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See detailDevelopment of noninvasive genetic identification methods and polymorphic microsatellites for the Pyrenean desman (Galemys pyrenaicus)
Gillet, François ULg; Cabria Garrido, Maria Teresa; Némoz, Mélanie et al

Poster (2012, August)

The Pyrenean desman (Galemys pyrenaicus) is probably one of the most threatened European mammal species. This small insectivorous and semi-aquatic species is endemic to the Pyrenean Mountains and of the ... [more ▼]

The Pyrenean desman (Galemys pyrenaicus) is probably one of the most threatened European mammal species. This small insectivorous and semi-aquatic species is endemic to the Pyrenean Mountains and of the north of the Iberic Peninsula. Many biologic aspects of this species are currently suffering from a major lack of information, particularly those concerning its genetics. Therefore the implementation of conservative efforts for the Pyrenean Desman remains extremely difficult. In order to improve the knowledge of this vulnerable species and notably, to better understand its distribution area, the first aim of our research was to develop non invasive genetic identification methods based on faeces. The second aim was the development of several polymorphic microsatellites markers in order to have a first look at the genetic structure of the Pyrenean Desman in its French distribution area. The identification methods were developed on the basis of the sequencing of a small mitochondrial DNA (cyt b) fragment as well as a RFLP method. These approaches led to the identification of the Pyrenean desman and to the differentiation of the latter from two other species living in the same type of habitat, the white-throated dipper (Cinclus cinclus) and the water shrew (Neomys fodiens). More than fifteen polymorphic microsatellites markers could be found for the Pyrenean Desman and their genotyping revealed a low number of alleles per locus (two to five). The results of this preliminary work tend to show a low genetic diversity for the Pyrenean Desman but this result needs to be confirmed in the future with a more extended and complete study. [less ▲]

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See detailOzone tropospheric and stratospheric trends (1995-2011) at six ground-based FTIR stations (28°N to 79°N)
Vigouroux, Corinne; De Mazière, Martine; Demoulin, Philippe ULg et al

Poster (2012, August)

Five ground-based stations in Western Europe, from 79°N to 28°N, all part of the Network for the Detection of Atmospheric Composition Change (NDACC), have joined their efforts to homogenize and optimize ... [more ▼]

Five ground-based stations in Western Europe, from 79°N to 28°N, all part of the Network for the Detection of Atmospheric Composition Change (NDACC), have joined their efforts to homogenize and optimize the retrievals of ozone profiles from FTIR (Fourier transform infrared) solar absorption spectra. Using the optimal estimation method, distinct vertical information can be obtained in four layers: ground—10 km, 10—18 km, 18—27 km, and 27—42 km, in addition to total column amounts. Vigouroux et al. (2008) applied a bootstrap resampling method to the ozone data to determine the trends of the total columns and of the partial columns in the above four layers, over the period 1995-2004. The updated trends for the period 1995-2009 have been published in the WMO 2010 report. Here, we present the updated trends, obtained using the bootstrap resampling method, for the 1995-mid-2011 period, for the five European stations and also for the station Thule, Greenland (77°N), which has joined this effort. The trends have also been estimated using a multiple regression model including the Quasi Biennial Oscillation (QBO) and the solar flux as explanatory variables. The trends obtained by the two methods will be compared and discussed. One of the major results is the significant positive trend observed in the upper stratosphere at the station Jungfraujoch (47°N), which provides a sign of ozone recovery at mid-latitudes. Significant positive trends are also observed in the upper stratosphere at the high latitude stations. [less ▲]

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See detailAnimal circus: de dierenwereld in de poëzie van Hans Faverey
Dieu, Véronique ULg

Poster (2012, August)

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See detailDevelopment of original 2-aryloxy/arylamino-5-cyanobenzenesulfonylureas as thromboxane A2 receptor antagonists
Bambi Nyanguile, Sylvie-Mireille ULg; Hanson, Julien ULg; Dogné, Jean-Michel et al

Poster (2012, August)

A series of novel 2-aryloxy/arylamino-5-cyanobenzenesulfonylureas were synthesized. The newly synthesized compounds were tested in vitro and ex vivo as thromboxane A2 receptor antagonists. Some of the ... [more ▼]

A series of novel 2-aryloxy/arylamino-5-cyanobenzenesulfonylureas were synthesized. The newly synthesized compounds were tested in vitro and ex vivo as thromboxane A2 receptor antagonists. Some of the test compounds showed potent thromboxane A2 receptor antagonist activity. Three compounds (7h, 8h and 8e) were identified as leads for further pharmacological and toxicological studies. [less ▲]

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See detailCharacterization of Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) overwintering sites
Fassotte, Bérénice ULg; Durieux, Delphine ULg; Francis, Frédéric ULg et al

Poster (2012, August)

Originally introduced as a biological control agent, the multicoloured Asian ladybeetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), has become an invasive pest throughout Europe and North ... [more ▼]

Originally introduced as a biological control agent, the multicoloured Asian ladybeetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), has become an invasive pest throughout Europe and North America in the last few years. Although its effectiveness to control aphid and coccid populations was impressive, some negative impacts appeared rapidly, notably on human health. Indeed, to protect themselves from cold temperatures, H. axyridis individuals move inside dwellings and buildings and form large aggregations in concealed portions of structures to overwinter. The aggregating beetles are responsible for some annoyances due to, on one hand, the number of individuals inside homes and, on the other hand, the hemolymph secretions they release when they are disturbed, which can cause allergic reactions. In order to highlight the specific features of infested houses, we investigated a large number of overwintering sites in Wallonia between 2007 and 2011. These sites were characterized through a survey sent to homeowners confronted to invasion problems. This survey was mainly focused on a general description of the infested house (type, colour, infested floor(s), building material), the orientation of the colonized rooms and the position of the beetles’ cluster. The collected data indicate that H. axyridis preferentially selects isolated brick houses with red or white fronts to take shelter. Aggregations are mostly located at the first floor, essentially inside south, west or southwest oriented rooms. Furthermore, ladybeetles generally gathered into wooden windows frames facing south, west or southwest and to a lesser extent, in the upper corners of walls presenting the same orientation. All these results contribute to improve the knowledge on the aggregative behaviour of H. axyridis and could promote the development of more specific and efficient management methods to prevent massive infestations into dwellings, such as artificial shelters or trapping systems located at the outside of buildings. [less ▲]

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See detailRetrievals of ethane from ground-based high-resolution FTIR solar observations with updated line parameters: determination of the optimum strategy for the Jungfraujoch station.
Bader, Whitney ULg; Perrin, Agnès; Jacquemart, David et al

Poster (2012, August)

Ethane (C2H6) is the most abundant Non-Methane HydroCarbon (NMHC) in the Earth’s atmosphere, with a lifetime of approximately 2 months. C2H6 has both anthropogenic and natural emission sources such as ... [more ▼]

Ethane (C2H6) is the most abundant Non-Methane HydroCarbon (NMHC) in the Earth’s atmosphere, with a lifetime of approximately 2 months. C2H6 has both anthropogenic and natural emission sources such as biomass burning, natural gas loss and biofuel consumption. The retrieval of ethane from ground-based infrared spectra is challenging. Indeed, ethane has a complicated spectrum with many interacting vibrational modes and the current state of ethane parameters in HITRAN (see http://www.hitran.com) was rather unsatisfactory in the 3 μm region. In fact, PQ branches outside the 2973–3001 cm-1 range are not included in HITRAN, and most P and R structures are missing. New ethane absorption cross sections recorded at the Molecular Spectroscopy Facility of the Rutherford Appleton Laboratory (Harrison et al., 2010) are used in our retrievals. Pseudoline parameters fitted to these ethane spectra have been combined with HITRAN 2004 line parameters (including all the 2006 updates) for all other species encompassed in the selected microwindows. We evaluated the impact on spectral residuals induced by the update of two O3 lines (encompassed in the PQ3 µ-window) corrected by P. Chelin (LPMA, Paris, France). We also quantified the improvement brought by the update of the line positions and intensities of methyl chloride (CH3Cl) in the 3.4 µm region (Bray et al., 2011). The ethane a priori volume mixing ratio (VMR) profile and associated covariance are based on synthetic data from CHASER 3-D chemical transport model (CTM). In this contribution, we will present updated ethane (total) column retrievals, using the SFIT-2 algorithm (v3.91) and high-resolution Fourier Transform Infrared (FTIR) solar absorption observations recorded with a Bruker 120HR instrument, at the high altitude research station of the Jungfraujoch (46.5°N, 8°E, 3580 m asl), within the framework of the Network for the Detection of Atmospheric Composition Change (NDACC, visit http://www.ndacc.org). Comparisons with synthetic data produced by two chemical transport models (CHASER and the one of the University of Oslo) will also be presented and analyzed, aiming at the determination and interpretation of long-term trends and interannual variations of ethane at Northern mid-latitudes. [less ▲]

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See detailHepatitis E virus infection in domestic swine in Belgium
Thiry, Damien ULg; Mauroy, Axel ULg; Brochier, Bernard et al

Poster (2012, August)

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See detailFirst steps of a new methodology for integrating ground-based ozone profile data
Pastel, M.; Godin-Beekmann, S.; Mahieu, Emmanuel ULg et al

Poster (2012, August)

A new methodology is developed for integrating complementary ground-based data sources to provide consistent ozone vertical distribution time series as well as tropospheric and stratospheric ozone partial ... [more ▼]

A new methodology is developed for integrating complementary ground-based data sources to provide consistent ozone vertical distribution time series as well as tropospheric and stratospheric ozone partial columns. Primary results are presented for the Alpine station of the Network for the Detection of Atmospheric Composition Changes (NDACC). Ozone measurements from the lidar at Haute-Provence Observatory, the microwave spectrometer at Bern and the FTIR spectrometer at the Jungfrauch station are used for this purpose. First step is to evaluate the validity domain of ozone profile data considered here by assessing instrumental error and vertical resolution. Each instrument has its own vertical resolution; therefore adjustments need to be done for the creation of an homogeneous data set. Indeed, because of the higher resolution of lidar measurements, smoothing of the data is necessary for the comparison with FTIR and microwave measurements. However, smoothing the data induces a loss of scientific information. Therefore a compromise has to be established and discussed. The various intercomparisons provide an evaluation of the differences due to instrumental error and atmospheric variability. The statistical method used for combining the different measurements in order to obtain ozone vertical profile time series consistent with total ozone measurements is then discussed. [less ▲]

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See detailBreeding sites of main Bluetongue virus vectors in Belgian cowshed
Zimmer, Jean-Yves ULg; Saegerman, Claude ULg; Losson, Bertrand ULg et al

Poster (2012, August)

Bluetongue (BT) is an emerging vectorborne disease of ruminants that was reported in August 2006 in northern Europe. Since 2007, BT virus (BTV) serotype 8 continued its spread across Europe and caused ... [more ▼]

