References of "Poster"
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Peer Reviewed
See detailItem purification versus adjustments for multiple comparisons in DIF detection
Drabinova, Adela; Martinkova, Patricia; Magis, David ULiege

Poster (2017, July 18)

Detailed reference viewed: 25 (1 ULiège)
Peer Reviewed
See detailA Novel Accelerometer-Based Method for Stride Length Estimation
Boutaayamou, Mohamed ULiege; Schwartz, Cédric ULiege; Denoël, Vincent ULiege et al

Poster (2017, July 14)

We demonstrate the feasibility of accurately and precisely estimating the left/right average stride length from measured heel/toe accelerations in the gait of healthy, old adults. Our approach relies on ... [more ▼]

We demonstrate the feasibility of accurately and precisely estimating the left/right average stride length from measured heel/toe accelerations in the gait of healthy, old adults. Our approach relies on (1) a novel method that uses only accelerometer data without the need of additional data from, e.g., gyroscopes and/or magnetometers, and on (2) the validation of the results using reference 3D optoelectronic system data. [less ▲]

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Peer Reviewed
See detailNon-pathological aging of the executive functions: influence of the Val108/158Met nucleotide polymorphism of the COMT gene
Gilsoul, Jessica ULiege; Manard, Marine ULiege; Collette, Fabienne ULiege

Poster (2017, July 13)

Objectives. The aim of the study is to investigate the influence of the COMT Val108/158Met nucleotide polymorphism, associated with dopaminergic regulation, on executive functions in normal aging. Indeed ... [more ▼]

Objectives. The aim of the study is to investigate the influence of the COMT Val108/158Met nucleotide polymorphism, associated with dopaminergic regulation, on executive functions in normal aging. Indeed, according to the Dual-State Theory, Val/Val polymorphism of the COMT gene would favor better flexibility abilities, whereas Met/Met carriers would favor better stability abilities. These genotypic effects should be magnified in older people, as a decrease in cognitive resources increases the influence of individual genetic differences on cognitive performance. Method. We assessed the executive processes of inhibition, shifting, and updating – thanks to many different tasks in groups of young (n = 55) and aged participants (n = 45) carrying one of the three polymorphism of the COMT gene (Val/Val, Val/Met, Met/Met). T-tests between our two groups (Young versus Aged) but also a 6 (Group: Young-Met/Met, Young-Val/Met, Young- Val/Val, Old-Met/Met, Old-Val/Met, and Old-Val/Val) X 3 (Executive functioning: Inhibition, Shifting, and Updating) repeated measure ANOVA with Executive functioning as within-subject factor (p < .05) were carried out. Results. Young and old participants significantly differed on the three executive functions. The comparison of genotypic groups showed no significant differences in young or older participants respectively. Interestingly, the Old-Val/Val group showed a lower performance than the young one on inhibition tasks. Conclusion. As expected, we found an age effect on all the executive functions. The significant difference between the Young-Val/Val and the Old-Val/Val groups on inhibition suggests an age-related decrease in abilities requiring a stability component in individuals possessing a less favoring genotype for this component. [less ▲]

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See detailDetermining fine population structure using iterative pruning
Chaichoompu, Kridsadakorn ULiege; Yazew, Fentaw Abegaz; Tongsima, Sissades et al

Poster (2017, July 10)

SNP-based information is used in several existing clustering methods to detect shared genetic ancestry or to identify population substructure (Price et al. 2006, Raj et al. 2016). Here, we present an ... [more ▼]

SNP-based information is used in several existing clustering methods to detect shared genetic ancestry or to identify population substructure (Price et al. 2006, Raj et al. 2016). Here, we present an unsupervised clustering algorithm called the iterative pruning method to capture population structure (IPCAPS). Our method supports ordinal data which can be applied directly to SNP data to identify fine-level population structure and it is built on the iterative pruning Principal Component Analysis (ipPCA) algorithm (Intarapanich et al. 2009). The IPCAPS involves an iterative process using multiple splits based on multivariate Gaussian mixture modeling of principal components and Clustering EM estimation as in Lebret et al. (2015). In each iteration, rough clusters and outliers are also identified using our own method called RubikClust. The fixation index (FST) is known to measure a distance between populations and FST = 0.001 may be said to be genetically distinct among the European populations (Tian et al. 2008, Huckins et al. 2014). To observe fine-level population structure using FST, we examined simulated scenarios of one population, 500-8,000 individuals, 5,000-10,000 independent SNPs in HWE (Balding and Nichols 1995), with 100 replicates for each scenario. The simulated SNPs were encoded as additive coding and there was no missing genotype generated. We introduced negative control by subjecting individuals to be separated into two groups using kmeans. We observed that FST values of divided groups were lower than 0.0008, which can be defined as the minimum FST to detect fine-level population structure. To evaluate the performance of our method, we tested different simulated data sets of 2-3 populations, 250 individuals per population, 10,000 independent SNPs in HWE, and FST=[0.0008,0.005], with 100 replicates for each data set. For real-life data sets, we applied the IPCAPS to Thai (Wangkumhang et al. 2013) and HapMap populations. Our method showed that a population classification accuracy was superior to the ipPCA in simulated scenarios of extremely subtle structure (FST=[0.0009,0.005]). In case of the Thai population, results to detect fine-level structure were obtained as well as in case of the HapMap populations. We are convinced that the IPCAPS has a potential to detect fine-level structure and it will be important in molecular reclassification studies of patients once underlying population structure has been removed. [less ▲]

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See detailSTUDY OF ACTIVATED SLUDGE DEWATERING : USING BIOBASED COAGULANTS
Fraikin, Laurent ULiege; Clermont, Quentin; Salmon, Thierry ULiege et al

Poster (2017, July 06)

This paper focuses on the dewatering efficiency of activated sludge from waste water treatment plant using biobased coagulants in addition with classical flocculant and compares the results with those ... [more ▼]

This paper focuses on the dewatering efficiency of activated sludge from waste water treatment plant using biobased coagulants in addition with classical flocculant and compares the results with those obtained with a sole classical coagulant. For this work, a standard compression-expression cell is used and an experimental design is develop to highlight the effect of the biobased coagulants. [less ▲]

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Peer Reviewed
See detailComparative Proteomics Analysis Provides New Candidates for Zinc Homeostasis Regulation in Arabidopsis
Amini, Sahand ULiege; Arsova, Borjana ULiege; Scheepers, Maxime ULiege et al

Poster (2017, July 03)

Zinc (Zn) is an essential micronutrient for plants and around two billion people are depending on grains and legumes as their main Zn source. On the other hand, this transition metal is toxic for plants ... [more ▼]

Zinc (Zn) is an essential micronutrient for plants and around two billion people are depending on grains and legumes as their main Zn source. On the other hand, this transition metal is toxic for plants at high concentrations in soils. This calls for a better unravelling of Zn homeostasis regulation mechanisms, including sensing and signaling in plants. In order to fulfill this aim, we are testing for novel proteins involved in Zn homeostasis in the model plant Arabidopsis thaliana. First, quantitative proteomics was performed on root and shoot samples obtained upon Zn starvation and re-supply in different spatio-temporal conditions. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) analysis was also performed for those treatments to measure the Zn concentration in tissues. It showed very rapid Zn uptake in root upon re-supply. Moreover, quantitative expression studies of known players of Zn homeostasis confirmed our large-scale proteomic results, although for a few genes lack of correlation between transcript and protein regulation was observed. Using clustering, statistical and gene ontology analyses, we selected candidate genes for further studies. Among more than 5000 detected proteins in roots by shotgun proteomics, 75 genes were selected for targeted analyses. In general, our results show that comparative proteomics study can be useful to reveal new players in the Zn regulatory network in plants, which can lead to new Zn biofortification and phytoremediation strategies. [less ▲]

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See detailSimultaneous Determination of Free Amino Acid Content in Different Teas using Supercritical Fluid Chromatography Coupled with Single Quadrupole Mass Spectrometry
Huang, Yang ULiege; Fillet, Marianne ULiege; Crommen, Jacques ULiege et al

Poster (2017, July 02)

Tea (Camellia sinensis L.) is a complex mixture containing a wide range of biological activities and has been used as widely consumed beverages and natural medicine for over thousand years [1-2]. In this ... [more ▼]

Tea (Camellia sinensis L.) is a complex mixture containing a wide range of biological activities and has been used as widely consumed beverages and natural medicine for over thousand years [1-2]. In this study, a novel method for high-performance liquid chromatography with mass spectrometry (SFC-MS) has been developed to simultaneously determine the contents of 11 free amino acids in different types of teas (pu-erh tea, green tea, black tea and oolong tea). The separation conditions for the selected amino acids were carefully optimized such as the column type, temperature and backpressure, the type of additive. The best compromise for tested analytes in terms of chromatographic performance was obtained when water (5%) and trifluoroacetate acid (0.4%) were added to the supercritical carbon dioxide/methanol mobile phase. Finally, the developed SFC-MS method was successfully applied to the analysis of the 11 amino acids present in the teas and fully validated as well. The results indicated a good linearity (r ≥0.995), precision (RSD≤ 2.99%), stability (RSD≤ 2.88%) and accuracy (91.95%~107.99%). The limits of detection ranged from 1.42 to 14.69 ng/mL, respectively, while the limits of quantification were between 4.53 and 47.0 ng/mL. The content of the amino acids in six different tea samples were also determined and presented some difference basing on the fermentation processes. The proposed SFC-MS method showed a great potential in further investigations to differentiate tea varieties [less ▲]

Detailed reference viewed: 31 (1 ULiège)
See detailAntarctic sea ice trophic status
Van der Linden, Fanny ULiege; Moreau, Sébastien; Champenois, Willy ULiege et al

Poster (2017, July)

The sea ice ecosystem is characterized by steep gradients in temperature, salinity, light and nutrient availability. Despite these challenging environmental conditions, sea ice provides a dynamic habitat ... [more ▼]

The sea ice ecosystem is characterized by steep gradients in temperature, salinity, light and nutrient availability. Despite these challenging environmental conditions, sea ice provides a dynamic habitat for diverse communities of microorganisms. These communities include a wide variety of organisms from different taxonomic groups such as algae, bacteria, heterotrophic protists, fungi as well as viruses [Horner et al., 1992; Deming, 2010; Thomas and Dieckmann, 2010; Poulin et al., 2011]. In the frame of the YROSIAE project (Year-Round survey of Ocean-Sea-Ice-Atmosphere Exchanges), carried out at Cape Evans in McMurdo Sound (Antarctica) from Nov. 2011 to Dec. 2012, ice cores, seawater, and brine material were collected at regular time intervals. Physical properties (salinity, temperature, texture) and biogeochemical parameters (pCO2, dissolved inorganic carbon, total alkalinity, chlorophyll-a, macro-nutrients) were analysed. We will here particularly consider changes inused dissolved inorganic carbon (DIC) and chlorophyll-a (chl-a) , used as a proxiesy of net community production and autotrophic biomass, respectively. A high spatial and temporal variability in ice algal biomass and DIC evolution were observed. From spring, very high chl-a concentrations (>2400μg.L^(-1)) were observed at the bottom of the ice, a common feature of land fast ice in the McMurdo Sound. This suggests high primary production. However Strikingly, , at the same time, nutrients at the bottom of the ice increased significantly suggesting high heterotrophyremineralisation. In the middle of the ice column, evolution of DIC is was marked by a succession of autotrophic and heterotrophic phases. The overall increase of DIC suggests that the ice interior was rather heterotroph. Such sea ice system should expel CO2. Yet, strong under-saturation in CO2 and DIC depletion appeared at the ice surface, suggesting that sea ice was taking up CO2 from the atmosphere. On the whole, land fast sea ice in McMurdo Sound appears as a puzzling ecosystem. It is able to support elevated growth of autotrophic organisms at the bottom, but still appears to be heterotrophicin parallel to high remineralization, while the top of the ice appears to be rather heterotrophic but stilland able to pump CO2 from the atmosphere. [less ▲]

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See detailCANINE GANGRENOUS MASTITIS : A CASE REPORT
Egyptien, Sophie ULiege; Lefebvre, Michaël ULiege; Guieu, Liz-Valéry ULiege et al

Poster (2017, July)

This report describes the treatments and discusses the cost effectiveness of a Negative Pressure Wound Therapy (NPWT) device on a gangrenous mastitis case. Mastitis is an inflammation of the mammary gland ... [more ▼]

