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Since the early 2000s routine fish surveys have recorded increasing numbers of snake pipefish, Entelurus aequoreus, in the northeast Atlantic. Fishermen and divers have also commented on this increase and pipefish have started to appear in the diet of seabirds and other marine predators. This paper collates information from these diverse sources and assesses the current status of snake pipefish. We found compelling evidence of a dramatic increase in the abundance of snake pipefish starting around 2003 and continuing up to the present (2006) and a range expansion northwards to Spitzbergen and the Barents Sea. Since 2004 snake pipefish have been increasingly recorded in the diet of many species of seabird breeding in colonies around the coast of the UK, and in Norway, Iceland and the Faeroe Islands. Information on the nutrient value of snake pipefish is currently lacking but their rigid, bony structure makes them difficult for young seabirds to swallow and there are numerous records of chicks choking to death. Thus, in the case of avian predators during the breeding season, it appears unlikely that increased abundance of snake pipefish will provide a useful alternative prey. The reason for the rapid and dramatic increase in numbers of snake pipefish is currently unclear but such events are characteristic of marine ecosystems and will almost certainly have an effect on food web dynamics.  相似文献   
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A new modelling approach to urban sprawl dynamics is introduced which allows representing qualitative knowledge on relations between moving actor populations and properties of locations. The results of this Qualitative Attractiveness Migration (QuAM) Model are scenario-like sets of possible future developments of the urban system, much in contrast to quantitative forecasts gained by traditional modelling approaches. QuAM models allow for the interaction between internal dynamics and external influences. The application of the new approach is exemplified by the case of urban sprawl in Leipzig since 1990. It was possible to reproduce the observed qualitative development and to calculate future scenarios. The scenario runs project a new wave of middle class driven residential sprawl and suggest implications for sprawl reducing policy interventions.  相似文献   
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Behavioral studies of gynandromorphism, also called as sex mosaic, contribute to the understanding of the relationship between morphological gender and sexual identity of an animal. Few studies have focused on the behaviors of gynandromorphic spiders because of a scarcity of gynandromorphic individuals in the field. In this study, we collected a gynandromorphic spider, Myrmarachne formicaria (De Geer 1778) (Araneae: Salticidae), from the field and examined its morphology and sex-specific behavior in the laboratory. The right half of the gynandromorphic spider presented male characteristics and the left half female characteristics. It showed courtship behavior to M. formicaria females and agonistic behavior to the males. These results indicate that the gynandromorphic spider’s sexual identity is male. Our findings suggest that a spider can exhibit behaviors of male sexuality, although the external morphology has the characteristics of both sexes. To the best of our knowledge, this is the first report of a gynandromorphic individual and its behavior in the genus Myrmarachne.

  相似文献   
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Mitigation and Adaptation Strategies for Global Change - The assessment of greenhouse gases (GHGs) and air pollutants emitted to and removed from the atmosphere ranks high on international...  相似文献   
198.
Learning for change: an educational contribution to sustainability science   总被引:2,自引:2,他引:0  
Transition to sustainability is a search for ways to improve the social capacity to guide interactions between nature and society toward a more sustainable future and, thus, a process of social learning in its broadest sense. Accordingly, it is not only learning that is at issue but education and educational science, of which the latter is about exploring the preconditions of and opportunities for learning and education—whether individual or social, in formal or informal settings. Analyzing how educational science deals with the challenge of sustainability leads to two complementary approaches: the ‘outside-in’ approach sees the idea of sustainability influencing educational practice and the way the relationship of learning and teaching is reviewed, theoretically as well as within the social context. In an ‘inside-out’ approach, an overview is given of how educational science can contribute to the field of sustainability science. An examination of the literature on education and sustainability shows that, while sustainability features prominently in one form or another across all sectors, only little work can be found dealing with the contributions of educational science within sustainability science. However, as sustainability is a concept that not only influences educational practices but also invites disciplinary contributions to foster inter- and transdisciplinary research within the sustainability discourse, the question remains as to how and to what extent educational science in particular can contribute to sustainability science in terms of an ‘inside-out’ approach. In this paper, we reconstruct the emergence of education for sustainable development as a distinctive field of educational science and introduce and discuss three areas of sustainability research and throw into relief the unique contribution that educational science can make to individual action and behavior change, to organizational change and social learning, and, finally, to inter- and transdisciplinary collaboration.  相似文献   
199.