Bluetongue (BT) is an emerging vectorborne disease of ruminants that was reported in August 2006 in northern Europe. Since 2007, BT virus (BTV) serotype 8 continued its spread across Europe and caused considerable economic losses. This observation indicates possible overwintering of the vector from year to year. The biological vectors of BTV are biting midges of the genus Culicoides. Breeding sites of bluetongue vector species have been found near farms (e.g. silage residues) and in neighboring meadows (e.g. cattle dung) but never inside sheds. We conducted a study in five cattle farms in Belgium during February–October 2008. Three samplings were performed and each soil sample collected inside cowsheds was incubated to enable adult midges to emerge. Among 15 soil biotopes sampled, only one showed the emergence of adult Culicoides biting midges: dried dung adhering to walls inside animal enclosures and resulting to the partial removal of used animal litter. It was a breeding site for the C. obsoletus/C. scoticus complex. Physico-chemical characteristics showed that midges of this complex are more prevalent in soil samples with a high carbon:nitrogen (C:N) index. So Culicoides biting midges are able to complete their life cycle in animal enclosures. We identified a breeding site for the primary BTV vector in a cowshed in northern Europe. These observations could explain the persistence of BTV from year to year despite fairly harsh winters. Hygienic measures on farms could reduce biting midges populations and so improve efficacy of vaccination campaigns against BT in Europe. [less ▲]

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See detailEffect of reduced water supply on aphid physiology : A proteomic approach on peach-aphid interaction
Verdugo, Jaime; Lacroze, Jean-philippe; Sauge, Marie-Hélène et al

Poster (2012, August)

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See detailFeeding humans with edible insects : actual state and perspectives in Belgium and Europe
Sablon, Ludovic ULg; Alabi, Taofic; Drugmand, Didier et al

Poster (2012, August)

In future decades, world population will grow up to 9 billion of people and we will be confronted to a lack of nutritive resources. We will not continue to produce proteins with our conventional livestock ... [more ▼]

In future decades, world population will grow up to 9 billion of people and we will be confronted to a lack of nutritive resources. We will not continue to produce proteins with our conventional livestock as beef, poultry or pig. It will therefore look to other sources and edible insects are one of these solutions. Indeed, more than 2000 species of edible insects were actually consumed by 3000 ethnic groups in the world. In undernourished populations, entomophagy is essential to relieve deficiencies in proteins, fatty acids and some vitamins. In Europe, we have acquired sedentary habits and we have lost our ancestral harvesting and hunting traditions. It is the reason of disinterest for edible insects and entomophagy was considered as a "barbarian" food habit. Facing food challenges of tomorrow, it is important to sensitize industrialized populations and to reintroduce edible insects in our plates and habits. The first step is to overcome neophobia of food products. Our studies focused on different insect preparations and on perception of entomophagy by different age classes. Globally, our first results indicated that entomophagy was accepted by belgian consumers but the more difficult for them is to taste the first time. These results confirmed neophobia for this type of food products and thus the importance of positive informations and education for acceptance of entomophagy. [less ▲]

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See detailRole of aphid endosymbionts on virus transmission efficiency
Bosquée, Emilie ULg; Haubruge, Eric ULg; Francis, Frédéric ULg

Poster (2012, July 26)

A large number of phytoviruses are transmitted exclusively by aphids in a circulative manner after transport by the aphid haemolymph to the salivary glands before transmission to new plant short time ... [more ▼]

A large number of phytoviruses are transmitted exclusively by aphids in a circulative manner after transport by the aphid haemolymph to the salivary glands before transmission to new plant short time later. Some proteins, synthesized in aphids by symbiotic bacteria, are hypothesized to bind to virus particles in the haemolymph, to help transfer inside the aphid without any problem and finally promoting viral transmission efficiency. Multiple endosymbionts commonly coexist in the same host insects. The endosymbiotic bacterial partners of aphids fall into two categories: the obligate “primary” symbiont such as Buchnera sp. found in almost all aphids and the facultative “secondary” bacteria that are not always present. Particular associations between aphids and both Buchnera sp. and secondary symbionts well documented according to adaptation to host plant specificity. In contrast, the impact of specific associations between Buchnera and other facultative secondary endosymbionts on the virus transmission is less well understood. In order to understand the role of some ensymbionts associated to the primary one in the PeMV (Pea enation Mosaic Virus) transmission, several Acyrthosiphon pisum clones presenting different patterns of endosymbionts (Buchnera-Serratia, Buchnera-Spiroplasma, Buchnera-Rickettsia), were used in PeMV efficiency transmission assays on broad bean. The PeMV occurrence in plants was tested by enzyme- linked immunosorbent assay technique (ELISA). The higher virus transmission was found when Serratia bacteria was present in the pea aphid. The occurrence of Serratia endosymbiotic bacteria was concluded to be very important in the PeMV transmission. Finally, the aphid symbiont pattern modulation was discussed in multitrophic approach and potential control of aphid and associated dispersion of viral diseases. [less ▲]

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See detailIdentification of bacteria community associated with earthworm gut
Lemtiri, Aboulkacem ULg; Alabi, Taofic; Bodson, Bernard ULg et al

Poster (2012, July 26)

The role of earthworms in soil fertility and transformation of organic waste was regulary cited to be of first importance. Associated to these macro-invertebrates, a large diversity of micro-orgnisms are ... [more ▼]

The role of earthworms in soil fertility and transformation of organic waste was regulary cited to be of first importance. Associated to these macro-invertebrates, a large diversity of micro-orgnisms are found indirectly in their closed environment or directly in their gut. Functional aspects of these interactions and symbiosis in relation with soil characteristics and fertility rates are poorly developed. Here, the micro-organisms diversity and potential related functions of earthworm gut were investigated using a proteiomic approach for both protein and micro-organism identifications. Microbial community investigation was detected by proteomic approach based on bidimensional electrophoresis coupled with mass spectrometry using Matrix Assisted Laser Desorption Ionisation – time of flight (Maldi-Tof). Diversity of gut associated bacterial communities was discussed. Indeed, application of particular crop production practices such as crop residue management at the field level could regulate the gut bacterial communities in earthworm but also microbials in soils. Agricultural systems had to consider the microbial and associated organisms in the soil to enhance fertlility and crop production in sustainable ways. [less ▲]

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See detailA comparison between subjective and objective methods for evaluating the vocal accuracy of a popular song
Larrouy, Pauline ULg; Lévêque, Yohana; Giovanni, Antoine et al

Poster (2012, July 25)

Vocal accuracy of a sung performance can be evaluated by two methods: acoustical analyses and subjective judgements. For one decade, acoustic analyses have been presented as a more reliable solution to ... [more ▼]

Vocal accuracy of a sung performance can be evaluated by two methods: acoustical analyses and subjective judgements. For one decade, acoustic analyses have been presented as a more reliable solution to evaluate vocal accuracy, avoiding the limitation of experts’ perceptive system and their variability. This paper presents for the first time a direct comparison of these methods. 166 occasional singers were asked to sing the popular song « Happy Birthday ». Acoustic analyses were performed to quantify the pitch interval deviation, the number of contour errors and the number of tonality modulations for each recording. Additionally, eighteen experts in singing voice or music rated the global pitch accuracy of these performances. The results showed a high inter-rater concordance within the judges. In addition, a high correlation occurred between acoustic measurements and subjective rating. The total model of acoustic analyses explained 81% of the variance of the judges’ scores. Their rating was influenced by both tonality modulations and interval deviations. This study highlights the congruence between objective and subjective measurements of vocal accuracy while the assessment is done by music or singing voice experts. Our results confirm the relevance of the “pitch interval deviation” criterion in vocal accuracy assessment. Furthermore, the “number of tonality modulations” is a salient criterion in perceptive rating and should be taken into account in studies using acoustical analyses. [less ▲]

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See detailLaser cooling of Iron atoms
Huet, Nicolas ULg; Krins, Stéphanie ULg; Bastin, Thierry ULg

Poster (2012, July 24)

We report on the first laser cooling of Iron atoms. Our laser cooling setup makes use of 2 UV laser radiation sent colinearly in a 0.8 m Zeeman slower. One laser is meant for optical pumping of the Iron ... [more ▼]

We report on the first laser cooling of Iron atoms. Our laser cooling setup makes use of 2 UV laser radiation sent colinearly in a 0.8 m Zeeman slower. One laser is meant for optical pumping of the Iron atoms from the ground state to the lowest energy metastable state. The second laser cools down the atoms using a quasi-perfect closed transition from the optical pumped metastable state. The velocity distribution at the exit of the Zeeman slower is obtained from a probe laser crossing the atom beam at an angle of 50 degrees. The fluorescence light is detected using a photomultiplier tube coupled with a boxcar analyzer. The Iron atom beam is produced with a commercial effusion cell working at around 1950 K. Our laser radiations are stabilized using standard saturated-absorption signals in both an Iron hollow cathode absorption cell and an Iodine cell. We will present our experimental setup, as well as the first evidences of cooled down Iron atoms at the exit of the Zeeman slower. [less ▲]

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See detailValidation of ACE-FTS using ground-based FTIR measurements of CFC-11, CFC-12 and HCFC-22
Kolonjari, F.; Mahieu, Emmanuel ULg; Walker, K.A. et al

Poster (2012, July 24)

Satellite data can be an effective global monitoring tool for long-lived compounds in the atmosphere. The Atmospheric Chemistry Experiment (ACE) is a mission on-board the Canadian satellite SCISAT. The ... [more ▼]

Satellite data can be an effective global monitoring tool for long-lived compounds in the atmosphere. The Atmospheric Chemistry Experiment (ACE) is a mission on-board the Canadian satellite SCISAT. The primary instrument on SCISAT is a high-resolution infrared Fourier Transform Spectrometer (ACE-FTS) which is capable of measuring a wide range of gases including key chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) species. These families of species are of interest because of their significant contribution to anthropogenic ozone depletion and to global warming. To assess the quality of data derived from satellite measurements, validation using other data sources is critical. Ground-based Fourier transform infrared spectrometers (FTIRs) are particularly useful for this purpose. In this study, five FTIRs located at four sites around the world are used to validate the CFC- 11, CFC-12, and HCFC-22 data products from ACE-FTS. These species are related; HCFC-22 was the primary replacement for CFC-11 and CFC-12 in refrigerant and propellant applications. The five FTIR instruments used in this study record solar absorption spectra at Eureka, Canada, Jungfraujoch, Switzerland, Poker Flat, USA, and Toronto, Canada. Details on the instrumentation at each site will be provided. The retrieval of CFC-11, CFC-12, and HCFC-22 are not standard products for many of these FTIRs, and as such, the initial stage of this study is to develop the retrieval of each species. Harmonization of retrieval parameters between the sites is an important step in this process. The development of these retrievals and preliminary results will be presented. Additionally, a new method for the validation of ACE-FTS measurements will be discussed. [less ▲]

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See detailThe Metagenomic in the Service of the Food Microbiology.
Taminiau, Bernard ULg; Nezer, Carine; Poullet, Jean-Baptiste et al

Poster (2012, July 23)

