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See detailPerception of climate change and adaptation strategies in the drylands of West Africa : A review
De Longueville, Florence ULg; Ozer, Pierre ULg; Vigil, Sara ULg

Poster (2014, May 15)

The perception of climate change has become an exiting new field of research explored in recent years. This is a response from the international scientific community to the conclusions of the 4th report ... [more ▼]

The perception of climate change has become an exiting new field of research explored in recent years. This is a response from the international scientific community to the conclusions of the 4th report of the Intergovernmental Panel on Climate Change which had underlined serious deficiencies in this field, particularly in West Africa where population is largely dependent of rain-fed agriculture. Yet, a global survey of the literature since 2000 shows that most references on this topic were published over the last five years. [...] [less ▲]

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See detailDevelopment of an analytical method to detect simultaneously bisphenols using a multiplexed surface-enhanced Raman scattering quantitative approach
De Bleye, Charlotte ULg; Dumont, Elodie ULg; Sacre, Pierre-Yves ULg et al

Poster (2014, May 15)

Over the last decade, bisphenol A (BPA) attracted a lot of attention. This molecule, commonly used as a precursor to produce epoxy-resin and plastics, is an endocrine disruptor presenting an estrogenic ... [more ▼]

Over the last decade, bisphenol A (BPA) attracted a lot of attention. This molecule, commonly used as a precursor to produce epoxy-resin and plastics, is an endocrine disruptor presenting an estrogenic activity [1]. Despite its health toxicity, BPA is present in a broad variety of consumer goods released from plastic bottles and packaging for example. Since the discovery of its adverse health effect of BPA, the manufacturers tend to use structural analogues of BPA such as BPS, BPF and BPB to produce plastic materials [2]. However, the health safety of these molecules is still not demonstrated. Currently, bisphenols are actively researched and quantified using solid phase extraction and chromatography techniques which are time and solvents consuming. Therefore, it could be very interesting to quantify simultaneously bisphenols using a fast and “green” technique. Surface-enhanced Raman scattering (SERS) exalts dramatically the Raman scattering of molecules adsorbed or very closed to metallic surface enabling to detect very low amounts of analytes while keeping the structural information obtained from the spectrum which is very interesting to consider multiplexed analyses [3-4]. Moreover, SERS, which is a solvent free and fast acquisition technique, is an attractive tool in “Green Chemistry” [5]. In this context, the development of a multiplexed quantitative approach to detect bisphenol was considered. Silver nanoparticles (AgNps) were selected as SERS substrate and their functionalization was investigated taking into account the weak affinity of phenolic molecules for gold and silver surface [6]. Pyridine was selected as surface modifier and allowed to attract bisphenols around metallic surface thanks to hydrophobic interaction and hydrogen bonds [7]. Afterwards, the SERS samples preparation was optimized playing on the concentrations of pyridine and aggregating agent used to get the nanoparticles closer to each other which promotes the SERS effect. Tap water samples were spiked with different concentration of BPA from 5 ppb to 1000 ppb and analyzed using the optimized SERS sample preparation. A good linearity of the response was observed and a calibration curve with coefficient of determination (R2) of 0.9922 was obtained by plotting the intensity of a principal band of BPA versus the concentration. This last step was repeated using BPB as analyte and a calibration curve with a R2 of 0.9991 was obtained for the same range of concentration using a specific band intensity of BPB. Finally, tap water samples were spiked with different concentrations of BPA and BPB simultaneously and analyzed using SERS and it was possible to detect selectively the two molecules thanks to specific bands and a good linearity of the response was observed for both. To conclude, promising results were obtained which pave the way to “green” multiplexed quantitative analyses of very low concentrated analytes using SERS. References: [1] J.-H. Kang et al., Toxicology 226 (2006) 79-89 [2] C. Liao et al., J. Agric. Food Chem. 61 (2013) 4655-4662 [3] K. Kneipp et al., Chem. Rev. 99 (1999) 2957-2975. [4] R.F. Aroca et al., Adv.Colloid Interface Sci. 116 (2005) 45-61. [5] C. De Bleye et al., Talanta 116 (2013) 899-905. [6] X.X. Han et al., Anal. Chem., 83 (2011) 8582-8588. [7] B. San Vicente et al., Anal. Bioanal. Chem. 380 (2004) 115-122. [less ▲]

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See detailTest of humic substances on in vitro roots initiation using isolated leaves of woody species
Tahiri, Abdelghani ULg; Destain, Jacqueline ULg; Thonart, Philippe ULg et al

Poster (2014, May 15)

Arise from the chemical and biological degradation of plant and animal residues and from the synthetic activities of microorganisms in the soil, humic substances (HS) are natural heterogeneous aromatic ... [more ▼]

Arise from the chemical and biological degradation of plant and animal residues and from the synthetic activities of microorganisms in the soil, humic substances (HS) are natural heterogeneous aromatic and organic compounds. These substances are chemically complex with no clearly defined chemical structure, although generalized models have been proposed and they can be divided into fractions of humic acids, fulvic acids and humins depending on their solubility in water as a function of the pH. The stimulation of plant growth and development by HS are the activities that have attracted the attention of many scientists. They influence plant productivity directly by the stimulation of biochemical and metabolic processes or indirectly through the modification of soil characteristics and microflora activities. All together, these properties mainly affect root architecture. By inducing root hairs proliferation, differentiating root cells and enhancing lateral root emergence, an increase of the total root biomass is observed. Experiments targeting the rooting stages in absence of interferences were conducted in vitro using HS extracted from landfill leachate and a stable commercial formulation (“Humifirst” from TRADECORP company: 12% humic acid and fulvic acid 3%) issued from leonardite. Shoots and leaves explants of silver birch (Betula pendula Roth) and black alder (Alnus glutinosa L. Gaertn) vitro-plants were treated with 10 ppm leachate HS and 100 ppm Humifirst HS for 5 days during the rooting induction/initiation phase. The treated explants were then transferred into elongation medium containing only nitrate calcium for 4 weeks. The results show that application of HS during the root induction/initiation phase did not significantly influence root growth of both species in comparison with control explants. [less ▲]

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See detailIdentifying root-secreted proteases in Arabidopsis thaliana: an Activity-Based Protein Profiling approach.
Lallemand, Jérôme ULg; Périlleux, Claire ULg; Tocquin, Pierre ULg

Poster (2014, May 15)

Proteases are involved in many physiological processes during the whole life of the plant, such as embryonic development, defense against pathogens, nutrition or mycorrhiza creation. However, the ... [more ▼]

Proteases are involved in many physiological processes during the whole life of the plant, such as embryonic development, defense against pathogens, nutrition or mycorrhiza creation. However, the functions of many of the 800 proteases of Arabidopsis thaliana still remain unknown. Besides discovering new functions, studying proteases can also result in improving plant biotechnology. Indeed, plants can be used as hosts for recombinant protein production. Some proteins of interest require to be secreted in order to fold properly, but production yields are limited due to their degradation by endogenous extracellular proteases. The aim of our study is to identify active root-secreted proteases of Arabidopsis thaliana. Their activity was first analyzed by in vitro incubation with a target protein (BSA) at different values of pH and in the presence of proteases inhibitors. This analysis identified serine proteases as the major protease class involved in BSA degradation. Then, an Activity-Based Protein Profiling approach led to the labeling of two active serine proteases in the root-secreted sample. Finally, a further step towards the identification by mass spectrometry, based on affinity purification, was developed. [less ▲]

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See detailHow to build a biological linker dedicated to the engineering of novel drug delivery systems
Crasson, Oscar ULg; Galleni, Moreno ULg; Parente, Raffaella et al

Poster (2014, May 15)

Nowadays, chemical linkages are widely used in industry to coat bioactive molecules on biocompatible supports. However, some issues inherent to the linkage procedure remain. For example, chemical ... [more ▼]

Nowadays, chemical linkages are widely used in industry to coat bioactive molecules on biocompatible supports. However, some issues inherent to the linkage procedure remain. For example, chemical reactions often damage the structure and therefore the activity of the immobilized molecules. In this work, we propose the use of a human chitin binding domain (ChBD) to immobilized bioactive molecules on a polysaccharide-based surface. ChBD belongs to the human chitinase called chitotriosidase and was shown to interact specifically with chitin and chitooligomers. Using molecular biology and protein engineering, we have developped of a new biological tool based on the hybrid protein technology. In this technology, we can create chimeric proteins that have the ability to bind polysaccharidic supports thanks to their binding domain that can be covalently linked with any bioactive molecule that can confer prophylactic or therapeutic activities. In this study, we have successfully shown that we can use the chitin binding domain (ChBD) from the human chitotriosidase as a biological linker dedicated to the engineering of novel drug delivery systems containing chitin or other analogous polysaccharides. [less ▲]

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See detailCadmium and mercury sediment pollution along the British coastline of the Channel: A first spatio-temporal integrated approach
Richir, Jonathan ULg; Pini, Jennifer; Watson, Gordon

Poster (2014, May 15)

Cadmium (Cd) and Mercury (Hg) are 2 widespread trace metals occurring in both terrestrial and marine environments. They play no physiological role and are often toxic even at low concentrations and were ... [more ▼]

Cadmium (Cd) and Mercury (Hg) are 2 widespread trace metals occurring in both terrestrial and marine environments. They play no physiological role and are often toxic even at low concentrations and were therefore identified as priority hazardous substances under the European Water Framework Directive and included in the European List I of Dangerous Substances. Marine sediments are considered as the ultimate sink of non-degradable metals, where they can accumulate in considerable quantities. The UK coastline has been polluted with metals for decades or even centuries and, although many studies have monitored sediment metal loads in specific locations, there has been no recent systematic monitoring approach along the whole of the south coast. In addition, few reliable data exist on decadal temporal trends for most sediment pollutants. Focusing on Cd and Hg, we have investigated their spatial and temporal distribution in sediment samples collected from 42 sites along the English coast of the Channel from 1990 to 2010. From a temporal point of view, data analyses showed that mean Cd levels in sediments significantly decreased by 59 % during that period of time, from 0.78 to 0.32 mg kgDW-1 of sediments. This reflects a decrease globally to below the 0.70 mg kgDW-1 Cd Threshold Effect Level (TEL). Adverse effects caused by Cd on the biota should, therefore, be rare. Spatially, Cd displayed an east-to-west increase of its levels, with several western sites with Cd still above the TEL. Regarding Hg, sediment levels did not significantly change from 1990 to 2010, remaining approximately twice as high as the corresponding 0.13 mg kgDW-1 Hg TEL. Hg also displayed an east-to-west increase of its levels, whilst 55 % of monitored sites had a mean sediment Hg concentration in average 3.5 times higher than the TEL. Despite regulations, non-degradable metals such as Cd and Hg that have accumulated in sediments over considerable periods of time may consequently still pose threats to aquatic organisms, highlighting the need for continued extensive spatially and temporally integrated monitoring approaches. [less ▲]

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See detailMaize cold tolerance : in search of relevant parameters for discriminating genotypes
Riva-Roveda, Laetitia ULg; Escale, Brigitte; Giauffret, Catherine et al

Poster (2014, May 15)

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See detailÉvaluation des effets de la formation et de la supervision de services d'aide aux familles qui accompagnent des personnes atteintes d¿une maladie de type Alzheimer
Marquet, Manon ULg; Missotten, Pierre ULg; Charlot, Valentine ULg et al

Poster (2014, May 15)

Introduction : Il est nécessaire de développer des interventions visant à aider les professionnels qui accompagnent des personnes âgées (atteintes ou non de démence). Les programmes existants sont ... [more ▼]

