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See detailEFFECT OF RAW MATERIAL PROPERTIES ON THE KINETICS OF IRON ORES GRANULATION
Jaimes Contreras, Rafael Antonio ULg; van Loo, Fréderic; Douce, Jean-François et al

Poster (2013, June 26)

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See detailImpacts of past Human disturbances on present day tree species assembly in the tropical forests of South-East Cameroon
Vleminckx, Jason; Doucet, Jean-Louis ULg; Daïnou, Kasso ULg et al

Poster (2013, June 25)

Non-random spatial distribution of trees is the result of both neutral and deterministic factors. Neutral models suggest that species within a community are equally competitive, with spatial structures ... [more ▼]

Non-random spatial distribution of trees is the result of both neutral and deterministic factors. Neutral models suggest that species within a community are equally competitive, with spatial structures mainly due to dispersal limitation. Deterministic (or non-neutral) models consider species assemblages as the result of what we name “induced spatial dependence”, where forcing (explanatory) variables shape diversity organization. However, deterministic models have often included habitat variables only, without considering human disturbance which we know enhances the competitive advantage of heliophytic (light-demanding) species and therefore the floristic composition of phytocenoses. Based on charcoal abundance in the soil (used as an indicator of anthropogenic perturbation), species abundance, and environmental data from a forest of south-east Cameroon, we applied modern variation partitioning methods to assess the relative impact of human disturbance on floristic patterns, controlling for purely spatial and habitat effects. Significant signals of human influence have been found so far, and a new collection of data should establish with a better precision the importance of the anthropogenic impact on tree species assemblages. [less ▲]

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See detailTime Delays in Gravitationally Lensed Quasars
Eulaers, Eva ULg; Magain, Pierre ULg; Sohy, Sandrine ULg

Poster (2013, June 25)

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See detailField investigation of subacute rumen acidosis prevalence in walloon dairy herds
Lessire, Françoise ULg; Knapp, Emilie ULg; Theron, Léonard ULg et al

Poster (2013, June 24)

Subacute ruminal acidosis (SARA) has been considered as a major metabolic disease in high producing dairy herds for years. However, different feeding practices However, different feeding practices and ... [more ▼]

Subacute ruminal acidosis (SARA) has been considered as a major metabolic disease in high producing dairy herds for years. However, different feeding practices However, different feeding practices and herd’s production levels are found in Wallonia. SARA prevalence in local herds was thus required 174 cows (164 Holstein and 10 Brown Swiss) out of 24 walloon herds were sampled from 2011 to 2012 for evaluation of their ruminal function. Selection of minimum 5 cows per herd was made on basis of days in milk (<150 DIM), or low milk fat % (F <3.2%), or fat/protein % (F/P≤1), or at farmer’s request (animal debilitated or chronically ill). Ruminal fluid was sampled 4-8 h after feeding using a Geishauser oro-pharyngeal probe, preventing saliva contamination. pH was measured by a portable pHmeter and values were reduced by 0.35 as proposed by Duffield (2004) because of the higher pH values in reticulum sampling site compared with rumenocentesis. Redox potential was determined by Methylene Blue Reduction Time (MBRT) and protozoa assessed by microscopy. Production values were obtained by the National Dairy Herds Improvement. Health scores were determined as described by Zaaier et al. (2001). RESULTS Mean production values ± SD of these animals (DIM: 106 ± 84) were 33.2 ± 8.9 kg milk, F = 3.47 ± 0.72%, P = 3.25 ± 0.25%, F/P = 1.07 ± 0.23. Mean BCS was 2.6 ± 0.6. Mean pH value ± SD was 6.50 ± 0.42. 10 animals (5.7%) from 6 herds were below 5.8, of which 4 cows from H8 (23 sampled cows). No result was < 5.5. MBRT was 4.16 ± 3.13 min. In 5 cows, value < 1min indicated a more amylolytic bacterial flora. In 24 samples, no reduction of MB occurred, demonstrating bacterial inactivity. Disappearance of large protozoa was observed in 6 samples, of which 5 abnormal specimens came from H8. No correlation between low pH values and F/P or %F could be found. CONCLUSION In no herd, prevalence was >25%, required for SARA diagnosis. Regarding these results, prevalence of SARA appears very low in Wallonia while on the opposite, ruminal flora inactivity seems far more common. [less ▲]

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See detailSpontaneous language of extremely premature children : Specific deficits in an informative language task
Martinez Perez, Trecy ULg; Grooteclaes, Vanessa; Docquier, Laurence et al

Poster (2013, June 24)

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See detailBiodegradable microspheres based on amphiphilic graft-copolymers of chitosan and polyesters
Demina, T; Drozdova, M.; Sevrin, Chantal ULg et al

Poster (2013, June 19)

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See detailCharacteristics of Pregnancy-Associated glycoprotein (PAG) like proteins in red deer
Okuyama, MW; Melo de Sousa, Noelita ULg; Beckers, Jean-François ULg

Poster (2013, June 19)

The Pregnancy-Associated glycoproteins (PAGs) constitute an asparatic proteinase family and are divided into 2 groups; bovine PAG-1 (boPAG-1) group and boPAG-2 group. PAGs have been detected in many ... [more ▼]

The Pregnancy-Associated glycoproteins (PAGs) constitute an asparatic proteinase family and are divided into 2 groups; bovine PAG-1 (boPAG-1) group and boPAG-2 group. PAGs have been detected in many domestic ruminant species and their biochemical characteristics were reported. However, information in wild ruminant, especially in deer species is scarce. The aim of this study is to investigate the characteristics of placental protein extracted in red deer (cervus elaphus); placental proteins which belong to each type of PAG group were identified in purification steps. Fresh frozen placenta (fetal cotyledon (FC): 2,247 g, maternal cotyledon (MC): 2,255 g respectively) was used as following purification step; protein extraction, acid precipitation (pH 4.5), Ammonium sulfate precipitation (SA0-40%, SA40-80%) and anion exchange chromatography (DEAE-cellulose 0M, 0,02M, 0,04M, 0,08M, 0,16M and 0,32M NaCl). In every step, Immunoreactivity against anti-PAG antisera was checked by Radioimmunoassay with using anti-PAG-1 antiserum (AS706) and anti-boPAG-2 antiserum (AS438). After Ammonium sulfate precipitation, much higher concentrations were gained in SA40-80% step (AS706: 5.35 mg/FCkg and 6.73 mg/MCkg, AS438: 24.79 mg/FCkg and 84.6 mg/MCkg) than SA0-40% step (AS706: 0.64 mg/FCkg and 0.79 mg/MCkg, AS438: 1.3 mg/FCkg and 9.34 mg/MCkg) in both part of cotyledon. After DEAE chromatography, the highest concentrations of protein against AS438 were gained in 0.08M NaCl step (5.49 mg/FCkg and 17.8 mg/MCkg) and concentrations of protein against AS706 were almost same in 0.08M NaCl (1.01 mg/FCkg and 1.35 mg/MCkg) and 0.16M NaCl (0.93 mg/FCkg and 1.34 mg/MCkg). In many ruminants such as cattle, sheep and goat, PAGs are contained largely in fetal cotyledon and most amounts of PAGs are belonging to PAG-1 group. On the other hand, in red deer, much larger amount of PAGs was obtained from maternal cotyledon. And stronger immunoreactivity with anti-boPAG-2 antisera was detected than with anti-PAG-1 antisera. This characteristic is similar to the results which were reported in pig and dromedary. Therefore, these results suggest that PAGs in red deer have different characteristics from other ruminant species. [less ▲]

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See detailOptimization of biodegradable microparticles for tissue engineering
Drozdova, M.; Demina, T.; Sevrin, Chantal ULg et al

Poster (2013, June 19)

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See detailEnantioselective synthesis of thioesters as substrates for high-through put screening assays of Penicillin Binding Proteins
Simon, Justine ULg; Zervosen, Astrid ULg; Bouillez, André ULg et al

Poster (2013, June 19)

Excessive utilization of beta-lactam antibiotics like penicillin has created drug-resistant strains in bacteria. One of the main mechanisms of resistance is the production of drug resistant Penicillin ... [more ▼]

Excessive utilization of beta-lactam antibiotics like penicillin has created drug-resistant strains in bacteria. One of the main mechanisms of resistance is the production of drug resistant Penicillin Binding Proteins (PBPs) and the over expression of these proteins. The transglycosidase and transpeptidase activities of PBPs catalyze the last two steps of peptidoglycan biosynthesis, which is unique to bacteria, and lies outside the cytoplasmic membrane. PBPs are interesting targets and efforts are still done to find new inhibitors. <br />A thioesterase activity has been described for various PBPs. For example, the thioester S2d is a substrate of PBP R39 of Actinomadura and of PBP2x of Streptococcus pneumoniae. The utilization of thioesters allows a rapid screening of active compounds in high-through put screening assays. Furthermore detailed kinetic studies using thioesters as reporter substrates are also possible. <br />Here we will present the enantioselective synthesis of the thioesters and their application as substrates in high through put screening assays. [less ▲]

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See detailGaining speed in molecular dynamics simulations by implicit representation of water and membrane molecules
Steinhauer, Sven ULg; Crowet, Jean-Marc ULg; Brasseur, Robert ULg et al

Poster (2013, June 19)

Molecular dynamics (MD) is an appropriate method for investigation of peptide-membrane systems and helps in analyzing results from experiments. In many cases, the ability of viral fusion proteins and ... [more ▼]

Molecular dynamics (MD) is an appropriate method for investigation of peptide-membrane systems and helps in analyzing results from experiments. In many cases, the ability of viral fusion proteins and toxins for destabilizing the membrane is due to their hydrophobic profile, leading to particular membrane insertion. By now, many relevant processes for drug design, toxicological studies and other fields of application, are not feasible by MD simulations, when each atom is represented over time. Processes such as protein folding, often take place above the time scales reachable by MD simulations, which are of the order of micro seconds. The necessary time effort for carrying out such simulations stays considerable and depends mainly on (1) the complexity of the simulated system (2) the simulated time scale (3) the simulation method (4) the efficiency of used hardware and software algorithms. Nowadays, MD simulations can still take weeks of calculation on high end computers. Impala is an implicit water and lipids forcefield, initially developed by our laboratory. Implicit forcefields replace water and/or lipid molecules by a couple of simple and partially precalculable equations. Using this method, thousands of water and lipid molecules can be replaced in MD simulations using Gromacs software. This leads to a considerable reduction of system complexity. The original Impala algorithm based on the assumption of rigid peptides and used a Monte Carlo algorithm with the aim of finding the insertion characteristics of these molecules in membranes. Our current work is the integration of the Impala forcefield into Gromacs, a freely accessible MD software. Replacing the aqueous and lipid phase atomic description in Gromacs MD by an implicit forcefield is supposed to lead to a gain of speed compared to full atomistic simulations. A gain of precision compared to Impala is expected, too. This will be achieved by turning molecules flexible, when implementing Impala into Gromacs. [less ▲]

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See detailMicroscopic techniques to study the interaction of new polymers within live cells
Smisdom, N.; Sanen, K.; Van Den Akker, N. et al

Poster (2013, June 19)

