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See detailBioRefine Project: Detection of bioavailability of Metallic Trace Elements in soils by the use of microbial biosensors
Tarayre, Cédric ULg; Hurdebise, Quentin ULg; Fischer, Christophe ULg et al

Poster (2014, September 09)

Zinc, lead and cadmium are the main Metallic Trace Elements (MTEs) found in soils contaminated by the mining industry in Europe. MTEs are spread in the environment because of the disruption of ... [more ▼]

Zinc, lead and cadmium are the main Metallic Trace Elements (MTEs) found in soils contaminated by the mining industry in Europe. MTEs are spread in the environment because of the disruption of biogeochemical cycles caused by human activities. Due to their low mobility and biodegradability, they accumulate in soils where they are strongly bound to particles. It has become necessary to understand interactions between MTEs and the environment and to implement remediation actions. This work is focused on remediation monitoring techniques by using whole cell microbial biosensors able to detect zinc, lead and cadmium. Biosensors provide a signal in response to the bio-available concentration in MTEs, which are valuable for the design of efficient techniques involving bioremediation. Whole cell biosensors used in this work are based on Escherichia coli strains carrying a fluorescent reporter system. The reporter element contains a promoter sensitive to MTEs and a gene coding for the Green Fluorescent Protein (GFP). MTEs activate the synthesis of GFP, which is a very stable protein, causing the accumulation of GFP inside the cells. Then, fluorescence can be measured by flow cytometry. In this study, two biosensors were investigated: E. coli pPzraPgfp and E. coli pPzntAgfp. The last strain provided a linear response to zinc up to 20 mg/l and a curvilinear response to cadmium up to 0.15 mg/l. No detection was highlighted regarding lead. In practical cases, soils and wastes are contaminated by several types of MTEs. Consequently, combined contaminations were also tested. This work allowed highlighting that the strain E. coli pPzntAgfp can be used to assess the bioavailability of cadmium in soils, although the experimental procedure must be improved. This work is supported by the BioRefine Project, a European project in which various member states focus on recovery of inorganics from organic wastestreams. We gratefully acknowledge the INTERREG IVB NWE programme, which financed the BioRefine Project (ref. 320J-BIOREFINE). [less ▲]

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See detailAGE-RELATED MACULAR DEGENERATION (AMD): FROM METABOLOMICS APPROACH TO THE INHIBITION OF PDK AS A NEW THERAPEUTIC TARGET
Arslan, Deniz ULg; Pirotte, Bernard ULg; De Tullio, Pascal ULg et al

Poster (2014, September 09)

Age-related Macular Degeneration (AMD) is a leading cause of vision loss in the western world among people aged 50 or older. 90% of all vision loss due to AMD results from the exudative form, which is ... [more ▼]

Age-related Macular Degeneration (AMD) is a leading cause of vision loss in the western world among people aged 50 or older. 90% of all vision loss due to AMD results from the exudative form, which is characterized by choroidal neovascularization (CNV). Age-related changes that induce pathologic CNV are incompletely understood. A successful application of anti-VEGF approaches in the clinic is obviously a turning point in AMD treatment. Nevertheless, despite such important advances, critical issues remain to be addressed. To better understand the aetiology of this pathology, we used and improved a murine model of laser-induced choroidal neovascularization and applied a 1H NMR metabolomics study. This approach leads to the emergence of different putative biomarkers and to the validation of the CNV model for an experimental study of AMD. Among these “biomarkers”, lactate appears to be clearly involved in the development of AMD. The modulation of their plasma concentration by treatment of the animals with synthetic compounds and more specifically Pyruvate Dehydrogenase Kinase inhibitors (PDK) significantly decrease the impact of laser induced CNV. Starting from these results, the development of new PDHK inhibitors could open the way to innovative treatment opportunities in AMD disease [less ▲]

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See detailVery deep images of the disc around beta Pictoris at Lp
Milli, J.; Absil, Olivier ULg; Mouillet, D. et al

Poster (2014, September 08)

We present observations of the innermost regions of the disc around beta Pictoris performed with VLT/NaCo in the Lp band. We combined seven deep datasets to retrieve the morphology of the disc down to 0 ... [more ▼]

We present observations of the innermost regions of the disc around beta Pictoris performed with VLT/NaCo in the Lp band. We combined seven deep datasets to retrieve the morphology of the disc down to 0.1arcsec. Our observations reveal intriguing ripples in the midplane of the disk at 0.5arcsec, as well as an overall bow of the disc spine, compatible with a disc slightly inclined with respect to edge-on scattering light anisotropically. Modelling suggests the presence of dust down to 10AU in order to explain the bright flux seen below 0.5 arcsec. [less ▲]

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See detailEffects of Dietary Protein Content on Second Reproductive Cycle of Local Rabbit Does and Their Litters.
SAIDJ, D.; AIN BAZIZ, H.; DAHMANI, Y. et al

Poster (2014, September 08)

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See detailStudy of the conditions of conidiation for the bio-fungicide Pseudozyma flocculosa
ZAKI, Omran

Poster (2014, September 07)

Pseudozyma flocculosa is a useful fungus and is used in biological control of mildew. The reproduction of this fungus seems to be exclusively asexual by conidia’s production. The latter physiological form ... [more ▼]

Pseudozyma flocculosa is a useful fungus and is used in biological control of mildew. The reproduction of this fungus seems to be exclusively asexual by conidia’s production. The latter physiological form seems to be resistant to downstream process and storage conditions. Therefore, it represents the most commonly form used in agriculture as Fungicide. However, production of conidia in submerged culture is usually uncertain, often with very low yield. Despite the advantages that P. flocculosa offers in biological control, its use remains largely limited compared with that of chemical fungicides. This is probably due to the difficulty to produce mature conidia with high yields. In this work, our aim is to decipher developmental phases of conidia by this useful strain. We start by conidia production in submerged and semisolid fermentation. We then focus on comparative study of different kinds of obtained conidia. [less ▲]

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See detailDesign of a fungal biofilm reactor for recombinant protein production from Aspergillus oryzae
Zune, Quentin ULg; Delepierre, Anissa ULg; Bauwens, Julien ULg et al

Poster (2014, September 07)

Fungi are microorganisms exhibiting high secretive power of various metabolites and have the ability to perform post-translational modifications during protein synthesis. In the field of fermentation ... [more ▼]

Fungi are microorganisms exhibiting high secretive power of various metabolites and have the ability to perform post-translational modifications during protein synthesis. In the field of fermentation industry, they are ideal hosts for secondary metabolites and recombinant protein production. At the industrial-scale, equipments usually required for solid-state or submerged fermentation of filamentous fungi have demonstrated their limitations in terms of productivity, mass transfers or products recovery (1, 2). Recently, fungal biofilm reactors were designed to combine advantages from submerged and solid-state culture and reveal their usefulness for greater secondary metabolites production relative to submerged culture conditions (3). In our work, we propose the design of a fungal biofilm reactor for a recombinant protein production from an Aspergillus oryzae strain containing a GFP reporter gene system under the control of a promoter specifically induced in solid-state conditions. The fungal biofilm reactor is composed of a metal structured packing, having the function of inert support for biofilm growth, immerged or aspersed by a liquid medium. Whereas recombinant protein production is not significantly different at the flask-scale between submerged and biofilm conditions, productivity is higher in the submerged conditions at the bioreactor-scale. Presence of recombinant proteins entrapped in the biofilm matrix highlights a diffusion constraint and a lower mass transfer in our fungal biofilm reactor. However, persistence of a free liquid biomass of low viscosity and fungal biomass retention on the support are attractive for the implementation of a continuous process in our fungal biofilm reactor. Further studies will consider a 2-D proteomic comparison of the extracellular medium from fungal biofilm reactor and submerged culture conditions in order to better understand proteins secretion and identify over-expressed proteins in biofilm conditions. [less ▲]

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See detailObservational signatures of past mass-exchange episodes in massive binaries
Raucq, Françoise ULg; Rauw, Grégor ULg; Gosset, Eric ULg et al

Poster (2014, September 05)

Mass and momentum exchanges in massive binaries can produce several observational signatures, such as asynchronous rotation and altered chemical compositions, which remain once the stars detach again. We ... [more ▼]

Mass and momentum exchanges in massive binaries can produce several observational signatures, such as asynchronous rotation and altered chemical compositions, which remain once the stars detach again. We have started to investigate these effects for a sample of detached massive O-star binaries that are thought to have previously experienced a Case A Roche lobe overflow. Using phase-resolved spectroscopy, we perform the disentangling of the spectra of the two stars. The reconstructed primary and secondary spectra are then analyzed to determine a range of stellar effective temperatures and gravity, as well as rotational velocities. Using model atmosphere codes we also constrain the chemical composition of the components. In this contribution, we present the first results of our analyses of HD149404 (O7.5If + ON9.5I, P = 9.81 days). [less ▲]

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See detailPredictive microbiology combined with metagenomic analysis targeted on the 16S rDNA : A new approach for food quality
Delhalle, Laurent ULg; Ellouze, Mariem; Taminiau, Bernard ULg et al

Poster (2014, September 01)

The food spoilage process is mainly caused by alteration micro-organisms and classical culture-based methods may not be relevant to understand the modifications of the microbial ecology in food products ... [more ▼]

The food spoilage process is mainly caused by alteration micro-organisms and classical culture-based methods may not be relevant to understand the modifications of the microbial ecology in food products. Metagenomic analysis targeted on 16S ribosomal DNA can elucidate microbial community structures at a muche higher resolution than was previously possible. Combined with predictive microbiological models, a new approach was investigated to take into account bacterial populations dynamics in perishable foods under different environmental conditions. White pudding samples, a typical Belgian pork meat product, were packed under food wrap (atmospheric air condition). Durability studies were conducted at 4°C, 12°C and a dynamic temperature profile according to the NF V01-003 standards (4°C (1/3 of the shelf life) - 8°C (2/3 of the shelf life)) during 15 days. The effect of organic acids was also investigated using a lactic acid (1.8% w/w) treatment. At each day of the trials, classical microbiological (total flora) and 16S rDNA metagenomic analysis were carried out on all these samples. For the metagenomic analysis, a sequencing library was generated, targeting the V1-V3 region of the 16S rDNA. The two major bacterial populations were thus identified (Psychrobacter sp and Brochotrix thermosphacta) and predictive microbiology models used to assess the growth parameters. Cardinal parameters for temperature were collected on the two main bacterial species. The model was validated using the data obtained at a dynamic temperature profile. The results of the simulations for Psychrobacter sp and Brochotrix thermosphacta show a good compliance between predicted and observed data. Compared to culture based methods on selective media and previous independent culture techniques, metagenomic analysis combined with predictive microbiology gives more valuable information, and could be considered as a technological breakthrough to control the quality or for accurately determining shelf life. [less ▲]

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See detailI know what you did last summer - High resolution mapping of wild boar damages with drones
Michez, Adrien ULg; Morelle, Kevin ULg; Lehaire, François ULg et al

Poster (2014, September 01)

Wild boar ability to cause important damages to agricultural lands is not anymore to be demonstrated. These damages often raise conflicts between farmers and hunters due to the associated economic losses ... [more ▼]

Wild boar ability to cause important damages to agricultural lands is not anymore to be demonstrated. These damages often raise conflicts between farmers and hunters due to the associated economic losses. Objective and accurate method for real impact assessment of losses suffered by farmers is thus needed. Currently,in Wallonia damage assessment is performed from the ground by experts, asked to evaluate precisely the area impacted. This task is time and man power consuming. Moreover, damaged areas are often large and consequently, sampling is mandatory and can induce accuracy issues. Recent development of unmanned aerial vehicle (UAV / drone) toghether with lower cost and better accessibility for civil society and scientific community, makes now possible the use of this technology for wildlife researches. Through photogrammetric 3D reconstruction of the field crop, UAV can allow to objectively and precisely measure the area impacted by wild boar damages. In a context of increasing issues caused by wild boar to agriculture, and the need for stakeholders for accurate impact assessment, we tested an innovative approach to estimate more effectively the area impacted by wild boar. [less ▲]

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See detailTHE BCCM/ULC CULTURE COLLECTION TO CONSERVE AND STUDY THE DIVERSITY OF (SUB)POLAR CYANOBACTERIA
Wilmotte, Annick ULg; Renard, Marine ULg; Kleinteich, Julia et al

Poster (2014, September)

The BCCM/ULC public collection of (sub)polar cyanobacteria is funded since 2011 by the Belgian Science Policy Office. A Quality Management System was implemented and is continuously improved since then ... [more ▼]

The BCCM/ULC public collection of (sub)polar cyanobacteria is funded since 2011 by the Belgian Science Policy Office. A Quality Management System was implemented and is continuously improved since then. An ISO9001 certificate was obtained for the public deposition and distribution of strains, as part of the multi-site certification for the BCCM consortium. BCCM/ULC is currently holding 134 cyanobacterial strains and the catalogue is available on http://bccm.belspo.be/catalogues/ulc-catalogue-search. Continuous maintenance of living cultures, some of which are also cryopreserved, ensure the preservation and the possibility to rapidly deliver strains to clients for fundamental and applied research. The collection includes 113 (sub)polar strains. In such extreme environments, cyanobacteria are important phototrophs and primary producers in terrestrial and freshwater ecosystems. The purpose of this collection is to gather a representative portion of the cyanobacterial diversity with different ecological origins (limnetic microbial mats, soil crusts, cryoconites, endoliths, etc.) and make it available for researchers to study the taxonomy, evolution, adaptations to environmental conditions, and genomic make-up. Thus, 102 cyanobacterial strains were isolated from the three main biogeographic zones of the Antarctic continent. In addition, 7 strains were isolated in Arctic biotopes and 4 from Siberian lakes. The molecular characterization is underway, on the basis of 16S rRNA and ITS sequences. Moreover, a Multilocus Sequence Analysis is tested on diverse strains to improve their systematics. The diversity encompasses the three main cyanobacterial orders: Chroococcales, Oscillatoriales and Nostocales. In addition, cyanobacteria are known to produce a range of secondary metabolites (e.g. alkaloides, cyclic and linear peptides, polyketides) with different bioactive properties (e.g. antibiotic, antiviral, antifungal, anticancer). The potential of the polar strains to produce cyanotoxins is currently studied by ELISA and the detection by PCR of genes involved in their production. Due to the geographic isolation and the strong environmental stressors of the habitat, the exploration of these metabolites in Antarctic cyanobacterial strains seems promising for biotechnology or biomedical applications. [less ▲]

