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See detailAssociation entre le contrôle de la pression artérielle et le rapport sodium/potassium urinaire chez les transplantés rénaux hypertendus
Saint-Remy, Annie ULg; SOMJA, Mélanie ULg; WEEKERS, Laurent ULg et al

Poster (2011, December 15)

Design and method : Office blood pressure (OBP) and home BP (HBP) were measured in 70 kidney transplant patients (KT) (43 men/27 women;KT>1 year), all were treated with antihypertensive drugs (mean number ... [more ▼]

Design and method : Office blood pressure (OBP) and home BP (HBP) were measured in 70 kidney transplant patients (KT) (43 men/27 women;KT>1 year), all were treated with antihypertensive drugs (mean number: 2±1). Mean age: 56±11 years, mean graft survival: 7±6.6 years, mean GFR: 65.6±24 ml/min, diabetes:27% and current smoking:11.5%. HBP (Omron M6) was measured during 7 days following the OBP measurement, mean HBP was calculated from day 2 to day 7. Uncontrolled BP was defined by OBP>=140-90 (>=130-80 when diabetes) and HBP>=135-85 (>=130-80 when diabetes). The day of the OBP measurement and the last day of HBP, patients collected 24h- urine and recorded at the same time their food and beverage consumption. Sodium and potassium were measured in urines and their intakes were quantified through food records. Urinary and diet Na+, K+ did not differ between the two urine collections 7 days apart. Results: 16 patients(23%) had controlled BP (OBP and HBP) while 34 (49%) remained with sustained hypertension (SHT) despite treatment, 14 (20%) had masked uncontrolled hypertension (MHT, OBP<140-90 and HBP>=135-85,130-80 if diabetes for both).When comparing the controlled and SHT, no differences were found with age, graft survival, BMI, GFR, calcineurin inhibitors or number and type of antihypertensive drugs. The groups did not differ by their sodium excretion (154±93 vs 162±88 mmol/24h) but well by their K excretion significantly higher in controlled patients (68±17 vs 53±20 mmol/24h,p=0.018) giving a Na/K ratio higher in SHT (3.2±1.3 vs2.2±1.2,p=0.03). Diet analysis showed significantly higher intakes of K (fruits, vegetables) in controlled patients (3279±753 vs 2208±720 mg/24h,p=0.010) whereas both groups consumed on average 9 g/24h of salt. When controlled for age, BMI and Na excretion, Home systolic BP was inversely and significantly correlated with urinary potassium (- 0.46;P=0.002) while no correlation was found with urinary Na.Conclusions: KT patients remaining hypertensive and well controlled patients had both high salt consumption. However, well controlled patients differed by significant higher potassium intakes and excretion. Urinary Na/K ratio could be a useful tool contributing to an optimal BP control in KT patients. However, impact of increasing potassium intakes on uncontrolled BP in KT has to be validated by prospective randomized studies [less ▲]

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See detailFonctions visuo-perceptives et spatiales chez les enfants IMC
Schmetz, Emilie ULg; Detraux, Jean-Jacques ULg

Poster (2011, December 12)

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See detailCaractérisation des viandes bovines à très longue durée de conservation sous vide
Didimo Imazaki, Pedro Henrique ULg; Nezer, Carine ULg; Taminiau, Bernard ULg et al

Poster (2011, December 09)

Le but de cette étude a été d’évaluer la conservabilité de viandes bovines de différentes origines (Royaume-Uni et Irlande, Australie et Brésil) et l’influence sur celle-ci de la température de ... [more ▼]

Le but de cette étude a été d’évaluer la conservabilité de viandes bovines de différentes origines (Royaume-Uni et Irlande, Australie et Brésil) et l’influence sur celle-ci de la température de conservation (1 °C vs. +4 °C). Des paramètres physico-chimiques (pH, couleur, proportion des différentes formes redox de la myoglobine (FRMb), indice TBARS et acides organiques) et microbiologiques (flore aérobie totale, flore lactique, Enterobacteriaceae, Pseudomonas spp. et Brochothrix thermosphacta) ont été mesurés sur sept lots de contre-filet conditionnés sous vide : aux ⅔ de la DLC et à la fin de la DLC. La diversité bactérienne a été évaluée par galeries API50 CHL et par métagénomique. Le pH a diminué au cours de la conservation dans deux lots. La couleur et la proportion des FRMb sont restées stables. Une augmentation de l’indice TBARS, plus prononcée à +4 °C, a été observée. Les viandes australiennes et brésilienne ont présenté des taux en acides acétique et citrique plus élevés. Tous les lots conservés à 1 °C ont présenté une qualité microbiologique satisfaisante à la fin de leur DLC (viandes britanniques et irlandaises = 35 ~ 45 jours; australiennes = 140 jours et brésilienne = 120 jours). La conservation à +4 °C a favorisé la croissance d’entérobactéries, facteur limitant de la conservation de plusieurs lots. L’identification bactérienne a révélé la présence de bactéries connues pour leur effet bioprotecteur. La phase ultérieure de ce travail consistera à étudier la dynamique de la flore microbienne endogène en fonction des conditions environnementales appliquées (température, atmosphère). [less ▲]

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See detailZoonotic diseases in pet birds -a short review
Boseret, Géraldine ULg

Poster (2011, December 09)

The term « Pet bird » designates birds housed and breeded for an exclusively ornamental use. This category includes mainly Passeriformes (canaries, finches…) and Psittaciformes (parrots, parakeets…), and ... [more ▼]

The term « Pet bird » designates birds housed and breeded for an exclusively ornamental use. This category includes mainly Passeriformes (canaries, finches…) and Psittaciformes (parrots, parakeets…), and is a not-so-well known vet’s clientship fraction. Many families indeed own their « kitchen canary », which represent a lucrative business for pet shops or local breeders (e.a. via birds fairs and markets). Besides, some birds are bred for their very high value; for example, in the case of canaries, male and female reproductors with recognized genetic potential are presented in international contests for their posture (the Bossu Belge : fig 1a), their colour (red mosaic: fig 1b) and for their song (Harzer: fig 1c) and sold for rising prices. Finally, exotic birds like parrots (ara, cockatoo…), legally or illegaly traded from Asia, are however very popular pets and profusely represented in zoos and parks. Notwithstanding these economic facts, these animals are potential carriers and/or transmitters of zoonotic diseases. Some of them could have an important impact on human health, like ornithosis, salmonellosis or even H5N1 high pathogenic avian influenza. This review, although non exhausive, has as aim to enlighten, by the description of several cases of birds-humans transmission the risks encountered by birds owners, including children, and on another point of view to assess the potential economic consequences. [less ▲]

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See detailGestion des ressources génétiques animales par les éleveurs de dromadaires de la région d’Ansongo (Mali).
Traore, Bakary; Ouologuem, Bara; Antoine-Moussiaux, Nicolas ULg et al

Poster (2011, December 09)

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See detailLes races de poules belges de grande taille
Moula, Nassim ULg; Jacquet, Michel; Verelst, Andy et al

Poster (2011, December 09)

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See detailLa gouvernance environnementale au Sri Lanka
Rosillon, Caroline ULg

Poster (2011, December 08)

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See detailLe projet de recherches SAFE
Marique, Anne-Françoise ULg; De Meester, Tatiana; De Herde, André et al

Poster (2011, December 08)

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See detailAssessment of Mytilus galloprovincialis to monitor 19 trace elements in the Calvi Bay
Richir, Jonathan ULg; Vermeulen, Simon; Biondo, Renzo ULg et al

Poster (2011, December 08)

Mussel caging with Mytilus galloprovincialis has been successively used to monitor classic trace metal (Cd, Cu, Zn, Cr, Fe, Ni, Pb) pollution of Mediterranean coastal waters at spatial scales ranging from ... [more ▼]

Mussel caging with Mytilus galloprovincialis has been successively used to monitor classic trace metal (Cd, Cu, Zn, Cr, Fe, Ni, Pb) pollution of Mediterranean coastal waters at spatial scales ranging from 10 to 100km. However, its relevance as bioindicator at smaller scales (100 m - 1 km) is poorly known. Moreover, the levels of some little studied trace elements (Al, V, Mn, Sb, Sn, Ag, Mo, Se, As, Co, Be, Bi), recently identified as potential pollutants of coastal environments, have not yet been assessed in that species. In this work, M. galloprovincialis was used to monitor the 19 listed trace elements at the scale of the Calvi Bay (NW Corsica, France). Additionally, we investigated decontamination kinetics and trace element tissue speciation before and after spawning. Mytilus galloprovincialis trace element levels reflect the good water quality of the Calvi Bay, showing little spatial variations either at 100m or 1km scales. Filter feeders are only influenced by their relatively homogeneous pelagic environment (dissolved trace elements and suspended particulate matters), in contrast to organisms which inhabit typically heterogeneous benthic habitats. This bioindicator, a convincing candidate for the monitoring of the 12 little studied trace elements, effectively accumulates the 19 studied elements to 105 seawater concentrations. Mytilus galloprovincialis rapidly equilibrates (within days) with its environment, and is therefore a good indicator of chronic and stable chemical pollutions. Tissue speciation shows that the most relevant organ to monitor trace elements is the hepatopancreas. However, the important variability induced by the reproductive cycle of mussels requires using this bioindicator during its sexual dormancy. [less ▲]

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See detailDesign of reversibly disulfide core cross-linked polymer micelles
Cajot, Sébastien ULg; Schol, Daureen ULg; Danhier, F. et al

Poster (2011, December 07)

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See detailShallow heat injection and storage experiment monitored with electrical resistivity tomography and simulated with heat transport model
Hermans, Thomas ULg; Daoudi, Moubarak ULg; Vandenbohede, Alexander et al

Poster (2011, December 06)

Groundwater resources are increasingly used around the world as geothermal systems. Understanding physical processes and quantification of parameters determining heat transport in porous media is ... [more ▼]