This report describes the treatments and discusses the cost effectiveness of a Negative Pressure Wound Therapy (NPWT) device on a gangrenous mastitis case. Mastitis is an inflammation of the mammary gland found mainly in lactating females. Coliforms (Escherichia coli), Staphylococcus spp (Staphylococcus aureus) and, to a lesser extent, Streptococcus spp are the most commonly isolated organisms in bitches. The bitch can be presented because of local signs of inflammation, puppies failing to thrive or even severe septic shock. While more common in ruminants, gangrenous mastitis is rare in the bitch. It is mostly due to Staphylococcus aureus, a gram positive and catalase positive bacteria producing alpha hemolysin. This toxin binds to ADAM10, a transmembrane protein, forming pores in the cell membrane, causing an acute inflammation via intracellular calcium flow, leading to severe oedema, necrosis and gangrene. Loss of skin integrity also comes from the cleavage of E-cadherin by ADAM10 after its toxin-mediated activation. A 8.7kg, 3-year-old neutered female Sheltie farm dog was referred to the Veterinary Clinic of the University of Liège for suspicion of septic peritonitis after an ovariohysterectomy on 4 dead puppies 36 hours earlier. They died during long lasting dystocia. Amoxicillin-acid clavulanic and enrofloxacin antibiotherapy had been initiated during surgery. The dog was in decompensated septic shock. The surgical wound was not reactive and no sign of peritonitis was seen by abdominal ultrasonography. The right inguinal and the two most caudal left mammary glands were swollen, crackling with a patchy blue discoloration. An acute fulminant mastitis with gangrenous involvement and sepsis was diagnosed. Fluids and continuous rate infusion of norepinephrine and dobutamine were administered to control severe hypotension. Metronidazole was added since Clostridium spp could not be excluded. Debridement was started as soon as the arterial pressure was stabilised and the wound was disinfected with hydrogen peroxyde for the 3 first days. While hydrogen peroxyde is indicated for catalase negative infections, the already started antibiotherapy prevented bacterial identification and sensitivity determination. Alginate-honey patches replaced wet to dry bandages after 4 days. After 7 days of progressive debridement, the wound was 15cm long, 13cm wide and 1.2cm deep. A NPWT device was placed under anaesthesia after extensive debridement. It was kept in place for one week with one renewal after 2 days under slight sedation. The wound was then surgically closed. Cutaneous sutures were removed 10 days later as cicatrization was satisfactory. NPWT is indicated in open wound management, for infection control and for stimulating granulation tissue production prior to reconstruction. It increases contraction in deep, three dimensional wounds. Closure rate is significantly shorter with NPWT than with standard wet to dry bandages. Cost of NPWT is comparable to standard bandages but more comfortable for the patient. Standards bandages require daily changes, sometimes for several weeks and under repeated anaesthesias, which may be debilitating for the patient and expensive for the owner. Conversely, NPWT is changed only once and allows earlier surgical closure of the wound. The main complication is vacuum loss, which is surgeon’s experience dependant. [less ▲]

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See detailStable isotopes reveal effects of environmental changes on ecological niches of Iphimediidae amphipods
Michel, Loïc ULiege; d'Udekem d'Acoz, Cédric; Frederich, Bruno ULiege et al

Poster (2017, July)

When faced with environmental changes, organisms are expected to have some intrinsic ability to adapt through ecological plasticity. However, this process is still poorly understood in many Antarctic ... [more ▼]

When faced with environmental changes, organisms are expected to have some intrinsic ability to adapt through ecological plasticity. However, this process is still poorly understood in many Antarctic invertebrates. Here, we focused on Iphimediidae amphipods, as this widely distributed family shows important ecological diversity. In total, 248 amphipods (19 species) from two widely different zones (the West Antarctic Peninsula, or WAP, and Adélie Land, AL) were studied to elucidate how environment can influence ecological niche parameters. Ecological niches were explored using stable isotope ratios of carbon and nitrogen and the SIBER approach (Jackson et al., 2011). The isotopic niche of the whole amphipod assemblage was wider in WAP than in AL. This was true for both total (proxy of the whole range of resources exploited by animals) and the core (proxy of the most commonly used resources) isotopic niches. The ratio between total and core isotopic niches was smaller in WAP than in AL (4.13 vs. 5.74), suggesting that in WAP, animals commonly use a greater relative percentage of the resources to which they have access. Niche modelling at the specific level revealed that this trend was not found in all taxa. For example, niches of Gnathiphimedia sexdentata and Iphimediella microdentata were bigger in WAP than in AL, following the general pattern. On the other hand, niches of Echiniphimedia echinata and E. hodgsoni had the same width in both areas. Moreover, relative niche overlap between these two species was much higher in WAP (42%) than in AL (20%). Our results indicate that the widely different environmental conditions encountered by the animals in these two zones clearly influence their ecology. Overall, Iphimediidae amphipods tend to exploit more resources in WAP, i.e. in the zone where impacts of global change (temperature increase, sea ice cover decrease) are the strongest. Niche overlap between some closely related (i.e. congeneric) species was also more important in WAP. Ultimately, environmental changes in this region might reinforce these trends, which might lead to competition and perturb amphipod community structure. This research was funded by the Belgian Federal Science Policy Office (BELSPO) in the framework of the vERSO and RECTO projects. [less ▲]

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See detailClinical outcome after tracheal resection and anastomosis for correction of a tracheal stenosis in a sport pony
Salciccia, Alexandra ULiege; Roose, Charlotte; Joostens, Zoé ULiege et al

Poster (2017, July)

Introduction: Tracheal stenosis, which refers to a narrowing of the tracheal lumen, is infrequent in horses. The literature is scarce about outcome after treatment of this pathology. Objectives: To report ... [more ▼]

Introduction: Tracheal stenosis, which refers to a narrowing of the tracheal lumen, is infrequent in horses. The literature is scarce about outcome after treatment of this pathology. Objectives: To report our experience using tracheal resection and anastomosis to treat a severe trauma-induced tracheal stenosis (< 1 cm diameter of lumen) involving 2 tracheal rings causing a loud respiratory noise at rest in a 14 y.o. event pony. Methods: The pony was trained to wear a martingale preoperatively. Before the surgery, a distal tracheotomy was performed for placement of the tracheal tube for maintenance of gaseous anaesthesia. Through a 35 cm ventral midline cervical incision, the trachea was exposed and separated from adjacent tissues. Stay sutures were placed in tracheal cartilage adjacent to the segment to be removed. The 2 tracheal rings involved in the stricture were subsequently removed. On both remaining segments of the trachea, the mucosa was turned back over the open end and sutured to the adventitia. The head was then flexed and tracheal ends were apposed using 5 stainless steel wires placed equidistantly around the trachea without mucosal penetration. The anastomosis was completed by a simple continuous suture of resorbable material on the adventitia. A closed suction drain was applied in the soft tissue before routine closure of the subcutaneous and cutaneous layers. The martingale was applied before the recovery from anaesthesia, which was uneventful. The tracheotomy tube and the suction drain were left in place for 48h. The martingale was removed after 3 weeks. The pony was discharged 1 month after surgery. Control endoscopies were performed during hospitalisation and at 7, 10, 17, 21 and 30 weeks and 1 year after surgery. Results: A moderate cicatrix recurred. The excessive tissue was injected with triamcinolone and then with 4% formaldehyde during the first endoscopies and remained stable thereafter. Some stainless steel cerclages broke and displaced slightly. This caused the formation of a self-resolving seroma caudally to the trachea. A moderate respiratory noise was still audible at low-intensity work, which was resumed 4 months postoperatively. However, work was stopped before achieving the preoperative level because the pony developed a lameness. Conclusions: Although a moderate tracheal cicatrix recurred after surgery, tracheal resection and anastomosis clearly improved the quality of life of this pony. [less ▲]

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See detailThe question of the methane increase through the retrieval of its isotopologues from FTIR ground-based observations
Bader, Whitney ULiege; Strong, Kimberley; Walker, Kaley

Poster (2017, July)

Methane (CH4) is the second most important greenhouse gas emitted by human activities in the Earth’s atmosphere. Although it is roughly 200 times less abundant than carbon dioxide, it is a 28 times more ... [more ▼]

Methane (CH4) is the second most important greenhouse gas emitted by human activities in the Earth’s atmosphere. Although it is roughly 200 times less abundant than carbon dioxide, it is a 28 times more potent greenhouse gas. Approximately one fifth of the changes in the Earth’s balance energy caused by human-linked greenhouse gases since the beginning of industrialization (~1750) is due to methane. Methane is emitted by both natural sources and human activities. Indeed, methane can be emitted to the atmosphere through coal mining, oil and gas exploitation, rice cultures, domestic ruminant animals, biomass burning, waste management, wetlands, termites, methane hydrates and ocean. Since the beginning of the industrialization, atmospheric methane concentrations have increased by 260% to reach 1824 pbb in 2013. From the 1980s until the beginning of the 1990s, atmospheric methane was significantly on the rise, then stabilized during 1999-2006 to rise again afterwards. To this day, the source or sink responsible of this latter increase remains unexplained. Through each emission process, heavy molecules of methane (with one additional neutron either on a carbon or on one hydrogen atom) are emitted along methane (12CH4). The main heavy molecules of methane, called isotopologues (13CH4 and CH3D), are respectively ~110 and ~60 000 times less abundant than methane. Despite their small abundances, they give crucial information on the concentration of methane in the atmosphere and its evolution. Indeed, both isotopologues are emitted with specific emission ratio depending on the emission sources. Determining isotopic ratio of atmospheric methane is therefore a unique tracer of its budget. While the non-monotonous trend of methane is subject of an extensive number of studies, to our knowledge, no study of the isotopic ratio of methane derived from ground-based solar observations has been published to date. Measurements of heavy methane from Fourier Transform InfraRed spectra recorded with state of the art spectrometers installed at Eureka [Arctic, Canada] and Toronto [Ontario, Canada] will help fill this gap. Indeed, the produced time series will ease data interpretation and contribute to a global view of the question of isotopologues. [less ▲]

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See detailBeta Cell Regeneration in Zebrafish : Investigating the Ductal Contribution
Bergemann, David ULiege; Massoz, Laura; Bourdouxhe, Jordane ULiege et al

Poster (2017, July)

Diabetes is characterized by the loss of insulin producing beta cells. Although different therapeutic strategies do exist, they lack precise and dynamic control of glycemia as carried out by endogenous ... [more ▼]

Diabetes is characterized by the loss of insulin producing beta cells. Although different therapeutic strategies do exist, they lack precise and dynamic control of glycemia as carried out by endogenous beta cells. One promising alternative is to replenish the pancreas with bona fide functional beta cells by triggering regeneration mechanisms. Previous studies have shown beta cell neogenesis originating from different pancreatic cell types (alpha, delta, acinar and ductal cells), depending on the used model. The ductal origin is supported by the fact that the embryonic duct epithelium gives rise to the endocrine lineage, and that in healthy and diabetic human adults, insulin positive cells could be found next to or in pancreatic ducts. Despite these observations, mammals show very limited regenerative capabilities, making it difficult to investigate those mechanisms. In contrast, zebrafish are extensively used for regeneration studies. The ability of adult zebrafish to regenerate its beta cells and restore normoglycemia after massive beta cell ablation has already been shown. We, and other groups, have previously shown that adult pancreatic duct cells act as progenitors, giving rise to beta cells in physiological and induced diabetic condition in vivo. To get insight into this process, we conducted comparative RNA-seq experiments on pancreatic duct cells from adult zebrafish. By this means, we identified regulated gene expression that can be linked to specific processes/pathways such as cell cycling and Notch. In order to confirm the involvement of identified candidate genes/pathways, we are setting up a screening method using chemical activators and inhibitors in old larvae, by looking at their ability to modify proliferation/differentiation of duct cells after beta cell ablation. In addition, we are also investigating the effect of mutations, generated by the CRISPR/Cas9 system within candidate genes, on the regeneration capabilities. Together, these strategies should provide new clues about regenerative processes triggered in duct cells that might be applied to overcome the poor regenerative capabilities of mammals. [less ▲]

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See detailImpact of endophytic entomopathogenic fungus on plant attractivity in aphid-virus-plant interactions
Fingu Mabola, Junior Corneille ULiege; Bosquée, Emilie ULiege; Boullis, Antoine ULiege et al

Poster (2017, July)

Endophytic entomopathogenic fungi (EEPF) are biological control agents able to live in their host plants in a symbiotic interaction and secrete secondary metabolites in the host plant tissues interacting ... [more ▼]

Endophytic entomopathogenic fungi (EEPF) are biological control agents able to live in their host plants in a symbiotic interaction and secrete secondary metabolites in the host plant tissues interacting with pests and phytopathogenic agents like plants virus. This is the case of Barley yellow dwarf virus (BYDV) transmitted by the Bird cherry oat aphid (Rhopalosiphum padi Linnaeus) and the Grain aphid (Sitobion avenae Fabricius). This virus is one of the most economically important phytoviruses affecting major world cereal crops such as wheat, rice and corn, causing significant yield losses. In this study, we investigated the influence of EEPF presence in the plant tissues on the vector’s orientation preference by considering the insect virus-infection status. We performed a choice test in Petri dishes and collection of volatile compounds emitted by plants. The impact of these interactions between plant-fungi-virus is finally discussed. [less ▲]

Detailed reference viewed: 54 (4 ULiège)
See detailWhere does the methane entrapped in Antarctic sea ice come from?
Jacques, C.; Sapart, Célia Julia ULiege; Carnat, G. et al

Poster (2017, July)

Methane (CH4) atmospheric concentrations have increased by a factor of 2.5 since the beginning of the Industrial Era, mainly because of anthropogenic activities. However, between 1999 and 2006, CH4 growth ... [more ▼]

