References of "Poster"
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See detailIntimate partner violence: Perseverance vs Dropout from treatment programs targeting male batterers
Di Piazza, Laetitia ULg; Kowal, Cécile; Hodiaumont, Fabienne et al

Poster (2016, May 24)

Introduction: The Dropout phenomenon has been studied extensively in general psychotherapy and in more specific domains. Therapeutic programs for male batterers across Europe, United States or Canada also ... [more ▼]

Introduction: The Dropout phenomenon has been studied extensively in general psychotherapy and in more specific domains. Therapeutic programs for male batterers across Europe, United States or Canada also have their share of problems in their attempts to maintain users in treatment. The purpose of this study is to identify potential intrapsychic variables associated with dropout and completion of this kind of treatment. Method: Fifty one male offenders enrolled in a group treatment for domestic violence took part in the study (23 who abandoned and 28 who completed). Before the start of therapy, they were surveyed using questionnaires and structured clinical interview to collect sociodemographic data and to assess specific psychological variables, namely emotional distress (BDI), impulsive behavior (BIS-11), early relationship with their parents (PBI), life events (LEDS) and alexithymia (TAS-20), the inability to experience and express subjective emotions. Results: Correlational analysis showed that age, paternal parenting behaviors and the number of significant events reported in the past six months are the only variables correlated with treatment dropout. The younger the participants, the most likely they were to dropout of the group therapy. Moreover, men who completed treatment reported fewer difficulties in their life and less autonomy support by their father than men who prematurely terminated their therapy. Discussion: The present findings pose a serious challenge for all actors involved in specifics treatment programs. Indeed, if all individuals who committed violent acts have the same intrapsychic variables, how do we predict, especially retain and motivate, the users likely to dropout? [less ▲]

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See detailLife cycle assessment of hemp concret blocks
Groslambert, Sylvie ULg; de Mahieu, Jean-Baptiste; Léonard, Angélique ULg

Poster (2016, May 24)

Buildings notably contribute to global environmental negative impacts due to consumption of both embodied energy and natural resources as well as various emissions during their whole life cycle. It is ... [more ▼]

Buildings notably contribute to global environmental negative impacts due to consumption of both embodied energy and natural resources as well as various emissions during their whole life cycle. It is therefore necessary to develop practices to reduce these impacts, mainly by reducing the part of non-renewable resource in material as well as by ensuring the lowest energy consumption possible during their lifetime. New developments in natural fibres and their use in insulating materials can lead to significant improvement in building environmental impact. For this purpose, assessment of environmental performance is needed to support both the design and the production of (new) fibre based insulation solutions. In this context, the Life Cycle in Practice (LCiP) project helps SMEs to reduce the environmental impacts of their products and services across the entire life cycle. Within the frame of this project, Isohemp (BE) hemp concrete block impact is evaluated in a cradle-to-gate LCA. Functional unit is a pallet of hemp concrete blocks ready for shipping. It represents about 1.3 m³ of blocks. Hemp blocks are made by pressing a mix of hemp shives, hydraulic and hydrated limes, and water. Long term carbon storage due to lime carbonation induces a large benefit in Climate Change (CC) category. The balance of the CC indicator for hemp cultivation is also favorable due to carbon dioxide uptake by the photosynthesis occurring during the plant growth. Life Cycle Assessment of hemp concrete blocks ready to ship has also highlights some improvements that can easily be made at the packaging level in order to lower the global environmental impact and increase the sustainability of this insulation material. Data are processed in SimaPro 8 software, with Ecoinvent 3 and ELCD 3 databases, and analyzed with the CML IA method. This method is compliant with the indicators required by EN15804 standard in order to communicate on the environmental performance of Isohemp blocks. [less ▲]

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See detailWould you care for some integrated care in your fragmented health system? A participatory action research to improve integration between levels of care in a Belgian urban setting.
Belche, Jean ULg; Duchesnes, Christiane ULg; Darras, Christian et al

Poster (2016, May 24)

Integration between levels of care is not facilitated by the Belgian health system. Indeed, patients have uninhibited access to every level of care, there is no gatekeeping system, and no structural ... [more ▼]

Integration between levels of care is not facilitated by the Belgian health system. Indeed, patients have uninhibited access to every level of care, there is no gatekeeping system, and no structural coordination between levels of care. Meanwhile, on one hand, the occurrence of more complex care situations in the ambulatory setting is enhancing the need for coordination while on the other hand, hospitals face financial constraints to provide care in the community. The aim of the research was to organize coordination between levels of care at the local level, in an urban setting. We used the “Local Health System” model (LHS) that aims at integrating hospital and primary care activities for a defined population at the local level. We chose the participatory action research (PAR) methodology and its spiral plan-do-study-act cycles, to ensure the participation and implementation of results by the targeted actors (hospital and local general practitioners (GP) organizations). [less ▲]

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See detailFe2O3 nanoparticle-functionalized N-doped carbon with interconnected, hierarchical porous structures as high-performance electrode for lithium ion batteries
Alkarmo, Walid ULg; Ouhib, Farid ULg; Aqil, Abdelhafid ULg et al

Poster (2016, May 23)

Thanks to their fascinating physical properties such as high surface area, multidimensional electron transport pathways and good mechanical strength, three dimensionally (3D) interconnected carbon porous ... [more ▼]

Thanks to their fascinating physical properties such as high surface area, multidimensional electron transport pathways and good mechanical strength, three dimensionally (3D) interconnected carbon porous frameworks have emerged as attractive materials for various electrochemical energy storage/conversion devices, including Li-ion batteries (LIBs), Li−O2 batteries, Li−S batteries, supercapacitors, and fuel cells. A hierarchically structured macro- and mesoporous N-doped carbon with dispersed Fe2O3 nanoparticles (NDC@Fe2O3) is prepared by thermal treatment of a novel composite composed by PMMA particles decorated by graphene oxide (GO), PPy and iron salts. The NDC@Fe2O3 composite exhibited high surface area with a hierarchical pores structure. Integrated as a lithium ion battery anode, NDC@Fe2O3 exhibited high reversible capacity of 930 mA h/g over 200 cycles. The combination of Fe2O3 nanoparticles with porous carbon to form hybrid anode has been an efficient way to maintain the electronic integrity of the whole electrode since the carbon acts as a buffer layer to accommodate the volume variation and to provide multidimensional electron transport pathways during the charge/discharge process. [less ▲]

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See detailPolyphosphoester containing amphiphilic block copolymers as drug nanocarriers
Yilmaz-Ergül, Zeynep ULg; Vanslambrouck, Stéphanie; Thiry, Justine ULg et al

Poster (2016, May 23)

The design of drug delivery systems (DDS) often requires biodegradable and biocompatible materials that allow safe retention and controlled release of the drug. In this respect, poly(ethylene oxide)-b ... [more ▼]

The design of drug delivery systems (DDS) often requires biodegradable and biocompatible materials that allow safe retention and controlled release of the drug. In this respect, poly(ethylene oxide)-b-polyphosphoester amphiphilic block copolymers are known to self-assemble into polymer micelles when placed in water are appropriate drug carriers. In this work, an unsaturated alkene side-chain was introduced on the cyclic phosphate monomer according to a one-step reaction followed by its organocatalyzed polymerization initiated by a poly(ethylene oxide) macroinitiator. After self-assembly into water, the micelles were cross-linked by UV irradiation. Then, these cross-linked micelles have been loaded by doxorubicin, which is a drug to use in cancer therapy. We observed that the doxorubicin loading increased with the number of double bonds on the polyphosphate block of non-cross-linked micelles. This diblock amphiphilic copolymer bearing pendant unsaturations appears thus particularly promising candidate to build micellar drug delivery systems for intravenous injection. [less ▲]

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See detailTuning morphology and surface properties of emulsion-templated porous polymers by controlled radical polymerization
Mathieu, Kevin ULg; Jérôme, Christine ULg; Debuigne, Antoine ULg

Poster (2016, May 23)

Macroporous polymer monoliths with interconnected structures have attracted considerable interests in the last decades and sustain many applications in the fields of supported catalysis, chromatography ... [more ▼]

Macroporous polymer monoliths with interconnected structures have attracted considerable interests in the last decades and sustain many applications in the fields of supported catalysis, chromatography, microfluidic, water purification, membrane separation, tissue engineering, to name but a few. A very popular and straightforward synthetic approach for such open-cell polymers is the High Internal Phase Emulsion (HIPE) polymerization method. The latter consists in three steps: (i) stabilization of an emulsion in which an internal phase with a volume fraction higher than 74% is dispersed within a minor continuous phase containing a polymer network precursor, (ii) curing of the polymer phase by polymerization or crosslinking reactions, (iii) removal of the internal phase to release the porosity. The surface properties and morphology of the polyHIPEs are important features that must be controlled and adjusted for each applications. In this context, we prepared by controlled radical polymerization a series of well-defined amphiphilic copolymers having different hydrophilic-lipophilic balance (HLB) and chain-ends, used it as stabilizers for the emulsion-templated polymerizations and demonstrated the crucial effect of the structure of the macromolecular surfactant on the morphology of the polyHIPEs. Finally, the physical and chemical anchoring of the macromolecular surfactants at the surface pores were also considered for tuning the surface properties of the porous monoliths. [less ▲]

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See detailSynthesis of CO2-sourced hydrogels by using the non-isocyanate polyurethane (NIPU) chemistry
Gennen, Sandro ULg; Grignard, Bruno ULg; Thomassin, Jean-Michel ULg et al

Poster (2016, May 23)

Polyurethane (PUs) is one of the most important polymers and finds applications as elastomers, coatings, adhesives and sealants for automotive or construction. PU is also a material of choice in the ... [more ▼]

Polyurethane (PUs) is one of the most important polymers and finds applications as elastomers, coatings, adhesives and sealants for automotive or construction. PU is also a material of choice in the biomedical domain due to its good biocompatibility, biodegradation and mechanical properties. Especially, PUs hydrogels have been developed in the last years for biomedical applications such as soft contact lenses, wound dressing, drug delivery systems and scaffolds for tissue engineering. Traditionally, PUs are synthesized by a step-growth polymerization between diols and diisocyanates. Because of toxicity issues and a possible interdiction of isocyanates, we focused on developing new PU hydrogels using a non-isocyanate route (Figure 1). The polyurethanes formed by this route are called NIPU (for Non-Isocyanate PolyUrethane). Firstly, chemically cross-linked NIPU gels were synthesized by solvent-free polycondensation between a hydrophilic CO2-sourced polyethyleneglycol bi-cyclic carbonate and a diamine in the presence of a crosslinker. Then, NIPU gels were swelled in water till water equilibrium before characterization of their mechanical properties by compression tests. The influence of the cross-linking ratios (diamine/crosslinker ratio) and diamine structure on the swelling and the compression properties were studied. To reinforce the compression properties of NIPU hydrogel (increase in stress at break, strain at break and compression modulus), a nanofiller was dispersed in the cyclic carbonate/diamine/crosslinker formulation prior to polymerization. For the first time, nanocomposite NIPU hydrogels with high water contents (up to 80%) and good compression properties have been prepared by using low clay content. [less ▲]

