References of "Poster"
     in
Bookmark and Share    
Peer Reviewed
See detailHolocene paleoclimate reconstructions from belgian continental archives
Allan, Mohammed ULg; VERHEYDEN, sophie; CRUCIFIX, Michel et al

Poster (2016, June 28)

Speleothems and peatbogs presented in Belgium are interesting archives for atmospheric pollution record and climate variability. Both archives are reliable continental environmental archives of high ... [more ▼]

Speleothems and peatbogs presented in Belgium are interesting archives for atmospheric pollution record and climate variability. Both archives are reliable continental environmental archives of high interest due to their dating possibilities and their possibility to preserve multi-proxy records of environmental and climatic dynamics. Combining studies on speleothems and peatbogs from the same area will provide an age-constrained reconstruction of climatic variability at annual resolution for key intervals of the Holocene. The reconstructed precipitation and temperature curves in NW European settings, as proposed in HOPES, are essential to better constrain the Northern Hemisphere climatic record and to test climate models. Our strategy is derived from a comparative study of two continental archives speleothems and peatbogs. Time series of elemental and stable isotope geochemistry will be established for the 2 archives. For peatbog, the reconstructions of temperature (derived from stable C and O isotope), precipitation (derived from humification) and dust flux (from elementary geochemical signature) would track climate changes with subdecadal resolution. As an innovative part, Laser Ablation analyse of elemental geochemistry on impregnated peat section will allow to reach an annual resolution in the dust flux. For speleothems, records of temperature (derived from oxygen and carbon isotopic composition of calcite) and effective rainfall (derived from geochemical ratios) would reach a seasonal resolution. [less ▲]

Detailed reference viewed: 36 (3 ULg)
Full Text
Peer Reviewed
See detailMOISTURE CONTENT DETERMINATION OF FREEZE-DRIED PRODUCTS BY NEAR-INFRARED SPECTROSCOPY: A CASE STUDY FOR UNIVERSAL REGRESSION MODEL
Clavaud, Matthieu ULg; Roggo, Yves; Degardin, Klara et al

Poster (2016, June 06)

Karl Fischer titration is the reference method for moisture content determination in the pharmaceutical industry. Near-infrared spectroscopy is considered the most suitable alternative technique. Indeed ... [more ▼]

Karl Fischer titration is the reference method for moisture content determination in the pharmaceutical industry. Near-infrared spectroscopy is considered the most suitable alternative technique. Indeed, NIRS is a safe and fast method which does not require sample preparation. Nevertheless, the development and validation phases are time-consuming. In addition, the NIRS methods presented so far were mostly product specific. The main objective of this study is to highlight that an universal calibration model can be validated for several freeze-dried products in order to speed up the validation time. This objective was led in two steps. A universal model was first evaluated. A calibration set and a validation set were built up with three freeze-dried products. An antibody drug conjugate, a large molecule and a small molecule all packed in sealed vials were used to introduce more variability. Regression methods were then compared in order to optimize the prediction values. [less ▲]

Detailed reference viewed: 42 (6 ULg)
Full Text
Peer Reviewed
See detailLes problématiques de la rénovation du stock bâti dans la ville de demain : résultats d’une étude initiale en Belgique.
Ruellan, Guirec ULg; Attia, Shady ULg

Poster (2016, May 25)

Pour atteindre les objectifs énergétiques de l’Union Européenne pour 2050, et plus largement les objectifs fixés à la dernière COP, le secteur de la construction et de l’habitat doit opérer sa mue vers un ... [more ▼]

Pour atteindre les objectifs énergétiques de l’Union Européenne pour 2050, et plus largement les objectifs fixés à la dernière COP, le secteur de la construction et de l’habitat doit opérer sa mue vers un modèle plus durable. En Belgique, cela passe par la rénovation et l’amélioration des performances du stock bâti existant. La présente étude porte sur l’identification des différents enjeux (environnementaux, économiques et sociaux) liées à la rénovation en Belgique et tente d’objectiver les barrières (de financement, de communication et de réglementation) à une augmentation du taux de rénovation, à travers une revue de littérature des différentes études et projets portant sur ce domaine en Belgique. Ces résultats initiaux devront permettre ultérieurement la conduite des recherches approfondies visant à la modélisation des effets de plusieurs stratégies possibles d’augmentation du taux de rénovation. [less ▲]

Detailed reference viewed: 16 (3 ULg)
Peer Reviewed
See detailAbnormal bodily experiences in schizophrenia: a phenomenological study
lancellotti, Elisa; Englebert, Jérôme ULg

Poster (2016, May 24)

Our study focuses on Abnormal Bodily Experiences [ABE] in people with schizophrenia. We have created a specific questionnaire for this study – based on the study of Stanghellini et al. (2012) and the ... [more ▼]

Our study focuses on Abnormal Bodily Experiences [ABE] in people with schizophrenia. We have created a specific questionnaire for this study – based on the study of Stanghellini et al. (2012) and the third dimension of the EASE scale (body experiences) (Parnas et al. 2005). Our research follows an analytical method called “empirical-phenomenological”. Our population is made up of 50 schizophrenic subjects. The average age of subjects was 37 years. There are no exclusion criteria regarding gender or control sample. Analyzes are qualitative. We observed that ABE are very present symptoms in people with schizophrenia. Indeed, in our sample, only one patient was asymptomatic. We also observed that all categories and subcategories were present in our sample. These results should help to refine and clarify the diagnosis of schizophrenia and open up significant opportunities for psychotherapeutic dimension. [less ▲]

Detailed reference viewed: 21 (2 ULg)
Peer Reviewed
See detailMaternal sense of competence in a context of precariousness
Halin, Stéphanie ULg; Glowacz, Fabienne ULg

Poster (2016, May 24)

The exercise of parenthood is threatened by the precarious context in which parents and children live. Precariousness is defined by the lack or the absence of basic securities, such as housing, employment ... [more ▼]

The exercise of parenthood is threatened by the precarious context in which parents and children live. Precariousness is defined by the lack or the absence of basic securities, such as housing, employment, financial, emotional security, etc. In such a context, the emotional availability of a parent can be reduced, so that the quality of parent-child interactions decreases and multiple dimensions of the child development are impacted. Therefore, policies of prevention and intervention have been developed in order to overcome the difficulties experienced by parents from birth and, sometimes, from pregnancy. However, little is known about the parenting sense of competence of mother living in such a precarious context, and the possible mediating effect of perceived social support. In this study, we investigate parenting sense of competence in a sample of 38 adult mothers raising alone their children in a context of poverty. Subjects completed the French versions of the “Parenting Sense of Competence Scale (P.S.O.C.)” and the “Social Provisions Scale”, and a socio-demographic questionnaire. Results indicate that, in average, mothers report a high parenting sense of competence (μ=69.18), characterized by a high level of self-efficacy (μ=32.76) and an average level of satisfaction (μ=36.42). Mothers also report low perceived social support (T=41, percentile 21). Results also indicate a significant negative correlate between self-efficacy and the need to feel useful and necessary, while the satisfaction dimension is positively correlated with all the perceived social support dimensions, except from the “need to feel useful” dimension. In conclusion, mothers raising alone their children in a context of poverty report high levels of parenting sense of competence. However, withdrawal and isolation are associated with poorer parental satisfaction. This suggests that the social dimension of poverty is a significant aspect to consider in parenting support policies. [less ▲]

Detailed reference viewed: 9 (1 ULg)
Peer Reviewed
See detailA phenomenological approach of anorexia nervosa
Minguet, Eugénie; Englebert, Jérôme ULg; Helinski, Adam et al

Poster (2016, May 24)

Introduction: from a phenomenological perspective, anorexic female patients seem to experience difficulties regarding the subjective feeling of their own body (embodiment) and their personal identity ... [more ▼]

Introduction: from a phenomenological perspective, anorexic female patients seem to experience difficulties regarding the subjective feeling of their own body (embodiment) and their personal identity, which lead to an intersubjectivity impairment within social interactions. Following these findings, this study investigates the “body-for-others” concept (Sartre, 1943) and altruistic hypotheses from the ethologist Albert Demaret (1973) in a sample of anorexic female patients. Two main hypotheses are tested: anorexic patients are expected to define themselves mostly through the gaze of others and as more altruistic than control participants. Method: this study included 67 anorexic female patients (based on the DSM-IV criteria) and 246 control female participants. Three self-reported questionnaires were used: the Eating Disorder Inventory: EDI-II of Garner (French version), the Identity and Eating Disorders questionnaire: IDEA of Stanghellini (French version translated and adapted by us) to assess the “body-for-others” concept and 17 complementary items for the altruistic dimension. Mann-Whitney non-parametric tests were used to compare the two groups. Results: results show that anorexic patients obtain higher scores than the control group for the three questionnaires (p<0,001 for all measurements). Discussion: the IDEA questionnaire enriches the knowledge relative to the body-self relationship and the first-person perspective, which is essential for a phenomenological approach. Furthermore, the promising results concerning the altruistic dimension in anorexia nervosa should be evaluated in future research. Nevertheless, a better validity of the items assessing the altruistic dimension is needed. [less ▲]

Detailed reference viewed: 31 (2 ULg)
Full Text
Peer Reviewed
See detailWould you care for some integrated care in your fragmented health system? A participatory action research to improve integration between levels of care in a Belgian urban setting.
Belche, Jean ULg; Duchesnes, Christiane ULg; Darras, Christian et al

Poster (2016, May 24)

Integration between levels of care is not facilitated by the Belgian health system. Indeed, patients have uninhibited access to every level of care, there is no gatekeeping system, and no structural ... [more ▼]

Integration between levels of care is not facilitated by the Belgian health system. Indeed, patients have uninhibited access to every level of care, there is no gatekeeping system, and no structural coordination between levels of care. Meanwhile, on one hand, the occurrence of more complex care situations in the ambulatory setting is enhancing the need for coordination while on the other hand, hospitals face financial constraints to provide care in the community. The aim of the research was to organize coordination between levels of care at the local level, in an urban setting. We used the “Local Health System” model (LHS) that aims at integrating hospital and primary care activities for a defined population at the local level. We chose the participatory action research (PAR) methodology and its spiral plan-do-study-act cycles, to ensure the participation and implementation of results by the targeted actors (hospital and local general practitioners (GP) organizations). [less ▲]

Detailed reference viewed: 25 (4 ULg)
Peer Reviewed
See detailHéboïdophrenia: The hazardous interplay of psychosis and psychopathy
De Page, Louis; Englebert, Jérôme ULg

Poster (2016, May 24)

Introduction The diagnostic entity of heboidophrenia has been consigned to oblivion despite its clinical, prognostic, criminogenic value. At the core of this diagnosis lies specifics interactions between ... [more ▼]

Introduction The diagnostic entity of heboidophrenia has been consigned to oblivion despite its clinical, prognostic, criminogenic value. At the core of this diagnosis lies specifics interactions between psychosis and psychopathy. The diagnosis was first coined by Kalhbaum in 1890, was revived by Anglo-Saxon literature in the first half of the 20th century, and by French psychiatrists in the late 90’. Method We integrated literary sources, clinical experience and an own pilot study as a stepping-stone for a more in-depth research. Cases (n=20) were selected out of samples of Mentally Disordered Offenders in Belgian Medium and High Risk Forensic Facilities. Files, records and therapist’s experiences were quantitatively analysed iteratively to cull subtypes from each other. We here present preliminary qualitative results, more indepth qualitative and quantitative results will be produced. Results The diagnosis subsumes more than a mere DSM-IV-TR Axis I & II comorbidity, it can be seen from a developmental perspective, or from a structural perspective. Both vantage points suggest an interplay between the (paranoid) psychotic process and the antisocial behaviour, where both trigger and induce each other. At this point, we found evidence for three subtypes modes of interplay; 1) mood instability patterns induced either psychopathic or psychotic phenotypic presentation, 2) according to personality organization and its defensive functioning (were psychopathy defends against psychosis), and 3) phenotypic expression of both components (psychopathy and psychosis) linearly co-dependent. Discussion Despite its incremental value, little is known about the therapeutic prospects of this diagnosis. Current results indicate that these patients do question competency to answer for their deeds in a peculiar manner, relapse more often, reoffend more often, do evade treatment opportunities (if they have any), act out more often (in both antisocial and psychotic ways), induce a particular negative counter-transference in psychiatric teams, etc. Because of these particularities and their versatile phenotype presentation, heboidophrenia patients cannot simply be assimilated to the “high risk & high care” population, but need special supervision and clinical insight. In this research, we aim(ed) at discerning semiologic signs in order to support the diagnostic process. [less ▲]

Detailed reference viewed: 29 (1 ULg)
Peer Reviewed
See detailIntimate partner violence: Perseverance vs Dropout from treatment programs targeting male batterers
Di Piazza, Laetitia ULg; Kowal, Cécile; Hodiaumont, Fabienne et al

Poster (2016, May 24)

Introduction: The Dropout phenomenon has been studied extensively in general psychotherapy and in more specific domains. Therapeutic programs for male batterers across Europe, United States or Canada also ... [more ▼]

Introduction: The Dropout phenomenon has been studied extensively in general psychotherapy and in more specific domains. Therapeutic programs for male batterers across Europe, United States or Canada also have their share of problems in their attempts to maintain users in treatment. The purpose of this study is to identify potential intrapsychic variables associated with dropout and completion of this kind of treatment. Method: Fifty one male offenders enrolled in a group treatment for domestic violence took part in the study (23 who abandoned and 28 who completed). Before the start of therapy, they were surveyed using questionnaires and structured clinical interview to collect sociodemographic data and to assess specific psychological variables, namely emotional distress (BDI), impulsive behavior (BIS-11), early relationship with their parents (PBI), life events (LEDS) and alexithymia (TAS-20), the inability to experience and express subjective emotions. Results: Correlational analysis showed that age, paternal parenting behaviors and the number of significant events reported in the past six months are the only variables correlated with treatment dropout. The younger the participants, the most likely they were to dropout of the group therapy. Moreover, men who completed treatment reported fewer difficulties in their life and less autonomy support by their father than men who prematurely terminated their therapy. Discussion: The present findings pose a serious challenge for all actors involved in specifics treatment programs. Indeed, if all individuals who committed violent acts have the same intrapsychic variables, how do we predict, especially retain and motivate, the users likely to dropout? [less ▲]

Detailed reference viewed: 12 (1 ULg)
Full Text
See detailPeptidoglycan fragments separation by CE/LC-MS
Boulanger, Madeleine ULg; Delvaux, Cédric ULg; Far, Johann ULg et al

Poster (2016, May 24)

In Bacillus licheniformis 749/I, the induction of BlaP beta-lactamase relies on a complex regulation system. During this process, the intracellular repressor BlaI is inactivated by a dipeptide coming from ... [more ▼]

