References of "Scientific congresses and symposiums"
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See detailMatrimonial property and Succession under EU Private International Law : a Happy Marriage?
Wautelet, Patrick ULg

Conference (2014, March)

In this presentation, I attempt to examine the relationship between the Succession Regulation (650/2012) and matrimonial property. I do so by looking at the difficulties which could arise both from a ... [more ▼]

In this presentation, I attempt to examine the relationship between the Succession Regulation (650/2012) and matrimonial property. I do so by looking at the difficulties which could arise both from a practical perspective as well as from a more fundamental angle. Attention is given to the future Matrimonial Property Regulation and the need to coordinate it with the Succession Regulation. [less ▲]

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See detailInvestigating iron and organic matter incorporation in growing sea ice
Janssens, J.; Delille, Bruno ULg; de Jong et al

Conference (2014, March)

High concentration of exopolysacharides (EPS) and iron have been found in sea ice surrounding the Antarctic continent. However, the mechanisms leading to that enrichment remain unclear. Scavenging of iron ... [more ▼]

High concentration of exopolysacharides (EPS) and iron have been found in sea ice surrounding the Antarctic continent. However, the mechanisms leading to that enrichment remain unclear. Scavenging of iron by organic matter in seawater and entrainment during sea ice formation are thought to be responsible for the accumulation of iron in sea ice. EPS could also play a role in the iron passive chelative scavenging process in sea ice and in the increase of iron bioavailability. Our study investigates the processes responsible for the accumulation of iron (dissolved, particulate and total dissolvable iron), EPS, dissolved and particulate organic matter, macro-nutrients (silicic acid, nitrate and nitrite, phosphoric acid and ammonium), chlorophyll a and sea ice algae in young sea ice during an Australian-lead spring voyage off East Antarctica (SIPEX II September – November 2012) and a German-lead winter voyage to the Weddell Sea (AWECS June – August 2013). We used a combination of field- (“in situ”) and laboratory- based sea ice growth time-series experiments. In addition different types of newly formed sea ice as pancake ice, grey ice, frost flowers and slush were collected during both voyages as a means to compare and validate the experimental data. To our knowledge, this is the first report on the biogeochemical properties of newly formed Antarctic pack ice samples in the winter. Ice temperature, salinity and textures are also presented to support the biogeochemical observations at the onset of sea ice formation. [less ▲]

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See detailCertificat d’université en tutorat à distance : une approche de formation isomorphique pour acquérir des compétences de e-tuteur
Denis, Brigitte ULg

in Tutorales (2014, March), 12

Depuis plus d'une dizaine d'années, de nombreux auteurs ont décrit les rôles des tuteurs dans les dispositifs de formation en ligne (Depover et al, 2011 ; Salmon, 2000). La "présence" et les interventions ... [more ▼]

Depuis plus d'une dizaine d'années, de nombreux auteurs ont décrit les rôles des tuteurs dans les dispositifs de formation en ligne (Depover et al, 2011 ; Salmon, 2000). La "présence" et les interventions de ces derniers s'avèrent un facteur important dans l'efficacité de tels dispositifs, qu'il s'agisse de maintien de la motivation des apprenants ou du processus d'apprentissage. La variété des méthodologies mises en œuvre dans les scénarios de formation (apprentissage collaboratif, coopératif, individuel...) entraînent des modalités d'interaction différentes entre e-tuteur et apprenants. Se basant sur les étapes de formation au e-tutorat décrites par Denis (2003), un processus original de formation de e-tuteurs est proposé afin de rencontrer la diversité et l'adéquation des profils à adopter selon le contexte considéré. Le scénario de formation au e-tutorat recourt au principe d'isomorphisme en pédagogie (Leclercq, 1998). Outre des apports théoriques relatifs à la problématique traitée et une approche réflexive sur cette dernière, les formés sont amenés à vivre différentes situations d'animation qui pourront (ou non) les inspirer dans leurs futures pratiques de tutorat à distance. Par ailleurs, la formation met l'accent sur le respect d'une triple concordance entre les compétences visées, les activités mises en place et les modalités d'évaluation. [less ▲]

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See detailBiological and physical controls on DMS,P dynamics in ice-shelf-influenced fast ice
Carnat, G.; Zhou, Jiayun ULg; Papakyriakou, T. et al

Conference (2014, March)

Dimethylsulfide (DMS) is a volatile sulphur compound produced by the degradation of dimethylsulphoniopropionate (DMSP), a metabolite synthesized by microalgae as i.a. cryoprotectant and osmoregulator. It ... [more ▼]

Dimethylsulfide (DMS) is a volatile sulphur compound produced by the degradation of dimethylsulphoniopropionate (DMSP), a metabolite synthesized by microalgae as i.a. cryoprotectant and osmoregulator. It is also an important climate-active gas, being the primary source of marine-derived sulphate aerosols which play an important role in the earth-atmosphere radiation balance. In the last two decades, there has been an increasing interest in the role of the marine cryosphere in the DMS,P cycle, motivated by repeated observations of very high DMS,P concentrations in sea ice. However, our understanding of the factors driving the spatiotemporal variations of these high concentrations, and hence the fate of the sea ice DMS pool, remains limited. To date, studies have essentially focused on biotic factors, attributing the high DMS,P concentrations to the high biomass of the sympagic communities, and to their strong physiological response to the low temperature and high salinity stresses of the brine habitat. We present here an approach integrating both biotic and abiotic factors, as we investigate the influence of sea ice growth processes and brine dynamics on the DMS,P cycle. We focus on a fast ice site (Cape Evans, McMurdo Sound, Antarctica) under the influence of ice-shelf waters, and provide measurements covering a full cycle of ice growth. We show a good correspondence between isolated maxima of DMS,P in interior ice and the occurrence of platelet crystals in the ice texture. We develop the idea that platelet ice formation in May strongly modifies the production of DMS,P by (1) favoring the incorporation of strong DMSP producers and by (2) exposing these producers to stronger environmental stresses. We then show the influence of the development and decline of a strong diatom bloom from October to November on bottom ice DMS,P concentrations. Finally, we show that the increase in brine volume fraction (permeability) on warming in early December triggers (1) an important release of DMS to the ocean through brine convection, and (2) a vertical redistribution of DMSP across the ice. [less ▲]

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See detailLa Vierge protectrice des villes
Delfosse, Annick ULg

Conference (2014, February 28)

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See detailSCC-Optimiser la pertinence du parcours patient
WANG, François-Charles ULg

Conference (2014, February 28)

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See detailLe schizophrène : du paradoxe évolutionniste à la psychopathologie éthologique
Englebert, Jérôme ULg

Conference (2014, February 28)

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See detailRevisiting Snu spaces with wavelet leaders to detect non concave and non increasing spectra
Esser, Céline ULg

Poster (2014, February 27)

A multifractal formalism is a formula which is expected to yield the spectrum of singularities of a function from quantities which are numerically computable. The most widespread of these formulas is the ... [more ▼]

A multifractal formalism is a formula which is expected to yield the spectrum of singularities of a function from quantities which are numerically computable. The most widespread of these formulas is the so-called thermodynamic mul- tifractal formalism, based on the Frish-Parisi conjecture. It presents two drawbacks: it can hold only for spectra which are concave and it can only yield the increasing part of the spectrum. This first problem can be avoided using Sν spaces. The second one can be taken care using the wavelet leaders method. In this poster, we present a new multifractal formalism based on a generaliza- tion of the Sν spaces using wavelet leaders. It allows to detect non concave and non increasing spectra. We compare this formalism with the Sν method and the wavelet leaders method. It is based on joint works with F. Bastin, S. Jaffard, T. Kleyntssens and S. Nicolay. [less ▲]

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See detailThe end of roaming in the forest causes a loss of timber resources: the paradox of slash-and-burn agriculture
Morin-Rivat, Julie ULg; Fayolle, Adeline ULg; Favier, Charly et al

Conference (2014, February 27)

Tropical forests are not believed as pristine anymore. Their structure and specific composition are induced by past climatic and human disturbances over years. In the African moist forests, the emergent ... [more ▼]

Tropical forests are not believed as pristine anymore. Their structure and specific composition are induced by past climatic and human disturbances over years. In the African moist forests, the emergent trees are mainly light-demanding. These trees are considered to derive from the recent disturbances of the last centuries. Most of them are exploited for their timber. However, several of these tree species are currently suffering from a lack of regeneration that threatens the specific diversity of the forests and the sustainability of timber exploitation. Through dendrometric and radiocarbon analyses we found that the majority of the trees of the Congo Basin are not older than 160 years. This corresponds to about the year 1850 when the Europeans colonized the inner regions of Central Africa. By reassembling people along the road axes, the colonial administration reduced the forest roaming. Former activities such as slash and burn agriculture created large openings in the canopy that allowed light-demanding tree species to establish. Currently we observed that timber logging does not provide openings large enough for the recruitment of these species. We thus anticipate that adjustments in forest management strategies shall be made to preserve the forest resources, for instance by recreating the conditions of slash and burn agriculture. [less ▲]

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See detailLa jurisprudence européenne de 2013 en matière de fiscalité directe et ses conséquences en Belgique. Morceaux choisix
Richelle, Isabelle ULg; Traversa, Edoardo

Conference (2014, February 27)

Actualité relative aux conventions préventives de la double imposition et à la jurisprudence de la Cour de justice; le point sur les récentes initiatives de l’OCDE et de la Commission européenne en ... [more ▼]

Actualité relative aux conventions préventives de la double imposition et à la jurisprudence de la Cour de justice; le point sur les récentes initiatives de l’OCDE et de la Commission européenne en matière de lutte contre la planification fiscale agressive et contre l’érosion de l’assiette fiscale. [less ▲]

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See detail6. Lutte intégrée contre les maladies
Duvivier, Maxime; Bataille, Charlotte; Mahieu, Olivier et al

in Bodson, Bernard; Destain, Jean-Pierre (Eds.) Livre blanc céréales (2014, February 26)

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See detail3. Lutte contre les mauvaises herbes
Henriet, François; Jaunard, Delphine; Gilleman, Alice ULg et al

in Bodson, Bernard; Destain, Jean-Pierre (Eds.) Livre Blanc céréales (2014, February 26)

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See detailEffects of Eisenia fetida on metal uptake of heavy metals from polluted soils by Vicia faba and Zea Mays
Lemtiri, Aboulkacem ULg; Liénard, Amandine ULg; Francis, Frédéric ULg et al

Poster (2014, February 26)

Earthworms are known to increase availability of heavy metals in soils and also play an important role in maintaining the structure and quality of soil. The introduction of earthworms into soils ... [more ▼]

