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See detailMultifunctional coatings
Van de Weerdt, Cécile ULg; Detrembleur, Christophe ULg; Jérôme, Robert ULg et al

Patent (2009)

New polyelectrolyte copolymer, composite material, multilayer film and substrate carrying such polyelectrolyte copolymer, composite and multilayer film wherein the polyelectrolyte copolymer comprises a) a ... [more ▼]

New polyelectrolyte copolymer, composite material, multilayer film and substrate carrying such polyelectrolyte copolymer, composite and multilayer film wherein the polyelectrolyte copolymer comprises a) a first type of identical or different units (A) each comprising one or more dihydroxyphenyl groups such that sidechains are present along the backbone of the polyelectrolyte copolymer which contain at least one dihydroxyphenyl group each; and (b1) a second type of identical or different units (B1) each comprising a cationic moiety, or (b2) a second type of identical or different units (B2) each comprising an anionic moiety. [less ▲]

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See detailGravitationally lensed quasars: light curves, observational constraints, modeling and the Hubble constant.
Chantry, Virginie ULg

Doctoral thesis (2009)

The central topic of this thesis is gravitational lensing, a phenomenon that occurs when light rays from a background source pass near a massive object located on the line of sight and are deflected. It ... [more ▼]

The central topic of this thesis is gravitational lensing, a phenomenon that occurs when light rays from a background source pass near a massive object located on the line of sight and are deflected. It is one of the most wonderful observational fact in favour of the General Theory of Relativity (Einstein, 1916). This phenomenon constitutes a powerful tool to probe different areas in astrophysics, including cosmology, which is our main interest. In particular we study gravitationally lensed quasars. Refsdal (1964) was the first to state that time delays between different lensed images of the same object, if this one is intrisically variable, can lead to the measurement of the Hubble constant H0, which is related the actual expansion rate of the Universe. Up to now, only a few lensed quasars have led to H0 and the precision on it has never reached the one obtained with other methods as the ones based on the Cosmic Distance Ladder. That is why some scientists from around the globe decided to unite their force to measure H0 from about thirty lensed quasars. To reach that goal, these objects are being monitored with some mid-sized ground-based telescopes located in both hemispheres. This thesis is realised in the framework of this collaboration called COSMOGRAIL for COSmological MOnitoring of GRAvItational Lenses. This work focuses on image processing and on several steps mandatory to obtain a measurement of H0 from lensed quasars: the acquisiton of the light curves from which it is possible to extract the time delays and the acquisition of the observational constraints necessary to model the gravitational potential responsible for the observed configura- tion. The central technique of this work is the image deconvolution with the MCS algorithm (Magain, Courbin & Sohy, 1998). The main principle of this algorithm is the non-violation of the sampling theorem in trying to obtain a better resolution in the deconvolved frame instead of an infinite one. The final resolution in the deconvolved frame is chosen by the user and as it is known, every image is decomposed in a contri- bution from the point sources and another one from all the extended structures such as arcs, rings and galaxies. To obtain good light curves from data coming from several telescopes, good reduction procedures are needed. That is why Vuissoz (2008) developed a semi-automated reduc- tion pipeline including deconvolution with the MCS algorithm. In the framework of the i ii Abstract present thesis, we adapt it to one of the telescopes used by the collaboration whose data were never used before, i.e. the Mercator telescope. We also bring some modifications to this pipeline, e.g. concerning the estimation of the error on the magnitudes of the light curves. We apply this revised version of the reduction pipeline to HE 0435-1223, a quadruply imaged quasar with already measured time delays (Kochanek et al., 2006). Another object, the quad WFI J2026-4536, is then investigated: we obtain light curves for each of the four lensed images. Thanks to the CASTLES project (Cfa-Arizona Space Telescope LEns Survey1), many lensed quasars have been observed with the camera 2 of NICMOS (Near Infrared Camera and Multi-Object Spectrometer ) on board the Hubble Space Telescope. With these high resolution images, we can obtain very accurate constraints on the geometry of the lensed systems. But most of the time no star is available in the field of view to obtain a good Point Spread Function (PSF). That is why we develop an iterative strategy combined with the MCS algorithm: we call it ISMCS. This technique allows to use the lensed images themselves to improve the PSFs step by step while simultaneously deconvolving the frame to obtain better estimations of the extended structures in the image. We first test this strategy on a quadruply imaged quasar, the Cloverleaf gravitational lens (H1413+117), and obtain relative positions precise to 1 milliarcsecond (mas). We then apply ISMCS to the quadruply imaged quasar WFI J2033-4723 in order to con- tribute to the estimate of the Hubble constant, as this object was monitored by our team. We then study a sample of seven lensed systems currently monitored by COSMOGRAIL and for which time delays have never been obtained. Here again, we obtain positional constraints with an accuracy of around 1 to 2 mas thanks to the application of ISMCS. We then model these systems with simple mass profiles for the main lens galaxy and obtain an estimation of the values of the time delays. Finally we apply ISMCS to a sample of eleven lensed quasars which already have measured time delays. When the delays have been remeasured by our team, in four cases until now, we also model the potential of the lens with simple mass profiles to estimate H0. 1http://www.cfa.harvard.edu/castles [less ▲]

