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See detailStructural features conferring dual Geranyl/Farnesyl diphosphate synthase activity to an aphid prenyltransferase
Vandermoten, Sophie ULg; Santini, Sébastien; Haubruge, Eric ULg et al

in Insect Biochemistry and Molecular Biology (2009), 39(10), 707-716

In addition to providing lipid chains for protein prenylation, short-chain isoprenyl diphosphate synthases (scIPPSs) play a pivotal role in the biosynthesis of numerous mevalonate pathway end-products ... [more ▼]

In addition to providing lipid chains for protein prenylation, short-chain isoprenyl diphosphate synthases (scIPPSs) play a pivotal role in the biosynthesis of numerous mevalonate pathway end-products, including insect juvenile hormone and terpenoid pheromones. For this reason, they are being considered as targets for pesticide development. Recently, we characterized an aphid scIPPS displaying dual geranyl diphosphate (GPP; C10)/farnesyl diphosphate (FPP; C15) synthase activity in vitro. To identify the mechanism(s) responsible for this dual activity, we assessed the product selectivity of aphid scIPPSs bearing mutations at Gln107 and/or Leu110, the fourth and first residue upstream from the “first aspartate-rich motif” (FARM), respectively. All but one resulted in significant changes in product chain-length selectivity, effectively increasing the production of either GPP (Q107E, L110W) or FPP (Q107F, Q107F–L110A); the other mutation (L110A) abolished activity. Although some of these effects could be attributed to changes in steric hindrance within the catalytic cavity, molecular dynamics simulations identified other contributing factors, including residue-ligand Van der Waals interactions and the formation of hydrogen bonds or salt bridges between Gln107 and other residues across the catalytic cavity, which constitutes a novel product chain-length determination mechanism for scIPPSs. Thus the aphid enzyme apparently evolved to maintain the capacity to produce both GPP and FPP through a balance between these mechanisms. [less ▲]

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See detailDecentralized tap changer blocking and load shedding against voltage instability: prospective tests on the RTE system
Capitanescu, Florin ULg; Otomega, Bogdan; Lefebvre, Hervé et al

in International Journal of Electrical Power & Energy Systems (2009), 31(9), 570-576

This paper reports on prospective tests of a system protection scheme against long-term voltage instability relying on a set of distributed controllers, each monitoring a transmission voltage, blocking ... [more ▼]

This paper reports on prospective tests of a system protection scheme against long-term voltage instability relying on a set of distributed controllers, each monitoring a transmission voltage, blocking tap changers and shedding loads in a zone. The emergency actions adjust in magnitude and location to the disturbance. Each controller acts in closed-loop, which guarantees robustness. The method is illustrated on a real-life model of the Western region of the RTE system. The choice of the controller settings is discussed in some detail and examples of performance are given, combining the above remedial action with capacitor switching and secondary voltage control. [less ▲]

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See detailManagement strategies in urban green spaces: Models based on an introduced exotic pet turtle
Teillac-Deschamps, Pauline; Lorillière, Romain; Servais, Véronique ULg et al

in Biological Conservation (2009), 142(10), 2258-2269

A number of recent authors have emphasised the increasing disconnection from conservation issues among urban dwellers. In a global increase of urbanisation, this disconnect can have an impact on ... [more ▼]

A number of recent authors have emphasised the increasing disconnection from conservation issues among urban dwellers. In a global increase of urbanisation, this disconnect can have an impact on conservation practices. Here, we discuss how managers of public green spaces can contribute to global biodiversity preservation, through combined efforts to preserve local biodiversity and educate the public about conservation issues. We compared several management strategies, including those that mixed direct action on local biodiversity with public education and those that did not. Two kinds of one-way communication were considered as well as a two-way communication process, which take into account different perceptions and practices of nature. We based our model on the introduction of the red-eared slider turtle, Trachemys scripta elegans, into urban French freshwater ecosystems. We found that direct actions only had a limited, short term effect on the abundance of feral turtles in green spaces and had no effect on the level of public concern about environmental questions. We also showed that a mix of different communication strategies improved people’s awareness and altered behaviour with respect to introduced species issues. Finally, we showed the importance of a two-way communication that takes into account the diversity of personal perceptions and practices as regards nature in urban areas in order to achieve sustainable conservation measures and objectives [less ▲]