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See detailSynthesis of novel poly(vinylamine)-based copolymers with controlled compositions
Dréan; Guégan, Philippe; Detrembleur, Christophe ULg et al

Poster (2016, May 23)

Metal binding, pH sensitivity and polyelectrolytes complexation are key characteristics of amine-containing polymers. Among them, poly(vinylamine)s presenting high amine densities are particularly useful ... [more ▼]

Metal binding, pH sensitivity and polyelectrolytes complexation are key characteristics of amine-containing polymers. Among them, poly(vinylamine)s presenting high amine densities are particularly useful in many fields such as coatings , water purification and gas membrane separation. The properties of such polymers strongly depend on the nature of the amines and can thus be adjusted by incorporating different types of amines along the backbone. In this perspective, we developed a strategy for synthesizing poly(vinylamine)-based (co)polymers containing primary and secondary amines as well as imidazole moieties in predictable proportions. First, radical (co)polymerizations of N-vinylacetamide, N-methylvinylacetamide and vinylimidazole were performed followed by deprotection of the amine functions via acidic hydrolysis of the pendant amides. We determined the reactivity ratios of each comonomer pairs and developed the corresponding Skeist’s model, allowing the prediction of the copolymer compositions and distributions. Following this straightforward approach, novel amine-containing copolymers with predictable and precise compositions were made available and should contribute in the future to the development of the above-mentioned applications. [less ▲]

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See detailA novel unsupervised clustering approach with multiple data types to reveal fine-level structure
Chaichoompu, Kridsadakorn ULg; Tongsima, Sissades; Shaw, Philip James et al

Poster (2016, May 21)

Introduction: Several methods exist to identify population substructure that is due to shared genetic ancestry or regional proximity. These may be SNP-based or haplotype-based (Price et al. 2006, Lawson ... [more ▼]

Introduction: Several methods exist to identify population substructure that is due to shared genetic ancestry or regional proximity. These may be SNP-based or haplotype-based (Price et al. 2006, Lawson et al. 2012). Here, we present a flexible unsupervised clustering approach that is built on the ipPCA machinery (Intarapanich et al. 2009). Methods: Our method supports both numeric and categorical data, and can be applied to panels of SNPs and/or haplotypes, or gene-based integrative summaries (Fouladi et al. 2015). Unlike ipPCA, our method involves an iterative process using binary and ternary splits based on multivariate Gaussian mixture modeling of PCs and Clustering EM (CEM) estimation as in (Lebret et al. 2015). To assess performance, we considered different simulated scenarios of FST=[0.0005,0.006], 5,000-20,000 independent SNPs in HWE, 500-8,000 individuals, and 2-4 populations (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-JPT (FST=0.007) and CEU-TSI (FST=0.004). Result and Conclusion: In simulated scenarios of extremely subtle structure (FST=[0.0009,0.002]), a population classification accuracy of 92.56% or greater was obtained, which was superior to ipPCA. Promising results to detect fine structure were also obtained in case of the HapMap populations. We believe that the ability of our approach to detect subtle structure, including outlier individuals, will be important in molecular reclassification studies of patients from whom underlying population patterns have been removed. Grants: KC and KVS acknowledge FNRS, AS acknowledges ANR, ST acknowledges NSTDA, and PJS acknowledges TRF. [less ▲]

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See detailCharacterization of the impact of tillage on the root development and distribution of crop residues of a winter wheat crop by the use of NIR hyperspectral imaging
Fraipont, Guillaume ULg; Eylenbosch, Damien ULg; Fernández Pierna, Juan Antonio et al

Poster (2016, May 20)

The objectives of the study were to show the impact of tillage and crop residues management on the distribution of crop residues and root system of a winter wheat crop in the 0-30 cm soil profile.This ... [more ▼]

The objectives of the study were to show the impact of tillage and crop residues management on the distribution of crop residues and root system of a winter wheat crop in the 0-30 cm soil profile.This poster shows the results obtained during one crop year (2011-2012). This study is allowed by a rapid and innovative method of root system quantification based on the near infrared hyperspectral Imaging. [less ▲]

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See detailHuman in the forest: Long-term interactions, lifestyle and ecosystem services in Central Africa
Gillet, Pauline ULg; Lhoest, Simon ULg; Morin-Rivat, Julie et al

Poster (2016, May 20)

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See detailImproving pose estimation by building dedicated datasets and using orientation
Azrour, Samir ULg; Pierard, Sébastien ULg; Van Droogenbroeck, Marc ULg

Poster (2016, May 19)

Markerless pose estimation systems are useful for various applications including human- computer interaction, activity recognition, security, gait analysis, and computer-assisted medical interventions ... [more ▼]

Markerless pose estimation systems are useful for various applications including human- computer interaction, activity recognition, security, gait analysis, and computer-assisted medical interventions. They have attracted much interest since the release of low-cost depth cameras such as Microsoft’s Kinect camera. Shotton et al. and Girshick et al. pioneered tractable methods that infer a full-body pose reconstruction in real-time. Despite this technological breakthrough, the accuracy of human pose estimation from single depth images remains insufficient for some applications. Our work aims at building a simulation environment to create images databases suited for any camera position and improving the mainstream machine learning-based pose estimation algorithms. [less ▲]

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Peer Reviewed
See detailChaotic Bohmian trajectories for stationary states
Cesa, Alexandre ULg; Martin, John ULg; Struyve, Ward

Poster (2016, May 18)

We study the possibility of chaos for the Bohmian dynamics when the wave function is stationary. Examples of stationary wave functions are given for which there is chaos, as demonstrated by numerical ... [more ▼]

We study the possibility of chaos for the Bohmian dynamics when the wave function is stationary. Examples of stationary wave functions are given for which there is chaos, as demonstrated by numerical computations, for one particle moving in 3 spatial dimensions and for two and three entangled particles in 2 dimensions. What is important for the amount of chaos is the overall complexity of the wave function. Some simple measures that partly capture the complexity of the wave function are considered: the participation ratio and different measures of entanglement. We find that these measures often tend to correlate to the amount of chaos. However, the correlation is not perfect, because the measures do not depend on the intrinsic complexity of the states of a given basis. [less ▲]

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See detailAnticoherence of spin states with point-group symmetries
Baguette, Dorian ULg; Damanet, François ULg; Giraud, Olivier et al

Poster (2016, May 18)

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See detailL'ordinateur dans la littérature allemande au tournant du millénaire
Dupont, Bruno ULg

Poster (2016, May 18)

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See detailSuper- and subradiance from indistinguishable atoms with quantized motion
Damanet, François ULg; Braun, Daniel; Martin, John ULg

Poster (2016, May 18)

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See detailDevelopment of a hydrogen maser in the TE111 mode
Van Der Beken, Emeline ULg; Léonard, Daniel; Counet, Arnaud et al

Poster (2016, May 18)

We present the recent progress in the development of a hydrogen maser in the unusual TE111 mode. In contrast to standard hydrogen maser that exploits the TE011 mode, the TE111 mode allows one to design ... [more ▼]

We present the recent progress in the development of a hydrogen maser in the unusual TE111 mode. In contrast to standard hydrogen maser that exploits the TE011 mode, the TE111 mode allows one to design hydrogen masers with significant reduced dimensions which represents a huge benefit for space applications and in particular for the global positioning system. We present in details the different parts of our model : cavity with a thin Teflon sheet, magnetic shielding, temperature control of the maser... [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, May 18)

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 weaker amplitude, half period oscillations on transmission, namely the Aronov-Al’tshuler-Spivak (AAS) oscillations. The competition between disorder and interaction leads to a flip of the transmission at the AB flux φ = π. This flip could be a possible preliminary signature of an inversion of the coherent backscattering (CBS) peak. Our study paves the way to an analytical description of the inversion of that peak. [less ▲]

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See detailInsights gained from metagenomic sequencing of apple fruit surface (cv. Pinova)
Angeli, Dario; Massart, Sébastien ULg; Sare, Abdoul Razack ULg et al

Poster (2016, May 17)

Plant microbial communities (microbiota) living at the surface of fruit have been the source of the majority of biocontrol agents (BCAs). Despite this interest, their role as a community has been poorly ... [more ▼]

Plant microbial communities (microbiota) living at the surface of fruit have been the source of the majority of biocontrol agents (BCAs). Despite this interest, their role as a community has been poorly studied so far. They holistic study was an unattainable objective due to the absence of techniques to survey microbial communities and their evolution. The recent developments in high-throughput sequencing (HTS) have now enabled the holistic analysis of the microbiota genomes. A pioneering assay has been carried out to get insight into the microbiota of apple surface through metagenome sequencing. Apple from Pinova cultivar have been sampled in orchard and the microbiota isolated. After DNA extraction, the HTS assay generated 14.5 Gbases which were assembled in 133,888 contigs. These contigs provided useful information on taxonomic composition of the microbiota. A total of 1398 bacterial species and 397 fungal species have been identified. Among them, 22 species corresponded to known apple pathogens (Penicillium expansum, Penicillium spp, Botrytis cinerea, Monilinia fructicola, Nectria haematococca, Glomerella cingulate, G. graminicola, Alternaria alternate, Alternaria brassicicola, A. citri, A. longipes, A. solani, A. tenuissima, Fusarium solani, F. oxysporum, F. culmorum, F. lateritium, Mucor circinelloides, M. hiemalis, F. racemosus, Venturia inaequalis, Cladosporium cladosporioides). In addition, several contigs were assigned to species or genus of known BCA strains like Pichia canadensis, Bacillus sp., Debaryomyces hansenii, Aureobasidium pullulans and Pantoea vagans. These results will be discussed. In any case, these results underline a very diverse microbial community whose role needs to be characterized. In this line, the functional analysis (gene function determination) of the contigs is ongoing. [less ▲]

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See detailCan tropical basil be integrated in vegetable crop pest management?
Yarou, Boni Barthélémy ULg; Verheggen, François ULg; Heuskin, Stéphanie ULg et al

Poster (2016, May 17)

To address human and environmental health issues related to the use of synthetic pesticides, it is important to explore other ecological pest management approaches. Within this context, a study was ... [more ▼]

To address human and environmental health issues related to the use of synthetic pesticides, it is important to explore other ecological pest management approaches. Within this context, a study was conducted to evaluate the toxic and repellent effect of Ocimum gratissimum L. (Lamiaceae) on Myzus persicae S. (Aphididae). The toxicity of O. gratissimum essential oil (EO) was evaluated on M. persicae comparing 3 concentrations (0.001%; 0.01% and 0.1%) to a control (15% sucrose). Mortality rate and fecundity were assessed for each concentration. The observations were made daily, for 4 days, on 12 replicates per treatment. To test the repellent effect of O. gratissimum plants, 2 treatments were compared: a group of 8 Amaranthus cruentus L. (Amaranthaceae) plants with 1 plant of O. gratissimum in the middle and a group of 9 A. cruentus plants (control). The distribution of aphids was analyzed 12 days after the middle plant infestation (20 aphids per plant) for each treatment (6 replicates per treatment). O. gratissimum EO was found toxic from a concentration of 0.01%, with a mortality rate of 34% versus 12% for the control ; The fecundity felt from 30 larvae after 4 days (control) to 15 larvae for the 3 doses of the EO. The analysis with the generalized linear mixed model with Poisson error distribution followed by Turkey test (5 %) showed that EO is significantly more toxic than the control, both for mortality and fecundity (p <0.001). In association test, the population of M. persicae (15 aphids per plant) was significantly (p<0,001) lower when A. cruentus plants was associated with O. gratissimum plant than with the control (22 aphids per plant). Furthermore, the population increases gradually as one moves away from the infestation point in association test whereas it decreases in the control. With regards to these results, it appears that O. gratissimum has biocide effects on M. persicae. This plant may be used in an integrated pest management strategy in the production of vegetable to reduce the use of synthetic pesticides and avoid chemicals residues. [less ▲]

