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See detailLes sans-papiers
Gerkens, Jean-François ULg

Conference given outside the academic context (2009)

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See detailEtude de l’effectif, des déplacements, du domaine vital et de l’utilisation de l’habitat par une population de couleuvres à collier (Natrix natrix helvetica) en zone périurbaine (Liège, Belgique). Implications en termes de conservation.
Graitson, Eric ULg; Pittoors, Julie

Scientific conference (2009, October 30)

Une étude de l’effectif de la population, des déplacements, du domaine vital et de l’utilisation de l’habitat a été réalisée sur des couleuvres à collier (Natrix natrix helvetica), dans le domaine ... [more ▼]

Une étude de l’effectif de la population, des déplacements, du domaine vital et de l’utilisation de l’habitat a été réalisée sur des couleuvres à collier (Natrix natrix helvetica), dans le domaine universitaire du Sart Tilman (Liège, Belgique), entre avril et octobre 2009. L’effectif de la population est estimé à plus de 200 adultes et subadultes par capture-marquage-recapture. Les densités sont très élevées dans une zone noyau ou 130 individus différents ont été capturés sur une surface de 12 hectares. Dix femelles ont étés suivies par télémétrie et ont étés localisées régulièrement (au minimum tous les deux jours). Les habitats les plus fréquentés par les couleuvres à collier sont les milieux de lisières, avec plus de 80% du total des localisations, ainsi que les friches (15%). Les microhabitats les plus prisés sont les ronciers et les végétations rudérales dominées par les orties. La fréquentation des habitats et microhabitats n’est pas homogène au cours du temps : elle se diversifie lorsque la végétation se développe au cours de la saison. Les domaines vitaux sont très réduits par rapport aux chiffres habituellement cités dans la littérature (de l’ordre de 5 hectares en moyenne). Les déplacements de 200m et plus ne sont pas rares, en particulier au mois de juin lorsque les individus rejoignent les sites de pontes. Ils se produisent surtout par temps chaud. La période de ponte a lieu fin juin pour l’ensemble des individus. Les animaux ont rejoints leur site d’hibernation dès la fin septembre. Ceux-ci possèdent des caractéristiques bien particulières : sommets de talus et pentes bien drainées situées en milieu forestier ou dans de petits bosquets. Ils tous pour la plupart situés à proximité du lieu de capture printanière laissant suggérer que les couleuvres utilisent les mêmes sites d’hibernation d’une année à l’autre. Les serpents ont réagis positivement aux aménagements réalisés en leur faveur : les composts aménagés spécifiquement pour la ponte ont été exploités par 6 des 10 individus. Des lisières forestières mises en lumière durant l’hiver ont été fréquentées dès le printemps suivant. [less ▲]

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See detailImproving Teaching: A Need for Combined Strategies
Poumay, Marianne ULg

Scientific conference (2009, October 30)

The presentation will illustrate the efforts of the University of Liège in that new international trend: valorizing good teaching through : • portfolios, • training the teachers (certificates and degree ... [more ▼]

The presentation will illustrate the efforts of the University of Liège in that new international trend: valorizing good teaching through : • portfolios, • training the teachers (certificates and degree granting), • helping faculty implement pedagogical innovations, • deploying a web portal with multiple tools serving autonomous improvement, notably in eLearning. Could some of those tools be shared, in a Charter perspective? [less ▲]

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See detailSpecies response to the fragmentation and restoration of wet heathlands and associated habitats in High Ardenne (Belgium) – A multi-taxonomic approach
Cristofoli, Sara ULg

Doctoral thesis (2009)

The impact of habitat fragmentation and the success of habitat restoration were studied through a multi-taxonomic approach. The response to landscape structure and/or habitat quality of three taxonomic ... [more ▼]

