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See detailPossible intracellular effect of the new water-soluble form of curcumin (NDS27) on the oxidant response of stimulated neutrophils
Derochette, Sandrine ULg; Mouithys-Mickalad, Ange ULg; Deby-Dupont, Ginette et al

Poster (2012, April 18)

Neutrophils (PMNs) are involved in host defense against infections through the production of reactive oxygen species (ROS) to kill pathologic agents. But, an excessive ROS production, called “oxidative ... [more ▼]

Neutrophils (PMNs) are involved in host defense against infections through the production of reactive oxygen species (ROS) to kill pathologic agents. But, an excessive ROS production, called “oxidative stress” is associated with tissue damages and development of chronic or acute inflammatory diseases. PMNs are prime therapeutic targets to control inflammatory events associated to ROS production. Nowadays, there is a growing interest for the use of polyphenolic molecules to modulate the inflammatory response. The aim of this work was to study the antioxidant effect of NDS27 (1), a new highly water-soluble form of the polyphenolic molecule curcumin, on in vitro stimulated equine PMNs. NDS27 (10-6 to 10-4 M) was pre-incubated with cells and eliminated before their activation. The ability of NDS27 to enter into the cells was checked by HPLC from the cellular extracts. The intracellular ROS production by phorbol myristate acetate (PMA) stimulated PMNs was measured by fluorescence using 2’,7’-dichlorofluorescin diacetate. Lucigenin dependent chemiluminescence was used to measure extracellular ROS production. Additionally, the effect of NDS27 was tested on the activity of myeloperoxidase (MPO), a hemic enzyme contributing to the oxidant response of neutrophils. The activity of the released MPO by cytochalazine B (CB) and N-formyl-methionyl-leucyl-phenylalanine (fMLP) stimulated PMNs was measured by SIEFED (“Specific Immunologic Extraction Followed by Enzymatic Detection”) (2). The HPLC results showed that NDS27 enters into PMNs and interacts with their membrane. NDS27 significantly and dose-dependently inhibited the ROS production in neutrophils without affecting their viability. Likewise, the activity of MPO released by PMNs was lowered by NDS27. Overall, our findings demonstrate that the membrane of neutrophils is permeable to NDS27 or interacts with the drug, suggesting that its inhibitory effect on ROS production is mainly associated to an intracellular effect probably by acting on the enzymes implied in respiratory burst like NADPH oxidase and MPO. The modulatory effect of NDS27 towards the oxidant activity of cells involved in immune and inflammatory response open therapeutic perspectives to control equine or human pathologies with excessive inflammatory reactions. 1. Neven et al. 2011, Patent Application Publication: US2011/0257126 A1 2. Serteyn et al. 2005, European Patent Specification : EP1711817 B1 [less ▲]

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See detailPsychrotrophic and psychrophylic Clostridium responsible for meat spoilage
Rodrigues, A.; Taminiau, Bernard ULg; Daube, Georges ULg

Poster (2012, April 18)

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See detailA sustainable method inspired by nature for the production of original bi-functional nutraceuticals containing prebiotic fibers and highly bio-available forms of calcium and magnesium
Goffin, Dorothée ULg; Blecker, Christophe ULg; Paquot, Michel ULg

Poster (2012, April 18)

A sustainable method inspired by nature is proposed leading to an original bifunctional product active on gut health, metabolism regulation, immunity and mineral fortification, fighting against topical ... [more ▼]

A sustainable method inspired by nature is proposed leading to an original bifunctional product active on gut health, metabolism regulation, immunity and mineral fortification, fighting against topical chronic diseases (type2 diabetes, osteoporosis, colon cancer…). [less ▲]

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See detailInfluence of protein context on the propensity of polyglutamine tracts to induce protein aggregation into amyloid fibrils
Huynen, Céline ULg

Poster (2012, April 18)

Nine neurodegenerative diseases, referred to as polyglutamine diseases, are associated with nine proteins containing an expanded polyglutamine (polyQ) tract. PolyQ tracts are encoded by a repetition of ... [more ▼]

Nine neurodegenerative diseases, referred to as polyglutamine diseases, are associated with nine proteins containing an expanded polyglutamine (polyQ) tract. PolyQ tracts are encoded by a repetition of the CAG codon in the corresponding genes, and are present in proteins of healthy people. They are however pathogenic when their length, due to mutations, becomes higher than a threshold generally comprised between 35 and 45Q. Such pathogenic tracts trigger the aggregation of the proteins into amyloid-like aggregates that could play an important role in the disease. It is therefore necessary to investigate at a molecular level the aggregation process of polyQ proteins. Since proteins associated with polyQ diseases are generally big and relatively insoluble, they are difficult to produce and manipulate. We have therefore decided to study the aggregating properties of polyQ proteins by designing and characterizing model proteins made of a well-characterized host protein, the β-lactamase BlaP, and polyQ tracts of different lengths (23 to 79Q) inserted at position 197 of BlaP. The aggregating properties of these BlaP chimeras recapitulate those of proteins associated with polyQ diseases. We indeed observed that there is a minimal number of glutamines (threshold) required for chimeras aggregation into amyloid-like fibrils and that the kinetics of aggregation are faster with longer glutamine repeats. Most importantly, the value of the threshold for amyloid-like fibril formation seems to critically depend on the structural integrity of BlaP and thus on the constraints applied to the polyQ tract. In the present work, we investigate more deeply the role of the protein context and the role of oligomers in the process of aggregation of BlaP chimeras. This study is mainly based on the use of two techniques: the quartz crystal microbalance with dissipation (QCM-D) in combination with atomic force microscopy (AFM), and the dynamic light scattering (DLS). Preliminary QCM-D results indicate that in native condition there is a minimal number of glutamines required for the elongation of BlaP197(Gln)79 fibrils by BlaP chimeras. This threshold is different to that observed for the aggregation monitored in solution in absence of seed. Most interestingly it corresponds to the threshold observed in denaturing conditions. These observations suggest that the conformation of BlaP is the limiting step for amyloid fibril formation by interfering with the nucleation step. Preliminary DLS experiments indicate that the oligomers formed by BlaP197(Gln)79 in native condition are on the pathway of amyloid fibril formation and could act as aggregation nuclei. [less ▲]

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See detailOptimization of recombinant root-secreted IgGs production in Arabidopsis thaliana by screening cell wall mutants
Boulanger, Benoit ULg; Périlleux, Claire ULg; Tocquin, Pierre ULg

Poster (2012, April 18)

The production of complex heterologous proteins (e.g. monoclonal antibodies, mAbs) in plants has several advantages animal based systems such as low cost, scalability and limited risk of contamination by ... [more ▼]

The production of complex heterologous proteins (e.g. monoclonal antibodies, mAbs) in plants has several advantages animal based systems such as low cost, scalability and limited risk of contamination by human pathogens. mAbs are glycoproteins that require to be targeted to the plant secretory pathway in order to be properly folded and matured. They are ultimately delivered in the cell wall and are expected to be freely released in the extracellular space and the external medium, which would greatly simplify downstream processing. However, a significant part of plant produced and secreted mAbs remains bound to the cell wall, therefore hindering recovery. In this study, we evaluated the extra-cellular release of root-secreted proteins of wild-type plants and cell wall mutants of Arabidopsis thaliana. Recovered protein were either analyzed by SDS-PAGE for full proteome profiling or by gelatin zymography to reveal the activity of cell wall-bound proteases. The production, secretion and release of recombinant IgG will be eventually studied in transgenic hairy-roots generated from selected mutants. [less ▲]

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See detailSynthesis and evaluation of boronic acids as inhibitors of Penicillin Binding Proteins of classes A, B and C
Zervosen, Astrid ULg; Sauvage, Eric ULg; Bouillez, André ULg et al

Poster (2012, April 18)

The widespread use of beta-lactam antibiotics has lead to the worldwide appearance of drug-resistant strains. Bacteria have developed resistance to beta-lactams by three main mechanisms: the production of ... [more ▼]

The widespread use of beta-lactam antibiotics has lead to the worldwide appearance of drug-resistant strains. Bacteria have developed resistance to beta-lactams by three main mechanisms: the production of beta-lactamases that catalyze hydrolysis of beta-lactams, the production of low-affinity, drug resistant Penicillin Binding Proteins (PBPs) and the over expression of resistant PBPs. PBPs are interesting targets because they catalyse the last steps of the biosynthesis of peptidoglycan, which is unique in bacteria and has no mammalian analogs, outside the cytoplasmic membrane. Various non-ß-lactam inhibitors of PBPs have been developed with the objective of attempting to stall the development of ß-lactam resistance. Boronic acids are potent beta-lactamase inhibitors and have been shown to display some specificity for soluble transpeptidases and PBPs, but their potential as inhibitors of the latter enzymes is yet to be widely explored. Recently, a (2, 6-dimethoxybenzamido)methylboronic acid was identified as being a potent inhibitor of Actinomadura sp. R39 transpeptidase (IC50: 1.3 µM). Here, we will discuss the synthesis of a number of acylaminomethylboronic acids, analogs of (2, 6-dimethoxybenzamido)methylboronic acid, and their potential as inhibitors of PBPs. Several boronic acids of this library were able to inhibit PBPs of classes A, B and C from penicillin sensitive strains. Thus (2-nitrobenzamido)methylboronic acid was identified as a good inhibitor of class A PBP (PBP1b from S. pneumoniae, IC50 = 26 µM), class B PBP (PBP2xR6 from S. pneumoniae, IC50 = 138 µM) and class C PBP (R39 from Actinomadura sp., IC50 = 0.6 µM). Crystal structures of complexes of R39 and PBP1b with boronic acid analogs of our library have already been solved and allowed an interpretation of results. We believe that this work opens new avenues towards the development of molecules that will inhibit PBPs, and eventually display bactericidal effect, on distinct bacterial species. [less ▲]

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See detailMolecular biomimetics applied to medical devices
Van de Weerdt, Cécile ULg; Vreuls, Christelle ULg; Genin, Alexis ULg et al

Poster (2012, April 18)

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See detailOptimisation of new biodegradable microcarriers tailored for tissue engineering
Demina, T; Akopova, T; Tsoy, A et al

Poster (2012, April 18)

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See detailNeuropeptides and endogenous opioids expression during silent chronic inflammation
Chavarria Bolanos, D; de Jesus Pozos Guillén, A; Grandfils, Christian ULg et al

Poster (2012, April 18)

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See detailInnovative multilayered nanofibers for wound dressing application
Croisier, Florence ULg; Detrembleur, Christophe ULg; Jérôme, Christine ULg

Poster (2012, April 18)

Chitosan is a natural polymer derived from the chitin of crustacean or mushroom shells, that intrinsically presents haemostatic, mucoadhesive, antimicrobial and immunostimulant properties. This ... [more ▼]

Chitosan is a natural polymer derived from the chitin of crustacean or mushroom shells, that intrinsically presents haemostatic, mucoadhesive, antimicrobial and immunostimulant properties. This polysaccharide has shown a great potential for biomedical and pharmaceutical applications, on account of its remarkable compatibility with physiological medium. Besides, it is degraded in a physiological environment into non-toxic products, which make chitosan an outstanding candidate for short- to medium-term applications. In this respect, nanometric fibers are highly interesting as their assembly mimics the skin extracellular matrix structure. Such nanofibrous materials can be prepared by electrospinning (ESP). This technique uses a high voltage to create an electrically charged jet of polymer solution or melt which leads to fibers formation. Depending on the polymer characteristics (a.o. molecular weight, solution viscosity and conductivity) and processing conditions (electric potential, distance between syringe-capillary and collection plate, concentration, flow rate), polymer fibers ranging from nanometers to a few microns in diameter can be obtained and subsequently used as potential scaffolds, a.o. to form a temporary, artificial extracellular matrix. In the present study, electrospinning technique was combined with layer-by-layer deposition method (LBL) - a well-known method for surface coating, based on electrostatic interactions - in order to prepare multilayered chitosan-based nanofibers. The antibacterial properties of the obtained material were then assessed, and the presence of a multilayered deposit was confirmed by several techniques. (Future) possibilities for valorization: These multilayered chitosan-based nanofibers present great prospects for the preparation of new biomedical scaffolds - such as wound dressings that could improve skin regeneration. [less ▲]