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See detailCharacterization and biocontrol properties of Lactuca sativa rhizosphere microbiota in an aquaponic system
Stouvenakers, Gilles ULg; Massart, Sébastien ULg; Jijakli, Haissam ULg

Poster (2016, May 17)

Aquaponics is an integrated recirculated system that combines aquaculture and hydroponic plant production. The dissolved nutrients generated by the fish rearing after bacterial activities are used by the ... [more ▼]

Aquaponics is an integrated recirculated system that combines aquaculture and hydroponic plant production. The dissolved nutrients generated by the fish rearing after bacterial activities are used by the plants for their growth. This uptake reduces the accumulation of some molecules which allow a longer water recirculation. When comparing growth conditions between aquaponics and hydroponics, we observed much lower concentration of several key nutrients in aquaponics. Nevertheless, several experimentations report similar or better yield in aquaponics compared with hydroponics. One explanation of this phenomenon could be linked to microbial actions. Nowadays, microorganisms related to aquaculture and hydroponics are well characterized but very little is known about the microbiota associated with aquaponic system. The first aim of this study is to characterize the rhizosphere microbiota (metagenomics) of lettuces growing in an aquaponics system. A NGS approach targeting the 16S rDNA will be carried out to evaluate the bacterial composition and diversity. The second aim is to assess the resistance of aquaponics lettuces following a pest introduction. Yields, symptoms and microbial changes due to the pest will be recorded and analysed to determine if aquaponics systems provide a better plant protection than hydroponics. Depending on the results, the final steps will be to identify the optimal conditions for the management of the potential beneficial microbiota or isolate a beneficial microorganism. [less ▲]

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See detailVortex Image Processing (VIP) package for high-contrast direct imaging
Gómez González, Carlos ULg; Absil, Olivier ULg; Wertz, Olivier ULg et al

Poster (2016, May 16)

VIP is a Python instrument-agnostic toolbox featuring a flexible framework for reproducible and robust data reduction. VIP currently supports three high-contrast imaging observational techniques: angular ... [more ▼]

VIP is a Python instrument-agnostic toolbox featuring a flexible framework for reproducible and robust data reduction. VIP currently supports three high-contrast imaging observational techniques: angular, reference-star and multi-spectral differential imaging. The code can be downloaded from our git repository on Github: http://github.com/vortex-exoplanet/VIP [less ▲]

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

Poster (2016, May 13)

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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, May 13)

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 detailTailoring γ-Al2O3 supports with specific silicon precursors
Claude, Vincent ULg; Vilaseca, Miriam; Heinrichs, Benoît ULg et al

Poster (2016, May 13)

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See detailSpatial Analysis of the Landslide Risk in the Cameroon Volcanic Line (CVL)
Mukenga, Williams ULg; Havenith, Hans-Balder ULg; Medjo Eko, Robert et al

Poster (2016, May 12)

Landslides are recognized as important geomorphologic process due to the role they play in the development of hill slopes in mountainous regions, and to related socio-economic consequences. There are many ... [more ▼]

Landslides are recognized as important geomorphologic process due to the role they play in the development of hill slopes in mountainous regions, and to related socio-economic consequences. There are many causes of landslides and their distribution varies with the changing conditioning factors. Slope stability depends on a number of causative factors and the knowledge of these variables can help to predict the type of landslide expected in the future. In this study, past landslide activity and triggering factors will be used to assess mass movement hazards along the Cameroon Volcanic Line (CVL). Spatial aspects will be studied in terms of landslide susceptibility maps that are important for development planning and disaster management. The current synthesis of landslide susceptibility map at regional scale is based on a literature review to inventory passed mass movement impacts, on the detection of landslide features from Google Earth imagery, combined with spatial analysis using Geographical Information Systems (GIS) and remote sensing. One of the most critical stages in landslide susceptibility mapping is the selection of landslide pre-conditioning, conditioning and triggering factors and weighting of the selected causative factors in accordance to their influence on slope stability. Google earth helps for delineating past (but recent) and present landslide activity whereas GIS is suitable when deriving static factors (slope aspect and surface curvature) and time-dependent factors (annual precipitation and changing groundwater table level) that are needed to produce landslide susceptibility maps. Landslide susceptibility mapping is based on the assumption that future landslides will occur under similar circumstances as past and present mass movements. Different methods, including the weight of evidence methods, are used for landslide susceptibility mapping along the Cameroon Volcanic line, as the area is known to be highly susceptible to landslide occurrences. [less ▲]

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See detailMolecular detection of single nucleotide polymorphisms on whole blood without DNA extraction
Detemmerman, L.; BOEMER, François ULg; SEGERS, Karin ULg et al

Poster (2016, May 12)

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See detailOzone concentration and CO2 flux monitoring in a belgian forest
Hurdebise, Quentin ULg; Bergmans, Benjamin; Aubinet, Marc ULg

Poster (2016, May 11)

Temperate forests, as other ecosystems and oceans, mitigate the accumulation in the atmosphere of CO2, the main responsible for the current climate change. It is, therefore, a necessity to understand how ... [more ▼]

Temperate forests, as other ecosystems and oceans, mitigate the accumulation in the atmosphere of CO2, the main responsible for the current climate change. It is, therefore, a necessity to understand how these forests react and will react in a changing environment. That requires long-term monitoring of the environment. Tropospheric ozone is one parameter to monitor as it affects the forest by inducing oxidative stress once inside the leaves. Using 16 years of continuous data from an air quality monitoring station managed by the ISSeP (Institut Scientifique de Service Public) located in a mixed forest in east Belgium, we identified ozone concentration extreme events and we investigated their occurrence frequency as well as their relation with climatic variables and air components. As variables are subjected to daily, yearly and inter-annual dynamics, anomalies were used to detect extreme events. To obtain anomalies, we removed the previously mentioned dynamics from half-hourly raw data. Daily and yearly dynamics were removed first and explained 40% of the variability observed in half-hourly ozone concentrations. Then, the inter-annual dynamic was obtained by computing the yearly mean of the residuals, it accounted for 2% of the variability observed. A significant (p<0.01) decreasing trend was observed for these residuals. Determining if that trend is site specific or regionally observed can be done by applying the same analysis to the other sites from the network managed by the ISSeP. No significant trend in the yearly frequency and intensity of extreme events was observed. We used a stepwise regression to identify the variables that explain these extreme events. Significant relations were found between ozone concentration and climatic variables (vapor pressure deficit, temperature, radiation and wind direction) as well as other air components concentration (NO2, NO, NOX, CO). The next step will be to estimate the forest capacity to uptake ozone in order to predict ozone-induced damage and compared it to the CO2 uptake and H2O emissions measured in an ICOS site, the Vielsalm Terrestrial Observatory, located in the same forest at less than 300 meters from the air quality monitoring station. [less ▲]

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See detailAssociation of Targeted metagenomic analysis and classical microbiology for Clostridium difficile detection and microbial ecosystem mapping of surfaces hands and foodstuffs in a meat processing plant
Rodriguez Diaz, Cristina ULg; Oukbir, Meriem; Taminiau, Bernard ULg et al

Poster (2016, May 11)

INTRODUCTION Zoonoses are infectious that can be transmitted between animals and humans through direct contact, close proximity or the environment. Since domestic and food animals frequently test positive ... [more ▼]

INTRODUCTION Zoonoses are infectious that can be transmitted between animals and humans through direct contact, close proximity or the environment. Since domestic and food animals frequently test positive for the bacterium, it seems plausible that C. difficile could be zoonotic. PURPOSE This study aimed to determine the prevalence and the epidemiology of C. difficile in cattle farms and the possible spread of the bacterium among animals and farmers. METHODS A total of 176 faecal samples of cattle were collected from 5 different Belgian farms. A stool sample of each farmer was also requested. Detection of C. difficile was performed by classical culture on C. difficile selective medium (cycloserine cefoxitin fructose cholate). Isolates were characterised by PCR-ribotyping and Genotype Cdiff test (Hain Lifescience), which allows the detection of all toxin genes, mutations in gyrA gene and the deletion in the regulator gene tcdC. RESULTS C. difficile was detected in 14/178 (7.9%) animal samples. Isolates were grouped into five different types, including PCR-ribotype 015. All of them were identified as toxigenic. In contrast, none of the 5 farmers studied were positive for the bacterium. SIGNIFICANCE Results obtained indicate that PCR-ribotypes commonly isolated from hospitalised patients are also present in cattle, indicating an animal reservoir. However, a zoonotic transmission could be not demonstrated in the farms studied. [less ▲]

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See detailAccurate measurement of radius evolution as a function of direction in 3D images
Plougonven, Erwan ULg; Hubert, Julien ULg; Collin, Frédéric ULg et al

Poster (2016, May 11)

Very often the reason for using of X-Ray tomography in a research project is to measure the evolution of some geometrical characteristic. The sought characteristic may be explained in simple words like ... [more ▼]

Very often the reason for using of X-Ray tomography in a research project is to measure the evolution of some geometrical characteristic. The sought characteristic may be explained in simple words like size, shape, or distance, but in practice measures based on these notions can have a complex implementation. We present a simple problem, measuring the evolution of radius in a cylindrical sample (a common shape for sample preparation for tomography) and how this value differs according the direction in which we look, when such evolution is known to be anisotropic. The solution is not unique, but we show that a naïve manual approach are not accurate enough, and how even a simple geometric notion such as radius needs a thorough definition in relation to its applicability to 3D image analysis. We extend the argument to how a good understanding of the notions and algorithms used in the quantification of geometrical characteristics can directly affect the pertinence and representativity of the results. [less ▲]

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See detailThe influence of COMT single nucleotide polymorphism (rs4680) on the neural substrates of working memory representations maintenance in healthy aging
Manard, Marine ULg; François, Sarah ULg; Bahri, Mohamed Ali ULg et al

Poster (2016, May 10)

The COMT val108/158met polymorphism was associated to the dopaminergic modulation in the brain, and therefore stimulated research on its influence for cognitive functioning and particularly working memory ... [more ▼]

