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See detailSynthesis of novel poly(N-vinyl amide)s containing copolymers by cobalt-mediated radical polymerization
Kermagoret, Anthony ULiege; Hurtgen, Marie ULiege; Liu, Ji ULiege et al

Poster (2012, May 10)

Poly(N-vinyl amide)s are found in many applications due to their valued properties including water solubility, biocompatibility, metal-coordination ability, etc. Although N-vinyl amides are easily ... [more ▼]

Poly(N-vinyl amide)s are found in many applications due to their valued properties including water solubility, biocompatibility, metal-coordination ability, etc. Although N-vinyl amides are easily polymerized via radical pathways, their growing radicals are quite reactive due to the lack of stabilizing group, rendering the synthesis of well-defined poly(N-vinyl amide)s challenging. Thus, we explored the organometallic-mediated radical polymerization (OMRP) of a series of N-vinyl amides using bis(acetylacetonato)cobalt(II) as controlling agent in order to develop a platform for the precision synthesis of poly(N-vinyl amide)s. [less ▲]

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See detailCrosslinking of star-shape PCLs through Diels-Alder reactions for the preparation of shape memory polymers
Defize, Thomas ULiege; Riva, Raphaël ULiege; Thomassin, Jean-Michel ULiege et al

Poster (2012, May 10)

Poly(ε-caprolactone) (PCL), a semi-crystalline polymer, is one of the most widely studied polymers for the development of shape memory materials when chemically cross-linked. PCL presents several ... [more ▼]

Poly(ε-caprolactone) (PCL), a semi-crystalline polymer, is one of the most widely studied polymers for the development of shape memory materials when chemically cross-linked. PCL presents several advantages such as a melting transition temperature close to human body temperature, a high biocompatibility and is (bio)degradable. So, this polymer is highly relevant for both biomedical devices such as stents or resorbable suture wires and also for degradable packaging. However, after cross-linking, the material can not be reprocessed, preventing any reuse/recycling of the material. One of the purposes of this work is to find a solution to this major drawback, which would then allow, for example, to reshape packaging films after use or to recycle trimmings remaining after fabrication. Amongst current trends in the design of new polymer and composite materials, the use of organic reactions that are able to create and reversibly disrupt chemical bonds upon an external stimulus (temperature, irradiation,…) is currently gaining more and more attention as it can lead to applications in various areas such as remendable materials, drug delivery systems, stimulus-degrading materials or recyclable materials. This contribution aims at reporting a new concept for the preparation of well defined and recyclable PCL based reversibly cross-linked shape memory polymer by the formation of reversible carbon-carbon bonds. Amongst all the reversible links described in the literature, thermally (4+2) reversible cycloadditions present interesting features such as the creation of robust bonds and well defined reversibility conditions. As an example, the application of furan/maleimide adducts as covalent link, which cycloreversion is largely favored in the range of temperature (90-120°C), is widely reported. For this purpose, commercially-available star-shaped PCL precursors have been selected and selectively modified at their chain ends either by a diene (furan, anthracene) or a dienophile (maleimide). Typically, PCL-based shape memory materials have been prepared by mixing a stoichiometric amount of diene-bearing and maleimide-bearing PCLs in a twin-screw mini-extruder at a temperature which favors cycloreversion. The polymer blend is then cured at 65°C (just above PCL melting temperature), with the purpose to increase chains mobility and improve the formation of the adducts. Cross-linked PCLs were obtained, as evidenced by swelling experiments. The shape memory properties of the materials have been studied by cyclic tensile thermomechanical analysis. The influence of the nature of the Diels-Alder moieties on the cross-linking rate and on the shape memory properties has been studied. Reversibility of the network formation in the case of furan, used as diene, has been assessed by rheology and by recycling experiment. [less ▲]

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See detailSubjective self-ratings through a prolonged reading task in dysphonic versus normophonic female teachers
Remacle, Angélique ULiege; Morsomme, Dominique ULiege; Berrué, Elise et al

Poster (2012, May 10)

Aim: The purpose of this study was to evaluate the impact that a 2-hour reading task could have on ones voice in 16 normophonic and 16 dysphonic female teachers. Method and material: Teachers’ voices were ... [more ▼]

Aim: The purpose of this study was to evaluate the impact that a 2-hour reading task could have on ones voice in 16 normophonic and 16 dysphonic female teachers. Method and material: Teachers’ voices were orally loaded by reading a novel. They were instructed to read for imaginary students, as in their classroom. Voice intensity was constantly controlled between 70 and 75 dB. Every 30 minutes, participants were asked to answer the following questions using a 100-mm horizontal visual analogue scale: 1) How is your voice quality? 2) Do you feel any phonation effort? 3) Do you feel any vocal fatigue? and 4) Do you feel any laryngeal discomfort? Results and conclusions: For all subjective self-ratings, the repeated measures ANOVA demonstrated significant main effects of the duration (p < 0.0001) and of the group (p < 0.05). Subjects of both groups reported a worsening of their voice quality during the reading while phonation effort, vocal fatigue and laryngeal discomfort increased. Surprisingly, no significant interaction between duration and group was found. This means that subjective self-ratings realized before and during the reading task depict a similar evolution of both groups, while we expected more worsening of voice through time in the dysphonic group. [less ▲]

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See detailGas migration in sea ice: from observations to modelling
Zhou, Jiayun ULiege; Moreau, Sébastien; Vancoppenolle, Martin et al

Poster (2012, May 07)

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See detailThe Lactoperoxidase System, a soft chemical method to control of potato late blight
Bafort, Françoise ULiege; Jijakli, Haissam ULiege; Perraudin, Jean-Paul

Poster (2012, May 07)

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See detailIn vitro hemocompatibility of nanocarriers tailored for biopharmaceutical drugs.
Sevrin, Chantal ULiege; Cerda Cristerna, Bernardino Isaac ULiege; Lombart, François ULiege et al

Poster (2012, May 06)

The optimization of nanoparticles (NP) for drug delivery, in particular to target the BBB, imposes to verify their hemocompatibility both for toxicological and efficiency of targeting perspectives. Indeed ... [more ▼]

The optimization of nanoparticles (NP) for drug delivery, in particular to target the BBB, imposes to verify their hemocompatibility both for toxicological and efficiency of targeting perspectives. Indeed the large surface they are able to expose to the biological environment promotes their interaction with various biochemicals, in particular proteins which can after adsorption elicit the activation of biological cascades either responsible from NP clearance or/and harmful body reaction (inflammatory / coagulation). In the frame of the European Integrated Project : “Nanobiopharmaceutics”, we have the opportunity to compare the hemoreactivity of about 145 different NP samples differing in core and surface chemistry and classified according to their expected difference in hydrophobicity based on the nature of their core materials. According to this classification, PLGA nanoparticles, polyglycidol-polyethyethylene oxide nanoparticles, polyglycidol thyolated or polyacrylamide nanogels, and polyelectrolyte complexes either based on polyamidoamine or poly(N,N-dimethylamino- 2-ethylmethacrylate) have been evaluated within a concentration ranging from 0.3 to 1000 μg/mL. These in vitro tests have been realized for screening purpose adopting normal human bloods and according to Iso 10993. As a summary of this extensive study, our results clearly highlight that most of the polymeric nanoparticles evaluated give rise to some alterations of the blood components. In particular the platelets, intrinsic pathway of coagulation and complement activation are the most reactive biological parameters in the presence of these nanostuctures. Although not strictly related to the surface chemistry our classification has also allowed us to derive some clear correlations between nanomaterial properties and their hemoreactivity. Within the class of polyelectrolyte electrolyte complexes, the modifications brought in the surface chemistry has drastically improved their hemoreactivity [less ▲]

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See detailNEURAL CORRELATES OF GAIT HYPOKINESIA IN PARKINSON'S DISEASE: AN FMRI STUDY
Cremers, Julien ULiege; Stamatakis, Julien; D'Ostilio, Kevin ULiege et al

Poster (2012, May 05)

Introduction: Brisk walking (BW) is an efficient tool to study gait hypokinesia whose pathogenesis remains poorly understood in Parkinson's disease (PD). Aims: Assuming that brain regions recruited during ... [more ▼]

Introduction: Brisk walking (BW) is an efficient tool to study gait hypokinesia whose pathogenesis remains poorly understood in Parkinson's disease (PD). Aims: Assuming that brain regions recruited during imagined gait strongly overlap with those recruited during real gait, we used mental imagery of BW as a paradigm to study the neural correlates of gait hypokinesia in PD with BOLD fMRI. Methods: 15 'on-drugs' PD patients and 15 controls matched for age and gender were instructed to imagine themselves in two situations: comfortable walking (CW) and BW on a 25 meter-path. Imagined speed reserve (ISR), defined as the difference between imagined BW and CW speeds, was measured as a control of behavioral performance. The first-level individual contrast images representing the comparison between BW and CW were entered into second-level analyses with the corresponding ISRs as correlation regressors. Results: ISRs and their real counterparts measured offline were significantly decreased in patients relatively to controls. They strongly positively correlated in patients (Pearson's r = 0.88) and controls (Pearson's r = 0.59). Between-group comparison of individual contrasts BW minus CW in correlation with their corresponding ISRs showed that increasing imagined gait speed was strongly associated with increased activity of the left posterior parietal cortex (PPC) in controls and with decreased activity of this region in the patients. Conclusions: Our findings suggest that gait hypokinesia is related to an impaired function of the left PPC in PD. The left PPC may represent a target for therapeutic interventions aimed at alleviating gait disturbances in PD. [less ▲]

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See detailMolecular biomimetics applied to medical devices
Van de Weerdt, Cécile ULiege; Archembeau, Catherine; Vreuls, Christelle ULiege et al

Poster (2012, May 05)

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See detailValidation of Adult Bone Marrow Stromal Cells in Cellular Therapy Protocols, using a Mouse Model for Parkinson’s Disease
Neirinckx, Virginie ULiege; Laudet, Emerence; Rogister, Bernard ULiege et al

