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See detailNew ophthalmosaurids from Europe and Russia broaden the biodiversity of Early Cretaceous ichthyosaurs
Fischer, Valentin ULg

Poster (2011, November)

Ophthalmosauridae is a successful clade of ichthyosaurs that rapidly diversified during the Middle Jurassic. By Late Jurassic, Ophthalmosauridae were diverse, widespread, and formed an important component ... [more ▼]

Ophthalmosauridae is a successful clade of ichthyosaurs that rapidly diversified during the Middle Jurassic. By Late Jurassic, Ophthalmosauridae were diverse, widespread, and formed an important component of the marine trophic webs. By contrast, the record of Berriasian- Aptian ichthyosaurs is extremely poor, and all ichthyosaurs from that interval have been referred to a single genus, Platypterygius, until recently. This apparent diversity drop led numerous authors to recognize a severe ichthyosaur extinction at the end of the Jurassic that left ichthyosaurs as a small group on the decline. New specimens from poorly sampled time periods (late Valanginian, late Hauterivian and late Barremian) in Europe and Russia contradict this latest Jurassic extinction hypothesis and show that new and highly derived as well as typically ‘Late Jurassic’ ichthyosaurs roamed the Eurasian archipelago during the Early Cretaceous. Moreover, these new forms occupied ecological niches markedly different from that of Platypterygius, significantly broadening the disparity and ecological diversity of Cretaceous ichthyosaurs [less ▲]

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See detailLe Sommeil dans l'Etat Végétatif et de Conscience Minimale
Cologan, Victor ULg; Drouot, Xavier; Parapatics, Silvia et al

Poster (2011, November)

Présentation des résultats de l'étude du sommeil chez les patients cérébrolésés en état de conscience altéré.

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See detailUse of Bacillus subtilis S499 to control mould growth during malting of red sorghum from the D.R. of Congo
Bwanganga Tawaba, Jean-Claude ULg; Destain, Jacqueline ULg; Bera, François ULg et al

Poster (2011, November)

In this work, moulds growth was monitored during malting of a red sorghum from D.R. of Congo. Results obtained with chemical treatments [diluted alkalines: NaOH 0.2% (T1) and Ca(OH)2 0.1% (T2)] were ... [more ▼]

In this work, moulds growth was monitored during malting of a red sorghum from D.R. of Congo. Results obtained with chemical treatments [diluted alkalines: NaOH 0.2% (T1) and Ca(OH)2 0.1% (T2)] were compared with those of biocontrols [use of Bacillus subtilis S499 108 cells / mL: supernatant + cells (T3), cells (T4) and cells-free supernatant (T5)]. Chemical treatments have shown the highest fungal contamination levels, the highest malting loss, but better enzyme activities (α and β-amylases, limit-dextrinase, α-glucosidase and β-glucanase). The inhibition tests showed that the concentration of lipopeptides is correlated with the reduction of moulds growth. Malting trials with starters of Bacillus subtilis S499 showed that culture dilution affects the growth of moulds during red sorghum malting. The combination of a chemical treatment such as diluted NaOH with a biocontrol could be used to improve sorghum malts quality in terms of different enzymes activities and by reducing the level of fungal contamination. Key words: Bacillus subtilis S499, mould, sorghum malting [less ▲]

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See detailLutte biologique contre le doryphore à l'aide de la chrysope
Sablon, Ludovic ULg; Vandereycken, Axel ULg; Haubruge, Eric ULg et al

Poster (2011, October 27)

Le doryphore est le plus important défoliateur de pommes de terre. Lors de ces dernières années, une réapparition, certainement liée à l’augmentation des températures sous nos latitudes, a été constatée ... [more ▼]

Le doryphore est le plus important défoliateur de pommes de terre. Lors de ces dernières années, une réapparition, certainement liée à l’augmentation des températures sous nos latitudes, a été constatée. Face aux futures restrictions européennes en matière d’insecticides ainsi qu’aux exigences du consommateur, des techniques de lutte plus « vertes » sont à développer. Lors de nos tests en laboratoire, l’utilisation de la larve de la chrysope a permis une réduction efficace des œufs et larves de doryphores. Cela permet donc d’entrevoir une lutte entomophage contre le doryphore via l’utilisation d’un prédateur naturel propre à nos régions. [less ▲]

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See detailQuantitative capabilities of current commercial SPECT-CT systems
Bernard, Claire ULg; Nguyen, Daniel ULg; Seret, Alain ULg

Poster (2011, October 27)

Aim: To assess the quantitative capabilities of commercial SPECT-CT systems with their full 3D iterative reconstruction which includes resolution recovery, attenuation and scatter corrections. Materials ... [more ▼]

Aim: To assess the quantitative capabilities of commercial SPECT-CT systems with their full 3D iterative reconstruction which includes resolution recovery, attenuation and scatter corrections. Materials and methods: A NEMA NU2-1994 attenuation and scatter correction accuracy phantom, a cylindrical phantom with uniform part, cold and hot rods (diameter 4-25 mm), three uniform cylindrical phantoms of different sizes were scanned on a Siemens Symbia T6, a Philips BrightView XCT and a GE Infinia Hawkeye 4. For each phantom, activity concentration was obtained from the technetium-99m activity measured with an activimeter and its water volume. Emission projections were collected for 128 angles over 360 in 128*128 matrix (pixel size of 2.7 mm) using the 140 keV system usual energy window, and standard CT attenuation protocol was executed. Full 3D iterative reconstructions (Siemens Flash3D, Philips Astonish, GE Evolution) were performed. Residual fraction (RF) in the cold inserts of the NEMA phantom, contrast recovery coefficient (CRC) in the cold and hot rods were computed from the images. Regions of interest (ROI) of different sizes (60-100% of the phantom physical size) were drawn on the three uniform phantoms to obtain a calibration factor (CF). Results: RF dropped below 4% and CRC almost stabilized after 18 iterations. Hot rod CRC were above 90% for the rods with a diameter larger than 16 mm rising above 100% in some cases. Accurate quantification was shown feasible to within 5% or even less on some systems. CF was found to depend on both the phantom and the ROI sizes used for its determination, with variation of a few percents to more than 10%. The best phantom/ROI combination was also dependent on the system. Conclusion: With a careful design of the calibration procedure, quantification with these SPECT-CT systems and 3D iterative reconstruction seems to be feasible. However partial volume effect will remain a concern when object size drops below 2 cm. [less ▲]

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See detailPreparation and characterization of thermo-responsive gold nanohybrids
Liu, Ji ULg; Hurtgen, Marie ULg; Detrembleur, Christophe ULg et al

Poster (2011, October 25)

Stimuli-responsive nano-materials have been playing increasingly important roles in the biomedical field due to their ability to alter the physico-chemical properties in response to external stimuli, such ... [more ▼]

Stimuli-responsive nano-materials have been playing increasingly important roles in the biomedical field due to their ability to alter the physico-chemical properties in response to external stimuli, such as temperature, pH, ionic strength, magnetic field, etc. Nanohybrids bearing an inorganic core and thermo-responsive polymer shell are particularly applicable in target delivery and controlled drug release. Poly (N-vinylcaprolactam) (PNVCL) and its copolymers, exhibiting lower critical solution temperature (LCST) where the transition between hydrophilic and hydrophobic state happens, is one of the optimal choices for this core/shell structure. Here we present the in-situ fabrication of thermo-responsive gold nanohybrids coated with a novel poly(vinyl alcohol)-b-poly(N-vinylcaprolactam) (PVOH-b-PNVCL) block copolymer prepared by the cobalt-mediated radical polymerization (CMRP). The interaction between both PVOH and PNVCL segments and gold nanoparticles was confirmed by FT-IR spectra. A sharp thermo-induced phase transition with a good reversibility upon change in temperature was detected by DLS and UV/vis spectrometer. Furthermore, the presence of hydrophilic PVOH moieties endows the gold nanohybrids with improved colloidal stability above LCST without any flocculation detected, compared with the gold nanoparticles stabilized with PNVCL homopolymer. This kind of gold nanohybrids can be envisaged as a new drug delivery vehicle. [less ▲]

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See detailCharacterization of the interaction between nanoformulated drugs and model lipid membranes towards improved drug delivery systems
De Battice, Laura; Frost, Rickard; Sevrin, Chantal ULg et al

Poster (2011, October 25)

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See detailChanges in atmospheric composition discerned from long-term NDACC measurements: trends in direct greenhouse gases derived from infrared solar absorption spectra recorded at the Jungfraujoch station
Mahieu, Emmanuel ULg; Duchatelet, Pierre ULg; Zander, Rodolphe ULg et al

Poster (2011, October 25)

The University of Liège (ULg) is operating -under clear sky conditions- two state-of-the-art Fourier Transform Infrared (FTIR) spectrometers at the high-altitude research station of the Jungfraujoch ... [more ▼]

The University of Liège (ULg) is operating -under clear sky conditions- two state-of-the-art Fourier Transform Infrared (FTIR) spectrometers at the high-altitude research station of the Jungfraujoch (Swiss Alps, 46.5ºN, 3580m asl), within the framework of the Network for the Detection of Atmospheric Composition Changes (NDACC). Routine FTIR operation started in 1984. Since then, it has been continued without disruption, allowing collecting more than 45000 high-resolution broadband IR solar absorption spectra, between 2 and 16 µm, using either HgCdTe or InSb detectors as well as a suite of optical filters. Typically, the spectral resolutions achieved lie in the 0.003 to 0.009 cm-1 interval while signal-to-noise ratios of 1000 and more are reached. Numerous narrow-band IR spectra essentially recorded from 1976 to 1989 with grating instruments are also available. Their analyses with modern tools have recently started [Bader et al., 2011] and will be pursued to consistently extend our datasets back in the 1970s. Geophysical parameters are deduced from the ULg observational database either with the SFIT-1, SFIT-2 or PROFFIT-9 algorithm, allowing producing total column time series of the target gases. In addition, information on their vertical distributions with altitude can generally be derived when using SFIT-2 or PROFFIT-9 which both implement the Optimal Estimation Method of Rodgers [1990]. Presently, more than two dozen atmospheric species are systematically retrieved from the Jungfraujoch observations, allowing the monitoring of key constituents of the Earth's atmosphere which play important roles in stratospheric ozone depletion and/or in global warming. This communication will focus on the direct and major greenhouse gases available from our database, namely water vapor, CO2, CH4, N2O, tropospheric ozone, CFC-11, CFC-12, HCFC-22, CCl4, SF6, as well as CF4 which has recently been added to our targets list [Duchatelet et al., 2011]. Trends and associated uncertainties characterizing the available -and often multi-decadal- time series have been derived or updated with a statistical bootstrap resampling tool [Gardiner et al., 2008], they will be presented and critically compared with data available from the literature. [less ▲]

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See detailDescribing and modelling root and shoot growth and development in Brachypodium distachyon (L.) Beauv
Delory, Benjamin ULg; Delaplace, Pierre ULg; Gfeller, Aurélie ULg et al

Poster (2011, October 19)

Due to its small size, its short developmental cycle and its close phylogenetic relationship with the Triticeae tribe, Brachypodium distachyon (L.) Beauv. has been proposed as a model species for ... [more ▼]

