Publications ORBi OA
Bookmark and Share    
Full Text
See detailIdentification of wire rope isolators using the restoring force surface method
Kerschen, Gaëtan ULg; Lenaerts, Vincent; Golinval, Jean-Claude ULg

in International Conference on Structural Systems Identification, Kassel, 2001 (2001)

The restoring force surface method offers an efficient and reliable identification of non-linear single-degree-of-freedom systems. The method may be extended to multidegree-of-freedom systems but by ... [more ▼]

The restoring force surface method offers an efficient and reliable identification of non-linear single-degree-of-freedom systems. The method may be extended to multidegree-of-freedom systems but by loosing the key advantage of the method which lies in the two-dimensional representation for single-degree-of-freedom systems. An experimental application of the restoring force surface method is considered in the present paper. The structure investigated consists of wire rope isolators mounted between a load mass and a base mass. These helical isolators were found to be characterised by a non-linear behaviour. The results obtained are discussed in details and the advantages and drawbacks of the method are underlined. [less ▲]

Detailed reference viewed: 49 (0 ULg)
Full Text
See detailRecent biogeographic and ecological studies on otter (Lutra lutra) and European mink (Mustela lutreola) in France
de Bellefroid, Marie des Neiges; Libois, Roland ULg; Rosoux, René

in Säugetierkundliche informationen (2001), 25

Otter and European mink are two threatened species in France. The mink is even considered to be on the verge of extinction. Studies have been carried out for more than ten years to attempt to understand ... [more ▼]

Otter and European mink are two threatened species in France. The mink is even considered to be on the verge of extinction. Studies have been carried out for more than ten years to attempt to understand the changes in their distribution and the ecological needs of these two semi-aquatic mustelids. The results of the research programmes completed or still under way, are presented. The French Ministry of Environment has set up two specific restoration plans, with the contribution of Conversation societies for wild fauna and scientific institutions. [less ▲]

Detailed reference viewed: 37 (4 ULg)
Full Text
Peer Reviewed
See detailTetraethyl(Pyrrolidine-2,2-diyl)Bisphosphonate
Olive, Gilles ULg; Jacques, Alain

in Molecules (2001), 6

Detailed reference viewed: 16 (2 ULg)
Full Text
See detailLa saisie et le traitement des données pour la mise à jour de cartes de peuplements forestiers
Lejeune, Philippe ULg

Learning material (2001)

Introduction La mise à jour des cartes des peuplements forestiers est une opération importante si l'on veut mettre à la disposition du gestionnaire forestier des documents cartographiques cohérents et ... [more ▼]

Introduction La mise à jour des cartes des peuplements forestiers est une opération importante si l'on veut mettre à la disposition du gestionnaire forestier des documents cartographiques cohérents et fiables. Malgré l'émergence de techniques modernes de cartographie informatisée (Système d'Information Géographique ou SIG), la collecte des données brutes sur le terrain reste une opération essentiellement manuelle dont les modalités de réalisation ne font, à l'heure actuelle, l'objet d'aucune spécification au plan de la méthode ou des critères de précision. L'objectif de la présente note technique est de proposer une méthode standardisée de saisie et de traitement des données pour la mise à jour de documents cartographiques à vocation forestière. Cette note se présente sous la forme d'un guide méthodologique visant à expliquer et illustrer de manière simple les principes théoriques liés à la cartographie, ainsi que la démarche de collecte des données sur le terrain et leur traitement informatisé. Après un bref rappel des principes théoriques de la localisation et de la délimitation d'objets en vue de leur représentation cartographique, nous présentons successivement la démarche de saisie des données sur le terrain et le traitement de ces données préalable à leur report dans un système de cartographie informatisée. [less ▲]

Detailed reference viewed: 21 (3 ULg)
Full Text
See detailImpact of biotechnology on animal breeding and genetic progress
Gengler, Nicolas ULg; Druet, Tom ULg

in Renaville, Robert; Burny, Arsène (Eds.) Biotechnology in Animal Husbandry (2001)