Earthworms are known to increase availability of heavy metals in soils and also play an important role in maintaining the structure and quality of soil. The introduction of earthworms into soils contaminated with metals has been suggested as an aid for phytoremediation processes. In Belgium (Wallonia), a century of industrial metallurgic activities produced significant heavy metal soil pollution. A large q u a n t i t y o f s m e l t e r w a s t e c r e a t e d a g r a d i e n t o f zi n c, lead and cadmium c o n c e n t r a t i o n . The objectives of our study were to evaluate : (i) the potential toxicity of heavy metal elements on the epigeic earthworms Eisenia fetida and on two plants Zea mays and Vicia faba and (ii) to determine the effects of the earthworms on the growth and contaminants phytoextraction process. The combination of behavioural factor measurements (survival, growth, reproduction of earthworms), physico-chemical parameters such as metal absorption, bioaccumulation by earthworms, soil physico-chemical changes, and plant responses (root and shoot elongation, dried biomass,…) provided a valuable indication of pollutant bioavailability and ecotoxicity. After 56-days exposure, the results suggest that adult earthworms have a strong tolerance for heavy metals exposure, but the responses depend on metal elements. Earthworms modify the bioavailable heavy metals in root and shoot in the contaminated soils and their activities alter shoot and root biomass of V. faba and Z. mays. The presence of earthworms led to a change in physico-chemical caracteristics in contaminated soils. These results show that the ecological context for phytoremediation should be broadened by considering earthwom – plant – soil interactions as they influence both plant health and absorption of heavy metals. [less ▲]

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See detail5. Régulateurs de croissande
Meza Morales, Walter ULg; Monfort, Bruno; Mahieu, Olivier et al

in Bodson, Bernard; Destain, Jean-Pierre (Eds.) Livre Blanc Céréales (2014, February 26)

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See detail4. La fumure azotée
Meza Morales, Walter ULg; Monfort, Bruno; Dumont, Benjamin ULg et al

in Bodson, Bernard; Destain, Jean-Pierre (Eds.) Livre Blanc céréales (2014, February 26)

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See detail2. Implantation des cultures
Eylenbosch, Damien ULg; Hiel, Marie-Pierre ULg; Meza Morales, Walter ULg et al

in Bodson, Bernard; Destain, Jean-Pierre (Eds.) Livre Blanc Céréales (2014, February 26)

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See detailPlants & metals in soil : the concept of phytoremediation
Evlard, Aricia ULg; Colinet, Gilles ULg; Druart, Philippe

Conference (2014, February 26)

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See detailOn the use of Belgian Soil Map to predict risk of nitrate and pesticide lixiviation
Bah, Boubacar Billo ULg; Vandenberghe, Christophe ULg; Deneufbourg, Mathieu ULg et al

Poster (2014, February 26)

Pollution by nitrate and pesticides has impacts on drinking water reserves and aquatic systems. Nowadays, this problem is the key point of the European Policy with the implementation of the Water ... [more ▼]

Pollution by nitrate and pesticides has impacts on drinking water reserves and aquatic systems. Nowadays, this problem is the key point of the European Policy with the implementation of the Water Framework Directive (Directive 2000/60/EC). According to these legislations, Member States are supposed to take measures to limit environmental and toxicological effects caused by nitrate and pesticides use. This paper presents three different approaches allowing assessment of diffuse (non-point sources) pollution risks of water resources by nitrate and pesticides. The first approach consists on the interpretation of the geomorphopedological information (geologic substratum type, presence of karst phenomena, soil texture, natural drainage, profile development, type and percent of stoniness, soil thickness, …) provided by the Digital Soil Map of Wallonia. Soil physical characteristics are assessed in terms of soil water percolation/infiltration, runoff, pollutants retention, mineralization, and erosion. Second approach consists on the use of spatially distributed mechanistic models. Nitrate lixiviation from agricultural land to groundwater has been simulated from the SWAT model. Pesticide lixiviation from soil to groundwater has been predicted from the one-dimensional, dynamic, multi-layered model named PEARL (Pesticide Emission Assessment at Regional and Local scales). Model input parameters are mainly extracted from the existing soil physical and physico-chemical, crop and pesticides properties databases. Relevant soil parameters not directly available in existing databases, such as bulk density, hydraulic conductivity, potential evapotranspiration… have been derived from pedotransfers functions. Third approach consists on in situ lixiviation studies by the way of lysimeters. Concentrations measured at the bottom (2 m deep) of lysimeters represent a straight “index of risk” for groundwater and, on the other hand, allow the validation of simulation models used to predict nitrate and pesticides lixiviation risk under different scenarios. The Digital Soil Map of Wallonia, one of the core data source, allows the spatialisation of the predicted lixiviation risk at regional level, providing to the local authorities and the decision makers a tool for the identification of the areas at risk of pollution, where specific monitoring actions and prevention measures for the protection of waters can be implemented. [less ▲]

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See detail10. Perspectives - 2. Perspectives offertes par la culture en association de froment et de pois protéagineux d'hiver
Pierreux, Jérome ULg; Delaplace, Pierre ULg; Roisin, Christian et al

in Bodson, Bernard; Destain, Jean-Pierre (Eds.) Livre Blanc céréales (2014, February 26)

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See detail9. Nutrition azotée de l'épeautre en Ardenne et en région limoneuse
Escarnot, Emmanuelle ULg; Meza Morales, Walter ULg; De Toffoli, Marc et al

in Bodson, Bernard; Destain, Jean-Pierre (Eds.) Livre blanc céréales (2014, February 26)

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See detailThe Usability of Green Building Rating Systems in Hot Arid Climates
Attia, Shady ULg

in ASHRAE (2014, February 24)

To develop adaptable and context sensitive building rating systems, the present work aimed to evaluate four rating systems that emerged recently in the Middle East. Literature review and cross comparison ... [more ▼]

To develop adaptable and context sensitive building rating systems, the present work aimed to evaluate four rating systems that emerged recently in the Middle East. Literature review and cross comparison analysis showed that the four examined rating systems namely, Green Pyramid Rating System (Egypt), Green Building Standard SI 5281 (Israel), Qatar Sustainability Assessment System (QSAS) and Pearl Building Rating System (UAE) are not enough adopted to local environmental, cultural, historical, societal and economic context. They showed also a comparable similarity since they all imitate the American LEED and British BREEAM rating systems. The paper elaborates on the comparison results and presents recommendations to improve the questioned rating systems and remind designers with the principles and strategies of sustainable design that goes beyond the existing rating systems in hot climate. The evaluation of the four systems might provide a new approach for regional harmonization among the four systems and the development of adaptable and context sensitive rating system. [less ▲]

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See detailDetection of eye movements specific to drowsiness and their relation with subjective assessment of sleepiness in PVT: A cognitive ergonomic approach
Blavier, Adelaïde ULg; Montagnino, Cédric; Wertz, Jérôme ULg et al

Conference (2014, February 24)

Drowsiness is one of the major factors explaining accidents, particularly in traffic accidents but also in work situations with serious consequences (e.g. medicine). The drowsiness may be assessed by ... [more ▼]

Drowsiness is one of the major factors explaining accidents, particularly in traffic accidents but also in work situations with serious consequences (e.g. medicine). The drowsiness may be assessed by diverse measures that vary from physiological and unconscious data (e.g. EEG) to subjective and conscious evaluation. In their daily life, people are used to evaluate their drowsiness by subjective assessment and research observes a great inter-individual variation in this evaluation. Moreover, the subjective evaluation is dependent on the situation and the risk perceived by the person (e.g., new versus usual situations, simple versus complex environments, etc.). In this theoretical context, our purpose was to investigate the links between 1) objective performance (reaction time) measured by a psychomotor vigilance task (PVT), 2) data from eye movements and 3) subjective assessment of drowsiness (measured with Karolinska Sleepiness Scale, KSS). 12 persons, aged from 20 to 56, participated individually. They were asked to respect a 60% sleep deprivation during the night before the experiment and to not drink any energy drinks the day of the experiment. The experiment was conducted between 1 and 3 PM after a heavy lunch in order to increase the circadian effect. Moreover, the temperature of the room was 25° in order to increase drowsiness. Each participant was asked to perform 4 PVT. However, although 100% of participants performed the first two PVT, only 66% were able to perform the third PVT and only 33% of participants performed the fourth and last PVT. Our results showed an effect of time on objective performance, eye movements and subjective assessment of drowsiness in PVT 1 and 2: significant increase of reaction time, increase of eye closure and perclos, reduction of pupil diameter and increase of subjective drowsiness estimation (KSS). Only the frequency and duration of blinks remained constant across time. In PVT 3 and 4, data from eye movements and objective performance (reaction time) did not vary anymore across the time. Only the subjective estimation of drowsiness (KSS) continued to increase. Furthermore, subjective estimation of drowsiness was differently correlated with eye movements and objective performance across the PVT; it was significantly correlated with reaction time (PVT 1,2,3), blink frequency and duration (PVT 1,2,3), perclos (PVT 1,2,3,4), eye closure (PVT 2,3), pupil diameter (PVT 1,2,3,4). These results are discussed and integrated in an ergonomic approach in order to analyze the links between objective performance, eye movements and subjective assessment of drowsiness. [less ▲]

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See detailStrategic Decision Making For Zero Energy Buildings in Jordan
Attia, Shady ULg; Zawaydeh, Samer

in Proceedings of the 1st International Conference on Energy & Indoor Environment for Hot Climates (2014, February 24)

This paper presents the results of combined economic and computational study of different integrated passive and active design strategies for the Jordanian residential building sector. A representative ... [more ▼]

This paper presents the results of combined economic and computational study of different integrated passive and active design strategies for the Jordanian residential building sector. A representative house prototype, located in Amman is selected as a case study for the zero energy design and performance objective. The aim of the study is to investigate the potential of achieving thermal comfort and delivering thermal and electrical energy demands for existing buildings on site for different Jordanian Cities. Jordan has a semi-arid climate with an annual total irradiation above 2000 bankable kWh/m2 per year with approximately 2000 hours of full sunshine. Therefore, different passive and active design strategies are discussed and compared to reach an annual net zero energy demand for the existing building stock. In order to achieve zero energy buildings certain strategies are examined. For example, internal loads reduction, envelope insulation in addition to the installation of solar water heater and photovoltaic. Based on a month-by–month demand analysis, internal loads and envelope performance are analyzed in order to explore the existing economical potential. Simulation software DesignBuilder is used to examine the strategies proposed to achieve annual net zero energy performance for a prototype. The final result of this study compares the potential and constraints of each strategy and assesses them based on economical feasibility. For the considered location and weather conditions the prototype can provide thermal comfort for occupants and meets the zero energy objectives. The research also proofs that some strategies are cost effective rewarding with a payback period ranging from 3 to 9 years. [less ▲]

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See detailAssessing the Thermal Performance of Bedouin Tents in Hot Climates
Attia, Shady ULg

in Proceedings of the 1st International Conference on Energy & Indoor Environment for Hot Climates (2014, February 24)