Groundwater resources are increasingly used around the world as geothermal systems. Understanding physical processes and quantification of parameters determining heat transport in porous media is therefore important. To monitor the geothermal behavior of groundwater systems and to estimate the governing parameters, we rely mainly on borehole observations of the temperature field at a few locations (temperature logs or thermal response test). In analogy to research in hydrogeophysics, geophysical methods may be useful in order to yield additional information for thermal properties estimation with greater coverage than conventional wells. We report a heat transport study during a shallow heat injection and storage field test. Heated water (about 50°C) was injected for 6 days at the rate of 80 l/h in 10.5°C aquifer. Since bulk electrical resistivity variations can bring important information on temperature changes in aquifers (water electrical conductivity increases about 2%/°C around 25°C), we monitored the test with surface electrical resistivity tomography and demonstrate its ability to monitor spatially temperature variations. Time-lapse electrical image clearly show the decrease and then the increase in bulk electrical resistivity of the plume of heated water, during respectively the injection and the storage phase. This information enabled to calibrate the conceptual flow and heat model used to simulate the test (using SEAWAT). Inverted resistivity values are validated with borehole electromagnetic measurements (EM39) and are in agreement with the temperature logs used to calibrate the parameters of the thermo-hydrogeological model. This field work demonstrates that surface electrical resistivity tomography can monitor heat and storage experiments in shallow aquifers. These results could potentially lead to a number of practical applications, such as the monitoring or the design of shallow geothermal systems. Moreover, sensitivity analyses and collinear diagnostic were used to assess the pertinence of the flow and heat model parameters. The most sensitive parameter is the conductivity of the solid followed by the porosity, heat capacity of the solid and the longitudinal dispersivity. This indicates the predominance of conductive transport during the storage phase over the convective transport during the injection phase. These values rely only on temperature logs and more parameters could be derived or more robust values could be achieved with the use of geophysical data in a coupled inversion scheme. [less ▲]

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See detailModeling the potential for Eurasian Lynx (Lynx lynx) return in lowland Western Europe
Bouyer, Yaëlle ULg; Poncin, Pascal ULg; Beudels-Jamar, Roseline et al

Poster (2011, December 06)

In the last forty years, tolerance of anthropic environment has allowed large carnivores to recolonize and expand their distribution in Western Europe. To assess the full potential and consequences of ... [more ▼]

In the last forty years, tolerance of anthropic environment has allowed large carnivores to recolonize and expand their distribution in Western Europe. To assess the full potential and consequences of this return, habitat use and landscape modeling are particularly useful tools that allow conservationists to come up with reliable prediction, and policy makers to anticipate management planning. The considerable power of dispersal and important space requirements of these species necessitate large-scale modeling, but it is essential to work in parallel at very fine scale, as carnivores’ impact on human societies is mostly felt at local level. Management of large carnivores must therefore be multi-scalar, with different decisions taken at multiple levels. With the return of the Eurasian Lynx (Lynx lynx) to lowland Western Europe, in regions of relatively high human densities, conservation- planning decisions must be knowledge based. Different approaches will be followed to analyze data at finer and larger scales. These include differential distribution and tolerance of lynx to fragmentation and anthropization, influence of landscape on lynx predation and the development of a conceptual model aiming at responding efficiently to conflicts with human populations. Results will permit the development of a lowland Western Europe habitat model, and to propose conservation measures adapted to the return of this emblematic carnivore. Results will permit the development of a lowland Western Europe habitat model, and to propose conservation measures adapted to the return of this emblematic carnivore. [less ▲]

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See detailNew glucose-responsive polyelectrolyte microcapsules
Alaimo, David ULg; Detrembleur, Christophe ULg; Auzély-Velty, Rachel et al

Poster (2011, December 06)

Diabetes is a disorder of glucose regulation, characterized by an accumulation of glucose in the blood. The breakdown of glucose regulation can be attributed to the pancreas’s inability to secrete insulin ... [more ▼]

Diabetes is a disorder of glucose regulation, characterized by an accumulation of glucose in the blood. The breakdown of glucose regulation can be attributed to the pancreas’s inability to secrete insulin or to the body’s inability to properly use it. The usual treatment for type 1 diabetes consists in multiple subcutaneous insulin injections, daily administered using needles, insulin pen or insulin pump. However, this method doesn’t maintain normoglycemia and can lead to complications such as limb amputation, blindness, and kidney failure. To avoid such abnormal episodes, scientists imagined smart systems which are able to regulate the glucose level by themselves. During the past decades, a large variety of micro- and nanocarriers have been developed in order to improve efficiency, availability and toxicity profiles of drugs. In this field, stimuli-responsive polymer multilayers have attracted great scientific interest because of their potential applications as controlled delivery or release systems, for chemicals and drugs. A category of stimuli-responsive materials is able to sense glucose and respond to it by a modification of their porosity, leading to a release of insulin. The objective of this work was to investigate the formation of glucose responsive hollow microcapsules (5 microns) made of polyelectrolyte copolymers. These copolymers are composed of carbohydrate-sensitive functions, such as boronic acid and diols (PVOH), known for forming reversible covalent ether bond. In presence of carbohydrates such as glucose, the ether bonds will be reversibly broken and, consequently, the porosity of the glucose particles will change. Therefore, polyelectrolyte copolymers were synthesized by control radical polymerization, i.e. reversible addition-fragmentation chain transfer (RAFT, polyboronic acid) and cobalt-mediated radical polymerization (CMRP, PVOH). Using these polyelectrolytes as polyanions and poly(allylamine) (PAH) as a polycation, we undertook the formation of layer-by-layer capsules starting with a template of CaCO3microparticles which can be dissolved with EDTA leading to the formation of hollow microcapsules. Bovin serum albumin isothiocyanate (BSA-FITC) was used to fill the CaCO3microparticles and to determine the porosity of the resulting capsules in function of the glucose concentration. The sugar-dependent porosity is investigated by following the release of encapsulated BSA-FITC by spectro-fluoroscopy. [less ▲]

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See detailNUCLEAR DELIVERY OF A THERAPEUTIC PEPTIDE BY LONG CIRCULATING pH-SENSITIVE LIPOSOMES: BENEFITS OVER CLASSICAL VESICLES
Ducat, Emilie; Deprez, Juile; Noël, Agnès ULg et al

Poster (2011, December 06)

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See detailImmunoassay using a biofunctionnalized alumina-coated capacitive biosensor: towards a microfluidic detection of the H5N1 Influenza virus
van Overstraten-Schlogel, Nancy; Depuis, Pascal; Lefévre, Olivia et al

Poster (2011, December 02)

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See detailA Brain-Machine Interface with an Innovative Spiking Neural Network Decoder
Dethier, Julie ULg; Nuyujukian, Paul; Elassaad, Shauki A. et al

Poster (2011, December 02)

Motor prostheses aim to restore functions lost to neurological disease and injury by translating neural signals into control signals for prosthetic limbs. Despite compelling proof of concept systems ... [more ▼]

Motor prostheses aim to restore functions lost to neurological disease and injury by translating neural signals into control signals for prosthetic limbs. Despite compelling proof of concept systems, barriers to clinical translation—mainly strict power dissipation constraints—still remain. The proposed solution is to use the ultra-low-power neuromorphic approach to potentially meet these constraints. [less ▲]

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See detailEcological characterization of Lophira alata (Ekki), a vulnerable timber tree species, in order to develop silvicultural effective strategies
Biwole, Achille ULg; Doucet, Jean-Louis ULg

Poster (2011, December 02)

Ekki, Lophira alata Banks ex C.F.Gaertn., is an African timber species occurring in tropical rainforests. Of important commercial value, this species is logged for its excellent timber properties and has ... [more ▼]

Ekki, Lophira alata Banks ex C.F.Gaertn., is an African timber species occurring in tropical rainforests. Of important commercial value, this species is logged for its excellent timber properties and has been classified by the IUCN as «vulnerable" species. As for many other tropical tree species, the commercial exploitation of Ekki is confronted to an insufficient knowledge about the species’ ecological profile. With a distribution range limited to the Guinea-Congolian region, Ekki often displays insufficient natural regeneration, but the biotic and abiotic factors explaining this deficiency have been hardly characterized. This lack of knowledge makes it difficult to model the population dynamics on the long term. The reproductive biology of Ekki and the genetic variability of its population remains poorly studied too. To address this situation, a fundamental and applied research is being undertaken in the forest concessions managed by Wijma Cameroun SA., covering over 250,000 hectares of rainforest in Southern Cameroon. This study aims to answer four essential questions: (1) what is the phylogenetic relationship between L. alata and L. lanceolata, (2) how paleoclimate and human disturbances impact its distribution and abundance, (3) how to these populations respond to logging over several rotation periods, (4) does logging promote or inhibit the natural regeneration of the species. Several study devices have thus been installed to collect the data needed to improve the characterization of Ekki’s ecology and to conceive silvicultural strategies. [less ▲]

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See detailParameter Identification in a Model of the Cardiovascular System Including the Atria
Pironet, Antoine ULg; Revie, James A.; Paeme, Sabine ULg et al

Poster (2011, December 02)

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See detailMultiscale modeling of sprouting angiogenesis
Carlier, Aurélie ULg; Geris, Liesbet ULg; Van Oosterwyck, Hans

Poster (2011, December 02)

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See detailRole of western lowland gorilla (Gorilla gorilla gorilla) to dispersal and regeneration of commercial trees in South-East Cameroon
Petre, Charles-Albert ULg; Tagg, Nikki; Beudels-Jamar, Roseline et al

Poster (2011, December 01)

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See detailGeoelectrical monitoring on a contaminated site during biostimulation
Caterina, David ULg; Nguyen, Frédéric ULg

Poster (2011, December 01)

In Belgium, as in many other countries, relatively anarchic economical and industrial development of the past century has resulted in a significant number of contaminated sites. When one of these sites ... [more ▼]

In Belgium, as in many other countries, relatively anarchic economical and industrial development of the past century has resulted in a significant number of contaminated sites. When one of these sites poses a risk to human or ecosystem, measures need to be taken to clean it up. Among these measures, methods using in situ bioremediation are beginning to become more important because of their ease of implementation and their relatively low cost. However, it is often difficult to ensure their effectiveness except by carrying out extensive drilling and sampling, which can be long and expensive while offering only punctual information. Thus it becomes necessary to use other techniques to overcome these shortcomings. Recently, an increasing interest is being born to use geophysical methods as tools for remediation monitoring. As part of our work, we conducted several electrical resistivity tomography campaigns on a site contaminated by LNAPLs (gasoline) on which a biostimulation remediation device was set up. The aim of our investigations was to study the electrical response of the contaminated area during the remediation phase and whether electrical resistivity tomography allowed to monitor its effectiveness. After a year of monitoring, the time lapse images obtained show a significant decrease of the electrical resistivity (up to -50%) at the location of the main contaminant plume. This particular response during the biostimulation, in agreement with the models presented by several authors in the literature, tends to suggest that it is possible to use electrical resistivity tomography as a tool for qualitative control during the remediation. These findings may also lead in the future to the development of models to estimate more quantitatively the level of (de)contamination of a site. [less ▲]