Animal breeding is a field related to a whole range of biotechnologies. The impact of a biotechnology can be measured by the influence it has on genetic progress. According to the type of biotechnology ... [more ▼]

Animal breeding is a field related to a whole range of biotechnologies. The impact of a biotechnology can be measured by the influence it has on genetic progress. According to the type of biotechnology considered, different component of genetic progress may be affected: accuracy of prediction, generation interval, intensity of selection and genetic variance. The first type of biotechnologies affects the efficiency of male and female reproduction: artificial insemination, multiple ovulation, in-vitro-fertilization, ova pick-up, embryo-transfer, twining, sexing of semen and embryos cloning and selfing. The impact of these technologies is mainly in the enhanced distribution of superior germplasm and the selection intensity, but also in the accuracy obtained when testing animals. In the past, artificial insemination has been a very successful biotechnology, enhancing greatly the genetic progress. A secondary, negative, impact is that these biotechnologies affect indirectly genetic diversity and therefore reduce genetic variance. A second group of biotechnologies can improve determination of the genetic merit of animals. These are all the techniques relate to quantitative or economical trait loci (QTL/ETL), their detection and use. Their main feature is the early availability in life, therefore allowing an earlier and more accurate selection. Two direction of research exists: detection of markers for the unknown QTL and direct use of a potential candidate genes as QTL/ETL. QTL/ETL will have a major impact on animal breeding especially if their use in future breeding programs can be optimized. A last type of biotechnologies with a large potential to affect animal breeding in the future are those with the ability to transform artificially DNA. The impact of these technologies is however still no very clear especially as gene expression and other issues remain unsolved. Biotechnology had, has and will have a major impact on animal breeding and genetic progress. To a certain extend animal breeding is a very promising field to use biotechnology as the past has already proven. [less ▲]

Detailed reference viewed: 77 (2 ULg)
Full Text
Peer Reviewed
See detailLa divinyl éther synthase de plantes
Hoyaux, P.; Fauconnier, Marie-Laure ULg; Delcarte, J. et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2001), 5(2), 79-84

Divinyl ether synthase, an enzyme of the lipoxygenase pathway transforms, in potato tubers, 9-hydroperoxides of fatty acids into colneleic and colnelenic acid, two divinyl ethers of fatty acids. The ... [more ▼]

Divinyl ether synthase, an enzyme of the lipoxygenase pathway transforms, in potato tubers, 9-hydroperoxides of fatty acids into colneleic and colnelenic acid, two divinyl ethers of fatty acids. The enzyme has been described in a limited number of quite different plants. The enzyme has also been detected in tomato roots, garlic bulbs, tobacco plants and in marine algae. The enzyme is bound to membranes and is located in the microsomal fraction. The molecular weight of the enzyme exceeds 100,000 Da, its optimal pH is around 9 and its high specificity for 9-hydroperoxides as substrate is described. The reactional mechanism has been elucidated using radio-labelled molecules. Colneleic and colnelenic acid can be degraded enzymatically or not into aldehydes and oxo-acids. Those last compounds are also formed by the action of hydroperoxide lyase on 9-hydroperoxides of fatty acids. As other enzymes of the lipoxygenase pathway, reaction products of divinyl ether synthase are involved in pathogenic resistance. Colneleic and colnelenic acid content in potato plants has been corelated with resistance to Phytophthora infestans. [less ▲]

Detailed reference viewed: 9 (4 ULg)
Full Text
Peer Reviewed
See detailOff Shelf Fluxes of Labile Materials by an Upwelling Filament in the NW Iberian Upwelling System
Alvarez-Salgado, Xosé Antón; Doval, M. D.; Borges, Alberto ULg et al

in Progress in Oceanography (2001), 50(2-4), 321-337

Daily changes in the concentrations of carbon and nitrogen species were monitored during the course of a Lagrangian drifter experiment in a recurrent upwelling filament south of Cape Finisterre (NW ... [more ▼]