In Bacillus licheniformis 749/I, the induction of BlaP beta-lactamase relies on a complex regulation system. During this process, the intracellular repressor BlaI is inactivated by a dipeptide coming from the peptidoglycan (PG) degradation via an “AND Gate” regulation. This regulation involves the cellular stress induced by the beta-lactam, the membrane receptor BlaR1 and the PG turnover. Briefly, the induction occurs when the extracellular domain of BlaR1 is acylated by the antibiotic which leads to a reorganization of the transmembrane segments and the receptor autocleavage. Simultaneously, the beta-lactam partially inhibits the penicillin-binding protein 1 (PBP1), triggering increased PG turnover and accumulation of PG fragments. Some of these fragments could enter in the cytoplasm and undergo enzymatic degradations which lead to the formation of the pro co-activator (tripeptide L-Ala-D-Glu-m-A2pm). This pro co-activator generates the co-activator, the dipeptide D-Glu-m-A2pm. Nowadays the nature and the concentration of PG fragments inside the cytoplasm are unknown. Therefore, the development of different analytical methods is required in order to identify those cytoplasmic fragments. In this poster, three different ways to separate PG fragments are discussed. [less ▲]

Detailed reference viewed: 29 (3 ULg)
Full Text
See detailImproving pose estimation by building dedicated datasets and using orientation
Azrour, Samir ULg; Pierard, Sébastien ULg; Van Droogenbroeck, Marc ULg

Poster (2016, May 19)

Markerless pose estimation systems are useful for various applications including human- computer interaction, activity recognition, security, gait analysis, and computer-assisted medical interventions ... [more ▼]

Markerless pose estimation systems are useful for various applications including human- computer interaction, activity recognition, security, gait analysis, and computer-assisted medical interventions. They have attracted much interest since the release of low-cost depth cameras such as Microsoft’s Kinect camera. Shotton et al. and Girshick et al. pioneered tractable methods that infer a full-body pose reconstruction in real-time. Despite this technological breakthrough, the accuracy of human pose estimation from single depth images remains insufficient for some applications. Our work aims at building a simulation environment to create images databases suited for any camera position and improving the mainstream machine learning-based pose estimation algorithms. [less ▲]

Detailed reference viewed: 37 (13 ULg)
Full Text
See detailAharonov-Bohm oscillations of bosonic matter-wave beams in the presence of disorder and interaction
Chrétien, Renaud ULg; Dujardin, Julien; Petitjean, Cyril ULg et al

Poster (2016, May 18)

We study the one-dimensional (1D) transport properties of an ultracold gas of Bose-Einstein condensed atoms through Aharonov-Bohm (AB) rings. Our system consists of a Bose-Einstein condensate (BEC) that ... [more ▼]

We study the one-dimensional (1D) transport properties of an ultracold gas of Bose-Einstein condensed atoms through Aharonov-Bohm (AB) rings. Our system consists of a Bose-Einstein condensate (BEC) that is outcoupled from a magnetic trap into a 1D waveguide which is made of two semi-infinite leads that join a ring geometry exposed to a synthetic magnetic flux φ. We specifically investigate the effects both of a disorder potential and of a small atom-atom contact interaction strength on the AB oscillations. The main numerical tools that we use for this purpose are a mean-field Gross-Pitaevskii (GP) description and the truncated Wigner (tW) method. We find that a correlated disorder suppress the AB oscillations leaving thereby place to weaker amplitude, half period oscillations on transmission, namely the Aronov-Al’tshuler-Spivak (AAS) oscillations. The competition between disorder and interaction leads to a flip of the transmission at the AB flux φ = π. This flip could be a possible preliminary signature of an inversion of the coherent backscattering (CBS) peak. Our study paves the way to an analytical description of the inversion of that peak. [less ▲]

Detailed reference viewed: 15 (2 ULg)
Full Text
Peer Reviewed
See detailAnticoherence of spin states with point-group symmetries
Baguette, Dorian ULg; Damanet, François ULg; Giraud, Olivier et al

Poster (2016, May 18)

Detailed reference viewed: 21 (4 ULg)
Full Text
Peer Reviewed
See detailChaotic Bohmian trajectories for stationary states
Cesa, Alexandre ULg; Martin, John ULg; Struyve, Ward

Poster (2016, May 18)

We study the possibility of chaos for the Bohmian dynamics when the wave function is stationary. Examples of stationary wave functions are given for which there is chaos, as demonstrated by numerical ... [more ▼]

We study the possibility of chaos for the Bohmian dynamics when the wave function is stationary. Examples of stationary wave functions are given for which there is chaos, as demonstrated by numerical computations, for one particle moving in 3 spatial dimensions and for two and three entangled particles in 2 dimensions. What is important for the amount of chaos is the overall complexity of the wave function. Some simple measures that partly capture the complexity of the wave function are considered: the participation ratio and different measures of entanglement. We find that these measures often tend to correlate to the amount of chaos. However, the correlation is not perfect, because the measures do not depend on the intrinsic complexity of the states of a given basis. [less ▲]

Detailed reference viewed: 21 (4 ULg)
Full Text
Peer Reviewed
See detailSuper- and subradiance from indistinguishable atoms with quantized motion
Damanet, François ULg; Braun, Daniel; Martin, John ULg

Poster (2016, May 18)

Detailed reference viewed: 18 (2 ULg)
Full Text
See detailDevelopment of a hydrogen maser in the TE111 mode
Van Der Beken, Emeline ULg; Léonard, Daniel; Counet, Arnaud et al

Poster (2016, May 18)

We present the recent progress in the development of a hydrogen maser in the unusual TE111 mode. In contrast to standard hydrogen maser that exploits the TE011 mode, the TE111 mode allows one to design ... [more ▼]

We present the recent progress in the development of a hydrogen maser in the unusual TE111 mode. In contrast to standard hydrogen maser that exploits the TE011 mode, the TE111 mode allows one to design hydrogen masers with significant reduced dimensions which represents a huge benefit for space applications and in particular for the global positioning system. We present in details the different parts of our model : cavity with a thin Teflon sheet, magnetic shielding, temperature control of the maser... [less ▲]

Detailed reference viewed: 11 (1 ULg)
Full Text
See detailVortex Image Processing (VIP) package for high-contrast direct imaging
Gómez González, Carlos ULg; Absil, Olivier ULg; Wertz, Olivier ULg et al

Poster (2016, May 16)

VIP is a Python instrument-agnostic toolbox featuring a flexible framework for reproducible and robust data reduction. VIP currently supports three high-contrast imaging observational techniques: angular ... [more ▼]

VIP is a Python instrument-agnostic toolbox featuring a flexible framework for reproducible and robust data reduction. VIP currently supports three high-contrast imaging observational techniques: angular, reference-star and multi-spectral differential imaging. The code can be downloaded from our git repository on Github: http://github.com/vortex-exoplanet/VIP [less ▲]

Detailed reference viewed: 17 (2 ULg)
See detailCharacterization of FRD3, a zinc and iron homeostasis actor, in Arabidopsis
Scheepers, Maxime ULg; Charlier, Jean-Benoit; Spielmann, Julien ULg et al

Poster (2016, May 13)

Detailed reference viewed: 25 (5 ULg)
See detailTailoring γ-Al2O3 supports with specific silicon precursors
Claude, Vincent ULg; Vilaseca, Miriam; Heinrichs, Benoît ULg et al

Poster (2016, May 13)

Detailed reference viewed: 10 (4 ULg)
Full Text
See detailRestricted interests in autism with versus without speech onset delay : the importance of perceptually versus thematically organized interests
Chiodo, Liliane ULg; Majerus, Steve ULg; Eusèbe, Sandrine et al

Poster (2016, May 13)

Objectives : To explore whether autistic adults with vs without speech delay also differ in the perceptual vs thematic nature of their restricted interests.

Detailed reference viewed: 21 (5 ULg)
Full Text
See detailSpatial Analysis of the Landslide Risk in the Cameroon Volcanic Line (CVL)
Mukenga, Williams ULg; Havenith, Hans-Balder ULg; Medjo Eko, Robert et al

Poster (2016, May 12)

Landslides are recognized as important geomorphologic process due to the role they play in the development of hill slopes in mountainous regions, and to related socio-economic consequences. There are many ... [more ▼]

Landslides are recognized as important geomorphologic process due to the role they play in the development of hill slopes in mountainous regions, and to related socio-economic consequences. There are many causes of landslides and their distribution varies with the changing conditioning factors. Slope stability depends on a number of causative factors and the knowledge of these variables can help to predict the type of landslide expected in the future. In this study, past landslide activity and triggering factors will be used to assess mass movement hazards along the Cameroon Volcanic Line (CVL). Spatial aspects will be studied in terms of landslide susceptibility maps that are important for development planning and disaster management. The current synthesis of landslide susceptibility map at regional scale is based on a literature review to inventory passed mass movement impacts, on the detection of landslide features from Google Earth imagery, combined with spatial analysis using Geographical Information Systems (GIS) and remote sensing. One of the most critical stages in landslide susceptibility mapping is the selection of landslide pre-conditioning, conditioning and triggering factors and weighting of the selected causative factors in accordance to their influence on slope stability. Google earth helps for delineating past (but recent) and present landslide activity whereas GIS is suitable when deriving static factors (slope aspect and surface curvature) and time-dependent factors (annual precipitation and changing groundwater table level) that are needed to produce landslide susceptibility maps. Landslide susceptibility mapping is based on the assumption that future landslides will occur under similar circumstances as past and present mass movements. Different methods, including the weight of evidence methods, are used for landslide susceptibility mapping along the Cameroon Volcanic line, as the area is known to be highly susceptible to landslide occurrences. [less ▲]

Detailed reference viewed: 23 (2 ULg)
Full Text
See detailMolecular detection of single nucleotide polymorphisms on whole blood without DNA extraction
Detemmerman, L.; BOEMER, François ULg; SEGERS, Karin ULg et al

Poster (2016, May 12)

Detailed reference viewed: 9 (1 ULg)
Full Text
See detailAccurate measurement of radius evolution as a function of direction in 3D images
Plougonven, Erwan ULg; Hubert, Julien ULg; Collin, Frédéric ULg et al

Poster (2016, May 11)

Very often the reason for using of X-Ray tomography in a research project is to measure the evolution of some geometrical characteristic. The sought characteristic may be explained in simple words like ... [more ▼]

Very often the reason for using of X-Ray tomography in a research project is to measure the evolution of some geometrical characteristic. The sought characteristic may be explained in simple words like size, shape, or distance, but in practice measures based on these notions can have a complex implementation. We present a simple problem, measuring the evolution of radius in a cylindrical sample (a common shape for sample preparation for tomography) and how this value differs according the direction in which we look, when such evolution is known to be anisotropic. The solution is not unique, but we show that a naïve manual approach are not accurate enough, and how even a simple geometric notion such as radius needs a thorough definition in relation to its applicability to 3D image analysis. We extend the argument to how a good understanding of the notions and algorithms used in the quantification of geometrical characteristics can directly affect the pertinence and representativity of the results. [less ▲]

Detailed reference viewed: 21 (2 ULg)
Full Text
Peer Reviewed
See detailFrom Metabolomics to Identification of a new therapeutic approach for Age-Related Macular Degeneration (AMD)
Schoumacher, Matthieu ULg; De Tullio, Pascal ULg; LAMBERT, Vincent ULg et al

Poster (2016, May)

Age-related macular degeneration (AMD) is the leading cause of vision loss in the western world among people aged 50 or older. 90% of all vision loss due to AMD result from the exudative form, which is ... [more ▼]

Age-related macular degeneration (AMD) is the leading cause of vision loss in the western world among people aged 50 or older. 90% of all vision loss due to AMD result from the exudative form, which is characterized by choroidal neovascularization (CNV). Age-related changes that induce pathologic CNV are incompletely understood and critical issues remain to be addressed. Metabolomics is defined as the comprehensive study of endogenous metabolites changes in various biological systems. This newly emerging “omic” science provides a unique opportunity to correlate variation of the metabolome with pathological occurrence or progression and/or to identify metabolites that are implicated in the disease. We apply a 1H NMR metabolomics approach on sera collected from AMD patient and healthy volunteers and form a mice model of laser-induced CNV which mimics the effect of exudative AMD. After post-processing treatments, the different spectra were analyzed by statistical discriminant methodologies (PCA, ICA, PLS-DA, O-PLS-DA). These approaches allow the differentiation between control and AMD patients and between laser-induced mice and the control mice group. Moreover, the same discriminating spectral zones have been identified in human and mice model, leading to the emergence of different putative biomarkers. Among these markers, lactate emerges as a key metabolite in both settings. Mechanistically, lactate produced locally and by inflammatory cells, plays a critical role in the onset of the inflammatory and angiogenic phases. In mice model of laser-induced CNV, normalization of circulating lactate by dichloroacetate a pyruvate dehydrogenase kinase (PDK) inhibitor, decreases CNV development. Our data support the innovative concept of lactate as a parainflammation- and angio-metabolite associated to AMD and CNV progression. Moreover, control of blood lactate level via inhibition of PDK provides new options for the treatment of exudative AMD. This study demonstrates the ability of metabolomics for drug target discovery and opens new perspectives for AMD treatment and patient follow-up. [less ▲]

Detailed reference viewed: 11 (5 ULg)
Full Text
Peer Reviewed
See detailFrom Metabolomics Study of Age-Related Macular Degeneration (AMD) to the Development of New Pyruvate Dehydrogenase Kinase Inhibitors (PDK)
Arslan, Deniz ULg; Schoumacher, Matthieu ULg; Pirotte, Bernard ULg et al

Poster (2016, May)

Age-related macular degeneration (AMD) is a leading cause of blindness in the elderly population of industrialized countries. This blindness results from the deterioration of the macula, a small part of ... [more ▼]

Age-related macular degeneration (AMD) is a leading cause of blindness in the elderly population of industrialized countries. This blindness results from the deterioration of the macula, a small part of the retina specialized for the high-acuity vision. Exudative AMD, called “wet”, is characterized by the formation of new blood vessels growing under the retina according to a process named choroidal neovascularization (CNV). Currently, the aetiology and pathogenesis of AMD remain unclear. Nevertheless, a recent metabolomics study performed on the serum of “wet” AMD patients and on a CNV murine model, that mimics the effect of “wet” AMD, have demonstrated that lactate level is clearly involved in the severity of the pathology as well as the relationship between lactate, CNV and AMD. According to this result, we suggest a new therapeutic approach of AMD based on the normalization of blood lactate level. The modulation of the lactate plasma concentration by treatment of the animals with synthetic compounds and more specifically Pyruvate Dehydrogenase Kinase (PDK) inhibitors significantly decrease the CNV. PDK and its four isoforms (PDK1-4) regulate the activity of the pyruvate dehydrogenase complex (PDH), a mitochondrial enzyme that plays a major role in the metabolic pathway of glucose, by reversible phosphorylation. Starting from these results, development of new PDK inhibitors could open the way to innovative treatment opportunities in AMD disease. Different analogues of (R)-3,3,3-trifluoro-2-hydroxy-2-methylpropanamide (fig.1) have been already synthetized and pharmacological evaluation is currently in progress. According to the results obtained, various pharmacomodulations will be investigated [less ▲]

