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See detailCombiner les mesures métaboliques cérébrales et neuropsychologiques permet une meilleure prédiction de la conversion vers une maladie d’Alzheimer chez les patients MCI
Bastin, Christine ULg; Adam, Stéphane ULg; LEKEU, Françoise ULg et al

in Revue Neurologique (2009), 165

Introduction. Une voie de recherche neurologique importante concerne la capacité de prédire sur base de l’évaluation initiale des patients avec Mild Cognitive Impairment (MCI) ceux qui vont développer une ... [more ▼]

Introduction. Une voie de recherche neurologique importante concerne la capacité de prédire sur base de l’évaluation initiale des patients avec Mild Cognitive Impairment (MCI) ceux qui vont développer une maladie d’Alzheimer (MA). Parmi les tests neuropsychologiques, le rappel indicé avec indiçage congruent lors de l’encodage et du rappel (RI48) apparaît comme le meilleur prédicteur du devenir des patients MCI (Ivanoiu et al., 2005). D’autre part, on a montré que les mesures métaboliques cérébrales (TEP-FDG), plus particulièrement l’hypométabolisme du cortex temporopariétal, prédit le déclin cognitif global dans le MCI mieux que des mesures neuropsychologiques (Chételat et al., 2005). Le but de notre étude était d’évaluer le pouvoir de prédiction pour la conversion du MCI vers une MA de deux prédicteurs robustes (performance au RI48 et métabolisme cérébral) pris soit isolément soit ensemble. Méthode. 50 patients MCI ont subi un examen en TEP-FDG au repos et ont réalisé le test de rappel indicé RI48 et le MMSE. Au terme d’un suivi neuropsychologique de 36 mois, 28 patients ont évolué vers une MA et 22 sont restés stables. Le métabolisme cérébral et les performances cognitives ont été comparés entre « convertisseurs » et MCI-stables. Des analyses discriminantes ont ensuite permis d’évaluer la capacité de classification de l’âge, du MMSE et des mesures métaboliques et mnésiques considérés individuellement ou selon diverses combinaisons. Résultat. Par comparaison avec les MCI-stables, les « convertisseurs » montraient un hypométabolisme du cortex temporal moyen bilatéralement, du cortex pariétal inférieur droit et du précuneus droit, et de plus faibles performances initiales au RI48. Prises individuellement, les différentes mesures permettaient le même taux de classification correcte (métabolisme cérébral = 76%, RI48 = 76%). L’âge et le MMSE étaient de faibles prédicteurs (exactitude de classification = 62% et 66% respectivement). Par contre, la combinaison des mesures métaboliques et des scores au RI48 prédisaient le mieux la progression vers la MA (88%). Conclusion. Les résultats suggèrent que la stratégie optimale pour identifier quels patients MCI ont plus de risque de développer une MA est de combiner les mesures métaboliques cérébrales et la performance à un test de mémoire très sensible. [less ▲]

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See detailCombiner sport et études. Comment cela est-il vécu ?
Cloes, Marc ULg

Scientific conference (2004, October 16)

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See detailCombining a stability and a performance-oriented control in power systems
Glavic, M.; Ernst, Damien ULg; Wehenkel, Louis ULg

in IEEE Transactions on Power Systems (2005), 20(1), 525-526

This paper suggests that the appropriate combination of a stability-oriented and a performance-oriented control technique is a promising way to implement advanced control schemes in power systems. The ... [more ▼]

This paper suggests that the appropriate combination of a stability-oriented and a performance-oriented control technique is a promising way to implement advanced control schemes in power systems. The particular approach considered combines control Lyapunov functions (CLF) and reinforcement learning. The capabilities of the resulting controller are illustrated on a control problem involving a thyristor-controlled series capacitor (TCSC) device for damping oscillations in a four-machine power system. [less ▲]

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See detailCombining Active Learning and Reactive Control for Robot Grasping
Kroemer, Oliver; Detry, Renaud ULg; Piater, Justus ULg et al

in Robotics and Autonomous Systems (2010)

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See detailCombining an original method for preserving RNA expression in situ with an effetive RNA method makes it possible to study gene expression in any banana fruit tissue.
Lassois, Ludivine ULg; de Lapeyre de Bellaire, Luc; Jijakli, Haissam ULg

in Fruits (2009), 64(3), 127-137

Introduction. RNA isolation is a prerequisite to studying gene expression in banana and to understanding changes occurring in response to the environment. Standard extraction methods do not efficiently ... [more ▼]