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See detailStudy of the specific interaction between fluorescent PDMAEMA and Platelets compared to Erythrocytes
Flebus, Luca ULg; Lombart, François ULg; Martinez, Lucia et al

Poster (2013, June 18)

Nowadays synthetic polymers provide more and more functionalities in the biomedical world, in particular as part of medical devices and drug delivery systems. Looking for new applications in the ... [more ▼]

Nowadays synthetic polymers provide more and more functionalities in the biomedical world, in particular as part of medical devices and drug delivery systems. Looking for new applications in the cardiovascular field, our attention has been focused on the well-known poly(2-(dimethylamino)ethyl methacrylate polymer (PDMAEMA). This synthetic polycation has particularly been studied as a potential DNA carrier to promote cell transfection. However and surprisingly enough relative few studies have been published in order to better understand its hemoreactivity under a free form (thus not based on “PolyElectrolyte Complex”), but also its biodistribution and clearance kinetics. In order to facilitate the in vitro and in vivo monitoring of this polycation and especially to follow its reactivity with whole blood we have labeled it with fluorescein adopting a new chemical route of synthesis. After its thorough purification and full-characterization (NMR, SEC, fluorescent spectroscopy), we followed its interaction with erythrocytes and platelets using flow cytometry. Dose-response curves were established in whole blood and within incubation times ranging between 5 min to 3 h. Considering the largest area and more negative Zeta potential developed by red blood cells compared to platelets, we initially hypothesized that RBC should interact more quickly and efficiently with the polycation. Unexpectedly, platelets presented a higher affinity for the polycation with a saturation binding curve whilst a linear profile was observed for the erythrocyte adsorption curve. Aggregometry analyses also revealed this phenomenon, although displaying a weaker effect in whole blood compared to washed platelets. Ongoing research seeks to understand the molecular mechanism of interaction of this polymer with platelets. [less ▲]

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See detailIn vitro study of fibroblasts (L929) and osteoblasts (MG-63) within networks differing in fiber density.
Lombart, François ULg; Alexandre, Diane ULg; de Bien, Charlotte ULg et al

Poster (2013, June 18)

Animal cells are typically cultivated in vitro on 2D surfaces therefore in conditions totally differing from their 3D in vivo environments. It is therefore really attractive to generate better in vitro ... [more ▼]

Animal cells are typically cultivated in vitro on 2D surfaces therefore in conditions totally differing from their 3D in vivo environments. It is therefore really attractive to generate better in vitro animal cell models where animal cells can adhere and proliferate within a 3D networks. When facing to a third dimension, the design of the scaffolds tailored to support the organization and communication of cells should favor at least cell adhesion, proliferation and differentiation, while promoting nutrient, gas (O2 / CO2) and waste product diffusion. In order to construct this in vitro model, we have compared the cell reactivity of two model cell lines fibroblaste L 929 and osteoblaste MG-63 within three 3D networks differing in fiber density. This parameter has been altered in order to increase progressively the total surface exposed to the cells, whilst increasing correspondingly the mean pore size and total porosity of the network, whilst keeping the same architecture and surface chemistry of the fibers within the scaffold. [less ▲]

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See detailSome natural products from aerial parts of Scrophularia imerethica
Getia, M; Mshvildadze, V; Dekanosidze, G et al

Poster (2013, June 17)

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See detailMasked hypertension is associated with a high cardiovascular risk in hypertensive kidney transplant recipients
XHIGNESSE, Patricia ULg; Saint-Remy, Annie ULg; BONVOISIN, Catherine ULg et al

Poster (2013, June 16)

Objective: High blood pressure (BP) is a major risk factor for graft function in kidney transplant recipients (KTs) Our aim was to evaluate BP control in the office, but also in the ambulatory and home ... [more ▼]

Objective: High blood pressure (BP) is a major risk factor for graft function in kidney transplant recipients (KTs) Our aim was to evaluate BP control in the office, but also in the ambulatory and home settings, in stable KTs, ali treated for hypertension, and to characterize patients with masked hypertension (MHT). Design and Method: Three BP measurement techniques were used in 70 late KT patients, (mean age 56.5 years; 43 males): ambulatory BP monitoring (ABPM-Spacelab 90207) office (OBP) and home BP monitoring (HBPM)- (OMRON M6). Carotid­ femoral pulse wave velocity was measured (Sphygmocor) as weil as a calcification score (arteries) and the systolic ankle brachial index (ABI) as recommended. The period since transplantation was 6.9±6.6 years, the mean GFR was 65.6±24±ml/min, Body Mass Index was 25.8±4.7 kg/m2 and the number of antihypertensive drug was 2.1±1 pills/d. Results: Uncontrolled hypertension (HTN) remained frequent in our treated population, 46 % were still hypertensive in the office, 39% using ABPM and 43% with HBPM. The proportion of MHT was 22% whatever the out-of-clinic method used, with more males, more overweight (BMI between, 25-30). lnterestingly when compared with controlled KTs (i.e both OBP and Daytime ABP controlled or both OBP and HBP controlled), using either ABPM or Home BP, patients with MHT had significantly higher PWV, a higher aortic augmentation pressure (AP), a higher calcification score and a higher ABI. However we did not find any significant impact of graft survival, immunosuppressive drugs, smoking habits, diabetes, or alcohol use. Conclusion: A high percentage of uncontrolled HTN was noted by OBP, but also by ABPM and HBPM despite antihypertensive treatment. MHT was frequently observed in KTs. This particular HT subtype, either defined by OBP vs ABPM or by OBP vs HBP, was significantly associated with major markers of arterial stiffness. So, MHT is associated with a high cardiovascular (cv) risk and therefore has to be manage to reduce incidence of cv events and graft loss. [less ▲]

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See detailPreliminary results of the Quality of Life Systemic Inventory for children in Pediatric Cystic Fibrosis: A tool for clinical interventions?
Toucheque, Malorie ULg; Etienne, Anne-Marie ULg

Poster (2013, June 14)

Objective: this study examined the generic and CF-specific QOL in CF children using a tool based on a modular clinical approach. Methods: Sample consisted of 12 CF children and 12 healthy children aged 8 ... [more ▼]

Objective: this study examined the generic and CF-specific QOL in CF children using a tool based on a modular clinical approach. Methods: Sample consisted of 12 CF children and 12 healthy children aged 8 to 12 years, matched by age and sex. The Quality of Life Systemic Inventory for Children (QLSI-C) assess both generic (20 items) and CF-specific (6 items) QOL. CF-specific module is empirically created from CFQ-R and discussion with medical staff. QLSI-C is a dynamic tool, using a VAS, which considers QOL (gap) like the difference between the present situation (state) and the expectations (goal). This difference is weighted by the importance (rank) that children assign for each life domains. QLSI-C is different from PedQoL, which consider QOL like an assessment of state score only. Results: Difference between CF and healthy children for the QOL score approached significance (F=3.63; p=0.07). Results by items show a significant difference for “autonomy” (F=4.30; p=0.05) and “frustration tolerance” (F=4.60; p=0.04) between the two groups. In addition, global scores in CF-specific module is correlated with global score in generic module for CF children (r=0.66 to 0.96). Assessment of QOL is the same for both generic (M=3.76) and CF-specific (M=3.76) module (p=0.53). Finally, descriptive statistics demonstrate that items which reflect the best QOL in CF children were based on social support unlike healthy children. Conclusion: QLSI-C is a clinical tool which distinguishes between children with CF and healthy children. Originality of this tool is strengthened by the consideration of individual life plan taking into account the particular situation of children with CF. [less ▲]

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See detailDistribution and identification of molecular interactions between tomato roots and bacterial biofilms
Debois, Delphine ULg; Jourdan, Emmanuel; Smargiasso, Nicolas ULg et al

Poster (2013, June 12)

Some non-pathogenic microorganisms evolving in the root micro-environment can trigger a positive effect on plant, increasing host defense against disease or/and directly inhibiting growth of pathogen in ... [more ▼]

Some non-pathogenic microorganisms evolving in the root micro-environment can trigger a positive effect on plant, increasing host defense against disease or/and directly inhibiting growth of pathogen in soil (1). To initiate both phenomena leading to biocontrol activity, microorganisms use plant exudates to grow on roots and to produce in-situ active compounds. In Bacilli, cyclic lipopeptides of the surfactin, iturin and fengycin families represent important antibiotics involved in biocontrol (2). Recent studies in microbiology allowed a better understanding of plant microorganism interactions but few has been done at the molecular level. In this study, MALDI MS imaging has been used to study the nature of the secreted lipopeptide molecules, their relative quantity and their distribution in the root’s environment.Disinfected tomato seeds were first germinated at 28°C in sterile conditions for germination. Seedlings were then placed in Petri dish on ITO glass slide recovered with a thin layer of plant nutritive solution containing 1,75% of agar and treated with freshly-grown cells of Bacillus amyloliquefaciens S499. Petri dishes were incubated at 28°C with a 16h photoperiod. Different growth / incubation durations were studied: 10/3; 13/7; 21/14 and 39/32. For MALDI imaging experiments, the ITO slide was removed from the agar and dried in a dessiccator under vacuum. (HCCA, 5mg/mL in ACN/0.2% TFA 70:30) was used as matrix. UltraFlex II TOF/TOF and Solarix FT-ICR mass spectrometers were used to record molecular cartographies and perform MS/MS experiments for structural analysis purposes. The average mass spectra recorded around the tomato root (2-3 mm on both sides of the root) showed that lipopeptides were major compounds detected on the agar. The relative intensity of lipopeptides families varied with respect to the age of the root/biofilm system. In the 10/3 system, 3 homologues of surfactins were essentially detected (C13, C14 and C15), with very few iturins and fengycins. Their localizations were identical, whatever the considered homologue. Then the production of iturin and fengycin families increases in older systems (13/7 and 21/14) and a novel homologue of surfactin is detected (C12). Some variations in localizations within families may be observed (around the root or at the close vicinity of it in function of the considered homologue or alkali adduct). Then for the oldest system we studied, iturins and fengycins are not detected anymore and the localization of surfactins is less precise. In the 39/32 system, we also detected unknown compounds at 986.6, 1000.6, 1014.7 and 1028.7 m/z. The mass range of these compounds allied to the mass difference between two consecutive ion peaks let us think that these unknown compounds could be a new lipopeptide family. Tandem mass spectrometry experiments, performed on the dried culture medium, allowed to partially sequence these new lipopeptides. MS/MS results allied to exact mass measurements and isotopic pattern simulation give good confidence in the chemical structure we suggest. Nevertheless, to fully identify these new variants of surfactin, micro-extractions followed by (LC)-nano-ESI-MS/MS using a LESA module are in progress. MALDI Mass Spectrometry Imaging becomes a tool to decipher inter-species molecular communication. [less ▲]

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See detailDe novo sequencing of unusual non tryptic peptides thanks to 4-sulfophenylisothiocyanate derivatization by post-source decay MALDI-MS.
Echterbille, Julien ULg; Quinton, Loïc ULg; Escoubas, Pierre et al

Poster (2013, June 11)

Introduction Due to the specificity of trypsin, tryptic peptides contain basic residues on the C-terminal side. This feature provides good ionization efficiency, and facilitates fragmentation processes ... [more ▼]

