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See detailImportance of pigtailed macaques (Macaca nemestrina leonina) in seed dispersal and impact on the ecological balance of the tropical rainforest at Khao Yai National Park, Thailand
Albert, Aurélie ULg; Huynen, Marie-Claude ULg

Poster (2009, February)

The tropical rain forest is maintained thanks to a precarious balance placed under the yoke of interactions between the various animal and plant species which compose it. Among them we can find those ... [more ▼]

The tropical rain forest is maintained thanks to a precarious balance placed under the yoke of interactions between the various animal and plant species which compose it. Among them we can find those implying plants and frugivores. Although its diet is largely frugivorous, the pigtailed macaques (Macaca nemestrina leonina) have often been categorized as seed predators. However their morphology, behaviour and ecology suggest they could actually be a key-species in the dispersion of many plant species. A preliminary study by Latinne & al (2007) supported this hypothesis. The study we are planning now in continuity of Latinne’s study will take place in the Khao Yai National Park, Thailand, for three years and will focus on a troop habituated to humans. In order to establish the importance of the pigtailed macaques in the maintenance and the regeneration of the tropical rain forest, we will try to evaluate their capacity of being good seed dispersers. To do so, we will study: 1) the spatiotemporal distribution, the productivity and the characteristics of the plant species present on the home range of the studied troop, 2) the ranging patterns of the macaques within their home range, 3) their feeding behaviour, notably the fruit selection and the various modes of processing seeds, and finally 4) their impact on the viability and the germination potential of seeds. This study will require both direct observations of the macaques and semi-experimental procedures in the field, as well as laboratory control of some seed parameters. We hope the clarification of the macaques’ seed dispersal behaviour would help to re-evaluate their conservation status by recognizing them a paramount role in the maintenance of the tropical rainforest. [less ▲]

Detailed reference viewed: 19 (0 ULg)
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See detailEpidemiological study on European cases of atypical myopathy
Van Galen, Gaby ULg; Votion, Dominique ULg; Atypical Myopathy Alert Group

Poster (2009, January 28)

Detailed reference viewed: 102 (14 ULg)
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See detailGreenland ice sheet surface mass balance projections from IPCC AR4 global models
Franco, Bruno ULg; Fettweis, Xavier ULg; Erpicum, Michel ULg

Poster (2009, January 28)

Results from atmosphere-ocean general circulation models (AOGCM's) for the IPCC 4th Assessment Report are used to investigate surface mass balance (SMB) future projections of the Greenland ice sheet (GrIS ... [more ▼]

Results from atmosphere-ocean general circulation models (AOGCM's) for the IPCC 4th Assessment Report are used to investigate surface mass balance (SMB) future projections of the Greenland ice sheet (GrIS). The most efficient models for the GrIS climate modeling are chosen by comparison between the 1970-1999 outputs (averages and trends) from the Climate of the twentieth Century Experiment (20C3M) and reanalyses (ECMWF, NCEP) as well as observations (ice core measurements). The outputs from these most efficient models are after used to assess changes planned by the IPCC greenhouse gas emissions scenarios (SRES) for the 2070-2099 period. The GrIS SMB projections are estimated from changes in precipitation and temperatures from these AOGCM's outputs. However, large uncertainties remain in these SMB projections based on simplified physics and huge model outputs. High resolution simulations made with regional models (which simulate explicitly the SMB by taking into account the surface feedbacks) forced at their boundaries by a GrIS well-adapted AOGCM could bring more precise brief replies. [less ▲]

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See detailUse of C & N stable isotopes to evaluate interspecific trophic diversity among amphipods from Posidonia oceanica meadows
Michel, Loïc ULg; Lepoint, Gilles ULg; Nyssen, Fabienne ULg et al

Poster (2009, January 27)

Amphipods are one of the most diverse and abundant taxa of vagile invertebrates associated to Mediterranean Posidonia oceanica meadows. Therefore, they likely play an essential part in those ecosystems’ ... [more ▼]

Amphipods are one of the most diverse and abundant taxa of vagile invertebrates associated to Mediterranean Posidonia oceanica meadows. Therefore, they likely play an essential part in those ecosystems’ functioning, notably in organic matter transfers from producers to higher level consumers. Nevertheless, their trophic ecology remains poorly known, and they are generally regarded as epiflora grazers or generalist detritivores. Here, we focused on interspecific trophic diversity, and on the importance of other food sources (epifauna, Posidonia leaves & litter, suspended organic matter, …) in those amphipod’s diet. To achieve these goals, we used C and N stable isotopes ratios as trophic tracers. We noticed considerable trophic diversity among amphipods from different species, with δ13C values ranging from -16 to -26 ‰. Moreover, while some species (such as Apherusa chiereghinii and Aora spinicornis) seem to feed mainly on epiphytes, others, like Dexamine spiniventris, exploit other food sources. This study enhances the comprehension of the feeding ecology of these amphipods, and therefore of the way they interact with the Posidonia meadow ecosystem. [less ▲]

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See detailGround-based CO observations at the Jungfraujoch from 1997 till 2007: Comparison between FTIR and NDIR measurements
Dils, Bart; Demoulin, Philippe ULg; Mahieu, Emmanuel ULg et al

Poster (2009, January 26)

Here we will discuss CO measurements taken at the Swiss Alpine Jungfraujoch station (46.5º N, 8.0° E, 3580m a.s.l.) over the 1997-2007 time period. Results from two distinct techniques, namely Fourier ... [more ▼]

Here we will discuss CO measurements taken at the Swiss Alpine Jungfraujoch station (46.5º N, 8.0° E, 3580m a.s.l.) over the 1997-2007 time period. Results from two distinct techniques, namely Fourier Transform Infrared solar absorption spectrometry (FTIR), and the in situ Nondispersive Infrared technique (NDIR) have been compared. While the in situ NDIR measurements detect local CO concentrations at the site, the FTIR technique provides integrated measurements along the line-of-sight. Nevertheless, the pressure broadening of the spectral absorption lines recorded at high resolution enables retrieving information on the vertical distribution of CO, mainly in the troposphere, including its concentration near the surface. To provide enough information content the averaged vmr between 3.58 and 7 km is derived from the FTIR profile data. Both datasets show a significant negative trend over the time period. However, the NDIR dataset's negative trend is much stronger. Pettitt change point tests reveal that the NDIR-FTIR bias changes substantially from 1997 till 2004 after which the bias stabilizes. Possible causes for these observations will be critically discussed. [less ▲]