Methane (CH4) atmospheric concentrations have increased by a factor of 2.5 since the beginning of the Industrial Era, mainly because of anthropogenic activities. However, between 1999 and 2006, CH4 growth rate declined to a near-zero level, suggesting that an equilibrium had been reached. But, from 2007 on, atmospheric concentrations underwent a renewed growth, implying major ongoing changes in the CH4 global budget (Nisbet et al., 2016). These changes challenge our understanding on the contribution of existing sources, and in particular natural sources. Sea ice can strongly affect emissions of CH4 from the ocean, but the precise mechanisms are not well understood. Sea ice has long been considered as an inert and impermeable barrier, but recent studies have highlighted the existence of gas fluxes at the atmosphere-sea ice and sea ice-seawater interfaces (Kort et al., 2012; He et al., 2013; Zhou et al., 2014; Sapart et al., 2016). However, these fluxes are to date poorly understood and quantified. To improve future climate projections, we aim to investigate the control exerted by sea ice on the CH4 atmospheric budget. To unravel the impacts of the Antarctic sea ice physical environment on biogeochemical cycles, the AWECS (Antarctic Winter Ecosystem Climate Study) expedition was conducted between the 8th of June and the 12th of August 2013 in the Weddell Sea. Such an expedition provides a rare opportunity to obtain insights on the behaviour of sea ice during winter. Ice cores specifically dedicated to the investigation of gas dynamics were collected at ten different stations. In order to determine CH4 formation and removal pathways in sea ice, we used concentration and stable isotope analysis, which can help to distinguish different processes. Here, we present and discuss our first results of the isotopic composition of CH4 (δ13C and δ D) on sea ice cores from the Weddell Sea and the Ross Ice Shelf. This new dataset will help to determine the origin of the CH4 entrapped in Antarctic sea ice and its potential impact on the current and future atmospheric CH4 budget. [less ▲]

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See detailN2O production and cycling within Antarctic sea ice
Kotovitch, Marie ULiege; Tison, J.-L.; Fripiat, François ULiege et al

Poster (2017, July)

Nitrous oxide (N2O) is a potent greenhouse gas that has a lifetime of 114 years in the atmosphere and a global warming potential 300 time higher than that of CO2. However there are still large ... [more ▼]

Nitrous oxide (N2O) is a potent greenhouse gas that has a lifetime of 114 years in the atmosphere and a global warming potential 300 time higher than that of CO2. However there are still large uncertainties and gaps in the understanding of the N2O cycle in polar oceans and particularly associated to sea ice. Sources and sinks of N2O are therefore poorly quantified. To date, only one study by Randall et al. 2012 present N2O measurements in sea ice. They pointed out that sea ice formation and melt has the potential to generate sea-air or air-sea fluxes of N2O, respectively. The main processes (except the transport processes) involved in the N2O cycle within the aquatic environment are nitrification and denitrification. Recent observations of significant nitrification in Antarctic sea ice shed a new light on nitrogen cycle within sea ice. It has been suggested that nitrification supplies up to 70% of nitrate assimilated within Antarctic spring sea ice. Corollary, production of N2O, a by-product of nitrification, can potentially be significant. Our recent studies in Antarctic land fast ice in McMurdo Sound, confirmed this suggestion, where N2O release to the atmosphere was estimated to reach 4µmol.m-2.yr-1. But this assessment is probably an underestimation since it only accounts for dissolved N2O while a significant amount of N2O is likely to occur in the gaseous form like N2, O2 and Ar. We will then address the new tools to measure the bulk concentration of N2O (dissolved and gaseous) in sea ice, and the production of N2O by sympagic microorganisms - what process is dominant and how much N2O is produced - based on the first time series of N2O measurement in sea ice. The determination of the isotopic composition of N2O using cavity enhanced laser absorption spectroscopy technique (Off-axis ICOS) will allow us to determine the origin of these processes. [less ▲]

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Peer Reviewed
See detailLanguage abilities in preterm-born children : Specific difficulties in phonological skills
Desmottes, Lise ULiege; Maillart, Christelle ULiege; VIELLEVOYE, Renaud ULiege et al

Poster (2017, July)

Children who were born prematurely (before 37 weeks’ gestation) are at greater risk for a range of impairments in cognitive, motor, social-emotional, and academic functioning (e.g., Bos et al., 2013 ... [more ▼]

Children who were born prematurely (before 37 weeks’ gestation) are at greater risk for a range of impairments in cognitive, motor, social-emotional, and academic functioning (e.g., Bos et al., 2013). Other developmental disorders, such as language delays and deficits, are also more common in preterm children (Van Noort et al., 2012). Because language function is essential in all kinds of social and academic life (Young et al., 2002), it is crucial to better identify and characterize language impairment in preterm-born children. Despite the large amount of research conducted on language abilities in preterm children, little is known about their phonological development (Barre et al., 2011). In the present study, we investigated differences in several phonological tasks between French-speaking premature children and in term-born control children. 30 children born at <35 weeks’ gestation (4 to 5 years old) and with low-birth weight (1215 g on mean) were recruited. These preterm children were matched to 30 children born at term on gender, chronological age and socio-economic level. All participants were administered five language tasks (phonemic discrimination, phonological judgment, pictures naming, pseudo-words repetition and phonological awareness) in order to precisely assess their phonological skills. Results indicated that preterm children presented poorer performance than control term-born children when they had to discriminate between different phonemes (phonemic discrimination abilities), to detect phonemic modifications (phonological judgment) and to recognize and identify syllabic segments (phonological awareness). Differences between both groups have also been observed in the quality of phonological representations (pictures naming task). However, both groups of children performed equally well in the pseudo-words repetition task. These findings revealed that preterm children score significantly lower compared with term-born children on several phonological tests, a language subdomain which is particularly important in the initial stages of language development and for reading. [less ▲]

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See detailLight Induced Super-Hydrophilicity in Niobium and Tantalum Oxides Thin Films
Henry, Théo ULiege; Bonsague, Fabio; Dubreuil, Olivier ULiege et al

Poster (2017, July)

Since its discovery at the end of the nineties by Wang et al.,[1] the interest for light-induced superhydrophilicity is ever growing. The application fields for materials displaying such a property are ... [more ▼]

Since its discovery at the end of the nineties by Wang et al.,[1] the interest for light-induced superhydrophilicity is ever growing. The application fields for materials displaying such a property are wide and numerous:[2] self-cleaning surfaces, anti-fogging, anti-bacterial, water and air purification, microfluidics…Nowadays, a research emphasis is on relatively low energy bandgap semiconductors, targeting a higher efficiency under solar irradiation or more precisely in the near UV and low-end of the visible spectral range. Here, however, we report UV-induced superhydrophilicity in metal oxides thin films showing a relatively high transparency in the UV. Reactive ion beam sputtering (IBS) was used to deposit niobium, tantalum and titanium oxides thin films with thickness ranging from 10 nm to 120 nm on fused silica substrates at room temperature. Contact angle measurements were performed for progressively increasing UV doses and also as function of elapsed time after the termination of the exposure in order to investigate the UV-induced hydrophilicity and recovery behavior of tantalum and niobium oxide thin films in comparison to that of titanium oxide deposited in analogous conditions. [less ▲]

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See detailLanguage and analogical reasoning in children with Specific Language Impairment: The effect of articulatory suppression
Krzemien, Magali ULiege; Thibaut, Jean-Pierre; Stoffels, Valentine ULiege et al

Poster (2017, July)

Analogical reasoning shares a mutual influence with language development: analogical reasoning is improved by labelling analogical items with words describing the relations that they contain. Conversely ... [more ▼]

Analogical reasoning shares a mutual influence with language development: analogical reasoning is improved by labelling analogical items with words describing the relations that they contain. Conversely, structural alignment, a core mechanism of analogical reasoning, allows the acquisition of novel words and the development of grammar (Gentner, 2010). Given those findings, some authors have taken interest in the analogical reasoning ability of children with language disorders, and specifically of children with Specific Language Impairment (SLI). Those children have worse performance than their age-matched peers without language disorders in linguistic or non-linguistic analogical tasks (Leroy, Maillart, & Parisse, 2014). Our aim here is to see if this weakness is due to their language disorders and if they use the same verbal strategies as their peers to solve an analogical task. To experience these assumptions, we use a perceptual analogical task following an A:B::C:D paradigm: participants have to find the relation between two geometric forms A and B and to apply it to the C term in order to find the D term among distractors. The distractors either share perceptual features with the C term, what creates a competition that shall be inhibited, or not. Moreover, children are faced with three interfering task conditions: one without any interfering task, one with an articulatory suppression secondary task and one with a tapping secondary task, which is used in order to measure the general dual task demands. Comparing the results of these conditions will allow us to evaluate the impact of language and verbal strategies on analogical reasoning in control and SLI children. [less ▲]

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See detailRepresentations about physical activity among firefighters. A study in Wallonie
Dubru, Gilles ULiege; Gribomont, Antoine; Cloes, Marc ULiege

Poster (2017, July)

Introduction To be a firefighter is a dangerous job. Many authors have found anxiety, stress, depression, sleep disorders, absenteeism and other deviant behaviors in this type of high-risk occupation ... [more ▼]

Introduction To be a firefighter is a dangerous job. Many authors have found anxiety, stress, depression, sleep disorders, absenteeism and other deviant behaviors in this type of high-risk occupation (Fullerton, Ursano & Wang, 2004 ; Carey, Al-Zaiti, Dean, Sessanna & Finnell, 2011 ; Elliot & Kuehl, 2007). Adopting an active lifestyle is therefore very important in reducing these health risks and thus maximizing the chances of staying healthy. It is for this reason that physical activity has an essential role for these people. According to this determining the place occupied by physical activity within the regional Walloon fire servicesseemed relevant. The first step should be to analyse the firefighters’ representations and lifestyle. Methods An online questionnaire (SurveyMonkey) was developed. It proposed a majority of closed-ended questions facing on age (38 ± 10.4 years), BMI (26.1 ± 3.7), gender (96.7% of men), rank, status (38.3% professional), PA representations and practices, well-being and self-esteem, job satisfaction, … We contacted one of the main firefighters association (FRCSPB) to reach a significant number of topics. 443 questionnaires were collected during a five weeks period. 394 were usable. 376 responses were needed to achieve a 95% confidence level with a 5% confidence interval based on all Belgian Firefighter. Results and discussion Results showed that firefighter showed positive representations about PA and were aware of the benefits of a regular practice on their health. Good stress management and cardiovascular endurance qualities were considerate as important in this profession. Nevertheless, subjects deplored a lack of maintenance of these qualities. The mean BMI of the subjects was above 26, indicating a slight overweight. Sedentary lifestyle, poor infrastructure, injuries due to lack of fitness allow us to suspect an insufficient training. Other factors were pointed out by the subjects (stress, absenteeism, deviant behavior…). Firefighters were generally satisfied with their job and considered that they have an acceptable quality of life. However lack of time, financial and human resources must not be a barrier to the practice of essential PA for those people who are directly related with danger. References Carey, M. G., Al-Zaiti, S. S., Dean, G. E., Sessanna, L., & Finnell, D. S. (2011). Sleep problems, depression, substance use, social bonding, and quality of live in professional firefighters. The international journal of occupational and environmental medicine, 53(8), 928-933. Doi: 10.1097/JOM.0b013e318225898f. Elliot, D. L., & Kuehl, K.S. (2007). The effects of sleep deprivation on firefighters and EMS responders: final report. International Association of fire Chiefs. Fullerton, C. S., Ursano, R.J.,& Wang, L. (2004). Acute stress disorder, posttraumatic stress disorder, and depression in disaster or rescue workers. The American Journal of Psychiatry, 161(8), 1370-76. [less ▲]

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See detailDispersion of Myzus persicae and transmission of Potato Virus Y under elevated CO2 atmosphere
Bosquée, Emilie ULiege; Boullis, Antoine ULiege; Bertaux, Morgane et al

Poster (2017, July)

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See detailAgency and delinquency among adolescence during their transition to adulthood: what role in the desistance process?
Puglia, Rosa ULiege; Glowacz, Fabienne ULiege

Poster (2017, June 31)

Recent studies have shown that agency plays an important role in the desistance process. This variable allows the transition from delinquent identity to non-delinquent identity. However, despite ... [more ▼]

Recent studies have shown that agency plays an important role in the desistance process. This variable allows the transition from delinquent identity to non-delinquent identity. However, despite increasing literature about this topic, there is a lack of consensus regarding the role of this variable in the desistance process. Also, the way to measure this phenomenon remains unclear. In our study, agency is thought within a border framework, namely the understanding of all kind of behavior. According to the social cognitive theory, emotional and cognitive processes influence human behavior: emotions and thoughts that will define ways of acting and will motivate behavioral changes. Outcomes expectancies can be help or hinder for the concretization of behavioral change. We conducted a qualitative research among adolescents (aged 17-18) who are engaged in a delinquent trajectory. Our objective are to understand how these young in transition to adulthood leave delinquent lifestyle by evaluating to their life course and delinquent course. Each participant was interviewed with a semi-structured interview. To ensure that the interviews provided rich insights into participants’ reality, the interview was designed to elicit detailed information on relevant themes including identity, turning point, future and delinquency trajectory. Desistance was not explicitly questioned. All interviews were taperecorded and analyzed using IPA method (Smith, 2003). Mastery Scale (Pearlin, 1978), Causal Attribution Scale (Rossier, 2002), Hope Scale (Snyder, 1991) and University Rhode Island Change Assessment Scale (McConnaughy, 1983) were also administered. We see that the younths interviewed are at different stage in their desistance process. All of them, persistent or desistant, consider taking a hold on their lives. These results encourage thinking agency in the understanding of all kind of behavior. We should then take into account the beliefs and expectations of results as a variable mediating the relationship between agency and desistance. [less ▲]

