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See detailThe search for a core functionality network in chondrocyte differentiation using heuristic and genetic algorithms
Kerkhofs, Johan ULg

Conference (2014, June 18)

Introduction: In the growth plate a continuing process where cartilage is replaced by bone provides the fuel for bone growth until its closure towards the end of puberty. At the cellular level the growth ... [more ▼]

Introduction: In the growth plate a continuing process where cartilage is replaced by bone provides the fuel for bone growth until its closure towards the end of puberty. At the cellular level the growth rate is maintained by proliferation and enlargement of maturing cells (hypertrophy). Mature cartilage cells (hypertrophic chondrocytes) secrete Ihh, a growth factor that induces expression of PTHrP, another growth factor, in immature proliferating chondrocytes. Since PTHrP in turn inhibits chondrocyte maturation, Ihh secretion limits the number of maturing chondrocytes through a negative feedback loop, striking a balance between proliferation and hypertrophy [Kronenberg, 2003]. Materials and methods: A gene network centering on the control of Ihh, PTHrP and transcription factors Sox9 and Runx2, which are the master regulators of early and late chondrocyte differentiation respectively, was manually constructed from literature. The dynamics of this network are simulated in a discrete framework that divides reactions into two speed classes. In this framework all interactions are considered additive, and each interaction is associated with a weight. Starting from the observation that the gene network must activate Runx2 in the presence of Ihh and Sox9 in the presence of Ihh and PTHrP, we investigate which edges are vital in achieving this. To this end, we employ both a heuristic and a genetic algorithm where the weights attached to the edges function as variables. In the heuristic algorithm weights are uniformly distributed in [0,1] and the means (based on 450 samples) of the weights that satisfy the above mentioned observations are contrasted with those that do not. If the difference of the means passes a certain threshold, the weight of the corresponding edge is fixed at 1. Results and discussion: Preliminary results from the heuristic algorithm show that fixing 14 weights (out of 147) is sufficient to match the biological observations in about 22% of cases, all other weights being selected randomly. The selected edges show that the BMP pathway is crucial in effecting a switch between hypertrophy in the absence of PTHrP and proliferation in its presence. This observation can be substantiated by earlier findings that BMP signalling plays a crucial role in prehypertrophic cells that are on the verge of hypertrophy [Yoon, 2006]. References: Kronenberg, 2003, Nature, 423:332-336; Yoon et al., 2006, Development, 133:4667-4678. [less ▲]

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See detailLes univers vidéoludiques : des fictions mobiles et jouables
Barnabé, Fanny ULg

Poster (2014, June 18)

La question de la fiction constitue, depuis le début des années 2000, une clef d’entrée privilégiée pour étudier le médium vidéoludique. La capacité du jeu vidéo à prendre en charge la représentation ... [more ▼]

