References of "Poster"
     in
Bookmark and Share    
See detailX-ray emission from magnetic massive stars
Nazé, Yaël ULg; Petit, Véronique; Rindbrand, Mélanie et al

Poster (2014, August)

Detailed reference viewed: 7 (0 ULg)
Full Text
Peer Reviewed
See detailIdentification and comparison of proteome patterns of English Grain Aphids on resistant and susceptible wheat
Bosquée, Emilie ULg; Barrios San Martin, Joceline; C. RAMÍREZ, Claudio et al

Poster (2014, August)

Some varieties of wheat are resistant to some aphid clones of the English Grain Aphid (Sitobion avenae). This study used 2D-DIGE coupled with protein identification by Maldi-Tof-MS to compare the proteome ... [more ▼]

Some varieties of wheat are resistant to some aphid clones of the English Grain Aphid (Sitobion avenae). This study used 2D-DIGE coupled with protein identification by Maldi-Tof-MS to compare the proteome patterns of English Grain Aphids on resistant (Llareta) and susceptible (Huayún) wheat lines. Aphids were exposed to wheat during 2 weeks (short term: ST) and 4 weeks (long term: LT). Four treatments were compared: Llareta-ST, Llareta-LT, Huayún-ST, Huayún-LT. Experiment was conducted using different Sitobion avenae clones whose symbionts were previously characterized. Results showed that aphids had low performance on resistant plants. Seventy-two protein spots showed significant quantitative differences among the four treatment groups. Proteomic approach will allow a better understanding of interaction mechanisms between aphids and wheat. [less ▲]

Detailed reference viewed: 29 (10 ULg)
Full Text
See detailCrop association to improve aphid biological control
Chevalier Mendes Lopes, Thomas ULg; Bosquée, Emilie ULg; Bodson, Bernard ULg et al

Poster (2014, August)

This research focused on the development of sustainable alternative methods to control aphids, giving special emphasis on cultural practices and plant management systems. Increasing the diversity within ... [more ▼]

This research focused on the development of sustainable alternative methods to control aphids, giving special emphasis on cultural practices and plant management systems. Increasing the diversity within crops may have several beneficial effects on pest control, creating attractive habitats for indigenous beneficial fauna and simultaneously deterring pests (“push-pull” approach). In this field study, two wheat/pea associations (mixed cropping and strip cropping) where compared to monocultures of pea and wheat. The abundance and diversity of adult aphidophagous beneficials (predators and parasitoids) were accessed weekly, using yellow traps, while aphids were observed directly on plants. All individuals were identified down to the level of species. In both crops, the percentage of aphid infestation and density of colonies were significantly higher in monocultures during the abundance periods. The mixing was particularly beneficial for the pea, while strip cropping was more efficient for the wheat. Concerning beneficials, their abundance was also significantly higher in monocultures, comparing with the other treatments. This study shows that increasing diversity within crops can prevent them from aphid infestations. However, additional methods are needed to attract more efficiently the aphidophagous beneficials, in order to promote the natural control of aphids. [less ▲]

Detailed reference viewed: 32 (10 ULg)
Full Text
Peer Reviewed
See detailAphid - symbiont interactions : multitrophic "omic" approaches to investigate multitrophic interactions
Bosquée, Emilie ULg; Bauwens, Julien ULg; Mazzucchelli, Gabriel ULg et al

Poster (2014, August)

« Omics » found recent developments due to significant improvement and availability of both separation and identification methods. For proteomics, functional information’s linked to the studied proteins ... [more ▼]

« Omics » found recent developments due to significant improvement and availability of both separation and identification methods. For proteomics, functional information’s linked to the studied proteins was brought when compared to genomic approach. For these reasons, a panel of tools is available to determine the proteome patterns related to differential adaptation of insects to cope with plant defence mechanisms or to transmit virus. The adaptation and metabolic changes of aphids in relation to host plants focusing on the role of the bacterial endosymbionts was investigated. Use of artificial diet including diverse antibiotics but also the comparison of proteomes related to whole aphid and respective purified bacterial symbionts were studied to identify the respective origin and function of proteins constituting the studied proteomes. Diverse methods including 2D-DIGE, liquid chromatography coupled with mass spectrometry and data bank investigations were developed. From the proteome investigation, characterisation of good and bad virus vectors was also performed in different aphid - plant - virus models. Particular proteins of interest were selected. This broad proteomic approach will be discussed as an interesting and reliable tool to study the biologically involved proteins from aphids in response to several environmental changes [less ▲]

Detailed reference viewed: 32 (7 ULg)
Full Text
See detailPrediction of stock and fate of phosphorus forms according to soil classification
Renneson, Malorie ULg; Barbieux, Sophie ULg; Dufey, Joseph et al

Poster (2014, August)

Wallonia presents a high diversity of soils and the fate of P in the soil-plant systems can highly vary from one region to another. The fate of phosphorus depends upon its forms in the solid constituents ... [more ▼]

Wallonia presents a high diversity of soils and the fate of P in the soil-plant systems can highly vary from one region to another. The fate of phosphorus depends upon its forms in the solid constituents of soils, which is seldom characterized. For example, total P determines the soil reserve of P but also the potential P content which can be lost to surface water by erosion but analysis of this parameter is time consuming and rarely performed. This study aims (i) to define functional groups of soils for a differentiate P management, (ii) to estimate total soil P by regression equations based on soil parameters, and (iii) to estimate the quality of these predictions. The study consists in a characterization of 12 parent materials in Wallonia, collected across different land uses. A classification of soils was defined by clustering analysis and 5 groups were defined according to P contents and forms. Using this information in regression improved the quality of predictions. The coefficients of determination vary from 0.83 to 0.99, in comparison to a coefficient of 0.77 for the global regression. Then, pedotransfer functions were validated with an independent external dataset of 55 soils. Estimation of the quality of the prediction of P content (mean error, standard deviation of prediction and root mean square error) was made with global and local regression models. In conclusion, using a soil classification allowed to improve P content assessment by specific regressions and to propose differentiated P management for each group of soils. [less ▲]

Detailed reference viewed: 4 (2 ULg)
Full Text
See detailWhich P inputs are compatible with a sustainable agriculture at short and long-term?
Renneson, Malorie ULg; Dufey, Joseph; Roisin, Christian et al

Poster (2014, August)

During the past 20 years, there has been a constant reduction in mineral fertilizer use due to price increases and environmental concerns. These changes can lead to a decrease in soil P content, which is ... [more ▼]

During the past 20 years, there has been a constant reduction in mineral fertilizer use due to price increases and environmental concerns. These changes can lead to a decrease in soil P content, which is already observed in some regions in Wallonia. Some new issues are now emerging. Is current cropping systems compatible with yield maintenance? Do organic fertilizers have a similar effect than mineral fertilizers? To answer to these questions, a short-term experiment in controlled conditions and 2 long-term experimental plots were studied. The short-term experiment permitted to study the kinetics of P after an input and differences between fertilizer types, whereas the long-term experiments studied 3 levels of P and K input and different organic compounds. Although an evolution of P content was observed, no difference of yield was found before about 20 years. However, after 47 years, available P levels were considered as low in zero P-input plots and attention must now be focused on these parcels. Zero P-input caused a mean yield decrease of 7%, while a double input increased yield by 2% in comparison to plots with input corresponding to crop export. Thus the zero P-input option is rarely economically profitable in the long-term and providing double the amount of P removed is never financially sustainable. Finally, no difference of P content was observed between organic and mineral fertilizers, except for manure which engendered a higher P content. In conclusion, organic and inorganic fertilizers had a relatively similar effect and overlooking P fertilizer is possible in the short-term but P content has to be followed at the long-term, although yield loss was limited. [less ▲]

Detailed reference viewed: 1 (0 ULg)
See detailX-raying the winds of the evolved massive binary HDE228766
Rauw, Grégor ULg; Mahy, Laurent; Nazé, Yaël ULg et al

Poster (2014, August)

Detailed reference viewed: 8 (1 ULg)
Full Text
See detailMorphological and functional characterization of Carnobacterium maltaromaticum isolated from vacuum-packed beef with long shelf life
Didimo Imazaki, Pedro Henrique ULg; Tahiri, Assia ULg; Ndedi Ekolo, François et al

Poster (2014, August)

The aim of this study was to perform a morphological and functional characterization of a Carnobacterium maltaromaticum strain with a potential bioprotective effect isolated from vacuum packaged long ... [more ▼]

The aim of this study was to perform a morphological and functional characterization of a Carnobacterium maltaromaticum strain with a potential bioprotective effect isolated from vacuum packaged long shelf life beef. The morphological, biochemical and enzymatic profiles, the influence of different temperatures and atmospheres, and the microbial stability of fresh beef inoculated with the C. maltaromaticum strain were evaluated. The isolated C. maltaromaticum strain presented similar morphological, biochemical and enzymatic profiles as those of two reference strains (LMG 11393 and LMG 22902). The growth of C. maltaromaticum was slower in an atmosphere containing O2 and CO2. Vacuum packing is therefore suitable for this bacterium. An antimicrobial effect against Enterobacteriaceae was highlighted on inoculated fresh meat stored under N2. The functional characterization of this isolate will be further pursued by a genotypic characterization to better understand its potential bioprotective effect. [less ▲]

Detailed reference viewed: 15 (0 ULg)
Full Text
Peer Reviewed
See detailIdentification of lectins as virus competitors in aphid vectors: from fundamental to applied approaches
Bosquée, Emilie ULg; Chen, Ju Lian; Yong, Liu et al

Poster (2014, August)

Aphids remain difficult virus vectors to be controlled in many crops. Within this context of biological control against aphids and investigation on virus transmission (both non persistent Potato virus Y ... [more ▼]

Aphids remain difficult virus vectors to be controlled in many crops. Within this context of biological control against aphids and investigation on virus transmission (both non persistent Potato virus Y (PVY) and Cucumber Mosaic Virus (CMV) and persistent Barley Yellow Dwarf Virus, the use of lectins was developed. Indeed, the effects of lectin binding to glycoprotein aphid receptors on virus transmission were tested in laboratory via the use of artificial diets using different virus models. Differential effects on virus transmission efficiency were determined. By example, a strong interference between GNA and PVY was observed. In consequence, the lectin was considered as promising proteins and could be potential competitors to virus. For further research, a fast protein liquid chromatography was performed to identify aphid proteins related to binding to efficient lectin competitors. Moreover, to detect involved proteins in aphids, two-dimensional gel electrophoresis approach coupled to mass spectrometry was developped to identify the glycosylated proteins determining virus transmission efficiency. Use of lectins for both fundamental and applied approaches were discussed to investigate aphid – virus interactions [less ▲]

Detailed reference viewed: 19 (4 ULg)
Full Text
See detailRole of non-polyQ regions on the aggregation process by polyQ proteins into amyloid fibrils
Huynen, Céline ULg; Willet, Nicolas ULg; Buell, Alexander K et al

Poster (2014, July 28)

Nine neurodegenerative disorders, referred to as polyglutamine diseases and including Huntington’s disease, are associated with the abnormal expansion of a polyglutamine tract inside nine unrelated ... [more ▼]

Nine neurodegenerative disorders, referred to as polyglutamine diseases and including Huntington’s disease, are associated with the abnormal expansion of a polyglutamine tract inside nine unrelated proteins. This polyQ expansion is thought to be the major determinant in the development of neurotoxicity, triggering protein aggregation into amyloid fibrils. A large body of evidence however indicates that non-polyQ regions modulate the aggregation process triggered by polyQ expansions. The interplay between the polyQ tract and non-polyQ regions is complex and still not fully understood. In order to better understand it, we previously designed and characterized model polyQ proteins made of the beta-lactamase BlaP and a 23, 30, 55 or 79Q tract inserted in position 197 or 216. These chimeras recapitulate the aggregation properties of polyQ disease-associated proteins: there is a Q threshold for the formation of amyloid fibrils, and above the threshold, the longer the polyQ, the faster the aggregation. Moreover, the structure of BlaP (native or unfolded) and the position of insertion of the polyQ tract (197 versus 216) influence their aggregation properties. In this work, (i) we will discuss the role of the conformation of the host protein, BlaP, and of the location of the polyQ within BlaP on the different phases of amyloid fibril formation, the nucleation and elongation steps, using mainly quartz crystal microbalance (QCM), atomic force microscopy (AFM) and dynamic light scattering (DLS); and (ii) we will investigate the precise aggregation threshold and the modulating role of the N- and C-terminal polyQ flanking sequences in position 197 of BlaP by creating and characterizing new chimeras containing intermediate length polyQ tracts in position 197, or polyQ tracts inserted between two cleavage sites in position 197, respectively. Our results highlight a linear dependence of the polyQ length on the elongation rate whatever the insertion site and the conformation of BlaP. These two parameters however drastically influence the ability of a polyQ tract to trigger the nucleation and the elongation steps of amyloid fibril formation. Finally, we observed that the propensity to form amyloid fibrils and its rate seems to be largely dependent on the polyQ length and on the polyQ flanking sequences. Altogether our results contribute to identify the important species and elements (polyQ or non-polyQ regions, monomers, oligomers or fibrils) during the aggregation process into amyloid fibrils to interfere with the latter associated with neurotoxicity. [less ▲]

Detailed reference viewed: 2 (0 ULg)
Full Text
Peer Reviewed
See detailResorcinol-Formaldehyde Carbon Xerogels as Lithium-Ion Battery Anodes: Synthesis, Grinding, Coating on current collector and Electrochemical characterization
Piedboeuf, Marie-Laure ULg; Léonard, Alexandre ULg; Pirard, Jean-Paul ULg et al

Poster (2014, July 17)

Rechargeable lithium-ion batteries show great advantages over traditional batteries and are extensively used for consumer electronic devices due to their high energy density and long cycle life. However ... [more ▼]

Rechargeable lithium-ion batteries show great advantages over traditional batteries and are extensively used for consumer electronic devices due to their high energy density and long cycle life. However, the improvement of performance of current lithium-ion batteries requires the optimization of the materials used (electrolyte and electrodes). Therefore, tremendous efforts have been dedicated to exploring new materials with high capacity, excellent cycling performance, low cost and high safety features [1-4]. As an example, carbon xerogels are promising candidates in the development of new high performance C-based anode materials for Li-ion batteries, since such carbonaceous materials show very small changes of volume during the charge/discharge process, providing an improved cycle life. Nevertheless, hard carbons also exhibit quite high irreversible capacity losses due to their intrinsic high microporosity and, compared to graphite, a poor rate performance related to slow diffusion of Li in the internal structure [5-6]. To reduce these disadvantages, the structural and textural characteristics need to be carefully controlled. Also, due to the different morphology of these materials compared to graphite, the deposition of carbon xerogels on current collectors needs to be studied in detail. In this work, porous carbon xerogels were synthetized from Resorcinol-Formaldehyde mixtures by adjusting the pH of the solution in order to obtain different mesopore sizes. Monoliths of carbon xerogels were obtained after drying of the polymer gel and pyrolysis [7]. Mercury intrusion porosimetry and nitrogen adsorption techniques (BET) was used to characterize the pore texture of the carbon xerogels. These monoliths were ground to particles around 10 µm for all the samples. The resulting powders were then mixed with a binder and a solvent to form slurries and then cast on copper foil using a bar coater. After evaporation of the solvent, the resulting coatings were analyzed using scanning electron microscopy (SEM) for the morphology and their thickness was monitored by profilometry. The resulting electrodes were subjected to electrochemical characterization. Since the particle sizes and the method of coating was the same for all the samples, it was possible to evaluate selectively the influence of the textural and structural parameters of the different carbon materials on their performances. Electrochemical characterizations were performed using charge-discharge galvanostatic curves and cyclic voltammetry in Li/C half cells between 0.005 and 1.5 V vs. Li+/Li. References 1) Goodenough J.B., Kim Y. J. Power Sources 2011; 196(16): 6688-6694. 2) Bruce P.G. Solid State Ionics 2008; 179: 752-760. 3) Armand M., Tarascon J.-M., Nature 2008; 451: 652-657. 4) Scrosati B., Garche J., J. Power Sources 2010 ; 195 : 2419-2430. 5) Yuan X., Chao Y.-J., Ma Z.-F., Deng X., Electrochemistry Communications 2007 ; 9 : 2591-2595. 6) Zanto E.J., Ritter J.A., Popov B.N., Proceedings - Electrochemical Society 1999; 98-16: 71-8. 7) Job N., Théry A., Pirard R., Marien J., Kocon L., Rouzaud J., Béguin F., Pirard J. Carbon 2005; 43: 2481-2494. [less ▲]

Detailed reference viewed: 69 (2 ULg)
Peer Reviewed
See detailFrom variability to stability: The acquisition of phonemes in French speaking children aged 30 to 53 months.
MacLeod, Andrea; Maillart, Christelle ULg

Poster (2014, July 16)

When children first begin to produce the phonemes of their language, their productions are characterized by a high degree of variability (e.g., Ferguson & Farwell, 1975). As children’s phonological ... [more ▼]