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See detailMorphological and histological studies of sheep’s brain
Salouci, Moustafa ULg; Engelen, Virginie; Jacqmot, Olivier ULg et al

Poster (2011, December)

Introduction: The study of normal structures of the sheep’s brain is very important to understand pathological changes caused by the bluetongue virus in the fetus’s brain at various stages of the ... [more ▼]

Introduction: The study of normal structures of the sheep’s brain is very important to understand pathological changes caused by the bluetongue virus in the fetus’s brain at various stages of the gestation. Bluetongue is an arthropod-borne viral disease of domestic and wild ruminants. The serotype 8 is responsible for outbreaks in Northern Europe in 2006. This virus causes lesions in the brain of fetuses as hydrancephaly and porencephaly. The aim of this work is to improve knowledge of anatomy and histology of the central nervous system of the sheep. Methods: Seven heads of adult sheep and one from a fetus aged 4,5 months were used. All heads were first opened in the frontal area using bone’s saw and immerged in a formalin solution for 10 days. After a good fixation, the brains were extracted and sectioned. Transversal, frontal and sagittal sections were realized. The sections of two brains were stained with Berlin-blue and treated to be embedded in methylmetacrylate for gross morphology. The different parts of the 6 resting brains were then embedded in paraffin, cut and the histological sections were stained with haematoxylin/eosin, cresyl violet or by use of silver impregnation. Results: Gross morphological examination of the brains embedded in methylmetacrylate showed the detailed anatomy of the different parts. The staining with haematoxylin/eosin permitted to differentiate the grey matter, the different nucleus and the layers of cerebral and cerebellum cortex. The cresyl violet technique permitted to visualize the Nissl bodies and the silver impregnation revealed nerve fibers. In the fetus brain, blood vessels were very numerous in the brainstem, the cerebellum and the cerebrum. The grey matter was less organized and looser. Conclusion: This work establishes an anatomical and histological approach allowing future studies in ovine fetuses with and without brain lesions potentially caused by the bluetongue virus. [less ▲]

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See detailInfluence des traitements de steam explosion sur la dégradation thermique des fibres de cellulose
Jacquet, Nicolas ULg; Quievy; Vanderghem, Caroline ULg et al

Poster (2011, December)

La présente étude a pour but d’identifier l’impact de différents traitements de steam explosion sur les propriétés de dégradation thermique des fibres de cellulose. Dans un premier temps, les intensités ... [more ▼]

La présente étude a pour but d’identifier l’impact de différents traitements de steam explosion sur les propriétés de dégradation thermique des fibres de cellulose. Dans un premier temps, les intensités des traitements appliqués ont été définies sur base d’un facteur de sévérité (SF), établi par une corrélation entre le temps de séjour et la température du process. Les résultats obtenus montrent que la dégradation thermique des fibres de cellulose reste limitée lorsque la valeur du facteur de sévérité est inférieure à 4.0. Aux intensités supérieures, le dosage des produits de dégradation montre une croissante importante des concentrations en hydroxyméthylfurfurals (5-HMF) dans les phases liquides issues des différents traitements. Lorsque la valeur du facteur de sévérité dépasse 5.2, les analyses TGA indiquent que l’augmentation des produits de dégradation est couplée à une croissance importante du taux de résidus carbonés, indiquant une forte dégradation thermique de la cellulose [less ▲]

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See detailEffects of hydrogen partial pressure on fermentative biohydrogen production by a chemotropic Clostridium bacterium in a new horizontal rotating cylinder reactor
Beckers, Laurent ULg; Hiligsmann, Serge ULg; Hamilton, Christopher ULg et al

Poster (2011, December)

The fermentative production of hydrogen using chemotrophic anaerobic bacteria offers a new way to produce “green” energy from a large variety of renewable resources and organic wastes. In order to produce ... [more ▼]

The fermentative production of hydrogen using chemotrophic anaerobic bacteria offers a new way to produce “green” energy from a large variety of renewable resources and organic wastes. In order to produce hydrogen at high yields and production rates, efficient bioreactors must be designed. A new reactor called “horizontal rotating cylinder bioreactor” allows the production of biohydrogen from glucose with the selected Clostridium sp. strain at high yields (1,9molH2·molglucose-1) and production rates (48,6mmolH2·lmilieu-1.molhexose-1·h-1). The rotative cylinder where the bacteria are fixed enables efficient gas transfer (mainly hydrogen) from the liquid phase where it is produced by the bacteria. This is an important way to allow the bacteria metabolism to shift in a fermentation pathway that produces more hydrogen. This was confirmed by varying the total pressure in the bioreactor. An increase of the total pressure 0,18bar lowered the yields of 19,5% while a decrease of 0,11bar increased the yields of 7%. Our work concludes the importance of providing good liquid to gas transfers in the biohydrogen-producing reactors in order to reach higher yields and production rates. [less ▲]

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See detailRecherche de nouveaux biomarqueurs des cancers épithéliaux de l’ovaire par imagerie MALDI.
Boyon, Charlotte; Longuespée, Rémi ULg; Kerdraon, Olivier et al

Poster (2011, December)

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See detailStructural model of the mitral valve included in a cardiovascular closed loop model
Paeme, Sabine ULg; Moorhead, Kate; Chase, J. Geoffrey et al

Poster (2011, December)

A minimal cardiovascular system (CVS) model including mitral valve dynamics has been previously validated in silico. However parameters of this model are difficult to link with structural and anatomical ... [more ▼]

A minimal cardiovascular system (CVS) model including mitral valve dynamics has been previously validated in silico. However parameters of this model are difficult to link with structural and anatomical components of the valve. This research describes the integration of a structural model of the mitral valve in an existing closed-loop cardiovascular system (CVS) model [less ▲]

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See detailGlycemic Variability, Hypoglycemia and Organ Failure in the Glucontrol Study
Penning, Sophie ULg; Le Compte, Aaron J.; PREISER, Jean-Charles ULg et al

Poster (2011, December)

Detailed reference viewed: 27 (7 ULg)
See detailNightglow investigation in the Visible Range with the VIRTIS/Venus-Express instrument
Migliorini, A.; Slanger, T.; Saran, D. et al

Poster (2011, December)

In this study we report the investigation of the nightglow molecular oxygen emissions of Venus in the visible spectral range, observed by the VIRTIS instrument (Visible and InfraRed Spectral Imaging ... [more ▼]

In this study we report the investigation of the nightglow molecular oxygen emissions of Venus in the visible spectral range, observed by the VIRTIS instrument (Visible and InfraRed Spectral Imaging Spectrometer) on board the Venus Express spacecraft. The Herzberg II system was detected in the range 0.4-0.7 µm. The observed bands peak at 95-96 km altitude, with a limb mode intensity of 15-20 kR for the strongest band, similar to that seen in previous observations. Simultaneous observations in the visible and IR [O2 (a-X) 1.27 µm band] were obtained in March 2007, and the two systems are similar in peak altitude. In addition, three bands of the O2 Chamberlain system, at 0.558, 0.604, and 0.657 µm were detected. They are well detached from the Herzberg II bands, and more distinct than reported in previous observations (Garcia Munoz et al., 2009). A simulated spectrum is obtained using the DIATOM code, allowing accurate reproduction of the observed VIRTIS mean spectrum. [less ▲]

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See detailShallow open-loop geothermal systems: simulation of heat transport in groundwater and experimental tests for improving parameterization
Fossoul, Frédérique; Orban, Philippe ULg; Dassargues, Alain ULg

Poster (2011, December)

Innovative and efficient strategies for energy utilization become a priority, especially in the civil engineering sector. Geothermal open-loop systems (geothermal wells) are not so developed in Belgium ... [more ▼]

Innovative and efficient strategies for energy utilization become a priority, especially in the civil engineering sector. Geothermal open-loop systems (geothermal wells) are not so developed in Belgium contrary to close-loop systems. This is generally due to the lack of relevant dimensioning and impact study that must be foreseen during the planning phases of the building. However, as shallow groundwater is widely available, geothermal wells potential is significant. Using both experimental and numerical tools, our aim is to develop a rigorous methodology to design heating and cooling shallow geothermal wells (pumping/reinjection), with a detailed hydrogeological characterization, coupled to feasibility, environmental impact assessment, dimensioning and system sustainability. Groundwater flow and heat transport is computed using different numerical codes (HydroGeoSphere, MT3DMS and SHEMAT) for a comparative sensitivity analysis on a typical case. Coupling and temperature non linearities of the hydro-thermal parameters values are checked accurately. As shown previously, small temperature variations, allow to use conventional solute transport codes modeling heat transport in groundwater taking benefits of the similarities between solute and heat transport equations. When numerical codes are used as dimensioning tools for long-term simulations, reliable values for hydro-thermal properties of the aquifer are essential. Very few experimental values are available in the literature. Field experiments are needed to determine more accurately the local values in different geological/hydrogeological conditions. Apart from thermal response tests (TRT) usually performed for designing a close-loop system within a borehole considered in static groundwater conditions, there is no standard procedure for geothermal wells systems. In an open groundwater system, groundwater movement induced by the pumping (convection) is a major heat transport process and cannot be neglected. A pilote site is currently studied for optimizing methods in such low temperature geothermal systems. The field experiments include: pumping tests (for hydraulic conductivities to be used for dimensioning tracer and heat tracing tests), solute tracer tests, heat tracing tests. Hot water injection, is combined with downstream pumping and intermediate temperature and pressure monitoring piezometers for detection of the heat plume shape. Natural temperature variations, due to air temperature day/night and interseasonal cycles and also induced by the river proximity, are filtered. The test characteristics and first results are detailed showing that the combined use of solute tracer tests and heat tracing tests leads to a better characterization of the local hydro-thermal properties. [less ▲]

Detailed reference viewed: 42 (2 ULg)
See detailContribution à l’identification des domaines impliqués dans l’activité anti- influenza des protéines « Mx »
Heinen, Marie-Pierre ULg; Cornet, Anne; Willems, Jérôme ULg et al

Poster (2011, December)

Les protéines Mx sont des GTPases formant une classe distincte dans la superfamille des dynamines. Elles sont induites par des interférons et sont le résultat du produit de deux à trois gènes distincts ... [more ▼]

