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See detailComparison of two laboratory-scale ensiling methods to assess effect of reducing sugars
Herremans, Sophie ULg; Decruyenaere, Virginie; Beckers, Yves ULg et al

Poster (2017, February 07)

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See detailLoss of transfer RNA U34 modifying enzymes impairs hematopoietic stem and progenitor cell differentiation and function
Rosu, Adeline ULg; Bai, Qiang ULg; Ramery, Eve ULg et al

Poster (2017, February 03)

Hematopoietic stem and progenitor cells (HSPCs) require fine-tuned protein translation for their normal maintenance and function. Conserved modifications of the wobble uridine base (U34) in transfer RNAs ... [more ▼]

Hematopoietic stem and progenitor cells (HSPCs) require fine-tuned protein translation for their normal maintenance and function. Conserved modifications of the wobble uridine base (U34) in transfer RNAs catalyzed by the Elongator complex are required for optimal protein translation efficacy and fidelity, but their biological importance in mammalian stem and progenitor cells remains largely unexplored. Here, we studied the impact of loss of activity of the catalytic subunit Elp3 of Elongator on HSPC differentiation and function. Hematopoietic-cell-specific depletion of Elp3 in conditional knockout mice resulted in shortened lifespan associated with hematopoietic failure and lymphoma development. Elp3 deletion caused apoptosis of specific bone marrow multipotent progenitors and blocked differentiation of committed progenitors, resulting in blood and bone marrow pancytopenia. In contrast, Elp3-deficient hematopoietic stem cells (HSCs) expanded with age and did not exhaust throughout life, although they were defective in reconstituting hematopoiesis in competitive transplantation assays. Mechanistically, loss of Elp3 did not result in detectable alterations in global protein synthesis rates in any HSPC subset. Rather, Elp3-deficient HSPCs displayed enhanced activity of the stress integrator and apoptosis and cell cycle regulator p53. Thus, this study supports the notion that Elongator activity is required in distinct HSPC subsets to avoid aberrant p53 activation, which otherwise results in discrete loss of function phenotypes in HSCs and downstream progenitors. [less ▲]

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See detailModelling BMP-2 carrier device for bone tissue engineering application
Manhas, Varun ULg; Carlier, Aurelie; Geris, Liesbet ULg

Poster (2017, February 01)

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See detailMyoferlin, a new autophagy player in pancreatic cancer cells
Rademaker, Gilles ULg; Hennequière, Vincent ULg; Peixoto, Paul et al

Poster (2017, February 01)

Despite intensive research, Pancreatic Ductal Adenocarcinoma (PDAC) remains one of the deadliest forms of cancer. Early-stage of the disease is clinically silent and the diagnosis of the disease is mostly ... [more ▼]

Despite intensive research, Pancreatic Ductal Adenocarcinoma (PDAC) remains one of the deadliest forms of cancer. Early-stage of the disease is clinically silent and the diagnosis of the disease is mostly made at an advanced stage. This late diagnosis contributes to one of the lowest 5-year survival rates (<5%). Today, PDAC are treated by surgery and/or adjuvant therapy, increasing only slightly the median survival of the patients. There is therefore an urgent need to develop new effective therapies for PDAC patients. PDAC are characterized by a high autophagic activity involved in its chemoresistance. Recently, key regulatory proteins controlling the metabolic reprogramming of PDAC cells were identified. By governing both autophagic flux and lysosomal catabolism, these proteins support the efficient processing of cargo from autophagy, providing PDAC cells with access to critical sources of nutrients. Interestingly, the high autophagy level in PDAC correlates with a poor patient outcome. Myoferlin, a member of the ferlin family overexpressed at protein level in different cancer types including PDAC, is a transmembrane protein able to bound to phospholipids and described to play an important function in membrane fusion. This characteristic invited us to investigate whether myoferlin could participate to autophagy, a process involving membrane fusion. Panc-1 cell line was used as a model of PDAC basal autophagy. Myoferlin expression was silenced using interfering RNA technology. Autophagosome abundance was evaluated by LC3-II western-blot and flow cytometry. Results indicated a significant increase in autophagosome abundance 48 h after myoferlin-silencing. This increase could arise from an increase of autophagy initiation or from an inhibition of autolysosome degradation. Using autophagy inhibitors, autophagic flux was evaluated by LC3-II and p62 western-blot after myoferlin-silencing. Results suggested a blockade in the autophagic process, impairing termination and autophagosome degradation by lysosome activity. Knowing the affinity of myoferlin for phospholipids, we wonder if this protein could interact with the phosphatidylethanolamine-conjugated LC3-II protein. Proximity-ligation assay suggested a close interaction between myoferlin and LC3. These results evoke an unexplored and undescribed role for myoferlin in autophagy. Understanding the involvement of myoferlin in this rediscovered biological process could give new clues in the development of new therapeutic strategy. [less ▲]

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See detailIdentification of proteins discriminating inflammation induced dysplasia from simple inflammation in ulcerative colitis by laser capture microdissection and label free proteomics – a pilot study
Merli, Angela-Maria ULg; QUESADA-CALVO, Florence ULg; MASSOT, Charlotte ULg et al

Poster (2017, February 01)

Chronic colonic inflammation in ulcerative colitis (UC) may induce dysplasia, which can itself progress and transform into neoplasia. Diagnosis of dysplasia in UC remains difficult particularly when ... [more ▼]

Chronic colonic inflammation in ulcerative colitis (UC) may induce dysplasia, which can itself progress and transform into neoplasia. Diagnosis of dysplasia in UC remains difficult particularly when tissue inflammation is present. The aim of this retrospective pilot study was to highlight proteins specifically associated with inflammation induced dysplasia in UC. We performed a pilot experiment on 15 Formalin-Fixed, Paraffin-Embedded (FFPE) samples isolated from 5 cases of UC patients with a Polypoïd Pedunculated dysplasia (UC-PP). We compared the proteomes of the UC-PP, the inflammatory (UC-I) and the normal (UC-NL) tissues of each patient. We performed Laser Capture Microdissection (LCM) in order to collect only epithelial cells, avoiding inflammatory infiltrating ones. Label free proteomic analysis using a 2D-nanoUPLC coupled with a hybrid Quadrupole-Orbitrap was applied, as well as differential analysis on the paired samples. Immunohistochemistry (IHC) characterisation of one of the selected proteins of interest was used for validation. Out of 985 quantified proteins, 7 were found significantly more abundant in UC-PP compared to UC-I tissues, with 6 being only detected in UC-PP using proteomics. One of these is Solute Carrier Family 12 member 2 (SLC12A2), also known as Na-K-2Cl co-transporter 1 (NKCC1), a protein involved in ionic balance, in T-cell migration promotion and in some features involved in cancer development like proliferation, migration or invasion. IHC results obtained were in correlation with proteomic results and showed that SLC12A2 was more abundant in UC-PP tissue than in UC-I and UC-NL tissues, with a signal clearly delimiting the dysplastic region from the surrounding inflammatory tissue. This pilot experiment shows a different proteomic profile in inflammation-associated dysplasia and simple inflammation. This should be replicated using other types of dysplasia in IBD. SLC12A2 could be a potential biomarker of inflammation-associated dysplasia. [less ▲]

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See detailCrosstalk between VEGF and BMP9 pathway. Implications in HHT disease
Pollenus, Thomas ULg

Poster (2017, February 01)

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See detailCellular stress and β-lactamase BlaP induction in Bacillus licheniformis
Dauvin, Marjorie ULg; Joris, Bernard ULg

Poster (2017, February 01)

In presence of β-lactam antibiotic in its environment, B. licheniformis produces the β-lactamase BlaP, an enzyme hydrolyzing β-lactam antibiotic, conferring on the bacteria phenotypic resistance. To ... [more ▼]