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See detailMean and variance of Dynamic Functional Connectivity in Parkinson’s Disease
Baquero Duarte, Katherine Andrea ULiege; Guldenmund, Pieter; Rouillard, Maud ULiege et al

Poster (2017, June 29)

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See detailThe dark matter disk: a viable explanation of the cosmic positron excess
Laletin, Maxim ULiege

Poster (2017, June 29)

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See detailHolomorphic cohomological convolution
Dubussy, Christophe ULiege

Poster (2017, June 28)

In his thesis, T. Pohlen succeeded in defining a Hadamard product between holomorphic functions defined on star-eligible subsets of the Riemann sphere. We show how this theory is actually a particular ... [more ▼]

In his thesis, T. Pohlen succeeded in defining a Hadamard product between holomorphic functions defined on star-eligible subsets of the Riemann sphere. We show how this theory is actually a particular case of the holomorphic cohomological convolution, defined in a general way thanks to the integration map on complex Lie groups. [less ▲]

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See detailMUNIX vs TASPM
BENMOUNA, Karim ULiege; MILANTS, Christophe ULiege; WANG, François-Charles ULiege

Poster (2017, June 27)

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See detailNF-kB-dependent regulation of TET1 in breast cancers
Canale, Annalisa ULiege; Collignon, Evelyne; Al Wardi, Clémence et al

Poster (2017, June 26)

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See detailQuality control of insulin formulations: API , protamine and aggregates follow-up
Demelenne, Alice ULiege; Napp, Aurore ULiege; Lamalle, Caroline et al

Poster (2017, June 21)

The prevalence of diabetes is increasing every year and insulin preparations are mostly prescribed for treatment of both type 1 and type 2 diabetes. Since these biopharmaceutical formulations are ... [more ▼]

The prevalence of diabetes is increasing every year and insulin preparations are mostly prescribed for treatment of both type 1 and type 2 diabetes. Since these biopharmaceutical formulations are expensive and require a prescription, they are an important target for counterfeiting in developing countries. Therefore, there is a need for fast and efficient methods for quality control of biopharmaceutical products such as insulin formulations. A fully validated micellar electrokinetic chromatography (MEKC) method was developed for quantification of human insulin and NPH insulin (insulin combined with protamine) in formulations. The BGE used was made of 50 mM ammonium acetate (pH 9.0), 20 mM Sodium dodecyl sulfate and 13 % (v/v) acetonitrile and samples were introduced at the short capillary end allowing a separation of insulin and two major excipients (phenol and m-cresol) within 3 minutes. This method was compared with HPLC method using a mobile phase composed of water with 0.1% formic acid / acetonitrile with 0.1 % formic acid in gradient mode. Secondly a MEKC method was also optimized to analyze protamine peptides in insulin formulations. The major protamine peptides could be separated using a BGE made of 100 mM phosphate buffer (pH 2) with 50 mM Thesit®. This method was used to check conformity of protamine in commercially available formulations. Finally, different approaches were investigated in order to follow insulin aggregation. Indeed, insulin is prone to unfold when submitted to denaturating factors as temperature, ionic strength, agitation and pH. An accumulation of unfolds protein in bloodstream results in a high tendency to aggregate and form amyloid fibrils. A deposit of those fibrils in the subcutaneous tissue leads to a complication called “insulin-derived amyloidosis”. On the other hand, during its production, insulin is often subjected to extreme conditions making aggregation, as well as protein stability, important parameters to be controlled during its quality control. In this study, insulin aggregates were generated after optimization of incubation conditions (pH, temperature, agitation…). Those aggregates were then analyzed by size-exclusion chromatography (SEC) and capillary electrophoresis (CE). We showed that capillary gel electrophoresis (CGE) is a promising technique to analyze covalent aggregates of insulin due to the fact that it separates the aggregates according to their size and not to their size/charge ratio. The use of a laser-induced fluorescence detector was also found attractive to enhance the sensitivity of the method. [less ▲]

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See detailRelease of Neutrophils Extracellular Traps as a main trigger for asthma onset
Radermecker, Coraline ULiege; Sabatel, Catherine ULiege; Toussaint, Marie et al

Poster (2017, June 20)

Allergic asthma is an important Th2 associated immunopathology. Even if the pathology of the disease is well described, its etiology is still largely unknown. Nevertheless, some environmental factors like ... [more ▼]

Allergic asthma is an important Th2 associated immunopathology. Even if the pathology of the disease is well described, its etiology is still largely unknown. Nevertheless, some environmental factors like viral infections and exposition to low doses of lipopolysaccharide (LPS) strongly increase the risk of disease inception. Interestingly, these two particular risk factors both induce a strong recruitment of neutrophils into the lung. Recently, scientists highlighted the ability of neutrophils to form neutrophils extracellular traps (NETs) composed of a network of extracellular DNA associated to anti-microbial peptides. NETs release (or NETosis) is an important component in organism defence against pathogen invasion but has also been identified as initiator of pathophysiological conditions like erythematous systemic lupus, gout and diabetes. In this study, we investigated the role of NETs as potential asthma inducers in specific pro-Th2 environmental risk factors like respiratory viral infections and low LPS doses exposures (also known as hygiene hypothesis). First, we assessed the correlation between respiratory viral infection or low LPS exposure and NETosis using western blot and confocal microscopy analysis. An influenza A infection induced a strong NETs release between day three and seven after viral inoculation whereas exposition to low (100 ng LPS) but not to high (10 µg LPS) LPS doses also promoted NETosis within 24 hours following the exposition. Then we developed two mouse models, a virus-induced asthma model and a model of asthma promoted by exposition to low LPS doses. In these models, only previously infected mice or mice exposed to low LPS doses displayed all the characteristics of allergic asthma following sensitization and challenge to house dust mite (HDM). The role of NETs in asthma onset was then demonstrated using three NETosis inhibitors (DNAse, Cl-amidine and inhibitor of neutrophil elastase) in our models as infected or low LPS doses exposed mice exhibited strong decreased of all key asthma features when treated with NETs inhibitors compared to non-treated mice. Finally, to address how NETs could lead to a TH2 immune response, we analysed by flow cytometry the distinct subpopulations of lung dendritic cells (DCs) in our two mice models. We observed, during the NETs release phase, a recruitment of monocytic derived DCs (moDCs). In conclusion, we have demonstrated an unexpected role for NETs in asthma onset by recruiting lung moDCs. [less ▲]

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See detailDEVELOPMENT OF A MULTISCALE CONVECTIVE LABSCALE DRYER
Fraikin, Laurent ULiege; Salmon, Thierry ULiege; Léonard, Angélique ULiege

Poster (2017, June 19)

The convective drying technology is currently used in many industries but the industrial process is frequently poorly mastered and some design security factors are used. The lack of optimized conception ... [more ▼]

The convective drying technology is currently used in many industries but the industrial process is frequently poorly mastered and some design security factors are used. The lack of optimized conception rules lead to large energy consumptions. In the same perspective, the use of superheated steam as drying fluid expands and requests the improvement of the knowledge about this specific drying process. For this goal, the PEP’s developed a new convective labscale dryer to conduct various studies. This article presents the new dryer called VESAC. [less ▲]

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See detailSTUDY ON THE STRUCTURAL EVOLUTION OF SEWAGE SLUDGE DURING CONVECTIVE DRYING
Li, Jie; Fraikin, Laurent ULiege; Salmon, Thierry ULiege et al

Poster (2017, June 19)

The structure of the sludge sample continues changing during drying as a result of the shrinkage phenomenon. Then the exchange area becomes smaller and the drying rate decreases. The sludge collected in a ... [more ▼]

The structure of the sludge sample continues changing during drying as a result of the shrinkage phenomenon. Then the exchange area becomes smaller and the drying rate decreases. The sludge collected in a wastewater treatment plant (Grosses Battes WWTP, Belgium) was chosen for both lab-scale experiment and pilot-scale experiment. X-ray macrotomography (resolution: 0.36 mm per pixel) and X-ray microtomography (resolution: 41 μm per pixel) were used to explore the structure evolution of the sludge bed and the single extrudate respectively. 2D cross-sections of the sludge bed and the single extrudate were acquired, which supply a convenient way to investigate the evolution of the structure. The results show that the structure of both the sludge bed and the single extrudate distinctly changes during the drying process. [less ▲]

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See detailMODELING MOISTURE TRANSFER OF MORTAR SUBMITED TO CONVECTIVE DRYING
Kahlerras, Loubna ULiege

Poster (2017, June 19)

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See detailOptimiaztion of an electrophoretic approach for the screening and the development of new antithrombotic drugs
Farcas, Elena ULiege; Bouckaert, Charlotte; Servais, Anne-Catherine ULiege et al

Poster (2017, June 19)

The discovery of lead compounds that can modulate the activity of a biological target is essential to provide efficient pharmacological tools and to serve as starting points for new drug generations ... [more ▼]

The discovery of lead compounds that can modulate the activity of a biological target is essential to provide efficient pharmacological tools and to serve as starting points for new drug generations. Fragment-based drug discovery (FBDD) approach is an attractive tool for the identification of new selective inhibitors of a target of interest, but its success largely depends on the ability to develop screening bioassays capable to detect and gauge weak affinity binders. To achieve this goal, we investigated capillary electrophoresis (CE) for identifying and ranking fragments from an initial library. Indeed, due to its ability to evaluate weak interactions, CE seems to be promising for fragment-based screening. This technique is a powerful analytical tool with a unique separation mechanism, speed, efficiency and versatility. Its main advantages are low protein consumption, higher throughput compared to NMR and X-ray crystallography and the fact that screening can be carried out using native protein in physiological solution without the need of immobilization. We developed a proof of concept study on thrombin, a serine protease implicated in the coagulation cascade using affinity capillary electrophoresis (ACE) for ranking fragments from an initial library. For this study, we followed a probe ligand, benzamidine, and we investigated interactions with the target by monitoring the changes of its electrophoretic mobility upon binding. The first step of this study consisted in the optimization of the experimental conditions suitable for the CE method (target and probe ligand concentrations, separation buffer composition, voltage, separation effective length, target partial filling…). Then, numerous thrombin inhibitors with a wide range of inhibitory potency (i.e. Ki 200 µM – 5 nM) were tested to validate our system demonstrating the possibility to fish binders in the optimized conditions. We also checked the absence of non-specific binding with the target using the inactivated enzyme at the binding site. It is noteworthy that in this operating system (ACE assay), binding occurs in free solution using physiological buffers, thus preventing artifacts that may result from target immobilization, which is a requirement for some techniques such as SPR. [less ▲]

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See detailDEVELOPMENT AND VALIDATION OF A FAST SFC METHOD FOR THE ANALYSIS OF FLAVONOIDS IN PLANT EXTRACTS
Huang, Yang ULiege; Jiang, Zhengjin; Fillet, Marianne ULiege et al

Poster (2017, June 18)

Flavonoids from plants always show a wide range of biological activities [1-2]. In the present study, a rapid and highly efficient supercritical fluid chromatography (SFC) method was developed for the ... [more ▼]

Flavonoids from plants always show a wide range of biological activities [1-2]. In the present study, a rapid and highly efficient supercritical fluid chromatography (SFC) method was developed for the separation of 12 flavonoids. After careful optimization, the 12 flavonoids were baseline separated on a ZORBAX RX-SIL column using gradient elution. A 0.1% phosphoric acid solution in methanol was found to be the most suitable polar mobile phase component for the separation of flavonoids. From the viewpoint of retention and resolution, a backpressure of 200 bar and a temperature of 40 °C were shown to give the best results. Compared with a previously developed reverse phase liquid chromatography method, the SFC method could provide flavonoid separations that were about three times faster, while maintaining good peak shape and comparable peak efficiency. This SFC method was validated and applied to the analysis of five flavonoids (kaempferol, luteolin, quercetin, luteoloside, buddleoside) present in Chrysanthemum morifolium Ramat. from different cultivars (Chuju, Gongju, Hangju, Boju). The results indicated a good repeatability and sensitivity for the quantification of the five analytes with RSDs for overall precision lower than 3%. The limits of detection ranged from 0.73 to 2.34 μg/mL, while the limits of quantification were between 2.19 and 5.86 μg/mL. The method showed that SFC could be employed as a useful tool for the quality assessment of Traditional Chinese medicines (TCMs) containing flavonoids as active components. [less ▲]

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See detailNorth and South: Simultaneous observations of both Jovian poles from Juno and the Hubble Space Telescope
Bonfond, Bertrand ULiege; Gladstone, George R.; Grodent, Denis ULiege et al

Poster (2017, June 15)

On its elongated orbit, Juno flies over the poles of Jupiter every 53.5 days. The few hours before and after the perijove offer unique opportunities to observe the whole polar region from close distance ... [more ▼]

