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See detailDétournements multi-supports d’une licence de jeu vidéo : le cas de Halo
Barnabé, Fanny ULg

Conference (2015, June 03)

Si les pratiques de détournement du jeu vidéo par les joueurs attirent depuis quelques années l’attention des chercheurs (voir Hellekson et Busse, 2006, concernant les fanfictions, ou Lowood et Nitsche ... [more ▼]

Si les pratiques de détournement du jeu vidéo par les joueurs attirent depuis quelques années l’attention des chercheurs (voir Hellekson et Busse, 2006, concernant les fanfictions, ou Lowood et Nitsche, 2011, concernant les machinimas, entre bien d’autres), et si leurs travaux ne cessent d’évoquer les interconnexions qui lient ces phénomènes, ces mêmes interconnexions restent encore peu problématisées. Bien qu’inscrite dans la continuité de ces premières recherches, la présente communication se propose donc d’envisager les détournements de jeux vidéo comme un seul et même objet afin de mesurer ce que les différentes pratiques de création amateur partagent, non dans leurs organisations propres, mais dans le rapport qu’elles entretiennent avec le jeu. Ce positionnement se nourrit, d’autre part, des diverses théories abordant le jeu sous l’optique du play (Henriot, 1969 ; Genvo, 2011 ; Triclot, 2011 ; etc.). Plutôt que de considérer le jeu comme la propriété d’un objet clos et fini, celles-ci le définissent comme une « expérience instrumentée » (Triclot, 2011 : 14) qui ne pourrait exister sans l’adoption préalable, par l’utilisateur, d’une « attitude ludique » (Henriot, 1969 : 73). Cette approche a l’avantage de ne pas cloisonner le concept de jeu à l’intérieur des dispositifs qui lui sont traditionnellement associés et de permettre l’appréhension de pratiques ludiques « périphériques », investissant des supports qui ne sont pas nécessairement « étiquetés » comme des jeux. L’écriture de fanfictions, la réalisation de machinimas, ou encore les performances ludiques détournées telles que le speedrun sont, par exemple, autant d’activités qui prennent naissance dans le contexte d’une activité de jeu mais qui débouchent sur la création d’œuvres non vidéoludiques (des textes et des vidéos). Or étudier ces pratiques de détournement du jeu vidéo à l’aune des théories du play permet de les envisager comme faisant partie intégrante de l’expérience ludique des joueurs et comme prolongeant le jeu (en tant que play) hors de son support initial (le game). Sur la base de ce cadre théorique, ce travail vise à interroger l’existence d’une continuité entre le jeu et les pratiques qui le détournent. Plus largement, nous tenterons de montrer en quoi les caractéristiques formelles des supports mobilisés viennent conditionner et modaliser l’expérience de jeu, sans toutefois la définir ni l’épuiser . Ces questionnements seront abordés à travers l’étude d’un cas de figure spécifique : les détournements des jeux de la licence Halo (Bungie Software, Microsoft Studios) sous forme de fanfictions , de machinimas et de speedruns . Ces trois pratiques de création amateur ont effectivement en commun le fait d’occasionner un changement de support : elles s’emparent d’un jeu vidéo ou de son univers pour produire des œuvres dérivées qui ne sont plus spontanément identifiées comme « ludiques ». Quelles sont donc les conséquences de ce passage du jeu au « document » (le texte, la vidéo) ? Les détournements conservent-ils des « marqueurs pragmatiques de jouabilité » (Genvo, 2011 : 76), des traces observables qui témoigneraient de leur inscription dans une « culture ludique » ? Dans quelle mesure le changement de support détermine-t-il, en retour, l’organisation de la pratique et les modalités de représentation de l’univers ? En d’autres termes : que reste-t-il du jeu Halo dans ces productions dérivées ? C’est à travers l’analyse des œuvres, mais aussi des discours qui leur servent de paratextes (présentations des fanfictions, machinimas et speedruns faites par leurs créateurs, commentaires des récepteurs) que nous tâcherons d’apporter un éclairage à ces questions. [less ▲]

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See detailConnecting planets to their moons: The auroral satellite footprints
Bonfond, Bertrand ULg

Conference (2015, June 03)

Among the many features of the Giant planets’ aurorae are very special spots which move in a very distinct manner compared with the remaining of the aurora. Indeed, these spots are magnetically connected ... [more ▼]

Among the many features of the Giant planets’ aurorae are very special spots which move in a very distinct manner compared with the remaining of the aurora. Indeed, these spots are magnetically connected with planetary satellites and rotate around the poles at the same pace as their parent moon. These features, called the satellite footprints, are the signature of the electromagnetic interaction between the moons and the rapidly rotating magnetosphere plasma. On Jupiter, Io, Europa and Ganymede (and possibly Callisto) have their respective footprints while only the Enceladus footprint has been detected on Saturn so far. Several models of the interaction between Io and the jovian magnetosphere, from the unipolar inductor to the ideal Alfvén wings model, have been proposed well before the first observations of the footprints in 1993. However, the continuously improving technologies and observing methods gave rise to more accurate observations that challenged several aspects of these models and lead to further refinements. For example, when analyzed in detail, high resolution images of the aurorae show that the footprints of Io and Ganymede are not made of one, but several spots, and that the footprint of Io, Europa and Ganymede can be followed by an extended tail. The respective motion of these spots as a function of the orientation of the planetary magnetic field suggests that the Alfvén waves launched from these satellites accelerate the electrons in both directions along the field lines, hence doubling the number of visible spots, Moreover, studies of the satellite footprints are not only useful to unveil some key aspects of the moon-magnetosphere interactions, but they also contribute to the understanding of the whole magnetospheric system. For instance, their locations have been used as landmarks to constrain magnetic field models or to more accurately relate some auroral structures with their root region in the magnetosphere. [less ▲]

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See detailLe jeu pour régénérer la ville?
Dethier, Perrine ULg; Halleux, Jean-Marie ULg

Conference (2015, June 03)

Notre travail de thèse porte sur la transférabilité des dispositifs de coopération entre acteurs en matière de régénération urbaine. Des innovations stratégiques, en particulier des outils de partenariats ... [more ▼]

Notre travail de thèse porte sur la transférabilité des dispositifs de coopération entre acteurs en matière de régénération urbaine. Des innovations stratégiques, en particulier des outils de partenariats privés-privés (remembrement urbain, business improvement district, Tax increment financing) se multiplient. Afin de rendre le transfert de ces outils un succès, il est nécessaire de prendre en compte les obstacles contextuels pour les adapter et les ajuster. L’étude de la culture d'aménagement (planning culture) est donc essentielle afin de déterminer les valeurs et les attitudes partagées par les acteurs de l’aménagement du territoire. Le sujet de la culture d’aménagement connait un intérêt croissant dans la littérature scientifique. Cependant, le terme reste peu clair et difficile à définir. La culture de planification pourrait être définie comme « les normes collectives et les attitudes dominantes des aménageurs aux regards des rôles assimilés à l’Etat, aux forces du marché et à la société civile influencés par les conditions sociales » . Pourtant, peu d’études empiriques sont réalisées. L’application de la théorie des jeux pourrait pallier ce manquement. Nous postulons que la théorie des jeux permettra de mettre en avant les différences culturelles d’aménagement afin d’adapter des stratégies innovantes pour être transféré avec succès en Wallonie. Notre analyse est basée sur une double approche : un état des lieux empirique sur les pratiques actuelles et les cultures d'aménagement et l’évaluation expérimentale du potentiel de ces approches par l’application de la théorie des jeux. « La théorie des jeux est la théorie mathématique des comportements stratégiques » . Elle étudie les interactions entre les joueurs (acteurs) et permet d’expliquer les prises de décisions. La théorie des jeux peut être appliquée en laboratoire dans le cadre de démarches expérimentales (économie expérimentale ). L’économie expérimentale permet de prendre en considération les aspects affectifs des acteurs dans la détermination de leur comportement. Elle ne considère pas les acteurs uniquement comme des agents rationnels. Notre intervention sera structurée en deux parties. La première synthétisera la littérature dédiée aux partenariats appliqués en matière de régénération urbaine et, en particulier, aux partenariats privés-privés. En seconde partie, nous définirons le terme de culture d’aménagement. En troisième partie, nous développerons une réflexion sur l’applicabilité de la théorie des jeux dans le domaine des partenariats liés à des opérations d’aménagement. Initiée en économie, la théorie des jeux s’est désormais étendue à de nombreuses autres disciplines (sociologie, sciences politiques, biologie…) mais elle reste peu utilisée dans le domaine de l’aménagement. Or, les interactions entre acteurs sont au cœur des opérations d’aménagement et, en particulier, des opérations de régénération urbaine. [less ▲]

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See detailAdolescentes délinquantes sexuelles : victimisation sexuelle et agression sexuelle, résonances et dissonances
Glowacz, Fabienne ULg

Conference (2015, June 03)

Peu d’études portant sur les adolescentes auteures d’une infraction à caractère sexuel sont menées à ce jour. De manière générale, la délinquance des filles a suscité un moindre intérêt et surtout a été ... [more ▼]

Peu d’études portant sur les adolescentes auteures d’une infraction à caractère sexuel sont menées à ce jour. De manière générale, la délinquance des filles a suscité un moindre intérêt et surtout a été entachée de mythes, de stéréotypes et de représentations qui ont entravé la levée du voile. Dans le champ de recherche sur l’agression sexuelle, la femme a été prioritairement associée au statut de victime, et il a longtemps été impensable que des adolescentes puissent commettre des violences sexuelles. Envisager la jeune fille comme auteure d’agression sexuelle a nécessité des avancées au niveau de la reconnaissance de la réalité des violences sexuelles perpétrées par les mineurs et de la délinquance sexuelle chez les femmes adultes (Tardif, Auclair, Jacob et Carpentier, 2005). Lane et Lobanov-Rostovsky (1997) estiment que les AAICS de sexe féminin constitueraient entre 5% et 8% de l’ensemble des AAICS. Il apparait donc que les filles sont plus souvent victimes d’abus sexuels que les garçons mais elles semblent moins nombreuses que les garçons à commettre des agressions sexuelles. Par ailleurs, les études en délinquance non sexuelle ont démontré que la victimisation sexuelle durant l’enfance est un facteur significativement associé au risque de conduites déviantes et de trajectoire délinquante durant l’adolescence, particulièrement pour les filles. Au niveau de l’âge adulte, il a été relevé des taux élevés d’antécédents de victimisation sexuelle (Goodkind, Ng et Sarri, 2006) : les femmes en détention présentent deux à trois fois plus d’antécédents de victimisation sexuelle durant leur enfance que les autres. L’abus sexuel apparait clairement pour les filles, plus que pour les garçons, comme un facteur de risque par rapport à l’adoption de conduites délinquantes durant l’adolescence. Des caractéristiques propres à l’abus sexuel peuvent augmenter le risque de délinquance et d’agirs violents, comme la durée et la chronicité de la période d’abus ainsi que le non-dévoilement des violences subies. Dans une de nos études, nous avons relevé que les adolescentes engagées dans la délinquance ayant été victimes d’abus sexuel sont plus nombreuses à présenter un PTSD que les adolescentes victimes non délinquantes, et surtout présentent davantage de symptômes d’évitement (Glowacz et Buzitu, 2014). La délinquance a dès lors été considérée comme une conduite d’évitement visant une mise à distance émotionnelle de la douleur associée à la victimisation sexuelle. Les conduites délinquantes apparaissent comme une forme de stratégie adaptative via une mise à distance du trauma, qui cependant entrave le processus de résilience. Bien que le taux de victimisation sexuelle dans la population des adolescentes délinquantes sexuelles soit variable selon les études, la victimisation est reconnue comme un des facteurs étiologiques de l’agression sexuelle. Wijkman, Bijleveld et Hendriks (2014) l’évaluent à 37% dans leur échantillon de jeunes délinquantes sexuelles alors que d’autres études arrivent à des taux plus élevés. Dans le cadre de la présente étude portant sur l’analyse de dossiers psycho-judiciaires, nous présenterons d’abord les profils des adolescentes délinquantes sexuelles et une ébauche de typologie. Nous nous intéresserons ensuite aux adolescentes AICS pour lesquelles il est signalé une victimisation sexuelle afin d’en identifier les spécificités mais surtout les résonances et les dissonances au niveau de l’abus sexuel subi et de l’abus sexuel commis. Les facteurs sociaux, familiaux, psycho-développementaux seront analysés à la lumière des dynamiques de transmission de l’abus sexuel subi par la perpétration d’agressions sexuelles. [less ▲]

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See detailReflections on tangs and other morphological adaptations that may be hafting-related
Tomasso, Sonja ULg; Taipale, Noora ULg

Conference (2015, June 03)

Tanged tools have always attracted archaeologists’ attention, and have often been considered to mark the beginnings of stone tool hafting. Very little is known, however, of the specifics of hafting these ... [more ▼]

