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See detailDevelopment of a multiplexed surface-enhanced Raman scattering quantitative approach for bisphenols detection
De Bleye, Charlotte ULg; Dumont, Elodie ULg; Sacre, Pierre-Yves ULg et al

Conference (2014, June 23)

Over the last decade, bisphenol A (BPA) attracted a lot of attention. This molecule, commonly used as a precursor to produce epoxy-resin and plastics, is an endocrine disruptor presenting an estrogenic ... [more ▼]

Over the last decade, bisphenol A (BPA) attracted a lot of attention. This molecule, commonly used as a precursor to produce epoxy-resin and plastics, is an endocrine disruptor presenting an estrogenic activity [1]. Despite its health toxicity, BPA is present in a broad variety of consumer goods released from plastic bottles and packaging for example. Since the discovery of its adverse health effect of BPA, the manufacturers tend to use structural analogues of BPA such as BPS, BPF and BPB to produce plastic materials [2]. However, the health safety of these molecules is still not demonstrated. Currently, bisphenols are actively researched and quantified using solid phase extraction and chromatography techniques which are time and solvents consuming. Therefore, it could be very interesting to quantify simultaneously bisphenols using a fast and “green” technique. Surface-enhanced Raman scattering (SERS) exalts dramatically the Raman scattering of molecules adsorbed or very closed to metallic surface enabling to detect very low amounts of analytes while keeping the structural information obtained from the spectrum which is very interesting to consider multiplexed analyses [3-4]. Moreover, SERS, which is a solvent free and fast acquisition technique, is an attractive tool in “Green Chemistry” [5]. In this context, the development of a multiplexed quantitative approach to detect bisphenol was considered. Silver nanoparticles (AgNps) were selected as SERS substrate and their functionalization was investigated taking into account the weak affinity of phenolic molecules for gold and silver surface [6]. Pyridine was selected as surface modifier and allowed to attract bisphenols around metallic surface thanks to hydrophobic interaction and hydrogen bonds [7]. Afterwards, the SERS samples preparation was optimized playing on the concentrations of pyridine and aggregating agent used to get the nanoparticles closer to each other which promotes the SERS effect. Tap water samples were spiked with different concentration of BPA from 5 ppb to 1000 ppb and analyzed using the optimized SERS sample preparation. A good linearity of the response was observed and a calibration curve with coefficient of determination (R2) of 0.9922 was obtained by plotting the intensity of a principal band of BPA versus the concentration. This last step was repeated using BPB as analyte and a calibration curve with a R2 of 0.9991 was obtained for the same range of concentration using a specific band intensity of BPB. Finally, tap water samples were spiked with different concentrations of BPA and BPB simultaneously and analyzed using SERS and it was possible to detect selectively the two molecules thanks to specific bands and a good linearity of the response was observed for both. To conclude, promising results were obtained which pave the way to “green” multiplexed quantitative analyses of very low concentrated analytes using SERS. References: [1] J.-H. Kang et al., Toxicology 226 (2006) 79-89 [2] C. Liao et al., J. Agric. Food Chem. 61 (2013) 4655-4662 [3] K. Kneipp et al., Chem. Rev. 99 (1999) 2957-2975. [4] R.F. Aroca et al., Adv.Colloid Interface Sci. 116 (2005) 45-61. [5] C. De Bleye et al., Talanta 116 (2013) 899-905. [6] X.X. Han et al., Anal. Chem., 83 (2011) 8582-8588. [7] B. San Vicente et al., Anal. Bioanal. Chem. 380 (2004) 115-122. [less ▲]

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See detailGeneration of artificial magnetic fields using dipole-dipole interactions
Cesa, Alexandre ULg; Martin, John ULg

Poster (2014, June 23)

In 1996, Lloyd [1] showed that the dynamics of complex many-body quantum systems can be efficiently simulated by quantum computers, an idea first put forward by Manin [2] and further developed by Feynman ... [more ▼]

In 1996, Lloyd [1] showed that the dynamics of complex many-body quantum systems can be efficiently simulated by quantum computers, an idea first put forward by Manin [2] and further developed by Feynman [3]. Although the first quantum computers of a few qubits have been realised experimentally [4, 5], the advent of scalable quantum computers might take another few decades. An alternative tool in the context of simulation is a highly controllable quantum system able to mimic the dynamics of other complex quantum systems, known as an analog quantum simulator. Cold neutral atoms and trapped ions have been shown to be versatile quantum simulators [6, 7] thanks to their high flexibility, controllability, and scalability. They permit one to study a wide range of problems arising from atomic physics, relativistic quantum physics, or cosmology [8]. Since neutral atoms do not carry any net charge, the simulation of electric and magnetic condensed matter phenomena, such as the spin Hall effect, seems out of reach. To overcome this apparent difficulty, the idea has been proposed to create artificial electromagnetic potentials for neutral atoms based on atom-light interaction [9– 12]. These artificial potentials act on neutral atoms as real electromagnetic potentials act on charged particles. Many works on artificial gauge potentials induced by atom-light interactions adopt a single-particle approach [12]. The predicted potentials are then supposed to be valid for a system of weakly interacting atoms. So far, the consequences of atom-atom interactions on the generation of artificial gauge fields has little been studied. The aim of this work is to study the artificial gauge fields arising from the interaction of two Rydberg atoms driven by a common laser field [13]. In this situation, we show that the combined atom-atom and atom-field interactions give rise to nonuniform, artificial gauge potentials. We identify the mechanism responsible for the emergence of these gauge potentials. Analytical expressions for the latter indicate that the strongest artificial magnetic fields are reached in the regime intermediate between the dipole blockade regime and the regime in which the atoms are sufficiently far apart such that atom-light interaction dominates over atom-atom interactions. We discuss the differences and similarities of artificial gauge fields originating from resonant dipole-dipole [14] and van der Waals [15] interactions. We also give an estimation of experimentally attainable artificial magnetic fields resulting from this mechanism and we discuss their detection through the deflection of the atomic motion. [1] S. Lloyd, Science 273, 1073 (1996). [2] Yu. I. Manin, Computable and uncomputable, Sovetskoye Radio, Moscow, 1980. [3] R. P. Feynman, Int. J. Theor. Phys. 21, 467 (1982). [4] L. DiCarlo, J. M. Chow, J. M. Gambetta, Lev S. Bishop, B. R. Johnson, D. I. Schuster, J. Majer, A. Blais, L. Frunzio, S. M. Girvin, and R. J. Schoelkopf, Nature 460, 240 (2009). [5] N. Xu, J. Zhu, D. Lu, X. Zhou, X. Peng, and J. Du, Phys. Rev. Lett. 108, 130501 (2012). [6] I. Buluta and F. Nori, Science 326, 108 (2009). [7] I. Bloch, J. Dalibard and S. Nascimbéne, Nature Physics 8, 267 (2012). [8] R. Blatt and C. F. Roos, Nature Physics 8, 277 (2012). [9] G. Juzeliunas and P. Öhberg, Phys. Rev. Lett. 93, 033602 (2004). [10] G. Juzeliunas, P. Öhberg, J. Ruseckas, and A. Klein, Phys. Rev. A 71, 053614 (2005). [11] G. Juzeliunas, J. Ruseckas, P. Öhberg, and M. Fleischhauer, Phys. Rev. A 73, 025602 (2006). [12] J. Dalibard, F. Gerbier, G. Juzeliu ̄nas, and P. Öhberg, Rev. Mod. Phys. 83, 1523 (2011). [13] A. Cesa and J. Martin, Phys. Rev. A 88,062703 (2013). [14] A. Gaëtan, Y. Miroshnychenko, T. Wilk, A. Chotia, M. Viteau, D. Comparat, P. Pillet, A. Browaeys, and P. Grangier, Nature Physics 5, 115 (2009). [15] L. Béguin, A. Vernier, R. Chicireanu, T. Lahaye, and A. Browaeys, Phys. Rev. Lett. 110, 263201 (2013). [less ▲]

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See detailNMR in the Pharmaceutical and Biomedical areas for identification and quantification of drugs and metabolomics applications
LAMBERT, Vincent ULg; Dufour, Gilles ULg; Chiap, Patrice ULg et al

Conference (2014, June 23)

Nuclear Magnetic Resonance (NMR) is probably, with mass spectrometry, the most powerful analytical tool for the structural determination of organic compounds. For a long time and due to technical ... [more ▼]

Nuclear Magnetic Resonance (NMR) is probably, with mass spectrometry, the most powerful analytical tool for the structural determination of organic compounds. For a long time and due to technical limitations, the main applications of NMR were focused on chemistry (organic, inorganic and medicinal chemistry) or biochemistry (i.e. proteins and proteins ligands analysis). Indeed, despite of very interesting potential in terms of structural information, reproducibility, specificity, quantification, NMR suffered of a lack of sensitivity and sometime of resolution in the case of complex mixture analysis in comparison with other technics. However, since several years, important technical improvements such as huge increase in sensitivity, hyphenation of NMR with LC system, automation and development of 2D and presaturation sequences have opened new putative applications for NMR, specifically in the pharmaceutical and biomedical areas. Then, beside the mass and chromatographic technics classically used for drug analysis, NMR represents an interesting and complementary tool for many applications. In this presentation, we will describe some NMR applications related to the pharma area. Starting from the identification of xenobiotic metabolites by coupling LC-SPE-NMR data with LC-MS/MS results, quantification of cyclodextrines in complex media, identification of illicit compounds, we will finish with our recent metabolomics NMR developments. [less ▲]

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See detailEvaluation of SFC interest for the determination of cholecalciferol and its impurities un pharmaceuticals
Andri, Bertyl ULg; Dispas, Amandine ULg; Klinkenberg, Régis et al

Poster (2014, June 23)

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See detailSymmetric N-qubit anticoherent states
Baguette, Dorian ULg; Bastin, Thierry ULg; Martin, John ULg

Poster (2014, June 23)

Entanglement is among the key features of quantum mechanics. In the last decade, a lot of efforts has been made to quantify the amount of entanglement of various multipartite states, either pure or mixed ... [more ▼]

Entanglement is among the key features of quantum mechanics. In the last decade, a lot of efforts has been made to quantify the amount of entanglement of various multipartite states, either pure or mixed. In particular, the search for maximally entangled states (states maximizing certain measures of entanglement) has focused a great deal of attention, see e.g. Refs. [1–4]. In this work, we present a comprehensive study of maximally entangled symmetric N-qubit states with respect to the definition of Gisin [1]. According to this definition, a state is maximally entangled if all its one-qubit reduced density matrices are maximally mixed. These states maximize various entanglement measures, such as von Neumann and Meyer-Wallach entropies [5]. They are unique up to local unitaries within the class of states interconvertible under stochastic local operations and classical communication (SLOCC) [3]. Besides, they are conjectured to be maximally entangled with respect to the Negative Partial Transpose measure of entanglement [6]. As appreciated by B. Kraus, they play an important role in the determination of the local unitary equivalence of multiqubit states [7]. Moreover, they are maximally fragile (in the sense that they are the states which are the most sensitive to noise) and therefore have been proposed as ideal candidates for ultrasensitive sensors [1]. We provide general conditions for a symmetric state with an arbitrary number of qubits to be maximally entangled and identify families of SLOCC classes which do not contain any such states. We also compute various measure of entanglement associated with those states in order to characterize them further and find all maximally entangled states up to 4 qubits. We finally prove that maximally entangled states coincide with anticoherent states of order 1. According to the definition of Ref. [8], a symmetric state of N qubits is anticoherent to order t iff 〈(S·n)k〉 is independent of n for k = 1, . . . , t where n is a tridimensional unit vector and S is the collective spin operator associated to the N-qubit system. [1] N. Gisin, H. Bechmann-Pasquinucci, Phys. Lett. A 246 (1998). [2] A. Higuchi, A. Sudbery, Phys. Lett. A, 272, 213 (2000). [3] F. Verstraete, J. Dehaene, B. De Moor, Phys. Rev. A 68, 012103 (2003). [4] J. Martin, O. Giraud, P. A. Braun, D. Braun and T. Bastin, Phys. Rev. A 81, 062347 (2010). [5] D. A. Meyer, N. R. Wallach, J. Math. Phys. 43, 4273 (2002). [6] I. D. K. Brown, S. Stepney, A. Sudbery, and S. L. Braunstein, J. Phys. A 38, 1119 (2005). [7] B. Kraus, Phys. Rev. Lett. 104, 020504 (2010). [8] J. Zimba, EJTP 3, 10 (2006). [less ▲]