The aims of this study it to improve conditions inside Bedouin tents shelters and to develop tools to assess shelter quality and comfort. A prototype tent was tested in hot conditions with an internal ... [more ▼]

The aims of this study it to improve conditions inside Bedouin tents shelters and to develop tools to assess shelter quality and comfort. A prototype tent was tested in hot conditions with an internal vapor load. Temperature, humidity measurements and air speed were taken inside the shelter while the external temperature was maintained at 40°C (104°F). Building performance simulation was conducted to produce a simulation model. A model of a tent was constructed using the EnergyPlus simulation software and were calibrated with the test data. The shelter models were simulated in Wadi Rum, Jordan using real data from. The feasibility of heating the tent using only the casual gains from occupants and solar radiation was investigated, although it was found that a tent heated in this way would only be appropriate in spring and autumn. Design issues included coping with stratification of air temperature inside the tent, improving thermal comfort without compromising fabricating the materials cheaply and simply. The validity of the results is limited by the lack of measured data for rates of air infiltration. [less ▲]

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See detailGradient Boosted Regression Trees in Scikit-Learn
Prettenhofer, Peter; Louppe, Gilles ULg

Conference (2014, February 23)

This talk describes Gradient Boosted Regression Trees (GBRT), a powerful statistical learning technique with applications in a variety of areas, ranging from web page ranking to environmental niche ... [more ▼]

This talk describes Gradient Boosted Regression Trees (GBRT), a powerful statistical learning technique with applications in a variety of areas, ranging from web page ranking to environmental niche modeling. GBRT is a key ingredient of many winning solutions in data-mining competitions such as the Netflix Prize, the GE Flight Quest, or the Heritage Health Price. We give a brief introduction to the GBRT model and regression trees -- focusing on intuition rather than mathematical formulas. The majority of the talk is dedicated to an in depth discussion how to apply GBRT in practice using scikit-learn. We cover important topics such as regularization, model tuning and model interpretation that should significantly improve your score on Kaggle. [less ▲]

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See detailTraitement antihypertenseur : quelles sont les meilleures associations?
Krzesinski, Jean-Marie ULg

Conference (2014, February 22)

Stratégie du traitement de l’HTA en 2014: toujours basée sur le calcul du risque CV. L’HTA, tueur silencieux, est généralement associée à de nombreux autres facteurs de risque CV. Il faut préciser le ... [more ▼]

Stratégie du traitement de l’HTA en 2014: toujours basée sur le calcul du risque CV. L’HTA, tueur silencieux, est généralement associée à de nombreux autres facteurs de risque CV. Il faut préciser le niveau de risque CV en tenant compte de la valeur de PA et des autres F.R. pour décider le moment et le type de traitement ! [less ▲]

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See detail1er Colloque Guy Namurois : Livre des résumés
Jidovtseff, Boris ULg; Halleux, Philippe; Lambert, Eric et al

in Jidovtseff, Boris (Ed.) 1er Colloque Guy Namurois : Livre des résumés (2014, February 22)

Colloque multi-disciplinaire en l'honneur de Guy Namurois

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See detailZur Kontinuitätsproblematik in der ostbelgischen Nachkriegszeit
Brüll, Christoph ULg

Conference (2014, February 22)

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See detailPathologies des bétons: causes et effets
Courard, Luc ULg

in Evaluation des structures en béton (2014, February 20)

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See detailDynamics of the aurora at Jupiter
Bonfond, Bertrand ULg; Grodent, Denis ULg; Badman, Sarah et al

Conference (2014, February 19)

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Peer Reviewed
See detailLes herbivortes, transformateurs de produits fourragers et de coproduits issus de l'agro-industrie en aliments nobles pour l'homme
Decruyenaere, Virginie; Lessire, Françoise ULg; Beckers, Yves ULg et al

in CRA-W (Ed.) La viande bovine remise en question: De sa production à sa consommation (2014, February 19)

Les prairies recouvrent près de 50% de la surface agricole utile en Wallonie. Dans certaines régions, la prépondérance des prairies dans le paysage wallon se justifie par des contraintes climatiques. Pour ... [more ▼]

Les prairies recouvrent près de 50% de la surface agricole utile en Wallonie. Dans certaines régions, la prépondérance des prairies dans le paysage wallon se justifie par des contraintes climatiques. Pour celles-ci bien souvent, les sommes de température et la durée de végétation active sont faibles et limitent considérablement le choix des cultures susceptibles d’atteindre la maturité avant récolte avec certitude. Dans d’autres régions, les prairies s’imposent davantage en raison de contraintes agronomiques : nature du sol, disposition des parcelles, relief du territoire, intérêt dans la rotation pour les prairies temporaires… Ainsi, la grande majorité des prairies de notre Région ne peut pas être remplacée par des cultures ; elles doivent dès lors être perçues comme une bonne alternative à la valorisation du territoire. Grâce à la présence du rumen en amont de l’estomac, les ruminants ont la capacité de transformer des productions non éligibles pour l’homme, tels que les fourrages et les co-produits des industries agro-alimentaires. Ces aliments, de nature essentiellement fibreuse mais pas pour autant pauvres en protéine et en énergie, sont largement fermentés par les micro-organismes du rumen qui les dégradent en composés plus simples, valorisables ensuite par l’animal. Par ce mécanisme, les ruminants contribuent à transformer ces aliments grossiers en produits nobles, tels que le lait et la viande. On comprend dès lors aisément que la présence des ruminants est étroitement liée aux superficies enherbées, elles-mêmes dépendantes des conditions pédo-climatiques d’une région. Malgré des systèmes de production intensifs et l’amélioration continue du potentiel génétique des animaux, les bovins restent peu dépendants des aliments du commerce comparativement aux autres spéculations animales. Ainsi, selon l’APFACA, de l’ordre de 16% des aliments composés produits en Belgique et importés sont utilisés pour les bovins, dont seulement 1/3 est écoulé dans la filière viande bovine. L’herbe, les produits herbagers et les aliments produits sur l’exploitation tels que le maïs restent donc majoritaires dans la ration des bovins élevés pour la production de viande. La valorisation de l’herbe et des produits herbagers dépend fortement des performances zootechniques recherchées. Les objectifs de croissance sont établis, en autre, sur base des prix offerts par la cheville variant avec les catégories d’âge et de poids d’abattage. Ces dernières années, il semble que les animaux abattus un peu plus tardivement soient moins dépréciés qu’auparavant, facilitant la formulation de rations à base de matières premières herbagères. A l’inverse, l’intensification dans le but de produire des animaux abattus plus jeunes ou à un poids supérieur, implique une croissance plus soutenue, et de ce fait la distribution de rations plus denses en énergie. Pour la formulation de telles rations, certains coproduits disposent de valeurs nutritionnelles intéressantes, permettant de satisfaire des besoins nutritionnels élevés, tout en conservant une certaine autonomie alimentaire. Leur valorisation au niveau local représente en outre un intérêt considérable pour la rentabilité des industries agro-alimentaires qui, sans la présence de l’animal, devraient trouver d’autres débouchés pour les coproduits sous peine d’être dans l’obligation de financer leur élimination. Cet exposé a pour objectif d’illustrer les potentiels, mais aussi les limites, des aliments produits localement pour les bovins viande, que ce soit selon leur type (vache de réforme- taurillon…), leur race et leurs performances zootechniques, mais aussi l’intérêt de ces aliments en termes d’efficiences alimentaire et économique. Il analyse les atouts et faiblesses de la spéculation viande bovine en ne se limitant pas à l’échelle de l’animal seul, mais en le replaçant en tant que véritable maillon de la chaîne agro-alimentaire. Ce positionnement permet non seulement de mieux cerner les enjeux de ces élevages au niveau de la production primaire, mais aussi leur importance dans les secteurs amont et aval. [less ▲]

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See detailRecent advances and improvements in computerized adaptive testing with the R package catR
Magis, David ULg; Barrada, Juan

Conference (2014, February 14)

The purpose of this talk is to present recent advances and developments of the R package catR. This package allows for random generation of response patterns under computerized adaptive testing (CAT) and ... [more ▼]

The purpose of this talk is to present recent advances and developments of the R package catR. This package allows for random generation of response patterns under computerized adaptive testing (CAT) and holds various options to select the first items, estimate ability, select the next item, stop the test and return final results. Two main improvements were realized. First, several rules for next item selection were added, among others, Kullback- Leibler, progressive and proportional methods. Second, catR was limited to dichotomous IRT models so far. The most recent update allows now for several polytomous IRT models, such as partial and generalized partial credit model, graded and modified graded response models, rating scale model, and nominal response model. All improvements will be shortly presented, both from a theoretical point of view and in terms of practical implementation in catR. If possible, several illustrative examples will be displayed in a short live demonstration of catR. [less ▲]

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See detailDevelopment of educational info capsules proposing instructional strategies aiming to deal with overweight and obese students
Cloes, Marc ULg; LEBRETHON, Marie-Christine ULg; Feron, Isaline

Conference (2014, February 13)

Irwin et al. (2003) pointed out the principles that quality PE teachers should incorporate into their pedagogical practice in order to take into account the increasing number of overweight and obese ... [more ▼]

Irwin et al. (2003) pointed out the principles that quality PE teachers should incorporate into their pedagogical practice in order to take into account the increasing number of overweight and obese students in their classes. Fighting against obesity is so complex that no simple solution can be proposed. It means that the development of specific tools providing PE teachers with new instructional strategies inspired from public health is needed (Prusak et al., 2011). Inclusion of overweight students into PE can be linked with a social ecological model (Li & Rukavina, 2012). Even if PE teachers are able to develop and implement specific instructional strategies, it seems that they need support from health experts (Cloes et al., 2013). Internet, continuing professional development activities, and educational info capsules were identified as the preferred supports to be used by the practitioners (Cloes et al., 2014). The aims of this study were to produce and validate three pedagogical capsules focusing on specific concerns of PE teachers as well as to analyze the procedure of validation. Using an extensive analysis of the literature, the researchers first identified theoretical and practical resources to be mobilized in the understanding and development of solutions for the selected problems: (1) Students’ lack of awareness about the risks of overweight and obesity; (2) Constraints associated with the motor/physical disabling; (3) Parents’ lack of awareness about PA impact on health. The capsules were then submitted to 11 experts (health specialists, health educators, psychologists, PE teachers) who had to analyze the documents. They acknowledged the content and form of the capsules. Minor changes were requested in order to finalize them. The proposed evaluation sheet was also validated but face-to-face assessment was recommended. Dissemination of the existing capsules as well as development of additional ones should be the next steps of this project. [less ▲]

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See detailL'architecture Art nouveau à Liège (1895-1914)
Charlier, Sébastien ULg

Conference (2014, February 13)

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See detailImportance des récentes variations pluviométriques à Djibouti et besoins de quantification de leurs impacts
Mahamoud, Ayan; Nour Ayeh, Moustapha; Saad, Osman et al