Introduction Due to the specificity of trypsin, tryptic peptides contain basic residues on the C-terminal side. This feature provides good ionization efficiency, and facilitates fragmentation processes. In the case of non tryptic peptides, the absence of basic residues at one extremity implicates lower fragmentation ratio and poor MS/MS spectra. Several methods have been developed to circumvent this drawback. Derivatization of peptides with compounds containing positive charge has been studied; Chen et al. (RCMS, 2004, 18, 191) demonstrated the simplification of CID spectra of tryptic peptides modified by 4-sulfophenylisothiocyanate. The result is a predominance of y-type ions. In this work, we evaluate the potential of SPITC for the de novo sequencing of unknown non-tryptic peptides containing disulfide bridges, i.e. peptide toxins from animal venoms. Methods 2µL of peptide solution (100 µM) were diluted in 6µL NH4HCO3 50mM (pH 8.7). As peptide toxins often contain disulfide bridges, reduction (2µL DTT 50mM, 1h at 56°C) and alkylation (2µL IAA 500mM, 1h in darkness at RT) of peptides were performed before the derivatization reaction. Peptides were then adsorbed on a C18 ZipTip micro-column followed by 10 µL of 4-sulfophenylisothiocyanate (SPITC) 50mM. The column was then incubated for 6h at 56°C. Peptides were washed by TFA 0.2% and eluted in 10µL 50/50 ACN/FA 0.1%, before being spotted in 2,5-DHB. MS experiments were performed using a Bruker Ultraflex II MALDI-TOF/TOF. FlexControl 3.0, FlexAnalysis 3.0, BioTools 3.2 and SequenceEditor 3.2 softwares (Bruker Daltonics, Bremen) were used for data acquisition and interpretation. Preliminary data According to our first results, SPITC derivatization allows in positive mode to direct the fragmentation thanks to the acidic character of the sulfonate moiety present on the modified molecule. Indeed, a large series of y-type ions is found in the CID spectra allowing determining easily large sequence tags. Moreover, the number of C-terminus ions (b- and a-type ions) decreases, which improve the simplification of MS/MS spectra. Due to this fragmentation pattern, SPITC derivatization is clearly valuable for the sequencing of peptides that are not described in databases (de novo sequencing). For example, animal venoms are composed of several hundreds of peptides that are poorly studied, up to now. These peptides display a high importance for pharmaceutical applications and their sequencing is, as a consequence, of prime interest. Peptide toxins, which are not resulting from an enzymatic digestion, are however difficult to sequence by classical MS/MS methods. In this work, we demonstrate that the modification of peptide toxins with SPITC reagent is suitable for “real” de novo sequencing. The method was applied to isolated peptides as well as chromatographic fractions that contain up to 30 toxins. The perspectives of this work rest on the study of the SPITC modified peptides in negative mode. We expect to obtain a better sensitivity due to the presence of the negative sulfonic acid group at the N-terminus extremity, and also interesting MS/MS spectra including mainly a- or b-type ions. The final challenge will be the application of the protocol to high throughput sequencing of peptide toxins from a large variety of animal venoms. Novel aspect De novo sequencing of unusual non-tryptic peptides thanks to 4-sulfophenylisothiocyanate derivatization by post-source decay MALDI-MS [less ▲]

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See detailRevue de la littérature - Dépression, activation comportementale et processus psychologiques
Wagener, Aurélie ULg; Blairy, Sylvie ULg

Poster (2013, June 11)

Depression is a syndrome from which 12% of men and 20% women suffer. Behavioral activation (AC) is a structured and brief psychotherapeutic procedure which has shown its efficacy in the treatment of ... [more ▼]

Depression is a syndrome from which 12% of men and 20% women suffer. Behavioral activation (AC) is a structured and brief psychotherapeutic procedure which has shown its efficacy in the treatment of depression. It follows two objectives: 1. increase engagement in activities associated with feelings of pleasure and/or control; 2. reduce involvement in activities maintaining negative affects or increasing their risk. This psychotherapeutic approach is composed of different tools such as psychoeducation and activities monitoring. After completing a BA program, subjects reported significantly less anxiety and depression symptoms, but studies haven't focussed on the improvement of psychological processes (PP) which are often biased in anxiety and depressive disorders (eg, avoidance and ruminations). This literature review presents PP on which BA could have an impact. [less ▲]

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See detailThe time evolution of O2(a1Δ) individual observations acquired by VIRTIS-M on board Venus Express
Soret, Lauriane ULg; Gérard, Jean-Claude ULg; Piccioni, Giuseppe et al

Poster (2013, June 10)

The O2(a1Δ) nightglow emission at 1.27 µm may be used as a tracer of the Venus upper mesosphere dynamics. This emission has been observed with VIRTIS-M-IR on board Venus Express. Previous studies showed ... [more ▼]

The O2(a1Δ) nightglow emission at 1.27 µm may be used as a tracer of the Venus upper mesosphere dynamics. This emission has been observed with VIRTIS-M-IR on board Venus Express. Previous studies showed that the emission maximum is statistically located close to the antisolar point at ∼96 km. This airglow results from the production of oxygen atoms on the Venus dayside by photodissociation and electron impact dissociation of CO2 and CO, which are then transported to the nightside by the subsolar to antisolar general circulation, where they recombine to create metastable O2(a1Δ) molecules. Their radiative deexcitation produces the O2(a1Δ) nightglow with a maximum near the antisolar point. However, VIRTIS individual observations indicate that the O2(a1Δ) nightglow emission is highly variable, both in intensity and location. Individual observations acquired every hour during a short period of time can also be grouped sequentially. Bright emission patches can thus be tracked and both their displacement and intensity variations can be analyzed. The peak intensity can vary from 1 to 6 megaRayleighs. We show that the emission peak moves with a mean value of ~80 m s-1, in good agreement with an earlier study by Hueso et al. (2008). The velocity vector in intensity and direction is evaluated approximately every 40 min. These displacements are highly variable, but some dynamical characteristics can be deduced from the observations. These results will be compared with other results of velocity determination in the upper mesosphere. [less ▲]

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See detailEmission of sulfur-containing volatiles from Arabidopsis thaliana (L.) Heynh Col-0 related to diamondback moth (Plutella xylostella (L.)) infestation
Hien, Truong Thi Dieu ULg; Delaplace, Pierre ULg; Francis, Frédéric ULg et al

Poster (2013, June 10)

Herbivore-infested plants often release a variety of volatile organic compounds (VOCs). Here, we studied the effects of feeding Plutella xylostella (L.) (0, 3, 9, 20 pest larvae within 0-4 h and 4-8 h ... [more ▼]

Herbivore-infested plants often release a variety of volatile organic compounds (VOCs). Here, we studied the effects of feeding Plutella xylostella (L.) (0, 3, 9, 20 pest larvae within 0-4 h and 4-8 h infestation, respectively) on the emission of sulfur-containing VOCs in Arabidopsis thaliana (L.) Heynh Col-0 (A.t. Col-0) by headspace solid-phase micro-extraction coupled to gas chromatography - mass spectrometry (HS-SPME-GC/MS). The analytical results showed that the relative emission of sulfur-containing metabolites increased significantly in Arabidopsis plants subjected to P. xylostella infestation according to the density and residence duration of pest larvae on shoot organs. The main compound from infested plants was dimethyl disulfide. We suggest that the correlations between the stress level (density and time infestation) and the sulfides observed in this study provide a means to understand the changes of VOCs profile of plant under chewer infestation. [less ▲]

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See detailFunctional screening of a winter and a spring genomic DNA libraries obtained from soils in a winter wheat crop
Stroobants, Aurore ULg; Portetelle, Daniel ULg; Vandenbol, Micheline ULg

Poster (2013, June 10)

Soils are very rich environments where the diversity of microorganisms is very high. These microorganisms play important role in the degradation of organic matter with enzymes able to degrade it. The aim ... [more ▼]

Soils are very rich environments where the diversity of microorganisms is very high. These microorganisms play important role in the degradation of organic matter with enzymes able to degrade it. The aim of this work is to discover by functional screening new enzymatic activities of microorganisms from soils collected in winter and spring in a winter wheat crop. The genomic DNA was extracted from both soils to construct two libraries in Escherichia coli. These libraries were then screened for several enzymes such as lipase, beta-glucosidase, cellulase, α-amylase,… At this time, 2 beta-glucosidases and 3 lipases have already been found in the winter library and 3 beta-glucosidases and 1 lipase in the spring library. Sequence analyses with the BLASTX program revealed that two beta-glucosidases have less than 65% of sequence identity with known beta-glucosidases, one have 64% of identity with a known beta-galactosidase and one have 59% of identity with a glycoside hydrolase. The fifth seems to be a phosphorylase kinase (54% identity) which have a glucoamylase domain responsible for the activity. This ORF is interrupted by a transposase. Three of the four lipases have less than 60% of sequence identity with known lipases/esterases. The fourth show 55% of identity with a known beta-lactamase. [less ▲]

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See detailStudy of bacterial diversity in the topsoil and below the hardpan in an agricultural soil by metagenomics following by two analysis pipelines
Stroobants, Aurore ULg; Lambert, Christrophe; Degrune, Florine ULg et al

Poster (2013, June 10)

On earth, Bacteria are ubiquitous and even present in extreme environments (pH, temperature,…). In soils in particular, bacteria are very abundant (up to 109 cells per gram of soil) but still poorly ... [more ▼]

On earth, Bacteria are ubiquitous and even present in extreme environments (pH, temperature,…). In soils in particular, bacteria are very abundant (up to 109 cells per gram of soil) but still poorly characterized. Thus, it is of paramount importance to use relevant study and analysis procedures to ensure that the results obtained closely reflect the real-life conditions. In the present work, we analyze the bacterial diversity in the topsoil and below the hardpan in an agricultural soil using the metagenomics approach, with the Ion Torrent PGM sequencer. The soil samples was collected at three depths : 10 cm (topsoil), 25 cm (topsoil above the hardpan) and 45 cm (below the hardpan), in a tilled and a no tilled plot. The taxonomic analysis of the reads obtained are carried out according to two different procedures with the RDP classifier program and with a confidence score threshold of 0 and 0.99. The 0 threshold is used to assign a species to all reads, each read being therefore assigned to its most closest known species. The threshold of 0.99 enables us to focus on reads being assigned to a species with a high degree of confidence. In this case, each read is assigned to the most specific rank having a confidence score higher than 0.99. The bacterial diversity was then compared between the different conditions. Results obtained demonstrate that the bacterial communities were not the same in the two horizons. For example, some classes of Acidobacteria were up to 11 fold more numerous in topsoil while others was until 12 fold more represented below the hardpan. The biomass and the bacterial diversity (Shannon index) were also greatly different between the two depths. [less ▲]

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See detailLong term measurements of VOC exchanges above a maize field at Lonzée (Belgium)
Bachy, Aurélie ULg; Aubinet, Marc ULg; SALERNO, Giovanni ULg et al

Poster (2013, June 10)

For the last decades, VOC had arisen scientifict interest due to their important role in the atmospheric chemistry and their final impact on air pollution and climate change. Terrestrial ecosystems being ... [more ▼]