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See detailAlteration of decoherence-free states caused by dipole-dipole interactions
Damanet, François ULg; Martin, John ULg

Poster (2014, June 23)

Decoherence, known as the consequence of the coupling of any quantum system to its environment, causes information loss in the system and represents a major problem in the physical realization of quantum ... [more ▼]

Decoherence, known as the consequence of the coupling of any quantum system to its environment, causes information loss in the system and represents a major problem in the physical realization of quantum computers [1]. Decoherence-Free States (DFS) are considered as a possible solution to this problem. A set of trapped cold atoms placed in a DFS state will be immune against decoherence due to spontaneous emission. However, because of dipole-dipole interactions between atoms, induced dephasing effects are likely to destroy the coherence and drive the system out of its DFS [1, 2]. In this work, we study numerically the dynamics of a set of two-level atoms initially in a DFS with respect to dissipative processes by solving the master equation including both dissipative dynamics and dipole dipole interactions. We fo- cus our attention on the infuence of dipolar coupling on the radiated energy rate and coherence of the system as in [3]. In particular, by averaging over many realizations of close randomly distributed atomic positions, we show the formation of a superradiant-like pulse and we study its properties as a function of the dipolar coupling strength. [1] D. A. Lidar & K. B. Whaley, Lectures Notes in Phys., Vol. 622, p83-120, Springer (2003). [2] M. Gross & S. Haroche, Physics reports 93, 301-396 (1982). [3] W. Feng, Y. Li & S-Y. Zhu, Phys. Rev. A 88, 033856 (2013). [less ▲]

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See detailMulti-period vehicle assignment with stochastic load availability
Pironet, Thierry ULg

Conference (2014, June 23)

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 evaluations of the probability distributions is also analyzed. [less ▲]

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See detailChemical abundances of fast-rotating OB stars
Cazorla, Constantin ULg; Morel, Thierry ULg; Nazé, Yaël ULg et al

Poster (2014, June 23)

Fast rotation in massive stars is predicted to induce mixing in their interior, but recent observations have challenged this concept by revealing a population of fast-rotating stars with normal nitrogen ... [more ▼]

Fast rotation in massive stars is predicted to induce mixing in their interior, but recent observations have challenged this concept by revealing a population of fast-rotating stars with normal nitrogen abundances at their surface (Hunter et al. 2009, A&A, 496, 841; Brott et al. 2011, A&A, 530, A116, but see Maeder et al. 2014, A&A, 565, A39). However, as the binary fraction of these stars is unknown, the importance of mass-transfer processes cannot be quantified. As a result, no definitive statements about the ability of single-star evolutionary models including rotation to reproduce these observations can be made. Our work combines for the first time a detailed surface abundance analysis with a radial-velocity monitoring for a sample of bright, fast-rotating Galactic OB stars to put strong constraints on stellar evolutionary and interior models. [less ▲]

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See detailLe français cadien, un français acadien? Enjeux sociaux d’une parenté linguistique
Arrighi, Laurence; Urbain, Emilie ULg

Conference (2014, June 20)

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See detailThe Belgian Tetris: assessing the political impact of metaphors on citizens' perceptions of Belgian federalism
Perrez, Julien ULg; Reuchamps, Min

Conference (2014, June 20)

In the literature, the political impact of metaphors has often been taken for granted from metaphor analysis in political discourse, be it elite discourse or media discourse. However, a more global ... [more ▼]

In the literature, the political impact of metaphors has often been taken for granted from metaphor analysis in political discourse, be it elite discourse or media discourse. However, a more global understanding of what this political impact could consist of, is still lacking from the current research agenda. As Koller (2009:121) puts it: “metaphor helps construct particular aspects of reality and reproduce (or subvert) dominant schemas.” To be able to account for how metaphors, through discourses, actively shape the political reality, it is important to look at the relationships between metaphorical discourses and their environment. Based on the idea that metaphors do not only reflect the perceived reality, but also function as cues through which citizens come to understand complex political processes and through which they shape political behaviors, the aim of this study is precisely to look at how specific metaphors might impact on the citizens’ framing of Belgian federalism. To measure the impact of metaphors on the citizens’ political representations and attitudes, we developed an experimental set-up based on an article published in the Belgian newspaper Le Soir (13-14 July 2013) in which Belgian federalism was deliberately compared to a Tetris game. The original article included a picture and a text (208 words), which were used as authentic experimental material. For this experiment, we distinguished three experimental conditions and one control condition. In the first experimental condition (full condition), the participants were exposed to the original article (including the text and the picture). In the second and third experimental conditions, the participants were respectively exposed either to the text (text condition) or the picture (picture condition). In the control condition, the participants weren’t exposed to any metaphorical material at all. In the second stage of the experiment, the participants were asked to achieve three interrelated tasks: (i) a free description task, based on a free description of their own perception of Belgian federalism, (ii) an association task, in which they had to select a picture which they found the most appropriate to describe Belgian federalism, and finally (iii) a questionnaire measuring the participants’ political knowledge of Belgian federalism and attitudes towards its future development. In a post-test held four weeks after the first experiment, the three tasks of the second stage have been replicated. This experiment has been conducted in autumn 2013 among 400 students. Comparing the various experimental conditions will make it possible (i) to measure the impact of the Tetris metaphor on the citizens’ perceptions and representations of Belgian federalism, (ii) to assess to what extent the different metaphorical media differently contribute to this impact and (iii) to measure the long-term impact of this metaphor on the citizens’ political representations and attitudes. In answering these questions, this study will contribute to a better understanding of the role and functions metaphors play in political discourse, and more globally in our everyday political interactions. [less ▲]

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See detailUn panorama du temps. Robida chroniqueur des Expositions universelles
Stienon, Valérie ULg

Conference (2014, June 19)

Robida est familier des Expositions universelles. Sa carrière de dessinateur-journaliste est en grande partie rythmée par les événements sociaux qu’elles constituent. Il illustre le démontage de ... [more ▼]

Robida est familier des Expositions universelles. Sa carrière de dessinateur-journaliste est en grande partie rythmée par les événements sociaux qu’elles constituent. Il illustre le démontage de l’Exposition de Paris de 1867 dans le Journal Amusant du 9 novembre 1867. Il est envoyé à Vienne comme dessinateur-correspondant du Monde illustré pour celle de 1873. Il visite l’Exposition de 1889 et en rend compte en double-page dans La Vie Parisienne du 11 mai 1889 (« Demandez, l’inauguration officielle de la Tour ! »). Enfin, il participe activement à l’Exposition de 1900 avec la reconstitution minutieuse, pendant près de deux ans, du « Vieux Paris », une attraction à succès située entre le Pont de l’Alma et la passerelle Debilly. En tant que manifestation très fréquentée, qui fait l’objet d’une abondante publicité et qui engage l’image d’une ville à dimension internationale, l’exposition dans ses diverses formes (universelle, internationale, industrielle) constitue un nouveau mode de communication et un lieu de sociabilité spécifique dans la seconde moitié du XIXe siècle. Le chroniqueur, le journaliste et le dessinateur sont amenés à commenter et à représenter ce type d’événement célébratif qui implique tout à la fois une esthétique de la monstration, une rhétorique publicitaire et une réflexivité patrimoniale sur le siècle. Lieu de présentation de l’innovation, animé par un imaginaire du progrès technique et industriel, l’exposition a pu ainsi constituer une matrice féconde pour l’œuvre d’anticipation de Robida. Cette communication propose d’examiner ce que la production de Robida doit aux discours et aux représentations liés aux Expositions universelles dans les deux décennies de 1880 et 1890. Des thématisations explicites, des visites fictives en mots et en images, ainsi qu’un abondant intertexte d’actualité témoignent de ce rapport à un discours social qui traverse une œuvre conjecturale ambiguë. Si les liens thématiques du Vingtième Siècle à l’Exposition Internationale d’Électricité de 1881 sont bien connus, il faut aussi envisager les aspects de la production de Robida qui impliquent le support journalistique. C’est le cas des dessins de presse qui préparent de manière critique la réception des Expositions, comme le montre la couverture de La Caricature du 16 juin 1886 faisant, trois ans à l’avance, l’éloge paradoxal du projet de métro aérien coupable d’encombrer le ciel parisien. C’est aussi le cas des inventions moquées dans sa correspondance fictive avec le dessinateur Christophe entre 1896 et 1901 dans « La Boîte aux lettres » du Petit Français illustré, où Robida-Théodule Asenbrouck imagine des machines telles que la « pince-scie-brosse-polissoir électrique » pour découper la Lune en douze tranches afin d’éclairer les grandes capitales, en particulier la Ville-Lumière. L’Exposition constitue également un cadre de transposition fictive créatif, comme en témoigne le récit sériel Jadis chez aujourd’hui du Petit Français illustré, imaginant Louis XIV et sa cour transportés à l’Exposition universelle de 1889 et visitant la Galerie des Machines avec un regard décalé sur l’époque contemporaine. Des éléments graphiques et stylistiques récurrents résultent de ce commentaire journalistique des Expositions, à l’image d’une tour Eiffel dont un seul pied suffit à constituer un indicateur chrono-topographique symbolisant la modernité contestée. Enfin, on peut considérer comment Robida prolonge à sa manière des inventions existantes, notamment dans l’illustration du texte d’Octave Uzanne La Locomotion future, paru dans Le Monde Moderne en 1895, ou avec la voiture aéroplane déclinée à partir du quadricycle Daimler apparu à l’Exposition de 1889. Le dialogue attentif et moqueur de Robida avec les projets et les discours des Expositions universelles permet de reconsidérer l’humour de l’anticipateur en le situant plus résolument dans les registres satirique et fantaisiste propres à prendre en charge les facéties du « feu congelé », du « poney-vapeur » ou du « perce-brouillard à hélice nasale », que dans la seule prospective pessimiste d’un génial visionnaire. Cet angle d’étude de l’œuvre d’anticipation offre aussi l’occasion d’examiner la part de l’intertexte d’actualité intervenant dans une pratique générique, graphique et éditoriale du panorama temporel. Entendons par là la littérature des guides pour visiteurs d’Expositions qui renoue avec une tradition des Petits-Paris initiée dans la littérature « panoramique » des années 1840. Ces parcours-découvertes balisés et ces bilans des curiosités urbaines ne sont pas sans évoquer ceux auxquels contribue Robida dans Le Vieux Paris. Guide historique, pittoresque et anecdotique (une cinquantaine de dessins), dans l’illustration du guide satirique L’Exposition comique (Dentu, 1889) ou encore dans le récit illustré du Dix-neuvième Siècle. S’ils s’articulent à un passé patrimonial sous la forme d’un inventaire du siècle qui se regarde réflexivement, ils ont aussi pu contribuer à l’anticipation en associant scènes dynamiques et vues d’ensemble dans un parcours temporel indissociable de ses dimensions topographiques. [less ▲]

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See detailA wavelet-based analysis of surface air temperature regularity
Deliège, Adrien ULg; Nicolay, Samuel ULg

Conference (2014, June 19)

The aim of the talk is to present the "wavelet transform microscope" and the wavelet leaders method to show that surface air temperature signals of weather stations selected in Europe are monofractal, i.e ... [more ▼]

The aim of the talk is to present the "wavelet transform microscope" and the wavelet leaders method to show that surface air temperature signals of weather stations selected in Europe are monofractal, i.e. all the points have the same Hölder (regularity) exponent. This study reveals that the information obtained in this way are richer than previous works studying long range correlations in meteorological stations. The approach presented here allows to bind the Hölder exponents with the pressure anomalies, and such a link does not exist with methods previously carried out. Moreover, this regularity is a signature of the type of climate the stations are associated to: indeed, it is possible to establish a climate classification of weather stations in Europe which matches the Köppen-Geiger climate classification. A blind test is performed in order to confirm the results, which can be partly explained by the influence of the North Atlantic Oscillation. This result could give rise to new criteria to determine the efficiency of current climatic models. [less ▲]

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See detailThe importance of the effects of mora debitoris
Cavalleri, Vanessa ULg

Conference (2014, June 19)

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See detailSPATIODATA, un modèle de bâtiment non-constructif, collaboratif et multi-usage
Delfosse, Vincent ULg; Boulanger, Christelle ULg; Jeunejean, Aurélie ULg et al

in Actes du 6ème Séminaire de Conception Architecturale Numérique (2014, June 19)