Detailed reference viewed: 17 (5 ULg)
See detailThe CCAMBIO project to characterize the biodiversity and distribution of microorganisms in microbial mats of Antarctic lakes
Durieu, Benoit ULg; Lara, Yannick ULg; Obbels, Dagmar et al

Poster (2016, April 29)

The BelSPO project CCAMBIO aims to study the biogeographical distribution of microorganisms in lacustrine microbial mats using a combination of techniques including microscopical observations (light and ... [more ▼]

The BelSPO project CCAMBIO aims to study the biogeographical distribution of microorganisms in lacustrine microbial mats using a combination of techniques including microscopical observations (light and electronic microscopy), strain isolation, and molecular diversity assessment using Next Generation Sequencing. The samples were collected in different Antarctic and sub-Antarctic biogeographical regions. A detailed microscopic study of the Antarctic diatom diversity allowed to revise a number of taxa and discover new ones. A multivariate analysis of diatoms showed that these regions hosted different diatom flora. Endemic diatom taxa were also observed, and a multigene molecular phylogeny of Pinnularia borealis showed a high genetic diversity. Pilot studies were conducted for the microeukaryotes and cyanobacteria to select NGS protocols and bioinformatic pipelines. Preliminary multivariate analysis of over 100 samples revealed that distinct biogeographic zones could be recognized in both the prokaryote and eukaryote data, which is in agreement with the classical subdivision of the Antarctic Realm into Maritime Antarctica, Continental Antarctica and the Sub-Antarctic Islands generally observed in plants and animals. Moreover, Sub-Antarctic assemblages harboured more complex foodwebs, with quite diverse metazoan groups. Lakes on the continent, however, were characterised by fewer metazoan groups and a greater importance of microbial herbivores and secondary consumers, including a relative high diversity of ciliates and tardigrades. Variation partitioning analysis revealed that spatial variables that approximated large-scale regional contrasts in historical (e.g. deglaciation history, geological origin) and climatic factors (e.g. mean annual air temperature) significantly explained the largest portion of the observed variation in community structure for eukaryotes, while in the prokaryote data environmental gradients related to conductivity were more important. In a first analysis of microbial mats from five Antarctic lakes and an aquatic biofilm from the Sub-Antarctic, the majority of the cyanobacterial OTUs retrieved were related to filamentous taxa such as Leptolyngbya and Phormidium, which are common genera in Antarctic lacustrine microbial mats. However, other phylotypes related to different taxa such as Geitlerinema, Pseudanabaena, Synechococcus, Chamaesiphon, Calothrix and Coleodesmium were also found. Results revealed a higher diversity than what had been reported using traditional methods based on microscopic observations and cultivation and also highlighted remarkable differences between the cyanobacterial communities of the studied lakes. In the next months, the molecular diversity data will be deposited into the “Microbial Antarctic Resource System (MARS)” presently developed into the webportal ‘biodiversity.aq’. The better knowledge of the diversity and distribution of microorganisms will contribute to a better assessment of their resilience and local/regional responses to global change. [less ▲]

Detailed reference viewed: 29 (2 ULg)
Full Text
See detailUse of stable isotope ratios to delineate coastal benthic food web structure in Adélie Land (East Antarctica)
Michel, Loïc ULg; Dubois, Philippe; Eleaume, Marc et al

Poster (2016, April 29)

Antarctica currently undergoes strong and contrasted impacts linked with climate change. While the West Antarctic Peninsula is one of the most rapidly warming regions in the world, resulting in sea ice ... [more ▼]

Antarctica currently undergoes strong and contrasted impacts linked with climate change. While the West Antarctic Peninsula is one of the most rapidly warming regions in the world, resulting in sea ice cover decrease, in some parts of East Antarctica sea ice cover tends to increase, possibly in relation with changes in atmospheric circulation. Changes in sea ice cover are likely to influence benthic food web structure through modifications of benthic-pelagic coupling, disruption of benthic production and/or modifications of benthic community structure (i.e. resource availability for benthic consumers). Here, we studied shallow (0-20 m) benthic food web structure on the coasts of Petrels Island (Adélie Land, East Antarctica) during an event of unusually high spatial and temporal (two successive austral summers without seasonal break-up) sea ice cover. Using stable isotope ratios of C, N and S, we examined importance of several organic matter sources (benthic macroalgae, benthic biofilm, sympagic algae, suspended particulate organic matter and penguin guano) for nutrition of over 20 taxa of benthic invertebrates (sponges, sea anemones, nemerteans, sessile and mobile polychaetes, gastropods, bivalves, sipunculids, pycnogonids, amphipods, sea stars, sea urchins and sea cucumbers) spanning most present functional guilds. Our results provide insights about how Antarctic benthic consumers, which have evolved in an extremely stable environment, might adapt their feeding habits in response to sudden changes in environmental conditions and trophic resource availability. [less ▲]

Detailed reference viewed: 52 (9 ULg)
See detailElucidating diversity of thin filamentous mat-forming Antarctic cyanobacteria
Lara, Yannick ULg; Durieu, Benoit ULg; Deblander, Victor ULg et al

Poster (2016, April 29)

Freshwater ecosystems range from glacial cryoecosystems, ice shelf meltwater ponds to perennially ice-covered lakes where conspicuous benthic microbial mat communities constitute most of the biomass. In ... [more ▼]

Freshwater ecosystems range from glacial cryoecosystems, ice shelf meltwater ponds to perennially ice-covered lakes where conspicuous benthic microbial mat communities constitute most of the biomass. In these mats, cyanobacteria form matrices that shelter other organisms, and carry out the primary production. Narrow filamentous cyanobacteria belonging to the genera Leptolyngbya and Phormidium are especially abundant in Antarctic microbial mats and are essential for the formation of matrix. However, the lack of morphological criteria and the small cell size of cyanobacteria belonging to these two genera make their identification problematic. Indeed, they are known as polyphyletic taxa according to botanical and bacteriological criteria. The characterization of strains is the first step for an assessment of the real diversity and for understanding their role in the environment. We designed a polyphasic approach that combines molecular analyses, environmental physiology experiments and microscopic observations. Briefly, we amplified and sequenced three loci (16S rRNA, ITS, and rpoC1) for 31 strains of Leptolyngbya and Phormidium. We performed whole genome sequencing for five strains. Cultures at different stage were observed by light and epifluorescence microscopy. Finally, selected strains were grown in nitrogen-limited. The Leptolyngbya and Phormidium strains were distributed into four lineages. Phylogenetic trees supported the distribution of P. priestleyi strains into at least two potentially new lineages, and L. antarctica strains were separated into one endemic and one cosmopolitan lineage. This was supported by the microscopic observations of 1-year old cultures. Genome analyses revealed the presence of sequences related to the production of secondary metabolites in strains from two of the studied lineages. Secondary metabolites are often known for their antimicrobial activities. Such properties would partly explain how cyanobacterial mats survive to predation and degradation by other bacteria. This work provides the first building block to the understanding of survival strategies developed by mat-forming cyanobacteria and how they succeeded as the most abundant phototrophs on the Antarctic continent. This work was realized in the frame of the BelSPo project CCAMBIO. [less ▲]

Detailed reference viewed: 51 (12 ULg)
Full Text
Peer Reviewed
See detailModelling of long-term deep renovation strategies for the Belgian building stock
Ruellan, Guirec ULg

Poster (2016, April 28)

To achieve the EU energy targets for 2050, the construction sector has to perform major transformations. In Belgium, the majority of building stock is particularly old and energy inefficient. The high ... [more ▼]

To achieve the EU energy targets for 2050, the construction sector has to perform major transformations. In Belgium, the majority of building stock is particularly old and energy inefficient. The high performance of new constructions represented in the nearly zero energy buildings target is not sufficient to ensure the efficiency of the overall building sector. Therefore, it is crucial to put in place a progressive renovation policy. Despite the different renovation strategies and projects that took place in the recent year in Belgium, the overall renovation rate remains almost stable for the last ten years. This study focuses on the renovation market in Belgium and analyzes the factors that influence the evolution of the renovation rate. The objective is the identification and development of effective strategies bypass that leads to increased renovation rates in Belgium. The research methodology is based on an iterative process, based on a systematic literature review of Flemish and Walloon projects, publications and policy. These first work package will allow to identify factors influencing the renovation rate and in other hand to build a model of the existing building stock. Impacts of the influencing factors on the building stock are simulated in the fourth work package in order to propose an action plan in the last part. Three mains outcomes are expected: A model of the existing building stock in Belgium and its retrofit potential, a simulation of the effects of different strategies used to increase the renovation rate in Belgium and a theoretical action plan on strategies to increase the rate of renovation in Belgium. These results are necessary to inform and support the decision making of policy makers, municipalities and operational planning authorities across Belgium. [less ▲]

Detailed reference viewed: 23 (4 ULg)
Full Text
Peer Reviewed
See detailDenCity: Zero Energy Lightweight Construction Households for Urban Densification
Mahmoud, Mohamed ULg; Attia, Shady ULg

Poster (2016, April 27)

Belgium, like many European Countries, has a serious challenge in the housing sector. The Federal planning bureau estimates the increase of the population by one million inhabitants by 2030, which ... [more ▼]

Belgium, like many European Countries, has a serious challenge in the housing sector. The Federal planning bureau estimates the increase of the population by one million inhabitants by 2030, which represent 600,000 additional family requiring accesses to new housing facilities. There is a significant housing shortage for individual, single parent families, seniors and students. Population ageing (mainly due to increase life expectancy) combined with a constant grow rate of individuals living in collective households, leads to a substantial increase of demand of collective households. Furthermore, the stringent European performance environmental regulations for the building sector require that by 2020, all new construction are zero or nearly zero energy, (equivalent to 15 kWh/m2/year), with 60% efficient on-site coverage by renewable energy. The shortage of vacant land and the increasing energy performance requirements is pushing the idea of urban densification and zero energy construction households. [less ▲]

Detailed reference viewed: 25 (15 ULg)
Full Text
Peer Reviewed
See detailIsolation and characterization of mutants deficient in four steps of the phylloquinone biosynthesis pathway in Chlamydomonas reinhardtii.
Emonds-Alt, Barbara ULg; Remacle, Claire ULg; Cardol, Pierre ULg

Poster (2016, April 26)

In photosystem I (PSI), phylloquinone participates to electron transfer as secondary electron acceptor (A1). The phylloquinone biosynthesis pathway, previously characterized by reverse genetic in ... [more ▼]

In photosystem I (PSI), phylloquinone participates to electron transfer as secondary electron acceptor (A1). The phylloquinone biosynthesis pathway, previously characterized by reverse genetic in Synechocystis sp. PCC 6803, involves 8 enzymatic steps from chorismate [1]. In the green alga Chlamydomonas reinhardtii, characterization of phylloquinone biosynthesis was still partial and only one mutant deficient for MEND was characterized [2]. In the present work, we found MENA-H homologs in C. reinhardtii genomic database. In particular, MENF, MEND, MENC, and MENH catalytic domains are present in a single ORF (named PHYLLO by similarity to gene organisation in Arabidopsis). We then took advantage of the fact that a double reduction of plastoquinone (PQ) in PQH2 occurs in anoxia into the A1 site in the mend mutant, interrupting photosynthetic electron transfer [3], to isolate new phylloquinone-deficient strains. UPLC-MS analysis confirmed the absence of phylloquinone in four news mutants impaired in MENA, MENB, MENC (PHYLLO) and MENE. Despite this loss, men mutants are still able to grow in low light but are high light-sensitive. In low light, the level of active PSII in men mutants is identical to that of the wild-type, but the level of active PSI is reduced by 30-40% as assayed by spectroscopic measurements. This decrease is more pronounced when cells are exposed to high light intensities during 4 hours. The level of active PSI is ~ 10% of wild-type cells and the electron photosynthetic transfer is reduced accordingly. Reorganization of the photosynthetic apparatus following lack of phylloquinone in men mutants is discussed. [less ▲]

Detailed reference viewed: 10 (4 ULg)
See detailValidity of algometry and video assessment to diagnose pain in sheep with knee synovitis
Niessen, J; Nisolle, JF; Hontoir, F et al

Poster (2016, April 23)

Reasons to perform study. To assess lameness in animals, semi-objective scales are used. Video is sometimes used to enable blinding of the clinician. In addition, the assessment of pain is particularly ... [more ▼]

Reasons to perform study. To assess lameness in animals, semi-objective scales are used. Video is sometimes used to enable blinding of the clinician. In addition, the assessment of pain is particularly difficult in animals since they cannot report their feelings. The interpretation of the reactions of the animals can be different between observers. A method to quantify pain is the measure of mechanical nociceptive thresholds (MNT), a method called algometry. Since synovitis is often linked to swelling of periarticular tissues and to synovial fluid effusion, palpation of the joint is also a useful test. The objectives of the current study were to assess in sheep whether (1) video assessment of lameness is in agreement with real observation; (2) algometry of the knee is correlated with lameness evaluation; (3) algometry is correlated with identification of swelling by palpation. Material and methods. The population of sheep enrolled in a controlled trial at the Ovine Research Center of UNamur was used for the current study. Results. There was a moderate inter-rater agreement (value of kappa was 0,41) between the experimenter who evaluated the ewes on site and the one who watched the videos. No significant correlation was identified between lameness scores and algometry. A negative correlation (algometry reactive threshold is lower when palpation score is higher) was identified between palpation scores and MNT (P<0.05). Discussion. Video assessment can be used in research to assess lameness. The experience of the observer must be taken into account. Algometry is not entirely valid since an adaptation or learning process seems to develop in sheep. [less ▲]

Detailed reference viewed: 16 (2 ULg)
Full Text
See detailEffect of Ribes nigrum leaf extracts on endothelium-dependent vasorelaxation
Tabart, Jessica; Shini-Kerth, Valérie; PINCEMAIL, Joël ULg et al

Poster (2016, April 22)

Detailed reference viewed: 14 (4 ULg)
See detailUsing a dynamic vegetation model for future projections of crop yields : application to Belgium in the framework of the VOTES and MASC projects
Jacquemin, Ingrid ULg; Henrot, Alexandra-Jane ULg; Fontaine, Corentin M. et al

Poster (2016, April 22)

Dynamic vegetation models (DVM) were initially designed to describe the dynamics of natural ecosystems as a function of climate and soil, to study the role of the vegetation in the carbon cycle. These ... [more ▼]

