Prevalence and screening of burnout among Belgian population

Poster (2011, May 26)

The aim of the study was to estimate the prevalence of burnout among Belgian workers through the identification of burnout cases within the practices of general practitioners (GP) and the health ... [more ▼]

The aim of the study was to estimate the prevalence of burnout among Belgian workers through the identification of burnout cases within the practices of general practitioners (GP) and the health surveillance carried out by occupational health physicians (OP) .The prevalence may be estimated at about 0,8 % of the Belgian population; this figure is similar among workers consulting GP and OP. [less ▲]

Multiqubit symmetric states with a high geometric entanglement

Poster (2011, May 25)

We propose a detailed study of the geometric entanglement properties of pure symmetric N-qubit states, focusing more particularly on the identification of symmetric states with a high geometric ... [more ▼]

We propose a detailed study of the geometric entanglement properties of pure symmetric N-qubit states, focusing more particularly on the identification of symmetric states with a high geometric entanglement and how their entanglement behaves asymptotically for large N. We show that much higher geometric entanglement with improved asymptotical behavior can be obtained in comparison with the highly entangled balanced Dicke states studied previously. We also derive an upper bound for the geometric measure of entanglement of symmetric states. The connection with the quantumness of a state is discussed. [less ▲]

Predominant effects of host plant species on Aphis gossypii aphid and Episyrphus balteatus hoverfly in a tritrophic approach

Poster (2011, May 24)

The aphid Aphis gossypii Glover (Homoptera: Aphididae) is known as worldwide important pest. It causes serious injuries to crops, but is also able to feed on various cultivated and wild plants. Some ... [more ▼]

The aphid Aphis gossypii Glover (Homoptera: Aphididae) is known as worldwide important pest. It causes serious injuries to crops, but is also able to feed on various cultivated and wild plants. Some programs are developped to control this aphid. In many studies , hoverfy Episyrphus balteatus De Geer (Diptera : Syrphidae) is used as an efficient and aphid specific predator in biological control systems. In this work, we study cotton aphid choice plant discrimination, the effect of host plants on its developpment(fecondity and mortality), and the E.balteatus foraging and oviposition behavior according aphid host plants. Biologic parameters were observed using various plant combinations. E.balteatus behavioral observations were conducted using the Noldus Observer v.5.0. A.gossypii makes discriminant choice of his hosts, with better preference on Cucurbita pepo L. (Cucurbitaceae) and Capsicum annuum L. (Solanaceae). Dacryodes edulis (G. Don) H.J. Lam. (Burseraceae) and Vicia faba L. (Fabaceae) are the midle choice while Hibiscus sabdariffa L. (Malvaceae) is less chosen. A.gossypii develops easily on C.pepo, and weakly on C.anuum, H.sabdariffa,and V.faba. D. edulis induces very high mortality to A.gossypii. According to E. balteatus behavior, A. gossypii is more attractive when infesting C .pepo and V.faba, less on H. sabdariffa. While non infested , the hoverfly more attractive plant is V.faba. Our results highlited the importance of interactions between aphids and their host plants and the prey-host influence on a specific aphid predatory hoverfy. Suitable ways in correlation with this work are to investigated to complete this study and perform aphids biological control. [less ▲]

Screening Elisa method to assess in vitro efficacy of new agents based on Lactoperoxydase system against phytopathogens

Poster (2011, May 24)

The lactoperoxydasesystem (LPS) is a natural biological protection system in human saliva, milk and tears. Lactoperoxydase catalyzes the oxidation of iodide (I-) and thiocyanate (SCN-) in presence of ... [more ▼]

The lactoperoxydasesystem (LPS) is a natural biological protection system in human saliva, milk and tears. Lactoperoxydase catalyzes the oxidation of iodide (I-) and thiocyanate (SCN-) in presence of hydrogen peroxide in hypoiodite (OI-) and hypothiocyanite (OSCN-) ions. Both ions have inhibitory action against pathogenic bacteria, fungi and viruses. Until now, the ions OI- and OSCN- applied separately from the LPS were not tested against plant pathogens. Seventeen KI/KSCN/H2O2 ratios with 3 dilutions for each one were tested against Botrytiscinerea. Results showed that the ions OI- and OSCN- gives a better % of inhibition with: -high concentration of KI+KSCN, -a ratio of KI/KSCN of 4.5 and -a ratioof (KI+KSCN)/H2O2 near 1. Increased dilution combined with lower KI+KSCN concentration reduced the efficacy of the ions. From the screening against B.cinerea, 4 ratios of KI+KSCN were selected and tested against 6 other phytopathogens. Results showed that the OI- and OSCN- ions give 87 and 100% inhibition against Penicillium expansum and Verticillium dahlia respectively. The inhibitory activity of the ions solution was ranged between 70 and 79% regarding Fusarium avenaceum, Phytophthora infestans and Colletotrichum lindemuthanium. The ions OI- and OSCN- showed an insufficient inhibitory activity against Septoria tritici. The screening method highlighted that high KI/KSCN ratios and low dilution were more efficient against phytopathogens. The efficient ratios will be further evaluated in vivo. [less ▲]

