Last 7 days
Bookmark and Share    
Full Text
Peer Reviewed
See detailProbing the conformational changes during desolvation of ions using orthogonal mobility methods (CE-IMS)
Far, Johann ULg; Kune, Christopher ULg; Delvaux, Cédric ULg et al

Poster (2014, April 08)

The transfer of ions from the solution to the gas phase is a critical step to produce « native species ». Coming from a highly solvating medium, ionic species will tend to find a new equilibrium ... [more ▼]

The transfer of ions from the solution to the gas phase is a critical step to produce « native species ». Coming from a highly solvating medium, ionic species will tend to find a new equilibrium conformation in the gas phase. The pathway to reach the thermodynamically stable conformation involves crossing potential barriers of different heights. When these barriers are too high compared to the internal energy of the ions, it will result in “partial memories” (as structural preservation) of the conformation in solution. In order to evaluate the effect of the solvent evaporation and of the various collision processes encountered by the ions in the mass spectrometer. The strategy consists in comparing in a single experiment the shape of the ions in solution and in the gas phase. Data are obtained by coupling capillary electrophoresis with Ion Mobility Mass Spectrometry. Drift times in solution and in the gas phase are directly compared. Deviations from their correlation points out changes in folding upon desolvatation. Preliminary results show that among peptides issued from tryptic digest of BSA some of them clearly change their conformation during desolvatation. This work intends to evaluate the extent of conformational “memory” of the ions of different nature for best experimental condition allowing “native mass spectrometry”. [less ▲]

Detailed reference viewed: 27 (10 ULg)
Full Text
See detailLe Parti Socialiste en 2014: un programme électoral en rupture avec les précédents ?
Piet, Grégory ULg; Dandoy, Régis

E-print/Working paper (2014)

Detailed reference viewed: 12 (1 ULg)
See detailAu delà des octonions
Kreusch, Marie ULg

Scientific conference (2014, April 08)

Une nouvelle série d'algèbres réelles généralisant l'algèbre des octonions, tout comme les algèbres de Clifford prolongent l'algèbre des quaternions, a été introduite par Morier-Genoud et Ovsienko en 2011 ... [more ▼]

Une nouvelle série d'algèbres réelles généralisant l'algèbre des octonions, tout comme les algèbres de Clifford prolongent l'algèbre des quaternions, a été introduite par Morier-Genoud et Ovsienko en 2011. Ces algèbres, qui ne sont ni commutative, ni associative, peuvent être vues comme des algèbres twistées sur le groupe Z_2^n avec une fonction de twist cubique. Une classification de ces algèbres, semblable à la classification des algèbres de Clifford, sera exposée. De plus, celle-ci donnera lieu à une discussion sur les fonctions cubiques définies sur Z_2^n à valeurs dans Z_2. [less ▲]

Detailed reference viewed: 11 (3 ULg)
Full Text
See detailSIMMEM comme outil d'aide à la gestion : exemple d'application à une forêt communale en Ardenne belge
Dedry, Laurent ULg; Perin, Jérôme ULg; De Thier, Olivier ULg et al

Scientific conference (2014, April 08)

SIMMEM est un module informatique intégré à CAPSIS permettant de simuler l'évolution des forêts sur des périodes allant jusqu'à plusieurs dizaines d'années

Detailed reference viewed: 23 (15 ULg)
Peer Reviewed
See detailMultitasking capacities in persons diagnosed with schizophrenia: A preliminary examination of their neurocognitive underpinnings and ability to predict real world functioning
Laloyaux, Julien ULg; Van der Linden, Martial ULg; Levaux, Marie-Noëlle ULg et al

Poster (2014, April 08)

Background: Difficulties in everyday life activities are core features of persons diagnosed with schizophrenia. Moreover, patients seem to demonstrate particular difficulties during complex and ... [more ▼]

Background: Difficulties in everyday life activities are core features of persons diagnosed with schizophrenia. Moreover, patients seem to demonstrate particular difficulties during complex and multitasking activities, such as cooking a meal (Semkovska et al., 2004). Multitasking refers to activities where the person has to: carry out and alternate between different tasks that vary in terms of priority, difficulty and duration; define the tasks’ targets; and where the person is faced with unexpected problems during the realization of these tasks (Burgess, 2000). However, at present, patients’ multitasking capacities have not been adequately examined in the literature due to an absence of suitable assessment strategies. We thus recently developed a computerized real-life activity task designed to take into account the complex and multitasking nature of certain everyday life activities where participants are required to prepare a room for a meeting – the Computerized Meeting Preparation Task (CMPT) Methods: Twenty-one individuals diagnosed with schizophrenia and 20 matched healthy controls completed the CMPT. During the CMPT, participants found themselves in a virtual room that they had to prepare for a meeting while respecting a list of instructions (the placement of the guests, the needed objects, the desired drinks, etc.). Patients were also evaluated with an extensive cognitive battery (assessing executive functions, attention, processing speed and memory), measures of symptomatology and real world functioning. To examine the ecological validity of the CMPT, 14 others patients were recruited and were given the computerized version and a real version of the meeting preparation task. Results: Results demonstrated that performance on the CMPT significantly differentiated patients and healthy controls for the total time to complete task, planning efficiency, and the respect of the instructions. Moreover, these variables were significantly correlated with executive functioning (i.e. cognitive flexibility and planning), suggesting the major implication of these cognitive processes in multitasking activities. Performance on the CMPT also significantly predicted up to 50% of real world functioning. Finally, performances on the computerized version and the real version of the meeting preparation task were highly correlated, suggesting good ecological validity. Discussion: In this study, we created a novel task involving the multitasking nature of real world activities. The results demonstrated that this approach provides a good indication of the real world functioning in patients diagnosed with schizophrenia. Moreover, results suggest a particular implication of executive functioning in multitasking activities. These findings suggest the importance of evaluating multitasking capacities in patients diagnosed with schizophrenia in order to predict real world functioning. [less ▲]