Les protéines Mx sont des GTPases formant une classe distincte dans la superfamille des dynamines. Elles sont induites par des interférons et sont le résultat du produit de deux à trois gènes distincts selon l’espèce. Structurellement, on peut les subdiviser en trois domaines majeurs, le domaine GTPase N-terminal (G domain), un domaine intermédiaire (MD) et le domaine effecteur GTPase C-terminal (GED). Face à l’influenza, certaines isoformes (Homo sapiens, Mus musculus, Rattus norvegicus, Sus scrofa et Bos taurus) exercent une activité anti-virale significative alors que, malgré une identité de séquence, d’autres isoformes (Gallus gallus, Anas platyrhynchos) n’ont pas d’activité anti-virale reconnue à ce jour. Bien que la connaissance des mécanismes impliqués dans leurs effets anti-viraux reste très limitée, nous savons que la liaison au GTP est indispensable (G Domain) et qu’une partie du potentiel antiviral résulte de leur capacité à se lier avec des protéines virales ou cellulaires entraînant l’inhibition du cycle viral (MD et GED). D’ailleurs, des mutations ponctuelles et des délétions dans ces derniers domaines sont connues pour abolir l’activité antivirale de la protéine. Le projet de recherche entamé ici consiste à produire un jeu de chimères entre une protéine Mx dépourvue d’activité anti-influenza (la protéine aviaire) et une protéine Mx très active contre les virus influenza (la protéine bovine) dans le but d’identifier le support structural minimum sous-jacent à l’activité anti-influenza des protéines Mx en général. Le projet en cours consiste à produire un jeu de cellules véro inductible capable de produire conditionnellement, les chimères précitées. [less ▲]

Detailed reference viewed: 71 (20 ULg)
Peer Reviewed
See detailAdsorption of methylene blue on activated carbon xerogels
Páez Martínez, Carlos ULg; Contreras, Maria Soledad; Léonard, Angélique ULg et al

Poster (2011, November 30)

Detailed reference viewed: 55 (11 ULg)
Full Text
See detailPruning randomized trees with L1-norm regularization
Joly, Arnaud ULg; Schnitzler, François ULg; Geurts, Pierre ULg et al

Poster (2011, November 29)

Growing amount of high dimensional data requires robust analysis techniques. Tree-based ensemble methods provide such accurate supervised learning models. However, the model complexity can become utterly ... [more ▼]

Growing amount of high dimensional data requires robust analysis techniques. Tree-based ensemble methods provide such accurate supervised learning models. However, the model complexity can become utterly huge depending on the dimension of the dataset. Here we propose a method to compress such ensemble using random tree induced space and L1-norm regularisation. This leads to a drastic pruning, preserving or improving the model accuracy. Moreover, our approach increases robustness with respect to the selection of complexity parameters. [less ▲]

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See detailInfluence du stockage des boues de STEP sur les émissions de NH3 et de COV durant leur séchage
Fraikin, Laurent ULg; Salmon, Thierry ULg; Herbreteau, Benjamin et al

Poster (2011, November 29)

Le séchage constitue une étape importante en aval de la déshydratation mécanique en vue de la valorisation agricole ou énergétique des boues de station d’épuration. La teneur en eau peut être réduite à ... [more ▼]

Le séchage constitue une étape importante en aval de la déshydratation mécanique en vue de la valorisation agricole ou énergétique des boues de station d’épuration. La teneur en eau peut être réduite à moins de 5%, diminuant ainsi la masse et le volume des boues et, par conséquent, le coût pour le stockage, la manutention et le transport. L'élimination de l'eau augmente considérablement le pouvoir calorifique inférieur, transformant les boues en un combustible convenable. En outre, les boues séchées peuvent être stabilisées et exemptes d'agents pathogènes en fonction de la température et de la durée de traitement. Les technologies convectives sont largement utilisées pour le séchage des boues. Le principal avantage est la simplicité de la technologie et l’inconvénient majeur résulte de la grande quantité d'air à épurer et désodoriser. Le but des travaux menés par l'Université de Liège et VEOLIA Environnement est d'effectuer une caractérisation en laboratoire des émissions gazeuses en fonction des conditions de séchage. Pour ce faire, il est primordial de garantir une qualité constante de l'échantillon initial tout au long des mesures. En effet, même si elles sont conservées à basse température, les boues peuvent être le siège de dégradations biologiques et les propriétés de séchage peuvent être modifiées. Ainsi, la première partie de ce travail est consacrée à l’étude de l'influence de la durée de stockage des boues à 4°C sur les émissions gazeuses produites au cours de leur séchage convectif. Deux types de boues, l’une ayant subi une digestion et l’autre pas, sont étudiés. L’échantillonnage est effectué après la déshydratation mécanique dans deux stations de traitement des eaux usées situées à proximité de l'Université de Liège. Les échantillons sont stockés dans le laboratoire à 4°C dans un récipient hermétique. Pour effectuer les essais, 300 g de boue sont déposés dans le sécheur sous la forme d’un lit d'extrudés de 6 mm de diamètre. La masse de boue, la concentration en ammoniac et la concentration en composés organiques volatils sont mesurées en ligne respectivement par une balance, un analyseur infrarouge et un détecteur à ionisation de flamme. Des thermocouples permettent le suivi de la température en amont, au sein et en aval du lit de boue. Des essais de séchage sont effectués au jour 0 (= jour du prélèvement), et après 1, 2, 4, 10, 17 et 20 jours sous les conditions suivantes : température de l'air = 140°C; vitesse superficielle de l'air = 1 m/s; humidité absolue = 0,005 kgeau/kgair sec. La seconde partie du travail a été réalisée sur un échantillon de boue non digérée conservé à 12°C pour simuler des conditions réelles de stockage. Les essais de séchage ont été menés le jour de prélèvement et après 4, 10 et 20 jours, avec des conditions opératoires similaires. L’étude réalisée avec un stockage à 4°C montre que les émissions gazeuses sont maximales le jour du prélèvement, diminuent fortement durant les deux premiers jours de stockage pour atteindre un niveau constant durant deux semaines avant d’augmenter. Lors du stockage à 12°C, les émissions d’ammoniac et de COV sont multipliées respectivement par un facteur 40 et 4 entre le jour 0 et le jour 20. Ces résultats mettent en évidence l’impact des conditions et de la durée de stockage sur les émissions lors du séchage des boues et montrent l’importance de sécher les boues le plus rapidement possible pour limiter les nuisances. [less ▲]

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Peer Reviewed
See detailCaractérisation microstructurale de mousses polymères nanocomposites par microtomographie à rayons X
Plougonven, Erwan ULg; Tran, Minh Phuong ULg; Marchot, Pierre ULg et al

Poster (2011, November 29)

Les circuits électriques, fonctionnant à des fréquences de plus en plus élevées, sont responsables de l’augmentation de la pollution électromagnétique, et justifient le développement de blindages ... [more ▼]

Les circuits électriques, fonctionnant à des fréquences de plus en plus élevées, sont responsables de l’augmentation de la pollution électromagnétique, et justifient le développement de blindages efficaces. De nombreuses applications sont concernées, que ce soit dans les systèmes électroniques commerciaux, industriels, ou militaires, ou les systèmes antennaires. Récemment, des blindages sous forme de composites polymère/charges carbonées ont été largement développés pour leur nombreux avantages : plus légers, moins chers, plus absorbants, et plus facilement moulables. Une charge carbonée prometteuse est le nanotube de carbone car de par son facteur de forme, une concentration moindre est nécessaire pour une conductivité équivalente [1]. Afin d’améliorer l’absorption de l’énergie électromagnétique de ces composites (par rapport à leur réflectivité), ils sont moussés pour réduire leur constante diélectrique. Cette étape de moussage doit être rigoureusement contrôlée pour atteindre le niveau d’absorption ciblé. Deux techniques de moussage sont envisagées dans cette étude, à savoir le moussage en CO2 supercritique (par imprégnation de CO2 en condition supercritique, avant une dépressurisation rapide) et le freeze-drying (dissolution dans un solvant, suivi d’une lyophilisation de celui-ci). Ces deux méthodes génèrent des structures de porosité bien distinctes, avec une anisotropie apparente marquée dans le second cas. L’objectif est de caractériser ces structures par tailles moyennes de pores et mesures d’anisotropie, et leur lien avec l’efficacité de blindage. Dans cette optique, la caractérisation est effectuée par microtomographie à rayons X, une technique d’imagerie 3D non-destructive. Des acquisitions sont faites sur chaque échantillon, et la microstructure est analysée par traitement d’images. Vu la très faible atténuation des rayons X dans ce type de matériaux, et la limite de résolution de cette technique par rapport à la taille des pores et à l’épaisseur des parois, la séparation précise des pores par rapport à la matrice polymère s’avère difficile. Une segmentation classique n’étant pas applicable en préalable à des mesures quantitatives, la fonction d’autocorrélation est utilisée. Cette technique, habituellement utilisée en traitement du signal, est une méthode performante de mesure globale de l’anisotropie d’un matériau [2]. Elle permet également d’extraire une longueur caractéristique qui peut être liée à la taille des cellules. Les résultats mettent en évidence l’impact de la technique et des conditions de moussage sur la microstructure des mousses composites. [less ▲]

Detailed reference viewed: 149 (34 ULg)
See detailA Brain-Machine Interface Operating with a Real-Time Spiking Neural Network Control Algorithm
Dethier, Julie ULg; Nuyujukian, Paul; Elassaad, Shauki A. et al

Poster (2011, November 29)

Motor prostheses aim to restore function to disabled patients. Despite compelling proof of concept systems, barriers to clinical translation remain. One challenge is to develop a low-power, fully ... [more ▼]

Motor prostheses aim to restore function to disabled patients. Despite compelling proof of concept systems, barriers to clinical translation remain. One challenge is to develop a low-power, fully-implantable system that dissipates only minimal power so as not to damage tissue. To this end, we implemented a Kalman-filter based decoder via a spiking neural network (SNN) and tested it in brain-machine interface (BMI) experiments with a rhesus monkey. The Kalman filter was trained to predict the arm’s velocity and mapped on to the SNN using the Neural Engineering Framework (NEF). A 2,000-neuron embedded Matlab SNN implementation runs in real-time and its closed-loop performance is quite comparable to that of the standard Kalman filter. The success of this closed-loop decoder holds promise for hardware SNN implementations of statistical signal processing algorithms on neuromorphic chips, which may offer power savings necessary to overcome a major obstacle to the successful clinical translation of neural motor prostheses. [less ▲]

Detailed reference viewed: 38 (12 ULg)
See detailDevelopment of electrospun chitosan scaffold for wound dressing application
Aqil, Abdelhafid ULg; Tchemtchoua, Victor; Colige, Alain ULg et al

Poster (2011, November 28)

Wound dressing is one of the most promising medical applications for chitosan, due to its adhesive nature, together with some biological properties including bacteriostatic and fungistatic properties that ... [more ▼]