Stand structure of mosquitoes (Diptera: Culicidae) in farms and establishment of a new potential vector of West Nile Virus for Belgium

Poster (2011, May 24)

Many Diptera, spread across the globe are likely to play a role in the transmission of various human and animal diseases. Mosquitoes in particular, give rise to various countries on research increasingly ... [more ▼]

Many Diptera, spread across the globe are likely to play a role in the transmission of various human and animal diseases. Mosquitoes in particular, give rise to various countries on research increasingly expanded and deepened. To better understand the structure of the Culicidae at cattle farms in Belgium and identify habitats favorable to the development of each species, a taxonomic inventory was conducted in 2008 and 2009 in ten different sites. They fall into five natural regions: Condroz, Ardenne, Fagne-Famenne, Lorraine and Compine. The collection of mosquitoes is based on sampling of larvae in 13 biotopes such as water troughs, tires, abandoned utensils and temporary puddles or not. The results of the morphotaxonomic study of the mosquitoes collected in the different study sites show the presence of five species of Culicidae divided into three genera, Anopheles, Culex and Culiseta. Of the 1843 individuals examined in 2009, Culex pipiens represents 79.98% of the total harvest. A new species is reported for Belgium, Culex modestus Ficalbi, 1890. This species is one of the most important from an epidemiological and medical-veterinary entomology, given its role in the transmission of West Nile and myxomatosis viruses. [less ▲]

Activity-Flexibility and Stability Relationships as revealed by multiple mutants of a psychrophilic alpha-Amylase

Poster (2011, May 23)

Permanently cold environments, like polar regions, have been colonized by a great variety of psychrophilic organisms producing enzymes adapted to function efficiently at low temperatures. We have ... [more ▼]

Permanently cold environments, like polar regions, have been colonized by a great variety of psychrophilic organisms producing enzymes adapted to function efficiently at low temperatures. We have investigated the role of weak interactions in thermal adaptation of proteins by site-directed mutagenesis of the psychrophilc alpha-amylase (AHA) from the Antarctic bacterium Pseudoalteromonas haloplanktis. Two stabilized multiple-mutants (Mut5 and Mut5CC) have been constructed. The single mutations were selected by comparison of the presence of weak interactions in a mesophilic homolog from pig pancreas, PPA. The three enzymes AHA, Mut5 and Mut5CC have been analyzed by differential scanning calorimetry, thermal and chemical denaturation. The flexibility has been studied by acrylamide-induced fluorescence quenching. In order to investigate the kinetic origin of the gain in stability, the kinetics of unfolding and refolding in GdmCl have been monitored at 15°C. The newly introduced weak interactions stabilized the mutants, protected them against heat and chemical unfolding and also induced an effective loss of flexibility. In addition, the two multiple-mutants exhibit an increased optimum temperature for activity. The first results of kinetic studies show a similar refolding phase but differences between the three amylases in the unfolding phase. These results unambiguously support the capital role of weak interactions in the balance between activity, flexibility and stability and provide a better knowledge of the adaptation of enzymes to cold temperatures. [less ▲]

Phenotype Classification of Zebrafish Embryos by Supervised Learning

Poster (2011, May 20)

dentification of SIP1-modulated genes during the epithelial-to-mesenchymal transition and interactions with KLF factors in EMT control

Poster (2011, May 19)

La guerre à Gaza (2009): état d'insécurité après la redéfinition des frontières du conflit israélo-arabe?

Poster (2011, May 17)

Près de deux ans après la guerre à Gaza et l’opération israélienne « Plomb durci » (hiver 2008-2009), il est riche d’enseignements de tirer le bilan de cet événement ayant des répercussions locales ... [more ▼]