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See detailInfluence d’images évocatrices et distractrices sur une tâche de jugement en acoustique des salles
Defays, Aurore ULg; Safin, Stéphane ULg; Billon, Alexis ULg et al

in Proceedings IHM'09 (2009, October)

Dans le cadre de la conception d’un espace immersif multimodal visant à soutenir la tâche d’évaluation de la qualité acoustique de salles sur base de simulations numériques, nous nous intéressons aux ... [more ▼]

Dans le cadre de la conception d’un espace immersif multimodal visant à soutenir la tâche d’évaluation de la qualité acoustique de salles sur base de simulations numériques, nous nous intéressons aux liens entre l’image et le son. 54 sujets ont été confrontés à une tâche de jugement du degré de réverbération d’un extrait sonore dans une situation contrôle (sans image) puis dans une situation expérimentale avec, pour la moitié des sujets, une image visant à soutenir le jugement (cohérente avec le son) et, pour l’autre moitié, une image « distractrice ». Nos résultats montrent une influence positive des images évocatrices et pas d’effet des images distractrice. [less ▲]

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See detailMagnetic shielding properties of high- Tc superconducting hollow cylinders: model combining experimental data for axial and transverse magnetic field configurations
Fagnard, Jean-François ULg; Dirickx, Michel; Ausloos, Marcel ULg et al

in Superconductor Science and Technology (2009), 22(10), 10500210

Magnetic shielding efficiency was measured on high- Tc superconducting hollow cylinders subjected to either an axial or a transverse magnetic field in a large range of field sweep rates, dBapp/dt. The ... [more ▼]

Magnetic shielding efficiency was measured on high- Tc superconducting hollow cylinders subjected to either an axial or a transverse magnetic field in a large range of field sweep rates, dBapp/dt. The behaviour of the superconductor was modelled in order to reproduce the main features of the field penetration curves by using a minimum number of free parameters suitable for both magnetic field orientations. The field penetration measurements were carried out on Pb-doped Bi-2223 tubes at 77 K by applying linearly increasing magnetic fields with a constant sweep rate ranging between 10 uT s[?]1 and 10 mT s[?]1 for both directions of the applied magnetic field. The experimental curves of the internal field versus the applied field, Bin(Bapp), show that, at a given sweep rate, the magnetic field for which the penetration occurs, Blim, is lower for the transverse configuration than for the axial configuration. A power law dependence with large exponent, n', is found between Blim and dBapp/dt. The values of n' are nearly the same for both configurations. We show that the main features of the curves Bin(Bapp) can be reproduced using a simple 2D model, based on the method of Brandt, involving a E(J) power law with an n-exponent and a field-dependent critical current density, Jc(B), (following the Kim model: Jc = Jc0(1+B/B1)[?]1). In particular, a linear relationship between the measured n'-exponents and the n-exponent of the E(J) power law is suggested by taking into account the field dependence of the critical current density. Differences between the axial and the transverse shielding properties can be simply attributed to demagnetizing fields. [less ▲]

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See detailIschaemic mitral regurgitation: mechanisms and diagnosis.
Marwick, Th; Lancellotti, Patrizio ULg; Pierard, Luc ULg

in Heart (2009), 95(20), 1711-8

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See detailRECENT STUDIES CONDUCTED AT LIEGE UNIVERSITY IN THE FIELD OF COMPOSITE CONSTRUCTION
Demonceau, Jean-François ULg; Jaspart, Jean-Pierre ULg

Report (2009)

The present informal document summarises recent or ongoing studies conducted at Liège University in the field of steel-concrete composite constructions; they are summarised in a Table presented at the ... [more ▼]