Introduction: Food products represent great biotopes for bacteria. The optimisation of foodstuffs conservation, mattering so economically as from the point of view of the public health, pass by a better ... [more ▼]

Introduction: Food products represent great biotopes for bacteria. The optimisation of foodstuffs conservation, mattering so economically as from the point of view of the public health, pass by a better understanding of those biotopes and their spoilage. Microbiologists had already tried to resolve this problem throughout several approaches. Studies based on classical microbiology cultures were completed by strategies centred on approaches independent from the microbiological culture. Purpose: The current techniques of new generation sequencing give a new dimension to the microbial ecology, through the metagenomic analysis of individuals' large number, within a mixed microbial population. Our aim is to demonstrate that this methodology can be successfully applied to the study of foodstuffs microbial flora, and can be adapted to the specific requirements of food microbiology. Methods: This study was carried out on pork's minced meat and white sausage, with shelf-life tests in various conditions of preservation (temperature and packaging). The rDNA 16S was extracted from the original products and samples in the best-before date and, after standardization, hypervariable regions V5 were sequenced. Results: A total about 130.000 sequences were obtained and a metagenomic analysis succeeded in the taxonomic classification to the genus level for 80 % of this population. The subsequent analysis of microbial populations shows that the majority microbial populations at the expiration date are the same ones which are generally observed during microbiological analysis of these meat products. However, the population subdominants and especially several populations of not cultivable germs were able to be identified. These groups of bacteria, more difficult to obtain by the other methods, must be studied because they participate in the spoilage process of food products. Significance: The sensibility of this technology makes possible the analysis of foodstuffs presenting a very low microbial rate and, thus, allows the identification of the microbial contaminants before they grow the levels detected by cultural methods. [less ▲]

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See detailAn effective Real-time Quantitative PCR protocol for quantification of pathogens in foodstuffs
Adolphe, Y.; Crevecoeur, Sébastien ULg; Duval, P. et al

Poster (2012, July 22)

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See detailImpact of Myzus persicae infestation on the volatile emission of Arabidopsis thaliana Col-0.
Hien, Truong Thi Dieu ULg; Delaplace, Pierre ULg; Francis, Frédéric ULg et al

Poster (2012, July 22)

Being members of complex communities, plants often emit a wide range of volatile organic compounds to defend themselves against insect invasions. Although many studies exist on insect-induced plant ... [more ▼]

Being members of complex communities, plants often emit a wide range of volatile organic compounds to defend themselves against insect invasions. Although many studies exist on insect-induced plant volatile emission, most of them either compare the influences of various herbivore species on one plant species or the impact of a given herbivore on several host plant species. Moreover, informations related to the influence of insect density as well as the infestation duration are still needed. Here, we showed that a sucking insect – Myzus persicae (green peach aphid) induced the volatile emission from Arabidopsis thaliana Columbia wild-type (A.thaliana Col-0) under laboratory conditions based on results obtained by solid-phase micro-extraction coupled with gas chromatography - mass spectrometry (SPME-GC/MS). The released volatile blend was discussed in relation to related biosynthesis pathways and functions. These included terpenoids, green leaf volatiles, alcohols and isothiocyanate. The qualitative and overall proportion of volatile components differed depended on the number and residence duration of aphids on leaves. By studying the effects of sucking insect stresses to plant, we not only aim to contribute to the fundamental understanding of the emission of volatile components in the interaction between plants and pests, but also to provide standardised and easy to use assays to assess A.thaliana volatile changes according to cross stresses, including both biotic and abiotic ones in ongoing experiments. [less ▲]

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See detailPrevious errorless sequence-learning promotes subsequent SRT performance in patients with Alzheimer's Disease
Schmitz, Xavier ULg; Bier, Nathalie; Joubert, Sven et al

Poster (2012, July 17)

Motor-learning capacities are known to be relatively preserved in Alzheimer's disease (AD), which is crucial in the context of the patient’s autonomy (e.g., Rouleau et al., 2002). However, it is important ... [more ▼]

Motor-learning capacities are known to be relatively preserved in Alzheimer's disease (AD), which is crucial in the context of the patient’s autonomy (e.g., Rouleau et al., 2002). However, it is important to determine the most appropriate techniques for such learning. In AD, implicit or procedural rehabilitation techniques would be more effective to train new skills than explicit or declarative learning methods (van Halteren-van Tilborg, 2007). Maxwell et al. (2001) showed that reducing errors during motor learning minimizes the building of declarative knowledge and would allow implicit knowledge accumulation. If errorless learning induces the formation of an implicit knowledge, this technique appears to be adapted to the learning of a perceptual-motor skill in patients with impaired controlled processes. Very few studies have investigated errorless learning in procedural learning situations, even though some data suggest that errorless learning would be efficient for learning instrumental activities of daily living (e.g., Thivierge et al., 2008). In this study we examined the acquisition of a new perceptual-motor skill in 12 patients with AD and 12 healthy older adults. We compared the impact of two preliminary sequence learning conditions (errorless vs. errorful) on a serial reaction time (SRT) performance. In SRT, the subject must react as quickly as possible to the appearance of a target on a screen by pressing the key corresponding to the position of the stimulus. The effectiveness of learning is demonstrated by a reaction time improvement when the target follows a repeating sequence. For patients with AD, results confirm that the advantage provided by prior learning occurs only in the errorless condition whereas both learning modes improve SRT performance in healthy participants. In conclusion, these results confirm that the errorless learning promotes the development of implicit knowledge and appears to be an effective method for procedural learning in Alzheimer's disease. [less ▲]

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See detailSimultaneous versus solitary pharmacological manipulation of NMDA- and AMPA- receptors: effects of new drugs on contextual learning and its extinction
Vignisse, Julie ULg; Steinbusch, Harry W.M.; Griegoriev, Vladimir et al

Poster (2012, July 17)

Both the attenuation of the NMDA-receptor mediated transmission via low affinity blockade mechanism, and the stimulation of AMPA receptor-mediated signaling were shown to result in beneficial ... [more ▼]

Both the attenuation of the NMDA-receptor mediated transmission via low affinity blockade mechanism, and the stimulation of AMPA receptor-mediated signaling were shown to result in beneficial neurobiological effects, such as an enhancement of memory and neurogenesis. We aimed to compare the effects of acute pharmacological manipulations of these mechanisms, exerted simultaneously or solely in mice, on learning of two mouse tasks with distinct predominant dependency on either glutamate receptor subtype. In a step-down avoidance task, memantine, low affinity NMDA receptor blocker (5 mg/kg), but not ampakine QQX (5 mg/kg) increased memory scores. In contrast, extinction of contextual fear conditioning was significantly enhanced by the latter, but not by the first drug. Among four new isothiourea derivates used at the doses 0.5-1 mg/kg, one compound that showed a maximal potency with respect to both glutamatergic mechanisms, as well as dimebon (1 mg/kg), had the most prominent memory enhancing effects. Thus, simultaneous low affinity blocade of the NMDA receptor and stimulation of AMPA-mediated transmission can result in eminent pro-cognitive activities. These data point to the importance of multi-target drug mechanism in the regulation of cognitive functions and suggest its potential for clinical implications. [less ▲]

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See detailLearning and Error Reproduction in Alzheimer Disease
Wansard, Murielle ULg; Erkès, jérôme; Adam, Stéphane ULg et al

Poster (2012, July 15)

Alzheimer disease (AD) is characterized by an early impairment of explicit memory processes associated to a preservation of implicit memory processes (Fleischman & Gabrieli 1998). Due to the role of ... [more ▼]

Alzheimer disease (AD) is characterized by an early impairment of explicit memory processes associated to a preservation of implicit memory processes (Fleischman & Gabrieli 1998). Due to the role of explicit memory in the suppression of errors during learning, AD patients tend to reproduce automatically (implicitly) errors that occurred during a previous learning (Baddeley & Wilson, 1994). Consequently, errorless learning should be more efficient than a classical “trial-and-error” procedure for AD patients. Indeed, errorless learning decreases the involvement of (impaired) explicit memory by avoiding the interference caused by the production of errors (Bier et al., 2002). The present study investigates the automatic post-learning error production in mild AD patients and matched control subjects by using a word stem completion task (Adam et al., 2005) in conditions of both errorless and trial-and-error learning. Results showed a lower word stem completion performance in mild AD than control subjects, but a similar performance in the patients’ group for the two learning conditions. Moreover, in the trial-and-error procedure, the errors consisted mainly in erroneous responses already produced during the learning phase. In addition, correlation analyses indicate that the ability to suppress errors in the trial-and-error learning condition in mild AD patients is subtended by the efficiency of episodic memory processes, but not by inhibitory abilities. These results suggest that the errorless procedure improves the quality of learning of mild AD patients (production of fewer errors) but do not influence the learning rate per se. [less ▲]

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See detailThe acquisition of new orthographic representations among dyslexic children
Binamé, Florence ULg; Defraigne, Aurélie; Poncelet, Martine ULg

Poster (2012, July 14)

Purpose – In developmental dyslexia, spelling deficits have been much less explored than reading deficits, although the former tend to be more persistent than the latter. The aim of this study was to ... [more ▼]

Purpose – In developmental dyslexia, spelling deficits have been much less explored than reading deficits, although the former tend to be more persistent than the latter. The aim of this study was to explore the ability to acquire new orthographic representations through different learning conditions in dyslexic children. Method – Fifteen dyslexic French-speaking children (mean chronological age: 11; 4 years; mean reading age: 7; 6 years), 15 chronological age (CA) and 15 reading age (RA) matched controls participated in the study. Their ability to acquire new orthographic representations was assessed through different learning conditions: isolated pseudowords decoding, text reading with embedded target pseudowords and writing of pseudowords after presentation in their visual form associated or not to a semantic representation. In each condition, ten target pseudowords were presented six times. Orthographic learning was measured by a dictation of the targets immediately after the learning session and one week later. Results – Orthographic learning of dyslexics was significantly impaired and decreased more over time relative to CA group but not to RA group. Otherwise, dyslexics, as other groups, performed better when learning conditions consisted in writing pseudowords than in decoding them. Furthermore the condition associating a semantic representation to the pseudowords did not enhance the performances in any group. Conclusion – These results confirm that decoding abilities are essential to develop orthographic representations and suggest that writing is a powerful learning mechanism in dyslexic as in normal readers. By contrast, a semantic representation seems not to support the development of orthographic representations. [less ▲]

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See detailInversion of multi-temporal geoelectrical field data sets: insights on noise characterization and regularization
Nguyen, Frédéric ULg; Kemna, Andreas; Robert, Tanguy ULg et al

Poster (2012, July 11)

Inversion of geoelectrical time-lapse data sets is increasingly growing as monitoring systems are being used in more applications such as seawater intrusion, landslides, remediation of contaminated sites ... [more ▼]