Due to its small size, its short developmental cycle and its close phylogenetic relationship with the Triticeae tribe, Brachypodium distachyon (L.) Beauv. has been proposed as a model species for temperate cereals. In this context, this work aims to describe and model root and shoot growth and development of B. distachyon (Bd21-1) grown under controlled environmental conditions [22°C, 65% RH, 20h light, 95 µmol.m-2.s-1 (PAR, LED lighting)]. For this purpose, vernalized caryopses were sown in a substrate consisting of vermiculite and compost (80/20, v/v). Growth and development of the above and belowground parts were monitored for 70 days. Dry and fresh masses of plant organs were measured every seven days from sowing. Biomasses of adventitious and seminal roots were measured separately. The number of spikelets on the main stem and on tillers was also counted on plants aged of 70 days. The modelling of root and shoot growth was achieved by calibrating sigmoidal growth models to the mean biomass values measured at each day of analysis. For each plant organ, the growth model selected was the one with the lowest residual variance. Finally, developmental stages identified for B. distachyon were compared with those defined for cereal crops by Zadoks et al. (1974). Maximum rates of fresh and dry shoot biomass production were 29,5 and 14,2 mg.day-1 respectively. Based on modelling, these values seem to be reached 49 and 72 days after sowing. Results also show that the fresh mass of adventitious roots at day 42 is significantly higher than that of seminal roots. Maximum rates of fresh and dry root biomass production were 6,9 and 0,8 mg.day-1 respectively, and were reached after 37 and 43 days. [less ▲]

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See detailThe importance of distinguishing item and order memory for understanding short-term memory deficits in brain-damaged patients
Attout, Lucie ULg; VAN DER KAA, Marie-Anne ULg; GEORGE, Mercédès ULg et al

Poster (2011, October 18)

Selective verbal short-term memory (STM) deficits are rare and are often associated with a history of aphasia, raising doubts about the selectivity of these deficits. We explore here the distinction ... [more ▼]

Selective verbal short-term memory (STM) deficits are rare and are often associated with a history of aphasia, raising doubts about the selectivity of these deficits. We explore here the distinction between STM for item information (the items and their phonological and semantic characteristics) and STM for order information (the order of items within a list) to separate STM and language impairment. Recent models of STM consider that STM for item information depends upon activation of the language system, and hence item STM deficits should be associated with language impairment. By contrast, STM for order information is considered to recruit a specific system, distinct from the language system. Hence, order STM should be impaired in patients with language-independent STM deficits. We applied this rationale to the exploration of STM profiles of two patients with a history of aphasia, MB and CG. At the time of this study, patient MB showed poor digit and word STM spans associated with a mild impairment at the level of phonological input processing. Patient CG showed poor STM spans with no residual language impairment. A first experiment assessed STM for order and item information, using order and item probe recognition tasks. Patient MB showed severely impaired performance in the item condition (Z=-4.71; p<.001) but a milder deficit in the order condition (Z=-2.17; p<.05). CG on the other hand showed perfectly preserved performance for the item condition (Z=-0.43) but significantly slowed response times for the order condition (Z=-2.20; p<.05). In a second experiment determining item and order error proportions in an immediate serial recall task for six-word lists, MB showed a significantly increased proportion of item errors (Z=-3.24 and -2.6 for positions 5 and 6, respectively; p<.05) but not of order errors (Z=-1.47), while CG showed perfectly preserved item recall (Z=0.22) but an increase of order errors especially in final list positions (Z =-2.57 for position 6; p<.05). A third experiment assessed reconstruction of serial order for digit lists showing perfectly preserved performance in patient MB (Z=1.32) but severely impaired performance in patient CG (Z=-3.49; p<.05). A final experiment assessed new word learning performance, given that STM for order has been shown to be a critical determinant of vocabulary acquisition in children and adults. CG showed impaired new word learning performance in a paired associate word-new word learning experiment (Z=-3.29; p<.05) but not in a word-word learning control experiment (Z=0.13), while MB showed a more general verbal learning impairment (word-nonword: Z=-3.09, p<.05; word-word: Z=-4.8, p<.05). This study provides the first demonstration of a dissociation between STM for order and STM for item information in patients with a history of aphasia, and further shows that patients with residual language impairment are more likely to present impaired STM for item information which is considered to depend on the integrity of the language system. Order STM deficits on the other hand may represent what is commonly referred to as selective STM impairment, highlighting the importance of distinguishing between item and order STM processes when exploring STM deficits in aphasic patients. [less ▲]

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See detailRetour au travail après une absence de longue durée; étude de législation
Kéfer, Fabienne ULg; Cornelis, Sabine ULg

Poster (2011, October 15)

Panorama de la réglementation en vigueur en Belgique, des définitions des différents termes utilisés (incapacité, absence de longue durée, …) en support de la recherche, d'ordre médical, sur les pratiques ... [more ▼]

Panorama de la réglementation en vigueur en Belgique, des définitions des différents termes utilisés (incapacité, absence de longue durée, …) en support de la recherche, d'ordre médical, sur les pratiques existantes, des initiatives déjà envisagées, des expériences, des projets pilotes et des bonnes pratiques en Belgique et dans les autres pays européens et la mise en évidence des facteurs bloquants et favorisants le retour au travail des salariés absents de longue durée. [less ▲]

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See detailLes larves de taupins sont attirées par différentes sources de volatils racinaires
Barsics, Fanny ULg; Latine, Rémi ULg; Haubruge, Eric ULg et al

Poster (2011, October 13)

Grâce à des tests olfactométriques, nous voulons mettre en évidence la capacité de certains COVs d’origine racinaire à attirer ou repousser les larves de taupins. Nous montrons ici les premiers résultats ... [more ▼]

Grâce à des tests olfactométriques, nous voulons mettre en évidence la capacité de certains COVs d’origine racinaire à attirer ou repousser les larves de taupins. Nous montrons ici les premiers résultats obtenus grâce à des olfactomètres tubulaires, soit l’attraction par des COVs issus de racines hachées et l’attraction par le 2-pentylfuran, volatil contenu dans les racines d’orge. [less ▲]

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See detailLe taupin : un ravageur souterrain préoccupant
Barsics, Fanny ULg; Haubruge, Eric ULg; Verheggen, François ULg

Poster (2011, October 13)

Les larves de taupin représentent une menace pour un grand nombre de cultures céréalières et légumières. Elles s’attaquent aux racines, aux radicelles, aux tubercules, aux graines en germination et ... [more ▼]

Les larves de taupin représentent une menace pour un grand nombre de cultures céréalières et légumières. Elles s’attaquent aux racines, aux radicelles, aux tubercules, aux graines en germination et peuvent percer de part en part le collet, entraînant ainsi de graves lésions voire la mort des plants attaqués. Nous présentons ici ces insectes, les techniques de lutte actuellement envisageables, ainsi que notre approche de l’étude de ces insectes dans le but de mieux envisager la lutte intégrée à leur encontre. [less ▲]

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See detailThe fragile histidine triad gene regulates epithelial-mesenchymal transition associated with invasion of lung tumor cells.
Joannes, A; Bonnomet, Arnaud; Polette, Myriam et al

Poster (2011, October 10)

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See detailA dynamic in vivo of model of epithelial-to-mesenchymal transitions in circulating tumor cells and metastases of breast cancer
Bonnomet, Arnaud; Syne, L; Brysse, Anne et al

Poster (2011, October 10)

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See detailImplication of tight junctions in tumor invasion
Luczka, E.; Nawrocki-Raby, B; Birembaut, P et al

Poster (2011, October 10)

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See detailOn the origin of the 2-3 minutes quasi-periodicity in the Jovian magnetosphere
Bonfond, Bertrand ULg; Vogt, Marissa F.; Gérard, Jean-Claude ULg et al

Poster (2011, October 05)

Several kinds of periodicities have been observed at Jupiter since the first probes fly-by. However, pre- vious investigations mainly focused on the longer timescales, such as the 40 minutes (QP40) or the ... [more ▼]

Several kinds of periodicities have been observed at Jupiter since the first probes fly-by. However, pre- vious investigations mainly focused on the longer timescales, such as the 40 minutes (QP40) or the 2- 3 days quasi-periodicity. Here we describe the recent finding of the 2-3 minutes quasi-periodic occurrence of UV flares in the active region of the polar aurora. These observations are then compared to other measurements of such quasi-periodic behaviors in electron and magnetic field data and their probably common origin is discussed. [less ▲]

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See detailHydro and hydro-mechanical modelling of ventilation test in clayey rocks
Pardoen, Benoît ULg; Charlier, Robert ULg; Collin, Frédéric ULg et al

Poster (2011, October 03)

Long-term repository of radioactive waste in deep argillaceous geological media needs a good understanding of the host formation behaviour. Considering the safety function of the formation and the need of ... [more ▼]

Long-term repository of radioactive waste in deep argillaceous geological media needs a good understanding of the host formation behaviour. Considering the safety function of the formation and the need of low permeability, the behaviour of the excavation damaged zone (EDZ) is a major issue. Because drainage may modify the structure and the size of this zone, a ventilation test (SDZ) is realised by the French national radioactive waste management agency (ANDRA) in an experimental gallery of the Meuse/Haute-Marne underground research laboratory located in Callovo-Oxfordian claystone. The aim is to characterise the effect of the desaturation and possible resaturation of the damaged zone due to controlled ventilation. Numerical modellings are performed to reproduce the ventilation test. A biphasic flow model in unsaturated soil and an elasto-plastic constitutive law are used for the host formation. A nonclassical boundary condition has been developed in order to model the exchanges between the cavity and the rock. Numerical results show that it is possible to calibrate the models to obtain a satisfactory reproduction of the in situ experimental measurements and a better understanding of the fluid transfer around the gallery during the ventilation test. [less ▲]

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See detailChanges in termites feeding diets for gut micro-organisms selection and further cultivation
Bauwens, Julien ULg; Brasseur, Catherine ULg; Matteotti, Christel ULg et al

Poster (2011, October 02)

Termites gut may overcome important dietary perturbations, initial diversity acting as key point buffering effects on host, although termites possess their own enzymatic system. Some artificial diets ... [more ▼]

Termites gut may overcome important dietary perturbations, initial diversity acting as key point buffering effects on host, although termites possess their own enzymatic system. Some artificial diets permitted a simplification of the lower termites gut symbiotic system, which could be used as first step in symbionts isolation and cultivation. Preliminary assay of cultivation actually gave encouraging results. Proteomic proved to be suitable tool to investigate such a complex system. Nevertheless, for some symbionts very few genes are sequenced, which should lead to more targeted proteomic studies. Protein chromatography will allow to split up the proteome and more accurate analysis. [less ▲]

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See detailCharacterization of the interaction between nanoformulated drugs and model lipid membranes towards improved drug delivery systems
De Battice, Laura; Frost, Rickard; Sevrin, Chantal ULg et al

Poster (2011, October)

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See detailStructural Optimization: LBR-5 Software and its application
Motta, Dario; Boote, Dario; Caprace, Jean-David ULg

Poster (2011, October)

As well known already in earliest phases of a ship project many aspects and choices depend on the structural design which has been defined only at a preliminary level. This trend appears to be similar for ... [more ▼]

