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311.
Next to energy efficiency, in the context of GHG reductions, additional policy mechanisms to the incumbent EU Emissions Trading scheme (EU ETS) are discussed. Such is the case of Non-ETS Domestic Offset (DO) schemes, which can reduce CO2-eq.emissions in the non-ETS sectors and trade these as CO2 credits on the ETS market. Taking into account that the EU’s “Linking Directive” (EC 2004) creates the conditions to use credits generated by emission reduction projects certified by the UN Framework Convention on Climate Change Kyoto Protocol (KP) within the EU ETS market, in this paper we employ the institutional analysis method of interactions in order to provide insight of a combined White Certificates (WhC) and DOs cheme. Special attention is paid to the parameters that seem to hamper harmonization of WhC and DO. Aim of this paper is to discuss whether smart market- based instruments, such as WhC, can be complementary to the effectiveness of mechanisms fostering energy efficiency such as DOs projects and vice versa. In this respect, the potential combined scheme is assessed (ex-ante) with the help of standard criteria that refer to the triptych energy, environment & society. Given the outcome of the study made, it is fair to say that such a DO/WhC combined scheme could be selected if the additionality concern is to minimize short term social costs of reaching a certain goal. However recent information and research conducted so far cannot yet uphold an ambition that a WhC/DO scheme of this kind could also drive technical change, keep consumer costs down and be equitable.  相似文献   
312.
313.
Environmental Fluid Mechanics - The flow pattern within a storage zone governs the efficiency of passive scalar accumulation, spreading and homogenization. The present paper aims at characterizing...  相似文献   
314.
In this study the Reynolds-averaged Navier-Stokes computational fluid dynamics methodology is used, which has proved to be a powerful tool for the simulations of the airflow and pollutant dispersion in the atmospheric environment. The interest is focused on the urban areas and more specifically on the street canyons, several types of which are examined in order to evaluate the performance of various turbulence models, including a Reynolds-stress model and variations of the k-ε model. The results of the two-dimensional simulations are compared with measurements from a diversity of independent street canyon experimental datasets, covering a wide range of aspect ratios, free stream velocities and roughnesses. This way more general and reliable conclusions can be reached about the applicability, accuracy and ease of use of each turbulence model. In this work, the renormalization group k-ε presented better results in most cases examined, while the Reynolds-stress model did not stand up for the expectations and also exhibited convergence problems.  相似文献   
315.
Among rewardless orchids, pollinator sampling behavior has been suggested to drive a positive relationship between population phenotypic variability and absolute reproductive success, and hence population fitness. We tested this hypothesis by constructing experimental arrays using the rewardless orchid Dactylorhiza sambucina, which is dimorphic for corolla color. We found no evidence that polymorphic arrays had higher mean reproductive success than monomorphic arrays for pollinia removal, pollen deposition, or fruit set. For pollinia removal, monomorphic yellow arrays had significantly greater reproductive success, and monomorphic red the least. A tendency for yellow arrays to have higher pollen deposition was also found. We argue that differential population fitness was most likely to reflect differential numbers of pollinators attracted to arrays, through preferential long-distance attraction to arrays with yellow inflorescences. Correlative studies of absolute reproductive success in 52 populations of D. sambucina supported our experimental results. To our knowledge this is the first study to suggest that attraction of a greater number of pollinators to rewardless orchids may be of greater functional importance to population fitness, and thus ecology and conservation, than are the behavioral sequences of individual pollinators.  相似文献   
316.
Parasites relying on trophic transmission to complete their life cycles often induce modifications of their host's behavior in ways that may increase their susceptibility to predation by final hosts. These modifications have often been interpreted as parasite adaptations, but very few studies have demonstrated that host manipulation has fitness benefits for the parasite. The aim of the present study was to address the adaptive significance of parasite manipulation by coupling observations of behavioral manipulation to estimates of trophic transmission to the definitive host in the natural environment. We show that the acanthocephalan parasite Pomphorhynchus laevis manipulates the drifting behavior of one of its intermediate hosts, the amphipod Gammarus pulex, but not of a sympatric host, the introduced amphipod Gammarus roeseli. We found a 26.3-28.3 times higher proportion of infected G. pulex in the stomach content of one of the definitive hosts of P. laevis, the bullhead Cottus gobio, than in the benthos. No such trend was observed for G. roeseli. The bell-shaped curve of mean parasite abundance (MPA) relative to host size observed in G. pulex also supported an increased predation mortality of P. laevis-infected individuals compared to uninfected amphipods. Again, no such pattern was observed in G. roeseli. Furthermore, our results indicate that the modifications induced by P. laevis are specific to the definitive host and do not increase the risk of predation by inappropriate hosts, here the adult edible frog Rana esculenta. Overall, our study is original in that it establishes, under field conditions, a direct link between parasitic manipulation and increased transmission to the definitive host, and more importantly, identifies the specificity of the manipulation both in the intermediate host species and toward the definitive host.  相似文献   
317.