Près de deux ans après la guerre à Gaza et l’opération israélienne « Plomb durci » (hiver 2008-2009), il est riche d’enseignements de tirer le bilan de cet événement ayant des répercussions locales, régionales et internationales. La présente communication propose de donner les résultats d’une recherche menée pendant plus d’un an sur les conséquences de la guerre à Gaza (2009) à un niveau local (relation conflictuelle entre Israël, l’autorité palestinienne et le Hamas), et aux niveaux régional et international. La question de la frontière « virtuelle » entre Israël, ses voisins moyen-orientaux et ses partenaires internationaux est donc au centre de notre recherche. Cette communication se propose de livrer une vision originale de l’implication des relations internationales et de l’État dans la résolution d’un conflit, et de démontrer la rémanence d’un conflit dépassant les seules frontières de la Palestine et d’Israël. Pour ce faire, nous posons deux éléments essentiels dans la redéfinition des frontières du conflit : d’une part, l’opposition politique intra-palestinienne (autorité palestinienne vs. Hamas) et, d’autre part, les jeux de recomposition régionale autour du Hamas en tant que nouvel interlocuteur ou en tant qu’enjeu régional contre l'Etat israélien. Partant, trois axes de recherche sont privilégiés : le dépassement du conflit israélo-palestinien, la redéfinition des acteurs et enjeux régionaux et l’implication nouvelle d’acteurs étatiques hors de la région moyen-orientale. Le tout réside dans un état d’insécurité constant pour la région et pour l’État israélien au regard des enjeux et des recompositions régionales. La première approche nous permet de dépasser la seule lecture israélo-palestinienne du conflit en reprenant les stratégies israéliennes d’isolement du Hamas et les tensions entre l’autorité palestienne et l’acteur principal de la bande de Gaza. Ce que la guerre à Gaza (2009) a par exemple modifié dans le conflit global israélo-palestinien, c’est la prise en considération du Hamas en tant qu’interlocuteur dans les négociations. Avant cet événement, ce statut était exclu étant entendu que la scène internationale considérait le Hamas comme un groupe terroriste avec lequel la négociation ne pouvait se faire. La deuxième approche proposée par cette communication rejoint une analyse de la redéfinition des frontières du conflit israélo-palestinien en promouvant un élargissement de ce dernier : préférant le qualificatif « israélo-arabe ». Nous démontrerons en effet que la considération israélo-arabe du conflit a, à nouveau, un intérêt certain. Partant, notre analyse axe, d’une part, son argument sur une prise en compte du Hamas par les États régionaux. Cette distinction est nécessaire pour comprendre comment la cause palestinienne peut tantôt faire l’objet d’un réel soutien de la part d’État régionaux, comme la Turquie, mettant un terme à des contrats avec Israël dès le conflit, tantôt être un « prétexte » de la part d’États régionaux, utilisant et instrumentalisant la confrontation avec Israël pour servir leurs propres intérêts. Nous pourrons dans ce cadre recourir à une étude portant sur la manière dont l’opinion publique a perçu le rôle des acteurs régionaux avec la consécration du président iranien comme défenseur de la cause palestinienne et l'arrivée de la Turquie dans le jeu régional se détachant un peu plus de l’Union européenne. Enfin, il convient, dans une troisième approche, d’élargir notre étude à l’implication de la scène internationale dans la région et aux nouvelles alliances. Le cas français est intéressant à ce propos car il se trouve en tension entre un soutien à Israël, sa relation avec la Syrie et une volonté de revenir en tant qu’acteur important au Moyen-Orient. Au même titre, la position américaine et, plus particulièrement, la politique d’Obama souhaitant se démarquer de la politique de Bush (cf. discours du Caire, juin 2009) relèvent d’un intérêt certain pour notre étude des nouvelles frontières du conflit israélo-arabe. [less ▲]

Synthesis and characterization of reversibly core cross-linked micelles sensitive to reductive environment

Poster (2011, May 12)

Progress in cobalt-mediated radical polymerization

Poster (2011, May 12)

Chitosan-based nanofibers for wound dressing

Poster (2011, May 12)

Stimuli-responsive triblock copolymer for biomedical applications

Poster (2011, May 12)

Design of Photoreactive Orthosteric GABAA Ligands Potentially Useful for Studying Localization and Function of GABAA Receptors

Poster (2011, May 08)

Evaluation des performances du microPET Siemens FOCUS 120 pour l’Iode 124 en utilisant la norme NEMA NU4-2008

Poster (2011, May 07)

Spatial dynamics of wild boar population: Insights from a hunters' survey

Poster (2011, May 02)

Regio-selective enzymatic acidolysis combined with dry fractionation to formulate CBE: Optimization of the enzymatic reaction

Poster (2011, May)

Treatment of a case of trichurosis (Trichuris suis) in pigs

Poster (2011, May)

Trichuris suis infection was identified in a pig herd during an investigation into persistent diarrhea and weight loss in 10 recently introduced gilts. Eggs of the parasite were identified in faeces of ... [more ▼]

Trichuris suis infection was identified in a pig herd during an investigation into persistent diarrhea and weight loss in 10 recently introduced gilts. Eggs of the parasite were identified in faeces of gilts. Further investigations failed to detect other causes of diarrhea but, in all production stages, they allowed the detection of eggs of Trichuris suis that could explain pasty faeces sometimes observed in weaned sows and frequent diarrhea found in the early fattening period. The administration of levamisole (intramuscular injection) to gilts allowed the excretion of adult parasites, the treatment of diarrhea and the reduction of the number of eggs per gram of faeces. Taking into account the success obtained with levamisole in gilts, the equipment of the farm and the wish of the farmer no to inject finishing pigs, an unsuccessful treatment was tried based on levamisole in drinking water every 8 and then 5 weeks. Flubendazole was finally administrated in drinking water every 3 and then 5 weeks, reducing significantly the number of eggs per gram of faeces. [less ▲]

Effect of benzoic acid analogs on myeloperoxidase activity measured by a new technique to study their direct interaction with the enzyme.