As well known already in earliest phases of a ship project many aspects and choices depend on the structural design which has been defined only at a preliminary level. This trend appears to be similar for merchant ships, passenger ships and motor yachts. Only in the final part of the project some shipyards begin to apply optimization processes, more or less sophisticated, in order to refine the structural design in view of reducing the weight and/or the construction cost. The weight in particular has a very important impact on pleasure vessels, both motor and sailing. Structural modifications suggested by such optimization procedures imply a number of second order changes in related items such as plant, outfitting and others. As a consequence the structural optimization could be particularly useful if it can be applied during the first stages of the project, this way avoiding very expensive time losses and changes caused by any structural modifications. The LBR-5 software has been successfully used to optimize hull structures of a 60 meters mega yacht. Differently from large ships, the mega yacht has not a “cylindrical body” in the central part of the hull. So, a new module of the software has been used in order to analyze several sections of the ship and to perform an overall optimization. For this application the optimization analysis has been carried out by different approaches: assuming the weight as the objective function a gain of about 8% has been achieved, while a least cost optimization allowed a reduction of 15%. [less ▲]

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See detailDetection of Auroral Emissions from Callisto’s Magnetic Footprint at Jupiter
Clarke, J. T.; Wannawichian, S.; Hernandez, N. et al

Poster (2011, October)

HST observations of Jupiter’s aurora in a large campaign reveal several cases where the main oval emission appeared at unusually low latitudes, making it possible to search for the first time for auroral ... [more ▼]

HST observations of Jupiter’s aurora in a large campaign reveal several cases where the main oval emission appeared at unusually low latitudes, making it possible to search for the first time for auroral emissions from the magnetic footprint of Callisto without the overlapping bright emissions from the main oval. Several cases have been found where point-source emissions have now been detected from locations consistent with Callisto’s magnetic footprint on Jupiter at a brightness of ten’s of kilo- Rayleighs. These observations confirm that there is an electrodynamic interaction between Callisto and Jupiter’s magnetospheric environment that is similar to those at Io, Europa, and Ganymede, which all have auroral footprints. The properties of the emissions and a comparison with other observations and theoretical expectations will be presented in this paper. [less ▲]

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See detailIn vitro ESR measurements: powerful tool to study toxic effects on cells
Grammenos, Angeliki ULg; Quoilin, Caroline ULg; Guelluy, Pierre-Henri ULg et al

Poster (2011, October)

Electron spin resonance spectroscopy (ESR) is a highly efficient technique able to access a wide range of information about the unfavourable effects caused by a chemical or a drug. ESR in spin labelling ... [more ▼]

Electron spin resonance spectroscopy (ESR) is a highly efficient technique able to access a wide range of information about the unfavourable effects caused by a chemical or a drug. ESR in spin labelling fits well in with the study of membranes and particularly with the changes in lipid bilayer organisation induced by drug. Our team previously developed a way to quantify the effective lipid bilayer microviscosity of cell membranes and consequently put in evidence the fluidity effect of the propofol. Recently, the importance of lipid raft domains has been shown due to their important role as a platform for signal transduction and protein sorting. We propose to highlight the effect of the Randomly methylated beta cyclodextrin (Rameb) on these domains on membrane model (liposomes) as well as on colon carcinoma cell line (HCT-116). Futhermore, ESR in spin trapping is used in order to identify and quantify the generation of Reactive Oxygen Species (ROS) in cells. An ESR study on human colon carcinoma cell line has highlighted the cytotoxicity of the photosensitizer pyrophephorbide-a methyl ester. Using an intracellular located spin trap (4-pyridyl 1-oxide-N-tert-butylnitrone, POBN), it has been shown that the photoexcitation of the dye is able to generate superoxide anions, hydroxyl radicals and singlet oxygen. Moreover, ESR is one of the most sensitive method for measuring cellular oxygen consumption. Our team has studied the alterations of oxygen respiratory in human tubular renal cells treated with an endotoxin (lipopolysaccharide, LPS). The incubation of HK-2 cells with LPS elicited a decreased in oxygen consumption suggesting a down-regulation of the cells metabolism. [less ▲]

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See detailModel of the Jovian magnetic field topology constrained by the Io auroral emissions
Hess, Sébastien; Bonfond, Bertrand ULg; Grodent, Denis ULg et al

Poster (2011, October)

The determination of the internal magnetic field of Jupiter has been the object of many studies and publications. These models have been computed from the Pioneer, Voyager, and Ulysses measurements. Some ... [more ▼]

The determination of the internal magnetic field of Jupiter has been the object of many studies and publications. These models have been computed from the Pioneer, Voyager, and Ulysses measurements. Some models also use the position of the Io footprints as a constraint: the magnetic field lines mapping to the footprints must have their origins along Io’s orbit. The use of this latter constraint to determine the internal magnetic field models greatly improved the modeling of the auroral emissions, in particular the radio ones, which strongly depends on the magnetic field geometry. This constraint is, however, not sufficient for allowing a completely accurate modeling. The fact that the footprint field line should map to a longitude close to Io’s was not used, so that the azimuthal component of the magnetic field could not be precisely constrained. Moreover, a recent study showed the presence of a magnetic anomaly in the northern hemisphere, which has never been included in any spherical harmonic decomposition of the internal magnetic field. We compute a decomposition of the Jovian internal magnetic field into spherical harmonics, which allows for a more accurate mapping of the magnetic field lines crossing Io, Europa, and Ganymede orbits to the satellite footprints observed in UV. This model, named VIPAL, is mostly constrained by the Io footprint positions, including the longitudinal constraint, and normalized by the Voyager and Pioneer magnetic field measurements. We show that the surface magnetic fields predicted by our model are more consistent with the observed frequencies of the Jovian radio emissions than those predicted by previous models. [less ▲]

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See detailSel-medication of regular headache : a community pharmacy-based survey
Mehuys, E; Paemeleire, K; Van Hees, Thierry ULg et al

Poster (2011, October)

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See detailInvestigation of mevalonate pathway in aphids
Vandermoten, Sophie ULg; Yu, Wenjuan; Chen, Julian et al

Poster (2011, October)

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See detailDonnées épidémiologiques sur la santé bucco-dentaire chez des enfants scolarisés en région liégeoise
GEERTS, Sabine ULg; Gueders, Audrey ULg

Poster (2011, October)

La prévalence carieuse chez les enfants fait l’objet de nombreuses publications émanant de l’OMS. Ainsi, nous disposons de nombreuses données épidémiologiques issues de divers pays et concernant la santé ... [more ▼]

La prévalence carieuse chez les enfants fait l’objet de nombreuses publications émanant de l’OMS. Ainsi, nous disposons de nombreuses données épidémiologiques issues de divers pays et concernant la santé bucco-dentaire des enfants. Néanmoins, force est de constater que peu d’études ont été réalisées en Belgique et de par ce fait, les données concernant la maladie carieuse et les besoins de traitement chez les enfants Belges restent très limitées. Une étude pilote a été menée par l’équipe du Service de dentisterie conservatrice de l’université de Liège afin de tenter de pallier à ce manquement. L’objectif de cette enquête clinique était de répertorier les facteurs de risques de la maladie carieuse et de recenser les épisodes carieux (présents et passés) chez des enfants âgés entre 6 et 13 ans. Un dépistage clinique a été mené dans 2 écoles de la région liégeoise et a intéressé 306 enfants. D’une part, nos résultats ont montré que la sévérité de l’indice CAO/D et de l’indice cao/d répondaient parfaitement aux objectifs fixés par l’OMS en 1981 (CAO/D < 3) mais qu’ils étaient loin de rencontrer ceux fixés pour 2020 (CAO/D < 1,5). D’autre part, il ressort de notre enquête que peu de jeunes patients sont indemnes de caries (16 %). En effet 84 % des patients examinés avaient déjà présenté un ou plusieurs épisodes carieux. Toutefois, nos résultats tendent à montrer que la maladie carieuse est significativement plus fréquente en denture de lait qu’en denture définitive (p < 0,001). En conclusion, notre étude pilote n’apporte aucun élément neuf dans la connaissance du processus carieux et de son dépistage mais elle a au moins le mérite de planter les premiers jalons qui conduiront à une meilleure connaissance de l’état de santé bucco-dentaire chez des enfants scolarisés en région liégeoise. [less ▲]

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See detailAROUSAL, EXPERIENCES, AND PSYCHO-EMOTIONAL MANAGEMENT OF THE NORMS’ CONFLICTS IN AFRICAN POSTCOLONIAL CONTEXT: CASE STUDY OF THE SUCCESSION PRACTICE IN CAMEROON
Bomda, Joseph ULg

Poster (2011, October)

More than a half-century after its independence, Cameroonians, like other African people, are experiencing many conflicts of norms in their succession practices. Among other conflicts, one can mention: 1 ... [more ▼]

More than a half-century after its independence, Cameroonians, like other African people, are experiencing many conflicts of norms in their succession practices. Among other conflicts, one can mention: 1. “Residual” or Interreligious conflict between Christians, Muslims, and Animists. 2. “Virtual” conflicts between Anglophone and Francophone people. 3. But the main source of conflicts is the “Ordinary” or Interpersonal conflicts between ancestral and modern laws (of French or English inspiration), because both are legally accepted. SEEING THE CONFLICTS BETWEEN ANCESTRAL AND MODERN LEGAL NORMS RELATED TO SUCCESSION, 1. What do the victims of such conflicts experience from psycho-emotional point of view? 2. How do they manage these experiences of conflicts? 3. In which way can these experiences and their management contribute to the debates on social psychology? [less ▲]

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See detailDefining Antonymy by studying Co-occurrences in Context (2)
Steffens, Marie ULg

Poster (2011, October)

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See detailIMPACT OF SLUDGE CONDITIONING ON MECHANICAL DEWATERING AND CONVECTIVE DRYING
Bazzaoui, R.; Fraikin, Laurent ULg; Groslambert, Sylvie ULg et al

Poster (2011, October)

Management of sludge produced within wastewater treatment plants hasbecome a key issue. After thickening, the removal of remaining water using mechanicaldewatering and/or thermal drying is essential ... [more ▼]

Management of sludge produced within wastewater treatment plants hasbecome a key issue. After thickening, the removal of remaining water using mechanicaldewatering and/or thermal drying is essential before any type of valorization. Polymersare usually employed in the conditioning step in order to promote particle aggregation,making the dewatering easier. In this work the impact of the polymer dosage and natureon dewatering and convective drying of sludge is studied. Results clearly show the impactof conditioning on dewatering performances, however no effect on drying has beenobserved within the range of tested experimental conditions. [less ▲]

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See detailContribution à l’évaluation du taux de radicaux libres présents dans les résines composites après photopolymérisation
BOLETTE, Amandine ULg; Gueders, Audrey ULg; Geerts, Sabine ULg

Poster (2011, October)

Depuis quelques années, les composites photopolymérisables de restauration sont devenus de plus en plus performants que ce soit sur le plan esthétique ou sur le plan mécanique. Les défauts majeurs de ces ... [more ▼]