Introduction : Il est nécessaire de développer des interventions visant à aider les professionnels qui accompagnent des personnes âgées (atteintes ou non de démence). Les programmes existants sont néanmoins essentiellement destinés aux aidants en milieu institutionnel. Objectif : Évaluer, au niveau de différents paramètres (âgisme, connaissances sur la maladie d’Alzheimer, sentiment de compétence, satisfaction professionnelle, burnout, stratégies de coping), l’efficacité d’une intervention destinée à des aidants professionnels à domicile. Méthodologie : 17 aides familiales ont bénéficié d’une formation et de supervisions visant à améliorer leurs connaissances sur les démences et à les aider à mettre en place des stratégies de résolution de problèmes face aux difficultés rencontrées dans leur pratique, et ceci, afin de favoriser une vision moins stigmatisante de la maladie d’Alzheimer. Différents auto-questionnaires ont été complétés par les participantes avant et après l’intervention. Résultats : Les analyses statistiques indiquent que l’intervention permet de diminuer l’âgisme des aidantes, d’améliorer leurs connaissances sur la maladie d’Alzheimer, leur sentiment de compétence et leur satisfaction vis-à-vis de leurs tâches professionnelles. Conclusion : L’intervention est efficace puisqu’elle atteint ses objectifs initiaux. Ces résultats encouragent non seulement la formation des aidants professionnels à domicile mais aussi l’évaluation de l’efficacité des interventions proposées, à la fois auprès des aidants professionnels, informels et des personnes accompagnées. En effet, sur base de la littérature [Avorn & Langer, 1982 ; Coudin & Alexopoulos, 2010], nous faisons l’hypothèse que l’amélioration des connaissances et la diminution de l’âgisme réduisent le risque d’induire des comportements de dépendance chez les personnes accompagnées. Ce constat est important compte tenu du rôle des aides familiales, à savoir aider les personnes âgées (atteintes ou non de démence) qui présentent des difficultés dans la réalisation des activités (instrumentales) de la vie quotidienne afin qu’elles restent le plus longtemps possible à leur domicile. [less ▲]

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See detailDiscrimination of two geographically distinct populations of sea bass Dicentrarchus labrax, using stable isotopic signatures of mercury (δ202Hg, Δ199Hg)
Cransveld, Alice ULg; Amouroux, David; Koutrakis, Emmanuil et al

Poster (2014, May 15)

Despite the reduction of mercury (Hg) emissions in Europe in the last decades, Hg emissions are increasing worldwide and concentrations found in some marine predators remain high. This raises questions on ... [more ▼]

Despite the reduction of mercury (Hg) emissions in Europe in the last decades, Hg emissions are increasing worldwide and concentrations found in some marine predators remain high. This raises questions on mercury's biogeochemical cycle at both local and global scale. In the present work, we investigate the possibility to use mercury isotopic signature in fish as a tool to discriminate different polluted areas and potential pollution sources. Indeed, Hg can exhibit both mass-dependent (MDF) and mass-independent fractionation (MIF). While MDF may occur during biological cycling inter alia and could be used to understand bioaccumulation processes, MIF provides a unique fingerprint of specific chemical pathways, such as photochemical transformations. In this context, information provided by Hg isotopes would help to improve environmental management strategies. A preliminary set of four and ten juvenile common sea bass, Dicentrarchus labrax were collected from the North Sea and the Aegean Sea respectively. T-Hg was analysed by direct mercury analyser (DMA), speciation by gas chromatography inductively coupled plasma mass spectrometer (GC-ICP-MS) and Hg isotope analysis were performed using cold vapour generation with multicollector ICP-MS. Total Hg concentrations in all tissues were higher in individuals from the North Sea ( Hgtot muscle=1,14 ± 0,48 mg.kg-1 dw) than from Greece (0,60 ± 0,06 mg.kg-1 dw). Speciation analysis shows that MeHg is the predominant form of Hg in muscle (89% MeHg on average) but not in liver (51% MeHg on average). Isotopic mass dependent values (δ202Hg) values were always higher in muscle than in liver and related to Hg species distribution. For mass independent isotopic signature, sea bass from the Aegean Sea had a systematically higher Δ199Hg value than individuals from the North sea (e.g.: 0,56 ± 0,05‰ and 0,32 ± 0,06‰ respectively in muscle). While mass dependent isotopic signature probably reflects some internal Hg metabolism, mass independent isotopic signature seems definitely site dependent. Such isotopic discrimination might be in agreement with difference in both mercury sources and cycling in the North and Aegean Seas. These preliminary results indicate that Hg isotopes may thus help to discriminate fish from different areas. This promising outcome must be further confirmed by extending the number of individuals and locations to be investigated. [less ▲]

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See detailThe effects of flowering signals on root architecture in Arabidopsis
Mathieu, Laura ULg; Lobet, Guillaume ULg; Périlleux, Claire ULg

Poster (2014, May 15)

Roots are responsible for water and nutrient uptake and hence are critical to sustain the whole plant life cycle. This study aims at characterizing how root development is affected by flowering. We ... [more ▼]

Roots are responsible for water and nutrient uptake and hence are critical to sustain the whole plant life cycle. This study aims at characterizing how root development is affected by flowering. We therefore focused on the effects of systemic signals produced in the leaves at floral transition, namely the proteins FLOWERING LOCUS T (FT) and TWIN SISTER OF FT (TSF), on root growth and branching. These proteins act in the shoot apical meristem as potent promoters of flowering [1] but their effects in other parts of the plant are still unknown. [less ▲]

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See detailQualitative and quantitative analyses of a pharmaceutical formulation produced by hot melt extrusion using Raman spectroscopy
Netchacovitch, Lauranne ULg; De Bleye, Charlotte ULg; Sacre, Pierre-Yves ULg et al

Poster (2014, May 15)

In the pharmaceutical industry, Hot Melt Extrusion (HME) is a recent technique used to integrate poor water soluble drugs in pharmaceutical formulations. Indeed, more and more active pharmaceutical ... [more ▼]

In the pharmaceutical industry, Hot Melt Extrusion (HME) is a recent technique used to integrate poor water soluble drugs in pharmaceutical formulations. Indeed, more and more active pharmaceutical ingredients (API) belong to the Biopharmaceutical Classification System (BCS) II and IV. Their integration in pharmaceutical solid forms is a big deal. HME processes increase the bioavailability and the solubility of those API by encompassing them in a polymeric carrier and by forming solid dispersions [1]. Moreover, in 2004, the FDA’s guidance initiative promoted the usefulness of Process Analytical Technology (PAT) tools when developing a manufacturing process. Vibrational spectroscopy is an appropriate PAT tool to analyze extrudates [2 – 3]. In this case, Raman spectroscopy, which belongs to vibrational spectroscopy, was used to analyze itraconazole extrudates qualitatively and quantitatively. During HME, the main objective is to develop solid dispersions by converting a crystalline API in an amorphous one, in order to improve its solubility and bioavailability [4]. According to Raman spectra, it is possible to identify the polymorphic form of the components in the extrudates by integrating or rationing the Raman bands that are characteristic of the API or by calculating the width at half intensity of some bands [5]. After determining the polymorphic form of the API, a quantitative method was developed in order to measure the ratio between the API and the polymer. Finally, chemical imaging was performed on extrudates to identify the distribution of the homogeneity of the API inside the polymer [6]. In conclusion, Raman spectroscopy is an appropriate tool to follow an extrusion process. By qualitative and quantitative analyses it is possible to determine the composition, the polymorphic form, the homogeneity, and the concentration of pharmaceutical matrices according to Raman fingerprint. References: [1] S. Shah et. al., Int J Pharm 453 (2013) 233 – 252. [2] L. Saerens et. al., Anal Chem 85 (2013) 5420 – 5429. [3] T. De Beer et. al., J Pharm Biomed Anal 48 (2008) 772 – 779. [4] A. Sarode et. al., Eur J Pharm Sci 48 (2013) 371 – 384. [5] E. Widjaja et. al., Eur J Pharm Sci 42 (2011) 45 – 54. [6] J. M. Amigo, Anal Bioanal Chem 398 (2010) 93 – 109. [less ▲]

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See detailSite-specific sediment characteristics impact on metal bioavailability and bioaccumulation in the Polychaete Nereis virens
Pini, Jennifer; Richir, Jonathan ULg; Watson, Gordon

Poster (2014, May 15)

The king ragworm (Nereis virens) is a cosmopolitan species of soft sediment inter-tidal communities and is known to be impacted by various pollutants. More precisely, in many coastal locations, N. virens ... [more ▼]

The king ragworm (Nereis virens) is a cosmopolitan species of soft sediment inter-tidal communities and is known to be impacted by various pollutants. More precisely, in many coastal locations, N. virens is exposed to a range of metals including copper and zinc which are known to be highly toxic. However, the relationships between metal bioavailable concentrations in the sediment, the pore water and the tissues of N. virens have not yet been investigated in this is ecologically and commercially important species. Hence, to investigate these relationships, sediment, pore water and associated worms samples were collected from seven sites along the English Channel coast of the UK, chosen for their different pollution histories. The BCR three-step sequential extraction procedure was used to assess the bioavailable metal concentrations in the sediment, in conjunction to standard extraction techniques to determine the tissue and the pore water concentrations. All samples were measured by Atomic Absorption Spectroscopy (FAAS). Results from correlation analyses showed that site specificities and metal pollution histories along with sediment characteristics (organic content and particle size) were important factors regarding the bioavailability of copper and zinc to worms. Indeed, sediment organic content and grain size were positively correlated to metal bioavailable concentrations in the sediment. Strong correlations were found between copper bioavailability in the sediment and in the pore water and between zinc concentrations in the pore water and in N. virens. These results showed that zinc from the pore water was more readily bioavailable to N. virens than copper. However, our data suggested that N. virens accumulated metals regardless of the pollution history/level of the sites. In addition, our data showed that metal concentrations in N. virens were lower than those found in other closely related polychaetes such as N. diversicolor. This suggests that N. virens, unlike other polychaetes, is well adapted to highly contaminated sites by the possible use of specific metal regulation mechanisms, which would require further analysis. [less ▲]

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See detailImpact des stéréotypes liés au vieillissement et à la maladie d’Alzheimer sur le vécu des aidants familiaux
Bottard, Aude; Adam, Stéphane ULg; Gilles, Christian et al

Poster (2014, May 15)

INTRODUCTION Dans notre société, les personnes âgées atteintes de la maladie d’Alzheimer sont les cibles à la fois de stéréotypes liés à l’âge, mais aussi de stéréotypes liés à cette maladie (Sartorius ... [more ▼]

INTRODUCTION Dans notre société, les personnes âgées atteintes de la maladie d’Alzheimer sont les cibles à la fois de stéréotypes liés à l’âge, mais aussi de stéréotypes liés à cette maladie (Sartorius, 2003). Leur aidant familial est également souvent touché par l’image négative de la pathologie que les stéréotypes imputent à leur proche (Werner, 2008). Aussi, cette recherche a pour objectif de mieux connaître le point de vue d’aidants familiaux sur la maladie d’Alzheimer et le vieillissement, pour mieux appréhender les implications de ces représentations sur leur vécu. METHODE Un ensemble de questionnaires, dont des mesures de la vision du vieillissement (FSA-R ; Boudjemadi & Gana, 2009) et de la maladie d’Alzheimer (FS-ADS ; Werner et al., 2011), ont été administrés à 38 aidants familiaux dont le proche est atteint de la maladie d’Alzheimer ou d’une démence apparentée. RESULTATS Les analyses statistiques montrent que les individus qui présentent une vision négative du vieillissement sont ceux qui sont aidants depuis plus longtemps. Par ailleurs, les personnes qui ont un vécu négatif de la maladie (qui ont honte de leur proche ou qui sentent que les autres ont honte de lui), sont ceux qui se sentent moins compétents en tant qu’aidant. De même, le fait d’avoir peur de son proche, est associé à un épuisement physique et émotionnel, ainsi qu’à une humeur triste et anxieuse. CONCLUSION Les stéréotypes liés à l’âge et à la maladie péjorent plusieurs éléments du vécu de l’aidant (santé, sentiment de compétence, expérience en tant qu’aidant.). En conséquence, il importe d’encourager la déconstruction des stéréotypes et idées reçues véhiculés par la société, notamment par le biais de programmes d’aide aux aidants [less ▲]