Tanged tools have always attracted archaeologists’ attention, and have often been considered to mark the beginnings of stone tool hafting. Very little is known, however, of the specifics of hafting these tools. Also the role of tanged tools in toolkits and lithic assemblages, as well as their significance in terms of technological evolution and human behaviour, are still largely under debate. We are presenting here some of our first observations and ideas of hafting and use of tanged tools building on our ongoing PhD research on the Mousterian/Aterian cave site Ifri n’Ammar (Morocco) and the Gravettian open-air site Maisières-Canal (Belgium). Our experimental and analytical work aims at reconstructing plausible methods of hafting and using tanged tools, and contributing to a better understanding of the role of tangs in the assemblages under study. Our preliminary results suggest that several hafting modes are possible for tools of similar morphology, and that tanged and non-tanged tools can in some cases be hafted using the same logic. We therefore argue that more detailed functional data on both tanged and non-tanged tools is needed before we can meaningfully assess the importance of the presence of tanged tools in various archaeological contexts. [less ▲]

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See detailModélisation mathématique des risques d’inondation dans le bassin liégeois suivant différents scénarios de changements climatiques et d’aménagement du territoire
Dewals, Benjamin ULg; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

Conference (2015, June 03)

Dans une ancienne région minière, affectée par des affaissements significatifs de surface, la ville de Liège est actuellement efficacement protégée contre les crues par débordement de la Meuse grâce ... [more ▼]

Dans une ancienne région minière, affectée par des affaissements significatifs de surface, la ville de Liège est actuellement efficacement protégée contre les crues par débordement de la Meuse grâce essentiellement à une canalisation du fleuve. Une analyse prospective a été entamée, visant à évaluer la pérennité de la protection actuelle de la ville sous différents scénarios d’évolutions climatiques et d’aménagement du territoire. Prenant sa source en France et traversant la Belgique pour rejoindre son embouchure aux Pays-Bas, la Meuse ne peut être étudiée qu’en tenant compte de ce contexte transnational. C’est pourquoi, l’analyse prospective menée a été concertée à toutes les étapes non seulement avec les acteurs scientifiques et les gestionnaires de l’eau dans les régions limitrophes concernées, mais également avec des organisations représentatives de la société civile. En particulier, les scénarios climatiques retenus ainsi que les modélisations hydrauliques et hydro-économiques effectuées ont systématiquement été coordonnés, voire harmonisés, à l’échelle du bassin versant international du fleuve. Les résultats de l’analyse mettent en évidence un accroissement significatif de l’aléa inondation dans la ville de Liège à l’échéance de la fin du siècle. Ils permettent également de circonscrire le potentiel d’adaptation de la ville pour atténuer l’impact d’inondations, tant par des mesures techniques locales qu’à plus grande échelle. La portée de diverses politiques d’aménagement du territoire à Liège et au-delà a également pu être évaluée et l’analyse révèle un degré d’efficacité très contrasté selon les communes concernées. [less ▲]

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See detailLa création de jeux vidéo en amateur : la place du forum
Hurel, Pierre-Yves ULg

Conference (2015, June 03)

Notre communication interroge la pertinence d'aborder le forum comme une plateforme technique et sociale de l'appropriation du jeu vidéo. Nous nous sommes appuyés notamment sur une première série de cinq ... [more ▼]

Notre communication interroge la pertinence d'aborder le forum comme une plateforme technique et sociale de l'appropriation du jeu vidéo. Nous nous sommes appuyés notamment sur une première série de cinq entretiens exploratoires d'amateurs fortement impliqués dans des communautés en ligne afin de déterminer le sens qu'ils donnent à leur pratique, à leur présence et aux échanges sur ces forums. [less ▲]

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See detail« Prof d’EPS » un métier qui bouge
Cloes, Marc ULg

Conference (2015, June 03)

Since the beginning of the 3rd millenium, the focus of the physical educaiton course evolved a lot, as well as the expected role of the teachers. In fact, the priority given to the teaching of sport ... [more ▼]

Since the beginning of the 3rd millenium, the focus of the physical educaiton course evolved a lot, as well as the expected role of the teachers. In fact, the priority given to the teaching of sport skills progressively moved to the preparation of physically educated citizen. In parallel, School being considered as one of the main pilar of the fight against sedentariness and promotion of an active lifestyle, PE teachers are more and more presented as the responsables of the coordination of such actions within their schools. It means that they have to envisage to adapt their representations and professional decisions. The goal of this presentation is to stimulate the awareness and to illustrate courses of action likely to incitate pratitioners to engage themselves in a reviewing process. [less ▲]

Detailed reference viewed: 103 (10 ULg)
See detailAliphatic polyphosphates, a promising class of polymers for drug delivery
Vanslambrouck, Stéphanie ULg; Clément, Benoit; Molin, Daniel G. et al

Conference (2015, June 02)

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See detailAuroral emission at Jupiter, through Juno's UVS eyes
Grodent, Denis ULg; Bonfond, Bertrand ULg; Gladstone, G. et al

Conference (2015, June 02)

Juno’s orbit insertion around Jupiter will take place in little bit more than one year (July 2016). After a 107-day capture orbit (Oct. 2016), it will perform a series of 33 eleven-day science polar ... [more ▼]

Juno’s orbit insertion around Jupiter will take place in little bit more than one year (July 2016). After a 107-day capture orbit (Oct. 2016), it will perform a series of 33 eleven-day science polar orbits offering unprecedented views of the auroral regions of Jupiter. The science payload of Juno includes an UltraViolet Spectrograph (UVS) that will characterize the UV auroral emissions of Jupiter over all science orbits. It will obtain high-resolution images and spectra that will provide context for Juno’s in situ particles and fields measurements in the larger polar magnetosphere with Juno’s JADE and JEDI detectors. At the same time, the MAG instrument will accurately constrain magnetic field models, which will provide the connection between Juno and its field line footprint in the Jovian aurora. The UVS instrument consists of a solar blind MCP detector with a “dog-bone” shape FOV of 0.2°x2.5°+0.025°x2°+0.2°x2.5° providing a spatial resolution of 125 km from 1RJ above the aurora and a spectral resolution of ~0.5 nm (~2 nm for extended sources). It is sensitive to EUV-FUV radiation ranging from 70 nm to 205 nm. Juno is a spin-stabilized spacecraft and is rotating at a frequency of 2 RPM. UVS will take advantage of this motion to scan the auroral regions in the direction perpendicular to the slit, while its steerable pickup mirror (±30° from the spin plane) will make it possible to point at specific regions of the aurora. Juno’s highly eccentric science orbits have a perijove close to 1.05 RJ (~5000 km above cloud deck) and an apojove at ~38 RJ. These orbits approximately lie in the Dawn meridian plane and are such that each successive pass is at a Jovian longitude displaced by 204° from the previous perijove. At perijove, Juno’s velocity will be ~60 km/s and about 20 km/s above the poles, meaning that the spacecraft will move over the northern and southern auroral regions in approximately two hours. In this study, we are using existing HST STIS time-tag sequences of Jupiter’s UV aurorae in order to simulate the expected measurements through UVS FOV along Juno’s predicted trajectory. The simulations account for realistic instrumental specifications and pointing and for the temporal and spatial variability of the aurora. We show the results of image reconstruction obtained from scanning the auroral region with UVS slit and provide some limits on the expected data quality as a function of the location of Juno along its orbit. We also suggest portions of the science orbits for which supporting HST observations will be necessary. [less ▲]

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See detailL'image dans le concours EUROPAN : étude de l'évolution de la représentation graphique du projet
Boutemadja, Abdelkader ULg; Reiter, Sigrid ULg

Conference (2015, June 02)

EUROPAN se distingue par sa volonté de mettre en avant de jeunes architectes mais aussi « d’approfondir les connaissances et les réflexions dans le domaine de l’habitat et de l’urbanisme ». Le fait que le ... [more ▼]

EUROPAN se distingue par sa volonté de mettre en avant de jeunes architectes mais aussi « d’approfondir les connaissances et les réflexions dans le domaine de l’habitat et de l’urbanisme ». Le fait que le projet lauréat a pour visée d’être traduit en une commande et une réalisation concrète permet d’attirer des projets réalistes dont la finalité est de s’inscrire dans un processus décisionnel complexe et complet. En outre, signalons que les auteurs de projets y présentent leur idées presqu’exclusivement au travers de la représentation graphique dont le support est le même pour tous (3 planches A1) et que ce concours a fait l’objet d’un archivage important. Ainsi, ce champ d’expérimentation nous permet d’analyser l’évolution durant les dernières décennies des modes de représentation graphique du projet dans le cadre du concours d’idées architecturales et urbaines. L’analyse des documents graphiques retenus dans ce champ d’expérimentation nous a permis de relever les différentes typologies graphiques utilisées dans leur composition. Il s’agit de : chorèmes, de schémas, de plans/coupes/élévations, d’images 3D et de textes. Ces différentes typologies se déclinent en sous-entités suivant les relations que les unes établissent avec les autres (par exemple : des schémas en 3D ou des images 3D intégrant des coupes …). Grâce à une analyse comparative du nombre de types utilisés et des surfaces dédiées à chacun d’eux au cours des différentes sessions, nous avons constaté un usage assez constant des chorèmes et des schémas mais une évolution de l’utilisation des images 3D par rapport aux plans/coupes/élévations donnant de plus en plus d’importance aux images 3D au détriment de documents graphiques plus conventionnels avec même parfois des transferts de charges symboliques d’un type à l’autre. Cette recherche montre ainsi que l’image 3D est désormais intégrée comme l’un des moyens les plus importants de communication et de partage d’informations concernant le projet urbain. Enfin, cette recherche révèle l’intérêt pour notre discipline de développer une méthode spécifique de lecture de la représentation graphique du projet architectural et urbain, de manière à étudier l’image non seulement comme support de représentation mais aussi en tant que système de communication. La méthode de lecture des images proposée est fondée sur l’utilisation et l’adaptation de méthodes et techniques d’interprétations de projets et d’images développées initialement dans les domaines de la systémique et de la sémiotique ; elle pourra être utilisée dans des recherches ultérieures pour continuer d’améliorer notre compréhension de l’évolution des représentations graphiques du projet. [less ▲]

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See detailHubble spectral observations of the Jovian aurora: precipitated flux and electron mean energy
Gérard, Jean-Claude ULg; Bonfond, Bertrand ULg; Grodent, Denis ULg et al

Conference (2015, June 02)

The FUV Jovian aurora is excited by collisions of energetic electrons accelerated along the magnetic field lines with the ambient upper atmosphere. The emission is dominated by the H2 Lyman and Werner ... [more ▼]

The FUV Jovian aurora is excited by collisions of energetic electrons accelerated along the magnetic field lines with the ambient upper atmosphere. The emission is dominated by the H2 Lyman and Werner bands extending from the extreme ultraviolet to about 170 nm. The wavelengths below about 135 nm are partly absorbed by the methane layer overlying the auroral emission layer. The long wavelength intensity is proportional to the precipitated energy flux carried by the auroral electrons. Spectral observations with the Hubble Space Telescope were made in 2014 using the long slit of the Space Telescope Imaging Spectrograph (STIS) in the timetag mode. During these observations, the slit projection scanned the polar region down to mid-latitudes. The combination of spectral and temporal measurements was used to build up the first spectral maps of the FUV Jovian aurora. The two-dimensional distribution of the intensity ratio of the two spectral regions has been obtained by combining spectral emissions in these wavelength ranges. They show that the amount of absorption by methane varies significantly between the different components of the aurora and in the polar region. Outputs from an electron transport model are used to create maps of the distribution of the characteristic electron energies. Using model atmospheres adapted to auroral conditions, we conclude that electron energies generally range between a few tens to several hundred keV. In this presentation, we analyze the relationship between the precipitated electron energy flux and the mean electron energy derived from these observations. Although globally, no correlation can be found, we show that the two quantities co-vary in some auroral components such as in the morning sector or in the striations observed along the main emission. By contrast, the auroral input in some high-latitude regions show no correlation with the electron characteristic energy. These aspects will be quantitatively discussed and possible processes explaining this dichotomy will be proposed. Comparisons of derived energies are in general agreement with those calculated from magnetosphere-ionosphere coupling models, but they locally exceed current model predictions. These results provide a basis for three-dimensional modeling of the distribution of particle heat sources into the high-latitude Jovian upper atmosphere. [less ▲]

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See detailThe systematic price of credit risk
François, Pascal; Heck, Stéphanie ULg; Hübner, Georges ULg et al

Conference (2015, June 01)

Using corporate bond index series over a period of 16 years, we provide a detailed decomposition of a bond’s expected returns. We are able to distinguish between the pre- mium related to systematic ... [more ▼]

Using corporate bond index series over a period of 16 years, we provide a detailed decomposition of a bond’s expected returns. We are able to distinguish between the pre- mium related to systematic default risk and the premium related to the default event. We further analyze the determinants of expected returns and of the identified risk premiums, using variables constructed from credit markets, from stock markets and from moment related risk. The variables successfully explain a large part of the variations in those two premiums, however the signs on the variables are exactly opposed in the explanation of the systematic default risk premium and the default event premium. [less ▲]

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See detailMulti-period vehicle assignment problem with stochastic transportation order availability
Pironet, Thierry ULg; Crama, Yves ULg

