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1.
We have earlier shown that radio frequency electromagnetic fields can cause significant leakage of albumin through the blood–brain barrier of exposed rats as compared to non-exposed rats, and also significant neuronal damage in rat brains several weeks after a 2 h exposure to a mobile phone, at 915 MHz with a global system for mobile communications (GSM) frequency modulation, at whole-body specific absorption rate values (SAR) of 200, 20, 2, and 0.2 mW/kg. We have now studied whether 6 h of exposure to the radiation from a GSM mobile test phone at 1,800 MHz (at a whole-body SAR-value of 13 mW/kg, corresponding to a brain SAR-value of 30 mW/kg) has an effect upon the gene expression pattern in rat brain cortex and hippocampus—areas where we have observed albumin leakage from capillaries into neurons and neuronal damage. Microarray analysis of 31,099 rat genes, including splicing variants, was performed in cortex and hippocampus of 8 Fischer 344 rats, 4 animals exposed to global system for mobile communications electromagnetic fields for 6 h in an anechoic chamber, one rat at a time, and 4 controls kept as long in the same anechoic chamber without exposure, also in this case one rat at a time. Gene ontology analysis (using the gene ontology categories biological processes, molecular functions, and cell components) of the differentially expressed genes of the exposed animals versus the control group revealed the following highly significant altered gene categories in both cortex and hippocampus: extracellular region, signal transducer activity, intrinsic to membrane, and integral to membrane. The fact that most of these categories are connected with membrane functions may have a relation to our earlier observation of albumin transport through brain capillaries.  相似文献   
2.
Denmark has a long tradition of monitoring the aquatic environment. Previous monitoring has mainly focused on loss of nutrients and subsequent impacts on the biological structure in lakes and coastal areas. However, as part of the third Action Plan for the Aquatic Environment more emphasis has been put on stream ecology. The present paper describes background, strategy and content of the new NOVANA stream programme, which will run for the period 2004–2009. The new programme will encompass more than 800 stations covering all stream types in Denmark and monitoring will include three biological quality elements (macrophytes, macroinvertebrates and fish) as well as physico-chemical features and hydromorphological elements. In addition, the new programme integrates monitoring of elements both in the stream itself and in the riparian zone. Compliance with important European Commission Directives such as the Water Framework Directive and the Habitat Directive is discussed.  相似文献   
3.
The concept of sustainability transitions has become increasingly prominent in academic and policy discourses during recent decades, but the importance of the link between knowledge-producing epistemic practices and urban governance has been underappreciated in this discourse. Based on a case study of cycling in Copenhagen between 1900 and 2015, and drawing upon a governmentality-inspired analytical framework, this research demonstrates that transformative governance may be initiated by epistemic practices that render urban systems visible in other ways. Urban cycling has been reconstructed over time in Copenhagen as a traffic safety ‘problem’, a component of the experiential and liveable city, and a health-producing (and hence economically valuable) regional transport mode. The research findings emphasise that epistemic practices can provide a powerful stimulus for creating changes in urban governance. The results also provide support for initiatives to broaden the terms of academic debate on sustainability transitions.  相似文献   
4.
For several decades, perfluorooctane sulfonate (PFOS) has widely been used as a fluorinated surfactant in aqueous film forming foams used as hydrocarbon fuel fire extinguishers. Due to concerns regarding its environmental persistence and toxicological effects, PFOS has recently been replaced by novel fluorinated surfactants such as Forafac®1157, developed by the DuPont company. The major component of Forafac®1157 is a 6:2 fluorotelomer sulfonamide alkylbetaine (6:2 FTAB), and a link between the trade name and the exact chemical structure is presented here to the scientific community for the first time. In the present work, the structure of the 6:2 FTAB was elucidated by 1H, 13C and 19F nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry. Moreover, its major metabolites from blue mussel (Mytilus edulis) and turbot (Scophthalmus maximus) and its photolytic transformation products were identified. Contrary to what has earlier been observed for PFOS, the 6:2 FTAB was extensively metabolized by blue mussel and turbot exposed to Forafac®1157. The major metabolite was a deacetylated betaine species, from which mono- and di-demethylated metabolites also were formed. Another abundant metabolite was the 6:2 fluorotelomer sulfonamide. In another experiment, Forafac®1157 was subjected to UV-light induced photolysis. The experimental conditions aimed to simulate Arctic conditions and the deacetylated species was again the primary transformation product of 6:2 FTAB. A 6:2 fluorotelomer sulfonamide was also formed along with a non-identified transformation product. The environmental presence of most of the metabolites and transformation products was qualitatively demonstrated by analysis of soil samples taken in close proximity to an airport fire training facility.  相似文献   
5.
Strandberg M  Damgaard C  Degn HJ  Bak J  Nielsen KE 《Ambio》2012,41(4):393-401
We report observations of disappearance of Erica tetralix in wet heathland, which is unlikely to be caused by competition, as E. tetralix is dying before its place is taken up by other species. To investigate the causes, we used both old and new data. Results showed that presence of Molinia caerulea and Calluna vulgaris were substantial in the former E. tetralix dominated areas. Measurements of the C/N ratio in the morlayer were between 21 and 26 under the E. tetralix stands. As the expected C/N ratio in a healthy nutrient poor ecosystem like the E. tetralix wet heathland is around 30, this indicates that the ratio is probably decreasing and, correspondingly, the probability of nitrogen leaching from the ecosystem is increasing. The morlayer pH was extremely low—between 3.03 and 3.78. This represents a pH decline since the 1960s, where pH values generally were above 4. This supports the hypothesis that the decrease in morlayer pH is the major factor explaining the disappearance of E. tetralix and that measures to increase pH should be considered as part of the recommendations for relevant future management.