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See detailDegradation of recombinant IgG by root-secreted proteases of Arabidopsis thaliana and Nicotiana tabacum
Désiron, Carole ULg; Lallemand, Jérôme ULg; Périlleux, Claire ULg et al

Poster (2012, April 18)

Plants are promising hosts for the production of complex recombinant pharmaceuticals, such as antibodies (mAbs), because they offer an inexpensive and safer alternative to traditional production systems ... [more ▼]

Plants are promising hosts for the production of complex recombinant pharmaceuticals, such as antibodies (mAbs), because they offer an inexpensive and safer alternative to traditional production systems. The plant-based production of mAbs, which are multimeric glycoproteins, require their targeting to the secretory pathaway where they are properly folded and matured. However, co-secretion of endogenous proteases, which can represent up to 10% of the extracellular proteins (secretome), is known to significantly alter the yield and quality of secreted mAbs. In this study, we analyzed the proteolytic activities in root-secretome of Arabidopsis thaliana and Nicotiana tabacum. Root-secretomes were recovered by salt extraction and the protease activity was assayed in vitro or by zymography, in a range of pH. The relative contribution of protease classes was evaluated with specific inhibitors. [less ▲]

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See detailNew Advances for In Situ Protein Identification by MALDI In-Source Decay FTMS Imaging
Calligaris, David ULg; Zimmerman, Tyler ULg; Debois, Delphine ULg et al

Poster (2012, April 18)

MALDI imaging mass spectrometry has proven to be effective for the discovery and the monitoring of disease-related proteins. With this technique a molecular analysis could be performed directly from ... [more ▼]

MALDI imaging mass spectrometry has proven to be effective for the discovery and the monitoring of disease-related proteins. With this technique a molecular analysis could be performed directly from tissue sections in the region of the diseased area. The use of in-source decay (ISD), allowing fast and reliable sequences assignments of proteins termini, has proven to be a crucial tool for proteins identification in solution and tissue slices. However, it is necessary to develop additional tools that allow unambiguous assignment of proteins sequences in complex tissue slices. The development of bioinformatic tools and the use of ultra-high mass resolution and high mass accuracy of Fourier transform ion-cyclotron (FTICR) mass spectrometry are ideal for this purpose. In this study, we show that FTICR mass spectrometry combined with data filtering with a software that subtracts matrix peaks aid protein identification. All measurements were carried out on a SolariX FTMS (9.4 Tesla) equipped with a Dual Source with a smartbeamTMII laser (Bruker Daltonics). Mouse brain tissue slices of 14 µm thickness were rinsed to obtain optimal sensitivity and high-quality ions. Before matrix application, a spot of myelin was deposited near mouse brain. 1,5-Diaminionaphtalene was sprayed using an ImagePrep (Bruker Daltonics). Results were interpreted using BioToolsTM 3.2 in combination with MascotTM (Matrix Science) for ISD spectra and FlexImagingTM 3.0 for MALDI-ISD imaging experiments. Matrix peaks were subtracted using an in-house written Java code that sequentially scans all peak lists from acquired spectra against the DAN mass list. Then, another Java code allows to create 2D ion images at selected m/z ratios. The studies were carried out by MALDI-ISD imaging to create interest on FTICR mass spectrometer for proteins identification in the field of biomarkers characterization. It is demonstrated that protein ISD leads to the same pattern of fragmentation observed during MALDI-TOF analyzes. Fragmentation generates cn- and zn-series ions of myelin in presence of DAN. The internal calibration of all the data provides a mass accuracy neighboring 2.5 ppm over the m/z range of interest (300-2500 Da) and a mass resolution of 70000 at m/z 400 Da. It allows the assignment of ISD fragments of proteins in the low mass range (m/z between 300 and 900) that is unambiguously validated by the “ISD signal” recorded from the spots of pure protein solution (myelin) near tissue slice. Moreover, the use of our software “cleans” MS imaging data by reducing/eliminating MALDI matrix peaks that are isobaric to an analyte peak. Novel aspect This study evidences the main input of FTICR mass spectrometer for pathologies diagnosis based on biomarkers localization and identification by MALDI-ISD imaging. [less ▲]

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See detailHemocompatibility of nanocarriers designed to transport biopharmaceutical drugs
Sevrin, Chantal ULg; Cerda, Bernardino; Lombart, François ULg et al

Poster (2012, April 18)

The optimization of nanoparticles (NP) for drug delivery, in particular to target the BBB, imposes to verify their hemocompatibility both for toxicological and efficiency of targeting perspectives. Indeed ... [more ▼]

The optimization of nanoparticles (NP) for drug delivery, in particular to target the BBB, imposes to verify their hemocompatibility both for toxicological and efficiency of targeting perspectives. Indeed the large surface they are able to expose to the biological environment promotes their interaction with various biochemicals, in particular proteins which can after adsorption elicit the activation of biological cascades either responsible from NP clearance or/and harmful body reaction (inflammatory / coagulation). In the frame of the European Integrated Project : “Nanobiopharmaceutics”, we have the opportunity to compare the hemoreactivity of about 145 different NP samples differing in core and surface chemistry and classified according to their expected difference in hydrophobicity based on the nature of their core materials. According to this classification, PLGA nanoparticles, polyglycidol-polyethyethylene oxide nanoparticles, polyglycidol thyolated or polyacrylamide nanogels, and polyelectrolyte complexes either based on polyamidoamine or poly(N,N-dimethylamino-2-ethylmethacrylate) have been evaluated within a concentration ranging from 0.3 to 1000 =g/mL. These in vitro tests have been realized for screening purpose adopting normal human bloods and according to Iso 10993. As a summary of this extensive study, our results clearly highlight that most of the polymeric nanoparticles evaluated give rise to some alterations of the blood components. In particular the platelets, intrinsic pathway of coagulation and complement activation are the most reactive biological parameters in the presence of these nanostuctures. Although not strictly related to the surface chemistry our classification has also allowed us to derive some clear correlations between nanomaterial properties and their hemoreactivity. Within the class of polyelectrolyte electrolyte complexes, the modifications brought in the surface chemistry has drastically improved their hemoreactivity. [less ▲]

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See detailInvestigation of nanoparticles as potential activators for the optimization of PAH biodegradation
Masy, Thibaut ULg; Wannoussa, Wissal ULg; Lambert, Stéphanie ULg et al

Poster (2012, April 10)

These last decades, through the industrial development and its imperfect waste management, the contamination by hydrocarbons in water and soils has led to a progressive deterioration of environmental ... [more ▼]

These last decades, through the industrial development and its imperfect waste management, the contamination by hydrocarbons in water and soils has led to a progressive deterioration of environmental quality, which is more and more considered nowadays. Amongst all the existing cleaning-up techniques, the bioremediation appears as the best compromise between treatment costs and effectiveness. However, this bioprocess remains time-consuming, especially for persistent pollutants as PAHs (Polycyclic Aromatic Hydrocarbons). A first way to improve the biodegradation consists in adding a consortium of efficient microorganisms in the polluted area (bioaugmentation). A further way to improve the bioremediation rate is based on the use of nutrients to assist the microbial metabolism (biostimulation). Our project gathers these two methods, specifically for the PAH biodegradation of polluted soils. Firstly, different suitable strains from our lab will be compared together in terms of PAH-degrading rate, in order to select the best microorganisms. As all these strains were selected from a long-term oil-polluted dried soil, they should be able to compete against the endogenous microflora, even if they are injected in the soil in a powdered starter. Secondly, trace elements in the nanoparticulate form, with concentrations of about 10-5M, will be added to catalyze the bacterial metabolism. First results already showed a sharp increase (2 to 3 fold) in the biodegradation kinetics, which is promising for the further scaling-up stages. In addition, this PhD project attempts to understand the mechanism of interaction between bacteria and nanoparticulate catalysts. [less ▲]

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See detailPierres à aiguiser en Gaule Belgique et en Germanie : mise en place d'une typologie et identification des matériaux
Thiebaux, Aurélie ULg; GOEMAERE, Eric; Henrotay, Denis et al

Poster (2012, April 04)

Detailed reference viewed: 36 (5 ULg)
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See detailCALCIUM HYDROXIDE LOADED PLGA MICROSPHERES FOR ENDODONTICS: EFFECT OF FORMULATION METHOD ON Ca++ RELEASE PROFILE
Chavarria Bolanos, Daniel ULg; Cerda-Cristerna, BI; Flores-Reyes, Hector et al

Poster (2012, April 04)

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See detailUnderstanding of the Venus upper atmosphere dynamics with O2(a1 ) Venus Express observations
Soret, Lauriane ULg; Gérard, Jean-Claude ULg; Piccioni, Giuseppe et al

Poster (2012, April)

The O2(a1 ) nightglow emission at 1.27 m may be used as a tracer of the dynamics prevailing in the Venusian upper mesosphere. This emission has thus been observed with ground-based telescopes and from ... [more ▼]

The O2(a1 ) nightglow emission at 1.27 m may be used as a tracer of the dynamics prevailing in the Venusian upper mesosphere. This emission has thus been observed with ground-based telescopes and from space with instruments such as VIRTIS on board Venus Express. Observations have shown that the emission maximum is statistically located close to the antisolar point at 96 km. As originally suggested by Connes et al. (1979), such an emission 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 excited O2(a1 ) molecules. Their radiative deexcitation produces the O2(a1 ) nightglow with a maximum near the antisolar point. However, VIRTIS observations indicate that the O2(a1 ) nightglow emission is highly variable, both in intensity and location. Actually, when considering individual observations, the patch of bright emission is rarely located at the antisolar point and the brighter area around this point is the result of statics accumulation. Also, when considering several individual observations acquired in a short period of time, it is possible to follow an individual emission patch and to deduce its displacement and its brightness variation due to activation or deactivation. In this study, we analyze several sequences of VIRTIS observations in order to understand the Venus upper mesosphere dynamics.We show that the intensity can vary by several megaRayleighs in a couple of hours with effective lifetimes on the order of several hours. The horizontal motion of the spots leads to the conclusion that winds in the 95-100 km region are in the range of 25 to 150 m s-1, in good agreement with the study by Hueso et al. (2008). [less ▲]

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See detailEvaluation of three immunoassays for serodiagnosis of human Mycoplasma pneumoniae infection
HUYNEN, Pascale ULg; TOUSSAINT, Françoise ULg; HAYETTE, Marie-Pierre ULg et al

Poster (2012, April)

The aim of this study was to evaluate three commercial automated immunoassays for the serological diagnosis of M. pneumoniae infection.