Depuis quelques années, les composites photopolymérisables de restauration sont devenus de plus en plus performants que ce soit sur le plan esthétique ou sur le plan mécanique. Les défauts majeurs de ces matériaux font l’objet de nombreuses recherches aboutissant à leur diminution ou leur miniminisation ou encore à une amélioration franche des propriétés du composite. Aujourd’hui, le degré de conversion des monomères résineux intéresse certains chercheurs et notamment parce qu’un taux de monomères résiduels trop important peut interférer avec les propriétés du matériau de restauration. En corollaire à ces recherches, certains ont orienté leurs expérimentations sur une mesure indirecte du taux de conversion en évaluant le taux de radicaux libres après la polymérisation. Compte tenu que les radicaux libres peuvent se révèler cytotoxiques pour l’organe dentaire et la gencive mais aussi qu’ils peuvent occasionner un préjudice esthétique et/ou diminuer la résistance mécanique des restaurations, les radicaux libres qui persistent après la polymérisation des composites traduisent une réaction de prise incomplète voire même insuffisante. Le but de notre étude était d’évaluer indirectement le degré de conversion de 4 composites actuellement commercialisés en mesurant, au moyen de la résonance électro-paramagnétique (RPE), le taux de radicaux libres présents après la photopolymérisation des incréments de composites. Dans notre expérimentation, différents composites, différentes teintes, différentes épaisseurs d’incréments et différentes lampes à photopolymériser ont été étudiés. Les résultats ont montré que pour tous les composites testés, le taux de radicaux libres augmentait entre le temps t0 (juste après l’irradiation lumineuse) et le temps t15’ (15 minutes après l’irradiation lumineuse) ce qui tend à montrer que la polymérisation se poursuit bien après la fin de l’irradiation lumineuse. Entre les temps t15’ et t60’, le taux de radicaux libres diminue pour tous les composites testés et tend à retourner à la valeur observée au temps t0 (respectivement pour les différents composites testés). Pour 3 des 4 composites testés, ces valeurs restent alors inchangées au temps t120’. Lorsque les mesures ont été réalisées 48 h après la photopolymérisation des différents composites, dans tous les cas, les taux de radicaux libres étaient supérieurs à ceux rapportés aux temps t0, t60 et t120. En conclusion, notre étude corrobore les résultats d’autres études en montrant que la polymérisation des composites se poursuit au-delà du moment de l’irradiation lumineuse. En fait, nos résultats suggèrent que le taux de conversion des composites n’atteint son maximum que plusieurs heures après l’irradiation lumineuse du matériau photopolymérisable. [less ▲]

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See detailDynamic magnetic resonance perfusion: influence of the cardiac cycle on left ventricle and myocardial signal intensity measurements
BROUSSAUD; AOUCHRIA, S; MANCINI, ISABELLE et al

Poster (2011, October)

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See detailInhibition of Experimental Corneal Neovascularization by Sunitinib Administration
Detry, Benoît ULg; Blacher, Silvia ULg; Erpicum, Charlotte ULg et al

Poster (2011, October)

Cornea engraftment is the most common organ transplantation practiced around the world. The cornea is totally devoid of blood or lymphatic vessels, except in a peripheral zone called the limbus. This ... [more ▼]

Cornea engraftment is the most common organ transplantation practiced around the world. The cornea is totally devoid of blood or lymphatic vessels, except in a peripheral zone called the limbus. This property, named “corneal angiogenic privilege”, is conserved among all mammals to maintain cornea transparency and optimal visual acuity. In pathological conditions such as trauma, infections or hypoxia, blood and lymphatic vessels can grow into the avascular cornea, reducing visual acuity. In case of keratoplasty, it also considerably increases the risk of cornea graft rejection and is so considered as a high-risk keratoplasty. Treatments improving cornea survival after transplantation need to be developed, notably aiming at blocking corneal neovascularization. Here, we evaluated the efficacy of Sunitinib, a broad-spectrum tyrosine kinase receptor inhibitor, to reduce experimental corneal neovascularization. Cornea vascularization was induced by thermal cauterization applied in the center of C57Bl6 mice cornea, daily feeded with 40mg/kg Sunitinib or vehicule. Corneas were immunolabeled as whole mounts for CD31 and Lyve-1 to evidence blood and lymphatic vessels, 7, 11 and 17 days after cauterization. Whole mount pictures were analyzed by computer-assisted quantification, and relative vascular area, end-point density, node density, length density and maximal length of the vessels were determined to finely characterize blood and lymphatic vascular networks. We observed an inhibition of angiogenesis after 17 days in Sunitinib treated mice, where blood vessel relative surface, end-point density, branching density and length density were 1.8-fold decreased. Maximum length of blood vessels was also significantly reduced in the Sunitinib treated group at days 11 and 17. Lymphangiogenesis was strongly inhibited from day 6 to day 17 after cauterization where all parameters, except maximum length of lymphatic vessels, were significantly decreased. In case of transient Sunitinib administration (feeding during the 7 first days), we did not observe any reduction in the extent of blood or lymphatic networks developing 21 days after lesion induction. In vitro experimentations using the aortic and lymphatic ring assays showed a strong angiogenesis inhibition induced by Sunitinib while lymphangiogenesis was not inhibited. Our results show that the use of Sunitinib can strongly affect corneal neovascularisation and could enter in early treatment of such eye lesions to avoid vision loss and risk of cornea graft rejection. However, a punctual use of such tyrosine kinase inhibitor is not sufficient to stem neovascular reaction. In vitro experimentations show strong angiogenesis inhibition but normal lymphangiogenesis, suggesting indirect inhibitory effect of Sunitinib on corneal lymphangiogenesis. [less ▲]

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See detailCO2 exchange above a cultivated savanna in sudanian region in northern part of Benin (West Africa)
Ago, Expédit Evariste ULg; Agbossou, Euloge; Galle, Sylvie et al

Poster (2011, October)

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See detailAIRE polymorphisms induce variable extent of apoptosis on melanoma-specific CD8+ T lymphocytes.
Conteduca, Giuseppina ULg

Poster (2011, October)

AIRE regulates thymocyte selection by inducing the expression of tissue-restricted self antigens (TRAs) in medullary thymic epithelial cells (mTECs). MAGE antigens are among TRAs regulated by AIRE. Single ... [more ▼]

AIRE regulates thymocyte selection by inducing the expression of tissue-restricted self antigens (TRAs) in medullary thymic epithelial cells (mTECs). MAGE antigens are among TRAs regulated by AIRE. Single nucleotide polymorphisms (SNPs) of AIRE gene have been reported in humans but their impact on repertoire selection of tumor antigen-specific T lymphocytes is unknown. We report here that the rs1800522 SNP of human AIRE gene is present in mice and that the relative T or C allelic variants differently regulate MAGEB2 gene expression in mTECs. The C allelic variant, protective in humans against melanoma, induces lower MAGEB2 expression than the T allele. When mouse mTECs bearing the TT genotype were gene targeted to substitute the T with the C allelic variant, the co-culture of wild type or transgenic mTECs with MAGEB2-specific syngeneic T cells induced reduced extent of apoptosis and increased frequency of MAGEB2-specific viable T lymphocytes in T cells cultured with mTECs bearing the CC with respect to the TT genotype. These findings demonstrate that alternative allelic variants of AIRE SNPs may differently modulate the T cell repertoire specific against melanoma cells and subsequently may be linked to a different level of suceptibility to a neoplastic disease such as melanoma. [less ▲]

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See detail21st century Antarctic surface mass balance downscaling from global circulation models
Agosta, Cécile ULg; Favier, Vincent; Genthon, Christophe et al

Poster (2011, October)

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See detailThe energy the auroral electrons in Saturn's atmosphere : remote sensing and thermal consequences
Gérard, Jean-Claude ULg; Gustin, Jacques ULg; Grodent, Denis ULg et al

Poster (2011, October)

Saturn’s north aurora has been observed between January and May 2011 with the Hubble Space Telescope. The objective was to collect spatially resolved spectra at the different local time from dawn to dusk ... [more ▼]

Saturn’s north aurora has been observed between January and May 2011 with the Hubble Space Telescope. The objective was to collect spatially resolved spectra at the different local time from dawn to dusk and compare them with laboratory or synthetic spectra. For this purpose, HST was programmed to slew from mid-latitudes through the auroral oval up to above the limb while collecting data in the timetag mode. The spectra show signatures of absorption by hydrocarbons present above the peak of the auroral emission. The amount of absorption and implications in terms of penetration of the auroral electron beam into Saturn’s atmosphere will be discussed and compared with other determinations of the altitude of the aurora. The effects of the auroral heat import on the thermal structure of the atmosphere both at high and low altitudes will be examined in the light of these results. [less ▲]

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See detailL'entrepreneuriat féminin au Maroc: Quelles sont les variables contextuelles qui influencent l'entrepreneuriat?
Salman, Noura ULg; El abboubi, Manal; Henda, Sana

Poster (2011, September 30)

L’objectif principal de cet article est d’explorer les fondements de l’entrepreneuriat féminin au Maroc et de présenter les modèles existants. Ce qui nous amène à poser les questions suivantes : « Quels ... [more ▼]

L’objectif principal de cet article est d’explorer les fondements de l’entrepreneuriat féminin au Maroc et de présenter les modèles existants. Ce qui nous amène à poser les questions suivantes : « Quels sont les variables contextuelles et socio-économiques qui influencent l’entreprenariat au Maroc ? » et « qui sont ses femmes qui ont choisi d’entreprendre au féminin, en bravant courageusement les différents obstacles socio-culturelles qui caractérisent la société marocaine? ». Présenté ainsi, notre recherche entend dresser un état de l’art des différentes variables pouvant expliquer les composantes de l’entrepreneuriat féminin au Maroc et de conceptualiser ses mécanismes opérationnels afin de proposer des pistes de réflexions adaptées au contexte marocain et applicables par les femmes entrepreneures. [less ▲]

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See detailMicroorganisms in Karsts: a case study in St Anne cave, Belgium
Carnol, Monique ULg; Willems, Luc ULg; Malchair, Sandrine ULg

Poster (2011, September 30)

Despite the importance of microorganisms as geochemical agents over geological times, their extended metabolic diversity and their essential role in element cycles (i.e. mineral dissolution, precipitation ... [more ▼]

Despite the importance of microorganisms as geochemical agents over geological times, their extended metabolic diversity and their essential role in element cycles (i.e. mineral dissolution, precipitation, oxido-reduction processes), microbial community composition and processes as well as their ecological role in karst environments are poorly known. While little was published on cave-dwelling microorganisms until the early 1990s, it is now recognized that microorganisms may mediate many important mineral transformations, originally considered to be inorganic in nature. Indeed, recent evidence (Northup & Lavoie, 2001) proved the implication of microorganisms in karstification through precipitation and dissolution processes, resulting in the deposition of carbonate speleothems, silicates, iron or manganese oxides, sulphur compounds and nitrates and in the breakdown of limestone walls. In this poster, we review some potential processes and signs of microbial activity in caves. We present results of a study on the microbial diversity in the ‘St Anne’ cave, Belgium. We focused on ammonia-oxidizing bacteria (AOB), which are responsible for the first, acidifying step of the nitrification process. Chemical composition of the water, numbers of cultivable bacteria (free and particle-associated bacteria) and the diversity of AOB were studied in waters and sediments of the ‘Chawresse’ (underground river in St Anne), on the cave wall and in the soil aboveground. The use of molecular techniques, based on direct ADN extractions, provide more detailed information on the microbial diversity of an environment, as culture-based techniques retrieve only about 1% of bacterial species present in the environment. Bacterial counts showed that most cultivable bacteria were associated with suspended particles and that their numbers decreased underground. Molecular analyses revealed the presence of AOB in the karst system. Comparison of aboveground and belowground diversity also indicated the possibility of a specific endokarst AOB community. Further research perspectives will be discussed. <br /> <br /> <br />Northup, D.E. and Lavoie, K.H. 2001. Geomicrobiology of caves: A review. Geomicrobiology Journal, 18(3):199-220. [less ▲]

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See detailTraçabilité du bois et place des Forêts Communautaires camerounaises au sein du processus FLEGT
Beauquin, Antoine; Doucet, Jean-Louis ULg; Julve Larrubia, Cécilia et al

Poster (2011, September 29)

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See detailEvidencia de determinantes de patogenia en las regiones Long Terminal Repeats (LTRs) del genoma del virus de la leucemia bovina (BLV)
Rodriguez, Sabrina ULg; Trono, K.; Jones, L.R.

