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See detailSpeech style manipulations in dysarthria in French-speaking children: Acoustic findings.
Ancelle, Josephine; Moya Gale, G.; Hetrick, B et al

Poster (2016, November)

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See detailPreoptic glutamate and estradiol release during male sexual behavior
de Bournonville, Catherine ULg; de Bournonville, Marie-Pierre ULg; Aourz, Najat et al

Poster (2016, November)

Beside its long-term control by steroids, male sexual behavior is also modulated by neuroestrogens in a dynamic way (within minutes) in a number of species ranging from fishes to mammals. Studies in male ... [more ▼]

Beside its long-term control by steroids, male sexual behavior is also modulated by neuroestrogens in a dynamic way (within minutes) in a number of species ranging from fishes to mammals. Studies in male Japanese quail have also identified following exposure to a receptive female a rapid decrease in the activity of brain aromatase (AA) the enzyme responsible for the conversion of androgens into estrogens. These effects occur mainly within the medial preoptic nucleus (POM), a sexually dimorphic structure of the preoptic area that plays a key role in the activation of male sexual behavior and contains the highest AA in the brain. In vitro studies demonstrated that AA can be rapidly inhibited by calcium-dependent phosphorylations of the enzyme triggered by the activation of AMPA and kainate receptors. We confirmed here this rapid effect of glutamate on AA by injecting kainate in the POM of anesthetized males and measuring AA in the tissue after brain collection. AA in POM was inhibited in the kainate-injected hemisphere compared to the control hemisphere injected with vehicle. In a second experiment, we showed by in vivo microdialysis that glutamate is released in POM during copulation. These results thus suggest that glutamate controls dynamic changes of AA that occur in the brain during sexual interactions. To confirm that the decrease in AA leads to an actual reduction of local estradiol concentration, we quantified via microdialysis and radioimmunoassay changes in estradiol concentration in the male POM during sexual interactions with a female. Surprisingly, a dramatic elevation of estradiol was observed during copulation. Estradiol has been shown to enhance acutely male sexual motivation, therefore the function of its increase in the POM could be to maintain motivation during the entire sexual encounter. The decrease of AA observed ex vivo after copulation would then reflect a compensatory mechanism to restore baseline pre-copulatory conditions. Importantly, these results highlight that although long-term changes in AA are often used as a proxy for local estradiol concentrations, these two measures can show major short-term discrepancies possibly reflecting variations in estrogen turnover. [less ▲]

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See detailBiofilm fermentation for the production of insect pathogenic fungi
Bawin, Thomas ULg; Francis, Frédéric ULg; Delvigne, Frank ULg

Poster (2016, July 27)

Currently, integrated pest management that aims to reduce the use of synthetic insecticides by considering all appropriate alternative methods, is promoted. In that context, insect pathogenic fungi could ... [more ▼]

Currently, integrated pest management that aims to reduce the use of synthetic insecticides by considering all appropriate alternative methods, is promoted. In that context, insect pathogenic fungi could be developed as biopesticides in two ways: spores but also metabolites that are recognized as virulence factors. Targeting adequate fermentation method is an important requirement to obtain fungal products (i.e. spores, enzymes and metabolites) of biotechnological interest. The 'Microbial Processes and Interactions' laboratory has developed an innovative fermentation technology (referred to as ‘biofilm fermentation’) involving the growth of fungal biomass on inert supports that are immersed in a liquid nutrient medium. Confining fungal biomass on immersed inert structures provides a hybrid production system aiming to keep a solid-state physiology for sporulation and secretion of metabolites while controlling fermentation parameters. This research project proposes to transfer this technology to culture insect pathogenic fungi, such as Metarhizium anisopliae, for the production of spores and insecticidal metabolites. Development stages include the qualitative and quantitative characterization of its impact on insecticidal products as well as scale-up to industrial level. [less ▲]

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See detailAharonov-Bohm oscillations of bosonic matter-wave beams in the presence of disorder and interaction
Chrétien, Renaud ULg; Dujardin, Julien; Petitjean, Cyril ULg et al

Poster (2016, July 27)

We study the one-dimensional (1D) transport properties of an ultracold gas of Bose-Einstein condensed atoms through Aharonov-Bohm (AB) rings. Our system consists of a Bose-Einstein condensate (BEC) that ... [more ▼]

We study the one-dimensional (1D) transport properties of an ultracold gas of Bose-Einstein condensed atoms through Aharonov-Bohm (AB) rings. Our system consists of a Bose-Einstein condensate (BEC) that is outcoupled from a magnetic trap into a 1D waveguide which is made of two semi-infinite leads that join a ring geometry exposed to a synthetic magnetic flux φ. We specifically investigate the effects both of a disorder potential and of a small atom-atom contact interaction strength on the AB oscillations. The main numerical tools that we use for this purpose are a mean-field Gross-Pitaevskii (GP) description and the truncated Wigner (tW) method. We find that a correlated disorder suppress the AB oscillations leaving thereby place to Aronov-Al’tshuler-Spivak (AAS) oscillations. The competition between disorder and interaction leads to a peak inversion at Φ = π, that is a signature of a coherent backscattering (CBS) peak inversion. This is confirmed by truncated Wigner simulations. [less ▲]

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See detailQuantitative characterization and calibration of salt water intrusion models with electrical resistivity tomography
Beaujean, Jean; Hermans, Thomas ULg; Vandenbohede, Alexander et al

Poster (2016, July 26)

Groundwater quality and coastal ecosystems in coastal areas are among the most vulnerable as they are threatened by excessive groundwater withdrawals, sea level rise and storm events potentially leading ... [more ▼]

Groundwater quality and coastal ecosystems in coastal areas are among the most vulnerable as they are threatened by excessive groundwater withdrawals, sea level rise and storm events potentially leading to salt water intrusions or infiltration into fresh water aquifers. The environmental protection and sustainable management of these groundwater resources often involves the development and calibration of a groundwater model subsequently used to forecast the total dissolved solid content (TDS). However, groundwater models are often built based on a limited number of sparse data due to borehole availability. Geophysical methods can provide spatially and temporally distributed data for hydrogeological modeling at relatively limited costs. In particular, electrical resistivity tomography (ERT) is very sensitive to the conductivity of pore water which is directly linked to the TDS content. The method is therefore well-suited for the monitoring of salt water intrusions. However, the inversion of ERT data involves a regularization process so that the resulting tomogram is only an estimate of the true resistivity distribution, suffering from smoothing and varying resolution. In many cases, the interpretation of ERT remains qualitative and skewed. In this contribution, we propose two different methods to improve the information content that can be extracted from ERT data. First, we show with a field example from Belgium how alternative regularization methods can be developed to integrate independent information into the inversion process of ERT. This enabled us to obtain a resistivity distribution much closer to the one observed in validation boreholes. Then, a site-specific petrophysical relationship is used to derive the TDS content of the aquifer from ERT tomograms. This can be directly used as input in the calibration process of a hydrogeological model. We also show how it is possible to counterbalance the effect of resolution loss with depth for surface ERT by filtering the results relative to their sensitivity. We show that this filtering is mandatory to use the ERT-derived information for calibrating a hydrogeological model. In a second example, we show how a fully coupled inversion approach can be used to directly invert geophysical data together with hydrogeological data for the calibration of hydrogeological models. At each iteration of the calibration, the simulated TDS content is transformed in a resistivity distribution using a parameterized petrophysical relationship and forward geophysical modeling yields the geophysical response. We show that this approach enables to better estimate the hydrogeological parameters of the simulated coastal aquifer than with an uncoupled approach if the conceptual model is sufficiently representative. With those two examples, we demonstrate the usefulness of ERT in the monitoring of salt water intrusions, both qualitatively to identify most vulnerable zones and quantitatively to estimate ERT-derived TDS contents or geophysical data and calibrate hydrogeological models. An innovative approach may consist in a conjunctive use of filtered geophysically-derived and geophysical data within the coupled hydrogeophysical inversion framework. Such an uncoupled-coupled approach based on a resolution threshold approach may offer a promising developing trend in hydrogeophysical inversion. [less ▲]

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See detailImpacts of entomopathogenic fungi on biology and behaviour of the invasive Brown Marmorated Stink Bug (Hemiptera, Pentatomidae)
Fingu Mabola, Junior Corneille ULg; Serteyn, Laurent ULg; Bawin, Thomas ULg et al

Poster (2016, July 25)

Halyomorpha halys St˚al (Hemiptera, Pentatomidae) is an invasive stink bug coming from Eastern Asia. Besides causing important yields losses in orchards, crop and vegetable fields, it overwinters inside ... [more ▼]

Halyomorpha halys St˚al (Hemiptera, Pentatomidae) is an invasive stink bug coming from Eastern Asia. Besides causing important yields losses in orchards, crop and vegetable fields, it overwinters inside houses as agglomerates of dozens. In Europe, this Brown Marmorated Stink Bug (BMSB) was accidentally introduced in Switzerland in 2007 and has been later observed in surrounding countries (France, Italy, Germany). Based on the current US situation, we can reasonably fear that BMSB will have colonized most of Europe countries in less than a decade. If we already discern a few fungus strains that are efficient against BMSB, very little is known about their actual impact on the insect itself. So we investigated the in- fluence of a fungal infection on insect development parameters and behaviour. Olfactometry was settled to investigate the dispersion and aggregation trends, while electropenetography was used to assess the feeding behaviour. Our results will be discussed to present changes according to healthy/fungus-infected status, in relation to potential biological control for that pest. [less ▲]

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See detailRecollection versus familiarity in normal aging and in mild cognitive impairment: Impact of test format.
Simon, Jessica ULg; Gilsoul, Jessica ULg; SALMON, Eric ULg et al

Poster (2016, July 18)

The aim of this study was to investigate the impact of test format on recollection and familiarity in normal aging and in MCI. Seventy young participants, 65 younger-old, 53 older-old, and 13 MCIs were ... [more ▼]

The aim of this study was to investigate the impact of test format on recollection and familiarity in normal aging and in MCI. Seventy young participants, 65 younger-old, 53 older-old, and 13 MCIs were presented with forced-choice and yes/no visual recognition memory tasks with the Remember/Know/Guess paradigm. The young people had better recognition performance than younger-old, who performed better than older-old and MCIs. Recollection and familiarity declined progressively in healthy aging. In MCI, recollection was more affected than familiarity, but patients demonstrated a more liberal use of familiarity. Finally, test format did not influence strongly the results. Young people used recollection more often in the forced-choice task compared to the yes/no task. [less ▲]

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See detailDevelopment and optimization of a TD-GC/MS methodology for detection and quantifi cation of furan released in air using of an experimental design.
Alsafra, Zouheir ULg; Scholl, Georges ULg; Romain et al

Poster (2016, July 07)

In the aim of understanding the way in which human is exposed to furan present in the air of an occupational area, an analytical method of Thermal desorption-gas chromatography/Mass spectrometry (TD-GC/MS ... [more ▼]

In the aim of understanding the way in which human is exposed to furan present in the air of an occupational area, an analytical method of Thermal desorption-gas chromatography/Mass spectrometry (TD-GC/MS) has been developed and optimized using a Plackett–Burman experimental design. This method was then used to study the phenomena of diffusion of furan released in air from a contamination source. This source of furan is simply a coffee machine located in a closed controlled room. Results show that furan concentration increases quickly over time after turning on the coffee machine until reaching a maxima. Then it starts to decrease slowly. On the other hand, concentration of furan seems to be identical everywhere in the conditioned room in each moment. [less ▲]