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See detailRétroconversion automatique du Französisches Etymologisches Wörterbuch (FEW)
Renders, Pascale ULg

Poster (2009, December 09)

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See detailLa prédation
Sibony, Anne-Lise ULg

Conference (2009, December 09)

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See detailContrer les effets du manque de lumière : La luminothérapie
Blain, Pascal ULg

Conference given outside the academic context (2009)

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See detailCross-linked pH sensitive polymer micelles for drug delivery systems
Cajot, Sébastien ULg; Jérôme, Christine ULg

Poster (2009, December 08)

Over the last decade, polymer micelles attracted an increasing interest in drug pharmaceutical research because they could be used as efficient drug delivery systems. Micelles of amphiphilic block ... [more ▼]

Over the last decade, polymer micelles attracted an increasing interest in drug pharmaceutical research because they could be used as efficient drug delivery systems. Micelles of amphiphilic block copolymers are supramolecular core-shell type assemblies of tens of nanometers in diameter. In principle, the micelles core is usually constructed with biodegradable hydrophobic polymers such as aliphatic polyesters, e.g. poly(ɛ-caprolactone) (PCL), which serves as a reservoir for the incorporation of various lipophilic drugs. Water soluble poly(ethylene oxide) (PEO) is most frequently used to build the micelle corona because it is very efficient in preventing protein adsorption at surfaces and in stabilizing the micelles in the blood compartment, giving rise to particles invisible to the body defence system (so-called stealthy or long circulating particles). The tumour targeting of a cytotoxic agent refers to the passive accumulation of polymer nanocarriers to solid tumours (EPR effect) followed by active internalization in tumor cells. The internalization of the drug is required for cell death because most cytotoxic drugs act intracellularly. Accordingly, polymer micelles are usually modified by specific ligands. No-specific ligands can be used if their exposition is modulated by the pH decrease typical of tumour tissues. The release of the drug is ruled by diffusion and degradation of the biodegradable polymer used as reservoir. Even if micelles get a high stability in aqueous media thanks to their low critical micellar concentration, the dissociation of micelles is not always preserved when they are injected in the blood compartment. The cross-linking of the core of micelles by disulfide bridges will provide the stability of micelles after the administration and will release the drugs intracellularly by enzymatic breaking of disulfide bridges. This work consists in the development of new macromolecular architectures for the targeting of tumour cells. pH sensitive copolymers able to micellize so as non-specific ligand like biotin is exposed on their surface in response to pH decrease typical for tumour tissues will be synthesized by the incorporation of pH-sensitive linkers, e.g. imine benzoïc linkers. In addition, the core of these new micelles will be cross-linked by disulfide bridges to prevent dissociation around healthy cells and trigger the drug release inside tumour cells. [less ▲]

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See detailThe Emerging Role of Exercise Testing and Stress Echocardiography in Valvular Heart Disease
Picano, Eugenio; Pibarot, Philippe; Lancellotti, Patrizio ULg et al

in Journal of the American College of Cardiology (2009), 54(24), 2251-60

Exercise testing has an established role in the evaluation of patients with valvular heart disease and can aid clinical decision making. Because symptoms may develop slowly and indolently in chronic valve ... [more ▼]

Exercise testing has an established role in the evaluation of patients with valvular heart disease and can aid clinical decision making. Because symptoms may develop slowly and indolently in chronic valve diseases and are often not recognized by patients and their physicians, the symptomatic, blood pressure, and electrocardiographic responses to exercise can help identify patients who would benefit from early valve repair or replacement. In addition, stress echocardiography has emerged as an important component of stress testing in patients with valvular heart disease, with relevant established and potential applications. Stress echocardiography has the advantages of its wide availability, low cost, and versatility for the assessment of disease severity. The versatile applications of stress echocardiography can be tailored to the individual patient with aortic or mitral valve disease, both before and after valve replacement or repair. Hence, exercise-induced changes in valve hemodynamics, ventricular function, and pulmonary artery pressure, together with exercise capacity and symptomatic responses to exercise, provide the clinician with diagnostic and prognostic information that can contribute to subsequent clinical decisions. Nevertheless, there is a lack of convincing evidence that the results of stress echocardiography lead to clinical decisions that result in better outcomes, and therefore large-scale prospective randomized studies focusing on patient outcomes are needed in the future. [less ▲]