Wound dressing is one of the most promising medical applications for chitosan, due to its adhesive nature, together with some biological properties including bacteriostatic and fungistatic properties that help in faster wound healing. In this work we propose a chitosan biomimetic scaffolds and methods for modulating their intrinsic properties such as rigidity, elasticity, resistance to mechanical stress, porosity, biodegradation and absorbance of exudates. Therefore, the chitosan scaffold comprising at least two fused layers, wherein the advantage of a first fused layer composed of a chitosan electrospun nanofiber membrane are oxygen-permeability, high porosity, variable pore-size distribution, high surface to volume ratio, and most importantly, morphological similarity to natural extracellular matrix in skin, which promote cell adhesion migration and proliferation. The advantages of a second fused layer comprising a porous chitosan support layer are improving mechanical property, good absorption capacities to remove excess exudates and good water and gas exchange. Moreover, the scaffold was characterized by (i) a good adhesion between the porous and nanofiber layers, (ii) a tuneable porosity of the nanofiber layer by tuning the distance between the nanofibers, (iii) a stable nanofibers and porous morphology even when immersed in water. Finally, the scaffolds have shown tremendous promise as a wound dressing, in tissue engineering. The three main human cell types fibroblasts, endothelial cells and keratinocytes was cultured in vitro on electrospun nanofibers scaffold. Properties of electrospun chitosan scaffold and chitosan sponges obtained by lyophilization were also compared in vivo, in order to evaluate importance of the 3D-architecture of the biomaterial. [less ▲]

Detailed reference viewed: 54 (3 ULg)
See detailCommunication du médecin centrée sur le patient: Intérêt pour l'équipe pluridisciplinaire
Jonius, Bénédicte ULg

Poster (2011, November 25)

INTRODUCTION. Deux types de communication existent entre les médecins et les patients. La première, traditionnelle, s’appelle la communication centrée sur le médecin. La seconde, plus récente, s’intitule ... [more ▼]

INTRODUCTION. Deux types de communication existent entre les médecins et les patients. La première, traditionnelle, s’appelle la communication centrée sur le médecin. La seconde, plus récente, s’intitule la communication centrée sur le patient. Dans ce type de communication, les médecins adoptent des comportements qui favorisent notamment l’expression du patient. C’est pourquoi, nous nous sommes interrogés sur l’intérêt d’une telle communication en oncologie, tant du point de vue du patient que de celui des membres des équipes pluridisciplinaires. METHODOLOGIE. Dans une étude antérieure, une formation de base à la communication a été donnée à 63 médecins ; cette formation se définissait en termes de stratégies d’évaluation de l’état psychologique du patient mais également en termes de stratégies de soutien vis-à-vis du patient. Pour alimenter notre discussion sur la pertinence de former des médecins à une communication centrée sur le patient, nous avons retenu, d’une part, l’indice de Karnofsky (caractéristique physique du patient), et d’autre part, les scores de dépression, d’anxiété, de détresse et de qualité de vie (QV) (caractéristiques psychologiques du patient). Le principal outil écologique utilisé est l’Inventaire Systémique de Qualité de Vie (ISQV-©). RESULTATS. Avant la formation de base à la communication, il n’y a aucune corrélation significative entre les compétences de communication du médecin (évaluation et soutien) et les caractéristiques du patient (physique et psychologiques). Après la formation à la communication, deux corrélations sont significatives : les médecins utilisent davantage de stratégies d’évaluation avec les patients dont l’état actuel (en termes de QV) est médiocre et avec les patients dont le but idéal est trop éloigné de leur état actuel. CONCLUSION. Ces résultats tendent à montrer que les corrélations obtenues entre les compétences d’évaluation des médecins et les scores d’état et de but du score de QV des patients sont davantage le reflet d’une communication centrée sur le patient. Ainsi, à l’intérieur d’un entretien médical (l’annonce d’un diagnostic), des affects d’ordre psychologique ont pu émerger. La question qui se pose alors en équipe pluridisciplinaire est de réfléchir à l’exploitation de ces nouvelles données : que fait-on de ce matériel psychologique, qui s’en occupe et comment ? Il s’agit là des prémisses d’une communication transdisciplinaire. [less ▲]

Detailed reference viewed: 71 (5 ULg)
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See detailNuclear Magnetic Resonance and Nuclear Waste Reprocessing.
Vidick, Geoffrey ULg; Bouslimani, Nouri; Desreux, Jean-François ULg

Poster (2011, November 22)

Detailed reference viewed: 27 (3 ULg)
See detailDesign of reversibly disulfide core cross-linked polymer micelles
Cajot, Sébastien ULg; Schol, Daureen ULg; Danhier, F. et al

Poster (2011, November 21)

Over the last decade, polymer micelles attracted an increasing interest in drug pharmaceutical research because they could be used as efficient drug delivery systems. Micelles of amphiphilic block ... [more ▼]

Over the last decade, polymer micelles attracted an increasing interest in drug pharmaceutical research because they could be used as efficient drug delivery systems. Micelles of amphiphilic block copolymers are supramolecular core-shell type assemblies of tens of nanometers in diameter. An accumulation of polymer nanocarriers to solid tumours is possible due to the EPR effect. Even if micelles get a high stability in aqueous media, the dissociation of micelles is not always preserved when they are injected in the blood compartment. This work aims at reporting on the design of reversibly cross-linked micelles based on PEO-b-PCL copolymers by introducing disulfide bridges in the micelle core to provide higher stability. Different kinds of macromolecular architectures are employed to study their impact on the micelles and their biological behavior. These new functional copolymers were all successfully micellized, reversibly cross-linked and are stealthy, which show the efficiency of the developed cross-linking process and offer a set of nanocarriers to be tested further, as shown on the first biological tests. [less ▲]

Detailed reference viewed: 84 (6 ULg)
See detailChitosan-based nanofibers with multilayered structure for wound healing application
Croisier, Florence ULg; Detrembleur, Christophe ULg; Jérôme, Christine ULg

Poster (2011, November 21)

Chitosan is a natural polymer that intrinsically presents haemostatic, mucoadhesive, antimicrobial and immunostimulant properties. This polysaccharide has shown a great potential for biomedical ... [more ▼]

Chitosan is a natural polymer that intrinsically presents haemostatic, mucoadhesive, antimicrobial and immunostimulant properties. This polysaccharide has shown a great potential for biomedical applications, on account of its remarkable compatibility with physiological medium and its biodegradability. 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) and can be used as 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 for wound healing application. [less ▲]

Detailed reference viewed: 135 (10 ULg)
See detailStabilization of gold nanoparticles by thermo-responsive poly (vinyl alcohol)-b-poly (N-vinylcaprolactam) copolymers
Liu, Ji ULg; Hurtgen, Marie ULg; Detrembleur, Christophe ULg et al

Poster (2011, November 21)

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

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

Detailed reference viewed: 145 (11 ULg)
See detailSmart block copolymers for biomedical applications
Sibret, Pierre ULg; De Pauw-Gillet, Marie-Claire ULg; Jérôme, Christine ULg

Poster (2011, November 21)

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

Smart polymers are polymers that respond with rapid changes to external stimuli such as pH, temperature, light or ionic strength. Responses to the stimuli may manifest themselves as changes in solubility, shape or surface characteristics. These materials are very intersesting for different biomedical applications such as drug delivery systems, tissue engineering or sensors. In this work, we focused on two separate systems: on the one hand, micelles and, on the other hand, iron oxide nanoparticles. These nanoparticles are generally synthesized in a one-step process by alkaline coprecipitation of iron (II) and iron (III) precursors. However, iron oxide nanoparticles are not stable enough in physiological conditions to be used as is. A stabiliser coating is needed to avoid aggregation and precipitation of the colloids in body fluids. For this coating, the polymer blocks chosen are PEO (to confer stealthiness), PAA (pH-responsive) and PNIPAM (thermoresponsive). This triblock copolymer was synthesized by RAFT polymerization and was used alone to form micelles and with iron oxide to make magnetic stabilized nanoparticles. The behaviour of micelles and coated nanoparticles was investigated by a combination of DLS, TEM and zeta potential measurements. To highlight the potentiality of these nanomaterials, their cytotoxicity will be studied and compared. [less ▲]

Detailed reference viewed: 116 (3 ULg)
Full Text
See detailCombination of lipase catalysis and thiol-Michael addition for the synthesis of carbohydrate esters used as stabilizers in supercritical carbon dioxide emulsions
Boyère, Cédric ULg; Favrelle, Audrey; Broze, Guy ULg et al

Poster (2011, November 21)

The use of aqueous dispersed media, such as emulsions and miniemulsions, has many advantages over solution processes for chemical transformations and polymerization reactions, i.e. limited environmental ... [more ▼]

The use of aqueous dispersed media, such as emulsions and miniemulsions, has many advantages over solution processes for chemical transformations and polymerization reactions, i.e. limited environmental impact, ease of products recovery and increased reaction rate. Although, dispersed media are usually implemented from water/solvent mixtures, supercritical carbon dioxide (scCO2) (Pc =74 bars; Tc = 31°C) constitutes an interesting alternative to the traditional organic solvents because it is inexpensive, non-toxic, non-flammable and environmentally friendlier. In this context, we develop a novel class of surface active compounds able to stabilize water/scCO2 emulsions, i.e. fluorinated modified carbohydrates. The hydrophilic head of the surfactant consists in a sugar moiety whereas the fluorinated tail has a strong affinity for the scCO2 phase. These carbohydrate esters are prepared by a two-step strategy which takes advantage of the selectivity of enzymatic catalysis and the versatility of the thiol-Michael addition reaction. The new thiolated mannose intermediate is a useful building block for the incorporation of unprotected sugar moieties into complex molecules. The surface active properties of the fluorinated derivatives have been evaluated as well as their use as stabilizers for the preparation of microparticles and highly porous polymer materials in scCO2. [less ▲]

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See detailEvaluation de la diversité bactérienne et de son évolution pendant la conservation de la viande fraîche bovine de différentes origines emballée sous vide
Didimo Imazaki, Pedro Henrique ULg; Maréchal, Aline; Nezer, Carine ULg et al

Poster (2011, November 18)

Un grand nombre de bactéries lactiques associées à la viande sont connues comme d'importants producteurs de bactériocines. Ces bactériocines sont des toxines protéiques présentant une activité bactéricide ... [more ▼]