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See detailNovel butanol pretreatment significantly improves delignification and saccharification of different lignocellulosic biomasses
Schmetz, Quentin ULg; Teramura, Hiroshi; Jacquet, Nicolas ULg et al

Poster (2016, July 07)

Organosolv pretreatment using diluted acid and butanol allows the separation of cellulose, hemicelluloses and lignin into three distinct phases. The butanol process has been investigated on six different ... [more ▼]

Organosolv pretreatment using diluted acid and butanol allows the separation of cellulose, hemicelluloses and lignin into three distinct phases. The butanol process has been investigated on six different biomasses: tall fescue, sugarbeet pulp, sugarcane bagasse, beech wood, eucalyptus and Japanese cedar. Dilute acid pretreatment has been performed under similar conditions for comparison. [less ▲]

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See detailNonlinear analysis of compliant mechanisms: application to tape springs
Dewalque, Florence ULg; Bruls, Olivier ULg

Poster (2016, July 07)

Brief summary of the mechanical behaviour of tape springs. Main results obtained by the means of finite element models. Description of the experimental set-up and results. See the extended abstract for ... [more ▼]

Brief summary of the mechanical behaviour of tape springs. Main results obtained by the means of finite element models. Description of the experimental set-up and results. See the extended abstract for more details. [less ▲]

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See detailIntegrated microfluidic device for in line SERS detection for glyphosate and related metabolites
Emonds-Alt, Gauthier ULg; Malherbe, Cédric ULg; Monbaliu, Jean-Christophe ULg et al

Poster (2016, July 07)

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

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

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See detailRestricted interests in autism with versus without speech onset delay : the importance of perceptually versus thematically organized interests
Chiodo, Liliane ULg; Majerus, Steve ULg; Eusèbe, Sandrine et al

Poster (2016, July 07)

Objectives : To explore whether autistic adults with vs without speech delay also differ in the perceptual vs thematic nature of their restricted interests.

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See detailOptimisation de la production d’acide furan-2,5-dicarboxylique à partir de déchets verts pour la conception de plastiques bio-basés
Istasse, Thibaut ULg; Jacquet, Nicolas ULg; Richel, Aurore ULg

Poster (2016, July 06)

Afin de trouver des alternatives renouvelables aux produits issus de l’industrie pétrochimique, de nombreuses voies de recherches ont été explorées. Une voie prometteuse est la technologie des dérivés ... [more ▼]

Afin de trouver des alternatives renouvelables aux produits issus de l’industrie pétrochimique, de nombreuses voies de recherches ont été explorées. Une voie prometteuse est la technologie des dérivés furaniques. Parmi ces composés, le 5-hydroxyméthylfurfural (5-HMF) fait partie des molécules plateformes les plus importantes1. Il s’agit d’un produit de dégradation obtenu par déshydratation des hexoses2,3. Le 5-HMF peut servir de base à la conception de nombreuses molécules valorisables comme l’acide furan-2,5-dicarboxylique dont la structure proche de l’acide téréphtalique permet des applications dans la conception de polymères bio-basés3. L’acide furan-2,5-dicarboxylique respecte la législation REACH selon l’European Chemicals Agency4. Un rapport de l’EFSA de 2014 a démontré que cette substance ne posait pas de problème de toxicité lors de son utilisation comme monomère de base dans les plastiques d’emballage pour aliments5. Selon la société Avantium, le FDCA peut être utilisé pour produire un plastique entièrement bio-basé, le polyéthylène furanoate (PEF), qui affiche des performances supérieures à celle du poléthylène téréphtalate (PET) en termes de stabilité thermique, de propriétés mécaniques et de perméabilité aux gaz6. Si le FDCA peut être convertit en de nombreux produits à haute valeur ajoutée, il existe toutefois un frein majeur à son exploitation industrielle : son précurseur, le 5-HMF, n’est pas encore produit en grande quantité1. Ce problème est dû principalement à la déshydratation non sélective des sucres de la biomasse qui aboutit à de nombreux autres produits que le 5-HMF. La première difficulté à surmonter est donc la mise au point d’un procédé permettant de déshydrater de manière efficace et sélective les sucres de la biomasse. Le 5-HMF est également peu stable en milieu acide où il se décompose en acide formique et en acide lévulinique2. L'enjeu du projet de recherche présenté est donc l’optimisation de la production de 5-HMF à partir d’un ou plusieurs types de biomasses dans un premier temps, puis l’optimisation de la conversion du 5-HMF produit en FDCA. Les paramètres à prendre en compte sont notamment les sources de biomasse, l’efficacité des prétraitements concernant l’extraction des sucres, la sélectivité et l’efficacité de la conversion de ces sucres en 5-HMF (système mono- ou biphasique), l’étude de divers catalyseurs, le coût des traitements, etc… [less ▲]

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See detailEtude de la composition chimique de Pseudotsuga menziesii (Mirb.) Franco et évaluation de l’impact de divers prétraitements lignocellulosiques sur l’extraction de la lignine
Berchem, Thomas ULg; Schmetz, Quentin ULg; Jacquet, Nicolas ULg et al

Poster (2016, July 06)

La raréfaction des ressources fossiles est une certitude à l’heure actuelle. Il est donc primordial de trouver des voies de production plus durables pour des produits de consommation courante. Le ... [more ▼]

La raréfaction des ressources fossiles est une certitude à l’heure actuelle. Il est donc primordial de trouver des voies de production plus durables pour des produits de consommation courante. Le bioraffinage fait partie des solutions envisagées pour substituer les matériaux originaires de la filière pétrochimique. Dans cette optique, ce travail se focalise sur l’extraction et la caractérisation de la lignine à partir d’une biomasse présente en abondance en région Wallonne, Pseudotsuga menziesii (Mirb.) Franco (Douglas). Ce travail vise à montrer l’impact de divers prétraitements lignocellulosiques, tant en terme de rendements et de pureté d’extraction qu’au niveau de la modification de la structure et des propriétés des lignines. Ces différents paramètres sont évalués par des techniques gravimétriques (Klason), chromatographiques (chromatographie d’exclusion stérique) et spectroscopiques (RMN 2D HSQC). Pseudotsuga menziesii (Mirb.) Franco a été préalablement caractérisé par son taux de matière lignocellulosique (cellulose, hémicelluloses, lignine), ainsi que sa teneurs en cendres, en protéines et en extractibles (à l’eau et à l’éthanol). Les lignines natives ont été caractérisées par RMN 2D HSQC. [less ▲]

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See detailHigh-temperature and quantitative XRD study of typical Westerwald clays (Germany)
Fontaine, François ULg; Fagel, Nathalie ULg

Poster (2016, July 05)

The Westerwald is one of the largest and oldest clay mining area of Germany. Those deposits were formed during the Eocene and Oligocene as a result of the weathering, erosion and redeposition of Devonian ... [more ▼]

The Westerwald is one of the largest and oldest clay mining area of Germany. Those deposits were formed during the Eocene and Oligocene as a result of the weathering, erosion and redeposition of Devonian rocks. During the Miocene, intense volcanic activities led to a large basalt cover, protecting the clays from the erosion. The fine fraction is mainly composed of kaolinite and illite, with the possible presence of interstratified I S. Other minerals such as quartz, feldspars, hematite, goethite or anatase are present in variable concentrations. Four typical Westerwald clays were chosen for this study: kaolinite-rich clay, kaolinite-illite clay, a red and a yellow firing clays. The first goal is to perform quantitative XRD using two different methods and to compare them: reference intensity ratio (RIR) and Rietveld (using Topas and BGMN). The second goal is the study of those samples using high-temperature XRD (HTXRD). The samples were heated up to 1250°C and a XRD pattern was obtained in situ every 100°C. The results show the temperatures of vitrification and formation of mullite and cristobalite varying from one sample to another, which is mainly linked to their flux concentration. [less ▲]

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See detailL’intégration d’indicateurs biologiques dans un réseau de surveillance des sols afin d’améliorer le diagnostic de la qualité du sol – une étude de cas dans le sud de la Belgique (Wallonie)
Krüger, Inken ULg; Chartin, Caroline; van Wesemael, Bas et al

Poster (2016, July 05)

Les organismes du sol et leurs activités sont essentiels pour le fonctionnement de l’écosystème du sol et ils peuvent donc servir comme indicateurs de la qualité du sol. Des efforts ont récemment été ... [more ▼]

Les organismes du sol et leurs activités sont essentiels pour le fonctionnement de l’écosystème du sol et ils peuvent donc servir comme indicateurs de la qualité du sol. Des efforts ont récemment été menés pour intégrer les indicateurs biologiques de la qualité du sol dans les réseaux de surveillance régionaux/nationaux. Le but de cette étude était de déterminer des gammes de valeurs pour six indicateurs biologiques et deux quotients éco-physiologiques pour les sols agricoles. La respiration potentielle, la biomasse microbienne (carbone et azote), la minéralisation nette de l’azote, la diversité métabolique des bactéries du sol, l’abondance des vers de terre, le quotient microbien et le quotient métabolique ont été mesurés dans 60 sites dans des régions agricoles contrastées (différents types de sol et climat) et différentes utilisations de sol (prairies et cultures) sélectionnés d’un réseau de surveillance du carbone organique du sol (CARBOSOL). Les liens entre indicateurs biologiques et paramètres chimiques (le pH du sol, carbone organique total, soluble, labile et stable) sont analysés. Quatre des six indicateurs biologiques sélectionnés (respiration potentielle, biomasse microbienne (carbone et azote) et diversité métabolique des bactéries du sol) sont significativement plus élevés sous prairies que sous cultures. Les gammes de valeurs sont plus larges sous prairies que sous cultures. Les indicateurs biologiques sélectionnés ne sont pas significativement influencés par la région agricole. Les meilleures corrélations avec les paramètres chimiques ont été trouvées pour la respiration potentielle et la biomasse microbienne (carbone et azote). L’étude définit des gammes de valeurs pour les sols agricoles à l’échelle régionale (Wallonie) séparées par utilisation de sol (prairies et cultures) et présente une base solide pour l’établissement d’un réseau de surveillance de la qualité biologique du sol. [less ▲]

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See detailPIXE-PIGE analysis of Early Medieval Glass Artefacts at IPNAS cyclotron external beam line
Chene, Grégoire ULg; Van Wersch, Line ULg; Biron, Isabelle et al

Poster (2016, July 05)

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See detailInterspecific variation of warning calls in piranhas: comparative analysis
Mélotte, Geoffrey ULg; Michel, Christian ULg; Vigouroux, Régis et al

Poster (2016, July)

Fish sounds are often considered as species-specific with unique temporal and spectral features. Differences between acoustic signals of closely related species could be considered as pre-zygotic barrier ... [more ▼]