Poster (2012, May 04)

Parkinson’s disease (PD) is the second most common neurodegenerative disorder in industrialized countries. Its main characteristic relies in a progressive loss of dopaminergic (DA) neurons in the ... [more ▼]

Parkinson’s disease (PD) is the second most common neurodegenerative disorder in industrialized countries. Its main characteristic relies in a progressive loss of dopaminergic (DA) neurons in the Substantia Nigra pars compacta (SNpc), resulting in a deficient dopamine release in the striatum and then promoting important defects in motility regulation. Unfortunately, motor symptoms are generally diagnosed once 80% of nigrostriatal neurons are already lost. The emergence of neuroprotective/-restorative strategies is then increasingly raising hope, and a lot of people now focus on cell therapy experiments. Adult bone marrow stromal stem cells (BMSCs) have already been demonstrated as ideal candidates for cell therapy in nervous lesions, regarding their high multipotency and the fact they can be easily harvested in the patient himself. After it has been demonstrated that some BMSCs arise from the embryonic neural crest (NC), we compared NC-BMSCs and mesenchymal (M)-BMSCs in vitro, in terms of differenciation abilities and more particularly in terms of neural fate. We then wanted to investigate and compare the potential usefulness of both populations in the context of a neurological pathology. We have validated a MPTP mouse model, mimicking the specific loss of nigral neurons, and started setting up a cell therapy experiment using stereotaxic brain injection of the two types of BMSCs. The survival rate of grafted cells was analyzed as well as their migration or differentiation, and their ability to restore neuronal loss was also observed. Our first results showed that once grafted inside the brain of MPTP mice, NC-BMSCs survive for about a week, staying tightly close to each other the injection track with no visible sign of migration. Afterwards, cells begin to disappear and we only observe a mean survival rate of 1% after 28 days. Looking at the nigrostriatal pathway integrity, neural crest-BMSCs don’t seem to induce any improvement: they don’t differenciate into neural cells, neither replace lost DA cells, and they do not induce any sprouting of surviving DA neurons. While the M-BMSCs graft experiment has to be completed, these first results showed that NC-BMSCs at the stem cell state are not able to restore the lesioned system, and maybe a pre-differenciation step would be required to trigger those cells into a neuronal fate before grafting them in a MPTP-mouse brain. [less ▲]

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See detailEvidence for a partial epithelial-mesenchymal transition in postnatal stages of rat auditory organ morphogenesis
Johnen, Nicolas ULiege; Cloes, Marie ULiege; Thelen, Nicolas ULiege et al

Poster (2012, May 04)

An epithelial-mesenchymal transition is a biological process that allows a polarized epithelial cell to undergo multiple biochemical changes that enable it to assume a mesenchymal cell phenotype. During ... [more ▼]

An epithelial-mesenchymal transition is a biological process that allows a polarized epithelial cell to undergo multiple biochemical changes that enable it to assume a mesenchymal cell phenotype. During this process, epithelial cells loosen cell-cell adhesion, module their polarity and rearrange their cytoskeleton: intermediate filaments typically switch from cytokeratin to vimentin. They also enhance their motility capacity. The epithelial-mesenchymal transition plays key roles in the formation of the body plan and in the differentiation of multiple tissues and organs but it is also involved in tissue repair, tissue homeostasis, fibrosis, and carcinoma progression. Until now, epithelial-mesenchymal transition has been rarely mentioned in the inner ear organogenesis. In chick, epithelial-mesenchymal transition has been reported as a possible mechanism of semicircular canal morphogenesis. More recently, an in vitro study has also indicated that sensory epithelial cells from mouse utricle can undergo an epithelial-mesenchymal transition to become cells expressing features of prosensory cells. By contrast, epithelial-mesenchymal transition has never been observed during auditory organ morphogenesis. The auditory organ, the organ of Corti, is a highly specialized structure composed by specific cellular types. The sensory cells are characterized by stereocilia at their apex and are necessary for the sound perception. Theses cells are supported by supporting cells. Based on their morphology and physiology, at least four types of supporting cells can be identified in the organ of Corti: inner and outer pillar cells, phalangeal cell and Deiter’s cells. The inner pillar cells and outer pillar cells combine to form the tunnel of Corti, a fluid filled triangular space that separates the single row of inner hair cells from the first row of outer hair cells. The Nuel spaces are another interval in the organ of Corti that is situated between the outer pillar cells and the different rows of outer hair cells and Deiters cells. To determine whether an epithelial-mesenchymal transition may play a role in the morphogenesis of the auditory organ, we studied the spatial localization of several epithelial-mesenchymal transition markers, the cell-cell adhesion molecules and intermediate filament cytoskeletal proteins, in epithelium of the dorsal cochlea during development of the rat organ of Corti from 18th embryonic day until 25th postnatal day. We examined by confocal microscopy immunolabelings on cryosections of whole cochleae with antibodies anti-cytokeratins as well as with antibodies anti-vimentin, anti-E-cadherin and anti-beta-catenin.Our results showed a partial loss of E-cadherin and beta-catenin between supporting cells at P8 and P12, respectively, and a temporary appearance of vimentin in pillar cells and Deiters between P8 and P10. Our results show a local loss of adhesion between supporting cells of the OC from P8, an increase expression of cytokeratins in supporting cells around P10 and a temporary appearance of vimentin in supporting cells at P8-10. These observations suggest that a partial epithelial-mesenchymal transition might be involved in the remodeling of the Corti organ during the postnatal stages of development in rat. [less ▲]

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See detailGlobal analysis of gene expression in the skin of mice after a 92 days journey in microgravity.
Neutelings, Thibaut ULiege; Liu, Y.; Cancedda, R. et al

Poster (2012, May 04)

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

Poster (2012, May 04)

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See detailUnravelling the roles of lysine acetylation by Elp3 during inner ear development
Mateo Sanchez, Susana ULiege; Delacroix, Laurence ULiege; Laguesse, Sophie ULiege et al

Poster (2012, May 04)

The inner ear is composed of a vestibular part that controls balance, and the cochlea, which is dedicated to hearing. In both parts of the inner ear, sensory epithelia comprise supporting cells ... [more ▼]

The inner ear is composed of a vestibular part that controls balance, and the cochlea, which is dedicated to hearing. In both parts of the inner ear, sensory epithelia comprise supporting cells surrounding the sensory hair cells. These cells bear at their apical surface a staircase-structured hair bundle, consisting of multiple rows of actin-based stereocilia and a single tubulin-based kinocilium. This hair bundle allows the transduction from mechanical stimuli, initiated by sound or gravitational changes, to electrical signals that will then be transmitted by neurons from the spiral ganglion (innervating hair cells of the cochlea) or the vestibular ganglion. The inner ear organogenesis requires a tightly regulated transcriptional program that can be affected by post-transcriptional and post-translational modifications among which lysine acetylation. Given the importance of acetylation homeostasis in controlling developmental processes, we planned to investigate its role in inner ear formation and focused our attention on Elp3 acetyl-transferase, a member of the Elongator complex recently implicated in neurogenesis. First, we have analysed Elp3 expression by in situ hybridization on wild type mice at different developmental stages (from E11.5 until P6) and showed that it was expressed in the entire early otocyst at E11.5 and persisted later in the sensory epithelium of the cochlea (the organ of Corti), in the stria vascularis and in the vestibule. To study the functional consequences of protein acetylation by the Elongator complex in the inner ear, we studied conditional knock-out mice (Elp3 cKO) in which Elp3 is depleted from the otic vesicle at E8.5. These mice, at stage P15, showed obvious balance dysfunction that was confirmed by a complete battery of behavioural tests: stereotyped circling ambulation, head bobbing, retropulsion, and absence of reaching response in the tail-hanging test. Unfortunately, the Elp3 cKO mice die before the onset of hearing, thus precluding any evaluation of hearing disorders. Balance defects in mice depleted for Elp3 is not due to vestibular structural abnormalities, since paint-filling experiments showed a normal inner ear anatomy compared to wild type mice. Moreover, immunostainings in the vestibule and in the organ of Corti indicated that cell patterning was not impaired in the absence of Elp3 since specialised cells are present and correctly organised at embryonic day E18.5 and later on. However, we were able to detect some defaults in hair cell bundle integrity and orientation in the auditory portion of inner ear from Elp3 cKO mice. We were also able to demonstrate an increased level of apoptosis in the Elp3 cKO spiral ganglion at E14.5 leading to a reduced number of fibers innervating the cochlear hair cells at P0 and P15. In conclusion, we have confirmed the expression of Elp3 in the inner ear and pointed out a role for this acetyl-transferase in balance function. Our results clearly show the implication of Elp3 in ciliogenesis, hair cell innervation and neuronal survival and we plan to go deeper in the mechanisms involved through the identification of the proteins acetylated by Elp3. [less ▲]

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See detailThe DBIRD complex: linking mRNA transcription to alternative splicing
Close, Pierre ULiege; East, P; Svejstrup, J

Poster (2012, May 04)

Detailed reference viewed: 16 (2 ULiège)
See detailDynamic and region specific changes in estrogen production induced by reproductive stimuli.
de Bournonville, Catherine ULiege; Dickens, Molly J; Ball, Gregory F et al

Poster (2012, May 04)

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See detailApplication of molecular imaging in combination with quantitative proteomic approaches to determine the molecular players of adaptation to anti-angiogenic therapy in breast cancer.
Cimino, Jonathan ULiege; Sounni, Nor Eddine ULiege; Calligaris, David ULiege et al

Poster (2012, May 04)

The recognition of the “angiogenic switch” as a rate-limiting secondary step in tumorigenesis led to extensive pre-clinical researches on angiogenesis and finally the approval of VEGF-neutralizing ... [more ▼]