There is an increasing number of mobile applications supporting specific activities related to the indoor building environment. SpatioData is a research project aiming at the development of a ... [more ▼]

There is an increasing number of mobile applications supporting specific activities related to the indoor building environment. SpatioData is a research project aiming at the development of a collaborative platform for the effective sharing of building-related data and supporting a wide range of different activities. This paper discusses the specific data model at the heart of the project. A comparison with the traditional BIM models is given in order to motivate the choices made in this project. [less ▲]

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See detailContribution of ion mobility for structural analysis and analytical chemistry: Use of selective IMS shift reagents (SSR)
Kune, Christopher ULg; Far, Johann ULg; Delvaux, Cédric ULg et al

Poster (2014, June 19)

Ion mobility is a gas phase separation technique based on the Collisional Cross Section (CCS) of ions. It discriminates isobaric and isomeric ions provided their CCS difference is larger than the ... [more ▼]

Ion mobility is a gas phase separation technique based on the Collisional Cross Section (CCS) of ions. It discriminates isobaric and isomeric ions provided their CCS difference is larger than the instrumental resolution. This work proposes a new method to overcome this limitation while providing additional structural information. A Selective Shift Reagent (SSR) is a ligand specifically modifying the CCS of ions. Indeed specific non-covalent complexes can be form with a suitable SSR to reach the required selectivity and the CCS induced shift. A CID dissociation of the complex may be used after IMS separation to produce specific MS/MS spectra of the targeted analyte. This concept paves the way for new analytical strategies by ion mobility based on non-covalent complex formation. [less ▲]

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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 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 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 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 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 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 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 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 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 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 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 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 detailThe circadian system sets the temporal organization of basic human neuronal function
Chellappa, Sarah Laxhmi ULg; Ly, Julien; Gaggioni, Giulia et al

Conference (2014, June 16)

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See detailA forward genetic screen to identify hydrogenase-deficient mutants in the unicellular green alga Chlamydomonas reinhardtii
Emonds-Alt, Barbara ULg; Godaux, Damien ULg; Cardol, Pierre ULg et al

Poster (2014, June 15)

The ability of the unicellular green alga Chlamydomonas reinhardtii to evolve molecular hydrogen (H2) is due to the presence of oxygen-sensitive Fe-hydrogenases (HydA1/2), expressed in anoxic conditions ... [more ▼]

The ability of the unicellular green alga Chlamydomonas reinhardtii to evolve molecular hydrogen (H2) is due to the presence of oxygen-sensitive Fe-hydrogenases (HydA1/2), expressed in anoxic conditions that drive the photosynthetic electron flow to reduce protons into H2. In order to identify new players involved in H2 photoproduction in Chlamydomonas, an insertion mutant library was generated using cassettes conferring resistance to hygromycin or paromomycin. Hydrogenase activity is physiologically relevant during a transition from dark anoxia to light. In dark anoxic conditions, the cellular redox poise is high and the photosynthetic electron transport chain is fully reduced. Upon illumination, hydrogenase activity allows the reoxidation of photosynthetic intersystem electron carriers until oxic conditions and carbon fixation ability are restored. We thus designed an in vivo fluorescence imaging screen based on the different kinetics of photosynthesis induction between wild type and hydrogenase-deficient mutants [1]. At this stage, three putative hydrogenase mutants have been identified on 10,000 transformants. Molecular characterization of the insertion site of the resistance cassette by TAIL-PCR and genetic analyses of the linkage between the antibiotic resistance and the fluorescence phenotype showed that one mutant was untagged with the resistance while two tagged mutants were deficient for the HydG assembly factor. [less ▲]

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See detailDétermination de la teneur en équol dans les laits commercialisés en Wallonie (Belgique)
Daems, Frédéric ULg; Jasselette, Christophe; Franckson, Delphine et al

Poster (2014, June 13)

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See detailThe Discretionary Use of Strasbourg Jurisprudence by the International Criminal Court
Deprez, Christophe ULg

Conference (2014, June 13)

Although the case law of the European Court of Human Rights ("ECtHR") has had and still shows critical influence on the development of the practice of the International Criminal Court ("ICC"), it remains ... [more ▼]

Although the case law of the European Court of Human Rights ("ECtHR") has had and still shows critical influence on the development of the practice of the International Criminal Court ("ICC"), it remains unclear what the authority of such external jurisprudence is vis-à-vis the international criminal judge. While it is virtually undisputed that human rights law, in general terms, is applicable to proceedings before the ICC, many scholars tend to adopt a much nuanced approach to the authority of human rights case law in particular. This paper aims to shed further light on the issue by addressing the question whether ICC judges have used Strasbourg jurisprudence in a consistent manner, in particular as regards the authority which they decided to vest the latter with. It demonstrates that ICC Chambers have relied on European human rights practice, alternatively, as a mere source of inspiration, as binding interpretation, as a corpus having ambivalent authority, or as a source whose legal value it simply left unspecified. This leads us to conclude that, on the whole, the ICC has been mostly inconsistent regarding the value of ECtHR case law in the context of international criminal proceedings. Such inconsistency, we argue, amounts to a discretionary use of Strasbourg jurisprudence that further reinforces the Court's paradoxical position as the ultimate authority for defining the boundaries of its own human rights constraint. [less ▲]

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See detailMeasuring the body, measuring through the body
Vangeebergen, Thomas ULg

Conference (2014, June 13)

Body is a particular relevant way to tackle design processes, because of the multiplicity of status it can acquire during these processes: a source of information, a target to fit, a device to perform, a ... [more ▼]

Body is a particular relevant way to tackle design processes, because of the multiplicity of status it can acquire during these processes: a source of information, a target to fit, a device to perform, a complex technology, an apparatus for the users. A specific body is presented in this paper: the measured body. Trough racial anthropology, sport performances, demographic statistics, medical treatments, psycho-cognitive surveys, quantified self, or in many other contexts, human body is subject to a wide range of various measures. I would on my own propose some thoughts grounded on field exploration, concerning sensory analysis practices, in various laboratories. According to the symmetrical glaze STS have gave from the beginning to both human and non-humans, objects and subjects, the body is for a start itself one of the “stuffs” overlapping categories, blurring distinctions between things and persons, at the same a time a given and an object to perform. The measures of the body, and made with/through the body, highlight how it could be enacted, revealed, understood, improved by technology, especially when it requires some quantitative data. But it allows us also to grasp how the body is viewed simultaneously as a technological device and as the data origin, to intervene during complex practices (e.g. standardization, lab experiments, and marketing surveys). One of the numerous outcomes of such research could be the role of these bodily measurements in the definition of the actors, as well individuals than collectives. By the way it takes on a share on the network tying body to numerical data and to materiality-other-than-human, to measure the body/ through the body seems to afford socio-materiality in a particularly productive manner. Many scholars have inquired about numbers, how they could bring objectivity, how they produce confidence and security, and how finally they participate to black-box the measures themselves. Here, the aim is to understand the specificity of the body as measurement issue, being the interface of the-objects-to-be-measured and the instrument-of-measure. [less ▲]

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See detailCopper recovery from waste electric cables by biohydrometallurgy
Lambert, Fanny ULg; Bastin, David ULg

Conference (2014, June 13)

This study examines the leaching of copper from waste electric cables by chemical leaching and leaching catalysed by Acidithiobacillus ferrooxidans in terms of leaching kinetics and reagents consumption ... [more ▼]

This study examines the leaching of copper from waste electric cables by chemical leaching and leaching catalysed by Acidithiobacillus ferrooxidans in terms of leaching kinetics and reagents consumption. Operational parameters such as the nature of the oxidant (Fe3+, O2), the initial ferric iron concentration (0-10 g/L) and the temperature (21-50°C) were identified to have an important influence on the degree of copper solubilisation. At optimal process conditions, copper extraction above 90% was achieved in both leaching systems, with a leaching duration of 1 day. The bacterial leaching system slightly outperformed the chemical one but the positive effect of regeneration of Fe3+ was limited. It appears that the Fe2+ bio-oxidation is not sufficiently optimised. Best results in terms of copper solubilisation kinetics were obtained for the abiotic test at 50°C and for the biotic test at 35°C. Moreover, the study showed that in same operating conditions, a lower acid consumption was recorded for the biotic test than for the abiotic test. [less ▲]

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See detailTrouble de la reconnaissance de soi chez des personnes atteintes de la maladie d'Alzheimer
Moyse, Evelyne ULg; Bastin, Christine ULg; Salmon, Eric ULg et al

Poster (2014, June 12)

Introduction : Outre des difficultés de mémoire épisodique, la maladie d’Alzheimer est associée à une altération progressive du fonctionnement de la mémoire sémantique où les connaissances du passé ... [more ▼]

Introduction : Outre des difficultés de mémoire épisodique, la maladie d’Alzheimer est associée à une altération progressive du fonctionnement de la mémoire sémantique où les connaissances du passé lointain sont mieux préservées que les connaissances acquises récemment. De plus, il a été rapporté que ce type de perte peut aussi se produire pour la reconnaissance de son propre visage. Une étude décrivait le cas d’une femme atteinte de la maladie d’Alzheimer à un stade avancé qui était incapable de se reconnaître sur des photographies prises dans un passé récent mais qui avait peu voire pas de difficultés à se reconnaître sur des photographies prises pendant les deux premières décennies de sa vie adulte. Cependant, la description d’une seule étude de cas pourrait être vue comme anecdotique. Objectifs : L’objectif de cette étude est d’évaluer si ce type de difficultés peut s’observer dans un plus large échantillon de patients. Pour ce faire, des patients à des stades légers à modérés de la maladie sont comparés à des sujets âgés sains sur une tâche de reconnaissance de visages (soi, familier, inconnu) appartenant à différentes périodes de vie (20 ans jusqu’à récemment). Résultats : Au stade léger, les patients présentaient des difficultés uniquement pour reconnaître le visage d’une personne familière alors qu’au stade modéré de la maladie, ces difficultés s’observaient à la fois pour le visage familier et le propre visage. De plus, comparés aux sujets âgés sains, les patients modérés avaient des difficultés pour se reconnaître sur des photos récentes, alors qu’aucune différence n’était observée pour les autres périodes de vie. Par contre, aucune différence entre les patients légers et leurs sujets contrôles n’était observée selon l’âge des visages. Par ailleurs, l’analyse des temps de réaction montraient que ces deux groupes de participants étaient plus lents pour reconnaître les photos anciennes par rapport aux photos récentes. Conclusion : La présente étude révèle que les difficultés de reconnaissance des visages évoluent avec l’avancement de la maladie, avec des difficultés qui touchent uniquement la reconnaissance de visages familiers au stade léger de la maladie mais qui s’étendent au propre visage au stade modéré. De plus, une perte graduée dans le temps de la reconnaissance de soi est observée chez les patients modérés (moindre reconnaissance de son visage récent) mais pas chez les patients légers. Au contraire, un ralentissement de la reconnaissance des photos anciennes par rapport aux photos récentes était constaté chez les patients légers ainsi que chez leurs sujets contrôles. Deux hypothèses sont avancées pour expliquer ce phénomène. Premièrement, les photos anciennes provoqueraient une réaction de surprise et par là, augmenteraient le temps de réponse. La seconde hypothèse postule plutôt une difficulté d’accès aux représentations antérieures de soi et de son proche. [less ▲]

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See detailCompeting One-Way Essential Complements : the Forgotten Side of the Net Neutrality Story}
Broos, Sébastien ULg; Gautier, Axel ULg

Conference (2014, June 12)

We examine the incentives of an internet service provider (ISP) to break net neutrality by excluding internet applications competing with its own products, a typical example being the exclusion of VoIP ... [more ▼]

We examine the incentives of an internet service provider (ISP) to break net neutrality by excluding internet applications competing with its own products, a typical example being the exclusion of VoIP applications by a telecom company offering internet and voice services. We show that exclusion is not a concern when the ISP is a monopoly because it can extract the additional surplus created by the application through price rebalancing. By contrast, when ISP’s compete, in an attempt to differentiate, only one ISP will offer the app. Applying a no-exclusion rule in this case can lead to monopoly. [less ▲]