Inversion of geoelectrical time-lapse data sets is increasingly growing as monitoring systems are being used in more applications such as seawater intrusion, landslides, remediation of contaminated sites, landfill operation, shallow geothermal systems, or management of water resources. To date, several inversion strategies exist for taking into account the temporal dimension of the data. The most used nowadays are the independent inversion of multi-temporal data sets, the difference inversion, the temporally-constrained inversion, and the more recent process-based inversion. However, difference inversion schemes generally assume that part of the noise contained in the data cancels out when working with temporal data differences. Temporally-constrained inversion on the other hand assumes that the changes are localized and minor. Process-based inversion requires a more advanced knowledge of the system prior the inversion. In this study we demonstrate that the resolution of the time-lapse inversion scheme is mostly dependent on the quantification of the temporal behavior of the data error, on the resolution of the model-dependent pattern of the survey, and not on the regularization strategy. Our study is based on the imaging results of different data sets with different time and spatial scales, and with different degrees of geological complexity and resistivity contrast, The considered sites are a shallow sandy aquifer and a fractured hard rock aquifer where tracer experiments were performed and monitored using surface arrays. The two studied transport processes are advection, with velocities on the order of 10 m/hour and slower advection/diffusion processes. The strongest improvements were brought by using the data difference and a quantitative estimation of the data error. We found in particular a dependence of the time-lapse data error to the measured resistance (i.e., signal-to-noise-ratio), permitting to formulate an error model to describe the data error present in time-lapse data sets. We used minimum gradient support regularization to invert for model changes with enhanced contrast and found this technique more suited to time-lapse studies than for static images. Noise characterization and error models appear therefore as essential and the most impacting for a successful inversion both for static and time-lapse data whereas different spatio-temporal regularization techniques allowed to decrease artefacts but needs to be coherent with the process. [less ▲]

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See detailOcean bomb radiocarbon sink: an elusive problem?
Mouchet, Anne ULg

Poster (2012, July 10)

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See detailOur soil map as cultural heritage: what of the Belgium soil survey project should be preserved and what is being lost?
Legrain, Xavier ULg; Dondeyne, Stefaan; Deckers, Jozef et al

Poster (2012, July 06)

Between 1947 and 1991, soils of Belgium were mapped to establish a systematic inventory of the country soil resources. Field observations were done by soil auger to a standard depth of 1.25 m and at a ... [more ▼]

Between 1947 and 1991, soils of Belgium were mapped to establish a systematic inventory of the country soil resources. Field observations were done by soil auger to a standard depth of 1.25 m and at a mean density of 2 points per hectare. Cadastral plans at scale 1:5,000 where used for georeferencing field observations and for delimiting map units, subsequently generalized on the 1:10,000 topographic base map. The final map was published on sheets at scale 1:20,000 along with descriptive texts. Besides, data on about 15,000 described and analyzed soil profiles were reported in technical annexes. With the advent of computers, data on soil profiles have been transfered into relational databases and soil sheets have been digitized. Coding of the data rendered them more accessible, but inevitably implied a standardization and hence a reduction of some information. Still most of the soil surveyors have already passed away, besides their intangible expert knowledge, a wealth of information is also being lost when their field notes, unpublished reports, minutes of meetings and draft maps are being disregarded. The map legend was developed during the first decade of the survey, reflecting state of knowledge on soil formation and their relative importance for agricultural land-use in the 1950s. To guarantee that future generations will be able to appreciate the value and concepts underpinning the soil information, it is important that at least a minimum set of such historical documents would be preserved, analyzed and documented. [less ▲]

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See detailMultiscale modelling of the influence of VEGF on sprouting angiogenesis.
Carlier, Aurélie ULg; Geris, Liesbet ULg; Van Oosterwyck, Hans

Poster (2012, July 06)

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See detailResorcinol-formaldehyde carbon xerogels as lithium-ion battery anode materials: influence of porosity on capacity and cycling behaviour
Piedboeuf, Marie-Laure ULg; Léonard, Alexandre ULg; Khomenko, Volodymyr et al

Poster (2012, July 05)

Carbon xerogels are promising candidates in the development of new high performance C-based anode materials for Li-ion batteries. Indeed, their specific capacities widely exceed that of conventional ... [more ▼]

Carbon xerogels are promising candidates in the development of new high performance C-based anode materials for Li-ion batteries. Indeed, their specific capacities widely exceed that of conventional graphitic structures, and they can be intercalated/deintercalated in a low-cost electrolyte based on propylene carbonate (PC), which has an excellent conductivity at low temperatures. In addition, such carbonaceous materials show very small changes of volume during the charge/discharge, providing a long cycle life of such an anode. 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[1]. To reduce these disadvantages, the structural and textural characteristics need to be carefully controlled. Porous carbon xerogels can easily be prepared from resorcinol-formaldehyde aqueous mixtures, which are polymerized, dried and pyrolysed. The porosity of these xerogels is mainly governed by the pH of the precursor solution as well as by the drying procedure. Globally, these materials are composed of microporous nodules delimiting meso- or macroporous voids, the size of which is adjusted via the synthesis pH. Too a high microporosity can induce considerable irreversible capacity losses and too small mesopores may hinder the proper chemical diffusion of lithium ions within a bulk electrode material. The latter is often a rate-limiting step and optimized transport pathways could be provided by creating large mesopores or even macropores within the microporous carbon [3]. Here we report on the preliminary electrochemical characterization of porous carbon xerogels prepared by vacuum drying procedure. By adjusting the pH of the precursor solution, the materials obtained develop low to high values of specific surface areas and exhibit homogeneous pore sizes that range from several microns to several nanometers. The electrochemical performance of these materials as electrode compounds was tested by galvanostatic charge-discharge of 16-mm disc electrodes assembled in CR2016 coin cells or of 13-mm disc electrodes in home-made Swagelok-type cells. The first results show that all the samples show quite a high irreversible capacity during the first cycle; this irreversible capacity is proportional to the specific surface area. Its value nevertheless remains quite low for the low-surface area macroporous sample. The latter also shows the best reversible capacity after the second cycle, with values approaching that of commonly used graphite. For example, when cycled at a rate of C/20 for 10 cycles, this sample showed a capacity of 320 mAh/g; the value was kept at 200 mAh/g when increasing the rate up to C/5. The long-term cycling performance was investigated by cycling the anodes at C/20 and C/5. Again, the macroporous sample behaves best, with superior capacity retention and invariable discharge capacity of ~175 mAh/g after more than 100 cycles. The electrochemical properties of carbon xerogels was evaluated in the conditions which are used typically for graphite (cycles in the potentials range from 0.003 to 1.5 V vs. Li+/Li). A higher reversible capacity of 400 mAh/g could be obtained for the macroporous sample using a discharge with plating of Li as described in [4], but this method could not be accepted in the case of Lithium-ion batteries. These first results show that carbon xerogels are very promising candidates as anode materials for Li batteries, providing the textural characteristics are carefully controlled. The ongoing work is dealing with the establishment of possible relationships between textural features and electrochemical performance in order to shed light on the requirements that will dictate the best synthesis procedures. References: [1] T. Tran, B. Yebka, X. Song, G. Nazri, K. Kinoshita and D. Curtis, J. Power Sources, 85, 269, 2000. [2] N. Job, A. Théry, R. Pirard, J. Marien, L. Kocon, J.-N. Rouzaud, F. Béguin and J.-P. Pirard, Carbon 43, 2481, 2005. [3] F. Cheng, Z. Tao, J. Liang, and J. Chen, Chem. Mater., 20, 667, 2008. [4] W. Xing, J. S. Xue, J.R. Dahn, J. Electrochem. Soc, 143, 3046, 1996. [less ▲]

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See detailBehavioural effects of approach-avoidance motivational conflicts in Zebrafish: testing an Attentional Control Model on videotracked swimming activity
Ylieff, Marc ULg; Froidbise, Sophie; Jacquet, Laurie et al

Poster (2012, July 05)

Motivational conflicts have been thoroughly studied in birds and mammals over the last decades, but their investigation has remained anecdotic with respect to fish. However, recent researches reveal that ... [more ▼]

Motivational conflicts have been thoroughly studied in birds and mammals over the last decades, but their investigation has remained anecdotic with respect to fish. However, recent researches reveal that, emotion and cognition also play a pivotal role in the expression of fish behaviour. Fish exhibit fear, long-term memory, attentional and learning capacities that are comparable with those of other vertebrates, including nonhuman primates. Thus, fish can be expected to manage motivational conflicts using cognitive similar resources. As many other teleost fishes, zebrafish (Danio rerio) is a good candidate to investigate the behavioural effects of approach–avoidance conflicts because of its genetic and neurophysiological proximity with “higher” vertebrates. The present study aims to determine how Zebrafish reacted to threats of different magnitude (low vs. high) following the delivery of food. [less ▲]

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See detailFunctional study of Arabidopsis thaliana ASF/SF2-like pre-mRNA SR splicing factors
Stankovic, Nancy ULg; Tillemans, Vinciane; Leponce, Isabelle et al

Poster (2012, July 04)

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See detailEnteroendocrine cells ontogenesis in zebrafish
Stern, David ULg; Voz, Marianne ULg

Poster (2012, July 04)

Endocrine cells of the digestive tract include pancreatic cells clustered in the islets of Langerhans and the enteroendocrine cells, scattered throughout the digestive epithelium. Notch pathway plays a ... [more ▼]

Endocrine cells of the digestive tract include pancreatic cells clustered in the islets of Langerhans and the enteroendocrine cells, scattered throughout the digestive epithelium. Notch pathway plays a crucial role in endocrine cell fate determination and mediates cell fate decisions. The goal of this project is to decipher the molecular cascade triggered by Notch signaling that controls the endocrine cell differentiation in the digestive system. The targets of Notch signaling are usually members of the bHLH family and more precisely of the Achaete scute-like (Ascl) family or of the atonal related proteins (ARP) family. In this study, we searched for all ARP and Ascl factors expressed in the endocrine lineage of the pancreas and in the gastrointestinal tract in zebrafish.   [less ▲]

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See detailConverting the legend of the Soil Map of Belgium into the World Reference Base for Soil Resources: Lessons from correlating national soil survey data to an international soil classification system
Bouhon, Antoine; Dondeyne, Stefaan; Legrain, Xavier ULg et al

Poster (2012, July 03)

Soils in Belgium were mapped between 1947 and 1991 and published at a 1:20000 scale. These maps are used in land consolidation projects and for assessing soils’ vulnerability to erosion and pollution ... [more ▼]

Soils in Belgium were mapped between 1947 and 1991 and published at a 1:20000 scale. These maps are used in land consolidation projects and for assessing soils’ vulnerability to erosion and pollution. Integration of land-use and environmental policies within the European Union however requires a harmonization of different national soil classification systems. With the World Reference Base for Soil Resources (WRB) as common classification system within the Union, the authorities of Flanders and Wallonia commissioned a study to elaborate a methodology for converting the Belgian soil legend into WRB. The Belgian legend is based on field properties such as texture, drainage status and profile development. The WRB classification is based on diagnostic features defined by morphological, physical and chemical properties. A key and software programme have been developed to convert the Belgian units into WRB units. However, as many Belgian units could not unequivocally be translated into WRB units, additional guidelines had to be derived based on soil survey data classified according to WRB. The data show that principles of the legend shifted over time or were interpreted differently to take regional specificities into account. To overcome resulting ambiguities it is proposed to establish a database of reference soil profiles. Whereas, overall WRB is satisfactory for classifying soils at national level, the experience also shows that some WRB concepts may benefit from revisions to facilitate its correlation with national soil survey data. [less ▲]