Desneux N  Denoyelle R  Kaiser L 《Chemosphere》2006,65(10):1697-1706
Insecticides are widely used for crop protection. Effectiveness of pesticides and beneficial arthropods in an Integrated Pest Management (IPM) program requires a full understanding of how specific pesticides alter natural enemy effectiveness. This may require evaluation of chemicals at different life stages of the insect considered, on different physiological and behavioural components, and also on population dynamic components such as recolonization capacities after a pesticide treatment. Aphidius ervi Haliday (Hymenoptera: Braconidae) is an aphid parasitoid commonly used for the biological control of aphid populations. In this work, our aim was to assess the effects of deltamethrin (pyrethroid) treatments on this parasitoid using a multi-step bioassay. We evaluated its effects on parasitoid emergence, adult survival and longevity, and host searching. Two exposure methods were used, topical and spray, to evaluate impact of the deltamethrin field rate (6.25ga.i./ha) and also to compare the methods of exposure. A four-armed olfactometer was used to investigate effect of deltamethrin on host searching behaviour. When applied at the rate of field exposure, deltamethrin reduced the adult longevity but not the rate of emergence from mummies. Effects varied between the two exposure methods. Two indices were defined: the "population survival index" to measure capacity of parasitoids to recolonize a treated field and the "reproductive potential" to estimate the reduction in reproduction as a function of longevity decrease. These indices predicted effects of deltamethrin on A. ervi in terms of mortality and reduction of recolonization capacities. However, adults that survived residual exposure to deltamethrin retained their ability to orient to host odours. The implications of results in IPM and interest of the methodology used are both discussed.  相似文献   
318.
In case of a major incident or disaster, the advance medical rescue command needs to manage several essential tasks simultaneously. These include the rapid deployment of ambulance, police, fire and evacuation services, and their coordinated activity, as well as triage and emergency medical care on site. The structure of such a medical rescue command is crucial for the successful outcome of medical evacuation at major incidents. However, little data has been published on the nature and structure of the command itself. This study presents a flexible approach to command structure, with two command heads: one emergency physician and one experienced paramedic. This approach is especially suitable for Switzerland, whose federal system allows for different structures in each canton. This article examines the development of these structures and their efficiency, adaptability and limitations with respect to major incident response in the French‐speaking part of the country.  相似文献   
319.
The tube-building polychaete Lanice conchilega can form dense populations, often called reefs, which promote benthic community change and constitute feeding grounds for secondary consumers. The aim of this study was to quantify the role of the L. conchilega reef of the Bay of the Mont Saint-Michel (BMSM) for feeding waders, by combining macrobenthos data, bird counts and bird diet information. Wader densities in the reef were on average 46.6 times higher than in non-reef areas. According to faecal analyses, waders in the reef mainly selected the accompanying fauna and especially crustaceans. The attractiveness of the reef to feeding birds may be largely explained by the high abundance, richness and biomass of macrobenthic species in the reef compared with the rest of the BMSM.  相似文献   
320.
Phytoextraction is a technology that uses plants to remove heavy metals from contaminated soils. Although it is economically attractive compared to other methods, little attention has been paid to the mathematical modeling of the mechanisms involved. In this work, we simulate the phytoextraction of Pb using a mechanistic system dynamics modelling approach and the physiology model of maize (Zea mays) as a model system as it is a good Pb accumulator and translocator. Simulation results showed that precipitation is the most important mechanism related to the uptake of Pb from the ground. The most important model parameters have been identified through sensitivity analysis.  相似文献   
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