On its elongated orbit, Juno flies over the poles of Jupiter every 53.5 days. The few hours before and after the perijove offer unique opportunities to observe the whole polar region from close distance. However, Juno’s instruments can only observe one hemisphere at a time. Fortunately, the Hubble Space Telescope points its 2.4 m mirror toward the opposite hemisphere during some of these time intervals, providing truly simultaneous observations of both poles. We compare observations from Juno-UVS with Far-UV imaging sequences from the Hubble’s Space Telescope Imaging Spectrograph (STIS). Juno-UVS acquires spectrally resolved images of 17 ms exposure every 30 s Juno spin in the 70-205 nm wavelength range, while STIS can acquire about 270 consecutive 10 s images per HST orbit in the 130-160 nm range, but without any spectral resolution. Despite some differences, these datasets are similar enough in terms of spectral coverage, temporal and spatial resolution to allow direct comparisons. On Jupiter, the magnetic field is highly asymmetric and displays significant localized anomalies. Furthermore, most processes leading to auroral emissions depend on the magnetic field magnitude, either in the equatorial plane, in the acceleration regions, or in the upper atmosphere. Investigating morphological and brightness discrepancies between the two hemispheres provides precious clues on the current systems flowing in the magnetosphere and on the charged particles acceleration mechanisms. [less ▲]

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See detailEnvironmental controls of biogenic volatile organic compound emissions from a grazed grassland in Dorinne, Belgium
Michel, Colin ULiege; Heinesch, Bernard ULiege; Bachy, Aurélie ULiege et al

Poster (2017, June 15)

Despite the growing interest for oxygenated volatile organic compounds (OVOC) over the last 15 years due to their role in the atmospheric chemistry, current knowledge about OVOC exchanges by grassland and ... [more ▼]

Despite the growing interest for oxygenated volatile organic compounds (OVOC) over the last 15 years due to their role in the atmospheric chemistry, current knowledge about OVOC exchanges by grassland and the environmental factors driving them still entails gaps. However, those ecosystems represent an important part of the total earth surface (13.37%). This study conducted on a grazed grassland therefore aims to quantify OVOC exchanges over full grazing seasons in order to understand the mechanisms behind these OVOC exchanges. The Eddy Covariance method was used for flux quantification, with a PTR-MS for the measurements of OVOCs mixing ratios. It took place within the activities of the CROSTVOC project (CROp Stress VOC) and therefore gives an important attention to the stress induced fluxes. BVOC flux measurements were also performed on a smaller scale by using all-teflon automated dynamic chambers covering a surface of 0.1 m² each. [less ▲]

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See detailHi-Fi simulation and teamwork training: what is it good for?
CARDOS, Benoît ULiege; GILLET, Aline ULiege; Ghuysen, Alexandre ULiege et al

Poster (2017, June 15)

Detailed reference viewed: 31 (1 ULiège)
See detailMechanochemical Unfolding of Artificial Helical Foldamers by Single-Molecule Force Spectroscopy
Devaux, Floriane ULiege; Li, Xuesong; Huc, Ivan et al

Poster (2017, June 15)

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See detailCharacterization of meat retail conditions in Kigali city (Rwanda): hygienic practices and determinants for Salmonella occurrence
Niyonzima, Eugene ULiege; Hategekimana, Jean Paul; Minani, Félicien et al

Poster (2017, June 14)

Salmonella is one of the leading bacterial food borne pathogens worldwide and meat constitutes one of the major vehicles for human Salmonella infections. Salmonella illnesses represent an important public ... [more ▼]

Salmonella is one of the leading bacterial food borne pathogens worldwide and meat constitutes one of the major vehicles for human Salmonella infections. Salmonella illnesses represent an important public health concern particularly in countries with growing economies such as Rwanda. The objective of this study was to characterize the retail conditions and to determine the microbiological quality and safety of meat retailed within the establishments of Kigali city. A survey was carried out in 150 establishments of Kigali city to characterize the meat retail conditions through a structured questionnaire, whereas 270 meat samples were analyzed for the enumeration of hygiene indicator bacteria and the qualitative detection of Salmonella by using conventional culture methods. Furthermore, the risk factors associated to the occurrence of Salmonella in the commercialized meat pieces were identified trough a binary logistic regression analysis. The first results from this study indicate that beef is the type of meat sold the most within retail premises of Kigali city and meat from animal species other than bovines are generally commercialized in large establishments. The levels of hygiene indicator bacteria were found to be relatively high and Salmonella was detected in 19.6% of all retailed meat samples. Factors such as the exposition of retailed meat at ambient temperature, the utilization of wooden cutting boards with rough surfaces which are difficult to sanitize as well as the lack of trained personnel in hygienic meat handling practices; were found to be significantly associated to the risk of Salmonella occurrence in the retailed meat. The findings from this study highlight the need for improvements in hygienic meat handling practices particularly in small and medium meat retail establishments in Kigali city [less ▲]

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See detailStudy of the regulation of β-lactam resistance in Enterococcus hirae
Raymackers, Alice ULiege; Maréchal, Maxime; Verlaine, Olivier ULiege et al

Poster (2017, June 13)

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See detailImpact of formulation and process parameters on near-infrared spectra: Application for water determination in biopharmaceuticals
Clavaud, Matthieu ULiege; Roggo, Yves; Allmendinger, Andrea et al

Poster (2017, June 11)

Traditionally, the water content of freeze-dried biopharmaceuticals is determined by time-consuming methods such as Karl Fischer titration. As a fast and non-destructive method, many studies demonstrated ... [more ▼]

Traditionally, the water content of freeze-dried biopharmaceuticals is determined by time-consuming methods such as Karl Fischer titration. As a fast and non-destructive method, many studies demonstrated the efficiency of Near-Infrared (NIR) spectroscopy for that purpose [1]. In this study, NIR was applied to different freeze-dried monoclonal antibody. The aim was to evaluate the robustness of a NIR model depending on formulation composition and process parameters of the lyophilization parameters, and the benefits of NIR when developing a freeze-drying cycle for a new pharmaceutical product. A full Design of experiments (DoE) was established in order to produce materials with various formulations and various process parameters. As a first step, a calibration model was created and validated. The model creation was based on 4 target lyophilized cycles which were manufactured to obtain samples with different water content concentration. Then, 20 lyophilized cycles were produced according to the DoE. Two levels of protein and sucrose concentration, and two levels of pressure / primary drying temperature and process time were investigated. Furthermore, several samples of each experiment stored at different temperature and relative humidity conditions were evaluated. Chemometrics using Principal Component Analysis (PCA) and Partial Least Squares (PLS) were used to evaluate the process variations and to determine the water content, respectively. NIR is capable to differentiate between different lyophilization process conditions, based on chemometrics. Robust calibration NIR model for water determination was generated against KF independent on lyophilization process parameters and formulation composition. NIR is suitable and robust method for drug product development of freeze-dried formulation. [less ▲]

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See detailMechanochemical Unfolding of Artificial Helical Foldamers by Single-Molecule Force Spectroscopy
Devaux, Floriane ULiege; Li, Xuesong; Huc, Ivan et al

Poster (2017, June 11)

Detailed reference viewed: 15 (1 ULiège)
See detailBio- and CO2-sourced polyhydroxyurethanes for hydrogels coatings, foams and high performance adhesives
Gennen, Sandro ULiege; Panchireddy, Satyannarayana ULiege; Grignard, Bruno ULiege et al

Poster (2017, June 09)

Due to concerns about global warming combined with the decrease of fossil resources, the chemical transformation of carbon dioxide (CO2) into added-value products has gained interest in both academic and ... [more ▼]

Due to concerns about global warming combined with the decrease of fossil resources, the chemical transformation of carbon dioxide (CO2) into added-value products has gained interest in both academic and industrial fields. Indeed, CO2 can be viewed as a cheap, non-toxic and renewable C1 building block precursor of sophisticated organic molecules and polymers. One representative example of CO2 transformation includes the synthesis of various (bis)cyclic carbonates via CO2/epoxide coupling.1-3 Bis-cyclic carbonates were then valorized as monomers for the synthesis of series of novel low carbon footprint poly(hydroxyurethane)s (PHUs). These polymers are now exploited to produce sustainable materials including foams for thermal insulation,4 hydrogels (for potential biomedical use)5 and high performance adhesives and glues (for metal, glass and wood). [less ▲]

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See detailCoherent backscattering of bosonic matter-wave in the presence of disorder and interaction
Chrétien, Renaud ULiege; Dujardin, Julien; Petitjean, Cyril ULiege et al

Poster (2017, June 09)

Coherent backscattering, which is an enhancement of the backscattered intensity of a light going through a medium made of point-like scatterers, is known as one of the most robust interference effects. It ... [more ▼]

Coherent backscattering, which is an enhancement of the backscattered intensity of a light going through a medium made of point-like scatterers, is known as one of the most robust interference effects. It has been shown, although it is nowadays not fully understood yet, that in the presence of non-linearities, this enhancement turns to an inhibition. We propose to study that effect by means of a system in which we study the transport of a Bose-Einstein condensate through Aharonov-Bohm rings in the presence of interaction and disorder. We find that our system is indeed a good candidate to observe the coherent peak’s inversion and is also suitable for more feasible theoretical calculations than in the original case. [less ▲]

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See detailSeparable states with infinitely many separable decompositions
Neven, Antoine ULiege; Bastin, Thierry ULiege

Poster (2017, June 09)

Despite intense effort in the past decades, developing a general criterion for identifying separable mixed states is still an open problem. In this context, the Positive Partial Transpose (PPT) criterion ... [more ▼]

Despite intense effort in the past decades, developing a general criterion for identifying separable mixed states is still an open problem. In this context, the Positive Partial Transpose (PPT) criterion constituted an important first step towards practical entanglement detection techniques and was later used to investigate the auxiliary problem of finding separable decompositions for separable states. In this poster, we use the rank diminishing method proposed by B. Kraus et al. [PRA 61, 062302 (2000)], that exploits the PPT property to reconstruct separable decompositions, to study the separable decompositions of symmetric PPT states of 3 qubits. We show that any 3-qubit symmetric product states always belong to an optimal separable decomposition of a PPT symmetric 3-qubit state with maximal birank. [less ▲]

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See detailDeformations of soap bubbles in a uniform electric field
Mawet, Sébastien ULiege; Caps, Hervé ULiege; Dorbolo, Stéphane ULiege

Poster (2017, June 09)

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See detailCharacterization of the pre-metastatic niche in lymph node, in experimental and clinical settings
Noël, Agnès ULiege; Balsat, Cédric; Garcia Caballero, Melissa et al

Poster (2017, June 08)

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See detailSeparation, identification and quantification of peptidoglycan fragments by zwitterionic hydrophilic interaction chromatography and capillary electrophoresis coupled to mass spectrometry
Boulanger, Madeleine ULiege; Delvaux, Cédric ULiege; Raymackers, Alice ULiege et al

Poster (2017, June 05)

Bacterial peptidoglycan-derived muropeptides and peptides are soluble fragments acting as messengers in diverse cell-signalling events. As the peptidoglycan wall is a key target of antibiotics, bacteria ... [more ▼]

Bacterial peptidoglycan-derived muropeptides and peptides are soluble fragments acting as messengers in diverse cell-signalling events. As the peptidoglycan wall is a key target of antibiotics, bacteria have developed specific resistance mechanisms based on the detection of these fragments inside their cytoplasm. In our model strain, Bacillus licheniformis, the peptidoglycan dipeptide m-A2pm-D-Glu triggers a beta-lactamase induction. However, the nature and the concentration of cytoplasmic peptidoglycan fragments leading to the dipeptide formation are unknown. Additionally, the muropeptides sensing is involved in the innate immune response toward bacterial invasion and is therefore of considerable importance in eukaryotes self-defence functions. In this context, the development of reliable analytical methods aiming to identify and quantify those fragments in complex samples are of major interest. [less ▲]

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See detailMass spectrometry imaging of small xenobiotics on Danio rerio : influence of molecular profiles modification as potential localization asset
Tiquet, Mathieu ULiege; Muller, Marc ULiege; De Pauw, Edwin ULiege

Poster (2017, June 02)

MALDI Mass spectrometry often fail to locate small xenobiotics present in low concentration in tissues due to ion suppression effect. This new method compare tissues of contaminated zebrafish to controles ... [more ▼]

MALDI Mass spectrometry often fail to locate small xenobiotics present in low concentration in tissues due to ion suppression effect. This new method compare tissues of contaminated zebrafish to controles with the statistical tool called receiver operating characteristic. Results cannot directly locate the xenobiotic but can indicate which tissues are affected by the contamination and thus give a hint on the biolocalization. [less ▲]

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See detailRôle des psychologues spécialisés en neuropsychologie auprès des patients en état de conscience altérée : état des lieux et perspectives
Wauquiez, Grégoire; Radiguer, François; Stephan, Julie et al

Poster (2017, June 02)

Avec les progrès des techniques de soins intensifs et de réanimation, de nombreuses personnes survivent à des lésions cérébrales graves et peuvent notamment présenter dans les suites un état de conscience ... [more ▼]