The present informal document summarises recent or ongoing studies conducted at Liège University in the field of steel-concrete composite constructions; they are summarised in a Table presented at the following page. Only the main results are presented herein. For all the addressed topics, references to documents, reports and articles where details are available will be made; a copy of these documents can be obtained by contacting us. At the end of each paragraph, a section dedicated to some perspectives is given. § 9.2 summarises the main topics in which investigations could be conducted in the future; these perspectives are also reported in the Table here after. The activities related to the response of composite structures subjected to seismic or fire actions (mainly covered in Liège by Prof. Plumier and Prof. Franssen respectively) are not reported here as they are covered by other more “transversal” technical committees of ECCS (TC3 for the fire and TC13 for the seismic action). The “composite joints” topic is included here even if a technical committee relative to the behaviour of joints exists within ECCS (TC10); indeed, in the past, all the developments relative to composite joints were discussed and accepted within TC11 and not within TC10. Of course, it is up to the present TC11 members to decide whether this topic has or not to be considered within TC11. Finally, the robustness of composite structures and in particular, the robustness of the structures subjected to the exceptional event “loss of a column further” is also considered herein as this topic is not yet covered by any other technical committee. Again, it is up to the TC11 members to decide whether this topic has to be discussed within TC11. [less ▲]

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See detailA Practical Bytecode Interpreter for Programmable Routers on Network Processor
Martin, Sylvain ULg; Leduc, Guy ULg

in Computer Networks (2009), 53(15), 2740-2751

WASP is a programmable router platform that allows end-hosts to store ephemeral state in routers along the path of IP flows and to execute packet-attached bytecode that processes this data. We exploit ... [more ▼]

WASP is a programmable router platform that allows end-hosts to store ephemeral state in routers along the path of IP flows and to execute packet-attached bytecode that processes this data. We exploit lessons from past active network research and our knowledge of network processors to design a minimal interpreter that favours language restrictions over run-time checks. WASP provides safety with limited performance penalty through predictable execution time and bounded usage of memory and network resources. WASP is expressive enough to enable several applications including statistics collection and service discovery. It can also detect common trunk of two Internet paths and exchange local measurements about these paths. We propose a robust implementation on the IXP2400 network processor, and evaluate its performance through short benchmark programs against native functions hard-coded in the router. We achieve latencies below 7$\,\mu{s}$, i.e. less than the reference IPv4 forwarding latency, and throughputs approaching 800\,kpps per core, which competes with, and sometimes even outperforms, native programs. We further exploit our results to give hints on further improving resource usage and guidelines on management of ephemeral stores in high-speed networks. [less ▲]

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See detailPrevalence of Chronic Kidney Disease in an Elderly Population: Impact of the Choice of the Equation Used for Estimating GFR
Mariat, Christophe; Cavalier, Etienne ULg; Maillard, Nicolas et al

Poster (2009, October)

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See detailLa rétinopathie du prématuré
Battisti, Oreste ULg

Learning material (2009)

cours sur la rétinopathie du prématuré

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See detailL'analphabétisme en santé
Henrard, Gilles ULg

in Santé Conjuguée (2009)

L’analphabétisme dans le domaine de la santé semble être une réalité fréquente, sous-estimée et posant problème tant à un niveau individuel que collectif ; c’est un des visages de l’exclusion sociale qui ... [more ▼]

L’analphabétisme dans le domaine de la santé semble être une réalité fréquente, sous-estimée et posant problème tant à un niveau individuel que collectif ; c’est un des visages de l’exclusion sociale qui intervient dans les inégalités de santé. Interpellé par les difficultés qu’il pressentait chez certains de ses patients, Gilles Henrard, médecin généraliste, a approfondi cette question avec des apprenants de l'asbl Lire et Ecrire. C’est suite à ce travail que Lire et Ecrire a mené un projet autour de la santé du coeur avec d’autres apprenants, projet présenté à la suite de cet article. [less ▲]

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See detailSound Field Modeling in Architectural Acoustics using a Diffusion Equation Based Model
Fortin, Nicolas; Picaut, Judicaël; Billon, Alexis ULg et al

Conference (2009, October)

In this paper, an implementation of a model for room-acoustic predictions in COMSOL Multiphysics is presented. The model (called diffusion model) is based on the solving of diffusion equations instead of ... [more ▼]