The recognition of the “angiogenic switch” as a rate-limiting secondary step in tumorigenesis led to extensive pre-clinical researches on angiogenesis and finally the approval of VEGF-neutralizing antibodies (bevacizumab) and VEGF receptor tyrosine kinase inhibitors (RTKs:Sunitinib). The Sunitinib has been used clinically in patients with breast cancer refractory to other therapeutic agents. Unfortunately, like the cytotoxic therapies, these drugs do not produce lasting effects and resistance to treatment appeared clinically. Questions have emerged about the failure of anti-angiogenic therapy in clinic and the limitations of predictive preclinical models, and also about the molecular assessment of all stages of tumor adaptation and metastatic disease. To this end, we applied a quantitative proteomics and imaging mass spectrometry tools to visualize and study the profiles of proteins and small molecules associated with tumor treated or not with Sunitinib using a novel preclinical model of breast carcinoma cells. [less ▲]

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See detailSequential T2 Relaxometry as a Non-Invasive Assessment of Transmural Inflammation in a Murine Model of Chronically Relapsing Colitis
Breynaert, C; Dresselaers, T; Cremer, J et al

Poster (2012, May)

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See detailModification de la gestion du dialogue intérieur des sportifs de haut niveau. Etude préliminaire
Lacrosse, Zoé; Godin, Philippe; Cloes, Marc ULiege

Poster (2012, May)

Le dialogue intérieur est constitué de pensées qui sont généralement spontanées mais qui peuvent également être sous le contrôle direct du sportif. Selon Hatzigeorgiadis, Zourbanos, Galanis et Theodorakis ... [more ▼]

Le dialogue intérieur est constitué de pensées qui sont généralement spontanées mais qui peuvent également être sous le contrôle direct du sportif. Selon Hatzigeorgiadis, Zourbanos, Galanis et Theodorakis (2011), le discours peut revêtir une orientation pédagogique ou motivante. Ces auteurs ont montré que les pensées motivantes sont plus efficaces pour améliorer la performance dans des situations nécessitant un effort de longue durée ou de la force. Par contre, le discours pédagogique est plus utile pour les tâches qui demandent du temps et/ou de la précision. Les pensées spontanées des sportifs sont à 80% négatives. Il est donc logique de tenter de modifier cette situation afin d’augmenter la part des pensées opérationnelles (objectif clair, énoncé bref et simple phonétiquement, initiation d’un acte ou un geste concret, stimulation). Dans cette étude, nous testons une approche visant justement à amener des sportifs à mieux exploiter leur dialogue intérieur. Notre étude porte sur 5 joueuses de volley-ball de 2ème nationale belge (postes de jeu différents) provenant de deux équipes, toutes volontaires. Nous avons filmé une première confrontation entre ces deux formations. Sur base de l’enregistrement vidéo, nous avons effectué des entretiens stimulés individuels ciblant divers événements survenus lors de la rencontre. Ces retours sur la pratique nous ont permis d’identifier les pensées des joueuses. Par la suite, chacune de celles-ci a participé à deux séminaires individuels qui avaient pour objectif de modifier les pensées négatives et positives en pensées opérationnelles. A l’issue du match retour, nous avons répété une séance de rappel stimulé et avons complété la collecte des données par un débriefing général. Parmi les résultats que nous avons déjà mis en évidence, nous retiendrons que le discours pédagogique s’avère particulièrement pauvre par rapport au discours motivant. Des implications pratiques sont proposées. [less ▲]

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See detailThe Prevalence of Event Clusters in Episodic Future Thoughts
Demblon, Julie ULiege; D'Argembeau, Arnaud ULiege

Poster (2012, May)

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See detailChemical control of Haplodiplosis marginata (Diptera: Cecidomyiidae)
Censier, Florence ULiege; Chavalle, Sandrine ULiege; Wittouck, Daniël et al

Poster (2012, May)

The saddle gall midge, Haplodiplosis marginata (von Roser), is a European pest of cereals. The larvae overwinter into the soil. Emergence of adult midges occurred during the spring and after mating ... [more ▼]

The saddle gall midge, Haplodiplosis marginata (von Roser), is a European pest of cereals. The larvae overwinter into the soil. Emergence of adult midges occurred during the spring and after mating, females lay their eggs on the leaves of cereals and several grasses. Eggs hatch a few days later; young larvae crawl to the stem and introduce themselves between the leaf sheath and the stem, were the larvae develop. As reaction of the presence of midge larvae, stem produce a longitudinal depression of 6-7 mm ended by two ridges looking as a horse saddle. When galls are numerous, they can cause break of stems and important yield losses. The saddle gall midge, which is a major pest in Central Europe, is not very well known in the Western part of the continent. It had already caused huge damage during outbreak periods. The last one reported in Belgium and in The Netherlands occurred between 1965 and 1970. Later, it was never reported again until 2010, where large populations and severe damage were observed, especially in the Flemish polders, a region with clay soils where wheat is cropped intensively. Faced with the resurgence of this pest, we sought to develop effective curative control. To date, crops chemical protection seems to be the only solution in case of heavy emergences. Experimentation was conducted in a highly infested field (Meetkerke, Belgian Polders), according to a randomized complete block arrangement with four replications. Foremost, a lambdacyhalothrin-based insecticide was used to evaluate efficiency of several protection schemes, ranging between one and four spray(s). The large spread of flights observed during the 2011 spring allowed to highlight the effect of treatment date on the attack intensity and also on the galls distribution along the stem, on the different internodes. Moreover, several insecticides already registrated in cereals against aphids were compared for their efficacy against saddle gall midge. Studied pyrethroids have shown a very good efficacy, ranging between 75 % and 87 %, when applied twice with a 2 weeks interval. To be efficient, chemical spray must be synchronized with the flights and egg laying periods. Monitoring the phenology of flights is thus essential as part of integrated pest management against saddle gall midge. [less ▲]

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See detailProfiling the smell of death by TD-GCxGC-TOFMS
Stefanuto, Pierre-Hugues ULiege; Stadler, S; Forbes, S et al

Poster (2012, May)

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See detailReference visualization and download analysis of the “geographical literature” in the Open Repository of ULg (ORBi)
Stirbu, Simona ULiege; Thirion, Paul ULiege; Schmitz, Serge ULiege et al

Poster (2012, May)

Set up by the University of Liège, ORBi (Open Repository and Bibliography) knew a lightning increase of the online posted references since its creation in 2008. The official launch took place on November ... [more ▼]

Set up by the University of Liège, ORBi (Open Repository and Bibliography) knew a lightning increase of the online posted references since its creation in 2008. The official launch took place on November 26th, 2008 and after considerable efforts on behalf of the team which manages the tool, and researchers who introduce themselves their publications, the contents of the repository managed to reach a value of 64245 references among which 38670 with full text. Working for the Library of Geography of the University of Liege, I found interesting to analyze the number of visualizations and downloads of the references (2005 to 2007) posted online by the ULg geographer’s, and the population interested in this literature. The highlight is on WHO and WHERE are the internet users visualizing and downloading ORBi references from? In order to detect the population using this scientific literature, we analyzed the user IP and their distribution in the world. The data was obtained from a MaxMind database. The type of population using this scientific literature: researchers, individuals, public or private companies was also determined. [less ▲]

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See detailCross-reactivity of 25-hydroxyvitamin D2 in ADVIA Centaur Total Vitamin D
FORTUNATO, Antonio; LE GOFF, Caroline ULiege; PEETERS, Stéphanie ULiege et al

Poster (2012, May)

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See detailThe own-age bias in age estimation of voices
Beaufort, Aline ULiege; Moyse, Evelyne ULiege; Brédart, Serge ULiege

Poster (2012, May)

Recently, it has been evidenced that age estimation performance may be influenced by an own-age bias, i.e. we can estimate more accurately the age of one’s own-age people than the age of other age people ... [more ▼]

Recently, it has been evidenced that age estimation performance may be influenced by an own-age bias, i.e. we can estimate more accurately the age of one’s own-age people than the age of other age people (George & Hole, 1995). To the best of our knowledge, all the studies that investigated the own-age bias used faces as stimuli. However, there are situations in which the voice is the only information available in order to estimate a person’s age (Cerrato et al., 2000). In the present study, the occurrence of an own-age bias in age estimation from voices was assessed by using an experimental design in which the age of participants (young vs old people) and the age of face stimuli (young vs old people) are crossed. Although we did not observe a crossed interaction where each age group would have been more accurate for in-group estimation than for out-group estimation, present results revealed the occurrence of an own-age bias in age estimation in younger adults only. Indeed young participants made smaller absolute errors than older participants when estimating the age of young voices. However, there was no significant difference between age groups when the age of older voices was estimated. [less ▲]

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See detailUn environnement d'apprentissage en ligne pour aider les futur(e)s logopèdes/orthophonistes à travailler la langue française
Jacquet, Maud ULiege; Maes, Estelle ULiege; Maillart, Christelle ULiege et al

Poster (2012, May)

Cette communication présente un dispositif qui propose un environnement en ligne pour aider les étudiants de logopédie à piloter leur trajectoire de formation afin d'avancer de façon autonome vers la ... [more ▼]

Cette communication présente un dispositif qui propose un environnement en ligne pour aider les étudiants de logopédie à piloter leur trajectoire de formation afin d'avancer de façon autonome vers la maîtrise de la langue française. Elle en explique les modalités, les résultats et les régulations par ailleurs pour la plupart déjà réalisées. [less ▲]

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See detailNumerical simulations of torsional flutter oscillations of a bluff body: Energy issues, GraSMech poster session
Andrianne, Thomas ULiege; Dimitriadis, Grigorios ULiege

Poster (2012, May)

The possibility of harvesting energy from aeroelastic phenomena is assessed through numerical simulations. The unsteady aerodynamics around an aeroelastic structure are modeled using the Discrete Vortex ... [more ▼]