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See detailExperimental tests and numerical modelling on eight slender steel columns under increasing temperatures
Franssen, Jean-Marc ULg; Zhao, Bin; Gernay, Thomas ULg

in Li, G.Q.; Jiang, S.C.; Chen, Suwen (Eds.) et al Progress on Safety of Structures in Fire (2014, June 11)

In order to fill the lack of knowledge about slender elements behavior at elevated temperatures,, a European research project called FIDESC4 has been funded by the RFCS. This project involves experimental ... [more ▼]

In order to fill the lack of knowledge about slender elements behavior at elevated temperatures,, a European research project called FIDESC4 has been funded by the RFCS. This project involves experimental testing, parametric numerical analyses and development of simple design rules. The present paper reports the characteristics and the results of the FIDESC4 experimental test campaign performed at the University of Liege on slender steel columns at elevated temperatures. A total of eight columns have been tested, all of them with I shape section. Six columns were made of welded sections (some prismatic and some tapered members) and two columns were with hot rolled sections. The nominal length of the columns was 3 meters with the whole length being heated. The strength of the material (webs and flanges) was measured on sample before the tests. The order of magnitude of the initial geometrical imperfections was recorded. The columns were not restrained against longitudinal thermal elongation. The supports at the ends were cylindrical thus inducing a restrain against rotation in one plane while allowing rotation in the other plane. The allowed direction of rotation was chosen in each test to induce buckling around the strong or the weak axis. The load was applied at ambient temperature and maintained for a period of 15 minutes after which the temperature was increased under constant load. The load was applied concentrically on some tests and with an eccentricity in other tests. The load eccentricity was either applied at both ends, leading to constant bending moment distribution along the length, or at one end only, leading to a triangular bending moment distribution. Heating was applied by electrical resistances enclosed in ceramic pads. The columns and the ceramic pads were wrapped in ceramic wool insulating material. This technique was preferred to gas heating in a standard test furnace because it allows applying a slower and better controlled heating rate and thus obtaining a more uniform temperature distribution in the member. It is also easier to measured lateral displacements of the column. Preliminary blank tests were performed on unloaded specimen in order to determine the heating range to be used later on the loaded columns. The paper will also report on a modification of the heating technique that was applied and improved significantly the uniformity in the temperature distribution. Numerical simulations were performed before the tests using shell elements of the software SAFIR and assumed values of the material properties in order to predict the failure modes. It was essentially crucial to determine whether lateral supports at intermediate levels should be provided in order to ensure failure in the desired direction. Experience showed that the failure modes developed as predicted by the numerical simulations. Besides a thorough description of the experiments, the paper will also present the obtained results in terms of failure mode, ultimate temperature and evolution of longitudinal and transverse displacement. Some information will also be given about the level of detail that has to be used in the numerical model in order to get accurate results at a reasonable price. [less ▲]

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See detailInternet : support, médium ou épimédium ?
Barnabé, Fanny ULg; Dozo, Björn-Olav ULg

Conference (2014, June 11)

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See detailLes remèdes d'origine égyptienne utilisés dans la médecine vétérinaire antique
Marganne, Marie-Hélène ULg

Conference (2014, June 10)

Recherche systématique des ingrédients d'origine égyptienne attestés dans les recettes des écrits vétérinaires grecs et latins, et comparaison de leur utilisation à celle de la médecine humaine, avec ... [more ▼]

Recherche systématique des ingrédients d'origine égyptienne attestés dans les recettes des écrits vétérinaires grecs et latins, et comparaison de leur utilisation à celle de la médecine humaine, avec évaluation de leur accessibilité et leur coût. [less ▲]

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See detailSoil infrastructure evolution and its effect on water transfer processes under contrasted tillage systems - overview of methodologies with preliminary results
Parvin, Nargish ULg; Colinet, Gilles ULg; Garré, Sarah ULg et al

Conference (2014, June 10)

The heterogeneity of soil structure and porosity are highly influenced by external factors like tillage systems and other land management approaches. The aim of this project is to investigate the effect ... [more ▼]

The heterogeneity of soil structure and porosity are highly influenced by external factors like tillage systems and other land management approaches. The aim of this project is to investigate the effect of soil tillage along with residue management on the changing pattern of soil structure. This investigation will help to emphasize the different water flow dynamics especially the preferential flow processes through the soil that are influenced by the changes in structural distribution in the soil profile. The experimentation has been started from June 2013 in the research field in Gembloux. Soil profile description together with soil sampling has been carried out in the four objects of land management. Soil samples will be used for the measurement of water retention capacity (done), hydraulic conductivity and x-ray microtomography. The assessment of soil water retention curves with pressure plate technique show significantly (p<0.05) higher water retention (Hwr) in WP than ST at 9.8 to 98 hPa, Hwr in WP than NI at 39 to 14710 hPa, Hwr in ST than NI at 294 to 14710 hPa and Hwr in WP than NO at 69 to 98 hPa. There was no significant difference in the water retention between NO and NI and ST and NO. Since, tillage practices generally increase soil porosity, the correlation between soil hydraulics and porosity distribution would expect to be different for different tillage systems. In our study, WP retains more water due to the increase of macroporosity than ST, NI and NO. As the changes in soil structure are usually noticed in the range of 9.8 to 98 hPa, so, we can conclude that there is certainly structural change between WP and conservation practices of ST, NI and NO. In our study, there will be also soil moisture sensors (Decagon 10HS, 5TM and ML3 Thetaprobe) to capture the total soil moisture networks in the field under four different trials. The soils from the different trials and also from different depths (0-15, 25-30 and 50-60 cm) were used for zone specific calibration of the sensors. All the experiments will be repeated twice a year. For the specific spatio-temporal comparison, the monitoring results from electrical resistance tomography will be available from the collaborated project of the same faculty. [less ▲]

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See detailGround-based transmission spectrum of WASP-80 b, a gas giant transiting an M-dwarf
Delrez, Laetitia ULg; Gillon, Michaël ULg; Lendl, Monika ULg et al

Poster (2014, June 09)

We present here some results from our ground-­based multi-­object spectroscopy program aiming to measure the transmission spectrum of the transiting hot Jupiter WASP-80b using the VLT/FORS2 instrument ... [more ▼]

We present here some results from our ground-­based multi-­object spectroscopy program aiming to measure the transmission spectrum of the transiting hot Jupiter WASP-80b using the VLT/FORS2 instrument. WASP-­80b is a unique object as it is the only known specimen of gas giant orbiting an M-dwarf that is bright enough for high SNR follow-­up measurements. Due to the nature of its host star, this hot Jupiter is actually more `warm' than `hot', with an estimated equilibrium temperature of only 800K. It is thus a prime target to improve our understanding of giant exoplanet atmospheres in this temperature range. [less ▲]

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See detailHigher Symmetries of the conformal Laplacian
Radoux, Fabian ULg

Conference (2014, June 09)

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See detailFe and Mg Isotope Fractionation in Olivine from the NWA 1068 Shergottite
Collinet, Max ULg; Charlier, Bernard ULg; Namur, Olivier et al

Conference (2014, June 09)

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See detailEffects of tillage practices and crop residue exportation on earthworm communities and soil physico-­chemical properties in silt loam arable soil (Belgium)
Lemtiri, Aboulkacem ULg; Colinet, Gilles ULg; Alabi, Taofic ULg et al

Poster (2014, June 08)

Earthworms are known to play integral roles in soils, and are often referred to as vital soil and ecosystem engineers due to their capacity to influence a wide range of chemical, physical, and biological ... [more ▼]

Earthworms are known to play integral roles in soils, and are often referred to as vital soil and ecosystem engineers due to their capacity to influence a wide range of chemical, physical, and biological properties of soil environments. Therefore, it is important to understand how earthworm communities are impacted by tillage systems and crop management practices. In the present study, earthworm and soil samples were collected from wheat cultivated fields in Gembloux, Belgium under the following four experimental treatments: (1) conventional tillage with crop residues left in the soil (CT/IN); (2) conventional tillage with crop residues removed from the field (CT/OUT); (3) reduced tillage with crop residues left in the soil (RT/IN); and (4) reduced tillage with crop residues removed from the field (RT/OUT). The different tillage systems were applied for four consecutive years prior to the initiation of the current study. Results indicated soil compaction was significantly higher in RT compared with CT up to a depth of 6–49 cm. Significant differences were not detected between residue incorporation depth systems, where results showed mean earthworm abundance was respectively 182.25 and 180 individuals.m-2 in CT and RT. Mean earthworm biomass was similarly not significantly different between CT and RT, where results were respectively 48.52 and 57.27 g.m-2. However, a significant difference was observed between IN and OUT treatments, suggesting the exportation of wheat residues will limit earthworm abundance and biomass in CT and RT plots. Data showed high representation of the endogeic earthworm ecological category, notably N. c. caliginosus regardless of treatment. Despite tillage system and exportation of crop residues, N. c. caliginosus, L. terrestris, and A. r. rosea exhibited high abundance, indicating tolerance to soil environmental conditions. For each depth, measures of soil physico-chemical properties showed significant differences among treatments. Furthermore, soil chemical property attributes were significantly higher in the first soil centimetres compared to lower soil layers. These results were attributable to earthworm activity and wheat residues, suggesting earthworms contributed to nutrient dynamics, particularly at increased soil depths. Overall, the results emphasise the influence of exportation of crop residues on earthworm community and also, the important influence of earthworm activity on soil physico-chemical properties change, processes which are closely linked. [less ▲]

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See detailFast Ambient Pressure Thermal cycling of space solar arrays samples under equivalent AM0 illumination conditions
Guiot, Marc ULg; Fernandez Lisbona, Emilio; Witteveen, Bob et al

Conference (2014, June 08)

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See detailLe sort des travailleurs d’une entreprise en réorganisation judiciaire
Kéfer, Fabienne ULg; Gailliet, Guillaume ULg

in Clesse, Jacques (Ed.) Questions choisies de droit social. Hommage à Michel Dumont (2014, June 06)

Le droit de l’entreprise en difficulté entretient avec le droit du travail des liens tendus. La préservation du potentiel économique de l’entreprise s’affronte aux dispositions visant à éviter la ... [more ▼]

Le droit de l’entreprise en difficulté entretient avec le droit du travail des liens tendus. La préservation du potentiel économique de l’entreprise s’affronte aux dispositions visant à éviter la dégradation de la situation des travailleurs. Le complexe normatif étudié reflète le point actuel du rapport de force entre le monde économique et les syndicats. Les salariés sont, en définitive, amenés à faire une grande partie du sacrifice nécessaire pour atteindre l’objectif économique recherché. Ce constat est perceptible dans l’hypothèse d’une réorganisation par accord collectif et dans celle du transfert sous autorité de justice, qui témoignent des rapports complexes entre les intérêts économiques et sociaux. La conciliation de ces intérêts divergents s’effectue sous la surveillance du juge. [less ▲]

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See detailOn-the-fly domain adaptation of binary classifiers
Pierard, Sébastien ULg; Marcos Alvarez, Alejandro ULg; Lejeune, Antoine ULg et al

in 23rd Belgian-Dutch Conference on Machine Learning (BENELEARN) (2014, June 06)

This work considers the on-the-fly domain adaptation of supervised binary classifiers, learned off-line, in order to adapt them to a target context. The probability density functions associated to ... [more ▼]

This work considers the on-the-fly domain adaptation of supervised binary classifiers, learned off-line, in order to adapt them to a target context. The probability density functions associated to negative and positive classes are supposed to be mixtures of the source distributions. Moreover, the mixture weights and the priors are only available at runtime. We present a theoretical solution to this problem, and demonstrate the effectiveness of the proposed approach on a real computer vision application. Our theoretical solution is applicable to any classifier approximating Bayes' classifier. [less ▲]

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See detailSolar irradiance modelling over Belgium using WRF-ARW : A sensitivity analysis of Mellor-Yamada-Nakanishi-Niino (BYNN) boundary layer scheme parameters
Beaumet, Julien ULg; Doutreloup, Sébastien ULg; Fettweis, Xavier ULg et al

Conference (2014, June 06)

Global solar irradiances at ground level are modelled over Belgium using latest version of WRF-ARW regional climate model (RCM). The model set-up used has a resolution of 5 kilometres. The boundary layer ... [more ▼]