Poster (2011, May)

Myeloperoxidase (MPO) plays a key role in inflammatory response and constitutes a target for new drug development. The effects of some benzoic acid analogs were studied on the specific activity of human ... [more ▼]

Myeloperoxidase (MPO) plays a key role in inflammatory response and constitutes a target for new drug development. The effects of some benzoic acid analogs were studied on the specific activity of human MPO measured by SIEFED (“Specific Immunologic Extraction Followed by Enzymatic Detection”), an original method that consists of incubation of the compound with MPO, followed by capture of the enzyme by specific antibodies, washing (elimination of the compounds) and enzymatic detection of the immunocaptured enzyme. The compounds tested at 10-4, 10-5 and 10-6 M were studied in terms of structure activity relationship. Gallic acid (3,4,5-trihydroxybenzoic acid) with 3 hydroxyl groups had an important dose dependent inhibitory effect on MPO activity. Other molecules with less or without hydroxyl groups [3,4-dihydroxybenzoic acid, 2-hydroxybenzoic acid (salicylic acid) and benzoic acid] had rather an activator effect at 10-5 and 10-6 M. 2,4,6-Trihydroxybenzoic acid, with two hydroxyl groups adjacent to the carboxyl group, had a less efficient inhibitory effect. Caffeic acid (3,4-dihydroxycinnamic acid) with a propenoic acid group presented a dose dependent inhibitory effect on MPO activity contrary to its analog 3,4-dihydroxybenzoic acid. The esterification of the carboxyl group of gallic acid to obtain propyl gallate induced an activation of MPO at 10-5 and 10-6 M. Finally, the substitution of one or two hydroxyl groups by methoxyl ones (ferulic and syringic acids) decreased the efficiency of the molecules on the enzyme inhibition. The SIEFED technique appears as an innovative pharmacological tool to study the direct interaction of compounds with MPO. Number and position of hydroxyl groups and the extension of the carboxyl group of benzoic acid play a crucial role in the inhibition of MPO activity probably by facilitating the interaction with the active site or another elements of the enzyme structure. [less ▲]

Novel Application of the Lactoperoxydase system against postharvest diseases of the apple

Poster (2011, May)

Molecular dissection of the color-sided pehnotype in cattle reveals a novel mechanism of chromosome evolution involving circular shuttling intermediates.

Poster (2011, May)

Radiation-induced malignant peripheral nerve sheat tumors – a report of 2 cases

Poster (2011, May)

We discuss the case of two patients who developped delayed malignant peripheral nerve sheath tumor (MPNST) following radiotherapy. Case report: the first patient is a sixty year-old woman with a 2 years ... [more ▼]

We discuss the case of two patients who developped delayed malignant peripheral nerve sheath tumor (MPNST) following radiotherapy. Case report: the first patient is a sixty year-old woman with a 2 years history of right cervicobrachial pain and weakness. The neurological examination depicted severe weakness, atrophy and loss of sensation in the right C5 and C6 territories. A subclavicular hardened and enlarged lymph node was noted. Her past medical history was notable for a Hodgkin’s disease (HD) treated with radiation therapy (>40Gy) 35 years earlier. Brachial plexus MRI revealed a tumoral mass arising from the right brachial plexus. Biopsy of the subclavicular mass revealed a poorly differentiated malignant tumour consisting of spindle cells showing moderate polymorphism and a high mitotic index. Immunohistochemistry showed positivity for the S-100 protein, the CD56 and for the epithelial membrane antigen (EMA) and a diagnosis of MPNST of the brachial plexus was proposed. The second case is a 36 year-old man referred for a history of right sciatic neuralgia that appeared 3 years earlier. The medical history of the patient was notable for a right seminoma, treated by orchidectomy and prophylactic radiotherapy (24 Gy) 5 years earlier. The neurologic examination revealed right L5 and S1 radicular territories involvement, and the CT of the pelvis demonstrated a nodular mass at the level of the greater sciatic foramen. A surgical biopsy was performed and the neuropathological findings were consistent with a diagnosis of low-grade MPSNT. Discussion: MPNSTs are rare tumors accounting for 3 to 10% of all tissues sarcomas. Half of the cases described are sporadic, while the other half tend to appear in patients suffering from tumor prone conditions, such as neurofibromatosis type 1. Although secondary neoplasms are known complications of radiotherapy, descriptions of peripheral nerve sheath tumors (PNST) are scarce. The exact pathophysiology of radiation-induced PNSTs remains unclear but vascular alterations, direct damages to axon or Schwann cell and nerve compression by soft tissue fibrosis are thought to play a role. Although surgical removal sometimes followed by chemotherapy is the mainstay of MPNSTs, they usually carry a poor prognosis. Our 2 cases emphasize that the possibility of radiation-induced MPNST has to be kept in mind when investigating a localized neuropathy in a previously irradiated area. [less ▲]

Caractérisation physicochimique et évaluation de la qualité des dattes des cultivars de palmier dattier de la région de Figuig

Poster (2011, May)

Acaricidal activities of Santolina Africana and Hertia Cheirifolia, two endemic plants of north Africa, on the two spotted spider mite (Tetranychus urticae)

Poster (2011, May)

The two-spotted spider mite, Tetranychus urticae Koch, is a worldwide pest which feeds on a large variety of plant families. Because its resistance to acaricides is spreading rapidly, the development of ... [more ▼]