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See detailBelgian Grasshoppers: A Nutritious Food Source
Paul, Aman ULg; Frederich, Michel ULg; Blecker, Christophe ULg et al

Poster (2014, May 14)

Rapid urbanization and rising economies are creating shifts in the composition of global food demand, so it is necessary to explore new sources of food with better nutritional profile. Among the ... [more ▼]

Rapid urbanization and rising economies are creating shifts in the composition of global food demand, so it is necessary to explore new sources of food with better nutritional profile. Among the alternative food that exists are the grasshoppers, about 80 species of which are consumed worldwide. Grasshoppers are not only rich source of proteins and lipids but also some important minor component like vitamins and minerals. Edible species of grasshopper in Belgium were identified and attempts were made for the lab rearing of meadow grasshopper (Chorthippus parallelus). The lipids as well as protein contents of meadow grasshopper (Chorthippus parallelus) & long winged conehead (Conocephalus discolor) were investigated. The fatty acid compositions of these two species were determined by gas chromatography. Some of the physicochemical properties of the lipids extracted were also analyzed. These two grasshopper species could be really nutritious source of food. [less ▲]

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See detailImproving soil conservation through an adapted tillage: experience from the cultivation of potatoes in Bamiléké's hills of Cameroon
Djoukeng, Henri Grisseur ULg; Tankou, Christopher Mubeteneh; Degré, Aurore ULg

Poster (2014, May 14)

The western highlands of Cameroon are an area where the population density and growth rates are the highest in the country. In this region, the main activity is agriculture, and rivers are the main source ... [more ▼]

The western highlands of Cameroon are an area where the population density and growth rates are the highest in the country. In this region, the main activity is agriculture, and rivers are the main source of safe drinking water. Lacks of arable land and especially against very complex land tenure, farmers are increasingly exploiting the hills (9-30 % slope) for the production of vegetable crops, mainly potatoes. The methods of preparation of soil found there are ridging in the direction of the slope and the culture dish. These practices promote erosion by runoff, generally compromises the multiple functions of agriculture, and in particular the environmental function (soil degradation, pollution and silting up of rivers) and the production function (incomes). In order to ensure soil stability and maintain good water quality of rivers, we put it up a new way of preparing the ground: the tied ridging. To quantify the effectiveness of the latter, we conducted tests of erosion by runoff with Wischmeier’s plots on the most exploited slopes, namely 11% and 29%. The run-off water and sediments were collected per plot and per block after every rain. The first analyses show that there is a significant difference between the culture dish or ridging along the slope and tied ridging. The major constraint of this practice lies in the increase of about 17% of the labor. Tied ridging reported losses in average land 16% lower compared with the ridging in the direction of the slope and 22% compared with the culture dish, he also presented higher yields of 65 % compared with the culture dish and the ridging in the direction of the slope. Despite the hardship, the test results have convinced the participants and some curious farmers which have adopted the technology during the next growing season. [less ▲]

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See detailAdaptation to beach erosion in the African coastal cities: from the procrastination by the Government to the forced migration of the most precarious population. The case of Cotonou, Benin
Ozer, Pierre ULg; De Longueville, Florence ULg; Hountondji, Yvon Carmen et al

Poster (2014, May 14)

This analysis shows that the current impacts of geomorphological changes result mainly from the sum of human activities. However, it is necessary to consider the risk of coastal erosion and forced ... [more ▼]

This analysis shows that the current impacts of geomorphological changes result mainly from the sum of human activities. However, it is necessary to consider the risk of coastal erosion and forced migration (of mostly poor people) in the coming decades with the amplification of sea level rise due to global warming. [less ▲]

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See detailMicroplastics contamination in two planktivorous and commercial fish species
Collard, France ULg; Parmentier, Eric ULg; Das, Krishna ULg

Poster (2014, May 13)

Plastic pollution is a huge environmental concern and affects each marine ecosystem. Plastics are produced by millions of tonnes each year in the world and finally accumulate in oceans. They adsorb many ... [more ▼]

Plastic pollution is a huge environmental concern and affects each marine ecosystem. Plastics are produced by millions of tonnes each year in the world and finally accumulate in oceans. They adsorb many persistent organic pollutants, cause external and internal wounds and provoke blockage of the digestive tract of marine mammals, birds and turtles. Plastics can also threaten marine organisms of small size class in the same way by fragmenting in smaller parts that result in microplastics of less than five millimetres. These microplastics are of the same order of magnitude than plankton and can thus be ingested by filter-feeders, suspension-filters and planktivorous organisms such as fish. Few studies deal with microplastics ingestion by fish and even less by commercial fish species. The herring (Clupea harengus) and the sardine (Sardina pilchardus) were respectively the third and the eighth most caught fish species in the world in 2009. We focused our research on these two species which are of economic importance. We sampled around thirty individuals of each species in the Channel and in the North Sea in January 2013. The stomach contents were digested by sodium hypochlorite and then analyzed. Microplastics were characterized by size, colour and shape. The results of these analyses will highlight the need for studies about microplastics ingestion by planktivorous species. [less ▲]

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See detailFully implicit integration scheme for the GTN model
Guzmán Inostroza, Carlos Felipe ULg; Habraken, Anne ULg

Poster (2014, May 12)

Fully integration scheme for the GTN model, applied to some shear extensions. The model also comprises Hill type anisotropy and mixed (Isotropic/kinematic) hardening. The consistent tangent matrix is also ... [more ▼]

Fully integration scheme for the GTN model, applied to some shear extensions. The model also comprises Hill type anisotropy and mixed (Isotropic/kinematic) hardening. The consistent tangent matrix is also calculated. [less ▲]

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See detailTrace element bioaccumulation in rope-grown Mytilus galloprovincialis: knowledge update
Richir, Jonathan ULg; Gobert, Sylvie ULg

Poster (2014, May 12)

Numerous trace elements (TEs) can be considered as potential pollutants of the environment, their mining productions and industrial uses increasing worldwide. Their monitoring can be achieved through the ... [more ▼]

Numerous trace elements (TEs) can be considered as potential pollutants of the environment, their mining productions and industrial uses increasing worldwide. Their monitoring can be achieved through the use of bioindicator species, such as the Mediterranean mussel Mytilus galloprovincialis (Lamarck, 1819). That species has been widely used to monitor the chemical pollution of coastal ecosystems by Cr, Ni, Cu, Zn, Cd, Pb, As, Ag and V. Conversely, environmental levels of Be, Al, Fe, Mn, Co, Se, Mo, Sn, Sb and Bi have been little or not monitored so far in mussel watch programs. Bioaccumulation processes of these 19 TEs in rope-grown M. galloprovincialis purchased from a salt pond with good chemical water quality were thus investigated in the present study. Mussels efficiently accumulated the 19 studied TEs. Bioaccumulation processes were driven by numerous mutually dependent biological parameters such as the mussel size and flesh weight, the sex and the reproductive status and the body compartment considered. TE bioaccumulation was a power function of the mussel soft body dry weight; total contents linearly increased with the shell length. Small-size mussels overall concentrated more TEs, with a high interindividual variability, consequently influencing the modelling of their bioaccumulation in the whole rope population. Although a large range of rope-grown M. galloprovincialis sizes can be used for monitoring purposes, one will thus take care not to use extreme size individuals. The influence of gametogenesis in determining female body higher TE concentrations prior to spawning could not be neglected and varied depending on the element. TEs were preferentially accumulated in the hepatopancreas, except for Zn, Se, Cd and Mo, more concentrated in gills. Gametogenesis did not influence TE distribution between body compartments, but likely diluted their concentrations as a direct consequence of massive reproductive tissue production. So, results from the present study underlined the potential use of M. galloprovincialis in the biomonitoring of numerous little studied TEs and gave some insights into the decisive role played by some relevant biological parameters in bioaccumulation processes of the 19 investigated TEs in rope-grown mussels. [less ▲]

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See detailModeling of a glass mineral wool process in view of Life Cycle Analysis
Gerbinet, Saïcha ULg; Léonard, Angélique ULg; Briard, Vincent

Poster (2014, May 12)

In line with the growing concern about the environmental impact of materials in the building sector, Knauf Insulation, a glass wool producer, is performing environmental impact assessment of its products ... [more ▼]

In line with the growing concern about the environmental impact of materials in the building sector, Knauf Insulation, a glass wool producer, is performing environmental impact assessment of its products through LCA. Knauf Insulation has several glass wool factories in Europe that produce various products, and for a specific market, the same product can be produced in several factories. As the plants that produce glass wool work with similar pathways, a generic model for LCA usable for every plant and every glass wool product has been designed. Moreover, combination of different factories is also possible. The general principle of glass wool production is the following: the raw materials, sand, limestone, soda ash, borax, sodium carbonate, as well as recycled off-cuts from the production process, are weighed and mixed. Knauf Insulation also uses a large amount of recycled glass (cullet). The mix is sent to a furnace at high temperature (1350°C). The melted material is then fiberized and the binder is added, a process called forming. Knauf Insulation uses a special binder with ECOSE Technology, a new and formaldehyde-free binder. The wool fibers are collected, by suction, on a conveyor belt, and the mattress then goes through the curing oven. For some product a facing is added. Finally the product is compressed and packed. The model, implemented in GaBi 6, is made as generic as possible by including, for each step, all the raw materials that can be used in one of the factories as well as all the energy sources. Parameters allow to define the amount of each raw material consumed, therefore the model can be adapted to any factory simply by setting these parameters accordingly. This also simplifies the data collection, since the template is the same for all the factories, it can be supported by data collection tools already existing. A part of the model is dedicated to weighting between factories, so a combination of factories can also be studied. The model can also be adapted to almost all Knauf Insulation products by using parameters where necessary: for example, several products have different binder contents, so a parameter defines the amount of binder. As some materials can be recycled between several parts of the process, special attention has been paid to recycling loops inside the model. The model is flexible enough to be used for Environmental Product Declaration (EPD) as well as for Eco-Design purposes. [less ▲]

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See detailModeling using the SWAT model of water flow and transport in suspension in the watershed of the valley of Wadi El-Hachem
Tadrist, Nassima ULg; DEBAUCHE, OLIVIER ULg; Degré, Aurore ULg et al

Poster (2014, May 12)

In the Maghreb, dams regularly suffer from excessive siltation due to erosion problems present in the catchment areas. The origins of this erosion are multiple: land use, deforestation, land affectation ... [more ▼]

In the Maghreb, dams regularly suffer from excessive siltation due to erosion problems present in the catchment areas. The origins of this erosion are multiple: land use, deforestation, land affectation , ... Hydrology coupled with geographic information systems allows using distributed and physically based models to predict the evolution of siltation of dams. The application of these models in Algeria will finally predict the impact of anti-erosion measures, land use patterns on the siltation of dams accurately estimating the amount of sediment produced by erosion runoff and the degree of filling. A methodology based on the map data (digital terrain model, map soil science, geology map and mapping of land use) and daily meteorological data (temperature, relative humidity, wind speed, solar radiation) is being development and testing of the dam Bourkourdane. The SWAT model is used to predict the amount of sediment accumulating in the dam, the water flow rate inbound, outbound, and the volumes of water and sediment stored in the dam. Adequate management of releases, coupled with better management of erosion upstream of the dam will extend the life of dams Algerians. Especially for Boukourdane, improved management of releases is paramount to improve groundwater recharge, fight against the intrusion of marine waters and prevent the accumulation of fine particles that reduce soil permeability. [less ▲]

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See detailA clinical lab experience with an automated HIV Antigen/Antibody (Ag/Ab) combined assay
HUYNEN, Pascale ULg; TOUSSAINT, Françoise ULg; GERARD, Christiane ULg et al

Poster (2014, May 11)

OBJECTIVES: To describe the diagnostic performance of a new fourth-generation HIV Ag/Ab chemiluminescent immunoassay, available on the new LIAISON® XL analyser, in a clinical setting. METHODS: Through ... [more ▼]

