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See detailReduced Order Model for Accounting for High Frequency Effects in Power Electronic Components
Paquay, Yannick ULg; Geuzaine, Christophe ULg; Hasan, Md. Rokibul et al

Poster (2015, June)

This paper proposes a reduced-order model of power electronic components based on the proper orthogonal decomposition. Starting from a full-wave finite-element model and several snapshots/frequencies, the ... [more ▼]

This paper proposes a reduced-order model of power electronic components based on the proper orthogonal decomposition. Starting from a full-wave finite-element model and several snapshots/frequencies, the reduced-order (RO) model is constructed. Local field values (e.g. magnetic flux density, electric current density, magnetic or electric field) and global quantities (e.g. characteristic complex impedance, joule losses) can be determined for the intermediate frequencies with a very low computational cost and high accuracy. Particular attention is paid to the choice of the most suitable snapshots by means of three different greedy algorithms, the performance of which is compared. We adopt an automatic greedy algorithm that depends only on the RO model. [less ▲]

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See detailRemoval of antibiotic resistant bacteria in wastewater treatment plant
Bardiau, Marjorie ULg; Trajano, D; Taylor, H et al

Poster (2015, June)

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See detailFunctional analysis of FRD3 in Arabidopsis
Scheepers, Maxime ULg; Charlier, Jean-Benoit ULg; Spielmann, Julien ULg et al

Poster (2015, June)

Zinc and iron are two essential micronutrients for plants. The homeostasis networks of the two metals are intertwined. The FRD3 (FERRIC REDUCTASE DEFECTIVE 3) protein, a member of the MATE family of ... [more ▼]

Zinc and iron are two essential micronutrients for plants. The homeostasis networks of the two metals are intertwined. The FRD3 (FERRIC REDUCTASE DEFECTIVE 3) protein, a member of the MATE family of membrane transporters, is a citrate transporter involved in iron homeostasis and playing a role in zinc tolerance in Arabidopsis. The FRD3 gene displays a complex regulation. Alternative transcript initiation for FRD3 determines two transcripts, which differ in their 5'UTRs and have differential translation efficiency. The two transcripts are selectively regulated under stress conditions: iron and zinc depletion, zinc excess or cadmium presence. We are aiming to determine the FRD3 function in zinc and iron homeostasis in Arabidopsis. We will present data (i) on the functional characterization of the alternative transcripts and their role in metal homeostasis in Arabidopsis and (ii) on the zinc phenotypes of the frd3 mutant. [less ▲]

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See detailNonlinear Interpolation on Manifold of Reduced Order Models in Magnetodynamic Problems
Paquay, Yannick ULg; Bruls, Olivier ULg; Geuzaine, Christophe ULg

Poster (2015, June)

Proper Orthogonal Decomposition (POD) is an efficient model order reduction technique for linear problems in computational sciences, recently gaining popularity in electromagnetics. However, its ... [more ▼]

Proper Orthogonal Decomposition (POD) is an efficient model order reduction technique for linear problems in computational sciences, recently gaining popularity in electromagnetics. However, its efficiency has been shown to considerably degrade for nonlinear problems. In this paper, we propose a reduced order model for nonlinear magnetodynamic problems by combining POD with an interpolation on manifolds, which interpolates the reduced bases to efficiently construct the desired solution. [less ▲]

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See detailA web-based support system of the Belgian Register for Assisted Procreation
Gillain, Nicolas ULg; Bogaerts, Kris; Albert, Adelin ULg et al

Poster (2015, June)

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See detailDevelopment of a field test to evaluate colostrum quality (IgG) in cattle
Guyot, Hugues ULg; Dubreucq, Pierre ULg; Lebreton, Pascal et al

Poster (2015, June)

Failure of transfer of immunity from dam’s colostrum generates a negative effect on calves’ health leading to increased morbidity and mortality (De Nise et al., 1989; Wittum and Perino, 1995 ... [more ▼]

Failure of transfer of immunity from dam’s colostrum generates a negative effect on calves’ health leading to increased morbidity and mortality (De Nise et al., 1989; Wittum and Perino, 1995). Immunoglobulins (IgG) content of colostrum is highly variable and cannot be predicted. Distinguishing good from poor quality colostrum allows to adapt the volume administered or to initiate ancillary procedures for a sufficient transfer of IgG. The aim of the study was to evaluate the performances of a field test for colostrum quality determination. [less ▲]

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See detailDeciphering the metabolism of polyprenyl-phosphate: The universal glycan lipid carrier at the membrane frontier
Manat, Guillaume; Roure, Sophie; El Ghachi, Meriem ULg et al

Poster (2015, June)

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See detailEmpowering NGS technologies for the study and diagnostic of plant viruses - European COST Action FA1407
Massart, Sébastien ULg; Gentit, Pascal; Olmos, Antonio et al

Poster (2015, June)

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See detailThe neuroimaging meta-analysis database: A data-sharing initiative for neuroimaging meta-analyses
Reid, Andrew; Bzdok, Danilo; Genon, Sarah ULg et al

Poster (2015, June)

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See detailCharacteristics of Jupiter's auroral acceleration region
Ray, Licia; Gustin, Jacques ULg; Grodent, Denis ULg

Poster (2015, June)

Jupiter’s dynamic auroral region is the signature of magnetosphere-ionosphere coupling. The magnetospheric drivers of the emission are relatively well understood, yet the high-latitude characteristics of ... [more ▼]

Jupiter’s dynamic auroral region is the signature of magnetosphere-ionosphere coupling. The magnetospheric drivers of the emission are relatively well understood, yet the high-latitude characteristics of the interaction have not been measure in-situ. Ahead of Juno’s arrival next summer, we use HST STIS observations of Jupiter’s auroral emission to infer the location of Jupiter’s auroral acceleration region and the properties of the precipitating auroral electrons. We analyze two images of Jupiter’s northern emission, determining the precipitating electron energy and incident energy flux for the main aurora, Io spot, Ganymede footprint, and flare regions. The resulting relationships between energy flux and electron precipitation energy for the main auroral emission are compared to the theoretical relationship derived by Lundin & Sandahl [1978] for a range of auroral region locations, and temperatures and densities appropriate for the jovian system. [less ▲]

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See detailExtracellular peptidase hunting for improvement of protein production in plant cells and roots
Lallemand, Jérôme ULg; Bouché, Frédéric ULg; Desiron, Carole et al

Poster (2015, June)

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, proteolysis being one of the main factors limiting the yields. Identifying and inhibiting in vivo endogenous proteases involved in the degradation of recombinant proteins could then lead to a significant increase in production yields. In this study, we focused on two different production systems in Arabidopsis thaliana: rhizosecretion and cell suspensions. Extracellular proteases of both systems were used in vitro to study the conditions of target protein degradation (Bovine Serum Albumine, BSA). First, proteases from both systems degrade BSA at both acidic and neutral-to-basic pH conditions. Then, serine and metallopeptidases were shown to be the main protease classes responsible for BSA degradation by rhizosecreted proteomes or extracellular cell culture media, respectively. Finally, the biochemical tests were coupled to a bioinformatics analysis of publicly available transcriptomic data, in order to reduce the number of the proteases most likely involved in BSA degradation. Using this method, only five serine proteases and two metallopeptidases remain candidates for an amiRNA-mediated in vivo inhibition. [less ▲]

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See detailUnravelling Cemip expression and functions in the auditory portion of the inner ear.
Czajkowski, Amandine ULg; Chariot, Alain ULg; Delacroix, Laurence ULg et al

Poster (2015, May 29)

The inner ear is a complex organ composed of the vestibular system – which is the balancing system – and the cochlea – which is the earing system. The cochlea is a coiled shape organ composed of three ... [more ▼]

The inner ear is a complex organ composed of the vestibular system – which is the balancing system – and the cochlea – which is the earing system. The cochlea is a coiled shape organ composed of three main structures: the spiral ligament sitting on top of the stria vascularis, the organ of Corti with sensory hair cells and supporting cells and the spiral ganglion composed of neurons and glial cells. After an auditory stimulus, the sound wave progresses in the scala media filled with endolymph and induces a stimulation of sensory hair cells. These cells then transmit the information to the spiral ganglion neurons connected to them. Of course, the correct ionic homeostasis of endolymph is required for a good sound wave transmission. This homeostatic function is assured by the stria vascularis and the spiral ligament. The alteration of one of the structures mentioned before induces deafness. Currently, numerous genes have been associated to this kind of hearing loss. In the present work, we focus our attention Cemip – also known as KIAA1199 – that has been associated to human hereditary neurosensory deafness. Indeed, three missense mutations consisting in non-synonymous amino acid changes (R187L, R187H and H783Y) have been associated to this form of deafness. Therefore we would like to understand the role of Cemip in the cochlea. For that we have analysed Cemip mRNA pattern of expression by in situ hybridization at different developmental stages on cochlear sections. It seems Cemip mRNA is not present in the auditory portion of the inner ear at early embryonic stage 14 (E14) while it is largely present at E17 in the spiral ganglion, in supporting cells of the organ of Corti and in the spiral ligament. This expression is maintained post-nattily until P7. At P21 the expression is restricted to the spiral lamina - an osseous structure surrounding the spiral ganglion. Our on going work is aimed at revealing the biological role of Cemip in the cochlea in conditional knock-out mice. [less ▲]

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See detailExecutive functions in normal aging: Impact of cognitive reserve and objective physical activity
Gilsoul, Jessica ULg; Simon, Jessica ULg; Collette, Fabienne ULg

Poster (2015, May 28)

It is now acknowledged that there exists a large inter-individual variability in age-related cognitive changes. According to Stern (2009), the cognitive reserve built up throughout the life span will make ... [more ▼]

It is now acknowledged that there exists a large inter-individual variability in age-related cognitive changes. According to Stern (2009), the cognitive reserve built up throughout the life span will make seniors more or less resilient to the deleterious effects of aging on cognition, with seniors having a high level of cognitive reserve being more prone to successfully cope with cognitive and neuronal changes. Currently, few studies have focused on the specific effects of different factors of cognitive reserve on cognition. Consequently, the objective of this study is to determine the impact of four determinants of cognitive reserve on executive functions in normal aging. Sixty-eight healthy participants aged 60 to 80 were enrolled. Regarding executive functions, Inhibition (Stroop test, Hayling test, TAP Incompatibility subtest), Shifting (TAP Flexibility subtest, Plus-Minus task), and Updating (Letter-Number Sequencing subtest from MEM III, Letter memory task, 2-back task) were assessed (Miyake et al., 2000). Cognitive reserve was measured by questionnaires assessing educational level, occupation, leisure activities and physical activity. Moreover, an accelerometer allowed quantitative measure of physical activity by recording body movements during two weeks. Group comparisons (p<0.05) showed that seniors with a high level of cognitive reserve (measured by a global composite z-score) have better updating abilities (Letter memory task and updating composite score). In order to test the influence of each cognitive reserve factor on executive functions, simple linear regressions (p<0.05) were performed. The results showed that the educational level accounts for a significant part of the variance in flexibility (TAP Flexibility) and updating (Letter-Number sequencing, 2-back and composite score). The occupational level accounts significantly for the variance of the updating composite score. Regarding the quantitative physical activity, the mean number of minutes per day in moderate or intense physical activity significantly predicted the updating composite score. These results indicate that the level of cognitive reserve is related to abilities in some executive tests, particularly updating abilities. Importantly, all aspects of cognitive reserve are not associated with the three executive processes. This indicates a specificity of the protective effect of cognitive reserve on executive abilities. [less ▲]

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See detailWork incapacity and chronic pain patients: Is there an impact of work incapacity on anxiety and depression?
Beaumel, Alexia; Vanootighem, Valentine ULg; Gillet, Aline ULg et al

Poster (2015, May 28)

