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See detailÉdition et étude de Gerard du Frattre, compilation épique du XVIe siècle
Lambert, Adélaïde ULg

Poster (2017, May 23)

Présentation du projet de thèse de doctorat.

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See detailEffects of preference and sensory modality on behavioral reaction in patients with disorders of consciousness
Heine, Lizette ULg; Tillmann, Barbara; Hauet, Marjolaine et al

in Brain Injury (2017)

Background: Reliable evaluation of patients with unresponsive wakefulness syndrome (UWS) or in a minimally conscious state (MCS) remains a major challenge. It has been suggested that the expression of ... [more ▼]

Background: Reliable evaluation of patients with unresponsive wakefulness syndrome (UWS) or in a minimally conscious state (MCS) remains a major challenge. It has been suggested that the expression of residual cerebral function could be improved by allowing patients to listen to their favourite music. However, the potential effect of music on behavioural responsiveness, as well as the effect of preferred stimuli in other sensory modalities (e.g. olfaction), remain poorly understood. Objective: The aim of our study was to investigate the effect of sensory modality (auditory versus olfactory) and preference (preferred versus neutral) of the test stimuli on patients’ subsequent performance on the Coma Recovery Scale-Revised (CRS-R). Research design: Within-subject design because of inter-individual differences between patients. Methods and procedures: We studied four items from the CRS-R (visual pursuit using a mirror, auditory localization of the own name and two movements to command) in 13 patients (7 MCS; 6 UWS). Main outcomes and results: Auditory stimuli triggered higher responsiveness compared to olfactory stimuli, and preferred stimuli were followed by higher scores than did neutral stimuli. Conclusions: Findings suggest that preferred auditory stimuli at the bedside contribute to the expression of residual function and could improve the diagnostic assessment. [less ▲]

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See detailEssential oil of Tunisian plant: biopesticide applied in agricultural system
Ben Kaab, Sofiène ULg; ksouri, riadh; Jijakli, Haissam ULg

Conference (2017, May 23)

The use of plant-derived products in postharvest disease management may be a valid alternative to conventional chemical treatments (Pane et al., 2016). Unfavorable environmental conditions (such as salt ... [more ▼]

The use of plant-derived products in postharvest disease management may be a valid alternative to conventional chemical treatments (Pane et al., 2016). Unfavorable environmental conditions (such as salt and drought) increase production and accumulation of reactive oxygen species (ROS). Consequently, Tunisian plants have developed adaptive responses including the synthesis of specific bioactive molecules used for medical and nutritional purposes (Ksouri et al., 2012). In that context, the main objective of the present study was the identification of essential oils from Tunisian plants against the important plant pathogens, particularly in Europe. The study began with the selection of endemic medicinal plant suspected to present antimicrobial properties. The essential oil was extracted by hydrodistillation using a Clevenger type apparatus (with a yield of 1.2%). The chemical composition of the essential oil obtained by hydro-distillation from the aerial parts was analyzed by GC/MS. Therefore, antifungal activity was evaluated against Fusarium culmorum, Fusarium oxysporum and Penicillium italicum, using ELISA microplates with a blocked randomized design, as described previously (Kouassi et al., 2012). In addition, the essential oil was then tested for their herbicidal activities in pre-emergence and post-emergence assays against three weeds species. The chromatographic analysis showed a complex mixture where twenty compounds were identified accounting for 98.75 % of the total oil. Monoterpenes was represented by 71.73 %. The dominant monoterpenes are α Pinene (7.09%), 1,8-Cineole (54.6%) and Camphor (12.27%). Essential oil reduced significantly spores germination in a dose-dependent manner. Their fungistatic activity reached 100% at 0.6% against Fusarium oxysporum . In the dose response bioassay, the essential oil reduced seed germination rate of Phalaris minor, Sylibum marianum and Trifolium incanatum. Seedling growth was measured by shoot and root lengths at day 7. At 0.5%, essential oil reduced 100% seed germination. Post-emergence bioassays consisted in spraying essential oil at 3 concentrations (0.75, 2 and 3.4 %) at 2 leaves stage of three weeds species. Pelargonic acid was used as commercial positive control at 3.4%. At 0.75% and 2%, the essential oil do not show any sign of injury. However, only at 3.4 %, the spraying of essential oil showed visible injury ranging from wilting (after 1 day) and chlorosis (after 3 day) on Trifolium incanatum and Phalaris minor. After formulation, to enhance the distribution, the coverage and the penetration of the active molecules, the essential oil presented a high herbicidal activity. In conclusion, this work allowed to open new perspectives on the application of Tunisian essential oil as Novel biocontrol strategies against damageable plant pathogens and weeds. [less ▲]

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See detailDesign of polyphosphoester-based drug delivery systems by efficient thiol-ene reaction
Riva, Raphaël ULg; Vanslambrouck, Stéphanie; Ergül, Zeynep ULg et al

Poster (2017, May 23)

Thanks to their biocompatibility, biodegradability and their structure similar to natural biomacromolecules, polyphosphoesters (PPE) are appealing polymers for biomedical applications. In contrast to ... [more ▼]

Thanks to their biocompatibility, biodegradability and their structure similar to natural biomacromolecules, polyphosphoesters (PPE) are appealing polymers for biomedical applications. In contrast to polyesters, PPE properties and functionality are easily tuned via the chemical nature of the lateral chains. To enhance the drug loading capacity of PPE-based micelles used as carriers for the delivery of poorly soluble drugs, an efficient strategy to increase the lipophilicity of the PPE block of polyethylene oxide (PEO)-b-PPE amphiphilic copolymers has been investigated. A PEO-b-PPE copolymer bearing pendant vinyl groups along the PPE block was synthesized and then modified by thiol-ene click reaction with thiols bearing either a long linear alkyl chain (dodecyl) or a tocopherol moiety. Ketoconazole was used as model for hydrophobic drugs. Comparison of the loading contents and release profiles with PEO-b-PPE bearing shorter pendant groups is presented evidencing the key role of the structure of the pendant group on the PPE backbone. Finally, the low cytotoxicity of these novel PEO-b-PPE copolymers was also demonstrated. The tocopherol derivative was evidenced as particularly promising for drug delivery systems. [less ▲]

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See detailQuantification of model uncertainties
Achenbach, Marcus; Gernay, Thomas ULg; Morgenthal, Guido

Scientific conference (2017, May 23)

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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 detailCis-perturbation of cancer drivers by the HTLV-1/BLV proviruses is an early determinant of leukemogenesis
Rosewick, Nicolas; Durkin, Keith ULg; Artesi, Maria ULg et al

in Nature Communications (2017), 8

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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)

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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)

Detailed reference viewed: 29 (5 ULg)