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See detailStudy of VOCs in the interaction between Banana and Foc TR4
Berhal, Chadi ULg; De Clerck, Caroline ULg; LEVICEK, Carolina et al

Poster (2017, May 23)

Banana fruit (Musa sp.) ranks fourth in term of worldwide production, and has economical and nutritional key values. The popular and most dominant variety of the dessert banana group is the Cavendish ... [more ▼]

Banana fruit (Musa sp.) ranks fourth in term of worldwide production, and has economical and nutritional key values. The popular and most dominant variety of the dessert banana group is the Cavendish variety. Nowadays, the Cavendish is endangered by the newly emergent race of the Panama disease, caused by the fungal pathogen Fusarium oxysporum f.sp. cubense TR4 (Foc TR4). Despite the importance of the Volatile Organic Compounds (VOCs), which are secondary metabolites with a high vapour pressure, in their utility in the plant protection processes, they were never documented as a way to manage this disease on Cavendish. Thus, the aim of this PhD thesis is to study the VOCs in the specific interaction Cavendish/Foc TR4, as a way to manage this threat. Based on the work previously done with other plants at Gembloux Agro-Bio Tech/University of Liège/Belgium, a protocol was optimized for the extraction of the banana plant’s VOCs. And in parallel, models of in-vitro and in-vivo inoculations are under development, in order to distinguish the root zone from the upper part of the plant in the study. The results of the first analysis showed that the majority of the Cavendish VOCs belongs to the terpenes group, as well as ketones and an organic ester. The identified key VOCs of the interaction will be subject to toxicity tests, in order to determine their effect on the development of the plant and the pathogen. The banana plant is a staple food for more than 400 Million people in the world, while this disease persists as a major threat for its production, and this original study could contribute to the fight against this threatening disease. [less ▲]

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See detailA surprising and dramatic neuroendocrine-immune phenotype of mice deficient in Growth Hormone-Releasing Hormone (GHRH)
Farhat, Khalil; Bodart, Gwennaëlle ULg; RENARD, Jeanne de Chantal ULg et al

Poster (2017, May 23)

In the framework of close interactions between the immune and neuroendocrine systems, Growth Hormone (GH) has been proposed to exert significant effects on the immune system, but there is not yet a ... [more ▼]

In the framework of close interactions between the immune and neuroendocrine systems, Growth Hormone (GH) has been proposed to exert significant effects on the immune system, but there is not yet a consensus about GH immunomodulatory properties. These studies investigated the immune and anti-infectious response of dwarf Ghrh-/- mice presenting a severe deficiency of the GHRH/GH/IGF-1 axis. In basal conditions, thymic parameters and T-cell responses of Ghrh-/- mice were not severely affected but a constant B-cell lymphopaenia was observed. Thus, we investigated vaccine and anti-infectious responses of Ghrh-/- mice toward Streptococcus pneumonia, a B-dependent pathogen, Ghrh-/- mice were unable to trigger production of specific IgM and IgG against serotype 1 pneumococcal polysaccharide (PPS) after vaccination with either native PPS (Pnx23) or protein-PPS conjugate (Prev-13) vaccines. These vaccines both include the serotype 1 (our S.pneumoniae strain) and provide an effective protection in mice. A short GH supplementation to Ghrh-/- mice (1 daily injection of 1 mg/kg GH for 4 weeks) restored IgM and IgG response to Pnx23 vaccine but not to Prev-13. This suggests that GH could exert distinct impacts upon spenic areas. Furthermore, after intranasal instillation of a non-lethal dose (defined by the full clearance by WT C57BL/6 mice after 24h) of serotype 1 S.pneumoniae, Ghrh-/- mice exhibited a dramatic susceptibility. This was proved by a marked time-dependent increase in pulmonary bacterial, a septicemia already 24h after infection and a survival limit of 72h. We also observed a dramatic decrease in lung B- and T-cell populations and an increase in proportion of inflammatory macrophages. By contrast, wild-type and heterozygote mice completely cleared S.pneumoniae infection after 24h. In conclusion, our data show without ambiguity that the somatotrope GHRH/GH/IGF-1 axis plays an important and unsuspected role in defense against S.Pneumoniae. [less ▲]

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See detailPrecision synthesis and characterization of novel functional polymers
Scholten, Philip ULg; Debuigne, Antoine ULg; Demarteau, Jérémy ULg et al

Poster (2017, May 23)