Poster (2014, February 12)

Ces dernières décennies, l’Afrique de l’Est souffre d’une longue et lente détérioration pluviométrique. De 2007 à 2011, la ville de Djibouti a enregistré un déficit de 73% des précipitations moyennes ... [more ▼]

Ces dernières décennies, l’Afrique de l’Est souffre d’une longue et lente détérioration pluviométrique. De 2007 à 2011, la ville de Djibouti a enregistré un déficit de 73% des précipitations moyennes annuelles par rapport à la moyenne de 30 ans (1981-2010). Pour caractériser la sécheresse actuelle, nous analysons une série pluviométrique reconstruite pour Djibouti-Ville de 1901 à 2013, les données de terrain permettant d’illustrer les impacts de ces variations pluviométriques. Les précipitations enregistrées à Djibouti ne présentent aucune tendance sur le long terme (1901-2013). Par contre, ces dernières années montrent une très grande variabilité: le suivi de la moyenne pluviométrique sur 10 ans est à son maximum en 1998 (215 mm) et à son minimum en 2013 (79 mm). Depuis 2007, la pluie totale annuelle ne dépasse plus les 100 mm. C’est cette succession d’années déficitaires qui est problématique. Cette sécheresse sans précédent va mettre de nombreuses familles des zones rurales (de Djibouti, d’Ethiopie et de Somalie) sur la route. Cette migration a pour point de chute la ville de Djibouti où des quartiers neufs se créent, comme Buldhuqo. Totalement inexistant en 2004, il explose après 2009. Les derniers arrivants s’installent dans le fond de l’oued, là même où la zone était inondée en 2004 et 2009 suite à des pluies courtes mais intenses. La prochaine pluie extrême, l’exposition de ces populations précaires aux risques hydrologiques sera maximale. [less ▲]

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See detailNew mass spectrometry based methodology to sequence a whole snake venom
Echterbille, Julien ULg; Boulanger, Madeleine; Degueldre, Michel ULg et al

Poster (2014, February 10)

Animal venoms are complex chemical cocktails, comprising wide ranges of biologically active reticulated peptides that target with high selectivity and efficacy varieties of membrane receptors. Assuming ... [more ▼]

Animal venoms are complex chemical cocktails, comprising wide ranges of biologically active reticulated peptides that target with high selectivity and efficacy varieties of membrane receptors. Assuming the fact that each of the 170,000 venomous species reported can produce more than 250 bioactive toxins, at least 40,000,000 bioactive peptides and proteins may be discovered. Among the four described species of mambas, Eastern Jameson’s mamba (Dendroaspis jamesonii kaimosae) venom is the less characterized since only 9 peptides are referenced in database. This work aims at developing a new strategy devoted to the deep analysis of animal venoms. Our approach consists in a first separation of the venom using cation exchange chromatography. Each primary fraction is then purified a second time by classical RP-HPLC. A total of 328 fractions, containing amongst 1 and 4 toxins, are finally collected. MALDI-MS analysis of each fraction is done in order (1) to obtain information about masses and (2) to obtain sequences of toxins thanks to MALDI-In Source Decay (ISD) dissociation coupled with on MALDI target plate reduction of the peptides. ISD has already been demonstrated efficient for toxin sequencing, and especially when using 1,5-DAN as reducing matrix. ISD yields to sequences that cover more than 50% of peptide sequences by series of singly charged c-type ions. Thanks to this methodology, we were able to obtain 85% of satisfactory results i.e. spectra giving quite long tags of amino acids (up to 20 residues). As a way to validate our method, a tag coming from ISD spectrum interpretation has found a match in database for an Eastern Jameson’s mamba toxin. The global sequence has then been obtained by extrapolation on the ISD spectrum. Since ISD spectra are simpler than classical MS/MS spectra, automation of spectra interpretation, difficult with other fragmentation techniques (CID, ETD…), is implementable. In the near future, sequences obtained with this approach will be used to direct tests of biological activity through sequence homologies with already known ligands for different kinds of membrane receptors. [less ▲]

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See detailMolecular dynamic simulation of the cyclic lipodepsipeptide Pseudodesmin A self-assembly
Crowet, Jean-Marc ULg; Sinnaeve, Davy; Fehér, Krisztina et al

Conference (2014, February 10)

Pseudodesmine A is a cyclic lipodepsipeptide of nine residues which presents a moderate antibacterial activity and whose structure has been resolved by X-ray and NMR1,2. In acetonitrile, Pseudodesmine A ... [more ▼]

Pseudodesmine A is a cyclic lipodepsipeptide of nine residues which presents a moderate antibacterial activity and whose structure has been resolved by X-ray and NMR1,2. In acetonitrile, Pseudodesmine A is monomeric while in chloroform it has the same structure but assemble in a supramolecular complex. This structure could associate with membranes and be responsible of the biological activity of this peptide. Comparison of the NMR data between the two solvents has given indications on the intermolecular contacts that arise in chloroform and a model for the self association was proposed2,3. To study in more details this assembly, molecular dynamics have been carried on. In acetonitrile, the peptide show transient interactions while in chlorofom interactions between monomers was always observed. As stated in Sinnaeve et al. in 2009, these interactions arise mainly between the backbone protons of the LEU1 and the GLN2, the GLN2 sidechain and the loop located on the opposite end of the monomer structure. From 10 simulations of dimerization, hydrogen bonds were followed and specific interaction patterns were identified regarding the hydrogen bonds formed. The peptide interactions are mainly described by 13 interaction patterns; 8 with the peptides in a linear configuration, 1 perpendicular and 4 with peptides side by side. The patterns are characterized by 2 to 4 hydrogen bonds. From the linear dimer, it is possible to reconstruct filaments and, by combining a linear and a lateral dimer, it is possible to build fibrils with multi filaments, as expected in the NMR derived model. Besides, the perpendicular dimer can gives peptide rings that can also explain the potential ability of this peptide to form ion pores in membranes. 1. Sinnaeve, D., Michaux, C., Van hemel, J., Vandenkerckhove, J., Peys, E., Borremans, F. a. M., Sas, B., Wouters, J. and Martins, J. C. Tetrahedron 2009, 65, 4173–4181. 2. Sinnaeve, D., Hendrickx, P. M. S., Van Hemel, J., Peys, E., Kieffer, B. and Martins, J. C. Chemistry (Weinheim an der Bergstrasse, Germany) 2009, 15, 12653–62. 3. Sinnaeve, D., Delsuc, M.-A., Martins, J. C. and Kieffer, B. Chemical Science 2012, 3, 1284. [less ▲]

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See detailConstraints experienced by physical education teachers with overweight and obese students
Cloes, Marc ULg; Feron, Isaline; LEBRETHON, Marie-Christine ULg

Conference (2014, February 10)

Despite ‘antifat’ attitude of some PE teachers (Greenleaf & Weiller, 2005) and the PE public relations problem in regard to how obese students are treated (Irwin et al., 2003), it seems evident that this ... [more ▼]

Despite ‘antifat’ attitude of some PE teachers (Greenleaf & Weiller, 2005) and the PE public relations problem in regard to how obese students are treated (Irwin et al., 2003), it seems evident that this school subject represents a key element in the involvement of the education sector in the fight against the worldwide escalating global epidemic of obesity (Tappe & Burgeson, 2004). In fact, PE teachers consider that they lack of specific knowledge to implement instructional strategies dealing with overweight and obese students (Cloes & Ziant, 2009). Some authors proposed models to illustrate constraints that PE teachers encounter in their classes with obese students and their potential solutions (Cloes et al., 2013; Rukavina et al., 2010). On the other hand, data are missing when identifying those that are considered as their main concerns and the ways that they would prefer to receive some support regarding this specific topic. This study is focused on these two aspects. Five hundred thirteen PE teachers fulfilled an online questionnaire (Lickert scales) in which they had to determine (1) the perceived importance of 20 problems proposed by PE teachers and validated by 8 experts; (2) their relative interest toward the reception of support aiming to deal with those problems; (3) their preference for receiving information about the potential instructional strategies. Based on the answers, the top 3 problems are: (1) Students’ lack of awareness about the risks of overweight and obesity; (2) Constraints associated with the motor/physical disabling; (3) Parents’ lack of awareness about physical activity impact on health. Internet (3.49±.6/4), continuing professional development activities (3.29±.8/4), and educational info capsules (3.07±.8/4) were identified as the main resources that PE teachers would use preferentially. This study provides useful information for PE teachers’ educators who should develop now material to be shared with the practitioners. [less ▲]

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See detailAllo- and autoinhibition in barley and great brome: a laboratory study
Bouhaouel, Imen ULg; Gfeller, Aurélie; Fauconnier, Marie-Laure ULg et al

Conference (2014, February 08)

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See detailAnd the winner is ... When =f and pAj=f play hide-and-seek
Winand, Jean ULg

Conference (2014, February 07)

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See detailA diachronic analysis of the dynamic of two cities: Kisangani and Lubumbashi (Democratic Republic of Congo): How do the extension and/or of the densification of these cities impact the urban internal and peripheral ecosystems?
Andre, Marie ULg; Mahy, Grégory ULg; Lejeune, Philippe ULg et al

Poster (2014, February 07)

The dynamics of two cities between two years (2002 and 2010 for Kisangani; 2002 and 2008 for Lubumbashi, both part of the Democratic Republic of Congo) have been examined in order to estimate how their ... [more ▼]

The dynamics of two cities between two years (2002 and 2010 for Kisangani; 2002 and 2008 for Lubumbashi, both part of the Democratic Republic of Congo) have been examined in order to estimate how their extension and/or of the densification have impacted the urban internal and peripheral ecosystems. This study singularizes itself from the subjective ones by its quantified and objective approach based on landscape ecology. This discipline assumes that the landscape pattern description is important because, according to its central hypothesis called “pattern-process paradigm”, the ecological processes influence landscape structure and vice versa. Composition metrics, which are commonly used in landscape ecology, describe the pattern among other things in quantifying the presence and the number of patches from the various classes within the landscape. For each city two SPOT 5 images were classified with a oriented-object supervised approach; then built area proportion index, a composition landscape metric, has been evaluated in order to 1) identify the extent of each area (urban, suburban, rural) within the urban-rural gradient, 2) quantify the dynamic of the different areas in the urban-rural gradient during the last decade and 3) quantify the effect of a decade of urban and suburban growth on ecosystems. The similarities and differences between these cities, relevance and gaps in the method have then been identified and discussed. [less ▲]

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See detailContribution to the study of alliinase, the active principle of garlic
DETHIER, Bérénice ULg; Ponchaux, Julien; Laloux, Morgan et al

Poster (2014, February 07)

Alliinase is a crucial enzyme in the Allium genus. The conversion of its substrates, cysteine sulfoxides, into volatile thiosulfinates is an important mechanism in the defence of the plant. It also ... [more ▼]