Poster (2011, September 26)

Evidencia de determinantes de patogenia en las regiones Long Terminal Repeats (LTRs) del genoma del virus de la leucemia bovina (BLV) Sabrina M. Rodríguez1*, Karina Trono2, Leandro R. Jones3 1 Molecular ... [more ▼]

Evidencia de determinantes de patogenia en las regiones Long Terminal Repeats (LTRs) del genoma del virus de la leucemia bovina (BLV) Sabrina M. Rodríguez1*, Karina Trono2, Leandro R. Jones3 1 Molecular and Cellular Epigenetics, Interdisciplinary Cluster for Applied Genoproteomics (GIGA), University of Liège (ULg), Belgium. 2 Instituto de Virología, CICVyA, Instituto Nacional de Tecnología Agropecuaria INTA-Castelar, CC 25 (1712), Castelar. 3 División de Biología Molecular, Estación de Fotobiología Playa Unión, CC 15, Rawson, Chubut 9103, Argentina. *E-mail: sabrina.rodriguez@ulg.ac.be El resultado de la infección por el virus de la leucemia bovina (BLV) es diverso. La mayoría de los animales infectados resultan portadores asintomáticos (AL) y cerca del 30% desarrolla una condición benigna denominada linfocitosis persistente (LP). La forma tumoral o linfosarcoma (LS) afecta a un 1-5% de los bovinos infectados. Las bases genético-moleculares del desarrollo de las distintas formas clínicas son desconocidas. Las Repeticiones Terminales Largas (Long Terminal Repeats, LTR) del genoma viral constituyen determinantes genéticos de patogenia en el caso de otros retrovirus. Sin embargo, esta posibilidad no ha sido evaluada para el BLV. Los análisis para probar la correlación entre los caracteres clínicos y genotípicos entre especies deben ser corregidos incluyendo la filogenia del grupo. De otra manera, la historia evolutiva compartida puede comprometer la independencia estadística del análisis. Sobre estas bases, el objetivo de este trabajo consistió en estudiar la influencia de las variaciones genéticas de las regiones regulatorias LTR del BLV en el desarrollo de las diferentes formas clínicas de la infección mediante métodos comparativos filogenéticos, cladísticos y probabilísticos. Con este fin, se secuenció la región 5´LTR de 40 provirus obtenidos a partir de bovinos naturalmente infectados con BLV que presentaron las diferentes formas clínicas (AL, PL, LS). Fueron identificadas siete posiciones polimórficas que mostraron una asociación aparente con la presentación clínica. Una reconstrucción de la filogenia del grupo fue realizada a partir de las secuencias de la región env obtenidas para 28 de los 40 provirus estudiados en este trabajo. En conjunto, los análisis comparativos cladísticos y probabilísticos basados en el alineamiento empírico de las secuencias y la filogenia del grupo sugieren que las posiciones 41 y 56 del 5´LTR podrían estar correlacionadas con la presentación clínica. Los análisis probabilísticos indicaron además una asociación con la patogénesis viral para las posiciones 373, 450, 494 y 505, aunque los soportes estadísticos correspondientes fueron menores en comparación con los soportes obtenidos para las posiciones 41 y 56. Estas observaciones indican que las regiones LTR del BLV podrían constituir determinantes de patogenia. [less ▲]

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See detailNeuropeptides and endogenous opioids release after acute inflammation
Chavarria Bolanos, Daniel ULg; Flores-Reyes, Hector; Pozos-Guillen, Amaury

Poster (2011, September 24)

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See detailMicrostructure characterisation of nanocomposite polymeric foams by X-ray microtomography
Plougonven, Erwan ULg; Marchot, Pierre ULg; Detrembleur, Christophe ULg et al

Poster (2011, September 21)

Recent advances in microstructured materials have given rise to many new types of composites that exhibit original and interesting physical properties. For example, a nanocomposite made of carbon ... [more ▼]

Recent advances in microstructured materials have given rise to many new types of composites that exhibit original and interesting physical properties. For example, a nanocomposite made of carbon nanotubes inside a polymer matrix shows exceptional electromagnetic interference shielding effectiveness when foamed. However, the effective properties of such materials strongly depend on the shape and topology of the microstructural cells. An accurate method for investigating the cellular microstructure is X-ray microtomography (XRµT), for it is non-destructive, and it provides 3D geometric information. Although it cannot be used to observe nanofiller dispersion, it has a strong potential for cell structure characterization. In order to reduce the need for trial and error for tailoring these materials, our objective is to characterize, using XRµT, two different types of foaming procedures, namely supercritical CO2 batch foaming and freeze drying. As the resolution is limited compared to cell size, we have developed a novel statistical method based on 3D autocorrelation to determine characteristic length and examine anisotropy. We present results for these two types of foams and show the limitations of this method. [less ▲]

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See detailBiocontrol proteomics:Implication of the pentoses phosphates pathway in the antagonist effect of Pichia anomala against Botrytis cinerea on apple
Kwasiborski, Anthony ULg; Renaut, Jenny; Lepoivre, Philippe ULg et al

Poster (2011, September 21)

The growing interest of the consumers for the wholesome food and the protection of the environment as well as the development of resistant pathogens to pesticides, stimulate the interest of growers to ... [more ▼]

The growing interest of the consumers for the wholesome food and the protection of the environment as well as the development of resistant pathogens to pesticides, stimulate the interest of growers to apply biological control methods. Pichia anomala strain K was previously identified as an efficient biocontrol agent of the main apple pathogens, Botrytis cinerea and Penicillum expansum. Further study demonstrated the complexicity of the mode of action of P. anomala against B. cinerea. A cDNA-AFLP and gene disruption study revealed implication of exo-β-1,3-glucanases in the mode of action of P. anomala strain Kh6 (a haploid form of P. anomala strain K displaying the same biocontrol properties). However, these studies suggested also implication of other factors. The present study aims to increase our knowledge of the mode of action of P. anomala strain Kh6 against B. cinerea using an in situ approach allowing the triple interaction, host/pathogen/antagonist and the proteomic tool allowing to study the ultime expression of the genome without a priori. One 50mm wound per apple were covered by a membrane and inoculated by a P. anomala suspension then by B. cinerea or not. Samples were collected during the exponential and stationary phase to identify the early and later responses to the presence of B. cinerea. After extraction, proteins were separated on 2-D gels. Spots influenced by the presence of B. cinerea in exponential and stationary phases were identified by MALDI-ToF. One hundred five and sixty spots of proteins were influenced by the presence of B. cinerea in exponential and stationary phases respectively. In exponential phase, P. anomala Kh6 in absence of B. cinerea uses mainly the glycolysis pathway, whereas in presence of pathogen, it orientates its energetic metabolism to the oxidative phosphorylation and sets up the pentose phosphate pathway. Thanks to this new orientation, P. anomala Kh6 probably obtains energy and nucleic acids allowing to colonize the wound as fast as in absence of B. cinerea and prevents the use of nutrients by the pathogen. In stationary phase, no differences in the P. anomala Kh6 energetic metabolism, in absence and in presence of B. cinerea were observed. During that phase, P. anomala Kh6 seems to use the alcoholic fermentation in order to face the nutrients impoverishment of the substrate. [less ▲]

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See detailDriven weak to strong pinning crossover in a partially nanopatterned superconductor
Shaw, Gorky ULg; Banerjee, S. S.; Tamegai, T. et al

Poster (2011, September 20)

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See detailA robustness study to investigate the performance of parametric and non-parametric tests used in Model-Based Multifactor Dimensionality Reduction Epistasis Detection.
Mahachie John, Jestinah ULg; Gusareva, Elena ULg; Van Lishout, François ULg et al

Poster (2011, September 19)

Model-Based Multifactor Dimensionality Reduction (MB-MDR) is data mining technique to identify gene-gene interactions among 1000nds of SNPs in a fast way, without making assumptions about the mode of ... [more ▼]

Model-Based Multifactor Dimensionality Reduction (MB-MDR) is data mining technique to identify gene-gene interactions among 1000nds of SNPs in a fast way, without making assumptions about the mode of genetic interactions. By construction, one of the implementations of MB-MDR involves testing one multi-locus genotype cell versus the remaining cells, hereby creating two imbalanced groups for trait distribution comparison. To date, for continuous traits, we have adopted a standard F-test to compare these groups. When normality assumption or homoscedasticity no longer hold, highly inflated results are to be expected. The power and type I error control of MB-MDR under these assumptions has been thoroughly investigated in Mahachie John et al [1]. The aim of this study is to assess, through simulations, the effects of ANOVA model violations on the performance of Model-Based Multifactor Dimensionality Reduction (MB-MDR). We quantify their effect on MB-MDR using default options, but at the same time introduce alternative options with increased performance. The better handling of imbalanced data using robust approaches [2] within a MB-MDR context is exemplified on real data for asthma-related phenotypes. 1. EJHG (2011), Early view 2. David Freedman, Statistical Models: Theory and Practice, Cambridge University Press (2000), ISBN 978-0521671057 [less ▲]

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See detailComparison Of Different Methods For Detecting Gene-Gene Interactions In Case-Control Data
Cattaert, Tom ULg; Rial Garcia, J. A.; Gusareva, Elena ULg et al

Poster (2011, September 19)

It is generally believed that epistasis makes an important contribution to the genetic architecture of complex disease, and numerous statistical and bioinformatics methods have been developed to detect it ... [more ▼]

It is generally believed that epistasis makes an important contribution to the genetic architecture of complex disease, and numerous statistical and bioinformatics methods have been developed to detect it. We compare several state-of-the-art epistasis detection methods in terms of empirical power, type-I error control, and CPU time. The methods compared include Model-Based Multifactor Dimensionality Reduction (MB-MDR) [1, 2], BOolean Operation-based Screening and Testing (BOOST) [3], EPIBLASTER [4], Random Jungle (RJ) [5], Logistic Regression and PLINK. Our comparative study is based on an extensive simulation study using different two-locus models, exhibiting both main effects and epistasis [3]. In these simulations, 100 SNPs are generated, no LD between them. All genotypes are assumed to be in Hardy-Weinberg equilibrium. Furthermore, 2 disease-associated SNPs are selected, with MAFs set to 0.1, 0.2 and 0.4. The MAFs of the non-disease associated SNPs are uniformly distributed on [0.05, 0.5]. In order to achieve high accuracy in empirical power estimation, all simulation settings involve 1000 replicates. All methods are applied to WTCCC Crohn's Disease data. [1] Calle, M.L. et al. (2008), Tech. Rep. No. 24, Dep. of Systems Biology, Univ. de Vic [2] Cattaert, T. et al. (2011), Ann. Hum. Gen. 75, 78-89 [3] Wan, X. et al. (2010), Am. J. Hum. Gen. 87, 325-340 [4] Kam-Thong, T. et al. (2011), Eur. J. Hum. Gen. 19, 465-471 [5] Schwartz, D.F. et al. (2010), Bioinf. 26, 1752-1758 [less ▲]