For the last decades, VOC had arisen scientifict interest due to their important role in the atmospheric chemistry and their final impact on air pollution and climate change. Terrestrial ecosystems being the main VOC source, evaluation of current and future biogenic VOC emissions through VOC exchange modeling is thus necessary to better estimate future climate and assess future air pollution risks. BVOC exchanges depend on edaphic variables and are plant species specific. Therefore, their modeling and global budget evaluation requires a comprehensive understanding of production and exchange dynamics under a wide panel of climatic conditions and ecosystems, which necesserily implies BVOC exchange measurements under varied conditions. In that perspective, forest and non pastured grasslands have been largely studied for the last decade, but knowledge about BVOC fluxes from croplands remains still scarce. As a consequence, crop species-specific standard emissions that feed bottom-up BVOC emission models are still often assigned to a default value that is in addition kept constant for the entire growth season, although recent research has shown that plant phenology, acclimation and stress can drastically influence BVOC emissions. To help filling this knowledge gap, we run a project that aims to study VOC fluxes from two major croplands, maize (2nd most important culture worldwide) and winter wheat (1st most important culture worldwide), and a pastured grassland. We present here a specific study focussing on the VOC exchanges between a maize field and the atmosphere. VOC fluxes were measured at ecosystem-scale during the whole 2012 growing season using the eddy covariance by mass-scaning technique with a proton-transfer-reaction mass spectrometer. Together with VOC fluxes, we also recorded a wide set of ancillary data including CO2 fluxes, meteorological variables and biomass evolution. As far as we know, we are the first study dealing with BVOC measurements on maize at ecosystem scale and spanning all the phenological stages of the crop. Although first results show half-hourly bidirectionnal exchanges among all the preselected compounds, in average methanol is the greatest emitted VOC, followed by green leaf volatiles. Acetic acid and acetaldehyde are the greatest taken up VOC. Small isoprene and monoterpene fluxes are also observed. A diurnal pattern is found for all those VOC, with greater emission/uptake during the day, suggesting a flux dependence on environmental parameters. Influence of environmental controls, biomass evolution (including growth primary production) and phenology on fluxes is currently under investigation. Our research allows to quantify BVOC exchanges by a maize field throughout a whole growing season. Hence, obtained results will refine the understanding of the BVOC exchanges mechanisms by including both environmental and phenological parameters. Such results are expected to be very useful for BVOC modeling, especially for oxygenated compounds such as methanol. [less ▲]

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See detailCharacterization of new bacterial glycoside hydrolases isolated from agricultural soils using a functional metagenomic approach
Biver, Sophie ULg; Dubois, Benjamin; Stroobants, Aurore ULg et al

Poster (2013, June 10)

Microorganisms play key roles in soil ecosystem functioning, notably through their ability to degrade plant cell wall polymers. For this, bacteria and fungi produce various enzymes such as cellulases ... [more ▼]

Microorganisms play key roles in soil ecosystem functioning, notably through their ability to degrade plant cell wall polymers. For this, bacteria and fungi produce various enzymes such as cellulases, xylanases, glucosidases, esterases or laccases. Finding new enzymes hydrolyzing cellulose, hemicellulose or lignin is not only interesting for a better understanding of the roles of the soil microflora still largely unknown but these enzymes are also useful for various biotechnological applications such as the production of renewable energy from lignocellulosic material. So here, we used a functional metagenomic approach to isolate new bacterial β-glucosidases, which were then biochemically characterized. The new enzymes were identified by functional analysis of agricultural-soil metagenomic libraries hosted in Escherichia coli and screened on medium containing esculin. After sequence analysis and preliminary estimation of the activity of the new β-glucosidases using p-nitrophenol derivatives on intact bacterial cells, the coding sequences of three of them were cloned into a bacterial expression vector so as to overproduce and purify them by affinity chromatography. The chosen enzymes show only 52-64% sequence identity to known family 3 (GH3) or 1 (GH1) glycoside hydrolases of different phyla (Actinobacteria, Acidobacteria and Proteobacteria). Analysis of the E. coli cells expressing each of them revealed that both GH1 proteins (ASEsc9 and ASEsc10) are thermophilic enzymes more active at mildly acidic to neutral pH while the GH3 enzyme (ASEsc6) is an alkaline, mesophilic, β-glucosidase also displaying xylosidase activity. Their coding sequences have been cloned in fusion with a carboxy-terminal His-tag and placed under the control of the IPTG-inducible promoter of the pET-30b vector. The proteins will be overproduced and purified for further characterization. [less ▲]

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See detailInfluence of the mode of walk on walking speed in multiple sclerosis: are you walking comfortably?
PHAN BA, Remy ULg; DELRUE, Gaël ULg; Pierard, Sébastien ULg et al

Poster (2013, June 10)

Introduction : Walking speed (WS) is the most frequent gait variable taken into account when measuring gait dysfunction in neurological diseases. Influences of the mode of walk instructed to the subject ... [more ▼]

Introduction : Walking speed (WS) is the most frequent gait variable taken into account when measuring gait dysfunction in neurological diseases. Influences of the mode of walk instructed to the subject, i.e. « as fast as possible » (AFAP) or « at a comfortable pace » (PrP) have not been well characterized in multiple sclerosis (MS). Objectives : to compare those 2 mode of walk in a population of persons with MS (pMS) and healthy volunteers (HV). Methods: WS was measured with a new automated device along a 25 foot distance (T25FW) as part of a multimodal evaluation of gait in an MS ambulatory department. Results: Baseline demographics between HV and pMS were comparable. Our first results demonstrate that (i) WS is obviously significantly higher in AFAP than in PrP both for pMS and HV (p < 0.001 for all comparisons) and (ii) the relative difference between AFAP and PrP WS is significantly higher in HV than in pMS (p < 0.001). The AFAP-PrP WS correlation is higher in pMS (r = 0.87, p < 0.001) than in HV (r = 0.51, p < 0.001). Finally, the relative difference between AFAP and PrP WS is significantly and negatively correlated with the PrP WS in HV (r = -0.41, p < 0.001) and pMS with mild to moderate disability (EDSS 0-3.5, r = -0.49, p < 0.01) but not in pMS with high disability (EDSS 4-5.5, r = 0.008). Conclusions : these results suggests that heatlhy subjects have access to a higher range of PrP WS than pMS and questions the regulation of PrP WS that might be under psychological or behavioural influences. The demonstration of a lower PrP-AFAP difference in MS suggests that pMS are either adopting a natural WS closer to their maximum WS, or alternatively that they can’t reach their maximum WS because of neurological impairments. Our results also emphasize the importance of the instructed mode of walk in the quantification of gait disorders both for routine clinical practice and clinical trials. [less ▲]

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See detailIdentification of chemical probes and signaling pathways for the orphan GPCR GPR27
Dupuis, Nadine ULg; Gilissen, Julie ULg; Pirotte, Bernard ULg et al

Poster (2013, June 06)

The largest family of membrane receptors is represented by G protein-coupled receptors (GPCRs), which are characterized by 7 transmembrane domains. Even if marketed drugs currently target only 10% of all ... [more ▼]

The largest family of membrane receptors is represented by G protein-coupled receptors (GPCRs), which are characterized by 7 transmembrane domains. Even if marketed drugs currently target only 10% of all GPCRs, they represent more than 30% of all small molecules based therapies. The physiological and pathophysiological role of a GPCR is defined by its expression pattern, signaling pathway and specific ligand[1]. GPCRs which have not yet been associated to a physiological ligand are called orphan GPCRs and represent ~100 of the ~370 human non-odorant GPCRs[2]. This project aims at identifying and developing pharmacological tools for GPR27 (SREB1), one of these orphan receptors. GPR27 has recently been shown to have a role in the regulation of insulin promoter activity and insulin secretion[3]. Nevertheless, the pharmacology of GPR27 remains elusive and the lack of appropriate pharmacological tools dramatically restricts the understanding of its function and its validation as a drug target. Thus, we plan to study its signaling pathway and to develop screening methods that will allow us to identify small molecules able to interact with GPR27. These are important steps toward understanding its function and evaluating GPR27 as a potential drug target, for instance in insulin-related metabolic disorders such as type II diabetes or in other pathologies where it might be involved. References 1) Wise, A., et al. (2002). Drug discovery today, 7, 235 2) Fredriksson, R., et al. (2003). Molecular pharmacology, 63, 1256 3) Ku, G. M., et al. (2012). PLoS genetics, 8, e1002449 [less ▲]

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See detailThe coping strategies to fight against the food insecurity in the Republic of Niger
Andres, Ludovic ULg; Lebailly, Philippe ULg

Poster (2013, June 06)

During the last decade, the Niger’s population has been affected by the food crisis (2001, 2004-2005, 2008, 2010-2011). Each year, she is subjected to many structural and temporary shocks. The structural ... [more ▼]

During the last decade, the Niger’s population has been affected by the food crisis (2001, 2004-2005, 2008, 2010-2011). Each year, she is subjected to many structural and temporary shocks. The structural shocks are caused by the chronicle difficulties (income) while the temporary shocks are tied at the "natural" disasters such as the hydrometeorological disasters, demographic crisis. The risk that the people fall in a state of food insecurity because of structural and temporary shocks is characterized by food vulnerability. The food vulnerability is defined as “the analysis of coping strategies and reactions faced with the structural or/and temporary shocks, if the coping strategies are not effectives, the people have in a temporary or structural food vulnerability” (Andres L. and Lebailly Ph., 2011). The target of this paper is to demonstrate the diversity of coping strategies in the different departments of Niger. The database is created as from an annual survey realized by the Early Alert System (EAS) and the Statistical National Institute of Niger (INS). This survey characterizes the state of food insecurity of households of Niger. The investigations of the household are based on stratified sampling. It exists two levels: region and enumeration areas. The investigations of the household are based from the database of the population census of 2001. This population census has determined the “enumeration areas”. These “enumeration areas” are defined as a “geographical area of 200 households on average” (INS, 2007). The sample of this investigation is established from a significant sample a point of view of the departments of Niger. The time period studied is spread the 2008 at 2011. The results have demonstrated that the departments of Tchintarabaden, Abalak, Tessaoua and Magaria have weakest number of collective meals, and the highest percentage of household practicing of selling the goods and land. Furthermore, the Niger’s population develops many strategies to struggle against the shocks. [less ▲]

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See detailLife history traits related to hydraulic functioning in 211 African tropical woody species
Morin-Rivat, Julie ULg; Fayolle, Adeline ULg; Doucet, Jean-Louis ULg et al

Poster (2013, June 06)

In the context of global change understanding the interactions between plant ecology and plant physiology remains a crucial issue. In this study we aimed at analyzing the vascular characteristics involved ... [more ▼]