The COMT val108/158met polymorphism was associated to the dopaminergic modulation in the brain, and therefore stimulated research on its influence for cognitive functioning and particularly working memory. First, a general advantage of carrying the met allele was reported. However, many studies used tasks that did not allow efficiently assessing the contribution of manipulation and maintenance processes in working memory, leading to divergent results, in both young and older populations, resulting in debates about the exact phenotypic effect of the COMT polymorphism. Using fMRI, this study was designed to assess the potential effect of the COMT polymorphism on age-related differences in working memory representations maintenance abilities (Sternberg paradigm). Partial Least Squares method was used to determine the brain-behavior correlations at low, intermediate, and high cognitive demands among young and older groups, homozygous for the val or for the met allele. First, young val/val showed some disadvantages at brain and behavioral level compared to their m/m counterparts. However, in older adults subgroups, the m/m participants tended to show greater age-related difference (when compared to younger adults with similar genotype), suggesting an advantage in carrying the val allele when dopamine signaling is not at optimal efficiency (optimal: young/middle adulthood vs suboptimal: childhood or older ages). These results will be discussed in regard to compensating theories and dopaminergic models accounting for the potential effect of COMT polymorphism on stability/flexibility abilities. [less ▲]

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See detailLife cycle assessment of sound insulation solution made from waste paper
Groslambert, Sylvie ULg; Ernst, Valentin; Léonard, Angélique ULg

Poster (2016, May 09)

Buildings notably contribute to global environmental negative impacts due to con-sumption of both embodied energy and natural resources as well as various emissions during their whole life cycle. It is ... [more ▼]

Buildings notably contribute to global environmental negative impacts due to con-sumption of both embodied energy and natural resources as well as various emissions during their whole life cycle. It is therefore necessary to develop practices to reduce these impacts, mainly by reducing the part of non-renewable resource in material as well as by ensuring the lowest energy consumption possible during their lifetime. For instance, the use of recycled raw materials can lead to significant improvement in building environmental impact. In this context, the Life Cycle in Practice (LCiP) project helps SMEs to reduce the environmental impacts of their products and services across the entire life cycle. Within the frame of this project, Pan-Terre (BE) Acoustix panel impact is evaluated in a cradle-to-gate life cycle assessment (LCA). Evaluation of environmental performance is needed to support both the design and the production of waste based insulation solutions. Manufactured for the last twenty past years, the Acoustix Pan-Terre panel is designed for airborne sound insulation in walls and or floors. This product can only be obtained by mixing in a sensible way two raw materials from cellulose origin, recycled paper and broken shives of flax. Functional unit is 1 m² of panel ready for shipping. Acoustix panels are made by pressing a mix of cellulose from waste paper, flax shives and water. Scraps materials are entirely recycled in the process. Flax cultivation has a favourable impact on the climate change indicator due to carbon dioxide uptake for the photosynthesis occurring during the plant growth. But the drying of the panels is largely contributing to fossil fuel depletion and climate change due to natural gas burners. Life Cycle Assessment of Acoustix sound insulating panels ready to ship highlights some improvements that can be made by optimisation of the drying technology and the (partial) replacement of natural gas burners by alternative fuel burners (such as waste paper and scrap materials). Data are processed in SimaPro 8.1 software, with Ecoinvent 3 and ELCD 3 databases, and analyzed with the CML IA method. This method is compliant with the indicators required by EN15804 standard in order to communicate on the environmental performance of Acoustix panels. [less ▲]

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See detailFirst principles study of heavily doped full Heusler Fe2YZ for high thermoelectric power factor
Lemal, Sébastien ULg; Ghosez, Philippe ULg; Bilc, Daniel ULg

Poster (2016, May 02)

Using a combination of first-principles calculations based on density functional theory and Boltzmann semi-classical transport theory, we investigate the properties of heavily $n$-type doped full Heusler ... [more ▼]

Using a combination of first-principles calculations based on density functional theory and Boltzmann semi-classical transport theory, we investigate the properties of heavily $n$-type doped full Heusler Fe2YZ1-xAx compounds. Using a supercell approach and including explicitly the dopant impurities, we recover in some cases giant thermoelectric power factors as previously predicted under doping within the rigid band approximations [Phys. Rev. Lett. 114, 136601 (2015)]. In other cases, however, we highlight that the system evolves toward a ferromagnetic half-metallic ground state so that the power factor is strongly modified. We rationalize the appearance of this magnetic instability, showing that it consistent with the Stoner model. The uncovered properties of the heavily doped phases of the studied Fe2YZ1-xAx compounds appear promising for Seebeck and spin-Seebeck applications. [less ▲]

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See detailCrystallization behavior of neutralized and bleached shea butter under dynamic conditions
Gibon, V.; Dijckmans, P.; Blecker, Christophe ULg et al

Poster (2016, May 01)

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See detailBinary Phase Behavior of tripalmitoylglycerol and 1,3-dipalmitoyl-2-stearoyl-sn-glycerol
Bhaggan, K.; Smith, K. W.; Blecker, Christophe ULg et al

Poster (2016, May)

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See detailFrom Metabolomics to Identification of a new therapeutic approach for Age-Related Macular Degeneration (AMD)
Schoumacher, Matthieu ULg; De Tullio, Pascal ULg; LAMBERT, Vincent ULg et al

Poster (2016, May)

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

Age-related macular degeneration (AMD) is the leading cause of vision loss in the western world among people aged 50 or older. 90% of all vision loss due to AMD result from the exudative form, which is characterized by choroidal neovascularization (CNV). Age-related changes that induce pathologic CNV are incompletely understood and critical issues remain to be addressed. Metabolomics is defined as the comprehensive study of endogenous metabolites changes in various biological systems. This newly emerging “omic” science provides a unique opportunity to correlate variation of the metabolome with pathological occurrence or progression and/or to identify metabolites that are implicated in the disease. We apply a 1H NMR metabolomics approach on sera collected from AMD patient and healthy volunteers and form a mice model of laser-induced CNV which mimics the effect of exudative AMD. After post-processing treatments, the different spectra were analyzed by statistical discriminant methodologies (PCA, ICA, PLS-DA, O-PLS-DA). These approaches allow the differentiation between control and AMD patients and between laser-induced mice and the control mice group. Moreover, the same discriminating spectral zones have been identified in human and mice model, leading to the emergence of different putative biomarkers. Among these markers, lactate emerges as a key metabolite in both settings. Mechanistically, lactate produced locally and by inflammatory cells, plays a critical role in the onset of the inflammatory and angiogenic phases. In mice model of laser-induced CNV, normalization of circulating lactate by dichloroacetate a pyruvate dehydrogenase kinase (PDK) inhibitor, decreases CNV development. Our data support the innovative concept of lactate as a parainflammation- and angio-metabolite associated to AMD and CNV progression. Moreover, control of blood lactate level via inhibition of PDK provides new options for the treatment of exudative AMD. This study demonstrates the ability of metabolomics for drug target discovery and opens new perspectives for AMD treatment and patient follow-up. [less ▲]

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See detailStructuration of Robinia pseudoacacia L. genetic diversity in the American natural range and derived Belgian populations
Verdu, Cindy; Daïnou, Kasso; De Thier, Olivier et al

Poster (2016, May)

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See detailMicroplastics contamination in three planktivorous and commercial fish species
Collard, France ULg; Das, Krishna ULg; Gilbert, Bernard ULg et al

Poster (2016, May)

In 2014, 311 million tonnes of plastics were produced worldwide while it is estimated that 10% ended up in the oceans. Plastics adsorb many pollutants, cause entanglements in many vertebrates and provoke ... [more ▼]

In 2014, 311 million tonnes of plastics were produced worldwide while it is estimated that 10% ended up in the oceans. Plastics adsorb many pollutants, cause entanglements in many vertebrates and provoke blockage of the digestive tract of marine mammals, birds and turtles. Plastics also fragment in smaller parts, forming microplastics (<5 mm). These microplastics have the same size than planktonic organisms and can thus be ingested by filter-feeders and planktivorous organisms including fish. Although planktivorous Clupeiforme species are the most fished species in the world (17 million tonnes in 2013), the possible impact of microplastic ingestion on this group has received little attention. The aim of this study was to quantify and to characterize the ingested anthropogenic particles (AP) in herrings (Clupea harengus), sardines (Sardina pilchardus) and anchovies (Engraulis encrasicolus). Twenty individuals of each species were sampled. Herrings and sardines were caught in the Channel and in the North Sea in January 2013 and in January 2014. Anchovies were sampled in July 2013. The stomach contents were digested by sodium hypochlorite to isolate AP and then they were analysed by Raman spectroscopy and measured. AP were constituted of microplastics (MP) and cellulose fibres, sometimes associated with dyes. We found several plastic families: polyethylene (PE), polypropylene (PP), polystyrene, polyacrylonitrile, polyethylene terephthalate, polyamide and poly(butyl methacrylate). MP occurred in 35%, 50% and 40% of stomach contents of anchovies, sardines and herrings, respectively. Anchovies ingested bigger AP (2 mm) than the two other species. MP was in majority PE followed by PP. Our study shows that highly commercial species are exposed to MP. Further research is needed as MP are transport medium for organic pollutants and their fate once in the organism is unknown. [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, May)

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. References [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 detailNo evidence for genetic differentiation between French and Belgian populations of the exotic tree Robinia pseudoacacia
Bouteiller, Xavier; Aikio, E; Raimbault, A et al

Poster (2016, May)

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

Poster (2016, May)

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

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

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See detailDerivation of cochlear cells from pathological or isogenic human iPSCs for modeling hereditary hearing loss
Czajkowski, Amandine ULg; Grobarczyk, Benjamin; Hanon, Kevin ULg et al

Poster (2016, May)

Alström Syndrome (AS) is a human autosomal recessive genetic disorder characterized by numerous clinical symptoms including deafness. AS is caused by mutations in the ALMS1 gene encoding for ALMS1 protein ... [more ▼]

Alström Syndrome (AS) is a human autosomal recessive genetic disorder characterized by numerous clinical symptoms including deafness. AS is caused by mutations in the ALMS1 gene encoding for ALMS1 protein expressed at the basal body and implicated in ciliogenesis, cell cycle and proliferation (Jagger et al., 2011; Zulato et al., 2011 & Shenje et al., 2014). We are interesting in understanding the unknown mechanisms involving this protein in the genetic deafness of AS patients. To develop a model as closer as possible to the human pathology, we are using human induced pluripotent stem cells (hiPSCs) generated from fibroblasts of healthy and AS patients. Using a stepwise protocol, we demonstrated that healthy hiPSCs (waiting for isogenic hiPSCs) can generate a population of cells with gene and protein expression patterns consistent with the ones of otic progenitor cells (OSCs). At this differentiation stage, we observed some proliferation and apoptotic defects between healthy and AS cells. When human OSCs are co-cultured with mouse feeder cells, they are able to differentiate into hair cells (HCs). We successfully differentiated AS hiPSCs generated from AS patients into HCs. We are currently confirming gene expression pattern and testing HCs functionality.  To exclude patient linked epigenetics and differentiation defects, we are correcting the genomic mutation in the AS hiPSCs to generate isogenic hiPSCs using the CRIPSR/Cas9 system. Thanks to the isogenic hiPSCs we will be able to confirm that these defects are well due to the ALMS1 mutation. [less ▲]

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See detailGenetic predisposition to breast cancer occurring in a male-to-female transsexual patient
Potorac, Iulia ULg; CORMAN, Vinciane ULg; Manto, Florence et al

Poster (2016, May)

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See detailThe CCAMBIO project to characterize the biodiversity and distribution of microorganisms in microbial mats of Antarctic lakes
Durieu, Benoit ULg; Lara, Yannick ULg; Obbels, Dagmar et al