The addition of straw in combination with Carbokalk, a by-product from the sugar-industry, was successfully used to stimulate microbial alkalinity generation in an acidic mining lake. To get detailed information about functions of straw, anenclosure experiment was carried out. Straw bundles were placedat the sediment surface of an acidic mining lake (ML 111) and thephysiochemical conditions and the microbiology of the sediment-water contact zone were studied. Straw was degraded by anaerobic microorganisms and dissolved organic carbon (DOC) leached from straw bundles. Pigmented flagellates responded to the DOC supply in the water column anda considerable amount of algal carbon was transported to the sediment. Straw addition led to microbial reduction of iron andsulfate in the sediment. Sulfate reduction was observed at a pHof 5.5. The pH, however, was not high enough to precipitate H2S completely. Thus, some H2S diffused into the watercolumn, where it was reoxidized. Straw did not create orstabilize an anoxic water body above the sediment. Microbial sulfate reduction and pyrite formation only took place in the sediment,whereas iron reduction also took place in the straw. Straw, however, altered the flow conditions above the sediment surfaceand prevented complete mixing of the profundal water. Straw didnot serve as a substratum for a reactive biofilm. We conclude that the most important function of straw for mining lake remediation is to be a long-term nutrient source for microbialalkalinity generation in the sediment.  相似文献   
200.
13C/12C stable carbon isotope fractionation was used to assess biodegradation in contaminated aquifers with toluene as a model compound. Different strains of anaerobic bacteria (Thauera aromatica, Geobacter metallireducens, and the sulfate-reducing strain TRM1) showed consistent 13C/12C carbon isotope fractionation with fractionation factors between C = 1.0017 and 1.0018. In contrast, three cultures of aerobic organisms, using different mono- and dioxygenase enzyme systems to initiate toluene degradation, showed variable isotope fractionation factors of C = 1.0027 (Pseudomonasputida strain mt-2), C = 1.0011 (Ralstonia picketii), andC = 1.0004 (Pseudomonas putida strain F1). The great variability of isotope fractionation between different aerobic bacterial strains suggests that interpretation of isotope data in oxic habitats can only be qualitative. A soil column was run as a model system for contaminated aquifers with toluene as the carbon source and sulfate as the electron acceptor and samples were taken at different ports along the column. Microbial toluene degradation was calculated based on the 13C/12C isotope fractionation factors of the batch culture experiments together with the observed 13C/12C isotope shifts of the residual toluene fractions. The calculated percentage of biodegradation, B, correlated well with the decreasing toluene concentrations at the sampling ports and indicated the increasing extent of biodegradation along the column. The theoretical toluene concentrations as calculated based on the isotope values matched the measured concentrations at the different sampling ports indicating that the Rayleigh equation can be used to calculate biodegradation in quasi closed systems based on measured isotope shifts. A similar attempt was performed to assess toluene degradation in a contaminated, anoxic aquifer. A transect of groundwater wells was monitored along the main direction of the groundwater flow and revealed decreasing concentrations accompanied with an increase in the 13C/12C stable carbon isotope ratio of the residual toluene. Calculation of the extent of biodegradation based on the isotope values and laboratory derived isotope fractionation factors showed that the residual toluene was degraded to more than 99% by microbial activity. Calculation of the theoretical residual toluene concentrations based on the measured isotope values described the strongly decreasing concentrations along the plume. Other aromatic hydrocarbons like benzene and naphthalene which were analysed in the same course also showed decreasing concentrations along the groundwater flow path accompanied by increasing 13C values indicating biodegradation.  相似文献   
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