In presence of β-lactam antibiotic in its environment, B. licheniformis produces the β-lactamase BlaP, an enzyme hydrolyzing β-lactam antibiotic, conferring on the bacteria phenotypic resistance. To induce BlaP, two conditions must be fulfilled. The first one is the acylation of the membrane receptor BlaR1 by the antibiotic. The second one is a cellular stress due to the presence of the antibiotic which acylate PBP1. The nature of this signal remains unknown. In this study we postulate that the extracytoplasmic function sigma factors (ECFs) σM and σX act together with the stringent response as a secondary and redundant layer of stress upon which the BlaP induction pathway relies. [less ▲]

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See detailEvaluating the specificity of [18F] UCB-H for the isoform SV2A, compared with isoforms SV2B and SV2C
Serrano Navacerrada, Maria Elisa ULg; Becker, Guillaume ULg; Bahri, Mohamed Ali ULg et al

Poster (2017, February 01)

Background: SV2A is the most studied isoform of the Synaptic Vesicle 2 proteins, which are involved in the synaptic vesicle trafficking, being important in normal and pathological process, like the ... [more ▼]

Background: SV2A is the most studied isoform of the Synaptic Vesicle 2 proteins, which are involved in the synaptic vesicle trafficking, being important in normal and pathological process, like the epilepsy (1, 2). [18F]UCB-H was developed like a tool to study the role of this isoform with neuroimaging techniques (3, 4). The objective of this study was to evaluate its specificity to this isoform comparing with the others, through a competition assay in rats with ex-vivo autoradiography and mPET imaging. Methods: Forty male Sprague-Dawley were used in ex-vivo autoradiography experiments (N=20) and in microPET imaging (N=20). Animals were pre-treated 30 minutes before the injection of [18F]UCB-H with a dose IP either of vehicle, Keppra (SV2A ligand), UCB068 (SV2B ligand) or UCB054 (SV2C ligand). Ex-vivo autoradiography was carried out 5 minutes after radiotracer injection while mPET images were acquiring with a dynamic scanner of 1 hour. Data were expressed in Standard Uptake Value and then, the area under the curve was calculated for the total process. Results: In ex-vivo autoradiography, ANOVA of two-ways showed statistical significant differences in brain uptake of [18F]UCB-H among the groups pretreated with Keppra or the ligand for SV2B and the control group. Regarding mPET data, statistical significant differences were found between the group injected with keppra and the rest of groups. Conclusion: Even if a considerable affinity between the ligands UCB068 and UCB054, and the receptor for the isoform SV2A exists, it is only detected during the first 5 minutes (ex-vivo technique), being certainly due to a nonspecific binding. This binding is not strong enough to show a direct competition with the radiotracer during a mPET acquisition. These results allow us to conclude that [18F]UCB-H is a suitable radiotracer for the imaging of the isoform SV2A in vivo, allowing us the clinical study about the molecular base of a disease with a high population impact, like the epilepsy. [less ▲]

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See detailImproved Blood Glucose Forecasting Models using Changes in Insulin Sensitivity in Intensive Care Patients
Uyttendaele, Vincent ULg; Dickson, Jennifer; Shaw, Geoff et al

Poster (2017, February 01)

Introduction: Hyperglycaemia, hypoglycaemia and glycaemic variability are associated with worsened outcomes and increased mortality in intensive care units. Glycaemic control (GC) using insulin therapy ... [more ▼]

Introduction: Hyperglycaemia, hypoglycaemia and glycaemic variability are associated with worsened outcomes and increased mortality in intensive care units. Glycaemic control (GC) using insulin therapy has shown improved outcomes, but have been proven difficult to repeat or achieve safely. STAR (Stochastic TARgeted) is a model-based glycaemic control protocol using a stochastic model to forecast distributions of likely future changes in insulin sensitivity (SI) based on its current value. This can be used to determine likely future blood glucose (BG) levels for a given intervention, enabling the most optimal dose selection that best overlaps a clinically defined BG target band. This study presents a novel 3D model capable to predict likely future distribution of SI using both current SI and its prior variability (%ΔSI). Methods: Metabolic data from 3 clinical ICU cohorts totalling 819 episodes and 68629 hours of treatment under STAR and SPRINT protocols are used in this study. Data triplets (%ΔSIn, SIn, SIn+1) are created and binned together in a range of %ΔSI = [-100%, 200%] and SIn = [1.0e-7, 2.1e-3] in bin sizes of %ΔSI = 10% and SIn = 0.5e-4. The 5th, 50th, and 95th percentile of SIn+1 are determined for each bin where data density is high enough (>100 triplets) and compared to the previous stochastic model. The predictive power of the two models are compared by computing median [IQR] per-patient percentage prediction of SI within the 5th-95th and 25th-75th percentile ranges of model predictions. Results: Results show the previous model is over-conservative for ~77% of the data, mainly where %ΔSI is within an absolute 25% change. The percentage change in the 90% CI width in this region is reduced by ~25-40%. Conversely, non-conservative regions are also identified, with 90% CI width increased up to ~80%. Predictive power is similar for both model (60.3% [47.8%, 71.5%] vs. 51.2 [42.9%, 59.2%] within 25th-75th and 93.6% [85.7%, 97.3%] vs. 90.7% [84.4%, 94.6%] within 5th-95th range). Conclusions: The new 3D model achieved similar predictive power as the previous model by reducing the 5th-95th percentile prediction range for 77% of the data, predominantly where SI is stable. If the conservatism of the previous model reduces risk of hypoglycaemia, it also inhibits the controller’s ability to reduce BG to the normal range by safely using more aggressive dosing. The 3D new model thus better characterises patient-specific response to insulin, and allows more optimal dosing, increasing performance and safety. [less ▲]

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See detailA multiscale model of the human cardiovascular system can account for the Frank-Starling effect on vascular filling therapy
Kosta, Sarah ULg; Pironet, Antoine; Negroni, Jorge et al

Poster (2017, February 01)

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See detailUsing unsupervised clustering method and SNP-based information to identify fine-level population structure
Chaichoompu, Kridsadakorn ULg; Yazew, Fentaw Abegaz; Tongsima, Sissades et al

Poster (2017, February 01)

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See detailZinc, manganese and iron interaction within the frd3 Arabidopsis mutant
Scheepers, Maxime ULg; Spielmann, Julien ULg; Goormaghtigh, Erik et al

Poster (2017, February 01)

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See detailMegaloolithid dinosaur eggs: scrambled parataxonomy and nesting strategies
Jentgen, Benjamin ULg; Stein, Koen; Fischer, Valentin ULg

Poster (2017, February)

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See detailEcological intensification of fish production : Fertilization strategies in Africa fish farms
Mafwila Kinkela, Patrick ULg; Kambashi Mutiaka, Bienvenu ULg; Rollin, Xavier et al

Poster (2017, February)

Ponds fertilization has been found as strategies of intensification fish production for farm in Africa were commercial feeds are not available and ingredients for formulate completed feed are cost ... [more ▼]

Ponds fertilization has been found as strategies of intensification fish production for farm in Africa were commercial feeds are not available and ingredients for formulate completed feed are cost. However, farmers are not safe to any danger because the efficiency of these strategies is not always known owing to the associated risk of eutrophication. An experience was making to assess how various fertilization practices would impact fish growth and physicochemical parameters of water in the pond. [less ▲]

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See detailCharacterization of the low-mass companion HD 142527 B
Christiaens, Valentin ULg; Casassus, Simon; Absil, Olivier ULg et al

Poster (2017, February)

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See detailNew data on the Mesozoic radiation of chelonioids
Scavezzoni, Isaure ULg; Fischer, Valentin ULg

Poster (2017, February)

"Turtles" (Testudines) form a successful group of reptiles with several terrestrial, marine and fresh-water species. Their peculiar and somewhat constrained morphology (i. e. : carapace incorporating ribs ... [more ▼]