In 2011, a report of the Federal Public Service have shown that 8.5% of the Belgian population suffers from chronic pains, which represents 938 300 belgian people (Berquin et al., 2011). These persistent ... [more ▼]

In 2011, a report of the Federal Public Service have shown that 8.5% of the Belgian population suffers from chronic pains, which represents 938 300 belgian people (Berquin et al., 2011). These persistent pains may result in functional limitations on both domestic and professional domains which may lead to temporary or permanently work incapacity (Faymonville et al., 2014). These incapacities may in turn cause a social withdrawal and a tendency to focus on pain (Berquin et al., 2011). Additionally, patients are prone to emotional modifications due to persistent pain (Ossipov et al., 2010). All of these factors may contribute in the emergence of anxiety and depressive symptoms. The present study examines the impact of type of work incapacities (at work, temporary incapacity and permanent incapacity) on anxiety and depression scores as a function of diagnoses (fibromyalgia, chronic pain syndrome, back pain, polyalgia). 123 patients suffering from chronic pain completed a measure of anxiety and depression (HADS), and a self-reported questionnaire of psychological and physical disability at work. We did not found any significant effect of type of work incapacities on anxiety and depression scores. Results present tables of frequencies to illustrate the social and professional situations of patients as a function of chronic pain diagnoses. [less ▲]

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See detailThe neural bases of proactive and reactive control processes in healthy aging
Manard, Marine ULg; François, Sarah ULg; SALMON, Eric ULg et al

Poster (2015, May 28)

Background. Research on cognitive control suggests an age-related decline in proactive control abilities (an anticipatory form of control) whereas reactive control (consecutive to conflict detection ... [more ▼]

Background. Research on cognitive control suggests an age-related decline in proactive control abilities (an anticipatory form of control) whereas reactive control (consecutive to conflict detection) seems to remain intact [1]. As proactive and reactive control abilities were associated to specific brain networks [2], this study investigated age-related effects on the neural substrates associated to each kind of control. Method. A modified form of the Stroop task was administered to 16 young and 16 older adults in an event-related fMRI experiment. In this version of the Stroop task, three different contexts were created: (1) a mostly congruent context (MC, inducing reactive control) with a majority of congruent items, (2) a mostly incongruent context (MI, inducing proactive control) with mainly interfering items, (3) a neutral context (MN) with mainly neutral items. Preprocessing and statistical analyses were performed with SPM8 (p<.001 uncorrected). Results. Behavioral results (p<0.05) indicated faster processing of interferent items in the MI than MC context in young participants only. With regard to neuroimaging data, the comparison of the two groups showed that the processing of interferent items in the MI context is associated to decreased activity in (mainly right-sided) frontal and temporal areas in the older group. On the contrary, in the MC context, increased activity was observed in bilateral frontal areas for older compared to younger participants. Discussion. Behavioral results confirm that older participants have difficulties with the implementation of proactive control that is associated to decreased brain activity (compared to young participants) in areas underlying Stroop performance. However, the recruitment of supplementary frontal areas we observed in the reactive control condition suggests compensation processes. So, aging seems to differentially affect the neural networks associated to the various kinds of cognitive control. [less ▲]

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See detailPsychopathy and emotions: would emotional distancing make more efficient in cognitive tasks?
Grandjean, Sylvie; Dehon, Hedwige ULg; Blavier, Adelaïde ULg et al

Poster (2015, May 28)

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See detailMaternal representations, social context and substance abuse
Halin, Stéphanie ULg; Combe, Samantha; Glowacz, Fabienne ULg et al

Poster (2015, May 28)

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See detailBorderline Personality Disorder through the Rorschach test
Rommes, Jennifer; Englebert, Jérôme ULg; Blavier, Adelaïde ULg

Poster (2015, May 28)

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See detailParental and romantic attachments in teen datings : different meanings in boys' and girls' intimacy
Courtain, Audrey ULg; Lepas, Jennifer; Boulard, Aurore ULg et al

Poster (2015, May 28)

First proposing a relational understanding of the child’s very first years, attachment theory has since then been taken into consideration in friendships and romantic relationships. Indeed, the internal ... [more ▼]

First proposing a relational understanding of the child’s very first years, attachment theory has since then been taken into consideration in friendships and romantic relationships. Indeed, the internal working models (IWM) built upon early interactions are to be used on and on in many other situations as guidelines to understand what is going on for the self, this particular other and their specific relationship. Different attachment styles are thus likely to develop: secure or insecure (anxious/preoccupied, avoidant/dismissive, fearful). Considering teen dating, attachment is deeply involved, especially for two reasons: first, a certain questioning, but also re-actualization, of the attachment to parents; second, a new kind of attachment, meaning the one to the romantic partner. These elements lead us to test hypotheses linking attachment to parents and attachment to romantic partners, but also linking these attachments to some teen dating characteristics, such as the age when first dating, the number of love relationships, the longest-lasting love relationship and the fear of intimacy. Our hypothesis was tested among 283 teenagers (mean age = 17.43) with two self-administered questionnaires (the Behavioral Systems Questionnaire and the Fear of Intimacy Scale). Our statistical analyses were made of Pearson Chi², Anova and Post-Hoc Fisher (LSD). We see three types of interesting results. First, there is a significant relationship between attachment (parental and romantic attachments) and the number of love relationships and the fear of intimacy. Second, these relationships are differently established once considered the attachment modalities. Third, gender differences appear, girls looking more influenced by their attachment style than boys. [less ▲]

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See detailRomantic relationship and delinquency : which desistance factor ?
Puglia, Rosa ULg; Lepas, Jennifer; Glowacz, Fabienne ULg

Poster (2015, May 28)

A large number of studies (Stouthamer-Loeber, Loeber, Wei, Farrington & Wikstrom, 2002) have shown that the quality of parent-child relationship influences delinquency behavior during adolescence. So, the ... [more ▼]

A large number of studies (Stouthamer-Loeber, Loeber, Wei, Farrington & Wikstrom, 2002) have shown that the quality of parent-child relationship influences delinquency behavior during adolescence. So, the poorer the quality of relationship between a parent and his child is, the higher the probability that the child adopts delinquent behavior. However, recent studies (Giordano et al., 2002 ; Laub et al., 1998 ; Meeus & al., 2004 ; Woordward et al., 2002) have questioned the persistence of this association when people involved in a romantic relationship. These research have shown that quality of parent-child relationship predict delinquency in adolescents and young adults who do not have an intimate partner. But in adolescents and young adults who have an intimate partner, quality of parent-child relationship becomes obsolete. To be involved in an intimate relationship leads to less delinquency. Furthermore, results are concordant with research about desistance from delinquency that have shown that marriage leads to less criminality (Forrest & Hay, 2011 ; Sampson & Laub, 1993). These studies (Meus & al., 2004 ; Sampson & Laub, 1993) specify that it is quality of relationship rather than simply being in a romantic relationship that have an impact on desistance from delinquency. From empirical research conducted with adolescents and young adults (N=283) aged from 16 to 22 years old, and from a clinical research, we have explored links between parental attachment, romantic attachment and delinquency. We wondered if romantic attachment promotes desistance from delinquency whatever parental attachment. Behavioral System Questionnaire (Wehner & Furman, 1999) and self-reported delinquency scale (Born & Gavray, 1994) have used in this context. It appears that most of the participants have been involved in a significant romantic relationship. This romantic relationship is mainly characterized by a secure attachment. So, it leads to less deviant behaviors. On the other hand, parental attachment does not lead to less deviant behaviors. It also appears that attachment style that one develops towards one’s parent is not unchangeable. Romantic relationship during adolescence and adulthood can bring emotional and relational modifications. [less ▲]

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See detailThe impact of ageing on episodic memory encoding: an fMRI study
François, Sarah ULg; Angel, Lucie; Salmon, Eric ULg et al

Poster (2015, May 28)

It is now commonly accepted that a decline in episodic memory is observed with ageing: while recollection processes are impaired, familiarity seems to be relatively preserved (a). Older individuals appear ... [more ▼]

It is now commonly accepted that a decline in episodic memory is observed with ageing: while recollection processes are impaired, familiarity seems to be relatively preserved (a). Older individuals appear to recruit prefrontal areas bilaterally when their encoding is successful, while in young adults this activation is found to be left-lateralized (b). In this study, we were interested in the differences between younger and older participant regarding cerebral activity during encoding depending on whether the item elicited recollection or familiarity during the recognition phase. Twenty young volunteers (aged 19 to 29 years old) and 19 older volunteers (aged 60 to 78 years old) were presented visual stimuli depicting objects. During a first fMRI session, they were asked to make a size judgement about them. Then, in a second phase, the subjects were shown the items previously encountered during the encoding phase, as well as distractors. Participants' task was to determine which one were new and which one were seen earlier. For the latter, they also performed a Remember-Know judgement. Data were analysed using SPM8, with an event design comparing modifications in cerebral activity between the two subjects groups during encoding (1) for the items leading to recollection during the recognition phase compared to those leading to familiarity, and (2) for the items associated with familiarity during the recognition phase compared to those which were not recognized. Results show that older adults display a heightened activity in the right middle frontal gyrus, medial cingulate and paracingulate left gyri as well as in the precuneus, bilaterally when they engage recollection processes. Given that activations in these areas did not correlate with performance, they could be interepreted either as dedifferentiation or as an attempt of the ageing brain to compensate for a less elaborate encoding. However, no increase of activity was associated with familiarity processes in older adults, possibly because they are less demanding regarding attentional resources. (a) Bugaiska, A., Clarys, D., Jarry, C., Taconnat, L., Tapia, G., Vanneste, S., & Isingrini, M. (2007). The effect of aging in recollective experience: the processing speed and executive functioning hypothesis. Consciousness and Cognition, 16(4), 797-808. doi: 10.1016/j.concog.2006.11.007 (b) Duverne, S., Motamedinia, S., & Rugg, M. D. (2009). The relationship between aging, performance, and the neural correlates of successful memory encoding. Cerebral Cortex, 19(3), 733-744. doi:10.1093/cercor/bhn122 [less ▲]

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See detailThe effect of ageing and encoding instructions on episodic memory
Hagelstein, Catherine ULg; François, Sarah ULg; Manard, Marine ULg et al

Poster (2015, May 28)

During ageing, a decline in episodic memory is observed, characterized by decreased recollection (a). In this study, we investigated the influence of encoding instructions, intentional or incidental, on ... [more ▼]

During ageing, a decline in episodic memory is observed, characterized by decreased recollection (a). In this study, we investigated the influence of encoding instructions, intentional or incidental, on the performance of younger and older adults during an episodic memory task. Twenty young volunteers (aged 18 to 30 years old) and 20 older volunteers (aged 61 to 72 years old) participated in this experiment. The stimuli consisted of 300 black-and-white drawings of common objects. The task comprised two steps. During the encoding phase, 100 items were presented once ("hard" condition) and 100 other items were presented twice ("easy" condition). During recognition, the items from the encoding phase were presented again, as well as 100 new items. In each age group, half of the participants received incidental encoding instructions (they had to make size judgements about the objects depicted) while the other half were explicitly asked to memorize the objects presented because they would be asked to recognize them later on (intentional encoding). During recognition, they performed a Remember-Know judgement for the items they believed they had seen earlier. We carried out ANOVAs in order to test for the influence of instructions, age group and number of repetitions of the items in one hand on the percentage of recollection and on the other hand on the percentage of familiarity (p<.05). Results show a significant effect of age, with more correct recollection responses in young adults, whereas more correct familiarity was found in older adults. Furthermore, it was found that the items presented twice lead to more recollection than those presented only once. Finally, these results also suggest that in the older group of participants, only for the items presented twice, intentional encoding instructions lead to more recollection and less familiarity. This finding is consistent with previous work showing that the elderly do not easily use elaborate encoding strategies, and that they need more support (here, a second exposition to the material) in order to perform a deep encoding when they are encouraged to do so with intentional learning instructions (b). (a) Bugaiska, A., Clarys, D., Jarry, C., Taconnat, L., Tapia, G., Vanneste, S., & Isingrini, M. (2007). The effect of aging in recollective experience: the processing speed and executive functioning hypothesis. Consciousness and Cognition, 16(4), 797-808. doi: 10.1016/j.concog.2006.11.007 (b) Froger, C., Bouazzaoui, B., Isingrini, M., & Taconnat, L. (2012). Study time allocation deficit of older adults: the role of environmental support at encoding? Psychology and Aging, 27(3), 577-588. doi:10.1037/a0026358 [less ▲]