Dynamic vegetation models (DVM) were initially designed to describe the dynamics of natural ecosystems as a function of climate and soil, to study the role of the vegetation in the carbon cycle. These models are now directly coupled with climate models in order to evaluate feedbacks between vegetation and climate. But DVM characteristics allow numerous other applications, leading to amelioration of some of their modules (e.g., evaluating sensitivity of the hydrological module to land surface changes) and developments (e.g., coupling with other models like agent-based models), to be used in ecosystem management and land use planning studies. It is in this dynamic context about DVMs that we have adapted the CARAIB (CARbon Assimilation In the Biosphere) model. One of the main improvements is the implementation of a crop module, allowing the assessment of climate change impacts on crop yields. We try to validate this module at different scales: - from the plot level, with the use of eddy-covariance data from agricultural sites in the FLUXNET network, such as Lonzée (Belgium) or other Western European sites (Grignon, Dijkgraaf,. . . ), - to the country level, for which we compare the crop yield calculated by CARAIB to the crop yield statistics for Belgium and for different agricultural regions of the country. Another challenge for the CARAIB DVM was to deal with the landscape dynamics, which is not directly possible due to the lack of consideration of anthropogenic factors in the system. In the framework of the VOTES and the MASC projects, CARAIB is coupled with an agent-based model (ABM), representing the societal component of the system. This coupled module allows the use of climate and socio-economic scenarios, particularly interesting for studies which aim at ensuring a sustainable approach. This module has particularly been exploited in the VOTES project, where the objective was to provide a social, biophysical and economic assessment of the ecosystem services in four municipalities under urban pressure in the center of Belgium. The biophysical valuation was carried out with the coupled module, allowing a quantitative evaluation of key ecosystem services as a function of three climatic and socio-economic scenarios. [less ▲]

Detailed reference viewed: 22 (7 ULg)
Full Text
See detailHigh anthocyanins content of commercial blackcurrant juices induced endothelium-dependent relaxation in isolated porcine coronary arteries
Kevers, Claire ULg; Shini-Kerth, Valérie; Tabart, Jessica et al

Poster (2016, April 22)

Detailed reference viewed: 13 (1 ULg)
Full Text
Peer Reviewed
See detailSupporting integrated and systemic management of windthrow crises by public decision-makers
Riguelle, Simon ULg; Hebert, Jacques ULg; Lejeune, Philippe ULg et al

Poster (2016, April 21)

This poster presents the development of an integrated framework for systemic management of storm damage risk in Wallonia (Belgium) and how it can be implemented throughout the risk management cycle with ... [more ▼]

This poster presents the development of an integrated framework for systemic management of storm damage risk in Wallonia (Belgium) and how it can be implemented throughout the risk management cycle with user-friendly tools and suitable methodologies. [less ▲]

Detailed reference viewed: 24 (5 ULg)
Peer Reviewed
See detailHeart failure assessment with a multiscale model
Negroni, Jorge; Cabrera-Fischer, Edmundo; Kosta, Sarah ULg et al

Poster (2016, April 21)

Many cardiac diseases lead to heart failure (HF) causing increasing morbidity and mortality worldwide. Several alterations at the myocyte level have been identified, but their specific influence on ... [more ▼]

Many cardiac diseases lead to heart failure (HF) causing increasing morbidity and mortality worldwide. Several alterations at the myocyte level have been identified, but their specific influence on contractile and hemodynamic impairment is not yet clear. Mathematical modeling is a tool to address this issue enabling the analysis of individual myocyte changes on the overall circulatory response. Some myocyte models have been able to reproduce the impact of HF on experimentally detected myocyte components (1), but their integration into a ventricular model forming part of a multiscale circulatory approach has not been fully undertaken. Thus, the aim of this study is to compare the experimental hemodynamic and regional contractile response to acute HF versus a multiscale model based on a human myocyte representation. The experimentally-validated multiscale model shows adequate coupling between myocyte-derived left ventricular chamber and circulatory properties , and would be useful to predict the contractile and hemodynamic response to HF changes in myocyte variables. [less ▲]

Detailed reference viewed: 19 (1 ULg)
See detailHigh-resolution climate and land surface interactions modeling over Belgium: current state and decennial scale projections
Jacquemin, Ingrid ULg; Henrot, Alexandra-Jane ULg; Beckers, Veronique et al

Poster (2016, April 21)

The interactions between land surface and climate are complex. Climate changes can affect ecosystem structure and functions, by altering photosynthesis and productivity or inducing thermal and hydric ... [more ▼]

The interactions between land surface and climate are complex. Climate changes can affect ecosystem structure and functions, by altering photosynthesis and productivity or inducing thermal and hydric stresses on plant species. These changes then impact socio-economic systems, through e.g., lower farming or forestry incomes. Ultimately, it can lead to permanent changes in land use structure, especially when associated with other non-climatic factors, such as urbanization pressure. These interactions and changes have feedbacks on the climate systems, in terms of changing: (1) surface properties (albedo, roughness, evapotranspiration, etc.) and (2) greenhouse gas emissions (mainly CO2, CH4, N2O). In the framework of the MASC project (« Modelling and Assessing Surface Change impacts on Belgian and Western European climate »), we aim at improving regional climate model projections at the decennial scale over Belgium and Western Europe by combining high-resolution models of climate, land surface dynamics and socio-economic processes. The land surface dynamics (LSD) module is composed of a dynamic vegetation model (CARAIB) calculating the productivity and growth of natural and managed vegetation, and an agent-based model (CRAFTY), determining the shifts in land use and land cover. This up-scaled LSD module is made consistent with the surface scheme of the regional climate model (RCM: ALARO) to allow simulations of the RCM with a fully dynamic land surface for the recent past and the period 2000-2030. In this contribution, we analyze the results of the first simulations performed with the CARAIB dynamic vegetation model over Belgium at a resolution of 1km. This analysis is performed at the species level, using a set of 17 species for natural vegetation (trees and grasses) and 10 crops, especially designed to represent the Belgian vegetation. The CARAIB model is forced with surface atmospheric variables derived from the monthly global CRU climatology or ALARO outputs (from a 4 km resolution simulation) for the recent past and the decennial projections. Evidently, these simulations lead to a first analysis of the impact of climate change on carbon stocks (e.g., biomass, soil carbon) and fluxes (e.g., gross and net primary productivities (GPP and NPP) and net ecosystem production (NEP)). The surface scheme is based on two land use/land cover databases, ECOPLAN for the Flemish region and, for the Walloon region, the COS-Wallonia database and the Belgian agricultural statistics for agricultural land. Land use and land cover are fixed through time (reference year: 2007) in these simulations, but a first attempt of coupling between CARAIB and CRAFTY will be made to establish dynamic land use change scenarios for the next decades. A simulation with variable land use would allow an analysis of land use change impacts not only on crop yields and the land carbon budget, but also on climate relevant parameters, such as surface albedo, roughness length and evapotranspiration towards a coupling with the RCM. [less ▲]

Detailed reference viewed: 20 (6 ULg)
Full Text
Peer Reviewed
See detailTime lapse imaging of water content with geoelectrical methods: on the interest of working with absolute water content data
Dumont, Gaël ULg; Pilawski, Tamara ULg; Robert, Tanguy et al

Poster (2016, April 21)

The electrical resistivity tomography is a suitable method to estimate the water content of a waste material and detect changes in water content. Various ERT profiles, both static data and time-lapse ... [more ▼]

The electrical resistivity tomography is a suitable method to estimate the water content of a waste material and detect changes in water content. Various ERT profiles, both static data and time-lapse, where acquired on a landfill during the Minerve project. In the literature, the relative change of resistivity ( Delta rho/rho ) is generally computed. For saline or heat tracer tests in the saturated zone, the Delta rho/rho can be easily translated into pore water conductivity or underground temperature changes (provided that the initial salinity or temperature condition is homogeneous over the ERT panel extension). For water content changes in the vadose zone resulting of an infiltration event or injection experiment, many authors also work with the Delta rho/rho or relative changes of water content Delta theta /theta (linked to the change of resistivity through one single parameter: the Archie’s law exponent “m”). This parameter is not influenced by the underground temperature and pore fluid conductivity ( rho_w) condition but is influenced by the initial water content distribution. Therefore, you never know if the loss of / signal is representative of the limit of the infiltration front or more humid initial condition. Another approach for the understanding of the infiltration process is the assessment of the absolute change of water content ( Delta theta ). This requires the direct computation of the water content of the waste from the resistivity data. For that purpose, we used petrophysical laws calibrated with laboratory experiments and our knowledge of the in situ temperature and pore fluid conductivity parameters. Then, we investigated water content changes in the waste material after a rainfall event ( Delta theta = Delta theta /theta * theta ). This new observation is really representatives of the quantity of water infiltrated in the waste material. However, the uncertainty in the pore fluid conductivity value may influence the computed water changes ( Delta theta =k*m*(rho_w)^1/2 ; where “m” is the Archie’s law exponent). Using these two complementary approaches, we analyzed the effect a major rainfall (20-30 mm in 2 hours) that occurred on the test site, characterized by a vegetalized and relatively dry zone and a devegatelized and humid zone. We intended to prove that most of the information contained in the Delta theta /theta distribution is the initial water content distribution in the ground.Water addition in dry zones resulting in large relative changes. The computation of the Delta theta is necessary to demonstrate preferential infiltration through the capping in a restricted zone of the vegetalized area. [less ▲]

Detailed reference viewed: 22 (6 ULg)
Full Text
Peer Reviewed
See detailAssessment of a design to monitor the influence of crop residue management on the dynamics of soil water content with ERT
Chelin, Marie ULg; Hiel, Marie-Pierre ULg; Hermans, Thomas ULg et al

Poster (2016, April 21)

Choices related to crop residue management affect the soil structure. As a consequence, they may determinethe spatio-temporal dynamics of water content and eventually the crop yields. In order to better ... [more ▼]

Choices related to crop residue management affect the soil structure. As a consequence, they may determinethe spatio-temporal dynamics of water content and eventually the crop yields. In order to better understand the influence of these strategies on hydraulic processes occurring at the plot scale, we opted for the use electrical resistivity tomography (ERT). This approach presents the advantage to limit soil disturbance but is still faced to important challenges when applied in an agricultural field context. Especially changing soil-electrode contact has to be considered, as it can lead to bad quality data, especially for setups with small electrodes and small inter-electrode distance. The objective of this study was to test the efficiency of a high-resolution 3-D field measurement design to properly assess the dynamics of soil water content. ERT measurements were conducted in a Cutanic Siltic Luvisol in Gembloux, Belgium, on two plots of 2m^2 ploughed in Oct 2014 at a depth of 25 cm and sown with maize in April 2015. The plants were removed on one of the plots in order to obtain a bare soil reference. A grid of 98 surface stainless steel electrodes was layed-out on each plot and four sticks supporting each eight stainless steel electrodes were vertically inserted into the soil up to 1.20 m to get more detailed information in depth. The experiments were performed between Jul and Oct 2015, in order to get measurements both in dry and wet periods. For surface and borehole monitoring, a dipole-dipole array configuration including in-line and cross-line measurements was adopted. Normal and reciprocal measurements were performed systematically to assess the data quality: only the datasets with a mean reciprocal error lower than 3% were considered for the data inversion. This contribution will show the first inverted results showing the complexity of experimental design and data analysis for high-resolution, timelapse ERT in field conditions. Based on these results, we will draw conclusions about a minimal data set to be obtained in our upcoming field experiments. [less ▲]

Detailed reference viewed: 32 (4 ULg)
Full Text
See detailThe last millenia sedimentary record of Lago Esponja from Northern Chilean Patagonia
Fagel, Nathalie ULg; Alvarez, Denisse; Araneda, Alberto et al

Poster (2016, April 20)

We evaluate the climate and environmental variability of Northern Chilean Patagonia during the Last Millennia, using a multi-proxy analysis of a sediment core from Lago Esponja (45°09’S, 72°08’W). The ... [more ▼]

We evaluate the climate and environmental variability of Northern Chilean Patagonia during the Last Millennia, using a multi-proxy analysis of a sediment core from Lago Esponja (45°09’S, 72°08’W). The lake is located in the region of Aysen del General Carlos Ibanez del Campo, in NW Patagonia. The study focuses on a multiproxy analysis of sedimentary records. The longest core (150 cm long) was collected in 2014 at 40 m depth. The sediment, which is composed of light brown organic-rich clayey silt, was analyzed for sedimentology (grain size, magnetic susceptibility organic matter and biogenic silica content), mineralogy (X-ray diffraction) and geochemistry (elemental and isotopic analyses of C and N, XRF core-scaner at 1 mm resolution). The radiocarbon ages, measured on 3 macro-remains, demonstrate that the core covers the last 6.700 years. The sedimentation rate ranges between 0.1 mm/yr in the lower section (100-150 cm) and 0.4 mm/yr in the upper meter. Visual descriptions and Scopix radiographies show that the sediment record is finely laminated except a massive decimetric coarser and darker layer corresponding to a tephra (estimated age 700AD±50). Magnetic susceptibility (confirmed by scopix radiographies) highlights the presence of 8 additional millimetric tephra layers. The biogenic silica content of the sediment is low (mean 5%). Diatom assemblage is dominated by benthic and acidophilous species, with high saprobic values. None marked changes were observed regarding the dynamic of the lake. The high organic matter content (mean 15%) and its high C/N ratio (12.7) throughout the core indicate inputs of allochtonous and terrestrial organic matter. Such parameters present high sediment variability also marked by changes in the chemical composition. The laminations reflect changes in the allochtonous sedimentary inputs, with high terrestrial inputs during wetter conditions in relation with the Westerlies. The sedimentary records of Lago Esponja will be compared with Eastern lacustrine record from the same latitude in order to confirm the climate-driven record. [less ▲]

Detailed reference viewed: 12 (4 ULg)
Full Text
See detailData-Interpolating Variational Analysis (DIVA) software: recent development and application
Watelet, Sylvain ULg; Back, Örjan; Barth, Alexander ULg et al

Poster (2016, April 20)

Detailed reference viewed: 8 (1 ULg)
Full Text
See detailImpact of tillage on CO2 and N2O efflux in an agricultural crop
Lognoul, Margaux ULg; Theodorakopoulos, Nicolas ULg; Hiel, Marie-Pierre ULg et al

Poster (2016, April 20)

CO2 and N2O fluxes exchanged by a maize crop were measured from June to Octboer 2015 using a homemade automated system of dynamic closed chambers. We studied the impact of tillage (reduced and ... [more ▼]

CO2 and N2O fluxes exchanged by a maize crop were measured from June to Octboer 2015 using a homemade automated system of dynamic closed chambers. We studied the impact of tillage (reduced and conventional) on greenhouse gas emissions and nitrous oxide flux dynamics. [less ▲]