"Turtles" (Testudines) form a successful group of reptiles with several terrestrial, marine and fresh-water species. Their peculiar and somewhat constrained morphology (i. e. : carapace incorporating ribs, curved limbs, anapsid skull exempt of temporal fenestrae) and ecology has often obscured their relationships and, hence, their evolutionary history, notably in marine turtles (chelonioids). Modern chelonioids are divided in two clades (i. e. : shoft-shelled turtles and hard-shelled turtles) supported by distinct morphological and embryological characters. Their origin is traced back up to the Cretaceous, along with a series of extinct forms, many of which being collectively known as Protostegidae. Fossil evidence show that at least five clades of marine turtles were roaming the seas at the end of the Cretaceous. In fact, chelonioids appeared during the first stages of the Early Cretaceous and quickly exploded to reach a high level of disparity at the lowermost part of the late Cretaceous. Therefore, the Mesozoic radiation of chelonioids must have happened during the "middle" Cretaceous (especially the Aptian-Albian interval). However this radiation is poorly understood as the phylogenetic relationships of marine turtles are not resolved yet. Bringing new data may help resolve these issues, and it is the exact reason why the genus Rhinochelys is being investigated. [less ▲]

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See detailThe Bright and Dark Sides of elliptical galaxies
Biernaux, Judith ULg

Poster (2017, January 29)

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See detailElaboration of a water familiarization testing battery adapted for young children
Vandermeulen, Mary ULg; Schiettecatte, Delphine; Delvaux, Anne ULg et al

Poster (2017, January 27)

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See detailChildren’s engagement in physical education could be improved by stories and imagination.
De Sousa Morgado, Liliane ULg; Jidovtseff, Boris ULg

Poster (2017, January 27)

Introduction: The development of fundamental motor skills is essential during childhood and should be a learning outcome in the physical education (PE). With the children between 3 to 6 years old it could ... [more ▼]

Introduction: The development of fundamental motor skills is essential during childhood and should be a learning outcome in the physical education (PE). With the children between 3 to 6 years old it could be sometime difficult to get their attention and motivation during PE lessons. Teachers have to use a very adapted pedagogical approach in order to get all children’s engagement. Experience: The CEReKi is a research center of the University of Liège (Belgium) that has developed adapted activities where preschools children are playing and at the same time developing perceptuals and fundamental motor skills. From our field experience one of the more efficient ways to get children attention and participation is to introduce the activities with stories and imagination. Teachers from CEReKi are using fantasy in order to invite children into a funny world where everything could become possible like the "the never-never land of Peter Pan". The way of telling the story as well as the used characters (like the wolf) must be adapted to the age of the children. Critical analysis: From our experience, using stories and imagination is effective in increasing children‘s engagement during PE as it makes activities more fun and more enjoyable. Even if we don’t have any measurement on its effect, we are convinced that such approach improve children’s motor learning. However using stories and imagination with the children is neither a natural nor an easy thing for inexperienced teachers. The use of fantasy with the children should be introduces in the vocational training. Conclusions: With more than twenty years of experience, we believe that stories and imagination are powerful factors that makes physical activities funny and enjoyable for the children. Such strategy may positively enchase young people’s attitudes towards physical education and ultimately, physical activity participation. [less ▲]

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See detailUse of complementary biophysical approaches to study the interactions of fatty acid hydroperoxides with biomimetic plant plasma membranes
Deboever, Estelle ULg; Nasir, Mehmet Nail ULg; Deleu, Magali ULg et al

Poster (2017, January 20)

In the actual context, biopesticides have emerged as a main alternative to conventional agriculture1. Hence, elicitors are metabolites naturally produced by microorganisms, pathogenic or not, and plants ... [more ▼]

In the actual context, biopesticides have emerged as a main alternative to conventional agriculture1. Hence, elicitors are metabolites naturally produced by microorganisms, pathogenic or not, and plants which are able to induce the natural resistance of plants. Also, they have proved to be excellent candidates for biological control. In this context, the lipoxygenase pathway leads to the formation of fatty acid degradation products, called oxylipins, which appear to be crucial agents in plant defence mechanisms2,3. Moreover, with their broad spectrum of action and their possible inducibility, oxylipins appear to be promising candidates for their use as elicitors4. This work focuses on two hydroperoxy-derived oxylipins, the 13(S)-hydroperoxy-octadecadienoic acid (13-HPOD) and the 13(S)-hydroperoxy-octadecatrienoic acid (13-HPOT). The study of the interaction of such compounds with representative plant plasma membrane lipids is essential to understand plant resistance mechanisms. Several in silico and experimental techniques of biophysics showed that acyl-hydroperoxides have significant adsorption capacity and a strong affinity for model membranes. They may also penetrate biological membrane but no permeabilisation effect was observed in this work. Slight conformational differences seem to have a significant impact on their ability to interact with plant plasma membranes. Based on these results, further investigation of the interactions of fatty acids hydroperoxides, even more on the 9-forms, with plant plasma membranes and eventually in the presence of phytopathogenic species, would allow a better understanding of the innate immunity and, on the longer term, could lead to the development of new elicitors with biological mechanisms potentially independent of membrane protein receptors. [less ▲]

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See detailGlobal Simulation of UV atmospheric Emissions
Gonzalez-Galindo; Lopez-Valverde; Forget et al

Poster (2017, January 19)

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See detailAnalyses des prédicteurs significatifs de l’alexithymie après une prise en charge en hôpital de jour
Nasello, Julian ULg; Quertemont, Etienne ULg; Blavier, Adelaïde ULg et al

Poster (2017, January 18)

L’alexithymie, souvent considérée comme un trait de personnalité, serait-elle sensible aux traitements psychothérapeutiques dispensés en hôpital de jour ? Quelles en seraient les variables prédictives ... [more ▼]

L’alexithymie, souvent considérée comme un trait de personnalité, serait-elle sensible aux traitements psychothérapeutiques dispensés en hôpital de jour ? Quelles en seraient les variables prédictives ? Notre recherche a porté sur un échantillon de 192 participants hospitalisés, majoritairement représenté par des patients présentant des troubles de l’humeur (64,6%). Plusieurs variables ont été prises en considération : le sexe, l’âge, la durée d’hospitalisation (M séjour = 6 semaines), la médication, les dix échelles cliniques de base du « Minnesota Multiphasic Personality Inventory-2 » (MMPI-2), l’indice de négativité au traitement du MMPI-2 (échelle TRT) et le support social perçu (PSS) mesuré par la « Multidimensional Scale of Perceived Social Support » (MSPSS). Les impacts positifs du support social perçu et les impacts négatifs de la non-adhésion au traitement se sont révélés être des prédicteurs particulièrement significatifs de l’alexithymie. [less ▲]

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See detailAlexithymie et Ouverture Émotionnelle : effets positifs de la psychothérapie de groupe en hôpital de jour
Triffaux, Jean-Marc ULg; Nasello, Julian ULg; Servais, Catherine et al

Poster (2017, January 18)

À partir d’un échantillon de 192 patients, nous avons évalué l’effet de l’hospitalisation de jour sur l’alexithymie et l’ouverture émotionnelle. Ces deux variables ont été mesurées à travers deux échelles ... [more ▼]

À partir d’un échantillon de 192 patients, nous avons évalué l’effet de l’hospitalisation de jour sur l’alexithymie et l’ouverture émotionnelle. Ces deux variables ont été mesurées à travers deux échelles : la TAS-20 [1] et la DOE-36 [2]. A l’époque de l’« evidence based medicine », ces résultats permettent d’améliorer nos interventions thérapeutiques et d’envisager, de manière clinique et scientifique, la durée de séjour optimale de nos patients. [less ▲]

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See detailA persistent meteoric layer in Mars' atmosphere
Crismani; Schneider; Plane et al

Poster (2017, January 18)

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See detailThree Types of Aurora observed by MAVEN/IUVS: Implications for Mars’ upper Atmosphere Energy Budget
Connour; Schneider; Jain et al

Poster (2017, January 17)

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See detailThe added value of plasma or urinary NGAL concentrations in clinical practice
Gregoire, Emilien ULg; Claisse, Guillaume; GUIOT, Julien ULg et al

Poster (2017, January 13)

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See detailIron, zinc and manganese interaction within the frd3 Arabidopsis mutant
Scheepers, Maxime ULg; Spielmann, Julien ULg; Goormaghtigh, Erik et al

Poster (2017, January 12)

