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21.
Carnivorous zooplankton is a key element to the energy transfer through the arctic food web, linking lipid rich herbivores to the top predators. We investigated the growth and lipid dynamic of the Arctic pelagic amphipod Themisto libellula in Kongsfjorden (Svalbard, 79°N) from May to October 2007. Additional samplings were performed in spring and summer 2006 and further north in Rijpfjorden (80°N), in September 2006 and 2007. In Kongsfjorden, the first free-swimming stages (3 mm) appeared early May and reached their adult length (25 mm), in October. During their first year, they grew according to a Von Bertalanffy model and most probably constituted a single cohort. Juveniles had the highest growth rate (0.19 mm day−1) and revealed relatively low total lipid (TL) content (about 2.5% wet weight (WW)) with phospholipids as the major lipid class. Sub-adults showed a distinct decrease of growth rates which coincided with the increase of neutral lipid storage, reflecting a switch in energy allocation, from somatic growth to lipid storage. Indeed wax esters (WE) increased up to 48.5% TL on average in adults in 2006 while triacylglycerols (TAG) remained almost constant below 25.2% TL. The absence of lipid accumulation (in disproportion of the weight) in 2007 could be explained by a higher metabolism of T. libellula or preys of lower quality. In Rijpfjorden, adults in their second year continued accumulating lipid (up to 10% WW) with high and similar proportions of both lipid classes, WE and TAG. We highlighted that T. libellula exhibited a variable lipid metabolism along its life cycle depending on its physiological needs and environmental conditions.  相似文献   
22.
The wine industry has developed greatly over recent years, and it could be stated that what was once a traditional industry has become a very productive and technical sector. One aspect that has not been studied until now is the cork stopper, despite the fact that most wine bottles are sealed with this product, and practically all corks are produced in the Iberian Peninsula.This study presents the environmental analysis of the production of natural cork stoppers, using life cycle assessment (LCA) methodology. The research was supported by data from four Catalan representative companies and all the stages involved in the production after the forest management have been taken into account. The purpose of this research was to provide reference data for the Catalan cork industrial sector (Northeast Spain), and also contribute to deciding which aspects of natural cork stopper production must be improved and further researched. Another objective of this research was to emphasise and demonstrate that LCA methodology could be an interesting tool for improving traditional industry, from a cleaner production perspective.Results could be used by other sector companies to analyse and compare themselves with in order to know if they could improve their production with the current available technology. Impact assessment results indicate that the manufacturing stage was the stage causing the greatest impact, but also an evaluation of the influence of the initial transport from the forest reveals that this stage could notably increase the impact when raw cork was moved from distant forests.  相似文献   
23.
Asian knotweeds (Fallopia spp.) are considered one of the world’s most invasive species. Restoring habitats dominated by these exotic species requires a better understanding of the importance of abiotic factors controlling the invasive knotweeds performance. We used observational data obtained on the embankment of the Isère River (France) to study the performance of Fallopia spp. under different soil, light, and disturbance conditions. On the Isère riverbanks, light intensity assessed by light quantity transmitted through canopy was the most important factor explaining the variability observed on knotweed performance expressed as above-ground biomass per square meter. Asian knotweeds were more productive under intensive light conditions. Alternatively other factors such as mowing (twice a year), soil fertility, soil texture, position on the bank or exposure to the sun had no significant effect on knotweed biomass production. We conclude that decreasing light resources, for example, by increasing competitive pressure on sites dominated by Asian knotweeds could be included in management plans to control the populations of this invasive taxon.  相似文献   
24.
Dinitrotoluenes (DNTs) are widely used in the manufacturing of explosives and propellants hence causing contamination of several terrestrial and aquatic environments. The present study describes biotransformation of 2,4-DNT and 2,6-DNT in marine sediment sampled from a shipwreck site near Halifax Harbour. Incubation of either 2,4-DNT or 2,6-DNT in anaerobic sediment slurries (10% w/v) at 10 degrees C led to the reduction of both DNTs to their corresponding diaminotoluene (2,4-DAT and 2,6-DAT) via the intermediary formation of their monoamine derivatives (ANTs). The production of diaminotoluene was enhanced in the presence of lactate for both DNT isomers. Using [(14)C]-2,4-DNT less than 1% mineralization was observed as determined by liberated (14)CO(2). Sorption of DNTs, ANTs, and DATs was thus investigated to learn of their fate in marine sediments. Under anaerobic conditions, sorption followed the order: DNTs (K(d)=8.3-11.7lkg(-1))>ANTs (K(d)=4.5-7.0lkg(-1))>DATs (K(d)=3.8-4.5lkg(-1)). Incubation of 2,4-DAT in aerobic sediment led to rapid disappearance from the aqueous phase. LC/MS analysis of the aqueous phase and the acetone sediment extract showed the formation of azo- and hydrazo-dimers and trimers, as well as unidentified polymers. Experiments with radiolabelled 2,4-DAT showed a mass balance distributed as follows: 22% in the aqueous phase, 24% in acetone extracts, and 50% irreversibly bound to sediment. We concluded that DNT in anoxic marine sediment can undergo in situ natural attenuation by reduction to DAT followed by oxidative coupling to hydrazo-oligomers or irreversible binding to sediment.  相似文献   
25.
