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See detailAtypical myopathy in Europe: 2006-2009
Van Galen, Gaby ULg; Atypical Myopathy Alert Group; Votion, Dominique ULg

Poster (2010, June 18)

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See detailDendrochronology to date mettalic reinforcements in roof frames
Maggi, Christophe ULg; Pagès, Gaspard ULg; Hoffsummer, Patrick ULg et al

Poster (2010, June 17)

Studies about metallic reinforcements in historical monuments multiply themselves. Thanks to building archaeology and dendrochronology, we are able to determine the archaeological contexts to which the ... [more ▼]

Studies about metallic reinforcements in historical monuments multiply themselves. Thanks to building archaeology and dendrochronology, we are able to determine the archaeological contexts to which the metallic elements belong and to date them. One of the objectives of the research is to list the different appearances of iron in roof frames and to identify the function of each. At the end, the principal aim is to create a typo-chronological inventory which will index all the iron reinforcements met in medieval roof frames of the Meuse basin (Belgium). [less ▲]

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See detailLa sensibilité à l'anxiété chez l'enfant : Les facteurs de risque et de protection au sein de son milieu familial
Stassart, Céline ULg; Etienne, Anne-Marie ULg

Poster (2010, June 11)

La sensibilité à l'anxiété (AS)est la peur des sensations corporelles liées à l'anxiété. Plusieurs études constatent qu'une grande proportion de la variance de l'AS des filles et la totalité de la ... [more ▼]

La sensibilité à l'anxiété (AS)est la peur des sensations corporelles liées à l'anxiété. Plusieurs études constatent qu'une grande proportion de la variance de l'AS des filles et la totalité de la variance de l'AS des garçons s'expliquent par des facteurs environnementaux. L'objectif est de dégager, chez l'enfant au sein du milieu familial, les facteurs de risque et de protection de la sensibilité à l'anxiété (AS). Dans un premier temps, le lien entre divers états émotionnels des parents et la présence d'une AS chez leur enfant sera étudiée. La part contributive des mécanismes d'apprentissage (transmission d'information, renforcement, modeling) de l'AS lorsque l'enfant ressent des symptômes corporels sera également analysée. Différents effets seront testés: le type d esymptômes sur lequel l'apprentissage porte (douleur/anxiété), la source (père/mère) et la diversité des apprentissages. Dans un second temps, afin d'affiner les liens entre les états émotionnels des parents, les expériences d'apprentissage au sein du milieu familial et la présence d'une sensibilité à l'anxiété chez l'enfant, l'influence de deux modérateurs sera testée: l‘intelligence émotionnelle de l'enfant et les apprentissages sociaux. Les hommes apprennent qu'il est moins acceptable pour eux que pour les femmes d'exprimer leurs craintes. Les mères parlent plus volontiers de leurs inquiétudes et donc, lorsqu'elles présentent des manifestations anxieuses, elles peuvent plus facilement expliquer à l'enfant que ses peurs sont irrationnelles contrairement aux pères qui préféreront ne pas en parler. Que se passerait-il si le père parlait de ses craintes sachant qu'un père qui oserait exprimer sa détresse sera perçu de façon plus marquante par son enfant qu'une mère qui ose le faire? [less ▲]

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See detailIs posterior cerebral hypometabolism always predicitve of dementia in Parkinson's disease?
Deville, Benjamin ULg; Lemaire, Christian ULg; Degueldre, Christian ULg et al

Poster (2010, June 08)

In Parkinson's disease, altered activity in posterior associative cortices has often been associated with dementia. It remains to be determined if this pattern is a reliable marker of a progression toward ... [more ▼]

In Parkinson's disease, altered activity in posterior associative cortices has often been associated with dementia. It remains to be determined if this pattern is a reliable marker of a progression toward dementia in patients without demonstratable dementia. In this retrospective analysis, we used positron emission tomography to study resting-state cerebral fluodeoxyglucose uptake in 8 healthy controls and 8 Parkinson's disease patients who did not have evidence of dementia at the time of assessment. For those patients, clinical follow up was available and we know that they did not meet dementia criteria on average 10,37 years after assessment. The results show that patients had reduced fluodeoxyglucose uptake mostly localised in the right hemisphere and including precuneus, superior temporal, middle temporal and inferior parietal cortices. It also includes right insula. These cerebral activity predominating in posterior cortices is present in non-demened patients but is not always predictive of dementia within the 10,34 years. [less ▲]

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See detailCo‐construction du langage: le rôle de la mère dans les séquences de rectifications
Collombel, Marie; Maillart, Christelle ULg; Caet, Stéphanie et al

Poster (2010, June 07)

Notre recherche a pour but de mieux repérer ce qui semble faciliter chez l'enfant tout venant son développement linguistique et communicationnel, afin de mettre en place des stratégies éducatives adaptées ... [more ▼]

Notre recherche a pour but de mieux repérer ce qui semble faciliter chez l'enfant tout venant son développement linguistique et communicationnel, afin de mettre en place des stratégies éducatives adaptées aux enfants présentant des troubles du langage. Dans une étude longitudinale des interactions mère-enfant chez trois enfants tout-venant entre 1 an 6 mois et 3 ans, notre équipe s'est penchée sur un phénomène interactionnel au croisement de l'appropriation du système linguistique et de son usage : les rectifications. Nos analyses soulignent le rôle clé de la mère ainsi que les similarités et les différences entre les dyades. La sensibilisation à ces dimensions de la communication auprès de parents d'enfants dysphasiques dans le cadre d'un projet de guidance parentale pourrait favoriser la mise en place de formes d'interaction facilitant le développement langagier et communicationnel des enfants. [less ▲]

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See detailImpact of an anxious social situation on emotional facial expressions (EFE) recognition in children
Dethier, Marie ULg; Taskin, Asliane; Blairy, Sylvie ULg

Poster (2010, June 04)

Socially anxious children have difficulties to interact adequately with others. The core characteristic of social anxiety, the fear of being negatively evaluated by others, may among others, be based on ... [more ▼]

Socially anxious children have difficulties to interact adequately with others. The core characteristic of social anxiety, the fear of being negatively evaluated by others, may among others, be based on problems with the decoding of other persons’ emotional facial expression (EFE). Up to now, the research on EFE recognition in socially anxious children has produced mixed results. Whereas some studies reported differences between anxious and healthy children in EFE recognition (e.g., Simonian, Beidel, Turner, Berkes, & Long, 2001), others didn’t find such differences (Melfsen & Florin, 2002). In this study, we addressed two new issues in the investigation of EFE recognition in socially anxious children. Firstly, we investigated self-esteem. Socially anxious children show low confidence in one’s cognitive and social abilities. Furthermore, high self-esteem is related to high capacities of EFE recognition (Garfield, Rogoff, & Steinberg, 1987), and more generally to high level of social functioning (Serretti et al., 1999 ; Shapira et al., 1999). Indeed, the perception of ourselves depends on the way we think others people perceive us. Secondly, past researches have investigated this issue in low anxious situations and thus, not in situations in which social anxious individuals feel threatened. The originality of the present study is that it addresses the relationship between EFE recognition performance and self-esteem in children placed in an anxious social situation. We predicted a low capacity to decode EFE in socially anxious children. Moreover, we hypothesised a relationship between a low self-esteem and difficulties to decode accurately EFE in an anxious social situation. Seventy children (8 – 12 years) were placed in an anxious social situation of performance in which they were instructed to count aloud backwards, beginning at 200 in increments of 13. Children assessed their emotional feeling state, including their degree of anxiety, before and after the anxious social situation. Furthermore, children were assessed on an EFE decoding test consisting of 16 photographs depicting EFE of happiness, anger, disgust, and sadness. For each photograph, they evaluated the presence of nine types of emotions on a 7-point Likert scale. They also completed the Self-Perception Profile for Children (Harter, 1985). No correlations emerged between the accuracy of EFE recognition and an increase of anxious feelings after the anxious social situation. However, self-esteem was correlated with performance on the EFE recognition test, r (70) = -.33, p < .01. Moreover, the lower the child’s level of self-esteem was, the more he/she perceived negative emotions (fear, anger, disgust, and shame) in EFE of anger. In conclusion, social anxiety doesn’t seem to interfere with EFE recognition performance in an anxious social situation. However, low level of self-esteem in children appears to be associated with deficits and interpretative bias in EFE recognition in an anxious social situation. The recognition of the expression of anger, an emotion socially threatening, seems particularly biased in children with low level of self-esteem. [less ▲]

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See detailCapacities of cognitive and emotional empathy in relationship to interpersonal difficulties in alcohol dependant patients (AD)
Dethier, Marie ULg; Blairy, Sylvie ULg

Poster (2010, June 04)

The term empathy refers to two related human abilities: mental perspective taking (cognitive empathy) and the vicarious sharing of emotions (emotional empathy). The main object of this study was to ... [more ▼]

