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See detailProduction line real time near infrared (NIR) monitoring
Mantanus, Jérôme ULg; Ziemons, Eric ULg; Streel, Bruno et al

Conference (2009, September)

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See detailLa production littéraire des Belges francophones durant l’entre-deux-guerres. Examen d’un premier inventaire
Dozo, Björn-Olav ULg

in Mémoires du Livre = Studies in Book Culture (2010), 1(2),

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See detailProduction locale des antisérums de groupe sanguin ABO
Bamoleke Sefu, Anaclet; Tshiband-a-Tshish, Alphonse; Munlemvo Mavanga, Nana ULg et al

in Immuno-Analyse & Biologie Spécialisée [=IBS] (2012), 27

Detailed reference viewed: 48 (8 ULg)
See detailProduction of L-[18F]fluoroamino acids for protein synthesis: overview and recent developments in nucleophilic synthesis
Lemaire, Christian ULg

in PET studies on Amino Acid Metabolism and Protein Synthesis (1993)

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See detailProduction of 3-hydroxy-γ-decalactone, the precursor of two decenolides with flavouring properties, by the yeast Yarrowia lipolytica
Escamilla Garcia, E.; Aguedo, Mario ULg; Gomes, N. et al

in Journal of Molecular Catalysis B : Enzymatic (2009), 57(1-4), 22-26

3-Hydroxy-γ-decalactone is the precursor of dec-2 and dec-3-en-4-olides which are valuable aroma compounds not yet produced. To promote the accumulation of this lactone, the yeast Yarrowia lipolytica was ... [more ▼]

3-Hydroxy-γ-decalactone is the precursor of dec-2 and dec-3-en-4-olides which are valuable aroma compounds not yet produced. To promote the accumulation of this lactone, the yeast Yarrowia lipolytica was placed in different environmental conditions aiming at altering β-oxidation fluxes. The concentration of substrate, pH, aeration and dissolved oxygen level were modified. We observed an important accumulation at low aeration (0.40 molar yields) and, to a lesser extent, at lower pH (0.15). As oxygen played a key-role, we evaluated its effect at fixed dissolved oxygen and at the pH which was the most favourable to the biotransformation (pH 4.5). At 5% and 30% dissolved oxygen, yields reached 0.50. β-Oxidation fluxes are very dependent on the presence of oxygen and conditions of accumulation of 3-hydroxy-γ-decalactone with very high yields were identified. These results are an important step in the production of the two decenolides. Moreover, they show the high dependence of β-oxidation fluxes on environmental conditions and relate these conditions to the accumulation of intermediates, results that are of interest to all the processes using yeast on lipids or alkanes. © 2008 Elsevier B.V. All rights reserved. [less ▲]

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See detailProduction of 4-hydroxydecanoic acid, a g-decalactone precursor, by the psychrophilic yeast Rhodotorula aurantiaca A16.
Belot, J. L.; Lognay, Georges ULg; Marlier, M. et al

Poster (1997, August)

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See detailProduction of a high percentage of male offspring with a natural androgen, 11 beta-hydroxyandrostenedione (11 beta OHA4), in Florida red tilapia
Desprez, D.; Geraz, E.; Hoarea, M. C. et al

in Aquaculture (2003), 216(1-4), 55-65

This paper reports the effects of a natural androgen, 11beta-hydroxyandrostenedione (11betaOHA4), on sex-reversed fry of the Florida red tilapia. In a first approach, the optimal dosage and duration were ... [more ▼]

This paper reports the effects of a natural androgen, 11beta-hydroxyandrostenedione (11betaOHA4), on sex-reversed fry of the Florida red tilapia. In a first approach, the optimal dosage and duration were determined in the laboratory. The sex-reversal treatment was applied on post-yolksac stage fry (10 days after fertilisation at 27degreesC. Dosages of 20, 30, 40 and 50 mg of 11betaOHA4 kg(-1) of food were used during periods ranging from 10 to 35 days. Dosages of 40 or 50 mg of 11betaOHA4 kg(-1) of food during 21-35 days significantly increased the male percentage in sex-reversed groups in comparison to control groups. A lower but still significant deviation of the male percentage was observed when a dosage of 40 mg kg-1 was given during at least 28 days. Lower dosages did not significantly affect the sex ratio of treated groups. Based on the results of these observations, a follow-up study was conducted to evaluate the efficiency of this natural androgen for an intensive production of sex-reversed fry. Optimal dosage (50 mg kg-1) and treatment duration (28 days) were applied to increasing stocking density of fry (8000-11,000 fish m(-2)), producing a mean male percentage of 99.1% on the 510,000 treated fry. This study demonstrates the masculinizing efficiency of 11betaOHA4 in Florida red tilapia. Interest of a natural androgen, used in sex-reversal treatment, is discussed, particularly for the Florida red tilapia strain. (C) 2003 Elsevier Science B.V. All rights reserved. [less ▲]

