Hypo-osmoregulatory capacity (or hypo-OC, i.e., the difference between the osmolality of the haemolymph and that of sea water), haemolymph glycemia and haemolymph sodium and chloride concentrations ...of Penaeus stylirostris were studied in experimental tanks according to the size, the molt stage and the nutritional status of the shrimp. Osmolality and haemolymph glycemia of fed and starved P. stylirostris were also studied in earthen ponds in fluctuating sea water according to time. In experimental tanks, the absolute hypo-OC of shrimp decreased linearly with increasing wet weight for each molt stage considered. For specimens weighing 16.6 plus or minus 1.7 g, the absolute hypo-OC was maximum in stage C (217 plus or minus 17 mosm kg super(-1)) and significantly lower in stages B (165 plus or minus 16 mosm kg super(-1)), D sub(0) (181 plus or minus 18 mosm kg super(-1)), D sub(1) (146 plus or minus 20 mosm kg super(-1)) and D sub(2) (135 plus or minus 13 mosm kg super(-1)). The hypo-OC and haemolymph glucose concentration varied significantly after the food supply. No variations in haemolymph sodium and chloride concentrations were observed. In earthen ponds, haemolymph osmolality and haemolymph glucose concentration of molt stage C shrimp increased shortly after the food supply. When shrimp were kept starved for 24 and 48 h, haemolymph osmolality remained constant and haemolymph glucose concentration varied only slightly according to time. In light of these results, the use of shrimp hypo-OC (and/or haemolymph osmolality) and haemolymph glycemia in aquaculture as potential physiological indicators of disturbance in the aquatic environment is discussed.
The rotational part of earthquake-induced ground motion has basically been ignored in the past decades, compared to the substantial research in observing, processing and inverting translational ...ground motions, even though there are theoretical considerations that suggest that the observation of such motions may indeed be useful and provide additional information. In the past years, interest in this potentially new observable for seismology has risen, primarily because with modern acquisition technology such as fiber-optical or ring laser gyros rotational motions have actually been observed, the resolution is steadily increasing, and the observations are becoming consistent with collocated recordings of translational ground motions.
Finite-fault source inversions reveal the spatial complexity of earthquake slip over the fault plane. In this study, several possible earthquake scenarios of Mw7.0 are simulated with different ...quasi-dynamic finite source models for the Newport Inglewood (NI) fault system in the Los Angeles (LA) basin embedded in the 3-D SCEC community velocity model version 3. We make use of the recently developed Numerical Greens Functions method in (Wang, Strong Ground Motion Variations in Los Angeles Basin, 2007) and synthesize ground motions from a data base of 3-D Greens functions, calculated for a discretized model of the NI fault. This allows efficient simulation of arbitrary slip histories. We investigate the effects of the various slip histories on peak ground velocities and the related uncertainties in ground motion prediction for our study area. The results confirm that the fault perpendicular components of motion are dominated by directivity effects while the fault parallel component is influenced both by the slip distribution and the basin structure.
As an actor of a supply chain, seed producers must take into account the impact of their work on sustainability. This is particularly true when one works on palm oil, a highly sensitive crop which is ...questioned on its social and environmental impact. Breeders act directly on yield thus increasing profitability, while for the same production, decreasing land-use pressure. In addition, breeders act on duration of the plantations - which is critical for a perennial crop - making strategic choices selecting for lasting resistances to diseases. They can seek rustic selections, which help the work of small holders and enable them to a better social insertion in the supply chain. In the long trend, the promotion of sustainable palm oil is an excellent opportunity for palm oil seed distributors. Corporate and Social Responsibility of PalmElit, company recently created, is presented. It defines its aspirations, its values, its direct and indirect responsibilities and finally proposes an operational code of conduct. (Résumé d'auteur)
Within the framework of the 'DISCOVER' project (ANR Bio-diversity), the relationships between the bio-diversity and the functioning of pasture swards with a complex floristic composition are being ...studied in long-duration experiments, The data supply parameters and the means of evaluation for setting-up a mechanical model (GEMINI) that simulates the dynamics of the plant species and its consequences on the production and the quality of the herbage, and also on the workings of the soil. For the plants competing among themselves within the sward, GEMINI calculates the interception of light and of nitrogen, as well as the morphology of the above-ground parts and of the roots. The first modelling studies had borne on the simplified case of sown grass-clover associations. The present ambition of DISCOVER is to apply the model to swards with a complex floristic make-up, constituted by voluntary species, generally less well known. The effects of the number and of the type of species on the productivity of the pastures have been simulated, taking into account their plasticity of form and of function. Three examples of results are given. They concern : the role of the plasticity of leaf features in the response of grasses to nitrogen; the role of etiolation in the response of a dicotyledon to shade; and the role of the number of species and of functional groups in the productivity of the pasture. The applications of the model concern the role of bio-diversity in the ecological benefits of pastures with a complex floristic composition, and the simulation of the impacts of the climatic change.
La mise au point d'un modèle mécaniste permettant de simuler le fonctionnement de prairies à flore complexe est un projet ambitieux, permis par la synthèse de divers travaux de recherche en agronomie, zootechnie et écologie fonctionnelle. Les applications de ce type de modèle concernent la gestion des prairies, le rôle de la biodiversité pour les services écologiques des prairies et la simulation des impacts du changement climatique. Le projet DISCOVER étudie les relations entre la biodiversité et le fonctionnement de couverts prairiaux à flore complexe dans des expériences de longue durée, ce qui permet de paramétrer et d'évaluer un modèle mécaniste (GEMINI) lequel simule la dynamique des espèces végétales et ses conséquences pour la production végétale, la qualité de l'herbe et le fonctionnement du sol. Pour des plantes en compétition au sein du couvert, GEMINI calcule la capture de lumière et d'azote, ainsi que la morphologie des parties aériennes et des racines. Les effets du nombre et du type d'espèce pour la productivité de la prairie ont été simulés, en tenant compte de la plasticité de forme et de fonction des plantes. Des exemples de résultats sont donnés.
The phenotypic and genotypic characteristics of Staphylococcus aureus strains isolated from respiratory tract of cystic fibrosis (CF) patients were investigated. Slime production, cell-surface ...hydrophobicity, type of capsular polysaccharide, profile of heteroresistance to methicillin and Sma I restriction profiles were evaluated. S. aureus CF strains have been shown to be heterogeneous in respect to several important features. All of them were slime producing with variation in colony morphology. High or moderate cell-surface hydrophobicity (CSH) was found for, respectively, 16.2% and 83.8% strains. Thirty strains were resistant to methicillin, 60% of them showed heteroresitance and 40% were homoresistant. It was found that 59.6% of strains produced capsular polysaccharides (CP) of 5 or 8 type. Among CP5/CP8 strains, CP8 was the predominant type (81.1%). Typing of 62 CF strains by macrorestriction analysis of chromosomal DNA revealed several major types, differing in their SmaI profiles with a similarity coefficient lower than 0.4. Some of the strains isolated from the same patient at different times of hospitalization, as well as strains isolated at the same time from the relatives, were identical in their PFGE pattern.
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