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See detailOptimisation of a semiochemical slow-release alginate formulation attractive towards Aphidius ervi Haliday parasitoids
Heuskin, Stéphanie ULg; Lorge, Stéphanie; Godin, Bruno et al

in Pest Management Science (2011)

BACKGROUND: Optimisation of alginate formulations is described in order to develop semiochemical (E-β-farnesene and E-β-caryophyllene) slow-release devices in biological control approaches by attracting ... [more ▼]

BACKGROUND: Optimisation of alginate formulations is described in order to develop semiochemical (E-β-farnesene and E-β-caryophyllene) slow-release devices in biological control approaches by attracting predators and parasitoids of aphids. Various formulation criteria were optimised with respect to semiochemical encapsulation capacity. Moreover, the optimised formulation was characterised by texturometry and confocal microscopy. The slow-release rates of semiochemicals were calculated in laboratory controlled conditions. The attractiveness of semiochemical formulations towards Aphidius ervi was demonstrated by olfactometry. RESULTS: Two major parameters were highlighted in encapsulation optimisation: the type of alginate (Sigma L) and the type of crosslinker ion (Ca2+). Other formulation parameters were optimised: ionic strength (0.5M), Ca2+ (0.2 M) and alginate (1.5%) concentrations and the maturation time of beads in CaCl2 solution (48 h). After physical characterisation of beads, semiochemical slow-release measurements showed that alginate formulations were efficient sesquiterpene releasers, with 503 μg of E-β-farnesene and 1791 μg of E-β-caryophyllene totally released in 35 days. The efficiency of semiochemical alginate beads as attractants for female parasitoids was demonstrated, with high percentages of attraction for semiochemical odours (88 and 90% for E-β-farnesene and E-β-caryophyllene respectively) and significant statistical results. CONCLUSION: Semiochemical alginate beads can be considered as efficient slow-release systems in biological control. These formulations could be very useful to attract aphid parasitoids on crop fields. [less ▲]

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See detailOptimisation of blocked designs in fMRI studies
Maus, Bärbel ULg; van Breukelen, G. J. P.; Goebel, R. et al

Poster (2009)

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See detailOptimisation of blocked designs in fMRI studies
Maus, Bärbel ULg; van Breukelen, G. J. P.; Goebel, R. et al

Poster (2008)

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See detailOptimisation of culture conditions for biological hydrogen production by Citrobacter freundii CWBI952 in batch, sequenced-batch and semicontinuous operating mode
Hamilton, Christopher ULg; Hiligsmann, Serge ULg; Beckers, Laurent ULg et al

in International Journal of Hydrogen Energy (2010), 35

Investigations were carried out to determine the effect of the pH, the nitrogen source, iron and the dilution rate (h 1) on fermentative hydrogen production from glucose by the newly isolated strain ... [more ▼]

Investigations were carried out to determine the effect of the pH, the nitrogen source, iron and the dilution rate (h 1) on fermentative hydrogen production from glucose by the newly isolated strain Citrobacter freundii CWBI952. The hydrogen production rate (HPR), hydrogen yield, biomass and soluble metabolites were monitored at 30 C in 100 mL serum bottles and in a 2.3 L bioreactor operated in batch, sequenced-batch and semicontinuous mode. The results indicate that hydrogen production activity, formate biosynthesis and glucose intake rates are very sensitive to the culture pH, and that additional formate bioconversion and production of hydrogen with lower biomass yields can be obtained at pH 5.9. In a further series of cultures casein peptone was replaced by (NH4)2SO4, a low cost alternative nitrogen source. The ammonia-based substitute was found to be suitable for H2 production when a concentration of 0.045 g/L FeSO4 was provided. Optimal overall performances (ca. an HPR of 33.2 mL H2/L h and a yield of 0:83 molH2 =molglucose) were obtained in the semicontinuous culture applying the previously optimized parameters for pH, nitrogen, and iron with a dilution rate of 0.012 h 1 and degassing of biogas by N2 at a 28 mL/min flow rate. [less ▲]

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See detailOptimisation of degradable microcarriers for tissue engineering
Lombart, François ULg; Sevrin, Chantal ULg; Flebus, Luca ULg et al

Conference (2013, April 09)

Detailed reference viewed: 23 (2 ULg)
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See detailOptimisation of exercise training in clinical practice for claudicants patients.
Magne, Julien ULg; Boccalon, H; Bouley, M et al

Conference (2003)