Conference (2015, June 01)

This work investigates optimization techniques for a vehicle-load assignment problem. A company owning a limited fleet of vehicles wants to maximize its operational profit over an infinite horizon divided ... [more ▼]

This work investigates optimization techniques for a vehicle-load assignment problem. A company owning a limited fleet of vehicles wants to maximize its operational profit over an infinite horizon divided into periods. The profit stems from revenues for transporting full truckloads and costs derived from waiting idle and moving unladen. The stochastic component of the problem arises from projections on the realization of each transportation order, i.e. load. The methodology is based on optimizing decisions for deterministic scenarios. Several policies are generated in this way, from simple heuristics to more complex approaches, such as consensus and restricted expectation algorithms, up to policies derived from network flow models formulated over subtrees of scenarios. Myopic and a-posteriori deterministic optimizations models are used to compute bounds allowing for performance evaluation. Tests are performed on various instances featuring different number of loads, graph sizes, sparsity, and probability distributions. Performances are compared statistically over paired samples. The robustness of various policies with respect to erroneous évaluations of the probability distributions is also analyzed. [less ▲]

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See detailNorovirus: ce que les praticiens de soins devraient savoir.
HUYNEN, Pascale ULg

Conference (2015, June 01)

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See detailMechanical approach for the characterization of loess deposits from the CBR’s Romont quarry (Eben-Emael, Belgium) and correlations with loess stratigraphy
Delvoie, Simon ULg; Boulvain, Frédéric ULg; Cerfontaine, Benjamin ULg et al

Conference (2015, June 01)

Aeolian silts (loess) are near surface deposits covering about 10% of the continent surfaces . Therefore a good knowledge of their mechanical behavior is an issue for designing subsurface engineering ... [more ▼]

Aeolian silts (loess) are near surface deposits covering about 10% of the continent surfaces . Therefore a good knowledge of their mechanical behavior is an issue for designing subsurface engineering structures. Usually this material is considered as homogeneous for an engineering point of view. Aeolian silt deposits are continuously well developed in Hesbaye Region (Belgium) reaching locally 20m thick (see document in attachment). They are mainly related to the last interglacial (Eemian) and glacial (Weichselian) periods . Nevertheless the pedostratigraphical, chronostratigraphical and paleoclimatic approaches have shown these silt deposits are usually composed of a series of paleosoils (i.e. Rocourt soil, Humiferous Complex of Remicourt, Harmignies Soil, Nagelbeek Tongued Horizon) interbedded with stratified or homogeneous aeolian silt layers. This study aims to characterize the variability of the in situ mechanical characteristics of the loess deposits from Hesbaye Region at the site scale and at the laboratory scale. Cone penetration tests (CPT), electrical resistivity tomographies (ERT) and drillings have been performed through a 10m thick loess layer in an investigation site located close to the CBR’s Romont quarry (Eben-Emael, Belgium) . Continuous undisturbed silt samples from drillings have been physically (granulometry, Atterberg limits, water content, organic matter content, carbonate content) and mechanically (oedometer test, triaxial test) characterized at the laboratory. Mechanical behavior and physical characteristics have underlined a series of layers with variable mechanical properties through depth. Some of these layers correlated with a detailed stratigraphy cross-section close to the investigation site could correspond to well-known paleosoils. [less ▲]

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Peer Reviewed
See detailOccupational physicians managing workers long-term sickness absence : are they willing to cooperate with family and social insurance physicians ?
Mairiaux, Philippe ULg; Vanmeerbeek, Marc ULg; Schippers, Nathalie ULg et al

Conference (2015, June)

Introduction In Belgium, sickness absence (SA) management implies complementary roles for family (FPs), social insurance (SIPs) and occupational physicians (OPs): FPs deliver sick notes, SIPs control SA ... [more ▼]

Introduction In Belgium, sickness absence (SA) management implies complementary roles for family (FPs), social insurance (SIPs) and occupational physicians (OPs): FPs deliver sick notes, SIPs control SA benefits and OPs strive to adapt work environments to workers’ capacities. In practice however, there is little cooperation between the three physicians. This study aimed at identifying FP-OP-SIP cooperation channels in order to prevent long-term work disability. Methods The study involved two phases. (1) Using the nominal group technique, researchers from the three physician groups reached a consensus on 15 proposals to enhance inter-professional cooperation. (2) A Delphi study was conducted to validate these proposals: 61 experts representing professional groups of physicians (FP, SIP, OP), patients, government, employers and labor unions were asked to participate. A 18-items questionnaire (the 15 proposals + 3 open questions) was used in a 2-round Delphi study. Proposals were accepted if 80% of experts agreed. Results Participation rate was 77% in round 1 and 7 out of the 15 proposals were accepted. During round 2, participation rate was 94%; 2 of the remaining proposals reached agreement level. Public authorities were thus advised to invest in a) promotion of pre-return to work visit with the OP for sick-listed patients; b) a website with OPs contact data; c) joint guidelines for return to work guidance; d) joint training of the 3 physician groups; 5) safe electronic information exchange. Several proposals aiming at giving work-related information to FPs and SIPs did not reach agreement within the OPs expert group. OPs expressed concerns about their own workload and FPs or SIPs ability to understand and use those information. Discussion The need for inter-physician cooperation in disability management may exceed individual goodwill and should best be organised by public authorities. This study may be a first step in this process. [less ▲]

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See detailGenetic depletion of the dual specificity protein phosphatase DUSP3 promotes LLC Lung tumour metastasis
Vandereyken, Maud ULg; Amand, Mathieu ULg; Van Overmeire, Eva et al

Conference (2015, June)

DUSP3, also called Vaccinia-H1 Related (VHR) is a small dual specificity phosphatase dephosphorylating both tyrosine and serine/threonine phosphorylated residues. DUSP3 plays an important role in cell ... [more ▼]

DUSP3, also called Vaccinia-H1 Related (VHR) is a small dual specificity phosphatase dephosphorylating both tyrosine and serine/threonine phosphorylated residues. DUSP3 plays an important role in cell cycle regulation and is up-regulated in several human cancers. The physiological role of this phosphatase is, however, poorly understood. We have recently generated a DUSP3 knockout mouse by homologous recombination. The obtained mice have no spontaneous phenotype or pathology. However, DUSP3 deficiency prevented neo-vascularization of subcutaneously transplanted Matrigel plugs and Lung Lewis Carcinoma (LLC) tumours, suggesting an involvement of DUSP3 in tumour angiogenesis. Considering the importance of angiogenesis in metastatic formation, our study aimed to investigate the role of DUSP3 in metastatic dissemination. To do so, we used the LLC experimental metastasis model that shortcuts the intravasation/extravasation processes by injecting intravenously the LLC and the B16 (metastatic melanoma cell line) cells. Surprisingly, LLC, but not B16, lung metastasis developed twice faster in DUSP3-KO than WT mice. The enhanced LLC metastatic growth in DUSP3-/- mice was transferable to WT mice via DUSP3-/- bone marrow adoptive transfer, suggesting an involvement of the hematopoietic compartment in the observed phenotype. This was confirmed by a higher infiltration of neutrophils and macrophages in the lungs of DUSP3-KO compared to WT mice after LLC injection. This infiltration was correlated with higher expression of the chemokine receptor CCR2 in LLC-bearing DUSP3-KO lungs macrophages. Interestingly, LLC, but not B16 cells, were found to secrete high level of CCL2/MCP1, the CCR ligand chemokine. In line with this observation, we found that DUSP3-/- bone marrow derived-macrophages have a higher migration potential in response to LLC, but not B16, -conditionned medium. Altogether, our results suggest that DUSP3 plays an important role in metastatic dissemination/growth by a mechanism involving the control of CCR2-CCL2 chemoattraction axis in macrophages. [less ▲]

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See detailBesoins lipidiques du patient brûlé.
ROUSSEAU, Anne-Françoise ULg

Conference (2015, June)

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See detailSmall-Angle Scattering in Porous Solids, an overview highlighting data analysis challenges
Gommes, Cédric ULg

Conference (2015, June)

Countless technologies and chemical processes make use of nanoporous materials: heterogeneous catalysis, including electrochemical reactions in fuel-cell electrodes, adsorption separation processes ... [more ▼]

Countless technologies and chemical processes make use of nanoporous materials: heterogeneous catalysis, including electrochemical reactions in fuel-cell electrodes, adsorption separation processes, kinetically selective membrane processes, are but a few examples. Nanopores are also relevant to natural processes as diverse as the weathering of rocks and ion transport through biological membranes.[1] Small-angle scattering of x-rays (SAXS) or neutrons (SANS) is one of the few experimental methods currently available for the in situ analysis of phenomena in this type of materials at the mesoscopic scale.[e.g. 2,3] In this presentation, we briefly review some recent applications of small-angle scattering to the in situ analysis of phenomena inside mesoporous solids. A particular focus is put on the data analysis challenges, whereby the scattered intensity is converted to real-space structures with nanometer resolution. [less ▲]

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See detailThe Social (Re)construction of an Incident Reporting System: Opening-up, Closing-down, Starting over
Rossignol, Nicolas ULg

Conference (2015, June)

The literature on incident reporting generally describes Incident Reporting Systems (IRS) as technological tools aiming at improving safety in organizations by initiating a learning process from previous ... [more ▼]

The literature on incident reporting generally describes Incident Reporting Systems (IRS) as technological tools aiming at improving safety in organizations by initiating a learning process from previous events, in order to prevent future incidents and accidents to occur. In this respect, many studies tend to focus on “barriers to reporting” in order to understand why people report (or not) incidents in the dedicated system. Alternatively, we proposed to study IRS as socio-technical artifacts which are embedded in a specific organizational culture and which are interpreted in different ways, illustrating what has been called “interpretive flexibility”. This communication is divided in two parts. First, relying on the Social Construction Of Technology (SCOT) framework, we present the different practices and meanings attributed to the reporting of incidents within the Belgian Nuclear Research Center (SCK•CEN). We link these to the various modes of learning that they enable. By doing so we participate to the opening-up of the research on Incident Reporting to alternative discourses, practices and meanings, unforeseen situations and uncertainties. Second, we present the preliminary results of creative workshops during which we initiated the participatory re-construction of the IRS within the Center, drawing on and extending the results of the “opening-up” phase. By doing so, we aim at contributing to a transparent realization of the reduction of complexity leading to an informed and collective decision on what could/should be the IRS of the Center. In conclusion, we propose a reflexive analysis of this process, and we formulate tentative future research directions. [less ▲]

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See detailStratégies d’émergence et rire de groupe : les Hydropathes
Saint-Amand, Denis ULg

Conference (2015, June)

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See detailA frequency-domain method for identifying nonlinear vibrating structures
Noël, Jean-Philippe ULg; Dossogne, Tilàn ULg; Kerschen, Gaëtan ULg

Conference (2015, June)

System identification, which refers to the construction of mathematical models from experimental data, plays a key role in the design process of engineering systems. In structural dynamics, the ... [more ▼]

System identification, which refers to the construction of mathematical models from experimental data, plays a key role in the design process of engineering systems. In structural dynamics, the theoretical and experimental aspects of linear system identification have been successfully addressed since the early seventies, and mature analytical, computational and testing tools have emerged. Nonlinear system identification of vibrating structures has also enjoyed significant advances during the past few years. However, the common practice in industry is to ignore nonlinearities, arguably because their analysis is still regarded as impractical. The present work describes a rigorous nonlinear generalisation in the frequency domain of the classical subspace identification algorithms, termed FNSI method. This method is applicable to large-scale systems comprising strong nonlinearities, closely-spaced modes and potentially high, nonproportional damping. Another distinct advantage of the approach is that it offers a convenient way to select an appropriate order for the nonlinear model by means of stabilisation diagrams. The FNSI method is demonstrated in this study using a complete satellite structure with nonsmooth nonlinearities, and a solar panel assembly exhibiting complex nonlinear stiffness and damping mechanisms. [less ▲]

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See detailCircadian and sleep homeostatic regulation of cerebral correlates of working memory: time of day matters
Reichert, Carolin; Maire, Micheline; Gabel, Virginie et al

Conference (2015, June)

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See detailNonlinear model updating by means of identified nonlinear normal modes
Song, Mingming; Renson, Ludovic ULg; Noël, Jean-Philippe ULg et al

Conference (2015, June)

Modal parameters are the most common features used for linear model updating. Although the modal analysis theory does not hold for nonlinear dynamic systems, its popularity encouraged researchers to come ... [more ▼]

Modal parameters are the most common features used for linear model updating. Although the modal analysis theory does not hold for nonlinear dynamic systems, its popularity encouraged researchers to come up with an equivalent version of normal modes for nonlinear systems, i.e., nonlinear normal modes (NNMs). A nonlinear system vibrates in NNMs when all masses have periodic motions of the same period, and at any time, the position of all the masses is uniquely defined by the position of any one of them. This paper investigates the feasibility of nonlinear model updating by minimizing the difference between the model-predicted and measured/identified nonlinear normal modes. A two degree-of-freedom mass-spring system with three linear springs and a cubic nonlinear spring is considered as the case study. The energy-dependent natural frequency and NNM of the first vibration mode of the system are identified at three different levels of energy. The stiffness parameters of the system are estimated by minimizing an objective function which is defined as the discrepancy between model-predicted natural frequency and NNM of the first mode, and their identified counterparts at the three measured energy levels. Performance of the proposed updating approach is evaluated at different levels of noise and different levels of modeling errors (i.e., nonlinear model classes). [less ▲]