Detailed reference viewed: 16 (7 ULg)
See detailInorganic carbon dynamics in coastal arctic sea ice and related air-ice CO2 exchanges
Geilfus, Nicolas-Xavier ULg; Tison, J.-L.; Carnat, G. et al

Poster (2012, April)

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See detailCalcium-induced conformational changes of the elicitor and membrane-active fengycin
Nasir, Mehmet Nail ULg; Lins, Laurence ULg; Ongena, Marc ULg et al

Poster (2012, April)

Fengycin is a natural lipopeptide synthetized by Bacillus subtilis strains. It is characterized by strong antifungal and low hemolytic activities. It seems also play a role in the promoting of elicitor ... [more ▼]

Fengycin is a natural lipopeptide synthetized by Bacillus subtilis strains. It is characterized by strong antifungal and low hemolytic activities. It seems also play a role in the promoting of elicitor activities of other compounds. The target of the biological activities of fengycin is supposed to be plasma membrane of sensitive cells. Even though the natural fengycin from has been discovered 25 years ago, nowadays, there is an increase of interest for this compound because of its potent applications. Until 15 years ago, the primary structure of fengycin was a matter of open debate before the publication of the corrected structure obtained by nuclear magnetic resonance and mass spectroscopy techniques. Although the infrared and ultraviolet absorption spectra of the lipopeptide were measured, no detailed analysis of these data was performed probably because of the unconventional sequence of the lipopeptide making these kinds of analyses complicated. In this work, our attempt was to analyze the conformational properties of fengycin as well as the calcium-induced changes using two complementary spectroscopic methods, Fourrier transformed infrared spectroscopy (FTIR) and circular dichroism (CD). In a first step, we have characterized the conformational properties of pure fengycin. The lipopeptide adopts turn conformation in trifluoroethanol, a membrane-mimicking solvent. D-aminoacids seem to be involved in intra molecular hydrogen bonds. In a second step, we have investigated the role played by Ca2+ ions on the possible conformational changes of fengycin. The addition of calcium gives rise to important modifications of the conformation. As fengycin has two glutamate residues, calcium is supposed to bind to their side chains. In conclusion, we have demonstrated that the conformation of fengycin is closely depending of the environment and the presence of calcium ions play an important role on the conformational changes of the lipopeptide. Moreover, spectra obtained both FTIR and CD methods ascertain the presence of turn conformation. [less ▲]

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See detailTimbre description of the sound of air-treatment systems for predicting acoustic confort
Minard, Antoine; Billon, Alexis ULg; Goujard, B. et al

Poster (2012, April)

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See detailThe Venus nitric oxide nightglow vertical distribution : update, new features and modelling
Stiepen, Arnaud ULg; Gérard, Jean-Claude ULg; Soret, Lauriane ULg et al

Poster (2012, April)

Ultraviolet (UV) spectra of the delta (190-240 nm) and gamma (225-270 nm) bands of the nitric oxide (NO) molecule have been measured in the atmosphere of the Venus night side with the Spectroscopy for ... [more ▼]

Ultraviolet (UV) spectra of the delta (190-240 nm) and gamma (225-270 nm) bands of the nitric oxide (NO) molecule have been measured in the atmosphere of the Venus night side with the Spectroscopy for Investigation of Characteristics of the Atmosphere of Venus (SPICAV) instrument on board Venus Express (VEX). Excited NO molecules on the night side of the planet find their source in the radiative recombinaison of O(3P) and N(4S) atoms produced on the dayside by Extreme Ultraviolet (EUV) solar photons that cause photodissociation of CO2 and N2 molecules. We analyse with an improved statistics the behaviour of the vertical emission profile of the NO nightglow. We also present a method used to retrieve and analyse the volume emission rate. We describe the dependence of the vertical distribution with latitude and local time and its variability. New features in the vertical distribution of the NO emission such as double peaks are also exhibited. Furthermore, we use a one-dimensional chemical-diffusive model to compare the major features of the calculated O2 1.27 microm and NO UV emissions profiles with those observed with SPICAV. [less ▲]

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See detailEngineering geological mapping in Wallonia (Belgium) : present state and recent computerized approach
Delvoie, Simon ULg; Radu, Jean-Pol ULg; Ruthy, Ingrid ULg et al

Poster (2012, April)

An engineering geological map can be defined as a geological map with a generalized representation of all the components of a geological environment which are strongly required for spatial planning ... [more ▼]

An engineering geological map can be defined as a geological map with a generalized representation of all the components of a geological environment which are strongly required for spatial planning, design, construction and maintenance of civil engineering buildings. In Wallonia (Belgium) 24 engineering geological maps have been developed between the 70s and the 90s at 1/5,000 or 1/10,000 scale covering some areas of the most industrialized and urbanized cities (Liège, Charleroi and Mons). They were based on soil and subsoil data point (boring, drilling, penetration test, geophysical test, outcrop. . . ). Some displayed data present the depth (with isoheights) or the thickness (with isopachs) of the different subsoil layers up to about 50 m depth. Information about geomechanical properties of each subsoil layer,useful for engineers and urban planners, is also synthesized. However, these maps were built up only on paper and progressively needed to be updated with new soil and subsoil data. The Public Service of Wallonia and the University of Liège have recently initiated a study to evaluate the feasibility to develop engineering geological mapping with a computerized approach. Numerous and various data (about soil and subsoil) are stored into a georelational database (the geotechnical database – using Access, Microsoft®). All the data are geographically referenced. The database is linked to a GIS project (using ArcGIS, ESRI®). Both the database and GIS project consist of a powerful tool for spatial data management and analysis. This approach involves a methodology using interpolation methods to update the previous maps and to extent the coverage to new areas. The location (x, y, z) of each subsoil layer is then computed from data point. The geomechanical data of these layers are synthesized in an explanatory booklet joined to maps. [less ▲]

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See detailMicroRNA-146a is a causative factor and a specific biomarker for peripartum cardiomyopathy
Halkein, Julie ULg; Tabruyn, Sébastien ULg; Haghikia, Arash et al

Poster (2012, April)

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See detailExpansion of the main auroral oval at Jupiter : evidence for Io’s control over the Jovian magnetosphere
Bonfond, Bertrand ULg; Grodent, Denis ULg; Gérard, Jean-Claude ULg et al

Poster (2012, April)

In spring 2007, New Horizons' Jupiter fly-by provided a unique opportunity for the largest observation campaign dedicated to the Jovian aurora ever carried out by the Hubble Space Telescope. UV images of ... [more ▼]

In spring 2007, New Horizons' Jupiter fly-by provided a unique opportunity for the largest observation campaign dedicated to the Jovian aurora ever carried out by the Hubble Space Telescope. UV images of the aurora have been acquired on a quasi-daily basis from mid-February to mid-June 2007. Polar projection of the auroral emissions clearly show a continuous long-term expansion of main oval additionally to day by day variations. The main oval moved so much that the Ganymede footprint, which is usually located equatorward of the main emissions, has even been observed inside of it. Simultaneously, the occurrence rate of large equatorward isolated auroral features increased over the season. These emission patches are generally attributed to injections of depleted flux tubes. On 6th June, one of these features exceptionally moved down to the Io footpath. The Io footprint seemed to disappear while the footprint moved through this patch of emission. This disappearance is a unique case among all the UV images of the aurora acquired during the last 12 years. We suggest that all these changes seen in the Jovian aurora are evidence for a major reconfiguration of the magnetosphere induced by increased volcanic activity on Io. Indeed, New Horizons observed particularly intense activity from the Tvashtar volcano in late February 2007. Moreover, sodium cloud brightening caused by volcanic outbursts have also been seen in late May 2007. According to our interpretation, repeated volcanic outbursts beefed up the plasma torus density and its mass outflow rate. This caused the corotation breakdown boundary to migrate closer to Jupiter. Consequently, the main auroral oval moved equatorward. As heavy flux tubes move outward, sparsely filled ones should be injected into the inner magnetosphere in order to conserve the magnetic flux in this region. This phenomenon could explain the large number of injection signatures observed in May-June 2007. Such a cloud of depleted flux tubes probably disrupted the Io-magnetosphere interaction, leading to an abnormally faint Io footprint. [less ▲]

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See detailAllergenic properties of the house dust mite protease Der p 3
Bouaziz, Ahlem ULg

Poster (2012, April)

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See detailMapping error due to image geometric correction.
Hallot, Eric ULg; Cornet, Yves ULg; Hallot, Pierre ULg

Poster (2012, April)

Nowadays, image processing and GIS tools are more accessible and available to all. Most of diachronical or historical studies use the image geometric correction with several documents like old maps, plans ... [more ▼]

Nowadays, image processing and GIS tools are more accessible and available to all. Most of diachronical or historical studies use the image geometric correction with several documents like old maps, plans or aerial photographs. They are usually based on low-order polynomial equation to perfom these kinds of simplistic uses. Most of commercial softwares provide us a total or by ground control points RMSE but they don’t offer a overview of the spatial error distribution. More this does not guarantee that its significance for the other points of the image. Do not consider these errors can lead to erroneous observations and misinterpretations like historical moving streams or bank erosion rate. Using a least square adjustment (LSA), allow to recalculate the transformation equation from the pairs of control points coordinates. Assuming that residuals are spatially auto-correlated, we can build error vectors whose direction and magnitude symbolize the error at each point of the image. By another way, LSA manage the precision during transformation process by using a stochastic model in addition of the mathematical model during the transformation. This gives us variance on parameters of the transformation. Knowing the precision of all elements and variance/covariance matrix on transformation parameters, we apply variance propagation on the model. As an output, we obtain confidence ellipses on each transformed points, thus a spatial distribution of error for the entire image. Moreover, this leads us to determine statistically if observed movement are significant or not. The represent error is a complex problem that cannot be solved with a quick fix. In this work, we present an interesting example of using well-known topographic methods to solve image processing problems. [less ▲]

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See detailStudy of the microbial diversity in vacuum-packed chilled beef from different origins through a metagenomics approach
Didimo Imazaki, Pedro Henrique ULg; Taminiau, Bernard ULg; Nezer, Carine et al

Poster (2012, April)

Despite a diverse initial microbial population, bacterial spoilage of vacuum-packed chilled beef is mainly due to the growth of psychrotrophic bacteria. The study of the microflora of vacuum-packed ... [more ▼]

Despite a diverse initial microbial population, bacterial spoilage of vacuum-packed chilled beef is mainly due to the growth of psychrotrophic bacteria. The study of the microflora of vacuum-packed chilled beef remains a challenge since some members of the microflora may be missed or not identified by cultivation-based methods. The aim of this study was to evaluate the microbial diversity in eight batches of vacuum-packed chilled beef from different origins (Australia, Belgium, Brazil, Ireland and United Kingdom) by metagenomics. Longissimus dorsi muscle samples were homogenized and analysed in early and late stages of their shelf life by metagenomics. The metagenomic assays consisted in DNA extraction, 16S ribosomal RNA gene amplification, pyrosequencing and data analysis. All samples, except for two batches from Australia, presented a high microbial diversity in the beginning of their shelf life. Enterobacteriaceae, Pseudomonas, Burkholderia, Lactobacillus and Sterotrophomonas were some of the major bacteria identified at this stage of storage. The dominant flora (> 80 % of relative abundance) in two Australian batches was composed by Carnobacterium. At the end of the shelf life of the samples, a decrease in microbial diversity was observed in almost all batches. At this stage of storage, Carnobacterium, Lactobacillus, Lactococcus and Enterococcus were some of the major genera identified. Carnobacterium remained the dominant flora in the two Australian batches cited above, which could explain the long shelf life applicable to this meat (140 days) as some Carnobacterium strains induce a biopreservative effect especially by producing bacteriocins with a wide inhibition spectrum. Metagenomics showed to be a very useful tool to study the microbial population of a complex matrix such as meat since some of the identified genera such as Lactobacillus and Carnobacterium are known not to grow or to grow slowly in media commonly used for the isolation and cultivation of total viable counts. [less ▲]

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See detailhe influence of transformational leadership on commitment: New underlying processes
Marique, Géraldine; Stinglhamber, Florence; Hanin, Dorothée et al

Poster (2012, April)

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See detailOrganizational identification and commitment: The impact of POS and prestige
Marique, Géraldine; Stinglhamber, Florence; Desmette, Donatienne et al

Poster (2012, April)

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See detailMagnetic hybrid materials for triggered drug delivery and optical properties of intraocular lens
Liu, Ji ULg; Hurtgen, Marie ULg; Mornet, Stephan et al

Poster (2012, March 30)

Stimuli-responsive nano-materials have been playing increasingly important roles in the biomedical field due to their ability to alter the physico-chemical properties in response to external stimuli, such ... [more ▼]