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See detailGenome-wide epistasis screening for Crohns’ disease
Gusareva, Elena ULg; Van Steen, Kristel ULg

Poster (2011, September 19)

Genome-wide association (GWA) studies of Crohn's disease have identified numerous genes. However, a substantial portion of the heritability of this disease remains unexplained. Some gene variants, not ... [more ▼]

Genome-wide association (GWA) studies of Crohn's disease have identified numerous genes. However, a substantial portion of the heritability of this disease remains unexplained. Some gene variants, not detectable via main effects GWA study, may manifest themselves only in interaction with other variants. To search for interacting genes involved in the regulation of Crohn's disease, we performed GWA epistasis screening in a large human cohort (1851 cases/2938 controls) belonging to the Wellcome Trust Case Control Consortium (WTCCC). All subjects were genotyped with the GeneChip 500K Mapping Array Set (Affymetrix chip). SNPs that passed our quality control (359,479 SNPs) were processed in Biofilter (a software package that looks for candidate epistatic genes contributing to disease risk) giving rise to 14,185 SNPs. Subsequent MB-MDR epistasis screening discovered four pairs of interacting SNPs on chromosome 4q35.1 and eight pairs on chromosome 11q23.2. The identified pairs of SNPs were confirmed with synergy-based measures. Notably, despite their mapping to the same genomic regions, the interacting SNPs were not in LD (r^2 < 0.5). Our findings support the idea of close chromosomal localization of two pairs of interacting genes that are involved in development of Crohn's disease. [less ▲]

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See detailParameter estimation using slug tests : application to a heat injection and storage experiment
Vandenbohede, Alexander; Louwyck, Andy; Daoudi, Moubarak et al

Poster (2011, September 19)

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See detailInsertional mutagenesis to select mutants for modified hydrogen photoproduction in Chlamydomonas reinhardtii
Godaux, Damien ULg; Emonds-alt, Barbara; Cardol, Pierre ULg et al

Poster (2011, September 18)

The unicellular green alga Chlamydomonas reinhardtii has evolved the ability to redirect electrons from the photosynthetic chain to drive hydrogen production via chloroplast oxygen-sensitive hydrogenases ... [more ▼]

The unicellular green alga Chlamydomonas reinhardtii has evolved the ability to redirect electrons from the photosynthetic chain to drive hydrogen production via chloroplast oxygen-sensitive hydrogenases. This process occurs under anaerobic conditions and provides a biological basis for solar-driven hydrogen production. Nevertheless, the yield is a major limitation for an economic viability and fundamental knowledge is still needed in order to have a better understanding of the process. In 2000, Melis and co-worker defined a protocol allowing a sustainable hydrogen production in sulfur deprivation condition. By adjustment of an existent protocol called the Winkler test, we are trying to isolate mutants with an attenuated photosynthesis to respiration capacity ratio (P/R ratio). This kind of mutants could be able to reach anoxia needed for hydrogenases activity without the stressful impact of sulfur deprivation. An insertional mutagenesis of Chlamydomonas has been carried out with an hygromycin resistance cassette and about 2500 transformants have generated and screened by the adapted Winkler test. We have isolated several oxygen-consuming mutants and the most promising one is subject to functional, molecular and genetic characterization. [less ▲]

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See detailInfluence of the processing parameters on the physicochemical properties of puff pastry margarines
Lefebure, Emilie ULg; Ronkart, Sébastien; Brostaux, Yves ULg et al

Poster (2011, September 18)

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See detailHow a topic treatment can worsen the situation: A new type of iatrogenic "burn".
REMY, Christophe ULg; LAUNGANI, Alexis; MAGNETTE, André ULg et al

Poster (2011, September 15)

Many studies showed the high frequency of cutaneous intolerances to ketoprofen but in 85 percent of them, these are photoallergies. The Belgian dematologists published an article a few years ago ... [more ▼]

Many studies showed the high frequency of cutaneous intolerances to ketoprofen but in 85 percent of them, these are photoallergies. The Belgian dematologists published an article a few years ago, demonstrating that it is important to avoid prescription of topical ketoprofen during sunny periods. Our experience showed the risks of lesions without exposing to UV radiations. These gels, on free sale, are widely used by the public. In physiotherapy, they are also regularly used by practitioners who rarely know the risk of photoallergies and often ignore the possibility of burn. In France, many questions have already been asked about these gels and they were even the object of a temporary withdrawal. [less ▲]

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See detailRapidly solidified microstructure of 3D parts fabricated by selective laser melting (SLM) - Examples of stainless steel 316L and titanium Ti-6Al-4V
Contrepois, Quentin ULg; Lecomte-Beckers, Jacqueline ULg

Poster (2011, September 12)

Laser additive manufacturing process capable of producing fully dense metallic parts direct from 3D CAD know a fast development. Major concerns are made to achieve the best accuracy of the final geometry ... [more ▼]

Laser additive manufacturing process capable of producing fully dense metallic parts direct from 3D CAD know a fast development. Major concerns are made to achieve the best accuracy of the final geometry and the reduction of the residual stresses but metallurgical aspects are also essential. The process can be described as a succession of very small welds. A key in the optimization of the mechanical properties is the understanding of the specific solidification mechanisms. Microstructures of two alloys were studied by metallographic examination and EBSD analysis. [less ▲]

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See detailDOES INCREASING LEVEL OF CONDENSED DISTILLERS SOLUBLES (PROTIWANZE®) SUPPLEMENTATION AFFECT MILK PRODUCTION IN DAIRY CATTLE ?
Lessire, Françoise ULg

Poster (2011, September 08)

INTRODUCTION The objective of this study was to evaluate whether introducing the condensed distillers solubles Protiwanze® (PW) at different concentrations in dairy cows diet induces changes in milk ... [more ▼]

INTRODUCTION The objective of this study was to evaluate whether introducing the condensed distillers solubles Protiwanze® (PW) at different concentrations in dairy cows diet induces changes in milk production. MATERIAL AND METHODS Three herds (72 Holstein and 25 Brown Swiss, DIM = 101 ± 57; daily milk production = 34.90 ± 8.40 L) received successively two RTM differing in PW content for 4 weeks, including a 7-day transition: 0% and 10% on a dry matter basis for Herd 1 and 10% and 15% for Herd 2 and 3. Both concentrations were distributed alternatively and repeated twice, each cow being its own control. Rations were formulated to meet energy and nitrogen requirements. During each testing period, animals were scored (Body Condition, Rumen Fill, Fecal Consistency, Undigested Fraction according to Zaaier (2001)) and their milk production and composition were measured by the Dairy Herd Improvement. RESULTS AND CONCLUSION Increasing the level of PW did not significantly change milk production in any Herd: Values were for Herd 1 at PW0%: 33.08 ± 0.76 L, at 10%: 31.66 ± 0.68 L, for Herd 2 at PW10%: 32.85 ± 0.93 L and at 15%: 32.37 ± 0.89, for Herd 3 at PW10%: 28.71 ± 1.21 L and at 15%: 31.80 ± 1.16. In Herd 1, milk urea decreased from 243.80 ± 4.55 mg/L for PW0% to 218.05 ± 4.03 mg/L for PW10%, (p<0.01), while fat percentage increased from 3.38% ± 0.09 (PW0%) to 3.77% ± 0.08 (PW10%) (p<0.01). Concerning scores, unconclusive changes were observed. Although increasing level of PW in dairy cows diet did not change milk production or composition, it is profitable since PW is 30-40% cheaper than other protein supplements like soya and canola meals. Moreover, it allowed to lower milk cost price by 1,5 eurocent per liter, when used at higher concentration. [less ▲]

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See detailEffect of steam explosion pre-treatment on enzymatic saccharification of lignocellulosic material
Meyer, Laurence ULg; Jacquet, Nicolas ULg; Vanderghem, Caroline ULg et al

Poster (2011, September 08)

Taking into account the sharp rise in prices and the depletion of resources of petroleum, an alternative to fossil resources is needed. A probable alternative is the use of lignocellulosic raw material to ... [more ▼]

Taking into account the sharp rise in prices and the depletion of resources of petroleum, an alternative to fossil resources is needed. A probable alternative is the use of lignocellulosic raw material to produce biofuels. The “first generation” biofuels are highly controversial because of the use of food plant material. The aim of the “second generation” biofuels is to take lignocellulosic non-food plant material as raw material. Lignocellulosic biomass has a very complex structure made of linkages between lignins, cellulose and hemicelluloses. The saccharification of these lignocellulosic materials requires the fractionation of its constituents. Research has lead to many lignocellulosic biomass fractionation pre-treatments. This study particularly focuses on the steam explosion pretreatment followed by an enzymatic saccharification. Steam explosion is a thermomechanical process which allows the breakdown of the lignocellulosic material structure by the combined action of steam heating, hydrolysis induced by the organic acids formed during the process and shear stress resulting from the pressure rough drop. This treatment leads to modification of the physical parameters such as water retention capacity, cristallinity rate of the cellulosic fraction, hydrolysis of the hemicellulosic fraction and rearrangement in the lignin structure. Such modifications are supposed to make cellulose enzymatic hydrolysis from complex lignocellulosic material easier. In order to verify this hypothesis, different lignocellulosic raw materials have been pre-treated by steam explosion. These materials were sugar beet pulp, corn straw and miscanthus. In order to check the effect of steam explosion pre-treatment on cellulose, a microcrystalline cellulose was also treated. Steam explosion was performed at a vapor pressure of 18 bars and with a retention time of 2 minutes. The steam exploded lignocellulosic materials and the untreated one were submitted to a hydrolysis with a mixture of enzymes composed of cellulases and cellobiase activities during 24 hours. The quantification of glucose in the hydrolysates at different times was performed by HPAEC-PAD. Rate of cellulose converted into glucose were better with steam exploded raw material showing that steam explosion allows improvement of lignocellulosic material for enzymatic saccharification. [less ▲]

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See detailDoes feeding dairy cattle with different levels of condensed distillers solubles (Protiwanze®) increase the risk of Sara?
Lessire, Françoise ULg; Rollin, Frédéric ULg

Poster (2011, September 08)

INTRODUCTION The objective of this study was to evaluate the effects of different levels of Protiwanze® (PW) supplementation, a highly acid (pH = 3.8 ± 0.8) and fermentescible CDS, on ruminal function of ... [more ▼]

