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See detailDie belgisch-deutschen diplomatischen Beziehungen 1949-1991
Brüll, Christoph ULg

Speech/Talk (2009)

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See detailExozodiacal discs with ALADDIN: how deep can we go?
Absil, Olivier ULg

Scientific conference (2009, May 12)

Studying the warm inner part of debris discs—-the extrasolar counterparts of the zodiacal dust cloud-—is of prime importance to characterise the global architecture of planetary systems. Furthermore, the ... [more ▼]

Studying the warm inner part of debris discs—-the extrasolar counterparts of the zodiacal dust cloud-—is of prime importance to characterise the global architecture of planetary systems. Furthermore, the possible presence of large quantities of warm dust around nearby main sequence stars is unanimously recognised as a major threat for future space missions dedicated to the direct detection and characterisation of Earth-like planets (either with visible/near-IR coronagraphy or mid-infrared interferometry). As of today, exozodiacal discs have been directly resolved around very few main sequence stars, at a sensitivity level of about 1000 times our zodiacal dust cloud. In this context, the ALADDIN project aims at detecting warm dust populations around nearby main sequence stars with significantly improved sensitivity. In this paper, we present a thorough study of ALADDIN's estimated performance. End-to-end simulations taking into account the specific characteristics of the Antarctic environment have been carried out, showing that a nulling interferometer coupled to a pair of 1-m class telescopes in Antarctica would perform significantly better than a similar instrument working on 8-m class telescopes in a temperate site. Exozodiacal dust density levels as low as 50 times the Solar zodiacal cloud are within reach around most Solar-type stars within 25 pc. Such performance would bring the study of exozodiacal light to a new level, and enable a fine study of terrestrial planet environments. Suitable candidate targets for direct Earth-like planet detection could then be identified among nearby main sequence stars in the Southern hemisphere, and the design of future space missions tuned to cope with the statistical occurrence of bright exozodiacal discs. [less ▲]

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See detailDetecting Triangle Inequality Violations in Internet Coordinate Systems by Supervised Learning
Liao, Yongjun ULg; Kaafar, Mohamed Ali; Gueye, Bamba et al

in Lecture Notes in Computer Science (2009, May 12), 5550

Internet Coordinates Systems (ICS) are used to predict Internet distances with limited measurements. However the precision of an ICS is degraded by the presence of Triangle Inequality Violations (TIVs ... [more ▼]

Internet Coordinates Systems (ICS) are used to predict Internet distances with limited measurements. However the precision of an ICS is degraded by the presence of Triangle Inequality Violations (TIVs). Simple methods have been proposed to detect TIVs, based e.g. on the empirical observation that a TIV is more likely when the distance is underestimated by the coordinates. In this paper, we apply supervised machine learning techniques to try and derive more powerful criteria to detect TIVs. We first show that (ensembles of) Decision Trees (DTs) learnt on our datasets are very good models for this problem. Moreover, our approach brings out a discriminative variable (called OREE), which combines the classical estimation error with the variance of the estimated distance. This variable alone is as good as an ensemble of DTs, and provides a much simpler criterion. If every node of the ICS sorts its neighbours according to OREE, we show that cutting these lists after a given number of neighbours, or when OREE crosses a given threshold value, achieves very good performance to detect TIVs. [less ▲]

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See detailSupporting cell cytoskeleton during development of the organ of Corti in rat
Johnen, Nicolas ULg; Thelen, Nicolas ULg; Malgrange, Brigitte ULg et al

Poster (2009, May 11)

The mammalian auditory organ, the organ of Corti (OC), is composed of mechanosensory hair cells and nonsensory supporting cell types. Based on their morphology and physiology, a least four types of ... [more ▼]

The mammalian auditory organ, the organ of Corti (OC), is composed of mechanosensory hair cells and nonsensory supporting cell types. Based on their morphology and physiology, a least four types of supporting cells can be identified in the OC: inner pillar cell, outer pillar cell, phalangeal cell and Deiter’s cells. All supporting cells are highly specialized cells that are characterized by the presence of bundled microtubules with 15 protofilaments instead of 13. Using antibobies against different proteins of cytoskeleton (tubulin, cutokeratin and vimentin), we investigated by confocal microscopy the setting up of supporting cells' cytoskeleton during the differentiation of the OC in art from the embryonic day 18 (E18) to the postnatal 15 (P15). We showed that the inner pillar cells are labelled with an anti-beta IV tubulin from P0. Using an antibody to cytokeratin, a labelling appeared in Deiters' cells from E22. We also revealed that during the development of the OC, supporting cells were labelled with an anti-vimentin antibody from P0. [less ▲]

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See detailObserver l’écoute : du paradoxe à l’enquête
Colon, Paul-Louis ULg

Conference (2009, May 11)

La communication faisait un état critique des techniques d'observation de la perception auditive qui tiennent compte de sa dimension sociale et culturelle.