Global solar irradiances at ground level are modelled over Belgium using latest version of WRF-ARW regional climate model (RCM). The model set-up used has a resolution of 5 kilometres. The boundary layer scheme chosen is the Mellor-Yamada-Nakanishi-Niino (MYNN) 2.5 scheme with the Turbulent Kinetic Energy (TKE) closure proposed by Canuto et al., (2008) and Kitamura (2010). In this scheme, the modification of some parameters allows to change the determinant mixing length (surface layer, planet boundary layer, top of boundary layer/entrainment) which then modifies heat and moistures fluxes produced by turbulent mixing. Such modifications have significant influences on modelled cloudiness and therefore on modelled global solar irradiance incoming at the surface. The present study proposes a sensitivity analysis of the different parameters that influence the mixing length ('alp1' to 'alp5') and the TKE diffusion ('Sqfac') in order to find the most suitable constant values of these parameters for the modelling of cloudiness over Belgium. Results of different simulations are compared with global solar irradiance measurements performed by the Centre Spatial de Liège at Sart-Tilman in 2013 and 2014. Firsts results show that the dry bias frequently found when using WRF-ARW with standard set-ups can be greatly reduced thanks to an increased modelled cloudiness. The quantitative and qualitative effects of these modifications over cloudiness are also analysed by displaying 2D representation of modelled clouds over Sart-Tilman and confronting them with on-site observations. [less ▲]

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See detailA wavelet-based analysis of surface air temperature variability
Deliège, Adrien ULg; Nicolay, Samuel ULg

Conference (2014, June 06)

We study the Hölder regularity of surface air temperature signals using the wavelet leaders method (WLM). This method has been successfully applied in several domains such as DNA analysis, fully ... [more ▼]

We study the Hölder regularity of surface air temperature signals using the wavelet leaders method (WLM). This method has been successfully applied in several domains such as DNA analysis, fully developped turbulence analysis, internet data traffic analysis,... to name just a few, and we now use it in climatology. We first define the notions of Hölder exponent, monofractal functions and spectrum of singularities before explaining the WLM. Then we use it to study surface air temperature signals from weather stations spread across Western and Eastern Europe and show that they are monofractal, i.e. their irregularity (in the sense of variability) is regular. After, we show that the stations can be classified according to their Hölder exponent and that this classification matches with the worldwide used Köppen-Geiger climate classification. A blind test is performed in order to confirm the results, which can be partly explained by the influence of the North Atlantic Oscillation. Our results can be helpful to test the accuracy of current climatic models. [less ▲]

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See detail[18F]UCB-H AS A NEW PET RADIOTRACER FOR SYNAPTIC VESICLE PROTEIN 2A
Bahri, Mohamed Ali ULg; Bastin, Christine ULg; Aerts, Joël ULg et al

Poster (2014, June 06)

Synaptic vesicle protein 2A (SV2A) is widely distributed in the brain and has been demonstrated to be involved in vesicle trafficking. The critical role of SV2A in proper nervous system function is shown ... [more ▼]

Synaptic vesicle protein 2A (SV2A) is widely distributed in the brain and has been demonstrated to be involved in vesicle trafficking. The critical role of SV2A in proper nervous system function is shown, for example, by the fact that it is a binding site and the primary mechanism of levetiracetam. Levetiracetam is an antiepileptic drug which has recently been suggested to reduce synaptic deficits in a mouse model for Alzheimer’s disease and to improve cognition in patients with amnestic mild cognitive impairment. We here aimed to investigate the cerebral distribution of [18F]UCB-H, a fluorine-18 radiolabelled PET imaging tracer, which has a high affinity with the SV2A. [18F]UCB-H was radiosynthesized under GMP conditions. Dynamic PET data of the head of four healthy volunteers were acquired over 100 minutes after injection of 170.4 ± 24.9 MBq of [18F]UCB-H. The arterial input function was obtained by blood sampling during the dynamic PET acquisition. The analysis of the blood data reveled a consistent amount of [18F]UCB-H in whole blood and plasma which indicates a very low degree of binding of the tracer to the red blood cells. The unchanged fraction of [18F]UCB-H in plasma showed a bi-exponential behavioral decrease with a starting fraction of 92% of the injected amount of the tracer, measured at 3 min post injection. This fraction decreased to about 50% at 10 min post injection. The [18F]UCB-H PET data showed a high and rapid uptake in the grey matter structures, matching the known ubiquitous distribution of the SV2A in the brain. The kinetics of the tracer in the brain was characterized by an initial high uptake phase followed by rapid washout allowing the standard compartmental modeling (1-tissue compartment, 2-tissue compartment, and Logan graphical analysis). The three models gave consistent results. The two-tissue compartment model fitted the experimental data best and provided a total distribution volume of the [18F]UCB-H in the brain greater than 7 mL/cm3 and a specific distribution volume around 3 mL/cm3. Our results suggest that [18F]UCB-H is a good candidate as radiotracer for brain SV2A proteins and could be used for human studies. In the future, SV2A modifications might be assessed in neurological pathologies such as Alzheimer’s disease. [less ▲]

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See detailMuti-scale methods with strain-softening: damage-enhanced MFH for composite materials and computational homogenization for cellular materials with micro-buckling
Wu, Ling ULg; Nguyen, Van Dung ULg; Adam, Laurent et al

Conference (2014, June 06)

In this work, multi-scale methods with strain softening are developed in the contexts of damage modeling for composite laminates and of buckling analyses in cellular materials. First, an anisotropic ... [more ▼]

In this work, multi-scale methods with strain softening are developed in the contexts of damage modeling for composite laminates and of buckling analyses in cellular materials. First, an anisotropic gradient–enhanced continuum damage model is embedded in a mean–field homogenization (MFH) process for elasto-plastic composites. The homogenization procedure is based on the newly developed incremental secant mean-field homogenization formulation, for which the residual stress and strain states reached in the phases upon a fictitious elastic unloading are considered as starting point to apply the secant method. The mean stress fields in the phases are then computed using isotropic secant tensors, which are naturally used to define the Linear Comparison–Composite The resulting multi– scale model is then applied to study the damage process at the meso–scale of laminates, and in particular the damaging of plies in a composite stack. By using the gradient–enhanced continuum damage model, the problem of losing uniqueness upon strain softening is avoided. Second, an efficient multi–scale finite element framework capturing the buckling instabilities in cellular materials is developed. As a classical multi–scale computational homogenization scheme loses accuracy with the apparition of the macroscopic localizations resulting from the micro–buckling, the second order multi–scale computational homogenization scheme is considered. This second–order computational framework is enhanced with the following novelties so that it can be used for cellular materials. At the microscopic scale, the periodic boundary condition is used because of its efficiency. As the meshes generated from cellular materials exhibit a large void part on the boundaries and are not conforming in general, the classical enforcement based on the matching nodes cannot be applied. A new method based on the polynomial interpolation2 without the requirement of the matching mesh condition on opposite boundaries of the representative volume element (RVE) is developed. Next, in order to solve the underlying macroscopic Mindlin strain gradient continuum of this second–order scheme by the displacement–based finite element framework, the treatment of high order terms is based on the discontinuous Galerkin (DG) method to weakly impose the C1-continuity. Finally, as the instability phenomena are considered at both scales of the cellular materials, the path following technique is adopted to solve both the macroscopic and microscopic problems. [less ▲]

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See detailComparison between wind speed observed at 100m height and wind speeds simulated by the WRF and MAR models
Doutreloup, Sébastien ULg; Fettweis, Xavier ULg; Erpicum, Michel ULg et al

Poster (2014, June 06)

In the context of FLEXIPAC project funded by "RELIABLE" program of Walloon Region (Belgium), the Laboratory of Climatology and Topoclimatology (LCT) of the University of Liège (Belgium) aims to adjust the ... [more ▼]

In the context of FLEXIPAC project funded by "RELIABLE" program of Walloon Region (Belgium), the Laboratory of Climatology and Topoclimatology (LCT) of the University of Liège (Belgium) aims to adjust the WRF regional model (v.3.4.) forced by ERA-Interim model. Our analysis shows that wind speeds at 100m height simulated by WRF are systematically overestimated compared to wind speeds extracted from wind productions of two wind farms. In order to identify this problem, four comparisons were performed in this contribution. Firstly, we compare WRF model with reanalysis based forcing model. Secondly, we compare two WRF simulations, where one of them has a more precise spatial resolution. Thirdly, we smooth WRF outputs in time (6-hr running mean) in order to study the accuracy of the 30-min variability generated by WRF model. Finally, we comp compare the WRF model with the MAR (v3.3.) regional model using the same forcing at its lateral boundaries. This last one seems to suggest that the MAR model better simulates wind speeds at 10m and at 100m than WRF model and then that wind speed underestimation by WRF is well linked to the WRF physics itself. [less ▲]

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See detailBiorefine: Recovery of nutrients and metallic trace elements from different wastes by chemical and biochemical processes
Tarayre, Cédric ULg; Fischer, Christophe ULg; De Clercq, Lies et al

Conference (2014, June 05)

At present, most waste processing operations are not oriented towards the valorization of valuable reusable components such as nitrogen, phosphorus, potassium and even Metallic Trace Elements (MTEs ... [more ▼]

At present, most waste processing operations are not oriented towards the valorization of valuable reusable components such as nitrogen, phosphorus, potassium and even Metallic Trace Elements (MTEs). Currently, sewage sludge, for example is usually used as a fertilizer in agriculture, in energy production or in the field of construction. Ashes originating from sludge incineration contain heavy metals and minerals in large quantities. Manure is mainly used in agriculture, although considerable amounts of nutrients are lost and cause pollution. Digestate is also used in agriculture, but other alternatives have been proposed, such as the energetic valorization. Better valorization of these wastes in agriculture (or other sectors) is however largely constrained by a multitude of legal requirements. An important problematic point is the concentration in MTEs that is found in those wastes. Consequently, recovery of nutrients and MTEsmay be a key solution for optimal valorization of wastes. Many unit operations used in the field of chemical and biochemical engineering (mechanical operations on fluids, solids, mass and heat transfers, chemical reactions, etc.) could be used in order to achieve an efficient recovery yield of nutrients and trace elements. The aim of the BioRefine Project is to make an inventory of all recovery techniques of nutrients and MTEs in five countries: Belgium, France, Germany, United Kingdom and The Netherlands. Pilot plants will also be tested to assess the efficiency of new treatment techniques after which the most efficient processes will be chosen to be applied on a larger scale. In addition, the collected data will be used to propose exploitation scenarios taking into account legal constraints and optimized logistics.This work is supported through an INTERREG IVB NWE programme(ref. 320J-BIOREFINE). [less ▲]

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See detailLIGAND-INDEPENDENT IDENTIFICATION OF ORPHAN GPCR ARRESTIN BINDING
Dupuis, Nadine ULg; Gilissen, Julie ULg; Derj, Anouar ULg et al

Poster (2014, June 05)

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See detailMALDI Mass Spectrometry Imaging: a new tool to decipher the antibiome of Bacillus amyloliquefaciens
Debois, Delphine ULg; Jourdan, Emmanuel; Cawoy, Hélène et al

Conference (2014, June 05)

Soil Bacillus isolates may devote up to 8% of their genome to nonribosomal synthesis of lipopeptide (LP)- and polyketide (PK)-type antibiotics. LPs from surfactin, iturin and fengycin families are known ... [more ▼]

Soil Bacillus isolates may devote up to 8% of their genome to nonribosomal synthesis of lipopeptide (LP)- and polyketide (PK)-type antibiotics. LPs from surfactin, iturin and fengycin families are known to exert different actions on the wellness of the producing strain such as fungitoxicity (iturin, fengycin) or motility, root colonization and immune stimulating agent (surfactin). Nevertheless, few is reported about the actual antibiome secreted in situ by Bacillus cells during confrontation with phytopathogens or plant root colonization. We developed a method mimicking the conditions prevailing in the rhizosphere and, taking advantage of the versatility of Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging, we were able to localize and identify antibiotics produced in situ by bacterial cells. First, we applied this new methodology to bioassays in which Bacillus amyloliquefaciens 98S were grown together with Fusarium oxysporum, with the aim of deciphering the role of the different LP families during the phytopathogen growth inhibition. Our results showed that the three LP families were readily produced in different proportions. Especially, images of surfactins, iturins and fengycins demonstrated that iturins are the antibiotic family actually involved in the antagonism against Fusarium oxysporum. In a second approach, we used a “in planta” model in which Bacillus amyloliquefaciens S499 was simultaneously grown with Tomato and Arabidopsis thaliana roots. Imaging results, obtained during a time course analysis, showed that surfactin is always the major lipopeptide detected. In further experiments involving a refined time-window, we observed that surfactin is actually produced as soon as 24h post inoculation. These results were the starting point of a wider study showing that the early accumulation of surfactin is a complex phenomenon involving, among other mechanisms, cell-well components recognition by bacteria, and that this interaction is a win-win association for both plant and bacterial cells. [less ▲]