Stimuli-responsive nano-materials have been playing increasingly important roles in the biomedical field due to their ability to alter the physico-chemical properties in response to external stimuli, such as temperature, pH, ionic strength, magnetic field, etc. Nanohybrids bearing an inorganic core and thermo-responsive polymer shell are particularly applicable in target delivery and controlled drug release. Poly (N-vinylcaprolactam) (PNVCL) and its copolymers, exhibiting lower critical solution temperature (LCST) where the transition between hydrophilic and hydrophobic state happens, is one of the optimal choices for this core/shell structure. Here we present the in-situ fabrication of thermo-responsive gold nanohybrids coated with a novel poly (vinyl alcohol)-b-poly (N-vinylcaprolactam) (PVOH-b-PNVCL) block copolymers, which were prepared by the cobalt-mediated radical polymerization (CMRP). The interaction between both PVOH and PNVCL segments and gold nanoparticles was confirmed by FT-IR spectra. A sharp thermo-induced phase transition with a good reversibility upon change in temperature was detected by DLS and UV/vis spectrometer. Furthermore, the presence of hydrophilic PVOH moieties endows the gold nanohybrids with improved colloidal stability above LCST without any flocculation detected. This kind of gold nanohybrids can be envisaged as a new drug delivery vehicle. [less ▲]

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See detailDisulfide bond scrambling in partially reduced and alkylated peptides revealed by Ion Mobility Mass Spectrometry
Echterbille, Julien ULg; Quinton, Loïc ULg; De Pauw, Edwin ULg

Poster (2012, March 29)

Animal venoms are mainly composed of peptide toxins, which are highly structured by many disulfide bridges. In these toxins, disulfides play different major roles such as increasing the toxins efficiency ... [more ▼]

Animal venoms are mainly composed of peptide toxins, which are highly structured by many disulfide bridges. In these toxins, disulfides play different major roles such as increasing the toxins efficiency by lowering their immunogenicity or providing the adequate conformation to efficiently bind to the biological receptor. Peptide sequencing followed by determination of the cysteine pairings is still challenging and, therefore, an important step in structural analysis. This work was, in its beginning, focused on the development of ion mobility (IMS) based methodology used to assign disulfides. The strategy relies on the analysis of partially reduced/alkylated disulfide containing peptides. The resulting mixture is analyzed by ion mobility, followed by MS/MS acquisition on each mobility resolved species. Surprisingly, first investigations revealed, after partial reduction, a disulfide rearrangement phenomenon. Indeed, some of the cystein pairings were not those expected to be. These experiments were conducted on ¿-CnI and ¿-GI toxins purified from the venoms of Conus consors and Conus geographus marine snails, respectively. Each toxin contains four cysteines linked together with two disulfide bridges. Peptides were partially reduced by an excess of dithiothreitol and then alkylated by a large excess of iodoacetamide. The resulting mixture was purified on a microcolumn before being analyzed by nanoESI-Synapt-G2. Fragmentation was performed after the mobility cell, to obtain specific fragments of each species. Each toxin partially reduced/alkylated results, theoretically, in a mixture of fully oxidized (two disulfides oxidized), fully reduced (two disulfides reduced) and partially reduced forms (one of the two disulfides reduced). Thanks to the mass shift created by the alkylation, an isolation of the species which m/z ratio corresponds to one disulfide reduced and alkylated has been done in the quadrupole before the mobility separation. The arrival time distribution of triply charged ions reveals the presence of different species (4 in the case of ¿-GI and 2 for ¿-CnI), characterized by different relative cross sections in the gas-phase. As ion mobility resolved species give characteristic fragments upon fragmentation (after IMS), we were able to identify a scrambling of the disulfides (isomerization). In simple words, other disulfide bonds than expected ones were characterized. We suppose that the scrambling phenomenon occurs in solution,during the reduction step, since the alkylation cannot avoid rearrangement. The method is now being applied to more complex systems containing 3 or 4 disulfide bridges. The influence of the charge state on the mobility separation is systematically analyzed in terms of structural implications. [less ▲]

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See detail1D many-body quantum transport of Bose-Einstein condensates : a truncated Wigner approach
Dujardin, Julien ULg; Argüelles Parra, Arturo ULg; Schlagheck, Peter ULg

Poster (2012, March 29)

We calculate the transport properties of an ultracold gas of Bose- Einstein condensed atoms that is coupled from a magnetic trap into a one-dimensional waveguide. A central aim of such guided atom lasers ... [more ▼]

We calculate the transport properties of an ultracold gas of Bose- Einstein condensed atoms that is coupled from a magnetic trap into a one-dimensional waveguide. A central aim of such guided atom lasers is to study the role of atom-atom interaction in many-body transport processes across finite scattering regions within the waveguide resembling tunnel junctions and quantum dots. Our numerical approach to solve this many-body scattering problem is based on a home-made theory where the boundaries of the system are simulating an open system enabling us to calulate observable in the steady-state regime such as density, current, transmission. The results are compared to the mean-field regime. [less ▲]

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See detailAbundance estimates of southern right whales (Eubalaena australis) in Bahía San Antonio, Patagonia, Argentina
Vermeulen, Els ULg; Cammareri, Alejandro

Poster (2012, March 27)

Aerial surveys were conducted to estimate the abundance of southern right whales in Bahía San Antonio, a bay located in the north-western region of the San Matías Gulf (40°50¿S 64°50¿W), Rio Negro ... [more ▼]

Aerial surveys were conducted to estimate the abundance of southern right whales in Bahía San Antonio, a bay located in the north-western region of the San Matías Gulf (40°50¿S 64°50¿W), Rio Negro, Patagonia Argentina. The transect for the realization of aerial surveys was designed using the program DISTANCE 6.0 and consisted out of 14 North-South (up to S 40.9°) parallel transect lines with a 2.5km separation, covering a total surface of 418km² (mean coverage probability=0.78). Transect length was chosen according to the safety restrictions of the pilot. Surveys were conducted in good weather conditions and calm sea state (Beaufort 3 or less) using a high-wing Cessna 152 with a flat window. Due to the small size of the aircraft, only one person could fly besides the pilot; observations where therefore made from one side only. Average speed and height of the aircraft was kept constant over the surveys at 90kn (166km/h) and 700ft (213m) respectively. When a group of southern right whales was sighted, data were taken on location (using a Garmin GPSmap 60csx), time and group size. The downward angle to the group perpendicular to the aircraft¿s track was then measured using a hand-held clinometer (Suunto PM5/360PC). Perpendicular distances were calculated by the means of trigonometry using the aircraft¿s altitude and the declination angle to the sighting. Due the flat windows of the aircraft a left truncation distance was set at 150m. Perpendicular distances were also right-truncated at 10% of the observations. The uniform cosine model was chosen in the view of the minimum AIC to model the detection function of southern right whales in the study area. The estimates of g(0)=(s+t)/(s+d) resulted in a correction factor of 0.392 ± 0.456 In total, 7 aerial surveys were conducted in the beginning of August and September 2009, September, October and November 2010, and August, September 2011, resulting in a total flight time effort of 12.4h. In total, 200 whales were seen in 119 whale groups, equally distributed over the entire bay. Group sizes ranged between 1-5 animals with a mean group size of 1.7 animals (SD=0.83). Results show a peak of averagely 136 ± 63 whales in the bay during the month of September, with less than half the amount of whales present in adjacent months. September being the peak month for right whale presence accords to data from other regions in the country. The aerial surveys resulted in the first estimates of southern right whale abundance in this north Patagonian bay and indicate a marked peak during September. Nevertheless, data obtained over the other months remain scarce. More aerial surveys should be conducted to accurately determine the evolution of southern right whale abundance in the study area. [less ▲]

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See detailAdsorption kinetics of total proteose peptone fractions at the air-water and n-dodecane-water interface
Karamoko, Gaoussou ULg; Razafindralambo, Hary ULg; Danthine, Sabine ULg et al

Poster (2012, March 26)

Surface properties of whey proteins are essential in applications requiring oil emulsification in an aqueous phase, or foam structure formation [1]. The adsorption at interfaces constitutes then an ... [more ▼]

Surface properties of whey proteins are essential in applications requiring oil emulsification in an aqueous phase, or foam structure formation [1]. The adsorption at interfaces constitutes then an approach of the physico-chemical mechanisms of foaming and emulsifying properties. Proteose-peptone is the minor fraction of whey's protein, thermoresistant and acid-soluble protein fraction extracted from milk [2], and known for its interesting surface properties [3]. In this study, the TPP fractions were extracted from skimmed milk UHT (milk TPP) and whey protein concentrate (WPC TPP). Their adsorption kinetics at the air-water and n-dodecane-water interfaces was investigated by the drop volume tensiometer method. Protein solutions of 1% (w/v) were <br />characterized under dynamic condition at various pH (4.0; native pH 4.67- 4.70 and 7.0). Milk TPP showed the lowest values as well as a faster reduction in surface tension at both considered interfaces. Therefore, TPP were found to e effective as surfactants. These results let us to presage good emulsifying and foaming properties of milk TPP compared to WPC TPP. The considerable influence of pH and extraction source on proteose-peptone's interfacial property have been highlighted. [less ▲]

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See detailMicrostructure characterisation of nanocomposite polymeric foams by X-ray microtomography
Plougonven, Erwan ULg; Detrembleur, Christophe ULg; Tran, Minh Phuong ULg et al

Poster (2012, March 26)

Recent advances in microstructured materials have given rise to many new types of composites that exhibit original and interesting physical properties. For example, a nanocomposite made of carbon ... [more ▼]

Recent advances in microstructured materials have given rise to many new types of composites that exhibit original and interesting physical properties. For example, a nanocomposite made of carbon nanotubes inside a polymer matrix shows exceptional electromagnetic interference shielding effectiveness when foamed. However, the effective properties of such materials strongly depend on the shape and topology of the microstructural cells. An accurate method for investigating the cellular microstructure is X-ray microtomography (XRμT), for it is non-destructive, and it provides 3D geometric information. Although it cannot be used to observe nanofiller dispersion, it has a strong potential for cell structure characterisation. In order to reduce the need for trial and error in tailoring these materials, our objective is to quantify, using XRμT, cellular microstructure, for two different types of foaming procedures, namely supercritical CO2 batch foaming and freeze drying, to be able to establish a link between the structure and its shielding effectiveness. The main difficulty stems from the type of material being studied: it is light, therefore hardly absorbs X-rays, cell size is small compared to the resolution capacity of the tomograph, and cell wall thickness is extremely thin in some cases, making them very hard to discern in the images. For these reasons, common image analysis tools for identifying and delimiting objects in an image prove impractical. We propose an original method that uses the 3D autocorrelation function of the tomograms to determine statistical information from these images, such as average cell size and anisotropy, without the need to binarise and segment the images. [less ▲]

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See detailWATER-BORNE EMERGING ZOONOSE? CASE REPORT ON ERYSIPELAS (ERYSIPELOTHRIX RHUSIOPATHIAE) IN HARBOUR PORPOISES (PHOCOENA PHOCOENA) AND HARBOUR SEAL (PHOCA VITULINA).
Boseret, Géraldine ULg; Saegerman, Claude ULg; Mainil, Jacques ULg et al

Poster (2012, March 26)

An adult female harbour porpoise (Phocoena phocoena) and a juvenile male harbour seal (Phoca vitulina) have been found stranded dead on the Belgian coast in late 2001. As the two bodies were in good ... [more ▼]

