analyzed by mold specific quantitative PCR. These results were compared to the analysis of the VB dust from 176 homes in the HUD, American Healthy Home Survey of homes in the US. The Environmental Relative Moldiness Index (ERMI) was calculated for each of the homes. The mean and standard deviation (SD) of the ERMI values in the homes of the NC asthmatic children was 16.4 (6.77), compared to the HUD survey VB ERMI value mean and SD of 11.2 (6.72), and was significantly greater (t-test, p = 0.003) in the NC asthmatic children's homes. The molds Chaetomium globosum, Aspergillus fumigatus, and the Eurotium Group were the primary species in the NC homes of asthmatics, making the ERMI values significantly higher (p < 0.02 for each). Vacuum bag dust analysis may be a useful method for estimating the mold burden in a home.     

Kinetics of CO2 absorption in aqueous ammonia solution

The kinetics of CO₂ absorption in unloaded aqueous ammonia solution were measured using a string of discs contactor with the aqueous ammonia concentrations ranging 0.9–5.4 kmol/m³ and temperatures ranging 298.3–321.9 K. The reaction rates strongly increase with the concentration and less strongly with temperature. Both the termolecular and zwitterion models were applied in this study as amine solutions. The parameters for both of the models were interpreted. The kinetic rate constants for CO₂ absorption in aqueous ammonia were compared with those for other amines and were found to be around 1/10 that for monoethanolamine. The fitting results for the termolecular mechanism seem more robust than those for the zwitterion mechanism from a statistical perspective.     

A metabolomics based approach to assessing the toxicity of the polyaromatic hydrocarbon pyrene to the earthworm Lumbricus rubellus

The biochemical response of the earthworm Lumbricus rubellus to pyrene exposure was assessed using 1H nuclear magnetic resonance (NMR) spectroscopy, gas chromatography mass spectrometry (GC-MS) and pattern recognition techniques. Both analytical methods enabled the establishment of reproducible metabolic profiles. NMR analysis identified a total of 32 metabolites while GC-MS identified 51. The results demonstrate that not only is pyrene toxic to L. rubellus, but that alterations in its normal metabolic profile could be observed even when individuals were exposed to concentrations of 40mg kg(-1): a pollution level that is both below the concentration previously found to significantly reduce reproduction and within the range of polycyclic aromatic hydrocarbons (PAHs) found on some contaminated sites. Pyrene was found to cause a dose dependant decrease in lactate and the concentrations of the saturated fatty acids tetradecanoic, hexadecanoic and octadecanoic acid and an increase in production of the amino acids alanine, leucine, valine, isoleucine, lysine, tyrosine and methionine. It is proposed that this indicates impaired glucose metabolism, with an associated increase in fatty acid metabolism and changes in TCA cycle intermediates. This study demonstrates the versatility of metabolomics as a tool to monitor toxicity in the environment as opposed to utilising model species studied in a laboratory setting. Since it is a non-carcinogenic PAH, we propose that the metabolic changes observed in worms may reflect the non-specific toxic effects of pyrene as a typical, non-polar organic compound.     

热解技术在有机固废能源化清洁利用方面的应用潜力分析

热解技术在有机固废能源化清洁利用方面具有巨大的应用潜力.通过对热解技术的工作原理、适用范围、工艺系统与设备等的阐述及其能量转化、产物分析,吸取国外成功经验,着重以污泥为例,论述了热解技术在有机固废处置及综合利用方面的优势,并建设性地提出了3种热解技术应用模式以及国产化应用热解技术的发展规划思路.