In the context of global change understanding the interactions between plant ecology and plant physiology remains a crucial issue. In this study we aimed at analyzing the vascular characteristics involved in the ecological traits of woody species from the northern Congo Basin. We crosschecked three databases: the botanical inventories (857 spp.) and the database of life history traits (464 spp.) produced during the CoForChange project, and the anatomical database Inside Wood (761 spp. and genera for tropical Africa). A total of 211 shared species was obtained. We performed correspondence analyses between the tangential diameter of the vessel lumina (40-43), the number of vessels per mm² (46-50) and five life history traits: leaf phenology, light requirement, seed dispersal, tree size and wood density. Species were distributed along a gradient from species with numerous small vessels to species with few large vessels. This distribution was correlated to a gradient in leaf phenology and light requirement: from evergreen shade-tolerant species to deciduous non-pioneer and pioneer light-demanding species. Dispersal followed this distribution in a lesser extent: from zoochoria to autochoria via anemochoria. Finally, a gradient in size was observed, from small shrubs to tall trees, as well as a gradient in wood density, from dense to light woods. We conclude that the ecological traits of the African tropical woody species are closely related to their hydraulic functioning. The strategies adopted by plants regarding light and water availability can thus be deduced from their vascular characteristics. On this basis we anticipate that climate change will foster light-demanding tree species as better competitors than shade-tolerant species, especially as drought stress is concerned. Further research is needed to increase the input of wood anatomy in explaining the life history traits in African tropical species. [less ▲]

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See detailL’abeille à miel au Gabon: de la cueillette à l’apiculture
Fabre Anguilet, Edgard ULg

Poster (2013, June 05)

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See detailValidation d'une méthode d'analyse quantitative de l'équol dans le lait par UPLC-MSMS
Daems, Frédéric ULg; Jasselette, Christophe; Lognay, Georges ULg et al

Poster (2013, June 04)

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See detailHot gas distribution in the wind of ζ Pup and ζ Ori
Herve, A.; Rauw, Grégor ULg; Nazé, Yaël ULg

Poster (2013, June 01)

We have developped a new X-ray modelling code based on embedded shocks which computes synthetic spectra as a function of plasma temperature, abundances and localization of the X-ray emitting shell in the ... [more ▼]

We have developped a new X-ray modelling code based on embedded shocks which computes synthetic spectra as a function of plasma temperature, abundances and localization of the X-ray emitting shell in the wind. We have also included a proper treatment of the radial dependence of the X-ray opacity of the cool matter as well as a treatment forthe Forbiden Inter combination Resonance (FIR) lines of He-like ions. Our code combines several synthetic spectra in order to fit all the lines of an X-ray spectrum simultaneously and coherently. Our results on two O-type stars ζ Pup and ζ Ori reveal non-porous winds with a mass loss rate consistent with studies in the optical domain as well as non-solar abundances for the CNO elements as expected for evolved stars. More important, the X-ray plasma starts emitting close to the stellarsurface. An improved version of our code allowing an analysis of the radial dependence of the hot gas filling factor reveals for ζ Ori a non continuity of the X-ray emission regions associated to high values of the hot gas filling factor. [less ▲]

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See detailSpectral Modelling with Interaction Effect of the Binary System Spica
Palate, Matthieu ULg; Koenigsberger, G.; Harrington, D. et al

Poster (2013, June 01)

Massive binary systems are crucial to improve our knowledge of the fundamental properties of massive stars, and synthetic spectra modelling with theoretical stellar atmospheres is commonly used in ... [more ▼]

Massive binary systems are crucial to improve our knowledge of the fundamental properties of massive stars, and synthetic spectra modelling with theoretical stellar atmospheres is commonly used in deriving some of these properties. However, the current stellar atmosphere models are designed for single spherical stars and therefore neglect interaction effects that occur in close binaries. We have developed a combined model that uses the TIDES code for computing the surface and the velocity field and the CoMBiSpeC model for the synthetic spectrum computation. This 2-in-1 model allows us to account for the interactions between the stars. We can now simulate the impact of the binarity on the spectra and refine the physical parameters of the binary systems. This model is presented here through the example of the spectral computation of Spica. In this particular system, the strongest effects due to the binarity appear in the line profile variations and the shape of the radial velocity curve. [less ▲]

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See detailThe Chandra Delta Ori Large Project: Occultation Measurements of the Shocked Gas in the Nearest Eclipsing O-Star Binary
Corcoran, Michael; Nichols, Joy; Leutenegger, Maurice et al

Poster (2013, June 01)

Delta Ori is the nearest massive, single-lined eclipsing binary (O9.5 II+OB, P=5.7324d). High resolution X-ray spectrometry offers a unique opportunity to geometrically measure the dynamics of the shocked ... [more ▼]

Delta Ori is the nearest massive, single-lined eclipsing binary (O9.5 II+OB, P=5.7324d). High resolution X-ray spectrometry offers a unique opportunity to geometrically measure the dynamics of the shocked gas around the primary star. We summarize our recent campaign of phase-constrained high-resolution X-ray spectra obtained with the CHANDRA/HETGS plus high-precision photometry with MOST. These observations provide local measurement of the distribution of the embedded, X-ray emitting shocks in the wind of an O star via radial velocity variations and occultation effects, along with standard f/i ratio diagnostics, and enable us to look for correlations with the broad-band photometric variability. We discuss how these observations can help determine the primary star's clumping-corrected mass loss rate, and resolve critical uncertainties in our understanding of the connection between stellar and mass loss parameters. [less ▲]

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See detailA HYDROGEN BOND INFLUENCES THE 5-HT1A/D4 SELECTIVITY OF WAY-100635 ANALOGUES: AN IN SILICO APPROACH
Dilly, Sébastien ULg; Liégeois, Jean-François ULg

Poster (2013, June)

WAY-100635 is widely used in vitro and in vivo as an antagonist of 5-HT1A receptors. In terms of pharmacological tools and pharmacological investigations, the ideal reference molecule would be highly ... [more ▼]

WAY-100635 is widely used in vitro and in vivo as an antagonist of 5-HT1A receptors. In terms of pharmacological tools and pharmacological investigations, the ideal reference molecule would be highly selective for its target over other related and non-related targets. However WAY-100635 displays affinity for and activity at D4 dopamine receptors, and that "off-target" activity confounds its use in pharmacological studies, particularly when both receptors are present. In this context, we carried out various chemical modifications of the WAY-100635 structure in order to improve its 5-HT1A versus D4 selectivity. An important increase of selectivity was obtained when the basic side chain of WAY-100635 was replaced by a 4-phenylpiperazine or a 4-phenyl-1,2,3,6-tetrahydropyridine moiety. In contrast, the introduction of nitrogen atoms in the acyl group decreased the selectivity by reducing the affinity for 5-HT1A receptors, on the one hand, and enhancing the affinity for D4 receptors on the other hand. In order to explain the reduced 5-HT1A/D4 selectivity of aza-derivatives, the binding modes of the compounds were explored by docking analysis on homology models of the two receptors. It appears that the formation of an additional hydrogen bond within D4 receptors could be the key of the decreased selectivity. These results will be very helpful for developing molecules with an improved 5-HT1A/D4 selectivity. [less ▲]

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See detailUse of VIS- and nir-infrared spectroscopy to determine cheese properties
Troch, Thibault ULg; Vanden Bossche, Sandrine; De Bisschop, Céline et al

Poster (2013, June)

Cheese processing is one of the possibilities of farm diversification. From 30 cow milks were made 60 cheeses on which several parameters were measured and on which NIR spectra were obtained. Our results ... [more ▼]

Cheese processing is one of the possibilities of farm diversification. From 30 cow milks were made 60 cheeses on which several parameters were measured and on which NIR spectra were obtained. Our results show that cheese spectra could be discriminated between different ripening times of cheeses and the access to pasture or not for the animals which had produced the milk from which the cheese was made. Moreover, highly significant correlations were obtained for the color and the texture of cheeses between the values measured in the laboratory and the NIR spectra. [less ▲]

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See detailCaracterización de los factores implicados en la resistencia/sensibilidad a la infección del virus influenza en modelos murinos Mx-negativos
Casanova Bustos, Tomas Ronaldo ULg; Daniel, Desmecht; Mutien, Garigliany

Poster (2013, June)

DBA/2J mice and C57BL/6J are two extremes in terms of susceptibility to influenza A virus among Mxnegative mouse strains. Several research teams focused on the factors explaining this difference, mainly ... [more ▼]

DBA/2J mice and C57BL/6J are two extremes in terms of susceptibility to influenza A virus among Mxnegative mouse strains. Several research teams focused on the factors explaining this difference, mainly by genetic approaches using Recombinant Inbred Lines between those two strains. Several candidate-genes have been proposed, but it was not possible to determine their importance. We chose a phenotypic approach, by dissecting each stage of influenza A infection virus in mice of each line, aiming at identifying critical differences between C57BL/6J and DBA/2J. Preliminary observations suggest that either the viral infection of the airway epithelium of DBA/2J is more productive, either alveolar macrophages from C57BL/6J are more efficient in viral particles phagocytosis, or a combination of these two mechanisms. We isolated and cultured tracheal cells, pneumocytes and alveolar macrophages from both strains of mice to determine the permissiveness of the cells of the respiratory tree, quantify the specific receptors of influenza A virus and to compare the alveolar macrophage phagocytic abilities. We have demonstrated a greater presence of α2,3 receptors on alveolar macrophages and tracheal cells of DBA/2J and a higher in vitro viral amplification on DBA/2J respiratory cells. [less ▲]

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See detailIsolation and cultivation of cellulolytic and xylanolytic bacteria and molds extracted from the gut of the termite Reticulitermes santonensis (3DV.1.14)
Tarayre, Cédric ULg; Bauwens, Julien ULg; Mattéotti, Christel et al

Poster (2013, June)

Biofuel production can be based on the use of agro-residues, consisting in a complex lignocellulosic structure which is not easily hydrolysable. The digestive tract of the termite Reticulitermes ... [more ▼]

Biofuel production can be based on the use of agro-residues, consisting in a complex lignocellulosic structure which is not easily hydrolysable. The digestive tract of the termite Reticulitermes santonensis contains a diversified microflora able to hydrolyze the wood components. Bacteria, molds and protists form efficient consortia, able to break the lignocellulosic complex by producing enzymes, such as xylanases and cellulases. Our purpose is the isolation of microbial strains from termite guts in order to evaluate their potential for hydrolysis of lignocellulosic materials. Termites were fed using different diets chosen to improve the xylanolytic and cellulolytic microflora: wood, microcristalline cellulose (added with lignin or not), α-cellulose (added with lignin or not) and birchwood xylan. Then, dissections were realized to isolate the potential xylanolytic and cellulolytic strains. This approach led us to isolate and to study several strains of bacteria (Bacillus sp. strain CTGx and Chryseobacterium sp. strain CTGx) and molds (Trichoderma virens strain CTGx and Sarocladium kiliense strain CTGx). These microorganisms were able to hydrolyze starch, xylan, cellulose, carboxymethylcellulose, esculin, β-glucan and Whatman® filter paper. They can produce glucose and xylose monomers and oligomers which can be further fermented to produce bioethanol. [less ▲]

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See detailDo we plagiarize more often when the content of the to-be-remembered material is emotional?
Beaufort, Aline ULg; Brédart, Serge ULg; Perfect, Timothy J. et al

Poster (2013, June)

This study examined the impact of the emotional content on rates of cryptomnesia using the Brown and Murphy (1989) paradigm. In a first stage, dyads of young (mean age = 21.5 years) participants (n = 96 ... [more ▼]

