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See detailQuantitative profiling of endogenous polar metabolites from low volumes of blood samples
Kok, Miranda ULg; Fillet, Marianne ULg

Poster (2017, October 05)

The etiology of many diseases is not yet completely understood. The involved biological processes might be resolved using a metabolomics approach, because metabolomics provides unique challenging ... [more ▼]

The etiology of many diseases is not yet completely understood. The involved biological processes might be resolved using a metabolomics approach, because metabolomics provides unique challenging opportunities to correlate the metabolome with a physiological or pathophysiological status and provides a vision on the relationships between genes, gene expression, environment and lifestyle. Here, we present the development of two ultra-high performance liquid chromatography (UHPLC) methods coupled to mass spectrometry (MS) for the separation and quantitation of polar metabolites in blood samples. A reversed-phase UHPLC-MS/MS method has been developed to quantify anionic energetic metabolites, whereas hydrophilic interaction chromatography (HILIC)-MS/MS has been used to determine amino acids. Two sample pretreatment procedures have been developed for an optimal recovery of the respective metabolites from whole blood samples. One method involved the precipitation of proteins with acetonitrile and acids. In addition, volumetric absorptive microsampling has been used for the sample preparation. Small and accurate quantities of biological fluids (10 or 20 µL) can be collected with this sampling technique, which is of great interest for volume-limited samples or serial collection of samples. The developed methods have been validated and will be applied to determine differences in metabolite concentrations between plasma samples from patients and controls. This can lead to a breakthrough in the understanding of diseases and can open new therapeutic perspectives. [less ▲]

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See detailValidité et utilité d'un test d'orientation dans le secteur de la santé en Fédération Wallonie Bruxelles
Detroz, Pascal ULg; Monseur, Christian ULg; Romainville, Marc et al

Poster (2017, October 04)

La Fédération Wallonie Bruxelles de Belgique n’avait pas, jusqu’en 2016, de Filtres à l’entrée des études de Médecine. Elle avait par contre un test diagnostique, formatif, obligatoire, mais non ... [more ▼]

La Fédération Wallonie Bruxelles de Belgique n’avait pas, jusqu’en 2016, de Filtres à l’entrée des études de Médecine. Elle avait par contre un test diagnostique, formatif, obligatoire, mais non contraignant (il n'avait pas d'effet sur l'avenir des étudiants). Ce test se présentait sous la forme d’un questionnaire à choix multiple (QCM) évaluant plusieurs matières : la chimie, la physique, la biologie, les mathématiques, le français et l’anglais. Il se déroulait en même temps sur le site des cinq universités concernées par les études dans le domaine de la santé de la FWB. Les questions du test sont identiques dans ces différentes universités. Il a été organisé entre 2013 et 2016 , deux fois par année en juillet et septembre. L’enjeu était de permettre aux étudiants de mesurer leur compétence à l’entrée des études pour se rassurer (pour les plus fort d’entre eux), pour s’améliorer à travers des activités de remédiation, ou éventuellement pour renoncer (pour les pl us faible d’entre eux). La présente étude a pour objet d’évaluer l’efficacité de ce test diagnostic. Concrètement, les objectifs de l'étude décrite étaient de/d’ : 1. Analyser la qualité psychométrique du test d'orientation. 2. Établir le lien entre les données biographiques de l’étudiant et les résultats au test d'orientation. 4. Établir le lien entre les résultats au test d'orientation et l’inscription réelle en faculté de médecine.(l'effet de dissuasion du test) 3. Établir le lien entre le test d'orientation et la réussite globale et par matière à la fin de la première année. Nos conclusions générales sont les suivantes : Les tests d’orientation présentent une bonne qualité psychométrique. C’est toutefois plus vrai pour les disciplines scientifiques que pour l’anglais et le français. Le test vise bien les aptitudes spécifiques et les compétences prérequises pour entreprendre des études supérieures dans le secteur de la santé. Les candidats proviennent d’un milieu socio-économique élevé et présentent un parcours scolaire au dessus de la moyenne. Ces variables expliquent, chez les étudiants diplômés du secondaire en Belgique, plus de 30% de la variance du score de sciences au test d'orientation (score factorisé à partir des scores de maths, bio, chimie et physique) et plus de 10% du score de langue (score factorisé à partir des scores de français et d’anglais) à ce même test. Ces mêmes variables de présage expliquent aussi en partie le résultat en fin de premier bachelier (22% de variance expliquée pour les étudiants diplômés en Belgique, 34% pour les étudiants diplômés en France). Les résultats aux tests d’orientation, quant à eux, expliquent ensemble 29% de la variance aux résultats de bac1 pour les étudiants diplômés en Belgique et 17% pour ceux diplômés en France. Le test de sciences s’avère beaucoup plus prédictif que le test de langues Les test dissuade peu les étudiants les plus faibles de s’inscrire. Ces résultats seront présentés lors de la communication [less ▲]

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See detailPrevalence and characteristics of group B streptococcus colonization in HIV-infected pregnant women in Belgium
DAUBY, Nicolas; ADLER, Catherine; Y MIENDJE DEYI, Véronique et al

Poster (2017, October)

Objectives: High incidence of GBS sepsis has been reported in HIV-exposed but uninfected (HEU) infants in both developed and developing countries, particularly late-onset diseases. We aimed determining ... [more ▼]

Objectives: High incidence of GBS sepsis has been reported in HIV-exposed but uninfected (HEU) infants in both developed and developing countries, particularly late-onset diseases. We aimed determining the prevalence, the characteristics and the risk factors of GBS carriage in HIV-infected and HIV uninfected pregnant women (PW). Methods : Between 1/01/2011 and 31/12/2013, HIV-infected (n=132) and uninfected (n=123) PW had recto-vaginal swabs for GBS detection performed at 35-37 weeks of gestation and at deliver Demographic, obstetrical and medical data related to HIV-infection were prospectively collected. Serotyping of GBS strains was performed on a limited number of randomly selected samples (26 from HIV-infected and 13 from uninfected PW). Results : The overall prevalence of GBS carriage was not statistically different between HIV-infected and uninfected PW (31% vs 24,4% respectively). Age, nadir CD4 cell count, CD4 cell count at delivery and detectable viral load at delivery were not associated with GBS carriage rate in HIV-infected PW. A distinct pattern of GBS serotype was found in HIV-infected PW who were predomina colonized by serotype III (12/26) while HIV-uninfected PW were mostly colonized by serotype Ia (8/13) (p<0,05). Conclusions: As previously reported in other countries, HIV-infected PW do not have significantly higher rate of GBS colonization. However, our results suggest that HIV-infected PW are more lik be colonized with serotype III strains, that is the main serotype associated with late-onset neonatal sepsis. Ongoing research aims at characterizing the clonal features of the isolated strains [less ▲]

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See detailUpdate of the characteristics of Group B Streptococci (GBS) colonizing pregnant women in Belgium: capsular-type distribution, pili characterization, antimicrobial susceptibility profile and Multiple Locus Sequence Types.
SACHELI, Rosalie ULg; MEEX, Cécile ULg; DESCY, Julie ULg et al

Poster (2017, October)

Aim: Improving knowledge and characterization of GBS strains colonizing pregnant women in Belgium. Methods: In 2013, collection of 387 strains of GBS from 80 laboratories participating in a national ... [more ▼]

Aim: Improving knowledge and characterization of GBS strains colonizing pregnant women in Belgium. Methods: In 2013, collection of 387 strains of GBS from 80 laboratories participating in a national survey among pregnant woman. For each strain, determination of capsular-polysaccharide type agglutination and PCR, of pili-type by PCR and of antimicrobial susceptibility by disk-diffusion, broth-microdilution and detection of resistant genes by PCR. For serotype III strains, determination sequence-type by Multiple-Locus Sequence-Typing (MLST). Results: Serotype III was the most prevalent (28.5%) followed by serotypes V, Ia, II, IV and Ib (20.4%, 19.9%, 17.8%, 7%, 5.4%). Serotypes VI, VII and IX were found each once. All strains remained susceptible to penicillin (MICs: 0.03-0.125 mg/L) and other beta-lactams tested; 28.7% were resistant to erythromycin and 26.7% to clindamycin. With regards to pili, all 387 strains harboured one the PI-2 variants alone or in combination and 70.3% contained PI-1. The 110 serotype III isolates were resolved into 18 STs. The most common were ST-17 (35.5%) followed by ST-19 (30%) and ST- ST-27, ST-23 (<=5%). Conclusion: Among GBS from colonized pregnant women in Belgium: capsular-type and pili distributions, and MLST profile among type III strains were quite similar to reported data from Europ and USA during the last decade. As showed in this study, penicillin remains the first line drug of choice. On the contrary, resistance rates against macrolides/lincosamide, has reached a plateau since a decade, but it is noteworthy to notify the emergence of strains with isolated resistance to clindamycine. [less ▲]

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See detailSharing good practices in physical education to promote physical activity, wellness and health
Bonni, Jérémy ULg; Cloes, Marc ULg

Poster (2017, September 15)

The Wallonia-Brussels Federation is about to overhaul its education system, which will directly affect teacher training. Under the “Pact for Excellence in Education”, a group of experts – the Consortium ... [more ▼]

The Wallonia-Brussels Federation is about to overhaul its education system, which will directly affect teacher training. Under the “Pact for Excellence in Education”, a group of experts – the Consortium “Physical Activities, Well-Being and Health” – drawn from the 12 French-speaking institutions training PE teachers (universities and colleges) has been mandated by the Ministry of Education to design devices and tools aiming at implementing the new common core curriculum that is under construction. Good practices have been identified then described in information sheets common to the different consortiums of the PEE and listed in a table that cross-references the 6 dimensions of physical activity at school (Snyers et al., 2014) and the 20 objects of teaching-learning in health education (Turcotte et al., 2011). These good practices are meant to be shared later within a community of practice. This paper provides a description of one of these information sheets in order to illustrate the methodology applied in this project. [less ▲]

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See detailExecutive functions in normal aging: the mediating effect of processing speed and attentional system
Gilsoul, Jessica ULg; Simon, Jessica ULg; Collette, Fabienne ULg

Poster (2017, September 14)

Objective The normal aging is associated with decrease in executive functioning efficiency. However, the source of these cognitive difficulties could reside in some factors that are not executive per se ... [more ▼]

Objective The normal aging is associated with decrease in executive functioning efficiency. However, the source of these cognitive difficulties could reside in some factors that are not executive per se. Therefore, this present study is aimed at determining whether speed of processing and attentional variables would mediate the effect of age on the executive functioning. Participants and Methods Young (n = 104) and old (n = 63) participants were enrolled and carried out a large battery made of 21 executive (inhibition, shifting, working memory updating, and double task coordination), attentional (phasic alertness, selective attention, and sustained attention), and processing speed tasks. Based on Baron & Kenny’s recommendations (1986), mediation models of the age effect on the executive functioning were carried out with processing speed and attentional system taken as mediators. Results Selective attention significantly mediated the effect of age on working memory updating [􀇻R2 = 7%, p < .001]. Moreover, processing speed significantly mediated the effect of age on shifting [􀇻R2 = 7%, p < .001], working memory updating [􀇻R2 = 5%, p < .001], and double task coordination [􀇻R2 = 14%, p < .001]. Conclusions The mediating effect of age on most of the executive functions by measures of processing speed is in agreement with the literature showing a major influence of the slowdown of the processing speed on cognition (Salthouse, 1992; 2000; 2005). The age effect on inhibition did not seem to be mediated neither by the attentional variables nor the speed variables, which is in accordance with Zacks & Hasher’s hypothesis (1988). According to these authors, inhibition would be the first cognitive function to decline with age. [less ▲]

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See detailFrom Metabolomics Study of Age-Related Macular Degeneration (AMD) to the Development of New Pyruvate Dehydrogenase Kinase Inhibitors (PDK)
Arslan, Deniz ULg; Schoumacher, Matthieu ULg; Pirotte, Bernard ULg et al

Poster (2017, September 14)

Age-related macular degeneration (AMD) is a leading cause of blindness in the elderly population of industrialized countries. This blindness results from the deterioration of the macula, a small part of ... [more ▼]

Age-related macular degeneration (AMD) is a leading cause of blindness in the elderly population of industrialized countries. This blindness results from the deterioration of the macula, a small part of the retina specialized for the high-acuity vision. Exudative AMD, called “wet”, is characterized by the formation of new blood vessels growing under the retina according to a process named choroidal neovascularization (CNV). Currently, the aetiology and pathogenesis of AMD remain unclear. Nevertheless, a recent metabolomics study performed on the serum of “wet” AMD patients and on a CNV murine model, that mimics the effect of “wet” AMD, have demonstrated that lactate level is clearly involved in the severity of the pathology as well as the relationship between lactate, CNV and AMD [1]. According to this result, we suggest a new therapeutic approach of AMD based on the normalization of blood lactate level. The modulation of the lactate plasma concentration by treatment of the animals with synthetic compounds and more specifically Pyruvate Dehydrogenase Kinase (PDK) inhibitors significantly decrease the CNV. PDK and its four isoforms (PDK1-4) regulate the activity of the pyruvate dehydrogenase complex (PDH), a mitochondrial enzyme that plays a major role in the metabolic pathway of glucose, by reversible phosphorylation. Starting from these results, development of new PDK inhibitors could open the way to innovative treatment opportunities in AMD disease. Different analogues of (R)-3,3,3-trifluoro-2-hydroxy-2-methylpropanamide (fig.1) have been already synthetized and pharmacological evaluation is currently in progress. According to the results obtained, various pharmacomodulations will be investigated. [less ▲]