Un grand nombre de bactéries lactiques associées à la viande sont connues comme d'importants producteurs de bactériocines. Ces bactériocines sont des toxines protéiques présentant une activité bactéricide ou bactériostatique contre des espèces proches de la souche productrice. La présence de certaines bactéries lactiques dans la viande fraîche pourrait donc prolonger la durée de conservation, et améliorer la stabilité microbienne et la sécurité de ce produit. Dans ce contexte, une étude a été réalisée sur des échantillons de contre-filet de différentes origines emballés sous vide, dans le but d’évaluer la diversité bactérienne et son évolution pendant la conservation. L’étude a été réalisée sur trois lots provenant d’Irlande, du Brésil et d’Australie, affichant respectivement une DLC de 35 jours, 120 jours et 140 jours. Après réception dans le laboratoire, les échantillons ont été conservés à 1 °C. Ensuite, pendant le dernier tiers de leur DLC, ils ont été conservés à 1 °C ou à +4 °C. Des dénombrements ont été réalisés : 1) aux ⅔ de la DLC et 2) à la fin de la DLC. Les germes dénombrés ont été : la flore aérobie totale à +22 °C, la flore lactique à +22 °C et les Enterobacteriaceae à +30 °C en utilisant le système automatique de dénombrement TEMPO®. Tous les échantillons conservés à 1 °C ont présenté une qualité microbiologique satisfaisante à la fin de la conservation. Par contre, la conservation à +4 °C a favorisé une croissance plus importante des bactéries lactiques et des Enterobacteriaceae. Dans le cas des Enterobacteriaceae, le seuil défini pour évaluer l’acceptabilité des différents lots a été dépassé. Les dénombrements ont permis de caractériser la dynamique de croissance des populations bactériennes, mais n’ont donné que très peu d’information sur la diversité bactérienne des échantillons. Dans le but de caractériser celle-ci, une étude métagénomique a été réalisée. Ce champ relativement nouveau de la génétique permet d'étudier les communautés de microorganismes dans leur environnement naturel, en contournant la nécessité de culture et isolement en laboratoire. Les résultats préliminaires révèlent qu’aux ⅔ de la DLC, Aquabacterium était le genre dominant dans les lots d’origines irlandaise et brésilienne, Pseudomonas était le genre dominant dans le lot d’origine australienne. A la fin de la DLC (après conservation à +4 °C), Aquabacterium et Escherichia étaient les genres dominants dans le lot d’origine irlandaise. L’ordre Lactobacillales était le plus abondant dans les lots d’origines brésilienne et australienne. Les différences dans la composition de la population bactérienne de la viande, en particulier en ce qui concerne les bactéries lactiques, pourraient expliquer les longues DLC appliquées dans certains pays. Ces recherches doivent être poursuivies pour identifier les populations bactériennes (et leur source) présentes dans ces viandes et pour étudier leur dynamique au cours de la conservation. [less ▲]

Detailed reference viewed: 182 (42 ULg)
Peer Reviewed
See detailCalcium phosphate scaffolds customizations for bone tissue engineering applications
Carlier, Aurélie ULg; Chai, Yoke Chin; Theys, Tina et al

Poster (2011, November 18)

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See detailInvestigations on the mechanisms underlying the thymotropic properties of the growth hormone (GH)/insulin-like growth factor 1 (IGF-1) axis.
Goffinet, Lindsay ULg; Bodart, Gwennaëlle ULg; Renard, Chantal et al

Poster (2011, November 18)

Background. The thymus is responsible for thymopoiesis, i.e. the generation of a diverse and self-tolerant T-cell repertoire including self-antigen specific natural regulatory cells. We have shown that ... [more ▼]

Background. The thymus is responsible for thymopoiesis, i.e. the generation of a diverse and self-tolerant T-cell repertoire including self-antigen specific natural regulatory cells. We have shown that two parameters of thymopoiesis, thymic output of new T cells (estimated by sjTREC frequency) and intrathymic proliferation of T-cell precursors (estimated by sj/Dβ TREC ratio) are severely reduced in adult patients with GH deficiency (AGHD) and are restored by GH injections at physiological doses. In patients with AGHD, there is a very positive correlation between sjTREC frequency and plasma concentrations of IGF-1, the principal mediator of GH action (1). Treatment of HIV+ patients with high pharmacological doses of GH is associated with increased thymic mass and output of circulating naïve and total CD4+ T cells (2). In addition, previous studies have suggested thymic epithelial cells (TEC) and/or thymocytes (thymic T cells) could transcribe the GH gene (3). Objectives and hypothesis. These studies analysed the question of GH transcription and regulation in primary cultures of human (h) TEC. We also investigated the hypothesis that the thymotropic properties of the somatotrope GH/IGF-1 axis could be mediated by thymic interleukin 7 (IL-7), which plays a crucial role in promoting V(D)J recombination at the TCR locus. Results. Primary hTEC cultures were treated with natural secretagogues of pituitary GH, GH releasing hormone (GHRH) and ghrelin. Using sensitive RT-qPCR, we detected neither any transcript of GH or GHV (placental GH variant) in cultured hTEC, nor any transcript of PIT1, the specific transcription factor of pituitary GH. Similarly, the protein GH was detected neither in the cytoplasm nor in the supernatant of cultured hTEC. Only at 1 nM, GH treatment enhanced IGF1 transcription by cultured hTEC. Of high interest, treatment with GH, ghrelin and IGF-1 promoted IL7 transcription by cultured hTEC, but only IGF-1 and epidermal growth factor (EGF) markedly stimulated IL-7 secretion by hTEC in a dose- and time-dependent manner. The specificity of IGF-1 action was demonstrated by its inhibition after treatment with αIR3, a monoclonal antibody against the type 1 IGF receptor. Conclusions and perspectives. Since primary cultures of hTEC neither transcribe nor secrete any significant amount of GH, the thymotropic effects of the GH/IGF-1 axis seem to depend only on systemic endocrine GH. Local thymic IGF-1 could partially mediate GH action within the thymus and act upon thymopoiesis in parallel with systemic IGF-1. Most importantly, thymic IL-7 appears to be an important mediator of the thymotropic properties of the GH/IGF-1 axis. Further knowledge in this domain will be gained with the use and supplementation of Ghrh-/- mice that will be soon available in our laboratory. References 1. Morrhaye G. et al., PLoS ONE 2009, 4:e5668. 2. Napolitano LA et al. J Clin Invest 2008, 118:1085. 3. Smaniotto S et al., Endocrinology 2005, 146:3005. 4. Taub DD, Murphy WJ and Longo DL. Curr Opin Pharmacol 2010, 10:408. (Supported by F.R.S.-FNRS and a Pfizer Independent Research Grant.) [less ▲]

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See detailLa Carte des Sols de la Belgique, outil d'estimation de l'érosion
Demarcin, Pierre ULg; Legrain, Xavier ULg; Mokadem, Abdel Illah et al

Poster (2011, November 16)

L’érosion des sols a des conséquences très importantes pour la société, d’ordre agronomique (détérioration de la structure, perte en matière organique et en nutriments, diminution des rendements, … ... [more ▼]

L’érosion des sols a des conséquences très importantes pour la société, d’ordre agronomique (détérioration de la structure, perte en matière organique et en nutriments, diminution des rendements, …), économique (coût pour la collectivité, pour les compagnies d’assurance, …) ou environnementale (eutrophisation, contamination des eaux de surface, …). Le Projet de Cartographie Numérique des Sols (PCNSW) met en œuvre une démarche originale d’estimation de l’érosion historique sur les 50 dernières années. Des sondages à la tarière ont été réalisés sur des sites d’étude en Région limoneuse afin d’estimer l’épaisseur des volumes pédologiques. Ces observations ont été comparées à celles des levés de terrain originaux de la Carte des Sols de la Belgique. Si près de 30 % des sondages ne permettent pas de mettre en évidence une évolution en terme d’érosion, la perte en sols sur 50 ans est estimée à plus de 40 cm dans 30 % des cas. [less ▲]

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See detailGenital re-excretion of Murid gammaherpesvirus 4 following intranasal infection
François, Sylvie ULg; Vidick, Sarah ULg; Sarlet, Michaël ULg et al

Poster (2011, November 16)

Gammaherpesviruses are the archetypes of persistent viruses that have been identified in a range of animals from mice to man. As the human gammaviruses have no well-established in vivo infection model ... [more ▼]

Gammaherpesviruses are the archetypes of persistent viruses that have been identified in a range of animals from mice to man. As the human gammaviruses have no well-established in vivo infection model, related animal gammaherpesviruses are an important source of information. We are studying Murid herpesvirus 4 (MuHV-4) in inbred laboratory mouse strains which are commonly accepted as a good model for studying gammaherpesviruses in vivo. To date, it has however never been possible to monitor viral reexcretion and virus transmission in this species. In order to identify potential re-excretion sites, intranasally infected mice were followed through global luciferase imaging for up to six months after infection. Surprisingly, we detected transient viral replication in mice genital tract at various times after latency establishment. Ex vivo imaging, quantitative PCR and immunohistochemistry revealed that virus genomes were present in high quantity in the vaginal tissue and that viral replication occurred mainly at the vaginal external border. Moreover, we highlighted the presence of free infectious viruses in the vaginal cavity at the moment of the observation of viral replication. As this ephemeral viral reexcretion could reveal a link with reproductive cycle, we compared reexcretion in normal and ovariectomized mice. Interestingly, no viral reactivation was observed in absence of hormonal cycle. In conclusion, we experimentally indentified for the first time a reexcretion site for MuHV-4 in mice that had been intranasaly infected. In the future, these results could help us to better understand the biology of gammaherpesviruses but should also allow us to develop strategies that could prevent the spread of these viruses in natural populations. [less ▲]

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See detailReplacement of goal-tracking by sign-tracking under reward uncertainty, and impairment by dopamine antagonism in the rat
Anselme, Patrick ULg; Robinson, Mike J.F.; Difeliceantonio, Alexandra G. et al

Poster (2011, November 16)

Hypothesis: uncertainty influences Pavlovian reward prediction by arousing incentive motivation for reward (or ‘wanting’), expressed as sign-tracking (ST) or goal-tracking (GT) responses in an autoshaping ... [more ▼]

Hypothesis: uncertainty influences Pavlovian reward prediction by arousing incentive motivation for reward (or ‘wanting’), expressed as sign-tracking (ST) or goal-tracking (GT) responses in an autoshaping paradigm. Here we investigated the effect of 3 types of uncertainty: 1) reward probability (UCS occurred after CS+ under 50% probability), 2) uncertainty about reward magnitude (UCS was 1, 2, or 3 sucrose pellets), and 3) uncertainty resulting from a combination of both conditions. We also tested the effects of reversal learning (shift in reward probability from 100 to 50%) and systemic dopamine blockade under uncertainty (flupenthixol, i.p.) on acquisition of autoshaping. [less ▲]