Avec les progrès des techniques de soins intensifs et de réanimation, de nombreuses personnes survivent à des lésions cérébrales graves et peuvent notamment présenter dans les suites un état de conscience altérée. La création depuis les années 2000 d’unités spécialisées dites “Etats Végétatifs Chroniques / Etats Pauci-Relationnels” témoigne du développement de l’offre de soin dédiée à ces problématiques complexes. De plus en plus d’études scientifiques sont également publiées chaque année sur le sujet de l’évaluation et de la prise en charge de ces patients (ref1). La question du diagnostic d'état d'éveil non répondant ou d'état de conscience minimale constitue entre autres un enjeu majeur pour proposer à ces patients une stimulation adaptée (ref2). Néanmoins, ce domaine d’intervention paraît aujourd'hui encore modérément investi par les psychologues spécialisés en neuropsychologie, professionnels qui semblent pourtant à même d’y contribuer de manière pertinente de par leurs connaissances et leurs compétences (ref3). Où en sont les pratiques sur le terrain et quelles seraient les perspectives de développement à envisager ? Pour tenter de répondre à ces questions, nous avons diffusé une enquête en ligne à destination des neuropsychologues francophones (Belgique, France, Québec et Suisse) en vue de recueillir des données sur la formation, les activités et les attentes de nos collègues. En parallèle, nous avons réalisé une brève revue de la littérature scientifique sur le sujet et sollicité l’avis d’experts concernant les pratiques et spécificités des neuropsychologues auprès de ces patients. Nos premiers résultats mettent en avant 1°) qu’un nombre non négligeable de psychologues spécialisés en neuropsychologie travaillent auprès de patients en état de conscience altérée, 2°) qu'ils ont des connaissances et une pratique spécifique leur permettant d'apporter un réel bénéfice dans le diagnostic et la prise en charge interdisciplinaire de ces patients, et 3°) que le sujet des états de conscience altérée mériterait une place plus importante dans la formation initiale et continue des neuropsychologues afin de contribuer au développement d’une pratique de haut niveau auprès de ces patients tout à fait particuliers. Ces résultats nous feront discuter des questions de la formation initiale, des variétés de pratiques et de la perspective d’une enquête élargie aux pays non francophones. [less ▲]

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See detailPensées défaitistes chez les personnes atteintes d'une schizophrénie et présentant des symptômes négatifs persistants
Thonon, Bénédicte ULiege; Laroi, Frank ULiege

Poster (2017, June 02)

Intro : Les symptômes négatifs de la schizophrénie, particulièrement ceux concernant le dé ficit motivationnel, sont associés à un faible fonctionnement quotidien. Ces symptômes se sont montré liés à des ... [more ▼]

Intro : Les symptômes négatifs de la schizophrénie, particulièrement ceux concernant le dé ficit motivationnel, sont associés à un faible fonctionnement quotidien. Ces symptômes se sont montré liés à des attitudes dysfonctionnelles, telles que les pensées défaitistes concernant l’atteinte de buts. Ce lien a été observé dans divers types d’échantillons, tant au cours des premières décompensations que dans la maladie chronique, mais non chez les personnes présentant des symptômes négatifs persistants (SNP). La présente étude vise à é valuer le lien entre les pensées défaitistes et les symptômes négatifs chez des personnes diagnostiquées avec une schizophrénie et des SNP. Un autre objectif est d’évaluer le lien entre la modification des pensées défaitistes et la réduction des symptômes négatifs après une intervention psychosociale. Méthode : Cinquante-et-un participants ont suivi l’intervention « Motivation and Engagement Training » pendant 9 mois. Ils ont été évalués avant et après l’intervention sur base des échelles suivantes : Negative Symptom Assessment (NSA), Brief Negative Symptom Scale (BNSS), Clinical Assessment Interview for Negative Symptom (CAINS), Defeatist Performance Beliefs. Résultats : En ligne de base, les pensées défaitistes n’étaient pas significativement corrélées aux symptômes négatifs, excepté au facteur Amotivation de la BNSS. La modification des pensées défaitistes s’est montrée cependant modérément et positivement corrélée au changement de l’amotivation mesurée par la BNSS (mais pas via les autres mesures). Discussion : Ces résultats soulignent la nécessité d’élargir les cibles des intervenions psychosociales à d’autres facteurs liés aux symptômes négatifs d’amotivation. [less ▲]

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See detailExploration des processus de recollection et de familiarité chez des patients présentant une plainte mnésique : Une étude longitudinale
Simon, Jessica ULiege; Collette, Fabienne ULiege; Salmon, Eric ULiege et al

Poster (2017, June 01)

Les données actuelles suggèrent une altération précoce de la recollection dans les premiers stades de la maladie d’Alzheimer. Par contre, aucun consensus n’a pu être dégagé concernant l’intégrité de la ... [more ▼]

Les données actuelles suggèrent une altération précoce de la recollection dans les premiers stades de la maladie d’Alzheimer. Par contre, aucun consensus n’a pu être dégagé concernant l’intégrité de la familiarité. En effet, certaines études suggèrent une altération précoce de ce processus, alors que d’autres montrent une préservation de celle-ci. Dans ce cadre, nous avons exploré l'impact du type de format de reconnaissance et du matériel sur la recollection et la familiarité chez des patients qui se plaignent de leur mémoire. Nous avons recruté 23 participants âgés contrôles, 9 patients présentant un trouble subjectif de la mémoire (SCI) et 23 patients présentant un trouble cognitif léger (TCL). Les participants ont réalisé une tâche de reconnaissance à choix forcé à deux alternatives et une tâche de reconnaissance Oui-Non incluant des images et des mots. Ces tâches étaient suivies d’une courte évaluation neuropsychologique. Quinze participants âgés contrôles et 23 patients ont participé au suivi, incluant une évaluation neuropsychologique, dans un délai moyen de 21 mois. Nos résultats montrent qu’à l’inclusion, les patients avec TCL avaient des performances moindres en reconnaissance que les deux autres groupes, qui ne différaient pas. De même, ces patients utilisaient moins efficacement la recollection et la familiarité par rapport aux contrôles et aux SCI, qui présentaient des performances similaires. Il n’y avait aucune interaction entre le groupe et le type de format ou le matériel. Lors du suivi, cinq patients avec TCL ont retrouvé un niveau d’efficience cognitive dans la norme et ont été considérés comme des SCI car les plaintes mnésiques étaient toujours présentes. Sur la base de l'adaptation française du test de rappel libre et indicé (RLRI-16), nous avons calculé une pente de déclin mnésique pour chacun de nos patients. Nous avons observé que les indices de recollection et de familiarité étaient expliqués par les pentes de déclin calculées sur le nombre total d’items rappelés librement. Ainsi, nous avons observé un déclin de la recollection et la familiarité dans le groupe de TCL mais pas dans celui des SCI, bien que les deux groupes se plaignent de leur mémoire. En outre, l'efficacité de la familiarité pourrait prédire un déclin cognitif futur. [less ▲]

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See detailEfficacité de la combinaison des méthodes explicite et implicite pour intervenir sur les difficultés morphosyntaxiques
Houben, Lauren; Maillart, Christelle ULiege; Leroy, Sandrine ULiege

Poster (2017, June 01)

Pour que la logopédie puisse s’appuyer sur une pratique basée sur les preuves (Evidence-Based Practice), il est nécessaire de disposer d’études traitant de l’efficacité des interventions. Dans la ... [more ▼]

Pour que la logopédie puisse s’appuyer sur une pratique basée sur les preuves (Evidence-Based Practice), il est nécessaire de disposer d’études traitant de l’efficacité des interventions. Dans la littérature scientifique, deux approches sont mises en avant pour pallier aux difficultés morphosyntaxiques: les méthodes implicites opposées aux méthodes explicites. Les méthodes implicites s’avèrent pertinentes chez les enfants d’âge préscolaire, en raison de leurs faibles habiletés métalinguistiques. Ces méthodes réfèrent aux méthodes de facilitation grammaticale (imitation, modelage, stimulation focalisée et reformulation) et à l’approche basée sur l’usage. Cette dernière tient compte de l’apprentissage progressif des différentes structures grammaticales chez les enfants ayant un développement typique (notamment Riches, 2013). Les méthodes explicites offrent un apprentissage explicite du langage. Elles reposent sur le constat selon lequel, en raison d’un déficit de la mémoire procédurale, les enfants ayant des troubles du langage ne parviendraient pas à apprendre implicitement le langage. Actuellement, les résultats obtenus quant à l’efficacité de ces méthodes semblent contradictoires. Dès lors, la combinaison des deux types d’approches pourrait être envisagée. Actuellement, une seule étude (Smith-Lock et al., 2013) s’est intéressée à cette combinaison des deux méthodes et a prouvé son efficacité. Bien que cette étude soit assez prometteuse quant aux bienfaits d’une rééducation s’appuyant sur plusieurs méthodes, des recherches complémentaires sont indispensables. [less ▲]

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See detailAnalyse des pratiques, des représentations et de la tolérance en matière de sexualité adolescente au regard de la consommation pornographique sur Internet
Garcet, Serge ULiege; Eloy, Noémie ULiege

Poster (2017, June 01)

L’hyper-sexualisation actuelle de l’espace public et la consommation de matériel pornographique semble avoir un impact sur le développement psycho-sexuel adolescent, la tolérance aux pratiques sexuelles ... [more ▼]

L’hyper-sexualisation actuelle de l’espace public et la consommation de matériel pornographique semble avoir un impact sur le développement psycho-sexuel adolescent, la tolérance aux pratiques sexuelles parallèles et l’expérimentation précoce et variée de ces pratiques. Différentes recherches ont été menées auprès d’un panel de plus de 300 adolescents. Les résultats, présentés en synthèses sous forme d’un poster, permettent de rendre une photographie actuelle des pratiques sexuelles adolescentes au regard de la littérature scientifique. Il apparait notamment que 80% des jeunes interrogés se disent consommateurs réguliers de contenus pornographiques. Cette consommation pornographique semble en lien avec le fait d’être plus ouvert aux questions en matière de sexualité, la diversification des pratiques sexuelles, le nombre de partenaires sexuels ou encore le recours à des relations alternatives de types « fuckfsriends » ou « sexting ». La mise en parallèle des pratiques adolescentes en matière de sexualité et de la consommation de pornographie internet a également permis de tenter de répondre à la double interrogation ; L’hyper-sexualisation de l’espace public augmente-t-il la tolérance des jeunes en matière de sexualité ? La pornographie internet influence-t-elle les représentations et pratiques des adolescents en matière de sexualité ? Par extension, cette compilation de résultats, nous a amené à envisager le lien existant entre la consommation précoce et accrue de pornographie chez les adolescents, leur seuil de tolérance aux différentes pratiques sexuelles mises en scène dans ces contenus et la propension que ces jeunes ont à expérimenter ces pratiques, parfois déviantes, au risque de s’inscrire dans la transgression. [less ▲]

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See detailThe acquisition of nouns in children with Specific Language Impairment
Krzemien, Magali ULiege; Thibaut, Jean-Pierre; Zghonda, Hela ULiege et al

Poster (2017, June 01)

Specific Language Impairment (SLI) is a neurodevelopmental disorder that affects the language development of children with a normal nonverbal intelligence and no history of neurological disorder nor ... [more ▼]

Specific Language Impairment (SLI) is a neurodevelopmental disorder that affects the language development of children with a normal nonverbal intelligence and no history of neurological disorder nor auditory deficit (Leonard, 2014). A difficulty linked to SLI is the poor language productivity and the input dependency that children display compared with their peers: they tend to use a limited variety of verbal forms compared to younger siblings (Conti-Ramsden & Jones, 1997) and use a high proportions of the same verbs as their mothers (Jones & Conti-Ramsden, 1997). Recent studies suggested that these disorders could be linked to a deficit in generalizing constructions (constructions being units of language that vary in complexity and abstractness, Tomasello, 2009) from the input (Leroy et al., 2013). Specifically, some authors proposed that children with SLI would need more exemplars to abstract a given construction from the input and apply it to new instances (Leroy et al., 2013). In this study, we want to broaden this assumption to the acquisition of words: we evaluated the ability of children with SLI to generalize novel words, and in particular relational words. SLI seem indeed to be linked to an impairment in the processing of relations: children with SLI have poorer performance than their age-matched peers in linguistic or non-linguistic analogical tasks, which require to reason about relational structures (Leroy et al., 2014). We draw the hypothesis that children with SLI would need more exemplars in order to generalize words compared to age-matched but also to language-matched peers. We created a novel word extension task to improve this hypothesis: the first part is composed with nine test trials, each associated with a non-word. The child sees one, two, or three exemplars of a novel noun in short animations. The examiner tells him: “This is a /dyfɑ̃/”. Then, the child sees three other animations and the examiner says: “Show me which one of these is a /dyfɑ̃/”. The child has to choose the object that plays the same role as the exemplars among two distractors: an object that looks like one of the exemplar and a non-related distractor. The second part of the task is based on the same protocol but the exemplars are objects that have a specific spatial configuration (like symmetry). Here again, the child sees one, two, or three exemplars of a novel noun associated with the objects. The examiner tells him: “This is a /fegɑ̃/”. Then, the child sees three other objects and the examiner says: “Show me which one of these is a /fegɑ̃/”. The distractors are an object that has the same global form as one of the exemplar but without having the specific configuration required, and the non-related distractor. The participants are 20 children diagnosed with SLI aged from 6 to 12 years-old. Each child is match to a control child in age and non-verbal IQ on the one hand, and to a control child in linguistic age (based on a measure of vocabulary comprehension). Results show that children are better able to extend relational words when presented with several referents of these words, which confirms what has already been found in other experiments (Gentner, 2005). When the feature to be used is a spatial relation between the parts of the objects, children with SLI have more difficulties than age-matched controls extending new words, which confirms that SLI is linked to an impairment in the processing of relations and a greater dependance on perceptual information (Leroy et al., 2014). They also tend to benefit more than age-matched children from the presentation of several referents of a new word in order to extend it, what would mean that they greatly benefit from comparison and variability in order to identify relational similarities. It would be interesting to see if children can learn from several items that relational feature can be pertinent to define categories and extend words, as young children without SLI can do it with shape while children with SLI cannot (Collinson et al., 2015). [less ▲]