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See detailUsing IPCAPS to identify fine-scale population structure
Chaichoompu, Kridsadakorn ULg; Fentaw Abegaz, Yazew ULg; Tongsima, Sissades et al

Poster (2017, September 09)

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See detailUp-scalable spray-drying synthesis of Na2Ti3O7
Piffet, Caroline ULg; Vertruyen, Bénédicte ULg; Mahmoud, Abdelfattah ULg et al

Poster (2017, September 07)

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See detailOptimization of hydroxyapatite synthesis via sol-gel process for bone reconstruction application
Tilkin, Rémi ULg; Regibeau, Nicolas ULg; Grandfils, Christian ULg et al

Poster (2017, September 07)

During the past few years, tissue engineering has become one of the most promising techniques to maintain, improve, or reconstruct human tissue, even complete human organs. This solution is frequently ... [more ▼]

During the past few years, tissue engineering has become one of the most promising techniques to maintain, improve, or reconstruct human tissue, even complete human organs. This solution is frequently based on the realization of temporary porous matrices, also called "scaffolds". Scaffolds are highly porous matrices notably designed to structure the development of cells, but also to guarantee the function of the implant during the regeneration process. Several materials have been proposed for the conception of scaffold. These have to meet strict criteria regarding biocompatibility, degradability, mechanical and surface properties. As a result of their biomimetism, bioceramics, like hydroxyapatite (Ca5(PO4)3(OH)), have been widely developed during the past few years for bone reconstruction. The aim of this study is the optimization of the synthesis of hydroxyapatite by sol-gel process to be used in the conception of scaffold for bone reconstruction application. In this optic, powder obtained from two synthesis processes (wet precipitation and sol-gel process) were compared with commercial hydroxyapatite. For wet precipitation process, calcium nitrate and phosphoric acid were used as reagent. For sol-gel process, calcium acetate was used as the source of calcium and triethylphosphate as the source of phosphate. Reagents were mixed and the solution was aged. The powder was then dried and sintered. Finally, particles were washed in HCl to remove CaO and then dried. Those new materials were characterized, particularly in terms of chemical composition (XRD, FTIR), crystallinity (XRD), morphology (SEM, TEM), size (TEM, DLS) and Ca/P ratio (EDX). [less ▲]

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See detailValidation of a TEOS based sol-gel coating for the protection of carbon fibres against oxidation regarding their use in metal matrix composites
Montrieux, Henri-Michel ULg; Lecomte-Beckers, Jacqueline ULg; Halleux, Jacques et al

Poster (2017, September 07)

The use of sol-gel coating on graphite substrates has sucessfuly been done. In particular, in the field of metal matrix composites, some authors state that the use and cure of TEOS sol-gel on carbon based ... [more ▼]

The use of sol-gel coating on graphite substrates has sucessfuly been done. In particular, in the field of metal matrix composites, some authors state that the use and cure of TEOS sol-gel on carbon based fibres may improve the liquid magnesium infiltration. The described mechanism is the lowering of the liquid/solid contact angle under some specific conditions of time and temperature by the occurrence of a metal-oxide exothermal chemical reaction. Furthermore the application of silica based sol-gels on carbon fibres in order to control the medium to high temperature oxidation of fibres preforms is less investigated. The primary objective is to understand more deeply the oxidation of some uncoated fibres by the comparison of ESEM observations to TGA/ATD curves. The secondary objective is to formulate and coat a TEOS based sol-gel on T300 carbon fibres and to evaluate the new oxidation behaviour. The ternary objective is to measure in a simple way the gain of oxidation resistance of some coated fibres. [less ▲]

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See detailCatalytic reforming of biomass gasification tars with bimetallic catalysts
Wolfs, Cédric ULg; Claude, Vincent; Lambert, Stéphanie ULg

Poster (2017, September 07)

The thermochemical method called “biomass gasification” is generating emphatic interest for the production of bio-Syngas (CO+H2) since this process presents the advantage of being renewable without ... [more ▼]

The thermochemical method called “biomass gasification” is generating emphatic interest for the production of bio-Syngas (CO+H2) since this process presents the advantage of being renewable without emitting CO2. However, in practical applications, there are still some technical problems due to high concentration of tars in the outlet gas, which can condensate and clog the pipes. Previous studies have highlighted the fact that the tar elimination via catalytic reforming seem to be the more practical and economical solution. Reforming catalysts present the following properties : a tailored mesoporous texture for the support and the high dispersion of active sites like metallic nanoparticles (Ni, Pd, Fe,…) [1]. In this work, Ni based alumina catalysts and doped with a second metal (Co, Cu, Fe, Mn, Mo) are synthesized by an aqueous sol-gel process. [less ▲]

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See detailProtein-polysaccharide complexes, a tool for protein delivery in CaCO3 microparticles
Ramalapa, Bathabile ULg; Crasson, Oscar ULg; Vandevenne, Marylène ULg et al

Poster (2017, September 06)

INTRODUCTION The controlled delivery of proteins within calcium carbonate (CaCO3) particles is currently widely investigated. The success of these carriers has been driven by the ionic interactions ... [more ▼]

INTRODUCTION The controlled delivery of proteins within calcium carbonate (CaCO3) particles is currently widely investigated. The success of these carriers has been driven by the ionic interactions between proteins and particles making the encapsulation of proteins highly dependent on the pH of reaction solutions and the isoelectric point of the protein.1 This poses a great limitation on the successful loading of proteins into microparticles. In this study, we explored the use of polysaccharide-protein interactions to strongly enhance the encapsulation of proteins in CaCO3 microparticles. EXPERIMENTAL METHODS Previously, Vandevenne and colleagues2 inserted a human chitin binding domain (ChBD) that has intrinsic affinity for hyaluronic acid (HA) into β-lactamase (BlaP). This generated chimeric protein, named BlaPChBD, was shown to be fully bifunctional. In this study this hybrid protein (BlapChBD) was associated to HA and successfully loaded into CaCO3 microparticles using super critical CO2 technology aided by the templating effect of HA on CaCO3. Furthermore, thrombin cleavage sites were engineered on both sides of the inserted ChBD in the chimeric BlaP so that release of the protein from the microparticles could be easily achieved by protease cleavage. The microparticles were characterised for size, surface charge, poly-morphism and protein loading and in-vitro release assays were performed. RESULTS AND DISCUSSION The presence of ChBD inserted into the β-lactamase increased the encapsulation of the protein by 6-fold when complexed with HA (Fig. 1). In addition, we also showed that the encapsulated BlaP remains stable during this process using kinetic reaction of β-lactam hydrolysis. Our data showed that vaterite CaCO3 microparticles of sizes ranging between 4 and 7 µm were produced. We were also able to demonstrate that thrombin cleavage increased the release of the protein from the microparticles within 36 hours from <25% to 87% (Fig. 2). In conclusion, the presence of ChBD successfully improved the encapsulation yield of the protein while retaining up to 81% of its activity. CONCLUSION Protein-polysaccharide complexation demonstrates an excellent approach for the delivery of sensitive biomacromolecules which can otherwise be complicated due to electrostatic hindrances. Future prospects include using the methods we have developed for encapsulation of therapeutic proteins and using calcium carbonate as a carrier and scaffold in bone regeneration for example. [less ▲]

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See detailSurface solar radiation modelling over 1900-2014: comparison between the regional climate model MAR and reanalyses
Wyard, Coraline ULg; Doutreloup, Sébastien ULg; Belleflamme, Alexandre ULg et al

Poster (2017, September 04)

Many studies show that the surface solar radiation has underwent large variations over the second half of the 20th century as a result of variations in cloud cover and aerosol loading in the atmosphere ... [more ▼]

Many studies show that the surface solar radiation has underwent large variations over the second half of the 20th century as a result of variations in cloud cover and aerosol loading in the atmosphere. However, it is difficult to build strong conclusions before the 1950s because of the observations scarcity. The evolution of the surface solar radiation has been reconstructed over 1900-2014 using the regional model MAR (« Modèle Atmosphérique Régional ») which has recently been chosen to be part of the EURO-CORDEX project, thanks to the CORDEX.be project. Simulations were performed at a horizontal resolution of 5 km over a domain of 600 x 550 km² covering Belgium. Boundary conditions were provided by four reanalysis products: ERA-interim (1979-2014) completed by the ERA40 (1958-1978), NCEP/NCAR-v1 (1948-2014), ERA-20C (1900-2010) and 20CRV2C (1900-2010). Surface solar radiation measurements from the Global Energy Balance Archive and cloud cover observations from Belgocontrol covering 1966-2007 were used for the evaluation of the MAR model and the forcing reanalyses. Results show that MAR produces much better results than the reanalyses. The driving reanalyses can generate divergent trends while they assimilate observations and are supposed to represent the same climate. [less ▲]

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See detailSynthesis, characterization, and durability study of Pt-Co hollow nanoparticles deposited on carbon xerogel electrocatalysts for Proton Exchange Membrane Fuel Cells (PEMFC)
Zubiaur, Anthony ULg; Asset, Tristan ULg; Olu, Pierre-Yves et al

Poster (2017, September)

Proton exchange membrane fuel cell (PEMFC) catalysts are generally made of carbon black (CB)supported platinum-based nanoparticles. However, the properties of CBs, as described by RodríguezReinoso [1 ... [more ▼]

Proton exchange membrane fuel cell (PEMFC) catalysts are generally made of carbon black (CB)supported platinum-based nanoparticles. However, the properties of CBs, as described by RodríguezReinoso [1], are not optimal for electrocatalysis. A possible solution to the drawbacks of CBs is the use of synthetic nanostructured materials with a controllable and reproducible texture and with a pure, known and constant chemical composition; carbon xerogels (CX) exhibit such properties [2]. Recently, various highly dispersed CX-supported Pt nanoparticles catalysts (Pt/CX) have been synthesized via several methods, such as the strong electrostatic adsorption (SEA) [3] or the charge-enhanced dry impregnation (CEDI) [4]. However, the decrease of the Pt mass contained in the PEMFC electrodes, in particular at the cathode where the oxygen reduction reaction (ORR) is processed, remains a major challenge. Improving the ORR mass activity is currently best achieved by alloying Pt with 3d-transition metal atoms such as cobalt (Co). These alloys perform better than the ORR because the substitution of some Pt atoms by 3d-metal atoms with smaller radius leads to a modified Pt electronic structure [5]. The synthesis and durability of Pt-Co hollow particles/CX (Fig. 1) is currently being studied in our groups. The results indicate that the specific and mass activity of the bimetallic hollow particles dispersed on CX is ca. 10 times higher than that of pure Pt/CB. The first durability results show good stability of the hollow particles structure. Performances and accelerated stress tests (ASTs) in PEMFCs were finally performed. [less ▲]

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See detailAn active bacterial community linked to high chl-a concentrations in Antarctic winter-pack ice and evidence for the development of an anaerobic sea-ice bacterial community
Eronen-Rasimus; Luhtanen, A.-M.; Rintala, J.-M. et al

Poster (2017, September)

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See detailDietary inulin supplementation promotes weight loss in obese individuals
Hiel, Sophie; Rodriguez, Julie; Gianfrancesco, Marco ULg et al

Poster (2017, September)

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See detailNew filamentous mutant of Yarrowia lipolytica and its use in biofilm bioreactors
Vandermies, Marie ULg; Kar, Tambi ULg; Denies, Olivia ULg et al

Poster (2017, September)

The non-conventional yeast Yarrowia lipolytica is widely investigated for its unusual metabolic properties. Among them is the ability of Y. lipolytica to adopt an ovoid or hyphal morphology according to ... [more ▼]

The non-conventional yeast Yarrowia lipolytica is widely investigated for its unusual metabolic properties. Among them is the ability of Y. lipolytica to adopt an ovoid or hyphal morphology according to environmental conditions. The mechanism of dimorphic transition involves numerous genes, which have been poorly documented to date. Here, we report on the isolation of a filamentous mutant from an insertion mutagenesis library, the subsequent identification of the mutated gene, and the use of this filamentous mutant in biofilm bioreactors. [less ▲]

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See detailUseful tools for genome editing in the non-conventional yeast Yarrowia lipolytica
Vandermies, Marie ULg; Denies, Olivia ULg; Nicaud, Jean-Marc et al

Poster (2017, September)

The non-conventional yeast Yarrowia lipolytica is increasingly used for the production of recombinant proteins or biomolecules with biotechnological or pharmaceutical applications. The development of such ... [more ▼]

The non-conventional yeast Yarrowia lipolytica is increasingly used for the production of recombinant proteins or biomolecules with biotechnological or pharmaceutical applications. The development of such a cell factory requires steps of genome editing that rely on selectable markers. The recently identified EYK1, encoding erythrulose kinase, can serve as an efficient catabolic selectable marker for genome editing in Y. lipolytica. Besides, the cloning-free strategy developed here simplifies the construction of disruption cassettes for genome editing in Y. lipolytica. [less ▲]