The term empathy refers to two related human abilities: mental perspective taking (cognitive empathy) and the vicarious sharing of emotions (emotional empathy). The main object of this study was to explore the relationship between capacities of both aspects of empathy and their relationships with interpersonal difficulties in alcohol-dependant patients (AD). The research in alcoholism empathy has focalised around one aspect of cognitive empathy - the capacity to infer an emotional state-, and that essentially on the basis of emotional facial expression (EFE) recognition. However, researchers have shown little interest in the investigation of the other aspects of cognitive empathy. The present study focuses on the capacity to infer interpersonal intentions and on emotional empathy. As documented by the research on EFE decoding, AD patients show deficits in cognitive empathy. In this study, we investigated their capacity to infer interpersonal intentions in social situation. We hypothesized that AD patients compared to healthy individuals and to depressed patients will attributed more intentions of reject and of aggressiveness to other people on the basis of their EFE. In this study, emotional empathy was defined as the modulation of the emotional feeling state of the participant in function of the EFE display by other people. We hypothesized that the modulation in AD patient will be different from the one of healthy people in function of the Cloninger subtype of alcoholism (Cloninger, Bohman, Sigvardsson, 1987). This emotional reactivity will be more important in Type II alcoholism and less important in Type I alcoholism. As Mimicry facilitates feelings of empathy in healthy people, it was also investigated. Twenty type I AD patients, 20 type II AD patients, 20 depressed patients, and 20 healthy subjects participated to the study. The alcoholism subtype identification was maid according to the criteria from von Knorring, Bohman, von Knorring, and Oreland (1985). The participant completed questionnaires assessing the quality of interpersonal relationships, their usual quantity of alcohol consumption, and, for AD patients, their level of alcohol dependence. Their capacity to recognise faces was evaluated by the Benton facial recognition test. The empathy tasks were computerized. In the cognitive empathy task, the participants had to evaluate the adequacy (in a 7-point Likert scale) between a film of a face changing from a neutral EFE to an emotional EFE (the photographs come from the material of Matsumoto & Ekman, 1988) and an adjective descriptive of personality. Each adjective was weighted on the interpersonal dimensions of reject, aggressiveness, dominance, and affiliation. In the emotional empathy task, the participants had to evaluate their own emotional feeling state (in a 7-point Likert scale; from very negative to very positive) after watching a series of films depicting emotional faces (same material as before). During this task, the participant’s face was filmed in order to assess mimicry. The differences of empathy capacities between AD patients and control participants (depressed and healthy) are discussed in reference to the characteristics of their interpersonal relationship. [less ▲]

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See detailpCO2 dynamics and related airice CO2 fluxes during sea-ice growth and decay in an ice-tank experiment
Delille, Bruno ULg; Thomas, D. N.; Dieckmann, Gerhard et al

Poster (2010, June)

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See detailInfluence of the matrix on the In Source Decay of permethylated glycans during MALDI-TOF analysis
Smargiasso, Nicolas ULg; De Pauw, Edwin ULg

Poster (2010, June)

Introduction In source decay (ISD) is a common phenomenon occurring very rapidly during ionization process in the source of MALDI-MS instruments and resulting in the presence of well resolved peaks of ... [more ▼]

Introduction In source decay (ISD) is a common phenomenon occurring very rapidly during ionization process in the source of MALDI-MS instruments and resulting in the presence of well resolved peaks of fragments in mass spectrum. While they make interpretation of spectra more complex, these fragments were shown to be useful to sequence peptides and proteins. Concerning glycans, only a few reports were published, using different matrices on various samples and therefore making it difficult to compare. In this context, the goal of this work is to perform a systematic study allowing to define optimal conditions to induce ISD of glycans or, inversely, to minimize this phenomenon in the study of more complex mixtures. Methods Glycans were purchased from Sigma-Aldrich. Iodomethane was used in DMSO/NaOH to permethylate the glycans. This reaction was stopped by water and permethylated glycans were extracted by chloroform. Spectra were recorded on a Bruker Ultraflex II in positive ion mode. 2,5-dihydroxybenzoic acid (DHB) and 6-aza-2-thiothymine (ATT) were prepared at 20 mg/ml in 50 % acetonitrile, 0.1 % formic acid solution. 9-aminoacridine (9-AA) was dissolved at saturation in a 50 % acetonitrile, 0.1 % formic acid and further diluted 4 times in the same solution. α-Cyano-4-hydroxycinnamic (HCCA) acid was prepared at 20 mg/ml in 97 % acetone, 0,1 % formic acid. In some spots, LiI was added to obtain Li+ adducts instead of Na+ adducts. Preliminary data In source fragmentation of permethylated Lacto-N-difucoHexaose I and LS tetrasaccharide B was first studied in DHB. While the MS/MS of the Na+ adducts of these compounds (performed by LID) produces intenses B and Y fragments, those resulting from in source fragmentation are mainly oxonium ions, resulting from the cleavage of a glycosylic bond without any exchange of hydrogen atoms. These oxonium fragments were also obtained for lithium adducts. It was previously described that these fragments are produced by the cleavage of a protonated glycosidic bond. These ions carry their positive charge on a trivalent oxygen atom and are therefore not present on the spectra as sodium adducts. Since the peaks of protonated glycans are very low in MALDI spectra, it would indicate that protonation of glycosidic bonds of permethylated glycans would strongly favor a fragmentation reaction. Different matrices were tested to compare their ability to induce in source fragmentation of permethylated glycans. Interestingly, ATT gave similar results comparing to DHB while HCCA showed a lesser ability to promote in source fragmentation. However, the most striking result came from the use of 9-AA. This matrix, which is usually used in negative ion mode, was able to produce easily sodium adducts ions of permethylated glycan with a satisfying signal to noise ratio in positive ion mode. Moreover, practically no in source fragmentation was observed with this matrix. The few produced fragments were B ions but no oxonium ions were detected. Presence of these B fragments was increased for Li+ adducts. As 9-AA is the most basic of tested matrices, the absence of oxonium ions could result from its inability to transfer protons to the glycosidic bond of permethylated glycans. 9-AA could therefore become a matrix of choice to study complex mixtures of glycans, by reducing artefact peaks produced by ISD. Novel aspect ISD of permethylated glycans is induced by DHB while 9-AA strongly favors the presence of molecular ions. [less ▲]

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See detailOvergenerality Bias and these Consequences in Borderline Personality Disorder.
Boulanger, Marie ULg; Smets, Virginie; Blairy, Sylvie ULg

Poster (2010, June)

Objective: The present study investigated the Autobiographical Memory (AM) in borderline disorder population. AM is an entity that encompasses the individuals’past personnal experiences. Previous ... [more ▼]

Objective: The present study investigated the Autobiographical Memory (AM) in borderline disorder population. AM is an entity that encompasses the individuals’past personnal experiences. Previous researches have shown disturbances in AM among several psychiatric disorders such as depression, schizophrenia and bipolar disorder. This disturbances take the overgeneral retrieving form. Thus, when patients were asked to retrieve a specific event located in time and place, they recalled an overgeneral event. This deficit is not an isolated phenomen. Indeed the researches showed that AM deficits is related to decreasing of the ability to solve interpersonnal problem (Evans et al., 1992; Goddard et al., 1996) and impairments to project onself into the specific future events (D’argembeau et al., 2008; Williams et al., 1996). Impairments to respond adequately to social problems or to concrete plans for the future create hopelessness and to contribute to suicide attempt (Arie et al., 2008). Given the high risk of suicide or suicide attempts present in the Bordeline Personnality Disorder (BPD), consideration of AM in this population is appropriate. The aim of the present study was investigate the AM, the projection into the future and the problem solving in patients suffering from BPD. Method: 21 subjects BPD and 21 healthy controls participated in this study. First, the participants were asked to complete TeMA (validated French versions of AMT by Neumann & Philippot, 2006). Participants were instructed to generate specific past and future memories in response to cues words. Secondly, they were had to complete the OTT, they were asked to yield the most solutions as possible to daily problems. Finally the depression was controlled as well as neuropsychological variables. Results: The subjects with BPD recalled less specific past events and imagined less specific future events than healthy subjects (t(40) = 2.21, p = .031; t(40) = 3.4, p = .001, respectively). In addition, the number of past and future specific events was marginally correlated (r(42) = .31, p = .051). However, no difference between two groups on OTT and no correlation between past specificity and problem solving emerged. Discussion: As other clinical populations, the subjects with a BPD encounter deficits to retrieve specific past events. Moreover, these impairments are associated with deficits to imagine specific future events. Nevertheless, the ability to generate specific events was not related to the ability to solve problem. The observation of reduced specificity in the generation of autobiographical material is particularly clinically relevant. Indeed, difficulty in imagining the future may contribute to relapse. In conclusion, more systematic measure of this ability should be taken in both research and clinical fields. [less ▲]

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See detailNREM slow wave oscillation rebound after sleep deprivation : effect of aging
Lafortune, M; Viens, I; Poirier, G et al

Poster (2010, June)

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See detailVHHs as model proteins to investigate amyloid fibril formation: Fibril stability and effect of seeding and cross-seeding on aggregation kinectics
Chavignon, Chloé ULg

Poster (2010, June)

The term "amyloidosis" covers a group of diseases associated with the deposition of protein aggregates organized into amyloid fibrils in different organs. About forty amyloidosis are known so far, amongst ... [more ▼]

The term "amyloidosis" covers a group of diseases associated with the deposition of protein aggregates organized into amyloid fibrils in different organs. About forty amyloidosis are known so far, amongst which Alzheimer's disease, type II diabetes and immunoglobulin amyloidosis [1]. Although the mechanism of amyloid fibrils formation at the molecular level is not yet completely understood, it has been shown that the capacity to form amyloid fibrils in vitro is an intrinsic property of all polypeptide chains [1]. The choice of model proteins to investigate the aggregation process in vitro is therefore no more restrained to proteins involved in amyloidosis but can be settled on a wide variety of proteins. In this study, we have chosen to investigate the mechanism of amyloid fibrils formation by two variable domains of camelid heavy-chain antibodies (referred to as VHHs or nanobodies), cAb-HuL6 and cAb-BcII10, and this choice was motivated by the following reasons: - First, VHHs are small monomeric proteins (~14 kDa) presenting a high stability and a high solubility [2], which permits their expression with a high yield (20-40 mg.L-1). - Second, a wide range of stable mutants of these two VHHs is available. Mutations located at the disulfide bond [3,4], the CDRs [3] and the framework have been introduced. Characterisation of the aggregating properties of these mutants will allow the investigation of the impact of these structural elements on the process of fibril formation. In order to determine conditions in which cAb-HuL6 and cAb-BcII10 are more susceptible to form intermediates and thus amyloid fibrils, heat-induced unfolding experiments at pHs comprised in a range from 2,5 to 9,5 have been monitored by intrinsic fluorescence, ANS binding and circular dichroism. Then, aggregation experiments have been performed in the selected conditions and the presence of amyloid fibrils has been acknowledged by thioflavineT fluorescence experiments and electronic microscopy. We will discuss the kinetics of aggregation obtained in the absence and the presence of seeding/cross-seeding. [1] Chiti and Dobson, Annu. Rev. Biochem., 75, 2006, 333-366. [2] Dumoulin et al., Protein Sci., 11, 2002, 500-515. [3] Saerens et al., J. Mol. Biol., 352, 2005, 597-607. [4] Saerens et al., J. Mol. Biol., 377, 2008, 478-488. [less ▲]