Detailed reference viewed: 29 (10 ULg)
Full Text
Peer Reviewed
See detailHeat tracer test in an alluvial aquifer: field experiment and inverse modelling
Klepikova, Maria; Wildemeersch, Samuel; Jamin, Pierre ULg et al

Poster (2016, April 20)

Using heat as an active tracer for aquifer characterization is a topic of increasing interest. In this study, we investigate the potential of using heat tracer tests for characterization of a shallow ... [more ▼]

Using heat as an active tracer for aquifer characterization is a topic of increasing interest. In this study, we investigate the potential of using heat tracer tests for characterization of a shallow alluvial aquifer. A thermal tracer test was conducted in the alluvial aquifer of the Meuse River, Belgium. The tracing experiment consisted in simultaneously injecting heated water and a dye tracer in a piezometer and monitoring the evolution of groundwater temperature and tracer concentration in the recovery well and in monitoring wells. To get insights in the 3D characteristics of the heat transport mechanisms, temperature data from a large number of observation wells distributed throughout the field site (space-filling arrangement) were used. Temperature breakthrough curves in observation wells are contrasted with what would be expected in an ideal layered aquifer. They reveal strongly unequal lateral and vertical components of the transport mechanisms. The observed complex behavior of the heat plume was explained by the groundwater flow gradient on the site and heterogeneity of hydraulic conductivity field. Moreover, due to high injection temperatures during the field experiment a temperature-induced fluid density effect on heat transport occurred. By using a flow and heat transport numerical model with variable density coupled with the pilot point inverse approach, main preferential flow paths were delineated. [less ▲]

Detailed reference viewed: 32 (9 ULg)
Full Text
See detailMines as lower reservoir of an UPSH (Underground Pumped Storage Hydroelectricity): groundwater impacts and feasibility
Bodeux, Sarah ULg; Pujades, Estanislao ULg; Orban, Philippe ULg et al

Poster (2016, April 20)

The energy framework is currently characterized by an expanding use of renewable sources. However, their inter- mittence could not afford a stable production according to the energy demand. Pumped Storage ... [more ▼]

The energy framework is currently characterized by an expanding use of renewable sources. However, their inter- mittence could not afford a stable production according to the energy demand. Pumped Storage Hydroelectricity (PSH) is an efficient possibility to store and release electricity according to the demand needs. Because of the topographic and environmental constraints of classical PSH, new potential suitable sites are rare in countries whose topography is weak or with a high population density. Nevertheless, an innovative alternative is to construct Underground Pumped Storage Hydroelectricity (UPSH) plants by using old underground mine works as lower reservoir. In that configuration, large amount of pumped or injected water in the underground cavities would impact the groundwater system. A representative UPSH facility is used to numerically determine the interactions with surrounding aquifers Different scenarios with varying parameters (hydrogeological and lower reservoir char- acteristics, boundaries conditions and pumping/injection time-sequence) are computed. Analysis of the computed piezometric heads around the reservoir allows assessing the magnitude of aquifer response and the required time to achieve a mean pseudo-steady state under cyclic solicitations. The efficiency of the plant is also evaluated taking the leakage into the cavity into account. Combining these two outcomes, some criterions are identified to assess the feasibility of this type of projects within potential old mine sites from a hydrogeological point of view. [less ▲]

Detailed reference viewed: 18 (4 ULg)
See detailDrought-related vulnerability and risk assessment of groundwater in Belgium: estimation of the groundwater recharge and crop yield vulnerability with the B-CGMS
Jacquemin, Ingrid ULg; Verbeiren, Boud; Vanderhaegen, Sven et al

Poster (2016, April 19)

Due to common belief that regions under temperate climate are not affected by (meteorological and groundwater) drought, these events and their impacts remain poorly studied: in the GroWaDRISK, we propose ... [more ▼]

Due to common belief that regions under temperate climate are not affected by (meteorological and groundwater) drought, these events and their impacts remain poorly studied: in the GroWaDRISK, we propose to take stock of this question. We aim at providing a better understanding of the influencing factors (land use and land cover changes, water demand and climate) and the drought-related impacts on the environment, water supply and agriculture. The study area is located in the North-East of Belgium, corresponding approximatively to the Dijle and Demer catchments. To establish an overview of the groundwater situation, we assess the system input: the recharge. To achieve this goal, two models, B-CGMS and WetSpass are used to evaluate the recharge, respectively, over agricultural land and over the remaining areas, as a function of climate and for various land uses and land covers. B-CGMS, which is an adapted version for Belgium of the European Crop Growth Monitoring System, is used for assessing water recharge at a daily timestep and under different agricultural lands: arable land (winter wheat, maize...), orchards, horticulture and floriculture and for grassland. B-CGMS is designed to foresee crop yield and obviously it studies the impact of drought on crop yield and raises issues for the potential need of irrigation. For both yields and water requirements, the model proposes a potential mode, driven by temperature and solar radiation, and a water-limited mode for which water availability can limit crop growth. By this way, we can identify where and when water consumption and yield are not optimal, in addition to the Crop Water Stress Index. This index is calculated for a given crop, as the number of days affected by water stress during the growth sensitive period. Both recharge and crop yield are assessed for the current situation (1980 – 2012), taking into account the changing land use/land cover, in terms of areas and localization of the agricultural land and where the proportion of the different crops had considerably evolved through time (e.g., increase of grain maize and potatoes while winter cereals decrease). The preliminary results of the recharge lead to an average value in the area showing a significant negative trend, in both simulations with fixed (base = 1980) and changing land cover. In the same time, we could observe an increasing number of water stress periods, especially for maize, one of the main crops in the area. Finally, a preliminary test will be presented for the horizon 2040, for which we use meteorological time series (for high and low hydrologic impacts) given by the CCI-HYDR Perturbation Tool (Ntegeka V. and Willems P., 2009). This preliminary test aims to (1) evaluate the amplitude of the potential recharge deficit and, (2) especially, to define vulnerability zones, affected by frequent water stress, in connection with irrigation needs which could possibly increase the groundwater extraction. [less ▲]

Detailed reference viewed: 17 (3 ULg)
Full Text
See detailReactive gases in the chemistry climate model ECHAM6-HAMMOZ
Schultz, Martin; Franco, Bruno ULg; Kaffashzadeh, Najmeh et al

Poster (2016, April 18)

The recently developed global chemistry climate model ECHAM6-HAMMOZ contains comprehensive and detailed schemes for tropospheric aerosol (HAM) and reactive gases chemistry (MOZ). The Jülich Atmospheric ... [more ▼]

The recently developed global chemistry climate model ECHAM6-HAMMOZ contains comprehensive and detailed schemes for tropospheric aerosol (HAM) and reactive gases chemistry (MOZ). The Jülich Atmospheric (chemical) Mechanism (JAM002) consists of more than 300 species and 650 reactions, including relatively detailed degradation pathways for various volatile organic compounds in the troposphere and stratosphere. State-of-the-art parameterisations for chemical and physical processes are included. Here we present evaluation results from a multi-year simulation of the present-day atmospheric composition. [less ▲]

Detailed reference viewed: 14 (2 ULg)
Full Text
See detailCanopy proximity estimation and impact on long term turbulent fluxes above a heterogeneous forest
Hurdebise, Quentin ULg; Vincke, Caroline; De Ligne, Anne ULg et al

Poster (2016, April 18)

With the development of eddy covariance networks like Fluxnet, ICOS or NEON, long-term data series of carbon dioxide, water vapor and other gas exchanges between terrestrial ecosystems and atmosphere will ... [more ▼]

With the development of eddy covariance networks like Fluxnet, ICOS or NEON, long-term data series of carbon dioxide, water vapor and other gas exchanges between terrestrial ecosystems and atmosphere will become more and more numerous. However, long-term analyses of such exchanges require a good understanding of measurement conditions during the investigated period. Independently of climate drivers, measurements may indeed be influenced by measurement conditions themselves subjected to long-term variability due to vegetation growth or set-up changes. The present research refers to the Vielsalm Terrestrial Observatory (VTO) where fluxes of momentum, carbon dioxide, latent and sensible heat have been continuously measured by eddy covariance during twenty years. VTO is an ICOS site installed in a mixed forest (beech, silver fir, Douglas fir, Norway spruce) in the Belgian Ardennes. A multidisciplinary approach was developed in order to investigate the spatial and temporal evolution of several site characteristics: - displacement height (d) and relative measurement height (z-d) were determined using a spectral approach that compared observed and theoretical cospectra; - turbulence statistics were analyzed in the context of Monin-Obukhov similarity theory; - tree height during the measurement period was obtained by combining tree height inventories, a LIDAR survey and tree growth models; - measurement footprint was determined by using a footprint model. A good agreement was found between the three first approaches. Results show notably that z-d was subjected to both temporal and spatial evolution. Temporal evolution resulted from continuous tree growth as well as from a tower raise, achieved in 2009. Spatial evolution, due to canopy heterogeneity, was also observed. The impacts of these changes on measurements are investigated. In particular, it was shown that they affect measurement footprint, flux spectral corrections and flux quality. All these effects must be taken into consideration in order to disentangle long-term flux evolutions due to climate or phenology from changes resulting from measurement set-up changes. [less ▲]

Detailed reference viewed: 21 (2 ULg)
Full Text
See detailSelection of wavelengths for the quantification of nitrogen concentration in winter wheat by multispectral vision
Marlier, Guillaume ULg; Leemans, Vincent ULg; Destain, Marie-France ULg et al

Poster (2016, April 18)

Hand-held sensors (SPAD meter, N-Tester, …) are used for detecting the leaves nitrogen concentration (Nc) on basis of an optical detection of the chlorophyll concentration. These devices are active ... [more ▼]

Hand-held sensors (SPAD meter, N-Tester, …) are used for detecting the leaves nitrogen concentration (Nc) on basis of an optical detection of the chlorophyll concentration. These devices are active sensors: an internal radiation source emits light and transmission through a leaf is measured in the red (650 nm) and in the near-infrared (920 nm) spectral regions. These devices present several drawbacks. The nitrogen concentration is gained by an indirect way through the chlorophyll concentration and the leaves have to be fixed in a defined position for the measurements. These drawbacks could be overcome by an imaging device that measures the canopy reflectance. Hence, the objective of the paper is to analyse the potential of multispectral imaging for detecting nitrogen concentration. The tests were carried out on parcels submitted to nitrogen inputs varying from 0 to 180 kg N.ha-1. Reference Nc measurements were obtained by the Kjeldahl method and a Hydro N-Tester (Yara). The developed imaging system comprised a CMos camera and a set of 22 interference filters ranging from 450 to 950 nm mounted on a wheel steered by a stepper motor. The image acquisition and the motor rotation were controlled by a program written in C++. The crop was imaged vertically at one meter height. The raw images presented 1280*1024 pixels covering an area approximately 0.5*0.4 m and were recorded with a 12 bits luminance resolution. To deal with the natural irradiance variability of the scene, a white reference was used and the integration time was automatically adjusted for each image. The image treatment included the segmentation of Photosynthetically Active Leaves (PAL) by using Bayes theorem and the computation of the mean PAL reflectance after correction of background and illumination fluctuations. Nc was estimated on basis of the 22 filters by Partial Least Square (PLS) method and by four filters selected by Best Subset Selection (BSS). In comparison with the Kjeldahl method, the estimation of Nc by the Hydro N-Tester, the PLS and the BSS (filters 600-80, 950-100, 650-40 and 450-80 nm) gave determination coefficient and standard error respectively equal to of 0.53, 0.29 %; 0.67, 0.21%; 0.56 and 0.25%. This indicated that the full multi-spectral approach gave significantly better Nc estimation than a portable device and suggested that a camera equipped with four filters would give similar results. [less ▲]

Detailed reference viewed: 12 (2 ULg)
See detailChemical and mineralogical proxies of erosion episodes in the dried lake sediments (Amik Lake, Southern Turkey): paleoenvironmental implications
El Ouahabi, Meriam ULg; Hubert, Aurelia ULg; Lebeau, Héléne et al

Poster (2016, April 17)

The Amik Basin in the Eastern Mediterranean region has been continuously occupied since 6000-7000 BC. The landscape has sustained with highly variable anthropic pressure culminating during the Late Roman ... [more ▼]

The Amik Basin in the Eastern Mediterranean region has been continuously occupied since 6000-7000 BC. The landscape has sustained with highly variable anthropic pressure culminating during the Late Roman Period when the Antioch city reached its golden age. The basin also sustained a high seismic activity (M≥7) as it is a releasing step-over along the Dead Sea Fault. The study focuses on the sedimentary record of the Amik Lake occupying the central part of the Basin. Our objective is to constrain major paleo-environmental changes in the area over the last 4000 years and to unravel possible human impacts on the sedimentation. A diverse array of complementary methods was applied on the 6 m long record. High resolution of mineralogical (XRD) and geochemical (XRF) analyses were performed. Quantitative mineralogical phases of sediments by the Rietveld method were computed using Topaz software. The age of the record is constrained combining radionuclide and radiocarbon dating, and checked using the correlation between the earthquake history and rapidly deposited layer identified. A high sedimentation rate of 0.12 cm/yr was inferred at the coring site. The 4000 years old record shows that significant fluctuations of the lake level and the riverine system inflow into the Amik Lake occurred. The Late Bronze lowstand leaded to punctual dryings of the lake at the end of the Bronze/Iron transition marked by the collapse of the Hittite Empire and during the Dark ages. At that time, the riverine was carrying a large terrigenous input linked to strong soil erosion related to deforestation, exploitation of mineral resources and the beginning of upland cultivation. During the Roman Period and in the later periods, upland soils were partly depleted and the riverine system completely transformed by channelization that leaded to a mashification of the Amik Basin. Chemical and mineralogical composition of sediments is quite diversified reflecting the significant geological variation of drainage basins. Abundant calcareous minerals, especially calcite, aragonite, dolomite and small amount of wollastonite characterize the different sedimentary levels recorded in the lake. Levels relatively rich in fluorite, richerite, enstatite, and wollastonite are a result of the erosion of the ophiolitic rocks from the surrounding Amanos Mountains. These levels are interpreted as corresponding to relatively high erosive periods, while more humid periods lead to more intensive weathering and consequently to the dominance of kaolinite, muscovite/illite and talc more advanced in the relative stability scale, indicating a climate with contrasting seasons. During the most recent Period a marked increase in terrigeneous minerals associated with a rise in dolomite indicates ungoing erosion as well as the drying-out of the lake. [less ▲]

Detailed reference viewed: 49 (7 ULg)
Full Text
See detailImpact of tillage practices on soil moisture dynamics in a temperate climate: potential of 3-D electrical resistivity tomography (ERT)
Chelin, Marie ULg; Hiel, Marie-Pierre ULg; Blanchy, Guillaume et al