Poster (2016, April 29)

The BelSPO project CCAMBIO aims to study the biogeographical distribution of microorganisms in lacustrine microbial mats using a combination of techniques including microscopical observations (light and ... [more ▼]

The BelSPO project CCAMBIO aims to study the biogeographical distribution of microorganisms in lacustrine microbial mats using a combination of techniques including microscopical observations (light and electronic microscopy), strain isolation, and molecular diversity assessment using Next Generation Sequencing. The samples were collected in different Antarctic and sub-Antarctic biogeographical regions. A detailed microscopic study of the Antarctic diatom diversity allowed to revise a number of taxa and discover new ones. A multivariate analysis of diatoms showed that these regions hosted different diatom flora. Endemic diatom taxa were also observed, and a multigene molecular phylogeny of Pinnularia borealis showed a high genetic diversity. Pilot studies were conducted for the microeukaryotes and cyanobacteria to select NGS protocols and bioinformatic pipelines. Preliminary multivariate analysis of over 100 samples revealed that distinct biogeographic zones could be recognized in both the prokaryote and eukaryote data, which is in agreement with the classical subdivision of the Antarctic Realm into Maritime Antarctica, Continental Antarctica and the Sub-Antarctic Islands generally observed in plants and animals. Moreover, Sub-Antarctic assemblages harboured more complex foodwebs, with quite diverse metazoan groups. Lakes on the continent, however, were characterised by fewer metazoan groups and a greater importance of microbial herbivores and secondary consumers, including a relative high diversity of ciliates and tardigrades. Variation partitioning analysis revealed that spatial variables that approximated large-scale regional contrasts in historical (e.g. deglaciation history, geological origin) and climatic factors (e.g. mean annual air temperature) significantly explained the largest portion of the observed variation in community structure for eukaryotes, while in the prokaryote data environmental gradients related to conductivity were more important. In a first analysis of microbial mats from five Antarctic lakes and an aquatic biofilm from the Sub-Antarctic, the majority of the cyanobacterial OTUs retrieved were related to filamentous taxa such as Leptolyngbya and Phormidium, which are common genera in Antarctic lacustrine microbial mats. However, other phylotypes related to different taxa such as Geitlerinema, Pseudanabaena, Synechococcus, Chamaesiphon, Calothrix and Coleodesmium were also found. Results revealed a higher diversity than what had been reported using traditional methods based on microscopic observations and cultivation and also highlighted remarkable differences between the cyanobacterial communities of the studied lakes. In the next months, the molecular diversity data will be deposited into the “Microbial Antarctic Resource System (MARS)” presently developed into the webportal ‘biodiversity.aq’. The better knowledge of the diversity and distribution of microorganisms will contribute to a better assessment of their resilience and local/regional responses to global change. [less ▲]

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See detailUse of stable isotope ratios to delineate coastal benthic food web structure in Adélie Land (East Antarctica)
Michel, Loïc ULg; Dubois, Philippe; Eleaume, Marc et al

Poster (2016, April 29)

Antarctica currently undergoes strong and contrasted impacts linked with climate change. While the West Antarctic Peninsula is one of the most rapidly warming regions in the world, resulting in sea ice ... [more ▼]

Antarctica currently undergoes strong and contrasted impacts linked with climate change. While the West Antarctic Peninsula is one of the most rapidly warming regions in the world, resulting in sea ice cover decrease, in some parts of East Antarctica sea ice cover tends to increase, possibly in relation with changes in atmospheric circulation. Changes in sea ice cover are likely to influence benthic food web structure through modifications of benthic-pelagic coupling, disruption of benthic production and/or modifications of benthic community structure (i.e. resource availability for benthic consumers). Here, we studied shallow (0-20 m) benthic food web structure on the coasts of Petrels Island (Adélie Land, East Antarctica) during an event of unusually high spatial and temporal (two successive austral summers without seasonal break-up) sea ice cover. Using stable isotope ratios of C, N and S, we examined importance of several organic matter sources (benthic macroalgae, benthic biofilm, sympagic algae, suspended particulate organic matter and penguin guano) for nutrition of over 20 taxa of benthic invertebrates (sponges, sea anemones, nemerteans, sessile and mobile polychaetes, gastropods, bivalves, sipunculids, pycnogonids, amphipods, sea stars, sea urchins and sea cucumbers) spanning most present functional guilds. Our results provide insights about how Antarctic benthic consumers, which have evolved in an extremely stable environment, might adapt their feeding habits in response to sudden changes in environmental conditions and trophic resource availability. [less ▲]

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See detailElucidating diversity of thin filamentous mat-forming Antarctic cyanobacteria
Lara, Yannick ULg; Durieu, Benoit ULg; Deblander, Victor ULg et al

Poster (2016, April 29)

Freshwater ecosystems range from glacial cryoecosystems, ice shelf meltwater ponds to perennially ice-covered lakes where conspicuous benthic microbial mat communities constitute most of the biomass. In ... [more ▼]

Freshwater ecosystems range from glacial cryoecosystems, ice shelf meltwater ponds to perennially ice-covered lakes where conspicuous benthic microbial mat communities constitute most of the biomass. In these mats, cyanobacteria form matrices that shelter other organisms, and carry out the primary production. Narrow filamentous cyanobacteria belonging to the genera Leptolyngbya and Phormidium are especially abundant in Antarctic microbial mats and are essential for the formation of matrix. However, the lack of morphological criteria and the small cell size of cyanobacteria belonging to these two genera make their identification problematic. Indeed, they are known as polyphyletic taxa according to botanical and bacteriological criteria. The characterization of strains is the first step for an assessment of the real diversity and for understanding their role in the environment. We designed a polyphasic approach that combines molecular analyses, environmental physiology experiments and microscopic observations. Briefly, we amplified and sequenced three loci (16S rRNA, ITS, and rpoC1) for 31 strains of Leptolyngbya and Phormidium. We performed whole genome sequencing for five strains. Cultures at different stage were observed by light and epifluorescence microscopy. Finally, selected strains were grown in nitrogen-limited. The Leptolyngbya and Phormidium strains were distributed into four lineages. Phylogenetic trees supported the distribution of P. priestleyi strains into at least two potentially new lineages, and L. antarctica strains were separated into one endemic and one cosmopolitan lineage. This was supported by the microscopic observations of 1-year old cultures. Genome analyses revealed the presence of sequences related to the production of secondary metabolites in strains from two of the studied lineages. Secondary metabolites are often known for their antimicrobial activities. Such properties would partly explain how cyanobacterial mats survive to predation and degradation by other bacteria. This work provides the first building block to the understanding of survival strategies developed by mat-forming cyanobacteria and how they succeeded as the most abundant phototrophs on the Antarctic continent. This work was realized in the frame of the BelSPo project CCAMBIO. [less ▲]

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See detailModelling of long-term deep renovation strategies for the Belgian building stock
Ruellan, Guirec ULg

Poster (2016, April 28)

To achieve the EU energy targets for 2050, the construction sector has to perform major transformations. In Belgium, the majority of building stock is particularly old and energy inefficient. The high ... [more ▼]

To achieve the EU energy targets for 2050, the construction sector has to perform major transformations. In Belgium, the majority of building stock is particularly old and energy inefficient. The high performance of new constructions represented in the nearly zero energy buildings target is not sufficient to ensure the efficiency of the overall building sector. Therefore, it is crucial to put in place a progressive renovation policy. Despite the different renovation strategies and projects that took place in the recent year in Belgium, the overall renovation rate remains almost stable for the last ten years. This study focuses on the renovation market in Belgium and analyzes the factors that influence the evolution of the renovation rate. The objective is the identification and development of effective strategies bypass that leads to increased renovation rates in Belgium. The research methodology is based on an iterative process, based on a systematic literature review of Flemish and Walloon projects, publications and policy. These first work package will allow to identify factors influencing the renovation rate and in other hand to build a model of the existing building stock. Impacts of the influencing factors on the building stock are simulated in the fourth work package in order to propose an action plan in the last part. Three mains outcomes are expected: A model of the existing building stock in Belgium and its retrofit potential, a simulation of the effects of different strategies used to increase the renovation rate in Belgium and a theoretical action plan on strategies to increase the rate of renovation in Belgium. These results are necessary to inform and support the decision making of policy makers, municipalities and operational planning authorities across Belgium. [less ▲]

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See detailIsolation and characterization of mutants deficient in four steps of the phylloquinone biosynthesis pathway in Chlamydomonas reinhardtii.
Emonds-Alt, Barbara ULg; Remacle, Claire ULg; Cardol, Pierre ULg

Poster (2016, April 26)

In photosystem I (PSI), phylloquinone participates to electron transfer as secondary electron acceptor (A1). The phylloquinone biosynthesis pathway, previously characterized by reverse genetic in ... [more ▼]

In photosystem I (PSI), phylloquinone participates to electron transfer as secondary electron acceptor (A1). The phylloquinone biosynthesis pathway, previously characterized by reverse genetic in Synechocystis sp. PCC 6803, involves 8 enzymatic steps from chorismate [1]. In the green alga Chlamydomonas reinhardtii, characterization of phylloquinone biosynthesis was still partial and only one mutant deficient for MEND was characterized [2]. In the present work, we found MENA-H homologs in C. reinhardtii genomic database. In particular, MENF, MEND, MENC, and MENH catalytic domains are present in a single ORF (named PHYLLO by similarity to gene organisation in Arabidopsis). We then took advantage of the fact that a double reduction of plastoquinone (PQ) in PQH2 occurs in anoxia into the A1 site in the mend mutant, interrupting photosynthetic electron transfer [3], to isolate new phylloquinone-deficient strains. UPLC-MS analysis confirmed the absence of phylloquinone in four news mutants impaired in MENA, MENB, MENC (PHYLLO) and MENE. Despite this loss, men mutants are still able to grow in low light but are high light-sensitive. In low light, the level of active PSII in men mutants is identical to that of the wild-type, but the level of active PSI is reduced by 30-40% as assayed by spectroscopic measurements. This decrease is more pronounced when cells are exposed to high light intensities during 4 hours. The level of active PSI is ~ 10% of wild-type cells and the electron photosynthetic transfer is reduced accordingly. Reorganization of the photosynthetic apparatus following lack of phylloquinone in men mutants is discussed. [less ▲]

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See detailIsolation and characterization of mutants deficient in four steps of the phylloquinone biosynthesis pathway in Chlamydomonas reinhardtii.
Emonds-Alt, Barbara ULg; Remacle, Claire ULg; Cardol, Pierre ULg

Poster (2016, April 26)

In photosystem I (PSI), phylloquinone participates to electron transfer as secondary electron acceptor (A1). The phylloquinone biosynthesis pathway, previously characterized by reverse genetic in ... [more ▼]