An adult female harbour porpoise (Phocoena phocoena) and a juvenile male harbour seal (Phoca vitulina) have been found stranded dead on the Belgian coast in late 2001. As the two bodies were in good condition (CC = 2), necropsy and bacteriological analyses were performed as well as other postmortem investigations. Blood heart and organs (liver, digestive and respiratory tract, lungs, spleen, brain, kidneys) samples have been collected and analyzed. The porpoise showed evidence of septicaemia, and the seal presented lesions of acute enteritis. Pure and abundant growth of a small rod-shaped, Gram-labile bacterium was obtained aerobically and anaerobically on Columbia blood agar from heart blood, mouth, pharynx, lungs, intestine and anus of the porpoise, and from intestine, pharynx, mouth, nose and anus of the seal. The colonies were surrounded by a narrow zone of alpha-hemolysis. Catalase- and peroxydase-tests gave negative results. Rapid ID 32 Strepto (Biomérieux, France) sugar tests identified this isolate as Erysipelothrix rhusiopathiae. E. rhusiopathiae could be therefore considered as the cause of septicaemia on the porpoise as it was present in heart blood and internal organs, and could be associated primary or secondary with the enteritis reported on the seal as the bacterium was isolated in pure culture in the digestive tract. E. rhusiopathiae infections have been reported in captive dolphins and sea lions. This zoonotic pathogen is also involved in human local infections, like the “seal finger”, resulting from captive pinnipeds bites. However, it has not been so far described as systemic pathogens of wild cetaceans and pinnipeds. E. rhusiopathiae could be therefore considered as a potentially emergent pathogen which could have important repercussions on human health, particularly veterinarians, marine mammals rescue teams and zoos. [less ▲]

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See detailImpact of the alkyl chain carbon atom number of uronic acid-derivative surfactants on interfacial and colloidal systems
Razafindralambo, Hary ULg; Richard, Gaetan ULg; Laurent, Pascal ULg et al

Poster (2012, March 26)

Uronic acid-derivative surfactants represent today an attractive group of Carbohydrate-based amphiphilic compounds for both fundamental and practical reasons [1,2]. In the continuity of our screening of ... [more ▼]

Uronic acid-derivative surfactants represent today an attractive group of Carbohydrate-based amphiphilic compounds for both fundamental and practical reasons [1,2]. In the continuity of our screening of their basic properties, and the approach in establishing relationships between their structure and properties [3,4], the impact of the alkyl chain carbon atom number on interfacial and colloidal systems has been systematically investigated. In this communication, the effect of odd-even number of carbon atom from C11 to C18, and the particular behavior of long chain derivatives on interfacial properties, as well as their impact on the formation and stability of colloidal systems, are presented. Experimental approaches have been conducted by investigating their properties and behaviors at gas-liquid and liquid-liquid under dynamic, equilibrium, and oscillatory interfacial conditions. Results are completed by and discussed with single molecule models established by theoretical approaches. [1] Razafindralambo, H.;Blecker, C.; Paquot, M., Screening of Basic Properties of Amphiphilic Molecular Structures for Colloidal System Formation and Stability. In Amphiphiles: Molecular Assembly and Applications, American Chemical Society: 2011; Vol. 1070, pp 53-66. [2] Laurent, P.; Razafindralambo, H.; Wathelet, B.; Blecker, C.; Wathelet, J.; Paquot, M., Synthesis and Surface-Active Properties of Uronic Amide Derivatives, Surfactants from Renewable Organic Raw Materials. J. Surfactants Deterg. 2011, 14, 51-63. [3] Razafindralambo, H.; Richel, A.; Wathelet, B.; Blecker, C.; Wathelet, J.; Brasseur, R.; Lins, L.; Miñones, J.; Paquot, M., Monolayer properties of uronic acid bicatenary derivatives at the air-water interface: effect of hydroxyl group stereochemistry evidenced by experimental and computational approaches. Physical chemistry chemical physics: PCCP 2011, 13 15291-15298. [4] Razafindralambo, H.; Blecker, C.; Mezdour, S.; Deroanne, C.; Crowet, J.; Brasseur,R.; Lins, L.; Paquot, M., Impacts of the Carbonyl Group Location of Ester Bond on Interfacial Properties of Sugar-Based Surfactants: Experimental and Computational Evidences. The journal of physical chemistry. B 2009, 113, 8872-8877. [less ▲]

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See detailSeasonal Variation in Abundance and Time-Budget of Bottlenose Dolphins (Tursiops truncatus) in Bahía San Antonio, Patagonia, Argentina
Vermeulen, Els ULg; Cammareri, Alejandro; Holsbeek, Ludo et al

Poster (2012, March 26)

The abundance and time-budget of bottlenose dolphins (Tursiops truncatus) was assessed in Bahía San Antonio, Patagonia (Argentina) in the years 2009 and 2010. A total of 366.4 boat-based survey hours ... [more ▼]

The abundance and time-budget of bottlenose dolphins (Tursiops truncatus) was assessed in Bahía San Antonio, Patagonia (Argentina) in the years 2009 and 2010. A total of 366.4 boat-based survey hours resulted in 64 contact hours with a total of 88 dolphin groups. Mark-recapture abundance estimations, based on 63 identified dolphins, resulted in a corrected maximum estimate of 97 and 83 individuals during winter, and a minimum of 34 and 38 individuals during autumn of 2009 and 2010 respectively. Between 25% and 68% of the population consisted of unidentifiable individuals depending on the season, indicating the high presence of juveniles and calves. Behavioural data indicated that the dolphin¿s time-budget consisted mainly out of resting and feeding, variable over the seasons. Dolphins increased their time feeding and socializing during winter and spring, whereas feeding dropped to a minimum in autumn. During summer, the dolphins spent up to 46% of their time diving, a behaviour presumably associated with a tail out/peduncle-dive foraging strategy. Based on these data, we assume more prey availability during winter and spring (main food source being pelagic fish) and a notable decrease in prey availability during summer with benthic prey species being the main food source. In autumn, even less prey items might be available. Furthermore, the increase in social behaviour during winter and spring combined with a peak in the presence of calves during these seasons, suggests the existence of a mating and calving season. These estimates of abundance are in line with the sizes of other coastal populations of bottlenose dolphins elsewhere in the world, and fit the occupancy patterns described for other coastal areas with small resident communities. The study furthers suggests that dolphins specifically use the study area to rest and feed, and to give birth and raise their young, specifically during winter and spring. [less ▲]

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See detailThe treatment of hypersexuality by cognitive behavioral therapy and virtual therapy
Cismaru, Adina; Andrianne, Robert ULg; Triffaux, Jean-Marc ULg

Poster (2012, March 24)

The sexual addiction is an abnormal sexual practice. It becomes the center of the subject’s existence, by depriving him from other investments and without bringing him real satisfaction. This research ... [more ▼]

The sexual addiction is an abnormal sexual practice. It becomes the center of the subject’s existence, by depriving him from other investments and without bringing him real satisfaction. This research project intends to explore the field of sexual addiction and a possible treatment for it. Several studies on sexual dysfunction treated with psychotherapy and virtual reality have shown that we obtain better results than if we use just the psychotherapy. [less ▲]

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See detailEnvironmental product declarations of mineral paving, a tool for sustainable product choices
Belboom, Sandra ULg; Renzoni, Roberto ULg; Tourneur, Francis ULg et al

Poster (2012, March 22)

This study performs the environmental product declarations for three Belgian mineral products, two granite and one sandstone paving. Both main goals of this work were to obtain Belgian environmental ... [more ▼]

This study performs the environmental product declarations for three Belgian mineral products, two granite and one sandstone paving. Both main goals of this work were to obtain Belgian environmental product declarations to strengthen existing databases and to get similar information for their Asian counterparts. Indeed, competition with China for bluestone products and with India for sandstone pavement is very important due to very competitive prices despite their foreign origin and possibly higher induced environmental impacts. [less ▲]

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See detailEtude IRM par tenseur de diffusion (DTI) des anomalies microstructurelles de la matière blanche dans la maladie de Parkinson
Coolen, Tim; Cremers, Julien ULg; André, Elodie ULg et al

Poster (2012, March 21)

Introduction L’imagerie par résonance magnétique (IRM) conventionnelle du cerveau est réputée normale dans la maladie de Parkinson (MP), mais l’essor récent de techniques avancées offre de nouvelles ... [more ▼]

Introduction L’imagerie par résonance magnétique (IRM) conventionnelle du cerveau est réputée normale dans la maladie de Parkinson (MP), mais l’essor récent de techniques avancées offre de nouvelles perspectives, notamment l’IRM par tenseur de diffusion (DTI). Les études précédentes en la matière, hétérogènes dans leurs méthodes, montrent des résultats discordants. Ici, nous avons utilisé la DTI pour rechercher, sans hypothèse a priori, la présence d’anomalies microstructurelles au sein des principaux tracti de matière blanche dans la MP. Méthodes Soixante et un volumes en pondération de diffusion ont été acquis avec un système Allegra 3T (Siemens, Erlangen, Allemagne) au moyen d’une séquence DTI doublement refocalisée (1) chez 27 patients parkinsoniens non déments (durée moyenne d’évolution après le diagnostic : 5 ± 4.2 ans) et 25 contrôles d’âge (MP: 68,7±8,4; C: 65,1±8,8) et de genre similaires. Pour chaque sujet, les valeurs d’anisotropie fractionnelle (FA) et de diffusivité moyenne (MD) ont été extraites à partir d’un modèle du tenseur obtenu au moyen du logiciel ExploreDTI (2) faisant appel à la méthode RESTORE (3). Nous avons ensuite utilisé le module TBSS (v1.2) du logiciel FSL (4) pour conformer les images des scalaires dans un espace tridimensionnel commun puis rechercher, voxel-par-voxel, des différences entre les 2 groupes au sein du squelette de la matière blanche. Les résultats obtenus à l’issue d’un test par permutations (N=10000) ont été corrigés pour des comparaisons multiples. Résultats L’analyse des cartes de FA montre des valeurs significativement (P<0.05) plus élevées chez les patients dans plusieurs régions (5): fibres sous-corticales péri-rolandiques droites, parties du faisceau arqué droit, fibres du faisceau longitudinal inférieur et /ou fronto-occipital inférieur droit, fibres sous-corticales préfrontales gauches, partie postérieure du genou corps calleux. La comparaison inverse ne révèle aucun résultat significatif ni l’analyse des cartes de MD. Conclusions Ces résultats sont en accord avec les modèles physiopathologiques selon lesquels le primum movens dans la MP se situe dans une dysfonction synaptique et axonale (6,7). Une augmentation des valeurs de FA de la matière blanche dans la MP est en contradiction avec la plupart mais pas toutes (8,9) les études précédentes. L’hypothèse d’une diminution relative des fibres de croisement dans ces régions chez les patients mérite d’être testée au moyen de méthodes d’acquisition et d’analyse plus élaborées. Références 1. Nagy Z, et al. Magn Reson Med 2008; 60(5):1256-1260. 2. Leemans A, et al. Proc Intl Soc Mag Reson Med 17 2009;3537. (Abstract). 3. Chang LC, et al. Magn Reson Med 2005;3(5):1088-1095. 4. Smith SM et al. Neuroimage 2006; 31(4):1487-1505. 5. Catani M, et al. Cortex 2008; 44(8):1105-1132. 6. Schulz-Schaeffer WJ. Acta Neuropathol 2010; 120(2):131-143. 7. Cheng HC, et al. Ann Neurol 2010; 67(6):715-725. 8. Tessa C, et al. AJNR 2008; 29(4):674-680. 9. Wang JJ et al. Radiology 2011; 261(1):210-217. Remerciements Ce travail est financé par le Fonds de la Recherche Scientifique (FNRS-FRS) de la Communauté Française de Belgique. [less ▲]

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See detailConstraints on the Parental Melts of Enriched Shergottites from Image Analysis and High Pressure Experiments
Collinet, Max ULg; Medard, Etienne; Devouard, Bertrand et al

Poster (2012, March 20)

Martian basalts can be classified in at least two geochemically different families: enriched and depleted shergottites. Enriched shergottites are characterized by higher incompatible element ... [more ▼]