Poster (2016, April 12)

Adapted agricultural soil management practices can enhance soil health by providing improved aggregate stability and soil structural quality. Hence water infiltration may be improved and plant water ... [more ▼]

Adapted agricultural soil management practices can enhance soil health by providing improved aggregate stability and soil structural quality. Hence water infiltration may be improved and plant water availability increased. In this study, we aim at quantifying the effect of tillage practices on the water dynamics in a loamy soil under temperate climate (Gembloux, Belgium). Therefore, we evaluated the ability of electrical resistivity tomography to estimate the water content at the field scale and under complex field conditions: varying pore water conductivity, rainfall, crop water uptake, root growth, varying temperature and changing soil structure due to tillage practices. During the summer of 2015, we studied four different treatments: conventional spring and winter tillage, strip tillage and a bare soil. We used ERT to estimate the spatio-temporal distribution of soil moisture. In each of the plots, 2 time-domain reflectometry (TDR) probes and 2 suction cups were installed. A calibration trench was constructed with 4 electrodes, 1 TDR probe and 1 temperature sensor at 4 different depths. We quantified changes of porosity over the growing season using X-ray tomography. Combining these data, we will investigate and quantify the effect of simultaneously changing pore water conductivity, soil porosity, soil temperature and soil moisture on the effectiveness of time-lapse ER measurements as a proxy for soil moisture changes under different tillage practices. [less ▲]

Detailed reference viewed: 15 (2 ULg)
Full Text
Peer Reviewed
See detailGenotypic characterization of T. mentagrophytes complex strains circulating in Belgium with the Diversilab® system.
SACHELI, Rosalie ULg; Utri, Tania ULg; ADJETEY BAHUN, Akolé ULg et al

Poster (2016, April 09)

Background Infections due to the zoophilic dermatophyte Arthroderma benhamiae are being more frequently diagnosed in Belgium since a few years. The most common source of infection is guinea pigs. This ... [more ▼]

Background Infections due to the zoophilic dermatophyte Arthroderma benhamiae are being more frequently diagnosed in Belgium since a few years. The most common source of infection is guinea pigs. This species which is referred to the Trichophyton species of A.benhamiae can cause tinea capitis, tinea corporis, tinea manus and more frequently tinea faciei. These strains appear with a bright yellow thallus in culture and do not easily sporulate making them difficult to identify. Sequencing of these strains reveals “Arthroderma benhamiae”. At the contrary white strains of T. mentagrophytes complex are identified by sequencing as “T. mentagrophytes variety interdigitale” or T. interdigitale. The aim of the study is the evaluation of the genetic heterogeneity of these two subtypes of the T. mentagrophytes complex by using the DiversiLab® system. Material and methods 32 strains were collected by the National Reference Center for mycoses between 2012 and 2015. The fungal strains were identified by microscopy or ITS sequencing. All strains appearing white with a yellow pigment in culture and being identified as “A. benhamiae” by DNA sequencing were included as well reference strains. Some selected strains appearing white in culture and being identified as “T. mentagrophytes var. interdigitale” by DNA sequencing were also included. The genotypic analysis was performed by the DiversiLab® system (bioMérieux) by DNA fingerprinting generation. Results Both groups showed huge differences in DNA fingerprints. The similarity calculated by the DiversiLab® tool between the two groups was 70%. This reflects a high genotypic heterogeneity regarding the two types of strains analyzed. This is surprising given that both groups belong to the same species complex. The comparison of these two distinct DNA fingerprints with the mold database of bioMérieux generated identification as “T. mentagrophytes” for both groups. We noticed that the library contained two distinct patterns of DNA fingerprints (profile 1, strains MK55-60 and profile 2, strains MK138-143). Yellow strains were highly similar to profile 1 and white strains were highly similar to profile 2. Unfortunately, no additional information regarding the subspecies implicated could be obtained from the manufacturer. However, this study demonstrates that it may represent respectively “yellow strains types Trichophyton species of A. benhamiae” and “ white strains types T. interdigitale”. Conclusion This study highlights the genotypic differences between two types of strains belonging to the T. mentagrophytes species complex. Yellow strains which incidence is increasing in Belgium are clearly different from other strains previously characterized and the DiversiLab® method shows a high efficiency for discriminating between these two species difficult to separate by microscopy. [less ▲]

Detailed reference viewed: 21 (3 ULg)
Full Text
See detailRecent progress in the development of a hydrogen maser in the TE111 mode
Van Der Beken, Emeline ULg; Léonard, Daniel; Counet, Arnaud et al

Poster (2016, April 06)

We present the recent progress in the development of a hydrogen maser in the unusual TE111 mode. In contrast to standard hydrogen maser that exploits the TE011 mode, the TE111 mode allows one to design ... [more ▼]

We present the recent progress in the development of a hydrogen maser in the unusual TE111 mode. In contrast to standard hydrogen maser that exploits the TE011 mode, the TE111 mode allows one to design hydrogen masers with significant reduced dimensions which represents a huge benefit for space applications and in particular for the global positioning system. We present in details the different parts of our model : cavity with a thin Teflon sheet, magnetic shielding, temperature control of the maser... [less ▲]

Detailed reference viewed: 35 (6 ULg)
Full Text
See detailGeneralized Pascal triangle for binomial coefficients of finite words
Stipulanti, Manon ULg; Leroy, Julien ULg; Rigo, Michel ULg

Poster (2016, April 05)

Abstract. We introduce a generalization of Pascal triangle based on bino- mial coefficients of finite words. These coefficients count the number of times a word appears as a subsequence of another finite ... [more ▼]

Abstract. We introduce a generalization of Pascal triangle based on bino- mial coefficients of finite words. These coefficients count the number of times a word appears as a subsequence of another finite word. Similarly to the Sierpinski gasket that can be built as the limit set, for the Hausdorff distance, of a convergent sequence of normalized compact blocks extracted from Pascal triangle modulo 2, we describe and study the first properties of the subset of [0, 1] × [0, 1] associated with this extended Pascal triangle modulo a prime p. [less ▲]

Detailed reference viewed: 28 (9 ULg)
See detailCoupling the Electron and Phonon Baths via the Boltzmann Transport Equations
Pike, Nicholas ULg

Poster (2016, April 03)

Detailed reference viewed: 17 (4 ULg)
Peer Reviewed
See detailEpisodic memory and aging: The effect of perceptual processing fluency on recognition memory processes
Bastin, Christine ULg; Willems, Sylvie ULg

Poster (2016, April 03)

Normal aging is characterized by decreased recollection, but better preserved familiarity. Memory tasks that facilitate the use of familiarity should allow attenuating age-related differences in memory ... [more ▼]

Normal aging is characterized by decreased recollection, but better preserved familiarity. Memory tasks that facilitate the use of familiarity should allow attenuating age-related differences in memory. The study tested two hypotheses: (1) can the reliance on familiarity during recognition memory be promoted by increasing the difference in perceptual processing fluency between old and new items; (2) can this manipulation reduce age-related difficulties in episodic memory? Twenty-four young and 24 older adults performed two verbal recognition memory tasks. In the No-Overlap task, target words and new words did not share any letter. Prior exposition to the target words thus induced increased processing fluency of the words and letters, so that fluency difference was a salient and reliable cue to discriminate between old and new words. In the Overlap task, target and new words had letters in common, so fluency cues were less useful. Recollection and familiarity was assessed with the Remember/Know/Guess paradigm. The results showed an age effect on recollection but intact familiarity. Moreover, (1) memory performance was better in the No Overlap than the Overlap task, with a greater hit rate and a smaller false alarm rate associated with familiarity. And, (2) age-related differences in recognition accuracy (hits – false alarms) were significantly attenuated in the No Overlap task compared to the Overlap task. These findings suggest that minimizing the perceptual similarity between targets and distractors, and thus increasing processing fluency differences, allowed to reduce the effect of age on recognition memory performance by facilitating the use of familiarity. [less ▲]

Detailed reference viewed: 32 (4 ULg)
Peer Reviewed
See detailLa violence conjugale : persévérance vs abandon des auteurs masculins lors de leur participation à un groupe de responsabilisation
Di Piazza, Laetitia ULg; Kowal, Cécile; Hodiaumont, Fabienne et al

Poster (2016, April 02)

Le phénomène d'abandon thérapeutique lors de suivi dans le cadre de violence conjugale se trouve au cœur des préoccupations des intervenants venant en aide aux auteurs de ces violences. Ces thérapies en ... [more ▼]

Le phénomène d'abandon thérapeutique lors de suivi dans le cadre de violence conjugale se trouve au cœur des préoccupations des intervenants venant en aide aux auteurs de ces violences. Ces thérapies en groupe de responsabilisation se caractérisent par un taux d'abandon élevé, avec le risque potentiel de récidive associé. L’objectif de cette étude est d’identifier d’éventuelles caractéristiques intrapsychiques permettant de distinguer les usagers qui terminent leur suivi thérapeutique de ceux qui abandonnent au cours de celui-ci. Pour ce faire, une comparaison au sein de ces deux groupes d’individus (abandon : n=23 ; accomplissement du suivi : n=28) a été réalisée à partir de données sociodémographiques et de variables psychologiques spécifiques évaluées par des questionnaires auto-administrés (TAS-20, BIS-11, BDI, PBI, LEDS). Les résultats statistiques montrent que l’âge, le nombre d’événements stressants vécus au cours des six mois précédents l’évaluation et l’appréciation du soutien à l’autonomie perçu vis-à-vis de leur père sont les seules variables qui diffèrent significativement entre les deux groupes. Les autres dimensions mesurées telles que la dépression, l’alexithymie et l’impulsivité, quant à elles, ne produisent pas de résultats significatifs entre les deux groupes. Il semble donc, en définitive, que les hommes plus jeunes présenteront plus de risque de quitter le programme de façon précoce. Malgré tout, l’ensemble de ces résultats pose un sérieux défi pour les intervenants au sein des services d’aide spécialisés. En effet, si tous les individus qui participent aux groupes de responsabilisation présentent les mêmes caractéristiques intrapsychiques, comment prédire, mais surtout accrocher ceux qui abandonneront le programme ? [less ▲]

Detailed reference viewed: 16 (2 ULg)
Peer Reviewed
See detailAnodal transcranial direct stimulation (tDCS) targeting the anterior cingulate gyrus for the preventive treatment of chronic cluster headache: a proof of concept trial.
MAGIS, Delphine ULg; D'Ostilio, Kevin ULg; Cosseddu, Anna et al

Poster (2016, April)

Background There is a need for better treatments in chronic cluster headache (CCH). In responders to percutaneous occipital nerve stimulation, the subgenual anterior cingulate gyrus (sACG) was found ... [more ▼]

Background There is a need for better treatments in chronic cluster headache (CCH). In responders to percutaneous occipital nerve stimulation, the subgenual anterior cingulate gyrus (sACG) was found hypermetabolic (Magis et al. 2011). We reasoned that activation of this area by transcranial neurostimulation could be effective in CCH. Aim To explore the preventive effect of anodal (i.e. activating) transcranial direct current stimulation (tDCS) targeting the anterior cingulate gyrus in CCH patients. Method & subjects Difficult-to-treat CCH patients with a stable preventive drug regimen applied tDCS (2mA) interictally in 20-minute daily sessions for 4 weeks with the anode positioned over the forehead (FpZ), the cathode over the C7 spinous process. Therapeutic effects were monitored with paper diaries. Results Nineteen patients were enrolled up to now. In 13 patients who completed the trial, mean weekly attack frequency decreased by 38% after 4 weeks of daily stimulation (W-test: p = 0.002). The 50% responder rate was 54%. Patients (n=12) reported an improvement in headache impact, as shown by 5-point decrease in the mean HIT-6 score (from 67 to 62, p = 0.02). In 10 patients who were followed up after the treatment period, the benefit remained stable up to 4 weeks after the last stimulation. The first 3 enrolled patients had superficial skin burns under the adhesive cathode electrode. Sponge electrodes were therefore used in all subsequent patients without any adverse effect. Conclusion Anodal tDCS targeting the anterior cingulate gyrus seems promising for the preventive treatment of chronic cluster headache as suggested by this ongoing proof-of-concept trial. Use of adhesive electrodes is not recommended. [less ▲]

Detailed reference viewed: 22 (1 ULg)
Full Text
See detailGlobal simulation of UV atmospheric emissions on Mars
González-Galindo; López-Valverde; Forget et al

Poster (2016, April)

Detailed reference viewed: 9 (1 ULg)
Full Text
See detailMars Topography Investigated Through the Wavelet Leaders Method: a Multidimensional Study of its Fractal Structure
Deliège, Adrien ULg; Kleyntssens, Thomas ULg; Nicolay, Samuel ULg

Poster (2016, April)

This work examines the scaling properties of Mars topography through a wavelet-based formalism. We conduct exhaustive one-dimensional (both longitudinal and latitudinal) and two-dimensional studies based ... [more ▼]

This work examines the scaling properties of Mars topography through a wavelet-based formalism. We conduct exhaustive one-dimensional (both longitudinal and latitudinal) and two-dimensional studies based on Mars Orbiter Laser Altimeter (MOLA) data using the multifractal formalism called Wavelet Leaders Method (WLM). This approach shows that a scale break occurs at approximately 15 km, giving two scaling regimes in both 1D and 2D cases. At small scales, these topographic profiles mostly display a monofractal behavior while a switch to multifractality is observed in several areas at larger scales. The scaling exponents extracted from this framework tend to be greater at small scales. In the 1D context, these observations are in agreement with previous works and thus suggest that the WLM is well-suited for examining scaling properties of topographic fields. Moreover, the 2D analysis is the first such complete study to our knowledge. It gives both a local and global insight on the scaling regimes of the surface of Mars and allows to exhibit the link between the scaling exponents and several famous features of the Martian topography. These results may be used as a solid basis for further investigations of the scaling laws of the Red planet and show that the WLM could be used to perform systematic analyses of the surface roughness of other celestial bodies. [less ▲]

Detailed reference viewed: 13 (3 ULg)
Full Text
See detailRhizosecreted proteases inhibition for the improvement of recombinant protein production in Arabidopsis thaliana
Lallemand, Jérôme ULg; Périlleux, Claire ULg; Tocquin, Pierre ULg

Poster (2016, April)

Plant-based biopharmaceuticals have gained a lot of interest in the past decade due to their reduced cost and relative safety compared to mammalian cell cultures. While the first plant-made recombinant ... [more ▼]