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See detailPromoting "health literacy friendly" healthcare institutions
Henrard, Gilles ULg

Poster (2017, September)

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See detailPreparation and characterization of Silicon-carbon composite powders using recycled Silicon from solar cells as anode material in Li-ion batteries
Eshraghi, Nicolas ULg

Poster (2017, September)

Currently, silicon (Si) coming from the recycling of solar cells is a non-valued fraction. The principal aim of this work is the development of silicon recovered during the dismantling of solar panels as ... [more ▼]

Currently, silicon (Si) coming from the recycling of solar cells is a non-valued fraction. The principal aim of this work is the development of silicon recovered during the dismantling of solar panels as electrode material for Li-ion batteries. The main technological challenge associated with the use of silicon in this type of application is to control the volume expansion during charge/discharge cycles. This drawback could be avoided through the formation of Silicon/carbon composites in which the size of the silicon particles and their dispersion must be controlled. In this research, we develop a carbon matrix consisting of graphene or carbon nanotubes (CNT) that allow the incorporation of silicon particles coated with a carbon layer (Si@C/C). The process is divided in two main steps : I) the grinding of leached Si wafer pieces in order to extract pure Si powder and then a mixed aqueous suspension of this recycled Si and an organic carbon source (Acetic acid, Ascorbic acid or Lactose) is spray-dried followed by heat treatment to generate the coating of silicon particles with carbon (Si@C). Then, II) aqueous suspension of Si@C and graphene/CNT is spray dried and calcined to obtain the final composite structure (Si@C/C). The morphology of composite materials is analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Electrochemical performance of Si@C/C composites are characterized by galvanostatic charge-discharge cycling and electrochemical impedance spectroscopy (EIS). [less ▲]

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See detailFlowering roots: Insensitive Root Growth 1 contributes to photoperiod-induced root responses in Arabidopsis.
Orman-Ligeza, Beata ULg; Detry, Nathalie ULg; Tocquin, Pierre ULg et al

Poster (2017, September)

The capacity to perceive and respond to seasonal changes of day length is essential for flowering plants. Under favourable photoperiod, a mobile stimulus synthesized in leaves moves to the shoot apex and ... [more ▼]

The capacity to perceive and respond to seasonal changes of day length is essential for flowering plants. Under favourable photoperiod, a mobile stimulus synthesized in leaves moves to the shoot apex and triggers the expression of genes required for the transition to flower initiation. Although transition from vegetative to reproductive state also encompasses a transcriptional response in roots, the internal signalling pathways and how root system architecture adjusts to this changing status remain elusive. Here we show in Arabidopsis that root growth rate increases upon a transfer to flowering-inductive long days while remaining constant under short days. To elucidate genetic components of this response, we performed a meta-analysis of available root-growth and flowering-related arrays and selected genes with overlapping transcriptional profiles for further analyses. Loss of function in a member of the basic leucine zipper transcription factor gene family, hereafter named Insensitive Root Growth-1 (IRG1), was found to suppress photoperiod-response of root growth with no defect in flowering time. We show that sucrose, but neither glucose nor mannitol in the growth medium under long days, is needed to trigger this response. In addition, extending the photoperiod with non-photosynthetic far red light had no effect on root growth of irg-1 mutant, alike wild type Col-0. The expression level of IRG1 in the roots remains low during the daytime and peaks late at night, suggesting that this gene is regulated by the clock’s evening loop. Taken together, our results suggest that IRG1 may be involved in sucrose-mediated stimulation of root growth during the night phase in Arabidopsis. The functional characterisation of IRG1 is currently underway. [less ▲]

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See detailTowards understanding the function of JOINTLESS gene in tomato inflorescence
Huerga Fernandez, Samuel ULg; Gómez Roldán, Maria Victoria; Orman-Ligeza, Beata ULg et al

Poster (2017, September)

The lack of fruit abscission is a trait of great agronomical value. In tomato, the jointless phenotype, referring to the lack of abscission zone (AZ) in the flower pedicel, has been obtained by two ... [more ▼]

The lack of fruit abscission is a trait of great agronomical value. In tomato, the jointless phenotype, referring to the lack of abscission zone (AZ) in the flower pedicel, has been obtained by two independent mutations, named jointless (j) and jointless-2 (j-2). The corresponding genes encode MADS-box transcription factors, as shown in 2000 for J (Mao et al. 2000) and very recently for J-2, known as SlMBP21 (Gomez-Roldan et al., 2017). Similar to the quartet model of MADS-box protein complexes regulating floral organ formation, J and J-2 interact with MADS-box partners, among which MACROCRALYX (MC), to regulate AZ formation (Liu et al. 2014). In addition to - or in connection with - AZ formation, J acts during the building of the inflorescence to regulate meristem fate. Indeed j mutants produce leafy inflorescences characterized by faster flower maturation and resumption of vegetative meristems (Périlleux et al. 2014). For these traits, j is epistatic to j-2. The involvement of J in the regulation of meristem fate is consistent with the roles of its closest homologs in Arabidopsis, AGAMOUS LIKE 24 (AGL24) and SHORT VEGETATIVE PHASE (SVP). Our goal is to identify J targets in order to unravel its multiple functions in the tomato inflorescence. [less ▲]

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See detailThe Economic Development Pole (EDP) approach in Niger: the case of the Niger-IFAD Program
Andres, Ludovic ULg; Populin, Martha; Bodé, Sambo et al

Poster (2017, August 29)

Since 2012, the Niger-IFAD Programme uses a new non-administrative geographical intervention unit, the Economic Development Pole (EDP). The EDP is described as a space concentrating economic activities ... [more ▼]

Since 2012, the Niger-IFAD Programme uses a new non-administrative geographical intervention unit, the Economic Development Pole (EDP). The EDP is described as a space concentrating economic activities linked to the production and commercialization of the main agro-pastoral products of the neighbouring production basins. This poster aims to describe and analyze the concept of EDP, to show its first results when put into practice and to analyze its risks. [less ▲]

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See detailMultiple Uses of a 3D Point Cloud: the Castle of Franchimont (Province of Liège, Belgium)
Luczfalvy Jancsó, Andrea ULg; Jonlet, Benoît ULg; Hallot, Pierre ULg et al

Poster (2017, August 29)

This poster presents the identified obstacles, needs and selected solution for the study of the medieval castle of Franchimont, located in the province of Liège (Belgium). After taking into account the ... [more ▼]

This poster presents the identified obstacles, needs and selected solution for the study of the medieval castle of Franchimont, located in the province of Liège (Belgium). After taking into account the requirements from all the disciplines at work as well as the problems that would have to be tackled, the creation of a 3D point cloud was decided. This solution would be able to deal with the characteristics and needs of a research involving building archaeology and related fields. The decision was made in order to manage all of the available data and to provide a common working tool for every involved cultural heritage actor. [less ▲]

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See detailCompositional gap at La Picada (CSVZ, Chile) results from critical cristallinity and compaction
Vander Auwera, Jacqueline ULg; Namur, Olivier ULg; Coumont, Valentin et al

Poster (2017, August 16)

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See detailA novel approach towards manipulation of vortex matter in a superconductor with micromagnetic structures
Shaw, Gorky ULg

Poster (2017, August 10)

Hard permanent magnetic materials offer a number of advantages over softer magnetic materials as sources of vortex pinning in a superconductor, like greater stability and larger magnetic field amplitudes ... [more ▼]

Hard permanent magnetic materials offer a number of advantages over softer magnetic materials as sources of vortex pinning in a superconductor, like greater stability and larger magnetic field amplitudes. Permanent micromagnet structures prepared using thermomagnetic patterning (TMP) present an interesting and so far unexplored option for controlled artificial pinning. We have investigated the vortex matter in superconductor/TMP micromagnet heterostructures (Nb-NdFeB) using quantitative Magneto-Optical Imaging (MOI). Comprehensive protocols have been developed for calibrating and converting Faraday rotation data acquired by MOI to magnetic field maps. These protocols reveal the comparatively weaker magnetic response of the superconductor from the background of larger fields associated with the magnetic layer in its vicinity. Further, TMP micromagnet structures have been imprinted in a Permalloy (Py) layer to obtain flexible magnetic landscapes for flux guidance in a Nb layer below it. Both smooth flux penetration and vortex avalanches in Nb are observed to be strongly influenced by the micromagnetic patterns. Our study offers new insights into the peculiarities of the vortex state in these superconductor-micromagnet heterostructures. [less ▲]

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See detailTailoring the superconducting properties of niobium nanoconstrictions via electro-annealing
Lombardo, Joseph ULg; Baumans, Xavier ULg; Jelic, Zeljko ULg et al

Poster (2017, August 10)

In this work we report the possibility to create weak links in nanostructured Nb thin films using electro-annealing. By using electron-assisted atom diffusion in Nb nanconstrictions, we were able to ... [more ▼]

In this work we report the possibility to create weak links in nanostructured Nb thin films using electro-annealing. By using electron-assisted atom diffusion in Nb nanconstrictions, we were able to locally change the material properties (superconducting critical temperature and normal resistance). When the critical temperature of the nanoconstriction is sufficiently decreased, the field dependence of the critical current exhibits a Fraunhofer-like pattern, confirming the formation of the weak link. Scanning electron microscopy images clearly reveals the structural change underwent by the constriction resulting from the effect of the high current density. Numerical simulations within the Ginzburg-Landau formalism are also presented. These findings represent the first evidence of weak link formation by electro-annealing and provide an easy method for the fabrication of Josephson junctions with tunable resistance and critical temperature in Nb thin films. [less ▲]

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See detailAssessing quality of life using structural equation modeling
Dardenne, Nadia ULg; Pétré, Benoît ULg; Husson, Eddy ULg et al

Poster (2017, August)

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See detailPrevalence of voice disorders among teachers at the beginning of their career
Schiller, Isabel ULg

Poster (2017, August)

Due to the high vocal demands associated with their profession, teachers face an increased risk of developing voice disorders. Research suggests that up to 50 % of experienced teachers are affected. Even ... [more ▼]

Due to the high vocal demands associated with their profession, teachers face an increased risk of developing voice disorders. Research suggests that up to 50 % of experienced teachers are affected. Even student teachers, whose vocal load is still relatively low, report voice problems with a frequency of 20 % (Simberg, Laine, Sala, & Rönnemaa, 2000). Little is known about the prevalence of voice disorders among teachers at the very beginning of their career. In Germany, teachers must complete a two-year teaching practice as part of their professional training after they graduate from university, consisting of attending specialized courses and giving lessons. The aim of this symptom-based study was to determine the prevalence of voice problems among this population. A self-administered questionnaire was answered by 73 German teachers in teaching practice. The prevalence of a voice problem was defined based on the presence of two symptoms that persisted for a minimum of two weeks. Results revealed that 37 % of teachers had voice problems during their teaching practice. Among the most frequent symptoms were hoarseness, an urge to clear one’s throat and problems speaking at a loud voice. Considering that the participants had not even begun teaching full-time, the prevalence of reported voice problems is worrisome. It could be associated with their lacking experience in how to use their voice effectively. The findings highlight the necessity of early intervention programs focusing on vocal hygiene and effective voice use in classroom situations. [less ▲]

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See detailLe vocabulaire des archives des cités grecques : l’apport de l’épigraphie. Le cas des termes ἀποδέκτης et ἀποδοχεύς
Dolne, Laëtitia ULg

Poster (2017, August)

Ce poster est issu d’un projet de thèse récemment débuté à l’Université de Liège et consacré à l’étude du vocabulaire technique des différents aspects de l’archivage dans les cités grecques antiques. Un ... [more ▼]

Ce poster est issu d’un projet de thèse récemment débuté à l’Université de Liège et consacré à l’étude du vocabulaire technique des différents aspects de l’archivage dans les cités grecques antiques. Un des objectifs du projet est de réaliser un lexique systématique, exhaustif et raisonné, fondé sur une analyse approfondie et contextualisée des sources littéraires, épigraphiques et papyrologiques grecques et latines de c. IIIe s. av. J.-C. à c. IIIe s. apr. J.-C. Une fois achevé, le lexique facilitera pour tous l’accès aux sources de l’activité archivistique ancienne et, de ce fait, sa compréhension et son étude dans un cadre plus global. En effet, la lecture de ces sources est entravée par la diversité et la technicité des termes qui y abondent et peuvent avoir, selon le contexte, mais aussi le lieu et l’époque, des acceptions différentes, et donc désigner des réalités distinctes. Le poster illustre cette problématique, ainsi que la méthodologie employée dans le projet, par l’exemple des termes ἀποδέκτης et ἀποδοχεύς. Alimenté principalement par la documentation épigraphique, le cas de figure choisi montre également l’important apport de cette discipline pour la réalisation d’un tel lexique. [less ▲]

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See detailCharacterising Industrial Sites' Flexibility with Reservoir Models
Cuvelier, Thibaut ULg

Poster (2017, August)