Fish sounds are often considered as species-specific with unique temporal and spectral features. Differences between acoustic signals of closely related species could be considered as pre-zygotic barrier and could be related to the evolutionary history of the species. In the present study, sounds were recorded and compared in eight piranha species (Serrasalmus elongatus, Serrasalmus marginatus, Serrasalmus compressus, Serrasalmus manueli, Serrasalmus spilopleura, Serrasalmus rhombeus, Serrasalmus eigenmanni and Pygocentrus nattereri) in order to evaluate the potential role of acoustic communication as a driving force in the clade diversification. The same kind of sound-producing mechanism was found in all the species: sonic muscles originate on vertebrae and attach to a tendon surrounding ventrally the bladder. Contractions of the sound-producing muscles force swimbladder vibration. Having the same kind of sound-producing mechanism, the calling features of the eight piranha species show logically many common characteristics. In all the species, the calls are harmonic sounds composed of several pulses without inter-pulse interval. It was possible to discern species-specific sounds, but the differences among species could be, in part, explained by the size. Only the sounds of S. elongatus and S. manueli are really distinguishable from the other species. Serrasalmus elongatus differed by having a higher number of pulses and high-pitched fundamental frequency, whereas S. manueli differed by having long pulse periods and a low fundamental frequency. In the framework of this study, acoustic communication cannot be considered as the main driving force in the diversification process of piranhas. Behavioral studies are however needed to clearly understand the eventual role of the calls during the spawning events. [less ▲]

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See detailCoherent backscattering in the Fock space of Bose- and Fermi-Hubbard systems
Engl, Thomas; Dujardin, Julien; Tisserond, Emilie et al

Poster (2016, July)

Coherent backscattering generally refers to a significant and robust enhancement of the average backscattering probability of a wave within a disordered medium, which from a semiclassical point of view ... [more ▼]

Coherent backscattering generally refers to a significant and robust enhancement of the average backscattering probability of a wave within a disordered medium, which from a semiclassical point of view arises due to the constructive interference between backscattered trajectories and their time-reversed counterparts. We recently investigated the manifestation of this wave interference phenomenon in the Fock space of a disordered Bose-Hubbard system of finite extent [1], which can potentially be realized using ultracold bosonic atoms within optical lattices. Preparing the atoms in a well-defined Fock state of the lattice and letting the system evolve for a finite time will, for suitable parameters of the system and upon some disorder average over random on-site energies of the lattice, generally give rise to an equidistribution of the occupation probability within the energy shell of the Fock space that corresponds to the initial energy of the system, in accordance with the quantum microcanonical ensemble. We find, however, that the initial state is twice as often encountered as other Fock states with comparable total energy, which is a consequence of coherent backscattering [1]. Most recently, we showed that this phenomenon also arises in spin 1/2 Fermi-Hubbard rings that involve Rashba hopping terms (which combine inter-site hoppings with spin flips and arise from spin-orbit coupling), for which a newly developed semiclassical theory [2] correctly predicts a coherent enhancement of the occupation probabilities of the initial state and its spin-flipped counterpart. Moreover, performing a global spin flip within this Fermi-Hubbard system will give rise to significant spin echo peaks on those two Fock states, which is again a consequence of quantum many-body interference [3]. The semiclassical predictions of these enhancements and peaks are found to be in very good agreement with numerical findings obtained from the exact quantum time evolution within this Fermi-Hubbard system. [1] T. Engl, J. Dujardin, A. Argüelles, P. Schlagheck, K. Richter, and J. D. Urbina, Phys. Rev. Lett. 112, 140403 (2014). [2] T. Engl, P. Plößl, J. D. Urbina, and K. Richter, Theoretical Chemistry Accounts 133, 1563 (2014). [3] T. Engl, J. D. Urbina, and K. Richter, arXiv:1409.5684. [less ▲]

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See detailPaleoenvironmental implications in the dried lake sediments (Amik Lake, Southern Turkey)
El Ouahabi, Meriam ULg; Hubert, Aurelia ULg; Vander Auwera, Jacqueline ULg et al

Poster (2016, July)

The Amik Basin in the Eastern Mediterranean region has been continuously inhabited since 6000 – 7000 BC. The study focuses on the sedimentary record of the Amik Lake located in the central part of the ... [more ▼]

The Amik Basin in the Eastern Mediterranean region has been continuously inhabited since 6000 – 7000 BC. The study focuses on the sedimentary record of the Amik Lake located in the central part of the basin. Our objective is to constrain major paleo-environmental changes in the area over the last 4000 years and to unravel possible human impacts on the sedimentation. A diverse array of complementary methods was applied on the 6 m long record. Mineralogical (XRD), and geochemical (XRF) analyses were performed. The age of the record is constrained combining radionuclide and radiocarbon dating. A high sedimentation rate of 0.12 cm/yr was inferred at the studied site. The 4000 years (since ~1800 BC) long record shows that significant fluctuations of the lake level and the riverine system inflow into the Amik Lake occurred. The Late Bronze lowstand led to punctual dryings of the lake at the end of the Bronze/Iron Age transition. At that time, the rivers yielded a large terrigenous input linked to strong soil erosion related mainly to deforestation and exploitation of mineral resources. During the Roman and later periods, upland soils were partly depleted and the riverine system completely transformed by channelization (anthropic) that led to a marshification of the Amik Basin [1]. Chemical and mineralogical composition of sediments is quite diversified reflecting the significant geological variation of drainage basins. Periods with strong aggradation linked to major increase in erosion were identified and characterized by high amount of Cr, Ni and Zr. Levels relatively rich in fluorite, richterite, enstatite, hornblende and chrysotile are a result of the erosion of the ophiolitic rocks from the surrounding Amanos Mountains. These levels are interpreted as periods of relatively high physical erosion, while more humid periods led to more intensive weathering. Consequently, the dominance of kaolinite, muscovite/illite and talc indicates a climate with contrasting seasons. During the most recent period a marked increase in terrigenous minerals associated with a rise in dolomite indicates ungoing erosion as well as the drying-out of the lake. [1] T.J. Wilkinson, L. Rayne, Water History, 2, 115-144 (2010). [less ▲]

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See detailGeochemistry and mineralogy approaches to characterize brick and its lake sediments sources: Antioch Roman City (Southern Turkey)
El Ouahabi, Meriam ULg; Hubert, Aurelia ULg; Benjelloun, Yacine et al

Poster (2016, July)

The Roman aqueduct of Antioch-on-the-Orontes (Southern Turkey) is situated close to the Antioch city. This last is located near the Amik Lake (Lake of Antioch) and close to the junction between the active ... [more ▼]

The Roman aqueduct of Antioch-on-the-Orontes (Southern Turkey) is situated close to the Antioch city. This last is located near the Amik Lake (Lake of Antioch) and close to the junction between the active Dead Sea fault and the East Anatolian fault. During the Roman period, the Amik Plain was more densely occupied than at any time in its history [1]. The study focuses on the bricks and the lake sediments characterization in order to determine the source area as well as the technical production used at this period. For this purpose, several bricks were sampled on different parts of the city's aqueducts. Furthermore, a core of about 6 m of sediments was also collected from the dried Amik Lake. The bricks were characterized through a mineralogical (XRD) and chemical (PIXE-PIGE) approaches. Unfired clay fraction remained as inclusion in the brick was separated and then analysed using XRD. Geochemical composition and clay mineralogy were performed on the raw sediments from the Amik Lake in order to compare the source area. Technological test will be performed on the raw clay sediments from the Amik Lake in the purpose to understand the production techniques used at this time. The age of the brick production was previously dated to the Roman Period [2]. The synthesis of all the data attested the Amik Lake sediment as the raw material for the bricks of the aqueduct. Clay mineral composition from the Roman period deposited in the lake is smectite, illite, kaolinite and small amount of mixed-layer clays. The similar clays composition is found in the remained clays on the brick used for the aqueduct construction. Fast and heterogeneous firing practice characterized the manufacturing of these materials due to the rapid need for the materials during the post-seismic repairs after earthquakes that are mentioned in historical written works. [1] J. Casana, Geomorphology, 101, 429-442 (2008) [2] Y. Benjelloun, J. de Sigoyer, J. Carlut, A. Hubert-Ferrari, H. Dessales, H. Pamir, V. Karabacak, Comptes Rendus Geoscience, 347, 170-180 (2015) [less ▲]

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See detailGirls and Math Careers Expectations: Influence of Teacher Support and Motivational Variables
Jaegers, Doriane ULg; Lafontaine, Dominique ULg

Poster (2016, July)

Drawing on the expectancy-value theory, the three basic dimensions of instructional quality and the self-determination theory, this study examines the relation between teacher support, motivational ... [more ▼]

Drawing on the expectancy-value theory, the three basic dimensions of instructional quality and the self-determination theory, this study examines the relation between teacher support, motivational variables, course enrollment and career expectations in the domain of math. Gender differences are also investigated. Teacher support is seen as the fulfilment of the need of relatedness which is defined by the affective and academic quality of the teacher-student relationship. [less ▲]

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See detailPassive flutter suppression using a nonlinear tuned vibration absorber
Verstraelen, Edouard ULg; Gourc, Etienne ULg; Kerschen, Gaëtan ULg et al

Poster (2016, July)

A recent study showed that the addition of a linear tuned vibration absorber could increase the flutter speed of a rigid wing with pitch and flap degrees of freedom by about 35%. However, the absorber was ... [more ▼]

A recent study showed that the addition of a linear tuned vibration absorber could increase the flutter speed of a rigid wing with pitch and flap degrees of freedom by about 35%. However, the absorber was turning the initial super-critical bifurcation into a sub-critical one. This work shows numerically that adding a nonlinear restoring force to the absorber can restore the su- percritical behaviour of the bifurcation and further reduce the post-instability limit cycle amplitude. [less ▲]

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See detailSolo vs. duet in different virtual rooms: On the consistency of singing quality across conditions
Fischinger, Timo; Kreutz, Gunter; Larrouy, Pauline ULg

Poster (2016, July)

Previous research on vocal pitch accuracy revealed insights into the fundamentals of singing. However, most of the research on singing focused on the analysis of single voices, whereas few aYempts have ... [more ▼]

Previous research on vocal pitch accuracy revealed insights into the fundamentals of singing. However, most of the research on singing focused on the analysis of single voices, whereas few aYempts have been made to tackle the challenge of analyzing mulTtrack recordings of singing ensembles. In addiTon, singers have to adjust their way of singing with respect to a given venue’s acousTcal environment (e.g., small room vs. a comparaTvely large space like a church). If it is common that musical performances are greatly influenced by room acousTcs, studies on the effects of room acousTcal features during ensemble singing are rare. In order to invesTgate singing performances across various condiTons, we manipulated the singing condiTon (unison, canon, solo) as well as the acousTcal feedback by applying diverging virtual rooms. Three duets with female singers (N = 6) were asked to sing three different melodies using headset microphones to record each singer separately. Recordings took place in the communicaTon acousTc simulator (CAS) at the House of Hearing (Oldenburg, Germany) to be able to provide different simulated acousTcal spaces (i.e., cathedral, classroom, and dry condiTon) to the singers. ObjecTve measures were performed on each recording and confirmed that the singers sang the melodies with high precision (small pitch interval deviaTons) hardly affected by singing condiTons or by the type of acousTcal feedback. However, the singers tended to driH (larger deviaTons of the tonal center) when singing in canon compared to solo and unison singing. Overall, the analysis of the pitch accuracy showed a general effect of condiTon (i.e., unison, canon, solo), but no general effect of acousTcal feedback and no interacTon between the two variables under study. [less ▲]