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See detailContributing to wood anatomical databases to improve species identification, phylogeny and functional trait research in Central Africa
Morin, Julie ULg; Fayolle, Adeline ULg; De Ridder, Maaike et al

Poster (2015, May 26)

Central African rainforests shelter a high number of woody species that are anatomically very different. Knowledge of taxon-specific wood anatomical features has proven indispensable for scientific and ... [more ▼]

Central African rainforests shelter a high number of woody species that are anatomically very different. Knowledge of taxon-specific wood anatomical features has proven indispensable for scientific and non-scientific applications. The field of wood anatomy and identification has been drastically revolutionized by the development of internationally recognized lists of precisely illustrated microscopic features (e.g. IAWA Committee 1989), together with the launch of InsideWood, an online search database using these features to narrow down identification results (e.g. Wheeler 2011). However, despite these massive efforts, the anatomy of many species or even genera remains in the dark, especially in species-rich regions. Wood anatomy has been formally described for less than 25% of the Central African woody species (Hubau et al. 2012), the focus has been mainly on timber species and variations in wood anatomical structure remain to be explored. Therefore, we are assembling a wood anatomical database of about 800 species covering the Guineo-Congolian region using material from InsideWood and the Tervuren xylarium (new descriptions). As such, we present how large anatomical databases hold interesting perspectives for (i) wood and charcoal identification, (ii) exploring the phylogenetic signal of wood anatomy, and (iii) the relationship between wood anatomical features and functional traits. [less ▲]

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See detailElectron paramagnetic resonance and fluorescence studies on potential anticancer properties of two new Ru(II) complexes : preliminary results
Collienne, Simon ULg; Terrak, Mohammed ULg; Mouithys-Mickalad, Ange ULg et al

Poster (2015, May 22)

Fight against cancer is a priority of today’s research. Since the discovery of the anticancer properties of cisplatin (CisPt) in 1965 by Rosenberg [1], the treatment of cancer by chemotherapy has known ... [more ▼]

Fight against cancer is a priority of today’s research. Since the discovery of the anticancer properties of cisplatin (CisPt) in 1965 by Rosenberg [1], the treatment of cancer by chemotherapy has known great improvements. Unfortunately, CisPt has several side effects and is not effective against all kinds of cancer. Nevertheless its use highlights the great potential of organometallic compounds in the treatment of cancer [2]. Here we investigated the potential anticancer properties of two new organometallic compounds based on ruthenium II : [RuCl(p-cymene)(S2C.IDip)]+(PF6)- and [RuCl(p-cymene)(S2C.ICy)]+(PF6)-, named as LDO436 and LDO437 respectively. [less ▲]

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See detailGene-based replication strategy and meta-analysis in the context of epistasis: application for Alzheimer’s disease.
Gusareva, Elena ULg; van der Lee, Sven; Katsumata, Yuriko et al

Poster (2015, May 22)

Although the discovery of biological epistasis via statistical methods remains a big challenge, large-scale epistasis studies have become more and more popular nowadays. Considering the power of genome ... [more ▼]

Although the discovery of biological epistasis via statistical methods remains a big challenge, large-scale epistasis studies have become more and more popular nowadays. Considering the power of genome-wide association interaction analysis (GWAI) is conceptually lower when comparing to GWA using the same data, the genome-wide screenings for epistasis often ends with no statistically significant findings. Therefore, sound meta-analytic methodologies for combining evidence across independent gene-gene interaction studies, taking into account characteristics of individual studies, as well as protocols for good standard practice of meta-GWAI analysis are missing so far. The existing methodologies, whereas is suboptimal, may still be the first choice in meta-GWAI. In our study, the genome-wide significant interaction between two var¬¬iants of WWC1 and TLN2 genes were first discovered in males of EADI1 of Alzheimer’s disease (AD) case/control cohort. Adopting the gene-based replication approach recently advocated by Gusareva and Van Steen (Hum Genet 2014), we assessed association between all available variants from the pair of genes to test for pair-wise interactions in three independent AD replication cohorts (GERAD1, AD cohort from Rotterdam study - RS, and ADGC). Particularly, we used regression modeling with co-dominant coding of genetic markers (the one that was found to be the most powerful to identify epistasis and gives the least false positive results) and taking into account possible confounding factors (age and the first four PCs). We further meta-analyzed p-values for the interaction effects across all pairs of markers in males and females using Fisher summary test statistic. For the most interesting epistasis signal that occur in males of EADI1 cohort and two replication cohorts (RS and ADGC), we also conducted multi-locus genotype (MLG) association analysis (quantifies effects sizes of each of eight multilocus genotypes derived from the SNPs-pair versus the reference category - homozygous for the major alleles) and then met-analyzed results using the random effect or fixed effect models depending on presence of heterogeneity between studies. Adopting this approach we statistically replicated the interaction between WWC1 and TLN2 genes. Although, the biological validation of this finding is still ahead, we can already demonstrate effectiveness of the adopted meta-analysis pipeline to identify novel genetic factors potentially predisposing to AD. [less ▲]

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See detail"Tell me about Self." Clarté de soi et souvenirs définissant le soi: Particularités du self chez des individus souffrant d'un trouble de l'humeur
Boulanger, Marie ULg; Wagener, Aurélie ULg; Blairy, Sylvie ULg

Poster (2015, May 21)

The present study focusses on a particular kind of autobiographical memories called self-defining memories (SDMs). SDMs are highly pertinent for self-building because they help to define in the most ... [more ▼]

The present study focusses on a particular kind of autobiographical memories called self-defining memories (SDMs). SDMs are highly pertinent for self-building because they help to define in the most clearly way our perception of ourselves. If literature showed that depressed and bipolar patients suffer from autobiographical memory (AM) disturbances, SDMs have not been studied a lot since yet in these two disorders. Then, the present study pursues two main aims: (1) to assess SDM’s characteristics and (2) to assess the relationship between the ability to retrieve SDM’s and self-concept clarity. To reach our objective, 17 depressed and 16 bipolar patients are compared to 17 healthy subjects. Participants are asked to complete SDMs procedure that is recalling six important events which happened in their life. These SDMs are assessed on four variables: specificity, impact, valence, meaning making, contain. Self-concept clarity and mood are also assessed. Preliminary results do not highlight difference between our groups on specificity. Marginal effects appear for meaning making with healthy subjects recalling more meaning making events. Results show that depressed patients present a mood congruence. The final results will be presented during the convention, as data-collection is on-going and will end in April. Experimental and clinical implications of our results will be discussed. [less ▲]

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See detailThe impact of ageing on episodic memory encoding: an fMRI study
François, Sarah ULg; Angel, Lucie; Salmon, Eric ULg et al

Poster (2015, May 21)

It is now commonly accepted that a decline in episodic memory is observed with ageing: while recollection processes are impaired, familiarity seems to be relatively preserved (a). Older individuals appear ... [more ▼]

It is now commonly accepted that a decline in episodic memory is observed with ageing: while recollection processes are impaired, familiarity seems to be relatively preserved (a). Older individuals appear to recruit prefrontal areas bilaterally when their encoding is successful, while in young adults this activation is found to be left-lateralized (b). In this study, we were interested in the differences between younger and older participant regarding cerebral activity during encoding depending on whether the item elicited recollection or familiarity during the recognition phase. Twenty young volunteers (aged 19 to 29 years old) and 19 older volunteers (aged 60 to 78 years old) were presented visual stimuli depicting objects. During a first fMRI session, they were asked to make a size judgement about them. Then, in a second phase, the subjects were shown the items previously encountered during the encoding phase, as well as distractors. Participants' task was to determine which one were new and which one were seen earlier. For the latter, they also performed a Remember-Know judgement. Data were analysed using SPM8, with an event design comparing modifications in cerebral activity between the two subjects groups during encoding (1) for the items leading to recollection during the recognition phase compared to those leading to familiarity, and (2) for the items associated with familiarity during the recognition phase compared to those which were not recognized. Results show that older adults display a heightened activity in the right middle frontal gyrus, medial cingulate and paracingulate left gyri as well as in the precuneus, bilaterally when they engage recollection processes. Amongst those regions, the precuneus seems to underlie compensatory processes, allowing the elderly to perform a richer encoding, as it was previously suggested for recollection processes during recall (c). However, no increase in activity was associated with familiarity processes in older adults, possibly because they are less demanding regarding attentional resources. (a) Bugaiska, A., Clarys, D., Jarry, C., Taconnat, L., Tapia, G., Vanneste, S., & Isingrini, M. (2007). The effect of aging in recollective experience: the processing speed and executive functioning hypothesis. Consciousness and Cognition, 16(4), 797-808. doi: 10.1016/j.concog.2006.11.007 (b) Duverne, S., Motamedinia, S., & Rugg, M. D. (2009). The relationship between aging, performance, and the neural correlates of successful memory encoding. Cerebral Cortex, 19(3), 733-744. doi:10.1093/cercor/bhn122 (c) Angel, L., Bastin, C., Genon, S., Balteau, E., Phillips, C., Luxen, A., . . . Collette, F. (2013). Differential effects of aging on the neural correlates of recollection and familiarity. Cortex, 49(6), 1585-1597. doi:10.1016/j.cortex.2012.10.002 [less ▲]

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See detailAgroecology: Unity into diversity
Hatt, Séverin ULg; Artru, Sidonie ULg; Boeraeve, Fanny ULg et al

Poster (2015, May 21)

What does agroecology suggest ? Next to the theoretical agroecological principles, we present illustrative examples from farming practices, through the food system, up to the way of carrying agricultural ... [more ▼]

What does agroecology suggest ? Next to the theoretical agroecological principles, we present illustrative examples from farming practices, through the food system, up to the way of carrying agricultural research and education. [less ▲]

Detailed reference viewed: 72 (12 ULg)
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See detailMaladaptive emotion regulation strategies and stress sensitivity mediate the relation between adverse life events and attenuated psychotic symptoms.
Laloyaux, Julien ULg; Dessart, Gregory; Van der Linden, Martial ULg et al

Poster (2015, May 21)

Introduction There is now solid evidence for a relation between Adverse Life Events (ALE) and psychotic symptoms in both patients with psychosis and in the general population. A recent study has shown ... [more ▼]

Introduction There is now solid evidence for a relation between Adverse Life Events (ALE) and psychotic symptoms in both patients with psychosis and in the general population. A recent study has shown that this relation may be partially mediated by stress sensitivity. However, other factors that may mediate this relation, such as emotion regulation strategies, have not yet been examined in the literature. Objective The aim of this study was to assess the mediation effect of both emotion regulation strategies and stress sensitivity in the relation between ALE and attenuated positive psychotic symptoms in the general population. Results Results demonstrated that the relation between ALE and attenuated positive psychotic symptoms (i.e. hallucinations and delusions) was mediated by maladaptive emotion regulations strategies. Discussion Although it is most likely that there are several possible trajectories leading to the formation of positive psychotic symptoms, the results of the present study suggest that one such trajectory may involve the maladaptive regulation of negative emotions alongside a certain vulnerability after experiencing highly distressing ALE. Hence, interventions aiming to enhance adaptive emotion regulation strategies and diminish the utilization of maladaptive strategies should be regarded as an integral part of psychological treatment schemes in the context of psychotic symptoms. Conclusion In summary, the present study demonstrated that the relation between ALE and attenuated positive psychotic symptoms is mediated by maladaptive emotion regulation strategies. [less ▲]