Electro-intensive industrial sites are very dependent on electricity prices to remain competitive. Nevertheless, they can often tune their processes in order to decrease their electricity consumption ... [more ▼]

Electro-intensive industrial sites are very dependent on electricity prices to remain competitive. Nevertheless, they can often tune their processes in order to decrease their electricity consumption during the most critical periods, for example by using decision support systems based on mathematical modelling of their processes. Our goal is to estimate the flexibility potential of a complete site, not to tune each process very precisely. To this end, we propose a generic paradigm to help conceiving such models: reservoirs are the basic building block, which allows for great expressiveness while being close to the physics. More specifically, we do not need very precise models for our purposes, but ones that can be efficiently included in optimisation models. Our first results show that the obtained reservoir models can give sufficiently good approximations for metallurgical and other processes. [less ▲]

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See detailDesign and Synthesis of [18F]BPAM121, a PET-Probe Targeting AMPA-subtype Glutamatergic Receptors.
Manos-Turvey, Alexandra ULg; Lemaire, Christian ULg; Becker, Guillaume ULg et al

Poster (2017, August)

AMPA receptors (AMPARs), one of three sub-groups of ionotropic glutamate receptors present in the central nervous system, are recognised for their involvement in long-term potentiation (LTP), and learning ... [more ▼]

AMPA receptors (AMPARs), one of three sub-groups of ionotropic glutamate receptors present in the central nervous system, are recognised for their involvement in long-term potentiation (LTP), and learning and memory processes. [1] They represent a valid cognitive enhancer target, particularly in the fight against Alzheimer’s disease (AD). [2,3] Benzothiadiazine 1,1-dioxides, such as BPAM121, have emerged as important allosteric modulators of AMPARs, working solely in the presence of the endogenous transmitter. [4] Synthesis of BPAM121 labelled with fluorine-18 was proposed, to investigate the utility of this molecule as a PET probe in vivo, and evaluate its potential as an AD diagnostic tool (Figure 1). [Figure 1. a) Structure of BPAM121, b) Established radiochemical synthesis of [18F]BPAM121.] This work documents the successful optimization of synthesis, purification and formulation of [18F]BPAM121 using an automated FASTlab (GE Healthcare) synthesizer. In particular, the influence of higher-level [18F]fluoride ion starting concentrations on final product formulation requirements is discussed. Initial results revealed [18F]BPAM121 successfully passes the blood brain barrier, and further biological studies are currently underway. References [1] S. F. Traynelis et al. Pharmacol. Rev. 2010, 62, 405-496. 
 [2] J. Keifer, Z. Zheng, Eur. J. Neurosci. 2010, 32, 269-277. 
 [3] L. Gao et al. J. Neurochem. 2016, 136, 620-636. 
 [4] P. Francotte et al. J. Med. Chem. 2010, 53, 1700-1711. 
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See detailThermoelectric properties of heavily-doped Fe2YZ full-Heusler compounds
Lemal, Sébastien ULg; Ricci, Fabio ULg; Verstraete, Matthieu ULg et al

Poster (2017, July 31)

Fe2YZ full-Heusler compounds were recently predicted to exhibit very large thermoelectric power factors [Phys. Rev. Lett. 114, 136601 (2015)]. Combining first-principles density functional theory ... [more ▼]

Fe2YZ full-Heusler compounds were recently predicted to exhibit very large thermoelectric power factors [Phys. Rev. Lett. 114, 136601 (2015)]. Combining first-principles density functional theory calculations within a hybrid functional approach and Boltzmann semi-classical transport theory, we investigate the limits of the rigid band doping approximation, and the properties of heavily n-type doped full-Heusler Fe2YZ1-xAx compounds. Using a supercell approach and including explicit dopant impurities, we recover in some cases giant thermoelectric power factors, as previously predicted within the rigid band approximation. In others the effect on the electronic structure is very different from rigid shifts. Interestingly, we find that some systems present a magnetic instability consistent with the Stoner model, and evolve towards a ferromagnetic half-metallic ground state, with a strongly modified power factor. Our results show the promise of the heavily-doped phases of the studied Fe2YZ1-xAx compounds for Seebeck and spin-dependent Seebeck applications. [less ▲]

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See detailThe Prediction-Focused Approach: An opportunity for hydrogeophysical data integration and interpretation in the critical zone
Hermans, Thomas ULg; Nguyen, Frédéric ULg; Klepikova, Maria et al

Poster (2017, July 27)

Two important challenges remain in hydrogeophysics: the inversion of geophysical data and their integration in quantitative subsurface models. Classical regularized inversion approaches suffer from ... [more ▼]

Two important challenges remain in hydrogeophysics: the inversion of geophysical data and their integration in quantitative subsurface models. Classical regularized inversion approaches suffer from spatially varying resolution and yield geologically unrealistic solutions, making their utilization for model calibration less consistent. Advanced techniques such as coupled inversion allow for a direct integration of geophysical data; but, they are difficult to apply in complex cases and remain computationally demanding to estimate uncertainty. We investigated a prediction-focused approach (PFA) to directly estimate subsurface physical properties relevant in the critical zone from geophysical data, circumventing the need for classic inversions. In PFA, we seek a direct relationship between the data and the subsurface variables we want to predict (the forecast). This relationship is obtained through a prior set of subsurface models for which both data and forecast are computed. A direct relationship can often be derived through dimension reduction techniques (Figure 1). For hydrogeophysical inversion, the considered forecast variable is the subsurface variable, such as the salinity or saturation for example. An ensemble of possible solutions is generated, allowing uncertainty quantification. For data integration, the forecast variable is the prediction we want to make with our subsurface models, such as the concentration of contaminant in a drinking water production well. Geophysical and hydrological data are combined to derive a direct relationship between data and forecast. We illustrate the methodology to predict the energy recovered in an ATES system considering the uncertainty related to spatial heterogeneity. With a global sensitivity analysis, we identify sensitive parameters for heat storage prediction and validate the use of a short term heat tracing experiment to generate informative data. We illustrate how PFA can be used to successfully derive the distribution of temperature in the aquifer from ERT during the heat tracing experiment. Then, we successfully integrate the geophysical data to predict heat storage in the aquifer using PFA. The result is a full quantification of the posterior distribution of the prediction conditioned to observed data in a relatively limited time budget. [less ▲]

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See detailBuilding flow and transport models with electrical resistivity tomography data
Gottschalk, Ian; Hermans, Thomas ULg; Knight, Rosemary et al

Poster (2017, July 26)

Aquifer recharge and recovery (ARR) is the process of enhancing natural groundwater resources and recovering water for later use by constructing engineered conveyances. Insufficient understanding of ... [more ▼]

Aquifer recharge and recovery (ARR) is the process of enhancing natural groundwater resources and recovering water for later use by constructing engineered conveyances. Insufficient understanding of lithological heterogeneity at ARR sites often hinders attempts to predict where and how quickly infiltrating water will flow in the subsurface, which can adversely affect the quality and quantity of available water in the ARR site. In this study, we explored the use of electrical resistivity tomography (ERT) to assist in characterizing lithological heterogeneity at an ARR site, so as to incorporate it into a flow and contaminant transport model. In this case, we had non-collocated well core log data and ERT data from a full-scale ARR basin. We compared three independent methods for producing conditional lithology-resistivity probability distributions: 1) a search template to relate the nearest logged well lithologies with ERT resistivity panels, given search criteria; 2) a maximum likelihood estimation (MLE) to match bimodal normal distributions to the histogram of each ERT line; and 3) variogram-based lithology indicator simulations constrained to well data. Each approach leverages Bayes’ Rule to estimate lithology probability given electrical resistivity. The simplest approach (method 1) yields an erroneous conditional probability function where sand dominates the conditional probability at nearly all resistivities, due in part to the strong presence of sand in the wells nearest the ERT lines. The approaches using MLE and lithology simulations (methods 2 and 3) produce similar, more realistic lithofacies probability functions. The range of resistivities where clay and sand overlap differs between methods 2 and 3: ranging between 100 and 200 ohm-m for method 2, and between 30 and 50 ohm-m for the method 3. These differences affect the posterior lithology distributions in multiple point geostatistical (MPS) simulations, and in turn, predictions of flow from models which integrate these results. To test the models, we can compare measured breakthrough times of recharged water at the site to groundwater flow simulation results using the lithofacies models created by each method. The methods described here can inform the integration of non-collocated geophysical data into a variety of applications. [less ▲]

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See detailThe effect of initial water distribution and spatial resolution on the interpretation of ERT monitoring of water infiltration
Dumont, Gaël ULg; Pilawski, Tamara ULg; Robert, Tanguy et al

Poster (2017, July 25)

A better understanding of the water balance of a landfill is crucial for its management, as the waste water content is the main factor influencing the biodegradation process of organic waste. In order to ... [more ▼]

A better understanding of the water balance of a landfill is crucial for its management, as the waste water content is the main factor influencing the biodegradation process of organic waste. In order to investigate the ability of long electrical resistivity tomography (ERT) profiles to detect zones of high infiltration in a landfill cover layer, low resolution time lapse data were acquired during a rainfall event. Working at low resolution allows to cover large field areas but with the drawback of limiting quantitative interpretation. In this contribution, we use synthetic modeling to quantify the effect of the following issues commonly encountered when dealing with field scale ERT data: (i) the effect of low resolution on electrical resistivity changes interpretation, (ii) the effect of the original heterogeneous resistivity distribution on the observed relative resistivity changes, (iii) the need for temperature and pore fluid conductivity data in order to compute water content and absolute changes of water content, and (iv) the interpretation error commonly made while neglecting the dilution effect during fresh water infiltration. Firstly, due to the lack of spatial resolution, the regularized inversion process yields a smoothed distribution of resistivity changes that fail to detect small infiltration zones and yields an overestimation of the infiltration depth and an underestimation of the infiltrated volume in large infiltration areas. Secondly, the analysis of relative changes, as commonly used in literature, is not adequate when the background water content is highly heterogeneous. In such a case, relative changes reflect both the initial water content distribution and the observed changes. Thirdly, the computation of absolute water content changes better reflects the infiltration pattern, but requires spatially distributed temperature and pore fluid conductivity input data. Lastly, the dilution effect, if not considered, leads to an underestimation of the infiltrated volume. Taking into account these elements, we extracted the maximum amount of information from our field data without over-interpreting the results. This allowed the detection of larger infiltration areas possibly responsible for a large part of the annual water infiltration and landfill gas loss. [less ▲]

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See detailDual-specificity-phosphatase 3 (DUSP3) deletion promotes liver inflammation and high fat diet-induced hepatocellular carcinoma
Jacques, Sophie ULg; Arjomand, Arash ULg; Vandereyken, Maud ULg et al

Poster (2017, July 24)

Overweight and obesity are considered as risk factors for hepatocellular carcinoma (HCC) development. The mechanisms by which obesity promotes liver inflammation are however poorly understood. We recently ... [more ▼]

Overweight and obesity are considered as risk factors for hepatocellular carcinoma (HCC) development. The mechanisms by which obesity promotes liver inflammation are however poorly understood. We recently generated a full DUSP3 knockout (KO) mouse. The obtained mice were born normal with no spontaneous phenotype. However, while aging, DUSP3-KO mice became obese and developed hepatosteatosis. The phenotype was exacerbated under high fat diet (HFD). Furthermore, when treated with diethylnitrosamine (DEN) procarcinogen, DUSP3-KO mice developed HCC faster than WT littermates. The combination of DEN with HFD accelerated the onset of HCC development in these mice compared to WT mice. This was associated with increased systemic levels of several metabolites and with hyperphosphorylation of the insulin-like growth factor receptor I. [less ▲]

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See detailFunctional and structural characterisation of the Arabidopsis thaliana HMA4 protein
Lekeux, Gilles ULg; Laurent, Clémentine; Xiao, Zhiguang et al

Poster (2017, July 24)

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Peer Reviewed
See detailItem purification versus adjustments for multiple comparisons in DIF detection
Drabinova, Adela; Martinkova, Patricia; Magis, David ULg

Poster (2017, July 18)

Detailed reference viewed: 25 (1 ULg)
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See detailA Novel Accelerometer-Based Method for Stride Length Estimation
Boutaayamou, Mohamed ULg; Schwartz, Cédric ULg; Denoël, Vincent ULg et al

Poster (2017, July 14)

We demonstrate the feasibility of accurately and precisely estimating the left/right average stride length from measured heel/toe accelerations in the gait of healthy, old adults. Our approach relies on ... [more ▼]

We demonstrate the feasibility of accurately and precisely estimating the left/right average stride length from measured heel/toe accelerations in the gait of healthy, old adults. Our approach relies on (1) a novel method that uses only accelerometer data without the need of additional data from, e.g., gyroscopes and/or magnetometers, and on (2) the validation of the results using reference 3D optoelectronic system data. [less ▲]

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See detailNon-pathological aging of the executive functions: influence of the Val108/158Met nucleotide polymorphism of the COMT gene
Gilsoul, Jessica ULg; Manard, Marine ULg; Collette, Fabienne ULg

Poster (2017, July 13)

Objectives. The aim of the study is to investigate the influence of the COMT Val108/158Met nucleotide polymorphism, associated with dopaminergic regulation, on executive functions in normal aging. Indeed ... [more ▼]