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See detailLa charge de confesseur princier au XVIIème siècle, une définition controversée
Pirlet, Pierre-François ULg

Conference (2014, June 05)

Si la mission d'un confesseur au début du XVIIème siècle est strictement définie par les textes canoniques du catholicisme comme celle d'un administrateur de sacrement, la définition des tâches revenant ... [more ▼]

Si la mission d'un confesseur au début du XVIIème siècle est strictement définie par les textes canoniques du catholicisme comme celle d'un administrateur de sacrement, la définition des tâches revenant au confesseur du Prince est étonnamment lâche. Du premier, on attendait qu'il jugeât les actes de son pénitent, propose une consolation – sous la forme d'exercices expiatoires – destinés à le réconcilier avec Dieu, et offre une direction spirituelle visant à prévenir les rechutes dans le péché. Mais confesser le Prince contraignait le religieux qui s’y attelait à un exercice bien plus complexe. Il lui revenait de juger et d'apporter une direction de conscience aux deux personnes du roi : l'humaine et l'institutionnelle. En effet, il eût été impossible de distinguer formellement l'âme du souverain de celle du mortel. De même, il échoyait au confesseur de conseiller son pénitent quant à l'aspect moral de ses décisions, que celles-ci n'impliquèrent que sa personne, ou au contraire l'ensemble des territoires et des sujets sous sa conduite. De cette difficulté naquit une controverse quant à l'implication nécessaire et raisonnable du confesseur princier dans les affaires temporelles : la papauté, les rois d'Espagne, les ecclésiastiques de cour madrilènes, les gouverneurs-généraux des Pays-Bas et les supérieurs des ordres religieux dont étaient issus les confesseurs – et particulièrement la Compagnie de Jésus – proposèrent tous une définition différente – et controversée – des prérogatives de ce religieux au cœur du pouvoir. En prenant appui sur la situation des confesseurs de la cour de Bruxelles durant la grande première moitié du XVIIème siècle, nous tâcherons au travers de cette communication de proposer un aperçu global des différentes définitions de la confession princière telles que défendues par les contemporains. Notre exposé proposera en outre un rapide regard sur les deux approches utilisées par les historiens pour reconstituer les différentes définitions de la charge : à la patiente collecte et à l'analyse des traces laissées dans les sources par l'activité au quotidien des confesseurs (approche bottom-up) se confronte une méthode cherchant une définition d'époque des prérogatives de ces religieux faisant autorité (approche top-down). Nous constaterons que ces deux approches, qui ne s'opposent pas, s’accommodent néanmoins difficilement l'une à l'autre, créant ainsi une controverse non plus dans l'objet, mais dans la méthode. [less ▲]

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See detailA PREFERENTIAL FOLDED CONFORMATION OF SOME BIS-(8-ISOPROPYL-ISOQUINOLINIUM) DERIVATIVES EXPLAINS STEREOSELECTIVE REDUCTION BY SODIUM BOROHYDRIDE
Dilly, Sébastien ULg; Badarau, Eduard; Dufour, Fabien et al

Poster (2014, June 05)

Small conductance Ca2+-activated K+ (SK) channels play a role in modulating the firing rate and the firing pattern of neurons [Waroux, Eur J Neurosci, 2005, 22, 3111]. A blockade of these targets could be ... [more ▼]

Small conductance Ca2+-activated K+ (SK) channels play a role in modulating the firing rate and the firing pattern of neurons [Waroux, Eur J Neurosci, 2005, 22, 3111]. A blockade of these targets could be useful for the treatment of cognitive dysfunction, neuronal hyperexcitability or dopamine related disorders [Liégeois, Curr Med Chem, 2003, 10, 625]. At the peripheral level, the inhibition of these channels was demonstrated to prevent and terminate atrial fibrillation [Diness, Circ Arrhythm Electrophysiol, 2010, 3, 380]. Moreover, SK channels might represent potential targets for a new class of anticancer agents due to their involvement in breast cancer cell migration [Potier, Mol Cancer Ther, 2006, 5, 2946]. So far, available blockers are not suitable CNS pharmacological tools being either peptides or small molecules with permanent positive charges [Liégeois, Curr Med Chem, 2003, 10, 625; Graulich, J Med Chem, 2007, 50, 5070; Badarau, Bioorg Med Chem Lett, 2011, 21, 6756]. Therefore, symmetrical bis-isoquinolinium compounds have subsequently been transformed to 1,2,3,4-tetrahydroisoquinoline analogues by using sodium borohydride leading to a diastereoisomeric mixture (figure 1) in order to obtain potential CNS-penetrating agents [Graulich, Bioorg Med Chem Lett, 2008, 18, 3440; Neny, Proceedings of the 12th International Conference on In Vivo Methods, Vancouver, Canada, 2008, 267; Koulchitsky, Acta Physiologica, 2009, 195, 670]. Resolution of these mixtures and characterization of the corresponding stereoisomers [Wouters, Eur J Med Chem, 2010, 45, 3240] are necessary before further biological evaluation. In a series of 8- isopropyl analogues, chiral resolution failed for the analogues with propyl and m-xylyl linkers since two and one peaks, respectively, were detected [Nistor, J Pharm Biomed Anal, 2013, 74, 273]. Could these results be explained by an ineffective resolution or would another phenomenon be involved? Further analysis using chiral chromatography, mass spectroscopy and circular dichroism of a sample of the propyl analogue revealed that it is a racemic mixture. X-ray cristallography and conformational analysis indicated a folded conformation of the propyl and m-xylyl analogues (figure 2) responsible for a stereoselective attack of the borohydride reagent during the reduction step. Additional 1H-NMR investigations support structural features detected by theoretical analysis. [less ▲]

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See detailLes médiateurs scolaires en action : des discours aux pratiques
Dethier, Baptiste ULg

Conference (2014, June 05)

En 1993, dans un contexte marqué les questions d’insécurité, de violence scolaire, de crise de confiance envers les institutions ou encore de décrochage scolaire, 28 médiateurs sont engagés dans autant ... [more ▼]

En 1993, dans un contexte marqué les questions d’insécurité, de violence scolaire, de crise de confiance envers les institutions ou encore de décrochage scolaire, 28 médiateurs sont engagés dans autant d’établissements scolaires aux publics défavorisés de la région bruxelloise. Ce projet pilote, voyant le jour sous la houlette du Ministère de l’enseignement, ne sera institutionnalisé qu’en 1998 dans un décret créant le Service de Médiation Scolaire, divisé en deux entités : 56 médiateurs internes à Bruxelles et 30 médiateurs externes (répartis par zones couvrant plusieurs établissements) en Wallonie. Par ailleurs, d’autres niveaux de pouvoir (communes, diocèses, écoles) créaient également, localement, leurs propres fonctions de médiateur scolaire. Actuellement, on en dénombre environ 120 en Belgique francophone. Ce nouvel acteur, bien que peu étudié, incarnerait un nouveau mode de régulation sociale (Bonafé-Schmitt, 1996) remettant en question les équilibres historiques du système scolaire (Verhoeven, 1997). En effet, il se présente comme un tiers neutre et indépendant de l’établissement, permettant ainsi la création d’un espace où peuvent se résoudre différents problèmes concernant les personnes demandeuses, qu’elles soient élèves, membres du personnel scolaire ou encore parents. Dans un premier temps, notre attention se porte sur l’ensemble des acteurs portant le nom de médiateurs scolaires (Kuty et al., 2012). Au sein d’un cadre légal ne définissant que vaguement leur fonction, ces derniers sont néanmoins globalement chargés de prévenir la violence et le décrochage scolaires et de favoriser, conserver ou rétablir le climat de confiance entre élèves, écoles et familles. À partir de là, ils ont progressivement construit leurs propres pratiques et leur identité, cherchant par là à trouver et à consolider leur place au sein d’un milieu scolaire déjà marqué par la présence de multiples acteurs. Dans un second temps, des études de cas approfondies dans six établissements d’enseignement secondaire permettent de constater que les médiateurs ne disposaient pas du monopole de la médiation (Dubois et Dethier, 2013), concept polysémique auquel de nombreux acteurs se réfèrent pour qualifier certains aspects de leur travail quotidien. En outre, le recours à la médiation ou aux médiateurs ne se révèle être qu’une solution parmi d’autres pour faire face aux différents problèmes rencontrés par les acteurs : violence, décrochage, absentéisme, échec scolaire, conflits, problèmes socio-économiques… Ces constats exigent une étude empirique approfondie du travail concret réalisé par les médiateurs scolaires, une étude attentive à leurs discours mais aussi à l’observation de leurs pratiques et interactions directes avec les différents acteurs scolaires. Les résultats de cette étude font l’objet de cette communication. Cette contribution se base sur un corpus composé de onze entretiens individuels, trois focus groups et trois périodes d’observation non participante auprès de médiateurs belges francophones membres d’un même service. Ces derniers revendiquent une posture de tiers neutre et indépendant dans l’école, ainsi que des principes basés sur le non-jugement, la confidentialité, l’accueil inconditionnel de la demande ou encore la non-expertise. Il s’agira par conséquent de rendre compte de la manière dont ces médiateurs traduisent leurs discours en pratiques au quotidien. [less ▲]

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See detailLa psychopathologie à la lumière des histoires de vie : Etude de la fonction narrative d’adolescents obèses et dépressifs.
Jadin, Aurore ULg; Gauthier, Jean-Marie ULg; Boulard, Aurore ULg

in Née, Emilie; Daube, Jean-Michel; Valette, Mathieu (Eds.) et al Proceedings-Actes des 12èmes journées internationales d'analyse statistique de données textuelles (2014, June 05)

Obesity in adolescence is a complex chronic illness with havy consequences in short, medium and long terms, both in terms of physical health and mental health, disturbing the body and identity of these ... [more ▼]

Obesity in adolescence is a complex chronic illness with havy consequences in short, medium and long terms, both in terms of physical health and mental health, disturbing the body and identity of these youngs (High Authority of Health, 2011; Nietsen and Bruwier, 2007). The literature mentions depression as a pathology associated with obesity. Some researchers consider obesity as a cause of depressive symptoms while others researchers see depression like a risk factor for excessive weight gain (Blaine, 2008). Depression in adolescence has been the subject of epidemiological studies for some years. In adolescents, the prevalence rates vary from 5 to 7 % for major depressive episode (MDE) with a prevalence of 2 girls for one boy (Alvin and Marcelli, 2005). The specific symptoms of depressed mood are present in 30-40 % of schooled adolescents (Boulard et al., 2012). During adolescence, the individual acquires the ability to link the various elements of one’s life and build a coherent life story. The adolescent will write one’s story in a personal context. According to Habermas et al. (2008), both the form and the content of life stories show how the individual integrates the lived experiences in a coherent whole. Based on the statistical analysis of textual data, we compared the life stories of 28 obese adolescents, depressed schooled adolescents, depressed hospitalized adolescents and control ones. The first results show specific structures and particular contents depending on these groups. The use of pronouns, temporal markers and the reported events differ by groups. Beyond clinical results, this research also highlights the interest of statistical analysis of textual data (ADT) to improve the understanding of adolescent’s psychopathology. [less ▲]

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See detailApproche lexicométrique des controverses climatiques
Scotto d'Apollonia, Lionel; Luxardo, Giancarlo; Piet, Grégory ULg

Poster (2014, June 05)

D’un point de vue historique, les controverses climatiques prennent racine à la fin du XIXe siècle et se sont déployées tout au long du XXe siècle. Elles prennent toutefois une tournure plus politique, en ... [more ▼]