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See detailTracking the Subtle Mutations Thriving Host Sensing by the Plant Pathogen Streptomyces scabies
Deflandre, Benoit ULg; Jourdan, Samuel ULg; Francis, Isolde Maria et al

Poster (2017, January 12)

Le modèle de la pathogénicité végétale chez les Streptomyces, S. scabies est responsable de la maladie de la galle commune. La thaxtomine est la phytotoxine qui cause cette maladie. Il y a peu, la voie de ... [more ▼]

Le modèle de la pathogénicité végétale chez les Streptomyces, S. scabies est responsable de la maladie de la galle commune. La thaxtomine est la phytotoxine qui cause cette maladie. Il y a peu, la voie de production de la toxine a été découverte : celle-ci met en oeuvre un double mécanisme de régulation génétique. Cependant, certains aspects de la perception de son hôte par le pathogène sont toujours inconnus. Dans ce poster, nous proposons plusieurs hypothèses pour expliquer comment quelques éléments subtiles peuvent être à l'origine de ce mécanisme de pathogénicité. [less ▲]

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See detailMacroevolutionary patterns in sea breams, emperors and allies (Sparoidea, Acanthomorpha)
Santini, Francesco; Olivier, Damien ULg; Frederich, Bruno ULg

Poster (2017, January 07)

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See detailStudies on sperm whales (Physeter macrocephalus) stranded on the coast of Schleswig-Holstein, Germany in 2016.
Piatkowski, Uwe; Wohlsein, Peter; Van Neer, Abbo et al

Poster (2017)

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See detailImpact of vibroseismic underwater sound on the behaviour of baleen whales
Tougaard, Jakob; Luke, Klaus; Siebert, Ursula et al

Poster (2017)

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See detailEffect of agitation rate on oxydative degradation of monoethanolamine
Benkoussas, Hana ULg; Léonard, Grégoire ULg; Kerbachi, Rabah

Poster (2017)

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See detailSelf-regulation in addiction: The dual-process model in emerging adulthood
Hoffmann, Joelle; Glowacz, Fabienne ULg; Schmits, Emilie ULg

Poster (2017)

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See detailPigs selected for increased natural resistance to PRRS are more resistant to PRRSV/PCV2b co-infection
Dunkelberger, Jenelle R; Serão, Nicolas VL; Niederwerder, Megan et al

Poster (2017)

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See detailBehavioural phenotyping of SV2A lox/lox mice: Motor and anxiety-like features
Serrano Navacerrada, Maria Elisa ULg; Bartholomé, Odile ULg; Van Den Ackerveken, Priscilla ULg et al

Poster (2017)

Background: Epilepsy is one of the most common neurological disorders (Alexopoulos, 2004). Current anti-epileptic drugs, such as Levetiracetam (Keppra®) or Brivaracetam, mainly target the trans-membrane ... [more ▼]

Background: Epilepsy is one of the most common neurological disorders (Alexopoulos, 2004). Current anti-epileptic drugs, such as Levetiracetam (Keppra®) or Brivaracetam, mainly target the trans-membrane Synaptic Vesicle Protein 2A (Hamann et al., 2008). Studies on homozygous SV2A KO mice phenotype, prove the mice to suffer severe seizures and die within 3 weeks (Crowder et al., 1999), establishing a link between this protein and the epilepsy. In 2009, the availability of heterozygous SV2A (+/-) mice as research tool enabled shedding light on the role of protein SV2A, revealing no motor differences but anxiety-like features in these mice compared with the WT (Lamberty et al., 2009), and a pro-epileptic phenotype (Crowder et al., 1999; Kaminski et al., 2008). Recently, a floxed SV2A mouse model has been produced with the Cre/loxP recombination system, this model allows invalidating the protein in CA3 hippocampal region, not followed by epileptic seizures (Menten-Dedoyart et al., 2016). Objectives: Perform a first behavioural phenotyping of SV2A lox/lox mice. Methodology: Two experiments were conducted in parallel to evaluate the effect of 3 different genotypes in the phenotype: WT (Grik4-/-, SV2A lox/lox), HZ (Grik4 +/-, SV2A lox/+) and cKO (Grik4 +/-, SV2A lox/lox) in male (n = 42) and female (n = 33) separately . Mice were housed individually along the experiment, with standard food and water ad libitum. After an acclimatization period of 2 weeks, anxiety-like features as well as exploration abilities were evaluated in an elevated plus-maze (EPM) single session of 5 minutes). 3 days later, spontaneous locomotor activity and habituation to the environment were measured during 1 hour, 3 consecutive days, in the activity chambers (ACT). Results: One-way ANOVA in EPM data presented no significant differences between groups, either in males or in females. A significant difference was found, between time spent in close arms vs open arms (p<0.01; η2p = 0.738 males; η2p = 0.805 females). Mixed between-within subjects ANOVA in ACT reflected no significant differences between groups in both sexes, regarding spontaneous locomotor activity and acclimatization to the activity chamber (p>0.05). Statistical significant differences were found between the 3 days (p<0.01; η2p = 0.716 males; η2p = 0.663 females). Conclusion: Results indicate that a decrease in the hippocampal expresion of SV2A protein does not lead to major behavioral changes. Regarding locomotor activity, the results found in heterozygous SV2A (+/-) mice are in line with (Lamberty et al., 2009), however, our mice did not present anxiety-like features, being necessary a global decrease in brain SV2A levels and not only a partial loss in a restricted region of the brain. Further analyses increasing the number of mice per group, will allow us to intensify our power value from 50-60% (females-males) up to 80%, with large effect size and a signification of p<0.05. An additional test to evaluate the spatial memory may help us better understand the effect a specific reduction in SV2A hippocampal expression has on the phenotype of mice. [less ▲]

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See detailEvolution of fast familiarity and novelty decisions in aging
Delhaye, Emma ULg; Bastin, Christine ULg; Moulin, Christopher et al

Poster (2017)

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See detailEnhancement of the internalization of lipid nanocapsules in human glioblastoma cells: Effect of surface concentration of NFL peptide
Karim, Reatul ULg; Lepeltier, Elise; Palazzo, Claudio ULg et al

Poster (2017)

Le glioblastome multiforme (GBM) est un des cancers les plus fatal, avec une médiane de survie de 14 mois après traitement. Il est donc nécessaire de développer de nouvelles thérapies plus efficaces. La ... [more ▼]

Le glioblastome multiforme (GBM) est un des cancers les plus fatal, avec une médiane de survie de 14 mois après traitement. Il est donc nécessaire de développer de nouvelles thérapies plus efficaces. La fonctionnalisation en surface de nanocapsules lipidiques (LNC) avec le peptide NFL-TBS.40-63 (NFL) a déjà montré une amélioration de leur internalisation dans des cellules de glioblastome murin. Le but de cette étude a été d’évaluer l’impact de la concentration en NFL présente en surface des LNC sur l’internalisation de ces dernières dans des cellules humaines de GBM U87MG. De plus, le mécanisme d’internalisation LNC-NFL a été étudié. Une sonde fluorescente (DiA) a été encapsulé dans : des LNC (F1), des LNC avec 0.86 % et 2.58 % (w/w) de NFL adsorbé à la surface (F2 et F3 respectivement). Des analyses par cytométrie en flux (FACS) ont révélé une internalisation cellulaire de F3 plus importante de 46.4 et 6.8 fois après 30 min, de 21.6 et 6.1 fois après 1 heure, de 31.5 et 1.6 fois après 6 heures et de 7.3 et 1.1 fois après 24 heures, comparés à F1 et F2 respectivement. L’internalisation de F3 dans les cellules U87MG s’est révélée être énergie-dépendant, avec comme mécanisme principal la macropinocytose. Les cinétiques de désorption du peptides (obtenues par dialyse de F3 dans du Tris-Buffer pH 7.4 à 37°C suivi par une HPLC analytique) ont montré que 66 % de NFL restaient à la surface des LNC après 6h de dialyse, montrant une désorption lente. De plus, les trois formulations ont montré une faible activation du complément. Du fait d’une internalisation significativement plus prononcée et rapide, F3 semble être prometteur pour améliorer l’efficacité des thérapies antiGBM. De plus, la lente désorption du NFL de la surface des LNC et la faible consommation du complément font de F3 une thérapie ciblé prometteuse contre le GBM. [less ▲]