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See detailHow much more Economics is the New Approach ?
Sibony, Anne-Lise ULg

Conference (2009, May 11)

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See detailMulti-Criteria Decision Support for Cost Assessment Techniques in Shipbuilding Industry
Caprace, Jean-David ULg; Rigo, Philippe ULg

in COMPIT'09, Budapest (2009, May 10)

Cost is perhaps the most influential factor in the outcome of a product or service within many of today’s industries. Cost assessment during the early stage of ship design is crucial. It influences the go ... [more ▼]

Cost is perhaps the most influential factor in the outcome of a product or service within many of today’s industries. Cost assessment during the early stage of ship design is crucial. It influences the go, no-go decision concerning a new development. Cost assessment occurs at various stages of ship design development. Economic evaluation as early as possible, in the design phase, is therefore crucial to find the best price–function compromise for the ship projects. This paper presents a Multi Criteria Decision Aid (MCDA) method in order to select an appropriate cost assessment method at each stage of the ship design. In order to compare the cost performance between all alternatives, the evaluation of each alternative is performed by PROMETHEE. [less ▲]

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See detailSpace Allocation Optimization Applied to Lower Hulls’ Production of Semi-Submersible Platforms
Caprace, Jean-David ULg; Marins, Cassiano; Losseau, Nicolas ULg et al

in COMPIT'09 (2009, May 10)

This paper presents a part of new developments included inside a holistic optimisation strategy during the design cycle of ships. The first part of the paper describes an algorithm to maximize the number ... [more ▼]

This paper presents a part of new developments included inside a holistic optimisation strategy during the design cycle of ships. The first part of the paper describes an algorithm to maximize the number of ship blocks and ship sections to produce in workshops during a certain time window. A tool was developed in order to support planners to improve the space utilization and workshop productivity. Thanks to this software, the scheduling is now done more efficiently and above all it takes less time. The second part of the paper describes a recent development of an algorithm able to generate a feasible blocks erection sequence starting from the blocks splitting definition. The idea is to integrate this module as a new functionality inside simulation software in order to take into account blocks sequence during the elaboration of the optimised production strategy. The two developments were validated on the lower hull of a semi-submersible platform coming from a new Brazilian shipyard. [less ▲]

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See detailCoeur et Diabète. Objectifs de prévention cardiovasculaire
RADERMECKER, Régis ULg

Conference (2009, May 09)

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See detailLe training chirurgical du médecin généraliste
Belche, Jean ULg

Conference (2009, May 09)

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See detailLangues modernes : concevoir une séquence d'apprentissage pour le 1er degré commun, le 1er degré différencié et le 2e degré de l'enseignement qualifiant. Des séquences didactiques en référence aux prescrits légaux et aux styles d'apprentissage des élèves. 2e partie
Simons, Germain ULg; Delbrassine, Daniel ULg; Pagnoul, Pierre ULg et al

Learning material (2009)

Cette formation a été réalisée pour l'Institut de la Formation en Cours de Carrière (I.F.C.) et ciblait les enseignants de langues modernes. Cette journée du 08/05/2009 est la seconde partie d'une ... [more ▼]

Cette formation a été réalisée pour l'Institut de la Formation en Cours de Carrière (I.F.C.) et ciblait les enseignants de langues modernes. Cette journée du 08/05/2009 est la seconde partie d'une formation en deux journées (voir référence du 24 avril 2009). Cette journée était composée de quatre grands volets. Dans le premier volet, nous avons présenté deux nouveaux exemples de plans de séquences didactiques articulés autour du double concept de situation-problème et d'apprentissage expérientiel. Dans le deuxième volet, nous avons présenté un dispositif ("l'aquarium") permettant d'optimaliser la participation d'un maximum d'élèves lors d'une activité de production orale. Dans le 3e volet, nous avons présenté différents outils de diagnostic et de remédiation issus d'une recherche collaborative menée entre 2007 et 2009. Dans le quatrième volet, les participants ont présenté les expérimentations qu'ils ont réalisées dans leurs propores classes. [less ▲]

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See detailGenotype by Environment Interaction for Production Traits of Holsteins Using Two Countries as Model: Luxembourg and Tunisia
Hammami, Hedi ULg

Doctoral thesis (2009)

Under globalization, breeding organizations are selecting animals and exchanging germplasm across various environments. Ignoring genotype by environment interaction (G x E) may affect the efficiency of ... [more ▼]