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See detailStoichiometry of bacteria and algae in Lake Kivu
Homblette, Nathalie; Darchambeau, François ULg; Heldal, Mikal et al

Poster (2009, January 25)

Detailed reference viewed: 12 (0 ULg)
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See detailDynamics of polysaccharides and transparent exopolymer particles during a coccolithophorid bloom in the Bay of Biscay
Händel, Nicole; Piontek, Judith; Harlay, Jérôme ULg et al

Poster (2009, January 25)

Carbohydrates comprise a large fraction (~30 %) of organic matter in the ocean (Pakulski and Benner, 1994). The production of polysaccarides (CCHO) in seawater is mainly linked to autotrophic processes ... [more ▼]

Carbohydrates comprise a large fraction (~30 %) of organic matter in the ocean (Pakulski and Benner, 1994). The production of polysaccarides (CCHO) in seawater is mainly linked to autotrophic processes. CCHO serve as structural and storage compounds, or are released by exudation, cell lysis or leakage to the dissolved organic matter pool. Concentrations of total hydrolyzable neutral sugars range from 200-800nM and 20-170nM in surface and deep waters, respectively (Benner, 2002). It has been shown that CCHO, in particular acidic polysaccharides, are involved in aggregation processes, e.g. the formation of transparent exopolymer particles (TEP). Recently, it has been suggested that ocean acidification increases TEP production, and therefore potentially enhances particle aggregation (Engel 2002, Mari 2008). Here, we present data on the abundance and composition of neutral and acidic CCHO and on TEP, obtained from field investigations and from CO2-controlled chemostat experiments that were conducted during a coccolithophore bloom in the Bay of Biscay 2006. Based on our findings, we discuss the partitioning of CCHO into gel particles, potential effects of ocean acidification and related consequences for organic matter export. [less ▲]

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See detailNutrient limitation of algae and bacteria in Lake Kivu (East Africa)
Darchambeau, François ULg; Leporcq, Bruno; Homblette, Nathalie et al

Poster (2009, January 25)

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See detailTowards a comprehensive C-budgeting approach of a coccolithophorid bloom in the Northern Bay of Biscay (June 2006)
Harlay, Jérôme ULg; Borges, Alberto ULg; De Bodt, Caroline et al

Poster (2009, January 25)

A biogeochemical multidisciplinary survey was carried out in the northern Bay of Biscay, in early June 2006, during which 14C-based primary production and calcification were determined as well as O2-based ... [more ▼]

A biogeochemical multidisciplinary survey was carried out in the northern Bay of Biscay, in early June 2006, during which 14C-based primary production and calcification were determined as well as O2-based community respiration. Contemporary remote sensing images showed several patches of high reflectance (HR) in the investigated area. Based on remote sensing and in situ measured biogeochemical parameters, the area exhibited varying coccolithophorid bloom stages from its early development to the post-bloom stages. The major HR patch, characterizing a post-stationary stage of the bloom, was located between 48°N and 49°N over the shelf along the continental margin. It was associated with moderate chlorophyll-a levels, never exceeding 1.0 µg L-1, dissolved phosphorus and silica depletion, and undersaturation of CO2 with respect to atmospheric equilibrium. Considered as the main drivers of the C cycle in this area, the CO2 fluxes associated with primary production, calcification and respiration were integrated in order to provide a comprehensive C budget in the area. [less ▲]

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See detailCell lysis during coccolithophorid blooms in the Northern Bay of Biscay
De Bodt, Caroline; Harlay, Jérôme ULg; Roevros, Nathalie et al

Poster (2009, January 25)

Phytoplankton cell lysis occurs in natural populations and is often associated with viral activity and zooplankton grazing. Cell lysis rates are expected to increase towards the decaying phase of the ... [more ▼]

Phytoplankton cell lysis occurs in natural populations and is often associated with viral activity and zooplankton grazing. Cell lysis rates are expected to increase towards the decaying phase of the bloom and may be associated with enhanced microbial activity and export of particulate matter to the seafloor. Their estimation was based on the measurement of esterase (a cytoplasmic enzyme) activity expected to appear in the water only after cell breakage. Field investigations, supported by remote sensing data, were conducted in recent years during late spring in the Northern Bay of Biscay, where frequent and recurrent coccolithophorid blooms are observed. Results on cell lysis rates determined in surface waters will be presented with relevant biogeochemical parameters (temperature, particulate organic and inorganic carbon, transparent exopolymer particles, nutrients, chlorophyll a) in order to investigate phytoplankton dynamics in relation to coccolithophorid development. The use of this parameter to characterize bloom termination, especially during coccolithophorid blooms will be discussed. [less ▲]

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See detailSynthesis of an universal linker to label oligonucleotides via Click Chemistry
Flagothier, Jessica ULg; Mercier, Frederic; Kaisin, Geoffroy ULg et al

Poster (2009, January 21)

For more than 3 decades, oligonucleotides have been used for therapies, imaging and diagnostics. They are known to hybridize specifically with RNA of a complementary sequence on tissue sections and more ... [more ▼]

For more than 3 decades, oligonucleotides have been used for therapies, imaging and diagnostics. They are known to hybridize specifically with RNA of a complementary sequence on tissue sections and more recently to block the expression of target mRNA when administered in vivo (1). Positron emission Tomography (PET) is a sensitive and non invasive imaging technique, and is the most advanced technology currently available for studying in vivo molecular interactions and therapeutic agents. It is a method of choice to assess the pharmacokinetics of new therapeutics agents such as modified oligonucleotides. Among positron-emitting nuclides, fluorine-18 (t1/2 = 109.8 min) appears to be the best candidate due to its favourable physical and nuclear properties. Several of the methods described in the literature to label oligonucleotides present a number of disadvantages (time of synthesis, low overall radiolabelling yield, non-universal). Due to the speed, selectiveness and the relatively mild experimentals conditions, “Click” chemistry seems a powerful technique. The most explored Click reaction is Huisgen 1,3 dipolar cycloaddition. In our case, this reaction occurs between an alkyne group presents on the oligonucleotide and an azide group on the 18F labelled prosthetic group. The originality of our strategy is the use of a universal linker diverted from the trans-4-hydroxy-proline directly connected to the oligonucleotide. This linker mimics a sugar of the oligonucleotide sequence and should improve their resistance to exonucleases. Synthesis of this compound will be presented. [less ▲]

