63 research outputs found
Defining freshwater as a natural resource: a framework linking water use to the area of protection natural resources
© 2019, Springer-Verlag GmbH Germany, part of Springer Nature. Purpose: While many examples have shown unsustainable use of freshwater resources, existing LCIA methods for water use do not comprehensively address impacts to natural resources for future generations. This framework aims to (1) define freshwater resource as an item to protect within the Area of Protection (AoP) natural resources, (2) identify relevant impact pathways affecting freshwater resources, and (3) outline methodological choices for impact characterization model development. Methods: Considering the current scope of the AoP natural resources, the complex nature of freshwater resources and its important dimensions to safeguard safe future supply, a definition of freshwater resource is proposed, including water quality aspects. In order to clearly define what is to be protected, the freshwater resource is put in perspective through the lens of the three main safeguard subjects defined by Dewulf et al. (2015). In addition, an extensive literature review identifies a wide range of possible impact pathways to freshwater resources, establishing the link between different inventory elementary flows (water consumption, emissions, and land use) and their potential to cause long-term freshwater depletion or degradation. Results and discussion: Freshwater as a resource has a particular status in LCA resource assessment. First, it exists in the form of three types of resources: flow, fund, or stock. Then, in addition to being a resource for human economic activities (e.g., hydropower), it is above all a non-substitutable support for life that can be affected by both consumption (source function) and pollution (sink function). Therefore, both types of elementary flows (water consumption and emissions) should be linked to a damage indicator for freshwater as a resource. Land use is also identified as a potential stressor to freshwater resources by altering runoff, infiltration, and erosion processes as well as evapotranspiration. It is suggested to use the concept of recovery period to operationalize this framework: when the recovery period lasts longer than a given period of time, impacts are considered to be irreversible and fall into the concern of freshwater resources protection (i.e., affecting future generations), while short-term impacts effect the AoP ecosystem quality and human health directly. It is shown that it is relevant to include this concept in the impact assessment stage in order to discriminate the long-term from the short-term impacts, as some dynamic fate models already do. Conclusions: This framework provides a solid basis for the consistent development of future LCIA methods for freshwater resources, thereby capturing the potential long-term impacts that could warn decision makers about potential safe water supply issues in the future
Optimization of microbial transglutaminase production using experimental designs
International audienceIn prokaryotes, transglutaminase (TGase) has been found only in actinomycetes from the genus Streptoverticillium. The role of this TGase, as well as the mechanism regulating the enzyme expression, are still unknown. In order to improve TGase production by Streptoverticillium cinnamoneum CBS 683.68 and simultaneously elucidate the relationship between growth and TGase activity, we decided to study these two responses using different designs of statistical analysis. Among the five factors tested, casein, glycerol, peptones, yeast extract and oligoelements, only oligoelements were found to have no effect either on growth or on TGase production in a complete factorial design. The two factors casein and glycerol were found to have a highly significant effect on both dry weights and TGase activity in a Box-Behnken design used to improve the model. Finally, the TGase activity was increased three times to reach 0.331 ± 0.038 U/ml with optimum concentrations of casein (38.4 g/l) and glycerol (31.2 g/l) calculated with the help of a composite design. In the course of these experiments, the two responses varied in the same way, demonstrating that growth and TGase production were tightly correlated under the conditions described. However, TGase was produced during the stationary phase of growth in optimized medium, indicating that the enzyme production could be induced
Etude acoustique du réflexe Lombard en vue de la reconnaissance de la parole produite en milieu bruité
Le but de cette étude est de déterminer pour le français, au niveau phonétique, les différences acoustiques entre la parole normale et la parole prononcée en milieu bruité (soumise au réflexe Lombard). Ce travai1 fait suite à une première étude que nous avons effectué sur l'anglais-américain. La même méthodologie a été adoptée pour les deux langues, et les mêmes paramètres acoustiques ont été extraits, ce qui se justifie par leur utilisation similaire dans les différents systèmes de reconnaissance de la parole étudiés pour les deux langues. Les résultats obtenus au cours de la première étude sur l'anglais-américain [1] ont montré des tendances d'évolution de nombreux paramètres acoustiques. Dans ce papier, nous présentons les résultats obtenus pour le français. Ils confirment les tendances observées dans [1], et montrent ainsi qu'il existe une forte corrélation entre les modifications acoustiques engendrées par le réflexe Lombard sur l'anglais-américain et le français
Biochemical and morphological studies on collagens of horny sponges. Ircinia filaments compared to spongines.
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Chapter 10 Leachates and organic extracts from solids
International audienceThis chapter presents some applications related with landfill leachates, contaminated soils, and solid waste composts. A complementary study concerning natural sediments is presented in the chapter. Landfill leachates are considered to be highly polluted media, containing various organic compounds refractory to biodegradation. Regarding leachate analysis, ultraviolet (UV) spectrophotometry can be useful for a fast characterization or the study of landfill evolution. Depending on the nature of organic components, aqueous solutions can limit the interest of the approach. In this case, an extraction step of the solid matrix with an organic solution can be necessary in order to have more specific information. The aim of solid wastes treatment is both to reduce their size and to stabilize their organic content. The characterization of natural soils and sediments with UV spectrophotometry applied after leaching tests is possible
Sugar-specific endocytosis of glycoproteins by Lewis lung carcinoma cells
International audienceLewis lung carcinoma cells from tumors, metastasis nodules, or from culture bind fluorescent derivatives of neoglycoproteins containing alpha-D-glucose residues: This binding is competitively inhibited by neoglycoproteins containing alpha-D-glucose, by mannan, and by several other neoglycoproteins. Cell binding and uptake of the fluorescent derivatives of the neoglycoproteins was quantified by lysing the cells with an alkylpolyol (MAC 19 or MAC 18) and measuring the fluorescence intensity of the supernatant. The amount of cell-associated neoglycoprotein was higher at 37 degrees C than at 4 degrees C with LLC from tumor. The binding and uptake were inhibited by glycoconjugates containing alpha-D-glucose. These results suggest the presence of sugar specific receptors in Lewis lung carcinoma cells which are involved in a sugar-specific binding and endocytosis phenomenon. The implication of the existence of a carbohydrate-binding protein on the surface of Lewis lung carcinoma cells are discussed with regard to the in vivo behaviour of these cells, especially in relation to their metastatic properties and to the possibility of using neoglycoproteins as specific carriers of cytotoxic drugs. Hybrid molecules of gelonin and neoglycoprotein containing alpha-D-glucose were used as targetted toxin: The targetted toxin was found to bind to and to enter the intact cells and was 100 times more toxic than free drug
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