Objectives. The aim of the study is to investigate the influence of the COMT Val108/158Met nucleotide polymorphism, associated with dopaminergic regulation, on executive functions in normal aging. Indeed, according to the Dual-State Theory, Val/Val polymorphism of the COMT gene would favor better flexibility abilities, whereas Met/Met carriers would favor better stability abilities. These genotypic effects should be magnified in older people, as a decrease in cognitive resources increases the influence of individual genetic differences on cognitive performance. Method. We assessed the executive processes of inhibition, shifting, and updating – thanks to many different tasks in groups of young (n = 55) and aged participants (n = 45) carrying one of the three polymorphism of the COMT gene (Val/Val, Val/Met, Met/Met). T-tests between our two groups (Young versus Aged) but also a 6 (Group: Young-Met/Met, Young-Val/Met, Young- Val/Val, Old-Met/Met, Old-Val/Met, and Old-Val/Val) X 3 (Executive functioning: Inhibition, Shifting, and Updating) repeated measure ANOVA with Executive functioning as within-subject factor (p < .05) were carried out. Results. Young and old participants significantly differed on the three executive functions. The comparison of genotypic groups showed no significant differences in young or older participants respectively. Interestingly, the Old-Val/Val group showed a lower performance than the young one on inhibition tasks. Conclusion. As expected, we found an age effect on all the executive functions. The significant difference between the Young-Val/Val and the Old-Val/Val groups on inhibition suggests an age-related decrease in abilities requiring a stability component in individuals possessing a less favoring genotype for this component. [less ▲]

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See detailDetermining fine population structure using iterative pruning
Chaichoompu, Kridsadakorn ULg; Yazew, Fentaw Abegaz; Tongsima, Sissades et al

Poster (2017, July 10)

SNP-based information is used in several existing clustering methods to detect shared genetic ancestry or to identify population substructure (Price et al. 2006, Raj et al. 2016). Here, we present an ... [more ▼]

SNP-based information is used in several existing clustering methods to detect shared genetic ancestry or to identify population substructure (Price et al. 2006, Raj et al. 2016). Here, we present an unsupervised clustering algorithm called the iterative pruning method to capture population structure (IPCAPS). Our method supports ordinal data which can be applied directly to SNP data to identify fine-level population structure and it is built on the iterative pruning Principal Component Analysis (ipPCA) algorithm (Intarapanich et al. 2009). The IPCAPS involves an iterative process using multiple splits based on multivariate Gaussian mixture modeling of principal components and Clustering EM estimation as in Lebret et al. (2015). In each iteration, rough clusters and outliers are also identified using our own method called RubikClust. The fixation index (FST) is known to measure a distance between populations and FST = 0.001 may be said to be genetically distinct among the European populations (Tian et al. 2008, Huckins et al. 2014). To observe fine-level population structure using FST, we examined simulated scenarios of one population, 500-8,000 individuals, 5,000-10,000 independent SNPs in HWE (Balding and Nichols 1995), with 100 replicates for each scenario. The simulated SNPs were encoded as additive coding and there was no missing genotype generated. We introduced negative control by subjecting individuals to be separated into two groups using kmeans. We observed that FST values of divided groups were lower than 0.0008, which can be defined as the minimum FST to detect fine-level population structure. To evaluate the performance of our method, we tested different simulated data sets of 2-3 populations, 250 individuals per population, 10,000 independent SNPs in HWE, and FST=[0.0008,0.005], with 100 replicates for each data set. For real-life data sets, we applied the IPCAPS to Thai (Wangkumhang et al. 2013) and HapMap populations. Our method showed that a population classification accuracy was superior to the ipPCA in simulated scenarios of extremely subtle structure (FST=[0.0009,0.005]). In case of the Thai population, results to detect fine-level structure were obtained as well as in case of the HapMap populations. We are convinced that the IPCAPS has a potential to detect fine-level structure and it will be important in molecular reclassification studies of patients once underlying population structure has been removed. [less ▲]

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See detailSTUDY OF ACTIVATED SLUDGE DEWATERING : USING BIOBASED COAGULANTS
Fraikin, Laurent ULg; Clermont, Quentin; Salmon, Thierry ULg et al

Poster (2017, July 06)

This paper focuses on the dewatering efficiency of activated sludge from waste water treatment plant using biobased coagulants in addition with classical flocculant and compares the results with those ... [more ▼]

This paper focuses on the dewatering efficiency of activated sludge from waste water treatment plant using biobased coagulants in addition with classical flocculant and compares the results with those obtained with a sole classical coagulant. For this work, a standard compression-expression cell is used and an experimental design is develop to highlight the effect of the biobased coagulants. [less ▲]

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See detailComparative Proteomics Analysis Provides New Candidates for Zinc Homeostasis Regulation in Arabidopsis
Amini, Sahand ULg; Arsova, Borjana ULg; Scheepers, Maxime ULg et al

Poster (2017, July 03)

Zinc (Zn) is an essential micronutrient for plants and around two billion people are depending on grains and legumes as their main Zn source. On the other hand, this transition metal is toxic for plants ... [more ▼]

Zinc (Zn) is an essential micronutrient for plants and around two billion people are depending on grains and legumes as their main Zn source. On the other hand, this transition metal is toxic for plants at high concentrations in soils. This calls for a better unravelling of Zn homeostasis regulation mechanisms, including sensing and signaling in plants. In order to fulfill this aim, we are testing for novel proteins involved in Zn homeostasis in the model plant Arabidopsis thaliana. First, quantitative proteomics was performed on root and shoot samples obtained upon Zn starvation and re-supply in different spatio-temporal conditions. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) analysis was also performed for those treatments to measure the Zn concentration in tissues. It showed very rapid Zn uptake in root upon re-supply. Moreover, quantitative expression studies of known players of Zn homeostasis confirmed our large-scale proteomic results, although for a few genes lack of correlation between transcript and protein regulation was observed. Using clustering, statistical and gene ontology analyses, we selected candidate genes for further studies. Among more than 5000 detected proteins in roots by shotgun proteomics, 75 genes were selected for targeted analyses. In general, our results show that comparative proteomics study can be useful to reveal new players in the Zn regulatory network in plants, which can lead to new Zn biofortification and phytoremediation strategies. [less ▲]

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See detailSimultaneous Determination of Free Amino Acid Content in Different Teas using Supercritical Fluid Chromatography Coupled with Single Quadrupole Mass Spectrometry
Huang, Yang ULg; Fillet, Marianne ULg; Crommen, Jacques ULg et al

Poster (2017, July 02)

Tea (Camellia sinensis L.) is a complex mixture containing a wide range of biological activities and has been used as widely consumed beverages and natural medicine for over thousand years [1-2]. In this ... [more ▼]

Tea (Camellia sinensis L.) is a complex mixture containing a wide range of biological activities and has been used as widely consumed beverages and natural medicine for over thousand years [1-2]. In this study, a novel method for high-performance liquid chromatography with mass spectrometry (SFC-MS) has been developed to simultaneously determine the contents of 11 free amino acids in different types of teas (pu-erh tea, green tea, black tea and oolong tea). The separation conditions for the selected amino acids were carefully optimized such as the column type, temperature and backpressure, the type of additive. The best compromise for tested analytes in terms of chromatographic performance was obtained when water (5%) and trifluoroacetate acid (0.4%) were added to the supercritical carbon dioxide/methanol mobile phase. Finally, the developed SFC-MS method was successfully applied to the analysis of the 11 amino acids present in the teas and fully validated as well. The results indicated a good linearity (r ≥0.995), precision (RSD≤ 2.99%), stability (RSD≤ 2.88%) and accuracy (91.95%~107.99%). The limits of detection ranged from 1.42 to 14.69 ng/mL, respectively, while the limits of quantification were between 4.53 and 47.0 ng/mL. The content of the amino acids in six different tea samples were also determined and presented some difference basing on the fermentation processes. The proposed SFC-MS method showed a great potential in further investigations to differentiate tea varieties [less ▲]

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See detailAntarctic sea ice trophic status
Van der Linden, Fanny ULg; Moreau, Sébastien; Champenois, Willy ULg et al

Poster (2017, July)

The sea ice ecosystem is characterized by steep gradients in temperature, salinity, light and nutrient availability. Despite these challenging environmental conditions, sea ice provides a dynamic habitat ... [more ▼]

The sea ice ecosystem is characterized by steep gradients in temperature, salinity, light and nutrient availability. Despite these challenging environmental conditions, sea ice provides a dynamic habitat for diverse communities of microorganisms. These communities include a wide variety of organisms from different taxonomic groups such as algae, bacteria, heterotrophic protists, fungi as well as viruses [Horner et al., 1992; Deming, 2010; Thomas and Dieckmann, 2010; Poulin et al., 2011]. In the frame of the YROSIAE project (Year-Round survey of Ocean-Sea-Ice-Atmosphere Exchanges), carried out at Cape Evans in McMurdo Sound (Antarctica) from Nov. 2011 to Dec. 2012, ice cores, seawater, and brine material were collected at regular time intervals. Physical properties (salinity, temperature, texture) and biogeochemical parameters (pCO2, dissolved inorganic carbon, total alkalinity, chlorophyll-a, macro-nutrients) were analysed. We will here particularly consider changes inused dissolved inorganic carbon (DIC) and chlorophyll-a (chl-a) , used as a proxiesy of net community production and autotrophic biomass, respectively. A high spatial and temporal variability in ice algal biomass and DIC evolution were observed. From spring, very high chl-a concentrations (>2400μg.L^(-1)) were observed at the bottom of the ice, a common feature of land fast ice in the McMurdo Sound. This suggests high primary production. However Strikingly, , at the same time, nutrients at the bottom of the ice increased significantly suggesting high heterotrophyremineralisation. In the middle of the ice column, evolution of DIC is was marked by a succession of autotrophic and heterotrophic phases. The overall increase of DIC suggests that the ice interior was rather heterotroph. Such sea ice system should expel CO2. Yet, strong under-saturation in CO2 and DIC depletion appeared at the ice surface, suggesting that sea ice was taking up CO2 from the atmosphere. On the whole, land fast sea ice in McMurdo Sound appears as a puzzling ecosystem. It is able to support elevated growth of autotrophic organisms at the bottom, but still appears to be heterotrophicin parallel to high remineralization, while the top of the ice appears to be rather heterotrophic but stilland able to pump CO2 from the atmosphere. [less ▲]

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See detailCANINE GANGRENOUS MASTITIS : A CASE REPORT
Egyptien, Sophie ULg; Lefebvre, Michaël ULg; Guieu, Liz-Valéry ULg et al

Poster (2017, July)

This report describes the treatments and discusses the cost effectiveness of a Negative Pressure Wound Therapy (NPWT) device on a gangrenous mastitis case. Mastitis is an inflammation of the mammary gland ... [more ▼]

This report describes the treatments and discusses the cost effectiveness of a Negative Pressure Wound Therapy (NPWT) device on a gangrenous mastitis case. Mastitis is an inflammation of the mammary gland found mainly in lactating females. Coliforms (Escherichia coli), Staphylococcus spp (Staphylococcus aureus) and, to a lesser extent, Streptococcus spp are the most commonly isolated organisms in bitches. The bitch can be presented because of local signs of inflammation, puppies failing to thrive or even severe septic shock. While more common in ruminants, gangrenous mastitis is rare in the bitch. It is mostly due to Staphylococcus aureus, a gram positive and catalase positive bacteria producing alpha hemolysin. This toxin binds to ADAM10, a transmembrane protein, forming pores in the cell membrane, causing an acute inflammation via intracellular calcium flow, leading to severe oedema, necrosis and gangrene. Loss of skin integrity also comes from the cleavage of E-cadherin by ADAM10 after its toxin-mediated activation. A 8.7kg, 3-year-old neutered female Sheltie farm dog was referred to the Veterinary Clinic of the University of Liège for suspicion of septic peritonitis after an ovariohysterectomy on 4 dead puppies 36 hours earlier. They died during long lasting dystocia. Amoxicillin-acid clavulanic and enrofloxacin antibiotherapy had been initiated during surgery. The dog was in decompensated septic shock. The surgical wound was not reactive and no sign of peritonitis was seen by abdominal ultrasonography. The right inguinal and the two most caudal left mammary glands were swollen, crackling with a patchy blue discoloration. An acute fulminant mastitis with gangrenous involvement and sepsis was diagnosed. Fluids and continuous rate infusion of norepinephrine and dobutamine were administered to control severe hypotension. Metronidazole was added since Clostridium spp could not be excluded. Debridement was started as soon as the arterial pressure was stabilised and the wound was disinfected with hydrogen peroxyde for the 3 first days. While hydrogen peroxyde is indicated for catalase negative infections, the already started antibiotherapy prevented bacterial identification and sensitivity determination. Alginate-honey patches replaced wet to dry bandages after 4 days. After 7 days of progressive debridement, the wound was 15cm long, 13cm wide and 1.2cm deep. A NPWT device was placed under anaesthesia after extensive debridement. It was kept in place for one week with one renewal after 2 days under slight sedation. The wound was then surgically closed. Cutaneous sutures were removed 10 days later as cicatrization was satisfactory. NPWT is indicated in open wound management, for infection control and for stimulating granulation tissue production prior to reconstruction. It increases contraction in deep, three dimensional wounds. Closure rate is significantly shorter with NPWT than with standard wet to dry bandages. Cost of NPWT is comparable to standard bandages but more comfortable for the patient. Standards bandages require daily changes, sometimes for several weeks and under repeated anaesthesias, which may be debilitating for the patient and expensive for the owner. Conversely, NPWT is changed only once and allows earlier surgical closure of the wound. The main complication is vacuum loss, which is surgeon’s experience dependant. [less ▲]