Detailed reference viewed: 70 (3 ULg)
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See detailNouvelles relations entre scientifiques et communautés locales dans la gestion des aires protégées
Escobar Jimenez, Kelly ULg

Poster (2009, January 09)

L'exploration de nouvelles relations entre communautés locales et milieux scientifique se concentre sur: un processus: la prise de décisions sur les limites, les espèces et les communautés responsables ou ... [more ▼]

L'exploration de nouvelles relations entre communautés locales et milieux scientifique se concentre sur: un processus: la prise de décisions sur les limites, les espèces et les communautés responsables ou “bénéficiaires” des aires protégées en Amazonie Équatorienne; sur une autorité: les concepts techniques et scientifiques sur les caractéristiques et la gestion des aires protégées en AL, notamment en Amazonie Équatorienne; et sur des relations: la gestion des aires protégées constitue-t-elle un scénario de nouvelles relations entre scientifiques et communautés locales, vu les démarches participatives généralisées en Amérique latine ? [less ▲]

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See detailRecent threats on coastal ecosystems by new pollutants: a multiple trace element study
Richir, Jonathan ULg; Gobert, Sylvie ULg; Bouquegneau, Jean-Marie ULg

Poster (2009, January)

The Mediterranean Sea is an enclosed basin, highly submitted to anthropogenic pressures. Chemical pollution from coastal urban centres and industries, or carried by air and rivers, primarily affects its ... [more ▼]

The Mediterranean Sea is an enclosed basin, highly submitted to anthropogenic pressures. Chemical pollution from coastal urban centres and industries, or carried by air and rivers, primarily affects its coastal ecosystems. Pollution by trace elements is rapidly evolving further to the recent modifications of their production and industrial uses by men. As a result, certain trace elements can now be considered as new environmental pollutants. Appropriate bioindicators are useful tools for the early warning of marine pollution. We presently investigate the use of the purple sea urchin Paracentrotus lividus and the marine phanerogam Posidonia oceanica as bioindicators to monitor the Mediterranean coastal pollution by new trace pollutants (Be, V, Mo, Mn, PGEs, Ag, Al, As, Se, Sb and Bi). Classic trace metals (Cd, Cr, Cu, Zn, Ni, Sn, Pb, Co and Fe) are also studied. Organisms were seasonally collected in 2008 in a reference site and a polluted one, respectively Calvi bay (Corsica) and Marseille (France). Their tissular trace element concentrations were determined by ICP-MS. All the investigated trace elements were chosen for their potential toxic effects. [less ▲]

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See detailLes habitudes de sommeil chez les enfants de 2,5 à 6 ans
Philippe, Paule ULg; Scholl, Jean-Marc ULg; Zdanowicz, Nicolas

Poster (2009, January)

Introduction: les habitudes de sommeil chez les enfants sont éminemment variables suivant les enfants, les âges, les habitudes ou contraintes familiales. Elles sont d’autre part peu connues et peu ... [more ▼]

Introduction: les habitudes de sommeil chez les enfants sont éminemment variables suivant les enfants, les âges, les habitudes ou contraintes familiales. Elles sont d’autre part peu connues et peu investiguées en consultation. Mais peut-on relever des différences entre une population générale "normale" et une population prise en charge dans des consultations psychologiques ambulatoires? Méthode: un questionnaire concernant les habitudes de sommeil a été distribué à des parents d’enfants fréquentant l’enseignement ordinaire et à des parents d’enfants fréquentant des consultations psychologiques ambulatoires. 496 réponses (356 pour la population générale et 140 pour les enfants suivis en consultation) ont été recueillies et analysées. Des différences de distributions ont été mises en évidence entre les 2 groupes et des corrélations recherchées. Paramètres recherchés : - le nombre d’heures de sommeil par nuit en semaine et le week-end ; - le nombre d’enfants « couche-tôt » ou « couche-tard » ; - les caractéristiques de l’endormissement: l’enfant retarde la mise au lit, il a besoin d’une sucette/ d’un doudou/ d’un morceau de tissu/ d’un biberon/ de lumière ou noir complet/ d’une TV/ que la porte soit ouverte/ il manifeste un inconfort/ des peurs/ il s’endort seul dans sa chambre ou en présence d’un adulte avec éventuellement le besoin de tenir physiquement cet adulte/ durée moyenne de l’endormissement - l’endroit où dort l’enfant : dans sa chambre, avec un frère/ une sœur, dans la chambre des parents, dans une pièce de séjour commune … - les caractéristiques du temps de sommeil : sommeil agité, réveils nocturnes, cauchemars, cherche à rejoindre ses parents pendant la nuit Conclusions: les comportements liés au sommeil différencient spécifiquement le groupe des enfants recrutés dans les Services de Santé Mentale par rapport au groupe témoin. Dans notre pratique, une anamnèse détaillée dans ce domaine permet d’attirer l’attention sur une population fragile, à examiner plus attentivement et éventuellement à prendre en charge dès que possible. Une information et une aide pour les parents est à envisager très précocement; une information serait utile également pour les différents professionnels (puéricultrices, enseignants, éducateurs, médecins traitants...). [less ▲]

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See detailWeekly satellite sea surface temperature around Corsica, a DINEOF analysis of AVHRR data (1998), foreseeing comparison with interpolated and modelled fields.
Sirjacobs, Damien ULg; Lenartz, Fabian ULg; Troupin, Charles ULg et al

Poster (2009, January)

Providing wide coverage and high spatio-temporal resolution, SST satellite archives are valuable sources of information for sound understanding of the ocean dynamics, including validation of ... [more ▼]