INTRODUCTION The objective of this study was to evaluate the effects of different levels of Protiwanze® (PW) supplementation, a highly acid (pH = 3.8 ± 0.8) and fermentescible CDS, on ruminal function of dairy cows. MATERIAL AND METHODS PW supplementation was tested in 5 dairy herds (144 cows, DIM: 96 ± 61, daily milk production: 34.69 ± 8.22 L). In Herd 1, TMR was supplemented with 0% or 10% of PW on a dry matter basis for 4 weeks including a 7-day transition period. Each concentration was distributed twice during 2 periods alternatively with the other one, each cow being its own control. PW concentrations were 10 and 15% in Herd 2, 3 and 4. During every period, milk production was measured by the Dairy Herd Improvement and ruminal fluid sampled by a stomach tube (Ruminator®) on 5 cows. Samples were assessed for pH (portable pH meter), redox potential (Methylene blue test) and protozoa (optical microscopy). RESULTS AND CONCLUSION Ruminal pH values ranged between 5.94 and 7.74. Even when a correction factor of 0.5 was applied to take into account possible saliva contamination, only 8 pH samples pleaded for SARA although protozoa and methylene blue tests were within norms and cows clinically normal. No significant correlation between pH value, milk production and fat content could be demonstrated. Ruminal pH did neither significantly differ between the different levels of PW supplementation. In conclusion, in this study, PW could be used in dairy cows TMR at a level as high as 15% without increasing the risk of SARA. [less ▲]

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See detailMICRO-H2 – Microbiological production of hydrogen: study of microalgal and bacterial processes
Calusinska, Magdalena ULg; Joris, Bernard ULg; Wilmotte, Annick ULg et al

Poster (2011, September 07)

The project MICRO-H2 aims to study and exploit the microbial (bacterial and algal) production of hydrogen (H2). In addition to building a competence centre around the H2 production by microorganisms and ... [more ▼]

The project MICRO-H2 aims to study and exploit the microbial (bacterial and algal) production of hydrogen (H2). In addition to building a competence centre around the H2 production by microorganisms and the molecular monitoring of the processes, this project tries to address two main socio-economic issues. First, transport and many economic activities will be based on hydrogen energy in the near future. Secondly, many researches and technology developments deal with renewable resources. Therefore, a new integrated technology for a sustainable development should be promoted. Photofermentation and dark-fermentation are the most promising ways to produce biohydrogen. The main advantage of the first process is the complete conversion of substrate, if any, to hydrogen. However, present H2-production rates by microalgae remain low. Therefore, a better understanding of the microalgal hydrogen metabolism and rate improvements by genetic engineering are needed. On the other hand, dark-fermentation achieves at present far higher H2-production rates, but improvements are expected through monitoring and optimisation of bacterial diversity and activity. The objectives about bacterial H2 production were to increase knowledge, stability potentialities and investigation skills about the consortia of bacteria involved in bioreactors treating wastewater rich in carbohydrates to produce biohydrogen. The project focused mainly on the study of the potentialities of different consortia, with a focus on Clostridium strains. Concerning the microalgal production of H2, the objectives were to increase knowledge on the metabolic interactions that determine H2 evolution at the cellular level and to produce new strains with increased ability for H2 production in the two-stage process. [less ▲]

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See detailMastitis risk indicators assessed through a germ specific epidemiological model in southern Belgium
Theron, Léonard ULg; Sustronck, Bart; Bertozzi, Carlo et al

Poster (2011, September 07)

Bovine mastitis is the most prevalent pathology in dairy production; in order to identify herd related risk indicators, our study focused on germ-specific approach to refine known risk indicators between ... [more ▼]

Bovine mastitis is the most prevalent pathology in dairy production; in order to identify herd related risk indicators, our study focused on germ-specific approach to refine known risk indicators between environmental or contagious epidemiologic models. We gathered clinical mastitis during 3 months in 21 walloon dairy farms representing 1630 Holstein cows (mean: 67; SD: 18). Farmers were interrogated by a questionnaire about their main practices and basic mastitis knowledge questions. Quarters and severity were recorded, sampled for bacteriology at day 0 and day 21 during 3 months. Individual cell counts were also recorded. Risk analysis included Odds ratio calculation (OR) and multivariate regression. The average prevalence of mastitis on the study was 3.25% (min 0.3%, max : 11.2%, SD : 2.8%) which is coherent with previous epidemiological studies in Wallonia. 124 quarters were sampled and non-negative bacteriology shown 45% of strictly environmental pathogens, 22% of strictly contagious pathogens and 33% of mix epidemiological model pathogens. Overall risk assessment revealed that cubicles free-stall herds shown mastitis lower incidence (OR = 0.49; IC95 [0.34-0.72]). Surprisingly, post-dipping appeared as an overall positive risk indicator for mastitis prevalence (OR =2.13; IC95 [2,13-3,39]). The germ specific approach revealed that Post-dipping was present in low incidence herds with contagious models (OR=0.29; IC95 [0.12-0.71]) and that the type of pathogen model is an interaction in post-dipping risk analysis (Breslow-Day test p<0.0001), whereas housing had no interaction with the model (p=0.33). In this way of categorizing variables, one is able to identify overall risk indicators or germ-specific model. This can lead to more accurate advices in farm consulting. [less ▲]

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See detailA single synthetic small molecule that generates force against a load
Lussis, Perrine ULg; Svaldo-Lanero, Tiziana; Bertocco, Andrea et al

Poster (2011, September 06)

Biological molecular machines are able to rectify random thermal motions to generate directional force and carry out tasks on both the molecular and macroscopic length scales1. Although some artificial ... [more ▼]

Biological molecular machines are able to rectify random thermal motions to generate directional force and carry out tasks on both the molecular and macroscopic length scales1. Although some artificial nanomachines have been synthesized2-4 and used to collectively carry out mechanical tasks5-8, the direct measurement of the mechanical processes at the single molecule level has yet to be realized. We show that biased Brownian motion of the sub-molecular components in a hydrogen bonded [2]rotaxane9-a molecular ring threaded onto a molecular axle-can be harnessed to generate significant directional forces. We applied a mechanical load to the ring by atomic force microscopy (AFM) cantilever during single molecule pulling-relaxing cycle. Using fluctuation theorems, we were able to relate the measurements of the work done at the level of individual molecules to the free energy change measured previously by ensemble measurements. The results show that individual rotaxane molecules can generate directional forces of similar magnitude to biological machines, and extend the capabilities of AFM-based single molecule mechanics to the world of small molecules. 1. Schilva, M. (ed.) Molecular Motors (Wiley-VCH, Weinheim, 2003). 2. Kinbara, K. & Aida, T. Toward intelligent molecular machines : Directed motions of biological and artificial molecules and assemblies. Chem. Rev. 105, 1377-1400 (2005). 3. Kay, E. R., Liegh, D. A. & Zerbetto, F. Synthetic molecular motors and mechanical machines. Angew. Chem. Int. Ed. 46, 72-191 (2007). 4. Browne, W., Feringa, B. L. Making molecular machines work. Nature Nanotech. 1, 25-35 (2006). 5. Berna, J., Leigh, D. A., Lubomska, M., Mendoza, S. M., Pérez, E. M., Rudolf, P., Teobaldi, G. & Zerbetto, F. Macroscopic transport by synthetic molecular machines. Nature Mater. 4, 704-710 (2005). 6. Liu, Y., Flood, A. H., Bonvallet, P. A., Vignon, S. A., Northrop, B. H., Tseng, H.-R., Jeppesen, J. O., Huang, T. J., Brough, B., Baller, M., Magonov, S., Solares, S. D., Goddard, W. A., Ho, C.-M. & Stoddart, J. F. Linear artificial molecular muscles. J. Am. Chem. Soc. 127, 9745-9759 (2005) 7. Eelkema, R., Pollard, M. M., Vicario, J., Katsonis, N., Ramon, B. S., Bastiaansen, C. W. M., Broer, D. J. & Feringa, B. L. Molecular machines: Nanomotor rotates microscale objects. Nature 440, 163 (2006). 8. Muraoka, T., Kinbara, K., Aida, T. Mechanical twisting of a guest by a photoresponsive host. Nature 440, 512-515 (2006). 9. Kay, E. R. & Liegh, D. A. Hydrogen bond-assembled synthetic molecular motors and machines. Top. Curr. Chem. 262, 133-177 (2005). [less ▲]

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See detailPOLLEN DISPERSAL ABILITIES OF ALS TARGET-SITE RESISTANT BLACK-GRASS (ALOPECURUS MYOSUROIDES HUDS.)
Maréchal, Pierre-Yves ULg; Henriet, François; Vancutsem, Françoise ULg et al

Poster (2011, September 05)

Target-Site Resistant (TSR) black-grass individuals were introduced in a field, at different growing stages to be synchronised with autochthonous population. Patches of susceptible black-grass were ... [more ▼]

Target-Site Resistant (TSR) black-grass individuals were introduced in a field, at different growing stages to be synchronised with autochthonous population. Patches of susceptible black-grass were created by setting protective canvas on few areas (from 0,5 up to 32m²), during herbicide spraying and they were removed afterwards. Those patches were disposed along rays starting from the introduction point at distances from 2 to 128 meters. In those patches, local black-grass grew regularly and was able to receive some pollen from the resistant individuals, located in the centered emitting area. The herbicide field treatment (mesosulfuron+iodosulfuron : 15+3 g.a.i.ha-1) was efficient, confirming that the local population is susceptible to ALS inhibitors, was preceded by another herbicide treatment targeting only broad-leaves weeds, performed on the entire field, including patches, such as the rest of cultural practices such as fertilization, and fungicide and insecticide treatment. All seeds were harvested in each patches separately and tested in glasshouse. Seed samples were sprayed with sulfometuron, herbicide active ingredient known not to be affected by non-target site resistance, in a way to detect the percentage of resistant black-grass that can be engendered after the introduction of TSR individuals and to determine the distance resistant pollen can cover. DNA analyses were performed on surviving plants to confirm the presence of the mutation. [less ▲]

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See detailGlucose-responsive layer-by-layer microcapsules as self-regulated insulin delivery system
Alaimo, David ULg; Detrembleur, Christophe ULg; Auzély-Velty, Rachel et al

Poster (2011, September 03)

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See detailDisulfide bridges, new prospect in drug delivery systems?
Cajot, Sébastien ULg; Danhier, F.; Schol, Daureen ULg et al

Poster (2011, September 03)

Detailed reference viewed: 31 (6 ULg)
See detailSmart block copolymers for biomedical applications
Sibret, Pierre ULg; Schol, D; De Pauw-Gillet, Marie-Claire ULg et al

Poster (2011, September 03)

Stimuli-responsive polymers are polymers that respond with rapid changes to external stimuli such as pH, temperature, light or ionic strength. Responses to the stimuli may manifest themselves as changes ... [more ▼]