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See detailAutomatic biorythms description from actigraphic data
González y Viagas, Miguel ULg; Ly, Julien ULg; Gaggioni, Giulia ULg et al

Poster (2014, September)

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See detailAutomatization of mirror - tracing skill in children with Developmental Coordination Disorder
Lejeune, Caroline ULg; Meulemans, Thierry ULg; Desmottes, Lise ULg et al

Poster (2014, September)

Aim: This study investigated the hypothesis of a skill automatization deficit in Developmental Coordination Disorder (DCD). Method: Thirty children (15 with DCD and 15 control children), aged between 7 ... [more ▼]

Aim: This study investigated the hypothesis of a skill automatization deficit in Developmental Coordination Disorder (DCD). Method: Thirty children (15 with DCD and 15 control children), aged between 7 and 12 years old, were administered the mirror-tracing task during two 10-trials sessions separated by one week. An auditory interference task was introduced at the end of the procedural learning phase to test skill automatization. Results: Interestingly, no between-group difference was revealed in learning and automatization measures except for a specific subgroup of DCD children (n=5) who experienced difficulties in skill automatization. Conclusion: The results of our preliminary study highlighted the heterogeneity of the deficit presented in DCD and they emphasized the importance to explore further the lack of automatization in DCD. [less ▲]

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See detailCortical excitability dynamics of during sleep deprivation set PVT performance
Borsu, Chloé; Gaggioni, Giulia ULg; Ly, Julien ULg et al

Poster (2014, September)

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See detailModelling the development of potential spoilage and biopreservative microorganisms on white pudding in different conditions of temperature based on classical microbiology and 16S rDNA metagenomic
Gand, Mathieu ULg; Cauchie, Emilie ULg; Kergourlay, Gilles ULg et al

Poster (2014, September)

An important way to prevent the spoilage of food is the respect of the cold chain during the storage. While the temperature instructions are generally respected during process and distribution of food ... [more ▼]

An important way to prevent the spoilage of food is the respect of the cold chain during the storage. While the temperature instructions are generally respected during process and distribution of food products, it is not always the case with the consumers. Indeed, a few persons reach the right temperature level required for a safe storage of foodstuffs in their refrigerator. Besides, the food can sometimes spend a few hours in ambient temperature between the buying in the supermarket and the storage in cold temperature. In this study, we propose to model the growth of microorganisms on white pudding, stored in different conditions of temperature that reflect the situations described above (constant 4°C, constant 8°C, constant 12°C, 1/3 4°C – 2/3 8°C, 1/3 4°C – breach during 4h at 20°C – 2/3 4°C and 1/3 4°C – breach during 4h at 20°C – 2/3 8°C. The product was surface inoculated with potential spoilage and biopreservative strains (Raoultella terrigena, Serratia quinivorans, Carnobacterium maltaromaticum, Lactobacillus oligofermentans, Lactobacillus nenjiangensis, Lactobacillus fuchuensis, Leuconostoc mesenteroides, lactococcus lactis and Lactobacillus graminis). Analyses by classical microbiology and V1-V3 16S rDNA metagenomics were done each day until the out of date of the food matrix. The transition from 4 to 8°C and the breach at 20°C during 4h have clearly boosted the growth of the microorganisms. The metagenomic analysis was a powerful tool to follow separately each population in each condition of storage. The results of this communication show the importance of keeping the foodstuffs in 4°C or lower in the refrigerator with the goal to avoid the spoilage or the development of pathogens and the potential of metagenomics for selection of biopreservative strains. [less ▲]

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See detailAssessment of a multiscale fatigue damage model associated with stress gradient effects
Duchene, Laurent ULg; Marmi, Abdeljalil ULg; Habraken, Anne ULg

Poster (2014, September)

The aim of this research work is to develop a finite element numerical tool able to predict accurately the fatigue life of mechanical components. These components can have complex geometries, they can be ... [more ▼]

The aim of this research work is to develop a finite element numerical tool able to predict accurately the fatigue life of mechanical components. These components can have complex geometries, they can be submitted to a complex loading, leading to a specific stress field with possible stress concentration. Additionally, the successive cycles of loading are not necessarily identical. It is expected that the numerical tool can handle these demanding constraints. In this respect, a multiaxial fatigue damage model was implemented in our home-made finite element code Lagamine. The finite element method permits to account for the actual geometry of the mechanical part and the loading for the stress computation in the whole structure. The formulation of the multiaxial fatigue model is able to capture: - The non linear damage accumulation for multiblock and variable cyclic loading, - The effect of the mean (hydrostatic) stress, - The effect of the cycles below the fatigue limit if the damage was previously initiated. Finally, the occurrence of stress concentration will significantly reduce the life time of the studied piece. However, it is well-known that the subsequent local degradation of the material will be partly compensated by an enhanced load carrying contribution of the surrounding material, favourably leading to a reduction of the crack propagation. The stress gradients computed with different techniques are incorporated in the model so as to account for such beneficial influence. The physical roots of this model depart from the mesoscopic length scale, where the damage evolution is related to the mesoscopic accumulated plastic strain. Therefore, the variables of the model are defined at both macroscopic and mesoscopic scales and a specific scale transition method was implemented, based on the well-known simplified Zarka method but used at the multiscale level. The predictive capabilities of this multiscale multiaxial model are assessed by means of comparison with the classical Lemaitre-Chaboche model (implemented in the same FE code with stress gradient effects). For both models, the material parameters were identified from SN tests on smooth specimens of Ti-6Al-4V alloy, while the predictions of the models are validated thanks to comparison with experimental tests on notched samples, with stress gradient effects. [less ▲]

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See detailIntroducing the Belgian Science and Technology Studies Network (BSTS)
Meyers, Gert; Van Oudheusden, Michiel ULg; Thoreau, François ULg et al

Poster (2014, September)

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See detailDo the counting methods distort our perception of bivalve diversity through time?
Ros-Franch, Sonia; Cascales - Miñana, Borja ULg; Martínez-Pérez, Carlos

Poster (2014, September)

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See detailAb-initio Study of Ferecrystals
Dewandre, Antoine ULg; Verstraete, Matthieu ULg

Poster (2014, September)

Ferecrystals are a new family of compounds first synthesized in 2007 by the group of D. Johnson at the University of Oregon. These materials consist of inter-growths of dichalcogenide and chalcogenide ... [more ▼]

Ferecrystals are a new family of compounds first synthesized in 2007 by the group of D. Johnson at the University of Oregon. These materials consist of inter-growths of dichalcogenide and chalcogenide layers, and can be written as [(M X)_{1+δ} ]_m [T X_2 ]_n where M = Sn, Pb, Sb, Ni and some rare earths; T = Ti, V, Cr, Nb and Ta; X= S and Se. The integers m and n denote the numbers of consecutive formula unit layers in the different components of the inter-growth. The δ parameter reflects the difference of the in-plane cell constants between components of the inter-growth. This family of nanostructured materials shows promising properties for thermoelectric devices. The compounds studied here are [(SnSe)_1.29 ]_{234} [M oSe_2 ]_1 . We performed structural characterisation and examined the transfer of charge at the interface between the two materials. We show that there is a depletion of charge at the interface between the two compo- nents of the heterostructures and that structural distortions of the SnSe layers in the supercell are similar to those observed in slab calculations. [less ▲]

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See detailModelling the development of potential spoilage and biopreservative microorganisms on precooked pasta in different conditions of temperature based on classical microbiology and 16S rDNA metagenomic
Gand, Mathieu ULg; Cargnel, Mickaël ULg; Kergourlay, Gilles ULg et al

Poster (2014, September)

An important way to prevent the spoilage of food is the respect of the cold chain during the storage. While the temperature instructions are generally respected during process and distribution of food ... [more ▼]

An important way to prevent the spoilage of food is the respect of the cold chain during the storage. While the temperature instructions are generally respected during process and distribution of food products, it is not always the case with the consumers. Indeed, a few persons reach the right temperature level required for a safe storage of foodstuffs in their refrigerator. Besides, the food can sometimes spend a few hours in ambient temperature between the buying in the supermarket and the storage in cold temperature. In this study, we propose to model the growth of microorganisms on precooked pasta, stored in different conditions of temperature that reflect the situations described above (constant 4°C, constant 8°C, constant 12°C, 1/3 4°C – 2/3 8°C, 1/3 4°C – breach during 4h at 20°C – 2/3 8°C and 1/3 8°C – breach during 4h at 20°C – 2/3 8°C. The product was surface inoculated with potential spoilage and biopreservative strains (Lactococcus piscium, Leuconostoc mesenteroides and Leuconostoc citreum). Analyses by classical microbiology and V1-V3 16S rDNA metagenomics were done each day until the out of date of the food matrix. The transition from 4 to 8°C and the breach at 20°C during 4h have clearly boosted the growth of the microorganisms. The metagenomic analysis was a powerful tool to follow separately each population in each condition of storage. The results of this communication show the importance of keeping the foodstuffs in 4°C or lower in the refrigerator with the goal to avoid the spoilage or the development of pathogens and the potential of metagenomics for selection of biopreservative strains. [less ▲]

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See detailUnveil the Mechanism of Action of Berenil, a DNA Binding Drug, on Trypanosoma cruzi
Zuma, Aline Araujo; Cavalcanti, Danielle Pereira; Thiry, Marc ULg et al

Poster (2014, September)

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See detailSELF BROADENING COEFFICIENTS AND IMPROVED LINE INTENSITIES FOR THE v7 BAND OF C2H4 NEAR 10.5 µm, AND IMPACT ON ETHYLENE RETRIEVALS FROM JUNGFRAUJOCH SOLAR SPECTRA
Vander Auwera, Jean; Fayt, André; Tudorie, Marcella et al

Poster (2014, September)

Relying on high-resolution Fourier transform infrared (FTIR) spectra, the present work involved extensive measurements of individual line intensities and self-broadening coefficients for the ν7 band of ... [more ▼]

Relying on high-resolution Fourier transform infrared (FTIR) spectra, the present work involved extensive measurements of individual line intensities and self-broadening coefficients for the ν7 band of 12C2H4. The measured self-broadening coefficients exhibit a dependence on both J and Ka. Compared to the corresponding information available in the latest edition of the HITRAN spectroscopic database, the measured line intensities were found to be higher by about 10 % for high J lines in the P branch and lower by about 5 % for high J lines of the R branch, varying between these two limits roughly linearly with the line positions. The impact of the presently measured line intensities on retrievals of atmospheric ethylene in the 949.0–952.0cm 1 microwindow was evaluated using a subset of ground-based high-resolution FTIR solar spectra recorded at the Jungfraujoch station. The use of HITRAN 2012 with line intensities modified to match the present measurements led to a systematic reduction of the measured total columns of ethylene by -4.1 +/- 0.1 %. [less ▲]

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See detailRole of estradiol in the feminization of lordosis behavior
Trouillet, Anne-Charlotte ULg

Poster (2014, September)

The classic theory of mammalian brain and behavioral sexual differentiation holds that an organizational action of testosterone, secreted perinatally by the male’s testes, controls male-typical aspects of ... [more ▼]

The classic theory of mammalian brain and behavioral sexual differentiation holds that an organizational action of testosterone, secreted perinatally by the male’s testes, controls male-typical aspects of brain and behavioral development, whereas no active perinatal sex hormone signaling is required for female-typical differentiation. However, it has recently been shown using aromatase knock out (ArKO) mice, which are deprived of estradiol due to a targeted mutation in the aromatase gene, that estradiol may also actively contribute to the differentiation of female-typical aspects of behavior over a specific pre-pubertal period. Sexual behavior is a well known sexually dimorphic behavior, and thus provides a good model for studying the sexual differentiation of the brain. Female ArKO mice showed significantly lower levels of lordosis behavior than wild type controls following adult ovariectomy and treatment with ovarian hormones. This deficit was restored by treating female ArKO mice with estradiol benzoate between postnatal days 15 and 25. However, the mechanism by which estradiol acts prepubertally in female mice to feminize lordosis behavior remains to be elucidated. Therefore, in a first attempt, we will determine which neuropeptides are in particularly sensitive to estradiol action over the prepubertal period. We will focus on neuropeptides which have been shown to be implicated in lordosis behavior. Studies by the group of Micevych have proposed an important role for NPY and beta-endorphin (B-END) neurons in the arcuate nucleus (ARC) in the estradiol-mediated activation of lordosis behavior in female rats. An in vitro study recently showed that kisspeptin directly activates arcuate (ARC) B-END neurons. This is particularly interesting since unpublished results from our laboratory showed that Kp neurons are directly involved in the expression of lordosis behavior. We are thus currently determining the expression of NPY, B-END, and kisspeptin in the ARC as well as μ-opioid receptors MORs in the MPN over the prepubertal period and their possible modulation by prepubertal estradiol treatment. Interestingly, we also observed that our treatment may have an organizational effect on the regulation of energy balance. Indeed, administration of estradiol over the prepubertal period restores a normal weight in ArKO mice, which are normally obese in adulthood. It has been shown that ArKO mice present a lower spontaneous physical activity which can be one cause of their obesity. However, our treated mice did not show an increase in their locomotion behavior. These new observations suggest that estradiol during prepubertal development may have an additional role in the organization of brain circuits regulating the energy balance. [less ▲]

