Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
Full Text
Peer Reviewed
See detailThe effect of exposure to drugs on the processing of natural rewards
Anselme, Patrick ULg

in Neuroscience & Biobehavioral Reviews (2009), 33(3), 314-335

Why does moderate exposure to a drug reward make natural rewards increasingly attractive to organisms, whereas prolonged exposure to the same drug reward has the opposite effect? The paradox behind that ... [more ▼]

Why does moderate exposure to a drug reward make natural rewards increasingly attractive to organisms, whereas prolonged exposure to the same drug reward has the opposite effect? The paradox behind that question remains unsatisfactorily captured by current theories of addiction. The incentivesensitisation theory is viewed as a promising approach to this paradox, although it provides no mechanism to explain the decrease in interest of natural rewards as time exposure to a drug increases. To attempt to remedy this problem, I describe a model called the anticipatory dynamics model (ADM) that suggests a pivotal role of anticipation and attention inmotivational interactions. In addition to relying on strong neuropsychopharmacological data, the ADM provides an original conception of motivational specificity. The ADM is an extension of the incentive-sensitisation theory that hypothesizes how drugs interact with natural rewards. It has not been tested empirically, although a possible experiment to test two predictions in the field of addiction is presented. [less ▲]

Detailed reference viewed: 19 (2 ULg)
Full Text
Peer Reviewed
See detailEffect of extraction conditions on the yied and purity of ulvan extracted from Ulva lactuca
Yaich, Hela; Garna, Haikel; Besbes, Souhail et al

in Food Hydrocolloids (2013)

A study of the influence of extraction conditions (pH: 1.5 and 2; temperature: 80 °C and 90 °C; extraction time: 1-3 h), on the yield, chemical composition and purity of the sulphated cell wall ... [more ▼]

A study of the influence of extraction conditions (pH: 1.5 and 2; temperature: 80 °C and 90 °C; extraction time: 1-3 h), on the yield, chemical composition and purity of the sulphated cell wall polysaccharides ulvan, extracted from the green seaweed Ulva lactuca and precipitated by alcohol is carried out. The alcohol precipitate yields varied from 21.68% to 32.67% (%dw/dw) depending on the pH. At pH 2, the alcohol precipitate yields and the uronic acid recovery from extract juice are higher than those obtained at pH 1.5. Other compounds than ulvan such as cellulose, hemicellulose, proteins and ash are solubilized from the cell walls of Ulva lactuca at both pH, and they are precipitated with alcohol. The alcohol precipitate obtained from different extraction conditions has high uronic acid (20.37%-23.60%) and neutral sugar content (20.09%-29.12%), especially when the conditions (pH, temperature) are drastic. It contains rhamnose (13.35%-15.59%), glucose (2.90%-10.97%), and xylose (2.36%-2.73%). A decrease in the molecular weight of ulvan was observed at acid pH, and for long extraction times. The presence of proteins (1.94%-2.32%) and inorganic material (33.36%-47.15%) in alcohol precipitate prove the lower purity of ulvan extracted and shows that ulvan precipitation with ethanol is not specific. © 2012 Elsevier Ltd. [less ▲]

Detailed reference viewed: 67 (5 ULg)
Full Text
Peer Reviewed
See detailEffect of extraction conditions on the yield and purity of apple pomace pectin precipitated but not washed by alcohol
Garna, Haikel; Mabon, Nicolas; Robert, Christelle et al

in Journal of Food Science (2007), 72(1), 1-9

A study of the influence of extraction condition (pH: 1.5 to 2; temperature: 80 to 90 degrees C; extraction time: 1 to 3 h), on the yield and purity of apple pomace pectin without elimination of ... [more ▼]

A study of the influence of extraction condition (pH: 1.5 to 2; temperature: 80 to 90 degrees C; extraction time: 1 to 3 h), on the yield and purity of apple pomace pectin without elimination of impurities by alcohol washing was carried out. The alcohol precipitate yields varied from 2.9% to 8.9% depending on the pH. At pH 1.5, these yields were higher than those obtained at pH 2 contrary to the galacturonic acid purity (%w/w). Compounds other than pectins were solubilized from the cell walls of apple pomace at pH 1.5, and they were precipitated with alcohol. The apple pectins obtained from the different extraction procedures were highly methylated (54.5% to 79.5%), especially when the conditions (temperature, pH) were drastic. Similar conclusions can be drawn for the neutral sugar content that decreased at pH 1.5 (arabinose, xylose, and galactose) or at the highest temperatures and extraction times (arabinose and galactose). The phenomenon of demethylation and pectin degradation of neutral sugars chains can be observed at acid pH, and long extraction times. The presence of high quantities of mannose or fructose, glucose, and xylose in the alcohol precipitate showed that pectin precipitation with ethanol was not specific. [less ▲]

