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See detailEffect of Additives on Freeze-Drying and Storage of Yarrowia lipolytica Lipase.
Darvishi, Farshad; Destain, Jacqueline ULg; Nahvi, Iraj et al

in Applied Biochemistry and Biotechnology (2012)

The extracellular lipase of Yarrowia lipolytica presents numerous potentialities for biotechnological applications. This work describes the development and storage of powders obtained from supernatants ... [more ▼]

The extracellular lipase of Yarrowia lipolytica presents numerous potentialities for biotechnological applications. This work describes the development and storage of powders obtained from supernatants containing Y. lipolytica lipase by freeze-drying as downstream process that is important in obtaining a stable lipase powder with high enzymatic activity. Lipase was produced by Y. lipolytica U6 mutant strain in 20-L bioreactor. Non-concentrated cell-free culture supernatant samples were supplemented with different concentrations (0.5-1 %) of maltodextrin and glycerol as additives to freeze-drying. Effects of additives, temperature, pH, and storage time on lipase powders were determined. After addition of additives, freeze-drying yield increased 3.5-fold compared to supernatant without additive. Maltodextrin with 0.5 % concentration gave the best protection of lipase during dehydration treatment and its freeze-drying yield (77 %) is better than other formulations. Lipase powders were stored at 4 and 25 degrees C for 46 weeks without loss of lipase activity. A common impediment to the production of commercial enzyme is their low-stability aqueous solutions. The present study shows that freeze-dried lipase powders of Y. lipolytica have good stability for storage and various applications. [less ▲]

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See detailEffect of adenosine IV administration on gas exchanges and hemodynamics in unsedated calves with hypoxic vasoconstruction
Van de Weerdt, Marie-Lys; Desmecht, Daniel ULg; Vandenput, Sandrina ULg et al

in Pflügers Archiv : European Journal of Physiology (1995), 430(5), 186

Detailed reference viewed: 27 (4 ULg)
See detailEffect of Age and Maternal Dietary Addition of Omega-3 Fatty Acids EPA and DHA in Broiler Breeders on Incubation Performance
Koppenol, A.; Buyse, J.; Wang, Y. et al

in Proceedings of the 6th Combined Workshop on Fundamental Physiology and Perinatal Development in Poultry (2013)

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See detailEffect of age and testosterone on autumnal neurogenesis in male European starlings (Sturnus vulgaris)
Absil, Philippe ULg; Pinxten, R.; Balthazart, Jacques ULg et al

in Behavioural Brain Research (2003), 143(1), 15-30

The male European starling (Sturnus vulgaris) is an open-ended learner that increases its repertoire throughout life. In parallel, the volume of hi-h vocal center (HVC) is larger in older birds than in ... [more ▼]

The male European starling (Sturnus vulgaris) is an open-ended learner that increases its repertoire throughout life. In parallel, the volume of hi-h vocal center (HVC) is larger in older birds than in yearlings. We labeled with the thymidine analog 5-bromodeoxyuridine (BrdU) the cells that are generated during the fall in the brain of adult males that were 2 or more years old and in yearling males that were treated with exogenous testosterone (T) or kept intact before BrdU administration. In all subjects, the singing rate was recorded and BrdU-Iabeled cells were quantified in HVC, in proliferative areas of the ventricular zone (VZ) and in auditory regions. BrdU-containing cells were observed in all brain regions investigated. They were significantly more numerous in the VZ of the T-treated yearlings than in any other group. In older birds, a reduced number of labeled cells was specifically observed in the VZ close to the anterior commissure. No group difference was detected in auditory processing areas or in HVC. These data show for the first time a positive influence of T on the production of new cells at the VZ level in a male songbird and a decrease of this process with age. Furthermore, in T-treated birds, a correlation was observed between the HVC volume and the number of differentiated (round) BrdU-positive cell numbers in HVC on the one hand and song rate on another hand supporting the notion that singing activity is causally related to the T-induced growth of this song control nucleus. (C) 2003 Elsevier Science B.V. All rights reserved. [less ▲]

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See detailEffect of age and weight on muscle composition and carcass characteristics in young fattening bulls
Clinquart, Antoine ULg; Van Eenaeme, Christian ULg; Istasse, Louis ULg et al

in "The control of fat and lean deposition" 51th Easter School of Nottingham (1991)