When children first begin to produce the phonemes of their language, their productions are characterized by a high degree of variability (e.g., Ferguson & Farwell, 1975). As children’s phonological representations become more defined, their productions become more stable. In fact, the observation of variability beyond the early-word stage has been used as a diagnostic criteria for sub-types of phonological disorders (Dodd et al. 2005). Despite the clinical significance of phonological variability, there exists no normative data that can be used to objectively describe this variability in French. The goal of the present study was to describe variability and stability among French-speaking children between the ages of 30 and 53 months. A total of 153 children participated in the present study and were equally distributed in four groups (aged 30-35, 36-41, 42-47, and 48-53 months). We created a picture identification task with 65 target words, which contained the consonants of French in word initial, medial and final position. The children were asked to produce this series of words three times. Two measures of variability were used. (1) A consonant level analysis that investigated the stability of consonants regardless of word or syllable position. (2) A word level analysis that investigated the consistency of productions across the three series (Holm et al., 2007). The preliminary analysis focused on the consonant level analysis and revealed that the youngest group of children aged 30 to 35 months were significantly more variable than the oldest group aged 48-53 months. This shift from variability to stability will be discussed in terms of the development phonological representations. In addition, the clinical significance of variability will be discussed in light of these findings. [less ▲]

Detailed reference viewed: 37 (2 ULg)
Peer Reviewed
See detailModification of Conductivity, Superhydrophilicity and Photocatalytic Activity of TiO2 Thin Films Through Carbon Nanotubes Doping
Léonard, Géraldine ULg; Remy, Simon; Malengreaux, Charline ULg et al

Poster (2014, July 15)

In this work, a superhydrophilic and photocatalytic material allowing to reduce the accumulation of electrostatic charges is developed. The superhydrophilicity and photocatalytic activity of TiO2 films ... [more ▼]

In this work, a superhydrophilic and photocatalytic material allowing to reduce the accumulation of electrostatic charges is developed. The superhydrophilicity and photocatalytic activity of TiO2 films provide the “easy-to-clean” property. Indeed, superhydrophilicity induces a very low contact angle between TiO2 and water leading to the formation of a water film at the surface of the material. The photocatalytic activity, responsible for the pollutant decomposition, is explained by the excitation of the semiconductor under UV light leading to the formation of electron-hole pairs. The electrical conductivity of semiconductor TiO2 is very low leading to the accumulation of electrostatic charges and so the surface becomes a dust trap. Multi-walled carbon nanotubes (MWCNTs) are electrical conductors and their introduction in TiO2 could increase the conductivity. The incorporation of MWCNTs can modify the superhydrophilicity of TiO2. The photoactivity can be improved by reducing the electron-hole recombination rate. MWCNTs play a role in electron transfer and allow to decrease the recombination of electron-hole pairs. Two sol-gel syntheses were studied in alcohol and water respectively. In the alcoholic medium, monolayer films are obtained by dip-coating on alkaline free glass and calcined at 300, 400 or 500°C. The thermal treatment allows to crystallize TiO2 in the anatase form. In the aqueous synthesis, monolayer film are obtained by dip-coating on alkaline free glass. The TiO2 shows already the anatase structure. The characterizations of the samples have confirmed the nanotube presence in the aqueous synthesis, and in the alcoholic synthesis at 300°C and 400°C but not at 500°C. The highest conductivity is obtained from the syntheses in alcohol and the calcination at 300°C. That sample does not exhibit a high photoactivity because of its poor crystallinity. The films without MWCNTs are superhydrophilic but the contact angle increase with the incorporation of MWCNTs. The superhydrophilicity is lost with MWCNTs introduction. MWCNTs increase the roughness, the thickness and the electron transfer of the TiO2 matrix. This induces an enhancement of the photoactivity under UV. The comparison between the two syntheses shows that the alcoholic synthesis (400°C) is the best for pure film. When MWCNTs are introduced, the improvement is higher in the case of aqueous synthesis than in the case of alcoholic synthesis. The aqueous synthesis leads to more active photocatalysts than the alcoholic synthesis. [less ▲]

Detailed reference viewed: 38 (2 ULg)
Peer Reviewed
See detailAre expectancies and peers involved in the relation between depressive mood, anxiety and cannabis use in adolescence?
Schmits, Emilie ULg; Quertemont, Etienne ULg; Boulard, Aurore ULg

Poster (2014, July 15)

Background: Cannabis is the most commonly used illicit drug among teenagers and depression is one of the most common psychopathologies in adolescence. The specific symptom of depressive mood is present in ... [more ▼]

Background: Cannabis is the most commonly used illicit drug among teenagers and depression is one of the most common psychopathologies in adolescence. The specific symptom of depressive mood is present in 30% to 40% of adolescents in regular school settings. Links between cannabis use and depression have been highlighted, especially in adolescence. But questions remain about the strength of the association between lifetime cannabis use, depressive mood and anxiety, and about the mechanism underpinning the link. Aim: The aim of this study was to clarify the relationship between depressive mood and lifetime cannabis use in adolescents, particularly through the mediating role of anxiety and cannabis use effect expectancies, and the moderating role of peer cannabis use. Methods: A questionnaire was administered to 1,246 Belgian teenagers aged 16–17 years. ANOVA, chi-square, logistic regressions and mediation/moderation analyses were carried out to model lifetime cannabis use. Results: Depressive mood was positively correlated with lifetime cannabis use. Social anxiety, trait-anxiety and cognitive impairment effect expectancies mediated the effect of depression on lifetime cannabis use. The direct effect of depression on lifetime cannabis use increased when mediators were introduced into the relation, revealing their suppressive effects. The number of peer cannabis users moderated this model. Conclusion: Findings are discussed in terms of potential risk factors (depressive mood) or protective factors (anxiety and expectancies) for lifetime cannabis use, including the self-medication hypothesis. [less ▲]

Detailed reference viewed: 31 (9 ULg)
Peer Reviewed
See detailDo tree species influence community structure and richness of Ammonia Oxidizing Bacteria at three temperate forest sites?
Malchair, Sandrine ULg; Carnol, Monique ULg

Poster (2014, July 15)

Introduction: The relationship between biodiversity and ecosystem function remains a controversial subject with numerous open questions. In Europe, the conversion of coniferous monocultures into ... [more ▼]

Introduction: The relationship between biodiversity and ecosystem function remains a controversial subject with numerous open questions. In Europe, the conversion of coniferous monocultures into broadleaved or mixed stand is considered to face ecological and economical risks posed by coniferous monocultures. Belowground effects of such a change in the dominant tree species is however largely unknown, although bacteria regulate many soil processes and some groups, like ammonia oxidizing bacteria (AOB) are highly sensitive to environmental stress. Objectives: The aims of this study were to investigate (i) AOB community structure and richness under several tree species, (ii) microbial/environmental factors related to AOB diversity, (iii) the relationship between AOB diversity and the nitrification process. Materials and methods: Forest floor (Of, Oh) was sampled under European beech, sessile oak, Norway spruce and Douglas fir at three sites. AOB community structure and richness was assessed by PCR-DGGE and sequencing. Samples were analysed for net N mineralization, potential nitrification, basal respiration, microbial biomass, microbial or metabolic quotient, pH, total nitrogen, extractable ammonium, organic matter content and exchangeable cations. Results: AOB community structure and tree species effects on AOB diversity were site-specific. Factors regulating ammonium availability, i.e. net N mineralization or microbial biomass, were related to AOB community structure. AOB richness was not related to nitrification. Conclusions: Our research revealed that, at larger spatial scales, site specific characteristics may be more important that tree species in determining AOB richness and community structure. Within sites, tree species influence AOB diversity. The absence of a relation between AOB richness and nitrification points to a possibly role of AOB abundance, phenotypic plasticity or the implication of ammonia oxidizing archaea in this process. [less ▲]

Detailed reference viewed: 35 (2 ULg)
Peer Reviewed
See detailStudies of early interactions among infants aged 4 to 6 months furtherly diagnosed with autistic spectrum disorder and their developmental trajectories and outcome at 4 years old.
Boulard, Aurore ULg; Wolff, Marion; Morange-Majoux, Françoise et al

Poster (2014, July 14)

The purpose of this study is to observe and analyze the social skills of infants aged 4 to 6 months later diagnosed with autism. Through the family films collected, we compared 28 children later diagnosed ... [more ▼]

The purpose of this study is to observe and analyze the social skills of infants aged 4 to 6 months later diagnosed with autism. Through the family films collected, we compared 28 children later diagnosed with autism to 28 typically developing children strictly matched on chronological age and sex. To do this, we used the social behavior assessment scale (SBAS). This scale measures the behavior of the infant (turning his head, looking, smile, vocalize ...) in response to 5 parental stimuli (1.calling by her / his name, 2.saying peek-a-boo, a vocal sound 3.Producing , 4.filmed in silent 5.simultaneous interactions with one or more persons). Then we analyzed the responses behaviors of these children with the software "the observer". Results show evidence that, contrary to infants with typical development, infants later diagnosed as autistic made less visual contact, smile or vocalize less in response to parental stimuli. However, even if the responses of autistic children are statistically different in quantity (compared to the control group), responses to parental stimuli are still present. In a second step, we studied the developmental trajectories of children with autism. Our hypothesis was that children with a low score at the SBAS would have a lower global development score than the children with a high score at the SBAS at 3 years old. Our results validate our hypothesis. [less ▲]

Detailed reference viewed: 47 (4 ULg)
Full Text
Peer Reviewed
See detailSelf broadening coefficients and improved line intensities for the n7 band of C2H4 near 10.5 mm, and impact on ethylene retrievals from Jungfraujoch solar spectra
Vander Auwera, Jean; Fayt, André; Tudorie, Marcela et al

Poster (2014, July 10)

Ethylene (ethene, C2H4) is a tropospheric pollutant on the Earth, also present as a by-product of methane photochemistry in the atmosphere of outer solar system bodies. Remote sensing of ethylene in the ... [more ▼]

Ethylene (ethene, C2H4) is a tropospheric pollutant on the Earth, also present as a by-product of methane photochemistry in the atmosphere of outer solar system bodies. Remote sensing of ethylene in the infrared range relies on the 10 mm region. This spectral range corresponds to the excitation of 7 modes of vibration of 12C2H4, 4 of which being infrared active (see Fig. 1 of [1]). The corresponding n10, n7, n4 and n12 bands are located near 826, 949, 1026 and 1442 cm-1, respectively [1]. Among these, the n7 band is the strongest, indeed used for remote sensing measurements of ethylene. Relying on high-resolution Fourier transform infrared (FTIR) spectra recorded in Brussels, the present work involved extensive measurements of individual line intensities and self broadening coefficients for the n7 band of 12C2H4. Compared to the corresponding information available in the latest edition of the HITRAN spectroscopic database (HITRAN 2012 [2]), the measured line intensities were found to be higher by about 10 % for high J lines in the P branch and lower by about 5 % for high J lines of the R branch, varying between these two limits roughly linearly with the line positions. Test calculations performed in this work indicated that these discrepancies could result from the relative values of the transition moments of the n10, n7 and n12 bands used when the information provided in HITRAN was generated (the transition moment of the n4 band was set to zero). The measured self broadening coefficients exhibit a dependence on both J and Ka, which was modeled empirically. The spectroscopic information for ethylene available in HITRAN 2012 was modified to match the present observations. The impact of these modifications on retrievals of atmospheric ethylene was then evaluated via FTIR retrievals in the 949.0 – 952.0 cm-1 microwindow, from a subset of ground-based high-resolution FTIR solar spectra recorded at the Jungfraujoch station. The new line intensities were found to lead to a reduction of the measured total columns of ethylene by -4.1±0.1 %, compared to the use of HITRAN 2012. [less ▲]

Detailed reference viewed: 18 (2 ULg)
Full Text
See detailLarge-scale stochastic optimization using non-stationary geostatistics for uncertainty assessment of groundwater flow and solute transport, in the framework of a near surface radioactive waste disposal
Rogiers, Bart; Laloy, E.; Gedeon, Matej et al

Poster (2014, July 09)

Uncertainty quantification is very much needed to support decision making related to e.g. environmental impact assessment for waste disposal sites. A probabilistic result provides a much stronger basis ... [more ▼]

Uncertainty quantification is very much needed to support decision making related to e.g. environmental impact assessment for waste disposal sites. A probabilistic result provides a much stronger basis for decision making compared to a single deterministic outcome. Accurate posterior exploration of high-dimensional and CPU-intensive models, which are often used for environmental impact assessment, is however a challenging task. To quantify the uncertainty associated with solute transport in the framework of a near surface radioactive waste disposal in Mol/Dessel, Belgium, we investigate combining the adaptive Metropolis (AM) McMC algorithm for updating the global model parameters, and adaptive spatial resampling (ASR) for updating of the spatially distributed model parameters, by block sampling. The forward model used is a groundwater flow model conditioned on borehole and direct push data, that accounts for non-stationary heterogeneity in hydraulic conductivity. The obtained flow solutions are used for solute transport simulations, and the results are compared with a different groundwater flow model parameterization, that makes use of homogeneous hydrogeological layers. Moreover, a number of simulations is performed to assess the effect of realistic dispersivity, which is derived from outcrop investigations. The obtained results indicate that the combination of AM and ASR using block sampling seems not to be very efficient for McMC sampling with the forward model used in this study. However, using the algorithm in optimization mode seems to work fine, and provides an alternate way for exploring the parameter space and the prediction uncertainty. [less ▲]

Detailed reference viewed: 19 (0 ULg)
Full Text
Peer Reviewed
See detailWhich links exist between depression, engagement in activities’ level and several psychological processes?
Wagener, Aurélie ULg; Blairy, Sylvie ULg

Poster (2014, July 09)

In Europe, depression affects 33.4 millions of people every year. According to the World Health Organization, depression will be the leading cause of disabilities in 2030. This highlights the need for ... [more ▼]

In Europe, depression affects 33.4 millions of people every year. According to the World Health Organization, depression will be the leading cause of disabilities in 2030. This highlights the need for available, effective and efficient treatments of this psychopathology. In order to offer such treatments, there is a need for a deep understanding of depression’s mechanisms. Depression is characterized by a decrease of the level of engagement in activities: for instance, depressed patients stay in bed, don’t see friends, don’t go out anymore and can be on sick leave for a long period of time. Reciprocally, this decrease maintains depressive symptoms. This link between depression and level of engagement in activities is well-established in the scientific literature. However, no study has, until yet, determined which psychological processes are mediators of this link. Therefore, this study’s aim is to determine these psychological processes. In order to reach this aim, 500 subjects, suffering from psychopathology or not, will fulfill a set of questionnaires. These questionnaires will assess mood (anxiety and depression), level of engagement in activities and five categories of psychological processes that have been selected from different theoretical models of depression (self-image, environmental satisfaction, negative repetitive thoughts, experiential avoidance and emotional regulation). Statistical analysis will be performed in order to confirm a LISREL model. Data collection is ongoing and results will be presented and discussed during the congress. [less ▲]

Detailed reference viewed: 20 (2 ULg)
Peer Reviewed
See detailA longitudinal perspective of alcohol use among adolescents: the predictive role of peers and internalizing factors.
Schmits, Emilie ULg; Glowacz, Fabienne ULg; Quertemont, Etienne ULg

Poster (2014, July 09)

Alcohol is the most commonly used psychoactive substance among teenagers. Consumption is influenced by environmental factors and personal characteristics, events or experiences. High use can lead to ... [more ▼]

Alcohol is the most commonly used psychoactive substance among teenagers. Consumption is influenced by environmental factors and personal characteristics, events or experiences. High use can lead to substantial problems, especially after an early consumption. Detecting and preventing an increase of alcohol use among teenagers, through the identification of risk and protective factors, seems essential in terms of public health. This study aimed to examine the progression of use in young teenagers, to identify protective and risk factors of alcohol use (including peers and internalizing factors) and to specifically focus on the influence of social anxiety. A questionnaire was administered twice to 877 teenagers (49.94% female, M=15.61) with one year interval (T1 and T2). Sex, age, alcohol use, number of friends, social comparison, trait-anxiety, social anxiety and depression were assessed through validated scales. T-test for paired sample and hierarchical regressions were performed. During the follow-up year, the average alcohol use significantly increased. A positive social comparison at T1 significantly predicted alcohol use at T2. The more teenagers positively compared themselves to their friends and felt popular, the more they consume alcohol. A similar significant effect was demonstrated for depression. The more young people manifested depressive affects at T1, the more they used alcohol at T2. However, social anxiety significantly protected from this substance use. More social anxiety at T1 was associated with less alcohol consumption at T2. The number of friends and trait-anxiety at T1 did not significantly influence alcohol use at T2. A positive social comparison and depressive affects could be considered as risk factors, whereas social anxiety could be defined as protective factor. At this developmental period, young people suffering from social anxiety symptoms subsequently use less alcohol, maybe due to the lack of contact with this substance usually socially consumed, whereas more popular and integrated teenagers are more at risk. The present results challenge the tension-reduction model according to which alcohol is consumed to reduce anxious affects and to facilitate social relationships. However, results suggest that alcohol might be used to reduce unpleasant depressive affects. [less ▲]