In photosystem I (PSI), phylloquinone participates to electron transfer as secondary electron acceptor (A1). The phylloquinone biosynthesis pathway, previously characterized by reverse genetic in Synechocystis sp. PCC 6803, involves 8 enzymatic steps from chorismate [1]. In the green alga Chlamydomonas reinhardtii, characterization of phylloquinone biosynthesis was still partial and only one mutant deficient for MEND was characterized [2]. In the present work, we found MENA-H homologs in C. reinhardtii genomic database. In particular, MENF, MEND, MENC, and MENH catalytic domains are present in a single ORF (named PHYLLO by similarity to gene organisation in Arabidopsis). We then took advantage of the fact that a double reduction of plastoquinone (PQ) in PQH2 occurs in anoxia into the A1 site in the mend mutant, interrupting photosynthetic electron transfer [3], to isolate new phylloquinone-deficient strains. UPLC-MS analysis confirmed the absence of phylloquinone in four news mutants impaired in MENA, MENB, MENC (PHYLLO) and MENE. Despite this loss, men mutants are still able to grow in low light but are high light-sensitive. In low light, the level of active PSII in men mutants is identical to that of the wild-type, but the level of active PSI is reduced by 30-40% as assayed by spectroscopic measurements. This decrease is more pronounced when cells are exposed to high light intensities during 4 hours. The level of active PSI is ~ 10% of wild-type cells and the electron photosynthetic transfer is reduced accordingly. Reorganization of the photosynthetic apparatus following lack of phylloquinone in men mutants is discussed. [less ▲]

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See detailSingle-Molecule Force spectroscopy on synthetic Foldamers
Devaux, Floriane ULg; Li, Xuesong; Huc, Ivan et al

Poster (2016, April 26)

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See detailValidity of algometry and video assessment to diagnose pain in sheep with knee synovitis
Niessen, J; Nisolle, JF; Hontoir, F et al

Poster (2016, April 23)

Reasons to perform study. To assess lameness in animals, semi-objective scales are used. Video is sometimes used to enable blinding of the clinician. In addition, the assessment of pain is particularly ... [more ▼]

Reasons to perform study. To assess lameness in animals, semi-objective scales are used. Video is sometimes used to enable blinding of the clinician. In addition, the assessment of pain is particularly difficult in animals since they cannot report their feelings. The interpretation of the reactions of the animals can be different between observers. A method to quantify pain is the measure of mechanical nociceptive thresholds (MNT), a method called algometry. Since synovitis is often linked to swelling of periarticular tissues and to synovial fluid effusion, palpation of the joint is also a useful test. The objectives of the current study were to assess in sheep whether (1) video assessment of lameness is in agreement with real observation; (2) algometry of the knee is correlated with lameness evaluation; (3) algometry is correlated with identification of swelling by palpation. Material and methods. The population of sheep enrolled in a controlled trial at the Ovine Research Center of UNamur was used for the current study. Results. There was a moderate inter-rater agreement (value of kappa was 0,41) between the experimenter who evaluated the ewes on site and the one who watched the videos. No significant correlation was identified between lameness scores and algometry. A negative correlation (algometry reactive threshold is lower when palpation score is higher) was identified between palpation scores and MNT (P<0.05). Discussion. Video assessment can be used in research to assess lameness. The experience of the observer must be taken into account. Algometry is not entirely valid since an adaptation or learning process seems to develop in sheep. [less ▲]

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See detailEffect of Ribes nigrum leaf extracts on endothelium-dependent vasorelaxation
Tabart, Jessica; Shini-Kerth, Valérie; PINCEMAIL, Joël ULg et al

Poster (2016, April 22)

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See detailUsing a dynamic vegetation model for future projections of crop yields : application to Belgium in the framework of the VOTES and MASC projects
Jacquemin, Ingrid ULg; Henrot, Alexandra-Jane ULg; Fontaine, Corentin M. et al

Poster (2016, April 22)

Dynamic vegetation models (DVM) were initially designed to describe the dynamics of natural ecosystems as a function of climate and soil, to study the role of the vegetation in the carbon cycle. These ... [more ▼]

Dynamic vegetation models (DVM) were initially designed to describe the dynamics of natural ecosystems as a function of climate and soil, to study the role of the vegetation in the carbon cycle. These models are now directly coupled with climate models in order to evaluate feedbacks between vegetation and climate. But DVM characteristics allow numerous other applications, leading to amelioration of some of their modules (e.g., evaluating sensitivity of the hydrological module to land surface changes) and developments (e.g., coupling with other models like agent-based models), to be used in ecosystem management and land use planning studies. It is in this dynamic context about DVMs that we have adapted the CARAIB (CARbon Assimilation In the Biosphere) model. One of the main improvements is the implementation of a crop module, allowing the assessment of climate change impacts on crop yields. We try to validate this module at different scales: - from the plot level, with the use of eddy-covariance data from agricultural sites in the FLUXNET network, such as Lonzée (Belgium) or other Western European sites (Grignon, Dijkgraaf,. . . ), - to the country level, for which we compare the crop yield calculated by CARAIB to the crop yield statistics for Belgium and for different agricultural regions of the country. Another challenge for the CARAIB DVM was to deal with the landscape dynamics, which is not directly possible due to the lack of consideration of anthropogenic factors in the system. In the framework of the VOTES and the MASC projects, CARAIB is coupled with an agent-based model (ABM), representing the societal component of the system. This coupled module allows the use of climate and socio-economic scenarios, particularly interesting for studies which aim at ensuring a sustainable approach. This module has particularly been exploited in the VOTES project, where the objective was to provide a social, biophysical and economic assessment of the ecosystem services in four municipalities under urban pressure in the center of Belgium. The biophysical valuation was carried out with the coupled module, allowing a quantitative evaluation of key ecosystem services as a function of three climatic and socio-economic scenarios. [less ▲]

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See detailHigh anthocyanins content of commercial blackcurrant juices induced endothelium-dependent relaxation in isolated porcine coronary arteries
Kevers, Claire ULg; Shini-Kerth, Valérie; Tabart, Jessica et al

Poster (2016, April 22)

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Peer Reviewed
See detailHeart failure assessment with a multiscale model
Negroni, Jorge; Cabrera-Fischer, Edmundo; Kosta, Sarah ULg et al

Poster (2016, April 21)

Many cardiac diseases lead to heart failure (HF) causing increasing morbidity and mortality worldwide. Several alterations at the myocyte level have been identified, but their specific influence on ... [more ▼]

Many cardiac diseases lead to heart failure (HF) causing increasing morbidity and mortality worldwide. Several alterations at the myocyte level have been identified, but their specific influence on contractile and hemodynamic impairment is not yet clear. Mathematical modeling is a tool to address this issue enabling the analysis of individual myocyte changes on the overall circulatory response. Some myocyte models have been able to reproduce the impact of HF on experimentally detected myocyte components (1), but their integration into a ventricular model forming part of a multiscale circulatory approach has not been fully undertaken. Thus, the aim of this study is to compare the experimental hemodynamic and regional contractile response to acute HF versus a multiscale model based on a human myocyte representation. The experimentally-validated multiscale model shows adequate coupling between myocyte-derived left ventricular chamber and circulatory properties , and would be useful to predict the contractile and hemodynamic response to HF changes in myocyte variables. [less ▲]

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See detailAssessment of a design to monitor the influence of crop residue management on the dynamics of soil water content with ERT
Chelin, Marie ULg; Hiel, Marie-Pierre ULg; Hermans, Thomas ULg et al

Poster (2016, April 21)

Choices related to crop residue management affect the soil structure. As a consequence, they may determinethe spatio-temporal dynamics of water content and eventually the crop yields. In order to better ... [more ▼]

Choices related to crop residue management affect the soil structure. As a consequence, they may determinethe spatio-temporal dynamics of water content and eventually the crop yields. In order to better understand the influence of these strategies on hydraulic processes occurring at the plot scale, we opted for the use electrical resistivity tomography (ERT). This approach presents the advantage to limit soil disturbance but is still faced to important challenges when applied in an agricultural field context. Especially changing soil-electrode contact has to be considered, as it can lead to bad quality data, especially for setups with small electrodes and small inter-electrode distance. The objective of this study was to test the efficiency of a high-resolution 3-D field measurement design to properly assess the dynamics of soil water content. ERT measurements were conducted in a Cutanic Siltic Luvisol in Gembloux, Belgium, on two plots of 2m^2 ploughed in Oct 2014 at a depth of 25 cm and sown with maize in April 2015. The plants were removed on one of the plots in order to obtain a bare soil reference. A grid of 98 surface stainless steel electrodes was layed-out on each plot and four sticks supporting each eight stainless steel electrodes were vertically inserted into the soil up to 1.20 m to get more detailed information in depth. The experiments were performed between Jul and Oct 2015, in order to get measurements both in dry and wet periods. For surface and borehole monitoring, a dipole-dipole array configuration including in-line and cross-line measurements was adopted. Normal and reciprocal measurements were performed systematically to assess the data quality: only the datasets with a mean reciprocal error lower than 3% were considered for the data inversion. This contribution will show the first inverted results showing the complexity of experimental design and data analysis for high-resolution, timelapse ERT in field conditions. Based on these results, we will draw conclusions about a minimal data set to be obtained in our upcoming field experiments. [less ▲]

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See detailTime lapse imaging of water content with geoelectrical methods: on the interest of working with absolute water content data
Dumont, Gaël ULg; Pilawski, Tamara ULg; Robert, Tanguy et al

Poster (2016, April 21)

The electrical resistivity tomography is a suitable method to estimate the water content of a waste material and detect changes in water content. Various ERT profiles, both static data and time-lapse ... [more ▼]

The electrical resistivity tomography is a suitable method to estimate the water content of a waste material and detect changes in water content. Various ERT profiles, both static data and time-lapse, where acquired on a landfill during the Minerve project. In the literature, the relative change of resistivity ( Delta rho/rho ) is generally computed. For saline or heat tracer tests in the saturated zone, the Delta rho/rho can be easily translated into pore water conductivity or underground temperature changes (provided that the initial salinity or temperature condition is homogeneous over the ERT panel extension). For water content changes in the vadose zone resulting of an infiltration event or injection experiment, many authors also work with the Delta rho/rho or relative changes of water content Delta theta /theta (linked to the change of resistivity through one single parameter: the Archie’s law exponent “m”). This parameter is not influenced by the underground temperature and pore fluid conductivity ( rho_w) condition but is influenced by the initial water content distribution. Therefore, you never know if the loss of / signal is representative of the limit of the infiltration front or more humid initial condition. Another approach for the understanding of the infiltration process is the assessment of the absolute change of water content ( Delta theta ). This requires the direct computation of the water content of the waste from the resistivity data. For that purpose, we used petrophysical laws calibrated with laboratory experiments and our knowledge of the in situ temperature and pore fluid conductivity parameters. Then, we investigated water content changes in the waste material after a rainfall event ( Delta theta = Delta theta /theta * theta ). This new observation is really representatives of the quantity of water infiltrated in the waste material. However, the uncertainty in the pore fluid conductivity value may influence the computed water changes ( Delta theta =k*m*(rho_w)^1/2 ; where “m” is the Archie’s law exponent). Using these two complementary approaches, we analyzed the effect a major rainfall (20-30 mm in 2 hours) that occurred on the test site, characterized by a vegetalized and relatively dry zone and a devegatelized and humid zone. We intended to prove that most of the information contained in the Delta theta /theta distribution is the initial water content distribution in the ground.Water addition in dry zones resulting in large relative changes. The computation of the Delta theta is necessary to demonstrate preferential infiltration through the capping in a restricted zone of the vegetalized area. [less ▲]