Providing wide coverage and high spatio-temporal resolution, SST satellite archives are valuable sources of information for sound understanding of the ocean dynamics, including validation of hydrodynamical modelling studies. Yet original SST fields have also many gaps (clouds, retrieval problems), but they are known to exhibit strong spatial and temporal correlations for regions of similar dynamics. This is exploited by the parameter free statistical technique DINEOF (Data Interpolation with Empirical Orthogonal Functions) [Alvera-Azcárate et al. (2005) Ocean Modell.; Beckers et al. (2006) Ocean Sciences] to produce full weekly analysis of the variability of the sea surface temperature (SST) around Corsica and in the Ligurian Sea at weekly temporal resolution during the year 1998. A detection of outliers implemented in DINEOF analysis is tested for pointing out unusual or invalid SST data. This study is realised foreseeing a comparison of DINEOF weekly averaged reconstructed fields with those obtained by interpolating methods on the same dataset (Data Interpolating Variationnal Analysis and Optimal Interpolation schemes), and with outputs of an implementation of the GHER 3D model in this area. [less ▲]

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See detailEvidence for wastewater influence in a low impacted area throughout stable isotope analyses of the limpet Patella caerulea and epilithic biofilms
Vermeulen, Simon ULg; Lepoint, Gilles ULg; Gobert, Sylvie ULg

Poster (2009, January)

Eutrophication is considered to be one of the main threats to marine environments leading to changes in trophic status of ecosystems and alteration of biological diversity. Carbon and Nitrogen stable ... [more ▼]

Eutrophication is considered to be one of the main threats to marine environments leading to changes in trophic status of ecosystems and alteration of biological diversity. Carbon and Nitrogen stable isotopes analyses were performed on the limpet Patella caerulea and one of its food sources (epilithic biofilms) to assess their potential as early indicators of eutrophication. Samples were seasonally collected in 2005-2006 on five locations gradually exposed to urban sewage in the Calvi Bay and in the Marseilles harbour. Stable isotope signatures of Patella caerulea muscles exhibited steady site - specific values over seasons. In contrast to this time – integrated signal, wide variations in biofilm values show that either composition or isotopic ratios of food sources may vary greatly in time and space. Elevated δ15N values of limpets and biofilms, typical of wastewater influence but unrelated to nitrogen loads, indicate the biological availability of sewage-derived nitrogen in the Calvi Bay and the Marseilles harbour. A reference level of δ15N values is rapidly reached with increasing depth that indicates the limited vertical extent of pollution in the Calvi Bay. [less ▲]

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See detailFish farm impacts on Posidonia oceanica meadows: interest of the microbenthic loop.
Pete, Dorothée ULg; Velimirov, Branko; Bouquegneau, Jean-Marie ULg et al

Poster (2009, January)

Posidonia oceanica, the seagrass endemic to the Mediterranean Sea, is a valuable tool to assess the environmental quality in coastal zones. However, only few studies have attempted to use characteristics ... [more ▼]

Posidonia oceanica, the seagrass endemic to the Mediterranean Sea, is a valuable tool to assess the environmental quality in coastal zones. However, only few studies have attempted to use characteristics of its sediment compartment as an indicator of environmental perturbations. In this study, the impact of a fish farm on the microbenthic loop (organic matter, bacteria, microphytobenthos and meiofauna) of P. oceanica meadows will be described. Samples were taken under an aquaculture situated in Calvi Bay (Corsica, France) at a depth of 22 m, in March and June 2008. The control site was the meadow situated in front of the research station STARESO (Calvi Bay, Corsica, France), sampled at the same periods and depth. Results concerning bacteria, microphytobenthos and organic matter will be presented here. For both seasons, differences between sites exist. For example, biomasses of organic matter, microphytobenthos and bacteria are higher in the fish farm than in the control site, indicating that the microbenthic loop has potential to be a good early indicator of pollution in this sea. [less ▲]

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See detailChemical and enzymatical modifications of sugar derived from lignocellulose
Richard, Gaetan ULg; Laurent, Pascal ULg; Nott, Katherine ULg et al

Poster (2009, January)

Actually, biorefinery is increasingly considered as a promising alternative to petroleum chemistry, since it aims at not only the replacement of fossil energy but also the development of chemicals from ... [more ▼]

Actually, biorefinery is increasingly considered as a promising alternative to petroleum chemistry, since it aims at not only the replacement of fossil energy but also the development of chemicals from biomass, with applications such as detergents, phytopharmaceutics, solvents, plastics, etc. The valorisation of carbohydrates from renewable raw materials is currently the subject of numerous researches. In this context, the synthesis of new surfactants derived from the sugars issued from the lignocellulose hydrolysis was undertaken by chemical or enzymatic routes. In this poster, the examples of glucose, cellobiose and uronic acids will be discussed. Whatever the way used, the reaction conditions (use of a catalyst, protection/deprotection steps, type of solvent, presence of co-solvent, reactant concentrations, etc) were optimized to yield a panel of carbohydrate derivatives (some examples of the structures obtained are given above). These differ by the nature of the alkyl chain (in length and in degree of saturation), the type of chemical bond (amide, ester, thioester, acetal), and the position of substitution. The impact of these differences on the techno-functional properties of these modified sugars will be evaluated. [less ▲]

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See detailLight transmission imaging as a useful tool to decrypt root water uptake
Lobet, Guillaume ULg; Javaux, M.; Pagès, L. et al

Poster (2009)

Detailed reference viewed: 8 (2 ULg)
Peer Reviewed
See detailEstimation of biochemical network parameter distributions in cell populations
Hasenauer, J; Waldherr, S; Schliemann, Monica ULg et al

Poster (2009)

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See detailAn analysis of the random error affecting CO2 fluxes measured by eddy covariance.
Laffineur, Quentin ULg; Heinesch, Bernard ULg; Aubinet, Marc ULg

Poster (2009)

This study focuses on random errors associated with eddy covariance flux measurements. This error is heteroscedastic, increases linearly with the flux magnitude and the error on CO2 flux decreases with ... [more ▼]