Detailed reference viewed: 31 (4 ULg)
Full Text
Peer Reviewed
See detailEtude de la notoriété des sportifs belges francophones de haut niveau
THEUNISSEN, Catherine ULg; Danse, Nicolas; Cloes, Marc ULg

Poster (2014, July 03)

L’objectif de cette étude est d’analyser la notoriété des sportifs belges francophones de haut niveau ainsi que l'image de la population à leur égard. Pour obtenir ces informations, nous avons choisi ... [more ▼]

L’objectif de cette étude est d’analyser la notoriété des sportifs belges francophones de haut niveau ainsi que l'image de la population à leur égard. Pour obtenir ces informations, nous avons choisi d’interroger un échantillon représentatif de 400 sujets ayant fait l’objet d’une sélection aléatoire basée sur des critères sociodémographiques. Le questionnaire, soumis par téléphone et en face-à-face, porte sur la notoriété spontanée et assistée ainsi que sur l'image des sportifs. Il a été élaboré avec l'aide d'un expert en marketing. Après analyses, nous pouvons classer les sportifs en termes de notoriété. Nous constatons également que certains sont perçus comme de véritables héros tandis que d'autres véhiculent plutôt une image négative. Ces informations s’avèrent cruciales pour les sportifs et leurs entraîneurs dans le sens où à un taux de notoriété élevée et une image positive s’associent plus aisément sponsors pendant la pratique et contrat de reconversion en fin de parcours. [less ▲]

Detailed reference viewed: 26 (4 ULg)
Full Text
Peer Reviewed
See detailComparaison du niveau d’estime de soi dans deux populations ayant des caractéristiques démographiques différentes : des arbitres et des non-arbitres
Van Hoye, Martin ULg; Cloes, Marc ULg

Poster (2014, July 03)

Si le sport forge le caractère, l’arbitrage devrait également responsabiliser les individus qui l’exercent. Aussi, on peut considérer que les arbitres pourraient développer une meilleure estime d’eux ... [more ▼]

Si le sport forge le caractère, l’arbitrage devrait également responsabiliser les individus qui l’exercent. Aussi, on peut considérer que les arbitres pourraient développer une meilleure estime d’eux-mêmes ? Dans cette recherche, nous avons tenté de vérifier cette hypothèse en analysant le niveau d’estime de soi de deux échantillons distincts : des arbitres de basket-ball (n=163) et des personnes n’ayant aucune expérience au niveau de l’arbitrage (n=163). L’instrument que nous avons utilisé est « l’Echelle de l’Estime de Soi » (EES). La moyenne générale au questionnaire est légèrement supérieure chez les arbitres (30,9 vs 30,5) mais il ne s’agit pas d’une différence significative (p=0,8372). L’ancienneté dans l’arbitrage ou l’âge des individus ne semblent pas être un facteur influençant l’estime de soi des arbitres. Il conviendrait de vérifier s’il en est de même dans les autres disciplines sportives que le basket-ball. [less ▲]

Detailed reference viewed: 28 (7 ULg)
Full Text
Peer Reviewed
See detailLa verbalisation: un outil performant permettant une amélioration de l'estime de soi? Analyse de cas chez des arbitres de basket-ball
Van Hoye, Martin ULg; Cloes, Marc ULg

Poster (2014, July 03)

L’estime de soi représente une dimension importante de notre personnalité, notamment chez les adolescents, souvent poussés par un important besoin de se montrer compétents en toute situation. Notre ... [more ▼]

L’estime de soi représente une dimension importante de notre personnalité, notamment chez les adolescents, souvent poussés par un important besoin de se montrer compétents en toute situation. Notre objectif consistait à améliorer l’estime de soi de jeunes arbitres de basket-ball (n=22) à l’aide d’une verbalisation d’après match. Nous avons comparé les résultats obtenus entre un groupe expérimental et un groupe contrôle. A l’issue de cette étude, nous n’avons observé aucun changement chez les sujets du groupe contrôle. Par ailleurs, une légère amélioration non-significative a été observée dans le groupe expérimental (+1,2/40). D’autre part, d’autres analyses nous permettent de conclure que l’utilisation de la verbalisation a bel et bien été bénéfique aux sujets expérimentaux. Nous pensons que ces arbitres réfléchiraient plus spontanément sur leur prestation. Ceci pourrait les aider à progresser, aussi bien en tant qu’arbitre qu’en tant qu’individu à proprement parler. Indirectement, cela les aiderait à augmenter leur estime de soi. [less ▲]

Detailed reference viewed: 21 (3 ULg)
Full Text
Peer Reviewed
See detailEvaluation des effets à court terme de l’intervention « Bouger plus » sur la pratique d’activité physique des seniors
Rompen, Jérôme ULg; Mouton, Alexandre ULg; Grimont, Pierre et al

Poster (2014, July 03)

Des outils basés sur un site internet sont efficaces pour promouvoir l’activité physique (AP) chez les seniors (Ammann et al., 2013). Cette étude avait pour but d’évaluer les effets de l’intervention « ... [more ▼]

Des outils basés sur un site internet sont efficaces pour promouvoir l’activité physique (AP) chez les seniors (Ammann et al., 2013). Cette étude avait pour but d’évaluer les effets de l’intervention « Bouger plus » sur la pratique d'AP de sujets de 50 ans et plus, au sein d’une commune. Quatre groupes ont reçu une intervention différente pendant trois mois : un site internet (I), un cours collectif (CC), une combinaison des deux (CCI) et pas d'intervention (CO). Des questionnaires ont permis d’évaluer les résultats. Ceux-ci montrent une évolution positive du stade de changement de comportement vis-à-vis de l’AP, au cours de l’intervention, pour les groupes I et CCI. De plus, le niveau de pratique est resté stable malgré la période hivernale pour les groupes CC et CCI alors qu’il a chuté pour le groupe CO. L’intervention a donc eu des effets positifs à court terme sur les comportements en matière d’AP, particulièrement quand le site internet et les cours collectifs étaient combinés. [less ▲]

Detailed reference viewed: 28 (15 ULg)
Full Text
Peer Reviewed
See detailEvaluation des effets à court terme de l’intervention « Bougerplus » sur les connaissances en matière d’activité physique des seniors
Mouton, Alexandre ULg; Rompen, Jérôme ULg; Cloes, Marc ULg

Poster (2014, July 03)

La littérature actuelle suggère qu’une meilleure connaissance en matière d’AP encouragerait à l’adoption d’un style de vie plus actif. L’objectif principal de cette étude était d’identifier les effets de ... [more ▼]

La littérature actuelle suggère qu’une meilleure connaissance en matière d’AP encouragerait à l’adoption d’un style de vie plus actif. L’objectif principal de cette étude était d’identifier les effets de trois interventions différentes sur la connaissance en matière d’AP chez les seniors d’une commune francophone belge. D’une durée de 3 mois, l’intervention se composait d’un site internet et d’un cours collectif. Quatre groupes de seniors provenant de la même commune ont été formés : contrôle (C), Internet (I), cours collectif (CC) et combiné (CCI). Des questionnaires ont été complétés par les participants avant l’intervention (T0), après l’intervention (T1) et après deux mois de suivi (T2). Une évolution significative des connaissances en matière d’AP a été constatée pour les groupe CCI et CC entre T0 et T2. L’intervention combinant un cours collectif ainsi qu’un outil Internet semble la plus efficace pour améliorer à court-terme les connaissances en matière d’AP chez les seniors. [less ▲]

Detailed reference viewed: 22 (8 ULg)
Full Text
Peer Reviewed
See detailAnalyse qualitative du fonctionnement du centre de formation d’une fédération sportive
Lacrosse, Zoé ULg; Martin, Valentine; Cloes, Marc ULg

Poster (2014, July 03)

Cette étude qualitative analyse le fonctionnement d’un centre de formation pour jeunes athlètes de haut niveau dont la finalité consiste à leur permettre de mener conjointement leurs études et leur ... [more ▼]

Cette étude qualitative analyse le fonctionnement d’un centre de formation pour jeunes athlètes de haut niveau dont la finalité consiste à leur permettre de mener conjointement leurs études et leur carrière sportives. Dans la perspective d’aider la structure à améliorer ce qui est mis en place, notre objectif consiste à décrire la situation actuelle. D’un point de vue pratique, nous avons interrogé les dirigeants (n=4) du centre, les sportifs (n=34), leurs parents (n=10), les coaches (n=3) ainsi que plusieurs intervenants externes (médecin, directeur d’école, etc. ; n = 3). Nous avons également réalisé un certain nombre d’observations informelles et collecté des questionnaires permettant de faire émerger le ressenti des joueurs quant à leur vie au sein du centre. Les résultats indiquent (a) un manque de suivi diététique et psychologique, (b) des relations relativement bonnes entre les acteurs sauf entre les joueurs et les éducateurs et, (c) la nécessité d’améliorer les infrastructures. [less ▲]

Detailed reference viewed: 20 (2 ULg)
Full Text
See detailA fresh look on the limit on light ALPs from SN1987A
Payez, Alexandre ULg; Evoli, Carmelo; Fischer, Tobias et al

Poster (2014, July 03)

We revisit the limit on very light axion-like particles from the absence of coincidental gamma rays with the neutrino burst from SN1987A. This is done using an updated supernova simulation, an updated ... [more ▼]

We revisit the limit on very light axion-like particles from the absence of coincidental gamma rays with the neutrino burst from SN1987A. This is done using an updated supernova simulation, an updated model for the magnetic field inside the Galaxy, and a Primakoff cross section which takes into account proton degeneracy. [less ▲]

Detailed reference viewed: 23 (12 ULg)
Full Text
Peer Reviewed
See detailMolecular adaptations in mouse skeletal muscle following eccentrically versus concentrically biased training
Hody, Stéphanie ULg; Lacrosse, Zoé ULg; Simonet, Arnaud et al

Poster (2014, July 02)

Introduction The molecular adaptations specifically induced by different muscle contraction types have only been partially elucidated. We previously demonstrated that eccentric contractions in human ... [more ▼]

Introduction The molecular adaptations specifically induced by different muscle contraction types have only been partially elucidated. We previously demonstrated that eccentric contractions in human quadriceps elicited proteome modifications that suggest a muscle fiber typology adaptation (Hody et al. 2011). We address this question in a more systematic way by examining the effects of different running modes on the mouse muscle proteome and the muscle fiber typology on the whole quadriceps. Methods Male adult mice (C57BL6) were randomly divided into downhill running (DHR, quadricipital eccentrically biased contractions), uphill running (UHR, quadricipital concentrically biased contractions) and untrained control (CONT) groups. Running groups performed five training sessions on an inclined treadmill for 75 to 135 min/day and the quadriceps muscles were dissected 96 hours after the last session. Muscle protein extracts of DHR and UHR groups (n=4/group) were subjected to a 2D-DIGE analysis coupled with mass spectrometry. The assessment of fiber type, size and number was performed on the rectus femoris of the three groups (n=6/group) using myosin heavy chain (MHC) immunofluorescence. Results In the proteomic analysis, eight spots identified as the fast MHC isoforms exhibited a lower abundance in DHR compared to UHR (p<0.05, t-test). In contrast, ATP synthase subunit a and tubulin ß were more expressed in DHR (p<0.05). Immunohistological analysis revealed a significant higher proportion of type I and IIa fibers for DHR compared to UHR or CONT groups (p<0.05, one-way ANOVA). Discussion Our data demonstrate that the eccentrically biased contractions in mice induced specific adaptations in protein expression as well as in muscle fiber type and size which may reflect a more oxidative muscle phenotype. The differences in stress placed on the muscle between both trainings may be responsible for some unique adaptations resulting from the eccentrically biased training. Eccentric training is known to protect skeletal muscles against exercise-induced muscle damage (EIMD) which may occur after intense eccentric contractions (Chen et al. 2010; Hody et al. 2011). It is also suggested that fast glycolytic muscle fibers are more vulnerable to EIMD than oxidative fibers (Lieber and Friden, 1988). Therefore, it would be interesting to investigate whether the molecular changes induced by an eccentrically biased training are involved in protection against EIMD. References Chen TC, Chen HL, Lin MJ, Wu CJ, Nosaka K. (2010). Med Sci Sports Exerc 42, 1004-1012. Hody S, Leprince P, Sergeant K, Renaut J, Croisier JL, Wang F, Rogister B. (2011). Med Sci Sports Exerc 43, 2281-2296. Lieber RL, Friden J. (1988). Acta Physiol Scand 133, 587-588. [less ▲]

Detailed reference viewed: 26 (4 ULg)
Full Text
See detailAre agricultural ecosystems important BVOC « exchangers »? Evidences from 2 measurement years on croplands at Lonzée (Belgium)
Bachy, Aurélie ULg; Aubinet, Marc ULg; Schoon, Niels et al

Poster (2014, July 01)

For the last decades, agricultural ecosystems have been a key biome for diverse socio-economical, environmental and climatic issues. And one of these climatic issues is just BVOC (Biogenic Volatile ... [more ▼]

For the last decades, agricultural ecosystems have been a key biome for diverse socio-economical, environmental and climatic issues. And one of these climatic issues is just BVOC (Biogenic Volatile Organic Compounds) emission from terrestrial ecosystems. Indeed, those compounds which are mostly emitted by plants play a great role in the atmospheric chemistry, thereby influencing the Earth surface radiative budget and the tropospheric air quality. However, so far, very few is known about BVOC exchange by crops, implying that huge uncertainties remain about qualifying, quantifying and determining sources/sinks and driving mechanisms of BVOC exchanges between croplands ecosystems and the atmosphere. We present here the first long term BVOC fluxes measurement study conducted on maize (2012) and winter wheat (2013), respectively the second and first most important worldwide crops (FAOSTAT). BVOC exchange was measured using the disjunct by mass scanning eddy covariance technique (+ PTR-MS, Ionicon) at the Lonzée Terrestrial Observatory (ICOS site) in Belgium. Main results are: (i) crops emit mainly methanol; (ii) BVOC fluxes from studied crops is lower than in literature, suggesting that agricultural ecosystems are poor BVOC exchangers; (iii) soil is a significant BVOC source. [less ▲]

Detailed reference viewed: 20 (5 ULg)
See detailX-ray emission from magnetic massive stars
Nazé, Yaël ULg; Petit, V.; Rindbrand, M. et al

Poster (2014, July 01)

Magnetically confined winds of early-type stars are expected to be sources of bright and hard X-rays. In an attempt to clarify the systematics of the observed X-ray properties, we have analyzed a large ... [more ▼]

Magnetically confined winds of early-type stars are expected to be sources of bright and hard X-rays. In an attempt to clarify the systematics of the observed X-ray properties, we have analyzed a large series of Chandra and XMM observations, corresponding to over 100 exposures of 60% of the known magnetic massive stars listed recently by Petit et al. (2013). We notably show that the X-ray luminosity is strongly correlated with mass-loss rate, in agreement with predictions of magnetically confined wind models. We also investigated the behavior of other X-ray properties (plasma temperature, absorption, variability), yielding additional constraints on models. This work not only advances our knowledge of the X-ray emission of massive stars, but also suggests new observational and theoretical avenues to further explore magnetically confined winds. [less ▲]

Detailed reference viewed: 10 (0 ULg)
See detailThe X-ray bright massive stars in Cyg OB2
Nazé, Yaël ULg; Cazorla, Constantin ULg; Rauw, Grégor ULg

Poster (2014, July 01)

As a complement to the results from the Cyg OB2 Chandra Legacy program, we present in this contribution the detailed analysis of the four X-ray bright massive stars dominating the cluster. Cyg OB2 #5, #8A ... [more ▼]

As a complement to the results from the Cyg OB2 Chandra Legacy program, we present in this contribution the detailed analysis of the four X-ray bright massive stars dominating the cluster. Cyg OB2 #5, #8A, and #9 are binary or multiple massive stars in the Cyg OB2 association displaying several peculiarities, such as bright X-ray emission and non-thermal radio emission. Our X-ray monitoring of these stars reveals the details of their behavior at high energies, which can be directly linked to wind-wind collisions (WWCs). In addition, the X-ray emission of Cyg OB2 #12, an evolved massive star, shows a long-term decrease, which could hint at the presence of a companion (with associated colliding winds) or indicate the return to quiescence of the system following a recent eruption. [less ▲]

Detailed reference viewed: 15 (7 ULg)
See detailSpatiotemporal distribution of last 500 yrs turbidites in the Western Gulf of Corinth, Greece: implications for the characterization of historical earthquakes
Beckers, Arnaud ULg; Hubert, Aurelia ULg; Beck, Christian et al

Poster (2014, July 01)

The Corinth rift is one of the fastest spreading rifts on Earth. 10 earthquakes of magnitude greater than 6 occurred during the last century. The question of seismic hazard is consequently particularly ... [more ▼]