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See detailStudy of virus-like particles of human papillomavirus in capillary electrophoresis
Bettonville, Virginie ULg; Nicol, Jérôme; Furst, Tania et al

Poster (2017)

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See detailRewiring of porcine mRNA and miRNA networks in response to selection of residual feed intake
Beiki, Hamid; Schroyen, Martine ULg; Rakshandeh, Anoosh et al

Poster (2017)

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See detailIncidence of MAGED2 on cell cycle after a camptothecin treatment
Trussart, Charlotte ULg; Pirlot, Céline; Piette, Jacques ULg et al

Poster (2017)

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See detailFeedback effect on children's global metacognitive judgments
Geurten, Marie ULg; Meulemans, Thierry ULg

Poster (2017)

In three experiments, we investigated whether the feedback effect on the accuracy of children’s metacognitive judgments results from an improvement in monitoring processes or the use of the Anchoring-and ... [more ▼]

In three experiments, we investigated whether the feedback effect on the accuracy of children’s metacognitive judgments results from an improvement in monitoring processes or the use of the Anchoring-and-Adjustment heuristic. The purpose of Experiment 1 was to investigate whether 4-, 6-, and 8-year-old children are able to use feedback to increase the accuracy of their memory judgments. To do so, children in three age groups were divided into two experimental conditions (feedback or no feedback). After studying a list of associated words, participants were instructed to predict their future memory performance, and then they were asked to recall as many items as possible. Next, half of the participants were given concrete feedback about the accuracy of their global prediction. Once the feedback was provided, all children were presented with another set of associated word pairs and the procedure was repeated. Our results revealed that children’s predictions were more accurate in the feedback than in the no feedback condition, indicating that getting feedback about the accuracy of their judgments had a positive influence on their subsequent memory predictions. In Experiment 2, we sought to determine whether young children are able to use the Anchoring-and-Adjustment heuristic to guide their global memory predictions. For this purpose, 4-, 6-, and 8-year-old children were divided into three experimental conditions depending on the anchor that was provided (high, low, or no anchor). Data indicated that children’s predictions were higher in the high than in the low anchor condition, suggesting that children in all age groups adjusted their prospective judgment depending on the random anchor they were given. Finally, the primary aim of Experiment 3 was to determine whether the feedback effect can serve as an external anchor for children’s global prospective judgments. To do so, children (aged 4, 6, and 8 years) were presented with two memory tasks that differed in terms of difficulty. Participants were randomly assigned to an anchoring (high, low, or no anchor) and a feedback (feedback or no feedback) condition to obtain a balanced experimental design. Results showed that children in the feedback condition adjusted their predictions toward the feedback, regardless of the task’s difficulty. These findings are consistent with the hypothesis that external information provided by feedback is used as an anchor for judgment. This interpretation is strengthened by the correlation found between the two scores computed to assess participants’ susceptibility to anchoring and feedback effects, which indicates that children who are more sensitive to the anchoring effect are also more sensitive to the feedback effect. [less ▲]

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See detailÉtude de la spécificité d’épreuves langagières chez des enfants présentant une dyspraxie verbale (DV) vs un trouble phonologique (TP)
Masson, Pauline ULg; Martinez Perez, Trecy ULg

Poster (2017)

Malgré une augmentation de la recherche sur la dyspraxie verbale, l’évaluation de ce trouble langagier reste problématique. La littérature propose une variété de critères pour le diagnostic de la ... [more ▼]

Malgré une augmentation de la recherche sur la dyspraxie verbale, l’évaluation de ce trouble langagier reste problématique. La littérature propose une variété de critères pour le diagnostic de la dyspraxie verbale, cependant la majorité des caractéristiques cliniques sont également partagées avec les troubles phonologiques (Davis & Velleman, 2000 ; Murray et al., 2015). L’objectif de cette recherche est de déterminer des épreuves qui permettent de différencier une dyspraxie verbale et un trouble phonologique. Nous avons exploré les marqueurs les plus couramment utilisés dans la littérature : l’imprécision des productions phonologiques et l’intelligibilité réduite (Aziz et al., 2010), l’inconstance des erreurs (Forrest, 2003 ; Tubul-Lavy, 2012), la prosodie inappropriée (Shriberg et al., 2003) et la lenteur d’articulation (Shriberg, 2013). Nous avons récolté des données auprès de deux groupes d’enfants francophones présentant une dyspraxie verbale (N=12) ou un trouble phonologique (N=12). Nos deux groupes sont appariés sur le score du QI non verbal, le niveau de compréhension orale et le niveau socio-économique. Les résultats de cette recherche mettent en évidence quatre mesures dont les valeurs de sensibilité/spécificité sont entre acceptables (>80%) et bonnes (>90%) : les pourcentages de réponses correctes et de consonnes correctes à une épreuve de dénomination d'images ; la stabilité des productions dans une épreuve de récit sur images (mots présentés à trois reprises) ; et la vitesse d’articulation pour la série diadocosinésique /pataka/. Pour ces quatre mesures, les résultats montrent que la dyspraxie verbale et le trouble phonologique se situent sur un continuum de sévérité (la dyspraxie verbale entrainant des manifestations plus sévères que le trouble phonologique). Ces résultats seront discutés lors de la session poster. [less ▲]

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See detailA new solar reference spectrum from 165 to 3088 nm
Damé, Luc; Meftah, Mustapha; Bolsée, David et al

Poster (2017)

Since April 5, 2008 and until February 15, 2017 the SOLAR/SOLSPEC spectro-radiometer on the International Space Station performed accurate measurements of Solar Spectral Irradiance (SSI) from the far ... [more ▼]

Since April 5, 2008 and until February 15, 2017 the SOLAR/SOLSPEC spectro-radiometer on the International Space Station performed accurate measurements of Solar Spectral Irradiance (SSI) from the far ultraviolet to the infrared (165 nm to 3088 nm). These measurements are of primary importance for a better understanding of solar physics and of the impact of solar variability on climate (via Earth's atmospheric photochemistry). In particular, a new reference solar spectrum is established covering most of the unusual solar cycle 24 from minimum in 2008 to maximum. Temporal variability in the UV (165 to 400 nm) is presented in several wavelengths bands. These results are possible thanks to revised engineering corrections, improved calibrations and new procedures to account for thermal and aging advanced corrections. Uncertainties on these measurements are evaluated and compare favorably with other instruments. [less ▲]

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See detailContribution of macrophages to myxomatous valve disease
Hulin, Alexia ULg; Potter, Sarah; Kim, Andrew et al

Poster (2017)

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See detail[18F]UCB-H RADIOTRACER AS A TOOL TO UNDERSTAND THE ROLE OF THE SV2A PROTEIN
Serrano Navacerrada, Maria Elisa ULg; Becker, Guillaume ULg; Bahri, Mohamed Ali ULg et al

Poster (2017)

Background: SV2A is the most studied isoform of the Synaptic Vesicle 2 proteins, which are involved in the synaptic vesicle trafficking, being important both in normal as in pathological process (1, 2 ... [more ▼]