Detailed reference viewed: 100 (5 ULg)
Full Text
Peer Reviewed
See detailEffect Of Extraction Conditions On The Yield, Purity And Surface Properties Of Sugar Beet Pulp Pectin Extracts
Yapo, Marcel Beda; Robert, Christelle; Etienne, Isabelle et al

in Food Chemistry (2007), 100(4), 1356-1364

Detailed reference viewed: 59 (11 ULg)
Full Text
Peer Reviewed
See detailEffect of far-infrared radiation assisted drying on microstructure of banana slices: An illustrative use of X-ray microtomography in microstructural evaluation of a food product
Léonard, Angélique ULg; Blacher, Silvia ULg; Nimmol, Chatchai et al

in Journal of Food Engineering (2008), 85(1), 154-162

X-ray microtomography coupled with image analysis represents a non-destructive technique, which allows scanning an entire sample to obtain such information as total pore volume and pore size distribution ... [more ▼]

X-ray microtomography coupled with image analysis represents a non-destructive technique, which allows scanning an entire sample to obtain such information as total pore volume and pore size distribution without the need of serial cuts as in the case of scanning electron microscopy (SEM). The technique has been applied successfully to obtain reliable microstructural information of many products undergoing different physical and chemical processes. However, the technique has still found limited use in food processing. To illustrate the use of X-ray microtomography the technique was applied to investigate the effect of far-infrared radiation (FIR) assisted drying on microstructure of a food product viz. banana. Two representative drying techniques, i.e., low-pressure superheated steam drying (LPSSD) and vacuum drying (VACUUM) were tested. Banana slices were dried by LPSSD-FIR at two different temperatures (80 and 90 degrees C) at a fixed pressure of 7 kPa. The total pore volume and pore size distribution of dried banana slices were then determined using X-ray microtomography. The results were also compared with those of products dried by LPSSD without FIR. Far-infrared radiation was found to modify the structure of the dried bananas by increasing their final porosity. The same effect of FIR was also observed in the case of vacuum drying with FIR (VACUUM-FIR). An increase of the drying temperature was also found to globally lead to an increase in the final porosity of the products. (C) 2007 Elsevier Ltd. All rights reserved. [less ▲]

Detailed reference viewed: 189 (7 ULg)
Full Text
Peer Reviewed
See detailEffect Of Feed N-15 Incorporation Into Solid-Associated Bacteria On The In Situ Nitrogen Degradability Of N-15 Labelled Italian Ryegrass
Kamoun, Mohammed; Lopez, Secundino; Beckers, Yves ULg et al

in Animal Feed Science & Technology (2007), 135(3-4), 353-361

The objective of this study was to examine the effect of microbial contamination of the incubation residue on the in situ nitrogen degradability of Italian ryegrass. Microbial nitrogen in the bag residues ... [more ▼]

The objective of this study was to examine the effect of microbial contamination of the incubation residue on the in situ nitrogen degradability of Italian ryegrass. Microbial nitrogen in the bag residues was estimated by the feed 15N dilution procedure, and the incorporation of feed 15N into the adherent bacteria was assessed after isolating a bacterial pellet and determining its 15N enrichment. Isotopically labelled Italian ryegrass (fertilized with 15NH4 15NO3) was harvested either in spring (early cut) or in summer (late cut). Forages were incubated in the rumen of two steers for 6, 24 and48 h. The proportion of microbial N per unit of total N in the bag residue increased with incubation time, ranging from 184 to 853 mg microbial N/g totalN at 6 and 48 h, respectively. 15N enrichment in the bacterial pellet was highest after 6 h of incubation (3.6 mg 15N/g N) and then declined steadily (0.8 mg 15N/gN in 48-h residues). Microbial 15N represented up to 0.422 g/g total 15N in the bag residue, but the incorporation of feed 15N into bacterial N did not account for more than 57 mg/g 15N incubated, this incorporation rate decreasing progressively with incubation time. Correction of apparent N disappearance for microbial N resulted in higher values of N degradability, especially for the late cut grass. A further correction considering the amount of microbial 15N had little effect on the estimation of corrected N degradability values. Therefore, some of the feed 15N is incorporated into bacterial N, but this fraction has a minor effect on the estimation of total microbial N in the bag residue by the feed 15N dilution approach, and hence on the estimation of corrected degradability values. [less ▲]

Detailed reference viewed: 36 (4 ULg)
Peer Reviewed
See detailEffect of feed-, nitrogen-, fibres- and water-intakes on emissions of NH3, N2O, CH4, CO2 and water vapour of grouped gestating sows kept on straw-based deep litter
Philippe, François-Xavier ULg; Canart, Bernard; Laitat, Martine ULg et al

in 13th RAMIRAN International Conference, Potential for simple technology solutions in organic management (2008)