Martian basalts can be classified in at least two geochemically different families: enriched and depleted shergottites. Enriched shergottites are characterized by higher incompatible element concentrations and initial 87Sr/86Sr and lower initial 143Nd/144Nd and 176Hf/177Hf than depleted shergottites. It is now generally admitted that shergottites result from the melting of at least two distinct mantle reservoirs. Some of the olivine-phyric shergottites (either depleted or enriched), the most magnesian Martian basalts, could represent primitive melts, which are of considerable interest to constrain mantle sources. Two depleted olivine-phyric shergottites, Yamato 980459 and Nothwest Africa (NWA) 5789, are in equilibrium with their most magnesian olivine and their bulk rock compositions are inferred to represent primitive melts. Larkman Nunatak 06319 and NWA 1068, the most magnesian enriched basalts, have bulk Mg# that are too high to be in equilibrium with their olivine megacryst cores. Parental melt compositions have been estimated by subtracting the most magnesian olivine from the bulk rock composition, assuming that olivine megacrysts have partially accumulated. However, because this technique does not account for the actual petrography of these meteorites, we used image analysis to study these rocks history, reconstruct their parent magma and understand the nature of oli-vine megacrysts. Our image analysis results are supported by a series of high-pressure experiments performed on LAR 06319 bulk rock composition to test if it could represent a primitive melt, and understand its crystallization history. [less ▲]

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See detailDoes Tight Glycemic Control positively impact on patient mortality?
Penning, Sophie ULg; Le Compte, Aaron J.; Signal, Matthew et al

Poster (2012, March 20)

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See detailInteractions of apamin with pore mutated SK3 channels
Dilly, Sébastien ULg; Lamy, Cédric; Poncin, Sylvie et al

Poster (2012, March 16)

In the present work, we have tested the impact of the replacement of valine residues in the pore region of SK3 (520) by either an alanine or a phenylalanine residue in terms of the interactions of apamin ... [more ▼]

In the present work, we have tested the impact of the replacement of valine residues in the pore region of SK3 (520) by either an alanine or a phenylalanine residue in terms of the interactions of apamin with these mutants in comparison with the corresponding native channels. Replacing valine residue at position 520 of the SK3 channel by a phenylalanine significantly increased the sensitivity of the channel to be blocked by tetraethylammonium (TEA) as previously reported. Indeed, an aromatic residue, such as a phenylalanine or a tyrosine, is frequently found in the pore region of several potassium channels more sensitive to TEA than SK channels. We measured the affinity (Kd) of apamin in saturation experiments and studied SK currents in transfected cells using patch clamp techniques. In parallel, molecular modelling techniques were used to examine the impact of these local modifications on the interaction of apamin with the corresponding channels. The presence of a phenylalanine in the pore region of potassium channels led to a higher sensitivity for TEA by creating more hydrophobic interactions as found by the docking procedure. In the in vitro binding experiments, the phenylalanine mutant (SK3VF) displayed a very low affinity for apamin. In patch clamp experiments, the SK current was only very partially blocked by apamin in the SK3VF mutant. Furthermore, apamin displayed an affinity and a blocking activity for the alanine mutant close to that for the corresponding native channels. In conclusion, the presence of a bulky and hydrophobic residue at a position near the pore mouth of SK3 channels has a negative impact on their interactions with apamin. [less ▲]

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See detailApplication of mixed polygenic model to control for cryptic/genuine relatedness and population stratification.
Gusareva, Elena ULg; Mahachie John, Jestinah ULg; Isaacs, Aaron et al

Poster (2012, March 12)

In genome-wide association studies (GWAs), population stratification may cause inflated type I errors and overly-optimistic test results, when not properly corrected for. During the past decade, several ... [more ▼]

In genome-wide association studies (GWAs), population stratification may cause inflated type I errors and overly-optimistic test results, when not properly corrected for. During the past decade, several methods have been proposed for association testing in the presence of population stratification. Among these, principal components-based approaches are the most popular. Principal component analysis (PCA) allows data transformation to a new coordinate system such that the projection of the data along the first new coordinate (called the PC1) has the largest variance; the second PC has the second largest variance, and so on. In practice, two components are usually enough to adjust or to control for population stratification. They can easily be included in parametric association models as covariates. Despite the success of this strategy, there are still some caveats which need further attention. Among these are that principal component-based methods generally do not account for cryptic relatedness (kinship) between supposedly unrelated individuals, are not straightforwardly adapted to accommodate family-based designs or mixtures of families and unrelated individuals, and do not always take proper account of the trait under investigation. In this work, we present an easy-to-use alternative that addresses the aforementioned issues. For quantitative traits, we propose to first use the mixed polygenic model (possibly taking into account important non-genetic confounders as covariates), second to derive “polygenic” residuals from this model – hereby removing genomic kinship relationships, and third to consider these residuals as new traits in a classical genome-wide QTL analysis for “unrelated individuals”. The polygenic component of the aforementioned mixed polygenic model describes the contribution from multiple independently segregating genes, all having a small additive effect on the trait under investigation. Via an extensive simulation study, with various settings of population stratification and admixture, we show that this approach not only removes most of the “relatedness” between individuals (cryptic relatedness or known relatedness), but also removes most of the remaining substructures caused by population stratification or admixture. As a proof of concept, we demonstrate the efficiency of this robust method to control for population stratification on real-life genome-scale data from the SNP Health Association Resource (SHARe) Asthma Resource project (SHARP) (dbGaP accession number phs000166.v2.p1). We also provide leads to extend this method to dichotomous traits. [less ▲]

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See detailL'entomophagie basée sur la production locale d'insectes comestibles : sommes-nous prêts ?
Sablon, Ludovic ULg; Alabi, Taofic Abdel Fabrice ULg; Drugmand, Didier et al

Poster (2012, March 07)

Les perspectives d’évolution de la population mondiale annoncent un accroissement continu menant à un niveau supérieur à 9 milliards d’individus d’ici 2050. Cette augmentation correspondra inévitablement ... [more ▼]

Les perspectives d’évolution de la population mondiale annoncent un accroissement continu menant à un niveau supérieur à 9 milliards d’individus d’ici 2050. Cette augmentation correspondra inévitablement à des besoins alimentaires accrus au niveau mondial. Même si des spécificités en terme de produits consommés et de disponibilités – facilités de productions varient d’une région à une autre, la limitation des superficies à consacrer aux productions agricoles, notamment dans le cadre des ressources animales est une constante. Il ne sera pas possible d’assurer des productions animales conventionnelles pour fournir les ressources nécessaires aux populations humaines à venir. Bien que les produits animaux comme sources de nutriments doivent être développés, il s’agit maintenant de se tourner vers des filières alternatives pour maximiser les ressources végétales utilisées en élevage, tout en minimisant l’espace nécessaire et les effets sur l’environnement, notamment en terme de résidus et polluants potentiels. L'entomophagie, ou le fait de consommer des insectes comme source alimentaire d’origine animale, est connue et pratiquée dans de nombreuses régions du monde depuis des siècles. A chaque situation locale, une solution entomologique comme ressource alimentaire peut être appliquée : par la collecte dans la nature ou par le développement d’élevage d’espèces indigènes. Si l’entomophagie est peu appliquée en Europe, c’est sans doute d’une part lié à une absence dans nos mœurs alimentaires et d’autre part lié à la diversité et l’abondance d’autres ressources animales plus conventionnelles dans notre référentiel occidental. Au vu de l’état prévisionnel de la difficulté à produire les ressources alimentaires animales dans un futur proche, peut-être est-il temps de ne plus considérer les insectes comme uniquement nuisibles et négatifs mais plutôt comme de nouvelles espèces à développer par exemple dans des productions industrielles. Si la taille de ces animaux d’élevage reste réduite, leurs capacités de reproduction, leurs courtes durées de développement et les taux de conversion de la biomasse végétale utilisée comme aliments nous permettent d’envisager des unités de production de tonnes de biomasses animales. En plus de cet aspect quantitatif, plusieurs paramètres qualitatifs font de nombreux insectes des ressources utiles notamment en terme de protéines (et plus particulièrement en terme de composition en acides aminés plus rares) et de lipides (avec une majorité d’acides gras insaturés, des ratios omégas 3 et 6 intéressants, l’absence de cholestérol,…). Chez nous l'entomophagie est encore méconnue même si l'on peut constater un intérêt croissant notamment ces derniers mois. Entre curiosité gustative, éveil environnementaliste lié au faibles quantités de résidus liées à la production d’insectes vis-à-vis d’autres élevages, ou efficacité de transformation de ressources végétales limitées, de plus en plus de personnes souhaitent franchir le pas de ne plus regarder mais bien goûter de l’insecte. Dans le cadre de plusieurs études menées à Gembloux Agro-Bio Tech – Université de Liège ainsi qu’à l’Insectarium Jean Leclercq – Hexapoda à Waremme, certains aspects socio-culturels liés à une diversité de préparations à base d’insectes ont été investigués. Des tendances nettes sur les critères menant à l’acceptation ou le refus catégorique de manger de l’insectes ont ainsi été déterminés. Aussi, des formulations particulières peuvent également être ciblées pour favoriser l’appréciation de la dégustation d’insectes. Face au défi alimentaire du futur et à l'intérêt croissant pour l'entomophagie dans diverses régions dont l’Europe, l’élevage industriel d’insectes constitue une piste sérieuse pour fournir une part non négligeable de produits animaux afin d’assurer des ressources notamment de divers nutriments pour les populations humaines. Diverses recherches sont actuellement en cours tant sur les aspects techniques de production que sur les approches socio-culturelles. Nul doute que d’ici quelques années, entiers ou fractionnés les insectes feront partie de nos régimes et habitudes alimentaires. [less ▲]

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See detailHarmonized Growth Models and Simulations of the Evolution of Pure Stands of Norway spruce, Larches and Douglas-fir for Southern Belgium (Wallonia).
Perin, Jérôme ULg; Ligot, Gauthier ULg; Cerisier, François ULg et al

Poster (2012, March 02)

In order to compare different silvicultural scenarios we have undertaken the development of a software that can simulate stand evolution in regards to their species composition, site characteristics and ... [more ▼]

In order to compare different silvicultural scenarios we have undertaken the development of a software that can simulate stand evolution in regards to their species composition, site characteristics and silvicultural operations. As a first approach we limited the scope of our work to even-aged and pure coniferous stands of the three most important coniferous species in Wallonia (southern part of Belgium): Norway spruce (Picea abies), douglas-fir (Pseudotsuga menziensii) and larches (Larix sp.). This presentation introduces carried out simulations and compare their outcomes. First we gathered data sets from the permanent regional inventory, from observation networks and experimental plots throughout Wallonia. Then we adjusted, for these species, harmonized and distance-independent models of dominant-height growth, tree diameter growth, mortality, and the distribution of tree diameter frequency before the first thinning. Next we implemented those models in the Capsis platform, and we simulated, for the three species, the evolution of virtual stands using different scenarios. On one hand the evolution was performed without thinning, and on the other hand we applied silvicultural scenarios that are commonly used in Wallonia. As a result these models highlight, for example, the great juvenile growth and sensibility to stands density of larches whereas Norway spruce behaves the opposite. Further work is however needed to predict and simulate wood quality and value. Once this will be achieved we will attempt to optimize silvicultural scenarios for the three species. [less ▲]

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See detailSTEAM EXPLOSION : PROCESS AND IMPACT ON LIGNOCELLULOSIC MATERIAL
Jacquet, Nicolas ULg; Vanderghem, Caroline ULg; Danthine, Sabine ULg et al

Poster (2012, March 01)

Steam explosion is a thermomechanochemical process which allows the breakdown of lignocellulosic structural components by steam heating, hydrolysis of glycosidic bonds by organic acid formed during the ... [more ▼]