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See detailSmart co-phasing system for segmented mirror telescopes
Simar, Juan Felipe ULg; Stockman, Yvan ULg; Surdej, Jean ULg

Poster (2016, June 30)

One of the main challenges in space observations is to observe always fainter and more compact objects. This can be achieved by increasing the telescope diameters. So, increasing the primary mirror ... [more ▼]

One of the main challenges in space observations is to observe always fainter and more compact objects. This can be achieved by increasing the telescope diameters. So, increasing the primary mirror diameters of the telescopes is the challenge solution but it is technically impossible to manufacture monolithic mirrors larger than 10m in diameter. The use of segmented mirrors thus becomes mandatory. This paper describes the results of a light co-phasing setup mounted in laboratory. This setup is able to correct a piston from 200μm to 15 nm based on coarse (200μm to 300nm) and fine (300nm to 15nm) measurement methods. Both measurements are then chained in a feedback system in order to completely co-phase and keep the segments aligned. [less ▲]

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See detailMerging carbon dioxide utilisation, bioresources and CO2-based process for sustainable low carbon footprints polyurethanes
Alves, Margot ULg; Grignard, Bruno ULg; Gennen, Sandro ULg et al

Poster (2016, June 29)

Making plastics more sustainable by valorizing waste CO2 as a cheap, inexhaustible and renewable feedstock is an early stage technology with strong innovation potential that imposes itself as a strategic ... [more ▼]

Making plastics more sustainable by valorizing waste CO2 as a cheap, inexhaustible and renewable feedstock is an early stage technology with strong innovation potential that imposes itself as a strategic driver for developing future low carbon footprints materials and technologies. With a global production estimated to 18 million tons for 2016, polyurethane (PU) is one of the most important polymers in our everyday life with applications in automotive, in building and construction, in coating, in the medical field, as flexible and rigid foams for thermal and/or acoustic insulation. Industrially, PU is produced by step-growth polymerization between di- or polyisocyanates and di- or polyols. However, isocyanates are extremely toxic compounds and made from even more toxic and explosive phosgene. Prolonged exposure to isocyanates vapour results in serious health damages such as skin irritation, asthma or DNA mutation whereas phosgene causes death. Because of the toxicity issues of these compounds associated to drastic changes in the REACH regulations limiting/banning the use of isocyanates, there is a need today to develop new greener and safer alternatives to produce PU. Valorising CO2 as C1 feedstock for producing precursors entering in the synthesis of polyurethanes by a non-isocyanate route (NIPU) is a promising route to solve this challenge the polyurethane sector is facing. Through its global objective focussing on the synthesis of isocyanate-free low carbon footprint foamed materials for thermal insulation this research highlights benefits of merging bio-resources with carbon dioxide transformation and “physical” utilization. The success of the project relies on 3 key steps involving: i) The synthesis of bio- and CO2-sourced cyclic carbonates using new highly efficient organocatalysts: Due to the low reactivity of CO2 versus epoxides, addition of catalysts in the reaction medium is necessary. If lot of catalysts have been developed, their use generally suffers from some drawbacks. Indeed, most of the metal-based catalysts are highly sensitive to hydrolysis and oxidation or/and poorly selective and additionally, some of them are toxic whereas less/non-toxic and eco-friendly organocatalysts such as ionic liquids and halide salts are generally only efficient at very high temperature and pressure, so favouring the decomposition of catalyst. To overcome these limitations, we developed a new highly-efficient bicomponent homogeneous organocatalyst that showed unexpected catalytic activity for the fast (within a few minutes) and selective addition of CO2 onto model epoxides and epoxidized vegetable oils under solvent-free and mild experimental conditions. The use of this powerful dual organocatalyst was further extended to the first organocatalytic coupling of CO2 with less reactive oxetanes to produce hydroxyl telechelic oligocarbonate entering the synthesis of CO2-sourced conventional PUs. ii) The synthesis of sustainable non-isocyanate polyurethanes: Sustainable NIPUs were produced by step-growth polymerization between the so-produced bio- and CO2-sourced cyclic carbonates and biosourced amino-telechelic comonomers derived from linseed fatty acids according to a process compatible with existing industrial infrastructures (extrusion). iii) The foaming of NIPUs: Sustainable foams with thermal insulation were produced by the supercritical CO2 assisted foaming technology. Due to its solubility in polymers, CO2 can replace conventional flammable VOCs and ozone depletion chemical or physical blowing agents such as diazo compounds, hydrocarbons (pentane, isopentane…) or inert gases (nitrogen…) to produce (ultra)lightweight microcellular foams. By finely choosing the CO2 impregnation and the foaming conditions, foams with a thermal conductivity as low as 0.052 Wm-1K-1 were produced. Our study shows that CO2 is not only sequestered in the material for long-term application, but is also valorized as a blowing agent in the production of sustainable thermally insulating NIPU foams. Such low carbon footprints materials will contribute to energy conservation and savings by reducing CO2 emissions [less ▲]

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See detailHolocene paleoclimate reconstructions from belgian continental archives
Allan, Mohammed ULg; VERHEYDEN, sophie; CRUCIFIX, Michel et al

Poster (2016, June 28)

Speleothems and peatbogs presented in Belgium are interesting archives for atmospheric pollution record and climate variability. Both archives are reliable continental environmental archives of high ... [more ▼]

Speleothems and peatbogs presented in Belgium are interesting archives for atmospheric pollution record and climate variability. Both archives are reliable continental environmental archives of high interest due to their dating possibilities and their possibility to preserve multi-proxy records of environmental and climatic dynamics. Combining studies on speleothems and peatbogs from the same area will provide an age-constrained reconstruction of climatic variability at annual resolution for key intervals of the Holocene. The reconstructed precipitation and temperature curves in NW European settings, as proposed in HOPES, are essential to better constrain the Northern Hemisphere climatic record and to test climate models. Our strategy is derived from a comparative study of two continental archives speleothems and peatbogs. Time series of elemental and stable isotope geochemistry will be established for the 2 archives. For peatbog, the reconstructions of temperature (derived from stable C and O isotope), precipitation (derived from humification) and dust flux (from elementary geochemical signature) would track climate changes with subdecadal resolution. As an innovative part, Laser Ablation analyse of elemental geochemistry on impregnated peat section will allow to reach an annual resolution in the dust flux. For speleothems, records of temperature (derived from oxygen and carbon isotopic composition of calcite) and effective rainfall (derived from geochemical ratios) would reach a seasonal resolution. [less ▲]

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See detailMapping and investigating phase anomalies in GPS data onboard Low Earth Orbiters
Wautelet, Gilles ULg; Bruinsma, Sean; Loyer, Sylvain et al

Poster (2016, June 28)

To face important societal challenges like sea level variations, climate change and natural hazards management (tsunami detection, earthquakes, crustal deformations…), modern science rely more and more on ... [more ▼]

To face important societal challenges like sea level variations, climate change and natural hazards management (tsunami detection, earthquakes, crustal deformations…), modern science rely more and more on precise geodesy. Precise Orbit Determination (POD) is of major concern in the frame of altimetry or gravity recovery missions like GOCE or GRACE. Using the GPS receiver onboard, orbits at cm-level accuracy are generally achieved in both kinematic and reduced-dynamic approaches using dual frequency code and phase measurements. GPS data processing generally uses the Ionospheric-Free (IF) combination to get rid of the ionospheric delay, which is varying with the season, latitude, local time and solar activity. However, large discrepancies in the orbit determination are still observed over polar and equatorial regions, which turn into artefacts and errors in the derived scientific products (gravity field, sea surface height…). More precisely, large RMS values are strongly correlated to phase anomalies occurring on GPS receivers: cycle slips, data unavailability or enhanced measurement noise, especially on L2 signal. Phase anomalies are generally observed when the satellite orbit crosses regions where ionospheric scintillations occur, which are defined as rapid fluctuations in phase and amplitude of the GNSS signals. The occurrence of scintillations exhibits large day-to-day variations and depends mainly on geomagnetic latitude, season and local time. At low latitudes, maximum occurrence of scintillations is observed 15-20° on either side of the geomagnetic equator. Scintillations also occur at auroral and polar latitudes, where their intensity increases with increasing geomagnetic activity. This paper aims at detecting, mapping and understanding the phase anomalies experienced by LEO satellites and analyzing their correlation with geomagnetic activity, latitude, season and local time. Several LEO satellites at different altitudes are analyzed (e.g. SWARM, GRACE or JASON), which allows a multi-layer analysis of the underlying ionospheric phenomenon, including scintillation. The latter are generally measured with several indices, like the amplitude index S4 or the phase index SigmaPhi (σφ), which are usually derived from 100Hz measurements performed by dedicated scintillation monitors. In this study, we compute a similar index (called pseudo-σφ) using GPS phase data at 1Hz coming from POD GNSS antenna. A detailed study of the occurrence rate and the severity of pseudo-σφ, together with cycle slips and other spurious phase data, will be performed for different LEO satellites. [less ▲]

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See detailConception of a near-IR spectrometer for ground-based observations of massive stars
Kintziger, Christian ULg; Desselle, Richard ULg; Loicq, Jerôme ULg et al

Poster (2016, June 27)

In our contribution, we outline the different steps in the design of a fiber-fed spectrographic instrument that intends to observe massive stars. Starting from the derivation of theoretical relationships ... [more ▼]

In our contribution, we outline the different steps in the design of a fiber-fed spectrographic instrument that intends to observe massive stars. Starting from the derivation of theoretical relationships from the scientific requirements and telescope characteristics, the entire optical design of the spectrograph is presented. Specific optical elements, such as a toroidal lens, are introduced to improve the instrument’s performances. Then, the verification of predicted optical performances is investigated through optical analyses such as resolution checking. Eventually, the star positioning system onto the central fiber core is explained. [less ▲]

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See detailImpact of cooking and species on intestinal fermentation patterns of vegetables in a humanized in vitro model of the gastro-intestinal tract
Kalala Bolokango, Gaetan ULg; Kambashi Mutiaka, Bienvenu ULg; Njeumen Lemotio, Georges Patrick ULg et al

Poster (2016, June 21)

Obesity and associated pathologies have dramatic consequences on patients’lives as well as high societal costs. Because of the role of intestinal dysbiosis and microbiota make-up on the pathogenesis of ... [more ▼]

Obesity and associated pathologies have dramatic consequences on patients’lives as well as high societal costs. Because of the role of intestinal dysbiosis and microbiota make-up on the pathogenesis of obesity, several strategies such as eating prebiotics and dietary fibre supplements are being investigated to reshape the intestinal microbial communities of obese patients. Beyond supplement, dietary fibre is supplied through plant ingredients in the meals. In the framework of the multidisciplinary research project Food4Gut, the use of vegetables rich in specific targeted dietary fiber, namely fructans, is being scrutinized for its ability to induce positive changes in the intestinal ecophysiology. Because expected effect might differ according the content in dietary fibre and fructans, the soluble:insoluble ratio, as well as the cooking of the vegetables, the fermentation patterns of several vegetables are being investigated in an dual in vitro model combining enzymatic hydrolysis to an in vitro fermentation step using faecal inoculums from humans, to evaluate the performance of gut microbiota, modulation of metabolic functions. Six vegetables were sampled in triplicates (N=3) and steamed for 20 to 30 min.: Jerusalem artichoke, salsify, asparagus, pumpkin, fennel and swede. They were chosen because they display a variety of contents in fructans, soluble (SDF) and insoluble dietaryfibre (IDF). Steamed vegetable samplesand burgers from local fast food restaurants (negative control) were hydrolyzed in vitro why porcine pepsin and pancreatin to mimic digestion in the upper gut and indigested fiber residues were recover using a 6kDa dialysis membrane.Subsequently, in vitro fermentation is being run with independent fecal inoculums from obese and lean patients (N=4). Fermentation kinetics over 24h as well as short-chain fatty acid production and profiles will be compared according to the individual donor and the vegetable species and multivariate analysis will be used to explore the relationships between donor, vegetable species and composition and fermentation patterns. [less ▲]