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See detailEvaluation of Temocillin for treatment of nosocomial infections
LAYIOS, Nathalie ULg; CIUTEA, Mirela ULg; LONGUEVILLE, Manon et al

Poster (2014, September)

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See detailBatch enzymatic interesterification of fat blends using microwave
Danthine, Sabine ULg; Simon, C.; Richel, Aurore ULg et al

Poster (2014, September)

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See detailUsa de programa APS en el analysis de la forma de la arcada dental.
LEWY, Stéphanie; LIMME, Michel ULg; BRUWIER, Annick ULg

Poster (2014, September)

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See detailEffect of AMF enrichment with 13C-­‐triacylglycerol tracers on its thermal and structural behavior
Danthine, Sabine ULg; Vors, C.; Michalski, M-C

Poster (2014, September)

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See detailCarnobacterium maltaromaticum isolated from vacuum-packed beef with long shelf life: morphological and functional characterization
Didimo Imazaki, Pedro Henrique ULg; Tahiri, Assia ULg; Ndedi Ekolo, François et al

Poster (2014, September)

This study was conducted as part of a research project on meat conservability, in particular vacuum packaged beef displaying very long shelf lives at a temperature close to the freezing point, and its ... [more ▼]

This study was conducted as part of a research project on meat conservability, in particular vacuum packaged beef displaying very long shelf lives at a temperature close to the freezing point, and its objective was to perform a morphological and functional characterization of C. maltaromaticum with potential bioprotective effect isolated from vacuum packaged long shelf life beef. The isolated C. maltaromaticum strain presented similar morphological, biochemical and enzymatic profiles as those of two reference strains (LMG 11393 and LMG 22902). Among the studied conditions, a temperature of +12 °C and an atmosphere poor in oxygen (100 % N2) were the optimal conditions for the growth of C. maltaromaticum. Nevertheless, growth on lower temperatures is also possible. After inoculation of beef samples with C. maltaromaticum and 7 days of storage under vacuum at −1 °C, no effect was observed on the total viable count and on the count of lactic acid bacteria. A reduction of Pseudomonas sp. and Brochothrix thermosphacta was observed during the first week of storage under vacuum conditions. After 7 days of subsequent storage of the same samples under modified atmosphere at +4 °C, the inoculant favored the growth of B. thermosphacta and inhibited the growth of Enterobacteriaceae under 100 % N2. No effect of the inoculant was observed when an atmosphere rich in oxygen was applied. The evaluation of the influence of different atmospheres showed that the growth of C. maltaromaticum was slower in an atmosphere containing O2 and CO2. Long-term storage under vacuum at low temperatures are therefore suitable for the growth of this bacterium. An antimicrobial effect against Enterobacteriaceae was highlighted on inoculated fresh meat stored under N2. The functional characterization of this strain will be further pursued by genotypic characterization. Special attention will be taken to study its bioprotective properties. [less ▲]

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See detailPromoter specific regulation of NF-kappaB by RelA phosphorylation on Ser547
Trussart, Charlotte ULg; Orban, Tanguy; Di Valentin, Emmanuel ULg et al

Poster (2014, August 29)

NF-KB (p50/RelA) controls the expression of numerous genes involved in inflammation, survival, proliferation, and cancer initiation and progression. Both classical NF-kB activation by pro-inflammatory ... [more ▼]

NF-KB (p50/RelA) controls the expression of numerous genes involved in inflammation, survival, proliferation, and cancer initiation and progression. Both classical NF-kB activation by pro-inflammatory cytokines and ATM-dependant activation by DNA damage require IKK activation and IkBa degradation. Stimuli dependant phosphorylation of p65 controls its transcriptional potential often in a gene specific manner. Previously, we have reported a direct interaction between RelA and ATM, and, demonstrated the in vitro phosphorylation of Ser547 by this kinase. A comparative transcriptomic analysis performed in HEK cells expressing either p65WT or p65S547A identified several differentially transcribed genes after an etoposide treatment. Substitution of S547 to alanine does not affect p65 binding on the kB site of the modulated promoters but it reduces p65 interaction with HDAC1. The resulting enhanced histone H3 acetylation increases gene transcription at some specific promoters. Our data indicate that ATM regulates a sub-set of NF-kB dependent genes after a genotoxic stress by direct phosphorylation of p65. Presently, we are investigating the impact of p65S547A/D mutations after the addition of TNFa in Mefs p65 KO complemented with HA-p65WT or S547A/D. No differences are observed in the degradation of IkBb or the nuclear translocation of p50/p65. However both basal and TNFa-induced transcription levels of some kB dependent genes are elevated in Mefs expressing p65S547D. The role of ATM in NF-kB activation by TNFa is analyzed. [less ▲]

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See detailUse of high performance computing in animal breeding
Vandenplas, Jérémie ULg; Gengler, Nicolas ULg

Poster (2014, August 28)

High-perfomance computing facilities proposing shared-memory and distributed-memory multiprocessors are becoming available. With those clusters, parallel computing could lead to increased performances and ... [more ▼]

High-perfomance computing facilities proposing shared-memory and distributed-memory multiprocessors are becoming available. With those clusters, parallel computing could lead to increased performances and problem sizes. However, to our knowledge and especially for variance components estimations, most software available in animal breeding, based on sparse matrices computations, do not allow parallel computing and are limited by memory accessible by the central processing unit, or allow parallel computing only for options with dense matrices computations, which limits anyway problem sizes due to storage of dense matrices. The aim was to propose simple and effective modifications for the BLUPF90 family of programs to reduce computing time with consideration of required memory. Modifications were based on academic free packages proposing solver and sparse inversion for sparse symmetric indefinite linear systems. First, modifications concerned the sparse inversion subroutine implemented in the package FSPAK. Rearrangements of 'do' loops to allow optimizations of computer operations by some compilers and addition of OpenMP directives were performed. The ordering operation was modified to more easily compare a multiple minimum degree algorithm (MMD; implemented in FSPAK) and a multilevel nested dissection algorithm (implemented in METIS 4.0.3). Second, the package PARDISO Version 5.0.0 was used instead of FSPAK. This package proposes in particular a parallel solver and sparse inversion on shared-memory multiprocessors. Modified FSPAK and PARDISO were compared to original FSPAK using MMD through REMLF90. Different models, such as univariate or bivariate (random regressions) test-day animal and single-step genomic models, were tested. All jobs were run 5 times. With an appropriate ordering algorithm, speedup for each REMLF90 iteration were up to 7.5 for modified FSPAK and up to 22.8 for PARDISO with 2 threads. With 4 threads, speedup increased to 8.3 and 32.5, respectively. [less ▲]

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Peer Reviewed
See detailA post-mortem study of physiopathological characteristics of genital tracts of culled dairy cows in South Vietnam.
Nguyen Kien, Cuong; Okouyi, Marcel; Hanzen, Christian ULg

Poster (2014, August 28)

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See detailGene Regulatory Network Inference via Conditional Inference Trees and Forests
Bessonov, Kyrylo ULg

Poster (2014, August 28)

Trees are classical data structures allowing effectively classifying and predicting responses. Due to versatility and high performance in classification and prediction, there exist plenty of tree-based ... [more ▼]

Trees are classical data structures allowing effectively classifying and predicting responses. Due to versatility and high performance in classification and prediction, there exist plenty of tree-based methods including popular Conditional Inference Tree (CIT) and Forests (CIF), Random Forests (RF), Randomized Trees (RT), randomized C4.5, etc. In this work we assessed the performance of CIT and CIF methods in correct gene regulatory network (GRN) prediction from expression data by using reference golden standard built from real transcriptional regulatory network of E. coli. The synthetic microarray expression data was obtained from DREAM4 challenge. The performance of each network inference method was assessed via Area Under Receiver Operating Characteristic (AUROC) and Area Under Precision Recall (AUPR) metrics. Our preliminary results show that CIT and CIF successfully predict directed GRNs at acceptable performance rates although not optimal (the best AUROC at 0.68 and AUPR at 0.13 for CIF and the best AUROC at 0.58 and AUPR at 0.18 for CIT). Surprisingly by using the current aggregation scheme of feature importance that prefers features with the highest number of observations, a single CIT was a better performer compared to CIFs in all 5 networks. Nevertheless, the CIFs showed an overall 10% improvement in AUROC. A single CIT has 24% and CIFs have 27% lower overall performance compared to the best performer of DREAM4 Challenge based on cumulative areas of PR and ROC curves. We plan to test other feature importance aggregation techniques in a single tree and in tree ensembles in order to outperform the top DREAM4 algorithms. In addition the effects of expression data standardization to unit variance will be presented. In future, the developed CIF framework will be used to perform data integration analysis of multi-omics datasets. [less ▲]

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See detailDetection of wheat root and straw in soil by use of Near Infrared hyperspectral imaging system and Partial Least Square discriminant analysis
Eylenbosch, Damien ULg; Fernández Pierna, Juan Antonio; Baeten, Vincent et al

Poster (2014, August 26)

Monitoring of root systems development and crop residues decomposition is only possible if these constituents can be discriminated from soil and quantified. In this work, Near Infrared (NIR) combined with ... [more ▼]

Monitoring of root systems development and crop residues decomposition is only possible if these constituents can be discriminated from soil and quantified. In this work, Near Infrared (NIR) combined with Hyperspectral Imaging (HSI) and Partial Least Square Discriminant Analysis (PLS-DA) is proposed as a new rapid and reliable method to discriminate soil, roots and straws. NIR-HSI provides simultaneously spectral and spatial information and PLS-DA allows discrimination between classes based on spectra of each pixel linked to chemical nature of sample constituents on the image. [less ▲]

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See detailCreation of universal MIR calibration by standardization of milk spectra: example of fatty acids
Grelet, Clément; Fernandez Pierna, Juan; Soyeurt, Hélène ULg et al

Poster (2014, August 25)

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Peer Reviewed
See detailModeling of the cyclic lipodepsipeptide Pseudodesmin A self-assembly through molecular dynamic simulations
Crowet, Jean-Marc ULg; Sinnaeve, Davy; Fehér, Krisztina et al

Poster (2014, August 21)

The self-assembly of short peptides into supramolecular structures represents an active field of research with potential applications, ranging from material sciences to medicine. Pseudodesmine A is a ... [more ▼]

The self-assembly of short peptides into supramolecular structures represents an active field of research with potential applications, ranging from material sciences to medicine. Pseudodesmine A is a cyclic lipodepsipeptide of nine residues which presents a moderate antibacterial activity and whose structure has been resolved by X-ray and NMR. In acetonitrile, Pseudodesmine A is monomeric while in chloroform, it has the same structure but assembles in a supramolecular complex. This structure could associate with membranes and be responsible for the biological activity of the peptide. Comparison of NMR data in the two solvents has given indications on the intermolecular contacts that arise in chloroform and a model for the self-association was proposed. To study in more details this assembly, molecular dynamics simulations have been carried on. The resultswere compared with detailed information given by NMR, regarding the dimensions of the assembly and the orientation of the individual peptide building blocks inside the supramolecular assembly. In acetonitrile, the simulations show that the peptide has transient interactions while in chloroform, interactions between monomers are always observed. In agreement with NMR, these interactions arise mainly between the backbone protons of the LEU1 and the GLN2, the GLN2 sidechain and the loop located on the opposite end of the monomer structure. From 10 simulations of dimerization, hydrogen bonds were followed and specific interaction patterns were identified regarding the hydrogen bonds formed. Peptide interactions are mainly described by 13 interaction patterns characterized by 2 to 4 hydrogen bonds. In dimers, the peptides can have a linear, a perpendicular or a side by side configuration. From the linear dimer, it is possible to reconstruct filaments and, by combining a linear and a lateral dimer, it is possible to build fibrils with multifilaments, as found in the NMR-derived model. Two self-consistent supramolecular models can be built from dimers and they present a very good correlation with NMR data regarding the supramolecular organization. Besides, the perpendicular dimer can gives peptide rings that can also explain the potential ability of this peptide to form ion pores in membranes. [less ▲]

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See detailEarthquake imprints on 400 years of marine sedimentation in the western Gulf of Corinth, Greece
Beckers, Arnaud ULg; Hubert, Aurelia ULg; Beck, Christian et al

Poster (2014, August 18)

The Corinth rift is one of the fastest spreading rifts on Earth. In the western tip of the Rift, no major historical earthquake (Mw≥6) is known for the last 300 yrs, while the geodetic extension rate is ... [more ▼]

The Corinth rift is one of the fastest spreading rifts on Earth. In the western tip of the Rift, no major historical earthquake (Mw≥6) is known for the last 300 yrs, while the geodetic extension rate is the highest of the whole Corinth Rift. The question of seismic hazard is consequently particularly relevant. In this framework, we investigated the offshore sediments in order to look for sedimentary signature of past earthquakes. 12 short gravity cores have been retrieved in different environments: two shelves (40 and 100 m deep), one sub-basin (180 m deep) and the deep Gulf axis (330 m deep). The cores are 0.5 to 0.85 m long, permitting to analyze up to 400 yrs of sedimentation. Several sedimentological analyses have been performed: magnetic susceptibility, grain-size, XRF, ASM. Chronology is based on 137Cs and 210Pb decay. In parallel, an in-depth analysis of existing and newly found documents has been done to re-interpret macroseismic intensity fields of historical earthquakes and to build an updated earthquake catalogue for the area. These new data allowed us to estimate a macroseismic intensity threshold for submarine slope failures in the area, based on 16 reported events. Sedimentary events have been identified in all cores. On the first shelf, despite a visually homogenous, silty, sedimentation, 3 events have been highlighted by high resolution grain-size analysis and 210Pb decay profile’s disturbances. The upper one could be a back-wash flow tsunami deposit. On the second shelf, 4 high-concentration density flow deposits occurred with a recurrence time of ~58 yrs. In the canyon and in the sub-basin, sandy turbidites occurred with recurrence times of ~26 and ~56 years respectively. The possible seismic origin of these deposits is discussed based on their sedimentary characteristics and the macroseismic intensities assessed for the sediments source areas for each core location. [less ▲]