La question de la fiction constitue, depuis le début des années 2000, une clef d’entrée privilégiée pour étudier le médium vidéoludique. La capacité du jeu vidéo à prendre en charge la représentation d’une histoire par ses propres moyens (et non en empruntant ceux de la littérature ou du cinéma) a été tantôt affirmée (Ryan, 2003 ; Murray, 1998), tantôt contestée (Frasca, 1999 ; Juul, 2001 ; Eskelinen, 2001). Dès lors – même si les oppositions à son sujet sont aujourd’hui plus nuancées – elle demeure un objet problématique dont le traitement entraîne souvent d’importants détours théoriques. Les concepts de la narratologie « traditionnelle » (tels que celui d’un récit clos et prédéfini ou d’une narration « unidirectionnelle ») semblent a priori peu compatibles avec les impératifs d’interaction et de jouabilité qui sont au cœur de l’expérience vidéoludique. Quels outils adopter, en conséquence, pour décrire ce qui advient de la fiction lorsqu’elle est prise en charge par le jeu ? C’est à cette question que nous tâcherons de répondre en définissant les contours d’une notion souvent évoquée par la recherche, mais peu théorisée : celle d’« univers fictionnel ». Pour ce faire, nous nous nourrirons tant des avancées des games studies et des « play studies » (Triclot, 2011) que des théories de la fiction (Schaeffer, 1999) et de ses modes actuels de consommation par les amateurs (Jenkins, 2006). La distinction opérée par Amato (2005) entre les notions de cosmos, de diégèse et de ludiégèse permettra également de préciser la définition de ce qu’est un univers lorsqu’il est régi par le jeu. En effet, la narrativité propre au jeu vidéo ne semble pas répondre à la logique linéaire du récit : une grande part de l’histoire n’est généralement présente que de manière « latente » (Letourneux, 2005) dans une série d’éléments hétérogènes (le texte, l’interface, les décors, les sons, les objets…), situés à différents niveaux de l’œuvre et dont le sens narratif peut ou non être activé par le joueur (Guardiola, 2005 parle, à ce titre, de la dimension « permissive » du jeu vidéo). Pour décrire cette pluri-dimensionnalité et cette dispersion de l’histoire au sein d’« éléments de narrativisation » (Genvo, 2002), la notion de récit apparaît comme réductrice. À l’inverse, celle d’univers (définie dès lors comme un agencement d’éléments non hiérarchisés et éventuellement porteurs d’une narrativité latente) présente une forte opérationnalité, due principalement à deux de ses caractéristiques : son ouverture et sa nature modulable. Son ouverture, tout d’abord, car elle permet non seulement de prendre en compte l’ensemble des composantes de la fiction qui sont internes à l’œuvre vidéoludique, mais aussi celles qui lui sont externes (qu’il s’agisse du paratexte, des livrets des jeux, des bandes annonces,… ou encore de véritables développements narratifs autonomes, réalisés sur différents médias). Sa malléabilité, ensuite, car le concept d’univers, contrairement à celui de narration, admet l’interactivité : c’est le joueur qui actualise le récit (il participe à son énonciation) et qui, par la continuité de sa présence, organise les « éléments de narrativisation » en une configuration cohérente. En outre, concevoir la fiction comme un agencement de diverses composantes permet d’envisager les constantes évolutions que lui font subir les communautés d’amateurs : ceux-ci, en confrontant leurs représentations, développent par exemple des modèles collectifs « non officiels » (les « fanons » ; voir Hellekson et Busse, 2006) qui ont un impact certain sur la vie des fictions. L’univers fictionnel constitue, en somme, un outil théorique porteur qui rend possible la description des points de passage entre jeu et fiction et l’évaluation des contraintes que l’un exerce sur l’autre. Toutefois, bien qu’il ait initialement été élaboré pour correspondre au domaine spécifique du jeu vidéo, le concept semble déborder de ces premiers questionnements et s’adapter, plus généralement, à l’étude des modes actuels de production et de consommation de la fiction. En effet, son ouverture invite, d’une part, à élargir la conception traditionnelle de la narration et à l’envisager comme un ensemble transmédiatique. D’autre part, sa nature d’agencement n’est pas sans rappeler les théories d’Azuma (2008) selon lesquelles les fictions postmodernes ne sont plus considérées comme des unités finies et fermées, mais comme des agencements qui puisent dans un fonds commun, une « base de données » perpétuellement renouvelée. Chaque élément investi par la fiction intègre ce fonds commun et devient alors susceptible de connaître des continuations, des réappropriations, des réagencements. Les histoires conçues sur ce mode ne sont pas lues, mais vécues et explorées : la lecture devient une expérience et une expérimentation. [less ▲]

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See detailThe potentiality of PDMAEMA-based polycation for cardiovascular applications
Flebus, Luca ULg; Lombart, François ULg; Martinez, Lucia et al

Conference (2014, June 18)

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See detailSolar simulation test up to 13 solar constants for the thermal balance of the Solar Orbiter EUI instrument
Rossi, Laurence ULg; zhukova, Maria; Jacques, Lionel ULg et al

in Proceedings of SPIE (2014, June 18)