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See detailNatural radioactivity and elemental composition of sands in the Douala region, Littoral of Cameroon Using Portable XRF and HPGe detector
Guembou Shouop, Cébastien Joel ULg; Ndontchueng Moyo, Maurice; Chene, Grégoire ULg et al

Poster (2016, June 21)

Twenty four sand samples from seven sand quarries alone the Gulf of Guinea, Douala Littoral region of Cameroon, were analyzed using high purity germanium detector and a portable X-ray fluorescence (PXRF ... [more ▼]

Twenty four sand samples from seven sand quarries alone the Gulf of Guinea, Douala Littoral region of Cameroon, were analyzed using high purity germanium detector and a portable X-ray fluorescence (PXRF) spectrometer. A comprehensive study was conducted to determine the natural radioactivity concentrations and the geological provenience of sand samples from seven different quarries sites of the Douala, a popular city, and its surroundings. The radioactivity investigation was performed by using high resolution gamma-ray spectrometry. From the measured gamma-spectra, the average activity concentrations were determined for 226Ra, 232Th, 40K and 235U for a depth of 5–25 cm. Results of this study were compared to values from other locations around the world. X-ray fluorescence spectrometry (XRF) measurements were performed for the quantitative elemental analysis of the sands, revealing the major, minor and trace elements present in the investigated samples. Reference marine and geological sample are used to check precision and accuracy of the equipment for major and minor components. From XRF experimental results it was possible to estimate the geological provenience of the analyzed sands. These data record the radioactivity background levels in sands and could be used as reference information in Cameroon. The comparison of major (Si, Al), minor (K, Ca,Fe), and trace (Ti, Mn, Zr, Rb, Sr) element ratios was made. The results indicate that the levels of Si and Al can be very helpful in subgroup definition and provide useful clues to the raw materials used for glassmaking in Cameroon. [less ▲]

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See detailCapturing fine-level structure using unsupervised clustering method with multiple data types
Chaichoompu, Kridsadakorn ULg; Tongsima, Sissades; Shaw, Philip James et al

Poster (2016, June 17)

Several methods exist to detect shared genetic ancestry or to identify population substructure using SNP-based or haplotype-based information (Price et al. 2006, Lawson et al. 2012). Here, we propose an ... [more ▼]

Several methods exist to detect shared genetic ancestry or to identify population substructure using SNP-based or haplotype-based information (Price et al. 2006, Lawson et al. 2012). Here, we propose an unsupervised clustering method built on the ipPCA algorithm (Intarapanich et al. 2009). Our method supports both ordinal and categorical data, and it can be applied to panels of single locus and/or multiple loci data, or gene-based integrative summaries (Fouladi et al. 2015). Our method involves an iterative process using binary and ternary splits based on multivariate Gaussian mixture modeling of PCs and Clustering EM estimation as in (Lebret et al. 2015). To evaluate its performance, we examined different simulated scenarios of 2-4 populations, 500-8,000 individuals, 5,000-20,000 independent SNPs in HWE, and FST=[0.0007,0.006] (Balding and Nichols 1995), with 100 replicates for each scenario. SNPs were treated as categorical or continuous including ancestry-corrected SNPs. Haplotype-based runs used HapMap 3 data: CHB, CHD, and JPT. In simulated scenarios of extremely subtle structure (FST=[0.0009,0.006]), a population classification accuracy of 92% or greater was obtained, which was superior to ipPCA. Also in case of the HapMap populations, promising results to detect fine structure were obtained. We are convinced that our method has a potential to detect fine-level structure and it will be important in molecular reclassification studies of patients once underlying population structure has been removed. [less ▲]

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See detailEstetrol Attenuates Neonatal Hypoxic-Ischemic Encephalopathy: Preclinical Studies
Tskitishvili, Ekaterine ULg; Nisolle, Michelle ULg; Noël, Agnès ULg et al

Poster (2016, June 17)

Brain hypoxia and ischemia due to systemic hypoxemia and reduced cerebral blood flow (CBF) are the primary causes of neonatal hypoxic-ischemic encephalopathy (HIE) accompanied by gray and white matter ... [more ▼]

Brain hypoxia and ischemia due to systemic hypoxemia and reduced cerebral blood flow (CBF) are the primary causes of neonatal hypoxic-ischemic encephalopathy (HIE) accompanied by gray and white matter injuries occurring in neonates. Perinatal HIE still remains a challenge in perinatal medicine. About 20% of affected newborns die in the postnatal period, and an additional 25% will sustain childhood disabilities. So far no medical treatment provides important neuroprotection against HIE. Studies of new neuroprotective agents in animal models of HIE may have importance for the development of new compounds and treatment strategies for this pathological condition. Estetrol (E4) is a recently described estrogen with four hydroxyl-groups that is synthesized exclusively during pregnancy by the human fetal liver. It has important antioxidative activity. To study the neuroprotective and therapeutic effects of E4 in vivo neonatal HIE model of 7-day-old newborn rat pups was used. Rat pups body temperatures were examined along with their body and brain weights. Brains were studied at the level of the hippocampus and cortex. Intact cell counting and expressions of markers for neuronal cell viability (microtubule-associated protein-2 (MAP-2)), neurogenesis (doublecortin (DCX)) and angiogenesis (vascular-endothelial growth factor (VEGF)) were evaluated by histo- and immunohistochemistry. The serum levels of brain damage markers (S100B and glial fibrillary acidic protein (GFAP)) were measured by ELISA. Our results demonstrate for the first time that E4 has a significant neuroprotective and therapeutic effects. It decreases the early gray matter loss and promotes neuro- and angiogenesis in vivo. Estetrol treatment has no effects on body weight, brain weight or body temperature. Taken together, E4 might become an important safe and physiological substance to treat neonatal HIE. [less ▲]

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See detailLignin as a bio-based flame retardant additive: Pretreatments overview
Istasse, Thibaut ULg; Jacquet, Nicolas ULg; Richel, Aurore ULg

Poster (2016, June 12)

Lignin is a cross-linked phenol polymers from plant cells wall and is the third most abundant organic material after cellulose and hemicelluloses. This substance was studied as a flame retardant for ... [more ▼]

Lignin is a cross-linked phenol polymers from plant cells wall and is the third most abundant organic material after cellulose and hemicelluloses. This substance was studied as a flame retardant for various polymers and represents an interesting opportunity to create more eco-friendly and safer plastics and resins. This poster explains one potential technology to extract lignin: the organosolv treatment. [less ▲]

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See detailWater familiarization testing battery adapted for young children
Vandermeulen, Mary ULg; Schietecatte, Delphine; Delvaux, Anne ULg et al

Poster (2016, June 11)

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See detailFunctional analysis of PEBP genes in root chicory (Cichorium intybus)
Saintmard, Nicolas ULg; Tocquin, Pierre ULg; Périlleux, Claire ULg

Poster (2016, June 09)

Manipulating plant architecture is key to increase crop yield. In this perspective, basic knowledge on the molecular mechanisms regulating plant growth and development will be fundamental for the future ... [more ▼]

Manipulating plant architecture is key to increase crop yield. In this perspective, basic knowledge on the molecular mechanisms regulating plant growth and development will be fundamental for the future of agriculture. Recent progress indicates that a family of plant genes, homologous to POSPHADITYLETHANOLAMINE-BINDING PROTEINS (PEBP) in other eukaryotes, plays critical roles in controlling shoot development traits such as branching, flowering, bud dormancy or tuberization. Very little is known however on the functions of these genes in root development. The current research will attempt to answer this question in the case of Cichorium intybus, a biannual plant cultivated for the extraction of inulin (a polymer of fructose) from its root. Functional analyses will include expression kinetics, complementation tests in Arabidopsis mutants and creation of PEBP- overexpressing or silencing chicory plants. The preliminary steps of the project are the identification of PEBP genes in chicory by in silico analyses, the determination of the time of the storage root initiation and the establishment of a regeneration protocol for the genetic transformation. [less ▲]

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See detailThe Computer in German Literature at the Turn of the Millennium
Dupont, Bruno ULg

Poster (2016, June 09)

This poster shows how the representation of the computer in German literature since 1990 changes the very form and content of literary works. The social importance of the computer challenges the texts on ... [more ▼]

This poster shows how the representation of the computer in German literature since 1990 changes the very form and content of literary works. The social importance of the computer challenges the texts on three levels: their topical organisation, the language used for the transcription of the new reality, and the ideological positioning on new media. [less ▲]

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See detailMALDI-imaging guided microproteomics workflow for biomarker discovery of intra-tumor heterogeneity
Alberts, Deborah ULg; Longuespée, Rémi ULg; Smargiasso, Nicolas ULg et al

Poster (2016, June 09)

Introduction A single tumoral tissue can bear phenotypically different cell populations. This phenomenon called intra-tumor heterogeneity can lead to differential behaviors regarding metastasis seeding ... [more ▼]

Introduction A single tumoral tissue can bear phenotypically different cell populations. This phenomenon called intra-tumor heterogeneity can lead to differential behaviors regarding metastasis seeding and therapy resistance [Zardavas et al., Nature Rev. Clin. Onc. 2015]. MALDI imaging has proven its efficiency for revealing hidden molecular features offering an insight into distinct cellular regions based on their molecular content. Further, proteomics applied to these regions could allow depicting the molecular context associated to particular cells groups and enable the collection of qualitative, quantitative and spatial information for each protein. Methods Breast cancer Formalin Fixed and Paraffin Embedded tissues, from patients whose outcome had been recorded over a period of 10 years, were provided by the department of Pathology of University of Liège. After Citric Acid Antigen Retrieval and trypsin digestion, images were obtained by MALDI-TOF/TOF-MS (Bruker, Germany). From the obtained datasets, segmentation and analytical data analysis were applied using SCiLS (Bruker, Germany) and the cloud software Multimaging (ImaBiotech, France). Small tissue areas were obtained by laser microdissection (LEICA LMD 700, Germany), upon which a combination of chemical processes was applied to ensure optimal protein antigen retrieval, extraction and digestion. Finally, the tissue pieces obtained were analyzed by LC-MS/MS using UPLC Waters Nanoacquity and Thermo Q-Exactive instruments. Preliminary data Based on mathematical calculations for the MALDI imaging datasets of the breast cancer FFPE tissues, Regions Of Interest (ROIs) were detected in a single tumor, revealing intra-tumoral heterogeneity, which can be correlated to the level of aggressiveness of the affliction and to the final prognosis of the patient. We aimed to compare the proteomic profiles of each of the small ROIs. Until today, proteomics applied to tissues composed by a restricted number of cells is quite tedious due to possible tissue losses during their handling. Recently, Longuespée [Longuespée et al., Methods 2015] published a method in order to retrieve the identification of 1400 proteins from microdissected tissue pieces containing only 2700 cells. This whole procedure allowed us to identify a panel of protein that characterizes tissue heterogeneity within a single tumor. This proves the applicability of the combination of MALDI imaging for the discovery of intra-tumoral heterogeneity without a priori, on a mathematical basis, and classical proteomics applied on laser-microdissected tissue samples of very restricted areas. This method will now be applied to several MALDI datasets in order to retrieve commune ROIs and to associate their presence with the information of each patient, such as their prognosis. Those ROIs will then be microdissected and subjected to microproteomic methods that will allow us to retrieve the extensive molecular context associated to bad patient prognosis and/or therapy resistance. The possibility to identify protein/peptide markers will have the power to predict the outcome of the breast cancer patient at the beginning of their treatment, and thus, improve the clinical care for the benefit of the patients. Novel aspect The workflow combines the unique advantages of MALDI imaging for de novo molecular features characterization and LMD-based microproteomics. [less ▲]