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See detailProduction of a novel mixture of mycosubtilins by mutants of Bacillus subtilis.
Bechet, Max; Castera-Guy, Joany; Guez, Jean-Sebastien et al

in Bioresource technology (2013), 145

Using promoter exchange and gene knock-out strategies, two mutant strains, the so-called BBG116 and BBG125, were constructed from Bacillus subtilis wild-type strain ATCC 6633, a surfactin and mycosubtilin ... [more ▼]

Using promoter exchange and gene knock-out strategies, two mutant strains, the so-called BBG116 and BBG125, were constructed from Bacillus subtilis wild-type strain ATCC 6633, a surfactin and mycosubtilin producer. Compared to the parental strain, both mutants overproduced constitutively mycosubtilin, while BBG125 had lost the ability to synthesize surfactin. Surprisingly, BBG125 was found to produce about 2-fold less mycosubtilin than BBG116 despite an expected higher availability of the cytoplasmic precursors and cofactors pool for biosynthesis. Further physiological characterization of BBG125 also highlighted: (i) a strong influence of temperature on mycosubtilin biosynthesis in BBG125 with a maximal productivity observed at 22 degrees C, compared to 15 and 30 degrees C; (ii) substantial changes in fatty acid profiles and thereby in mycosubtilin isoforms, compared to the wild-type strain; and (iii) the presence of five novel mycosubtilin isoforms. The antifungal activities of the new mix were higher than or equal to those of purified isoforms. [less ▲]

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See detailProduction of active oxygen species by isolated human chondrocytes.
Henrotin, Yves ULg; Deby-Dupont, G.; DEBY, C. et al

in British Journal of Rheumatology (1993), 32(7), 562-7

The ability of isolated human chondrocytes to produce active oxygen species has been investigated. The two methods for determining H2O2 and hydroxyl radicals (.OH) production were, by a fluorimetric ... [more ▼]

The ability of isolated human chondrocytes to produce active oxygen species has been investigated. The two methods for determining H2O2 and hydroxyl radicals (.OH) production were, by a fluorimetric method (production of dichlorofluorescein from a precursor in the presence of horseradish peroxidase and H2O2) and by a chromatographic method (measurement of ethylene production from gamma-methiol-keto-butyric acid after .OH attack). Chondrocytes were tested, both with and without activation by phorbol myristate acetate (PMA: 10(-6) M), in the presence of Ca2+ (1 x 10(-4) M) and Mg2+ (2 x 10(-4) M) or after variable periods of anoxia under nitrogen (4 to 12 h) followed by reoxygenation (with 95% O2, 5% CO2). Under these experimental conditions, the PMA-excited chondrocytes produced from 80 to 180 nmol of hydrogen peroxide per 1 x 10(6) cells and chondrocytes subjected to anoxia-reoxygenation produced up to 1700 nmol H2O2 per 1 x 10(6) cells. The hydroxyl radical production by PMA or anoxia-reoxygenation excited cells reached 600% of the production of non-excited cells and 1300% when they were subjected to successive stimulations by PMA and anoxia-reoxygenation. The possible pathological significance of these observations is discussed. The results indicate that stimulated human chondrocytes are capable of producing active oxygen species which could play a major role in joint inflammation and cartilage damage. [less ▲]

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See detailProduction of adsorbent materials from dried residual sludges
Fostroy, Philippe; Salmon, Thierry ULg; Crine, Michel ULg et al

Poster (2008, September)

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See detailProduction of alarm pheromone by developing aphids varies in response to their social environment
Verheggen, François ULg; Mescher, Mark; Haubruge, Eric ULg et al

Conference (2008)

Aphid alarm pheromone—the volatile sesquiterpene (E)-β-farnesene (Eβf) in most species—is released in response to predation and other stresses and typically causes nearby aphids who receive the signal to ... [more ▼]