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See detailHydrological instrumentation of a pilot catchment in view to improve the soil loss modeling: focus on the spatial distribution of erosion and deposition (loamy region, Belgium)
Pineux, Nathalie ULg; Degré, Aurore ULg

Poster (2012, July 02)

Nowadays, lots of catchments are affected by inundations or mudflows which are the consequences of excessive runoff and accelerated erosion. That generates also a significant loss of arable land. Yet, the ... [more ▼]

Nowadays, lots of catchments are affected by inundations or mudflows which are the consequences of excessive runoff and accelerated erosion. That generates also a significant loss of arable land. Yet, the soil resource is not an unlimited commodity. Moreover, sediments’ transfer to watercourses alters their physical and chemical quality. The watershed management should aim at both limiting erosion and enhancing deposition in appropriate zones. Therefore, the global objective of this work is to acquire hydropedological data in order to better quantify the erosion and deposition phenomenon in Belgium. The poster presents the field monitoring put in place in our experimental watershed. Indeed, observed quantitative data are essential but still limited. Particularly, we lack observations spatially distributed on the watershed. The watershed is a 124 ha agricultural zone in the loamy region. Its slopes range from 0% to 9%. Instrumentation includes a weather station with disdrometer, discharge measurement at the outlet coupled with water sampling. Fields observations are done to determine the texture redistribution and compared with a previous soil survey realised in 1958. Moreover, regular flights above the area will allow us to obtain a very accurate DEM using Lidar technology (5cm pixel) and observing the relief evolution. The CAESAR model will be tested on this watershed. It aims at representing both erosion and sedimentation and estimates the net erosive flows. This model is based on the Einstein-Brown equations and needs an initial digital elevation model, hourly rainfalls, soil texture, etc. It produces a digital elevation models’ evolution through time. [less ▲]

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See detailImpact of soil management on earthworm diversity according to differential plowing and plant residue incorporation
Lemtiri, Aboulkacem ULg; Alabi, Taofic; Zirbes, Lara ULg et al

Poster (2012, July 02)

Earthworms are largely distributed in terrestrial ecosystems and their abundance and diversity in soils are significantly affected by biotic (macro- and micro-organisms) and abiotic factors: soil ... [more ▼]

Earthworms are largely distributed in terrestrial ecosystems and their abundance and diversity in soils are significantly affected by biotic (macro- and micro-organisms) and abiotic factors: soil properties (pH, texture, structure…); agricultural management system and climate change. Here, tillage effect of earthworm population combined with crops residual management was investigated and correlated with soils properties. From wheat experimental field plots, the diversity of earthworm according to the field crop management was assessed. Application of particular crop production practices such as the integration of different levels of crop residues, diverse parts of wheat straws, at the field level regulate earthworm diversity and population abundance. Indeed, tillage reduced earthworm population with a 35% rate also corresponding to changes in soil properties. Agricultural practices had to be adapted to include consideration on macro-invertebrate abundance and diversity to maintain efficient soil fertility and allow sustainable crop production [less ▲]

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See detailModeling of the Diffusion of VOCs Emitted by Barley Roots
Hirtt, Laura ULg; Destain, Marie-France ULg; Lognay, Georges ULg et al

Poster (2012, July 02)

Detailed reference viewed: 52 (21 ULg)
See detailModeling argon dynamics in first-year sea ice
Moreau, S.; Vancoppenolle, M.; Tison, J.-L. et al

Poster (2012, July)

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See detailEffects of tree species diversity on earthworm communities in European forests
de Wandeler, Hans; Ottoy, Sam; Hermy, Martin et al

Poster (2012, July)

The belowground food web holds a big part of the associated biodiversity in forest ecosystems and plays a major role in essential ecosystem processes, e.g. litter decomposition and nutrient turnover. So ... [more ▼]

The belowground food web holds a big part of the associated biodiversity in forest ecosystems and plays a major role in essential ecosystem processes, e.g. litter decomposition and nutrient turnover. So far, important interactions between diversity and composition of above-and belowground food webs have been observed. However the effects of tree species diversity on the belowground food web are so far not conclusive. This study aims at elucidating the effect of tree species mixtures, species diversity and trait diversity on the composition of the earthworm communities in European forests. Experimental platforms of planted tree species diversity assemblages in Finland (Satakunta) and Germany (Biotree) are therefore intensively sampled for earthworms using the combined mustard extraction/hand sorting method. First results are reported and discussed and diversity effects are evaluated with overyielding tests. [less ▲]

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See detailRadial arm maze as a new paradigm to study collective behaviours in fish
Delcourt, Johann ULg; Garnier, Simon; Miller, Noam Y. et al

Poster (2012, July)

Collective decision-making is based on both environmental information perceived by individuals and social interactions with other group members. Determining and analyzing separately both interactions is a ... [more ▼]

Collective decision-making is based on both environmental information perceived by individuals and social interactions with other group members. Determining and analyzing separately both interactions is a real challenge. If the environmental influences on group behaviours can be determined, new possibilities to collect information about processes inside the group become possible. To improve our knowledge of these processes, an experiment where collective decision-making can be measured easily and without any ambiguity is needed. For this perspective, a new paradigm in the study of collective behaviour is introduced here. The radial arm maze is a classical method used to study individual cognitive abilities. Its advantages are firstly to allow control of environmental information; secondly, to realize multi-way tests, and thirdly, to give the opportunity to collect categorical responses like presence/absence. We apply this paradigm for the first time to a whole animal group. We have also developed an image analysis system able to automatically count the number of individuals in every defined zone. Due to this counting, the degree of cohesion, the group stability, the activity and zone preferences can be described as function of factors such as the group size, the defined zones, or the experimental time. The degree of cohesion can be measured by a new index taking into account the number of sub-groups and the size of each ones. Group activity can be measured by the movement of the majority group between arms. This activity allows determining exploratory processes but also whether zone preferences or homing phenomena appear in the absence of any stimulus. To illustrate, our first results from the exploratory behaviour study of shoals of golden shiners (Notemigonus crysoleucas) are introduced. Using this new paradigm, it is now possible to quantify rapidly in a standardised way the collective responses of fish shoals according to the absence or presence of environmental stimuli, and to create experiments where environmental information is controlled. [less ▲]

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See detailCalculation of Thermoelectric Properties from First-Principles
Xu, Bin ULg; Verstraete, Matthieu ULg

Poster (2012, July)

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See detailFlexible aggregative behavior of Harmonia axyridis according to the freshness of area marking in overwintering sites
Durieux, Delphine ULg; Fischer, Christophe ULg; Fassotte, Bérénice ULg et al

Poster (2012, July)

The multicolored Asian ladybeetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), aggregates inside dwellings and buildings during winter to survive cold. This adaptive behavior causes annoyances ... [more ▼]

The multicolored Asian ladybeetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), aggregates inside dwellings and buildings during winter to survive cold. This adaptive behavior causes annoyances to the occupants because of their large number and the induction of allergic reactions. Although this species has aroused a great interest these last years, the factors involved in the selection of its overwintering sites remain misunderstood. The work presented herein was oriented to the study of the non-volatile chemical compounds involved in this aggregation behavior. Chemical analyses revealed the occurrence, in aggregation sites, of an area marking made up of saturated and unsaturated hydrocarbons. Behavioral investigations demonstrated that H. axyridis preferentially aggregates in sites previously marked by congeners, indicating the retention potential of this blend on overwintering individuals. In the second instance, the same analyses were performed on an area marking aged of one year. The chemical investigations showed that only saturated hydrocarbons can still be detected after that period of time but the remaining blend does not induce aggregation anymore. This difference of response according to the freshness of the area marking suggests that this species would not be prisoner of the marking previously deposited on the substrate if the surrounding has changed and the site is not suitable anymore. [less ▲]

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See detailGenomic selection and scan for major genes for a new lamb survival trait for the New Zealand sheep industry
Auvray, Benoit; Vanderick, Sylvie ULg; Newman, Sheryl-Anne et al

Poster (2012, July)

Lambing percentage is one of the most significant factors affecting profitability on New Zealand sheep farms. Since the early 1990s, lambing percentage has increased at about 1% per year from a relatively ... [more ▼]

Lambing percentage is one of the most significant factors affecting profitability on New Zealand sheep farms. Since the early 1990s, lambing percentage has increased at about 1% per year from a relatively stable level of approximately 100%, and top performing sheep farms are now consistently achieving 150% or more. As lambing percentage increases, the proportion of ewes bearing twins and triplets increases accordingly. Lamb mortality rate in these multiples is higher than in singles, with triplets being particularly susceptible. Consequently, lamb survival has become increasingly important to the New Zealand sheep industry. Sheep Improvement Ltd. (SIL, New Zealand’s national sheep genetic evaluation system owned by Beef + Lamb NZ) records lamb survival to weaning but genetic improvement has been limited due to the low heritability of the trait and the current method of recording. To address those issues, we have developed an improved survival to weaning trait for industry implementation, which is more accurate and more heritable than the current SIL trait. This poster will present results of applying genome-enabled prediction procedures to the new trait to obtain molecular breeding values. It will also describe results from a genome wide association study using the new trait. [less ▲]

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See detailSimulations of the Antifungal Lipopeptide Mycosubtilin in Langmuir Monolayers of Sterols
Loison, Claire; Nasir, Mehmet Nail ULg; Besson, Françoise

Poster (2012, July)

Detailed reference viewed: 16 (1 ULg)
See detailHepatitis E virus infection of wild boar (Sus scrofa) in southern Belgium.
Thiry, Damien ULg; Mauroy, Axel ULg; Brochier, Bernard et al

Poster (2012, July)

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See detailAntarctic Microbial BIOdiversity : the importance of geographical versus ecological factors
Obbels, Dagmar; De Carvalho Maalouf, Pedro ULg; De Wever, Aaike et al

Poster (2012, July)

Antarctica is a prime region to test whether microbes have a biogeography and to study their metacommunity dynamics, because (i) it is isolated from the other continents, (ii) its extreme environmental ... [more ▼]

Antarctica is a prime region to test whether microbes have a biogeography and to study their metacommunity dynamics, because (i) it is isolated from the other continents, (ii) its extreme environmental conditions allow microorganisms to dominate its ecosystems, and (iii) lacustrine and terrestrial habitats occur isolated in a matrix of ice and ocean. We compiled a large set of samples from benthic microbial mats from Antarctic lakes in different ice-free regions and used a polyphasic approach to study their microbial biodiversity by combining morphological characterization of diatoms with molecular techniques such as Denaturing Gradient Gel Electrophoresis (green algae and cyanobacteria), 454 pyrosequencing and cultivation (prokaryotes). [less ▲]