This study focuses on random errors associated with eddy covariance flux measurements. This error is heteroscedastic, increases linearly with the flux magnitude and the error on CO2 flux decreases with increasing wind speed. As random errors accumulate in quadrature, they are less critical than systematic errors as far as flux sums are concerned. On the other hand it may affect significantly half-hour data and pose problem for modelling or analysis of flux response to environmental parameters. It is therefore useful to characterize the site and the specific conditions under which the random error is the most important. The random error on CO2 flux was computed at two sites, one cropland and one forested site, by using the daily differencing approach (DDA, Hollinger and Richardson 2005). Relationships with flux and wind speed were compared between different periods (day vs. night, growing season vs. rest of the year) and for different flux computation methods. First, an increase of random error with decreasing wind speed was observed at low speed. This effect was not observed during the rest period at the cropland site and disappears when a high-pass filtering is applied to the data. It may be explained by two processes: on one hand, the below canopy air layer is less efficiently mixed which can create large flux variations when CO2 sources and sinks are separated. On the other hand, mesoscale motions may exceed small-scale turbulence at low wind speed. At similar wind speeds, the random error was lower at the cropland than at the forested site, which can be due to either process: indeed, at the cropland site, the distance between CO2 sources and sinks is smaller which reduce the low mixing effect but the site is also more flat and homogeneous which reduce the impact of mesoscale movements. The possibility of mesoscale movement impact is supported by the fact that the effect disappears when applying a high pass filtering. The random error was also found sensitive to the computational method: in particular it is larger when the flux is computed using the block average rather than the running mean, it increases when storage is taken into account and decreases when data are filtered by applying stationarity screening or u* filtering. [less ▲]

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See detailBiomimetic approaches to understand how mycosubtilin, an antifungal lipopeptide, can interact with cytoplasmic membranes
Nasir, Mehmet Nail ULg; Kouzayha, Achraf; Besson, Françoise

Poster (2009)

Mycosubtilin is a natural cyclic lipopeptide characterized by its strong antifungal activities. It has been demonstrated that the cytoplasmic membranes of the sensitive cells are the target of this ... [more ▼]

Mycosubtilin is a natural cyclic lipopeptide characterized by its strong antifungal activities. It has been demonstrated that the cytoplasmic membranes of the sensitive cells are the target of this antifungal lipopeptide. In spite of the fact that some properties of mycosubtilin have been highlighted, the molecular mechanism of its biological action remains partially understood. In view of this, we investigated the interactions between mycosubtilin and cytoplasmic membranes by using biomimetic systems such as lipid monolayers at the air-water interface and lipid multilayers. These interactions were examined by different methods (pressure/area isotherms, kinetic measurements of the interfacial adsorption, Brewster angle microscopy, infrared and NMR spectroscopies). We showed that mycosubtilin does not interact strongly with the C=O ester residues of phospholipids in multilayers, while it modifies the transition temperature of the alkyl chains. It was also demonstrated that these interactions depend on the phospholipid phase. Varying the lipid composition of monolayers allowed us to demonstrate an original behavior of mycosubtilin in the presence of sterol. This suggests a mycosubtilin-sterol affinity. [less ▲]

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See detailAn analysis of the random error affecting CO2 fluxes measured by eddy covariance
Laffineur, Quentin ULg; Heinesch, Bernard ULg; Aubinet, Marc ULg

Poster (2009)

This study focuses on random errors associated with eddy covariance flux measurements. This error is heteroscedastic, increases linearly with the flux magnitude and the error on CO2 flux decreases with ... [more ▼]

This study focuses on random errors associated with eddy covariance flux measurements. This error is heteroscedastic, increases linearly with the flux magnitude and the error on CO2 flux decreases with increasing wind speed. As random errors accumulate in quadrature, they are less critical than systematic errors as far as flux sums are concerned. On the other hand it may affect significantly half-hour data and pose problem for modelling or analysis of flux response to environmental parameters. It is therefore useful to characterize the site and the specific conditions under which the random error is the most important. The random error on CO2 flux was computed at two sites, one cropland and one forested site, by using the daily differencing approach (DDA, Hollinger and Richardson 2005). Relationships with flux and wind speed were compared between different periods (day vs. night, growing season vs. rest of the year) and for different flux computation methods. First, an increase of random error with decreasing wind speed was observed at low speed. This effect was not observed during the rest period at the cropland site and disappears when a high-pass filtering is applied to the data. It may be explained by two processes: on one hand, the below canopy air layer is less efficiently mixed which can create large flux variations when CO2 sources and sinks are separated. On the other hand, mesoscale motions may exceed small-scale turbulence at low wind speed. At similar wind speeds, the random error was lower at the cropland than at the forested site, which can be due to either process: indeed, at the cropland site, the distance between CO2 sources and sinks is smaller which reduce the low mixing effect but the site is also more flat and homogeneous which reduce the impact of mesoscale movements. The possibility of mesoscale movement impact is supported by the fact that the effect disappears when applying a high pass filtering. The random error was also found sensitive to the computational method: in particular it is larger when the flux is computed using the block average rather than the running mean, it increases when storage is taken into account and decreases when data are filtered by applying stationarity screening or u* filtering. [less ▲]

Detailed reference viewed: 30 (7 ULg)
Peer Reviewed
See detailMolecular phylogeny of symbiotic pearlfishes
Lanterbcq, D; Parmentier, Eric ULg; Todesco, Maïté et al

Poster (2009)

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See detailNeutrino masses in R-parity violating SUSY
Vicente, Avelino ULg

Poster (2009)

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See detailFamiliar person recognition: do we remember more episodic memories from faces than from names?
Barsics, Catherine ULg; Brédart, Serge ULg

Poster (2009)

This study was aimed at investigating whether the recognition of familiar faces is more likely to be associated with an experience of Remembering than the recognition of familiar names. Using the Remember ... [more ▼]