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See detailA forecasting method using a wavelet-based mode decomposition and application to the ENSO index
Deliège, Adrien ULg; Nicolay, Samuel ULg; Fettweis, Xavier ULg

Conference (2015, June)

This work consists of a presentation and applications of a forecasting methodology based on a mode decomposition performed through a continuous wavelet transform. The idea is comparable to the Fourier ... [more ▼]

This work consists of a presentation and applications of a forecasting methodology based on a mode decomposition performed through a continuous wavelet transform. The idea is comparable to the Fourier series decomposition but where the amplitudes of the components are not constant anymore: the signal is written as a sum of periodic components with smooth time-varying amplitudes. This leads to a drastic decrease in the number of terms needed to decompose and rebuild the original signal without loss of precision. Once the decomposition is performed, the components are separately extrapolated, which leads to an extrapolation of the reconstructed signal that stands for a forecast of the original one. The quality of the forecast is assessed through a hindcast procedure (running retroactive probing forecasts) and Pearson correlations and root mean square errors are computed as functions of the lead time. This technique is first illustrated in details with a toy example, then with the El Niño Southern Oscillation (ENSO) time series. This signal consists of monthly-sampled sea surface temperature (SST) anomalies in the Eastern Pacific Ocean and is well-known to be one of the most influential climate patterns on the planet, inducing many consequences worldwide (hurricanes, droughts, flooding,…) and affecting human activities. Therefore, short-term predictions are of first importance in order to plan actions before the occurrence of these phenomena. As far as the ENSO time series is concerned, the wavelet-based mode decomposition leads to four components corresponding to periods of about 20, 31, 43 and 61 months respectively and the reconstruction recovers 97% of the El Niño/La Niña events (anomalous warming/cooling of the SST) of the last 65 years. Also, it turns out that more than 78% of these extreme events can be retrieved up to three years in advance. Finally, a forecast of the ENSO index is issued: the next La Niña event should start early in 2018 and should be followed soon after by a strong El Niño event in the second semester of 2019. [less ▲]

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See detailMeasuring the size of the broad line region in quasars with Microlensing-aided reverberation mapping
Sluse, Dominique ULg; Tewes, Malte

Conference (2015, June)

Owing to the advent of large area photometric surveys, the possibility to use broad band photometric data, instead of spectra, to measure the size of the broad line region of active galactic nuclei, has ... [more ▼]

Owing to the advent of large area photometric surveys, the possibility to use broad band photometric data, instead of spectra, to measure the size of the broad line region of active galactic nuclei, has raised a large interest. We will describe a new method using time-delay lensed quasars where one (or several) images are affected by microlensing due to stars in the lensing galaxy. Because microlensing decreases (or increases) the flux of the continuum compared to the broad line region, it changes the contrast between these two emission components. We show that this effect can be used to effectively disentangle the intrinsic variability of those two regions, offering the opportunity to perform reverberation mapping based on single band photometric data. Based on simulated light curves, we show that measurement of the size of the broad line region can be achieved using this method, provided one spectrum has been obtained independently during the monitoring. This method is complementary to photometric reverberation mapping and could also be extended to multi-band data. [less ▲]

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See detailModeling inflorescence development in tomato
Périlleux, Claire ULg; Lobet, Guillaume ULg; Tocquin, Pierre ULg

Conference (2015, June)

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See detailThe central role of the thymus in the programming of immunological tolerance to neuroendocrine self: Implications for the pathogenesis of autoimmune diseases.

Geenen, Vincent ULg

Conference (2015, June)

Our studies have demonstrated that the thymus programs central self-tolerance to neuroendocrine functions through transcription of neuroendocrine-related genes in thymic epithelial cells (TECs). However ... [more ▼]

Our studies have demonstrated that the thymus programs central self-tolerance to neuroendocrine functions through transcription of neuroendocrine-related genes in thymic epithelial cells (TECs). However, thymic neuroendocrine precursors are not secreted but processed as the source of neuroendocrine self-antigens that are presented by thymic proteins of the major histocompatibility complex (MHC). This process, highly specific of the thymus, has allowed an integrated and harmonious coevolution of the neuroendocrine and immune systems when recombination-activating genes and the subsequent adaptive immune response have emerged in cartilaginous fishes some 450-500 millions years ago. All the members of the insulin gene family are expressed in murine TECs under the control of AutoImmune Regulator (AIRE) according a precise hierarchy: Igf2 >Igf1>Ins2>Ins1. Igf2 transcription is defective in TECs of autoimmune diabetes-prone BB rats, and tolerance to insulin is severely impaired in Igf2-/- mice as well as in Igf2-loxP/Foxn1-cre mice with Igf2 deletion targeted in TECs. In addition, the diabetogenic coxsackievirus B4 (CV-B4) is able to persistently infect human and murine TECs and to inhibit Igf2 transcription and IGF-2 synthesis in a murine medullary TEC line (coolaboration with D. Hober, Laboratory of Virology, CHRU and University of Lille 2, France). These studies show that: 1° IGF-2 is the dominant tolerogenic precursor of the family and mediates cross-tolerance to insulin; 2° a thymus dysfunction plays a crucial role in the development of the diabetogenic autoimmune response; and 3° a thymic infection by CV-B4 is implicated in type 1 diabetes (T1D) pathogenesis. Most probably due to its very low level of expression in the thymus, the protein insulin is highly immunogenic and is the primary autoantigen tackled in T1D. On the basis of the tolerogenic properties of IGF-2, we are currently working on the development of a negative/tolerogenic self-vaccine against T1D. [less ▲]

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See detailFavoriser l'émergence d'innovations institutionnelles dans la gouvernance des universités du Moyen-Orient: retour sur notre rôle de chercheur-intervenant dans un projet de collaboration internationale
Lisein, Olivier ULg; Pichault, François ULg

Conference (2015, June)

Cette communication revient sur un projet de recherche-action – visant à mettre en œuvre de nouveaux modes de gouvernance au sein de cinq universités d’Afrique méditerranéenne et du Moyen-Orient – que ... [more ▼]

Cette communication revient sur un projet de recherche-action – visant à mettre en œuvre de nouveaux modes de gouvernance au sein de cinq universités d’Afrique méditerranéenne et du Moyen-Orient – que nous avons géré pendant trois ans. A partir des enseignements que nous avons retirés de nos responsabilités dans ce projet collaboratif, nous proposons un regard réflexif sur notre position et notre rôle de chercheurs-intervenants invités à gérer un projet de recherche-action dans des contextes culturels auxquels nous n’étions pas habitués, avec des méthodologies implicatives pas nécessairement partagées par toutes les parties. Nous élaborons sur cette base différentes pistes d’explication potentielle aux difficultés méthodologiques que nous avons rencontrées et aux résultats contrastés que nous avons atteints. [less ▲]

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See detailAdjusted Equivalent Static Wind Loads for non-Gaussian linear static analysis
Blaise, Nicolas ULg; Denoël, Vincent ULg

Conference (2015, June)

In this paper, we propose a parametric bi-cubic model for the joint probability distribution of wind aerodynamic pressures and structural responses. This non-Gaussian model is a bivariate extension of the ... [more ▼]

In this paper, we propose a parametric bi-cubic model for the joint probability distribution of wind aerodynamic pressures and structural responses. This non-Gaussian model is a bivariate extension of the well-known Hermite polynomial transformation. It offers a new way to determine Equivalent Static Wind Loads, with the embedded feature to –at least partly– capture the non-Gaussianity of the aerodynamic pressures and responses. In a second step, based on the observation that this model as well as the usual LRC method or the conditional sampling technique, fail in reproducing structural responses that do not overestimate the extreme values resulting from a complete structural analysis, we propose a two-step adjustment procedure that restores the non-overestimation condition and the recovery of the considered structural response. With the example of a boundary layer flow around a duo-pitched roof, it is demonstrated that the Equivalent Static Wind Loads, adjusted or not, obtained with the proposed model of non-Gaussian joint probability density function reconstruct the envelope of structural response more efficiently than with the other two techniques. [less ▲]

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See detailHydrodynamics, mixing and mass transfer in baffled stirred tanks
de Lamotte, Anne ULg; Delafosse, Angélique ULg; Calvo, Sébastien ULg et al

Conference (2015, June)

The present work presents CFD simulations of hydrodynamics, mixing and mass transfer in a surface-aerated baffled stirred tank. The modelling of the multiphase flow is realized via an Euler-Euler approach ... [more ▼]

The present work presents CFD simulations of hydrodynamics, mixing and mass transfer in a surface-aerated baffled stirred tank. The modelling of the multiphase flow is realized via an Euler-Euler approach. Three closure models are tested for the resolution of the RANS equations. When fully-developed flow field is reached, gas-liquid transfer is implemented with a local mass transfer coefficient estimated by the eddy cell model, and the temporal evolution of dissolved gas concentration is predicted.Hydrodynamic and mixing quantities as well as mass transfer parameters for the different turbulence models are compared with experimental data available for the same geometrical and operating features. A critical analysis of the prediction results allow to assess the models capabilities and to highlight the possible critical issues of the simulations. [less ▲]

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See detailQuantifying drought effects on groundwater recharge in a human-influenced catchment
Verbeiren, Boud; Huysmans, Marijke; Vanderhaegen, Sven et al

Conference (2015, June)

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See detailLinking political discourses on science with an evolving and densely populated context: Exploring the prospects of Cultural Political Economy
Charlier, Nathan ULg

Conference (2015, June)

As a PhD student, I investigate the multiple ways science is conceived and valued in a research and innovation (R&I) policy context under seismic shifts (Tyfield, 2012): I aim at analyzing and comparing ... [more ▼]

As a PhD student, I investigate the multiple ways science is conceived and valued in a research and innovation (R&I) policy context under seismic shifts (Tyfield, 2012): I aim at analyzing and comparing the various political discourses about R&I in Flanders and Wallonia (the two main regions of Federal Belgium). With regards to that goal, I am currently in the process of analyzing a corpus of 33 semi-structured interviews with principal investigators of two University biotech research centers, with members of two University research management boards, and with representatives of two regional science policy advisory boards. In order to analyze this particular set of discourses, I build on various sensitizing concepts (van den Hoonard 1997) such as policy narratives (Radaelli, 2000), while following the tenets of Grounded Theory (Glaser & Strauss, 1967). However, it is, I believe, necessary to connect the specific discourses I am studying to a broader context made of institutions, of actors engaged in power relationships, of policies and policy reforms, of a specific history, of other discourses, etc. The way one build ties between a particular set of data and broader contextual aspects is key to a fruitful sociological analysis. My proposal is to explore the potentialities offered by Cultural Political Economy (Sum & Jessop, 2013), an approach concerned with “the relation between semiosis and structuration in political economy” (Sum & Jessop, 2013: X), when trying to link discourses on R&I to the context they are part of. Acknowledging the “interdependence and co-evolution of the semiotic and extra-semiotic” (ibid., 23), CPE offers heuristic tools to study the articulation of specific discourses “with technologies and agency” (ibid., 20). My communication will disclose the iterative process of discourse analysis relying on CPE, as well as its results. [less ▲]

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See detailThe ICE protocol for ecological continuity: a new tool to evaluate the upstream fish passage success at physical barriers
Ovidio, Michaël ULg; Larinier, Michel; Burgun, Vincent et al

Conference (2015, June)

The recording and classification of obstacles that can interfere with the movements and migrations of fish is critical information to plan river restoration program. To date a major problem is to ... [more ▼]

The recording and classification of obstacles that can interfere with the movements and migrations of fish is critical information to plan river restoration program. To date a major problem is to determine the potential effect of each obstacle and to select the problematic sites that should be improved to restore longitudinal connectivity (construction of fish passage facilities, removal or modification of the obstacles). Fish passage success about an obstacle is complex and depends on the hydraulic conditions over and at the foot of the obstacle in relation to swimming and leaping capabilities of the fish species concerned. This selection and classification is too often biased because managers lack information’s on the fish capabilities to leap physical obstacles. The need for a simple, reliable and standardised assessment method for use by a wide range of environmental stakeholders rapidly became evident. We responded to the challenge and developed the ICE protocol as the basis for the required ecological-continuity assessment method, particularly in the context of the European Water Framework Directive implementation. The ICE protocol coordinated by ONEMA is based on an integration of the topographical and hydraulic characteristics of obstacles with the physical capabilities (swimming, jumping or crawling) of the fish species analysed. It requires the gathering of standardised descriptive variables on each obstacle. The result of the analysis is an indication on the risks of a structure constituting a more or less severe obstacle (5 classes) for a given fish species (n=47) or group of species. Particular attention was paid to the practical aspects of the method (time required and necessary human resources) to facilitate its use in a wide variety of situations and areas. Each procedure is presented as a flow chart to assist in decision-making, thus making the protocol easy to use for a wide range of people. [less ▲]