The Corinth rift is one of the fastest spreading rifts on Earth. 10 earthquakes of magnitude greater than 6 occurred during the last century. The question of seismic hazard is consequently particularly relevant. Despite a long earthquake catalogue, estimations of earthquake hazard remain problematic because of the difficulty to associate each historical event to one of the many active faults mapped in the area. Consequently, combining seismology, history and paleoseismology in an interdisciplinary approach is here necessary and is the goal of the ANR-SISCOR project. In this framework, we investigated the offshore sediments in order to (1) better constraint the length of the active offshore faults, and (2) look for sedimentary signature of historical earthquakes. 600 km of high resolution seismic reflexion data have been acquired during two surveys and 12 short gravity cores have been retrieved. The latters are 0.5 to 1 m long, allowing us to analyze about 500 yrs of sedimentation. Two new faults potentially able to trigger M>5.5 earthquakes have been mapped in the northern part of the gulf based on seismic data. Sedimentary events (turbidites sensu lato) have been identified in some cores, essentially in the deep basin and in a 180m-deep sub-basin close to the northern coast. The comparison with the critically reviewed historical records shows that some of these events could have been triggered by historical earthquakes. The link between these potential earthquakes sedimentary signatures, historical events and active faults is discussed based on intensity maps and our new active fault map. [less ▲]

Detailed reference viewed: 20 (1 ULg)
Peer Reviewed
See detailHighly dispersed iron xerogel catalysts for p-nitrophenol degradation by photo-Fenton effects
Mahy, Julien ULg; Tasseroul, Ludivine ULg; Zubiaur, Anthony ULg et al

Poster (2014, July)

Since the beginning of the industrial era, the various human activities have increased steadily, leading to a rapid technological development and a high population growth. Thus, the expansion of the ... [more ▼]

Since the beginning of the industrial era, the various human activities have increased steadily, leading to a rapid technological development and a high population growth. Thus, the expansion of the industry has heavily polluted the atmosphere, soil and water with negative consequences for humans and environment [1]. To decrease this pollution, it exists various treatment methods: chemical, physical and biological [2,3]. Among all these methods, a recent way of treatment is the degradation of pollutants in soils or waters by Fenton and photo-Fenton reactions [3] which use H2O2, iron-based compounds and UV light. In this way, several Fe2O3/SiO2 xerogel catalysts were synthesized by cogelation method by hydrolysis and condensation of tetraethoxysilane (TEOS) and 3-(2-aminoethylamino)propyltrimethoxysilane (EDAS) which is able to form a chelate with iron ions [4]. Five samples were synthesized: four samples with different percentage of iron (0.5, 1, 1.5 and 2.5 theoretical wt% confirmed by ICP-AES measurements), and a sample of pure silica. TEM pictures, nitrogen adsorption-desorption and mercury porosimetry measurements have established that EDAS plays a role of nucleating agent of silica particles [5,6] and allows to anchor iron particles inside silica network [4]. Indeed, it results iron nanoparticles of diameter 1-1.5 nm encapsulated in silica particles with sizes of about 10-30 nm in diameter. The species of iron was determined by Mössbauer spectroscopy and only Fe3+ ions were observed in xerogel catalysts. Then, the Fenton and photo-Fenton effect of these catalysts were evaluated on the degradation of p-nitrophenol (PNP) in aqueous medium in different conditions. Results show that Fe2O3/SiO2 xerogels present a photo-Fenton effect with H2O2, reaching with a sample 99 % of degradation after 24 h. [1] M. A. Khan, A. M. Ghouri, Environmental pollution: its effects on life and its remedies, Journal of Arts, Science & Commerce (Vol. 2), 2011, pg 276-285. [2] M. S. Kuyukina , I. B. Ivshina, Biology of rhodococcus: chapter 9, Springer, 2010, pg 232-256. [3] J. J. Pignatello, E. Oliveros, A. MacKay, Advanced Oxidation Processes for Organic Contaminant Destruction Based on the Fenton Reaction and Related Chemistry, Critical Reviews in Environmental Science and Technology (Vol. 36), 2006, pg 1-84. [4] B. Heinrichs, L. Rebbouh, J.W. Geus, S. Lambert, H.C.L. Abbenhuis, F. Grandjean, G.J. Long, J.-P. Pirard, R.A. van Santen, Iron (III) species dispersed in porous silica through sol-gel chemistry, Journal of Non-Crystalline Solids (Vol. 354), 2008, pg 665-672. [5] S. Lambert, C. Alié, J.-P. Pirard, B. Heinrichs, Study of textural properties and nucleation phenomenon in Pd/SiO2 , Ag/SiO2 and Cu/SiO2 cogelled xerogel catalysts, Journal of Non-Crystalline Solids (Vol. 342), 2004, pg 70-81. [6] B. Heinrichs, S. Lambert , N. Job , J.-P. Pirard, in "Catalyst Preparation: Science and Engineering, J. R. Regalbuto (Ed.)", CRC Press, Taylor & Francis Group, Boca Raton, 2007, p. 163-208. [less ▲]

Detailed reference viewed: 87 (24 ULg)
Peer Reviewed
See detailMetacognition and school learning: Use of the DELV program in primary school
Nobile, Debora ULg; Frenkel, Stéphanie ULg

Poster (2014, July)

In the framework of self-regulated learning theories, the DELV (“Understanding one’s own learning”) is a 165-page metacognitive intervention program developed by Büchel & Büchel (1995, 1997, 2009, 2010 ... [more ▼]

In the framework of self-regulated learning theories, the DELV (“Understanding one’s own learning”) is a 165-page metacognitive intervention program developed by Büchel & Büchel (1995, 1997, 2009, 2010, 2011). It includes 8 types of decontextualized exercises which notably allow to develop the learner’s metacognitive knowledge and skills (for more details, see Büchel, 2013). They also make it possible to work on cognitive and psycho-affective aspects. Transfer can thus be better developed. This tool is really useful (for more details, see Berger & Büchel, 2013) and, in our opinion, still not sufficiently known. Our main purpose is to present (a) its objectives, (b) the variables worked on (cognitive, metacognitive and psycho-affective), (c) possible uses in a school context within classes (e.g., the “sandwich method”) and (d) the outcome we can expect. References - Berger, J.-L., & Büchel, F.P. (2013), L’autorégulation de l’apprentissage: Perspectives théoriques et applications. Nice, France: Les Editions Ovadia. - - Büchel, F.P. (2013). Le programme DELV – Comprendre son propre apprentissage. Evaluation scientifique auprès d’enfants et d’adolescents sans ou avec difficultés d’apprentissage. In J.-L. Berger & F.P. Büchel (Eds.), L’autorégulation de l’apprentissage: Perspectives théoriques et applications (pp. 293-336). Nice, France: Les Editions Ovadia. - Büchel, F.P. & Büchel, P. (1995). Découvrez vos capacités, rEalisez vos possibilités, pLanifiez votre démarche, soyez créatiFs. Le programme DELF. Russin, Switzerland: Centre d’éducation cognitive. - Büchel, F.P., & Büchel, P. (1997). DELV. Das Eigene Lernen Verstehen. Ein Programm zur Förderung des Lernens und Denkens für Jugendliche und Erwachsene. Aarau, Switzerland: Sauerländer. - Büchel, F.P. & Büchel, P. (2009). DELV. Das Eigene Lernen Verstehen. Ein Programm zur Förderung des Lernens für Jugendliche und Erwachsene (3. vollständig überarbeitete Auflage). Berne, Switzerland: h.e.p. Verlag. - Büchel, F.P. & Büchel, P. (2010). DELV. Das Eigene Lernen Verstehen. Ein Programm zur Förderung des Lernens für Jugendliche und Erwachsene (4. überarbeitete Auflage). Berne, Switzerland: h.e.p. Verlag. - Büchel, F.P. & Büchel, P. (2011). DELV. Comprendre son propre apprentissage. Tegna, Switzerland: Centre d’éducation cognitive. [less ▲]

Detailed reference viewed: 28 (8 ULg)
Peer Reviewed
See detailHigh throughput sequencing analysis reveals genetic variability and selection pressure in different murine norovirus genomic regions during in vitro replication
Mauroy, Axel ULg; Taminiau, Bernard ULg; Nezer, Carine et al

Poster (2014, July)

Murine norovirus (MuNoV), a single stranded positive sense RNA virus belonging to the Caliciviridae family, is considered as a representative model for human norovirus infections, one of the most ... [more ▼]

Murine norovirus (MuNoV), a single stranded positive sense RNA virus belonging to the Caliciviridae family, is considered as a representative model for human norovirus infections, one of the most important etiological cause of both epidemic and sporadic gastroenteritis cases worldwide. Four open reading frames are described into its genome: ORF1 codes the non-structural (NS) proteins, including the viral RNA dependent RNA polymerase (RdRp); ORF2 codes the single capsid protein (VP1), wherein two domains are present: a relatively conserved domain (“shell”) and a more variable domain (“protruding”); ORF3 codes a minor structural protein; and ORF4, currently only found in viruses genetically related to MuNoV codes a virulence factor. In this study, we demonstrated by high throughput sequencing that, during serial passages of MuNoV in cell culture, the substitution rates, estimated by Bayesian inferences, did not significantly differ across the five targeted genomic regions except one. These rates were similar in four genomic regions encompassing partial non-structural 1-2 protein (NS1-2)-, NS5-, NS6-, NS7 (RdRp)- and VP1-coding sequences (coding the conserved part of the protein also including the ORF4 region). In the partial minor structural protein-coding region, this substitution rate was however estimated to be at least one log higher when expressed as substitution/site/day. The precise localisation of the detected nucleotide point mutations (substitution, deletion and insertion) were reported as well as the quantitative increase or decrease of the sequences harbouring them along ten cell culture passages. The non-silent amino acid mutations were also depicted in 3D models for four out of the five studied regions. These results have important implications for different norovirus research fields, especially in terms of diagnosis, classification methodology and genetic evolution. [less ▲]

Detailed reference viewed: 20 (0 ULg)
Full Text
See detailSynthesis of Pt/Carbon Xerogel Electrocatalysts for PEM Fuel Cells by the Multiple SEA Method
Zubiaur, Anthony ULg; Chatenet, Marian; Maillard, Frédéric et al

Poster (2014, July)

Detailed reference viewed: 23 (1 ULg)
See detailA parent-implemented language intervention in lower socioeconomic status populations
Martinez Perez, Trecy ULg; Leclercq, Anne-Lise ULg; Mulquet, Amandine et al

Poster (2014, July)

Detailed reference viewed: 18 (2 ULg)
Full Text
Peer Reviewed
See detailValidation of a new automatic drowsiness quantification system for drivers
Wertz, Jérôme ULg; François, Clémentine ULg; Verly, Jacques ULg

Poster (2014, July)

Drowsiness is a major cause of various types of accidents, and particularly of driving accidents. Scientific studies report that drowsiness would be responsible for 20 to 30% of driving accidents ... [more ▼]

Drowsiness is a major cause of various types of accidents, and particularly of driving accidents. Scientific studies report that drowsiness would be responsible for 20 to 30% of driving accidents. Drowsiness can result from, among others, sleep deprivation, sleep disorders, alcohol, some medications, or performing a monotonous task. While all persons are likely to be drowsy at some point during the day, some persons are more prone than others to being drowsy at almost any time of the day; e.g. 6 to 11% of the population suffers from severe chronic excessive daytime sleepiness. Three main classes of methods can be used to characterize the level of drowsiness of a driver without disturbing him. These classes are respectively related to vehicle behavior (e.g. via lateral movements), driver behavior (e.g. via steering wheel movements), and driver physiological state (e.g. via eye movements). Since drowsiness is a physiological state, it seems particularly meaningful to use physiology-based methods to characterize it. Among these, the most significant ones rely on polysomnography and/or oculography. Polysomnography is viewed by some practitioners as the reference in the domain, but it is very sensitive to artifacts, and it is not very practical for use while driving. Ocular parameters are recognized to be good and reliable physiological indicators of drowsiness, and, thus, oculography seems to be the most sensible way to characterize drowsiness in practice. We have thus developed an experimental, fully automatic drowsiness monitoring system (software/algorithms) based on the physiological state of a person. This system uses ocular parameters extracted from images of the eye (i.e. photooculography) to determine a level of drowsiness on a continuous numerical scale from 0 to 10, with 0 corresponding to "very awake" (or "very vigilant") and 10 to "very drowsy". The ultimate goal of this system is to prevent drowsiness-related accidents for driving and other applications. The reported study shows that our system exhibits promising capability for road safety. Fourteen healthy volunteers (7 M, 7 F, mean age 23.7, range 21-33 years) participated in an experiment in a driving simulator, where they were asked to perform three driving sessions/runs (two of 45 minutes and one of 60 minutes) in different sleep-deprivation conditions (with up to 28 hours of complete sleep deprivation). During each session, we recorded both a high frame rate video of one eye and a set of driving parameters. Subsequently, for each successive minute in the session, we used our algorithms to extract ocular parameters from the video images and to produce a level of drowsiness, and we computed the standard deviation of lateral position (SDLP) from the driving parameters. The results show (1) that the (computed) SDLP increases when the (computed) level of drowsiness increases, and (2) that the level of drowsiness increases when the level of sleep deprivation increases. These results indicate that our algorithms for producing a level of drowsiness work in a meaningful way. The experiment protocol was approved by the Ethics Committee of our university. [less ▲]

Detailed reference viewed: 69 (15 ULg)
Full Text
Peer Reviewed
See detailMolecular detection of six high importance endosymbiotic bacteria in Belgian wild-caught mosquitoes
Raharimalala, Fara Nantenaina ULg; Boukraa, Slimane ULg; Bawin, Thomas ULg et al

Poster (2014, July)

Introduction Several disease vectors presented a resistance to various pesticides currently used. One of an alternative solution was to use endosymbiotic bacteria because their probably interactive ... [more ▼]

Introduction Several disease vectors presented a resistance to various pesticides currently used. One of an alternative solution was to use endosymbiotic bacteria because their probably interactive effects with their host. According to the introduction risks of mosquito born disease and their dispersion, we propose to investigate the prevalence of six endosymbiontic bacteria in wild-caught Culicidae in Belgium. Methods Eleven species of Belgian fields mosquitoes (Culex pipiens s.l., Cx. torrentium, Cx. hortensis, Anopheles claviger, An. maculipennis s.l., An. plumbeus, Culiseta annulata, Ochlerotatus geniculatus, Oc. dorsalis, Aedes albopictus and Coquillettidia richiardii) were used for the screening of six genera endosymbiotic bacteria (Wolbachia sp., Commamonas sp., Delftia sp., Pseudomonas sp., Acinetobacter sp. and Asaia sp.) according to their possible impact in mosquito biology. PCR was done for the screening and positives bands were sequenced and deposited in GenBank. Results Total of 144 larvae and 32 adults were used. Wolbachia, Pseudomonas, Acinetobacter and Asaia were found in mosquitoes with different proportions, according to stages (adults, larvae) with a predominance of Pseudomonas in all species, as far as Acinetobacter and Asaia also have a high prevalence. Commamonas and Delftia were absent from all species tested, either in larvae and in adults. Discussion Choice of endosymbiotic bacteria studied here was allowing of their importance in literature. For Pseudomonas, it showed that this bacteria could produced ovipositon attractants for mosquito. Acinetobacter was suggested efficient in transmission and maintenance within host populations. Asaia was capable of efficiently crossing body barriers and colonizing different organs. Wolbachia was currently the most studied bacteria which plays an important role in the genetic manipulation of the host. Present advances in understanding the mosquito–microbiota relationships may have a great impact in a better understanding of some traits of mosquito biology and in the development of innovative mosquito-borne disease-control strategies. [less ▲]

Detailed reference viewed: 34 (6 ULg)
Full Text
Peer Reviewed
See detailAre you sure this was your own idea?
Beaufort, Aline ULg; Brédart, Serge ULg; Dehon, Hedwige ULg

Poster (2014, July)

Detailed reference viewed: 9 (3 ULg)
Peer Reviewed
See detailSentence repetition task as a powerful diagnostic tool in French children with SLI
Leclercq, Anne-Lise ULg

Poster (2014, July)

Sentence repetition is considered as a psycholinguistic marker of specific language impairment (SLI) (i.e., Redmond et al., 2011). However, little is known about specificity and sensitivity for most ... [more ▼]

Sentence repetition is considered as a psycholinguistic marker of specific language impairment (SLI) (i.e., Redmond et al., 2011). However, little is known about specificity and sensitivity for most language tests, especially in French (Thordardottir et al., 2011). This study aims at assessing the specificity and sensitivity of a sentence repetition task frequently used in clinical evaluations (Chevrie-Muller et al., 2010). This task could be especially interesting because clinicians can compute separate linguistic scores depending on the answers produced by the children, enabling them to get a glimpse of the areas of language difficulties in these children. Fourty-four school-age children with SLI, and 34 age-and-IQ-matched controls participated in this study. Children with SLI were diagnosed by certified speech-language pathologists and attained specific language classes in special needs schools from at least one year. Moreover, they scored more than -1.25 SD below expected normative performance in at least 2 language areas on other standardised tests used in previous studies including French children with SLI. Results show that both sensitivity and specificity of general scores were high (over 80%) at three cut-off points widely used in clinical practice: -1SD, -1.25 SD, -2 SD. Moreover, an exploratory factorial analysis indicates that two distinct factors can be dissociated in children productions: a morphosyntactic factor and a lexico-semantic factor, together explaining 96.48% of the variance in production scores. These results reveal that the sentence repetition task is a powerful diagnostic tool in French children with SLI. [less ▲]