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See detailSurveillance en ligne d'une machine tournante par thermographie infrarouge
Leemans, Vincent ULg; Destain, Marie-France ULg

Conference (2009, December 07)

Des mesures par thermographie d'une machine tournante critique (ventilateur) sont réalisées en ligne pour évaluer la température d’organes, comme le moteur et les paliers. En conditions de fonctionnement ... [more ▼]

Des mesures par thermographie d'une machine tournante critique (ventilateur) sont réalisées en ligne pour évaluer la température d’organes, comme le moteur et les paliers. En conditions de fonctionnement normal, les températures montrent des variations importantes, caractérisées par un écart­-type de l’ordre de 5 °C. Elles sont liées aux variations de conditions climatiques et à l'apport de chaleur variable en fonction du processus de fabrication. Un modèle auto­récurrent avec grandeurs d'entrée (ARX) a permis d'éliminer ces variations. Le bruit sur la température corrigée est réduit à un degré Celsius, ce qui permet de mettre en évidence très tôt une dégradation au niveau des paliers principaux. Par contre, dans le cas présent, le moteur subit un encrassement et donc une augmentation de température en cours de fonctionnement qui masque l’existence d’une éventuelle détérioration. [less ▲]

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See detailSynthesis of glucose-responsive hollow capsules
Alaimo, David ULg; Detrembleur, Christophe ULg; Auzély-Velty, Rachel et al

Poster (2009, December 07)

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See detailL'influence de la fréquence d'occurrence sur l'abstraction des schémas de construction linguistiques chez les enfants dysphasiques
Leroy, Sandrine ULg; Moulin, Mélissa; Parisse, Christophe et al

Poster (2009, December 04)

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See detailMiscellanea palaeontologica
Gerrienne, Philippe ULg; Petus, Elodie ULg; Steemans, Philippe ULg

Book published by Paléogéobio. Paléobot. Paléopalyno. (2009)

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See detailRépétition de non-mots et rappel sériel immédiat : Des mesures équivalentes de la mémoire à court terme verbale?
Leclercq, Anne-Lise ULg; Majerus, Steve ULg

Poster (2009, December 04)

En psychologie expérimentale et en neuropsychologie, les mesures classiques pour évaluer la mémoire à court terme verbale (MCTV) sont des tâches de rappel sériel immédiat (empan de chiffres ou de mots ... [more ▼]

En psychologie expérimentale et en neuropsychologie, les mesures classiques pour évaluer la mémoire à court terme verbale (MCTV) sont des tâches de rappel sériel immédiat (empan de chiffres ou de mots). Il a été démontré que cette même MCTV prédit les capacités de développement lexical, mais sur base d’une estimation de la MCTV à partir de tâches de répétition de non-mots. Même si ces deux procédures (répétition de non-mots, rappel sériel immédiat) sont censées mesurer la MCTV de façon équivalente, la répétition de non-mots recrute davantage de processus linguistiques tels que la segmentation phonologique et la coarticulation (Gathercole, 2006; Majerus, Van der Linden, Mulder, Meulemans, & Peters, 2004). Le but de cette étude est de déterminer dans quelle mesure ces deux types d’estimation de la MCTV sont des prédicteurs équivalents du développement lexical. Des tâches de rappel de syllabes présentées soit de manière sérielle (chaque syllabe étant séparée par une pause), soit de manière agglutinée (= répétition de non-mots) ont été administrées à des enfants de 4, 5, 6 et 8 ans (N=30 dans chaque groupe). Le niveau de vocabulaire a été évalué par le test EVIP (Dunn, Thériault-Whalen, & Dunn, 1993). Une analyse de variance sur les performances aux tâches de MCTV a montré un effet de l’âge (F(3,116)=26.87, p<.001) et un effet du type de tâche, avec de meilleures performances pour les syllabes présentées de façon agglutinée (F(1,116)=390.85, p<.001). Une analyse de régression sur le niveau de vocabulaire a indiqué qu’à la fois la répétition de non-mots et le rappel de séries de syllabes sont des prédicteurs significatifs, après contrôle de l’âge et du niveau intellectuel non-verbal. En outre, la répétition de non-mots reste un prédicteur significatif du niveau de vocabulaire après contrôle du rappel sériel de syllabes (Δ R²=.016). La relation inverse n’est pas significative. Cette étude montre que la répétition de non-mots et le rappel sériel immédiat ne reflètent pas des mesures identiques de la MCTV, et que la prédiction la plus robuste du niveau de vocabulaire est observée pour les tâches de MCTV recrutant un maximum de processus linguistiques. [less ▲]