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See detailStable isotopes reveal effects of environmental changes on ecological niches of Iphimediidae amphipods
Michel, Loïc ULg; d'Udekem d'Acoz, Cédric; Frederich, Bruno ULg et al

Poster (2017, July)

When faced with environmental changes, organisms are expected to have some intrinsic ability to adapt through ecological plasticity. However, this process is still poorly understood in many Antarctic ... [more ▼]

When faced with environmental changes, organisms are expected to have some intrinsic ability to adapt through ecological plasticity. However, this process is still poorly understood in many Antarctic invertebrates. Here, we focused on Iphimediidae amphipods, as this widely distributed family shows important ecological diversity. In total, 248 amphipods (19 species) from two widely different zones (the West Antarctic Peninsula, or WAP, and Adélie Land, AL) were studied to elucidate how environment can influence ecological niche parameters. Ecological niches were explored using stable isotope ratios of carbon and nitrogen and the SIBER approach (Jackson et al., 2011). The isotopic niche of the whole amphipod assemblage was wider in WAP than in AL. This was true for both total (proxy of the whole range of resources exploited by animals) and the core (proxy of the most commonly used resources) isotopic niches. The ratio between total and core isotopic niches was smaller in WAP than in AL (4.13 vs. 5.74), suggesting that in WAP, animals commonly use a greater relative percentage of the resources to which they have access. Niche modelling at the specific level revealed that this trend was not found in all taxa. For example, niches of Gnathiphimedia sexdentata and Iphimediella microdentata were bigger in WAP than in AL, following the general pattern. On the other hand, niches of Echiniphimedia echinata and E. hodgsoni had the same width in both areas. Moreover, relative niche overlap between these two species was much higher in WAP (42%) than in AL (20%). Our results indicate that the widely different environmental conditions encountered by the animals in these two zones clearly influence their ecology. Overall, Iphimediidae amphipods tend to exploit more resources in WAP, i.e. in the zone where impacts of global change (temperature increase, sea ice cover decrease) are the strongest. Niche overlap between some closely related (i.e. congeneric) species was also more important in WAP. Ultimately, environmental changes in this region might reinforce these trends, which might lead to competition and perturb amphipod community structure. This research was funded by the Belgian Federal Science Policy Office (BELSPO) in the framework of the vERSO and RECTO projects. [less ▲]

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See detailClinical outcome after tracheal resection and anastomosis for correction of a tracheal stenosis in a sport pony
Salciccia, Alexandra ULg; Roose, Charlotte; Joostens, Zoé ULg et al

Poster (2017, July)

Introduction: Tracheal stenosis, which refers to a narrowing of the tracheal lumen, is infrequent in horses. The literature is scarce about outcome after treatment of this pathology. Objectives: To report ... [more ▼]

Introduction: Tracheal stenosis, which refers to a narrowing of the tracheal lumen, is infrequent in horses. The literature is scarce about outcome after treatment of this pathology. Objectives: To report our experience using tracheal resection and anastomosis to treat a severe trauma-induced tracheal stenosis (< 1 cm diameter of lumen) involving 2 tracheal rings causing a loud respiratory noise at rest in a 14 y.o. event pony. Methods: The pony was trained to wear a martingale preoperatively. Before the surgery, a distal tracheotomy was performed for placement of the tracheal tube for maintenance of gaseous anaesthesia. Through a 35 cm ventral midline cervical incision, the trachea was exposed and separated from adjacent tissues. Stay sutures were placed in tracheal cartilage adjacent to the segment to be removed. The 2 tracheal rings involved in the stricture were subsequently removed. On both remaining segments of the trachea, the mucosa was turned back over the open end and sutured to the adventitia. The head was then flexed and tracheal ends were apposed using 5 stainless steel wires placed equidistantly around the trachea without mucosal penetration. The anastomosis was completed by a simple continuous suture of resorbable material on the adventitia. A closed suction drain was applied in the soft tissue before routine closure of the subcutaneous and cutaneous layers. The martingale was applied before the recovery from anaesthesia, which was uneventful. The tracheotomy tube and the suction drain were left in place for 48h. The martingale was removed after 3 weeks. The pony was discharged 1 month after surgery. Control endoscopies were performed during hospitalisation and at 7, 10, 17, 21 and 30 weeks and 1 year after surgery. Results: A moderate cicatrix recurred. The excessive tissue was injected with triamcinolone and then with 4% formaldehyde during the first endoscopies and remained stable thereafter. Some stainless steel cerclages broke and displaced slightly. This caused the formation of a self-resolving seroma caudally to the trachea. A moderate respiratory noise was still audible at low-intensity work, which was resumed 4 months postoperatively. However, work was stopped before achieving the preoperative level because the pony developed a lameness. Conclusions: Although a moderate tracheal cicatrix recurred after surgery, tracheal resection and anastomosis clearly improved the quality of life of this pony. [less ▲]

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See detailThe question of the methane increase through the retrieval of its isotopologues from FTIR ground-based observations
Bader, Whitney ULg; Strong, Kimberley; Walker, Kaley

Poster (2017, July)

Methane (CH4) is the second most important greenhouse gas emitted by human activities in the Earth’s atmosphere. Although it is roughly 200 times less abundant than carbon dioxide, it is a 28 times more ... [more ▼]

Methane (CH4) is the second most important greenhouse gas emitted by human activities in the Earth’s atmosphere. Although it is roughly 200 times less abundant than carbon dioxide, it is a 28 times more potent greenhouse gas. Approximately one fifth of the changes in the Earth’s balance energy caused by human-linked greenhouse gases since the beginning of industrialization (~1750) is due to methane. Methane is emitted by both natural sources and human activities. Indeed, methane can be emitted to the atmosphere through coal mining, oil and gas exploitation, rice cultures, domestic ruminant animals, biomass burning, waste management, wetlands, termites, methane hydrates and ocean. Since the beginning of the industrialization, atmospheric methane concentrations have increased by 260% to reach 1824 pbb in 2013. From the 1980s until the beginning of the 1990s, atmospheric methane was significantly on the rise, then stabilized during 1999-2006 to rise again afterwards. To this day, the source or sink responsible of this latter increase remains unexplained. Through each emission process, heavy molecules of methane (with one additional neutron either on a carbon or on one hydrogen atom) are emitted along methane (12CH4). The main heavy molecules of methane, called isotopologues (13CH4 and CH3D), are respectively ~110 and ~60 000 times less abundant than methane. Despite their small abundances, they give crucial information on the concentration of methane in the atmosphere and its evolution. Indeed, both isotopologues are emitted with specific emission ratio depending on the emission sources. Determining isotopic ratio of atmospheric methane is therefore a unique tracer of its budget. While the non-monotonous trend of methane is subject of an extensive number of studies, to our knowledge, no study of the isotopic ratio of methane derived from ground-based solar observations has been published to date. Measurements of heavy methane from Fourier Transform InfraRed spectra recorded with state of the art spectrometers installed at Eureka [Arctic, Canada] and Toronto [Ontario, Canada] will help fill this gap. Indeed, the produced time series will ease data interpretation and contribute to a global view of the question of isotopologues. [less ▲]

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See detailBeta Cell Regeneration in Zebrafish : Investigating the Ductal Contribution
Bergemann, David ULg; Massoz, Laura; Bourdouxhe, Jordane ULg et al

Poster (2017, July)

Diabetes is characterized by the loss of insulin producing beta cells. Although different therapeutic strategies do exist, they lack precise and dynamic control of glycemia as carried out by endogenous ... [more ▼]

Diabetes is characterized by the loss of insulin producing beta cells. Although different therapeutic strategies do exist, they lack precise and dynamic control of glycemia as carried out by endogenous beta cells. One promising alternative is to replenish the pancreas with bona fide functional beta cells by triggering regeneration mechanisms. Previous studies have shown beta cell neogenesis originating from different pancreatic cell types (alpha, delta, acinar and ductal cells), depending on the used model. The ductal origin is supported by the fact that the embryonic duct epithelium gives rise to the endocrine lineage, and that in healthy and diabetic human adults, insulin positive cells could be found next to or in pancreatic ducts. Despite these observations, mammals show very limited regenerative capabilities, making it difficult to investigate those mechanisms. In contrast, zebrafish are extensively used for regeneration studies. The ability of adult zebrafish to regenerate its beta cells and restore normoglycemia after massive beta cell ablation has already been shown. We, and other groups, have previously shown that adult pancreatic duct cells act as progenitors, giving rise to beta cells in physiological and induced diabetic condition in vivo. To get insight into this process, we conducted comparative RNA-seq experiments on pancreatic duct cells from adult zebrafish. By this means, we identified regulated gene expression that can be linked to specific processes/pathways such as cell cycling and Notch. In order to confirm the involvement of identified candidate genes/pathways, we are setting up a screening method using chemical activators and inhibitors in old larvae, by looking at their ability to modify proliferation/differentiation of duct cells after beta cell ablation. In addition, we are also investigating the effect of mutations, generated by the CRISPR/Cas9 system within candidate genes, on the regeneration capabilities. Together, these strategies should provide new clues about regenerative processes triggered in duct cells that might be applied to overcome the poor regenerative capabilities of mammals. [less ▲]

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See detailImpact of endophytic entomopathogenic fungus on plant attractivity in aphid-virus-plant interactions
Fingu Mabola, Junior Corneille ULg; Bosquée, Emilie ULg; Boullis, Antoine ULg et al

Poster (2017, July)

Endophytic entomopathogenic fungi (EEPF) are biological control agents able to live in their host plants in a symbiotic interaction and secrete secondary metabolites in the host plant tissues interacting ... [more ▼]

Endophytic entomopathogenic fungi (EEPF) are biological control agents able to live in their host plants in a symbiotic interaction and secrete secondary metabolites in the host plant tissues interacting with pests and phytopathogenic agents like plants virus. This is the case of Barley yellow dwarf virus (BYDV) transmitted by the Bird cherry oat aphid (Rhopalosiphum padi Linnaeus) and the Grain aphid (Sitobion avenae Fabricius). This virus is one of the most economically important phytoviruses affecting major world cereal crops such as wheat, rice and corn, causing significant yield losses. In this study, we investigated the influence of EEPF presence in the plant tissues on the vector’s orientation preference by considering the insect virus-infection status. We performed a choice test in Petri dishes and collection of volatile compounds emitted by plants. The impact of these interactions between plant-fungi-virus is finally discussed. [less ▲]

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See detailWhere does the methane entrapped in Antarctic sea ice come from?
Jacques, C.; Sapart, Célia Julia ULg; Carnat, G. et al

Poster (2017, July)

Methane (CH4) atmospheric concentrations have increased by a factor of 2.5 since the beginning of the Industrial Era, mainly because of anthropogenic activities. However, between 1999 and 2006, CH4 growth ... [more ▼]

Methane (CH4) atmospheric concentrations have increased by a factor of 2.5 since the beginning of the Industrial Era, mainly because of anthropogenic activities. However, between 1999 and 2006, CH4 growth rate declined to a near-zero level, suggesting that an equilibrium had been reached. But, from 2007 on, atmospheric concentrations underwent a renewed growth, implying major ongoing changes in the CH4 global budget (Nisbet et al., 2016). These changes challenge our understanding on the contribution of existing sources, and in particular natural sources. Sea ice can strongly affect emissions of CH4 from the ocean, but the precise mechanisms are not well understood. Sea ice has long been considered as an inert and impermeable barrier, but recent studies have highlighted the existence of gas fluxes at the atmosphere-sea ice and sea ice-seawater interfaces (Kort et al., 2012; He et al., 2013; Zhou et al., 2014; Sapart et al., 2016). However, these fluxes are to date poorly understood and quantified. To improve future climate projections, we aim to investigate the control exerted by sea ice on the CH4 atmospheric budget. To unravel the impacts of the Antarctic sea ice physical environment on biogeochemical cycles, the AWECS (Antarctic Winter Ecosystem Climate Study) expedition was conducted between the 8th of June and the 12th of August 2013 in the Weddell Sea. Such an expedition provides a rare opportunity to obtain insights on the behaviour of sea ice during winter. Ice cores specifically dedicated to the investigation of gas dynamics were collected at ten different stations. In order to determine CH4 formation and removal pathways in sea ice, we used concentration and stable isotope analysis, which can help to distinguish different processes. Here, we present and discuss our first results of the isotopic composition of CH4 (δ13C and δ D) on sea ice cores from the Weddell Sea and the Ross Ice Shelf. This new dataset will help to determine the origin of the CH4 entrapped in Antarctic sea ice and its potential impact on the current and future atmospheric CH4 budget. [less ▲]