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See detailThe Venus OH Nightglow Distribution
Soret, Lauriane ULg; Gérard, Jean-Claude ULg; Piccioni, Giuseppe et al

Poster (2010, June)

The first identification of the OH airglow in the terrestrial mesosphere was made in 1950 by Meinel [1950]. Recently, the unexpected presence of the OH nightglow was observed in the Venus mesosphere by ... [more ▼]

The first identification of the OH airglow in the terrestrial mesosphere was made in 1950 by Meinel [1950]. Recently, the unexpected presence of the OH nightglow was observed in the Venus mesosphere by Piccioni et al. [2008] using a limb profile from the Visible and Infra-Red Thermal Imaging Spectrometer (VIRTIS) instrument on board the Venus Express spacecraft. They clearly identified the (1-0) and (2-1) transitions at 2.80 and 2.94 µm, respectively and the (2-0) band at 1.43 µm. Additional bands belonging to the Δv=1 sequence also appear to be present longward of the (1-0) band. In a preliminary study of characteristics of the OH emission distribution, Gérard et al. [2010] pointed out a correlation between the OH(Δv=1) and the O2(a1Δ) nightglow intensities. In Soret et al. [2010], the full dataset of VIRTIS-M limb observations of the OH Venus nightglow has been corrected from the thermal emission of the planet and analyzed to determine its characteristics. Based on 3328 limb profiles, the study shows that the emission is highly variable. No clear dependence of the airglow layer altitude versus the antisolar angle is established. The peak brightness appears to decrease away from the antisolar point even if the variability at a given location is very strong. Some correlation between simultaneous observations of the intensity of the OH and the O2(a1∆) emissions has also been detected, presumably because atomic oxygen is a common precursor to the formation of O2(a1∆) and O3, whose reaction with H produces excited OH. A relation given in the one-dimensional photochemical model of Krasnopolsky [2009] has been used to link the OH and the O2(a1∆) airglows through the hydrogen flux at 130 km. It appeared that using a constant flux did not fill well the simultaneous OH and O2 observations. Either the flux has to vary with the distance to the antisolar point or other dimensions have to be involved. [less ▲]

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See detailA proxy tool-box for assessing southern ocean biological carbon pump efficiency.
Dehairs, F.; Cardinal, D.; Cavagna, A.-J. et al

Poster (2010, June)

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See detailA ‘cook book’ method for dioxin & PCBs analysis
Focant, Jean-François ULg; Shirkhan; Patterson Jr

Poster (2010, June)

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See detailKraft RB : classification of relevant variables with Random Forests
Sainlez, Matthieu ULg

Poster (2010, June)

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See detailImpact of morphosyntactic complexity in sentence comprehension in children with SLI
Leclercq, Anne-Lise ULg; Majerus, Steve ULg; Jacob, Laura et al

Poster (2010, June)

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See detailBrain-computer interface in disorders of consciousness: answering simple questions with a P3 speller
Noirhomme, Quentin ULg; Chatelle, Camille ULg; Kleih, Sonja et al

Poster (2010, June)

Objective: In the recovery from coma, the acquisition of command following represents an important milestone, indicating emergence from the vegetative state (Schnakers et al., 2009). In some patients ... [more ▼]

Objective: In the recovery from coma, the acquisition of command following represents an important milestone, indicating emergence from the vegetative state (Schnakers et al., 2009). In some patients, recovery of consciousness may precede motor recovery. Brain-computer interfaces (BCI) might permit these patients to show non-motor dependent signs of awareness and in a next step might enable communication. This study aimed at testing to what extent an EEG-based BCI could help detecting signs of awareness and communication in disorders of consciousness. We employed a P300 based BCI where healthy volunteers and patients with locked-in syndrome and in a minimally conscious state were asked to answer yes or no to simple questions by paying attention to one out of four auditorily presented stimuli (‘yes’, ‘no’, ‘stop’, ‘go’). Methods: We studied 13 patients with a minimally conscious state (MCS, 5 TBI – 8 anoxic, mean time post injury 70±109 months; mean age 42 ± 21) and 2 in pseudo-coma or locked in syndrome (LIS; brainstem stroke, time post injury 26 and 46 months; aged 63 and 29)) and 16 healthy controls (aged 45±19). Patients were evaluated using the Coma Recovery Scale Revised (CRS-R). An auditory P300 four choice speller paradigm (Furdea et al., 2009) based on the BCI2000 system (Schalk et al., 2004) was used. 16-Channel EEG was recorded using a g.tec USBAmp amplifier. A trial constituted of 15 presentation of four sounds the order of presentation being pseudo-randomized (sound duration: ~400ms; inter-stimulus interval: ~600ms). After a training session of 4 trials, patients and healthy subjects were required to answer 10 or 12 questions, respectively. Questions were of the following kind: “Is your name Quentin?”, “Is your mother’s name Dorothée?”. A stepwise linear discriminant analysis based on the training session was used to classify the data and to provide online feedback. Offline, all training and testing sequences were pooled. Sequences with artifacts were discarded and a leave-one-out approach was used to classify the data. Results: Healthy subjects presented a mean correct response rate of 73% online and 93% offline. Note that online classification failed for one control subject due to a presumed change in cognitive strategy between training and testing sessions. LIS patients showed a correct response rate of 30 and 60% (online) and 36 and 79% (offline). Three MCS patients had a correct response rate of ≥50% offline (10, 18, 0% online and 50, 53, 57% offline). Two of these three patients did not show any command following at the bedside. The 10 remaining MCS cases showed online and offline correct answers <50% (mean 33±9% online and 25±13% offline). Conclusion: Our auditory P300-based BCI permitted functional interactive communication in 15/16 controls (online) and in all offline. Our data obtained in patients with locked-in syndrome and disorders of consciousness demonstrate the potential clinical usefulness of the technique following coma but also show lower accuracy in patients as compared to healthy volunteers. This might be due to fluctuating attentional levels and exhaustibility in the MCS and to the suboptimal EEG recording quality due to movement, ocular and respiration artifacts in these challenging patients. Further algorithmic developments should include automatic artifact detection and single trial classification. Despite the need for further improvement in BCI devices adapted to post-coma patients, our results already indicate that MCS patients without any clinical sign of command-following can employ a yes-no speller offering the hope of functional interactive communication and a possibility for decision making and autonomy. Bibliography Furdea A, Halder S, Krusienski DJ, Bross D, Nijboer F, Birbaumer N, Kübler A, 2009, An auditory oddball (P300) spelling system for brain-computer interfaces, Psychophysiology. May; 46(3):617-25. Schalk G., McFarland D.J., Hinterberger T., Birbaumer N., and Wolpaw J.R. 2004, BCI2000: A General-Purpose Brain-Computer Interface (BCI) System, IEEE Trans Biomed Eng, 51(6). Schnakers C, Vanhaudenhuyse A, Giacino J, Ventura; Boly M, Majerus S, Moonen G, Laureys S, 2009, Diagnostic accuracy of the vegetative and minimally conscious state: Clinical consensus versus standardized neurobehavioral assessment, BMC Neurology, 9 (35). [less ▲]

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See detailClick chemistry : radiolabelling of oligonucleotides with fluorine- 18 for PET
Kaisin, Geoffroy ULg; Flagothier, Jessica ULg; Mercier, Frédéric ULg et al

Poster (2010, June)

Oligonucleotides (ONs), especially small interfering RNA (siRNA), are promising therapeutic agents, but their pharmacokinetics and biodistributions are widely unknown. Positron Emission Tomography (PET ... [more ▼]

Oligonucleotides (ONs), especially small interfering RNA (siRNA), are promising therapeutic agents, but their pharmacokinetics and biodistributions are widely unknown. Positron Emission Tomography (PET) using fluorine-18 is a suitable technique to image and quantify such biological processes. The challenge for the radiochemist is to introduce this short half-life isotope (t1/2(18F)=109.7 min) onto oligonucleotides or, more generally, biomolecules. The most common technique requires the coupling of a prosthetic group bearing the radiotracer with the biomolecule. Current methods for labeling ONs with fluorine-18 have sub-optimal yields and require a long synthesis time.1 Click chemistry, e.g. 1,3-dipolar Huisgen cycloaddition of azides to alkynes, could be an efficient way to increase yields and reduce synthesis time. Conjugations with ONs are usually performed at 3’-ends using a well-chosen linker in order to limit degradation by exonucleases and to avoid alteration of hybridization properties and siRNA gene silencing efficiency. This also allows the development of universal solid supports used for the solidphase synthesis of ONs. Here we report the synthesis of three alkyne-bearing linkers , the synthesis and radiosynthesis of the complementary azido-bearing prosthetic groups (1-(azidomethyl)-4-[18F]- fluorobenzene) and coupling with functionalized ONs. [less ▲]

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See detailAutomated radiosynthesis of [18F]MPPF derivatives for imaging 5-HT1A receptors
Goblet, David ULg; Thonon, David ULg; Plenevaux, Alain ULg et al