The impact of habitat fragmentation and the success of habitat restoration were studied through a multi-taxonomic approach. The response to landscape structure and/or habitat quality of three taxonomic groups was explored, in (semi-)natural habitats. The three taxonomic groups were complementary, both in terms of their specific life history traits and their place in the food chain. We considered autotrophic species (vascular plants), herbivores (butterflies) and predators (spiders). Life-history traits and species specialization for target habitat were used to refine the analysis. Target habitat was a complex of wet heathlands, poor fens and bogs. Patches of this complex of habitats were sampled on two high plateaus in the Belgian Ardenne, the Plateau de Saint-Hubert and the Plateau des Tailles. Over the last 250 years, two jointly acting habitat dynamics were observed in these areas: a loss of area (and connectivity) on the one hand but also the creation of new habitat patches. It is precisely this double dynamics that enabled us to analyze and develop concepts linked to the response of species faced with spatio-temporal modifications of their habitat. Specifically, in this work we focused on the comprehension of two unbalanced situations, affecting the relationships between species richness and patch characteristics. A first unbalanced situation, the extinction debt, was observed for vascular plant communities. On the opposite, a colonization credit, the second unbalanced situation, was noted for butterflies and seemed to mainly affect specialist species. Specialist species of the three taxonomic groups showed relatively contrasted responses compared to generalist species. However, the life-history traits we studied only slightly influenced the response of species at the community level, excepted for pioneer communities in habitat patches less than 5 years old. [less ▲]

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See detailPapel del CEDAPE en la Reforma Educativa del SEDUCA y su relación con la regulación del Sistema Educativo en Bélgica
Gilles, Jean-Luc ULg; Bruyninckx, Marielle; Aliss, Emilio

Scientific conference (2009, October 29)

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See detailValidation de méthodes analytiques: le profil d'exactitude
Heuskin, Stéphanie ULg

Scientific conference (2009, October 28)

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Peer Reviewed
See detailDelegation, externalities and organizational design
Gautier, Axel ULg; Paolini, Dimitri

in Economics Bulletin (2009), 29(4),

In a repeated interaction between a principal and two agents with inter-agents externalities and asymmetric information, we show that optimal decentralization within the organization is limited to the ... [more ▼]

In a repeated interaction between a principal and two agents with inter-agents externalities and asymmetric information, we show that optimal decentralization within the organization is limited to the first period and across agents. [less ▲]

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See detailMorphology and dynamics of the Io UV footprint
Bonfond, Bertrand ULg

Doctoral thesis (2009)

The Io UV footprint (IFP) is one of the most spectacular signatures of the Io-Jupiter interaction. It consists of several auroral spots and an extended tail which are located close to the feet of the ... [more ▼]