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See detailAnalysis of spray retention on a 3D black-grass plant model as a function of spray nozzle and formulation using a process-driven approach
Massinon, Mathieu ULg; Ouled Taleb Salah, Sofiene ULg; Dumont, Benjamin ULg et al

Poster (2014, August 13)

The efficiency of spray application of foliar plant protection products can be variable because of the different amount of spray solution intercepted and retained by leaves. On one hand, the spray ... [more ▼]

The efficiency of spray application of foliar plant protection products can be variable because of the different amount of spray solution intercepted and retained by leaves. On one hand, the spray interception by plants is affected by nozzle kind, size and operating pressure as well as by the plant architecture. On the other hand, the spray retention is affected by application parameters resulting from droplet size and velocity as well as spray mixture physicochemical properties. In this paper, spray retention is tackled with a physical approach at the droplet scale. The methodology deals with high-speed imaging to characterize droplet impacts; adhesion, rebound or shatter on small excised leaf areas and the spray granulometry. The 3D reconstruction of a black-grass plant involves a structured light technique. The overall spray retention was determined by using an interception algorithm combined with a process-driven retention approach as a function of the spray nozzle and formulation used. The interception model allowed determining the spray retention by a single plant and discriminating application parameters by explaining the variability resulting from various droplet size distributions intercepted by single plant. Such a model can be used to increase the understanding of interactions between spray techniques and plant architectures. [less ▲]

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See detailExperimental study of the magnetic shielding performances of a Bi2223 tube closed by a Bi2223 cap.
Wera, Laurent ULg; Fagnard, Jean-François ULg; Hogan, Kevin ULg et al

Poster (2014, August 12)

A superconducting tube can be used as an efficient magnetic shield. However, the shielding factor (defined as the ratio between the applied magnetic induction and the magnetic induction measured inside ... [more ▼]

A superconducting tube can be used as an efficient magnetic shield. However, the shielding factor (defined as the ratio between the applied magnetic induction and the magnetic induction measured inside the tube) decreases towards tube extremities because of the field penetration through the open ends of the tube. To improve the performances at tube extremities, the tube should be closed. This can be achieved by using a superconducting vessel or by closing both extremities with a cap. The purpose of the present work is to study experimentally the shielding performances of a Bi2223 tube closed by a superconducting Bi2223 cap. The cap is a circular plate with a diameter equal to the outer diameter of the tube and there is no superconducting joint between the cap and the tube. Our interest is to characterize the effect of the cap on the shielding factor distribution along the tube axis when only one extremity of the tube is closed. We also study the effect of the gap size between the cap and the tube in axial configuration. Finally, a tube closed at its both ends is also characterized. All experiments are carried out at 77K. The tube is subjected to a quasi-static (“DC”) uniform magnetic field. A Hall probe measures the three components of the local magnetic induction along the axis of the tube as a function of the applied magnetic induction. Results show that the shielding performances in the axial configuration are highly improved at the closed extremity as the cap reduces the penetration through the open end. The shielding factor distribution along the tube axis is affected by the presence of the cap. For an open tube, the shielding factor is maximum near the center and decreases towards both extremities. For the tube closed at one extremity, the shielding factor is maximum at the closed extremity and decreases towards the center. Moreover, the shielding factor distribution between the tube center and the open extremity is not affected by the presence of the cap. The experimental results show that, a small gap between the tube and the cap, which can be necessary for applications, does not strongly affect the magnetic shielding performances of the assembly. [less ▲]

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See detailMagnetic shielding properties of a bulk Bi-2223 superconducting hollow cylinder subjected to an inhomogeneous magnetic field
Hogan, Kevin ULg; Wera, Laurent ULg; Fagnard, Jean-François ULg et al

Poster (2014, August 12)

Bulk superconducting materials are well suited for magnetic shielding applications. At low frequencies, the performances of superconductors are higher than those of conventional ferromagnetic materials ... [more ▼]

Bulk superconducting materials are well suited for magnetic shielding applications. At low frequencies, the performances of superconductors are higher than those of conventional ferromagnetic materials. In shielding applications, two situations may be encountered. The first one corresponds to the case where the screen has to shield a volume from the magnetic field in its environment; this corresponds to an “immunity” problem. In the second situation, the screen has to prevent the magnetic field generated by an electronic device from perturbing its environment; this is an “emission” problem. So far, superconducting screens have been extensively studied in “immunity” and were subjected to uniform magnetic fields. In “emission”, the magnetic field is no longer uniform because a local magnetic source has to be placed inside the screen. In this work, we have studied experimentally at 77K the magnetic flux penetration in a Bi-2223 superconducting hollow cylinder subjected to a non-uniform quasi-static magnetic field generated by a small coil placed inside the sample. Two configurations were investigated: axial and transverse; corresponding respectively to the situation where the axis of the coil is coaxial or perpendicular to the axis of tube. We also investigate the influence of the sweep rate of the magnetic field on the magnetic shielding performances. Planar and circular (i.e. at constant distance of the tube) mappings of the magnetic field at proximity of the external surface of the tube were obtained thanks to a bespoke experimental setup using a three axes miniature Hall probe. It was observed that the three components of the magnetic field measured outside are affected differently by the superconducting screen. A simple one-dimensional model based on the conservation of magnetic flux and the Bean model was developed for the axial configuration. It was found to be in accordance with experimental data. It allows one to predict the maximal magnetic flux that can be generated inside the coil before the tube is fully penetrated and a magnetic field is measured outside the tube. Finally, it was observed that the inner surface of the tube is subjected to a magnetic field higher than the one at the same place without the tube. This concentration phenomenon arises because of the diamagnetic behaviour of the superconductor. [less ▲]

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See detailThe Neurocognitive Underpinnings of Multitasking Capacities in Persons Diagnosed with Schizophrenia
Laloyaux, Julien ULg; Van der Linden, Martial ULg; Levaux, Marie-Noëlle ULg et al

Poster (2014, August 10)

Difficulties in everyday life activities are core features of persons diagnosed with schizophrenia, and in particular during multitasking activities. Multitasking refers to activities where the person has ... [more ▼]

Difficulties in everyday life activities are core features of persons diagnosed with schizophrenia, and in particular during multitasking activities. Multitasking refers to activities where the person has to: carry out and alternate between different tasks that vary in terms of priority, difficulty and duration; define the tasks’ targets; and where the person is faced with unexpected problems during the realization of these tasks (Burgess, 2000). However, the neurocognitive underpinnings of multitasking have never been explored in schizophrenia. Further, only two cognitive models exist in the literature, based on a student sample (Logie et al., 2011) and a neurological sample (Burgess et al., 2000). Both of these models suggest three primary constructs including Memory, Planning and Intent. However, there are several limitations related to the way multitasking was evaluated in these studies. We thus developed a computerized real-life activity task designed to take into account the multitasking nature of certain everyday life activities where participants are required to prepare a room for a meeting – the Computerized Meeting Preparation Task (CMPT). Using this new task, and based on previous studies (Burgess et al., 2000; Logie et al., 2011), the aim of the present study was to evaluate a new cognitive model of multitasking ability and that takes into account certain cognitive processes that are not integrated in existing models. Fifty-seven individuals diagnosed with schizophrenia and 41 matched healthy controls completed the CMPT. Participants were also evaluated with a battery of cognitive tests. The results suggest that the CMPT has a good sensitivity. Moreover, structural equation modelling confirmed the three underlying constructs of multitasking (Memory, Planning and Intent) which are underpinned by several cognitive functions and multitasking aspects. Taken together, this new cognitive model and the CMPT could be a good basis for cognitive intervention on multitasking. [less ▲]

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See detailPerformance on a Computerized Shopping Task in Bipolar Disorder and Alcohol Dependency
Laloyaux, Julien ULg; Michel, Céline; Pellegrini, Nadia et al

Poster (2014, August 10)

Persons diagnosed with bipolar disorder and alcohol dependency are frequently subject to cognitive impairments and encounter difficulties during everyday life activities. However, little is known how ... [more ▼]

Persons diagnosed with bipolar disorder and alcohol dependency are frequently subject to cognitive impairments and encounter difficulties during everyday life activities. However, little is known how these deficits interact in real life. Moreover, previous studies have primarily used questionnaires or observational methods to assess everyday life functioning, both of which contain a number of limits. In order to address some of these limits, we developed a computerized real-life activity task, in particular, a shopping task where participants are required to shop for a list of 8 grocery store items in a virtual supermarket. Twenty individuals diagnosed with alcoholic dependence and 21 patients diagnosed with bipolar disorder were compared with healthy controls (20 and 21, respectively), matched for age, sex and educational level. All participants completed the shopping task, and both clinical groups were evaluated with an extensive battery of cognitive tests (assessing executive functioning, attention, processing speed and memory), clinical scales and a measure of real world functioning. Results showed that, for both clinical groups, performance on the computerized shopping task significantly differentiated patients and healthy controls for a number of variables, especially total time to complete the shopping task. Performances on shopping task variables, in both clinical groups, were also significantly correlated with cognitive tests measuring processing speed, episodic memory, cognitive flexibility and inhibition. Finally, performances on the computerized shopping task were significantly correlated with real world functioning in both patient groups. These findings suggest that the computerized task used in the present study provides a valid indication of the level of real world functioning for these clinical populations, and therefore may be viewed as a valuable instrument in both an evaluation and remediation context. [less ▲]

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See detailEnforcement of accounting standards and their impact on the consistent application of IFRS
Yammine, Mira ULg; Olivier, Henri ULg

Poster (2014, August 06)

The objective of this study is to determine the impact of enforcement of accounting standards on earnings management. In line with previous studies, we have selected timely loss recognition, small ... [more ▼]

The objective of this study is to determine the impact of enforcement of accounting standards on earnings management. In line with previous studies, we have selected timely loss recognition, small positive income, and earnings variability as proxies for earnings management. In order to reach our objective, we have defined our enforcement indexes using a survey on enforcement activities. The survey was prepared and sent directly to the institution oversight bodies that have an enforcement power on the application of IFRS in the studied countries. We find that the existence of an effective enforcement body that supervises the implementation and application of IFRS has reduced the frequency of large losses recognition, and have some impact in some situations on small positive income and earnings variability. Other tests are performed on specific enforcement activities such as pre-clearance and the sanctions imposed by the judicial system in a country. The study opens the door for additional investigations in the area of enforcement activities. [less ▲]

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See detailDevelopment of entomopathogenic fungi in mosquito control: which kind of production for which efficiency?
Bawin, Thomas ULg; Delvigne, Frank ULg; Francis, Frédéric ULg

Poster (2014, August 06)

Mosquitoes (Diptera: Culicidae) are zoonotic vectors responsible for numerous infectious diseases of medical and veterinary importance such as filariasis, malaria and encephalitis. As part of an ... [more ▼]

Mosquitoes (Diptera: Culicidae) are zoonotic vectors responsible for numerous infectious diseases of medical and veterinary importance such as filariasis, malaria and encephalitis. As part of an integrated vector control, entomopathogenic fungi could be developed as biopesticides in two ways: spores and metabolites recognized as effective virulence factors. Solid-state fermentation enhances spore production and induces the secretion of metabolites quantitatively and qualitatively different from submerged fermentation, which impairs fungal metabolic efficiency. In this context, we showed high spore productivity of solid-state media based on agro-industrial substrates as wheat bran. Spores remained pathogenic, as revealed by classical toxicity tests and electron microscopy. However, the absence of free water makes culture parameter variations difficult to control in large-scale. Recently, we performed a bioreactor design intended for simultaneous spore and metabolite production, combining the technological advantages of submerged and solid-state fermentations. Biofilm fermentation (i.e. growth of fungal biomass on an inert support immerged in a nutrient medium) is a tremendous production system favouring the secretion of insecticidal metabolites in the liquid medium as we showed recently. This is also an interesting tool to provide an overview of the complexity of the metabolic pathways involved in the regulation of extracellular metabolites secretion because corresponding genes are reported to be differentially expressed from classical fermentation systems. Researches in vector control are currently intensified. In this context, the identification of genes and metabolites specifically expressed during biofilm fermentation will help to develop new technologies related both to the design of bioreactor and the production of insecticidal proteins. [less ▲]

Detailed reference viewed: 42 (4 ULg)
See detailEx-situ’ conservation of Antarctic cyanobacteria : a culture collection to explore diversity and bioactivity
Wilmotte, Annick ULg; Renard, Marine ULg; Kleinteich, J et al

Poster (2014, August)

Cyanobacteria appear as the dominant phototrophs in Antarctic terrestrial and freshwater ecosystems. Since 2011, the Belgian Science Policy Office has funded the BCCM/ULC public collection of (sub)polar ... [more ▼]