OBJECTIVES: To describe the diagnostic performance of a new fourth-generation HIV Ag/Ab chemiluminescent immunoassay, available on the new LIAISON® XL analyser, in a clinical setting. METHODS: Through February 2012-October 2013, 12,438 samples of serum, received at our laboratory for screening for HIV infection were routinely tested with LIAISON® XL Murex HIV Ab/Ag assay (HIV-XL), which employs HIV-1, HIV-1 group O, and HIV-2 antigens and anti-p24 monoclonal antibodies in two coupled reagent cartridges, providing information of the overall Ab/Ag reactivity and detail of the specific reactivity for anti-HIV/HIV p24 antigen. Each serum with positive result or with negative result displaying a value close to the cut-off were sent to the regional AIDS-Reference Laboratory (RefLab) to perform confirmatory assays (PCR, Immunoblot). A previous verification of the HIV-XL demonstrated 100% sensitivity with a challenge panel of hundred positive sera provided by the RefLab. Performed external quality control was from United-Kingdom National External Quality Assessment Service (NEQAS). RESULTS: Out of the clinical samples, 12,312 non-reactive samples (including 6 negative results displaying a value close to the cut-off further confirmed true HIV negative), 64 Ab HIV reactive samples (all confirmed HIV-1 positive by immunoblot), including 4 samples reactive also for Ag HIV (confirmed positive by Ag assay/PCR), 42 Ab HIV reactive samples tested negative by immunoblot, and 20 Ag HIV reactive samples tested negative by the kit used for the Ag p24 detection in our HIV Reference Lab, have been found. All the 43 NEQAS specimens tested, 16 reactive and 27 non-reactive, were correctly classified. These results, considered all together, provide a calculated positive predictive value of 57.5% with an estimated specificity of 99.5% (with 95% confidence interval of 99.36-99.62%), and a calculated negative predictive value of 100% with an estimated sensitivity of 100.0% (with 95% confidence interval of 95.49-100%). CONCLUSIONS: In our experience HIV-XL showed excellent performance associated to all the advantages of a fully automated/random access instrument. [less ▲]

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See detailModeling information sharing in animal health surveillance with social network analysis
Delabouglise, Alexis; Dao Thi, Hiep; Nguyen Tien, Thanh et al

Poster (2014, May 08)

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See detailCOMPARISON AND MOLECULAR CHARACTERIZATION OF ANIMAL AND HUMAN CLOSTRIDIUM DIFFICILE STRAINS
Rodriguez Diaz, Cristina ULg; Taminiau, Bernard ULg; Korsak Koulagenko, Nicolas ULg et al

Poster (2014, May 07)

The main objective of this study was to characterize and compare animal and human C. difficile strains with respect to the PCR-ribotype and the antibiotic resistance. Multilocus sequence typing analysis ... [more ▼]

The main objective of this study was to characterize and compare animal and human C. difficile strains with respect to the PCR-ribotype and the antibiotic resistance. Multilocus sequence typing analysis (MLST) was performed in order to study clonal relationships of the isolates. [less ▲]

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See detailHas oxygen depletion an impact on nutrients and macrofauna in a highly dynamic macrophytodetritus accumulation?
Remy, François ULg; Mascart, Thibaud ULg; Dauby, Patrick ULg et al

Poster (2014, May 06)

Posidonia oceanica is an endemic Mediterranean highly productive seagrass. Depending on the ability of the primary consumers to digest it alive, a generally important part of its foliar primary production ... [more ▼]

Posidonia oceanica is an endemic Mediterranean highly productive seagrass. Depending on the ability of the primary consumers to digest it alive, a generally important part of its foliar primary production falls in autumn, to decay inside the meadow or to be exported to sand patches to form “exported litter accumulations”. These accumulations are highly dynamic depending on hydrodynamics and seafloor geomorphology. Literature says that low O2 conditions might occur inside litter accumulations, but the annual oxygen dynamics or its impact on the litter-associated macrofauna has never been measured. We focused on 2 exported litter accumulations in Calvi Bay (Corsica), during 2 years for a total of 8 seasons. For each season, we collected water samples (n=6) from 3 different strata: Water Column (WC), Water Just Above the litter (WJA) and Water Inside the litter (WI). Oxygen was measured for each replicate using a Winkler-based automated routine for oxygen concentration measurements on micro-volumes. At the same time, nutrients concentrations (PO4, NH4, and NO2+NO3) were measured in WC, WJA and WI, but also in the Interstitial Water (IW) using a spectrophotometric continuous flow analyzer (adapted for low nutrients level in an oligotrophic environment). In parallel, macrofaunal (size >500µm) samples (n=3-6) were also collected, counted and identified to the specific level. Our results show significant differences between O2 concentrations/saturation from WI and the two other strata. Significant differences were detected between seasons, sites and years for WI which is the only stratum where really low O2 conditions can be observed. Significant differences were also detected between seasons for both WC and WJA but no differences between sites and years. On the other hand no significant differences were detected between WC and WJA. A similar observation was made for the nutrients at the annual, seasonal and spatial level. Moreover differences are also observed between the nutrients themselves. Our data shows no correlation between WI O2 concentrations and saturation, and global macrofauna abundance or biodiversity. Results are more contrasting at an individual specific level for the 4 most dominant species. For two amphipod species, Gammarella fucicola (55% of the global abundance) and Gammarus aequicauda, no significant correlations were detected between their abundance and O2. For the leptostracan species, Nebalia strausi, a significant negative correlation with O2 concentration was detected. For the last amphipod species, Melita hergensis, a significant positive correlation was observed. Our analyses also show significant correlations between WI O2 concentration/saturation, and WI / IW nutrients concentration. To conclude, this work shows that WI is a very particular and dynamic environment considering O2 concentration and saturation. Low O2 conditions can be observed in WI but never in WC or WJA showing that internal processes and relations with the sediment determine the O2 dynamics in WI and showing a potential “barrier” effect between WI and WC. Moreover O2 dynamics and its consequences may play a role in the nutrients dynamics and cycles. It is clear that faunal responses to low O2 conditions are not identifiable at a global community level. At a specific level, we show a more complex situation: some species do not seem to be impacted by low O2 conditions, but some present a significant positive, or a significant negative response. This shows the existence and complexity of species-dependent low O2 tolerance/adaptation, and the importance of a specific level data analyses to detect responses of dominant litter associated macro- invertebrates to O2 concentration and saturation variations. [less ▲]

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See detailStudy of the microbial flora of steak tartare by metagenomic approach
Korsak Koulagenko, Nicolas ULg; Delhalle, Laurent ULg; Nezer, Carine et al

Poster (2014, May 06)

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See detailHypoxia in macrophytodetritus accumulation: Species specific harpacticoid copepod adaptation?
Mascart, Thibaud ULg; De Troch, Marleen; Gobert, Sylvie ULg et al

Poster (2014, May 05)

Mediterranean Posidonia oceanica seagrass meadows generate high primary production and support large biodiversity of associated fauna and flora. The majority of the foliar material falls on the ... [more ▼]

Mediterranean Posidonia oceanica seagrass meadows generate high primary production and support large biodiversity of associated fauna and flora. The majority of the foliar material falls on the unvegetated sea floor during the autumnal leaf senescence, fuelling the detrital food web. Whilst laying on the sea floor the freshly formed macrophytodetritus pile up into accumulations according to the local hydrodynamics and seafloor geomorphology. In these litter accumulations, harpacticoid copepods (Crustacea, Copepoda) are the main meiofaunal players (metazoans in the size range of 38µm – 1mm) and show a high specific diversity. They are primarily grazers, but their high specific diversity suggests that they occupy also a large variety of trophic niches. This large morphological and trophic diversity can partly be promoted by the complexity of the phytodetritus in seagrass accumulations. On the other hand, macrophytodetritus degradation and flux of reduced compounds from the sediments is responsible for oxygen consumption inside the accumulation of seagrass litter. Therefore, concentration of oxygen inside the accumulation is very variable and often under the concentration observed in the water column just above the litter. Frequently, oxygen levels reach very low values. The present study aims to link the oxygen variability inside the accumulation to the densities of the five most dominant harpacticoid copepods found living in the P. oceanica litter. Standardized samples were collected seasonally in two contrasting sites of the Calvi Bay (Corsica) during one year. Our results showed no correlation between the oxygen concentrations and harpacticoid community diversity or their total abundances. The five most dominant species showed divergent results, but none had a clear correlation with the oxygen concentration. This contrasts with observation done for sediment meiofaunal community where most harpacticoid copepods are sensitive to oxygen level and where nematodes often dominate the community. This could be explained by their high mobility and the patchiness and variability of the oxygen concentrations present in the accumulations. Harpacticoid copepods, whilst being sensitive to hypoxia and anoxia developed a strategy to live in this fast oxygen changing environment. To conclude, our results underline the importance of species-specific analysis of correlation data. Especially in complex and dynamic environments where a variety of potential trophic niches are present and species competition is very likely to occur. The overall abundance pattern and diversity of the copepod community showed no relation to the oxygen concentration while the most abundant copepod species did not responded to fluctuating oxygen concentrations. [less ▲]

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See detailCorrelation between the acoustic noise field measured in a Posidonia oceanica bed and the photosynthetic activity
Felisberto, P; Zabel, F; Rodriguez, O et al

Poster (2014, May 05)

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See detailRates of microbial sulfur oxidation in low oxygen environments
Crowe, SA; Canfield, DE; Sturm, A et al

Poster (2014, May 05)

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See detailAnaerobic methane oxidation in two tropical freshwater systems
Roland, Fleur ULg; Darchambeau, François ULg; Crowe, SA et al

Poster (2014, May 05)

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See detailAmmonia Oxidising Archaea in the OMZ of a freshwater African Lake
Lliros, M; Ingeoglu, O; Garcia-Armisen, T et al

Poster (2014, May 05)

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See detailHeroin-assisted treatment showed better efficacy than methadone
ANSSEAU, Marc ULg; Demaret, Isabelle ULg

Poster (2014, May 04)

Background: A fraction of patients receiving methadone treatment pursues their use of street heroin. In Switzerland, a new treatment with prescribed diacetylmorphine (pharmaceutical heroin) was developed ... [more ▼]

Background: A fraction of patients receiving methadone treatment pursues their use of street heroin. In Switzerland, a new treatment with prescribed diacetylmorphine (pharmaceutical heroin) was developed to help these heroin addicts resistant to methadone treatment to decrease their street heroin use. In this heroin-assisted treatment (HAT), diacetylmorphine is prescribed to severe heroin user and diacetylmorphine is administered by patients under the supervision of nurses in a specific centre. Six randomised controlled trials compared HAT to methadone treatment: in Switzerland, The Netherlands, Spain, Germany, Canada and United- Kingdom. HAT showed better efficacy than methadone. Patients used less street heroin, their health improved and their criminal behaviour decreased. A new trial assessed in Belgium the feasibility and efficacy of this treatment compared to methadone treatment. Methods: The TADAM (Treatment Assisted by Diacetylmorphine) was an open label randomised controlled trial developed on the Swiss model of HAT developed in 1994. Main inclusion criteria were 5 years of heroin addiction, (almost) daily use of street heroin and a previous attempt of methadone treatment. As in the Dutch experiment, patients could choose to inhale or to inject diacetylmorphine in the new HAT centre. HAT was stopped after 12 months and the best available treatment was offered to the patient. The research team assessed subjects every three months with standardised questionnaires (EuropASI, MAP-HSS, SCL-90-R) and questions on involvement in a criminal milieu. We completed our reported data with toxicological analysis and criminal proceedings. Results: 74 subjects were randomised in the trial: 36 in the experimental group and 38 in the control group. According to the primary efficacy criterion, the experimental group counted at least 30% more responders than the control group after 3 months (p<0.05), 6 months (p<0.05) and 9 months (p<0.01). At the 12 month assessment, the number of responders was still higher in the experimental group but the difference (11%) was no more significant (p=0.35). At the 12 month assessment, the condition of patients in the experimental group worsened compared to the 9 month assessment. This effect was not seen in the control group were patients could continue their methadone treatment after the 12 months. Conclusion: As in other countries, HAT is an effective treatment for severe heroin addicts resistant to methadone treatment. However, a predetermined duration of 12 month counteracts the efficacy of this treatment. [less ▲]