Alliinase is a crucial enzyme in the Allium genus. The conversion of its substrates, cysteine sulfoxides, into volatile thiosulfinates is an important mechanism in the defence of the plant. It also provides the typical pungent flavour of garlic. As a matter of fact, the thiosulfinates decompose in a range of organosulfur compounds (OSC) known for their biological activities (antioxidant, anticancer, anti-diabetes properties, etc.). The environment of the decomposition of the thiosulfinates determines the type and amount of products released. A deeper knowledge of the conditions that form each OSC could help us in the preparation of garlic-based nutraceutics in the perspective of healthier food consumption. This study aims to improve the extraction and purification the enzyme alliinase in order to perform the reaction between the enzyme and its substrates and assess the potentialities of garlic preparations. Three methods have been applied to evaluate the efficiency of the extractions and purifications of the enzyme. A first idea of the purity of the enzyme is given by an electrophoresis separation of each sample on a polyacrylamide gel (SDS-PAGE). The protein content is then measured by UV-vis spectrometry with Lowry-Folin reagent for the coloration and BSA as an external standard. Finally, the specific activity is assessed by an indirect measure of the pyruvate (released as a co-product): the addition of NADH and lactate dehydrogenase turns the pyruvate in lactate, and the disappearance of NADH is measured by UV-vis spectrometry at 340 nm. The extraction of the enzyme from garlic was performed either by PEG 8000 precipitation or by ammonium sulphate precipitation. Two purifications were tested: affinity chromatography (on ConA) and size-exclusion chromatography. The combination of the ammonium sulphate process with the ConA chromatography provided the purest enzyme, with the best activity but a lower yield than the size-exclusion process. Finally the stability of the enzyme has been assessed at 4, -20 and -80 °C, showing that the enzyme could be kept at -80 °C for over 4 months without deterioration, while activity loss was observed at higher temperature. [less ▲]

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See detailEffect of sun-drying on flavonoïd composition and antioxidant activity of three dark fig varieties
Bachir Bey, M.; Richard, Gaetan ULg; Fauconnier, Marie-Laure ULg et al

Poster (2014, February 07)

The aim of the study was to investigate the effect of sun-drying on individual flavonoïd and antioxidant activities of three dark fig varieties (Azenjar, Bouankik, and Aberkane). Flavonoïd compounds were ... [more ▼]

The aim of the study was to investigate the effect of sun-drying on individual flavonoïd and antioxidant activities of three dark fig varieties (Azenjar, Bouankik, and Aberkane). Flavonoïd compounds were identified and quantified using high-performance liquid chromatography. The results showed that all samples significantly differed in their flavonoïd compositions. [less ▲]

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See detailOld inks: pigments extracted from plants
Despy, Jessica; Wymeersch, Noémie; Bouchat, Isabelle et al

in BOOK OF SHORT ABSTRACTS - POSTER PRESENTATIONS 19TH NATIONAL SYMPOSIUM ON APPLIED BIOLOGICAL SCIENCES (2014, February 07)

Thousands of years ago, natural pigments were discovered and they have been used ever since. Indeed, prehistoric people already used them to paint the walls of the caves in which they were living. A ... [more ▼]

Thousands of years ago, natural pigments were discovered and they have been used ever since. Indeed, prehistoric people already used them to paint the walls of the caves in which they were living. A significant example of this is the Cosquer cave (-19,000 to -27,000 years) located near Marseilles. Pigments and dyes can be classified into two broad categories and five families: natural pigments and dyes and those called artificial. The first one of these five families includes the mineral pigments. Among these we can find the clays (yellow ochre, red ochre, green clay, brown clay) and the stones like lapis lazuli (blue). The second and third families gather the organic dyes and pigments. Those that have vegetal origins like indigo (blue) and madder (red) compose the second family and those that have animal origins like cochineal (red) and kermes dyers (carmine) form the third family. One family includes pigments and dyes stemming from chemical reactions such as verdigris or red lead (family 4) and the other one is made of the miscellaneous inks such as iron-gall type who are vegetal and mineral one (family 5). All these pigments, although they have been used for centuries, have been replaced by synthetic dyes from the oil industry at the end of the 19th century. Indeed, they have the advantage of reproducibility of the properties unlike natural pigments. But the scarcity of oil causes a renewed interest in natural preparations. We report the extraction of pigments from plants. [less ▲]

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See detailInteractions of a potential plant elicitor mannolipid with plant model membranes
Polo Lozano, Damien ULg; Lins, Laurence ULg; Ongena, Marc ULg et al

Poster (2014, February 07)

The use of chemical pesticides causes problems for human health and environment. In this context, there is an increasing interest for alternative products such as biopesticides. Among them, elicitors act ... [more ▼]

The use of chemical pesticides causes problems for human health and environment. In this context, there is an increasing interest for alternative products such as biopesticides. Among them, elicitors act on the plants by inducing systemic resistance against diseases caused by fungal, viral, bacterial agents and insects. The target of the elicitors is supposed to be the plant plasma membranes (PPM). The main mechanisms of interaction of many elicitors involve proteic receptors but lipid-based elicitors (LBE) may preferably interact with the lipidic fractions of PPM. However there is no detailed information at the molecular level on the PPM-LBE interactions. Our work is focused on a original synthetic LBE composed of a mannoside linked to a myristic acid. It has potential elicitor activities as shown by the assays on tobacco root cells. These activities could be related to its interaction with the lipidic phase of PPM. Since PPM are complex entities, the analyses of the PPM- molecule interactions are quite difficult. In this context, these interactions were carried out using biomimetic membranes of PPM such as Langmuir monolayers and multilayers. The effects of our molecule on these membranar systems were investigated by biophysical and in silico approaches. [less ▲]

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See detailDevelopment of formulated elicitors to control bioagressors of wheat: which interests?
Le Mire, Géraldine ULg; Deleu, Magali ULg; Ongena, Marc ULg et al

Poster (2014, February 07)

Crop plants are constantly exposed to a wide range of environmental stresses that can cause major productivity loss. Fungicide treatments are the most efficient disease control methods used up to now ... [more ▼]

Crop plants are constantly exposed to a wide range of environmental stresses that can cause major productivity loss. Fungicide treatments are the most efficient disease control methods used up to now. However, the environmental and health issues caused by these chemicals make it urgent to develop safer methods for pathogen control. In the optic of a sustainable agriculture, several biocontrol tools have been developed during the last decades. Elicitors are increasingly subject to research as interesting alternatives to phytosanitary products. Yet, few efficient formulations exist on the market, and no product has been designed specifically to protect wheat crops. This study will thus focus on the the manipulation of host natural defenses through the use of elicitors as a preventive treatment against major wheat diseases such as Septoria tritici, Fusarium graminearum and Fusarium culmorum. [less ▲]

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See detailField bordering flower strips as source of lipids
Paul, Aman ULg; Danthine, Sabine ULg; Stephanie, Heuskin et al

Poster (2014, February 07)

Field bordering flower strips not just only improves the biodiversity but also serves as a source of beneficial compounds. Some of the plants in these strips can be really interesting source of lipids ... [more ▼]

Field bordering flower strips not just only improves the biodiversity but also serves as a source of beneficial compounds. Some of the plants in these strips can be really interesting source of lipids, the oils extracted from their seeds can be important for food, pharmaceutical and cosmetics industries. Six species of plants from flowering strips in Belgium were investigated for their seed oil content. The oil from seeds was extracted by cold extraction technique using chloroform/methanol in 2:1 ratio as solvent. Oil extraction from seeds of Red Clover (Trifolium pratense), Rough Hawkbit (Leontodon hispidus), Cow Parsley (Anthriscus sylvestris), St John’s Wort (Hypericum perforatum), Common Yarrow (Achillea millefollium) and Birdsfoot Trefoil (Lotus corniculatus) plant species was done on wet weight which came out to be 7.89±0.11%, 11.86±0.07%, 14.78±0.31%, 24.20±0.02%, 20.08±0.15% and 7.04±0.12% respectively. The physicochemical properties of the extracted oils were analyzed. Some of these oils can be of great commercial value. [less ▲]

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See detailFrom wood charcoals to trees: pitfalls and successes of the taxonomic identification in tropical contexts
Morin-Rivat, Julie ULg; De Weerdt, Joëlle; Hubau, Wannes et al

Poster (2014, February 07)

So as to document the past history of tropical forests, several palaeoenvironmental proxies have been used. For instance, charcoals from soil deposits provide a local signal of the evolution of the ... [more ▼]

So as to document the past history of tropical forests, several palaeoenvironmental proxies have been used. For instance, charcoals from soil deposits provide a local signal of the evolution of the vegetation together with snapshots of human interactions with the environment. As charcoal analyses are rare in tropical contexts, here we aim at presenting the different aspects of charcoal studies through their pitfalls and successes as well as the needs for further research. Charcoal analysis (anthracology) is a discipline initially from archaeobotany that consists in the analysis of pieces of charred wood primarily found in archaeological contexts but also in natural soil layers. Its goal is to identified the species that burnt during the past through the observation of the charred wood structure. Indeed carbonization, as the incomplete combustion of the ligneous material, preserves the wood structure. The identifications obtained through microscopic observations allow assessing past uses of wood and human impacts on the forest landscape. However, issues typically tropical exist: difficulties related to fieldwork accessibility, to sampling, to soil processing so as to collect the charcoals, difficulties related to the taxonomic identification because of the huge number of species and of the limited number of anatomical descriptions. New developments are nonetheless emerging for Central Africa with original anatomical descriptions, identification protocols and visual keys. [less ▲]

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See detailUse of Near Infrared Hyperspectral Imaging (NIR-HSI) and chemometric tools to dicriminate wheat roots and straws in soil
Eylenbosch, Damien ULg; Fernandez Pierna, Juan Antonio; Baeten, Vincent et al

Poster (2014, February 07)

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See detailInteractions between new phenolic glycolipids and model membrane
Sainvitu, Pauline ULg; Nasir, Mehmet Nail ULg; Crowet, Jean-Marc ULg et al

Poster (2014, February 07)

Model membrane based on phospholipids (PL) layers are useful to mimic properties of plasma membranes. The interactions between new synthesized phenolic glycolipids (PGL) and biological membrane are ... [more ▼]

Model membrane based on phospholipids (PL) layers are useful to mimic properties of plasma membranes. The interactions between new synthesized phenolic glycolipids (PGL) and biological membrane are crucial to determine their potential as drug candidates and their cytotoxicity . [less ▲]

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See detailBiofilter in aquaponics
Delaide, Boris ULg; Lambrechts, Paul Emile ULg; Willaert, Jean-François ULg et al

Poster (2014, February 07)

Aquaponics is a combination of aquaculture (fish farming) and hydroponics (horticulture). In this concept, the fish faeces and excreted ammonia are partially transformed into soluble nutrients which then ... [more ▼]