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See detailOptimisation Of Expression And Immobilized Metal Ion Affinity Chromatographic Purification Of Recombinant (His)(6)-Tagged Cytochrome P450 Hydroperoxide Lyase In Escherichia Coli
Delcarte, J.; Fauconnier, Marie-Laure ULg; Jacques, P. et al

in Journal of Chromatography B-Analytical Technologies In the Biomedicaland Life Sciences (2003), 786(1-2),

Fatty acid hydroperoxide lyase (HPL) is a cytochrome P450 acting on fatty acid’s hydroperoxides in many plants. The optimisation of the expression of recombinant (His) -tagged HPL in Escherichia coli is ... [more ▼]

Fatty acid hydroperoxide lyase (HPL) is a cytochrome P450 acting on fatty acid’s hydroperoxides in many plants. The optimisation of the expression of recombinant (His) -tagged HPL in Escherichia coli is described: the highest HPL 6 production yield were obtained with TB medium supplemented with 2.5 mM d-aminolevulinic acid and 0.5 mM IPTG. For the first time, the time course expression of a plant P450 in a bench-scale fermentor is detailed and the amount of recombinant HPL production is 16.3 mg/ l. The UV–Visible spectrum of the recombinant (His) -tagged HPL have been recorded after a Ni -based affinity chromatography (IMAC). [less ▲]

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See detailOptimisation of extraction of phenolics and antioxidants from black currant leaves and buds and of stability during storage
Tabart, Jessica ULg; Kevers, Claire ULg; Sipel, Arnaud ULg et al

in Food Chemistry (2007), 105(3), 1268-1275

Health benefits of a diet rich in fruits and vegetables are attributed in part to their contents of phenolics and other antioxidant compounds. In this research, the extraction of phenolics and antioxidant ... [more ▼]

Health benefits of a diet rich in fruits and vegetables are attributed in part to their contents of phenolics and other antioxidant compounds. In this research, the extraction of phenolics and antioxidant compounds from black currant was optimised for different plant organs. The extraction solvent affected yield: aqueous acetone was better than methanol and acetate or glycine buffer. In aqueous buffer, maximum yields of total phenolics and antioxidant activities were obtained at pH 3. Extraction from lyophilised materials yielded extracts with higher phenolic contents and antioxidant activities. Stability of extracts made with acetate or glycine buffer was limited while the use of a mixture of acetone/acetic acid/water for extraction allowed a high phenolic content and antioxidant capacity in dry extract to be maintained for several months. This type of extract could be incorporated in functional food, beverage or dietary supplement. (c) 2007 Elsevier Ltd. All rights reserved. [less ▲]

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See detailOptimisation of hydroelectric power stations operations with WOLF package
Erpicum, Sébastien ULg; Archambeau, Pierre ULg; Dewals, Benjamin ULg et al

in Repp, K.; Westeren, T.; Sandlund, O. T. (Eds.) et al Proceedings of the 5th International Conference on Hydropower - The backbone of sustainable energy supply (2005)

For years, original free-surface flow solvers have been developed and continuously improved by the Laboratory of Applied Hydrodynamics and Hydraulic Constructions (HACH) at the University of Liège. The ... [more ▼]

For years, original free-surface flow solvers have been developed and continuously improved by the Laboratory of Applied Hydrodynamics and Hydraulic Constructions (HACH) at the University of Liège. The resulting fully integrated WOLF computation package allows engineers to accurately study a very wide range of various free surface flows, from hydrological runoff (WOLF HYDRO) and river propagation (WOLF 1D) to extreme erosive flows on realistic mobile topography (WOLF 2D), such as gradual dam breaching processes. All the finite volume models, process oriented, use efficient and original numerical methods to solve free surface flows equations. Each code handles general multiblock meshes, dealing with natural topography, dry and wet cells and mobile bed simultaneously, for any unsteady situation with mixed regimes and moving hydraulic jumps. The interactive and unique user-interface, with high performance pre- and post-processing, allows monitoring 3-D large-scale runs graphically while they proceed, as well as generating 3D videos. In addition, powerful optimisation capabilities based on the Genetic Algorithms technique (WOLF AG) are implemented within WOLF, interconnecting all the package components. An efficient tool is thus available to calibrate physical parameters in any of the models and to manage any problem of optimisation with the different solvers. In this paper, the numerical optimisation process of the system of hydroelectric power stations installed on a 60 km long section of the rivers Amblève and Warche in Belgium is presented in detail. The river network is modelled in quasi-2D using real natural topographic data on almost 1,100 finite volumes. In a first step, the hydrological balance is closed using the solver WOLF HYDRO. Roughness coefficients are calibrated from water level and discharge field measurements. Secondly, the hydroelectric production is maximised by an automatic calibration of the parameters of the hydrograph released in the network at the upstream dam. This approach leads to a substantial gain in hydroelectric production, brings significant financial benefits and deals with all management and security criteria of the river network. [less ▲]