Poster (2010, May 30)

TOPIC: Molecular Neuroimaging: from Bench to Bedside Automated radiosynthesis of [18F]MPPF derivatives for imaging 5-HT1A receptors Introduction: Dysfunction of the cerebral serotoninergic system is ... [more ▼]

TOPIC: Molecular Neuroimaging: from Bench to Bedside Automated radiosynthesis of [18F]MPPF derivatives for imaging 5-HT1A receptors Introduction: Dysfunction of the cerebral serotoninergic system is implicated in numerous neurodegenerative disorders such as Alzheimer disease’s, dementia, depression, anxiety, schizophrenia, and Parkinson disease’s. The 5-HT1A serotonin receptors are involved in several physiological functions including sleep, mood, neurogenesis and learning [1]. Consequently, there have been huge efforts in finding ligands for this receptor. [11C]WAY-100635 is a high affinity radioligand used for quantifying serotonin 5-HT1A receptors with positron emission tomography. An 18F-labeled radioligand is advantageous because of higher specific activity and physical/nuclear properties (t1/2= 109 min, 97% of positron decay and positron energy of 635 keV maximum). [18F]MPPF, a selective 5-HT1A antagonist derived from WAY-100635, is currently one of the most successful PET ligand used for 5-HT1A receptor imaging [2]. However the affinity is lower then WAY-100635 and the amount of [18F]MPPF reaching the brain is relatively low since MPPF is a substrate for p-glycoprotein [3]. Methods: In order to improve the brain uptake of the radiotracer, a desmethylated analog has been developed in our lab and preliminary in vitro studies show positive results [4]. Nevertheless, the radiosynthesis take place in two steps as a protecting group removal is needed. A one step procedure with a MPPF derivative could be of very great interest. We have synthesized many MPPF derivatives in our lab (modification on the phenylpiperazine moiety) and developed an automated radiosynthesis procedure for the production of these radiotracers. [18F]MPPF was chosen as the model compound. We used a GE Healthcare FASTlabTM module and made modifications to the [18F]FDG synthesis sequence and cassette. [18F]MPPF was synthesized by coupling of [18F]FBA with the corresponding amine. After coupling, the crude solution was diluted with water and passed through a tC18 cartridge for prepurification. After elution, the [18F]MPPF was purified by semi-preparative HPLC. Results: Total synthesis time, including purification was approximately 100 min. [18F]FBA and [18F]MPPF were obtained at a corrected yield of 55% (n=20) and 25% (n=5) respectively. The radiochemical purity, checked by radio-TLC and UPLC, was >95%. Conclusions: We have developed an automated method for [18F]MPPF and derivatives production using a commercial synthesizer (FASTlabTM from GE Healthcare) and a conventional HPLC system resulting in good yields and high (radio)chemical purity. By simply switching the vial containing the modified amine, an 18F-labeled MPPF derivative could be obtained. Radiosynthesis is still under optimization and the radiotracers synthesized need to be tested as suitable 5-HT1A radioligands. Acknowledgement: This work was supported by the Fondation Rahier. References: [1] Filip M., Bader M. et Al, Pharmacol Rep. 2009 Sep-Oct; 61(5):761-77 [2] Aznavour N, Zimmer L. Et Al, Neuropharmacology. 2007 Mar; 52(3):695-707 [3] Laćan G., Plenevaux A. et Al, Eur J Nucl Med Mol Imaging. 2008 Dec;35(12):2256-66 [4] Defraiteur C., Plenevaux A. et Al., Br J Pharmacol. 2007 Nov; 152(6):952-8 [less ▲]

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See detailIs Anosognosia in Alzheimer disease also observed for behavioural and personality changes?
Feyers, Dorothée ULg; Bastin, Christine ULg; Jaspar, Mathieu ULg et al

Poster (2010, May 28)

Anosognosia is a frequent manifestation in Alzheimer disease (AD) but its extent is not yet clearly established. While anosognosia for memory deficit has been widely reported, no study has simultaneously ... [more ▼]

Anosognosia is a frequent manifestation in Alzheimer disease (AD) but its extent is not yet clearly established. While anosognosia for memory deficit has been widely reported, no study has simultaneously explored anosognosia for personality and behaviour changes. We have tackled this question with 20 AD patients and 20 matched elderly subjects (ES). Participants (AD and ES) assessed their personality and their reactions in social situation both in current (S1) and past (S1_bef) time period. Assessment of these characteristics was also performed by relatives of the participants (R2 and R2_bef). Mann-Whitney test (p<0.05) were performed between discrepancy scores (calculated by comparing answers of subjects and relatives) obtained for AD and ES. A specific measure of anosognosia was also calculated by comparing S1 and R2. Statistical analyses demonstrated (1) that relatives of AD patients report more personality and behavioural changes across time (S1-S1_bef) than relatives of ES (R2–R2_bef); (2) that self-reported changes were not significantly different between AD patients and ES; (3) that anosognosia (S1-R2) was observed in AD patients for personality changes only. Results obtained support the hypothesis that anosognosia does not affect all domain in AD. Indeed, even if AD patients are no more able to assess their current personality, they perceive adequately their current reactions in social situations. [less ▲]

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See detailUsing phenomenology and mindset induction to assess the prospective function of mind-wandering
Stawarczyk, David ULg; Majerus, Steve ULg; D'Argembeau, Arnaud ULg

Poster (2010, May 28)

A notable feature of the human cognitive apparatus resides in its propensity to spontaneously generate thoughts uncoupled from the “here and now”. An important function of these cognitions, often referred ... [more ▼]

A notable feature of the human cognitive apparatus resides in its propensity to spontaneously generate thoughts uncoupled from the “here and now”. An important function of these cognitions, often referred to as mind-wandering, might be to create and/or update scripts, schemata, and future plans in long-term memory. In this study, we investigated this hypothesis by examining whether priming personal projects influenced the occurrence and characteristics of mind-wandering episodes during a subsequent, unrelated cognitive task, as assessed with an experience sampling method. We found that inducing particular mindsets that were related to personal goals (i.e., writing an essay about one’s personal projects) in comparison to a control baseline condition (i.e., writing an essay about a familiar itinerary) increased the number of future-oriented mind-wandering reports while participants performed the Sustained Attention to Response Task (SART). Furthermore, participants judged most of these thoughts as having a future-oriented function (i.e., they were related to planning, decision making, or reevaluating situations). Finally, as behavioral validation of participants’ subjective reports, we found that mind-wandering was positively linked with intra-individual variability (IIV) in response times, whereas reports of being concentrated on the SART were negatively linked with IIV. These data support the view that an important function of mind-wandering resides in the anticipation and planning of the future. [less ▲]

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See detailConsciousness of memory functioning in Alzheimer’s disease
Jaspar, Mathieu ULg; Feyers, Dorothée ULg; Bastin, Christine ULg et al

Poster (2010, May 28)

Metamemory is a multi-faceted concept which deals with the individual’s knowledge and control of memory functioning. Previous studies that have examined the ability of Alzheimer’s disease (AD) patients to ... [more ▼]

Metamemory is a multi-faceted concept which deals with the individual’s knowledge and control of memory functioning. Previous studies that have examined the ability of Alzheimer’s disease (AD) patients to monitor efficiently their memory processes provided contradictory results. These discrepancies between studies could be the result of two factors: the kind of memory task used (episodic, semantic) and the kind of memory process on which memory monitoring is assessed (encoding, maintenance, retrieval). In the present study, different aspects of memory monitoring in 21 AD patients and 21 healthy elderly participants were explored with two tasks : a semantic memory task assessing the feeling-of-knowing (FOK) accuracy for general knowledge and an episodic memory task assessing judgment-of-learning (JOL) and FOK accuracy for information associated to a specific spatiotemporal encoding context By comparison to healthy participants, AD patients exhibit impaired performance on episodic FOK accuracy but not on semantic FOK accuracy. Moreover, no difference was observed between the two groups on the JOL post-encoding accuracy. These results confirm that not all aspects of memory monitoring are impaired in AD. Indeed, although there exists an impairment of episodic FOK performance, semantic FOK and JOL post-encoding appear preserved. The dissociation between the two FOK performance could be due to recruitment of more automatic processes for metacognitive judgment on general knowledge (semantic FOK) than for metacognitive judgment based on specific recent experience (episodic FOK). Similarly, a global prediction during maintenance (JOL) could be based on more automatic processes than an item-by-item judgment during retrieval. [less ▲]

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See detailFeeling of doing in compulsive checking
Belayachi, Sanaa ULg; Van der Linden, Martial ULg

Poster (2010, May 28)

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See detailWhat is the impact of the sequence structure on implicit learning in children?
Lejeune, Caroline ULg; Schmitz, Xavier ULg; Lempereur, Stéphanie et al

Poster (2010, May 28)

It is generally admitted that implicit learning abilities are efficient early in childhood. However, few studies have explored the impact of the structure of the sequence on children’s performance in ... [more ▼]

It is generally admitted that implicit learning abilities are efficient early in childhood. However, few studies have explored the impact of the structure of the sequence on children’s performance in implicit learning tasks. The current research was intended to examine sequence learning abilities in children by comparing sequences of different structural characteristics. [less ▲]

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See detailThe links between dyslexia and inhibition deficits: do dyslexic children with an inhibition deficit have a specific reading profile?
Verhaegen, Clémence ULg; Schelstraete, Marie-Anne; Noël, Marie-Pascale

Poster (2010, May 28)

The present study focused on the nature of the reading disability of children with both dyslexia and inhibition deficit. Van der Schoot et al. (2000; 2004); Nossent et al. (2005); Nossent and Deroux (2006 ... [more ▼]