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See detailAgression sexuelle lors d’un conflit dans les relations amoureuses : Un statut spécifique
Courtain, Audrey ULiege; Glowacz, Fabienne ULiege

Poster (2017, June 01)

Le CADRI (Conflict in Adolescent Dating Relationships Inventory ; Wolfe et al., 2001) est un questionnaire portant sur les fréquences de violence dans les relations amoureuses (VRA), dont la dimension ... [more ▼]

Le CADRI (Conflict in Adolescent Dating Relationships Inventory ; Wolfe et al., 2001) est un questionnaire portant sur les fréquences de violence dans les relations amoureuses (VRA), dont la dimension sexuelle. Il s’inscrit dans la continuité du CTS-2 (Conflict Tactics Scale ; Strauss et al., 1996) utilisé dans le cadre des violences conjugales, ces deux outils ayant été conçus sur base de la théorie du conflit. Or, celle-ci postule que « conflict is an inevitable part of human association, whereas violence as a tactic to deal with conflict is not. » (Strauss et al., 1996, p.284). Ainsi, agresser sexuellement sa petite amie ou son petit ami, est-ce du ressort d’un contexte conflictuel, ou bien de la violence sexuelle : quelle en est la spécificité ? Méthodologie : Deux versions du CADRI ont été administrées en passation groupale à des étudiants (N>200, 15-23 ans) en Belgique francophone : la première étant une version modifiée où la consigne introductive ne circonscrivait pas les items de violence à du conflit, la seconde étant la version-type délimitant les items de violence à un contexte de conflit. Résultats : Les scores diffèrent selon la version-type et la version modifiée du CADRI, et selon que nous nous situons sur le versant de la perpétration ou de la victimisation sexuelle, ainsi que selon le sexe des répondants. Discussion : Alors que l’importance des consignes introductives est globalement reconnue, l’implication conceptuelle de certaines est loin d'être négligeable pour la description, la compréhension et la prévention de l'agression sexuelle comme VRA. [less ▲]

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See detailHeritage mining landscapes as rural capital: the case of two heavy metals minings wastelands in Wallonia
Dubois, Charline ULiege; Vanderheyden, Vincent ULiege; Schmitz, Serge ULiege

Poster (2017, June)

For a long time and due to the socio-economic trauma caused by the closure of the mines, the hazards of abandoned sites and soil pollution, the newness of vestiges, or the symbol of the failure of an ... [more ▼]

For a long time and due to the socio-economic trauma caused by the closure of the mines, the hazards of abandoned sites and soil pollution, the newness of vestiges, or the symbol of the failure of an industrial development model, on-field industrial remains were not considered as valuable heritage, particularly in rural spaces. Indeed, in the dominant imagery of rural areas, industry and countryside do not fit together (Cloke et al., 1996; Edelblutte & Legrand, 2012). Yet, such industrial activities have a long history in some areas such as in rural East-Belgium. The past deindustrialization resulted in wastelands on which stakeholders have nowadays various interests. Some of these industrial wastelands try to become places of heritage preservation and valorisation (Fagnoni, 2003; Kitchen et al., 2006; Roth, 2007; Mitchell & O’Neill, 2016). In this paper, we consider industrial wastelands with the aim to develop and enhance rural development and heritage landscapes. The mining wastelands are defined as abandoned areas where old traces of mining (e.g. factories and buildings, cuts and fills material, other marks in the landscapes, polluted soils) are still present. These areas are waiting for a new evaluation in order to create rural development strategies and local projects. We study how to preserve and protect these authentic high value landscapes and what can be proposed as type of rural strategy and rural landscape management. How to reallocate the space of wastelands according to the valorisation of cultural and natural heritage? Through qualitative document analysis and stakeholders interviews, we are discussing on the basis of two case studies concerning heavy metals mines in Easten Belgium within an hour’s drive from Liège. The first case is the “Haldes calaminaires” area in Plombières (former lead and zinc mine) and the second one is the “Rouge-Thier” area in Stoumont (former manganese mine), both industrial wastelands in rural area with a real potential for rural development in some touristic, recreational, scientific, and pedagogical frameworks (Rosengarten, 2008; Dussart & Dussart, 1991). Different scenarios are possible to allow both sites to be recognized, saved, protected, enhanced, and developed for tourists and inhabitants, but they must confront the divergent heritage, cultural, biological, urban and socio-economic interests and issues of local and regional actors. [less ▲]

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See detailImpact of 3’-­‐sialyllactose and Bifidobacterium crudilactis on infant feces microbial composition and virulence modulation of Escherichia coli O157:H7, using the SHIME® gastrointes6nal model
Bondue, Pauline ULiege; Lebrun, Sarah ULiege; Crevecoeur, Sébastien ULiege et al

Poster (2017, June)

Bifidobacterium crudilactis, a bacterial species from bovine origin, growths on bovine milk oligosaccharides (BMO). Cell free spent media (CFSM) from B. crudilactis and 3’-sialyllactose (3’SL), a major ... [more ▼]

Bifidobacterium crudilactis, a bacterial species from bovine origin, growths on bovine milk oligosaccharides (BMO). Cell free spent media (CFSM) from B. crudilactis and 3’-sialyllactose (3’SL), a major BMO, modulated Escherichia coli O157:H7 virulence gene expressiona. In this study, the SHIME® gastrointestinal model was inoculated with 4 different treatments: 3’SL (ttm1), B. crudilactis (ttm2), 3’SL and B. crudilactis (ttm3) and CFSM from 3’SL and B. crudilactis culture (ttm4). In each section of the colon, samples were collected and analysed for short chain fatty acid (SCFA) concentration using HPLC, microbial populations using 16S rDNA metagenetic analysis and correlated with E. coli O157:H7 virulence gene expression. The results showed that SCFA levels were stable during the experiments. Metagenetic analysis showed a microbial diversity in transverse (TC) and descending colon (DC) close to feces, dominated by Bacteroides, Prevotella and Fusobacterium, while the ascending colon (AC) showed a different microbial diversity dominated by Veillonella. Ttm4 and ttm2 induced mainly a down-regulation of virulence genes: fliC in DC with ttm4, and luxS, stx1, qseA in AC, DC or TC with ttm2. Ttm1 also showed a down-regulation of fliC in DC, similar to the one observed with ttm4, but this was associated with an up-regulation of fliC and stx1 in AC or TC. Finally, ttm3 showed slight upregulation of ler, fliC and qseA in AC. These results show that ttm4 and ttm2 might have a positive effect against virulence expression of E. coli O157:H7. However, this trend has to be validated with the further replicates on the SHIME® system. [less ▲]

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See detailReal-time capture of the folding-unfolding transitions in a single oligorotaxane foldamer
Sluysmans, Damien ULiege; Hubert, Sandrine ULiege; Bruns, Carson et al

Poster (2017, June)

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See detail[18F]BPAM121: An AMPAR Modulator with Potential as a PET Probe
Manos-Turvey, Alexandra ULiege; Lemaire, Christian ULiege; Deverdenne, François et al

Poster (2017, June)

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See detailProfiling inferior left dorsal premotor cortex: when Area 55b meets Premotor Eye-Field
Genon, Sarah ULiege; Reid, Andrew; Langner, Robert et al

Poster (2017, June)

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See detailUnifying lesion masking and tissue probability maps for improved segmentation and normalization
Phillips, Christophe ULiege; LOMMERS, Emilie ULiege; Pernet, Cyril

Poster (2017, June)

Nowadays “Unified Segmentation” (US) is the usual approach to warp brain images into a standard reference space, i.e. perform spatial normalization, and derive posterior probability maps of the brain ... [more ▼]

Nowadays “Unified Segmentation” (US) is the usual approach to warp brain images into a standard reference space, i.e. perform spatial normalization, and derive posterior probability maps of the brain tissues, typically grey and white matter (GM, WM) and CSF [1]. US only relies on a spatial deformation model and prior ‘tissue probability maps’ (TPM) of the head tissues. When dealing with data from patients with focal brain lesions, e.g. tumors or multiple sclerosis (MS) lesion, the standard US approach does not work as it cannot account for the abnormal tissue distribution. A common work around is “cost function masking” (CFM) [2,3] where the abnormal tissues are masked out using a binary mask of the lesion [6,8]. Here we extend the US approach to provide a more principled solution for brain images with focal lesions. The aim is twofold: a more accurate warping into the reference space of the healthy tissues and a more precise delineation of the lesion(s). We modify the standard TPM adding a subject-specific ‘lesion probability map’ [5,7], by 1/ estimating a preliminary spatial warping from subject to the reference space with the CFM approach, then 2/ carefully updating the TPM with a new tissue class, the lesion, defined from the smoothed warped lesion mask and deciding which healthy tissue class can be affected by the lesion. The TPM-with-lesion is then fed into the US with the patients images, see Fig. 1. This “US-with-Lesion” (USwL) approach thus accounts for the presence of focal abnormal tissues in a probabilistic way, providing posterior probability maps of the tissues, including the lesion, and spatial deformation, accounting for the lesion. We tested and evaluated our USwL approach on 2 publicly available datasets: the BRATS [4] and the ‘MS lesion segmentation challenge’ (MSchal)[8]. The BRATS data include T1 and FLAIR images of 30 patients with gliomas and their annotated tumor mask (further considered as the ground truth). A rough lesion mask was manually built from the FLAIR image using MRIcron. USwL was used to segment T1 and FLAIR images along with this approximate mask. The GM, WM and CSF tissue classes could be affected by the lesion. The posterior probability map for the lesion tissue was cleaned up (preserving the bigger clusters) and thresholded. Overall the USwL improved (p<.05) the similarity of the lesion mask to the annotated tumor, in term of voxel matching (sensitivity, specificity & Jaccard coefficient). Synthetic lesioned brains were also generated to assess the quality of the deformation for the healthy tissues, indicating the superiority (p<.05) of the USwL compared to the standard approach. The MSchal data include T1, T2 and FLAIR images of 20 patients with MS as well as the manually annotated lesion (considered as only approximate here). USwL is applied on the 3 structural images with the lesion mask provided and with the constraint that only the WM is potentially affected by the lesion (as is plausible with MS). The thresholded posterior probability map for the lesion tissue was compared to the provided lesion mask. The USwL lead to more biologically plausible lesion volumes (p<.05), in term of volume compactness [10], see Fig. 2. The similarity of the warped posterior GM maps across the 20 subjects (expressed as the root-mean square difference to the mean of the 20 subjects) was also examined. The improvement, from using CFM-US to USwL, in the between-subject GM-matching is proportional (p<.05) to the actual WM lesion volume. We provide a new tool for US that allows to include focal lesions. Over the 2 dataset considered, USwL demonstrated improved performances compared to the standard US: 1/ a more accurate warping into the reference space of the healthy tissues and 2/ simply using an approximate mask, a more precise delineation of the lesion(s). The whole code will be made available as an SPM add-on toolbox (with a batch interface) on https://github.com/CyclotronResearchCentre/USwithLesion. [less ▲]

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See detailMicroplastics found in the stomach contents of Squalius cephalus from the Seine River
Collard, France ULiege; Gilbert, Bernard ULiege; Eppe, Gauthier ULiege et al

Poster (2017, June)

Microplastics (plastics < 5 mm) are emerging pollutants of growing concern. Since the 2000s their abundance, degradation and impacts on wildlife are more and more studied and understood. However, few data ... [more ▼]

Microplastics (plastics < 5 mm) are emerging pollutants of growing concern. Since the 2000s their abundance, degradation and impacts on wildlife are more and more studied and understood. However, few data are available particularly in freshwater ecosystems. Some fish species have plastic in their stomach contents such as: Gobio gobio, Alburnus alburnus, Leuciscus leuciscus while other species have not. In controlled conditions, microplastics were found to cause negative impacts in fish: leaching of micropollutants, endocrine disruption, hatching inhibition and decrease of growth rate of larvae. The first step in the understanding of these impacts is the quantification and the characterisation of ingested plastics by organisms in the field. Plastics and other anthropogenic particles (textile fibres) were isolated from 40 stomachs of Squalius cephalus (the European chub) collected in the Seine River (Paris) in August 2016. One station is upstream and the three others are downstream of the Paris Megacity conurbation. This megacity exerts a great pressure on the Seine River. Plastics were isolated thanks to a method using sodium hypochlorite and all particles were then analysed by Raman spectroscopy. The method consists in a degradation overnight of the organic matter in the stomach contents by sodium hypochlorite. This mixture is then filtrated and particles longer than 5 µm are resuspended into an ethanol (99%) solution for centrifugation. The precipitate, containing all particles denser than ethanol, is collected (1.3 ml) and spread on a mount for Raman spectroscopy. Several lasers were used, depending on the particle’s colour. Spectra were recorded with an accumulation ranging from 5 to 50s. Preliminary results showed that 7 individuals out of 25 already analysed (28%) had ingested at least one anthropogenic particle (AP). Eight APs were found and characterized, the majority of them (7) being dyed fibres. One of these fibres was made of a plastic polymer, the polyethylene terephthalate. The others were made of an undetermined material as Raman analyses gave only information on the dye. The eighth particle was a fragment of polypropylene. It is the first time that fish are studied as a part of plastic pollution in the Seine River. All isolated particles have been analysed leading to precise results. The percentage of occurrence is in the common range of other studies while much lower than the European flounder coming from the River Thames and higher than fish coming from Geneva Lake. It is not surprising that the majority of APs were fibres as another study in the river Seine found that the fibres concentration in water is far greater than the fragments concentration, as well as in urban runoff. It is also possible that the retention time of fibres in the gut is longer than fragments. Toxicological impacts of fibre ingestion is still unknown despite their ubiquity in many freshwater environments. [less ▲]

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See detailUntargeted serum metabolite profiling of colorectal cancer using GC-Orbitrap technology
Di Giovanni, Nicolas ULiege; Cojocariu, C; Silcock, P et al

Poster (2017, June)

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See detailThe Split-Band Interferometry Approach to Determine the Phase Unwrapping Offset
Libert, Ludivine ULiege; De Rauw, Dominique ULiege; d'Oreye, Nicolas et al

Poster (2017, June)

This poster presents an approach based on the Split-Band Interferometry to solve the ambiguities introduced during the phase unwrapping of separate regions.