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See detailEffects of cold temperatures on the early stages of maize inbreds
Riva-Roveda, Laetitia ULg; Escale, Brigitte; Giauffret, Catherine et al

Poster (2012, July)

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See detailClimate change simulation in continental Antarctica using Open-Top Chambers
Mano, Marie-José ULg; Namsaraev, Zorigto; Gorodetskaya, Irina et al

Poster (2012, July)

In continental Antarctica, the environnmental conditions are extreme and only microbial organisms can withstand them. Currently, the majority of OTCs experiments are being held in Maritime Antarctica but ... [more ▼]

In continental Antarctica, the environnmental conditions are extreme and only microbial organisms can withstand them. Currently, the majority of OTCs experiments are being held in Maritime Antarctica but it would be interesting to have such data for the continental part of Eastern Antarctica. To monitor the response of the microbial communities to local simulations of climate change, 8 Open-Top Chambers (OTC) were installed close to the Princess Elisabeth station, in the Sor Rondane Mountains in January 2010. They are located on the Utsteinen ridge, the Tanngarden granite outcrop, the Teltet nunatak and the fourth nunatak of the Pingvinane range. In each location, two OTCs and a control area were established. Temperature and humidity loggers were installed inside the OTCs and outside, in the control areas, to estimate the environmental changes induced by the OTCs. [less ▲]

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See detailComparison of Staphylococcus aureus strains isolated from bovine mastitis
Bardiau, Marjorie ULg; Duprez, Jean-Noel; Mainil, Jacques et al

Poster (2012, July)

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See detailNon-invasive monitoring of mixed cropping systems. A case-study in Ratchaburi province, Thailand
Garré, Sarah ULg; Coteur, Ine; Diels, Jan et al

Poster (2012, July)

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See detailPhenolic compounds in apple juices - Method of quantification by UHPLC-UV and UHPLC-MS/MS
Verdu, Cindy ULg; Gatto, Julia; Freuze, Ingrid et al

Poster (2012, July)

An UPHLC-UV/MS/MS method was developed for separation and quantification of major polyphenolic compounds present in apple juice. The main classes of polyphenols studied here are monomeric or polymeric ... [more ▼]

An UPHLC-UV/MS/MS method was developed for separation and quantification of major polyphenolic compounds present in apple juice. The main classes of polyphenols studied here are monomeric or polymeric flavan-3-ols, phenolic acids, flavonols and dihydrochalcones. compounds were quantified simultaneously with the two detection systems, i.e. with UV-PDA detection and ESI-triple quadrupole mass detection used in the selected reaction monitoring (SRM) mode. Each method (UHPLC-UV and UHPLC-SRM) was assessed with 2 different apple juice samples and linearity, limit of detection and quantification (LOD and LOQ), accuracy and precision tests were realized on the 15 major compounds. Despite the validation of the UHPLC-UV and UHPLC-SRM methods, significantly different results were obtained by comparing UHPLC-UV and UHPLC-SRM quantifications. Three groups of polyphenols were observed, the first one with equivalent results between the two quantification methods (in most cases), and the two others with overestimated or underestimated results when comparing UHPLC-UV and UHPLC-SRM quantifications. [less ▲]

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See detailLitterfall quantity and quality and nutrient status in a young stand under Norway spruce and broadleaved species
Bazgir, Masoud; Carnol, Monique ULg

Poster (2012, July)

In Europe, because of previous intense forest use in the past centuries, the plantation of coniferous stands, especially Norway spruce with high production potential has been a common strategy. However ... [more ▼]

In Europe, because of previous intense forest use in the past centuries, the plantation of coniferous stands, especially Norway spruce with high production potential has been a common strategy. However, the characteristics of Norway spruce such a s susceptibility to windfall, forest dieback and soil acidification have caused negative ecological impacts at many sites. Conversion of conifers into deciduous or mixed stands has been suggested in order to improve ecological conditions and biodiversity o f forest ecosystems. In this study, six broadleaved species were planted at the same site, thus being subjected to similar condition in terms of soil type, land use history and climate. The aim of this research was to study of foliar nutrient status and nu trient return to the forest floor through litterfall 11 years after conversion of Norway spruce (Picea abie s (L.) KARST.) into a mixed stand with common alder (Alnus glutinosa (L.) GAERTN.), european beech (Fagus sylvatica L.), pedunculate oak (Quercus rob ur L.), silver birch (Betula pendula ROTH.), goat willow (Salix caprea L.) and rowan (Sorbus aucuparia L.). Our results revealed that tree species had a different foliar nutrient status and an effect on nutrient input fluxes through litterfall. For example , litter nutrient contents (N, Ca, Mg, K) were highest under alder, rowan and willow. Total litterfall and nutrient fluxes from leaf litter were highest under rowan. Our results demonstrate that, on poor sites, plantation of pioneer species, especially row an, may improve the nutrient status of the forest floor through higher input in litterfall. [less ▲]

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See detailDRIVING FACTORS OF SOIL FERTILITY IN MOUNTAIN TERRACED PADDY FIELDS OF YUANYANG (CHINA)
Colinet, Gilles ULg; Wu, Bozhi; Li, Yongmei et al

Poster (2012, July)

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See detailTransposability and evaluation of pedotranfer functions for predicting properties of water retention on soils of low chelif. Algeria
Touil, Sami; Saidi, Djamel; Degré, Aurore ULg

Poster (2012, July)

An important question remains about PTF’s transposability to others agropedoclimatic contexts. Models developed and validated in a particular bioclimatic context, were relatively little tested in other ... [more ▼]

An important question remains about PTF’s transposability to others agropedoclimatic contexts. Models developed and validated in a particular bioclimatic context, were relatively little tested in other contexts. The evaluation of PTF to estimate water retention at field capacity pF 2.5 (-330 hPa) and at wilting point pF 4.2 (-15000 hPa) of some soils of Lower Cheliff is presented. [less ▲]

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See detailNuclear genetic structure of Myodes glareolus in Fennoscandia with a particular emphasis on the contact zones - Preliminary results
Pisano, Julie ULg; Henttonen, Heikki; Galan, Maxime et al

Poster (2012, July)

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See detailNon-radial, non-adiabatic solar-like oscillations in RGB and HB stars
Grosjean, Mathieu ULg; Dupret, Marc-Antoine ULg; Belkacem, Kevin et al

Poster (2012, July)

Corot and Kepler observations of red giants reveal rich spectra of non-radial solar-like oscillations allowing to probe their internal structure. We compare the theoretical spectrum (amplitudes and life ... [more ▼]

Corot and Kepler observations of red giants reveal rich spectra of non-radial solar-like oscillations allowing to probe their internal structure. We compare the theoretical spectrum (amplitudes and life- times) of two red giants in the same region of the HR diagram but in different evolutionary phases. The lifetimes are obtained by computing theoretical non-adiabatic non-radial solar-like oscillations for mixed modes in the two models. Thanks to this, we have been able to compute the oscillation amplitudes through a stochastic excitation model. We present here our first results on the inertia, damping rates and amplitudes of the oscillations in the two stars and discuss the trapping, the visibilities and the am- plitudes of the different modes. The differences in the spectra of the two stars are also investigated. As already known, the period spacings in the two models are very different. Moreover, we find significant differences in amplitudes and lifetimes between the two models. [less ▲]

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See detailContribution of new radiocarbon dates to track the impact of past anthropogenic disturbances on current vegetation in Central Africa
Morin-Rivat, Julie ULg; Gillet, Jean-François ULg; Bourland, Nils ULg et al

Poster (2012, July)

Introduction: Understanding current Central Africa vegetation patterns faces the scarcity of data about their past evolution. However, a growing hypothesis suggests that past human activities could have ... [more ▼]

Introduction: Understanding current Central Africa vegetation patterns faces the scarcity of data about their past evolution. However, a growing hypothesis suggests that past human activities could have had a substantial influence on vegetation (Van Gemerden et al. 2003, Brncic et al. 2009). Indeed, by creating large openings (fig. 1), they might have triggered the expansion of light-demanding species currently suffering from a lack of regeneration. This lack of saplings could have been caused by the change in land use since colonization with the sedentarization of shifting cultivators. Aim of the study: To investigate the potential relationship between past anthropogenic disturbances and present vegetation. Material & methods: Fieldworks combining anthracological and ecological approaches have been undertaken in Northern Congo and South-Eastern Cameroon (fig. 2). We excavated thirty 150-200 cm deep pits under different forest covers and vegetation types to identify evidences of past human presence (i.e potsherds, fig. 3, slags from metallurgy, anthropogenic pieces of charcoals and anthropophilous charred seeds). Charcoals and seeds (oil palm Elaeis guineensis, fig. 4, Canarium schweinfurthii) in combination with artifacts have been dated. Results: A set of 38 new radiocarbon dates ranging from 15,200 cal BP to present time have been obtained. They confirm the existence of important past fire events in a region where natural ones seldom occur. Together with artifacts, our findings support the few already available dates documenting evidences of past human activities in Central African rainforests. On the 36 most recent dates (fig. 5), the majority belongs to the 2,300-1,400 cal BP period (61%). The whole semi-deciduous forest zone is concerned by this period of intense disturbances with a high rate of fragmentation. It follows the last great arid phase ca. 2,500 cal BP and might be linked to the iron workers expansion. Another pool of dates between 650 and 250 cal BP (33%) associated with potsherds might be correlated to a dry phase contemporary to the Little Ice Age in Europe. That last group of dates points out the potential positive impact of anthropogenic disturbances connected to a dry climatic event on light-demanding species populations. Indeed, this is consistent with the fact that most of current light-demanding trees have a higher number of stems around 100 cm dbh. Conclusion: Our multidisciplinary approach allowed new insights into the link between human history and vegetation dynamics in Central Africa. Further investigations should be conducted to go deeper into the understanding of the evolution of Central African rainforests and to improve the management of currently logged light-demanding species resulting from the LIA period. Thirty new dates from sixteen soil profiles are forthcoming. References: Brncic T., Willis M., K. J., Harris D. J., Telfer M. W. & Bailey M. W. 2009. Fire and climate change impacts on lowland forest composition in northern Congo during the last 2580 years from palaeoecological analyses of a seasonally flooded swamp. The Holocene, 19, 79-89. Reimer P. J., Baillie M. G. L., Bard E., Bayliss A., Beck J. W., Blackwell P. G., Bronk Ramsey C., Buck C. E., Burr G. S., Edwards R. L., Friedrich M., Grootes P. M., Guilderson T. P., Hajdas I., Heaton T. J., Hogg A. G., Hughen K. A., Kaiser K. F., Kromer B., McCormac F. G., Manning S. W., Reimer R. W., Richards D. A., Southon J.R., Talamo S., Turney C. S. M., van der Plicht J., & Weyhenmeyer, C. E. 2009. IntCal09 and Marine09 radiocarbon age calibration curves, 0-50,000 years cal BP. Radiocarbon, 51(4), 1111-1150. Van Gemerden B. S., Olff H., Parren M. P. E, Bongers F. 2003. The pristine rain forest? Remnants of historical human impacts on current tree species composition and diversity. Journal of Biogeography, 30, 1381-1390. [less ▲]