Detailed reference viewed: 54 (1 ULg)
Full Text
Peer Reviewed
See detail3D analysis and determination of stride parameters for different type of foot strike in running
Deflandre, Dorian ULg; Bury, Thierry ULg; Schwartz, Cédric ULg et al

Poster (2014, July)

The purpose of the study was to compare methods for the determination of foot strike and toe off for runners with different foot strike patterns. A 3D optoelectronic system usually used in motion ... [more ▼]

The purpose of the study was to compare methods for the determination of foot strike and toe off for runners with different foot strike patterns. A 3D optoelectronic system usually used in motion laboratories was compared with tools commonly used on the field: an optical based detection system (OptoGait) and an accelerometer based system (Myotest). [less ▲]

Detailed reference viewed: 54 (8 ULg)
See detailBiological indicators of soil quality over landscape spatial scales: a case study in Southern Belgium
Krüger, Inken ULg; Chartin, Caroline; Van Wesemael, Bas et al

Poster (2014, July)

Biological indicators are organisms or biological processes whose values give quantitative information on the capacity of a soil to function. Their fast dynamic allows to detect changes on short ... [more ▼]

Biological indicators are organisms or biological processes whose values give quantitative information on the capacity of a soil to function. Their fast dynamic allows to detect changes on short timescales. Five biological indicators (basal respiration, nitrogen mineralisation, microbial carbon and nitrogen, earthworm abundance and biomass, functional microbial diversity) as well as two ecophysiological indices (microbial quotient and metabolic quotient) were tested for their power to characterize the biological soil quality on a landscape level at 60 sites in two South-Belgian landscape units were investigated. All biological indicators differed significantly between the two landscape units showing the biological indicators to be discriminatory on a landscape level. Within each landscape unit, no relationships between biological indicators were found, underlining the need to measure multiple biological indicators. The results represent the first data for a South-Belgian monitoring network of biological soil quality. [less ▲]

Detailed reference viewed: 44 (5 ULg)
Full Text
See detailDroplet synchronization in multiple interconnected parallel channels
Van Loo, Stéphanie ULg; Stoukatch, Serguei ULg; Gilet, Tristan ULg

Poster (2014, July)

In droplet microfluidics, the pairing of droplets in parallel channels is sometimes required, e.g. to control their encounter and to promote their coalescence. Prakash and Gershenfeld [1] showed that ... [more ▼]

In droplet microfluidics, the pairing of droplets in parallel channels is sometimes required, e.g. to control their encounter and to promote their coalescence. Prakash and Gershenfeld [1] showed that passive synchronization could be achieved with bubbles in a ladder-like channel network. Bubbles flow in the rails and induce recirculation in the interconnecting rungs, which supposedly provides the feedback and subsequent synchronization. Ahn et al. recently extended this study to trains of droplets in flow-rate-driven conditions [2]. We here present an extensive experimental and theoretical investigation of droplets synchonization in multiple parallel channels. Droplets are produced with independent flow-focusing structures. Several experimental conditions are tested, including several geometries (and subsequent flow resistance) and inlet conditions (pressure-driven vs. flow-rate-driven). An extension to three rails is also considered. The microfluidic chips are designed with the help of a lumped-element model in which droplets are driven by the flows. [1] M. Prakash and N. Gershenfeld, Science 2007, 315, 832-835 [2] Ahn et al., Lab-on-a-chip, 2011, 11, 3956-3962 [less ▲]

Detailed reference viewed: 30 (5 ULg)
Full Text
See detailThe Amik Lake in Southern Turkey over the last 4000 years, a new paleoseismological record of ruptures along the Northern Dead Sea Fault
Hubert, Aurelia ULg; El Ouahabi, Meriam ULg; Lebeau, Hèlène et al

Poster (2014, June 30)

The study focuses on the sedimentary record of the Amik Lake occupying the central part of a pull-apart basin. The Basin is crossed by The Dead Sea Fault (DSF), a major neotectonic structure in the Middle ... [more ▼]

The study focuses on the sedimentary record of the Amik Lake occupying the central part of a pull-apart basin. The Basin is crossed by The Dead Sea Fault (DSF), a major neotectonic structure in the Middle East extending from the Red Sea in the south to the East Anatolian Fault Zone in the north. Around the Amik Basin, continuous human occupation is attested since 6000-7000 BC. Indeed the low-lying Amuq plain is covered by tell settlements first explored by Robert Braidwood in the 1930s. Our objective in this presentation is to look at major paleo-environmental changes recorded in the Amik Lake over the last 4000 years and in particular its potential paleoseimic sedimentary record. The lake has been drained and progressively dried up since the mid-50s so that it is not watered during the summer season and constitutes a unique opportunity to collect sediment records. Sediments were collected at 1 cm to 2 cm intervals in a trench and in cores up to a depth of 5 meters in the clay deposits. A diverse array of complementary methods is applied to study the records: magnetic susceptibility, grain size, organic matter and inorganic carbon (L.O.I), XRD mineralogy, XRF geochemistry, carbon geochemistry and clay mineralogy. The age of the record is constrained combining radionuclide and radiocarbon dating. The sedimentary record shows large earthquake related structural disturbances and smaller siliciclastic sedimentary events. The siliciclastic input would be related to enhanced detritical sedimentation related to earthquake shaking. The latter is further investigated looking at intensities and shake maps related to the last 19th century M>7 earthquakes in the area and landslide prone area in the lake catchment. [less ▲]

Detailed reference viewed: 49 (6 ULg)
Full Text
See detailPLANTIGRADY DUE TO A LOCALIZED MYOPATHY IN TWO NEWBORN BELGIAN BLUE CALVES
Genart, Marie; Evrard, Laurence ULg; Garcia da Fonseca et al

Poster (2014, June 26)

Detailed reference viewed: 20 (2 ULg)
Full Text
See detailL’ancrage dans les herbiers à Posidonia oceanica. Conséquences chimiques de la destruction mécanique ?
Abadie, Arnaud ULg

Poster (2014, June 26)

La plante marine endémique de Méditerranée Posidonia oceanica, ou posidonie, forme en Corse des herbiers colonisant les substrats depuis la surface jusqu’à 40 m de profondeur. Ces herbiers constituent un ... [more ▼]

La plante marine endémique de Méditerranée Posidonia oceanica, ou posidonie, forme en Corse des herbiers colonisant les substrats depuis la surface jusqu’à 40 m de profondeur. Ces herbiers constituent un véritable écosystème, l’un des plus riches en espèces de Méditerranée. Ils jouent un rôle écologique essentiel en oxygénant le milieu grâce à la photosynthèse et en séquestrant du CO2 au sein de leur complexe racinaire dans le sédiment (ou "matte"). Ces activités métaboliques entraînent une importante modification des conditions biogéochimiques du substrat qui favorisent le maintien de la plante. Les herbiers ont également une grande importance économique servant de nurserie pour de nombreuses espèces exploitées par la pêche commerciale et récréative. Les herbiers de posidonie se développant dans les zones côtières, ils sont impactés par les activités anthropiques (urbanisation, pollution, fermes aquacoles, ancrage) qui peuvent entraîner d’importantes destructions et des régressions de leur zone de recouvrement. L’ancrage intensif dans les herbiers à faible profondeur y génère des trouées, ou "intermattes". Les destructions engendrées par les navires de petite taille (< 10 m) peuvent, dans certaines conditions, être recolonisées par la posidonie. Cependant, dans la plupart des zones d’ancrage intensif en Corse, les intermattes ne sont pas recolonisées et leur surface peut souvent augmenter. De plus, certaines zones sont soumises à l’ancrage intensif de navires de plaisance de grande taille (> 20m), susceptibles de générer des intermattes d’une étendue plus importante. Ce phénomène d’expansion ne peut s’expliquer par la seule destruction mécanique. L’arrachage de la strate foliaire de la posidonie par les ancres semble entraîner de profondes modifications physiques et chimiques dans le sédiment. La photosynthèse via les feuilles étant ainsi altérée, il n’y a plus d’oxygénation du sédiment via les racines de la posidonie et un milieu anoxique défavorable à son développement paraît se créer. Des composés toxiques pour la plante, tel que le sulfure d’hydrogène (H2S), pourraient alors s’introduire dans ses tissues entraînant une limitation de son développement, voire sa disparition menant ainsi à une amplification des dégâts mécaniques de l’ancrage. Des observations seront réalisées tout autour de la Corse et notamment dans la Baie de Calvi, site atelier de la Méditerranée, qui a été définie pour mener la phase d’expérimentation. Les données récoltées à l’issue de ces travaux de recherches, réalisés dans le cadre d’un doctorat en entreprise (bourse CIFRE), seront compilées afin de mettre au point de nouveaux outils d’analyse de l’impact de l’ancrage. [less ▲]

Detailed reference viewed: 48 (6 ULg)
Full Text
Peer Reviewed
See detailProbing the conformational changes during desolvation of ions using orthogonal mobility methods (CE-IM MS)
Far, Johann ULg; Kune, Christopher ULg; Delvaux, Cédric ULg et al

Poster (2014, June 24)

Routine analyses using Mass Spectrometry (MS) detection became a very popular due to the low limit of detection, great sensitivity, selectivity and specificity. Moreover MS enables structural elucidation ... [more ▼]

Routine analyses using Mass Spectrometry (MS) detection became a very popular due to the low limit of detection, great sensitivity, selectivity and specificity. Moreover MS enables structural elucidation and physical (or physicochemical) properties determination using low amount of not especially pure samples. One of these properties is substantially the stoichiometry determination of non-covalent complexes such as Ligand receptor systems (e.g. DNA-drugs, Hormones/drugs-receptor, quaternary structure arrangement of polypeptides, …). MS determination in native condition (Native MS) of this stoichiometry allows large scale screening of potential drugs candidates in pharmaceutical context. The addition of Ion-Mobility (IM) to mass spectrometry (IM-MS) with computational chemistry support allows the structural conformation monitoring (as Collisional Cross Section or CCS) and the elucidation of interactions of the non-covalent complexes. Nonetheless such determinations suppose/assume that desolvation steps and gas phase transfer during MS detection do not modify the tridimensional structure of these systems or the magnitude order of the involved interactions (dipole-dipole, dipole-ion, ion-ion, hydrophobic interactions). Further studies (Circular Dichroism, Nuclear Magnetic resonance, UV-Visible spectra …) are generally required to confirm the MS data but there are unfortunately time consuming. This project proposes the coupling of Capillary Electrophoresis (CE) to IM-MS in order to obtain in one injection the quantitative and qualitative data of non-covalent complexes and the monitoring of tridimensional conformation modification between the liquid and gas phase. Indeed CE allows the determination of numerous physicochemical properties (dissociation constant, pK values, hydrodynamic radius determination …). The structural data (i.e. hydrodynamic radius and CCS) are compared to the data obtained by IM-MS as a proof of concept using tryptic digest of Bovine Serum Albumine (BSA). [less ▲]

Detailed reference viewed: 32 (7 ULg)
Full Text
Peer Reviewed
See detailGeneration of artificial magnetic fields using dipole-dipole interactions
Cesa, Alexandre ULg; Martin, John ULg

Poster (2014, June 23)

In 1996, Lloyd [1] showed that the dynamics of complex many-body quantum systems can be efficiently simulated by quantum computers, an idea first put forward by Manin [2] and further developed by Feynman ... [more ▼]

In 1996, Lloyd [1] showed that the dynamics of complex many-body quantum systems can be efficiently simulated by quantum computers, an idea first put forward by Manin [2] and further developed by Feynman [3]. Although the first quantum computers of a few qubits have been realised experimentally [4, 5], the advent of scalable quantum computers might take another few decades. An alternative tool in the context of simulation is a highly controllable quantum system able to mimic the dynamics of other complex quantum systems, known as an analog quantum simulator. Cold neutral atoms and trapped ions have been shown to be versatile quantum simulators [6, 7] thanks to their high flexibility, controllability, and scalability. They permit one to study a wide range of problems arising from atomic physics, relativistic quantum physics, or cosmology [8]. Since neutral atoms do not carry any net charge, the simulation of electric and magnetic condensed matter phenomena, such as the spin Hall effect, seems out of reach. To overcome this apparent difficulty, the idea has been proposed to create artificial electromagnetic potentials for neutral atoms based on atom-light interaction [9– 12]. These artificial potentials act on neutral atoms as real electromagnetic potentials act on charged particles. Many works on artificial gauge potentials induced by atom-light interactions adopt a single-particle approach [12]. The predicted potentials are then supposed to be valid for a system of weakly interacting atoms. So far, the consequences of atom-atom interactions on the generation of artificial gauge fields has little been studied. The aim of this work is to study the artificial gauge fields arising from the interaction of two Rydberg atoms driven by a common laser field [13]. In this situation, we show that the combined atom-atom and atom-field interactions give rise to nonuniform, artificial gauge potentials. We identify the mechanism responsible for the emergence of these gauge potentials. Analytical expressions for the latter indicate that the strongest artificial magnetic fields are reached in the regime intermediate between the dipole blockade regime and the regime in which the atoms are sufficiently far apart such that atom-light interaction dominates over atom-atom interactions. We discuss the differences and similarities of artificial gauge fields originating from resonant dipole-dipole [14] and van der Waals [15] interactions. We also give an estimation of experimentally attainable artificial magnetic fields resulting from this mechanism and we discuss their detection through the deflection of the atomic motion. [1] S. Lloyd, Science 273, 1073 (1996). [2] Yu. I. Manin, Computable and uncomputable, Sovetskoye Radio, Moscow, 1980. [3] R. P. Feynman, Int. J. Theor. Phys. 21, 467 (1982). [4] L. DiCarlo, J. M. Chow, J. M. Gambetta, Lev S. Bishop, B. R. Johnson, D. I. Schuster, J. Majer, A. Blais, L. Frunzio, S. M. Girvin, and R. J. Schoelkopf, Nature 460, 240 (2009). [5] N. Xu, J. Zhu, D. Lu, X. Zhou, X. Peng, and J. Du, Phys. Rev. Lett. 108, 130501 (2012). [6] I. Buluta and F. Nori, Science 326, 108 (2009). [7] I. Bloch, J. Dalibard and S. Nascimbéne, Nature Physics 8, 267 (2012). [8] R. Blatt and C. F. Roos, Nature Physics 8, 277 (2012). [9] G. Juzeliunas and P. Öhberg, Phys. Rev. Lett. 93, 033602 (2004). [10] G. Juzeliunas, P. Öhberg, J. Ruseckas, and A. Klein, Phys. Rev. A 71, 053614 (2005). [11] G. Juzeliunas, J. Ruseckas, P. Öhberg, and M. Fleischhauer, Phys. Rev. A 73, 025602 (2006). [12] J. Dalibard, F. Gerbier, G. Juzeliu ̄nas, and P. Öhberg, Rev. Mod. Phys. 83, 1523 (2011). [13] A. Cesa and J. Martin, Phys. Rev. A 88,062703 (2013). [14] A. Gaëtan, Y. Miroshnychenko, T. Wilk, A. Chotia, M. Viteau, D. Comparat, P. Pillet, A. Browaeys, and P. Grangier, Nature Physics 5, 115 (2009). [15] L. Béguin, A. Vernier, R. Chicireanu, T. Lahaye, and A. Browaeys, Phys. Rev. Lett. 110, 263201 (2013). [less ▲]

Detailed reference viewed: 41 (5 ULg)
Peer Reviewed
See detailSymmetric N-qubit anticoherent states
Baguette, Dorian ULg; Bastin, Thierry ULg; Martin, John ULg

Poster (2014, June 23)

Entanglement is among the key features of quantum mechanics. In the last decade, a lot of efforts has been made to quantify the amount of entanglement of various multipartite states, either pure or mixed ... [more ▼]