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See detailEffect of age on a fractal bone texture parameter assessed by high resolution digital X Ray: a multicenter pilot study
Gadois, C.; Zegels, Brigitte; Dohuu, J. P. et al

in Osteoporosis International (2007, March), 18(Suppl.1), 102

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See detailEffect of age, feeding level and supplementation with methionine on plasma GH, IGF-1, T3 and T4 concentrations in Belgian Blue double muscled fattening females
Hornick, Jean-Luc ULg; Van Eenaeme, Christian ULg; Evrard, Pierre et al

in Symposium on growth in ruminants: basic aspects, theory and practice for the future (1998)

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See detailEffect of ageing on different egg yolk fractions on surface properties at the air–water interface
Freschi, Jérôme ULg; Razafindralambo, Hary ULg; Danthine, Sabine ULg et al

in International Journal of Food Science & Technology (2011), 46

The aim of this study was to evaluate the impact of egg ageing on the surface properties of whole and fractionated yolk at the air–water interface. Eggs were stored at 4 Cfor 24 h, 1 week and 3 weeks ... [more ▼]

The aim of this study was to evaluate the impact of egg ageing on the surface properties of whole and fractionated yolk at the air–water interface. Eggs were stored at 4 Cfor 24 h, 1 week and 3 weeks after laying.A laboratory scale fractionation process was then applied at each ageing time. Egg yolk was separated into two fractions, plasma composed of low-density lipoproteins (LDLs) and livetins, and granules formed by highdensity lipoproteins (HDLs), phosvitins and LDLg (g = granule). Moreover, recombined plasma and granules fractions were investigated to highlight a potential synergic effect on surface properties. Results have shown the main contribution of LDLs on surface properties of yolk and an improvement of granules surface properties when they are disrupted. Moreover, ageing affected surface properties differently depending on the considered fractions. Broken LDLsand disrupted granules could explain this observed behaviour. Recombined fractions showed different compression isotherms at the air–water interface than whole yolk. [less ▲]

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See detailThe effect of ageing on the recollection of emotional and neutral pictures
Comblain, Christine; D'Argembeau, Arnaud ULg; Van der Linden, Martial ULg et al

in Memory (2004), 12(6), 673-684

This study investigated age-related differences in recognition memory for emotional and neutral pictures. Younger and older participants were asked to rate pictures according to their emotional valence ... [more ▼]

This study investigated age-related differences in recognition memory for emotional and neutral pictures. Younger and older participants were asked to rate pictures according to their emotional valence, arousal, and visual complexity. Two weeks later they had to recognise these pictures and the states of awareness associated with memory were assessed with the "remember/know/guess" paradigm. We found that, although the influence of emotion on recognition accuracy (as assessed by d') was similar in both age groups, the tendency for positive and negative pictures to create a rich recollective experience was weaker in older adults. In addition., "remember" responses were more often based on a recollection of emotional reactions in older than in younger participants. We suggest that the elderly tend to focus on their feelings when confronted with emotional pictures, which could have impaired their memory for the contextual information associated with these stimuli. [less ▲]

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See detailEffect of aggregation on bacteriochlorin a triplet-state formation: A laser flash photolysis study
Damoiseau, Xavier; Tfibel, Francis; Hoebeke, Maryse ULg et al

in Photochemistry & Photobiology (2002), 76(5), 480-485

Bacteriochlorin a (BCA) is a potential photosensitizer for photodynamic therapy of cancer. It has been shown previously that the photoefficiency of the dye is mainly dependent on singlet oxygen (O-1(2 ... [more ▼]

Bacteriochlorin a (BCA) is a potential photosensitizer for photodynamic therapy of cancer. It has been shown previously that the photoefficiency of the dye is mainly dependent on singlet oxygen (O-1(2)) generation. Nanosecond laser flash photolysis was used to produce and to investigate the excited triplet state of the dye in methanol, phosphate buffer and dimiristoyl-L-alpha-phosphatidylcholine (DMPC) liposomes. The transients were characterized in terms of their absorption spectra, decay kinetics, molar absorption coefficients and formation quantum yield of singlet-triplet intercrossing. The lifetime of the BCA triplet state was measured at room temperature. The triplet-state quantum yield is quite high in methanol (0.7) and in DMPC (0.4) but only 0.095 in phosphate buffer. In the last case, BCA is in a monomer-dimer equilibrium, and the low value of the quantum yield observed was ascribed to the fact the triplet state is only formed by the monomers. [less ▲]

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See detailEffect of aggressive encounters on plasma progesterone, corticosterone and corticosteroid binding capacity
Charlier, Thierry ULg; Hammond, Geoffrey L; Soma, Kiran K

Poster (2007)

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See detailEffect of aggressive interactions on aromatase activity in discrete brain regions in wild male white-crowned sparrows
Charlier, Thierry ULg; Newman, Amy EM; Soma, Kiran K