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See detailCopperflora – an online species-level database of biology, ecology, geography of the flora from the Katangan Copperbelt (D.R. Congo) to manage their conservation
Boisson, Sylvain ULg; Seleck, Maxime ULg; Le Stradic, Soizig ULg et al

Poster (2015, May 21)

Storage and accessibility to structured data are essential in all fields of scientific research. In ecology, conservation managers regularly use thousands qualitative and quantitative data from different ... [more ▼]

Storage and accessibility to structured data are essential in all fields of scientific research. In ecology, conservation managers regularly use thousands qualitative and quantitative data from different partners and studies. In recent years, online databases concerning climate, species traits and distribution have been developed but few offer a comprehensive tool for the management of species conservation at several steps. The Copperflora database was created in order to include a diversity of informations about species (taxonomy, habitats, phenology, pictures, distribution, etc.) but also information concerning seeds collection, conservation, monitoring and tests applied to target species. Copperflora is meant to be an interactive and a dynamic project enhancing the exchange of data. Our project also contributes to the advance in the understanding of metallophyte communities’ conservation and restoration projects. Our database structure is expected to be easily transferable to other conservation actions. [less ▲]

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See detailCARRIAGE OF CLOSTRIDIUM DIFFICILE IN HOSPITAL PATIENTS IN SPAIN, INCLUDING MOLECULAR CHARACTERIZATION AND ANTIMICROBIAL SUSCEPTIBILITY OF THE ISOLATES
Rodriguez Diaz, Cristina ULg; Taminiau, Bernard ULg; Van Broeck, Johan et al

Poster (2015, May 21)

Increasing age, several co-morbidities, environmental contamination, antibiotic exposure and other intestinal perturbations appear to be the greatest risk factors for C. difficile infection (CDI ... [more ▼]

Increasing age, several co-morbidities, environmental contamination, antibiotic exposure and other intestinal perturbations appear to be the greatest risk factors for C. difficile infection (CDI). Therefore, hospitalized patients are considered particularly vulnerable to CDI. The main objective of this study was to evaluate the prevalence of C. difficile in a Spanish hospital and to characterize the isolates with respect to the PCR-ribotype, antibiotic resistance and toxin activity. In addition, multilocus sequence typing (MLST) was performed in order to study clonal relationships between C. difficile isolates obtained from two different countries. Culture of samples was performed in a selective medium cycloserine cefoxitin fructose cholate. An identification of the isolated colonies was done by PCR detection of tpi, tcdA, tcdB and cdtA genes. Toxic activity was confirmed by a cytotoxic immunoassay. Further characterization was performed by PCR ribotyping. MLST was used in order to determine genetic relationships between Spanish and Belgian C. difficile isolates recovered from hospital patients in both countries. C. difficile was frequently detected in hospitalized patients. The isolates belonged to different PCR ribotypes, including type 027. Most of the strains obtained harboured tcdA and tcdB genes. The number of positive faecal samples considerably increased among elderly patients over 65 years old. The multi-locus sequence typing (MLST) analysis showed that some Spanish and Belgian isolates cluster in the same lineage. This study reveals the circulation of toxigenic C. difficile in a Spanish hospital. The relatedness between Belgian and Spanish isolates indicate a common source or a lack of diversity from some PCR-ribotypes. Moreover, data obtained suggest that the combination of ribotyping and MLST is a good tool for the inter-laboratory comparison of strains among different countries. Continuous inter-country surveillance is suitable to understand the spread of C. difficile isolates among hospitalized patients. [less ▲]

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See detailCombining remote sensing and ancillary data to improve species distribution models
Delangre, Jessica ULg; Radoux, Julien; Jacquemin, Floriane ULg et al

Poster (2015, May 21)

Correlative distribution models are increasingly used in biological conservation. They often require the compilation of various environmental attributes (climate, topography, land cover,…), which can be ... [more ▼]

Correlative distribution models are increasingly used in biological conservation. They often require the compilation of various environmental attributes (climate, topography, land cover,…), which can be very time-consuming. In the Lifewatch project, a database combining segmentation in homogeneous landscape units (“ecotopes”) and environmental attributes derived from regularly updated remote sensing data (land cover, potential solar energy,…) and other data sources (climate, topography,…) has been designed. Our aim was to assess the usefulness of this database for species distribution modelling and to propose further improvements. The distribution of ten species (four butterflies, three birds, two reptiles and one mammal) was modelled across Wallonia and model performance was assessed by Area Under the ROC Curve using the subsample approach. The models derived from ecotope segmentation and quantitative land cover attributes were compared to those obtained with a corresponding grid and a qualitative land cover database. The usefulness of ancillary data (soil properties, contextual attributes) was assessed to decide which variables should be integrated in the ecotope database. The results allowed us to assess and improve the relevance and accuracy of our database, which is a promising tool for species distribution modellers at the European scale. [less ▲]

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See detailStudy of essential oil activity on Curvularia sp. a rice leaf spot pathogen in Madagascar
Mamiharisoa Razanakoto, Léa ULg; Parisi, Olivier ULg; Massart, Sébastien ULg et al

Poster (2015, May 19)

Rice leaf spot have been observed on many fields during survey of rice diseases in three regions in Madagascar. Curvularia sp. was the most frequently isolated pathogen from the most severe diseased ... [more ▼]

Rice leaf spot have been observed on many fields during survey of rice diseases in three regions in Madagascar. Curvularia sp. was the most frequently isolated pathogen from the most severe diseased samples. This pathogen has been reported worldwide to cause important losses. Then in this work, we study the possibility to develop an alternative method to control Curvularia sp. Plants or plant extracts have been traditionally used to control human and plant diseases. Nowadays, the problem of residues of phytopharmaceutical products, reinforce the need for research on the development of natural plant extracts to control plant diseases. Madagascar has many endemic plants of interest. The antimicrobial properties of essential oils from Malagasy aromatic plants were evaluated. The main steps of this study are (i) the in-vitro screening of 39 Malagasy essential oils to control this pathogen, (ii) the evaluation of the phytotoxicity (on rice plants) of the efficient essential oils and (iii) the in vivo test of the activity of these non phytotoxic essential oils on Curvularia sp. on rice seedlings. The activity of essentials oils on Curvularia sp. has been tested in vitro during a microscale ELISA plate bioassay using optical density for a rapid evaluation of the biofungicidal activity of the extracts. Essential oils that showed interesting antifungal effect on this pathogen were tested for their phytotoxicity on rice plants. Briefly, one to two drop(s) of essential oils were applied on 3 leaves leaves of three weeks rice seedling. Six essential oils over the 39 tested showed an interesting antifungal activity with a percentage of growth inhibition greater than 70%. Three essential oils tested were phytotoxic as they induced necrotic spots on rice leaves after 48 h. Among three essential oils left, one of them showed an important effect when applied on rice seedling inoculated with a conidial suspension of Curvularia sp. These results confirmed that some essential oils present an antifungal activity. And even some of them are phytotoxic on rice plants, some essential oils show interesting potential to be an alternative method against rice diseases. [less ▲]

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See detailToxicity of several fungicides for orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae)
Chavalle, Sandrine ULg; Jansen, Jean-Pierre; San Martin y Gomez, Gilles et al

Poster (2015, May 19)

The orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), can cause severe losses in wheat grain yield and quality. This pest is known to be susceptible to many insecticides ... [more ▼]

The orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), can cause severe losses in wheat grain yield and quality. This pest is known to be susceptible to many insecticides, but various field observations have suggested that some fungicides could also significantly affect S. mosellana. In order to confirm these field observations, the effect on adult midges of several fungicides commonly applied to wheat crops was investigated in the laboratory and in small plots in the field. In each experiment, the fungicides were compared with a positive (insecticide) and a negative control (water). Four fungicides were assessed in the laboratory, each with five doses based on basis of a tenfold dilution starting at the field-recommended dose. The mortality rate was evaluated after 24 hours and the lethal dose 50% (LD50) was determined for each product. In the field, six fungicides were tested at the recommended dose. The effect of each product was compared on the basis of the number of S. mosellana adults caught alive with an insect vacuum sampler (Vortis®) on the morning after the treatments. Both experiments showed a significant effect of several fungicides tested on S. mosellana adults. Chlorothalonil was not toxic for S. mosellana, but tebuconazole, fluxapyroxad and azoxystrobin all induced significant mortality rates. [less ▲]

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See detailThe influence of lithology on the mechanical strength and porosity of terra-cotta, the case study of Marrakech region (Morocco).
El Boudour El Idrissi, Hicham ULg; Daoudi, Lahcen; Collin, Frédéric ULg et al

Poster (2015, May 19)

The ceramic pastes in Marrakech region are prepared on the base of six types of raw materials of different lithologies. Various products are manufactured. The production consists of cooking utensils ... [more ▼]

The ceramic pastes in Marrakech region are prepared on the base of six types of raw materials of different lithologies. Various products are manufactured. The production consists of cooking utensils (based on schist, colluviums, quartzose sand and silt), decoration products (based on argillite, washing residues and soil), vases and gourds products (based on schist and soil), tiles (based on silt decantation) and traditional dishes (based on soil and argillite). In this study we elaborate bricks from the different raw material and we evaluate some of their physical properties after firing at 1050°C. In particular we measure the porosity to water and the mechanical strength of all the fired bricks. The aim is to compare the final product quality according to the origin (lithology) of the clayey raw material of the ceramic pastes. Based on our experiments, the bricks of the lower compressive strength (CS) and of the lower flexural strength (FS) are those based on sand (CS = 39 MPa; FS = 7 MPa), on silt decantation (CS = 25 to 39 MPa; FS = 10 to 18 MPa), and on schist and colluviums (CS = 20 to 51 MPa; FS = 6 to 17 MPa). Those of the highest values are based on argillites (CS = 33 to 102 MPa; FS = 13 to 28 MPa). The other pastes are characterized by intermediate values. The porosity ranges between 5 to 27%. The bricks based on silt decantation have the greatest values (20 to 27%), whereas those based on argillite have the lower values (5 to 10%). Those physical properties are, in most cases, in agreement with the requested values of the bricks industry. We conclude that such raw materials have high perspective to manufacture structural products of high performance in mechanical strength and thermal insulation. [less ▲]

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See detailOrganometallic-mediated radical synthesis of well-defined ethylene-vinyl acetate statistical and block copolymers
Demarteau, Jérémy ULg; Kermagoret, Anthony; Jérôme, Christine ULg et al

Poster (2015, May 18)

The copolymerization of ethylene (E) and vinyl acetate (VAc) is of high interest for polymer industry. Nevertheless, the control of the macromolecular parameters of ethylene-vinyl acetate copolymers (EVAs ... [more ▼]

The copolymerization of ethylene (E) and vinyl acetate (VAc) is of high interest for polymer industry. Nevertheless, the control of the macromolecular parameters of ethylene-vinyl acetate copolymers (EVAs) is difficult to achieve. Herein, we report the controlled radical copolymerization of these monomers by organometallic-mediated radical polymerization (OMRP) using Co(acac)2 as controlling agent. The ethylene pressure is varied from 10 to 100 bar and we discuss the effect of this parameter on kinetics, level of control and copolymer composition. EVAs are synthetized accordingly with low dispersities and ethylene content reaches up to 57 mol%. The precision design of EVA-containing block copolymers, i.e. PVAc-block-EVA, is also addressed. [less ▲]