Entanglement is among the key features of quantum mechanics. In the last decade, a lot of efforts has been made to quantify the amount of entanglement of various multipartite states, either pure or mixed. In particular, the search for maximally entangled states (states maximizing certain measures of entanglement) has focused a great deal of attention, see e.g. Refs. [1–4]. In this work, we present a comprehensive study of maximally entangled symmetric N-qubit states with respect to the definition of Gisin [1]. According to this definition, a state is maximally entangled if all its one-qubit reduced density matrices are maximally mixed. These states maximize various entanglement measures, such as von Neumann and Meyer-Wallach entropies [5]. They are unique up to local unitaries within the class of states interconvertible under stochastic local operations and classical communication (SLOCC) [3]. Besides, they are conjectured to be maximally entangled with respect to the Negative Partial Transpose measure of entanglement [6]. As appreciated by B. Kraus, they play an important role in the determination of the local unitary equivalence of multiqubit states [7]. Moreover, they are maximally fragile (in the sense that they are the states which are the most sensitive to noise) and therefore have been proposed as ideal candidates for ultrasensitive sensors [1]. We provide general conditions for a symmetric state with an arbitrary number of qubits to be maximally entangled and identify families of SLOCC classes which do not contain any such states. We also compute various measure of entanglement associated with those states in order to characterize them further and find all maximally entangled states up to 4 qubits. We finally prove that maximally entangled states coincide with anticoherent states of order 1. According to the definition of Ref. [8], a symmetric state of N qubits is anticoherent to order t iff 〈(S·n)k〉 is independent of n for k = 1, . . . , t where n is a tridimensional unit vector and S is the collective spin operator associated to the N-qubit system. [1] N. Gisin, H. Bechmann-Pasquinucci, Phys. Lett. A 246 (1998). [2] A. Higuchi, A. Sudbery, Phys. Lett. A, 272, 213 (2000). [3] F. Verstraete, J. Dehaene, B. De Moor, Phys. Rev. A 68, 012103 (2003). [4] J. Martin, O. Giraud, P. A. Braun, D. Braun and T. Bastin, Phys. Rev. A 81, 062347 (2010). [5] D. A. Meyer, N. R. Wallach, J. Math. Phys. 43, 4273 (2002). [6] I. D. K. Brown, S. Stepney, A. Sudbery, and S. L. Braunstein, J. Phys. A 38, 1119 (2005). [7] B. Kraus, Phys. Rev. Lett. 104, 020504 (2010). [8] J. Zimba, EJTP 3, 10 (2006). [less ▲]

Detailed reference viewed: 36 (7 ULg)
Full Text
Peer Reviewed
See detailEvaluation of SFC interest for the determination of cholecalciferol and its impurities un pharmaceuticals
Andri, Bertyl ULg; Dispas, Amandine ULg; Klinkenberg, Régis et al

Poster (2014, June 23)

Detailed reference viewed: 22 (0 ULg)
Full Text
See detailChemical abundances of fast-rotating OB stars
Cazorla, Constantin ULg; Morel, Thierry ULg; Nazé, Yaël ULg et al

Poster (2014, June 23)

Fast rotation in massive stars is predicted to induce mixing in their interior, but recent observations have challenged this concept by revealing a population of fast-rotating stars with normal nitrogen ... [more ▼]

Fast rotation in massive stars is predicted to induce mixing in their interior, but recent observations have challenged this concept by revealing a population of fast-rotating stars with normal nitrogen abundances at their surface (Hunter et al. 2009, A&A, 496, 841; Brott et al. 2011, A&A, 530, A116, but see Maeder et al. 2014, A&A, 565, A39). However, as the binary fraction of these stars is unknown, the importance of mass-transfer processes cannot be quantified. As a result, no definitive statements about the ability of single-star evolutionary models including rotation to reproduce these observations can be made. Our work combines for the first time a detailed surface abundance analysis with a radial-velocity monitoring for a sample of bright, fast-rotating Galactic OB stars to put strong constraints on stellar evolutionary and interior models. [less ▲]

Detailed reference viewed: 11 (6 ULg)
Peer Reviewed
See detailAlteration of decoherence-free states caused by dipole-dipole interactions
Damanet, François ULg; Martin, John ULg

Poster (2014, June 23)

Decoherence, known as the consequence of the coupling of any quantum system to its environment, causes information loss in the system and represents a major problem in the physical realization of quantum ... [more ▼]

Decoherence, known as the consequence of the coupling of any quantum system to its environment, causes information loss in the system and represents a major problem in the physical realization of quantum computers [1]. Decoherence-Free States (DFS) are considered as a possible solution to this problem. A set of trapped cold atoms placed in a DFS state will be immune against decoherence due to spontaneous emission. However, because of dipole-dipole interactions between atoms, induced dephasing effects are likely to destroy the coherence and drive the system out of its DFS [1, 2]. In this work, we study numerically the dynamics of a set of two-level atoms initially in a DFS with respect to dissipative processes by solving the master equation including both dissipative dynamics and dipole dipole interactions. We fo- cus our attention on the infuence of dipolar coupling on the radiated energy rate and coherence of the system as in [3]. In particular, by averaging over many realizations of close randomly distributed atomic positions, we show the formation of a superradiant-like pulse and we study its properties as a function of the dipolar coupling strength. [1] D. A. Lidar & K. B. Whaley, Lectures Notes in Phys., Vol. 622, p83-120, Springer (2003). [2] M. Gross & S. Haroche, Physics reports 93, 301-396 (1982). [3] W. Feng, Y. Li & S-Y. Zhu, Phys. Rev. A 88, 033856 (2013). [less ▲]

Detailed reference viewed: 16 (1 ULg)
Full Text
Peer Reviewed
See detailContribution of ion mobility for structural analysis and analytical chemistry: Use of selective IMS shift reagents (SSR)
Kune, Christopher ULg; Far, Johann ULg; Delvaux, Cédric ULg et al

Poster (2014, June 19)

Ion mobility is a gas phase separation technique based on the Collisional Cross Section (CCS) of ions. It discriminates isobaric and isomeric ions provided their CCS difference is larger than the ... [more ▼]

Ion mobility is a gas phase separation technique based on the Collisional Cross Section (CCS) of ions. It discriminates isobaric and isomeric ions provided their CCS difference is larger than the instrumental resolution. This work proposes a new method to overcome this limitation while providing additional structural information. A Selective Shift Reagent (SSR) is a ligand specifically modifying the CCS of ions. Indeed specific non-covalent complexes can be form with a suitable SSR to reach the required selectivity and the CCS induced shift. A CID dissociation of the complex may be used after IMS separation to produce specific MS/MS spectra of the targeted analyte. This concept paves the way for new analytical strategies by ion mobility based on non-covalent complex formation. [less ▲]

Detailed reference viewed: 63 (17 ULg)
Full Text
Peer Reviewed
See detailLes univers vidéoludiques : des fictions mobiles et jouables
Barnabé, Fanny ULg

Poster (2014, June 18)

La question de la fiction constitue, depuis le début des années 2000, une clef d’entrée privilégiée pour étudier le médium vidéoludique. La capacité du jeu vidéo à prendre en charge la représentation ... [more ▼]

La question de la fiction constitue, depuis le début des années 2000, une clef d’entrée privilégiée pour étudier le médium vidéoludique. La capacité du jeu vidéo à prendre en charge la représentation d’une histoire par ses propres moyens (et non en empruntant ceux de la littérature ou du cinéma) a été tantôt affirmée (Ryan, 2003 ; Murray, 1998), tantôt contestée (Frasca, 1999 ; Juul, 2001 ; Eskelinen, 2001). Dès lors – même si les oppositions à son sujet sont aujourd’hui plus nuancées – elle demeure un objet problématique dont le traitement entraîne souvent d’importants détours théoriques. Les concepts de la narratologie « traditionnelle » (tels que celui d’un récit clos et prédéfini ou d’une narration « unidirectionnelle ») semblent a priori peu compatibles avec les impératifs d’interaction et de jouabilité qui sont au cœur de l’expérience vidéoludique. Quels outils adopter, en conséquence, pour décrire ce qui advient de la fiction lorsqu’elle est prise en charge par le jeu ? C’est à cette question que nous tâcherons de répondre en définissant les contours d’une notion souvent évoquée par la recherche, mais peu théorisée : celle d’« univers fictionnel ». Pour ce faire, nous nous nourrirons tant des avancées des games studies et des « play studies » (Triclot, 2011) que des théories de la fiction (Schaeffer, 1999) et de ses modes actuels de consommation par les amateurs (Jenkins, 2006). La distinction opérée par Amato (2005) entre les notions de cosmos, de diégèse et de ludiégèse permettra également de préciser la définition de ce qu’est un univers lorsqu’il est régi par le jeu. En effet, la narrativité propre au jeu vidéo ne semble pas répondre à la logique linéaire du récit : une grande part de l’histoire n’est généralement présente que de manière « latente » (Letourneux, 2005) dans une série d’éléments hétérogènes (le texte, l’interface, les décors, les sons, les objets…), situés à différents niveaux de l’œuvre et dont le sens narratif peut ou non être activé par le joueur (Guardiola, 2005 parle, à ce titre, de la dimension « permissive » du jeu vidéo). Pour décrire cette pluri-dimensionnalité et cette dispersion de l’histoire au sein d’« éléments de narrativisation » (Genvo, 2002), la notion de récit apparaît comme réductrice. À l’inverse, celle d’univers (définie dès lors comme un agencement d’éléments non hiérarchisés et éventuellement porteurs d’une narrativité latente) présente une forte opérationnalité, due principalement à deux de ses caractéristiques : son ouverture et sa nature modulable. Son ouverture, tout d’abord, car elle permet non seulement de prendre en compte l’ensemble des composantes de la fiction qui sont internes à l’œuvre vidéoludique, mais aussi celles qui lui sont externes (qu’il s’agisse du paratexte, des livrets des jeux, des bandes annonces,… ou encore de véritables développements narratifs autonomes, réalisés sur différents médias). Sa malléabilité, ensuite, car le concept d’univers, contrairement à celui de narration, admet l’interactivité : c’est le joueur qui actualise le récit (il participe à son énonciation) et qui, par la continuité de sa présence, organise les « éléments de narrativisation » en une configuration cohérente. En outre, concevoir la fiction comme un agencement de diverses composantes permet d’envisager les constantes évolutions que lui font subir les communautés d’amateurs : ceux-ci, en confrontant leurs représentations, développent par exemple des modèles collectifs « non officiels » (les « fanons » ; voir Hellekson et Busse, 2006) qui ont un impact certain sur la vie des fictions. L’univers fictionnel constitue, en somme, un outil théorique porteur qui rend possible la description des points de passage entre jeu et fiction et l’évaluation des contraintes que l’un exerce sur l’autre. Toutefois, bien qu’il ait initialement été élaboré pour correspondre au domaine spécifique du jeu vidéo, le concept semble déborder de ces premiers questionnements et s’adapter, plus généralement, à l’étude des modes actuels de production et de consommation de la fiction. En effet, son ouverture invite, d’une part, à élargir la conception traditionnelle de la narration et à l’envisager comme un ensemble transmédiatique. D’autre part, sa nature d’agencement n’est pas sans rappeler les théories d’Azuma (2008) selon lesquelles les fictions postmodernes ne sont plus considérées comme des unités finies et fermées, mais comme des agencements qui puisent dans un fonds commun, une « base de données » perpétuellement renouvelée. Chaque élément investi par la fiction intègre ce fonds commun et devient alors susceptible de connaître des continuations, des réappropriations, des réagencements. Les histoires conçues sur ce mode ne sont pas lues, mais vécues et explorées : la lecture devient une expérience et une expérimentation. [less ▲]

Detailed reference viewed: 22 (3 ULg)
Full Text
Peer Reviewed
See detailPolyester-based microcarriers with enhanced surface properties for tissue engineering
Markvicheva, Elena; Privalova, Anna; Sevrin, Chantal ULg et al

Poster (2014, June 17)

Detailed reference viewed: 6 (0 ULg)
Full Text
Peer Reviewed
See detailIN VITRO STUDY OF A FIBER NETWORK TAILORED AS 3D-CELL MODEL
Sevrin, Chantal ULg; Lombart, François ULg; Godino, Miguel et al

Poster (2014, June 17)

Detailed reference viewed: 6 (1 ULg)
Full Text
Peer Reviewed
See detailA forward genetic screen to identify hydrogenase-deficient mutants in the unicellular green alga Chlamydomonas reinhardtii
Emonds-Alt, Barbara ULg; Godaux, Damien ULg; Cardol, Pierre ULg et al

Poster (2014, June 15)

The ability of the unicellular green alga Chlamydomonas reinhardtii to evolve molecular hydrogen (H2) is due to the presence of oxygen-sensitive Fe-hydrogenases (HydA1/2), expressed in anoxic conditions ... [more ▼]

The ability of the unicellular green alga Chlamydomonas reinhardtii to evolve molecular hydrogen (H2) is due to the presence of oxygen-sensitive Fe-hydrogenases (HydA1/2), expressed in anoxic conditions that drive the photosynthetic electron flow to reduce protons into H2. In order to identify new players involved in H2 photoproduction in Chlamydomonas, an insertion mutant library was generated using cassettes conferring resistance to hygromycin or paromomycin. Hydrogenase activity is physiologically relevant during a transition from dark anoxia to light. In dark anoxic conditions, the cellular redox poise is high and the photosynthetic electron transport chain is fully reduced. Upon illumination, hydrogenase activity allows the reoxidation of photosynthetic intersystem electron carriers until oxic conditions and carbon fixation ability are restored. We thus designed an in vivo fluorescence imaging screen based on the different kinetics of photosynthesis induction between wild type and hydrogenase-deficient mutants [1]. At this stage, three putative hydrogenase mutants have been identified on 10,000 transformants. Molecular characterization of the insertion site of the resistance cassette by TAIL-PCR and genetic analyses of the linkage between the antibiotic resistance and the fluorescence phenotype showed that one mutant was untagged with the resistance while two tagged mutants were deficient for the HydG assembly factor. [less ▲]

Detailed reference viewed: 16 (7 ULg)
Full Text
See detailDétermination de la teneur en équol dans les laits commercialisés en Wallonie (Belgique)
Daems, Frédéric ULg; Jasselette, Christophe; Franckson, Delphine et al

Poster (2014, June 13)

Detailed reference viewed: 11 (0 ULg)
Full Text
Peer Reviewed
See detailTrouble de la reconnaissance de soi chez des personnes atteintes de la maladie d'Alzheimer
Moyse, Evelyne ULg; Bastin, Christine ULg; Salmon, Eric ULg et al

Poster (2014, June 12)

Introduction : Outre des difficultés de mémoire épisodique, la maladie d’Alzheimer est associée à une altération progressive du fonctionnement de la mémoire sémantique où les connaissances du passé ... [more ▼]

Introduction : Outre des difficultés de mémoire épisodique, la maladie d’Alzheimer est associée à une altération progressive du fonctionnement de la mémoire sémantique où les connaissances du passé lointain sont mieux préservées que les connaissances acquises récemment. De plus, il a été rapporté que ce type de perte peut aussi se produire pour la reconnaissance de son propre visage. Une étude décrivait le cas d’une femme atteinte de la maladie d’Alzheimer à un stade avancé qui était incapable de se reconnaître sur des photographies prises dans un passé récent mais qui avait peu voire pas de difficultés à se reconnaître sur des photographies prises pendant les deux premières décennies de sa vie adulte. Cependant, la description d’une seule étude de cas pourrait être vue comme anecdotique. Objectifs : L’objectif de cette étude est d’évaluer si ce type de difficultés peut s’observer dans un plus large échantillon de patients. Pour ce faire, des patients à des stades légers à modérés de la maladie sont comparés à des sujets âgés sains sur une tâche de reconnaissance de visages (soi, familier, inconnu) appartenant à différentes périodes de vie (20 ans jusqu’à récemment). Résultats : Au stade léger, les patients présentaient des difficultés uniquement pour reconnaître le visage d’une personne familière alors qu’au stade modéré de la maladie, ces difficultés s’observaient à la fois pour le visage familier et le propre visage. De plus, comparés aux sujets âgés sains, les patients modérés avaient des difficultés pour se reconnaître sur des photos récentes, alors qu’aucune différence n’était observée pour les autres périodes de vie. Par contre, aucune différence entre les patients légers et leurs sujets contrôles n’était observée selon l’âge des visages. Par ailleurs, l’analyse des temps de réaction montraient que ces deux groupes de participants étaient plus lents pour reconnaître les photos anciennes par rapport aux photos récentes. Conclusion : La présente étude révèle que les difficultés de reconnaissance des visages évoluent avec l’avancement de la maladie, avec des difficultés qui touchent uniquement la reconnaissance de visages familiers au stade léger de la maladie mais qui s’étendent au propre visage au stade modéré. De plus, une perte graduée dans le temps de la reconnaissance de soi est observée chez les patients modérés (moindre reconnaissance de son visage récent) mais pas chez les patients légers. Au contraire, un ralentissement de la reconnaissance des photos anciennes par rapport aux photos récentes était constaté chez les patients légers ainsi que chez leurs sujets contrôles. Deux hypothèses sont avancées pour expliquer ce phénomène. Premièrement, les photos anciennes provoqueraient une réaction de surprise et par là, augmenteraient le temps de réponse. La seconde hypothèse postule plutôt une difficulté d’accès aux représentations antérieures de soi et de son proche. [less ▲]

Detailed reference viewed: 62 (5 ULg)
See detailGround-based transmission spectrum of WASP-80 b, a gas giant transiting an M-dwarf
Delrez, Laetitia ULg; Gillon, Michaël ULg; Lendl, Monika ULg et al

Poster (2014, June 09)

We present here some results from our ground-­based multi-­object spectroscopy program aiming to measure the transmission spectrum of the transiting hot Jupiter WASP-80b using the VLT/FORS2 instrument ... [more ▼]