Solar Orbiter EUI instrument was submitted to a high solar flux to correlate the thermal model of the instrument. EUI, the Extreme Ultraviolet Imager, is developed by a European consortium led by the ... [more ▼]

Solar Orbiter EUI instrument was submitted to a high solar flux to correlate the thermal model of the instrument. EUI, the Extreme Ultraviolet Imager, is developed by a European consortium led by the Centre Spatial de Liège for the Solar Orbiter ESA M-class mission. The solar flux that it shall have to withstand will be as high as 13 solar constants when the spacecraft reaches its 0.28AU perihelion. It is essential to verify the thermal design of the instrument, especially the heat evacuation property and to assess the thermo-mechanical behavior of the instrument when submitted to high thermal load. Therefore, a thermal balance test under 13 solar constants was performed on the first model of EUI, the Structural and Thermal Model. The optical analyses and experiments performed to characterize accurately the thermal and divergence parameters of the flux are presented; the set-up of the test, and the correlation with the thermal model performed to deduce the unknown thermal parameters of the instrument and assess its temperature profile under real flight conditions are also presented. [less ▲]

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See detailSpace radiation parameters for EUI and the Sun Sensor of Solar Orbiter, ESIO and JUDE instruments
Rossi, Laurence ULg; Jacques, Lionel ULg; Halain, Jean-Philippe ULg et al

in Proceedings of SPIE (2014, June 18)

This paper presents predictions of space radiation parameters for four space instruments performed by the Centre Spatial de Liège (ULg – Belgium); EUI, the Extreme Ultra-violet Instrument, on-board the ... [more ▼]

This paper presents predictions of space radiation parameters for four space instruments performed by the Centre Spatial de Liège (ULg – Belgium); EUI, the Extreme Ultra-violet Instrument, on-board the Solar Orbiter platform; ESIO, Extreme-UV solar Imager for Operations, and JUDE, the Jupiter system Ultraviolet Dynamics Experiment, which was proposed for the JUICE platform. For Solar Orbiter platform, the radiation environment is defined by ESA environmental specification and the determination of the parameters is done through ray-trace analyses inside the EUI instrument. For ESIO instrument, the radiation environment of the geostationary orbit is defined through simulations of the trapped particles flux, the energetic solar protons flux and the galactic cosmic rays flux, taking the ECSS standard for space environment as a guideline. Then ray-trace analyses inside the instrument are performed to predict the particles fluxes at the level of the most radiation-sensitive elements of the instrument. For JUICE, the spacecraft trajectory is built from ephemeris files provided by ESA and the radiation environment is modeled through simulations by JOSE (Jovian Specification Environment model) then ray-trace analyses inside the instrument are performed to predict the particles fluxes at the level of the most radiation-sensitive elements of the instrument. [less ▲]

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See detailUsing a rich internet application to teach histology
Quatresooz, Pascale ULg; Defaweux, Valérie ULg; Rollus, L et al

Conference (2014, June 18)

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See detailComment gérer la nutrition artificielle chez un patient diabétique ?
PAQUOT, Nicolas ULg; DE FLINES, Jenny ULg; Preiser, Jean-Charles

in Nutrition Clinique et Metabolisme (2014)

Hyperglycaemia in patients receiving enteral or parenteral nutrition is a major problem due to its high prevalence and possible consequences interms of morbidity and mortality. However, the management of ... [more ▼]

Hyperglycaemia in patients receiving enteral or parenteral nutrition is a major problem due to its high prevalence and possible consequences interms of morbidity and mortality. However, the management of diabetes/stress hyperglycaemia during artificial nutrition remains largely unknown,especially in non-critically ill patients. The indications and access routes for artificial nutrition are not different in patients with diabetes/stressdiabetes than in non-diabetics. We do not recommend using enteral formulas designed for patients with diabetes. The glycaemic objective mustbe individualized. We recommend a preprandial blood glucose levels between 100 and 140 mg/dL (5.5 and 7.8 mmol/L) and postprandial levelsbetween 140 and 180 mg/dL (7.8 and 10 mmol/L). A frequent monitoring of capillary glycaemias is mandatory. The best drug treatment for treatinghyperglycaemia/diabetes is insulin and we recommend to adapt the theoretical insulin action to the nutrition infusion regimen. The managementof these patients needs the help of a multidisciplinary experimented staff. [less ▲]