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See detailRétention de l’ordre sériel en mémoire verbale à court-terme chez des adultes dyslexiques
Martinez Perez, Trecy ULg; Poncelet, Martine ULg; Majerus, Steve ULg

Poster (2009, December 04)

Les difficultés en mémoire verbale à court terme (MCTV) chez les dyslexiques sont interprétées comme le reflet de représentations phonologiques déficitaires (voir Snowling, 2000). Cependant, leurs ... [more ▼]

Les difficultés en mémoire verbale à court terme (MCTV) chez les dyslexiques sont interprétées comme le reflet de représentations phonologiques déficitaires (voir Snowling, 2000). Cependant, leurs capacités en MCTV sont généralement évaluées au moyen de tâches classiques (tâches d'empan) qui ne permettent pas de dissocier le stockage de l'information relative à l'identité des items (information « item ») du stockage de l'information concernant l'ordre de présentation de ces items (information « ordre sériel ») (Majerus et al., 2006). Or, ces deux aspects de la MCTV pourraient être différentiellement liés à l'apprentissage du langage écrit et être tous deux déficitaires dans la dyslexie. L’objectif de cette étude est de déterminer si les dyslexiques présentent des difficultés en MCTV non seulement pour l'information « item » mais également pour l'ordre sériel.  [less ▲]

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See detailLes TFE en didactique des langues et littératures modernes à l'ULg. Vers une "communauté de chercheurs"
Simons, Germain ULg

Diverse speeche and writing (2009)

Depuis 2007, le service de didactique des langues et littératures modernes de l'ULg organise des séances de "mémorants" dans le domaine de la didactique des langues étrangères. Cette communication décrit ... [more ▼]

Depuis 2007, le service de didactique des langues et littératures modernes de l'ULg organise des séances de "mémorants" dans le domaine de la didactique des langues étrangères. Cette communication décrit le dispositif mis en place et propose quelques éléments d'évaluation. [less ▲]

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See detailPRIX WALLON DE LA QUALITE 2009 : « La Qualité : ombre et lumière »
LEROY, Dominique; DELGAUDINE, Marie ULg

Article for general public (2009)

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See detailRecurrent energization of plasma in the midnight-to-dawn quadrant of Saturn's magnetosphere, and its relationship to auroral UV and radio emissions
Mitchell, D. G.; Krimigis, S. M.; Paranicas, C. et al

in Planetary and Space Science (2009), 57

We demonstrate that under some magnetospheric conditions protons and oxygen ions are accelerated once per Saturn magnetosphere rotation, at a preferred local time between midnight and dawn. Although ... [more ▼]

We demonstrate that under some magnetospheric conditions protons and oxygen ions are accelerated once per Saturn magnetosphere rotation, at a preferred local time between midnight and dawn. Although enhancements in energetic neutral atom (ENA) emission may in general occur at any local time and at any time in a Saturn rotation, those enhancements that exhibit a recurrence at a period very close to Saturn's rotation period usually recur in the same magnetospheric location. We suggest that these events result from current sheet acceleration in the 15-20 Rs range, probably associated with reconnection and plasmoid formation in Saturn's magnetotail. Simultaneous auroral observations by the Hubble Space Telescope (HST) and the Cassini Ultraviolet Imaging Spectrometer (UVIS) suggest a close correlation between these dynamical magnetospheric events and dawn-side transient auroral brightenings. Likewise, many of the recurrent ENA enhancements coincide closely with bursts of Saturn kilometric radiation, again pointing to possible linkage with high latitude auroral processes. We argue that the rotating azimuthal asymmetry of the ring current pressure revealed in the ENA images creates an associated rotating field aligned current system linking to the ionosphere and driving the correlated auroral processes. [less ▲]

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See detailVirtual model of the city of Liège in the eighteen century - "Virtual Leodium"
Billen, Roland ULg; Blain, Pascal ULg; Donneau, Olivier ULg et al

in Verly, Jacques (Ed.) Proceedings of 3D Stereo MEDIA 2009, International 3D Stereo Film and Technology Festival (3D Stereo MEDIA), Liège, Belgium, 1-3 Dec. 2009. (2009, December 01)

Virtual Leodium is a project aiming to scan and digitize a master piece of the collection of the University of Liège, the historical model of the city of Liège around 1730 realised by Gustave Ruhl. The ... [more ▼]

Virtual Leodium is a project aiming to scan and digitize a master piece of the collection of the University of Liège, the historical model of the city of Liège around 1730 realised by Gustave Ruhl. The two main originalities of the approach are to use a projected-fringes scanning technique and to generate a geo-database as a support for archaeological information. This interdisciplinary project gathers physicists, geomaticians, librarians, and archaeologists. [less ▲]

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