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See detailN2O production and cycling within Antarctic sea ice
Kotovitch, Marie ULg; Tison, J.-L.; Fripiat, François ULg et al

Poster (2017, July)

Nitrous oxide (N2O) is a potent greenhouse gas that has a lifetime of 114 years in the atmosphere and a global warming potential 300 time higher than that of CO2. However there are still large ... [more ▼]

Nitrous oxide (N2O) is a potent greenhouse gas that has a lifetime of 114 years in the atmosphere and a global warming potential 300 time higher than that of CO2. However there are still large uncertainties and gaps in the understanding of the N2O cycle in polar oceans and particularly associated to sea ice. Sources and sinks of N2O are therefore poorly quantified. To date, only one study by Randall et al. 2012 present N2O measurements in sea ice. They pointed out that sea ice formation and melt has the potential to generate sea-air or air-sea fluxes of N2O, respectively. The main processes (except the transport processes) involved in the N2O cycle within the aquatic environment are nitrification and denitrification. 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. Our recent studies in Antarctic land fast ice in McMurdo Sound, confirmed this suggestion, where N2O release to the atmosphere was estimated to reach 4µmol.m-2.yr-1. But this assessment is probably an underestimation 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. We will then address the new tools to measure the bulk concentration of N2O (dissolved and gaseous) in sea ice, and the production of N2O by sympagic microorganisms - what process is dominant and how much N2O is produced - based on the first time series of N2O measurement in sea ice. 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. [less ▲]

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See detailLanguage abilities in preterm-born children : Specific difficulties in phonological skills
Desmottes, Lise ULg; Maillart, Christelle ULg; VIELLEVOYE, Renaud ULg et al

Poster (2017, July)

Children who were born prematurely (before 37 weeks’ gestation) are at greater risk for a range of impairments in cognitive, motor, social-emotional, and academic functioning (e.g., Bos et al., 2013 ... [more ▼]

Children who were born prematurely (before 37 weeks’ gestation) are at greater risk for a range of impairments in cognitive, motor, social-emotional, and academic functioning (e.g., Bos et al., 2013). Other developmental disorders, such as language delays and deficits, are also more common in preterm children (Van Noort et al., 2012). Because language function is essential in all kinds of social and academic life (Young et al., 2002), it is crucial to better identify and characterize language impairment in preterm-born children. Despite the large amount of research conducted on language abilities in preterm children, little is known about their phonological development (Barre et al., 2011). In the present study, we investigated differences in several phonological tasks between French-speaking premature children and in term-born control children. 30 children born at <35 weeks’ gestation (4 to 5 years old) and with low-birth weight (1215 g on mean) were recruited. These preterm children were matched to 30 children born at term on gender, chronological age and socio-economic level. All participants were administered five language tasks (phonemic discrimination, phonological judgment, pictures naming, pseudo-words repetition and phonological awareness) in order to precisely assess their phonological skills. Results indicated that preterm children presented poorer performance than control term-born children when they had to discriminate between different phonemes (phonemic discrimination abilities), to detect phonemic modifications (phonological judgment) and to recognize and identify syllabic segments (phonological awareness). Differences between both groups have also been observed in the quality of phonological representations (pictures naming task). However, both groups of children performed equally well in the pseudo-words repetition task. These findings revealed that preterm children score significantly lower compared with term-born children on several phonological tests, a language subdomain which is particularly important in the initial stages of language development and for reading. [less ▲]

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See detailLight Induced Super-Hydrophilicity in Niobium and Tantalum Oxides Thin Films
Henry, Théo ULg; Bonsague, Fabio; Dubreuil, Olivier ULg et al

Poster (2017, July)

Since its discovery at the end of the nineties by Wang et al.,[1] the interest for light-induced superhydrophilicity is ever growing. The application fields for materials displaying such a property are ... [more ▼]

Since its discovery at the end of the nineties by Wang et al.,[1] the interest for light-induced superhydrophilicity is ever growing. The application fields for materials displaying such a property are wide and numerous:[2] self-cleaning surfaces, anti-fogging, anti-bacterial, water and air purification, microfluidics…Nowadays, a research emphasis is on relatively low energy bandgap semiconductors, targeting a higher efficiency under solar irradiation or more precisely in the near UV and low-end of the visible spectral range. Here, however, we report UV-induced superhydrophilicity in metal oxides thin films showing a relatively high transparency in the UV. Reactive ion beam sputtering (IBS) was used to deposit niobium, tantalum and titanium oxides thin films with thickness ranging from 10 nm to 120 nm on fused silica substrates at room temperature. Contact angle measurements were performed for progressively increasing UV doses and also as function of elapsed time after the termination of the exposure in order to investigate the UV-induced hydrophilicity and recovery behavior of tantalum and niobium oxide thin films in comparison to that of titanium oxide deposited in analogous conditions. [less ▲]

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See detailLanguage and analogical reasoning in children with Specific Language Impairment: The effect of articulatory suppression
Krzemien, Magali ULg; Thibaut, Jean-Pierre; Stoffels, Valentine ULg et al

Poster (2017, July)

Analogical reasoning shares a mutual influence with language development: analogical reasoning is improved by labelling analogical items with words describing the relations that they contain. Conversely ... [more ▼]

Analogical reasoning shares a mutual influence with language development: analogical reasoning is improved by labelling analogical items with words describing the relations that they contain. Conversely, structural alignment, a core mechanism of analogical reasoning, allows the acquisition of novel words and the development of grammar (Gentner, 2010). Given those findings, some authors have taken interest in the analogical reasoning ability of children with language disorders, and specifically of children with Specific Language Impairment (SLI). Those children have worse performance than their age-matched peers without language disorders in linguistic or non-linguistic analogical tasks (Leroy, Maillart, & Parisse, 2014). Our aim here is to see if this weakness is due to their language disorders and if they use the same verbal strategies as their peers to solve an analogical task. To experience these assumptions, we use a perceptual analogical task following an A:B::C:D paradigm: participants have to find the relation between two geometric forms A and B and to apply it to the C term in order to find the D term among distractors. The distractors either share perceptual features with the C term, what creates a competition that shall be inhibited, or not. Moreover, children are faced with three interfering task conditions: one without any interfering task, one with an articulatory suppression secondary task and one with a tapping secondary task, which is used in order to measure the general dual task demands. Comparing the results of these conditions will allow us to evaluate the impact of language and verbal strategies on analogical reasoning in control and SLI children. [less ▲]

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See detailRepresentations about physical activity among firefighters. A study in Wallonie
Dubru, Gilles ULg; Gribomont, Antoine; Cloes, Marc ULg

Poster (2017, July)

Introduction To be a firefighter is a dangerous job. Many authors have found anxiety, stress, depression, sleep disorders, absenteeism and other deviant behaviors in this type of high-risk occupation ... [more ▼]

Introduction To be a firefighter is a dangerous job. Many authors have found anxiety, stress, depression, sleep disorders, absenteeism and other deviant behaviors in this type of high-risk occupation (Fullerton, Ursano & Wang, 2004 ; Carey, Al-Zaiti, Dean, Sessanna & Finnell, 2011 ; Elliot & Kuehl, 2007). Adopting an active lifestyle is therefore very important in reducing these health risks and thus maximizing the chances of staying healthy. It is for this reason that physical activity has an essential role for these people. According to this determining the place occupied by physical activity within the regional Walloon fire servicesseemed relevant. The first step should be to analyse the firefighters’ representations and lifestyle. Methods An online questionnaire (SurveyMonkey) was developed. It proposed a majority of closed-ended questions facing on age (38 ± 10.4 years), BMI (26.1 ± 3.7), gender (96.7% of men), rank, status (38.3% professional), PA representations and practices, well-being and self-esteem, job satisfaction, … We contacted one of the main firefighters association (FRCSPB) to reach a significant number of topics. 443 questionnaires were collected during a five weeks period. 394 were usable. 376 responses were needed to achieve a 95% confidence level with a 5% confidence interval based on all Belgian Firefighter. Results and discussion Results showed that firefighter showed positive representations about PA and were aware of the benefits of a regular practice on their health. Good stress management and cardiovascular endurance qualities were considerate as important in this profession. Nevertheless, subjects deplored a lack of maintenance of these qualities. The mean BMI of the subjects was above 26, indicating a slight overweight. Sedentary lifestyle, poor infrastructure, injuries due to lack of fitness allow us to suspect an insufficient training. Other factors were pointed out by the subjects (stress, absenteeism, deviant behavior…). Firefighters were generally satisfied with their job and considered that they have an acceptable quality of life. However lack of time, financial and human resources must not be a barrier to the practice of essential PA for those people who are directly related with danger. References Carey, M. G., Al-Zaiti, S. S., Dean, G. E., Sessanna, L., & Finnell, D. S. (2011). Sleep problems, depression, substance use, social bonding, and quality of live in professional firefighters. The international journal of occupational and environmental medicine, 53(8), 928-933. Doi: 10.1097/JOM.0b013e318225898f. Elliot, D. L., & Kuehl, K.S. (2007). The effects of sleep deprivation on firefighters and EMS responders: final report. International Association of fire Chiefs. Fullerton, C. S., Ursano, R.J.,& Wang, L. (2004). Acute stress disorder, posttraumatic stress disorder, and depression in disaster or rescue workers. The American Journal of Psychiatry, 161(8), 1370-76. [less ▲]

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See detailAgency and delinquency among adolescence during their transition to adulthood: what role in the desistance process?
Puglia, Rosa ULg; Glowacz, Fabienne ULg

Poster (2017, June 31)

Recent studies have shown that agency plays an important role in the desistance process. This variable allows the transition from delinquent identity to non-delinquent identity. However, despite ... [more ▼]

Recent studies have shown that agency plays an important role in the desistance process. This variable allows the transition from delinquent identity to non-delinquent identity. However, despite increasing literature about this topic, there is a lack of consensus regarding the role of this variable in the desistance process. Also, the way to measure this phenomenon remains unclear. In our study, agency is thought within a border framework, namely the understanding of all kind of behavior. According to the social cognitive theory, emotional and cognitive processes influence human behavior: emotions and thoughts that will define ways of acting and will motivate behavioral changes. Outcomes expectancies can be help or hinder for the concretization of behavioral change. We conducted a qualitative research among adolescents (aged 17-18) who are engaged in a delinquent trajectory. Our objective are to understand how these young in transition to adulthood leave delinquent lifestyle by evaluating to their life course and delinquent course. Each participant was interviewed with a semi-structured interview. To ensure that the interviews provided rich insights into participants’ reality, the interview was designed to elicit detailed information on relevant themes including identity, turning point, future and delinquency trajectory. Desistance was not explicitly questioned. All interviews were taperecorded and analyzed using IPA method (Smith, 2003). Mastery Scale (Pearlin, 1978), Causal Attribution Scale (Rossier, 2002), Hope Scale (Snyder, 1991) and University Rhode Island Change Assessment Scale (McConnaughy, 1983) were also administered. We see that the younths interviewed are at different stage in their desistance process. All of them, persistent or desistant, consider taking a hold on their lives. These results encourage thinking agency in the understanding of all kind of behavior. We should then take into account the beliefs and expectations of results as a variable mediating the relationship between agency and desistance. [less ▲]

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Peer Reviewed
See detailMean and variance of Dynamic Functional Connectivity in Parkinson’s Disease
Baquero Duarte, Katherine Andrea ULg; Guldenmund, Pieter; Rouillard, Maud ULg et al

Poster (2017, June 29)

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See detailHolomorphic cohomological convolution
Dubussy, Christophe ULg

Poster (2017, June 28)

In his thesis, T. Pohlen succeeded in defining a Hadamard product between holomorphic functions defined on star-eligible subsets of the Riemann sphere. We show how this theory is actually a particular ... [more ▼]

In his thesis, T. Pohlen succeeded in defining a Hadamard product between holomorphic functions defined on star-eligible subsets of the Riemann sphere. We show how this theory is actually a particular case of the holomorphic cohomological convolution, defined in a general way thanks to the integration map on complex Lie groups. [less ▲]

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See detailMUNIX vs TASPM
BENMOUNA, Karim ULg; MILANTS, Christophe ULg; WANG, François-Charles ULg

Poster (2017, June 27)

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See detailNF-kB-dependent regulation of TET1 in breast cancers
Canale, Annalisa ULg; Collignon, Evelyne; Al Wardi, Clémence et al

Poster (2017, June 26)

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See detailQuality control of insulin formulations: API , protamine and aggregates follow-up
Demelenne, Alice ULg; Napp, Aurore ULg; Lamalle, Caroline et al

Poster (2017, June 21)

The prevalence of diabetes is increasing every year and insulin preparations are mostly prescribed for treatment of both type 1 and type 2 diabetes. Since these biopharmaceutical formulations are ... [more ▼]