The two-spotted spider mite, Tetranychus urticae Koch, is a worldwide pest which feeds on a large variety of plant families. Because its resistance to acaricides is spreading rapidly, the development of new biological control tactics for population management is crucial. Plant extracts, such as Santolina africana and Hertia cheirifolia (Asteraceae), may represent viable alternatives, since they are currently considered to be minimumrisk pesticides. Although these two plants are known for their biocidal properties, the extract concentration that provides the most efficient control has not yet been precisely determined. In this study, we conducted a series of laboratory experiments to determine the susceptibility of adult females to different concentrations of S. africana and H. cheirifolia extract. These plants were steam-distilled and sprayed using a Potter spray tower. Mortality and fecundity were measured upon treatment with extract concentrations ranging from 0.07 to 6.75 mg/L. Female mortality increased with concentration, with LD50 values of 2.35 mg/L for S. africana and 3.43 mg/L for H. cheirifolia, respectively Reduced fecundity was previously observed at concentrations of 0.07, 0.09 and 0.29 mg/L .The chemical composition of the two oils were characterised by GC-MS. The most abundant components of the S. africana oil were terpinen-4-ol (44%), α- terpineol (11.31%) and borneol (6.73%). Camphor (15.11%), terpinen-4-ol (14.2%), α- terpineol (9.3%) were characteristic of the Hertia oil. [less ▲]

A method inspired by nature for the production of original and purified prebiotic preparations containing isomaltooligosaccharides and gluconic acid.

Poster (2011, April 29)

Establishment of an interactomic map of the Ets factors family: Towards a better understanding of their roles in oncogenic processes

Poster (2011, April 29)

Ets transcription factors have been involved in several cancers such as leukemia, prostate cancer and Ewing’s sarcoma. They regulate the expression of genes controlling important biological processes such ... [more ▼]

Ets transcription factors have been involved in several cancers such as leukemia, prostate cancer and Ewing’s sarcoma. They regulate the expression of genes controlling important biological processes such as cellular proliferation, differentiation, apoptosis, metastasis, and transformation. This family of transcription factors is characterized by its highly conserved DNA-binding domain called the ETS domain and members are classified into subfamilies based on sequence homology criterion. We built a protein-protein interaction (PPI) network of the 27 Ets proteins and of their individual functional domains using a high-throughput yeast-two hybrid (Y2H) screening method. That Y2H network was expanded with confident literature-curated PPIs to obtain a comprehensive Ets interaction network. By considering connectivity between Ets interaction partners, we were able to segregate highly connected clusters of proteins from that network. Analysis of ontologies enrichment of those clusters enabled to confirm well-established roles and regulations of Ets factors, but also to suggest new ones. Biological validation of one precise cluster could be used as a rule of a thumb to globally confirm the bioinformatic analysis of our Ets PPI network and the potential physiological or pathological roles and regulation of Ets factors. [less ▲]

Supercritical carbon dioxide as a green foaming agent: application for the purpose of polymer/carbon nanotube foams

Poster (2011, April 29)

Synthesis and characterization of reversibly cross-linked shape memory materials

Poster (2011, April 29)

Preparation and characterization of thermoresponsive gold nanohybrids

Poster (2011, April 29)

Synthesis of novel carbohydrate surfactants by combination of enzymatic catalysis and thiol-Michael addition

Poster (2011, April 29)

Cobalt-mediated radical copolymerization of conjugated and non-conjugated monomers

Poster (2011, April 29)

Describing Direct Speech in the Syntactic Reference Corpus of Medieval French (SRCMF)

Poster (2011, April 29)

Insect vectors of Lieschmania in Ghardaia (Algeria): Updated inventory of sand flies (Diptera: Psychodidae: Phlebotominae)

Poster (2011, April 18)

Distribution of main Bluetongue virus vectors on Belgium farms

Poster (2011, April 13)

Chemical composition of silage residues sustaining the larval development of the C. obsoletus/scoticus complex species (Diptera: Ceratopogonidae)

Poster (2011, April 13)

Variability of methane in the epilimnion of Lake Kivu

Poster (2011, April 08)

Seasonal and inter-annual variability of air-sea CO2 fluxes and seawater carbonate chemistry in the Southern North Sea

Poster (2011, April 08)

First assessment of the biogeochemistry of the Congo River and tributaries

Poster (2011, April 08)

Utilization of whole cell Green Fluorescent Protein (GFP) reporter systems as tracers to estimate the bioreactor efficiency

Poster (2011, April 07)

Isoprene and monoterpene emissions from a mixed temperate forest

Poster (2011, April 07)

Study of viability of Pseudomonas fluorescens BTP1 freeze-dried during storage at 4 and 20°C

Poster (2011, April 05)

The drying of bacteria remains a major alternative in order to keep them long term. After centrifugation, the bacterial pellet of Pseudomonas fluorescens BTP1 was divided in two fractions one with and one ... [more ▼]

The drying of bacteria remains a major alternative in order to keep them long term. After centrifugation, the bacterial pellet of Pseudomonas fluorescens BTP1 was divided in two fractions one with and one without cryoprotectants (2% glycerol and 5% maltodextrine) and freeze-dried. After freeze drying, powders were sealed in aluminium bag under vacuum and storage at 4 or 20°C. The storage stability of freeze-dried powders was studied by parameters such as loss of viability on the Plate Count Agar (PCA) (e.g. Concentration of Cells with glycerol (PG) at CFU/g before storage 109 and after 7 month, 108 at 4°C and 107 at 20°C) and evolution in membrane composition by measuring the ratio of unsaturated/saturated fatty acid. These ratios decrease in function of time (e.g. at 4°C the ratios of C18:3 and C18:2 by C16:0 decreases respectively of 0,013 to 0,001 and 0,05 to 0,03 after 60 days of storage). Viability (%) and concentration (CFU/g) of bacterial during storage at 4 or 20°C with aw = 0,32 was determined using a procedure published by (Kurtmann et al., 2009). In the present study, flow cytometric analysis was applied to evaluate the state in which are the cells at the end of storage time. Furthermore, we compared result the survival of bacteria as obtained by plate count with the flow cytometric analysis results. [less ▲]