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See detailTropospheric jet stream as a source of traveling ionospheric disturbances observed by GPS
Wautelet, Gilles ULg; Warnant, René ULg

Poster (2014, May 02)

The integrity and the reliability of real-time precise positioning applications with Global Positioning System (GPS) are affected by the ionospheric variability with time and space. As a consequence ... [more ▼]

The integrity and the reliability of real-time precise positioning applications with Global Positioning System (GPS) are affected by the ionospheric variability with time and space. As a consequence, scientific community aims at describing, explaining and forecasting the occurrence and the amplitude of ionospheric irregularities observed by GPS. The use of the geometric-free combination of GPS dual frequency signals allows to retrieve the Total Electron Content (TEC) along the satellite-to-receiver path, which is the basic trans-ionospheric observable. Based on L1/L2 GPS phase measurements collected at a given station, the TEC high-frequency variability is isolated. A climatological study performed over 10 years in Western Europe shows that TEC irregularities are mostly observed daytime during quiet geomagnetic background in autumn and winter and correspond to classical Medium-Scale Traveling Ionospheric Disturbances (MSTIDs). The latter are generally understood as the ionospheric signature of Atmospheric Gravity Waves (AGWs), either generated in situ (solar terminator) or in the lower atmosphere and propagating upward. Because of its associated strong wind shears, the tropospheric jetstream, occurring mainly during autumn and winter months, constitutes an ideal candidate for AGW generation. This paper analyzes the spatial correlation between the presence of both MSTIDs and strong jetstream over Western Europe. This correlation is positive when the ionospheric pierce point of the satellite is located above regions of interest where wind shears are very large. In practice, we have selected regions for which wind speed is larger than 50 m/s. In addition, the propagation of AGWs up to the ionospheric layer is taken into account by assuming horizontal and vertical velocities of 200 and 50 m/s respectively. It comes that the region of interest of the correlation study is computed using an isotropic slant propagation of the AGW, which is supposed to be generated at a tropospheric level.Based on 30s GPS data collected over several stations in Belgium and on European Centre for Medium-Range Weather Forecasts (ECMWF) wind velocity maps, the correlation study covers a period ranging from January 2002 to December 2011. Preliminary results based on a limited number of cases show that large amplitude MSTIDs are generally observed during periods of strong wind speeds at an altitude corresponding to a pressure level of 250hPa (about 10 km). [less ▲]

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See detailEOF analysis of long-term reconstructed AVHRR Pathfinder SST in the South China Sea
Huynh, Thi Hong Ngu ULg; Alvera Azcarate, Aïda ULg; Barth, Alexander ULg et al

Poster (2014, May 02)

Sea surface temperature (SST) is one of the key variables often used to investigate ocean dynamics, ocean-atmosphere interaction, and climate change. For recent decades, the AVHRR Pathfinder SST, measured ... [more ▼]

Sea surface temperature (SST) is one of the key variables often used to investigate ocean dynamics, ocean-atmosphere interaction, and climate change. For recent decades, the AVHRR Pathfinder SST, measured by infrared sensors, has been widely used because of its high resolution and long time-series. The disadvantage of the AVHRR Pathfinder SST is high percentage of missing data due to cloud coverage. This becomes more serious in the South China Sea (SCS) because it is located in the tropical region, frequently covered by clouds. In this study, we used the Data INterpolating Empirical Orthogonal Functions (DINEOF) method to reconstruct daily night-time 4 km AVHRR Pathfinder SST spanning from 1989 to 2009 for the whole SCS. In order to better understand the spatial and temporal variability of the SCS SST, an EOF analysis of the reconstructed field is performed in association with surface wind. The first SST mode, accounting for 69% of the variance, presents the cooling (warming) of the basin due to the solar inclination through seasons, water exchange, topography, and monsoon-induced cyclonic circulation. The second SST mode, explaining 24.8% of the variance, shows the advection of cold and warm water from two opposite directions along the southwest-northeast diagonal of the basin. The second SST mode is affected by the atmospheric anticyclone (cyclone) located over the Philippine Sea. Comparing both SST modes with Nino3.0 index, it shows that the interannual variability of the SCS SST is influenced by the moderate and strong ENSO events with a lag of 5-6 months. Moreover, the analysis of the high-resolution reconstructed dataset reveals some oceanic features that could not be captured in previous EOF analyses. [less ▲]

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See detailEffect of metal nanoparticles encapsulated in porous silica on the biphenyl biodegradation by Rhodococcus erythropolis T902.1
Wannoussa, Wissal ULg; Hiligsmann, Serge ULg; Heinrichs, Benoît ULg et al

Poster (2014, May 01)

Biphenyl is stable and highly hydrophobic, thus having a low availability for degrading microorganisms, which need an aqueous environment for their growth. As a consequence, bioremediation processes are ... [more ▼]

Biphenyl is stable and highly hydrophobic, thus having a low availability for degrading microorganisms, which need an aqueous environment for their growth. As a consequence, bioremediation processes are very limited. However, a few studies showed that using a low metal concentration accelerates the biodegradation of pollutants (Yeom and Yoo1997). Nanoparticles are considered as a new generation of compounds to improve environmental remediation and biological processes (Beckers et al. 2013; Zhang 2003). This paper investigated the enhancement effect of nanometre-sized metallic Cu, Ag, Pd or Co, on the biphenyl biodegradation by Rhodococcus erythropolis T902.1. Have been synthesized by a sol–gel process (Lambert et al. 2004). These nanoparticles (NP) of about 2–3 nm were encapsulated in porous silica (SiO2) and were added at low concentration (10-4M) in the M284 minimal medium with 500 ppm biphenyl as source of carbon and energy. The cultures containing Pd or Co produced 30% more biphenyl degraded with a higher Rhodococcus growth than those without NP (positive control) or with silica particles only. On the contrary, the presence of 10-4 M Cu or Ag nanoparticles showed an inhibitory effect on bacterial growth and biphenyl degradation compared to the positive. [less ▲]

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See detailBias correction using data assimilation: Application on the Lorenz ’95 and NEMO-LIM models.
Canter, Martin ULg; Barth, Alexander ULg

Poster (2014, May 01)

Data assimilation has been used for decades in fields like engineering or signal processing to improve forecast models. Ensemble Kalman filters and other sequential data assimilation methods are examples ... [more ▼]

Data assimilation has been used for decades in fields like engineering or signal processing to improve forecast models. Ensemble Kalman filters and other sequential data assimilation methods are examples of developments which reduce the uncertainty of the model by taking observations into account. The widespread interest in addressing systematic forecast model errors only arose when the advances in modelling, data assimilation and computational power had reduced random errors to the point of commensurability with systematic errors, also known as bias. We present here a new method of bias correction using data assimilation. This method is based on the stochastic forcing of a model to correct bias. First, through a preliminary run, we estimate the bias of the model and its possible sources. Then, we establish a forcing term which is directly added inside the model’s equations. We create an ensemble of runs and consider the forcing term as a control variable during the assimilation of observations. We then use this analysed forcing term to correct the bias of the model. Since the forcing is added inside the model, it acts as a source term, unlike external forcings such as wind. This procedure has been developed and successfully tested with a twin experiment on a Lorenz 95 model. Indeed, we were able to estimate and recover an artificial bias that had been added into the model. This bias had a spatial structure and was constant through time. The mean and behaviour of the corrected model corresponded to those the reference model. It is currently being applied and tested on the sea ice ocean NEMO LIM model, which is used in the PredAntar project. NEMO LIM is a global and low resolution (2 degrees) coupled model (hydrodynamic model and sea ice model) with long time steps allowing simulations over several decades. Due to its low resolution, the model is subject to bias in area where strong currents are present. We aim at correcting this bias by using perturbed current fields from higher resolution models and randomly generated perturbations. [less ▲]

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See detailEVALUATION OF THE RAPID DETECTION OF ST-17 AND ST-1 GROUP B STREPTOCOCCI USING A MICROFLEX MALDI-TOF MS (BRUKER)
MEEX, Cécile ULg; SACHELI, Rosalie ULg; DESCY, Julie ULg et al

Poster (2014, May)

Objectives Clearly associated to neonatal meningitis, Group B streptococci (GBS) classified as sequence type-17 (ST-17) are defined as the “highly virulent” clone amongst GBS. The aim of this study was to ... [more ▼]

Objectives Clearly associated to neonatal meningitis, Group B streptococci (GBS) classified as sequence type-17 (ST-17) are defined as the “highly virulent” clone amongst GBS. The aim of this study was to evaluate an easy and rapid method, recently described to detect ST-17 and ST-1 GBS, based on distinguishing peak-shifts present on the protein spectrum of these 2 sequence types, using a Microflex (Bruker) matrix-assisted laser desorption/ionization time of flight mass spectrometer (MALDI-TOF MS). Methods This study was performed on 67 multi locus sequence typed (MLST) GBS originated from the Belgian and Czech National Reference Centers, including 18 ST-17 and 16 ST-1. After culture on blood agar, an ethanol/formic acid extraction was performed on each strain. Each extract was spotted once on a target plate, overlaid with 1 µl alpha-cyano-4-hydroxycinnamic acid matrix and further analysed by a Microflex MALDI-TOF MS. One spectrum per isolate was recorded, 240 laser shots being recorded for each spectrum. The spectra were further analysed using a Bruker prototype software, and 2 logarithmic values, one for ST-17 and one for ST-1, calculated from the intensities of the present and absent peaks, were obtained for each strain. If >0, this value indicated the presence of the specific sequence type. In a second step, the test was repeated on each strain with discordant result when compared with MLST. Results Compared with MLST method, the first analysis of the strains gave poor results, leading to very low sensitivities (77.8% for ST-17 and 50% for ST-1) but rather good specificities (85.7% for ST-17 and 98.0% for ST-1). After repeating the analysis on the strains with discordant result, sensitivity, 100% and 93.8%, and specificity, 87.8% and 98.0%, for ST-17 and ST-1 respectively were highly improved. Conclusion Since ST-17 and ST-1 GBS both show distinguishing peak-shifts on their protein spectrum, as described by Lartigue et al., the distinction of these 2 sequence types is now possible by MALDI-TOF MS. To our knowledge, this study is the first describing this application on a Microflex MS using a software to classify the strains. The observed results are promising but, given to the variability of the logarithmic value given by the software, the need to perform several measures on a same strain seems to be essential. After optimization of the analysis procedure, this rapid, easy and cheap method could be used to precociously detect ST-17 among GBS isolated from prenatal screenings, allowing a better follow up of the colonized mothers and a closer monitoring of their newborns. We would like to thank the Bruker Company which allowed us to evaluate the prototype software they have developed. [less ▲]

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See detailLong-term evolution and seasonal modulation above Jungfraujoch (46.5°N, 8.0°E): Optimisation of the retrieval strategy, comparison with model and independant observations
Bader, Whitney ULg; Stavrakou, J; Muller, J-F et al

Poster (2014, May)

Methanol (CH3OH) is the second most abundant organic compound in the Earth’s atmosphere after methane. In this work, we present the first long-term time series of methanol total, lower tropospheric and ... [more ▼]

Methanol (CH3OH) is the second most abundant organic compound in the Earth’s atmosphere after methane. In this work, we present the first long-term time series of methanol total, lower tropospheric and upper tropospheric-lower stratospheric partial columns derived from the analysis of high resolution Fourier transform infrared solar spectra recorded at the Jungfraujoch station (46.5°N, 3580 m a.s.l.). The retrieval of methanol is very challenging due to strong absorptions of ozone in the region of the selected 8 band of CH3OH. Two wide spectral intervals have been defined and adjusted in order to maximize the information content. Methanol does not exhibit a significant trend over the 1995-2012 time period, but a strong seasonal modulation characterized by maximum values and variability in June-July, minimum columns in winter and a peak-to-peak amplitude of 130 %. In situ measurements performed at the Jungfraujoch and ACE-FTS occultations give similar results for the methanol seasonal variation. The total and lower tropospheric columns are also compared with IMAGESv2 model simulations. There is no systematic bias between the observations and IMAGESv2 but the model underestimates the peak-to-peak amplitude of the seasonal modulations. [less ▲]