Steam explosion is a thermomechanochemical process which allows the breakdown of lignocellulosic structural components by steam heating, hydrolysis of glycosidic bonds by organic acid formed during the process and shearing forces due to the expansion of the moisture. The process is composed of two distinct stages: vapocracking and explosive decompression. Cumul effects of both phases include modification of the physical properties of the material (specific surface area, water retention capacities, color, cellulose crystallinity rate,…), hydrolysis of hemicellulosic components (mono and oligosaccharides released) and modification of the chemical structure of lignin. These effects permit the opening of lignocellulosic structures and increase the enzymatic hydrolysis rate of cellulose components in the aim to obtain fermentable sugars used in second generation biofuels process. [less ▲]

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See detailRecent disturbances in the Congo Basin : an anthracological contribution to vegetation reconstructions
Morin-Rivat, Julie ULg; Hubau, Wannes; Gillet, Jean-François ULg et al

Poster (2012, March 01)

In contrast to the well-known vegetation history of the northern hemisphere, few is known about past vegetation change in Central Africa. However, recent palaeoecological and biogeographical studies ... [more ▼]

In contrast to the well-known vegetation history of the northern hemisphere, few is known about past vegetation change in Central Africa. However, recent palaeoecological and biogeographical studies suggest that early human disturbances had a substantial influence on Central Africa vegetation patterns, particularly allowing the expansion of light-demanding species. This interesting hypothesis is the basis of one of the main research questions of the ERA-net BIODIVERSA CoForChange project: what was and is the relationship between (increasing) human activity and vegetation change? A recently developed protocol for the identification of ancient Central African charcoal fragments opened the door for vegetation reconstructions with a high spatial and taxonomical resolution. Therefore, we chose to study macro-charcoals from pedoanthracological profiles situated in N Congo and SE Camero0n. In total, 48 taxa were found in nine radiocarbon dated profiles. At the moment, three taxa have been identified down to species level. First, we found numerous fragments of Gilbertiodendron dewevrei under a current monodominant forest of G. dewevrei (40 cm depth, 1421-1327 cal. BP). This seems to confirm the presumption that monodominant forests of G. dewevrei, shade-bearer species, are relatively stable. Second, we evidenced the lack of Triplochiton scleroxylon charcoals under a T. scleroxylon stand, which could confirm the hypothesis of the recent nature of those stands. Finally, our results suggest that taxonomic diversity of charcoal findings in open canopy Marantaceae forests is greater than in dense forests. Pterocarpus soyauxii and Millettia drastica have been found under an open Marantaceae forest at 40 cm depth (1184-1055 cal. BP). The abundance of the light-demanding species P. soyauxii appears to be decreasing over time (levels 20 to 40 cm depth) to the benefit of giant herbs. Anthracology in Central Africa is on the rise and the first results of the CoForChange project are promising. More identifications will follow, resulting in a better understanding of the evolution of Central African forests. [less ▲]

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See detailCould current Pericopsis elata (Fabaceae) patches in southeastern Cameroon be reasonably linked to past anthropogenic activities ?
Bourland, Nils ULg; Cerisier, François ULg; Livingstone Smith, Alexandre et al

Poster (2012, March 01)

Pericopsis elata is one of the most valuable African timber species. This IUCN Red Listed tree suffers from a lack of regeneration, thus its current presence provokes questioning. Our work aimed at ... [more ▼]

Pericopsis elata is one of the most valuable African timber species. This IUCN Red Listed tree suffers from a lack of regeneration, thus its current presence provokes questioning. Our work aimed at understanding its origins so as to help securing its future. This study, lead away from engineering works, was conducted in four different sites located within the natural distribution area of the species and took into account the different growing conditions were the species occurs. Our observations were based on an analysis of charcoal elements and pottery fragments discovered in subsurface layers of soils as well as on current botanical and pedological surveys. Discovered evidence of past human activities led to the assumption that this part of the Congo Basin was much more inhabited than previously thought. Some of the results obtained for P. elata could apply for other long lived light demanding species growing in the same environment. [less ▲]

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See detailINFLUENCE OF STEAM EXPLOSION ON CRYSTALLINITY PROPERTIES OF PURE CELLULOSE FIBER
Jacquet, Nicolas ULg; Vanderghem, Caroline ULg; Danthine, Sabine ULg et al

Poster (2012, March 01)

The aim of the present study is to compare the effect of different steam explosion treatments on crystallinity properties of a pure bleached cellulose. Steam explosion process is composed of two distinct ... [more ▼]

The aim of the present study is to compare the effect of different steam explosion treatments on crystallinity properties of a pure bleached cellulose. Steam explosion process is composed of two distinct stages: vapocracking and explosive decompression. The treatment intensities is determined by a severity factor, established by a correlation between temperature process and retention time. The results show that steam explosion treatment has an impact on the crystallinity properties of pure cellulose fiber. When the severity factor is below 5.2, an increase of the overall crystallinity of the samples is observed with the treatment intensities. For higher intensities, a significant thermal degradation of cellulose lead to an important change in substrate composition, which lead to a further decrease of cellulose crystallinity [less ▲]

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See detailHow pristine is the Congo Basin forest ? Some answers from Erythrophleum spp. (Caesalpiniaceae) and Pericopsis elata (Fabaceae) natural stands in southeastern Cameroon
Bourland, Nils ULg; Livingstone Smith, Alexandre; Guion, Hélène ULg et al

Poster (2012, March 01)

Erythrophleum spp. and Pericopsis elata are two important African timber taxa suffering from regeneration problems. Those light demanding trees could have established in openings made by past human ... [more ▼]

Erythrophleum spp. and Pericopsis elata are two important African timber taxa suffering from regeneration problems. Those light demanding trees could have established in openings made by past human activities (mainly slash-and-burn cultivation). Our study aimed at verifying this assumption in a 340,000 ha forest concession in southeastern Cameroon. Anthracological excavations were made alongside transects opened in patches where those taxa occur as well as the surrounding environment. Numerous charcoal elements and some pottery fragments were found in excavated soils in all studied sites. Charcoals and pieces of pottery were found within the first 100 and 50 cm of soil, respectively. According to radiocarbon dating conducted on charcoals and burnt seeds, fires occurred between 2,150 to 195 years BP. This finding was consistent with the analysis of archaeological materials decoration techniques. Our results revealed intense past anthropological activities in this area, seriously questioning the assumption of a pristine Congo Basin [less ▲]

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See detailSMALL SAMPLE SIZE CAPABILITY INDEX FOR ASSESSING VALIDITY OF ANALYTICAL METHODS
Rozet, Eric ULg; Boulanger, B.; Ziemons, Eric ULg et al

Poster (2012, March)

Analytical method’s capability evaluation can be a useful methodology to assess the fitness of purpose of these methods for their future routine application. However, care on how to compute the capability ... [more ▼]

Analytical method’s capability evaluation can be a useful methodology to assess the fitness of purpose of these methods for their future routine application. However, care on how to compute the capability indices has to be made. Indeed, the commonly used formulas to compute capability indices such as Cpk, will highly overestimate the true capability of the methods. Especially during methods validation or transfer, there are only few experiments performed and, using in these situations the commonly applied capability indices to declare a method as valid or as transferable to a receiving laboratory will conduct to inadequate decisions. In this work, an improved capability index, namely Cpk-tol and the corresponding estimator of proportion of non conforming results (tolCpk−π) is proposed. Through Monte-Carlo simulations, they have been shown to greatly increase the estimation of analytical methods capability in particular in low sample size situations as encountered during methods validation or transfer. Additionally, the usefulness of this capability index is illustrated through several case studies. [less ▲]

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See detailOptimalisation d’une RT-PCR en temps réel pour la détection du virus de l’hépatite A
Zonta, William ULg; Denayer, Sarah; Thiry, Etienne ULg et al

Poster (2012, March)

En Belgique, l’incidence de l’hépatite A (HAV) est de 1,2 cas pour 100000 habitants. La population présente une faible immunité contre le HAV puisque seulement 50 % de la population possèdent des ... [more ▼]

En Belgique, l’incidence de l’hépatite A (HAV) est de 1,2 cas pour 100000 habitants. La population présente une faible immunité contre le HAV puisque seulement 50 % de la population possèdent des anticorps anti-HAV après l’âge de 30 ans. Ainsi un grand nombre d’individus reste susceptible de contracter une infection par le HAV. Les sources de contamination sont principalement le contact de personne à personne mais aussi la consommation d’aliments (crus ou « ready-to-eat) contaminés. Cette contamination peut provenir de l’eau d’irrigation pour les fruits et légumes, de l’eau de mer pour les mollusques bivalves ou de la manipulation de l’homme lors des différentes étapes entre la récolte et la vente du produit. Dans ce projet, une nouvelle RT-PCR spécifique pour la détection du HAV est développée et évaluée. Pour choisir de nouvelles amorces et sondes, des alignements sont réalisés avec les séquences de 19 souches de HAV (DNASTAR Lasergene) afin de cibler les régions les plus conservées du génome du HAV. Cinq nouveaux couples d’amorces ciblant plusieurs régions hautement conservées du génome de HAV ont été sélectionnés et testés à différentes températures d’hybridation et différentes concentrations en utilisant un agent se liant à l’ADN double brin (SYBR Green). Une sonde fluorescente, de type FAM, spécifique de l’amplicon délimité par le couple d’amorces fournissant les meilleurs résultats a été dessinée et utilisée avec la technologie d’hydrolyse de sonde à deux concentrations différentes. Des dilutions d’un facteur 10 de la suspension de la souche HM175 (HAV) ont été testées par le couple d’amorces et la sonde choisit pour établir ainsi une limite de détection. La spécificité du couple d’amorce choisit a été testé en présence de différents picornavirus et virus entériques et de 3 génotypes de HAV (IA, IB et IIIA). Le plasmide Sybricon019 et ses amorces spécifiques ont été utilisés comme contrôle interne d’amplification (IAC). Un contrôle positif a aussi été créé afin de s’assurer du fonctionnement correct de la PCR en temps réel. Parmi les 5 couples d’amorces sélectionnés, le couple HAV-F2/HAV-R2 permet d’obtenir les valeurs de Ct les plus faibles avec une concentration optimale de 300nM pour les amorces sens et anti-sens. Ce couple d’amorces cible la région VP1/VP3 du génome du HAV. Différentes températures d’hybridation ont été testées et la température la plus élevée (60°C) a été sélectionnée pour limiter le risque d’amplification aspécifique. Pour augmenter la spécificité, une sonde, HAV P2, spécifique de l’amplicon délimité par les amorces HAV-F2 et HAV-R2, est utilisée à la concentration de 250nM. Des dilutions d’un facteur 10 d’une suspension de HAV, 107 à 101 particules infectieuses par ml (déterminées par TCID50), donnent respectivement des valeurs de Ct de 19,2 à 38,4 et les dilutions de 100 à 10-2 particules infectieuses par ml ne donnent aucune amplification. La limite de détection est donc de 10 particules infectieuses par ml. La spécificité des amorces et de la sonde pour la détection du HAV est correcte puisque les trois génotypes de HAV, IA, IB et IIIA, ont été détectés alors que les différents picornavirus et virus entériques n’ont donné aucun signal fluorescent d’amplification. L’optimalisation d’un nouveau couple d’amorce et d’une sonde (HAV-F2, -R2 et -P2) ciblant une région hautement conservée du génome permet de détecter le virus HAV par RT-PCR. La région ciblée (VP1/VP3) diffère de la plupart des méthodes de détection de HAV par PCR en temps réelle décrites à ce jour. La seconde étape consiste à réaliser une série de tests dans différentes matrices alimentaires à risque (fruits de mer, fruits et légumes crus) dans le but de détecter des échantillons naturellement contaminés par le HAV. [less ▲]

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See detailSituation épidémiologique du virus de l’hépatite E chez le sanglier (Sus scrofa) en Belgique
Thiry, Damien ULg; Mauroy, Axel ULg; Brochier, Bernard et al