This study examined the impact of the emotional content on rates of cryptomnesia using the Brown and Murphy (1989) paradigm. In a first stage, dyads of young (mean age = 21.5 years) participants (n = 96, 48 females) were asked to generate alternately words corresponding to an emotional category (i.e.,“positive”, “negative” or “neutral”). One week later, participants were instructed (1) to recall the items that were generated by themselves and not by the other member of the dyad (Recall-Own task), (2) to generate four news items (Generate-New task) for each category and (3) to assign confidence ratings to their responses. About 17% of responses were plagiarisms in the recall-own task and the percentage almost reached 9% in the Generate-New task. No significant effects of valence were found on rates of plagiarism in Generate-New task nor on the confidence ratings assigned to the participants' responses. However, cryptomnesia was significantly higher for positive than neutral items while it did not differ significantly across negative and neutral items. Confidence ratings were lower for plagiarized responses than for correct responses but these ratings were higher for plagiarized items than for intrusions. [less ▲]

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See detailIMMUNE AND NEURO-ENDOCRINE RESPONSES OF GRAVID EURASIAN PERCH TO CHRONIC CONFINEMENT AND SOCIAL ISOLATION STRESS
Mandiki, SMN; Douxfils, Jessica; Massart, Sophie et al

Poster (2013, June)

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See detailLack of generalization as explicative factor of morphosyntactic difficulties in children with SLI: a longitudinal study
Leroy, Sandrine ULg; Parisse, Christophe; Marchat, Aurélie et al

Poster (2013, June)

Background. Constructivist approach (Goldberg, 2006; Tomasello, 2003) postulates that children build their linguistic system from their own linguistic experience. To be productive with their language ... [more ▼]

Background. Constructivist approach (Goldberg, 2006; Tomasello, 2003) postulates that children build their linguistic system from their own linguistic experience. To be productive with their language, children have to generalize construction schemas to never heard items. Because children with SLI show limited morphosyntactic creativity and variability, we hypothesized that they would have difficulties to generalize their construction schemas, which would hinder their access to the most abstract level of the linguistic competence. Our aim was to test whether children with SLI had more difficulties than children with TLD to generalize a schema to new items. Methods. Seven children with SLI matched with 6 children TLD based on linguistic age were recorded for this study. Two steps were repeated at three different moments spread out three years. The first step consisted in a recording of a parent/child interaction at their house. All interactions were transcribed and analyzed. The second step consisted in the creation of two tasks from each child’s own productions: an utterance repetition task and a priming task. Tasks were individualized. Items were created from schemas considered as “acquired” and schemas considered as “non-acquired”. Results. Priming task. Current statistical analyses revealed a significant “Group” effect, a significant “Time” effect and a no significant “Group” by “Time” effect. Analyses revealed a significant “Structure” effect and a significant “Group” by “Structure” effect. Difference between the two groups was more marked for items with “non-acquired” schemas. Repetition task. The same results were obtained; except for “Time” variable (no significant effect). Discussion. The two groups had more difficulties to generalize non-acquired schemas to new items, but children with SLI seemed to have more difficulties, which could mean that their productivity with new schemas was more hindered. Consequently, results are compatible with our hypothesis suggesting that children with SLI have more difficulties for generalizing a schema to new items. [less ▲]

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See detailTowards the improvement of a rhizosecretion-based recombinant protein production system: Developing protease-depleted lines of Arabidopsis thaliana.
Lallemand, Jérôme ULg; Désiron, Carole ULg; Périlleux, Claire ULg et al

Poster (2013, June)

Besides traditional production systems, such as bacteria, yeasts and mammal cells, plants can now be used to produce eukaryotic recombinant proteins. Their advantages as hosts for protein production ... [more ▼]

Besides traditional production systems, such as bacteria, yeasts and mammal cells, plants can now be used to produce eukaryotic recombinant proteins. Their advantages as hosts for protein production include correct post-translational modifications, low cost of maintenance and no risk of contamination by human pathogens. Targeting heterologous proteins to the extracellular space is required for the correct folding of complex proteins and makes harvesting and purification easier. However, the quantity and the quality of recombinant proteins have been proved to be reduced by the action of endogenous co-secreted proteases. In this study, we aimed at identifying active root-secreted (rhizosecreted) proteases in the model plant Arabidopsis thaliana. Their activity was assayed by in vitro degradation of a target protein (Bovine Serum Albumine, BSA) in a range of pH. The protease classes involved in BSA degradation were evaluated by inhibitor-based assays that revealed serine proteases as the major class involved in this degradation in any tested conditions. As a first step towards identification, and subsequent silencing, of the most active members of this class, rhizosecreted proteases are being analyzed by the “Activity-Based Protein Profiling” approach. [less ▲]

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See detailBrain metabolic dysfunction in Capgras syndrome during Alzheimer’s disease: a positron emission tomography study
Jedidi, Haroun ULg; Daury, Noémy; Cappa, Rémi et al

Poster (2013, June)

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See detailAnalysis of the interactions of xylose-based bolaforms with model membranes
Nasir, Mehmet Nail ULg; Monhonval, Pierre; Legrand, Vincent et al

Poster (2013, June)

Sugar-based surfactants are natural and biocompatible compounds. Among sugar-based surfactants, there is an increase of interest for the xylose-based bolaforms because of their potential applications in ... [more ▼]

Sugar-based surfactants are natural and biocompatible compounds. Among sugar-based surfactants, there is an increase of interest for the xylose-based bolaforms because of their potential applications in pharmaceutical and cosmetic fields and of their original physicochemical properties. Xylose-based bolaforms have interfacial and membrane-interacting properties making them potential molecules for drug delivery systems. For this work, we chemically synthetized by metathesis in the presence of Grubbs I catalyzer, a novel symmetric bolaform composed of two xylose polar heads connected by an ether link to a hydrocarbon chain having 18 carbon atoms with an unsaturation (BolaX). We were able to obtain two bolaforms differing only at the level of the anomeric configuration of the xylose moieties, or orBolaX). The surface activities of both compounds were analyzed. The anomeric configuration  gives interfacial properties at the air-water interface contrary to the  one. The interactions of the BolaX with model membranes were then analyzed in order to determine if it can be used for drug delivery systems. Our results show that BolaX were able to interact and insert within lipid monolayers containing phospholipids and sterols. In order to have informations at the molecular level of these interactions, another model membrane, called multilamellar vesicles (MLVs), containing phospholipids and sterols with or without  BolaX were prepared. Both MLVs were analyzed by the means of the FTIR spectroscopy. In parallel, we have calculated the interaction energy of the  BolaX with different lipid molecules by the means of the Hypermatrix method developed at our laboratory. Moreover, the insertion of the  BolaX within the lipid bilayers was simulated using our IMPALA method. Taking together, our findings indicate that BolaX would be a potential candidate for drug delivery systems because of its surface active properties and its ability to insert within membranes. [less ▲]

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See detailConnectome-based classification of BDNF Met allele carriers
Ziegler, Erik ULg; Foret, Ariane; Mascetti, Laura ULg et al

Poster (2013, June)

Secretion of brain-derived neurotrophic factor (BDNF) is essential for synaptic plasticity in the central nervous system during neurodevelopment [Huang]. A common human non-synonymous SNIP in the BDNF ... [more ▼]

Secretion of brain-derived neurotrophic factor (BDNF) is essential for synaptic plasticity in the central nervous system during neurodevelopment [Huang]. A common human non-synonymous SNIP in the BDNF gene (Val66Met, rs6265) decreases activity-dependent BDNF release in neurons transfected with the human A allele (Met-BDNF). We reasoned that the persistent differential activity-dependent BDNF release implied by this polymorphism should also be associated with differences in adult brain structure. The study population comprised 36 healthy subjects (aged 18-25): 15 (9 male) were identified as carrying the Met allele (“Met carrier” group) and 21 (9 male) were homozygotes for the Val allele (“Val/Val” group). The groups did not vary significantly in IQ, age nor scores for a battery of psychological tests. A high-resolution T1-weighted image (sMRI), 7 unweighted (b=0) and a set of diffusion-weighted (b=1000) images using 61 non-collinear directional gradients were acquired for each subject. The processing workflow relied on several pieces of software and was developed in Python and Nipype. The sMRIs were segmented using the automated labeling of Freesurfer [Desikan] and further parcellated using the Lausanne2008 atlas into 1015 regions of interest (ROIs) [Cammoun]. DWIs were corrected for image distortions (due to eddy currents) using linear coregistration functions from FSL [Smith]. Fractional anisotropy maps were generated, and a few single-fiber (high FA) voxels were used to estimate the spherical harmonic coefficients (order 8) of the response function from the DWIs [Tournier]. Then orientation distribution functions were obtained at each voxel. Probabilistic tractography was performed throughout the whole brain using seeds from subject-specific white-matter masks and a predefined number of tracts (300,000), see Fig. 1. The tracks were affine-transformed into the subject's structural space with Dipy [Garyfallidis]. Connectome mapping was performed by considering every contact point between each tract and the outlined ROIs (unlike in [Hagmann]): the connectivity matrix was incremented every time a single fiber traversed between any two ROIs. We trained a Gaussian Process Classifier [Rasmussen] (interfaced by PRoNTo [Schrouff]) on these connectivity matrices. The accuracy and generalization ability of the classification were assessed with a leave-one-subject-out cross-validation procedure. With this linear kernel method weights were also obtained indicating the contribution to the classification output (in favor of either genotypic group) of each edge in the network. The same method was employed to discriminate features related to the subjects' gender and genotype for the ADA gene. The classifier was able to discriminate between Val/Val and Met carriers with 86.1% balanced accuracy. The predictive value for the Val/Val and Met carrier groups were 94.4% (p=0.001) and 77.8% (p=0.003), respectively. In Fig. 2 the weights obtained by the classifier are visualized as edges in the brain network. For the classifier trained to identify gender or the subjects' ADA genotype, the global accuracy reached 63.9% (n.s.) and 58.3% (n.s.) respectively. Using high-resolution connectome mapping from normal young healthy human volunteers grouped based on the Met allele of the BNDF gene, we show that the BDNF genotype of an individual can be significantly identified from his structural brain wiring. These differences appear specific to this allele; no such difference could be found for the polymorphism in the ADA gene, or even for gender. We propose that the decreased availability of BDNF leads to deficits in axonal maintenance in Met carriers, and that this produces mesoscale changes in white matter architecture. Acknowledgements: the FNRS, the ULg, the Queen Elisabeth Medical Foundation, the Léon Fredericq Foundation, the Belgian Inter-University Attraction Program, the Welbio program, and the MCITN in Neurophysics (PITN-GA-2009-238593). Cammoun L. et al. (2011), ‘Mapping the human connectome at multiple scales with diffusion spectrum MRI’, J Neuroscience Methods, 203:386–397. Desikan R.S. et al. (2006), ‘An automated labeling system for subdividing the human cerebral cortex on MRI scans into gyral based regions of interest’, Neuroimage, 31:968-980. Hagmann P. et al. (2008), ‘Mapping the structural core of human cerebral cortex’, PLoS Biology, 6:e159 Huang E.J., Reichardt L.F. (2001), ‘Neurotrophins: roles in neuronal development and function’, Annual Review of Neuroscience, 24:677-736. Garyfallidis E. et al. (2011), ‘Dipy - a novel software library for diffusion MR and tractography’, 17th Annual Meeting of the Organization for Human Brain Mapping. http://nipy.sourceforge.net/dipy/ Rasmussen C.E. (2006), Gaussian processes for machine learning. Schrouff J. et al. (2012), ‘PRoNTo: Pattern Recognition for Neuroimaging Toolbox’, 18th Annual Meeting of the Organization for Human Brain Mapping. http://www.mlnl.cs.ucl.ac.uk/pronto Smith S.M. et al. (2004), ‘Advances in functional and structural MR image analysis and implementation as FSL’, Neuroimage, 23 Suppl 1:S208-S219. Tournier J.D., et al. (2007), ‘Robust determination of the fibre orientation distribution in diffusion MRI: non-negativity constrained super-resolved spherical deconvolution’, Neuroimage, 35:1459-1472. [less ▲]