The Io UV footprint (IFP) is one of the most spectacular signatures of the Io-Jupiter interaction. It consists of several auroral spots and an extended tail which are located close to the feet of the magnetic field lines passing through Io in each hemisphere. The purpose of the present study is to demonstrate that a careful analysis of the Io UV footprint based on observations acquired with the STIS and ACS high resolution and high sensitivity FUV cameras on board the Hubble Space Telescope can provide us with essential information on the ongoing physical processes. The thesis is organized around basic questions: “What is the Io footprint?”, “Where is the Io footprint?”, “How high is the Io footprint?”, “How big is the Io footprint?” and finally: “How bright is the Io footprint?” The answers to these questions have profound implications for the understanding of the phenomenon. Among the most important results of this work is the unexpected finding of a faint auroral spot appearing upstream of the main Io spot in one hemisphere while only downstream spots are seen in the opposite hemisphere. The detailed study of the evolution of the inter-spot distances puts previous models describing the footprint morphology under question. We propose a new interpretation which involves that some spots are caused by electrons accelerated away from the planet along the field lines in one hemisphere, crossing the equatorial plane in the form of electron beams and precipitating in the opposite hemisphere, creating the so-called Trans-hemispheric Electron Beam (TEB) spots. The information provided by the position of the satellite footprints is not restricted to the interaction between the moon and the Jovian magnetosphere. The analysis of the footpaths of Io, Europa and Ganymede helped us to further constrain the magnetic field models, notably through the identification of a large magnetic anomaly in the northern hemisphere. Additionally, the study of the speed of the Io footprint along its reference contour suggests that a second anomaly regions may also exist in the North. In this work, we present a new and direct method to measure the altitude of the different footprint features. The main spot and the tail emissions have a peak altitude of 900 km while the peak altitude of the Trans-hemispheric Electron Beam spot is 700 km. These results suggest that the main spot and tail emissions are caused by the precipitation of electrons with a mean energy around 1 keV, far lower than the 55 keV value previously derived from spectral measurements. The vertical extent of these emissions is surprisingly broad (scale height ~400 km) and is best fitted with an incoming kappa electron energy distribution (spectral index ~2.3). This suggests that the electron acceleration is supplied by processes related to inertial Alfvén waves rather than by quasi-static potentials as proposed by some theoretical models. The size of the main footprint spot is carefully estimated on a much larger image sample than before: its length along the footpath is ~900 km while its width perpendicular to the footpath is <200 km. Larger lengths are sometimes observed but in that case, they are attributed to the mix of individual spots. The spot length is larger than the projected diameter of Io around the magnetic field lines but is consistent with recent simulations. As far as the Io footprint brightness is concerned, variations on two timescales have been studied. On timescales of minutes, systematic brightness fluctuation on the order of 30% (and going up to 50%) are observed. Additionally, cases of simultaneous variations of the main and the TEB spots are reported, which suggests that the process that triggers these fast variations is located close to the planet. Variations of the main spot brightness with the System III longitude of Io are also analyzed. Our new measurement method fully considering the multi-spot structure of the IFP and the real geometry of the observations provides more accurate estimates for the precipitating energy flux (between 100 and 500 mW/m for the main spot). The main spot brightness peaks at 110° and 290° longitude, which could be attributed either to an enhanced interaction strength when Io is near the dense torus center or to spots merging which is also observed to occur in these sector. Nevertheless, strong North-South asymmetries are also observed, which suggests that the surface magnetic field strength also influences the spots brightness. [less ▲]

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See detailCritères de reprise sportive après chirurgie tendineuse
Kaux, Jean-François ULg; Crielaard, Jean-Michel ULg

Conference (2009, October 26)

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See detailL'énurésie chez l'enfant: actualisation de la compréhension, l'évaluation et le traitement
Battisti, Oreste ULg

Scientific conference (2009, October 25)

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See detailApproche numérique simplifiée et comparaison aux résultats expérimentaux
Machiels, Olivier ULg

Conference (2009, October 23)

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See detailMéthode de pré-dimensionnement des PKW et application au barrage de la Raviège
Machiels, Olivier ULg

Conference (2009, October 23)

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See detailMarital satisfaction in couples with an alcoholic member
Dethier, Marie ULg; Counerotte, Christelle; Blairy, Sylvie ULg

Poster (2009, October 23)

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See detailLa démarche méthodologique et l'exploitation des données en recherche biomédicale
Rozet, Eric ULg

Scientific conference (2009, October 22)

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See detailEtude et modélisation des tendances en nitrate au sein de l’aquifère crayeux du bassin du Geer en support à la mise en œuvre de la directive cadre sur l’eau
Orban, Philippe ULg; Batlle-Aguilar, Jordi; Goderniaux, Pascal et al

Scientific conference (2009, October 22)

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Peer Reviewed
See detailDes bienfaits du libéralisme économique sur les salles obscures
Thirion, Nicolas ULg

in Recueil Dalloz (2009)

Commentaire d'un arrêt du Conseil d'Etat de France du 15 mai 2009 annulant un décret du Premier Ministre interdisant, au nom de la sécurité des consommateurs, la commercialisation de certains produits

Detailed reference viewed: 148 (46 ULg)