D’un point de vue historique, les controverses climatiques prennent racine à la fin du XIXe siècle et se sont déployées tout au long du XXe siècle. Elles prennent toutefois une tournure plus politique, en ce début de XXIe siècle, en ce sens que le débat climatique « se priorise » dans les agendas politiques des Etats européens, de manière générale. Si les études sur les controverses climatiques tendent, certes, à se développer de plus en plus actuellement, l’approche linguistique demeure peu investie par rapport au potentiel analytique qu’elle pourrait apporter à la recherche sur le sujet. L’une des rares études lexicométriques concernant le climat est celle réalisée par Lamria Chetouani dont le corpus de textes s’étend de 1989 à 1990. Il faut aussi prendre en compte les travaux de Francis Chateauraynaud, qui a entrepris une démarche destinée au traitement des controverses s'appuyant sur un ensemble de techniques : la socio-informatique. Inscrit dans un cadre d’analyse socioépistémique des controverses socioscientifiques et en se basant sur un corpus de textes choisis autour de la période 2009 - 2010, notre article propose donc d'associer une analyse socio-informatique des controverses climatiques avec une utilisation d'outils lexicométriques. En nous concentrant sur le traitement discursif de quelques notions-clés, notamment l'incertitude et le risque, nous cherchons à croiser les résultats fournis par la lexicométrie (logiciel Lexico) avec ceux fournis par la socio-informatique (logiciel Prospero). En conclusion, nous ouvrons un espace de discussion sur les modes opératoires permettant d'articuler les deux approches. [less ▲]

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See detailExploration du récit de vie d’adolescents
Poudat, Céline; Boulard, Aurore ULg

in Née, Emilie; Daube, Jean-Michel; Valette, Mathieu (Eds.) et al Proceedings-actes des 12èmes journées d'analyse statistique de données textuelles (2014, June 05)

The present paper follows on from the research we presented in previous JADT (Boulard, Poudat, Gauthier 2012). We still focus on the development of narrative competence (Habermas et Bluck 2000) in ... [more ▼]

The present paper follows on from the research we presented in previous JADT (Boulard, Poudat, Gauthier 2012). We still focus on the development of narrative competence (Habermas et Bluck 2000) in children and adolescents. Although children develop narrative skills, life narratives only emerge in adolescence. On the basis of a corpus made of spontaneous oral speech, we had empirically demonstrated that pre-adolescents aged of 12 had developed stabilized narrative skills enabling them to produce life narratives. Here, we propose a first exploration of the overall structure of adolescent life stories, thanks to a corpus of 268 oral self narratives completed with a questionnaire. [less ▲]

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See detailFunctional study of the Ser/Arg-rich splicing factor SRSF5a during zebrafish embryonic development
Joris, Marine ULg; Muller, Marc ULg; Motte, Patrick ULg

Poster (2014, June 05)

Nuclear pre-mRNA splicing is a key process regulating gene expression in eukaryotes. Splicing consists in the removal of introns and the joining of exons within a dynamic macromolecular complex called the ... [more ▼]

Nuclear pre-mRNA splicing is a key process regulating gene expression in eukaryotes. Splicing consists in the removal of introns and the joining of exons within a dynamic macromolecular complex called the spliceosome, which consist of five small nuclear ribonucleoproteins (snRNPs) and numerous non snRNPs proteins (1). Amongst these non snRNPs proteins, the SR proteins family constituted an important group of splicing factors that are involved in constitutive and alternative splicing (2,3). SR proteins are structurally related as they are characterized by one or two RNA-recognition motifs (RRMs) in N-ter and a C-terminal domain enriched in dipeptide Ser/Arg. Phylogenetic inference using the RRM domain allowed us to identify 13 encoding genes for SR proteins in the vertebrate model organism, Danio rerio. The Zebrafish is increasingly recognized as a powerful model for the study of vertebrate embryonic development in a physiological context. The roles of SR splicing factors during animal cell differentiation and development are largely unknown. The aim of the present research is to investigate SR proteins functions during zebrafish development by using molecular and genetic approaches. In this study, we investigated the role of the SR splicing factor SRSF5a. The expression profile was determined by in situ hybridization at 24, 48 and 72 hours post-fertilization and showed SRSF5a expression mainly in brain, retina and pharyngeal arches at these stages. Furthermore, SRSF5a knock-down by morpholinos microinjection strongly suggests an important role of this specific splicing factor during eyes and brain development. In order to gain insight into the molecular function of SRSF5a, we analysed control and morphant transcriptomes using high throughput RNA sequencing. Finally, we use a complementary approach to morpholinos and generate SRSF5a mutant fishes using TALENs (Tal effector nucleases)(4,5). 1. Wahl MC, Will CL, & Luhrmann R (2009) The spliceosome: design principles of a dynamic RNP machine. Cell 136(4):701-718. 2. Long JC & Caceres JF (2009) The SR protein family of splicing factors: master regulators of gene expression. Biochem J 417(1):15-27. 3. Graveley BR (2000) Sorting out the complexity of SR protein functions. RNA 6(9):1197-1211. 4. Moore et al. (2012) Improved Somatic Mutagenesis in Zebrafish Using Transcription Activator-Like Effector Nucleases (TALENs). Plos One 120(1):1-12. 5. Cade et al (2012) Highly efficient generation of heritable zebrafish gene mutations using homo- and heterodimeric TALENs. Nucleic acid research Vol 40, No 16:8001-8010. [less ▲]

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See detailDesign and synthesis of high-affinity ligands of AMPA receptors and study of their Fluorine-18 radiolabeling
Deverdenne, François ULg; Goffin, Eric ULg; Plenevaux, Alain ULg et al

Poster (2014, June 05)

The AMPA subtype of glutamatergic receptors is the main actor in the excitatory neurotransmission in the mammalian central nervous system. These receptors are involved in the expression and the ... [more ▼]

The AMPA subtype of glutamatergic receptors is the main actor in the excitatory neurotransmission in the mammalian central nervous system. These receptors are involved in the expression and the maintenance of the long-term potentiation, a phenomenon closely linked to cognitive and memorization processes. Based on experimental data collected in recent years, the use of AMPA potentiators seems to be an interesting approach in the treatment of cognitive deficits (e.g. Alzheimer disease), schizophrenia or depression. Such AMPA signal potentiation could be mediated by positive allosteric modulators (PAMs) of the AMPA receptors, a class of compounds able to produce a fine signal tuning in the presence of the endogenous ligand in the synapse, providing less toxicity than direct agonists. With this approach, the laboratory of Medicinal Chemistry of Liège university developed many series of AMPA potentiators , among which 1,2,4-benzothiadiazine 1,1-dioxides (BTDs). In order to better understand the in vivo mapping of AMPA receptors and its evolution in neurological diseases, the present work aims at developing the design and the synthesis of BTDs positive allosteric modulators radiolabeled with a fluorine-18 atom. Based on previously synthesized series in this field, we investigate the synthesis of a new class of high-affinity AMPA potentiators characterized by the presence of a fluorine atom at selected positions on the structure of the AMPA potentiators. Thanks to in vitro pharmacological evaluations, we will further determine the best candidates for their fluorine-18 radiolabeling. [less ▲]

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See detailApproche socio-écologique: arrangements de la complexité
Absil, Gaëtan ULg

Conference (2014, June 04)

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See detailLo stato di necessità, invenzione moderna o romana?
Gerkens, Jean-François ULg

Conference (2014, June 04)

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See detailL'épaule un carrefour complexe
WANG, François-Charles ULg; LOZZA, Alessandro

Conference (2014, June 04)

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See detailRelations between negative symptomatology and executive measures in schizophrenia.
Laloyaux, Julien ULg; Guettafi, Yassine; Dessart, Gregory et al

Poster (2014, June 03)

Introduction: Negative symptomatology and cognitive impairments are core features of persons diagnosed with schizophrenia that have a major negative impact on everyday life functioning. Further, some ... [more ▼]

Introduction: Negative symptomatology and cognitive impairments are core features of persons diagnosed with schizophrenia that have a major negative impact on everyday life functioning. Further, some authors (Konstantakopoulos et al., 2011) have suggested that negative symptoms and executive functions might represent different manifestations of the same syndrome, but this relation remains poorly understood. Objective: The objective was to explore relations between negative symptomatology (and in particular apathy) and executive functions in persons diagnosed with schizophrenia. Method: Twenty-seven individuals diagnosed with schizophrenia were evaluated with an extensive executive battery in addition to several measures of negative symptomatology (including specific measures of apathy) and real world functioning. Results: Results revealed that apathy was significantly related to measures of initiation (i.e. verbal fluency) and everyday life functioning. Moreover, more general measures of negative symptomatology were significantly related to multitasking abilities and cognitive flexibility. Discussion: In this study, we assessed the relations between negative symptomatology and executive measures. The results confirmed the links between these constructs, thus suggesting a common neural substrate. Conclusion: Based on results from the present study, executive dysfunctions and negative symptomatology may be seen as representing different manifestations of the same syndrome. [less ▲]

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See detailUn chiffre en débat. Controverse autour de la dette wallonne
Piron, Damien ULg

Conference (2014, June 03)

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See detailElectrical characterization of pGeSn/nGe diodes
Baert, Bruno ULg; Gupta, Somya; Gencarelli, Federica et al

Conference (2014, June 03)

I-V characteristics of pGeSn/nGe diodes have been measured and show very good properties. Simulations of the same structure are able to reproduce most of the observed behavior and point to the ... [more ▼]

I-V characteristics of pGeSn/nGe diodes have been measured and show very good properties. Simulations of the same structure are able to reproduce most of the observed behavior and point to the predominating influence of parameters such as the band gap energy of the GeSn layer. C-V characteristics showing little frequency dependence have also been measured, and their analysis for the determination of the carrier concentration is confirmed by simulations. More investigations, including the effect of temperature and other defects at the interface or in the bulk of either layers are still required in order to explain some of the observed behaviors, notably the reverse saturation current. [less ▲]

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See detailSIMPLIFIED SEISMIC ANALYSIS OF LOCK GATES
Buldgen, Loïc ULg; Degée, Hervé ULg; Lesourne, Hervé et al

in PIANC 2014 Conference (2014, June 02)

The paper deals with the seismic design of lock gates. When such structures are submitted to an earthquake, the water contained in the chamber is responsible for an additional hydrodynamic pressure acting ... [more ▼]

The paper deals with the seismic design of lock gates. When such structures are submitted to an earthquake, the water contained in the chamber is responsible for an additional hydrodynamic pressure acting on the gate. This one is the sum of three different parts, respectively called the convective, rigid and flexible contributions. The two first ones have already been extensively studied in the literature, but the flexible part is more difficult to assess as it is largely influenced by the coupling occurring between the fluid and the gate. To overcome this difficulty, it is of course possible to use finite elements software, but doing so is not always convenient. This is why some research have been undertaken to provide a rapid way for approximating the flexible pressure on lock gates. This is achieved by applying the analytical approach that is shortly presented in this paper. As a matter of validation, the results obtained through this simplified procedure are compared to numerical solutions. The agreement between both of them is found to be satisfactory. [less ▲]

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See detailRay tracing enhancement for space thermal analysis: isocell method
Jacques, Lionel ULg; Masset, Luc ULg; Kerschen, Gaëtan ULg

in Sarler, Bozidar; Massaroti, Nicola; Nithiarasu, Perumal (Eds.) Third International Conference on Computational Methods for Thermal Problems (2014, June 02)

The finite element method (FEM) is widely used in mechanical engineering, especially for space structure design. However, FEM is not yet often used for thermal engineering of space structures where the ... [more ▼]

The finite element method (FEM) is widely used in mechanical engineering, especially for space structure design. However, FEM is not yet often used for thermal engineering of space structures where the lumped parameter method is still dominant. Radiative exchange factors (REFs) are usually computed through Monte Carlo ray-tracing. Due to the large number of elements composing a FE model, the computation of the REFs is prohibitively expensive. The developments of the new Isocell quasi-Monte Carlo ray tracing method are presented. The Isocell method enhances the uniformity of the generated quasi-random sequence of ray directions and leads to faster convergence. It is associated with different surface sampling to derive the REFs. The method is benchmarked against ESARAD, the standard ray-tracing engine for thermal analysis used in the European aerospace industry. Various geometries are used. In particular, one entrance baffle of the Extreme Ultraviolet Imager (EUI) instrument developed at the Centre Spatial de Liège in Belgium is used. The EUI instrument of the Solar Orbiter European Space Agency mission and will be launched in a Sun-centered 0.28 perihelion orbit in 2018. [less ▲]

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See detailComparison of Indicators to Evaluate the Resilience of Lab Scale Continuously Stirred Anaerobic Reactors Submitted to Biological Dysfunctions
Lemaigre, Sébastien; Adam, Gilles ULg; Goux, Xavier et al

Poster (2014, June 02)