Under globalization, breeding organizations are selecting animals and exchanging germplasm across various environments. Ignoring genotype by environment interaction (G x E) may affect the efficiency of breeding strategies and limit outcomes from cooperation between breeding programs. Quantifying the effectiveness of indirect selection and effects of G x E for different breeds is therefore necessary. The objective of this thesis was to evaluate the magnitude of G x E for milk yield using Luxembourg and Tunisian Holstein populations. In fact, these two countries rely considerably on importation of superior genes from diverse origins for their breeding programs. This study needed records on both the genotype and the environment. In the first part of this thesis, genetic ties between the two populations were studied. Additive relationships and genetic similarity were important and genetic links have been strengthened with time which allowed the analysis of the phenotypic expression of daughters of common sires under each of these tow production environments. In the second part, genetic parameters for production traits of Tunisian Holsteins were estimated by a test-day random regression model (RRTD). Heritability estimates for 305-d milk, fat and protein yields were low to moderate (0.12 to 0.18) suspecting difficulties of high-producing cows to express their potential under limiting production conditions. In the third part, G x E for milk yield and persistency were investigated using character state models, where milk yield in each country was considered as a separate trait, and where the country border delimitation was designed as an environmental character state. A RRTD sire model was applied and was extended to a RRTD animal model. Significant G x E was detected for milk yield and persistency by both models. Large differences in genetic and permanent environmental variances between the two countries were observed. Genetic correlations for 305-d milk yield and persistency between Luxembourg and Tunisian Holsteins were 0.50 and 0.43 (sire model) and 0.60 and 0.36 (animal model). Moreover, low rank correlations obtained between estimated breeding values of common sires translate a significant re-ranking between the two environments. At the end of this thesis, a herd management (HM) parameter reflecting feeding and management intensity was defined. Three HM levels were identified in each country and G x E was investigated within- and across-environments. Significant G x E was detected between the Tunisian HM levels, whereas, only heterogeneous genetic variance for milk yield with limited re-ranking of sires across the three Luxembourg environments was observed. Overall, this thesis shows that under constraining environmental effects, selection for adaptive traits among economically valuable traits under their specific conditions is needed for low-input systems. When satisfactory feeding resources, management and husbandry practices are available, high degree environmental sensitivity is desired and the use of a high yielding breed may be encouraged. [less ▲]

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See detailEntomologie forensique - Insectes et odeurs cadavériques
Dekeirsschieter, Jessica ULg; Haubruge, Eric ULg

Conference given outside the academic context (2009)

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See detailThe effect of using genetic diversity of wheat varieties for ecological regulation on Sitobion avenae.
Zhou, Haibo ULg

in Acta Phytophylacica Sinica (2009), 36(2), 151-156

To study the ecological effect of genetic diversity in wheat field on Sitobion avenae. the population dynamic of S. avenae and it’s natural enemies was investigated systematically in wheat fields, the ... [more ▼]

To study the ecological effect of genetic diversity in wheat field on Sitobion avenae. the population dynamic of S. avenae and it’s natural enemies was investigated systematically in wheat fields, the spatial distribution of S. avenae.was also analyzed.The results showed that, compared with monocultures, cv. Beijing 837, the amount of S. avenae apterae per 100 plants in intercropping pattern were significantly lower during aphid peak period, and the cascade of population densities was that cv. Beijing 837 monoculture(7422.0) > intercropped with cv. KOK(5796.7) > intercropped with cv. Hongmanghong(5406.7) > intercropped with cv. Zhengzhou831(5291.7) > intercropped with cv. JP2(4493.4) > intercropped with cv. Zhongsiwumang(4155.0),,and the spatial distribution of S. avenae were changed from aggregated pattern to uniform one. In aphid parasitoids peak period, there were higher population densities of aphid parasitoids in each intercropping field with the very significant level of P<0.01. The theoretical yield were more increasing with the significant level of P<0.05. Above all, the intercropping of wheat varieties of different resistance to aphids with the field cultivar could own an obvious advantage in ecological regulation to S. avenae. [less ▲]

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See detailThe spin-orbit alignment of the Fomalhaut planetary system probed by optical long baseline interferometry
Le Bouquin, J.-B.; Absil, Olivier ULg; Benisty, M. et al

in Astronomy and Astrophysics (2009), 498

Aims. We discuss the spin-orbit orientation of the Fomalhaut planetary system composed of a central A4V star, a debris disk, and a recently discovered planetary companion. Methods: We use spectrally ... [more ▼]