Poster (2008)

Testosterone (T) is a critical endocrine factor involved in the activation of aggressive behaviors. In many vertebrate species, circulating T levels rapidly increase after aggressive encounters during the ... [more ▼]

Testosterone (T) is a critical endocrine factor involved in the activation of aggressive behaviors. In many vertebrate species, circulating T levels rapidly increase after aggressive encounters during the breeding season. In contrast, we recently showed that circulating T concentrations did not change in white-crowned sparrows in the late breeding season after simulated territorial intrusions. We suggested that changes in local metabolism of T might be more important than changes in systemic T levels. Neural aromatization of T into 17􀀁-estradiol (E2) often mediates the physiological and behavioral actions of T. In vertebrates, aromatase is expressed in several discrete brain regions. We hypothesized that in the late breeding season, brain aromatase is rapidly modulated after aggressive interaction, leading to changes in local concentrations of E2. Wild male white-crowned sparrows were exposed to simulated territorial intrusion with song playback and decoy (STI) or control (CON) for 30 min. STI significantly increased aggressive behaviors. Birds were then caught, rapidly bled and sacrificed. Brains were collected and rapidly frozen on dry ice. We used 0.9 mm diameter punches from 300 μm coronal sections to isolate 13 different brain nuclei. Aromatase activity was analyzed in punches from the left side of the brain, while E2 was analyzed in punches from the right side of the brain. Aromatase activity was quantified by measuring the release of tritiated water during aromatization of [1􀀁-3H]-androstenedione. As expected, aromatase activity was high in the medial preoptic area, ventromedial nucleus of the hypothalamus, hippocampus, bed nucleus of the stria terminalis, nucleus taeniae of the amygdala, and caudomedial nidopallium. Aromatase activity was low in the medial magnocellular nucleus of anterior nidopallium, HVC, Area X, nucleus robustus of the arcopallium, optic lobes, periaqueductal gray and cerebellum. Aromatase activity was not different between the STI and CON groups in any region. There were no significant correlations between aromatase activity and aggressive behaviors or endocrine measures (plasma T, progesterone, corticosterone and corticosteroid binding globulin). These data provide no evidence for rapid modulation of brain aromatase activity following aggressive interactions. It is however possible that aromatase activity is more rapidly modulated (e.g. within 5 min) and these changes were not observed in our 30 min paradigm. We are currently investigating whether local E2 is affected by aggressive interactions. [less ▲]

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See detailThe Effect of Air Height on the Pattern Formation in Liquid-Air Bilayer Convection
Johnson, Duane; Narayanan, Ranga; Dauby, Pierre ULg

in Shyy, W.; Narayanan, Ranga (Eds.) Fluid dynamics at interfaces (1999)

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See detailEffect of air-drying conditions on physical and nutritional properties of osmotically pre-treated pomegranate seeds
Bchir, Brahim ULg; Besbes, Souhail; Karoui, Romdhane et al

Poster (2012, June 01)

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See detailEffect of Air-Drying Conditions on Physico-chemical Properties of Osmotically Pre-treated Pomegranate Seeds
Bchir, Brahim ULg; Besbes, Souhail; Karoui, Romdhane et al

in Food and Bioprocess Technology (2010)

The drying of pomegranate seeds was investigated <br />at 40 °C, 50 °C and 60 °C with air velocity of 2 m/s. <br />Prior to drying, seeds were osmodehydrated in 55 °Brix <br />sucrose solution for 20 min ... [more ▼]

The drying of pomegranate seeds was investigated <br />at 40 °C, 50 °C and 60 °C with air velocity of 2 m/s. <br />Prior to drying, seeds were osmodehydrated in 55 °Brix <br />sucrose solution for 20 min at 50 °C. The drying kinetics <br />and the effects of osmotic dehydration (OD) and air-drying <br />temperature on antioxidant capacity, total phenolics, colour <br />and texture were determined. Analysis of variance revealed <br />that OD and air-drying temperature have a significant <br />influence on the quality of seeds. Both anthocyanin and <br />total phenolic contents decreased when air-drying temperature <br />increased. The radical diphenylpicril-hydrazyl activity <br />showed the lowest antioxidant activity at 60 °C. Both <br />chromatic parameters (L*, C* and h°) and browning index <br />were affected by drying temperatures, which contributed to <br />the discolouring of seeds. The final product has 22%, 20% <br />and 16% of moisture; 0.630, 0.478 and 0.414 of aw; 151, <br />141 and 134 mg gallic acid equivalent/100 g fresh matter <br />(FM) of total phenolics; 40, 24, 20 mg/100 g FM of <br />anthocyanins and 46%, 39% and 31% of antioxidant <br />activity, for drying temperatures of 40 °C, 50 °C and <br />60 °C, respectively. In view of these results, the temperature <br />of 40 °C is recommended as it has the lowest impact on <br />the quality parameters of the seeds. Differential scanning <br />calorimetry data provided complementary information on <br />the mobility changes of water during drying. Glass <br />transition temperature (Tg′) depends on moisture content <br />and as consequence, on drying conditions. In fact, Tg′ of <br />seeds dried at 60 °C (Tg′=−21 °C) was higher than those <br />dried at 50 °C (Tg′=−28 °C) or 40 °C (Tg′=−31 °C) and <br />osmodehydrated seeds (Tg′=−34 °C). During OD and <br />drying process, the texture of seeds changed. The thickness <br />of seeds shrank by 55% at 60 °C. [less ▲]