Poster (2012, March)

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See detailPilot Trial of STAR in Medical ICU
Fisk, Liam M.; Le Compte, Aaron J.; Shaw, Geoffrey M. et al

Poster (2012, March)

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See detailDu traumatisme obstétrical à la désinsertion trachéale.
Lecomte, Laurie; DEMEZ, Pierre ULg; François, Anne et al

Poster (2012, March)

Les désinsertions trachéales traumatiques néonatales sont exceptionnelles. Elles sont généralement associées à une intubation compliquée, mais quelques descriptions ont été faites de ruptures trachéales ... [more ▼]

Les désinsertions trachéales traumatiques néonatales sont exceptionnelles. Elles sont généralement associées à une intubation compliquée, mais quelques descriptions ont été faites de ruptures trachéales partielles dans le décours d’un traumatisme obstétrical. Quelle que soit l’étiologie de la lésion trachéale, la prise en charge peut être conservatrice (par cicatrisation « simple » autour d’un tube entotrachéal) ou chirurgicale (par réparation des lésions). [less ▲]

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See detailAN INNOVATIVE APPROACH TO SELECT THE PREDICTION MODEL IN THE DEVELOPMENT OF NIR SPECTROSCOPIC METHODS
Ziemons, Eric ULg; Mantanus, Jérôme ULg; Rozet, Eric ULg et al

Poster (2012, March)

Taking into account its non-invasive, non-destructive character and fast data acquisition, near infrared spectroscopy is more and more integrated in production processes to acquire analytical results ... [more ▼]

Taking into account its non-invasive, non-destructive character and fast data acquisition, near infrared spectroscopy is more and more integrated in production processes to acquire analytical results. Implementation of a NIR quantitative method is performed using an iterative heuristic approach that will ultimately build a model allowing the prediction of the concentration of the analyte of interest. In this context, the aim of the present study was to develop an innovative approach based on statistical tolerance intervals and the desirability index FMI (Fitting Model Index) to select the most appropriate prediction model from a list of candidate models instead of using conventional criteria such as R², RMSEC, RMSECV and RMSEP [1-2] without objective decision rules. This new approach is illustrated on different steps of a real pharmaceutical manufacturing process: water and Active Pharmaceutical Ingredient (API) determinations in pharmaceutical pellets. Variability sources such as production campaigns, batches, days and operators were introduced in the calibration and validation sets. Partial Least Square (PLS) regression on the calibration sets was performed to build prediction models of which the ability to quantify accurately was tested with the validation sets. Regarding the product specifications, the acceptance limits were set at 20% and 5%, for the moisture and API determination, respectively.As can be seen from Figure 1 and 2, this innovative approach based on the desirability index FMI of the accuracy profile enabled to build and select the most appropriate prediction model in full accordance with its very final goal, to quantify as accurately as possible the analytes of interest. [1] Hubert Ph. et al., J. Pharm. Biomed. Anal., 36, 2007, 579-586. [2] Rozet E. et al., Ana. Chim. Acta, 591, 2007, 239-247. [less ▲]

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See detailFoodborne Outbreak by a Recombinant Norovirus GIIg/1 Strain in a University Hospital in Munich
Hoffmann, Dieter; Mauroy, Axel ULg; Foley, Brian et al

Poster (2012, March)

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See detailAnalysis of tobacco mainstream smoke by GC×GC TOFMS
Brokl, Michal ULg; Bishop, Louise; Wright, Christopher et al

Poster (2012, March)

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See detailDelayed puberty in a girl due to an inactivating mutation of the LH receptor
FUDVOYE, Julie ULg; PARENT, Anne-Simone ULg; Bourguignon, Jean-Pierre ULg

Poster (2012, March)

We report the case of a 46 XY patient with a disorder of sex differentiation (DSD) caused by an inactivating mutation of the LH receptor. Mutations of genes involved in hypothalamic-pituitary-gonadal ... [more ▼]

We report the case of a 46 XY patient with a disorder of sex differentiation (DSD) caused by an inactivating mutation of the LH receptor. Mutations of genes involved in hypothalamic-pituitary-gonadal function are rare but they provide an experience of nature for understanding the physiology and the pathophysiology of gonadotropins actions. There arise from correlation between the phenotypes and genotypes in those unique conditions. Management of this particular patient with no LH activity involves oestrogen replacement therapy to induce breast development together with a gonadectomy due to the risk of gonadoblastoma in streak gonads. [less ▲]

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See detailProtocol 3 : Belgian innovative projetcs to help community dwelling frail elderly
de Almeida Mello, J; Maggi, Patrick ULg; Van Durme, T et al

Poster (2012, March)

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See detailRisques d'introduction des alphavirus responsables des encéphalites virales équines américaines en Belgique
De la Grandière de Noronha Cotta, Maria Ana ULg; Dal Pozzo, Fabiana ULg; Francis, Frédéric ULg et al

Poster (2012, March)

Les virus transmis par des arthropodes hématophages (arbovirus) représentent une menace pour la santé animale et humaine en fonction de l’augmentation de l’émergence des arboviroses en dehors des ... [more ▼]

Les virus transmis par des arthropodes hématophages (arbovirus) représentent une menace pour la santé animale et humaine en fonction de l’augmentation de l’émergence des arboviroses en dehors des territoires endémiques. Les arbovirus étudiés ici appartiennent au genre Alphavirus et à la famille des Togaviridae, et sont composés d’un génome à ARN simple brin de polarité positive et enveloppés. Ces virus sont des pathogènes exotiques des équidés et causent des maladies graves chez l’homme lors d’épidémies. Les arbovirus présentent une épidémiologie complexe car ils se retrouvent au centre de l’interaction avec 5 composants : le virus, le vecteur, le réservoir, les espèces animales sensibles et l’environnement. Les voies d’introduction possible en Belgique de ces virus ont été investiguées ici en fonction des caractéristiques étiologiques et épidémiologiques de chaque virus. L’encéphalite équine de l’Est (EEEV) a un cycle complexe principal incluant les oiseaux et des moustiques comme Culiseta melanura. Les souches nord-américaines et sud-américaines peuvent être différenciées antigéniquement et génétiquement et ont des différences importantes dans leur cycle de transmission et au niveau de leur virulence. Le cycle naturel de l’EEEV se réalise chaque année dans des zones marécageuses et la migration d’oiseaux virémiques serait une hypothèse à sa réintroduction printanière annuelle. Certaines années, le virus peut être amplifié pendant ce cycle oiseaux-moustiques et le virus devient disponible à d’autres espèces de vecteurs qui font le pont entre les oiseaux et les humains ou d’autres mammifères comme les chevaux. Grâce à cette observation, l’EEEV a pu être isolé de vecteur comme Ochlerotatus sollicitans, Coquillettidia perturbans ou encore Culex pipiens et Aedes vexans qui sont deux espèces bien présentes en Europe. Le risque d’importation de l’EEEV semble peu élevé, elle pourrait se faire par l’intermédiaire du transport volontaire ou involontaire, légal ou illégal d’espèces réservoirs d’oiseaux comme des passériformes (ex : moineau domestique ou des oiseaux d’eau (ex : Egretta thula), des rongeurs comme le rat des cotonniers, des vertébrés ectothermiques comme les amphibiens (ex : Rana catesbeiana) ou des reptiles (ex : Agkistrodon piscivorus), ou encore par le transport accidentel de vecteurs compétents. L’encéphalite équine de l’Ouest (WEEV) est retrouvée dans l’Ouest de l’Amérique du Nord et en Amérique du Sud. Ce virus est un virus recombinant entre le Sindbis virus et l’EEEV. Le virus est inclus dans un cycle qui implique des passereaux et Culex tarsalis. Un deuxième cycle moins connu est rapporté et implique un lapin ou lièvre sauvage (Lepus europaeus) avec un moustique du genre Aedes. Comme pour l’EEEV, les humains et les chevaux ne développent pas une virémie suffisante pour infecter les moustiques et continuer le cycle. Le WEEV pourrait être introduit en Europe par différentes voies : les vecteurs arthropodes adultes infectés ou leurs œufs pour Aedes dorsalis, l’introduction d’oiseaux comme des passériformes ou des mammifères comme le lièvre sauvage virémiques. L’acquisition de la compétence d’un vecteur indigène local comme Culex pipiens ou Aedes dorsalis doit aussi être envisagée. Le groupe des virus de l’encéphalite équine vénézuélienne (VEEV) est sous-divisé en souches enzootiques et souches épizootiques qui utilisent le cheval comme hôte amplificateur. Les souches épizootiques sont opportunistes pour leur choix de vecteurs avec comme conséquence un large panel de vecteurs potentiels. L’introduction et l’établissement de ce virus en Belgique est possible via des moustiques infectés, des rongeurs comme le rat des cotonniers ou des oiseaux d’eau infectés, des chevaux et des hommes infectés qui sont des hôtes amplificateurs pour les souches épizootiques. En conclusion, il convient de faire la distinction entre l’introduction et l’établissement d’une infection de ces virus en Belgique. L’introduction peut se faire par l’intermédiaire de vecteurs insectes ou d’hôtes oiseaux ou mammifères comme les rongeurs ou encore le cheval et l’homme dans le cas du VEEV épizootique. Le maintien de l’infection nécessite la présence de vecteurs indigènes avec une compétence vectorielle ou de vecteurs compétents invasifs pour ces virus ainsi que la présence d’hôtes mammifères ou oiseaux phylogénétiquement apparentés à des espèces réservoirs dans les régions américaines où ces virus sont endémiques. [less ▲]

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See detailAnthropisation des paysages: Structure spatiale, impact écologique, entropie
Vranken, Isabelle ULg; Bogaert, Jan ULg; Visser, Marjolein

Poster (2012, February 29)

Structural and thermodynamic applications of entropy related to spatial heterogeneity under growing anthropogenic pressure have been examined. 16 zones from classified LANDSAT TM scenes presenting ... [more ▼]

Structural and thermodynamic applications of entropy related to spatial heterogeneity under growing anthropogenic pressure have been examined. 16 zones from classified LANDSAT TM scenes presenting different anthropogenic effect intensities have been used. Anthropogenic effects, compositional and configurational entropy have been measured. The scatter plot shows bell curves with maximal entropy at intermediate anthropogenic effects. Distinction of natural and anthropogenic classes shows opposed tendencies according to class and compositional/configurational type. These results have been interpreted as spatial transformation processes, energy production and release, and linked to the habitat heterogeneity and intermediate disturbance hypotheses. [less ▲]

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See detailBiofuel by-product for poultry diets
Hissette, Mathias ULg; Destain, Jacqueline ULg; Thewis, André ULg et al

Poster (2012, February 28)

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See detailReconstruction of the long-term satellite-derived sea surface temperature in the South China Sea
Huynh, Thi Hong Ngu ULg; Alvera Azcarate, Aïda ULg; Barth, Alexander ULg et al

Poster (2012, February 24)

The AVHRR (Advanced Very High Resolution Radiometer) sea surface temperature is very useful for researches in oceanography because of its high resolution. An AVHRR limitation is the high missing data ... [more ▼]

The AVHRR (Advanced Very High Resolution Radiometer) sea surface temperature is very useful for researches in oceanography because of its high resolution. An AVHRR limitation is the high missing data percentage due to cloud coverage. In the South China Sea, the average missing data is usually more than 80%, especially more than 95% in the region near the Borneo Island. In this study, we use DINEOF tool to reconstruct a daily night-time AVHRR data set with horizontal resolution of 4km spanning from 1989 to 2009. Besides, a comparison between the results and in situ data is shown. The EOF analysis shows that the first three modes explain about 95% of seasonal variability. [less ▲]

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See detailViewing through the clouds in satellite images
Troupin, Charles ULg; Barth, Alexander ULg; Alvera Azcarate, Aïda ULg et al

Poster (2012, February 24)

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