Daily changes in the concentrations of carbon and nitrogen species were monitored during the course of a Lagrangian drifter experiment in a recurrent upwelling filament south of Cape Finisterre (NW Iberian Upwelling System). A drifting buoy released at the southern edge of the upwelling centre generated by the Cape moved 60km southwestwards from 3 to 7 August 1998. Organic matter in the 50m deep study water mass (average 77±2 μM C) consisted of: 57μM C of dissolved organic matter (DOM) with a C/N molar ratio of 19±2; 6μM C of DOM with a C/N ratio of 9±2, and 14μM C of 50% DOM and 50% suspended organic matter (POMsusp) with a C/N ratio of 6.0±0.4. Net conversion of consumed inorganic salts into accumulated TOM=POMsusp+DOM was 40% for nitrogen and 30% for carbon. Since the parcel of water crossed the shelf-edge, these conversion efficiencies are equivalent to net horizontal export-ratio of 0.4 and 0.3 respectively. A second drifter was deployed in the offshore-end of the filament, and was displaced 20km west between 14 and 17 August 1998. Nitrate was exhausted in the surface water and no significant changes were observed in the variables measured during the course of the second experiment. Low C/N ratios (6.5±0.4) and rapid POMsusp/DOM inter-conversion in the 20 μM C excess observed in the study volume points to the persistence of the labile materials formed on the shelf during transport to the ocean. Our data demonstrate a) the key role of upwelling filaments in off-shelf export of organic materials and b) the major contribution of DOM to this horizontal export, a previously unaccounted amount. [less ▲]

Detailed reference viewed: 29 (7 ULg)
Full Text
Peer Reviewed
See detailOral vitamin C attenuates acute ischaemia-reperfusion injury in skeletal muscle.
Kearns, S. R.; Moneley, D.; Murray, P. et al

in Journal of Bone & Joint Surgery, British Volume (2001), 83(8), 1202-6

Ischaemia-reperfusion injury (IRI) is caused by endothelial and subendothelial damage by neutrophil-derived oxidants. Vitamin C is an antioxidant which attenuates endothelial injury after IRI. Our aim was ... [more ▼]

Ischaemia-reperfusion injury (IRI) is caused by endothelial and subendothelial damage by neutrophil-derived oxidants. Vitamin C is an antioxidant which attenuates endothelial injury after IRI. Our aim was to evaluate the effect of oral vitamin C in the prevention of IRI in skeletal muscle. We used a model of cross-clamping (3 hours) and reperfusion (1 hour) of the cremaster muscle in rats. Muscle function was assessed electrophysiologically by electrical field stimulation. Infiltration by neutrophils was determined by the activity of tissue myeloperoxidase (MPO) and tissue oedema by the wet-to-dry ratio. Neutrophil respiratory burst activity was measured in control animals and groups pretreated with vitamin C. IRI significantly decreased muscle function and increased muscle neutrophil MPO activity and muscle oedema. Pretreatment with vitamin C preserved muscle function and reduced tissue oedema and neutrophil infiltration. Neutrophil respiratory burst activity was reduced in the group treated with vitamin C compared with the control group. We conclude that pretreatment with oral vitamin C protects against acute muscle IRI, possibly by attenuating neutrophil respiratory burst activity. [less ▲]

Detailed reference viewed: 9 (2 ULg)
Full Text
Peer Reviewed
See detailLa métallurgie ancienne en "Terre de Durbuy" : Utilisation des macroscories en dynamique fluviale
Houbrechts, Geoffrey ULg; Petit, François ULg

in Bulletin de la Société Géographique de Liège (2001), 40

Avant d’utiliser les scories métallurgiques comme traceur et indicateur de la compétence de l’Aisne à différents endroits de son cours, nous avons relevé les différents atouts qui ont favorisé le ... [more ▼]