Among controlled radical polymerisation techniques, cobalt-mediated radical polymerisation (CMRP) has proven to be a valuable alternative in polymerising unreactive and unconjugated monomers of many ... [more ▼]

Among controlled radical polymerisation techniques, cobalt-mediated radical polymerisation (CMRP) has proven to be a valuable alternative in polymerising unreactive and unconjugated monomers of many different monomer classes under mild conditions, including α-olefins. In a reversible deactivation mechanism, a cobalt complex reversibly traps the active growing chains and converts them into dormant species, avoiding side reactions and allowing for a controlled polymerisation. A fine control over the architecture is possible and allows to synthesise a large diversity of unprecedented block and alternating copolymers. Furthermore, functionalisation of the α- and ω-chain ends is now also possible. In this poster, the polymerization of different vinyl monomers using CMRP has been investigated to design highly functional materials under mild experimental conditions. The copolymerisation behaviour of these novel monomers was examined, and the structure and thermal properties of the new copolymers were investigated. [less ▲]

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See detailLoi de comportement pour les argiles naturelles
Ahayan, Sanae ULg; Cerfontaine, Benjamin ULg; Collin, Frédéric ULg

Scientific conference (2017, May 23)

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See detailControlled synthesis of fluorinated copolymers via cobalt-mediated radical copolymerization of perfluorohexylethylene and vinyl acetate
Demarteau, Jérémy ULg; Améduri, Bruno; Ladmiral, Vincent et al

in Macromolecules (2017), 50(10), 3750-3760

Designing novel polyfluoropolymer architectures is attractive for the development of new applications, such as advanced coatings, purification membranes, or materials for energy. Nevertheless, controlling ... [more ▼]

Designing novel polyfluoropolymer architectures is attractive for the development of new applications, such as advanced coatings, purification membranes, or materials for energy. Nevertheless, controlling the radical polymerization of fluoroalkenes is very challenging due to the high reactivity of the propagating fluorinated macroradicals. This study aims at exploring the controlled copolymerization of perfluoro- hexylethylene (PFHE) and vinyl acetate (VAc) in order to prepare a range of well-defined statistical poly(PFHE-stat-VAc) copolymers with different compositions. Cobalt-mediated radical polymerization demonstrated to be active at 40 °C starting from an alkylcobalt(III) initiator, and copolymers with a fluorinated monomer content as high as ca. 80 wt % were successfully prepared. Reactivity ratios were determined to be rVAc = 0.18 and rPFHE = 0 at 40 °C and emphasized a clear tendency for alternation. Unprecedented PFHE/VAc containing block copolymers were also prepared via a single-step approach or through sequential copolymerizations. Finally, hydrolysis of the pendant ester groups of these copolymers led to the corresponding fluorinated copolymers bearing vinyl alcohol (VOH). A preliminary solution behavior study, carried out by dynamic light scattering and transmission electron microscopy on block copolymers composed of PFHE and VAc or VOH units, evidenced a marked amphiphilicity of the copolymer composed of an extremely hydrophobic PFHE block associated with a highly hydrophilic PVOH segment. [less ▲]

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See detailStudy of volatile organic compounds active against barley pathogens
De Clerck, Caroline ULg; Kaddes, Amine ULg; Fiers, Marie et al

Conference (2017, May 23)

Detailed reference viewed: 23 (2 ULg)
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See detailÉvaluer les performances des étudiants à l’Université
Detroz, Pascal ULg

Scientific conference (2017, May 23)

Évaluer des étudiants à l’université ou en haute école est une lourde responsabilité. À travers les notes distribuées, ce sont des rêves, des aspirations, un parcours universitaire, une vie ... [more ▼]