Detailed reference viewed: 15 (1 ULg)
Full Text
See detailEnzymatic process for the fractionation of baker's yeast cell wall (saccharomyces cerevisiae)
Borchani, Chema; Fonteyn, Fabienne; Jamin, Guilhem et al

Conference (2014, April 07)

Detailed reference viewed: 7 (0 ULg)
Full Text
See detailCaractérisation de la sève du palmier dattier
Makhlouf-Gafsi, Inès; Mokni-Ghribi, Abir; Attia, Hammadi et al

Conference (2014, April 07)

Detailed reference viewed: 5 (0 ULg)
Full Text
See detailFonctionnalisation des matières grasses alimentaires
Danthine, Sabine ULg; Blecker, Christophe ULg

Conference (2014, April 07)

Detailed reference viewed: 13 (0 ULg)
Full Text
See detailEffet des conditions d'extraction sur la composition et les activités antioxydantes des ulvanes de l'algue Ulva lactucas
Yaich, Hela; Garna, Haikel; Paquot, Michel ULg et al

Conference (2014, April 07)

Detailed reference viewed: 13 (0 ULg)
Full Text
Peer Reviewed
See detailEfficacité des interven8ons langagières basées sur la guidance parentale : qu’en est- il pour les popula8ons de faible statut socio-économique (SSE)?
Maillart, Christelle ULg; Martinez Perez, Trecy ULg; Jidovtseff, Boris ULg et al

Poster (2014, April 07)

Le développement langagier de l’enfant est fortement influencé par le statut socio-économique (SSE). Dès le plus jeune âge, les enfants issus de milieux défavorisés présentent un retard langagier ... [more ▼]

Le développement langagier de l’enfant est fortement influencé par le statut socio-économique (SSE). Dès le plus jeune âge, les enfants issus de milieux défavorisés présentent un retard langagier objectivable (Hoff, 2012). La qualité et la quantité du langage adressé à l’enfant sont des variables médiatrices dans l’impact du SSE (Hoff, 2003). Une méta-analyse a mis en évidence l’efficacité des interventions langagières ciblées sur l’enrichissement du langage adressé à l’enfant (Robert & Kaiser, 2011). Toutefois, les études d’intervention ont principalement porté sur des enfants issus de SSE moyen : il est difficile d’en généraliser la portée aux populations plus défavorisées. Cette étude randomisée contrôlée évalue l’efficacité d’une intervention ciblée sur le langage adressé à l’enfant dans des populations de faible SSE. Participants Quatre-vingt-seize enfants âgés de 18 à 30 mois et de faible SSE ont été recrutés au sein de 10 consultations enfants organisées par l’Office de la Naissance et de l’Enfance, en Belgique. Dans 5 de ces 10 consultations, une intervention portant sur la stimulation langagière a été proposée. Dans les 5 autres, une intervention en psychomotricité a été mise en place. Les deux interventions se déroulent en groupe (une dizaine d’enfants et leur parent) et sont appariées en termes de fréquence (1 heure par semaine) et de durée (15 semaines). Une évaluation individuelle a été proposée avant l’intervention (T1), après l’intervention (T2) et 6 mois après la fin de l’intervention (T3). Chaque testing évaluait les développements cognitif, langagier et psychomoteur de l’enfant et comportait une interaction filmée parent-enfant en situation de jeu afin d’analyser le langage adressé à l’enfant et les comportements parentaux. Principaux résultats Les résultats mettent en évidence l’efficacité et la spécificité de l’intervention langagière proposée, tant au niveau du langage des enfants que des modifications du comportement parental. [less ▲]

Detailed reference viewed: 17 (2 ULg)
See detailLe jeu vidéo amateur : un angle mort des game studies ?
Hurel, Pierre-Yves ULg

Conference (2014, April 07)

Detailed reference viewed: 9 (0 ULg)
Full Text
See detailMultivariate coefficients of variation: comparison and influence functions
Aerts, Stéphanie ULg; Haesbroeck, Gentiane ULg; Ruwet, Christel ULg

E-print/Working paper (2014)