The present study focused on the nature of the reading disability of children with both dyslexia and inhibition deficit. Van der Schoot et al. (2000; 2004); Nossent et al. (2005); Nossent and Deroux (2006) showed that these children tended more to guess the words they read because these “guessers” found difficulties in suppressing false candidate words that are activated in the lexicon. To test this account, dyslexic children with and without inhibition deficit were presented a sentence reading task. To evoke guessing, each sentence contained a word or a pseudoword which closely resembled either a valid congruent or incongruent word. Our hypothesis was that dyslexic children with inhibition deficit guessed more the word they read from the sentence context and the global word form than dyslexic children without inhibition deficit. The results showed that both dyslexics with and without inhibition deficit tended more to guess the words than control children without dyslexia and inhibition difficulties. We discussed these results with the fact that most of children with reading difficulties use the sentence context to compensate for poor reading skills. [less ▲]

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See detailImprovement of Physicians’ Patient-Centeredness: An Empirical Evidence of the Benefits of a Communication Skills Training Program
Jonius, Bénédicte ULg

Poster (2010, May 27)

Objectives. No study has yet assessed the benefits of a communication skills training program on patient-centeredness. The purpose of this study is to assess the association between ... [more ▼]

Objectives. No study has yet assessed the benefits of a communication skills training program on patient-centeredness. The purpose of this study is to assess the association between patients’characteristics and physicians’ communication skills before and after a communication skills training program. Methods. Correlations between physicians’ communication skills and patients’ characteristics were categorized as absent or present: the number of present correlations indicates the level of patientcenteredness. Communication skills were assessed during a consultation before and after a communication skills training program. Consultations were audio-recorded and transcripted. Communication skills were rated according to the Cancer Research Campaign Workshop Evaluation Manual. Patients’ characteristics (sociodemographic, physical and psychological) were measured before and after the training program. Results. Sixty-three physicians were included. Before training, physicians’ communication skills were associated with one patients’ sociodemographic characteristic and with one psychological characteristic. After training, physicians’ communication skills were associated with none of the patients’ sociodemographic characteristics and with four psychological characteristics. Conclusions. This study highlights that physicians’ patient-centeredness may be improved through a communication skills training program. After training, physicians are more centered on patients’ psychological characteristics and not on patients’ sociodemographic characteristics anymore. This study underlines the need to design communication skills training which may further improve patient-centeredness. [less ▲]

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See detail18F labelling of Insulin via click chemistry
Paris, Jérôme ULg; Mercier, Frédéric ULg; Thonon, David ULg et al

Poster (2010, May 27)

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See detailMethylmercury and selenium in vitro effects on harbor seal (Phoca vitulina) lymphocytes : a multidisciplinary approach
Dupont, Aurélie ULg; Bouquegneau, Jean-Marie ULg; Das, Krishna ULg et al

Poster (2010, May 26)

Methylmercury (MeHg) bioaccumulates along the food web, leading to the highest levels in tissues of predatory species. It constitutes the predominant form present in the blood of marine mammals. The blood ... [more ▼]

Methylmercury (MeHg) bioaccumulates along the food web, leading to the highest levels in tissues of predatory species. It constitutes the predominant form present in the blood of marine mammals. The blood cells, including the immune cells, are therefore exposed to the toxic properties of that chemical. Nevertheless, selenium (Se) is an essential element absorbed concomitantly to MeHg which seems to modulate this toxicity. The goal of this study is to evaluate the immunotoxicity of MeHg on the harbor seal (Phoca vitulina) T lymphocytes, highly important in the adaptive immune response, and to investigate the modulating effect of Se on that toxicity. In parallel, the concentrations of MeHg, total mercury (T-Hg) and Se are determined in free-ranging harbour seal blood in order to follow their contamination levels. The T lymphocytes were isolated from the whole blood, exposed to various MeHg and Se concentrations and the exposure effects were estimated by functional tests including the evaluation of viability, proliferation, metabolic activity, DNA and protein synthesis, and by morphological analysis by transmission electron microscopy. The mean T-Hg concentration was 172 ± 143 µg/l of whole blood. The T lymphocytes cultures in vitro displayed a decreasing number of viable cells with increasing concentrations of MeHg, and numerous ultrastructural defects. The cells exposed to MeHg notably displayed distortion of the plasmic membrane, nucleus fragmentations, chromatin compaction, swelling mitochondrias and cytoplasmic vacuolisations. Those results highlighted various immunotoxic effects of MeHg, both at the functional and ultrastructural levels. The antagonistic role of Se on MeHg immunotoxicity is discussed. [less ▲]

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See detailTailor-made polymers by cobalt-mediated radical polymerization
Debuigne, Antoine ULg; Hurtgen, Marie ULg; De Winter, Julien et al

Poster (2010, May 25)

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See detailStimuli-responsive triblock copolymer for biomedical applications
Sibret, Pierre ULg; Croisier, Florence ULg; Zhao, J. et al

Poster (2010, May 25)

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See detailEffects of androgenic and anti-androgenic substances on the freshwater gastropod Lymnaea stagnalis
Giusti, Arnaud ULg; Ducrot, Virginie; Joaquim-Justo, Célia ULg et al

Poster (2010, May 25)

Knowledge on the impacts of endocrine disrupting chemicals (EDCs) on gastropods is scarce and their mechanisms of action are still poorly understood. In this study, effects of 3 androgens (tributyltin ... [more ▼]

Knowledge on the impacts of endocrine disrupting chemicals (EDCs) on gastropods is scarce and their mechanisms of action are still poorly understood. In this study, effects of 3 androgens (tributyltin, testosterone and fenitrothion), 2 anti-androgens (cyproterone acetate and vinclozolin) and 1 estrogen (chlordecone) on growth and reproduction were investigated in the hermaphrodite gastropod Lymnaea stagnalis. [less ▲]

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See detailLe rôle du vagabondage de l’esprit dans le maintien d’un état anxiété
Stawarczyk, David ULg; Blanchy, Sarah ULg; D'Argembeau, Arnaud ULg

Poster (2010, May 25)

Le vagabondage de l’esprit (c’est-à-dire, l’apparition spontanée de pensées prenant leur origine dans la mémoire à long-terme et sans lien avec la tâche en cours de réalisation) est un phénomène fréquent ... [more ▼]

Le vagabondage de l’esprit (c’est-à-dire, l’apparition spontanée de pensées prenant leur origine dans la mémoire à long-terme et sans lien avec la tâche en cours de réalisation) est un phénomène fréquent qui représente en moyenne 10 à 30% de nos pensées journalières. Les recherches dans le domaine suggèrent que ce type de pensées est lié à la gestion de nos préoccupations actuelles et que sa fréquence peut être augmentée par l’induction d’affects négatifs. Cependant, le rôle possible de ces pensées dans le maintien des affects négatifs est encore mal connu. Dans cette étude, une préoccupation anxiogène (supposément devoir réaliser un discours filmé) ou une préoccupation neutre (supposément devoir réaliser une tâche cognitive de réflexion) a été induite immédiatement avant la réalisation d’une tâche exécutive d’inhibition durant laquelle la fréquence et le contenu des pensées distractives ont été évalués. Trois mesures de l’état émotionnel des participants ont été réalisées : (1) au début de la session, (2) après l’induction de la préoccupation et (3) après la tâche exécutive. Les résultats montrent la présence d’un plus grand nombre de pensées distractives liées à la préoccupation induite, d’un plus grand nombre d’erreurs d’inhibition ainsi que d’une augmentation significative des affects négatifs entre les temps 1 et 2 dans la condition anxiogène par rapport à la condition neutre. Par ailleurs, une corrélation négative entre le nombre de pensées distractives liées au discours et la diminution de l’anxiété entre les temps 2 et 3 est observée. Ces résultats démontrent l’importance des cognitions anticipatoires spontanées dans le maintient de l’anxiété. [less ▲]

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See detailImpacts of androgenic and antiandrogenic substances on the freshwater pulmonate gastropod Lymnaea stagnalis
Giusti, Arnaud ULg; Lagadic, Laurent; Joaquim-Justo, Célia ULg et al

Poster (2010, May 23)

Knowledge on the impacts of endocrine disruptors on gastropods is scarce and their mechanism of action poorly understood especially the impacts of androgenic and antiandrogenic compounds. In this study ... [more ▼]

Knowledge on the impacts of endocrine disruptors on gastropods is scarce and their mechanism of action poorly understood especially the impacts of androgenic and antiandrogenic compounds. In this study effects of 5 androgenics and antiandrogenics endocrine disruptors were investigated on the reproduction and life traits of the freshwater pulmonate gastropod Lymnaea stagnalis. The chemicals tested were Tributyltin, Cyproterone acetate, Methyltestosterone, Vinclozolin and Fenitrothion. Tributyltin was used as androgenic positive control. The other compounds tested are androgenic and antiandrogenic compounds either steroids or non steroids. Adult snails were exposed to 3 concentrations of each chemical for 30 days. The size and reproductive organs development were monitored throughout exposure. The number of clutches, the number of eggs per clutch were assessed during the first 10 days. The clutches were kept individually in clear water except for the clutches of the eighth day which were divided in two. Half was kept individually in clear water and the other half was individually reared in contaminated water following the same exposure as their parents. The percentage of hatching per clutch of these clutches was measured. The development size, mortality, and development of reproductive organs of the juveniles were assessed until their first clutch was laid. [less ▲]

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See detailRelationship between BET specific surface area, DR- and t-plot pore volume
Scherdel, C.; Reichenauer, G.; Wiener, M. et al

Poster (2010, May 23)

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See detailImpact of anti-androgens on the production of spermatozoa in Brachionus calyciflorus
Joaquim-Justo, Célia ULg; Cruciani, Valentina ULg; BLASZCZYK, Marie ULg et al

Poster (2010, May 23)