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See detailOptimisation of new biodegradable microcarriers tailored for tissue engineering
Tsoy, A; Sevrin, Chantal ULg; Kottgen, C et al

Poster (2010, October 07)

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See detailOptimisation of new biodegradable microcarriers tailored for tissue engineering
Tsoy, A; Sevrin, Chantal ULg; Köttgen, Cindy et al

Conference (2010, December 10)

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See detailOptimisation of new biodegradable microcarriers tailored for tissue engineering
Demina, T; Akopova, T; Tsoy, A et al

Poster (2012, April 18)

Detailed reference viewed: 4 (1 ULg)
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See detailOptimisation of Panax ginseng liquid cell cultures for biomass accumulation and ginsenoside production.
Kevers, Claire ULg; Bare, Gislain; Gaspar, Thomas ULg et al

in HVOSLEF-EIDE, Anne Kathrine; PREIL, Walter (Eds.) Liquid Culture Systems for in vitro Plant Propagation (2005)

Solid calli and derived liquid cell cultures were initiated from one-year-old roots of Panax ginseng CA Meyer. Half-strength Murashige and Skoog medium supplemented classically with an auxin and a ... [more ▼]

Solid calli and derived liquid cell cultures were initiated from one-year-old roots of Panax ginseng CA Meyer. Half-strength Murashige and Skoog medium supplemented classically with an auxin and a cytokinin did not appear favourable for biomass accumulation nor for a high ginsenoside content. Changes in the levels of mineral nutrients, sucrose and growth regulators were preliminary investigated here to improve growth and ginsenoside production in liquid cultures. The hypothesis that ginseng cells released growth inhibitors in the medium was not supported by the results obtained in experiments involving frequent transfers to fresh growth medium [less ▲]

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See detailOptimisation of poly(2-(dimethylamino)ethyl methacrylate)-co-poly(ethyleneglycol) /DNA complexes designed for cell transfection
Grandfils, Christian ULg; Emonds-Alt, J

in Proceeding BRG XIIth International Workshop on Bioencapsulation Meeting (2004, September 24)

Detailed reference viewed: 12 (0 ULg)
See detailOptimisation of retrieval strategies using Jungfraujoch high-resolution FTIR observations for long-term trend studies and satellite validation.
Mahieu, Emmanuel ULg; Servais, Christian ULg; Duchatelet, Pierre ULg et al

in Burrows, J.; Borrell, P. (Eds.) Observing Tropospheric Trace Constituents from Space. (2007)

Detailed reference viewed: 4 (2 ULg)
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See detailOptimisation of SFE method on-line coupled to FT-IR spectroscopy for the real-time monitoring of the extraction of tagitinin C in T-diversifolia
Ziemons, Eric ULg; Mbakop, N. W.; Rozet, Eric ULg et al

in Journal of Supercritical Fluids (2007), 40(3), 368-375

The monitoring in real time of dynamic extractions of tagitinin C from Tithonia diversifolia leaves was carried out with a home made high-pressure fiber optic cell which coupled a supercritical fluid ... [more ▼]

The monitoring in real time of dynamic extractions of tagitinin C from Tithonia diversifolia leaves was carried out with a home made high-pressure fiber optic cell which coupled a supercritical fluid extractor with carbon dioxide as the extraction medium and a FT-IR spectrometer equipped with a mercury cadmium telluride detector (MCT). The shape of extraction curves obtained during the monitoring was used to decide when to stop the supercritical fluid extraction (SFE). No significant density dependence of the molar absorption coefficient or wavenumber of the C=O stretching vibration (v(C=O)) of tagitinin C at 1668 cm(-1) was noticed. The physical characteristics of SCCO2 governing the extraction yield of the active component from leaves were optimized by means of a central composite design (CCD). The studied variables were temperature (40, 60 and 80 degrees C) and pressure (8.0, 14.0 and 20.0 MPa) of the supercritical fluid. The composition profile of T diversifolia extracts obtained by SFE was investigated in the range from 3400 to 2600 cm-1 according to the pressure and temperature conditions of SCCO2. The qualitative approach of the extracts composition was accomplished through the CH stretching vibrations of components. [less ▲]

Detailed reference viewed: 46 (3 ULg)