Detailed reference viewed: 43 (10 ULg)
Full Text
See detailEffect of feeding lambs with fat rapessed meal on the quality of their depot fat.
Wathelet, Jean-Paul ULg; Mabon, N.; Marlier, M.

in GCIRC Bulletin (1999)

Detailed reference viewed: 6 (0 ULg)
Full Text
Peer Reviewed
See detailEffect of feeding regimes on growth and survival of Clarias gariepinus larvae: replacement of Artemia by a commercial feed
Vandecan, M.; Diallo, A.; Mélard, Charles ULg

in Aquaculture Research (2011), 42(5), 733-736

Detailed reference viewed: 87 (13 ULg)
Full Text
Peer Reviewed
See detailEffect of FEM choices in the modelling of incremental forming of aluminium sheets
He, S.; Van Bael, A.; Van Houtte, P. et al

in Banabic, D. (Ed.) Proceedings of the 8th ESAFORM Conference on Material Forming (2005)

This paper investigates the process of single point incremental forming of an aluminium cone with a 50-degree wall angle. Finite element (FE) models are established to simulate the process. Different FE ... [more ▼]

This paper investigates the process of single point incremental forming of an aluminium cone with a 50-degree wall angle. Finite element (FE) models are established to simulate the process. Different FE packages have been used. Various aspects associated with the numerical choices as well as the material and process parameters have been studied. The final geometry and the reaction forces are presented as the results of the simulations. Comparison between the simulation results and the experimental data is also made. [less ▲]

Detailed reference viewed: 114 (5 ULg)
Full Text
Peer Reviewed
See detailEffect of Fengycin, a Lipopeptide Produced by Bacillus Subtilis, on Model Biomembranes
Deleu, Magali ULg; Paquot, Michel ULg; Nylander, T.

in Biophysical Journal (2008), 94(7), 2667-2679

Detailed reference viewed: 15 (4 ULg)
Peer Reviewed
See detailEffect of fertilisation with selenium on plasma selenium in Belgian Blue suckling cows and heifers: first results
Dufrasne, Isabelle ULg; Cabaraux, Jean-François ULg; Coenen, M. et al

in Land use systems in grassland dominated regions, 20th General Meeting of the European Grassland Federation (2004)

Detailed reference viewed: 5 (3 ULg)
Peer Reviewed
See detailEffect of fertilisation with selenium on plasma selenium in Belgian Blue suckling cows and heifers: first results
Dufrasne, Isabelle ULg; Cabaraux, Jean-François ULg; Coenen, M. et al

in Land use systems in grassland dominated regions, Book of abstracts of 20th General Meeting of the European Grassland Federation (2004)

Detailed reference viewed: 3 (0 ULg)
Full Text
Peer Reviewed
See detailThe effect of fiber morphology on the tensile strength of natural fibers
Alves Fidelis, Maria Ernestina; Vitorino Castro Pereira, Thatiana; Da Fonseca Martins Gomes, Otavio ULg et al

in Journal of Materials Research and Technology (2013), 2(2), 149-157

In the present work the morphology of natural fibers was correlated with their mechanical properties via image analysis. Jute, sisal, curaua, coir and piassava fibers were tested under direct tension in a ... [more ▼]

In the present work the morphology of natural fibers was correlated with their mechanical properties via image analysis. Jute, sisal, curaua, coir and piassava fibers were tested under direct tension in a universal testing machine and the cross-sectional areas of the fibers were calculated using images obtained in a scanning electron microscopy. For the jute fiber the tests were performed for several gage lengths in order to investigate its influence on the tensile strength and to compute the machine compliance. For sisal, jute and curaua fibers the amount of fiber-cells, the size of the cell walls and the real area of the fibers were measured and their correlation with the tensile strength addressed. The curaua fiber presented the highest mechanical performance with tensile strength and Young's modulus of 543 MPa and 63.7 GPa, respectively. Weibull statistical analysis was used to quantify the variability of fiber strength. The sisal fibers presented the highest Weibull modulus (3.70), whereas the curaua presented the lowest one (m = 2.2), which means that the sisal had the lowest variability and curaua the highest. [less ▲]

Detailed reference viewed: 20 (1 ULg)
Full Text
Peer Reviewed
See detailEffect of filler content and size on transport properties of water vapour in PLA/calcium sulfate composites
Gorrasi, Giuliana; Vittoria, Vittoria; Murariu, Marius et al

in Biomacromolecules (2008), 9

Starting from calcium sulfate (gypsum) as fermentation byproduct of lactic acid production process, high performance composites have been produced by melt-blending polylactide (PLA) and -anhydrite II (AII ... [more ▼]