Putative endocrine disruptors affect rate of fertilization of sexual females by males. Preston et al. (2000) reported a decrease in fertilization rate following exposition to, notably, flutamide at 10µg/l ... [more ▼]

Putative endocrine disruptors affect rate of fertilization of sexual females by males. Preston et al. (2000) reported a decrease in fertilization rate following exposition to, notably, flutamide at 10µg/l. We observed similar effects with fenitrothion. Cross mating experiments showed that the decrease in fertilization rate is due to an impact on males exclusively. We studied the impact of anti-androgens on spermatogenesis and observed a decrease in the spermatozoa production with concentrations down to 0,5 mg L-1.We also report a detailed description of the morphology of the male reproductive apparatus in B. calyciflorus based on optic and electronic microscopy analysis and we describe the effect of anti-androgens on males and spermatogenesis in males. [less ▲]

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See detailLes enzymes et leur utilisation en biotechnologie industrielle
Galonde, Nadine ULg

Poster (2010, May 22)

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See detailComplementation of Saccharomyces cerevisiae mutants using a soil metatranscriptomic library
Kellner, Harald ULg; Luis, Patricia; Portetelle, Daniel ULg et al

Poster (2010, May 21)

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See detailmiR-146a: an anti-angiogenic miRNA regulated by NF-kB
Halkein, Julie ULg; Tabruyn, Sébastien ULg; Malvaux, Ludovic et al

Poster (2010, May 21)

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See detail16K human prolactin is an anti-lymphangiogenic factor in vitro and in vivo
Kinet, Virginie; Castermans, Karolien; Blacher, Silvia ULg et al

Poster (2010, May 21)

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See detailInvolvement of miR-125b in in vitro and in vivo angiogenesis
Malvaux, Ludovic; Pendeville, Hélène; Sabatel, Céline et al

Poster (2010, May 21)

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See detailEtude du mode de liaison des canaux potassiques de type SK et l’apamine par modélisation moléculaire
Dilly, Sébastien ULg; Lamy, Cédric; Seutin, Vincent ULg et al

Poster (2010, May 20)

Parmi les canaux ioniques impliqués dans le contrôle de l'activité neuronale, les canaux potassiques calcium-dépendants de basse conductance, dénommés canaux SK, constituent une cible thérapeutique ... [more ▼]

Parmi les canaux ioniques impliqués dans le contrôle de l'activité neuronale, les canaux potassiques calcium-dépendants de basse conductance, dénommés canaux SK, constituent une cible thérapeutique intéressante. En effet, ils sous-tendent la posthyperpolarisation ("AfterHyperPolarization") de durée moyenne (mAHP) qui limite l'excitabilité de divers types de neurones du système nerveux central (SNC). A ce jour, 3 types de sous-unités, SK1, SK2 et SK3, ont été identifiés dans différentes régions du cerveau. Le blocage sélectif de ces canaux pourrait être bénéfique dans le traitement de divers troubles du SNC comme la maladie de Parkinson (SK3), la dépression (SK3) ou encore les désordres cognitifs (SK2) (Liégeois et al., 2003 ; Pedarzani et al., 2008). Jusqu’à présent, le site d’interaction entre les canaux SK et leurs bloqueurs n’a pas encore été précisément élucidé. Dans ce contexte, nous avons entrepris la modélisation de ces canaux par homologie comparative en se basant sur la structure cristalline du canal potassique KCSA (Doyle et al., 1998). La construction de ces canaux constitue la première étape dans la détermination des requis structuraux essentiels à l’affinité de bloqueurs et à la compréhension des modes de liaison de ces ligands. Le mode de liaison de l’apamine, bloqueur peptidique issu du venin d’abeille, a été ensuite exploré par « docking ». Afin de confirmer ce site de liaison potentiel, des expériences de mutagénèse dirigée ont été réalisées. Les premiers canaux mutants testés dans des expériences électrophysiologiques par la technique de « patch clamp » ont permis de valider certaines données théoriques. Grâce à cette stratégie, nous espérons préciser le mécanisme d'action des bloqueurs des canaux SK et, idéalement, découvrir des pistes pour concevoir des bloqueurs sélectifs. [less ▲]

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See detailDe la prévention chronologique à la prévention relationnelle; la prévention quaternaire comme tâche du médecin de famille.
Jamoulle, Marc ULg

Poster (2010, May 19)

La prévention clinique est traditionnellement exprimée comme une vue du médecin sur une tâche à réaliser avant la survenue d’un évènement. Initiée par Leavell et Clark en 1958 elle est complétée en 1988 ... [more ▼]

La prévention clinique est traditionnellement exprimée comme une vue du médecin sur une tâche à réaliser avant la survenue d’un évènement. Initiée par Leavell et Clark en 1958 elle est complétée en 1988 par J-A Bury qui dénomme prévention quaternaire les soins palliatifs.Le paradigme change, le patient devient central aux soins, la prévention clinique est perçue au travers de la relation entre le médecin et le patient. Le croisement de la science du médecin et de la conscience du patient permet de répartir la prévention en quatre champs. Elle est traversée en oblique par la ligne du temps. Cette proposition (Jamoulle, 1986) a été avalisée par la Wonca et l’UEMO et permet de cadrer quatre concepts de prévention clinique. [less ▲]

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See detailBiological control using Episyrphus balteatus (De Geer) (Diptera: Syrphidae)
Leroy, Pascal ULg; Verheggen, François ULg; Capella, Quentin et al

Poster (2010, May 18)

Augmentative biocontrol constitutes a safe way to reduce pest populations through the enhancement of natural enemies’ activity. In this context, the aphidophagous syrphid Episyrphus baltetaus (De Geer ... [more ▼]

Augmentative biocontrol constitutes a safe way to reduce pest populations through the enhancement of natural enemies’ activity. In this context, the aphidophagous syrphid Episyrphus baltetaus (De Geer) (Diptera: Syrphidae) is a promising candidate for aphid biological control: larvae of this syrphid attack and consume a wide range of aphid species and are found on many vegetable crops. Because natural populations of beneficials are not always sufficient to regulate the pest infestations, this work has focused on the conception of a biological control device containing syrphid eggs which can easily be introduced in fields or greenhouses. Using semiochemicals [E-(β)-farnesene, R-(+)-limonene and (Z)-3-hexenol], honeydews and “artificial honeydews” (10% or 30% aqueous solutions of sucrose, fructose and glucose), the syrphid oviposition was artificially induced on an inert surface. To test and validate the biological control device described above, laboratory and field experiments were performed: a plastic lamella covered with syrphid eggs was suspended on aphid infested plants in order to measure the efficiency of the device. The results obtained were promising since populations of 500 aphids were eliminated in ten days when 15 syrphid eggs were introduced. The use of such a biological control device could certainly contribute to aphid biological control strategies. [less ▲]

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See detailA Far-UV Imager for the Jupiter Ganymede Orbiter
Bunce, E. J.; Molyneux, P.; Bannister, N. et al

Poster (2010, May 17)

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See detailL'inventaire du bois mort à terre
Ligot, Gauthier ULg; Rondeux, Jacques ULg

Poster (2010, May 12)

Le bois mort à terre est devenu un indicateur reconnu de la biodiversité et de la gestion durable des forêts. Il importe donc de pouvoir apprécier les quantités de mort à l'hectare. Choisir la méthode d ... [more ▼]

Le bois mort à terre est devenu un indicateur reconnu de la biodiversité et de la gestion durable des forêts. Il importe donc de pouvoir apprécier les quantités de mort à l'hectare. Choisir la méthode d'échantillonnage à utiliser reste une tâche ardue bien qu'il existe une abondante littérature sur le sujet. Ce poster compare deux techniques généralement utilisées : les placettes de taille fixe et les transects. Nous avons évalué ces deux méthodes aussi bien à l'échelle locale que nationale et au travers de simulations statistiques nous en avons évalué la précision et l'efficacité. De plus, nous mettons en évidence l'importance d'utiliser des fonctions de conversion des estimations obtenues dans un but d'harmonisation internationale des résultats. [less ▲]

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See detailTypologie des chênaies de la Région wallonne
Perin, Jérôme ULg; Brostaux, Yves ULg; Claessens, Hugues ULg

Poster (2010, May 12)

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See detailAvifaune forestière - Etude d'habitat du Pic mar
Lehaire, François ULg; Paquet, Jean-Yves; Delahaye, Laurence et al

Poster (2010, May 12)

En tant que bio-indicateurs, les espèces spécialistes des grands massifs forestiers feuillus ont un intérêt pour l'étude et le suivi de la diversité de ces milieux.