The possibility of harvesting energy from aeroelastic phenomena is assessed through numerical simulations. The unsteady aerodynamics around an aeroelastic structure are modeled using the Discrete Vortex Method (DVM). The Torsional Flutter oscillations of a rectangular cylinder are studied in this work. The phenomenon is characterized by Limit Cycle Oscillations (LCOs) around the pitch axis of the rectangle. The complete bifurcation behaviour is investigated numerically and compared to wind tunnel measurements for validation. The energy issues are investigated in terms of the sensibility of the energy output to variations in the structural damping. [less ▲]

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See detailRooting the flowering process
D'Aloia, Maria ULiege; Bouché, Frédéric ULiege; Tamseddak, Karim et al

Poster (2012, May)

Detailed reference viewed: 33 (9 ULiège)
Peer Reviewed
See detailImpact of early versus late acquired blindness on the fuctional organization and connectivity of the occipital cortex
Collignon, O; Phillips, C; Dormal, G et al

Poster (2012, May)

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See detailAging affects the impact of light on non-visual congnitive brain responses but not pupillary constriction
Daneault, V; Vandewalle, Gilles ULiege; Hébert, M et al

Poster (2012, May)

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See detailRepeated cycles of DSS inducing a chronically relapsing inflammation: a novel model to study fibrosis using in vivo MRI T2 relaxometry
Breynaert, C; Dresselaers, T; Cremer, J et al

Poster (2012, May)

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See detailEscapement Success And Patterns Of Downstream Migration Of Female Silver Eel Anguilla Anguilla In The River Meuse
Verbiest, Hilde; Breukelaar, André; Ovidio, Michaël ULiege et al

Poster (2012, May)

Downstream migration of female silver eel Anguilla anguilla (L.) was studied by remote telemetry in the lower part of the River Meuse (Belgium and The Netherlands) using a combination of 9 detection ... [more ▼]

Downstream migration of female silver eel Anguilla anguilla (L.) was studied by remote telemetry in the lower part of the River Meuse (Belgium and The Netherlands) using a combination of 9 detection stations and manual tracking. N=31 eels (LT 64-90cm) were implanted with active transponders and released in 2007 into the River Berwijn, a small Belgian tributary of the River Meuse, 326 km from the North Sea. From August 2007 till April 2008 13 eels (42%) started their downstream migration and were detected at two or more stations. Mean migration speed was 0.62 m.s-1 (or 53 km.day-1). Only two eels (15%) arrived at the North Sea, the others being held up or killed at hydroelectric power stations, caught by fishermen or by predators or stopped their migration and settled in the river delta. A majority (58%) of the eels classified as potential migrants did not start their migration and settled in the River Berwijn or upper Meuse as verified by additional manual tracking. [less ▲]

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See detailSituation épidémiologique du virus de l’hépatite E chez le sanglier (Sus scrofa) en Belgique
Thiry, Damien ULiege; Mauroy, Axel ULiege; Brochier, Bernard et al

Poster (2012, May)

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Peer Reviewed
See detailTerqa Ceramic Culture during the 3rd Millennium BC. Material from 18th-26th Excavation Campaigns
Mas, Juliette ULiege

Poster (2012, May)

Terqa, an important Syrian Bronze Age site located in the Lower Middle-Euphrates region, benefited from a key position which provided the settlement with the opportunity to gain from exchanges and ... [more ▼]

Terqa, an important Syrian Bronze Age site located in the Lower Middle-Euphrates region, benefited from a key position which provided the settlement with the opportunity to gain from exchanges and innovations arriving from both the North and South, while developing its own identity and culture. A new study on pottery has just been carried out on 3rd-millennium material from eight excavation seasons. The recovered material has been used to specify Terqa’s chronostratigraphy with greater accuracy, comparing it with the neighboring site of Mari and other contemporary ones but also providing us with a preliminary overview of Terqa’s ceramic culture during the Early Bronze Age. [less ▲]

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See detailUse of Near Infrared and Raman spectroscopy for the optimization of API layer of pharmaceutical tablet
Chavez, Pierre-François ULiege; Mantanus, Jérôme; Cuypers, Serge et al

Poster (2012, May)

Detailed reference viewed: 73 (20 ULiège)
See detailFluxes of dimethylsulfide from warming sea ice
Carnat, Gauthier; Zhou, Jiayun; Papakyriakou, Tim et al

Poster (2012, May)

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See detailRelative impacts of climate and landuse changes on future flood damage along River Meuse in Wallonia
Beckers, Arnaud ULiege; Detrembleur, Sylvain ULiege; Dewals, Benjamin ULiege et al

Poster (2012, April 27)

Climate change is expected to increase flood hazard across most of Europe, both in terms of peak discharge intensity and frequency. Consequently, managing flood risk will remain an issue of primary ... [more ▼]

Climate change is expected to increase flood hazard across most of Europe, both in terms of peak discharge intensity and frequency. Consequently, managing flood risk will remain an issue of primary importance for decades to come. Flood risk depends on territories’ flood hazard and vulnerability. Beside climate change, land use evolution is thus a key influencing factor on flood risk. The aim of this research is to quantify the relative influence of climate and land use changes on flood damage evolution during the 21st century. The study focuses on River Meuse in Wallonia for a 100-year flood. A scenario-based approach was used to model land use evolution. Nine urbanization scenarios for 2100 were developed: three of them assume a “current tend” land use evolution, characterized by urban sprawl, while six others assume a sustainable spatial planning, leading to an increase in density of residential areas as well as an increase in urban functions diversity. A study commissioned by the EU has estimated a 30 % increase in the 100-year discharge for River Meuse by the year 2100. Inundation modeling was conducted for the present day 100-year flood (HQ100) and for a discharge HQ100 + 30%, using the model Wolf 2D and a 5m grid resolution Digital Elevation Model (Ernst et al. 2009). Based on five different damage curves related to land use categories, the relative damage was deduced from the computed inundation maps. Finally, specific prices were associated to each land use category and allowed assessing absolute damages, which were subsequently aggregated to obtain a damage value for each of the 19 municipalities crossed by River Meuse. Results show that flood damage is estimated to increase by 540 to 630 % between 2009 and 2100, reaching 2.1 to 2.4 billion Euros in 2100. These increases mainly involve municipalities downstream of a point where the floodplain width becomes significantly larger. The city of Liège, which is protected against a 100-year flood in the present situation, would undergo about 450 million Euros damage for a 100-year flood in the 2100, i.e. in-between 21% and 25 % of the whole damage increase. The influence of climate is three to eight times higher than the effect of land use change according to the land use evolution scenarios considered. Nevertheless, these two factors have a comparable influence on seven municipalities. Consequently, although a careful spatial planning would not considerably reduce the overall flood damage at the level of theWalloon part of the Meuse Valley, more sustainable spatial planning could efficiently reduce future flood damage at the level of several most critical municipalities. Reference Ernst, J, Dewals, B, Detrembleur, S, Archambeau, P, Erpicum, S, & Pirotton, M. (2010). Micro-scale flood risk analysis based on detailed 2D hydraulic modelling and high resolution geographic data. Natural Hazards, 55(2), 181-209. [less ▲]

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See detailFactors of knickpoint migration on the moderately uplifted Ardennes Plateau, Western Europe
Beckers, Arnaud ULiege; Bovy, Benoît ULiege; Demoulin, Alain ULiege

Poster (2012, April 27)

In the last two decades, much research has been devoted to the development and refinement of numerical models of river incision. In settings of prevailing bedrock channel erosion, numerous studies used ... [more ▼]

In the last two decades, much research has been devoted to the development and refinement of numerical models of river incision. In settings of prevailing bedrock channel erosion, numerous studies used field data, notably knickpoint data, to calibrate the widely acknowledged stream power model of incision and to discuss the specific impact of various variables (e.g., sediment load, channel width) not appearing explicitly in the model’s simplest form. However, most of these studies were conducted in areas of very active tectonics and high relief, thus displaying an exacerbated geomorphic response to the tectonic signal. Here, we analyze the traces left in the drainage network 0.7 My after the NE Ardennes region (western Europe) underwent a moderate 100-150 m uplift. We identify a set of knickpoints that have travelled far upstream in the Ourthe catchment. Because time becomes a more sensitive variable than distance near the headwaters, we fit the stream power model to the data by minimizing time residuals (i.e., the differences between 0.7 My and the modelled times for the knickpoints to reach their actual location) rather than distance residuals. Our best fit of the stream power model parameters yields m/n = 0.75 and K = 4.63 10-8 m-0.5y-1. We suggest that the discrepancy with the m/n value of 0.5 obtained from field and long profile data of the currently graded downstream part of the catchment’s streams points to a narrowing of the bedrock channel at the passage of a knickpoint. Then, the time residuals of the model fit are regressed against quantitative expressions of bedrock resistance to erosion and junction crossing, showing that both variables significantly affect knickpoint migration. In particular, most of the small tributaries with highly delayed knickpoints display all features characteristic of hanging valleys. However, not all such small streams have developed hanging valleys, and further research is needed to unravel how other controls, e.g., amount and size of the tributary bed load, are determining for the creation of such valleys. [less ▲]

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See detailNegative wind anomalies generated a diminution of productivity in the North Atlantic in 2010
Troupin, Charles ULiege; Machín, Francis

Poster (2012, April 27)

The weakening of the wind intensity in winter 2010, related to a low NAO index, generated unseen temperature anomalies and a significant decrease of biological activity in the Canary Current upwelling ... [more ▼]

The weakening of the wind intensity in winter 2010, related to a low NAO index, generated unseen temperature anomalies and a significant decrease of biological activity in the Canary Current upwelling system. [less ▲]

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Peer Reviewed
See detailSubstamce P, CGRP, B-Endorphins, Methionine-Enkephalin expression in human acute dental inflammation aftrer GaAlAs laser therapy
Chavarria Bolanos, Daniel ULiege; Flores-Reyes, Hector; Pozos-Guillen, Amaury

Poster (2012, April 26)

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See detailAre the CMIP5 GCMs able to simulate atmospheric blocking situations over Europe ?
Belleflamme, Alexandre ULiege; Fettweis, Xavier ULiege; Erpicum, Michel ULiege