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See detailQuestion Intégrative - Médecine - Module Système Nerveux
Pasquet, Coralie ULg; Van de Poël, Jean-François ULg; Schaffer, Patrick ULg et al

Poster (2015, May 18)

Au cours du premier quadrimestre de l’année académique 2014 - 2015, une nouvelle activité a été proposée aux 270 étudiants inscrits en 3ième année du grade de Bachelier en Médecine à l’Université de Liège ... [more ▼]

Au cours du premier quadrimestre de l’année académique 2014 - 2015, une nouvelle activité a été proposée aux 270 étudiants inscrits en 3ième année du grade de Bachelier en Médecine à l’Université de Liège. Cette activité a été réalisée dans le cadre du « Module Système Nerveux ». [less ▲]

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See detailNew efficient bicomponent organocatalysts for the chemical fixation of CO2 onto epoxides: a theoretical study
Alves, Margot ULg; Méreau, Raphaël; Grignard, Bruno ULg et al

Poster (2015, May 18)

Regarding the economic and environmental issues, valorising CO2 as a C1 feedstock for producing useful building blocks is seducing as it is a free and abundant waste resulting from the human activity ... [more ▼]

Regarding the economic and environmental issues, valorising CO2 as a C1 feedstock for producing useful building blocks is seducing as it is a free and abundant waste resulting from the human activity. Cyclic carbonates are useful compounds that found application as green solvents, electrolytes for lithium battery or monomers for polycarbonates or polyurethanes synthesis. These cyclocarbonates can be synthesized with a total atom economy by chemical fixation of CO2 onto epoxides using organometallic complexes or organocatalysts. To date, although this area of research has been the subject of many studies, the identification and development of (organo)catalysts highly efficient under mild experimental conditions still remains challenging. In this context, we developed a new organocatalytic platform based on the use of ammonium salts in combination with single or double hydrogen bond donor activators derived from fluorinated alcohols that showed unexpected booster effect. In this contribution, the ammonium/fluoroalcohol promoted CO2/propylene oxide coupling was investigated through detailed kinetic studies by IR spectroscopy under pressure and results were compared to the most efficient organocatalysts based on ammonium salts and (multi)phenolic derivatives that were reported in the literature. In order to finely understand the reaction mechanism, this study was completed by molecular modeling. DFT calculations showed that the addition of H-bond donors (HBD) with hexafluoroisopropanol functionalities modified the mechanism of the ammonium promoted coupling of CO2 with epoxides. HBDs dramatically decreased the epoxide ring-opening step barrier which highlights the key role of the fluorinated activators in stabilizing the intermediates and transitions states by inter- and intra-molecular hydrogen bonds. [less ▲]

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See detailNon-isocyanate polyurethane: from the monomer synthesis to foamed materials
Gennen, Sandro ULg; Alves, Margot ULg; Tassaing, Thierry et al

Poster (2015, May 18)

Polyurethane (PU) is one of the most important polymers in our everyday life with numerous applications such as thermosets, thermoplastics, elastomers, adhesives, sealants, coatings, rigid and flexible ... [more ▼]

Polyurethane (PU) is one of the most important polymers in our everyday life with numerous applications such as thermosets, thermoplastics, elastomers, adhesives, sealants, coatings, rigid and flexible foams... Classically, PUs are produced by a step-growth polymerization between diols and diisocyanates. However, isocyanates are harmful upon prolonged exposure to vapours which can lead to health issues such as asthma and skin irritation. In addition, isocyanates are produced from even more toxic and explosive phosgene. Due to these problems in combination with increasing regulatory scrutiny, there is today a need to develop isocyanate- and phosgene free- PU synthesis, also called non-isocyanate polyurethane or NIPUs. One of the most promising alternatives to the conventional synthesis of PU relies on the step-growth polymerization between bicyclic carbonate monomers and diamines, but until now, obtaining high molar mass NIPUs in a short time still remains a challenge. This study will be focused on three objectives: 1) The synthesis of CO2-sourced biscyclic carbonates by CO2/epoxide coupling using new highly efficient bicomponent organocatalysts allowing the fast conversion of epoxides into the corresponding cyclic carbonates under mild and solvent-free conditions. 2) The synthesis of high molar mass NIPUs from CO2-sourced monomers and diamines thanks to the use of efficient organocatalysts. A series of organic compounds interacting with cyclic carbonates by hydrogen bonding were first identified and their catalytic activity was highlighted by a model reaction between ethylene carbonate and a primary amine before extrapolation to NIPU synthesis. 3) The scCO2-assisted foaming of CO2-sourced NIPUs with production of potential carbon zero-emission materials with low thermal conductivity [less ▲]

Detailed reference viewed: 210 (4 ULg)
See detailPrerparation of graphene oxide-poly(methyl methacrylate) nanocompposites by a precipitation polymerization process and their dielectric and rheological characterization
Alkarmo, Walid ULg; Thomassin, Jean-Michel ULg; Macosko, Christopher et al

Poster (2015, May 18)

The graphene sheet, a flat monolayer composed of sp2-bonded carbon atoms packed into a two-dimensional honeycomb structure, has attracted a tremendous attention due to its extraordinary electrical ... [more ▼]

The graphene sheet, a flat monolayer composed of sp2-bonded carbon atoms packed into a two-dimensional honeycomb structure, has attracted a tremendous attention due to its extraordinary electrical, thermal, and mechanical properties. Graphene nanosheets–poly(methyl methacrylate) GN/PMMA nanocomposites were prepared via a precipitation polymerization process in a water/methanol mixture and thermal or chemical reduction of graphene oxide (GO). Scanning electron and transmission electron microscopies confirmed that the precipitate consists of polymer particles (<1μm) surrounded by the GO sheets. The GO sheets acts as a surfactant and adsorbs on the interface between polymerized PMMA particles and solvent mixture. Parallel dielectric and rheological characterization demonstrated that the thermal reduction is a quite fast process without significant degradation of the polymer. In addition, the main increase in electrical conductivity occurred during the first minutes of the thermal treatment but continued for about 30 min. The absence of dramatic change in the storage modulus confirmed that the increase in conductivity was not due to alteration of the particle dispersion. The addition of GO sheets had a dramatic influence on the glass transition (Tg) temperature of PMMA with an increase of 8 °C at only 0.2 wt %. This Tg increase has been attributed to the restricted mobility of PMMA chains which have been grafted onto the graphene surfaces during the in-situ polymerization. However, at GO content higher than 0.7 wt %, the glass transition decreases. This drop may be attributed to the increase in the number of stacked graphene layers. The obtained GN/PMMA composites not only have enhanced mechanical properties but also achieved electrical conductivity higher than 10 −2 S/m at 0.4 wt % of GO. The study should open up new opportunities in the design of GN-based polymer nanocomposites. [less ▲]

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See detailAssessment of the species richness of highly eusocial bees according with habitat in Gabon
Fabre Anguilet, Edgard ULg; Bengone Ndong, Toussaint; Nguyen, Bach Kim ULg et al

Poster (2015, May 18)

Bees are among the most e ective pollinators. These insects include honeybee and stin- gless bee. In Africa, habitat loss is the main threat to these insects. This loss of habitat is largely due to ... [more ▼]

Bees are among the most e ective pollinators. These insects include honeybee and stin- gless bee. In Africa, habitat loss is the main threat to these insects. This loss of habitat is largely due to various human activities. An evaluation of the richness of social bees in three locaties in Gabon (Central Africa) was conducted from October 2013 to March 2014: Kougouleu who underwent deforestation and implantation of food crops, forest area Mas- sengalini in bu er zone of protected area of Lope and Lekokodiba in logging concession of Preccious Woods Gabon. For this, a collection was conducted using yellow traps lled with a mixture of water and honey and using a hand vacuum in 20 sites in each area. The number of species was compared to that estimated there are about thirty years. Eleven species of social bees (Apis mellifera adansonii and ten stingless bee species) were collected, of which 5 to Kougouleu, 8 to Massengalini and 11 to L ekokodiba. Honeybee has been collected in all localities. Forest localities are distinguished from Kougouleu by higher species diversity. This di erence is highly signi cant (Kruskal-Wallis 2 = 45.362, df = 2 and p-value<0.001). A decrease of approximately 50% of the number of stingless bee species in 30 years was found to Kougouleu, while the number of social bee species varies little in forest localities. Our study shows that the loss of forest habitat causes a decline in the species richness of social bees and stingless bees are more sensitive to this loss as the honeybee. [less ▲]

Detailed reference viewed: 51 (9 ULg)
See detailIntercalation of cationic aliphatic polyphosphates between montmorillonite nanosheets towards flame-retardant polymer materials
Carion, Stéphan ULg; Lecomte, Philippe ULg; Thomassin, Jean-Michel ULg et al

Poster (2015, May 18)

Among the strategies used to impart flame-retardant properties to polymer materials, the most effective ones include the addition of phosphorous compounds such as organic polyphosphates and the dispersion ... [more ▼]

Among the strategies used to impart flame-retardant properties to polymer materials, the most effective ones include the addition of phosphorous compounds such as organic polyphosphates and the dispersion of layered silicates (nanoclays). The aim of this work is to combine both approaches by the dispersion of nanoclays, organomodified by cationic aliphatic polyphosphates, into a polymer matrix. In this work, the synthesis of an aliphatic polyphosphate end-capped by an imidazolium cation followed by its intercalation between montmorillonite nanoclays sheets is reported. In a first step, the polyphosphate was synthesized by ring-opening polymerization of the corresponding cyclic phosphate using 1-(11-hydroxy-undecyl)-3-methylimidazolium bromide as initiator. This polymerization was catalyzed by DBU and a thiourea derivative. This polymer was characterized by different techniques (31P and 1H NMR, SEC, TGA, DSC). Finally, the cationic end-functionalized polymer was exchanged with sodium cations present in montmorillonite. The intercalation of the polyphosphate between the clay nanosheets was proved by X-Ray Diffraction (XRD) and thermogravimetric analysis (TGA). This last technique was also used to determine the influence of the intercalation on the thermal stability of the polyphosphate.polyphosphates, into a polymer matrix. In this work, the synthesis of an aliphatic polyphosphate end-capped by an imidazolium cation followed by its intercalation between montmorillonite nanoclays sheets is reported. In a first step, the polyphosphate was synthesized by ring-opening polymerization of the corresponding cyclic phosphate using 1-(11-hydroxy-undecyl)-3-methylimidazolium bromide as initiator. This polymerization was catalyzed by DBU and a thiourea derivative. This polymer was characterized by different techniques (31P and 1H NMR, SEC, TGA, DSC). Finally, the cationic end-functionalized polymer was exchanged with sodium cations present in montmorillonite. The intercalation of the polyphosphate between the clay nanosheets was proved by X-Ray Diffraction (XRD) and thermogravimetric analysis (TGA). This last technique was also used to determine the influence of the intercalation on the thermal stability of the polyphosphate. [less ▲]

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See detailAliphatic polyphosphates: a promising family of polymers for drug delivery
Vanslambrouck, Stéphanie ULg; Clément, Benoit; Riva, Raphaël ULg et al

Poster (2015, May 18)

Thanks to their biocompatibility and biodegradability, polyphosphates are appealing polymers for biomedical applications. In contrast to polyesters, polyphosphate properties and functionality are easily ... [more ▼]

Thanks to their biocompatibility and biodegradability, polyphosphates are appealing polymers for biomedical applications. In contrast to polyesters, polyphosphate properties and functionality are easily tuned via the chemical nature of the lateral chains. In this work, a series of amphiphilic PEO-block-polyphosphate copolymers were synthesized by organo-catalyzed ring-opening polymerization of cyclic phosphates. These polymers are directly dissolved in water in the absence of any organic solvent and they self-assemble to form nanoparticles Our work aims at changing the lateral chain of polyphosphates to investigate the influence of this structural modification on (i) the size of the nanoparticles, (ii) the critical aggregation concentration, (iii) the encapsulation of an hydrophobic drug in the core of the nanoparticles and, finally, (iv) the release of the drug. [less ▲]