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See detailLes approches sémiotiques du portrait photographique. De l’identité à l’“air”
Dondero, Maria Giulia ULg

in COnTEXTES : Revue de Sociologie de la Littérature (2014, June 18), 14

L’objectif de cet article est d’abord méthodologique : il entend déployer les instruments de l’analyse sémiotique, et notamment énonciative et temporelle, des images photographiques. Ensuite, il vise à ... [more ▼]

L’objectif de cet article est d’abord méthodologique : il entend déployer les instruments de l’analyse sémiotique, et notamment énonciative et temporelle, des images photographiques. Ensuite, il vise à esquisser la spécificité du genre du portrait et à interroger l’identification de caractéristiques singularisant le portrait d’écrivain. [less ▲]

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See detailAssessment of Solvent Degradation within a Global Process Model of Post-Combustion CO2 Capture
Léonard, Grégoire ULg; Heyen, Georges ULg; Toye, Dominique ULg

Conference (2014, June 17)

Solvent degradation may be a major drawback for the large-scale implementation of post-combustion CO2 capture due to amine consumption and emission of degradation products. However, its influence on the ... [more ▼]

Solvent degradation may be a major drawback for the large-scale implementation of post-combustion CO2 capture due to amine consumption and emission of degradation products. However, its influence on the process operations has rarely been studied. In the present work, a kinetics model describing solvent oxidative and thermal degradation has been developed based on own experimental results for the benchmark solvent, i.e. 30 wt% monoethanolamine (MEA) in water. This model has been included into a global Aspen Plus model of the CO2 capture process. The selected process modelling approaches are described in the present work. Using the resulting simulation model, optimal operating conditions can be identified to minimize both the energy requirement and the solvent degradation in the process. This kind of process model assessing solvent degradation may contribute to the design of large-scale CO2 capture plants to consider not only the process energy penalty, but also its environmental penalty. Indeed, both aspects are relevant for the large-scale deployment of the CO2 capture technology. [less ▲]

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See detailThe Science Behind the Illusion of Life
Collignon, Stéphane ULg

Conference (2014, June 17)

Brève revue des différents processus cognitifs et neuroscientifiques qui permettent d'expliquer qu'une figurine de cartoon suscite de réelles émotions malgré son artificialité manifeste.

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See detailPrior light history impacts on higher order cognitive brain function
Chellappa, Sarah Laxhmi ULg; Ly, Julien; Meyer, Christelle ULg et al

Conference (2014, June 17)

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See detailInfusion of clinical-grade enriched regulatory T cells delays experimental xenogeneic graft-versus-host disease
Hannon, Muriel ULg; LECHANTEUR, Chantal ULg; Lucas, Sophie et al

in Transfusion (2014), 54(February), 353-363

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See detailPolyester-based microcarriers with enhanced surface properties for tissue engineering
Markvicheva, Elena; Privalova, Anna; Sevrin, Chantal ULg et al

Poster (2014, June 17)

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See detailIN VITRO STUDY OF A FIBER NETWORK TAILORED AS 3D-CELL MODEL
Sevrin, Chantal ULg; Lombart, François ULg; Godino, Miguel et al

Poster (2014, June 17)

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See detailAdolescent male sexual offenders: pubertal timing, psychosocial functioning and sexual abuse: what links?
Glowacz, Fabienne ULg

Conference (2014, June 17)

The impact of pubertal development on the psychological and social functioning of the teenager arouses a particular interest; the most recent research shows the existence of complex relationships between ... [more ▼]

