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See detailRecollection versus familiarity in normal aging and in mild cognitive impairment: Impact of test format.
Simon, Jessica ULg; Gilsoul, Jessica ULg; SALMON, Eric ULg et al

Poster (2016, July 18)

The aim of this study was to investigate the impact of test format on recollection and familiarity in normal aging and in MCI. Seventy young participants, 65 younger-old, 53 older-old, and 13 MCIs were ... [more ▼]

The aim of this study was to investigate the impact of test format on recollection and familiarity in normal aging and in MCI. Seventy young participants, 65 younger-old, 53 older-old, and 13 MCIs were presented with forced-choice and yes/no visual recognition memory tasks with the Remember/Know/Guess paradigm. The young people had better recognition performance than younger-old, who performed better than older-old and MCIs. Recollection and familiarity declined progressively in healthy aging. In MCI, recollection was more affected than familiarity, but patients demonstrated a more liberal use of familiarity. Finally, test format did not influence strongly the results. Young people used recollection more often in the forced-choice task compared to the yes/no task. [less ▲]

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See detailMetagenetics and predictive microbiology: a new tool to understand the kinetics of microbial subpopulation in minced pork meat
Cauchie, Emilie ULg; Delhalle, Laurent; Taminiau, Bernard et al

Poster (2016, July 18)

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See detailMetagenetics and predictive microbiology: a new tool to understand the kinetics of microbial subpopulations in Belgian white pudding
Cauchie, Emilie ULg; Gand, Mathieu; Kergourlay, Gilles et al

Poster (2016, July 18)

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See detailStatistical physics of memory driven systems
Hubert, Maxime ULg

Poster (2016, July 18)

For classical systems, statistical description is usually required when the dimension of the system phase space is important. This description is used when considering many body problems such as the ... [more ▼]

For classical systems, statistical description is usually required when the dimension of the system phase space is important. This description is used when considering many body problems such as the thermodynamical description of fluids, granular media or the diffusion of Brownian particles in the presence of a thermal reservoir. Can this limit be reached at the single particle level? We address this question by considering a single particle coupled to its own past, via a wave-mediated size-controllable memory, which stores the past trajectory of the particle. Such an object has been turn into reality by Couder et al [1,2] by using liquid bouncing droplets that interact with the waves they generate by impacting a liquid surface. In those experiments, the memory is made by stationary waves with a tunable damping time. The wave memory triggers various regime from individual self-propelled particle motion to structured chaos [3] or self-organization processes between a particle and its waves [4]. In the limit of a large amount of “souvenirs” stored in the wave field, we will show that the dynamics can be well described by the tools of non-equilibrium statistical mechanics. Both the dynamics of the particle and the wave-mediated memory are investigated. We show that, from the particle-point of view, the memory acts as a random force. The particle dynamics is adequately described by a Langevin equation for self-propelled systems. The corresponding Fokker-Planck equation shows that the memory can be seen as a thermal reservoir whose temperature is tuned via the amount of “souvenirs” in the dynamics. The features of this unusual wave-like thermal reservoir are investigated from an energetic and entropic perspective. We show that the global wave field is on average weaker that one would expect from superposition of random wave fields. This depletion originates from destructive interferences that the particle generates along its trajectory, corresponding to a kind-of minimization principle. [1] Y. Couder, S. Protière, E. Fort & A. Boudaoud, “Walking and orbiting droplets”, Nature, 437, 208 (2005). [2] A. Eddi, E. Sultan, J. Moukhtar, E. Fort, M. Rossi & Y. Couder, “Information stored in Faraday waves: the origin of a path memory”, J. Fluid Mech., 674, 433- 463 (2011). [3] S. Perrard, M. Labousse, E. Fort & Y. Couder, “Chaos driven by interfering memory”, Phys. Rev. Lett, 113, 104101 (2014). [4] S. Perrard, M. Labousse, M. Miskin, E. Fort & Y. Couder, “Self-organization into quantized eigenstates of a classical wave-driven particle”, Nat. Comm., 5, 3219 (2014). [less ▲]

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See detailProbing single molecules with the AFM: Force, motion, dynamics, and function
Duwez, Anne-Sophie ULg

Conference (2016, July 18)

Detailed reference viewed: 11 (2 ULg)
Peer Reviewed
See detailOn the organization of episodic future thoughts in event clusters
D'Argembeau, Arnaud ULg

Conference (2016, July 18)