Detailed reference viewed: 46 (13 ULg)
See detailVaricella-Zoster Virus (VZV) assemblons interplay with PML bodies
Lebrun, Marielle ULg; Thiry, Marc ULg; Sadzot, Catherine ULg

Poster (2015, May 15)

Using a virus expressing the small capsid protein fused to an eGFP tag (eGFP-ORF23 VZV), we recently identified, in the nuclei of infected cells, the presence of dynamic capsid aggegrates. Because we ... [more ▼]

Using a virus expressing the small capsid protein fused to an eGFP tag (eGFP-ORF23 VZV), we recently identified, in the nuclei of infected cells, the presence of dynamic capsid aggegrates. Because we believe that these structures might represent sites of preferential caspid assembly and by analogy with HSV-1, we referred to them as “VZV assemblons”. Structures resembling these assemblons and identified as capsids entrapped in some “PML-cages” were recently described in the nuclei of wild-type VZV infected cells (Reichelt et al., 2011). We then wonder if there was a link between these independent observations. When we infected MeWo cells in which the expression of each PML subunit is downregulated by shRNA, VZV assemblons still formed. Immunostaining of MeWo cells infected by eGFP-ORF23 VZV with an antibody against the PML protein showed that VZV assemblons only partially colocalize with PML bodies. However, overexpression of PML-I-eGFP in HEK293 cells followed by infection with a tagRFP-T-ORF23 VZV, where the ORF23 protein is fused to a red tag, showed a complete colocalization is complete. The same result was obtained with all tested PML isoforms. This suggests that the partial colocalization in normal cells could be due to the expression level of PML proteins. Altogether, these results suggest that rather than a progressive accumulation of newly formed capsids within PML cages, it is likely that PML protein is recruited to the sites where VZV assemblons develop. It correlates with the fact that the number of PML bodies decreases with the infection. Obviously, even if this phenomenon might impede the egress of a substantial amount of capsids and, in this regard, limit the infection progression, all the tested cell lines are permissive to VZV. It would then be interesting to investigate the relationship between VZV assemblons and PML bodies in latent or non permissive VZV infection models. [less ▲]

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See detailInteraction of HTLV-1 Tax with minichromosome maintenance proteins modulates viral transcription
Barez, Pierre-Yves ULg; Carpentier, Alexandre ULg; Boxus, Mathieu et al

Poster (2015, May 13)

First human retrovirus discovered, HTLV-1 infects approximately twenty million individuals worldwide. HTLV-1 is the causative agent of different diseases that include adult T-cell leukemia (ATL) and a ... [more ▼]

First human retrovirus discovered, HTLV-1 infects approximately twenty million individuals worldwide. HTLV-1 is the causative agent of different diseases that include adult T-cell leukemia (ATL) and a neurodegenerative disorder called HAM/TSP (Human associated myelopathy/ Tropical spastic paraparesis). We are interested in the mechanisms of transformation by the viral Tax oncoprotein. We previously showed that Tax interacts with the minichromosome maintenance MCM2-7 helicase and affects host cell replication (Boxus et al, 2012 Blood 119:151). In this project, we focused on the role of the MCM2-7 complex in transcription. We first show by chromatin immunoprecipitation that the MCM2-7 is recruited onto the 5'-LTR promoter. The 5’-LTR does however not act as a DNA replication origin. In contrast, MCM2-7 activates viral transcription as revealed by luciferase reporter assays. Interaction between Tax and MCM2-7 also affect expression of cellular genes. Together, our data thus demonstrate that the viral promoter is not a replication origin and that interaction between Tax and MCM2-7 is involved in the viral transcription. [less ▲]

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See detailMagneto-optical trapping of iron atoms
Crauwels, Justine ULg; Huet, Nicolas ULg; Krins, Stéphanie ULg et al

Poster (2015, May 13)

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See detailRegulation of Tissue Factor by Epithelial-to-Mesenchymal Transitions: Impacts for the metastatic progression.
Francart, ME; Bourcy, M; Lambert, J et al

Poster (2015, May 13)

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Peer Reviewed
See detailSurfactin: a receptor-independent bacterial elicitor of plant immunity?
Luzuriaga Loaiza, Walter ULg; Legras, Aurelien; Crowet, Jean-Marc ULg et al

Poster (2015, May 13)

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See detailInvestigation on a hydrogen maser cavity in the TE111 mode : first results
Van Der Beken, Emeline ULg; Léonard, Daniel; Counet, Arnaud et al

Poster (2015, May 13)

Results of our preliminary investigation on a hydrogen maser cavity in the unusual TE111 mode are presented. Hydrogen masers use the transition at 1420.405MHz between the two hyperfine levels F = 0 and F ... [more ▼]

Results of our preliminary investigation on a hydrogen maser cavity in the unusual TE111 mode are presented. Hydrogen masers use the transition at 1420.405MHz between the two hyperfine levels F = 0 and F = 1 of the 1s1/2 ground state of the hydrogen atom. 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. In view of a future development of a hydrogen maser in the TE111 mode we performed a thorough analysis of the maser physics for this mode. Different simulations carried out are compared with first measurement results obtained for such a cavity. [less ▲]

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See detailGrowth factor-induced angiogenesis requires uPAR on endothelial cells
Paques, Cécile ULg

Poster (2015, May 13)

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See detailCheckpoints modulation by the human T-lymphotropic virus type 1 (HTLV-1) Tax protein : towards new therapeutic approaches
Carpentier, Alexandre ULg; Barez, Pierre-Yves ULg; Boxus, Mathieu et al

Poster (2015, May 13)

HTLV-1 infects approximately 15 million people worldwide and causes several diseases. This virus is responsible for the adult T-cell leukemia (ATL) and for a chronic neuropathology (TSP/HAM). There is ... [more ▼]

HTLV-1 infects approximately 15 million people worldwide and causes several diseases. This virus is responsible for the adult T-cell leukemia (ATL) and for a chronic neuropathology (TSP/HAM). There is currently no satisfactory treatment for these diseases. Among the proteins encoded by HTLV-1, Tax appears to play an important role in the mechanisms leading to pathogenicity. We are interested in the mechanisms of cell transformation by the Tax viral oncoprotein. In particular, we aim at understanding the interplay between Tax and the DNA damage response (DDR). We show that transient expression of Tax results in DNA damage, cell cycle arrest and activation of the DDR. In fibroblasts, cell cycle arrest occurs at the G1 and G2 phases depending on the p53 background. In contrast, HTLV-1 infected lymphocytes proliferate continuously and appear to be adapted to the checkpoints. This mechanism of checkpoint adaptation thus allows ongoing proliferation despite the presence of genomic lesions. Quantification of the rates of NHEJ and homologous recombination indicates that HTLV-1 infected cells require very efficient DNA repair for survival. Therefore, we propose a novel therapeutic approach based on the principle of synthetic lethality using inhibitors of DNA repair. [less ▲]

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See detailAn encapsulation-dehydration method for the long-term storage of cyanobacterial strains in the BCCM/ULC collection.
Crahay, Charlotte ULg; Mari, Maude; Wilmotte, Annick ULg

Poster (2015, May 13)

Long-term genetic and functional stability is a fundamental requirement for the maintenance of microorganisms. Cryopreservation is the preferred method for the long-term storage of many micro-organisms ... [more ▼]

Long-term genetic and functional stability is a fundamental requirement for the maintenance of microorganisms. Cryopreservation is the preferred method for the long-term storage of many micro-organisms, including cyanobacteria. The BCCM/ULC collection currently holds over 200 cyanobacterial strains as living cultures, but only 62 are maintained in a cryo-preserved state. The main limiting factors are the low levels of survival of some strains, as well as the long periods required to recover from cryopreservation, and thus the inability to rapidly deliver strains to clients.. The BRAIN-be project PRESPHOTO (preservation of photosynthetic micro-algae in the BCCM collections) (www.presphoto.ulg.ac.be) aims to improve the preservation of cyanobacterial and diatoms in the BCCM/ULC and BCCM/DCG collections, respec-tively. The encapsulation-dehydration is often considered as a promising alternative to the traditional cryopreservation method for recalcitrant microalgal strains. In this technique, cyanobacterial cultures are entrapped in calcium-alginate beads, osmotically dehydrated (traditionally with sucrose solutions), then evaporatively desiccated in a sterile air flow, or over silica gel and subsequently cryopreserved. In this study, the encapsulation-dehydration method was evaluated as potential long-term preservation technique of cyanobacterial strains. The effects of several factors on the viability of 4 strains have been investigated to determine which are the most important for the successful cryopreservation. In particular, several cryoprotectants (i.e. sucrose, PEG or mannitol), methods of beads dehydration (i.e. under a laminar flow or with silica gel) were tested. We have also compared storage at -70°C and in liquid nitrogen (-196oC). A pre-cultivation step in KCl was also tested for its ability to enhance desiccation tolerance. In addition, the use of alginate dissolution buffer following thawing was also considered. In the final phase of the project, the selected cryopreservation protocols will be tested on a large set of strains. In addition, an independent validation of the protocols will be also performed by both partners of the project (BCCM/DCG and the Culture Collection of Algae and Protozoa). [less ▲]

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See detailChaotic Bohmian trajectories for the hydrogen atom
Cesa, Alexandre ULg; Struyve, Ward ULg; Martin, John ULg

Poster (2015, May 13)

In Bohmian mechanics, a single-particle quantum system is described in part by its wave function and in part by the actual position of the particle. The trajectory of the latter can be computed using the ... [more ▼]

In Bohmian mechanics, a single-particle quantum system is described in part by its wave function and in part by the actual position of the particle. The trajectory of the latter can be computed using the guiding equation. This equation states that the velocity of the particle is proportional to the usual probability current associated with its wave function. In this work, we study the quantum trajectory of a single particle in a Coulomb potential whose eigenstates are the well known eigenstates of the hydrogen atom. More precisely, we focus on the relation between chaotic Bohmian trajectories and the motion of wave function nodes. At wave function nodes i.e., where the wave function vanishes, the velocity is not defined which generically induces vorticity. In order to probe chaos, we compute Poincaré map and we numerically evaluate Lyapounov exponents, which characterize the divergence of close trajectories as time increases. For the 2d Coulomb potential, although the superposition of two eigenstates with different energies can lead to an arbitrary high number of moving nodes of the wave function, the Bohmian trajectories display no trace of chaos. This absence of chaotic behaviour originates from the existence of a constant of motion. Therefore, the motion and the number of nodes do not constitute a sufficient condition for the emergence of chaos in Bohmian mechanics. For superpositions of more than two eigenstates, there is no constant of motion, there are moving nodes and we find that the Bohmian trajectories are chaotic. [less ▲]

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See detailDesign and synthesis of PET-probes targeting AMPA subtype receptors
Deverdenne, François ULg; Claes, Giselle ULg; Goffin, Eric ULg et al

Poster (2015, May 13)

The AMPA subtype of glutamatergic receptors is the main actor in the fast excitatory neurotransmission in the mammalian central nervous system. These receptors are involved in the expression and the ... [more ▼]