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See detailL'inventaire forestier national permanent du Grand-Duché de Luxembourg, aide au monitoring de la biodiversité
Alderweireld, Matthieu ULg; Kugener, Georges; Wagner, Marc et al

Poster (2010, May 12)

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See detailL'inventaire forestier national permanent du Grand-Duché de Luxembourg, aperçu de la méthodologie
Alderweireld, Matthieu ULg; Kugener, Georges; Wagner, Marc et al

Poster (2010, May 12)

L'inventaire forestier national du Grand-Duché de Luxembourg assure depuis 1998 la mesure par échantillonnage des 89 000 ha de forêt que compte le pays. La collecte des données s'étale sur 3 ans et est ... [more ▼]

L'inventaire forestier national du Grand-Duché de Luxembourg assure depuis 1998 la mesure par échantillonnage des 89 000 ha de forêt que compte le pays. La collecte des données s'étale sur 3 ans et est réalisée tous les 10 ans au niveau d'unités d'échantillonnage à placettes concentriques. Ces données concernent tous les aspects de la forêt dans l'esprit de multifonctionnalité qui lui est assigné. [less ▲]

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See detailSTEM CELL IN THE TREATMENT OF TENDONITIS IN EQUINE PATIENTS
Verwilghen, Denis ULg; Briquet, Alexandra ULg; Gothot, André ULg et al

Poster (2010, May 07)

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See detailInfluence Des Conditions Extérieures Sur Le Comportement Au Séchage d'un Milieu Poreux
Kahlerras, Loubna ULg; Belhamri, Azeddine

Poster (2010, May 07)

Ce travail se propose d’analyser les phénomènes du séchage convectif d’un milieu poreux non saturé. Le modèle de calcul considère le couplage des équations de la couche limite et celles qui décrivent le ... [more ▼]

Ce travail se propose d’analyser les phénomènes du séchage convectif d’un milieu poreux non saturé. Le modèle de calcul considère le couplage des équations de la couche limite et celles qui décrivent le transfert de chaleur et de masse dans un milieu poreux, ayant les caractéristiques du béton renforcé avec des coupeaux de bois. La simulation effectuée montre l’effet de certains paramètres pertinents du matériau comme la température initiale et l’humidité initiale, sur le processus du séchage [less ▲]

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See detailRisk assessment of soil compaction in Walloon Region (Belgium)
Rosiere, Charlotte ULg; Delvoie, Simon ULg; Charlier, Robert ULg et al

Poster (2010, May 07)

The proposed Soil Framework Directive COM(2006)232 requires Member States to identify areas at risk of erosion, decline in organic matter, salinisation, compaction, sealing and landslides, as well as to ... [more ▼]

The proposed Soil Framework Directive COM(2006)232 requires Member States to identify areas at risk of erosion, decline in organic matter, salinisation, compaction, sealing and landslides, as well as to set up an inventory of contaminated sites. The present project aims to identify the susceptibility to compaction of soils of the Walloon Region (Belgium) and to recommend good farming practices avoiding soil compaction as far as possible. Within this scope, the concept of precompression stress (Pc) (Horn and Fleige, 2003) was used. Pc is defined as the maximum major principal stress that a soil horizon can withstand against any applied external vertical stress. If applied stress is higher than Pc, the soil enters in a plastic state, not easily reversible. For a given soil, the intensity of soil compaction is mainly due to the applied load which depends on vehicle characteristics (axle load, tyre dimensions, tyre inflation pressure, and vehicle velocity). To determine soil precompression stress, pedotransfert functions of Lebert and Horn (1991) defined at two water suctions (pF 1.8 and 2.5) were used. Parameters required by these functions were found within several databases (Aardewerk and Digital Map of Walloon Soils) and literature. The validation of Pc was performed by measuring stress-strain relationships using automatic oedometers. Stresses of 15.6, 31, 3, 62.5, 125, 250, 500 and 1000 kPa were applied for 10 min each. In this study, the compaction due to beet harvesters was considered because the axle load can exceed 10 tons and these machines are often used during wet conditions. The compaction at two depth levels was considered: 30 and 50 cm. Compaction of topsoil was not taken into account because, under conventional tillage, the plough depth is lower than 25 cm. Before and after the passage of the machines, following measurements were performed: granulometry, density, soil moisture, pF curve, Atterberg limits, ... The software Soilflex (Keller et al., 2007) was used to estimate the distribution of the vertical stresses sigma z in the soil. Comparison was performed between sigma z and Pc. The following data simulated the passage of a beet harvester machine (mass: 23 580 kg; load: 18 000 kg) in a silty soil located in Hesbaye and classified as Aba (Sirjacobs et al., 2000). The passage of the machine would create a Pc of around 100 kPa at 30 cm depth, while the stress induced by the machine would reach 240 kPa. In the field borders, where more vehicle traffic was usually observed and where the soil was over consolidated, Pc would reach 180 kPa, while sigma z would be 220 kPa. In both cases, the risk of compaction created by the passage of the machine would be high. [less ▲]

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See detailPaleoproductivity and carbon cycling during the Middle Miocene Monterey Excursion
Billups, Katarina; Diester-Haass, Liselotte; Emeis, Kay-Christian et al

Poster (2010, May 06)

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See detailOn the local operational geomagnetic index K calculation
Stankov, Stan; Stegen, Koen; Wautelet, Gilles ULg et al

Poster (2010, May 06)

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See detailMonitoring a shallow geothermal experiment in a sandy aquifer using electrical resistivity tomography: a feasibility study
Hermans, Thomas ULg; Vandenbohede, Alexander; Nguyen, Frédéric ULg et al

Poster (2010, May 06)

Geothermal resources, especially groundwater resources, are increasingly used around the world. It is therefore necessary to improve the characterisation of thermal parameters of the aquifers. This is ... [more ▼]

Geothermal resources, especially groundwater resources, are increasingly used around the world. It is therefore necessary to improve the characterisation of thermal parameters of the aquifers. This is done mostly with thermal response tests. In this work, we monitored with electrical resistivity tomography a geothermal test on the campus of Ghent University (Belgium). We injected warm water (45°C) into a sandy aquifer where the groundwater has a temperature of 10°C at a rate of 100 liter/hour during three days. Laboratory measurements indicated that we could expect at most a change of 2%/°C of the water electrical conductivity. The time-lapse series of electrical images show clearly the thermal plume corresponding to the injected water with a maximum change of minus 20% after 72 hours of injection. A comparison with a geothermal model shows that the anomaly is well detected but also distorded due to the inversion regularization (smoothness constraint). ERT enabled to follow the evolution of the injected heated water with more spatial coverage that traditionnal techniques. ERT is thus an interesting tool to monitor the exploitation of geothermal resources. In the future, it will be necessary to improve the inversion process to use quantitavely such results in a calibration process. [less ▲]

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See detailOptimisation of slow-release formulations as biological control devices
Heuskin, Stéphanie ULg; Lorge, Stéphanie; Debatty-Mestdagh, Michelle et al

Poster (2010, May 05)

E-β-Farnesene, the alarm pheromone of many aphid species and β-caryophyllene, recently identified as one of the possible component of the aggregation pheromones of the Asian ladybeetles Harmonia axyridis ... [more ▼]

E-β-Farnesene, the alarm pheromone of many aphid species and β-caryophyllene, recently identified as one of the possible component of the aggregation pheromones of the Asian ladybeetles Harmonia axyridis Pallas, are considered as two sesquiterpenes attractive for aphids’ predators and parasitoids, Epysirphus balteatus De Geer and Aphidius ervi Haliday, respectively. In the present research, alginate gel beads formulations were optimised as semiochemical slow-release devices. The formulations were evaluated in terms of volatiles release capacity, protection efficiency of sesquiterpenes against oxidation, and biological activity towards Epysirphus balteatus and Aphidius ervi. Moreover, the sesquiterpenes used in the formulations were obtained from natural matrices. Indeed, they were purified by flash chromatography fractionation of essential oils of Matricaria chamomilla L. and Nepeta cataria L., for obtaining E-β-farnesene and β-caryophyllene, respectively. The purities of the fractions were determined by means of a fast GC analytical method optimised for a good resolution of terpenes in less than five minutes. The experiments can conclude that the alginate gel beads formulations are efficient as biological control devices considering the results obtained with the various biological tests led on predators and parasitoids. Moreover, the sesquiterpenes are more protected when formulated in alginate beads than without formulation. The devices allow also a slow-release of semiochemicals during a long time (at least 40 days) depending on physico-chemical parameters (temperature, relative humidity). A mathematical modelisation of semiochemicals release is presently in study. [less ▲]

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See detailDesign of a decision tool for hydromorphological restoration of water bodies in Walloon Region
Peeters, Alexandre ULg; Hallot, Eric ULg; Verniers, Gisèle et al

Poster (2010, May 05)

The pilot project WALPHY (LIFE + Environment LIFE07 ENV/B/000038, UE-funded) develops a structured approach aiming at improving hydromorphological quality of the upstream Meuse basin in order to achieve ... [more ▼]

The pilot project WALPHY (LIFE + Environment LIFE07 ENV/B/000038, UE-funded) develops a structured approach aiming at improving hydromorphological quality of the upstream Meuse basin in order to achieve the “good ecological status” required by the Water Framework Directive (WFD 2000/60). It began in January 2009 for a period of 5 years. River’s biological recovery needs the recovery of river’s structure and physical dynamics. Returning to "good ecological status" inevitably involves physical restoration of affected rivers. Physical component of aquatic environment acts as a limiting factor for their functioning. Three types of modification are key obstacles for river good ecological status: (i) fluxes alteration (discharge, sedimentation. . . ), (ii) forms alteration (uniform facies. . . ) and (iii) biotopes access alteration (lateral connections breaks, modification of the continuity upstream/ downstream. . . ). Therefore hydromorphology is needed to implement the WFD. To respond to this legal necessity, we develop a unique, useful and suitable methodology in Walloon Region to determine and schedule river physical quality restoration works. This methodology has been applied on 3 “risk water bodies”. The works are based on two axes : longitudinal continuity and transversal continuity. The two first selected water bodies (Bocq river, eastern tributary of the Meuse) seem to be convenient for the restoration works which concern the longitudinal continuity due to the presence of dams and other obstacles usually between 1 and 3 m high. These works consist in dam management (weir removal or fish passage) taking into account hydromorphological (bedload transport) and biological (invertebrate or fish species free movement) impacts. The third water bodies (Eau Blanche river, western tributary of the Meuse) presents straightened rivers with artificial banks, witch consequently own bad connections between the stream and its floodplain. This water bodies should therefore be appropriated for the works based on the transversal continuity recovery. They consist in enhancing straightened river channels, restoring meanders or bank restoration. The first river restoration works will take place from summer 2010. A monitoring has already been undertaken to draw up the situation before the restoration works, witch will be able to compare to the situations during and after works. In addition, a natural site has been chosen to enable any comparison with the intervention sites. The geomorphological monitoring is based on physical and sedimentological parameters (substrate cartography, velocity measures, stream channel DEM, topography and sedimentological index). The ecological monitoring consists in analysing the physical and chemical parameters (turbidity, suspended sediment load). It also analyses the biological quality through 3 indicators: macrophytes, macroinvertebrates and fishes. Among other, a microhabitats method has been improved and applied on 3 intervention sites and 1 natural site. The microhabitats cartography results from both the flow velocity cartography and the substrate cartography. With this method, the physical quality of each intervention site could be compared with the natural site and above all with the future situation. Our method is also useful to inventory precisely invertebrates and to characterise fish habitats. [less ▲]