This study was aimed at investigating whether the recognition of familiar faces is more likely to be associated with an experience of Remembering than the recognition of familiar names. Using the Remember/Know paradigm the proportions of episodic memories recalled following the recognition of famous faces and names (Conditions) were assessed. Presented faces and names were previously judged by an independent group of participants as eliciting an equivalent level of familiarity. Nevertheless significant differences between the two conditions appeared in hit and false alarm rates. However, present results showed no significant difference in the recollection of personal memories (Remember responses conditionalized on the hits), following familiar faces compared with familiar names recognition. This finding contrasts with recent accounts assuming that faces are more prone to yield episodic memories than other cues to person identity. These results and their implications for current Interactive Activation and Competition person recognition models are discussed. [less ▲]

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See detailYlang-ylang (Cananga odorata (Lam.) Hook. & Thoms. var. genuina) essential oils from Comoros Islands: characterization and variability
Benini, Céline ULg; Wathelet, Jean-Paul ULg; du Jardin, Patrick ULg et al

Poster (2009)

The Union of the Comoros is the world’s biggest producer of ylang-ylang essential oils. Comorian ylang-ylang also provides the most valuable essential oil that can be found on international market. This ... [more ▼]

The Union of the Comoros is the world’s biggest producer of ylang-ylang essential oils. Comorian ylang-ylang also provides the most valuable essential oil that can be found on international market. This product represents a high percentage of Comoros’ annual currency. Ylang-ylang essential oil is obtained by fractionned hydrodistillation or steam distillation of Cananga odorata fresh flowers. This oil is commercialized in five different quality grades (extra S; extra; I; II; III) which possess their own physicochemical properties. [less ▲]

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See detailCentre de Ressources Autisme Liège
Philippe, Paule ULg; Jacques, Jessica ULg

Poster (2009)

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See detailModelling and parameter estimation for heterogeneous cell populations
Waldherr, S; Hasenauer, J; Schliemann, Monica ULg et al

Poster (2009)

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See detailVOC and ozone fluxes from a pine forest in the north of Belgium
Eerdekens, Guenther; Gielen, Bart; Neirynck, J. et al

Poster (2009)

Plants release large amounts of carbon as Volatile Organic Compounds (VOCs) into the atmosphere. These VOCs play an important role in the chemistry of the troposphere as they can be involved in the ... [more ▼]

Plants release large amounts of carbon as Volatile Organic Compounds (VOCs) into the atmosphere. These VOCs play an important role in the chemistry of the troposphere as they can be involved in the mechanisms of ozone and aerosol formation. The key mechanisms underneath biogenic VOC emissions are still not well understood, leading to large uncertainties in BVOC inventories on global and regional scales. Measurements of VOCs, ozone and micro-meteorology are conducted at the ‘De inslag’, a 80-year old mixed pine–oak forest located in the Campine region near Antwerp, Belgium. The forest site is a level-II plot of the European Programme of Intensive Monitoring Forest Ecosystems and is part of the Carboeuro and Nitroeurope-flux research network. The site is equipped with a flux tower that reaches above the 23m canopy. A Proton Transfer Reaction Mass Spectrometer and a Fast Ozone analyser allow determining VOC and ozone fluxes by Eddy Covariance. An analytic footprint model is used to exclude non-forest fluxes. In this study, we will test the accuracy of this footprint model with anthropogenic tracers (benzene and toluene). [less ▲]

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See detailLancement d’un programme d’amélioration génétique de Jatropha curcas L. au Sénégal
Terren, Marieke ULg; Saverys, S.; Jacquet de Haverskercke, P et al

Poster (2009)

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See detailThe Europlanet national nodes network
Fouchet, T.; Heward, A.; Chatzchristou, E. T. et al

Poster (2009)

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See detailHydroxyl detection on Venus and Earth and implications for ozone
Migliorini; Piccioni, G.; Cardesin-Molino, A. et al

Poster (2009)

We present a comparison between hydroxyl night side infrared emissions on Earth and Venus. The vertical brightness distributions of the OH emissions are shown for the two planets and excitation processes ... [more ▼]

We present a comparison between hydroxyl night side infrared emissions on Earth and Venus. The vertical brightness distributions of the OH emissions are shown for the two planets and excitation processes are discussed. [less ▲]

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See detailSpecies delimitation and phylogeography of an African tropical tree species complex
Duminil, J.; Heuertz, M.; Bourland, Nils ULg et al

Poster (2009)

Detailed reference viewed: 65 (9 ULg)
See detailWave-particle duality in a two atom interferometer
Schilling, U.; Thiel, C.; Bastin, Thierry ULg et al

Poster (2009)

Detailed reference viewed: 11 (1 ULg)
See detailImpact de l’anthropisation sur la composition paysagère de l’Ile Mbiye en R.D. Congo.
Bamba, I; Shimba, N; Iyongo, L et al

Poster (2009)

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See detailAn in situ NMR analysis of the formation of P- and SiO2-doped TiO2 xerogels
Bodson, Céline ULg; Lambert, Stéphanie ULg; Cattoën, Xavier et al

Poster (2009)

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See detailInnate lymphocytes in human papillomavirus (HPV)-associated cervical cancers
Renoux, V; Bisig, B; Thiry, Marc ULg et al

Poster (2009)

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See detailStudy of the usefulness of the data of Bacillus cereus outbreaks in Belgium (2005-2008) for a dose-response modelling purpose
Durenne, Bastien ULg; Denayer, Sarah; Botteldoorn, Nadine et al

Poster (2009)

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See detailMCF-7/BOS cells membrane proteome: comparison of two isolation methods using mass spectrometry
Bertrand, Virginie ULg; Massart, Anne-Cécile ULg; De Pauw-Gillet, Marie-Claire ULg et al

Poster (2009)

Membrane proteins (MP) play an important role in biological processes. Isolation and quantification of these MP using classical techniques is often limited due to their poor solubility and relatively low ... [more ▼]