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See detailThe effect of airway occlusion and lobeline-induced hyperventilation on diaphragmatic strength in ponies
Desmecht, Daniel ULg; Art, Tatiana ULg; Rollin, Frédéric ULg et al

in Archives Internationales de Physiologie et de Biochimie (1989)

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See detailThe effect of albumen removal before incubation (embryonic protein under-nutrition) on the post-hatch performance, regulators of protein translation activation and proteolysis in neonatal broilers.
Everaert, Nadia ULg; Metayer-Coustard, Sonia; Willemsen, Hilke et al

in The British journal of nutrition (2013), 110(2), 265-74

Albumen was removed from broiler eggs before the start of incubation to induce prenatal protein under-nutrition in chicken embryos. With this method, the direct effect of protein deficiency was ... [more ▼]

Albumen was removed from broiler eggs before the start of incubation to induce prenatal protein under-nutrition in chicken embryos. With this method, the direct effect of protein deficiency was investigated, differing from mammalian models manipulating the maternal diet where indirect, hormonal effects can interfere. Based on the estimated albumen/egg weight ratio, 10 % of albumen was removed with an 18G needle, after making a hole at the sharp end of the egg with another 18G needle. Eggs were taped thereafter. The sham group underwent the same procedure, except that no albumen was removed. Control eggs did not receive any treatment. The removal of albumen decreased both embryonic and post-hatch body weight up to day 7 compared with the control group. On embryonic day 18, embryos from the albumen-deprived group had higher plasma uric acid levels compared with the sham (P= 0.016) and control (P= 0.009) groups. Moreover, a lower plasma amino acid concentration was observed at hatch compared with the sham (P= 0.038) and control (P= 0.152) groups. These findings indicate an altered protein metabolism. At hatch, a higher mRNA expression of muscle ring finger-1 (MuRF1), a gene related to proteolysis, was observed in albumen-deprived chicks compared with the control and sham chicks, together with an up-regulated expression of atrogin-1 (another atrogene) at this time point in the male protein-deficient chicks. These findings suggest that muscle proteolysis is transiently increased by the removal of albumen before the start of incubation. No evidence was found for altered protein synthesis capacity and translational efficiency in albumen-deprived chicks. [less ▲]

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See detailEffect of alumina and titanium nitrides inclusions on mechanical properties in high alloyed steels
Lecomte-Beckers, Jacqueline ULg; Tchoufang Tchuindjang, Jérôme; Gfhiri, Rachid et al

in Proceedings of the MSMF-3 International Conference (2001)

every commercial steel product in varying amounts. Since inclusions significantly influence properties and behaviour of materials and at the same time give indications on the quality of the steel, it is ... [more ▼]

every commercial steel product in varying amounts. Since inclusions significantly influence properties and behaviour of materials and at the same time give indications on the quality of the steel, it is quite interesting to precise their nature and their origin. In this paper concerning a project involved in the COST 517 framework, studied alloys are high alloy steels. The raw materials were obtained from the conventionally electrical cast ingot and the Electro Slag Refining processes. The purpose is to compare various inclusions produced by these different processes and their effect on the mechanical properties. The raw material because of the melting processes themselves, leads to a product with a good to a great cleanliness, and tiny inclusions, which are haphazardly distributed. The actual ASTM E45 chart seems to be inappropriate, as the inclusions founded are too small in size. Therefore, we manage to develop a specific procedure for the study of such inclusions. The different types of inclusions encountered are oxides, titanium nitrides, and manganese sulphides. Studying the effect on mechanical properties, oxides often seem to initiate fatigue fracture. [less ▲]

Detailed reference viewed: 82 (4 ULg)