Plant-based biopharmaceuticals have gained a lot of interest in the past decade due to their reduced cost and relative safety compared to mammalian cell cultures. While the first plant-made recombinant proteins are now reaching the market, the production systems still need improvements to maximize their competitiveness. Optimizing production hosts requires the identification and subsequent inhibition of the most active endogenous peptidases, proteolysis being one of the main factors limiting yields. The aim of our study was to identify root-secreted proteases of Arabidopsis thaliana involved in target protein degradation (BSA) and inhibit them in vivo. Biochemical analyses identified serine proteases as the main class responsible for BSA degradation. An RT-qPCR experiment led to the choice of the serine protease gene SBT4.12 and its homologs as targets for an amiRNA-mediated silencing approach. Arabidopsis amiRNA-expressing lines showed lower levels of expression for SBT4.12 and reduced proteolytic activity in their rhizosecreted extracts. Crossing these lines with recombinant protein producing lines could lead to an improved production platform for proteins of interest. [less ▲]

Detailed reference viewed: 35 (7 ULg)
See detailAlpha-synuclein as biomarker in Parkinson’s disease: strategies for detection in CGE-LIF
Houbart, Virginie ULg; Napp, Aurore ULg; Rudaz, Serge et al

Poster (2016, April)

Detailed reference viewed: 23 (9 ULg)
Peer Reviewed
See detailNon-invasive vagus nerve stimulation with the gammaCore® in healthy subjects: is there electrophysiological evidence for activation of vagal afferents ?
Schoenen, Jean ULg; NONIS, Romain ULg; D'Ostilio, Kevin ULg et al

Poster (2016, April)

Abstract: Background Non-invasive vagus nerve stimulation (nVNS) with the gammaCore® improves migraine and cluster headache. Animal experiments suggest that nVNS acts via stimulation of vagal afferents ... [more ▼]

Abstract: Background Non-invasive vagus nerve stimulation (nVNS) with the gammaCore® improves migraine and cluster headache. Animal experiments suggest that nVNS acts via stimulation of vagal afferents, but proof in humans is lacking. Vagal somatosensory evoked potentials (vSEP) are identified after invasive VNS or transcutaneous stimulation of auricular vagal branches, but late components could be muscle artifacts. Objective To search in healthy volunteers for reliable vSEP during nVNS with the gammaCore® Methods In 12 healthy subjects (7males) evoked potentials were recorded at A1/A2 (ref Cz) and C3/C4 (ref F3/F4) during 2-minute stimulation over left/right cervical vagus nerve with the gammaCore® (25Hz, 6-24V) and during stimulation over the inner tragus with a monopolar stimulator (2Hz, 50 stimuli, mean intensity 8mA). Results We identified 3 reproducible peaks P1, N1, P2 in 10 patients on the side of the gammaCore® stimulation at mean latencies of 2.05ms, 5.20ms and 9.13ms. P1-N1 amplitude increased significantly (p<0.01) with increasing voltage from 0.04μV to 0.52μV (C3/C4) and from 0.13µV to 2.04μV (A1/A2) respectively at 10V and 30V. Inner tragus stimulation elicited P1, N1, P2 peaks with shorter mean latencies (2.21ms, 3.72ms, 5.71ms) and a mean P1-N1 amplitude (A1/A2) of 5.0µV. When the gammaCore® was placed over the sternocleidomastoid muscle, there were no reproducible evoked potentials. Conclusion Non-invasive transcutaneous stimulation of the cervical vagus nerve with the gammaCore® elicits evoked potentials similar to those found with implanted electrodes or stimulation of Arnold’s nerve in the outer ear. The gammaCore®-evoked potentials increase in amplitude with stimulation intensity and disappear when the stimulator is positioned over neck muscles, suggesting that they are not muscle artifacts. Their short latency is compatible with their generation at the level of the foramen jugulare. The therapeutic effects reported with the gammaCore® in primary headaches can thus be mediated by genuine activation of vagus nerve afferents. [less ▲]

Detailed reference viewed: 35 (1 ULg)
Full Text
Peer Reviewed
See detailUnderground Pumped Storage Hydropower using abandoned open pit mines: influence of groundwater seepage on the system efficiency
Pujades, Estanislao ULg; Bodeux, Sarah ULg; Orban, Philippe ULg et al

Poster (2016, April)

Pumped Storage Hydropower (PSH) plants can be used to manage the production of electrical energy according to the demand. These plants allow storing and generating electricity during low and high demand ... [more ▼]

Pumped Storage Hydropower (PSH) plants can be used to manage the production of electrical energy according to the demand. These plants allow storing and generating electricity during low and high demand energy periods, respectively. Nevertheless, PSH plants require a determined topography because two reservoirs located at different heights are needed. At sites where PSH plants cannot be constructed due to topography requirements (flat regions), Underground Pumped Storage Hydropower (UPSH) plants can be used to adjust the electricity production. These plants consist in two reservoirs, the upper one is located at the surface (or at shallow depth) while the lower one is underground (or deeper). Abandoned open pit mines can be used as lower reservoirs but these are rarely isolated. As a consequence, UPSH plants will interact with surrounding aquifers exchanging groundwater. Groundwater seepage will modify hydraulic head inside the underground reservoir affecting global efficiency of the UPSH plant. The influence on the plant efficiency caused by the interaction between UPSH plants and aquifers will depend on the aquifer parameters, underground reservoir properties and pumping and injection characteristics. The alteration of the efficiency produced by the groundwater exchanges, which has not been previously considered, is now studied numerically. A set of numerical simulations are performed to establish in terms of efficiency the effects of groundwater exchanges and the optimum conditions to locate an UPSH plant. [less ▲]

Detailed reference viewed: 16 (4 ULg)
Full Text
Peer Reviewed
See detailImpact of tillage on N2O and CO2 efflux in an agricultural crop
Lognoul, Margaux ULg; Theodorakopoulos, Nicolas ULg; Hiel, Marie-Pierre ULg et al

Poster (2016, April)

In an experiment conducted in the Belgian loess belt between June and October 2015, the effect of two tillage treatments (CT - conventional tillage and RT - reduced tillage) on CO2 and N2O fluxes ... [more ▼]

In an experiment conducted in the Belgian loess belt between June and October 2015, the effect of two tillage treatments (CT - conventional tillage and RT - reduced tillage) on CO2 and N2O fluxes exchanged by a maize crop were compared. Fluxes were measured using two fully automated sets of dynamic closed chambers, allowing a 4.5h temporal resolution. Soil water content and temperature were also monitored as well as pH, total N (TN) and total organic C (TOC) content. [less ▲]

Detailed reference viewed: 57 (7 ULg)
Full Text
Peer Reviewed
See detailInfluence of the ionospheric model on DCB computation and added value of LEO satellites
Wautelet, Gilles ULg; Lestarquit, Laurent; Loyer, Sylvain et al

Poster (2016, April)

In order to compute inter-frequency Differential Code Biases (DCBs), the Geometry-Free combination of a GNSS signal pair needs to be corrected from the ionospheric refraction effect. Such information is ... [more ▼]

In order to compute inter-frequency Differential Code Biases (DCBs), the Geometry-Free combination of a GNSS signal pair needs to be corrected from the ionospheric refraction effect. Such information is obtained using either Global Ionospheric Maps (GIMs) or local models. In this work we investigate the influence of GIMs on the final value and precision of DCB solution. The study covers different ionospheric conditions, ranging from very quiet ionospheric background up to a severe ionospheric storm. In a first step, the Slant Total Electron Content (STEC) between GIMs is assessed as a function of receiver latitude, elevation mask and ionospheric conditions. Then, daily DCBs are estimated using these different GIMs, receiver and satellite contributions being separated using a zero-mean constraint. At last, an independent estimation of DCBs is performed using Low Earth Orbit (LEO) observations (such as JASON's GPS data). This solution is compared with our ground network solution and with DCBs coming from Analysis Centers (ACs) of the International GNSS Service providing ionospheric and DCB solutions. [less ▲]

Detailed reference viewed: 13 (1 ULg)
Full Text
See detailInfluence of plant roots on electrical resistivity measurements of cultivated soil columns
Maloteau, Sophie ULg; Blanchy, Guillaume ULg; Javaux, Mathieu et al

Poster (2016, April)

The goals of this experiment are to quantify the effect of plant roots on electrical resistivity of the soil subsurface and to map a plant roots system in space and time with ERT technique in a soil ... [more ▼]

The goals of this experiment are to quantify the effect of plant roots on electrical resistivity of the soil subsurface and to map a plant roots system in space and time with ERT technique in a soil column. For this research, it is assumed that roots system affect the electrical properties of the rhizosphere. Indeed the root activity (by transporting ions, releasing exudates, changing the soil structure,…) will modify the rhizosphere electrical conductivity (Lobet G. et al, 2013). This experiment is included in a bigger research project about the influence of roots system on geophysics measurements. Measurements are made on cylinders of 45 cm high and a diameter of 20 cm, filled with saturated loam on which seeds of Brachypodium distachyon (L.) Beauv. are sowed. Columns are equipped with electrodes, TDR probes and temperature sensors. Experiments are conducted at Gembloux Agro-Bio Tech, in a growing chamber with controlled conditions: temperature of the air is fixed to 20°C, photoperiod is equal to 14 hours, photosynthetically active radiation is equal to 200 µmol m-2s-1, and air relative humidity is fixed to 80 %. Columns are fully saturated the first day of the measurements duration then no more irrigation is done till the end of the experiment. [less ▲]

Detailed reference viewed: 9 (1 ULg)
Full Text
See detailNew elicitors as biocontrol tools to protect wheat against Septoria Tritici Blotch
Le Mire, Géraldine ULg; SIAH, Ali; Jijakli, Haissam ULg

Poster (2016, April)

Wheat is one of the most cultivated crops in the European Union. This cereal must however face important losses every year due to a major foliar disease known as Septoria Tritici Blotch (STB) caused by ... [more ▼]

Wheat is one of the most cultivated crops in the European Union. This cereal must however face important losses every year due to a major foliar disease known as Septoria Tritici Blotch (STB) caused by the fungus Zymoseptoria tritici. Disease control mainly depends on phytosanitary products. However, conventional agriculture is evolving towards more sustainable practices, out of respect for human health and the environment. Elicitors are considered as promising biological control tools and draw major interest in Integrated Pest Management strategies. These plant-immunity triggering compounds induce a general systemic resistance of the plant to a large spectrum of diseases. This study focuses on the screening of nine potential elicitors to protect winter wheat against Zymoseptoria tritici. Greenhouse trials were carried out to measure the ability of the different products to reduce disease foliar symptoms (necrosis, chlorosis and pycnidia). In addition, the biocide activity of these products towards the pathogen was evaluated under greenhouse and laboratory conditions. Furthermore, the modes of action of the best elicitors were investigated by studying the activity of some key defense enzymes of wheat. The corresponding results will be presented and discussed with the perspective to choose the two best elicitors for field trials and undertake further investigations on the signaling pathways triggered in the plant. [less ▲]

Detailed reference viewed: 25 (3 ULg)
Full Text
Peer Reviewed
See detailFirst steps of the regional climate model MAR over the Euro-CORDEX domain
Scholzen, Chloé ULg; Fettweis, Xavier ULg

Poster (2016, April)

In the framework of the Euro-CORDEX initiative, the Laboratory of Climatology of the University of Liège, Belgium, is currently using the regional climate model MAR (for “Modèle Atmosphérique Régional” ... [more ▼]

In the framework of the Euro-CORDEX initiative, the Laboratory of Climatology of the University of Liège, Belgium, is currently using the regional climate model MAR (for “Modèle Atmosphérique Régional”) to simulate the past, present and future climate over Europe. Simulations are to be performed for both available resolutions over the Euro-CORDEX domain, namely 0.11 deg. (12.5 km) and 0.44 deg. (50 km). Historical and present-day runs (1979-2015) will use the ERA-Interim and the NCEP/NCAR-v1 reanalyses as boundary conditions, whereas future projections will be driven by two selected GCMs from the CMIP5 database: NorESM1-M and MIROC5. All CMIP5-GCMs were previously compared against ERA-Interim reanalysis data in terms of their ability to represent the current mean climate over Europe. The GCMs also underwent a statistical classification based on the calculation of skill-scores evaluating for instance 850 hPa temperature and 500 hPa geopotential height. Several settings and parameters were tested in order to calibrate the regional climate model MAR over the Euro-CORDEX domain. MAR is to be validated against observations from the European Climate Assessment & Dataset (ECA&D). The final aim of this study is to assess the performance of MAR in comparing its results to other RCMs used within the Euro-CORDEX initiative. [less ▲]

Detailed reference viewed: 17 (7 ULg)
Full Text
See detailAnalyse qualitative et quantitative des populations de norovirus murins générées lors d’infections in vitro synchrones et asynchrones avec des souches homologues : détection de phénomènes de dominance, d’interférence due aux particules non-infectieuses et d’exclusion à la surinfection
Di Felice, Elisabetta; Ludwig, Louisa ULg; Toffoli, Barbara et al

Poster (2016, March 24)

RÉSUMÉ Buts du travail La recombinaison est un des mécanismes moteurs de l’évolution génétique des norovirus. Malgré une détection fréquente de séquences recombinantes à partir d’échantillons de terrain ... [more ▼]

RÉSUMÉ Buts du travail La recombinaison est un des mécanismes moteurs de l’évolution génétique des norovirus. Malgré une détection fréquente de séquences recombinantes à partir d’échantillons de terrain, la reproduction du phénomène de recombinaison en conditions de laboratoire semble difficile. Utilisant le modèle du norovirus murin, cette étude a pour objectif d’évaluer de manière qualitative et quantitative les populations virales, y compris potentiellement recombinantes, générées lors de variations des conditions de temps et de multiplicité d’infection dans des expériences de coinfections ou de surinfections in vitro. Méthodes Des cellules RAW264.7 ont été inoculées par deux souches homologues de norovirus murins (infection primaire : Wu20 ; surinfection : CW1) en utilisant des multiplicités d’infection (MOI : Wu20 = 1; CW1= 0.1, 1 ou 10) et des temps d’inoculation (surinfection après un délai allant de 0 minutes à 24 heures) variables. Les surnageants ont été prélevés 24h post-surinfection et une quantification moléculaire discriminante sur la région 5’ du génome a été réalisée. Des cellules ont été ré-inoculées par ces surnageants et 36 isolats ont été amplifiés. Ces isolats ont été caractérisés moléculairement comme de type CW1, Wu20 ou recombinant par une méthode discriminante sur leurs extrémités génomiques 3’ et 5’. Les recombinants potentiels ont été séquencés sur la région génomique classiquement impliquée dans la recombinaison (chevauchement ORF 1/2). Résultats et discussion L’analyse des ratios des isolats a montré une tendance à une dominance potentielle de Wu20 sur CW1 pour les conditions de MOI relatives 0.1/1 et 1/1 avec un phénomène d’exclusion à la surinfection entre les temps t4 (4h post-infection primaire) et t8. Cependant, cette tendance n’a pas été détectée dans la condition de MOI relative 10/1. Ceci suggère une hypothèse de présence de particules défectives interférentes (PDI) dans la population de Wu20 qui pourrait interférer avec les étapes précoces de l’attachement et de l’entrée et donc modifier les ratios attendus 24h post-infection. La comparaison des ratios de copies génomiques a soutenu l’hypothèse de présence de PDI dans la population de Wu20 avec des ratios différents de ceux logiquement escomptés aux MOI relatives 0.1/1 et 1/1, et qui se sont vérifiés cette fois en condition 10/1 (condition dans laquelle CW1 peut retrouver une chance réelle dans la compétition à l’attachement et à la pénétration). Cependant le temps t1 de cette condition a dévié clairement de la tendance générale et pourrait constituer une population virale de choix pour la présence de recombinants ou suggérer un autre mécanisme par lequel CW1 pourrait momentanément être dominant par rapport à Wu20. L’exclusion à la surinfection a également pu être corroborée par l’analyse moléculaire quantitative. Trois isolats ont été détectés comme des recombinants potentiels mais les séquençages n’ont pu les confirmer. Les évènements de recombinaison pourraient avoir eu lieu sur une autre région que celle classiquement décrite. Cette étude permet de montrer que la composition de la population virale peut avoir un effet majeur sur la compétition entre deux norovirus. Elle suggère également l’existence d’un mécanisme d’exclusion à la surinfection. Elle confirme enfin que malgré les fréquentes détections de souches recombinantes in silico, le phénomène de recombinaison est difficile à reproduire in vitro chez les norovirus. [less ▲]