Membrane proteins (MP) play an important role in biological processes. Isolation and quantification of these MP using classical techniques is often limited due to their poor solubility and relatively low abundance. These membrane proteins enclosed markers which could be potential therapeutic targets. These potential therapeutic targets have to be accessible to antibodies and need to be presented in the plasmic membrane. Assays were conducted on MCF-7 / BOS cell line, immortal and easier to cultivate. The goal of this work is to obtain an enriched membrane fraction to facilitate the analysis of the sample and to simplify the complex proteins mixture. To isolate transmembrane proteins, we compared two methods. The first one used different extraction cycles characterized by different buffers to isolate membrane proteins. The second method labelled accessible extracellular domains at the surface of MCF-7 cells with biotin prior to differential centrifugation. The obtained enriched membrane proteome was digested with trypsin and/or Lysyl Endopeptidase. Obtained peptides were separated by 2D-HPLC chromatography and on-line analysed ion trap mass spectrometer, the Esquire HCT. [less ▲]

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See detailVascularisation of the equine menisci
De Busscher, V.; Maitre, D.; Busoni, Valeria ULg et al

Poster (2009)

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See detailEtude exploratoire des changements émotionnels et comportementaux chez des patients ayant la sclérose en plaques
Belhadj, Soumaya; DELRUE, Gaël ULg; VOKAER, Mathieu et al

Poster (2009)

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See detailRegulation of microRNAs expression by the antiangiogenic factor 16K hPRL
Halkein, Julie ULg; Malvaux, Ludovic; Nguyen, Ngoc-Quynh-Nhu ULg et al

Poster (2009)

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See detailEvaluation de la diversité de la végétation spontanée de l’écosystème urbain de Bujumbura.
Bigirimana, J; Bogaert, Jan ULg; De Cannière, C et al

Poster (2009)

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See detailModelling and Simulation of Rat Swimming in a Water Maze Experiment
Fey, D.; Commins, Séan; Bullinger, Eric ULg

Poster (2009)

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See detailProduction of four amyloidogenic variants of human lysozyme as inclusion bodies in Escherichia coli
Dumont, Janice ULg; Menzer, Linda ULg; Scarafone, Natacha ULg et al

Poster (2009)

Six variants of human lysozyme (I56T, F57I, W64R, D67H, F57I/T70N and W112R/T70N) are associated with a hereditary non-neuropathic systemic amyloidosis. This disease involved an extra cellular deposition ... [more ▼]

Six variants of human lysozyme (I56T, F57I, W64R, D67H, F57I/T70N and W112R/T70N) are associated with a hereditary non-neuropathic systemic amyloidosis. This disease involved an extra cellular deposition of amyloid fibrils made of lysozyme variants in a wide range of organs such as liver, spleen and kidneys [1]. The characterisation at the molecular level of two variants, I56T and D67H, has shown that these mutations reduce the stability and more particularly the global cooperativity of the protein. Consequently, under physiologically relevant conditions, these variants can transiently populate a partially unfolded state in which the beta-domain and the C-helix are cooperatively unfolded while the rest of the protein remains native like [1]. The formation of intermolecular interactions between the regions that are unfolded in this intermediate state is likely to be a fundamental trigger of the aggregation process that ultimately leads to the formation and deposition of fibrils in tissues. In order to study the effects of the other amyloidogenic mutations on the properties of lysozyme and thus to get more insight in the mechanism of amyloid formation, it is necessary to produce them in large quantities. The D67H, I56T and F57I variants are currently produced in Aspergillus niger; the expression in this organism is, however, time consuming and the yield is very low. The attempts to use alternative systems such as Pichia pastoris [2], Saccharomyces cerevisiae, and Arabidopsis thaliana have not been conclusive so far. In this work, we have produced the four single-point lysozyme variants as inclusion bodies in Escherichia coli and explored the possibility to refold them. [1] Dumoulin & al., (2006) Acc. Chem. Res., 39, 603 - 610 [2] Kumita & al., (2006) FEBS J., 273, 711-720 [less ▲]

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See detailReal-time spatial analysis of root water uptake in rhizotrons
Lobet, Guillaume ULg; Javaux, M.; Pages, L. et al

Poster (2009)

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See detailIn vitro fibre fermentation characteristics of specialty ingredients with varying NSP levels
Jha, Rajesh; Bindelle, Jérôme ULg; Rossnagel, Brian et al

Poster (2009)

Detailed reference viewed: 18 (1 ULg)
See detailFalse memories and surprise: Round #3
Willems, Sylvie ULg; Dehon, Hedwige ULg

Poster (2009)

Detailed reference viewed: 6 (2 ULg)
See detailMassive stars and emission-line stars with GAIA
Blomme, Ronny; Frémat, Y.; Lobel, Alex et al

Poster (2009)

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See detail4th International Symposium on Chemosynthesis-based Ecosystems
Ponsard, J; Cambon-Bonavita, M-A; Lepoint, G et al

Poster (2009)

Detailed reference viewed: 17 (1 ULg)
See detailMultipartite entanglement criterion from uncertainty relations
Gillet, Jérémie ULg; Bastin, Thierry ULg; Agarwal, G. S.

Poster (2009)

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See detailSensitivity analysis of a 3D diffusive drying model
Janas, Sébastien ULg; Deroanne Claude; Bera, François ULg

Poster (2009)

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See detailInteraction between the bioactive lipopeptide fengycin and lipid membrane
Deleu, Magali ULg; Campbell, Richard; Hellsing, Maya et al

Poster (2009)

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See detailAnalysis of lateral mobility of channels at different spatial and time scales (Ardenne massif, Belgium)
Houbrechts, Geoffrey ULg; Van Campenhout, Jean ULg; Hallot, Eric ULg et al

Poster (2009)

Lateral mobility of Ardenne rivers has been studied at different scales using three complementary methods. We firstly compared the layout of channels on topographic maps (since the 18th century) and ... [more ▼]