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See detailTowards a Digital Philology. Creation, Spread and Apprehension of Knowledge through Digital Scholarly Platforms in Humanities
Mayeur, Ingrid ULg

Poster (2016, June 09)

This contribution aims to present and discuss my thesis project. I plan to study the concrete conditions of production, diffusion and reception of knowledges on digital scholarly platforms in Humanities ... [more ▼]

This contribution aims to present and discuss my thesis project. I plan to study the concrete conditions of production, diffusion and reception of knowledges on digital scholarly platforms in Humanities. This work will especially focus on the four plateforms of the portal OpenEdition: OpenEdition Books, Calenda, Hypothèses and Revues.org. The main problematic is: what are the uses of those platforms, and in what concrete way are they influencing the modes of scientific communication? To start with, I need to highlight the frameworks that structure the digital scholarly texts, that Jeanneret named ‘architexts’ (Davallon & al. 2003, Jeanneret 2014). Such frameworks contribute to configure the digital texts (e. g. with hypertext, flows aggregation), and their uses. Three aspects will then be taken into consideration in my analysis: (I) the articulation of temporal stratums within the plateform: how do archival materials deal with actualities (scientific monitoring, work in progress as grey literature)? What means of contextualization (Treleani 2013) or editorialization (Vitali Rosati 2016) could be given when an old document is used again (e.g. in “epi-revues” that collect scientific papers) ? (II) What are the genres and formats conveyed on the plateform, proper to the Web as blog post, commentary, etc., or still used in other medias as scientific article, advert, etc. (Maingueneau 2013)? (III) Who are the users of those plateforms (researchers, groups, professionals, etc.)? How do they deal with their digital identities? How can they appropriate and diffusing knowledges, by citing, reusing and discussing? How are emerging new ways for research in Humanities, through collective negociation or evaluation, interdisciplinarity – such actions that could be promoted by the technical device of the plateform? This last point will be treated by a philological approach concerning paratexts and quotations (Genette 1982, Compagnon 1979). Other indicators (users’ itineraries, interactions between members, etc.) could also be used, and treated with network’s visualization tool. In summary, this research project aims to explore the means of a digital philology (Crane, Bamann and Jonesin Schreibman 2008; Rastier 2011), not only based on making traditional philology with digital tools (i.e. semantic enrichment of antics or medieval texts), but also on a critical approach of the digital textuality and on an active as well as reflexive contribution from the users in building knowledges. References Davallon, Jean, Marie Després-Lonnet, Yves Jeanneret, Joëlle Le Marec, and Emmanuël Souchier. 2003. Lire, écrire, récrire : Objets, signes et pratiques des médias informatisés. Études et recherche. Paris: Éditions de la Bibliothèque publique d’information. Compagnon, Antoine. 1979. La Seconde main ou le Travail de la citation. Paris: Seuil. Genette, Gérard. 1982. Palimpsestes: La littérature au second degré. Paris: Seuil. Maingueneau, Dominique. 2013. « Genres de discours et web : existe-t-il des genres web ? » In Manuel d’analyse du web en Sciences Humaines et Sociales, 74 93. Paris: Armand Colin. Mounier, Pierre, and Marin Dacos. 2010. L’édition électronique. Paris: La Découverte. Rastier, François. 2011. La mesure et le grain. Sémantique de corpus. Paris: Honoré Champion. Treleani, Matteo. 2014. Mémoires audiovisuelles: les archives en ligne ont-elles un sens? Montréal: PUM. Vitali-Rosati, Marcello. 2016. « What is editorialization? » Sens public, janvier. http://www.sens-public.org/article1059.html, consulté le 10 février 2016. Crane Gregory, David Bamman, and Alison Jonesin Schreibman, “ePhilology: When the Books Talk to Their Readers” in Susan, et Ray Siemens, éd. 2008. Companion to Digital Literary Studies. Oxford: Blackwell Publishing Professional. URL : http://www.digitalhumanities.org/companion/view?docId=blackwell/9781405148641/9781405148641.xml&chunk.id=ss1-4-1&toc.depth=1&toc.id=ss1-4-1&brand=9781405148641_brand. Consulted on 10 fev. 2016.   [less ▲]

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See detailCharacterization of FRD3, a iron and zinc homeostasis actor in Arabidopsis relatives
Scheepers, Maxime ULg; Charlier, Jean-Benoit; Spielmann, Julien ULg et al

Poster (2016, June 09)

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See detailAg/SiO2 and Cu/SiO2 cogelled xerogel catalysts for benzene combustion and 2-butanol deshydrogenation
Mahy, Julien ULg; Claude, Vincent ULg; Tasseroul, Ludivine ULg et al

Poster (2016, June 08)

Tars are recognized as major impurities when biomass is gazified into Syngas (mixture CO + H2) or when the methane reforming was produced from sustainaible reagents [1]. Therefore, fundamental knowledge ... [more ▼]

Tars are recognized as major impurities when biomass is gazified into Syngas (mixture CO + H2) or when the methane reforming was produced from sustainaible reagents [1]. Therefore, fundamental knowledge of catalytic oxidation and deshydrogenation mechanisms can be valuable to develop effective methods to control syngas or methane pollution. A very important concern about cogelled catalysts is the accessibility of the active centers. Because the silver and copper is located inside silica particles, there is a risk that it may not be accessible. In the case of benzene oxidation, it was observed that the specific activity (mol s-1 g-1Ag) of Ag/SiO2 and Cu/SiO2 catalysts increases when the silver or copper loading decreases (Fig. 1). In fact, visual observations by TEM showed that in samples Ag0.25, Ag0.45, Ag1.05 and Cu1.00, there are not silver or copper particles located on silica particles external surface and then the metal dispersion values are greater in these samples. So, it is the proof that Ag and Cu particles located inside the silica particles are accessible for benzene in this catalytic system. In the case of 2-butanol dehydrogenation, the specific activity of Cu/SiO2 catalysts increases when the copper loading increases or when the metal dispersion values decreases (Fig. 2). However, in Cu1.00 sample, copper particles inside silica particles only are observed by TEM. It seems that these metallic particles are accessible for 2-butanol in this catalytic system. [less ▲]

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See detailOn the α-polarization of bacterial suspensions: SIP measurements on four bacterial strains
Pilawski, Tamara ULg; Tappe, Wolfgang; Zimmermann, Egon et al

Poster (2016, June 06)

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See detailMOISTURE CONTENT DETERMINATION OF FREEZE-DRIED PRODUCTS BY NEAR-INFRARED SPECTROSCOPY: A CASE STUDY FOR UNIVERSAL REGRESSION MODEL
Clavaud, Matthieu ULg; Roggo, Yves; Degardin, Klara et al

Poster (2016, June 06)

Karl Fischer titration is the reference method for moisture content determination in the pharmaceutical industry. Near-infrared spectroscopy is considered the most suitable alternative technique. Indeed ... [more ▼]

Karl Fischer titration is the reference method for moisture content determination in the pharmaceutical industry. Near-infrared spectroscopy is considered the most suitable alternative technique. Indeed, NIRS is a safe and fast method which does not require sample preparation. Nevertheless, the development and validation phases are time-consuming. In addition, the NIRS methods presented so far were mostly product specific. The main objective of this study is to highlight that an universal calibration model can be validated for several freeze-dried products in order to speed up the validation time. This objective was led in two steps. A universal model was first evaluated. A calibration set and a validation set were built up with three freeze-dried products. An antibody drug conjugate, a large molecule and a small molecule all packed in sealed vials were used to introduce more variability. Regression methods were then compared in order to optimize the prediction values. [less ▲]

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See detailScreening of mahoran plants for cosmetic applications.
Saive, Matthew ULg; Frederich, Michel ULg; Fauconnier, Marie-Laure ULg

Poster (2016, June 01)

This study’s main aim is to identify plant species showing anti-oxidant, anti-inflammatory and skin whitening properties. A selection of 89 samples from previous infield studies on the traditional uses of ... [more ▼]

This study’s main aim is to identify plant species showing anti-oxidant, anti-inflammatory and skin whitening properties. A selection of 89 samples from previous infield studies on the traditional uses of plants in Mayotte were analyzed. The anti-oxidant activity was assessed using the α, α-diphenyl-β-picrylhydrazyl (DPPH) method developed by Blois [1]. The anti-inflammatory activity and the skin whitening activity were both assessed through the study of inhibition kinetics from specific enzymes: respectively, lipoxygenase (EC 1.13.11.12) due to its important role in the leukotriene pathway and tyrosinase (EC. 1.14.18.1) as it takes part in the melanogenesis pathway. The IC 50 value for each sample and for each activity was obtained using UV/Vis spectrophotometric technics. These IC 50 were then compared with the ones obtained from known molecules found in the literature: namely, (±)-6-Hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (IC50 = 4,388 µM) for the anti-oxidant activity, nordihydroguaiaretic acid (IC50 = 3,5µM) for the anti-inflammatory activity and kojic acid (IC50 = 722 µM) for the anti-tyrosinase activity. The most effective anti-oxidant activity was observed in fresh leaves from Acalypha wilkesiana Müll.Arg. (IC50 = 0,381 g/L) and Leea guineensis G. Don. (IC50 = 0,225 g/L) as well as in dried roots from Litchi chinensis Sonn. (IC50 = 0,346 g/L). All results are expressed in grams of fresh matter. According to the preliminary tests for the-anti-inflammatory and skin whitening activities, the crude extracts from Kalanchoe pinnata Lam. Pers., Litchi chinensis Sonn., Zingiber zerumbet (L.) Sm., Leea guineensis G. Don. and Paullinia pinnata L. are likely to show promising activities. [less ▲]

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See detailSpeech characteristic of French-speaking children with Dysarthria: Pilot study
MacLeod, andrea; Maillart, Christelle ULg; Ancelle, J. et al

Poster (2016, June)

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See detailPhotoionization as a Soft Ionization Source for Comprehensive Two-dimensional GC (GCxGC) and High-Resolution TOFMS
Ubukata, M; Cody, RB; Dane, J et al

Poster (2016, June)

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See detailEducation of instructors of a physical activity program for cancer patients and survivors: planning and evaluation of a poster presentation session
Rompen, Jérôme ULg; Korycki, Marta ULg; Ortmans, Sabine et al

Poster (2016, June)