Évaluer des étudiants à l’université ou en haute école est une lourde responsabilité. À travers les notes distribuées, ce sont des rêves, des aspirations, un parcours universitaire, une vie professionnelle qui se constituent ou qui, dans certains cas plus négatifs, sont altérés ou détruits. L’édumétrie s’est, depuis plus de 70 ans, intéressée à la qualité des examens et des épreuves scolaires. Avec une conclusion redondante et sans concession : les biais dans la mesure récoltée, autrement dit dans le score attribué aux étudiants, sont nombreux et variés et la part d’erreur y est signifiante. Il y a donc des enjeux sociaux importants - d’équité notamment - à proposer des dispositifs d’évaluation robustes reflétant avec exactitude les capacités réelles des étudiants. Ces dernières années, le travail des évaluateurs s’est considérablement complexifié. L’enseignement universitaire a subi une profonde mutation. Sous l’impulsion d’exigences sociales nouvelles, un nouveau vocable s’est érigé en mantra dans nos institutions. Qu’ils s’agissent de compétences, de performances complexes, de soft skills, d’apprentissages authentiques, tous ces concepts ont pour point commun de viser un apprentissage holistique, contextualisé, intégré, multidisciplinaire. Toutes ces évolutions, souvent très pertinentes, se confrontent toutefois aujourd’hui aux limites de nos connaissances dans le domaine de l’évaluation. Certes les modèles de l’évaluation changent peu à peu. Dans les écrits, la focale porte aujourd’hui sur une évaluation porteuse de sens, émancipatrice, axée sur une rétroaction favorisant les apprentissages, partenariale, prenant en compte la complexité des apprentissages visés par l’enseignement. C’est une évolution saine et utile. Mais dans le contexte de l’enseignement supérieur, dans lequel l’avenir des étudiants dépend de la note finale, on peut s’inquiéter en observant que ces modèles en gestation se structurent sans préoccupation particulière quant à la qualité de la mesure. Autour de ces thématiques, nous proposerons un modèle structurant permettant d’augmenter la qualité des dispositifs d’évaluation, y compris dans ces contextes émergents. [less ▲]

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See detailCorrection de questions à réponses ouvertes: le logiciel SQORE
Crahay, Vinciane ULg; Bonnet, Pierre ULg

Conference (2017, May 23)

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See detailLaccase detoxification of lignocellulose hydrolysate
Cornet, Iris; Soti, Valentin; Richel, Aurore ULg et al

Poster (2017, May 22)

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See detailDEVELOPPEMENT D’UN MODELE DE SYSTEME DE CLIMATISATION AUTOMOBILE MULTI-EVAPORATEURS
Gillet, Thomas ULg; Gendebien, Samuel ULg; Lemort, Vincent ULg et al

Conference (2017, May 22)

La modélisation numérique d’un climatiseur d’automobile multi-évaporateurs, composé de deux évaporateurs et d’un refroidisseur d’eau, a été réalisée à l’aide du logiciel LMS Imagine.Lab Amesim® 1D avec le ... [more ▼]

La modélisation numérique d’un climatiseur d’automobile multi-évaporateurs, composé de deux évaporateurs et d’un refroidisseur d’eau, a été réalisée à l’aide du logiciel LMS Imagine.Lab Amesim® 1D avec le fluide frigorigène R-134a. Un banc d’essai capable de reproduire les conditions extérieures d’un climatiseur automobile a été conçu afin de tester l’architecture de cette machine multi-évaporateurs avec le fluide frigorigène R-1234yf. Les bilans thermiques des premiers résultats expérimentaux sont analysés et présentés. Afin d’illustrer la complexité du contrôle d’une telle architecture en régime dynamique, l’activation d’une vanne électromagnétique dans la boucle batterie du banc d’essais est présentée. Enfin, une perturbation de type échelon a été générée dans le modèle numérique afin de vérifier si les phénomènes transitoires observés expérimentalement sont reproduits. [less ▲]

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See detailPuzzling Out Synaptic Vesicle 2 Family Members Functions
Bartholomé, Odile ULg; Van Den Ackerveken, Priscilla ULg; Sanchez Gil, Judit ULg et al

in Frontiers in Molecular Neuroscience (2017)

Detailed reference viewed: 3 (1 ULg)
See detailUnprecendeted fluoroalkene-based copolymers through cobalt-mediated radical polymerization
Demarteau, Jérémy ULg; Ameduri, Bruno; Ladmiral, Vincent et al

Poster (2017, May 22)

The precision design of fluorinated copolymers is challenging but also attractive for future developments in a wide range of applications involving fluoropolymers, such as advanced coatings or ... [more ▼]

The precision design of fluorinated copolymers is challenging but also attractive for future developments in a wide range of applications involving fluoropolymers, such as advanced coatings or purification membranes. In particular, controlling the radical polymerization of fluoroalkenes remains extremely difficult because of the high reactivity of these monomers due to the lack of resonance stabilizing group on their double bond. Herein, Cobalt-Mediated Radical Polymerization (CMRP) was used to efficiently control the bulk copolymerization of perfluorohexylethylene (PFHE) and vinyl acetate (VAc). Well-defined statistical poly(PFHE-stat-VAc) copolymers with different compositions (0 < FPFHE < 0.5) were obtained accordingly. In some cases, fluorinated monomer content as high as 80 % by weight were achieved. Reactivity ratios were determined (rVAc = 0.18 and rPFHE = 0) and emphasized a clear tendency for alternation. Single step approach and sequential polymerization were assessed for the synthesis of novel PFHE/VAc block copolymers. Finally, the acidic hydrolysis of the pendant ester groups of these block copolymers led to the formation of novel highly amphiphilic macromolecules bearing a PVOH hydrophilic segment and a hydrophobic PFHE-based block. [less ▲]