Avant d’utiliser les scories métallurgiques comme traceur et indicateur de la compétence de l’Aisne à différents endroits de son cours, nous avons relevé les différents atouts qui ont favorisé le développement de la sidérurgie dans la « Terre de Durbuy » et nous avons étudié l’évolution des techniques sidérurgiques afin de mieux comprendre la genèse des scories. Dans cet article, nous étudions plus particulièrement l’évolution longitudinale de la taille des scories dans l’Aisne, entre Blier et Bomal où elle se jette dans l’Ourthe. Vu la trop grande proximité des sites de rejets, nous n’avons pu proposer qu’une vitesse minimum d’avancée de la charge de fond ; les scories prélevées nous ont cependant renseignés sur les variations de puissances spécifiques dans les différents tronçons de la rivière. [less ▲]

Detailed reference viewed: 65 (18 ULg)
Full Text
Peer Reviewed
See detailThe SH2 domain containing 5-phosphatase SHIP2 is expressed in the germinal layers of embryo and adult mouse brain : increased expression in N_CAM deficient mice.
Muraille, Eric; Dassesse, Donald; Vanderwinden, Jean-Marie et al

in Neuroscience (2001), 105

Detailed reference viewed: 1 (0 ULg)
Full Text
Peer Reviewed
See detailNeuregulin signaling regulates neural precursor growth and the generation of oligodendrocytes in vitro
Calaora, Viviane; Rogister, Bernard ULg; Bismuth, Karen et al

in Journal of Neuroscience (2001), 21

Detailed reference viewed: 6 (1 ULg)
Full Text
Peer Reviewed
See detailMultiphase Transient Flow and Pressures in Rock Joints due to High Velocity Jet Impact: an Experimental and Numerical Approach
Bollaert, Erik; Pirotton, Michel ULg; Schleiss, Anton

in International Symposium on Environmental Hydraulics (2001)

Detailed reference viewed: 7 (0 ULg)
Full Text
Peer Reviewed
See detailLiver transplantation for hepatitis B virus infection: improving long-term outcomes
Detry, Olivier ULg; Delwaide, Jean ULg

in Medscape Transplantation (2001)

Detailed reference viewed: 11 (6 ULg)
Full Text
Peer Reviewed
See detailProtein adsorption on preadsorbed polyampholytic monolayers
Mahltig, Boris; Werner, Carsten; Müller, Martin et al

in Journal of Biomaterials Science. Polymer Edition (2001), 12(9), 995-1010

The adsorption behaviour of five different globular proteins on pure silicon substrates and on preadsorbed polyampholytic monolayers has been investigated as a function of protein concentration. The ... [more ▼]

The adsorption behaviour of five different globular proteins on pure silicon substrates and on preadsorbed polyampholytic monolayers has been investigated as a function of protein concentration. The prelayers were prepared by adsorption of the ampholytic diblock copolymer poly(methacrylic acid)-block-poly ((dimethylamino)ethyl methacrylate) (PMAA-b-PDMAEMA). This polyampholyte adsorbs in densely packed micelles directly from aqueous solution. Ellipsometry was used to determine the amount of adsorbed polyampholyte and protein. While ATR-IR spectroscopy gives information about the adsorption and desorption behaviour of the preadsorbed polyampholytic layer, the lateral structures of the dried films were investigated by scanning force microscopy (SFM). The amount of protein adsorbed was found to be strongly influenced by the preadsorbed polyampholyte compared to the adsorption on the pure silicon substrates. No displacement of the polyampholyte by the proteins was detected. In most cases the protein adsorption was reduced by the preadsorbed polyampholytic layer. The observed trends are explained by the change in electrostatic and hydrophilic characteristics of the substrates. Furthermore, the entropy of adsorption has to be taken into account. [less ▲]