Poster (2012, April 26)

Some studies show that most General Circulation Models (GCMs) have difficulties to simulate the main observed circulation patterns and their frequencies. However, this does not only impact the GCM based ... [more ▼]

Some studies show that most General Circulation Models (GCMs) have difficulties to simulate the main observed circulation patterns and their frequencies. However, this does not only impact the GCM based projections for future climate, but also the results of downscaling methods using the circulation simulated by GCMs as forcing. Indeed, the downscaling methods are not able to correct the biases introduced by the GCM simulations in the free atmosphere. Here, we focus on the anticyclonic blocking situations over western Europe for summer (June, July and August). Indeed, these blocking situations, which are often related to droughts and heat waves, could become more frequent due to global warming. Moreover, their frequency and persistence depend on the variability of the circulation, which is known to be difficult to reproduce by the GCMs. In order to evaluate the ability of the GCMs to reproduce the observed frequency and persistence of blocking situations, we compare them with two reanalysis datasets (NCEP-NCAR 1 and ECMWF ERA-40) by using an automatic circulation type classification. The daily geopotential height at 500 hPa over the last 30 years of the current climate simulation (Historical experiment, 1976-2005) of all available CMIP5 GCMs prepared for the upcoming IPCC report AR5 is used here. The circulation type classification groups similar daily circulation situations together on basis of a leader-algorithm to obtain a few homogeneous circulation types describing the general circulation of the region. Thus, the frequency and the persistence of each circulation type can be analysed on a daily timescale. We show that the ability of the GCMs to reproduce the observed frequency and persistence of blocking situations is influenced by the anomalies in their circulation type frequency repartition. So, the GCMs which underestimate the frequency of the anticyclonic types tend to simulate less and shorter blocking situations. The contrary is observed for GCMs that overestimate the frequency of these circulation types. This rises questions about the reliability of the future projections for events related to blocking situations. Indeed, when applying the same approach as for the current climate to the future projections (experiments RCP4.5 and RCP8.5), it seems that the blocking situations become more frequent and persistent. However, when considering only the circulation patterns by removing the mean geopotential height increase due to global warming, there is no significant circulation change till 2100. This means that the GCMs conserve their circulation biases in spite of climate change and so, the frequency and the persistence of the blocking situations are projected to remain almost the same as those simulated for the current climate. [less ▲]

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See detailCharacterisation of sand transport in gravel-bed rivers using iron slag dated by historical studies
Houbrechts, Geoffrey ULiege; Levecq, Yannick; Petit, François ULiege

Poster (2012, April 25)

Considerable quantities of iron-smelting slag are present in the bed of the Ardennian rivers. These waste products come from hundreds of ironworks (mainly blast furnaces and finery forges) built close to ... [more ▼]

Considerable quantities of iron-smelting slag are present in the bed of the Ardennian rivers. These waste products come from hundreds of ironworks (mainly blast furnaces and finery forges) built close to different-sized rivers between the 14th and the 19th centuries. In general, slag was crushed by hammers, sorted and piled up in heaps around the furnaces, generally onto the floodplains. Furthermore, some archives mention that they were sometimes thrown out directly into the rivers. This means that for centuries, slag elements have been swept away by floods, mixed with the sediment and spread out along river courses. Due to their distinctive appearance, slag particles are easily recognizable among the natural elements. Thanks to many historical studies conducted on the early iron industry, we are able to date quite precisely the inception and the periods of activity of the different sites established in the catchments. These data are indispensable in order to use slag as a tracer to quantify the particles’ velocity in rivers. Downstream of ironworks, samples of sand have been collected in the surface layer of many gravel-bed rivers. Then, the slag concentration of each sample has been measured in the coarse sand fraction. The representation of the longitudinal evolution of slag concentration in these rivers permits the dispersion of slag to be analysed, the relative bed-material discharges at confluences to be quantified and the velocity of coarse sand to be determined. A survey of the bedload discharge in the Ardennian rivers established that more than 90 % of the bedload transport consists of coarse sand grains that are transported on the bottom of the bed. However, in the literature, this grain-size fraction is generally not considered in bedload discharge estimations because the sandy particles are very difficult to tag and to recover. Consequently, the huge amounts of slag injected in rivers several centuries ago can be considered as a very useful opportunity to characterise the sand transport in gravel-bed rivers. [less ▲]

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See detailEvaluation of the regional climate model WRF over Svalbard
Lang, Charlotte ULiege; Fettweis, Xavier ULiege; Doutreloup, Sébastien ULiege et al

Poster (2012, April 24)

It is well known that high latitude zones are very sensitive to climate change. As a result of global warming, ice sheet melting has increased which in turn has an influence on climate through ... [more ▼]

It is well known that high latitude zones are very sensitive to climate change. As a result of global warming, ice sheet melting has increased which in turn has an influence on climate through modifications of the thermohaline circulation, feedback of ice albedo, sea level rise, … Svalbard is an archipelago between 74 and 81°lat N and 60 percent of its area (62 248 km2) is covered with glaciers and ice sheets. The impact of global warming on the Svalbard cryosphere can be estimated with climate models. However, we need to use regional climate models as they offer the possibility of a higher resolution than general circulation models. We have ran two regional climate models (MAR and WRF) at a 10-kilometre resolution between 2006 and 2010 over Svalbard and compared their simulated climate to near surface measurements at several weather stations through the archipelago in order to determine which one of them could best represent the Svalbard climate. [less ▲]

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See detailReconstruction and analysis of QuikSCAT wind measurements with an EOF-based technique
Troupin, Charles ULiege; Alvera Azcarate, Aïda ULiege; Beckers, Jean-Marie ULiege

Poster (2012, April 24)

QuikSCAT wind products are often used to provide numerical model atmospheric forcing. However, due to the configuration of the satellite swaths, gaps are frequently observed in the daily wind maps. We ... [more ▼]

QuikSCAT wind products are often used to provide numerical model atmospheric forcing. However, due to the configuration of the satellite swaths, gaps are frequently observed in the daily wind maps. We present a solution based on truncated EOF decomposition to fill these gaps. [less ▲]

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See detailIn vitro multiplication of an industrial fiber plant: kenaf (Hibiscus cannabinus L.)
Arbaoui, Sarra; Campanella, Bruno ULiege; Paul, Roger ULiege et al

Poster (2012, April 23)

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See detailEstimation, prévision et contrôle du gisement solaire en région wallonne
Doutreloup, Sébastien ULiege; Fettweis, Xavier ULiege; Erpicum, Michel ULiege

Poster (2012, April 23)

Présentation des activités et des recherches du Laboratoire de Climatologie et Topoclimatologie de l'Université de Liège dans le domaine du rayonnement solaire

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See detailLast millenium environmental changes in Lake Bertrand sediments, Chilean Patagonia
Sacré, Vincent ULiege; Fagel, Nathalie ULiege; Schmidt, Sabine et al

Poster (2012, April 23)

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See detailCarbon balance of an intensive grazed grassland
Jerome, Elisabeth ULiege; Beckers, Yves ULiege; Bodson, Bernard ULiege et al

Poster (2012, April 23)

This work seeks to analyze the C balance of a Belgian grassland grazed by the “Blanc Bleu Belge” breed of cattle. The site is located at Dorinne in the Belgian Condroz (50° 18’ 44’’ N; 4° 58’ 07’’ E; 248 ... [more ▼]

This work seeks to analyze the C balance of a Belgian grassland grazed by the “Blanc Bleu Belge” breed of cattle. The site is located at Dorinne in the Belgian Condroz (50° 18’ 44’’ N; 4° 58’ 07’’ E; 248 m asl.). It is permanent grassland of ca. 4.2 ha with a moderate slope of 1 to 2 %. Homogeneity and topography criteria are met to ensure high quality turbulent flux measurements. The experimental field was equipped with an eddy covariance system. Flux correction, quality control and data gap filling were performed following standardised procedures. This device was completed by a micrometeorological station that measured temperature and humidity respectively in the air and within the soil, radiation, atmospheric pressure and precipitations. Carbon exported through mowing (CNBP,export), imported through compost application (CNBP,import) or through complementary feeds for cattle (CNBP,complement) was also measured. In addition, the vegetation development was followed in order to estimate herbage production and dry matter intake by grazing animals. Carbon lost through CH4 emissions (CNBP,CH4) was finally estimated, allowing the establishment of a full C budget. After one year of measurements (May 2010 - May 2011), the grassland was a net CO2 source (Net Ecosystem Exchange (NEE) = 172 ± 94 g C m-2 year-1). Net Biome Productivity (NBP) was calculated from NEE by taking into account imports and export of organic C and losses of carbon as CH4. Contribution of CNBP,CH4 to NBP was small as it was 12 ± 1 g C m-2 year-1. The balance between CNBP,import and CNBP,export created not such a large departure of NBP from NEE, which is not the case of CNBP,complement. The NBP was finally estimated at 102 ± 95 g C m-2 year-1. At this stage, it is premature to conclude about the sink or source behaviour of the plot because the NBP value is very close to its uncertainty. Moreover, this result was obtained under particular climate conditions, characterised by drought during summer 2010 and spring 2011. First year full carbon budget will be discussed in relation with climate conditions and management practices. A second year of measurements will be also presented. [less ▲]

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See detailEstimating pCO2 from remote sensing in the Belgian Coastal Zone
Borges, Alberto ULiege; Ruddick, Kevin; Harlay, Jérôme ULiege

Poster (2012, April 22)

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See detailVariability of methane in the epilimnion of Lake Kivu
Borges, Alberto ULiege; Abril, G.; Morana, C. et al

Poster (2012, April 22)

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See detailFirst assessment of the biogeochemistry of the upper Congo River
Darchambeau, François ULiege; Bouillon, S.; Borges, Alberto ULiege

Poster (2012, April 22)

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See detailAn original methodology to study the synovial tissue in OA patient
Lambert, Cécile ULiege; Dubuc, Jean-Emile; Henrotin, Yves ULiege