Memory can be flexibly used to image events that might happen in one’s personal future, a capacity that has been referred to as episodic future thinking. In this talk, I will present data showing that ... [more ▼]

Memory can be flexibly used to image events that might happen in one’s personal future, a capacity that has been referred to as episodic future thinking. In this talk, I will present data showing that many episodic future thoughts are not represented in isolation, but instead are part of higher-order event clusters that organize imagined events in coherent themes and causal sequences. Personal goals seem to play an important role in this organization and neuroimaging evidence shows that event clusters recruit brain regions supporting conceptual and integrative processing. These findings suggest that episodic future thinking involves the integration of specific event representations with autobiographical knowledge, which contextualizes imagined events with respect to personal goals and general expectations about one’s life. [less ▲]

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See detailUltrafast Spin Dynamics in FeRh
Ostler, Thomas ULg

Conference (2016, July 16)

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See detailLe français pour l’unité et l’intégration nationales au cameroun
Mouto Betoko, Christiane ULg

Conference (2016, July 16)

La politique du bilinguisme officiel s’est imposée au Cameroun pour des raisons d’unité nationale suite à une double colonisation franco-britannique. En milieu scolaire, le bilinguisme renvoie ... [more ▼]

La politique du bilinguisme officiel s’est imposée au Cameroun pour des raisons d’unité nationale suite à une double colonisation franco-britannique. En milieu scolaire, le bilinguisme renvoie généralement à l’enseignement du français en tant que deuxième langue officielle aux Anglophones et, à l’enseignement de l’anglais en tant que deuxième langue officielle aux Francophones. Néanmoins, les élèves anglophones éprouvent d’énormes difficultés d’intégration à la fin des études secondaires. Quels sont donc les objectifs de l’enseignement du français aux élèves anglophones ? Quelle est l’approche méthodologique mise en œuvre pour atteindre ces objectifs ? Et enfin, comment allier objectifs scolaires du bilinguisme et méthodologie du FLE pour préparer les élèves anglophones à la vie après le secondaire ? [less ▲]

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See detailOn the use of ROC curves in DIF simulation studies
Magis, David ULg; Tuerlinckx, Francis

Conference (2016, July 14)

Simulation studies are often used to compare methods to detect differential item functioning (DIF). However, comparing the performance of such methods can become complicated when the identification of DIF ... [more ▼]

Simulation studies are often used to compare methods to detect differential item functioning (DIF). However, comparing the performance of such methods can become complicated when the identification of DIF items relies on statistics based on pre-defined significance level or on pre-established cutoff values. DIF methods based on conceptually different approaches may therefore become incomparable in terms of summary DIF statistics such as false alarm rate or hit rate. The purpose of this talk is to overcome this analytic issue by introducing receiver operating characteristic (ROC) curves in this context. ROC curves allow for global comparison of methods’ performances by computing pairs of (false alarm, hit) rates and representing them on a common scatter plot. Several summary ROC statistics can be considered for further analysis. The application of the ROC curve methodology, together with its limitation and possible extensions, is illustrated by a simple simulation study that compares three score-based DIF methods (Mantel-Haenszel, standardization and Delta plot). [less ▲]

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See detailExamine the effects of two adjustments to the lz statistic
Riley, Barth; Magis, David ULg

Conference (2016, July 14)

Conformity to a known distribution and sensitivity to response aberrance are desirable properties of person-fit statistics. This simulation study examined the joint and independent effects of two ... [more ▼]

Conformity to a known distribution and sensitivity to response aberrance are desirable properties of person-fit statistics. This simulation study examined the joint and independent effects of two adjustments to the standardized log-likelihood statistic (lz): (1) correction of the negatively skewed distribution of lz (Snijders, 2001), and (2) improving the sensitivity of the statistic by employing more accurate estimates of item response probability using symmetric functions (Dimitrov and Smith, 2006). Data were simulated using three test lengths (10, 20, 30 items). Data containing misfitting response patterns were simulated using three aberrant response patterns (cheating, guessing, and inattentiveness), and three levels of aberrance (i.e., proportion of item responses affected by misfit; 10%, 30% and 50%). Data containing no simulated misfitting response patterns were also generated for each test length. Non-misfitting responses were generated using the dichotomous Rasch measurement model. For each combination of independent variables, a dataset was generated consisting of 5,000 simulees. Four fit statistics were compared: lz, lz* (Snijders adjustment), lzSYM (Dimitrov and Smith adjustment), and lzSYM* (both adjustments). Mean Type I error rates were ≤ 0.1 across all conditions. The lz* statistic produced the best control of Type I error, which was often below the nominal Type I error rate, whereas the empirical Type I error rate for the unadjusted lz statistic most closely approximated the nominal rate. In contrast, lzSYM and lzSYM* yielded empirical Type I error rates larger than the nominal rate, with the discrepancy being particularly pronounced as the length of the test decreased. As might be expected, power to detect misfitting response patterns increased with test length and with the percentage of misfitting response patterns in the sample. Both lzSYM and lzSYM* evidenced improved power in detecting misfitting response patterns compared to lz and lz*, particularly for guessing response patterns and/or on shorter (i.e., 10 item) tests. [less ▲]