Impact of the spatial resolution on the Greenland Ice Sheet Surface Mass Balance modelling using the regional climate model MAR with the aim to force an ice sheet model.

Poster (2011, April 05)

By using the regional climate model MAR (Modèle Atmosphérique Régional), validated for Greenland at 25km resolution and forced every 6 hours with the ERA-INTERIM reanalysis (Fettweis 2007, Fettweis et al ... [more ▼]

By using the regional climate model MAR (Modèle Atmosphérique Régional), validated for Greenland at 25km resolution and forced every 6 hours with the ERA-INTERIM reanalysis (Fettweis 2007, Fettweis et al. 2010), we have modelled the Greenland Ice Sheet (GrIS) Surface Mass Balance (SMB) at 20, 25, 30, 40 and 50km resolution to assess the impact of the spatial resolution. As part of the ICE2SEA project, the 25km-resolution SMB outputs of the MAR model are used as forcing fields for ice sheet models, in order to produce future projections of the GrIS contribution to sea-level rise over the next 200 years. Although the current spatial resolution of the MAR model (25km) is much higher than the general circulation models (GCM) resolution (150-300km), the ice sheet models often run at a higher resolution (typically 5-10km). Nevertheless, such higher-resolution runs of the MAR model on the same integration domain generate a significant additional computing time and are not doable until now. Moreover, conventional linear interpolations of the SMB outputs onto a higher-resolution grid, generally induce biases because ice sheet masks at different spatial resolutions do not match and the SMB is a very complex function of the spatial resolution and the topography . That is why several enhanced SMB interpolations are tested here in order to reduce biases when interpolating the MAR outputs onto higher resolution, in the framework of the ICE2SEA project. [less ▲]

Evolution of wind behaviour and of its potential for wind power production in Belgium during the last 30 years.

Poster (2011, April 04)

The number of wind turbines in the world grows significantly every year due to politics proposing green energy productions as solutions to mitigate climate change effects. However, this kind of energy is ... [more ▼]

The number of wind turbines in the world grows significantly every year due to politics proposing green energy productions as solutions to mitigate climate change effects. However, this kind of energy is dependent on the weather. This implies that the wind production is irregular at a very short time scale. But the short time scale availability of the wind-based energy is important to the producers of energy as well as to the electric grid managers because the wind energy production can rise or fall rapidly which creates some financial and voltage variations. For these reasons, we study the past evolution of the availability of the wind quantity by analysing the intermittence of the wind speed in Belgium during the last 30 years. To reach this goal, we use the regional model WRF (Weather and Research Forecast model) developed by the UCAR community users. The WRF model is forced by the NCEP2 Reanalysis model to obtain a regionalisation of the weather conditions over a domain centred on Belgium at a spatiotemporal resolution of 10 km and 1 min. This resolution allows to capture the minute-based time scale variability of wind speed and consequently the irregular behaviour of the wind power production. To obtain a value of the wind intermittence, we calculate the persistence of a wind blowing continuously with a minimum speed of 1 ms-1, then the persistence of a wind blowing continuously with a minimum speed of 2 ms-1, etc. The persistence of the wind speed and its evolution over 30 years are characterised by : (a) the mean wind speed over a fixed period (monthly, seasonally, … ), (b) the mean duration of a wind speed above x ms-1 over the same fixed period and (c) the evolution of (a) and (b) during the studied period. This study will show the evolution during the last decades of the wind behaviour in Belgium and its potential for electricity production. [less ▲]

Particulate carbon export during a bloom of Emiliania huxleyi in the Northwest European continental margin (northern Bay of Biscay)

Poster (2011, April 03)

Coccolithophores, the dominant pelagic calcifiers in the oceans, play a key role in the marine carbon cycle through calcification, primary production and carbon export, the main drivers of the biological ... [more ▼]