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See detailDynamic Modeling and control of a pilot CO2 postcombustion capture plant
Léonard, Grégoire ULg; Cabeza Mogador, Bruno; Belletante, Ségolène et al

Poster (2013, June)

A dynamic model of a post-combustion capture pilot plant is developed using Aspen Plus Dynamics. An innovative process control strategy is studied for regulating the water balance of the process. A ... [more ▼]

A dynamic model of a post-combustion capture pilot plant is developed using Aspen Plus Dynamics. An innovative process control strategy is studied for regulating the water balance of the process. A washing section where the flue gas from the absorber is washed with cold water is included to the process in order to reduce the emissions of amine to the air. Control of the water balance in the solvent loop is successfully achieved by changing the washing water temperature. In previous publications regarding CO2 capture pilot plants, the regulation of the water balance always required a water make-up flow which appears here as unnecessary. Rejection of disturbances and different load reduction scenarios are tested to confirm the efficiency of this strategy. Potential operational problems of this control strategy are identified and solved. [less ▲]

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See detailChange in viability of Acetobacter senegalensis cells during gluconic acid fermentation at high temperature
Zarmehrkhorshid, Raziyeh ULg; Shafiei, Rasoul ULg; Thonart, Philippe ULg

Poster (2013, June)

Introduction: Gluconic acid (GA) is a multifunctional carbonic acid with versatile applications in food, beverage and pharmaceutical industries. Although the production of GA and its derivative dating ... [more ▼]

Introduction: Gluconic acid (GA) is a multifunctional carbonic acid with versatile applications in food, beverage and pharmaceutical industries. Although the production of GA and its derivative dating backs decades, but use of this acid and its derivatives due to high prices is currently restricted. Using a thermotolerant bacterium in production of this acid at high temperature can provide a new option for industrially cost effective production. However, fermentation productivity may be negatively affected by factors (such as high temperature) leading to loss of cell viability. Objectives: In this study, the ability of a thermotolerant bacterium, Acetobacter senegalensis, in gluconic acid production at high temperature and its survival responses to some factors including temperature and carbon sources were evaluated. Materials and Method: Different batch fermentation processes were carried out at 38 °C, and then cell viability (total dehydrogenase activity) and culturability were assessed using flow cytometry and plate counting techniques, respectively. Results: A. senegalensis oxidized 95 g/L of glucose to gluconic acid at 38 °C. In exponential growth phase, cells were less subjected to damages; but upon transition of cells to stationary phase, cell viability and culturability reduced. Consequently, due to the lack of dehydrogenase activity the specific rate of glucose consumption and gluconic acid production decreased dramatically. High temperature (38 °C), oxidation of high amount of glucose and accumulation of inhibitory compounds (possibly gluconic acid) were dominant inducers leading cells into a viable but non-culturable state (VBNC) during the course of stationary phase. In contrast, presence of ethanol accompanied with glucose, and low incubation temperature assisted in resuscitation of senescent cells of stationary phase. Conclusions: A. senegalensis is able to produce gluconic acid at 38 °C. But, due to entrance of cells into VBNC state during stationary phase, the performance of batch fermentation is adversely affected. [less ▲]

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See detailTo Be Afraid or to Be Proud? The Impact of Emotional Valence and Response Efficacy on Persuasion in Anti-Drink Driving Advertising
Hazee, Simon ULg

Poster (2013, June)

Social marketers traditionally use negative emotions although they can be ineffective on persuasion. However, few social marketers use positive emotions while commercial marketers use them extensively ... [more ▼]

Social marketers traditionally use negative emotions although they can be ineffective on persuasion. However, few social marketers use positive emotions while commercial marketers use them extensively. Accordingly, this study aims to understand the impact of positive versus negative emotional appeals on persuasion of young adults in a road safety context through a 2 (pride versus fear) × 2 (low versus high response efficacy) factorial design. ANCOVA results show the significant role of both types of emotions on persuasion, regardless the level of response efficacy. Surprisingly, “fear” is more persuasive than “pride”. Hence, social marketers should consider using emotions when building future models and communication campaigns targeting young adults. Future research should investigate under which conditions ‘pride’ can be the most persuasive. [less ▲]

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See detailThe hidden half of flowering
Bouché, Frédéric ULg; Mistiaen, Kevin ULg; D'Aloia, Maria ULg et al

Poster (2013, June)

Flowering is one of the most important developmental steps in plant life cycle and is therefore tightly controlled by environmental cues. The involvement of the aerial part of the plant in the molecular ... [more ▼]

Flowering is one of the most important developmental steps in plant life cycle and is therefore tightly controlled by environmental cues. The involvement of the aerial part of the plant in the molecular mechanisms leading to floral transition is well documented while participation of the roots received less attention. Nevertheless, the induction of flowering by photoperiod is known to involve systemic signals that move in phloem sap towards sinks, throughout the plants, including the roots. Transcriptomic analysis of roots tissues during the floral induction of flowering by a single long day of in Arabidopsis thaliana by a single long day allowed us to identify a large number of differentially expressed genes. How mutations We subsequently selected in some candidate genes affect plant development - including root architecture and flowering time - is being to analyze their flowering timefurther analyzed. Further analysis of those genes will permit us to unravel their role in the flowering induction process. [less ▲]

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See detailThermal adaptation of the ribosomal chaperone trigger factor
Godin, Amandine ULg; Schmidpeter, Phillip; Schmid, Franz et al

Poster (2013, June)

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See detailResearch of New Enzyme Producing Strains in the Gut of the Termite Reticulitermes santonensis
Tarayre, Cédric ULg; Bauwens, Julien ULg; Mattéotti, Christel et al

Poster (2013, June)

Termites contain a complex microflora inside of their guts. Inferior termites contain bacteria, mycetes and protists that interact to degrade vegetable components. These strains act as consortia to break ... [more ▼]

Termites contain a complex microflora inside of their guts. Inferior termites contain bacteria, mycetes and protists that interact to degrade vegetable components. These strains act as consortia to break natural materials by secreting various enzymes. Our aim was the isolation and cultivation of microorganisms in order to produce new enzymes that can be further used in green chemistry. Termites were fed with different diets: pinewood, microcristalline cellulose (added with lignin or not), α-cellulose (added with lignin or not) and birchwood xylan. Then, dissections were realized to isolate interesting strains. All the microorganisms were subjected to enzyme assays. That technique allowed us to isolate and to cultivate various strains of bacteria, molds and protists. Three strains of bacteria, two strains of molds and one strain of protist were isolated and displayed different enzymatic activities. The bacteria Bacillus subtilis strain ABGx, Bacillus sp. strain CTGx and Chryseobacterium sp. strain CTGx displayed amylase, cellulase and xylanase activities. The molds Trichoderma virens strain CTGx and Sarocladium kiliense strain CTGx were also able to produce those enzymes. However, the protist Poterioochromonas sp. was found to produce only amylase. In conlusion, the termite gut is a complex culivation medium that provides a habitat for many microorganisms that show interesting enzymatic activities. [less ▲]

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See detailOscillations in the basal ganglia: illustration of a cellular effect at the network level
Dethier, Julie ULg; Drion, Guillaume; Franci, Alessio et al

Poster (2013, June)

Parkinson’s disease (PD) is a neuro-degenerative pathology affecting the basal ganglia (BG), a set of small subcortical nervous system nuclei. The hallmark of the disease is a dopaminergic denervation of ... [more ▼]

Parkinson’s disease (PD) is a neuro-degenerative pathology affecting the basal ganglia (BG), a set of small subcortical nervous system nuclei. The hallmark of the disease is a dopaminergic denervation of the striatum, al- tering information patterns along movement-related ganglia-mediated path- ways in the brain. Severe motor symptoms result from the pathological state: tremor at rest, bradykinesia, akinesia, and rigidity. The transition to the disease state correlates with a switch in the firing mode of the neurons in the BG, from tonic pacemaker activity to burst firing. At the network level, macro-electrode recordings reveal excessive oscillations in the beta (8- 30Hz) frequency band. The oscillations generation mechanism and their functional role remain under debate. We propose a network model where a cellular mechanism controls the dynamical state of the network. In our model, the oscillatory state impacts the neural information processing prop- erties of the network. The network model predicts that a single decrease of the dopaminergic level in the parkinsonnian condition switches the network into an abnormal oscillatory dynamical and globally insensitive state. The brief dopaminergic increase prior to voluntary movements suppresses beta oscillations to drive the network to a conductive state to sensory processing and cognition. [less ▲]

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See detailMultivariate pattern interpretation using PRoNTo
Schrouff, Jessica ULg; Rosa, Maria; Rondina, Jane et al

Poster (2013, June)

Recently, machine learning models have been applied to neuroimaging data, allowing to make predictions about a variable of interest based on the pattern of activation or anatomy over a set of voxels. In ... [more ▼]

Recently, machine learning models have been applied to neuroimaging data, allowing to make predictions about a variable of interest based on the pattern of activation or anatomy over a set of voxels. In addition, they might lead to an increased sensitivity to detect the presence of a particular mental representation compared to univariate methods such as the General Linear Model (GLM). Application of these methods made it possible to decode the category of a seen object or the orientation of a striped pattern seen by the subject. They also allowed classification of patients and healthy controls and could therefore be used as a diagnostic tool due to their ability to predict the class of an unseen sample. The main disadvantage of multivariate machine learning models is that local inference with respect to the brain neuroanatomy is complex: although linear models generate weights for each voxel, the model predictions are based on the whole pattern and therefore one cannot threshold the weights to make regional statistical inferences as in univariate analysis. In the present work, we developed a methodology based on a labelled anatomical template (e.g. AAL or Brodmann) to display a smoothed version of the model weights and compute a ranking of the regions according their contribution to the predictive model. This work is distributed in PRoNTo (Pattern Recognition for Neuroimaging Toolbox), a user-friendly toolbox, making machine learning models available to every neuroscientist. [less ▲]

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See detailBiomass hydrolyzing enzymes identified by functional screening of a metagenomic library from algal biofilms.
Martin, Marjolaine ULg; Biver, Sophie ULg; Barbeyron, Tristan et al

Poster (2013, June)

Biomass hydrolyzing enzymes are increasingly searched for the production of biofuels and renewable chemical compounds using biomass. Microorganisms living on algaes are an interesting reservoir of biomass ... [more ▼]