In this paper, an implementation of a model for room-acoustic predictions in COMSOL Multiphysics is presented. The model (called diffusion model) is based on the solving of diffusion equations instead of classical wave equations and allows simulating the sound propagation in complex geometries at high frequency. Instead of using COMSOL Multiplysics to solve directly the problem, a specific tool has been developed. It is composed of a user-friendly interface (I-Simpa) which manipulates all the physical data of the problem (geometries, acoustic properties and elements…) and generates an interoperability script to execute COMSOL Multiplysics via the generation of .m file scripts. Then, numerical results are processed by I-Simpa for the acoustic post-treatment and results display, like sound levels, reverberation times… [less ▲]

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See detailDéambuler dans la ville. Une expérience visuelle critique et artistique
Hagelstein, Maud ULg

Article for general public (2009)

Du 3 juin au 6 septembre, l’exposition Heaven and Earth présentait les œuvres peu bavardes de Richard Long à la Tate Britain. Comme à Rome, à Sydney ou à Tokyo, l’artiste anglais fit venir des pierres ... [more ▼]

Du 3 juin au 6 septembre, l’exposition Heaven and Earth présentait les œuvres peu bavardes de Richard Long à la Tate Britain. Comme à Rome, à Sydney ou à Tokyo, l’artiste anglais fit venir des pierres, anguleuses et/ou polies, pour ses installations Land Art d’intérieur (le paradoxe est assumé). Quelques photographies envoûtantes montraient aussi les interventions minimalistes de Long dans le paysage : un sac à dos posé contre un tas de pierre, une croix au sol dans un champ de fleurs, une ligne dans le désert. Mais ces aspects de l’œuvre sont désormais classiques et le caractère inédit du projet de Richard Long est ailleurs : en tant qu’il exploite le potentiel artistique de la marche, l’artiste indique sa valeur conceptuelle et créative. De fait, chaque promenade semble avoir pour mission de poursuivre une idée – même s’il n’en reste à peu près rien à l’arrivée qu’une indication rapide, généralement quantitative, imprimée sur papier. Entre deux sorties, il inverse par exemple la distance parcourue et le timing : « Hours / Miles / A walk of 24 hours : 82 miles / A walk of 24 miles in 82 hours / England 1996 ». De ses marches, on voit peu de choses exposées, si ce n’est le concept, énoncé comme ici en quelques mots. L’artiste réalise des expériences, calcule des distances, récolte des sons. Combien de temps pourra-t-il marcher au sec entre deux averses ? « Dry Walk / 113 walking miles between one shower of rain and the next / Avon England 1989 ». D’autres fois, les parcours tracent des lignes sur de vastes territoires et sont comme des dessins grandeur nature. Le mouvement et l’arrêt constituent les éléments « picturaux » de ces gigantesques fresques virtuelles (que Long reproduit néanmoins sur des cartes). À l’échelle maximale, la marche suivra alors telle spirale, ou telle forme géométrique, décidée par avance. Et si l’hypothèse de Richard Long n’était pas si folle ? S’il suffisait de marcher pour faire de l’art ? [less ▲]

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See detailLe pilotage macro-budgétaire des finances locales
Husson, Jean-François ULg; Steckel, Marie-Christine

in Revue Européenne de l'Action Publique [=REAP] (2009), (1), 11

Ce bref article présente les justifications et modalités de mise en oeuvre du pilotage macro-budgétaire des finances locales, c.-à-d. de leur intégration dans le pilotage global du secteur des ... [more ▼]

Ce bref article présente les justifications et modalités de mise en oeuvre du pilotage macro-budgétaire des finances locales, c.-à-d. de leur intégration dans le pilotage global du secteur des administrations publiques tant en termes de solde de financement que de dette. [less ▲]

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See detailTraitement percutané d’une cardiomyopathie hypertrophique obstructive
Moonen, Marie ULg; Legrand, Victor ULg; Lancellotti, Patrizio ULg et al

in Revue Médicale de Liège (2009), 64(10), 481

Detailed reference viewed: 70 (4 ULg)