Coccolithophores, the dominant pelagic calcifiers in the oceans, play a key role in the marine carbon cycle through calcification, primary production and carbon export, the main drivers of the biological CO2 pump. Massive blooms of Emiliania huxleyi are observed each year at the continental margin of the Bay of Biscay. The BG02/11 cruise (RV Belgica), supported by near-real time remote sensing data, was conducted in early May 2002, along a transect on the outer shelf of the Northern Bay of Biscay between the La Chapelle Bank (southern region of the transect) and Goban Spur (northern region of the transect) (47.0°-50.5°N, 5.0°-11.0°W). Biogeochemical variables including primary production, calcification, partial pressure of CO2 (pCO2), chlorophyll-a (Chl-a), particle load, particulate organic and inorganic carbon (POC, PIC), Th-234 were measured in surface waters to assess particle dynamics, and carbon export in relation to the development of a coccolithophore bloom. We observed a marked northward decrease in water irradiance, Chl-a concentration and calcification rates: the bloom exhibited lower values and may have been less well developed in the Goban Spur area. There was also a large northward decrease in particulate 234Th settling fluxes along the transect from La Chapelle Bank to Goban Spur. The export fluxes of POC and PIC from the top 80 m, determined using the ratios of POC and PIC to Th-234 of particles, ranged from 81 to 323 mgC m-2 d-1 and from 30 to 128 mgC m-2 d-1, respectively. The highest fluxes were observed in waters presenting a well-developed coccolithophore bloom, as shown by high reflectance of surface waters. Despite the high calcification rates at the southernmost stations, surface waters were a net sink of atmospheric CO2 during this cruise. These results tend to demonstrate the enhancement of coccolithophore blooms on the efficiency of the surface community to export carbon to deep ocean. However, improvements in the estimation of POC and PIC export during coccolithophore blooms are needed to not only understand the present calcification to primary production (C:P) ratio, but also to help understand future sequestration of organic and inorganic carbon to the deep ocean. [less ▲]

Nursing care after Transcatheter Aortic Valve Implantation with the Medtronic CoreValve Revalving® system

Poster (2011, April 02)

The risks, complications and results of the transcatheter aortic valve implantation (TAVI) are widely described. But to our knowledge, no one has yet defined the nursing cares required after this ... [more ▼]

The risks, complications and results of the transcatheter aortic valve implantation (TAVI) are widely described. But to our knowledge, no one has yet defined the nursing cares required after this procedure and their effects on the TAVI results. The aims of this review are to describe the nursing cares required after TAVI and to determine which aspects of the management could be optimized to improve the results of the procedure. [less ▲]

Modelling the migration of a mid-Pleistocene erosion wave in the Ardennes (western Europe) drainage network: approach and first implications

Poster (2011, April)

Model parameterization through adjustment to field data is a crucial step in the modelling and the understanding of the drainage network response to tectonic or climatic perturbations. Using a data set of ... [more ▼]

Model parameterization through adjustment to field data is a crucial step in the modelling and the understanding of the drainage network response to tectonic or climatic perturbations. Using a data set of 18 knickpoints that materialize the migration of a 0.7-Ma-old erosion wave in the Ourthe catchment of northern Ardennes (western Europe) as a test case, we explore the impact of various data fitting on the calibration of the detachment-limited stream power model of river incision, from which a simple knickpoint celerity equation is derived. Our results show that statistical least squares adjustments (or misfit functions) based either on the stream-wise distances between observed and modelled knickpoint positions at time t = 0.7 Ma or on differences between observed (0.7 Ma) and modelled time at the actual knickpoint locations yield significantly different values for the m (more exactly, m/n) and K parameters of the model. As there is no physical reason to prefer one or the other approach, we suggest that an intermediate least rectangles adjustment might be the best compromise. In the Ourthe case, this leads to a m/n value lower than that obtained from the classical distance adjustment (0.79 against 0.86), leading to an increase in the non linear character of the dependence of knickpoint celerity on discharge. If we now recall that m/n = c(1-b) (Whipple & Tucker, 1999, JGR 104B: 17661-17674), where c and b are the exponents of the power law relations respectively linking discharge to drainage area and channel width to discharge, we can compare the calculated m/n value with that derived from field measurements of channel width, discharge and drainage area in the presently graded sections of the rivers. Such data taken from Petit et al. (2005, BSGLg 46: 37-50) allow us to derive m/n = 0.48 at equilibrium. As c may be considered constant, the higher m=n value obtained from the knickpoint retreat modelling must be ascribed to a lower b, i.e., to a channel narrowing associated with the transient phase of knickpoint migration. [less ▲]

Gold and silver nanomaterials based biosensors : a comparative study

Poster (2011, April)

Noble metal nanoparticles (NPs) are intensively studied due to their particular optical properties, mainly high optical absorption and diffusion yields, leading to interesting applications in biochemical ... [more ▼]