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See detailBINDING INTERACTIONS OF URONIC ACID DERIVATIVES TO LIPID VESICLES INVESTIGATED BY ISOTHERMAL TITRATION CALORIMETRY
Razafindralambo, Hary ULg; Laurent, Pascal ULg; Wathelet, Jean-Paul ULg et al

Poster (2011, November 12)

Uronic acid derivatives (UAD) constitute a particular class of carbohydrate-based small compounds, which are receiving growing interests today for many reasons. Beyond their excellent environmental ... [more ▼]

Uronic acid derivatives (UAD) constitute a particular class of carbohydrate-based small compounds, which are receiving growing interests today for many reasons. Beyond their excellent environmental compatibility, their potentiality mainly arises from the large abundance of their precursors from renewable resources, and the quasi-unlimited availability of their molecular structure and geometry [1]. Such a structural diversity allows them to be a typical compound class for the structure-activity relationship investigation using simplest models. This approach is very important for predicting their functionalities and activities. Among others, searching specific and potent biological activities against target molecules, cells, and micro-organisms is a big challenge today. In this context, binding interactions of three UAD having different hydrophobic residues (allyl, benzyl, and cyclohexyl) to 1-palmitoyl-2-oleyl-sn-glycerol-3-phosphatidylcholine (POPC) vesicles have been investigated using Isothermal Titration Calorimetry (ITC) technique [2]. The binding affinity (Ka) to the membrane model at 25°C has been determined and compared for the three compounds. Based on thermograms resulting from UAD aqueous solution titration experiments, with and without POPC vesicles, it clearly appears that both derivatives with a cyclic residue interact stronger with the lipid membrane model than their linear derivative counter-part, which exhibits almost no interaction. Moreover, the derivative compound with a cyclohexyl residue saturates faster POPC vesicles than that with a benzyl residue. We conclude that: (a) UAD having a cyclic hydrophobic residue, either saturated or unsaturated, bind more easily to the lipid membrane model than a linear one ending with a double bond; (b) the greater the number of hydrogen in the UAD residue chemical structure (saturated bonds), the stronger their binding affinity to POPC vesicles, suggesting the importance of H-bonding to such a lipid membrane model. The Ka mean value of the best tested UAD, i.e. with a cyclohexyl residue, is about 5.103 M-1. [1] Razafindralambo, H.; Blecker, C; and M. Paquot., Screening of basic properties of amphiphilic molecular the structures for colloidal system formation and stability: the case of carbohydrate-based surfactants in: Amphiphiles: Molecular Assembly and Applilcations, ed. R. Nagarajan, ACS, Washignton, 2011, (In press). [2] Razafindralambo, H.; Dufour, S.; Paquot, M.; Deleu, M., Thermodynamic studies of the binding interactions of surfactin analogues to lipid vesicles: application of isothermal titration calorimetry. J. Therm. Anal. Calorim., 2009, 9 (3), 817-821. Acknowledgment: This work was supported by Belgian Walloon Region with DG06 research project of excellence (TECHNOSE). [less ▲]

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See detailLong-term trends of a dozen direct greenhouse gases derived from infrared solar absorption spectra recorded at the Jungfraujoch station
Mahieu, Emmanuel ULg; Duchatelet, Pierre; Zander, Rodolphe ULg et al

Poster (2011, November 10)

References Bader, W. et al., Extension of the long-term total column time series of atmospheric methane above the Jungfraujoch station: analysis of grating infrared spectra between 1976 and 1989 ... [more ▼]

References Bader, W. et al., Extension of the long-term total column time series of atmospheric methane above the Jungfraujoch station: analysis of grating infrared spectra between 1976 and 1989, Geophysical Research Abstracts, 13, EGU2011-3391-1, 2011. [http://hdl.handle.net/2268/88180] Duchatelet, P. et al., First retrievals of carbon tetrafluoride (CF4) from ground-based FTIR measurements: production and analysis of the two-decadal time series above the Jungfraujoch, Geophysical Research Abstracts, 13, EGU2011-6413, 2011. [http://hdl.handle.net/2268/90745] Gardiner, T. et al., Trend analysis of greenhouse gases over Europe measured by a network of ground-based remote FTIR instruments, Atmos. Chem. Phys., 8, 6719-6727, 2008. [http://hdl.handle.net/2268/2545] Rodgers, C.D., Characterisation and error analysis of profiles derived from remote sensing measurements, J. Geophys. Res., 95, 5587-5595, 1990. Zander, R. et al., Our changing atmosphere: Evidence based on long-term infrared solar observations at the Jungfraujoch since 1950, Sci. Total Environ., 391, 184-195, 2008. [http://hdl.handle.net/2268/2421] [less ▲]

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See detailNouvelle répartition géographique des espèces Aedes albopictus et Aedes aegypti (Diptères, Culicidae, Aedinae) à Madagascar
Raharimalala, Fara Nantenaina ULg; Raveloson Ravaomanarivo, Lala Harivelo; Ravelonandro, Pierre et al

Poster (2011, November 09)

Depuis 2006, Madagascar et les îles avoisinantes de l’Océan Indien ont été victimes d’épidémies sévères de dengue et de chikungunya. Les moustiques Aedes albopictus et Aedes aegypti, vecteurs majeurs de ... [more ▼]

Depuis 2006, Madagascar et les îles avoisinantes de l’Océan Indien ont été victimes d’épidémies sévères de dengue et de chikungunya. Les moustiques Aedes albopictus et Aedes aegypti, vecteurs majeurs de ces arboviroses, sont présents à Madagascar et en particulier dans les régions d’émergence épidémique. En vue d’actualiser les données entomologiques, des campagnes de capture d’adultes et de récoltes de larves ont été menées dans 8 régions sélectionnées selon différents niveaux d’anthropisation. Nos résultats ont démontré des changements importants dans la répartition de ces deux espèces vectrices à Madagascar. [less ▲]

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See detailWEEE management using LCA methodology : the fridge case study
Belboom, Sandra ULg; Renzoni, Roberto ULg; Deleu, Xavier et al

Poster (2011, November 03)

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See detailEvaluation of long-term functional deficits following transient cerebral ischemia in two mouse strains
Fassotte, Ludivine ULg; Linden, Jérôme ULg; Ferrara, André ULg et al

Poster (2011, November 03)

Nowadays, no suitable animal model exists to assess long-term disabilities after cerebral ischemia. The aim of this study was to compare long-term behavioral and histological differences between two ... [more ▼]

Nowadays, no suitable animal model exists to assess long-term disabilities after cerebral ischemia. The aim of this study was to compare long-term behavioral and histological differences between two common mouse strains (129S2/SvPasCrl and C57BL6H) after 30 minutes of middle cerebral artery occlusion (MCAo). Sensorimotor assessments were conducted at one and at three weeks post-surgery using accelerated Rotarod and open-field locomotion. Long-term behavioral testing began four weeks after MCAo using operant conditioning in a progressive fixed-ratio (FR) schedule. Experiments ended with volumetric determination of the infarcted area using NeuN immunostaining. Although no effect of ischemia was detected in 129S2 mice using these tests, in C57 mice, results showed obvious short-term motor and locomotor deficits. Furthermore, subtle but persistent disturbances of endurance and executive functioning were recorded by the progressive schedule tests but not highlighted by sensorimotor tests. Ischemic lesion extended to the dorsolateral part of the striatum in both strains and recurrent cortical damages were also observed in C57 mice. All those results are in accordance with inherent morphological and behavioral features of each strain. Since the motor cortex is spared by 30 minutes MCAo, functional disabilities could be related to striatal damages. In conclusion, C57BL/6H mouse strain, by offering an acceptable survival rate and enough sensitivity to MCAo, seems to be a mouse strain suitable to evaluate long-term deficits and possible functional recovery after cerebral ischemia. [less ▲]

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See detailLife cycle assessment of carbon xerogels
Melon, Raphaëlle ULg; Renzoni, Roberto ULg; Léonard, Alexandre ULg et al

Poster (2011, November 03)

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See detailDetermination of optimum conditions for preservation and reactivation of freeze-dried Acetobacter senegalensis used as vinegar starter
Shafiei, Rasoul ULg; Thonart, Philippe ULg

Poster (2011, November)

Availability of efficient starters is one of the most important elements during fermentation technology. Acetic acid bacteria (AAB) face extreme conditions (low pH, high acetic acid concentration (>7 ... [more ▼]

Availability of efficient starters is one of the most important elements during fermentation technology. Acetic acid bacteria (AAB) face extreme conditions (low pH, high acetic acid concentration (>7%), ethanol and high temperature) during vinegar fermentation. In spite of introduction of broth media contained viable AAB as starter by some companies; traditional methods for initiation of vinegar fermentation are still used even in modern factories, therefore there is a long Lag phase for initiation of fermentation. In recent studies in CWBI, a kind of lyophilized starter has been produced by using an isolated thermotolerant bacterium: Acetobacter senegalensis. The aim of this study is to determine the best media for revitalization and the optimum temperature for preservation of the freeze-dried cells. To produce biomass, glucose was used as carbon source in batch culture under regulated conditions. The cells harvested when they reached to stationary phase. Harvested cells suspended in spent growth medium (final supernatant of fermentation). Maltodextrin (10%), manitol (20%) and spent growth medium were used as protestants. After freeze-drying they were subjected to storage test at -20° C, 4° C and 35° C for six months. The viability of cells determined by using spread plate technique using three different media: YG (yeast extract, glucose) and YGE (yeast extract, glucose, ethanol) and YGEA (yeast extract, glucose, ethanol, acetic acid). According to residual viable cells, manitol and maltodextrin showed higher protective functions rather than spent growth medium (92.3%, 88.2% and 82.1% survival, respectively) during freeze-drying process. Viability of cells during rehydration is completely dependent to the composition of the broth media used for this purpose. Adding ethanol (>0.5%) or acetic acid (>1%) to rehydration medium caused 40-45% reduction in viable cell numbers in comparison to YG broth. The composition of culture media can also influence the growth of bacteria after rehydration. In YG, much higher cell growth (about 1 log unit) was observed in comparison to YGE and YGEA. Addition of glucose (20 g/l) to YGE can neutralize the adverse effect of ethanol considerably but it cannot improve the growth in YGEA. This can be partially explained according to the activity of alcohol dehydrogenase and acetaldehyde dehydrogenase. It was revealed that freeze-dried cells had very low activities for these two enzymes. Analysis of total soluble protein contents of lyophilized cells during storage at different conditions revealed that the soluble protein content of cells reduced by increasing the storage temperature. At 35° C after 15 days, there were 4.87 log units reduction in the viability of cells, and also about 14% less soluble protein was detectable under this condition whereas keeping of cells at -20 or + 4° C had no influences on protein and viability of cells. Storage of cells at +4° C in darkness for six month showed that about 79.2% and 68.3% viability of cells remained for cells protected by manitol and maltodextrin, respectively. To assess the real activity of lyophilized cells as starters, they were introduced to broth media (YGE contained 20g/l of glucose). It was seen that 6 months old lyophilized cells (with maltodextrin or manitol as protectants) were able to grow and consume 5 v/v of ethanol in 48 hr in the presence of initial acetic acid concentration (0.5%) at 30° C. In conclusion, the mentioned methods for preservation and reactivation of freeze-dried Acetobacter senegalensis can provide a promising tool for decreasing the lag phase of vinegar fermentation. [less ▲]