We present here some results from our ground-­based multi-­object spectroscopy program aiming to measure the transmission spectrum of the transiting hot Jupiter WASP-80b using the VLT/FORS2 instrument. WASP-­80b is a unique object as it is the only known specimen of gas giant orbiting an M-dwarf that is bright enough for high SNR follow-­up measurements. Due to the nature of its host star, this hot Jupiter is actually more `warm' than `hot', with an estimated equilibrium temperature of only 800K. It is thus a prime target to improve our understanding of giant exoplanet atmospheres in this temperature range. [less ▲]

Detailed reference viewed: 4 (0 ULg)
Full Text
Peer Reviewed
See detailEffects of tillage practices and crop residue exportation on earthworm communities and soil physico-­chemical properties in silt loam arable soil (Belgium)
Lemtiri, Aboulkacem ULg; Colinet, Gilles ULg; Alabi, Taofic ULg et al

Poster (2014, June 08)

Earthworms are known to play integral roles in soils, and are often referred to as vital soil and ecosystem engineers due to their capacity to influence a wide range of chemical, physical, and biological ... [more ▼]

Earthworms are known to play integral roles in soils, and are often referred to as vital soil and ecosystem engineers due to their capacity to influence a wide range of chemical, physical, and biological properties of soil environments. Therefore, it is important to understand how earthworm communities are impacted by tillage systems and crop management practices. In the present study, earthworm and soil samples were collected from wheat cultivated fields in Gembloux, Belgium under the following four experimental treatments: (1) conventional tillage with crop residues left in the soil (CT/IN); (2) conventional tillage with crop residues removed from the field (CT/OUT); (3) reduced tillage with crop residues left in the soil (RT/IN); and (4) reduced tillage with crop residues removed from the field (RT/OUT). The different tillage systems were applied for four consecutive years prior to the initiation of the current study. Results indicated soil compaction was significantly higher in RT compared with CT up to a depth of 6–49 cm. Significant differences were not detected between residue incorporation depth systems, where results showed mean earthworm abundance was respectively 182.25 and 180 individuals.m-2 in CT and RT. Mean earthworm biomass was similarly not significantly different between CT and RT, where results were respectively 48.52 and 57.27 g.m-2. However, a significant difference was observed between IN and OUT treatments, suggesting the exportation of wheat residues will limit earthworm abundance and biomass in CT and RT plots. Data showed high representation of the endogeic earthworm ecological category, notably N. c. caliginosus regardless of treatment. Despite tillage system and exportation of crop residues, N. c. caliginosus, L. terrestris, and A. r. rosea exhibited high abundance, indicating tolerance to soil environmental conditions. For each depth, measures of soil physico-chemical properties showed significant differences among treatments. Furthermore, soil chemical property attributes were significantly higher in the first soil centimetres compared to lower soil layers. These results were attributable to earthworm activity and wheat residues, suggesting earthworms contributed to nutrient dynamics, particularly at increased soil depths. Overall, the results emphasise the influence of exportation of crop residues on earthworm community and also, the important influence of earthworm activity on soil physico-chemical properties change, processes which are closely linked. [less ▲]

Detailed reference viewed: 47 (12 ULg)
Full Text
Peer Reviewed
See detail[18F]UCB-H AS A NEW PET RADIOTRACER FOR SYNAPTIC VESICLE PROTEIN 2A
Bahri, Mohamed Ali ULg; Bastin, Christine ULg; Aerts, Joël ULg et al

Poster (2014, June 06)

Synaptic vesicle protein 2A (SV2A) is widely distributed in the brain and has been demonstrated to be involved in vesicle trafficking. The critical role of SV2A in proper nervous system function is shown ... [more ▼]

Synaptic vesicle protein 2A (SV2A) is widely distributed in the brain and has been demonstrated to be involved in vesicle trafficking. The critical role of SV2A in proper nervous system function is shown, for example, by the fact that it is a binding site and the primary mechanism of levetiracetam. Levetiracetam is an antiepileptic drug which has recently been suggested to reduce synaptic deficits in a mouse model for Alzheimer’s disease and to improve cognition in patients with amnestic mild cognitive impairment. We here aimed to investigate the cerebral distribution of [18F]UCB-H, a fluorine-18 radiolabelled PET imaging tracer, which has a high affinity with the SV2A. [18F]UCB-H was radiosynthesized under GMP conditions. Dynamic PET data of the head of four healthy volunteers were acquired over 100 minutes after injection of 170.4 ± 24.9 MBq of [18F]UCB-H. The arterial input function was obtained by blood sampling during the dynamic PET acquisition. The analysis of the blood data reveled a consistent amount of [18F]UCB-H in whole blood and plasma which indicates a very low degree of binding of the tracer to the red blood cells. The unchanged fraction of [18F]UCB-H in plasma showed a bi-exponential behavioral decrease with a starting fraction of 92% of the injected amount of the tracer, measured at 3 min post injection. This fraction decreased to about 50% at 10 min post injection. The [18F]UCB-H PET data showed a high and rapid uptake in the grey matter structures, matching the known ubiquitous distribution of the SV2A in the brain. The kinetics of the tracer in the brain was characterized by an initial high uptake phase followed by rapid washout allowing the standard compartmental modeling (1-tissue compartment, 2-tissue compartment, and Logan graphical analysis). The three models gave consistent results. The two-tissue compartment model fitted the experimental data best and provided a total distribution volume of the [18F]UCB-H in the brain greater than 7 mL/cm3 and a specific distribution volume around 3 mL/cm3. Our results suggest that [18F]UCB-H is a good candidate as radiotracer for brain SV2A proteins and could be used for human studies. In the future, SV2A modifications might be assessed in neurological pathologies such as Alzheimer’s disease. [less ▲]

Detailed reference viewed: 30 (7 ULg)
Full Text
Peer Reviewed
See detailComparison between wind speed observed at 100m height and wind speeds simulated by the WRF and MAR models
Doutreloup, Sébastien ULg; Fettweis, Xavier ULg; Erpicum, Michel ULg et al

Poster (2014, June 06)

In the context of FLEXIPAC project funded by "RELIABLE" program of Walloon Region (Belgium), the Laboratory of Climatology and Topoclimatology (LCT) of the University of Liège (Belgium) aims to adjust the ... [more ▼]

In the context of FLEXIPAC project funded by "RELIABLE" program of Walloon Region (Belgium), the Laboratory of Climatology and Topoclimatology (LCT) of the University of Liège (Belgium) aims to adjust the WRF regional model (v.3.4.) forced by ERA-Interim model. Our analysis shows that wind speeds at 100m height simulated by WRF are systematically overestimated compared to wind speeds extracted from wind productions of two wind farms. In order to identify this problem, four comparisons were performed in this contribution. Firstly, we compare WRF model with reanalysis based forcing model. Secondly, we compare two WRF simulations, where one of them has a more precise spatial resolution. Thirdly, we smooth WRF outputs in time (6-hr running mean) in order to study the accuracy of the 30-min variability generated by WRF model. Finally, we comp compare the WRF model with the MAR (v3.3.) regional model using the same forcing at its lateral boundaries. This last one seems to suggest that the MAR model better simulates wind speeds at 10m and at 100m than WRF model and then that wind speed underestimation by WRF is well linked to the WRF physics itself. [less ▲]

Detailed reference viewed: 55 (6 ULg)
Full Text
Peer Reviewed
See detailFunctional study of the Ser/Arg-rich splicing factor SRSF5a during zebrafish embryonic development
Joris, Marine ULg; Muller, Marc ULg; Motte, Patrick ULg

Poster (2014, June 05)

Nuclear pre-mRNA splicing is a key process regulating gene expression in eukaryotes. Splicing consists in the removal of introns and the joining of exons within a dynamic macromolecular complex called the ... [more ▼]

Nuclear pre-mRNA splicing is a key process regulating gene expression in eukaryotes. Splicing consists in the removal of introns and the joining of exons within a dynamic macromolecular complex called the spliceosome, which consist of five small nuclear ribonucleoproteins (snRNPs) and numerous non snRNPs proteins (1). Amongst these non snRNPs proteins, the SR proteins family constituted an important group of splicing factors that are involved in constitutive and alternative splicing (2,3). SR proteins are structurally related as they are characterized by one or two RNA-recognition motifs (RRMs) in N-ter and a C-terminal domain enriched in dipeptide Ser/Arg. Phylogenetic inference using the RRM domain allowed us to identify 13 encoding genes for SR proteins in the vertebrate model organism, Danio rerio. The Zebrafish is increasingly recognized as a powerful model for the study of vertebrate embryonic development in a physiological context. The roles of SR splicing factors during animal cell differentiation and development are largely unknown. The aim of the present research is to investigate SR proteins functions during zebrafish development by using molecular and genetic approaches. In this study, we investigated the role of the SR splicing factor SRSF5a. The expression profile was determined by in situ hybridization at 24, 48 and 72 hours post-fertilization and showed SRSF5a expression mainly in brain, retina and pharyngeal arches at these stages. Furthermore, SRSF5a knock-down by morpholinos microinjection strongly suggests an important role of this specific splicing factor during eyes and brain development. In order to gain insight into the molecular function of SRSF5a, we analysed control and morphant transcriptomes using high throughput RNA sequencing. Finally, we use a complementary approach to morpholinos and generate SRSF5a mutant fishes using TALENs (Tal effector nucleases)(4,5). 1. Wahl MC, Will CL, & Luhrmann R (2009) The spliceosome: design principles of a dynamic RNP machine. Cell 136(4):701-718. 2. Long JC & Caceres JF (2009) The SR protein family of splicing factors: master regulators of gene expression. Biochem J 417(1):15-27. 3. Graveley BR (2000) Sorting out the complexity of SR protein functions. RNA 6(9):1197-1211. 4. Moore et al. (2012) Improved Somatic Mutagenesis in Zebrafish Using Transcription Activator-Like Effector Nucleases (TALENs). Plos One 120(1):1-12. 5. Cade et al (2012) Highly efficient generation of heritable zebrafish gene mutations using homo- and heterodimeric TALENs. Nucleic acid research Vol 40, No 16:8001-8010. [less ▲]

Detailed reference viewed: 22 (5 ULg)
Peer Reviewed
See detailApproche lexicométrique des controverses climatiques
Scotto d'Apollonia, Lionel; Luxardo, Giancarlo; Piet, Grégory ULg

Poster (2014, June 05)

D’un point de vue historique, les controverses climatiques prennent racine à la fin du XIXe siècle et se sont déployées tout au long du XXe siècle. Elles prennent toutefois une tournure plus politique, en ... [more ▼]

D’un point de vue historique, les controverses climatiques prennent racine à la fin du XIXe siècle et se sont déployées tout au long du XXe siècle. Elles prennent toutefois une tournure plus politique, en ce début de XXIe siècle, en ce sens que le débat climatique « se priorise » dans les agendas politiques des Etats européens, de manière générale. Si les études sur les controverses climatiques tendent, certes, à se développer de plus en plus actuellement, l’approche linguistique demeure peu investie par rapport au potentiel analytique qu’elle pourrait apporter à la recherche sur le sujet. L’une des rares études lexicométriques concernant le climat est celle réalisée par Lamria Chetouani dont le corpus de textes s’étend de 1989 à 1990. Il faut aussi prendre en compte les travaux de Francis Chateauraynaud, qui a entrepris une démarche destinée au traitement des controverses s'appuyant sur un ensemble de techniques : la socio-informatique. Inscrit dans un cadre d’analyse socioépistémique des controverses socioscientifiques et en se basant sur un corpus de textes choisis autour de la période 2009 - 2010, notre article propose donc d'associer une analyse socio-informatique des controverses climatiques avec une utilisation d'outils lexicométriques. En nous concentrant sur le traitement discursif de quelques notions-clés, notamment l'incertitude et le risque, nous cherchons à croiser les résultats fournis par la lexicométrie (logiciel Lexico) avec ceux fournis par la socio-informatique (logiciel Prospero). En conclusion, nous ouvrons un espace de discussion sur les modes opératoires permettant d'articuler les deux approches. [less ▲]

Detailed reference viewed: 43 (0 ULg)
Full Text
See detailDesign and synthesis of high-affinity ligands of AMPA receptors and study of their Fluorine-18 radiolabeling
Deverdenne, François ULg; Goffin, Eric ULg; Plenevaux, Alain ULg et al

Poster (2014, June 05)

The AMPA subtype of glutamatergic receptors is the main actor in the excitatory neurotransmission in the mammalian central nervous system. These receptors are involved in the expression and the ... [more ▼]

The AMPA subtype of glutamatergic receptors is the main actor in the excitatory neurotransmission in the mammalian central nervous system. These receptors are involved in the expression and the maintenance of the long-term potentiation, a phenomenon closely linked to cognitive and memorization processes. Based on experimental data collected in recent years, the use of AMPA potentiators seems to be an interesting approach in the treatment of cognitive deficits (e.g. Alzheimer disease), schizophrenia or depression. Such AMPA signal potentiation could be mediated by positive allosteric modulators (PAMs) of the AMPA receptors, a class of compounds able to produce a fine signal tuning in the presence of the endogenous ligand in the synapse, providing less toxicity than direct agonists. With this approach, the laboratory of Medicinal Chemistry of Liège university developed many series of AMPA potentiators , among which 1,2,4-benzothiadiazine 1,1-dioxides (BTDs). In order to better understand the in vivo mapping of AMPA receptors and its evolution in neurological diseases, the present work aims at developing the design and the synthesis of BTDs positive allosteric modulators radiolabeled with a fluorine-18 atom. Based on previously synthesized series in this field, we investigate the synthesis of a new class of high-affinity AMPA potentiators characterized by the presence of a fluorine atom at selected positions on the structure of the AMPA potentiators. Thanks to in vitro pharmacological evaluations, we will further determine the best candidates for their fluorine-18 radiolabeling. [less ▲]

Detailed reference viewed: 30 (1 ULg)
Full Text
Peer Reviewed
See detailA PREFERENTIAL FOLDED CONFORMATION OF SOME BIS-(8-ISOPROPYL-ISOQUINOLINIUM) DERIVATIVES EXPLAINS STEREOSELECTIVE REDUCTION BY SODIUM BOROHYDRIDE
Dilly, Sébastien ULg; Badarau, Eduard; Dufour, Fabien et al

Poster (2014, June 05)

Small conductance Ca2+-activated K+ (SK) channels play a role in modulating the firing rate and the firing pattern of neurons [Waroux, Eur J Neurosci, 2005, 22, 3111]. A blockade of these targets could be ... [more ▼]

Small conductance Ca2+-activated K+ (SK) channels play a role in modulating the firing rate and the firing pattern of neurons [Waroux, Eur J Neurosci, 2005, 22, 3111]. A blockade of these targets could be useful for the treatment of cognitive dysfunction, neuronal hyperexcitability or dopamine related disorders [Liégeois, Curr Med Chem, 2003, 10, 625]. At the peripheral level, the inhibition of these channels was demonstrated to prevent and terminate atrial fibrillation [Diness, Circ Arrhythm Electrophysiol, 2010, 3, 380]. Moreover, SK channels might represent potential targets for a new class of anticancer agents due to their involvement in breast cancer cell migration [Potier, Mol Cancer Ther, 2006, 5, 2946]. So far, available blockers are not suitable CNS pharmacological tools being either peptides or small molecules with permanent positive charges [Liégeois, Curr Med Chem, 2003, 10, 625; Graulich, J Med Chem, 2007, 50, 5070; Badarau, Bioorg Med Chem Lett, 2011, 21, 6756]. Therefore, symmetrical bis-isoquinolinium compounds have subsequently been transformed to 1,2,3,4-tetrahydroisoquinoline analogues by using sodium borohydride leading to a diastereoisomeric mixture (figure 1) in order to obtain potential CNS-penetrating agents [Graulich, Bioorg Med Chem Lett, 2008, 18, 3440; Neny, Proceedings of the 12th International Conference on In Vivo Methods, Vancouver, Canada, 2008, 267; Koulchitsky, Acta Physiologica, 2009, 195, 670]. Resolution of these mixtures and characterization of the corresponding stereoisomers [Wouters, Eur J Med Chem, 2010, 45, 3240] are necessary before further biological evaluation. In a series of 8- isopropyl analogues, chiral resolution failed for the analogues with propyl and m-xylyl linkers since two and one peaks, respectively, were detected [Nistor, J Pharm Biomed Anal, 2013, 74, 273]. Could these results be explained by an ineffective resolution or would another phenomenon be involved? Further analysis using chiral chromatography, mass spectroscopy and circular dichroism of a sample of the propyl analogue revealed that it is a racemic mixture. X-ray cristallography and conformational analysis indicated a folded conformation of the propyl and m-xylyl analogues (figure 2) responsible for a stereoselective attack of the borohydride reagent during the reduction step. Additional 1H-NMR investigations support structural features detected by theoretical analysis. [less ▲]

Detailed reference viewed: 33 (5 ULg)
See detailLIGAND-INDEPENDENT IDENTIFICATION OF ORPHAN GPCR ARRESTIN BINDING
Dupuis, Nadine ULg; Gilissen, Julie ULg; Derj, Anouar ULg et al

Poster (2014, June 05)