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See detailWhat can we learn about gamma Doradus star internal structure from Kepler?
Ouazzani, R-M.; Antoci, V.; Salmon, Sébastien ULg et al

Conference (2015, June)

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See detailHistorical evolution of fish biodiversity and capture periodicity in the River Meuse (Belgium) as revealed by 15 consecutive years of fishpass monitoring
Benitez, Jean-Philippe ULg; Dierckx, Arnaud ULg; Nzau Matondo, Billy ULg et al

Conference (2015, June)

In the River Meuse at 323km upstream from the North Sea, the hydroelectric dam of Lixhe (rated power of 5300KW) is equipped with two fishpasses: one pool and weir fishpass (in operation since 1980; 0.13m³ ... [more ▼]

In the River Meuse at 323km upstream from the North Sea, the hydroelectric dam of Lixhe (rated power of 5300KW) is equipped with two fishpasses: one pool and weir fishpass (in operation since 1980; 0.13m³.s-1 operating flow) and one vertical slot fishpass (in operation since 1998; 1m3.s-1 operating flow). Both fishpasses were scientifically monitored using capture traps during 15 consecutive years (from 1999 to 2014). The objective of the study is to analyse i) the evolution of fish stock and biodiversity over 15 years and ii) the capture periodicity of fish and it’s variation over years. During the considered period, we observed 36 species at adult stage (88597 individuals with 75% of cyprinids) and 13 species at juvenile (0+) stage (335067 individuals with 90% of cyprinids). Global results between 1999 and 2014 showed a drastic reduction in capture per year (>90%) for some species like Anguilla Anguilla, Alburnus alburnus, Blicca bjoerkna, Rutilus rutilus and Tinca tinca. Whereas other species have emerged like Aspius aspius and Silurus glanis. For the 0+, an important interannual variation is observed from few individuals to several tens of thousands per year. The comparison between both fishpasses indicated a greater use (>50%) of the vertical slot fishpass by rheophilic species and species that have good swimming ability. The analysis of capture periodicity for the most abundant species at adult stage demonstrated the presence of stable behaviours between years for the Abramis abrama and B. bjoerkna respectively a Q50 of the capture day of the year from 108th to 144th day at mean=17°C and from 118th to 155th day at mean=18°C. In contrast other species have patterns more variables (Barbus barbus: Q50 from 96th to 266th day; R. rutilus: from 10th and 309th day). Finally the 0+ exhibited a capture periodicity stable in time during the summer. [less ▲]

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See detailAnalyser et contraindre les opacités stellaires via les pulsations des étoiles B de séquence
Salmon, Sébastien ULg; Truck-Chièze, S.; Le Pennec, M.

Conference (2015, June)

Les étoiles B de séquence principale, bien que peu nombreuses, présentent un intérêt particulier puisque les plus massives d'entre elles termineront leur évolution par un évènement de type effondrement du ... [more ▼]

Les étoiles B de séquence principale, bien que peu nombreuses, présentent un intérêt particulier puisque les plus massives d'entre elles termineront leur évolution par un évènement de type effondrement du coeur. Parmis les diverses étoiles pulsantes du diagramme d'Hertzsprung-Russell, nous avons la chance de trouver deux types de pulsation au sein des étoiles B de séquence : d'une part celles de type beta Cephei, correspondant à des modes de gravité et acoustiques d'ordres faibles, et d'autre part celles de type SPB (Slowly Pulsating B stars), correspondant à des modes de gravité d'ordres élevés. En étudiant ces pulsations, nous pouvons ainsi améliorer notre connaissance des processus physiques internes des étoiles B de séquence. Nous nous intéressons au cas récent de la détection d'étoiles B pulsantes au sein des Nuages de Magellan, galaxies de si faible métallicité que de telles pulsations n'y étaient pas attendues d'un point de vue théorique. Les pulsations de ces étoiles B sont en effet sensibles à la composition chimique car elles sont activées par le mécanisme kappa, lié à la présence d'un pic d'opacité des éléménts du groupe du fer à une température d'environ 200 000K. Dès lors nous étudions le rôle de la composition chimique et des opacités sur ces pulsations, et mettons en évidence une possible sous-estimation des opacités théoriques. Dans ce cadre, nous présentons les efforts récents du projet OPAC portant sur l'étude des opacités des éléments du groupe du fer, pour des conditions similaires aux enveloppes radiatives des étoiles B. [less ▲]

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See detailThe vortex coronagraph : from laboratory characterization to on-sky operation
Huby, Elsa ULg

Conference (2015, June)

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See detailPromoting Competition at the Digital Age with an Application to Belgium
Lefevre, Mélanie ULg

Conference (2015, June)

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See detailDoes yellow eel prefer old pool and weir or new vertical slot fish pass during their upstream migration?
Nzau Matondo, Billy ULg; Dierckx, Arnaud ULg; Benitez, Jean-Philippe ULg et al

Conference (2015, June)

The hydroelectric dam of Lixhe in the River Meuse, 323km upstream from the North Sea at the entry of Belgium near the frontier with the Netherlands is equipped with two basin fish-passes: – the old pool ... [more ▼]

The hydroelectric dam of Lixhe in the River Meuse, 323km upstream from the North Sea at the entry of Belgium near the frontier with the Netherlands is equipped with two basin fish-passes: – the old pool-and-weir configuration (OFP) operates at low discharge (0.13m3/s) and – the new vertical-slot configuration (NFP) operating at high discharge (1m3/s) with attraction flow (1.5m3/s). However, the utilization rate of these fish-passes by the incoming yellow eels remains unknown, because the trap of NFP is not adapted to retain anguillids and small species. Yet, such knowledge is crucial to improve the inland colonization of the species and to increase our understanding of fish-pass utilization given its particular swimming mode. In season 2013, eels caught two times a week using a cone-trap pool in the OFP and net traps in the NFP, were tagged and released the same day 0.3km downstream (n = 396eels). The utilization of OFP and NFP was studied using automatic RFID transponder detection antennas placed in upstream basins of the fish-passes, during years 2013 and 2014. Results revealed that the OFP was the preferred migration route of eels (eel numbers, OFP:NFP, 2013= 88:51 and 2014= 41:16, χ²-test, p<0.0001), which was also used earlier in season. Eels displayed fidelity to their catch fish-passes (>70% of the detected eels, annually). Detection rate was high in the year of eel tagging (2013: 35.1%) before decreasing in the following year (2014: 14.4%). Eels used these fish-passes the night from 22:00 to 04:00, at 14-26°C, river flow <200m³/s and whenever waxing and waning phases of moonlight. Our results provide insight into the utilization of fish-passes by migrating eels. The study suggests further reflection before removing the old fish-pass in large rivers and to think about the eel attractiveness and comfort when the construction of a new fish pass is planned. [less ▲]

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See detailValidation of the SAMCEF material models for inter and intralaminar damages in laminated composites made of NCF plies
Bruyneel, Michaël ULg; Delsemme, Jean-Pierre; Jetteur, Philippe et al

Conference (2015, June)

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See detail“Elements of the Sublime (and the Grotesque) in Crime Fiction”
Dechene, Antoine ULg

Conference (2015, June)

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See detailImportance of the reconciliation method to handle experimental data: application to a reversible heat pump / organic Rankine cycle unit integrated in a positive energy building
Dumont, Olivier ULg; Quoilin, Sylvain ULg; Lemort, Vincent ULg

Conference (2015, June)

Experimental data is often the result of long and costly experimentations. Many times, measurements are used directly without (or with few) analysis and treatment. This paper therefore presents a detailed ... [more ▼]

Experimental data is often the result of long and costly experimentations. Many times, measurements are used directly without (or with few) analysis and treatment. This paper therefore presents a detailed methodology to use steady-state measurements efficiently in the analysis of a thermodynamic cycle. The reconciliation method allows to correct each measurement as little as possible, taking its accuracy into account, in order to satisfy all constraints and to evaluate the most probable physical state. The reconciliation method should be used for multiple reasons. First, this method allows to close energy and mass balances exactly, which is needed for predictive models. Also, it allows determining some unknowns that are not or that cannot be measured precisely. Furthermore, it fully exploits the collected measurements with redundancy and it allows to know which sensor should be checked or replaced if necessary. An application of this method is presented in the case of a reversible HP/ORC unit. This unit is a modified heat pump which is able to work as an organic Rankine cycle by reversing its cycle. Combined with a passive house comprising a solar roof and a ground heat exchanger, it allows to get a plus energy house. In this study case, the oil mass fraction is not measured despite of its strong influence on the results. The reconciliation method allows to evaluate it. The efficiency of this method is proven by comparing the error on the outputs of steady-state models of compressor and exchangers. An example is given with the prediction of the pinch-point of an evaporator. In this case, the normalized root mean square deviation (NRMSD) is decreased from 14.3 % to 4.1 % when using the reconciliation method. This paper proves the efficiency of the method and also that the method should be considered more often when dealing with experimentation. [less ▲]

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See detailAuroral Morphologies of Jupiter and Saturn
Grodent, Denis ULg

Conference (2015, May 31)

We review the principal differences and similarities of the morphologies of Jupiter and Saturn's auroral emissions. We then show some examples of UV images that are expected to be acquired with Cassini ... [more ▼]

We review the principal differences and similarities of the morphologies of Jupiter and Saturn's auroral emissions. We then show some examples of UV images that are expected to be acquired with Cassini UVIS at Saturn and Juno UVS at Jupiter. [less ▲]

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See detailComparing central western Europe Mesolithic and Neolithic plant processing microwear on flint tool
Linton, Jimmy ULg; Guéret, Colas; Gassin, Bernard

Conference (2015, May 30)

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See detailApproche processuelle de la dépression : Impact de processus psychologiques l'activation ou l'évitement en fonction du sexe
Wagener, Aurélie ULg

Conference (2015, May 29)

La dépression est caractérisée par des symptômes affectifs, cognitifs et somatiques. Elle est également caractérisée par une diminution du niveau d’engagement dans des activités ce qui peut être ... [more ▼]

La dépression est caractérisée par des symptômes affectifs, cognitifs et somatiques. Elle est également caractérisée par une diminution du niveau d’engagement dans des activités ce qui peut être conceptualisé comme de l’évitement comportemental (symptôme comportemental). Il est en effet fréquent que les patients dépressifs s’engagent de moins en moins dans des activités qui leur plaisaient auparavant (voir des amis, etc.) Ce faible niveau d’activités maintient leur humeur dépressive. Cette relation entre dépression et faible niveau d’engagement dans des activités est bien établie dans la littérature scientifique mais les relations entre les processus cognitifs sous-jacents sont encore mal connues. Selon les modèles théoriques de la dépression (Beck, 2008; Lewinsohn, 1985; Watkins, 2009), cinq types de processus psychologiques (PP) sont impliqués dans la symptomatologie dépressive : les pensées négatives répétitives, les stratégies de régulation émotionnelle non-adaptées, un faible niveau de satisfaction environnementale, une image de soi négative et une tendance à l’inhibition. Nous faisons l’hypothèse que ces PP pourraient être les facteurs explicatifs de l’évitement comportemental. Par ailleurs, nous faisons également l’hypothèse que d’autres PP pourraient être considérés comme des facteurs explicatifs de l’activation comportementale : les stratégies de régulation émotionnelle adaptées, un haut niveau de satisfaction environnementale, une image de soi positive, une tendance à l’approche et un concept de soi clair. Ces PP consisteraient en des facteurs protecteurs de la dépression. Dès lors, notre objectif est d’évaluer les liens entre évitement comportemental, activation comportementale et PP. Pour ce faire, en nous basant sur le modèle de Kinderman (2013), nous avons élaboré un modèle conceptualisant l’influence que peuvent avoir les PP précités sur, d’une part, l’évitement comportemental et, d’autre part, l’activation comportementale. De plus, l’étude évalue l’adéquation de ce modèle de façon à comparer les hommes et les femmes. 477 adultes issus de populations cliniques et non-cliniques (119 hommes, 358 femmes, âge moyen = 34,25, ET = 11,85) ont complété une étude en ligne évaluant les PP (pensées négatives répétitives, stratégies de régulation émotionnelles, satisfaction environnementale, image de soi, tendance à l’inhibition/l’approche, clarté du concept de soi), l’évitement comportemental et l’activation comportementale. Différents questionnaires évaluaient chacun de ces PP. Dès lors, des scores factoriels ont été réalisés pour représenter chaque PP. Les résultats préliminaires issus d’analyses factorielles confirmatoires semblent révéler des différences entre les hommes et les femmes. Pour les hommes, une image de soi négative, des stratégies de régulation émotionnelle non-adaptées et un faible niveau de satisfaction environnementale sont liés à l’évitement comportemental alors qu’un haut niveau de satisfaction environnementale et une image de soi positive sont liés à l’activation comportementale. Pour les femmes, un faible niveau de satisfaction environnementale, des stratégies de régulation émotionnelle non-adaptées et des pensées négatives répétitives sont liées à l’évitement comportemental alors qu’un haut niveau de satisfaction environnemental et une image de soi positive sont liées à l’activation comportementale. La collecte des données étant toujours en cours, les résultats globaux seront présentés durant le congrès. Les implications cliniques de ces résultats seront discutées telles que la pertinence de travailler sur le niveau de satisfaction environnementale. [less ▲]