Cyanobacteria appear as the dominant phototrophs in Antarctic terrestrial and freshwater ecosystems. Since 2011, the Belgian Science Policy Office has funded the BCCM/ULC public collection of (sub)polar cyanobacteria. It is currently holding 102 Antarctic cyanobacterial strains and the catalogue is available on http://bccm.belspo.be/db/ulc_search_form.php. A Quality Management System was implemented and an ISO9001 certificate was obtained for the public deposition and distribution of strains. The strains are kept as living cultures, and their cryopreservation is in progress. The Antarctic cyanobacterial strains were isolated from samples of the three main biogeographic provinces. The purpose of this public collection is to gather a representative portion of the cyanobacterial diversity with different ecological origins (limnetic microbial mats, soil crusts, cryoconites, endoliths, etc.) and make it available for researchers to study the diversity, evolution, adaptations to the environmental conditions, and genomic make-up. Three cyanobacterial orders are represented: Chroococcales, Oscillatoriales and Nostocales. This is particularly important in view of the emerging use of metagenomic approaches on environmental samples, where the comparisons with the genome sequences from well-defined strains is very useful. They could also serve as references for compounds such as fatty acids and pigments. In addition, cyanobacteria produce a range of secondary metabolites (e.g. alkaloides, cyclic and linear peptides, polyketides) with different bioactive potential (e.g. antibiotic, antiviral, anticancer, cytotoxic, genotoxic). Bioassays have shown antifungal activities of the cell extracts of strains Plectolyngbya hodgsonii ULC009 and Phormidium priestleyi ULC026. Due to the geographic isolation and the strong environmental stressors of the habitat, the exploration of these metabolites in Antarctic cyanobacterial strains seems especially promising for biotechnology or biomedical applications. In summary, the BCCM/ULC public collection could serve as a general reference for Antarctic cyanobacteria with multiple applications, as well as a resource for novel bioactive compounds. [less ▲]

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See detailWhich P inputs are compatible with a sustainable agriculture at short and long-term?
Renneson, Malorie ULg; Dufey, Joseph; Roisin, Christian et al

Poster (2014, August)

During the past 20 years, there has been a constant reduction in mineral fertilizer use due to price increases and environmental concerns. These changes can lead to a decrease in soil P content, which is ... [more ▼]

During the past 20 years, there has been a constant reduction in mineral fertilizer use due to price increases and environmental concerns. These changes can lead to a decrease in soil P content, which is already observed in some regions in Wallonia. Some new issues are now emerging. Is current cropping systems compatible with yield maintenance? Do organic fertilizers have a similar effect than mineral fertilizers? To answer to these questions, a short-term experiment in controlled conditions and 2 long-term experimental plots were studied. The short-term experiment permitted to study the kinetics of P after an input and differences between fertilizer types, whereas the long-term experiments studied 3 levels of P and K input and different organic compounds. Although an evolution of P content was observed, no difference of yield was found before about 20 years. However, after 47 years, available P levels were considered as low in zero P-input plots and attention must now be focused on these parcels. Zero P-input caused a mean yield decrease of 7%, while a double input increased yield by 2% in comparison to plots with input corresponding to crop export. Thus the zero P-input option is rarely economically profitable in the long-term and providing double the amount of P removed is never financially sustainable. Finally, no difference of P content was observed between organic and mineral fertilizers, except for manure which engendered a higher P content. In conclusion, organic and inorganic fertilizers had a relatively similar effect and overlooking P fertilizer is possible in the short-term but P content has to be followed at the long-term, although yield loss was limited. [less ▲]

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See detailMultidisciplinary approaches and fractionations to study lower termite symbiotic system and ligno-cellulose digestion
Bauwens, Julien ULg; Brasseur, Catherine ULg; Tarayre, Cédric ULg et al

Poster (2014, August)

Wood-feeding termites are a considerable source of enzymes active on ligno-cellulosic compounds. These enzymes are produced by the termite host and some representatives of its symbiotic microbial ... [more ▼]

Wood-feeding termites are a considerable source of enzymes active on ligno-cellulosic compounds. These enzymes are produced by the termite host and some representatives of its symbiotic microbial community, and are of particular interest in regard second generation biofuel. However, the complexity of microbial interactions renders micro-organisms isolation very difficult. Culture-independent methods permitted to gather a large amount of data and to understand a little more the role of each microbial population, particularly the prokaryotes. Proteomics allows working on the final product of gene expression, and corresponds more to the real operation of the digestive system. In order to investigate such a complex system, it is necessary to use multidisciplinary approaches and to fractionate this system. Zymography or affinity chromatography are used in parallel of routine proteomics techniques such as two-dimensional gel electrophoresis associated to MALDI-TOF mass spectrometry and nano-LC ESI-MS/MS. We used an artificial-diet based rearing to induce changes in microbial population balance. We performed preliminary assay to investigate the glycosylated proteome in the hindgut of a lower termite, using Multi-Lectin Affinity Chromatography (M-LAC) and enzymatic activity of harvested fractions was assessed on cellulosic substrates. [less ▲]

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See detailIdentification of lectins as virus competitors in aphid vectors: from fundamental to applied approaches
Bosquée, Emilie ULg; Chen, Ju Lian; Yong, Liu et al

Poster (2014, August)

Aphids remain difficult virus vectors to be controlled in many crops. Within this context of biological control against aphids and investigation on virus transmission (both non persistent Potato virus Y ... [more ▼]

Aphids remain difficult virus vectors to be controlled in many crops. Within this context of biological control against aphids and investigation on virus transmission (both non persistent Potato virus Y (PVY) and Cucumber Mosaic Virus (CMV) and persistent Barley Yellow Dwarf Virus, the use of lectins was developed. Indeed, the effects of lectin binding to glycoprotein aphid receptors on virus transmission were tested in laboratory via the use of artificial diets using different virus models. Differential effects on virus transmission efficiency were determined. By example, a strong interference between GNA and PVY was observed. In consequence, the lectin was considered as promising proteins and could be potential competitors to virus. For further research, a fast protein liquid chromatography was performed to identify aphid proteins related to binding to efficient lectin competitors. Moreover, to detect involved proteins in aphids, two-dimensional gel electrophoresis approach coupled to mass spectrometry was developped to identify the glycosylated proteins determining virus transmission efficiency. Use of lectins for both fundamental and applied approaches were discussed to investigate aphid – virus interactions [less ▲]

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See detailUnderstanding of the diversity of earthquake turbiditic flows in a single lake: the case of the Lake Hazar on the East Anatolian Fault
Lamair, Laura ULg; Hage, Sophie ULg; Hubert, Aurelia ULg et al

Poster (2014, August)

The East Anatolian Fault (EAF) is a major left-lateral strike-slip fault accommodating with the conjugate North Anatolian Fault the westward extrusion of the Anatolian Plate away from the Arabia-Eurasia ... [more ▼]

The East Anatolian Fault (EAF) is a major left-lateral strike-slip fault accommodating with the conjugate North Anatolian Fault the westward extrusion of the Anatolian Plate away from the Arabia-Eurasia collision zone. The East Anatolian Fault ruptured over most of its length during the 19th century in a series of magnitude ~7 earthquakes. During the 20th century this fault was less active with only two events of magnitude greater than 6. This absence of large earthquakes has resulted in relatively little attention being paid to the East Anatolian Fault compared to the North Anatolian Fault, which has ruptured during the last century in several earthquakes of Ms~7. To constrain the seismic history of the East Anatolian Fault in its central part, we focus on the Hazar Lake, occupying a 20 km long pull-apart basin. Short cores and long sedimentary cores were collected at three different sites to retrieve a paleoseismic record. Small correlative coarse-grained sedimentary events are identified in all cores. The age of the events is inferred combining radiocarbon and radionuclide (137 Cs and 210Pb) dating. We present here detailed analyses of three sedimentary events assigned respectively to the historical earthquakes occurring in 1789, 1513-1514, 1285. The source of the sedimentary events is different at the three sites. We combine X-ray imagery, magnetic susceptibility, grain-size and XRF measurements with thin section analysis to investigate the nature of sedimentary events. The analyses show first that the three sedimentary events are different. The magnitude of the terrigenous signal varies significantly. Second the correlative events have a different expression at the three sites. So each site has a different and specific sensitivity. In particular, an individual event can be composed of several coarse-grained sub-events of different magnitude with a time lapse in between greater than a week. The latter is reveals by the presence of bioturbation in particular by chironomids in individual thin sand layers. Thin section also shows that subevents are gradded. Each coarse-grained layer is thus a separated turbiditic flow. The site with the highest sensitivity is the one located near the near-shore steep submarine southern slopes overhanged by the steep subaerial slopes of the Hazar Mountains. The rivers draining the Hazar Mountains are ephemeral and provide a restricted sedimentary supply. In addition, seismic reflection data show that the submarine slopes do not to accumulate a significant sedimentary load. However on these steep slopes, an earthquake intensity of 6 or less is enough to trigger a slope failure and the associated turbiditic flow. We conclude that the different sub-events at this site may record a complete earthquake sequence, i.e the main-shock and its foreshocks and aftershocks. [less ▲]

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See detailIdentification and comparison of proteome patterns of English Grain Aphids on resistant and susceptible wheat
Bosquée, Emilie ULg; Barrios San Martin, Joceline; C. RAMÍREZ, Claudio et al

Poster (2014, August)

Some varieties of wheat are resistant to some aphid clones of the English Grain Aphid (Sitobion avenae). This study used 2D-DIGE coupled with protein identification by Maldi-Tof-MS to compare the proteome ... [more ▼]

Some varieties of wheat are resistant to some aphid clones of the English Grain Aphid (Sitobion avenae). This study used 2D-DIGE coupled with protein identification by Maldi-Tof-MS to compare the proteome patterns of English Grain Aphids on resistant (Llareta) and susceptible (Huayún) wheat lines. Aphids were exposed to wheat during 2 weeks (short term: ST) and 4 weeks (long term: LT). Four treatments were compared: Llareta-ST, Llareta-LT, Huayún-ST, Huayún-LT. Experiment was conducted using different Sitobion avenae clones whose symbionts were previously characterized. Results showed that aphids had low performance on resistant plants. Seventy-two protein spots showed significant quantitative differences among the four treatment groups. Proteomic approach will allow a better understanding of interaction mechanisms between aphids and wheat. [less ▲]

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See detailX-raying the winds of the evolved massive binary HDE228766
Rauw, Grégor ULg; Mahy, Laurent; Nazé, Yaël ULg et al

Poster (2014, August)

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See detailAphid - symbiont interactions : multitrophic "omic" approaches to investigate multitrophic interactions
Bosquée, Emilie ULg; Bauwens, Julien ULg; Mazzucchelli, Gabriel ULg et al

Poster (2014, August)

« Omics » found recent developments due to significant improvement and availability of both separation and identification methods. For proteomics, functional information’s linked to the studied proteins ... [more ▼]

« Omics » found recent developments due to significant improvement and availability of both separation and identification methods. For proteomics, functional information’s linked to the studied proteins was brought when compared to genomic approach. For these reasons, a panel of tools is available to determine the proteome patterns related to differential adaptation of insects to cope with plant defence mechanisms or to transmit virus. The adaptation and metabolic changes of aphids in relation to host plants focusing on the role of the bacterial endosymbionts was investigated. Use of artificial diet including diverse antibiotics but also the comparison of proteomes related to whole aphid and respective purified bacterial symbionts were studied to identify the respective origin and function of proteins constituting the studied proteomes. Diverse methods including 2D-DIGE, liquid chromatography coupled with mass spectrometry and data bank investigations were developed. From the proteome investigation, characterisation of good and bad virus vectors was also performed in different aphid - plant - virus models. Particular proteins of interest were selected. This broad proteomic approach will be discussed as an interesting and reliable tool to study the biologically involved proteins from aphids in response to several environmental changes [less ▲]

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See detailCT FEATURES OF A LACRIMAL GLAND TUMOR IN A DOG
Etienne, Anne-Laure ULg; Grauwels, Magda ULg; Storms, Goedele ULg et al

Poster (2014, August)

Background: In the dog, neoplasms of the lacrimal gland are rare. Lacrimal cysts were also reported. Computed tomography (CT) scan findings of these lacrimal gland abnormalities have not been described in ... [more ▼]

Background: In the dog, neoplasms of the lacrimal gland are rare. Lacrimal cysts were also reported. Computed tomography (CT) scan findings of these lacrimal gland abnormalities have not been described in dogs. Purpose: The present report describes clinical and CT features of a lacrimal gland tumor in a dog. Methods: A 3,5 year old female intact Leonberger with a good general health status was presented with a progressive swelling at the level of the supero-temporal area of the left upper eyelid and of the bulbar conjunctiva since 3 weeks. Ocular examination revealed a slight enophthalmia and a ventronasal strabismus, the presence of a firm mass in the upper eyelid which was anteriorly well circumscribed and extending posteriorly between the globe and the orbital ligament. Findings: A CT scan pre- and post- contrast studies of the head were performed. A 3 cm hypoattenuating (+/- 10 HU) ovoid mass was observed dorsolateral to the indented left globe. This mass was well circumscribed by an unevenly thick irregular soft tissue- attenuating wall (50HU), which was strongly contrast-enhanced (150HU) and measured about 2 to 10mm in thickness. The left globe was displaced caudoventromedially. No adjacent bone lesion, or foreign body was observed. No normal left lacrimal gland was observed. These findings were suggestive of an abscess or an orbital tumor with a necrotic/cystic center; a lacrimal cyst was considered less likely because of the unevenness and the thickness of the wall. Complete surgical ablation was done by a modified lateral orbitotomy. Histopathology revealed a mixed benign tumor of the lacrimal gland and a lymphocytic necrotic adenitis. Six months postoperatively no recurrence is noted and the tear production is 15mm/min. Conclusion: The lacrimal gland is located dorsolateral to the globe and produces tears. In human medicine, a wide range of lacrimal gland pathologies were described and assessed by computed imaging techniques. Pleomorphic adenomas (mixed benign tumor) could reveal irregular bone erosion and could undergo malignant transformation. In dogs, lacrimal cysts were described as thin walled structures.4 Only few articles reported lacrimal gland tumor. To the authors knowledge, CT findings of a lacrimal gland tumor have not been described previously. In conclusion, lacrimal gland tumor should be included in the differential diagnosis of a firm ovoid cystic/necrotic mass dorsolateral to the orbit. [less ▲]