The AMPA subtype of glutamatergic receptors is the main actor in the fast excitatory neurotransmission in the mammalian central nervous system. These receptors are involved in the expression and the maintenance of the long-term potentiation, a phenomenon closely linked to cognitive and memorization processes. Based on experimental data, it also appears that glutamatergic systems are involved in several pathological diseases. For instance, a lack of glutamatergic neurotransmission is observed in cognitive disorders or schizophrenia and an excessive activity is observed in Parkinson or Huntington diseases. The in vivo study of glutamate receptors mapping and its evolution appears to be an essential step for a better understanding of its implications. However, according to the literature, design of such a probe remains difficult due to the lack of specificity of the probes. Taking into account the potential in vitro and in vivo activity and specificity of benzothiadizine dioxides (BTDs) acting as AMPA positive allosteric modulators, we are investing the development of new compounds of this class radiolabeled with a fluorine-18 atom. Hence, we are currently developing new series of BTDs characterized by the presence of a fluorine atom and a 7-phenoxy-substituent that are expected to be more active and more specific. Finally, pharmacological tests to evaluate the best candidates for the radiochemical synthesis and in vivo evaluations are currently in progress. [less ▲]

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See detailMultiscale model of the human cardiovascular system: healthy and pathological behaviours
Kosta, Sarah ULg; Negroni, Jorge; Lascano, Elena et al

Poster (2015, May 13)

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See detailTransport of Bose-Einstein Condensates through Aharonov-Bohm rings
Chrétien, Renaud ULg; Dujardin, Julien ULg; Petitjean, Cyril ULg et al

Poster (2015, May 13)

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 magnetic flux φ. We specifically investigate the effects 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. The latter allows for the description of incoherent transport and corresponds to a classical sampling of the evolution of the quantum bosonic many-body state through effective GP trajectories. We find that resonant transmission peaks move with an increasing interaction strength and can be suppressed for sufficiently strong interaction. We also observe that the coherent transmission blockade due to destructive interference at the AB flux φ = π is very robust with respect to the interaction strength. [less ▲]

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See detailTowards the identification of cis-elements responsible for the high expression of HMA4, an essential gene for zinc hyperaccumulation in Arabidopsis halleri.
Spielmann, Julien ULg; Nouet, Cécile ULg; Scheepers, Maxime ULg et al

Poster (2015, May 13)

A. halleri is a Zn and Cd hypertolerant and hyperaccumulator plant which stores metals in shoot vacuoles. One key step for hyperaccumulation is a highly efficient root-to-shoot translocation of metals ... [more ▼]

A. halleri is a Zn and Cd hypertolerant and hyperaccumulator plant which stores metals in shoot vacuoles. One key step for hyperaccumulation is a highly efficient root-to-shoot translocation of metals. The Zn/Cd plasmamembrane pump HMA4 (heavy metal ATPase 4) plays a central role in this process and is involved in xylem loading/unloading. Moreover, HMA4 is overexpressed in A. halleri compare to its non-tolerant and non-hyperaccumulator sister, Arabidopsis thaliana. The HMA4 overexpression is determined by a combination of gene triplication and cis-regulatory changes increasing transcription levels of each three HMA4 copies. In this study, we are focusing on the two most active HMA4 promoters and we aim to identify the cis-elements underlying high expression of HMA4 in A. halleri using promoter-reporter constructs. Through deletion analysis, two important regions for a high expression have been identified. Ongoing analysis of more detailed deletions will be presented. [less ▲]

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See detailTiO2 templated films used as photoelectrode for solid-state DSSC applications: Study of the solid electrolyte infiltration by Rutherford Backscattering Spectrometry
Dewalque, Jennifer ULg; Colson, Pierre ULg; Mathis, François et al

Poster (2015, May 10)

Liquid-state dye-sensitized solar cells can suffer from electrolyte evaporation and leakage. Therefore solid-state hole transporting materials are investigated as alternative electrolyte materials ... [more ▼]

Liquid-state dye-sensitized solar cells can suffer from electrolyte evaporation and leakage. Therefore solid-state hole transporting materials are investigated as alternative electrolyte materials. However, in solid-state dye-sensitized solar cells, optimal TiO2 films thickness is limited to a few microns allowing the adsorption of only a low quantity of photoactive dye and thus leading to poor light harvesting and low conversion efficiency. In order to overcome this limitation, high surface area templated films are investigated as alternative to nanocrystalline films prepared by doctor-blade or screen-printing. Moreover, templating is expected to improve the pore accessibility what would promote the solid electrolyte penetration inside the porous network, making possible efficient charge transfers. In this study, films prepared from different structuring agents are discussed in terms of microstructural properties (porosity, crystallinity) as well as effect on the dye loading and Spiro-OMeTAD (2,2',7,7'-tetrakis-(N,N-di-p-methoxyphenylamine)9,9'-spirobifluorene) solid electrolyte filling. Different techniques such as transmission electron microscopy (TEM), atmospheric poroellipsometry (AEP) and UV-visible absorption spectroscopy (UV-vis.) have been used to describe the microstructural features of the films. Besides, we have implemented Rutherford backscattering spectrometry (RBS) as an innovative non-destructive tool to characterize the hole transporting materials infiltration. Templated films show dye loading more than two times higher than nanocrystalline films prepared by doctor-blade or screen-printing and solid electrolyte infiltration up to 88%. [less ▲]

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See detail[18F]FMT: a reliable PET tracer for in vivo evaluation of dopaminergic dysfunction in Parkinson’s Disease rat model.
Seret, Alain ULg; Becker, Guillaume ULg; Bahri, Mohamed Ali ULg et al

Poster (2015, May 09)

Background: Rat models of Parkinson’s disease (PD), such as lesioned rats with 6-hydroxydopamine (6-OHDA), are useful for studying dopamine (DA)-related functions. 6-[18F]fluoro-m-tyrosine (6-[18F]FMT) is ... [more ▼]

Background: Rat models of Parkinson’s disease (PD), such as lesioned rats with 6-hydroxydopamine (6-OHDA), are useful for studying dopamine (DA)-related functions. 6-[18F]fluoro-m-tyrosine (6-[18F]FMT) is an effective PET tracer to evaluate of DA terminals integrity and L-aromatic amino acid decarboxylase (AAAD) metabolic pathway. However, there are currently no available quantitative PET studies using [18F]FMT in 6-OHDA lesioned rats. In this context, we investigated the feasibility of in vivo PET study using [18F]FMT on 6-OHDA PD’s model. Methods: 10 µg of 6-OHDA were injected into the right medial forebrain bundle (MFB) of male Sprague-Dawley rats (n=8). As control, sham-treated rats (n=8) were injected with vehicle only but otherwise treated identically. Striatal DA presynaptic activity was assessed by dynamic [18F]FMT PET, 30 min after benserazide pretreatment. Structural T2-weighted brain images were acquired on a 9.4T MRI and were used for co-registration. After normalization on a MRI template, kinetic analysis was performed by “Patlak Reference” model, using PMOD software. Results: Striatal accumulation of [18F]FMT was observed in rats pretreated with benserazide, a peripheral AAAD inhibitor. As consequence of the 6-OHDA-lesion, significant decrease of [18F]FMT accumulation was recorded in the striatum ipsilateral to the lesion. Lesioned rats had dramatically reduced uptake constant Ki in the ipsilateral striatum compared to the contralateral striatum (p<0.001) and to the ipsilateral striatum of sham-treated rats (p<0.005). The Ki ratio (Ipsi./Contra.) was equivalent to 94% in the sham group and dropped to 41% in the lesioned group. Conclusions: [18F]FMT PET enables us to quantify loss of DA presynaptic function in unilaterally 6-OHDA lesioned rats. These results encourage us to pursue further investigations in a longitudinal way and to monitor the progression of the dopaminergic dysfunction in more moderate and gradual preclinical PD models. [less ▲]

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See detailSpray-drying synthesis of Na3V2(PO4)2F3 as cathode material for Li/Na ion batteries
Eshraghi, Nicolas ULg; Caes, Sébastien ULg; Cloots, Rudi ULg et al

Poster (2015, May 08)

In this communication, Na3V2(PO4)2F3 (NVPF) powder with a NASICON-type structure is synthesized for the first time by spray-drying method. The effects of molar ratio of precursors, inlet temperature and ... [more ▼]

In this communication, Na3V2(PO4)2F3 (NVPF) powder with a NASICON-type structure is synthesized for the first time by spray-drying method. The effects of molar ratio of precursors, inlet temperature and heat treatment temperature on the powder purity and particle morphology were investigated. Structural and microstructural characterizations were carried out by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Best electrochemical properties, from specific capacities of 94 mAh .g-1 at C/15 to 80 mAh.g-1 at 1C in li-ion batteries, were obtained for powders dried at 180°C and fired at 600°C. These preliminary results show that spray-drying technique is suitable for obtaining complex powders with a very good homogeneity leading to very good electrochemical properties. [less ▲]

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See detailThe seamod.ro operational stochasting Black Sea forecasting system
Vandenbulcke, Luc ULg; Capet, Arthur; Grégoire, Marilaure ULg et al

Poster (2015, May 08)

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See detailCatalytic epuration of biogaz
Claude, Vincent ULg; Toye, Dominique ULg; Heinrichs, Benoît ULg et al

Poster (2015, May 08)

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See detailSelf-defining memories and self-concept clarity: A comparative study of depressed patients, bipolar patients and healthy subjects
Wagener, Aurélie ULg; Boulanger, Marie ULg; Blairy, Sylvie ULg

Poster (2015, May 06)

Depressed and bipolar patients suffer from autobiographical memory (AM) deficits. For instance, depressed patients present an overgeneralisation and a mood congruence biases. Indeed, these patients seem ... [more ▼]

Depressed and bipolar patients suffer from autobiographical memory (AM) deficits. For instance, depressed patients present an overgeneralisation and a mood congruence biases. Indeed, these patients seem to have difficulties to recall specific and positive memories. The present study focusses on a particular kind of memories: the self-defining memories (SDMs). SDMs are highly pertinent for self-building: they help to define in the most clearly way our perception of ourselves. Because SDMs have not been studied a lot since yet in these two disorders, our goal is to assess the impact of general AM biases on SDMs. Then, the present study pursues two main aims: 1) To assess SDM’s characteristics, 2) To assess the relationship between SDM and self-concept clarity. To reach our objective, depressed and bipolar patients are compared to healthy subjects. Participants are asked to complete SDMs exercises that are recalling six important events which happened in their life. These SDMs are assessed on four variables: specificity, impact, meaning making, contain. Self-concept clarity and mood are also assessed. Until now, 17 depressed patients, 16 bipolar patients and 18 healthy controls participate in this study. Preliminary results do not highlight difference between our groups on specificity. Marginal effects appear for meaning making with healthy subjects recalling more meaning making events. Results show that depressed patients present a mood congruence. The final results will be presented during the convention, as data-collection is on-going and will end in April. Experimental and clinical implications of our results will be discussed. [less ▲]

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See detailProteome variations in Macrobrachium rosenbergii exposed to chlordecone: a gel-free proteomic approach
Lafontaine, Anne ULg; De Pauw, Edwin ULg; Forget-Leray, Joelle et al

Poster (2015, May 06)

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See detailHigher male than female recombination rate in cattle is controlled by genetic variants effective in both sexes
Kadri, Naveen Kumar ULg; Harland, Chad ULg; Coppieters, Wouter ULg et al

Poster (2015, May 05)

We herein study genetic recombination in three dairy cattle populations from France, New-Zealand and the Netherlands. We apply a new phasing algorithm extracting familial information suited for large half ... [more ▼]