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See detailRoland Barthes et les écritures de la chronique
Stienon, Valérie ULg

Conference (2016, July 14)

La plupart des textes de Roland Barthes sont le produit d’une commande – qu’elle soit amicale, événementielle, éditoriale. L’inscription dans un genre ou l’investissement d’un mode d’écriture s’appuie ... [more ▼]

La plupart des textes de Roland Barthes sont le produit d’une commande – qu’elle soit amicale, événementielle, éditoriale. L’inscription dans un genre ou l’investissement d’un mode d’écriture s’appuie donc sur une situation de communication dont les paramètres sont souvent bien déterminés et qui est elle-même guidée par une demande préalable, de sorte que dispositif générique et horizon d’attente s’entre-déterminent de manière cruciale. Plus encore, les commandes passées à Barthes, avant d’être des livres, prennent généralement la forme d’articles dans des périodiques. Il y a de la sorte une dimension intrinsèquement circonstancielle à l’écriture barthésienne, dimension propice à la relation d’actualité. Dès lors, dans quelle mesure la chronique peut-elle offrir une clé de lecture du cheminement d’écriture de Barthes et du parcours de sa pensée ? [less ▲]

Detailed reference viewed: 15 (0 ULg)
See detailCharacterization of FRD3, a zinc and iron homeostasis actor in Arabidopsis relatives
Scheepers, Maxime ULg; Charlier, Jean Benoit; Spielmann, Julien ULg et al

Conference (2016, July 14)

Zinc and iron are two essential micronutrients for plants. The homeostasis networks of the two metals are intertwined. Arabidopsis halleri is a zinc- and cadmium-tolerant and zinc-hyperaccumulating ... [more ▼]

Zinc and iron are two essential micronutrients for plants. The homeostasis networks of the two metals are intertwined. Arabidopsis halleri is a zinc- and cadmium-tolerant and zinc-hyperaccumulating species, which also present adaptation of its iron homeostasis(1,4). Transcriptomic studies identified genes which are constitu-tively over-expressed in Arabidopsis halleri compared to Arabidopsis thaliana and which may have a role in metal tolerance or accumulation(2-4). Among them, a candidate gene encodes the FRD3 (FERRIC REDUCTASE DEFECTIVE 3) protein, a member of the MATE family of membrane transporters. FRD3 is a citrate transporter involved in iron homeostasis(5-7) and plays a role in zinc tolerance in A. thaliana(8). The FRD3 gene displays a complex regulation. In A. thaliana, alternative transcript initiation for FRD3 determines two transcripts, which dif-fer in their 5'UTRs and have differential translation efficiency. The two transcripts are selectively regulated under stress conditions: iron and zinc depletion, zinc excess or cadmium presence(9). In A. halleri, a single highly ex-pressed FRD3 transcript with high translation efficiency is present(9). We are further examining the FRD3 function in zinc and iron homeostasis in A. thaliana and A. halleri. We will present data (i) on the high expression of FRD3 in A. halleri, (ii) on the functional characterization of the two alternative FRD3 transcripts and their role in metal homeostasis in A. thaliana in comparison with the A. halleri FRD3 transcript and (iii) on the zinc phenotypes of the frd3 A. thaliana mutant. [less ▲]

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See detailOpen source programming: a new hope for psychometric research
Magis, David ULg

Conference (2016, July 14)

Current psychometric research is most often supported by computer software. New research perspectives often imply intensive simulation studies to validate the tested theories or hypotheses, and therefore ... [more ▼]