Hexanitrohexaazaisowurtzitane (CL-20) is an emerging explosive that may replace the currently used explosives such as RDX and HMX, but little is known about its fate in soil. The present study was conducted to determine degradation products of CL-20 in two sandy soils under abiotic and biotic anaerobic conditions. Biotic degradation was prevalent in the slightly acidic VT soil, which contained a greater organic C content, while the slightly alkaline SAC soil favored hydrolysis. CL-20 degradation was accompanied by the formation of formate, glyoxal, nitrite, ammonium, and nitrous oxide. Biotic degradation of CL-20 occurred through the formation of its denitrohydrogenated derivative (m/z 393 Da) while hydrolysis occurred through the formation of a ring cleavage product (m/z 156 Da) that was tentatively identified as CH2N-C(N-NO2)-CHN-CHO or its isomer N(NO2)CH-CHN-CO-CHNH. Due to their chemical specificity, these two intermediates may be considered as markers of in situ attenuation of CL-20 in soil.  相似文献   
26.
Increased development pressures on the marine environment and the potential for multiple use conflicts, arising as a result of the current expansion of offshore wind energy, fishing and aquaculture, dredging, mineral extraction, shipping, and the need to meet international and national commitments to biodiversity conservation, have led to increased interest in sea use planning with particular emphasis on marine spatial planning. Several European countries, on their own initiative or driven by the European Union's Marine Strategy and Maritime Policy, the Bergen Declaration of the North Sea Conference, and the EU Recommendation on Integrated Coastal Zone Management, have taken global leadership in implementing marine spatial planning. Belgium, The Netherlands, and Germany in the North Sea, and the United Kingdom in the Irish Sea, have already completed preliminary sea use plans and zoning proposals for marine areas within their national jurisdictions. This paper discusses the nature and context of marine spatial planning, the international legal and policy framework, and the increasing need for marine spatial planning in Europe. In addition, the authors review briefly three marine spatial planning initiatives in the North Sea and conclude with some initial lessons learned from these experiences.  相似文献   
27.
In the 1980s, tropical forest-management principles underwent a shift toward approaches giving greater responsibilities to rural people. One argument for such a shift were the long-term relations established between rural people and their natural resources. In Madagascar, a new law was drawn up in 1996 (Gelose law), which sought to integrate rural people into forest management. A gap was observed between the changes foreseen by the projects implementing the Gelose law and the actual changes. In this article, we use the concept of the social-ecological system (SES) to analyze that gap. The differences existing between the planned changes set by the Gelose contract in the village of Ambatoloaka (northwest of Madagascar) and the practices observed in 2010 were conceptualized as a gap between two SESs. The first SES is the targeted one (i.e., a virtual one); it corresponds to the designed Gelose contract. The second SES is the observed one. It is characterized by the heterogeneity of forest users and uses, which have several impacts on forest management, and by very dynamic social and ecological systems. The observed SES has been reshaped contingent on the constraints and opportunities offered by the Gelose contract as well as on other ecological and social components. The consequences and opportunities that such an SES reshaping would offer to improve the implementation of the Gelose law are discussed. The main reasons explaining the gap between the two SESs are as follows: (1) the clash between static and homogeneous perceptions in the targeted SES and the dynamics and heterogeneity that characterize the observed SES; and (2) the focus on one specific use of forest ecosystems (i.e., charcoal-making) in the targeted SES. Forest management in the observed SES depends on several uses of forest ecosystems.  相似文献   
28.
The diagnostic value of amniotic fluid gamma-glutamyl-transpeptidase (GGTP) and intestinal alkaline phos-phatase (iALP) was evaluated in 55 patients who underwent amniocentesis for karyotyping because fetal gastric or small bowel dilatation had been detected by ultrasound. Gastrointestinal malformation was confirmed in 46 cases and there was no gastrointestinal anomaly in nine cases. Prenatal ultrasound was suggestive of gastroduodenal dilatation in 34 cases (group I) and small bowel dilatation in 21 cases (group II). In group I, amniotic fluid GGTP above the 99th percentile was 71 per cent sensitive and 100 per cent specific for a true anatomical defect of the digestive tract (mainly duodenal atresia). In group II, high levels of GGTP and/or iALP were 69 per cent sensitive and 83 per cent specific for a fetal digestive tract anomaly. In other words, when digestive tract dilatations were diagnosed by prenatal sonography, abnormal amniotic fluid enzyme activities were strongly suggestive of such an anomaly, the possibility of which was not precluded by normal amniotic fluid iALP and GGTP activities. But amniotic fluid digestive enzyme activities do not help in defining the prognosis.  相似文献   
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