We herein study genetic recombination in three dairy cattle populations from France, New-Zealand and the Netherlands. We apply a new phasing algorithm extracting familial information suited for large half-sib families to reconstruct haplotypes and detect cross-overs (CO). The software is robust to genotyping and map errors. We identify more than 2,000,000 CO events in sperm cells transmitted by 3008 sires to 94,603 offspring, and more than 500,000 CO events in oocytes transmitted by 11,497 cows to 25,390 offspring. When measured in identical family structures, the average number of CO in males (24.0) was found to be larger than in females (21.8). In males, recombination rates were higher closer to telomeres whereas in females, recombination rates dropped at both centromeres and telomeres (probably as a result of lower informativity). The heritability of the global recombination rate (GRR) was close to 0.20 in males and to 0.08 in females. Genetic correlation ranged from 0.38 to 0.69 depending on the population, indicating that shared variants are influencing GRR in both genders. Haplotype-based genome-wide association studies revealed four genome-wide significant QTL, including two previously identified ones (involving REC8 and RNF212). For all QTLs, there was a positive correlation between haplotype effects across sexes, ranging from 0.35 to 0.68. We selected two reference panels of respectively 122 and 215 bulls sequenced at cover > 15x to impute variants in the New-Zealand and French populations. All variants identified by next-generating sequencing in 5 Mb windows encompassing the QTL peaks were imputed with Beagle in order to perform a sequence-based association study. For three QTLs, we identified missense mutations in genes known to be involved in meiosis among the most significantly associated variants. These variants were perfectly associated with the haplotypes underlying the QTL effects. The variant identified in RNF212 had already been reported, whereas missense mutations in MLH3 (N408S) and HFM1 (S1189L) are new findings. Surprisingly, variants previously identified in REC8 did not capture the QTL effect whereas variants in RNF212B, PPP1R3E, BCL2L2, HOMEZ and PABPN1 had much stronger association with the phenotype. The three missense mutations were significant in both genders with two of them accounting for approximately 10% of the genetic variance in males (the allelic substitution effect being approximately equal to one additional CO per genome). Our results are very different from reports of recombination in other species. For instance, in human, recombination rate is higher in females, distinct variants affect recombination rate in males and females and the genetic correlation is close to 0 whereas in cattle, we observed a higher recombination rate in males controlled by shared variants effective in both sexes. [less ▲]

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See detailPrioritizing likely causative genes in GWAS identified risk loci for immune-mediated inflammatory disorders using cell-type specific eQTL information.
Docampo Martínez, Elisa ULg; Fang, Ming ULg; Dmitrieva, Joelia Borisnova ULg et al

Poster (2015, May 05)

Background/Purpose: Immune-mediated inflammatory disorders (IMIDs) share many genetic risk factors. Pleiotropy may exist at different levels and most of the underlying mechanisms are still to be uncovered ... [more ▼]

Background/Purpose: Immune-mediated inflammatory disorders (IMIDs) share many genetic risk factors. Pleiotropy may exist at different levels and most of the underlying mechanisms are still to be uncovered. GWAS have identified hundreds of risk loci for IMIDs but causative genes have been identified in only a handful of cases. Recent fine-mapping efforts indicate that only a minority of risk variants are coding. This suggests that most risk variants will be regulatory hence affecting disease risk via eQTL effects. Methods: To aid in the identification of causative genes for IMIDs, we generated transcriptome information (HT12 arrays) for six blood cell types (CD4, CD8, CD19, CD14, CD15 and platelets) and intestinal biopsies at three anatomical locations (ileum, colon, rectum) for 350 healthy Caucasians. The same individuals were genotyped with SNP arrays interrogating > 700K variants, augmented by imputation from the 1KG project. To detect cis-eQTL we tested variants within 0.5 megabase windows centered on the tested probe. The nominal p-value of the best SNP within a cis-window was Sidak-corrected for the window-specific number of independent tests. The corresponding best, Sidak-corrected p-values for each probe were jointly used to estimate their respective false discovery rate.To identify likely causative genes in GWAS identified risk loci variants and also better understand pleiotropic effects, we (i) developed a method that quantifies the correlation between “disease association pattern” (DAP) and “eQTL association pattern” (EAP) and provides an empirical estimate of its significance, and (ii) evaluated the effect of fitting known risk variants as covariates in the eQTL analysis following Nica et al. (2010). We applied both approaches to celiac disease (CE) and rheumatoid arthritis (RA) and the second one to type one diabetes (T1D), multiple sclerosis (MS), systemic lupus erythematosus (SLE), ankylosing spondylitis (AS) and psoriasis (PSO). Results: We detected > 16000 significant cis-eQTL, with a degree of sharing between cell types ranging from 38 to 90% highlighting the utility of our multi-tissue panel. GWAS variants were drivers of ciseQTL effects across the different tissues in 399 tests (23.6%), mostly in CD4 cells, and pinpointing 64 new gene-disease associations (3.7%). The number of shared loci and shared eQTL were highly correlated (rho=0.66).RA and SLE showed the highest degree of sharing. Conclusions: We identified new potential candidate genes for IMIDs and characterized pleiotropic effects through ciseQTL mapping in GWAS loci. These findings could shed a light on IMIDs pathogenesis and co-occurrence. Latest results will be presented. [less ▲]

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See detailUse of GEOS-Chem for the interpretation of long-term FTIR measurements at the Jungfraujoch and other NDACC sites
Mahieu, Emmanuel ULg; Bovy, Benoît ULg; Bader, Whitney ULg et al

Poster (2015, May 04)

We present recent and ongoing investigations using 3D CTM GEOS-Chem model simulations for the interpretation of long-term FTIR measurements performed at selected NDACC sites.

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See detailCharacterization of almond kernel oils of five almonds varieties cultivated in Eastern Morocco
Houmy, Nadia ULg; Mansouri, Farid; Ben Moumen, Abdessamad et al

Poster (2015, May 03)

This study focuses on characterization of almond kernel oils extracted mechanically from five sweet almond varieties Marcona, Fournat, Ferragnes, Ferraduel and Beldi), cultivated in eastern Morocco. Oil ... [more ▼]

This study focuses on characterization of almond kernel oils extracted mechanically from five sweet almond varieties Marcona, Fournat, Ferragnes, Ferraduel and Beldi), cultivated in eastern Morocco. Oil content, physicochemical parameters, triacylglycerol and fatty acid compositions were determined. Analyzed oils showed low acidity values that range between 0.77 – 0.88 %, peroxide values range between 6.43 – 16.39 meq/kg and Iodine values range between 98.42 – 103.90%. The principal fatty acid of almond kernel oils is oleic acid (C18:1); oils of Ferragnes-Ferraduel and Beldi varieties show higher values of C18:1 respectively of 72.87 and 71.62 %, however Fournat almond kernel oil shows the lowest content of C18:1 (63.54%). HPLC analysis of triglycerides was carried out, and results show that analyzed almond kernel oils are characterized by the dominance of trioleylglycerol (OOO) that contents range between a minimum of 31.48 % for Fournat’s oil and 43.82% for Ferragnes-Ferraduel’s oil. The oxidative stability of almond kernel oils was determined by rancimat tests as the induction period (IP, h recorded by a 743 Rancimat apparatus Metrohm, Switzerland). Results show that stability, of almond kernel oils is clearly influenced by the almond variety; Oxidative stability of tested almond kernel oils ranged between an IP = 20.28 h for Marcona oil and an IP =27.55 h for Ferragnes-Ferraduel. [less ▲]

Detailed reference viewed: 21 (4 ULg)
See detailCarbon dioxide, a cheap bio-sourced building block for cyclic carbonates and non-isocyanate polyurethanes
Gennen, Sandro ULg; Alves, Margot ULg; Tassaing, Thierry et al

Poster (2015, May 03)

Due to concerns about global warming combined with the decrease of fossil resources, new carbon feedstocks that are abundant, renewable, non-toxic, inexpensive and environmentally friendly must be ... [more ▼]

Due to concerns about global warming combined with the decrease of fossil resources, new carbon feedstocks that are abundant, renewable, non-toxic, inexpensive and environmentally friendly must be explored to produce chemicals. Besides the valorization of bio-based raw materials, the chemical transformation of carbon dioxide into added-value products has gained interest in both academia and industry. To date, the chemical fixation of CO2 onto epoxides with the formation of cyclic carbonates is one of the most promising ways to valorize CO2 at an industrial scale. Indeed, cyclic carbonates find applications as electrolytes in lithium ion batteries, as aprotic polar solvents or as useful intermediates for polycarbonates. Cyclic carbonates also react with primary amines to produce 2-hydroxyethylurethane. This reaction can be extrapolated to the synthesis of non-isocyanate polyurethanes (NIPU) by polyaddition of bifunctional cyclic carbonates with diamines.5 This study aims (i) at developing a new highly efficient organocatalyst for the synthesis of cyclic carbonates under mild experimental conditions and (ii) their valorization as monomers to produce non-isocyanate polyurethanes. First, we have identified a bicomponent organocatalyst, composed of a judicious combination of an organocatalyst and an activator, for the very fast synthesis of cyclic carbonates from CO2 and epoxides under very mild reaction conditions. Kinetics of reactions were followed by online Raman spectroscopy measurements under pressure. NMR titrations were realized to evidence the mechanism of activation of this novel organocatalytic system that will be discussed in detail in this talk. The second objective relies on the development of new efficient organocatalysts for the synthesis of high molar masses NIPUs in short reaction times. Organic compounds interacting with the cyclic carbonate by hydrogen bonding were identified and their catalytic activity was demonstrated for model compounds. [less ▲]

Detailed reference viewed: 161 (2 ULg)
Full Text
See detailLarge-scale polarization alignments of quasars in the JVAS/CLASS 8.4-GHz surveys
Pelgrims, Vincent ULg; Hutsemekers, Damien ULg

Poster (2015, May)

We analyse the large sample of polarization measurements of the flat-spectrum radio sources of the JVAS/CLASS 8.4-GHz surveys compiled by Jackson et al. (2007). We tested the uniformity of the ... [more ▼]

We analyse the large sample of polarization measurements of the flat-spectrum radio sources of the JVAS/CLASS 8.4-GHz surveys compiled by Jackson et al. (2007). We tested the uniformity of the polarization position angles for a wide range of angular (2D) and comoving (3D) separations and studied the several subsamples, dividing the main sample of 4155 sources regarding their object type (QSO, galaxies, radio sources,...). We found regions of the sky of about 20 degree radius in which quasars (only) have correlated polarization position angles. Those regions coincide with the regions of alignment at optical wavelength pinpointed in 1998 by Hutsemékers. [less ▲]

Detailed reference viewed: 23 (1 ULg)
Peer Reviewed
See detailComparison of individuals’ susceptibility to false memory induced by both DRM and misinformation paradigms involving emotional material
Martial, Charlotte ULg; Dehon, Hedwige ULg

Poster (2015, May)

False memories induced by the DRM procedure (“Deese, Roediger and McDermott”; Deese, 1959; Roediger & McDermott, 1995) or the misinformation procedure (in which a person’s recollection of a witnessed ... [more ▼]

False memories induced by the DRM procedure (“Deese, Roediger and McDermott”; Deese, 1959; Roediger & McDermott, 1995) or the misinformation procedure (in which a person’s recollection of a witnessed event is altered after exposure to misinformation about this event; Loftus et al., 1978) are due to errors in source monitoring processes (e.g., Johnson et al., 1993) and one might expect the correlation between these false memories quite positive. However, the few laboratory studies comparing the DRM paradigm and the misinformation paradigm show small (Zhu et al., 2013) or no correlation (Ost et al., 2013) between the false memories elicited by these procedures but these studies vary in terms of methodological details. For instance, false memories from the misinformation procedure involved emotional content while those from the DRM procedure only included neutral materials. This study investigated the relationship between false memories induced by two different paradigms (a DRM task and a misinformation procedure) both involving an emotional material. Participants (N = 154) completed an emotional variant of the DRM (neutral, positive and negative lists) and the misinformation (neutral, positive and negative images) procedures and their performances on both tasks were compared. Although both paradigms reliably induced false memories in participants, our analyses revealed only a marginally weak positive correlation (r = .147, p = .051) between misinformation and DRM false memories using emotional variants. These results support the idea that DRM and misinformation false memories are underpinned by (at least in part) different mechanisms and that the previous mixed results were not due to the specific content of the DRM or the misinformation task used. [less ▲]

Detailed reference viewed: 107 (2 ULg)