Introduction The Belgian Foundation against Cancer proposes an adapted physical activity (APA) program for cancer patients and survivors, called Raviva (http://www.cancer.be/raviva-bouger-pour-se-sentir ... [more ▼]

Introduction The Belgian Foundation against Cancer proposes an adapted physical activity (APA) program for cancer patients and survivors, called Raviva (http://www.cancer.be/raviva-bouger-pour-se-sentir-mieux).The activities are supervised by instructors with inconstant trainings and experiences. Contrary to other countries, Belgian APA instructors do not necessarily need to follow specific education programs such those proposed by the ACSM (Schmitz et al., 2010).We were involved in the implementation of a specific training day for in-service Raviva instructors. As it is the case in sport coaches’ education (Erickson et al., 2008), interacting with colleagues seemed to be an appropriate method to improve APA instructors’ skills. Therefore, interactive methods were proposed to be used in order to increase the participants’ interest. The aim of this paper was to describe and analyse a poster presentation session as well as to identify good practices. Methods As part of the training day, the poster presentation session consisted to create groups of 4 to 5 persons and to ask them to imagine and share solutions to specific problems linked with psycho-emotional aspects of the instruction process with Raviva groups. Three methods were used to collect the data: interviews of the organizers (n=4), a questionnaire for all trainees (n=35) and participant observation. Results Examples of good practices were listed and exchanged between the participants. All trainees considered that the poster presentation session was interesting and most of them (94%) reported that appropriate themes were discussed. Moreover, 88.2% of the participants mentioned that they were able to share their experiences. Three expressed negative opinions about the organization. These opinions were supported by all organizers as well as by the observation. Conclusions This educational tool seems to be interesting. However, organizers should plan enough time for such activity. Moreover, the time allocation between each part of the session should be better prepared and controlled. [less ▲]

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See detailTranscranial magnetic stimulation in sleep consciousness
Gosseries, Olivia ULg; Niemienen, Jaakko; Jason, Samaha et al

Poster (2016, June)

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See detailMethodology to fish peptide ligands of nAChRs from Cone snail venoms by MALDI-TOF mass spectrometry
Echterbille, Julien ULg; Gilles, Nicolas; Araoz, Romulo et al

Poster (2016, June)

More than 50,000 of venomous species are currently indexed in the world. Each of their venom is composed of hundreds of toxins which potentially exhibit a high selectivity for membrane receptors such as ... [more ▼]

More than 50,000 of venomous species are currently indexed in the world. Each of their venom is composed of hundreds of toxins which potentially exhibit a high selectivity for membrane receptors such as GPCRs or ion channels. Among them, nAChRs are a target for drug discovery, primarily for treating central nervous system troubles. Therefore, the discovery of pharmacological tools and innovative drugs targeting nAChRs from animal venoms appears as an evidence. This study proposes the use a mass-spectrometry based methodology1 to discover new nAChRs ligands from cone snails venoms, and particularly -conotoxins (a-CTXs), known as potential antagonists of nAChRs2. in few words, Torpedo membranes, containing a high concentration of nAChRs, are incubated with BSA tryptic digests (>100 peptides) doped by small amounts of known a-CTXs. After two hours incubation, free (i.e. containing molecules remaining in solution) and bound (i.e. peptides bound to the membranes) fractions were analyzed with a MALDI-TOF/TOF mass spectrometer. The POC (positive and negative controls) as well as a real screening of Conus ermineus venom are presented. [less ▲]

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See detailMyoclonin-1 modulates the post-translational modification of microtubules
Medard, Laurie ULg; Coumans, Bernard ULg; Lakaye, Bernard ULg et al

Poster (2016, June)

Juvenile myoclonic epilepsy is one of the most common forms of generalized genetic epilepsy. Genetic studies have shown that heterozygous mutations in Myoclonin1 are responsible for 3-9% of clinical cases ... [more ▼]

Juvenile myoclonic epilepsy is one of the most common forms of generalized genetic epilepsy. Genetic studies have shown that heterozygous mutations in Myoclonin1 are responsible for 3-9% of clinical cases worldwide. This protein contains three DM10 domains of unknown function and an EF-hand domain. We have previously demonstrated that Myoclonin1 is a microtubule-associated protein involved in cell division and radial migration during neocortex development. In cells, this protein co-localized with specific structures rich in microtubules (MTs) such as the centrosome, the poles of the mitotic spindle or the motile cilia but not with cytoplasmic MTs. This suggests post-translational modifications (PTM) of MTs may be important for the interaction between Myoclonin1 and MTs. We have co-express the different enzymes catalyzing PTM of MTs with Myoclonin1 in U2OS cell line. With one of these enzymes, we observed a strong increase in PTM in the presence of Myoclonin-1. This suggests that Myoclonin1 may interact with and modulate the activity of this enzyme. By using luciferase complementation assay and pull down experiments, we could demonstrate that it is indeed the case. Interestingly, the effect is observed even when a DM10 domain alone is co-expressed with the enzyme, suggesting for the first time a role for this domain. In conclusion our data suggest myoclonin-1 modulates specific PTM of MTs. This is of prime importance for microtubule dynamic and notably for neuroblast precursor migration during neocortex development. This could be the mechanism that explains why pathological forms of myoclonin-1 affect brain development. [less ▲]

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See detailAnalogical reasoning in children with Specific Language Impairment: Evidence from a scene analogy task
Krzemien, Magali ULg; Jemel, Boutheina; Maillart, Christelle ULg

Poster (2016, June)

Analogical reasoning development maintains a mutual influence with language acquisition: the use of relational labels helps to resolve analogical reasoning tasks (Christie & Gentner, 2014) while ... [more ▼]

Analogical reasoning development maintains a mutual influence with language acquisition: the use of relational labels helps to resolve analogical reasoning tasks (Christie & Gentner, 2014) while analogical reasoning enables the acquisition of new linguistic concepts or structures (Gentner & Namy, 2006). This link has driven some authors to examine the analogical reasoning ability of children with Specific Language Impairment. Those children have poorer analogical reasoning performance than their age-matched peers without language disorders (Leroy et al., 2012 ; Leroy et al., 2014). So, children with SLI seem to have an analogical reasoning weakness which could be linked to their language disorders. Thus, our goal here is to measure the ability of children with SLI to solve analogies, and to compare it to chronological age-matched but also to linguistic age-matched peers without language disorders. Our hypotheses here are the followings: children with SLI have weaker analogical reasoning competence compared to chronological age-matched peers and similar or weaker analogical reasoning competence compared to language-matched peers. To test these hypotheses, we use a scene analogy task composed of pictures of 20 relations (Richland et al., 2006) varying in relational complexity (binary or ternary relations) and in perceptual distraction. Twenty children with SLI are matched to chronological age and linguistic age peers without language disorders. Children with SLI have poorer performance then their age-matched peers but they have similar performance to their language-matched peers. This data reinforces the idea of a link between analogical reasoning and language, also in children with SLI. However, the nature of this link should still be clarified. [less ▲]

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See detailSome results about diametral dimensions
Demeulenaere, Loïc ULg

Poster (2016, June)

The diametral dimension is an important topological invariant, especially in the context of Köthe sequence spaces. This poster presents some results concerning the equality of the diametral dimension with ... [more ▼]

The diametral dimension is an important topological invariant, especially in the context of Köthe sequence spaces. This poster presents some results concerning the equality of the diametral dimension with one of its variants. It is based on a joint work with Françoise Bastin, Leonhard Frerick, and Jochen Wengenroth. Firstly, it gives sufficient conditions to have the equality between the two diametral dimensions for a Fréchet space. Secondly, it provides some examples of spaces verifying these conditions. Finally, it gives a family of Schwartz - or even nuclear - (non metrizable) locally convex spaces for which the two diametral dimensions are different. [less ▲]

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See detailIntegrated microfluidic device for gold nanoparticles synthesis
Emonds-Alt, Gauthier ULg; Malherbe, Cédric ULg; Monbaliu, Jean-Christophe ULg et al

Poster (2016, May 31)

In order to perform the analysis of organic pollutant in trace by Raman spectroscopy, it is necessary to develop SERS substrates, such as noble metal nanoparticles (NPs). The synthesis of gold or silver ... [more ▼]

In order to perform the analysis of organic pollutant in trace by Raman spectroscopy, it is necessary to develop SERS substrates, such as noble metal nanoparticles (NPs). The synthesis of gold or silver NPs is used for analytical applications. It is therefore important to precisely control the synthesis of these SERS substrates to achieve reproducible measurements. Microfluidics is a very attractive technology for the control of the synthesis parameters such as temperature, reaction time and mixing conditions which affect both the size and the morphology of NPs. The synthesis of gold or silver NPs in microreactor is a technique we are already developing in the laboratory. We develop a method for the continuous synthesis of gold and silver NPs in a segmented regime capillary microreactor. The residence time and temperature have a significant effect on the size of the NPs, enabling to prepare different sizes of NPs using the same microreactor and the same precursor solutions. [less ▲]

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See detailPeak dispersion evaluation and optimization in GC×GC
Stefanuto, Pierre-Hugues ULg; Dimandja, Jean-Marie; Focant, Jean-François ULg

Poster (2016, May 30)

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See detailGC×GC-TOFMS for forensic blood VOC profiling
Dubois, Lena ULg; Perrault, Katelynn ULg; Stefanuto, Pierre-Hugues ULg et al

Poster (2016, May 30)

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See detailEstetrol, a natural SERM exhibiting combined estrogenic and anti-estrogenic properties on mammary gland and breast cancer
Gallez, Anne ULg; Gérard, Céline ULg; BLACHER, Silvia ULg et al

Poster (2016, May 30)

The increased risk of breast cancer and thromboembolism in women who take hormone replacement therapy (HRT) is a major public health problem. The discovery of new drugs with better safety profile would ... [more ▼]

The increased risk of breast cancer and thromboembolism in women who take hormone replacement therapy (HRT) is a major public health problem. The discovery of new drugs with better safety profile would provide useful advances for patient care. Estetrol (E4) is a liver friendly promising candidate for HRT. In preclinical and/or clinical studies, E4 has been effective against the main symptoms of menopause from a starting dose of 0.3 mg/kg/day. The aim of this study was to define the impact of E4 on mammary gland and breast cancer development. Our preclinical data show that E4 is less efficient than estradiol (E2) to induce mammary gland growth. Treatment with several concentrations of E4 has shown that E4 did not increase tumor development, when it is used at 0.3 mg/kg/day. However, at 3 mg/kg/day, E4 increased tumor growth similarly to E2 (0.08 mg/kg/day). E4 presents also some anti-estrogenic effects on mammary gland and antitumor activity on breast cancer by decreasing the strong proliferative effect of E2. While ERα is the predominant receptor mediating its effects, the dual weak-estrogenic/anti-estrogenic feature of E4 results from differential signaling pathways activation. Both nuclear and rapid extra-nuclear signaling pathways are necessary for a complete estrogenic effect of E4. However, the antitumor action of E4 is not due to a capacity to antagonize E2-induced nuclear activity. In conclusion, our results support that E4, if it is used in strictly controlled clinical applications, could have no or only limited impact on breast and breast cancer. [less ▲]

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See detailGC×GC-HRTOFMS to better understand cloak-and-dagger activities of Madagascar Mantella frogs
Stefanuto, Pierre-Hugues ULg; Brasseur, Catherine; Cecchini, Harisoa et al