In the univariate setting, coefficients of variation are well known and used to compare the variability of populations characterized by variables expressed in different units or having really different ... [more ▼]

In the univariate setting, coefficients of variation are well known and used to compare the variability of populations characterized by variables expressed in different units or having really different means. When dealing with more than one variable, the use of such a relative dispersion measure is much less common even though several generalizations of the coefficient of variation to the multivariate setting have been introduced in the literature. In this paper, the lack of robustness of the sample versions of the multivariate CV's is illustrated by means of influence functions and a robust counterpart based on the Minimum Covariance Determinant (MCD) estimator is advocated. Then, focusing on two of the considered multivariate CV's, a diagnostic tool based on their influence functions is derived and its efficiency in detecting observations having an unduly large effect on variability is illustrated on a real-life data set. The influence functions are also used to compute asymptotic variances under elliptical distributions, yielding approximate confidence intervals. Finally, simulations are conducted in order to compare the performance of the classical and robust multivariate CV's in a finite sample setting. As expected, when the data are normally distributed, the classical estimator performs better than the robust counterpart based on the MCD estimator, while the reverse is true when the data are contaminated. [less ▲]

Detailed reference viewed: 16 (7 ULg)
Full Text
Peer Reviewed
See detailThe PLATO Simulator: modelling of high-precision high-cadence space-based imaging
Marcos-Arenal, P.; Zima, W.; De Ridder, J. et al

in Astronomy and Astrophysics (2014)

Many aspects of the design trade-off of a space-based instrument and its performance can best be tackled through simulations of the expected observations. The complex interplay of various noise sources in ... [more ▼]

Many aspects of the design trade-off of a space-based instrument and its performance can best be tackled through simulations of the expected observations. The complex interplay of various noise sources in the course of the observations make such simulations an indispensable part of the assessment and design study of any space-based mission. We present a formalism to model and simulate photometric time series of CCD images by including models of the CCD and its electronics, the telescope optics, the stellar field, the jitter movements of the spacecraft, and all important natural noise sources. This formalism has been implemented in a versatile end-to-end simulation software tool, called PLATO Simulator, specifically designed for the PLATO space mission to be operated from L2, but easily adaptable to similar types of missions. We provide a detailed description of several noise sources and discuss their properties, in connection with the optical design, the allowable level of jitter, the quantum efficiency of the detectors, etc. The expected overall noise budget of generated light curves is computed as a function of the stellar magnitude, for different sets of input parameters describing the instrument properties. The simulator is offered to the scientific community for future use. [less ▲]

Detailed reference viewed: 13 (5 ULg)
Full Text
Peer Reviewed
See detailElectromagnetic hypersensitivity and occupational exposure to electromagnetic fields (EMF)
Demaret, Isabelle ULg

Conference (2014, April 07)

Introduction Scientific publications on electromagnetic hypersensitivity began in the early 80' and were first related to video display terminals in the professional environment. Electromagnetic ... [more ▼]

Introduction Scientific publications on electromagnetic hypersensitivity began in the early 80' and were first related to video display terminals in the professional environment. Electromagnetic hypersensitivity is now more heterogeneous and complaints about electromagnetic fields (EMF) are often associated to mobile phone or wifi. Provocation studies did not find that persons claiming to have electromagnetic hypersensitivity were more able to detect EMF than others or that they displayed any special physiological changes when exposed to EMF. Since 1996, WHO defined this syndrome as Idiopathic Environmental Intolerance to ElectroMagnetic Fields (IEI-EMF), characterised by symptoms attributed to EMF. The diagnostic is made by the person itself. The symptoms are heterogeneous and are frequently encountered in the general population. Despite the lack of a proven causal relationship with EMF, these symptoms, and the anxiety related, can lead to important suffering. Some persons with IEI-EMF are even unable to work. IEI-EMF is classified among the functional somatic syndromes as other syndromes with no physiological basis (as multiple chemical sensitivity). Directive and IEI-EMF Studies showed that persons who feel more stressed in their professional environment and are less satisfied with their work are more prone to IEI-EMF. There are some elements in the directive that could frighten these persons: the directive does not consider long term effects; the limit values can be exceeded temporarily and a worker must be informed that he can have transient symptoms. Discussion Persons with IEI-EMF are afraid of adverse health effects and often think that these effects are not taken into account by official agency. For them, everything that can aggravate their fears will be difficult to handle. [less ▲]

Detailed reference viewed: 18 (2 ULg)
Full Text
See detailAccumulation lipidique par Yarrowia lipolytica: un nouvel outil d'observation
Bouchedja, Doria Naïla; Delvigne, Frank ULg; Boudjellal, Abdelghani et al

Conference (2014, April 06)

Detailed reference viewed: 22 (1 ULg)
Full Text
See detailEffet du traitement enzymatique sur la composition en polyphénols et sur le pouvoir antioxydant du sirop de dattes
Abbès, Fatma; Wissal, Kchaou; Blecker, Christophe ULg et al

Conference (2014, April 05)

Detailed reference viewed: 8 (1 ULg)