Lateral mobility of Ardenne rivers has been studied at different scales using three complementary methods. We firstly compared the layout of channels on topographic maps (since the 18th century) and aerial pictures. Given that these documents have different scales and projection systems, they were transformed into a common referencing system. This method allowed us to study the lateral shifting of channels, however, as the mobility of Ardenne rivers is relatively low, the errors of geometric rectifications are often more important than lateral displacements. Therefore, to visualize these deformations, georeferenced documents were overlaid with a regular grid of points. We represented the imprecision vector based on x and y residual components for each point. These vectors show the direction of the deformation and its amplitude. Large quantities of iron slag are present in the sediments of Ardenne rivers. These waste products come from hundreds of ironworks built close to rivers since the 14th century. Analyses of slag concentrations in alluvial deposits allowed us to delimitate the sectors of floodplains eroded by rivers during the last centuries. In these sectors, slag elements are present at the contact with the gravel sheet. Finally, we analysed the topography of floodplains from a DEM-LIDAR. This digital elevation model has been established by the Walloon Region for the cartography of flood risk in floodplains. It presents a Z mean error of only 15 cm and a X-Y resolution of 1 m. In order to reveal paleochannels and topographic alluvial units, we subtracted a surface, corresponding to the longitudinal water surface slope, extracted from the DEM. By using this method, we are able to obtain the relative height of any point of the floodplain with regard to the water surface, projected perpendicularly to the layout, on this point. This procedure reveals paleochannels even if they are almost infilled and allows us to delimitate, for several kilometres, alluvial units, which have been formed at different periods. [less ▲]

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See detailMerovingian pottery in the Mosan Valley: diffusion and consumption
Van Wersch, Line ULg; Coquinot, Yvan; Mathis, François ULg et al

Poster (2009)

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See detailResistance of pearlfishes to saponins
Maïté, Todesco; Parmentier, Eric ULg; Eeckhaut, Igor

Poster (2009)

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See detailQuantum imaging using single photon sources
von Zanthier, J.; Thiel, C.; Bastin, Thierry ULg et al

Poster (2009)

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See detailGeneration of total angular momentum eigenstates in remote qubits
Maser, A.; Schilling, U.; Bastin, Thierry ULg et al

Poster (2009)

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See detailGeneration of total angular momentum eigenstates in remote qubits
Maser, A.; Schilling, U.; Bastin, Thierry ULg et al

Poster (2009)

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See detailBiodiversité végétale et pressions anthropiques dans la forêt marécageuse de Lokoli (Bénin).
Mama, A; Adomou, A; Dan, C et al

Poster (2009)

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See detailHot stars survey with the GAIA space mission
Lobel, A.; Liu, C.; Frémat, Y. et al

Poster (2009)

Detailed reference viewed: 29 (11 ULg)
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See detailPast and future events specificity in bipolar disorders
Boulanger, Marie ULg; Lejeune, Aurélie; Blairy, Sylvie ULg

Poster (2009)

Previous research has shown that the individuals suffering from emotional disorders have specificity of autobiographical memory (AM) deficits. This difficulty to remember specific personal past events ... [more ▼]

Previous research has shown that the individuals suffering from emotional disorders have specificity of autobiographical memory (AM) deficits. This difficulty to remember specific personal past events seems related to difficulty to project specific oneself into the future (D’Argembeau, Raffard & Van der Linden, 2008). The aim of this study was investigated these impairments in population with bipolar disorders (BD). Participants (19 patients with bipolar disorders and 17 healthy subjects) completed validated French versions (Neumann & Philippot, 2006) of the AMT Williams & Broadbent (1986). Participants were instructed to generate specific past and future memories in response to cues words. For past events, the analyses revealed a significant group by memory interaction (F(2,68) = 4.0 ; p=.023) which indicates that the patients with BD recollected less specific events and more overgeneral events than controls. In the same way, for the future events task, a significant group by memory interaction emerged (F(2,68) = 7.85 ; p<.001) which indicates that the patients with BD were less specific and yielded more overgeneral memories than the control group. Thereby the results are consistent with previous studies that have examined autobiographical memory specificity in patients with BD (Scott et al., 2000; Mansell & Lam, 2004). However, to ours knowledges, the present study is the first to investigate specificity of AM and the abilities to generate specific events for future in patients with bipolar disorders. [less ▲]

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See detailNicotine restores endothelial dysfunction caused by excess sFLT1 and sEng in in vitro model pf preeclamptic vascular endothelium
Mimura, Kazuya; Tomimatsu, Takuji; Sharentuya, Namuxila et al

Poster (2009)

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See detailEcological modeling and paedomorphosis: a study case in Montenegrin newts
Denoël, Mathieu ULg; Ficetola, Gentile; Cirovic, Rusa et al

Poster (2009)

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See detailImpact de l’action anthropique sur la diversité floristique et structurale de la forêt de Rumonge au Burundi
Hakizimana, P; Lejoly, J; Habonimana, B et al

Poster (2009)

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See detailEmission line stars in the Milky Way with the GAIA space mission
Martayan, C.; Frémat, Y.; Blomme, R. et al

Poster (2009)

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See detailEffects of crops on solute transport in undisturbed soil
Garré, Sarah ULg; Javaux, Mathieu; Vanderborght, Jan

Poster (2009)

Models predicting movement of surface applied chemicals incorporate knowledge on the water velocity field and moisture content distribution. Although the influence of root water uptake on solute transport ... [more ▼]

Models predicting movement of surface applied chemicals incorporate knowledge on the water velocity field and moisture content distribution. Although the influence of root water uptake on solute transport is commonly recognized as important, it has been studied sparsely. Yet, plants may take up a large part of the infiltrating water, thereby influencing the water flow pattern in the soil and concurrently solute transport processes. For this reason, experiments are required to investigate the relationship between plant root water uptake and flow field variability. The role of root water uptake on solute transport will be elucidated in two undisturbed soil columns. During three consecutive experiments, the influence of growing barley on tracer movement through a silty soil in two lysimeters will be followed. At the first stage, an inert tracer is put on the two bare lysimeters and leached with constant irrigation. As steady-state flow can be assumed, it is possible to follow the tracer movement in the column by ERT and to identify regions of preferential flow and solute transport parameters. During the second experiment, the tracer will be applied to mature barley grown in the lysimeters. Combining the information about the water content obtained with TDR with the relation between water content, soil solution salinity and bulk electrical conductivity, the soil solution salinity distribution can be derived from images of bulk electrical conductivity obtained with ERT. Root growth will be monitored using a minirhizotron. By comparing the transport parameters obtained after these two experiments, the effect of root water on the transport process can be quantified. When the columns are washed out and the barley is harvested, the third phase will be carried out under the same steady state flow conditions as in the first experiment to investigate the effect of dead roots on soil structure. [less ▲]

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