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Peer Reviewed
See detailSupporting integrated and systemic management of windthrow crises by public decision-makers
Riguelle, Simon ULg; Hebert, Jacques ULg; Lejeune, Philippe ULg et al

Poster (2016, April 21)

This poster presents the development of an integrated framework for systemic management of storm damage risk in Wallonia (Belgium) and how it can be implemented throughout the risk management cycle with ... [more ▼]

This poster presents the development of an integrated framework for systemic management of storm damage risk in Wallonia (Belgium) and how it can be implemented throughout the risk management cycle with user-friendly tools and suitable methodologies. [less ▲]

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See detailHigh-resolution climate and land surface interactions modeling over Belgium: current state and decennial scale projections
Jacquemin, Ingrid ULg; Henrot, Alexandra-Jane ULg; Beckers, Veronique et al

Poster (2016, April 21)

The interactions between land surface and climate are complex. Climate changes can affect ecosystem structure and functions, by altering photosynthesis and productivity or inducing thermal and hydric ... [more ▼]

The interactions between land surface and climate are complex. Climate changes can affect ecosystem structure and functions, by altering photosynthesis and productivity or inducing thermal and hydric stresses on plant species. These changes then impact socio-economic systems, through e.g., lower farming or forestry incomes. Ultimately, it can lead to permanent changes in land use structure, especially when associated with other non-climatic factors, such as urbanization pressure. These interactions and changes have feedbacks on the climate systems, in terms of changing: (1) surface properties (albedo, roughness, evapotranspiration, etc.) and (2) greenhouse gas emissions (mainly CO2, CH4, N2O). In the framework of the MASC project (« Modelling and Assessing Surface Change impacts on Belgian and Western European climate »), we aim at improving regional climate model projections at the decennial scale over Belgium and Western Europe by combining high-resolution models of climate, land surface dynamics and socio-economic processes. The land surface dynamics (LSD) module is composed of a dynamic vegetation model (CARAIB) calculating the productivity and growth of natural and managed vegetation, and an agent-based model (CRAFTY), determining the shifts in land use and land cover. This up-scaled LSD module is made consistent with the surface scheme of the regional climate model (RCM: ALARO) to allow simulations of the RCM with a fully dynamic land surface for the recent past and the period 2000-2030. In this contribution, we analyze the results of the first simulations performed with the CARAIB dynamic vegetation model over Belgium at a resolution of 1km. This analysis is performed at the species level, using a set of 17 species for natural vegetation (trees and grasses) and 10 crops, especially designed to represent the Belgian vegetation. The CARAIB model is forced with surface atmospheric variables derived from the monthly global CRU climatology or ALARO outputs (from a 4 km resolution simulation) for the recent past and the decennial projections. Evidently, these simulations lead to a first analysis of the impact of climate change on carbon stocks (e.g., biomass, soil carbon) and fluxes (e.g., gross and net primary productivities (GPP and NPP) and net ecosystem production (NEP)). The surface scheme is based on two land use/land cover databases, ECOPLAN for the Flemish region and, for the Walloon region, the COS-Wallonia database and the Belgian agricultural statistics for agricultural land. Land use and land cover are fixed through time (reference year: 2007) in these simulations, but a first attempt of coupling between CARAIB and CRAFTY will be made to establish dynamic land use change scenarios for the next decades. A simulation with variable land use would allow an analysis of land use change impacts not only on crop yields and the land carbon budget, but also on climate relevant parameters, such as surface albedo, roughness length and evapotranspiration towards a coupling with the RCM. [less ▲]

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See detailData-Interpolating Variational Analysis (DIVA) software: recent development and application
Watelet, Sylvain ULg; Back, Örjan; Barth, Alexander ULg et al

Poster (2016, April 20)

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See detailThe last millenia sedimentary record of Lago Esponja from Northern Chilean Patagonia
Fagel, Nathalie ULg; Alvarez, Denisse; Araneda, Alberto et al

Poster (2016, April 20)

We evaluate the climate and environmental variability of Northern Chilean Patagonia during the Last Millennia, using a multi-proxy analysis of a sediment core from Lago Esponja (45°09’S, 72°08’W). The ... [more ▼]

We evaluate the climate and environmental variability of Northern Chilean Patagonia during the Last Millennia, using a multi-proxy analysis of a sediment core from Lago Esponja (45°09’S, 72°08’W). The lake is located in the region of Aysen del General Carlos Ibanez del Campo, in NW Patagonia. The study focuses on a multiproxy analysis of sedimentary records. The longest core (150 cm long) was collected in 2014 at 40 m depth. The sediment, which is composed of light brown organic-rich clayey silt, was analyzed for sedimentology (grain size, magnetic susceptibility organic matter and biogenic silica content), mineralogy (X-ray diffraction) and geochemistry (elemental and isotopic analyses of C and N, XRF core-scaner at 1 mm resolution). The radiocarbon ages, measured on 3 macro-remains, demonstrate that the core covers the last 6.700 years. The sedimentation rate ranges between 0.1 mm/yr in the lower section (100-150 cm) and 0.4 mm/yr in the upper meter. Visual descriptions and Scopix radiographies show that the sediment record is finely laminated except a massive decimetric coarser and darker layer corresponding to a tephra (estimated age 700AD±50). Magnetic susceptibility (confirmed by scopix radiographies) highlights the presence of 8 additional millimetric tephra layers. The biogenic silica content of the sediment is low (mean 5%). Diatom assemblage is dominated by benthic and acidophilous species, with high saprobic values. None marked changes were observed regarding the dynamic of the lake. The high organic matter content (mean 15%) and its high C/N ratio (12.7) throughout the core indicate inputs of allochtonous and terrestrial organic matter. Such parameters present high sediment variability also marked by changes in the chemical composition. The laminations reflect changes in the allochtonous sedimentary inputs, with high terrestrial inputs during wetter conditions in relation with the Westerlies. The sedimentary records of Lago Esponja will be compared with Eastern lacustrine record from the same latitude in order to confirm the climate-driven record. [less ▲]

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See detailMines as lower reservoir of an UPSH (Underground Pumped Storage Hydroelectricity): groundwater impacts and feasibility
Bodeux, Sarah ULg; Pujades, Estanislao ULg; Orban, Philippe ULg et al

Poster (2016, April 20)

The energy framework is currently characterized by an expanding use of renewable sources. However, their inter- mittence could not afford a stable production according to the energy demand. Pumped Storage ... [more ▼]

The energy framework is currently characterized by an expanding use of renewable sources. However, their inter- mittence could not afford a stable production according to the energy demand. Pumped Storage Hydroelectricity (PSH) is an efficient possibility to store and release electricity according to the demand needs. Because of the topographic and environmental constraints of classical PSH, new potential suitable sites are rare in countries whose topography is weak or with a high population density. Nevertheless, an innovative alternative is to construct Underground Pumped Storage Hydroelectricity (UPSH) plants by using old underground mine works as lower reservoir. In that configuration, large amount of pumped or injected water in the underground cavities would impact the groundwater system. A representative UPSH facility is used to numerically determine the interactions with surrounding aquifers Different scenarios with varying parameters (hydrogeological and lower reservoir char- acteristics, boundaries conditions and pumping/injection time-sequence) are computed. Analysis of the computed piezometric heads around the reservoir allows assessing the magnitude of aquifer response and the required time to achieve a mean pseudo-steady state under cyclic solicitations. The efficiency of the plant is also evaluated taking the leakage into the cavity into account. Combining these two outcomes, some criterions are identified to assess the feasibility of this type of projects within potential old mine sites from a hydrogeological point of view. [less ▲]

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See detailImpact of tillage on CO2 and N2O efflux in an agricultural crop
Lognoul, Margaux ULg; Theodorakopoulos, Nicolas ULg; Hiel, Marie-Pierre ULg et al

Poster (2016, April 20)

CO2 and N2O fluxes exchanged by a maize crop were measured from June to Octboer 2015 using a homemade automated system of dynamic closed chambers. We studied the impact of tillage (reduced and ... [more ▼]

CO2 and N2O fluxes exchanged by a maize crop were measured from June to Octboer 2015 using a homemade automated system of dynamic closed chambers. We studied the impact of tillage (reduced and conventional) on greenhouse gas emissions and nitrous oxide flux dynamics. [less ▲]

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Peer Reviewed
See detailHeat tracer test in an alluvial aquifer: field experiment and inverse modelling
Klepikova, Maria; Wildemeersch, Samuel; Jamin, Pierre ULg et al

Poster (2016, April 20)

Using heat as an active tracer for aquifer characterization is a topic of increasing interest. In this study, we investigate the potential of using heat tracer tests for characterization of a shallow ... [more ▼]

Using heat as an active tracer for aquifer characterization is a topic of increasing interest. In this study, we investigate the potential of using heat tracer tests for characterization of a shallow alluvial aquifer. A thermal tracer test was conducted in the alluvial aquifer of the Meuse River, Belgium. The tracing experiment consisted in simultaneously injecting heated water and a dye tracer in a piezometer and monitoring the evolution of groundwater temperature and tracer concentration in the recovery well and in monitoring wells. To get insights in the 3D characteristics of the heat transport mechanisms, temperature data from a large number of observation wells distributed throughout the field site (space-filling arrangement) were used. Temperature breakthrough curves in observation wells are contrasted with what would be expected in an ideal layered aquifer. They reveal strongly unequal lateral and vertical components of the transport mechanisms. The observed complex behavior of the heat plume was explained by the groundwater flow gradient on the site and heterogeneity of hydraulic conductivity field. Moreover, due to high injection temperatures during the field experiment a temperature-induced fluid density effect on heat transport occurred. By using a flow and heat transport numerical model with variable density coupled with the pilot point inverse approach, main preferential flow paths were delineated. [less ▲]

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See detailDrought-related vulnerability and risk assessment of groundwater in Belgium: estimation of the groundwater recharge and crop yield vulnerability with the B-CGMS
Jacquemin, Ingrid ULg; Verbeiren, Boud; Vanderhaegen, Sven et al

Poster (2016, April 19)

Due to common belief that regions under temperate climate are not affected by (meteorological and groundwater) drought, these events and their impacts remain poorly studied: in the GroWaDRISK, we propose ... [more ▼]