Poster (2012, April 19)

Purpose: Synovial membrane plays a key role in osteoarthritis (OA) pathophysiology, contributing to both patient symptoms and disease progression. Using an original methodology comparing normal/reactive ... [more ▼]

Purpose: Synovial membrane plays a key role in osteoarthritis (OA) pathophysiology, contributing to both patient symptoms and disease progression. Using an original methodology comparing normal/reactive (N/R) and inflammatory (I) synovial membrane areas from the same OA patient, we investigated the crosstalk between inflammation and angiogenesis. We also analyzed the gene expression pattern of synovial cells from these different areas and identified differentially regulated pathways. Methods: Synovial cells (SC) were isolated from OA synovial specimens obtained from patients undergoing knee replacement. The inflammatory status of the synovial membrane was characterized by the surgeon according the macroscopic criteria including the synovial vascularization, the villi formation and the hypertrophic aspect of the tissue. At the surgery time, the synovial membrane was dissected and the biopsies from N/R and I areas cultured separately for a period of 7 days. Inflammatory and angiogenic mediators were evaluated in the culture supernatant by immunoassays (ELISA) or visualized by immunohistochemistry. Gene expression profiling between N/R and I areas was performed using Illumina’s multi-sample format human HT-12 BeadChip (Illumina Inc.). Results: Immunohistochemistry showed an increase of lymphocyte infiltration, vascular density and VEGF expression in I compared N/R synovial biopsies. Synovial cells from I areas produced more IL-6, IL-8 and VEGF but less TSP-1 than cells isolated from N/R synovial biopsies. By microarray analysis, 896 differentially expressed genes between N/R and I zones were identified. Among them, 576 genes were upregulated (I/NR > 1.5) and 320 downregulated (I/NR  0.75). A significant number of the top ranking differentially expressed genes were identified as inflammatory, cartilage metabolism, Wnt or angiogenic pathways. Conclusion: In this study, we have demonstrated the pro-inflammatory and pro-angiogeneic status of I area of the OA synovial membrane. Using a unique culture system, this study is the first to identify different expression pattern between two areas of the synovial membrane in the same OA patient. This original methodology could be further used to go deeper into the knowledge of the role of synovial membrane in OA. Possibilities for valorization: This analysis provided interesting information regarding new potent intermediates that could be potential new targets for the diagnosis or treatment of OA. [less ▲]

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See detailPossible intracellular effect of the new water-soluble form of curcumin (NDS27) on the oxidant response of stimulated neutrophils
Derochette, Sandrine ULiege; Mouithys-Mickalad, Ange ULiege; Deby-Dupont, Ginette et al

Poster (2012, April 18)

Neutrophils (PMNs) are involved in host defense against infections through the production of reactive oxygen species (ROS) to kill pathologic agents. But, an excessive ROS production, called “oxidative ... [more ▼]

Neutrophils (PMNs) are involved in host defense against infections through the production of reactive oxygen species (ROS) to kill pathologic agents. But, an excessive ROS production, called “oxidative stress” is associated with tissue damages and development of chronic or acute inflammatory diseases. PMNs are prime therapeutic targets to control inflammatory events associated to ROS production. Nowadays, there is a growing interest for the use of polyphenolic molecules to modulate the inflammatory response. The aim of this work was to study the antioxidant effect of NDS27 (1), a new highly water-soluble form of the polyphenolic molecule curcumin, on in vitro stimulated equine PMNs. NDS27 (10-6 to 10-4 M) was pre-incubated with cells and eliminated before their activation. The ability of NDS27 to enter into the cells was checked by HPLC from the cellular extracts. The intracellular ROS production by phorbol myristate acetate (PMA) stimulated PMNs was measured by fluorescence using 2’,7’-dichlorofluorescin diacetate. Lucigenin dependent chemiluminescence was used to measure extracellular ROS production. Additionally, the effect of NDS27 was tested on the activity of myeloperoxidase (MPO), a hemic enzyme contributing to the oxidant response of neutrophils. The activity of the released MPO by cytochalazine B (CB) and N-formyl-methionyl-leucyl-phenylalanine (fMLP) stimulated PMNs was measured by SIEFED (“Specific Immunologic Extraction Followed by Enzymatic Detection”) (2). The HPLC results showed that NDS27 enters into PMNs and interacts with their membrane. NDS27 significantly and dose-dependently inhibited the ROS production in neutrophils without affecting their viability. Likewise, the activity of MPO released by PMNs was lowered by NDS27. Overall, our findings demonstrate that the membrane of neutrophils is permeable to NDS27 or interacts with the drug, suggesting that its inhibitory effect on ROS production is mainly associated to an intracellular effect probably by acting on the enzymes implied in respiratory burst like NADPH oxidase and MPO. The modulatory effect of NDS27 towards the oxidant activity of cells involved in immune and inflammatory response open therapeutic perspectives to control equine or human pathologies with excessive inflammatory reactions. 1. Neven et al. 2011, Patent Application Publication: US2011/0257126 A1 2. Serteyn et al. 2005, European Patent Specification : EP1711817 B1 [less ▲]

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See detailA sustainable method inspired by nature for the production of original bi-functional nutraceuticals containing prebiotic fibers and highly bio-available forms of calcium and magnesium
Goffin, Dorothée ULiege; Blecker, Christophe ULiege; Paquot, Michel ULiege

Poster (2012, April 18)

A sustainable method inspired by nature is proposed leading to an original bifunctional product active on gut health, metabolism regulation, immunity and mineral fortification, fighting against topical ... [more ▼]

A sustainable method inspired by nature is proposed leading to an original bifunctional product active on gut health, metabolism regulation, immunity and mineral fortification, fighting against topical chronic diseases (type2 diabetes, osteoporosis, colon cancer…). [less ▲]

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See detailOptimization of recombinant root-secreted IgGs production in Arabidopsis thaliana by screening cell wall mutants
Boulanger, Benoit ULiege; Périlleux, Claire ULiege; Tocquin, Pierre ULiege

Poster (2012, April 18)

The production of complex heterologous proteins (e.g. monoclonal antibodies, mAbs) in plants has several advantages animal based systems such as low cost, scalability and limited risk of contamination by ... [more ▼]

The production of complex heterologous proteins (e.g. monoclonal antibodies, mAbs) in plants has several advantages animal based systems such as low cost, scalability and limited risk of contamination by human pathogens. mAbs are glycoproteins that require to be targeted to the plant secretory pathway in order to be properly folded and matured. They are ultimately delivered in the cell wall and are expected to be freely released in the extracellular space and the external medium, which would greatly simplify downstream processing. However, a significant part of plant produced and secreted mAbs remains bound to the cell wall, therefore hindering recovery. In this study, we evaluated the extra-cellular release of root-secreted proteins of wild-type plants and cell wall mutants of Arabidopsis thaliana. Recovered protein were either analyzed by SDS-PAGE for full proteome profiling or by gelatin zymography to reveal the activity of cell wall-bound proteases. The production, secretion and release of recombinant IgG will be eventually studied in transgenic hairy-roots generated from selected mutants. [less ▲]

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See detailHemocompatibility of nanocarriers designed to transport biopharmaceutical drugs
Sevrin, Chantal ULiege; Cerda, Bernardino; Lombart, François ULiege et al

Poster (2012, April 18)

The optimization of nanoparticles (NP) for drug delivery, in particular to target the BBB, imposes to verify their hemocompatibility both for toxicological and efficiency of targeting perspectives. Indeed ... [more ▼]

The optimization of nanoparticles (NP) for drug delivery, in particular to target the BBB, imposes to verify their hemocompatibility both for toxicological and efficiency of targeting perspectives. Indeed the large surface they are able to expose to the biological environment promotes their interaction with various biochemicals, in particular proteins which can after adsorption elicit the activation of biological cascades either responsible from NP clearance or/and harmful body reaction (inflammatory / coagulation). In the frame of the European Integrated Project : “Nanobiopharmaceutics”, we have the opportunity to compare the hemoreactivity of about 145 different NP samples differing in core and surface chemistry and classified according to their expected difference in hydrophobicity based on the nature of their core materials. According to this classification, PLGA nanoparticles, polyglycidol-polyethyethylene oxide nanoparticles, polyglycidol thyolated or polyacrylamide nanogels, and polyelectrolyte complexes either based on polyamidoamine or poly(N,N-dimethylamino-2-ethylmethacrylate) have been evaluated within a concentration ranging from 0.3 to 1000 =g/mL. These in vitro tests have been realized for screening purpose adopting normal human bloods and according to Iso 10993. As a summary of this extensive study, our results clearly highlight that most of the polymeric nanoparticles evaluated give rise to some alterations of the blood components. In particular the platelets, intrinsic pathway of coagulation and complement activation are the most reactive biological parameters in the presence of these nanostuctures. Although not strictly related to the surface chemistry our classification has also allowed us to derive some clear correlations between nanomaterial properties and their hemoreactivity. Within the class of polyelectrolyte electrolyte complexes, the modifications brought in the surface chemistry has drastically improved their hemoreactivity. [less ▲]

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See detailInteractions of KLF4 and SIP1 in the regulation of E-Cadherin expression
Koopmansch, Benjamin ULiege

Poster (2012, April 18)

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See detailOptimisation of new biodegradable microcarriers tailored for tissue engineering
Demina, T; Akopova, T; Tsoy, A et al

Poster (2012, April 18)

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See detailNeuropeptides and endogenous opioids expression during silent chronic inflammation
Chavarria Bolanos, D; de Jesus Pozos Guillén, A; Grandfils, Christian ULiege et al

Poster (2012, April 18)

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See detailDegradation of recombinant IgG by root-secreted proteases of Arabidopsis thaliana and Nicotiana tabacum
Désiron, Carole ULiege; Lallemand, Jérôme ULiege; Périlleux, Claire ULiege et al

Poster (2012, April 18)