Starting from calcium sulfate (gypsum) as fermentation byproduct of lactic acid production process, high performance composites have been produced by melt-blending polylactide (PLA) and -anhydrite II (AII) filler, i.e., calcium sulfate hemihydrate previously dried at 500 °C. Characterized by attractive properties due to good filler dispersion throughout the polyester matrix and favorable interactions between components, these composites are interesting for potential use as biodegradable rigid packaging. The effect of filler content and mean particle diameter on the barrier properties such as sorption and diffusion to water vapor has been examined and compared to unfilled PLA. Even without additional treatments, the presence of the filler introduced constraints on molecular mobility in the permeable phase of amorphous PLA and the amount of solvent absorbed appears lower in the highly filled composites. Surprisingly, for PLA-30% AII compositions, by addition of filler characterized by high mean particle diameter (e.g., 43 μm) the thermodynamic diffusion parameter, D0, decreased up to 2 orders of magnitude. The dimension of filler particles and their percentage in the continuous polymeric phase seem to be the most important parameters that determine the barrier properties of the PLA-AII composites to water vapor. [less ▲]

Detailed reference viewed: 9 (0 ULg)
Full Text
See detailEffect of finger tapping frequency on abnormal subthalamic nucleus oscillations in Parkinson’s disease
Stamatakis, Julien; Noirhomme, Quentin ULg; Orban, Jonhatan et al

Poster (2012, October)

Detailed reference viewed: 36 (8 ULg)
Peer Reviewed
See detailEffect of fish oil supplementation in a model of a feline asthma
Kirschvink, N.; Leemans, Jérôme ULg; Delvaux, F. et al

in Acta Physiologica (2008), 192(662 Suppl), 10

Detailed reference viewed: 39 (4 ULg)
Full Text
See detailEffect of food intake levels on leptin and IGF-I plasma concentrations in sheep
Archa, Bouchaib; Bister, Jean-Loup; Colinet, Frédéric ULg et al

in Acta Physiologica (2006), 187(Suppl 651), 4

The effect of high (H) or low (L) levels of food intake, during the preceding 51 weeks, on leptin and Insulin-like growth factor-I (IGF-I) plasma concentrations in sheep were investigated in groups of 20 ... [more ▼]

The effect of high (H) or low (L) levels of food intake, during the preceding 51 weeks, on leptin and Insulin-like growth factor-I (IGF-I) plasma concentrations in sheep were investigated in groups of 20 adult Timahdite (non-lactating, non-pregnant) ewes. Ewes of the two treatments had similar liveweight at the start of study but there was a twofold difference in energy intake. All animals were maintained indoors under natural daylength conditions (33°53'N, 5°32'W). Blood samples were collected monthly and the statistical analyses were performed on leptin and IGF-I levels. The mean leptin plasma concentrations were higher in H ewes than L sheep (3.98±0.97 ng/ml vs 3.34±1.17 ng/ml, P<0.05). For IGF-I, from week 1 to 26, the mean plasma concentrations were higher in H ewes than L sheep (76±28 ng/ml vs 58±21 ng/ml, P<0.01). However, from week 31 to 51, the mean plasma concentrations were similar in both groups (57±24 ng/ml vs 59±25 ng/ml, P>0.05). It was concluded that the food intake levels affect significantly leptin and IGF-I plasma concentrations and consequently may be the link between food intake, body condition and reproductive performances in sheep. [less ▲]

Detailed reference viewed: 60 (2 ULg)
Full Text
Peer Reviewed
See detailThe effect of food on growth and metamorphosis of paedomorphs in Triturus alpestris apuanus
Denoël, Mathieu ULg; Poncin, Pascal ULg

in Archiv für Hydrobiologie (2001), 152(4), 661-670

The effect of food level on growth and metamorphosis of paedomorphs was examined in an experimental replicated design in Triturus alpestris apuanus. Paedomorphosis concerns the retention of larval ... [more ▼]

The effect of food level on growth and metamorphosis of paedomorphs was examined in an experimental replicated design in Triturus alpestris apuanus. Paedomorphosis concerns the retention of larval characteristics in adult individuals. Newts that forgo metamorphosis and then retain gill and gill slits in the adult stage maintain an aquatic life but keep potential for undergoing metamorphosis. Paedomorphs metamorphosed later in treatments with food as a non-limiting factor than in stressful treatments where food was limited. Timing of metamorphosis did not differ between males and females. Food level greatly affected growth rates. These results confirm and extend optimality models that predict paedomorphosis under advantageous aquatic conditions (paedomorph advantage hypothesis) and metamorphosis in stressful aquatic habitats. [less ▲]

Detailed reference viewed: 187 (13 ULg)