Current psychometric research is most often supported by computer software. New research perspectives often imply intensive simulation studies to validate the tested theories or hypotheses, and therefore require accurate, fast and stable implementation. To this regards, open source programming (such as in the R language) is a promising approach allowing for flexible implementation, data generation, replication of studies, and worldwide dissemination. The purpose of this talk is to illustrate how psychometrics and open source programming (with special emphasis on the R language) can interact and contribute to each other, by means of some selected examples. Several topics will be illustrated, among others: why open source programming is (to my opinion) as important as psychometric research; why we need for stable and complete implementation of psychometric and statistical routines for research purposes (for e.g., CAT); how accurate implementation of IRT routines can lead to unexpected theoretical results; why (and how) open source software can be valued as research output. Most examples will arise from the CAT framework and the R package catR for simulating CAT patterns. [less ▲]

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See detailMomentum- and Heat-Flux Parameterization at Dome C, Antarctica: A Sensitivity Study
Vignon, Etienne; Genthon, Christophe; Barral, Hélène et al

in Boundary-Layer Meteorology (2016)

Detailed reference viewed: 12 (1 ULg)
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See detailSanté et sécurité au travail: un modèle intégratif pour prédire les comportements de sécurité.
Laurent, Julie ULg; Chmiel, Nik; Hansez, Isabelle ULg

Conference (2016, July 13)

INTRODUCTION. La santé et la sécurité sont deux thématiques qui ont souvent été traitées séparément dans la littérature scientifique. Hansez et Chmiel (2010) ont démontré la pertinence d’utiliser le ... [more ▼]

INTRODUCTION. La santé et la sécurité sont deux thématiques qui ont souvent été traitées séparément dans la littérature scientifique. Hansez et Chmiel (2010) ont démontré la pertinence d’utiliser le modèle ‘demandes-ressources’ (Bakker et Demerouti, 2007) afin d’expliquer les comportements de sécurité au travail. La présente étude propose d’étendre ce modèle en y incluant un processus d’échange social, spécifiquement lié à la sécurité, en plus des processus motivationnel, cognitif-énergétique et instrumental. METHODES. Notre échantillon est composé de 1922 travailleurs d’une entreprise métallurgique belge. Notre modèle théorique a été testé à l’aide de la modélisation par équations structurales, avec le logiciel MPlus. RESULTATS. Le modèle final présente des indices d’adéquation acceptables (²=3346.63, dl=678, RMSEA=.04, CFI=.92, NNFI=.91). Les résultats montrent que les quatre processus psychologiques sont impliqués. Les violations « situationnelles » (i.e. le fait de commettre des infractions qui sont dues à des lacunes de l’organisation et sans lesquelles le travail ne pourrait pas être réalisé) sont expliquées par (1) un processus motivationnel, puisque les ressources encouragent les travailleurs à être stimulés par leur travail, et ainsi à moins commettre ce type d’infractions (2) un processus instrumental, puisque percevoir l’implication de son management dans la sécurité est associé directement à moins de violations situationnelles, et par (3) un processus social, puisque les ressources de travail permettent aux employés de percevoir l’implication de leur management dans la sécurité, et de répondre à cet intérêt en considérant la sécurité comme faisant partie de leur rôle, ce qui les encourage ensuite à participer à des activités volontaires liées à la sécurité. D’autre part, les violations de « routine » (i.e. le fait de « prendre des raccourcis » et de ce fait ne pas respecter les procédures de sécurité) sont expliquées par les mêmes processus d’échange social et motivationnel, mais aussi par un processus cognitif-énergétique, puisque des conditions de travail contraignantes peuvent mener à plus de stress, associé à son tour à plus de violations de routine. DISCUSSION. La principale limitation de cette étude est la nature auto-rapportée des données, pouvant mener à différents biais. Néanmoins, différentes implications pratiques peuvent être mises en évidence. Les entreprises désireuses de réduire les violations des règles de sécurité devraient considérer à la fois les processus spécifiquement liés à la sécurité et des processus psychologiques plus larges. Par exemple, outre l’importance d’améliorer les conditions de travail considérées comme des ressources, il est important de garder à l’esprit que ces ressources déterminent des processus complexes d’échanges sociaux spécifiquement liés à la sécurité, à travers l’influence primordiale du management. [less ▲]

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See detailA Crypt of Swipes. Charles Burns Haunted by Tintin
Crucifix, Benoît ULg

Conference (2016, July 13)

Detailed reference viewed: 24 (7 ULg)