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

Poster (2011, November)

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

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

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

Poster (2011, November)

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See detailRetour au travail en cas d'arrêt-maladie de longue durée, le point de vue du patient
Sottiaux, Marianne; Schippers, Nathalie ULg; Mairiaux, Philippe ULg

Poster (2011, November)

Introduction Face à l’enjeu du maintien dans l’emploi en cas de problème de santé, le médecin du travail et le médecin-conseil de sécurité sociale peuvent jouer un rôle important, mais qu’en pense le ... [more ▼]

Introduction Face à l’enjeu du maintien dans l’emploi en cas de problème de santé, le médecin du travail et le médecin-conseil de sécurité sociale peuvent jouer un rôle important, mais qu’en pense le patient ? L’étude avait donc pour objectif d’explorer le point du vue du patient afin d’identifier les obstacles et les éléments facilitateurs sur lesquels ces médecins peuvent s’appuyer pour promouvoir le retour au travail. Méthodologie L’étude a comporté l’interview téléphonique de 100 patients recrutés via deux organismes assureurs. Les critères d’inclusion étaient : être en arrêt de travail de longue durée (3 mois< arrêt < 8 mois), bénéficier d’une surveillance de santé en médecine du travail, et accepter de participer à l’étude. Résultats Les principales causes des absences sont les affections mentales (21%), les pathologies rachidiennes (11%) et les traumatismes (16%). Pour pouvoir retourner au travail, 40% des répondants disent attendre un effet du traitement ou une amélioration de leur état et 62% désignent le manque d’amélioration ou l’aggravation de celui-ci comme facteur freinant leur reprise. Un autre facteur est le manque de compréhension des collègues et/ou du chef hiérarchique. La majorité des répondants estiment qu’un travail adapté (diminution de la charge de travail ou des heures prestées, adaptation des horaires,…) faciliterait la reprise. Les répondants ont une perception plutôt négative du médecin du travail: la visite périodique est décrite comme superficielle et brève et peu connaissent le rôle du médecin. La plupart des répondants accepteraient que les médecins en charge de leur dossier se concertent à leur sujet mais s’interrogent quant à l’utilité d’un tel échange. Conclusions L’aide que le médecin du travail peut apporter au patient pour la reprise de travail est largement ignorée et de nombreux obstacles entravent les possibilités de coopération entre médecin du travail et médecin-conseil pour favoriser le maintien dans l’emploi. [less ▲]

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

Poster (2011, November)

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

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

Poster (2011, November)

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

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

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See detailApport de la métacognition dans la remédiation des troubles d’apprentissage
Frenkel, Stéphanie ULg; Keppenne, Julien ULg

Poster (2011, November)

Thème De plus en plus d’élèves présentent des difficultés d’apprentissage ; qu’elles soient ou non accompagnées d’une déficience intellectuelle. Qu’ils présentent un trouble spécifique du langage et des ... [more ▼]

Thème De plus en plus d’élèves présentent des difficultés d’apprentissage ; qu’elles soient ou non accompagnées d’une déficience intellectuelle. Qu’ils présentent un trouble spécifique du langage et des apprentissages ou ce que l’on appelle un échec scolaire généralisé, ces élèves ont un point commun ; celui de présenter un déficit métacognitif (cf. Doudin, Martin & Albanese, 2001 ; Hessels & Hessels-Schlatter, 2010). Problématique et principales référence théoriques À l’interface de différents champs disciplinaires (psychologie du développement, psychologie cognitive, éducation cognitive, systémique appliquée au domaine scolaire et neuropsychologie), nous avons créé un Atelier d’Apprentissage dans le cadre de la Clinique Psychologique Logopédique Universitaire de l’ULg. Type de méthodologie Ce service d’éducation cognitive centré sur le diagnostic et la remédiation de difficultés d’apprentissage et de problèmes scolaires est une des solutions que nous proposons à cette recrudescence des élèves en difficulté d’apprentissage. L’atout majeur de ces actions au niveau métacognitif est qu’elles donnent la possibilité d’améliorer ou de développer les compétences sous-tendant l’apprentissage et qu’elles ont un double impact : impact au niveau de la sphère cognitive (e.g., stratégies de résolution de problèmes, capacités métacognitives) et impact au niveau de la sphère conative (e.g., amélioration de la confiance en soin et de l’estime de soi, augmentation de la motivation intrinsèque et des objectifs d’apprentissage). Principaux éléments développés et résultats Dans ce cadre, nous travaillons sur la formalisation et la validation de programmes de remédiation ; cela en fonction de différentes variables que sont notamment l’âge de l’élève, son potentiel d’apprentissage, la nature de ses difficultés et la présence de troubles associés. Conclusion Dans cette communication orale, nous proposons de présenter et discuter cette approche et la possibilité de la développer au sein des établissements scolaires ; que ce soit aux niveaux préventif ou palliatif. Références théoriques : Büchel, F.P. (Ed.). (1995). L’Education cognitive. Le développement de la capacité d’apprentissage et son évaluation. Neuchâtel : Delachaux et Niestlé. Doudin, P.A., Mardin, D., & Albanese, O. (2001). Métacognition et éducation. Berlin : Peter Lang. Hessels, M.G.P., & Hessels-Schlatter, C. (2010). Evaluation et intervention auprès d’élèves en difficulté. Bern : Perter Lang. Vianin, P. (2009). L’aide stratégique aux élèves en difficulté scolaire. Bruxelles, Belgique : De Boeck. [less ▲]

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See detailOzone tropospheric and stratospheric trends (1995-2011) at six ground- based FTIR stations (34°S to 79°N)
Vigouroux, Corinne; Demoulin, Philippe ULg; Hase, Frank et al

Poster (2011, November)

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

Five ground-based stations in Western Europe, from 79°N to 28°N, all part of the Network for the Detection of Atmospheric Composition Change (NDACC), have joined their efforts to homogenize and optimize the retrievals of ozone profiles from FTIR (Fourier transform infrared) solar absorption spectra. Using the optimal estimation method, distinct vertical information can be obtained in four layers: ground—10 km, 10—18 km, 18—27 km, and 27—42 km, in addition to total column amounts. A bootstrap resampling method has been implemented to determine annual partial and total column trends. Vigouroux et al. (2008) applied this method to the ozone data and discussed the trends of the total columns and of the partial columns in the above four layers, over the period 1995-2004. The updated trends for the 1995-2009 period has been published in the WMO 2010 report. Here, we present the updated trends for the 1995-mid-2011 period, for the five European stations but also for a southern hemisphere station, Wollongong (34°S), which recently joined this ozone network. [less ▲]

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See detailReproductive impact and proteomic analysis of androgenic and anti-androgenic disruptors on the hermaphroditic freshwater gastropod Lymnaea stagnalis
Giusti, Arnaud ULg; Ducrot, Virginie; Joaquim-Justo, Célia ULg et al

Poster (2011, November)

In this study, e ects of two androgens (tributyltin and testosterone), one antiandrogen (cyproterone acetate) and one estrogen (chlordecone) on growth and reproduction were investigated in the ... [more ▼]

In this study, e ects of two androgens (tributyltin and testosterone), one antiandrogen (cyproterone acetate) and one estrogen (chlordecone) on growth and reproduction were investigated in the hermaphrodite gastropod Lymnaea stagnalis. In this study, exposure to a range of concentrations (ng/l to μg/l) of each chemical was performed during 21 days. e number of clutches and the number of eggs per clutch were monitored. A decrease in clutches laid per snail was observed after exposure to tributyltin (540, 1180 and 2600 ng/l) and chlordecone (10, 22, 50 and 110 μg/l). A signi cant decrease in egg laid per snail was observed after exposure to tributyltin (540, 1180 and 2600 ng/l) and chlordecone (50 and 110 μg/l). An increase of egg abnormalities ratio in exposed snails (atrophied albumen, polyembryonicity,...) was observed in L. stagnalis following exposure to testosterone (2, 22, 50 and 110 ng/l), cyproterone acetate (4,5 and 50 μg/l), tributyltin (110 and 244 ng/l) and chlordecone (4,5 and 10 μg/l). Investigation of alteration in protein expression in exposed snails was performed using proteomic analysis such as 2D-DIGE. Mass spectrometry identi cation was performed on proteins with altered expression. We could establish correlation between reproductive endpoints and changes in proteins involved in egg formation and in egg laying were underlined. Egg yolk ferritin, the main protein of egg yolk, was shown to be reduced signi cantly in relationship with a decrease of egg yolk quality after exposure to tributyltin 540 ng/l and cyproterone acetate 4,5 μg/l. Ovipostatin, a protein proved to reduce egg masses, was signi cantly over expressed in snails exposed to 50 μg/l of chlordecone and were in relationship with a reduction of clutches laid by individuals. Further western blot analysis on those proteins involved in the reproduction are underway. ese analysis will enable us to con rm and re ne with more speci city the 2D-DIGE results for the selected proteins. e results of this study can help to establish new biomarkers of exposure of endocrine disruptors in freshwater environment and can provide new insight on mode of action of endocrine disruptors in L. stagnalis. [less ▲]

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See detailInterventions cognitivo-comportementales en dialyse
Rocha, Cindy; Bragard, Isabelle ULg; Krzesinski, Jean-Marie ULg et al

Poster (2011, November)

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

Poster (2011, October 27)

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

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

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

Poster (2011, October 27)

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

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

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

Poster (2011, October 25)

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

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

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

Poster (2011, October 25)

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

Poster (2011, October 25)

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

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

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

Poster (2011, October 19)

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

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

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

Poster (2011, October 18)

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

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

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