Introduction. RNA isolation is a prerequisite to studying gene expression in banana and to understanding changes occurring in response to the environment. Standard extraction methods do not efficiently extract RNA from plants such as banana, with high levels of phenolics, carbohydrates, or other compounds that bind to and/or coprecipitate with RNA. Materials and methods. Five to seven RNA extraction methods were compared. Four crowntissue storage methods were also compared. cDNA-AFLP was used to ensure that the obtained RNA was of sufficient quality for molecular applications and that RNA expression was unaltered by in situ storage. Results and discussion. The modified hot-borate method proved to be the best RNA extraction method, allowing high yields of good quality, undegraded RNA from the crown, fruit peel and pulp at all stages of ripening. The RNA obtained by this method was of sufficient quality for molecular applications such as cDNA-AFLP that give highly reproducible results. Freeze-drying of fresh tissues and tissue conservation in hot-borate buffer, two original storage methods, appear appropriate for preserving RNA in situ without ultra-low temperature. The RNA obtained was of high quality, undegraded, and useful for all downstream applications. The genome expression profile obtained by cDNA-AFLP analysis was unaltered by these methods for storing collected tissues. Conclusion. By applying all the suggested procedures in this work, it is possible to store and study gene expression in any banana fruit tissue, whatever the maturity stage, without affecting the RNA expression level. [less ▲]

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See detailCombining classification techniques with Kalman filters for aircraft engine diagnostics
Dewallef, Pierre ULg; Romessis, C.; Léonard, Olivier ULg et al

in Journal of Engineering for Gas Turbines & Power (2006), 128(2), 281-287

A diagnostic method consisting of a combination of Kalman filters and Bayesian Belief Network (BBN) is presented. A soft-constrained Kalman filter uses a priori information derived by a BBN at each time ... [more ▼]

A diagnostic method consisting of a combination of Kalman filters and Bayesian Belief Network (BBN) is presented. A soft-constrained Kalman filter uses a priori information derived by a BBN at each time step, to derive estimations of the unknown health parameters. The resulting algorithm hers improved identification capability in comparison to the stand-alone Kalman filter. The paper focuses on a way of combining the information produced by the BBN with the Kalman filter. An extensive set of fault cases is used to test the method on a typical civil turbofan layout. The effectiveness of the method is thus demonstrated, and its advantages over individual constituent methods are presented. [less ▲]

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See detailCombining classification techniques with Kalman filters for aircraft engine diagnostics
Dewallef, Pierre ULg; Léonard, Olivier ULg; Mathioudakis, Kostas et al

in Proceedings of the ASME Turbo Expo 2004 (2004, June)

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See detailCombining Color, Depth, and Motion for Video Segmentation
Leens, Jérôme ULg; Pierard, Sébastien ULg; Barnich, Olivier ULg et al

in Computer Vision Systems (2009, October)

This paper presents an innovative method to interpret the content of a video scene using a depth camera. Cameras that provide distance instead of color information are part of a promising young technology ... [more ▼]

This paper presents an innovative method to interpret the content of a video scene using a depth camera. Cameras that provide distance instead of color information are part of a promising young technology but they come with many diff culties: noisy signals, small resolution, and ambiguities, to cite a few. By taking advantage of the robustness to noise of a recent background subtraction algorithm, our method is able to extract useful information from the depth signals. We further enhance the robustness of the algorithm by combining this information with that of an RGB camera. In our experiments, we demonstrate this increased robustness and conclude by showing a practical example of an immersive application taking advantage of our algorithm. [less ▲]

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See detailCombining Coronagraphy with Interferometry as a Tool for Measuring Stellar Diameters
Riaud, P.; Hanot, Charles ULg

in Astrophysical Journal (2010)

The classical approach for determining stellar angular diameters is to use interferometry and to measure fringe visibilities. Indeed, in the case of a source having a diameter larger than typically λ/6B ... [more ▼]

The classical approach for determining stellar angular diameters is to use interferometry and to measure fringe visibilities. Indeed, in the case of a source having a diameter larger than typically λ/6B, B being the interferometer's baseline and λ the wavelength of observation, the fringe contrast decreases. Similarly, it is possible to perform angular diameter determinations by measuring the stellar leakage from a coronagraphic device or a nulling interferometer. However, all coronagraphic devices (including those using nulling interferometry) are very sensitive to pointing errors and to the size of the source, two factors with significant impact on the rejection efficiency. In this work, we present an innovative idea for measuring stellar diameter variations, combining coronagraphy together with interferometry. We demonstrate that, using coronagraphic nulling statistics, it is possible to measure such variations for angular diameters down to ≈λ/40B with 1σ error-bars as low as ≈λ/1500B. For that purpose, we use a coronagraphic implementation on a two-aperture interferometer, a configuration that significantly increases the precision of stellar diameter measurements. Such a design offers large possibilities regarding the stellar diameter measurement of Cepheids or Mira stars, at a 60-80 μas level. We report on a simulation of a measurement applied to a typical Cepheid case, using the VLTI-UT interferometer on Paranal. [less ▲]

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See detailCombining Feed, Food and Non-Food Uses of Lupin for Sustainability
Froidmont, E.; Delcarte, J.; Wathelet, Jean-Paul ULg et al

in III International Scientific Symposium "Farm Machinery and Process Management in Sustainable Agriculture (2008)

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See detailCombining Full Transients and Phasor Approximation Models in Power System Time Simulation
Plumier, Frédéric ULg; Fabozzi, Davide ULg; Geuzaine, Christophe ULg et al

in Proceedings of the 21th International Conference on Domain Decomposition Methods (DD21) (2012, June)