Biomass hydrolyzing enzymes are increasingly searched for the production of biofuels and renewable chemical compounds using biomass. Microorganisms living on algaes are an interesting reservoir of biomass hydrolyzing enzymes, as they are in constant interaction with algal biomass. Therefore, we are interested in looking for some of those enzymes synthesized by the microflora living on the surface of the brown algae Ascophyllum nodosum. Algae samples were collected in the winter 2012 and a microbial DNA extraction method was developed. The whole extracted microbial genomes of the microorganisms living on the algae were restricted, inserted in a cloning vector and ligated products were used for transformation of cultivable Escherichia coli host cells. This metagenomic library was then screened for diverse enzymatic activities (lipolytic enzymes, cellulases, beta-glucosidases, alpha-amylases, arabinanases, xylanases and proteases) on agar plates with specific substrates. Five putative lipolytic enzymes, one cellulase and one beta-glucosidase were identified. Sequence analysis revealed low (<50%) sequence identities with known enzymes sequences, meaning new enzymes from unknown genomes have been discovered. To our knowledge this is the first functional screening that was realized with a metagenomic library from algal biofilms and this is the first cellulase identified by marine metagenomics. A second library has been constructed from algae sample from summer 2012 and is currently being screened. New enzymatic tests are being developed for the identification of enzymes degrading specific algal polysaccharides like agarases, carrageenases, alginate lyases, laminarinases,… Those very specific enzymes aren’t well known yet, and our metagenomic approach will probably help us to identify new families and structures of those algal biomass hydrolyzing enzymes. [less ▲]

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See detailMaladie hémolytique néonatale modérée due à un anti‐RH46
MONFORT, Mélanie ULg

Poster (2013, June)

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See detailAu delà des nombres réels
Kreusch, Marie ULg

Poster (2013, June)

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See detailROBOT-ASSISTED SURGERY: THE MULTICENTER BELGIAN EXPERIENCE
GOFFIN, Frédéric ULg; Traen, koen; TIMMERMANS, Marie ULg et al

Poster (2013, June)

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See detailA nap to recap: Reward strengthens relational memory during daytime sleep
Igloi, Kinga; Gaggioni, Giulia Alice ULg; Eryilmaz, Hamdi et al

Poster (2013, June)

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See detailValidation of an accelerometer-based approach to quantify gait events
Boutaayamou, Mohamed ULg; Schwartz, Cédric ULg; Stamatakis, Julien et al

Poster (2013, June)

Researchers rarely provide solid performance and validation information about their acceleometer-based approaches to human gait analysis. We present here a novel signal processing and analysis algorithm ... [more ▼]

Researchers rarely provide solid performance and validation information about their acceleometer-based approaches to human gait analysis. We present here a novel signal processing and analysis algorithm that automatically extracts four consecutive fundamental events of walking: heel strike (HS), toe strike (TS), heel off (HO), and toe off (TO). In addition, we validate this accelerometer-based technique by comparing these extracted gait events with those obtained by a kinematic 3D analysis system and a force plate, used as gold standards. [less ▲]

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See detailA Pathway closely related to the D-tagatose pathway of Gram-Negative Enterobacteria Identified in the Gram-Positive Bacterium Bacillus licheniformis
Van Der Heiden, Edwige ULg; Delmarcelle, Michaël ULg; Lebrun, Sarah ULg et al

Poster (2013, June)

We report the first identification of a gene cluster involved in d-tagatose catabolism in Bacillus licheniformis. The pathway is closely related to the d-tagatose pathway of the Gram-negative bacterium ... [more ▼]

We report the first identification of a gene cluster involved in d-tagatose catabolism in Bacillus licheniformis. The pathway is closely related to the d-tagatose pathway of the Gram-negative bacterium Klebsiella oxytoca, in contrast to the d-tagatose 6-phosphate pathway described in the Gram-positive bacterium Staphylococcus aureus. [less ▲]

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See detailUnravelling the roles of lysine acetylation by Elp3 during inner ear development
Mateo Sanchez, Susana ULg; Delacroix, Laurence ULg; Laguesse, Sophie ULg et al

Poster (2013, May 31)

Given the importance of acetylation homeostasis in controlling developmental processes, we planned to investigate its role in inner ear formation and focused our attention on Elp3 acetyl-transferase, a ... [more ▼]

Given the importance of acetylation homeostasis in controlling developmental processes, we planned to investigate its role in inner ear formation and focused our attention on Elp3 acetyl-transferase, a member of the Elongator complex recently implicated in neurogenesis. We first analysed the spatio-temporal pattern of ELp3 mRNA expression and showed that it was expressed in the early otocyst at E11.5 and persisted later in the sensory epithelium of the cochlea, the spiral ganglion, the stria vascularis and the vestibule. To unravel functions of Elp3 in the inner ear, we used conditional knock-out mice in which Elp3 gene is deleted from early otocyst (Elp3 cKO). We submitted these mice to a battery of vestibular testing and found significant abnormalities. Besides, the auditory brain stem response of Elp3 cKO indicated that these mice are severely deaf. At the cellular level, we detected some defaults in the planar orientation of the auditory hair cell bundle. In addition, the length of the kinocilium was significantly reduced both in vestibular and cochlear hair cells from Elp3 cKO mice. We were also able to demonstrate an increased level of apoptosis in the Elp3 cKO spiral ganglion at E14.5 leading to a reduced number of fibers innervating the cochlear hair cells as well as a reduced number of their synaptic ribbons. In conclusion, our results clearly show a role for Elp3 both in hearing and balance. We plan to go deeper in the mechanisms involved through the identification of the proteins that are targeted for acetylation by Elp3. [less ▲]

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See detailIn vitro and in vivo Characterization of Adult Bone Marrow Neural Crest Stem Cells
Coste, Cécile ULg; Neirinckx, Virginie ULg; Manguette, Jérôme et al

Poster (2013, May 31)

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See detailINFUSION OF THIRD-PARTY MESENCHYMAL STEM CELLS (MSC) AFTER KIDNEY AND LIVER TRANSPLANTATION: A PHASE I-II, OPEN-LABEL, CLINICAL STUDY (EudraCT 2011-001822-81 & NCT01429038)
DETRY, Olivier ULg; DELBOUILLE, Marie-Hélène ULg; LECHANTEUR, Chantal ULg et al

Poster (2013, May 30)

MSC cells have demonstrated significant immunosuppressive effects in various in vivo and in vitro studies. This study aims to be the first evaluation of the safety and tolerability of third party MSC ... [more ▼]

MSC cells have demonstrated significant immunosuppressive effects in various in vivo and in vitro studies. This study aims to be the first evaluation of the safety and tolerability of third party MSC infusion after cadaveric kidney and liver transplantation in a prospective phase I-II study, taking advantage of our centre expertise and experience in MSC use in graft-versus-host disease (GVHD) after bone marrow transplantation and using an already functioning GMP-compliant laboratory producing clinical-grade MSC. Secondary end-points will help to evaluate the immunosuppressive potential of MSC after organ transplantation, and the opportunity to develop larger randomised, controlled, phase III trials. After successful transplantation, 10 liver and 10 kidney transplant recipients under standard immunosuppression (tacrolimus, MMF, steroids) will receive an intravenous infusion of 1.5-3x106/kg of third-party MSC on post-operative day 3±2. These patients will be prospectively compared to 10 liver and 10 kidney recipients who meet the inclusion criteria but deny MSC infusion. Safety will be assessed by recording side effects, including opportunistic infections and cancers. Immunosuppressive potential will be evaluated by rejection episode rates, by graft/patient survivals, by immunohistology of 3-months kidney and 6-month liver graft biopsies and by in vitro evaluation of the immunity profile of the recipients. In a second step, reduction (kidney) and progressive weaning (liver) of immunosuppression will be attempted in recipients who received MSC. This ongoing study is supported by research grants from the CHU of Liège, University of Liège, and by the Senior Clinical Research Grant from ESOT. The first patients were included and treated in early 2012, and final results expected in late 2013. [less ▲]

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See detailNovel phenolic glycolipids: antioxidant activity and effect on membrane models
Sainvitu, Pauline ULg; Nasir, Mehmet Nail ULg; Draguet, Florian et al

Poster (2013, May 30)

Aromatic glycolipids are of both medical as well as pharmaceutical interest. Antimicrobial, antiviraland antiinflammatory activities have been reported (Otto, 2000, Journal of Molecular Catalysis B ... [more ▼]

Aromatic glycolipids are of both medical as well as pharmaceutical interest. Antimicrobial, antiviraland antiinflammatory activities have been reported (Otto, 2000, Journal of Molecular Catalysis B: Enzymatic). Moreover, they are expected to have interesting antioxidant properties when they contain phenolic groups. The alkyl chain should enhance their ability to penetrate into the cellular membrane (Nicolosi, 2002, Journal of Molecular Catalysis B: Enzymatic). The presence of a sugar unit could also be useful to target specific cells. In this study, novel aromatic glycolipids were synthesized as useful models for studying the structure–activity relationship, in particular as regards to their aromatic group.Theireffect on cell viability when an oxidative stress is induced was tested. In parallel, their interaction with cell models (liposomes) was studied through membrane fusion and permeability experiments. [less ▲]

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See detailOsmotic dehydration of pomegranate seeds (PUNICA GRANATUM L.)
Bchir, Brahim ULg; Besbes, Souhail; Attia, Hamadi et al

Poster (2013, May 30)

Osmotic dehydration of pomegranate seeds was carried out at different temperatures (30, 40, 50°C) in a 55°Brix solution of sucrose, glucose, and mixture sucrose & glucose (50:50 wt/wt). The most ... [more ▼]

Osmotic dehydration of pomegranate seeds was carried out at different temperatures (30, 40, 50°C) in a 55°Brix solution of sucrose, glucose, and mixture sucrose & glucose (50:50 wt/wt). The most significant changes of water loss and solids gain took place during the first 20 min of dewatering. During this period, seeds water loss was estimated to 46% in sucrose, 37% in glucose and 41% in mix glucose/sucrose solution. The increase of temperature favoured the increase of water loss, weight reduction, solids gain and effective diffusivity. Differential scanning calorimetry data provided complementary information on the mobility changes of water and solute in osmodehydrated pomegranate seeds. The ratio between % frozen water and % unfreezable water decreased from 5 to 0.5 during the process. That involving the presence of very tightly bound water to the sample, which is very difficult to eliminate with this process. It also appeared that glass transition temperature depends on the types of sugar. [less ▲]

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See detailUne méthode d’implantation de tours pour favoriser leur insertion dans le tissu urbain
Saint-Pierre, Claire ULg; Becue, Vincent; Diab, Youssef et al

Poster (2013, May 30)

La question de la verticalité est récemment revenue parmi les préoccupations et débats d'experts de la ville. Les tours continuent de faire l'objet de controverses mais la volonté de les utiliser comme ... [more ▼]

La question de la verticalité est récemment revenue parmi les préoccupations et débats d'experts de la ville. Les tours continuent de faire l'objet de controverses mais la volonté de les utiliser comme outil de développement urbain durable demeure. En France, le processus décisionnel de la construction des tours est linéaire et prend en considération relativement tard, les critères nécessaires à une bonne qualité d'insertion urbaine. L'article propose une méthode d'implantation de tours plus globale, permettant d'évaluer l'insertion urbaine d'une tour par rapport à son environnement ainsi que d'accompagner les acteurs impliqués dans leur prise de décision. [less ▲]

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