Noble metal nanoparticles (NPs) are intensively studied due to their particular optical properties, mainly high optical absorption and diffusion yields, leading to interesting applications in biochemical sensing, molecular tracking and imaging, drug delivery and photothermal therapies [1]. These unique optical properties arise from a physical process named surface plasmon resonance (SPR) which is a resonant coupling of incident light to the collective motion of electrons along the nanoparticles surface [2]. Optical SPR biosensors are able to measure complex formation in real time. Indeed, the SPR absorption spectrum band of the NPs is sensitive to the shape, size, inter-particle distance and composition of the NP as well as the dielectric properties of the surrounding medium [2]. Due to the sensitivity of SPR to the local dielectric environment, plasmonic NPs can thus act as transducers that convert small changes in the local refractive index or in the inter-particle distance into spectral shifts and broadenings of the absorption spectral bands [3]. Among metals, silver and gold NPs have received considerable interest for many reasons. For instance, they are stable in ambient atmosphere and exhibit good biocompatibility even if particular surface treatments are sometimes required. The Ag and Au NPs are also relatively easy to fabricate with different sizes and shapes allowing the tuning of the SPR optical absorption band from the near ultraviolet (400 nm) to the near infrared (1000 nm) wavelengths. In this study, our aim is to characterize two biosensors based on silver and gold spherical NPs in order to detect which one seems the best. Both NPs have a diameter close to 15 nm. We use the well-known biocytin-avidin complex as a model system because the bonding of avidin with biocytin is extremely strong with a dissociation constant three order of magnitude higher than the typical constants of antigen-antibody interactions. More precisely, we compare the intensities, the band shapes and the spectral locations of the SPR adsorption bands before and after the biomolecular recognition of avidin by biocytin molecules adsorbed on the Ag and Au NPs. The kinetic of the interaction is also discussed. Before surface treatment with biocytin, the NPs SPR bands are located around 390 and 520 nm for Ag and Au NPs, respectively. The SPR band intensity is higher for silver than for gold. Biocytin adsorption does not significantly modify the SPR spectral features. NPs do not therefore form aggregates and the local refraction index has not significantly changed. After avidin addition, a SPR red-shift and a broadening of the SPR bands are observed with both NPs as shown on Figure 1. These parameters evolved with time and reach their final values after around 45 min for each system. The aforementioned spectral changes arise from the biomolecular recognition process between biotin and avidin which leads to the NPs aggregation. The recognition process also induces a variation of the local refractive index around these NPs which contributes to the red-shift. The maximum SPR shifts are equal to 25 nm and 12 nm for silver NPs and gold NPs, respectively. Our results highlight the smaller dielectric sensitivity of gold NPs compared to the silver NPs one for a same particles’ size and for an equivalent concentration of avidin. The detection limit, described as the lowest concentration for clear identification of wavelength shift due to biomolecular recognition, is equal to 4 nM for both silver and gold NPs. With this protein concentration, 3 nm is the typical wavelength shift. The specificity of the biocytin - avidin biosensors is verified by replacing avidin by Bovine Serum Albumina (BSA). When BSA is added, we observe a SPR band shift which is smaller than the detection limit of 3 nm attesting the biosensor selectivity. Our work demonstrates the superiority of Ag over Au NPs for the elaboration of biosensors based on SPR. However, it is well-known that Ag NPs are less biocompatible than gold. This problem can be circumvented by an appropriate coating of the NPs surface prior ligand adsorption. [less ▲]

Study of dye coloration and electrolyte impregnation in mesoporous TiO2 for DSSC fabrication

Poster (2011, April)

SeaDataNet regional climatologies: an overview

Poster (2011, April)

In the frame of the SeaDataNet project, a set of regional climatologies for temperature and salinity has been developed by the different regional groups. The data used for these climatologies are ... [more ▼]

In the frame of the SeaDataNet project, a set of regional climatologies for temperature and salinity has been developed by the different regional groups. The data used for these climatologies are distributed by the SeaDataNet data centers. These climatologies have several uses: 1. The detection of outliers by comparison of the in situ data with the climatological fields; 2. The the optimization of locations of new observations; 3. The initialization of numerical hydrodynamic model; 4. The definition of a reference state to identify anomalies and to detect long-term climatic trends. These climatologies are produced with the help of the Data Interpolating Variational Analysis (DIVA) software. Here we present the latest developments in the regional climatologies along with the choice of parameters by the different groups. [less ▲]

Atmospheric mercury deposition during the last 1500 years in We Europe: The Misten peat bog record (Hautes Fagnes - Belgium)

Poster (2011, April)

The current rate of global atmospheric Hg deposition is approximately three times higher than the preindustrial record and it even increased by a factor of 2-10 in the industrialized regions ... [more ▼]

The current rate of global atmospheric Hg deposition is approximately three times higher than the preindustrial record and it even increased by a factor of 2-10 in the industrialized regions.....()(Hylander and Meili 2003). To determine the extent of such increase, it is necessary to quantify the atmospheric mercury concentration and its temporal variation. For this purpose four 1m Wardenaar peat cores (MIS01W, 04W, 0W5 and 06W) were collected in 2008 in the ombrotrophic Misten bog (Hautes Fagnes Plateau, East Belgium). Mercury was measured using a DMA 80 at the Laboratory of Mechanisms and Transfers in Geology in Toulouse (LMTG, France). The strongest mercury concentrations are measured in the upper half peat record, in a depth interval corresponding to the Industrial Revolution period. Mercury accumulation rate was estimated by applying a coupled 210Pb- 14C age model. The mercury accumulation rate remains relatively small, ranging between 0.9 and 3.3 g.m 2.y 1 during periods corresponding to the decline of Roman Empire and during the Middle Ages. Hg accumulation rate starts to increase when 25 cm, reaching a maximum value (> 115 g.m 2.y 1) at 13.7 cm (i.e.; 1923-1938 AD). Then the values oscillate to reach 9 g.m 2.y 1 at the peat surface (2000-2007AD). In the Misten bog, the evolution of Hg accumulation rate is in agreement with the chronology of other European peat records .......()(Roos-Barraclough et al. 2002). [less ▲]