Plants are promising hosts for the production of complex recombinant pharmaceuticals, such as antibodies (mAbs), because they offer an inexpensive and safer alternative to traditional production systems ... [more ▼]

Plants are promising hosts for the production of complex recombinant pharmaceuticals, such as antibodies (mAbs), because they offer an inexpensive and safer alternative to traditional production systems. The plant-based production of mAbs, which are multimeric glycoproteins, require their targeting to the secretory pathaway where they are properly folded and matured. However, co-secretion of endogenous proteases, which can represent up to 10% of the extracellular proteins (secretome), is known to significantly alter the yield and quality of secreted mAbs. In this study, we analyzed the proteolytic activities in root-secretome of Arabidopsis thaliana and Nicotiana tabacum. Root-secretomes were recovered by salt extraction and the protease activity was assayed in vitro or by zymography, in a range of pH. The relative contribution of protease classes was evaluated with specific inhibitors. [less ▲]

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See detailCharacterisation of metal binding affinities of HMA4 from Arabidopsis halleri
Laurent, Clémentine ULiege

Poster (2012, April 18)

Detailed reference viewed: 30 (1 ULiège)
See detailMolecular biomimetics applied to medical devices
Van de Weerdt, Cécile ULiege; Vreuls, Christelle ULiege; Genin, Alexis ULiege et al

Poster (2012, April 18)

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See detailNew Advances for In Situ Protein Identification by MALDI In-Source Decay FTMS Imaging
Calligaris, David ULiege; Zimmerman, Tyler ULiege; Debois, Delphine ULiege et al

Poster (2012, April 18)

MALDI imaging mass spectrometry has proven to be effective for the discovery and the monitoring of disease-related proteins. With this technique a molecular analysis could be performed directly from ... [more ▼]

MALDI imaging mass spectrometry has proven to be effective for the discovery and the monitoring of disease-related proteins. With this technique a molecular analysis could be performed directly from tissue sections in the region of the diseased area. The use of in-source decay (ISD), allowing fast and reliable sequences assignments of proteins termini, has proven to be a crucial tool for proteins identification in solution and tissue slices. However, it is necessary to develop additional tools that allow unambiguous assignment of proteins sequences in complex tissue slices. The development of bioinformatic tools and the use of ultra-high mass resolution and high mass accuracy of Fourier transform ion-cyclotron (FTICR) mass spectrometry are ideal for this purpose. In this study, we show that FTICR mass spectrometry combined with data filtering with a software that subtracts matrix peaks aid protein identification. All measurements were carried out on a SolariX FTMS (9.4 Tesla) equipped with a Dual Source with a smartbeamTMII laser (Bruker Daltonics). Mouse brain tissue slices of 14 µm thickness were rinsed to obtain optimal sensitivity and high-quality ions. Before matrix application, a spot of myelin was deposited near mouse brain. 1,5-Diaminionaphtalene was sprayed using an ImagePrep (Bruker Daltonics). Results were interpreted using BioToolsTM 3.2 in combination with MascotTM (Matrix Science) for ISD spectra and FlexImagingTM 3.0 for MALDI-ISD imaging experiments. Matrix peaks were subtracted using an in-house written Java code that sequentially scans all peak lists from acquired spectra against the DAN mass list. Then, another Java code allows to create 2D ion images at selected m/z ratios. The studies were carried out by MALDI-ISD imaging to create interest on FTICR mass spectrometer for proteins identification in the field of biomarkers characterization. It is demonstrated that protein ISD leads to the same pattern of fragmentation observed during MALDI-TOF analyzes. Fragmentation generates cn- and zn-series ions of myelin in presence of DAN. The internal calibration of all the data provides a mass accuracy neighboring 2.5 ppm over the m/z range of interest (300-2500 Da) and a mass resolution of 70000 at m/z 400 Da. It allows the assignment of ISD fragments of proteins in the low mass range (m/z between 300 and 900) that is unambiguously validated by the “ISD signal” recorded from the spots of pure protein solution (myelin) near tissue slice. Moreover, the use of our software “cleans” MS imaging data by reducing/eliminating MALDI matrix peaks that are isobaric to an analyte peak. Novel aspect This study evidences the main input of FTICR mass spectrometer for pathologies diagnosis based on biomarkers localization and identification by MALDI-ISD imaging. [less ▲]

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See detailSynthesis and evaluation of boronic acids as inhibitors of Penicillin Binding Proteins of classes A, B and C
Zervosen, Astrid ULiege; Sauvage, Eric ULiege; Bouillez, André ULiege et al

Poster (2012, April 18)

The widespread use of beta-lactam antibiotics has lead to the worldwide appearance of drug-resistant strains. Bacteria have developed resistance to beta-lactams by three main mechanisms: the production of ... [more ▼]

The widespread use of beta-lactam antibiotics has lead to the worldwide appearance of drug-resistant strains. Bacteria have developed resistance to beta-lactams by three main mechanisms: the production of beta-lactamases that catalyze hydrolysis of beta-lactams, the production of low-affinity, drug resistant Penicillin Binding Proteins (PBPs) and the over expression of resistant PBPs. PBPs are interesting targets because they catalyse the last steps of the biosynthesis of peptidoglycan, which is unique in bacteria and has no mammalian analogs, outside the cytoplasmic membrane. Various non-ß-lactam inhibitors of PBPs have been developed with the objective of attempting to stall the development of ß-lactam resistance. Boronic acids are potent beta-lactamase inhibitors and have been shown to display some specificity for soluble transpeptidases and PBPs, but their potential as inhibitors of the latter enzymes is yet to be widely explored. Recently, a (2, 6-dimethoxybenzamido)methylboronic acid was identified as being a potent inhibitor of Actinomadura sp. R39 transpeptidase (IC50: 1.3 µM). Here, we will discuss the synthesis of a number of acylaminomethylboronic acids, analogs of (2, 6-dimethoxybenzamido)methylboronic acid, and their potential as inhibitors of PBPs. Several boronic acids of this library were able to inhibit PBPs of classes A, B and C from penicillin sensitive strains. Thus (2-nitrobenzamido)methylboronic acid was identified as a good inhibitor of class A PBP (PBP1b from S. pneumoniae, IC50 = 26 µM), class B PBP (PBP2xR6 from S. pneumoniae, IC50 = 138 µM) and class C PBP (R39 from Actinomadura sp., IC50 = 0.6 µM). Crystal structures of complexes of R39 and PBP1b with boronic acid analogs of our library have already been solved and allowed an interpretation of results. We believe that this work opens new avenues towards the development of molecules that will inhibit PBPs, and eventually display bactericidal effect, on distinct bacterial species. [less ▲]

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See detailInfluence of protein context on the propensity of polyglutamine tracts to induce protein aggregation into amyloid fibrils
Huynen, Céline ULiege

Poster (2012, April 18)

Nine neurodegenerative diseases, referred to as polyglutamine diseases, are associated with nine proteins containing an expanded polyglutamine (polyQ) tract. PolyQ tracts are encoded by a repetition of ... [more ▼]

Nine neurodegenerative diseases, referred to as polyglutamine diseases, are associated with nine proteins containing an expanded polyglutamine (polyQ) tract. PolyQ tracts are encoded by a repetition of the CAG codon in the corresponding genes, and are present in proteins of healthy people. They are however pathogenic when their length, due to mutations, becomes higher than a threshold generally comprised between 35 and 45Q. Such pathogenic tracts trigger the aggregation of the proteins into amyloid-like aggregates that could play an important role in the disease. It is therefore necessary to investigate at a molecular level the aggregation process of polyQ proteins. Since proteins associated with polyQ diseases are generally big and relatively insoluble, they are difficult to produce and manipulate. We have therefore decided to study the aggregating properties of polyQ proteins by designing and characterizing model proteins made of a well-characterized host protein, the β-lactamase BlaP, and polyQ tracts of different lengths (23 to 79Q) inserted at position 197 of BlaP. The aggregating properties of these BlaP chimeras recapitulate those of proteins associated with polyQ diseases. We indeed observed that there is a minimal number of glutamines (threshold) required for chimeras aggregation into amyloid-like fibrils and that the kinetics of aggregation are faster with longer glutamine repeats. Most importantly, the value of the threshold for amyloid-like fibril formation seems to critically depend on the structural integrity of BlaP and thus on the constraints applied to the polyQ tract. In the present work, we investigate more deeply the role of the protein context and the role of oligomers in the process of aggregation of BlaP chimeras. This study is mainly based on the use of two techniques: the quartz crystal microbalance with dissipation (QCM-D) in combination with atomic force microscopy (AFM), and the dynamic light scattering (DLS). Preliminary QCM-D results indicate that in native condition there is a minimal number of glutamines required for the elongation of BlaP197(Gln)79 fibrils by BlaP chimeras. This threshold is different to that observed for the aggregation monitored in solution in absence of seed. Most interestingly it corresponds to the threshold observed in denaturing conditions. These observations suggest that the conformation of BlaP is the limiting step for amyloid fibril formation by interfering with the nucleation step. Preliminary DLS experiments indicate that the oligomers formed by BlaP197(Gln)79 in native condition are on the pathway of amyloid fibril formation and could act as aggregation nuclei. [less ▲]

Detailed reference viewed: 41 (4 ULiège)
See detailInnovative multilayered nanofibers for wound dressing application
Croisier, Florence ULiege; Detrembleur, Christophe ULiege; Jérôme, Christine ULiege

Poster (2012, April 18)

Chitosan is a natural polymer derived from the chitin of crustacean or mushroom shells, that intrinsically presents haemostatic, mucoadhesive, antimicrobial and immunostimulant properties. This ... [more ▼]