Background: SV2A is the most studied isoform of the Synaptic Vesicle 2 proteins, which are involved in the synaptic vesicle trafficking, being important both in normal as in pathological process (1, 2). Until now, only one study in vivo has been reported, showing a reduction of SV2A levels in the epilepsy (3). [18F]UCB-H was developed like a current tool to study the role of SV2A with in vivo techniques (4, 5), and as a tool in clinical investigations. The objective of this research was to evaluate the radiotracer specificity to this isoform comparing with the others, through a competition assay in rats with ex-vivo autoradiography and mPET imaging. Methods: Forty male Sprague-Dawley were used in ex-vivo autoradiography experiments (N=20) and in microPET imaging (N=20). Animals were pre-treated 30 minutes before the injection of [18F]UCB-H with a dose IP either of vehicle, Keppra (SV2A ligand), UCB068 (SV2B ligand) or UCB054 (SV2C ligand). Ex-vivo autoradiography was carried out 5 minutes after radiotracer injection while mPET images were acquiring with a dynamic scanner of 1 hour. Standard Uptake Value (SUV) and Distribution Volume (VT) were calculated and the correlation between both parameters was determined. Results: In ex-vivo autoradiography, ANOVA of two-ways showed statistical significant differences in brain uptake of [18F]UCB-H among the groups pretreated with Keppra or the ligand for SV2B and the control group. Regarding mPET data, statistical significant differences were found between the group injected with keppra and the rest of groups. Pearson Correlation between SUV and VT was strong, with a value of 0.955. Conclusion: Even if a considerable affinity between the ligands UCB068 and UCB054, and the receptor for the isoform SV2A exists, it is only detected during the first 5 minutes (ex-vivo technique), being certainly due to a nonspecific binding. This binding is not strong enough to show a direct competition with the radiotracer during a mPET acquisition. These results allow us to conclude that [18F]UCB-H is a suitable radiotracer for the imaging of the isoform SV2A in vivo, allowing us the clinical study about the molecular base of a disease with a high population impact, like the epilepsy. 1) Van Vliet et al., 2009. Epilepsia 2) Crèvecœur et al., 2013. BMC Neurosci. 3) Finnema et al., 2016; Sci Transl Med. 4) Bretin et al., 2013.EJNMMI Res 5) Bretin et al., 2015.Mol Imaging Biol [less ▲]

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See detailIN VIVO STUDY OF THE SV2A PROTEIN IN THE KAINIC ACID EPILEPSY RAT MODEL
Serrano Navacerrada, Maria Elisa ULg; Becker, Guillaume ULg; Bahri, Mohamed Ali ULg et al

Poster (2017)

Introduction Epilepsy is one of the commonest neurological disorders [1]. Antiepileptic drugs mainly target the SV2A protein [2] but its actual role is still largely unknown. [18F]UCB-H was developed to ... [more ▼]

Introduction Epilepsy is one of the commonest neurological disorders [1]. Antiepileptic drugs mainly target the SV2A protein [2] but its actual role is still largely unknown. [18F]UCB-H was developed to study in vivo SV2A brain proteins [3, 4]. The present pilot study was undertaken to evaluate for the first time in vivo in rats SV2A expression in the Kaïnic Acid (KA) epilepsy model [5]. Although this model is well studied in mice, few reports were devoted to rats. Imaging-wise, rats are very interesting thanks to a bigger brain size (reduction of the partial volume effect). Methods Three male Sprague-Dawley were used, one injected with saline and two with multiple KA injections (3 x 5mg/kg) [6]. 75 days later, when spontaneous seizures started to appear, microPET (Focus 120 ) was performed under isoflurane anesthesia (2.5-3 % in air) for 1 hour with [18F]UCB-H (41 ± 5 MBq IV tail vein) followed by MRI (9.4T Agilent, anatomical T2). Coregistration was done with PMOD 3.6 software. Data were expressed as SUV and areas under the curve were calculated for the different regions. Results [18F]UCB-H microPET images showed an important reduction (20-30%) for SV2A after KA injections mainly localized in amygdala, hippocampus, lateral parietal association cortex and cingulate cortex. The rest of the brain was globally unchanged. MRI revealed atrophy and inflammation in amygdala and hippocampus. Conclusions These preliminary results obtained in KA treated rats showed that [18F]UCB-H was able to detect important modifications for SV2A in relevant regions for epilepsy and appears as a valuable tool to follow in vivo SV2A through longitudinal studies. KA model in rats deserves for further development and validation as a tool for the study of epilepsy. [less ▲]

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See detailIN VIVO STUDY OF THE SV2A PROTEIN IN AN EPILEPTIC RAT MODEL
Serrano Navacerrada, Maria Elisa ULg; Becker, Guillaume ULg; Bahri, Mohamed Ali ULg et al

Poster (2017)

Introduction Epilepsy is one of the commonest neurological disorders, affecting more than 60 million people worldwide [1]. New and effective antiepileptic drugs mainly target the SV2A protein [2] but its ... [more ▼]

Introduction Epilepsy is one of the commonest neurological disorders, affecting more than 60 million people worldwide [1]. New and effective antiepileptic drugs mainly target the SV2A protein [2] but its actual role is still largely unknown. [18F]UCB-H was developed as a tool to study in vivo the brain expression of this isoform [3, 4]. Due to the fact that only post-mortem studies were reported so far [5] the present pilot study was undertaken in order to evaluate for the first time in vivo in rats the SV2A expression in the validated Kaïnic Acid (KA) epilepsy model [6]. Methods Three male Sprague-Dawley were used, one injected with saline (Sham) and two with multiple KA systemic injections (5mg/kg x 3) [9]. SV2A brain levels were estimated at day 75, when spontaneous seizures started to appear. Animals were anesthetized (2.5 to 3 % isoflurane), and scanned for 1 hour with [18F]UCB-H (41 ± 5 MBq IV tail vein) in a Focus 120 microPET system and with MRI (9.4T Agilent, anatomical T2). Coregistration was done with PMOD 3.6 software. Data were expressed in SUV and areas under the curve were calculated for the different regions. Results [18F]UCB-H microPET images showed an important reduction (20-30%) for SV2A after KA injections mainly localized in amygdala, hippocampus, lateral parietal association cortex and cingulate cortex. The rest of the brain was globally unchanged. MRI revealed atrophy and inflammation in amygdala and hippocampus. Conclusions These preliminary results in KA treated rats presenting spontaneous seizures showed that [18F]UCB-H microPET was able to detect important reductions for the SV2A proteins in relevant regions for epilepsy [5]. Accordingly to this, we can infer that the KA model in rats deserves for further development and validation as a tool for the study of epilepsy. [18F]UCB-H appears as a valuable tool to follow in vivo SV2A proteins through longitudinal protocols and in turn to better understand its actual role in epilepsy. References/acknowledgements This work was funded by University of Liège, F.R.S.-FNRS, Walloon Region and UCB Pharma. Alain Plenevaux is research director from F.R.S.-FNRS. [1] Alexopoulos, Epileptology, 2004 [2] Hamann et al., Eur J Pharmacol, 2008 [3] Bretin et al., Molecular Imaging and Biology, 2015 [4] Warnock et al., J Nucl Med., 2014 [5] Wang et al., J Mol Neurosci., 2014 [6] Hellier et al., Epilepsy Res., 1998 [less ▲]

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See detailIdentifying tissue specific gene expression using RNAseq data from multiple porcine tissues
Huang, Jianzhen; Schroyen, Martine ULg; Gabler, Nick et al

Poster (2017)

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See detailNitrous oxide dynamic in sea ice
Kotovitch, Marie ULg; Fripiat, François ULg; Deman, Florian et al

Poster (2017)

Fluctuations in greenhouse gases (GHGs) concentration alter the energetic budget of the climate system. There is high confidence that natural systems related to snow, ice and frozen ground are affected ... [more ▼]