Aquaponics is a combination of aquaculture (fish farming) and hydroponics (horticulture). In this concept, the fish faeces and excreted ammonia are partially transformed into soluble nutrients which then are available for plants. Wastewater from aquaculture is filtrated by plants and return to the fish tank in a loop cycle. This strongly reduces the use of water and increases the economic efficiency with an additional production of plant, e.g. vegetables. From the hydroponics view, this combination allows important decreases in chemical nutrients use for plant grow. A central part of this system is the biofilter. The microorganisms that colonize it are essential to process the fish waste into soluble nutrients easily assimilated by plants. During this process, nitrifying bacteria convert free ammonia into nitrite and then nitrate. The first objective of this research will concern the identification and isolation of the main microorganism species involved by the dilution plating and metagenomics technics. The optimal conditions to process the fish waste will be determined for such microorganism. The efficiency of nitrite and nitrate production by these micro-organisms will be tested in different conditions (T°, pH, O2, water flow, support, etc..) in vitro at the lab scale and in aquaponics prototypes. [less ▲]

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See detailIMPLEMENTATION OF A METAL STRUCTURED PACKING IN A FUNGAL BIOFILM REACTOR FOR THE PRODUCTION OF A RECOMBINANT PROTEIN BY ASPERGILLUS ORYZAE
Zune, Quentin ULg; Delepierre, Anissa; Toye, Dominique ULg et al

in Communications in Agricultural and Applied Biological Sciences (2014, February 07)

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See detailIntegrated farming systems in Kinshasa (DRC) Diversity of agricultural practices
Mafwila Kinkela, Patrick ULg; BINDELLE, Jérôme; WILLEMS, E, Emilie et al

Poster (2014, February 07)

In Kinshasa in the Democratic Republic of Congo, integrated farming of livestock and fish farming is little documented while it is an interesting way of ecological intensification systems. After ... [more ▼]

In Kinshasa in the Democratic Republic of Congo, integrated farming of livestock and fish farming is little documented while it is an interesting way of ecological intensification systems. After identifying the density of fish ponds in the territory of the city using satellite images, about 200 farms with at least one pond and located in 2 in peri-urban and rural areas were surveyed to characterize the practical integration of the agricultural system. The preliminary results in one of the valleys indicate that the practice of agriculture in synergy with the pig and fish farming is a common practice although flow of components are still insufficiently integrated and some of them are not optimized . The fish - pig farming associations with or without vegetable production are 44 % of the sample. The identification of flow on farms showed that the manure of pigs is mainly used for crops (51%) or sold (28%), while a small part is used to fertilize the ponds. This may be explained by the predominant share of income (67%) devoted to vegetable production while sludge of ponds is rarely used to fertilize area of vegetable production. Residues of vegetable crops are rarely used to feed pigs and fish because of their limited availability. Feeding pigs and fish is based primarily on agro-industrial by-products such as wheat bran (81%) and the spent brewery grains (62%) and forages (62%). The presentation will analyze the results obtained in the three sites visited and outline opportunities for improvement. [less ▲]

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See detailUse of lipases for the kinetic resolution of lactic acid esters in heptane or in a solvent free system
Richard, Gaetan ULg; Nott, Katherine; Nicks, François et al

Poster (2014, February 07)

This poster illustrates the kinetic resolution of lactic acid esters using CAL-B as catalyst. The racemic mixture is resolved in heptane and even in a solvent free system.

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See detailUse of GC-MS in SIM-Scan mode for a selective quantification of polluting volatile organic compounds (VOC) in food industries
Eloundou Mballa, Pierre ULg; DETHIER, Bérénice ULg; Fauconnier, Marie-Laure ULg

Poster (2014, February 07)

The control of atmospheric emission discharges by food industries is classically achieved in two phases. The first one consists of sampling the target atmosphere followed by concentrating the volatile ... [more ▼]

The control of atmospheric emission discharges by food industries is classically achieved in two phases. The first one consists of sampling the target atmosphere followed by concentrating the volatile organic compounds (VOC) contained in a defined volume of this atmosphere on an adsorbing agent. These compounds are then thermally desorbed (TD) or desorbed with a solvent. In the second phase, the gas phase chromatogram (GC) will be coupled with mass spectrometry (MS) or flame ionization detector (FID) for compounds analysis. Quantitative analysis are usually achieved with solvent desorption followed by GC-FID. However, this mode imposes the dilution of the sample by a solvent and consequently may cause high detection thresholds as well as important matrix effect and possible interferences due to chemical reactions between analytes and the solvent. Besides, a preliminary qualitative analysis (GC-MS identification) is necessary. Combining TD-GC-MS allows very low detection thresholds to be reached, and the matrix effect and the interferences caused by products of the reactions between analytes and the solvent to be eliminated. The use of this combination in selected ion monitoring (SIM) mode allows targeting analytes via their characteristic ions, increasing their sensitivity and repeatability insuring more accuracy for simultaneous qualitative and quantitative analysis. This technique was experimented for seeking VOC in the atmosphere around food industries. [less ▲]

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See detailRhizobacterial volatile organic compounds implication in Brachypodium distachyon response to phosphorus deficiency
Baudson, Caroline ULg; Saunier de Cazenave-Mendaluk, Magdalena ULg; du Jardin, Patrick ULg et al

Poster (2014, February 07)

In agriculture, phosphorus (P) is considered as the second most growth-limiting macronutrient after nitrogen. However, P fertilizers are produced from non-renewable resources. In this context, sustainable ... [more ▼]

In agriculture, phosphorus (P) is considered as the second most growth-limiting macronutrient after nitrogen. However, P fertilizers are produced from non-renewable resources. In this context, sustainable production strategies have to be developed to enhance P use efficiency of crops, e.g. based on naturally occurring biotic interactions that limit the negative impacts of P deficiency in soils. Plant growth-promoting rhizobacteria (PGPR) have already revealed their ability to promote plant growth and tolerance to abiotic stresses through many mechanisms. Among them, the bacterial volatile organic compounds-mediated communication between plants and PGPR is still poorly documented. Our research project aims at studying the capacity of a model cereal plant (Brachypodium distachyon (L.) Beauv. Bd21) to face P deficiency in interaction with PGPR. The prerequisite of this project consists in characterizing Bd21 response to P deficiency by measuring plant biomass production and allocation, root system architecture, total phosphorus content, root-secreted and intracellular acid phosphatase activity under various P concentrations. Those results will allow us to define P-limiting conditions, in order to assess PGPR volatiles influence on plant response to P deficiency. This approach will use an ex-vitro co-cultivation system allowing volatiles-mediated interaction and should help us to unravel the ability of rhizobacterial volatiles to enhance plant tolerance to P deficiency. [less ▲]

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See detailINFLUENCE OF STEAM EXPLOSION ON THECRYSTALLINITY OF CELLULOSE FIBER
Jacquet, Nicolas ULg; Vanderghem, Caroline ULg; Danthine, Sabine ULg et al

Poster (2014, February 07)

The aim of the present study is to compare the effect of different steam explosion treatments on crystallinity properties of a pure bleached cellulose. Steam explosion process is composed of two distinct ... [more ▼]

The aim of the present study is to compare the effect of different steam explosion treatments on crystallinity properties of a pure bleached cellulose. Steam explosion process is composed of two distinct stages: vapocracking and explosive decompression. The treatment intensities is determined by a severity factor, established by a correlation between temperature process and retention time. The results show that steam explosion treatment has an impact on the crystallinity properties of pure cellulose fiber. When the severity factor is below 5.2, an increase of the overall crystallinity of the samples is observed with the treatment intensities. For higher intensities, a significant thermal degradation of cellulose lead to an important change in substrate composition, which lead to a further decrease of cellulose crystallinity. [less ▲]

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See detailAnalyzing relationships between cattle grazing behavior and pasture attributes using the inertial measurement unit of a mobile phone.
Andriamandroso, Andriamasinoro ULg; Lebeau, Frédéric ULg; Bindelle, Jérôme ULg

Poster (2014, February 07)

The recent technological developments are boosting the opportunities of accurate method to monitor resource use efficiency in agriculture and in their wake, precision livestock farming (PLF) has ... [more ▼]

The recent technological developments are boosting the opportunities of accurate method to monitor resource use efficiency in agriculture and in their wake, precision livestock farming (PLF) has experienced huge developments over the past decade. These developments focus on the optimization of individual performances of farm animals as opposed to herd management. The aim of this paper is to explore a method to detect accurately and to analyze changes in cattle's behaviors on pasture during grazing time using signals from the inertial measurement unit (IMU) of mobile devices as a possible tool to manage individual grazing behavior. Commercial iPhones or iPods, which include a 3-axis accelerometer, a gyroscope and a GPS sensor, are fitted on a halter and placed on the neck of grazing cows. The acquired IMU data are recovered using an open source application (Sensor Data, Wavefrontlabs) and analyzed in a “white-box” model of the cows’ movements. First results using time-domain analysis allowed the detection of grazing behaviors showed accuracies ranging between 84% and 96%, attesting the relevancy of the method. Refined signal processing method will improve the detection but will also inform more about the relative link between the behaviors and the pasture attributes such as sward height, composition and nutritive value. [less ▲]

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See detailUse of on-line flow cytometry for the characterization of microbial stress dynamics during the bioprocess
Brognaux, Alison ULg; Han, Shanshan; Sorensen, Soren et al

Poster (2014, February 07)

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See detailScreening of two agricultural genomic DNA libraries to seek new glycoside hydrolases
Stroobants, Aurore ULg; Portetelle, Daniel ULg; Vandenbol, Micheline ULg

Poster (2014, February 07)

Soils are very rich environments where the diversity of microorganisms is very high. These microorganisms play an important role in the degradation of organic matter with enzymes able to degrade it. This ... [more ▼]

Soils are very rich environments where the diversity of microorganisms is very high. These microorganisms play an important role in the degradation of organic matter with enzymes able to degrade it. This work aims to discover, by functional screening, new microbial glycoside hydrolases from soils collected in winter and spring in a winter wheat crop. The genomic DNA was extracted from both soils to construct two libraries in Escherichia coli. These libraries were then screened for beta-glucosidase activities on 2YT agar media containing 0.5% esculin and 0.1% ammonium iron (III) citrate. At this time, about 250.000 clones from each library have been screened. Two beta-glucosidases have already been found in the winter library while five beta-glucosidases and two glycosyltransferases were identified in the spring library. Sequence analyses with the BLASTX program revealed putative enzymes showing between 25% and 72% sequence identity with known enzymes and belonging to three glycoside hydrolase families (GH1, GH3 and GH20) and to two probably new glycosyltransferase families. Biochemical characterisation of the candidates at several pH values and temperatures, and with four substrates, is in progress. [less ▲]