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See detailEvent justice and social entity justice: A cross-lagged analysis
Marzucco, Laurence ULg; Hansez, Isabelle ULg

Poster (2014, May)

ABSTRACT This study aimed to examine the directionality of the relationship between event justice and social entity justice. Using two samples and a cross-lagged panel analysis with two measurement times ... [more ▼]

ABSTRACT This study aimed to examine the directionality of the relationship between event justice and social entity justice. Using two samples and a cross-lagged panel analysis with two measurement times, social entity justice was found to predict event justice (procedural, distributive, interpersonal and informational justice event), supporting the top-down process. PRESS PARAGRAPH The life of organizations is punctuated by a wide range of managerial decisions (e.g., hiring, performance appraisal or organizational change). Facing such events, employees evaluate the fairness of the situation experienced. However, little is known about how employees develop justice judgments. This study shows that employees’ fairness perceptions about their organization influence their interpretation of the fairness of subsequent events involving the organization. Building and fostering a climate of justice is therefore of primary importance for organizations, since global fairness perceptions about the organization may help employees to perceive a specific event, such as a managerial decision, as being fair. [less ▲]

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See detailOutplacement adequacy and benefits: The mediating role of retrospective justice
Marzucco, Laurence ULg; Hansez, Isabelle ULg

Poster (2014, May)

ABSTRACT We examined the relationships between perceived outplacement adequacy, retrospective justice and outplacement benefits for redundant employees using outplacement services. Based on an ... [more ▼]

ABSTRACT We examined the relationships between perceived outplacement adequacy, retrospective justice and outplacement benefits for redundant employees using outplacement services. Based on an outplacement experience perceived as adequate, victims formed retrospective justice perceptions about their former organization that in turn, impacted their negative emotions, well-being, future perspectives and job search. PRESS PARAGRAPH The increasing prevalence of organizational downsizing has been matched by growth in the provision of outplacement services over the last decade. Despite this rapid growth and ongoing need for outplacement services, little is yet known about the perceived adequacy and the benefits of these services for redundant employees using them. Our results indicated that an outplacement experience perceived as adequate for redundant employees retrospectively fosters their impressions of justice about the dismissing organization; this leads in turn to satisfactory benefits for them: reduction of negative emotions, enhancement of their perceived well-being, future perspectives, and job-seeking activities. [less ▲]

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See detailDioxins and PCBs in eel and Chinese mitten crabs in the Rhine-Meuse estuary
van Hattum, B; Nijssen, P; Focant, Jean-François ULg et al

Poster (2014, May)

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See detailWork-home interference and well-being: A cross-lagged analysis.
Babic, Audrey ULg; Stinglhamber, Florence; Barbier, Marie ULg et al

Poster (2014, May)

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See detailCorrelation between composition and cold stability of palm liquid fractions.
Danthine, Sabine ULg; Lefebure, Emilie ULg; Dijkmans, Peggy et al

Poster (2014, May)

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See detailQuantitative multi-parameter mapping in parkinson’s disease: preliminary results
Rouillard, Maud ULg; D'Ostilio, Kevin ULg; Albinet, Cedric et al

Poster (2014, May)

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See detailSeeking for causes of recent methane increase: comparison between GEOS-Chem tagged simulations and FTIR column measurements above Jungfraujoch
Bader, Whitney ULg; Bovy, Benoît ULg; Wecht, K et al

Poster (2014, May)

Atmospheric CH4 reached 260% of the pre-industrial level (~700 ppb) due to increased emissions from anthropogenic sources. Globally averaged CH4 reached a new high of 1819 ± 1 ppb in 2012, an increase of ... [more ▼]

Atmospheric CH4 reached 260% of the pre-industrial level (~700 ppb) due to increased emissions from anthropogenic sources. Globally averaged CH4 reached a new high of 1819 ± 1 ppb in 2012, an increase of 6 ppb with respect to the previous year (WMO, Greenhouse gas Bulletin N.9, 2013). CH4 above Jungfraujoch increases at 0.53±0.19%/year during the late 90s to stabilize and reach a non significant trend from 2000 to 2005. Since 2006, atmospheric methane has been continuously increasing with a rate of 0.19±0.05 %/year. The attribution of this increase to any CH4 source is difficult since the current network is insufficient to characterize emissions by region and source process, emphasizing the need for source-tagged model simulations as it should provide us information on processes causing the increase of atmospheric methane since 2005/2006. [less ▲]

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See detailL'enfant placé au carrefour de ses appartenances
Aubinet, Suzanne ULg

Poster (2014, May)

Michard (2009) nous dit de la loyauté qu’elle est l’armature de l’appartenance et à Neuburger de souligner qu’en plus d’être un socle sur lequel l’identité se structure, l’appartenance contient et limite ... [more ▼]

Michard (2009) nous dit de la loyauté qu’elle est l’armature de l’appartenance et à Neuburger de souligner qu’en plus d’être un socle sur lequel l’identité se structure, l’appartenance contient et limite les effets des relations (2003). Pour Onnis (2008) c’est dans la dialectique entre identité et appartenance que naît l’individualité qui, elle, se réalise dans la relation (Dolto, 1988). Plymackers (2006) insiste sur les notions d’espaces où se nouent ces relations mais aussi de temps où ces dernières se jouent. L’enfant, par des mouvements dialectiques d’allées et venues avec son/ses système(s) d’appartenances tisse pas à pas les prémices de son identité. Ses relations structurent et étayent ce processus et la temporalité constitue le squelette de celui-ci. Mais qu’en est-il de ces enfants placés, maltraités, déplacés ? Qu’en est-il si le conflit ou le clivage de loyauté entre famille(s) et institution(s) rend l’étayage de l’appartenance ardu ? Qu’en est-il si la discontinuité des espaces et des relations prédomine et si le processus d’individuation est suspendu par une séparation arbitraire dictée par un autrui qui « n’appartient pas » ? L’analyse clinique de cas d’enfants aux vécus chaotiques rythmés par de nombreux placements nous permet de décortiquer les particularités de ce processus complexifié par ces ruptures d’espaces, ces loyautés morcelées, ces appartenances diffuses et d’en cerner les impacts. [less ▲]

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See detailSEDIMENTS OXIDATION BY SEAGRASSES: INFLUENCE ON THE S CYCLE IN POSIDONIA OCEANICA (L.) DELILE INTERMATTES DYNAMIC
Abadie, Arnaud ULg; Lejeune, Pierre; Pergent, Gérard et al

Poster (2014, May)

The Mediterranean seagrass Posidonia oceanica forms meadows and develops a complex of rhizomes, roots and sediment which is called “matte”. P. oceanica meadows show discontinuity patterns in the form of ... [more ▼]

The Mediterranean seagrass Posidonia oceanica forms meadows and develops a complex of rhizomes, roots and sediment which is called “matte”. P. oceanica meadows show discontinuity patterns in the form of sand or dead matte (matte without living shoots) patches, called “intermattes”, which can have natural or anthropogenic origins. Mechanical processes (e. g. currents, anchoring) can initiate intermattes formation but their dynamic after creation seems to be linked with the sediment chemistry, especially with S cycle. P. oceanica plays an important role in controlling coastal belowground biogeochemistry, in particular by oxidizing sediments through the release of O2 by roots. This process allows creating more suitable condition for plant growth and colonization. The lack of H2S oxidation in SO4 2- can lead to limitation of the plant development or its regression. In order to investigate the effect of oxidation condition in sediments on intermattes dynamic and the neighboring meadow, we initiate, in December 2013, a study on six intermattes (three natural, three anthropogenic) at different depths in Calvi Bay, in Corsica (France). We hypothesize that redox potential and H2S concentration in sediments play an important role in the regression of P. oceanica meadows, particularly after a mechanical anthropic impact like anchoring. It also may be possible that two different kinds of processes are involved for each type of intermatte. Regular samplings throughout two years are planed with the aim of evaluating the seasonal variations of physicochemical parameters. [less ▲]

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See detailA new analysis of the optical polarisation alignments of quasars
Pelgrims, Vincent ULg

Poster (2014, April 30)

Introduction of a new statistical method dedicated to the analysis of polarisation orientations and presentation of some results of its application to the sample of optical polarisation measurements of ... [more ▼]

Introduction of a new statistical method dedicated to the analysis of polarisation orientations and presentation of some results of its application to the sample of optical polarisation measurements of 355 quasars. [less ▲]

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See detailLD-based haplotype encoding scheme with iterative pruning principal component analysis (ipPCA) to retrieve population substructures
Chaichoompu, Kridsadakorn ULg; Fouladi, Ramouna ULg; Wangkumhang, Pongsakorn et al

Poster (2014, April 29)

Objective To identify and differentiate between subpopulations using a rich set of genetic markers, as using reduced sets of genetic markers for these purposes can become challenging, especially when ... [more ▼]

Objective To identify and differentiate between subpopulations using a rich set of genetic markers, as using reduced sets of genetic markers for these purposes can become challenging, especially when similar geographic regions are involved or when spurious patterns are likely to exist. Method Single Nucleotide Polymorphisms (SNPs) are commonly used to capture variations between populations and often genome-wide SNP data are pruned based on linkage disequilibrium (LD) patterns. Notably, haplotype composition and the pattern of LD between markers may vary between larger populations but may also play a role within more confined geographic regions. Indeed, knowledge about haplotypes in unrelated individuals can reveal useful information about genetic ancestry. Here, we use iterative pruning principal component analysis (ipPCA) [1] to identify and characterize subpopulations in an unsupervised way. As input data, either pruned genome-wide SNP data are used (using PLINK 1.9 with the "indep-pairwise" option, window size = 100k, r2 < 0.25) or multilocus haplotype information derived from the genome-wide SNP panel (using BEAGLE 3.3.2 to infer haplotype). These approaches are applied to real-life data from 992 Thai individuals [2]. Result Preliminary results indicate that ipPCA applied to pruned SNP data or ipPCA that explicitly uses multilocus information (haplotypes) give complementary information about population substructure for geographically confined populations such as the Thai samples in this study. Both methods address different aspects of population structure. Detailed simulation studies are needed to identify the optimal scenarios for haplotype-based ipPCA. Conclusion In this work, we propose to combine an LD-based haplotype encoding scheme with the ipPCA machinery to retrieve fine population substructures. Despite the complexities that are associated with haplotype inference, added value can be obtained when the LD structure between SNPs is exploited in the search for relevant population strata. References 1. Intarapanich, A., et al., Iterative pruning PCA improves resolution of highly structured populations. BMC Bioinformatics, 2009. 10: p. 382. 2. Wangkumhang, P., et al., Insight into the peopling of Mainland Southeast Asia from Thai population genetic structure. PLoS One, 2013. 8(11): p. e79522. [less ▲]

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See detailVadose zone studies at an industrial contaminated site: the vadose zone monitoring system and cross-hole geophysics
Fernandez de Vera, Natalia ULg; Beaujean, Jean ULg; Jamin, Pierre ULg et al

Poster (2014, April 29)

Poster presented at the European Geoscience Union General Assembly 2014. In this poster, the installation of the vadose zone experimental set up is presented along with first results

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See detailApplication of multi-scale variography for inferring the spatial variability of the hydraulic conductivity of a sandy aquifer
Rogiers, Bart; Vienken, Thomas; Gedeon, M et al

Poster (2014, April 28)

In the framework of the disposal of short-lived low- and intermediate-level radioactive waste in a near-surface disposal facility in Dessel (Belgium), extensive characterization of the hydraulic ... [more ▼]