Detailed reference viewed: 20 (2 ULg)
See detailProtein encapsulation into nanostructured CaCO3 microparticles templated by PEO-b-polyphosphoester using a supercritical CO2 process
Ergül, Zeynep ULg; Debuigne, Antoine ULg; Calvignac, Brice et al

Poster (2017, May 22)

The use of calcium carbonate microparticles is becoming more and more attractive in biomedical applications as proteins carriers for their controlled delivery in the body. We investigate the protein ... [more ▼]

The use of calcium carbonate microparticles is becoming more and more attractive in biomedical applications as proteins carriers for their controlled delivery in the body. We investigate the protein encapsulation by in situ precipitation of CaCO3 particles prepared by a process based on supercritical CO2 and using a new type of degradable well-defined double hydrophilic block copolymer composed of poly(ethylene oxide) and polyphosphoester block with an affinity for calcium like poly(phosphotriester)s bearing pendent carboxylic acids on each repeating monomer unit which evidenced an efficient structure for templating the formation of CaCO3 leading to unprecedented small-sized particles. Lysozyme was chosen as a model for therapeutic protein for its availability and ease of detection. It was found that by this green process, loading into the CaCO3 microparticles with a diameter about 2 μm can be obtained as determined by scanning electron microscopy. A protein loading up to 6.5% active lysozyme was measured by a specific bioassay (Micrococcus lysodeikticus). By encapsulating fluorescent-labelled lysozyme (lysozyme-FITC), the confocal microscopy images confirmed its encapsulation and suggested a core–shell distribution of lysozyme into CaCO3. [less ▲]

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See detailSynthesis of cross-linked P(HEMA) particles in supercritical carbon dioxide for protein delivery
Parilti, Rahmet ULg; Howdle, Steven M.; Jérôme, Christine ULg

Poster (2017, May 22)

This project aims to develop a novel one-pot strategy to obtain well-defined cross-linked particles able to carry peptides/proteins in their core, as along with targeting and/or imaging agents on their ... [more ▼]

This project aims to develop a novel one-pot strategy to obtain well-defined cross-linked particles able to carry peptides/proteins in their core, as along with targeting and/or imaging agents on their surface. In addition to this objective, polymerisations will be carried out in supercritical carbon dioxide (scCO2), which confers environmentally benign features to the process. Here, we investigate the feasibility of free radical dispersion polymerizations of 2-hydroxyethyl methacrylate (HEMA) in scCO2. In order to ensure the successful dispersion in scCO2 novel diblock CO2-philic surfactants are employed. These diblock surfactants are formed from two different segments, a CO2-phobic block which has an affinity to the growing particles and a second CO2-philic block that ensures surfactant solubility. [less ▲]

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See detailPERFORMANCES D’UNE MINI POMPE À CHALEUR RÉVERSIBLE FONCTIONNANT SUR L’AIR EXTRAIT : ÉTUDE NUMERIQUE ET EXPERIMENTALE
Ransy, Frédéric ULg; Gendebien, Samuel ULg; Lemort, Vincent ULg

Poster (2017, May 22)

La majeure partie de la consommation d’énergie des immeubles à appartement dits « basse énergie » est liée à la production d’eau chaude sanitaire et aux pertes par ventilation. De plus, ces immeubles sont ... [more ▼]

La majeure partie de la consommation d’énergie des immeubles à appartement dits « basse énergie » est liée à la production d’eau chaude sanitaire et aux pertes par ventilation. De plus, ces immeubles sont soumis à un risque de surchauffe non négligeable en été. Afin de minimiser leur consommation d’énergie, les systèmes HVAC utilisés dans ces bâtiments se doivent d’être performants et multitâches. Dans cette optique, l’Université de Liège teste actuellement une mini-pompe à chaleur réversible sur air extrait. Cet article présente les résultats expérimentaux obtenus en laboratoire et démontre quelles sont les variables qui influencent les performances de cette machine. Un modèle polynomial est également proposé. [less ▲]

Detailed reference viewed: 14 (2 ULg)