Detailed reference viewed: 22 (2 ULg)
Full Text
See detailQuoi de neuf en littératie ? : Regard sur trente ans d'évaluation de la lecture
Lafontaine, Dominique ULg

in Cahiers du Service de Pédagogie Expérimentale (SPE) (2001), (7-8), 71-95

Detailed reference viewed: 69 (3 ULg)
Full Text
See detailGérer l'hétérogénéité des élèves : Méthodes de regroupement des élèves dans l'enseignement obligatoire
Monseur, Christian ULg; Demeuse, Marc ULg

in Cahiers du Service de Pédagogie Expérimentale (SPE) (2001), (7-8), 25-52

Detailed reference viewed: 61 (1 ULg)
Full Text
Peer Reviewed
See detailKey criteria for the design of polymeric stabilizers for aqueous titanium dioxide dispersions of high solid content
Creutz, Serge; Jérôme, Robert ULg

in e-Polymers (2001), (14), 1-9

Amphiphilic copolymers consisting of an animated hydrophobic block and a hydrophilic poly(sodium methacrylate) one have been synthesized with different structures and tested as stabilizers for aqueous ... [more ▼]

Amphiphilic copolymers consisting of an animated hydrophobic block and a hydrophilic poly(sodium methacrylate) one have been synthesized with different structures and tested as stabilizers for aqueous dispersions of alumina coated titanium dioxide (80 wt.-% solid). The dispersion stability is ruled by the strength of the anchoring of the aminated block onto the pigment and by the dynamics of the micelles formed by the copolymer. Any decrease in the anchoring strength, for example as a result of higher steric hindrance for the adsorbing block or of random rather than blocky distribution of the aminated co-units, is detrimental to the dispersion stability and makes this stability more dependent on the copolymer composition. Indeed, the position and dynamics of the unimers micelles equilibrium then control the adsorption of the copolymer on the pigment during the grinding process. [less ▲]

Detailed reference viewed: 37 (2 ULg)
Full Text
Peer Reviewed
See detailAutoimmune Pancreatitis Mimicking Cancer of the Head of Pancreas: Report of Two Cases
Servais, Anne-Marie ULg; Pestieau, Sophie R; Detry, Olivier ULg et al

in Acta Gastro-Enterologica Belgica (2001), 64(2, Apr-Jun), 227-30

Autoimmune pancreatitis has been characterised in 1995, but only a few cases have been published since then, most of them from Japan. This report describes the cases of two Belgian male patients who ... [more ▼]

Autoimmune pancreatitis has been characterised in 1995, but only a few cases have been published since then, most of them from Japan. This report describes the cases of two Belgian male patients who presented with isolated obstructive jaundice. Radiological imaging studies were highly suggestive of carcinoma of the head of pancreas and both patients underwent uneventful cephalic pancreaticoduodenectomy with portal vein resection. Pathological analysis of the removed tissues suggested an autoimmune process in both cases. Both patients had hyper-gammaglobulinemia and antinuclear antibodies, but failed to show evidence of any other autoimmune disease or cause of chronic pancreatitis. In both cases final diagnosis was autoimmune pancreatitis. Preoperative clinical suspicion of this diagnosis is mandatory and may avoid unnecessary surgery in future cases. [less ▲]

Detailed reference viewed: 92 (6 ULg)
Full Text
Peer Reviewed
See detailAnthesis effects on Posidonia oceanica (L.) Delile phenology in the Bay of Calvi (Corsica, Mediterranean Sea)
Gobert, Sylvie ULg; Defawe, Olivier; Lepoint, Gilles ULg et al

in Hydrobiologia (2001), 455

In Posidonia oceanica (L.) Delile, anthesis induces a decrease in the number of juvenile leaves resulting in a significant reduction in the number of leaves on the flowering shoots. All the leaves of the ... [more ▼]

In Posidonia oceanica (L.) Delile, anthesis induces a decrease in the number of juvenile leaves resulting in a significant reduction in the number of leaves on the flowering shoots. All the leaves of the flowering shoots are narrower than the leaves of nonflowering shoots. A modification of the leaf growth also appears in flowering shoots: the oldest leaves are longer and the leaves induced during or after anthesis are shorter. At 10 m depth, in the Bay of Calvi, anthesis lasts roughly 3 months and the flowering is induced 7 months before anthesis. [less ▲]

Detailed reference viewed: 62 (12 ULg)