Chitosan is a natural polymer derived from the chitin of crustacean or mushroom shells, that intrinsically presents haemostatic, mucoadhesive, antimicrobial and immunostimulant properties. This polysaccharide has shown a great potential for biomedical and pharmaceutical applications, on account of its remarkable compatibility with physiological medium. Besides, it is degraded in a physiological environment into non-toxic products, which make chitosan an outstanding candidate for short- to medium-term applications. In this respect, nanometric fibers are highly interesting as their assembly mimics the skin extracellular matrix structure. Such nanofibrous materials can be prepared by electrospinning (ESP). This technique uses a high voltage to create an electrically charged jet of polymer solution or melt which leads to fibers formation. Depending on the polymer characteristics (a.o. molecular weight, solution viscosity and conductivity) and processing conditions (electric potential, distance between syringe-capillary and collection plate, concentration, flow rate), polymer fibers ranging from nanometers to a few microns in diameter can be obtained and subsequently used as potential scaffolds, a.o. to form a temporary, artificial extracellular matrix. In the present study, electrospinning technique was combined with layer-by-layer deposition method (LBL) - a well-known method for surface coating, based on electrostatic interactions - in order to prepare multilayered chitosan-based nanofibers. The antibacterial properties of the obtained material were then assessed, and the presence of a multilayered deposit was confirmed by several techniques. (Future) possibilities for valorization: These multilayered chitosan-based nanofibers present great prospects for the preparation of new biomedical scaffolds - such as wound dressings that could improve skin regeneration. [less ▲]

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See detailClostridium difficile in farm and slaughter animals in Belgium: detection and characterization
Rodriguez Diaz, Cristina ULiege; Taminiau, Bernard ULiege; Van Broeck, Johan et al

Poster (2012, April 18)

Detailed reference viewed: 17 (2 ULiège)
See detailPsychrotrophic and psychrophylic Clostridium responsible for meat spoilage
Rodrigues, A.; Taminiau, Bernard ULiege; Daube, Georges ULiege

Poster (2012, April 18)

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See detailInvestigation of nanoparticles as potential activators for the optimization of PAH biodegradation
Masy, Thibaut ULiege; Wannoussa, Wissal ULiege; Lambert, Stéphanie ULiege et al

Poster (2012, April 10)

These last decades, through the industrial development and its imperfect waste management, the contamination by hydrocarbons in water and soils has led to a progressive deterioration of environmental ... [more ▼]

These last decades, through the industrial development and its imperfect waste management, the contamination by hydrocarbons in water and soils has led to a progressive deterioration of environmental quality, which is more and more considered nowadays. Amongst all the existing cleaning-up techniques, the bioremediation appears as the best compromise between treatment costs and effectiveness. However, this bioprocess remains time-consuming, especially for persistent pollutants as PAHs (Polycyclic Aromatic Hydrocarbons). A first way to improve the biodegradation consists in adding a consortium of efficient microorganisms in the polluted area (bioaugmentation). A further way to improve the bioremediation rate is based on the use of nutrients to assist the microbial metabolism (biostimulation). Our project gathers these two methods, specifically for the PAH biodegradation of polluted soils. Firstly, different suitable strains from our lab will be compared together in terms of PAH-degrading rate, in order to select the best microorganisms. As all these strains were selected from a long-term oil-polluted dried soil, they should be able to compete against the endogenous microflora, even if they are injected in the soil in a powdered starter. Secondly, trace elements in the nanoparticulate form, with concentrations of about 10-5M, will be added to catalyze the bacterial metabolism. First results already showed a sharp increase (2 to 3 fold) in the biodegradation kinetics, which is promising for the further scaling-up stages. In addition, this PhD project attempts to understand the mechanism of interaction between bacteria and nanoparticulate catalysts. [less ▲]

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See detailCALCIUM HYDROXIDE LOADED PLGA MICROSPHERES FOR ENDODONTICS: EFFECT OF FORMULATION METHOD ON Ca++ RELEASE PROFILE
Chavarria Bolanos, Daniel ULiege; Cerda-Cristerna, BI; Flores-Reyes, Hector et al

Poster (2012, April 04)

Detailed reference viewed: 26 (1 ULiège)
See detailPierres à aiguiser en Gaule Belgique et en Germanie : mise en place d'une typologie et identification des matériaux
Thiebaux, Aurélie ULiege; GOEMAERE, Eric; Henrotay, Denis et al

Poster (2012, April 04)

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See detailUnderstanding of the Venus upper atmosphere dynamics with O2(a1 ) Venus Express observations
Soret, Lauriane ULiege; Gérard, Jean-Claude ULiege; Piccioni, Giuseppe et al

Poster (2012, April)

The O2(a1 ) nightglow emission at 1.27 m may be used as a tracer of the dynamics prevailing in the Venusian upper mesosphere. This emission has thus been observed with ground-based telescopes and from ... [more ▼]

The O2(a1 ) nightglow emission at 1.27 m may be used as a tracer of the dynamics prevailing in the Venusian upper mesosphere. This emission has thus been observed with ground-based telescopes and from space with instruments such as VIRTIS on board Venus Express. Observations have shown that the emission maximum is statistically located close to the antisolar point at 96 km. As originally suggested by Connes et al. (1979), such an emission results from the production of oxygen atoms on the Venus dayside by photodissociation and electron impact dissociation of CO2 and CO, which are then transported to the nightside by the subsolar to antisolar general circulation, where they recombine to create excited O2(a1 ) molecules. Their radiative deexcitation produces the O2(a1 ) nightglow with a maximum near the antisolar point. However, VIRTIS observations indicate that the O2(a1 ) nightglow emission is highly variable, both in intensity and location. Actually, when considering individual observations, the patch of bright emission is rarely located at the antisolar point and the brighter area around this point is the result of statics accumulation. Also, when considering several individual observations acquired in a short period of time, it is possible to follow an individual emission patch and to deduce its displacement and its brightness variation due to activation or deactivation. In this study, we analyze several sequences of VIRTIS observations in order to understand the Venus upper mesosphere dynamics.We show that the intensity can vary by several megaRayleighs in a couple of hours with effective lifetimes on the order of several hours. The horizontal motion of the spots leads to the conclusion that winds in the 95-100 km region are in the range of 25 to 150 m s-1, in good agreement with the study by Hueso et al. (2008). [less ▲]

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See detailEngineering geological mapping in Wallonia (Belgium) : present state and recent computerized approach
Delvoie, Simon ULiege; Radu, Jean-Pol ULiege; Ruthy, Ingrid ULiege et al

Poster (2012, April)

An engineering geological map can be defined as a geological map with a generalized representation of all the components of a geological environment which are strongly required for spatial planning ... [more ▼]

An engineering geological map can be defined as a geological map with a generalized representation of all the components of a geological environment which are strongly required for spatial planning, design, construction and maintenance of civil engineering buildings. In Wallonia (Belgium) 24 engineering geological maps have been developed between the 70s and the 90s at 1/5,000 or 1/10,000 scale covering some areas of the most industrialized and urbanized cities (Liège, Charleroi and Mons). They were based on soil and subsoil data point (boring, drilling, penetration test, geophysical test, outcrop. . . ). Some displayed data present the depth (with isoheights) or the thickness (with isopachs) of the different subsoil layers up to about 50 m depth. Information about geomechanical properties of each subsoil layer,useful for engineers and urban planners, is also synthesized. However, these maps were built up only on paper and progressively needed to be updated with new soil and subsoil data. The Public Service of Wallonia and the University of Liège have recently initiated a study to evaluate the feasibility to develop engineering geological mapping with a computerized approach. Numerous and various data (about soil and subsoil) are stored into a georelational database (the geotechnical database – using Access, Microsoft®). All the data are geographically referenced. The database is linked to a GIS project (using ArcGIS, ESRI®). Both the database and GIS project consist of a powerful tool for spatial data management and analysis. This approach involves a methodology using interpolation methods to update the previous maps and to extent the coverage to new areas. The location (x, y, z) of each subsoil layer is then computed from data point. The geomechanical data of these layers are synthesized in an explanatory booklet joined to maps. [less ▲]

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See detailCalcium-induced conformational changes of the elicitor and membrane-active fengycin
Nasir, Mehmet Nail ULiege; Lins, Laurence ULiege; Ongena, Marc ULiege et al

Poster (2012, April)

Fengycin is a natural lipopeptide synthetized by Bacillus subtilis strains. It is characterized by strong antifungal and low hemolytic activities. It seems also play a role in the promoting of elicitor ... [more ▼]

Fengycin is a natural lipopeptide synthetized by Bacillus subtilis strains. It is characterized by strong antifungal and low hemolytic activities. It seems also play a role in the promoting of elicitor activities of other compounds. The target of the biological activities of fengycin is supposed to be plasma membrane of sensitive cells. Even though the natural fengycin from has been discovered 25 years ago, nowadays, there is an increase of interest for this compound because of its potent applications. Until 15 years ago, the primary structure of fengycin was a matter of open debate before the publication of the corrected structure obtained by nuclear magnetic resonance and mass spectroscopy techniques. Although the infrared and ultraviolet absorption spectra of the lipopeptide were measured, no detailed analysis of these data was performed probably because of the unconventional sequence of the lipopeptide making these kinds of analyses complicated. In this work, our attempt was to analyze the conformational properties of fengycin as well as the calcium-induced changes using two complementary spectroscopic methods, Fourrier transformed infrared spectroscopy (FTIR) and circular dichroism (CD). In a first step, we have characterized the conformational properties of pure fengycin. The lipopeptide adopts turn conformation in trifluoroethanol, a membrane-mimicking solvent. D-aminoacids seem to be involved in intra molecular hydrogen bonds. In a second step, we have investigated the role played by Ca2+ ions on the possible conformational changes of fengycin. The addition of calcium gives rise to important modifications of the conformation. As fengycin has two glutamate residues, calcium is supposed to bind to their side chains. In conclusion, we have demonstrated that the conformation of fengycin is closely depending of the environment and the presence of calcium ions play an important role on the conformational changes of the lipopeptide. Moreover, spectra obtained both FTIR and CD methods ascertain the presence of turn conformation. [less ▲]

Detailed reference viewed: 90 (9 ULiège)