The impact of pubertal development on the psychological and social functioning of the teenager arouses a particular interest; the most recent research shows the existence of complex relationships between pubertal development and the manifestation of internalized and externalized disorders. According to a biosocial model, biological and social factors interact in their influence on sexual behavior. A number of studies have shown that sexual activity is associated with pubertal timing. Our study is interested specifically in the links between sexual activity (and sexual abuse) during adolescence and pubertal maturation in a population of juvenile sexual offenders aged between 12 and 18 years. We measured the pubertal variable starting from the perceived pubertal timing (PPT), which evaluates the teenagers' perception of their pubertal maturation, compared with that of their peers, to understand its impact on various dimensions of the functioning of teenagers: the perception of self , aggressiveness, association with peers, self-revealed delinquency and sexual offenses. Two predominant hypothesis are used for explain influence of pubertal timing on sexual offense: the maturational deviance hypothesis and the early timing hypothesis. Our results confirm the importance of integrating the puberty variable into research on adolescent male sexual offenders, but also at the level of intervention. [less ▲]

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See detailIslamic religion and food practices in migration context: negotiating belonging and performing subjectivities
Mescoli, Elsa ULg

Conference (2014, June 17)

My paper focuses on the ethnographic material collected during a doctoral research around the culinary practices of Moroccan women living in the city of Sesto San Giovanni (in Milan hinterland, Italy). In ... [more ▼]

My paper focuses on the ethnographic material collected during a doctoral research around the culinary practices of Moroccan women living in the city of Sesto San Giovanni (in Milan hinterland, Italy). In particular, adopting a praxeological approach to subjectivation (Warnier 2001), I will highlight those aspects of the materiality that I studied which recall the belonging of the considered women to Islamic religion. In fact, everyday food consumption (or that related to specific events) and the very same preparation of recipes, are influenced not only by the prescriptions concerning licit and illicit food, but also by the suggestions regarding food which are appropriate to eat. On the one hand, Islamic norms prohibit some food to believers, such as certain meats because of the animal species or the category of victims (Benkheira 1997) to which they belong. Nevertheless, Muslim women behaviours concerning meat consumption are various, such as those of my informants, who in some cases demonstrate to negotiate such norms in order to materially shape a specific self interacting with different collective belongings. On the other hand, some Quranic verses and some sayings of the prophet Muhammad, define a soul food (Rouse and Hoskin 2004), by suggesting to believers what to eat to perform their piety: the preparation and the consumption of some food – and not only the abstention from it – finds in fact religious reasons. In order to follow such suggestions, in a context where Islamic religion is not the majority one, women has to deal with local rules while performing the materiality of some rituals. Religion and traditions intertwine and they shape specific knowledge and savoir-faire which are negotiated by the women considered so as to affirm their various belongings and to face the constraints which the new lived context imposes to them. Such constraints oblige a form of reflexivity on religious norms and rites (Højbjerg 2002), in order to define a limit beyond which modifications are perceived as subtractions of sense (Dore 2001). In my paper, I will try to give some ethnographic examples of these forms of reflexivity and to show how these dynamics constitute the materiality upon which and with which the women considered define their subjectivity. To support my reflexions, I will use visual materials such as photos and videos, which will witness the material density of these facts. [less ▲]

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See detail"Je ne suis pas philosophe." Rousseau au miroir de l'épistolaire. Images de soi dans la correspondance de Jean-Jacques Rousseau (1730-1765)
Biquet, Stéphanie ULg

Doctoral thesis (2014)

L’objet de cette recherche consiste donc en une analyse de l’image de soi dans le discours épistolaire de Jean-Jacques Rousseau, depuis les premières années genevoises (vers 1730) jusqu’au départ pour ... [more ▼]

L’objet de cette recherche consiste donc en une analyse de l’image de soi dans le discours épistolaire de Jean-Jacques Rousseau, depuis les premières années genevoises (vers 1730) jusqu’au départ pour l’Angleterre (1765). Plus précisément, nous avons examiné le rapport que cette image entretient avec la figure du philosophe, qui fait l’objet d’une profonde reconfiguration au cours du XVIIIe siècle et qui nous semble une clé de lecture incontournable pour comprendre Rousseau. [less ▲]

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