Detailed reference viewed: 12 (2 ULg)
Full Text
Peer Reviewed
See detailEtude de dermatophytes isolés dans les services de revalidation et physiothérapie d’une structure hospitalière en région Liégeoise (Belgique)
SACHELI, Rosalie ULg; Utri, Tania ULg; Abdel-Sadick, Hidjab Abdoulaye ULg et al

Poster (2016, March 23)

Objectifs : Les dermatophytes sont responsables d’infections de la peau, des ongles et du cuir chevelu. Les espèces anthropophiles peuvent se transmettre d’une personne à une autre par un simple contact ... [more ▼]

Objectifs : Les dermatophytes sont responsables d’infections de la peau, des ongles et du cuir chevelu. Les espèces anthropophiles peuvent se transmettre d’une personne à une autre par un simple contact. Leur présence en milieu sportif (salles de sport, piscine, tatamis), douches collectives, vestiaires des écoles, a été largement décrite. Par contre il existe peu de littérature concernant les établissements de soins. C’est pourquoi, nous nous sommes intéressés au risque potentiel d’infection par des dermatophytes en milieu hospitalier et particulièrement dans les salles de kinésithérapie et de revalidation ainsi que dans une piscine du CHU de Liège. Matériel et méthodes : Trois sites du CHU de Liège ont été investigués: le site du Sart Tilman (ST), le site Ourthe Amblève (OA) et le site Notre-Dame des Bruyères (NDB). Les prélèvements ont été effectués en salle de revalidation et kinésithérapie ainsi qu’à la piscine de revalidation. Ces prélèvements ont été réalisés sur les surfaces à l’aide de géloses de contact (milieu de Sabouraud/chloramphénicol/actidione/gentamicine, Tritium Microbiologie, Pays-bas). L’identification des espèces fongiques a été réalisée par observation macro-microscopique des cultures, spectrométrie de masse (Maldi-Tof) et séquençage moléculaire. Résultats : Au total, 552 prélèvements ont été réalisés parmi lesquels 15 dermatophytes ont été recensés (2,72%). On retrouve: 7 T. rubrum, 7 T. interdigitale, 1 T. mentagrophytes var. mentagrophytes. Sur le site ST, 207 prélèvements ont été effectués parmi lesquels 4 T. rubrum, 1 T. interdigitale et 1 T. mentagrophytes var. mentagrophytes (zoophile). Sur le site OA, parmi les 226 prélèvements effectués, 4 Trichophyton interdigitale et 3 Trichophyton rubrum ont été retrouvés. Aucun dermatophyte n’a été isolé de l’eau de piscine ou pédiluve. Sur le site de NDB, sur 119 prélèvements, seuls 2 isolats de Trichophyton interdigitale ont été identifiés. Les prélèvements positifs pour les dermatophytes concernent des tapis de gymnastique, vélos, rameurs, balances, trampolines, demi-sphères d’équilibre, table de kinésithérapie, sols de douches et vestiaires de la piscine. Conclusion Grâce à ces investigations, nous avons pu mettre en évidence sur le matériel de revalidation et les sols des vestiaires, la présence de deux espèces anthropophiles, T. rubrum et T. interdigitale fréquemment impliquées dans les cas d’onychomycoses et atteintes cutanées. Une souche zoophile de T. mentagrophytes a également été mise en évidence. Cette étude démontre qu’un renforcement de la fréquence de nettoyage des sols et des instruments utilisés dans les salles de sport du CHU de Liège est nécessaire de façon à minimaliser les risques de contamination de patients et du personnel médical. [less ▲]

Detailed reference viewed: 16 (1 ULg)
Full Text
See detailClinical and molecular classification of glioblastoma patients
Lambert, Jérémy ULg; Kaoma, Tony; Van Dyck, Eric et al

Poster (2016, March 19)

Detailed reference viewed: 20 (1 ULg)
Peer Reviewed
See detailRecollection versus familiarity in normal aging and in mild cognitive impairment: Impact of test format
Gilsoul, Jessica ULg; Simon, Jessica ULg; SALMON, Eric ULg et al

Poster (2016, March 18)

Objectives. Memory retrieval typically involves a combination of recollection and familiarity. However, test format can promote one or the other process (Norman & O’Reilly, 2003). The aim of this study ... [more ▼]

Objectives. Memory retrieval typically involves a combination of recollection and familiarity. However, test format can promote one or the other process (Norman & O’Reilly, 2003). The aim of this study was to investigate the impact of test format on recollection and familiarity in normal aging and in mild cognitive impairment (MCI). Methods. Seventy young participants (18-30 years), 65 “younger-old” (55- 69 years), 53 “older-old” (70-85 years), and 13 MCIs (55-82 years) were enrolled. In the “forced-choice” task, they had to recognize which picture, among three, was presented during the encoding stage. In the “yes/no” task, they had to judge whether each item, successively presented, was previously seen or not. In each task, they had to give a “Remember/Know/Guess” judgment. Results. Group × Format repeated measures ANOVAs revealed that young people had better recognition performance (d’) than “younger-old”, which were better than “older-old” and MCIs. Moreover, young people used familiarity more accurately than both groups of old participants and MCIs, with MCIs being equivalent to “younger-old” and “older-old”. However, MCIs displayed a high rate of familiarity-based false alarms. The resort to recollection decreased with age and in MCIs. Finally, Group × Format interaction revealed that young people (but not the other groups) could use recollection more often in the “forcedchoice” task compared to the “yes/no” task. Conclusions. Recollection and familiarity decline progressively in healthy aging. In MCI, recollection is more affected than familiarity, but patients demonstrated a more liberal use of familiarity. Finally, test format did not influence strongly the results. [less ▲]

Detailed reference viewed: 27 (3 ULg)
Full Text
See detailRegain of fitness through in vitro replication for a recombinant murine norovirus
de Oliveira-Filho, Edmilson; Ludwig, Louisa ULg; Toffoli, Barbara et al

Poster (2016, March 18)

INTRODUCTION Molecular mechanisms driving norovirus evolution are the accumulation of point mutations and recombination. Recombination can create considerable changes in viruses, allowing for complete ... [more ▼]

INTRODUCTION Molecular mechanisms driving norovirus evolution are the accumulation of point mutations and recombination. Recombination can create considerable changes in viruses, allowing for complete antigenic shifts, host jumps and fitness and pathogenesis modifications. Mathijs et al. recently isolated a viable recombinant murine norovirus (RecMNV) in vitro after coinfection of two parental MNV strains (MNV1-CW1 and -WU20) in a mouse leukaemic monocyte-macrophage cell line (RAW 264.7). The ensuing RecMNV possessed reduced in vitro fitness compared to its parental strains but has also been shown to have retained in vivo infectivity (Mathijs et al, submitted). The aim of this study was to follow the replicative and genetic adaptations of RecMNV over serial in vitro passages in order to characterise its capability of replicative fitness adaptation. MATERIALS AND METHODS: RecMNV was serially replicated in vitro in monolayers of RAW 264.7 cells over ten passages. Following a first initial infection at an MOI of 0.05, cell layers were consecutively infected with 100 μl neat supernatant of the preceding passage. Two independent lysis plaque assays were performed in triplicate with RecMNV progenies resulting from the first (early) and tenth (late) passage (RecE and RecL). Viral plaque sizes of RecE and RecL were measured with image processing program Image J and statistical analyses of plaque size diameters were subsequently performed. To obtain the complete genome sequences of RecE and RecL, a sequencing strategy was developed in which the MNV genome was divided into seven regions and amplification was performed using overlapping primers. Nucleotide sequences of RecE and RecL were analysed via BioEdit Sequence Editor. Growth curves of RecE and RecL progenies were established for high (10) or low MOI (0.01). RESULTS After ten in vitro passages, viral lysis plaque size diameters had increased significantly. Molecular analysis of RecMNV and both parental strains showed nine nucleotide mutations in the RecMNV genome, comprising three non-silent mutations. In addition, a mutation at position 7245 (A187G) introduced a stop codon, resulting in a 20 AA shorter VP2 in RecMNV (for both RecE and RecL). A comparison of RecE and RecL revealed four non-silent mutations in the NS1-2 and NS7 region of ORF1, two of which were present in the latter region (G1384D and S1393N). DISCUSSION This is the first study in which the fitness of a recombinant NoV strain was evaluated in vitro. Our data provides evidence of viral adaptation to a new environment (here a cell culture system) after a recombination event. Evidence of gain-of-function of RecMNV was demonstrated by differences in growth curves and viral lysis plaque size. In addition, non-silent mutations associated to the gain-of-function/in vitro adaptation were detected. It is noteworthy, that the mutation causing a shorter VP2 in RecE and RecL did not compromise its ability to infect and replicate either in vitro or in vivo (Mathijs et al, submitted). As a perspective we should like to characterise the precise mutation(s) responsible for the fitness regain via infectious clone assay. [less ▲]

Detailed reference viewed: 15 (4 ULg)
Peer Reviewed
See detailThe impact of cognitive reserve on recognition memory performance is dependent of the task format in healthy aging
Simon, Jessica ULg; Gilsoul, Jessica ULg; Bastin, Christine ULg

Poster (2016, March 17)

Objective: According to the cognitive reserve hypothesis (Stern, 2009), individuals who have developed a high level of reserve should resist better to the effects of aging than individuals with lower ... [more ▼]

Objective: According to the cognitive reserve hypothesis (Stern, 2009), individuals who have developed a high level of reserve should resist better to the effects of aging than individuals with lower cognitive reserve. In this study, we identified the factors of cognitive reserve that impact most memory performance in aging. Methods: 118 healthy older participants performed one yes/no recognition task and one 3-alternative forced-choice recognition task. For each recognized item, participants provided a Remember/Know/Guess judgment. Furthermore, participants completed a questionnaire assessing different aspects of cognitive reserve (level of education, occupation, physical, social, cultural and intellectual activities). We determined the moderators of cognitive reserve that explain a significant proportion of variance for each memory index through stepwise regression analyzes (p<0.05). Results: In the forced-choice test, the level of education explained positively the use of recollection and negatively the level of false alarms associated with familiarity. In the yes/no recognition task, the precision of recognition was explained positively by the physical activities. Recollection was positively explained by the physical activities and the level of education. Finally, the level of false alarms associated with familiarity was explained negatively by the level of education although the precision of the use of the familiarity is explained positively by physical activities. Conclusion: The more older adults were educated and/or were practicing physical activities, the better their recollection was. The impact of the moderators of the cognitive reserve is dependent on the format of the recognition task. [less ▲]

Detailed reference viewed: 42 (3 ULg)
Peer Reviewed
See detailEnhancing the salience of perceptual fluency improves familiarity-based recognition memory in aging
Bastin, Christine ULg; Willems, Sylvie ULg

Poster (2016, March 17)

Objective. Normal aging is characterized by decreased recollection, but better preserved familiarity. Memory tasks that facilitate the use of familiarity should allow attenuating age-related differences ... [more ▼]

Objective. Normal aging is characterized by decreased recollection, but better preserved familiarity. Memory tasks that facilitate the use of familiarity should allow attenuating age-related differences in memory. The study tested two hypotheses: (1) can the reliance on familiarity during recognition memory be promoted by increasing the difference in perceptual processing fluency between old and new items; (2) can this manipulation reduce age-related difficulties in episodic memory? Methods. Twenty-four young and 24 older adults performed two verbal recognition memory tasks. In the No-Overlap task, target words and new words did not share any letter. Prior exposition to the target words thus induced increased processing fluency of the words and letters, so that fluency difference was a salient and reliable cue to discriminate between old and new words. In the Overlap task, target and new words had letters in common, so fluency cues were less useful. Recollection and familiarity was assessed with the Remember/Know/Guess paradigm. Results. There was an age effect on recollection but intact familiarity. Moreover, (1) memory performance was better in the No Overlap than the Overlap task, with a greater hit rate and a smaller false alarm rate associated with familiarity. (2) Age-related differences in recognition accuracy (hits – false alarms) were significantly attenuated in the No Overlap task compared to the Overlap task. Conclusion. These findings suggest that minimizing the perceptual similarity between targets and distractors, and thus increasing processing fluency differences, allowed to reduce the effect of age on recognition memory performance by facilitating the use of familiarity. [less ▲]

Detailed reference viewed: 13 (2 ULg)
Full Text
See detailCharacterization of the impact of tillage and nitrogen fertilization on the root development of a winter wheat crop by use of NIR hyperspectral imaging combined to chemometrics
Fraipont, Guillaume ULg; Eylenbosch, Damien ULg; Fernández Pierna, Juan Antonio et al

Poster (2016, March 16)

The objective of this study is to characterize the impact of tillage management and nitrogen fertilization on the root system development of a winter wheat crop. To reach this objective, an innovative ... [more ▼]

The objective of this study is to characterize the impact of tillage management and nitrogen fertilization on the root system development of a winter wheat crop. To reach this objective, an innovative root quantification method that combines NIR hyperspectral imaging (NIR-HSI) and chemometric tools will be applied. [less ▲]

Detailed reference viewed: 42 (13 ULg)
Full Text
Peer Reviewed
See detailAgeism and communication in oncology
Schroyen, Sarah ULg; Adam, Stéphane ULg; Marquet, Manon ULg et al

Poster (2016, March 11)

Detailed reference viewed: 24 (4 ULg)