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See detailPrerequisites for a Black locust genomic selection program
Verdu, Cindy ULg; Mengal, Coralie ULg; Henrotay, Frédéric ULg et al

Poster (2014, February 07)

The use of renewable resources as an alternative to fossil fuels has become a priority. Efficient use of forest as a resource for energy and green chemistry purposes require the development of suitable ... [more ▼]

The use of renewable resources as an alternative to fossil fuels has become a priority. Efficient use of forest as a resource for energy and green chemistry purposes require the development of suitable selected genotypes that are competitive and ready to meet the challenges of global change. In this context, the black locust, Robinia pseudoacacia L., is a very promising species which has many advantages in the context of current global change: high phenotypic plasticity, drought resistance, high biomass production and fixation of atmospheric nitrogen. The genetic improvement of woody species using traditional methods can take between 20 to 30 years. These times can be greatly reduced with the development of new selection methods such as genomic selection. Before starting a genomic selection program, it is necessary to 1) develop new molecular markers to achieve a very dense genetic map for genomic selection, 2) study the genetic diversity of the species present in Belgium and compare it with that of the native area, 3) study the structure and the relatedness of different populations, 4) establish a core collection gathering the most genetically diverse individuals, and 5) as black locust is an exotic species, verify its invasiveness in Belgium. These 5 steps will be detailed and the first results obtained will be discussed. [less ▲]

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See detailPaints based on renewable materials
Olive, Gilles ULg; Richel, Aurore ULg

in BOOK OF SHORT ABSTRACTS - POSTER PRESENTATIONS 19TH NATIONAL SYMPOSIUM ON APPLIED BIOLOGICAL SCIENCES (2014, February 07)

Paints, at the coating meaning, are known since a long time. Typically, paint is a dispersion of one or more powders (pigments and fillers) in a macromolecular substance ("resin"), called film-forming ... [more ▼]

Paints, at the coating meaning, are known since a long time. Typically, paint is a dispersion of one or more powders (pigments and fillers) in a macromolecular substance ("resin"), called film-forming material, diluted in solvents. Pigments are solid particles, used to give opacity and/or color. Today almost all pigments have a synthetic origin. The fillers are often natural compounds. Unlike pigments, fillers have low opacity and are colorless. These very cheap products achieve the required solid content under satisfactory economic conditions. Resins used in paints have the property of forming a continuous solid (hard or flexible) film under specific conditions. They are often called “resins”. They can be solid or liquid at room temperature. The solvents are used to control the viscosity of the paint in order to facilitate its production and application. The solvents used are volatile compounds. Additives are minor compounds (a few percent), whose function is to either promote or prevent some developments of the product. For example, surfactants improve the homogeneity of the dispersion. Some additives protect the film against mold or ultraviolet radiation, or against the formation of free radicals under the action of sunlight. Since the end of the 18th century most of those paints are petroleum-based. But the near disappearance of the petroleum causes a renewed interest in bio-based preparations. In this communication, we present an overview of bio-based alternatives. [less ▲]

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See detailEfficient computation of genomically-enhanced inbreeding coefficients
Faux, Pierre ULg; Gengler, Nicolas ULg

Poster (2014, February 07)

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See detailIncrease in Soil Macroporosity managed with Winter Ploughing - a preliminary results
Parvin, Nargish ULg; Chelin, Marie ULg; Hiel, Marie-Pierre ULg et al

Poster (2014, February 07)

Measurement of soil water retention capacity by the conventional pressure plate technique always gives a substantial view of soil porosity distribution. The structural orientation is observed in the ... [more ▼]

Measurement of soil water retention capacity by the conventional pressure plate technique always gives a substantial view of soil porosity distribution. The structural orientation is observed in the beginning (higher water retention at 9.8 to 98 hPa water head pressure indicates greater proportion of macroporosity) of the soil moisture characteristic curve obtained from the water retention measurement. Since, tillage practices generally increase soil porosity, the correlation between soil hydraulics and porosity distribution would expect to be different for different tillage systems. In general, macroporosity increase with the adoption of conservative tillage or no tillage system but the changes can be varied with the seasonal variation. In our study, winter ploughing retains more water at the range of 9.8 to 98 hPa than Strip tillage, No-till residues in and No-till residues out. So, we can conclude that there is certainly increase in macroporosity in ploughing than other conservation practices of reduced tillage and no tillage. [less ▲]

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See detailCan phytoestrogen-rich plants restore the image of livestock in terms of human health? Do they promise a differentiated quality products chain?
Daems, Frédéric ULg; Jasselette, Christophe; Lognay, Georges ULg et al

Poster (2014, February 07)

In a project named PhytoHealth, the development of analytical methods for studying the impact of phytoestrogens rich diet on the «health value» of animal products is in progress. Despite the ambiguous ... [more ▼]

In a project named PhytoHealth, the development of analytical methods for studying the impact of phytoestrogens rich diet on the «health value» of animal products is in progress. Despite the ambiguous image that have phytoestrogens, some of their metabolites seemed to have potentially beneficial effects to human health. In a first time, a microbial metabolite (equol) was selected and its metabolism in dairy cow is studied. A first method using the UPLC®-MS/MS technology has been validated and has achieved a screening of equol content in milk consumed in Wallonia. Equol was found in all milk samples analyzed and a significant difference between farming methods has been highlighted. A second analytical method to quantify the equol precursors was then developed and a study of forage plants consumed by Belgian dairy cows will be conducted to select the richest fodder varieties. Other methods will be developed to better understand the metabolism in the cow and estimate the impact of enriched milk on human health. An original approach involving the use of minipigs will be considered. In the end, creating of a differentiated quality animal products chain could be interesting for the consumer, but also recoverable for the producer. [less ▲]

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See detailThree aspects, One concept: Agroecology. Agroecological practices and human interactions for a new approach for science. An example at the Univeristy of Liege.
Hatt, Séverin ULg; Artru, Sidonie ULg; Boeraeve, Fanny et al

Poster (2014, February 07)

Critics are raising about conventional farming and its consequences on biodiversity, human health and society. As alternatives, novel models for agriculture are proposed, and among them Agroecology. Quite ... [more ▼]

Critics are raising about conventional farming and its consequences on biodiversity, human health and society. As alternatives, novel models for agriculture are proposed, and among them Agroecology. Quite often, Agroecology is seen as the application of ecological knowledge to the agricultural production. Indeed, this helps to develop more ecological farming practices favoring biodiversity to provide ecosystem services at multiple scales. Agroecology goes further in considering that the agricultural production is integrated in a food system guided by human interactions. This latter one takes into account socio-economic and political dimensions to develop new production systems. Doing so, it assures food security worldwide while preserving resources for future generations. Facing these ambitious objectives, academics are invited to elaborate a new approach for science in developing participatory and action-oriented approaches as well as multidisciplinarity. AgricultureIsLife is a research platform built up at the University of Liège (ULg). In 2013, 40 researchers (including 18 young researchers) from 16 research units of ULg were working in a multidisciplinary approach. About twenty research topics have been divided in four research axes of which objectives are to develop a more sustainable agriculture. The platform has the ambition to discuss its results to a large comity gathering the actors of the agricultural development. The aim of our work is firstly to present Agrocology as a concept made of three interrelated aspects. To illustrate it, the organization and objectives of the research platform AgricultureIsLife will be discussed in a second part. [less ▲]

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See detailPhysico-chemical properties and aroma profile of Acacia Honey produced in Romania
Madas, Mariana-Niculina ULg; Francis, Frédéric ULg; Marghitas, L.A. et al

in Communications in Agricultural and Applied Biological Sciences (2014, February 07), 79(1), 133-135

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See detailBiodiversity and ecosystem services: think functional!
Uyttenbroeck, Roel ULg; Hatt, Séverin ULg; Paul, Aman ULg et al

Poster (2014, February 07)

During the last years, several studies and reviews have considered the relation between biodiversity and ecosystem functioning or the provision of ecosystem services. Many studies found that plant ... [more ▼]

During the last years, several studies and reviews have considered the relation between biodiversity and ecosystem functioning or the provision of ecosystem services. Many studies found that plant functional traits and plant functional diversity (FD) are key drivers in this relation in terrestrial ecosystems. Researchers used different methods to obtain a gradient in plant FD to examine the effect on ecosystem services, going from observational studies of natural communities to synthetic assemblages. Furthermore, different methods exist to quantify plant FD going from simple functional trait richness to indices, distance-based frameworks and the division into FD components. In the AgricultureIsLife project, we set up a field experiment aiming to examine the biodiversity – ecosystem service relation in agricultural context. The experiment consists of perennial wildflower strips with different plant functional diversities in an arable field with conventional crop production. The wildflower strips were sown as synthetic assemblages but are subject to natural succession during the following years. We monitor the evolution of FD from the sowing to the establishment of a typical wildflower strip using Rhao’s quadratic entropy index to quantify FD. In addition, the flower strips will be monitored for four ecosystem services they are expected to provide: pollination, pest control, biodiversity support and provision of valuable compounds. [less ▲]

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See detailProfiles of the volatile organic compounds emitted by the masses of Abies nordmanniana somatic embryos at maintenance and maturation stages
Druart, Philippe; Michels, Franck ULg; Misson, Jean-Pierre et al

Poster (2014, February 07)

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See detailBiofilms from entomopathogenic fungi in mosquito control
Bawin, Thomas ULg; Boukraa, Slimane; Seye, Fawrou et al

Poster (2014, February 07)

Mosquitoes (Diptera: Culicidae) are zoonotic vectors of medical and veterinary importance. As part of an integrated vector control, metabolites secreted by entomopathogenic fungi could be developed as ... [more ▼]

Mosquitoes (Diptera: Culicidae) are zoonotic vectors of medical and veterinary importance. As part of an integrated vector control, metabolites secreted by entomopathogenic fungi could be developed as biopesticides. In this context, filamentous microorganisms growing on a support as biofilm in a liquid medium would offer several advantages in bioreactor regarding performances and metabolites recovery. The production of toxic metabolites by an entomopathogenic fungus Aspergillus flavus in such conditions was assessed. Three initial inoculum levels, i.e. 10^1, 10^3 and 10^6 spores/ml of PYG medium, have been tested in shake flask with or without support. Toxicity tests were performed on Culex quinquefasciatus larvae using dilutions of 1, 2, 4, 6, 8 and 10% of liquid cultures. The results indicated that A. flavus tends to form pellets in submerged culture; the size and the amount of pellets was affected by the initial inoculum level of spores. Under similar conditions, the filaments fixed on a support and didn’t appear in free form in the liquid. Toxicity tests revealed differences between both free and fixed forms. All combined conditions, LC50s ranging up to dilutions of 2.2 and 4.8% were observed within 48 hours. Secretomes could be compared between these culture conditions by proteomic and metabolomic approaches. [less ▲]