Detailed reference viewed: 23 (9 ULg)
Peer Reviewed
See detailRelations between negative symptomatology and executive measures in schizophrenia.
Laloyaux, Julien ULg; Guettafi, Yassine; Dessart, Gregory et al

Poster (2014, June 03)

Introduction: Negative symptomatology and cognitive impairments are core features of persons diagnosed with schizophrenia that have a major negative impact on everyday life functioning. Further, some ... [more ▼]

Introduction: Negative symptomatology and cognitive impairments are core features of persons diagnosed with schizophrenia that have a major negative impact on everyday life functioning. Further, some authors (Konstantakopoulos et al., 2011) have suggested that negative symptoms and executive functions might represent different manifestations of the same syndrome, but this relation remains poorly understood. Objective: The objective was to explore relations between negative symptomatology (and in particular apathy) and executive functions in persons diagnosed with schizophrenia. Method: Twenty-seven individuals diagnosed with schizophrenia were evaluated with an extensive executive battery in addition to several measures of negative symptomatology (including specific measures of apathy) and real world functioning. Results: Results revealed that apathy was significantly related to measures of initiation (i.e. verbal fluency) and everyday life functioning. Moreover, more general measures of negative symptomatology were significantly related to multitasking abilities and cognitive flexibility. Discussion: In this study, we assessed the relations between negative symptomatology and executive measures. The results confirmed the links between these constructs, thus suggesting a common neural substrate. Conclusion: Based on results from the present study, executive dysfunctions and negative symptomatology may be seen as representing different manifestations of the same syndrome. [less ▲]

Detailed reference viewed: 55 (10 ULg)
See detailComparison of Indicators to Evaluate the Resilience of Lab Scale Continuously Stirred Anaerobic Reactors Submitted to Biological Dysfunctions
Lemaigre, Sébastien; Adam, Gilles ULg; Goux, Xavier et al

Poster (2014, June 02)

Detailed reference viewed: 14 (0 ULg)
Full Text
Peer Reviewed
See detailApplication of hyperspectral Raman imaging to the analysis of a self-emulsifying drug delivery system (SEDDS).
Sacre, Pierre-Yves ULg; De Bleye, Charlotte ULg; Netchacovitch, Lauranne ULg et al

Poster (2014, June)

Self-emulsifying drug delivery systems (SEDDS) are mixtures of drug and excipients that undergo emulsification when exposed to water. This pharmaceutical form is used to enhance the oral absorption of ... [more ▼]

Self-emulsifying drug delivery systems (SEDDS) are mixtures of drug and excipients that undergo emulsification when exposed to water. This pharmaceutical form is used to enhance the oral absorption of poorly water-soluble drugs. The API is finely dispersed in the excipients and forms a solid solution increasing its dissolution rate. Hyperspectral Raman imaging is a powerful tool that combines both spectral and spatial information. It returns qualitative and quantitative information useful during the development or the characterization of pharmaceutical preparations. The studied formulation consisted of a BCS 2 API (high permeability, low solubility) dispersed in excipients mainly composed of Lauroyl macrogol-32 glycerides (>50%). Two different preparations were analyzed: 100% of API dissolved and 70% of API dissolved with 30% of API powder added to the formulation. The two formulations have therefore exactly the same qualitative and quantitative composition but different spatial distribution and dispersion of the API mimicking a problem during the process. First a confocal Raman microscopic analysis was performed to evaluate the solid state of the API in the formulations. Then, an evaluation of the particle size was performed. These results are important since they can affect the bioavailability of the API and therefore its activity. Beside the microscopic scale analysis, a macroscopic imaging quantitative PLS model has been developed. The method has been validated within +/- 10% acceptance limits following the total error approach. This validated quantitative model enables reliable quantitative analysis at the pixel level of Raman images providing meaningful chemical images. [less ▲]

Detailed reference viewed: 25 (6 ULg)
Full Text
Peer Reviewed
See detailInvestigation of differential virus transmission efficiency in aphid strains: from biological to proteomic assays
Bosquée, Emilie ULg; Francis, Frédéric ULg

Poster (2014, June)

Aphids are well known for their variable efficiency in virus transmission to host plant. Not only aphid species but also aphid strain is an important factor to consider in the plant-aphid-virus ... [more ▼]

Aphids are well known for their variable efficiency in virus transmission to host plant. Not only aphid species but also aphid strain is an important factor to consider in the plant-aphid-virus interactions. In order to investigate these relations, different approaches should be developped from biological observations assessing the virus transmission efficiency to molecular tasks to better know the involved mechanisms in the aphid vector. After a period of virus acquisition on an artificial diet (depending on the kind of transmission, permanent or non permanent ways), the virus transmission rate were assayed and followed by the determination of the presence of virus in the aphid by PCR or immudetection. The aphids were then collected to investigate the variation of aphid proteome and potential involvement in virus interactions. Changes in protein expressions were investigated using a 2D-DIGE approach comparing most and least efficient aphid strains selecting different aphid – virus models (PVY and PLRV in potato, BYDV in wheat, CMV on tobacco) . The proteome changes were analysed using the samespot software. Protein spots with significant up- and down expressions were then mechanically picked, trypsin digested and analysed by Maldi-Tof-Tof. Significantly changed proteins were classify according to metablic pathways and biological functions. Interesting proteins found to probably interact with virus were not only detected from aphid but also from related bacterial symbionts. Theses results were discussed in order to better understand virus – vector relations and potentially promote new ways to control virus transmitted by hemipteran pest. [less ▲]

Detailed reference viewed: 27 (15 ULg)
Peer Reviewed
See detailETEROGENEITÀ GENETICA DI NOROVIRUS BOVINI IDENTIFICATI IN ITALIA
Di Felice, Eliabetta; Di Profio, Federica; Melegari, Irene et al

Poster (2014, June)

I norovirus (NoV) sono piccoli virus a RNA monocatenario appartenenti alla famiglia Caliciviridae. Sulla base dell’analisi di sequenza del gene ORF2 codificante per la proteina capsidica VP1, i NoV sono ... [more ▼]

I norovirus (NoV) sono piccoli virus a RNA monocatenario appartenenti alla famiglia Caliciviridae. Sulla base dell’analisi di sequenza del gene ORF2 codificante per la proteina capsidica VP1, i NoV sono attualmente classificati in sei genogruppi (G), con GI, GII e GIV responsabili di gastroenterite nell’uomo. Calicivirus enterici morfologicamente simili a NoV umani sono stati identificati per la prima volta in vitelli diarroici nel Regno Unito nel 1978 e in Germania nel 1980. Il sequenziamento nucleotidico dell’intero genoma ha permesso di classificare i NoV bovini (BoNoV) all’interno del genogruppo III in due genotipi, GIII.1 (prototipo Bo/Jena/80/DE) e GIII.2 (prototipo Bo/Newbury/76/UK). I BoNoV hanno una diffusione mondiale con una maggiore prevalenza di virus GIII.2-like. Tuttavia, studi recenti basati sull’analisi nucleotidica a livello della giunzione fra la polimerasi (RdRp) ed il capside, hanno dimostrato la circolazione di ceppi ricombinanti. Nel presente lavoro vengono riportati i risultati di un’indagine per la ricerca e tipizzazione di BoNoV condotta su quattro allevamenti bovini ubicati nelle province di Teramo e Pescara. A tal fine, 104 tamponi rettali collezionati da vitelli asintomatici sono stati sottoposti a nested RT-PCR impiegando due set di primer specifici per BoNoV in grado di amplificare un frammento di 326 bp della RdRp. L’RNA di BoNoV è stato identificato nel 10,5% (11/104) degli animali testati. L'analisi di sequenza ha evidenziato per nove sequenze un’elevata identità nucleotidica (nt) (88-96%) con i ceppi GIII.2-like, mentre per due è stata rilevata la maggiore identità (87-90% nt) con i BoNoV GIII.1-like. Per sette ceppi è stata ottenuta anche una sequenza di circa 750 bp che includeva oltre che la regione parziale della RdRp, la regione 5’ capsidica. Sulla base dell’analisi molecolare, cinque ceppi sono risultati strettamente correlati con BoNoV GIII.2-like, mentre solo uno dei due ceppi con polimerasi GIII.1-like, ha mostrato la maggiore identità nucleotidica nei confronti di BoNoV appartenenti al genotipo 1. Il ceppo 80/TE/IT che possedeva una polimerasi GIII.1-like, a livello capsidico ha mostrato la più alta identità con ceppi GIII.2-like, suggerendo un fenomeno di ricombinazione a livello della giunzione ORF1/ORF2. [less ▲]

Detailed reference viewed: 13 (0 ULg)
Full Text
Peer Reviewed
See detailInhibition of PDH Kinase as a new therapeutic target for Age-related Macular Degeneration (AMD)
Arslan, Deniz ULg; Pirotte, Bernard ULg; De Tullio, Pascal ULg et al

Poster (2014, June)

Metabolomics is one of the most recent technologies in the world of Omics sciences. It aims at studying metabolome, which is composed of small molecular weight organic molecules (called metabolites) of a ... [more ▼]

Metabolomics is one of the most recent technologies in the world of Omics sciences. It aims at studying metabolome, which is composed of small molecular weight organic molecules (called metabolites) of a cell, an organism or a biological system. This approach gives rise to a growing number of applications in many areas, such as biomarkers discovery, clinical studies, drug efficacy and toxicity evaluation, diagnostic tools, quality control. One of the most interesting features of metabolomics is its capability to extract biochemical information reflecting biological events and then to be a powerful tool in the knowledge of the aetiology of some pathologies. Indeed, it is clear that every disease could alter more or less drastically the metabolic profile of the patients. Then a metabolomics approach could highlight the biochemical pathways affected and could allow the identification of new putative therapeutic strategies or targets that could be useful in a new drug discovery strategy. As proteomics, metabolomics approach represents a new and powerful tool for Medicinal Chemistry. Age-related Macular Degeneration (AMD) is a leading cause of vision loss in the western world among people aged 50 or older. 90% of all vision loss due to AMD results from the exudative form, which is characterized by choroidal neovascularization (CNV). Age-related changes that induce pathologic CNV are incompletely understood. A successful application of anti-VEGF approaches in the clinic is obviously a turning point in AMD treatment. Nevertheless, despite such important advances, critical issues remain to be addressed. To better understand the aetiology of this pathology, we used and improved a murine model of laser-induced choroidal neovascularization and applied a 1H NMR metabolomics study. This approach leads to the emergence of different putative biomarkers and to the validation of the CNV model for an experimental study of AMD. Among these “biomarkers”, lactate appears to be clearly involved in the development of AMD. The modulation of their plasma concentration by treatment of the animals with synthetic compounds and more specifically Pyruvate DesHydrogenase Kinase inhibitors (PDHK) significantly decrease the impact of laser induced CNV. Starting from these results, the development of new PDHK inhibitors could open the way to innovative treatment opportunities in AMD disease. [less ▲]

Detailed reference viewed: 29 (17 ULg)
Full Text
See detailTowards a real time release approach for manufacturing tablets using NIR spectroscopy
Pestieau, Aude ULg; Krier, Fabrice ULg; Thoorens, Grégory et al

Poster (2014, June)

Detailed reference viewed: 11 (1 ULg)
Peer Reviewed
See detailEffect of task demands on phonological acquisition : the acquisition of phonemes in French speaking children aged 30 to 53 months in four different contexts.
Maillart, Christelle ULg; Vaucel, Cécile; Macleod, Andrea

Poster (2014, June)

When children first begin to produce the phonemes of their language, their productions are characterized by a high degree of variability (e.g., Ferguson & Farwell, 1975) and are influenced by task demands ... [more ▼]

When children first begin to produce the phonemes of their language, their productions are characterized by a high degree of variability (e.g., Ferguson & Farwell, 1975) and are influenced by task demands (Khami, Catts, & Davis, 1984). As children’s phonological representations become more defined, their productions become more stable and less influenced by the task demands. Despite the clinical significance of phonological variability, there exists no normative data that can be used to objectively describe this variability in French. The goal of the present study was to describe variability and consistency among French-speaking children between the ages of 30 and 53 months, according to task demands. A total of 153 children participated in the present study and were equally distributed in four groups (aged 30-35, 36-41, 42-47, and 48-53 months). We created a picture identification task with 65 target words, which contained the consonants of French in word initial, medial and final position. The children were asked to produce these words in four different contexts : 1) picture naming ; 2) word repetition ; 3) sentence repetition ; 4) spontaneous language. Two measures of consistency were used. (1) A consonant level analysis that investigated the stability of phonological accuracy. (2) A word level analysis that investigated the consistency of productions across the four tasks. We predict that younger children will be more influenced by changes in task complexity than older children. [less ▲]

Detailed reference viewed: 20 (0 ULg)
Full Text
Peer Reviewed
See detailResearch of phosphate accumulating microorganisms from WWTPs for the recovery of phosphorus from organic wastes (3BV.3.47)
Tarayre, Cédric ULg; Michels, Evi; Buysse, Jeroen et al

Poster (2014, June)

Many wastes containing reusable components, such as nitrogen, phosphorus and potassium, are not exploited through ideal processes. As an example, in Wallonia (Belgium), the main treatment applied to ... [more ▼]

Many wastes containing reusable components, such as nitrogen, phosphorus and potassium, are not exploited through ideal processes. As an example, in Wallonia (Belgium), the main treatment applied to sewage sludge consists in incinerating the material. Such a process is chosen when the heavy metals are too concentrated in the sludge, preventing an agricultural use. However, sewage sludge, as well as manure, slurry and digestate, contain notable amounts of nutrients (nitrogen, phosphorus and potassium). Some Waste Water Treatment Plants (WWTPs) are actually designed in order to promote Phosphate Accumulating Organisms (PAOs), able to store or release phosphorus in accordance with the environmental conditions. The aim of this work is to isolate PAOs from WWTPs and evaluate their applicability to phosphorus recovery from organic wastes. Metagenomics and metabolic properties are also considered. This work is supported by the BioRefine Project, a European project in which various member states focus on recovery of inorganics from organic wastestreams. [less ▲]

Detailed reference viewed: 13 (2 ULg)
Peer Reviewed
See detailStereoselective synthesis of peptidoglycan fragments on solid support
Simon, Justine ULg; Lamborelle, Nicolas ULg; Joris, Bernard ULg et al

Poster (2014, June)

The mammalian proteins, Nod1 and Nod2, are able to recognize peptidoglycan motifs during bacterial infection. Interestingly, Nod1 is a detector of peptides and muropeptides containing the meso-2,6 ... [more ▼]

The mammalian proteins, Nod1 and Nod2, are able to recognize peptidoglycan motifs during bacterial infection. Interestingly, Nod1 is a detector of peptides and muropeptides containing the meso-2,6-diaminopimelic acid (m-A2pm), a non-proteinogenic amino acid found in Gram- bacteria. In this work, we describe a synthesis of peptidoglycan motifs entirely on solid support. Solid-Phase Peptide Synthesis (SPPS), Cross Metathesis (CM) and sugar chemistry are three methods to anchor respectively amino acids, m-A2pm and sugars derivatives on a resin as solid support. [less ▲]

Detailed reference viewed: 46 (6 ULg)
Full Text
See detailRole of estradiol in the feminization of lordosis behavior in female mice
Trouillet, Anne-Charlotte ULg

Poster (2014, June)

The classic theory of mammalian brain and behavioral sexual differentiation holds that an organizational action of testosterone, secreted perinatally by the male’s testes, controls male-typical aspects of ... [more ▼]

The classic theory of mammalian brain and behavioral sexual differentiation holds that an organizational action of testosterone, secreted perinatally by the male’s testes, controls male-typical aspects of brain and behavioral development, whereas no active perinatal sex hormone signaling is required for female-typical differentiation. However, it has recently been shown using aromatase knock out (ArKO) mice, which are deprived of estradiol due to a targeted mutation in the aromatase gene, that estradiol may also actively contribute to the differentiation of female-typical aspects of behavior over a specific pre-pubertal period. Female ArKO mice showed significantly lower levels of lordosis behavior than wild type controls following adult ovariectomy and treatment with ovarian hormones. This deficit was restored by treating female ArKO mice with estradiol benzoate between postnatal days 15 and 25. However, the mechanism by which estradiol acts prepubertally in female mice to feminize lordosis behavior remains to be elucidated. Therefore, in a first attempt, we are determining which neuropeptides are in particularly sensitive to estradiol action over the prepubertal period. We will focus on neuropeptides which have been shown to be implicated in lordosis behavior. Studies by the group of Micevych have proposed an important role for NPY and beta-endorphin (B-END) neurons in the arcuate nucleus (ARC) in the estradiol-mediated activation of lordosis behavior in female rats. An in vitro study recently showed that kisspeptin directly activates ARC B-END neurons. This is particularly interesting since unpublished results from our laboratory showed that Kp neurons are directly involved in the expression of lordosis behavior. We are thus currently determining the expression of NPY, B-END, and kisspeptin in the ARC as well as μ-opioid receptors MORs in the MPN over the prepubertal period and their possible modulation by prepubertal estradiol treatment. [less ▲]

Detailed reference viewed: 22 (4 ULg)