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See detailNew data on the Mesozoic radiation of chelonioids
Scavezzoni, Isaure ULiege; Fischer, Valentin ULiege

Poster (2017, June)

"Turtles" (Testudines) form a successful group of reptiles with several terrestrial, marine and fresh-water species. Their peculiar and somewhat constrained morphology (i. e. : carapace incorporating ribs ... [more ▼]

"Turtles" (Testudines) form a successful group of reptiles with several terrestrial, marine and fresh-water species. Their peculiar and somewhat constrained morphology (i. e. : carapace incorporating ribs, curved limbs, anapsid skull exempt of temporal fenestrae) and ecology has often obscured their relationships and, hence, their evolutionary history, notably in marine turtles (chelonioids). Modern chelonioids are divided in two clades (i. e. : shoft-shelled turtles and hard-shelled turtles) supported by distinct morphological and embryological characters. Their origin is traced back up to the Cretaceous, along with a series of extinct forms, many of which being collectively known as Protostegidae. Fossil evidence show that at least five clades of marine turtles were roaming the seas at the end of the Cretaceous. In fact, chelonioids appeared during the first stages of the Early Cretaceous and quickly exploded to reach a high level of disparity at the lowermost part of the late Cretaceous. Therefore, the Mesozoic radiation of chelonioids must have happened during the "middle" Cretaceous (especially the Aptian-Albian interval). However this radiation is poorly understood as the phylogenetic relationships of marine turtles are not resolved yet. Bringing new data may help resolve these issues, and it is the exact reason why the genus Rhinochelys is being investigated. [less ▲]

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See detailSafety update on dapagliflozin (DAPA) across the phase 2b/3 clinical trial program
Jabbour, Serge; Seufert, Jochen; SCHEEN, André ULiege et al

Poster (2017, June)

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See detailMultimodal imaging analysis in Charles Bonnet Syndrome: a case report
Martial, Charlotte ULiege; Di Perri, Carol ULiege; Larroque, Stephen ULiege et al

Poster (2017, June)

Charles Bonnet syndrome (CBS) is a rare condition characterized by visual impairment associated with complex visual hallucinations in psychologically normal elderly people. Previous studies have suggested ... [more ▼]

Charles Bonnet syndrome (CBS) is a rare condition characterized by visual impairment associated with complex visual hallucinations in psychologically normal elderly people. Previous studies have suggested that visual hallucinations may be caused by brain damage in the visual system. However, in the case of CBS, specific brain regions in the occipital cortex have not been clearly determined and functional neuroimaging remains relatively unexplored. To our knowledge, functional connectivity by means of resting-state magnetic resonance imaging (MRI) has never been investigated in patients with CBS. We here aimed to investigate structural imaging, brain metabolism and functional connectivity in a patient with CBS. Resting-state functional and structural MRI were acquired in an 85-year-old patient with CBS and 12 age- and gender-matched normally sighted controls. Cognitive functioning was measured by behavioral assessment. A seed-based resting state fMRI was performed to investigate the default mode network (DMN), the executive control network and the visual networks connectivity. A voxel-based morphometry (VBM) analysis was employed to investigate the grey matter volume. Cortical and subcortical grey matter thickness were further investigated. Finally, 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) was also acquired to observe regional glucose uptake by comparing standard uptake values (SUVs). Increased functional connectivity was found between the DMN and the temporo-occipital fusiform cortex, as well as between the secondary visual cortex and the left frontal cortex, in the CBS patient compared to controls. The patient also demonstrated increased functional connectivity between the primary visual cortex and the left supramarginal gyrus and between the associative visual cortex and the superior temporal gyrus/angular gyrus, as compared to controls. Decreased grey matter volume was observed in the lateral occipital cortex/angular gyrus in our patient as compared to controls. Diminished grey matter thickness values were observed in the lateral geniculate nucleus compared to healthy controls. FDG-PET results confirmed previous work and showed bilateral hypometabolism in the occipital cortex (mean SUV reduction of 5.36%, p<0.001). Our results suggest that structural alterations in visual system in CBS are associated with compensatory/adaptive changes in functional connectivity that involve regions known to support hallucinations of faces in CBS patients. We suggest that this functional connectivity reorganization following visual structural damage may contribute to visual hallucinations. These findings might shed light on the pathophysiology underlining this rare condition. [less ▲]

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See detailExperimental design helps to optimize spray drying processes
Dellicour, Aline ULiege; Cloots, Rudi ULiege; Boschini, Frédéric ULiege

Poster (2017, June)

Experimental design is necessary to identify major experimental parameters linked to a process in order to optimize it and reduce costs. It also helps to reduce the number of experiments and analyze data ... [more ▼]

Experimental design is necessary to identify major experimental parameters linked to a process in order to optimize it and reduce costs. It also helps to reduce the number of experiments and analyze data statistically. This work aims to present some possibilities of how experimental design may be applied in the field of pharmaceutical powders production by spray drying. Depending on the application, powders need particular size, morphology, purity, crystallinity or polymorphism. All these characteristics may be influenced by process parameters and should be controlled to reach pharmaceutical requirements. [less ▲]

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See detailEvaluation of Non-negative matrix Factorization of grey matter in age prediction
Varikuti, Deepthi; Genon, Sarah ULiege; Sotiras, Aristeidis et al

Poster (2017, June)

Introduction: It has been shown that machine-learning methods applied to voxel-based morphometry (VBM) data allows the prediction of brain age [1]. Dimensionality reduction is a critical aspect of such ... [more ▼]

Introduction: It has been shown that machine-learning methods applied to voxel-based morphometry (VBM) data allows the prediction of brain age [1]. Dimensionality reduction is a critical aspect of such brain-based prediction of phenotypical characteristics to counter the curse of dimensionality associated with voxel-wise analysis. While previous age-predictions have employed PCA based compression, non-negative matrix factorization (NNMF) has recently been suggested as a plausible factorization of high-dimensional VBM data [4]. Non-negativity and sparsity of the components obtained from NNMF facilitate relatively more optimal solution than the PCA based compression [4]. Here, we evaluate, i) whether NNMF compression allows predictions of biological age that reproduce those from previously reported analyses [2], ii) the impact of the NNMF’s granularity on the prediction accuracy, iii) the possible effect of the factorizations derived from different datasets on the prediction, and iv) whether explicit adjustment can address the model bias inherent to many brain-based predictions. Methods: VBM8 preprocessing (using only non-linear modulation and 8 mm FWHM smoothing [3]) was used to compute voxel-wise GM volumes for two datasets, 1) 693 healthy older adults (age: 55-75 years) scanned at a single site (“1000BRAINS) [1], 2) 1084 healthy adults (age: 18-81 years), scanned at multiple sites (“Mixed”) (Fig 1A). NNMF solutions for both groups were derived at different levels of granularity. Age prediction was performed by fitting LASSO regression models either on the coefficient matrix from the respective NNMF or by those that were derived from projecting a group’s data on the respective other groups components. Model generalization was evaluated by 10-fold cross-validation replicated 25 times. To address the known bias towards the mean, i.e., overestimation of young and underestimation of older subjects, we additionally tested models that explicitly fitted the regression-slope between the real and predicted training set and used this to adjust the expected slope of the test set to 45 degrees. Results: In both datasets, NNMF components resembled neurobiologically reasonable patterning of the brain (Fig 1B). Prediction accuracy based on the projection of data on the components from either group was virtually identical (Fig 2A). For both datasets, mean absolute errors (MAE) declined with higher granularity of the components and reached values well comparable to previous approaches even when using components derived from an independent sample (MAE: 3.6 years for 1000BRAINS; 6.4 years for Mixed). Plotting the prediction error relative to the biological age of the subjects revealed the bias towards the mean across both datasets (Fig 2B). Adjusting for the slope estimated in the training set allows removing this bias, though it needs to be noted that this comes at the cost of reduced precision, i.e., unbiased estimates yield a slightly higher MAE. Conclusion: NNMF allows the definition of co-variation patterns in VBM data. Due to the non- negativity and sparseness, NNMF enable substantially easier and higher biological interpretation than other methods for data compression such as PCA [4]. We showed that NNMF compression of VBM data over the lifespan allows predicting previously unseen subjects’ age with a precision that is comparable to earlier reports using PCA for data compression [2], while offering the potential for neurobiological interpretation. Importantly, accuracy seems to be independent of whether the components were derived from the same dataset or from a dataset that is not only independent but also different in age distribution. We note that accuracies tend to continuously decrease with higher granularity, although performance tends to plateau at about 300 components. Finally, adjusting the inherent bias of sparse regression models yields unbiased out-of-sample predictions but comes at the expense of slightly higher mean errors. [less ▲]

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See detailQuantification of roots by the use of NIR hyperspectral imaging and chemometrics
Eylenbosch, Damien ULiege; Baeten, Vincent; Bodson, Bernard ULiege et al

Poster (2017, June)

Roots, the belowground part of plants, play a major role in plant development. Their study in field conditions is important to identify suitable soil management practices for suitable crop production but ... [more ▼]

Roots, the belowground part of plants, play a major role in plant development. Their study in field conditions is important to identify suitable soil management practices for suitable crop production but roots are hidden by soil and their study is therefore difficult. Estimation of root system development is often based on the soil coring method which allows repeated measurements during the growing season in the field as well as in different soil horizons. However, this method is limited due to the time needed to extract roots from soil cores and to manually sort them from crop residues before quantification. To avoid this tedious sorting step and remove operator subjectivity, a faster sorting method was developed. Near infrared hyperspectral imaging (NIR-HIS) was tested as a rapid method to quantify the amount of roots in soil samples. [less ▲]

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See detailSeparation of FLEC diastereomers by CE vs. LC approaches in the context of neurometabolomics
Moldovan, Radu-Cristian ULiege; Bodoki, Ede; Servais, Anne-Catherine ULiege et al

Poster (2017, June)

Some of the D-amino acids (D-Ser, D-Asp, D-Glu) have gained an increasing attention during the last decades, due to the discovery of their role as neurotransmitters and their implication in different ... [more ▼]

Some of the D-amino acids (D-Ser, D-Asp, D-Glu) have gained an increasing attention during the last decades, due to the discovery of their role as neurotransmitters and their implication in different neurological pathologies (Alzheimer’s disease, schizophrenia etc.). Nevertheless, their use as biomarkers is particularly relevant when correlated with the levels of other neurotransmitters. In order to develop a fast and efficient separation method widely accessible for the quantitation of these molecules, we used only common separation tools such as RP-18 stationary phases for reversed phase liquid chromatography (RP-LC) or bare fused capillaries for capillary zone electrophoresis (CZE). For achieving chiral resolution, a derivatization procedure was implemented. (-)-FLEC was the chiral derivatization agent of choice due to its fast and quantitative reaction with primary and secondary amines and the ability of performing in-capillary derivatization. Moreover, the derivatization process implies only a simple mix of the sample and reagent, at room temperature. The separation of the FLEC derivatives of several biologically relevant D- and L- amino acids (Asp, Glu, Ser, Tyr, Trp, Phe, His) together with certain neurotransmitter molecules have been optimized using CZE or RP-LC, chiral resolution being achievable for all amino acids of interest. By the CZE approach the running buffer’s pH turned out to be critical in achieving baseline separation of the targeted analytes. The derivatives of most amino acids could be separated using 60mM acetate buffer at pH 5, while for Asp derivatives the separation could be achieved only at pH 4. Being stronger bases, a third run at a more alkaline pH was needed for the separation of the remainder neurotransmitters. Moreover, the implemented in-capillary derivatization allows a fast and fully automated separation procedure. As for the RP-LC approach 50 mM acetate buffer in combination with an organic modifier (methanol, acetonitrile or tetrahydrofuran (THF)) was tested as mobile phase using gradient elution. Once again, the strong influence of pH on the resolution was observed. The organic modifier nature was of critical importance, where only THF enabled baseline resolution for all amino acid derivatives. [less ▲]

Detailed reference viewed: 31 (7 ULiège)