The prevalence of diabetes is increasing every year and insulin preparations are mostly prescribed for treatment of both type 1 and type 2 diabetes. Since these biopharmaceutical formulations are expensive and require a prescription, they are an important target for counterfeiting in developing countries. Therefore, there is a need for fast and efficient methods for quality control of biopharmaceutical products such as insulin formulations. A fully validated micellar electrokinetic chromatography (MEKC) method was developed for quantification of human insulin and NPH insulin (insulin combined with protamine) in formulations. The BGE used was made of 50 mM ammonium acetate (pH 9.0), 20 mM Sodium dodecyl sulfate and 13 % (v/v) acetonitrile and samples were introduced at the short capillary end allowing a separation of insulin and two major excipients (phenol and m-cresol) within 3 minutes. This method was compared with HPLC method using a mobile phase composed of water with 0.1% formic acid / acetonitrile with 0.1 % formic acid in gradient mode. Secondly a MEKC method was also optimized to analyze protamine peptides in insulin formulations. The major protamine peptides could be separated using a BGE made of 100 mM phosphate buffer (pH 2) with 50 mM Thesit®. This method was used to check conformity of protamine in commercially available formulations. Finally, different approaches were investigated in order to follow insulin aggregation. Indeed, insulin is prone to unfold when submitted to denaturating factors as temperature, ionic strength, agitation and pH. An accumulation of unfolds protein in bloodstream results in a high tendency to aggregate and form amyloid fibrils. A deposit of those fibrils in the subcutaneous tissue leads to a complication called “insulin-derived amyloidosis”. On the other hand, during its production, insulin is often subjected to extreme conditions making aggregation, as well as protein stability, important parameters to be controlled during its quality control. In this study, insulin aggregates were generated after optimization of incubation conditions (pH, temperature, agitation…). Those aggregates were then analyzed by size-exclusion chromatography (SEC) and capillary electrophoresis (CE). We showed that capillary gel electrophoresis (CGE) is a promising technique to analyze covalent aggregates of insulin due to the fact that it separates the aggregates according to their size and not to their size/charge ratio. The use of a laser-induced fluorescence detector was also found attractive to enhance the sensitivity of the method. [less ▲]

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See detailRelease of Neutrophils Extracellular Traps as a main trigger for asthma onset
Radermecker, Coraline ULg; Sabatel, Catherine ULg; Toussaint, Marie et al

Poster (2017, June 20)

Allergic asthma is an important Th2 associated immunopathology. Even if the pathology of the disease is well described, its etiology is still largely unknown. Nevertheless, some environmental factors like ... [more ▼]

Allergic asthma is an important Th2 associated immunopathology. Even if the pathology of the disease is well described, its etiology is still largely unknown. Nevertheless, some environmental factors like viral infections and exposition to low doses of lipopolysaccharide (LPS) strongly increase the risk of disease inception. Interestingly, these two particular risk factors both induce a strong recruitment of neutrophils into the lung. Recently, scientists highlighted the ability of neutrophils to form neutrophils extracellular traps (NETs) composed of a network of extracellular DNA associated to anti-microbial peptides. NETs release (or NETosis) is an important component in organism defence against pathogen invasion but has also been identified as initiator of pathophysiological conditions like erythematous systemic lupus, gout and diabetes. In this study, we investigated the role of NETs as potential asthma inducers in specific pro-Th2 environmental risk factors like respiratory viral infections and low LPS doses exposures (also known as hygiene hypothesis). First, we assessed the correlation between respiratory viral infection or low LPS exposure and NETosis using western blot and confocal microscopy analysis. An influenza A infection induced a strong NETs release between day three and seven after viral inoculation whereas exposition to low (100 ng LPS) but not to high (10 µg LPS) LPS doses also promoted NETosis within 24 hours following the exposition. Then we developed two mouse models, a virus-induced asthma model and a model of asthma promoted by exposition to low LPS doses. In these models, only previously infected mice or mice exposed to low LPS doses displayed all the characteristics of allergic asthma following sensitization and challenge to house dust mite (HDM). The role of NETs in asthma onset was then demonstrated using three NETosis inhibitors (DNAse, Cl-amidine and inhibitor of neutrophil elastase) in our models as infected or low LPS doses exposed mice exhibited strong decreased of all key asthma features when treated with NETs inhibitors compared to non-treated mice. Finally, to address how NETs could lead to a TH2 immune response, we analysed by flow cytometry the distinct subpopulations of lung dendritic cells (DCs) in our two mice models. We observed, during the NETs release phase, a recruitment of monocytic derived DCs (moDCs). In conclusion, we have demonstrated an unexpected role for NETs in asthma onset by recruiting lung moDCs. [less ▲]

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See detailDEVELOPMENT OF A MULTISCALE CONVECTIVE LABSCALE DRYER
Fraikin, Laurent ULg; Salmon, Thierry ULg; Léonard, Angélique ULg

Poster (2017, June 19)

The convective drying technology is currently used in many industries but the industrial process is frequently poorly mastered and some design security factors are used. The lack of optimized conception ... [more ▼]

The convective drying technology is currently used in many industries but the industrial process is frequently poorly mastered and some design security factors are used. The lack of optimized conception rules lead to large energy consumptions. In the same perspective, the use of superheated steam as drying fluid expands and requests the improvement of the knowledge about this specific drying process. For this goal, the PEP’s developed a new convective labscale dryer to conduct various studies. This article presents the new dryer called VESAC. [less ▲]

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See detailSTUDY ON THE STRUCTURAL EVOLUTION OF SEWAGE SLUDGE DURING CONVECTIVE DRYING
Li, Jie; Fraikin, Laurent ULg; Salmon, Thierry ULg et al

Poster (2017, June 19)

The structure of the sludge sample continues changing during drying as a result of the shrinkage phenomenon. Then the exchange area becomes smaller and the drying rate decreases. The sludge collected in a ... [more ▼]

The structure of the sludge sample continues changing during drying as a result of the shrinkage phenomenon. Then the exchange area becomes smaller and the drying rate decreases. The sludge collected in a wastewater treatment plant (Grosses Battes WWTP, Belgium) was chosen for both lab-scale experiment and pilot-scale experiment. X-ray macrotomography (resolution: 0.36 mm per pixel) and X-ray microtomography (resolution: 41 μm per pixel) were used to explore the structure evolution of the sludge bed and the single extrudate respectively. 2D cross-sections of the sludge bed and the single extrudate were acquired, which supply a convenient way to investigate the evolution of the structure. The results show that the structure of both the sludge bed and the single extrudate distinctly changes during the drying process. [less ▲]

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See detailMODELING MOISTURE TRANSFER OF MORTAR SUBMITED TO CONVECTIVE DRYING
Kahlerras, Loubna ULg

Poster (2017, June 19)

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See detailOptimiaztion of an electrophoretic approach for the screening and the development of new antithrombotic drugs
Farcas, Elena ULg; Bouckaert, Charlotte; Servais, Anne-Catherine ULg et al

Poster (2017, June 19)

The discovery of lead compounds that can modulate the activity of a biological target is essential to provide efficient pharmacological tools and to serve as starting points for new drug generations ... [more ▼]

The discovery of lead compounds that can modulate the activity of a biological target is essential to provide efficient pharmacological tools and to serve as starting points for new drug generations. Fragment-based drug discovery (FBDD) approach is an attractive tool for the identification of new selective inhibitors of a target of interest, but its success largely depends on the ability to develop screening bioassays capable to detect and gauge weak affinity binders. To achieve this goal, we investigated capillary electrophoresis (CE) for identifying and ranking fragments from an initial library. Indeed, due to its ability to evaluate weak interactions, CE seems to be promising for fragment-based screening. This technique is a powerful analytical tool with a unique separation mechanism, speed, efficiency and versatility. Its main advantages are low protein consumption, higher throughput compared to NMR and X-ray crystallography and the fact that screening can be carried out using native protein in physiological solution without the need of immobilization. We developed a proof of concept study on thrombin, a serine protease implicated in the coagulation cascade using affinity capillary electrophoresis (ACE) for ranking fragments from an initial library. For this study, we followed a probe ligand, benzamidine, and we investigated interactions with the target by monitoring the changes of its electrophoretic mobility upon binding. The first step of this study consisted in the optimization of the experimental conditions suitable for the CE method (target and probe ligand concentrations, separation buffer composition, voltage, separation effective length, target partial filling…). Then, numerous thrombin inhibitors with a wide range of inhibitory potency (i.e. Ki 200 µM – 5 nM) were tested to validate our system demonstrating the possibility to fish binders in the optimized conditions. We also checked the absence of non-specific binding with the target using the inactivated enzyme at the binding site. It is noteworthy that in this operating system (ACE assay), binding occurs in free solution using physiological buffers, thus preventing artifacts that may result from target immobilization, which is a requirement for some techniques such as SPR. [less ▲]

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See detailDEVELOPMENT AND VALIDATION OF A FAST SFC METHOD FOR THE ANALYSIS OF FLAVONOIDS IN PLANT EXTRACTS
Huang, Yang ULg; Jiang, Zhengjin; Fillet, Marianne ULg et al

Poster (2017, June 18)

Flavonoids from plants always show a wide range of biological activities [1-2]. In the present study, a rapid and highly efficient supercritical fluid chromatography (SFC) method was developed for the ... [more ▼]

Flavonoids from plants always show a wide range of biological activities [1-2]. In the present study, a rapid and highly efficient supercritical fluid chromatography (SFC) method was developed for the separation of 12 flavonoids. After careful optimization, the 12 flavonoids were baseline separated on a ZORBAX RX-SIL column using gradient elution. A 0.1% phosphoric acid solution in methanol was found to be the most suitable polar mobile phase component for the separation of flavonoids. From the viewpoint of retention and resolution, a backpressure of 200 bar and a temperature of 40 °C were shown to give the best results. Compared with a previously developed reverse phase liquid chromatography method, the SFC method could provide flavonoid separations that were about three times faster, while maintaining good peak shape and comparable peak efficiency. This SFC method was validated and applied to the analysis of five flavonoids (kaempferol, luteolin, quercetin, luteoloside, buddleoside) present in Chrysanthemum morifolium Ramat. from different cultivars (Chuju, Gongju, Hangju, Boju). The results indicated a good repeatability and sensitivity for the quantification of the five analytes with RSDs for overall precision lower than 3%. The limits of detection ranged from 0.73 to 2.34 μg/mL, while the limits of quantification were between 2.19 and 5.86 μg/mL. The method showed that SFC could be employed as a useful tool for the quality assessment of Traditional Chinese medicines (TCMs) containing flavonoids as active components. [less ▲]

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See detailNorth and South: Simultaneous observations of both Jovian poles from Juno and the Hubble Space Telescope
Bonfond, Bertrand ULg; Gladstone, George R.; Grodent, Denis ULg et al

Poster (2017, June 15)

On its elongated orbit, Juno flies over the poles of Jupiter every 53.5 days. The few hours before and after the perijove offer unique opportunities to observe the whole polar region from close distance ... [more ▼]

On its elongated orbit, Juno flies over the poles of Jupiter every 53.5 days. The few hours before and after the perijove offer unique opportunities to observe the whole polar region from close distance. However, Juno’s instruments can only observe one hemisphere at a time. Fortunately, the Hubble Space Telescope points its 2.4 m mirror toward the opposite hemisphere during some of these time intervals, providing truly simultaneous observations of both poles. We compare observations from Juno-UVS with Far-UV imaging sequences from the Hubble’s Space Telescope Imaging Spectrograph (STIS). Juno-UVS acquires spectrally resolved images of 17 ms exposure every 30 s Juno spin in the 70-205 nm wavelength range, while STIS can acquire about 270 consecutive 10 s images per HST orbit in the 130-160 nm range, but without any spectral resolution. Despite some differences, these datasets are similar enough in terms of spectral coverage, temporal and spatial resolution to allow direct comparisons. On Jupiter, the magnetic field is highly asymmetric and displays significant localized anomalies. Furthermore, most processes leading to auroral emissions depend on the magnetic field magnitude, either in the equatorial plane, in the acceleration regions, or in the upper atmosphere. Investigating morphological and brightness discrepancies between the two hemispheres provides precious clues on the current systems flowing in the magnetosphere and on the charged particles acceleration mechanisms. [less ▲]

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See detailEnvironmental controls of biogenic volatile organic compound emissions from a grazed grassland in Dorinne, Belgium
Michel, Colin ULg; Heinesch, Bernard ULg; Bachy, Aurélie ULg et al

Poster (2017, June 15)

Despite the growing interest for oxygenated volatile organic compounds (OVOC) over the last 15 years due to their role in the atmospheric chemistry, current knowledge about OVOC exchanges by grassland and ... [more ▼]

Despite the growing interest for oxygenated volatile organic compounds (OVOC) over the last 15 years due to their role in the atmospheric chemistry, current knowledge about OVOC exchanges by grassland and the environmental factors driving them still entails gaps. However, those ecosystems represent an important part of the total earth surface (13.37%). This study conducted on a grazed grassland therefore aims to quantify OVOC exchanges over full grazing seasons in order to understand the mechanisms behind these OVOC exchanges. The Eddy Covariance method was used for flux quantification, with a PTR-MS for the measurements of OVOCs mixing ratios. It took place within the activities of the CROSTVOC project (CROp Stress VOC) and therefore gives an important attention to the stress induced fluxes. BVOC flux measurements were also performed on a smaller scale by using all-teflon automated dynamic chambers covering a surface of 0.1 m² each. [less ▲]

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