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See detailInfluence of aging technique and muscle on physicochemical stability and antioxidant capacity of high-oxygen atmosphere packed beef
Didimo Imazaki, Pedro Henrique ULg; Tahiri, Assia ULg; Thimister, Jacqueline ULg et al

Poster (2014, August)

The aim of this study was to compare the effect of aging technique (wet-aging vs. carcass-aging), muscle (longissimus dorsi vs. rectus femoris) and previous vacuum storage time on color and lipid ... [more ▼]

The aim of this study was to compare the effect of aging technique (wet-aging vs. carcass-aging), muscle (longissimus dorsi vs. rectus femoris) and previous vacuum storage time on color and lipid stability of beef packaged in high-oxygen atmosphere. After a seven-day wet- or carcass-aging step, longissimus dorsi and rectus femoris muscle cuts from 4 Belgian Blue cows were vacuum packaged and stored at −1 °C for up to 28 days. At different times, part of these samples was repackaged under modified atmosphere – 70 % O2:30 % CO2 –, and stored during 7 days at +4 °C. The following parameters were evaluated at different intervals: color (CIE L*a*b*), metmyoglobin %, lipid oxidation (TBARS), antioxidant enzyme activities (catalase, glutathione peroxidase and superoxide dismutase), alpha-tocopherol and fat content. The sensitivity of modified atmosphere repacked meat cuts to oxidation was influenced by the conditions of the previous aging period (wet > carcass conditions), muscle (rectus femoris > longissimus dorsi) and length of the vacuum storage. Oxidation stability could be associated with catalase activity, and no association could be established with the alpha-tocopherol content. [less ▲]

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See detailUnveiling biogeographic patterns of Antarctic cyanobacteria by 454 pyrosequencing
Wilmotte, Annick ULg; Stelmach Pessi, Igor ULg; De Carvalho, Pedro et al

Poster (2014, August)

Cyanobacteria are often considered as the dominant phototrophs in Antarctic lacustrine environments, primarily occurring in benthic or floating microbial mat communities. Previous studies have indicated ... [more ▼]

Cyanobacteria are often considered as the dominant phototrophs in Antarctic lacustrine environments, primarily occurring in benthic or floating microbial mat communities. Previous studies have indicated the presence of endemic cyanobacteria in the Antarctic Realm, but the extent and patterns of cyanobacterial bioregionalisation, if any, is still largely unknown. Therefore, our objective is to assess the cyanobacterial diversity in Antarctic lacustrine microbial mats using 454 pyrosequencing, in order to determine if cyanobacterial biogeographic patterns are similar to those observed for multicellular organisms. This will be useful also as baseline data, for later comparisons and assessments of the impact of global change. [less ▲]

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See detailA First Look at the Nonadiabatic Properties of Pulsating Accreting White Dwarfs of the GW Lib Type
Van Grootel, Valérie ULg; Fontaine, G.; Brassard, P. et al

Poster (2014, August)

We present results of a detailed stability survey of the pulsation properties of accreting white dwarfs of the GW Lib type. This is based on several state-of-the- art white dwarf evolutionary sequences ... [more ▼]

We present results of a detailed stability survey of the pulsation properties of accreting white dwarfs of the GW Lib type. This is based on several state-of-the- art white dwarf evolutionary sequences with varying envelope compositions, from pure hydrogen to pure helium. Using the same tools as in Van Grootel et al. (2013), where we have presented the first consistent view of the ZZ Ceti instability strip, we have mapped the GW Lib instability strip over the effective temperature-surface gravity plane, and as a function of envelope composition. We find that the location of the GW Lib instability domain is a strong and continuous function of the assumed envelope composition. We can accomodate all of the known GW Lib pulsators in various strips according to their atmospheric compositions. [less ▲]

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See detailX-ray emission from magnetic massive stars
Nazé, Yaël ULg; Petit, Véronique; Rindbrand, Mélanie et al

Poster (2014, August)

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See detailCrop association to improve aphid biological control
Chevalier Mendes Lopes, Thomas ULg; Bosquée, Emilie ULg; Bodson, Bernard ULg et al

Poster (2014, August)

This research focused on the development of sustainable alternative methods to control aphids, giving special emphasis on cultural practices and plant management systems. Increasing the diversity within ... [more ▼]

This research focused on the development of sustainable alternative methods to control aphids, giving special emphasis on cultural practices and plant management systems. Increasing the diversity within crops may have several beneficial effects on pest control, creating attractive habitats for indigenous beneficial fauna and simultaneously deterring pests (“push-pull” approach). In this field study, two wheat/pea associations (mixed cropping and strip cropping) where compared to monocultures of pea and wheat. The abundance and diversity of adult aphidophagous beneficials (predators and parasitoids) were accessed weekly, using yellow traps, while aphids were observed directly on plants. All individuals were identified down to the level of species. In both crops, the percentage of aphid infestation and density of colonies were significantly higher in monocultures during the abundance periods. The mixing was particularly beneficial for the pea, while strip cropping was more efficient for the wheat. Concerning beneficials, their abundance was also significantly higher in monocultures, comparing with the other treatments. This study shows that increasing diversity within crops can prevent them from aphid infestations. However, additional methods are needed to attract more efficiently the aphidophagous beneficials, in order to promote the natural control of aphids. [less ▲]

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See detailGenetic parameters for individual birth weight, weaning weight and final weight of crossbred pigs from Piétrain boars
Dufrasne, Marie ULg; Wavreille, José; Piedboeuf, Maureen et al

Poster (2014, August)

Genetic parameters for birth weight (BWT), weaning weight (WWT), and final weight (BW) were estimated for crossbred pigs from Piétrain boars raised in test station. Estimates of direct heritability were ... [more ▼]

Genetic parameters for birth weight (BWT), weaning weight (WWT), and final weight (BW) were estimated for crossbred pigs from Piétrain boars raised in test station. Estimates of direct heritability were moderate (0.25 to 0.42), suggesting that genetic improvement of growth would be possible. Estimates of maternal heritability were 0.24 for BWT and WWT, and 0.05 for BW, indicating that the genetic influence of the dam on growth was not negligible until weaning. Genetic correlations between direct and maternal effects for BWT and WWT were moderate and unfavorable (-0.52 and -0.57 respectively). Direct genetic correlations were high and favorable between traits (0.40 to 0.75), suggesting that a high BWT is a good predictor to produce pigs with high final weight. Maternal genetic correlations between traits were low (0.01 to 0.03). Selection for higher BWT would increase final market weight but should be balanced with survival traits. [less ▲]

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See detailTranscriptomics and Proteomics of a Secondary Green Alga.
Perez, Emilie ULg; Lapaille, Marie; Degand, Hervé et al

Poster (2014, August)

Euglena gracilis is a secondary green alga related to trypanosomes that derives from a secondary endosymbiosis between a phagotrophic ancestor and a prasinophycean green alga. Our general objective is to ... [more ▼]

Euglena gracilis is a secondary green alga related to trypanosomes that derives from a secondary endosymbiosis between a phagotrophic ancestor and a prasinophycean green alga. Our general objective is to study the metabolic interactions established between the secondary plastid and the mitochondrion after the endosymbiotic event and to determine the phylogenetic origin of the genes encoding the proteins involved in the energetic pathways. As a first step, we analysed the subunit composition of the mitochondrial respiratory chain, both in silico and by targeted proteomics, to assess the extent of its similitude with the respiratory chain of Trypanosomatidae. We have shown that Euglena shares many additional subunits with trypanosomes, which suggests that these subunits are not especially associated to a parasitic lifestyle. As a second step, we sequenced the total transcriptome of Euglena and determined the phylogenetic origin of each predicted transcript using a database of about 1000 complete proteomes representing the diversity of life. These analyses confirmed that Euglena recruited its genes from a very diverse set of sources. As a third step, we performed a high-throughput analysis of the mitochondrial proteome of Euglena. Our MS/MS experiments, taking advantage of the availability of our transcriptome, mostly recovered mitochondrial proteins, which indicates that our mitochondrial extracts were quite pure. The identified proteins encompassed about 15 different mitochondrial pathways. We are now in the process of comparing the expression levels of both the transcripts and the corresponding proteins across a range of culture conditions selected to differently stimulate the mitochondrion and the plastid. [less ▲]

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See detailMorphological and functional characterization of Carnobacterium maltaromaticum isolated from vacuum-packed beef with long shelf life
Didimo Imazaki, Pedro Henrique ULg; Tahiri, Assia ULg; Ndedi Ekolo, François et al

Poster (2014, August)

The aim of this study was to perform a morphological and functional characterization of a Carnobacterium maltaromaticum strain with a potential bioprotective effect isolated from vacuum packaged long ... [more ▼]

The aim of this study was to perform a morphological and functional characterization of a Carnobacterium maltaromaticum strain with a potential bioprotective effect isolated from vacuum packaged long shelf life beef. The morphological, biochemical and enzymatic profiles, the influence of different temperatures and atmospheres, and the microbial stability of fresh beef inoculated with the C. maltaromaticum strain were evaluated. The isolated C. maltaromaticum strain presented similar morphological, biochemical and enzymatic profiles as those of two reference strains (LMG 11393 and LMG 22902). The growth of C. maltaromaticum was slower in an atmosphere containing O2 and CO2. Vacuum packing is therefore suitable for this bacterium. An antimicrobial effect against Enterobacteriaceae was highlighted on inoculated fresh meat stored under N2. The functional characterization of this isolate will be further pursued by a genotypic characterization to better understand its potential bioprotective effect. [less ▲]

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See detailHARBIYE AQUEDUCT: A RECORD OF PAST EARTHQUAKES
Lamair, Laura ULg; Degée, Hervé ULg; Hubert, Aurelia ULg et al

Poster (2014, August)

This paper presents a detailed analysis of Harbiye aqueduct (Hatay, Turkey). The region is situated at the junction of two major faults (East Anatolian fault and the Dead Sea fault) and is well known for ... [more ▼]

This paper presents a detailed analysis of Harbiye aqueduct (Hatay, Turkey). The region is situated at the junction of two major faults (East Anatolian fault and the Dead Sea fault) and is well known for his important historic seismicity. The aqueduct is located close to Antioch on the Orontes (known as Antakya). The city was founded in the third century BC. Harbiye aqueduct is characterized by different stages of building (Benjelloun et al., submitted). A phase is dated to Caligula period. After the 37 AD earthquake, the aqueduct was rebuilt. We noticed the presence of two dissociated travertine and a changing of masonry material. We also observed several damages and repair structures dating from Roman time. We assume that our observations are the results of one or more earthquakes. Since the construction of the aqueduct, historical seismic records mention 13 earthquakes that provoked severe damages in the city of Antioch (Guidoboni et al. 1994, Al-Tarazi, 1999, Över et al. 2002). The last one occurred in 1872 (M=7.2). In order to test our hypothesis, we modelled the structure of the aqueduct by using FineLg, a software developed at University of Liege. The seismic signals were chosen in the European Strong-motion database (Ambraseys et al., 2002) according the following criteria: a bedrock station (to avoid site effect), a strike-slip fault mechanism and a distance between the station and the epicenter around 20-30 km. The aqueduct is located at about 25 km of the Dead Sea Fault. We tested several magnitudes for the purpose of estimate the magnitude of the earthquake(s) which destroy(s) the studied aqueduct. Our results highlight the bond between the magnitude, the damage and the weakness area of this type of structure. [less ▲]

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See detailPrediction of stock and fate of phosphorus forms according to soil classification
Renneson, Malorie ULg; Barbieux, Sophie ULg; Dufey, Joseph et al

Poster (2014, August)

Wallonia presents a high diversity of soils and the fate of P in the soil-plant systems can highly vary from one region to another. The fate of phosphorus depends upon its forms in the solid constituents ... [more ▼]

Wallonia presents a high diversity of soils and the fate of P in the soil-plant systems can highly vary from one region to another. The fate of phosphorus depends upon its forms in the solid constituents of soils, which is seldom characterized. For example, total P determines the soil reserve of P but also the potential P content which can be lost to surface water by erosion but analysis of this parameter is time consuming and rarely performed. This study aims (i) to define functional groups of soils for a differentiate P management, (ii) to estimate total soil P by regression equations based on soil parameters, and (iii) to estimate the quality of these predictions. The study consists in a characterization of 12 parent materials in Wallonia, collected across different land uses. A classification of soils was defined by clustering analysis and 5 groups were defined according to P contents and forms. Using this information in regression improved the quality of predictions. The coefficients of determination vary from 0.83 to 0.99, in comparison to a coefficient of 0.77 for the global regression. Then, pedotransfer functions were validated with an independent external dataset of 55 soils. Estimation of the quality of the prediction of P content (mean error, standard deviation of prediction and root mean square error) was made with global and local regression models. In conclusion, using a soil classification allowed to improve P content assessment by specific regressions and to propose differentiated P management for each group of soils. [less ▲]

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See detailAffective Forecasting About Future Events: My Friend Better Than Me?
Christophe, Virginie ULg

Poster (2014, July 31)

Recent findings suggest that we neglect our personality to predict our future emotional reactions to specific events by focusing only on the events, inducing wrong forecasts. An interesting question to ... [more ▼]

Recent findings suggest that we neglect our personality to predict our future emotional reactions to specific events by focusing only on the events, inducing wrong forecasts. An interesting question to investigate is that our friends could predict better our affective states about future events because they take into account our personal dispositions. In the present study, sixty-nine pairs of students (participant/friend) were asked to predict their emotional reactions and those for a friend on a 7-point Likert scale, ranging from 1 (very bad) to 7 (very good) two months before they will obtain their results for one examination. All the participants were contacted by SMS the day when the results were available, and were requested to rate their present affective states. Results showed that emotional predictions were different as compared to the current emotions for extreme results (upper than 8/10, and below 4/10) for the main participants but also for their friends, meaning that all the subjects predicted more positive emotions than current ones for very good results, and more negative emotions than current ones for very bad results. In contrast, the predictions were right for middle results (between 5/10 and 7/10) for both groups. These findings do not show that our friends are better predictors of our future emotional states than us. One possible explanation is that in present study, both participants and friends were concerned about the future event (i.e., academic results). So, our friends could be better forecasters only in the case of future events not shared. [less ▲]