Aphid alarm pheromone—the volatile sesquiterpene (E)-β-farnesene (Eβf) in most species—is released in response to predation and other stresses and typically causes nearby aphids who receive the signal to cease feeding, drop from their host plant, and disperse. Because aphid alarm pheromone confers apparent fitness benefits on recipients while its production and release likely entail costs for the emitting aphid, it could be adaptive for aphids to regulate their Eβf production in response to variation in the social environment. To explore this possibility we compared the production of Eβf by Acyrthosiphon pisum (Harris) individuals reared from first-instar larvae to the adult stage in isolation to that of individuals reared among conspecifics or among individuals of a different aphid species, Myzus persicae (Sulzer). Levels of EβF produced in each treatment were assayed by GC-FID quantification of EβF in volatiles collected from crushed aphids. Production of EβF by A. pisum reared in isolation (14.4ng/aphid) was significantly lower than that of aphids reared in a colony of conspecifics (49.1ng/aphid), reared in a M. persicae colony (31.5ng/aphid) or reared among conspecifics of another aaphid clone (52.7ng/aphid). Though A. pisum individuals in our experiments produced less EβF when reared among M. persicae than among conspecifics, this difference was not statistically significant. In a separate experiment we reared A. pisum individuals in isolation and exposed them to the odor of conspecifics. Under these conditions, EβF production was similar to that of aphids reared among conspecifics, suggesting that aphids use volatile cues to assess their social environment and regulate their production of alarm pheromone accordingly. [less ▲]

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See detailProduction of alarm pheromone by developing aphids varies in response to their social environment
Verheggen, François ULg; Haubruge, Eric ULg; Demoraes, Consuelo et al

Poster (2008)

Aphid alarm pheromone—the volatile sesquiterpene (E)-β-farnesene (Eβf) in most species—is released in response to predation and other stresses and typically causes nearby aphids who receive the signal to ... [more ▼]

Aphid alarm pheromone—the volatile sesquiterpene (E)-β-farnesene (Eβf) in most species—is released in response to predation and other stresses and typically causes nearby aphids who receive the signal to cease feeding, drop from their host plant, and disperse. Because aphid alarm pheromone confers apparent fitness benefits on recipients while its production and release likely entail costs for the emitting aphid, it could be adaptive for aphids to regulate their Eβf production in response to variation in the social environment. To explore this possibility we compared the production of Eβf by Acyrthosiphon pisum (Harris) individuals reared from first-instar larvae to the adult stage in isolation to that of individuals reared among conspecifics or among individuals of a different aphid species, Myzus persicae (Sulzer). Levels of EβF produced in each treatment were assayed by GC-FID quantification of EβF in volatiles collected from crushed aphids. Production of EβF by A. pisum reared in isolation (14.4ng/aphid) was significantly lower than that of aphids reared in a colony of conspecifics (49.1ng/aphid), reared in a M. persicae colony (31.5ng/aphid) or reared among conspecifics of another aaphid clone (52.7ng/aphid). Though A. pisum individuals in our experiments produced less EβF when reared among M. persicae than among conspecifics, this difference was not statistically significant. In a separate experiment we reared A. pisum individuals in isolation and exposed them to the odor of conspecifics. Under these conditions, EβF production was similar to that of aphids reared among conspecifics, suggesting that aphids use volatile cues to assess their social environment and regulate their production of alarm pheromone accordingly. [less ▲]

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See detailProduction of alarm pheromone in aphids and perception by ants and natural enemies
Verheggen, François ULg

Doctoral thesis (2008)

Most Aphidinae species produce and use (E)-ß-farnesene (Eßf) as an alarm pheromone. This sesquiterpene is released by individuals under attack by a predator, and nearby aphids exhibit a variety of alarm ... [more ▼]