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See detailDe l’ordre répressif étatique à celui de la Cour pénale internationale : la sensibilité du juge de Strasbourg à la gravité des faits en cause
Deprez, Christophe ULg

Conference (2015, May 29)

Cette présentation PowerPoint a servi de support à une communication orale dans le cadre de l'édition 2015 de la Conférence des Assistants en droit de Belgique (ACCA), organisée le 29 mai 2015 par l ... [more ▼]

Cette présentation PowerPoint a servi de support à une communication orale dans le cadre de l'édition 2015 de la Conférence des Assistants en droit de Belgique (ACCA), organisée le 29 mai 2015 par l'Université catholique de Louvain. [less ▲]

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See detailToward a more precise terminology for impact damage and an improved understanding of hunting weapons: First results from a large scale systematic experiment
Coppe, Justin ULg; Rots, Veerle ULg

Conference (2015, May 29)

Projectile points have recently taken an important place in debates on the complexity of Palaeolithic human behaviour. While the appearance of hunting weapons in the archaeological record was an important ... [more ▼]

Projectile points have recently taken an important place in debates on the complexity of Palaeolithic human behaviour. While the appearance of hunting weapons in the archaeological record was an important element in the past, current discussions focus a lot on the appearance of particular hunting methods. Distinctions are made between simple and complex weaponry, the latter assumed to be linked with modern humans only. While most of the identifications of hunting weapons in the archaeological record rely on the examination of so-called diagnostic impact damage, no reliable reference yet exist for distinguishing between hunting methods. We present the first results of a large-scale and systematic experiment that intends to address hunting weapons in a systematic way. A thorough survey of the literature has highlighted some existing ambiguity in current terminological frameworks for describing impact fractures. Based on our experiments, we propose some attributes that may be relevant for improving these terminologies. Attention will also be devoted to the design and conceptual framework of our experimental program and to some first results concerning the essential variables influencing damage formation. The overall goal is to improve our understanding of the different fracture phenomena and their variability in order to enhance the reliability of the identification of hunting weapons and perhaps of their projecting mode. [less ▲]

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See detailQuelles caractéristiques du passage à la retraite ont un impact sur la cognition du sujet âgé ? Résultats de la cohorte AMI
Grotz, Catherine ULg; Matharan, Fanny; Amieva, Hélène et al

Conference (2015, May 29)

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See detailTowards an experiment based protocol for extracting and identifying residues
Cnuts, Dries ULg; Rots, Veerle ULg

Conference (2015, May 29)

Residue analysis has recently become a widely applied method in reconstructing the lifecycle of prehistoric stone tools. The identification of residues is traditionally based on the distinctive ... [more ▼]

Residue analysis has recently become a widely applied method in reconstructing the lifecycle of prehistoric stone tools. The identification of residues is traditionally based on the distinctive morphologies of the residue fragments by means of light microscopy. The majority of residue fragments, however, tend to have an amorphous structure and are therefore not easy to identify. In addition, some residue categories can only be detected by using transmitted light microscopy, which requires the extraction of residues from the tool’s surface. Yet another challenge is to determine whether the residues were deposited on the tool’s surface as a result of use or due to other processes. Here we present the results of an experimental study that addresses these methodological issues. Stone tools from a new experimental reference collection were used to test 6 different analytical methods: the observation of residues on stone tools with incident light microscopy, dry sampling using tweezers and brushes, wet sampling with micropipettes using distilled water and a tri-mixture of acetonitrile, ethanol and water, and extraction with an ultrasonic scaler or bath. The experiments demonstrate that the choice of a particular extraction procedure may influence the amount and types of residues that are extracted. This implies that the analytical method has an impact on the results of a residue analysis. Building on these data, we designed a new protocol, which was subsequently submitted to blind testing in order to test its accuracy and precision. Certain key attributes were also identified that may prove useful in distinguishing between use-related and natural residues. We discuss the importance of adapting analytical protocols to the research question of the study. [less ▲]

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See detailEsthésies: Approches plastiques du sensible. Introduction.
Ebert-Schifferer, Sybille; Havelange, Carl ULg; Von Hoffmann, Viktoria ULg

Conference (2015, May 29)

La peinture semble révéler, avant toute chose, l’expérience sensible du voir. Mais ne peut-elle pas, aussi, dans certains cas, faire percevoir par l’œil quelque chose qui relèverait d’un autre ordre ... [more ▼]

La peinture semble révéler, avant toute chose, l’expérience sensible du voir. Mais ne peut-elle pas, aussi, dans certains cas, faire percevoir par l’œil quelque chose qui relèverait d’un autre ordre sensoriel ? Peut-on goûter, sentir, entendre, toucher avec les yeux ? Si les spécialistes se sont beaucoup interrogés sur le passage du sensible à l’art – notamment sur la place de la nature dans les œuvres d’art anciennes, où on sait l’importance culturelle qu’y exerçait la mimesis –, le passage de l’art au sensible est, quant à lui, plus rarement considéré. La représentation visuelle du sensible a souvent été envisagée à travers l’étude de l’iconographie des cinq sens, qui a déjà fait l’objet de plusieurs études, profitant de l’essor fécond de l’histoire des cultures sensibles et, plus largement, du succès rencontré par les sensory studies depuis quelques dizaines d’années. Plusieurs publications et expositions ont été consacrées à cette problématique, en particulier depuis les travaux de Carl Nordenfalk. Le plus souvent, toutefois, les recherches sur le sujet tendent à privilégier une analyse que nous pourrions qualifier de sémiotique (qui donne à lire un sens), portant sur des images qui rassemblent un ensemble d’éléments visuels dotés d’une valeur symbolique. C’est le cas de nombreuses gravures – les emblèmes, par exemple – et de peintures, telles que les allégories représentant la série des cinq sens, ou les natures mortes – en particulier celles de la première génération. Ne peut-on toutefois envisager d’explorer la figuration picturale du sensible autrement que par la voie symbolique ? Il semble en effet qu’il existe un autre type de regard possible, interrogeant différemment la peinture où le sensible est mis en jeu, et qui prendrait appui sur le concept d’esthésie. Les images esthésiques (qui donnent à percevoir une sensation) seraient ainsi celles qui semblent traduire l’expérience sensorielle elle-même. La question se pose, notamment, pour la nature morte. Il suffit de penser à la dimension presque tactile de certaines peintures, à la puissance d’évocation de tableaux qui paraissent – comme le disait Diderot à propos de Chardin – vouloir faire goûter au spectateur l’aliment représenté sur la toile. Mais la problématique est vaste et susceptible de concerner bien d’autres types de productions artistiques – la sculpture, la photographie, le cinéma. L’idée même d’esthétique renvoie, étymologiquement, à la perception sensible. Cette question engage dès lors tant l’historien de l’art que le philosophe, l’historien, l’anthropologue ou le spécialiste des études littéraires. L’objectif de la journée d’étude sera de réfléchir la cohérence théorique de ce concept d’esthésie, en privilégiant une réflexion ouverte du point de vue des disciplines, des méthodes et des objets. Il s’agira d’envisager tant la production que la consommation des images (S. Ebert-Schifferer), c’est-à-dire la nature de l’effet sensible produit sur le spectateur par la contemplation d’une œuvre d’art. Comment l’art traduit-il non seulement le visuel, mais également le tactile, l’olfactif, l’auditif, le gustatif ? Comment, en somme, s’opère le passage secret qui conduit du visible à l’esthésique ? [less ▲]

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See detailEsthésies. Conclusions
Ebert-Schifferer, Sybille; Von Hoffmann, Viktoria ULg

Conference (2015, May 29)

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See detailAntitrust and The challenge of policing « moligopolists »
Petit, Nicolas ULg

Conference (2015, May 29)

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See detailStone tool hafting and use in the European Upper Palaeolithic: the first results of the analysis of Gravettian tools from Hohle Fels
Taipale, Noora ULg; Rots, Veerle ULg

Conference (2015, May 28)

European Upper Palaeolithic lithic assemblages have been so far defined largely on a typological or technological basis, while extensive studies that would utilise the full potential of microwear analysis ... [more ▼]

European Upper Palaeolithic lithic assemblages have been so far defined largely on a typological or technological basis, while extensive studies that would utilise the full potential of microwear analysis have been few. This contribution presents the first results of an ongoing PhD project dedicated to the variability in stone tool use and hafting in the Upper Palaeolithic of Central and Western Europe. The aim of the project is to understand the development as well as regional patterns in tool hafting and use in the Gravettian and Magdalenian, and thus better explain the observed morphological and technological shifts. For this purpose, samples of tools from five European key sites with well-dated sequences (Hohle Fels, Geißenklösterle, Vogelherd, Maisières-Canal, and Abri Pataud) will be analysed giving a special emphasis on hafting traces. The study wishes to promote functional analysis as an integral part of technological studies, not as a mere side note. The German cave site Hohle Fels is used here as a case study to illustrate the potential of this kind of approach. The first results of the analysis of the site’s Gravettian material will be put into a wider context of earlier published results as well as preliminary observations made on the other assemblages included in the present study. Building on these results, the impact of tool hafting and use on the morphology of Gravettian lithic implements will be discussed. [less ▲]

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See detailFully automated electrophoretically mediated microanalysis system for CYP1A1 activity monitoring
Farcas, Elena ULg; Servais, Anne-Catherine ULg; Lamalle, Caroline ULg et al

Conference (2015, May 28)

In order to evaluate the potentiality of capillary electrophoresis for CYP1A1 activity monitoring, an in-line method was developed with the well-known 7-ethoxycoumarin substrate. The electrophoretically ... [more ▼]

In order to evaluate the potentiality of capillary electrophoresis for CYP1A1 activity monitoring, an in-line method was developed with the well-known 7-ethoxycoumarin substrate. The electrophoretically mediated microanalysis approach was used with CYP1A1 supersomes to provide a rapid and fully automated method. The in-line homogenous enzyme assay was performed in physiological conditions (pH 7.4), whereas a MEKC buffer was used as background electrolyte. In order to reduce the analysis time, the short end injection was performed. Firstly a plug containing CYP1A1 supersomes was hydrodynamically injected into a fused silica capillary, followed by a plug of co-factor (NADPH) and substrate (7-ethoxycoumarin) and finally another plug of CYP1A1 (sandwich mode). The experimental conditions were finely investigated and tuned by design of experiment methodology. The metabolization rate measured in the optimized conditions was comparable with the one obtained after off-line metabolization. Finally, inhibition studies were conducted and a significant decrease of 7-hydroxycoumarin formation was observed using apigenin as CYP1A1 potent inhibitor. [less ▲]

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See detailThe hot Jupiter WASP-­121 b: A planet heading towards its doom
Delrez, Laetitia ULg

Conference (2015, May 28)

We present here the discovery by the WASP-South survey, in close collaboration with the Euler and TRAPPIST telescopes, of WASP-121 b, a new remarkable short-period transiting hot Jupiter. WASP-121 b is a ... [more ▼]

We present here the discovery by the WASP-South survey, in close collaboration with the Euler and TRAPPIST telescopes, of WASP-121 b, a new remarkable short-period transiting hot Jupiter. WASP-121 b is a very inflated (1.86 Rjup) Jupiter-mass (1.18 Mjup) planet that transits every 1.27 days a bright active F6V star. A notable property of WASP-121b is that its orbital semi-major axis is only 15% larger than its Roche limit, which suggests that the planet might be close to tidal disruption. Furthermore, its large size and extreme irradiation (7.1 10^9 erg s^-1 cm^-2) make it an excellent target for atmospheric studies via secondary eclipse observations. Using the TRAPPIST robotic telescope, we indeed detect its thermal emission in the z’-band at better than ~4sigma, the measured occultation depth being 603+-130 ppm. This measurement is a first for a ground-based 60cm telescope. Finally, from a measurement of the Rossiter-McLaughlin effect with the CORALIE spectrograph, we infer a sky-projected spin-orbit angle of 257.8+-6 deg. This result indicates a significant misalignment between the spin axis of the host star and the orbital plane of the planet, the planet being in a nearly polar orbit. [less ▲]

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See detailLe donné phénoménal de Tim Crane
Gauvry, Charlotte ULg

Conference (2015, May 28)

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See detailIs Büchi's theorem useful for you?
Rigo, Michel ULg

Conference (2015, May 28)

Almost a century ago, Presburger showed that the first order theory of the natural numbers with addition is decidable. Following the work of Büchi in 1960, this result still holds when adding a function ... [more ▼]