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See detailIncreased cell proliferation in Seriatopora hystrix following heat-induced bleaching
Fransolet, David ULg; Ugille, Aurélie; Leblud, Julien et al

Poster (2012, July)

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See detailWavelet Spectrum Estimation under Chronology Uncertainties Application to Dust Flux Data from Belgian Fagnes
Lenoir, Guillaume; Allan, Mohammed ULg; Crucifix, Michel et al

Poster (2012, July)

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See detailDevelopment of semiochemical slow-release formulations as biological control devices
Heuskin, Stéphanie ULg; Lorge, Stéphanie ULg; Leroy, Pascal ULg et al

Poster (2012, July)

Semiochemicals have been widely considered within various integrated pest management (IPM) strategies. In the present work, two sesquiterpenoids, E-β-farnesene and E-β-caryophyllene, were formulated for ... [more ▼]

Semiochemicals have been widely considered within various integrated pest management (IPM) strategies. In the present work, two sesquiterpenoids, E-β-farnesene and E-β-caryophyllene, were formulated for their related properties as aphid enemy attractants. E-β-farnesene, the alarm pheromone of many aphid species, was also identified as a kairomone of aphid predators (Episyrphus balteatus De Geer (Diptera: Syrphidae)) and parasitoids (Aphidius ervi Haliday (Hymenoptera: Braconidae)). E-β-caryophyllene was identified as a potential component of the aggregation pheromone of the Asian ladybird, Harmonia axyridis Pallas, another aphid predator. The two products were purified from essential oils of Matricaria chamomilla L. (Asteraceae) and Nepeta cataria L. (Lamiaceae) for E-β-farnesene and E-β-caryophyllene, respectively. Natural and biodegradable slow-release formulations were then investigated in order to deliver these molecules on crop fields for a long period of time as biological control devices. Due to their sensitivity to oxidation, both sesquiterpenes needed to be protected from degradation. For this purpose, alginate – hydrophilic matrix with low oxygen permeability – was used as polymer for the formulations: the main objective was to deliver semiochemical substances in the air in a controlled way. Consequently, a careful selection of alginates was realised. Formulated beads showed different structural and encapsulation properties depending on various formulation factors. Alginate formulations were characterized by texturometry and by confocal microscopy in order to observe the distribution of semiochemicals in alginate network. The last step of alginate bead characterisation consisted in studying release rate of semiochemicals in laboratory-controlled conditions by optimised trapping and validated Fast-GC procedures. Finally, the efficiency of formulations as aphid predator (Syrphidae) and parasitoid (A. ervi) attractants was demonstrated by field trapping and olfactometry experiments. [less ▲]

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See detailParticle acceleration in colliding-wind massive binaries: a relevant science case for ASTRO-H
De Becker, Michaël ULg; Khangulyan, Dmitry; Bosch-Ramon, Valenti

Poster (2012, July)

The strong stellar winds of massive stars in binary systems interact through shocks responsible for several phenomena, including significant particle acceleration up to relativistic energies. The ... [more ▼]

The strong stellar winds of massive stars in binary systems interact through shocks responsible for several phenomena, including significant particle acceleration up to relativistic energies. The existence of this relativistic particle population is mainly revealed through detection of bright synchrotron radio emission in the case of a few tens of systems. More recently, Suzaku observations revealed the existence of non-thermal X-rays in the case of two colliding-wind binaries (CWBs), confirming the prediction that inverse Compton scattering should be at work in these objects. In this context, the ASTRO-H mission constitutes the ideal tool to investigate non-thermal phenomena in hard X-rays (above 10 keV), where the well-known thermal emission from the shocked winds should not be significantly present. This poster gives an overview of this science case, and provides clues for the expected input of ASTRO-H in the study of these objects. [less ▲]

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See detailNon-thermal Hard X-ray Emission from Colliding Wind Binary Systems
Khangulyan, Dmitry; Bosch-Ramon, Valenti; De Becker, Michaël ULg

Poster (2012, July)

Colliding-wind massive star binaries are known to produce strong shocks in their wind-wind interaction regions. The interaction region is the scenario of several physical processes, including strong ... [more ▼]

Colliding-wind massive star binaries are known to produce strong shocks in their wind-wind interaction regions. The interaction region is the scenario of several physical processes, including strong thermal X-ray emission and in several cases particle acceleration up to relativistic energies. The latter process is still poorly understood in these environments, and deserves a particular attention in stellar astrophysics. The investigation of particle acceleration is a critical aspect of high-energy astrophysics, especially at energies above 10 keV where non-thermal emission processes dominate. We discuss the possibility to detect the hard X-ray emission from WR147, a well-known particle accelerator, using Astro-H Hard X-ray Telescope (HXT) and Soft Gamma-Ray Detector (SGD), and to probe the particle acceleration process at work in its colliding-wind region. [less ▲]

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See detailA 40-year accumulation dataset for Adelie Land, Antarctica and its application for model validation
Agosta, Cécile ULg; Favier, Vincent; Genthon, Christophe et al

Poster (2012, July)

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See detailDiversity of the cyanobacterial communities from the Sør Rondane Mountains (Eastern Antarctica)
Mano, Marie-José ULg; Namsaraev, Zorigto; Fernandez, Rafael et al

Poster (2012, July)

The new Belgian “Princess Elisabeth” research station was built in 2009 and is located 200 km inland in the Western part of the Sør Rondane Mountains (Eastern Antarctica). The BELSPO projects ANTAR-IMPACT ... [more ▼]

The new Belgian “Princess Elisabeth” research station was built in 2009 and is located 200 km inland in the Western part of the Sør Rondane Mountains (Eastern Antarctica). The BELSPO projects ANTAR-IMPACT and BELDIVA aimed to evaluate the diversity and the distribution patterns of the microorganisms from different types of habitats in a radius of 50 km around the Belgian station. These data will serve to follow future anthropogenic and climatic impacts on these communities. Here, we focus on the diversity of cyanobacteria. [less ▲]

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See detailMid and late Holocene dust deposition in Western Europe: The Misten peat bog (Hautes Fagnes - Belgium)
Allan, Mohammed ULg; Fagel, Nathalie ULg; Le Roux, Gael et al

Poster (2012, June 28)

The Misten peat bog representing 7.5 m of peat accumulation in the Hautes-Fagnes Plateau, Belgium, provides a record of Rare Earth Elements (REE) deposition since more than 7000 years. The analyses of REE ... [more ▼]

The Misten peat bog representing 7.5 m of peat accumulation in the Hautes-Fagnes Plateau, Belgium, provides a record of Rare Earth Elements (REE) deposition since more than 7000 years. The analyses of REE and lithogenic element concentrations, as well as the Nd isotopes, were performed by HR-ICP-MS and MC-ICP-MS, respectively in peat layers previously dated by 210Pb and 14C. REE concentration variations in peat samples are correlated with Ti, Zr and Sc that are lithogenic conservative elements, suggesting that REE are immobile in the studied peat bogs [1] and can be used as tracers of dust deposition. Peat humification, C/N ratio, ash content and bulk density were used to evaluate hydroclimatic conditions. The Nd values show large variability, between +1 to –22, identifying three major sources of dusts falling into the peat: local soils, distal volcanic and desert particles. More recently, industrial emissions provide a fourth source of dusts [2], which is also clearly recorded in the last 200 years of the Misten peat profile. [less ▲]

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See detailSynthesis of lutetium-carrying oligonucleotides for targeted cancer therapy and imaging
Gijs, Marlies ULg; Aerts, An; Impens, Nathalie et al

Poster (2012, June 27)

In this study, different techniques were evaluated to test the binding properties of an anti-HER3 aptamer to its target on cells or as pure protein. Furthermore, the aptamer was successfully coupled to ... [more ▼]

In this study, different techniques were evaluated to test the binding properties of an anti-HER3 aptamer to its target on cells or as pure protein. Furthermore, the aptamer was successfully coupled to DOTA-NHS ester and labelled with natural occurring lutetium. However, for a better yield, the coupling and labelling reactions need further optimization. [less ▲]

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See detailCoupling long term database with SWAT and STICS models for testing modles and simulating nitrogen management scenarios
Deneufbourg, Mathieu ULg; Pugeaux, Nicolas; Huguet, Jean et al

Poster (2012, June 26)

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See detailDoes fluid intelligence protect from age-related decline in cognitive control ?
Manard, Marine ULg; Carabin, Delphine; Collette, Fabienne ULg

Poster (2012, June 25)

Age-related difficulties have been reported on proactive control whereas reactive control seems to remain intact. This study investigated the potential influence of fluid intelligence capacity on the age ... [more ▼]

Age-related difficulties have been reported on proactive control whereas reactive control seems to remain intact. This study investigated the potential influence of fluid intelligence capacity on the age-related decline in proactive control. We used a working memory recognition paradigm involving proactive or reactive cognitive control by manipulating the interference level across items. 80 young adults (18-29 years old) and 80 healthy older adults (60-89 years old) were included. The main results revealed significant effects of age and fluid intelligence capacity on sensitivity to interference. As expected, reactive control performance remained intact with aging (similar interference effect in the two groups). In contrast, we observed a larger interference effect in the proactive condition in aging. Finally, older participants with similar level of fluid intelligence to young adults showed no proactive control age-related decrement. Beyond the fact that this study confirms the selective age-related decline in proactive control, it also indicates that the level of fluid intelligence influences the efficiency of proactive control in aging. [less ▲]

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See detailThe meeting preparation task: Validation of a new measure of everyday life functioning with persons diagnosed with schizophrenia.
Laloyaux, Julien ULg; Levaux, Marie-Noëlle ULg; Mourad, Haitham et al

Poster (2012, June 25)

Objective: The objective was to create a new measure of everyday life functioning by developing a computerized real-life activity task where participants are asked to prepare a room for a meeting ... [more ▼]

Objective: The objective was to create a new measure of everyday life functioning by developing a computerized real-life activity task where participants are asked to prepare a room for a meeting. Background: Difficulties in everyday life activities are core features of persons diagnosed with schizophrenia. However, everyday life functioning is usually evaluated with questionnaires, performance-based or observation assessments, all of which contain a number of limits. Method: Twenty-one individuals diagnosed with schizophrenia and 21 matched healthy controls completed the computerized meeting preparation task. Patients were also evaluated with an extensive cognitive battery and several measures of symptomatology and everyday life functioning. Results: Results showed that performance on the computerized task significantly differentiated patients and controls for a certain number of variables. These variables, summarized in a global score, were significantly correlated with both cognitive and everyday life functioning. Moreover, this composite score significantly predicted 39% of everyday life functioning, whereas a cognitive composite score only predicted 22%. In addition, when the meeting task composite score was combined with symptomatology and the cognitive composite score, these measures significantly predicted up to 73% of everyday life functioning. Conclusion: The findings suggest that the meeting preparation task provides a good indication of the level of everyday life functioning in patients with schizophrenia, and may be viewed as a valuable instrument in both an evaluation and remediation context. [less ▲]