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See detailRole of non-polyQ regions on the aggregation process by polyQ proteins into amyloid fibrils
Huynen, Céline ULg; Willet, Nicolas ULg; Buell, Alexander K et al

Poster (2014, July 28)

Nine neurodegenerative disorders, referred to as polyglutamine diseases and including Huntington’s disease, are associated with the abnormal expansion of a polyglutamine tract inside nine unrelated ... [more ▼]

Nine neurodegenerative disorders, referred to as polyglutamine diseases and including Huntington’s disease, are associated with the abnormal expansion of a polyglutamine tract inside nine unrelated proteins. This polyQ expansion is thought to be the major determinant in the development of neurotoxicity, triggering protein aggregation into amyloid fibrils. A large body of evidence however indicates that non-polyQ regions modulate the aggregation process triggered by polyQ expansions. The interplay between the polyQ tract and non-polyQ regions is complex and still not fully understood. In order to better understand it, we previously designed and characterized model polyQ proteins made of the beta-lactamase BlaP and a 23, 30, 55 or 79Q tract inserted in position 197 or 216. These chimeras recapitulate the aggregation properties of polyQ disease-associated proteins: there is a Q threshold for the formation of amyloid fibrils, and above the threshold, the longer the polyQ, the faster the aggregation. Moreover, the structure of BlaP (native or unfolded) and the position of insertion of the polyQ tract (197 versus 216) influence their aggregation properties. In this work, (i) we will discuss the role of the conformation of the host protein, BlaP, and of the location of the polyQ within BlaP on the different phases of amyloid fibril formation, the nucleation and elongation steps, using mainly quartz crystal microbalance (QCM), atomic force microscopy (AFM) and dynamic light scattering (DLS); and (ii) we will investigate the precise aggregation threshold and the modulating role of the N- and C-terminal polyQ flanking sequences in position 197 of BlaP by creating and characterizing new chimeras containing intermediate length polyQ tracts in position 197, or polyQ tracts inserted between two cleavage sites in position 197, respectively. Our results highlight a linear dependence of the polyQ length on the elongation rate whatever the insertion site and the conformation of BlaP. These two parameters however drastically influence the ability of a polyQ tract to trigger the nucleation and the elongation steps of amyloid fibril formation. Finally, we observed that the propensity to form amyloid fibrils and its rate seems to be largely dependent on the polyQ length and on the polyQ flanking sequences. Altogether our results contribute to identify the important species and elements (polyQ or non-polyQ regions, monomers, oligomers or fibrils) during the aggregation process into amyloid fibrils to interfere with the latter associated with neurotoxicity. [less ▲]

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See detailResorcinol-Formaldehyde Carbon Xerogels as Lithium-Ion Battery Anodes: Synthesis, Grinding, Coating on current collector and Electrochemical characterization
Piedboeuf, Marie-Laure ULg; Léonard, Alexandre ULg; Pirard, Jean-Paul ULg et al

Poster (2014, July 17)

Rechargeable lithium-ion batteries show great advantages over traditional batteries and are extensively used for consumer electronic devices due to their high energy density and long cycle life. However ... [more ▼]

Rechargeable lithium-ion batteries show great advantages over traditional batteries and are extensively used for consumer electronic devices due to their high energy density and long cycle life. However, the improvement of performance of current lithium-ion batteries requires the optimization of the materials used (electrolyte and electrodes). Therefore, tremendous efforts have been dedicated to exploring new materials with high capacity, excellent cycling performance, low cost and high safety features [1-4]. As an example, carbon xerogels are promising candidates in the development of new high performance C-based anode materials for Li-ion batteries, since such carbonaceous materials show very small changes of volume during the charge/discharge process, providing an improved cycle life. Nevertheless, hard carbons also exhibit quite high irreversible capacity losses due to their intrinsic high microporosity and, compared to graphite, a poor rate performance related to slow diffusion of Li in the internal structure [5-6]. To reduce these disadvantages, the structural and textural characteristics need to be carefully controlled. Also, due to the different morphology of these materials compared to graphite, the deposition of carbon xerogels on current collectors needs to be studied in detail. In this work, porous carbon xerogels were synthetized from Resorcinol-Formaldehyde mixtures by adjusting the pH of the solution in order to obtain different mesopore sizes. Monoliths of carbon xerogels were obtained after drying of the polymer gel and pyrolysis [7]. Mercury intrusion porosimetry and nitrogen adsorption techniques (BET) was used to characterize the pore texture of the carbon xerogels. These monoliths were ground to particles around 10 µm for all the samples. The resulting powders were then mixed with a binder and a solvent to form slurries and then cast on copper foil using a bar coater. After evaporation of the solvent, the resulting coatings were analyzed using scanning electron microscopy (SEM) for the morphology and their thickness was monitored by profilometry. The resulting electrodes were subjected to electrochemical characterization. Since the particle sizes and the method of coating was the same for all the samples, it was possible to evaluate selectively the influence of the textural and structural parameters of the different carbon materials on their performances. Electrochemical characterizations were performed using charge-discharge galvanostatic curves and cyclic voltammetry in Li/C half cells between 0.005 and 1.5 V vs. Li+/Li. References 1) Goodenough J.B., Kim Y. J. Power Sources 2011; 196(16): 6688-6694. 2) Bruce P.G. Solid State Ionics 2008; 179: 752-760. 3) Armand M., Tarascon J.-M., Nature 2008; 451: 652-657. 4) Scrosati B., Garche J., J. Power Sources 2010 ; 195 : 2419-2430. 5) Yuan X., Chao Y.-J., Ma Z.-F., Deng X., Electrochemistry Communications 2007 ; 9 : 2591-2595. 6) Zanto E.J., Ritter J.A., Popov B.N., Proceedings - Electrochemical Society 1999; 98-16: 71-8. 7) Job N., Théry A., Pirard R., Marien J., Kocon L., Rouzaud J., Béguin F., Pirard J. Carbon 2005; 43: 2481-2494. [less ▲]

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See detailFrom variability to stability: The acquisition of phonemes in French speaking children aged 30 to 53 months.
MacLeod, Andrea; Maillart, Christelle ULg

Poster (2014, July 16)

When children first begin to produce the phonemes of their language, their productions are characterized by a high degree of variability (e.g., Ferguson & Farwell, 1975). As children’s phonological ... [more ▼]

When children first begin to produce the phonemes of their language, their productions are characterized by a high degree of variability (e.g., Ferguson & Farwell, 1975). As children’s phonological representations become more defined, their productions become more stable. In fact, the observation of variability beyond the early-word stage has been used as a diagnostic criteria for sub-types of phonological disorders (Dodd et al. 2005). Despite the clinical significance of phonological variability, there exists no normative data that can be used to objectively describe this variability in French. The goal of the present study was to describe variability and stability among French-speaking children between the ages of 30 and 53 months. A total of 153 children participated in the present study and were equally distributed in four groups (aged 30-35, 36-41, 42-47, and 48-53 months). We created a picture identification task with 65 target words, which contained the consonants of French in word initial, medial and final position. The children were asked to produce this series of words three times. Two measures of variability were used. (1) A consonant level analysis that investigated the stability of consonants regardless of word or syllable position. (2) A word level analysis that investigated the consistency of productions across the three series (Holm et al., 2007). The preliminary analysis focused on the consonant level analysis and revealed that the youngest group of children aged 30 to 35 months were significantly more variable than the oldest group aged 48-53 months. This shift from variability to stability will be discussed in terms of the development phonological representations. In addition, the clinical significance of variability will be discussed in light of these findings. [less ▲]

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See detailAre expectancies and peers involved in the relation between depressive mood, anxiety and cannabis use in adolescence?
Schmits, Emilie ULg; Quertemont, Etienne ULg; Boulard, Aurore ULg

Poster (2014, July 15)

Background: Cannabis is the most commonly used illicit drug among teenagers and depression is one of the most common psychopathologies in adolescence. The specific symptom of depressive mood is present in ... [more ▼]

Background: Cannabis is the most commonly used illicit drug among teenagers and depression is one of the most common psychopathologies in adolescence. The specific symptom of depressive mood is present in 30% to 40% of adolescents in regular school settings. Links between cannabis use and depression have been highlighted, especially in adolescence. But questions remain about the strength of the association between lifetime cannabis use, depressive mood and anxiety, and about the mechanism underpinning the link. Aim: The aim of this study was to clarify the relationship between depressive mood and lifetime cannabis use in adolescents, particularly through the mediating role of anxiety and cannabis use effect expectancies, and the moderating role of peer cannabis use. Methods: A questionnaire was administered to 1,246 Belgian teenagers aged 16–17 years. ANOVA, chi-square, logistic regressions and mediation/moderation analyses were carried out to model lifetime cannabis use. Results: Depressive mood was positively correlated with lifetime cannabis use. Social anxiety, trait-anxiety and cognitive impairment effect expectancies mediated the effect of depression on lifetime cannabis use. The direct effect of depression on lifetime cannabis use increased when mediators were introduced into the relation, revealing their suppressive effects. The number of peer cannabis users moderated this model. Conclusion: Findings are discussed in terms of potential risk factors (depressive mood) or protective factors (anxiety and expectancies) for lifetime cannabis use, including the self-medication hypothesis. [less ▲]

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See detailDo tree species influence community structure and richness of Ammonia Oxidizing Bacteria at three temperate forest sites?
Malchair, Sandrine ULg; Carnol, Monique ULg

Poster (2014, July 15)

Introduction: The relationship between biodiversity and ecosystem function remains a controversial subject with numerous open questions. In Europe, the conversion of coniferous monocultures into ... [more ▼]

Introduction: The relationship between biodiversity and ecosystem function remains a controversial subject with numerous open questions. In Europe, the conversion of coniferous monocultures into broadleaved or mixed stand is considered to face ecological and economical risks posed by coniferous monocultures. Belowground effects of such a change in the dominant tree species is however largely unknown, although bacteria regulate many soil processes and some groups, like ammonia oxidizing bacteria (AOB) are highly sensitive to environmental stress. Objectives: The aims of this study were to investigate (i) AOB community structure and richness under several tree species, (ii) microbial/environmental factors related to AOB diversity, (iii) the relationship between AOB diversity and the nitrification process. Materials and methods: Forest floor (Of, Oh) was sampled under European beech, sessile oak, Norway spruce and Douglas fir at three sites. AOB community structure and richness was assessed by PCR-DGGE and sequencing. Samples were analysed for net N mineralization, potential nitrification, basal respiration, microbial biomass, microbial or metabolic quotient, pH, total nitrogen, extractable ammonium, organic matter content and exchangeable cations. Results: AOB community structure and tree species effects on AOB diversity were site-specific. Factors regulating ammonium availability, i.e. net N mineralization or microbial biomass, were related to AOB community structure. AOB richness was not related to nitrification. Conclusions: Our research revealed that, at larger spatial scales, site specific characteristics may be more important that tree species in determining AOB richness and community structure. Within sites, tree species influence AOB diversity. The absence of a relation between AOB richness and nitrification points to a possibly role of AOB abundance, phenotypic plasticity or the implication of ammonia oxidizing archaea in this process. [less ▲]

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See detailModification of Conductivity, Superhydrophilicity and Photocatalytic Activity of TiO2 Thin Films Through Carbon Nanotubes Doping
Léonard, Géraldine ULg; Remy, Simon; Malengreaux, Charline ULg et al

Poster (2014, July 15)

In this work, a superhydrophilic and photocatalytic material allowing to reduce the accumulation of electrostatic charges is developed. The superhydrophilicity and photocatalytic activity of TiO2 films ... [more ▼]

In this work, a superhydrophilic and photocatalytic material allowing to reduce the accumulation of electrostatic charges is developed. The superhydrophilicity and photocatalytic activity of TiO2 films provide the “easy-to-clean” property. Indeed, superhydrophilicity induces a very low contact angle between TiO2 and water leading to the formation of a water film at the surface of the material. The photocatalytic activity, responsible for the pollutant decomposition, is explained by the excitation of the semiconductor under UV light leading to the formation of electron-hole pairs. The electrical conductivity of semiconductor TiO2 is very low leading to the accumulation of electrostatic charges and so the surface becomes a dust trap. Multi-walled carbon nanotubes (MWCNTs) are electrical conductors and their introduction in TiO2 could increase the conductivity. The incorporation of MWCNTs can modify the superhydrophilicity of TiO2. The photoactivity can be improved by reducing the electron-hole recombination rate. MWCNTs play a role in electron transfer and allow to decrease the recombination of electron-hole pairs. Two sol-gel syntheses were studied in alcohol and water respectively. In the alcoholic medium, monolayer films are obtained by dip-coating on alkaline free glass and calcined at 300, 400 or 500°C. The thermal treatment allows to crystallize TiO2 in the anatase form. In the aqueous synthesis, monolayer film are obtained by dip-coating on alkaline free glass. The TiO2 shows already the anatase structure. The characterizations of the samples have confirmed the nanotube presence in the aqueous synthesis, and in the alcoholic synthesis at 300°C and 400°C but not at 500°C. The highest conductivity is obtained from the syntheses in alcohol and the calcination at 300°C. That sample does not exhibit a high photoactivity because of its poor crystallinity. The films without MWCNTs are superhydrophilic but the contact angle increase with the incorporation of MWCNTs. The superhydrophilicity is lost with MWCNTs introduction. MWCNTs increase the roughness, the thickness and the electron transfer of the TiO2 matrix. This induces an enhancement of the photoactivity under UV. The comparison between the two syntheses shows that the alcoholic synthesis (400°C) is the best for pure film. When MWCNTs are introduced, the improvement is higher in the case of aqueous synthesis than in the case of alcoholic synthesis. The aqueous synthesis leads to more active photocatalysts than the alcoholic synthesis. [less ▲]