In the framework of the disposal of short-lived low- and intermediate-level radioactive waste in a near-surface disposal facility in Dessel (Belgium), extensive characterization of the hydraulic conductivity (K) in the shallow Neogene aquifer has been performed at a regional scale. In the last few years the small-scale heterogeneity has been additionally characterized by outcrop analogue, hydraulic direct push, and borehole core air permeameter studies. The gathered data now include a) more than 350 hydraulic conductivity measurements on samples from 8 cored boreholes, mostly reaching depths of 50 m and data at 2 m intervals, b) more than 5000 air permeability measurements on the same borehole cores, c) more than 250 cone penetration tests (CPTs) with depths down to 40 m and data at 2 cm intervals, d) over 100 dissipation tests performed during the CPT campaigns, e) 17 direct push injections loggings, 6 hydraulic profiling tool logs, and 6 direct push slug tests, f) several hundreds of air permeability measurements on outcrop analogues of the aquifer sediments, and g) numerous grain size analyses. The current study aims to quantify the heterogeneity of K from the centimetre- to the kilometre-scale and to check the compatibility of the spatial variability revealed by the different datasets. This is achieved through gathering all K values (either direct measurements, calibrated relative K values, or K estimates from secondary data), and the use of variography to quantify spatial variability in terms of two-points geostatistics. The results are discussed, and the main differences between the different data sources are explained. In a final step, different multi-scale variogram models are proposed for capturing the main characteristics of multi-scale variability within the shallow Neogene aquifer in Belgium. [less ▲]

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See detailCharcoal records reveal past occurrences of perturbations in the forests of the Kisangani region(RDC): vegetation history of the semi-deciduous rainforest
Tshibamba Mukendi, John; Hubau, Wannes; Morin-Rivat, Julie ULg et al

Poster (2014, April 28)

Introduction. Past disturbances have modified the structure and the floristic composition of Central African rainforests. These perturbations represent a driving force for forest dynamics and they are ... [more ▼]

Introduction. Past disturbances have modified the structure and the floristic composition of Central African rainforests. These perturbations represent a driving force for forest dynamics and they are presumably at the origin of present-day forest mosaics. Fire is a prominent forest disturbance, leaving behind charcoal as a witness of past forest dynamics. The question arises whether quantification, dating and botanical identification of ancient charcoal fragments found in soil layers (pedoanthracology) allows a detailed reconstruction of forest history, including the possible occurrence of past disturbances. Material & methods. We organized pedoanthracological excavations in 6 regrowth sites and 48 sites of primary forests of Yangambi, Yoko, Masako and Kole in the Kisangani (RDC). We performed a detailed sampling in different vegetation types of a semi -deciduous rainforest (Yoko). Charcoal sampling was conducted in pit intervals of 10 cm. The charcoal was quantified whereby pottery fragments were also registered. A selection of charcoal fragments has been dated through AMS 14C measurement. Floristic identifications were conducted using. former protocols based on wood anatomy, which is largely preserved after charcoalification. Results. Charcoal was found in most pit intervals. The anthracomass in the soil of regrowth forests (secondary forests) is much higher than in the primary forest: 27,59 mg/kg for secondary forests et 2,53 mg/kg for primary forests. The specific soil anthracomass of the primary forest of the Yoko reserve is higher (7,7 mg/kg) than in Yangambi (1,9 mg/kg) , Masako (1,7 mg/kg) and Kole (0,8 mg/kg). No systematic differences have been found between soil charcoal content of the different forest type representing different forest histories. Gilbertiodendron dewevrei (De Wild.) J. Leonard forests showed surprisingly a higher concentration of soil charcoal. Discussion. Forest disturbances in the Kisangani region appear to be more recent than those in the Mayombe forest in Western RDC ( 3000-2000 calBP (Hubau, 2013)) and those of the Cameroon forest (2300-1300 calBP) (Morin-Rivat, J et al., 2014). Stratified charcoal conserved in the soil is a useful indicator of past forest disturbances. [less ▲]

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See detailAnaerobic methane oxidation in two tropical freshwater systems
Roland, Fleur ULg; Darchambeau, François ULg; Crowe, SA et al

Poster (2014, April 27)

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See detailCarbon cycling in a large, meromictic tropical lake (Lake Kivu, East Africa): insights from seasonal monitoring of biogeochemical depth profiles
Morana, C; Darchambeau, F; Muvundja, F et al

Poster (2014, April 27)

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See detailProduction of dissolved organic matter by phytoplankton and its uptake by heterotrophic prokaryotes in large tropical lakes
Morana, C; Sarmento, H; Descy, J-P et al

Poster (2014, April 27)

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See detailDrivers on carbon dioxide emissions from the Scheldt river basin
Gypens, N; Passy, P; Garnier, J et al

Poster (2014, April 27)

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See detailEutrophication counteracts ocean acidification effects on DMS emissions
Gypens, N; Borges, Alberto ULg

Poster (2014, April 27)

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See detailInorganic and organic carbon spatial variability in the Congo River during high waters (December 2013)
Borges, Alberto ULg; Bouillon, S; Teodoru, C et al

Poster (2014, April 27)

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See detailCirculating microRNAs as diagnostic markers in breast cancer patients and their deregulation under neoadjuvant chemotherapy
FRERES, Pierre ULg

Poster (2014, April 24)

Breast cancer is the leading cause of death by cancer among women and there is an urgent need to improve its diagnosis and prognosis. MicroRNAs (miRNAs) are non-coding RNAs that regulate gene expression ... [more ▼]

Breast cancer is the leading cause of death by cancer among women and there is an urgent need to improve its diagnosis and prognosis. MicroRNAs (miRNAs) are non-coding RNAs that regulate gene expression and many have been implicated in breast cancer. In this article, we focus on circulating miRNAs as biomarkers for breast cancers and we describe the deregulation of their expression during neoadjuvant chemotherapy (NAC). [less ▲]

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See detailStudies of the Domains II and III of Bacillus subtilis PBP4a in relation with the protein localization
Vanden Broeck, Arnaud ULg; Van Der Heiden, Edwige ULg; Sauvage, Eric ULg et al

Poster (2014, April 23)

Bacillus subtilis PBP4a belongs to the class-C1 PBPs characterized by two internal additional domains of unknown function. Seven lysine residues (K) are protruding from domain II. Four of them have been ... [more ▼]

Bacillus subtilis PBP4a belongs to the class-C1 PBPs characterized by two internal additional domains of unknown function. Seven lysine residues (K) are protruding from domain II. Four of them have been mutated in glutamine residues (Q). Both proteins (WT and Mut4KQ PBP4a) have been produced without signal peptide in E. coli and their sub-cellular localizations determined by measuring the DD-carboxypeptidase activities in the different compartments (cytoplasmic vs membrane attached proteins). In order to detect a possible influence of the PBP4a domain III in the localization of the protein, its encoding sequence has been cloned into pET-28b-BlaP, a vector allowing the production of WT BlaP β-lactamase or BlaP/DIII chimeric protein (with domain III inserted in a permissive loop of BlaP). The nitrocefin hydrolysis activities of BlaP or BlaP/DIII have been measured in the different cellular compartments. [less ▲]

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See detailSpatio-Temporal Analysis of Equatorial Ionospheric Scintillations in the Frame of Absolute GNSS Positioning Algorithms
Lonchay, Matthieu ULg; Cornet, Yves ULg; Aquino, Marcio et al

Poster (2014, April 23)

The ionosphere has always been a major limitation for GNSS positioning applications. Free electrons in the ionosphere perturb the propagation of GNSS radio signals involving both refraction and ... [more ▼]

The ionosphere has always been a major limitation for GNSS positioning applications. Free electrons in the ionosphere perturb the propagation of GNSS radio signals involving both refraction and diffraction effects. The ionospheric refraction mainly results in a modification of the propagation speed of the GNSS electromagnetic signals, inducing an error (propagation delay or phase advance depending on the observable) in GNSS measurements. In the frame of absolute positioning techniques, single-frequency algorithms usually exploit an ionospheric model to mitigate the ionospheric error while dual-frequency algorithms, such as the well-known Precise Point Positioning (PPP), take the benefit of the availability of two frequencies and the fact that the ionosphere is a dispersive medium to construct an ionosphere-free mathematical model. But these two strategies are not able to counteract the effect of the ionospheric diffraction which is due to small-scale irregularities in the free electron density. By scattering GNSS signals, these irregularities generate rapid fluctuations (scintillations) in the amplitude and phase of GNSS signals with critical consequences for GNSS applications: cycle slips, signal power fading, receiver loss of lock and poor resulting satellite geometry. The goal of our research is to develop a strategy to mitigate the effect of ionospheric scintillations on absolute GNSS positioning techniques, in particular the SPP (Standard Point Positioning) and the PPP (Precise Point Positioning). The strategy is based on the adjustment of the stochastic model. In order to construct the stochastic model (diagonal and non-diagonal elements) and study the correlation between observables, we adopted a “spatial” and an “empirical” approach. The spatial approach consists in a study of the spatial autocorrelation existing in scintillations effects on GNSS signals. The spatial autocorrelation is detected by using specific spatial analysis techniques applied on data from a network of ISMR (Ionospheric Scintillation Monitoring Receiver) stations located at equatorial and polar latitudes, where scintillations effects are most severe. The knowledge of how scintillation effects are spatially correlated is helpful for determining a coherent stochastic model. The empirical approach does not take into account the phenomenon spatiality and the locations of the measurements but only the observation data. Its objective is to determine the statistical correlation which exists between GNSS measurements during a scintillation event by using a moving filter applied on GNSS observation and scintillation data. The spatial approach exploits data and data locations while the empirical approach is based only the data itself. [less ▲]

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See detailRéaction immédiate à l'alcool
LIBON, Florence ULg; DEZFOULIAN, Bita ULg; NIKKELS, Arjen ULg

Poster (2014, April 17)

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See detailLo sviluppo socio-emotivo dei bambini adottati da coppie omosessuali in Europa
Messina, Roberta ULg; D'Amore, Salvatore ULg; J-Green, Robert

Poster (2014, April 10)

L’adozione da parte di coppie omosessuali, legale in 9 paesi europei, provoca molte reazioni nell’opinione pubblica. Il dibattito oppone il “diritto al bambino”, reclamato dagli omosessuali, al “diritto ... [more ▼]

L’adozione da parte di coppie omosessuali, legale in 9 paesi europei, provoca molte reazioni nell’opinione pubblica. Il dibattito oppone il “diritto al bambino”, reclamato dagli omosessuali, al “diritto del bambino” di crescere al sicuro da ogni forma di stigmatizzazione. La presente ricerca, pionieristica nel contesto europeo, mira ad approfondire lo sviluppo socio-emotivo dei bambini adottati da coppie dello stesso sesso. L’obiettivo è rispondere all’interrogativo soggiacente al dibattito sociale: “inserire un bambino, già segnato da un abbandono, in una famiglia che rappresenta un nuovo “cantiere sociale” può comportare delle ripercussioni sul suo benessere psicologico?”. Recruteremo circa 200 famiglie adottive, metà omogenitoriali e metà eterogenitoriali; per ogni famiglia, i dati saranno raccolti tramite tre fonti di informazione: i genitori, il bambino e un suo insegnante. La ricerca, condotta inizialmente in Olanda, Belgio, Spagna e Inghilterra, sarà poi diffusa negli altri paesi europei. [less ▲]

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See detailPhylogenetic study of Aedes albopictus and Aedes koreicus (Diptera, Culicidae) origin, two invasive mosquito species in Belgium
Raharimalala, Fara Nantenaina ULg; Boukraa, Slimane ULg; Bawin, Thomas ULg et al

Poster (2014, April 10)

The main ways of the introduction of invasive mosquito species in Europe were greatly facilitated by the importation of used tires and plants from the South of China (Dracaena sanderiana, called "Lucky ... [more ▼]