Fluctuations in greenhouse gases (GHGs) concentration alter the energetic budget of the climate system. There is high confidence that natural systems related to snow, ice and frozen ground are affected. Nitrous oxide (N2O) is one of the potent GHG naturally present in the atmosphere, but witch has seen his concentration growing since industrial era. N2O has a lifetime in the atmosphere of 114 years and a global warming potential 300 time higher than that of CO2. Yet, there are still large uncertainties and gaps in the understanding of the cycle of this compound through the ocean and particularly in sea ice. Sources and sinks of N2O are therefore still poorly quantified. The main processes (except the transport processes) involved in the N2O cycle within the aquatic environment are nitrification and denitrification. To date, only one study by Randall et al. 2012 present N2O measurements in sea ice. Randall et al. pointed out that sea ice formation and melt has the potential to generate sea-air or air-sea fluxes of N2O, respectively. Study on ammonium oxidation and anaerobic bacterial cultures shows that N2O production can potentially occur in sea ice. Denitrification can act as a sink or a source of N2O. In strictly anaerobic conditions, N2O is removed by denitrification. However, denitrification can also occur in presence of O2 at trace level concentrations (<0.2 mg L-1), and in these conditions there is a large N2O production. Recent observations of significant nitrification in Antarctic sea ice shed a new light on nitrogen cycle within sea ice. It has been suggested that nitrification supplies up to 70% of nitrate assimilated within Antarctic spring sea ice. Corollary, production of N2O, a by-product of nitrification, can potentially be significant. This was recently confirmed in Antarctic land fast ice in McMurdo Sound, where N2O release to the atmosphere was estimated to 4 µmol.m-2.yr-1. This assessment is probably an underestimate since it only accounts for dissolved N2O while a significant amount of N2O is likely to occur in the gaseous form like N2, O2 and Ar. This poster address the issue related to the production of N2O within sympagic microorganisms. What process is dominant and how much N2O is produced? The determination of the isotopic composition of N2O using cavity enhanced laser absorption spectroscopy technique (Off-axis ICOS) will allow us to determine the origin of these processes. It will be based on the relative isotope abundance values and site preference data in previous studies. [less ▲]

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See detailPlant Oxylipins: Structure-function Relationships
Genva, Manon ULg; Andersson, Mats X.; Nasir, Mehmet Nail ULg et al

Poster (2017)

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See detailReactive extrusion of pharmaceutical grade PLLA
Regibeau, Nicolas ULg; Tilkin, Rémi ULg; Grandfils, Christian ULg et al

Poster (2017)

During the 20th century, degradable aliphatic polyesters have undergone fast and dynamic developments. Nowadays, these materials can be found in several areas of human activities. Originally there have ... [more ▼]

During the 20th century, degradable aliphatic polyesters have undergone fast and dynamic developments. Nowadays, these materials can be found in several areas of human activities. Originally there have been first designed for the pharmaceutical and medical fields, in particular in surgery and for drug delivery systems. In these domains, polymers are synthesized according to a batch procedure due to the low capacity needed. This work is dedicated to the optimization of a continuous synthesis of pharmaceutical grade polyesters (e.g. poly-L-lactide, PLLA) by reactive extrusion using a twin screws extruder. This equipment presents several advantages compared to batch reactor such as: absence of solvent, high degree of mixing, easiness of scale-up, and rapid continuous synthesis. PLLA synthesis by reactive extrusion has been performed adopting a co-rotating twin-screws extruder (diameter=11 mm and L/D ratio=40). A highly active catalyst must be used to reach the target conversion due to the limited residence time. Tin octoate, approved by US Food and Drugs Administration, has been used alone as catalyst considering a catalyst / monomer molar ratio of 1/5000. A polyethylene glycol has been adopted as initiator. 1H.NMR and size exclusion chromatography (SEC) have been adopted to monitor the conversion rate of the monomer and to analyse the mean molecular weights and the corresponding polydispersity. Static mechanical tests have also carried out to assess the influence of residual monomer within the polymer. Our optimization study has highlighted that the main challenging aspects were the control of the reaction atmosphere and of the residence time. In the first case, even presence in trace water can competitively initiate the polymerization, but also promote hydrolysis. In order to reach a high monomer conversion (≥ 99 %), the residence time has to be well controlled and extended. This latter parameter is particularly affected by the screw configuration and the use of the protic initiator. In particular, the screw configuration was based on previous studies dedicated to the synthesis of polyesters by reactive extrusion [1, 2]. After synthesis, post-processing step was realized in order to reduce the monomer residue. Once optimized we have succeeded to reach in a reproducible way high molecular weight PLLA (typically in a range of 50 to 100 KDa) with a high monomer conversion (>96 %) on a time scale of some minutes. Post-polymerization has successfully decreased the residual monomer below 1%. In conclusion, this work provides a continuous and robust process to synthesize pharmaceutical grade PLLA by reactive extrusion. References : [less ▲]

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See detailNeurobiologische Korrelate von exekutiver Kontrolle im alternden Gehirn
Overhage, Sina; Eickhoff, Simon; Jockwitz, Christiane et al

Poster (2017)

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See detailRaman imaging for diagnostic application
Malherbe, Cédric ULg; Gilbert, Bernard ULg; Eppe, Gauthier ULg

Poster (2016, December 19)

Specific dynamic biochemical compositions and molecular structures characterise healthy cells and tissues. This also stands for pathologies or cellular abnormalities which are accompanied by biochemical ... [more ▼]

Specific dynamic biochemical compositions and molecular structures characterise healthy cells and tissues. This also stands for pathologies or cellular abnormalities which are accompanied by biochemical and molecular changes. Raman spectroscopy can provide unique inputs to correlate the molecular composition and its variations with the diagnosis. In addition, the presence of metal nanoparticles in the molecule vicinity induces a remarkable enhancement (up to 1000000 times) of the Raman signal of small molecules (known as SERS effect). It opens towards applications in the field of trace analysis. In preparation for clinical applications, we evaluate, by Raman mapping, the signal detected from a SERS target deposited on solid state support. [less ▲]

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See detailIntegrated microfluidic device for the synthesis of SERS substrates
Emonds-Alt, Gauthier ULg; Malherbe, Cédric ULg; Monbaliu, Jean-Christophe ULg et al

Poster (2016, December 19)

The goal of this work is to develop a quantitative analytical method for the glyphosate and its major metabolite the aminomethylphosphonic acid (AMPA) by coupling microfluidics with surface enhanced Raman ... [more ▼]

The goal of this work is to develop a quantitative analytical method for the glyphosate and its major metabolite the aminomethylphosphonic acid (AMPA) by coupling microfluidics with surface enhanced Raman spectroscopy (SERS). This work is divided into 4 axes : (a) bimetallic nanoparticles synthesis in a microreactor, (b) nanoparticles functionnalisation, (c) SERS quantification of glyphosate/AMPA and (d) miniature prototype development composed of axes a to c. The first section aims at the synthesis of bimetallic nanoparticles (Au-Ag, Au-Cu and Ag-Cu) in a microfluidic device. This microfluidic device integrates a first section for the synthesis of monometallic nanoparticles (core) and a second section for the reductive deposition of a second metal (shell). The second axe of this work deals with the functionnalisation of nanoparticles to improve the selectivity of this method for the selected analytes. Two types of functionnalisation are studied : PEGylation (a) with multi-arm PEG ending with -SH and/or (b) with linear heterobifunctionnal PEG. The third axe consists in measuring quantitatively glyphosate and AMPA in different matrices, such as water, urine and fruit juice. Finally, the forth axe deals with the development of a portable detection system to perform on-site analysis. This prototype integrates the microfluidic device for nanoparticles synthesis, their functionnalisation, an injection port followed by a mixing section for the sample and an integrated Raman spectrometer for in-line analysis. [less ▲]

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See detailPrésentation du projet Economie et pratiques des sociétés gravettiennes dans le Nord-Ouest de l’Europe (ECOPRAT)
Touzé, Olivier ULg; Salomon, Hélène ULg; Goutas, Nejma et al

Poster (2016, December 17)

Nous présentons dans cette contribution un projet collectif porté par le Service de Préhistoire de l’Université de Liège et l’équipe Ethnologie préhistorique de l'unité mixte de recherche du CNRS ... [more ▼]