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See detailStudies of early interactions among infants aged 4 to 6 months furtherly diagnosed with autistic spectrum disorder and their developmental trajectories and outcome at 4 years old.
Boulard, Aurore ULg; Wolff, Marion; Morange-Majoux, Françoise et al

Poster (2014, July 14)

The purpose of this study is to observe and analyze the social skills of infants aged 4 to 6 months later diagnosed with autism. Through the family films collected, we compared 28 children later diagnosed ... [more ▼]

The purpose of this study is to observe and analyze the social skills of infants aged 4 to 6 months later diagnosed with autism. Through the family films collected, we compared 28 children later diagnosed with autism to 28 typically developing children strictly matched on chronological age and sex. To do this, we used the social behavior assessment scale (SBAS). This scale measures the behavior of the infant (turning his head, looking, smile, vocalize ...) in response to 5 parental stimuli (1.calling by her / his name, 2.saying peek-a-boo, a vocal sound 3.Producing , 4.filmed in silent 5.simultaneous interactions with one or more persons). Then we analyzed the responses behaviors of these children with the software "the observer". Results show evidence that, contrary to infants with typical development, infants later diagnosed as autistic made less visual contact, smile or vocalize less in response to parental stimuli. However, even if the responses of autistic children are statistically different in quantity (compared to the control group), responses to parental stimuli are still present. In a second step, we studied the developmental trajectories of children with autism. Our hypothesis was that children with a low score at the SBAS would have a lower global development score than the children with a high score at the SBAS at 3 years old. Our results validate our hypothesis. [less ▲]

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See detailSelf broadening coefficients and improved line intensities for the n7 band of C2H4 near 10.5 mm, and impact on ethylene retrievals from Jungfraujoch solar spectra
Vander Auwera, Jean; Fayt, André; Tudorie, Marcela et al

Poster (2014, July 10)

Ethylene (ethene, C2H4) is a tropospheric pollutant on the Earth, also present as a by-product of methane photochemistry in the atmosphere of outer solar system bodies. Remote sensing of ethylene in the ... [more ▼]

Ethylene (ethene, C2H4) is a tropospheric pollutant on the Earth, also present as a by-product of methane photochemistry in the atmosphere of outer solar system bodies. Remote sensing of ethylene in the infrared range relies on the 10 mm region. This spectral range corresponds to the excitation of 7 modes of vibration of 12C2H4, 4 of which being infrared active (see Fig. 1 of [1]). The corresponding n10, n7, n4 and n12 bands are located near 826, 949, 1026 and 1442 cm-1, respectively [1]. Among these, the n7 band is the strongest, indeed used for remote sensing measurements of ethylene. Relying on high-resolution Fourier transform infrared (FTIR) spectra recorded in Brussels, the present work involved extensive measurements of individual line intensities and self broadening coefficients for the n7 band of 12C2H4. Compared to the corresponding information available in the latest edition of the HITRAN spectroscopic database (HITRAN 2012 [2]), the measured line intensities were found to be higher by about 10 % for high J lines in the P branch and lower by about 5 % for high J lines of the R branch, varying between these two limits roughly linearly with the line positions. Test calculations performed in this work indicated that these discrepancies could result from the relative values of the transition moments of the n10, n7 and n12 bands used when the information provided in HITRAN was generated (the transition moment of the n4 band was set to zero). The measured self broadening coefficients exhibit a dependence on both J and Ka, which was modeled empirically. The spectroscopic information for ethylene available in HITRAN 2012 was modified to match the present observations. The impact of these modifications on retrievals of atmospheric ethylene was then evaluated via FTIR retrievals in the 949.0 – 952.0 cm-1 microwindow, from a subset of ground-based high-resolution FTIR solar spectra recorded at the Jungfraujoch station. The new line intensities were found to lead to a reduction of the measured total columns of ethylene by -4.1±0.1 %, compared to the use of HITRAN 2012. [less ▲]

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See detailWhich links exist between depression, engagement in activities’ level and several psychological processes?
Wagener, Aurélie ULg; Blairy, Sylvie ULg

Poster (2014, July 09)

In Europe, depression affects 33.4 millions of people every year. According to the World Health Organization, depression will be the leading cause of disabilities in 2030. This highlights the need for ... [more ▼]

In Europe, depression affects 33.4 millions of people every year. According to the World Health Organization, depression will be the leading cause of disabilities in 2030. This highlights the need for available, effective and efficient treatments of this psychopathology. In order to offer such treatments, there is a need for a deep understanding of depression’s mechanisms. Depression is characterized by a decrease of the level of engagement in activities: for instance, depressed patients stay in bed, don’t see friends, don’t go out anymore and can be on sick leave for a long period of time. Reciprocally, this decrease maintains depressive symptoms. This link between depression and level of engagement in activities is well-established in the scientific literature. However, no study has, until yet, determined which psychological processes are mediators of this link. Therefore, this study’s aim is to determine these psychological processes. In order to reach this aim, 500 subjects, suffering from psychopathology or not, will fulfill a set of questionnaires. These questionnaires will assess mood (anxiety and depression), level of engagement in activities and five categories of psychological processes that have been selected from different theoretical models of depression (self-image, environmental satisfaction, negative repetitive thoughts, experiential avoidance and emotional regulation). Statistical analysis will be performed in order to confirm a LISREL model. Data collection is ongoing and results will be presented and discussed during the congress. [less ▲]

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See detailLarge-scale stochastic optimization using non-stationary geostatistics for uncertainty assessment of groundwater flow and solute transport, in the framework of a near surface radioactive waste disposal
Rogiers, Bart; Laloy, E.; Gedeon, Matej et al

Poster (2014, July 09)

Uncertainty quantification is very much needed to support decision making related to e.g. environmental impact assessment for waste disposal sites. A probabilistic result provides a much stronger basis ... [more ▼]

Uncertainty quantification is very much needed to support decision making related to e.g. environmental impact assessment for waste disposal sites. A probabilistic result provides a much stronger basis for decision making compared to a single deterministic outcome. Accurate posterior exploration of high-dimensional and CPU-intensive models, which are often used for environmental impact assessment, is however a challenging task. To quantify the uncertainty associated with solute transport in the framework of a near surface radioactive waste disposal in Mol/Dessel, Belgium, we investigate combining the adaptive Metropolis (AM) McMC algorithm for updating the global model parameters, and adaptive spatial resampling (ASR) for updating of the spatially distributed model parameters, by block sampling. The forward model used is a groundwater flow model conditioned on borehole and direct push data, that accounts for non-stationary heterogeneity in hydraulic conductivity. The obtained flow solutions are used for solute transport simulations, and the results are compared with a different groundwater flow model parameterization, that makes use of homogeneous hydrogeological layers. Moreover, a number of simulations is performed to assess the effect of realistic dispersivity, which is derived from outcrop investigations. The obtained results indicate that the combination of AM and ASR using block sampling seems not to be very efficient for McMC sampling with the forward model used in this study. However, using the algorithm in optimization mode seems to work fine, and provides an alternate way for exploring the parameter space and the prediction uncertainty. [less ▲]

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See detailA longitudinal perspective of alcohol use among adolescents: the predictive role of peers and internalizing factors.
Schmits, Emilie ULg; Glowacz, Fabienne ULg; Quertemont, Etienne ULg

Poster (2014, July 09)

Alcohol is the most commonly used psychoactive substance among teenagers. Consumption is influenced by environmental factors and personal characteristics, events or experiences. High use can lead to ... [more ▼]

Alcohol is the most commonly used psychoactive substance among teenagers. Consumption is influenced by environmental factors and personal characteristics, events or experiences. High use can lead to substantial problems, especially after an early consumption. Detecting and preventing an increase of alcohol use among teenagers, through the identification of risk and protective factors, seems essential in terms of public health. This study aimed to examine the progression of use in young teenagers, to identify protective and risk factors of alcohol use (including peers and internalizing factors) and to specifically focus on the influence of social anxiety. A questionnaire was administered twice to 877 teenagers (49.94% female, M=15.61) with one year interval (T1 and T2). Sex, age, alcohol use, number of friends, social comparison, trait-anxiety, social anxiety and depression were assessed through validated scales. T-test for paired sample and hierarchical regressions were performed. During the follow-up year, the average alcohol use significantly increased. A positive social comparison at T1 significantly predicted alcohol use at T2. The more teenagers positively compared themselves to their friends and felt popular, the more they consume alcohol. A similar significant effect was demonstrated for depression. The more young people manifested depressive affects at T1, the more they used alcohol at T2. However, social anxiety significantly protected from this substance use. More social anxiety at T1 was associated with less alcohol consumption at T2. The number of friends and trait-anxiety at T1 did not significantly influence alcohol use at T2. A positive social comparison and depressive affects could be considered as risk factors, whereas social anxiety could be defined as protective factor. At this developmental period, young people suffering from social anxiety symptoms subsequently use less alcohol, maybe due to the lack of contact with this substance usually socially consumed, whereas more popular and integrated teenagers are more at risk. The present results challenge the tension-reduction model according to which alcohol is consumed to reduce anxious affects and to facilitate social relationships. However, results suggest that alcohol might be used to reduce unpleasant depressive affects. [less ▲]

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See detailOn the use of carbon dioxide and vegetable oil for the synthesis of bio-based cyclic carbonates
Alves, Margot ULg; Tassaing, Thierry; Mereau, R. et al

Poster (2014, July 03)

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See detailComparaison du niveau d’estime de soi dans deux populations ayant des caractéristiques démographiques différentes : des arbitres et des non-arbitres
Van Hoye, Martin ULg; Cloes, Marc ULg

Poster (2014, July 03)

Si le sport forge le caractère, l’arbitrage devrait également responsabiliser les individus qui l’exercent. Aussi, on peut considérer que les arbitres pourraient développer une meilleure estime d’eux ... [more ▼]

Si le sport forge le caractère, l’arbitrage devrait également responsabiliser les individus qui l’exercent. Aussi, on peut considérer que les arbitres pourraient développer une meilleure estime d’eux-mêmes ? Dans cette recherche, nous avons tenté de vérifier cette hypothèse en analysant le niveau d’estime de soi de deux échantillons distincts : des arbitres de basket-ball (n=163) et des personnes n’ayant aucune expérience au niveau de l’arbitrage (n=163). L’instrument que nous avons utilisé est « l’Echelle de l’Estime de Soi » (EES). La moyenne générale au questionnaire est légèrement supérieure chez les arbitres (30,9 vs 30,5) mais il ne s’agit pas d’une différence significative (p=0,8372). L’ancienneté dans l’arbitrage ou l’âge des individus ne semblent pas être un facteur influençant l’estime de soi des arbitres. Il conviendrait de vérifier s’il en est de même dans les autres disciplines sportives que le basket-ball. [less ▲]

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See detailEvaluation des effets à court terme de l’intervention « Bouger plus » sur la pratique d’activité physique des seniors
Rompen, Jérôme ULg; Mouton, Alexandre ULg; Grimont, Pierre et al

Poster (2014, July 03)

Des outils basés sur un site internet sont efficaces pour promouvoir l’activité physique (AP) chez les seniors (Ammann et al., 2013). Cette étude avait pour but d’évaluer les effets de l’intervention « ... [more ▼]

Des outils basés sur un site internet sont efficaces pour promouvoir l’activité physique (AP) chez les seniors (Ammann et al., 2013). Cette étude avait pour but d’évaluer les effets de l’intervention « Bouger plus » sur la pratique d'AP de sujets de 50 ans et plus, au sein d’une commune. Quatre groupes ont reçu une intervention différente pendant trois mois : un site internet (I), un cours collectif (CC), une combinaison des deux (CCI) et pas d'intervention (CO). Des questionnaires ont permis d’évaluer les résultats. Ceux-ci montrent une évolution positive du stade de changement de comportement vis-à-vis de l’AP, au cours de l’intervention, pour les groupes I et CCI. De plus, le niveau de pratique est resté stable malgré la période hivernale pour les groupes CC et CCI alors qu’il a chuté pour le groupe CO. L’intervention a donc eu des effets positifs à court terme sur les comportements en matière d’AP, particulièrement quand le site internet et les cours collectifs étaient combinés. [less ▲]

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See detailLa verbalisation: un outil performant permettant une amélioration de l'estime de soi? Analyse de cas chez des arbitres de basket-ball
Van Hoye, Martin ULg; Cloes, Marc ULg

Poster (2014, July 03)

L’estime de soi représente une dimension importante de notre personnalité, notamment chez les adolescents, souvent poussés par un important besoin de se montrer compétents en toute situation. Notre ... [more ▼]

L’estime de soi représente une dimension importante de notre personnalité, notamment chez les adolescents, souvent poussés par un important besoin de se montrer compétents en toute situation. Notre objectif consistait à améliorer l’estime de soi de jeunes arbitres de basket-ball (n=22) à l’aide d’une verbalisation d’après match. Nous avons comparé les résultats obtenus entre un groupe expérimental et un groupe contrôle. A l’issue de cette étude, nous n’avons observé aucun changement chez les sujets du groupe contrôle. Par ailleurs, une légère amélioration non-significative a été observée dans le groupe expérimental (+1,2/40). D’autre part, d’autres analyses nous permettent de conclure que l’utilisation de la verbalisation a bel et bien été bénéfique aux sujets expérimentaux. Nous pensons que ces arbitres réfléchiraient plus spontanément sur leur prestation. Ceci pourrait les aider à progresser, aussi bien en tant qu’arbitre qu’en tant qu’individu à proprement parler. Indirectement, cela les aiderait à augmenter leur estime de soi. [less ▲]

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