Almost a century ago, Presburger showed that the first order theory of the natural numbers with addition is decidable. Following the work of Büchi in 1960, this result still holds when adding a function $V_k$ to the structure, where $V_k(n)$ is the largest power of $k\ge 2$ diving $n$. In particular, this leads to a logical characterization of the $k$-automatic sequences. During the last few years, many applications of this result have been considered in combinatorics on words, mostly by J. Shallit and his coauthors. In this talk, we will present this theorem of Büchi where decidability relies on finite automata.Then we will review some results about automatic sequences or morphic words that can be proved automatically (i.e., the proof is carried on by an algorithm). Finally, we will sketch the limitation of this technique. With a single line formula, one can prove automatically that the Thue-Morse word has no overlap but, hopefully, not all the combinatorial properties of morphic words can be derived in this way. [less ▲]

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See detailAn ALE meta-analysis on the neural correlates of personal goal processing during episodic future thoughts and mind-wandering
Stawarczyk, David ULg; D'Argembeau, Arnaud ULg

Conference (2015, May 28)

The ability to project oneself into the future is a multi-determined mental faculty that depends on various cognitive processes supported by an extended set of brain regions. The aim of the present study ... [more ▼]

The ability to project oneself into the future is a multi-determined mental faculty that depends on various cognitive processes supported by an extended set of brain regions. The aim of the present study was to examine a crucial component of future thinking—personal goal processing—and to determine its neural correlates during both experimentally directed mental time travel towards the future and mind-wandering, a form of spontaneous thoughts characterized by a prospective bias towards upcoming events. To address this question, we performed three distinct ALE meta-analyses of brain imaging studies on episodic future thinking, mind-wandering, and personal goal processing. We then examined the commonalities and differences in brain activity between these three areas of research. The results showed that the three domains activated a common set of brain regions within the default network including the posterior inferior parietal cortex, posterior cingulate cortex, lateral temporal lobe, and, most notably, the medial prefrontal cortex. Differences in activation were also observed, and the medial prefrontal cortex was more activated during personal goal processing than the other two domains. These findings suggest that the medial prefrontal cortex mediates the processing of personal goals during both episodic future thinking and mind-wandering. [less ▲]

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See detailThe more you know...........various approaches in the analysis of tools from Liang Bua, Flores Indonesia
Lentfer, Carol ULg; Stephenson, Birgitta; Cnuts, Dries ULg et al

Conference (2015, May 28)

Chipped stone flakes from sedimentary deposits from the Liang Bua site, Flores, Indonesia have been found in association with faunal remains and skeletal remains identified as Homo floresiensis. Use-wear ... [more ▼]

Chipped stone flakes from sedimentary deposits from the Liang Bua site, Flores, Indonesia have been found in association with faunal remains and skeletal remains identified as Homo floresiensis. Use-wear and well-preserved organic residues on these flakes provide an opportunity to understand subsistence and behaviour of Homo floresiensis by determining how they were manipulated and what they were used for. This paper describes the analytical techniques including various microscope and staining methodologies used in residue analyses. It compares the efficacy and describes the outcome of these techniques in relation to the functional analysis of the Liang Bua lithic assemblage. [less ▲]

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See detailQuelle place accorder aux écritures de la réception dans le contexte de la formation initiale? Du comportement des futurs enseignants face à des médiations de la lecture à l'élaboration de dispositifs de formation
De Croix, Séverine ULg; Ledur, Dominique

Conference (2015, May 28)

L’exploitation des écritures de la réception en formation initiale des enseignants fait aujourd’hui l’objet d’un large consensus (Joole, 2013 ; Chabanne & Dufays, 2011; Mazauric, Fourtanier & Langlade ... [more ▼]

L’exploitation des écritures de la réception en formation initiale des enseignants fait aujourd’hui l’objet d’un large consensus (Joole, 2013 ; Chabanne & Dufays, 2011; Mazauric, Fourtanier & Langlade, 2011 ; Vanhulle & Schillings, 2004). Nous souhaitons nous interroger sur les moyens, les objectifs et les effets attendus de cette exploitation (axe 4 de l’appel à communications). Le présent projet porte, dans un premier temps, sur l’observation des réactions d’une centaine de futurs enseignants de français du secondaire, tous niveaux confondus, face à un corpus de médiations écrites de la lecture, produites par des élèves de 12 à 18 ans, lecteurs experts et en difficulté. Ces écrits relèvent de genres diversifiés (journaux de lecture, notes critiques, traces collectées à l’occasion d’un dévoilement progressif, réponses à des questions, etc.) et de statuts différents (écrits de travail ou productions finales susceptibles d’être évaluées). Les consignes d’analyse devaient conduire les étudiants à repérer les éventuelles difficultés des lecteurs (ou leurs réussites), à reconstruire les tâches, à relever différents positionnements face aux textes, etc. Nos constats mettent notamment en évidence une tendance à investir ces écrits de façon normative (prédominance des difficultés du lecteur, notamment linguistiques, au détriment d’une prise en compte des difficultés générées par les textes et/ou les tâches scolaires) et une faible conscience de la complexité de l’activité de compréhension/interprétation. L’analyse des données collectées à l’occasion de ce travail incite, dans un deuxième temps, à privilégier quatre directions pour apprendre aux futurs maitres de lecture à lire des écrits de la réception et pour les amener par ce biais à développer des compétences et gestes professionnels en didactique de la lecture littéraire : modéliser l’activité de compréhension/interprétation, identifier les éventuelles difficultés de lecture, sélectionner des textes pour la classe et les associer à des médiations adaptées, percevoir les caractéristiques et les visées des tâches (y compris anticiper les éventuels malentendus générés par celles-ci et organiser leur progression). Ces axes d’intervention seront illustrés par quelques exemples de dispositifs de formation. [less ▲]

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See detailHeterogeneity of multitasking abilities in schizophrenia.
Laloyaux, Julien ULg; Van der Linden, Martial ULg; Laroi, Frank ULg

Conference (2015, May 28)

Difficulties in everyday life activities are core features of persons diagnosed with schizophrenia, and in particular for those activities requiring multitasking capacities. Multitasking refers to ... [more ▼]

Difficulties in everyday life activities are core features of persons diagnosed with schizophrenia, and in particular for those activities requiring multitasking capacities. Multitasking refers to activities (e.g. preparing a meal) where the person has to: (a) carry out and alternate between different tasks that vary in terms of priority, difficulty and duration; (b) define the tasks’ targets; (c) and face unexpected problems during the realization of these tasks. Moreover, schizophrenia is characterized by a great heterogeneity in regard to their everyday life difficulties and cognitive functioning. At present, patients’ multitasking capacities have not been adequately examined in the literature due to an absence of suitable assessment strategies. We thus recently developed a computerized real-life activity task designed to take into account the complex and multitasking nature of certain everyday life activities where participants are required to prepare a room for a meeting (i.e. the Computerized Meeting Preparation Task, CMPT). The aim of this study was to examine the multitasking abilities in persons diagnosed with schizophrenia and in particular the existence of subgroups of patients in regard to their performances on cognitive measures and on the CMPT. Sixty-two patients diagnosed with schizophrenia and 39 paired healthy controls completed the CMPT and a cognitive battery. The results reveal that the CMPT possesses good sensitivity and suggest three underlying constructs of multitasking (Memory, Planning and Intent), which were found to be underpinned by several cognitive functions and multitasking aspects. Moreover, cluster analyses revealed subgroups of patients differing in terms of their cognitive and CMPT performances. Taken together, these results show the need for a cognitive model of multitasking abilities in persons diagnosed with schiozphrenia. Taken together, this cognitive model and the CMPT, could be a good basis for cognitive interventions of multitasking abilities in schizophrenia. Finally, the results underline the heterogeneity of schizophrenia. [less ▲]

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See detailTool use and hafting in the Middle Palaeolithic of Northern Africa An on-going use-wear analysis on the Mousterian/Aterian assemblages of Ifri n’Ammar (Morocco)
Tomasso, Sonja ULg; Rots, Veerle ULg

Conference (2015, May 28)

The so-called “Aterian Culture” has received attention since the early days of prehistoric archaeology in Northern Africa. Several definitions were proposed, which triggered a debate around this cultural ... [more ▼]

The so-called “Aterian Culture” has received attention since the early days of prehistoric archaeology in Northern Africa. Several definitions were proposed, which triggered a debate around this cultural concept. In particular the presence of the tanged tools was a crucial element in these debates and the tangs were considered to potentially represent the earliest indications of hafting, or at least of intentional morphological adaptations in view of hafting. In contrast to numerous typological and technological studies of Aterian and Mousterian assemblages, use-wear analyses have been scarce up until today. However, for a better understanding of several aspects of these Middle Palaeolithic “cultures”, functional data needs to be taken into consideration. Given the issue of tanged pieces, the potential of such detailed studies on production, hafting and use is high. In this paper, the first results will be presented of an on-going use-wear analysis on tools from the Aterian/Mousterian assemblages of Ifri n’Ammar. This rock shelter presents an ideal case thanks to its particularly rich and well preserved stratigraphy. Around 200 artefacts have been selected up to now, based on their degree of preservation and without restrictions on the level of the tool types. Artefacts were examined macroscopically and microscopically in a search for evidence of their production, hafting and use and an experimental program was set up. Archaeological interpretations are based on new experiments, as well as on the existing large experimental reference collection available at TraceoLab at the University of Liège. The long-term goal of the study is to use a functional approach to answer questions related to lithic assemblage variability. At Ifri n’Ammar, it is clear that the tangs occur on a variety of tools. Due to the presence of tangs in the Aterian and their absence in the Mousterian, it can be hypothesized that there was a shift in hafting techniques between the two cultures/periods. In order to understand whether this change was triggered by functional, cultural, or environmental factors, more functional data is clearly needed. [less ▲]

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See detailTel Quel, Change et Poétique en 1970 : "l'affaire de Lausanne"
Lorent, Fanny ULg

Conference (2015, May 27)

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See detailApplication du plan d’expérience de Box-Behnken et de la méthodologie des surfaces de réponses pour optimiser une méthode de quantification de phyto-œstrogènes dans les fourrages
Daems, Frédéric ULg; Lognay, Georges ULg; Romnee, Jean-Michel et al

Conference (2015, May 27)

Dans le cadre d’un projet de valorisation des prairies, intitulé « PhytoHealth », une méthode d’analyse quantitative constituée d’une étape d’extraction à l’aide d’un bain à ultrasons, suivi d’une ... [more ▼]

Dans le cadre d’un projet de valorisation des prairies, intitulé « PhytoHealth », une méthode d’analyse quantitative constituée d’une étape d’extraction à l’aide d’un bain à ultrasons, suivi d’une hydrolyse enzymatique et d’une analyse par UPLC®-MS/MS a été développée pour assurer le dosage de phyto-œstrogènes dans les fourrages. Pour alléger l’optimisation de la préparation des échantillons, la méthodologie des surfaces de réponses a été utilisée. Un plan d’expérience de Box-Behnken a été appliqué aux étapes d’extraction et d’hydrolyse. Parmi les différents facteurs pris en compte, les impacts de la nature du solvant utilisé lors de l’extraction ainsi que la température et le pH lors de l’hydrolyse, ont clairement pu être mis en évidence. L’ensemble des données générées a également permis de définir des conditions optimales d’extraction et d’hydrolyse pour chacun des composés. Ces conditions n’étant pas identiques pour chacun d’entre eux, un compromis a été trouvé afin de pouvoir analyser l’ensemble de ces composés simultanément. L’ensemble de la méthode a ensuite été validée selon les recommandations de l’EMA/CVMP/VICH/463202/2009, pour confirmer sa fiabilité et robustesse. Cette dernière, combinée au model d’ensilage en sacs sous vide, a permis pour la première fois de suivre la cinétique d’évolution de 4 phyto-œstrogènes (daidzéine, génistéine, formononétine et biochanin A) durant une période d’ensilage. [less ▲]

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See detailControl of nuclear sample polarization using optical pumping and radio-frequency methods
Lenaers, Florence ULg; Glover, Rohan ULg; Bastin, Thierry ULg

Conference (2015, May 27)

Laser-cooled and trapped radioactive isotopes are now being used to probe the properties of the weak interaction in nuclear beta decay. In this context, it is essential that one be able to control the ... [more ▼]

Laser-cooled and trapped radioactive isotopes are now being used to probe the properties of the weak interaction in nuclear beta decay. In this context, it is essential that one be able to control the nuclear polarization of the atomic samples. We present two polarization/depolarization schemes for argon-35, whose mirror transition to chlorine-35 is a particularly sensitive candidate for precision measurements in nuclear beta decay. [less ▲]

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See detailDirect Numerical Simulation of Mixed Convection in Turbulent Channel Flow: On the Reynolds number dependency of momentum and heat transfer under unstable stratification
Sid, Samir ULg; Dubief, Yves; Terrapon, Vincent ULg

Conference (2015, May 27)

Direct numerical simulations of unstably stratified turbulent channel flow have been performed in order to investigate the Reynolds number effect on mixed convection. Six different cases are considered ... [more ▼]