Due to common belief that regions under temperate climate are not affected by (meteorological and groundwater) drought, these events and their impacts remain poorly studied: in the GroWaDRISK, we propose to take stock of this question. We aim at providing a better understanding of the influencing factors (land use and land cover changes, water demand and climate) and the drought-related impacts on the environment, water supply and agriculture. The study area is located in the North-East of Belgium, corresponding approximatively to the Dijle and Demer catchments. To establish an overview of the groundwater situation, we assess the system input: the recharge. To achieve this goal, two models, B-CGMS and WetSpass are used to evaluate the recharge, respectively, over agricultural land and over the remaining areas, as a function of climate and for various land uses and land covers. B-CGMS, which is an adapted version for Belgium of the European Crop Growth Monitoring System, is used for assessing water recharge at a daily timestep and under different agricultural lands: arable land (winter wheat, maize...), orchards, horticulture and floriculture and for grassland. B-CGMS is designed to foresee crop yield and obviously it studies the impact of drought on crop yield and raises issues for the potential need of irrigation. For both yields and water requirements, the model proposes a potential mode, driven by temperature and solar radiation, and a water-limited mode for which water availability can limit crop growth. By this way, we can identify where and when water consumption and yield are not optimal, in addition to the Crop Water Stress Index. This index is calculated for a given crop, as the number of days affected by water stress during the growth sensitive period. Both recharge and crop yield are assessed for the current situation (1980 – 2012), taking into account the changing land use/land cover, in terms of areas and localization of the agricultural land and where the proportion of the different crops had considerably evolved through time (e.g., increase of grain maize and potatoes while winter cereals decrease). The preliminary results of the recharge lead to an average value in the area showing a significant negative trend, in both simulations with fixed (base = 1980) and changing land cover. In the same time, we could observe an increasing number of water stress periods, especially for maize, one of the main crops in the area. Finally, a preliminary test will be presented for the horizon 2040, for which we use meteorological time series (for high and low hydrologic impacts) given by the CCI-HYDR Perturbation Tool (Ntegeka V. and Willems P., 2009). This preliminary test aims to (1) evaluate the amplitude of the potential recharge deficit and, (2) especially, to define vulnerability zones, affected by frequent water stress, in connection with irrigation needs which could possibly increase the groundwater extraction. [less ▲]

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See detailIs Ambrosia artemisiifolia L. able to expand its invaded range northward in Western Europe?
Ortmans, William ULg; Mahy, Grégory ULg; Monty, Arnaud ULg

Poster (2016, April 19)

Ambrosia artemisiifolia L. (common ragweed, Asteraceae) is an invasive weed causing a health crisis in Europe, due to its highly allergenic pollen. In Western Europe the invaded range covers most of ... [more ▼]

Ambrosia artemisiifolia L. (common ragweed, Asteraceae) is an invasive weed causing a health crisis in Europe, due to its highly allergenic pollen. In Western Europe the invaded range covers most of central and southern France, and northern Italy. Northwards beyond the edge of this range, occurrence of casual population have been described for years, but these populations do not appear to become invasive, and the species does not seem to spread. This situation raises the following question: Has the invaded range reached a limit or will the species continue its invasion northwards? To answer this question, we followed two complementary approaches. First we set up an experimental garden in Belgium, 250 km north to the current invaded range, to see if the local climate allows the completion of the species reproduction cycle. Second, we performed an in situ measurement campaign in 12 population located beyond the edge, within the range but near the margin, and in the center of the invaded range. The aim of this campaign was to test whether the species had reduced plant performance towards range margins. The results showed that the species is able to establish populations with high growth rates in Belgium. Furthermore, the species expressed similar performance across the considered areas, even beyond the current invasion front. No evidence of processes constraining the invasion was found, which suggests a great potential for invasion north to the current invaded range. In this uncertain situation, awareness actions should be considered in the northern countries. [less ▲]

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See detailReactive gases in the chemistry climate model ECHAM6-HAMMOZ
Schultz, Martin; Franco, Bruno ULg; Kaffashzadeh, Najmeh et al

Poster (2016, April 18)

The recently developed global chemistry climate model ECHAM6-HAMMOZ contains comprehensive and detailed schemes for tropospheric aerosol (HAM) and reactive gases chemistry (MOZ). The Jülich Atmospheric ... [more ▼]

The recently developed global chemistry climate model ECHAM6-HAMMOZ contains comprehensive and detailed schemes for tropospheric aerosol (HAM) and reactive gases chemistry (MOZ). The Jülich Atmospheric (chemical) Mechanism (JAM002) consists of more than 300 species and 650 reactions, including relatively detailed degradation pathways for various volatile organic compounds in the troposphere and stratosphere. State-of-the-art parameterisations for chemical and physical processes are included. Here we present evaluation results from a multi-year simulation of the present-day atmospheric composition. [less ▲]

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See detailCanopy proximity estimation and impact on long term turbulent fluxes above a heterogeneous forest
Hurdebise, Quentin ULg; Vincke, Caroline; De Ligne, Anne ULg et al

Poster (2016, April 18)

With the development of eddy covariance networks like Fluxnet, ICOS or NEON, long-term data series of carbon dioxide, water vapor and other gas exchanges between terrestrial ecosystems and atmosphere will ... [more ▼]

With the development of eddy covariance networks like Fluxnet, ICOS or NEON, long-term data series of carbon dioxide, water vapor and other gas exchanges between terrestrial ecosystems and atmosphere will become more and more numerous. However, long-term analyses of such exchanges require a good understanding of measurement conditions during the investigated period. Independently of climate drivers, measurements may indeed be influenced by measurement conditions themselves subjected to long-term variability due to vegetation growth or set-up changes. The present research refers to the Vielsalm Terrestrial Observatory (VTO) where fluxes of momentum, carbon dioxide, latent and sensible heat have been continuously measured by eddy covariance during twenty years. VTO is an ICOS site installed in a mixed forest (beech, silver fir, Douglas fir, Norway spruce) in the Belgian Ardennes. A multidisciplinary approach was developed in order to investigate the spatial and temporal evolution of several site characteristics: - displacement height (d) and relative measurement height (z-d) were determined using a spectral approach that compared observed and theoretical cospectra; - turbulence statistics were analyzed in the context of Monin-Obukhov similarity theory; - tree height during the measurement period was obtained by combining tree height inventories, a LIDAR survey and tree growth models; - measurement footprint was determined by using a footprint model. A good agreement was found between the three first approaches. Results show notably that z-d was subjected to both temporal and spatial evolution. Temporal evolution resulted from continuous tree growth as well as from a tower raise, achieved in 2009. Spatial evolution, due to canopy heterogeneity, was also observed. The impacts of these changes on measurements are investigated. In particular, it was shown that they affect measurement footprint, flux spectral corrections and flux quality. All these effects must be taken into consideration in order to disentangle long-term flux evolutions due to climate or phenology from changes resulting from measurement set-up changes. [less ▲]

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See detailSelection of wavelengths for the quantification of nitrogen concentration in winter wheat by multispectral vision
Marlier, Guillaume ULg; Leemans, Vincent ULg; Destain, Marie-France ULg et al

Poster (2016, April 18)

Hand-held sensors (SPAD meter, N-Tester, …) are used for detecting the leaves nitrogen concentration (Nc) on basis of an optical detection of the chlorophyll concentration. These devices are active ... [more ▼]

Hand-held sensors (SPAD meter, N-Tester, …) are used for detecting the leaves nitrogen concentration (Nc) on basis of an optical detection of the chlorophyll concentration. These devices are active sensors: an internal radiation source emits light and transmission through a leaf is measured in the red (650 nm) and in the near-infrared (920 nm) spectral regions. These devices present several drawbacks. The nitrogen concentration is gained by an indirect way through the chlorophyll concentration and the leaves have to be fixed in a defined position for the measurements. These drawbacks could be overcome by an imaging device that measures the canopy reflectance. Hence, the objective of the paper is to analyse the potential of multispectral imaging for detecting nitrogen concentration. The tests were carried out on parcels submitted to nitrogen inputs varying from 0 to 180 kg N.ha-1. Reference Nc measurements were obtained by the Kjeldahl method and a Hydro N-Tester (Yara). The developed imaging system comprised a CMos camera and a set of 22 interference filters ranging from 450 to 950 nm mounted on a wheel steered by a stepper motor. The image acquisition and the motor rotation were controlled by a program written in C++. The crop was imaged vertically at one meter height. The raw images presented 1280*1024 pixels covering an area approximately 0.5*0.4 m and were recorded with a 12 bits luminance resolution. To deal with the natural irradiance variability of the scene, a white reference was used and the integration time was automatically adjusted for each image. The image treatment included the segmentation of Photosynthetically Active Leaves (PAL) by using Bayes theorem and the computation of the mean PAL reflectance after correction of background and illumination fluctuations. Nc was estimated on basis of the 22 filters by Partial Least Square (PLS) method and by four filters selected by Best Subset Selection (BSS). In comparison with the Kjeldahl method, the estimation of Nc by the Hydro N-Tester, the PLS and the BSS (filters 600-80, 950-100, 650-40 and 450-80 nm) gave determination coefficient and standard error respectively equal to of 0.53, 0.29 %; 0.67, 0.21%; 0.56 and 0.25%. This indicated that the full multi-spectral approach gave significantly better Nc estimation than a portable device and suggested that a camera equipped with four filters would give similar results. [less ▲]

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See detailChemical and mineralogical proxies of erosion episodes in the dried lake sediments (Amik Lake, Southern Turkey): paleoenvironmental implications
El Ouahabi, Meriam ULg; Hubert, Aurelia ULg; Lebeau, Héléne et al

Poster (2016, April 17)

The Amik Basin in the Eastern Mediterranean region has been continuously occupied since 6000-7000 BC. The landscape has sustained with highly variable anthropic pressure culminating during the Late Roman ... [more ▼]

The Amik Basin in the Eastern Mediterranean region has been continuously occupied since 6000-7000 BC. The landscape has sustained with highly variable anthropic pressure culminating during the Late Roman Period when the Antioch city reached its golden age. The basin also sustained a high seismic activity (M≥7) as it is a releasing step-over along the Dead Sea Fault. The study focuses on the sedimentary record of the Amik Lake occupying 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. High resolution of mineralogical (XRD) and geochemical (XRF) analyses were performed. Quantitative mineralogical phases of sediments by the Rietveld method were computed using Topaz software. The age of the record is constrained combining radionuclide and radiocarbon dating, and checked using the correlation between the earthquake history and rapidly deposited layer identified. A high sedimentation rate of 0.12 cm/yr was inferred at the coring site. The 4000 years old record shows that significant fluctuations of the lake level and the riverine system inflow into the Amik Lake occurred. The Late Bronze lowstand leaded to punctual dryings of the lake at the end of the Bronze/Iron transition marked by the collapse of the Hittite Empire and during the Dark ages. At that time, the riverine was carrying a large terrigenous input linked to strong soil erosion related to deforestation, exploitation of mineral resources and the beginning of upland cultivation. During the Roman Period and in the later periods, upland soils were partly depleted and the riverine system completely transformed by channelization that leaded to a mashification of the Amik Basin. Chemical and mineralogical composition of sediments is quite diversified reflecting the significant geological variation of drainage basins. Abundant calcareous minerals, especially calcite, aragonite, dolomite and small amount of wollastonite characterize the different sedimentary levels recorded in the lake. Levels relatively rich in fluorite, richerite, enstatite, and wollastonite are a result of the erosion of the ophiolitic rocks from the surrounding Amanos Mountains. These levels are interpreted as corresponding to relatively high erosive periods, while more humid periods lead to more intensive weathering and consequently to the dominance of kaolinite, muscovite/illite and talc more advanced in the relative stability scale, indicating a climate with contrasting seasons. During the most recent Period a marked increase in terrigeneous minerals associated with a rise in dolomite indicates ungoing erosion as well as the drying-out of the lake. [less ▲]

Detailed reference viewed: 55 (7 ULg)