Most Aphidinae species produce and use (E)-ß-farnesene (Eßf) as an alarm pheromone. This sesquiterpene is released by individuals under attack by a predator, and nearby aphids exhibit a variety of alarm behaviours. This PhD thesis aims to better understand how aphids manage their production and emission of alarm pheromone (Chapter IV). We also wanted, in a second step, to improve our knowledge on the roles that Eßf could play in the relationships that aphids have with their predators (Chapter V) and tending ants (Chapter VI), in order to better pinpoint the problem in this very tough context. The aphid predators have indeed a real advantage to be able to use the odorant cues emitted by their prey, to locate them and to select an adequate oviposition site. Ants establish with certain aphid species mutualistic relationships, which occurrence could be facilitated by the use of aphids’ odours. In Chapter IV, we have highlighted that aphid colonies non subjected to attack by predators release constantly small quantities of Eßf in their headspace, which means that this molecule could have additional roles than just acting as an alarm pheromone. In a second study, we demonstrated that the release of Eßf was not contagious, and therefore that a non stressed aphid receiving the alarm signal does not release additional Eßf. Since the production of alarm pheromone is likely to entail physiological cost, we tested and validated the hypothesis that aphids regulate their Eßf production according to their social environment. In Chapter V, we studied the ability of the hoverfly predator Episyrphus balteatus (Diptera, Syrphidae) to be used as biological control agent against aphids infesting tomato plants (Lycopersicon esculentum). After identifying the odours emitted by aphid infested plants, we have demonstrated that although this Diptera is able to perceive all the odours released by the system, it mainly uses Eßf to select its oviposition site. However, the E. balteatus larvae are not adapted to the architecture of tomato plants. We also showed that the Asian ladybeetle Harmonia axyridis (Coleoptera, Coccinellidae) olfaction was adapted to the perception of Eßf and that this beetle is also attracted by this sesquiterpene. Finally, in Chapter VI, we characterized the benefits accruing to aphid populations that have established mutualistic relationships with Lasius niger (Hymenoptera, Formicidae), and have demonstrated the role of Eßf and honeydew, respectively in locating aphid colonies and in the persistence of the mutualism. [less ▲]

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See detailProduction of anionic extracellular polysaccharide by Enterobacter A47 using cheese whey as feedstock
Antunes, S; Alves, V.D.; Grandfils, Christian ULg et al

Conference (2013, September)

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See detailProduction of anti-PMSG antibodies and its relation to the productivity of rabbit does
Lebas, F.; Theau-Clement, M.; Remy, Benoît ULg et al

in World Rabbit Science (1996), 4(2), 57-62

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See detailProduction of beta-galactosidase from a thermotolerant yeast strain.
Thonart, Philippe ULg; Baijot, B.; Crahay, V.

in Third European Congress on Biotechnology. Munchen, Federal Republic ofGermany, 10-14 September 1984. Vol. I. (1984)

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See detailProduction of biodegradable polyesters from industrial and agricultural by-products
de Almeida, C.; Calvaheiro, J.; Raposo, R. et al

Conference (2011, September)

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See detailProduction of Biopolymers from Sugar Beet Pulp
Meyer, Laurence ULg; Paquot, Michel ULg; Dubois, Philippe

Poster (2009, May)

Sugar beet pulp is an important by-product of the sugar industry. In order to make the most of this waste, pectin extraction can constitute an economical solution. Pectin is commonly used in food industry ... [more ▼]

Sugar beet pulp is an important by-product of the sugar industry. In order to make the most of this waste, pectin extraction can constitute an economical solution. Pectin is commonly used in food industry as a gelling agent. However, in the present study another use of pectin is considered: its potential embedding into biodegradable polymer films which can further be used in plastic industry. At first, different pectin extraction methods have been developed on sugar beet pulp in order to obtain four different types of pectins characterized at the same time by their molecular weight degree of esterification. Acidic extraction leads to pectin of high molecular weight and high degree of esterification. From this pectin, a de-esterification and a de-polymerization allow us to obtain, respectively, a pectin of high molecular weight and low degree of esterification and a pectin of low molecular weight and high degree of esterification. On the other hand, a basic extraction leads to pectin of low molecular weight and degree of esterification. Preliminary, tests have been conducted on mixes comprising 5, 10, 15, 20 % of commercial pectin and PLA (polylactic acid) or PBAT (Polybutylen-adipate terephtalate). In all cases, the products were not stable and therefore the use of a compatibilizing agent was required. Glycerol and D-Sorbitol were thus studied for that purpose, in mixing ratios between 40-80 % with commercial pectin. The best mechanical properties (Young modulus; yield stress and yield strain) were obtained with the pectin/sorbitol 50/50 mix. This proportion was then used with our different sugar beet pulp extracted pectins to produce PLA/pectin/Sorbitol 50/25/25 formulations. The best mechanical properties were reached with the low molecular weight end degree of esterification pectin. Indeed, the relative small size of this pectin with the lack of esterified groups enables interactions between pectin chains plastified by sorbitol and PLA. These interactions lead to a better cohesion of the high pectic content biomaterial. [less ▲]

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