Poster (2016, May 30)

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See detailSingle molecule force spectroscopy on helical foldamers
Devaux, Floriane ULg; Li, Xuesong; Huc, Ivan et al

Poster (2016, May 27)

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See detailSubstrats cérébraux du contrôle proactif et réactif dans le vieillissement non pathologique
Manard, Marine ULg; François, Sarah ULg; Salmon, Eric ULg et al

Poster (2016, May 27)

Les recherches sur le contrôle cognitif proposent l’apparition d’un déclin lié à l’âge dans les capacités de contrôle proactif (forme anticipatoire de contrôle comportemental) alors que le contrôle ... [more ▼]

Les recherches sur le contrôle cognitif proposent l’apparition d’un déclin lié à l’âge dans les capacités de contrôle proactif (forme anticipatoire de contrôle comportemental) alors que le contrôle réactif (forme réactionnelle à la détection d’un conflit) semble rester intact [1]. Ces deux formes de contrôle ont été associées à des aires cérébrales différentes [2], cependant peu d’études ont étudié les effets de l’âge sur les régions cérébrales sous-tendant chacun de ces deux types de contrôle. Pour ce faire, une version adaptée de la tâche de Stroop a été administrée à 16 jeunes (18-30 ans) et 16 adultes (60-75 ans) en IRM fonctionnelle. Cette version de la tâche variait la quantité d’items interférents, permettant la création de trois contextes (Mostly Congruent « MC », Mostly Incongruent « MI » et Neutre) favorisant respectivement la mise en place des deux types de contrôle (réactif = congruent / proactif = incongruent). Les analyses ont été réalisées avec SPM8 (p<.001 non-corrigé). Les résultats comportementaux révèlent un traitement plus rapide de l’interférence dans le contexte « MI » que « MC » pour les jeunes adultes uniquement. Au niveau cérébral, le traitement de l’interférence en MI semble associé à une diminution d’activité (surtout à droite) dans les régions frontales et temporales chez les volontaires âgés par rapport aux plus jeunes, alors qu’en MC, les âgés montrent une augmentation d’activité bilatérale au niveau frontal. Ainsi, les résultats comportementaux montrent que les adultes âgés semblent avoir plus de difficultés à implémenter un contrôle proactif (associé à une diminution d’activité) que les jeunes dans les régions sous-tendant la performance à cette tâche. Cependant, le recrutement supplémentaire de régions frontales observé lors du contexte MC postulé pour favoriser le contrôle réactif, suggère la présence de mécanismes de compensation. Pour conclure, le vieillissement semble affecter de manière différentielle l’activité des régions cérébrales sous-tendant les différents types de contrôle. [less ▲]

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See detailDESIGN OF HIGH-AFFINITY LIGANDS FOR THE BENZOTHIADIAZINE ALLOSTERIC BINDING SITE OF THE AMPA RECEPTORS
Drapier, Thomas ULg; Geubelle, Pierre ULg; Bouckaert, Charlotte et al

Poster (2016, May 26)

L-glutamic acid is the major excitatory neurotransmitter in the brain. It exerts its effects through metabotropic and ionotropic receptors. Among the latter, three subtypes have been identified: NMDA ... [more ▼]

L-glutamic acid is the major excitatory neurotransmitter in the brain. It exerts its effects through metabotropic and ionotropic receptors. Among the latter, three subtypes have been identified: NMDA, AMPA and KA receptors. It is now well established that a deficit in glutamatergic signaling may be responsible for neurological disorders such as mild cognitive impairment, schizophrenia, depression, and ADHD. Enhancement of the signal through positive allosteric modulators of AMPA receptors might be a therapeutic issue for these diseases. These compounds are expected to exert a fine tuning of the signal. Since they require the presence of the endogenous ligand to be active, they are expected to induce less toxicity than agonists. In this context, based on the structure of known allosteric modulators of AMPA receptors such as cyclothiazide and IDRA 21, the Laboratory of Medicinal Chemistry (University of Liège) has developed a series of 1,2,4-benzothiadiazine 1,1-dioxides with high potency as AMPA receptor potentiators. Crystallographic data obtained by the Department of Drug Design and Pharmacology (University of Copenhagen) highlighted those potentiators bind to two contiguous sites at the dimer interface of the ligand binding domain (LBD) of the AMPA receptor1,2. Based on these data, we may expect that the synthesis of dimeric molecules could lead to further improvement in affinity and activity. This assumption was reinforced by docking experiments conducted with virtual examples of dimeric compounds on the GluA2-LBD (collaboration with NAMEDIC). The present work is thus focusing on the preparation of a family of dimeric benzothiadiazine dioxides. Moreover, in collaboration with GIGA-Molecular Pharmacology, we are developing a pharmacological in vitro assay based on the measurement of Ca2+ inflow through a fluorimetric method. This medium-throughput screening will enable the characterization of our new compounds and the validation of our working hypothesis. [less ▲]

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Peer Reviewed
See detailAbnormal bodily experiences in schizophrenia: a phenomenological study
lancellotti, Elisa; Englebert, Jérôme ULg

Poster (2016, May 24)

Our study focuses on Abnormal Bodily Experiences [ABE] in people with schizophrenia. We have created a specific questionnaire for this study – based on the study of Stanghellini et al. (2012) and the ... [more ▼]

Our study focuses on Abnormal Bodily Experiences [ABE] in people with schizophrenia. We have created a specific questionnaire for this study – based on the study of Stanghellini et al. (2012) and the third dimension of the EASE scale (body experiences) (Parnas et al. 2005). Our research follows an analytical method called “empirical-phenomenological”. Our population is made up of 50 schizophrenic subjects. The average age of subjects was 37 years. There are no exclusion criteria regarding gender or control sample. Analyzes are qualitative. We observed that ABE are very present symptoms in people with schizophrenia. Indeed, in our sample, only one patient was asymptomatic. We also observed that all categories and subcategories were present in our sample. These results should help to refine and clarify the diagnosis of schizophrenia and open up significant opportunities for psychotherapeutic dimension. [less ▲]

Detailed reference viewed: 24 (3 ULg)
Peer Reviewed
See detailMaternal sense of competence in a context of precariousness
Halin, Stéphanie ULg; Glowacz, Fabienne ULg

Poster (2016, May 24)

The exercise of parenthood is threatened by the precarious context in which parents and children live. Precariousness is defined by the lack or the absence of basic securities, such as housing, employment ... [more ▼]

The exercise of parenthood is threatened by the precarious context in which parents and children live. Precariousness is defined by the lack or the absence of basic securities, such as housing, employment, financial, emotional security, etc. In such a context, the emotional availability of a parent can be reduced, so that the quality of parent-child interactions decreases and multiple dimensions of the child development are impacted. Therefore, policies of prevention and intervention have been developed in order to overcome the difficulties experienced by parents from birth and, sometimes, from pregnancy. However, little is known about the parenting sense of competence of mother living in such a precarious context, and the possible mediating effect of perceived social support. In this study, we investigate parenting sense of competence in a sample of 38 adult mothers raising alone their children in a context of poverty. Subjects completed the French versions of the “Parenting Sense of Competence Scale (P.S.O.C.)” and the “Social Provisions Scale”, and a socio-demographic questionnaire. Results indicate that, in average, mothers report a high parenting sense of competence (μ=69.18), characterized by a high level of self-efficacy (μ=32.76) and an average level of satisfaction (μ=36.42). Mothers also report low perceived social support (T=41, percentile 21). Results also indicate a significant negative correlate between self-efficacy and the need to feel useful and necessary, while the satisfaction dimension is positively correlated with all the perceived social support dimensions, except from the “need to feel useful” dimension. In conclusion, mothers raising alone their children in a context of poverty report high levels of parenting sense of competence. However, withdrawal and isolation are associated with poorer parental satisfaction. This suggests that the social dimension of poverty is a significant aspect to consider in parenting support policies. [less ▲]

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Peer Reviewed
See detailA phenomenological approach of anorexia nervosa
Minguet, Eugénie; Englebert, Jérôme ULg; Helinski, Adam et al

Poster (2016, May 24)

Introduction: from a phenomenological perspective, anorexic female patients seem to experience difficulties regarding the subjective feeling of their own body (embodiment) and their personal identity ... [more ▼]

Introduction: from a phenomenological perspective, anorexic female patients seem to experience difficulties regarding the subjective feeling of their own body (embodiment) and their personal identity, which lead to an intersubjectivity impairment within social interactions. Following these findings, this study investigates the “body-for-others” concept (Sartre, 1943) and altruistic hypotheses from the ethologist Albert Demaret (1973) in a sample of anorexic female patients. Two main hypotheses are tested: anorexic patients are expected to define themselves mostly through the gaze of others and as more altruistic than control participants. Method: this study included 67 anorexic female patients (based on the DSM-IV criteria) and 246 control female participants. Three self-reported questionnaires were used: the Eating Disorder Inventory: EDI-II of Garner (French version), the Identity and Eating Disorders questionnaire: IDEA of Stanghellini (French version translated and adapted by us) to assess the “body-for-others” concept and 17 complementary items for the altruistic dimension. Mann-Whitney non-parametric tests were used to compare the two groups. Results: results show that anorexic patients obtain higher scores than the control group for the three questionnaires (p<0,001 for all measurements). Discussion: the IDEA questionnaire enriches the knowledge relative to the body-self relationship and the first-person perspective, which is essential for a phenomenological approach. Furthermore, the promising results concerning the altruistic dimension in anorexia nervosa should be evaluated in future research. Nevertheless, a better validity of the items assessing the altruistic dimension is needed. [less ▲]

Detailed reference viewed: 45 (4 ULg)
Full Text
See detailPeptidoglycan fragments separation by CE/LC-MS
Boulanger, Madeleine ULg; Delvaux, Cédric ULg; Far, Johann ULg et al

Poster (2016, May 24)

In Bacillus licheniformis 749/I, the induction of BlaP beta-lactamase relies on a complex regulation system. During this process, the intracellular repressor BlaI is inactivated by a dipeptide coming from ... [more ▼]

In Bacillus licheniformis 749/I, the induction of BlaP beta-lactamase relies on a complex regulation system. During this process, the intracellular repressor BlaI is inactivated by a dipeptide coming from the peptidoglycan (PG) degradation via an “AND Gate” regulation. This regulation involves the cellular stress induced by the beta-lactam, the membrane receptor BlaR1 and the PG turnover. Briefly, the induction occurs when the extracellular domain of BlaR1 is acylated by the antibiotic which leads to a reorganization of the transmembrane segments and the receptor autocleavage. Simultaneously, the beta-lactam partially inhibits the penicillin-binding protein 1 (PBP1), triggering increased PG turnover and accumulation of PG fragments. Some of these fragments could enter in the cytoplasm and undergo enzymatic degradations which lead to the formation of the pro co-activator (tripeptide L-Ala-D-Glu-m-A2pm). This pro co-activator generates the co-activator, the dipeptide D-Glu-m-A2pm. Nowadays the nature and the concentration of PG fragments inside the cytoplasm are unknown. Therefore, the development of different analytical methods is required in order to identify those cytoplasmic fragments. In this poster, three different ways to separate PG fragments are discussed. [less ▲]

Detailed reference viewed: 51 (7 ULg)