Aims. We discuss the spin-orbit orientation of the Fomalhaut planetary system composed of a central A4V star, a debris disk, and a recently discovered planetary companion. Methods: We use spectrally resolved, near-IR long baseline interferometry to obtain precise spectro-astrometric measurements across the Br-gamma absorption line. The achieved astrometric accuracy of ±3 muas and the spectral resolution R=1500 from the AMBER/VLTI instrument allow us to spatially and spectrally resolve the rotating photosphere. Results: We find a position angle PA(star)=65° ± 3° for the stellar rotation axis, perpendicular to the literature measurement for the disk position angle (PA(disk)=156.0 ° ± 0.3°). This is the first time such a test could be performed for a debris disk, and in a non-eclipsing system. Additionally, our measurements suggest unexpected backward-scattering properties for the circumstellar dust grains. Conclusions: Our observations validate the standard scenario for star and planet formation in which the angular momentum of the planetary systems are expected to be colinear with the stellar spins. Based on observations collected at the VLTI (ESO Paranal, Chile), with the 082.C-0376 program from the AMBER Guaranteed Time of the Osservatorio Astrofisico di Arcetri (INAF, Italy). [less ▲]

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See detailResponse of Jupiter's and Saturn's auroral activity to the solar wind
Clarke, J. T.; Nichols, J.; Gérard, Jean-Claude ULg et al

in Journal of Geophysical Research. Space Physics (2009), 114

While the terrestrial aurorae are known to be driven primarily by the interaction of the Earth's magnetosphere with the solar wind, there is considerable evidence that auroral emissions on Jupiter and ... [more ▼]

While the terrestrial aurorae are known to be driven primarily by the interaction of the Earth's magnetosphere with the solar wind, there is considerable evidence that auroral emissions on Jupiter and Saturn are driven primarily by internal processes, with the main energy source being the planets' rapid rotation. Prior observations have suggested there might be some influence of the solar wind on Jupiter's aurorae and indicated that auroral storms on Saturn can occur at times of solar wind pressure increases. To investigate in detail the dependence of auroral processes on solar wind conditions, a large campaign of observations of these planets has been undertaken using the Hubble Space Telescope, in association with measurements from planetary spacecraft and solar wind conditions both propagated from 1 AU and measured near each planet. The data indicate a brightening of both the auroral emissions and Saturn kilometric radiation at Saturn close in time to the arrival of solar wind shocks and pressure increases, consistent with a direct physical relationship between Saturnian auroral processes and solar wind conditions. At Jupiter the correlation is less strong, with increases in total auroral power seen near the arrival of solar wind forward shocks but little increase observed near reverse shocks. In addition, auroral dawn storms have been observed when there was little change in solar wind conditions. The data are consistent with some solar wind influence on some Jovian auroral processes, while the auroral activity also varies independently of the solar wind. This extensive data set will serve to constrain theoretical models for the interaction of the solar wind with the magnetospheres of Jupiter and Saturn. [less ▲]

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See detailA Multi-Wavelength Simultaneous Study of the Composition of the Halley Family Comet 8P/Tuttle
Jehin, Emmanuel ULg; Bockelée-Morvan, Dominique; Dello Russo, N. et al

in Earth, Moon, and Planets (2009), 105

We report on simultaneous optical and infrared observations of the Halley Family comet 8P/Tuttle performed with the ESO Very Large Telescope. Such multi-wavelength and coordinated observations are a good ... [more ▼]

We report on simultaneous optical and infrared observations of the Halley Family comet 8P/Tuttle performed with the ESO Very Large Telescope. Such multi-wavelength and coordinated observations are a good example of what can be done to support space missions. From high resolution optical spectroscopy of the CN (0,0) 388 nm and NH[SUB]2[/SUB] (0,9,0) 610 nm bands using UVES at UT2 we determined [SUP]12[/SUP]C/[SUP]13[/SUP]C = 90 ± 10 and [SUP]14[/SUP]N/[SUP]15[/SUP]N = 150 ± 20 in CN and we derived a nuclear spin temperature of NH[SUB]3[/SUB] of 29 ± 1 K. These values are similar to those found in Oort-Cloud and Jupiter Family comets. From low resolution long slit spectroscopy with FORS1 at UT2 we determined the CN, C[SUB]3[/SUB] and C[SUB]2[/SUB] production rates and the parent and daughter scale lengths up to 5.2 10[SUP]5[/SUP] km tailward. From high resolution IR spectroscopy with CRIRES at UT1 we measured simultaneously the production rates and mixing ratios of H[SUB]2[/SUB]O, HCN, C[SUB]2[/SUB]H[SUB]2[/SUB], CH[SUB]4[/SUB], C[SUB]2[/SUB]H[SUB]6[/SUB], and CH[SUB]3[/SUB]OH. [less ▲]

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