Nous présentons dans cette contribution un projet collectif porté par le Service de Préhistoire de l’Université de Liège et l’équipe Ethnologie préhistorique de l'unité mixte de recherche du CNRS Archéologie et Sciences de l'Antiquité. Le projet « ECOPRAT » entend contribuer au renouvellement des connaissances relatives aux sociétés gravettiennes du Nord-Ouest européen, et prolonger ainsi la dynamique de recherche actuelle touchant ces sociétés (Bodu et al., 2013). Il s’inscrit dans une perspective pluridisciplinaire envisagée grâce à l’association d’études technologiques, tracéologiques et archéozoologiques. Quatre sites majeurs du Nord-Ouest européen ont été retenus : les gisements de plein air de Maisières-Canal (Prov. Hainaut, Belgique) et d’Ormesson – Les Bossats (Seine-et-Marne, France), et les grottes de Goyet (Prov. Namur, Belgique) et du massif d’Arcy-sur-Cure (Yonne, France). Les sites sélectionnés possédant des historiques de recherche spécifiques, la stratégie d’analyse adoptée pour chacun d’eux est développée en adéquation avec l’état des connaissances actuelles. Les recherches sont ainsi guidées par l’obtention de données inédites qui doivent permettre, à terme : 1) une lecture renouvelée et croisée des industries lithiques et osseuses, ainsi que des ensembles fauniques et des matières colorantes découverts dans ces gisements, 2) un rééquilibrage quantitatif et qualitatif de l’intégration des différentes sources documentaires disponibles, la recherche s’étant davantage concentrée depuis plus d’un siècle sur les données de l’industrie lithique. Les deux gisements de plein air réunissent les conditions indispensables au développement d’une approche interdisciplinaire permettant de croiser objets et méthodes d’étude, afin de proposer une lecture fine des comportements techniques et économiques des sociétés gravettiennes. A cet égard, cette contribution est l’occasion de présenter les premiers résultats obtenus sur le site de Maisières-Canal. Les recherches réalisées jusqu’à présent permettent de réévaluer l’importance de l’industrie sur matières dures d’origine animale, au sein de laquelle le travail de l’ivoire de mammouth se révèle particulièrement significatif. En outre, le corpus faunique traduit une exploitation récurrente du lièvre, ce type de comportement s’avérant singulier au regard de ce qui est habituellement documenté chez les sociétés du Gravettien. Parmi les différentes activités susceptibles de laisser une trace archéologique, l’usage de matières colorantes apparaît particulièrement discret dans le cadre spatio-temporel considéré. Cet usage est cependant avéré dans les grottes d’Arcy-sur-Cure (grottes du Renne et du Trilobite), lesquelles permettront ainsi d’entreprendre une étude ciblée de ce phénomène. Enfin, les grottes de Goyet offrent la possibilité de contribuer à la connaissance de la séquence gravettienne du Nord-Ouest européen. Si le long historique des fouilles menées dans ces grottes, ainsi que les mélanges manifestes affectant les collections, ne permettent pas d’envisager une étude approfondie des comportements gravettiens, des observations préliminaires permettent en revanche de s’interroger sur le potentiel de ces sites pour la reconstitution de cette séquence. A l’instar de ce qu’ont montré les travaux récemment conduits sur le Gravettien de Spy (Pesesse & Flas, 2013), il est en effet vraisemblable que les grottes de Goyet aient été occupées à plusieurs moments de la période gravettienne. BODU P., CHEHMANA L., KLARIC L., MEVEL L., SORIANO S., TEYSSANDIER N. (dir.), 2013. Le Paléolithique supérieur ancien de l’Europe du Nord-Ouest : réflexions et synthèses à partir d’un projet collectif de recherche sur le centre et le sud du Bassin parisien, Actes du colloque de Sens, 15-18 avril 2009. Paris : Société préhistorique française (Mémoires de la Société préhistorique française, 56), 516 p. PESESSE D., FLAS D., 2013. Which Gravettians at Spy? In : ROUGIER H., SEMAL P. (eds), Spy Cave. 125 years of multidisciplinary research at the Betche-aux-Roches (Jemeppe-sur-Sambre, Province of Namur, Belgium). Volume I. Bruxelles : Institut royal des Sciences naturelles de Belgique, Société royale belge d'Anthropologie et de Préhistoire, NESPOS Society (Anthropologica et Praehistorica, 123), pp. 257-268. [less ▲]

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See detailExploring a Mediterranean mesozooplankton 13 year time-series.
Fullgrabe, Lovina; Richir, Jonathan ULg; Batigny, Antoine et al

Poster (2016, December 16)

Zooplankton plays diverse crucial roles within the marine ecosystem and can also be used as bio- indicator of climate changes since it is very sensitive to environmental changes. Therefore it is essential ... [more ▼]

Zooplankton plays diverse crucial roles within the marine ecosystem and can also be used as bio- indicator of climate changes since it is very sensitive to environmental changes. Therefore it is essential to consider long-term plankton series. Given the analysis of plankton samples is time- consuming, it requires an effective and rapid analytical method. We have used in this work a supervised learning approach adapted for the semi-automatic classification of digital images of the mesozooplankton of the Bay of Calvi (Corsica, France) by using the Zoo/PhytoImage software. Together with a 11-years long zooplankton time-series, a set of nine environmental variables were monitored in order to identify controlling factors and determine whether the communities were sensitive to global environmental changes. The main components of the mesozooplankton community were characterized by both seasonal and inter-annual variability. Additionally, variation of holoplankton and meroplankton differentiated one from each other. The holoplanktonic community could be split into two subgroups according to its variation in function of the environment: cladocerans and appendicularians, and to a lesser extent, copepods on one hand, and cnidarians, chaetognathes and thaliaceans, on the other hand. Regarding inter-annual variation, one year (2007) showed particularly low production of total zooplankton which was also the case for all the different holoplanktonic taxa. Accounting for that phenomenon were identified some potentially underlying environmental factors. Finally, although water temperature increased significantly over the last years along with the frequency of marine heat wave events, no evident change in the global zooplankton composition was observed yet. [less ▲]

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See detailInsects complex associated with the tropical basil, Ocimum gratissimum L. (Lamiaceae) in southern Benin.
Yarou, Boni Barthélémy ULg; Bokonon-Ganta, H. Aimé; Assogba Komlan, Françoise et al

Poster (2016, December 16)

Tropical basil is an aromatic leafy vegetable used for its medicinal and therapeutic properties in numerous countries in West Africa (Benin, Nigeria, Togo, etc.). In Benin, it is produced on almost all ... [more ▼]

Tropical basil is an aromatic leafy vegetable used for its medicinal and therapeutic properties in numerous countries in West Africa (Benin, Nigeria, Togo, etc.). In Benin, it is produced on almost all urban and periurban garden throughout the year for fresh market. Until now there are few or nearly no publications about the arthropod community of this specie, even less in the context of Benin. Thus, to assess this community, basil plots were mowed using a sweep net in three localities (Ouidah, Togba and Sèmè) of southern Benin. Preliminary results focus on the different insect families that colonized tropical basil in southern Benin environmental conditions. These include: Aphididae (Homoptera), Cercopidae (Homoptera), Chrysomelidae (Coleoptera), Coccinelledidea (Coleoptera), Meloidae (Coleoptera), Braconidae (Hymenoptera), Ichneumonidae (Hymenoptera), Formicidae (Hymenoptera), Vespidae (Hymenoptera), Apoidae (Hymenoptera), Reduviidae (Heteroptera), Pentatomidae (Heteroptera), Pyrgomorphidae (Orthoptera), Acrididae (Orthoptera), Syrphidae (Diptera), Diopsidae (Diptera). Among these families, there are pests: Aphis gossypii G. (Homoptera: Aphididae), Zonocerus variegatus L. (Orthoptera: Pyrgomorphidae), etc.; predators: Ischiodon aegyptius W. (Diptera: Syrphidae), Cheilomenes spp. (Coleoptera: Coccinelledidea), Rhynocoris spp. (Heteroptera: Reduviidae), etc.; parasitoids and pollinators. From this study, it appeared that there is a large diversity of families and functional groups (pests, predators, parasitoids and pollinators) associated with tropical basil . Moreover, the presence of natural enemies could be an advantage for farmers in intercropping systems. This would help reduce the use of synthetic insecticides. This result, which is a first knowledge of the insect fauna associated with tropical basil under the environmental conditions of Southern Benin, will be supplemented by a spatio temporal study to assess the variability and the dynamics of this insect fauna. [less ▲]

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See detailDetermining the Substorm Onset Instability Using Ground and Space-Based Measurements
Rae, Jonathan; Watt, Clare; Murphy, Kyle et al

Poster (2016, December 16)

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