Direct numerical simulations of unstably stratified turbulent channel flow have been performed in order to investigate the Reynolds number effect on mixed convection. Six different cases are considered with friction Reynolds number Re_\tau =180 and 395 and friction Richardson number Ri_\tau = 0, 100 and 1000. It is shown that both friction coefficient and Nusselt number increase under unstable stratification for a sufficiently large Richardson number. At low Richardson number, the friction coefficient can either increase or decrease depending on the Reynolds number. The drag reduction is associated with an increase of mean velocity due to an enhanced dissipation of Reynolds shear stress by pressure strain in the buffer region. The breakdown of the Reynolds analogy is demonstrated as the turbulent Prandtl number exhibits a non-constant behavior due to buoyancy. [less ▲]

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See detailDense-lineability in classes of ultradifferentiable functions
Esser, Céline ULg

Conference (2015, May 27)

The Denjoy-Carleman classes are spaces of smooth functions which satisfy growth conditions on their derivatives defined through weight sequences. In this talk, given a Denjoy-Carleman class E of Beurling ... [more ▼]

The Denjoy-Carleman classes are spaces of smooth functions which satisfy growth conditions on their derivatives defined through weight sequences. In this talk, given a Denjoy-Carleman class E of Beurling type that strictly contains another non-quasianalytic class F of Roumieu type, we handle the question of knowing how large the set of functions in E that are nowhere in the class $F$ is. In particular, we prove the dense-lineability of the set of functions of $E$ which are nowhere in F. Consequences for the Gevrey classes are also given. We extend then these results to the case of classes of ultradifferentiable functions defined imposing conditions on their Fourier Laplace transform using weight functions. [less ▲]

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See detailValidation d'une méthode d'analyse quantitative de l'équol par UPLC®-MS/MS dans le lait de vache - Application aux laits commercialisés en Wallonie (Belgique)
Daems, Frédéric ULg; Lognay, Georges ULg; Romne, Jean-Michel et al

Conference (2015, May 27)

Dans le cadre d’un projet intitulé «PhytoHealth », une méthode d’analyse quantitative de l’équol dans le lait a été développée et validée selon les recommandations de l’EMA/CVMP/VICH/463202/2009. Celle-ci ... [more ▼]

Dans le cadre d’un projet intitulé «PhytoHealth », une méthode d’analyse quantitative de l’équol dans le lait a été développée et validée selon les recommandations de l’EMA/CVMP/VICH/463202/2009. Celle-ci est constituée d’une étape d’hydrolyse enzymatique, suivie d’une double extraction liquide/liquide et d’une analyse par chromatographie liquide ultra performante couplé à un spectromètre de masse en tandem (UPLC®-MS/MS). Une fois les différents paramètres tels que la fiabilité, sensibilité et/ou robustesse de la méthode confirmées, celle-ci a permis, pour la première fois, d’estimer la teneur en équol d’ échantillons de laits commercialisés en Wallonie. Une Cinquantaine de laits ont été prélevés aléatoirement dans les commerces durant une période définie. Tous les échantillons possédaient une teneur en équol ≥ 10ng.mL-1. En comparant les valeurs moyennes, on a constaté qu’il n’y avait pas de différence entre les 4 catégories de laits analysés (entier, demi-écrémé, écrémé et cru). Par contre, une différence hautement significative a pu être observée entre les laits provenant de la filière biologique et ceux de la filière conventionnelle. Dans le premier cas, les teneurs varient entre 10 et 50 ng.mL-1 par contre, dans le second, elles varient entre 70 et 130 ng.mL-1. Cet impact de la filière biologique sur la teneur en équol dans les laits a pu être confronté à d’autres études européennes et confirmé. [less ▲]

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See detailVenus nightglow intensity and solar activity: any correlation?
Soret, Lauriane ULg; Gérard, Jean-Claude ULg

Conference (2015, May 26)

We examine if any correlation is observed between the brightness of the O2 nightside airglow and the EUV solar irradiance using the full database of VIRTIS IR images. We conclude that, as was the case for ... [more ▼]

We examine if any correlation is observed between the brightness of the O2 nightside airglow and the EUV solar irradiance using the full database of VIRTIS IR images. We conclude that, as was the case for the NO airglow observed during the Pioneer Venus mission, no response to solar activity is observed. [less ▲]

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See detailProcess-based method for groundwater resource vulnerability mapping with regards to solute contamination at the surface
Popescu, Cristina; Brouyère, Serge ULg; Orban, Philippe ULg et al

Conference (2015, May 26)

Numerous groundwater vulnerability methods have been developed taking into consideration a variable number of factors. The most common techniques are based on calculation of an index expressing the ... [more ▼]

Numerous groundwater vulnerability methods have been developed taking into consideration a variable number of factors. The most common techniques are based on calculation of an index expressing the protective effect of underground formations overlying the groundwater resource. However, it has been shown that different overlay and index methods applied to the same system can yield dramatically dissimilar results (among others, Gogu et al., 2003). The limitation of most of these methods is related to their use of a qualitative definition of groundwater vulnerability, as opposed to a definition based on a quantitative description of contaminant migration. A process-based point of view is proposed and based on three factors describing a pollution event (Brouyère et al., 2001): (1) the transit time from the source to the target, (2) the duration of the contamination breakthrough at the target, (3) the ratio between the maximum concentration at the target to the released concentration at the contamination source. The assessment can then be based on the impulse response at the ‘target’ to a Dirac-type solicitation (point, unit mass, instantaneous source of pollution), considering only physical hydrodispersive processes for intrinsic vulnerability and both physical and biochemical processes for specific vulnerability. The breakthrough curve obtained after a vertical transfer through the overlying layers can be computed pixel by pixel. Automatically processing the columns with identical characteristics, 1D partially saturated flow and solute transport computations are performed. Different maps are obtained for the three above mentioned factors. On the basis of these results, different vulnerability maps can be built according to the weighting coefficients agreed by the local community or decision makers. This concept allows a clear distinction between conventional aspects and process-based results in the building of a final vulnerability indicator. This methodology has the further advantage to consider the possible impact of runoff conditions occurring at the land surface and possibly leading to lateral contamination of groundwater through downstream preferential infiltration features. To solve this problem, Popescu et al. (2004 & 2008) and Dassargues et al. (2009) proposed a method for quantifying a lateral “dangerosity” coefficient using runoff coefficients based on land use, slopes, and soil properties. A test application is illustrated on a case-study located in a limestone basin in Belgium. [less ▲]

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See detailPropagation of uncertainties in the modelling of MEMS resonators (using a 3-scale probabilistic approach)
Lucas, Vincent ULg; Wu, Ling ULg; Golinval, Jean-Claude ULg et al

Conference (2015, May 26)

In order to ensure the accuracy of MEMS vibrometers, the first resonance frequency should be predicted at the design phase. However, this prediction is subjected to randomness: there is a scatter in the ... [more ▼]

In order to ensure the accuracy of MEMS vibrometers, the first resonance frequency should be predicted at the design phase. However, this prediction is subjected to randomness: there is a scatter in the reached value resulting from the uncertainties involved in the manufacturing process. The purpose of this work is to take into account these uncertainties of the microstructure. The objective is a non-deterministic model that can be used since the design stage. The material is the source of uncertainties: the beam resonator is made of a polycrystalline material in which each grain has a random orientation. Solving the problem with a full direct numerical simulation combined to a Monte-Carlo method allows the probability density function of the resonance frequency to be computed. However this methodology is computationally expensive due to the number of degrees of freedom required to study one sample, motivating the development of a computationally efficient method. Towards this end a 3-scales stochastic model for predicting the resonance frequency of a micro-beam made of a polycrystalline linear anisotropic material is described. At the lower scale, we model the micro-structure with micro-volume elements. Due to the small-scale involved, the representativity of these micro-volume elements is not achieved and thus Statistical Volume Elements (SVE) are considered. These SVEs are generated under the form of a Voronoï tessellation, each grain being assigned a random orientation. Computational homogenization is applied over the SVEs, along with a Monte-Carlo procedure, to obtain a stochastic characterization of the elasticity tensor at the second scale of interest, the meso-scale. The spatial correlation between SVEs is also estimated. A generator based on spectral methods is implemented. Afterwards, using a stochastic finite element method, these meso-scale uncertainties are propagated by taking account of the spatial correlation up to the higher scale to predict the probabilistic behavior of the MEMS resonator. [less ▲]

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See detailDe la spécification à la création de nouvelles catégorisations sociales: Le cas de francophones vivant en Flandre et de néerlandophones vivant en Wallonie
Dassargues, Alix ULg

Conference (2015, May 26)

Nos recherches doctorales visent à étudier la manière dont des individus en situation d’allophonie « illégitime » se catégorisent socialement. Puisqu’aucune catégorie identitaire légitime (c.-à-d ... [more ▼]

Nos recherches doctorales visent à étudier la manière dont des individus en situation d’allophonie « illégitime » se catégorisent socialement. Puisqu’aucune catégorie identitaire légitime (c.-à-d. institutionnalisée par les dictionnaires, les médias, les politiciens ou autres instances légitimatrices (Bourdieu 1982)) ne rend compte de la situation de francophones vivant en Flandre (région belge unilingue néerlandophone) et de néerlandophones vivant en Wallonie (région belge unilingue francophone excepté une petite communauté germanophone institutionnellement reconnue et territorialisée), ces individus conceptualisent le champ social de façon originale afin qu’il corresponde à leurs propres expériences de vie (Harder 2010 : 18). En se basant sur des principes tels que la légitimité d’un lexème dans l’espace discursif ou encore le caractère idiolectal ou non d’une catégorisation, nous nous proposons d’observer les modes de conceptualisation de l’identité par des locuteurs particulièrement aptes à formuler des catégorisations originales du champ social puisque leurs expériences de vie ne font pas l’objet de catégorisations légitimes. À partir de transcriptions d’entretiens semi-directifs, nous avons examiné le discours de témoins afin d’analyser leurs conceptualisations du champ social à travers les catégorisations qu’ils emploient. Nous prenons en compte les catégories légitimes et illégitimes citées dans les témoignages selon leur institutionnalisation (présence ou non dans les dictionnaires et dans les discours médiatiques) et la manière dont elles sont considérées par les locuteurs (catégorie considérée comme légitime ou non par les locuteurs). De la sorte, une typologie de nouvelles catégorisations identitaires a pu être établie sur la base d’une analyse linguistique : spécification d’un lexème légitime par une proposition relative , spécification d’un signifié par un redoublement de certains signifiants légitimes , spécification d’un signifié par l’instauration d’une gradation dans l’adéquation avec une catégorie légitime (stéréotype institutionnalisé) , modifications de signifiés dans des catégorisations légitimes , création de nouvelles catégorisations à partir d’adjectifs et de lexèmes légitimes , création de métaphores en transposant l’expérience d’un domaine conceptuel des catégories sociales (cf. Lakoff & Johnson 1980). Cette recherche interdisciplinaire suggère que la construction de sens s’établit à partir d’autres connaissances déjà organisées entre elles (Harder 2010:113) et partagées par une communauté d’individus. En choisissant le thème ambitieux de l’identification (ou la catégorisation) de soi et des autres, cette recherche permet également de transposer les connaissances de la linguistique cognitive au domaine social. Ainsi, elle confirme notamment que le modèle sémantique basé sur un prototype (Rosch 1978; Lakoff 1987) est adéquat pour rendre compte de la construction individuelle du sens dans le champ social. [less ▲]

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See detailA stochastic multiscale analysis for MEMS stiction failure
Hoang Truong, Vinh ULg; Wu, Ling ULg; Golinval, Jean-Claude ULg et al

Conference (2015, May 26)

Stiction is a major failure in microelectromechanical system (MEMS) devices in which two contacting surfaces can remain stuck together because of the adhesive forces, such as van der Waals forces and ... [more ▼]

Stiction is a major failure in microelectromechanical system (MEMS) devices in which two contacting surfaces can remain stuck together because of the adhesive forces, such as van der Waals forces and capillary forces. Stiction is a multiscale problem which is characterized by three different lengths: the MEMS device characteristic length, the roughness of the contacting surfaces, and the distance range of the adhesive forces. Because MEMS surfaces roughness and adhesive force distances are of comparable scales, the randomness in the contacting surfaces can result in important uncertainties on the interacting forces, and in turn lead to a scatter in the MEMS structural behavior. The purpose of this work is to quantify the uncertainties on the macro stiction behavior of a MEMS structure due to the randomness in its contacting surfaces. A full analysis, such as the combination of a Monte-Carlo simulation to generate random surfaces combined with finite element (FE) analyses to model the stiction behavior, is expensive in terms of the computational cost due to the difference in the scales between the macro characteristic length and the distance range of the adhesive forces. Thus, in this work, we develop a stochastic multiscale analysis. At the micro scale, the uncertainties in the interacting forces between two rough surfaces are investigated. The power spectral density function of the surface is characterized from experimental topology measurements, and interacting surfaces are then generated as Gaussian random surfaces. For each generated random surface, the interacting adhesive forces are calculated by using a modified Dejarguin-Muller-Toporov (DMT) model. The resulting adhesive contact forces can be integrated using the finite element method at the structural scale by associating to each discretized contacting point a sampled surface. We then use the Monte-Carlo method to quantify the uncertainties in the stiction behavior of the MEMS device. [less ▲]

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