Electronic supplementary material

The online version of this article (doi:10.1007/s13280-012-0251-z) contains supplementary material, which is available to authorized users.  相似文献   
6.

Objective

This work aims to investigate the correlation between the photocatalytic activity determined by methylene blue bleaching (DIN 52980), stearic acid degradation, and degradation of acetone in gas phase.

Method

The photocatalytic TiO2 coatings included in this investigation ranged from thin commercially available coatings (ActivTM and BioCleanTM) and ready to use suspensions (Nano-X PK1245) to lab-produced PVD and sol?Cgel coatings. XRD analysis of the photocatalytic coatings showed that all the coatings consisted of nanocrystalline anatase, although the thickness and porosity varied considerably.

Results

The study showed that the reproducibility of the activity measurements was good. However, more importantly, the investigation showed that there is a good correlation between the activities determined by the different methods even though the characteristics of the photocatalytic coatings and the organic probe molecules varied considerably.

Conclusion

The overall findings of this work suggest that there is a good correlation between the investigated methods. These results are promising for the future work concerning standardization of methods for determination of the activity of photocatalytic films.  相似文献   
7.
8.
This paper describes the effect of a herbicide applied at levels consistent with off target movement on hawthorn the year following exposure. In the experiment, metsulfuron-methyl was applied in five dosages to individual trees in seven different hawthorn hedgerows. Spraying was conducted both at the bud stage and at the early flowering. Five endpoints (i.e. leaves, buds, flowers, green berries and mature berries) were sampled and counted. All were significantly reduced with increasing exposure. Present day risk assessment of effects on non-target plants is therefore likely to overlook significant effects on perennial non-target plants in the spray drift zone due to the focus on results from short-term laboratory test studies. The significance of the present study is underlined by the fact that the effects observed were significant, even though other influential factors such as herbivory and differential pollination were not eliminated and that experiments were conducted in multiple locations.  相似文献   
9.
The invasive red alga Gracilaria vermiculophylla has quickly spread across Europe, but it is unclear whether its success is based on a high tolerance to variations in environmental conditions or to the absence of native grazers that feed on this alga. We tested whether native invertebrate grazers prefer native algae to G. vermiculophylla. Feeding preferences of three common herbivores were quantified when offered G. vermiculophylla and native Fucus vesiculosus, Ceramium virgatum, and Ulva intestinalis in no-, two- and multiple-choice trials. Herbivore growth was measured when fed each of the algae separately. Grazers consumed G. vermiculophylla in no-choice trials, but avoided generally this alga when having a choice. U. intestinalis was always preferred over G. vermiculophylla, and grazers fed with U. intestinalis grew faster than those fed with G. vermiculophylla. We conclude that grazers avoid G. vermiculophylla to most native algae, which may benefit G. vermiculophylla in northern European estuaries.  相似文献   
10.
The littoral zone of temperate rocky shores is normally dominated by perennial macroalgae (e.g. Fucus, Ascophyllum, Laminaria), but nutrient enrichment and/or permanently decreased wave action may lead to structural community changes from dominance of perennials to increased amounts of annual opportunistic species (mainly green algae). Macroalgal biomass, diversity and production as well as relationships between the two latter were studied using Solbergstrand’s rocky shore mesocosms in SE Norway in connection with a long-term experimental manipulation of nutrient addition and wave action (high and low levels of both factors applied in a crossed way to eight outdoor basins). After more than 2 years of experimental treatment, the total standing stock of macroalgae was larger in low nutrient than in high nutrient treatments as well as in high wave compared to low wave treatments (in autumn only). For macroalgal functional groups, bushy and filamentous brown and filamentous red algae were generally favoured by low nutrient concentrations, while annual filamentous and sheet-like green algae were stimulated by the nutrient enrichment. There was only one significant interaction between nutrient enrichment and wave action (for brown filamentous algae in autumn) and also only one significant main effect of the wave treatment (for bushy brown algae in autumn). Surprisingly, the high nutrient treatments supported a higher diversity of macroalgae, whereas the low nutrient treatments generally showed higher production rates. Moreover, significantly negative correlations were found between macroalgal diversity and primary productivity in both summer and autumn. This study shows that it is the biological components of the communities subjected to external forcing (nutrient addition or decreased wave action) that regulate production and this contradicts the common misperception that resource production in natural systems simply can be fast-forwarded by fertilization. The negative relationships between diversity and productivity, although a consequence of unexpected results for diversity and production, are also novel and hint towards species identities having more important functional consequences than general species dominance patterns and the amount of species per se. These results also emphasise the context dependency of findings within the field of biodiversity and ecosystem functioning.  相似文献   
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