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See detailCombining in vivo and in silico experiments to unravel root water uptake dynamics
Lobet, Guillaume ULg; Bhowmick, Suman; Couvreur, Valentin et al

Poster (2012)

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See detailCombining intercropping with semiochemical releases: optimization of alternative control of Sitobion avenae 1 in wheat crops in China
Wang, Guang; Cui, Liang-Liang; Dong, Jie et al

in Entomologia Experimentalis et Applicata (2011)

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See detailCombining Ionosonde and GPS TEC Data to Assess NeQuick Formulation
Bidaine, Benoît ULg

Report (2008)

The main topic which was investigated during the mission is related to the validation of the NeQuick model using different data sets. The discussions were based on former work dealing with the comparison ... [more ▼]

The main topic which was investigated during the mission is related to the validation of the NeQuick model using different data sets. The discussions were based on former work dealing with the comparison of the first version of the model recommended by the ITU-R and its second version recently published. In addition the NeQuick formulation and its physical behaviour were discussed considering the bottomside and topside representations and the interaction between both. This will constitute the basis for future investigation of ingestion techniques using NeQuick as well as the ionospheric correction algorithm for Galileo single frequency users. [less ▲]

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See detailCombining lazy learning, racing and subsampling for effective feature selection
Bontempi, Gianluca; Birattari, Mauro; Meyer, Patrick ULg

in Adaptive and Natural Computing Algorithms (2005)

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See detailCombining magnetic and seismic studies to constrain processes in massive stars
Neiner, C.; Degroote, P.; Coste, B. et al

in IAUS 302 - Magnetic Fields Throughout Stellar Evolution (in press)

The presence of pulsations influences the local parameters at the surface of massive stars and thus it modifies the Zeeman magnetic signatures. Therefore it makes the characterisation of a magnetic field ... [more ▼]

The presence of pulsations influences the local parameters at the surface of massive stars and thus it modifies the Zeeman magnetic signatures. Therefore it makes the characterisation of a magnetic field in pulsating stars more difficult and the characterisation of pulsations is thus required for the study of magnetic massive stars. Conversely, the presence of a magnetic field can inhibit differential rotation and mixing in massive stars and thus provides important constraints for seismic modelling based on pulsation studies. As a consequence, it is necessary to combine spectropolarimetric and seismic studies for all massive classical pulsators. Below we show examples of such combined studies and the interplay between physical processes. [less ▲]

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See detailCombining microsatellite and pedigree data to estimate relationships among Skyros ponies.
Bömcke, Elisabeth ULg; Gengler, Nicolas ULg

in Journal of Applied Genetics (2009), 50(2), 133-43

Relationship coefficients are particularly useful to improve genetic management of endangered populations. These coefficients are traditionally based on pedigree data, but in case of incomplete or ... [more ▼]

Relationship coefficients are particularly useful to improve genetic management of endangered populations. These coefficients are traditionally based on pedigree data, but in case of incomplete or inexistent pedigrees they are replaced by coefficients calculated from molecular data. The main objective of this study was to develop a new method to estimate relationship coefficients by combining molecular with pedigree data, which is useful for specific situations where neither pedigree nor molecular data are complete. The developed method was applied to contribute to the conservation of the Skyros pony breed, which consists of less than 200 individuals, divided into 3 main herds or subpopulations. In this study, relationships between individuals were estimated using traditional estimators as well as the newly developed method. For this purpose, 99 Skyros ponies were genotyped at 16 microsatellite loci. It appeared that the limitation of the most common molecular-based estimators is the use of weights that assume relationships equal to 0. The results showed that, as a consequence of this limitation, negative relationship values can be obtained in small inbred populations, for example. By contrast, the combined estimator gave no negative values. Using principal component analysis, the combined estimator also enabled a better graphic differentiation between the 3 subpopulations defined previously. In conclusion, this new estimator can be a promising alternative to traditionally used estimators, especially in inbred populations, with both incomplete pedigree and molecular information. [less ▲]

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See detailCombining Mixed Integer Programming and Supervised Learning for Fast Re-planning
Rachelson, Emmanuel ULg; Ben Abbes, Ala; Diemer, Sébastien

in Proceedings of the 22nd IEEE International Conference on Tools with Artificial Intelligence (2010)

We introduce a new plan repair method for problems cast as Mixed Integer Programs. In order to tackle the inherent complexity of these NP-hard problems, our approach relies on the use of Supervised ... [more ▼]

We introduce a new plan repair method for problems cast as Mixed Integer Programs. In order to tackle the inherent complexity of these NP-hard problems, our approach relies on the use of Supervised Learning method for the offline construction of a predictor which takes the problem’s parameters as input and infers values for the discrete optimization variables. This way, the online resolution time of the plan repair problem can be greatly decreased by avoiding a large part of the combinatorial search among discrete variables. This contribution was motivated by the large-scale problem of intra-daily recourse strategy computation in electrical power systems. We report and discuss results on this benchmark, illustrating the different aspects and mechanisms of this new approach which provided close-to-optimal solutions in only a fraction of the computational time necessary for existing solvers. [less ▲]

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