Stimuli-responsive polymers are polymers that respond with rapid changes to external stimuli such as pH, temperature, light or ionic strength. Responses to the stimuli may manifest themselves as changes in solubility, shape or surface characteristics. They can also lead to the fomation of micelles or a sol-gel transition. These materials are very intersesting for different biomedical applications such as drug delivery systems, tissue engineering or sensors. In this work, we focused on two separate systems: on the one hand, micelles and, on the other hand, iron oxide nanoparticles. These nanoparticles are generally synthesized in a one-step process by alkaline coprecipitation of iron (II) and iron (III) precursors in aqueous solutions (Massart process). However, iron oxide nanoparticle suspensions produced by Massart process are not stable enough in physiological conditions to be used as is. A stabiliser coating is needed to avoid aggregation and consequent precipitation of the colloids in body fluids. For this coating, the polymer blocks chosen are: the poly(ethylene oxide) (PEO), the poly(acrylic acid) (PAA) and the poly(N-isopropyl acrylamide) (PNIPAM). The high flexibility and hydrophilicity of PEO chains make it an outstanding candidate for confering stealthiness to micelles and nanoparticles in order to avoid their rapid removal from the body by the opsonization process. The PAA is the pH-responsive block and the anchoring block. The PNIPAM is the thermoresponsive block with a thermal transition close to 37°C (99°F). Triblock copolymer was synthesized by a Reversible Addition Fragmentation Transfer Polymerization (RAFT) process combining poly(acrylic acid) PAA, poly(N-isopropylacrylamide) and poly(ethylene oxide) or poly[acrylate methoxy poly(ethylene oxide)]. This triblock copolymer was used alone to form micelles and with iron oxide to make magnetic stabilized nanoparticles. The behaviour of micelles and coated nanoparticles was investigated in different conditions by a combination of dynamic light scattering (DLS), transmission electron microscopy (TEM) and zeta potential measurements. Moreover, PAA-b-PNIPAM-b-PAMPEO nanofibers were obtained using electrospinning technique. These nanofibers present interesting prospects in the field of biomaterials and biomedical applications as they mimic the extracellular matrix of the skin. [less ▲]

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See detailVoice Impact of a Prolonged Reading Task at Two Intensity Levels: Subjective Self-Ratings
Remacle, Angélique ULg; FINCK, Camille ULg; Roche, Anne et al

Poster (2011, September 01)

Objectives: The objectives of this study are to evaluate the impact on voice of both duration and intensity level of 2 hours of continuous oral reading, using subjective self-ratings. Methods: Fifty ... [more ▼]

Objectives: The objectives of this study are to evaluate the impact on voice of both duration and intensity level of 2 hours of continuous oral reading, using subjective self-ratings. Methods: Fifty normophonic women undergo two sessions of voice loading in which the required intensity level of voice varied: 60-65 dB(A) for the first session, and 70-75 dB(A) for the second session. Voice intensity level is constantly controlled with a Digital Sound Level Meter at a distance of 40cm from the mouth. Subjects’ voices are orally loaded by reading a novel of their choice for 2 hours in a quiet room (background level < 30dBA). The effects of loading are assessed with regard to self-ratings of voice obtained before and every 30 minutes during the loading tasks. The following parameters are evaluated using a 100-mm horizontal visual analogue scale: voice quality, phonation effort, vocal fatigue and laryngeal discomfort. A repeated-measure analysis of variance (ANOVA Duration X Intensity Level) where the subjects are used as their own controls is carried out to compare data obtained at different times of the reading sessions. Results and conclusion: There is a significant effect of the duration (p < 0.0001) for all the subjective self-ratings, but no differences between the two intensity levels of reading. Feeling of phonation effort, vocal fatigue and laryngeal discomfort significantly increase during prolonged reading, whereas self-rating of voice quality decrease. Subjects do not report more complaints in the 70-75 dB session than in the 60-65 dB one. To conclude, subjects’ self-ratings of voice significantly worsens throughout the reading task as a duration effect, but there is no intensity level effect. [less ▲]

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See detailAutomated synthesis of [18F] FBEM for labeling of thiol containing compounds
Paris, Jérôme ULg; Thonon, David ULg; Kaisin, Geoffroy ULg et al

Poster (2011, September 01)

[18F]FBEM, i.e. N-[2-(4-[18F]fluorobenzamido)ethyl]maleimide, is a useful synthon employed for the specific radiolabeling of thiol containing compounds, including peptides and proteins. The aim of the ... [more ▼]

[18F]FBEM, i.e. N-[2-(4-[18F]fluorobenzamido)ethyl]maleimide, is a useful synthon employed for the specific radiolabeling of thiol containing compounds, including peptides and proteins. The aim of the present work was to develop a fast, reproducible and fully automated synthesis of this compound in order to improve its availabilty as well as for obvious radioprotection matters. [less ▲]

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See detailEnhancement of in-situ Transformation of M2C Eutectics Carbides during High Temperature Heat Treatment on a HSS and a Semi-HSS Grades
Tchuindjang, Jérôme Tchoufack ULg; Sinnaeve, Mario; Lecomte-Beckers, Jacqueline ULg

Poster (2011, September)

Alloys of the complex system Fe-Si-C-Cr-C-X, where X is a strong carbide forming-element are well known to exhibit interesting mechanical properties, including wear and abrasion resistances. Such a ... [more ▼]

Alloys of the complex system Fe-Si-C-Cr-C-X, where X is a strong carbide forming-element are well known to exhibit interesting mechanical properties, including wear and abrasion resistances. Such a tribological behavior is mainly due to the presence of carbides especially those obtained during the solidification route and that are known as primary or eutectic carbides. It may therefore be interesting to determine the relative stability of primary carbides when considering thermal and thermomechanical treatments performed at a temperature high enough to allow either the homogenization of the matrix or the occurrence of a desired grain size. This thermal stage is often required to produce tailored microstructures that can lead to improved mechanical properties. In this work a series of thermal treatments performed on samples originated form casting foundry parts were done. Raw materials are both HSS and semi-HSS grades used in application where wear resistance is needed. Thermo- Calc® (TC) simulations and Differential Thermal Analysis (DTA) were performed to determine the crystallization behavior and the subsequent solid state transformations of the studied alloys respectively in equilibrium and in non equilibrium conditions. Light and Scanning Electron Microscopies were done together with hardness measurements in order to enhance metallurgical features of the heat treated samples. Image analysis yielded the determination of carbides volume fractions. It appears from microstructural analyses and carbides quantification that Mo-rich eutectic carbides undergo in situ phase transformations during heat treatments. In fact Mo-rich M2C carbides transform themselves into MC, M6C and M3C, through a so-called budding phenomenon. Such a phenomenon is the evidence of a preferential migration of some atoms that escape from the parent M2C carbide to diffuse further away from their initial site with increasing time and temperature. The stable or metastable nature of eutectic carbides is also discussed from DTA and TC results, as M2C carbides found in both as-conditions and DTA samples were not predicted by equilibrium conditions. [less ▲]

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See detailA method for evaluating weaknesses and critical steps in the Radiation Treatment Process through Precursor Events reporting
LENAERTS, Eric ULg; DELGAUDINE, Marie ULg; COUCKE, Philippe ULg

Poster (2011, September)

objectives: to establish a method based on the reporting of precursor events to detect and to assess weak steps in the Radiation Treatment process. These steps are categorized according to Work domains ... [more ▼]

objectives: to establish a method based on the reporting of precursor events to detect and to assess weak steps in the Radiation Treatment process. These steps are categorized according to Work domains, functional Basic Responsibilities and levels of Severity of precursor events [less ▲]

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See detailKinetics and diffusional limitations in nanostructured heterogeneous catalyst with controlled pore texture
Pirard, Sophie ULg; Hermans, Sophie; Devillers, Michel et al

Poster (2011, September)

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See detailOptimized deposition of photocatalytic TiO2 thin films produced by a non-aqueous sol-gel method
Malengreaux, Charline ULg; Timmermans, Adrien; Pirard, Sophie ULg et al

Poster (2011, September)

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See detailNEONATAL INVASIVE GROUP B STREPTOCOCCAL (GBS) INFECTIONS IN EUROPE
MELIN, Pierrette ULg; Berner, Reinhard; Afshar, Baharak et al

Poster (2011, September)

Objectives: To describe clinical characteristics and capsular type of GBS isolates responsible of invasive infections in infants from Belgium, Bulgaria, Czech-Republic, Denmark, Germany, Italy, Spain and ... [more ▼]

Objectives: To describe clinical characteristics and capsular type of GBS isolates responsible of invasive infections in infants from Belgium, Bulgaria, Czech-Republic, Denmark, Germany, Italy, Spain and United Kingdom, representing one of the main objectives of the DEVANI (DEsign of a Vaccine Against Neonatal Infections) project. Methods: Surveillance of invasive GBS infections in infants was performed from mid-2008 through December 2010. For each case, a standardized case report form was filled. Samples from cases were processed using local procedures. GBS isolates were characterised in national central labs using standardised type-specific (Ia, Ib-IX) latex agglutination and molecular typing methods. Results: Data on 188 infants with invasive infection were analysed: 144 (60.6%) early onset diseases (EOD) and 74 (39.4%) late onset diseases (LOD). In EOD, mean/median ages at onset were 14/0 hours and the male:female ratio was 1.25. The predominant manifestation at onset was respiratory distress (42% cases); 83% cases were associated with sepsis/bacteremia, 15% with pneumonia and 6% with meningitis. Late-prenatal screening cultures were obtained from 51% of cases’ mothers and only half of these were positive for GBS. Non-elective C-section, intrapartum fever and rupture of membrane (>18h) were more frequent in EO-cases’ mothers versus healthy babies’ GBS-positive mothers. The major serotypes were III (43%), V (21%) and Ia (18%). In LOD, mean/median ages at onset were 42/34 days and the male:female ratio was 0.9. The predominant characteristic at onset was fever (62% cases); 70% cases were associated with sepsis and 30% with meningitis. Very rare manifestations were osteomyelitis and cellulitis. Serotype III was highly predominant (80.6%) followed mainly by Ia (12.5%). Death rates were 4.7/1.5% in EOD/LOD. Conclusions: Clinical presentations were associated with age at onset of infection. Serotype III predominated in neonatal infections. Prenatal screening was not universal neither sensitive. Study funded through the European Commission Seventh Framework. [less ▲]

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See detailStructural and morphological Control of TiO2 nanoparticles by selective adsorption of organic molecules
Dufour, Fabien ULg; Durupthy, Olivier; Cassaignon, Sophie et al

Poster (2011, September)

Semiconducting nanocrystals with tailored shapes have been widely investigated in the past decades because of their many shape-dependant properties. Anatase, a metastable phase of the titanium dioxyde ... [more ▼]

Semiconducting nanocrystals with tailored shapes have been widely investigated in the past decades because of their many shape-dependant properties. Anatase, a metastable phase of the titanium dioxyde (TiO2), is one of the most interesting material in many applications, such as photocatalysis, photovoltaics, photo/electrochromics or sensors. [1] In addition to an influence of the nanoparticles size, recent works on the anatase phase demonstrated the effect of the expressed surfaces nature on the nanoparticles photoreactivity. [2] Sol-gel method has been used to obtain a wide range of anatase nanoparticles sizes and morphologies by the control of concentrations, ions in solution, solution acidity and aging parameters. [3] In order to avoid the brookite phase often obtained with the anatase phase, microwave heating was efficiently used. Furthermore, conventional heating method has been compared with hydrothermal and microwave activated synthesis. The precise morphological control has been achieved by selective adsorption of organic molecules during synthesis: different shapes of anatase nanoparticles have been synthesized. [4,5]. The influences of synthesis parameters and the organic molecules nature on the nanoparticles structure and morphology have been analysed with various techniques, such as XRD and HRTEM. [less ▲]

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