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See detailUsing micro-injection technique to assess fungal toxicity in mosquito control
Bawin, Thomas ULg; Boukraa, Slimane; Seye, Fawrou et al

in Communications in Agricultural and Applied Biological Sciences (2014, February 07), 79(1), 181-185

Topical application of insecticidal compounds allows directly exposing these substances on insect tissues and measuring their toxicity while ignoring many factors. However, this technique remains ... [more ▼]

Topical application of insecticidal compounds allows directly exposing these substances on insect tissues and measuring their toxicity while ignoring many factors. However, this technique remains difficult to apply on mosquito larvae considering their aquatic lifestyle. Micro-injection could be used for the direct deposition of toxic compounds in the larvae. Capillaries exhibiting an injection tip with an external diameter of 0.5 mm have been designed from silica tubes. For each treatment, a capillary is mounted on a pump connected to a flow rate regulator. Culex quinquefasciatus larvae were injected with 10^7 spores/ml of entomopathogenic fungi (Aspergillus clavatus, Metarhizium anisopliae, Metarhizium sp.). Mortalities were recorded daily during 72h. The distribution of spores stained with methylene blue and injected into the body of larvae was also observed according to the system described. Results showed that spores were distributed over the whole body. The injection of Aspergillus clavatus, Metarhizium anisopliae and Metarhizium sp spores induced corrected mortalities of 62%, 53% and 57% after 72h, and differed statistically from control groups. Finally, post-mortem emergences of filaments from dead larvae were observed in the case of the three fungal strains confirming spore viability. Injection of inactivated spores (or inert bodies of similar size) could help to reject the hypothesis of a response due to the presence of foreign bodies. [less ▲]

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See detailThe emergence of the possessive article pAy.f before the Amarna period
Sojic, Nathalie ULg

Conference (2014, February 07)

This presentation gives an overview of my research devoted to the Late Egyptian possessive article pAy.f. It aims at examining the uses of an element whose meaning evolved through time. Rather than ... [more ▼]

This presentation gives an overview of my research devoted to the Late Egyptian possessive article pAy.f. It aims at examining the uses of an element whose meaning evolved through time. Rather than looking for the very first occurrences of pAy.f in the Old Kingdom texts, my main concern is to analyze closely its progressive spread as well as to outline the gradual steps of its semantic evolution across the pre-amarnian corpus (15th-17th Dyn., c. 1650-1350 b.C.). On the one hand, I highlight the process by which this recent construction gradually encroaches on the older one, and on the other hand, I define the the meanings of pAy.f in relation to its distribution according to text genres. [less ▲]

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See detailIs the noxious Ambrosia artemisiifolia L. going to invade Belgium?
Ortmans, William ULg; Chauvel, Bruno; Mahy, Grégory ULg et al

Poster (2014, February 07)

Ambrosia artemisiifolia L. is an invasive species from North America, causing a health crisis in Europe due to its highly allergenic pollen. In France, there is a zone where the A. artemisiifolia ... [more ▼]

Ambrosia artemisiifolia L. is an invasive species from North America, causing a health crisis in Europe due to its highly allergenic pollen. In France, there is a zone where the A. artemisiifolia populations are naturalized and invasive. Outside this area, populations are more rare and do not seem to expand. We tested if the performances of A. artemisiifolia are varying with competition level, and among geographical zones. The results show that populations from Belgium and Netherlands are not less efficient than invasive populations for the measured traits. [less ▲]

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See detailQuantitative gas chromatography - mass spectrometry profiling of volatile organic compounds produced by barley (Hordeum distichon L.) roots according to plant age
Delory, Benjamin ULg; Delaplace, Pierre ULg; du Jardin, Patrick ULg et al

Poster (2014, February 07)

In chemical ecology, the roles played by root-emitted volatile organic compounds (VOCs) in biotic interactions and the quantitative analysis of such chemicals in root tissues remain poorly documented. In ... [more ▼]

In chemical ecology, the roles played by root-emitted volatile organic compounds (VOCs) in biotic interactions and the quantitative analysis of such chemicals in root tissues remain poorly documented. In this context, this study aims at developing a fully automated analytical methodology allowing both identification and accurate quantification of VOCs produced by roots of a monocotyledon plant species. Briefly, VOC emitted by crushed barley roots are successively trapped by dynamic headspace sampling on Tenax TA adsorbents, thermally desorbed and cryofocused, separated by gas chromatography (GC) and finally analysed by mass spectrometry (MS) in both SCAN and selected ion monitoring modes. Results show that barley roots mainly produce four volatile aldehydes, namely hexanal, (E)-hex-2-enal, (E)-non-2-enal and (E,Z)-nona-2,6-dienal. These molecules are well-known linoleic (C18:2) and linolenic (C18:3) acid derivatives produced via the lipoxygenase and the hydroperoxide lyase pathways of higher plants. Our findings contrast with analyses documented on aboveground barley tissues that mainly emit C6 aldehydes, alcohols and their derivative esters. Moreover, preliminary results indicate quantitative changes in the volatile profile contained in barley roots according to plant age. Multivariate statistical analyses are currently underway to quantitatively assess these changes using plants at five selected developmental stages ranging from germination to the end of tillering. [less ▲]

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See detailSreening of essential oils against rice pathogens isolated from Madagascar
Mamiharisoa Razanakoto, Léa ULg; De Clerck, Caroline ULg; Massart, Sébastien ULg et al

Poster (2014, February 07)

Four predominant isolated pathogens have been identified during survey of rice diseases in three regions in Madagascar. These pathogens were the bacteria Xanthomonas oryzae pv. oryzae and Pseudomonas ... [more ▼]

Four predominant isolated pathogens have been identified during survey of rice diseases in three regions in Madagascar. These pathogens were the bacteria Xanthomonas oryzae pv. oryzae and Pseudomonas fuscovaginae and the fungi Alternaria sp. and Curvularia lunata. These pathogens are causing significant yield reduction on rice, which is the staple food in this country. After the identification of those pathogens, the objective of this work was to identify appropriate control measures against them. Plants extracts has been traditionally used to control diseases in other plant species. Nowadays, the problem of residues of phytopharmaceutical product, reinforce the need for research on the development of natural plant extracts to control plant diseases. Madagascar has many endemic plant of interest and we have evaluated the antimicrobial properties of essential oils from Malagasy plants. The main object of this study is the in-vitro screening of essential oils to control the pathogens isolated on rice in Madagascar. Thirty nine essentials oils from Madagascar had been tested. Activity of essentials oils on Pseudomonas fuscovaginae, Alternaria sp. and Curvularia lunata had been tested using broth media and on agar medium for Xanthomonas oryzae pv. oryzae. The growth of the pathogen (bacteria and conidia) in the presence of the essential oil was evaluated and compared to a control. Nine of the 39 essentials oils showed interesting antimicrobial activity with an efficiency more than 70% against at least one bacterial pathogen. One essential oil inhibited the growth of the two pathogens tested. For fungal pathogens, three essential oils presented an efficiency of more than 70% against at least one fungal pathogen. These results confirm that some essential oils present an interesting antimicrobial activity. The in-situ confirmation on plant of this activity is currently ongoing. [less ▲]

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See detailarchiDART: a R package allowing root system architecture analysis using Data Analysis of Root Tracings (DART) output files
Delory, Benjamin ULg; Baudson, Caroline ULg; Brostaux, Yves ULg et al

Poster (2014, February 07)

In 2010, Le Bot et al presented a free and open-access software (Data Analysis of Root Tracings - DART) allowing the analysis of complex root system architectures from captured images, particularly across ... [more ▼]

In 2010, Le Bot et al presented a free and open-access software (Data Analysis of Root Tracings - DART) allowing the analysis of complex root system architectures from captured images, particularly across time series. Using this software, a user has to manually identify roots as a set of links. After vectorization of a root system, three final data sets (RAC, TPS and LIE) can be exported as table files containing several attributes for (a) each individual root (e.g. root length), (b) each observation day or (c) each point used to construct the vectorized root system respectively. These data sets can finally be used either to calculate derived root system architecture (RSA) parameters or to draw the root system architecture at selected observation dates. However when an experiment involves the analysis and comparison of many root systems, the calculation of RSA parameters for each data set and the drawing of the corresponding vectorized root systems become time-consuming. In this context, we developed a R package, called archiDART, allowing both the automatic calculation of common root architecture parameters and the X-Y plotting of vectorized root systems for selected observation dates. [less ▲]

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See detailEstimating daily yield and content of major fatty acids from single milking
Arnould, Valérie ULg; Reding, Romain; Delvaux, Charles et al

Poster (2014, February 07)

Reducing the frequency of milk recording and the number of recorded samples per test-day could be a solution in order to reduce costs of official milk recording. However, fewer samples lead to a decrease ... [more ▼]

Reducing the frequency of milk recording and the number of recorded samples per test-day could be a solution in order to reduce costs of official milk recording. However, fewer samples lead to a decrease in the accuracy of predicted daily yields. Unfortunately, the current published equations use the milking interval that is often not available and/or reliable in practice. The first objective of this study was to propose models using easily available traits. Therefore the milking interval was replaced by a combination of data easily recorded by milk recording. The second objective of this study was to enlarge the previous investigations to milk fatty acids (FA) in order to propose a practical method for estimating accurate daily milk, fat and major FA yields from single milking. The fit goodness of proposed models was evaluated based on the correlation values between the estimated and observed daily yields in addition to the calculation of the mean square error. Obtained results are promising. Correlation values were comprised between 96.4% and 97.6% when daily yield were estimated from morning milking, and from 96.9% to 98.3% when daily yield were estimated from evening milking. The combination of records related to lactation stage, month of test, milk yield, and fat could replace the milking interval effect. Because of their simplicity, proposed models would be easy to implement. [less ▲]

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See detailSimulations of a beta amphiphilic peptide as potential surfactant of membrane proteins
Crowet, Jean-Marc ULg; Dony, Nicolas ULg; Deschamps, Antoine et al

Poster (2014, February 07)

The peptide studied here was designed to form beta amphiphilic films with the aim to stabilize purified membrane proteins. This interaction has notably been followed by FRET. Hydrophobic and hydrophilic ... [more ▼]

The peptide studied here was designed to form beta amphiphilic films with the aim to stabilize purified membrane proteins. This interaction has notably been followed by FRET. Hydrophobic and hydrophilic residues are alternate and positively and negatively charged residues place respectively at the start end the end of the peptide. The peptide has been studied by atomistic and coarse grained molecular dynamics in water, chloroform and mixed solutions. The peptide was observed to spontaniously form beta films at the chloroform water interface. Moreover, when we simulate the interaction of this peptide with a membrane protein and with a membrane protein in a micelle of dodecylphosphocholine. The peptide was observed to form beta films at the membrane protein surface and even remove surfactants from the membrane protein surface. The simulations confirms the behaviour of this peptide observed in vitro and shows that it could be used instead of detergents. [less ▲]

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