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See detailCurrent Pericopsis elata (Fabaceae) patches in southeastern Cameroon: remnants of a long and rich Human-rainforest relationship?
Bourland, Nils ULg; Cerisier, François; Livingstone Smith, Alexandre et al

Poster (2012, June 23)

Pericopsis elata is one of the most valuable African timber species. This IUCN Red Listed tree suffers from a lack of regeneration, thus its current presence provokes questioning. Our work aimed at ... [more ▼]

Pericopsis elata is one of the most valuable African timber species. This IUCN Red Listed tree suffers from a lack of regeneration, thus its current presence provokes questioning. Our work aimed at understanding its origins so as to help securing its future. This study, lead away from engineering works, was conducted in four different sites located within the natural distribution area of the species and taking into account the different growing conditions were the species occurs. Our observations are based on an analysis of charcoal elements and pottery fragments discovered in subsurface layers of soils as well as current botanical and pedological surveys. Evidence of past human activities we found led to the assumption that this part of the Congo Basin was much more inhabited than previously thought. Some of the results obtained for P. elata could apply for other long lived light demanding species growing in the same environment [less ▲]

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See detailOncogenic human papillomavirus could directly interact with Natural Killer cells
Renoux, Virginie; Bastin, Renaud ULg; Boniver, Jacques ULg et al

Poster (2012, June 22)

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See detailRole of γδ T cells in HPV-induced cancer progression
Van hede, Dorien ULg; Bastin, Renaud; Francis, Floriane et al

Poster (2012, June 22)

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See detailMolecular imaging through in combinaison with quantitative proteomic approaches unraveling the molecular players of breast cancer adaptation to anti-angiogenic therapy.
Cimino, Jonathan ULg; Sounni, Nor Eddine ULg; Calligaris, David ULg et al

Poster (2012, June 22)

Breast carcinoma is the most common and second leading cause of cancer mortality in women. The recognition of the “angiogenic switch” as a rate-limiting secondary step in tumorigenesis led to extensive ... [more ▼]

Breast carcinoma is the most common and second leading cause of cancer mortality in women. The recognition of the “angiogenic switch” as a rate-limiting secondary step in tumorigenesis led to extensive pre-clinical researches on angiogenesis and finally the approval of VEGF-neutralizing antibodies (bevacizumab) and VEGF receptor tyrosine kinase inhibitors (RTKs:Sunitinib). The Sunitinib has been used clinically in patients with breast cancer refractory to other therapeutic agents. Unfortunately, like the cytotoxic therapies, these drugs do not produce lasting effects and resistance to treatment appeared clinically. Questions have emerged about the failure of anti-angiogenic therapy in clinic and the limitations of predictive preclinical models, and also about the molecular assessment of all stages of tumor adaptation and metastatic disease. To this end, we applied quantitative proteomics and imaging mass spectrometry tools to visualize and study the profiles of proteins and small molecules associated with tumor treated or not with Sunitinib using a novel preclinical model of breast carcinoma cells. In this project, we first developed a reproducible model of resistance to Sunitinib of human triple negative breast cancer MDA-MB-231 cells expressing luciferase gene. Cells were subcutaneously injected into mice RAG1-/- and divided into four experimental groups including, control mice treated with vehicle or Sunitinib for 30 days and sacrificed 1 days after treatment withdrawal or when tumor reached a volume of 300 mm3. In the second step. Tumors were analyzed using a nanoAcquity UPLC Synapt TM HDMS TM G1 (Waters, Manchester,UK) and Mass Spectrometry Imaging. For quantitative proteomic analyses of tumors, a bioinformatics analysis was used with the Protein lynx global server 2.2.5 software. Imaging mass spectrometry was performed on tissue sections of tumors and organs subsequently colonized by metastases. Matrix sublimation was used to coat tumor sections (14 µm-tick) with 1.5 Diaminonaphthalene for lipids analysis and Sinapinic acid for entire proteins analysis. Ion cartographies were recorded with a Solarix 9.4T FTMS instrument for lipids and with an Ultraflex II TOF-TOF instrument for entire proteins (Bruker Daltonics, Germany) with a spatial resolution of 100 µm. Global protemic revealed different protein profiles between tumor treated or not with Sunitinib. The Mass Spectrometry Imaging detected differences in intensity and location of some proteins and lipids are also associated with some histological features including inflammatory, necrotic and angiogenic areas. Bioinformatics analysis will be applied to ensure the integration of all data in order to provide the basis for identifying molecular pathways activated during the acquisition of refractoriness to drug treatments. [less ▲]

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See detailInteraction of HTLV-1 Tax with minichromosome maintenance proteins accelerates the replication timing program
Barez, Pierre-Yves ULg; Willems, Luc ULg

Poster (2012, June 22)

First human retrovirus discovered, HTLV-1 infects approximately twenty million individuals worldwide. HTLV-1 is the causative agent of different diseases among which the most important are the adult T ... [more ▼]

First human retrovirus discovered, HTLV-1 infects approximately twenty million individuals worldwide. HTLV-1 is the causative agent of different diseases among which the most important are the adult T-cell leukemia (ATL) and a neurodegenerative disorder called HAM/TSP (Human associated myelopathy/ Tropical spastic paraparesis). We are interested in the mechanisms of transformation by the viral Tax oncoprotein. Recently, we showed that Tax interacts with the minichromosome maintenance MCM2-7 helicase and binds to origins of DNA replication (Boxus et al, 2012 Blood 119:151). Thereby, Tax modulates the spatiotemporal program of origin activation during the S phase of cell cycle. In fact, Tax accelerates S phase progression by inducing early firing of late replication origins. Concomitantly, Tax-MCM2-7 interplay also modulates viral transcription. Together, our data demonstrates that interaction between Tax and MCM2-7 is involved in replication reprogramming and viral transcription. [less ▲]

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See detailCheckpoints modulation by the human T-lymphotropic virus type 1 (HTLV-1) Tax protein : towards new therapeutic approaches
Carpentier, Alexandre ULg; Willems, Luc

Poster (2012, June 22)

HTLV-1 infects approximately 20 million people worldwide and causes several diseases. This virus is responsible for the adult T-cell leukemia (ATL) and for a chronic neuropathology (TSP/HAM). There is ... [more ▼]

HTLV-1 infects approximately 20 million people worldwide and causes several diseases. This virus is responsible for the adult T-cell leukemia (ATL) and for a chronic neuropathology (TSP/HAM). There is currently no satisfactory treatment for these diseases. Among the proteins encoded by HTLV-1, Tax appears to play an important role in the mechanisms leading to pathogenicity. We are interested in the mechanisms of cell transformation by HTLV-1 and more particularly in the interplay between the viral Tax oncoprotein and the DNA damage response (DDR). We demonstrated that transient expression of Tax results in DNA damage, cell cycle arrest and activation of the ATM-Chk2-p53 axis of the DDR. In fibroblasts, cell cycle arrest occurs at the G1 and G2 phases depending on the p53 background. In contrast, HTLV-1 infected lymphocytes proliferate continuously and appear to be adapted to Chk2 and p53 checkpoints. This mechanism allows infected lymphocytes to proliferate despite the presence of genomic lesions. Our data shows that HTLV-1 infected cells use an alternative DNA repair pathway controlled by ATM and Chk1. This particularity may be used as novel therapeutic approach based on the principle of synthetic lethality. [less ▲]

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See detailSelection and cultivation of hydrolytic microorganisms extracted from the digestive tract of the termite Reticulitermes santonensis (3DV.1.55)
Tarayre, Cédric ULg; Bauwens, Julien ULg; Matteotti, Christel ULg et al

Poster (2012, June 21)

Biofuel production can be based on the use of fermentable substrates issued from the hydrolysis of lignocellulosic biomass stemming from agricultural residues and by-products. However, such substrates are ... [more ▼]

Biofuel production can be based on the use of fermentable substrates issued from the hydrolysis of lignocellulosic biomass stemming from agricultural residues and by-products. However, such substrates are not easy to degrade. Enzymes (cellulases, xylanases, etc.) can be used for this purpose and pre-treatments can increase their action by providing more available extremities. The digestive tract of the termite Reticulitermes santonensis contains various microorganisms (bacteria, molds, protists) able to degrade the wood components. These microorganisms act as consortia, leading to a better hydrolysis than in the cow rumen. Our purpose is the isolation of microorganisms from termite guts in order to evaluate their potential for hydrolysis of lignocellulosic materials. This approach led us to isolate and to study a bacteria (Bacillus sp.) displaying a xylanase activity, a mold (Aspergillus sp.) displaying a cellulase activity and a chrysophyte (protist) displaying an amylase activity. [less ▲]

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See detailPericopsis elata (Harms) Meeuwen in Cameroon: Ecological Check-up of an Endangered Timber Species
Bourland, Nils ULg; Kouadio, Yao Lambert; Lejeune, Philippe ULg et al

Poster (2012, June 20)

Pericopsis elata (Fabaceae – assamela, afrormosia, kokrodua) is a high valued timber species of the moist semi deciduous African forests. Because of logging which started more than 50 years ago, it is ... [more ▼]

Pericopsis elata (Fabaceae – assamela, afrormosia, kokrodua) is a high valued timber species of the moist semi deciduous African forests. Because of logging which started more than 50 years ago, it is considered as threatened and included on both IUCN Red List and CITES Appendix II. Nevertheless, there is still little information available on the species ecology: essential biological parameters controlling its population dynamics remain unknown. Our study first aims at improving the knowledge of its main ecological parameters, then at assessing the impact of selective logging on its populations in a forest management unit in Cameroon (ca 120,000 ha). After inventorying the species (sampling rate of 1.2%), mortality and growth were assessed over continuous 5 and 2-year periods in unlogged and logged areas, respectively. Phenology was monitored in the unlogged forest during 5 years (leaf shedding and flushing, flowering, ripe and unripe fruiting). The population structure followed a bell-shaped curve. Mean annual diameter increments in both environments did not differ significantly between unlogged and logged areas (0.29±0.06 0.31±0.04 cm for unlogged and logged areas, respectively). P. elata is a deciduous species that flowers at the end of the main dry season (Marsh-April). The minimum reproduction and effective flowering diameters were, respectively, 32 and 37 cm. Fruit maturation took place during 7 months (the seed rain occurs in December-January), but all unripe fruits abort 3 years out of 5. With a minimum logging diameter of 90 cm, the recovery rate computed over a 30-year period was greater than 100%. Selective logging harvested only 12.1% of the total number of seed trees and had little influence on the species biological parameters. Securing sufficient regeneration as a post-logging action is probably the most important consideration for achieving long-term sustainability. [less ▲]

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