The main ways of the introduction of invasive mosquito species in Europe were greatly facilitated by the importation of used tires and plants from the South of China (Dracaena sanderiana, called "Lucky bamboo"), which are a very good breeding sites of these mosquitoes (www.eidatlantique.eu). For Belgium, several species of exotic mosquitoes have already been listed such as Ochlerotatus japonicus japonicus, Aedes albopictus and A. koreicus. We have captured one male of A. albopictus in Belgium in July 2013 (Boukraa et al, 2013), and teams from other entomologist have been able to find several individuals in the months that have followed our discovery (personal communication). However, his presence was reported first in 2000 (Schaffner et al. 2004) but until 2012, no individuals have been found (Versteirt et al., 2013). We also could find larvae of A. koreicus in abundance. These discovery suggest that these two invasive species are being established in Belgium. Methods: Adult mosquitoes were collected by CO2-baited traps Mosquito Magnet Liberty Plus (MMLP) and immature stages by the dipping method from 8 sites of Belgium. Each individual was then determined morphologically. For A. albopictus and A. koreicus, reconfirmation by molecular method was performed with COI and ND5 mitochondrial primers and sequences were then aligned with those of mosquitoes available in databases by using BioEdit and Multialn softwares. The two gene sequences were concatenated to improve the reliability of the phylogenetic analysis and were carried out by using the Seaview software based on maximum likelihood (ML) methods. Trees were then constructed with the general time reversible (GTR) model, and branch supports were estimated by bootstrapping with 1000 replicates. Result: The aim of this work will focus on the study of the probable origin of these two species of Aedes, which are for the moment safe yet, but that might become dangerous in the event of massive outbreak. The knowledge of the probably origin of the two invasive mosquitoes allow take more protection against their way to enter in the country. [less ▲]

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See detailSame-sex parenting is legal in Belgium but some heterosexuals support it and others don't: why?
Scali, Thérèse ULg; D'Amore, Salvatore ULg; Green, Robert-Jay

Poster (2014, April 10)

Gays and Lesbians represent between 7 and 10% of the Belgian population, this means 1 million of citizens. Notwithstanding the large number of civil rights granted to homosexuals and the anti ... [more ▼]

Gays and Lesbians represent between 7 and 10% of the Belgian population, this means 1 million of citizens. Notwithstanding the large number of civil rights granted to homosexuals and the anti-discrimination laws, the issue of social acceptance of same-sex couples and families remains. However, the attitude of the population (support vs. rejection and discrimination) and the marginalization of a minority influence not only their quality of life but also their couple and parenting skills and the development of their children (Armesto, 2002; Goldberg, 2010). Results show that attitudes towards same-sex parenting can be explained by four categories of arguments: arguments regarding children well-beeing, religious and political arguments, contact and experiential arguments and traditional arguments. [less ▲]

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See detailHabitat use of a population of bottlenose dolphins, Tursiops truncatus gephyreus, analyzed by means of Kernel Density Estimation (KDE) method
Cransveld, Alice ULg; Denoël, Mathieu ULg; Das, Krishna ULg et al

Poster (2014, April 09)

The San Antonio Bay (SAB), in Patagonia, Argentina, harbors a resident population of bottlenose dolphins (Tursiops truncatus gephyreus). It seems a privileged area to give birth and nurse calves. In the ... [more ▼]

The San Antonio Bay (SAB), in Patagonia, Argentina, harbors a resident population of bottlenose dolphins (Tursiops truncatus gephyreus). It seems a privileged area to give birth and nurse calves. In the context of declining populations worldwide and more particularly in South America, preserving the SAB population takes a considerable significance. Yet the SAB is facing human population growth and touristic development, which represent potential threats for the dolphin population, especially dolphin-watching activities. In this context, the aim of this study was to understand the bottlenose dolphin’s habitat use within the bay, and to consider how this information could be used in prospective management strategies. Particularly, we aimed at using the Kernel Density Estimation (KDE) method to map the intensity of space use for essential behavioural patterns. To this end, we collected behavioural information on dolphins during 25 boat-based surveys in the bay in 2011. The habitat use of the bay was heterogeneous: some areas were more intensely used than others. Dolphins spent most of their time traveling and diving. Variables associated to resting behaviours, e.g. school size and depth, indicated that the SAB would be a safer place compared to other known residency areas, confirming its suitability for conservation purposes. KDE analyses showed that behaviours are not evenly distributed inside the bay. Bottlenose dolphins being more sensitive to anthropogenic disturbances while engaged in resting or socializing behaviours, it is crucial to locate these behaviours. In SAB, the KDE shows that resting and socializing areas are located in the Northern part of the bay, indicating that it should constitute a priority protected area in potential future management strategies. Furthermore, our results show that the KDE method is an appropriate and advantageous tool when determining critical habitats, worth being more widely used. [less ▲]

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See detailProbing the conformational changes during desolvation of ions using orthogonal mobility methods (CE-IMS)
Far, Johann ULg; Kune, Christopher ULg; Delvaux, Cédric ULg et al

Poster (2014, April 08)

The transfer of ions from the solution to the gas phase is a critical step to produce « native species ». Coming from a highly solvating medium, ionic species will tend to find a new equilibrium ... [more ▼]

The transfer of ions from the solution to the gas phase is a critical step to produce « native species ». Coming from a highly solvating medium, ionic species will tend to find a new equilibrium conformation in the gas phase. The pathway to reach the thermodynamically stable conformation involves crossing potential barriers of different heights. When these barriers are too high compared to the internal energy of the ions, it will result in “partial memories” (as structural preservation) of the conformation in solution. In order to evaluate the effect of the solvent evaporation and of the various collision processes encountered by the ions in the mass spectrometer. The strategy consists in comparing in a single experiment the shape of the ions in solution and in the gas phase. Data are obtained by coupling capillary electrophoresis with Ion Mobility Mass Spectrometry. Drift times in solution and in the gas phase are directly compared. Deviations from their correlation points out changes in folding upon desolvatation. Preliminary results show that among peptides issued from tryptic digest of BSA some of them clearly change their conformation during desolvatation. This work intends to evaluate the extent of conformational “memory” of the ions of different nature for best experimental condition allowing “native mass spectrometry”. [less ▲]

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See detailMultitasking capacities in persons diagnosed with schizophrenia: A preliminary examination of their neurocognitive underpinnings and ability to predict real world functioning
Laloyaux, Julien ULg; Van der Linden, Martial ULg; Levaux, Marie-Noëlle ULg et al

Poster (2014, April 08)

Background: Difficulties in everyday life activities are core features of persons diagnosed with schizophrenia. Moreover, patients seem to demonstrate particular difficulties during complex and ... [more ▼]

Background: Difficulties in everyday life activities are core features of persons diagnosed with schizophrenia. Moreover, patients seem to demonstrate particular difficulties during complex and multitasking activities, such as cooking a meal (Semkovska et al., 2004). Multitasking refers to activities where the person has to: carry out and alternate between different tasks that vary in terms of priority, difficulty and duration; define the tasks’ targets; and where the person is faced with unexpected problems during the realization of these tasks (Burgess, 2000). However, at present, patients’ multitasking capacities have not been adequately examined in the literature due to an absence of suitable assessment strategies. We thus recently developed a computerized real-life activity task designed to take into account the complex and multitasking nature of certain everyday life activities where participants are required to prepare a room for a meeting – the Computerized Meeting Preparation Task (CMPT) Methods: Twenty-one individuals diagnosed with schizophrenia and 20 matched healthy controls completed the CMPT. During the CMPT, participants found themselves in a virtual room that they had to prepare for a meeting while respecting a list of instructions (the placement of the guests, the needed objects, the desired drinks, etc.). Patients were also evaluated with an extensive cognitive battery (assessing executive functions, attention, processing speed and memory), measures of symptomatology and real world functioning. To examine the ecological validity of the CMPT, 14 others patients were recruited and were given the computerized version and a real version of the meeting preparation task. Results: Results demonstrated that performance on the CMPT significantly differentiated patients and healthy controls for the total time to complete task, planning efficiency, and the respect of the instructions. Moreover, these variables were significantly correlated with executive functioning (i.e. cognitive flexibility and planning), suggesting the major implication of these cognitive processes in multitasking activities. Performance on the CMPT also significantly predicted up to 50% of real world functioning. Finally, performances on the computerized version and the real version of the meeting preparation task were highly correlated, suggesting good ecological validity. Discussion: In this study, we created a novel task involving the multitasking nature of real world activities. The results demonstrated that this approach provides a good indication of the real world functioning in patients diagnosed with schizophrenia. Moreover, results suggest a particular implication of executive functioning in multitasking activities. These findings suggest the importance of evaluating multitasking capacities in patients diagnosed with schizophrenia in order to predict real world functioning. [less ▲]

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See detailEfficacité des interven8ons langagières basées sur la guidance parentale : qu’en est- il pour les popula8ons de faible statut socio-économique (SSE)?
Maillart, Christelle ULg; Martinez Perez, Trecy ULg; Jidovtseff, Boris ULg et al

Poster (2014, April 07)

Le développement langagier de l’enfant est fortement influencé par le statut socio-économique (SSE). Dès le plus jeune âge, les enfants issus de milieux défavorisés présentent un retard langagier ... [more ▼]

Le développement langagier de l’enfant est fortement influencé par le statut socio-économique (SSE). Dès le plus jeune âge, les enfants issus de milieux défavorisés présentent un retard langagier objectivable (Hoff, 2012). La qualité et la quantité du langage adressé à l’enfant sont des variables médiatrices dans l’impact du SSE (Hoff, 2003). Une méta-analyse a mis en évidence l’efficacité des interventions langagières ciblées sur l’enrichissement du langage adressé à l’enfant (Robert & Kaiser, 2011). Toutefois, les études d’intervention ont principalement porté sur des enfants issus de SSE moyen : il est difficile d’en généraliser la portée aux populations plus défavorisées. Cette étude randomisée contrôlée évalue l’efficacité d’une intervention ciblée sur le langage adressé à l’enfant dans des populations de faible SSE. Participants Quatre-vingt-seize enfants âgés de 18 à 30 mois et de faible SSE ont été recrutés au sein de 10 consultations enfants organisées par l’Office de la Naissance et de l’Enfance, en Belgique. Dans 5 de ces 10 consultations, une intervention portant sur la stimulation langagière a été proposée. Dans les 5 autres, une intervention en psychomotricité a été mise en place. Les deux interventions se déroulent en groupe (une dizaine d’enfants et leur parent) et sont appariées en termes de fréquence (1 heure par semaine) et de durée (15 semaines). Une évaluation individuelle a été proposée avant l’intervention (T1), après l’intervention (T2) et 6 mois après la fin de l’intervention (T3). Chaque testing évaluait les développements cognitif, langagier et psychomoteur de l’enfant et comportait une interaction filmée parent-enfant en situation de jeu afin d’analyser le langage adressé à l’enfant et les comportements parentaux. Principaux résultats Les résultats mettent en évidence l’efficacité et la spécificité de l’intervention langagière proposée, tant au niveau du langage des enfants que des modifications du comportement parental. [less ▲]

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See detailDevelopmental Invariance in Implicit Sequence Learning
Lejeune, Caroline ULg; Wansard, Murielle ULg; Meulemans, Thierry ULg

Poster (2014, April 05)

This study was intended to test the age invariance hypothesis on implicit learning abilities using the serial reaction time paradigm and focusing on the comparison of second-order conditional (SOC ... [more ▼]

This study was intended to test the age invariance hypothesis on implicit learning abilities using the serial reaction time paradigm and focusing on the comparison of second-order conditional (SOC) sequences of two different lengths (8 and 12 elements). A total of 128 participants from 4 age groups (4 years, 7 years, 10 years, and adults) were tested. The results showed significant and similar learning effects in 4-, 7-, and 10-year-old children, as well as adults. The learning effect was more pronounced for the 8-element sequence than for the 12-element sequence for all age groups, suggesting that the shorter sequence was better learned than the longer one. In addition, the degree of explicit sequence awareness was comparable between age groups and sequence lengths. These results, showing that 4-year-old children are able to learn 8- and 12-element-long SOC sequences as well as adults, provide further support for the hypothesis that implicit learning abilities are developmentally invariant. [less ▲]

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