Detailed reference viewed: 33 (8 ULg)
See detailEvolution of Harmonia axyridis (Pallas) alkaloid protection during the year
Fischer, Christophe ULg; Sibret, Virginie; Laurent, Pascal ULg et al

Poster (2010, May 05)

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See detailBiological control device using the aphidophagous hoverfly Episyrphus balteatus (De Geer) (Diptera: Syrphidae)
Leroy, Pascal ULg; Verheggen, François ULg; Francis, Frédéric ULg et al

Poster (2010, May 05)

Augmentative biocontrol constitutes a safe way to reduce pest populations through the enhancement of natural enemies’ activity. In this context, the aphidophagous syrphid Episyrphus baltetaus (De Geer ... [more ▼]

Augmentative biocontrol constitutes a safe way to reduce pest populations through the enhancement of natural enemies’ activity. In this context, the aphidophagous syrphid Episyrphus baltetaus (De Geer) (Diptera: Syrphidae) is a promising candidate for aphid biological control: larvae of this syrphid attack and consume a wide range of aphid species and are found on many vegetable crops. Because natural populations of beneficials are not always sufficient to regulate the pest infestations, this work has focused on the conception of a biological control device containing syrphid eggs which can easily be introduced in fields or greenhouses. To test and validate the biological control device described above, laboratory and field experiments were performed: a plastic lamella covered with syrphid eggs was suspended on aphid infested plants in order to measure the efficiency of the device. The results obtained were promising since populations of 500 aphids were eliminated in ten days when 15 syrphid eggs were introduced. The use of such a biological control device could certainly contribute to aphid biological control strategies. [less ▲]

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See detailParticularities of Aphidius ervi embryo development and main limitations of its in vitro culture
Sabri, Ahmed ULg; Leroy, Pascal ULg; Hance, Thierry et al

Poster (2010, May 05)

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See detailLong term carbon dioxide exchange above a mixed forest in the Belgian Ardennes: evaluation of different approaches to deduce total ecosystem respiration from Eddy covariance measurements
Jerome, Elisabeth ULg; Heinesch, Bernard ULg; Aubinet, Marc ULg

Poster (2010, May 05)

The general aim of this research is to analyze inter annual variability of carbon dioxide (CO2) fluxes exchanged by a mixed forest located at the Vielsalm experimental site in Belgium. At this site, CO2 ... [more ▼]

The general aim of this research is to analyze inter annual variability of carbon dioxide (CO2) fluxes exchanged by a mixed forest located at the Vielsalm experimental site in Belgium. At this site, CO2 flux measurements started in 1996 and are still going on. Thirteen complete years of measurements are thus available. Net Ecosystem Exchange (NEE) inter annual variability may be driven by gross primary productivity (GPP) or Total Ecosystem Respiration (TER), which should thus be both quantified. Using flux partitioning methods, TER is deduced from NEE measurements. GPP is then obtained by subtracting TER from NEE. Initially, a robust estimation of TER is required. This work seeks to compare two independent approaches to assess TER in order to quantify the implications on inter-annual variability. The comparison was performed on twelve complete years. TER estimates can be deduced by extrapolating to the whole day NEE measurements taken during selected night or day periods. In both case, the extrapolation is performed by using a respiration response to temperature. The first approach, referred as the night-time approach, consisted in calculating TER using a temperature response function derived from night-time data sets (Reichstein et al., 2005). The second approach, referred as the daytime approach, consisted in assessing TER from the intercept of the NEE/Photosynthetically Photon Flux Density (PPFD) response (Wohlfahrt et al., 2005). For each approach, different modalities were compared: the use of long term (annual) or short term (15 days) data sets for the night-time approach and the use of different types of regression for the daytime approach. In addition, the impact of the temperature choice was studied for each of the approaches. For the night-time approach, main results showed that air temperature sensitivity of ecosystem respiration derived from annual data did not reflect the short-term air temperature sensitivity. Vielsalm is a summer active ecosystem (annual temperature sensitivity larger than short-term temperature sensitivity). Results suggested also that, for both approaches, regressions based on soil temperature gave more robust results than those based on air temperature. Furthermore, the comparison showed that the night-time and the daytime approaches give disagreeing pictures of TER inter annual variability which suggested that the choice of the approach is critical in order to correctly depict TER inter annual variability. Finally, at this stage, TER inter annual variability cannot be explained by variability of climatic conditions. [less ▲]

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See detailPheromone variability and evolution in the butterfly genus Bicyclus, and implication in its diversification
Bacquet, Paul; Brattström, O.; Brakefield, P. M. et al

Poster (2010, May 05)

The evolution of olfactive communication in generating reproductive isolation among species remains poorly understood (Smadja & Butlin 2009). In Lepidoptera, studies have mainly focused on long-distance ... [more ▼]

The evolution of olfactive communication in generating reproductive isolation among species remains poorly understood (Smadja & Butlin 2009). In Lepidoptera, studies have mainly focused on long-distance pheromones produced by moths. Moth sex pheromones have been shown to display inter-population variation (e.g. Tòth et al. 1992, McElfresh & Millar 2008 and ref. within, Groot et al. 2009) and to be involved in interspecific isolation (e.g. Löfstedt et al. 1991, Groot et al. 2006). In butterflies, the few existing studies on sex pheromones have mainly focused on the identification of the male specific compounds and the demonstration of their behavioural activity in courtship (e.g. Grula et al. 1980, Nieberding et al. 2008, Yildizhan et al. 2009), but have failed so far to highlight a role in reproductive isolation (Friberg et al. 2008). In the species-rich Bicyclus genus Kirby, 1871 (Nymphalidae, Satyrinae) the structures producing the pheromones, i.e. the androconia, are key characters to discriminate among species (Condamin 1973). In B. anynana (Butler, 1879), the male sex pheromone (MSP) has been shown to play a role in mate choice (Costanzo & Monteiro 2007, Nieberding et al. 2008), to be heritable, and particular ratios of the pheromone components are under strong sexual selection (Nieberding et al, unpubl. data). Therefore, we expect that pheromone evolution is responsible for reproductive isolation and diversification in this butterfly group. In this framework, our research project aims at understanding the evolution of MSP at the interspecific level across the Bicyclus genus and specifically at testing their potential role in the speciation process. Potential MSP of several species across the Bicyclus genus have been identified by gas chromatography and mass spectrometry. Observed differences in pheromone composition between species are compared in a phylogenetic framework to the molecular tree of the species (following Oliver et al. 2009). We expect the evolutionary rate of MSP to be unlinked to the molecular tree if MSP are under sexual selection across the genus (i.e. saltational evolution following Symonds & Elgar 2004, Shirangi et al. 2009). Moreover, if MSP generated reproductive isolation between species in a “reinforcement” process, we expect higher differences of MSP composition between sympatric species than between allopatric species and an increase of this pattern for younger species compared to older species (Lukhtanov et al. 2006). [less ▲]

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See detailEffect of host plants on the abundance of Aphis craccivora Koch (Homoptera : Aphididae) and it parasitism by three parasitoids (Hymenoptera: Braconidae, Pteromalidae, Encyrtidae, ) in green space of Université des Sciences et Techniques de Masuku(USTM, Franceville), Gabon
Poligui, René Noël ULg; Francis, Frédéric ULg; Haubruge, Eric ULg et al

Poster (2010, May 05)

The cow pea aphid, Aphis craccivora Koch were studied on tree wield weeds of lawn (Paspalum sp, Poaceae), Chrysopogon aciculatus (Retz.) Trin. (Poaceae), Sporobolus indicus (L.) R.Br. (Poaceae) and ... [more ▼]

The cow pea aphid, Aphis craccivora Koch were studied on tree wield weeds of lawn (Paspalum sp, Poaceae), Chrysopogon aciculatus (Retz.) Trin. (Poaceae), Sporobolus indicus (L.) R.Br. (Poaceae) and Brachiara decumbens Stapf (Poaceae). 120 infloscences of each host plant specie were examined. The hymenopteran parasitism was based on mummified aphids. In the ascending order of infestation, A.craccivora colonies were less abundant on S.indicus (192 aphids), abundant on C.aciculatus (1546) and highly abundant on B.decumbens (2986). Parasitism on aphids is very low on B.decumbens (7,57%), high on C.aciculatus(57,12%) and very high on S.indicus (82,05%). 410 hymenopteran parasitoids hatch from 500 mummufied aphids taken on S.indicus, for 153 Aphidius sp(Braconidae) individuals ,160 (39,02%) Ceroplastes sp (Pteromalidae) and 97(23, 66%) non identified encyrtid(encyrtidae). Aphidophagous larva of Cheilomenes sulfurea (Coccinelidae) and Platynaspsis capicola Crotch (Coccinellidae) were observed predatoring aphids respectively on C.aciculatus and S.indicus.This study highlight the presence of native beneficials that can be used as biological control agents. [less ▲]

Detailed reference viewed: 65 (1 ULg)
See detailNeural correlates of cognitive control at the item specific level in the Stroop task
Grandjean, Julien ULg; D'Ostilio, Kevin ULg; Fias, Wim et al

Poster (2010, May 04)

Detailed reference viewed: 11 (4 ULg)