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See detailLes déterminants de la désinsertion professionnelle
Mairiaux, Philippe ULg

Conference (2014, June 02)

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See detailHOLOCENE DUST RECORD IN A BELGIAN PEAT BOG: MULTIPROXY GEOCHEMICAL APPROACH
Allan, Mohammed ULg; gael, le roux; Fagel, Nathalie ULg et al

Conference (2014, June 01)

Ombrotrophic peatlands are unique environmental archives of natural and anthropogenic atmospheric dust deposition. Their surface layers are exclusively fed by atmospheric inputs. A peat bog core from ... [more ▼]

Ombrotrophic peatlands are unique environmental archives of natural and anthropogenic atmospheric dust deposition. Their surface layers are exclusively fed by atmospheric inputs. A peat bog core from Misten in Eastern Belgium southern covering the last 7500 years (dated by 210Pb and 14C methods) was investigated to reconstruct dust depostion based on a combination of the Rare Earth Elements (REE) and lithogenic elements concentrations, as well as Nd and Pb isotopes data. Nd isotope signature was used to decipher between local and distal dust supplies, the Pb isotopes to trace the antropogenic influences. Peat humification was used to evaluate hydroclimatic conditions. Dust fluxes show pronounced increase at 3200-2800BC, 600BC, AD600, 1000AD, 1200AD and from 1700 AD. Lead isotope signatures are consistent with local and regional contamination by coal combustion and smelting activities. The Nd values show large variability, between -5 and –13, identifying three major sources of dust: local soils, distal volcanic and desert particles. Our results are in agreement with atmospheric reconstructions from other continental archives, confirming that the Misten peat is a valid archive for dust deposition. The approach combining geochemical elementary content and isotope data in ombrotrophic peat allows to decipher between dust flux changes related to human and climate forcing. [less ▲]

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See detailDe la matière à l'espace: une voie d'intégration numérique et matérielle
Delvaux, Frederic ULg; Bianchi, Romuald ULg; Jancart, Sylvie ULg

in Kubicki, Sylvain; Halin, Gilles; Bignon, Jean-CLaude (Eds.) Scan 14 séminaire de conception architecturale numérique : Interaction(s) des maquettes numériques (2014, June 01)

From a collaboration of formal and architectural research between architect and artist, we present the summary of an experimental approach that illustrates the creation and construction of a functional ... [more ▼]

From a collaboration of formal and architectural research between architect and artist, we present the summary of an experimental approach that illustrates the creation and construction of a functional space, located at the borders of the sculpture and the architecture. We present a look at the method, according to a revised approach to digital modeling / re-design. This has been an exploratory approach through the study of three generic models of the form. We present the experimental method, the selection of relevant parameters in form finding coupled with the integration of material and physical data specific to the object. We also expose the benefits of this approach, its limitations and the possibilities it offers as a generic point of view. [less ▲]

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See detailFlanders Ahead… Wallonia Behind (But Catching Up). Reconstructing Communities through Science, Technology, and Innovation Policymaking
Charlier, Nathan ULg; Van Oudheusden, Michiel ULg

Conference (2014, June)

Abstract Drawing on a documentary analysis of two socio-economic policy programs, one Flemish (“Vlaanderen In Actie”; VIA), the other Walloon (“Marshall Plans”; MPs), and a discourse analysis of how these ... [more ▼]

Abstract Drawing on a documentary analysis of two socio-economic policy programs, one Flemish (“Vlaanderen In Actie”; VIA), the other Walloon (“Marshall Plans”; MPs), and a discourse analysis of how these programs are received in one Flemish and one Francophone quality newspaper, this paper illustrates how Flanders and Wallonia both seek to become top-performing knowledge-based economies (KBEs). The paper discerns a number of discursive repertoires, such as “Catching up,” which Flemish and Walloon policy actors draw on to legitimize or question the transformation of Flanders and Wallonia into KBEs. The “Catching up” repertoire places Flanders resolutely ahead of Wallonia in the global race towards knowledge, excellence, and science-driven innovation, but suggests that Wallonia may, in due course overtake Flanders as a top-competitive region. Given the expectations and/or fears that “Catching up” evokes among Flemish and Walloon policy actors, the repertoire serves these actors as a flexible discursive resource to make sense of, and shape, their collective futures, and thus their identities. By rendering explicit how Flanders and Wallonia each acquire a distinct identity through the global KBE, the paper underlines the simultaneity of, and the interplay between, globalizing forces and particularizing tendencies and illuminates the political, nation-building and identity-building functions of science, technology, and innovation. The paper starts from the following preliminary observations. While both the VIA plan and the MPs emphasize the need of transforming Flanders and Wallonia into KBEs in order meet the demands of globalization (OECD 1996), the plans adopt a different tone and stance. The Flemish plan repeatedly states the need of transforming Flanders into “a top region, not only in Europe, but in the world, particularly in the social and economic field” (VIA, 2006: 4). It also states that Flanders is already prosperous and already has many strengths, but that the welfare and prosperity of Flanders are “under threat” in a “challenging global economic environment” (2). The message is thus that Flanders is doing relatively well in the global economy, but that it must do even better if it is to maintain its competitive edge and its welfare. By contrast, the MP is framed from the perspective of Walloon recovery and “redressement.” Although the term “Marshall Plan” evidently brings to mind the European Recovery Program for rebuilding Western Europe after World War II, recovery also refers to the period of prosperity before the World Wars, when Wallonia was one of the most economically advanced industrial regions in Europe. The MP suggests that Wallonia’s glorious past (“le passé glorieux”) can be rewon, if the Walloons deploy every tool they can muster and work together to “relaunch” the Walloon economy (3). To incite joint action, the MP urges the Walloons to become the architects of their own fate. This aspiration is clearly expressed in the opening sentence of the first MP plan: “The federalization [of Belgium; by which is meant the regionalization of policy and competences] bestows the Walloons with political autonomy, which renders them responsible for their own destiny.” At the same time, this statement reads as a call to independence, as the Walloons are bestowed with political autonomy (by the Flemings, who have repeatedly pushed for the dismantling of Belgium as a unitary state). As the above excerpts from the Flemish and Walloon policy plans indicate, VIA and the MPs characterize a state of political and economic affairs, take position in relation to these affairs, and, most importantly, envision a prosperous future for the Flemish and Walloon region, respectively. The plans are thus driven by expectations, visions and values, as well as fears. They mobilize arguments, explanations, evaluations, descriptions and prescriptions, sometimes by drawing on tropes or stereotypes, anecdotes, and illustrations. As the plans also indicate, transforming Flanders and Wallonia into top KBE regions does not happen by itself. For instance, while the VIA plan describes Flemings as entrepreneurs, it also states that “we must dare to be entrepreneurial” (3). Similary, the MP urges Walloon citizens to change their “état d’esprit” or mindset, if economic growth is to ensue (3). Thus, identity construction and transformation are in order both in Flanders and in Wallonia. The above observations serve as starting points for our media analysis. As we want to know whether, and how, these particular conceptions of the nation/region are picked up in press reporting on STI policies, we ask the following interrelated questions: How are the Flemish (VIA) and Walloon STI policies (MPs) received in the Flemish and Francophone press? Do we discern in the press the same notions of identity as in the policy programs? Are these notions reproduced, problematized or transformed? If so, in what ways? What does this mean for Flemish and Walloon identity construction, and for the construction of “Belgium” at large? Recognizing the role of “institutions of power” (e.g. language, media, technologies) in articulating nationalism (Anderson 1991: 163; Billig 1995: 11), our analysis conceives of journalists and the press as potential policy agenda setters and opinion makers, as the press potentially reproduces and redefines political identities. As this paper will illustrate, the Flemish and Francophone press speak out on issues of collective identity and also offer various policymakers a platform to express their views on regional economic development, STI, and the state. Thus, from our perspective, policymaking is not only the prerogative of mandated policymakers, but of journalists and other opinion leaders (e.g. captains of industry) as well (Lenschow & Sprungk 2010). To enable analysis, we draw on a range of literatures, including science and technology studies, discourse analysis, and media analyses. Our approach is interpretive and interactionist, as it assumes that realities (e.g. identities, nations, as well as practices and materialities) are socially constructed rather than exist as objective phenomenon that can be discovered through empirical testing (Fischer 2003: 118). Hence, we ask how identity is created, structured, maintained, or conversely deconstructed, resisted, and challenged. Our aim is thus not to uncover an objective reality behind identity, but to understand how identities are collectively made and remade on a continuous basis. To this end, we draw on the notion of “coproduction” (Jasanoff 2006: 2) to empirically demonstrate how STI and nationalism are “coproduced” through technoscientific practices (Felt 2013). In what follows, we first present, discuss, and situate Flemish and Walloon STI policies in time and place, as a means of contextualizing the “nationalisms” inscribed in the VIA plan and MPs. Next, we present our methodological framework for discourse and media analysis, our data, and key findings. Upon drawing together these findings, we single out the storyline of “Catching up” as an important discursive backdrop against which processes of collective identity construction play out through STI policymaking and press reporting. We conclude by tying our findings into a broader discussion about the place of Belgium in Europe and the world, as nation states are constantly (re)defined in terms of their constituent segments and overarching structures, including the KBE. The paper’s topics resonate with the overall conference theme and specifically tie into the following conference strands: • Policy emergence, implementation, diffusion and transfer • National science policies and the global scientific enterprise • The multi-level governance of research and innovation and the challenge of co-ordination Keywords: Flanders, Identity, Knowledge-based economy, Science and technology policy, Wallonia. References Anderson, B. (1991), Imagined Communities. Reflection on the Origin and Spread of Nationalism. London, Verso. Billig, M. (1995), Banal Nationalism. London, Sage. Felt, U. (2013), “Keeping Technologies Out: Sociotechnical imaginaries and the formation of a national technopolitical identity,” Pre-print; Published by the Department of Social Studies of Science, University of Vienna, February 2013; http://sciencestudies.univie.ac.at/publications Fischer, F. (2003), Reframing Public Policy. Discursive Politics and Deliberative Practices. Oxford, UK, Oxford University Press. Flanders in Action (VIA); www.vlaandereninactie.be Jasanoff, S. 2006. The idiom of co-production. In: Jasanoff, S., Ed., States of Knowledge. The Coproduction of Science and Social Order. New York, Routledge, 1-12. Lenschow, A. & Sprungk, C. (2010), “The Myth of a Green Europe,” Journal of Common Market Studies, 48(1), 133-154. OECD (1996), The Knowledge Based Economy, OECD/GD, (96)102. Plan Marshall (MP); http://www.wallonie.be/fr/actualites/plan-marshall-2022 [less ▲]

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See detailApplication of hyperspectral Raman imaging to the analysis of a self-emulsifying drug delivery system (SEDDS).
Sacre, Pierre-Yves ULg; De Bleye, Charlotte ULg; Netchacovitch, Lauranne ULg et al

Poster (2014, June)

Self-emulsifying drug delivery systems (SEDDS) are mixtures of drug and excipients that undergo emulsification when exposed to water. This pharmaceutical form is used to enhance the oral absorption of ... [more ▼]

Self-emulsifying drug delivery systems (SEDDS) are mixtures of drug and excipients that undergo emulsification when exposed to water. This pharmaceutical form is used to enhance the oral absorption of poorly water-soluble drugs. The API is finely dispersed in the excipients and forms a solid solution increasing its dissolution rate. Hyperspectral Raman imaging is a powerful tool that combines both spectral and spatial information. It returns qualitative and quantitative information useful during the development or the characterization of pharmaceutical preparations. The studied formulation consisted of a BCS 2 API (high permeability, low solubility) dispersed in excipients mainly composed of Lauroyl macrogol-32 glycerides (>50%). Two different preparations were analyzed: 100% of API dissolved and 70% of API dissolved with 30% of API powder added to the formulation. The two formulations have therefore exactly the same qualitative and quantitative composition but different spatial distribution and dispersion of the API mimicking a problem during the process. First a confocal Raman microscopic analysis was performed to evaluate the solid state of the API in the formulations. Then, an evaluation of the particle size was performed. These results are important since they can affect the bioavailability of the API and therefore its activity. Beside the microscopic scale analysis, a macroscopic imaging quantitative PLS model has been developed. The method has been validated within +/- 10% acceptance limits following the total error approach. This validated quantitative model enables reliable quantitative analysis at the pixel level of Raman images providing meaningful chemical images. [less ▲]

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